EMF frequency dependent differentiation of rat bone marrow mesenchymal stem cells to astrocyte cells.

The numerous factors regulate the bone marrow mesenchymal stem cell (BMMSC) self-renewal and differentiation response. We aimed to analyze the influence of electromagnetic field (EMF) as an external inducing factor on rat BMMSC differentiation and proliferation to neuron and astrocyte cells. BMMSCs extracted from the rats femurs and tibias and incubated in a cell-cultured CO incubator. After the third passages, the plates selected randomly and then divided into seven groups (Sham exposed, three groups of square, and three groups of sinusoidal waveform EMF (25, 50, and 75 Hz, 400 μT, 1 h/day). The BMMSCs exposed to EMF at the middle of a Helmholtz coil for 7 days. The viable cell counting and proliferation performed by the MTT test and BMMSC differentiation into the neuron and the astrocyte cell was studied by immunocytochemistry staining. The results confirmed BMMSC viability and proliferation rate reduction in sinusoidal 25 Hz, square 50 Hz and sinusoidal 75 Hz EMF groups compare to sham. The maximum BMMSC differentiation to neuron was considered in sinusoidal 50 Hz and 75 Hz EMF groups. The increase of BMMSC differentiation to astrocyte cell was frequency dependent and the most differentiation was shown in square 75 Hz, and sinusoidal 75 Hz EMF groups. In conclusion, the results suggest that both square and sinusoidal EMF could affect BMMSC development and differentiation to neuron and astrocyte cells. Further studies for the consequence of EMF with wider flux density and frequency on BMMSC are recommended.