Targeting β1-integrin inhibits vascular leakage in endotoxemia

Proc Natl Acad Sci U S A. 2018 Jul 10;115(28):E6467-E6476. doi: 10.1073/pnas.1722317115. Epub 2018 Jun 25.

Abstract

Loss of endothelial integrity promotes capillary leakage in numerous diseases, including sepsis, but there are no effective therapies for preserving endothelial barrier function. Angiopoietin-2 (ANGPT2) is a context-dependent regulator of vascular leakage that signals via both endothelial TEK receptor tyrosine kinase (TIE2) and integrins. Here, we show that antibodies against β1-integrin decrease LPS-induced vascular leakage in murine endotoxemia, as either a preventative or an intervention therapy. β1-integrin inhibiting antibodies bound to the vascular endothelium in vivo improved the integrity of endothelial cell-cell junctions and protected mice from endotoxemia-associated cardiac failure, without affecting endothelial inflammation, serum proinflammatory cytokine levels, or TIE receptor signaling. Moreover, conditional deletion of a single allele of endothelial β1-integrin protected mice from LPS-induced vascular leakage. In endothelial monolayers, the inflammatory agents thrombin, lipopolysaccharide (LPS), and IL-1β decreased junctional vascular endothelial (VE)-cadherin and induced actin stress fibers via β1- and α5-integrins and ANGPT2. Additionally, β1-integrin inhibiting antibodies prevented inflammation-induced endothelial cell contractility and monolayer permeability. Mechanistically, the inflammatory agents stimulated ANGPT2-dependent translocation of α5β1-integrin into tensin-1-positive fibrillar adhesions, which destabilized the endothelial monolayer. Thus, β1-integrin promotes endothelial barrier disruption during inflammation, and targeting β1-integrin signaling could serve as a novel means of blocking pathological vascular leak.

Keywords: ANGPT2; TIE2; permeability; sepsis; β1-integrin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / metabolism
  • Cadherins / genetics
  • Cadherins / metabolism
  • Disease Models, Animal
  • Endothelial Cells / metabolism*
  • Endothelial Cells / pathology
  • Endotoxemia / chemically induced
  • Endotoxemia / genetics
  • Endotoxemia / metabolism*
  • Endotoxemia / pathology
  • Integrin alpha5beta1 / genetics
  • Integrin alpha5beta1 / metabolism
  • Integrin beta1 / genetics
  • Integrin beta1 / metabolism*
  • Intercellular Junctions / genetics
  • Intercellular Junctions / metabolism*
  • Intercellular Junctions / pathology
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Lipopolysaccharides / toxicity
  • Mice
  • Mice, Transgenic
  • Protein Transport / drug effects
  • Protein Transport / genetics
  • Receptor, TIE-2 / genetics
  • Receptor, TIE-2 / metabolism

Substances

  • Antigens, CD
  • Cadherins
  • IL1B protein, mouse
  • Integrin alpha5beta1
  • Integrin beta1
  • Interleukin-1beta
  • Lipopolysaccharides
  • cadherin 5
  • Receptor, TIE-2
  • Tek protein, mouse