Vascular endothelial growth factor induces VE-cadherin tyrosine phosphorylation in endothelial cells

Abstract

Interendothelial junctions play an important role in the regulation of endothelial functions, such as vasculogenesis, angiogenesis, and vascular permeability. In this paper we show that vascular endothelial growth factor (VEGF), a potent inducer of new blood vessels and vascular permeability in vivo, stimulated the migration of endothelial cells after artificial monolayer wounding and induced an increase in paracellular permeability of human umbilical vein endothelial cells (HUVECs). Furthermore, VEGF increased phosphotyrosine labeling at cell-cell contacts. Biochemical analyses revealed a strong induction of VEGF-receptor-2 (flk-1/KDR) tyrosine-autophosphorylation by VEGF which was maximal after 5 minutes and was followed by receptor downregulation. 15 minutes to 1 hour after VEGF stimulation the endothelial adherens junction components VE-cadherin, beta-catenin, plakoglobin, and p120 were maximally phosphorylated on tyrosine, while alpha-catenin was not modified. PECAM-1/CD31, another cell-cell junctional adhesive molecule, was tyrosine phosphorylated with similar kinetics in response to VEGF. In contrast, activation of VEGF-receptor-1 (Flt-1) by its specific ligand placenta growth factor (PlGF) had no effect on the tyrosine phosphorylation of cadherins and catenins. Despite the rapid and transient receptor activation and the subsequent tyrosine phosphorylation of adherens junction proteins the cadherin complex remained stable and associated with junctions. Our results demonstrate that the endothelial adherens junction is a downstream target of VEGFR-2 signaling and suggest that tyrosine phosphorylation of its components may be involved in the the loosening of cell-cell contacts in established vessels to modulate transendothelial permeability and to allow sprouting and cell migration during angiogenesis.

Protein Kinase C-related Kinase and ROCK Are Required for Thrombin-induced Endothelial Cell Permeability Downstream from Gα12/13 and Gα11/q

“…In addition, while both permeability factors led to tyrosine phosphorylation of VEcadherin and reduction of VE-cadherin/β-catenin interaction, only VEGF promoted S665 phosphorylation of VE-cadherin and its further interaction with β-arrestin (Fig. 5C), as a hallmark for VE-cadherin adhesion internalization (30,39,40). Finally, both ROCK and PRK blockade reduced the effects of thrombin on VE-cadherin junctions, as the overall organization of the endothelial monolayer appeared less disrupted (Fig.…”

Breaking the VE‐cadherin bonds

“…In addition, S665 has been identified as a pivotal regulator of VE-cadherin exposure at the plasma membrane [5]. Of note, the vascular endothelial growth factor (VEGF) was demonstrated to trigger VEcadherin phosphorylation and remodeling in endothelial cells [20]. Similarly, most of the PIFs tested so far are associated with an increase in VE-cadherin tyrosine phosphorylation and diminution of VEcadherin/catenin binding.…”

MAGI1, a Scaffold Protein with Tumor Suppressive and Vascular Functions

“…Under conditions of tissue damage, acute inflammation and vascular injury, there is an increase in vascular permeability for plasma accompanied by increased adhesion of leukocytes to the endothelium and extravasation [85]. Importantly, increased vascular permeability and leukocyte extravasation is promoted by the loosening of EC-EC contacts [86], following tyrosine phosphorylation of VE-cadherin, which can be induced by several factors, in particular vascular endothelial growth factor (VEGF) [87]. VE-cadherin is required for the recruitment of MAGI1, and together with Rap1, they finely modulate endothelial responses and barrier function [43,85].…”