MicroRNA-19a-3p promotes rheumatoid arthritis fibroblast-like synoviocytes via targeting SOCS3.

Rheumatoid arthritis (RA) is a common chronic autoimmune disease and effective treatment for RA is still lacking. In this study, the regulatory role of miR-19a-3p in RA was investigated. Quantitative polymerase chain reaction analysis of human blood samples showed that the level of miR-19a-3p was significantly lower in the RA patients compared with that in healthy patients (P < 0.05). In RA fibroblast-like synoviocytes (RAFLS), miR-19a-3p and suppressor of cytokine signaling 3 (SOCS3) were also downregulated and upregulated, respectively, compared with those of normal FLS. Transfection of miR-19a-3p mimic in RAFLS inhibited cell proliferation and promoted cell apoptosis. TargetScan identified SOCS3 as a target of miR-19a-3p, which was confirmed by dual-luciferase assay. Western blot indicated that SOCS3 protein level was significantly decreased after miR-19a-3p overexpression. Moreover, SOCS3 silencing through siRNA transfection also enhanced cell proliferation, meanwhile inhibiting RAFLS apoptosis. In addition, SOCS3 overexpression abrogated the effects of miR-19a-3p overexpression on cell proliferation and apoptosis, corroborating that SOCS3 acts as a downstream effector in the miR-19a-3p-mediated function of RAFLS. These findings suggest that miR-19a-3p plays an important role in RA, and the miR-19a-3p/SOCS3 axis may become a potential therapeutic target for RA.