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:Aims/hypothesisInsulin resistance (IR) links obesity to type 2 diabetes. The aim of this study was to explore whether white adipose tissue (WAT) epigenetic dysregulation is associated with systemic IR by genome-wide CG dinucleotide (CpG) methylation and gene expression profiling in WAT from insulin-resistant and insulin-sensitive women. A secondary aim was to determine whether the DNA methylation signature in peripheral blood mononuclear cells (PBMCs) reflects WAT methylation and, if so, can be used as a marker for systemic IR.MethodsFrom 220 obese women, we selected a total of 80 individuals from either of the extreme ends of the distribution curve of HOMA-IR, an indirect measure of systemic insulin sensitivity. Genome-wide transcriptome and DNA CpG methylation profiling by array was performed on subcutaneous (SAT) and visceral (omental) adipose tissue (VAT). CpG methylation in PBMCs was assayed in the same cohort.ResultsThere were 647 differentially expressed genes (false discovery rate [FDR] 10%) in SAT, all of which displayed directionally consistent associations in VAT. This suggests that IR is associated with dysregulated expression of a common set of genes in SAT and VAT. The average degree of DNA methylation did not differ between the insulin-resistant and insulin-sensitive group in any of the analysed tissues/cells. There were 223 IR-associated genes in SAT containing a total of 336 nominally significant differentially methylated sites (DMS). The 223 IR-associated genes were over-represented in pathways related to integrin cell surface interactions and insulin signalling and included COL5A1, GAB1, IRS2, PFKFB3 and PTPRJ. In VAT there were a total of 51 differentially expressed genes (FDR 10%); 18 IR-associated genes contained a total of 29 DMS.Conclusions/interpretationIn individuals discordant for insulin sensitivity, the average DNA CpG methylation in SAT and VAT is similar, although specific genes, particularly in SAT, display significantly altered expression and DMS in IR, possibly indicating that epigenetic regulation of these genes influences metabolism.
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:BackgroundEpigenetics has been recognized as a significant regulator in many diseases. White adipose tissue (WAT) epigenetic dysregulation is associated with systemic insulin resistance (IR). The aim of this study was to survey the differential methylation of genes in obese women with systemic insulin resistance by DNA methylation microarray.MethodsThe genome-wide methylation profile of systemic insulin resistant obese women was obtained from Gene Expression Omnibus database. After data preprocessing, differing methylation patterns between insulin resistant and sensitive obese women were identified by Student's t-test and methylation value differences. Network analysis was then performed to reveal co-regulated genes of differentially methylated genes. Functional analysis was also implemented to reveal the underlying biological processes related to systemic insulin resistance in obese women.ResultsRelative to insulin sensitive obese women, we initially screened 10,874 differentially methylated CpGs, including 7402 hyper-methylated sites and 6073 hypo-methylated CpGs. Our analysis identified 4 significantly differentially methylated genes, including SMYD3, UST, BCL11A, and BAI3. Network and functional analyses found that these differentially methylated genes were mainly involved in chondroitin and dermatan sulfate biosynthetic processes.ConclusionBased on our study, we propose several epigenetic biomarkers that may be related to obesity-associated insulin resistance. Our results provide new insights into the epigenetic regulation of disease etiology and also identify novel targets for insulin resistance treatment in obese women.