Modulation of Rac1 activity by ADMA/DDAH regulates pulmonary endothelial barrier function

Mol Biol Cell. 2009 Jan;20(1):33-42. doi: 10.1091/mbc.e08-04-0395. Epub 2008 Oct 15.

Abstract

Endogenously produced nitric oxide synthase inhibitor, asymmetric methylarginine (ADMA) is associated with vascular dysfunction and endothelial leakage. We studied the role of ADMA, and the enzymes metabolizing it, dimethylarginine dimethylaminohydrolases (DDAH) in the regulation of endothelial barrier function in pulmonary macrovascular and microvascular cells in vitro and in lungs of genetically modified heterozygous DDAHI knockout mice in vivo. We show that ADMA increases pulmonary endothelial permeability in vitro and in in vivo and that this effect is mediated by nitric oxide (NO) acting via protein kinase G (PKG) and independent of reactive oxygen species formation. ADMA-induced remodeling of actin cytoskeleton and intercellular adherens junctions results from a decrease in PKG-mediated phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and a subsequent down-regulation of Rac1 activity. The effects of ADMA on endothelial permeability, Rac1 activation and VASP phosphorylation are prevented by overexpression of active DDAHI and DDAHII, whereas inactive DDAH mutants have no effect. These findings demonstrate for the first time that ADMA metabolism critically determines pulmonary endothelial barrier function by modulating Rac1-mediated remodeling of the actin cytoskeleton and intercellular junctions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / metabolism
  • Amidohydrolases / genetics
  • Amidohydrolases / metabolism*
  • Animals
  • Antigens, CD / metabolism
  • Arginine / analogs & derivatives*
  • Arginine / metabolism
  • Cadherins / metabolism
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism
  • Cells, Cultured
  • Cyclic GMP-Dependent Protein Kinases / metabolism
  • Cytoskeleton / metabolism
  • Endothelium / cytology
  • Endothelium / enzymology*
  • Enzyme Activation
  • Enzyme Inhibitors / metabolism*
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Lung / cytology*
  • Lung / metabolism
  • Mice
  • Mice, Knockout
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitric Oxide Synthase / metabolism
  • Permeability
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Reactive Oxygen Species / metabolism
  • Swine
  • cdc42 GTP-Binding Protein / genetics
  • cdc42 GTP-Binding Protein / metabolism
  • rac1 GTP-Binding Protein / genetics
  • rac1 GTP-Binding Protein / metabolism*
  • rhoA GTP-Binding Protein / genetics
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Antigens, CD
  • Cadherins
  • Cell Adhesion Molecules
  • Enzyme Inhibitors
  • Isoenzymes
  • Microfilament Proteins
  • Phosphoproteins
  • Reactive Oxygen Species
  • cadherin 5
  • vasodilator-stimulated phosphoprotein
  • Nitric Oxide
  • N,N-dimethylarginine
  • Arginine
  • Nitric Oxide Synthase
  • Cyclic GMP-Dependent Protein Kinases
  • Amidohydrolases
  • dimethylargininase
  • cdc42 GTP-Binding Protein
  • rac1 GTP-Binding Protein
  • rhoA GTP-Binding Protein