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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2005-11-24
pubmed:abstractText
Insulin resistance is often associated with obesity. We tested whether augmentation of triglyceride synthesis in adipose tissue by transgenic overexpression of the diacylglycerol aclytransferase-1 (Dgat1) gene causes obesity and/or alters insulin sensitivity. Male FVB mice expressing the aP2-Dgat1 had threefold more Dgat1 mRNA and twofold greater DGAT activity levels in adipose tissue. After 30 weeks of age, these mice had hyperglycemia, hyperinsulinemia, and glucose intolerance on a high-fat diet but were not more obese than wild-type littermates. Compared with control littermates, Dgat1 transgenic mice were both insulin and leptin resistant and had markedly elevated plasma free fatty acid levels. Adipocytes from Dgat1 transgenic mice displayed increased basal and isoproterenol-stimulated lipolysis rates and decreased gene expression for fatty acid uptake. Muscle triglyceride content was unaffected, but liver mass and triglyceride content were increased by 20 and 300%, respectively. Hepatic insulin signaling was suppressed, as evidenced by decreased phosphorylation of insulin receptor-beta (Tyr(1,131)/Tyr(1,146)) and protein kinase B (Ser473). Gene expression data suggest that the gluconeogenic enzymes, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, were upregulated. Thus, adipose overexpression of Dgat1 gene in FVB mice leads to diet-inducible insulin resistance, which is secondary to redistribution of fat from adipose tissue to the liver in the absence of obesity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3379-86
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16306352-Adipose Tissue, pubmed-meshheading:16306352-Animals, pubmed-meshheading:16306352-Base Sequence, pubmed-meshheading:16306352-DNA Primers, pubmed-meshheading:16306352-Diacylglycerol O-Acyltransferase, pubmed-meshheading:16306352-Diet, pubmed-meshheading:16306352-Glucose Tolerance Test, pubmed-meshheading:16306352-Humans, pubmed-meshheading:16306352-Insulin Resistance, pubmed-meshheading:16306352-Lipolysis, pubmed-meshheading:16306352-Male, pubmed-meshheading:16306352-Mice, pubmed-meshheading:16306352-Mice, Inbred Strains, pubmed-meshheading:16306352-Mice, Transgenic, pubmed-meshheading:16306352-Obesity, pubmed-meshheading:16306352-Phosphorylation, pubmed-meshheading:16306352-Promoter Regions, Genetic, pubmed-meshheading:16306352-Proto-Oncogene Proteins c-akt, pubmed-meshheading:16306352-Receptor, Insulin
pubmed:year
2005
pubmed:articleTitle
Whole-body insulin resistance in the absence of obesity in FVB mice with overexpression of Dgat1 in adipose tissue.
pubmed:affiliation
Department of Medicine, Columbia University College of Physicians and Surgeons, 630 West 168th St., PH 10-305J, New York, New York 10032, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural