Interleukin-1alpha stimulates the differentiation of melanocytes but inhibits the proliferation of melanoblasts from neonatal mouse epidermis.
Interleukin (IL)-1alpha is one of the important cytokines involved in regulating immunological reactions in the mouse skin. However, it is not known whether IL-1alpha regulates the proliferation and differentiation of mouse epidermal melanocytes. In this study, to investigate the role of IL-1alpha in the regulation of the proliferation and differentiation of mouse epidermal melanocytes, IL-1alpha was supplemented to serum-free primary cultures of epidermal cell suspensions from the initiation of the primary culture (keratinocytes and melanoblasts-melanocytes) as well as to pure cultures of melanoblasts-melanocytes (keratinocyte-depleted cultures, after 14 days), and its effect was tested. IL-1alpha inhibited the proliferation of undifferentiated melanoblasts irrespective of the presence or absence of keratinocytes, whereas the cytokine inhibited the proliferation of differentiated melanocytes only in the presence of keratinocytes. Moreover, IL-1alpha induced the differentiation of melanocytes and, in addition, stimulated tyrosinase activity, melanin synthesis, and dendritogenesis of melanocytes irrespective of the presence or absence of keratinocytes. These results suggest that IL-1alpha is involved in inhibiting the proliferation of neonatal murine epidermal melanoblasts and in stimulating the differentiation, melanogenesis, and dendritogenesis of melanocytes. The results also suggest that IL-1alpha inhibits the proliferation of differentiated melanocytes in cooperation with keratinocyte-derived factors.
Hirobe
Tomohisa
T
Radiation Effect Mechanism Research Group, National Institute of Radiological Sciences, Chiba, Japan. thirobe@nirs.go.jp
Ootaka
Haruki
H
D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003470:Culture Media; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects; D053582:Interleukin-1alpha / Q000494:pharmacology* / Q000502:physiology; D015603:Keratinocytes / Q000502:physiology; D008543:Melanins / Q000032:analysis; D008544:Melanocytes / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D014442:Monophenol Monooxygenase / Q000032:analysis / Q000187:drug effects; D013997:Time Factors
D003470:Culture Media; D053582:Interleukin-1alpha; D008543:Melanins; D014442:Monophenol Monooxygenase