Expression of Runx-۲ and Ocn Genes in Rat Bone Marrow Stem Cells Post-Induced by Osteogenesis Differen-tiation Medium and Electromagnetic Field

Objective: Bone marrow stem cells (BMSCs) are one of the most important sources for repairing bone lesions in tissue en-gineering. The effect of sinusoidal electromagnetic field on the expression of osteogenic genes has been reported.Materials and Methods: In this study, BMSCs of rats after confirmation by flow cytometry, were evaluated in three experi-mental groups: negative control (cultured cells in α-MEM, ۱۰% fetal bovine), positive control (cultured cells in osteogenesis differentiation medium), and OD+۵۰ (exposed cells to electro-magnetic field with a frequency of ۵۰ Hz, intensity of ۱ mT daily for half an hour and osteogenesis differentiation medium). After ۱۴ days, the extracellular matrix was stained with Alizarin Red and expression of Runx-۲ and Ocn genes was assessed by quantitative Real-Time PCR, ۱۴ and ۲۱ days post induction. Differentiation into adipogenic and osteogenic cells was ob-served with Oil Red-O and Alizarin Red staining.Results: The regions that responded positively to the staining were higher in the OD+۵۰ group than in the positive control. On days ۱۴ and ۲۱, the expression of Runx-۲ and Ocn genes in OD+۵۰ showed a significant increase compared to positive control. While the intergroup comparison showed that the ex-pression of these genes in the OD+۵۰ group on day ۲۱ was not significantly different from those of day ۱۴.Conclusion: As a result, the sinusoidal electromagnetic field had a stimulatory effect on the mRNA levels of Runx۲ and Ocn genes expression in BMSCs treated with the electromagnetic field and the osteogenesis differentiation medium simultane-ously. The electromagnetic field accelerates fracture healing by stimulating osteogenesis.