Potential of miR-25-3p in protection of chondrocytes: emphasis on osteoarthritis.

Introduction: Osteoarthritis (OA) is the most prevailing musculoskeletal dysfunction triggered by lesions in synovial membranes and articular cartilage. MicroRNAs (miRNAs) have emerged as crucial regulators participated in many biological processes, such as osteoarthritis. This study was undertaken to address the role of miR-25-3p in the apoptosis of rat chondrocytes under an OA-like condition and its underlying mechanism.

Material and methods: OA cellular model was established in rat chondrocytes by TNF-a induction. Then, qRTPCR and Western blotting were utilized for evaluation of the expressions of miR-25-3p and insulin-like growth factor-binding protein 7 (IGFBP7), CCK-8 assay for inspection of chondrocyte viability, flow cytometry for assessment of cell apoptosis rate, Western blotting for the detection of cleaved caspase-3 level and dual-luciferase reporter gene assay for verification of the targeting relationship between miR-25-3p and IGFBP7.

Results: The miR-25-3p expression was decreased and IGFBP7 was elevated in TNF-a-induced rat chondrocytes. The miR-25-3p inhibited chondrocyte apoptosis and IGFBP7 promoted apoptosis as evidenced by enhanced cell viability and suppressed cell apoptosis in OA chondrocytes after miR-25-3p overexpression or IGFBP7 knockdown. The miR-25-3p facilitated chondrocyte viability and repressed cell apoptosis in OA by negatively regulating IGFBP7.

Conclusions: MiR-25-3p negatively regulates IGFBP7 to promote chondrocyte proliferation and restrain chondrocyte apoptosis. Our findings suggest that the regulation of IGFBP7 by miR-25-3p may emerge as a novel therapeutic regimen for OA.