Beta-arrestin 2 is required for the induction and strengthening of integrin-mediated leukocyte adhesion during CXCR2-driven extravasation

Blood. 2009 Jul 30;114(5):1073-82. doi: 10.1182/blood-2008-10-183699. Epub 2009 May 8.

Abstract

Leukocyte extravasation involves interdependent signaling pathways underlying the complex dynamics of firm adhesion, crawling, and diapedesis. While signal transduction by agonist-bound chemokine receptors plays a central role in the above responses, it is unclear how it contributes to the sustained and concurrent nature of such responses, given the rapid kinetics of chemokine-induced trimeric G protein coupling and homologous desensitization. Our findings unveil a novel role of beta-arrestins in regulating the activation of signaling pathways underlying discrete integrin-mediated steps in CXCR2-driven leukocyte extravasation. By combining in vivo approaches in beta-arrestin knockout mice with in vitro studies in engineered cellular models, we show that membrane-recruited beta-arrestin 2 is required for the onset and maintenance of shear stress-resistant leukocyte adhesion mediated by both beta(1) and beta(2) integrins. While both beta-arrestin isoforms are required for rapid keratinocyte-derived chemokine (KC)-induced arrest onto limiting amounts of vascular cell adhesion molecule-1 (VCAM-1), adhesion strengthening under shear is selectively dependent on beta-arrestin 2. The latter synergizes with phospholipase C in promoting activation of Rap1A and B, both of which co-operatively control subsecond adhesion as well as postarrest adhesion stabilization. Thus, receptor-induced Galpha(i) and beta-arrestins act sequentially and in spatially distinct compartments to promote optimal KC-induced integrin-dependent adhesion during leukocyte extravasation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestins / deficiency
  • Arrestins / genetics
  • Arrestins / physiology*
  • Cell Adhesion / physiology
  • Cell Line, Tumor / drug effects
  • Cell Line, Tumor / metabolism
  • DNA, Complementary / genetics
  • Integrin alpha4beta1 / physiology
  • Keratinocytes / physiology
  • Leukemia, Basophilic, Acute / pathology
  • Leukocyte Rolling / physiology*
  • Leukocytes / cytology*
  • Male
  • Mice
  • Mice, Knockout
  • Myeloid Cells / metabolism
  • RNA, Small Interfering / pharmacology
  • Rats
  • Receptors, Interleukin-8B / genetics
  • Receptors, Interleukin-8B / physiology*
  • Recombinant Fusion Proteins / physiology
  • Shear Strength
  • Vascular Cell Adhesion Molecule-1 / metabolism
  • Venules
  • beta-Arrestin 2
  • beta-Arrestins

Substances

  • Arrb2 protein, mouse
  • Arrb2 protein, rat
  • Arrestins
  • DNA, Complementary
  • Integrin alpha4beta1
  • RNA, Small Interfering
  • Receptors, Interleukin-8B
  • Recombinant Fusion Proteins
  • Vascular Cell Adhesion Molecule-1
  • beta-Arrestin 2
  • beta-Arrestins