Linked Life Data

11526541

Source:http://linkedlifedata.com/resource/pubmed/id/11526541

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-8-29
pubmed:abstractText
Most of the morphologic changes that are observed in apoptotic cells are caused by a set of cysteine proteases (caspases) that are activated during this process. In previous works from our group we found that treatment of rat fetal hepatocytes with transforming growth factor beta1 (TGF-beta1) is followed by apoptotic cell death. TGF-beta1 mediates radical oxygen species (ROS) production that precedes bcl-xL down-regulation, loss of mitochondrial transmembrane potential, release of cytochrome c, and activation of caspase-3 (Herrera et al., FASEB J 2001;15:741-751). In this work, we have analyzed how TGF-beta1 activates the caspase cascade and whether or not caspase activation precedes the oxidative stress induced by this factor. Our results show that TGF-beta1 activates at least caspase-3, -8, and -9 in rat fetal hepatocytes, which are not required for ROS production, glutathione depletion, bcl-xL down-regulation, and initial cytochrome c release. However, caspase activation mediates cleavage of Bid and Bcl-xL that could originate an amplification loop on the mitochondrial events. An interesting result is that transmembrane potential disruption occurs later than the initial cytochrome c release and is mostly blocked by the pan-caspase inhibitor Z-VAD.fmk, indicating that the decrease in mitochondrial transmembrane potential (Delta(Psi)m) may be a consequence of caspase activity rather than the mechanism by which TGF-beta induces cytochrome c efflux. Finally, although Z-VAD.fmk completely blocks nucleosomal DNA fragmentation, it only delays cell death, which suggests that activation of the apoptotic program by TGF-beta in fetal hepatocytes inevitably leads to death, with or without caspases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0270-9139
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
548-56
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11526541-Animals, pubmed-meshheading:11526541-Apoptosis, pubmed-meshheading:11526541-Caspases, pubmed-meshheading:11526541-Cells, Cultured, pubmed-meshheading:11526541-Cytochrome c Group, pubmed-meshheading:11526541-Down-Regulation, pubmed-meshheading:11526541-Enzyme Activation, pubmed-meshheading:11526541-Fetus, pubmed-meshheading:11526541-Hepatocytes, pubmed-meshheading:11526541-Humans, pubmed-meshheading:11526541-Mitochondria, Liver, pubmed-meshheading:11526541-Proto-Oncogene Proteins c-bcl-2, pubmed-meshheading:11526541-Rats, pubmed-meshheading:11526541-Rats, Wistar, pubmed-meshheading:11526541-Reactive Oxygen Species, pubmed-meshheading:11526541-Recombinant Proteins, pubmed-meshheading:11526541-Time Factors, pubmed-meshheading:11526541-Transforming Growth Factor beta, pubmed-meshheading:11526541-bcl-X Protein
pubmed:year
2001
pubmed:articleTitle
Activation of caspases occurs downstream from radical oxygen species production, Bcl-xL down-regulation, and early cytochrome C release in apoptosis induced by transforming growth factor beta in rat fetal hepatocytes.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular, Instituto de Bioquímica, Centro Mixto CSIC/UCM, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't