Up-regulation of miR-365 promotes the apoptosis and restrains proliferation of synoviocytes through downregulation of IGF1 and the inactivation of the PI3K/AKT/mTOR pathway in mice with rheumatoid arthritis.

There is growing evidence of the ability of microRNAs (miRs) in rheumatoid arthritis (RA), thus our objective was to discuss the impact of miR-365 on the apoptosis and proliferation of synoviocytes in mice with RA by targeting IGF1 and mediating the PI3K/AKT/mTOR pathway. RA model mice was induced by type II collagen and freund's adjuvant. The successfully modeled mice were injected with normal saline, miR-365 mimics, miR-365 inhibitors or their controls. TUNEL assay was adopted to detect apoptosis in synovial tissues, and expression of IL-1β and IL-6 in serum and synovial tissues was measured by ELISA and RT-qPCR. Mouse synoviocytes were isolated and cultured in vitro and identified by experiments. Cells were transfected with miR-365 mimics, IGF1 siRNA, or their controls to verify the role of miR-365 and IGF1 in cell vitality, proliferation and apoptosis of synoviocytes. Upregulation of miR-365 increased the number of TUNEL positive cells, depressed arthritis index, X-ray imaging score, and the expression of IL-1β and IL-6. High expression of miR-365 and low expression of IGF1 restrained the proliferation and facilitated apoptosis of synoviocytes. MiR-365 inhibited the expression of IGF1 and inhibited the activation of the PI3K/AKT/mTOR pathway. Our study presents that up-regulation of miR-365 drives on apoptosis and restrains proliferation of synoviocytes in RA through downregulation of IGF1 and the inhibition of the PI3K/AKT/mTOR pathway. Thus, miR-365 may be a potential candidate for treatment of RA.