Effect of low frequency electromagnetic field on osteogenic differentiation of human adipocyte-derived mesenchymal stem cells

Background and Aim: Human adipose-derived stem cells (hASCs) due to the potential for multiple differentiation, easy extraction, relative abundance, high proliferation capacity in vitro, frozen storage and secretion of cytokines are a good candidate for regenerative medicine compared to other stem cells. Pulsed electromagnetic field (PEMF) is one of the biophysical stimuli that affect adult stem cells of the body by increasing the intracellular calcium associated with membrane depolarization and osteogenic differentiation. The effects of PEMF on stem cell differentiation depend on certain parameters such as waveform, duration of exposure, frequency, field intensity, and cell type, so some studies have reported that PEMF stimulates osteogenesis and increased bone mineral density, but other studies have reported conflicting. In this study, the effect of PEMF on the expression of bone-specific gene such as Runx۲ was investigated.Methods: hASCs were extracted from abdominal adipose tissue of cesarean women after obtaining written informed consent and cultured in vitro until the third passage. Stem cells were confirmed by flow cytometry. The experimental groups were: negative control (cultured in alpha-MEM and ۱۰% serum), positive control (cultured in bone differentiation medium) and treated cells incubated with PEMF at a frequency of ۵۰ Hz and intensity of ۱ mT, ۸ hours daily for ۳ weeks.Results: The mineralization of treated cells matrix was confirmed by Alizarin Red staining. The expression of Runx۲ gene was also evaluated by Real time PCR. It was shown decrease of Runx۲ gene expression in treated cells compared to negative control. There was also significant difference between treated and positive control groups.Conclusion: Despite clinical success, pulsed electromagnetic field has negative effects on bone cell differentiation.

Keywords:

Human adipose stem cells , Electromagnetic field , Osteogenic differentiation , Runx۲