Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR. DNA methylation was analyzed in DNA extracted from SAT (subcutaneous adipose tissue) and VAT (visceral adipose tissue) pieces, as well as PBMCs (peripheral blood mononuclear cells), using the Infinium Human Methylation 450 BeadChip assay. This data is from PBMCs.
Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR. DNA methylation was analyzed in DNA extracted from SAT (subcutaneous adipose tissue) and VAT (visceral adipose tissue) pieces, as well as PBMCs (peripheral blood mononuclear cells), using the Infinium Human Methylation 450 BeadChip assay. This data is from SAT.
Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR. DNA methylation was analyzed in DNA extracted from SAT (subcutaneous adipose tissue) and VAT (visceral adipose tissue) pieces, as well as PBMCs (peripheral blood mononuclear cells), using the Infinium Human Methylation 450 BeadChip assay. This data is from VAT (omental).
Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR.
Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR.
Project description:Impaired ability of insulin to stimulate cellular glucose uptake and regulate metabolism, that is insulin resistance (IR), links adiposity to metabolic disorders such as type 2 diabetes (T2D), dyslipidemia and cardiovascular disease (Langenberg, 2012). Both genetic and epigenetic factors are implicated in development of systemic IR (Vaag, 2001). IR is characterized by elevated levels of fasting insulin in the general circulation. The aim of this study is to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by global CpG methylation and gene expression profiling in subcutaneous and visceral adipose tissue. A secondary aim is to determine whether the DNA methylation signature in peripheral blood mononuclear cells reflect WAT methylation, and can be used as marker for systemic IR.
Project description:The association between central obesity and insulin resistance reflects the properties of visceral adipose tissue. Our aim was to gain further insight into this association by analysing the lipid composition of subcutaneous and omental adipose tissue in obese women with and without insulin resistance. Subcutaneous and omental adipose tissue and serum were obtained from 29 obese nondiabetic women, 13 of whom were hyperinsulinemic. Histology, and lipid and gene profiling were performed. In omental adipose tissue of obese, insulin-resistant women, adipocyte hypertrophy and macrophage infiltration were accompanied by an increase in GM3 ganglioside and its synthesis enzyme ST3GAL5; in addition, phosphatidylethanolamine (PE) lipids were increased and their degradation enzyme, PEMT, decreased. ST3GAL5 was expressed predominantly in adipose stromovascular cells and PEMT in adipocytes. Insulin resistance was also associated with an increase in PE lipids in serum. Total RNA was isolated and up to 400 ng of total RNA per sample was labelled and hybridized to Illumina HumanHT-12_V4 expression BeadChip platform. Paired subcutaneous and omental samples from 6 women were analysed.
Project description:The association between central obesity and insulin resistance reflects the properties of visceral adipose tissue. Our aim was to gain further insight into this association by analysing the lipid composition of subcutaneous and omental adipose tissue in obese women with and without insulin resistance. Subcutaneous and omental adipose tissue and serum were obtained from 29 obese nondiabetic women, 13 of whom were hyperinsulinemic. Histology, and lipid and gene profiling were performed. In omental adipose tissue of obese, insulin-resistant women, adipocyte hypertrophy and macrophage infiltration were accompanied by an increase in GM3 ganglioside and its synthesis enzyme ST3GAL5; in addition, phosphatidylethanolamine (PE) lipids were increased and their degradation enzyme, PEMT, decreased. ST3GAL5 was expressed predominantly in adipose stromovascular cells and PEMT in adipocytes. Insulin resistance was also associated with an increase in PE lipids in serum.
Project description:Background Obesity is associated with changes in fat cell gene expression and metabolism. What drives these changes is not well understood. We aimed to explore fat cell epigenetics, i.e., DNA methylation, as one mediator of gene regulation, in obese women. The global DNA methylome for abdominal subcutaneous fat cells was compared between 15 obese case (BMI 41.4 ± 4.4 kg/m 2 , mean ± SD) and 14 never-obese control women (BMI 25.2 ± 2.5 kg/m 2 ). Global array-based transcriptome analysis was analyzed for subcutaneous white adipose tissue (WAT) from 11 obese and 9 never-obese women. Limma was used for statistical analysis. Results We identified 5529 differentially methylated DNA sites (DMS) for 2223 differentially expressed genes between obese cases and never-obese controls (false discovery rate <5 %). The 5529 DMS displayed a median difference in beta value of 0.09 (range 0.01 to 0.40) between groups. DMS were under-represented in CpG islands and in promoter regions, and over-represented in open sea-regions and gene bodies. The 2223 differentially expressed genes with DMS were over-represented in key fat cell pathways: 31 of 130 (25 %) genes linked to “adipogenesis” (adjusted P = 1.66 × 10 −11 ), 31 of 163 (19 %) genes linked to “insulin signaling” (adjusted P = 1.91 × 10 −9 ), and 18 of 67 (27 %) of genes linked to “lipolysis” (P = 6.1 × 10 −5 ). In most cases, gene expression and DMS displayed reciprocal changes in obese women. Furthermore, among 99 candidate genes in genetic loci associated with body fat distribution in genome-wide association studies (GWAS); 22 genes displayed differential expression accompanied by DMS in obese versus never-obese women (P = 0.0002), supporting the notion that a significant proportion of gene loci linked to fat distribution are epigenetically regulated. Conclusions Subcutaneous WAT from obese women is characterized by congruent changes in DNA methylation and expression of genes linked to generation, distribution, and metabolic function of fat cells. These alterations may contribute to obesity-associated metabolic disturbances such as insulin resistance in women. The global DNA methylome in abdominal subcutaneous fat cells was compared between 15 obese cases (BMI 41.4±4.4 kg/m2, mean ± SD) and 14 never-obese control women (BMI 25.2±2.5 kg/m2).
Project description:The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin-resistant (OIR) or -sensitive (OIS) adipocytes. 432 genes were differentially expressed between the OIR and OIS group (FDR <5%). These genes are enriched in pathways related to glucose and amino acid metabolism, cellular respiration, and insulin signaling. Two IR-associated genes, KLF15 and SLC25A10, were selected for functional evaluation.