MicroRNA-199a regulates myocardial fibrosis in rats by targeting SFRP5.

Abstract

Myocardial fibrosis seriously affects normal heart function. This study focused on the role of microRNA-199a in regulating rat myocardial fibrosis by targeting secreted frizzled-related protein 5 (SFRP5). The in vitro myocardial fibrosis model was established by 10 μM isoproterenol (ISO) induction in cardiac fibroblasts (CFs) for 24 h. Expression levels of microRNA-199a, collagen I and α smooth muscle actin (α-SMA) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels of SFRP5 and transforming growth factor-β1 (TGF-β1) in CFs were detected by Western blot. The binding condition between microRNA-199a and SFRP5 was verified by luciferase reporter gene assay. After transfection of microRNA-199a inhibitor or SFRP5 overexpression plasmid, proliferative and migratory rates of CFs were determined by cell counting kit-8 (CCK-8) and transwell assay, respectively. ISO treatment remarkably upregulated microRNA-199a expression in CFs. Transfection of microRNA-199a inhibitor could inhibit proliferation, migration and cardiac fibroblast-to-myofibroblast transformation (CMT) of CFs. Luciferase reporter gene assay confirmed the binding of microRNA-199a to SFRP5 3'UTR. Moreover, SFRP5 overexpression reversed the effects of microRNA-199a inhibitor on proliferation, migration, and CMT of CFs. MicroRNA-199a deficiency can inhibit the proliferative and migratory potentials of CFs, as well as CMT by targeting SFRP5, thus exerting the protective effect on myocardial fibrosis.