Stem cell exosome composition and its application in treating erectile dysfunction

Abstract

The present invention relates to a stem cell exosome composition and its application in treating erectile dysfunction. Specifically, an inhibitory peptide InPDE5-5 polypeptide specifically targeting PDE5 is provided. The polypeptide has good specificity, does not cross-react with PDE6 target, and has low side effects. It can effectively treat erectile dysfunction when used alone or in combination with exosomes, and has good application prospects.

Description

Technical Field

[0001] The present application relates to the biological field, and specifically to a stem cell exosome composition and its application in treating erectile dysfunction. Background Art

[0002] Male erectile dysfunction (MED) refers to the lack of effective and lasting penile erection required for satisfactory sexual intercourse. It is a common male disease. According to the Massachusetts Male Aging Study, the prevalence of MED in 1,290 randomly selected men aged 40 to 70 was (52.0±1.3)%, which means that there are about 18 million MEDs in the United States aged 40 to 70. In 1998, a sexual survey was conducted on 1,582 men aged 40 and above in Shanghai, and the prevalence of MED was as high as 73.1%. At present, there are about 150 million MED patients in the world, accounting for about 20% of the male population.

[0003] The physiological mechanism of penile erection involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO activates guanylate cyclase, leading to an increase in the level of cyclic guanosine monophosphate (cGMP), which relaxes the smooth muscle in the corpus cavernosum and fills the corpus cavernosum with blood. Phosphodiesterase type 5 (PDE5) is a specific cGMP hydrolase in the corpus cavernosum tissue of the penis, which can degrade cGMP and is highly expressed in the corpus cavernosum of the penis. PDE5-I is a highly selective PDE5 inhibitor that inhibits the degradation and inactivation of cGMP, increases the level of cGMP in the smooth muscle of the corpus cavernosum of the penis, and can have the effect of treating ED. Based on this principle, there are currently many oral drugs for the treatment of ED. A study on the relationship between the duration of ED and the use of PDE5-I found that PDE5-I can effectively improve the erectile function of patients with ED. For example, Sonagen applied for a patent in the United States (patent number US5731339) and was approved, mainly claiming to protect a composition (preparation) containing phentolamine mesylate. In 1996, Sonagen applied for a PCT patent (patent number WO96 / 33705), claiming the use of vasodilators such as phentolamine mesylate for the preparation of a pharmaceutical composition for regulating human sexual response. In addition, the drug sildenafil (Viagra, Viagra) is a cGMP-related, specific inhibitor of phosphodiesterase type 5 (PDE5). In 1996, Pfizer of the United States successfully used sildenafil oral therapy to treat MED. Its mechanism of action is: when sexual stimulation causes the release of NO in the corpus cavernosum of the penis, sildenafil selectively inhibits PDE5, thereby maintaining a high concentration of cGMP in the corpus cavernosum, prolonging the relaxation of the penile smooth muscle, increasing the blood supply to the penile smooth muscle of MED patients, and producing a sustained erection effect.

[0004] In addition, the therapeutic prospects of exosomes are a major focus that attracts scholars. Exosomes contain a variety of bioactive substances and can participate in various pathological and physiological processes in the body, such as cell proliferation and differentiation, cell apoptosis, immune regulation, tissue regeneration, and tumorigenesis. Recent studies have also found the therapeutic potential of exosomes in the fields of regenerative medicine, inflammatory diseases, and tumor gene therapy. A recent study compared the effects of adipose stem cells injected into the corpus cavernosum and exosomes isolated and extracted from its culture medium on the erectile function of diabetic ED rats. It was found that the two were equally effective, both of which could upregulate the expression of endothelial cell markers CD31, smooth muscle actin, and anti-apoptotic protein BCl-2, and downregulate the expression of apoptotic protein Caspase-3. By inhibiting cell apoptosis, the regeneration and repair of lesions of the corpus cavernosum and smooth muscle bundles of the penis were obtained, thereby promoting the improvement of ED symptoms in diabetic rats. In another rat diabetic ED model study, in vitro experiments showed that exosomes have the effect of promoting angiogenesis and endothelial cell proliferation, and in vivo experiments confirmed that exosomes have the potential to resist fibrosis and restore erectile function. More importantly, through analysis of exosome components and RNA sequencing, it can be found that exosomes contain more functional miRNAs than stem cells themselves. Studies have shown that the occurrence of diabetic or lipid metabolism-related ED may be related to abnormal expression of cellular miRNAs, such as low miR-126 in serum samples of diabetic patients, and miR-126 can regulate the cell VEGF signaling pathway and is one of the important functional miRNAs for vascular protection. In addition, in the study of exosome treatment of rats with arterial injury ED, it was found that exosomes can stimulate the recruitment, mobilization and differentiation of endogenous stem cells in the cavernous tissue to form new endothelial cells, thereby regenerating and repairing blood vessels and reducing the damage to tissues caused by ischemia and hypoxia, and this promoting effect may also be related to the fact that exosomes secreted by mesenchymal stem cells are rich in VEGF or miR-126. At the same time, they also observed an increase in the content of corpus cavernosum smooth muscle in the experiment, which may benefit from the improvement of the blood flow environment after endothelial repair or because exosomes have the function of resisting muscle fiber apoptosis. In addition to diabetic ED and vascular injury ED, in vivo and in vitro experiments found that exosomes also have an improvement effect on ED caused by cavernous nerve injury, and an important mechanism for the therapeutic effect of exosomes may be that exosomes act as signal molecule carriers and are taken up by cavernous smooth muscle cells through the paracrine pathway, blocking the apoptotic protein Caspase-3-dependent or other apoptotic pathways, reducing the apoptosis rate, restoring the activity of cavernous smooth muscle, and avoiding atrophy and fibrosis caused by denervation. Stem cell exosomes can also increase the expression of neurogenic NO synthase and the synthesis of neurofilaments to a certain extent, and restore the structural function of the dorsal penile nerve and pelvic ganglion to a certain extent.

[0005] In the existing technology, although there are many chemical drugs that can treat ED, and there are also studies on the use of exosomes for the corresponding treatment of ED, there are not enough drugs available for the treatment of ED, especially domestic drugs with better efficacy, which need further development. Summary of the invention

[0006] In view of the defects of the prior art, the present invention provides a stem cell exosome composition and its application in treating erectile dysfunction.

[0007] Specifically, on the one hand, the present invention targets PDE5 and screens a specific inhibitory peptide named InPDE5-5 polypeptide, and the amino acid sequence is shown in SEQ ID NO: 1. The polypeptide has good specificity, no cross-reaction with PDE6 target, and low side effects.

[0008] In another aspect, the present invention also provides use of the InPDE5-5 polypeptide in preparing a pharmaceutical composition for treating erectile dysfunction.

[0009] In another aspect, the present invention also provides a use of mesenchymal stem cell exosomes in preparing a pharmaceutical composition for treating erectile dysfunction.

[0010] Furthermore, the present invention also provides use of a combination of InPDE5-5 polypeptide and mesenchymal stem cell exosomes in the preparation of a pharmaceutical composition for treating erectile dysfunction.

[0011] The compositions of the present invention can be administered orally, buccally or sublingually in the form of tablets, capsules (including soft gel capsules), ovules, elixirs, solutions or suspensions, which may contain flavorings or coloring agents for immediate release, delayed release, modified release, sustained release, controlled release or pulse delivery applications. The compositions of the present invention can also be administered in fast dispersing or fast dissolving dosage forms.

[0012] Such tablets may contain excipients such as microcrystalline cellulose, lactose, sodium citrate, calcium carbonate, calcium hydrogen phosphate and glycine, disintegrants such as starch (preferably corn, potato or tapioca starch), sodium starch glycolate, cross-linked sodium carboxymethylcellulose and certain complex silicates, and granulation binders such as polyvinyl pyrrolidone, hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose (HPC), sucrose, gelatin and gum arabic. In addition, lubricants such as magnesium stearate, stearic acid, glyceryl behenate and talc may be included. The at least one physiologically and / or pharmaceutically acceptable excipient is present in an amount of 95% to 0.2%, preferably 90% to 0.5%, and even more preferably 85% to 1%.

[0013] Solid compositions of similar types may also be used as fillers in gelatin capsules. In this regard, preferred excipients include lactose, starch, cellulose, lactose or high molecular weight polyethylene glycols. For aqueous suspensions and / or elixirs, the compounds of the invention may be combined with various sweeteners or flavorings, coloring agents or dyes, with emulsifiers and / or suspending agents and with diluents such as water, ethanol, propylene glycol and glycerol and combinations thereof.

[0014] Improved release and pulse release dosage forms can contain excipients and other excipients serving as release rate modifiers, which are coated on the main body of the device and / or included in the main body of the device. Release rate modifiers include but are not limited to hydroxypropyl methylcellulose, methylcellulose, sodium carboxymethylcellulose, ethylcellulose, cellulose acetate, polyethylene oxide, xanthan gum, carbomer, ammonium methacrylate copolymer, hydrogenated castor oil, carnauba wax, paraffin, cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, methacrylic acid copolymer and mixtures thereof. Improved release and pulse release dosage forms can contain a kind of release rate modifier excipient or its combination. Release rate modifiers can be present in the dosage form, i.e. in the matrix, and / or on the dosage form, i.e. on the surface or coating.

[0015] Fast dispersing or dissolving dose formulations (FDDFs) may contain the following ingredients: aspartame, acesulfame potassium, citric acid, croscarmellose sodium, crospovidone, diascorbic acid, ethyl acrylate, ethyl cellulose, gelatin, hydroxypropyl methylcellulose, magnesium stearate, mannitol, methyl methacrylate, mint flavor, polyethylene glycol, fumed silica, silicon dioxide, sodium starch glycolate, sodium stearyl fumarate, sorbitol, and xylitol.

[0016] Compositions of the present invention can also be administered parenterally, such as intravenously, intra-arterially, or they can be administered by infusion techniques. For such parenteral administration, they are preferably used in the form of sterile aqueous solution, which may contain other substances, such as enough salts or glucose to make the solution isotonic with the blood. If desired, the aqueous solution should be appropriately buffered (preferably buffered to a pH of 3 to 9). Suitable parenteral preparations are easily prepared under aseptic conditions and are completed by standard pharmaceutical techniques well known to those skilled in the art.

[0017] Further, the at least one physiologically and / or pharmaceutically acceptable excipient is preferably selected from the group comprising the following or selected from the group consisting of the following: diluent, anti-caking agent, disintegrant, binder and mixtures thereof. The diluent is preferably included in the composition in an amount of 2% by weight to 70% by weight, preferably 10% by weight to 60% by weight. Preferably, the diluent is selected from maltodextrin, starch (preferably corn starch), microcrystalline cellulose, sucrose, sorbitol, mannitol, xylitol, calcium hydrogen phosphate, tricalcium phosphate and mixtures thereof. The anti-caking agent is preferably included in the composition in an amount of 0.2% by weight to 7% by weight, preferably 0.5% by weight to 5% by weight. Preferably, the anti-caking agent is selected from magnesium stearate, glyceryl behenate, talc, silicon salt (preferably amorphous silicon dioxide) and mixtures thereof. The disintegrant is preferably included in the composition in an amount of 0.2% by weight to 5% by weight, preferably 0.5% by weight to 4% by weight. Preferably, the disintegrant is selected from sodium amidoglycolate, sodium carboxymethylcellulose, polyvinylpyrrolidone and mixtures thereof. The binder is preferably contained in the composition in an amount of 5 to 60 wt %, preferably 10 to 45 wt %. Preferably, the binder is selected from sucrose, dextrose, mannitol, sorbitol, fructose, microcrystalline cellulose and mixtures thereof.

[0018] Furthermore, the solid composition is preferably in the form of tablets or capsules.

[0019] The composition in tablet solid form preferably comprises: the amount of the formulation is 5% to 40%, preferably 10% to 30%, more preferably 15% to 25%, even more preferably 16% to 22%;

[0020] The at least one physiologically and / or pharmaceutically acceptable excipient is present in an amount of 95% to 60%, preferably 90% to 70%, more preferably 85% to 75%, even more preferably 84% to 78%.

[0021] The composition in tablet solid form most preferably comprises: the amount of the formulation is 5% to 40%, preferably 10% to 30%, more preferably 15% to 25%, even more preferably 16% to 22%; a diluent, preferably starch (more preferably corn starch) and / or maltodextrin, in an amount of 10% to 60%, more preferably 35% to 55%, even more preferably 40% to 50%; an anti-caking agent, preferably glyceryl behenate, a silicon salt (preferably amorphous silicon dioxide) and / or magnesium stearate, in an amount of 0.5% to 5%, more preferably 2% to 4.5%, even more preferably 3% to 4%; a disintegrant, preferably sodium carboxymethylcellulose, in an amount of 0.5% to 4%, more preferably 1% to 3%, even more preferably 1.5% to 2.5%; a binder, preferably microcrystalline cellulose, in an amount of 10% to 45%, more preferably 20% to 40%, even more preferably 25% to 35%.

[0022] Beneficial Effects

[0023] The present invention provides an effective stem cell exosome composition and its application in treating erectile dysfunction. Specifically, it also provides an inhibitory peptide InPDE5-5 polypeptide that specifically targets PDE5. The polypeptide has good specificity, does not cross-react with PDE6 targets, and has low side effects. It can effectively treat erectile dysfunction when used alone or in combination with exosomes, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Effect of InPDE5-5 polypeptide on the expression of nitric oxide synthase

[0025] Figure 2 Effects of each experimental group on cavernous body pressure measurement results DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0027] Example 1 Screening and Identification of PDE5 Inhibitory Peptides

[0028] Based on the spatial structure of human PDE5 protein, six groups of PDE5 inhibitory peptides with higher scores were designed and screened using bioinformatics and molecular docking technology. After artificial synthesis, they were named InPDE5-1, InPDE5-2, InPDE5-3, InPDE5-4, InPDE5-5, and InPDE5-6.

[0029] PDE5 was prepared by conventional methods in the art. Specifically, fresh human platelets (isolated by platelet separator) were centrifuged at 4°C for 30 min. The supernatant was discarded. The precipitated platelets were suspended in 5 ml of ice-cold HEPES buffer. The platelets were crushed by an ultrasonic crusher (60W, 8S crushing, 8S interval, in ice). The crushed solution was centrifuged at a low temperature of 8000 rpm / min for 10 min, and the precipitate was discarded. The supernatant was filtered through a 0.2 μM filter, and the purified PDE5 was separated by an FPLC analyzer. A small amount was taken and the enzyme activity was detected by a direct fluorescent quantitative detection kit for cell phosphodiesterase 5 (PDE5) activity. The remainder was frozen and stored at -80°C.

[0030] 10 μL of 10x buffer (Tris-HCl 500 mmol / L, pH 7.5, 83.0 mmol / LMgCl2, 17.0 mmol / L EGTA), each group of peptides (InPDE5-1, InPDE5-2, InPDE5-3, InPDE5-4, InPDE5-5, InPDE5-6 were 10 mmmol / L, respectively, and the positive control was Sildenafil at a concentration of 10 mmmol / L) and [ 3 H]cGMP (final concentration 5μCi / mL), diluted with water to a final reaction volume of 100μL. After the mixture was incubated at 30°C for 30 minutes, Yttrium PDE SPA scintillation beads (final concentration 20mg / mL) were added and mixed well and placed at room temperature for 20 minutes, and then counted with a counter, and the inhibition rate was calculated based on the count value. The results are shown in Table 1.

[0031] Table 1 The results of the inhibition rate of each group of peptides on PDE

[0032] Components Inhibition rate (%) InPDE5-1 86.84±0.73 InPDE5-2 69.57±0.46 InPDE5-3 76.54±0.57 InPDE5-4 67.48±0.40 InPDE5-5 96.42±1.10 InPDE5-6 88.57±0.74 Sildenafil 98.93±1.34

[0033] As can be seen from Table 1, the InPDE5-5 polypeptide has the best inhibitory activity and has a similar inhibitory effect compared with the positive control group.

[0034] The IC50 values ​​of the InPDE5-5 polypeptide against PDE5 and rat PDE6 were calculated using GraphPad Prism 4.0 statistical software based on the inhibition rate data. The results are shown in Table 2.

[0035] Table 2 Inhibitory activity IC of InPDE5-5 polypeptide against PDE5 and PDE6 50 result

[0036]

[0037]

[0038] As can be seen from Table 2, the InPDE5-5 polypeptide has good inhibitory activity against PDE5, and has no inhibitory effect on PDE6. This shows that the InPDE5-5 polypeptide has good characteristics and overcomes the inhibitory effect of Sildenafil on the PDE6 enzyme, which works in the retina and causes sildenafil users to have visual abnormalities, such as blurred vision or changes in color sensitivity.

[0039] Example 2 Effect of InPDE5-5 polypeptide on cavernous body smooth muscle cells

[0040] Human corpus cavernosum smooth muscle cells, catalog number: bio-105864, were purchased from Biobo Biotech, and cultured and passaged to the third generation using M199 culture medium containing 20% ​​FBS. An equal number of cells were placed in each well of a 96-well plate, and InPDE5-5 polypeptides were added at final concentrations of 10 μg / mL, 50 μg / mL, and 100 μg / mL, respectively. The blank control group was free of polypeptide, and the positive control group was 100 μg / mL of InPDE5-5 polypeptide. The cells were cultured for 24 hours. After the treatment, the cells were collected in an EP tube, and RIPA lysis buffer containing 1% PMSF (protease inhibitor) was added. After mixing, the cells were incubated on ice for 30 minutes, centrifuged at 4°C 12000g for 10 minutes, and the supernatant was aspirated into a new EP tube. A small amount of supernatant was taken for protein quantification. The protein samples were subjected to protein gel electrophoresis. The electrophoresis conditions were concentrated gel for 30 minutes, voltage was 90V, and separation gel was about 1h, voltage was 110V; the PVDF membrane was soaked in methanol for 5 minutes for activation, and the membrane was transferred at 25V to transfer the protein from the gel to the PVDF membrane; the membrane was incubated in the blocking solution at 37°C with the front side facing up for 2 hours with shaking, and then washed 3 times with TBST; the PVDF membrane was immersed in the primary antibody dilution solution of nitric oxide synthase (antibodies purchased from Abcam), incubated overnight at 4°C, and washed 3 times with TBST; the PVDF membrane was immersed in the secondary antibody dilution solution with the front side facing up, incubated at 37°C for 2 hours, and washed 3 times with TBST; the color developer was added and the camera was taken for detection. The results are as follows Figure 1 shown.

[0041] from Figure 1 It can be seen that InPDE5-5 polypeptide has a dose-dependent effect in promoting the expression of nitric oxide synthase, and nitric oxide synthase (nNOS) is an important catalytic substance for releasing and maintaining NO levels in the body. Its amount determines to a certain extent whether sufficient NO can be obtained to initiate and maintain erectile function. This shows that InPDE5-5 polypeptide has a good effect in promoting NO release.

[0042] In addition, the density changes of cells under various concentration conditions were also detected. The results showed that with the increase of concentration, the cell density increased slightly. The 100μg / mL InPDE5-5 polypeptide had a proliferation promoting effect of about 5.3% relative to the control group. Moreover, the cell morphology of each group was normal, and no obvious apoptosis occurred. This shows that the InPDE5-5 polypeptide itself has no obvious toxic side effects, and can also promote cell proliferation to a small extent.

[0043] Example 3 Preparation of adipose-derived mesenchymal stem cell exosomes

[0044] Adipose-derived mesenchymal stem cells (ADHX-C106, Noyan Biotech) were cultured in 75 cm 2The cells were placed in a cell culture flask to allow the stem cells to be in the logarithmic growth phase. When the cell confluence reached 80%, the culture medium was aspirated and the cells were washed twice with PBS. 10 ml of complete culture medium containing 10% exosome-free FBS was added to each flask. After continuing to culture for 24 hours, the culture medium was collected into a centrifuge tube. This culture medium was a conditioned medium rich in exosomes.

[0045] The conditioned medium obtained in the above steps was centrifuged at 4°C, 300g for 10 min to remove cell debris; the obtained supernatant was centrifuged at 4°C, 12,000g for 20 min to remove large cell debris such as apoptotic bodies; the obtained supernatant was filtered with a 0.22μm needle filter to remove microvesicles with a diameter greater than 200nm; the filtered supernatant was placed in an ultracentrifuge tube, centrifuged at 4°C, 100,000g for 70 min, the supernatant was discarded, an appropriate amount of PBS was added to resuspend the precipitate at the bottom of the tube, and stored at -80°C. The morphology of exosomes was identified using a transmission electron microscope. The exosomes extracted in the previous step were dropped onto a 200-mesh sample mesh, left to stand at room temperature for 2 minutes, and excess liquid was absorbed with filter paper. A 20 mg / mL uranyl acetate solution was added to the sample mesh, left to stand at room temperature for 1 minute, the sample was negatively stained, excess liquid was absorbed with filter paper, and the sample mesh was air-dried. The prepared sample was observed under a transmission electron microscope, and it was found that the exosomes were cup-shaped vesicle-like structures with a diameter of about 75-100 nm.

[0046] The exosomes were analyzed by flow cytometry, and the data were analyzed using Flow Software 7.6.1. The results showed that CD29, CD44, CD90 and CD105 were positively expressed in the exosomes, with positive rates of 98.1%, 91.4%, 97.9% and 88.9%, respectively. CD34 and CD45 were negatively expressed, with negative rates of 98.1% and 93.5%, respectively, demonstrating that better exosomes were isolated.

[0047] Example 4 Effects of peptides and exosomes on the efficacy of diabetic erectile dysfunction rats

[0048] All SD rats were intraperitoneally injected with streptozotocin (50 mg / kg) once, and blood was collected from the tail vein one week later to test random blood glucose, and rats with blood glucose ≥16.7 mmol / L were selected as diabetic rats. DED rats were screened out by apomorphine test 12 weeks after streptozotocin injection and used in this experiment.

[0049] Experimental groups: (1) Normal group: normal male SD rats of the same age were injected with 100 μl of PBS through the corpus cavernosum of the penis; (2) DED group: DED rats were injected with 100 μl of PBS through the corpus cavernosum of the penis; (3) Exo group: DED rats were injected with 100 μl of USC-Exo (concentration of 1 μg / μl) through the corpus cavernosum of the penis; (4) Peptide group: DED rats were injected with 20 mg / kg of InPDE5-5 peptide through the corpus cavernosum of the penis; (5) Peptide combined with Exo group: DED rats were injected with 20 mg / kg of InPDE5-5 peptide through the corpus cavernosum of the penis, and then injected with 100 μl of USC-Exo (concentration of 1 μg / μl) 30 minutes later; (6) Positive control group: injected with 20 mg / kg of Sildenafil; 5 rats in each group, and the exosomes were the exosomes prepared in Example 3.

[0050] Corpus cavernosum pressure measurement to detect erectile function: that is, after 4 weeks of corpus cavernosum injection treatment, all rats were anesthetized and fixed by intraperitoneal injection of sodium pentobarbital (30 mg / kg), the main pelvic ganglia and cavernous nerves of the rats were exposed, and bipolar electrodes were placed on the surface of the main ganglia; then the right penile crus was exposed by incision, and a 23G butterfly needle connected to a PE50 catheter was inserted into the right penile crus and connected to a pressure transducer. The left common carotid artery was exposed, and another PE50 catheter was inserted and connected to another pressure transducer after the common carotid artery was incised. A multi-channel physiological signal recorder was used to continuously monitor and record the maximum intracavernosal pressure (ICPmax) and mean arterial pressure (MAP), and ICPmax / MAP was calculated. The electrode stimulation parameters were: voltage 5V, frequency 20Hz, stimulation wave width 5ms, duration 1min, and 5min interval between two stimulations. The results are as follows: Figure 2 shown.

[0051] The results of cavernous pressure measurement are as follows Figure 2 The results showed that the ICPmax / MAP of DED rats was significantly lower than that of normal rats (P<0.05), while the ICPmax / MAP levels of DED rats after treatment with Exo or peptides or the combination of the two were significantly increased compared with the model group (P<0.05). In particular, the peptide group had a better therapeutic effect than the exosome group alone, and after the combined treatment of peptides and exosomes, its ICPmax / MAP was even higher than that of the normal group, which fully demonstrated that the combined treatment of peptides and exosomes can significantly synergistically improve erectile function and has a significant therapeutic effect.

[0052] When implementing or testing the embodiments of the present invention, optional methods and materials similar or equivalent to the methods and materials described in this specification may be used, and preferred methods, devices, and materials are described in this specification. However, before describing the materials and methods of the present invention, it should be understood that the specific size, shape, dimensions, materials, methods, means, etc. described in this specification may be changed according to conventional experimental methods and optimization purposes, and therefore the present invention is not limited thereto. It should also be understood that the technical terms used in this specification are only used to illustrate specific types or embodiments and are not used to limit the scope of the present invention, which is limited only by the scope of the appended claims.

Claims

1. An inhibitory peptide specifically targeting PDE5, characterized in that It is named InPDE5-5 polypeptide, and its amino acid sequence is shown in SEQ ID NO:

1.

2. Use of the InPDE5-5 polypeptide as claimed in claim 1 in the preparation of a pharmaceutical composition for treating erectile dysfunction.

3. Use of the combination of InPDE5-5 polypeptide and mesenchymal stem cell exosomes as claimed in claim 1 in the preparation of a pharmaceutical composition for treating erectile dysfunction.

4. The use according to claim 3, characterized in that The erectile dysfunction is diabetic erectile dysfunction.

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