Solar-simulated irradiation evokes a persistent and biphasic IL-1alpha response

Exp Dermatol. 2004 Jan;13(1):11-7. doi: 10.1111/j.0906-6705.2004.00102.x.


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.

MeSH terms

  • Carcinoma, Squamous Cell
  • Cell Line, Tumor
  • Dose-Response Relationship, Radiation
  • Gene Expression Regulation, Neoplastic / radiation effects
  • Humans
  • Interleukin-1 / genetics
  • Interleukin-1 / metabolism
  • Interleukin-1 / radiation effects*
  • Kinetics
  • RNA, Messenger / genetics
  • Sunlight*
  • Transcription, Genetic / radiation effects
  • Ultraviolet Rays*


  • Interleukin-1
  • RNA, Messenger