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Molecular Mechanism of Metabolic disorders Shinichi Oka, PhD Department of Cell Biology and Molecular Medicine Rutgers New Jersey Medical School MSB-I543 okash@njms.rutgers.edu
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Objectives Leptin Resistance Obese Insulin Resistance Diabetes To understand molecular pathology of obesity and diabetes 1. Leptin Resistance as a mechanism of obesity 2. Insulin Resistance as a mechanism of diabetes 3. Metaflammation link between obesity and diabetes Metaflammation
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Objectives Leptin Resistance Obese Insulin Resistance Diabetes To understand molecular pathology of obesity and diabetes 1. Leptin Resistance as a mechanism of obesity 2. Insulin Resistance as a mechanism of diabetes 3. Metaflammation link between obesity and diabetes Metaflammation
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Leptin resistance causes obesity ob/ob ob/ob; Letpin mutant db/db; Letpin receptor mutant control
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Leptin Leptin (Greek λεπτός (leptos) meaning "thin") is a 16-kDa adipokinekDaadipokine Adipose tissue Leptin Excessive food intake Brain Bloodstream Anorexigenic peptide hormone Orexigenic peptide hormone Reduction of appetite
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Leptin signaling Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Leptin function and signaling Adipose tissue Excessive food intake Brain Leptin Reduction of appetite Bloodstream
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Molecular pathology of Leptin Resistance Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Leptin Resistance
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Leptin-induced JAK2 activation is impaired in Leptin Resistance Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Leptin Resistance
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Leptin Resistance Leptin-induced STAT3 phosphorylation is impaired in Leptin Resistance
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Orexigenic peptide hormones are elevated in Leptin Resistance Leptin Resistance
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Food intake is enhanced in Leptin Resistance Leptin Resistance
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Ren et al, JCI, 2007 Ren et al, Cell Metabolism, 2005 Plasma Leptin is elevated in Leptin Resistance Leptin Resistance
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Leptin JAK2 Anorexigenic peptide hormone Orexigenic peptide hormone STAT3 Plasma membrane P P P P Nucleus Appetite Impaired cellular Leptin signaling Increased orexinenic peptide hormones Reduced anorexigenic peptide hormones Increased plasma leptin Increased food intake Gain body weight Summary Leptin Resistance
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Objectives Leptin Resistance Obese Insulin Resistance Diabetes To understand molecular pathology of obesity and diabetes 1. Leptin Resistance as a mechanism of obesity 2. Insulin Resistance as a mechanism of diabetes 3. Metaflammation link between obesity and diabetes Metaflammation
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Diabetes Diabetes is a metabolic diseases in which a person has high blood glucose. Diabetes causes heart diseases, kidney failure and eye problem.
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Insulin Resistance causes type II diabetes Insulin resistance is defined as a deteriorated response to insulin action. Individuals with insulin resistance are predisposed to developing type 2 diabetes. Insulin resistance is a crucial pathological feature in the type 2 diabetes.
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Insulin A peptide hormone secreted from the Pancreas
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Insulin action Glucose http://trialx.com/curetalk/2011/01/risk-of-cvd-in-diabetes-mellitus-pateints/
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Molecular pathology of insulin resistance Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose
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Hyperglycemia in insulin resistance Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP 3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance
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Glucose tolerance and insulin sensitivity are impaired in insulin resistance Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP 3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance Insulin Resistance Glucose
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Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance Insulin-induced insulin receptor phosphorylation is impaired in insulin resistance
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Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance Insulin-induced insulin receptor substrate (IRS) phosphorylation is impaired in insulin resistance
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Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance Insulin-induced PI3K activation is impaired in insulin resistance PIP3: Phosphatidylinositol triphosphate PIP3
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Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP 3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance Insulin (-) Insulin-induced Akt phosphorylation is impaired in insulin resistance
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Plasma insulin is elevated in insulin resistance Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP 3 P Glut4 ER Glucose Duan et al, MCB, 2004 Insulin Resistance
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Insulin IRS PI3K Plasma membrane P P AKT Insulin Receptor P PDK1 PIP 3 P Glut4 ER Glucose Impaired cellular Insulin signaling Impaired insulin-induced glucose uptake Impaired glucose tolerance Increased plasma Insulin Summary Insulin Resistance
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Objectives Leptin Resistance Obese Insulin Resistance Diabetes To understand molecular pathology of obesity and diabetes 1. Leptin Resistance as a mechanism of obesity 2. Insulin Resistance as a mechanism of diabetes 3. Metaflammation link between obesity and diabetes Metaflammation
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Inflammatory Reaction http://jem.rupress.org/content/203/2/269/F2.large.jpg
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Inflammatory Signaling http://atlasgeneticsoncology.org/Deep/NFKBID20033.html
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Metaflammation link between obese and diabetes Metabolically driven, chronic low-grade of inflammation, termed metaflammation, takes place in obese conditions. JNK Plasma membrane Inflammatory cytokines e.g. TNF- , IL-6 Proinflammatory genes NF B Stress response Receptors Nucleus Inflammatory reactions Host Defense
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Inflammatory reaction inhibits insulin signaling Insulin IRSPI3K P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose JNK Inflammatory cytokines e.g. TNF- , IL-6 Inhibitory phosphorylation Receptors P Obese conditions Hirosumi et al, Nature, 420, 333
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Metaflammation Insulin IRSPI3K P P AKT Insulin Receptor P PDK1 PIP3 P Glut4 ER Glucose JNK Inflammatory cytokines e.g. TNF- , IL-6 Inhibitory phosphorylation Receptors P Obese conditions Summary Chronic low-grade of inflammation, termed metaflammation, takes place in obese conditions. The metaflammation causes insulin resistance partly through inhibitory phosphoryalation of IRS
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