Low frequency‑pulsed electromagnetic fields promote osteogenic differentiation of bone marrow‑derived mesenchymal stem cells by regulating connexin 43 expression.

The present study investigated the effect of connexin 43 (Cx43) on the regulation of osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) using low-frequency-pulsed electromagnetic fields (LPEMF). The BMSCs were isolated and cultured using adherent whole-bone marrow cultures. CCK-8 assay was used to detect the effects of LPEMF on the proliferation ability of BMSCs and alkaline phosphatase (ALP) activity and the levels of osteogenic marker genes were detected to evaluate the osteogenic ability change following LPEMF treatment. Lentiviral vector-mediated RNA interference was transfected into BMSCs to inhibit the expression of Cx43 and western blotting was used to detect Cx43 expression. The BMSCs showed the highest proliferation following LPEMF treatment at 80 Hz for 1 h. The results of ALP activity, osteogenic marker genes and Alizarin Red S staining showed that the osteogenic ability was notably increased following LPEMF treatment at 80 Hz for 1 h. Cx43 expression increased during the osteogenic differentiation of BMSCs following LPEMF treatment at 80 Hz. The enhanced osteogenic differentiation of the LPEMF-treated BMSCs were partially reversed when Cx43 expression was inhibited. LPEMF may promote the osteogenic differentiation of BMSCs by regulating Cx43 expression and enhancing osteogenic ability.