Effects of pulsed electrical stimulation on -smooth muscle actin and type I collagen expression in human dermal fibroblasts

Pulsed electrical stimulation (PES) is known to affect cellular activities. We previously found PES to human dermal fibroblasts (HFs) promoted platelet-derived growth factor subunit A (PDGFA) gene expression, which enhanced proliferation. In this study, we investigated PES effects on fibroblast collagen production and differentiation into myofibroblasts. HFs were electrically stimulated at 4800 Hz and 5 V for 60 min. Imatinib, a specific inhibitor of PDGF receptors, was treated before PES. After 6 h of PES, PDGFA, alpha-smooth muscle actin (alpha-SMA), and collagen type I alpha 1 chain gene expressions were upregulated in PES group. Imatinib suppressed the promoted expression except for PDGFA. Immunofluorescence staining and enzyme-linked immunosorbent assay showed the production of alpha-SMA and collagen I was enhanced in PES group but suppressed in PES + imatinib group at 48 h after PES. Therefore, PES promotes the production of alpha-SMA and collagen I in fibroblasts, which is triggered by PDGFA that is upregulated early after PES.