MiR-26a and miR-26b mediate osteoarthritis progression by targeting FUT4 via NF-κB signaling pathway.

Osteoarthritis (OA) is the most common joint disease, characterized by articular cartilage degradation and changes in all other joint tissues. MicroRNAs (miRNAs) play an important role in mediating the main risk factors for OA. This study aimed to investigate the effect of miR-26a/26b on the proliferation and apoptosis of human chondrocytes by targeting fucosyltransferase 4 (FUT4) through NF-κB signaling pathway. We revealed the differential expression profiles of FUT4 and miR-26a/26b in the articular cartilage tissues of OA patients and normal people. The ability of miR-26a/26b to specifically interact with the 3'UTR of FUT4 was demonstrated via a luciferase reporter assay in chondrocytes. Further results showed altered levels of miR-26a/26b and FUT4 could regulate the process of IL-1β-induced extracellular matrix degradation in chondrocytes. Forced miR-26a/26b expression was able to affect chondrocytes proliferation and apoptosis, while altered expression of FUT4 in chondrocytes modulated progression upon transfection with miR-26a/26b mimic or inhibitor. In OA mice, the overexpression of miR-26a/26b by intra-articular injection significantly attenuated OA progression. In addition, regulating FUT4 expression markedly modulated the activity of NF-κB signaling pathway, and this effect could be reversed by miR-26a/26b. In short, miR-26a/-26b/FUT4/NF-κB axis may serve as a predictive biomarker and a potential therapeutic target in OA treatment.