miR-124a as a key regulator of proliferation and MCP-1 secretion in synoviocytes from patients with rheumatoid arthritis.

MicroRNAs (miRNA) are a class of small endogenous non-coding RNAs that influence the stability and translation of messenger RNA. Synoviocytes from patients with rheumatoid arthritis (RA) were analysed for their miRNA expression profile, and it was found that miR-124a levels significantly decreased in RA synoviocytes as compared with osteoarthritis synoviocytes. Transfection of miR-124a into RA synoviocytes significantly suppressed their proliferation and arrested the cell cycle at the G1 phase. miR-124a directly binds to the 3'-untranslated region of cyclin-dependent kinase 2 (CDK-2) and monocyte chemoattractant protein 1 (MCP-1) mRNA, and the induction of miR-124a in RA synoviocytes significantly suppressed the production of the CDK-2 and MCP-1 proteins. It is proposed that miR-124a is a key miRNA in the post-transcriptional regulatory mechanisms of RA synoviocytes, and has a therapeutic potential.