Abstract
Recent studies have demonstrated that microRNAs (miRNAs) are involved in many pathological conditions including osteoarthritis (OA). In the present study, we aimed to investigate the role of miR-197 in OA and the potential molecular mechanism. The expression levels of miR-197 were detected by quantitative real-time PCR analysis. Cell proliferation and migration abilities were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide and transwell assays. The concentrations of inflammatory cytokines, including IL-1β, IL-6, and TNF-α, were detect using ELISA assay. Furthermore, luciferase reporter and rescue assays were applied to identify the functional target gene of miR-197 in OA. The results showed that miR-197 expression was significantly down-regulated in the OA cartilage tissues compared with normal cartilage tissues, accompanied by up-regulation of EIF4G2 expression. An inverse correlation was found between EIF4G2 and miR-197 expressions in OA cartilage tissues. Treatment with miR-197 mimics promoted the growth and migration abilities of chondrocytes, while miR-197 inhibitors induced the opposite effects. Furthermore, restoration of miR-197 significantly decreased IL-1β, IL-6, and TNF-α expression, whereas knockdown of miR-197 led to a induction in these inflammatory mediators. Moreover, EIF4G2 was predicted and confirmed as a directly target of miR-197. Overexpressed miR-197 could down-regulate EIF4G2 expression in chondrocytes, while miR-197 knockdown could elevate EIF4G2 expression. Additionally, EIF4G2 overexpression reversed the effects of miR-197 mimics on chondrocytes proliferation, migration, and inflammation. Taken together, our study demonstrated that miR-197 promotes chondrocyte proliferation, increases migration, and inhibits inflammation in the pathogenesis of OA by targeting EIF4G2, indicating the potential therapeutic targets of the miR-197/EIF4G2 axis for OA treatment.