From Hyperactive Connexin26 Hemichannels to Impairments in Epidermal Calcium Gradient and Permeability Barrier in the Keratitis-Ichthyosis-Deafness Syndrome

J Invest Dermatol. 2016 Mar;136(3):574-583. doi: 10.1016/j.jid.2015.11.017. Epub 2016 Jan 8.

Abstract

The keratitis-ichthyosis-deafness (KID) syndrome is characterized by corneal, skin, and hearing abnormalities. KID has been linked to heterozygous dominant missense mutations in the GJB2 and GJB6 genes, encoding connexin26 and 30, respectively. In vitro evidence indicates that KID mutations lead to hyperactive (open) hemichannels, which in some cases is accompanied by abnormal function of gap junction channels. Transgenic mouse models expressing connexin26 KID mutations reproduce human phenotypes and present impaired epidermal calcium homeostasis and abnormal lipid composition of the stratum corneum affecting the water barrier. Here we have compiled relevant data regarding the KID syndrome and propose a mechanism for the epidermal aspects of the disease.

Keywords: Cx; GJCs; HCs; KID; PPK; connexin; gap junction channels; hemichannels; keratitis-ichthyosis-deafness; palmoplantar keratoderma.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Calcium Channels / genetics*
  • Cell Membrane Permeability / genetics
  • Connexin 26
  • Connexins / genetics*
  • Epidermis / metabolism*
  • Gap Junctions / metabolism
  • Genetic Predisposition to Disease*
  • Humans
  • Keratitis / genetics*
  • Mice
  • Mice, Transgenic
  • Mutation, Missense
  • Water-Electrolyte Imbalance / genetics
  • Water-Electrolyte Imbalance / physiopathology

Substances

  • Calcium Channels
  • Connexins
  • GJB2 protein, human
  • Gjb2 protein, mouse
  • Connexin 26

Supplementary concepts

  • Keratitis-Ichthyosis-Deafness Syndrome