MicroRNA-495 attenuates proliferation and inflammatory response in rheumatoid arthritis fibroblast-like synoviocytes...

Fibroblast-like synoviocytes (FLSs) exert a critical effect in the occurrence and progress of rheumatoid arthritis (RA). MicroRNA-495 (miR-495) can regulate many growth behaviors in various cell types. Nevertheless, the role of miR-495 is still unclear in RA-FLS. We aimed to explore the role and molecular mechanism of miR-495 in RA. The FLSs and synovial tissue from normal and RA cases were used in the study. RT-PCR analysis was used to examine the expression of miR-495. Western blot assay was conducted to determine the levels of matrix metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2) and β-catenin. Cell counting kit-8 (CCK-8) assays were performed to determine the proliferation of RA-FLS in different treatment groups. The results showed that miR-495 is down-regulated in both RA-synovial tissue and RA-FLSs. Overexpression of miR-495 could inhibit RA-FLS proliferation and inflammatory factors of interleukin (IL)-6, IL-11 and tumor necrosis factor alpha (TNF-α), and decrease the protein expression of MMP-9 and MMP-2. In addition, miR-495 could negatively regulate the expression of β-catenin in RA-FLSs. We also confirmed that the inhibitory role of miR-495 in RA-FLS is through the regulation of β-catenin expression. Taken together, miR-495 is downregulated in RA-FLS and RA synovial tissue, and miR-495 inhibits proliferation and inflammatory response in RA-FLS, partially via regulating β-catenin expression. The miR-495/β-catenin pathway may serve as a new therapeutic target for RA.