Diagnostic value of serum miR-4284 in knee osteoarthritis and its chondroprotective mechanism via targeting TNFAIP8

Early diagnosis of knee osteoarthritis (KOA) lacks sensitive molecular biomarkers. While miR-4284 is implicated in various inflammatory diseases, its specific role and mechanism in KOA remain poorly understood. To evaluate the clinical diagnostic value of serum miR-4284 in KOA and elucidate its underlying chondroprotective mechanisms. Serum samples were collected from 95 KOA patients and 90 healthy controls. An in vitro KOA model was established by treating C28/I2 chondrocytes with IL-1β. Cell proliferation, apoptosis, pro-inflammatory cytokines (IL-6, TNF-α, IL-8), oxidative stress markers, and cartilage metabolic markers were systematically evaluated. The targeted regulatory relationship between miR-4284 and TNFAIP8 was verified via dual-luciferase reporter assays and rescue experiments. Serum miR-4284 was significantly downregulated in KOA patients, yielding a high diagnostic accuracy (AUC = 0.874). In vitro, miR-4284 overexpression promoted chondrocyte proliferation, reduced apoptosis, and attenuated IL-1β-induced inflammatory responses, oxidative stress, and cartilage matrix degradation. Mechanistically, miR-4284 directly targeted and negatively regulated TNFAIP8 . Notably, TNFAIP8 overexpression successfully reversed the cartilage-protective effects mediated by miR-4284. Serum miR-4284 serves as a promising diagnostic biomarker for KOA. Furthermore, miR-4284 has the potential to alleviate chondrocyte injury and maintain cartilage homeostasis by directly targeting TNFAIP8 , highlighting a potential therapeutic axis for KOA intervention.