ABSTRACT
Circular RNAs (circRNAs) are involved in osteoarthritis (OA) progression. This study aimed to investigate the role and molecular mechanisms of circMYO1C in OA. CircMYO1C was upregulated in OA- and interleukin-1ß (IL-1ß)-exposed chondrocytes. The results indicated that circMYO1C knockdown repressed the inflammatory factors (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], interleukin-8 [IL-8], etc.) and apoptosis of chondrocytes following IL-1ß exposure. CircMYO1C was an N6-methyladenosine (m6A)-modified circRNA with m6A characteristics. High mobility group box 1 (HMGB1) was a target of circMYO1C. IL-1ß exposure increased the stability and half-life (t1/2) of HMGB1 mRNA, while silencing circMYO1C reduced HMGB1 mRNA stability. Taken together, circMYO1C targets the m6A/HMGB1 axis to promote chondrocyte apoptosis and inflammation. The present study demonstrates that the circMYO1C/m6A/HMGB1 axis is essential for OA progression, highlighting a novel potential therapeutic target for clinical OA.