OBJECTIVETo investigate the effect of microRNA-99a-5p (miR-99a-5p) on differentiation ability of human bone marrow mesenchymal stem cells (BM-MSC).

METHODSBM-MSC was cultured and then transfected with miR-99a-5p mimics or inhibitors. The transfection efficiency was detected by real-time quantitative PCR. The effects of miR-99a-5p on the adipogenic and osteogenic differentiation ability of BM-MSC were detected by differentiation experiment.

RESULTSAs compared with the negative control group, the expression of miR-99a-5p was significantly up-regulated after transfection with miR-99a-5p mimics(P<0.001), the expression of miR-99a-5p was down-regulated after transfection with miR-99a-5p inhibitor (P<0.001). In osteogenic differentiation experiments, the miR-99a-5p overexpression could promote the osteogenic differentiation, while the downregulation of miR-99a-5p expression inhibited the osteogenic differentiation. The same results were obtained by semi-quantitative detection through spectrophotometry. In the adipogenic differentiation test, transfection of miR-99a-5p mimics or inhibitors had no significant effect on the adipogenic differentiation of BM-MSC.

CONCLUSIONOverexpression of miR-99a-5p can promote the osteogenic differentiation of BM-MSC, but no significant effects are observed in the adipogenic differentiation.