E-GEOD-62013
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: PRJNA262937
DISEASE(S): Streptozotocin-induced Diabetes,None
PROVIDER: E-GEOD-62013 | ExpressionAtlas | 2014-10-28
REPOSITORIES: ExpressionAtlas
Similar Datasets
Project description:Diabetes and Insulin in Regulation of Brain Cholesterol Metabolism
| PRJNA262937 | ENA
Project description:The brain is the most cholesterol-rich organ in the body, most of which comes from in situ synthesis. Here we demonstrate that in insulin-deficient diabetic mice, there is a reduction in expression of the major transcriptional regulator of cholesterol metabolism, SREBP-2, and its downstream genes in the hypothalamus and other areas of the brain, leading to a reduction in brain cholesterol synthesis and synaptosomal cholesterol content. These changes are due, at least in part, to direct effects of insulin to regulate these genes in neurons and glial cells and can be corrected by intracerebroventricular injections of insulin. Knockdown of SREBP-2 in cultured neurons causes a decrease in markers of synapse formation and reduction of SREBP-2 in the hypothalamus of mice using shRNA results in increased feeding and weight gain. Thus, insulin and diabetes can alter brain cholesterol metabolism, and this may play an important role in the neurologic and metabolic dysfunction observed in diabetes and other disease states. Hypothalamus was compared between streptozotocin (STZ)-induced diabetic, ob/ob, and control mice, with 5-6 replicates per goup.
2014-10-03 | E-GEOD-62013 | biostudies-arrayexpress
Project description:The brain is the most cholesterol-rich organ in the body, most of which comes from in situ synthesis. Here we demonstrate that in insulin-deficient diabetic mice, there is a reduction in expression of the major transcriptional regulator of cholesterol metabolism, SREBP-2, and its downstream genes in the hypothalamus and other areas of the brain, leading to a reduction in brain cholesterol synthesis and synaptosomal cholesterol content. These changes are due, at least in part, to direct effects of insulin to regulate these genes in neurons and glial cells and can be corrected by intracerebroventricular injections of insulin. Knockdown of SREBP-2 in cultured neurons causes a decrease in markers of synapse formation and reduction of SREBP-2 in the hypothalamus of mice using shRNA results in increased feeding and weight gain. Thus, insulin and diabetes can alter brain cholesterol metabolism, and this may play an important role in the neurologic and metabolic dysfunction observed in diabetes and other disease states.
2014-10-03 | GSE62013 | GEO
Project description:The global prevalence of type 2 diabetes (T2D) is increasing, and it is contributing to the susceptibility to diabetes and its related epidemic in offspring. Although the impacts of paternal T2D on metabolism of offspring have been well established, the exact molecular and mechanistic basis that mediates these impacts remains largely unclear. Here we show that paternal T2D increases the susceptibility to diabetes in offspring through the gametic epigenetic alterations. Paternal T2D led to glucose intolerance and insulin resistance in offspring. Relative to controls, offspring of T2D fathers exhibited altered gene expression patterns in the pancreatic islets, with downregulation of several genes involved in glucose metabolism and insulin signaling pathway. Epigenomic profiling of offspring pancreatic islets revealed numerous changes in cytosine methylation depending on paternal T2D, including reproducible changes in methylation over several insulin signaling genes. Paternal T2D altered overall methylome patterns in sperm, with a large portion of differentially methylated genes overlapped with that of pancreatic islets in offspring. Our study revealed, for the first time, that T2D can be inherited transgenerationally through the mammalian germline by an epigenetic manner. Examination of the effect of paternal T2D on the DNA methylation in the pancreatic islets of offspring and in the sperm of father.
2013-01-02 | E-GEOD-43238 | biostudies-arrayexpress
Project description:Type 2 diabetes is a complex disease associated with many underlying pathomechanisms. Epigenetic regulation of gene expression by DNA methylation has become increasingly recognized as an important component in the etiology of type 2 diabetes. We performed genome-wide methylome and transcriptome analysis in liver from severely obese patients with or without type 2 diabetes to discover aberrant pathways underlying the development of insulin resistance. We identified hypomethylation of five key genes involved in hepatic glycolysis, de novo lipogenesis and insulin resistance with concomitant increased mRNA expression and protein content. The CpG-site within the ATF-motif was hypomethylated in four of these genes in liver of non-diabetic and type 2 diabetic obese patients, suggesting epigenetic regulation of transcription by altered ATF-DNA binding. In conclusion, severely obese non-diabetic and type 2 diabetic patients have distinct alterations in the hepatic methylome and transcriptome and genes controlling glucose and lipid metabolism are hypomethylated at a regulatory site. Thus, obesity may epigenetically reprogram the liver towards increased lipid production and exacerbate the development of insulin resistance. To better understand the molecular mechanisms underlying the development of hepatic insulin resistance and type 2 diabetes at a molecular level, we performed a genome-wide methylome and transcriptome analysis of liver from non-obese metabolically healthy, obese non-diabetic and obese type 2 diabetic patients. Distinct DNA methylation and gene expression profiles were identified in liver from the obese and type 2 diabetic patients compared with the non-obese participants.
2016-03-08 | E-GEOD-64998 | biostudies-arrayexpress
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.
2016-06-29 | E-GEOD-79008 | biostudies-arrayexpress
Project description:TCF7L2 is one of the strongest type 2 diabetes (T2DM) candidate genes to emerge from GWAS studies, but the mechanisms by which it regulates the pathways which are important in the pathogenesis of type 2 diabetes are unknown. Previous in vitro and in vivo studies have focused on the link between TCF7L2 and insulin secretion as an explanation for the association between TCF7L2 and T2DM. However, TCF7L2 and the Wnt/β-catenin pathway are important for metabolic zonation in the liver. This raises the interesting possibility that TCF7L2 may influence glucose homeostasis by regulating hepatic glucose production (HGP). To examine this question, we utilized the H4IIE cell as a model of HGP. Inhibition of HGP in H4IIE cells from lactate and pyruvate was highly sensitive to physiological concentrations of insulin and metformin. Silencing of TCF7L2 protein expression induced a 5-fold increase in basal HGP (P<0.0001), and this was accompanied by marked increase in the expression of several key gluconeogenic genes. FBPase, PEPCK and G6Pase mRNA were up-regulated 2.5-fold (P<0.0001), 1.4-fold (P<0.01) and 2.3-fold (P<0.0001), respectively, compared to scramble siRNA. Compared to their respective baseline values, insulin and metformin suppressed HGP equally in the scramble and TCF7L2 siRNA cells, but HGP remained elevated in TCF7L2 silenced cells due to the increased baseline HGP. Using chromatin immunoprecipitation sequencing (ChIP-Seq), we investigated the direct transcriptional targets of TCF7L2 in hepatocytes. A total of 2119 ChIP peaks were detected, of which 36% were located inside gene boundaries and, overall, a total of 65% of all binding events were within 50 Kb of a gene. De novo motif analysis revealed remarkable conservation of the long and short TCF7L2 consensus binding sites in the rat hepatocytes. Pathway analysis showed that the top two disease categories over-represented in our dataset were “non-insulin dependent diabetes” (155 genes; P = 1.63 x 10-10) and “diabetes mellitus” (245 genes; P = 7.4 x 10-12). Inspection of genes in these categories revealed that TCF7L2 directly binds to multiple genes important in the regulation of glucose metabolism in the liver, including PEPCK, FBP1, IRS1, IRS2, AKT2 ADIPOR1, PDK4 and CPT1A. Our findings suggest a novel mechanism for the regulation of HGP by TCF7L2, and provide a possible explanation for the association of TCF7L2 polymorphisms with the incidence of T2DM. two samples: TCF7L2 ChIP-Seq and Input DNA
2011-09-12 | E-GEOD-28782 | biostudies-arrayexpress
Project description:The liver plays a central role in whole-body lipid and glucose homeostasis. Increasing dietary fat intake results in increased hepatic fat deposition, which is associated with a risk for development of insulin resistance and type 2 diabetes. In this study, we demonstrate a role for the phosphate inorganic transporter 1 (PiT1/SLC20A1) in regulating metabolism. Specific knockout of Pit1 in hepatocytes significantly improved glucose tolerance and insulin sensitivity, enhanced insulin signalling, and decreased hepatic lipogenesis. We identified USP7 as a PiT1 binding partner and demonstrated that Pit1 deletion inhibited USP7/IRS1 dissociation upon insulin stimulation. This prevented IRS1 ubiquitination and its subsequent proteasomal degradation. As a consequence delayed insulin negative feedback loop and sustained insulin signalling were observed. Moreover, PiT1-deficient mice were protected against high fat diet-induced obesity and diabetes. Our findings indicate that PiT1 has potential as a therapeutic target in the context of metabolic syndrome, obesity, and diabetes.
2016-08-25 | E-MTAB-4989 | biostudies-arrayexpress
Project description:Type 2 diabetes is a complex disease associated with many underlying pathomechanisms. Epigenetic regulation of gene expression by DNA methylation has become increasingly recognized as an important component in the etiology of type 2 diabetes. We performed genome-wide methylome and transcriptome analysis in liver from severely obese patients with or without type 2 diabetes to discover aberrant pathways underlying the development of insulin resistance. We identified hypomethylation of five key genes involved in hepatic glycolysis, de novo lipogenesis and insulin resistance with concomitant increased mRNA expression and protein content. The CpG-site within the ATF-motif was hypomethylated in four of these genes in liver of non-diabetic and type 2 diabetic obese patients, suggesting epigenetic regulation of transcription by altered ATF-DNA binding. In conclusion, severely obese non-diabetic and type 2 diabetic patients have distinct alterations in the hepatic methylome and transcriptome and genes controlling glucose and lipid metabolism are hypomethylated at a regulatory site. Thus, obesity may epigenetically reprogram the liver towards increased lipid production and exacerbate the development of insulin resistance.
2016-03-08 | GSE65057 | GEO
Project description:Type 2 diabetes is a complex disease associated with many underlying pathomechanisms. Epigenetic regulation of gene expression by DNA methylation has become increasingly recognized as an important component in the etiology of type 2 diabetes. We performed genome-wide methylome and transcriptome analysis in liver from severely obese patients with or without type 2 diabetes to discover aberrant pathways underlying the development of insulin resistance. We identified hypomethylation of five key genes involved in hepatic glycolysis, de novo lipogenesis and insulin resistance with concomitant increased mRNA expression and protein content. The CpG-site within the ATF-motif was hypomethylated in four of these genes in liver of non-diabetic and type 2 diabetic obese patients, suggesting epigenetic regulation of transcription by altered ATF-DNA binding. In conclusion, severely obese non-diabetic and type 2 diabetic patients have distinct alterations in the hepatic methylome and transcriptome and genes controlling glucose and lipid metabolism are hypomethylated at a regulatory site. Thus, obesity may epigenetically reprogram the liver towards increased lipid production and exacerbate the development of insulin resistance.
2016-03-08 | GSE64998 | GEO