VEGF stimulates tyrosine phosphorylation of beta-catenin and small-pore endothelial barrier dysfunction.
The purpose of this study was to test the hypothesis that tyrosine phosphorylation signaling events and protein kinase C (PKC) activation mediate vascular endothelial growth factor-A(165) (VEGF)-induced endothelial cell (EC) proliferation and barrier dysfunction in bovine pulmonary artery EC monolayers. A size-selective permeability assay showed that VEGF stimulated a delayed, prolonged (6-45 h), concentration-dependent (50-200 ng/ml, approximately 1-4 nM) increase in the number of predominantly small-"pore" transport pathways (<60 A) across EC monolayers. The tyrosine kinase inhibitor herbimycin A (HA) and the selective PKC inhibitor bisindolylmaleimide (BIM) prevented this phenomenon. After 6-24 h, VEGF-treated monolayers displayed an HA- and BIM-sensitive reorganization of beta-catenin adherens junctions with fingerlike projections and the loss of beta-catenin at sites of small paracellular hole formation. HA and BIM prevented the VEGF-induced increase in EC growth. HA blocked the VEGF-induced rapid and prolonged (10 min-45 h) increases in the phosphotyrosine (PY) contents of VEGF receptor 2, phospholipase C-gamma1, paxillin, and beta-catenin as well as approximately 140- and 128- to 117-kDa proteins, whereas BIM inhibited only the tyrosine phosphorylation of beta-catenin. These data suggest that VEGF initiates increased EC growth and chronic, small-pore endothelial barrier dysfunction by PY signaling through beta-catenin that depends on PKC.
Cohen
A W
AW
Department of Physiology, University of Arizona, Tucson, Arizona 85723, USA.
Carbajal
J M
JM
Schaeffer
R C
RC
D000205:Actomyosin / Q000502:physiology; D000818:Animals; D016227:Benzoquinones; D001692:Biological Transport / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects*; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007365:Intercellular Junctions / Q000187:drug effects / Q000502:physiology; D047029:Lactams, Macrocyclic; D008222:Lymphokines / Q000494:pharmacology*; D008301:Maleimides / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011809:Quinones / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D017828:Rifabutin / Q000031:analogs & derivatives; D013997:Time Factors; D015534:Trans-Activators; D014443:Tyrosine / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D051176:beta Catenin
D016227:Benzoquinones; D003598:Cytoskeletal Proteins; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D007211:Indoles; D047029:Lactams, Macrocyclic; D008222:Lymphokines; D008301:Maleimides; D011809:Quinones; D017978:Receptors, Growth Factor; D015534:Trans-Activators; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D051176:beta Catenin; D017828:Rifabutin; D014443:Tyrosine; C020754:herbimycin; D000205:Actomyosin; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; C088060:bisindolylmaleimide