Project description:Development of insulin resistance is a key pathogenic component underlying metabolic syndrome and Type 2 diabetes (T2DM). Despite its importance, the molecular mechanisms underlying insulin resistance are poorly understood. Genome-wide association studies for T2DM and other metabolic traits have led to the identification of many candidate SNPs, but the majority of these SNPs are noncoding and determination of associated causal genes and/or specific tissue sites of action have been difficult. Adipocytes are critical regulators of mammalian metabolic homeostasis, with important effects on appetite, satiety, glucose and lipid homeostasis, energy expenditure, blood pressure, and immune function. Although insulin resistance (IR) in skeletal muscle, the major source of glucose disposal, is responsible for the bulk of the hyperglycemia observed in T2DM, muscle IR KO mice are generally healthy, IR also occurs in adipocytes, and inflammation within adipose tissue has been proposed as a primary mediator of IR, resulting in excess release of free fatty acids as well as alterations in adipokine release. Absence of adipose tissue, as observed in various lipodystrophies, or adipocyte-specific knockout of genes such as GLUT4 or insulin receptor, also alter systemic IR and T2DM risk. Transcriptional changes in adipocytes associated with metabolic disease. Despite the importance of adipocytes to metabolic disease, we have a poor understanding of how the adipocyte transcriptome changes in the disease state. Studies investigating transcriptional changes in whole adipose tissue have shown decreases in genes involved in adipogenesis, as well as alterations in inflammation, mitochondrial metabolism, lipid metabolism, detoxification, and insulin signaling. However, the vast majority of these studies use total adipose tissue samples, which does not allow for the exclusive evaluation of gene expression in mature adipocytes due to the substantial number of nonadipocyte cells (immune cells, fibroblasts, endothelial cells, pre-adipocytes, and mesenchymal cells) that also reside in adipose tissue. This is particularly relevant when studying metabolic disorders related to obesity-associated insulin resistance because these conditions are characterized by an increased influx of inflammatory cells into the adipose tissue.
Project description:Insulin resistance is a sine qua non of Type 2 diabetes (T2D) and a frequent complication of multiple clinical conditions, including obesity, aging, and steroid use, among others. How such a panoply of insults can result in a common phenotype is incompletely understood. Furthermore, very little is known about the transcriptional and epigenetic basis of this disorder, despite evidence that such pathways are likely to play a fundamental role. Here, we compare cell autonomous models of insulin resistance induced by the cytokine tumor necrosis factor-a (TNF) or by the steroid dexamethasone (Dex) to construct detailed epigenomic maps associated with cellular insulin resistance. Murine 3T3-L1 adipocytes were treated separately with dexamethasone (Dex; 20nM) or tumor necrosis factor-alpha. To comprehensively assess epigenomic changes caused by Dex and TNF in a time-dependent manner, we profiled cells at early (2 hours), intermediate (24 hours), and late (6 days) points in the development of insulin resistance.
Project description:Insulin resistance is a sine qua non of Type 2 diabetes (T2D) and a frequent complication of multiple clinical conditions, including obesity, aging, and steroid use, among others. How such a panoply of insults can result in a common phenotype is incompletely understood. Furthermore, very little is known about the transcriptional and epigenetic basis of this disorder, despite evidence that such pathways are likely to play a fundamental role. Here, we compare cell autonomous models of insulin resistance induced by the cytokine tumor necrosis factor-a (TNF) or by the steroid dexamethasone (Dex) to construct detailed transcriptional profiles associated with cellular insulin resistance. Gene expression data from mouse adipocyte, with TNF or Dex treatments at different time points. Murine 3T3-L1 adipocytes were treated separately with dexamethasone (Dex; 20nM) or tumor necrosis factor-alpha. To comprehensively assess gene expression changes caused by Dex and TNF in a time-dependent manner, we profiled cells at early (2 hours), intermediate (24 hours), and late (6 days) points in the development of insulin resistance.
Project description:Insulin resistance is a sine qua non of Type 2 diabetes (T2D) and a frequent complication of multiple clinical conditions, including obesity, aging, and steroid use, among others. How such a panoply of insults can result in a common phenotype is incompletely understood. Furthermore, very little is known about the transcriptional and epigenetic basis of this disorder, despite evidence that such pathways are likely to play a fundamental role. Here, we compare cell autonomous models of insulin resistance induced by the cytokine tumor necrosis factor-a (TNF) or by the steroid dexamethasone (Dex) to construct detailed transcriptional profiles associated with cellular insulin resistance. Gene expression data from mouse adipocyte, with TNF or Dex treatments at different time points.
Project description:Insulin resistance is a sine qua non of Type 2 diabetes (T2D) and a frequent complication of multiple clinical conditions, including obesity, aging, and steroid use, among others. How such a panoply of insults can result in a common phenotype is incompletely understood. Furthermore, very little is known about the transcriptional and epigenetic basis of this disorder, despite evidence that such pathways are likely to play a fundamental role. Here, we compare cell autonomous models of insulin resistance induced by the cytokine tumor necrosis factor-a (TNF) or by the steroid dexamethasone (Dex) to construct detailed epigenomic maps associated with cellular insulin resistance.
Project description:Postoperative insulin resistance refers to the phenomenon that the body’s glucose uptake stimulated by insulin is reduced due to stress effects such as trauma or the inhibitory effect of insulin on liver glucose output is weakened after surgery.
There is a clear link between postoperative insulin resistance and poor perioperative prognosis. Therefore, exploring interventions to reduce postoperative stress insulin resistance, stabilize postoperative blood glucose, and reduce postoperative complications are clinical problems that need to be solved urgently. In recent years, research on branched-chain amino acids and metabolic diseases has become a hot spot. Studies have found that in the rat model, preoperatively given a high branched-chain amino acid diet can inhibit postoperative insulin resistance and stabilize blood glucose levels. This research plan is to try to add branched-chain amino acids before surgery to observe the occurrence of postoperative insulin resistance in patients.
Project description:We aim to identify a novel pathway to regulate insulin resistance from transcriptional profiles of skeletal muscles from patients with diabetes and to demonstrate its role in experimental models of insulin resistance. We performed transcriptional profiling of skeletal muscles from subjects with or without diabetes. Through an integrative analysis of our dataset with four previous datasets, we identified the core gene sets associated with insulin resistance.
Project description:Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARγ ligands. We transcriptionally profiled 364 biopsies gathered from 72 human subjects harvested before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Subjects range from insulin-sensitive to insulin-resistant. Insulin resistant subjects responded to TZD treatment with varied improvements in insulin sensitivity, thus they were ranked by their degree of TZD response to define responder and non-responder subgroups.
Project description:Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPAR? ligands. We transcriptionally profiled 364 biopsies gathered from 72 human subjects harvested before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Subjects range from insulin-sensitive to insulin-resistant. Insulin resistant subjects responded to TZD treatment with varied improvements in insulin sensitivity, thus they were ranked by their degree of TZD response to define responder and non-responder subgroups. Skeletal muscle biopsies were obtained from vastus lateralis before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Adipose tissue biopsies were obtained from abdominal subcutaneous before clamp, at baseline and after three-month TZD treatment. *** CEL files not provided for 40 Samples. ***
Project description:Diet-induced obesity (DIO) predisposes individuals to insulin resistance, and adipose tissue has a major role in the disease. Insulin resistance can be induced in cultured adipocytes by a variety of treatments, but what aspects of the in vivo responses are captured by these models remains unknown. We use global RNA sequencing to investigate changes induced by TNF-a, hypoxia, dexamethasone, high insulin, and a combination of TNF-a and hypoxia, comparing the results to the changes in white adipose tissue from DIO mice. We found that different in vitro models capture distinct features of DIO adipose insulin resistance, and a combined treatment of TNF-a and hypoxia is most able to mimic the in vivo changes. Using genome-wide DNase I hypersensitivity followed by sequencing, we further examined the transcriptional regulation of TNF-a-induced insulin resistance, and we found that C/EPBM-CM-^_ key regulator of adipose insulin resistance. RNA-seq for 6 insulin resistance conditions and 2 control conditions, Dnase hypersensitivity-seq of 4 conditions and 1 control condition, ChIP-seq on p65 after TNFa treatment.