VEGF increases permeability of the endothelial cell monolayer by activation of PKB/akt, endothelial nitric-oxide synthase, and MAP kinase pathways

Microvasc Res. 2001 Nov;62(3):252-62. doi: 10.1006/mvre.2001.2338.

Abstract

VEGF is a key regulator of vascular permeability. However, its signaling pathways are incompletely understood. We tested the hypothesis that VEGF regulates endothelial cell (EC) permeability by activating PKB/akt, NOS, and MAP kinase dependent pathways using human umbilical vein EC (HUVEC). Permeability was measured from FITC-dextran 70-kDa flux across the EC monolayer at baseline and after VEGF at 0.034, 0.068, 1, 10, and 100 nM. VEGF increased HUVEC permeability to FITC-dextran in a dose-dependent manner. VEGF (1 nM) increased permeability from 3.9 x 10(-6) +/- 0.7 x 10(-6) to 14.0 x 10(-6) +/- 1.7 x 10(-6) cm/s (mean +/- SEM; P < 0.001). Permeability changes were also assessed after treatment with 1, 10, and 100 nM wortmannin (PI 3-kinase inhibitor); 0.01, 0.1, and 1.0 nM LY294002 (PI 3-kinase inhibitor); 200 microM l-NMMA (NOS inhibitor); 2.7 microM AG126 (p42/44(MAPK) inhibitor); and 0.006, 0.06, and 0.6 microM SB203580 (p38(MAPK) inhibitor). All inhibitors blocked VEGF-induced permeability changes. Our data demonstrate that (1) VEGF increases permeability of EC monolayers in a dose-dependent fashion, and (2) VEGF-induced permeability is mediated through PI-3 kinase-PKB, NOS, and MAP-kinase signaling cascades. These observations suggest that microvascular hyperpermeability associated with inflammation and vascular disease is mediated by activation of these EC signaling pathways.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Capillary Permeability / drug effects*
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Endothelial Growth Factors / pharmacology*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / enzymology*
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Infant, Newborn
  • Kinetics
  • Lymphokines / pharmacology*
  • MAP Kinase Signaling System / physiology*
  • Nitric Oxide Synthase / drug effects
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type III
  • Protein-Serine-Threonine Kinases*
  • Protein-Tyrosine Kinases / drug effects
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / drug effects
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • Umbilical Veins / cytology
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors

Substances

  • Endothelial Growth Factors
  • Enzyme Inhibitors
  • Lymphokines
  • Proto-Oncogene Proteins
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • NOS3 protein, human
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type III
  • Protein-Tyrosine Kinases
  • AKT1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt