Teriflunomide Slows Osteoarthritis Progression via Wnt/β-Catenin and NLRP3 Pyroptosis Pathways

Osteoarthritis (OA) is a progressive, degenerative joint disorder characterized by irreversible loss of articular cartilage, in which NLRP3 inflammasome-mediated chondrocyte pyroptosis and dysregulated Wnt/β-catenin signaling are recognized as central pathological events. This study investigated the potential chondroprotective effects of teriflunomide (TFM) in OA, revealing a repositioning molecular mechanism whereby TFM inhibits NLRP3-dependent pyroptosis through the reactivation of Wnt/β-catenin signaling. In vitro, using immortalized human chondrocyte (HC) cells, TFM markedly inhibited interleukin (IL)-1β-induced NLRP3 inflammasome activation and the subsequent pyroptosis relative to that of vehicle-treated control cells. Concurrently, TFM restored Wnt/β-catenin signaling, as indicated by the recovered expression of β-catenin, c-Myc, and cyclin D1. Furthermore, TFM suppressed IL-1β-induced reactive oxygen species generation and speck formation by apoptosis-associated speck-like protein containing a CARD, thus promoting the functional recovery of chondrocytes. These in vitro results were further corroborated in a rat model of OA (n = 6 per group). TFM administration (30 mg/kg, every other day for 4 weeks) improved joint morphology, alleviated synovitis, and restored cartilage thickness and proteoglycan content relative to those observed in vehicle-treated animals. Collectively, these findings suggest that TFM exerts chondroprotective effects in preclinical models by reactivating Wnt/β-catenin signaling and inhibiting NLRP3-dependent pyroptosis. TFM warrants further investigation as a potential candidate agent for the treatment of patients with OA.