IGF2BP3 Overexpression Accelerates Osteoarthritis Progression by Promoting Glycolysis via m6A-Dependent Stabilization of ECM1 mRNA.

N6-methyladenosine (m6A) plays a critical role in osteoarthritis (OA) pathogenesis. This study investigates the role of the m6A reader insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) in OA progression. OA models were established in vivo through destabilization of the medial meniscus (DMM) surgery in mice and in vitro by stimulating primary chondrocytes with interleukin-1β (IL-1β). Cartilage destruction was assessed histopathologically. Chondrocyte viability, proliferation, and apoptosis were measured by CCK-8, EdU, and flow cytometry, respectively. Inflammatory cytokine levels, lactate, glucose, and total m6A were quantified using commercial kits. Expression levels of IGF2BP3, extracellular matrix protein 1 (ECM1), ECM turnover markers, and glycolysis-related genes were analyzed by RT-qPCR, Western blot, immunohistochemistry, and immunofluorescence. Potential m6A modification sites in ECM1 transcripts were predicted using the SRAMP database, and IGF2BP3-mediated, m6A-dependent regulation of ECM1 was validated through RNA immunoprecipitation (RIP), MeRIP-qPCR, and actinomycin D decay assays. Results revealed elevated levels of IGF2BP3, ECM1, m6A modification, and glycolytic activity in OA cartilage and IL-1β-treated chondrocytes. IGF2BP3 knockdown reversed IL-1β-induced reductions in chondrocyte viability and proliferation, suppressed apoptosis, decreased inflammatory cytokine secretion, attenuated ECM degradation, and reduced glycolytic flux in vitro, while also mitigating cartilage damage and matrix breakdown in vivo. Mechanistically, IGF2BP3 stabilized ECM1 mRNA in an m6A-dependent manner, thereby modulating ECM1 expression. Restoration of ECM1 expression abolished the chondroprotective effects of IGF2BP3 knockdown against injury, inflammation, and enhanced glycolysis. In conclusion, IGF2BP3 enhances ECM1 expression via an m6A-dependent pathway, thereby promoting glycolysis and exacerbating OA progression.