title: Keratinocytes control the proliferation and differentiation of cultured epidermal melanocytes from ultraviolet radiation B-induced pigmented spots in the dorsal skin of hairless mice.
abstract: Long-term exposure of ultraviolet radiation B (UVB)-induced pigmented spots in the dorsal skin of hairless mice of Hos:(HR-1 X HR//De) F1. Previous study showed that the proliferative and differentiative activities of cultured epidermal melanoblasts/melanocytes from UVB-induced pigmented spots increased with the development of the pigmented spots. To determine whether the increase in the proliferative and differentiative activities of epidermal melanoblasts/melanocytes was brought about by direct changes in melanocytes, or by indirect changes in surrounding keratinocytes, pure cultured melanoblasts/melanocytes and keratinocytes were prepared and co-cultured in combination with control and irradiated mice in a serum-free culture medium. Keratinocytes from irradiated mice stimulated the proliferation and differentiation of both neonatal and adult non-irradiated melanoblasts/melanocytes more greatly than those from non-irradiated mice. In contrast, both non-irradiated and irradiated adult melanocytes proliferated and differentiated similarly when they were co-cultured with irradiated adult keratinocytes. These results suggest that the increased proliferative and differentiative activities of mouse epidermal melanocytes from UVB-induced pigmented spots are regulated by keratinocytes, rather than melanocytes.
authors.affiliation: Radiation Hazards Research Group, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba, Japan. thirobe@nirs.go.jp
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hirobe
authors.forename: Rikako
authors.initials: R
authors.lastname: Furuya
authors.forename: Satoru
authors.initials: S
authors.lastname: Akiu
authors.forename: Ohji
authors.initials: O
authors.lastname: Ifuku
authors.forename: Minoru
authors.initials: M
authors.lastname: Fukuda
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002450:Cell Communication / Q000502:physiology / Q000528:radiation effects*; D002454:Cell Differentiation / Q000502:physiology / Q000528:radiation effects; D002455:Cell Division / Q000502:physiology / Q000528:radiation effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism / Q000528:radiation effects*; D005260:Female; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D008543:Melanins / Q000096:biosynthesis / Q000528:radiation effects; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D008812:Mice, Hairless; D010859:Pigmentation Disorders / Q000378:metabolism / Q000503:physiopathology; D012880:Skin Pigmentation / Q000502:physiology / Q000528:radiation effects*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D008543:Melanins