Platelet-activating factor increases VE-cadherin tyrosine phosphorylation in mouse endothelial cells and its association with the PtdIns3'-kinase

FASEB J. 2005 Apr;19(6):512-20. doi: 10.1096/fj.04-2202com.

Abstract

Platelet-activating factor (PAF), a potent inflammatory mediator, is involved in endothelial permeability. This study was designed to characterize PAF receptor (PAF-R) expression and its specific contribution to the modifications of adherens junctions in mouse endothelial cells. We demonstrated that PAF-R was expressed in mouse endothelial cells and was functionally active in stimulating p42/p44 MAPK and phosphatidylinositol 3-kinase (PtdIns3'-kinase)/Akt activities. Treatment of cells with PAF induced a rapid time- and dose-dependent (10(-7) to 10(-10) M) increase in tyrosine phosphorylation of a subset of proteins ranging from 90 to 220 kDa, including the VE-cadherin, the latter effect being prevented by the tyrosine kinase inhibitors herbimycin A and bis-tyrphostin. We demonstrated that PAF promoted formation of multimeric aggregates of VE-cadherin with PtdIns3'-kinase, which was also inhibited by herbimycin and bis-tyrphostin. Finally, we show by immunostaining of endothelial cells VE-cadherin that PAF dissociated adherens junctions. The present data provide the first evidence that treatment of endothelial cells with PAF promoted activation of tyrosine kinases and the VE-cadherin tyrosine phosphorylation and PtdIns3'-kinase association, which ultimately lead to the dissociation of adherens junctions. Physical association between PtdIns3'-kinase, serving as a docking protein, and VE-cadherin may thus provide an efficient mechanism for amplification and perpetuation of PAF-induced cellular activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / drug effects
  • Adherens Junctions / ultrastructure
  • Animals
  • Antigens, CD
  • Benzoquinones
  • Cadherins / chemistry
  • Cadherins / metabolism*
  • Cell Line
  • Embryo, Mammalian
  • Endothelial Cells / chemistry
  • Endothelial Cells / metabolism*
  • Endothelial Cells / ultrastructure
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / pharmacology
  • Fluorescent Antibody Technique
  • Heart
  • Immunosorbent Techniques
  • Intracellular Signaling Peptides and Proteins / pharmacology
  • Lactams, Macrocyclic
  • Mice
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation
  • Platelet Activating Factor / pharmacology*
  • Platelet Membrane Glycoproteins / analysis
  • Platelet Membrane Glycoproteins / genetics
  • Platelet Membrane Glycoproteins / physiology
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Protein-Tyrosine Kinases / metabolism
  • Quinones / pharmacology
  • RNA, Messenger / analysis
  • Receptors, G-Protein-Coupled / analysis
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / physiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Rifabutin / analogs & derivatives
  • Tyrosine / metabolism*
  • Tyrphostins / pharmacology

Substances

  • Antigens, CD
  • Benzoquinones
  • Cadherins
  • Enzyme Inhibitors
  • Intracellular Signaling Peptides and Proteins
  • Lactams, Macrocyclic
  • Platelet Activating Factor
  • Platelet Membrane Glycoproteins
  • Quinones
  • RNA, Messenger
  • Receptors, G-Protein-Coupled
  • Tyrphostins
  • cadherin 5
  • platelet activating factor receptor
  • protein kinase modulator
  • Rifabutin
  • Tyrosine
  • herbimycin
  • Phosphatidylinositol 3-Kinases
  • Protein-Tyrosine Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3