Long noncoding RNA NAV2-AS5 relieves chondrocyte inflammation by targeting miR-8082/TNIP2 in osteoarthritis

Osteoarthritis (OA) is a common chronic and frequently occurring orthopedic disease in the middle-aged and elderly individuals. Numerous studies have shown that long noncoding RNAs (lncRNAs) play major roles in various diseases. However, the potential molecular mechanism of action of NAV2-AS5 in OA remains unclear. The present study was designed to explore the influence of NAV2-AS5 on the progression of chondrocyte inflammation and its underlying molecular mechanisms. To simulate the inflammatory environment in OA, the human chondrocyte cell line was treated with LPS. Cell proliferation, cell cycle progression, and apoptosis were assessed using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine analysis, and flow cytometry. Proliferation- and cycle-related proteins and the release of inflammatory factors were examined by western blot analysis and enzyme-linked immunosorbent assay. The downstream targets of NAV2-AS5 were determined using bioinformatics and confirmed by a luciferase reporter assay. In our study, patients with OA showed downregulation of NAV2-AS5, upregulation of miR-8082, and downregulation of TNFAIP3 interacting protein 2 (TNIP2). Moreover, we found that both overexpression of NAV2-AS5 and miR-8082 inhibitor promoted cell proliferation, inhibited apoptosis, and released inflammatory cytokines in LPS-treated chondrocytes. MiR-8082 was predicted to be a target of both NAV2-AS5 and TNIP2. In addition, rescue experiments showed that silencing of TNIP2 reversed the effects of the miR-8082 inhibitor on proliferation, cell cycle, apoptosis, and inflammatory factors in sh-NAV2-AS5-treated chondrocytes. In conclusion, these findings indicate that NAV2-AS5 relieves chondrocyte inflammation by targeting miR-8082/TNIP2 in OA, which provides a new theoretical basis for OA therapy.