Skip to main content
NCBI home page
Sexual Medicine logoLink to Sexual Medicine
. 2025 Oct 14;13(5):qfaf080. doi: 10.1093/sexmed/qfaf080

Angiotensin (1-7) decreases the fibrotic process by modulating the TGF-β1/AKT pathway in rat corpus cavernosum smooth muscle cells

Yi Xu 1,✉, Yifang Lu 2, Geling Liu 3, Chen Wang 4, Shuo Tian 5, Hongzhen Xiao 6, Weijuan Li 7
PMCID: PMC12526949  PMID: 41103813

Abstract

Background

Hyperglycemia induces the development of cavernosa atherosclerosis and fibrosis, and transforming growth factor-β1 (TGF-β1) plays an important role in the induction, promoting fibrosis in corporal tissue, which replaces the normal corpora cavernosa with fibrotic tissue.

Aim

This study explored the role of Angiotensin (1-7) (Ang 1-7) and the regulatory mechanism underlying fibrosis in the corpora cavernosa.

Methods

Primary rat corpus cavernosum smooth muscle cells (CCSMCs) were cultured under normal and high glucose (HG) with or without Ang 1-7. The protein levels of TGF-β1, Collagen I, TGF-β receptor-I (TβRI), and caveolin-1 (Cav-1) were evaluated by western blotting. Reactive oxygen species (ROS) and peroxynitrite (ONOO-) levels in cell culture supernatants were measured by enzyme-linked immunosorbent assay. Intracellular calcium content was determined by flow cytometry.

Outcomes

High glucose significantly increased the protein levels of TGF-β1 and Collagen I, triggered oxidative stress, modulated the AKT signaling pathway, and elevated intracellular calcium ion levels in CCSMCs. Angiotensin (1-7) treatment significantly attenuated HG-induced adverse effects in CCSMCs.

Results

The protective effects of Ang 1-7 against fibrosis in HG-exposed CCSMCs were associated with the downregulation of TGF-β1 levels, accompanied by the attenuation of oxidative stress. The Ang1-7-induced effects in CCSMC cells are mediated through the inhibition of the TGF-β1/AKT signaling pathway.

Clinical Translation

Our studies provide new insights into the critical role of the TGF-β1/AKT signaling pathway in CCSMCs, identifying it as a potential therapeutic target for treating patients with erectile dysfunction.

Strengths and Limitations

Angiotensin (1-7) is a unique peptide of the renin–angiotensin system with substantial therapeutic potential. This study assessed the therapeutic effect of Ang 1-7 on the fibrotic process and provided new insights for clinical applications. The clinical formulation, drug stability, and in vivo bioactivity of Ang-1-7 remain to be fully investigated.

Conclusion

Angiotensin (1-7) exerts a protective effect on CCSMCs under HG conditions by modulating the TGF-β1/AKT signaling pathway.

Keywords: Angiotensin (1-7), diabetes mellitus, fibrosis, TGF-β1, oxidative stress, calcium ion levels

Introduction

Hyperglycemia is one of the most critical risk factors for the development of erectile dysfunction (ED).1,2 Approximately 50% of men with diabetes reported some degree of ED within 10 years of their diagnosis.3 The efficacy of current treatments for ED is not ideal. The pathogenesis of diabetes mellitus–induced erectile dysfunction (DMED) is complex.4 Hyperglycemia induces various functional and structural alterations in the corpora cavernosa, including increased oxidative stress and impaired endothelial function, resulting in the development of cavernosa atherosclerosis and fibrosis, which lead to functional loss and degenerative changes in the corpora.5,6 Cavernosa fibrosis is characterized by extracellular matrix (ECM) deposition after chronic damage to the internal structure. This results in limited smooth muscle relaxation, causing arterial insufficiency and venous occlusion dysfunction, eventually leading to ED.7–10

Transforming growth factor-β1 (TGF-β1) is a key contributing factor in the pathogenesis and progression of fibrosis-related diseases.11–13 After activation, TGF-β1 binds to activated Smad protein to form a complex and promotes the deposition of ECM.14 TGF-β1/Smad pathway activation was observed in the corpus cavernosum of rats with bilateral cavernous nerve injury.15 TGF-β1 also exerts its biological effects through non-Smad pathways, such as the MAPK pathway, PI3K-Akt pathway, and Wnt pathway.16–18 Long-term high glucose (HG) exposure stimulates the production of TGF-β1, which is critical in the process of cavernous fibrosis.19 Oxidative stress is another key factor that promotes the fibrosis of cavernous tissues.20 TGF-β1 can increase the production of reactive oxygen species (ROS) and cause excessive accumulation of collagen and other ECM proteins that ultimately lead to reduced tissue elasticity and compliance.21 The endocytosis of TGF-β receptors, mainly through caveolae-mediated internalization, is a key regulatory mechanism in signal transduction. Pulmonary fibrosis is linked to the reduced protein levels of caveolin-1 (Cav-1) and activated TGF-β1/Smad3 signaling through the autophagy pathway.22 Treatment of cardiofibroblasts with JQ1, a bromodomain and extra-terminal (BET) protein inhibitor, reversed the expression of Cav-1 and modulated TGF-β1 signaling.23

Angiotensin (1-7) (Ang 1-7) is an anti-fibrotic factor involved in diabetes-induced structural changes of several organs such as the heart, lungs, kidneys, and liver.24–26 Angiotensin (1-7) was shown to suppress the ROS-dependent PI3K/Akt signaling pathway, inhibiting the angiotensin II-induced proliferation and migration of vascular smooth muscle cells and fibrosis reduction.27 One study showed that Ang 1-7 exhibited cardioprotective potential by reducing the level of fibrosis in the right ventricle in a rat heart failure model.25 Another report found that the Ang1-7/Mas axis upregulated p62 levels to restore Nox4-Nrf2 redox homeostasis, thus delaying the progression of lung fibrosis.28 Our previous study showed that Ang 1-7 improved erectile function and suppressed oxidative stress through the MAS/Akt pathway.29 Based on these findings, we speculate that the beneficial effect of Ang 1-7 on erectile function might also involve the inhibition of penile fibrosis. However, the effect of Ang 1-7 in fibrosis of the penile cavernosa has not been investigated.

This study investigated the role and regulatory mechanism of Ang 1-7 in corpus cavernosum smooth muscle cells (CCSMCs), with the aim of gaining further insights into the role of key molecules and pathways in ED pathogenesis.

Materials and methods

Cell culture

Rat primary CCSMCs (iCell Bioscience Inc., Shanghai, China) were maintained in Dulbecco’s modified Eagle’s medium (DMEM) containing 5.5 mmol/L glucose supplemented with 10% fetal bovine serum (FBS), streptomycin (0.1 mg/mL), and penicillin (0.1 mg/mL). The cells were maintained at 37°C in a humidified incubator with 5% CO2. Corpus cavernosum smooth muscle cells were treated with HG DMEM (DMEM containing 25 mmol/L glucose) for 48 h. Cells passaged fewer than 5 times were used in all experiments.

Drug treatment

Angiotensin (1-7) (Bachem, Bubendorf, Switzerland) was dissolved in PBS and used at a concentration of 10-5 mol/l.29 Methyl-β-cyclodextrin (MβCD, Merck, Damstre Tower, Germany), an antagonist of Cav-1 function, was dissolved in PBS and used at a concentration of 10 μg/mL.30 LY294002 (MCE, Shanghai, China), an Akt pathway inhibitor, was dissolved in sterile dimethyl sulfoxide (DMSO; Sigma-Aldrich, MO, USA) and used at a concentration of 20 μM.31 The concentration of DMSO did not exceed 0.1%. The cells were treated for 48 h; after 24 h, the medium was replaced with fresh drug-containing medium.

Western blot analysis

Corpora cavernosa tissues were minced and added to RIPA buffer. The samples were subjected to sonication followed by centrifugation. The total protein concentration of the supernatant was determined with a BCA assay. Equal amounts of protein samples (30 μg) in loading buffer were separated by SDS-polyacrylamide gel electrophoresis and transferred to a polyvinylidene fluoride membrane. The membrane was blocked in TBST (10 mM Tris-HCl, pH 7.5, 0.1 M NaCl, 0.1% Tween 20) plus 5% non-fat dry milk (Bio-Rad) and then incubated with the following primary antibodies overnight: TGF-β1 (1:1000, Abcam, Cambridge, UK), Cav-1 (1:1500, GTX108807, GeneTex, Irvine, CA, USA), TGF-β receptor-I (TβRI) (1:1000, Abcam), AKT (1:2500, Proteintech, Wuhan, China), p-AKT (Ser 473) (1:3000, Proteintech), and Collagen I (1:3000, Proteintech). The membranes were then incubated with the appropriate secondary antibodies (1:5000, Proteintech) at room temperature for 1.5 h. Three 10-min washes with TBST were performed between each step. Immunoreactive bands were visualized using an enhanced chemiluminescence system. Band density was measured using ImageJ software and normalized to that of β-actin (15 000, Proteintech).

Measurement of ROS and ONOO - levels

CCSMCs were seeded in 6-well plates; after 48 h, culture supernatants were harvested. Intracellular ROS was detected using a dihydroethidium probe (Jiancheng Bioengineering Institute, China) following the protocol of the cellular ROS assay kit. The levels of peroxynitrite (ONOO-) were determined by ELISA (BestBio Biotechnology, Shanghai, China) following the manufacturer’s instructions.

Measurement of cellular calcium levels

Corpus cavernosum smooth muscle cells were washed with an indicator-free medium (HBSS) 3 times, loaded with the Ca2+-sensitive dye Fura 3-AM (3 μmol/L) (Thermo Fisher Scientific) at 37°C for 30 min, and washed with 1 mL of HBSS. The concentration of Ca2+ was calculated by fluorescence-activated cell sorting (Thermo Fisher, USA).

Statistical analysis

Statistical analysis was performed using SPSS 23.0 statistical software (IBM, USA). All data were evaluated using 1-way analysis of variance (ANOVA). Data are expressed as mean ± SEM. Statistical significance was set at P < .05.

Results

The effects of Ang 1-7, MβCD, and LY294002 on TGF-β1 and Collagen I protein levels under HG conditions

We first measured the protein levels of TGF-β1 in CCSMCs following HG treatment. As shown in Figure 1A and B, TGF-β1 levels were significantly higher in the HG treatment group compared with the control group, and this induction was reduced by Ang 1-7 treatment (P < .05). Angiotensin (1-7) inhibited TGF-β1 expression in a concentration-dependent manner, with the greatest inhibition observed at 10−5. mol/L (Figure 1D, P < .05), consistent with our previous findings.29 Treatment with MβCD, an antagonist of Cav-1 function, did not significantly attenuate the HG-induced increase in TGF-β1 expression. Cotreatment of LY294002, an Akt pathway inhibitor, together with Ang 1-7 did not significantly affect the HG-induced increase in TGF-β1 protein levels.

Figure 1.

Figure 1

Open in a new tab

High glucose upregulated the protein levels of TGF-β1 and Collagen I in CCSMCs. (A) Western blot analysis of TGF-β1 and Collagen I. (B) Quantitative analysis of TGF-β1 levels. (C) Quantitative analysis of Collagen I levels. (D) Dose–response effect of Ang 1-7. Each column corresponds to the mean ± standard error of the mean of 3 independent experiments. Control: Cells were grown in regular DMEM. HG: Cells were cultured in high-glucose DMEM for 48 h. HG + MβCD: Cells were preincubated with MβCD for 30 min and cultured in high-glucose DMEM for 48 h. HG + Ang 1-7: Cells were preincubated with angiotensin 1-7 for 30 min and then cultured in high-glucose DMEM for 48 h. HG + Ang 1-7 + MβCD: Cells were preincubated with MβCD for 30 min, incubated with Ang 1-7 for 30 min, and cultured in high-glucose DMEM for 48 h. HG + Ang 1-7 + LY294002: Cells were preincubated with LY294002 for 30 min, incubated with Ang 1-7 for 30 min, and cultured in high-glucose DMEM for 48 h. *P < .05 vs. control; #P < .05 vs. HG group; &P < .05 vs. HG + Ang1-7 group.

Cells cultured in HG conditions also showed significantly increased Collagen I expression, and this effect was attenuated by Ang 1-7 treatment (Figure 1A and C). Notably, LY294002 significantly attenuated the Ang1-7-induced decrease in Collagen I expression (P < .05). However, MβCD did not significantly affect Collagen I expression under HG conditions.

HG culture conditions led to the decrease of Cav-1 and TβRI in CCSMCs

We next examined the levels of Cav-1 in CCSMCs following HG treatment. Our results revealed that cells cultured in HG conditions showed significantly reduced Cav-1 expression (Figure 2A and B). Angiotensin (1-7) and MβCD co-treatment alleviated the effect induced by HG (P < .05). However, MβCD or LY294002 cotreatment together with Ang 1-7 did not alter the Cav-1 protein levels under HG conditions.

Figure 2.

Figure 2

Open in a new tab

High glucose treatment led to a decrease in the protein levels of Cav-1 and TβRI. (A) Western blot analysis of Cav-1 and TβRI. (B) Quantitative analysis of Cav-1. (C) Quantitative analysis of TβRI. Each column corresponds to the mean ± standard error of the mean of 3 independent experiments. *P < .05 vs. control; #P < .05 vs. HG group; &P < .05 vs. HG + Ang1-7 group.

TβRI is localized to caveolae in the cell membrane. Activated TGF-β1 specifically binds to TβRI and recruits downstream proteins, which is critical for tissue fibrosis. We observed a significant decrease in TβRI protein levels in CCSMCs cultured under HG conditions (Figure 2A and C). Methyl-β-cyclodextrin alone did not alter TβRI protein levels under HG conditions. In contrast, Ang 1-7 restored TβRI protein levels to those of controls, while co-treatment of LY294002 with Ang 1-7 prevented this effect.

Ang 1-7 reversed the inhibitory effect of HG on the phosphorylation levels of Akt

We found that cells cultured in HG conditions showed decreased phosphorylated Akt levels (Figure 3A and B). Angiotensin (1-7) significantly reversed this decrease induced by HG (P < .05), and the Akt antagonist LY294002 abolished the effect of Ang 1-7 treatment. Methyl-β-cyclodextrin treatment did not significantly impact Akt phosphorylation. These results suggest that Ang 1-7 may exhibit anti-fibrotic effects by altering the Akt signaling pathway.

Figure 3.

Figure 3

Open in a new tab

Ang 1-7 reversed the inhibitory effect of HG on the phosphorylation levels of Akt. (A) Western blot analysis of p-AKT and AKT. (B) Quantitative analysis of p-AKT levels. AKT phosphorylation was calculated as a percentage of total AKT. Each column corresponds to the mean ± standard error of the mean of 3 independent experiments. *P < .05 vs. control; #P < .05 vs. HG group; &P < 0.05 vs. HG + Ang1-7 group.

Ang 1-7 suppressed HG-induced oxidative stress

We found that cells cultured in HG conditions showed significantly increased ROS and ONOO- levels, and Ang 1-7 treatment reversed this effect (Figure 4). Methyl-β-cyclodextrin treatment partially counteracted the effect of HG and Ang 1-7 on ROS and ONOO-. This suggests that Cav-1 is involved in oxidative stress and the function of Ang 1-7 in rebalancing oxidative stress levels under HG conditions.

Figure 4.

Figure 4

Open in a new tab

Ang 1-7 treatment suppressed oxidative stress induced by high glucose in cultured CCSMCs. Quantification of oxidative stress indicators in the culture supernatant by enzyme-linked immunosorbent assay. (A) ONOO- levels in the indicated groups. (B) ROS levels in the indicated groups. Each column represents the mean ± standard error of the mean (n = 8) of 3 independent experiments. *P < .05 vs. control; #P < .05 vs. HG group; &P < .05 vs. HG + Ang1-7 group.

Ang 1-7 downregulated the intracellular calcium ion levels induced by HG

Finally, we examined whether Ang 1-7, MβCD, and LY294002 impacted the calcium ion levels in CCSMCs under HG conditions. We found that HG significantly increased calcium ion levels, and this effect was decreased by Ang 1-7 treatment (Figure 5). LY294002 significantly countered the effect of Ang 1-7, resulting in increased calcium ion levels. Methyl-β-cyclodextrin alone did not cause a significant change in calcium ion levels under HG conditions. Co-treatment of MβCD treatment with Ang 1-7 caused a slight increase in the calcium ion levels compared with Ang 1-7 alone but did not reach a significant difference. These results indicate that Ang 1-7 treatment may play a dominant role in the reduction of calcium ion levels via the AKT pathway in CCSMCs.

Figure 5.

Figure 5

Open in a new tab

Ang 1-7 attenuated the increase in intracellular calcium levels induced by high glucose. Each column represents the mean ± standard error of the mean of 3 independent experiments. *P < .05 vs. control; #P < .05 vs. HG group; &P < .05 vs. HG + Ang1-7 group.

Discussion

While fibrosis and oxidative stress in the corpus cavernosum are generally recognized as the pathogenesis of diabetes-associated ED,32,33 the underlying pathogenic mechanisms are not fully understood. The present study showed that HG culture conditions significantly increased the protein levels of TGF-β1 and Collagen I and accelerated oxidative stress, accompanied by altering the AKT signaling pathway and elevating intracellular calcium ion levels in CCSMCs. Importantly, targeting fibrosis with Ang 1-7 significantly attenuated HG-induced adverse effects, including decreasing TGF-β1 and Collagen I, reducing oxidative stress and calcium ion levels in CCSMCs. Notably, inhibition of AKT signaling with LY294002 abolished the effect of Ang 1-7, indicating that Ang 1-7 exerts its effects through the AKT signaling pathway under HG conditions. Our studies highlight the critical role of Ang1-7-regulated AKT signaling pathway in mediating its anti-fibrotic effects.

Tissue fibrosis constitutes a significant health problem, including ED pathogenesis associated with uncontrolled inflammation. Critical signaling cascades, initiated by TGF-β, trigger profibrotic reactions, leading to pathological processes such as inflammation and fibrosis. TGF-β contributes to the pathogenic overproduction of ECM components in a wide spectrum of fibrotic disorders, including fibrotic renal milieu.34 TGF-β1 exerts its effects through both Smad-dependent and non-Smad pathways, and Smad3 signaling, in particular, plays a critical role in fibrotic and vascular remodeling processes, including those seen in pulmonary fibrosis and in response to Ang 1-7 treatment.35 Our study focused specifically on Cav-1 because of its established role in modulating TGF-β receptor internalization and non-Smad signaling cascades, such as the MAPK and PI3K-Akt pathways, which are particularly relevant under conditions of ED. While Smad3 signaling is clearly important, our primary objective was to investigate the Cav-1-associated pathways under oxidative or diabetic stress, which are known to strongly activate non-Smad mechanisms. Analyses of Smad3 activation in future studies could expand our understanding of TGF-β signaling.

Inhibition or neutralization of TGF-β was shown to attenuate excessive ECM deposition and ameliorate renal fibrosis in animal models.36 TGF-β interacts with 2 TGF-β receptors (TβRs), type I and type II receptors, to regulate downstream signaling. TGF-β receptors can be internalized through multiple endocytic pathways, including both caveolae-mediated (Cav-1-dependent) and clathrin-mediated endocytosis. The selected route of internalization influences downstream signaling, with clathrin-mediated uptake typically promoting Smad activation and pro-survival signals, whereas caveolar internalization is often linked to receptor degradation or inhibitory signaling pathways.37–39 Razani et al. demonstrated that TβRI localizes to caveolae and Cav-1 binds to TβRI through its scaffolding domain and inhibits its activity.40 Cav-1 is also involved in regulating ErK1/2, the AKT pathway, and eNOS activity.41 Evidence has shown that Cav-1 decreased the actions of TGF-β1 through mediating internalization and degradation of TGF-β1Rs, and the deficiency of Cav-1 is very important in inducing lung fibrosis.42 These results illustrate that TβRI in the cell membrane serves as the regulator of TGF-β signaling through its interaction with caveolae. Our current study focused on Cav-1 expression and localization and found that MβCD down-regulated the expression of Cav-1 and TβRI in CCSMCs under HG conditions. In the context of endothelial dysfunction, particularly under conditions of oxidative stress or diabetes, it is plausible that clathrin-coated pits contribute to TGF-β receptor trafficking and signaling, potentially promoting fibrotic or pro-hypertrophic responses through Smad-dependent pathways. Further investigation of the role of clathrin-mediated internalization may provide a more comprehensive understanding of TGF-β signaling regulation during ED pathogenesis.

Several studies demonstrated the anti-fibrosis effects of Ang 1-7 in multiple tissues. Min et al. revealed that Ang 1-7 exerted antifibrotic effects by inhibiting TGF-β1-induced lung fibroblast differentiation, inflammation, and fibrosis in lung tissue.28 Rodrigo et al. reported that Ang 1-7 treatment reduced penile fibrosis associated with the attenuation of oxidative stress.43 Angiotensin (1-7) exhibits cardio-protective and anti-fibrotic potential through intracellular signaling in hypertrophy pathogenesis.25 One study reported a marked increase of fibrous tissue in the corpus cavernosum of Mas receptor gene–deleted mice.44 Chronic treatment with Ang 1-7 produced a significant reduction in the penile fibrosis of hypercholesterolemic mice.43

The mechanisms underlying the Ang1-7-induced antifibrotic protection in the penis are still poorly understood. Angiotensin (1-7) exerts antifibrotic effects through the attenuation of cytokine signaling cascades, inhibition of MAPK signaling cascades, and a reduction in oxidative stress.25,27 Our previous study45 revealed that Ang 1-7 suppresses oxidative stress and downregulates intracellular Ca2+ levels by regulating the Cav-1–eNOS interaction in rat VSMCs cultured in an HD-containing medium. To explore the key molecules and signaling pathways in CCSMCs related to ED pathogenesis, we investigated the mechanisms of the Ang1-7-induced antifibrotic effects. We found that the protective effects of Ang 1-7 against fibrosis in cultured CCSMCs in the presence of HG were associated with the downregulation of TGF-β1 levels, accompanied by the attenuation of oxidative stress. Our study also revealed the roles of both Cav-1 and TGF-β1 signaling in regulating ECM synthesis. Angiotensin 1-7 may reduce ECM by inhibiting TGF-β1 activity through the Akt/Cav-1/TβRs pathway, and the Cav-1 molecular network is not indispensable to prevent ECM formation. Our current work aimed to extend the mechanistic understanding of fibrosis in the corpora cavernosa by focusing specifically on SMCs, thereby dissecting the direct effects of Ang 1-7 on this cell population and its associated molecular pathways, independent of paracrine influences. This approach enabled us to clearly characterize signaling mechanisms within SMCs. While the role of Ang 1-7 in diabetic ED has been previously reported, our study uniquely demonstrates its concentration-dependent anti-fibrotic effect in the corpora cavernosa. A comprehensive understanding of the bioavailability, half-life, and tissue distribution of Ang 1-7 will be essential for translating these findings into a clinically relevant framework. Our findings serve as a foundational step toward future in vivo studies, including functional assessments such as intracavernous pressure measurements and cavernosal nerve stimulation. These findings provide new mechanistic insights that may inform and refine future therapeutic strategies. Given the critical role of endothelial cells and neural inputs in erectile function, we plan to implement co-culture systems or organotypic models incorporating endothelial and/or neuronal components in our next studies. We will also explore in vivo models to evaluate how these cell populations interact with Ang 1-7 treatment under more physiologic and pathological conditions.

Conclusion

Our study demonstrates that HG significantly enhances the protein levels of TGF-β1 and Collagen-1, causes oxidative stress, alters AKT signaling activity, and increases intracellular calcium ion levels in CCSMCs. Notably, Ang 1-7 treatment significantly diminishes HG-induced detrimental effects in CCSMCs. Furthermore, the Ang1-7-induced effects in CCSMC cells are through the TGF-β1/AKT signaling pathway. Our studies provide fundamental evidence for the potent impact of Ang1-7 on TGF-β1/AKT signaling in CCSMCs as promising targets for treating patients with ED.

Acknowledgments

The authors would like to thank Professor Ying Wang for the technical assistance. We also like to thank Medjaden Inc. for scientific editing of this manuscript.

Contributor Information

Yi Xu, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Yifang Lu, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Geling Liu, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Chen Wang, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Shuo Tian, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Hongzhen Xiao, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Weijuan Li, First Department of Endocrinology, Tangshan Gongren Hospital, Tangshan City, Hebei Province, 063000, China.

Author contributions

Y.X. and G.L. conceived and designed the study; C.W. analyzed the data and wrote the manuscript; S.T., H.X., Y.L., and W.L. collected samples and carried out the experiments. All authors have read and approved the final manuscript.

Funding

This study was supported by the Scientific Research Fund of Hebei Health Commission [20201491].

Conflicts of interest

None declared. The authors have no conflicts of interest.

Data availability

The datasets analyzed in the present study are available from the corresponding author upon reasonable request.

References

  • 1. Weldesenbet  AB, Kebede  SA, Tusa  BS. Prevalence of erectile dysfunction and its associated factors among patients with diabetes in Ethiopia: a systematic review and meta-analysis. J Int Med Res. 2021;49(2):030006052199331. 10.1177/0300060521993318. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2. Corona  G, Isidori  AM, Aversa  A, et al.  Male and female sexual dysfunction in diabetic subjects: focus on new antihyperglycemic drugs. Rev Endocr Metab Disord. 2019;21(1):57-65. 10.1007/s11154-019-09535-7. [DOI] [PubMed] [Google Scholar]
  • 3. McMahon  CG. Current diagnosis and management of erectile dysfunction. Med J Aust. 2019;210(10):469–476. 10.5694/mja2.50167. [DOI] [PubMed] [Google Scholar]
  • 4. Prieto  D. Physiological regulation of penile arteries and veins. Int J Impot Res. 2008;20(1):17–29. 10.1038/sj.ijir.3901581. [DOI] [PubMed] [Google Scholar]
  • 5. Kaltsas  A, Zikopoulos  A, Dimitriadis  F, et al.  Oxidative stress and erectile dysfunction: pathophysiology, impacts, and potential treatments. Curr Issues Mol Biol. 2024;46(8):483-512. 10.3390/cimb46080521. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6. Kurt  HA, Demirci  E, Alan  C. Endothelial dysfunction and ischemia-modified albumin levels in males with diabetic and nondiabetic erectile dysfunction. Dis Markers. 2022;2022(0):3661822. 10.1155/2022/3661822. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7. Luo  PY, Zou  JR, Chen  T, et al.  Autophagy in erectile dysfunction: focusing on apoptosis and fibrosis. Asian J Androl. 2025;27(2):166–176. 10.4103/aja202433. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8. Zhou  X, Song  L, Cong  R, et al.  A comprehensive analysis on the relationship between BDE-209 exposure and erectile dysfunction. Chemosphere. 2022;308(Pt 3):136486. 10.1016/j.chemosphere.2022.136486. [DOI] [PubMed] [Google Scholar]
  • 9. Zou  H, Zhang  X, Chen  W, et al.  Vascular endothelium is the basic way for stem cells to treat erectile dysfunction: a bibliometric study. Cell Death Dis. 2023;9(1):143. 10.1038/s41420-023-01443-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10. Zhang  Q, Xu  RN, Lü  BD, Huang  WJ. Research progress on penis cavernosa fibrosis. Zhonghua Nan Ke Xue. 2023;29(4):358–363. [PubMed] [Google Scholar]
  • 11. Daud  T, Roberts  S, Zounemat Kermani  N, et al.  The role of WNT5a and TGF-β1 in airway remodelling and severe asthma. Allergy. 2025;80(4):1025–1037. 10.1111/all.16445. [DOI] [PubMed] [Google Scholar]
  • 12. Amaral  A, Sadowska  A, Cerveira-Pinto  M, et al.  Ovarian steroids modulate mRNA expression of ECM associated genes and collagen deposition induced by TGF β1 in equine endometrium in vitro. Sci Rep. 2025;15(1):538. 10.1038/s41598-024-84250-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13. Ma  HX, Wu  K, Dong  FH, Cai  BK, Wu  D, Lu  HY. Effects of Empagliflozin and Dapagliflozin in alleviating cardiac fibrosis through SIRT6-mediated oxidative stress reduction. Sci Rep. 2024;14(1):30764. 10.1038/s41598-024-80829-w. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14. Miao  C, Liu  L, Cao  Y, et al.  OSCC-derived EVs educate fibroblasts and remodel collagen landscape. Matrix Biol. 2024;134:132–143. 10.1016/j.matbio.2024.10.004. [DOI] [PubMed] [Google Scholar]
  • 15. Xi  Y, Ge  Y, Hu  D, et al.  Caveolin-1 scaffolding domain peptide prevents corpus cavernosum fibrosis and erectile dysfunction in bilateral cavernous nerve injury-induced rats. J Sex Med. 2023;20(11):1274-1284. 10.1093/jsxmed/qdad108. [DOI] [PubMed] [Google Scholar]
  • 16. Mahdy  RNE, Nader  MA, Helal  MG, Abu-Risha  SE, Abdelmageed  ME. Protective effect of Dulaglutide, a GLP1 agonist, on acetic acid-induced ulcerative colitis in rats: involvement of GLP-1, TFF-3, and TGF-β/PI3K/NF-κB signaling pathway. Naunyn Schmiedeberg's Arch Pharmacol. 2024;398(5):5611–5628. 10.1007/s00210-024-03631-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17. Valiño-Rivas  L, Pintor-Chocano  A, Carriazo  SM, Sanz  AB, Ortiz  A, Sanchez-Niño  MD. Loss of NLRP6 increases the severity of kidney fibrosis. J Cell Physiol. 2024;239(9):e31347. 10.1002/jcp.31347. [DOI] [PubMed] [Google Scholar]
  • 18. Cohen  ML, Brumwell  AN, Ho  TC, et al.  A fibroblast-dependent TGF-β1/sFRP2 noncanonical Wnt signaling axis promotes epithelial metaplasia in idiopathic pulmonary fibrosis. J Clin Invest. 2024;134(18):e174598. 10.1172/jci174598. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19. Shin  SH, Kim  WJ, Choi  MJ, et al.  Aberrant expression of Wnt family contributes to the pathogenesis of diabetes-induced erectile dysfunction. Andrology. 2013;2(1):107-16. 10.1111/j.2047-2927.2013.00162.x. [DOI] [PubMed] [Google Scholar]
  • 20. Xin  S, Song  W, Mao  J, et al.  Therapeutic potential of hesperidin in diabetes mellitus-induced erectile dysfunction through Nrf2-mediated ferroptosis and oxidative stress. Andrology. 2024;13(7):1702-1714. 10.1111/andr.13814. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21. Jaminon  A, Reesink  K, Kroon  A, Schurgers  L. The role of vascular smooth muscle cells in arterial Remodeling: focus on calcification-related processes. Int J Mol Sci. 2019;20(22):5694. 10.3390/ijms20225694. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22. Liu  H, Lai  W, Nie  H, et al.  PM(2.5) triggers autophagic degradation of Caveolin-1 via endoplasmic reticulum stress (ERS) to enhance the TGF-β1/Smad3 axis promoting pulmonary fibrosis. Environ Int. 2023;181(0):108290. 10.1016/j.envint.2023.108290. [DOI] [PubMed] [Google Scholar]
  • 23. Guo  M, Wang  HX, Chen  WJ. BET-inhibition by JQ1 alleviates streptozotocin-induced diabetic cardiomyopathy. Toxicol Appl Pharmacol. 2018;352(0):9-18. 10.1016/j.taap.2018.05.018. [DOI] [PubMed] [Google Scholar]
  • 24. Ávila-Martínez  DV, Mixtega-Ruiz  WK, Hurtado-Capetillo  JM, Lopez-Franco  O, Flores-Muñoz  M. Counter-regulatory RAS peptides: new therapy targets for inflammation and fibrotic diseases?  Front Pharmacol. 2024;15:1377113. 10.3389/fphar.2024.1377113. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25. Sykora  M, Kratky  V, Kopkan  L, Tribulova  N, Szeiffova  BB. Anti-fibrotic potential of angiotensin (1-7) in hemodynamically overloaded rat heart. Int J Mol Sci. 2023;24(4):3490. 10.3390/ijms24043490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26. Simões  E, Silva  AC, Teixeira  MM. ACE inhibition, ACE2 and angiotensin-(1-7) axis in kidney and cardiac inflammation and fibrosis. Pharmacol Res. 2016;107(0):154-162. 10.1016/j.phrs.2016.03.018. [DOI] [PubMed] [Google Scholar]
  • 27. Zhang  F, Ren  X, Zhao  M, Zhou  B, Han  Y. Angiotensin-(1-7) abrogates angiotensin II-induced proliferation, migration and inflammation in VSMCs through inactivation of ROS-mediated PI3K/Akt and MAPK/ERK signaling pathways. Sci Rep. 2016;6(0):34621. 10.1038/srep34621. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28. Sheng  M, Li  Q, Huang  W, et al.  Ang-(1-7)/mas axis ameliorates bleomycin-induced pulmonary fibrosis in mice via restoration of Nox4-Nrf2 redox homeostasis. Eur J Pharmacol. 2023;962(0):176233. 10.1016/j.ejphar.2023.176233. [DOI] [PubMed] [Google Scholar]
  • 29. Xu  Y, Zhang  F, Li  C, Hao  H, Hao  Y. Angiotensin-(1-7) improves diabetes mellitus-induced erectile dysfunction in rats by regulating nitric oxide synthase levels. Peptides. 2022;151:170765. 10.1016/j.peptides.2022.170765. [DOI] [PubMed] [Google Scholar]
  • 30. Qin  L, Yang  Y, Yang  Y, et al.  Ezetimibe suppresses cholesterol accumulation in lipid-loaded vascular smooth muscle cells in vitro via MAPK signaling. Acta Pharmacol Sin. 2014;35(9):1129–1136. 10.1038/aps.2014.10. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31. Zhang  K, Li  R, Matniyaz  Y, et al.  Liraglutide attenuates angiotensin II-induced aortic dissection and aortic aneurysm via inhibiting M1 macrophage polarization in APOE (-/-) mice. Biochem Pharmacol. 2024;223:116170. 10.1016/j.bcp.2024.116170. [DOI] [PubMed] [Google Scholar]
  • 32. McMahon  CG. Erectile dysfunction. Med J Aust. 2000;173(9):492–497. 10.5694/j.1326-5377.2000.tb139304.x. [DOI] [PubMed] [Google Scholar]
  • 33. Castela  A, Gomes  P, Domingues  VF, et al.  Role of oxidative stress-induced systemic and cavernosal molecular alterations in the progression of diabetic erectile dysfunction. J Diabetes. 2015;7(3):393–401. 10.1111/1753-0407.12181. [DOI] [PubMed] [Google Scholar]
  • 34. Ghafouri-Fard  S, Askari  A, Shoorei  H, et al.  Antioxidant therapy against TGF-β/SMAD pathway involved in organ fibrosis. J Cell Mol Med. 2024;28(2):e18052. 10.1111/jcmm.18052. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35. Tzavlaki  K, Moustakas  A. TGF-β Signaling. Biomolecules. 2020;10:3. 10.3390/biom10030487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36. Ong  CH, Tham  CL, Harith  HH, Firdaus  N, Israf  DA. TGF-β-induced fibrosis: a review on the underlying mechanism and potential therapeutic strategies. Eur J Pharmacol. 2021;911:174510. 10.1016/j.ejphar.2021.174510. [DOI] [PubMed] [Google Scholar]
  • 37. Shi  C, Sun  B, Wu  H, et al.  Dysfunction of Caveolae-mediated endocytic TβRI degradation results in hypersensitivity of TGF-β/Smad Signaling in Osteogenesis Imperfecta. J Bone Miner Res. 2023;38(1):103–118. 10.1002/jbmr.4734. [DOI] [PubMed] [Google Scholar]
  • 38. Mitchell  H, Choudhury  A, Pagano  RE, Leof  EB. Ligand-dependent and -independent transforming growth factor-beta receptor recycling regulated by clathrin-mediated endocytosis and Rab11. Mol Biol Cell. 2004;15(9):4166–4178. 10.1091/mbc.e04-03-0245. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 39. Siegert  AM, Serra-Peinado  C, Gutiérrez-Martínez  E, Rodríguez-Pascual  F, Fabregat  I, Egea  G. Altered TGF-β endocytic trafficking contributes to the increased signaling in Marfan syndrome. Biochim Biophys Acta Mol basis Dis. 2018;1864(2):554–562. 10.1016/j.bbadis.2017.11.015. [DOI] [PubMed] [Google Scholar]
  • 40. Razani  B, Zhang  XL, Bitzer  M, von Gersdorff  G, Böttinger  EP, Lisanti  MP. Caveolin-1 regulates transforming growth factor (TGF)-beta/SMAD signaling through an interaction with the TGF-beta type I receptor. J Biol Chem. 2001;276(9):6727–6738. 10.1074/jbc.M008340200. [DOI] [PubMed] [Google Scholar]
  • 41. Hatanaka  K, Ito  K, Shindo  T, et al.  Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction. Am J Physiol Cell Physiol. 2016;311(3):C378–C385. 10.1152/ajpcell.00152.2016. [DOI] [PubMed] [Google Scholar]
  • 42. Kulshrestha  R, Singh  H, Pandey  A, Mehta  A, Bhardwaj  S, Jaggi  AS. Caveolin-1 as a critical component in the pathogenesis of lung fibrosis of different etiology: evidences and mechanisms. Exp Mol Pathol. 2019;111(0):104315. 10.1016/j.yexmp.2019.104315. [DOI] [PubMed] [Google Scholar]
  • 43. Fraga-Silva  RA, Costa-Fraga  FP, Savergnini  SQ, et al.  An oral formulation of angiotensin-(1-7) reverses corpus cavernosum damages induced by hypercholesterolemia. J Sex Med. 2013;10(10):2430–2442. 10.1111/jsm.12262. [DOI] [PubMed] [Google Scholar]
  • 44. da Costa Gonçalves  AC, Fraga-Silva  RA, Leite  R, Santos  RA. AVE 0991, a non-peptide mas-receptor agonist, facilitates penile erection. Exp Physiol. 2013;98(3):850–855. 10.1113/expphysiol.2012.068551. [DOI] [PubMed] [Google Scholar]
  • 45. Xu  Y, Li  C, Liu  G, et al.  Ang 1-7 increases nitric oxide synthesis by modulating endothelial nitric oxide synthase-caveolin-1 interaction in rat vascular smooth muscle cells. J Biol Regul Homeost Agents. 2022;36(1):105–113. 10.23812/21-364-A. [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The datasets analyzed in the present study are available from the corresponding author upon reasonable request.

Articles from Sexual Medicine are provided here courtesy of Oxford University Press

RESOURCES