Linked Life Data

16462802

Source:http://linkedlifedata.com/resource/pubmed/id/16462802

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-2-7
pubmed:abstractText
The angiopoietins Ang-1 and Ang-2 have been identified as ligands of the receptor tyrosine kinase Tie-2 (refs. 1,2). Paracrine Ang-1-mediated activation of Tie-2 acts as a regulator of vessel maturation and vascular quiescence. In turn, the antagonistic ligand Ang-2 acts by an autocrine mechanism and is stored in endothelial Weibel-Palade bodies from where it can be rapidly released upon stimulation. The rapid release of Ang-2 implies functions of the angiopoietin-Tie system beyond its established role during vascular morphogenesis as a regulator of rapid vascular responses. Here we show that mice deficient in Ang-2 (encoded by the gene Angpt2) cannot elicit an inflammatory response in thioglycollate-induced or Staphylococcus aureus-induced peritonitis, or in the dorsal skinfold chamber model. Recombinant Ang-2 restores the inflammation defect in Angpt2(-/-) mice. Intravital microscopy showed normal TNF-alpha-induced leukocyte rolling in the vasculature of Angpt2(-/-)mice, but rolling cells did not firmly adhere to activated endothelium. Cellular experiments showed that Ang-2 promotes adhesion by sensitizing endothelial cells toward TNF-alpha and modulating TNF-alpha-induced expression of endothelial cell adhesion molecules. Together, these findings identify Ang-2 as an autocrine regulator of endothelial cell inflammatory responses. Ang-2 thereby acts as a switch of vascular responsiveness exerting a permissive role for the activities of proinflammatory cytokines.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1078-8956
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Angiopoietin-2 sensitizes endothelial cells to TNF-alpha and has a crucial role in the induction of inflammation.
pubmed:affiliation
Department of Vascular Biology and Angiogenesis Research, Tumor Biology Center, Freiburg 79106, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't