Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.9 (glucose-6-phosphatase)
 3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphoinositide 3-kinase (PI3K) p85alpha-deficient mice exhibit hypoglycemia as a result of increased insulin sensitivity and glucose uptake in peripheral tissues. Although PI3K is central to the metabolic actions of insulin, its mechanism of action in liver is not well understood. In the present study, we investigated hepatic insulin signaling and glucose homeostasis in p85alpha-deficient and wild-type mice. In the livers of p85alpha-deficient mice, p50alpha played a compensatory role in insulin-stimulated PI3K activation by binding to insulin receptor substrate (IRS)-1/2. In p85alpha-deficient mice, the ratio of p50alpha over p110 catalytic subunit of PI3K in the liver was higher than in the muscles. PI3K activity associated with IRS-1/2 was not affected by the lack of p85alpha in the liver. Insulin-stimulated Akt and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) activities in the liver were similar in p85alpha-deficient and wild-type mice. A hyperinsulinemic-euglycemic clamp study revealed that the glucose infusion rate and the rate of disappearance were higher in p85alpha-deficient mice than in wild-type mice but that endogenous glucose production tended to be higher in p85alpha-deficient mice than in wild-type mice. Consistent with this finding, the expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase in livers after fasting was higher in p85alpha-deficient mice than in wild-type mice. After mice were fasted, the intrahepatic glucose-6-phosphate level was almost completely depleted in p85alpha-deficient mice. The glycogen content fell to nearly zero as a result of glycogenolysis shortly after the initiation of fasting in p85alpha-deficient mice. The absence of an increase in insulin-stimulated PI3K activation in the liver of p85alpha-deficient mice, unlike the muscles, may be associated with the molecular balance between the regulatory subunit and the catalytic subunit of PI3K. Gluconeogenesis was rather elevated in p85alpha-deficient mice, compared with in wild-type mice, and the liver seemed to partially compensate for the increase in glucose uptake in peripheral tissues.
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PMID:Role of the liver in glucose homeostasis in PI 3-kinase p85alpha-deficient mice. 1917 57

Exposure to an adverse intrauterine environment increases the risk for adult metabolic syndrome. However, the influence of prenatal hypoxia on the risk of fatty liver disease in offspring is unclear. The purpose of the present study was to evaluate the role of reduced fetal oxygen on the development and severity of high-fat (HF) diet-induced nonalcoholic fatty liver disease (NAFLD). Based on design implicating 2 factors, ie, maternal hypoxia (MH) and postnatal HF diet, blood lipid and insulin levels, hepatic histology, and potential molecular targets were evaluated in male Sprague Dawley rat offspring. MH associated with postnatal HF diet caused a significant increase in plasma concentration of triglycerides, free fatty acids, low-density lipoprotein cholesterol, and insulin. Histologically, a more severe form of NAFLD with hepatic inflammation, hepatic resident macrophage infiltration, and progression toward nonalcoholic steatohepatitis was observed. The lipid homeostasis changes and insulin resistance caused by MH plus HF were accompanied by a significant down-regulation of insulin receptor substrate 2 (IRS-2), phosphoinositide-3 kinase p110 catalytic subunit, and protein kinase B. In MH rats, insulin-stimulated IRS-2 and protein kinase B (AKT) phosphorylation were significantly blunted as well as insulin suppression of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Meanwhile, a significant up-regulation of lipogenic pathways was noticed, including sterol-regulatory element-binding protein-1 and fatty acid synthase in liver. Our results indicate that maternal hypoxia enhances dysmetabolic liver injury in response to an HF diet. Therefore, the offspring born in the context of maternal hypoxia may require special attention and follow-up to prevent the early development of NAFLD.
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PMID:Maternal hypoxia increases the susceptibility of adult rat male offspring to high-fat diet-induced nonalcoholic fatty liver disease. 2400 36