Use of polypeptide in preparing drug for treating and / or preventing cognitive disorder

Abstract

The present invention relates to use of a polypeptide in preparing a drug for treating and / or preventing cognitive disorder and belongs to the technical field of cognitive disorder drugs. Specifically disclosed is use of an artificially synthesized small-molecule polypeptide in preparing a drug for treating and / or preventing cognitive disorder. When applied to a cognitive disorder model, the small-molecule polypeptide can effectively exert the biological effect of blocking the binding of Synapsin IIb (Syn2b) to an AMPA receptor subunit (GluA2). This increases membrane insertion of GluA2, resulting in increased AMPA current, elevated neuronal excitability, and enhanced synaptic transmission, thereby relieving the learning memory damage of a cognitive disorder model mouse to a certain extent.

Description

Application of a polypeptide in the preparation of drugs for the treatment and / or prevention of cognitive impairment [Technical Field]

[0001] This invention relates to the field of cognitive impairment drug technology, and more specifically, to the use of a polypeptide in the preparation of drugs for the treatment and / or prevention of cognitive impairment. [Background Technology]

[0002] Alzheimer's disease (AD) is an insidious, progressive neurodegenerative disease of the central nervous system, primarily affecting the elderly. It is the most common type of dementia and has become the most prevalent dementia, second only to cardiovascular disease in its high incidence rate. Its main symptom is progressive memory loss, often beginning with short-term memory decline, eventually progressing to long-term memory impairment and death. This disease severely impacts patients' lives, causing immense suffering and placing a heavy burden on families and society. It also has a significant emotional and psychological impact on patients and their loved ones. Therefore, with the increasing prominence of an aging population, research into the pathological basis of AD and the development of preventative drugs are urgently needed.

[0003] Neural synapses are the functional connections between neurons and are crucial for neuronal information transmission and communication. Synapses are the basic units in the brain; synaptic activity stimulates the maturation of mushroom-shaped dendritic spines and the formation of new synapses, allowing synaptic strength to adapt to changes in the internal and external environment, thus playing a vital role in learning and memory. Synapses are a family of neuron-specific synaptic vesicle-associated phosphorylation proteins related to synaptic vesicles, playing an important role in regulating neurotransmitter release and participating in early neuronal development. Synapsin II (Syn2) is a member of the synaptic protein (Synapsin I / II / III) family, translated through selective splicing into two protein subtypes: 547 amino acids (Syn2a) and 478 amino acids (Syn2b), participating in vesicle anchoring, release, and neurotransmission. Studies have shown through immunoprecipitation experiments that Syn2b, rather than Syn2a, can bind to glutamate receptor 2 (GluA2), thereby affecting AMPA receptor membrane transport. In the brain, the AMPA-type glutamate receptor (AMPAR) and its helper subunits form a complex that mediates most rapid excitatory neurotransmissions. Studies have shown that adeno-associated virus (AAV) overexpressing Syn2b protein in the mPFC brain region recording excitatory postsynaptic currents revealed a significant decrease in the amplitude of excitatory postsynaptic currents in neurons overexpressing Syn2b. This suggests that Syn2b may affect learning and memory-related mechanisms by modulating the AMPA receptor membrane. Increasing evidence indicates that excitatory amino acids (especially glutamate) play a crucial role in the pathogenesis of Alzheimer's disease (AD). AMPA receptors and their subunits are involved in synapse formation, extension, and many aspects of learning and memory processes based on synaptic plasticity. Therefore, abnormalities in AMPA receptor function are particularly closely related to the pathogenesis of many diseases, including Alzheimer's disease, frontotemporal dementia, and Parkinson's disease.

[0004] TAT, or cell penetrating peptides, is a highly efficient transport carrier discovered in recent years. TAT can penetrate cell membranes and nuclear membranes, carrying peptides, proteins, and DNA molecules into the cytoplasm and nucleus via receptor transport to exert corresponding biological effects. Current research shows that HIV-TAT can penetrate all tissue cells without significant toxic side effects. TAT can deliver its associated peptides into cells within minutes and can cross the blood-brain barrier to enter neurons. The peptides delivered into the cells retain their original biological activity, thus exerting their biological effects.

[0005] [Summary of the Invention]

[0006] The present invention aims to provide a small molecule polypeptide P6, the sequence of which is shown in SEQ ID NO.1. Further, a membrane-penetrating peptide with the sequence shown in SEQ ID NO.2 is attached to the N-terminus of P6. The present invention further links the TAT membrane-penetrating peptide (YGRKKRRQRRR, i.e., SEQ ID NO.2) with P6 (YILDCN, i.e., SEQ ID NO.1) to obtain a biologically active TAT-P6 polypeptide (YGRKKRRQRRRYILDCN, i.e., SEQ ID NO.3). Utilizing the membrane-penetrating function of TAT, the P6 polypeptide is delivered into the bloodstream and crosses the blood-brain barrier, where it is taken up by brain nerve cells to exert its biological function.

[0007] According to a first aspect of the present invention, an application of a polypeptide in the preparation of a drug for treating and / or preventing cognitive impairment is provided, wherein the amino acid sequence of the polypeptide is shown in SEQ ID NO:1.

[0008] Preferably, the cognitive impairment is a perceptual impairment, a memory impairment, or a thinking impairment.

[0009] Preferably, the sensory impairment is hypersensitivity, hyposensitivity, interoceptive discomfort, sensory degeneration, sensory deprivation, pathological illusion or hallucination, or sensory integration disorder.

[0010] The memory impairment is defined as excessive memory, memory deficit, or memory error.

[0011] The aforementioned thought disorders include obstacles to the abstract generalization process, obstacles to the association process, obstacles to logical thinking, or delusions.

[0012] Preferably, the cognitive impairment is caused by Alzheimer's disease, Lewy body dementia, frontotemporal dementia, Parkinson's disease, or Huntington's disease.

[0013] Or it could be cognitive impairment following traumatic brain injury, cognitive impairment following cerebrovascular disease, or cognitive impairment following surgery;

[0014] Or cognitive impairment caused by progressive supranuclear palsy, cortical basement membrane degeneration, argyrophilic granulation disease, Picker's disease, neurasthenia, hysteria, hypochondria, menopausal syndrome, depression, obsessive-compulsive disorder, schizophrenia, reactive psychosis, paranoid psychosis, mania, or bipolar disorder.

[0015] Preferably, the polypeptide is used to block the binding of Syn2b protein to GluA2 protein, thereby increasing the membrane surface area of ​​GluA2 protein.

[0016] Preferably, the polypeptide is used to promote an increase in neuronal AMPA current, thereby increasing spontaneous excitatory postsynaptic current.

[0017] Preferably, the N-terminus of the polypeptide is further connected to a membrane-penetrating peptide.

[0018] Preferably, the amino acid sequence of the membrane-penetrating peptide is shown in SEQ ID NO:2.

[0019] According to another aspect of the present invention, a polypeptide for preparing a treatment and / or prevention of cognitive impairment is provided, the amino acid sequence of said polypeptide being shown in SEQ ID NO:1.

[0020] Preferably, the N-terminus of the polypeptide is further connected to a membrane-penetrating peptide;

[0021] Preferably, the amino acid sequence of the membrane-penetrating peptide is shown in SEQ ID NO:2.

[0022] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0023] (1) This invention provides a membrane-permeable small molecule polypeptide P6 composed of only 6 amino acids, the sequence of which is shown in SEQ ID NO.1 of the sequence listing. By reducing the binding of Syn2b to GluA2, it improves the learning and memory abilities of cognitively impaired mice (such as AD mice). Further, a membrane-penetrating peptide with the sequence shown in SEQ ID NO.2 is attached to the N-terminus of P6. This invention further links the TAT membrane-penetrating peptide (YGRKKRRQRRR, i.e., SEQ ID NO.2) with P6 (YILDCN, i.e., SEQ ID NO.1) to obtain a biologically active TAT-P6 polypeptide (YGRKKRRQRRRYILDCN, i.e., SEQ ID NO.3). Utilizing the membrane-penetrating function of TAT, the P6 polypeptide is delivered into the blood and crosses the blood-brain barrier, and is taken up by brain nerve cells to exert its biological function.

[0024] (2) The small molecule polypeptide TAT-P6 involved in this invention has high purity, is completely soluble, is suitable for subcutaneous injection, and has no toxic side effects.

[0025] (3) The TAT-P6 polypeptide disclosed in this invention can carry P6 protein polypeptide through the blood-brain barrier and be taken up by neurons. It can be transformed and applied to the nervous system to regulate the learning and memory of Alzheimer's disease, making it feasible in practice.

[0026] (4) Preferably, the polypeptide of the present invention is used to treat learning and memory impairment in AD model mice. By subcutaneous injection, it can effectively block the binding of Syn2b and GluA2, restore the learning and memory ability of AD model mice, and provide a method to improve the adverse effects caused by AD. [Attached Image Description]

[0027] Figure 1 shows the mass spectrometry analysis of the artificial synthesis of a small molecule polypeptide, TAT-P6.

[0028] Figure 2 shows the immunoprecipitation diagram of the TAT-P6 peptide and the control peptide TAT-S6 disrupting the binding of HA-GluA2 and EGFP-Syn2b overexpression plasmids in HEK293T cells co-transfected with these overexpression plasmids. First, HA-GluA2 and EGFP-Syn2b overexpression plasmids were transfected into HEK293T cells. Forty-eight hours after transfection, cells were treated with 10 μM TAT-P6 and TAT-S6 peptides in cell culture medium for 90 minutes. TAT-P9 is based on P6 with three amino acids added to its N-terminus (CLQYILDCN). Cells were then collected. The overexpressed Syn2b protein is a fusion protein of Syn2b and GFP. Cell proteins were precipitated with anti-GFP antibody, and the precipitated protein was detected with anti-GluA2 antibody. The black blot on the NC membrane indicated the interaction between GluA2 and Syn2b. After administration of 10 μM TAT-P6 and TAT-P9, the anti-GluA2 antibody was almost undetectable on the corresponding protein on the NC membrane, suggesting that TAT-P6 blocked the interaction between Syn2b and GluA2. In contrast, the control group administered TAT-S6 showed a clear detection of GluA2 protein, indicating that TAT-S6 could not block the interaction between Syn2b and GluA2.

[0029] Figure 3 shows the statistical results of TAT-P6 peptide improving learning and memory abilities in mice. A and B represent the four groups of mice (C57 mice injected with TAT-S6, C57 mice injected with TAT-P6, P301S mice injected with TAT-S6, and P301S mice injected with TAT-P6) undergoing behavioral experiments using an open field testing system. Figure A shows the statistical results of the total movement distance of the four groups of mice in the open field experiment. There was no statistically significant difference in the total movement distance between the C57 mice injected with TAT-S6 peptide solution and those injected with TAT-P6 peptide solution. Similarly, there was no statistically significant difference in the total movement distance between the P301S mice injected with TAT-S6 peptide solution and those injected with TAT-P6 peptide solution. Figure B shows the statistical results of the time spent in the center position of the four groups of mice in the open field experiment. There was no statistically significant difference in the time spent in the center position between the C57 mice injected with TAT-S6 peptide solution and those injected with TAT-P6 peptide solution. There was no statistically significant difference in the time P301S mice injected with TAT-S6 peptide solution spent at the center position compared to those injected with TAT-P6 peptide solution. This indicates that TAT-S6 did not alter the motor abilities of the mice. In the data below, C represents the behavioral experiments conducted using the novel object recognition test system on the four groups of mice. Data in C indicates that P301S mice injected with TAT-S6 peptide solution spent less time at the new object, while those injected with TAT-P6 peptide solution spent more time at the new object. DH represents the behavioral experiments conducted using the Morris water maze test system on the four groups of mice. Data in D shows the movement trajectories of the two groups of mice on day 8 of the water maze experiment. Data in E shows the latency statistics during the first 6 days of training. Data in F shows the latency statistics for the four groups of mice during the water maze test on day 8. P301S mice injected with TAT-S6 peptide solution showed a prolonged latency to reach the platform, while those injected with TAT-P6 peptide solution showed a significantly reduced latency. Figure G shows the statistical results of the number of times the mice crossed the platform quadrant in the water maze test on day 8. The number of platform crossings by P301S mice injected with TAT-S6 peptide solution was significantly less than that by those injected with TAT-P6 peptide solution. This indicates that TAT-P6 peptide injection can effectively improve the learning and memory function of P301S mice. Figure H shows the statistical results of the time spent in the target quadrant in the water maze test on day 8. The time spent in the target quadrant by P301S mice injected with TAT-S6 peptide solution was significantly less than that by those injected with TAT-P6 peptide solution. This indicates that TAT-P6 peptide injection can effectively improve the learning and memory function of P301S mice. Where I represents the percentage of mouse rigidity time (%) in the four groups of mice under the scenario-based fear experiment.Where J represents the percentage (%) of mouse rigidity time after environmental change following a cue-based situational fear experiment in four groups of mice.

[0030] Figure 4 shows the statistical results of Western blot analysis showing that the total protein levels of Syn2b and GluA2 were not altered by the TAT-P6 peptide. Using the proteins prepared above, the levels of Syn2b and GluA2 in mice in the TAT-P6 peptide group and the control group were detected, with GAPDH as an internal control band, demonstrating the consistency of protein loading. Comparison revealed that the protein levels of Syn2b and GluA2 in mice administered subcutaneously with 15 mg / kg of TAT-P6 solution did not significantly change compared to the control group.

[0031] Figure 5 shows the statistical results of immunoblotting showing that TAT-P6 peptide increased GluA2 on the upper membrane. After behavioral studies, membrane proteins in the mouse hippocampus were isolated. Immunoblotting revealed that the GluA2 protein level on the membrane of mice treated with TAT-P6 peptide solution was significantly higher than that in the control group, and ATP1A1 served as the internal reference band for membrane proteins.

[0032] Figure 6 shows the statistical results of AMPA current enhancement in mouse neurons by TAT-P6 peptide. C57 and P301S mice were euthanized by cervical dislocation and decapitation after anesthesia. Brain tissue was quickly extracted and placed in frozen artificial cerebrospinal fluid (aCSF). The hippocampus was isolated according to experimental requirements, and the tissue was sliced ​​into 300 μm thick sections using a vibratory slicer and incubated at room temperature for 1 h. Subsequently, the tissue was treated with 10 μM TAT-P6 solution or 10 μM TAT-S6 solution for 30 min. Appropriate stimulation and recording electrode positions were selected to record AMPA and NMDA currents in the hippocampus. Ten cells were recorded per slice. The experiment showed that treatment with 10 μM TAT-P6 solution increased the AMPA current amplitude compared to incubation with 10 μM TAT-S6 solution, while the NMDA current did not change significantly, and the NMDA / AMPA ratio decreased significantly.

[0033] Figure 7 shows the statistical results of TAT-P6 peptide enhancing neuronal excitability in mice. Spontaneous excitatory aftercurrents (sEPSCs) in the hippocampus of P301S mice were recorded, with 10 cells recorded per brain slice. The experiment showed that treatment with 10 μM TAT-P6 solution increased the amplitude of sEPSCs compared to incubation with 10 μM TAT-S6 solution, demonstrating enhanced neuronal excitability.

Detailed Implementation Methods

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The present invention aims to provide a small molecule polypeptide P6, the sequence of which is shown in SEQ ID NO.1. Further, a membrane-penetrating peptide with the sequence shown in SEQ ID NO.2 is linked to the N-terminus of P6. The present invention further links the TAT membrane-penetrating peptide (YGRKKRRQRRR, i.e., SEQ ID NO.2) with P6 (YILDCN, i.e., SEQ ID NO.1) to obtain a biologically active TAT-P6 polypeptide (YGRKKRRQRRRYILDCN, i.e., SEQ ID NO.3). Utilizing the membrane-penetrating function of TAT, the P6 polypeptide is delivered into the bloodstream and crosses the blood-brain barrier, where it is taken up by brain nerve cells to exert its biological function. The control for TAT-P6 is TAT-S6, the sequence of which is shown in SEQ ID NO.4, and is as follows: YGRKKRRQRRRCNDILY.

[0036] Preferably, this invention provides a small molecule polypeptide TAT-P6, and its application in improving cognitive impairment, further in Alzheimer's disease, and even further in improving learning and memory behavior in Alzheimer's patients. Subcutaneous injection of TAT-P6 has shown that it effectively blocks the binding of Syn2b to GluA2, leading to increased GluA2 on the upper membrane, increased AMPA current, increased neuronal excitability, and enhanced synaptic transmission, thereby restoring learning and memory abilities in a mouse model of Alzheimer's disease to a certain extent.

[0037] In this invention, the TAT-P6 polypeptide and the control TAT-S6 were synthesized by the applicant through a commission to Qiangyao Biotechnology Co., Ltd.

[0038] Example 1

[0039] Experimental materials:

[0040] This invention utilizes a randomized method of subcutaneously injecting TAT-P6 solution into P301S and C57 / BL6 mice to block the binding of GluA2 and Syn2b, thereby improving learning and memory impairment in AD mice.

[0041] The specific operating steps are as follows:

[0042] I. Application of TAT-P6 peptide in improving cognitive impairment.

[0043] 1. Experimental subjects

[0044] Male P301S mice, 6-8 months old (purchased from Jackson Laboratory), and C57 / BL6 mice, 6-8 months old (purchased from Beijing Vital River Laboratory Animal Co., Ltd.), SPF grade, weighing 20-25 grams, were housed in a standard environment.

[0045] 2. Research Methods

[0046] 1) Spatial memory test in mice: novel object recognition and water maze;

[0047] a) Novel Object Recognition: Before the novel object recognition experiment, it's essential to eliminate the unfamiliarity between the mouse and the parent animal by petting it daily to avoid stimulating it during the procedure. In Phase 1, the adaptation period, the mouse moves freely within the experimental setup (without objects) for 10 minutes. Then, in Phase 2, the familiarization period, two identical objects (A and B, ensuring the objects are odorless and cannot be moved) are placed in the setup, 10cm from the side walls. The mouse is placed in the setup from an equal distance with its back to the objects. A camera and software record the time the mouse spends exploring each object (exploration is defined as the mouse's mouth or nose touching the object or coming within approximately 2-3cm). Within 5 minutes (many experiments have shown that animals develop a good preference for novel objects after 2 minutes of familiarization, and this preference is even more pronounced after 3 minutes), the number of times, the duration, and the distance the animal explores each object are measured. In Phase 3, the testing period, generally 1 hour after the completion of Phase 2 is chosen as the interval for testing memory (longer intervals can be used to evaluate the effectiveness of memory improvement). Replace one of the two identical objects with a different object and place it in the device (AC or BC). Similarly, place the mouse in the device with its back to the object from an equal distance for 5 minutes.

[0048] b) Morris water maze experiment: The Morris water maze consists of a circular pool with a diameter of 120 cm and a height of 60 cm; a cylindrical plexiglass platform with a diameter of 10 cm and a height of 40 cm. The water level in the pool is about 45 cm high, and both the room temperature and water temperature are maintained at 22 ± 2°C. The platform is placed at the center of a certain quadrant and submerged about 2 cm below the water surface. During training, the mice are gently placed into the water with their heads facing the pool wall at a 1 / 2 radian position in any quadrant, and their latency (i.e., the time from when the mouse enters the water until it finds the platform) and path are measured as indicators to evaluate the learning, memory, and test performance of the mice. Each mouse is trained 3 times in 3 quadrants every day, and the swimming time limit for each time is 90 s. That is, if the platform is not found within 90 s, the system automatically stops recording, and the latency is recorded as 90 s. The tester then guides the mouse onto the platform, and after a 20-s rest, the next training session begins. The initial training period is 6 days, and the time required for the mouse to find the platform is recorded each day as the latency for the mouse to find the platform. After a one-day rest, the platform is removed, and the time the mouse stays in the target quadrant within 60 s is calculated, and the number of times it crosses the position where the platform was located is analyzed to evaluate its memory ability.

[0049] 2) Detection of other behaviors in mice: Open field test, conditioned fear experiment;

[0050] Open field test: The open field test is an experiment in which animals are placed in an open metal box area with a length of 80 cm, a width of 80 cm, and a height of 50 cm to observe the activities of mice. This area is divided into squares, and usually, the number of squares crossed by the mice within a given time is counted to examine the anxiety state and self-motor ability of the mice待用 for the experiment. First, the mice need to be placed in the open field test room for 1 - 2 days before the experiment, with distinct day and night. Set the experimental area on the computer, evenly divide the experimental area into a "hui" shape, with the innermost circle as the central area and the outermost periphery as the edge area. Then turn on the camera, adjust the light source, and use the computer to record information such as the position, movement route, and distance of the experimental mice. Stop the camera after observing for a certain period of time, usually about 5 minutes.

[0051] 3) Quantification of the content of mouse hippocampus-related proteins: Immunoblotting;

[0052] 4) Disrupting the binding of Syn2b and GluA2 in HEK 293T cells: Immunoprecipitation, immunoblotting.

[0053] 3. Experimental results

[0054] *P < 0.05, compared with the control group

[0055] **P < 0.01, compared with the control group

[0056] ***P < 0.001, compared with the control group

[0057] The sequence of TAT-P6, as shown in SEQ ID NO:3, was synthesized by Jiangsu Qiangyao Biotechnology Co., Ltd. Mass spectrometry analysis, as shown in Figure 1, revealed that the amino acid sequence of the synthesized peptide is identical to that of SEQ ID NO:3. The synthesized TAT-P6 peptide has a purity of 95.03%. One 10mg vial is a white powder, completely soluble in water, and should be stored sealed and protected from light at -20°C. The sequence of TAT-S6, as shown in SEQ ID NO:4, was also synthesized by the same company.

[0058] Peptide alters learning and memory impairment in mice: see Figure 3. C57 and P301S mice were administered 15 mg / kg of TAT-P6 peptide solution, while control mice were subcutaneously injected with 15 mg / kg of TAT-S6 peptide solution, for 14 consecutive days. Behavioral tests revealed that P301S mice injected with 15 mg / kg of TAT-P6 solution showed significantly improved learning and memory compared to P301S mice injected with TAT-S6 peptide solution.

[0059] Example 2

[0060] This invention utilizes subcutaneous injection of TAT-P6 solution into C57 and P301S mice to effectively block the biological effects of Syn2b binding to GluA2, thereby increasing the upper membrane of AMPA receptors, enhancing neuronal excitability, and strengthening synaptic transmission.

[0061] In cell experiments, the binding of Syn2b and GluA2 was disrupted: (See Figure 2) HEK 293T cells were co-transfected with plasmids expressing Syn2b and the AMPA receptor subunit (GluA2). Forty-eight hours after transfection, cells were treated with either 10 μM TAT-P6 or 10 μM TAT-S6 for 90 minutes, and then cell proteins were collected. The expressed Syn2b protein is a fusion protein of Syn2b and GFP. Cell proteins were precipitated with anti-GFP antibody, and the precipitated protein was detected with anti-GluA2 antibody. Immunoblotting on the NC membrane indicated the interaction between GluA2 and Syn2b. The results showed that after administration of 10 μM TAT-P6, the anti-GluA2 antibody was almost undetectable on the NC membrane, suggesting that TAT-P6 blocked the interaction between Syn2b and GluA2. In contrast, the control group treated with TAT-S6 showed a clear detection of GluA2 protein, indicating that TAT-S6 could not block the interaction between Syn2b and GluA2.

[0062] Quantitative analysis of Syn2b and GluA2 levels in the mouse hippocampus: see Figure 4. After behavioral testing, immunoblotting of tissue proteins in mice showed that subcutaneous injection of 15 mg / kg TAT-P-6 did not affect the protein levels of Syn2b and GluA2.

[0063] Quantitative analysis of GluA2 on mouse hippocampal cell membranes: see Figure 5. Membrane proteins and cytoplasmic proteins were isolated from mouse hippocampal tissue. Immunoblotting revealed that the GluA2 protein level on the cell membranes of mice treated with TAT-P6 peptide solution was significantly higher than that in the control group.

[0064] Electrophysiological recording results: See Figures 6 and 7. Brain slices were treated with either 10 μM TAT-P6 or 10 μM TAT-S6 solution for 30 min during incubation. Subsequently, AMPA and NMDA currents in the hippocampus were recorded. The 10 μM TAT-P6 solution group showed increased AMPA current amplitude, but no significant change in NMDA current, and a significantly decreased NMDA / AMPA ratio. Spontaneous excitatory postsynaptic potentials (sEPSCs) were recorded, and the 10 μM TAT-P6 solution treatment significantly increased the amplitude of sEPSCs.

[0065] in conclusion

[0066] The above results show that in P301S mice, the TAT-P6 injection group exhibited significantly shortened latency in the Morris water maze, significantly increased time and distance spent in the target quadrant, and significantly increased number of platform crossings, indicating enhanced learning and memory abilities. This demonstrates that TAT-P6 can significantly improve learning and memory behaviors. Immunoprecipitation assays showed that TAT-P6 can interrupt the binding of Syn2b to GluA2 both in vitro and in vivo, increasing the GluA2 membrane. Electrophysiological experiments demonstrated increased neuronal excitability and enhanced synaptic transmission. TAT-P6 peptides may be used to improve learning and memory abilities in Alzheimer's disease.

[0067] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0068] sequence list

Claims

1. The use of a polypeptide in the preparation of drugs for the treatment and / or prevention of cognitive impairment, characterized in that, The amino acid sequence of the polypeptide is shown in SEQ ID NO:

1.

2. The application as described in claim 1, characterized in that, The cognitive impairment refers to perceptual impairment, memory impairment, or thinking impairment.

3. The application as described in claim 2, characterized in that, The sensory disturbances mentioned are hyperesthesia, hypoesthesia, interoceptive discomfort, sensory deprivation, pathological illusions or hallucinations, or sensory integration disorders. The memory impairment is defined as excessive memory, memory deficit, or memory error. The aforementioned thought disorders include obstacles to the abstract generalization process, obstacles to the association process, obstacles to logical thinking, or delusions.

4. The application as described in claim 1, characterized in that, The cognitive impairment referred to is cognitive impairment caused by Alzheimer's disease, Lewy body dementia, frontotemporal dementia, Parkinson's disease, or Huntington's disease. Or it could be cognitive impairment following traumatic brain injury, cognitive impairment following cerebrovascular disease, or cognitive impairment following surgery; Or cognitive impairment caused by progressive supranuclear palsy, cortical basement membrane degeneration, argyrophilic granulation disease, Picker's disease, neurasthenia, hysteria, hypochondria, menopausal syndrome, depression, obsessive-compulsive disorder, schizophrenia, reactive psychosis, paranoid psychosis, mania, or bipolar disorder.

5. The application as described in claim 1, characterized in that, The polypeptide is used to block the binding of Syn2b protein to GluA2 protein, thereby increasing the membrane surface area of ​​GluA2 protein.

6. The application as described in claim 1, characterized in that, The polypeptide is used to promote an increase in neuronal AMPA current, thereby increasing spontaneous excitatory postsynaptic current.

7. The application as described in claim 1, characterized in that, The N-terminus of the polypeptide is also linked to a membrane-penetrating peptide.

8. The application as described in claim 7, characterized in that, The amino acid sequence of the membrane-penetrating peptide is shown in SEQ ID NO:

2.

9. A polypeptide for preparing a treatment and / or prevention of cognitive impairment, characterized in that, The amino acid sequence of the polypeptide is shown in SEQ ID NO:

1.

10. The polypeptide for preparing a treatment and / or prevention of cognitive impairment as described in claim 9, characterized in that, The N-terminus of the polypeptide is also attached to a membrane-penetrating peptide. Preferably, the amino acid sequence of the membrane-penetrating peptide is shown in SEQ ID NO:2.

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