Expression of integrin beta1 by fibroblasts is required for tissue repair in vivo

J Cell Sci. 2010 Nov 1;123(Pt 21):3674-82. doi: 10.1242/jcs.070672. Epub 2010 Oct 12.

Abstract

In tissue repair, fibroblasts migrate into the wound to produce and remodel extracellular matrix (ECM). Integrins are believed to be crucial for tissue repair, but their tissue-specific role in this process is poorly understood. Here, we show that mice containing a fibroblast-specific deletion of integrin β1 exhibit delayed cutaneous wound closure and less granulation tissue formation, including reduced production of new ECM and reduced expression of α-smooth muscle actin (α-SMA). Integrin-β1-deficient fibroblasts showed reduced expression of type I collagen and connective tissue growth factor, and failed to differentiate into myofibroblasts as a result of reduced α-SMA stress fiber formation. Loss of integrin β1 in adult fibroblasts reduced their ability to adhere to, to spread on and to contract ECM. Within stressed collagen matrices, integrin-β1-deficient fibroblasts showed reduced activation of latent TGFβ. Addition of active TGFβ alleviated the phenotype of integrin-β1-deficient mice. Thus integrin β1 is essential for normal wound healing, where it acts, at least in part, through a TGFβ-dependent mechanism in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Actins / metabolism
  • Animals
  • Cell Differentiation / genetics
  • Cells, Cultured
  • Collagen Type I / biosynthesis
  • Collagen Type I / genetics
  • Connective Tissue Growth Factor / genetics
  • Connective Tissue Growth Factor / metabolism
  • Fibroblasts / metabolism*
  • Fibroblasts / pathology
  • Focal Adhesions / genetics
  • Gene Expression Regulation / genetics
  • Humans
  • Integrin beta1 / genetics
  • Integrin beta1 / metabolism*
  • Mice
  • Mice, Knockout
  • Myofibroblasts / metabolism*
  • Myofibroblasts / pathology
  • Sequence Deletion / genetics
  • Skin / injuries
  • Skin / metabolism*
  • Skin / pathology
  • Stress Fibers / genetics
  • Stress Fibers / metabolism*
  • Wound Healing

Substances

  • Acta2 protein, mouse
  • Actins
  • Collagen Type I
  • Integrin beta1
  • Connective Tissue Growth Factor