LncRNA MALAT1 facilitates BM-MSCs differentiation into endothelial cells and ameliorates erectile dysfunction via the miR-206/CDC42/PAK1/paxillin signalling axis.

BACKGROUND: Erectile dysfunction (ED) is a common male sexual dysfunction, with an increasing incidence, and the current treatment is often ineffective. METHODS: Vascular endothelial growth factor (VEGFA) was used to treat bone marrow-derived mesenchymal stem cells (BM-MSCs), and their cell migration rates were determined by Transwell assays. The expression of the von Willebrand Factor (vWF)VE-cadherin, and endothelial nitric oxide synthase(eNOS) endothelial markers was determined by qRT‒PCR and Western blot analyses. The MALAT1-induced differentiation of BM-MCs to ECs via the CDC42/PAK1/paxillin pathway was explored by transfecting VEGFA-induced BM-MSC with si-MALAT1 and overexpressing CDC42 and PAK1. The binding capacity between CDC42, PAK1, and paxillin in VEGFA-treated and non-VEGFA-treated BM-MSCs was examined by protein immunoprecipitation. MiR-206 was overexpressed in VEGFA-induced BM-MSC, and the binding sites of MALAT1, miR-206, and CDC42 were identified using a luciferase assay. Sixty male Sprague‒Dawley rats were divided into six groups (n = 10/group). DMED modelling was demonstrated by APO experiments and was assessed by measuring blood glucose levels. Erectile function was assessed by measuring the intracavernosa pressure (ICP) and mean arterial pressure (MAP). Penile erectile tissue was analysed by qRT‒PCR, Western blot analysis, and immunohistochemical staining. RESULTS: MALAT1 under VEGFA treatment conditions regulates the differentiation of BM-MSCs into ECs by modulating the CDC42/PAK1/paxillin axis. In vitro experiments demonstrated that interference with CDC42 and MALAT1 expression inhibited the differentiation of BM-MSCs to ECs. CDC42 binds to PAK1, and PAK1 binds to paxillin. In addition, CDC42 in the VEGFA group had a greater ability to bind to PAK1, whereas PAK1 in the VEGFA group had a greater ability to bind to paxillin. Overexpression of miR-206 in VEGFA-induced BM-MSCs demonstrated that MALAT1 competes with the CDC42 3'-UTR for binding to miR-206, which in turn is involved in the differentiation of BM-MSCs to ECs. Compared to the DMED model group, the ICP/MAP ratio was significantly greater in the three BM-MSCs treatment groups. CONCLUSIONS: MALAT1 facilitates BM-MSC differentiation into ECs by regulating the miR-206/CDC42/PAK1/paxillin axis to improve ED. The present findings revealed the vital role of MALAT1 in the repair of BM-MSCs for erectile function and provided new mechanistic insights into the BM-MSC-mediated repair of DMED.

Nitro-oleic acid (NO2-OA) ameliorates erectile dysfunction in a rat model of diabetes mellitus via modulation of fibrosis, inflammation and autophagy.

Background: Inflammation, fibrosis and autophagy represent closely related factors associated with the pathogenesis of diabetes mellitus erectile dysfunction (DMED). In this study, the therapeutic effect of nitro-oleic acid (NO2-OA) in a streptozotocin-induced rat model of DMED was evaluated. Methods: Sixty rats were randomly divided into four groups: control, DMED, DMED + Vehicle and DMED + NO2-OA. DMED was induced by intraperitoneal injection of streptozotocin in male rats. Blood glucose and body weight were measured every 2 weeks. After 4 weeks of NO2-OA treatment, erectile function was measured by electrical stimulation of cavernous nerve (CN). Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), immunofluorescence and Masson's trichrome staining were used to verify the related factors and protein expression levels. Results: We found that NO2-OA could significantly increase erectile pressure in the corpus cavernosum of DMED rats. Results of western blot, confocal immunofluorescence and qRT-PCR assays revealed that NO2-OA significantly reduced inflammatory factors and the expression of nuclear factor kappa B (NF-κB). In addition, Masson staining results indicated that NO2-OA significantly reduced the display of fibrotic tissue in the corpus cavernosum. These beneficial effects may be related to reductions in the expression of transforming growth factor-ß1 (TGF-ß1) and connective tissue growth factor (CTGF) and the increase in the expression of α-smooth muscle actin (α-SMA). Finally, NO2-OA treatment increased the expression of the autophagy marker, LC3, while P62 was decreased, effects suggesting that one of the underlying mechanisms of NO2-OA may involve an activation of the PI3K/AKT/mTOR pathway to enhance the capacity for autophagy within this tissue. Conclusions: NO2-OA enhances erectile function within a rat model of DMED by inhibiting inflammation and fibrosis along with activating autophagy.