Evaluation of MicroRNA-146a and Its Targets in Gingival Tissues of Patients With Chronic Periodontitis.

BACKGROUND: MicroRNAs (miRNAs) are a group of small non-coding RNAs that play an important role in the regulation of gene expression. miRNA-146a (miR-146a), a member of the miR-146 family, is involved in the control of inflammation. Periodontitis is a set of chronic inflammatory disorders of the tissues surrounding the teeth that lead to the breakdown of alveolar bone and tooth loss. In this study, expression levels of miR-146a and its targets, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6, are evaluated in human patients with chronic periodontitis (CP). METHODS: The study population consisted of 10 healthy controls and 20 individuals with CP. For each participant, clinical parameters including probing depth and clinical attachment level were measured, and a gingival tissue sample was collected. Levels of miR-146a, TNF-alpha, IL-1beta, and IL-6 were quantified using real-time polymerase chain reaction. RESULTS: Levels of miR-146a were significantly higher in patients with CP (P <0.001). There was a positive correlation between levels of miR-146a and clinical parameters (P <0.05). Elevated miR-146a was accompanied by a significant reduction in TNF-alpha and IL-6 (P <0.001). CONCLUSIONS: Patients with CP had higher levels of miR-146a than healthy individuals, accompanied by reduced levels of TNF-alpha and IL-6. A positive relationship between miR-146a levels and clinical parameters suggests a pathophysiologic role of miR-146a in CP.