In Vitro Study of the Osterix and Osteopontin Genes Expression in Conditioned Medium- and Pulsed Electromagnetic Field-induced Bone Marrow Mesenchymal Stem Cells

Conditioned medium and electromagnetic field stimulate osteogenic gene expression and proliferation in rBMSCs for osteoblast differentiation in vitro.

This study aimed to determine the expression of Osterix and Osteopontin genes in bone marrow mesenchymal stem cells induced by medium and pulsed electromagnetic fields.

The experimental groups included rBMSCs cultured in α-MEM containing 10% FBS (negative control), in osteogenesis differentiation medium (positive control), and exposed to EMF (50 Hz, 1 mT), 30 min daily. The treatment groups were also exposed to CM (CM group), simultaneously exposed to osteogenesis differentiation medium and EMF (OD+50 Hz group), and also exposed to CM and EMF (CM+50 Hz group). Osterix (OSX) and Osteopontin (OPN) gene expression were evaluated by Real-time PCR, after 14 days.

The OSX gene expression was significantly increased in the OD and CM+50HZ groups, as compared to the negative control (p˂0.05). These results demonstrated that CM+50HZ and OD promoted the expression of the OSX gene. This gene was also significantly decreased in the CM, 50HZ, and OD+5OHZ groups, compared to the OD group (p˂0.05). It was suggested that these treatments had an inhibitory effect on the expression of the OSX gene. The positive control group had a significantly higher level of OPN gene expression, than that of negative control. The CM, OD+50HZ, CM+50HZ, and 50HZ groups showed no significant difference of that gene expression, compared to the negative control.

In vitro osteogenic differentiation of rBMSCs occurs 14 days after induction, preparing osteoblasts for tissue engineering by combining CM and EMF for 30 minutes.