UVB activates ERK1/2 and p38 signaling pathways via reactive oxygen species in cultured keratinocytes

Dominik Peus, Renius A. Vasa, Astrid Beyerle, Alexander Meves, Carsten Krautmacher, Mark R. Pittelkow

Research output: Contribution to journalArticlepeer-review

200 Scopus citations


We have previously shown that hydrogen peroxide is an important mediator of ultraviolet B induced phosphorylation of the epidermal growth factor receptor in human keratinocytes. Here we demonstrate that physiologic doses of ultraviolet B and hydrogen peroxide stimulate activation of two related but distinct mitogen-activated protein kinase pathways: extracellular regulated kinase 1 and 2 (ERK1/2), as well as p38, the mammalian homolog of HOG1 in yeast which is a major kinase for a recently identified stress- induced signaling pathway. The time-dependent activation of ERK1/2 and p38 are distinct, and ultraviolet B-induced ERK1/2 activation is downregulated more rapidly than p38. Using dihydrorhodamine or Amplex as specific fluorescent dye probes, we show that ultraviolet B-induced peroxides can be inhibited by ascorbic acid. Ascorbic acid strongly blocks ERK1/2 and p38 activation by ultraviolet B and hydrogen peroxide whereas pyrrolidine dithiocarbamate and butyl hydroxyanisole are less effective. Pyrrolidine dithiocarbamate was unable to inhibit ultraviolet B-induced p38 activation. Cell death was increased after ultraviolet B when ERK1/2 activation was attenuated by the specific inhibitor PD098059. The distinct time courses and extents of activation and inhibition of ERK1/2 and p38 indicate that these pathways are separate and regulated independently in keratinocytes. Specific types of reactive oxygen species induced by ultraviolet B as well as selective activation or inhibition of specific phosphatases may mediate these responses in keratinocytes. These findings demonstrate that reactive oxygen species are important multifunctional mediators of ultraviolet B-induced ERK1/2 and p38 signaling transduction pathways and suggest that ERK1/2 may play an important part in protecting keratinocytes from cell death following oxidative stress.

Original languageEnglish (US)
Pages (from-to)751-756
Number of pages6
JournalJournal of Investigative Dermatology
Issue number5
StatePublished - 1999


  • Extracellular regulated kinase
  • Hydrogen peroxide
  • Keratinocytes
  • Mitogen- activated protein kinase
  • P38
  • Reactive oxygen species
  • Ultraviolet B

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Dermatology
  • Cell Biology


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