VEGF-induced mobilization of caveolae and increase in permeability of endothelial cells.
Glomerular epithelial cells (GEC) are a known site of vascular endothelial growth factor (VEGF) production. We established immortalized rat GEC, which retained the ability to produce VEGF. The isoforms expressed by GEC were defined as VEGF-205, -188, -120, and -164. The electrical resistance of endothelial cells cultured on GEC-conditioned matrix, an indicator of the permeability of monolayers to solutes, was significantly increased by the treatment with the neutralizing polyclonal antibodies to VEGF and decreased by VEGF-165. Transfection of endothelial cells with green fluorescence protein-caveolin construct and intravital confocal microscopy showed that VEGF results in a rapid appearance of transcellular elongated structures decorated with caveolin. Transmission electron microscopy of endothelial cells showed that caveolae undergo rapid internalization and fusion 30 min after application of VEGF-165. Later (36 h), endothelial cells pretreated with VEGF developed fenestrae and showed a decrease in electrical resistance. Immunoelectron microscopy of glomeruli confirmed VEGF localization to podocytes and in the basement membrane. In summary, immortalized GEC retain the ability to synthesize VEGF. Matrix-deposited and soluble VEGF leads to the enhancement of caveolae expression, their fission and fusion, formation of elongated caveolin-decorated structures, and eventual formation of fenestrae, both responsible for the increase in endothelial permeability.
Chen
Jun
J
Department of Medicine, University Microscopy Center, State University of New York, Stony Brook, New York 11794-8152, USA.
Braet
Filip
F
Brodsky
Sergey
S
Weinstein
Talia
T
Romanov
Victor
V
Noiri
Eisei
E
Goligorsky
Michael S
MS
D000818:Animals; D021941:Caveolae / Q000378:metabolism* / Q000648:ultrastructure; D051242:Caveolin 1; D022461:Caveolins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D025802:Electric Capacitance; D016228:Endothelial Growth Factors / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism*; D008222:Lymphokines / Q000378:metabolism*; D008564:Membrane Potentials / Q000502:physiology; D018613:Microscopy, Confocal; D010539:Permeability; D020033:Protein Isoforms; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
C495540:CAV1 protein, human; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins; D016228:Endothelial Growth Factors; D008222:Lymphokines; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors