KIAA1429 promotes chondrocyte senescence and ferroptosis in osteoarthritis progression by facilitating m6A-mediated downregulation of USP3.

Abstract

Osteoarthritis (OA) is a common orthopedic disorder with complicated pathological mechanisms. This study aimed to uncover a novel regulatory network related to vir-like m6A methyltransferase-associated protein KIAA1429 (also known as VIRMA) and ubiquitin-specific protease 3 (USP3) in the progression of OA. An in vitro model of OA was constructed by treating chondrocytes (C28/I2) with interleukin-1β (IL-1β). qRT-PCR and Western blot were applied for gene and protein expression detection. Cell viability was examined using a CCK-8 assay. Cell death was evaluated by flow cytometry following Annexin V/PI staining. Cell senescence was assessed by senescence-associated β-galactosidase (SA-β-gal) staining. Ferroptosis-related events were detected by commercial kits. The interaction between KIAA1429 and USP3 was confirmed via RNA immunoprecipitation assay and dual-luciferase reporter assay. OA mice model was induced by surgical destabilization of the medial meniscus (DMM). Results showed that KIAA1429 expression was up-regulated in C28/I2 cells after IL-1β exposure. Inhibition of KIAA1429 impeded senescence and ferroptosis in IL-1β-treated C28/I2 cells. Mechanistically, KIAA1429 reduced USP3 mRNA expression through m6A methylation modification. Moreover, the protective effects of KIAA1429 knockdown on IL-1β-induced senescence and ferroptosis in C28/I2 cells were rescued by USP3 downregulation. In vivo, KIAA1429 downregulation suppressed the development of OA in DMM mice. These results elucidate that KIAA1429 promotes the senescence and ferroptosis of chondrocytes by increasing m6A methylation of USP3 to suppress its stability, thereby contributing to the pathogenesis of OA.