Stem cell exosome composition and application thereof in treating male sexual dysfunction

Abstract

The invention discloses a composition based on an engineered stem cell exosome and application of the composition in treating male sexual dysfunction. The composition comprises a mesenchymal stem cell exosome modified by genetic engineering, and the surface of the mesenchymal stem cell exosome displays a bifunctional fusion polypeptide targeting TbetaR II and LOXL2. According to the fusion polypeptide, TbetaR-PEP and LOXL2-PEP are integrated through a flexible linker, and an HIV-TAT penetrating peptide and a self-assembly motif are introduced, so that nanoparticles are formed, and the half-life period is prolonged. In-vitro experiments show that the inhibition efficiency of the fusion polypeptide on TbetaRII and LOXL2 is obviously superior to that of a single peptide, and the fusion polypeptide can synergistically reverse fibrosis and promote angiogenesis. Animal experiments prove that the exosome loaded with the fusion polypeptide can significantly improve the erectile function of diabetic ED rats. According to the invention, a radical treatment scheme is provided for male sexual dysfunction through double-target cooperation, long-acting delivery and a multi-effect repair mechanism.

Description

Technical Field

[0001] The present application relates to the field of biomedicine, particularly to an exosome composition for treating male sexual dysfunction (ED) and its treatment method. Background Art

[0002] Male sexual dysfunction, particularly erectile dysfunction (ED), is a common disease among men globally, affecting a large number of middle-aged and elderly people. The occurrence of ED is usually related to factors such as vascular dysfunction, nerve damage, and hormonal imbalance. Traditional treatment methods include oral medications (such as sildenafil), hormone replacement therapy, surgical implantation of prostheses, etc. However, these methods have side effects or limited efficacy, and some treatment methods cannot effectively improve the root cause of ED.

[0003] In recent years, stem cell therapy, as a new regenerative medicine approach, has received extensive attention due to its potential in tissue repair, immunomodulation, and angiogenesis. Stem cells secrete exosomes that carry various active molecules (such as miRNAs, proteins, lipids, etc.), which can regulate the cellular microenvironment and promote tissue regeneration. However, current research mainly focuses on the application of stem cell exosomes in wound repair, immunomodulation, etc., and their application in the field of ED is still in the preliminary exploration stage.

[0004] The potential of stem cell exosomes in ED treatment mainly comes from their effects on angiogenesis, nerve repair, and cell signal regulation. Molecules such as miRNAs, proteins, and lipids contained in exosomes can promote local blood flow, repair damaged tissues, and restore sexual function by regulating the expression of target proteins. In the present invention, by optimizing the exosome to load specific resistant polypeptides or antibodies, the TGF-β1 / Smad3 signaling axis is innovatively targeted and regulated, thereby improving the sexual function of ED patients. Summary of the Invention

[0005] The object of the present invention is to provide a stem cell exosome composition and its application in treating male sexual dysfunction.

[0006] Therefore, on the one hand, the present invention discloses a composition of stem cell exosomes, which composition includes exosomes derived from mesenchymal stem cells and polypeptides loaded by the exosomes, wherein the polypeptides include any one of TβR-PEP, LOXL2-PEP, and fusion polypeptides.

[0007] Preferably, the amino acid sequence of the TβR-PEP in the present invention is CGVSLSCHNSGFC.

[0008] Preferably, the amino acid sequence of the LOXL2-PEP in the present invention is CKGGGQYC.

[0009] Preferably, the amino acid sequence of the fusion polypeptide of the present invention is as shown in SEQ ID NO.1.

[0010] In one aspect, the present invention also discloses the use of TβR-PEP in the composition in the preparation of a medicament for treating male sexual dysfunction.

[0011] In one aspect, the present invention also discloses the use of LOXL2-PEP in the composition in the preparation of a medicament for treating male sexual dysfunction.

[0012] In one aspect, the present invention also discloses the use of the fusion polypeptide in the composition in the preparation of a medicament for treating male sexual dysfunction.

[0013] The beneficial effects of the present invention are as follows:

[0014] (1) Dual-target fusion polypeptide design: The fusion polypeptide targets TβRⅡ and LOXL2, synchronously blocking the TGF-β1 / Smad3 fibrosis signaling pathway and the collagen cross-linking process. Experiments show that its inhibitory efficiency on the two targets (IC50 is 3.5 nM and 6.8 nM respectively) is 2-3 times higher than that of the single peptide. The introduction of the HIV-TAT penetration peptide and the self-assembly motif extends the half-life of the polypeptide to 24 hours (only 2-3 hours for the single peptide), and it is targeted and enriched in the corpus cavernosum tissue (enrichment rate >70%).

[0015] (2) Optimization of the exosome delivery system: The membrane surface display of the fusion polypeptide is achieved through the LAMP2 fusion protein, and the targeting efficiency is 4 times higher than that of ordinary exosomes; it is loaded with miR-29b (inhibiting collagen synthesis) and SDF-1α (promoting endothelial cell migration), forming a multi-effect synergistic mechanism of "signal blocking - matrix remodeling - vascular repair".

[0016] (3) Synergistic treatment advantage: In the diabetic ED rat model, the fusion polypeptide-exosome group (1 mg / kg) restored the ICP / MAP ratio to 0.78±0.05 (close to the normal level of 0.82±0.06), the fibrosis area was reduced to 8.9±1.3% (36.7±4.2% in the control group), and the eNOS expression was increased to 1380±110 IOD (480±60 in the control group). The curative effect was significantly better than that of the single-target exosome group (p<0.01).

[0017] (4) Long-acting and safety: The self-assembled nanostructure extends the half-life of the drug to 24 hours, and the curative effect of a single injection lasts for ≥7 days; long-term toxicity experiments show that the liver and kidney function indexes of the treatment group have no difference from those of the normal group (p>0.05).

[0018] (5) Clinical transformation potential: Compared with traditional PDE5 inhibitors (such as sildenafil or polypeptides), the present invention can reverse the pathological basis of ED and radically improve sexual function; the low immunogenicity and targeting of exosomes reduce the risk of systemic side effects. At the same time, the present invention also compared the TβR-PEP, LOXL2-PEP, fusion polypeptide of the present invention with PDE5 inhibitors (sildenafil and polypeptides) loaded exosomes in animal experiments. The results showed that the three polypeptides of the present invention all had better effects on PDE5 inhibitors (sildenafil and polypeptides), and the ICP / MAP ratio was higher than that of PDE5 inhibitors (sildenafil and polypeptides, the ICP / MAP ratios were all <0.6), and there were significant differences. Detailed implementation mode

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0020] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0021] Example 1: Source and preparation of exosomes

[0022] 1. Cell culture: In this example, human umbilical cord mesenchymal stem cells (hUC-MSCs) were used as the source of exosomes. Umbilical cord MSCs have become an ideal choice for exosome extraction due to the following advantages:

[0023] (1) Good secretion characteristics: hUC-MSCs have a high exosome secretion capacity and can release a large amount of exosomes.

[0024] (2) Immunomodulatory ability: Exosomes secreted by hUC-MSCs can regulate immune responses and have anti-inflammatory effects.

[0025] (3) Low immunogenicity: Compared with adult-derived stem cells, umbilical cord MSCs have a lower immune rejection reaction and are suitable for clinical treatment.

[0026] 2. Cell culture steps:

[0027] (1) Cell seeding: hUC-MSCs were isolated from umbilical cord tissue and cultured in DMEM medium containing 10% fetal bovine serum. The cells were seeded in a pre-sterilized T75 culture flask and cultured in a constant temperature incubator at 37°C with 5% CO2.

[0028] (2) Cell passage: When the cells grow to 80% confluence, use trypsin to digest the cells and passage them to maintain cell viability and proliferation ability. When passing to the 4th generation, select cells with stronger exosome secretion ability for the next experiment.

[0029] 3. Exosome extraction method: Ultracentrifugation was used to extract exosomes secreted by hUC-MSCs.

[0030] (1) Medium preparation: Culture hUC-MSCs to the required confluence (80%), then change to serum-free medium (DMEM containing 0% FBS) and continue culturing for 48 hours to promote exosome secretion.

[0031] (2) Collection of culture supernatant: Remove cells by centrifugation and collect the culture supernatant. First, centrifuge the culture supernatant at 3000×g for 10 minutes to remove cell debris and large particle impurities.

[0032] (3) Preliminary isolation of exosomes: Centrifuge the supernatant again at 10,000×g for 30 minutes to further remove larger cell fragments and other impurities. At this time, most of the exosomes precipitate at the bottom of the centrifuge tube.

[0033] (4) Ultracentrifugation to extract exosomes: Transfer the final supernatant to a new centrifuge tube and ultracentrifuge at 100,000×g for 2 hours to concentrate and precipitate the exosomes.

[0034] (5) Resuspend exosomes: Resuspend the precipitated exosomes in PBS buffer and store at -80°C for later use.

[0035] 4. Detection of exosomes

[0036] (1) Determine the concentration of the extracted exosomes by protein quantification method (such as BCA method) or fluorescence detection method (such as Nile Red staining). The detection results are both 1.2×10 9 particles / ml.

[0037] (2) The purity of exosomes was analyzed by nanoparticle tracking analysis (NTA). The results showed that the diameter of exosomes mainly concentrated between 50 - 150 nm and the particle size distribution was uniform, indicating a high purity of the extracted exosomes.

[0038] Example 2: Design and synthesis of TβR-PEP

[0039] 1. Polypeptide sequence design: Based on the binding domain structure of TβRⅡ (Transforming Growth Factor β Receptor Type II), a resistant polypeptide targeting the binding domain of TβRⅡ was designed. By analyzing the binding sites of TβRⅡ, important amino acid residues were selected, and a resistant polypeptide with strong binding affinity was designed. The designed polypeptide sequence is:

[0040] Polypeptide sequence: CGVSLSCHNSGFC; This polypeptide contains a disulfide bond to enhance its stability and the stability of its spatial conformation, and it is named TβR-PEP.

[0041] 2. Synthesis method: The polypeptide synthesis was completed by the solid-phase peptide synthesis (SPPS) method. The specific steps are as follows:

[0042] (1) Selection and pretreatment of resin and amino acids: Rink Amide MH resin was selected as the carrier resin, which is suitable for the synthesis of polypeptides with an amide-type C-terminal carboxyl group. The initial amino acid was Fmoc-L-Cys(Trt) (for the C-terminal cysteine), and the stepwise synthesis was carried out with Fmoc-protected amino acids.

[0043] (2) Synthesis process: The synthesis was carried out using the Fmoc (9-fluorenylmethoxycarbonyl) protection method. After each addition of Fmoc-amino acid, the Fmoc protecting group was removed by 4M piperidine. Each amino acid was activated with DIC (N,N'-diisopropylcarbodiimide) and HOBt (1-Hydroxybenzotriazole) and reacted with the amino acid to form a peptide chain. The addition reaction of each amino acid was controlled within 1 - 2 hours to ensure complete synthesis.

[0044] (3) Formation of disulfide bond: After the polypeptide synthesis was completed, the protecting groups were removed and the solid-phase support was washed. The polypeptide was detached from the resin to obtain a crude peptide. To introduce the disulfide bond, the synthesized polypeptide was dissolved in a buffer solution containing an oxidant (hydrogen peroxide) to induce the formation of disulfide bonds between cysteine residues.

[0045] (4) Deprotection and purification of the polypeptide: The protecting groups were removed by ethyl carbamate and fluoride, enabling the complete deprotection of the polypeptide chain to obtain the full-length peptide chain. The synthesized polypeptide was purified by HPLC, and finally, the target peptide with a purity greater than 95% was obtained.

[0046] 3. Experimental summary: By the solid-phase peptide synthesis method, the resistant polypeptide TβR-PEP targeting the binding domain of TβRⅡ was successfully synthesized, and the polypeptide purity reached over 95%. Its structure and quality were verified by various analytical methods such as HPLC, ensuring the reliability and applicability of the polypeptide in subsequent experiments.

[0047] Example 3: Design and Synthesis of LOXL2-PEP

[0048] LOXL2 (Lysyl Oxidase-Like 2) is an oxidase and a member of the lysyl oxidase family. It is mainly involved in the modification of the extracellular matrix (ECM), especially related to the cross-linking of collagen and elastin. The full name of LOXL2 is lysyl oxidase-like 2, which plays an important role in multiple biological processes, including the structural stability of tissues, cell migration, inflammatory responses, and fibrosis, etc.

[0049] A major cause of ED is vascular dysfunction, usually manifested as the constriction of penile blood vessels and insufficient blood flow. LOXL2 plays a crucial role in the remodeling of vascular smooth muscle cells and endothelial cells. Excessive LOXL2 expression may lead to excessive cross-linking of the extracellular matrix, further exacerbating the rigidity of the blood vessel wall, affecting the vasodilatory ability of blood vessels, resulting in poor blood flow, and thus inducing ED. Due to the key role of LOXL2 in fibrosis, studies have shown that the high expression of LOXL2 may be related to the fibrosis of the corpus cavernosum of the penis. Fibrosis will cause structural changes in the corpus cavernosum, reduce the blood filling volume, and thus affect the erectile function of the penis. By enhancing the cross-linking of the extracellular matrix, LOXL2 may reduce the elasticity and expandability of the corpus cavernosum of the penis, leading to erectile dysfunction. During the erection process, the relaxation and contraction of smooth muscle cells play a key role. LOXL2 may affect the function of smooth muscle by regulating the cross-linking of the extracellular matrix of smooth muscle cells, further affecting the quality and duration of erection.

[0050] The above studies have shown that LOXL2 promotes corpus cavernosum fibrosis by catalyzing the cross-linking of collagen fibers, and its inhibitor can significantly reduce collagen deposition (the inhibition rate is >60% in experiments); for this reason, this study designed a resistant polypeptide LOXL2-PEP (amino acid sequence: CKGGGQYC, targeting the active center of LOXL2) to block its enzymatic activity. The specific synthesis is shown in Example 2.

[0051] Example 4: Design and Synthesis of Fusion Polypeptide

[0052] According to the designs of Example 2 and Example 3, this study fused two polypeptides into one polypeptide, namely the fusion polypeptide. The specific design is as follows: insert the GGGGS flexible linker to separate the two functional domains and maintain the conformational independence of each; add the HIV-TAT penetration peptide (sequence: YGRKKRRQRRR) at the N-terminus to enhance the transmembrane delivery efficiency; introduce the VEWNEMTW hydrophobic sequence at the C-terminus to promote nanoparticle formation and extend the in vivo half-life. The amino acid sequence of the fusion polypeptide after this design is shown in SEQ ID NO.1. The specific synthesis is shown in Example 2.

[0053] Example 5: Applications of Polypeptides and Fusion Polypeptides

[0054] I. Experiment 1: In Vitro Target Binding and Inhibition Experiment

[0055] 1. Immobilization of recombinant proteins: Recombinant human TβRⅡ (100 ng / well) and LOXL2 (100 ng / well) were respectively coated onto 96-well plates and incubated overnight at 4°C.

[0056] 2. Competitive ELISA: Biotinylated TGF-β1 (50 nM) or collagen IV (50 nM) was added as a competing ligand; TGF-β1-PEP, LOXL2-PEP or the fusion polypeptide at gradient concentrations (0.1 - 1000 nM) were respectively added and incubated at 37°C for 1 hour; after washing, streptavidin-HRP was added, and OD450 was measured after color development.

[0057] 3. Data calculation: The half-maximal inhibitory concentration (IC50) and the maximum inhibition rate (Imax) of each polypeptide were calculated.

[0058] 4. Experimental results: The inhibitory efficiency of the fusion polypeptide against both targets was significantly better than that of the single peptide (**p < 0.01**), indicating a dual-target synergistic effect. The specific results are shown in Table 1.

[0059] Table 1 Statistical Results of Detection

[0060]

[0061] II. Experiment 2: LOXL2 Enzyme Activity Inhibition Experiment

[0062] 1. Enzyme reaction system: LOXL2 (10 nM) and collagen IV (1 mg / mL) were incubated in a reaction buffer at 37°C for 24 hours; different treatments (single peptide or fusion polypeptide, final concentration 10 μM) were added.

[0063] 2. Detection of cross-linked products: The collagen cross-linking density (μg / mg) was measured using the hydroxyproline colorimetric method, and the LOXL2 activity was detected by fluorescence method (Ex / Em = 530 / 590 nm).

[0064] 3. Experimental results: The inhibitory effect of the fusion polypeptide on LOXL2 was 1.6 times that of the single peptide, and the collagen cross-linking was significantly reduced. The specific results are shown in Table 2.

[0065] Table 2 Detection Results of LOXL2 Enzyme Activity Inhibition Experiment

[0066]

[0067]

[0068] (*p < 0.01 vs control group; **p < 0.01 vs LOXL2-PEP group)

[0069] III. Experiment 3: Anti-fibrotic cell experiment (HCSMC model)

[0070] 1. Cell treatment: Human cavernous smooth muscle cells (HCSMC) were divided into 5 groups: control group (untreated), TGF-β1 group (10 ng / mL TGF-β1, 48 hours), TGF-β1 + TβR-PEP group (10 μM), TGF-β1 + LOXL2-PEP group (10 μM), TGF-β1 + fusion polypeptide group (10 μM).

[0071] 2. Detection indexes: Western blot was used to detect the protein expressions of α-SMA, Collagen I, and p-Smad3; immunofluorescence was used to observe the cell contractile skeleton (F-actin staining).

[0072] 3. Experimental results: The fusion polypeptide almost completely reversed the fibrosis indexes, which was significantly better than the single peptide (α-SMA inhibition rate: fusion peptide 65% vs TβR-PEP 44% vs LOXL2-PEP 34%). The results are shown in Table 3.

[0073] Table 3 Results of anti-fibrotic cell experiment

[0074]

[0075] (*p < 0.05, **p < 0.01 vs TGF-β1 group)

[0076] IV. Experiment 4: Pro-angiogenesis experiment (HUVEC migration model)

[0077] 1. Transwell migration experiment: HUVEC cells were seeded in the upper chamber of Transwell (serum-free medium); the lower chamber was added with medium containing SDF-1α (50 ng / mL), and single peptide or fusion polypeptide (10 μM) was added respectively; after 24 hours, the cells were fixed, stained with crystal violet, and the number of migrated cells was counted.

[0078] 2. Angiogenesis experiment: HUVEC was seeded in Matrigel matrix, and the formation of lumen (length and number of branches) was observed.

[0079] 3. Experimental results: The pro-angiogenesis effect of the fusion polypeptide was 1.5 - 2 times that of the single peptide, suggesting that the dual-targets synergistically activated the endothelial function. The specific results are shown in Table 4.

[0080] Table 4 Results of pro-angiogenesis experiment

[0081]

[0082] (*p < 0.05 vs control group; **p < 0.01 vs single peptide group)

[0083] V. Summary:

[0084] 1. Dual-target synergy: The inhibitory efficiency of the fusion polypeptide against TβRⅡ and LOXL2 was increased by 2.3-fold and 1.8-fold, respectively;

[0085] 2. Functional complementarity: TβR-PEP blocks the fibrotic signal, and LOXL2-PEP inhibits collagen cross-linking. The combined effect reverses the pathological process;

[0086] 3. Long-acting property: The self-assembled nanostructure extends the half-life to 24 hours (only 2 - 3 hours for the single peptide), and the efficacy of a single injection lasts for ≥7 days.

[0087] Example 6: Exosome-loaded polypeptide and its application

[0088] The exosomes prepared in Example 1 were loaded with the three polypeptides of Examples 2 - 4 by the "ultrasonic method", and the loading efficiency was detected by fluorescence labeling and protein quantitative analysis. The concentration of the polypeptide loaded in the exosomes was adjusted to 1 mg / mL, and the loading efficiency was 82% ± 3.5%. Thus, TβR-exo, OXL2-exo, and fusion polypeptide-exo were formed.

[0089] 1. Experimental animals and grouping

[0090] (1) Animal selection: Male SD rats (body weight 250 - 300 g), purchased from the experimental animal center.

[0091] (2) Grouping: A total of 60 rats were randomly divided into 6 groups, with 10 rats in each group:

[0092] ① Normal control group: Healthy rats without any intervention.

[0093] ② ED model group: Diabetic ED rats induced by STZ, treated with normal saline.

[0094] ③ exo group: Diabetic ED rats, injected with 1 mg / kg exo (exosomes prepared in Example 1) into the corpus cavernosum.

[0095] ④ TβR-exo group: Diabetic ED rats, injected with 1 mg / kg TβR-exo into the corpus cavernosum.

[0096] ⑤ OXL2-exo group: Diabetic ED rats, injected with 1 mg / kg OXL2-exo into the corpus cavernosum.

[0097] ⑥ Fusion polypeptide-exo group: Diabetic ED rats, injected with 1 mg / kg fusion polypeptide-exo into the corpus cavernosum.

[0098] 2. Model construction

[0099] (1) STZ-induced diabetes:

[0100] ① Diabetes induction: A diabetic ED rat model was established by intraperitoneal injection of STZ (60 mg / kg).

[0101] ② Blood glucose detection: 48 hours after injection, the blood glucose level of the rats was detected by a tail tip blood glucose meter. Rats with blood glucose ≥ 16.7 mmol / L were determined to be diabetic rats.

[0102] ③ ED diagnosis: By measuring the erectile function of the rats (ICP / MAP ratio), an ICP / MAP < 0.5 was used as the diagnostic criterion for ED.

[0103] 3. Experimental detection indicators

[0104] ① ICP / MAP ratio: Used to evaluate the erectile function of the rats. An ICP / MAP ratio > 0.5 indicates normal erectile function, and < 0.5 indicates erectile dysfunction.

[0105] ② Masson staining to quantify the area of corporal fibrosis: The degree of corporal fibrosis was detected by Masson trichrome staining, and the fibrotic area was quantified.

[0106] ③ Immunohistochemistry to detect eNOS: Used to evaluate the level of NO synthesized by vascular endothelium in the corpora cavernosa of the rats. NO is a key regulator of erectile function.

[0107] 4. Experimental procedures

[0108] (1) Construction and evaluation of the diabetes model: An STZ-induced diabetes model was established, and rats with a blood glucose level ≥ 16.7 mmol / L and an ICP / MAP ratio < 0.5 were confirmed as the established ED model.

[0109] (2) Drug treatment: Subsequently, the rats were treated with normal saline or different drug combinations according to random grouping.

[0110] (3) Treatment period: The treatment lasted for 4 weeks, with injections once a week.

[0111] (4) Detection

[0112] ① Determination of the ICP / MAP ratio: The ratio between the intracorporal pressure (ICP) and the mean arterial pressure (MAP) was measured using a rectal temperature probe connected to a pressure sensor.

[0113] ②Masson staining: After the rats were sacrificed, the corpus cavernosum penis was removed, fixed and sectioned. The Masson trichrome staining method was used to observe the fibrosis in the corpus cavernosum, and an image analysis software was used to calculate the fibrotic area.

[0114] ③Immunohistochemistry: Immunohistochemical method was used to detect the expression of eNOS in the corpus cavernosum tissue to observe angiogenesis and vascular function.

[0115] 5. Experimental results and data analysis are shown in Table 5 specifically.

[0116] (1) ICP / MAP ratio: The ICP / MAP ratio of rats in the normal control group was 0.82 ± 0.06, indicating normal erectile function. The ICP / MAP ratio of rats in the ED model group was significantly reduced to 0.38 ± 0.04, indicating erectile dysfunction in diabetic ED model rats. Compared with the ED model group, the other 4 treatment groups all had relatively good effects and significant differences; and the effect of the fusion polypeptide-exo group was the best, approaching that of the normal control group (p < 0.01), showing the best curative effect.

[0117] (2) Fibrotic area: The ED model group showed significant corpus cavernosum fibrosis (36.7 ± 4.2%), reflecting severe fibrosis and vascular dysfunction. Compared with the ED model group, the other 4 treatment groups all had relatively good effects and significant differences; and the effect of the fusion polypeptide-exo group was the best, approaching that of the normal control group (p < 0.01), showing the strongest reversal effect.

[0118] (3) eNOS expression: The eNOS expression in the ED model group decreased significantly (480 ± 60), indicating a reduction in NO synthesis, resulting in erectile dysfunction. Compared with the ED model group, the other 4 treatment groups all had relatively good effects and significant differences; and the effect of the fusion polypeptide-exo group was the best, approaching that of the normal control group (p < 0.01), showing the best curative effect.

[0119] Table 5 Summary of detection results

[0120]

[0121] 6. Conclusions and discussions

[0122] The fusion polypeptide-exo group showed significant advantages in improving erectile function, reversing fibrosis and promoting angiogenesis. Its curative effect was close to that of the normal control group and significantly better than that of the TβR-exo group and the LOXL2-exo group; at the same time, the combined treatment groups of the 3 polypeptides and exo were all better than the exo group. The therapeutic effect of the fusion polypeptide-exo group may be related to its simultaneous targeting of TβRⅡ and LOXL2, which can more effectively improve the fibrosis and angiogenesis defects in diabetic ED.

[0123] Although the TβR-exo group and the LOXL2-exo group improved erectile function and angiogenesis to a certain extent, the curative effect was relatively limited compared with the fusion polypeptide-exo group, but both were better than the effect of the single exo group, indicating that the targeting polypeptide had obvious effects.

[0124] Therefore, the treatment strategy of the fusion polypeptide-exo group provides a new and effective means for the treatment of diabetic ED, and it is worthy of further studying its clinical transformation potential.

[0125] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A composition of stem cell exosomes, characterized in that: The composition comprises exosomes derived from mesenchymal stem cells and polypeptides loaded by the exosomes, wherein the polypeptide comprises any one of TβR-PEP, LOXL2-PEP and a fusion polypeptide.

2. The composition according to claim 1, characterized in that The amino acid sequence of the TβR-PEP is CGVSLSCHNSGFC.

3. The composition according to claim 1, characterized in that The amino acid sequence of LOXL2-PEP is CKGGGQYC.

4. The composition according to claim 1, characterized in that The amino acid sequence of the fusion polypeptide is shown in SEQ ID NO.

1.

5. Use of TβR-PEP in the composition as claimed in claim 2 in the preparation of a drug for treating male sexual dysfunction.

6. Use of LOXL2-PEP in the composition according to claim 3 in the preparation of a medicament for treating male sexual dysfunction.

7. Use of the fusion polypeptide in the composition as claimed in claim 3 in the preparation of a drug for treating male sexual dysfunction.

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