Lack of nidogen-1 and -2 prevents basement membrane assembly in skin-organotypic coculture

J Invest Dermatol. 2007 Mar;127(3):545-54. doi: 10.1038/sj.jid.5700562. Epub 2006 Sep 28.

Abstract

Nidogens are considered as classical linkers joining laminin and collagen IV networks in basement membranes (BMs); however, recent genetic approaches have suggested that nidogens function in a tissue-specific and developmental context. Thus, in mice lacking both nidogen-1 and -2 heart and lung were severely affected, causing neonatal death. Furthermore, in various locations, extravasation of erythrocytes was observed implying microvascular defects. Mice expressing solely either isoform, had a functional BM, although nidogen-2 binds with lower affinity to the laminin gamma1 chain. Having previously blocked BM formation by interfering with nidogen-1 binding to laminin in skin-organotypic cocultures, here we investigated the roles of nidogen-1 and -2 in this model. For that purpose, human HaCaT cells were grown in three-dimensional cocultures on collagen matrices containing murine fibroblasts of varying nidogen deficiency. As with our experiments blocking laminin-nidogen interaction, lack of both nidogens completely prevented BM deposition and ultrastructural assembly of BM and hemidesmosomes, although other BM proteins remained detectable at comparable levels with no signs of degradation. Supplementation by recombinant nidogen-1 or -2 restored these structures, as shown by immunofluorescence and electron microscopy, confirming that in this system nidogen-2 is equivalent to nidogen-1, and both can promote the development of a functional BM zone.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basement Membrane / metabolism*
  • Cell Adhesion Molecules / biosynthesis
  • Cell Adhesion Molecules / physiology*
  • Coculture Techniques
  • Collagen / chemistry
  • Dermis / metabolism
  • Epidermis / metabolism
  • Erythrocytes / metabolism
  • Fibroblasts / metabolism
  • Humans
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / physiology*
  • Mice
  • Organ Culture Techniques
  • Protein Isoforms
  • Skin / immunology*

Substances

  • Cell Adhesion Molecules
  • Membrane Glycoproteins
  • NID2 protein, human
  • Protein Isoforms
  • nidogen
  • Collagen