Ultraviolet B irradiation-enhanced interleukin (IL)-6 production and mRNA expression are mediated by IL-1 alpha in cultured human keratinocytes

J Invest Dermatol. 1996 Apr;106(4):715-20. doi: 10.1111/1523-1747.ep12345608.


Ultraviolet (UV) B radiation may trigger cutaneous inflammatory responses by directly inducing epidermal keratinocytes to elaborate specific cytokines such as interleukin (IL-1) and IL-6. Because IL-1 is a potent inducer of IL-6, one may speculate that the release of IL-6 by keratinocytes after UV exposure is mediated via the release of IL-1 in an autocrine or paracrine manner. We demonstrated that UVB irradiation upregulated IL-1 alpha mRNA at a lower dose (15 mJ/cm2) and then downregulated IL-1 alpha mRNA expression at high doses (30-40 mJ/cm2). The kinetic profile of IL-1alpha mRNA expression showed a biphasic response, with the early increase by 1 h after UV exposure and the secondary increase at 6 h after UV. On the other hand, the expression of IL-6 mRNA was increased with increasing doses of UVB (0-45 m/J/cm2) and showed a single peak at 6 h post UV. These results may indicate that UVB radiation could regulate the expression of IL-1alpha and IL-6 mRNA in keratinocytes by different mechanisms. Our data show that anti-human IL-1alpha antibody inhibits UV-induced IL-6 production and mRNA expression in cultured keratinocytes. The addition of recombinant IL-1alpha to the medium increased IL-6 synthesis and augmented IL-6 production and mRNA expression in cultured human keratinocytes by UVB irradiation. These results support the hypothesis that UVB irradiation-enhanced IL-6 production and mRNA expression may be mediated by IL-1alpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Gene Expression Regulation / radiation effects
  • Humans
  • Interleukin-1 / genetics
  • Interleukin-1 / physiology*
  • Interleukin-6 / biosynthesis*
  • Interleukin-6 / genetics
  • Keratinocytes / metabolism
  • Keratinocytes / radiation effects*
  • Mice
  • RNA, Messenger / analysis*
  • Rabbits
  • Ultraviolet Rays*


  • Interleukin-1
  • Interleukin-6
  • RNA, Messenger