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PMID |
Sentence |
1 |
9399964
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Thus, there are multiple alterations in the early steps of insulin signaling in the ob/ob mouse, with differential regulation of IRS-1 and IRS-2, various PI 3-kinase regulatory isoforms, and a lack of compensation for the decrease in insulin signaling by any of the known alternative pathways at these levels.
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2 |
9519710
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Englitazone did not increase IR, IRS-1/IRS-2, pp60, or MAPK phosphorylation, nor did it enhance insulin's stimulation of these parameters.
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3 |
11259670
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Insulin also inhibited transcription of a reporter gene driven by the human IRS-2 promoter that was transfected into freshly isolated rat hepatocytes.
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4 |
11739098
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After insulin injection, pY of the IR was not different between groups, whereas pY of IRS-1 and IRS-2 was reduced (P < 0.05) in HSD vs.
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5 |
11812758
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In wild-type (WT) mice, insulin increased IRS-2 tyrosine phosphorylation (approximately 2.5-fold) and IRS-2-associated PI 3-kinase activity (approximately 3-fold).
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6 |
11812758
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In conclusion, IRS-2 tyrosine phosphorylation and associated PI 3-kinase activity are markedly enhanced by insulin in the immediate period after exercise.
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7 |
11812758
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IRS-2 signaling can partially account for the increase in insulin-stimulated phosphotyrosine-associated PI 3-kinase activity after exercise.
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8 |
11916925
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This insulin resistance was associated with impaired insulin receptor substrate (IRS)-2-associated phosphatidylinositol 3' (PI3) kinase activation and IRS-2 tyrosine phosphorylation as well as significantly decreased protein kinase C (PKC)-zeta/lambda activation in response to insulin.
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9 |
11964395
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Insulin-stimulated phosphorylation of the insulin receptor, insulin receptor substrate (IRS)-1, and associated phosphatidylinositol 3-kinase were normal in TG mice, whereas IRS-2 protein and phosphorylation were down-regulated compared with control mice.
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10 |
12493745
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Insulin-positive beta-cells were decreased to nearly zero in IRS-2(-/-) mice with diabetes.
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11 |
12941762
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The lack of IRS-2 did not result in enhanced IRS-1 tyrosine phosphorylation or IRS-1-associated phosphatidylinositol (PI) 3-kinase activity on insulin stimulation.
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12 |
12941762
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Total insulin-induced PI 3-kinase activity was decreased by 50% in IRS-2(-/-) hepatocytes, but the translocation of PI-3,4,5-trisphosphate to the plasma membrane in these cells was almost completely abolished.
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13 |
12941762
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Reconstitution of IRS-2(-/-) hepatocytes with adenoviral IRS-2 restored activation of these pathways, demonstrating that IRS-2 is essential for functional insulin signaling in hepatocytes.
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14 |
12941762
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However, insulin was not able to suppress gluconeogenic gene expression in primary hepatocytes lacking IRS-2, but when IRS-2 signaling was reconstituted, these cells recovered this response to insulin.
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15 |
14550282
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Here we tested the hypothesis that the novel analog [LysB3, GluB29] insulin (insulin glulisine, IG) might mediate an enhanced beta-cell protective effect due to its unique property of preferential IRS-2 phosphorylation.
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16 |
15467829
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Diabetes resolved when the mice were between 6 and 10 months of age: functional beta cells expressing Irs2 repopulated the pancreas, restoring sufficient beta cell function to compensate for insulin resistance in the obese mice.
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17 |
15845625
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Semiquantitative RT-PCR analysis showed that insulin (10(4) microU/ml) alone or in combination with glucose (15 mm) markedly suppressed IRS-2 gene expression, whereas IRS-1 mRNA was unaffected by the culture conditions.
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18 |
16170201
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Pten insufficiency increased peripheral insulin sensitivity in wild type and Irs2(-/-) mice and increased Akt and Foxo1 phosphorylation in the islets.
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19 |
16721034
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The data revealed that the administration of a high dose (0.1 mg/kg body weight/day) of DEX (HDEX) attenuated insulin signaling in the cerebral cortex and hypothalamus, whereas exercise potentiated their insulin signaling along with induction of IRS2 expression.
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20 |
16399506
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Conversely, increased PI3K signaling induced by hypothalamic overexpression of either IRS-2 or protein kinase B (PKB, a key downstream mediator of PI3K action) enhanced the glycemic response to insulin by approximately 2-fold in STZ-DM rats.
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21 |
16458527
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The majority of the published literature in this field suggests that IRS1 is the major substrate leading to stimulation of glucose transport in muscle and adipose tissues, whereas in liver, IRS1 and IRS2 have complementary roles in insulin signaling and metabolism.
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22 |
17127239
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Future studies are necessary to determine whether IRS2 dysfunction may promote atherosclerosis in normoglycemic, pre-diabetic patients with clinical manifestations of hyperinsulinemia and insulin resistance.
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23 |
17952839
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This reduction was associated with enhanced tyrosine phosphorylation of IRS2 and serine (473) phosphporylation of Akt, indicating improved hepatic insulin signaling.
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24 |
18202124
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Insulin-stimulated IRS tyrosine phosphorylation was impaired by overepxression of PKC-zeta for IRS-1, -3, and -4 but not IRS-2.
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25 |
18202124
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That is, PI3K activity associated with IRS-2 in response to insulin was similar in control cells and cells overexpressing PKC-zeta.
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26 |
19007436
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In addition, a defect in insulin secretion could occur due to UPS-mediated degradation of IRS2 in the beta-cells of the pancreas.
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27 |
19357831
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In liver, as well as in muscle, IRS-2/PI3K activation by insulin was intact, whereas IRS-1/PI3K activation by insulin was impaired.
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28 |
19357831
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Moreover, hepatic IRS-2 is known to control hepatic aPKC during insulin activation.
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29 |
19818665
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These effects appeared to be independent of IRS-2, which is directly involved in insulin action.
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30 |
18370645
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More recent data on experimental atherosclerosis in the mouse shows that (1) insulin administration reduces the number and the size of atherosclerotic lesions in apo E null mice and (2) in IRS-2 null mice, the interruption in insulin signal transduction results in enhanced atherogenicity.
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31 |
20947509
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We conclude that Igf1r signals primarily through Irs1 and affects insulin secretion, whereas ? cell proliferation is mainly regulated by InsR using Irs2 as a downstream signaling effector.
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32 |
20959116
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Glucose-stimulated insulin secretion was enhanced in islets from male null mice as compared to male WT whereas this response in female Irs-2(-/-) islets was identical to that of female controls.
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33 |
20959116
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The ability of ?(2)-adrenoceptor (?(2)-AR) agonists to inhibit insulin secretion was attenuated in male Irs2 null mice.
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34 |
20028942
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To define the relationship between these two signaling pathways in the regulation of liver metabolism, we used genetic and pharmacological approaches to study the effects of inhibiting PTP1B on hepatic insulin signaling and expression of gluconeogenic enzymes in IRS2(-/-) mice.
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35 |
20028942
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Additionally, hepatic insulin signaling was assessed in control and IRS2(-/-) mice treated with resveratrol, an antioxidant present in red wine.
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36 |
20028942
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By regulating the phosphorylation state of IR, PTB1B determines sensitivity to insulin in liver and exerts a unique role in the interplay between IRS1 and IRS2 in the modulation of hepatic insulin action.
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37 |
20466847
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Genetic and biological studies have shown that reductions in IRS1 and/or IRS2 protein levels are associated with insulin resistance.
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38 |
20466847
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In this study we have shown that proteasome degradation of IRS1, but not of IRS2, is involved in HG-induced insulin resistance in Chinese hamster ovary (CHO) cells as well as in primary hepatocytes.
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39 |
21356512
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In this issue of Cell Metabolism, Kubota et al. (2011) show that deletion of IRS-2 in endothelial cells in mice causes impaired transcapillary insulin transport, decreased insulin-stimulated glucose uptake in muscle, and mild glucose intolerance.
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40 |
21356519
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Moreover, restoration of insulin-induced eNOS phosphorylation in endothelial cells completely reverses the reduction in capillary recruitment and insulin delivery in tissue-specific knockout mice lacking Irs2 in endothelial cells and fed a high-fat diet.
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41 |
21990351
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Hepatic IRS2 protein was dramatically up-regulated in mice treated with T863, possibly contributing to improved insulin sensitivity.
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