Application of axon guiding factor Semaphorin3G in preparation of medicine for improving dyskinesia

Abstract

The invention belongs to the technical field of biological medicines, and particularly relates to application of an axon guiding factor Semaphorin3G in preparation of a medicine for improving dyskinesia. According to the application, a Semaphorin3G transgenic mouse is knocked out through vascular endothelial cells, cell and whole animal level tests prove that the Semaphorin3G can effectively improve cerebral ischemia and sciatic nerve repair and promote motor function recovery, and a basis is provided for application of the Semaphorin3G in motor dysfunction diseases caused by central or peripheral nerve ischemia.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical technologies, and particularly relates to the application of axon guidance factor Semaphorin3G in the preparation of drugs for improving motor dysfunction. Background Art

[0002] Ischemic stroke is an acute nerve injury disease, characterized by high incidence, high mortality, high disability rate, high recurrence rate and heavy economic burden. Therefore, the treatment and functional recovery after ischemic stroke are particularly important. The current functional recovery after stroke is achieved through two ways. One is the self-repair of brain tissue remodeling and synaptic plasticity around the infarct area, and the other is that the brain may generate nerve projections in the non-stroke contralateral hemisphere by repairing the signal conduction around or in a far area from the infarct area, thus contributing to functional recovery. The self-repair of brain tissue remodeling and synaptic plasticity is a difficult and hot issue in the prognosis treatment of ischemic stroke. Therefore, it is particularly important to clarify the intracellular signal transduction network and molecular regulation mechanism in the pathophysiological process mediating neuron remodeling and regeneration after injury.

[0003] In addition, as a widely distributed neural network, the Peripheral Nervous System (PNS) can integrate information from different parts of the body with the Central Nervous System (CNS). Among them, Peripheral Nervous System Injury (PNI) is the main type of traumatic injury to the nervous system, usually resulting in permanent loss of sensory, motor and autonomic nerve functions at the injury site, which has a significant impact on the daily activities of patients. At present, the treatment of PNI mainly relies on surgical intervention, such as autologous transplantation or allogeneic transplantation, but it is affected by limited donor supply and potential immunosuppression, and may even cause scarring and neuroma in severe cases. Synthetic nerve conduits have also been applied clinically. However, due to unstable results, they are currently only used for the repair of non-critical small-diameter sensory nerves. The combined use of artificial conduits and small molecule proteins promoting axon regeneration can avoid the defects of using conduits alone and play a good therapeutic role. However, there are few small molecule proteins promoting axon regeneration found at present. Therefore, it is also crucial to explore small molecule proteins beneficial to axon regeneration for peripheral nerve regeneration and functional recovery.

[0004] The main purpose of the present invention is to explore the rules and mechanisms of the regeneration and repair of damaged nerve fibers after central motor nerve or peripheral sciatic nerve injury, provide new drug targets for the treatment of motor dysfunction, thereby optimizing the clinical treatment effect, improving the prognosis level of patients and improving the quality of life.

[0005] Semaphorins (Semas) are a family of axon guidance molecules. As secreted proteins, Sema3s are members of the Semaphorins family, which are characterized by conserved signaling protein domains and are involved in various functions such as axon guidance, cell migration, and blood vessel development. Most of these functions are mediated by plexins, large transmembrane receptors with highly conserved cytoplasmic domains, and co-receptors such as neuropilin (Nrp). Among them, Sema3G is a secreted semaphorin in vertebrates, which contains a Sema domain, a PSI domain, and a signal peptide for guiding secretion. Through transcriptome screening, it was found that Sema3G is mainly secreted by vascular endothelial cells, with a full length of 100 kDa. After being processed by furin protease, it can produce subunits with a length of 95 kDa and 65 kDa containing the Sema domain. Full-length Sema3G binds to neuropilin-2 (Nrp2) protein, while the processed Sema3G binds to Nrp1 or Nrp2 and then exerts its function. Kutschera et al. showed that Sema3G binds to Nrp2 and induces sympathetic axon repulsion and smooth muscle cell (SMC) migration in culture. More and more evidence indicates that Sema3G is involved in cell migration and axon guidance. According to the guiding effect of Sema3G as an axon guidance molecule on axons, its effects and mechanisms on the recovery of local cerebral ischemia injury and the regeneration and repair of injured sciatic nerve fibers were explored at the cellular and animal levels respectively, providing a guiding direction and new ideas for the clinical treatment of central and peripheral motor dysfunction. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide the application of axon guidance factor (Semaphorin3G) in improving motor dysfunction. The present invention knocked out Semaphorin3G transgenic mice in vascular endothelial cells, and experimental evidence was provided for the application of Semaphorin3G in gene therapy for motor dysfunction diseases caused by central or peripheral nerve ischemia by demonstrating at the cellular and whole animal levels that Semaphorin3G can effectively promote sciatic nerve repair and reverse motor dysfunction.

[0007] The technical solution of the present invention is as follows:

[0008] In the first aspect, the present invention protects the application of axon guidance factor Semaphorin3G in improving motor dysfunction.

[0009] Among them, the accession number of axon guidance factor Semaphorin3G is: (Homo)NP_064548.1 or (Mus)NP_001020550.1.

[0010] The gene accession number encoding axonal guidance factor Semaphorin3G is: (Homo) NM_020163.3 or (Mus) NM_001025379.1.

[0011] The research of the present invention shows that Semaphorin3G can promote neuronal axon growth and protect against OGD-induced synaptic loss; overexpression of Semaphorin3G alleviates local cerebral ischemia-induced motor dysfunction, while deletion of Semaphorin3G delays the recovery of motor ability in mice, and overexpression of Semaphorin3G in the sciatic nerve promotes the recovery of motor ability in mice.

[0012] In a second aspect, the present invention protects the use of axonal guidance factor Semaphorin3G in the preparation of a drug for improving motor dysfunction.

[0013] In a third aspect, the present invention protects the use of a substance that promotes the expression of axonal guidance factor Semaphorin3G in the preparation of a drug for improving motor dysfunction.

[0014] Specifically, the present invention protects the use of a recombinant vector containing the axonal guidance factor Semaphorin3G-encoding gene in the preparation of a drug for improving motor dysfunction.

[0015] In a specific embodiment, the recombinant vector is a viral vector containing the axonal guidance factor Semaphorin3G-encoding gene.

[0016] In a more specific embodiment, the viral vector is an adenovirus vector, and more specifically an AAV vector.

[0017] In an even more specific embodiment, the adeno-associated virus is of the AAV2 / 9 type.

[0018] In a specific embodiment, the motor dysfunction is caused by ischemic stroke.

[0019] In a specific embodiment, the drug further contains other pharmaceutically acceptable excipients.

[0020] In a fourth aspect, the present invention protects a method for improving motor dysfunction, which is achieved by overexpressing axonal guidance factor Semaphorin3G.

[0021] Beneficial effects

[0022] The application of the axon guidance factor provided by the present invention in the preparation of drugs for improving motor dysfunction will clarify the molecular mechanism by which vascular endothelial-derived Semaphorin3G participates in the regulation of motor function, and explore a new mode of transcellular ligand-receptor information communication between endothelial cells and neurons through secreted proteins. Our research will provide experimental basis and new ideas for the development of drugs for treating motor dysfunction. Therefore, the use of Semaphorin3G provided by the present invention is expected to become an important new strategy for repairing motor nerve fibers and treating motor dysfunction. Brief Description of the Drawings

[0023] Figure 1 Semaphorin3G recombinant protein promotes axon growth.

[0024] Figure 2 Semaphorin3G recombinant protein protects against OGD-induced synaptic loss.

[0025] Figure 3 Overexpression of Semaphorin3G alleviates local cerebral ischemia-induced motor dysfunction.

[0026] Figure 4 Deletion of Semaphorin3G delays the recovery of motor ability in mice.

[0027] Figure 5 Overexpression of Semaphorin3G in the sciatic nerve promotes the recovery of motor ability in mice. Detailed Embodiments

[0028] The present invention will be further described in conjunction with the accompanying drawings and embodiments. However, the present invention is not limited to the scope of the described embodiments. Reagents or equipment not indicating the manufacturer are regarded as conventional products that can be purchased on the market.

[0029] The construction of AAV-Sema3G refers to Tan C, Lu NN, Wang CK, Chen DY, Sun NH, Lyu H, J, Shi WX, Fukunaga K, Lu YM, Han F. Endothelium-Derived Semaphorin 3G Regulates Hippocampal Synaptic Structure and Plasticity via Neuropilin-2 / PlexinA4. Neuron. 2019 Mar 6;101(5):920-937.e13. doi:10.1016 / j.neuron.2018.12.036. Epub 2019 Jan 23. PMID:30685224, commissioned by Hanheng Biotechnology (Shanghai) Co., Ltd. to prepare.

[0030] The construction of Sema3G knockout mice was referred to Tan C, Lu NN, Wang CK, Chen DY, Sun NH, Lyu H, J, Shi WX, Fukunaga K, Lu YM, Han F. Endothelium-Derived Semaphorin 3G Regulates Hippocampal Synaptic Structure and Plasticity via Neuropilin-2 / PlexinA4. Neuron. 2019 Mar 6;101(5):920-937.e13. doi:10.1016 / j.neuron.2018.12.036. Epub 2019 Jan 23. PMID:30685224.

[0031] Experimental method 1. Primary hippocampal pyramidal neuron extraction

[0032] Primary hippocampal pyramidal neurons were prepared from E18 mouse embryos with a C57BL / 6 background. Pregnant mice were anesthetized with isoflurane and then the uterus was dissected. The brain was dissected with ophthalmic forceps and the bilateral hippocampal tissues were separated into pre-cooled HBSS buffer at 4°C. The vascular membrane was removed with fine forceps and the whole operation was carried out on an ice plate. The hippocampal tissues were minced and then added to 0.25% trypsin solution containing 0.025% DNaseI. After digestion at 37°C for 15 minutes, an appropriate amount of fetal bovine serum was added to terminate the digestion. The digested tissues were transferred to an appropriate amount of low-glucose medium DMEM containing 10% fetal bovine serum, and the digested hippocampal tissues were gently pipetted repeatedly with a pipette tip until they were dispersed into a cell suspension and then centrifuged at 1000g for 5 minutes. The precipitated cells were pipetted evenly with low-glucose DMEM medium containing 10% fetal bovine serum, at 1x10 5Cells were seeded at a density of [number] cells / cm2 on glass coverslips coated with poly-L-lysine (50 μg / ml). After 4 hours of seeding (in a 37°C, 5% CO2 incubator), the medium was replaced with neuronal complete medium containing 2% B-27, 2 mM / L glutamine, and 50 U / mL penicillin / streptomycin. Half of the complete medium was replaced every 3 days.

[0033] 2. Microfluidic device culture experiment

[0034] The microfluidic culture device was tightly combined with a glass coverslip coated with poly-L-lysine and sterilized in an ultraviolet environment for 30 minutes. 30,000 - 40,000 cells were added to the cell body chamber of the microfluidic device and placed in a 37°C, 5% CO 2 incubator for 15 minutes to wait for the neuronal cells to adhere. After gently aspirating the medium, 100 μl of complete medium was added to both sides of the cell body chamber, and 100 μl of neuronal complete medium was added to one side of the axon chamber. The medium was changed by half every two days. Ensure that the upper cell body chamber is 200 μl and the lower axon chamber is 100 μl, which is beneficial for the axon to grow into the axon chamber along the liquid potential difference.

[0035] 3. Grid misstep experiment

[0036] Verify the ability of mice to control the movement of the forelimbs after stroke. The mice were placed on an elevated metal grid (grid size 14×14 mm) to freely explore for 3 minutes. Record the number of times the left and right forelimbs of the mice missed the grid and the number of times they stepped on the wires, and score and quantify the experimental results to determine the control and recovery of the forelimb movement ability of mice at different stages after stroke.

[0037] 4. Cup climbing experiment

[0038] Verify the ability of mice to rely on the coordination of the forelimbs after ischemia of the motor cortex M1. The mice were placed in a transparent glass cylinder (diameter 9.5 cm, height 16 cm) to freely move their forelimbs and touch the cup wall 20 times. A mirror was placed on the opposite side of the glass cylinder to reflect and observe the movement state of the forelimbs of the mice when their backs were facing the observer. Record the number of times the left and right forelimbs of each mouse and the number of times they touched the cup wall simultaneously and analyze: (number of times relying solely on the right forelimb - number of times relying solely on the left forelimb) / total number of times the mouse touched the cup wall. Analyze the number of touches to determine the change in the degree of dependence of mice on one forelimb at different stages after stroke.

[0039] 5. Toe extension reflex experiment

[0040] The mouse was grasped to expose its foot, and the toe extension reflex was formed due to the stimulation of the nerves of the small muscles of the mouse foot, and the foot was recorded with a video camera. The toe extension reflex was scored as follows: 0-no extension; 1-intermediate extension, all toes were separated for <2 seconds; 2-full extension, all toes were fully and widely extended for at least 2 seconds. Each group of mice was evaluated three times, with at least 10 minutes between each evaluation.

[0041] 6. Rotarod Assay

[0042] The mice were balanced on a moving rotating cylinder (3 cm in diameter). Before the formal experiment, the mice needed to be trained for 3 days and tested 3 times a day. On the first day: 4 rpm, 10 minutes of training, three times of training; on the second day: 4-15 rpm, 10 minutes of training, three times of training; on the third day: 4-40 rpm, the latency of the mice falling off the rotating cylinder was measured, and the average value was taken for the three measurements. Each test was 1 hour apart.

[0043] 7. Sciatic nerve index test

[0044] The hind limbs of mice were painted with black ink and allowed to walk in a narrow corridor covered with a white paper strip (10 × 60 cm). Three parameters were measured from the footprints to assess the SFI: (1) paw length (PL) was the distance from the third toe to the heel, (2) toe spread (TS) was considered to be the distance between the first and fifth toes, and (3) intermediate toe spread (ITS) was the distance between the second and fourth toes. The four clearest footprint measurements were taken from the injured ipsilateral experimental (E) paw on the left and the uninjured contralateral naive (N) paw on the right. The SFI was calculated using the following formula: Sciatic function index = -38.3 × (EPL-NPL) / NPL + (109.5 × (ETS-NTS) / NTS + (13.3 × (EITS-NITS) / NITS-8.8. An SFI score of 0 indicates normal function, while a score of -100 indicates complete damage to the sciatic nerve and the mouse is unable to move its hind limbs.

[0045] Example 1 Semaphorin 3G recombinant protein promotes axon growth

[0046] In order to analyze the effect of Sema3G on neuronal axon growth, primary mouse hippocampal pyramidal neurons were extracted and planted in a microfluidic device for in vitro culture. Neurons were planted on one side of the microfluidic device for culture, and only axons could grow through the microgrooves and reach the axon chamber, allowing axons to separate from the cell body ( Figure 1 A). After six days of in vitro culture, Sema3G recombinant protein (overexpression sequence is mouse NM_001025379.1) was added to the axon culture chamber, and the growth status of neuronal axons at different time points was observed using a living cell workstation (Figure 1 B). Compared with the control group, the axon growth rate of neurons with the addition of Sema3G recombinant protein was significantly accelerated ( Figure 1 C). By performing cellular immunofluorescence staining on the marker of neuronal axons (Neuroflament-H) ( Figure 1 D), it was found that the length of the terminal axons with the addition of Sema3G recombinant protein was significantly increased compared to the control group ( Figure 1 E). The above results indicate that: Sema3G recombinant protein promotes the growth of axons of primary cultured neurons.

[0047] Example 2 Semaphorin3G recombinant protein protects against OGD-induced synaptic loss

[0048] Through two Sema3G treatment methods: incubating Sema3G during reperfusion after OGD treatment, OGD 45min / Reperfusion+Sema3G(post)(S1); incubating Sema3G before OGD / R treatment, OGD 45min / Reperfusion+Sema3G(pre)(S2), to explore whether Sema3G is involved in the process of neuronal injury protection, and respectively observe the neuronal cytoskeleton morphology and synaptic number under the two methods.

[0049] The results of cellular immunofluorescence staining showed that: compared with the OGD / R model group without Sema3G incubation, for primary pyramidal neurons after 45 min of glucose and oxygen deprivation and 8 h of reperfusion (OGD / R-8h), although the number of synapses rescued after Sema3G treatment increased to some extent, there was no significant difference in statistical analysis ( Figure 2 A,C); in the experimental group of 45 min of glucose and oxygen deprivation and 10 h of reperfusion (OGD / R-10h), the rescue effect of incubating Sema3G after modeling was better than that of incubating Sema3G before modeling ( Figure 2 B,D); in the experimental group of 45 min of glucose and oxygen deprivation and 24 h of reperfusion (OGD / R-24h), the numbers of the presynaptic neurotransmitter marker vGluT1, the postsynaptic membrane marker PSD95, and mature synapses (co-localization of vGluT1 and PSD95) all showed a callback after Sema3G was incubated in two ways ( Figure 2 E,F). The above results suggest that Sema3G can rescue the loss of neuronal synaptic number caused by glucose and oxygen deprivation / reperfusion injury.

[0050] Example 3 Overexpression of Semaphorin3G alleviates local cerebral ischemia-induced motor dysfunction

[0051] To verify neuronal damage caused by early ischemia at the animal level and to evaluate the importance of ischemic-induced neuronal synapse loss and rescue, rose bengal (RB) local photothrombosis was performed in the primary motor cortex (M1) of mice, and the pathological changes of brain tissues were observed at 2 h and 4 h after surgery respectively. Whether spectrin was cleaved was detected by Western blot ( Figure 3 A). According to existing reports, spectrin can maintain the integrity of the cytoplasmic membrane and the cytoskeletal structure. When the brain tissue is damaged, spectrin will be cleaved to produce a 150 kDa active cleavage fragment, so it is a sensitive indicator for judging the homeostasis of the cytoskeleton and the neurovascular unit. The results showed that compared with the non-modeled area on the contralateral side of the same mouse, the active cleavage fragment (150 kDa) of spectrin in the ischemic area increased during the early stage of ischemic stroke ( Figure 3 B,C), indicating that the neurovascular unit was damaged by local rose bengal photothrombosis modeling, and brain tissue lesions occurred in the early stage, further confirming the successful construction of the local ischemia model.

[0052] To verify the loss of synapses in neurons of the primary motor cortex, the dendritic skeleton marker MAP2 and the presynaptic membrane neurotransmitter marker Synapsin1 of brain tissue neurons after ischemia were fluorescently labeled, and the degree of ischemic damage was quantitatively analyzed by the number of neurotransmitters. The results showed that compared with the non-modeled area on the contralateral side of the same mouse, the synaptic density in the ischemic area decreased during the early stage of ischemic stroke ( Figure 3 D). The above results indicate that synapses of neurons are more sensitive to the stress response of the ischemic environment in the early stage of ischemia in the primary motor cortex area, further suggesting that protecting synapses is the key to protecting neuronal damage during ischemic stroke.

[0053] In addition, based on the ischemic animal model, the motor dysfunction after ischemia in the primary motor cortex M1 of mice was investigated, and whether regulating Sema3G signaling could improve motor dysfunction. An adeno-associated virus type 2 / 9 (AAV-Sema3G, the overexpression sequence is murine NM_001025379.1) connecting the 3×myc tag and a control virus AAV2 / 9-ZsGreen (AAV-Con, control virus) containing green fluorescence were constructed, and the adeno-associated virus overexpressing Sema3G and the control virus were injected into the primary motor cortex M1 of WT male mice at 15 - 20 days after birth. Four weeks after Sema3G overexpression, local ischemia was induced by rose bengal photothrombosis. After the mice regained consciousness, motor-related behavioral tests were started, including the cylinder test and the false foot test ( Figure 3A). The former evaluates and scores whether the mice in the stroke recovery stage have excessive dependence on one forelimb by recording the supporting ability of the forelimb during the standing process of the stroke mice; the latter evaluates the limb coordination and control ability by recording the number of times the stroke mice step into the air within a certain time while walking on the grid. The results of the cup climbing experiment show that on the fifth day after ischemia, compared with the control group mice, the dependence of the mice treated with overexpressed Sema3G on one forelimb is significantly reduced; the results of the grid misstep experiment show that on the seventh day after ischemia, compared with the control group mice, the forelimb coordination and control ability of the mice treated with overexpressed Sema3G is significantly improved( Figure 3 F,G). The results of both behavioral experiments show that on the fifteenth day after stroke prognosis, the motor function of the stroke group mice gradually recovers to the normal level.

[0054] Example 4 Deletion of Semaphorin3G delays the recovery of mouse motor ability

[0055] Different from central nerve injury, the peripheral nervous system has the ability of regeneration and repair after injury. Exploring the effect of Sema3G on the recovery of mouse motor function through the model of sciatic nerve injury (SNI) can further verify the effect of Sema3G on the growth of neuronal axons. A mouse sciatic nerve injury model was constructed (the sciatic nerve was squeezed with small forceps for 10 s and squeezed 3 times), and the damaged sciatic nerve was divided into three segments: the injury site, the proximal part (the tissue near the spinal cord at the upper part of the injury site), and the distal part (the tissue near the gastrocnemius muscle at the lower part of the injury site)( Figure 4 A). The sciatic nerves of vascular endothelial Sema3G knockout mice (Cdh5-Cre; Sema3G f / f ) and control mice (Sema3G f / f ) were damaged, and behavioral analysis was combined to explore whether the deletion of vascular endothelial Sema3G affects the motor ability of experimental mice. The results of the behavioral analysis of the toe extension reflex of mice suggest that: compared with the control group, the recovery of the toe extension ability of Sema3G gene knockout mice is delayed( Figure 4 B,C). In the rotarod test, the time of the gene knockout group mice moving on the rotarod was significantly shorter than that of the control group, indicating that the recovery effect of their motor ability is poor( Figure 4 D,E). Finally, the sciatic nerve function index experiment (SFI, Sciatic function index) was performed on the mice, and the results suggest that the score of Sema3G gene knockout mice is significantly lower than that of the control group mice, indicating that the recovery of the damaged sciatic nerve in the knockout mice is slower( Figure 4F-H). The above research results indicate that Sema3G plays an important role in the recovery process of the injured sciatic nerve, and the knockout of the vascular endothelial Sema3G gene delays the recovery of motor ability in mice. Therefore, the expression of GAP43 (a biomarker for sciatic nerve regeneration) in the sciatic nerve on the 5th day after modeling was detected ( Figure 4 I). The results of immunofluorescence staining and Western blotting showed that: compared with the control mice, the expression of GAP43 in the sciatic nerve of the Sema3G knockout group mice was significantly decreased after sciatic nerve injury, indicating that the deletion of Sema3G slows down the regeneration ability or speed of the sciatic nerve ( Figure 4 J-L). Further, coronal sections of the sciatic nerve tissue of mice 30 days after injury were performed, and it was found that the number of axons per unit area in the proximal coronal plane of each group was similar, while there were significant differences in the number of axons in the distal coronal plane ( Figure 4 M, N). The state of axon regeneration was represented by the ratio of the number of axons per unit area in the distal coronal plane to that in the proximal. The results showed that: compared with the non-knockout group, the number of regenerated axons in the knockout group was significantly reduced ( Figure 4 O). The above results indicate that the knockout of the Sema3G gene delays the regeneration of the injured sciatic nerve and thus delays the recovery of motor ability in mice.

[0056] Example 5 Overexpression of Semaphorin3G in the sciatic nerve promotes the recovery of motor ability in mice

[0057] To explore whether overexpression of Sema3G is beneficial to the regeneration of the injured sciatic nerve, adeno-associated virus ZsGreen of Sema3G (AAV-Con, control virus) and Sema3G (AAV-Sema3G, overexpression virus) were respectively injected into the sciatic nerve of 8-week-old mice by intrathecal injection, and the effective expression of the virus was verified by tissue immunofluorescence two weeks later ( Figure 5 A, B). Immediately afterwards, the effect of Sema3G overexpression on the recovery of motor function in mice was evaluated. First, the results of the mouse toe extension reflex experiment showed that on the 10th and 20th days after sciatic nerve injury, compared with the control group, the ability of the Sema3G overexpressing mice to extend their toes was significantly restored ( Figure 5 C, D). Immediately afterwards, the results of the rotarod test indicated that compared with the control group, on the 10th and 20th days after sciatic nerve injury, the movement time of the Sema3G overexpressing mice on the rotarod was significantly increased ( Figure 5 E). Finally, the sciatic nerve function index (SFI) was used to evaluate morphological parameters. By measuring the toe extension geometric structure of the injured paw and the normal contralateral paw, it was found that the sciatic nerve function of the Sema3G overexpressing mice was almost completely restored 30 days after injury, showing a significantly faster recovery rate ( Figure 5F). In addition, after confirming the overexpression of Sema3G by adeno-associated virus, the regeneration of damaged axons in sagittal sections of the sciatic nerve 5 days after injury was evaluated by immunofluorescence staining. It was found that the number of GAP43-positive axons detected distal to the compression site in Sema3G-overexpressing mice was significantly increased compared with the control group ( Figure 5 G, H). The results of staining the coronal sections of the sciatic nerve of mice 30 days after injury also showed that the number of axons in the distal part of the sciatic nerve of Sema3G-overexpressing mice was significantly increased ( Figure 5 I, J). The above results indicate that overexpression of Sema3G in the sciatic nerve can significantly promote the regeneration of the injured sciatic nerve, thereby promoting the recovery of the motor ability of mice.

[0058] The protection scope of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be conceived by those skilled in the art are included in the present invention, and the appended claims are used as the protection scope.

Claims

1. Application of axon guidance factor Semaphorin3G in the preparation of drugs for improving motor dysfunction.

2. Application of substances that promote the expression of axon guidance factor Semaphorin3G in the preparation of drugs for improving motor dysfunction.

3. The use according to claim 2, wherein the substance that promotes the expression of the axon guidance factor Semaphorin3G is a recombinant vector containing a gene encoding the axon guidance factor Semaphorin3G.

4. The use according to claim 3, characterized in that: The recombinant vector is a viral vector containing a gene encoding axon guidance factor Semaphorin3G.

5. The use according to claim 4, characterized in that: The viral vector is adeno-associated virus.

6. The use according to claim 5, wherein the adeno-associated virus is AAV2 / 9 type.

7. The use according to claim 1 or 2, characterized in that: The motor dysfunction is caused by ischemic stroke.

8. The use according to claim 1 or 2, characterized in that: The medicine also contains other pharmaceutically acceptable excipients.

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