Skin Pigmentation and its Regulation: Role of Keratinocyte and Ovarian Hormones on Human Melanocytes in Vitro / 대한해부학회지

ABSTRACT

Estrogen and progesterone are thought to be responsible for the pigmentary changes in pregnancy and also melasma. To investigate the action mechanism of estrogen and progesterone on the facultative skin pigmentation, Human melanocytes and keratinocytes were cultivated in the forms of pure melanocyte culture, co-culture (melanocytes and keratinocytes were cultivated together in a vessel but they were separated with membrane) or mixed culture (melanocytes and keratinocytes were cultivated together in a vessel in mixed form). After 2 days of cultivation in the presence of hormones (estrogen, progesterone and melanocyte stimulating hormone), the author studied the cell proliferation, the cellular features (the number of dendrites, perimeter and area), and the tyrosinase activity of melanocytes. Progesterone or melanocyte stimulating hormone increased in both the cell growth and the tyrosinase activity in pure melanocyte culture but estrogen did not. However, mixed culture treated with estrogen lead to increases in the tyrosinase activity. Pure melanocyte culture treated with estrogen or progesterone increased in the cell perimeter and the area but not in the number of dendrites. Co-cultured melanocytes without hormones revealed more increases in the perimeter (p.0.01) and the area (p.0.01) even in the number of dendrites (p.0.01) compared to the pure cultured melanocytes treated with the hormones. It was postulated with these results that estrogen, progesterone and keratinocyte possibly induced hyperpigmentation of the skin via the keratinocytes stimulated by estrogen, via the proliferation of melanocytes induced by progesterone, and via the cellular features altered by keratinocytes.