Upregulation of miR-27b Facilitates Apoptosis of TNF-α-Stimulated Fibroblast-Like Synoviocytes.

Purpose: The aim of this study was to explore the function of microRNA-27b (miR-27b) in fibroblast-like synoviocytes (FLSs) stimulated by tumor necrosis factor alpha (TNF-alpha). Materials and Methods: mRNA expression of miR-27b in FLS cells (MH7A) treated with or without TNF-alpha was determined by qPCR. MiR-27b mimics was transfected into MH7A cells to upregulate miR-27b expression. MTT assay and flow cytometry analysis were performed to investigate the effect of miR-27b on MH7A cell viability and apoptosis. The targets of miR-27b were predicted by TargetScan. The direct regulation of miR-27b on IL-1 beta expression was verified by luciferase assay. The protein expression levels of apoptosis-related proteins, IL-1 beta, and NF-kappa B signaling-related proteins were detected by Western blot. Results: We discovered that miR-27b expression was decreased in MH7A cells stimulated by TNF-alpha. Upregulation of miR-27b by miR-27b mimics significantly inhibited the proliferation and promoted the apoptosis of TNF-alpha-stimulated MH7A cells. Consistently, upregulation of miR-27 decreased the level of Bcl-2 and increased Bax and caspase-3 expression in MH7A cells stimulated by TNF-alpha. Luciferase assay revealed that IL-1 beta was indeed a target of miR-27b. By quantitative real-time PCR and Western blot, we found that the expression of IL-1 beta is negatively regulated by miR-27b. Moreover, the NF-kappa B signaling pathway was significantly inhibited by miR-27b. Conclusion: Taken together, our results illustrated that enhanced miR-27b expression results in the suppression of proliferation and the promotion of apoptosis in FLSs stimulated by TNF-alpha, partially by regulating IL-1 beta expression and NF-kappa B signaling.