ERK1/2 regulates epidermal chemokine expression and skin inflammation

J Immunol. 2005 Apr 15;174(8):5047-56. doi: 10.4049/jimmunol.174.8.5047.

Abstract

Resident cell populations of the skin contribute to the inflammatory response by producing an array of chemokines, which attract leukocytes from the circulation. TNF-alpha is a major inducer of proinflammatory mediators in keratinocytes. We have recently observed that epidermal growth factor receptor (EGFR) signaling affects TNF-alpha-driven chemokine expression in epidermal keratinocytes, and its functional impairment increases the levels of crucial chemoattractants such as CCL2/MCP-1, CCL5/RANTES, and CXCL10/IFN-gamma-inducible protein-10. In this study, we report evidence that EGFR-dependent ERK1/2 activity is implicated in this mechanism. Abrogation of ERK1/2 activity with specific inhibitors increased chemokine expression in keratinocytes by enhancing mRNA stabilization. In mouse models, inflammatory response to irritants and T cell-mediated contact hypersensitivity were both aggravated when elicited in a skin area previously treated with an EGFR or a MAPK kinase 1/2 inhibitor. In contrast, impairment of p38alpha beta MAPK phosphorylation markedly attenuated these responses. Our data indicate that EGFR-dependent ERK1/2 activity in keratinocytes takes part to a homeostatic mechanism regulating inflammatory responses, and emphasize the distinct role of MAPKs as potential targets for manipulating inflammation in the skin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemokines / genetics*
  • Dermatitis, Contact / enzymology*
  • Dermatitis, Contact / genetics
  • Dermatitis, Contact / immunology*
  • Dermatitis, Contact / pathology
  • Enzyme Inhibitors / pharmacology
  • ErbB Receptors / antagonists & inhibitors
  • ErbB Receptors / metabolism
  • Extracellular Signal-Regulated MAP Kinases
  • Gene Expression Regulation / drug effects
  • Humans
  • Inflammation Mediators / metabolism
  • Keratinocytes / drug effects
  • Keratinocytes / enzymology
  • Keratinocytes / immunology
  • Keratinocytes / pathology
  • MAP Kinase Signaling System
  • Mice
  • Mice, Inbred BALB C
  • Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • RNA Stability / drug effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Skin / drug effects
  • Skin / enzymology*
  • Skin / immunology*
  • Skin / pathology
  • Transcription Factor AP-1 / genetics
  • Transcriptional Activation

Substances

  • Chemokines
  • Enzyme Inhibitors
  • Inflammation Mediators
  • RNA, Messenger
  • Transcription Factor AP-1
  • ErbB Receptors
  • Extracellular Signal-Regulated MAP Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3