ObjectiveOsteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation, causing severe pain and disability. Recent studies suggest that miR-450a-5p may regulate inflammatory pathways in OA. This study aimed to elucidate the role of miR-450a-5p in OA, providing a potential therapeutic target for the clinical treatment.MethodsCartilage tissues were collected from OA patients undergoing knee replacement surgery, and CHON-001 cells were treated with interleukin (IL)-1β to induce an OA model . Real-time quantitative polymerase chain reaction was used to detect the miR-450a-5p expression, and Western blot determined the lipopolysaccharide-induced tumor necrosis factor (TNF)-α factor (LITAF) expression. The targeting relationship between LITAF and miR-450a-5p was verified by dual-luciferase reporter assay. Cell proliferation and apoptosis were assessed using the Cell Counting Kit-8 assay and flow cytometry, respectively. Levels of IL-6, IL-10, and TNF-α were measured via enzyme-linked immunosorbent assay. In addition, Western blot was employed to detect the expressions of matrix metalloproteinase-3 (MMP-3), collagen III, and aggrecan in extracellular matrix (ECM).ResultsMiR-450a-5p expression was significantly down-regulated in OA tissues and IL-1β-induced CHON-001 cells (60%), while LITAF expression was markedly increased (1.8-fold). There was a negative correlation between miR-450a-5p and LITAF in OA tissues (r = -0.596, < 0.01). MiR-450a-5p directly targeted and inhibited LITAF expression. Its overexpression promoted chondrocyte proliferation, reduced apoptosis and inflammatory cytokines, and mitigated ECM degradation.ConclusionsMiR-450a-5p inhibited LITAF expression, thereby attenuating apoptosis, inflammation, and ECM degradation in chondrocytes. It may serve as a promising therapeutic target for OA.