Inflammation-induced subcellular redistribution of VE-cadherin, actin, and gamma-catenin in cultured human lung microvessel endothelial cells.
The inflammation-induced subcellular redistribution of key cytoskeletal and junctional proteins in cultured human lung microvessel endothelial cells is investigated as part of a study on the posttranslational regulation of paracellular permeability. Inflammatory agonist-stimulated cells are detergent fractionated into three subcellular compartments followed by quantitative immunoblot analysis. Actin, gamma-catenin, and VE-cadherin increasingly associate with the cytoskeletal fraction upon thrombin stimulation. Concomitantly, actin is reduced in the cytosol fraction, whereas gamma-catenin and VE-cadherin are reduced in the membrane fraction. alpha- and beta-catenin show baseline distributions similar to those of VE-cadherin and gamma-catenin, but do not significantly redistribute. Additionally, vimentin is found exclusively in the cytoskeletal fraction and also does not significantly redistribute following thrombin treatment. The VE-cadherin response is independent of the presence of F-actin or actin redistribution. Immunofluorescence microscopy reveals that membrane and cytoskeletal VE-cadherin is present in alternating patches along the cell junctions. Furthermore, VE-cadherin is lost from zones of interendothelial cell pore formation. A model is formulated describing these membrane-associated VE-cadherin patches as predetermined zones of potential intercellular gap formation. During inflammation, VE-cadherin is lost from these zones and sequestered at the remaining cell-cell contact sites, anchored to the cytoskeleton in an actin-independent fashion.
Lim
M J
MJ
Microvascular Research Laboratory, Boston University, 5 Cummington Street, Boston, Massachusetts 02215, USA.
Chiang
E T
ET
Hechtman
H B
HB
Shepro
D
D
D000199:Actins / Q000378:metabolism*; D015703:Antigens, CD; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000378:metabolism; D002451:Cell Compartmentation / Q000276:immunology; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000187:drug effects* / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D051180:Desmoplakins; D004730:Endothelium, Vascular / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D007365:Intercellular Junctions / Q000737:chemistry / Q000187:drug effects / Q000276:immunology; D008168:Lung / Q000098:blood supply*; D008856:Microscopy, Fluorescence; D013917:Thrombin / Q000494:pharmacology; D013997:Time Factors; D051185:gamma Catenin; D000099152:Cadherin 5
D000199:Actins; D015703:Antigens, CD; D015820:Cadherins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D013917:Thrombin; D051185:gamma Catenin; D000099152:Cadherin 5; C495292:JUP protein, human