MicroRNA-98 regulates osteogenic differentiation of human bone mesenchymal stromal cells by targeting BMP2.

To study the effects of microRNA-98 (miR-98) on human bone mesenchymal stromal cells (hBMSCs). The patients undergoing hip arthroplasty were selected by inclusion/exclusion criteria for this study. The extracted hBMSCs were detected of osteogenic differentiation by alizarin red S staining, and of cell phenotype by flow cytometry. Bioinformatics, dual luciferase report, western blotting, RT-PCR and immunoblotting were used in our study. The hBMSCs were divided into miR-98 mimics, miR-98 negative control (NC), miR-98 inhibitors, Mock and miR-98 inhibitors + siBMP2 groups. Human bone mesenchymal stromal cells were extracted and purified in vitro and had specific cytological morphology, surface markers and abilities of self-renewal and differentiation. Compared with the NC group and Mock group, the miR-98 mimics group showed increased miR-98 level while the miR-98 inhibitors group decreased miR-98 level (both P < 0.01). Dual luciferase reporter showed BMP2 was the target gene of miR-98. The levels of mRNA and protein expression of BMP2, protein expression of RUNX2, alkaline phosphatase activity and osteocalcin content significantly decreased in the miR-98 mimics group while increased in the miR-98 inhibitors group and showed no changes in the NC group and Mock group (all P < 0.05). The miR-98 mimics group showed obviously declined stained red particles and the miR-98 inhibitors group showed opposite result. After lowering the expression of miR-98, osteogenic differentiation ability of hBMSCs rose, which was weakened by the transfection with siBMP2. miR-98 may regulate osteogenic differentiation of hBMSCs by targeting BMP2.