MicroRNA-4423-3p inhibits proliferation of fibroblast-like synoviocytes by targeting matrix metalloproteinase 13 in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is increasing in incidence worldwide. RA is regulated by a variety of microRNAs (miRNAs/miR). Moreover, analysis of public data has revealed that miR-4423-3p is significantly downregulated in peripheral blood mononuclear cells of RA patients. This study investigated the role of miR-4423-3p in RA. The levels of miR-4423-3p and matrix metalloproteinase 13 (MMP13) in RA patients and the regulatory relationship between miR-4423-3p and MMP13 were analyzed using public data. A dual-luciferase reporter assay was performed to verify that miR-4423-3p targets MMP13 in human fibroblast-like synoviocyte (HFLS) RA cells (HFLS-RA). Following the overexpression of miR-4423-3p, miR-4423-3p inhibitor, and MMP13 in HFLS-RA, viability, proliferation, cell cycle, apoptosis, and invasion/migration assays were used to detect the effects of miR-4423-3p targeting MMP13 on cell biological processes. The results revealed that miR-4423-3p was downregulated in peripheral blood mononuclear cells of RA patients and MMP13 was upregulated in synovial tissue of RA patients. miR-4423-3p targets the 3' untranslated region of MMP13 and downregulates MMP13 expression. After overexpression of miR-4423-3p, cell proliferation, migration, and invasion were inhibited, the cell cycle was prevented and cell apoptosis was promoted. Overexpression of MMP13 promoted cell proliferation, migration, and invasion, while accelerating the cell cycle process and suppressing apoptosis. The findings indicate that in HFLS-RA cells, overexpression of miR-4423-3p inhibited proliferation, migration, and invasion, and promoted apoptosis by negatively regulating MMP13. The overexpression of miR-4423-3p might be a novel strategy for the treatment of RA.