Solar-simulated irradiation evokes a persistent and biphasic IL-1alpha response.
Exposure of skin to solar-simulated irradiation generates a multitude of adaptive responses including cytokine transcription, synthesis and secretion. Interleukin-1 (IL-1) is one of the cytokines induced in epidermal cells in response to UV irradiation. It displays a broad range of mitogenic and inflammatory activities including fibroblast proliferation and T-cell activation. There are two forms, IL-1alpha and IL-1beta; and IL-1alpha is the predominant form secreted by epidermal keratinocytes. UV-induced modulations of IL-1alpha message levels have been extensively studied within the first 48 h after irradiation, but longer term changes and impact on IL-1alpha cellular protein levels are virtually unexplored. We now report that cells of keratinocyte origin (SCC 12F) respond to a single physiologic dose of solar-simulated irradiation with both early (8 h) and late (72 h) peaks of IL-1alpha mRNA induction. UV-stimulated IL-1alpha secretion is increased above sham-irradiated control secretion for at least 96 h after irradiation. Our study provides evidence that UV-induced adaptive cutaneous responses persist for at least several days, and suggests that different mechanisms may mediate the early vs. late inductions.
Luo
Dan
D
Nanjing Medical University, Department of Dermatology, Nanjing 210029, China.
Yaar
Mina
M
Tsai
Angel
A
Gilchrest
Barbara A
BA
D002294:Carcinoma, Squamous Cell; D045744:Cell Line, Tumor; D004307:Dose-Response Relationship, Radiation; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D007700:Kinetics; D012333:RNA, Messenger / Q000235:genetics; D013472:Sunlight; D014158:Transcription, Genetic / Q000528:radiation effects; D014466:Ultraviolet Rays
D007375:Interleukin-1; D012333:RNA, Messenger