Oestrogen receptor beta is the predominant oestrogen receptor in human scalp skin

Abstract: Oestrogens play a major role in non‐classic target tissues in both sexes, yet there have been few studies on estrogens and skin. Recently a second oestrogen receptor (ERβ) has been discovered. Therefore, we have compared the expression of oestrogen receptor alpha (ERα), beta (ERβ), the androgen receptor (AR) and a cell proliferation marker in male and female non‐balding scalp skin. ERβ was the major steroid receptor expressed in human skin. It was highly expressed in epidermis, blood vessels and dermal fibroblasts, in contrast to ERα and AR. In the hair follicle, ERβ expression was localized to nuclei of outer root sheath, epithelial matrix and dermal papilla cells, in contrast to ERα, and the AR, which was only expressed in dermal papilla cells. Serial sections also showed strong nuclear expression of ERβ in the cells of the bulge, while neither ERα nor AR was expressed. In the sebaceous gland, ERβ was expressed in both basal and partially differentiated sebocytes. ERα exhibited a similar pattern of expression, while the AR was expressed in the basal and very early differentiated sebocytes. There was no obvious difference in the expression of either oestrogen receptor in male or female skin. The wide distribution of ERβ in human skin suggests that oestrogens may play an important role in the maintenance of skin and in the regulation of the pilosebaceous unit, and provides further evidence for oestrogen action in non‐classic target tissues. The differential expression of ERα, ERβ and AR in human skin suggests that the mechanisms by which steroid hormones mediate their effects may be more complex than previously thought.