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Epidermal melanocytes are skin cells specialized in melanin production. Activation of the melanocortin 1 receptor (MC1R) on melanocytes by α-melanocyte-stimulating hormone (α-MSH) induces synthesis of the brown/black pigment eumelanin that confers photoprotection from solar UV radiation (UVR). Contrary to keratinocytes, melanocytes are slow proliferating(More)
The melanocortin 1 receptor gene is a main determinant of human pigmentation, and a melanoma susceptibility gene, because its variants that are strongly associated with red hair color increase melanoma risk. To test experimentally the association between melanocortin 1 receptor genotype and melanoma susceptibility, we compared the responses of primary human(More)
We have successfully established normal neonatal and adult human melanocyte cultures in a growth medium containing the physiologic mitogens basic fibroblast growth factor (bFGF; 0.6 ng/ml), endothelin-1 (endo-1; 10 nM), and alpha-melanocyte stimulating hormone (alpha-MSH; 10 nM). The latter two factors replaced the commonly used mitogens(More)
Activation of the melanocortin 1 receptor (MC1R) by α-melanocortin (α-MSH) stimulates eumelanin synthesis and enhances repair of ultraviolet radiation (UV)-induced DNA damage. We report on the DNA damage response (DDR) of human melanocytes to UV and its enhancement by α-MSH. α-MSH up-regulated the levels of XPC, the enzyme that recognizes DNA damage sites,(More)
Endothelin-1 is a paracrine factor with mitogenic, melanogenic and survival effects on cultured human melanocytes. We report that endothelin-1 signalling reduced the generation and enhanced the repair of ultraviolet radiation (UV)-induced DNA photoproducts, and inhibited apoptosis of human melanocytes, without increasing cAMP levels, melanin content or(More)
Cultured skin substitutes have become useful as adjunctive treatments for excised, full-thickness burns, but no skin substitutes have the anatomy and physiology of native skin. Hypothetically, deficiencies of structure and function may result, in part, from nutritional deficiencies in culture media. To address this hypothesis, vitamin C was titrated at 0.0,(More)
The significance of melanotropic hormones as physiologic regulators of cutaneous pigmentation in humans is still controversial. Until recently, no direct effect for melanotropins could be demonstrated on human melanocytes. Here we present conclusive evidence that alpha-melanotropin (alpha-melanocyte-stimulating hormone, alpha-MSH) and the related hormone(More)
Cultured skin substitutes have been used successfully for adjunctive treatment of excised burns and chronic skin wounds. However, limitations inherent to all models of cultured skin include deficient barrier function in vitro, and delayed keratinization after grafting in comparison to native skin autografts. Experimental conditions for incubation of skin(More)
Unpredictable pigmentation in cultured skin substitutes (CSS) is an anatomic deficiency after wound treatment and can require years to normalize. Variable numbers of human melanocytes (HM) survive in cultures of human keratinocytes (HK) as demonstrated by focal areas of pigmentation in CSS after healing. The purposes of this study were to deplete HM from HK(More)
Human melanocytes from individuals with different skin types, as well as from the skin of the same individual, are heterogeneous in their melanin content. This heterogeneity may be attributed to differences in the activity and expression of the three melanogenic proteins: tyrosinase and tyrosinase-related proteins 1 and 2 (gp75 and DOPAchrome tautomerase,(More)