Low-intensity pulsed electromagnetic fields and the differentiation of epidermal stem cells

Abstract

Objective To observe the effect of a low-intensity pulsed electromagnetic field (LIPEMF) on the differentiation of epidermal stem cells (EpSCs),and to explain the regulation of any observed effect on the gene level.Methods EpSCs were isolated from the back skin of neonatal Sprague-Dawley rats,and divided into three experimental groups and a control group.The three experimental aliquots received 5 mT magnetic field irradiation pulsed at 15 Hz,50 Hz or 75 Hz.After 10 days of continuous stimulation,immunofluorescence was used to observe any differentiation,RT-PCRs tested for c-myc and β-catenin mRNA,and immunohistochemical methods were applied to test for cytokeratin 18 (CK18).Results The EpSCs of the three stimulation groups all differentiated,and differentiation-related CK 18 showed significant expression in the 50 Hz group.Expression of c-myc mRNA increased significantly in all three experimental samples compared with the controls.Expression of β-catenin mRNA decreased significantly in all three samples compared with the controls.Conclusion LIPEMFs can induce the differentiation of EpSCs.Irradiation at 50 Hz and 5 mT is the most effective.The effect may be related to enhanced expression of c-myc and inhibited expression of β-catenin. Key words: Epidermis stem cells; Electromagnetic fields; Differentiation