MicroRNA-320a protects against osteoarthritis cartilage degeneration by regulating the expressions of BMI-1 and RUNX2 in chondrocytes.

Osteoarthritis (OA) is one of the most common chronic degenerative diseases characterized by deterioration of articular cartilage. Many studies have demonstrated the role of microRNAs (miRNAs) in OA, but the role of miR-320a in OA remains elusive. The aim of this study was to identify the protective role of miR-320a in OA cartilage degeneration by regulating the expression of BMI-1 and RUNX-2 proteins in chondrocytes. Normal and OA chondrocytes obtained from patients were cultured in vitro. The chondrocytes (both normal and OA) were transfected with miR-320a inhibitor to investigate the effects of miR-320a on chondrocyte proliferation, and to identify the miR-320a target proteins. The results indicated that miR-320a expression was significantly higher (P<0.05) in OA chondrocytes than in normal chondrocytes. Inhibition of miR-320a effectively enhanced chondrocyte cell viability in vitro in a time-dependent manner. Inhibition of miR-320a showed a significant decrease (P<0.05) in the secretion of matrix metalloproteinase-13 (MMP-13). Furthermore, miR-320a could regulate the expression levels of BMI-1 and RUNX-2 proteins in OA chondrocytes (P<0.05). The data suggested that miR-320a protected against OA cartilage degeneration and regulated the expression levels of BMI-1 and RUNX2 proteins in chondrocytes. Our study might provide a new insight in the clinical treatment of OA.