Project description:Deficiency of fatty acid translocase Cd36 has been shown to play major role in pathogenesis of metabolic syndrome components in the spontaneously hypertensive rat (SHR). We have tested the hypothesis that effects of Cd36 mutation on features of metabolic syndrome are contextually-dependent on genomic background. We have derived two new congenic strains by introgression of limited chromosome 4 regions of SHR origin, both including defective Cd36 gene, into genetic background of highly inbred model of insulin resistance and dyslipidemia, polydactylous (PD) rat strain. We have subjected standard diet-fed adult males of PD and the 2 congenic PD.SHR4 strains to metabolic, morphometric and transcriptomic (Affymetrix Rat 1.0 ST Exon array) profiling. We observed significantly improved glucose tolerance and lower fasting insulin in PD.SHR4 congenics than in PD. One of the PD.SHR4 strains also showed lower triglyceride concentrations across major lipoprotein fractions combined with higher concentrations of LDL cholesterol compared to PD progenitor. The other PD.SHR4 strain had lower total and HDL cholesterol as well as lower LDL and HDL triacylglycerol content compared to PD. The hepatic transcriptome assessment revealed network of genes differentially expressed between PD and PD.SHR4 with significant enrichment by members of circadian rhythmicity pathway (Arntl (Bmal1), Clock, Nfil3, Per2 and Per3). In summary, the introduction of chromosome .4 region of SHR origin including defective Cd36 into PD genetic background resulted in disconnected shifts of metabolic profile along with distinct changes in hepatic transcriptome. The synthesis of the current results with those obtained in other Cd36-deficient strains indicate that the eventual metabolic effect of deleterious mutation such as that of SHR-derived Cd36 is not absolute, but rather a function of complex interactions between environment and genomic background, upon which it operates.
Project description:Deficiency of fatty acid translocase Cd36 has been shown to play major role in pathogenesis of metabolic syndrome components in the spontaneously hypertensive rat (SHR). We have tested the hypothesis that effects of Cd36 mutation on features of metabolic syndrome are contextually-dependent on genomic background. We have derived two new congenic strains by introgression of limited chromosome 4 regions of SHR origin, both including defective Cd36 gene, into genetic background of highly inbred model of insulin resistance and dyslipidemia, polydactylous (PD) rat strain. We have subjected standard diet-fed adult males of PD and the 2 congenic PD.SHR4 strains to metabolic, morphometric and transcriptomic (Affymetrix Rat 1.0 ST Exon array) profiling. We observed significantly improved glucose tolerance and lower fasting insulin in PD.SHR4 congenics than in PD. One of the PD.SHR4 strains also showed lower triglyceride concentrations across major lipoprotein fractions combined with higher concentrations of LDL cholesterol compared to PD progenitor. The other PD.SHR4 strain had lower total and HDL cholesterol as well as lower LDL and HDL triacylglycerol content compared to PD. The hepatic transcriptome assessment revealed network of genes differentially expressed between PD and PD.SHR4 with significant enrichment by members of circadian rhythmicity pathway (Arntl (Bmal1), Clock, Nfil3, Per2 and Per3). In summary, the introduction of chromosome .4 region of SHR origin including defective Cd36 into PD genetic background resulted in disconnected shifts of metabolic profile along with distinct changes in hepatic transcriptome. The synthesis of the current results with those obtained in other Cd36-deficient strains indicate that the eventual metabolic effect of deleterious mutation such as that of SHR-derived Cd36 is not absolute, but rather a function of complex interactions between environment and genomic background, upon which it operates. Affymetrix GeneChip® Rat Exon 1.0 ST Array was used to determine the transcriptomic characteristics of the PD.SHR4a and the progenitor PD strain. We extracted total RNA from the liver of 4-month-old males of both strains (n=8/per strain) using phenol-chloroform and purified with the RNeasy Mini kit (Qiagen) in accordance with the manufacturer’s protocol. The quality of the total RNA was verified by the Agilent 2100 Bioanalyzer system. Double-stranded complementary DNA (cDNA) was synthesized from total RNA. The labeled and fragmented cDNA was pooled for each strain and hybridized to Affymetrix GeneChip® Rat Exon 1.0 ST Arrays (PD.SHR4a - 2 chips; PD - 3 chips). The whole hybridization procedure including DNA adjustment was performed according to the protocol recommended by Affymetrix.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia. This SuperSeries is composed of the following subset Series:; GSE13582: Expression data from BAT of the KRAP deficient mice; GSE13583: Expression data from liver of the KRAP deficient mice Experiment Overall Design: Refer to individual Series
Project description:Bezafibrate (BEZ), a pan activator of peroxisome proliferator-activated receptors (PPARs), is generally used to treat hyperlipidemia. Clinical trials on patients suffering from type 2 diabetes indicated that BEZ also has beneficial effects on glucose metabolism, but the underlying mechanisms remain elusive. Much less is known about the function of BEZ in type 1 diabetes. Here, we show that BEZ treatment markedly improves hyperglycemia, glucose and insulin tolerance in streptozotocin (STZ)-treated mice, an insulin-deficient mouse model of type 1 diabetes presenting with very high blood glucose levels. Furthermore, BEZ-treated mice also exhibited improved metabolic flexibility as well as an enhanced mitochondrial mass and function in the liver. Our data demonstrate a beneficial effect of BEZ treatment on STZ mice reducing diabetes and suggest that BEZ ameliorates impaired glucose metabolism possibly via augmented hepatic mitochondrial performance, improved insulin sensitivity and metabolic flexibility. We performed gene expression microarray analysis on liver tissue derived from streptozotocin-treated mice treated with bezafibrate in addition.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia. Experiment Overall Design: Total RNA was extracted from BAT of three pairs of littermates (KO1 vs. WT1, KO2 vs. WT2 and KO3 vs. WT3) fed normal chow.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia. Experiment Overall Design: Total RNA was extracted from livers of three pairs of littermates (KO1 vs. WT1, KO2 vs. WT2 and KO3 vs. WT3) fed normal chow.
Project description:KRAP (Ki-ras-induced actin-interacting protein) is a cytoskeleton-associated protein and a ubiquitous protein among tissues, originally identified as a cancer-related molecule. KRAP-deficient (KRAP-/-) mice show enhanced metabolic rate, decreased adiposity, improved glucose tolerance, hypoinsulinemia and hypoleptinemia. KRAP-/- mice are also protected against high-fat diet-induced obesity and insulin resistance despite of hyperphagia. This SuperSeries is composed of the SubSeries listed below.
Project description:Bezafibrate (BEZ), a pan activator of peroxisome proliferator-activated receptors (PPARs), is generally used to treat hyperlipidemia. Clinical trials on patients suffering from type 2 diabetes indicated that BEZ also has beneficial effects on glucose metabolism, but the underlying mechanisms remain elusive. Much less is known about the function of BEZ in type 1 diabetes. Here, we show that BEZ treatment markedly improves hyperglycemia, glucose and insulin tolerance in streptozotocin (STZ)-treated mice, an insulin-deficient mouse model of type 1 diabetes presenting with very high blood glucose levels. Furthermore, BEZ-treated mice also exhibited improved metabolic flexibility as well as an enhanced mitochondrial mass and function in the liver. Our data demonstrate a beneficial effect of BEZ treatment on STZ mice reducing diabetes and suggest that BEZ ameliorates impaired glucose metabolism possibly via augmented hepatic mitochondrial performance, improved insulin sensitivity and metabolic flexibility.