MiR-320a upregulation improves IL-1β-induced osteoarthritis via targeting the DAZAP1 and MAPK pathways

Osteoarthritis (OA), a constant illness described by articular cartilage degeneration, usually manifested by joint pain and helpless development. Numerous literatures suggest that microRNAs play an important regulatory role in OA, yet the role of miR-320a in OA remains largely obscure.

To evaluate the expression of miR-320a mRNA, quantitative real-time polymerase chain reaction was used. Cell counting kit-8 assay, Edu staining, Annexin V-FITC/PI apoptosis detection assay, Caspases 3 staining, and trypan staining were conducted to monitor cell proliferation and apoptosis. Western blot was applied to examine DAZAP1 and ERK/JNK/MAPK associated protein expression. Luciferase reporter gene experiments were performed to confirm the relationships between miR-320a and DAZAP1. ELISA assay was adopted to analyze the secretion of inflammation cytokines IL-6, IL-8, and TNF-α.

In an in vitro osteoarthritis model caused by IL-1β, miR-320a expression was markedly reduced. Overexpression of miR-320a restored IL-1β-inhibited chondrocyte proliferation, induced apoptosis and inflammatory response. Mechanistically, miR-320a affected HC-A cell proliferation, apoptosis and inflammatory response by regulating DAZAPI. Meanwhile, the ERK/JNK/MAPK pathway is also involved in the regulatory role of miR-320a on OA.

Our results show an important role for miR-320a and provide new therapeutic targets for avoiding and treating osteoarthritis.