Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degradation and joint inflammation in which microRNAs are significantly involved. Previous studies have reported that miR-142-3p is a novel mediator of inflammatory signaling pathways, but whether miR-142-3p regulates OA remains unknown. In this study, we aimed to investigate the potential role of miR-142-3p in OA and the underlying molecular mechanism. We showed that miR-142-3p was significantly reduced in the articular cartilage tissues from experimental OA mice. The expression of miR-142-3p was also decreased in chondrocytes treated with lipopolysaccharide (LPS) in vitro. Moreover, the overexpression of miR-142-3p significantly inhibited cell apoptosis, nuclear factor (NF)-kB, and the production of proinflammatory cytokines, including interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α induced by LPS. Interestingly, bioinformatics analysis demonstrated that high mobility group box 1 (HMGB1), an important inflammatory mediator of OA, was predicted as a target of miR-142-3p, which was validated by dual-luciferase reporter assay. The high expression of HMGB1 in chondrocytes induced by LPS was significantly inhibited by miR-142-3p overexpression. Furthermore, the restoration of HMGB1 markedly abrogated the effect of miR-142-3p. In OA mice, the overexpression of miR-142-3p by lentivirus-mediated gene transfer significantly inhibited HMGB1 expression, NF-kB signaling, and proinflammatory cytokines. Moreover, the overexpression of miR-142-3p significantly alleviated OA progression in OA mice in vivo. Taken together, our study suggests that miR-142-3p inhibits chondrocyte apoptosis and inflammation in OA by inhibiting the HMGB1-mediated NF-kB signaling pathway. The overexpression of miR-142-3p impedes the OA progression in mice in vivo indicating that miR-142-3p is a potential molecular target for OA treatment.
Keywords: chondrocyte apoptosis; high mobility group box 1; inflammation; miR-142-3p; osteoarthritis.