Compositions and methods for restoring cognitive and behavioral function

Abstract

A method of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder includes administering to the subject an amount of an aminopropyl carbazole compound effective to normalize NAD+ / NADH redox levels in the subject's brain without abnormally elevating NAD+ levels and restore cognitive and / or behavioral function in the subject.

Description

PATENT COMPOSITIONS AND METHODS FOR RESTORING COGNITIVE AND BEHAVIORAL FUNCTION RELATED APPLICATION

[0001] This application claims priority from U.S. Provisional Application No.63 / 634,634, filed April 16, 2024, the subject matter of which is incorporated herein by reference in its entirety. BACKGROUND

[0002] Alzheimer’s disease (AD), the most common neurodegenerative disorder and leading cause of dementia, has historically been considered irreversible. Current projections estimate that over 150 million individuals worldwide could be suffering from this condition by 2050, incurring annual costs exceeding two trillion dollars, underscoring the urgent need for effective therapies. Despite decades of research, existing treatments, primarily targeting amyloid beta (Aβ) pathology or symptom management, have shown limited clinical efficacy in halting cognitive decline or improving quality of life for patients and caregivers. For example, recent advances in anti-amyloid antibody therapies, while demonstrating partial amyloid clearance, have raised concerns about safety risks and inconsistent therapeutic benefits. This highlights the necessity to explore complementary or alternative therapeutic strategies for AD. Notably, emerging clinical observations challenge the assumption that Aβ pathology alone drives AD. For example, cognitive decline in aging primates, including humans, does not consistently correlate with amyloid plaque burden. Furthermore, individuals classified as nondemented with Alzheimer’s neuropathology (NDAN) exhibit significant amyloid plaque accumulation without cognitive impairment. It is also important to recognize that carriers of autosomal dominant AD mutations remain asymptomatic for many decades prior to clinical onset. Taken together, these findings suggest intrinsic mechanisms of brain resilience that may delay or counteract disease progression, offering the potential for therapeutics that modify the trajectory of AD, potentially even fostering brain recovery in advanced disease. SUMMARY

[0003] Embodiments described herein relate to compositions and methods of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioraldeficit associated with a neurodegenerative We found that diminution of brain NAD+homeostasis (or NAD+ / NADH redox state) in neurodegenerative disorders, such as Alzheimer’s disease (AD) and / or other tauopathies, can drive the loss of brain resilience that gives way to secondary pathologic events. We further found that these events, as well as neuropsychiatric and cognitive impairment, are prevented and reversed when brain NAD+homeostasis is normalized. Notably, we show that pharmacologically preserving NAD+homeostasis (or NAD+ / NADH redox state), without abnormally elevating, brain NAD+level in presymptomatic amyloid pathology-driven mice prevents plaque accumulation, tau phosphorylation, blood-brain barrier deterioration, oxidative stress, DNA damage, neuroinflammation, impaired hippocampal neurogenesis, deficient synaptic plasticity, neurodegeneration, and neuropsychiatric and cognitive impairment. Furthermore, delaying treatment until mice are fully symptomatic reverses most features and restores normal behavior and cognition in both amyloid pathology-driven and tau pathology-driven models, without mitigating genetically driven amyloid or tau pathology. Normalizing NAD+homeostasis (or NAD+ / NADH redox state) also prevents oxidative damage and mitochondrial dysfunction in oxidatively stressed human brain microvascular endothelial cells. Our results offer the first proof of principle for reversing brain pathology and restoring cognition in neurodegenerative disorders, such as AD.

[0004] In some embodiments, a method of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder can include administering to the subject an amount of an aminopropyl carbazole compound (e.g., P7C3 or derivatives thereof) effective to normalize NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level and restore cognitive and / or behavioral function in the subject.

[0005] In some embodiments, the neurodegenerative disorder is selected from subarachnoid hemorrhage, schizophrenia, major depression, bipolar disorder, epilepsy, traumatic brain injury and / or a visual symptom associated therewith, post-traumatic stress disorder, Parkinson’s disease, Parkinson Plus syndromes, Lewy Body Dementia, multiple system atrophy, corticobasal neurodegeneration, progressive supranuclear palsy, AD, AD related dementias, Down syndrome, spinocerebellar ataxia, amyotrophic lateral sclerosis, Huntington’s disease, stroke, brain radiation therapy, chronic stress, abuse of a neuro-active drug, retinal degeneration, spinal cord injury, peripheral nerve injury, idiopathic peripheralneuropathy, cognitive decline and / or associated with normal aging and / or chemotherapy, chemotherapy induced neuropathy, concussive injury, peripheral nerve crush injury, peripheral neuropathy, diabetic neuropathy, post-traumatic headache, multiple sclerosis, retinal degeneration and dystrophy, Leber congenital amaurosis, retinitis pigmentosa, cone-rod dystrophy, microphthalmia, anophthalmia, myopia, and hyperopia, spinal cord injury, traumatic spinal cord injury, peripheral nerve injury, retinal neuronal death related diseases, retinal trauma, Autism, Stargardt disease, Kearns-Sayre syndrome, Pure neurosensory deafness, Hereditary hearing loss with retinal diseases, Hereditary hearing loss with system atrophies of the nervous system, Progressive spinal muscular atrophy, Progressive bulbar palsy, Primary lateral sclerosis, Hereditary forms of progressive muscular atrophy and spastic paraplegia, Frontotemporal dementia, Dementia with Lewy bodies, Corticobasal degeneration, Progressive supranuclear palsy, Prion disorders causing neurodegeneration, Multiple system atrophy, Hereditary spastic paraparesis, Friedreich ataxia, Non-Friedreich ataxia, Spinocerebellar atrophies, Amyloidoses, Metabolic-related neurodegenerative disorders, Toxin-related neurodegenerative disorders, Multiple sclerosis, Charcot Marie Tooth, Diabetic neuropathy, Metabolic neuropathies, Endocrine neuropathies, Creutzfeldt-Jacob Disease, Primary progressive aphasia, tauopathy, Frontotemporal Lobar Degeneration, Cortical blindness, Shy-Drager Syndrome, Diffuse cerebral cortical atrophy of non-Alzheimer type, Lewy-body dementia, Pick disease, Thalamic degeneration, Mesolimbocortical dementia of non-Alzheimer type, Nonhuntingtonian types of chorea and dementia, Cortical-striatal-spinal degeneration, Dementia-Parkinson-amyotrophic lateral sclerosis complex, Cerebrocerebellar degeneration, Cortico-basal ganglionic degeneration, Familial dementia with spastic paraparesis or myoclonus, Tourette syndrome, or viral infection.

[0006] In other embodiments, the neurodegenerative disorder is a tauopathy.

[0007] In some embodiments, the subject has been identified as having at least one of AD, Lewy body dementia, Vascular dementia, Age-related dementia, Frontotemporal dementia, or mixed dementia.

[0008] In some embodiments, the neurodegenerative disorder is AD.

[0009] In other embodiments, the neurodegenerative disorder is not AD.

[0010] Other embodiments described herein relate to a method of treating a subject with a tauopathy or a dementia-related disease. The method includes administering to thesubject an amount of an aminopropyl compound (e.g., P7C3 or derivatives thereof) effective to normalize NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level and restore cognitive and / or behavioral function in the subject.

[0011] In some embodiments, the tauopathy is selected from AD, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), Parkinson's discase, Pick's disease (PiD), primary progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler-Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle- predominant dementia, ganglioglioma, gangliocytoma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT).

[0012] Other embodiments described herein relate to a method of inhibiting and / or reducing β-amyloid plaque accumulation and / or Tau phosphorylation in a subject in need thereof. The method includes administering to the subject an amount of an aminopropyl carbazole compound (e.g., P7C3 or derivatives thereof) effective to normalize NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level and reduce β-amyloid plaque accumulation and / or Tau phosphorylation in the subject.

[0013] In some embodiments, the has or is at increased risk of a tauopathy, such as AD, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), Parkinson's discase, Pick's disease (PiD), primary progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler- Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle- predominant dementia, ganglioglioma, gangliocytoma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT).

[0014] In other embodiments, the tauopathy is not Alzheimer’s disease.

[0015] In some embodiments, the aminopropyl carbazole compound includes a compound having formula (I): or pharmaceutically acceptable salt thereofeach of R1, R2, R4, R5, R7, is independently selected from hydrogen, halo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, -NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and nitro; each of R3and R6is independently selected from fluoro, bromo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6 haloalkyl, C1-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, -NH(C1-C6 alkyl), - N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and nitro; each of L1and L2is, independently, C1-C3 alkylene, which is optionally substituted with from 1-2 independently selected Rc; A is: (i) CRA1RA2, wherein one of RA1and RA2is halo or OR9, wherein R9is hydrogen or C1-C3 alkyl that is optionally substituted with hydroxyl or C1-C3 alkoxy; and the other of RA1and RA2is hydrogen, halo, or C1-C3 alkyl; or (ii) C=O; Z is: -NR10R11; or -OR12; or -S(O)nR13, wherein n is 1, or 2; each of R10and R11is independently selected from: (a) hydrogen; (b) C6-C10aryl that is optionally substituted with from 1-4 Rb; (c) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; (d) C1-C6 alkyl or C1-C6 haloalkyl, each of which is optionally substituted with from 1-3 Rd; (e) -C(O)(C1-C6 alkyl), -C(O)(C1-C6 haloalkyl), or -C(O)O(C1-C6 alkyl); or (f) C2-C6 alkenyl or C2-C6 alkynyl; wherein one of R10and R11is selected from (b) or (c) and the other of R10and R11is selected from (a), (d), (e), or (f); R12is: (i) C6-C10 aryl that is optionally substituted with from 1-4 Rb; or (ii) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; R13is: C6-C10aryl that is optionally substituted with from 1-4 Rb;Rbat each occurrence is selected from the substituents delineated in (aa) through (dd) below: (aa) C1-C6 haloalkoxy; C1-C6 thioalkoxy; C1-C6 thiohaloalkoxy; -O-(CH2)1-3- [O(CH2)1-3]1-3-H; -NH(C1-C6alkyl), -N(C1-C6alkyl)2, wherein the alkyl portion of each is unsubstituted or substituted with from 1-3 independently selected Re; (bb) hydroxyl; cyano; -NH2; azido; sulfhydryl; C2-C6alkenyl; C2-C6alkynyl; -C(O)H; -C(O)( C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)O(C1-C6 alkyl); -C(O)NH2; - C(O)NH(C1-C6alkyl);-C(O)N(C1-C6alkyl)2; -SO2(C1-C6alkyl); -SO2NH2; -SO2NH(C1-C6alkyl); -SO2N(C1-C6 alkyl)2; (cc) C3-C6 cycloalkyl or heterocyclyl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heterocyclyl is independently selected from N, NH, N(C1- C6 alkyl), NC(O)(C1-C6 alkyl), 0, and S; and (dd) phenyl or heteroaryl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heteroaryl is independently selected from N, NH, N(C1-C3 alkyl), O, and S; wherein each of said phenyl and heteroaryl is optionally substituted with from 1-3 substituents independently selected from halo; hydroxyl; cyano; nitro; -NH2; -NH(C1-C6 alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), C1-C6alkoxy; C1-C6haloalkoxy; C1-C6thioalkoxy; C1-C6 thiohaloalkoxy; C1-C6 alkyl, and C1-C6 haloalkyl; Rcat each occurrence is, independently selected from halo, C1-C6alkoxy, C1- C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, -NH2, - NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and cyano; Rdat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, -NH2, NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and cyano; and Reat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy; C1-C6thioalkoxy; C1-C6haloalkoxy; C1-C6thiohaloalkoxy; -NH2; -NH(C1-C6alkyl); -N(C1- C6 alkyl)2; -NHC(O)( C1-C6 alkyl); cyano; -C(O)H; -C(O)(C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)OH; -C(O)O(C1-C6alkyl); -C(O)NH2; -C(O)NH(C1-C6alkyl); -C(O)N(C1- C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6 alkyl)2; and L3- (C1-C6alkylene)-biotin, wherein L3is a -O-, -NH-, -NCH3-, -C(O)-, -C(O)NH-, -C(O)NCH3-, -NHC(O)-, or -NCH3C(O)-.

[0016] In some embodiments, the prior to administration of the aminopropyl carbazole compound has a decline or diminution in brain NAD+homeostasis (or NAD+ / NADH redox state) associated with a decreased NAD+level and an increased NADH level.

[0017] In some embodiments, the decline in brain NAD+ / NADH ration or redox state is at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, or at least about 75% compared to control normal or healthy subject.

[0018] In some embodiments, the aminopropyl carbazole compound is 3,6-dibromo-3- fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine (P7C3-A20) or a pharmaceutically acceptable salt thereof.

[0019] In some embodiments, the aminopropyl carbazole compound is administered chronically to the subject at an amount effective to maintain normalization of NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

[0020] In some embodiments, the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 300 mg / kg body weight per day.

[0021] In some embodiments, the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 1000 mg per day.

[0022] In some embodiments, the method further includes measuring NAD+ / NADH redox state (or NAD+and NADH levels) in the subject’s brain prior to administration of the aminopropyl carbazole compound and administering the aminopropyl carbazole compound if the subject has a decline in brain NAD+ / NADH redox state or NAD+homeostasis compared to a control.

[0023] Still other embodiments relate to the use of an aminopropyl carbazole compound, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level (e.g., P7C3 or derivatives thereof), in the preparation of a medicament for use in any of the methods described herein.BRIEF OF THE DRAWINGS

[0024] Figs.1(A-J) illustrate P7C3-A20 treatment of aged symptomatic 5xFAD mice restores brain NAD+homeostasis, cognitive function, and hippocampal synaptic plasticity. (A) Reduced brain NAD+ / NADH in 12-month-old 5xFAD mice is restored to normal by administration of daily P7C3-A20 from 6 to 12 months of age. This same exposure of P7C3- A20 to WT littermates does not affect their brain NAD+homeostasis. (n=4-6 female mice and 5-8 male mice per group). (B) Schematic of Alzheimer’s disease reversal study with P7C3- A20 in 5xFAD mice. (C) Memory in the novel object recognition (NOR) task, as measured by discrimination index, is impaired in 12-month-old advanced-disease 5xFAD mice, relative to WT littermates. This memory deficit is reversed by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=16-20 female mice and 15-20 male per group). (D) In the Morris water maze (MWM) task, both learning (measured by latency time to find the platform) and memory (measured by the number of platform crossings in the probe test) are impaired in 12-month-old advanced-disease 5xFAD mice, relative to WT littermates. (E) Learning and memory deficits are both reversed in 5xFAD mice by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=20 female mice and 20 male mice per group). Learning in the accelerating rotarod test is impaired in 12-month-old advanced disease 5xFAD mice, relative to WT controls. This impairment is reversed by P7C3-A20. Motor performance in the probe phase of this task is also impaired in 12-month- old advanced-disease 5xFAD mice, as evidenced by more quickly falling off the accelerating rotarod (time until falling) and falling off the accelerating rotarod at a slower speed (speed at falling), relative to WT littermates. These deficits are reversed by treatment with P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=20 female mice and 20 male mice per group). (F) Twelve-month-old advanced-disease 5xFAD mice display abnormal anxiolytic-like activity in the elevated plus maze, as evidenced by spending more time in the open arms and less time in the closed arms relative to WT littermates. This deficit is reversed by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=20 female mice and 20 male mice per group). (G) Twelve-month-old advanced-disease 5xFAD mice display manic-like behavior, as evidenced by reduced immobility time in the forced swim test (FST), relative to WT littermates. This aberrant behavior is prevented by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (*p < 0.05, ****p< 0.0001; one-way ANOVA and Dunnett comparisons, n=10-11 female mice and 6- 12 male mice per group). (H) Twelve-month-old advanced-disease 5xFAD mice show abnormal hindlimb clasping, relative to WT littermates, which is prevented by P7C3-A20. Representative pictures are shown for both males and females of each group, and the clasping score is displayed below the pictures. WT littermate mice are not affected in this task by P7C3-A20. (n=8-9 female mice and 9-10 male mice per group). (I) Hippocampal long-term potentiation (LTP) after theta-burst stimulation is impaired in 12-month-old advanced-disease 5xFAD mice, compared to WT littermates. This deficit is reversed by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n= 27 slices from 5 WT VEH female mice; n=40 slices from 75xFAD VEH female mice; n=38 slices from 5 WT P7C3- A20 female mice; n=35 slices from 55xFAD P7C3-A20 female mice). (J) Mean potentiation during the last 10 min of recording is impaired in 12-month-old advanced-disease 5xFAD mice, compared to WT littermates. This is prevented by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n= 27 slices from 5 WT VEH female mice; n=40 slices from 75xFAD VEH female mice; n=38 slices from 5 WT P7C3-A20 female mice; n=35 slices from 55xFAD P7C3-A20 female mice). There are no sex-specific differences in any group. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p < 0.05,**p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group, with two-way ANOVA for learning phase in (D) and for (I). See also Fig.7.

[0025] Figs.2(A-J) illustrate P7C3-A20 treatment of aged symptomatic 5xFAD mice reverses amyloid plaque accumulation and BBB deterioration. (A) Accumulation of pathological amyloid structure plaques in 12-month-old 5xFAD mice is reduced by P7C3- A20 in the cerebral cortex and hippocampus, as shown by ThioS-positive % area. WT littermate mice are not affected by P7C3-A20. (representative images of ThioS-staining in cerebral cortex; n=4 females per group; scale bar = 200 µm). (B) Aβ aggregation in 12- month-old 5xFAD mice is not affected by P7C3-A20, as evidenced by quantification of 6E10-postive % area, which was stained in the same sections as used for this staining in (A). WT littermate mice are not affected by P7C3-A20. (representative images of 6E10 staining in cerebral cortex; n=4 females per group; scale bar = 200 µm). (C) Western blot shows APP and p-tau (Ser202 / Thr205) in cerebral cortex of 12-month-old mice (GAPDH protein used asloading control). While p-tau in 5xFAD reduced by P7C3-A20, increased brain APP is not affected. WT littermate mice are not affected by P7C3-A20. (n=4 males and 4 females per group). (D) Soluble brain Aβ1-40 and Aβ1-42 levels are elevated in 12-month-old 5xFAD mice and not affected by P7C3-A20. (E) WT littermate mice are not affected by P7C3-A20. (n=4 males and 4 females per group). Insoluble brain Aβ1-40 and Aβ1-42 levels are elevated in 12-month-old 5xFAD mice and not affected by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=4 males and 4 females per group). (F) Pathologically elevated brain p-tau (Ser202, Thr205) in 12-month-old 5xFAD mice is prevented by P7C3-A20. Western blot Fig.1C. WT littermate mice are not affected by P7C3-A20. (n=4 females and 4 males per group). (G) Increased open space around blood vessels due to astrocytic end feet disruption (as shown by red arrows on representative transmission electron microscopy (TEM) images) in the cerebral cortex BBB of 12-month-old 5xFAD mice is reversed by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 1µm). (H) Increased infiltration of IgG into the brain parenchyma of cerebral cortex and hippocampus in 12-month-old 5xFAD mice, relative to WT littermates, is reversed by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=4 females and 4 males per group, scale bar = 20µm). (I) Reduced pericyte coverage (CD 13, red) of blood vessel endothelial cells (CD 31, green) in the cortex and hippocampus of 12-month-old 5xFAD mice is reversed by P7C3-A20 treatment. WT littermate mice are not affected by P7C3-A20. (n= 3-4 females and 3-4 males per group, scale bars = 20µm). (J) Reduced ZO-1 expression in 12-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=5 females and 5 males per group). There are no sex-specific differences in any group. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p < 0.05,**p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group. See also Fig.8.

[0026] Figs.3(A-F) illustrate P7C3-A20 treatment of aged symptomatic 5xFAD mice reverses DNA damage, reverses neuroinflammation, and prevents young and mature neuronal cell death. (A) DNA damage in the hippocampus, as measured by TUNEL staining (green signal), is elevated in 12-month-old 5xFAD mice and reversed to normal levels by P7C3- A20. WT littermate mice are not affected by P7C3-A20. (representative CA1 regions shown, n=3-5 females per group, scale bar = 200µm). (B) GFAP (green signal) in the cerebral cortexand hippocampus is elevated in 12-month- mice and partially reversed by P7C3- A20. WT littermate mice are not affected by P7C3-A20. (n=3-4 females and 3-4 males per group, scale bar = 50µm). (C) IBA1 (red signal) in the cerebral cortex and hippocampus is elevated in 12-month-old 5xFAD mice and partially reversed by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3-4 females and 4 males per group, scale bar = 50µm). (D) IL-2 and IL-13 cytokine levels in the hippocampus are reduced in 12-month-old 5xFAD mice and reversed towards normal by P7C3-A20. WT littermate mice are not affected by P7C3-A20. TNF-α and IFN-γ cytokine levels in the hippocampus are not altered in 12-month-old mice as a function of genotype or treatment. (n=4-5 females per group). (E) Mature neuronal survival, as evidenced by NeuN staining in cerebral cortex and hippocampus, is reduced in 12-month-old 5xFAD mice. This neuronal loss is prevented by P7C3-A20 treatment. WT littermate mice are not affected by P7C3-A20. (n=3-4 females and 3-4 males per group, scale bar = 50µm). (F) Survival of young hippocampal neurons labeled with BrdU is reduced in 12-month-old 5xFAD mice and reversed to normal levels by P7C3- A20. Young hippocampal neuron survival is also increased in 12-month-old WT littermates, as expected. (n=4-6 females and 4-6 males per group, scale bar = 50µm). There are no sex- specific differences in any group. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p<0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group. See also Fig.9.

[0027] Figs.4(A-J) illustrate oxidative stress is reversed by P7C3-A20 in aged symptomatic 5xFAD mice and oxidatively-stressed human brain microvascular endothelial cells. (A) Elevated lipid peroxidation (4-HNE) in the cerebral cortex and hippocampus of 12- month-old 5xFAD mice is reversed by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 50µm). (B) Elevated protein nitration (3-N- Tyr) in the cerebral cortex and hippocampus of 12-month-old 5xFAD mice is reversed by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 50µm). (C) Disrupted NAD+homeostasis in human brain microvascular endothelial cells (HBMVECs) following exposure to hydrogen peroxide (H2O2) is prevented by P7C3-A20. The protective efficacy of P7C3-A20 is blocked by co-treatment with FK866, a selective inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in NAD+synthesis. (n=3-4 cell culture wells per group). (D) NAD+homeostasis isnot altered in naïve HBMVECs by P7C3- (n=3 cell culture wells per group). (E) Increased CellROX Green signal, a measure of cellular oxidative stress, in HBMVECs following H2O2 exposure is prevented by P7C3-A20. (n=12 cell culture wells per group for VEH and H2O2; n=24 cell culture wells per group for H2O2+ P7C3-A20; scale bar = 100 µm). (F) Increased MitoSOX Red signal, a measure of mitochondrial superoxide level, in HBMVECs following H2O2exposure is prevented by P7C3-A20 (scale bar = 5 µm). Mitochondrial fragmentation caused by H202 exposure is also prevented by P7C3-A20 treatment. Area shown in dotted box indicates a higher magnification image of the indicated region (scale bar = 20 µm). (n=8 cell culture wells per group for VEH; n=7 cell culture wells per group for H2O2; n=14 cell culture wells per group for H2O2 + P7C3-A20). (G) Basal mitochondrial respiration rate in HBMVECs is constant across all groups. (n=7 cell culture wells per group). (H) Mitochondrial respiratory suppression in HBMVECs following H2O2 exposure is prevented by P7C3-A20. The protective effect of P7C3-A20 is blocked by FK866. (n=7 cell culture wells per group). (I) Reduced mitochondrial spare reserve capacity in HBMVECs following H2O2exposure is prevented by P7C3- A20. The protective effect of P7C3-A20 is blocked by FK866. (n=7 cell culture wells per group). (J) Reduced maximal mitochondrial respiration rate in HBMVECs following H2O2 exposure is prevented by P7C3- A20 treatment. The protective effect of P7C3-A20 is blocked by FK866. (n=7 cell culture wells per group). Each dot in a graph represents an individual set of experiments. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, data was analyzed by one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group for mice and H2O2VEH for cells. See also Fig.10.

[0028] Figs.5(A-U) illustrate magnitude of NAD+homeostatic disruption correlates with human and mouse AD severity. (A) NAD+homeostasis is disrupted in human AD cerebral cortex, relative to control subjects (n=15-18 per group, **p < 0.01, unpaired t-test). (B) Greater disruption in human brain NAD+homeostasis is associated with more p-Tau pathology. Also see Fig.10A. (C) Greater disruption in human brain NAD+homeostasis is associated with more oxidative damage, as evidenced by protein carbonylation levels. Also see Fig.10B. (D) Greater disruption in human brain NAD+homeostasis is associated with more neuroinflammation, as evidenced by GFAP levels. Also see Fig.10C. (E) Greater disruption in human brain NAD+homeostasis is associated with more BBB deterioration, as evidenced by ZO-1 levels. Also see Fig.10D. (F) Greater disruption in human brain NAD+homeostasis is associated with more loss, as evidenced by NeuN levels. Also see Fig.10E. (G) Greater disruption in human brain NAD+homeostasis shows a trend of association with more synaptic loss, as evidenced by PSD-95 levels. Also see Fig.10F. (H) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more p-Tau pathology. (I) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more oxidative damage, as evidenced by protein carbonylation levels. (J) Greater disruption in 6-month-old 5xFAD brain NAD+homeostasis is associated with more oxidative damage, as evidenced by protein carbonylation levels. (K) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more neuroinflammation, as evidenced by IL-2 levels. (L) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more neuroinflammation, as evidenced by IL-13 levels. (M) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more BBB deterioration, as evidenced by ZO-1 levels. (N) Greater disruption in 6-month-old 5xFAD brain NAD+homeostasis is associated with more greatly impaired memory, as evidenced by discrimination index in the NOR test. (O) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more greatly impaired memory, as evidenced by discrimination index in the NOR test. (P) Greater disruption in 6-month-old 5xFAD brain NAD+homeostasis is associated with more greatly impaired memory, as evidenced by the number of platform crossings in the probe memory test of the Morris water maze. (Q) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with more greatly impaired memory, as evidenced by the number of platform crossings in the probe memory test of the Morris water maze. (R) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with decreased ability to stay on the accelerating rotating rod, as evidenced by time until falling. (S) Greater disruption in 12-month-old 5xFAD brain NAD+homeostasis is associated with decreased ability to stay on the accelerating rotating rod, as evidenced by the rotation speed of the rod at falling. (T) Levels of the NAD+-synthesizing enzymes glutamine-dependent NAD+synthetase (NADSYN1) and nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) are reduced in human AD cerebral cortex, relative to control subjects, and present at normal levels in NDAN subjects (n= 73 for Control; 80 for AD; and 27 for NDAN; * p < 0.05, limma linear regression). (U) Levels of NAD+-consuming enzymes NAD kinase 2 (NADK2), poly (ADP-ribose) polymerase 4 (PARP4), and sirtuin 1 (SIRT1) are increased inhuman AD cerebral cortex, relative to and present at normal levels in NDAN subjects (n= 73 for Control; 80 for AD; and 27 for NDAN, ** p < 0.01, **** p<0.0001, limma linear regression). See also Fig.11.

[0029] Figs.6(A-M) illustrate identification of Molecular Signatures Responsible for AD Reversal After P7C3-A20 Treatment in 5xFAD Mice Through Label-Free Proteomics by NanoLC-MS / MS, and Correlation of AD Mice Proteome Targets to Human AD Proteome Database. (A) The volcano plot shows significant differentially expressed proteins (DEPs) in male and female 5xFAD VEH mice compared to WT VEH male and female mice. Upregulated proteins in 5xFAD VEH mice are shown in red, while downregulated proteins are shown in blue. The top ten upregulated and downregulated proteins, based on the most significant log10 p-value, are labelled. The sample size for each group is n=5 for both males and females. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (B) The volcano plot shows significant DEPs in male and female 5xFAD mice treated with P7C3-A20 compared to 5xFAD VEH mice. Upregulated proteins in the 5xFAD P7C3-A20 group are shown in red, while downregulated proteins are shown in blue. The top ten upregulated and downregulated proteins, based on the most significant log10 p-value, are labelled. The sample size for each group is n=5 for both males and females. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (C) The volcano plot shows significant DEPs in male and female WT P7C3-A20 mice compared to WT VEH male and female mice. Upregulated proteins in WT P7C3-A20 mice are shown in red, and downregulated proteins are shown in blue. The top ten upregulated and downregulated proteins, based on the most significant log10 p-value, are labelled. The sample size for each group is n=5 for both males and females. Proteins with a fold change of ± ≥1.25 and a p- value of ≤ 0.05 were considered significant. (D) Gene ontology analysis for significant DEPs in 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20 is shown. Y-axis represents each enrichment term, while X-axis shows the enrichment false discovery rate (FDR) for each term, with an FDR threshold of ≤0.05. The top five enrichment terms are shown. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). The size of the bubbles indicates the number of candidates associated with each pathway. Red color bar represents enriched terms for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched terms for downregulated proteins. (E) Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis forsignificant DEPs in 5xFAD VEH mice that restored to WT VEH levels by P7C3-A20 is shown. The top five enriched pathways are represented in the figure. Only three pathways were enriched for downregulated proteins, with an FDR of ≤0.1. Y-axis represents each pathway term, while X-axis represents the enrichment FDR. The bubble size reflects the number of candidates in each pathway. Red color bar indicates enriched pathways for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched pathways for downregulated proteins. (F) The top five Reactome pathway analyses for significant DEPs in 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20 are shown. Y-axis indicates each pathway term, while X-axis shows the enrichment FDR (≤0.1). Bubble size corresponds to the number of candidates in each pathway. Red color bar indicates enriched pathways for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched pathways for downregulated proteins. (G) The heat map shows significant DEPs in male and female 5xFAD VEH mice changing in the same direction as human AD brain that were restored to WT VEH levels in 5xFAD mice by P7C3-A20. (H) The heat map shows the NeuroPro score. Proteins consistently increased in an AD stage vs controls have a positive score, while proteins consistently decreased in an AD stage vs controls have a negative score. (I) Gene ontology analysis is shown for significant DEPs in human AD, as represented in Fig. 6H. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.1. The top five enrichment terms are shown. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for up-regulated proteins in human AD, while purple color represents enriched terms for down-regulated proteins. (J) Reactome pathway analysis is shown for significant DEPs in human AD, as represented in Fig.6H. Y-axis represents each pathway term, while X-axis represents the enrichment FDR for each term. FDR ≤ 0.1. The top five enrichment terms are represented in the graph. Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched pathways for up-regulated proteins in human AD, while purple color represents enriched pathways for down-regulated proteins in human AD. (K) Venn diagram shows the candidates changing in the same direction in human AD transcriptome, human AD proteome, and 5xFAD VEH mice that were restored to WT Veh levels by P7C3-A20. The 17 proteins changing in the same direction in human AD transcriptome and proteome are marked in the figure. (L) Geneontology analysis is shown for the 17 in Fig.6K. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.1. The top five enrichment terms are shown. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for up-regulated proteins in human AD, while purple color represents enriched terms for down-regulated proteins in human AD. (M) Reactome pathway analysis is shown for the 17 proteins marked in Fig.6K. Y-axis represents each pathway term, while X- axis represents the enrichment FDR for each term. FDR ≤ 0.05. The top five enrichment terms are represented in the graph. Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched pathways for up-regulated proteins in human AD, while purple color represents enriched pathways for down-regulated proteins in human AD. See also Figs.12 and 13.

[0030] Figs.7(A-O) illustrate P7C3-A20 treatment of presymptomatic 5xFAD mice prevents emergence of disrupted brain NAD+homeostasis, cognitive impairment, and impaired hippocampal synaptic plasticity. (A) Brain NAD+ / NADH ratio shows progressively greater reduction as disease advances in 5xFAD mice, relative to WT littermates, with a trend at pre-disease (2 months of age) and significantly greater reduction at mid-disease (6 months of age). P7C3-A20 preserves normal NAD+homeostasis in 5xFAD mice. NAD+homeostasis is not affected in WT littermate mice by P7C3-A20. Pre-disease mice were administered vehicle for 1 week, from age 7 – 8 weeks. Mid-disease mice were administered vehicle or P7C3-A20 for 4 months, from age 2 – 6 months. (n=3-6 female mice and 4 male mice per group). (B) Steady state plasma levels of P7C3-A20 are observed after four days of administration (10 mg / kg / day, intraperitoneal) to healthy WT mice, as shown by regular sampling out to 25 hours after the final dose. (n=3-6 female mice and 4-7 male mice per time point). (C) Steady state brain levels of P7C3-A20 are observed after four days of administration (10 mg / kg / day, intraperitoneal) to healthy WT mice, as shown by regular sampling out to 25 hours after the final dose. (n=3-6 female mice and 4-7 male mice per time point). (D) Brain NAD+homeostasis in healthy WT mice does not change after four days of administration of P7C3-A20 (10 mg / kg / day, intraperitoneal), as shown by regular sampling out to 25 hours after the final dose. (n=3-6 female mice and 4-7 male mice per time point). (E) Schematic of Alzheimer’s disease prevention study with P7C3-A20 in 5xFAD mice.(F) Memory in the novel object task, as measured by discrimination index, is impaired in 6- month-old mid-disease 5xFAD mice, relative to WT littermates. This memory deficit is prevented by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=19-26 female mice and 13-20 male mice per group). (G) In the Morris water maze (MWM) task, both learning (measured by latency time to fund the platform) and memory (measured by the number of platform crossings in the probe test) are impaired in 6- month-old mid-disease 5xFAD mice, relative to WT littermates. Both the learning and memory deficits are reversed by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=20-25 female mice and 20-25 male mice per group). (H) There are no genotype or treatment-specific differences in learning or memory (probe test) phases of the accelerating rotarod test in 6-month-old mice in any measures. (n=16-20 female mice and 16-20 male mice per group). (I) Six-month-old mid-disease 5xFAD mice display abnormal anxiolytic-like activity in the elevated plus maze, as evidenced by spending more time in the open arms and less time in the closed arms, relative to WT littermates. This deficit is prevented by P7C3-A20. WT littermate mice are not affected in this task by P7C3-A20. (n=17-20 female mice and 16-20 male mice per group). (J) There are no genotype or treatment-specific differences is 6-month-old mice in the forced swim test (FST) of depression-like behavior. (n=7-11 female mice and 11-19 male mice per group). (K) Schematic of electrophysiological recording from ex vivo mouse brain slices of the CA3- CA1 synapse, which is involved in learning. The stimulating electrode was placed in the CA3 region to stimulate the Schaffer collaterals, and the recording electrode was placed in the stratum radiatum of the CA1 region. (L) Input-output curve is not affected by genotype or treatment group in 6-month-old mice. (n= 43 slices from 6 WT VEH female mice; n=41 slices from 65xFAD VEH female mice; n=31 slices from 6 WT P7C3-A20 female mice; n- =32 slices from 65xFAD P7C3-A20 female mice). (M) Input-output curve is not affected by genotype or treatment group in 12-month-old mice. (n=39 slices from 5 WT VEH female mice; n=49 slices from 75xFAD VEH female mice; n=40 slices from 5 WT P7C3-A20 female mice; n-=36 slices from 55xFAD P7C3-A20 female mice). (N) Hippocampal long- term potentiation (LTP) after theta-burst stimulation is impaired in 6-month-old mid-disease 5xFAD mice, relative to WT littermates. This is prevented by P7C3-A20. (n= 35 slices from 6 WT VEH female mice; n=44 slices from 65xFAD VEH female mice; n=37 slices from 6 WT P7C3-A20 female mice; n=28 slices from 65xFAD P7C3-A20 female mice). (O) Meanpotentiation during the last 10 min of is impaired in 6-month-old mid-disease 5xFAD mice, relative to WT littermates. This is prevented by P7C3-A20. (n= 35 slices from 6 WT VEH female mice; n=44 slices from 65xFAD VEH female mice; n=37 slices from 6 WT P7C3-A20 female mice; n-=28 slices from 65xFAD P7C3-A20 female mice). There are no sex-specific differences in any groups. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p < 0.05,**p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group, with two-way ANOVA for learning phase in (G) and for (N). See also Fig.1.

[0031] Figs.8(A-I) illustrate early P7C3-A20 treatment of young asymptomatic 5xFAD mice reduces amyloid plaque accumulation and prevents emergence of BBB deterioration. (A) Accumulation of pathological amyloid structure plaques in 6-month-old 5xFAD mice is reduced by P7C3-A20 in cerebral cortex and hippocampus, as shown by ThioS-positive % area. WT littermate mice are not affected by P7C3-A20. (n=4 females per group, scale bar = 200 µm). (B) Aβ aggregate accumulation in 6-month-old 5xFAD mice is not affected by P7C3-A20, as evidenced by quantification of 6E10-postive % area, which was stained in the same sections as used for This-staining in (A). WT littermate mice are not affected by P7C3- A20. (n=4 females per group, scale bar = 200 µm). (C) Western blot APP and p-tau (Ser202 / Thr205) in cerebral cortex of 6-month-old mice (GAPDH protein was used as loading control). P-tau levels are the same across all groups. P7C3-A20 does not affect expression levels of APP in 5xFAD mice. (n=4 females and 4 males per group). (D) Elevated levels of soluble brain Aβ1-40 and Aβ1-42 in 6-month-old 5xFAD mice are not affected by P7C3- A20. WT littermate mice are not affected by P7C3-A20. (n=4 females and 4 males per group). (E) Elevated levels of insoluble brain Aβ1-40 and Aβ1-42 in 6-month-old 5xFAD mice are not affected by P7C3- A20. WT littermate mice are not affected by P7C3-A20. (n=4 females and 4 males per group). (F) Increased open space around blood vessels due to astrocytic end feet disruption (as shown by red arrows on representative transmission electron microscopy (TEM) images) in the cerebral cortex BBB of 6-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 1µm). (G) Increased infiltration of IgG into brain parenchyma of cerebral cortex and hippocampus in 6-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=4 females and 4 males per group,scale bar = 20µm). (H) Reduced pericyte (CD 13, red) of blood vessel endothelial cells (CD 31, green) in cortex and hippocampus of 6-month-old 5xFAD mice is prevented by P7C3-A20 treatment. WT littermate mice are not affected by P7C3-A20. (n= 3-4 females and 3-4 males per group, scale bars = 20µm). (I) ZO-1 levels are not affected in 6-month-old mice by genotype or treatment. (n=5 females and 5 males per group). There are no sex- specific differences in any group. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p < 0.05,**p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group.

[0032] Figs.9(A-F) illustrate early P7C3-A20 treatment of young asymptomatic 5xFAD mice prevents emergence of DNA damage, neuroinflammation, and young neuronal cell death. (A) DNA damage in the hippocampus, as measured by TUNEL staining (green signal), is elevated in 6-month-old 5xFAD mice and prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (representative CA1 regions shown, n=4 females per group, scale bar = 200µm). (B) GFAP expression (green signal) in cerebral cortex and hippocampus is elevated in 6-month-old 5xFAD mice and partially prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3-4 female mice and 3- 4 male mice per group, scale bar = 50µm). (C) IBA1 (red signal) in cerebral cortex and hippocampus is elevated in 6-month-old 5xFAD mice, and partially prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=4 male mice and 4 female mice per group, scale bar = 50 µm). (D) IL-2, IL-13, TNF-α, and IFN-γ cytokine levels in the hippocampus are not altered in 6-month-old mice as a function of genotype or treatment. (n=4-5 female mice per group). (E) Mature neuronal survival, as evidenced by NeuN staining in cerebral cortex and hippocampus, is not altered in 6-month-old 5xFAD mice, as a function of genotype or treatment. Neither vehicle or P7C3-A20-treated groups do not show neuronal cell death, as evidenced by quantification of immunohistochemical staining of NeuN in cerebral cortex and hippocampus. (n=4 males and 3-4 females per group, scale bar = 50 µm). (F) Survival of young hippocampal neurons labeled with BrdU is increased by P7C3-A20 in all 6-month-old mice, with a trend towards decreased survival in 5xFAD VEH mice. (n=4-6 females and 4-6 females per group, scale bar = 50µm). There are no sex-specific differences in any group. In all graphs, each dot represents an individual sample. For mouse samples, females are blue and males are red. All error bars are standard error of the mean. *p<0.05, ***p < 0.001,****p < 0.0001, one-way ANOVA and multiple comparisons against 5xFAD VEH group.

[0033] Figs.10(A-D) illustrate early P7C3-A20 treatment of young asymptomatic 5xFAD mice prevents emergence of oxidative stress. (A) Elevated lipid peroxidation (4- HNE) in the cerebral cortex and hippocampus of 6-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 50µm). (B) Elevated protein nitration (3-N-Tyr) in the cerebral cortex and hippocampus of 6-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (n=3 females per group, scale bar = 50µm). (C) Elevated protein carbonylation (2,4-dinitrophenlhydrazine (DNPH)) in cortex of 6-month-old 5xFAD mice is prevented by P7C3-A20. WT littermate mice are not affected by P7C3-A20. (β-actin was loading control; each lane is a separate animal, n=5 females per group). (D) Elevated protein carbonylation (DNPH) in cortex of 12-month-old 5xFAD mice is reversed by P7C3- A20. WT littermate mice are not affected by P7C3-A20. (β-actin was loading control; each lane is a separate animal, n=5 females per group). In all graphs, each dot represents an individual sample. For mouse samples, females are blue dots. All error bars are standard error of the mean. *p<0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, one-way ANOVA and Dunnet multiple comparisons against 5xFAD VEH group.

[0034] Figs.11(A-Q) illustrate pathology in human AD cerebral cortex; NAD+-related enzyme expression levels in human AD and NDAN brain; and P7C3-A20-mediated recovery aged symptomatic PS19 mice. (A) Western blot shows pathological tau phosphorylation (p- Tau at Ser202and Thr205) in human AD cerebral cortex and absence of p-tau in control subjects. The top panel entails samples from the Case Western Reserve University (CWRU) collection, and the bottom panel entails samples from the Northwestern University (NWU) collection. (**p < 0.01, unpaired t-test). (B) Western blot shows increased protein carbonylation in human AD cerebral cortex, relative to control subjects. β-actin was used as loading control, and quantification of western blot is shown. Individual human samples are depicted as individual lanes on the western blots and as dots on the graph. (****p < 0.0001, unpaired t-test). (C) Western blot shows increased GFAP in human AD cerebral cortex, relative to control subjects. GAPDH was used as loading control, and quantification of western blot is shown. Individual human samples are depicted as individual lanes on the western blots and as dots on the graph. (****p < 0.0001, unpaired t-test). (D) Western blotshows decreased ZO-1 in human AD relative to control subjects. GAPDH was used as loading control, and quantification of western blot is shown. Individual human samples are depicted as individual lanes on the western blots and as dots on the graph. (*p < 0.05, unpaired t-test). (E) Western blot shows decreased NeuN in human AD cerebral cortex, relative to control subjects. GAPDH was used as loading control, and quantification of western blot is shown. Individual human samples are depicted as individual lanes on the western blots and as dots on the graph. (**p < 0.01, unpaired t-test). (F) Western blot shows decreased PSD-95 in human AD cerebral cortex, relative to control subjects. GAPDH was used as loading control, and quantification of western blot is shown. Individual human samples are depicted as individual lanes on the western blots and as dots on the graph. (*p < 0.05, unpaired t-test). (G) The NAD+-synthesizing enzyme nicotinamide riboside kinase 1 (NMRK1) shows a non-significant downward trend in expression and the NAD+-consuming enzymes 5'-nucleotidase, cytosolic II (NT5C2) and sirtuin 4 (SIRT4) show a non-significant upward trend in human AD brain cerebral cortex, relative to normal control subjects. There were no significant expression differences between NDAN subjects and control subjects (n= 73 for Control, 80 for AD, and 27 for NAND, limma linear regression). (H) Schematic of experimental design testing the ability of P7C3-A20 to reverse advanced disease in PS19 mice. At 11 months of age, PS19 mice were randomly divided into VEH and P7C3-A20 (10 mg / kg / day) treatment groups, with P73-A20 treatment group emerging slightly biased towards more impaired cognition than the VEH treated group at baseline. Mice were then tested again in the NOR test of cognition after 15 and 30 days of treatment with P7C3-A20 or vehicle, followed by sacrifice and analysis of brain tissue for levels of NAD+ / NADH and protein carbonylation. (I) At 11 months of age, PS19 mice show reduced cognition in the novel object recognition (NOR) test, as evidenced by decreased discrimination index relative to WT littermates. (*p < 0.05, unpaired t-test, n=4 male PS19 mice and 3 female PS19 mice, n= 10 male wild type littermates and 9 female wild type littermates). (J) Discrimination index in the NOR test of 11-month-old advanced-disease PS19 mice was evenly distributed when animals were randomly designated for either P7C3-A20-mediated stabilization of NAD+homeostasis, or vehicle treatment. Although there was no statistical difference between the groups, the animals designated for P7C3-A20 showed a trend towards more greatly impaired cognitive performance than those designated to receive vehicle (n=3 male PS19 VEH; n=1 female PS19 VEH, n= 1 male PS19 P7C3-A20; n=2 female PS19 P7C3-A20). (K) After 15 days of P7C3-A20, old PS19 mice show improvement in the NOR test, as evidenced by no statistically significant difference in discrimination index between PS19 P7C3-A20 mice and WT VEH mice. There was no statistically significant difference in discrimination index between PS19 P7C3-A20 mice and PS19 VEH mice. (**p < 0.01, one-way ANOVA and Dunnet multiple comparisons against PS19 VEH group, n=9 female WT littermate VEH; n=10 male WT littermate VEH, n=1 female PS19 VEH; n=2 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (L) After 30 days of P7C3-A20, 12-month-old PS19 mice showed full recovery of function in the NOR test, as evidenced by statistically significantly higher discrimination index than PS19 VEH mice and no statistically significant difference in discrimination index between PS19 P7C3- A20 mice and WT littermate VEH mice. (*p < 0.05, ***p < 0.001, one-way ANOVA and Dunnet multiple comparisons against PS19 VEH group, n=9 female WT littermate VEH; n=10 male WT littermate VEH, n=1 female PS19 VEH; n=2 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (M) Disrupted NAD+homeostasis in 12- month-old PS19 VEH mice, relative to WT littermate VEH mice, is restored to normal by P7C3-A20. (*p < 0.05, one-way ANOVA and Dunnet multiple comparisons against PS19 VEH group, n=4 female WT littermate VEH; n=4 male WT littermate VEH; n=1 female PS19 VEH; n=3 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (N) Reduced ZO-1 in 12-month-old PS19 mice is normalized by P7C3-A20. (*p < 0.05, one- way ANOVA and Dunnet multiple comparisons against PS19 VEH group, n=4 female WT littermate VEH; n=3 male WT littermate VEH; n=1 female PS19 VEH; n=3 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (O) Increased protein carbonylation in hippocampus of 12-month-old PS19 mice is reduced to normal by P7C3- A20. β-actin protein was used to normalize protein levels. (*p < 0.05, one-way ANOVA and Dunnet multiple comparisons against PS19 VEH group, n=4 female WT littermate VEH; n=1 female PS19 VEH; n=3 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (P) Increased IBA1 in PS19 mice is not affected by P7C3-A20. (**p < 0.05, one-way ANOVA and Dunnet multiple comparisons against WT VEH group; n=4 female WT littermate VEH; n=3 male WT littermate VEH; n=1 female PS19 VEH; n=3 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3-A20). (Q) Increased total tau protein in PS19 mice is not affected by P7C3-A20. (**p < 0.01, ***p < 0.001one-way ANOVA and Dunnet multiple comparisons against WT VEH group; n=4 female WTlittermate VEH; n=3 male WT littermate n=1 female PS19 VEH; n=3 male PS19 VEH; n=2 female PS19 P7C3-A20; n=1 male PS19 P7C3- A20). In all graphs, each dot represents an individual mouse or human subject. All error bars are standard error of the mean.

[0035] Figs.12(A-L) illustrate identification of molecular signatures responsible for AD reversal after P7C3-A20 treatment to female 5xFAD mice through label-free proteomics by nanoLC-MS / MS, and correlation of AD mice proteome targets to AD human proteome database. (A) The volcano plot shows significant differentially expressed proteins (DEPs) in female 5xFAD VEH mice compared to WT VEH female mice. Upregulated proteins in 5xFAD VEH mice are shown in red while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (B) The volcano plot shows significant DEPs in female 5xFAD P7C3-A20 mice compared to 5xFAD VEH female mice. Upregulated proteins in 5xFAD P7C3-A20 mice are shown in red while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p value of ≤ 0.05 were considered significant. (C) The volcano plot shows significant DEPs in female WT P7C3-A20 mice compared to WT VEH female mice. Upregulated proteins in WT P7C3-A20 mice are shown in red while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p value of ≤ 0.05 were considered significant. (D) The heat map shows significant DEPs in female 5xFAD VEH mice that were restored to WT VEH levels in 5xFAD mice by P7C3-A20. (E) Gene ontology analysis is shown for significant DEPs in female 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.1. The top five enrichment terms are represented in each graph. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched terms for downregulated proteins. (F) Kyoto Encyclopedia of Genes and Genomes (KEGG) pathwayanalysis is shown for significant DEPs in 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20. The top four enriched pathways are represented in the figure, as only four pathways were enriched for upregulated and downregulated proteins. Y-axis represents each pathway term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.1. Bubble size reflects the number of candidates belonging to that pathway. Red color bar represents enriched pathways for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched pathways for downregulated proteins. (G) The top five Reactome pathway analyses for significant DEPs in female 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20 are shown. Y-axis indicates each pathway term, while X-axis shows the enrichment FDR (≤0.1). Bubble size corresponds to the number of candidates in each pathway. Red color bar signifies enriched pathways for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched pathways for downregulated proteins. (H) The heat map shows significant DEPs in female 5xFAD VEH mice changing in the same direction as human AD brain transcriptome data that were restored to WT VEH levels in 5xFAD mice by P7C3-A20. (I) The heat map shows differentially expressed human AD snRNA in middle temporal gyrus (MTG) and dorsolateral prefrontal cortex (DLPFC) changing in the same direction as female 5xFAD VEH mice and restored to WT VEH levels by P7C3-A20. (J) Gene ontology analysis is shown for significant DEPs in female 5xFAD VEH mice changing in the same direction as differentially expressed human AD snRNA and restored to WT VEH levels in female 5xFAD mice by P7C3-A20. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.05. (K) The top five enrichment terms are shown. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched terms for downregulated proteins. The top five Reactome pathway analyses for significant DEPs in female 5xFAD VEH mice changing in the same direction as differentially expressed human AD snRNA and restored to WT VEH levels in female 5xFAD mice by P7C3-A20 are shown. Y-axis indicates each pathway term, while X-axis shows the enrichment FDR (≤0.05). Bubble size corresponds to the number of candidates in each pathway. Red color bar signifies enriched pathways for upregulated proteins in 5xFAD VEH mice, while blue color represents enriched pathways for downregulated proteins. (L) Venndiagram shows the candidates changing in direction in human AD transcriptome, human AD proteome, and female 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20. The 11 proteins changing in the same direction in human AD transcriptome and proteome are marked in the figure.

[0036] Figs.13(A-L) illustrate the identification of molecular signatures responsible for AD reversal after P7C3-A20 treatment to male 5xFAD mice through label-free proteomics by nanoLC-MS / MS and correlation of AD mice proteome targets to AD human proteome database. (A) The volcano plot shows significant differentially expressed proteins (DEPs) in male 5xFAD VEH mice compared to WT VEH male mice. Upregulated proteins in 5xFAD VEH mice are shown in red, while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (B) The volcano plot shows significant DEPS in male 5xFAD P7C3-A20 mice compared to 5xFAD VEH male mice. Upregulated proteins in 5xFAD P7C3-A20 mice are shown in red, while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (C) The volcano plot shows significant DEPs in male WT P7C3-A20 mice compared to WT VEH male mice. Upregulated proteins in WT P7C3-A20 mice are shown in red, while downregulated proteins are shown in blue. The top ten upregulated and down-regulated proteins, based on the most significant log10p-value, are labelled. The sample size for each group is n=5. Proteins with a fold change of ± ≥1.25 and a p-value of ≤ 0.05 were considered significant. (D) The heat map shows significant DEPs in male 5xFAD VEH male mice that were restored to WT VEH levels in 5xFAD mice by P7C3-A20. (E) Gene ontology analysis is shown for significant DEPs in male 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.05. The top five enrichment terms are represented in each graph. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for upregulated proteins in 5xFAD VEH mice, while the blue color represents enriched terms fordownregulated proteins. (F) Kyoto of Genes and Genomes (KEGG) pathway analysis is shown for significant DEPs in male 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20 reverted toward WT VEH after daily P7C3- A20 treatment from 6 to 12 months. The top five enriched pathways are represented in the figure, and only two pathways were enriched for downregulated proteins. Y-axis represents each pathway term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.1. Bubble size reflects the number of candidates who belong to that pathway. Red color bar represents enriched pathways for upregulated proteins in 5xFAD VEH mice, while the blue color represents enriched pathways for downregulated proteins. (G) The top five Reactome pathway analyses for significant DEPs in male 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20 are shown. Y-axis indicates each pathway term, while X-axis shows the enrichment FDR (≤0.1). Bubble size corresponds to the number of candidates in each pathway. Red color bar signifies enriched pathways for upregulated proteins in 5xFAD VEH mice, while the blue color represents enriched pathways for downregulated proteins. (H) The heat map shows significant DEPs in male 5xFAD VEH mice changing in the same direction as human AD brain transcriptome data that were restored to WT VEH levels in 5xFAD mice by P7C3-A20. (I) The heat map shows differentially expressed human AD snRNA in the middle temporal gyrus (MTG) and dorsolateral prefrontal cortex (DLPFC) changing in the same direction as male 5xFAD VEH mice and restored to WT VEH levels by P7C3-A20. (J) Gene ontology analysis is shown for significant DEPs in male 5xFAD VEH mice changing in the same direction as differentially expressed human AD snRNA and restored to WT VEH levels in male 5xFAD mice by P7C3-A20. Y-axis represents each enrichment term, while X-axis represents the enrichment FDR for each term, with an FDR threshold of ≤0.05. The top five enrichment terms are shown. Terms are categorized as biological processes (BP), cellular components (CC), and molecular functions (MF). Bubble size represents the number of candidates belonging to that pathway. Red color bar represents enriched terms for upregulated proteins in 5xFAD VEH mice, while the blue color represents enriched terms for downregulated proteins. (K) The top five Reactome pathway analyses for significant DEPs in male 5xFAD VEH mice changing in the same direction as differentially expressed human AD snRNA and restored to WT VEH levels in male 5xFAD VEH mice by P7C3-A20 are shown. Y-axis indicates each pathway term, while X-axis shows the enrichment FDR (≤0.05). Bubble size corresponds to the number of candidates in eachpathway. Red color bar signifies enriched for upregulated proteins in 5xFAD VEH mice, while the blue color represents enriched pathways for downregulated proteins. (L) Venn diagram shows the candidates changing in the same direction in human AD transcriptome, human AD proteome, and male 5xFAD VEH mice that were restored to WT VEH levels by P7C3-A20. The 6 proteins changing in the same direction in the human AD transcriptome and proteome are marked in the figure. DETAILED DESCRIPTION

[0037] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0038] The terms "comprise," "comprising," "include," "including," "have," and "having" are used in the inclusive, open sense, meaning that additional elements may be included. The terms "such as", "e.g.," as used herein are non-limiting and are for illustrative purposes only. "Including" and "including but not limited to" are used interchangeably.

[0039] The term "or" as used herein should be understood to mean "and / or” unless the context clearly indicates otherwise.

[0040] As used herein, the term "about" or "approximately" refers to a quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much as 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2% or 1% to a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length. In one embodiment, the term "about" or "approximately" refers a range of quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length ± 15%, ± 10%, ± 9%, ± 8%, ± 7%, ± 6%, ± 5%, ± 4%, ± 3%, ± 2%, or ± 1% about a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length.

[0041] As used herein, “one or more of a, b, and c” means a, b, c, ab, ac, bc, or abc. The use of “or” herein is the inclusive or.

[0042] “An effective amount” refers to an amount of a compound that confers a therapeutic effect (e.g., treats, e.g., controls, relieves, ameliorates, alleviates, or slows the progression of; or prevents, e.g., delays the onset of or reduces the risk of developing, a disease, disorder, or condition or symptoms thereof) on the treated subject. The therapeutic effect may be objective (i.e., measurable by some test or marker) or subjective (i.e., thesubject gives an indication of or feels an . An effective amount of the compound described above may range from about 0.01 mg / kg to about 1000 mg / kg (e.g., from about 0.1 mg / kg to about 100 mg / kg, from about 1 mg / kg to about 100 mg / kg). Effective doses will also vary depending on the route of administration, as well as the possibility of co-usage with other agents.

[0043] The term “halo” or “halogen” refers to any radical of fluorine, chlorine, bromine, or iodine.

[0044] In general, and unless otherwise indicated, substituent (radical) prefix names are derived from the parent hydride by either (i) replacing the “ane” in the parent hydride with the suffixes “yl,” “diyl,” “triyl,” “tetrayl,” etc.; or (ii) replacing the “e” in the parent hydride with the suffixes “yl,” “diyl,” “triyl,” “tetrayl,” etc. (here the atom(s) with the free valence, when specified, is (are) given numbers as low as is consistent with any established numbering of the parent hydride). Accepted contracted names, e.g., adamantyl, naphthyl, anthryl, phenanthryl, furyl, pyridyl, isoquinolyl, quinolyl, and piperidyl, and trivial names, e.g., vinyl, allyl, phenyl, and thienyl, are also used herein throughout. Conventional numbering / lettering systems are also adhered to for substituent numbering and the nomenclature of fused, bicyclic, tricyclic, and polycyclic rings.

[0045] The following definitions are used, unless otherwise described. Specific and general values listed below for radicals, substituents, and ranges are for illustration only; they do not exclude other defined values or other values within defined ranges for the radicals and substituents. Unless otherwise indicated, alkyl, alkoxy, alkenyl, and the like denote both straight and branched groups.

[0046] The term “alkyl” refers to a saturated hydrocarbon chain that may be a straight chain or branched chain, containing the indicated number of carbon atoms. For example, C1- C6 alkyl indicates that the group may have from 1 to 6 (inclusive) carbon atoms in it. Any atom can be optionally substituted, e.g., by one or more substituents. Examples of alkyl groups include, without limitation, methyl, ethyl, n-propyl, isopropyl, and tert-butyl.

[0047] As used herein, the term “straight chain Cn-malkylene,” employed alone or in combination with other terms, refers to a non-branched divalent alkyl linking group having n to m carbon atoms. Any atom can be optionally substituted, e.g., by one or more substituents. Examples include methylene (i.e., —CH2—).

[0048] The term “haloalkyl” refers to group, in which at least one hydrogen atom is replaced by halo. In some embodiments, more than one hydrogen atom (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14) are replaced by halo. In these embodiments, the hydrogen atoms can each be replaced by the same halogen (e.g., fluoro) or the hydrogen atoms can be replaced by a combination of different halogens (e.g., fluoro and chloro). “Haloalkyl” also includes alkyl moieties in which all hydrogens have been replaced by halo (sometimes referred to herein as perhaloalkyl, e.g., perfluoroalkyl, such as trifluoromethyl). Any atom can be optionally substituted, e.g., by one or more substituents.

[0049] As referred to herein, the term “alkoxy” refers to a group of formula —O(alkyl). Alkoxy can be, for example, methoxy (—OCH3), ethoxy, propoxy, isopropoxy, butoxy, iso- butoxy, sec-butoxy, pentoxy, 2-pentoxy, 3-pentoxy, or hexyloxy. Likewise, the term “thioalkoxy” refers to a group of formula —S(alkyl). Finally, the terms “haloalkoxy” and “thioalkoxy” refer to —O(haloalkyl) and —S(haloalkyl), respectively. The term “sulfhydryl” refers to —SH. As used herein, the term “hydroxyl,” employed alone or in combination with other terms, refers to a group of formula —OH.

[0050] The term “aralkyl” refers to an alkyl moiety in which an alkyl hydrogen atom is replaced by an aryl group. One of the carbons of the alkyl moiety serves as the point of attachment of the aralkyl group to another moiety. Any ring or chain atom can be optionally substituted, e.g., by one or more substituents. Non-limiting examples of “aralkyl” include benzyl, 2-phenylethyl, and 3-phenylpropyl groups.

[0051] The term “alkenyl” refers to a straight or branched hydrocarbon chain containing the indicated number of carbon atoms and having one or more carbon-carbon double bonds. Any atom can be optionally substituted, e.g., by one or more substituents. Alkenyl groups can include, e.g., vinyl, allyl, 1-butenyl, and 2-hexenyl. One of the double bond carbons can optionally be the point of attachment of the alkenyl substituent.

[0052] The term “alkynyl” refers to a straight or branched hydrocarbon chain containing the indicated number of carbon atoms and having one or more carbon-carbon triple bonds. Alkynyl groups can be optionally substituted, e.g., by one or more substituents. Alkynyl groups can include, e.g., ethynyl, propargyl, and 3-hexynyl. One of the triple bond carbons can optionally be the point of attachment of the alkynyl substituent.

[0053] The term “heterocyclyl” refers to a fully saturated monocyclic, bicyclic, tricyclic or other polycyclic ring system having one or more constituent heteroatom ring atomsindependently selected from O, N (it is that one or two additional groups may be present to complete the nitrogen valence and / or form a salt), or S. The heteroatom or ring carbon can be the point of attachment of the heterocyclyl substituent to another moiety. Any atom can be optionally substituted, e.g., by one or more substituents. Heterocyclyl groups can include, e.g., tetrahydrofuryl, tetrahydropyranyl, piperidyl (piperidino), piperazinyl, morpholinyl (morpholino), pyrrolinyl, and pyrrolidinyl. By way of example, the phrase “heterocyclic ring containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms is independently selected from N, NH, N(C1-C6alkyl), NC(O)(C1-C6alkyl), O, and S; and wherein said heterocyclic ring is optionally substituted with from 1-3 independently selected Ra” would include (but not be limited to) tetrahydrofuryl, tetrahydropyranyl, piperidyl (piperidino), piperazinyl, morpholinyl (morpholino), pyrrolinyl, and pyrrolidinyl.

[0054] The term “heterocycloalkenyl” refers to partially unsaturated monocyclic, bicyclic, tricyclic, or other polycyclic hydrocarbon groups having one or more (e.g., 1-4) heteroatom ring atoms independently selected from O, N (it is understood that one or two additional groups may be present to complete the nitrogen valence and / or form a salt), or S. A ring carbon (e.g., saturated or unsaturated) or heteroatom can be the point of attachment of the heterocycloalkenyl substituent. Any atom can be optionally substituted, e.g., by one or more substituents. Heterocycloalkenyl groups can include, e.g., dihydropyridyl, tetrahydropyridyl, dihydropyranyl, 4,5-dihydrooxazolyl, 4,5-dihydro-1H-imidazolyl, 1,2,5,6- tetrahydro-pyrimidinyl, and 5,6-dihydro-2H-[1,3]oxazinyl.

[0055] The term “cycloalkyl” refers to a fully saturated monocyclic, bicyclic, tricyclic, or other polycyclic hydrocarbon groups. Any atom can be optionally substituted, e.g., by one or more substituents. A ring carbon serves as the point of attachment of a cycloalkyl group to another moiety. Cycloalkyl moieties can include, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, and norbornyl (bicycle[2.2.1]heptyl).

[0056] The term “cycloalkenyl” refers to partially unsaturated monocyclic, bicyclic, tricyclic, or other polycyclic hydrocarbon groups. A ring carbon (e.g., saturated or unsaturated) is the point of attachment of the cycloalkenyl substituent. Any atom can be optionally substituted, e.g., by one or more substituents. Cycloalkenyl moieties can include, e.g., cyclohexenyl, cyclohexadienyl, or norbornenyl.

[0057] As used herein, the term “cycloalkylene” refers to a divalent monocyclic cycloalkyl group having the indicated number of ring atoms.

[0058] As used herein, the term refers to a divalent monocyclic heterocyclyl group having the indicated number of ring atoms.

[0059] The term “aryl” refers to an aromatic monocyclic, bicyclic (2 fused rings), or tricyclic (3 fused rings), or polycyclic (>3 fused rings) hydrocarbon ring system. One or more ring atoms can be optionally substituted, e.g., by one or more substituents. Aryl moieties include, e.g., phenyl and naphthyl.

[0060] The term “heteroaryl” refers to an aromatic monocyclic, bicyclic (2 fused rings), tricyclic (3 fused rings), or polycyclic (>3 fused rings) hydrocarbon groups having one or more heteroatom ring atoms independently selected from O, N (it is understood that one or two additional groups may be present to complete the nitrogen valence and / or form a salt), or S. One or more ring atoms can be optionally substituted, e.g., by one or more substituents.

[0061] Examples of heteroaryl groups include, but are not limited to, 2H-pyrrolyl, 3H- indolyl, 4H-quinolizinyl, acridinyl, benzo[b]thienyl, benzothiazolyl, β-carbolinyl, carbazolyl, coumarinyl, chromenyl, cinnolinyl, dibenzo[b,d]furanyl, furazanyl, furyl, imidazolyl, imidizolyl, indazolyl, indolyl, isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthyridinyl, oxazolyl, perimidinyl, phenanthridinyl, phenanthrolinyl, phenarsazinyl, phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolyl, quinoxalinyl, thiadiazolyl, thianthrenyl, thiazolyl, thienyl, triazolyl, and xanthenyl.

[0062] The terms “arylcycloalkyl” and “arylheterocyclyl” refer to bicyclic, tricyclic, or other polycyclic ring systems that include an aryl ring fused to a cycloalkyl and heterocyclyl, respectively. Similarly, the terms “heteroarylheterocyclyl” and “heteroarylcycloalkyl” refer to bicyclic, tricyclic, or other polycyclic ring systems that include a heteroaryl ring fused to a heterocyclyl and cycloalkyl, respectively. Any atom can be substituted, e.g., by one or more substituents. For example, arylcycloalkyl can include indanyl; arylheterocyclyl can include 2,3-dihydrobenzofuryl, 1,2,3,4-tetrahydroisoquinolyl, and 2,2-dimethylchromanyl.

[0063] The descriptors “C═O” or “C(O)” refers to a carbon atom that is doubly bonded to an oxygen atom.

[0064] The term “oxo” refers to double-bonded oxygen when a substituent on carbon. When oxo is a substituent on nitrogen or sulfur, it is understood that the resultant groups has the structures N-O−and S(O) and SO2, respectively.

[0065] As used herein, the term employed alone or in combination with other terms, refers to a group of formula —CN, wherein the carbon and nitrogen atoms are bound together by a triple bond.

[0066] In general, when a definition for a particular variable includes both hydrogen and non-hydrogen (halo, alkyl, aryl, etc.) possibilities, the term “substituent(s) other than hydrogen” refers collectively to the non-hydrogen possibilities for that particular variable.

[0067] The term “substituent” refers to a group “substituted” on, e.g., an alkyl, haloalkyl, cycloalkyl, heterocyclyl, heterocycloalkenyl, cycloalkenyl, aryl, or heteroaryl group at any atom of that group. In one aspect, the substituent(s) on a group are independently any one single, or any combination of two or more of the permissible atoms or groups of atoms delineated for that substituent. In another aspect, a substituent may itself be substituted with any one of the above substituents.

[0068] Further, as used herein, the phrase “optionally substituted” means unsubstituted (e.g., substituted with a H) or substituted. As used herein, the term “substituted” means that a hydrogen atom is removed and replaced by a substituent. It is understood that substitution at a given atom is limited by valency.

[0069] Descriptors such as “C6-C10aryl that is optionally substituted with from 1-4 independently selected Rb” (and the like) is intended to include both an unsubstituted C6-C10 aryl group and a C6-C10aryl group that is substituted with from 1-4 independently selected Rb. The use of a substituent (radical) prefix names such as alkyl without the modifier “optionally substituted” or “substituted” is understood to mean that the particular substituent is unsubstituted. However, the use of “haloalkyl” without the modifier “optionally substituted” or “substituted” is still understood to mean an alkyl group, in which at least one hydrogen atom is replaced by halo.

[0070] In some embodiments, Rbcan be as defined in any one, two, three, or all of (aa) through (dd). For example, Rbcan be as defined in (aa) and (bb) or combinations thereof.

[0071] The phrase “Cy is a saturated, partially unsaturated or aromatic carbocyclic or heterocyclic ring system” in the definition of Reis understood to include each of the ring systems defined above (e.g., Cy can be coumarinyl or the ring component of biotin optionally substituted as defined anywhere herein).

[0072] The term "administering" to a patient includes dispensing, delivering or applying an active compound in a pharmaceutical formulation to a subject by any suitableroute for delivery of the active compound desired location in the subject (e.g., to thereby contact a desired cell), including administration into the cerebrospinal fluid or across the blood-brain barrier, delivery by either the parenteral or oral route, intramuscular injection, subcutaneous or intradermal injection, intravenous injection, buccal administration, transdermal delivery and administration by the rectal, colonic, vaginal, intranasal or respiratory tract route.

[0073] The terms “treating” and “treatment” as used herein refer to reduction in severity and / or frequency of symptoms, elimination of symptoms and / or underlying cause, and improvement or remediation of damage.

[0074] By “pharmaceutically acceptable” is meant a material that is not biologically or otherwise undesirable, i.e., the material may be incorporated into a pharmaceutical composition administered to a patient without causing any undesirable biological effects or interacting in a deleterious manner with any of the other components of the composition in which it is contained. When the term “pharmaceutically acceptable” is used to refer to a pharmaceutical carrier or excipient, it is implied that the carrier or excipient has met the required standards of toxicological and manufacturing testing and / or that it is included on the Inactive Ingredient Guide prepared by the U.S. Food and Drug Administration.

[0075] The phrases "systemic administration," "administered systemically," "peripheral administration" and "administered peripherally" as used herein mean the administration of a compound, drug or other material other than directly into a target tissue, such that it enters the animal's system and, thus, is subject to metabolism and other like processes, for example, subcutaneous administration.

[0076] The term "patient," or "subject," or "animal," or "host," or “individual” refers to any mammal. The subject may be a human but can also be a mammal in need of veterinary treatment, e.g., domestic animals (e.g., dogs, cats, and the like), farm animals (e.g., cows, sheep, fowl, pigs, horses, and the like) and laboratory animals (e.g., rats, mice, guinea pigs, and the like).

[0077] The term “cognitive decline” refers to a reduction in one or more cognitive abilities, such as memory, awareness, judgment, and mental acuity, across the adult lifespan. The presence and degree of decline vary with the cognitive ability being measured, as fluid abilities often show greater declines than crystallized. Cognitive decline is a part of normal healthy aging, but a severe decline is not normative and could be symptomatic of disease.Cognitive decline is the primary symptom induced dementias, such as Alzheimer’s disease.

[0078] The term “memory deficits” refers to unusual forgetfulness or memory impairment where a subject may not be able to remember new events or facts, recall one or more memories of the past, or both. The memory deficits can be either short-term and then resolve (transient) or they may be permanent, and depending on the cause, they can get worse over time.

[0079] The term “β-amyloid mediated neurological pathogenesis” refers to the origination and development of neurological conditions, diseases, or disorders that are caused by the aggregation and / or accumulation of β-amyloid peptides.

[0080] Tauopathy is a general term for a group of neurodegenerative diseases showing, as a pathological image of the brain, neurofibrillary changes accompanied by abnormal lesions of tau protein, and Alzheimer’s disease (hereinafter sometimes referred to as “AD”), progressive supranuclear palsy (hereinafter sometimes referred to as “PSP”), corticobasal degeneration (hereinafter sometimes referred to as “CBD”), multiple system atrophy (hereinafter sometimes referred to as “MSA”), pick disease (hereinafter sometimes referred to as “PiD”), and the like are known.

[0081] The phrase “being affected with tauopathy or a dementia-related disease”, that is, “being a patient with tauopathy or a dementia-related disease” refers to a condition that can be diagnosed as having developed tauopathy or a dementia-related disease by clinical diagnosis based on memory and cognitive dysfunction or image diagnosis based on brain atrophy, accumulation of tau protein, and the like.

[0082] The phrase “with tauopathy or a dementia-related disease” refers to a condition diagnosed as having developed tauopathy or a dementia-related disease based on each clinical diagnosis standard for tauopathy and dementia-related diseases, for example, the clinical diagnosis standard of National Institute of Neurological Disorders and Stroke and Society for PSP (NINDS-SPSP), or the like.

[0083] The severity can be evaluated using Mini Mental State Examination (MMSE), which measures the degree of cognitive dysfunction, Functional Assessment Staging (FAST) of dementia that determines the severity mainly based on activities of daily living, Clinical Dementia Rating (CDR) that clinically determines the severity, as well as Severe Impairment Battery (SIB) and modified Rankin Scale (mRS) used in clinical test, and the like.

[0084] The phrase the “people at risk and dementia-related diseases”, that is, “a person who may be affected with tauopathy and dementia-related diseases (human)”, “one (human) in high risk group of tauopathy and dementia-related diseases” include humans in a state where abnormal accumulation of tau protein in the brain tissue has started, and tauopathy or a dementia-related disease is highly likely developed in the near future, that is, a state in which tau protein is accumulated in brain tissue, even though the onset of the disease cannot be diagnosed according to the aforementioned diagnosis. Here, the accumulation of tau protein in the brain tissue can be confirmed by Positron Emission Tomography (PET) of tau protein or using tau, phosphorylated tau in the cerebral spinal fluid, and the like as biomarkers.

[0085] The phrase the “tauopathy and dementia-related diseases” specifically refers to at least one disease selected from the group consisting of Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), multiple system atrophy (MSA), pick disease (PiD), frontotemporal dementia (FTD), dementia with Lewy Bodies (DLB), vascular dementia (VaD), senile dementia of the NFT type (SD-NFT), argyrophilic grain dementia (AGD), basophilic inclusion body disease (BIBD), Neuronal intermediate filament inclusion disease (NIFID), multiple sclerosis (MS), cognitive dysfunction associated with Parkinson’s disease (PDD), cognitive dysfunction associated with amyotrophic lateral sclerosis (ALS), cognitive dysfunction associated with Huntington’s disease (HD), and cognitive dysfunction associated with spinocerebella degeneration (SCD).

[0086] Embodiments described herein relate to compositions and methods of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder. We found that diminution of brain NAD+homeostasis (or NAD+ / NADH redox state) in neurodegenerative disorders, such as Alzheimer’s disease (AD) and / or other tauopathies, can drive the loss of brain resilience that gives way to secondary pathologic events. We further found that these events, as well as neuropsychiatric and cognitive impairment, are prevented and reversed when brain NAD+homeostasis (or NAD+ / NADH redox state) is normalized. Notably, we show that pharmacologically preserving NAD+homeostasis (or NAD+ / NADH redox state), without abnormally elevating, brain NAD+levels in presymptomatic amyloid pathology-driven mice prevents plaque accumulation, tau phosphorylation, blood-brain barrier deterioration, oxidative stress, DNA damage, neuroinflammation, impaired hippocampal neurogenesis,deficient synaptic plasticity, and neuropsychiatric and cognitive impairment. Furthermore, delaying treatment until mice are fully symptomatic reverses most features and restores normal behavior and cognition in both amyloid pathology-driven and tau pathology-driven models, without mitigating genetically driven amyloid or tau pathology. Normalizing NAD+homeostasis (or NAD+ / NADH redox state) also prevents oxidative damage and mitochondrial dysfunction in oxidatively stressed human brain microvascular endothelial cells. Our results offer a first proof of principle for reversing brain pathology and restoring cognition in neurodegenerative disorders, such as AD.

[0087] In some embodiments, a method of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder can include administering to the subject an amount of an aminopropyl carbazole compound effective to normalize NAD+homeostasis (or NAD+ / NADH redox state)in the subject’s brain without abnormally elevating brain NAD+levels and restore cognitive and / or behavioral function in the subject.

[0088] In some embodiments, an aminopropyl carbazole compound, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels can include a compound having formula (I) (e.g., P7C3 or derivatives thereof). A compound having the formula (I) includes: a pharmaceutically acceptable salt thereof,each of R1, R2, R4, R5, R7, and R8is independently selected from hydrogen, halo, hydroxyl, sulfhydryl, C1-C6 alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, C2-C6alkynyl, cyclopropyl, -N3, cyano, -NH2, - NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)( C1-C6 alkyl), and nitro;each of R3and R6is selected from fluoro, bromo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6 haloalkyl, C1-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, -NH(C1-C6 alkyl), - N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and nitro; each of L1and L2is, independently, C1-C3 alkylene, which is optionally substituted with from 1-2 independently selected Rc; A is: (i) CRA1RA2, wherein one of RA1and RA2is halo or OR9, wherein R9is hydrogen or C1-C3 alkyl that is optionally substituted with hydroxyl or C1-C3 alkoxy; and the other of RA1and RA2is hydrogen, halo, or C1-C3 alkyl; or (ii) C=O; Z is: -NR10R11; or -OR12; or -S(O)nR13, wherein n is 1, or 2; each of R10and R11is independently selected from: (a) hydrogen; (b) C6-C10aryl that is optionally substituted with from 1-4 Rb; (c) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; (d) C1-C6 alkyl or C1-C6 haloalkyl, each of which is optionally substituted with from 1-3 Rd; (e) -C(O)(C1-C6 alkyl), -C(O)(C1-C6 haloalkyl), or -C(O)O(C1-C6 alkyl); or (f) C2-C6alkenyl or C2-C6alkynyl; wherein one of R10and R11is selected from (b) or (c) and the other of R10and R11is selected from (a), (d), (e), or (f); R12is: (i) C6-C10 aryl that is optionally substituted with from 1-4 Rb; or (ii) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; R13is: C6-C10aryl that is optionally substituted with from 1-4 Rb; Rbat each occurrence is independently selected from the substituents delineated in (aa) through (dd) below:(aa) C1-C6 haloalkoxy; C1- C1-C6 thiohaloalkoxy; -O-(CH2)1-3- [O(CH2)1-3]1-3-H; -NH(C1-C6alkyl), -N(C1-C6alkyl)2, wherein the alkyl portion of each is unsubstituted or substituted with from 1-3 independently selected Re; (bb) hydroxyl; cyano; -NH2; azido; sulfhydryl; C2-C6alkenyl; C2-C6alkynyl; -C(O)H; -C(O)(C1-C6 alkyl); -C(O)(C1-C6 haloalkyl); -C(O)O(C1-C6 alkyl); -C(O)NH2; -C(O)NH(C1-C6alkyl);-C(O)N(C1-C6alkyl)2; -SO2(C1-C6alkyl); -SO2NH2; -SO2NH(C1-C6alkyl); -SO2N(C1-C6 alkyl)2; (cc) C3-C6cycloalkyl or heterocyclyl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heterocyclyl is independently selected from N, NH, N(C1- C6 alkyl), NC(O)(C1-C6 alkyl), 0, and S; and (dd) phenyl or heteroaryl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heteroaryl is independently selected from N, NH, N(C1-C3 alkyl), O, and S; wherein each of said phenyl and heteroaryl is optionally substituted with from 1-3 substituents independently selected from halo; hydroxyl; cyano; nitro; -NH2; -NH(C1-C6 alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), C1-C6alkoxy; C1-C6haloalkoxy; C1-C6thioalkoxy; C1-C6 thiohaloalkoxy; C1-C6 alkyl, and C1-C6 haloalkyl; Rcat each occurrence is, independently selected from halo, C1-C6alkoxy, C1- C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, -NH2, - NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and cyano; Rdat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, - NH2, NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and cyano; and Reat each occurrence is, independently selected from hydroxyl, C1-C6alkoxy; C1-C6 thioalkoxy; C1-C6 haloalkoxy; C1-C6 thiohaloalkoxy; -NH2; -NH(C1-C6 alkyl); -N(C1- C6 alkyl)2; -NHC(O)( C1-C6 alkyl); cyano; -C(O)H; -C(O)(C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)OH; -C(O)O(C1-C6alkyl); -C(O)NH2; -C(O)NH(C1-C6alkyl); -C(O)N(C1- C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6 alkyl)2; and L3- (C1-C6alkylene)-biotin, wherein L3is a -O-, -NH-, -NCH3-, -C(O)-, -C(O)NH-, -C(O)NCH3-, - NHC(O)-, or -NCH3C(O)-.

[0089] In some embodiments, an aminopropyl carbazole compound having formula (I) can be selected from: 1-(3,6-Dibromo-9H-carbazol-9-yl)-3-(3-methoxyphenylamino)-propan-2-ol;S-1-(3,6-Dibromo-9H- 9-yl)-3-(3-methoxyphenylamino)-propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(phenylthio)propan-2-ol; N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2-hydroxypropyl)-N-(3- methoxyphenyl)acetamide; N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2-fluoropropyl)-3-methoxyaniline; N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2-methoxypropyl)-3-methoxyaniline; 1-(3,6-Dimethyl-9H-carbazol-9-yl)-3-(3-methoxyphenylamino)propan-2-ol; 1-(3-Bromo-6-methyl-9H-carbazol-9-yl)-3-(3-methoxyphenylamino)-propan- 2-ol; 1-(3,6-Dichloro-9H-carbazol-9-yl)-3-(3-methoxyphenylamino)propan-2-ol; 1-(3,6-Dibromo-9H-pyrido[3,4-b]indol-9-yl)-3-(phenylamino)propan-2-ol; 1-(3-Azidophenylamino)-3-(3,6-dibromo-9H-carbazol-9-yl)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(pyridin-2-ylamino)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-((3-methoxyphenyl)(methyl)- amino)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(pyrimidin-2-ylamino)propan-2-ol; 3,6-dibromo-3-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(3-ethoxyphenylamino)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(phenylsulfinyl)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(phenylsulfonyl)propan-2-ol; 1-(3-bromo-9H-carbazol-9-yl)-3-(3-methoxyphenylamino)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-phenoxypropan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(pyridin-3-ylamino)propan-2-ol; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(pyridin-4-ylamino)propan-2-ol; N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2,2-difluoropropyl)-3-methoxyaniline; 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(naphthalen-1-ylamino)propan-2-ol; or a pharmaceutically acceptable salt thereof.

[0090] In still other embodiments, the aminopropyl carbazole compound having formula (I) can be an aminopropyl carbazole compound having the formula (II):a pharmaceutically acceptable salt

[0091] to as 3,6-dibromo-3-fluoro-N-(3- methoxyphenyl)-9H-carbazole-9-propanamine (P7C3-A20).

[0092] It will be appreciated that the aminopropyl carbazole compound having formula (I) can also include any number of aminopropyl carbazole compounds disclosed in U.S. Pat. No.8,362,277; U.S. Publication No.2011 / 0015217; U.S. Publication No.2012 / 0022096; U.S. Publication No.2013 / 0040977; and U.S. application Ser. No.14 / 339,772 filed July, 24, 2014, all of which are hereby incorporated herein by reference in their entirety, in particular the compounds disclosed in the Examples section.

[0093] The compounds of the presently disclosed embodiments may contain one or more asymmetric centers and thus occur as racemates and racemic mixtures, enantiomerically enriched mixtures, single enantiomers, individual diastereomers, and diastereomeric mixtures. All such isomeric forms of these compounds are expressly included in the presently disclosed embodiments. The compounds of the presently disclosed embodiments may also contain linkages (e.g., carbon-carbon bonds, carbon-nitrogen bonds such as amide bonds) wherein bond rotation is restricted about that particular linkage, e.g., restriction resulting from the presence of a ring or double bond. Accordingly, all cis / trans and E / Z isomers and rotational isomers are expressly included in the presently disclosed embodiments. The compounds of the presently disclosed embodiments may also be represented in multiple tautomeric forms; in such instances, the presently disclosed embodiments expressly include all tautomeric forms of the compounds described herein, even though only a single tautomeric form may be represented. All such isomeric forms of such compounds are expressly included in the presently disclosed embodiments.

[0094] Optical isomers can be obtained in pure form by standard procedures known to those skilled in the art, and include, but are not limited to, diastereomeric salt formation,kinetic resolution, and asymmetric for example, Jacques, et al., Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen, S. H., et al., Tetrahedron 33:2725 (1977); Eliel, E. L. Stereochemistry of Carbon Compounds (McGraw- Hill, NY, 1962); Wilen, S. H. Tables of Resolving Agents and Optical Resolutions p.268 (E. L. Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, Ind.1972), each of which is incorporated herein by reference in their entireties. It is also understood that the presently disclosed embodiments encompass all possible regioisomers, and mixtures thereof, which can be obtained in pure form by standard separation procedures known to those skilled in the art, and include, but are not limited to, column chromatography, thin-layer chromatography, and high-performance liquid chromatography.

[0095] The compounds of the presently disclosed embodiments include the compounds themselves, as well as their salts and their prodrugs, if applicable. A salt, for example, can be formed between an anion and a positively charged substituent (e.g., amino) on a compound described herein. Suitable anions include chloride, bromide, iodide, sulfate, nitrate, phosphate, citrate, methanesulfonate, trifluoroacetate, and acetate. Likewise, a salt can also be formed between a cation and a negatively charged substituent (e.g., carboxylate) on a compound described herein. Suitable cations include sodium ion, potassium ion, magnesium ion, calcium ion, and an ammonium cation such as tetramethylammonium ion. Examples of prodrugs include C1-6alkyl esters of carboxylic acid groups, which, upon administration to a subject, are capable of providing active compounds.

[0096] Pharmaceutically acceptable salts of the compounds of the presently disclosed embodiments include those derived from pharmaceutically acceptable inorganic and organic acids and bases. As used herein, the term “pharmaceutically acceptable salt” refers to a salt formed by the addition of a pharmaceutically acceptable acid or base to a compound disclosed herein. As used herein, the phrase “pharmaceutically acceptable” refers to a substance that is acceptable for use in pharmaceutical applications from a toxicological perspective and does not adversely interact with the active ingredient.

[0097] Examples of suitable acid salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptanoate, glycolate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2- hydroxyethanesulfonate, lactate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, salicylate, succinate, sulfate, tartrate, thiocyanate, tosylate and undecanoate. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the presently disclosed embodiments and their pharmaceutically acceptable acid addition salts. Salts derived from appropriate bases include alkali metal (e.g., sodium), alkaline earth metal (e.g., magnesium), ammonium, and N-(alkyl) 4+salts. The presently disclosed embodiments also envision the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersible products may be obtained by such quaternization. Salt forms of the compounds of any of the formulae herein can be amino acid salts of carboxyl groups (e.g., L-arginine, -lysine, -histidine salts).

[0098] Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p.1418; Journal of Pharmaceutical Science, 66, 2 (1977); and “Pharmaceutical Salts: Properties, Selection, and Use A Handbook; Wermuth, C. G. and Stahl, P. H. (eds.) Verlag Helvetica Chimica Acta, Zurich, 2002 [ISBN 3-906390-26-8] each of which is incorporated herein by reference in their entireties.

[0099] The neutral forms of the compounds may be regenerated by contacting the salt with a base or acid and isolating the parent compound in the conventional manner. The parent form of the compound differs from the various salt forms in certain physical properties, such as solubility in polar solvents, but otherwise the salts are equivalent to the parent form of the compound for the purposes of the presently disclosed embodiments.

[0100] In addition to salt forms, the presently disclosed embodiments provide compounds which are in a prodrug form. Prodrugs of the compounds described herein are those compounds that undergo chemical changes under physiological conditions to provide the compounds of the presently disclosed embodiments. Additionally, prodrugs can be converted to the compounds of the presently disclosed embodiments by chemical or biochemical methods in an ex vivo environment. For example, prodrugs can be slowly converted to the compounds of the presently disclosed embodiments when placed in a transdermal patch reservoir with a suitable enzyme or chemical reagent. Prodrugs are often useful because, in some situations, they may be easier to administer than the parent drug.They may, for instance, be more oral administration than the parent drug. The prodrug may also have improved solubility in pharmacological compositions over the parent drug. A wide variety of prodrug derivatives are known in the art, such as those that rely on hydrolytic cleavage or oxidative activation of the prodrug. An example, without limitation, of a prodrug would be a compound of the presently disclosed embodiments which is administered as an ester (the “prodrug”), but then is metabolically hydrolyzed to the carboxylic acid, the active entity. Additional examples include peptidyl derivatives of a compound of the presently disclosed embodiments.

[0101] The presently disclosed embodiments also include various hydrate and solvate forms of the compounds.

[0102] The compounds of the presently disclosed embodiments may also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may be radiolabeled with radioactive isotopes, such as for example tritium (3H), iodine-125 (125I), or carbon-14 (14C). All isotopic variations of the compounds of the presently disclosed embodiments, whether radioactive or not, are intended to be encompassed within the scope of the presently disclosed embodiments.

[0103] In some embodiments, an aminopropyl carbazole compound or pharmaceutically acceptable salt thereof, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels, can restore cognitive function and / or behavioral function in a subject who has a decline in brain NAD+homeostasis (or NAD+ / NADH redox state) associated with a decreasing or decreased NAD+level and an increasing or increased NADH level. The decline in brain NAD+homeostasis (or NAD+ / NADH redox state) can be measured or determined prior to and / or following administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof by, for example, using a magnetic resonance (MR)-based quantification approach. By way of example, an MR-based quantification approach using a high-field MR scanner to obtain endogenous31P MR signals of NAD in animal brains is described in Zhu et al. (2015) Proc. Natl. Acad. Sci. USA 112, 2876–2881, which is herein incorporated by reference in its entirety.

[0104] In some embodiments, the decline in brain NAD+ / NADH redox state or ratio is at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at leastabout 55%, at least about 60%, at least at least about 70%, or at least about 75% compared to control normal or healthy subject.

[0105] For example, a control normal or healthy subject can have an NAD+ / NADH redox state or ratio of about 4.0 measured using an MR-based quantification approach, and a subject having a decline in brain NAD+ / NADH redox state or ratio associated with decreased NAD+level and increased NADH level can have an NAD+ / NADH redox state or ratio of about 3.6, about 3.5, about 3.4, about 3.3, about 3.2, about 3.1, about 3.0, about 2.9, about 2.8, about 2.7, about 2.6, about 2.5, about 2.4, about 2.3, about 2.2, about 2.1, about 2.0, about 1.9, about 1.8, about 1.7, about 1.6, about 1.5, about 1.4, about 1.3, about 1.2, about 1.1, about 1.1, or lower.

[0106] In some embodiments, the amount of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof administered is an amount effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) without abnormally elevating NAD+levels.

[0107] In some embodiments, a therapeutically effective amount of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof administered to the subject is an amount effective to increase or normalize the NAD+ / NADH redox state or ratio in the subject’s brain by at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30% at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75% or more.

[0108] In some embodiments, an aminopropyl carbazole compound or pharmaceutically acceptable salt, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels, can restore cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder selected from subarachnoid hemorrhage, schizophrenia, major depression, bipolar disorder, epilepsy, traumatic brain injury and / or a visual symptom associated therewith, post-traumatic stress disorder, Parkinson’s disease, Parkinson Plus syndromes, Lewy Body Dementia, multiple system atrophy, corticobasal neurodegeneration, progressive supranuclear palsy, AD, AD related dementias, Down syndrome, spinocerebellar ataxia, amyotrophic lateral sclerosis, Huntington’s disease, stroke, brain radiation therapy, chronic stress, abuse of a neuro-activedrug, retinal degeneration, spinal cord nerve injury, idiopathic peripheral neuropathy, cognitive decline and / or general frailty associated with normal aging and / or chemotherapy, chemotherapy induced neuropathy, concussive injury, peripheral nerve crush injury, peripheral neuropathy, diabetic neuropathy, post-traumatic headache, multiple sclerosis, retinal degeneration and dystrophy, Leber congenital amaurosis, retinitis pigmentosa, cone-rod dystrophy, microphthalmia, anophthalmia, myopia, and hyperopia, spinal cord injury, traumatic spinal cord injury, peripheral nerve injury, retinal neuronal death related diseases, retinal trauma, Autism, Stargardt disease, Kearns-Sayre syndrome, Pure neurosensory deafness, Hereditary hearing loss with retinal diseases, Hereditary hearing loss with system atrophies of the nervous system, Progressive spinal muscular atrophy, Progressive bulbar palsy, Primary lateral sclerosis, Hereditary forms of progressive muscular atrophy and spastic paraplegia, Frontotemporal dementia, Dementia with Lewy bodies, Corticobasal degeneration, Progressive supranuclear palsy, Prion disorders causing neurodegeneration, Multiple system atrophy, Hereditary spastic paraparesis, Friedreich ataxia, Non-Friedreich ataxia, Spinocerebellar atrophies, Amyloidoses, Metabolic-related neurodegenerative disorders, Toxin-related neurodegenerative disorders, Multiple sclerosis, Charcot Marie Tooth, Diabetic neuropathy, Metabolic neuropathies, Endocrine neuropathies, Creutzfeldt-Jacob Disease, Primary progressive aphasia, tauopathy, Frontotemporal Lobar Degeneration, Cortical blindness, Shy-Drager Syndrome, Diffuse cerebral cortical atrophy of non-Alzheimer type, Lewy-body dementia, Pick disease, Thalamic degeneration, Mesolimbocortical dementia of non-Alzheimer type, Nonhuntingtonian types of chorea and dementia, Cortical-striatal-spinal degeneration, Dementia-Parkinson-amyotrophic lateral sclerosis complex, Cerebrocerebellar degeneration, Cortico-basal ganglionic degeneration, Familial dementia with spastic paraparesis or myoclonus, Tourette syndrome, or viral infection.

[0109] In some embodiments, the neurodegenerative disorder is a tauopathy.

[0110] In some embodiments, the subject has been identified as having at least one of AD, Lewy body dementia, Vascular dementia, Age-related dementia, Frontotemporal dementia, or mixed dementia.

[0111] In some embodiments, the neurodegenerative disorder is AD.

[0112] In other embodiments, the neurodegenerative disorder is not AD.

[0113] In some embodiments, the of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder includes measuring brain NAD+homeostasis (or NAD+ / NADH redox state or ratio) prior to and / or following administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof and comparing the measured NAD+ / NADH redox state or ratio to a control or control value. A decrease in brain NAD+ / NADH redox state or ratio compared to the control is indicative of the severity of the neurodegenerative disorder, and an increase in NAD+ / NADH redox state or ratio following administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof is indicative of the efficacy of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof in treating cognitive or behavioral deficit. The control can be, for example, the brain NAD+ / NADH redox state of a normal healthy subject of similar age to the subject and / or the brain NAD+ / NADH redox state of a subject prior to administration of the aminopropyl carbazole compound.

[0114] In some embodiments, the cognitive decline and behavioral deficit are associated with a decrease in the brain NAD+ / NADH redox state or ratio of at least about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 110%, about 120%, about 130%, about 140%, about 150%, about 160%, about 170%, about 180%, about 190%, about 200%, about 250%, about 300%, about 350%, about 400%, about 450%, about 500%, about 600%, about 700%, about 800%, about 900%, or about 1000% relative to normal or healthy brain. In certain embodiments, administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof can be used to increase the brain NAD+ / NADH redox state or ratio of the subject from about 5% to about 200%, about 5% to about 180%, about 5% to about 160%, about 5% to about 140%, about 5% to about 120%, about 5% to about 100%, about 5% to about 80%, about 5% to about 60%, about 5% to about 40%, about 10% to about 200%, about 10% to about 180%, about 10% to about 160%, about 10% to about 140%, about 10% to about 120%, about 10% to about 100%, about 10% to about 80%, about 10% to about 60%, about 30% to about 200%, about 30% to about 180%, about 30% to about 160%, about 30% to about 140%, about 30% to about 120%, about 30% to about 100%, about 30% to about 80%, about 40% to about 200%, about 40% to about 180%, about 40% to about 160%, about 40% to about 140%, about 40% to about 120%, about 40% to about 100%,about 50% to about 200%, about 50% to 180%, about 50% to about 160%, about 50% to about 140%, about 50% to about 120%, about 60% to about 200%, about 60% to about 180%, about 60% to about 160%, about 60% to about 140%, about 70% to about 200%, about 70% to about 180%, about 70% to about 160%, about 80% to about 200%, about 80% to about 180%, or about 80% to about 200%.

[0115] In other embodiments, an aminopropyl carbazole compound or pharmaceutically acceptable salt thereof, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels, can be used in a method of treating a subject with a tauopathy or a dementia-related disease. The method can include administering the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof to the subject having the tauopathy or a dementia-related disease at an amount effective to normalize NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels, prevent cognitive and / or behavioral deficits, and / or restore cognitive and / or behavioral function of the subject.

[0116] In some embodiments, the tauopathy treated with the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof is selected from AD, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), Parkinson's discase, Pick's disease (PiD), primary progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler-Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle-predominant dementia, ganglioglioma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT).

[0117] In some embodiments, the tauopathy is associated with a decrease in the brain NAD+ / NADH redox state or ratio of at least about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 110%, about 120%, about 130%, about 140%, about 150%, about 160%, about 170%, about 180%, about 190%, about 200%, about 250%, about 300%, about 350%, about 400%, about 450%, about 500%, about 600%, about 700%, about 800%, about 900%, or about 1000% relative to normal or healthy brain tissue. In certain embodiments, administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof can be used to increase the brain NAD+ / NADH redox state or ratio of the subject from about 5% to about 200%, about 5% to about 180%, about 5% to about 160%, about 5% to about 140%, about 5% to about 120%, about 5% to about 100%, about 5% to about 80%, about 5% to about 60%, about 5% to about 40%, about 10% to about 200%, about 10% to about 180%, about 10% to about 160%, about 10% to about 140%, about 10% to about 120%, about 10% to about 100%, about 10% to about 80%, about 10% to about 60%, about 30% to about 200%, about 30% to about 180%, about 30% to about 160%, about 30% to about 140%, about 30% to about 120%, about 30% to about 100%, about 30% to about 80%, about 40% to about 200%, about 40% to about 180%, about 40% to about 160%, about 40% to about 140%, about 40% to about 120%, about 40% to about 100%, about 50% to about 200%, about 50% to about 180%, about 50% to about 160%, about 50% to about 140%, about 50% to about 120%, about 60% to about 200%, about 60% to about 180%, about 60% to about 160%, about 60% to about 140%, about 70% to about 200%, about 70% to about 180%, about 70% to about 160%, about 80% to about 200%, about 80% to about 180%, or about 80% to about 200%.

[0118] In some embodiments, the decline in cognitive function and / or behavioral function and / or tauopathy associated with a decrease or decline in brain NAD+homeostasis (or NAD+ / NADH redox state) is also associated with differentially expressed proteins that can be normalized by restoration of NAD+homeostasis (or NAD+ / NADH redox state). Proteins that are upregulated in subjects, which have a decrease or decline in NAD+ / NADH redox state or homeostasis, decline in cognitive function and / or behavioral function and / or atauopathy, include BUB3 mitotic (BUB3), DExH-box helicase 9 (DHX9), potassium channel tetramerization domain containing 12 (KCTD12), serine / threonine-protein kinase PAK 2 (PAK2), PEST proteolytic signal containing nuclear protein (PCNP), protein tyrosine kinase 2 beta (PTK2B), and ribosomal protein L7a (RPL7A). Proteins that are downregulated in subjects, which have a decrease or decline in NAD+ / NADH redox state or homeostasis, decline in cognitive function and / or behavioral function and / or a tauopathy, include RAN binding protein 1 (RANBP1), amphiphysin (AMPH), ankyrin-3 (ANK3, also known as ankyrinG), contactin-associated protein 1 (CNTNAP1), cytochrome C oxidase subunit B1 (COX6B1), GDNF family receptor alpha 2 (GFRA2), leucyl-tRNA synthetase 2, mitochondrial (LARS2), Ras like without CAAX 2 (RIT2), secretory carrier membrane protein 5 (SCAMP5), and synaptosome associated protein 91 (SNAP91).

[0119] By way of example, a decrease or decline in brain NAD+homeostasis (or NAD+ / NADH redox state), a decline in cognitive function and / or behavioral function and / or tauopathy can be associated with an increase in the expression of at least one BUB3, DHX9, KCTD12, PAK2, PCNP, PTK2B, or RPL7A of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 100%, or more in brain tissue of the subject relative to a normal or healthy subject and / or a decrease in the expression of at least one RANBP1, AMPH, ANK3, CNTNAP1, COX6B1, GFRA2, LARS2, RIT2, SCAMP5, and SNAP91 of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 100%, or more in brain tissue of the subject relative to a normal or healthy subject.

[0120] In some embodiments, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof described herein can be administered to a subject with a decline in cognitive function and / or behavioral function and / or tauopathy at an amount effective normalize brain NAD+ / NADH redox state or homeostasis and decrease expression of at least one BUB3, DHX9, KCTD12, PAK2, PCNP, PTK2B, or RPL7A at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%,about 85%, about 90%, about 95%, about or more in brain tissue of the subject, and / or increase expression of at least one RANBP1, AMPH, ANK3, CNTNAP1, COX6B1, GFRA2, LARS2, RIT2, SCAMP5, and SNAP91 at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 100%, or more in brain tissue of the subject.

[0121] In other embodiments, an aminopropyl carbazole compound or pharmaceutically acceptable salt thereof, which normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating brain NAD+levels, can be used in a method of inhibiting and / or reducing β-amyloid plaque accumulation and / or Tau phosphorylation in a subject in need thereof. The method includes administering to the subject an amount of an aminopropyl carbazole compound effective to normalize NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+levels and reduce β-amyloid plaque accumulation and / or Tau phosphorylation in the subject.

[0122] In some embodiments, the subject has or is at increased risk of a tauopathy, such as AD, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), Parkinson's discase, Pick's disease (PiD), primary progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler- Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle-predominant dementia, ganglioglioma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT). In other embodiments, the tauopathy is not Alzheimer’s disease.

[0123] While it may be possible to administer the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof, such as a compound of formula (I) (and / or a compound of any of the other formulae described herein) alone to a subject to restore cognitive function and / or behavioral function, treat a neurodegenative disorder, such as a tauopathy, and / or inhibit and / or reduce β-amyloid plaque accumulation and / or Tau phosphorylation in a subject in need thereof, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof normally will be present as an active ingredient in a pharmaceutical composition along with a pharmaceutically acceptable carrier and / or one or more additional therapeutic agents. Additional therapeutics may include, but are not limited to, antidepressant medications (including selective serotonin reuptake inhibitors, tricyclic antidepressants, monoamine oxidase inhibitors, and other antidepressant medications including but not limited to venlafaxine, nefazadone, bupropion, mirtazapine, lithium and trazodone) and acetylcholinesterase inhibitors (including but not limited to Aricept, Reminyl, and Exelon).

[0124] The term “pharmaceutically acceptable carrier” refers to a carrier or adjuvant that may be administered to a subject (e.g., a patient), together with a compound of the presently disclosed embodiments, and which does not destroy the pharmacological activity thereof and is nontoxic when administered in doses sufficient to deliver a therapeutic amount of the compound.

[0125] Pharmaceutically acceptable carriers, adjuvants and vehicles that may be used in the compositions of the presently disclosed embodiments include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, self-emulsifying drug delivery systems (SEDDS) such as d-α-tocopherol polyethyleneglycol 1000 succinate, surfactants used in pharmaceutical dosage forms such as Tweens or other similar polymeric delivery matrices, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts, or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodiumcarboxymethylcellulose, polyacrylates, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat. Cyclodextrins such as α-, β-, and γ-cyclodextrin, or chemically modified derivatives such as hydroxyalkylcyclodextrins, including 2- and 3- hydroxypropyl-β-cyclodextrins, or other solubilized derivatives may also be advantageously used to enhance delivery of compounds of the formulae described herein.

[0126] The compositions for administration can take the form of bulk liquid solutions or suspensions, or bulk powders. More commonly, however, the compositions are presented in unit dosage forms to facilitate accurate dosing. The term “unit dosage forms” refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient. Typical unit dosage forms include prefilled, premeasured ampules or syringes of the liquid compositions or pills, tablets, capsules, lozenges, or the like in the case of solid compositions. In such compositions, the compound is usually a minor component (from about 0.1 to about 50% by weight or preferably from about 1 to about 40% by weight) with the remainder being various vehicles or carriers and processing aids helpful for forming the desired dosing form.

[0127] The route(s) of administration will be readily apparent to the skilled artisan and will depend upon any number of factors, including the type and severity of the disease being treated, the type and age of the veterinary or human patient being treated, and the like.

[0128] The formulations of the pharmaceutical compositions described herein may be prepared by any method known or hereafter developed in the art of pharmacology and pharmaceutics. In general, such preparatory methods include the step of bringing the active ingredient into association with a carrier or one or more other accessory ingredients, and then, if necessary or desirable, shaping or packaging the product into a desired single-dose or multi-dose unit.

[0129] Although the descriptions of pharmaceutical compositions provided herein are principally directed to pharmaceutical compositions, which are suitable for ethical administration to humans, it will be understood by the skilled artisan that such compositions are generally suitable for administration to animals of all sorts. Modification of pharmaceutical compositions suitable for administration to humans in order to render the compositions suitable for administration to various animals is well understood, and the ordinarily skilled veterinary pharmacologist can design and perform such modification withmerely ordinary, if any, experimentation. to which administration of the pharmaceutical compositions is contemplated include, but are not limited to, humans and other primates, mammals, including commercially relevant mammals such as cattle, pigs, horses, sheep, cats, and dogs.

[0130] In some embodiments, the concentration of the aminopropyl carbazole compound or a pharmaceutically acceptable salt described herein, administered to the subject can be any useful concentration, and in particular, a concentration effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) without abnormally elevating NAD+level in the subject. For example, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof may be administered to the subject at a concentration of about 0.5 nanomolar (nM), about 1 nM, about 10 nM, about 20 nM, about 30 nM, about 40 nM, about 50 nM, about 60 nM, about 70 nM, about 80 nM, about 90 nM, about 100 nM, about 200 nM, about 300 nM, about 400 nM, about 500 nM, about 600 nM, about 700 nM, about 800 nM, about 900 nM, about 1 micromolar (μM), about 2 μM, about 3 μM, about 4 μM, about 5 μM, about 6 μM, about 7 μM, about 8 μM, about 9 μM, about 10 μM.

[0131] In some embodiments, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof may be administered to the subject at a concentration of at least about 0.5 nanomolar (nM), at least about 1 nM, at least about 10 nM, at least about 20 nM, at least about 30 nM, at least about 40 nM, at least about 50 nM, at least about 60 nM, at least about 70 nM, at least about 80 nM, at least about 90 nM, at least about 100 nM, at least about 200 nM, at least about 300 nM, at least about 400 nM, at least about 500 nM, at least about 600 nM, at least about 700 nM, at least about 800 nM, at least about 900 nM, at least about 1 micromolar (μM), at least about 2 μM, at least about 3 μM, at least about 4 μM, at least about 5 μM, at least about 6 μM, at least about 7 μM, at least about 8 μM, at least about 9 μM, at least about 10 μM.

[0132] In some embodiments, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof may be administered to the subject at a concentration of at most about 10 μM, at most about 9 μM, at most about 8 μM, at most about 7 μM, at most about 6 μM, at most about 5 μM, at most about 4 μM, at most about 3 μM, at most about 2 μM, at most about 1 μM, at most about 900 nM, at most about 800 nM, at most about 700 nM, at most about 600 nM, at most about 500 nM, at most about 400 nM, at most about 300 nM, at most about 200 nM, at most about 100 nM, at most about 90 nM, at most about80 nM, at most about 70 nM, at most about nM, at most about 50 nM, at most about 40 nM, at most about 30 nM, at most about 20 nM, at most about 10 nM, at most about 1 nM, at most about 0.5 nM, etc. A range of concentrations may be used, e.g., between 22 nM-1 μM.

[0133] In some embodiments, an effective amount (i.e., dose) of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof described herein to be administered to a subject can be determined depending upon, for example, age, body weight, symptom, the desired therapeutic effect, the route of administration, and the duration of the treatment. Examples of doses can be from about 10 micrograms (μg) to about 1000 mg, by, for example, oral or parenteral administration. Examples of dose ranges can include a dose of at least 10 micrograms (μg), a dose of at least 50 μg, a dose of at least 100 μg, a dose of at least 200 μg, a dose of at least 300 μg, a dose of at least 400 μg, a dose of at least 500 μg, a dose of at least 750 μg, a dose of at least 1 milligram (mg), a dose of at least 1.2 mg, a dose of at least 1.5 mg, a dose of at least 2 mg, a dose of at least 3 mg, a dose of at least 4 mg, a dose of at least 5 mg, a dose of at least 6 mg, a dose of at least 8 mg, a dose of at least 10 mg, a dose of at least 12 mg, a dose of at least 15 mg, a dose of at least 20 mg, a dose of at least 25 mg, a dose of at least 30 mg, a dose of at least 40 mg, a dose of at least 50 mg, a dose of at least 60 mg, a dose of at least 80 mg, a dose of at least 100 mg, a dose of at least 120 mg, a dose of at least 140 mg, a dose of at least 160 mg, a dose of at least 180 mg, a dose of at least 200 mg, a dose of at least 225 mg, a dose of at least mg, a dose of at least 250 mg, a dose of at least 275 mg, a dose of at least 300 mg, a dose of at least 350 mg, a dose of at least 400 mg, a dose of at least 500 mg, a dose of at least 600 mg, a dose of at least 800 mg.

[0134] In some embodiments, the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof described herein can be administered at a dose of at most 800 mg, at a dose of at most 600 mg, at a dose of at most 500 mg, at a dose of at most 400 mg, at a dose of at most 300 mg, at a dose of at most 250 mg, at a dose of at most 225 mg, at a dose of at most 200 mg, at a dose of at most 180 mg, at a dose of at most 160 mg, at a dose of at most 140 mg, at a dose of at most 120 mg, at a dose of at most 100 mg, at a dose of at most 80 mg, at a dose of at most 60 mg, at a dose of at most 50 mg, at a dose of at most 40 mg, at a dose of at most 30 mg, at a dose of at most 25 mg, at a dose of at most 20 mg, at a dose of at most 15 mg, at a dose of at most 12 mg, at a dose of at most 10 mg, at a dose of at most 8 mg, at a dose of at most 6 mg, at a dose of at most 5 mg, at a dose of at most 4 mg, at a dose of at most 3 mg, at a dose of at most 2 mg, at a dose of at most 1.5 mg, at a dose of atmost 1.2 mg, a dose of at most 1 mg, a at most 750 μg, a dose of at most 600 μg, a dose of at most 500 μg, a dose of at most 400 μg, a dose of at most 350 μg, a dose of at most 300 μg, a dose of at most 250 μg, a dose of at most 200 μg, a dose of at most 180 μg, a dose of at most 150 μg, a dose of at most 120 μg, a dose of at most 100 μg, a dose of at most 80 μg, a dose of at most 50 μg, a dose of at most 20 μg, a dose of at most 10 μg.

[0135] Specific examples of particular effective amounts contemplated via oral or parenteral administration can include about 0.02, 0.03, 0.04, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, 450, 455, 460, 465, 470, 475, 480, 485, 490, 495, 500, 505, 510, 515, 520, 525, 530, 535, 540, 545, 550, 555, 560, 565, 570, 575, 580, 585, 590, 595, 600, 605, 610, 615, 620, 625, 630, 635, 640, 645, 650, 655, 660, 665, 670, 675, 680, 685, 690, 695, 700, 705, 710, 715, 720, 725, 730, 735, 740, 745, 750, 755, 760, 765, 770, 775, 780, 785, 790, 795, 800, 805, 810, 820, 825, 830, 835, 840, 845, 850, 855, 860, 865, 870, 875, 880, 885, 890, 895, 900, 905, 910, 915, 920, 925, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, 995, 1000 mg or more. The oral dose can be administered once daily, twice daily, three times daily, or more frequently.

[0136] The dose of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof for use in parenteral administration (e.g., intravenous administration) is generally from about 0.01 to about 300 mg / kg body weight. Examples of dose ranges can include from a minimum dose of about 0.01, 0.10, 0.50, 1, 5, 10, 25, 50, or 100 mg / kg body weight to a maximum dose of about 125, 150, 175, 200, 250, 275, or 300 mg / kg body weight, wherein the dose range can include from any one of the foregoing minimum doses to any one of the foregoing maximum doses.

[0137] In other embodiments, a therapeutically effective dosage amount of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof administeredto the subject may be, for example, about mg / kg weight to 500 mg / kg weight, e.g., from about 0.001 mg / kg weight to 400 mg / kg weight, from about 0.001 mg / kg weight to 300 mg / kg weight, from about 0.001 mg / kg weight to 200 mg / kg weight, from about 0.001 mg / kg weight to 100 mg / kg weight, from about 0.001 mg / kg weight to 90 mg / kg weight, from about 0.001 mg / kg weight to 80 mg / kg weight, from about 0.001 mg / kg weight to 70 mg / kg weight, from about 0.001 mg / kg weight to 60 mg / kg weight, from about 0.001 mg / kg weight to 50 mg / kg weight, from about 0.001 mg / kg weight to 40 mg / kg weight, from about 0.001 mg / kg weight to 30 mg / kg weight, from about 0.001 mg / kg weight to 25 mg / kg weight, from about 0.001 mg / kg weight to 20 mg / kg weight, from about 0.001 mg / kg weight to 15 mg / kg weight, from about 0.001 mg / kg weight to 10 mg / kg weight.

[0138] In still other embodiments, a therapeutically effective dosage amount of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof administered to the subject may be, for example, about 0.0001 mg / kg weight to 0.1 mg / kg weight, e.g., from about 0.0001 mg / kg weight to 0.09 mg / kg weight, from about 0.0001 mg / kg weight to 0.08 mg / kg weight, from about 0.0001 mg / kg weight to 0.07 mg / kg weight, from about 0.0001 mg / kg weight to 0.06 mg / kg weight, from about 0.0001 mg / kg weight to 0.05 mg / kg weight, from about 0.0001 mg / kg weight to about 0.04 mg / kg weight, from about 0.0001 mg / kg weight to 0.03 mg / kg weight, from about 0.0001 mg / kg weight to 0.02 mg / kg weight, from about 0.0001 mg / kg weight to 0.019 mg / kg weight, from about 0.0001 mg / kg weight to 0.018 mg / kg weight, from about 0.0001 mg / kg weight to 0.017 mg / kg weight, from about 0.0001 mg / kg weight to 0.016 mg / kg weight, from about 0.0001 mg / kg weight to 0.015 mg / kg weight, from about 0.0001 mg / kg weight to 0.014 mg / kg weight, from about 0.0001 mg / kg weight to 0.013 mg / kg weight, from about 0.0001 mg / kg weight to 0.012 mg / kg weight, from about 0.0001 mg / kg weight to 0.011 mg / kg weight, from about 0.0001 mg / kg weight to 0.01 mg / kg weight, from about 0.0001 mg / kg weight to 0.009 mg / kg weight, from about 0.0001 mg / kg weight to 0.008 mg / kg weight, from about 0.0001 mg / kg weight to 0.007 mg / kg weight, from about 0.0001 mg / kg weight to 0.006 mg / kg weight, from about 0.0001 mg / kg weight to 0.005 mg / kg weight, from about 0.0001 mg / kg weight to 0.004 mg / kg weight, from about 0.0001 mg / kg weight to 0.003 mg / kg weight, from about 0.0001 mg / kg weight to 0.002 mg / kg weight.

[0139] In some embodiments, the therapeutically effective dose of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof administered to the subjectmay be 0.0001 mg / kg weight, 0.0002 0.0003 mg / kg weight, 0.0004 mg / kg weight, 0.0005 mg / kg weight, 0.0006 mg / kg weight, 0.0007 mg / kg weight, 0.0008 mg / kg weight, 0.0009 mg / kg weight, 0.001 mg / kg weight, 0.002 mg / kg weight, 0.003 mg / kg weight, 0.004 mg / kg weight, 0.005 mg / kg weight, 0.006 mg / kg weight, 0.007 mg / kg weight, 0.008 mg / kg weight, 0.009 mg / kg weight, 0.01 mg / kg weight, 0.02 mg / kg weight, 0.03 mg / kg weight, 0.04 mg / kg weight, 0.05 mg / kg weight, 0.06 mg / kg weight, 0.07 mg / kg weight, 0.08 mg / kg weight, 0.09 mg / kg weight, or 0.1 mg / kg weight. The effective dose for a particular individual can be varied (e.g., increased or decreased) over time, depending on the needs of the individual.

[0140] In some embodiments, a therapeutically effective dosage of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof administered to the subject may be a dosage of 10 μg / kg / day, 50 μg / kg / day, 100 μg / kg / day, 250 μg / kg / day, 500 μg / kg / day, 1000 μg / kg / day or more. In various embodiments, amount of the aminopropyl carbazole compound or a pharmaceutically acceptable salt thereof administered to the subject is sufficient to provide a dosage to a patient of between 0.01 μg / kg and 10 μg / kg; 0.1 μg / kg and 5 μg / kg; 0.1 μg / kg and 1000 μg / kg; 0.1 μg / kg and 900 μg / kg; 0.1 μg / kg and 900 μg / kg; 0.1 μg / kg and 800 μg / kg; 0.1 μg / kg and 700 μg / kg; 0.1 μg / kg and 600 μg / kg; 0.1 μg / kg and 500 μg / kg; or 0.1 μg / kg and 400 μg / kg.

[0141] Continuous intravenous administration is also contemplated for from 1 to 24 hours per day to achieve a target concentration from about 0.01 mg / L blood to about 100 mg / L blood. Examples of dose ranges can include from a minimum dose of about 0.01, 0.10, 0.25, 0.50, 1, 5, 10, or 25 mg / L blood to a maximum dose of about 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 100 mg / L, wherein an exemplary dose ranges can include from any one of the foregoing minimum doses to any one of the foregoing maximum doses. Specific examples of particular effective amounts contemplated via this route include about 0.02, 0.03, 0.04, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 mg / L blood or more. The dose to be used can depend upon various conditions,and there may be cases wherein doses or greater than the ranges specified above are used.

[0142] Actual dosage levels of the active ingredients in the pharmaceutical compositions may be varied so as to obtain an amount of the active ingredient that is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient.

[0143] A medical doctor, e.g., physician or veterinarian, having ordinary skill in the art may readily determine and prescribe the effective amount of the pharmaceutical composition required. For example, the physician or veterinarian could start doses of the compounds employed in the pharmaceutical composition at levels lower than that required in order to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved.

[0144] In another embodiment, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof can be administered for an unlimited time period or chronically to the subject at an amount effective to maintain normalization of NAD+ / NADH redox levels in the subject’s brain without abnormally elevating NAD+levels. Chronic administration of or chronic treatment using the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof refers to an extended and repeated administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof. For example, delivery of multiple or repeated doses of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof over the course of a long-time scale, preferably at least a week, for example, for one year, two years or more. Chronic administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof is generally intended for the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof to have a continued beneficial effect to maintain normalization of NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain after normalization of NAD+homeostasis is achieved so as to prevent or slow deterioration of a disease-state (e.g., neurodegeneration) over time.

[0145] In some embodiments, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof is chronically administered to the subject at a dose of about 0.01 to about 300 mg / kg body weight per day. Examples of dose ranges can include from a minimum dose of about 0.01, 0.10, 0.50, 1, 5, 10, 25, 50, or 100 mg / kg body weight toa maximum dose of about 125, 150, 175, 275, or 300 mg / kg body weight, wherein the dose range can include from any one of the foregoing minimum doses to any one of the foregoing maximum doses. Specific examples of effective amounts contemplated include about 0.02, 0.03, 0.04, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300 mg / kg body weight or more.

[0146] In some embodiments, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof is chronically administered to the subject at a dose of about 0.01 to about 1000 mg per day. Specific examples of particular effective amounts contemplated for chronic administration can include about 0.02, 0.03, 0.04, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, 450, 455, 460, 465, 470, 475, 480, 485, 490, 495, 500, 505, 510, 515, 520, 525, 530, 535, 540, 545, 550, 555, 560, 565, 570, 575, 580, 585, 590, 595, 600, 605, 610, 615, 620, 625, 630, 635, 640, 645, 650, 655, 660, 665, 670, 675, 680, 685, 690, 695, 700, 705, 710, 715, 720, 725, 730, 735, 740, 745, 750, 755, 760, 765, 770, 775, 780, 785, 790, 795, 800, 805, 810, 820, 825, 830, 835, 840, 845, 850, 855, 860, 865, 870, 875, 880, 885, 890, 895, 900, 905, 910, 915, 920, 925, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, 995, 1000 mg or more.

[0147] In another embodiment, the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof can be administered an initial dose, treatment dose, or normalization dose effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) and, after normalization, administered a maintenance dose effective to maintain the normalized brain NAD+homeostasis (or NAD+ / NADH redox state).

[0148] The term “maintenance dose” to a dosage administered to a subject to maintain the desired therapeutic effect, e.g., normalization of brain NAD+homeostasis (or NAD+ / NADH redox state). In some embodiments, a subject's maintenance dose is the same as the dose during the treatment period used to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain. In some embodiments, a subject's maintenance dose is the less than and / or greater than the dose during the treatment period used to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) or homeostasis in the subject’s brain.

[0149] In some embodiments, the frequency of the maintenance dose is every week. In some embodiments, the maintenance dose is every two weeks (bi-weekly). In some embodiments, the maintenance dose is every four weeks (monthly). In some embodiments, the subcutaneous maintenance dose is administered every six weeks. In some embodiments, the subcutaneous maintenance dose is administered every eight weeks (2 months). In some embodiments, the maintenance dose is every three months (every twelve weeks or quarterly). In some embodiments, the maintenance dose is every six months (every 24 weeks or semi- annually). In some embodiments, a subject's maintenance dose is the same as the dose during the treatment period. In some embodiments, the maintenance dose is same dose amount as the dose prior to administering the maintenance dose. In some embodiments, the maintenance dose amount is lower dose than the dose prior to administering the maintenance dose. In some embodiments, the maintenance dose is same dose frequency as the dose prior to administering the maintenance dose. In some embodiments, the maintenance dose is lower dose frequency than the dose prior to administering the maintenance dose.

[0150] In other embodiments, the maintenance dose is administered with a periodic interval of 1 day to 28 days, 7 days to 28 days, 14 days to 28 days, 21 days to 28 days, 3 days to 14 days, 5 days to 14 days, 7 days to 14 days, 9 days to 14 days, 11 days to 14 days, 13 days to 14 days, 2 days to 7 days, 3 days to 7 days, 4 days to 7 days, 5 days to 7 days, or 6 days to 7 days. In some embodiments, the maintenance doses are administered with a periodic interval of 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, or 28 days. In some embodiments, the doses are separated so as to maintain amelioration of the symptom of the disorder.

[0151] In still other embodiments, or before administering the maintenance dose, the method includes measuring brain NAD+ / NADH redox state or ratio and comparing the measured NAD+ / NADH redox state or ratio to a control ratio to determine the concentration or amount of the maintenance dose to be administered. The control can be, for example, the brain NAD+ / NADH redox state or ratio of a normal healthy subject of similar age to the subject and / or the brain NAD+ / NADH redox state or ratio of a subject prior to administration of the aminopropyl carbazole compound or pharmaceutically acceptable salt thereof.

[0152] The invention is further illustrated by the following example, which is not intended to limit the scope of the claims. Example

[0153] Central to cellular resilience is the maintenance of nicotinamide adenine dinucleotide (NAD+) homeostasis, a critical regulator of oxidative stress mitigation, DNA repair, neuroinflammation, blood-brain barrier (BBB) integrity, postnatal hippocampal neurogenesis, synaptic plasticity, and neuronal survival. Previous preclinical studies have reported NAD+depletion in AD models, with NAD+precursor supplementation showing partial prevention of pathology. However, such approaches risk supraphysiologic NAD+elevation, which promotes cancer cell growth and metastasis. Maintaining normal NAD+homeostasis is essential for preventing adverse physiologic effects, and the relationship between NAD+homeostasis, disease severity, and therapeutic reversibility remains unexplored in advanced AD.

[0154] In this Example, we show that pharmacologic restoration of NAD+homeostasis via P7C3-A20, a neuroprotective compound that normalizes NAD+homeostasis without exceeding physiologic levels, reverses cognitive deficits and neuropathology in advanced Aβ- and tau-driven AD models. Our multi-omics analyses reveal conserved molecular signatures between human and mouse AD, including dysregulated NAD+homeostasis that correlates with pathologic and cognitive severity. Furthermore, we show that NDAN individuals exhibit transcriptional profiles favoring NAD+homeostasis, while P7C3-A20 rescues NAD+homeostasis and prevents oxidative damage and mitochondrial dysfunction in oxidatively-stressed human brain microvascular endothelial cells (HBMVECs), a model of BBB deterioration in AD. We provide the first evidence of full cognitive recovery and broadpathologic reversal, associated with NAD+restoration, in advanced AD models. We also identified 46 conserved protein-level alterations in human and mouse AD brain that are corrected in AD mice by treatment with P7C3-A20, alongside transcriptomic overlaps in human AD, pinpointing potential novel mechanisms and therapeutic targets of AD reversal in humans. Taken together, our findings redefine AD as a reversible condition mediated by dynamic secondary processes rather than fixed neuronal loss, offering a framework for pursuing therapies aimed at restoring brain resilience to achieve clinical recovery from AD and related forms of dementia. Materials and Methods Experimental Animals, Cells, and Human Subjects Details Cell Culture

[0155] Primary Human Brain Microvascular Endothelial cells (Cellsystems, ACBRI 376) were used for experiments. Cells were grown in complete classic Medium with serum and CultureBoostTM (Cellsystems, 4Z0-500) with 1% penicillin / streptomycin (Gibco, 15140-122). Cells between passages 5-8 were used for experiments. Animals

[0156] Male and female heterozygous 5xFAD mice (B6SJL, #034840-JAX) and corresponding WT littermates (B6SjLF1 / J, #100012), were purchased from the Jackson Laboratory and bred at our animal facility at Louis Stokes Cleveland VA Medical Center under specific protocol and guidance as approved by the IACUC (No.18-050-MS-21-007), in accordance with the guidelines of the National Institutes of Health Guide for the Care and Use of Laboratory Animals. Animals were maintained in a temperature and humidity- controlled room with a 12 h light / dark cycle. They were housed in a pathogen-free cage and with normal chow and water ad libitum and were observed continuously during all experimental procedures by the designated veterinarian. If required, veterinarian care was performed for sick animals. PS19 mouse experiments were performed in accordance with protocols approved by the IACUC of the Johns Hopkins University School of Medicine (No. MO21M457), in accordance with the guidelines of the National Institutes of Health Guide for the Care and Use of Laboratory Animals. Animals were housed in a temperature- controlled room (22°C) with a 12 h light / dark cycle and had access to normal chow and waterad libitum. Non-carrier and hemizygous (strain no #:008169) breeder pairs were procured from Jackson Laboratories and further bred to maintain the colony. Human samples

[0157] Human samples used in this study were obtained from Northwestern University Alzheimer’s Disease Research Center brain bank and Case Western Reserve University under approved study protocol. All samples were collected after providing written consent for the use of brain tissue. The Banner dataset from the human whole genome genotype and transcriptome data previously published1 was used to generate the RNA sequencing data for NAD+-synthesizing and degrading enzyme encoding genes. Human transcriptome database for male and female middle temporal gyrus (MTG) and dorsolateral prefrontal cortex (DLPFC) was analyzed from The Seattle Alzheimer’s Disease Brain Cell Atlas (SEA-AD) consortium. P7C3-A20 pharmacokinetics and binding analysis

[0158] P7C3-A20 levels in mouse plasma and brain were monitored by LC-MS / MS using an AB Sciex (Framingham, MA) Triple Quad™ 4500 mass spectrometer coupled to a Shimadzu (Columbia, MD) Prominence LC. P7C3-A20 was detected with the mass spectrometer in positive MRM (multiple reaction monitoring) mode by following the precursor to fragment ion transitions 507.1 to 204.3 (quantifier ion) and 507.1 to 136.2 (qualifier ion). An Agilent C18 XDB column (5 micron, 50 X 4.6 mm) was used for chromatography for PK studies with the following conditions: Buffer A: dH20 + 0.1% formic acid, Buffer B: methanol + 0.1% formic acid, 0 - 1.0 min 5% B, 1.0 - 1.5 min gradient to 100% B, 1.5 - 3.0 min 100% B, 3.0 – 3.15 min gradient to 5% B, 3.15 - 4.55% B. N- benzylbenzamide (transition 212.12 to 91.1) from Sigma (St. Louis, MO) was used as an internal standard (IS). Pharmacokinetic studies were performed by injecting 8-week-old B6SJLF1 / J male and female mice with 10 mg / kg P7C3-A20 IP formulated in 2.5% DMSO, 10% Kolliphor EL, 87.5% D5W (5% dextrose in water, pH 7.4) daily for four days. At various times following the fourth dose, animals were euthanized, blood was collected into K2EDTA tubes, mice were perfused with cold phosphate buffered saline (Fisher Scientific, BP399-20) and brains collected. Tissues were weighed before snap freezing and blood spun at 9600 x g to collect plasma which was stored frozen along with brain tissue at -80°C untilanalysis. Brain tissue was homogenized a T25 Ultra Turrax Tissue Disperser (IKA, Wilmington, NC) in a 3-fold volume (weight by volume) of PBS to generate a homogenate. Fifty µl of plasma mixed with 50 µl PBS or 100 µl of tissue homogenate was added to a Phree Phospholipid Removal Tabbed 1 mL Tube (Phenomenex, Torrance, CA) mounted on a Vacuum Extraction Manifold (Waters, Milford, MA.) Three hundred µl of acetonitrile containing 0.116% formic acid and 29 ng / mL n-benzylbenzamide IS was added, mixed 3x by pipetting, and a vacuum was applied. The flow through was collected and an additional 300 µl of acetonitrile containing formic acid and IS was passed over the tabbed tube and also collected. The flow through was transferred to an HPLC vial and analyzed as described above. Standard curves were generated using blank K2EDTA CD1 mixed gender mouse plasma (Bioreclamation, Westbury, NY) or blank CD1 brain tissue homogenate spiked with known concentrations of P7C3-A20 (Lot CR416FFS-7657-32-A-P) DMSO standards and processed as described above. The concentration of drug in each time-point sample was quantified using Analyst software (Sciex). A value of 3-fold above the signal obtained from blank plasma or tissue homogenate was designated the limit of detection (LOD). The limit of quantitation (LOQ) was defined as the lowest concentration at which back calculation yielded a concentration within 20% of theoretical. Concentrations for male and female mice were plotted separately but were nearly identical. Protein binding of P7C3-A20 in mouse plasma or brain homogenate was determined by rapid equilibrium dialysis using RED chambers (Thermo Scientific, Waltham, MA). On the day of the RED experiment, frozen mouse plasma and 3x homogenized blank brain was thawed in a water bath at 37°C. Then it was equilibrated for 45 minutes at 37°C in an atmosphere of 5% CO2. The pH of PBS was confirmed within 7.4 ±0.1. The pH of plasma and brain was measured and adjusted to 7.4 ±0.1 using concentrated acid or base. Plasma was diluted at 1:10 and brain diluted at 1:20 (final) with PBS and used for all subsequent steps. An aliquot of plasma or brain was spiked with compound to a compound concentration of 5 µM and vortex mixed. Enough non-spiked matrix remained to enable matrix matching of dialysate at the end of the binding assessment. This matrix was stored at 37°C in an atmosphere of 5% CO2. For each matrix, dialysis was performed using n=4 individual RED units with 200 µL of compound spiked plasma at 5 µM in the donor chamber and 400 µL of PBS in the dialysate chamber. The plate containing the RED units was sealed with a gas-permeable seal and incubated at 37°C for 6 hours under a 5% CO2atmosphere in an orbital shaker set to 100 rpm. At the end of the dialysis period,aliquots were taken from the donor and chambers of each RED unit to obtain post- dialysis measures of bound and unbound compound concentration. Donor, dialysate, and plasma or brain stability samples were analyzed by using a matrix matching approach whereby each sample was mixed in a 1:1 ratio with the opposite medium (blank matrix or PBS). The matrix matched samples were then processed as described above for PK samples. P7C3-A20 levels in both chambers were measured by LC-MS / MS as described above and the ratio of analyte / IS used in place of an absolute concentration as shown below to determine the % bound. For each matrix, stability was assessed by maintaining individual aliquots of compound-spiked matrix at 37°C and 5% CO2 for 0 and 6 hours. At each time point, n=250 µL aliquots were matrix matched and crashed. Stability of P7C3-A20 in plasma and brain was 95% or greater over 6 hours as assessed by LC-MS / MS. Fraction unbound (fu) was determined based on the following equations:^^^^^^^^^^ −after dialysis ^^^^^^ −concentration of compound in donor chamber after dialysis DF - dilution factor for plasma dilution ^^ ^^^^^^^^^ - fraction unbound after correcting for plasma dilution ^^ ^^^^^^^ −fraction unbound of diluted plasma; calculated using the fu equation above if using diluted plasma In vivo animal treatment

[0159] Two-month-old (for mid-disease cohort) and 6-month-old (for advanced-disease cohort) WT and 5xFAD mice were randomly divided into treatment groups and co-housed during the entire experiment. Intraperitoneal injections of vehicle (2.5% DMSO, 10% Kolliphor, and 5% Dextrose, pH 7.4) or P7C3-A20 (10 mg / kg) dissolved in vehicle were conducted every day in both cohorts. Animals were divided into 2 cohorts. Cohort 1 wasdesignated as the mid-disease group and injections every day from 2 months to 6 months. Cohort 2 was designated as the advanced-disease group and received injections every day 6 to 12 months. In each cohort, animals were divided into four treatment groups: WT VEH, 5xFAD VEH, WT P7C3-A20 and 5xFAD P7C3-A20. Each treatment group consisted of 20-25 males and 20-25 females. For PS19 mice experiments, 11-month-old PS19 male and female mice and corresponding WT animals were injected with P7C3-A20 or Vehicle for one month, with behavioral analysis after 15 and 30 days of treatment. Behavioral analysis Object recognition test

[0160] This 3-day task uses an open-topped box (50 x 50 x 30 cm) in which animals were habituated for 5 min on day one without any objects. On day two, animals were allowed to explore two similar objects for a total of 20 seconds. Each session had a maximum time of 10 min. On day three, the familiar object was replaced by a triplicate copy of the same object (to ensure there are no olfactory cues) and a novel object. Discrimination index was calculated by subtracting the exploration time for the new object from the exploration time for the old object divided by total exploration time (20 sec). Boxes and objects were cleaned between each testing session using Clidox. Animals were brought to the experimental testing room 30 min prior to the experiment for habituation. Elevated plus maze

[0161] This 5-minute test was performed only once per animal. To measure anxiety- like behavior, animals were placed in the center of a cross-shaped maze elevated 38 cm above the floor consisting of two open and two closed arms (50 cm). The behavior of the rodents was then monitored for 5 min by a video tracking system. Time spent in the open, closed, and center arms was automatically recorded using Anymaze software. Accelerating Rotarod Motor Coordination Test

[0162] In this three-day test, Rotamex 5 by Columbus Instruments was used to evaluate each animal's performance. On the first two days (learning phase), animals were trained on a rotarod that moved at a constant speed of 4 rpm for 600s, with three trials conducted for each animal with a one-hour gap between each trial. The graph was prepared based on the average of all three trials. On the third day, a probe test was conducted. The animals were placed onthe rotarod, which started at 4 rpm and at 1.2 rpm every 20 seconds until it reached 40 rpm. The time and acceleration speed were recorded for each animal when it fell from the rod. Three repeated tests were conducted for each animal, with an interval of one hour between each test. Porsolt forced swim test (FST)

[0163] Depression-like features in the animals were analyzed by FST. Animals were brought to the experimental testing room in their home cages on the day of each testing session and remained in the experimental room for 30 minutes prior to testing to habituate. Cylindrical swim tanks measuring 20 cm in diameter and 45 cm tall were filled with 24-25°C water to a height of 30 cm. Animals were placed in the tank for 6 minutes and the time spent immobile, defined as no detectable movement for ≥ 2 seconds, was recorded. Animals were removed with paper towels, gently blotted dry, and exposed to a warming pad to be sure they were observably dry before being returned to the room. Hindlimb clasping

[0164] Hindlimb clasping score was recorded for each animal by tail suspension for 30 sec. Animals were assigned a clasping score of zero if both hindlimbs were apart, a score of one if one hindlimb was touching the abdomen, and a score of two if both hind limbs were touching the abdomen. A score of three was allotted to animals that clasped all four limbs toward the abdomen. Morris Water Maze

[0165] Learning and memory were analyzed by the 5 day Morris water maze (MWM) test in which animals were motivated / trained to reach a hidden submerged platform. Animals were brought to the experimental testing room in their home cages on the day of each testing session and remained in the experimental room for 30 minutes prior to testing. The Morris water maze is a silver, circular water tank, measuring 167 cm in diameter filled with 24-25°C water to approximately 60 cm. A clear, plastic escape platform is submerged below the surface of the water, and the animals learn to locate this escape platform by utilizing four high contrast equally spaced spatial cues located around the maze. During each test, the animal was subjected to training comprised of four trials per day, and the time spent to find the platform was recorded, up to a maximum of 60 seconds. If the animal did notreached the platform by 60 seconds, it was manually guided to the platform and then removed from the maze. On day five, a probe trial was conducted, during which the platform was removed and the animal’s memory of the escape location based on spatial cues was analyzed. Anymaze video tracking software (Stoelting Co.) was used to measure the latency to cross the previous platform location. Sample harvesting

[0166] Animals were anesthetized with ketamine (100 mg / kg) and xylazine (10 mg / kg) and blood was isolated. Brain was dissected, collected in liquid nitrogen, and stored immediately at -80°C for further biochemical analysis. For the histopathological study, tissue was prepared as described previously. Briefly, mice were transcardially perfused with cold 1x phosphate buffer saline (PBS) followed by 4% paraformaldehyde in PBS (pH 7.4). Brains were collected and post-fixed in 4% paraformaldehyde in PBS (pH 7.4) overnight at 4°C. On the next day, brains were transferred to 30% sucrose in PBS for 72 h at 4°C and then rapidly frozen in 2-methylbutane chilled at -20°C. Next, 40 µm thick brain sections were prepared and preserved in cryoprotectant (150 mM Ethylene glycol, 100 mM glycerol, 250 mM PBS) at -20°C for further use. NAD+ / NADH measurement

[0167] Brain tissue NAD+ / NADH measurement was performed as per manufacture protocol (BioVision, K337- 100). Briefly, 20 mg of cortical brain tissue was washed with cold PBS, homogenized in NADH / NAD extraction buffer, and centrifuged at 14000 rpm for 5 min. The supernatant was filtered through a 10 kDa molecular weight cutoff filter to remove NADH-consuming enzymes. Fifty µL of diluted filtrate were used to assay NAD total (NADt) in a 96 well plate. Another 200 µL of the filtrate was heated to 60°C for 30 min to decompose NAD+, and 50 µl of diluted solution was added to the same 96 well plate to measure NADH. Ten µl of 1 nmol / ml NADH standard was diluted with 990 µL of NADH / NAD extraction buffer and 0, 20,40, 60, 80, and 100 pmol / well standard was added to the same 96 well plate as above with a final volume of 50 µl. An additional 100 µl of NAD cycling enzyme mix was added, mixed, and incubated at room temperature for 5 min. After this, 10 µL of NADH developer was added and absorbance was measured at 450 nm asdefined by manufacture protocol. For NAD+ / NADH in cell culture, HBMVECs were grown in 6 well plates (~2 x 106 cells / well) and treated with each treatment condition.

[0168] Then, cell pellets were washed in cold PBS and centrifuged at 900 g for 10 min. The pellet was further lysed with NADH / NAD extraction buffer, vortexed for 10 sec, and then centrifuged at 14000 rpm for 5 min before NAD+ / NADH measurement as described above for tissue. Brain Homogenate preparation for soluble / insoluble Aβ and p-tau measurement

[0169] Cortical brain tissue was homogenized with 500 µl of ice-cold radioimmunoprecipitation assay (RIPA) buffer (Sigma-Aldrich, R0278) supplemented with 1x phosphatase and protease inhibitors (Thermo Scientific, 1861284). Samples were allowed to stand for 15 min at 4°C and separated into three aliquots for Aβ, p-tau, and biochemical analysis and stored immediately at -80°C until further use. From one aliquot, 100 µl samples were taken and processed for Aβ analysis as previously described. Briefly, homogenate was centrifuged at 20,000 x g for 20 min at 4°C. The supernatant was used for Aβ 1-40 / Aβ 1-42 analysis in the soluble fraction. The pellet was then resuspended in threefold volume of 100% formic acid (Sigma-Aldrich, F0507) and dissolved by vortexing and pipetting, followed by overnight incubation at 4°C on a rotator. The next day, this solution was centrifuged at 20,000 x g at 4°C for 20 min and supernatant was neutralized by 19 volumes of 2 mol / L Tris buffer. This fraction was used for analysis of Aβ 1-40 / Aβ 1-42 in insoluble fraction. Another aliquot of 100 µl was processed for p-tau analysis as previously described. Briefly, 1 mM of phenylmethyl sulfonyl fluoride (Sigma Aldrich, P7626), 5 mM nicotinamide (Sigma-Aldrich, 72340), and 1 mM trichostatin A (Sigma-Aldrich, T8552) were added to the sample, followed by sonication and then centrifugation at 43,000 rpm for 15 min at 4°C. The supernatant was removed and centrifuged at 18,000 x g for 10 min at 4°C, and the resultant supernatant was used for p-tau analysis. Soluble insoluble Aβ 1-40 / 1-42 analysis

[0170] Soluble insoluble Aβ 1-40 / 1-42 analysis was done by using Human / Rat β Amyloid (42) or (40) ELISA Kit (Wako, High Sensitive (code no.292-64501, 294-64701)). Briefly, different dilutions of Aβ 40 (100, 50, 10, 5, 2.5, and 1 pmol / L) and Aβ 42 (20, 10,5, 2, 1,0.5, and 0.1 pmol / L) were prepared in the standard diluent. Both kits provided theantibody-coated microplate for analysis of and Aβ 42. For Aβ 40 analysis, the antibody-coated microplate was brought to room temperature. Then, 100 µL of standard diluent was added to a well as the blank. Other wells of the plate were coated with 100 µL of standard or sample for Aβ 40 analysis. For Aβ 42 analysis, the antibody-coated microplate was also brought to room temperature. Then, 100 µL of standard diluent was added to a well as the blank. Other wells of the plate were coated with 100 µL of standard or sample for Aβ 42 analysis. Both plates were sealed with plate seal and refrigerated overnight. On the next day, each well was washed 5 times with wash solution and 100 µL of HRP conjugated antibody solution was added into each well. Plates were sealed again and incubated in refrigeration for 1 h. After 1 h, solution was removed from each well and wells were washed 5 times. Then, TMB solution (100 µL) was added to each well and both plates were incubated in the dark at room temperature for 30 min. To terminate the reaction, stop solution (100 µL) was added to each well. Absorbance was recorded by a microplate reader (Spectra Max) at 450 nm. Western blotting

[0171] Western blotting was performed as described previously. Briefly, brain tissue homogenate in RIPA buffer with 1x protease and phosphatase inhibitors was sonicated and centrifuged at 18,000 x g at 4°C for 30 min. Supernatant was collected and protein concentration was measured by bicinchonic (BCA) protein assay kit (Thermo Scientific, A53225). An equal amount of protein sample for each analysis was mixed with Laemmli Sample buffer (Bio Rad Laboratories, Inc.#1610737) with beta-mercaptoethanol (Bio-Rad Laboratories, Inc., #1610710) and heated for 5 min. Proteins were resolved in 4 to 20% Criterion TGX Stain free gels (Bio-Rad Laboratories, Inc. #5678095) and transferred onto 0.2 µm polyvinylidene fluoride membranes (Bio-Rad Laboratories, Inc., #1704157) with the condition of mixed, high, or low molecular weight transfer (depending upon molecular weight of protein of interest) by Trans-Blot Turbo system (Bio- Rad Laboratories, Inc.). Membrane was blocked with 5% nonfat dry milk in tris-buffered saline-tween 20 (TBST) for 1 h at room temperature and then incubated with respective primary antibody at 4°C overnight. The following antibodies were used to probe the proteins of interest: rabbit-anti APP (Sigma, A8717, 1:5000), mouse anti-phospho-tau (Ser 202, Thr 205) (Invitrogen, MN1020B, 1: 1000), mouse anti-ZO1 (Thermo-Fisher Scientific, #33-9100, 1:500), rabbitanti-DNP (Millipore Sigma, kit #S7150, 1: 500), mouse anti-β-Actin (Santa Cruz Biotechnology, sc-47778,1:1000), mouse anti- NeuN (Millipore, MAB377, 1:1000), rabbit anti-GFAP (Cell Signaling Technology, #12389, 1:1000), rabbit anti-PSD95 ( abcam, ab18258, 1:1000), mouse anti-GAPDH (EMD Millipore Cor., MAB374, 1:5000). The next day, the membrane was washed with TBST (3 x 5 min) and incubated with horseradish peroxidase-conjugated secondary antibodies for 1 h. After washing of secondary antibodies (TBST, 3 x 5 min), the membrane was developed by Super SignalTM West Femto Maximum Sensitivity Substrate (Thermo Scientific, #34096) and the band was visualized by ChemiDocTM Imaging System (Bio-Rad) and in most cases auto optimal condition of the instrument was used. Exposure was set manually in some instances when bands were supersaturated or too faint. Image LabTM version 6.0.1 (Bio-Rad) was used to analyze the bands. Immunohistochemistry

[0172] For immunofluorescent staining of 6E10 and 500 µM ThioS, 40 µm brain sections were washed with PBS (3 X 3 min) and permeabilized with 0.25% Triton X-100 and blocked with 5% bovine serum albumin (BSA) and 5% normal horse serum (NHS) for 1 h at room temperature. Sections were incubated overnight with mouse anti-6E10 (Biolegend, 803001, 1:200) at 4°C and then with Alexa flour 594 donkey anti-mouse (Thermo-Fisher Scientific, A32744, 1:1000). Sections were then washed with PBS and incubated with 500 µM ThioS (Sigma, T1892) in 50% ethanol for 7 min. Sections were washed with 80% ethanol (2 x 3 min) then 95% ethanol (1 x 3 min) followed by one wash with distilled water and floated on the slide and mounted by VESTASHIELD mounting media (Vector Laboratories, H-1000). For NeuN, GFAP, Iba1, CD13, and CD31 staining, sections were washed with PBS and permeabilized with 0.25% Triton X-100 and blocked with 5% BSA and 5 % NHS (5% BSA and 5 % Normal donkey serum (NDS) for CD13, CD31) for 1 h at room temperature. Sections were incubated overnight with primary antibodies (mouse anti- NeuN; EMD Millipore Cor, #MAB377, 1:500; mouse anti-GFAP, Thermo-Fisher Scientific, MA5- 12023, 1:1500; rabbit anti-Iba1, Fujifilm, 019-19741, 1:500, goat anti-CD13, R & D system, # AF2335, 1:100; rat anti-CD31, BD Biosciences, # 550274, 1:100) at 4°C. The next day, sections were washed three times with PBS and incubated with secondary antibodies (Alexa Fluor 488 goat anti-mouse, Thermo Fisher Scientific, A32723, 1:200; Alexa Fluor594 goat anti-rabbit, Thermo Fischer A32740, 1:200) in 1% BSA for 1 h (1% NDS + 1% BSA for 2 h for CD13, CD31) at room temperature. Sections were mounted onto microscope slides (Fisher Scientific # 12-550-15) and then coverslipped with Prolong diamond antifade mountant (Invitrogen, P36961). DNA damage was analyzed using the TUNEL assay kit from Cell Signaling (# 25879), following the exact method described in the kit. Briefly, the free-floating sections were washed three times with PBS and then permeabilized for 30 minutes. After equilibration for 5 minutes, sections were incubated with TUNEL reaction buffer for 2 hours at 37°C. Finally, the sections were co-labeled with DAPI, mounted onto slides, and coverslipped for further analysis. Reactive oxygen species were analyzed by anti 4-hydroxynonenal (4-HNE) or anti-nitrotyrosine staining in free- floating sections blocked in 5% normal goat serum (S-1000, Vector Laboratories) and incubated overnight with rabbit anti-HNE (Alpha diagnostic International, #HNE11S, 1:500) or rabbit anti-3NT (Millipore Sigma, # AB5411, 1:500). On the following day, sections were incubated with goat anti-rabbit Alexa 594 or 488 (Invitrogen # A32740, #A32731,1:300,) for two hours at room temperature, washed in PBS, and mounted using an antifade aqueous media (Vectashield® Plus with DAPI, Vector Laboratories). Images were acquired on LSM 880, and mean fluorescence intensities were quantified on Fiji Image J. Cytokine analysis

[0173] Mouse brain hippocampus was homogenized in RIPA buffer containing protease and phosphatase inhibitor cocktail. Sample were centrifuged at 10,000 x g for 10 minutes at 4°C and supernatant was collected. Protein concentration was measured by BCA method and an equal amount of samples were analyzed by mouse cytokine 32-plex discover assay (Eve technology, Canada). Hippocampal neuronal survival

[0174] Survival of young hippocampal neurons was performed by BrdU labeling, as previously described. Briefly, for labeling newborn neurons a single dose of BrdU (150 mg / kg, i.p) was injected at the 5th month in mid-disease and 11th month in advanced disease cohort along with P7C3-A20 / vehicle injection. Thereafter P7C3-A20 / vehicle injections were continued up to the 6th month in mid-disease and 12 months for the advanced disease cohort. Brain tissue was harvested, and sectioning was performed as described above. Tomeasure survival of newborn hippocampal the number of BrdU+ cells / mm3 in the dentate gyrus was measured 30 days after BrdU injection. Free-floating 40 µm thick sections were stained for BrdU, and unmasking of BrdU was achieved by incubating the tissue sections for 2 h in 50% formamide / 2 x saline-sodium citrate (SSC) at 65°C followed by a 5 min wash in 2 X SSC and subsequent incubation for 30 min in 2 M HCL at 37°C. Sections were processed for immunohistochemical staining with mouse monoclonal anti-BrdU (Sigma, SAB4700630, 1:100). The number of BrdU+cells in the entire dentate gyrus and subgranular zone (SGZ) was quantified by counting BrdU+cells within the SGZ and dentate gyrus in every fifth section throughout the entire hippocampus and then normalized for dentate gyrus volume using Nikon Metamorph and NIH ImageJ software with appropriate conversion factors. Blood brain barrier integrity analysis

[0175] Blood-brain barrier (BBB) was analyzed by transmission electron microscopy (TEM) in the Cryo- Electron Microscopy Core facility of Case Western Reserve University, as previously described. Briefly, brain sections were washed three times with PBS and then fixed by quarter strength Karnovsky’s fixative solution for 2 h at room temperature. Sectioned were washed and postfixed for 2 h in an unbuffered 1:1 mixture of 2% osmium tetroxide (Electron Microscopy Science, 19110) and 3% potassium ferricyanide (Electron Microscopy Science, 20150). Sections were rinsed with distilled water and soaked overnight in an acidified solution of 0.25% uranyl acetate (Electron Microscopy Science, 22400). Sections were rinsed again and passed through ascending concentration of ethanol for dehydration and passed through propylene oxide (Electron Microscopy Science, 20401) and embedded in an EMbed 812 embedding media (Electron Microscopy Sciences, T300-Ni). Thin sections (70 nm) were cut on an RMC MT6000-XL ultramicrotome and mounted onto Gilder square 300 mesh nickel grids (Electron Microscopy Sciences). Sections were subsequently stained with acidified methanolic uranyl acetate and modified Sato’s triple lead stain. These sections were coated finally on a Denton DV-401 carbon coater (Moorestown, NJ) and examined in an FEI Tecnai Sprit (T12) with a Gatan US40004k x 4k resolution charge-coupled device. For analysis of IgG extravasation, brain sections were washed with PBS. Endogenous peroxidase activity was quenched by incubation of brain sections in 1% H2O2for 45 min and nonspecific staining was blocked by incubating the sections in 5% BSA.Sections were incubated in biotinylated IgG antibody (Vector Laboratories #BA- 2000, 1:500) overnight at 4°C. Sections were washed with PBS (3 x 5 min) and incubated with avidin–biotin complex (ABC kit, Vector Laboratories # PK-4000;) and developed using 3,3′-diaminobenzidine (DAB) (Peroxidase Substrate Kit, Vector Laboratories DAB # SK- 4100;). Brain sections were mounted onto the slides and cleared in xylene, and coverslipped. Reactive oxygen species detection through CellROX green and MitoSOX red

[0176] Briefly, cells were maintained and grown in the complete classic medium (Cell systems #4Z0-500) at 37°C in 95% air and 5% CO2 in a humidified incubator. At 80-90% confluency, cells were trypsinized, resuspended, and seeded into a 24-well black visiplate with a clear bottom (Perkin Elmer LLC, USA). All experiments were performed on cells between passage number 7 to 10. P7C3-A20 was dissolved in DMSO, and further dilutions were made in complete media with serum. On the following day, cells were treated with either Vehicle, 0.1 mM H2O2, or 5 µM P7C3-A20 in the presence of 0.1 mM H2O2. After 24 hours of treatment, cells were loaded with CellROX green reagent (ThermoFisher Scientific #C1044) at a final concentration of 5 μM and incubated at 37°C for 30 min. Thereafter, cells were washed and maintained in PBS for imaging. Images were captured immediately on the EVOS system using a GFP filter, after which cells were permeabilized with 0.5% Triton® X- 100 for 10 minutes, and fluorescence was read at excitation and emission of 485 and 520 nm, respectively. For the MitoSOX assay, cells were seeded either into 35 mm glass bottom Petri dishes (MatTek, Ashland, MA, USA, P35G-1.5-14-C) or 24- well black visiplate with a clear bottom (Perkin Elmer LLC, USA). All treatments were similar to CellROX green experiments. Following treatments, cells were loaded with MitoROX red® Reagent (ThermoFisher Scientific, M36008) at a final concentration of 5 μM and incubated at 37°C for 30 min. Thereafter, cells were washed, stained with Hoechst 33342, and maintained in HBBS for imaging. Images were captured immediately on a Zeiss fluorescent microscope. For quantitative estimation, cells grown and treated in visiplates were permeabilized with 0.5% Triton® X-100 for 10 minutes, and fluorescence was read at excitation and emission of 396 and 610 nm, respectively.Image acquisition and quantification of

[0177] Images were acquired by using Axio scan.Z1 (Zeiss) slide scanner or Axio Imager.M2 (Zeiss). In each set of experiments, light intensity and exposure time were kept constant. ImageJ version 1.42 software (National Institute of Health, Bethesda, MD) was used for image analysis. Percent area occupied by ThioS, 6E10, GFAP, Iba1, and NeuN in the whole hippocampus and whole cortex was measured. Integrated density of IgG was measured in the cortex and hippocampus. The fold change pericyte coverage was measured by % area occupied by C13 in CD31 positive area. Analysis conditions were kept identical throughout the group for each staining. All analysis was performed blindly for each treatment group. Measurement of mitochondrial respiration

[0178] Mitochondrial oxygen consumption rate (OCR) was measured using the Seahorse XFe96 Analyzer. HBMVECs were seeded (approximately 10,000 cells per well) in a sterile 96-well culture plate provided in the XFe96 Flux Pak (Agilent, 102601) and maintained for 24 h in Complete Classic Cell Medium with serum and CultureBoostTM (Cell System, 4Z0-500) until they reached approximately 70-80% confluency. Cells were then incubated with either 100 µM H2O2 or control media for 15 min, and subsequently treated with either vehicle, different concentrations of P7C3-A20 (1 µM, 3 µM, 5 µM), or 3 µM P7C3-A20 along with FK866. Plates were then incubated for an additional 24 h at 37°C in a humidified incubator containing 5 % CO2. The following day, mitochondrial assay media was prepared using XF DMEM (Agilent, 103680), fortified with 1 mM pyruvate (Agilent, 103578), 2 mM glutamine (Agilent 103579), and 10 mM glucose (Agilent, 103577). Mitochondrial complex inhibitors provided in the Cell Mito Stress Test kit (Agilent, 103015) were reconstituted in the mitochondrial assay media at the following 10x stock concentrations: oligomycin (12 µM), FCCP (10 µM), and Rotenone / Antimycin A (8.8 µM), and each was loaded into the corresponding, pre-calibrated plate as described in the Cell Mito Stress Test User Guide. Media was gently aspirated from the cell culture plate and replaced with 180 µL pre-warmed mitochondrial assay media. Cells were then incubated for 45 minutes at 37°C in a humidified incubator containing 5 % CO2 and then subjected to the “Cell Mito Stress Test” protocol pre-loaded on the Seahorse XFe96 Analyzer.Protein Carbonylation

[0179] Protein oxidation was assessed by estimating total protein carbonylation using the OxyBlot Protein Oxidation Detection Kit (Millipore Sigma, # S7150). Briefly, tissue was lysed in RIPA buffer, and 5 µg of homogenate was denatured using an equal volume of 12% SDS. Denatured samples were derivatized with 2,4-dinitrophenylhydrazine (DNPH), which enabled detection of carbonyl residues. Then, the derivatized samples were resolved on SDS- PAGE and detected with an anti-DNP antibody. Ex vivo electrophysiology study

[0180] Brain slices were prepared by dissecting six and twelve-month-old mouse brains by decapitation and immediately submerging into ice-cold and oxygenated cutting solution (110 mM sucrose, 60 mM NaCl, 3 mM KCl, 28 mM NaHCO3, 1.25 mM NaH2PO4, 5 mM glucose, 0.6 mM ascorbate, 7 mM MgCl2, and 0.5 mM CaCl2). Brain tissue was cut into 400 mm parasagittal sections in a cutting solution using Leica VT1200. Mouse hippocampal slice sectioning was done as described previously. Briefly, the hippocampus slice was dissected and maintained in room temperature cutting solution diluted 1:1 with artificial cerebrospinal fluid (ACSF) (in mM): (125 mM NaCl, 2.5 mM KCl, 26 mM NaHCO3, 1.25 mM NaH2PO4, 25 mM glucose, 1 mM MgCl2, and 2 mM CaCl2) for 20 min with constant 95% O2 / 5% CO2 perfusion. Slices were transferred and maintained in ACSF with constant 95% O2 / 5% CO2 perfusion for another 20 min before being transferred to the brain slice recording chamber (BSC1, Scientific Systems Design Inc.). Ex-vivo electrophysiology recording in mice hippocampal slices was performed as described previously. Briefly, brain slices were recovered for a minimum of 40 min before being transferred into the recording chamber, where temperature was held at 30° ± 0.5°C by Proportional Temperature Controller (PTC03, Scientific Systems Design Inc.). The ACSF flow rate was kept at 1 ml / min. Field excitatory postsynaptic potential (fEPSP) was recorded from stratum radiatum in hippocampal area CA1 via glass electrode (1–4 MΩ) loaded with ACSF. A stimulating electrode made by the formvar-coated nichrome wire (A-M Systems) was positioned on the Schaffer collaterals arising from the CA3 region, which was used to deliver biphasic stimulus pulses (100 μs duration). The electric stimulation, controlled by pClamp 11 software (Molecular Devices), was delivered via the Digidata 1550B interface (Molecular Devices) and a stimulus isolator (model 2200; A-M Systems). The evoked signals were amplified using a differentialamplifier (model 1800; A-M Systems), at 10 Hz low cut-off, 20 kHz high cut-off, and digitized at 10 kHz. Input-output was performed at 0.5 mV increments to yield the maximum response. A stimulus intensity that would evoke less than 50% of the maximum fEPSP response was determined and used in all the electrophysiological recordings. A 20 min baseline fEPSP was recorded at 0.05 Hz as a control before the long-term potentiation (LTP) induction. LTP was induced by a high-frequency theta burst stimulation (TBS), which consisted of five trains of 200 Hz in 20 ms duration separated by 200 ms, repeated 6 times at 10 s intervals. A 60 min fEPSP was recorded at 0.05 Hz following the TBS. Label-free Quantitative proteomic analysis Sample preparation

[0181] Hippocampal brain tissue was homogenized in 500 µl of ice-cold radioimmunoprecipitation assay (RIPA) buffer (Sigma-Aldrich, R0278), supplemented with 1x phosphatase and protease inhibitors (Thermo Scientific, 1861284). The samples were allowed to stand for 15 minutes at 4°C and then sonicated. Following sonication, they were centrifuged at 18,000 x g at 4°C for 30 minutes. The supernatant obtained from this step was used for proteomic analysis. In brief, 200 µg of total proteins were ship on dry ice to Creative Proteomics (Shirley, New York, USA), where the proteins were precipitated using cold acetone. The proteins were then dissolved in 2M urea and denatured with 10 mM dithiothreitol (Sigma-Roche, 10197777001) at 56°C for 1 hour, followed by alkylation with 50 mM Iodoacetamide (Sigma, A3221) for 60 minutes in the dark at room temperature. Next, 500 mM ammonium bicarbonate (Sigma, A6141) was added to achieve a final concentration of 50 mM ammonium bicarbonate with a pH of 7.8. The samples were digested with Promega Trypsin (Promega, V5111) for 15 hours at 37°C. The resulting peptides were further purified using a C18 SPE column (Thermo Scientific), lyophilized, and then resuspended in 20 µl of 0.1% formic acid (Sigma, 1.59013) for LC-MS / MS analysis. Nano LC-MS / MS analysis

[0182] Nanoflow UPLC, Ultimate 3000 nano UHPLC system (Thermo Scientific, Waltham, MA) was used for the study. Nanocolumn was conditioned and 1 µg of sample was loaded with a mobile phase A 0.1% formic acid in water and mobile phase B 0.1% formic acid in acetone with total flow rate of 250 nL / min. LC linear gradient was performed from 2to 8% buffer B in 5 min, from 8% to 20% B in 60 min, from 20% to 40% buffer B in 33 min, then from 40% to 90% buffer B in 4 min. Mass Spectrometry was performed by full scan between 300-1,650 m / z at the resolution 60,000 at 200 m / z, the automatic gain control target for the full scan was set to 3e6. The MS / MS scan was operated in Top 20 mode using the following settings: resolution 15,000 at 200 m / z; automatic gain control target 1e5; maximum injection time 19ms; normalized collision energy at 28%; isolation window of 1.4 Th; charge sate exclusion: unassigned, 1, > 6; dynamic exclusion 30 s. Data analysis

[0183] Raw MS files were analyzed and searched against mouse protein database based on the species of the samples using Maxquant (1.6.2.14). The parameters were set as follows: the protein modifications were carbamidomethylation (C) (fixed), oxidation (M) (variable); the enzyme specificity was set to trypsin; the maximum missed cleavages were set to 2; the precursor ion mass tolerance was set to 10 ppm, and MS / MS tolerance was 0.5 Da. Data was normalized and the cutoff value between the groups was ± 1.25 fold change with p- value ≤0.05 was considered significant for further bioinformatics analysis. The group normalized data for both male and female is represented in data table. Bioinformatics analysis

[0184] Global protein changes across different groups were analyzed and visualized using VolcaNoseR. In this analysis, the log10 (fold change) of each protein was plotted on the x-axis against the log10 of its p-value on the y-axis. Proteins with a p-value of ≤ 0.05 and a fold change ≥ 1.25 are represented as red dots, indicating upregulated proteins. Conversely, proteins with a p-value of ≤ 0.05 and a fold change ≤ 1.25 are represented as blue dots, indicating downregulated proteins. The identified proteins, which showed statistically significant changes in abundance, were then used for Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses across different groups. Enrichment analysis was conducted using the Mus musculus database for mice and Homo sapiens, employing ShinyGO V0.80.12 Top five enrichment terms with least FDR value for up and down regulated proteins were represented in the graph. Data visualization for all the enrichments, including the heat map, was created using SRplot.13Human Database Analysis

[0185] The proteomic label changes observed in 5xFAD VEH mice were examined in the report compiled by Askenzi et al. (2023),2 which is based on 38 published reports on Alzheimer’s disease (AD) proteomics. We focused on proteins that were altered at different clinical stages of AD. We analyzed the significantly differentially expressed proteins in 5xFAD VEH mice compared to wild-type (WT) VEH mice, applying a p-value threshold of ≤ 0.05 and a fold change of ≥ 1.25. We checked for similar directional changes of these proteins at various stages of AD as reported in the article. The NeuroPro Score for each identified protein is indicated in the heatmap (Fig.6H). For the human transcriptomic database, we explored the transcriptome patterns of the identified differentially expressed proteins (DEPs) using the public, large- scale single-nuclei RNA sequencing dataset from The Seattle Alzheimer’s Disease Brain Cell Atlas (SEA-AD) consortium (https: / / portal.brain- map.org / explore / seattle-alzheimers-disease / whatis and Gabitto et al., 2024). This dataset includes samples from two brain regions: the middle temporal gyrus (MTG) and the dorsolateral prefrontal cortex (DLPFC). Using a pseudo-bulk based method (muscat1),14 we conducted differential expression analysis (AD vs. healthy controls) for female and male donors across different brain regions and cell types (Fig.6 and 7I-J). The significant differentially expressed genes (DEGs) are defined by a p-value of <0.05 and |logFC| > 0.25, and these are highlighted in the heatmap. Statistical analysis

[0186] All statistical analysis and graphical representations were performed using GraphPad Prism, version 10.2.3 (GraphPad Software, Inc.). For analysis of two groups, the student’s t-test was performed. For multiple group analysis, one-way ANOVA or repeated- measured two-way ANOVA with Dunnett’s post hoc test were used when appropriate. Data are shown as mean ± SEM. For the 5xFAD study, blue dots represent female animals and red dots represent male animals. P-value below or equal to 0.05 was considered significant. For mayo Banner temporal cortex bulk RNA sequencing dataset, count data were normalized using TNN method with edgeR package, and differential gene expression was performed with linear regression. Different significant levels 0.05, 0.01, 0.001, and 0.0001 were represented by *, **, ***, and **** respectively. Individual significance levels for each figure were described in the specific figure legends.Results Normalization of brain NAD+homeostasis in amyloid-driven AD mice by P7C3-A20

[0187] To begin, we examined whether the 5xFAD mouse model of AD displayed impaired NAD+homeostasis with disease progression. We chose 5xFAD mice not only for their characteristic Aβ aggregation but also because they progressively develop tau pathology in advanced stages, including the Ser202 / Thr205 tau phosphorylation that is typical of human AD, despite lacking genetic mutations in tau. Importantly, 5xFAD mice also exhibit other hallmark features of AD, including BBB deterioration, oxidative stress, DNA damage, neuroinflammation, impaired hippocampal neurogenesis, deficient synaptic plasticity, neurodegeneration, and cognitive decline. At two months of age, prior to symptomatic development, we did not detect a difference in brain levels of NAD+ / NADH between 5xFAD mice and their wild type (WT) littermates (Fig.7A). At six months of age, however, when 5xFAD mice characteristically display overt pathology and cognitive impairment, a significant 30% reduction in brain NAD+ / NADH was observed in 5xFAD mice compared to their WT littermates (Fig.7A). This deficit escalated to 45% by twelve months of age (Fig.1A), indicating that brain NAD+homeostasis declines with disease progression. To explore the potential for pharmacologic normalization of NAD+homeostasis, we treated 5xFAD mice with P7C3-A20, a neuroprotective compound known to restore NAD+homeostasis, without elevating NAD+above normal. Substantial evidence across multiple laboratories supports the protective efficacy of P7C3 compounds and their ability to safely normalize NAD+homeostasis without leading to harmful increases, offering highly effective protection in models of both neurodegeneration and peripheral disease related to energy depletion, as well as neuroprotective efficacy in non-human primates. After administering four daily doses of P7C3-A20 (10 mg / kg) via intraperitoneal (IP) injection, we confirmed steady-state levels of the compound in both plasma (Fig.7B) and brain (Fig.7C), with regular sampling over a 25- hour period after the final dose. Brain NAD+ / NADH levels at the same time points were equivalent to vehicle-treated controls (Fig.7D), confirming that P7C3-A20 does not elevate NAD+to higher-than-normal levels. Notably, there were no sex- specific variations in P7C3-A20 or NAD+ / NADH levels across blood or brain samples. Thus, P7C3-A20 treatment achieved stable levels in both plasma and brain without disrupting normal brain NAD+homeostasis of WT mice. Encouragingly, daily P7C3-A20 treatmentfrom two to six months of age effectively any disruption in NAD+homeostasis in 5xFAD mice (Fig.7A). Moreover, when treatment was postponed until the window of six to twelve months of age, NAD+homeostasis was restored in 5xFAD mice (Fig.1A). Thus, P7C3-A20 treatment both preserves and restores NAD+homeostasis in this model of AD. Experimental design for testing prevention and reversal of AD

[0188] The ability to safely preserve and restore NAD+homeostasis in 5xFAD mice prompted us to investigate whether early intervention with P7C3-A20 could preserve brain resilience and prevent the onset of AD, as well as whether later treatment with P7C3-A20 could reverse the disease and restore cognitive function. To assess preventative efficacy, we initiated daily P7C3-A20 treatment (10 mg / kg / day, intraperitoneal (IP)) or vehicle control at two months of age, prior to the emergence of symptomatic behavior, and maintained this regimen until six months of age, when cognitive impairments typically manifest (Fig.7E). For testing the possibility of AD reversal, we administered P7C3-A20 or vehicle starting at six months of age and continuing until twelve months, coinciding with the period of severe pathology and cognitive decline (Fig.1B).

[0189] Behavioral assessments were scheduled one month before endpoint analysis, at which time the thymidine analog bromodeoxyuridine (BrdU) was administered to label dividing cells for measuring postnatal hippocampal neurogenesis, which is characteristically diminished in AD. Following behavioral testing, brains underwent comprehensive assessments through immunohistochemical, biochemical, and transmission electron microscopy (TEM) analysis. In this manuscript, “mid-disease stage” refers to six-month-old mice that were treated daily with either P7C3-A20 or vehicle from two to six months of age, while “advanced-disease stage” denotes twelve-month-old mice that were treated daily with either P7C3-A20 or vehicle from six to twelve months of age. Prevention and reversal of cognitive and behavioral symptoms in amyloid-driven AD mice by P7C3-A20

[0190] Cognitive impairment is the salient symptomatic feature of AD, significantly impacting patient well-being and quality of life. Given that P7C3-A20 treatment preserved and restored brain NAD+homeostasis in 5xFAD mice, we hypothesized that it could also mitigate cognitive decline.

[0191] To evaluate cognitive first utilized the novel object recognition (NOR) test of cognition, which assesses recognition memory based on mice’s natural tendency to explore new objects longer than familiar ones. A lower discrimination index, which indicates impaired recognition memory, was observed in vehicle-treated mid- and advanced-disease 5xFAD mice (Fig.7F and 1C). Remarkably, P7C3-A20 treatment not only prevented this cognitive deficit in mid-disease mice (Fig.7F), but also fully reversed it in advanced disease mice (Fig.1C). There were no effects of P7C3-A20 treatment on WT mice in this task.

[0192] We next assessed cognitive function using the Morris water maze, a test of spatial learning and memory. In this procedure, mice learn to locate a submerged and visually concealed platform using external visual cues. Learning is demonstrated by decreased time to find the platform over successive trials. Mid-disease 5xFAD mice displayed impaired learning, evidenced by increased latency on days 2, 3, and 4, which was effectively prevented by P7C3-A20 (Fig.7G). Similarly, mid-disease mice showed reduced crossings of the area from which the platform was removed in the probe trial of memory, a deficit that was also prevented by P7C3-A20 (Fig.7G). Strikingly, the even more severe learning and memory impairments in advanced-disease 5xFAD mice were completely reversed by P7C3-A20 (Fig.1D). P7C3-A20 treatment did not impact performance of WT mice in this task.

[0193] We also examined motor coordination and learning through the accelerating rotarod task. Here, mice remain on a circular turning rod that gradually increases in speed until they fall. Mid-disease 5xFAD mice performed normally throughout the learning and probe phases, irrespective of P7C3-A20 treatment (Fig.7H). Conversely, advanced-disease 5xFAD mice exhibited significant impairments in both learning and memory, which were prevented by P7C3-A20 (Fig.1E). Importantly, treatment with P7C3-A20 did not alter cognitive or motor function in WT mice at either stage.

[0194] In addition to cognitive impairment, anxiety and depression are also common features of AD. To assess anxiety-like behavior, we employed the elevated plus maze (EPM), a four-armed maze with open and closed arms. Increased time spent in the closed arms reflects anxiety-like behavior due to the inherent fearfulness of mice to remain exposed in open spaces. Interestingly, 5xFAD mice characteristically display an abnormally greater amount of time in the open arms, a behavior we confirmed in both mid- and advanced-diseasestages (Fig.7I and 1F). As with cognition, A20 treatment prevented and reversed this aberrant behavior (Fig 7I and 1F) and had no effect on WT mice. We next evaluated depression-like behavior in the forced swim test, wherein increased immobility time indicates depression. Mid-disease 5xFAD mice showed normal behavior (Fig.7J), while advanced- disease 5xFAD mice showed unexpectedly lower immobility that was normalized by P7C3- A20 (Fig.1G).

[0195] Finally, we assessed hind-limb clasping, which provides a measure of general disease progression in mouse models of neurodegeneration. Mid-disease mice did not exhibit hindlimb clasping, whereas advanced-disease mice did (Fig.1H). Notably, this was prevented by P7C3-A20 treatment (Fig.1H). Administration of P7C3-A20 to WT mice had no impact on any of these additional neuropsychiatric measures at either time point. Prevention and reversal of impaired hippocampal synaptic plasticity in amyloid-driven AD mice by P7C3-A20

[0196] Impaired synaptic plasticity is a key feature of AD that is closely linked to cognitive decline. To investigate synaptic transmission in 5xFAD mice, we performed ex vivo electrophysiological recordings of long-term potentiation (LTP) in acutely isolated hippocampal slices (Fig.7K). We found no differences in baseline synaptic transmission at either the mid-disease or advanced-disease stages, regardless of P7C3-A20 treatment, as indicated by field excitatory postsynaptic potential (fEPSP) input / output (I / O) curves (Fig.7L, M). However, LTP induced by theta- burst stimulation was significantly reduced in mid-disease 5xFAD mice (Fig.7N) and even more severely impaired in advanced-disease 5xFAD mice (Fig.1I). Importantly, P7C3-A20 prevented the LTP deficit in mid-disease mice (Fig.7N) and completely reversed the impairment in advanced-disease mice (Fig.1I).

[0197] Both the induction and maintenance phases of LTP were normalized, the latter exemplified during the final 10 min of recording (50-60 min) (Fig.7O and 1J). P7C3-A20 treatment did not affect any measures in WT mice at either time point. In summary, treatment with P7C3-A20 effectively prevented and reversed synaptic plasticity deficits in 5xFAD mice, in line with its ability to prevent and reverse cognitive impairment.Prevention and reversal of amyloid and tau pathology in amyloid-driven AD mice by P7C3- A20

[0198] We next investigated whether P7C3-A20 treatment could also prevent and reverse the classical amyloid and tau pathology observed in 5xFAD mice. To begin, we used Thioflavin-S staining to examine amyloid structures, which are long unbranched protein fibers with extended secondary β-sheets forming rigid and proteolysis-resistant fibrils. These amyloid structures form due to protein misfolding in various human disorders, including AD. The formation of amyloid structures is actively combatted in the cell through an extensive proteostasis autophagic network that relies heavily on normal NAD+homeostasis. Strikingly, P7C3-A20 treatment significantly prevented the accumulation of amyloid structures in pathological extracellular plaques throughout the cortex and hippocampus of mid-disease 5xFAD mice (Fig.8A), and reversed plaque accumulation in advanced-disease 5xFAD mice (Fig.2A).

[0199] This reduction in plaque pathology occurred without interfering with abnormal Aβ production, as shown by using the 6E10 monoclonal antibody that recognizes amino acids 1-16 of Aβ. P7C3-A20 did not prevent (Fig.8B) or reverse (Fig.2B) genetically driven Aβ aggregation in 5xFAD mice. Furthermore, levels of amyloid precursor protein (APP), soluble Aβ peptides (1-40 and 1-42), and insoluble Aβ peptides (1-40 and 1-42) in 5xFAD mice were unchanged by P7C3-A20 treatment in both mid-disease (Fig.8C-E) and advanced- disease (Fig.2C-E) stages. These peptides are the primary components of brain Aβ aggregates, generated by sequential cleavage of APP by β-site APP-cleaving enzyme 1 (BACE-1) and β- secretase. Since neither enzyme is regulated by NAD+, we did not expect P7C3-A20 to impact these early stages of amyloid pathology in 5xFAD mice. It appears, however, that P7C3-A20 treatment enabled the brains of 5xFAD mice to better manage the substantially elevated levels of aberrant Aβ production in ways that mitigated plaque accumulation. This is likely due to restoration of autophagy-mediated clearance of pathological amyloid, an NAD+-dependent process known to be significantly impaired in AD.

[0200] We did not observe pathological tau phosphorylation in mid-disease 5xFAD mice (Fig.8). However, advanced-disease 5xFAD mice exhibited prominent tau phosphorylation at Ser202 / Thr205, consistent with advanced disease pathologytherapeutically prevented by P7C3- A20 and F). Importantly, P7C3-A20 treatment did not affect any measures of amyloid or tau in WT mice at either time point. Prevention and reversal of BBB deterioration in amyloid-driven AD mice by P7C3-A20

[0201] The integrity and function of the BBB are crucial for neuronal health and survival. In AD, early BBB deterioration occurs before cognitive symptoms develop. The BBB also deteriorates early in 5xFAD mice. Using transmission electron microscopy (TEM), we observed disrupted astrocytic end-feet at the BBB in mid-disease 5xFAD mice, resulting in open gaps around blood vessels. This disruption was completely prevented by P7C3-A20 treatment (Fig.8F), consistent with previous reports of P7C3-A20 enabling BBB repair.

[0202] BBB deterioration was even more severe in advanced-disease 5xFAD mice, with P7C3- A20 treatment fully reversing this pathology (Fig.2G). Loss of structural integrity of the BBB correlated with loss of function, as both mid- and advanced-disease 5xFAD mice exhibited abnormal infiltration of peripheral immunoglobulins (IgG) into brain parenchyma. In 5xFAD mice, P7C3-A20 treatment completely prevented IgG infiltration in mid-disease (Fig.8G) and reversed it in advanced-disease (Fig.2H).

[0203] We also assessed BBB pericytes, which characteristically degenerate in human AD and are crucial for regulating vascular stability, capillary flow, and toxin clearance from the brain. Pericyte coverage of microvascular endothelial cells of the BBB was reduced at both mid-disease (Fig.8H) and advanced-disease (Fig.2I) stages, with P7C3-A20 treatment preventing and reversing this reduction, respectively.

[0204] Lastly, we evaluated expression of zonula occludens 1 (ZO-1), a tight junction protein in BBB microvascular endothelial cells known to be decreased in human AD. ZO-1 expression was reduced in advanced-disease 5xFAD mice, a deficit that was prevented by P7C3-A20 treatment (Fig.2J). Mid-disease 5xFAD mice did not show abnormal levels of ZO-1 (Fig.8I). Notably, treatment with P7C3-A20 did not affect BBB measures in WT mice at either time point. Prevention and reversal of DNA damage and neuroinflammation in amyloid-driven AD mice by P7C3-A20

[0205] Accumulation of DNA damage in the aging brain is exacerbated in AD and linked to neuroinflammation. We observed this in 5xFAD mice using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, which detects DNAstrand breaks and serves as an indicator of damage. We detected significantly elevated DNA damage in both mid- disease and advanced-disease 5xFAD brains, which was prevented and reversed, respectively, by treatment with P7C3-A20 (Figs.9A and 3A). Treatment of WT mice with P7C3-A20 did not affect DNA damage at either time point.

[0206] We next examined neuroinflammation, a cause and consequence of neurodegeneration in AD, by examining levels of astrocytic glial fibrillary acidic protein (GFAP), a well-established marker of neuroinflammation in human AD. This intermediate filament protein is highly expressed when astrocytes are in a proinflammatory reactive state characterized by release of harmful cytokines, inflammatory mediators, nitric oxide, and reactive oxygen species. We observed elevated GFAP levels in both mid-disease and advanced-disease 5xFAD mice, which were mitigated by P7C3-A20 treatment (Fig.9B and 3B).

[0207] Next, we measured brain levels of another marker for neuroinflammation: ionized calcium- binding adaptor molecule 1 (IBA1). IBA1 indicates activated microglia that secrete neurotoxic factors, including tumor necrosis factor, nitric oxide, and reactive oxygen species. IBA1 levels were elevated in both mid-disease and advanced-disease 5xFAD mice and reduced by P7C3-A20 (Fig.9C and 3C).

[0208] Lastly, we examined brain inflammatory cytokines secreted by microglia and astrocytes, which play a role in modulating neuroinflammation. Specifically, we measured levels of interleukin-2 (IL-2), interleukin-13 (IL-13), tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ). IL-2, which supports neurons and glia, is essential for hippocampal-mediated cognition and decreased in human AD brains. Although IL-2 levels were unchanged in mid-disease 5xFAD mice, we detected significantly decreased IL-2 in advanced-disease mice, which was prevented by P7C3-A20 (Fig.9D and 3D). IL-13, which is also important for cognition, was similarly significantly decreased in advanced-disease 5xFAD mice and preserved by P7C3-A20 (Figs.9D and 3D). TNF-α and IFN-γ, which are neurotoxic at high concentrations, did not change in any group (Figs.9D and 3D). Importantly, treatment with P7C3-A20 did not affect neuroinflammation measures in WT mice at either time point.Protection from neurodegeneration in driven AD mice by P7C3-A20

[0209] A prominent feature of AD is progressive neurodegeneration, which leads to neuronal loss that can be measured by reductions in the specific neuronal marker NeuN. This deficit was not displayed in mid-disease symptomatic 5xFAD mice (Fig.9E), indicating that neuronal loss is not required for manifestation of AD-like symptoms. However, we noted a significant decrease in NeuN levels in advanced-disease 5xFAD mice, which was completely prevented by treatment with P7C3-A20 (Fig.3E).

[0210] Another aspect of neurodegeneration in AD involves reduced survival of young hippocampal neurons generated through postnatal hippocampal neurogenesis, a process that is abundant in the healthy brain but severely impaired in both human and mouse AD, including 5xFAD mice. At the mid-disease stage, we observed a trend towards decreased survival of young postnatally-born hippocampal neurons in 5xFAD mice (Fig.9F). At the advanced- disease stage, 5xFAD mice showed significantly reduced survival of these young neurons, which was prevented by P7C3-A20 (Fig.9F). Restoration of NAD+homeostasis and protection against oxidative damage in mouse AD brain and human brain microvascular endothelial cells by P7C3-A20

[0211] Oxidative and nitrosative stress are prominent features of human AD brains, and we confirmed this in both our human samples and animal models. Key forms of oxidative and nitrosative stress identified in the AD brain include 4-hydroxynonenal (4-HNE), 3- nitrotyrosine (3-N-Tyr), and protein carbonylation. 4-HNE, which is a highly toxic byproduct formed from the peroxidation of polyunsaturated fatty acids in cell membranes, causes significant mitochondrial damage. Increased levels of 4-HNE were noted in mid- disease 5xFAD mice, and treatment with P7C3-A20 effectively prevented this increase (Fig.10A). In advanced-disease 5xFAD mice, 4-HNE levels further escalated and were reversed by P7C3-A20 (Fig.4A).

[0212] The conversion of tyrosine residues in proteins to 3-N-Tyr occurs through the action of peroxynitrite, a harmful compound generated by the reaction of nitric oxide with superoxide anions. Elevated levels of 3-N-Tyr are a characteristic feature in the brains of people with AD. In our studies, we saw a significant rise in 3-N-Tyr levels in mid-disease 5xFAD mice, which P7C3-A20 successfully prevented (Fig.10B). Moreover, 3-N-Tyr levels were markedly increased in advanced-disease 5xFAD mice and completely reversed byP7C3-A20 treatment (Fig.4B). Similarly, heightened protein carbonylation in both mid-disease and advanced-disease 5xFAD mice, additionally observing that P7C3-A20 not only prevented this in mid-disease but also reversed it in advanced-disease (Figs.10C, D). P7C3-A20 treatment did not impact any of these measures in WT mice at either time point.

[0213] Since oxidative stress damages the BBB, and the BBB is deteriorated in both human AD and 5xFAD mice, we further investigated the protective role of P7C3-A20 in a human model of BBB deterioration. Specifically, we exposed cultured human brain microvascular endothelial cells (HBMVECs), the most abundant component of the BBB, to oxidative stress induced by hydrogen peroxide (H2O2). This caused depletion of NAD+ / NADH in HBMVECs, an effect that was dose- dependently mitigated by P7C3-A20 (Fig.4C). The protective efficacy of P7C3-A20 in this model depended on its ability to restore NAD+homeostasis, as it was blocked by exposure to FK866 (Fig.4C), which inhibits nicotinamide phosphoribosyltransferase (NAMPT), the rate limiting enzyme in the conversion of nicotinamide to NAD. Importantly, as with WT mouse brain, treating healthy HBMVECs with P7C3-A20 did not alter NAD+-homeostasis (Fig.4D).

[0214] We subsequently observed that elevated oxidative stress in HBMVECs caused by H2O2 exposure was also completely prevented by P7C3-A20, as indicated by the CellROX green assay (Fig.4E). We also measured mitochondrial superoxide levels, another indicator of oxidative cellular damage, using MitoSOX Red analysis, which fluoresces upon oxidation by mitochondrial superoxide. H2O2exposure increased MitoSOX Red signal, which was completely inhibited by P7C3-A20 (Fig.4F).

[0215] Given that oxidative stress impairs mitochondrial function, we further assessed mitochondrial responsiveness in HBMVECs using the Seahorse bioanalyzer and mitochondrial stress testing, through exposure to oligomycin, carbonyl cyanide 4- (trifluoromethoxy) phenylhydrazone (FCCP), and rotenone / antimycin A. We found that baseline oxygen consumption rate was unaffected by either H2O2 or P7C3-A20 (Fig.4G). Following inhibition of ATP synthase by oligomycin, FCCP-mediated uncoupling of the membrane potential was applied to generate a level of energy demand that induces the electron transport chain to work at maximal capacity to restore the proton gradient. Subsequent exposure to a combination of rotenone (a complex I inhibitor) and antimycin A (a complex III inhibitor) suppressed mitochondrial respiration, such that any residual oxygenconsumption was non-mitochondrial. respiration (Fig.4H), mitochondrial spare reserve capacity (Fig.4I), and maximal mitochondrial respiration rate (Fig.4J) were reduced in HBMVECs by H2O2 exposure, but preserved by P7C3-A20. This protective effect relied on the normalization of NAD+homeostasis because it was blocked by FK866 (Fig.4G- J). Disrupted NAD+homeostasis correlates with disease severity in human and mouse AD

[0216] Disrupted brain NAD+homeostasis has previously been reported in the aging human brain. Here, we show that our human AD brain samples, which displayed approximately double the amount of AD-specific phosphorylated tau at amino acids serine 202 (Ser202) and threonine 205 (Thr205) (Fig.11A), showed a significant 30% reduction in NAD+ / NADH (Fig.4A). Notably, this is the first report of impaired NAD+homeostasis in the human AD brain.

[0217] Next, we examined whether the extent of NAD+homeostasis disruption correlated with the severity of the various AD outcome measures in mouse and human AD. Here, we observed a significant negative correlation between human brain NAD+homeostasis disruption and the magnitude of tau pathology (Fig.5B and 11A), protein carbonylation (Fig.5C and 11B), and GFAP levels (Fig.5D and 11C). This indicated that more severely perturbed brain NAD+homeostasis was correlated with a greater extent of vulnerability to tau pathology, oxidative protein damage, and neuroinflammation, respectively, in the human AD brain. We also observed a significant positive correlation between human brain NAD+homeostasis disruption and the magnitude of levels of ZO-1 (Fig.5E and 11D) and NeuN (Fig.5F and 11E), indicating that more severely perturbed brain NAD+homeostasis was additionally correlated with greater BBB deterioration and neuronal cell death, respectively, in human AD brain. Lastly, we observed a compelling relationship between human brain NAD+homeostasis disruption and PSD-95 levels (Fig.5G and 11F), supporting a role for disrupted NAD+homeostasis in impaired synaptic transmission in human AD brain.

[0218] Importantly, we detected the same relationships in the brains of 5xFAD mice. For example, advanced-disease 5xFAD mice showed a significant negative correlation of brain NAD+homeostasis disruption and the magnitude of tau pathology (Fig.5H) and protein carbonylation in the brain (Fig.5I), with mid-disease 5xFAD mice showing a similar trendwith respect to protein carbonylation . Thus, as with the human AD brain, more severely perturbed NAD+homeostasis is correlated with greater vulnerability to tau pathology and oxidative protein damage in 5xFAD mice. With respect to neuroinflammation, we observed a positive correlation between brain NAD+ / NADH and levels of IL-2 (Fig.5K) and IL-13 (Fig.5L) in advanced-disease 5xFAD mice, indicating that, as with human AD, more severely perturbed brain NAD+homeostasis is correlated with greater neuroinflammation in the brains of symptomatic 5xFAD mice. Additionally, we observed a positive correlation in advanced-disease 5xFAD mice between brain NAD+homeostasis disruption and ZO-1 levels in the brain (Fig.5M), indicating that, as with human AD, more severely perturbed brain NAD+homeostasis is correlated with greater BBB deterioration in the brains of 5xFAD mice.

[0219] In mice, as opposed to humans, we were additionally able to investigate the relationship between disrupted NAD+homeostasis and cognitive performance in 5xFAD mice. Here, we observed a very strong correlation at both mid-disease and advanced-disease stages between disrupted brain NAD+homeostasis and impaired discrimination index in the NOR task (Fig.5N,O), reduced number of platform crossings in the MWM probe memory test (Fig.5P,Q), and slower rotation speed at the time of falling in the accelerating rotarod test (Fig.5R,S). These correlations demonstrate that more severely perturbed brain NAD+homeostasis correlates with greater cognitive impairment in 5xFAD mice.

[0220] As our studies of human post-mortem tissue precluded behavioral assessment in human AD, we conducted expression profiles of NAD+-synthesizing and NAD+-consuming enzymes in human AD and NDAN brains, relative to non-AD / non-NDAN control brains. We chose this approach because NDAN individuals display AD-like amyloid pathology yet have preserved cognitive function, whereas AD brain tissue represents human subjects with both amyloid-pathology and cognitive impairment. While AD subjects showed reduced levels of the NAD+- synthesizing enzymes glutamine-dependent NAD+synthetase (NADSYN1) and nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2), levels of these enzymes were unchanged from control in NDAN subjects (Fig.5T). We additionally detected a trend of decreased expression in AD of the NAD+-synthesizing enzyme nicotinamide riboside kinase 1 (NMRK1), which did not change from control in NDAN (Fig.11G). With respect to NAD+-consuming enzymes, we detected increased NAD kinase 2 (NADK2), poly (ADP-ribose) polymerase 4 (PARP4), and sirtuin 1 (SIRT1) in AD, withlevels unchanged from control in NDAN . There was also a trend of increased expression of the NAD+-consuming enzymes 5'-nucleotidase cytosolic II (NT5C2) and sirtuin 4 (SIRT4) in AD, with no change in NDAN (Fig.11G). Thus, these findings reveal a dysregulation of NAD+metabolism in the AD brain. Restoration of NAD+homeostasis and recovery from BBB disruption, oxidative damage, and cognitive impairment in advanced-disease tau-driven mice by P7C3-A20

[0221] To determine whether restoration of NAD+homeostasis could also reverse AD- like disease in an alternative animal model, we tested the efficacy of P7C3-A20 in the PS19 mouse model of AD- like tauopathy. Rather than exhibiting amyloid pathology, PS19 mice express the P301S mutant form of human tau driven by the mouse prion protein promoter, with expression levels of mutant human tau being 5-fold higher than endogenous mouse tau. Over time, hyperphosphorylated and insoluble mutant human tau in these mice accumulates in intracellular tangles that closely resemble neurofibrillary tangles in human AD. These mice experience cognitive impairment and neurodegeneration, with an average lifespan of only twelve months.

[0222] We assessed the therapeutic efficacy of P7C3-A20 at a critical terminal stage of PS19 mice by initiating treatment when the mice reached eleven months of age, very close to the end of their lifespan (Fig.11H). At this age, PS19 mice demonstrated significantly impaired cognition, as indicated by a reduced discrimination index in the NOR test (Fig.11I). Mice were then randomly assigned to two groups: one to receive vehicle and the other to receive P7C3-A20. Although there was no statistically significant difference between the groups in performance in the NOR test before the initiation of treatment, those in the P7C3- A20 treatment group exhibited a trend toward greater cognitive impairment compared to the vehicle group (Fig.11J).

[0223] Importantly, after fifteen days of treatment, the 11.5-month-old PS19 mice that had received P7C3-A20 began to show improvement in the NOR test, with no difference in discrimination index between PS19 P7C3-A20 mice and WT VEH mice. However, there was still no significant improvement in discrimination index between PS19 P7C3-A20 mice and PS19 Vehicle mice at this stage (Fig.11K). After an additional fifteen days of treatment, however, the twelve-month-old PS19 mice that received P7C3-A20 showed significantly higher discrimination index compared to the PS19 mice receiving vehicle (Fig.11L).

[0224] Importantly, NAD+normalized in PS19 mice treated with P7C3-A20 (Fig.11M). Furthermore, P7C3-A20 treatment also normalized ZO-1 expression (Fig.11N), reversed protein carbonylation (Fig.11O), and showed a favorable trend toward reduced IBA-1 levels (Fig.11P). These aspects of disease reversal in PS19 mice occurred without altering mutant tau expression (Fig.11Q).

[0225] Thus, akin to the reversal of disease in amyloid-driven 5xFAD mice that was achieved without affecting underlying driving Aβ pathology, P7C3-A20 treatment also reversed disease in mutant human tau-driven PS19 mice without impacting their genetically- driven tau pathology. The finding that restoring brain NAD+homeostasis with P7C3-A20 can reverse AD-like disease across distinct animal models without interfering with their different genetic drivers of the disease indicates that brain resilience can be bolstered to foster disease recovery, even in very late stages of disease. Proteomic signatures from the brain of P7C3-A20-mediated AD reversal

[0226] In exploring the concept of AD reversal, we aimed to identify additional downstream molecular events specifically tied to this phenomenon. Thus, we undertook an unbiased label-free proteomic analysis of the hippocampi from 12-month-old male and female 5xFAD mice that had been treated daily with either VEH or P7C3-20 from 6 to 12 months of age. This analysis identified a total of 4,483 proteins in the female brain and 4,324 proteins in the male brain. All results are publicly accessible in the Data file, which represents the first established proteomics database for AD reversal. For this study, we defined DEPs as significant if they exhibited a fold change of ≥ ±1.25 and a p-value of ≤ 0.05. Other researchers accessing the freely available Data file can invoke alternative criteria for their analysis to address additional hypotheses.

[0227] Fig.6 presents the combined results for both female and male mice, while Figs.12 and 13 display individual results for females and males, respectively. The DEPs were categorized into three groups: (1) comparison of 5xFAD-VEH mice to WT-VEH mice, in which red indicates upregulated proteins in 5xFAD-VEH mice and blue denotes downregulated proteins in 5xFAD-VEH mice (Figs.6A, 12A, and 13A), (2) comparison of 5xFAD-P7C3-A20 mice to 5xFAD-VEH mice, in which red indicates upregulated proteins in 5xFAD-P7C3-A20 mice and blue denotes downregulated proteins in 5xFAD-P7C3-A20 mice (Figs.6B, 12B, and 13B), and (3) comparison of WT-P7C3-A20 mice to WT-VEH mice, inwhich red indicates proteins upregulated in P7C3A20 mice and blue denotes proteins downregulated in WT-P7C3-A20 mice (Figs.6C, 12C and 13C).

[0228] Among the significantly altered proteins in 5xFAD mice as compared to WT mice (group 1), we identified 174 DEPs (107 in females and 67 in males) that were absent in the 5xFAD mice treated with P7C3-A20 (group 2) (Figs.12D and 13D). This observation suggests that the aberrant expression levels of these proteins in symptomatic 5xFAD mice was normalized following P7C3-A20-mediated restoration of brain NAD+homeostasis.

[0229] Given that these 174 DEPs indicate brain pathways and potential therapeutic targets may be associated with AD reversal, we examined them closely by gene ontology (GO) and pathway analyses. The combined enrichment analysis of GO terms for all 174 DEPs is presented in Fig.6D, while individual results for females and males are shown in Figs.12E and 13E, respectively. When females and males were combined, GO term analysis of the 174 DEPs for “Biological Processes” pathways that were most significantly upregulated in 5xFAD mice and normalized by disease reversal included: cytoplasmic translation, glutamate receptor signaling pathway, ionotropic glutamate receptor signaling pathway, translation, and peptide biosynthetic process. The GO “Biological Processes” pathways that were most significantly downregulated in 5xFAD mice and normalized by disease reversal included: neurofilament bundle assembly, intermediate filament bundle assembly, cytoskeleton organization, supramolecular fiber organization, and postsynaptic intermediate filament cytoskeleton organization (Fig.6D).

[0230] GO term analysis of “Cellular Components” pathways for these 174 DEPs revealed that the most significantly upregulated pathways in 5xFAD mice that were normalized by disease reversal included: synapse, cytosolic ribosome, neuron to neuron synapse, cytosolic large ribosomal subunit, and postsynaptic density. GO term analysis of “Cellular Components” pathways that were most significantly downregulated in 5xFAD mice and normalized by disease reversal included: supramolecular polymer, myelin sheath, neurofilament, axon, and mitochondrion (Fig.6D).

[0231] GO term analysis of “Molecular Functions” pathways for these 174 DEPs showed that the most significantly upregulated pathways in 5xFAD mice that were normalized by disease reversal included: structural constituent of ribosome, glutamate receptor activity, ionotropic glutamate receptor activity, protein-containing complex binding, and structural molecule activity (UP). GO term analysis of “Molecular Functions” pathwaysthat were most significantly downregulated mice and restored to normal by disease reversal included: structural constituent of postsynaptic intermediate filament cytoskeleton, structural constituent of myelin sheath, calmodulin binding, cytoskeletal protein binding, and structural molecule activity (DOWN) (Fig.6D).

[0232] We next implemented Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, which emphasizes metabolic pathways across a wide range of species. The most significantly upregulated KEGG pathways in 5xFAD mice that were restored to normal by disease reversal included: pathways of neurodegeneration-multiple disease (UP), spinocerebellar ataxia, amyotrophic lateral sclerosis (UP), and Huntington disease. The most significantly downregulated KEGG pathways in 5xFAD mice that were restored to normal by disease reversal included: amyotrophic lateral sclerosis (DOWN), pathways of neurodegeneration-multiple diseases, and glucagon signaling pathway (Fig.6E). Notably, since P7C3-A20 has demonstrated significant protective effects in various preclinical models of neurodegeneration, these finding may provide insights into fundamental processes of neurodegeneration across diseases that are most sensitive to disrupted NAD+homeostasis.

[0233] We also employed Reactome pathway analysis, which focuses on detailed pathways in a specific species, in this case mice. The most significantly upregulated Reactome pathways in 5xFAD mice that were normalized by disease reversal included: nonsense mediated decay independent of the exon junction complex, SRP-dependent cotranslational protein targeting to membrane, formation of a pool of free 40S subunits, L13a-mediated translational silencing of ceruloplasmin expression, and eukaryotic translation initiation. The most significantly downregulated Reactome pathways in 5xFAD mice that were normalized by disease reversal through P7C3-A20 treatment included: potassium channels, cellular response to shear stress, TP53 regulated metabolic genes, neuronal system, and neurotransmitter receptors and postsynaptic signal transduction (Fig.6F).

[0234] While there was considerable overlap across male and female mice for the GO, KEGG, and Reactome analyses (Figs.12E-G and (Figs.7E-G, respectively), there were also unique representations. Given the ongoing interest in the field surrounding male vs. female trajectories of AD, this dataset provides a valuable resource for future studies. However, it is important to note that in our model we did not see differences in AD reversal between females and males. We cautiously suggest that these pathways may indicate varying vulnerabilities to disrupted NAD+- homeostasis in male and female 5xFAD brains, reflectingthe pathways most responsive to the of normal NAD+homeostasis, which could provide a basis for future investigation of this phenomenon in human AD. Proteins aberrantly expressed in both human and mouse AD and restored to normal levels in mice by AD reversal

[0235] To explore the clinical relevance of our findings, we next compared the 174 DEPs with available human AD brain proteomic databases. Our goal was to identify which of the aberrant genes in advanced-disease 5xFAD mice that were normalized by AD reversal were also aberrant in the same direction in human AD brains. We reasoned that these proteins could represent key pathways for understanding and potentially targeting human AD reversal.

[0236] For this investigation, we queried the composite analysis of 38 published human AD proteomic studies and found that 46 of the 174 mouse DEPs also changed in the same direction in the human AD brain (Fig.6G). Among these, 31 DEPs were present in female 5xFAD mice (Fig.12H) and 28 in male 5xFAD mice (Fig.13H). Fig.6H presents a heat map showing the NeuroPro score from the composite analysis, indicating that the proteins that were consistently elevated at specific AD stages have a positive score, while those that were consistently decreased compared to controls have a negative score.

[0237] Notably, Bcl-2 associated transcription factor 1 (BCLAF1), which triggers apoptotic cell death in the brain following injury, was elevated in both human and mouse AD but normalized with AD reversal. Elevated complement C1q subcomponent subunit A (C1QA) in human and mouse AD, linked to neuroinflammation and microglial-mediated synaptic loss in AD mice, was also normalized in mice by AD reversal.

[0238] We also identified several other proteins directly implicated in AD pathology. For example, amyloid precursor protein (APP), heterogeneous nuclear ribonucleoprotein U (HNRPU), and FMR2 autosomal homolog 1 (FXR1) were all elevated in both human and mouse AD and normalized in mice by AD reversal. HNRPU stabilizes the mRNA of beta- secretase 1 (BACE-1), the enzyme that initiates Aβ formation in AD, while FXR1 is involved in initiating BACE-1 translation. Furthermore, ubiquitin specific peptidase 10 (USP10), a deubiquitinase that contributes to early stress granule formation with tau pathology and interacts with sequestome 1 (SQSTM1 / p62) to form protective aggresomes, was decreased in both human and mouse AD and normalized in mice by AD reversal. In contrast,SQSTM1 / p62 levels showed the opposite and overabundance of this protein has been shown to delay the delivery of proteasomal substrates to the proteasome.

[0239] Another significant protein, prefoldin subunit 5 (PFDN5), decreased in both human and mouse AD and was normalized in mice by AD reversal. PFDN5, a component of the prefoldin molecular chaperone complex that stabilizes newly synthesized polypeptides for proper protein folding, has been shown to protect the brain from polyglutamine toxicity by preventing formation of pathological protein aggregates. It has also been shown to prevent toxic Aβ fibrillation, while aberrant PFDN5 is implicated in the progression from mild cognitive impairment to AD.

[0240] Various proteins associated with nucleic acid processing were similarly increased in human and mouse AD and normalized in mice by AD reversal. Examples include peptidylprolyl cis / trans isomerase NIMA-interacting 4 (PIN4), which is involved in chromatin remodeling and ribosome biogenesis, and the 60S ribosomal protein L7A (RPL7A), known to be pathologically elevated in brain capillaries in people with AD. Both PSMA6, which is a crucial subunit of the 20S proteome complex that is also a dysregulated hub gene in both blood and brain of human AD, and proteasome 26S subunit non-ATPase 3 (PSMD3), which is linked to apoptosis after brain injury, also displayed this same pattern.

[0241] Related to metabolism, glucose-6-phosphate isomerase 1 (GNPDA1) was elevated in human and mouse AD and normalized in mice by AD reversal. This enzyme catalyzes the conversion of D-glucosamine-6-phosphate into D-fructose-6-phosphate and ammonium, which is a critical step in the hexosamine pathway for producing uridine 5’diphosphate-N-acetylglucosamine (UDP-GlcNAC), a substrate for O-GlcNac transferase (OGT) involved in protein posttranslational modification. Disruption of this process in AD brains has been documented, and UDP-GlcNAc is essential for synthesizing hyaluronan, a key component of the extracellular matrix in the brain that regulates formation and maintenance of neural circuits, including the perineuronal nets (PNNs) that regulate synaptic plasticity. Importantly, PNNs show abnormal changes in various neurodegenerative diseases, including AD, where they are instrumental in processing Aβ and tau proteins.

[0242] In terms of fatty acid metabolism, ATP binding cassette subfamily D member 3 (ABCD3) levels were decreased in both human and mouse AD and normalized in mice by AD reversal. ABCD3 facilitates the beta-oxidation of fatty acids and fatty acyl-CoAs, transporting them from the cystosol into the peroxisome lumen. This transport process isaltered in both abundance and and neurodegenerative diseases, including AD.

[0243] Finally, proteins associated with mitochondrial functions were among those most significantly represented, with mitochondrial ribosomal protein S5 (MRPS5), Ts translation elongation factor mitochondrial (TSFM), fibronectin type 3 and SPRY domain- containing protein 1 (FSD1), AU RNA binding methylglutaconyl-CoA hydratase (AUH), and BolA like protein 1 (BOLA1) all exhibiting decreased expression levels in both human and mouse and AD and normalization in mice with AD reversal. MRPS5 plays a critical role in ensuring the translational accuracy of the mitoribosome, which is crucial for mitochondrial health. Indeed thirteen out of the 100 proteins that comprise the mitochondrial oxidative system are encoded by mitochondrial DNA and synthesized by the mitoribosome. MRPS5 deficiency leads to decreased mitochondrial oxygen consumption, reduced ATP generation, and increased ROS production. Correspondingly, TSFM is a mitochondrial translation elongation factor that is vital for mitochondrial complex 1 activity, with deficiencies linked to oxidative phosphorylation deficiency-3 syndrome. Additionally, FSD1 stabilizes microtubules and supports ciliogenesis, while AUH is a multifunctional mitochondrial protein that mediates critical steps in leucine degradation. Lastly, BOLA1 is integral to iron- sulfur cluster assembly in mitochondria, defects in which can lead to severe metabolic, hematological, and nervous system diseases, including AD.

[0244] Furthermore, many proteins associated with mitochondrial membrane structure were found to be decreased in both human and mouse AD and normalized in mice by AD reversal. Key examples include armadillo repeat-containing protein 1 (ARMC1), outer mitochondrial membrane lipid metabolism regulator (OPA3), solute carrier family 25 member 42 (SLC25A42), and protein tyrosine phosphatase localized to the mitochondrion 1 (PTPMT1). ARMC1 interacts with the outer mitochondrial membrane through its C- terminus and associates with the mitochondrial contact site and cristae organizing system (MICOS), playing a role in proper cellular distribution of mitochondria. OPA3, an inner mitochondrial membrane protein involved in energy regulation and apoptosis, has mutations associated with dominant optic neuropathy and Costeff syndrome. SLC25A42 is responsible for transporting coenzyme A (CoA) and adenosine 3’,5’-diphosphate across the mitochondrial inner membrane. Lastly, PTPMT1, anchored to the inner mitochondrial membrane with its phosphatase domain in the mitochondrial matrix, is essential for normalmitochondrial respiration, electron complex reduction, and maintenance of mitochondrial morphology through cardiolipin synthesis. Notably, aberrant levels of cardiolipin in the brain are linked to impaired neuronal function and neurodegeneration. GO term analysis of “Biological Processes” pathways of the 46 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: peptide biosynthetic process, translation, cellular amide metabolic process, organic substance catabolic process, and cellular catabolic process (Fig.6I). GO term analysis of “Biological Processes” pathways of the 46 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: protein localization to axon, cardiolipin biosynthetic process, phosphatidylglycerol biosynthetic process, cardiolipin metabolic process, and ATP transport (Fig.6I).

[0245] GO term analysis of “Cellular Components” pathways of the 46 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: ribonucleoprotein complex, postsynapse, nuclear lumen, cell junction, and synapse (Fig.6I). GO term analysis of “Cellular Components” pathways of the 46 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: mitochondrion, mitochondrial membrane, mitochondrial inner membrane, mitochondrial envelope, and organelle inner membrane (Fig.6I).

[0246] GO term analysis of “Molecular Functions” pathways of the 46 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: RNA binding, single-stranded RNA binding, mRNA binding, identical protein binding, and nucleic acid binding (Fig.6I). GO term analysis of “Molecular Functions” pathways of the 46 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: phatidylinositol-4,5- bisphosphate 5-phosphatase activity, hydrolase activity acting on ester bonds, phosphatase activity, hydrolase activity, and phosphoric ester hydrolase activity (Fig.6I). Sex-specific GO analyses are displayed in Figures S6J and S7J for females and males, respectively.

[0247] Reactome pathway analysis of the 46 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: signaling by ROBO receptors, signaling by interleukins, metabolism of RNA, cytokine signaling in immune system, and axon guidance (UP) (Fig.6J). Notably, Robo receptors play key roles in axon guidance, neurogenesis, and synaptic plasticity in the brain. Reactomepathway analysis of the 46 proteins that significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: translation, axon guidance (DOWN), nervous system development, membrane trafficking, and metabolism of proteins (Fig.6J). Sex-specific Reactome analyses are displayed in Figs.12K and 13K for females and males, respectively. Identification of differentially expressed proteins normalized by restoration of NAD+homeostasis that reflect transcriptional changes in the same direction

[0248] While proteomic signatures do not always correlate with transcriptional patterns, identifying instances where they do align can be informative. Such correlations suggest that the protein levels in question are likely primarily regulated at the transcriptional level in the context of the disease or treatment being studied. This insight can assist in developing potential biomarkers and guide the development of new therapies.

[0249] To explore this further, we investigated whether any altered proteins in the 5xFAD VEH mice, whose levels were normalized by disease reversal, also showed comparable mRNA changes in human AD brains. We queried the human transcriptome database for male and female middle temporal gyrus (MTG) and dorsolateral prefrontal cortex (DLPFC) from The Seattle Alzheimer’s Disease Brain Cell Atlas (SEA-AD) consortium and identified 17 of these proteins from males and females (Fig.6K). This included 11 proteins when examining females only (Fig.12L), and 6 proteins when examining males only (Fig.13L).

[0250] When considering males and females together, 7 of these 17 were upregulated in human and mouse AD: (BUB3 mitotic checkpoint protein (BUB3); DExH-box helicase 9 (DHX9); potassium channel tetramerization domain containing 12 (KCTD12), serine / threonine-protein kinase PAK 2 (PAK2), PEST proteolytic signal containing nuclear protein (PCNP), protein tyrosine kinase 2 beta (PTK2B), and ribosomal protein L7a (RPL7A). The remaining 10 proteins were downregulated in human and mouse AD: RAN binding protein 1 (RANBP1), amphiphysin (AMPH), ankyrin-3 (ANK3, also known as ankyrinG), contactin-associated protein 1 (CNTNAP1), cytochrome C oxidase subunit B1 (COX6B1), GDNF family receptor alpha 2 (GFRA2), leucyl-tRNA synthetase 2, mitochondrial (LARS2), Ras like without CAAX 2 (RIT2), secretory carrier membrane protein 5 (SCAMP5), and synaptosome associated protein 91 (SNAP91).

[0251] Notably, specific for some of these proteins have been previously proposed in AD and related processes. For example, DHX9 is critical in DNA and RNA biology in neurodegenerative disease and is also involved in hippocampal synaptic functioning. Elevated expression of PTK2B drives synaptic loss and promotes Aβ-induced microglial inflammation and tau pathology. RPL7A shows selective upregulation in brain capillaries (but not parenchyma) of AD patient brains. AMPH cleavage is linked to tau pathology and synaptic dysfunction in both human and mouse AD. Reduced ANK3 levels are associated with cognitive impairment and axon initial segment degradation in AD models. Levels of CNTNAP1 in the brain negatively correlate with levels of Aβ40 and Aβ42 APP fragments and are enriched at amyloid plaques in AD mice. LARS2 is responsible for pathological tau phosphorylation, hippocampal atrophy, and cognitive impairment in mice. Lastly, SCAMP5 is essential for maintaining proper endocytosis at active synapses.

[0252] We also repeated a focused pathway analysis on these 17 proteins. GO term analysis of “Biological Processes” pathways of these 17 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: peptide biosynthetic process, translation, amide biosynthetic process, peptide metabolic process, and cellular component biogenesis (Fig.6L). GO term analysis of “Biological Processes” pathways of these 17 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: endocytosis, vesicle- mediated transport, cellular localization, transport, and establishment of localization (Fig.6L).

[0253] GO term analysis of “Cellular Components” pathways of these 17 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: cell junction (UP), synapse (UP), presynapse (UP), anchoring junction, and synaptic membrane (Fig.6L). GO term analysis of “Cellular Components” pathways of these 17 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: synapse (DOWN), presynapse (DOWN), exocytic vesicle, synaptic vesicle, and cell junction (DOWN) (Fig.6L).

[0254] GO term analysis of “Cellular Components” pathways of these 17 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: cell junction (UP), synapse (UP), presynapse (UP), anchoring junction, and synaptic membrane (Fig.6L). GO term analysis of “Cellular Components” pathways of these17 proteins that were most significantly in human and mouse AD and normalized in mice by AD reversal included: synapse (DOWN), presynapse (DOWN), exocytic vesicle, synaptic vesicle, and cell junction (DOWN) (Fig.6L).

[0255] GO term analysis of “Molecular Functions” pathways of these 17 proteins that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: cadherin binding (UP), DNA / RNA helicase activity, cell adhesion molecule binding, structural constituent of ribosome, and RNA binding (Fig.6L). GO term analysis of “Molecular Functions” pathways of these 17 proteins that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: 1- phosphatidylinositol binding, GDP-dissociation inhibitor activity, cytochrome-c oxidase activity, aminoacyl-tRNA editing activity, and cadherin binding (DOWN) (Fig.6L).

[0256] Lastly, Reactome pathway analysis of these 17 proteins for pathways that were most significantly upregulated in human and mouse AD and normalized in mice by AD reversal included: axon guidance (UP), nervous system development (UP), developmental biology, translation, and signaling by ROBO receptors (Fig.6M). Reactome pathway analysis of these 17 proteins for pathways that were most significantly downregulated in human and mouse AD and normalized in mice by AD reversal included: clathrin-mediated endocytosis, axon guidance (DOWN), nervous system development (DOWN), membrane trafficking, and vesicle-mediated transport (Fig.6M).

[0257] AD is characterized by a prolonged preclinical phase in genetically predisposed individuals, suggesting a window of preserved neurologic resilience. Our study identifies dysregulation of NAD+homeostasis as a central mechanism underlying diminished resilience in both human and mouse AD brains. The extent of this dysregulation correlates directly with the progression of pathological and cognitive deterioration. Notably, NDAN individuals, who exhibit AD-like post-mortem pathology without clinical dementia, demonstrate the ability to maintain brain NAD+homeostasis, highlighting its critical role in shielding against neurodegeneration.

[0258] While aging naturally diminishes the quality of NAD+homeostasis, we observed significantly greater dysregulation in mouse and human AD brains compared to age-matched controls, suggesting that AD-specific mechanisms amplify this metabolic dysfunction, surpassing endogenous compensatory pathways. Supporting this, traumatic brain injury(TBI), a major environmental AD risk disrupts brain NAD+homeostasis, revealing a shared mechanistic pathway.

[0259] To evaluate the therapeutic potential of restoring NAD+homeostasis, we tested the pharmacologic agent P7C3-A20 in amyloid-(5xFAD) and tau-driven (PS19) AD mouse models. A prophylactic regimen of P7C3-A20 prevented disease onset in 5xFAD mice. Remarkably, initiating treatment at 6 months, when mice exhibit advanced pathology and cognitive deficits, led to complete restoration of brain health and function by 12 months, independent of amyloid burden. This, together with parallel recovery in symptomatic PS19 tau mice, provides the first experimental evidence of AD reversibility.

[0260] These findings challenge the long-standing belief that AD is irreversible, positioning NAD+-homeostasis restoration as a transformative therapeutic strategy capable of functional recovery rather than mere symptom mitigation. P7C3-A20 restored physiologic NAD+homeostasis in the brain without exceeding natural thresholds and also protected human brain microvascular endothelial cells from oxidative stress and mitochondrial dysfunction (a model of BBB deterioration in AD) in an NAD+-dependent manner.

[0261] Intriguingly, mid-disease 5xFAD mice display severe neuropsychiatric and cognitive deficits despite the absence of mature neuron loss. This implicates secondary pathologies, such as impaired proteostasis, BBB dysfunction, oxidative stress, neuroinflammation, and reduced neurogenesis, as key drivers of functional decline. While neuronal survival remains clinically relevant, our data reframe it as an indicator of progressive decline in brain health rather than as a prerequisite for cognitive impairment in AD. Ongoing studies will assess whether P7C3-A20 can also fully restore cognitive function following extensive neuronal cell loss in AD models, with the aspiration of extending our prior success in restoring cognitive function after irreversible neuronal cell loss post-TBI.

[0262] Beyond restoring brain NAD+homeostasis as a cornerstone of resilience, this approach unveils multifaceted opportunities for discovery related to the disease process and its treatment. Proteomic analysis in 5xFAD mice revealed that P7C3-A20 normalizes 46 proteins that are dysregulated in AD mouse brain and also dysregulated in the same direction in human AD brain (22 upregulated and 24 downregulated). Several of these proteins exhibit corresponding transcriptional changes as well. These proteins represent novel and potentially critical nodes in the human AD brain that may inform novel therapeutic strategies for reversing AD.

[0263] In summary, our work that pharmacologically re-establishing brain NAD+homeostasis restores brain resilience and reverses advanced AD pathology and cognitive impairment in preclinical models of AD. These findings challenge historical paradigms and establish a compelling scientific framework for developing therapies to prevent, halt, or reverse AD in humans.

[0264] From the above description of the invention, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes, and modifications within the skill of the art are intended to be covered by the appended claims. All references, publications, and patents cited in the present application are herein incorporated by reference in their entirety.

Claims

Having described the invention, we claim:

1. A method of restoring cognitive function and / or behavioral function in a subject having a cognitive or behavioral deficit associated with a neurodegenerative disorder, the method comprising: administering to the subject an amount of an aminopropyl carbazole compound effective to restore cognitive and / or behavioral function in the subject, wherein the aminopropyl carbazole compound normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

2. The method of the claim 1, wherein the aminopropyl carbazole compound comprises a compound of formula (I): or pharmaceutically acceptable salt thereof wherein:each of R1, R2, R4, R5, R7, and R8is independently selected from hydrogen, halo, hydroxyl, sulfhydryl, C1-C6 alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, C2-C6alkynyl, cyclopropyl, -N3, cyano, -NH2, - NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), and nitro; each of R3and R6is independently selected from fluoro, bromo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6 haloalkyl, C1-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, -NH(C1-C6 alkyl), - N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and nitro; each of L1and L2is, independently, C1-C3 alkylene, which is optionally substituted with from 1-2 independently selected Rc; A is:(i) CRA1RA2, wherein one and RA2is halo or OR9, wherein R9is hydrogen or C1-C3alkyl that is optionally substituted with hydroxyl or C1-C3alkoxy; and the other of RA1and RA2is hydrogen, halo, or C1-C3 alkyl; or (ii) C=O; Z is: -NR10R11; or -OR12; or -S(O)nR13, wherein n is 1, or 2; each of R10and R11is independently selected from: (a) hydrogen; (b) C6-C10aryl that is optionally substituted with from 1-4 Rb; (c) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; (d) C1-C6 alkyl or C1-C6 haloalkyl, each of which is optionally substituted with from 1-3 Rd; (e) -C(O)(C1-C6 alkyl), -C(O)(C1-C6 haloalkyl), or -C(O)O(C1-C6 alkyl); or (f) C2-C6 alkenyl or C2-C6 alkynyl; wherein one of R10and R11is selected from (b) or (c) and the other of R10and R11is selected from (a), (d), (e), or (f); R12is: (i) C6-C10 aryl that is optionally substituted with from 1-4 Rb; or (ii) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; R13is: C6-C10aryl that is optionally substituted with from 1-4 Rb; Rbat each occurrence is independently selected from the substituents delineated in (aa) through (dd) below: (aa) C1-C6 haloalkoxy; C1-C6 thioalkoxy; C1-C6 thiohaloalkoxy; -O-(CH2)1-3- [O(CH2)1-3]1-3-H; -NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, wherein the alkyl portion of each is unsubstituted or substituted with from 1-3 independently selected Re; (bb) hydroxyl; cyano; -NH2 ; azido; sulfhydryl; C2-C6 alkenyl; C2-C6 alkynyl; -C(O)H; -C(O)( C1-C6alkyl); -C(O)( C1-C6haloalkyl); -C(O)O(C1-C6alkyl); -C(O)NH2; - C(O)NH(C1-C6 alkyl);-C(O)N(C1-C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6alkyl)2;(cc) C3-C6 cycloalkyl or containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heterocyclyl is independently selected from N, NH, N(C1- C6 alkyl), NC(O)(C1-C6 alkyl), 0, and S; and (dd) phenyl or heteroaryl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heteroaryl is independently selected from N, NH, N(C1-C3 alkyl), O, and S; wherein each of said phenyl and heteroaryl is optionally substituted with from 1-3 substituents independently selected from halo; hydroxyl; cyano; nitro; -NH2; -NH(C1-C6 alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), C1-C6alkoxy; C1-C6haloalkoxy; C1-C6thioalkoxy; C1-C6 thiohaloalkoxy; C1-C6 alkyl, and C1-C6 haloalkyl; Rcat each occurrence is, independently selected from halo, C1-C6 alkoxy, C1- C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, -NH2, - NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and cyano; Rdat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, - NH2, NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and cyano; and Reat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy; C1-C6thioalkoxy; C1-C6haloalkoxy; C1-C6thiohaloalkoxy; -NH2; -NH(C1-C6alkyl); -N(C1- C6 alkyl)2; -NHC(O)( C1-C6 alkyl); cyano; -C(O)H; -C(O)(C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)OH; -C(O)O(C1-C6alkyl); -C(O)NH2; -C(O)NH(C1-C6alkyl); -C(O)N(C1- C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6 alkyl)2; and L3- (C1-C6alkylene)-biotin, wherein L3is a -O-, -NH-, -NCH3-, -C(O)-, -C(O)NH-, -C(O)NCH3-, - NHC(O)-, or -NCH3C(O)-.

3. The method of claim 1 or 2, wherein the subject, prior to administration of the aminopropyl carbazole compound, has a decline in brain NAD+ / NADH redox state associated with decreased NAD+level and increased NADH level.

4. The method of claim 3, wherein the decline in brain NAD+ / NADH redox state is at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, or at least about 75% compared to control normal or healthy subject.

5. The method of any of 4, wherein the amount of the aminopropyl carbazole compound administered is an amount effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) without abnormally elevating NAD+level.

6. The method of any of claims 1 to 5, wherein the neurodegenerative disorder is selected from subarachnoid hemorrhage, schizophrenia, major depression, bipolar disorder, epilepsy, traumatic brain injury and / or a visual symptom associated therewith, post-traumatic stress disorder, Parkinson’s disease, Parkinson Plus syndromes, Lewy Body Dementia, multiple system atrophy, corticobasal neurodegeneration, progressive supranuclear palsy, Alzheimer’s disease, Alzheimer's disease related dementias, Down syndrome, spinocerebellar ataxia, amyotrophic lateral sclerosis, Huntington’s disease, stroke, brain radiation therapy, chronic stress, abuse of a neuro-active drug, retinal degeneration, spinal cord injury, peripheral nerve injury, idiopathic peripheral neuropathy, cognitive decline and / or general frailty associated with normal aging and / or chemotherapy, chemotherapy induced neuropathy, concussive injury, peripheral nerve crush injury, peripheral neuropathy, diabetic neuropathy, post-traumatic headache, multiple sclerosis, retinal degeneration and dystrophy, Leber congenital amaurosis, retinitis pigmentosa, cone-rod dystrophy, microphthalmia, anophthalmia, myopia, and hyperopia, spinal cord injury, traumatic spinal cord injury, peripheral nerve injury, retinal neuronal death related diseases, retinal trauma, Autism, Stargardt disease, Kearns-Sayre syndrome, Pure neurosensory deafness, Hereditary hearing loss with retinal diseases, Hereditary hearing loss with system atrophies of the nervous system, Progressive spinal muscular atrophy, Progressive bulbar palsy, Primary lateral sclerosis, Hereditary forms of progressive muscular atrophy and spastic paraplegia, Frontotemporal dementia, Dementia with Lewy bodies, Corticobasal degeneration, Progressive supranuclear palsy, Prion disorders causing neurodegeneration, Multiple system atrophy, Hereditary spastic paraparesis, Friedreich ataxia, Non-Friedreich ataxia, Spinocerebellar atrophies, Amyloidoses, Metabolic-related neurodegenerative disorders, Toxin-related neurodegenerative disorders, Multiple sclerosis, Charcot Marie Tooth, Diabetic neuropathy, Metabolic neuropathies, Endocrine neuropathies, Creutzfeldt-Jacob Disease, Primary progressive aphasia, tauopathy, Frontotemporal Lobar Degeneration, Cortical blindness, Shy-Drager Syndrome, Diffuse cerebral cortical atrophy of non-Alzheimer type, Lewy-body dementia, Pick disease, Thalamic degeneration, Mesolimbocortical dementia ofnon-Alzheimer type, Nonhuntingtonian chorea and dementia, Cortical-striatal-spinal degeneration, Dementia-Parkinson-amyotrophic lateral sclerosis complex, Cerebrocerebellar degeneration, Cortico-basal ganglionic degeneration, Familial dementia with spastic paraparesis or myoclonus, Tourette syndrome, or viral infection.

7. The method of any of claims 1 to 6, wherein the neurodegenerative disorder is a tauopathy.

8. The method of any of claims 1 to 7, wherein the subject has been identified as having at least one of Alzheimer's disease, Lewy body dementia, Vascular dementia, Age- related dementia, Frontotemporal dementia, or mixed dementia.

9. The method of any of claims 1 to 8, wherein the neurodegenerative disorder is Alzheimer’s disease.

10. The method of any of claims 1 to 8, wherein the neurodegenerative disorder is not Alzheimer’s disease.

11. The method of any of claims 1 to 10, wherein the aminopropyl carbazole compound is 3,6-dibromo-3-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine (P7C3-A20) or a pharmaceutically acceptable salt thereof.

12. The method of any of claims 1 to 11, wherein the aminopropyl carbazole compound is administered chronically to the subject at an amount effective to maintain normalization of NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

13. The method of claim 12, wherein the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 300 mg / kg body weight per day.

14. The method of claim 12, the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 1000 mg per day.

15. The method of any of claims 1 to 14, further comprising measuring NAD+ / NADH redox state in the subject’s brain prior to administration of the aminopropyl carbazole compound and administering the aminopropyl carbazole compound if the subject has a decline in brain NAD+ / NADH redox state compared to a control.

16. A method of treating a tauopathy in a subject in need thereof, the method comprising: administering to the subject an amount of an aminopropyl carbazole compound effective to prevent cognitive and / or behavioral deficits and / or restore cognitive and / or behavioral function of the subject, wherein the aminopropyl carbazole compound normalizes NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

17. The method of claim 16, wherein the aminopropyl carbazole compound comprises a compound of formula (I): pharmaceutically acceptable salt thereof wherein:each of R1, R2, R4, R5, R7, and R8is independently selected from hydrogen, halo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, - NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), and nitro; each of R3and R6is independently selected from fluoro, bromo, hydroxyl, sulfhydryl, C1-C6alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6 haloalkyl, C1-C6 alkynyl, -N3, cyano, -NH2, -NH(C1-C6 alkyl), - N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and nitro; each of L1and L2is, independently, C1-C3 alkylene, which is optionally substituted with from 1-2 independently selected Rc; A is: (i) CRA1RA2, wherein one of RA1and RA2is halo or OR9, wherein R9is hydrogen or C1-C3 alkyl that is optionally substituted with hydroxyl or C1-C3 alkoxy; and the other of RA1and RA2is hydrogen, halo, or C1-C3alkyl; or (ii) C=O; Z is: -NR10R11; or -OR12; or -S(O)nR13, wherein n is 1, or 2; each of R10and R11is independently selected from: (a) hydrogen; (b) C6-C10 aryl that is optionally substituted with from 1-4 Rb; (c) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; (d) C1-C6 alkyl or C1-C6 haloalkyl, each of which is optionally substituted with from 1-3 Rd; (e) -C(O)(C1-C6 alkyl), -C(O)(C1-C6 haloalkyl), or -C(O)O(C1-C6 alkyl); or (f) C2-C6alkenyl or C2-C6alkynyl; wherein one of R10and R11is selected from (b) or (c) and the other of R10and R11is selected from (a), (d), (e), or (f); R12is: (i) C6-C10aryl that is optionally substituted with from 1-4 Rb; or (ii) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; R13is: C6-C10aryl that is optionally substituted with from 1-4 Rb; Rbat each occurrence is independently selected from the substituents delineated in (aa) through (dd) below: (aa) C1-C6 haloalkoxy; C1-C6 thioalkoxy; C1-C6 thiohaloalkoxy; -O-(CH2)1-3- [O(CH2)1-3]1-3-H; -NH(C1-C6alkyl), -N(C1-C6alkyl)2, wherein the alkyl portion of each is unsubstituted or substituted with from 1-3 independently selected Re;(bb) hydroxyl; cyano; - sulfhydryl; C2-C6 alkenyl; C2-C6 alkynyl; -C(O)H; -C(O)( C1-C6alkyl); -C(O)( C1-C6haloalkyl); -C(O)O(C1-C6alkyl); -C(O)NH2; - C(O)NH(C1-C6 alkyl);-C(O)N(C1-C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6alkyl)2; (cc) C3-C6 cycloalkyl or heterocyclyl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heterocyclyl is independently selected from N, NH, N(C1- C6 alkyl), NC(O)(C1-C6 alkyl), 0, and S; and (dd) phenyl or heteroaryl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heteroaryl is independently selected from N, NH, N(C1-C3 alkyl), O, and S; wherein each of said phenyl and heteroaryl is optionally substituted with from 1-3 substituents independently selected from halo; hydroxyl; cyano; nitro; -NH2; -NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)( C1-C6 alkyl), C1-C6 alkoxy; C1-C6 haloalkoxy; C1-C6 thioalkoxy; C1-C6 thiohaloalkoxy; C1-C6 alkyl, and C1-C6 haloalkyl; Rcat each occurrence is, independently selected from halo, C1-C6 alkoxy, C1- C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, -NH2, - NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and cyano; Rdat each occurrence is, independently selected from hydroxyl, C1-C6alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, - NH2, NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and cyano; and Reat each occurrence is, independently selected from hydroxyl, C1-C6 alkoxy; C1-C6thioalkoxy; C1-C6haloalkoxy; C1-C6thiohaloalkoxy; -NH2; -NH(C1-C6alkyl); -N(C1- C6 alkyl)2; -NHC(O)( C1-C6 alkyl); cyano; -C(O)H; -C(O)(C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)OH; -C(O)O(C1-C6alkyl); -C(O)NH2; -C(O)NH(C1-C6alkyl); -C(O)N(C1- C6 alkyl)2; -SO2(C1-C6 alkyl); -SO2NH2; -SO2NH(C1-C6 alkyl); -SO2N(C1-C6 alkyl)2; and L3- (C1-C6 alkylene)-biotin, wherein L3is a -O-, -NH-, -NCH3-, -C(O)-, -C(O)NH-, -C(O)NCH3-, - NHC(O)-, or -NCH3C(O)-.

18. The method of claim 16 or 17, wherein the subject, prior to administration of the aminopropyl carbazole compound, has a decline in brain NAD+ / NADH redox state associated with decreased NAD+level and increased NADH level.

19. The method of claim 18, the decline in brain NAD+ / NADH redox state is at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, or at least about 75% compared to control normal or healthy subject.

20. The method of claim 18 or 19, wherein the amount of the aminopropyl carbazole compound administered is an amount effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) without abnormally elevating NAD+level.

21. The method of any of claims 16 to 20, wherein the tauopathy is selected from Alzheimer's disease, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), Parkinson's discase, Pick's disease (PiD), primary progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler-Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle-predominant dementia, ganglioglioma, gangliocytoma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT).

22. The method of any of 21, wherein the tauopathy is not Alzheimer’s disease.

23. The method of any of claims 16 to 22, wherein the aminopropyl carbazole compound is 3,6-dibromo-3-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine (P7C3-A20) or a pharmaceutically acceptable salt thereof.

24. The method of any of claims 16 to 23, wherein the aminopropyl carbazole compound is administered chronically to the subject at an amount effective to maintain normalization of NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

25. The method of claim 24, wherein the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 300 mg / kg body weight per day.

26. The method of claim 24, wherein the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 1000 mg per day.

27. The method of any of claims 16 to 26, further comprising measuring NAD+ / NADH redox state in the subject’s brain prior to administration of the aminopropyl carbazole compound and administering the aminopropyl carbazole compound if the subject has a decline in brain NAD+ / NADH redox state compared to a control.

28. A method of inhibiting and / or reducing β-amyloid plaque accumulation and / or Tau phosphorylation in a subject in need thereof, the method comprising: administering to the subject an amount of an aminopropyl carbazole compound effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) and reduce β-amyloid plaque accumulation and / or Tau phosphorylation in the subject.

29. The method of claim 28, the aminopropyl carbazole compound comprises a compound of formula (I): wherein:halo, hydroxyl, sulfhydryl, C1-C6 alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkynyl, cyclopropyl, -N3, cyano, -NH2, - NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)( C1-C6 alkyl), and nitro; each of R3and R6is independently selected from fluoro, bromo, hydroxyl, sulfhydryl, C1-C6 alkoxy, C1-C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6haloalkyl, C1-C6alkynyl, cyclopropyl, -N3, cyano, -NH2, -NH(C1-C6alkyl), - N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and nitro; each of L1and L2is, independently, C1-C3alkylene, which is optionally substituted with from 1-2 independently selected Rc; A is: (i) CRA1RA2, wherein one of RA1and RA2is halo or OR9, wherein R9is hydrogen or C1-C3 alkyl that is optionally substituted with hydroxyl or C1-C3 alkoxy; and the other of RA1and RA2is hydrogen, halo, or C1-C3alkyl; or (ii) C=O; Z is: -NR10R11; or -OR12; or -S(O)nR13, wherein n is 1, or 2; each of R10and R11is independently selected from: (a) hydrogen; (b) C6-C10 aryl that is optionally substituted with from 1-4 Rb; (c) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb;(d) C1-C6 alkyl or C1-C6 each of which is optionally substituted with from 1-3 Rd; (e) -C(O)( C1-C6 alkyl), -C(O)( C1-C6 haloalkyl), or -C(O)O(C1-C6 alkyl); or (f) C2-C6alkenyl or C2-C6alkynyl; wherein one of R10and R11is selected from (b) or (c) and the other of R10and R11is selected from (a), (d), (e), or (f); R12is: (i) C6-C10aryl that is optionally substituted with from 1-4 Rb; or (ii) heteroaryl containing 6 ring atoms, wherein 1-2 of the ring atoms is N; and wherein said heteroaryl is optionally substituted with from 1-4 Rb; R13is: C6-C10 aryl that is optionally substituted with from 1-4 Rb; Rbat each occurrence is independently selected from the substituents delineated in (aa) through (dd) below: (aa) C1-C6 haloalkoxy; C1-C6 thioalkoxy; C1-C6 thiohaloalkoxy; -O-(CH2)1-3- [O(CH2)1-3]1-3-H; -NH(C1-C6alkyl), -N(C1-C6alkyl)2, wherein the alkyl portion of each is unsubstituted or substituted with from 1-3 independently selected Re; (bb) hydroxyl; cyano; -NH2; azido; sulfhydryl; C2-C6alkenyl; C2-C6alkynyl; -C(O)H; -C(O)( C1-C6 alkyl); -C(O)( C1-C6 haloalkyl); -C(O)O(C1-C6 alkyl); -C(O)NH2 ; - C(O)NH(C1-C6alkyl);-C(O)N(C1-C6alkyl)2; -SO2(C1-C6alkyl); -SO2NH2; -SO2NH(C1-C6alkyl); -SO2N(C1-C6 alkyl)2; (cc) C3-C6cycloalkyl or heterocyclyl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heterocyclyl is independently selected from N, NH, N(C1- C6alkyl), NC(O)(C1-C6alkyl), 0, and S; and (dd) phenyl or heteroaryl containing from 5-6 ring atoms, wherein from 1-2 of the ring atoms of the heteroaryl is independently selected from N, NH, N(C1-C3 alkyl), O, and S; wherein each of said phenyl and heteroaryl is optionally substituted with from 1-3 substituents independently selected from halo; hydroxyl; cyano; nitro; -NH2; -NH(C1-C6 alkyl), -N(C1-C6alkyl)2, -NHC(O)( C1-C6alkyl), C1-C6alkoxy; C1-C6haloalkoxy; C1-C6thioalkoxy; C1-C6 thiohaloalkoxy; C1-C6 alkyl, and C1-C6 haloalkyl; Rcat each occurrence is, independently selected from halo, C1-C6alkoxy, C1- C6 thioalkoxy, C1-C6 haloalkoxy, C1-C6 thiohaloalkoxy, C1-C6 alkyl, C1-C6 haloalkyl, -NH2, - NH(C1-C6alkyl), -N(C1-C6alkyl)2, -NHC(O)(C1-C6alkyl), and cyano;Rdat each occurrence is, selected from hydroxyl, C1-C6 alkoxy, C1-C6thioalkoxy, C1-C6haloalkoxy, C1-C6thiohaloalkoxy, C1-C6alkyl, C1-C6haloalkyl, - NH2, NH(C1-C6 alkyl), -N(C1-C6 alkyl)2, -NHC(O)(C1-C6 alkyl), and cyano; and Reat each occurrence is, independently selected from hydroxyl, C1-C6alkoxy; C1-C6 thioalkoxy; C1-C6 haloalkoxy; C1-C6 thiohaloalkoxy; -NH2; -NH(C1-C6 alkyl); -N(C1- C6alkyl)2; -NHC(O)( C1-C6alkyl); cyano; -C(O)H; -C(O)(C1-C6alkyl); -C(O)( C1-C6haloalkyl); -C(O)OH; -C(O)O(C1-C6 alkyl); -C(O)NH2; -C(O)NH(C1-C6 alkyl); -C(O)N(C1- C6alkyl)2; -SO2(C1-C6alkyl); -SO2NH2; -SO2NH(C1-C6alkyl); -SO2N(C1-C6alkyl)2; and L3- (C1-C6 alkylene)-biotin, wherein L3is a -O-, -NH-, -NCH3-, -C(O)-, -C(O)NH-, -C(O)NCH3-, -NHC(O)-, or -NCH3C(O)-.

30. The method of claim 28 or 29, wherein the subject, prior to administration of the aminopropyl carbazole compound, has a decline in brain NAD+ / NADH redox state associated with decreased NAD+level and increased NADH level.

31. The method of claim 30, wherein the decline in brain NAD+ / NADH redox state is at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, or at least about 75% compared to control normal or healthy subject.

32. The method of claim 30 or 31, wherein the amount of the aminopropyl carbazole compound administered is an amount effective to normalize brain NAD+homeostasis (or NAD+ / NADH redox state) without abnormally elevating NAD+level.

33. The method of any of claims 28 to 32, wherein the subject has or is at increased risk of a tauopathy.

34. The method of claim 33, wherein the tauopathy is selected from Alzheimer's disease, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), behavioral variant frontotemporal dementia (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA),Parkinson's discase, Pick's disease (PiD), progressive aphasia-semantic (PPA-S), primary progressive aphasia-logopenic (PPA-L), multiple system tauopathy with presenile dementia (MSTD), neurofibrillary tangle (NFT) dementia, FTD with motor neuron disease, progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis / parkinsonism-dementia complex (ALS-PDC), argyrophilic grain dementia (AGD), British type amyloid angiopathy, cerebral amyloid angiopathy, chronic traumatic encephalopathy (CTE), corticobasal degeneration (CBD), Creutzfeldt-Jakob disease (CJD), dementia pugilistica, diffuse neurofibrillary tangles with calcification, Down's syndrome, epilepsy, Gerstmann-Straussler- Scheinker disease, Hallervorden-Spatz disease, Huntington's disease, inclusion body myositis, lead encephalopathy, Lytico-Bodig disease, meningioangiomatosis, multiple system atrophy, myotonic dystrophy, Niemann-Pick disease type C (NP-C), non-Guamanian motor neuron disease with neurofibrillary tangles, postencephalitic parkinsonism, prion protein cerebral amyloid angiopathy, progressive subcortical gliosis, tangle only dementia, tangle- predominant dementia, ganglioglioma, gangliocytoma, subacute sclerosingpan encephalitis, tuberous sclerosis, lipofuscinosis, primary age-related tauopathy (PART), or globular glial tauopathies (GGT).

35. The method of claim 34, wherein the tauopathy is not Alzheimer’s disease.

36. The method of any of claims 28 to 35, wherein the aminopropyl carbazole compound is 3,6-dibromo-3-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine (P7C3-A20) or a pharmaceutically acceptable salt thereof.

37. The method of any of claims 28 to 36, wherein the aminopropyl carbazole compound is administered chronically to the subject at an amount effective to maintain normalization of NAD+homeostasis (or NAD+ / NADH redox state) in the subject’s brain without abnormally elevating NAD+level.

38. The method of claim 37, wherein the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 300 mg / kg body weight per day.

39. The method of claim 37, the aminopropyl carbazole compound is chronically administered to the subject at a dose of about 0.01 to about 1000 mg per day.

40. The method of any of claims 28 to 39, further comprising measuring NAD+ / NADH redox state in the subject’s brain prior to administration of the aminopropyl carbazole compound and administering the aminopropyl carbazole compound if the subject has a decline in brain NAD+ / NADH redox state compared to a control.

41. The use of an aminopropyl carbazole compound having formula (I) in the preparation of a medicament for use in the methods of any of claims 1 to 40.

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