MicroRNA-126 Regulates Inflammatory Cytokine Secretion in Human Gingival Fibroblasts Under High Glucose Via Targeting Tumor Necrosis Factor Receptor Associated Factor 6

Background: MicroRNAs (miRs) play a crucial role in inflammatory diseases including periodontitis. Meanwhile, miRs act as biomarkers for predicting diabetes mellitus. However, the regulatory mechanism of miR-126 on the development of periodontitis in diabetes patients still remains unclear.Methods: Human gingival fibroblasts were cultured with low (5.5 mmol/L), medium (15 mmol/L) and high (25 mmol/L) glucose, respectively. The expressions of miR-126, tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6) and related cytokines were analyzed by real-time polymerase chain reaction (PCR). After transfected with miR-126 mimic, PCR and Western blot were performed to detect the level of TRAF6, and luciferase reporter assay confirmed if TRAF6 is the direct target of miR-126. The production of cytokines was measured using enzyme-linked immunosorbent assay (ELISA).Results: Increased glucose significantly suppressed miR-126 expression in human gingival fibroblasts (p < 0.05). Also, high glucose increased T...