In vitroDifferentiation of Hair Follicle Stem Cell into Keratinocyte by Simvastatin

Background:Hair follicle stem cells (HFSCs) located in the bulge area has shown to be highly proliferative and could differentiate into neurons, glia, smooth muscle cell, and melanocytes in vitro. Simvastatin is an HMG-CoA reductase inhibitor that exerts pleiotropic effects beyond simple low-density lipoprotein lowering and has a similar impact on the differentiation of bone marrow stromal cells and peripheral blood mononuclear cells. The present study examinedthe hypothesis that the application of simvastatin would induce the HFSCs differentiation into keratinocyte. Methods:The bulge of the hair follicle was anatomized,and HFSCs were cultivated. The flow cytometry and immunocytochemical stainingfor detection of nestin, CD34, and Kr15 biomarkers were performedbefore differentiation.In order to hasten the HFSCs differentiation to keratinocyte, HFSCs were treated with 1μM, 2μM, and 5μM of simvastatin dailyfor a week. After differentiation, the flow cytometry and immunocytochemical stainingwere performedwith Kr15 and Kr10 biomarkers,and the MTT assay was carried outas an index of cell viability and cell growth.Results:Our results showed that bulge of HFSCs were nestin and CD34 positive and Kr15 negative. Simvastatin significantly increased the viability of HFSCs (p<0.05)at the concentration of 5μM. In addition, the percentages of keratinocyte-differentiated cells treated with 5μM of simvastatin showed a significant increase compared to all other treated groups (p<0.05). Conclusion:Our findingsdemonstrate that 5μM of simvastatin could induce HFSCs differentiation into keratinocyte.