Effects of Dexamethasone on Endothelin-1(ET-1) Production by Keratinocytes

ABSTRACT

Epidermal keratinocytes are important sources of a wide variety of cytokines that include the endothelin-1 (ET-1). Glucocorticoids have been shown to inhibit the production of several cytokines. However, their effect on ET-1 synthesis by keratinocytes is still unknown. It has been reported that ultraviolet B (UVB) irradiation stimulates both the synthesis and release of ET-1 and it was observed that ET-1 secretion by HaCat cells increased with increasing UVB exposure. In this study, the effects of glucocorticoid on ET-1 production were evaluated using cultured HaCat keratinocytes. The results showed that dexamethasone suppressed basal re-lease of ET-1. In addition, it strongly inhibited the UVB-mediated augmentation of ET-1 production. Furthermore, lincomycin slightly enhanced the inhibitory effect of dexamethasone on ET-1 synthesis.