Expression data from human liver with or without type 2 diabetes
Ontology highlight
ABSTRACT: The liver may regulate glucose homeostasis by modulating the sensitivity/resistance of peripheral tissues to insulin, by way of the production of secreted proteins, termed hepatokines. To identify hepatic secretory proteins involved in insulin resistance, we performed liver biopsies in humans with or without type 2 diabetes and conducted a comprehensive analysis of gene expression profiles. Samples for analysis were obtained from ten patients with type 2 diabetes and 7 subjects with normal glucose tolerance, who were admitted to Kanazawa University Hospital. Hepatic tissues were obtained with percutaneous needle liver biopsy, and immediately frozen in liquid nitrogen and stored at −80°C until use. This dataset is part of the TransQST collection.
Project description:Insulin integrates hepatic glucose and lipid metabolism, directing nutrients to storage as glycogen and triglyceride. In type 2 diabetes, levels of the former are low and the latter are exaggerated, posing a pathophysiologic and therapeutic conundrum. A branching model1 of insulin signaling, with FoxO1 presiding over glucose production2-5 and Srebp–1c regulating lipogenesis,6-8 provides a potential explanation. Here we illustrate an alternative mechanism that integrates glucose production and lipogenesis under the unifying control of FoxO. Liver–specific ablation of three FoxOs (L–FoxO1,3,4) prevents the induction of glucose–6–phosphatase and the repression of glucokinase during fasting, thus increasing lipogenesis at the expense of glucose production. We document a similar pattern in the early phases of diet-induced insulin resistance, and propose that FoxOs are required to enable the liver to direct nutritionally derived carbons to glucose vs. lipid metabolism. Our data underscore the heterogeneity of hepatic insulin resistance during progression from the metabolic syndrome to overt diabetes, and the conceptual challenge of designing therapies that curtail glucose production without promoting hepatic lipid accumulation. We used microarrays to detail the change of gene expression in liver after knocking out FoxO1,3 and 4. Liver tissue samples were collected from hepatocyte- specific triple FoxO(1,3, and 4) KO and their littermates control (WT) mice after fasting (22 h) or refeeding (4 h). Gene expression was analyzed by microarray. Mice were on a mixed background of C57BL/6J and 129.
Project description:Insulin integrates hepatic glucose and lipid metabolism, directing nutrients to storage as glycogen and triglyceride. In type 2 diabetes, levels of the former are low and the latter are exaggerated, posing a pathophysiologic and therapeutic conundrum. A branching model1 of insulin signaling, with FoxO1 presiding over glucose production2-5 and Srebp–1c regulating lipogenesis,6-8 provides a potential explanation. Here we illustrate an alternative mechanism that integrates glucose production and lipogenesis under the unifying control of FoxO. Liver–specific ablation of three FoxOs (L–FoxO1,3,4) prevents the induction of glucose–6–phosphatase and the repression of glucokinase during fasting, thus increasing lipogenesis at the expense of glucose production. We document a similar pattern in the early phases of diet-induced insulin resistance, and propose that FoxOs are required to enable the liver to direct nutritionally derived carbons to glucose vs. lipid metabolism. Our data underscore the heterogeneity of hepatic insulin resistance during progression from the metabolic syndrome to overt diabetes, and the conceptual challenge of designing therapies that curtail glucose production without promoting hepatic lipid accumulation. We used microarrays to detail the change of gene expression in liver after knocking out FoxO1,3 and 4.
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:Obesity-related insulin resistance represents the core component of the so-called Metabolic Syndrome, ultimately promoting glucose intolerance, pancreatic beta cell failure, and overt type 2 diabetes 1 2. Based on substantial side effects of existing pharmacological approaches, efficient and safe insulin sensitization and glucose control remain critical therapeutic aims to prevent diabetic late complications. Here, we identify Transforming Growth Factor beta-like Stimulated Clone (TSC) 22 D4 as a critical molecular determinant of insulin signaling and glucose handling. Hepatocyte-specific inactivation of TSC22D4 enhanced insulin signaling in liver and skeletal muscle, while hepatic TSC22D4 overexpression blunted insulin tissue responses. Consequently, hepatic TSC22D4 inhibition both prevented and reversed hyperglycemia, glucose intolerance, and insulin resistance in various diabetes mouse models, respectively. TSC22D4 was found to exert its effects on systemic glucose homeostasis –in large parts- through the transcriptional regulation of the small secretory protein lipocalin (LCN) 13 as demonstrated by chromatin recruitment and genetic rescue experiments in vivo. As hepatic TSC22D4 levels were found to be elevated in human diabetic patients, correlating with decreased insulin sensitivity and hyperglycemia, our results establish the inhibition of TSC22D4 as an attractive insulin sensitizing option in diabetes therapy.
Project description:Obesity-related insulin resistance represents the core component of the so-called Metabolic Syndrome, ultimately promoting glucose intolerance, pancreatic beta cell failure, and overt type 2 diabetes 1 2. Based on substantial side effects of existing pharmacological approaches, efficient and safe insulin sensitization and glucose control remain critical therapeutic aims to prevent diabetic late complications 3. Here, we identify Transforming Growth Factor beta-like Stimulated Clone (TSC) 22 D4 as a critical molecular determinant of insulin signaling and glucose handling. Hepatocyte-specific inactivation of TSC22D4 enhanced insulin signaling in liver and skeletal muscle, while hepatic TSC22D4 overexpression blunted insulin tissue responses. Consequently, hepatic TSC22D4 inhibition both prevented and reversed hyperglycemia, glucose intolerance, and insulin resistance in various diabetes mouse models, respectively. TSC22D4 was found to exert its effects on systemic glucose homeostasis - in large parts - through the transcriptional regulation of the small secretory protein lipocalin (LCN) 13 as demonstrated by chromatin recruitment and genetic rescue experiments in vivo. As hepatic TSC22D4 levels were found to be elevated in human diabetic patients, correlating with decreased insulin sensitivity and hyperglycemia, our results establish the inhibition of TSC22D4 as an attractive insulin sensitizing option in diabetes therapy.
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.
Project description:Obesity-related insulin resistance represents the core component of the so-called Metabolic Syndrome, ultimately promoting glucose intolerance, pancreatic beta cell failure, and overt type 2 diabetes 1 2. Based on substantial side effects of existing pharmacological approaches, efficient and safe insulin sensitization and glucose control remain critical therapeutic aims to prevent diabetic late complications 3. Here, we identify Transforming Growth Factor beta-like Stimulated Clone (TSC) 22 D4 as a critical molecular determinant of insulin signaling and glucose handling. Hepatocyte-specific inactivation of TSC22D4 enhanced insulin signaling in liver and skeletal muscle, while hepatic TSC22D4 overexpression blunted insulin tissue responses. Consequently, hepatic TSC22D4 inhibition both prevented and reversed hyperglycemia, glucose intolerance, and insulin resistance in various diabetes mouse models, respectively. TSC22D4 was found to exert its effects on systemic glucose homeostasis - in large parts - through the transcriptional regulation of the small secretory protein lipocalin (LCN) 13 as demonstrated by chromatin recruitment and genetic rescue experiments in vivo. As hepatic TSC22D4 levels were found to be elevated in human diabetic patients, correlating with decreased insulin sensitivity and hyperglycemia, our results establish the inhibition of TSC22D4 as an attractive insulin sensitizing option in diabetes therapy. 28 BKS.Cg-Dock7m +/+ Leprdb/J (000642) mice (12 week old ) were divided to 4 forms of treatment (n=7 per treatment group) consisting of 4 different shRNA adenoviruses (reference sample: control shRNA), LCN13 (LCN13 shRNA), TSC22D4 (TSC22D4 shRNA), TSC22D4 plus LCN13 (TSC22D4+LCN13 shRNA). 1 week after shRNA injection animals were sacrificed, liver, abdominal fat tissue, gastrocnemius tissue was immediately snap frozen. 3 representative animals of each treatment group were selected for microarray analysis (abdominal fat tissue).
Project description:The liver may regulate glucose homeostasis by modulating the sensitivity/resistance of peripheral tissues to insulin, by way of the production of secreted proteins, termed hepatokines. To identify hepatic secretory proteins involved in insulin resistance, we performed liver biopsies in humans with or without type 2 diabetes and conducted a comprehensive analysis of gene expression profiles.
Project description:Liver-specific Knockdown of JNK1 Up-regulates Proliferator-activated Receptor Coactivator 1 and Increases Plasma Triglyceride despite Reduced Glucose and Insulin Levels in Diet-induced Obese Mice. The c-Jun N-terminal kinases (JNKs) have been implicated in the development of insulin resistance, diabetes, and obesity. Genetic disruption of JNK1, but not JNK2, improves insulin sensitivity in diet-induced obese (DIO) mice. We applied RNA interference to investigate the specific role of hepatic JNK1 in contributing to insulin resistance in DIO mice. Adenovirus-mediated delivery of JNK1 short-hairpin RNA (Ad-shJNK1) resulted in almost complete knockdown of hepatic JNK1 protein without affecting JNK1 protein in other tissues. Liver-specific knockdown of JNK1 resulted in significant reductions in circulating insulin and glucose levels, by 57 and 16%, respectively. At the molecular level, JNK1 knockdown mice had sustained and significant increase of hepatic Akt phosphorylation. Furthermore, knockdown of JNK1 enhanced insulin signaling in vitro. Unexpectedly, plasma triglyceride levels were robustly elevated upon hepatic JNK1 knockdown. Concomitantly, expression of proliferator-activated receptor coactivator 1, glucokinase, and microsomal triacylglycerol transfer protein was increased. Further gene expression analysis demonstrated that knockdown of JNK1 up-regulates the hepatic expression of clusters of genes in glycolysis and several genes in triglyceride synthesis pathways. Our results demonstrate that liver-specific knockdown of JNK1 lowers circulating glucose and insulin levels but increases triglyceride levels in DIO mice. Experiment Overall Design: Liver sample from vehicle, GFP Adv-shRNA, or Jnk1 Adv-shRNA treated DIO mice with 5, 4, and 5 replicates, respectively
Project description:Inter-tissue communication is a fundamental feature of systemic metabolic regulation and the liver is central to this process. We have identified sparc-related modular calcium-binding protein 1 (SMOC1) as a glucose-responsive hepatokine and potent regulator of glucose homeostasis. Acute administration of recombinant SMOC1 improves glycemic control and insulin sensitivity, independent of changes in insulin secretion. SMOC1 exerts its favourable glycemic effects by inhibiting cAMP-PKA-CREB signaling in the liver, leading to decreased gluconeogenic gene expression and suppression of hepatic glucose output. Over expression of SMOC1 in the liver or once-weekly injections of a stabilized SMOC1-FC fusion protein induces durable improvements in glucose tolerance and insulin sensitivity in db/db mice, without significant adverse effects on adiposity, liver histopathology or inflammation. Furthermore, SMOC1 correlates with systemic insulin sensitivity and is decreased in obese, insulin resistant humans. Together, these findings identify SMOC1 as a potential pharmacological target for the management of glycemic control in type 2 diabetes.