Regulatory effect and mechanism of CircSEC24A in IL-1β-induced osteoarthritis.

Osteoarthritis (OA) is a chronic joint disease characterized by articular cartilage degeneration and damage. Increasing circular RNAs (circRNAs) have been identified to participate in the pathogenesis of OA. Hsa_circ_0128006 (also known as circSEC24) was reported as an upregulated circRNA in OA tissues, but its biological role and underlying mechanism in OA are still to be discussed. circSEC24A and NAMPT expression levels were upregulated, and miR-515-5p was reduced in OA cartilage tissues and IL-1β-treated CHON-001 cells. The absence of circSEC24A overturned IL-1β-induced suppression of cell viability and promotion of oxidative stress, apoptosis, extracellular matrix (ECM) degradation, and inflammation in CHON-001 cells. Mechanistically, circSEC24A acted as a molecular sponge for miR-515-5p to affect NAMPT expression. CircSEC24A knockdown could attenuate IL-1β-triggered CHON-001 cell injury partly via the miR-515-5p/NAMPT axis, providing new insight into the underlying application of circSEC24A in OA treatment.