11β-Hydroxysteroid Dehydrogenase Type 1 Inhibition Attenuates the Adverse Effects of Glucocorticoids on Dermal Papilla Cells.

PURPOSE: Glucocorticoids, stress-related hormones, inhibit hair growth. Intracellular glucocorticoid availability is regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). 11β-HSD1 was recently detected in keratinocytes and fibroblasts. However, the expression of 11β-HSD1 in human hair follicles remains unknown. We aimed to examine 11β-HSD1 expression in human dermal papilla cells (DPCs) and to investigate whether modulation of 11β-HSD1 activity can regulate the negative effects of glucocorticoids on DPCs.

MATERIALS AND METHODS: 11β-HSD1 expression in normal human scalp skin was examined by immunohistochemistry. 11β-HSD1 protein was detected in Western blots of human DPCs. Cultured human DPCs were treated with cortisol with or without a selective 11β-HSD1 inhibitor and subsequently stained for Ki-67 antibody. Expression levels of 11β-HSD1, Wnt5a, alkaline phosphatase (ALP), and vascular endothelial growth factor (VEGF) were analyzed by Western blotting.

RESULTS: 11β-HSD1 was detected in dermal papilla in human scalp skin by immunohistochemistry. Human DPCs expressed 11β-HSD1 protein in vitro. Furthermore, cortisol stimulated the expression of 11β-HSD1 in DPCs. Glucocorticoids decreased cellular proliferation and the expression of Wnt5a, ALP, and VEGF in DPCs. A specific 11β-HSD1 inhibitor significantly attenuated the anti-proliferative effects of cortisol and reversed the cortisol-induced suppression of Wnt5a, ALP, and VEGF expression in DPCs.

CONCLUSION: Our data demonstrated the expression of 11β-HSD1 in human DPCs and revealed that inhibition of 11β-HSD1 activity can partially prevent the negative effect of glucocorticoids on DPCs, suggesting the possible application of 11β-HSD1 inhibitors for stress-related hair loss.