tetracycline has been researched along with Insulin-Resistance* in 4 studies
1 review(s) available for tetracycline and Insulin-Resistance
3 other study(ies) available for tetracycline and Insulin-Resistance
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Metabolic syndrome in mice induced by expressing a transcriptional activator in adipose tissue.
Metabolic syndrome is a combination of medical disorders that increases the risk of developing cardiovascular disease and diabetes. Constitutive overexpression of 11β-HSD1 in adipose tissue in mice leads to metabolic syndrome. In the process of generating transgenic mice overexpressing 11β-HSD1 in an inducible manner, we found a metabolic syndrome phenotype in control, transgenic mice, expressing the reverse tetracycline-transactivator (rtTA) in adipose tissue. The control mice exhibited all four sequelae of metabolic syndrome (visceral obesity, insulin resistance, dyslipidemia, and hypertension), a pro-inflammatory state and marked hepatic steatosis. Gene expression profiling of the adipose tissue, muscle and liver of these mice revealed changes in expression of genes involved in lipid metabolism, insulin resistance, and inflammation. Transient transfection of rtTA, but not tTS, into 3T3-L1 cells resulted in lipid accumulation. We conclude that expression of rtTA in adipose tissue causes metabolic syndrome in mice. Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; 3T3-L1 Cells; Adipose Tissue; Animals; Blood Pressure; Chromosomes, Mammalian; DNA Fragmentation; Fatty Liver; Gene Expression Profiling; Insulin Resistance; Lipid Metabolism; Male; Metabolic Syndrome; Mice; Mice, Transgenic; Muscles; Phenotype; Tetracycline; Trans-Activators; Transcriptional Activation; Transfection; Transgenes | 2012 |
A mouse model of conditional lipodystrophy.
Lipodystrophies are syndromes of adipose tissue degeneration associated with severe defects in lipid and glucose homeostasis. We report here the generation and analysis of Pparg(ldi), a targeted allele that confers conditional dominant lipodystrophy in mice. The Pparg(ldi) allele was generated by insertion of the Tet activator (tTA) and a tTA-regulated Flag-Pparg1 transgene into the Pparg gene. Unexpectedly, tTA elicits mild lipodystrophy, insulin resistance, and dyslipidemia, and the Flag-PPARgamma1 transgene surprisingly exacerbates these traits. Doxycycline can both completely prevent and reverse these phenotypes, providing a mouse model of inducible lipodystrophy. Embryonic fibroblasts from either Pparg(ldi/+) or the phenotypically similar aP2-nSrebp1c (Sr) transgenic mice undergo robust adipogenesis, suggesting that neither strain develops lipodystrophy because of defective adipocyte differentiation. In addition, Pparg(ldi/+) adipose tissue shares extensive gene expression aberrations with that of Sr mice, authenticating the phenotype at the molecular level and revealing a common expression signature of lipodystrophic fat. Thus, the Pparg(ldi/+) mouse provides a conditional animal model for studying lipodystrophy and its associated physiology and gene expression. Topics: Adipogenesis; Alleles; Animals; Disease Models, Animal; Doxycycline; Fibroblasts; Gene Expression; Insulin Resistance; Lipodystrophy; Mice; Mice, Transgenic; PPAR gamma; Promoter Regions, Genetic; Sterol Regulatory Element Binding Protein 1; Tetracycline; Trans-Activators | 2007 |
Insulin resistance in tetracycline-repressible Munc18c transgenic mice.
To investigate the physiological effects of modulating the abundance of Munc18c or syntaxin 4 (Syn4) proteins on the regulation of glucose homeostasis in vivo, we generated tetracycline-repressible transgenic mice that overexpress either Munc18c or Syn4 proteins in skeletal muscle, pancreas and adipose tissue seven-, five-, and threefold over endogenous protein, respectively. Munc18c transgenic mice displayed whole-body insulin resistance during hyperinsulinemic-euglycemic clamp resulting from >41% reductions in skeletal muscle and white adipose tissue glucose uptake, but without alteration of hepatic insulin action. Munc18c transgenic mice exhibited approximately 40% decreases in whole-body glycogen/lipid synthesis, skeletal muscle glycogen synthesis, and glycolysis. Glucose intolerance in Munc18c transgenic mice was reversed by repression of transgene expression using tetracycline or by simultaneous overexpression of Syn4 protein. In addition, Munc18c transgenic mice had depressed serum insulin levels, reflecting a threefold reduction in insulin secretion from islets isolated therefrom, thus uncovering roles for Munc18c and/or Syn4 in insulin granule exocytosis. Taken together, these results indicate that balance, more than absolute abundance, of Munc18c and Syn4 proteins directly affects whole-body glucose homeostasis through alterations in insulin secretion and insulin action. Topics: Adipose Tissue; Animals; Anti-Bacterial Agents; Gene Expression; Glucose; Glucose Intolerance; Homeostasis; Insulin; Insulin Resistance; Insulin Secretion; Membrane Proteins; Mice; Mice, Transgenic; Munc18 Proteins; Muscle, Skeletal; Nerve Tissue Proteins; Proteins; Qa-SNARE Proteins; Tetracycline; Vesicular Transport Proteins | 2003 |