Effects of glucocorticoid on human dermal papilla cells in vitro.

Glucocorticoid (GC) is synthesized mostly in the adrenal gland and is secreted in response to stressful conditions. The stress-induced increase in systemic GC may mediate diverse types of cellular damage. However, the specific effects of GC on the dermal papilla cells (DPCs) of hair follicles remain unknown, although stress-related hair loss has increased significantly in recent years. The objective of this study was to determine the effect of a synthetic GC, dexamethasone (Dex), on human DPCs in vitro. We evaluated the effects of Dex on cell proliferation, survival, and the expression of growth factors in DPCs. Dex treatment (1μM) significantly reduced the number of viable cells and the expression of the Ki-67 protein, VEGF and HGF were downregulated following treatment of DPCs with Dex. Taken together, we concluded that Dex inhibits human hair growth by inhibiting both the proliferation of, and growth factors expression by, DPCs.