The role of estrogen-metabolizing enzymes and estrogen receptors in human epidermis

Local estrogen metabolism and its sensitivities in the skin have been also suggested to contribute to skin homeostasis in addition to age- and/or gender-dependent circulating estrogen, even though their local mechanisms have been largely unknown. To characterize their potential correlations, age- and gender-dependencies were evaluated focusing on 5 pivotal estrogen-metabolizing enzymes including aromatase, estrogen sulfotransferase, steroid sulfatase, and 17 beta-hydroxysteroid dehydrogenases and estrogen receptors (ER alpha and ER beta) using immunohistochemistry of 100 human skin specimens. When their epidermal expression levels were compared among 7 age groups, ranging from the teens to the seventies, the highest expression in the teens group and the lowest expression in the seventies group were found in the expression of aromatase and ER beta, respectively, while no significant differences between the male and the female groups were found in the immunoreactivities of our interested proteins. Our results suggest that age-related differences in aromatase and ER beta expressions impact epidermal homeostasis. (C) 2011 Elsevier Ireland Ltd. All rights reserved.