Therapeutic agent for neurological diseases

Abstract

In nerve diseases, cell dysfunction due to amyloid aggregate accumulation in nerve cells has attracted attention, but dysfunction of nerve axons responsible for neurotransmission is also considered to be one of the causes. However, no therapeutic agent that focuses on the repair and maintenance of nerve axons has been found. An object of the present invention is to provide a therapeutic agent that activates oligodendrocytes having a function of preserving nerve axons.SOLUTION: Transcriptome analysis with a psychotropic drug is carried out using an oligodendrocyte marker as an indicator, and it is found that the combined use of DPZ and NFN characteristically increases the expression of a transcriptional factor OLIG1 inducing the differentiation-maturation of the oligodendrocyte. Moreover, the drug concentration at this time was much lower than the expected clinical dose. The combined use of NFN and DPZ was observed to improve spatial memory in the mouse Y-maze test. The combination of NFN and DPZ can provide a novel treatment for cognitive and memory functions associated with neurological disorders.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a therapeutic agent for neurological diseases that activates oligodendrocytes by enhancing the expression of oligodendrocyte transcription factor 1 (OLIG1). [Background technology]

[0002] As many countries around the world face aging societies, the need for treatments for neurological disorders is increasing. While several hypotheses suggest that neurological disorders are caused by genetic dysfunction or the accumulation of intracellular aggregates, many of these theories remain unclear. The central nervous system (brain and spinal cord) is composed of nerve cells (neurons) and glial cells (astrocytes, oligodendrocytes, and microglia), while the peripheral nervous system is composed of nerve cells (neurons) and Schwann cells, which correspond to oligodendrocytes, and these cells share commonalities. While traditionally, attention has focused on neurons as a cell type involved in disease, recent evidence has revealed that glial cells also play a significant role in disease progression (Non-Patent Document 1). From a disease pathology perspective, intracellular amyloid aggregates, such as Aβ, phosphorylated tau, and α-synuclein, are therapeutic targets. However, given that cognitive and motor functions are controlled by neurotransmission, repairing glial cell-mediated neurotransmission disorders, in addition to aggregates, is also considered an important therapeutic target.

[0003] Oligodendrocytes are responsible for myelin formation, which coats nerve axons and increases the conduction velocity of electrical signals. Brain pathology in Alzheimer's disease (AD) has revealed that axon loss and demyelination are associated with cerebral white matter abnormalities (Non-Patent Document 2). Impaired oligodendrocyte function and myelination are thought to be potential therapeutic targets for neurological disorders such as AD, schizophrenia, and multiple sclerosis (MS) (Non-Patent Document 3). However, currently, the only axon-focused treatments available are those that block the infiltration of myelin antigen-specific autoreactive T cells in MS.

[0004] Technologies related to oligodendrocytes include a method for enhancing oligodendrocyte function using Helicin erinaceus mycelium extract to treat diseases of demyelination or myelin sheath damage (Patent Document 1), and a system for diagnosing central nervous system diseases from biomarkers such as oligodendrocyte-related factors in peripheral body fluids (Patent Document 2).

[0005] In the future, if cognitive and memory impairments in neurological diseases are viewed as axonal dysfunction, therapeutic mechanisms mediated by the activation of oligodendrocytes may become new therapeutic drugs for neurological diseases. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent application No. 2020-12561 [Patent Document 2] Patent application No. 2022-568816 [Patent Document 3] Patent application No. 2023-131174 [Patent Document 4] Patent application No. 2018-515123 [Non-patent literature]

[0007] [Non-Patent Document 1] Sadick et al., Neuron. 2022; 110(11): 1788-1805.e10. doi: 10.1016 / j.neuron.2022.03.008. [Non-patent document 2] Nasrabady SE, et al.,Acta Neuropathol Commun. 2018 Mar 2;6(1):22. doi: 10.1186 / s40478-018-0515-3. [Non-patent document 3] Kuhnet al., Cells. 2019 12;8(11):1424. doi: 10.3390 / cells8111424. [Non-patent document 4] Takizawa et al., Biomed Pharmacother.2022:146:112593. doi: 10.1016 / j.biopha.2021.112593. [Non-patent document 5] Bajpai et al., Stem Cells. 2017 May;35(5):1402-1415. doi: 10.1002 / stem.2583. [Non-patent document 6] Varadharajan et al., J Neurosci Rural Pract.2023; 14(4): 566-573. doi:10.25259 / JNRP_356_2023. [Non-Patent Document 7] Calsolaro et al.,Pharmaceuticals 2021, 14(3), 246. doi.org / 10.3390 / ph14030246. Summary of the Invention [Problem to be solved by the invention]

[0008] The formation and maintenance of axons is essential for maintaining cognitive and motor functions and can be a therapeutic target for neurological diseases. However, there are no drugs that treat cognitive and memory disorders in neurological diseases through the activation of oligodendrocytes, which are thought to be axonal dysfunction. Therefore, the search for compounds that induce oligodendrocyte activation to restore and maintain axonal function in neurological diseases is a challenge. [Means for solving the problem]

[0009] The present disclosure relates to an agent for enhancing the expression of oligodendrocyte transcription factor 1 (OLGI1), which induces the generation and maturation of oligodendrocytes, for the activation of oligodendrocytes to improve cognitive dysfunction and memory impairment in neurological diseases. (Section 1) An oligodendrocyte transcription factor 1 (OLIG1) expression enhancer containing a combination or combination of donepezil and a kappa opioid agonist as active ingredients. (Section 2) The OLIG1 expression enhancer according to (Item 1), wherein the kappa opioid agonist is nalfurafine. (Section 3) An OLIG1 expression enhancer in which either or both of donepezil and nalfurafine are administered in a dose lower than the clinical dose range of each drug alone when used in combination or in combination (Item 2). (Section 4) 1. An agent for enhancing OLIG1 expression, wherein the enhancement of OLIG1 expression is intended to repair and preserve axons in neurological diseases by activating oligodendrocytes, and is used to treat a disease selected from Alzheimer's disease (AD, vascular dementia (VD), frontotemporal dementia (FTD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), Parkinson's disease (PD), Huntington's disease (HD), Sydenham's chorea, hepatolenticular degeneration (WD), multiple system atrophy (MSA), spinocerebellar degeneration (SCD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), multiple sclerosis (MS), neuromyelitis optica (NMO), and leukodystrophy (Item 1). [Effects of the Invention]

[0010] The present disclosure makes it possible to provide a therapeutic agent that is useful for improving and maintaining cognitive and motor functions by activating oligodendrocytes in neurological diseases and repairing and preserving nerve axons. [Brief explanation of the drawings]

[0011] [Figure 1]This figure shows the induction of oligodendrocyte marker gene expression in human keratinocytes by eight compounds. The horizontal axis represents the drug, and the vertical axis represents the expression ratio (LOG2 value). The compounds are as follows: SPM; escitalopram, DXN; duloxetine, PGN; pregabalin, APZ; aripiprazole, MZP; mirtazapine, DPZ; donepezil, NFN; nalfurafine, DKN; and difelikefalin. None of the drugs alone was observed to induce strong marker gene expression. [Figure 2] Induction of oligodendrocyte marker gene expression in human keratinocytes by NFN+DPZ (combined use of nalfurafine and donepezil). The horizontal axis shows the drugs, and the vertical axis shows the expression ratio (LOG2 value). OLIG1 expression was significantly increased. [Figure 3] Gene expression of the acetylcholine synthesis system and cholinergic receptor system (A) and the GABA (gamma-aminobutyric acid) synthesis system and GABA receptor system (B) in human keratinocytes under the conditions of NFN, DPZ, and NFN+DPZ. The acetylcholine system contributes to nerve excitation, and the GABA system contributes to nerve inhibition. In the case of NFN+DPZ, gene expression of NFN and DPZ is maintained, and it is expected that the pharmacological actions of the individual drugs will be maintained. At the same time, there was a tendency for them to synchronize with NFN gene expression, suggesting the induction of complex biological actions. [Figure 4] Responsiveness to NFN administration in the mouse Y-maze test. Spatial recognition memory is evaluated by calculating the rate of spontaneous alternation behavior (%) from the number of times (alternations) the mice entered different arms to search for food in a Y-maze. At high doses, NFN reduced the total number of entries (total arm entries), demonstrating behavioral suppression (sedative effect). The no-effect dose for this test system was set at 0.1 μg / kg, based on the dose range that did not cause behavioral suppression in total entries. [Figure 5]Responsiveness to DPZ administration in cognitive impairment model mice. A Y-maze test was performed on cognitive impairment model mice administered the muscarinic receptor antagonist scopolamine (1.0 mg / kg, ip). The no-effect dose of DPZ, which did not cause any behavioral changes in the spontaneous alternation rate (%) or total number of entries, was determined to be 1.0 mg / kg. [Figure 6] Responsiveness to NFN + DPZ administration in cognitive impairment model mice. At the no-effect dose of NFN (0.1 μg / kg, sc) and DPZ (1.0 mg / kg, ip), a significant increase in spontaneous alternation rate (%) was observed under the NFN + DPZ condition. However, there was no significant effect on the total number of entries. Therefore, even at a no-effect dose when used alone, the combination of NFN and DPZ significantly enhanced the improvement of spatial recognition memory. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will now be described. Terms used in this specification have the meanings commonly used in the art unless otherwise specified. [Identification of oligodendrocyte markers] In this study, we searched for compounds that activate oligodendrocytes to perform axonal regeneration, repair, and maintenance. To this end, we extracted genes as markers for oligodendrocytes and their precursor cells. Some of these genes have been reported in related papers. For example, genes (symbol, HGNC ID number, gene name) listed in Non-Patent Document 3 include PDGFRA (HGNC:8803 NCBI Gene:5156, platelet-derived growth factor receptor alpha), CSPG4 (HGNC:2466 NCBI Gene:1464, chondroitin sulfate protein oligodendrocyte lycan 4), OLIG1 (HGNC:16983 NCBI Gene:116448, oligodendrocyte transcription factor 1), OLIG2 (HGNC:9398 NCBI Gene:10215, oligodendrocyte lineage transcription factor 2), SOX10 (HGNC:11190 NCBI Gene:6663, SRY-box 10), PLP1 (HGNC:9086 NCBI Gene:5354, proteolipid protein 1), and MBP (HGNC:6925 Representative examples include a group of nine genes, including MOBP (HGNC:7189 NCBI Gene:4336, myelin-associated oligodendrocyte basic protein), and M oligodendrocyte (HGNC:7197 NCBI Gene:4340, myelin oligodendrocyte glycoprotein). The transcription factors OLIG1 and OLIG2 are particularly important as they control the differentiation and maturation of oligodendrocytes.

[0013] [Selection of compounds that activate oligodendrocytes] It has been reported that neural crest cells and neural crest-derived cells, which are the origin of peripheral neurogenesis, differentiate into keratinocytes (Non-Patent Document 4), and conversely, keratinocytes can be reprogrammed into neural crest cells (Non-Patent Document 5).Keratinocytes are known to possess the properties and functions of nervous system cells.On the other hand, psychotropic drugs that have the ability to cross the blood-brain barrier are worth evaluating for their new pharmacological effects on oligodendrocytes.

[0014] Based on these findings, we performed transcriptome analysis of human keratinocytes to identify compounds that modify oligodendrocyte function. We evaluated eight psychotropic compounds: SPM; escitalopram (Dextron, DXN); duloxetine (PGN); pregabalin (APZ); aripiprazole (MZP); mirtazapine (DPZ); donepezil (NFN); nalfurafine (DKN); and difelikefalin.

[0015] As a result, none of these eight compounds were found to enhance the expression of oligodendrocyte markers. Therefore, because DPZ, which has cognitive function-improving properties, and NFN (Patent Document 3), which the inventors have found to have a similar effect, have different mechanisms of action, we anticipated a synergistic effect. Therefore, we selected NFN and DPZ and attempted a combination of the two (NFN + DPZ). As a result, we found that NFN + DPZ characteristically and strongly amplified the oligodendrocyte transcription factor OLIG1 (Figure 2). Since DPZ and NFN each tend to suppress OLIG1 expression alone (Figure 1), it was intriguing that their combined use enhanced expression. These findings suggest that NFN + DPZ strongly activates oligodendrocytes and contributes to neurotransmission through the preservation of axons.

[0016] [Possible gene expression of NFN and DPZ] DPZ is an acetylcholinesterase inhibitor and is expected to have a positive effect on the gene expression of the acetylcholine synthesis system and cholinergic receptors. On the other hand, NFN is a kappa opioid agonist and is expected to have a negative effect on the GABA synthesis system and GABA receptor system. When this was examined by transcriptome analysis, as shown in Figure 3, DPZ tended to enhance the cholinergic system, while NFN tended to inhibit the GABA system. In the case of NFN + DPZ, the gene expression of NFN and DPZ alone was maintained, but tended to synchronize with that of NFN.

[0017] We analyzed biological processes using the enrichment analysis tool Metascape for the top 300 genes expressed under each condition: NFN, DPZ, and NFN+DPZ. As shown in Table 1, NFN+DPZ induced more neural events than either NFN or DPZ alone, suggesting that in addition to the individual effects of NFN and DPZ, a synergistic effect of activating intracellular events occurred. This is consistent with the activation of oligodendrocytes by the combined use of NFN+DPZ, which enhances neurotransmission events. OLIG1 expression is included in GO:0031175 (Biological Process: Neuronal Projection Development), suggesting that a synergistic effect of oligodendrocyte activation enhances neurotransmission.

[0018] [Table 1]

[0019] [Animal pharmacological evaluation of NFN+DPZ] The synergistic effects of NFN+DPZ were investigated in a behavioral pharmacology test in mice. It was predicted that the cognitive improvement effects of DPZ would be enhanced if NFN+DPZ activated oligodendrocytes, preserved axons, and stabilized neurotransmission. Therefore, spatial memory function was evaluated in mice modeled after scopolamine (1.0 mg / kg, i.p.), a muscarinic receptor antagonist, using the Y-maze test, where the number of times mice entered different arms to search for food (spontaneous alternation rate) was used as an index.

[0020] In general, the important advantage of combination drugs is that they enhance efficacy while reducing the dose of each single drug, thereby reducing side effects. Therefore, we investigated low doses at which the pharmacological effects of each drug are not manifested (equivalent to the clinical no-effect dose), and set the no-effect dose for NFN at 0.1 μg / kg (Figure 4) and for DPZ at 1.0 mg / kg (Figure 5). The no-effect dose for NFN is equivalent to 1 / 100 of the pharmacological dose in mice (10 μg / kg administered to mice to suppress itch).

[0021] Although NFN + DPZ had no significant effect on the total number of entries within the no-effect dose range of both drugs, it significantly increased the rate of spontaneous alternation behavior (%) (Fig. 6). This indicates that NFN significantly enhanced the effect of DPZ on improving spatial recognition memory in a mouse model of scopolamine-induced cognitive impairment.

[0022] [Development of combination or fixed-dose NFN+DPZ drugs] Dosage forms for the combined use or fixed dose of NFN+DPZ include tablets, capsules, orally disintegrating tablets, powders, or granules, while parenteral administration includes rapid intravenous infusion, continuous intravenous infusion, intramuscular injection, subcutaneous injection, intradermal injection, inhalants, suppositories, ointments, creams, and patches. For patients with neurological disorders taking multiple medications, dosage forms that are minimally invasive, allow monitoring of the administration status, and are highly convenient are preferred. Patches (tissue patches) are particularly preferred for patients with neurological disorders because the dosage can be adjusted by the number of patches applied and they can be used by elderly people with swallowing disorders.

[0023] The dose of NFN and DPZ used in combination to improve spatial cognitive memory, as discovered in this study, is lower than the standard clinical dose of either drug alone, which can contribute to reducing side effects. DPZ is widely used as an anti-dementia drug for AD, but it frequently causes gastrointestinal symptoms (loss of appetite, nausea, vomiting, diarrhea, etc.) and cardiac side effects, resulting in a discontinuation rate of approximately 10% (Non-Patent Document 6). Because these adverse events have an undesirable impact on patients' quality of life, some measures to mitigate side effects are needed.

[0024] According to the present invention, DPZ and NFN have been shown to improve spatial cognitive memory at lower doses (no-effect doses in this test evaluation system) than the pharmacologically effective doses used in conventional clinical trials. Generally, when considering combination drugs or drug combinations, the clinical doses of the approved single drugs are assumed, and synergistic effects at low doses of 1 / 10 or 1 / 100, as disclosed herein, are not specifically anticipated. The use of NFN for AD dementia is also disclosed in Patent Document 4, but this is merely a list of common compounds, and the low-dose use in the present invention cannot be inferred from it. The present invention relates to a particularly preferred dosage and administration method for the combined use of NFN and DPZ.

[0025] The preferred clinical doses for humans are 0.3 to 5 mg once daily for DPZ (equivalent to 1 / 10 to 1 / 2 of the approved dose of 3 mg to 10 mg), and 0.025 μg to 0.5 μg once daily for NFN (equivalent to 1 / 100 to 1 / 10 of the approved dose of 2.5 μg or 5 μg).

[0026] NFN is a kappa opioid agonist (KOR agonist), and its congener, difelikefalin (DKN, CR845), can also be used in combination with DPZ or as a combined drug. [Example]

[0027] [Gene expression analysis in human keratinocytes] Neural crest cells, which are the origin of peripheral neurogenesis, differentiate into neurons and Schwann cells and are preserved as neural crest-derived cells even in adulthood, promoting the repair of nervous tissue after injury or stress. It is known that neural crest-derived cells differentiate into keratinocytes (Non-Patent Document 4), and conversely, keratinocytes can be reprogrammed into neural crest cells (Non-Patent Document 5). This indicates that keratinocytes possess the properties and functions of nervous system cells, and it is expected that keratinocytes will also respond to drugs in a manner similar to that of nervous system cells.

[0028] On the other hand, psychotropic drugs are also used to treat behavioral and psychological symptoms of dementia (BPSD), such as agitation, aggression, delusions, and hallucinations (Non-Patent Document 7). Therefore, psychotropic drugs that can cross the blood-brain barrier may be selected from the perspective of drug delivery. However, their pharmacological effects on oligodendrocytes are unknown and are worth evaluating.

[0029] Based on the above, the present inventors evaluated compounds that modify oligodendrocyte function by transcriptome analysis of human keratinocytes. Normal human-derived epidermal keratinocytes (NHEK-Ad, Lonza) were cultured at 2 × 10 in serum-free cell culture medium (KGM-Gold™ Bullet Kit, Lonza). 5 1.8 mL of drug treatment medium was added to the culture medium. 200 μL of each test substance at 10x the final concentration was added to the culture medium. The cells were cultured overnight in a CO2 incubator (37°C, 5% CO2). Drug treatment (each drug concentration: 1 μmol / L) was performed.

[0030] Nine psychotropic drug conditions (8 single agents + 1 combination) were evaluated: SPM; escitalopram, DXN; duloxetine, PGN; pregabalin, APZ; aripiprazole, MZP; mirtazapine, DPZ; donepezil, NFN; nalfurafine, DKN; difelikefalin, NFN + DPZ; and the combination of nalfurafine and donepezil. Total RNA extraction from cells for transcriptome analysis was performed by removing the medium from 6-well culture plates, washing with ice-cold D-PBS(-), and adding 2-mercaptoethanol-containing Buffer RLT Plus (included in the RNeasy™ Plus Mini Kit) for RNA extraction. Total RNA extraction was performed according to the kit protocol (RNeasy™ Plus Mini Kit, QIAGEN). The extracted RNA was confirmed to be free of RNA degradation (RIN value ≥ 9.6) using an Agilent 2100 Bioanalyzer System. Human mRNA transcriptome analysis was performed using a microarray (3D-Gene mRNA Oligo chip, AROS (trademark) equipped with 24,460 probes, Toray Industries, Inc.) according to a previously described method (Ueno et al., Biomed Res Int. 2015, 2015:960840. doi:10.1155 / 2015 / 960840).

[0031] [Oligodendrocyte markers and their expression induction by compounds] In this study, we searched for compounds that activate oligodendrocytes to perform axonal regeneration, repair, and maintenance. To this end, we extracted genes as markers for oligodendrocytes and their precursor cells. Some of these genes have been reported in related papers. For example, genes (symbol, HGNC ID number, gene name) listed in Non-Patent Document 3 include PDGFRA (HGNC:8803 NCBI Gene:5156, platelet-derived growth factor receptor alpha), CSPG4 (HGNC:2466 NCBI Gene:1464, chondroitin sulfate protein oligodendrocyte lycan 4), OLIG1 (HGNC:16983 NCBI Gene:116448, oligodendrocyte transcription factor 1), OLIG2 (HGNC:9398 NCBI Gene:10215, oligodendrocyte lineage transcription factor 2), SOX10 (HGNC:11190 NCBI Gene:6663, SRY-box 10), PLP1 (HGNC:9086 NCBI Gene:5354, proteolipid protein 1), and MBP (HGNC:6925 Representative examples include a group of nine genes, including MOBP (HGNC:7189 NCBI Gene:4336, myelin-associated oligodendrocyte basic protein), and M oligodendrocyte (HGNC:7197 NCBI Gene:4340, myelin oligodendrocyte glycoprotein). The transcription factors OLIG1 and OLIG2 are particularly important as they control the differentiation and maturation of oligodendrocytes.

[0032] We performed transcriptome analysis in human keratinocytes to investigate the effects of psychotropic drugs, which are not known to have any effect on oligodendrocytes or axons. We found that OLIG1 expression was significantly increased when NFN and DPZ were administered in combination (NFN+DPZ) (Fig. 2). Interestingly, DPZ and NFN each suppressed OLIG1 expression (Fig. 1), but their combined use significantly increased expression. These findings suggest that NFN+DPZ strongly activates oligodendrocytes and contributes to neurotransmission through the preservation of axons.

[0033] [Possible gene expression of NFN and DPZ] DPZ is an acetylcholinesterase inhibitor and is expected to have a positive effect on the gene expression of the acetylcholine synthesis system and cholinergic receptors. On the other hand, NFN is a kappa opioid agonist and is expected to have a negative effect on the GABA synthesis system and GABA receptor system. This was investigated by transcriptome analysis. As shown in Figure 2, in the case of NFN + DPZ, the gene expression of NFN and DPZ alone was maintained, while in the case of NFN + DPZ, there was a tendency for gene expression to be synchronized with that of NFN.

[0034] We also analyzed the top 300 genes expressed under each condition for biological processes (GO-BP) using the enrichment analysis tool Metascape. Metascape (Zhou et al., Nature Communications 2019, 10:1523. doi:10.1038 / s41467-019-09234-6) is a highly accurate analysis tool that has been used in over 6,300 research papers since its publication in 2019 (as of July 2024). Gene Ontology (GO)-based biological processes were investigated using gene enrichment analysis. As shown in Table 1, NFN + DPZ induced more neural events than either NFN or DPZ alone, resulting in a synergistic effect on cell activation. In particular, OLIG1 expression was included in GO:0031175 (biological process: neuronal projection development), indicating enhanced neurotransmission. This result was consistent with the fact that the combination of NFN and DPZ activates oligodendrocytes and enhances neurotransmission events.

[0035] [Animal pharmacological evaluation of NFN+DPZ] The synergistic effects of NFN+DPZ were investigated in a behavioral pharmacology study in mice. It was predicted that the cognitive improvement effects of DPZ would be enhanced if oligodendrocytes, axonal integrity, and neurotransmission were activated by NFN+DPZ. Therefore, we used male ddy mice (5-7 weeks old, n = 9-14 per group) to evaluate the spatial memory function of mice induced with the muscarinic receptor antagonist scopolamine (1.0 mg / kg, i.p.) in a model of cognitive impairment. The Y-maze test assessed the number of times mice entered different arms to search for food (spontaneous alternation rate [%)).

[0036] In general, the key benefit of combination drugs is the enhanced efficacy while simultaneously reducing the dose of each drug, thereby mitigating side effects. The challenge for NFN and DPZ is whether they can be used together at low doses. Therefore, we decided to examine the synergistic effect of NFN + DPZ using low doses (equivalent to the clinical no-effect level) at which each drug exerts no pharmacological effect. At high doses, NFN produces behavioral suppression (sedative effect). The no-effect level was set at 0.1 μg / kg, a dose at which this does not occur (a dose at which the total number of intrusions does not decrease) (Figure 4). This dose is 1 / 100 of the 10 μg / kg dose in mice at which NFN exerts its clinical effect of suppressing itch, and coincides with the no-effect level at which the main pharmacological effects, such as sedation and itch suppression, do not occur.

[0037] Similarly, DPZ was evaluated in the Y-maze test using cognitive impairment model mice administered the muscarinic receptor antagonist scopolamine (1.0 mg / kg, i.p.). DPZ at 5.0 mg / kg i.p. tended to increase the rate of spontaneous alternation (%), but the change was not significant. The no-effect dose of DPZ, which did not induce any behavioral changes in the rate of spontaneous alternation (%) or total number of entries, was set at 1.0 mg / kg (Figure 5).

[0038] At the no-effect dose range of both drugs, NFN + DPZ did not significantly affect the total number of entries in any treatment group, but significantly increased the rate of spontaneous alternation (%) (Fig. 6). Therefore, it was demonstrated that NFN significantly enhanced the effect of DPZ on improving spatial recognition memory in scopolamine-induced cognitive impairment model mice.

Claims

1. An agent for enhancing the expression of oligodendrocyte transcription factor 1 (OLIG1), which contains a combination or a combination of donepezil and a kappa opioid agonist as active ingredients.

2. The OLIG1 expression enhancer of claim 1, wherein the kappa opioid agonist is nalfurafine.

3. The OLIG1 expression enhancer according to claim 2, wherein either or both of donepezil and nalfurafine are administered in a dose lower than the clinical dose range of each drug when used alone or in combination.

4. The OLIG1 expression enhancer according to any one of claims 1 to 3, wherein the enhanced OLIG1 expression is intended to repair and preserve axons in nervous system diseases by activating oligodendrocytes, and is used to treat a disease selected from Alzheimer's disease (AD, vascular dementia (VD), frontotemporal dementia (FTD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), Parkinson's disease (PD), Huntington's disease (HD), Sydenham's chorea, hepatolenticular degeneration (WD), multiple system atrophy (MSA), spinocerebellar degeneration (SCD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), multiple sclerosis (MS), neuromyelitis optica (NMO), and leukodystrophy.

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