Selective inhibition of vascular endothelial growth factor receptor-2 (VEGFR-2) identifies a central role for VEGFR-2 in human aortic endothelial cell responses to VEGF

J Recept Signal Transduct Res. 2003;23(2-3):239-54. doi: 10.1081/rrs-120025567.

Abstract

Vascular endothelial growth factor receptors (VEGFR) are considered essential for angiogenesis. The VEGFR-family proteins consist of VEGFR-1/Flt-1, VEGFR-2/KDR/Flk-1, and VEGFR-3/Flt-4. Among these, VEGFR-2 is thought to be principally responsible for angiogenesis. However, the precise role of VEGFRs1-3 in endothelial cell biology and angiogenesis remains unclear due in part to the lack of VEGFR-specific inhibitors. We used the newly described, highly selective anilinoquinazoline inhibitor of VEGFR-2 tyrosine kinase, ZM323881 (5-[[7-(benzyloxy) quinazolin-4-yl]amino]-4-fluoro-2-methylphenol), to explore the role of VEGFR-2 in endothelial cell function. Consistent with its reported effects on VEGFR-2 [IC(50) < 2 nM], ZM323881 inhibited activation of VEGFR-2, but not of VEGFR-1, epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), or hepatocyte growth factor (HGF) receptor. We studied the effects of VEGF on human aortic endothelial cells (HAECs), which express VEGFR-1 and VEGFR-2, but not VEGFR-3, in the absence or presence of ZM323881. Inhibition of VEGFR-2 blocked activation of extracellular regulated-kinase, p38, Akt, and endothelial nitric oxide synthetase (eNOS) by VEGF, but did not inhibit p38 activation by the VEGFR-1-specific ligand, placental growth factor (PIGF). Inhibition of VEGFR-2 also perturbed VEGF-induced membrane extension, cell migration, and tube formation by HAECs. Vascular endothelial growth factor receptor-2 inhibition also reversed VEGF-stimulated phosphorylation of CrkII and its Src homology 2 (SH2)-binding protein p130Cas, which are known to play a pivotal role in regulating endothelial cell migration. Inhibition of VEGFR-2 thus blocked all VEGF-induced endothelial cellular responses tested, supporting that the catalytic activity of VEGFR-2 is critical for VEGF signaling and/or that VEGFR-2 may function in a heterodimer with VEGFR-1 in human vascular endothelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / anatomy & histology*
  • Cell Membrane / metabolism
  • Cell Movement / physiology
  • Crk-Associated Substrate Protein
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Endothelium, Vascular / cytology*
  • Endothelium, Vascular / metabolism
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Mice
  • NIH 3T3 Cells
  • Nitric Oxide Synthase / metabolism
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Protein-Serine-Threonine Kinases*
  • Proteins / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Quinazolines / pharmacology
  • Receptor Protein-Tyrosine Kinases / antagonists & inhibitors
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • Retinoblastoma-Like Protein p130
  • Signal Transduction / physiology
  • Vascular Endothelial Growth Factor A / metabolism*
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism*

Substances

  • BCAR1 protein, human
  • Bcar1 protein, mouse
  • Crk-Associated Substrate Protein
  • Enzyme Inhibitors
  • Proteins
  • Proto-Oncogene Proteins
  • Quinazolines
  • Retinoblastoma-Like Protein p130
  • Vascular Endothelial Growth Factor A
  • ZM323881
  • NOS3 protein, human
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Nos3 protein, mouse
  • Receptor Protein-Tyrosine Kinases
  • Receptors, Platelet-Derived Growth Factor
  • Vascular Endothelial Growth Factor Receptor-2
  • AKT1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt