Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2000-9-21
pubmed:abstractText
Reactive oxygen species (ROS) have been implicated as mediators of tumor necrosis factor-alpha (TNF) -induced apoptosis. In addition to leading to cell death, ROS can also promote cell growth and/or survival. We investigated these two roles of ROS in TNF-induced endothelial cell apoptosis. Human umbilical vein endothelial cells (HUVECs) stimulated with TNF produced an intracellular burst of ROS. Adenoviral-mediated gene transfer of a dominant negative form of the small GTPase Rac1 (Rac1N17) partially suppressed the TNF-induced oxidative burst without affecting TNF-induced mitochondrial ROS production. HUVECs were protected from TNF-induced apoptosis. Expression of Rac1N17 blocked TNF-induced activation of nuclear factor-kappa B (NF-kappaB), increased activity of caspase-3, and markedly augmented endothelial cell susceptibility to TNF-induced apoptosis. Direct inhibition of NF-kappaB through adenoviral expression of the super repressor form of inhibitor of kappaBalpha (I-kappaB S32/36A) also increased susceptibility of HUVECs to TNF-induced apoptosis. Rotenone, a mitochondrial electron transport chain inhibitor, suppressed TNF-induced mitochondrial ROS production, proteolytic cleavage of procaspase-3, and apoptosis. These findings show that Rac1 is an important regulator of TNF-induced ROS production in endothelial cells. Moreover, they suggest that Rac1-dependent ROS, directly or indirectly, lead to protection against TNF-induced death, whereas mitochondrial-derived ROS promote TNF-induced apoptosis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0892-6638
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1705-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Rac1 inhibits TNF-alpha-induced endothelial cell apoptosis: dual regulation by reactive oxygen species.
pubmed:affiliation
Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't