Vascular endothelial growth factor receptor-1 modulates vascular endothelial growth factor-mediated angiogenesis via nitric oxide

Am J Pathol. 2001 Sep;159(3):993-1008. doi: 10.1016/S0002-9440(10)61775-0.


The known responses of vascular endothelial growth factor (VEGF) are mediated through VEGF receptor-2 (VEGFR-2/KDR) in endothelial cells. However, it is unknown whether VEGFR-1 (Flt-1) is an inert decoy or a signaling receptor for VEGF during physiological or pathological angiogenesis. Here we report that VEGF-stimulated nitric oxide (NO) release is inhibited by blockade of VEGFR-1 and that VEGFR-1 via NO negatively regulates of VEGFR-2-mediated proliferation and promotes formation of capillary networks in human umbilical vein endothelial cells (HUVECs). Inhibition of VEGFR-1 in a murine Matrigel angiogenesis assay induced large aneurysm-like structures. VEGF-induced capillary growth over 14 days was inhibited by anti-VEGFR-2-blocking antibody as determined by reduced tube length between capillary connections (P < 0.0001) in an in vitro angiogenesis assay. In contrast, loss of VEGFR-1 activity with a neutralizing anti-VEGFR-1 antibody resulted in an increase in the accumulation of endothelial cells (P < 0.0001) and a dramatic decrease in the number of capillary connections that were restored by the addition of NO donor. Porcine aortic endothelial (PAE) cells expressing human VEGFR-1 but not VEGFR-2 plated on growth factor-reduced Matrigel rearranged into tube-like structures that were prevented by anti-VEGFR-1 antibody or a cGMP inhibitor. VEGF stimulated NO release from VEGFR-1- but not VEGFR-2-transfected endothelial cells and placenta growth factor-1 stimulated NO release in HUVECs. Blockade of VEGFR-1 increased VEGF-mediated HUVEC proliferation that was inhibited by NO donors, and potentiated by NO synthase inhibitors. These data indicate that VEGFR-1 is a signaling receptor that promotes endothelial cell differentiation into vascular tubes, in part by limiting VEGFR-2-mediated endothelial cell proliferation via NO, which seems to be a molecular switch for endothelial cell differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Division / drug effects
  • Cell Division / physiology
  • Cells, Cultured
  • Endothelial Growth Factors / pharmacology
  • Endothelial Growth Factors / physiology*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / physiology*
  • Humans
  • Lymphokines / pharmacology
  • Lymphokines / physiology*
  • Neovascularization, Physiologic / physiology*
  • Nitric Oxide / metabolism
  • Nitric Oxide / physiology*
  • Nitric Oxide Donors / pharmacology
  • Nitric Oxide Synthase / metabolism
  • Nitric Oxide Synthase Type III
  • Nitroso Compounds / pharmacology
  • Penicillamine / analogs & derivatives
  • Penicillamine / pharmacology
  • Protein Isoforms / immunology
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / immunology
  • Proto-Oncogene Proteins / physiology*
  • Receptor Protein-Tyrosine Kinases / antagonists & inhibitors
  • Receptor Protein-Tyrosine Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / immunology
  • Receptor Protein-Tyrosine Kinases / physiology*
  • Receptors, Growth Factor / genetics
  • Receptors, Growth Factor / physiology
  • Receptors, Vascular Endothelial Growth Factor
  • Transfection
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factor Receptor-1
  • Vascular Endothelial Growth Factors


  • Endothelial Growth Factors
  • Lymphokines
  • N-glucopyranosyl-N2-acetyl-S-nitrosopenicillaminamide
  • Nitric Oxide Donors
  • Nitroso Compounds
  • Protein Isoforms
  • Proto-Oncogene Proteins
  • Receptors, Growth Factor
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Nitric Oxide
  • NOS3 protein, human
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type III
  • Receptor Protein-Tyrosine Kinases
  • Receptors, Vascular Endothelial Growth Factor
  • Vascular Endothelial Growth Factor Receptor-1
  • Penicillamine