Down-regulation of lncRNA MEG3 promotes endothelial differentiation of bone marrow derived mesenchymal stem cells in repairing erectile dysfunction

Abstract Aims In the treatment of diabetes mellitus associated erectile dysfunction (DMED), the intracavernous and periprostatic implantations of bone marrow derived mesenchymal stem cells (BM-MSCs) represent the new therapeutic approaches with great applied prospect. However, the specific mechanisms of BM-MSCs protecting erectile function remain largely unknown. Materials and methods The DMED rats were induced and the erectile function was assessed in the models with or without BM-MSCs implantation using intracavernous pressure (ICP)/mean arterial pressure (MAP) ratio. The differentiation of BM-MSCs toward endothelial cells (ECs) was induced by exogenous vascular endothelial growth factor (VEGF) in vitro. RNA pull-down and RIP assays were performed to explore the interaction between MEG3 and FOXM1 protein. Key findings Intracavernous implantation of BM-MSCs effectively improved the erectile function of DMED rats, which was accompanied by a significant decrease in the expression of MEG3 in the corpus cavernosum tissues. Also, our study revealed that MEG3 expression was significantly down-regulated during the endothelial differentiation of BM-MSCs in vitro. The down-regulation of MEG3 was further confirmed to be conducive to the differentiation of BM-MSCs toward ECs. More importantly, MEG3 promoted the degradation of FOXM1 protein via facilitating FOXM1 ubiquitination, thereby decreasing VEGF expression, which ultimately regulated the endothelial differentiation of BM-MSCs. Significance Taken together, our findings presented the vital role of MEG3 in the repairing processes of BM-MSCs for erectile function and provided new mechanistic insights into the BM-MSCs-mediated DMED repairing.