Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1994-3-4
pubmed:abstractText
Insulin resistance resulting from prolonged exposure of intact animals or cultured cells to glucocorticoids is often attributed to postreceptor signaling defects. To better understand the specific effects of glucocorticoids on insulin signaling, we have characterized the effect of dexamethasone on the expression of an insulin signaling intermediate, the insulin receptor substrate-1 (IRS-1) in 3T3-L1 adipocytes. Addition of dexamethasone resulted in a 40-70% decline in steady-state IRS-1 protein over 24-48 h of treatment. Dexamethasone did not significantly change the degradation rate of IRS-1 protein but decreased the net rate of amino acid incorporation into IRS-1 by 87%. Between 1 and 2.5 h of treatment with dexamethasone, actinomycin D, or both drugs given simultaneously, the concentration of IRS-1 mRNA declined with a half-life of 0.7-1.0 h. However, after 4 h of dexamethasone treatment, IRS-1 mRNA concentrations stabilized at approximately 35% of the control level. The dexamethasone-induced decline in IRS-1 protein could be prevented by simultaneous administration of the glucocorticoid antagonist mifepristone, RU38486. These results suggest that in 3T3-L1 adipocytes the loss of IRS-1 protein after dexamethasone treatment can be accounted for chiefly by inhibition of the synthesis of IRS-1 mRNA.
pubmed:grant
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
28
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2516-20
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8300578-3T3 Cells, pubmed-meshheading:8300578-Adipocytes, pubmed-meshheading:8300578-Amino Acid Sequence, pubmed-meshheading:8300578-Animals, pubmed-meshheading:8300578-Antibodies, pubmed-meshheading:8300578-Autoradiography, pubmed-meshheading:8300578-Dexamethasone, pubmed-meshheading:8300578-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:8300578-Immunoblotting, pubmed-meshheading:8300578-Insulin Receptor Substrate Proteins, pubmed-meshheading:8300578-Kinetics, pubmed-meshheading:8300578-Mice, pubmed-meshheading:8300578-Molecular Sequence Data, pubmed-meshheading:8300578-Peptides, pubmed-meshheading:8300578-Phosphoproteins, pubmed-meshheading:8300578-RNA, Messenger, pubmed-meshheading:8300578-Rabbits, pubmed-meshheading:8300578-Sulfur Radioisotopes, pubmed-meshheading:8300578-Time Factors, pubmed-meshheading:8300578-Transcription, Genetic
pubmed:year
1994
pubmed:articleTitle
Dexamethasone down-regulation of insulin receptor substrate-1 in 3T3-L1 adipocytes.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Texas Tech University Health Sciences Center, Lubbock 79430.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't