Overexpressed miR-486 in bone marrow mesenchymal stem cells represses urethral fibrosis and targets Col13a1 in urethral stricture rats

Urethral stricture (US) is a challenging problem in urology and its pathogenesis of US is closely related to the fibrotic process. Previous evidence has indicated the downregulation of microRNA (miR)-486 in injured urethral specimens of rats. This study aimed to explore the effects of miR-486-overexpressed bone marrow mesenchymal stem cells (BMSCs) on US. BMSCs were identified by detecting their multipotency and surface antigens. Lentivirus virus expressing miR-486 was transduced into rat BMSCs to overexpress miR-486. Transforming growth factor (TGF)-β1 induced fibrotic phenotypes in urethral fibroblasts (UFs) and rat models. Western blotting showed protein levels of collagen I/III and collagen type XIII alpha 1 chain (Col13a1). Real time quantitative polymerase chain reaction was utilized for messenger RNA level evaluation. Hematoxylin-eosin, Masson's trichrome, and Von Willebrand Factor staining were conducted for histopathological analysis. Immunofluorescence staining was employed for detecting alpha smooth muscle actin (α-SMA) expression. Luciferase reporter assay verified the interaction between miR-486 and Col13a1. The results showed that miR-486-overexpressed BMSCs suppressed collagen I/III and α-SMA expression in TGF-β1-stimulated UFs. miR-486-overexpressed BMSCs alleviated urethral fibrosis, collagen deposition, and epithelial injury in the urethral tissue of US rats. miR-486 targeted and negatively regulated Col13a1 in US rats. In conclusion, overexpression of miR-486 in BMSCs targets Col13a1 and attenuates urethral fibrosis in TGF-β1-triggered UFs and US rats.