miRNA-125b Regulates Osteogenic Differentiation of Periodontal Ligament Cells Through NKIRAS2/NF-κB Pathway

Background/Aims: Osteogenesis of periodontal ligament cells (PDLCS) is essential for alveolar bone repair. Varieties of factors have been found involved in the regulation of PDLCs osteoblast differentiation. Aim of this study was to identify microRNA as a regulator of the os-teogenic differentiation of PDLCs. Methods: The CD markers were analyzed by flow cytometry analysis. Osteoblast differentiation of PDLCs was induced by treatment with dexamethasone, β-glycerol phosphate and α-ascorbic acid. The expression of osteoblastic phenotype was evaluated after the induction by simultaneous monitoring of alkaline phosphatase activity, the expression of genes involved in osteoblastic differentiation by RT-qPCR and Western Blot, and mineralization at the same time. MicroRNA and NKIRAS2 expression was determined by RT-qPCR. Luciferase reporter assays were performed to test whether miR-125b is capable of interacting with the 3’UTR sequence of NKIRAS2. The possible signaling pathway was determined by Western Blot. Results: In this study, we found that the expression of miR-125b was down regulated during the process of ostoblast differentiation of PDLCs. When the expression of miR-125b was up regulated, the osteogenic differentiation of PDLCs was inhibited. During this process, the over-expressed miR-125b led to the activation of NF-κB. NF-κB inhibitor interacting RAS-like 2 (NKIRAS2) is one of target gene of miR-125b, and it is a regulator of NF-κB signaling that plays various roles in osteoblastic differentiation. We demonstrate thatmiR-125b is involved in osteogenic differentiation of PDLCs. Conclusion: Our data support the hypothesis that that miR-125b attenuates PDLCs osteoblastic differentiation by targeting NKIRAS2 and enhancing NF-κB signaling