Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2005-3-21
pubmed:abstractText
The passage of leukocytes out of the blood circulation and into tissues is necessary for the normal inflammatory response, but it also occurs inappropriately in many pathological situations. This process is limited by the barrier presented by the junctions between adjacent endothelial cells that line blood vessels. Here we show that activation of the Rap1 GTPase in endothelial cells accelerated de novo assembly of endothelial cell-cell junctions and increased the barrier function of endothelial monolayers. In contrast, depressing Rap1 activity by expressing Rap1GAP led to disassembly of these junctions and increased their permeability. We also demonstrate that endogenous Rap1 was rapidly activated at early stages of junctional assembly, confirming the involvement of Rap1 during junctional assembly. Intriguingly, elevating Rap1 activity selectively within endothelial cells decreased leukocyte transendothelial migration, whereas inhibiting Rap1 activity by expression of Rap1GAP increased leukocyte transendothelial migration, providing physiological relevance to our hypothesis that Rap1 augments barrier function of inter-endothelial cell junctions. Furthermore, these results suggest that Rap1 may be a novel therapeutic target for clinical conditions in which an inappropriate inflammatory response leads to disease.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11675-82
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Rap1 GTPase inhibits leukocyte transmigration by promoting endothelial barrier function.
pubmed:affiliation
Department of Cell and Developmental Biology and Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7295, USA. erika_witchen@med.unc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't