Contribution of vascular endothelial growth factor receptor-2 sialylation to the process of angiogenesis

Oncogene. 2017 Nov 23;36(47):6531-6541. doi: 10.1038/onc.2017.243. Epub 2017 Aug 7.

Abstract

Vascular endothelial growth factor receptor-2 (VEGFR2) is the main pro-angiogenic receptor expressed by endothelial cells (ECs). Using surface plasmon resonance, immunoprecipitation, enzymatic digestion, immunofluorescence and cross-linking experiments with specific sugar-binding lectins, we demonstrated that VEGFR2 bears both α,1-fucose and α(2,6)-linked sialic acid (NeuAc). However, only the latter is required for VEGF binding to VEGFR2 and consequent VEGF-dependent VEGFR2 activation and motogenic response in ECs. Notably, downregulation of β-galactoside α(2,6)-sialyltransferase expression by short hairpin RNA transduction inhibits VEGFR2 α(2,6) sialylation that is paralleled by an increase of β-galactoside α(2,3)-sialyltransferase expression. This results in an ex-novo α(2,3)-NeuAc sialylation of the receptor that functionally replaces the lacking α(2,6)-NeuAc, thus allowing VEGF/VEGFR2 interaction. In keeping with the role of VEGFR2 sialylation in angiogenesis, the α(2,6)-NeuAc-binding lectin Sambucus nigra (SNA) prevents VEGF-dependent VEGFR2 autophosphorylation and EC motility, proliferation and motogenesis. In addition, SNA exerts a VEGF-antagonist activity in tridimensional angiogenesis models in vitro and in the chick-embryo chorioallantoic membrane neovascularization assay and mouse matrigel plug assay in vivo. In conclusion, VEGFR2-associated NeuAc plays an important role in modulating VEGF/VEGFR2 interaction, EC pro-angiogenic activation and neovessel formation. VEGFR2 sialylation may represent a target for the treatment of angiogenesis-dependent diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Chick Embryo
  • Chorioallantoic Membrane
  • Down-Regulation
  • Endothelial Cells / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Galactosides
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • N-Acetylneuraminic Acid / metabolism
  • Neovascularization, Pathologic / metabolism*
  • Neovascularization, Physiologic
  • Phosphorylation / drug effects
  • Plant Lectins / pharmacology*
  • Protein Processing, Post-Translational*
  • RNA, Small Interfering
  • Ribosome Inactivating Proteins / pharmacology*
  • Sialyltransferases / genetics
  • Sialyltransferases / metabolism
  • Surface Plasmon Resonance
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors
  • Vascular Endothelial Growth Factor A / metabolism
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism*
  • beta-D-Galactoside alpha 2-6-Sialyltransferase
  • beta-Galactoside alpha-2,3-Sialyltransferase

Substances

  • Galactosides
  • Plant Lectins
  • RNA, Small Interfering
  • Sambucus nigra lectins
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • beta-galactoside
  • vascular endothelial growth factor A, mouse
  • Sialyltransferases
  • KDR protein, human
  • Kdr protein, mouse
  • Vascular Endothelial Growth Factor Receptor-2
  • Ribosome Inactivating Proteins
  • N-Acetylneuraminic Acid
  • beta-D-Galactoside alpha 2-6-Sialyltransferase
  • beta-Galactoside alpha-2,3-Sialyltransferase