Cell death-induced activation of epidermal growth factor receptor in keratinocytes: implications for restricting epidermal damage in dermatitis

J Invest Dermatol. 2005 Jul;125(1):134-42. doi: 10.1111/j.0022-202X.2005.23804.x.

Abstract

Recent findings have implicated Fas/Fas ligand (FasL) in mediating the death of keratinocytes in spongiotic lesions. We asked whether dying keratinocytes could potentially initiate a protective response of the skin to limit the destruction of the epidermis in the spongiotic areas. In addition to apoptosis, treatment of keratinocyte cultures in vitro with FasL triggers a profound phoshorylation of the epidermal growth factor receptor (EGFR) and of its downstream effectors ERK and protein kinase B (PKB/Akt). Using a variety of inhibitors and blocking antibodies, we demonstrated that: (i) apoptosis is required for the generation of the signal(s) leading to the activation of EGFR, ERK, and Akt; (ii) the activation of EGFR, ERK, and Akt by FasL is indeed mediated by its bona fide receptor Fas; (iii) the activation of EGFR is essential for the subsequent activation of ERK and Akt; and (iv) apoptotic keratinocytes secrete soluble EGFR ligands (including amphiregulin) that are processed from membrane-bound proligand forms by metalloproteinase(s). Our findings demonstrate a potential mechanism for the restriction and repair of spongiotic damage in eczemas.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis*
  • Cell Culture Techniques
  • Dermatitis / metabolism
  • Dermatitis / pathology
  • Dermatitis / physiopathology*
  • ErbB Receptors / metabolism*
  • Fas Ligand Protein
  • Humans
  • Keratinocytes / metabolism*
  • Membrane Glycoproteins / metabolism
  • Signal Transduction

Substances

  • FASLG protein, human
  • Fas Ligand Protein
  • Membrane Glycoproteins
  • ErbB Receptors