Endothelial cell spreading on type IV collagen and spreading-induced FAK phosphorylation is regulated by Ca2+ influx.
The interaction of endothelial cells with their basement membrane and local stroma is highly regulated. The observation that CAI, an inhibitor of Ca++ influx, inhibited human umbilical vein endothelial cell (HUVEC) adhesion suggested that Ca++ influx was a regulator of HUVEC-matrix interaction. Exposure of HUVEC cells to CAI or SK&F 96365, another Ca++ influx inhibitor, selectively blocked spreading but not attachment on type IV collagen but not type I collagen. Ca++ influx blockade also prevented spreading-induced FAK phosphorylation and kinase activity and secondary paxillin phosphorylation. No inhibitory effect was observed when the cells spread on type I collagen. The inhibitory effect of CAI on spreading and spreading-associated FAK phosphorylation and kinase activity was reversible. These data indicate that HUVEC cells have a selective requirement for Ca++ influx for spreading and downstream signaling on basement membrane type IV collagen.
Molecular Signaling Section, National Cancer Institute, Bethesda, Maryland 20892, USA.
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Alessandro
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Masiero
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Lapidos
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Spoonster
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Kohn
D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D014230:Triazoles / Q000494:pharmacology; D014471:Umbilical Veins
D002121:Calcium Channel Blockers; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D007093:Imidazoles; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D014230:Triazoles; C062058:carboxyamido-triazole; D003094:Collagen; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D002118:Calcium