Skin lesion development in a mouse model of incontinentia pigmenti is triggered by NEMO deficiency in epidermal keratinocytes and requires TNF signaling

Hum Mol Genet. 2006 Feb 15;15(4):531-42. doi: 10.1093/hmg/ddi470. Epub 2006 Jan 6.


NF-kappaB essential modulator (NEMO), the regulatory subunit of the IkappaB kinase, is essential for NF-kappaB activation. Mutations disrupting the X-linked NEMO gene cause incontinentia pigmenti (IP), a human genetic disease characterized by male embryonic lethality and by a complex pathology affecting primarily the skin in heterozygous females. The cellular and molecular mechanisms leading to skin lesion pathogenesis in IP patients remain elusive. Here we used epidermis-specific deletion of NEMO in mice to investigate the mechanisms causing the skin pathology in IP. NEMO deletion completely inhibited NF-kappaB activation and sensitized keratinocytes to tumor necrosis factor (TNF)-induced death but did not affect epidermal development. Keratinocyte-restricted NEMO deletion, either constitutive or induced in adult skin, caused inflammatory skin lesions, identifying the NEMO-deficient keratinocyte as the initiating cell type that triggers the skin pathology in IP. Furthermore, genetic ablation of tumor necrosis factor receptor 1 (TNFRI) rescued the skin phenotype demonstrating that TNF signaling is essential for skin lesion pathogenesis in IP. These results identify the NEMO-deficient keratinocyte as a potent initiator of skin inflammation and provide novel insights into the mechanism leading to the pathogenesis of IP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Epidermis / metabolism*
  • Epidermis / pathology
  • Female
  • Genes, X-Linked / genetics
  • Genetic Diseases, X-Linked / genetics
  • Genetic Diseases, X-Linked / metabolism*
  • Genetic Diseases, X-Linked / pathology
  • Humans
  • I-kappa B Kinase / deficiency*
  • I-kappa B Kinase / metabolism
  • Incontinentia Pigmenti / genetics
  • Incontinentia Pigmenti / metabolism*
  • Incontinentia Pigmenti / pathology
  • Inflammation / genetics
  • Inflammation / metabolism
  • Inflammation / pathology
  • Keratinocytes / metabolism*
  • Keratinocytes / pathology
  • Male
  • Mice
  • NF-kappa B / metabolism
  • Signal Transduction / genetics*


  • IKBKG protein, human
  • NF-kappa B
  • I-kappa B Kinase