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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-2-23
pubmed:abstractText
We previously reported that insulin activates nuclear factor kappaB (NF-kappaB) in Chinese hamster ovary (CHO)-R cells overexpressing wild-type insulin receptors (IRs) through a pathway requiring IR tyrosine kinase and Raf-1 kinase activities. We now investigated whether the activation of NF-kappaB by insulin could serve an antiapoptotic function. Insulin (10(-9)-10(-7) M) inhibited apoptosis induced by serum withdrawal in CHO-R cells in a concentration-dependent manner. Insulin antiapoptotic signaling: (i) was dependent on IR number and IR tyrosine kinase activity since it was reduced in parental CHO cells and was abolished in CHO-Y2 cells overexpressing IRs mutated at Tyr1162/1163; (ii) was, like insulin activation of NF-kappaB, dependent on Raf-1 but not on mitogen-activated protein kinase activity since both processes were decreased by the dominant-negative Raf-1 mutant Raf-C4 whereas they persisted in mitogen-activated protein kinase-depleted cells; and (iii) required NF-kappaB activation since it was decreased by proteasome inhibitors and the dominant-negative IkappaB-alpha (A32/36) mutant and was mimicked by overexpression of the NF-kappaB c-Rel subunit. We also show that insulin antiapoptotic signaling but not insulin activation of NF-kappaB involved phosphatidylinositol 3-kinase (PI 3-kinase), as supported by the inhibition of the former but not of the latter process by the PI 3-kinase inhibitor LY294002. Inhibition of both NF-kappaB and PI 3-kinase totally abolished insulin antiapoptotic signaling. Thus insulin exerts a specific antiapoptotic function which is dependent on IR tyrosine kinase activity and is mediated by both a Raf-1-dependent pathway that leads to NF-kappaB activation and a PI 3-kinase-dependent pathway.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2931-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
A role for nuclear factor kappaB in the antiapoptotic function of insulin.
pubmed:affiliation
INSERM U.402, Institut Fédératif de Recherche 65, Laboratoire de Biologie Cellulaire, Faculté de Médecine Saint-Antoine, 27 rue Chaligny, 75571 Paris, Cedex 12, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't