In contrast to melanocytes, keratinocytes of normal human adult interfollicular epidermis do not express galectin-1

Introduction Galectins constitute a phylogenetically conserved family of proteins that specifically bind to glycoconjugates bearing β-galactoside residues. Although galectin-1 (Gal 1), the first identified member of the galectin family, is involved in highly important biological processes at the molecular and cellular level in human skin, its expression in keratinocytes of normal human adult interfollicular epidermis (NHAIE) remains in dispute, whereas that in epidermal melanocytes has drawn very little attention so far. This prompted us to investigate the expression of Gal 1 in the keratinocytes and melanocytes of NHAIE. Methods Biopsy specimens obtained from the buttock skin of 23 healthy adult volunteers of both sexes were processed for single and double immunohistochemical staining using antibodies against Gal 1 and Melan-A. Results In contrast to epidermal melanocytes, which revealed a distinct Gal 1 immunoreactivity, keratinocytes of NHAIE were completely devoid of any expression of this galectin. Conclusions This article simultaneously assesses Gal 1 immunoreactivity of keratinocytes and melanocytes in NHAIE for the first time. Our findings may contribute to a better understanding of alterations in Gal 1 expression in various benign and malignant cutaneous disorders and may be of importance for the future design of targeted therapies.