Effect of miR-21 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells

To explore the effect of miR-21 on human periodontal ligament stem cells (PDLSCs) proliferation and osteogenesis and to provide a theoretical basis for the stem cell treatment of periodontitis.

hPDLSCs were isolated and cultured with the enzymatic tissue block method, and surface molecules (CD34, CD45, CD90 and CD105) were detected by flow cytometry. An miR-21 mimics (pre-miR-21) and inhibitor (anti-miR-21) were transfected into hPDLSCs by Lipofectamine 2000. The experiment groups: mimics-NC group, mimics group, inhibitor group, and inhibitor-NC group. The transfection efficiency of miR-21 was determined by qRT-PCR. Proliferation was detected by CCK-8 and flow cytometry. The osteogenic differentiation ability of hPDLSCs was determined by alizarin red staining. Western blot was used to detect the protein expression of osteogenic related genes: Runx2.

The mRNA expression of miR-21in the mimics group was significantly higher than that in the mimics-NC group; additionally, the expression in the inhibitor group was significantly weaker than that in the inhibitor-NC group (P < 0.05). hPDLSCs proliferation and the S phase cell ratio in the mimics group were stronger than those in the mimics-NC group(P < 0.05); those in the inhibitor group were weaker than those in the inhibitor-NC group (P < 0.05). After alizarin red staining, the mimics group was found to have more mineralized modules than mimics-NC group, and the inhibitor group had fewer than that in the inhibitor-NC group. Runx2 protein expression in the mimics group was higher than that in the mimics-NC group (P <0.05), and expression was lower in the inhibitor group than in the inhibitor-NC group (P < 0.05).

miR-21can promote the proliferation and osteogenesic differentiation of hPDLSCs.