miR-217 Suppresses Osteogenic Differentiation of Human Dental Pulp Stem Cells by Down-Regulating Sirtuin 1

The paper is committed to uncovering the effect of miR-217 on osteogenic differentiation of human dental pulp stem cells (hDPSCs) and its mechanism. hDPSCs were separated from human dental pulp tissues for measurement of stemness. The osteogenic differentiation of hDPSCs was induced in an osteogenic induction medium. The hDPSCs were transfected with miR-217 mimic, miR-217 inhibitor and/or sh-SIRT1 accordingly. The expressions of miR-217 and SIRT1 were detected in hDPSCs after cell transfection and osteogenic differentiation. Calcium nodules were showed by alizarin red staining. Moreover, the expressions of osteogenic differentiation-related genes were also assessed. The binding of miR-217 to SIRT1 was predicted on starBase and further determined by dual-luciferase reporter assay. Down-regulated miR-217 and up-regulated SIRT1 were found during osteogenic differentiation of hDPSCs. The osteogenic differentiation of hDPSCs was suppressed after transfection of miR-217 mimic or sh-SIRT1 while promoted by miR-217 inhibition. Taken together, miR-217 can suppress osteogenic differentiation of hDPSCs by negatively regulating SIRT1.