Sun J, Yan P, Chen Y, Chen Y, Yang J, Xu G, Mao H, Qiu Y. MicroRNA-26b inhibits cell proliferation and cytokine secretion in human RASF cells via the Wnt/GSK-3β/β-catenin pathway.
Diagn Pathol 2015;
10:72. [PMID:
26088648 PMCID:
PMC4472173 DOI:
10.1186/s13000-015-0309-x]
[Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 06/02/2015] [Indexed: 01/01/2023] Open
Abstract
Background
Rheumatoid arthritis (RA) is a chronic systemic auto- immune disease characterized by joint synovitis. Recent evidence suggests that rheumatoid arthritis synovial fibroblasts (RASFs) promote joint destruction. In this study, we investigated the role of microRNA-26b (miR-26b) in cell proliferation and inflammatory cytokine secretion using patient-derived Rheumatoid arthritis fibroblast-like synoviocyte (RAFLS) to understand pathways influencing rheumatoid arthritis.
Methods
RAFLS were cultured in vitro and transfected with miR-26b mimics (experimental group) and negative sequence (control group). The protein levels of Wnt4, Wnt5ɑ, GSK-3β, CyclinD1, Ser9-GSK-3β and β-catenin were detected by western blot analysis. Tumor Necrosis Factor-ɑ (TNF-ɑ), IL- 1β, and IL-6 levels were quantified by Enzyme-linked Immunosorbent Assay (ELISA). RAFLS proliferation and apoptosis were measured by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry, respectively.
Results
GSK-3β and CyclinD1 expression levels were lower in miR-26b mimic group compared to Mock group and negative control (NC) group. Conversely, GSK-3β and CyclinD1 expression levels were markedly higher in the miR-26b inhibitor group compared to Mock and NC group (P < 0.05). Transfection of miR-26b mimics significantly increased the, levels of Ser9-GSK-3β and β-catenin in comparison to Mock and NC groups, while transfection of miR-26b inhibitors showed the opposite effect. In miR-26b mimic group, TNF-α, IL- 1β and IL-6 levels were lower than the Mock and NC groups, while in miR-26b inhibitor group, these cytokine levels were higher than the Mock and NC groups (P < 0.05). Transfection of miR-26b mimics significantly reduced the cell proliferation of RAFLS, compared to the Mock and NC groups, and miR-26b inhibitors increased the proliferative capacity of RAFLS compared to Mock and NC groups (P < 0.05). The miR-26b mimic group exhibited higher RAFLS apoptosis rate compared to Mock and NC group and miR-26b inhibitor group showed significantly lower RAFLS apoptosis rate compared to Mock and NC groups (P < 0.05).
Conclusions
MiR-26b regulates β-catenin and CyclinD1 levels by inhibiting GSK-3β expression, which in-turn alters the Wnt/GSK-3β/β-catenin pathway to lower RAFLS proliferation and elevate cell apoptosis and the secretion of TNF-α,IL-1β and IL-6 cytokines. Therefore, our results show that miR-26B plays a central role in inhibiting the inflammation associated with rheumatoid arthritis.
Virtual Slides
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9063056861547150
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