Linked Life Data

12167625

Source:http://linkedlifedata.com/resource/pubmed/id/12167625

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
2002-10-15
pubmed:abstractText
Microvascular permeability is mediated by (i) the caveolar transcytosis of molecules across endothelial cells and (ii) the paracellular movement of ions and nutrients. Recently, we derived Cav-1 (-/-) knock-out mice using standard homologous recombination techniques. These mice are viable but show a loss of endothelial cell caveolae and striking defects in caveolae-mediated endocytosis. Thus, a compensatory mechanism must be operating in these mice. One possible compensatory response would be an increase in the paracellular pathway, resulting in increased microvascular permeability. To test this hypothesis directly, we studied the microvascular permeability of Cav-1 null mice using a variety of complementary in vivo approaches. Radio-iodinated bovine serum albumin was injected into Cav-1-deficient mice, and its rate of clearance from the circulatory system was compared with that of wild type control mice. Our results indicate that iodinated bovine serum albumin is removed from the circulatory system of Cav-1-deficient mice at a substantially faster rate. To determine whether this defect is restricted to the paracellular movement of albumin, lungs from Cav-1-deficient mice were next perfused with the electron dense dye Ruthenium Red. Micrographs of lung endothelial cells from Cav-1-deficient mice demonstrate that the paracellular movement of Ruthenium Red is dramatically increased. In addition, electron micrographs of Cav-1-deficient lung capillaries reveal defects in tight junction morphology and abnormalities in capillary endothelial cell adhesion to the basement membrane. This defect in cell-substrate attachment is consistent with the postulated role of caveolin-1 in positively regulating integrin signaling. Because loss of caveolin-1 expression results in constitutive activation of eNOS activity, we also examined whether these increases in microvascular permeability are NO-dependent. Interestingly, treatment with l-NAME (a well established nitric-oxide synthase inhibitor) successfully reversed the microvascular hyperpermeability phenotype of Cav-1 knock-out mice. Thus, caveolin-1 plays a dual regulatory role in controlling microvascular permeability: (i) as a structural protein that is required for caveolae formation and caveolar transcytosis and (ii) as a tonic inhibitor of eNOS activity to negatively regulate the paracellular pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40091-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12167625-Animals, pubmed-meshheading:12167625-Capillaries, pubmed-meshheading:12167625-Capillary Permeability, pubmed-meshheading:12167625-Caveolin 1, pubmed-meshheading:12167625-Caveolins, pubmed-meshheading:12167625-Cell Membrane, pubmed-meshheading:12167625-Endothelium, Vascular, pubmed-meshheading:12167625-Enzyme Inhibitors, pubmed-meshheading:12167625-Integrins, pubmed-meshheading:12167625-Lung, pubmed-meshheading:12167625-Mice, pubmed-meshheading:12167625-Mice, Knockout, pubmed-meshheading:12167625-Microcirculation, pubmed-meshheading:12167625-Microscopy, Electron, pubmed-meshheading:12167625-NG-Nitroarginine Methyl Ester, pubmed-meshheading:12167625-Nitric Oxide Synthase, pubmed-meshheading:12167625-Nitric Oxide Synthase Type II, pubmed-meshheading:12167625-Nitric Oxide Synthase Type III, pubmed-meshheading:12167625-Protein Binding, pubmed-meshheading:12167625-Serum Albumin, pubmed-meshheading:12167625-Time Factors, pubmed-meshheading:12167625-Tissue Distribution
pubmed:year
2002
pubmed:articleTitle
Microvascular hyperpermeability in caveolin-1 (-/-) knock-out mice. Treatment with a specific nitric-oxide synthase inhibitor, L-NAME, restores normal microvascular permeability in Cav-1 null mice.
pubmed:affiliation
Department of Molecular Pharmacology, the Division of Hormone-Dependent Tumor Biology at the Albert Einstein Comprehensive Cancer Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't