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Sample records for cell glucose metabolism

  1. Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells.

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    Jianhui Liu

    Full Text Available Glucose-stimulated insulin secretion (GSIS is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM. Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells.

  2. Metabolism Kinetics of Glucose in Anchorage-dependent Cell Cultures

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    孙祥明; 张元兴

    2001-01-01

    The kinetic model of glucose metabolism was established and successfully applied to batchcultures of rCHO and rBHK cells. It was found that a large amount of glucose was utilized for cellmaintenance, and the overwhelming majority of maintenance energy from glucose was by its anaerobicmetabolism in both rBHK and rCHO cell cultures. The overall maintenance coefficients from aerobicmetabolism were 1.9×10-13 mmol/(cell.h) for rCHO cells and 7×10-13 mmol/(cell.h) for rBHK cells. Inaddition, all Go/T and Eo/T gradually increased with the same trend as the cell growth in the culture ofboth rCHO and rBHK cells. The overall molecule yield coefficients of lactate to glucose were 1.61 for rCHO cells and 1.38 for rBHK cells. The yield coefficients of cell to glucose were 4.5×108 cells/mmol for rCHO cells and 1.9 × 108 cells/mmol for rBHK cells, respectively.

  3. Glucose metabolism in mammalian cell culture: new insights for tweaking vintage pathways.

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    Mulukutla, Bhanu Chandra; Khan, Salmaan; Lange, Alex; Hu, Wei-Shou

    2010-09-01

    Cultured mammalian cells are major vehicles for producing therapeutic proteins, and energy metabolism in those cells profoundly affects process productivity. The characteristic high glucose consumption and lactate production of industrial cell lines as well as their adverse effects on productivity have been the target of both cell line and process improvement for several decades. Recent research advances have shed new light on regulation of glucose metabolism and its links to cell proliferation. This review highlights our current understanding in this area of crucial importance in bioprocessing and further discusses strategies for harnessing new findings toward process enhancement through the manipulation of cellular energy metabolism.

  4. Metabolic determinants of cancer cell sensitivity to glucose limitation and biguanides

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    Birsoy, Kıvanç; Possemato, Richard; Lorbeer, Franziska K.; Bayraktar, Erol C.; Thiru, Prathapan; Yucel, Burcu; Wang, Tim; Chen, Walter W.; Clish, Clary B.; Sabatini, David M.

    2014-04-01

    As the concentrations of highly consumed nutrients, particularly glucose, are generally lower in tumours than in normal tissues, cancer cells must adapt their metabolism to the tumour microenvironment. A better understanding of these adaptations might reveal cancer cell liabilities that can be exploited for therapeutic benefit. Here we developed a continuous-flow culture apparatus (Nutrostat) for maintaining proliferating cells in low-nutrient media for long periods of time, and used it to undertake competitive proliferation assays on a pooled collection of barcoded cancer cell lines cultured in low-glucose conditions. Sensitivity to low glucose varies amongst cell lines, and an RNA interference (RNAi) screen pinpointed mitochondrial oxidative phosphorylation (OXPHOS) as the major pathway required for optimal proliferation in low glucose. We found that cell lines most sensitive to low glucose are defective in the OXPHOS upregulation that is normally caused by glucose limitation as a result of either mitochondrial DNA (mtDNA) mutations in complex I genes or impaired glucose utilization. These defects predict sensitivity to biguanides, antidiabetic drugs that inhibit OXPHOS, when cancer cells are grown in low glucose or as tumour xenografts. Notably, the biguanide sensitivity of cancer cells with mtDNA mutations was reversed by ectopic expression of yeast NDI1, a ubiquinone oxidoreductase that allows bypass of complex I function. Thus, we conclude that mtDNA mutations and impaired glucose utilization are potential biomarkers for identifying tumours with increased sensitivity to OXPHOS inhibitors.

  5. Akt Requires Glucose Metabolism to Suppress Puma Expression and Prevent Apoptosis of Leukemic T Cells*

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    Coloff, Jonathan L.; Mason, Emily F.; Altman, Brian J.; Gerriets, Valerie A.; Liu, Tingyu; Nichols, Amanda N.; Zhao, Yuxing; Wofford, Jessica A.; Jacobs, Sarah R.; Ilkayeva, Olga; Garrison, Sean P.; Zambetti, Gerard P.; Rathmell, Jeffrey C.

    2011-01-01

    The PI3K/Akt pathway is activated in stimulated cells and in many cancers to promote glucose metabolism and prevent cell death. Although inhibition of Akt-mediated cell survival may provide a means to eliminate cancer cells, this survival pathway remains incompletely understood. In particular, unlike anti-apoptotic Bcl-2 family proteins that prevent apoptosis independent of glucose, Akt requires glucose metabolism to inhibit cell death. This glucose dependence may occur in part through metabolic regulation of pro-apoptotic Bcl-2 family proteins. Here, we show that activated Akt relies on glycolysis to inhibit induction of Puma, which was uniquely sensitive to metabolic status among pro-apoptotic Bcl-2 family members and was rapidly up-regulated in glucose-deficient conditions. Importantly, preventing Puma expression was critical for Akt-mediated cell survival, as Puma deficiency protected cells from glucose deprivation and Akt could not readily block Puma-mediated apoptosis. In contrast, the pro-apoptotic Bcl-2 family protein Bim was induced normally even when constitutively active Akt was expressed, yet Akt could provide protection from Bim cytotoxicity. Up-regulation of Puma appeared mediated by decreased availability of mitochondrial metabolites rather than glycolysis itself, as alternative mitochondrial fuels could suppress Puma induction and apoptosis upon glucose deprivation. Metabolic regulation of Puma was mediated through combined p53-dependent transcriptional induction and control of Puma protein stability, with Puma degraded in nutrient-replete conditions and long lived in nutrient deficiency. Together, these data identify a key role for Bcl-2 family proteins in Akt-mediated cell survival that may be critical in normal immunity and in cancer through Akt-dependent stimulation of glycolysis to suppress Puma expression. PMID:21159778

  6. Arctigenin preferentially induces tumor cell death under glucose deprivation by inhibiting cellular energy metabolism.

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    Gu, Yuan; Qi, Chunting; Sun, Xiaoxiao; Ma, Xiuquan; Zhang, Haohao; Hu, Lihong; Yuan, Junying; Yu, Qiang

    2012-08-15

    Selectively eradicating cancer cells with minimum adverse effects on normal cells is a major challenge in the development of anticancer therapy. We hypothesize that nutrient-limiting conditions frequently encountered by cancer cells in poorly vascularized solid tumors might provide an opportunity for developing selective therapy. In this study, we investigated the function and molecular mechanisms of a natural compound, arctigenin, in regulating tumor cell growth. We demonstrated that arctigenin selectively promoted glucose-starved A549 tumor cells to undergo necrosis by inhibiting mitochondrial respiration. In doing so, arctigenin elevated cellular level of reactive oxygen species (ROS) and blocked cellular energy metabolism in the glucose-starved tumor cells. We also demonstrated that cellular ROS generation was caused by intracellular ATP depletion and played an essential role in the arctigenin-induced tumor cell death under the glucose-limiting condition. Furthermore, we combined arctigenin with the glucose analogue 2-deoxyglucose (2DG) and examined their effects on tumor cell growth. Interestingly, this combination displayed preferential cell-death inducing activity against tumor cells compared to normal cells. Hence, we propose that the combination of arctigenin and 2DG may represent a promising new cancer therapy with minimal normal tissue toxicity.

  7. Methylglyoxal alters glucose metabolism and increases AGEs content in C6 glioma cells.

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    Hansen, Fernanda; de Souza, Daniela Fraga; Silveira, Simone da Luz; Hoefel, Ana Lúcia; Fontoura, Júlia Bijoldo; Tramontina, Ana Carolina; Bobermin, Larissa Daniele; Leite, Marina Concli; Perry, Marcos Luiz Santos; Gonçalves, Carlos Alberto

    2012-12-01

    Methylglyoxal is a dicarbonyl compound that is physiologically produced by enzymatic and non-enzymatic reactions. It can lead to cytotoxicity, which is mainly related to Advanced Glycation End Products (AGEs) formation. Methylglyoxal and AGEs are involved in the pathogenesis of Neurodegenerative Diseases (ND) and, in these situations, can cause the impairment of energetic metabolism. Astroglial cells play critical roles in brain metabolism and the appropriate functioning of astrocytes is essential for the survival and function of neurons. However, there are only a few studies evaluating the effect of methylglyoxal on astroglial cells. The aim of this study was to evaluate the effect of methylglyoxal exposure, over short (1 and 3 h) and long term (24 h) periods, on glucose, glycine and lactate metabolism in C6 glioma cells, as well as investigate the glyoxalase system and AGEs formation. Glucose uptake and glucose oxidation to CO(2) increased in 1 h and the conversion of glucose to lipids increased at 3 h. In addition, glycine oxidation to CO(2) and conversion of glycine to lipids increased at 1 h, whereas the incorporation of glycine in proteins decreased at 1 and 3 h. Methylglyoxal decreased glyoxalase I and II activities and increased AGEs content within 24 h. Lactate oxidation and lactate levels were not modified by methylglyoxal exposure. These data provide evidence that methylglyoxal may impair glucose metabolism and can affect glyoxalase activity. In periods of increased methylglyoxal exposure, such alterations could be exacerbated, leading to further increases in intracellular methylglyoxal and AGEs, and therefore triggering and/or worsening ND.

  8. Elevation in Tanis expression alters glucose metabolism and insulin sensitivity in H4IIE cells.

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    Gao, Yuan; Walder, Ken; Sunderland, Terry; Kantham, Lakshmi; Feng, Helen C; Quick, Melissa; Bishara, Natalie; de Silva, Andrea; Augert, Guy; Tenne-Brown, Janette; Collier, Gregory R

    2003-04-01

    Increased hepatic glucose output and decreased glucose utilization are implicated in the development of type 2 diabetes. We previously reported that the expression of a novel gene, Tanis, was upregulated in the liver during fasting in the obese/diabetic animal model Psammomys obesus. Here, we have further studied the protein and its function. Cell fractionation indicated that Tanis was localized in the plasma membrane and microsomes but not in the nucleus, mitochondria, or soluble protein fraction. Consistent with previous gene expression data, hepatic Tanis protein levels increased more significantly in diabetic P. obesus than in nondiabetic controls after fasting. We used a recombinant adenovirus to increase Tanis expression in hepatoma H4IIE cells and investigated its role in metabolism. Tanis overexpression reduced glucose uptake, basal and insulin-stimulated glycogen synthesis, and glycogen content and attenuated the suppression of PEPCK gene expression by insulin, but it did not affect insulin-stimulated insulin receptor phosphorylation or triglyceride synthesis. These results suggest that Tanis may be involved in the regulation of glucose metabolism, and increased expression of Tanis could contribute to insulin resistance in the liver.

  9. Effects of glucose availability on expression of the key genes involved in synthesis of milk fat, lactose and glucose metabolism in bovine mammary epithelial cells.

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    Hongyun Liu

    Full Text Available As the main precursor for lactose synthesis, large amounts of glucose are required by lactating dairy cows. Milk yield greatly depends on mammary lactose synthesis due to its osmoregulatory property for mammary uptake of water. Thus, glucose availability to the mammary gland could be a potential regulator of milk production. In the present study, the effect of glucose availability on expression of the key genes involved in synthesis of milk fat, lactose and glucose metabolism in vitro was investigated. Bovine mammary epithelial cells (BMEC were treated for 12 h with various concentrations of glucose (2.5, 5, 10 or 20 mmol/L. The higher concentrations of glucose (10-20 mmol/L did not affect the mRNA expression of acetyl-CoA carboxylase, diacyl glycerol acyl transferase, glycerol-3 phosphate acyl transferase and α-lactalbumin, whereas fatty acid synthase, sterol regulatory element binding protein-1 and beta-1, 4-galactosyl transferase mRNA expression increased at 10 mmol/L and then decreased at 20 mmol/L. The content of lactose synthase increased with increasing concentration of glucose, with addition of highest value at 20 mmol/L of glucose. Moreover, the increased glucose concentration stimulated the activities of pyruvate kinase and glucose-6-phosphate dehydrogenase, and elevated the energy status of the BMEC. Therefore, it was deduced that after increasing glucose availability, the extra absorbed glucose was partitioned to entering the synthesis of milk fat and lactose by the regulation of the mRNA expression of key genes, promoting glucose metabolism by glycolysis and pentose phosphate pathway as well as energy status. These results indicated that the sufficient availability of glucose in BMEC may promote glucose metabolism, and affect the synthesis of milk composition.

  10. Glycated albumin suppresses glucose-induced insulin secretion by impairing glucose metabolism in rat pancreatic β-cells

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    Muto Takashi

    2011-04-01

    Full Text Available Abstract Background Glycated albumin (GA is an Amadori product used as a marker of hyperglycemia. In this study, we investigated the effect of GA on insulin secretion from pancreatic β cells. Methods Islets were collected from male Wistar rats by collagenase digestion. Insulin secretion in the presence of non-glycated human albumin (HA and GA was measured under three different glucose concentrations, 3 mM (G3, 7 mM (G7, and 15 mM (G15, with various stimulators. Insulin secretion was measured with antagonists of inducible nitric oxide synthetase (iNOS, and the expression of iNOS-mRNA was investigated by real-time PCR. Results Insulin secretion in the presence of HA and GA was 20.9 ± 3.9 and 21.6 ± 5.5 μU/3 islets/h for G3 (P = 0.920, and 154 ± 9.3 and 126.1 ± 7.3 μU/3 islets/h (P = 0.046, for G15, respectively. High extracellular potassium and 10 mM tolbutamide abrogated the inhibition of insulin secretion by GA. Glyceraldehyde, dihydroxyacetone, methylpyruvate, GLP-1, and forskolin, an activator of adenylate cyclase, did not abrogate the inhibition. Real-time PCR showed that GA did not induce iNOS-mRNA expression. Furthermore, an inhibitor of nitric oxide synthetase, aminoguanidine, and NG-nitro-L-arginine methyl ester did not abrogate the inhibition of insulin secretion. Conclusion GA suppresses glucose-induced insulin secretion from rat pancreatic β-cells through impairment of intracellular glucose metabolism.

  11. Activation of nuclear receptor NR5A2 increases Glut4 expression and glucose metabolism in muscle cells

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    Bolado-Carrancio, A. [Department of Molecular Biology, University of Cantabria, IDIVAL, Santander (Spain); Riancho, J.A. [Department of Internal Medicine, Hospital U.M. Valdecilla-IDIVAL, University of Cantabria, RETICEF, Santander (Spain); Sainz, J. [Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC-University of Cantabria, Santander (Spain); Rodríguez-Rey, J.C., E-mail: rodriguj@unican.es [Department of Molecular Biology, University of Cantabria, IDIVAL, Santander (Spain)

    2014-04-04

    Highlights: • NR5A2 expression in C2C12 is associated with myotube differentiation. • DLPC induces an increase in GLUT4 levels and glucose uptake in C2C12 myotubes. • In high glucose conditions the activation of NR5A2 inhibits fatty acids oxidation. - Abstract: NR5A2 is a nuclear receptor which regulates the expression of genes involved in cholesterol metabolism, pluripotency maintenance and cell differentiation. It has been recently shown that DLPC, a NR5A2 ligand, prevents liver steatosis and improves insulin sensitivity in mouse models of insulin resistance, an effect that has been associated with changes in glucose and fatty acids metabolism in liver. Because skeletal muscle is a major tissue in clearing glucose from blood, we studied the effect of the activation of NR5A2 on muscle metabolism by using cultures of C2C12, a mouse-derived cell line widely used as a model of skeletal muscle. Treatment of C2C12 with DLPC resulted in increased levels of expression of GLUT4 and also of several genes related to glycolysis and glycogen metabolism. These changes were accompanied by an increased glucose uptake. In addition, the activation of NR5A2 produced a reduction in the oxidation of fatty acids, an effect which disappeared in low-glucose conditions. Our results suggest that NR5A2, mostly by enhancing glucose uptake, switches muscle cells into a state of glucose preference. The increased use of glucose by muscle might constitute another mechanism by which NR5A2 improves blood glucose levels and restores insulin sensitivity.

  12. Drosophila adiponectin receptor in insulin producing cells regulates glucose and lipid metabolism by controlling insulin secretion.

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    Su-Jin Kwak

    Full Text Available Adipokines secreted from adipose tissue are key regulators of metabolism in animals. Adiponectin, one of the adipokines, modulates pancreatic beta cell function to maintain energy homeostasis. Recently, significant conservation between Drosophila melanogaster and mammalian metabolism has been discovered. Drosophila insulin like peptides (Dilps regulate energy metabolism similarly to mammalian insulin. However, in Drosophila, the regulatory mechanism of insulin producing cells (IPCs by adipokine signaling is largely unknown. Here, we describe the discovery of the Drosophila adiponectin receptor and its function in IPCs. Drosophila adiponectin receptor (dAdipoR has high homology with the human adiponectin receptor 1. The dAdipoR antibody staining revealed that dAdipoR was expressed in IPCs of larval and adult brains. IPC- specific dAdipoR inhibition (Dilp2>dAdipoR-Ri showed the increased sugar level in the hemolymph and the elevated triglyceride level in whole body. Dilps mRNA levels in the Dilp2>dAdipoR-Ri flies were similar with those of controls. However, in the Dilp2>dAdipoR-Ri flies, Dilp2 protein was accumulated in IPCs, the level of circulating Dilp2 was decreased, and insulin signaling was reduced in the fat body. In ex vivo fly brain culture with the human adiponectin, Dilp2 was secreted from IPCs. These results indicate that adiponectin receptor in insulin producing cells regulates insulin secretion and controls glucose and lipid metabolism in Drosophila melanogaster. This study demonstrates a new adipokine signaling in Drosophila and provides insights for the mammalian adiponectin receptor function in pancreatic beta cells, which could be useful for therapeutic application.

  13. Cell walls of Saccharomyces cerevisiae differentially modulated innate immunity and glucose metabolism during late systemic inflammation.

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    Bushansingh Baurhoo

    Full Text Available BACKGROUND: Salmonella causes acute systemic inflammation by using its virulence factors to invade the intestinal epithelium. But, prolonged inflammation may provoke severe body catabolism and immunological diseases. Salmonella has become more life-threatening due to emergence of multiple-antibiotic resistant strains. Mannose-rich oligosaccharides (MOS from cells walls of Saccharomyces cerevisiae have shown to bind mannose-specific lectin of Gram-negative bacteria including Salmonella, and prevent their adherence to intestinal epithelial cells. However, whether MOS may potentially mitigate systemic inflammation is not investigated yet. Moreover, molecular events underlying innate immune responses and metabolic activities during late inflammation, in presence or absence of MOS, are unknown. METHODS AND PRINCIPAL FINDINGS: Using a Salmonella LPS-induced systemic inflammation chicken model and microarray analysis, we investigated the effects of MOS and virginiamycin (VIRG, a sub-therapeutic antibiotic on innate immunity and glucose metabolism during late inflammation. Here, we demonstrate that MOS and VIRG modulated innate immunity and metabolic genes differently. Innate immune responses were principally mediated by intestinal IL-3, but not TNF-α, IL-1 or IL-6, whereas glucose mobilization occurred through intestinal gluconeogenesis only. MOS inherently induced IL-3 expression in control hosts. Consequent to LPS challenge, IL-3 induction in VIRG hosts but not differentially expressed in MOS hosts revealed that MOS counteracted LPS's detrimental inflammatory effects. Metabolic pathways are built to elucidate the mechanisms by which VIRG host's higher energy requirements were met: including gene up-regulations for intestinal gluconeogenesis (PEPCK and liver glycolysis (ENO2, and intriguingly liver fatty acid synthesis through ATP citrate synthase (CS down-regulation and ATP citrate lyase (ACLY and malic enzyme (ME up-regulations. However, MOS host

  14. Increased glucocorticoid sensitivity in pancreatic beta-cells : Effects on glucose metabolism and insulin release

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    Davani, Behrous

    2003-01-01

    Type 2 diabetes mellitus (T2DM) is characterized by three pathological alterations: (1) insulin resistance in peripheral tissues, (2) increased hepatic glucose production and (3) impaired insulin secretion from the pancreatic beta-cells. Glucocorticoids (GCs) exert profound effects on glucose homeostasis. They decrease glucose uptake and increase hepatic glucose production. In addition, they may directly inhibit insulin release. The main aim of this thesis was to investigate...

  15. Glucose metabolism determines resistance of cancer cells to bioenergetic crisis after cytochrome-c release.

    LENUS (Irish Health Repository)

    Huber, Heinrich J

    2011-03-01

    Many anticancer drugs activate caspases via the mitochondrial apoptosis pathway. Activation of this pathway triggers a concomitant bioenergetic crisis caused by the release of cytochrome-c (cyt-c). Cancer cells are able to evade these processes by altering metabolic and caspase activation pathways. In this study, we provide the first integrated system study of mitochondrial bioenergetics and apoptosis signalling and examine the role of mitochondrial cyt-c release in these events. In accordance with single-cell experiments, our model showed that loss of cyt-c decreased mitochondrial respiration by 95% and depolarised mitochondrial membrane potential ΔΨ(m) from -142 to -88 mV, with active caspase-3 potentiating this decrease. ATP synthase was reversed under such conditions, consuming ATP and stabilising ΔΨ(m). However, the direction and level of ATP synthase activity showed significant heterogeneity in individual cancer cells, which the model explained by variations in (i) accessible cyt-c after release and (ii) the cell\\'s glycolytic capacity. Our results provide a quantitative and mechanistic explanation for the protective role of enhanced glucose utilisation for cancer cells to avert the otherwise lethal bioenergetic crisis associated with apoptosis initiation.

  16. Quercetin and epigallocatechin gallate inhibit glucose uptake and metabolism by breast cancer cells by an estrogen receptor-independent mechanism

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    Moreira, Liliana, E-mail: lilianam87@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Araújo, Isabel, E-mail: isa.araujo013@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Costa, Tito, E-mail: tito.fmup16@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Correia-Branco, Ana, E-mail: ana.clmc.branco@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Faria, Ana, E-mail: anafaria@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Chemistry Investigation Centre (CIQ), Faculty of Sciences of University of Porto, Rua Campo Alegre, 4169-007 Porto (Portugal); Faculty of Nutrition and Food Sciences of University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Martel, Fátima, E-mail: fmartel@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Keating, Elisa, E-mail: keating@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal)

    2013-07-15

    In this study we characterized {sup 3}H-2-deoxy-D-glucose ({sup 3}H -DG) uptake by the estrogen receptor (ER)-positive MCF7 and the ER-negative MDA-MB-231 human breast cancer cell lines and investigated the effect of quercetin (QUE) and epigallocatechin gallate (EGCG) upon {sup 3}H-DG uptake, glucose metabolism and cell viability and proliferation. In both MCF7 and MDA-MB-231 cells {sup 3}H-DG uptake was (a) time-dependent, (b) saturable with similar capacity (V{sub max}) and affinity (K{sub m}), (c) potently inhibited by cytochalasin B, an inhibitor of the facilitative glucose transporters (GLUT), (d) sodium-independent and (e) slightly insulin-stimulated. This suggests that {sup 3}H-DG uptake by both cell types is mediated by members of the GLUT family, including the insulin-responsive GLUT4 or GLUT12, while being independent of the sodium-dependent glucose transporter (SGLT1). QUE and EGCG markedly and concentration-dependently inhibited {sup 3}H-DG uptake by MCF7 and by MDA-MB-231 cells, and both compounds blocked lactate production by MCF7 cells. Additionally, a 4 h-treatment with QUE or EGCG decreased MCF7 cell viability and proliferation, an effect that was more potent when glucose was available in the extracellular medium. Our results implicate QUE and EGCG as metabolic antagonists in breast cancer cells, independently of estrogen signalling, and suggest that these flavonoids could serve as therapeutic agents/adjuvants even for ER-negative breast tumors. -- Highlights: • Glucose uptake by MCF7 and MDA-MB-231 cells is mainly mediated by GLUT1. • QUE and EGCG inhibit cellular glucose uptake thus abolishing the Warburg effect. • This process induces cytotoxicity and proliferation arrest in MCF7 cells. • The flavonoids’ effects are independent of estrogen receptor signalling.

  17. Glucose metabolism and glutamate analog acutely alkalinize pH of insulin secretory vesicles of pancreatic beta-cells.

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    Eto, Kazuhiro; Yamashita, Tokuyuki; Hirose, Kenzo; Tsubamoto, Yoshiharu; Ainscow, Edward K; Rutter, Guy A; Kimura, Satoshi; Noda, Mitsuhiko; Iino, Masamitsu; Kadowaki, Takashi

    2003-08-01

    We studied acute changes of secretory vesicle pH in pancreatic beta-cells with a fluorescent pH indicator, lysosensor green DND-189. Fluorescence was decreased by 0.66 +/- 0.10% at 149 +/- 16 s with 22.2 mM glucose stimulation, indicating that vesicular pH was alkalinized by approximately 0.016 unit. Glucose-responsive pH increase was observed when cytosolic Ca2+ influx was blocked but disappeared when an inhibitor of glycolysis or mitochondrial ATP synthase was present. Glutamate dimethyl ester (GME), a plasma membrane-permeable analog of glutamate, potentiated glucose-stimulated insulin secretion at 5 mM without changing cellular ATP content or cytosolic Ca2+ concentration ([Ca2+]). Application of GME at basal glucose concentration decreased DND-189 fluorescence by 0.83 +/- 0.19% at 38 +/- 2 s. These results indicated that the acutely alkalinizing effect of glucose on beta-cell secretory vesicle pH was dependent on glucose metabolism but independent of modulations of cytosolic [Ca2+]. Moreover, glutamate derived from glucose may be one of the mediators of this alkalinizing effect of glucose, which may have potential relevance to the alteration of secretory function by glutamate.

  18. Uptake and metabolism of D-glucose in isolated acinar and ductal cells from rat submandibular glands.

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    Cetik, Sibel; Rzajeva, Aigun; Hupkens, Emeline; Malaisse, Willy J; Sener, Abdullah

    2014-07-01

    The present study deals with the possible effects of selected environmental agents upon the uptake and metabolism of d-glucose in isolated acinar and ductal cells from the rat submandibular salivary gland. In acinar cells, the uptake of d-[U-(14) C]glucose and its non-metabolised analogue 3-O-[(14) C-methyl]-d-glucose was not affected significantly by phloridzin (0.1 mM) or substitution of extracellular NaCl (115 mM) by an equimolar amount of CsCl, whilst cytochalasin B (20 μM) decreased significantly such an uptake. In ductal cells, both phloridzin and cytochalasin B decreased the uptake of d-glucose and 3-O-methyl-d-glucose. Although the intracellular space was comparable in acinar and ductal cells, the catabolism of d-glucose (2.8 or 8.3 mM) was two to four times higher in ductal cells than in acinar cells. Phloridzin (0.1 mM), ouabain (1.0 mM) and cytochalasin B (20 μM) all impaired d-glucose catabolism in ductal cells. Such was also the case in ductal cells incubated in the absence of extracellular Ca(2+) or in media in which NaCl was substituted by CsCl. It is proposed that the ductal cells in the rat submandibular gland are equipped with several systems mediating the insulin-sensitive, cytochalasin B-sensitive and phloridzin-sensitive transport of d-glucose across the plasma membrane.

  19. Antihypertensive drugs and glucose metabolism

    Institute of Scientific and Technical Information of China (English)

    Christos; V; Rizos; Moses; S; Elisaf

    2014-01-01

    Hypertension plays a major role in the development and progression of micro-and macrovascular disease.Moreover,increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance.As a result the need for a comprehensive management of hypertensive patients is critical.However,the various antihypertensive drug categories have different effects on glucose metabolism.Indeed,angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis.Calcium channel blockers(CCBs)have an overall neutral effect on glucose metabolism.However,some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis.On the other hand,diuretics andβ-blockers have an overall disadvantageous effect on glucose metabolism.Of note,carvedilol as well as nebivolol seem to differentiate themselves from the rest of theβ-blockers class,being more attractive options regarding their effect on glucose homeostasis.The adverse effects of some blood pressure lowering drugs on glucose metabolism may,to an extent,compromise their cardiovascular protective role.As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment,especially in patients which are at high risk for developing diabetes.

  20. High Glucose-Induced PC12 Cell Death by Increasing Glutamate Production and Decreasing Methyl Group Metabolism

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    Minjiang Chen

    2016-01-01

    Full Text Available Objective. High glucose- (HG- induced neuronal cell death is responsible for the development of diabetic neuropathy. However, the effect of HG on metabolism in neuronal cells is still unclear. Materials and Methods. The neural-crest derived PC12 cells were cultured for 72 h in the HG (75 mM or control (25 mM groups. We used NMR-based metabolomics to examine both intracellular and extracellular metabolic changes in HG-treated PC12 cells. Results. We found that the reduction in intracellular lactate may be due to excreting more lactate into the extracellular medium under HG condition. HG also induced the changes of other energy-related metabolites, such as an increased succinate and creatine phosphate. Our results also reveal that the synthesis of glutamate from the branched-chain amino acids (isoleucine and valine may be enhanced under HG. Increased levels of intracellular alanine, phenylalanine, myoinositol, and choline were observed in HG-treated PC12 cells. In addition, HG-induced decreases in intracellular dimethylamine, dimethylglycine, and 3-methylhistidine may indicate a downregulation of methyl group metabolism. Conclusions. Our metabolomic results suggest that HG-induced neuronal cell death may be attributed to a series of metabolic changes, involving energy metabolism, amino acids metabolism, osmoregulation and membrane metabolism, and methyl group metabolism.

  1. Glucagon like peptide-1-induced glucose metabolism in differentiated human muscle satellite cells is attenuated by hyperglycemia.

    Directory of Open Access Journals (Sweden)

    Charlotte J Green

    Full Text Available BACKGROUND: Glucagon like peptide-1 (GLP-1 stimulates insulin secretion from the pancreas but also has extra-pancreatic effects. GLP-1 may stimulate glucose uptake in cultured muscle cells but the mechanism is not clearly defined. Furthermore, while the pancreatic effects of GLP-1 are glucose-dependent, the glucose-dependency of its extra-pancreatic effects has not been examined. METHODS: Skeletal muscle satellite cells isolated from young (22.5 ± 0.97 yr, lean (BMI 22.5 ± 0.6 kg/m(2, healthy males were differentiated in media containing either 22.5 mM (high or 5 mM (normal glucose for 7 days in the absence or presence of insulin and/or various GLP-1 concentrations. Myocellular effects of GLP-1, insulin and glucose were assessed by western-blot, glucose uptake and glycogen synthesis. RESULTS: We firstly show that the GLP-1 receptor protein is expressed in differentiated human muscle satellite cells (myocytes. Secondly, we show that in 5 mM glucose media, exposure of myocytes to GLP-1 results in a dose dependent increase in glucose uptake, GLUT4 amount and subsequently glycogen synthesis in a PI3K dependent manner, independent of the insulin signaling cascade. Importantly, we provide evidence that differentiation of human satellite cells in hyperglycemic (22.5 mM glucose conditions increases GLUT1 expression, and renders the cells insulin resistant and interestingly GLP-1 resistant in terms of glucose uptake and glycogen synthesis. Hyperglycemic conditions did not affect the ability of insulin to phosphorylate downstream targets, PKB or GSK3. Interestingly we show that at 5 mM glucose, GLP-1 increases GLUT4 protein levels and that this effect is abolished by hyperglycemia. CONCLUSIONS: GLP-1 increases glucose uptake and glycogen synthesis into fully-differentiated human satellite cells in a PI3-K dependent mechanism potentially through increased GLUT4 protein levels. The latter occurs independently of the insulin signaling pathway. Attenuation

  2. Mayaro virus infection alters glucose metabolism in cultured cells through activation of the enzyme 6-phosphofructo 1-kinase.

    Science.gov (United States)

    El-Bacha, Tatiana; Menezes, Maíra M T; Azevedo e Silva, Melissa C; Sola-Penna, Mauro; Da Poian, Andrea T

    2004-11-01

    Although it is well established that cellular transformation with tumor virus leads to changes on glucose metabolism, the effects of cell infection by non-transforming virus are far to be completely elucidated. In this study, we report the first evidence that cultured Vero cells infected with the alphavirus Mayaro show several alterations on glucose metabolism. Infected cells presented a two fold increase on glucose consumption, accompanied by an increment in lactate production. This increase in glycolytic flux was also demonstrated by a significant increase on the activity of 6-phosphofructo 1-kinase, one of the regulatory enzymes of glycolysis. Analysis of the kinetic parameters revealed that the regulation of 6-phosphofructo 1-kinase is altered in infected cells, presenting an increase in Vmax along with a decrease in Km for fructose-6-phosphate. Another fact contributing to an increase in enzyme activity was the decrease in ATP levels observed in infected cells. Additionally, the levels of fructose 2,6-bisphosphate, a potent activator of this enzyme, was significantly reduced in infected cells. These observations suggest that the increase in PFK activity may be a compensatory cellular response to the viral-induced metabolic alterations that could lead to an impairment of the glycolytic flux and energy production.

  3. Glucose metabolism and hyperglycemia.

    Science.gov (United States)

    Giugliano, Dario; Ceriello, Antonio; Esposito, Katherine

    2008-01-01

    Islet dysfunction and peripheral insulin resistance are both present in type 2 diabetes and are both necessary for the development of hyperglycemia. In both type 1 and type 2 diabetes, large, prospective clinical studies have shown a strong relation between time-averaged mean values of glycemia, measured as glycated hemoglobin (HbA1c), and vascular diabetic complications. These studies are the basis for the American Diabetes Association's current recommended treatment goal that HbA1c should be regulation is accompanied by a significant improvement of many pathways supposed to be involved in diabetic complications, including oxidative stress, endothelial dysfunction, inflammation, and nuclear factor-kappaB activation. The goal of therapy should be to achieve glycemic status as near to normal as safely possible in all 3 components of glycemic control: HbA1c, fasting glucose, and postmeal glucose peak.

  4. Dysregulation of Dicer1 in Beta Cells Impairs Islet Architecture and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Amitai D. Mandelbaum

    2012-01-01

    Full Text Available microRNAs (miRNAs play important roles in pancreas development and in regulation of insulin expression in the adult. Here we show that loss of miRNAs activity in beta-cells during embryonic development results in lower beta-cell mass and in impaired glucose tolerance. Dicer1-null cells initially constitute a significant portion of the total beta-cell population. However, during postnatal development, Dicer1-null cells are depleted. Furthermore, wild-type beta cells are repopulating the islets in complex compensatory dynamics. Because loss of Dicer1 is also associated with changes in the distribution of membranous E-cadherin, we hypothesized that E-cadherin activity may play a role in beta cell survival or islet architecture. However, genetic loss of E-cadherin function does not impair islet architecture, suggesting that miRNAs likely function through other or redundant effectors in the endocrine pancreas.

  5. Defective glucose and lipid metabolism in human immunodeficiency virus-infected patients with lipodystrophy involve liver, muscle tissue and pancreatic beta-cells

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Dela, Flemming

    2005-01-01

    of glucose metabolism, lipid metabolism and beta-cell function in lipodystrophic HIV-infected patients. METHODS: [3-3H]glucose was applied during euglycaemic hyperinsulinaemic clamps in association with indirect calorimetry in 43 normoglycaemic HIV-infected patients (18 lipodystrophic patients on HAART (LIPO......), 18 patients without lipodystrophy on HAART (NONLIPO) and seven patients who were naive to antiretroviral therapy (NAIVE) respectively). beta-cell function was evaluated by an intravenous glucose tolerance test. RESULTS: Compared with NONLIPO and NAIVE separately, LIPO displayed markedly reduced ratio.......01. Disposition index (i.e. first-phase insulin response to intravenous glucose multiplied by incremental glucose disposal) was reduced by 46% (P = 0.05) in LIPO compared with the combined groups of NONLIPO and NAIVE, indicating an impaired adaptation of beta-cell function to insulin resistance in LIPO...

  6. Combination of temozolomide and Taxol exerts a synergistic inhibitory effect on Taxol‑resistant glioma cells via inhibition of glucose metabolism.

    Science.gov (United States)

    Guan, Ding-Guo; Chen, Han-Min; Liao, Sheng-Fang; Zhao, Tian-Zhi

    2015-11-01

    Malignant gliomas, which comprise the most common type of primary malignant brain tumor, are associated with a poor prognosis and quality of life. Paclitaxel (Taxol) and temozolomide (TMZ) are Food and Drug Administration‑approved anticancer agents, which are known to have therapeutic applications in various malignancies. However, similar to other chemotherapeutic agents, the development of resistance to TMZ and Taxol is common. The aim of the present study was to investigate the regulation of glucose metabolism by TMZ and Taxol in glioma cells. The results demonstrated that glioma cells exhibit decreased glucose uptake and lactate production in response to treatment with TMZ; however, glucose metabolism was increased in response to Taxol treatment. Following analysis of TMZ‑ and Taxol‑resistant cell lines, it was reported that glucose metabolism was decreased in the TMZ‑resistant cells, but was increased in the Taxol‑resistant cells. Notably, a combination of TMZ and Taxol exerted synergistic inhibitory effects on Taxol‑resistant glioma cells. However, the synergistic phenotype was not observed following treatment with a combination of 5‑fluorouracil and Taxol. Furthermore, restoration of glucose metabolism by overexpression of glucose transporter 1 in Taxol‑resistant cells resulted in regained resistance to Taxol. Therefore, the present study proposes a novel mechanism accounting for the synergistic effects of Taxol and TMZ co‑treatment, which may contribute to the development of therapeutic strategies for overcoming chemoresistance in patients with cancer.

  7. PGC-1α integrates glucose metabolism and angiogenesis in multiple myeloma cells by regulating VEGF and GLUT-4.

    Science.gov (United States)

    Cao, Dedong; Zhou, Hao; Zhao, Jikai; Jin, Lu; Yu, Wen; Yan, Han; Hu, Yu; Guo, Tao

    2014-03-01

    Human peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) is a key coactivator in the regulation of gene transcriptional activity in normal tissues. However, it is not clear whether it is involved in the angiogenesis and metabolism of multiple myeloma (MM). The aim of the present study was to investigate the role of PGC-1α in MM. Small interfering RNA (siRNA) was used to inhibit PGC-1α expression in RPMI-8226 cells. An endothelial cell migration assay was performed using transwell chambers and the expression of PGC-1α, estrogen-related receptor-α (ERR-α), vascular endothelial growth factor (VEGF) and glucose transporter-4 (GLUT-4) was tested by reverse transcription-polymerase chain reaction (RT-PCR). The protein expression of PGC-1α, ERR-α and GLUT-4 was assayed by western blot analysis. Lastly, RPMI-8226 cell proliferation was evaluated using CCK-8 assay. VEGF and GLUT-4 mRNA levels were decreased in cells treated with siRNA targeting PGC-1α, as was the level of GLUT-4 protein. Endothelial cell migration was significantly reduced when these cells were cultured with culture medium from RPMI-8226 cells treated with siPGC-1α. The proliferation rates at 24 and 48 h were suppressed by PGC-1α inhibition. Our results showed that inhibition of PGC-1α suppresses cell proliferation probably by downregulation of VEGF and GLUT-4. The present study suggests that PGC-1α integrates angiogenesis and glucose metabolism in myeloma through regulation of VEGF and GLUT-4.

  8. Comparative effects of fructose and glucose on lipogenic gene expression and intermediary metabolism in HepG2 liver cells.

    Directory of Open Access Journals (Sweden)

    Kristin M Hirahatake

    Full Text Available Consumption of large amounts of fructose or sucrose increases lipogenesis and circulating triglycerides in humans. Although the underlying molecular mechanisms responsible for this effect are not completely understood, it is possible that as reported for rodents, high fructose exposure increases expression of the lipogenic enzymes fatty acid synthase (FAS and acetyl-CoA carboxylase (ACC-1 in human liver. Since activation of the hexosamine biosynthesis pathway (HBP is associated with increases in the expression of FAS and ACC-1, it raises the possibility that HBP-related metabolites would contribute to any increase in hepatic expression of these enzymes following fructose exposure. Thus, we compared lipogenic gene expression in human-derived HepG2 cells after incubation in culture medium containing glucose alone or glucose plus 5 mM fructose, using the HBP precursor 10 mM glucosamine (GlcN as a positive control. Cellular metabolite profiling was conducted to analyze differences between glucose and fructose metabolism. Despite evidence for the active uptake and metabolism of fructose by HepG2 cells, expression of FAS or ACC-1 did not increase in these cells compared with those incubated with glucose alone. Levels of UDP-N-acetylglucosamine (UDP-GlcNAc, the end-product of the HBP, did not differ significantly between the glucose and fructose conditions. Exposure to 10 mM GlcN for 10 minutes to 24 hours resulted in 8-fold elevated levels of intracellular UDP-GlcNAc (P<0.001, as well as a 74-126% increase in FAS (P<0.05 and 49-95% increase in ACC-1 (P<0.01 expression above controls. It is concluded that in HepG2 liver cells cultured under standard conditions, sustained exposure to fructose does not result in an activation of the HBP or increased lipogenic gene expression. Should this scenario manifest in human liver in vivo, it would suggest that high fructose consumption promotes triglyceride synthesis primarily through its action to provide lipid

  9. Arginine deiminase resistance in melanoma cells is associated with metabolic reprogramming, glucose dependence, and glutamine addiction.

    Science.gov (United States)

    Long, Yan; Tsai, Wen-Bin; Wangpaichitr, Medhi; Tsukamoto, Takashi; Savaraj, Niramol; Feun, Lynn G; Kuo, Macus Tien

    2013-11-01

    Many malignant human tumors, including melanomas, are auxotrophic for arginine due to reduced expression of argininosuccinate synthetase-1 (ASS1), the rate-limiting enzyme for arginine biosynthesis. Pegylated arginine deiminase (ADI-PEG20), which degrades extracellular arginine, resulting in arginine deprivation, has shown favorable results in clinical trials for treating arginine-auxotrophic tumors. Drug resistance is the major obstacle for effective ADI-PEG20 usage. To elucidate mechanisms of resistance, we established several ADI-PEG20-resistant (ADI(R)) variants from A2058 and SK-Mel-2 melanoma cells. Compared with the parental lines, these ADI(R) variants showed the following characteristics: (i) all ADI(R) cell lines showed elevated ASS1 expression, resulting from the constitutive binding of the transcription factor c-Myc on the ASS1 promoter, suggesting that elevated ASS1 is the major mechanism of resistance; (ii) the ADI(R) cell lines exhibited enhanced AKT signaling and were preferentially sensitive to PI3K/AKT inhibitors, but reduced mTOR signaling, and were preferentially resistant to mTOR inhibitor; (iii) these variants showed enhanced expression of glucose transporter-1 and lactate dehydrogenase-A, reduced expression of pyruvate dehydrogenase, and elevated sensitivity to the glycolytic inhibitors 2-deoxy-glucose and 3-bromopyruvate, consistent with the enhanced glycolytic pathway (the Warburg effect); (iv) the resistant cells showed higher glutamine dehydrogenase and glutaminase expression and were preferentially vulnerable to glutamine inhibitors. We showed that c-Myc, not elevated ASS1 expression, is involved in upregulation of many of these enzymes because knockdown of c-Myc reduced their expression, whereas overexpressed ASS1 by transfection reduced their expression. This study identified multiple targets for overcoming ADI-PEG resistance in cancer chemotherapy using recombinant arginine-degrading enzymes.

  10. Effects of Simvastatin on Glucose Metabolism in Mouse MIN6 Cells

    Directory of Open Access Journals (Sweden)

    Jieqiong Zhou

    2014-01-01

    Full Text Available The aim of this study was to investigate the effects of simvastatin on insulin secretion in mouse MIN6 cells and the possible mechanism. MIN6 cells were, respectively, treated with 0 μM, 2 μM, 5 μM, and 10 μM simvastatin for 48 h. Radio immunoassay was performed to measure the effect of simvastatin on insulin secretion in MIN6 cells. Luciferase method was used to examine the content of ATP in MIN6 cells. Real-time PCR and western blotting were performed to measure the mRNA and protein levels of inward rectifier potassium channel 6.2 (Kir6.2, voltage-dependent calcium channel 1.2 (Cav1.2, and glucose transporter-2 (GLUT2, respectively. ATP-sensitive potassium current and L-type calcium current were recorded by whole-cell patch-clamp technique. The results showed that high concentrations of simvastatin (5 μM and 10 μM significantly reduced the synthesis and secretion of insulin compared to control groups in MIN6 cells (P<0.05. ATP content in simvastatin-treated cells was lower than in control cells (P<0.05. Compared with control group, the mRNA and protein expression of Kir6.2 increased with treatment of simvastatin (P<0.05, and mRNA and protein expression of Cav1.2 and GLUT2 decreased in response to simvastatin (P<0.05. Moreover, simvastatin increased the ATP-sensitive potassium current and reduced the L-type calcium current. These results suggest that simvastatin inhibits the synthesis and secretion of insulin through a reduction in saccharometabolism in MIN6 cells.

  11. Defective glucose and lipid metabolism in human immunodeficiency virus-infected patients with lipodystrophy involve liver, muscle tissue and pancreatic beta-cells

    DEFF Research Database (Denmark)

    2005-01-01

    of glucose metabolism, lipid metabolism and beta-cell function in lipodystrophic HIV-infected patients. METHODS: [3-3H]glucose was applied during euglycaemic hyperinsulinaemic clamps in association with indirect calorimetry in 43 normoglycaemic HIV-infected patients (18 lipodystrophic patients on HAART (LIPO....... CONCLUSION: Our data suggest that normoglycaemic lipodystrophic HIV-infected patients display impaired glucose and lipid metabolism in multiple pathways involving liver, muscle tissue and beta-cell function.......OBJECTIVES: Lipodystrophy and insulin resistance are prevalent among human immunodeficiency virus (HIV)-infected patients on combined antiretroviral therapy (HAART). Aiming to provide a detailed description of the metabolic adverse effects of HIV-lipodystrophy, we investigated several aspects...

  12. SLC30A3 responds to glucose- and zinc variations in beta-cells and is critical for insulin production and in vivo glucose-metabolism during beta-cell stress.

    Directory of Open Access Journals (Sweden)

    Kamille Smidt

    Full Text Available BACKGROUND: Ion transporters of the Slc30A- (ZnT- family regulate zinc fluxes into sub-cellular compartments. beta-cells depend on zinc for both insulin crystallization and regulation of cell mass. METHODOLOGY/PRINCIPAL FINDINGS: This study examined: the effect of glucose and zinc chelation on ZnT gene and protein levels and apoptosis in beta-cells and pancreatic islets, the effects of ZnT-3 knock-down on insulin secretion in a beta-cell line and ZnT-3 knock-out on glucose metabolism in mice during streptozotocin-induced beta-cell stress. In INS-1E cells 2 mM glucose down-regulated ZnT-3 and up-regulated ZnT-5 expression relative to 5 mM. 16 mM glucose increased ZnT-3 and decreased ZnT-8 expression. Zinc chelation by DEDTC lowered INS-1E insulin content and insulin expression. Furthermore, zinc depletion increased ZnT-3- and decreased ZnT-8 gene expression whereas the amount of ZnT-3 protein in the cells was decreased. Zinc depletion and high glucose induced apoptosis and necrosis in INS-1E cells. The most responsive zinc transporter, ZnT-3, was investigated further; by immunohistochemistry and western blotting ZnT-3 was demonstrated in INS-1E cells. 44% knock-down of ZnT-3 by siRNA transfection in INS-1E cells decreased insulin expression and secretion. Streptozotocin-treated mice had higher glucose levels after ZnT-3 knock-out, particularly in overt diabetic animals. CONCLUSION/SIGNIFICANCE: Zinc transporting proteins in beta-cells respond to variations in glucose and zinc levels. ZnT-3, which is pivotal in the development of cellular changes as also seen in type 2 diabetes (e.g. amyloidosis in Alzheimer's disease but not previously described in beta-cells, is present in this cell type, up-regulated by glucose in a concentration dependent manner and up-regulated by zinc depletion which by contrast decreased ZnT-3 protein levels. Knock-down of the ZnT-3 gene lowers insulin secretion in vitro and affects in vivo glucose metabolism after

  13. [Glucose Metabolism: Stress Hyperglycemia and Glucose Control].

    Science.gov (United States)

    Tanaka, Katsuya; Tsutsumi, Yasuo M

    2016-05-01

    It is important for the anesthesiologists to understand pathophysiology of perioperative stress hyperglycemia, because it offers strategies for treatment of stress hyperglycemia. The effect of glucose tolerance is different in the choice of the anesthetic agent used in daily clinical setting. Specifically, the volatile anesthetics inhibit insulin secretion after glucose load and affects glucose tolerance. During minor surgery by the remifentanil anesthesia, the stress reaction is hard to be induced, suggesting that we should consider low-dose glucose load. Finally it is necessary to perform the glycemic control of the patients who fell into stress hyperglycemia depending on the individual patient. However, there are a lot of questions to be answered in the future. The prognosis of the perioperative patients is more likely to be greatly improved if we can control stress hyperglycemia.

  14. Sex steroids and glucose metabolism

    Directory of Open Access Journals (Sweden)

    Carolyn A Allan

    2014-04-01

    Full Text Available Testosterone levels are lower in men with metabolic syndrome and type 2 diabetes mellitus (T2DM and also predict the onset of these adverse metabolic states. Body composition (body mass index, waist circumference is an important mediator of this relationship. Sex hormone binding globulin is also inversely associated with insulin resistance and T2DM but the data regarding estrogen are inconsistent. Clinical models of androgen deficiency including Klinefelter's syndrome and androgen deprivation therapy in the treatment of advanced prostate cancer confirm the association between androgens and glucose status. Experimental manipulation of the insulin/glucose milieu and suppression of endogenous testicular function suggests the relationship between androgens and insulin sensitivity is bidirectional. Androgen therapy in men without diabetes is not able to differentiate the effect on insulin resistance from that on fat mass, in particular visceral adiposity. Similarly, several small clinical studies have examined the efficacy of exogenous testosterone in men with T2DM, however, the role of androgens, independent of body composition, in modifying insulin resistance is uncertain.

  15. Glucagon like peptide-1-induced glucose metabolism in differentiated human muscle satellite cells is attenuated by hyperglycemia

    DEFF Research Database (Denmark)

    Green, Charlotte J; Henriksen, Tora I; Pedersen, Bente K;

    2012-01-01

    Glucagon like peptide-1 (GLP-1) stimulates insulin secretion from the pancreas but also has extra-pancreatic effects. GLP-1 may stimulate glucose uptake in cultured muscle cells but the mechanism is not clearly defined. Furthermore, while the pancreatic effects of GLP-1 are glucose-dependent......, the glucose-dependency of its extra-pancreatic effects has not been examined....

  16. Melatonin and glucose metabolism: clinical relevance.

    Science.gov (United States)

    Lardone, P J; Alvarez-Sanchez, Sanchez N; Guerrero, J M; Carrillo-Vico, A

    2014-01-01

    The role of melatonin in glucose homeostasis is an active area of investigation. There is a growing body of evidence suggesting a link between disturbances in melatonin production and impaired insulin, glucose, lipid metabolism, and antioxidant capacity. Furthermore, melatonin has been found to influence insulin secretion both in vivo and in vitro, and night-time melatonin levels are related to night-time insulin concentrations in patients with diabetes. In several recent studies, a single nucleotide polymorphism of the human melatonin receptor 1B has been described as being causally linked to an increased risk of developing type 2 diabetes. Taken together, these data suggest that endogenous as well as exogenous melatonin may play a role in diabetes and associated metabolic disturbances not only by regulating insulin secretion but also by providing protection against reactive oxygen species, considering pancreatic β-cells are particularly susceptible to oxidative stress because they possess only low-antioxidative capacity.

  17. Elevated White Blood Cell Count Is Associated with Higher Risk of Glucose Metabolism Disorders in Middle-Aged and Elderly Chinese People

    Directory of Open Access Journals (Sweden)

    Hua Jiang

    2014-05-01

    Full Text Available White blood cell (WBC count has been associated with diabetic risk, but whether the correlation is independent of other risk factors has hardly been studied. Moreover, very few such studies with large sample sizes have been conducted in Chinese. Therefore, we investigated the relationship between WBC count and glucose metabolism in china. We also examined the relevant variables of WBC count. A total of 9,697 subjects (mean age, 58.0 ± 9.1 years were recruited. The subjects were classified into four groups, including subjects with normal glucose tolerance, isolated impaired fasting glucose, impaired glucose tolerance and type 2 diabetes mellitus (T2DM. We found that WBC count increased as glucose metabolism disorders exacerbated. WBC count was also positively correlated with waist hip ratio, body mass index, smoking, triglycerides, glycosylated haemoglobin A1c (HbA1c and 2-h postprandial glucose. In addition, high density lipoprotein and the female gender were inversely correlated with WBC count. In patients with previously diagnosed T2DM, the course of T2DM was not correlated with WBC count. Our findings indicate that elevated WBC count is independently associated with worsening of glucose metabolism in middle-aged and elderly Chinese. In addition, loss of weight, smoking cessation, lipid-modifying therapies, and control of postprandial plasma glucose and HbA1c may ameliorate the chronic low-grade inflammation.

  18. Biosynthesis of highly enriched 13C-lycopene for human metabolic studies using repeated batch tomato cell culturing with 13C-glucose

    OpenAIRE

    Moran, Nancy E.; Rogers, Randy B.; Lu, Chi-Hua; Conlon, Lauren E.; Lila, Mary Ann; Clinton, Steven K.; Erdman, John W

    2013-01-01

    While putative disease-preventing lycopene metabolites are found in both tomato (Solanum lycopersicum) products and in their consumers, mammalian lycopene metabolism is poorly understood. Advances in tomato cell culturing techniques offer an economical tool for generation of highly-enriched 13C-lycopene for human bioavailability and metabolism studies. To enhance the 13C-enrichment and yields of labeled lycopene from the hp-1 tomato cell line, cultures were first grown in 13C-glucose media fo...

  19. FGF19 regulates cell proliferation, glucose and bile acid metabolism via FGFR4-dependent and independent pathways.

    Directory of Open Access Journals (Sweden)

    Ai-Luen Wu

    Full Text Available Fibroblast growth factor 19 (FGF19 is a hormone-like protein that regulates carbohydrate, lipid and bile acid metabolism. At supra-physiological doses, FGF19 also increases hepatocyte proliferation and induces hepatocellular carcinogenesis in mice. Much of FGF19 activity is attributed to the activation of the liver enriched FGF Receptor 4 (FGFR4, although FGF19 can activate other FGFRs in vitro in the presence of the coreceptor βKlotho (KLB. In this report, we investigate the role of FGFR4 in mediating FGF19 activity by using Fgfr4 deficient mice as well as a variant of FGF19 protein (FGF19v which is specifically impaired in activating FGFR4. Our results demonstrate that FGFR4 activation mediates the induction of hepatocyte proliferation and the suppression of bile acid biosynthesis by FGF19, but is not essential for FGF19 to improve glucose and lipid metabolism in high fat diet fed mice as well as in leptin-deficient ob/ob mice. Thus, FGF19 acts through multiple receptor pathways to elicit pleiotropic effects in regulating nutrient metabolism and cell proliferation.

  20. FGF19 regulates cell proliferation, glucose and bile acid metabolism via FGFR4-dependent and independent pathways.

    Science.gov (United States)

    Wu, Ai-Luen; Coulter, Sally; Liddle, Christopher; Wong, Anne; Eastham-Anderson, Jeffrey; French, Dorothy M; Peterson, Andrew S; Sonoda, Junichiro

    2011-03-18

    Fibroblast growth factor 19 (FGF19) is a hormone-like protein that regulates carbohydrate, lipid and bile acid metabolism. At supra-physiological doses, FGF19 also increases hepatocyte proliferation and induces hepatocellular carcinogenesis in mice. Much of FGF19 activity is attributed to the activation of the liver enriched FGF Receptor 4 (FGFR4), although FGF19 can activate other FGFRs in vitro in the presence of the coreceptor βKlotho (KLB). In this report, we investigate the role of FGFR4 in mediating FGF19 activity by using Fgfr4 deficient mice as well as a variant of FGF19 protein (FGF19v) which is specifically impaired in activating FGFR4. Our results demonstrate that FGFR4 activation mediates the induction of hepatocyte proliferation and the suppression of bile acid biosynthesis by FGF19, but is not essential for FGF19 to improve glucose and lipid metabolism in high fat diet fed mice as well as in leptin-deficient ob/ob mice. Thus, FGF19 acts through multiple receptor pathways to elicit pleiotropic effects in regulating nutrient metabolism and cell proliferation.

  1. Correlation of glucose metabolism in brain cells and brain morphological changes with clinical typing in children with cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    Qiongxiang Zhai; Huixian Qiao; Jiqing Liu

    2006-01-01

    BACKGROUND:It is widely known that fluorino-18-fluorodeoxyglucose positron emission tomography(18F-FDG PET)is commonly used to evaluate and diagnose epilepsy;however,whether it is beneficial to understand functional metabolism of bra in cells so as to reflect injured site and degree of brain cells or not should be studied further.OBJECTIVE:To evaluate the correlation between glucose metabolism and clinical typling as well as the conelation between active function of brain cells and degree of brain injury among children with cerbral palsy with 18F-FDG PET and MRI and compare the results of them.DESIGN:Case analysis.SETTING:Department of Pediatrics,People's Hospital of Guangdong Province.PARTICIPANTS:A total of 31 children with cerebral palsy were selected from Out-patient Clinic and In-patient Department of People's Hospital of Guangdong Province from July 2001 to August 2004.Based on clinical criteria of cerebral palsy,patients were classified into spasm(n=10),gradual movement(n=4),mixed type(n =13)and ataxia(n=4).There were 18 boys and 13 girls aged from 10 months to 4 years.All of them were met the diagnostic criteria of cerebral palsy and all parents of them were told the facts.Exclusion cdteria:Patients who had cerebral palsy caused by genetic metabolism disease were excluded.METHODS:①All children accepted MRI examination after hospitalization with Philips Acs NT 15T superconductling magnetic resonance scanner.②All children were fasted for 4 hours.And then,PET image of brain was collected based on T+EID type.If obvious hypermetabolism or hypometabolism region successively occurred on two layers, the image was regarded as abnormality. ③Different correlations of various abnormal greups of MRI and vadous types of cerebral palsy with PET image were compared and analyzed with Erusal-Willas rank sum test.MAIN OUTCOME MEASURES:①Results of 18F-FDG PET;②Results of MRI examination;③Correlation of variously abnormal groups of MRI and various types of cerebral

  2. The malate-aspartate NADH shuttle member Aralar1 determines glucose metabolic fate, mitochondrial activity, and insulin secretion in beta cells.

    Science.gov (United States)

    Rubi, Blanca; del Arco, Araceli; Bartley, Clarissa; Satrustegui, Jorgina; Maechler, Pierre

    2004-12-31

    The NADH shuttle system, which transports reducing equivalents from the cytosol to the mitochondria, is essential for the coupling of glucose metabolism to insulin secretion in pancreatic beta cells. Aralar1 and citrin are two isoforms of the mitochondrial aspartate/glutamate carrier, one key constituent of the malate-aspartate NADH shuttle. Here, the effects of Aralar1 overexpression in INS-1E beta cells and isolated rat islets were investigated for the first time. We prepared a recombinant adenovirus encoding for human Aralar1 (AdCA-Aralar1), tagged with the small FLAG epitope. Transduction of INS-1E cells and isolated rat islets with AdCA-Aralar1 increased aralar1 protein levels and immunostaining revealed mitochondrial localization. Compared with control INS-1E cells, overexpression of Aralar1 potentiated metabolism secretion coupling stimulated by 15 mm glucose. In particular, there was an increase of NAD(P)H generation, of mitochondrial membrane hyperpolarization, ATP levels, glucose oxidation, and insulin secretion (+45%, p < 0.01). Remarkably, this was accompanied by reduced lactate production. Rat islets overexpressing Aralar1 secreted more insulin at 16.7 mm glucose (+65%, p < 0.05) compared with controls. These results show that aspartate-glutamate carrier capacity limits glucose-stimulated insulin secretion and that Aralar1 overexpression enhances mitochondrial metabolism.

  3. Gis1 and Rph1 regulate glycerol and acetate metabolism in glucose depleted yeast cells.

    Directory of Open Access Journals (Sweden)

    Jakub Orzechowski Westholm

    Full Text Available Aging in organisms as diverse as yeast, nematodes, and mammals is delayed by caloric restriction, an effect mediated by the nutrient sensing TOR, RAS/cAMP, and AKT/Sch9 pathways. The transcription factor Gis1 functions downstream of these pathways in extending the lifespan of nutrient restricted yeast cells, but the mechanisms involved are still poorly understood. We have used gene expression microarrays to study the targets of Gis1 and the related protein Rph1 in different growth phases. Our results show that Gis1 and Rph1 act both as repressors and activators, on overlapping sets of genes as well as on distinct targets. Interestingly, both the activities and the target specificities of Gis1 and Rph1 depend on the growth phase. Thus, both proteins are associated with repression during exponential growth, targeting genes with STRE or PDS motifs in their promoters. After the diauxic shift, both become involved in activation, with Gis1 acting primarily on genes with PDS motifs, and Rph1 on genes with STRE motifs. Significantly, Gis1 and Rph1 control a number of genes involved in acetate and glycerol formation, metabolites that have been implicated in aging. Furthermore, several genes involved in acetyl-CoA metabolism are downregulated by Gis1.

  4. High Glucose-Induced Oxidative Stress Mediates Apoptosis and Extracellular Matrix Metabolic Imbalances Possibly via p38 MAPK Activation in Rat Nucleus Pulposus Cells

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    Xiaofei Cheng

    2016-01-01

    Full Text Available Objectives. To investigate whether high glucose-induced oxidative stress is implicated in apoptosis of rat nucleus pulposus cells (NPCs and abnormal expression of critical genes involved in the metabolic balance of extracellular matrix (ECM. Methods. NPCs were cultured with various concentrations of glucose to detect cell viability and apoptosis. Cells cultured with high glucose (25 mM were untreated or pretreated with N-acetylcysteine or a p38 MAPK inhibitor SB 202190. Reactive oxygen species (ROS production was evaluated. Activation of p38 MAPK was measured by Western blot. The expression of ECM metabolism-related genes, including type II collagen, aggrecan, SRY-related high-mobility-group box 9 (Sox-9, matrix metalloproteinase 3 (MMP-3, and tissue inhibitor of metalloproteinase 1 (TIMP-1, was analyzed by semiquantitative RT-PCR. Results. High glucose reduced viability of NPCs and induced apoptosis. High glucose resulted in increased ROS generation and p38 MAPK activation. In addition, it negatively regulated the expression of type II collagen, aggrecan, Sox-9, and TIMP-1 and positively regulated MMP-3 expression. These results were changed by pretreatment with N-acetylcysteine or SB 202190. Conclusions. High glucose might promote apoptosis of NPCs, trigger ECM catabolic pathways, and inhibit its anabolic activities, possibly through a p38 MAPK-dependent oxidative stress mechanism.

  5. Intra- and intercellular mechanisms regulating glucose metabolism in the liver.

    NARCIS (Netherlands)

    E. Casteleijn (Eric)

    1988-01-01

    textabstractThe regulation of glucose metabolism in the liver by intraand intercellular mechanisms was studied. Fructose-1,6-bisphosphatase, an enzyme involved in de novo synthesis of glucose was found to be stimulated by glucagon in isolated parenchym~l liver cells. Glucagon increased the Vmax of f

  6. Glucose metabolism in injured tissue: A longitudinal study

    Energy Technology Data Exchange (ETDEWEB)

    Daley, J.M.; Shearer, J.D.; Mastrofrancesco, B.; Caldwell, M.D. (Brown Univ., Providence, RI (USA))

    1990-02-01

    Injured tissue is characterized by increased glucose uptake and increased lactate production as compared to normal tissue. These metabolic changes have been attributed to the presence of inflammatory cells in injured tissues. To correlate these metabolic changes with changes in the inflammatory cell population at various times after injury, we studied the lambda-carrageenan hindlimb wound model in anesthetized rats. Perfusion studies demonstrated that at 3 and 5 days after injury glucose uptake was increased in injured hindlimbs, compared with hindlimbs from pair-fed control animals. At 3, 5, and 10 days after injury, lactate production from glucose was increased in injured hindlimbs, compared with hindlimbs from pair-fed control animals. These metabolic changes were not related to differences in body weight or food intake. There was no difference in glucose oxidation or in oxygen consumption in injured hindlimbs, compared with hindlimbs from pair-fed control animals. The increased glucose uptake and increased lactate production from glucose was coincident with the presence of inflammatory cells--predominantly macrophages--at the site of injury. It is suggested that the glucose metabolism in injured tissue reflects the metabolism of the inflammatory cells at the site of injury.

  7. Defects in beta cell Ca2+ signalling, glucose metabolism and insulin secretion in a murine model of KATP channel-induced neonatal diabetes mellitus

    Science.gov (United States)

    Benninger, R. K. P.; Remedi, M. S.; Head, W. S.; Ustione, A.; Piston, D. W.; Nichols, C. G.

    2011-01-01

    Aims/hypothesis Mutations that render ATP-sensitive potassium (KATP) channels insensitive to ATP inhibition cause neonatal diabetes mellitus. In mice, these mutations cause insulin secretion to be lost initially and, as the disease progresses, beta cell mass and insulin content also disappear. We investigated whether defects in calcium signalling alone are sufficient to explain short-term and long-term islet dysfunction. Methods We examined the metabolic, electrical and insulin secretion response in islets from mice that become diabetic after induction of ATP-insensitive Kir6.2 expression. To separate direct effects of KATP overactivity on beta cell function from indirect effects of prolonged hyperglycaemia, normal glycaemia was maintained by protective exogenous islet transplantation. Results In endogenous islets from protected animals, glucose-dependent elevations of intracellular free-calcium activity ([Ca2+]i) were severely blunted. Insulin content of these islets was normal, and sulfonylureas and KCl stimulated increased [Ca2+]i. In the absence of transplant protection, [Ca2+]i responses were similar, but glucose metabolism and redox state were dramatically altered; sulfonylurea- and KCl-stimulated insulin secretion was also lost, because of systemic effects induced by long-term hyperglycaemia and/or hypoinsulinaemia. In both cases, [Ca2+]i dynamics were synchronous across the islet. After reduction of gap-junction coupling, glucose-dependent [Ca2+]i and insulin secretion was partially restored, indicating that excitability of weakly expressing cells is suppressed by cells expressing mutants, via gap-junctions. Conclusions/interpretation The primary defect in KATP-induced neonatal diabetes mellitus is failure of glucose metabolism to elevate [Ca2+]i, which suppresses insulin secretion and mildly alters islet glucose metabolism. Loss of insulin content and mitochondrial dysfunction are secondary to the long-term hyperglycaemia and/or hypoinsulinaemia that

  8. Increasing the culture efficiency of hybridoma cells by the use of integrated metabolic control of glucose and glutamine at low levels.

    Science.gov (United States)

    Li, Ling; Mi, Li; Feng, Qiang; Liu, Rong; Tang, Hao; Xie, Li; Yu, Xiaoling; Chen, Zhinan

    2005-08-01

    The metabolism of HAb18 hybridoma cells was shifted to decrease metabolite accumulation and to improve culture efficiency by integrated metabolic control of glucose and glutamine at low levels. When glucose and glutamine levels were decreased to 0.5 and 0.3 mM respectively, lactate and ammonia production were reduced by 62.6 and 74% respectively, glucose-to-cell yield was increased from 0.23x10(9) to 0.66x10(9) cells.mmol-1, and glutamine-to-cell yield from 0.18x10(9) to 1.95x10(9) cells.mmol-1. Compared with high-level glucose and glutamine fed-batch cultures, low-level glucose and glutamine led to higher cell density (1.0x10(7) versus 0.3x10(7) cells.ml-1), longer culture span (14 as opposed to 8 days) and higher antibody yield (250 as against 150 mg.l-1). These results indicate that hybridoma culture efficiency would be increased by the integrated control of glucose and glutamine at 0.5 and 0.3 mM respectively. In contrast with previously reported glucose-and/or-glutamine-level-controlled fed-batch cultures, we demonstrated an efficient strategy of nutrient level selection and amino acid feeding. More importantly, our accurately and well-distributed Equable Feeding Control System opens a new avenue for reducing metabolites to low levels by controlling nutrients at low levels.

  9. Twist promotes reprogramming of glucose metabolism in breast cancer cells through PI3K/AKT and p53 signaling pathways.

    Science.gov (United States)

    Yang, Li; Hou, Yixuan; Yuan, Jie; Tang, Shifu; Zhang, Hailong; Zhu, Qing; Du, Yan-e; Zhou, Mingli; Wen, Siyang; Xu, Liyun; Tang, Xi; Cui, Xiaojiang; Liu, Manran

    2015-09-22

    Twist, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in the development of a tumorigenic phenotype. Energy metabolism reprogramming (EMR), a newly discovered hallmark of cancer cells, potentiates cancer cell proliferation, survival, and invasion. Currently little is known about the effects of Twist on tumor EMR. In this study, we found that glucose consumption and lactate production were increased and mitochondrial mass was decreased in Twist-overexpressing MCF10A mammary epithelial cells compared with vector-expressing MCF10A cells. Moreover, these Twist-induced phenotypic changes were augmented by hypoxia. The expression of some glucose metabolism-related genes such as PKM2, LDHA, and G6PD was also found to be upregulated. Mechanistically, activated β1-integrin/FAK/PI3K/AKT/mTOR and suppressed P53 signaling were responsible for the observed EMR. Knockdown of Twist reversed the effects of Twist on EMR in Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Furthermore, blockage of the β1-integrin/FAK/PI3K/AKT/mTOR pathway by siRNA or specific chemical inhibitors, or rescue of p53 activation can partially reverse the switch of glucose metabolism and inhibit the migration of Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Thus, our data suggest that Twist promotes reprogramming of glucose metabolism in MCF10A-Twist cells and Twist-positive breast cancer cells via activation of the β1-integrin/FAK/PI3K/AKT/mTOR pathway and inhibition of the p53 pathway. Our study provides new insight into EMR.

  10. Keratin 8/18 regulation of glucose metabolism in normal versus cancerous hepatic cells through differential modulation of hexokinase status and insulin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Jasmin; Loranger, Anne; Gilbert, Stéphane [Centre de recherche en cancérologie de l' Université Laval and Centre de recherche du CHUQ (L' Hôtel-Dieu de Québec), 9 McMahon, Québec, Qc, Canada G1R 2J6 (Canada); Faure, Robert [Département de Pédiatrie, Université Laval and Centre de recherche du CHUQ (Centre Mère-Enfant), Québec, Qc, Canada G1V 4G2 (Canada); Marceau, Normand, E-mail: normand.marceau@crhdq.ulaval.ca [Centre de recherche en cancérologie de l' Université Laval and Centre de recherche du CHUQ (L' Hôtel-Dieu de Québec), 9 McMahon, Québec, Qc, Canada G1R 2J6 (Canada)

    2013-02-15

    As differentiated cells, hepatocytes primarily metabolize glucose for ATP production through oxidative phosphorylation of glycolytic pyruvate, whereas proliferative hepatocellular carcinoma (HCC) cells undergo a metabolic shift to aerobic glycolysis despite oxygen availability. Keratins, the intermediate filament (IF) proteins of epithelial cells, are expressed as pairs in a lineage/differentiation manner. Hepatocyte and HCC (hepatoma) cell IFs are made solely of keratins 8/18 (K8/K18), thus providing models of choice to address K8/K18 IF functions in normal and cancerous epithelial cells. Here, we demonstrate distinctive increases in glucose uptake, glucose-6-phosphate formation, lactate release, and glycogen formation in K8/K18 IF-lacking hepatocytes and/or hepatoma cells versus their respective IF-containing counterparts. We also show that the K8/K18-dependent glucose uptake/G6P formation is linked to alterations in hexokinase I/II/IV content and localization at mitochondria, with little effect on GLUT1 status. In addition, we find that the insulin-stimulated glycogen formation in normal hepatocytes involves the main PI-3 kinase-dependent signaling pathway and that the K8/K18 IF loss makes them more efficient glycogen producers. In comparison, the higher insulin-dependent glycogen formation in K8/K18 IF-lacking hepatoma cells is associated with a signaling occurring through a mTOR-dependent pathway, along with an augmentation in cell proliferative activity. Together, the results uncover a key K8/K18 regulation of glucose metabolism in normal and cancerous hepatic cells through differential modulations of mitochondrial HK status and insulin-mediated signaling.

  11. Visfatin, glucose metabolism and vascular disease: a review of evidence

    Directory of Open Access Journals (Sweden)

    Saddi-Rosa Pedro

    2010-03-01

    Full Text Available Abstract The adipose tissue is an endocrine organ producing substances called adipocytokines that have different effects on lipid metabolism, metabolic syndrome, and cardiovascular risk. Visfatin was recently described as an adipocytokine with potentially important effects on glucose metabolism and atherosclerosis. Visfatin has been linked to several inflammatory conditions, beta cell function, and cardiovascular disease. The growing number of publications on the subject shall bring further evidence about this adipocytokine. Its findings may contribute in the identification of higher risk individuals for diabetes and cardiovascular disease with a better comprehension about the complex intercorrelation between adiposity, glucose metabolism and vascular disease.

  12. [THE OPTIMIZATION OF NUTRITION FUNCTION UNDER SYNDROME OF RESISTANCE TO INSULIN, DISORDER OF FATTY ACIDS' METABOLISM AND ABSORPTION OF GLUCOSE BY CELLS (A LECTURE)].

    Science.gov (United States)

    Titov, V N

    2016-01-01

    The phylogenetic processes continue to proceed in Homo Sapiens. At the very early stages ofphylogenesis, the ancient Archaea that formed mitochondria under symbiotic interaction with later bacterial cells conjointly formed yet another system. In this system, there are no cells' absorption of glucose if it is possible to absorb fatty acids from intercellular medium in the form of unesterfied fatty acids or ketonic bodies--metabolites of fatty acids. This is caused by objectively existed conditions and subsequent availability of substrates at the stages ofphylogenesis: acetate, ketonic bodies, fatty acids and only later glucose. The phylogenetically late insulin used after billions years the same dependencies at formation of regulation ofmetabolism offatty acids and cells' absorption of glucose. In order that syndrome ofresistance ceased to exist as afoundation of metabolic pandemic Homo Sapiens has to understand the following. After successful function ofArchaea+bacterial cells and considered by biology action of insulin for the third time in phylogenesis and using biological function of intelligence the content ofphylogenetically earlier palmitic saturated fatty acid infood can't to exceed possibilities of phylogenetically late lipoproteins to transfer it in intercellular medium and blood and cells to absorb it. It is supposed that at early stages of phylogenesis biological function of intelligence is primarily formed to bring into line "unconformities" of regulation of metabolism against the background of seeming relative biological "perfection". These unconformities were subsequently and separately formed at the level of cells in paracrin regulated cenosises of cells and organs and at the level of organism. The prevention of resistance to insulin basically requires biological function of intelligence, principle of self-restraint, bringing into line multiple desires of Homo Sapiens with much less extensive biological possibilities. The "unconformities" of

  13. The human hepatocyte cell lines IHH and HepaRG : models to study glucose, lipid and lipoprotein metabolism

    NARCIS (Netherlands)

    Samanez, Carolina Huaman; Caron, Sandrine; Briand, Olivier; Dehondt, Helene; Duplan, Isabelle; Kuipers, Folkert; Hennuyer, Nathalie; Clavey, Veronique; Staels, Bart

    2012-01-01

    Metabolic diseases reach epidemic proportions. A better knowledge of the associated alterations in the metabolic pathways in the liver is necessary. These studies need in vitro human cell models. Several human hepatoma models are used, but the response of many metabolic pathways to physiological sti

  14. Defective glucose and lipid metabolism in human immunodeficiency virus-infected patients with lipodystrophy involve liver, muscle tissue and pancreatic beta-cells

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Dela, Flemming

    2005-01-01

    OBJECTIVES: Lipodystrophy and insulin resistance are prevalent among human immunodeficiency virus (HIV)-infected patients on combined antiretroviral therapy (HAART). Aiming to provide a detailed description of the metabolic adverse effects of HIV-lipodystrophy, we investigated several aspects...... acids (P combined study groups, RLF correlated with hepatic insulin sensitivity (r = 0.69), incremental glucose disposal (r = 0.71) and incremental exogenous glucose storage (r = 0.40), all P ....01. Disposition index (i.e. first-phase insulin response to intravenous glucose multiplied by incremental glucose disposal) was reduced by 46% (P = 0.05) in LIPO compared with the combined groups of NONLIPO and NAIVE, indicating an impaired adaptation of beta-cell function to insulin resistance in LIPO...

  15. Repressing malic enzyme 1 redirects glucose metabolism,unbalances the redox state, and attenuates migratory and invasive abilities in nasopharyngeal carcinoma cell lines

    Institute of Scientific and Technical Information of China (English)

    Fang-Jing Zheng; Hao-Bin Ye; Man-Si Wu; Yi-Fan Lian; Chao-Nan Qian; Yi-Xin Zeng

    2012-01-01

    A large amount of nicotinamide adenine dinucleotide phosphate (NADPH) is required for fatty acid synthesis and maintenance of the redox state in cancer cells.Malic enzyme 1 (ME1)-dependent NADPH production is one of the three pathways that contribute to the formation of the cytosolic NADPH pool.ME1 is generally considered to be overexpressed in cancer cells to meet the high demand for increased de novo fatty acid synthesis.In the present study,we found that glucose induced higher ME1 activity and that repressing ME1 had a profound impact on glucose metabolism of nasopharyngeal carcinoma (NPC) cells.High incorporation of glucose and an enhancement of the pentose phosphate pathway were observed in ME1-repressed cells.However,there were no obvious changes in the other two pathways for glucose metabolism:glycolysis and oxidative phosphorylation.Interestingly,NADPH was decreased under lowglucose condition in ME1-repressed cells relative to wild-type cells,whereas no significant difference was observed under high-glucose condition.ME1-repressed cells had significantly decreased tolerance to lowglucose condition.Moreover,NADPH produced by ME1 was not only important for fatty acid synthesis but also essential for maintenance of the intracellular redox state and the protection of cells from oxidative stress.Furthermore,diminished migration and invasion were observed in ME1-repressed cells due to a reduced level of Snail protein.Collectively,these results suggest an essential role for ME1 in the production of cytosolic NADPH and maintenance of migratory and invasive abilities of NPC cells.

  16. Glucose Metabolism Disorders, HIV and Antiretroviral Therapy among Tanzanian Adults.

    Directory of Open Access Journals (Sweden)

    Emmanuel Maganga

    Full Text Available Millions of HIV-infected Africans are living longer due to long-term antiretroviral therapy (ART, yet little is known about glucose metabolism disorders in this group. We aimed to compare the prevalence of glucose metabolism disorders among HIV-infected adults on long-term ART to ART-naïve adults and HIV-negative controls, hypothesizing that the odds of glucose metabolism disorders would be 2-fold greater even after adjusting for possible confounders.In this cross-sectional study conducted between October 2012 and April 2013, consecutive adults (>18 years attending an HIV clinic in Tanzania were enrolled in 3 groups: 153 HIV-negative controls, 151 HIV-infected, ART-naïve, and 150 HIV-infected on ART for ≥ 2 years. The primary outcome was the prevalence of glucose metabolism disorders as determined by oral glucose tolerance testing. We compared glucose metabolism disorder prevalence between each HIV group vs. the control group by Fisher's exact test and used multivariable logistic regression to determine factors associated with glucose metabolism disorders.HIV-infected adults on ART had a higher prevalence of glucose metabolism disorders (49/150 (32.7% vs.11/153 (7.2%, p<0.001 and frank diabetes mellitus (27/150 (18.0% vs. 8/153 (5.2%, p = 0.001 than HIV-negative adults, which remained highly significant even after adjusting for age, gender, adiposity and socioeconomic status (OR = 5.72 (2.78-11.77, p<0.001. Glucose metabolism disorders were significantly associated with higher CD4+ T-cell counts. Awareness of diabetes mellitus was <25%.HIV-infected adults on long-term ART had 5-fold greater odds of glucose metabolism disorders than HIV-negative controls but were rarely aware of their diagnosis. Intensive glucose metabolism disorder screening and education are needed in HIV clinics in sub-Saharan Africa. Further research should determine how glucose metabolism disorders might be related to immune reconstitution.

  17. Glucose metabolism in cultured trophoblasts from human placenta

    Energy Technology Data Exchange (ETDEWEB)

    Moe, A.J.; Farmer, D.R.; Nelson, D.M.; Smith, C.H. (Washington Univ., St. Louis, MO (United States))

    1990-02-26

    The development of appropriate placental trophoblast isolation and culture techniques enables the study of pathways of glucose utilization by this important cell layer in vitro. Trophoblasts from normal term placentas were isolated and cultured 24 hours and 72 hours in uncoated polystyrene culture tubes or tubes previously coated with a fibrin matrix. Trophoblasts cultured on fibrin are morphologically distinct from those cultured on plastic or other matrices and generally resemble in vivo syncytium. Cells were incubated up to 3 hours with {sup 14}C-labeled glucose and reactions were stopped by addition of perchloric acid. {sup 14}CO{sub 2} production by trophoblasts increased linearly with time however the largest accumulation of label was in organic acids. Trophoblasts cultured in absence of fibrin utilized more glucose and accumulated more {sup 14}C in metabolic products compared to cells cultured on fibrin. Glucose oxidation to CO{sub 2} by the phosphogluconate (PG) pathway was estimated from specific yields of {sup 14}CO{sub 2} from (1-{sup 14}C)-D-glucose and (6-{sup 14}C)-D-glucose. Approximately 6% of glucose oxidation was by the PG pathway when cells were cultured on fibrin compared to approximately 1% by cells cultured in the absence of fibrin. The presence of a fibrin growth matrix appears to modulate the metabolism of glucose by trophoblast from human placenta in vitro.

  18. c-Myc modulates glucose metabolism via regulation of miR-184/PKM2 pathway in clear-cell renal cell carcinoma.

    Science.gov (United States)

    Huang, Jiwei; Kong, Wen; Zhang, Jin; Chen, Yonghui; Xue, Wei; Liu, Dongming; Huang, Yiran

    2016-10-01

    Renal cell carcinoma (RCC) is one of the most malignant tumors worldwide. Among all subtypes of RCC, clear-cell RCC (ccRCC) is the most common and aggressive one. The difficulty in overcoming resistance of traditional treatment is a threat for ccRCC therapies. Therefore, to understand the mechanism that underlies ccRCC progression is critical for new drug development. In the present study, we identified that miR-184 could be downregulated by c-Myc, which is different from the standard opinion that c-Myc is a target of miR-184. Overexpression of pre-miR-184 changed the metabolic and proliferation features of ccRCC cells by reducing cell glucose consumption, lactate production and cell proliferation. Further analysis by computer bioinformatics revealed that PKM2 is a target of miR-184. Both PKM2 mRNA and protein were significantly affected by addition of miR-184. Importantly, the PKM2 expression level was indeed increased in ccRCC samples, which is totally reverse compared to the decreased miR-184 expression level. Interestingly, we found that when PKM2 was knocked down in ccRCC cells, the rapid proliferation, high glucose consumption and high lactate production were all clearly inhibited, which indicates metabolic reprogramming and cancer progression blocking the in ccRCC cells. Our findings shed new light on ccRCC molecular study and provide a new and solid basis for developing ccRCC therapy.

  19. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian

    2015-01-01

    and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards...... optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylationrelated product quality. In this work, different fed-batch processes with two chemically defined proprietary media...

  20. Rosemary (Rosmarinus officinalis L.) extract regulates glucose and lipid metabolism by activating AMPK and PPAR pathways in HepG2 cells.

    Science.gov (United States)

    Tu, Zheng; Moss-Pierce, Tijuana; Ford, Paul; Jiang, T Alan

    2013-03-20

    An epidemic of metabolic disorders such as obesity and diabetes is rising dramatically. Using natural products as potential preventive and therapeutic interventions for these disorders has drawn worldwide attention. Rosemary has been shown to lower blood glucose and cholesterol levels and mitigate weight gain in several in vivo studies. However, the mechanisms are essentially unknown. We investigated the effects of rosemary extract on metabolism and demonstrated that rosemary extract significantly increased glucose consumption in HepG2 cells. The phosphorylation of AMP-activated protein kinase (AMPK) and its substrate, acetyl-CoA carboxylase (ACC), was increased by rosemary extract. Rosemary extract also transcriptionally regulated the genes involved in metabolism, including SIRT1, PPARγ coactivator 1α (PGC1α), glucose-6-phosphatase (G6Pase), ACC, and low-density lipoprotein receptor (LDLR). Furthermore, the PPARγ-specific antagonist GW9662 diminished rosemary's effects on glucose consumption. Overall, our study suggested that rosemary potentially increases liver glycolysis and fatty acid oxidation by activating AMPK and PPAR pathways.

  1. Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: A role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ajay; Kant, Shiva; Singh, Sukh Mahendra, E-mail: sukhmahendrasingh@yahoo.com

    2013-11-15

    Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment.

  2. The MDM2–p53–pyruvate carboxylase signalling axis couples mitochondrial metabolism to glucose-stimulated insulin secretion in pancreatic β-cells

    Science.gov (United States)

    Li, Xiaomu; Cheng, Kenneth K. Y.; Liu, Zhuohao; Yang, Jin-Kui; Wang, Baile; Jiang, Xue; Zhou, Yawen; Hallenborg, Philip; Hoo, Ruby L. C.; Lam, Karen S. L.; Ikeda, Yasuhiro; Gao, Xin; Xu, Aimin

    2016-01-01

    Mitochondrial metabolism is pivotal for glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells. However, little is known about the molecular machinery that controls the homeostasis of intermediary metabolites in mitochondria. Here we show that the activation of p53 in β-cells, by genetic deletion or pharmacological inhibition of its negative regulator MDM2, impairs GSIS, leading to glucose intolerance in mice. Mechanistically, p53 activation represses the expression of the mitochondrial enzyme pyruvate carboxylase (PC), resulting in diminished production of the TCA cycle intermediates oxaloacetate and NADPH, and impaired oxygen consumption. The defective GSIS and mitochondrial metabolism in MDM2-null islets can be rescued by restoring PC expression. Under diabetogenic conditions, MDM2 and p53 are upregulated, whereas PC is reduced in mouse β-cells. Pharmacological inhibition of p53 alleviates defective GSIS in diabetic islets by restoring PC expression. Thus, the MDM2–p53–PC signalling axis links mitochondrial metabolism to insulin secretion and glucose homeostasis, and could represent a therapeutic target in diabetes. PMID:27265727

  3. Glucose metabolism in rat retinal pigment epithelium.

    Science.gov (United States)

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress.

  4. The Compound of Mangiferin-Berberine Salt Has Potent Activities in Modulating Lipid and Glucose Metabolisms in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Can Wang

    2016-01-01

    Full Text Available The mangiferin-berberine (MB salt was synthesized by ionic bonding of mangiferin (M and berberine (B at an equal molecular ratio. This study aimed to investigate the activities of MB salt in modulating lipid and glucose metabolisms in HepG2 cells. After 24 h treatment of the studying compounds, cellular AMP-activated protein kinase α (AMPKα/acetyl-CoA carboxylase (ACC protein levels and carnitine palmitoyltransferase (CPT 1 activities, intracellular lipid contents, mRNA expression levels of target genes, glucose consumption, and glucose production amounts were determined. Compound C (CC was used in the blocking experiments. Our results showed that MB salt increased p-AMPKα (Thr172/p-ACC (Ser79 levels and CPT1 activity and suppressed oleic acid- (OA- induced lipid accumulation and upregulation of lipogenic genes potently in HepG2 cells. The above activities of MB salt were AMPK dependent and were superior to those of M or B when administered at an equal molar concentration. MB salt enhanced basal and insulin-stimulated glucose consumption and suppressed gluconeogenesis more potently than M or B alone. The inhibiting activity of MB salt on cellular gluconeogenesis was AMPK dependent. Our results may support MB salt as a new kind of agent for the development of novel lipid or glucose-lowering drugs in the future.

  5. The Compound of Mangiferin-Berberine Salt Has Potent Activities in Modulating Lipid and Glucose Metabolisms in HepG2 Cells.

    Science.gov (United States)

    Wang, Can; Jiang, Jian-Dong; Wu, Wei; Kong, Wei-Jia

    2016-01-01

    The mangiferin-berberine (MB) salt was synthesized by ionic bonding of mangiferin (M) and berberine (B) at an equal molecular ratio. This study aimed to investigate the activities of MB salt in modulating lipid and glucose metabolisms in HepG2 cells. After 24 h treatment of the studying compounds, cellular AMP-activated protein kinase α (AMPKα)/acetyl-CoA carboxylase (ACC) protein levels and carnitine palmitoyltransferase (CPT) 1 activities, intracellular lipid contents, mRNA expression levels of target genes, glucose consumption, and glucose production amounts were determined. Compound C (CC) was used in the blocking experiments. Our results showed that MB salt increased p-AMPKα (Thr172)/p-ACC (Ser79) levels and CPT1 activity and suppressed oleic acid- (OA-) induced lipid accumulation and upregulation of lipogenic genes potently in HepG2 cells. The above activities of MB salt were AMPK dependent and were superior to those of M or B when administered at an equal molar concentration. MB salt enhanced basal and insulin-stimulated glucose consumption and suppressed gluconeogenesis more potently than M or B alone. The inhibiting activity of MB salt on cellular gluconeogenesis was AMPK dependent. Our results may support MB salt as a new kind of agent for the development of novel lipid or glucose-lowering drugs in the future.

  6. Tumor cell metabolism

    Science.gov (United States)

    Romero-Garcia, Susana; Lopez-Gonzalez, Jose Sullivan; B´ez-Viveros, José Luis; Aguilar-Cazares, Dolores

    2011-01-01

    Cancer is a genetic disease that is caused by mutations in oncogenes, tumor suppressor genes and stability genes. The fact that the metabolism of tumor cells is altered has been known for many years. However, the mechanisms and consequences of metabolic reprogramming have just begun to be understood. In this review, an integral view of tumor cell metabolism is presented, showing how metabolic pathways are reprogrammed to satisfy tumor cell proliferation and survival requirements. In tumor cells, glycolysis is strongly enhanced to fulfill the high ATP demands of these cells; glucose carbons are the main building blocks in fatty acid and nucleotide biosynthesis. Glutaminolysis is also increased to satisfy NADPH regeneration, whereas glutamine carbons replenish the Krebs cycle, which produces metabolites that are constantly used for macromolecular biosynthesis. A characteristic feature of the tumor microenvironment is acidosis, which results from the local increase in lactic acid production by tumor cells. This phenomenon is attributed to the carbons from glutamine and glucose, which are also used for lactic acid production. Lactic acidosis also directs the metabolic reprogramming of tumor cells and serves as an additional selective pressure. Finally, we also discuss the role of mitochondria in supporting tumor cell metabolism. PMID:22057267

  7. Effect of 2-deoxy-D-glucose on DNA double strand break repair, cell survival and energy metabolism in euoxic Ehrlich ascites tumour cells

    Energy Technology Data Exchange (ETDEWEB)

    Jha, B.; Pohlit, W. (L.N. Mithila Univ., Darbhanga (India). Botany Dept.)

    1992-10-01

    Effects of 2-deoxy-D-glucose (2-DG) on DNA double strand break (dsb) repair, cell survival and on the energy metabolism were investigated in exponentially growing Ehrlich ascites tumour (EAT) cells. Cells in suspension were exposed to 40 Gy of X-rays and allowed to repair (up to 4h) with or without 2-DG at 37[sup o]C. DNA dsb rejoining was measured by means of clamped homogeneous electric field (CHEF), a pulsed field gel electrophoresis technique. The fraction of activity released (FAR) during electrophoresis (DNA associated [sup 14]C-thymidine) was used as a parameter to determine the number of dsb present in the DNA. Biphasic kinetics for dsb repair were observed. The presence of 2-DG significantly inhibited the slow component of dsb repair. The presence of 2-DG also enhanced radiation-induced cell killing. ATP content of cells was measured by a bioluminescence method. ATP content in exponentially growing cells was about 4 pg per cell. The level of ATP was reduced by 50% in presence of 2-DG (C[sub 2-DG]/C[sub G] = 1.0). (author).

  8. Glucose metabolism is altered after loss of L cells and α-cells but not influenced by loss of K cells

    DEFF Research Database (Denmark)

    Pedersen, J; Ugleholdt, Randi Kjærsgaard; Jørgensen, Signe Marie;

    2013-01-01

    The enteroendocrine K and L cells are responsible for secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon like-peptide 1 (GLP-1), whereas pancreatic α-cells are responsible for secretion of glucagon. In rodents and humans, dysregulation of the secretion of GIP, GLP-1, and...

  9. Alteration of hepatic cells glucose metabolism as a non-cholinergic detoxication mechanism in counteracting diazinon-induced oxidative stress.

    Science.gov (United States)

    Teimouri, Fatemeh; Amirkabirian, Nasim; Esmaily, Hadi; Mohammadirad, Azadeh; Aliahmadi, Atousa; Abdollahi, Mohammad

    2006-12-01

    The aim of this study was to evaluate effects of acute exposure to various doses of diazinon, a widely used synthetic organophosphorus (OP) insecticide on plasma glucose, hepatic cells key enzymes of glycogenolysis and gluconeogenesis, and oxidative stress in rats. Diazinon was administered by gavage at doses of 15, 30 and 60 mg/ kg. The liver was perfused and removed under anaesthesia. The activities of glycogen phosphorylase (GP), phosphoenolpyruvate carboxykinase (PEPCK), thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) were analysed in liver homogenate. Administration of diazinon (15, 30 and 60 mg/kg) increased plasma glucose concentrations by 101.43% (P = 0.001), 103.68% (P = 0.000) and 160.65% (P = 0.000) of control, respectively. Diazinon (15, 30 and 60 mg/kg) increased hepatic GP activity by 43.5% (P = 0.05), 70.3% (P = 0.00) and 117.2% (P = 0.02) of control, respectively. In addition, diazinon (30 and 60 mg/kg) increased hepatic PEPCK by 77.3% (P = 0.000) and 93.5% (P = 0.000) of control, respectively. Diazinon (30 and 60 mg/kg) decreased liver TAC by 38% (P = 0.046) and 48% (P = 0.000) of control, respectively. Also diazinon (30 and 60 mg/kg) increased hepatic cell liver lipid peroxidation by 77% (P = 0.05) and 280% (P = 0.000) of control. The correlations between plasma glucose and hepatic cells TBARS (r2 = 0.537, P = 0.02), between plasma glucose and ChE activity (r2 = 0.81, P = 0.049) and between plasma glucose and hepatic cells GP activity (r2 = 0.833, P = 0.04) were significant. It is concluded that the liver cells are a site of toxic action of diazinon. Diazinon increases glucose release from liver into blood through activation of glycogenolysis and gluconeogenesis as a detoxication non-cholinergic mechanism to overwhelm diazinon-induced toxic stress. The results are in accordance with the hypothesis that OPs are a predisposing factor of diabetes.

  10. Glucose and galactose metabolism in Gluconabacter liquefaciens

    NARCIS (Netherlands)

    Stouthamer, A.H.

    1961-01-01

    Glucose-grown cells of Gluconobacter liquefaciens oxidize glucose, gluconate and 2-ketogluconate practically completely to 2,5-diketogluconate by particulate enzymes, localized in the protoplasmic membrane. The bulk of the 2,5-diketgluconate (and 5-ketogluconate) enters the cytoplasm and is metaboli

  11. Mathematical model of metabolism and electrophysiology of amino acid and glucose stimulated insulin secretion: in vitro validation using a β-cell line.

    Directory of Open Access Journals (Sweden)

    Manuela Salvucci

    Full Text Available We integrated biological experimental data with mathematical modelling to gain insights into the role played by L-alanine in amino acid-stimulated insulin secretion (AASIS and in D-glucose-stimulated insulin secretion (GSIS, details important to the understanding of complex β-cell metabolic coupling relationships. We present an ordinary differential equations (ODEs based simplified kinetic model of core metabolic processes leading to ATP production (glycolysis, TCA cycle, L-alanine-specific reactions, respiratory chain, ATPase and proton leak and Ca(2+ handling (essential channels and pumps in the plasma membrane in pancreatic β-cells and relate these to insulin secretion. Experimental work was performed using a clonal rat insulin-secreting cell line (BRIN-BD11 to measure the consumption or production of a range of important biochemical parameters (D-glucose, L-alanine, ATP, insulin secretion and Ca(2+ levels. These measurements were then used to validate the theoretical model and fine-tune the parameters. Mathematical modelling was used to predict L-lactate and L-glutamate concentrations following D-glucose and/or L-alanine challenge and Ca(2+ levels upon stimulation with a non metabolizable L-alanine analogue. Experimental data and mathematical model simulations combined suggest that L-alanine produces a potent insulinotropic effect via both a stimulatory impact on β-cell metabolism and as a direct result of the membrane depolarization due to Ca(2+ influx triggered by L-alanine/Na(+ co-transport. Our simulations indicate that both high intracellular ATP and Ca(2+ concentrations are required in order to develop full insulin secretory responses. The model confirmed that K(+ ATP channel independent mechanisms of stimulation of intracellular Ca(2+ levels, via generation of mitochondrial coupling messengers, are essential for promotion of the full and sustained insulin secretion response in β-cells.

  12. HDL and glucose metabolism: current evidence and therapeutic potential.

    Science.gov (United States)

    Siebel, Andrew L; Heywood, Sarah Elizabeth; Kingwell, Bronwyn A

    2015-01-01

    High-density lipoprotein (HDL) and its principal apolipoprotein A-I (ApoA-I) have now been convincingly shown to influence glucose metabolism through multiple mechanisms. The key clinically relevant observations are that both acute HDL elevation via short-term reconstituted HDL (rHDL) infusion and chronically raising HDL via a cholesteryl ester transfer protein (CETP) inhibitor reduce blood glucose in individuals with type 2 diabetes mellitus (T2DM). HDL may mediate effects on glucose metabolism through actions in multiple organs (e.g., pancreas, skeletal muscle, heart, adipose, liver, brain) by three distinct mechanisms: (i) Insulin secretion from pancreatic beta cells, (ii) Insulin-independent glucose uptake, (iii) Insulin sensitivity. The molecular mechanisms appear to involve both direct HDL signaling actions as well as effects secondary to lipid removal from cells. The implications of glucoregulatory mechanisms linked to HDL extend from glycemic control to potential anti-ischemic actions via increased tissue glucose uptake and utilization. Such effects not only have implications for the prevention and management of diabetes, but also for ischemic vascular diseases including angina pectoris, intermittent claudication, cerebral ischemia and even some forms of dementia. This review will discuss the growing evidence for a role of HDL in glucose metabolism and outline related potential for HDL therapies.

  13. Perturbed glucose metabolism: insights into Multiple Sclerosis pathogenesis

    Directory of Open Access Journals (Sweden)

    Deepali eMathur

    2014-12-01

    Full Text Available Multiple sclerosis (MS is a complex debilitating disease of the central nervous system perceived to result from the autoimmune effect of T cells in damaging myelin sheath. However, the exact pathogenesis of the disease remains elusive. Initial studies describing the possibility of defective pyruvate metabolism in MS were performed in 1950s. The group observed elevated blood pyruvate level in both fasting and postprandial times in MS patients with relapse. Similarly, other investigators also reported increased fasting pyruvate level in this disease. These reports hint to a possible abnormality of pyruvate metabolism in MS patients. In addition, increase in levels of Krebs cycle acids like alpha-ketoglutarate in fasting and citrate after glucose intake in MS patients further strengthened the connection of disturbed pyruvate metabolism with MS progression. These studies led the investigators to explore the role of disturbed glucose metabolism in pathophysiological brain function. Under normal circumstances, complex molecules are metabolized into simpler molecules through their respective pathways. Differential expression of genes encoding enzymes of the glucose metabolic pathway in central nervous system (CNS may result in neurological deficits. In this review article, we discussed the studies related to disturbed carbohydrate metabolism in MS and other neurodegenerative diseases. These observations open new perspectives for the understanding of metabolic dynamics in multiple sclerosis yet many puzzling aspects and critical questions need to be addressed. Much more research is required to fully unravel the disease mechanism, and a proper understanding of the disease could eventually lead to new treatments.

  14. Circadian control of glucose metabolism

    NARCIS (Netherlands)

    Kalsbeek, A.; la Fleur, Susanne; Fliers, Eric

    2014-01-01

    The incidence of obesity and type 2 diabetes mellitus (T2DM) has risen to epidemic proportions. The pathophysiology of T2DM is complex and involves insulin resistance, pancreatic β-cell dysfunction and visceral adiposity. It has been known for decades that a disruption of biological rhythms (which h

  15. Preferential Transport and Metabolism of Glucose in Bergmann Glia over Purkinje Cells: A Multiphoton Study of Cerebellar Slices

    Institute of Scientific and Technical Information of China (English)

    L.F.BARROS; R.COURJARET; P.JAKOBY; A.LOAIZA; C.LOHR; J.W.DEITMER

    2009-01-01

    了解不同类型的细胞如何处理葡萄糖有助于解释能量供应是如何是如何根据大脑能量需求来进行调整的.荧光追踪结合共聚焦显微镜技术已用于研究培养的脑细胞摄取葡萄糖的实时动态过程.本文采用这种技术利用多光子显微镜观察急性制备的大鼠小脑脑片.带荧光的葡萄糖类似物2NBDG和6NBDG在小脑皮质的分子层中的转运速度比其在蒲肯野细胞胞体和颗粒细胞中快若干倍.洗脱游离示踪剂后,可见大部分磷酸化示踪剂都位于Bergmann胶质细胞,用胶质细胞标记物sulforhodamine 101免疫染色后进一步确认这一结果.有效回收荧光光漂白后显示,2NBDG-P可通过Bergmann胶质细胞之间的缝隙连接沿着分子层水平扩散.本文的结果表明在急性小脑切片中,Bergmann胶质细胞对葡萄糖的转运能力和糖酵解率高于蒲肯野细胞若干倍.由于小脑主要由葡萄糖提供能量,蒲肯野神经元被认为比Bergmann胶质细胞更耗能量,这些结果表明,在胶质细胞和神经元之间存在类似乳酸的能量代谢物介导的环路.%Knowing how different cell types handle glucose should help to decipher how energy supply is adjusted to energy demand in the brain. Previously, the uptake of glucose by cultured brain cells was studied in real-time using fluorescent tracers and confocal microscopy. Here, we have adapted this technique to acute slices prepared from the rat cerebellum by means of multiphoton microscopy. The transport of the fluorescent glucose analogs 2NBDG and 6NBDG was several-fold faster in the molecular layer of the cerebellar cortex than in Purkinje cell somata and granule cells. After washout of free tracer, it became apparent that most phosphorylated tracer was located in Bergmann glia, which was confirmed by counterstaining with the glial marker sulforhodamine 101. The effective recovery of fluorescence after photobleaching showed that 2NBDG-P can diffuse

  16. Steroid receptor coactivator-3 regulates glucose metabolism in bladder cancer cells through coactivation of hypoxia inducible factor 1α.

    Science.gov (United States)

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-04-18

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as "Warburg effect," to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy.

  17. Osteocalcin as a hormone regulating glucose metabolism

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The number of patients with osteoporosis and diabetesis rapidly increasing all over the world. Bone is recentlyrecognized as an endocrine organ. Accumulatingevidence has shown that osteocalcin, which is specificallyexpressed in osteoblasts and secreted into the circulation,regulates glucose homeostasis by stimulating insulinexpression in pancreas and adiponectin expression inadipocytes, resulting in improving glucose intolerance.On the other hand, insulin and adiponectin stimulateosteocalcin expression in osteoblasts, suggesting thatpositive feedforward loops exist among bone, pancreas,and adipose tissue. In addition, recent studies haveshown that osteocalcin enhances insulin sensitivity andthe differentiation in muscle, while secreted factors frommuscle, myokines, regulate bone metabolism. Thesefindings suggest that bone metabolism and glucosemetabolism are associated with each other through theaction of osteocalcin. In this review, I describe the roleof osteocalcin in the interaction among bone, pancreas,brain, adipose tissue, and muscle.

  18. 癌细胞葡萄糖代谢重编程的分子基础%Molecular basis of glucose metabolic reprogramming in cancer cells

    Institute of Scientific and Technical Information of China (English)

    赵世光

    2014-01-01

    代谢的重编程是癌细胞的基本特征之一,其中葡萄糖代谢方式和途径的改变对癌症的发生和发展至关重要。即使在氧气足够充足的情况下,快速增殖的癌细胞生长所需的能量主要由糖酵解而非氧化磷酸化提供,癌细胞这种特殊的糖代谢现象被称为Warburg效应。这种特有的能量获取方式已在多种癌细胞中得到验证,以癌细胞对葡萄糖高摄取率和利用增加为原理的18F-FDG PET/CT显像已广泛应用于临床的癌症诊断。但癌细胞为何利用有氧酵解获取能量以及有氧酵解进行的分子基础目前尚不明确,本文围绕调控癌细胞糖酵解进程中的直接调控酶、癌基因及致癌代谢小分子进行分析和综述。%Cancer metabolic reprogramming is among the basic characteristics of cancer cells. Changes in glucose metabolism are essential for carcinogenesis and cancer development. Previous study indicated that energy is acquired mainly via glycolysis rather than oxidative phosphorylation in the presence of sufficient oxygen levels to promote the rapid proliferation of cells, such as cancer cells. This phenomenon is called the"Warburg effect."Furthermore, this unique approach of energy production in cancer cells has been validated in various types of cancer cells. On the basis of the characteristics of cancer cells with high glucose uptake and utilization, cli-nicians and medical practitioners extensively apply 18-fludeoxyglucose positron emission tomography in clinical diagnosis. Tumor cells undergo aerobic glycolysis to produce energy, but this metabolic pathway is poorly efficient;the molecular basis of aerobic glycol-ysis and the reason for these cells to undergo this metabolic pathway also remain unclear. In this article, glycolysis-related processes, in-cluding enzyme, oncogene, and oncometabolite regulation, in cancer cells are summarized.

  19. Biosynthesis of highly enriched 13C-lycopene for human metabolic studies using repeated batch tomato cell culturing with 13C-glucose.

    Science.gov (United States)

    Moran, Nancy Engelmann; Rogers, Randy B; Lu, Chi-Hua; Conlon, Lauren E; Lila, Mary Ann; Clinton, Steven K; Erdman, John W

    2013-08-15

    While putative disease-preventing lycopene metabolites are found in both tomato (Solanum lycopersicum) products and in their consumers, mammalian lycopene metabolism is poorly understood. Advances in tomato cell culturing techniques offer an economical tool for generation of highly-enriched (13)C-lycopene for human bioavailability and metabolism studies. To enhance the (13)C-enrichment and yields of labelled lycopene from the hp-1 tomato cell line, cultures were first grown in (13)C-glucose media for three serial batches and produced increasing proportions of uniformly labelled lycopene (14.3±1.2%, 39.6±0.5%, and 48.9±1.5%) with consistent yields (from 5.8 to 9 mg/L). An optimised 9-day-long (13)C-loading and 18-day-long labelling strategy developed based on glucose utilisation and lycopene yields, yielded (13)C-lycopene with 93% (13)C isotopic purity, and 55% of isotopomers were uniformly labelled. Furthermore, an optimised acetone and hexane extraction led to a fourfold increase in lycopene recovery from cultures compared to a standard extraction.

  20. Glucose metabolism, insulin sensitivity and β-cell function in type A insulin resistance syndrome around puberty: a 9-year follow-up.

    Science.gov (United States)

    Huang, Z; Liu, J; Ma, L; Wan, X; He, X; Fang, D; Liao, Z; Li, Y

    2014-01-01

    Diabetes mellitus is thought to be progressive. Insufficient insulin secretion in compensation for insulin resistance leads to glucose intolerance. A previously reported proband with type A insulin resistance syndrome and her younger twin brothers with and without the R1174W missense mutation in the insulin receptor gene were followed for 9 years to study the progression of glucose metabolism, insulin sensitivity, and β-cell function around puberty. Five-hour OGTT was performed in them at each visit. Areas under the curves of glucose, insulin and C-peptides, insulinogenic index, AIR, and Homa indices were assessed. Intramyocellular lipids (IMCLs) were quantified in the proband and compared to those of 12 nondiabetic subjects, 118 newly diagnosed type 2 diabetic patients. The proband maintained normal HbA1c (27-37 mmol/mol) and fasting plasma glucose (3.7-4.5 mmol/l), and her glucose tolerance ameliorated over years. The proband's Homa-IR decreased into adulthood, while her Homa-B, insulinogenic index, AIR, AUCs of insulin, and C-peptide decreased accordingly. Homa-B to Homa-IR ratios stayed significantly higher than normal. Homa-B, AUCs of insulin, and C-peptide of the twin brothers increased in response to the increment of Homa-IR as they entered middle and late puberty. The changes were more dramatic in the twin brothers carrying the mutation. IMCLs of the proband were lower than those of the nondiabetic counterparts and were disproportional for the degree of insulin resistance. Our longitudinal data of type A insulin resistance syndrome around puberty provide significant information for the study of insulin secretion in compensation for insulin resistance.

  1. Glucose Metabolism in the Progression of Prostate Cancer

    Science.gov (United States)

    Cutruzzolà, Francesca; Giardina, Giorgio; Marani, Marina; Macone, Alberto; Paiardini, Alessandro; Rinaldo, Serena; Paone, Alessio

    2017-01-01

    Prostate cancer is one of the most common types of cancer in western country males but the mechanisms involved in the transformation processes have not been clearly elucidated. Alteration in cellular metabolism in cancer cells is recognized as a hallmark of malignant transformation, although it is becoming clear that the biological features of metabolic reprogramming not only differ in different cancers, but also among different cells in a type of cancer. Normal prostate epithelial cells have a peculiar and very inefficient energy metabolism as they use glucose to synthesize citrate that is secreted as part of the seminal liquid. During the transformation process, prostate cancer cells modify their energy metabolism from inefficient to highly efficient, often taking advantage of the interaction with other cell types in the tumor microenvironment that are corrupted to produce and secrete metabolic intermediates used by cancer cells in catabolic and anabolic processes. We recapitulate the metabolic transformations occurring in the prostate from the normal cell to the metastasis, highlighting the role of the microenvironment and summarizing what is known on the molecular mechanisms involved in the process. PMID:28270771

  2. Insulin Stimulates S100B Secretion and These Proteins Antagonistically Modulate Brain Glucose Metabolism.

    Science.gov (United States)

    Wartchow, Krista Minéia; Tramontina, Ana Carolina; de Souza, Daniela F; Biasibetti, Regina; Bobermin, Larissa D; Gonçalves, Carlos-Alberto

    2016-06-01

    Brain metabolism is highly dependent on glucose, which is derived from the blood circulation and metabolized by the astrocytes and other neural cells via several pathways. Glucose uptake in the brain does not involve insulin-dependent glucose transporters; however, this hormone affects the glucose influx to the brain. Changes in cerebrospinal fluid levels of S100B (an astrocyte-derived protein) have been associated with alterations in glucose metabolism; however, there is no evidence whether insulin modulates glucose metabolism and S100B secretion. Herein, we investigated the effect of S100B on glucose metabolism, measuring D-(3)H-glucose incorporation in two preparations, C6 glioma cells and acute hippocampal slices, and we also investigated the effect of insulin on S100B secretion. Our results showed that: (a) S100B at physiological levels decreases glucose uptake, through the multiligand receptor RAGE and mitogen-activated protein kinase/ERK signaling, and (b) insulin stimulated S100B secretion via PI3K signaling. Our findings indicate the existence of insulin-S100B modulation of glucose utilization in the brain tissue, and may improve our understanding of glucose metabolism in several conditions such as ketosis, streptozotocin-induced dementia and pharmacological exposure to antipsychotics, situations that lead to changes in insulin signaling and extracellular levels of S100B.

  3. The Role of Glucose, Serum, and Three-Dimensional Cell Culture on the Metabolism of Bone Marrow-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Byron Deorosan

    2011-01-01

    factors in the metabolic response of the cells. However, cells cultured in low density collagen exhibited considerable cell death, likely because of physical contraction of the collagen hydrogel which was not observed in the higher density collagen. These findings will be useful to the development of in vitro cell culture models that properly mimic in vivo physiological processes.

  4. Metabolic fate of extracted glucose in normal human myocardium.

    OpenAIRE

    Wisneski, J A; Gertz, E W; Neese, R A; Gruenke, L D; D. L. Morris; Craig, J. C.

    1985-01-01

    Glucose is an important substrate for myocardial metabolism. This study was designed to determine the effect of circulating metabolic substrates on myocardial glucose extraction and to determine the metabolic fate of glucose in normal human myocardium. Coronary sinus and arterial catheters were placed in 23 healthy male volunteers. [6-14C]Glucose was infused as a tracer in 10 subjects. [6-14C]Glucose and [U-13C]lactate were simultaneously infused in the other 13 subjects. Simultaneous blood s...

  5. Role of SUMO-specific protease 2 in reprogramming cellular glucose metabolism.

    Directory of Open Access Journals (Sweden)

    Shuang Tang

    Full Text Available Most cancer cells exhibit a shift in glucose metabolic strategy, displaying increased glycolysis even with adequate oxygen supply. SUMO-specific proteases (SENPs de-SUMOylate substrates including HIF1α and p53,two key regulators in cancer glucose metabolism, to regulate their activity, stability and subcellular localization. However, the role of SENPs in tumor glucose metabolism remains unclear. Here we report that SUMO-specific protease 2 (SENP2 negatively regulates aerobic glycolysis in MCF7 and MEF cells. Over-expression of SENP2 reduces the glucose uptake and lactate production, increasing the cellular ATP levels in MCF7 cells, while SENP2 knockout MEF cells show increased glucose uptake and lactate production along with the decreased ATP levels. Consistently, the MCF7 cells over-expressing SENP2 exhibit decreased expression levels of key glycolytic enzymes and an increased rate of glucose oxidation compared with control MCF7 cells, indicating inhibited glycolysis but enhanced oxidative mitochondrial respiration. Moreover, SENP2 over-expressing MCF7 cells demonstrated a reduced amount of phosphorylated AKT, whereas SENP2 knockout MEFs exhibit increased levels of phosphorylated AKT. Furthermore, inhibiting AKT phosphorylation by LY294002 rescued the phenotype induced by SENP2 deficiency in MEFs. In conclusion, SENP2 represses glycolysis and shifts glucose metabolic strategy, in part through inhibition of AKT phosphorylation. Our study reveals a novel function of SENP2 in regulating glucose metabolism.

  6. Neuronal Cell Death Induced by Mechanical Percussion Trauma in Cultured Neurons is not Preceded by Alterations in Glucose, Lactate and Glutamine Metabolism

    Science.gov (United States)

    Jayakumar, A. R.; Bak, L. K.; Rama Rao, K. V.; Waagepetersen, H.S.; Schousboe, A.; Norenberg, M.D.

    2016-01-01

    Traumatic brain injury (TBI) is a devastating neurological disorder that usually presents in acute and chronic forms. Brain edema and associated increased intracranial pressure in the early phase following TBI are major consequences of acute trauma. On the other hand, neuronal injury, leading to neurobehavioral and cognitive impairments, that usually develop months to years after single or repetitive episodes of head trauma, are major consequences of chronic TBI. The molecular mechanisms responsible for TBI-induced injury, however, are unclear. Recent studies have suggested that early mitochondrial dysfunction and subsequent energy failure play a role in the pathogenesis of TBI. We therefore examined whether oxidative metabolism of 13C-labeled glucose, lactate or glutamine is altered early following in vitro mechanical percussion-induced trauma (5 atm) to neurons (4–24 h), and whether such events contribute to the development of neuronal injury. Cell viability was assayed using the release of the cytoplasmic enzyme lactate dehydrogenase (LDH), together with fluorescence-based cell staining (calcein and ethidium homodimer-1 for live and dead cells, respectively). Trauma had no effect on the LDH release in neurons from 1 h to 18 h. However, a significant increase in LDH release was detected at 24 h after trauma. Similar findings were identified when traumatized neurons were stained with fluorescent markers. Additionally 13C-labeling of glutamate showed a small, but statistically significant decrease at 14 h after trauma. However, trauma had no effect on the cycling ratio of the TCA cycle at any time-period examined. These findings indicate that trauma does not cause a disturbance in oxidative metabolism of any of the substrates used for neurons. Accordingly, such metabolic disturbance does not appear to contribute to the neuronal death in the early stages following trauma. PMID:26729365

  7. Oxygen-glucose deprivation inducing B1 RNA inhibits neuronal cells metabolic activity by NLRP3 and associated proinflammatory cytokines production.

    Science.gov (United States)

    Wang, Li; Wang, Weihua; Zhang, Lei; Dai, Peng; Wang, Kai; Hui, Hao; Rao, Wei; Peng, Cheng; Yang, Jinghua; Yan, Zhen; Fei, Zhou

    2015-02-19

    Cerebral ischemia occurs when blood flow to part of the brain is obstructed, which can result in oxygen and glucose deprivation (OGD) and neuronal damage. However, the mechanisms remain poorly understood. The present study investigated the production and effects of double-stranded RNA (dsRNA) induced by OGD in neuronal cells. By confocal microscopy, dsRNA containing B1 and B2 RNA, was found accumulating in HT22 cells under OGD treatment. The sequence of B1 RNA was identified and transfected into HT22 cells. Interestingly, B1 RNA induced transcription and expression of NLRP3, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α, which was similar to the effects of OGD treatment. Moreover, HT22 cell growth inhibition and proinflammatory cytokines production induced by OGD and B1 RNA treatment were down-regulated by NLRP3 knock-down. These findings suggest that B1 RNA induced by OGD forms as dsRNA and inhibits neuronal cell metabolic activity by regulating the NLRP3 and associated proinflammatory cytokines production.

  8. The Acute Effects of Low-Dose TNF-α on Glucose Metabolism and β-Cell Function in Humans

    DEFF Research Database (Denmark)

    Ibfelt, Tobias; Fischer, Christian Philip; Plomgaard, Peter

    2014-01-01

    and in vivo. However, it is unclear whether TNF-α may also affect endogenous glucose production (EGP) during fasting and glucose-stimulated insulin secretion (GSIS) in vivo. We hypothesized that low-dose TNF- α would increase EGP and attenuate GSIS. Recombinant human TNF-α or placebo was infused in healthy......Type 2 diabetes is characterized by increased insulin resistance and impaired insulin secretion. Type 2 diabetes is also associated with low-grade inflammation and increased levels of proinflammatory cytokines such as TNF-α. TNF-α has been shown to impair peripheral insulin signaling in vitro......, nondiabetic young men (n = 10) during a 4-hour basal period followed by an intravenous glucose tolerance test (IVGTT). TNF-α lowered insulin levels by 12% during the basal period (P

  9. DLK1 regulates whole body glucose metabolism

    DEFF Research Database (Denmark)

    Abdallah, Basem; Ditzel, Nicholas; Laborda, Jorge

    2015-01-01

    The endocrine role of the skeleton in regulating energy metabolism is supported by a feed forward loop between circulating osteoblasts (OBs)-derived undercaboxylated osteocalcin (Glu-OCN) and pancreatic β-cell-insulin; in turn insulin favors osteocalcin bioactivity. These data suggest the existence...... cells acts as a negative feedback mechanism to counteract the stimulatory effects of insulin on osteoblast production of Glu-OCN, a potential mechanism preventing OCN-induced hypoglycemia....

  10. Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome

    DEFF Research Database (Denmark)

    Leder, Lena; Kolehmainen, Marjukka; Narverud, Ingunn;

    2016-01-01

    BACKGROUND: Diet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism......-related genes in peripheral blood mononuclear cells (PBMCs) during a 2-h oral glucose tolerance test (OGTT) in individuals with MetS. METHODS: A Nordic multicenter randomized dietary study included subjects (n = 213) with MetS, randomized to a ND group or a control diet (CD) group applying an isocaloric study...... protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L(-1), and baseline body mass index

  11. Tumor Delineation and Quantitative Assessment of Glucose Metabolic Rate within Histologic Subtypes of Non-Small Cell Lung Cancer by Using Dynamic (18)F Fluorodeoxyglucose PET.

    Science.gov (United States)

    Meijer, Tineke W H; de Geus-Oei, Lioe-Fee; Visser, Eric P; Oyen, Wim J G; Looijen-Salamon, Monika G; Visvikis, Dimitris; Verhagen, Ad F T M; Bussink, Johan; Vriens, Dennis

    2016-11-15

    Purpose To assess whether dynamic fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) has added value over static (18)F-FDG PET for tumor delineation in non-small cell lung cancer (NSCLC) radiation therapy planning by using pathology volumes as the reference standard and to compare pharmacokinetic rate constants of (18)F-FDG metabolism, including regional variation, between NSCLC histologic subtypes. Materials and Methods The study was approved by the institutional review board. Patients gave written informed consent. In this prospective observational study, 1-hour dynamic (18)F-FDG PET/computed tomographic examinations were performed in 35 patients (36 resectable NSCLCs) between 2009 and 2014. Static and parametric images of glucose metabolic rate were obtained to determine lesion volumes by using three delineation strategies. Pathology volume was calculated from three orthogonal dimensions (n = 32). Whole tumor and regional rate constants and blood volume fraction (VB) were computed by using compartment modeling. Results Pathology volumes were larger than PET volumes (median difference, 8.7-25.2 cm(3); Wilcoxon signed rank test, P segmentation on static (18)F-FDG PET images is in best agreement with pathology volume and could be useful for NSCLC autocontouring. Differences in glycolytic rate and VB between SCC and AC are relevant for research in targeting agents and radiation therapy dose escalation. (©) RSNA, 2016 Online supplemental material is available for this article.

  12. Parameters of glucose metabolism and the aging brain

    DEFF Research Database (Denmark)

    Akintola, Abimbola A; van den Berg, Annette; Altmann-Schneider, Irmhild;

    2015-01-01

    Given the concurrent, escalating epidemic of diabetes mellitus and neurodegenerative diseases, two age-related disorders, we aimed to understand the relation between parameters of glucose metabolism and indices of pathology in the aging brain. From the Leiden Longevity Study, 132 participants (mean...... age 66 years) underwent a 2-h oral glucose tolerance test to assess glucose tolerance (fasted and area under the curve (AUC) glucose), insulin sensitivity (fasted and AUC insulin and homeostatic model assessment of insulin sensitivity (HOMA-IS)) and insulin secretion (insulinogenic index). 3-T brain...... different parameters of glucose metabolism (impairment of which is characteristic of diabetes mellitus) and brain aging....

  13. AMP-Activated Protein Kinase Plays an Important Evolutionary Conserved Role in the Regulation of Glucose Metabolism in Fish Skeletal Muscle Cells

    NARCIS (Netherlands)

    Magnoni, L.J.; Vraskou, Y.; Palstra, A.P.; Planas, J.V.

    2012-01-01

    AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP:ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds tha

  14. Differential Incorporation of Glucose into Biomass during Warburg Metabolism

    OpenAIRE

    Chen, Ying-Jr; Huang, Xiaojing; Mahieu, Nathaniel G.; Cho, Kevin; Schaefer, Jacob; Patti, Gary J.

    2014-01-01

    It is well established that most cancer cells take up an increased amount of glucose relative to that taken up by normal differentiated cells. The majority of this glucose carbon is secreted from the cell as lactate. The fate of the remaining glucose carbon, however, has not been well-characterized. Here we apply a novel combination of metabolomic technologies to track uniformly labeled glucose in HeLa cancer cells. We provide a list of specific intracellular metabolites that become enriched ...

  15. Insulin signalling and the regulation of glucose and lipid metabolism

    Science.gov (United States)

    Saltiel, Alan R.; Kahn, C. Ronald

    2001-12-01

    The epidemic of type 2 diabetes and impaired glucose tolerance is one of the main causes of morbidity and mortality worldwide. In both disorders, tissues such as muscle, fat and liver become less responsive or resistant to insulin. This state is also linked to other common health problems, such as obesity, polycystic ovarian disease, hyperlipidaemia, hypertension and atherosclerosis. The pathophysiology of insulin resistance involves a complex network of signalling pathways, activated by the insulin receptor, which regulates intermediary metabolism and its organization in cells. But recent studies have shown that numerous other hormones and signalling events attenuate insulin action, and are important in type 2 diabetes.

  16. Persistent impaired glucose metabolism in a zebrafish hyperglycemia model.

    Science.gov (United States)

    Capiotti, Katiucia Marques; Antonioli, Régis; Kist, Luiza Wilges; Bogo, Maurício Reis; Bonan, Carla Denise; Da Silva, Rosane Souza

    2014-05-01

    Diabetes mellitus (DM) affects over 10% of the world's population. Hyperglycemia is the main feature for the diagnosis of this disease. The zebrafish (Danio rerio) is an established model organism for the study of various metabolic diseases. In this paper, hyperglycemic zebrafish, when immersed in a 111 mM glucose solution for 14 days, developed increased glycation of proteins from the eyes, decreased mRNA levels of insulin receptors in the muscle, and a reversion of high blood glucose level after treatment with anti-diabetic drugs (glimepiride and metformin) even after 7 days of glucose withdrawal. Additionally, hyperglycemic zebrafish developed an impaired response to exogenous insulin, which was recovered after 7 days of glucose withdrawal. These data suggest that the exposure of adult zebrafish to high glucose concentration is able to induce persistent metabolic changes probably underlined by a hyperinsulinemic state and impaired peripheral glucose metabolism.

  17. Metabolism of [U-13C]glucose in Human Brain Tumors In Vivo

    Science.gov (United States)

    Maher, Elizabeth A.; Marin-Valencia, Isaac; Bachoo, Robert M.; Mashimo, Tomoyuki; Raisanen, Jack; Hatanpaa, Kimmo J.; Jindal, Ashish; Jeffrey, F. Mark; Choi, Changho; Madden, Christopher; Mathews, Dana; Pascual, Juan M.; Mickey, Bruce E.; Malloy, Craig R.; DeBerardinis, Ralph J.

    2012-01-01

    Glioblastomas (GBMs) and brain metastases demonstrate avid uptake of 18fluoro-2-deoxyglucose (FDG) by positron emission tomography (PET) and display perturbations of intracellular metabolite pools by 1H magnetic resonance spectroscopy (MRS). These observations suggest that metabolic reprogramming contributes to brain tumor growth in vivo. The Warburg effect, excess metabolism of glucose to lactate in the presence of oxygen, is a hallmark of cancer cells in culture. FDG-positive tumors are assumed to metabolize glucose in a similar manner, with high rates of lactate formation compared to mitochondrial glucose oxidation, but few studies have specifically examined the metabolic fates of glucose in vivo. In particular, the capacity of human brain malignancies to oxidize glucose in the tricarboxylic acid cycle is unknown. Here we studied the metabolism of human brain tumors in situ. [U-13C]glucose was infused during surgical resection, and tumor samples were subsequently subjected to 13C NMR spectroscopy. Analysis of tumor metabolites revealed lactate production, as expected. We also determined that pyruvate dehydrogenase, turnover of the TCA cycle, anaplerosis and de novo glutamine and glycine synthesis contributed significantly to the ultimate disposition of glucose carbon. Surprisingly, less than 50% of the acetyl-CoA pool was derived from blood-borne glucose, suggesting that additional substrates contribute to tumor bioenergetics. This study illustrates a convenient approach that capitalizes on the high information content of 13C NMR spectroscopy and enables the analysis of intermediary metabolism in diverse malignancies growing in their native microenvironment. PMID:22419606

  18. Glucose metabolism in isolated rat adipocytes: estimate of total recovery by the product summation method.

    Science.gov (United States)

    Groff, J L; Stugard, C E; Mays, C J; Koopmans, H S; DiGirolamo, M

    1992-03-01

    To determine the completeness of glucose recovery into its metabolic products, adipocyte glucose utilization was compared by two different methods in a basal and in an insulin-stimulated metabolic state. One of the methods (product summation) is based on the recovery of (( U-14C ))-labeled glucose in carbon dioxide and triglyceride, together with the assay of lactate and pyruvate released into the medium from the incubated cells. The second method is a modification of a procedure by which the quantity of tritiated water that is released by metabolism from +AD5-3H+BD-labeled glucose is determined. It was found that the results of the two methods were in very close agreement. Neither method measures glucose conversion to glycogen. However, glycogenic activity is very low in adipocytes and represents only a small percentage of utilized glucose. Therefore, the finding of comparable results between the two methods suggests that the summation of the metabolic products carbon dioxide, triglyceride, lactate, and pyruvate does account for nearly all of the glucose utilized. This has important implications for the understanding of the considerable variations in rate and patterns of glucose metabolism by the fat cells under a variety of experimental conditions.

  19. Local cerebral glucose metabolism during controlled hypoxemia in rats.

    Science.gov (United States)

    Pulsinelli, W A; Duffy, T E

    1979-05-11

    2-Deoxy-[14C]glucose metabolism was examined in brains of hypoxic, normotensive rats by autoradiography, which revealed alternating cortical columns of high and low metabolism. Activity in white matter was increased severalfold over that in adjacent gray matter. The columns were anatomically related to penetrating cortical arteries with areas between arteries demonstrating higher rates of metabolism. The results suggest the presence of interarterial tissue oxygen gradients that influence regional glucose metabolism. The relatively greater sensitivity of white matter metabolism to hypoxia may lead to an understanding of white matter damage in postanoxic leukoencephalopathy.

  20. Berberine improves glucose metabolism through induction of glycolysis.

    Science.gov (United States)

    Yin, Jun; Gao, Zhanguo; Liu, Dong; Liu, Zhijun; Ye, Jianping

    2008-01-01

    Berberine, a botanical alkaloid used to control blood glucose in type 2 diabetes in China, has recently been reported to activate AMPK. However, it is not clear how AMPK is activated by berberine. In this study, activity and action mechanism of berberine were investigated in vivo and in vitro. In dietary obese rats, berberine increased insulin sensitivity after 5-wk administration. Fasting insulin and HOMA-IR were decreased by 46 and 48%, respectively, in the rats. In cell lines including 3T3-L1 adipocytes, L6 myotubes, C2C12 myotubes, and H4IIE hepatocytes, berberine was found to increase glucose consumption, 2-deoxyglucose uptake, and to a less degree 3-O-methylglucose (3-OMG) uptake independently of insulin. The insulin-induced glucose uptake was enhanced by berberine in the absence of change in IRS-1 (Ser307/312), Akt, p70 S6, and ERK phosphorylation. AMPK phosphorylation was increased by berberine at 0.5 h, and the increase remained for > or =16 h. Aerobic and anaerobic respiration were determined to understand the mechanism of berberine action. The long-lasting phosphorylation of AMPK was associated with persistent elevation in AMP/ATP ratio and reduction in oxygen consumption. An increase in glycolysis was observed with a rise in lactic acid production. Berberine exhibited no cytotoxicity, and it protected plasma membrane in L6 myotubes in the cell culture. These results suggest that berberine enhances glucose metabolism by stimulation of glycolysis, which is related to inhibition of glucose oxidation in mitochondria. Berberine-induced AMPK activation is likely a consequence of mitochondria inhibition that increases the AMP/ATP ratio.

  1. FGF19 Regulates Cell Proliferation, Glucose and Bile Acid Metabolism via FGFR4-Dependent and Independent Pathways

    OpenAIRE

    Ai-Luen Wu; Sally Coulter; Christopher Liddle; Anne Wong; Jeffrey Eastham-Anderson; French, Dorothy M.; Peterson, Andrew S.; Junichiro Sonoda

    2011-01-01

    Fibroblast growth factor 19 (FGF19) is a hormone-like protein that regulates carbohydrate, lipid and bile acid metabolism. At supra-physiological doses, FGF19 also increases hepatocyte proliferation and induces hepatocellular carcinogenesis in mice. Much of FGF19 activity is attributed to the activation of the liver enriched FGF Receptor 4 (FGFR4), although FGF19 can activate other FGFRs in vitro in the presence of the coreceptor βKlotho (KLB). In this report, we investigate the role of FGFR4...

  2. Aerobic glucose metabolism of Saccharomyces kluyveri: Growth, metabolite production, and quantification of metabolic fluxes

    DEFF Research Database (Denmark)

    Møller, Kasper; Christensen, B.; Förster, Jochen

    2002-01-01

    .29 +/- 0.01 g/g). The glucose metabolism of S. kluyveri was further characterized by the new and powerful techniques of metabolic network analysis. Flux distributions in the central carbon metabolism were estimated for respiro-fermentative growth in aerobic batch cultivation on glucose and respiratory...... at a constant specific rate of 0.12 g ethyl acetate per g dry weight per hour. The aerobic glucose metabolism in S. kluyveri was found to be less fermentative than in S. cerevisiae, as illustrated by the comparably low yield of ethanol on glucose (0.08 +/- 0.02 g/g), and high yield of biomass on glucose (0...... growth in aerobic glucose-limited continuous cultivation. It was found that in S. kluyveri the flux into the pentose phosphate pathway was 18.8 mmole per 100 mmole glucose consumed during respiratory growth in aerobic glucose-limited continuous cultivation. Such a low flux into the pentose phosphate...

  3. Further studies of the influence of apolipoprotein B alleles on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Bentzen, Joan; Poulsen, Pernille; Vaag, Allan;

    2003-01-01

    The effect of five genetic polymorphisms in the apolipoprotein B gene on parameters of lipid and glucose metabolism was assessed in 564 Danish mono- and dizygotic twins. Genotypes in apolipoprotein B T71I (ApaLI RFLP), A591V (AluI RFLP), L2712P (MvaI RFLP), R3611Q (MspI RFLP), and E4154K (Eco...... was seen in the dizygotic twins. The effect of the polymorphisms on lipid and glucose parameters could be mediated through linkage to genes with known effect on glucose metabolism or through free fatty acids exerting their effect on glucose metabolism.......RI RFLP) were established using polymerase chain reaction and restriction enzyme digests. The effect of genotypes on lipid levels and on glucose, insulin, and HOMA (i.e., calculated parameters of beta-cell function and insulin resistance) was assessed by multivariate analyses of variance correcting...

  4. Regional glucose metabolism using PETT in normal and psychiatric populations

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, J.D.; Wolf, A.P.; Volkow, N.

    1982-01-01

    The metabolism of /sup 18/F-2-deoxy-2-fluoro-D-glucose (/sup 18/FDG) in 150 subjects including normals, schizophrenics, senile dementias, and primary affective disorders was studied. Some of the data analyzed to date are discussed.

  5. Roles of Chlorogenic Acid on Regulating Glucose and Lipids Metabolism: A Review

    Directory of Open Access Journals (Sweden)

    Shengxi Meng

    2013-01-01

    Full Text Available Intracellular glucose and lipid metabolic homeostasis is vital for maintaining basic life activities of a cell or an organism. Glucose and lipid metabolic disorders are closely related with the occurrence and progression of diabetes, obesity, hepatic steatosis, cardiovascular disease, and cancer. Chlorogenic acid (CGA, one of the most abundant polyphenol compounds in the human diet, is a group of phenolic secondary metabolites produced by certain plant species and is an important component of coffee. Accumulating evidence has demonstrated that CGA exerts many biological properties, including antibacterial, antioxidant, and anticarcinogenic activities. Recently, the roles and applications of CGA, particularly in relation to glucose and lipid metabolism, have been highlighted. This review addresses current studies investigating the roles of CGA in glucose and lipid metabolism.

  6. Adult glucose metabolism in extremely birthweight-discordant monozygotic twins

    DEFF Research Database (Denmark)

    Frost, M; Petersen, I; Brixen, K

    2012-01-01

    Low birthweight (BW) is associated with increased risk of type 2 diabetes. We compared glucose metabolism in adult BW-discordant monozygotic (MZ) twins, thereby controlling for genetic factors and rearing environment.......Low birthweight (BW) is associated with increased risk of type 2 diabetes. We compared glucose metabolism in adult BW-discordant monozygotic (MZ) twins, thereby controlling for genetic factors and rearing environment....

  7. Non-invasive in-cell determination of free cytosolic [NAD+]/[NADH] ratios using hyperpolarized glucose show large variations in metabolic phenotypes

    DEFF Research Database (Denmark)

    Christensen, Caspar Elo; Karlsson, Magnus; Winther, Jakob R.;

    2014-01-01

    a magnetic enhancement technique (hyperpolarization) with cellular glycolytic activity. The bioprobe reports free cytosolic [NAD+]/[NADH] ratios based on dynamically measured in-cell [pyruvate]/ [lactate] ratios. We demonstrate its utility in breast and prostate cancer cells. The free cytosolic [NAD......+]/[NADH] ratio determined in prostate cancer cells was 4 times higher than in breast cancer cells. This higher ratio reflects a distinct metabolic phenotype of prostate cancer cells consistent with previously reported alterations in the energy metabolism of these cells. As a reporter on free cytosolic [NAD...... death and oxidative stress. It has been suggested that changes in the ratio of free cytosolic [NAD+]/[NADH] reflects metabolic alterations leading to, or correlating with, pathological states. We have designed an isotopically labelled metabolic bioprobe of free cytosolic [NAD+]/[NADH] by combining...

  8. Dietary iron controls circadian hepatic glucose metabolism through heme synthesis.

    Science.gov (United States)

    Simcox, Judith A; Mitchell, Thomas Creighton; Gao, Yan; Just, Steven F; Cooksey, Robert; Cox, James; Ajioka, Richard; Jones, Deborah; Lee, Soh-Hyun; King, Daniel; Huang, Jingyu; McClain, Donald A

    2015-04-01

    The circadian rhythm of the liver maintains glucose homeostasis, and disruption of this rhythm is associated with type 2 diabetes. Feeding is one factor that sets the circadian clock in peripheral tissues, but relatively little is known about the role of specific dietary components in that regard. We assessed the effects of dietary iron on circadian gluconeogenesis. Dietary iron affects circadian glucose metabolism through heme-mediated regulation of the interaction of nuclear receptor subfamily 1 group d member 1 (Rev-Erbα) with its cosuppressor nuclear receptor corepressor 1 (NCOR). Loss of regulated heme synthesis was achieved by aminolevulinic acid (ALA) treatment of mice or cultured cells to bypass the rate-limiting enzyme in hepatic heme synthesis, ALA synthase 1 (ALAS1). ALA treatment abolishes differences in hepatic glucose production and in the expression of gluconeogenic enzymes seen with variation of dietary iron. The differences among diets are also lost with inhibition of heme synthesis with isonicotinylhydrazine. Dietary iron modulates levels of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a transcriptional activator of ALAS1, to affect hepatic heme. Treatment of mice with the antioxidant N-acetylcysteine diminishes PGC-1α variation observed among the iron diets, suggesting that iron is acting through reactive oxygen species signaling.

  9. Effects of MDMA on blood glucose levels and brain glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Montenegro, M.L.; Vaquero, J.J.; Garcia-Barreno, P.; Desco, M. [Hospital General Universitario Gregorio Maranon, Laboratorio de Imagen, Medicina Experimental, Madrid (Spain); Arango, C. [Hospital General Gregorio Maranon, Departamento de Psiquiatria, Madrid (Spain); Ricaurte, G. [Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD (United States)

    2007-06-15

    This study was designed to assess changes in glucose metabolism in rats administered single or repeated doses of MDMA. Two different experiments were performed: (1) A single-dose study with four groups receiving 20 mg/kg, 40 mg/kg, saline or heat, and (2) a repeated-dose study with two groups receiving three doses, at intervals of 2 h, of 5 mg/kg or saline. Rats were imaged using a dedicated small-animal PET scanner 1 h after single-dose administration or 7 days after repeated doses. Glucose metabolism was measured in 12 cerebral regions of interest. Rectal temperature and blood glucose were monitored. Peak body temperature was reached 1 h after MDMA administration. Blood glucose levels decreased significantly after MDMA administration. In the single-dose experiment, brain glucose metabolism showed hyperactivation in cerebellum and hypo-activation in the hippocampus, amygdala and auditory cortex. In the repeated-dose experiment, brain glucose metabolism did not show any significant change at day 7. These results are the first to indicate that MDMA has the potential to produce significant hypoglycaemia. In addition, they show that MDMA alters glucose metabolism in components of the motor, limbic and somatosensory systems acutely but not on a long-term basis. (orig.)

  10. Responsiveness to D-glucose in neurosecretory cells of crustaceans.

    Science.gov (United States)

    García, E; Benítez, A; Onetti, C G

    1993-08-01

    1. An electrophysiological study of the D-glucose sensitivity of X-organ (XO) neurosecretory cell bodies in crayfish was carried out with the use of microelectrodes, perforated, and cell-attached patch-clamp techniques. 2. Glucose depolarizes the membrane potential of XO cells in a concentration-dependent manner. 3. Depolarization produced by glucose initiates a change in the pattern of electrical activity. Silent cells began to discharge action potentials. When bursting cells are depolarized by glucose, their action potentials are no longer grouped in bursts or disappear entirely. 4. Although the membrane potential returns to its initial value after removing glucose from the bath, discharge patterns of the cells may remain different. This suggests that besides the depolarizing effect, once the cells have been exposed to glucose, the sugar switches on a process that is maintained for a long time. 5. Glucose produced a reduction of membrane steady-state conductance, and a shift of reversal potential of membrane currents to a more positive value. 6. Depolarization induced by D-glucose appears to be related with a closure of potassium channels. 7. Glucose effect was thought to be generated by a product of metabolism that would act as intracellular mediator.

  11. Evaluation of glucose metabolism in women with multiple ovarian follicles

    Institute of Scientific and Technical Information of China (English)

    Shulan Lü; Xiaoyan Guo; Zuansun Cao; Wenjun Mao

    2007-01-01

    Objective:To investigate glucose metabolism in women with multiple ovarian follicles (MOF) and explore the relationship between glucose metabolism, insulin resistance and body weight. Methods:We evaluated 46 women with MFO and 30 nor mal women as controls. All the subjects were given 75g of glucose orally in order to perform the oral glucose tolerance test(OGTT) and insulin releasing test(IRT), and they were also evaluated for insulin resistance using the insulin resistance index with homeostatic model assessment (HOMA). Results:The occurrence of impaired glucose tolerance in women with MOF was 10.87%, which was significantly higher than that in the control group (3.33% ,P < 0.05). The rate of insulin resistance was 30.43% in the study group as compared to 10.00% in the control group. The results showed that there was significant difference between the two groups(P < 0.05). The levels of FSH,LH,PRL,E2,T and P between the two groups had no significant difference (P > 0.05). BMI in women with impaired glucose tolerance was correlated positively to insulin resistance (r =0.567, P < 0.05). Conclusion :Abnormal glucose metabolism was observed in women with unitary multiple ovarian follicles,and this could be attributed to obesity and insulin resistance. Women with MOF and associated obesity should be subjected to OGTT so that their glucose levels can be monitored as a preventive measure.

  12. Correlation of brain cell glucose metabolism and patient's condition in children with epileptic encephalopathy An assessment using fluorine-18-fluoro-2-deoxy-D-glucose positron emission computed tomography

    Institute of Scientific and Technical Information of China (English)

    Qiongxiang Zhai; Yuxiong Guo; Yuxin Zhang; Zhihong Chen; Jian Ding; Juan Gui; Ying Hao

    2011-01-01

    We examined a total of 16 children with epileptic encephalopathy using fluorine-18-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission computed tomography (PET), magnetic resonance imaging (MRI) and electroencephalography.Children with infantile spasms showed significant mental retardation, severely abnormal electroencephalogram recordings, and bilateral diffuse cerebral cortex hypometabolism with 18F-FDG PET imaging.MRI in these cases showed brain atrophy, multi-micropolygyria, macrogyria, and porencephalia.In cases with Lennox-Gastaut syndrome, 18F-FDG PET showed bilateral diffuse glucose hypometabolism, while MRI showed cortical atrophy, heterotopic gray matter and tuberous sclerosis.MRI in cases with myoclonic encephalopathy demonstrated bilateral frontal and temporal cortical and white matter atrophy and 18F-FDG PET imaging showed bilateral frontal lobe atrophy with reduced bilateral frontal cortex, occipital cortex, temporal cortex and cerebellar glucose uptake.In children who could not be clearly classified, MRI demonstrated cerebral cortical atrophy and 18F-FDG PET exhibited multifocal glucose hypometabolism.Overall, this study demonstrated that the degree of brain metabolic abnormality was consistent with clinical seizure severity.In addition, 18F-FDG PET imaging after treatment was consistent with clinical outcomes.These findings indicate that 18F-FDG PET can be used to assess the severity of brain injury and prognosis in children with epileptic encephalopathy.

  13. Effects of central gastrin-releasing peptide on glucose metabolism

    NARCIS (Netherlands)

    Jha, Pawan Kumar; Foppen, Ewout; Challet, Etienne; Kalsbeek, A.

    2015-01-01

    Gastrin-releasing peptide (GRP) mediated signals in the central nervous system (CNS) influence many functions associated with energy metabolism. The purpose of the present study was to investigate the central effect of GRP on glucose metabolism in the male rat. Intracerebroventricular (icv) administ

  14. Utilization of dietary glucose in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Alemany Marià

    2011-10-01

    Full Text Available Abstract This review is focused on the fate of dietary glucose under conditions of chronically high energy (largely fat intake, evolving into the metabolic syndrome. We are adapted to carbohydrate-rich diets similar to those of our ancestors. Glucose is the main energy staple, but fats are our main energy reserves. Starvation drastically reduces glucose availability, forcing the body to shift to fatty acids as main energy substrate, sparing glucose and amino acids. We are not prepared for excess dietary energy, our main defenses being decreased food intake and increased energy expenditure, largely enhanced metabolic activity and thermogenesis. High lipid availability is a powerful factor decreasing glucose and amino acid oxidation. Present-day diets are often hyperenergetic, high on lipids, with abundant protein and limited amounts of starchy carbohydrates. Dietary lipids favor their metabolic processing, saving glucose, which additionally spares amino acids. The glucose excess elicits hyperinsulinemia, which may derive, in the end, into insulin resistance. The available systems of energy disposal could not cope with the excess of substrates, since they are geared for saving not for spendthrift, which results in an unbearable overload of the storage mechanisms. Adipose tissue is the last energy sink, it has to store the energy that cannot be used otherwise. However, adipose tissue growth also has limits, and the excess of energy induces inflammation, helped by the ineffective intervention of the immune system. However, even under this acute situation, the excess of glucose remains, favoring its final conversion to fat. The sum of inflammatory signals and deranged substrate handling induce most of the metabolic syndrome traits: insulin resistance, obesity, diabetes, liver steatosis, hyperlipidemia and their compounded combined effects. Thus, a maintained excess of energy in the diet may result in difficulties in the disposal of glucose, eliciting

  15. A link between sleep loss, glucose metabolism and adipokines

    Directory of Open Access Journals (Sweden)

    H.G. Padilha

    2011-10-01

    Full Text Available The present review evaluates the role of sleep and its alteration in triggering problems of glucose metabolism and the possible involvement of adipokines in this process. A reduction in the amount of time spent sleeping has become an endemic condition in modern society, and a search of the current literature has found important associations between sleep loss and alterations of nutritional and metabolic contexts. Studies suggest that sleep loss is associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and type 2 diabetes mellitus. The mechanism involved may be associated with the decreased efficacy of regulation of the hypothalamus-pituitary-adrenal axis by negative feedback mechanisms in sleep-deprivation conditions. In addition, changes in the circadian pattern of growth hormone (GH secretion might also contribute to the alterations in glucose regulation observed during sleep loss. On the other hand, sleep deprivation stress affects adipokines - increasing tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 and decreasing leptin and adiponectin -, thus establishing a possible association between sleep-debt, adipokines and glucose metabolism. Thus, a modified release of adipokines resulting from sleep deprivation could lead to a chronic sub-inflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes mellitus. Further studies are necessary to investigate the role of sleep loss in adipokine release and its relationship with glucose metabolism.

  16. Enhanced muscle glucose metabolism after exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Garetto, L P; Goodman, M N;

    1984-01-01

    Studies in the rat suggest that after voluntary exercise there are two phases of glycogen repletion in skeletal muscle (preceding study). In phase I glucose utilization and glycogen synthesis are enhanced both in the presence and absence of insulin, whereas in phase II only the increase in the pr...

  17. Preliminary Study of Brain Glucose Metabolism Changes in Patients with Lung Cancer of Different Histological Types

    Institute of Scientific and Technical Information of China (English)

    Wei-Ling Li; Chang Fu; Ang Xuan; Da-Peng Shi; Yong-Ju Gao; Jie Zhang; Jun-Ling Xu

    2015-01-01

    Background:Cerebral glucose metabolism changes are always observed in patients suffering from malignant tumors.This preliminary study aimed to investigate the brain glucose metabolism changes in patients with lung cancer of different histological types.Methods:One hundred and twenty patients with primary untreated lung cancer,who visited People's Hospital of Zhengzhou University from February 2012 to July 2013,were divided into three groups based on histological types confirmed by biopsy or surgical pathology,which included adenocarcinoma (52 cases),squamous cell carcinoma (43 cases),and small-cell carcinoma (25 cases).The whole body 18F-fluorodeoxyglucose (1 8F-FDG) positron emission tomography (PET)/computed tomography (CT) of these cases was retrospectively studied.The brain PET data of three groups were analyzed individually using statistical parametric maps (SPM) software,with 50 age-matched and gender-matched healthy controls for comparison.Results:The brain resting glucose metabolism in all three lung cancer groups showed regional cerebral metabolic reduction.The hypo-metabolic cerebral regions were mainly distributed at the left superior and middle frontal,bilateral superior and middle temporal and inferior and middle temporal gyrus.Besides,the hypo-metabolic regions were also found in the right inferior parietal lobule and hippocampus in the small-cell carcinoma group.The area of the total hypo-metabolic cerebral regions in the small-cell carcinoma group (total voxel value 3255) was larger than those in the adenocarcinoma group (total voxel value 1217) and squamous cell carcinoma group (total voxel value 1292).Conclusions:The brain resting glucose metabolism in patients with lung cancer shows regional cerebral metabolic reduction and the brain hypo-metabolic changes are related to the histological types of lung cancer.

  18. Gastric emptying, glucose metabolism and gut hormones

    DEFF Research Database (Denmark)

    Vermeulen, Mechteld A R; Richir, Milan C; Garretsen, Martijn K

    2011-01-01

    To study the gastric-emptying rate and gut hormonal response of two carbohydrate-rich beverages. A specifically designed carbohydrate-rich beverage is currently used to support the surgical patient metabolically. Fruit-based beverages may also promote recovery, due to natural antioxidant...... and carbohydrate content. However, gastric emptying of fluids is influenced by its nutrient composition; hence, safety of preoperative carbohydrate loading should be confirmed. Because gut hormones link carbohydrate metabolism and gastric emptying, hormonal responses were studied....

  19. Ghrelin function in insulin release and glucose metabolism.

    Science.gov (United States)

    Dezaki, Katsuya

    2013-01-01

    Given its wide spectrum of biological activities such as growth hormone (GH) release, feeding stimulation, adiposity and cardiovascular actions, the discovery of ghrelin opened many new perspectives within neuroendocrine, metabolic and cardiovascular research, thus suggesting its possible clinical application. Circulating ghrelin is produced predominantly in the stomach, and its receptor GH secretagogue receptor (GHS-R) is expressed in a variety of central and peripheral tissues. Ghrelin, GHS-R and ghrelin O-acyltransferase (GOAT), the enzyme that promotes the acylation of the third serine residue of ghrelin, are all expressed in pancreatic islets, and this peptide is released into pancreatic microcirculations. Ghrelin inhibits insulin release in mice, rats and humans. The signal transduction mechanisms of ghrelin receptor in islet β-cells are very unique, being distinct from those utilized for GH release. Pharmacological and genetic blockade of islet-derived ghrelin markedly augments glucose-induced insulin release in vitro. Ablation of ghrelin, GHS-R or GOAT enhances insulin release and prevents impaired glucose tolerance in high-fat, diet-induced and leptin-deficient obese models. Thus, manipulation of the insulinostatic function of the ghrelin-GHS-R system, particularly that in islets, could optimize the amount of insulin release to meet the systemic demand. Ghrelin antagonism provides a novel strategy to treat type 2 diabetes with dysregulated insulin release.

  20. Effect of insulin and glucose on adenosine metabolizing enzymes in human B lymphocytes.

    Science.gov (United States)

    Kocbuch, Katarzyna; Sakowicz-Burkiewicz, Monika; Grden, Marzena; Szutowicz, Andrzej; Pawelczyk, Tadeusz

    2009-01-01

    In diabetes several aspects of immunity are altered, including the immunomodulatory action of adenosine. Our study was undertaken to investigate the effect of different glucose and insulin concentrations on activities of adenosine metabolizing enzymes in human B lymphocytes line SKW 6.4. The activity of adenosine deaminase in the cytosolic fraction was very low and was not affected by different glucose concentration, but in the membrane fraction of cells cultured with 25 mM glucose it was decreased by about 35% comparing to the activity in cells maintained in 5 mM glucose, irrespective of insulin concentration. The activities of 5'-nucleotidase (5'-NT) and ecto-5'-NT in SKW 6.4 cells depended on insulin concentration, but not on glucose. Cells cultured with 10(-8) M insulin displayed an about 60% lower activity of cytosolic 5'-NT comparing to cells maintained at 10(-11) M insulin. The activity of ecto-5'-NT was decreased by about 70% in cells cultured with 10(-8) M insulin comparing to cells grown in 10(-11) M insulin. Neither insulin nor glucose had an effect on adenosine kinase (AK) activity in SKW 6.4 cells or in human B cells isolated from peripheral blood. The extracellular level of adenosine and inosine during accelerated catabolism of cellular ATP depended on glucose, but not on insulin concentration. Concluding, our study demonstrates that glucose and insulin differentially affect the activities of adenosine metabolizing enzymes in human B lymphocytes, but changes in those activities do not correlate with the adenosine level in cell media during accelerated ATP catabolism, implying that nucleoside transport is the primary factor determining the extracellular level of adenosine.

  1. Acute effects of ghrelin administration on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Vestergaard, Esben Thyssen; Djurhuus, Christian Born; Gjedsted, Jakob;

    2007-01-01

    CONTEXT: Ghrelin infusion increases plasma glucose and nonesterified fatty acids, but it is uncertain whether this is secondary to the concomitant release of GH. OBJECTIVE: Our objective was to study direct effects of ghrelin on substrate metabolism. DESIGN: This was a randomized, single-blind, p......CONTEXT: Ghrelin infusion increases plasma glucose and nonesterified fatty acids, but it is uncertain whether this is secondary to the concomitant release of GH. OBJECTIVE: Our objective was to study direct effects of ghrelin on substrate metabolism. DESIGN: This was a randomized, single...

  2. Antilipolytic drug boosts glucose metabolism in prostate cancer

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Divilov, Vadim; Koziorowski, Jacek;

    2013-01-01

    The antilipolytic drug Acipimox reduces free fatty acid (FFA) levels in the blood stream. We examined the effect of reduced FFAs on glucose metabolism in androgen-dependent (CWR22Rv1) and androgen-independent (PC3) prostate cancer (PCa) xenografts.......The antilipolytic drug Acipimox reduces free fatty acid (FFA) levels in the blood stream. We examined the effect of reduced FFAs on glucose metabolism in androgen-dependent (CWR22Rv1) and androgen-independent (PC3) prostate cancer (PCa) xenografts....

  3. Glucose regulates lipid metabolism in fasting king penguins.

    Science.gov (United States)

    Bernard, Servane F; Orvoine, Jord; Groscolas, René

    2003-08-01

    This study aims to determine whether glucose intervenes in the regulation of lipid metabolism in long-term fasting birds, using the king penguin as an animal model. Changes in the plasma concentration of various metabolites and hormones, and in lipolytic fluxes as determined by continuous infusion of [2-3H]glycerol and [1-14C]palmitate, were examined in vivo before, during, and after a 2-h glucose infusion under field conditions. All the birds were in the phase II fasting status (large fat stores, protein sparing) but differed by their metabolic and hormonal statuses, being either nonstressed (NSB; n = 5) or stressed (SB; n = 5). In both groups, glucose infusion at 5 mg.kg-1.min-1 induced a twofold increase in glycemia. In NSB, glucose had no effect on lipolysis (maintenance of plasma concentrations and rates of appearance of glycerol and nonesterified fatty acids) and no effect on the plasma concentrations of triacylglycerols (TAG), glucagon, insulin, or corticosterone. However, it limited fatty acid (FA) oxidation, as indicated by a 25% decrease in the plasma level of beta-hydroxybutyrate (beta-OHB). In SB, glucose infusion induced an approximately 2.5-fold decrease in lipolytic fluxes and a large decrease in FA oxidation, as reflected by a 64% decrease in the plasma concentration of beta-OHB. There were also a 35% decrease in plasma TAG, a 6.5- and 2.8-fold decrease in plasma glucagon and corticosterone, respectively, and a threefold increase in insulinemia. These data show that in fasting king penguins, glucose regulates lipid metabolism (inhibition of lipolysis and/or of FA oxidation) and affects hormonal status differently in stressed vs. nonstressed individuals. The results also suggest that in birds, as in humans, the availability of glucose, not of FA, is an important determinant of the substrate mix (glucose vs. FA) that is oxidized for energy production.

  4. HRG-1 enhances cancer cell invasive potential and couples glucose metabolism to cytosolic/extracellular pH gradient regulation by the vacuolar-H(+) ATPase.

    Science.gov (United States)

    Fogarty, F M; O'Keeffe, J; Zhadanov, A; Papkovsky, D; Ayllon, V; O'Connor, R

    2014-09-18

    Haeme-responsive gene (HRG)-1 encodes a 16-kDa transmembrane protein that is induced by insulin-like growth factor-1 (IGF-1) and associates with the vacuolar-(H(+)) ATPase (V-ATPase). We previously reported that HRG-1 is essential for V-ATPase activity in endosomal acidification and receptor trafficking. Here, we show that in highly invasive and migratory cancer cell lines, HRG-1 and the V-ATPase are co-expressed at the plasma membrane, whereas in less invasive cell lines and non-transformed cells HRG-1 over-expression remains confined to intracellular compartments. Stable suppression of HRG-1 in invasive breast cancer MDA-MB-231 cells decreases extracellular pH, cell growth, migration and invasion. Ectopic expression of HRG-1 in non-invasive MCF-7 cells enhances V-ATPase activity, lowers the extracellular pH and increases the pH-dependent activity of MMP2 and MMP9 matrix metalloproteinases. HRG-1 enhances trafficking of the glucose transporter-1 (GLUT-1) with a concomitant increase in glucose uptake and lactate production. HRG-1 also promotes trafficking of the insulin-like growth factor I receptor (IGF-1R), β1-integrin and IGF-1 signalling. Taken together, our findings indicate that HRG-1 expression at the plasma membrane enhances V-ATPase activity, drives glycolytic flux and facilitates cancer cell growth, migration and invasion. Thus, HRG-1 may represent a novel target for selectively disrupting V-ATPase activity and the metastatic potential of cancer cells.

  5. Cerebral glucose metabolism in patients with spasmodic torticollis

    NARCIS (Netherlands)

    MagyarLehmann, S; Antonini, A; Roelcke, U; Maguire, RP; Missimer, J; Leenders, KL

    1997-01-01

    The pathophysiology of spasmodic torticollis is not clear. Basal ganglia dysfunction has been suggested to underlie this clinical syndrome. We studied resting cerebral glucose metabolism in 10 spasmodic torticollis patients and 10 healthy controls by using positron-emission tomography and [F-18]2-fl

  6. Glucose Metabolism via the Entner-Doudoroff Pathway in Campylobacter

    DEFF Research Database (Denmark)

    Vegge, Christina S; Jansen van Rensburg, Melissa J; Rasmussen, Janus J;

    2016-01-01

    Isolates of the zoonotic pathogen Campylobacter are generally considered to be unable to metabolize glucose due to lack of key glycolytic enzymes. However, the Entner-Doudoroff (ED) pathway has been identified in Campylobacter jejuni subsp. doylei and a few C. coli isolates. A systematic search f...

  7. High glucose repatterns human podocyte energy metabolism during differentiation and diabetic nephropathy

    Science.gov (United States)

    Imasawa, Toshiyuki; Obre, Emilie; Bellance, Nadège; Lavie, Julie; Imasawa, Tomoko; Rigothier, Claire; Delmas, Yahsou; Combe, Christian; Lacombe, Didier; Benard, Giovanni; Claverol, Stéphane; Bonneu, Marc; Rossignol, Rodrigue

    2017-01-01

    Podocytes play a key role in diabetic nephropathy pathogenesis, but alteration of their metabolism remains unknown in human kidney. By using a conditionally differentiating human podocyte cell line, we addressed the functional and molecular changes in podocyte energetics during in vitro development or under high glucose conditions. In 5 mM glucose medium, we observed a stepwise activation of oxidative metabolism during cell differentiation that was characterized by peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α)–dependent stimulation of mitochondrial biogenesis and function, with concomitant reduction of the glycolytic enzyme content. Conversely, when podocytes were cultured in high glucose (20 mM), stepwise oxidative phosphorylation biogenesis was aborted, and a glycolytic switch occurred, with consecutive lactic acidosis. Expression of the master regulators of oxidative metabolism transcription factor A mitochondrial, PGC-1α, AMPK, and serine–threonine liver kinase B1 was altered by high glucose, as well as their downstream signaling networks. Focused transcriptomics revealed that myocyte-specific enhancer factor 2C (MEF2C) and myogenic factor 5 (MYF5) expression was inhibited by high glucose levels, and endoribonuclease-prepared small interfering RNA–mediated combined inhibition of those transcription factors phenocopied the glycolytic shift that was observed in high glucose conditions. Accordingly, a reduced expression of MEF2C, MYF5, and PGC-1α was found in kidney tissue sections that were obtained from patients with diabetic nephropathy. These findings obtained in human samples demonstrate that MEF2C-MYF5–dependent bioenergetic dedifferentiation occurs in podocytes that are confronted with a high-glucose milieu.—Imasawa, T., Obre, E., Bellance, N., Lavie, J., Imasawa, T., Rigothier, C., Delmas, Y., Combe, C., Lacombe, D., Benard, G., Claverol, S., Bonneu, M., Rossignol, R. High glucose repatterns human podocyte energy

  8. Muscle glucose metabolism following exercise in the rat

    DEFF Research Database (Denmark)

    Richter, Erik; Garetto, L P; Goodman, M N

    1982-01-01

    Muscle glycogen stores are depleted during exercise and are rapidly repleted during the recovery period. To investigate the mechanism for this phenomenon, untrained male rats were run for 45 min on a motor-driven treadmill and the ability of their muscles to utilize glucose was then assessed during...... in glucose utilization enhanced by prior exercise appeared to be glucose transport across the cell membrane, as in neither control nor exercised rats did free glucose accumulate in the muscle cell. Following exercise, the ability of insulin to stimulate the release of lactate into the perfusate was unaltered......; however its ability to stimulate the incorporation of [(14)C]glucose into glycogen in certain muscles was enhanced. Thus at a concentration of 75 muU/ml insulin stimulated glycogen synthesis eightfold more in the fast-twitch red fibers of the red gastrocnemius than it did in the same muscle...

  9. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  10. Analysis of tumor metabolism reveals mitochondrial glucose oxidation in genetically diverse, human glioblastomas in the mouse brain in vivo

    Science.gov (United States)

    Marin-Valencia, Isaac; Yang, Chendong; Mashimo, Tomoyuki; Cho, Steve; Baek, Hyeonman; Yang, Xiao-Li; Rajagopalan, Kartik N.; Maddie, Melissa; Vemireddy, Vamsidhara; Zhao, Zhenze; Cai, Ling; Good, Levi; Tu, Benjamin P.; Hatanpaa, Kimmo J.; Mickey, Bruce E.; Matés, José M.; Pascual, Juan M.; Maher, Elizabeth A.; Malloy, Craig R.; DeBerardinis, Ralph J.; Bachoo, Robert M.

    2012-01-01

    SUMMARY Dysregulated metabolism is a hallmark of cancer cell lines, but little is known about the fate of glucose and other nutrients in tumors growing in their native microenvironment. To study tumor metabolism in vivo, we used an orthotopic mouse model of primary human glioblastoma (GBM). We infused 13C-labeled nutrients into mice bearing three independent GBM lines, each with a distinct set of mutations. All three lines displayed glycolysis, as expected for aggressive tumors. They also displayed unexpected metabolic complexity, oxidizing glucose via pyruvate dehydrogenase and the citric acid cycle, and using glucose to supply anaplerosis and other biosynthetic activities. Comparing the tumors to surrounding brain revealed obvious metabolic differences, notably the accumulation of a large glutamine pool within the tumors. Many of these same activities were conserved in cells cultured ex vivo from the tumors. Thus GBM cells utilize mitochondrial glucose oxidation during aggressive tumor growth in vivo. PMID:22682223

  11. Bace1 activity impairs neuronal glucose metabolism: rescue by beta-hydroxybutyrate and lipoic acid

    Directory of Open Access Journals (Sweden)

    John A Findlay

    2015-10-01

    Full Text Available Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer’s disease (AD pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP cleaving enzyme 1 (BACE1, responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  12. Glucose Metabolism in Sheep Fed Grass Supplemented with Gliricidia Sepium

    Directory of Open Access Journals (Sweden)

    Y. Widiawati

    2014-12-01

    Full Text Available The limiting factor on improving ruminant production for most of the available feed in developing countries are low in quality. Therefore high fibre diet must be supplemented by high nutritivefeed such as leguminous trees that much available in those regions. Gliricidia sepium was one of very potential candidates. Glucose as a major energy source in fed animals required precursor in form of propionat and amino acids from diet. Those precursors might be supplied by these legume leaves. The aim of this research was to investigate the glucose metabolism in the sheep fed grass supplemented by Gliricidia sepium. Fifteen sheeps (18 months old were used in the experiment. Theseare were divided into three groups that fed by experimental diet of Mitchell grass (MG group, Gliricidia(GS group, and MG supplemented with GS (MGGS group. D-[U-14C]glucoseinfusate was infused continuously through the left jugular venous catheter of each animal to measure glucose metabolism in those sheeps. The measurements were done on feed utilisation and glucose metabolism. The results indicated that there was an improvement in efficiency of feed utilisation in the MGGS group as reflected by lower feed conversion ratio by the group. Plasma glucose concentration profile per unit of OM intake were similar for GS and MGGS groups, but higher than that in the MG group (P<0.01. Glucose entry rate (GER increased in MG group through GS to the MGGS group, while N retention accordingly was increased. It can be concluded that theutilization of GS by the ruminant animal could be improved by feeding it with a low quality feed at a ratio of 40:60 (GS:Low quality feed to achieve an NI:DOMI ratio of 0.03 - 0.04. This improvement would be manifested in increasing DOMI, with subsequent increase in GER or net protein deposition as might be expressed in positive N retention.

  13. Sleep apnea predicts distinct alterations in glucose homeostasis and biomarkers in obese adults with normal and impaired glucose metabolism

    Directory of Open Access Journals (Sweden)

    Hill Nathan R

    2010-12-01

    Full Text Available Abstract Background Notwithstanding previous studies supporting independent associations between obstructive sleep apnea (OSA and prevalence of diabetes, the underlying pathogenesis of impaired glucose regulation in OSA remains unclear. We explored mechanisms linking OSA with prediabetes/diabetes and associated biomarker profiles. We hypothesized that OSA is associated with distinct alterations in glucose homeostasis and biomarker profiles in subjects with normal (NGM and impaired glucose metabolism (IGM. Methods Forty-five severely obese adults (36 women without certain comorbidities/medications underwent anthropometric measurements, polysomnography, and blood tests. We measured fasting serum glucose, insulin, selected cytokines, and calculated homeostasis model assessment estimates of insulin sensitivity (HOMA-IS and pancreatic beta-cell function (HOMA-B. Results Both increases in apnea-hypopnea index (AHI and the presence of prediabetes/diabetes were associated with reductions in HOMA-IS in the entire cohort even after adjustment for sex, race, age, and BMI (P = 0.003. In subjects with NGM (n = 30, OSA severity was associated with significantly increased HOMA-B (a trend towards decreased HOMA-IS independent of sex and adiposity. OSA-related oxyhemoglobin desaturations correlated with TNF-α (r=-0.76; P = 0.001 in women with NGM and with IL-6 (rho=-0.55; P = 0.035 in women with IGM (n = 15 matched individually for age, adiposity, and AHI. Conclusions OSA is independently associated with altered glucose homeostasis and increased basal beta-cell function in severely obese adults with NGM. The findings suggest that moderate to severe OSA imposes an excessive functional demand on pancreatic beta-cells, which may lead to their exhaustion and impaired secretory capacity over time. The two distinct biomarker profiles linking sleep apnea with NGM and IGM via TNF-α and IL-6 have been discerned in our study to suggest that sleep apnea and particularly

  14. Rewiring of embryonic glucose metabolism via suppression of PFK-1 and aldolase during mouse chorioallantoic branching

    Science.gov (United States)

    Sugiura, Yuki; Honda, Kurara; Kondo, Koki; Miura, Masayuki

    2017-01-01

    Adapting the energy metabolism state to changing bioenergetic demands is essential for mammalian development accompanying massive cell proliferation and cell differentiation. However, it remains unclear how developing embryos meet the changing bioenergetic demands during the chorioallantoic branching (CB) stage, when the maternal-fetal exchange of gases and nutrients is promoted. In this study, using metabolome analysis with mass-labeled glucose, we found that developing embryos redirected glucose carbon flow into the pentose phosphate pathway via suppression of the key glycolytic enzymes PFK-1 and aldolase during CB. Concomitantly, embryos exhibited an increase in lactate pool size and in the fractional contribution of glycolysis to lactate biosynthesis. Imaging mass spectrometry visualized lactate-rich tissues, such as the dorsal or posterior neural tube, somites and head mesenchyme. Furthermore, we found that the heterochronic gene Lin28a could act as a regulator of the metabolic changes observed during CB. Perturbation of glucose metabolism rewiring by suppressing Lin28a downregulation resulted in perinatal lethality. Thus, our work demonstrates that developing embryos rewire glucose metabolism following CB for normal development. PMID:28049690

  15. The effect of vagal nerve blockade using electrical impulses on glucose metabolism in nondiabetic subjects

    Directory of Open Access Journals (Sweden)

    Sathananthan M

    2014-07-01

    Full Text Available Matheni Sathananthan,1 Sayeed Ikramuddin,2 James M Swain,3,6 Meera Shah,1 Francesca Piccinini,4 Chiara Dalla Man,4 Claudio Cobelli,4 Robert A Rizza,1 Michael Camilleri,5 Adrian Vella1 1Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA; 2Division of General Surgery, University of Minnesota, Minneapolis, MN, USA; 3Division of General Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA; 4Department of Information Engineering, University of Padua, Padua, Italy; 5Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA; 6Scottsdale Healthcare Bariatric Center, Scottsdale, AZ, USA Purpose: Vagal interruption causes weight loss in humans and decreases endogenous glucose production in animals. However, it is unknown if this is due to a direct effect on glucose metabolism. We sought to determine if vagal blockade using electrical impulses alters glucose metabolism in humans. Patients and methods: We utilized a randomized, cross-over study design where participants were studied after 2 weeks of activation or inactivation of vagal nerve blockade (VNB. Seven obese subjects with impaired fasting glucose previously enrolled in a long-term study to examine the effect of VNB on weight took part. We used a standardized triple-tracer mixed meal to enable measurement of the rate of meal appearance, endogenous glucose production, and glucose disappearance. The 550 kcal meal was also labeled with 111In-diethylene triamine pentaacetic acid (DTPA to measure gastrointestinal transit. Insulin action and ß-cell responsivity indices were estimated using the minimal model. Results: Integrated glucose, insulin, and glucagon concentrations did not differ between study days. This was also reflected in a lack of effect on β-cell responsivity and insulin action. Furthermore, fasting and postprandial endogenous glucose production, integrated meal appearance, and glucose

  16. Implications of Resveratrol on Glucose Uptake and Metabolism

    Directory of Open Access Journals (Sweden)

    David León

    2017-03-01

    Full Text Available Resveratrol—a polyphenol of natural origin—has been the object of massive research in the past decade because of its potential use in cancer therapy. However, resveratrol has shown an extensive range of cellular targets and effects, which hinders the use of the molecule for medical applications including cancer and type 2 diabetes. Here, we review the latest advances in understanding how resveratrol modulates glucose uptake, regulates cellular metabolism, and how this may be useful to improve current therapies. We discuss challenges and findings regarding the inhibition of glucose uptake by resveratrol and other polyphenols of similar chemical structure. We review alternatives that can be exploited to improve cancer therapies, including the use of other polyphenols, or the combination of resveratrol with other molecules and their impact on glucose homeostasis in cancer and diabetes.

  17. Gut microbiota may have influence on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Mikkelsen, Kristian Hallundbæk; Nielsen, Morten Frost; Tvede, Michael

    2013-01-01

    New gene sequencing-based techniques and the large worldwide sequencing capacity have introduced a new era within the field of gut microbiota. Animal and human studies have shown that obesity and type 2 diabetes are associated with changes in the composition of the gut microbiota...... and that prebiotics, antibiotics or faecal transplantation can alter glucose and lipid metabolism. This paper summarizes the latest research regarding the association between gut microbiota, diabetes and obesity and some of the mechanisms by which gut bacteria may influence host metabolism....

  18. Dementia with impaired glucose metabolism in late onset metachromatic leukodystrophy

    DEFF Research Database (Denmark)

    Johannsen, P.; Ehlers, L.; Hansen, Hans Jacob

    2001-01-01

    An unusual case of very-late-onset metachromatic leukodystrophy (MLD) with dementia was studied. The patient was a 41-year-old male who presented with mild dementia and a single generalized tonic clonic seizure. Neuropsychological assessment demonstrated mild amnesia, visuospatial dysfunction and...... was observed using positron emission tomography and fluor-18-labeled fluorodesoxyglucose. The neuropsychological deficits are related to the location of deficits in glucose metabolism....

  19. Metabolic glucose status and pituitary pathology portend therapeutic outcomes in acromegaly.

    Directory of Open Access Journals (Sweden)

    Sonia Cheng

    Full Text Available INTRODUCTION: Acromegaly is frequently associated with impaired glucose tolerance and/or diabetes. To evaluate the relationship between glucose metabolism and acromegaly disease, we evaluated 269 consecutive patients from two referral centres. METHODS: Clinical presentation, pituitary tumor size and invasiveness, and pituitary pathology were captured in a dedicated database. RESULTS: 131 women and 138 men with a mean age of 53.8 years were included. Of these, 201 (74.7% presented with a macroadenoma and 18 (6.7% with a microadenoma. Radiographic invasion was present in 91 cases (33.8%. Mean tumor diameter was 1.86 cm (0.2-4.6. Pituitary histopathologic findings revealed pure GH-producing somatotroph adenomas (SA in 147 patients, prolactin-production by mixed lactotroph (LA and SA or mammosomatotroph adenoma (MSA in 46 [22.4%], acidophil stem cell adenoma in 6 [2.9%], and other diagnoses in 6 [2.9%]. Medical treatment included octreotide in 96 [36.9%] and in combination with pegvisomant or dopamine agonists in 63 [24.2%]. Nearly 80% of patients achieved IGF-1 normalization. Importantly, patients with pure somatotroph adenomas were significantly more likely to present with abnormal glucose metabolism [48.7%] than those with mixed adenomas [9.7%] [p<0.001] independent of GH/IGF-1 levels or tumor invasiveness. Abnormal glucose metabolism and pituitary pathology also remained linked following IGF-1 normalization. Moreover patients with pure SA and abnormal glucose metabolism were significantly (p<0.001 less likely to achieve disease remission despite the same therapeutic strategies. Conversely, patients with mixed adenomas were more likely (OR: 2.766 (95% CI: 1.490-5.136 to achieve disease remission. CONCLUSIONS: Patients with pure somatotroph adenomas are more likely than those with mixed adenomas to exhibit abnormal glucose metabolism.

  20. Danthron activates AMP-activated protein kinase and regulates lipid and glucose metabolism in vitro

    Institute of Scientific and Technical Information of China (English)

    Rong ZHOU; Ling WANG; Xing XU; Jing CHEN; Li-hong HU; Li-li CHEN; Xu SHEN

    2013-01-01

    Aim:To discover the active compound on AMP-activated protein kinase (AMPK) activation and investigate the effects of the active compound 1,8-dihydroxyanthraquinone (danthron) from the traditional Chinese medicine rhubarb on AMPK-mediated lipid and glucose metabolism in vitro.Methods:HepG2 and C2C12 cells were used.Cell viability was determined using MTT assay.Real-time PCR was performed to measure the gene expression.Western blotting assay was applied to investigate the protein phosphorylation level.Enzymatic assay kits were used to detect the total cholesterol (TC),triglyceride (TG) and glucose contents.Results:Danthron (0.1,1,and 10 μmol/L) dose-dependently promoted the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC)in both HepG2 and C2C12 cells.Meanwhile,danthron treatment significantly reduced the lipid synthesis related sterol regulatory element-binding protein 1c (SREBP1c) and fatty acid synthetase (FAS) gene expressions,and the TC and TG levels.In addition,danthron treatment efficiently increased glucose consumption.The actions of danthron on lipid and glucose metabolism were abolished or reversed by co-treatment with the AMPK inhibitor compound C.Conclusion:Danthron effectively reduces intracellular lipid contents and enhanced glucose consumption in vitro via activation of AMPK signaling pathway.

  1. Testing the Role of Myeloid Cell Glucose Flux in Inflammation and Atherosclerosis

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    Tomohiro Nishizawa

    2014-04-01

    Full Text Available Inflammatory activation of myeloid cells is accompanied by increased glycolysis, which is required for the surge in cytokine production. Although in vitro studies suggest that increased macrophage glucose metabolism is sufficient for cytokine induction, the proinflammatory effects of increased myeloid cell glucose flux in vivo and the impact on atherosclerosis, a major complication of diabetes, are unknown. We therefore tested the hypothesis that increased glucose uptake in myeloid cells stimulates cytokine production and atherosclerosis. Overexpression of the glucose transporter GLUT1 in myeloid cells caused increased glycolysis and flux through the pentose phosphate pathway but did not induce cytokines. Moreover, myeloid-cell-specific overexpression of GLUT1 in LDL receptor-deficient mice was ineffective in promoting atherosclerosis. Thus, increased glucose flux is insufficient for inflammatory myeloid cell activation and atherogenesis. If glucose promotes atherosclerosis by increasing cellular glucose flux, myeloid cells do not appear to be the key targets.

  2. Glucose as the Sole Metabolic Fuel: Overcoming a Misconception Using Conceptual Change to Teach the Energy-Yielding Metabolism to Brazilian High School Students

    Science.gov (United States)

    Luz, Mauricio R. M. P.; Oliveira, Gabriel A.; Da Poian, Andrea T.

    2013-01-01

    A misconception regarding the human metabolism has been shown to be widespread among high school students. The students consider glucose as the sole metabolic fuel, disregarding that lipids and amino acids can be oxidized for ATP production by human cells. This misconception seems to be a consequence of formal teaching in grade and high schools.…

  3. Molecular mechanism of hepatitis C virus-induced glucose metabolic disorders

    Directory of Open Access Journals (Sweden)

    Ikuo eShoji

    2012-01-01

    Full Text Available Hepatitis C virus (HCV infection causes not only intrahepatic diseases but also extrahepatic manifestations, including metabolic disorders. Chronic HCV infection is often associated with type 2 diabetes. However, the precise mechanism underlying this association is still unclear. Glucose is transported into hepatocytes via glucose transporter 2 (GLUT2. Hepatocytes play a crucial role in maintaining plasma glucose homeostasis via the gluconeogenic and glycolytic pathways. We have been investigating the molecular mechanism of HCV-related type 2 diabetes using HCV RNA replicon cells and HCV J6/JFH1 system. We found that HCV replication down-regulates cell surface expression of GLUT2 at the transcriptional level. We also found that HCV infection promotes hepatic gluconeogenesis in HCV J6/JFH1-infected Huh-7.5 cells. HCV infection transcriptionally up-regulated the genes for PEPCK and G6Pase, the rate-limiting enzymes for hepatic gluconeogenesis. Gene expression of PEPCK and G6Pase was regulated by the transcription factor forkhead box O1 (FoxO1 in HCV-infected cells. Phosphorylation of FoxO1 at Ser319 was markedly diminished in HCV-infected cells, resulting in increased nuclear accumulation of FoxO1. HCV NS5A protein was directly linked with the FoxO1-dependent increased gluconeogenesis. This paper will discuss the current model of HCV-induced glucose metabolic disorders.

  4. Effect of blueberries and insulin on glucose induced neurotoxicity in brain cells in vitro

    Science.gov (United States)

    Introduction Literature had shown that disruption in glucose metabolism seen in metabolic syndrome maybe responsible for neuronal cell-death. Oxidative stress (OS) and inflammation (INF) triggered by the impaired metabolic process are considered to be the primary factors for the toxic neuronal atmos...

  5. Metabolic profile of normal glucose-tolerant subjects with elevated 1-h plasma glucose values

    Science.gov (United States)

    Pramodkumar, Thyparambil Aravindakshan; Priya, Miranda; Jebarani, Saravanan; Anjana, Ranjit Mohan; Mohan, Viswanathan; Pradeepa, Rajendra

    2016-01-01

    Aim: The aim of this study was to compare the metabolic profiles of subjects with normal glucose tolerance (NGT) with and without elevated 1-h postglucose (1HrPG) values during an oral glucose tolerance test (OGTT). Methodology: The study group comprised 996 subjects without known diabetes seen at tertiary diabetes center between 2010 and 2014. NGT was defined as fasting plasma glucose <100 mg/dl (5.5 mmol/L) and 2-h plasma glucose <140 mg/dl (7.8 mmol/L) after an 82.5 g oral glucose (equivalent to 75 g of anhydrous glucose) OGTT. Anthropometric measurements and biochemical investigations were done using standardized methods. The prevalence rate of generalized and central obesity, hypertension, dyslipidemia, and metabolic syndrome (MS) was determined among the NGT subjects stratified based on their 1HrPG values as <143 mg/dl, ≥143–<155 mg/dl, and ≥155 mg/dl, after adjusting for age, sex, body mass index (BMI), waist circumference, alcohol consumption, smoking, and family history of diabetes. Results: The mean age of the 996 NGT subjects was 48 ± 12 years and 53.5% were male. The mean glycated hemoglobin for subjects with 1HrPG <143 mg/dl was 5.5%, for those with 1HrPG ≥143–<155 mg/dl, 5.6% and for those with 1HrPG ≥155 mg/dl, 5.7%. NGT subjects with 1HrPG ≥143–<155 mg/dl and ≥155 mg/dl had significantly higher BMI, waist circumference, systolic and diastolic blood pressure, triglyceride, total cholesterol/high-density lipoprotein (HDL) ratio, triglyceride/HDL ratio, leukocyte count, and gamma glutamyl aminotransferase (P < 0.05) compared to subjects with 1HrPG <143 mg/dl. The odds ratio for MS for subjects with 1HrPG ≥143 mg/dl was 1.84 times higher compared to subjects with 1HrPG <143 mg/dl taken as the reference. Conclusion: NGT subjects with elevated 1HrPG values have a worse metabolic profile than those with normal 1HrPG during an OGTT. PMID:27730069

  6. Cerebral glucose metabolic abnormality in patients with congenital scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Nam, H. Y.; Seo, G. T.; Lee, J. S.; Kim, S. C.; Kim, I. J.; Kim, Y. K.; Jeon, S. M. [Pusan National University Hospital, Pusan (Korea, Republic of)

    2007-07-01

    A possible association between congenital scoliosis and low mental status has been recognized, but there are no reports describing the mental status or cerebral metabolism in patients with congenital scoliosis in detail. We investigated the mental status using a mini-mental status exam as well as the cerebral glucose metabolism using F-18 fluorodeoxyglucose brain positron emission tomography in 12 patients with congenital scoliosis and compared them with those of 14 age-matched patients with adolescent idiopathic scoliosis. The mean mini-mental status exam score in the congenital scoliosis group was significantly lower than that in the adolescent idiopathic scoliosis group. Group analysis found that various brain areas of patients with congenital scoliosis showed glucose hypometabolisms in the left prefrontal cortex (Brodmann area 10), right orbitofrontal cortex (Brodmann area 11), left dorsolateral prefrontal cortex (Brodmann area 9), left anterior cingulate gyrus (Brodmann area 24) and pulvinar of the left thalamus. From this study, we could find the metabolic abnormalities of brain in patients with congenital scoliosis and suggest the possible role of voxel-based analysis of brain fluorodeoxyglucose positron emission tomography.

  7. Effect of abomasal glucose infusion on splanchnic and whole-body glucose metabolism in periparturient dairy cows

    DEFF Research Database (Denmark)

    Larsen, Mogens; Kristensen, Niels Bastian

    2009-01-01

    Six periparturient Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the hepatic portal vein, hepatic vein, mesenteric vein, and an artery were used to study the effects of abomasal glucose infusion on splanchnic and whole-body glucose metabolism.......Six periparturient Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the hepatic portal vein, hepatic vein, mesenteric vein, and an artery were used to study the effects of abomasal glucose infusion on splanchnic and whole-body glucose metabolism....

  8. Demographic and metabolic characteristics of individuals with progressive glucose tolerance

    Directory of Open Access Journals (Sweden)

    A.L. Mendes

    2009-03-01

    Full Text Available We evaluated changes in glucose tolerance of 17 progressors and 62 non-progressors for 9 years to improve our understanding of the pathogenesis of type 2 diabetes mellitus. Changes in anthropometric measurements and responses to an oral glucose tolerance test (OGTT were analyzed. We identified 14 pairs of individuals, one from each group, who were initially normal glucose tolerant and were matched for gender, age, weight, and girth. We compared initial plasma glucose and insulin curves (from OGTT, insulin secretion (first and second phases and insulin sensitivity indices (from hyperglycemic clamp assay for both groups. In the normal glucose tolerant phase, progressors presented: 1 a higher OGTT blood glucose response with hyperglycemia in the second hour and a similar insulin response vs non-progressors; 2 a reduced first-phase insulin secretion (2.0 ± 0.3 vs 2.3 ± 0.3 pmol/L; P < 0.02 with a similar insulin sensitivity index and a lower disposition index (3.9 ± 0.2 vs 4.1 ± 0.2 µmol·kg-1·min-1 ; P < 0.05 vs non-progressors. After 9 years, both groups presented similar increases in weight and fasting blood glucose levels and progressors had an increased glycemic response at 120 min (P < 0.05 and reduced early insulin response to OGTT (progressors, 1st: 2.10 ± 0.34 vs 2nd: 1.87 ± 0.25 pmol/mmol; non-progressors, 1st: 2.15 ± 0.28 vs 2nd: 2.03 ± 0.39 pmol/mmol; P < 0.05. Theses data suggest that β-cell dysfunction might be a risk factor for type 2 diabetes mellitus.

  9. Glucose metabolism in rats submitted to skeletal muscle denervation

    Directory of Open Access Journals (Sweden)

    Wilton Marlindo Santana Nunes

    2005-07-01

    Full Text Available This study analyzed the local and systemic effects of immobilization by denervation of the skeletal muscle on glucose metabolism. The rats were submitted to section of the right paw sciatic nerve. A reduction was observed in glucose uptake by the isolated soleus muscle of the denervated paw after 3 and 7 days, but not after 28 days in relation to the control animals. There was no difference after 3 and 7 days in glucose uptake by the soleus muscle of the opposite intact paw in relation to the control. There was increased glucose uptake in the same paw 28 days after denervation. The rate of glucose removal in response to exogenous insulin after 28 days of denervation was significantly higher than in control animals and those observed after 3 and 7 days of denervation. These results suggest that immobilization by denervation interfered not only in glucose metabolism in the skeletal muscle involved but also in other tissues.O estudo analisou os efeitos locais e sistêmicos da imobilização por desnervação do músculo esquelético sobre o metabolismo glicidico. Ratos foram submetidos à secção do nervo ciático da pata direita. Observou-se redução da captação de glicose pelo músculo sóleo isolado da pata desnervada após 3 e 7 mas não após 28 dias em relação a animais controle. Não houve diferença após 3 e 7 dias na captação de glicose pelo músculo sóleo da pata contralateral intacta em relação ao controle. Houve aumento da captação de glicose nesta mesma pata 28 dias após a desnervação. A taxa de remoção da glicose em resposta à insulina exógena após 28 dias de desnervação foi significantemente superior à do controle e àquelas observadas após 3 e 7 dias da desnervação. Esses resultados sugerem que a imobilização por desnervação interfere não só no metabolismo da glicose no músculo esquelético envolvido como também em outros tecidos.

  10. Enhanced muscle glucose metabolism after exercise in the rat

    DEFF Research Database (Denmark)

    Garetto, L P; Richter, Erik; Goodman, M N

    1984-01-01

    glycogen was substantially repleted at the time (30 min postexercise) that glucose metabolism was examined. When rats were run at twice the previous rate (36 m/min), muscle glycogen was still substantially diminished 30 min after the run. At this time the previously noted increase in insulin sensitivity...... to near base-line values and only the increase in insulin sensitivity persists. It is proposed that phase I corresponds to the period of rapid glycogen repletion that immediately follows exercise and phase II to the period of supercompensation....

  11. Modeling of Xanthophyllomyces dendrorhous growth on glucose and overflow metabolism in batch and fed-batch cultures for astaxanthin production.

    Science.gov (United States)

    Liu, Yuan-Shuai; Wu, Jian-Yong

    2008-12-01

    An astaxanthin-producing yeast Xanthophyllomyces dendrorhous ENM5 was cultivated in a liquid medium containing 50 g/L glucose as the major carbon source in stirred fermentors (1.5-L working volume) in fully aerobic conditions. Ethanol was produced during the exponential growth phase as a result of overflow metabolism or fermentative catabolism of glucose by yeast cells. After accumulating to a peak of 3.5 g/L, the ethanol was consumed by yeast cells as a carbon source when glucose in the culture was nearly exhausted. High initial glucose concentrations and ethanol accumulation in the culture had inhibitory effects on cell growth. Astaxanthin production was partially associated with cell growth. Based on these culture characteristics, we constructed a modified Monod kinetic model incorporating substrate (glucose) and product (ethanol) inhibition to describe the relationship of cell growth rate with glucose and ethanol concentrations. This kinetic model, coupled with the Luedeking-Piret equation for the astaxanthin production, gave satisfactory prediction of the biomass production, glucose consumption, ethanol formation and consumption, and astaxanthin production in batch cultures over 25-75 g/L glucose concentration ranges. The model was also applied to fed-batch cultures to predict the optimum feeding scheme (feeding glucose and corn steep liquor) for astaxanthin production, leading to a high volumetric yield (28.6 mg/L) and a high productivity (5.36 mg/L/day).

  12. Abnormal Glucose Metabolism in Alzheimer’s Disease: Relation to Autophagy/Mitophagy and Therapeutic Approaches

    Science.gov (United States)

    Banerjee, Kalpita; Munshi, Soumyabrata; Frank, David E.; Gibson, Gary E.

    2015-01-01

    Diminished glucose metabolism accompanies many neurodegenerative diseases including Alzheimer’s disease. An understanding of the relation of these metabolic changes to the disease will enable development of novel therapeutic strategies. Following a metabolic challenge, cells generally conserve energy to preserve viability. This requires activation of many cellular repair/regenerative processes such as mitophagy/autophagy and fusion/fission. These responses may diminish cell function in the long term. Prolonged fission induces mitophagy/autophagy which promotes repair but if prolonged progresses to mitochondrial degradation. Abnormal glucose metabolism alters protein signaling including the release of proteins from the mitochondria or migration of proteins from the cytosol to the mitochondria or nucleus. This overview provides an insight into the different mechanisms of autophagy/mitophagy and mitochondrial dynamics in response to the diminished metabolism that occurs with diseases, especially neurodegenerative diseases such as Alzheimer's disease. The review discusses multiple aspects of mitochondrial responses including different signaling proteins and pathways of mitophagy and mitochondrial biogenesis. Improving cellular bioenergetics and mitochondrial dynamics will alter protein signaling and improve cellular/mitochondrial repair and regeneration. An understanding of these changes will suggest new therapeutic strategies. PMID:26077923

  13. Glucose and fatty acid metabolism in a 3 tissue in-vitro model challenged with normo- and hyperglycaemia.

    Directory of Open Access Journals (Sweden)

    Elisabetta Iori

    Full Text Available Nutrient balance in the human body is maintained through systemic signaling between different cells and tissues. Breaking down this circuitry to its most basic elements and reconstructing the metabolic network in-vitro provides a systematic method to gain a better understanding of how cross-talk between the organs contributes to the whole body metabolic profile and of the specific role of each different cell type. To this end, a 3-way connected culture of hepatocytes, adipose tissue and endothelial cells representing a simplified model of energetic substrate metabolism in the visceral region was developed. The 3-way culture was shown to maintain glucose and fatty acid homeostasis in-vitro. Subsequently it was challenged with insulin and high glucose concentrations to simulate hyperglycaemia. The aim was to study the capacity of the 3-way culture to maintain or restore normal circulating glucose concentrations in response to insulin and to investigate the effects these conditions on other metabolites involved in glucose and lipid metabolism. The results show that the system's metabolic profile changes dramatically in the presence of high concentrations of glucose, and that these changes are modulated by the presence of insulin. Furthermore, we observed an increase in E-selectin levels in hyperglycaemic conditions and increased IL-6 concentrations in insulin-free-hyperglycaemic conditions, indicating, respectively, endothelial injury and proinflammatory stress in the challenged 3-way system.

  14. Metabolic properties of chicken embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Cellular energy metabolism correlates with cell fate,but the metabolic properties of chicken embryonic stem (chES) cells are poorly understood.Using a previously established chES cell model and electron microscopy (EM),we found that undifferentiated chES cells stored glycogen.Additionally,undifferentiated chES cells expressed lower levels of glucose transporter 1 (GLUT1) and phosphofructokinase (PFK) mRNAs but higher levels of hexokinase 1 (HK1) and glycogen synthase (GYS) mRNAs compared with control primary chicken embryonic fibroblast (CEF) cells,suggesting that chES cells direct glucose flux towards the glycogenic pathway.Moreover,we demonstrated that undifferentiated chES cells block gluconeogenic outflow and impede the accumulation of glucose-6-phosphate (G6P) from this pathway,as evidenced by the barely detectable levels of pyruvate carboxylase (PCX) and mitochondrial phosphoenolpyruvate carboxykinase (PCK2) mRNAs.Additionally,cell death occurred in undifferentiated chES cells as shown by Hoechst 33342 and propidium iodide (PI) double staining,but it could be rescued by exogenous G6P.However,we found that differentiated chES cells decreased the glycogen reserve through the use of PAS staining.Moreover,differentiated chES cells expressed higher levels of GLUT1,HK1 and PFK mRNAs,while the level of GYS mRNA remained similar in control CEF cells.These data indicate that undifferentiated chES cells continue to synthesize glycogen from glucose at the expense of G6P,while differentiated chES cells have a decreased glycogen reserve,which suggests that the amount of glycogen is indicative of the chES cell state.

  15. Critical Role of Glucose Metabolism in Rheumatoid Arthritis Fibroblast-like Synoviocytes

    Science.gov (United States)

    Garcia-Carbonell, Ricard; Divakaruni, Ajit S.; Lodi, Alessia; Vicente-Suarez, Ildefonso; Saha, Arindam; Cheroutre, Hilde; Boss, Gerry R.; Tiziani, Stefano; Murphy, Anne N.; Guma, Monica

    2016-01-01

    Objective Up-regulation of glucose metabolism has been implicated not only in tumor cell growth but also in immune cells upon activation. However, little is known about the metabolite profile in rheumatoid arthritis (RA), particularly in fibroblast-like synoviocytes (FLS). This study was undertaken to evaluate whether changes in glucose metabolism in RA FLS could play a role in inflammation and joint damage. Methods Synovium and FLS were obtained from patients with RA and patients with osteoarthritis (OA). The rate of glycolysis after stimulation of FLS with lipopolysaccharide and platelet-derived growth factor BB was measured using glycolysis stress test technology. FLS function was evaluated using a glycolysis inhibitor, 2-deoxy-D-glucose (2-DG). After stimulation of the FLS, a migration scratch assay, MTT assay, and enzyme-linked immunosorbent assay were performed to measure the effect of 2-DG on FLS migration, viability of the FLS, and cytokine secretion, respectively. IRDye 800CW 2-DG was used to assess glucose uptake in the arthritic joints and stromal cells of mice after K/BxN mouse serum transfer. The mice were injected daily, intraperitoneally, with 3-bromopyruvate (BrPa; 5 mg/kg) to assess the effect of inhibition of glycolysis in vivo. Results Compared to human OA FLS, the balance between glycolysis and oxidative phosphorylation was shifted toward glycolysis in RA FLS. Glucose transporter 1 (GLUT1) messenger RNA (mRNA) expression correlated with baseline functions of the RA FLS. Glucose deprivation or incubation of the FLS with glycolytic inhibitors impaired cytokine secretion and decreased the rate of proliferation and migration of the cells. In a mouse model of inflammatory arthritis, GLUT1 mRNA expression in the synovial lining cells was observed, and increased levels of glucose uptake and glycolytic gene expression were detected in the stromal compartment of the arthritic mouse joints. Inhibition of glycolysis by BrPa, administered in vivo

  16. Comprehensive analysis of glucose and xylose metabolism in Escherichia coli under aerobic and anaerobic conditions by (13)C metabolic flux analysis.

    Science.gov (United States)

    Gonzalez, Jacqueline E; Long, Christopher P; Antoniewicz, Maciek R

    2017-01-01

    Glucose and xylose are the two most abundant sugars derived from the breakdown of lignocellulosic biomass. While aerobic glucose metabolism is relatively well understood in E. coli, until now there have been only a handful of studies focused on anaerobic glucose metabolism and no (13)C-flux studies on xylose metabolism. In the absence of experimentally validated flux maps, constraint-based approaches such as MOMA and RELATCH cannot be used to guide new metabolic engineering designs. In this work, we have addressed this critical gap in current understanding by performing comprehensive characterizations of glucose and xylose metabolism under aerobic and anaerobic conditions, using recent state-of-the-art techniques in (13)C metabolic flux analysis ((13)C-MFA). Specifically, we quantified precise metabolic fluxes for each condition by performing parallel labeling experiments and analyzing the data through integrated (13)C-MFA using the optimal tracers [1,2-(13)C]glucose, [1,6-(13)C]glucose, [1,2-(13)C]xylose and [5-(13)C]xylose. We also quantified changes in biomass composition and confirmed turnover of macromolecules by applying [U-(13)C]glucose and [U-(13)C]xylose tracers. We demonstrated that under anaerobic growth conditions there is significant turnover of lipids and that a significant portion of CO2 originates from biomass turnover. Using knockout strains, we also demonstrated that β-oxidation is critical for anaerobic growth on xylose. Quantitative analysis of co-factor balances (NADH/FADH2, NADPH, and ATP) for different growth conditions provided new insights regarding the interplay of energy and redox metabolism and the impact on E. coli cell physiology.

  17. Cerebral glucose metabolism in neurofibromatosis type 1 assessed with [18F]-2-fluoro-2-deoxy-D-glucose and PET.

    OpenAIRE

    Balestri, P; Lucignani, G; Fois, A.; Magliani, L; Calistri, L; Grana, C.; Di Bartolo, R M; Perani, D; Fazio, F.

    1994-01-01

    Cerebral PET with [18F]-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This fi...

  18. Endothelial cell and platelet bioenergetics: effect of glucose and nutrient composition.

    Directory of Open Access Journals (Sweden)

    Brian D Fink

    Full Text Available It has been suggested that cells that are independent of insulin for glucose uptake, when exposed to high glucose or other nutrient concentrations, manifest enhanced mitochondrial substrate oxidation with consequent enhanced potential and generation of reactive oxygen species (ROS; a paradigm that could predispose to vascular complications of diabetes. Here we exposed bovine aortic endothelial (BAE cells and human platelets to variable glucose and fatty acid concentrations. We then examined oxygen consumption and acidification rates using recently available technology in the form of an extracellular oxygen and proton flux analyzer. Acute or overnight exposure of confluent BAE cells to glucose concentrations from 5.5 to 25 mM did not enhance or change the rate of oxygen consumption (OCR under basal conditions, during ATP synthesis, or under uncoupled conditions. Glucose also did not alter OCR in sub-confluent cells, in cells exposed to low serum, or in cells treated with added pyruvate. Likewise, overnight exposure to fatty acids of varying saturation had no such effects. Overnight exposure of BAE cells to low glucose concentration decreased maximal uncoupled respiration, but not basal or ATP related oxygen consumption. Labeled glucose oxidation to CO(2 increased, but only marginally after high glucose exposure while oleate oxidation to CO(2 decreased. Overnight exposure to linolenic acid, but not oleic or linoleic acid increased extracellular acidification consistent with enhanced glycolytic metabolism. We were unable to detect an increase in production of reactive oxygen species (ROS from BAE cells exposed to high medium glucose. Like BAE cells, exposure of human platelets to glucose did not increase oxygen consumption. As opposed to BAE cells, platelet mitochondria demonstrate less respiratory reserve capacity (beyond that needed for basal metabolism. Our data do not support the concept that exposure to high glucose or fatty acids accelerates

  19. Lymphocyte Glucose and Glutamine Metabolism as Targets of the Anti-Inflammatory and Immunomodulatory Effects of Exercise

    Directory of Open Access Journals (Sweden)

    Frederick Wasinski

    2014-01-01

    Full Text Available Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight association between metabolism and function in these cells was suggested to introduce the possibility of several pathologies resulting from the inability of lymphocytes to meet their nutrient demands under a given condition. In fact, disruptions in lymphocyte metabolism and function have been observed in different inflammatory, metabolic, and autoimmune pathologies. Regular physical exercise and physical activity offer protection against several chronic pathologies, and this benefit has been associated with the anti-inflammatory and immunomodulatory effects of exercise/physical activity. Chronic exercise induces changes in lymphocyte functionality and substrate metabolism. In the present review, we discuss whether the beneficial effects of exercise on lymphocyte function in health and disease are associated with modulation of the glucose and glutamine metabolic pathways.

  20. Berberine Improves Glucose Metabolism through Induction of Glycolysis

    OpenAIRE

    Yin, Jun; Gao, Zhanguo; Liu, Dong; Liu, Zhijun; Ye, Jianping

    2007-01-01

    Berberine, a botanical alkaloid used to control blood glucose in type 2 diabetes in China, has been reported to activate AMPK recently. However, it is not clear how AMPK is activated by berberine. In this study, activity and action mechanism of berberine were investigated in vivo and in vitro. In dietary obese rats, berberine increased insulin sensitivity after five week administration. Fasting insulin and HOMA-IR were decreased by 46% and 48% in the rats, respectively. In cell lines includin...

  1. Interpretation of metabolic memory phenomenon using a physiological systems model: What drives oxidative stress following glucose normalization?

    Science.gov (United States)

    Voronova, Veronika; Zhudenkov, Kirill; Helmlinger, Gabriel; Peskov, Kirill

    2017-01-01

    Hyperglycemia is generally associated with oxidative stress, which plays a key role in diabetes-related complications. A complex, quantitative relationship has been established between glucose levels and oxidative stress, both in vitro and in vivo. For example, oxidative stress is known to persist after glucose normalization, a phenomenon described as metabolic memory. Also, uncontrolled glucose levels appear to be more detrimental to patients with diabetes (non-constant glucose levels) vs. patients with high, constant glucose levels. The objective of the current study was to delineate the mechanisms underlying such behaviors, using a mechanistic physiological systems modeling approach that captures and integrates essential underlying pathophysiological processes. The proposed model was based on a system of ordinary differential equations. It describes the interplay between reactive oxygen species production potential (ROS), ROS-induced cell alterations, and subsequent adaptation mechanisms. Model parameters were calibrated using different sources of experimental information, including ROS production in cell cultures exposed to various concentration profiles of constant and oscillating glucose levels. The model adequately reproduced the ROS excess generation after glucose normalization. Such behavior appeared to be driven by positive feedback regulations between ROS and ROS-induced cell alterations. The further oxidative stress-related detrimental effect as induced by unstable glucose levels can be explained by inability of cells to adapt to dynamic environment. Cell adaptation to instable high glucose declines during glucose normalization phases, and further glucose increase promotes similar or higher oxidative stress. In contrast, gradual ROS production potential decrease, driven by adaptation, is observed in cells exposed to constant high glucose. PMID:28178319

  2. Resistance to chemotherapy is associated with altered glucose metabolism in acute myeloid leukemia

    Science.gov (United States)

    SONG, KUI; LI, MIN; XU, XIAOJUN; XUAN, LI; HUANG, GUINIAN; LIU, QIFA

    2016-01-01

    Altered glucose metabolism has been described as a cause of chemoresistance in multiple tumor types. The present study aimed to identify the expression profile of glucose metabolism in drug-resistant acute myeloid leukemia (AML) cells and provide potential strategies for the treatment of drug-resistant AML. Bone marrow and serum samples were obtained from patients with AML that were newly diagnosed or had relapsed. The messenger RNA expression of hypoxia inducible factor (HIF)-1α, glucose transporter (GLUT)1, and hexokinase-II was measured by quantitative polymerase chain reaction. The levels of LDH and β subunit of human F1-F0 adenosine triphosphate synthase (β-F1-ATPase) were detected by enzyme-linked immunosorbent and western blot assays. The HL-60 and HL-60/ADR cell lines were used to evaluate glycolytic activity and effect of glycolysis inhibition on cellular proliferation and apoptosis. Drug-resistant HL-60/ADR cells exhibited a significantly increased level of glycolysis compared with the drug-sensitive HL-60 cell line. The expression of HIF-1α, hexokinase-II, GLUT1 and LDH were increased in AML patients with no remission (NR), compared to healthy control individuals and patients with complete remission (CR) and partial remission. The expression of β-F1-ATPase in patients with NR was decreased compared with the expression in the CR group. Treatment of HL-60/ADR cells with 2-deoxy-D-glucose or 3-bromopyruvate increased in vitro sensitivity to Adriamycin (ADR), while treatment of HL-60 cells did not affect drug cytotoxicity. Subsequent to treatment for 24 h, apoptosis in these two cell lines showed no significant difference. However, glycolytic inhibitors in combination with ADR increased cellular necrosis. These findings indicate that increased glycolysis and low efficiency of oxidative phosphorylation may contribute to drug resistance. Targeting glycolysis is a viable strategy for modulating chemoresistance in AML. PMID:27347147

  3. Decreased cerebral glucose metabolism associated with mental deterioration in multi-infarct dementia

    Energy Technology Data Exchange (ETDEWEB)

    Meguro, K. (Tohoku Univ. School of Medicine (Japan). Dept. of Geriatric Medicine Miyama Hospital (Japan)); Doi, C. (Tohoku Univ. School of Literature (Japan). Dept. of Psychology); Yamaguchi, T.; Sasaki, H. (Tohoku Univ. School of Medicine (Japan). Dept. of Geriatric Medicine); Matsui, H.; Yamada, K. (Tohoku Univ. (Japan). Research Inst. for Tuberculosis and Cancer); Kinomura, S. (Miyama Hospital (Japan) Tohoku Univ. (Japan). Research Inst. for Tuberculosis and Cancer); Itoh, M. (Tohoku Univ. School of Medicine (Japan). Cyclotron Radioisotope Center)

    1991-08-01

    Cerebral glucose metabolism of 18 patients with multi-infarct dementia (MID) and 10 age-matched normal subjects were examined with positron emission tomography and the {sup 18}-F-fluoro-deoxy-glucose technique. MID patients had significantly lower glucose metabolsim in all the grey matter regions measured and were also characterized by more individuality in metabolic pattern. MID patients were also evaluated as to intelligence quotient (IQ). A positive correlation between IQ as shown by the Tanaka-Binet test and glucose metabolism for the entire grey matter was found. The clinical applicability of this test for predicting cerebral metabolism is discussed. (orig.).

  4. Fast dynamic response of the fermentative metabolism of Escherichia coli to aerobic and anaerobic glucose pulses.

    Science.gov (United States)

    Lara, Alvaro R; Taymaz-Nikerel, Hilal; Mashego, Mlawule R; van Gulik, Walter M; Heijnen, Joseph J; Ramírez, Octavio T; van Winden, Wouter A

    2009-12-15

    The response of Escherichia coli cells to transient exposure (step increase) in substrate concentration and anaerobiosis leading to mixed-acid fermentation metabolism was studied in a two-compartment bioreactor system consisting of a stirred tank reactor (STR) connected to a mini-plug-flow reactor (PFR: BioScope, 3.5 mL volume). Such a system can mimic the situation often encountered in large-scale, fed-batch bioreactors. The STR represented the zones of a large-scale bioreactor that are far from the point of substrate addition and that can be considered as glucose limited, whereas the PFR simulated the region close to the point of substrate addition, where glucose concentration is much higher than in the rest of the bioreactor. In addition, oxygen-poor and glucose-rich regions can occur in large-scale bioreactors. The response of E. coli to these large-scale conditions was simulated by continuously pumping E. coli cells from a well stirred, glucose limited, aerated chemostat (D = 0.1 h(-1)) into the mini-PFR. A glucose pulse was added at the entrance of the PFR. In the PFR, a total of 11 samples were taken in a time frame of 92 s. In one case aerobicity in the PFR was maintained in order to evaluate the effects of glucose overflow independently of oxygen limitation. Accumulation of acetate and formate was detected after E. coli cells had been exposed for only 2 s to the glucose-rich (aerobic) region in the PFR. In the other case, the glucose pulse was also combined with anaerobiosis in the PFR. Glucose overflow combined with anaerobiosis caused the accumulation of formate, acetate, lactate, ethanol, and succinate, which were also detected as soon as 2 s after of exposure of E. coli cells to the glucose and O(2) gradients. This approach (STR-mini-PFR) is useful for a better understanding of the fast dynamic phenomena occurring in large-scale bioreactors and for the design of modified strains with an improved behavior under large-scale conditions.

  5. A comprehensive metabolic profile of cultured astrocytes using isotopic transient metabolic flux analysis and 13C-labeled glucose

    Directory of Open Access Journals (Sweden)

    Ana I Amaral

    2011-09-01

    Full Text Available Metabolic models have been used to elucidate important aspects of brain metabolism in recent years. This work applies for the first time the concept of isotopic transient 13C metabolic flux analysis (MFA to estimate intracellular fluxes of cultured astrocytes. This methodology comprehensively explores the information provided by 13C labeling time-courses of intracellular metabolites after administration of a 13C labeled substrate. Cells were incubated with medium containing [1-13C]glucose for 24 h and samples of cell supernatant and extracts collected at different time-points were then analyzed by mass spectrometry and/or HPLC. Metabolic fluxes were estimated by fitting a carbon labeling network model to isotopomer profiles experimentally determined. Both the fast isotopic equilibrium of glycolytic metabolite pools and the slow labeling dynamics of TCA cycle intermediates are described well by the model. The large pools of glutamate and aspartate which are linked to the TCA cycle via reversible aminotransferase reactions are likely to be responsible for the observed delay in equilibration of TCA cycle intermediates. Furthermore, it was estimated that 11% of the glucose taken up by astrocytes was diverted to the pentose phosphate pathway. In addition, considerable fluxes through pyruvate carboxylase (PC (PC/pyruvate dehydrogenase (PDH ratio = 0.5, malic enzyme (5% of the total pyruvate production and catabolism of branched-chained amino acids (contributing with ~40% to total acetyl-CoA produced confirmed the significance of these pathways to astrocytic metabolism. Consistent with the need of maintaining cytosolic redox potential, the fluxes through the malate-aspartate shuttle and the PDH pathway were comparable. Finally, the estimated glutamate/α-ketoglutarate exchange rate (~0.7 µmol.mg prot-1.h-1 was similar to the TCA cycle flux. In conclusion, this work demonstrates the potential of isotopic transient MFA for a comprehensive analysis of

  6. The Role of Glucose Metabolism on Porcine Oocyte Cytoplasmic Maturation and Its Possible Mechanisms

    Science.gov (United States)

    Kwon, Jeong-Woo; Jin, Yong-Xun; Park, Shun-Ha; Wang, Hai-Yang; Sun, Tian-Yi; Zhang, Jia-Bao; Kim, Nam-Hyung

    2016-01-01

    In the present study, we investigated the potential role of glucose and pyruvate in the cytoplasmic maturation of porcine oocytes by investigating the effect of glucose and/or pyruvate supplementation, in the presence or absence of 10% porcine follicular fluid (PFF), on meiotic maturation and subsequent embryo development. In the absence of 10% PFF, without exogenous addition of glucose and pyruvate, the medium seemed unable to support maturation. In the presence of 10% PFF, the addition of 5.6 mM glucose and/or 2 mM pyruvate during in vitro maturation of cumulus enclosed oocytes increased MII oocyte and blastocyst rates. In contrast, oocytes denuded of cumulus cells were not able to take full advantage of the glucose in the medium, as only pyruvate was able to increase the MII rate and the subsequent early embryo developmental ability. Treatment of cumulus enclosed oocytes undergoing maturation with 200 μM dehydroepiandrosterone (DHEA), a pentose phosphate pathway inhibitor, or 2 μM iodoacetate (IA), a glycolysis inhibitor, significantly reduced GHS, intra-oocyte ATP, maternal gene expression, and MPF activity levels. DHEA was also able to increase ROS and reduce the levels of NADPH. Moreover, blastocysts of the DHEA- or IA-treated groups presented higher apoptosis rates and markedly lower cell proliferation cell rates than those of the non-treated group. In conclusion, our results suggest that oocytes maturing in the presence of 10% PFF can make full use of energy sources through glucose metabolism only when they are accompanied by cumulus cells, and that pentose phosphate pathway (PPP) and glycolysis promote porcine oocyte cytoplasmic maturation by supplying energy, regulating maternal gene expression, and controlling MPF activity. PMID:27997591

  7. Metabolic Effects of Glucose-Fructose Co-Ingestion Compared to Glucose Alone during Exercise in Type 1 Diabetes

    Science.gov (United States)

    Bally, Lia; Kempf, Patrick; Zueger, Thomas; Speck, Christian; Pasi, Nicola; Ciller, Carlos; Feller, Katrin; Loher, Hannah; Rosset, Robin; Wilhelm, Matthias; Boesch, Chris; Buehler, Tania; Dokumaci, Ayse S.; Tappy, Luc; Stettler, Christoph

    2017-01-01

    This paper aims to compare the metabolic effects of glucose-fructose co-ingestion (GLUFRU) with glucose alone (GLU) in exercising individuals with type 1 diabetes mellitus. Fifteen male individuals with type 1 diabetes (HbA1c 7.0% ± 0.6% (53 ± 7 mmol/mol)) underwent a 90 min iso-energetic continuous cycling session at 50% VO2max while ingesting combined glucose-fructose (GLUFRU) or glucose alone (GLU) to maintain stable glycaemia without insulin adjustment. GLUFRU and GLU were labelled with 13C-fructose and 13C-glucose, respectively. Metabolic assessments included measurements of hormones and metabolites, substrate oxidation, and stable isotopes. Exogenous carbohydrate requirements to maintain stable glycaemia were comparable between GLUFRU and GLU (p = 0.46). Fat oxidation was significantly higher (5.2 ± 0.2 vs. 2.6 ± 1.2 mg·kg−1·min−1, p 0.05 for all). Glucose and insulin levels, and total glucose appearance and disappearance were comparable between interventions. Glucose-fructose co-ingestion may have a beneficial impact on fuel metabolism in exercising individuals with type 1 diabetes without insulin adjustment, by increasing fat oxidation whilst sparing glycogen. PMID:28230765

  8. Metabolic flux profiling of recombinant protein secreting Pichia pastoris growing on glucose:methanol mixtures

    Directory of Open Access Journals (Sweden)

    Jordà Joel

    2012-05-01

    Full Text Available Abstract Background The methylotrophic yeast Pichia pastoris has emerged as one of the most promising yeast hosts for the production of heterologous proteins. Mixed feeds of methanol and a multicarbon source instead of methanol as sole carbon source have been shown to improve product productivities and alleviate metabolic burden derived from protein production. Nevertheless, systematic quantitative studies on the relationships between the central metabolism and recombinant protein production in P. pastoris are still rather limited, particularly when growing this yeast on mixed carbon sources, thus hampering future metabolic network engineering strategies for improved protein production. Results The metabolic flux distribution in the central metabolism of P. pastoris growing on a mixed feed of glucose and methanol was analyzed by Metabolic Flux Analysis (MFA using 13C-NMR-derived constraints. For this purpose, we defined new flux ratios for methanol assimilation pathways in P. pastoris cells growing on glucose:methanol mixtures. By using this experimental approach, the metabolic burden caused by the overexpression and secretion of a Rhizopus oryzae lipase (Rol in P. pastoris was further analyzed. This protein has been previously shown to trigger the unfolded protein response in P. pastoris. A series of 13C-tracer experiments were performed on aerobic chemostat cultivations with a control and two different Rol producing strains growing at a dilution rate of 0.09 h−1 using a glucose:methanol 80:20 (w/w mix as carbon source. The MFA performed in this study reveals a significant redistristribution of carbon fluxes in the central carbon metabolism when comparing the two recombinant strains vs the control strain, reflected in increased glycolytic, TCA cycle and NADH regeneration fluxes, as well as higher methanol dissimilation rates. Conclusions Overall, a further 13C-based MFA development to characterise the central metabolism of methylotrophic

  9. Vitamin C inhibits leptin secretion and some glucose/lipid metabolic pathways in primary rat adipocytes.

    Science.gov (United States)

    Garcia-Diaz, D F; Campion, J; Milagro, F I; Boque, N; Moreno-Aliaga, M J; Martinez, J A

    2010-07-01

    Antioxidant-based treatments are emerging as an interesting approach to possibly counteract obesity fat accumulation complications, since this is accompanied by an increased systemic oxidative stress. The aim of this study was to analyze specific metabolic effects of vitamin C (VC) on epididymal primary rat adipocytes. Cells were isolated and incubated for 72 h in culture medium, in the absence or presence of 1.6 nM insulin, within a range of VC concentrations (5-1000 microM). Glucose- and lipid-related variables as well as the secretion/expression patterns of several obesity-related genes were assessed. It was observed that VC dose dependently inhibited glucose uptake and lactate production, and also reduced glycerol release in both control and insulin-treated cells. Also, VC caused a dramatic concentration-dependent fall in leptin secretion especially in insulin-stimulated cells. In addition, VC (200 microM) induced Cdkn1a and Casp8, partially inhibited Irs3, and together with insulin drastically reduced Gpdh (listed as Gpd1 in the MGI database) gene expressions. Finally, VC and insulin down-regulatory effects were observed on extracellular and intracellular reactive oxygen species production respectively. In summary, this experimental assay describes a specific effect of VC in isolated rat adipocytes on glucose and fat metabolism, and on the secretion/expression of important obesity-related proteins.

  10. Renal Denervation Normalizes Arterial Pressure With No Effect on Glucose Metabolism or Renal Inflammation in Obese Hypertensive Mice.

    Science.gov (United States)

    Asirvatham-Jeyaraj, Ninitha; Fiege, Jessica K; Han, Ruijun; Foss, Jason; Banek, Christopher T; Burbach, Brandon J; Razzoli, Maria; Bartolomucci, Alessandro; Shimizu, Yoji; Panoskaltsis-Mortari, Angela; Osborn, John W

    2016-10-01

    Hypertension often occurs in concurrence with obesity and diabetes mellitus, commonly referred to as metabolic syndrome. Renal denervation (RDNx) lowers arterial pressure (AP) and improves glucose metabolism in drug-resistant hypertensive patients with high body mass index. In addition, RDNx has been shown to reduce renal inflammation in the mouse model of angiotensin II hypertension. The present study tested the hypothesis that RDNx reduces AP and renal inflammation and improves glucose metabolism in obesity-induced hypertension. Eight-week-old C57BL/6J mice were fed either a low-fat diet (10 kcal%) or a high-fat diet (45 kcal%) for 10 weeks. Body weight, food intake, fasting blood glucose, and glucose metabolism (glucose tolerance test) were measured. In a parallel study, radiotelemeters were implanted in mice for AP measurement. High fat-fed C57BL/6J mice exhibited an inflammatory and metabolic syndrome phenotype, including increased fat mass, increased AP, and hyperglycemia compared with low-fat diet mice. RDNx, but not Sham surgery, normalized AP in high-fat diet mice (115.8±1.5 mm Hg in sham versus 96.6±6.7 mm Hg in RDNx). RDNx had no significant effect on AP in low-fat diet mice. Also, RDNx had no significant effect on glucose metabolism or renal inflammation as measured by the number of CD8, CD4, and T helper cells or levels of inflammatory cytokines in the kidneys. These results indicate that although renal nerves play a role in obesity-induced hypertension, they do not contribute to impaired glucose metabolism or renal inflammation in this model.

  11. Epithelial and Mesenchymal Tumor Compartments Exhibit In Vivo Complementary Patterns of Vascular Perfusion and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Mirco Galiè

    2007-11-01

    Full Text Available Glucose transport and consumption are increased in tumors, and this is considered a diagnostic index of malignancy. However, there is recent evidence that carcinoma-associated stromal cells are capable of aerobic metabolism with low glucose consumption, at least partly because of their efficient vascular supply. In the present study, using dynamic contrast-enhanced magnetic resonance imaging and [F-18]fluorodeoxyglucose (FDG positron emission tomography (PET, we mapped in vivo the vascular supply and glucose metabolism in syngeneic experimental models of carcinoma and mesenchymal tumor. We found that in both tumor histotypes, regions with high vascular perfusion exhibited a significantly lower FDG uptake. This reciprocity was more conspicuous in carcinomas than in mesenchymal tumors, and regions with a high-vascular/low-FDG uptake pattern roughly overlapped with a stromal capsule and intratumoral large connectival septa. Accordingly, mesenchymal tumors exhibited a higher vascular perfusion and a lower FDG uptake than carcinomas. Thus, we provide in vivo evidence of vascular/metabolic reciprocity between epithelial and mesenchymal histotypes in tumors, suggesting a new intriguing aspect of epithelial-stromal interaction. Our results suggests that FDG-PET-based clinical analysis can underestimate the malignity or tumor extension of carcinomas exhibiting any trait of “mesenchymalization” such as desmoplasia or epithelial-mesenchymal transition.

  12. Metabolic Control of Type 2 Diabetes by Targeting the GLUT4 Glucose Transporter: Intervention Approaches.

    Science.gov (United States)

    Alam, Fahmida; Islam, Md Asiful; Khalil, Md Ibrahim; Gan, Siew Hua

    2016-01-01

    Type 2 diabetes mellitus (T2DM), the most common form of diabetes, is characterized by insulin resistance in the hepatic and peripheral tissues. Glucose transporter 4 (GLUT4) plays a major role in the pathophysiology of T2DM. Its defective expression or translocation to the peripheral cell plasma membrane in T2DM patients hinders the entrance of glucose into the cell for energy production. In addition to suitable drugs, an appropriate diet and/or exercise can be implemented to target the increase in GLUT4 expression, GLUT4 concentrations and GLUT4 translocation to the cell surface when managing the glucose metabolism of T2DM patients. In this review, we discussed successful intervention strategies that were individually administered or coupled with diet and/or exercise and affected the expression and translocation of GLUT4 in T2DM while reducing the excess glucose load from the blood. Additionally, some potentially good synthetic and natural compounds, which can activate the insulin-independent GLUT4 signaling pathways for the efficient management of T2DM, are highlighted as possible targets or emerging alternative sources for future anti-diabetic drug development.

  13. Glucose-ABL1-TOR Signaling Modulates Cell Cycle Tuning to Control Terminal Appressorial Cell Differentiation

    Science.gov (United States)

    2017-01-01

    The conserved target of rapamycin (TOR) pathway integrates growth and development with available nutrients, but how cellular glucose controls TOR function and signaling is poorly understood. Here, we provide functional evidence from the devastating rice blast fungus Magnaporthe oryzae that glucose can mediate TOR activity via the product of a novel carbon-responsive gene, ABL1, in order to tune cell cycle progression during infection-related development. Under nutrient-free conditions, wild type (WT) M. oryzae strains form terminal plant-infecting cells (appressoria) at the tips of germ tubes emerging from three-celled spores (conidia). WT appressorial development is accompanied by one round of mitosis followed by autophagic cell death of the conidium. In contrast, Δabl1 mutant strains undergo multiple rounds of accelerated mitosis in elongated germ tubes, produce few appressoria, and are abolished for autophagy. Treating WT spores with glucose or 2-deoxyglucose phenocopied Δabl1. Inactivating TOR in Δabl1 mutants or glucose-treated WT strains restored appressorium formation by promoting mitotic arrest at G1/G0 via an appressorium- and autophagy-inducing cell cycle delay at G2/M. Collectively, this work uncovers a novel glucose-ABL1-TOR signaling axis and shows it engages two metabolic checkpoints in order to modulate cell cycle tuning and mediate terminal appressorial cell differentiation. We thus provide new molecular insights into TOR regulation and cell development in response to glucose. PMID:28072818

  14. Delivery-corrected imaging of fluorescently-labeled glucose reveals distinct metabolic phenotypes in murine breast cancer.

    Directory of Open Access Journals (Sweden)

    Amy E Frees

    Full Text Available When monitoring response to cancer therapy, it is important to differentiate changes in glucose tracer uptake caused by altered delivery versus a true metabolic shift. Here, we propose an optical imaging method to quantify glucose uptake and correct for in vivo delivery effects. Glucose uptake was measured using a fluorescent D-glucose derivative 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-ylAmino-2-deoxy-D-glucose (2-NBDG in mice implanted with dorsal skin flap window chambers. Additionally, vascular oxygenation (SO2 was calculated using only endogenous hemoglobin contrast. Results showed that the delivery factor proposed for correction, "RD", reported on red blood cell velocity and injected 2-NBDG dose. Delivery-corrected 2-NBDG uptake (2-NBDG60/RD inversely correlated with blood glucose in normal tissue, indicating sensitivity to glucose demand. We further applied our method in metastatic 4T1 and nonmetastatic 4T07 murine mammary adenocarcinomas. The ratio 2-NBDG60/RD was increased in 4T1 tumors relative to 4T07 tumors yet average SO2 was comparable, suggesting a shift toward a "Warburgian" (aerobic glycolysis metabolism in the metastatic 4T1 line. In heterogeneous regions of both 4T1 and 4T07, 2-NBDG60/RD increased slightly but significantly as vascular oxygenation decreased, indicative of the Pasteur effect in both tumors. These data demonstrate the utility of delivery-corrected 2-NBDG and vascular oxygenation imaging for differentiating metabolic phenotypes in vivo.

  15. Unmasking Glucose Metabolism Alterations in Stable Renal Transplant Recipients: A Multicenter Study

    Science.gov (United States)

    Delgado, Patricia; Diaz, Juan Manuel; Silva, Irene; Osorio, José M.; Osuna, Antonio; Bayés, Beatriz; Lauzurica, Ricardo; Arellano, Edgar; Campistol, Jose Maria; Dominguez, Rosa; Gómez-Alamillo, Carlos; Ibernon, Meritxell; Moreso, Francisco; Benitez, Rocio; Lampreave, Ildefonso; Porrini, Esteban; Torres, Armando

    2008-01-01

    Background and objectives: Emerging information indicates that glucose metabolism alterations are common after renal transplantation and are associated with carotid atheromatosis. The aims of this study were to investigate the prevalence of different glucose metabolism alterations in stable recipients as well as the factors related to the condition. Design, setting, participants, & measurements: A multicenter, cross-sectional study was conducted of 374 renal transplant recipients without pre- or posttransplantation diabetes. A standard 75-g oral glucose tolerance test was performed. Results: Glucose metabolism alterations were present in 119 (31.8%) recipients: 92 (24.6%) with an abnormal oral glucose tolerance test and 27 (7.2%) with isolated impaired fasting glucose. The most common disorder was impaired glucose tolerance (17.9%), and an abnormal oral glucose tolerance test was observed for 21.5% of recipients with a normal fasting glucose. By multivariate analysis, age, prednisone dosage, triglyceride/high-density lipoprotein cholesterol ratio, and β blocker use were shown to be factors related to glucose metabolism alterations. Remarkably, triglyceride levels, triglyceride/high-density lipoprotein cholesterol ratio, and the proportion of recipients with impaired fasting glucose were already higher throughout the first posttransplantation year in recipients with a current glucose metabolism alteration as compared with those without the condition. Conclusions: Glucose metabolism alterations are common in stable renal transplant recipients, and an oral glucose tolerance test is required for its detection. They are associated with a worse metabolic profile, which is already present during the first posttransplantation year. These findings may help planning strategies for early detection and intervention. PMID:18322043

  16. 正常糖代谢肥胖女性体成分改变及β细胞功能分析%Association of body composition and β-cell function in obese females with normal glucose metabolism

    Institute of Scientific and Technical Information of China (English)

    严孙杰; 沈喜妹; 颜晓芳; 易如海; 吴佩文; 杨立勇; 张松菁

    2009-01-01

    Objective To explore the relationship between body composition and β-cell function in obese females with normal glucose metabolism. Methods Seventy-five obese women with normal blood glucose and without family history of diabetes were investigated. They were assigned to 4 groups based on body mass index (BMI). Body fat content was measured by dual-energy X-ray absorptiometry (DEXA), and intravenous glucose tolerance test (IVGTT) was performed. The acute insulin response (AIR), the area under the curve (AUC) of insulin (AUCins) and homeostasis model assessment (HOMA) for β-cell function (HOMA2-% B) were calculated. Insulin resistance index(HOMA2-IR) and the ratio of AUCins to AUC of glucose (AUCins/AUCglu) were calculated to assess insulin resistance. Results Women with higher BMI appeared to have more total body fat content and trunk fat content. The similar distribution was also found in other parameters, including the plasma glucose levels at 0 and 10 min, AUCins, AIR, AUCins/AUCglu and the difference of insulin level between 0 and 10 min [INS (10-0)] during IVGTF. AUCins, AIR, AUCins/AUCglu and [INS (10-0)] were positively correlated with the age, BMI,total body fat content and trunk fat content. After adjustment of age, the trunk fat content was independently associated with the AIR in a good linear manner. Conclusion The obese females show change in body composition with more trunk fat content. They show significant insulin resistance with compensated elevation of insulin secretion. Body composition assessment is a valid and more accurate method than BMI and waist circumference in predicting early damaged β-cell function in obese patients.%目的 了解无糖尿病家族史、正常糖代谢肥胖女性体成分改变及胰岛β细胞功能变化.方法 双能X线骨密度仪(DXEA)检测75名入选对象体成分,并行静脉葡萄糖耐量试验(IVGTT),按体重指数(BMI)水平分为4组.以胰岛素曲线下面积(AUCins)、胰岛素急性时相分

  17. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine.

    Science.gov (United States)

    Leke, Renata; Bak, Lasse K; Anker, Malene; Melø, Torun M; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Portela, Luis V; Sonnewald, Ursula; Schousboe, Arne; Waagepetersen, Helle S

    2011-04-01

    Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme. Moreover, it has been suggested that cerebral tricarboxylic acid (TCA) cycle metabolism is inhibited and glycolysis enhanced during hyperammonemia. The aim of this study was to characterize the ammonia-detoxifying mechanisms as well as the effects of ammonia on energy-generating metabolic pathways in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important for ammonia detoxification as a supplement to formation of glutamine.

  18. Cellular uptake of PET tracers of glucose metabolism and hypoxia and their linkage

    Energy Technology Data Exchange (ETDEWEB)

    Busk, Morten; Horsman, Michael R.; Overgaard, Jens [Aarhus University Hospital, Department of Experimental Clinical Oncology, Aarhus C (Denmark); Jakobsen, Steen [Aarhus University Hospital, PET Centre, Aarhus (Denmark); Bussink, Johan; Kogel, Albert van der [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands)

    2008-12-15

    Tumour hypoxia and elevated glycolysis (Warburg effect) predict poor prognosis. Each parameter is assessable separately with positron emission tomography, but they are linked through anaerobic glycolysis (Pasteur effect). Here, we compare the oxygenation-dependent retention of fluoroazomycin arabinoside ([{sup 18}F]FAZA), a promising but not well-characterised hypoxia-specific tracer, and fluorodeoxyglucose ([{sup 18}F]FDG) in four carcinoma cell lines. Cells seeded on coverslips were positioned in modified Petri dishes that allow physically separated cells to share the same tracer-containing medium pool. Following oxic, hypoxic or anoxic tracer incubation, coverslips were analysed for radioactivity ([{sup 18}F]FDG+[{sup 18}F]FAZA) or re-incubated in tracer-free oxygenated medium and then measured ([{sup 18}F]FAZA). Next, we tested the reliability of [{sup 18}F]FDG as a relative measure of glucose metabolic rate. Finally, from two cell lines, xenografts were established in mice, and the tracer distribution between hypoxic and well-oxygenated areas were deduced from tissue sections. Three hours of anoxia strongly stimulated [{sup 18}F]FAZA retention with anoxic-to-oxic uptake ratios typically above 30. Three out of four cell lines displayed similar selectivity of [{sup 18}F]FDG versus glucose, but oxic uptake and anoxic-to-oxic uptake ratio of [{sup 18}F]FDG varied considerably. Although less pronounced, [{sup 18}F]FAZA also showed superior in vivo hypoxia specificity compared with [{sup 18}F]FDG. [{sup 18}F]FAZA displays excellent in vitro characteristics for hypoxia imaging including modest cell-to-cell line variability and no binding in oxic cells. In contrast, the usability of [{sup 18}F]FDG as a surrogate marker for hypoxia is questionable due to large variations in baseline (oxic) glucose metabolism and magnitudes of the Pasteur effects. (orig.)

  19. Glycogen and Glucose Metabolism Are Essential for Early Embryonic Development of the Red Flour Beetle Tribolium castaneum

    Science.gov (United States)

    Fraga, Amanda; Ribeiro, Lupis; Lobato, Mariana; Santos, Vitória; Silva, José Roberto; Gomes, Helga; da Cunha Moraes, Jorge Luiz; de Souza Menezes, Jackson

    2013-01-01

    Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3) and hexokinase (HexA) genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen. PMID:23750237

  20. Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

    Science.gov (United States)

    Fraga, Amanda; Ribeiro, Lupis; Lobato, Mariana; Santos, Vitória; Silva, José Roberto; Gomes, Helga; da Cunha Moraes, Jorge Luiz; de Souza Menezes, Jackson; de Oliveira, Carlos Jorge Logullo; Campos, Eldo; da Fonseca, Rodrigo Nunes

    2013-01-01

    Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3) and hexokinase (HexA) genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

  1. The Coupling of Cerebral Metabolic Rate of Glucose and Cerebral Blood Flow In Vivo

    DEFF Research Database (Denmark)

    Hasselbalch, Steen; Paulson, Olaf Bjarne

    2012-01-01

    The energy supplied to the brain by metabolic substrate is largely utilized for maintaining synaptic transmission. In this regulation cerebral blood flow and glucose consumption is tightly coupled as well in the resting condition as during activation. Quantification of cerebral blood flow...... not used for aerobic metabolism. Although some of the excess glucose uptake can be explained by lactate production, this phenomenon can still not account for the excess glucose uptake. Thus, more complex metabolic patterns in the brain might be reflected in the excess glucose uptake during activation...

  2. Symptoms of depression in people with impaired glucose metabolism or Type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Adriaanse, M C; Dekker, J M; Heine, R. J.

    2008-01-01

    OBJECTIVE: To study the prevalence and risk factors of depressive symptoms, comparing subjects with normal glucose metabolism (NGM), impaired glucose metabolism (IGM) or Type 2 diabetes mellitus (DM2). RESEARCH DESIGN AND METHODS: Cross-sectional data from a population-based cohort study conducted...... among 550 residents (276 men and 274 women) of the Hoorn region, the Netherlands. Levels of depressive symptoms were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D score > or = 16). Glucose metabolism status was determined by means of fasting and post-load glucose levels...

  3. Imaging glucose metabolism in perfluorocarbon-perfused hepatocyte bioreactors using positron emission tomography.

    Science.gov (United States)

    Nieuwoudt, Martin; Wiggett, Scholtz; Malfeld, Susan; van der Merwe, Schalk W

    2009-01-01

    In vitro hepatocyte bioreactor functionality depends particularly on maintaining appropriate oxygen levels and exposure to nonparenchymal cells. An attractive solution without immunological consequences to the patient is incorporating a perfluorocarbon oxygen carrier in the circulating medium and co-culturing hepatocytes with stellate cells. Since bioreactors are normally sealed sterile units, demonstrating metabolic functionality is hindered by limited access to the cells after their aggregation in the matrix. A novel possibility is to use positron emission tomography (PET) to image cellular radioactive glucose uptake under O(2)-limited conditions. In this study, primary cell isolation procedures were carried out on eight pigs. Pairs of cell-seeded and cell-free (control) bioreactors with and without perfluorocarbon were cultured under identical conditions and were oxygenated using hypoxic (5% O(2)) and ambient (20% O(2)) gas mixes. Sixteen PET scans were conducted 24 h after cell isolation, the same timescale as that involved in treating a liver failure patient with a primary-cell bioreactor. In all cases, cell-seeded bioreactors without perfluorocarbon were more radioactive, i.e., were more glycolytic, than those with perfluorocarbon. This difference was significant in the hypoxic pair of bioreactors but not in the ambient pair of bioreactors. Additionally, in the same hypoxic bioreactors, circulating extracellular steady-state glucose levels were significantly lower and lactate levels were higher than those in the ambient bioreactors. Similar findings have been made in other in vitro hepatocyte studies investigating the effects of perfluorocarbons. PET is attractive for studying in situ O(2)-dependent bioreactor metabolism because of its visual and numerically quantifiable outputs. Longer-term metabolic studies (e.g., 5-10 days) investigating the effect of perfluorocarbon on bioreactor longevity will complement these findings in the future.

  4. Impaired glucose metabolism in HIV-infected pregnant women: a retrospective analysis.

    LENUS (Irish Health Repository)

    Moore, Rebecca

    2015-05-20

    Metabolic complications including diabetes mellitus have been increasingly recognised in HIV-infected individuals since the introduction of antiretroviral therapy, particularly protease inhibitors (PIs). Pregnancy is also a risk factor for impaired glucose metabolism, and previous studies have given conflicting results regarding the contribution of PIs to impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) in pregnant HIV-infected women.

  5. Effect of oxandrolone on glucose metabolism in growth hormone-treated girls with Turner syndrome

    NARCIS (Netherlands)

    Menke, L.A.; Sas, T.C.J.; Stijnen, T.; Zandwijken, G.R.; Muinck Keizer-Schrama, S.M.P.F. de; Otten, B.J.; Wit, J.M.

    2011-01-01

    BACKGROUND: The weak androgen oxandrolone (Ox) may increase height but may also affect glucose metabolism in girls with Turner syndrome (TS). METHODS: In a randomized, placebo-controlled, double-blind study, we assessed the effect of Ox at a dosage of either 0.06 or 0.03 mg/kg/day on glucose metabol

  6. Implications of Hydrogen Sulfide in Glucose Regulation: How H2S Can Alter Glucose Homeostasis through Metabolic Hormones.

    Science.gov (United States)

    Pichette, Jennifer; Gagnon, Jeffrey

    2016-01-01

    Diabetes and its comorbidities continue to be a major health problem worldwide. Understanding the precise mechanisms that control glucose homeostasis and their dysregulation during diabetes are a major research focus. Hydrogen sulfide (H2S) has emerged as an important regulator of glucose homeostasis. This is achieved through its production and action in several metabolic and hormone producing organs including the pancreas, liver, and adipose. Of importance, H2S production and signaling in these tissues are altered during both type 1 and type 2 diabetes mellitus. This review first examines how H2S is produced both endogenously and by gastrointestinal microbes, with a particular focus on the altered production that occurs during obesity and diabetes. Next, the action of H2S on the metabolic organs with key roles in glucose homeostasis, with a particular focus on insulin, is described. Recent work has also suggested that the effects of H2S on glucose homeostasis goes beyond its role in insulin secretion. Several studies have demonstrated important roles for H2S in hepatic glucose output and adipose glucose uptake. The mechanism of H2S action on these metabolic organs is described. In the final part of this review, future directions examining the roles of H2S in other metabolic and glucoregulatory hormone secreting tissues are proposed.

  7. Adenovirus-mediated transfection with glucose transporter 3 suppresses PC12 cell apoptosis following ischemic injury

    Institute of Scientific and Technical Information of China (English)

    Junliang Li; Xinke Xu; Shanyi Zhang; Meiguang Zheng; Zhonghua Wu; Yinlun Weng; Leping Ouyang; Jian Yu; Fangcheng Li

    2012-01-01

    In this study, we investigated the effects of adenovirus-mediated transfection of PC12 cells with glucose transporter 3 after ischemic injury. The results of flow cytometry and TUNEL showed that exogenous glucose transporter 3 significantly suppressed PC12 cell apoptosis induced by ischemic injury. The results of isotopic scintiscan and western blot assays showed that, the glucose uptake rate was significantly increased and nuclear factor kappaB expression was significantly decreased after adenovirus-mediated transfection of ischemic PC12 cells with glucose transporter 3. These results suggest that adenovirus-mediated transfection of cells with glucose transporter 3 elevates the energy metabolism of PC12 cells with ischemic injury, and inhibits cell apoptosis.

  8. Role of glucose and ketone bodies in the metabolic control of experimental brain cancer.

    Science.gov (United States)

    Seyfried, T N; Sanderson, T M; El-Abbadi, M M; McGowan, R; Mukherjee, P

    2003-10-06

    Brain tumours lack metabolic versatility and are dependent largely on glucose for energy. This contrasts with normal brain tissue that can derive energy from both glucose and ketone bodies. We examined for the first time the potential efficacy of dietary therapies that reduce plasma glucose and elevate ketone bodies in the CT-2A syngeneic malignant mouse astrocytoma. C57BL/6J mice were fed either a standard diet unrestricted (SD-UR), a ketogenic diet unrestricted (KD-UR), the SD restricted to 40% (SD-R), or the KD restricted to 40% of the control standard diet (KD-R). Body weights, tumour weights, plasma glucose, beta-hydroxybutyrate (beta-OHB), and insulin-like growth factor 1 (IGF-1) were measured 13 days after tumour implantation. CT-2A growth was rapid in both the SD-UR and KD-UR groups, but was significantly reduced in both the SD-R and KD-R groups by about 80%. The results indicate that plasma glucose predicts CT-2A growth and that growth is dependent more on the amount than on the origin of dietary calories. Also, restriction of either diet significantly reduced the plasma levels of IGF-1, a biomarker for angiogenesis and tumour progression. Owing to a dependence on plasma glucose, IGF-1 was also predictive of CT-2A growth. Ketone bodies are proposed to reduce stromal inflammatory activities, while providing normal brain cells with a nonglycolytic high-energy substrate. Our results in a mouse astrocytoma suggest that malignant brain tumours are potentially manageable with dietary therapies that reduce glucose and elevate ketone bodies.

  9. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine

    DEFF Research Database (Denmark)

    Leke, Renata; Bak, Lasse Kristoffer; Anker, Malene

    2011-01-01

    in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure...... enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important......Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme...

  10. A CREB-Sirt1-Hes1 Circuitry Mediates Neural Stem Cell Response to Glucose Availability

    Directory of Open Access Journals (Sweden)

    Salvatore Fusco

    2016-02-01

    Full Text Available Adult neurogenesis plays increasingly recognized roles in brain homeostasis and repair and is profoundly affected by energy balance and nutrients. We found that the expression of Hes-1 (hairy and enhancer of split 1 is modulated in neural stem and progenitor cells (NSCs by extracellular glucose through the coordinated action of CREB (cyclic AMP responsive element binding protein and Sirt-1 (Sirtuin 1, two cellular nutrient sensors. Excess glucose reduced CREB-activated Hes-1 expression and results in impaired cell proliferation. CREB-deficient NSCs expanded poorly in vitro and did not respond to glucose availability. Elevated glucose also promoted Sirt-1-dependent repression of the Hes-1 promoter. Conversely, in low glucose, CREB replaced Sirt-1 on the chromatin associated with the Hes-1 promoter enhancing Hes-1 expression and cell proliferation. Thus, the glucose-regulated antagonism between CREB and Sirt-1 for Hes-1 transcription participates in the metabolic regulation of neurogenesis.

  11. Association between DNA Methylation in Whole Blood and Measures of Glucose Metabolism: KORA F4 Study.

    Directory of Open Access Journals (Sweden)

    Jennifer Kriebel

    Full Text Available Epigenetic regulation has been postulated to affect glucose metabolism, insulin sensitivity and the risk of type 2 diabetes. Therefore, we performed an epigenome-wide association study for measures of glucose metabolism in whole blood samples of the population-based Cooperative Health Research in the Region of Augsburg F4 study using the Illumina HumanMethylation 450 BeadChip. We identified a total of 31 CpG sites where methylation level was associated with measures of glucose metabolism after adjustment for age, sex, smoking, and estimated white blood cell proportions and correction for multiple testing using the Benjamini-Hochberg (B-H method (four for fasting glucose, seven for fasting insulin, 25 for homeostasis model assessment-insulin resistance [HOMA-IR]; B-H-adjusted p-values between 9.2x10(-5 and 0.047. In addition, DNA methylation at cg06500161 (annotated to ABCG1 was associated with all the aforementioned phenotypes and 2-hour glucose (B-H-adjusted p-values between 9.2x10(-5 and 3.0x10(-3. Methylation status of additional three CpG sites showed an association with fasting insulin only after additional adjustment for body mass index (BMI (B-H-adjusted p-values = 0.047. Overall, effect strengths were reduced by around 30% after additional adjustment for BMI, suggesting that this variable has an influence on the investigated phenotypes. Furthermore, we found significant associations between methylation status of 21 of the aforementioned CpG sites and 2-hour insulin in a subset of samples with seven significant associations persisting after additional adjustment for BMI. In a subset of 533 participants, methylation of the CpG site cg06500161 (ABCG1 was inversely associated with ABCG1 gene expression (B-H-adjusted p-value = 1.5x10(-9. Additionally, we observed an enrichment of the top 1,000 CpG sites for diabetes-related canonical pathways using Ingenuity Pathway Analysis. In conclusion, our study indicates that DNA methylation and

  12. Association between DNA Methylation in Whole Blood and Measures of Glucose Metabolism: KORA F4 Study.

    Science.gov (United States)

    Kriebel, Jennifer; Herder, Christian; Rathmann, Wolfgang; Wahl, Simone; Kunze, Sonja; Molnos, Sophie; Volkova, Nadezda; Schramm, Katharina; Carstensen-Kirberg, Maren; Waldenberger, Melanie; Gieger, Christian; Peters, Annette; Illig, Thomas; Prokisch, Holger; Roden, Michael; Grallert, Harald

    2016-01-01

    Epigenetic regulation has been postulated to affect glucose metabolism, insulin sensitivity and the risk of type 2 diabetes. Therefore, we performed an epigenome-wide association study for measures of glucose metabolism in whole blood samples of the population-based Cooperative Health Research in the Region of Augsburg F4 study using the Illumina HumanMethylation 450 BeadChip. We identified a total of 31 CpG sites where methylation level was associated with measures of glucose metabolism after adjustment for age, sex, smoking, and estimated white blood cell proportions and correction for multiple testing using the Benjamini-Hochberg (B-H) method (four for fasting glucose, seven for fasting insulin, 25 for homeostasis model assessment-insulin resistance [HOMA-IR]; B-H-adjusted p-values between 9.2x10(-5) and 0.047). In addition, DNA methylation at cg06500161 (annotated to ABCG1) was associated with all the aforementioned phenotypes and 2-hour glucose (B-H-adjusted p-values between 9.2x10(-5) and 3.0x10(-3)). Methylation status of additional three CpG sites showed an association with fasting insulin only after additional adjustment for body mass index (BMI) (B-H-adjusted p-values = 0.047). Overall, effect strengths were reduced by around 30% after additional adjustment for BMI, suggesting that this variable has an influence on the investigated phenotypes. Furthermore, we found significant associations between methylation status of 21 of the aforementioned CpG sites and 2-hour insulin in a subset of samples with seven significant associations persisting after additional adjustment for BMI. In a subset of 533 participants, methylation of the CpG site cg06500161 (ABCG1) was inversely associated with ABCG1 gene expression (B-H-adjusted p-value = 1.5x10(-9)). Additionally, we observed an enrichment of the top 1,000 CpG sites for diabetes-related canonical pathways using Ingenuity Pathway Analysis. In conclusion, our study indicates that DNA methylation and diabetes

  13. Metabolic regulation of lateral hypothalamic glucose-inhibited orexin neurons may influence midbrain reward neurocircuitry.

    Science.gov (United States)

    Sheng, Zhenyu; Santiago, Ammy M; Thomas, Mark P; Routh, Vanessa H

    2014-09-01

    Lateral hypothalamic area (LHA) orexin neurons modulate reward-based feeding by activating ventral tegmental area (VTA) dopamine (DA) neurons. We hypothesize that signals of peripheral energy status influence reward-based feeding by modulating the glucose sensitivity of LHA orexin glucose-inhibited (GI) neurons. This hypothesis was tested using electrophysiological recordings of LHA orexin-GI neurons in brain slices from 4 to 6week old male mice whose orexin neurons express green fluorescent protein (GFP) or putative VTA-DA neurons from C57Bl/6 mice. Low glucose directly activated ~60% of LHA orexin-GFP neurons in both whole cell and cell attached recordings. Leptin indirectly reduced and ghrelin directly enhanced the activation of LHA orexin-GI neurons by glucose decreases from 2.5 to 0.1mM by 53±12% (n=16, PFasting increased activation of LHA orexin-GI neurons by decreased glucose, as would be predicted by these hormonal effects. We also evaluated putative VTA-DA neurons in a novel horizontal slice preparation containing the LHA and VTA. Decreased glucose increased the frequency of spontaneous excitatory post-synaptic currents (sEPSCs; 125 ± 40%, n=9, P<0.05) and action potentials (n=9; P<0.05) in 45% (9/20) of VTA DA neurons. sEPSCs were completely blocked by AMPA and NMDA glutamate receptor antagonists (CNQX 20 μM, n=4; APV 20μM, n=4; respectively), demonstrating that these sEPSCs were mediated by glutamatergic transmission onto VTA DA neurons. Orexin-1 but not 2 receptor antagonism with SB334867 (10μM; n=9) and TCS-OX2-29 (2μM; n=5), respectively, blocks the effects of decreased glucose on VTA DA neurons. Thus, decreased glucose increases orexin-dependent excitatory glutamate neurotransmission onto VTA DA neurons. These data suggest that the glucose sensitivity of LHA orexin-GI neurons links metabolic state and reward-based feeding.

  14. Metabolic alterations in renal cell carcinoma.

    Science.gov (United States)

    Massari, Francesco; Ciccarese, Chiara; Santoni, Matteo; Brunelli, Matteo; Piva, Francesco; Modena, Alessandra; Bimbatti, Davide; Fantinel, Emanuela; Santini, Daniele; Cheng, Liang; Cascinu, Stefano; Montironi, Rodolfo; Tortora, Giampaolo

    2015-11-01

    Renal cell carcinoma (RCC) is a metabolic disease, being characterized by the dysregulation of metabolic pathways involved in oxygen sensing (VHL/HIF pathway alterations and the subsequent up-regulation of HIF-responsive genes such as VEGF, PDGF, EGF, and glucose transporters GLUT1 and GLUT4, which justify the RCC reliance on aerobic glycolysis), energy sensing (fumarate hydratase-deficient, succinate dehydrogenase-deficient RCC, mutations of HGF/MET pathway resulting in the metabolic Warburg shift marked by RCC increased dependence on aerobic glycolysis and the pentose phosphate shunt, augmented lipogenesis, and reduced AMPK and Krebs cycle activity) and/or nutrient sensing cascade (deregulation of AMPK-TSC1/2-mTOR and PI3K-Akt-mTOR pathways). We analyzed the key metabolic abnormalities underlying RCC carcinogenesis, highlighting those altered pathways that may represent potential targets for the development of more effective therapeutic strategies.

  15. Zonation of glucose and fatty acid metabolism in the liver : Mechanism and metabolic consequences

    NARCIS (Netherlands)

    Hijmans, Brenda S.; Greffiorst, Aldo; Oosterveer, Maaike H.; Groen, Albert K.

    2014-01-01

    The liver is generally considered as a relatively homogeneous organ containing four different cell types. It is however well-known that the liver is not homogeneous and consists of clearly demarcated metabolic zones. Hepatocytes from different zones show phenotypical heterogeneity in metabolic featu

  16. Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome

    DEFF Research Database (Denmark)

    Leder, Lena; Kolehmainen, Marjukka; Narverud, Ingunn;

    2016-01-01

    BACKGROUND: Diet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism...... protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L(-1), and baseline body mass index ..., and the mRNA gene expression analysis was measured by quantitative real-time polymerase chain reaction (qPCR). We analyzed the mRNA expression changes of 44 genes before and after a 2hOGTT at the beginning and the end of the intervention. RESULTS: The healthy ND significantly down-regulated the expression...

  17. Sex-Dependent Programming of Glucose and Fatty Acid Metabolism in Mouse Offspring by Maternal Protein Restriction

    NARCIS (Netherlands)

    van Straten, Esther M. E.; Bloks, Vincent W.; van Dijk, Theo H.; Baller, Julius F. W.; Huijkman, Nicolette C. A.; Kuipers, Irma; Verkade, Henkjan J.; Plosch, Torsten

    2012-01-01

    Background: Nutritional conditions during fetal life influence the risk of the development of metabolic syndrome and cardiovascular diseases in adult life (metabolic programming). Impaired glucose tolerance and dysregulated fatty acid metabolism are hallmarks of metabolic syndrome. Objective: We aim

  18. Metabolic engineering of Corynebacterium glutamicum to produce GDP-L-fucose from glucose and mannose.

    Science.gov (United States)

    Chin, Young-Wook; Park, Jin-Byung; Park, Yong-Cheol; Kim, Kyoung Heon; Seo, Jin-Ho

    2013-06-01

    Wild-type Corynebacterium glutamicum was metabolically engineered to convert glucose and mannose into guanosine 5'-diphosphate (GDP)-L-fucose, a precursor of fucosyl-oligosaccharides, which are involved in various biological and pathological functions. This was done by introducing the gmd and wcaG genes of Escherichia coli encoding GDP-D-mannose-4,6-dehydratase and GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase-4-reductase, respectively, which are known as key enzymes in the production of GDP-L-fucose from GDP-D-mannose. Coexpression of the genes allowed the recombinant C. glutamicum cells to produce GDP-L-fucose in a minimal medium containing glucose and mannose as carbon sources. The specific product formation rate was much higher during growth on mannose than on glucose. In addition, the specific product formation rate was further increased by coexpressing the endogenous phosphomanno-mutase gene (manB) and GTP-mannose-1-phosphate guanylyl-transferase gene (manC), which are involved in the conversion of mannose-6-phosphate into GDP-D-mannose. However, the overexpression of manA encoding mannose-6-phosphate isomerase, catalyzing interconversion of mannose-6-phosphate and fructose-6-phosphate showed a negative effect on formation of the target product. Overall, coexpression of gmd, wcaG, manB and manC in C. glutamicum enabled production of GDP-L-fucose at the specific rate of 0.11 mg g cell(-1) h(-1). The specific GDP-L-fucose content reached 5.5 mg g cell(-1), which is a 2.4-fold higher than that of the recombinant E. coli overexpressing gmd, wcaG, manB and manC under comparable conditions. Well-established metabolic engineering tools may permit optimization of the carbon and cofactor metabolisms of C. glutamicum to further improve their production capacity.

  19. Zonation of nitrogen and glucose metabolism gene expression upon acute liver damage in mouse.

    Directory of Open Access Journals (Sweden)

    Shahrouz Ghafoory

    Full Text Available Zonation of metabolic activities within specific structures and cell types is a phenomenon of liver organization and ensures complementarity of variant liver functions like protein production, glucose homeostasis and detoxification. To analyze damage and regeneration of liver tissue in response to a toxic agent, expression of liver specific enzymes was analyzed by in situ hybridization in mouse over a 6 days time course following carbon tetrachloride (CCl4 injection. CCl4 mixed with mineral oil was administered to BALB/c mice by intraperitoneal injection, and mice were sacrificed at different time points post injection. Changes in the expression of albumin (Alb, arginase (Arg1, glutaminase 2 (Gls2, Glutamine synthetase (Gs, glucose-6-phosphatase (G6pc, glycogen synthase 2 (Gys2, Glycerinaldehyd-3-phosphat-Dehydrogenase (Gapdh, Cytochrom p450 2E1 (Cyp2e1 and glucagon receptor (Gcgr genes in the liver were studied by in situ hybridization and qPCR. We observed significant changes in gene expression of enzymes involved in nitrogen and glucose metabolism and their local distribution following CCl4 injury. We also found that Cyp2e1, the primary metabolizing enzyme for CCl4, was strongly expressed in the pericentral zone during recovery. Furthermore, cells in the damaged area displayed distinct gene expression profiles during the analyzed time course and showed complete recovery with strong albumin production 6 days after CCl4 injection. Our results indicate that despite severe damage, liver cells in the damaged area do not simply die but instead display locally adjusted gene expression supporting damage response and recovery.

  20. Zonation of Nitrogen and Glucose Metabolism Gene Expression upon Acute Liver Damage in Mouse

    Science.gov (United States)

    Ghafoory, Shahrouz; Breitkopf-Heinlein, Katja; Li, Qi; Scholl, Catharina; Dooley, Steven; Wölfl, Stefan

    2013-01-01

    Zonation of metabolic activities within specific structures and cell types is a phenomenon of liver organization and ensures complementarity of variant liver functions like protein production, glucose homeostasis and detoxification. To analyze damage and regeneration of liver tissue in response to a toxic agent, expression of liver specific enzymes was analyzed by in situ hybridization in mouse over a 6 days time course following carbon tetrachloride (CCl4) injection. CCl4 mixed with mineral oil was administered to BALB/c mice by intraperitoneal injection, and mice were sacrificed at different time points post injection. Changes in the expression of albumin (Alb), arginase (Arg1), glutaminase 2 (Gls2), Glutamine synthetase (Gs), glucose-6-phosphatase (G6pc), glycogen synthase 2 (Gys2), Glycerinaldehyd-3-phosphat-Dehydrogenase (Gapdh), Cytochrom p450 2E1 (Cyp2e1) and glucagon receptor (Gcgr) genes in the liver were studied by in situ hybridization and qPCR. We observed significant changes in gene expression of enzymes involved in nitrogen and glucose metabolism and their local distribution following CCl4 injury. We also found that Cyp2e1, the primary metabolizing enzyme for CCl4, was strongly expressed in the pericentral zone during recovery. Furthermore, cells in the damaged area displayed distinct gene expression profiles during the analyzed time course and showed complete recovery with strong albumin production 6 days after CCl4 injection. Our results indicate that despite severe damage, liver cells in the damaged area do not simply die but instead display locally adjusted gene expression supporting damage response and recovery. PMID:24147127

  1. Nanomolar Caffeic Acid Decreases Glucose Uptake and the Effects of High Glucose in Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Lucia Natarelli

    Full Text Available Epidemiological studies suggest that moderate and prolonged consumption of coffee is associated with a reduced risk of developing type 2 diabetes but the molecular mechanisms underlying this effect are not known. In this study, we report the effects of physiological concentrations of caffeic acid, easily achievable by normal dietary habits, in endothelial cells cultured in 25 mM of glucose (high glucose, HG. In HG, the presence of 10 nM caffeic acid was associated with a decrease of glucose uptake but not to changes of GLUT-1 membrane localization or mRNA levels. Moreover, caffeic acid countered HG-induced loss of barrier integrity, reducing actin rearrangement and FITC-dextran passage. The decreased flux of glucose associated to caffeic acid affected HG induced apoptosis by down-regulating the expression of initiator (caspase 8 and 9 and effector caspases (caspase 7 and 3 and by increasing the levels of phosphorylated Bcl-2. We also observed that caffeic acid in HG condition was associated to a reduction of p65 subunit nuclear levels with respect to HG alone. NF-κB activation has been shown to lead to apoptosis in HG treated cells and the analysis of the expression of a panel of about 90 genes related to NF-κB signaling pathway revealed that caffeic acid significantly influenced gene expression changes induced by HG. In conclusion, our results suggest that caffeic acid, decreasing the metabolic stress induced by HG, allows the activation of survival mechanisms mediated by a different modulation of NF-κB-related signaling pathways and to the activation of anti-apoptotic proteins.

  2. Anorexia and Impaired Glucose Metabolism in Mice With Hypothalamic Ablation of Glut4 Neurons

    Science.gov (United States)

    Ren, Hongxia; Lu, Taylor Y.; McGraw, Timothy E.

    2015-01-01

    The central nervous system (CNS) uses glucose independent of insulin. Nonetheless, insulin receptors and insulin-responsive glucose transporters (Glut4) often colocalize in neurons (Glut4 neurons) in anatomically and functionally distinct areas of the CNS. The apparent heterogeneity of Glut4 neurons has thus far thwarted attempts to understand their function. To answer this question, we used Cre-dependent, diphtheria toxin–mediated cell ablation to selectively remove basal hypothalamic Glut4 neurons and investigate the resulting phenotypes. After Glut4 neuron ablation, mice demonstrate altered hormone and nutrient signaling in the CNS. Accordingly, they exhibit negative energy balance phenotype characterized by reduced food intake and increased energy expenditure, without locomotor deficits or gross neuronal abnormalities. Glut4 neuron ablation affects orexigenic melanin-concentrating hormone neurons but has limited effect on neuropeptide Y/agouti-related protein and proopiomelanocortin neurons. The food intake phenotype can be partially normalized by GABA administration, suggesting that it arises from defective GABAergic transmission. Glut4 neuron–ablated mice show peripheral metabolic defects, including fasting hyperglycemia and glucose intolerance, decreased insulin levels, and elevated hepatic gluconeogenic genes. We conclude that Glut4 neurons integrate hormonal and nutritional cues and mediate CNS actions of insulin on energy balance and peripheral metabolism. PMID:25187366

  3. Anorexia and impaired glucose metabolism in mice with hypothalamic ablation of Glut4 neurons.

    Science.gov (United States)

    Ren, Hongxia; Lu, Taylor Y; McGraw, Timothy E; Accili, Domenico

    2015-02-01

    The central nervous system (CNS) uses glucose independent of insulin. Nonetheless, insulin receptors and insulin-responsive glucose transporters (Glut4) often colocalize in neurons (Glut4 neurons) in anatomically and functionally distinct areas of the CNS. The apparent heterogeneity of Glut4 neurons has thus far thwarted attempts to understand their function. To answer this question, we used Cre-dependent, diphtheria toxin-mediated cell ablation to selectively remove basal hypothalamic Glut4 neurons and investigate the resulting phenotypes. After Glut4 neuron ablation, mice demonstrate altered hormone and nutrient signaling in the CNS. Accordingly, they exhibit negative energy balance phenotype characterized by reduced food intake and increased energy expenditure, without locomotor deficits or gross neuronal abnormalities. Glut4 neuron ablation affects orexigenic melanin-concentrating hormone neurons but has limited effect on neuropeptide Y/agouti-related protein and proopiomelanocortin neurons. The food intake phenotype can be partially normalized by GABA administration, suggesting that it arises from defective GABAergic transmission. Glut4 neuron-ablated mice show peripheral metabolic defects, including fasting hyperglycemia and glucose intolerance, decreased insulin levels, and elevated hepatic gluconeogenic genes. We conclude that Glut4 neurons integrate hormonal and nutritional cues and mediate CNS actions of insulin on energy balance and peripheral metabolism.

  4. Effects of sodium benzoate, a widely used food preservative, on glucose homeostasis and metabolic profiles in humans.

    Science.gov (United States)

    Lennerz, Belinda S; Vafai, Scott B; Delaney, Nigel F; Clish, Clary B; Deik, Amy A; Pierce, Kerry A; Ludwig, David S; Mootha, Vamsi K

    2015-01-01

    Sodium benzoate is a widely used preservative found in many foods and soft drinks. It is metabolized within mitochondria to produce hippurate, which is then cleared by the kidneys. We previously reported that ingestion of sodium benzoate at the generally regarded as safe (GRAS) dose leads to a robust excursion in the plasma hippurate level [1]. Since previous reports demonstrated adverse effects of benzoate and hippurate on glucose homeostasis in cells and in animal models, we hypothesized that benzoate might represent a widespread and underappreciated diabetogenic dietary exposure in humans. Here, we evaluated whether acute exposure to GRAS levels of sodium benzoate alters insulin and glucose homeostasis through a randomized, controlled, cross-over study of 14 overweight subjects. Serial blood samples were collected following an oral glucose challenge, in the presence or absence of sodium benzoate. Outcome measurements included glucose, insulin, glucagon, as well as temporal mass spectrometry-based metabolic profiles. We did not find a statistically significant effect of an acute oral exposure to sodium benzoate on glucose homeostasis. Of the 146 metabolites targeted, four changed significantly in response to benzoate, including the expected rise in benzoate and hippurate. In addition, anthranilic acid, a tryptophan metabolite, exhibited a robust rise, while acetylglycine dropped. Although our study shows that GRAS doses of benzoate do not have an acute, adverse effect on glucose homeostasis, future studies will be necessary to explore the metabolic impact of chronic benzoate exposure.

  5. Dehydroepiandrosterone Inhibits Glucose Flux Through the Pentose Phosphate Pathway in Human and Mouse Endometrial Stromal Cells, Preventing Decidualization and Implantation

    OpenAIRE

    Frolova, Antonina I.; O'Neill, Kathleen; Moley, Kelle H.

    2011-01-01

    Endometrial stromal cells (ESC) must undergo a hormone-driven differentiation to form decidual cells as a requirement of proper embryo implantation. Recent studies from our laboratory have demonstrated that decidualizing cells require glucose transporter 1 expression and an increase in glucose use to complete this step. The present study focuses on the glucose-dependent molecular and metabolic pathways, which are required by ESC for decidualization. Inhibition of glycolysis had no effect on d...

  6. Emerging roles of the myocardin family of proteins in lipid and glucose metabolism.

    Science.gov (United States)

    Swärd, Karl; Stenkula, Karin G; Rippe, Catarina; Alajbegovic, Azra; Gomez, Maria F; Albinsson, Sebastian

    2016-09-01

    Members of the myocardin family bind to the transcription factor serum response factor (SRF) and act as coactivators controlling genes of relevance for myogenic differentiation and motile function. Binding of SRF to DNA is mediated by genetic elements called CArG boxes, found often but not exclusively in muscle and growth controlling genes. Studies aimed at defining the full spectrum of these CArG elements in the genome (i.e. the CArGome) have in recent years, unveiled unexpected roles of the myocardin family proteins in lipid and glucose homeostasis. This coactivator family includes the protein myocardin (MYOCD), the myocardin-related transcription factors A and B (MRTF-A/MKL1 and MRTF-B/MKL2) and MASTR (MAMSTR). Here we discuss growing evidence that SRF-driven transcription is controlled by extracellular glucose through activation of the Rho-kinase pathway and actin polymerization. We also describe data showing that adipogenesis is influenced by MLK activity through actions upstream of peroxisome proliferator-activated receptor γ with consequences for whole body fat mass and insulin sensitivity. The recently demonstrated involvement of myocardin coactivators in the biogenesis of caveolae, Ω-shaped membrane invaginations of importance for lipid and glucose metabolism, is finally discussed. These novel roles of myocardin proteins may open the way for new unexplored strategies to combat metabolic diseases such as diabetes, which, at the current incidence, is expected to reach 333 million people worldwide by 2025. This review highlights newly discovered roles of myocardin-related transcription factors in lipid and glucose metabolism as well as novel insights into their well-established role as mediators of stretch-dependent effects in smooth muscle. As co-factors for serum response factor (SRF), MKLs regulates transcription of genes involved in the contractile function of smooth muscle cells. In addition to mechanical stimuli, this regulation has now been found to

  7. Developmental role for endocannabinoid signaling in regulating glucose metabolism and growth.

    Science.gov (United States)

    Li, Zhiying; Schmidt, Sarah F; Friedman, Jeffrey M

    2013-07-01

    Treatment of ob/ob (obese) mice with a cannabinoid receptor 1 (Cnr1) antagonist reduces food intake, suggesting a role for endocannabinoid signaling in leptin action. We further evaluated the role of endocannabinoid signaling by analyzing the phenotype of Cnr1 knockout ob/ob mice. Double mutant animals show a more severe growth retardation than ob/ob mice with similar levels of adiposity and reduced IGF-I levels without alterations of growth hormone (GH) levels. The double mutant mice are also significantly more glucose intolerant than ob/ob mice. This is in contrast to treatment of ob/ob mice with a Cnr1 antagonist that had no effect on glucose metabolism, suggesting a possible requirement for endocannabinoid signaling during development for normal glucose homeostasis. Double mutant animals also showed similar leptin sensitivity as ob/ob mice, suggesting that there are developmental changes that compensate for the loss of Cnr1 signaling. These data establish a role for Cnr1 during development and suggest that compensatory changes during development may mitigate the requirement for Cnr1 in mediating the effects of leptin. The data also suggest a developmental role for Cnr1 to promote growth, regulate the GH/IGF-I axis, and improve β-cell function and glucose homeostasis in the setting of leptin deficiency.

  8. Brain pyruvate recycling and peripheral metabolism: an NMR analysis ex vivo of acetate and glucose metabolism in the rat.

    Science.gov (United States)

    Serres, Sébastien; Bezancon, Eric; Franconi, Jean-Michel; Merle, Michel

    2007-06-01

    The occurrence of pyruvate recycling in the rat brain was studied in either pentobarbital anesthetized animals or awake animals receiving a light analgesic dose of morphine, which were infused with either [1-13C]glucose + acetate or glucose + [2-13C]acetate for various periods of time. Metabolite enrichments in the brain, blood and the liver were determined from NMR analyses of tissue extracts. They indicated that: (i) Pyruvate recycling was revealed in the brain of both the anesthetized and awake animals, as well as from lactate and alanine enrichments as from glutamate isotopomer composition, but only after infusion of glucose + [2-13C]acetate. (ii) Brain glucose was labelled from [2-13C]acetate at the same level in anaesthetized and awake rats (approximately 4%). Comparing its enrichment with that of blood and liver glucose indicated that brain glucose labelling resulted from hepatic gluconeogenesis. (iii) Analysing glucose 13C-13C coupling in the brain, blood and the liver confirmed that brain glucose could be labelled in the liver through the activities of both pyruvate recycling and gluconeogenesis. (iv) The rate of appearance and the amount of brain glutamate C4-C5 coupling, a marker of pyruvate recycling when starting from [2-13C]acetate, were lower than those of brain glucose labelling from hepatic metabolism. (v) The evaluation of the contributions of glucose and acetate to glutamate metabolism revealed that more than 60% of brain glutamate was synthesized from glucose whereas only 7% was from acetate and that glutamate C4-C5 coupling was mainly due to the metabolism of glucose labelled through hepatic gluconeogenesis. All these results indicate that, under the present conditions, the pyruvate recycling observed through the labelling of brain metabolites mainly originates from peripheral metabolism.

  9. Inhibition of murine splenic T lymphocyte proliferation by 2-deoxy-D-glucose-induced metabolic stress

    Science.gov (United States)

    Miller, E. S.; Klinger, J. C.; Akin, C.; Koebel, D. A.; Sonnenfeld, G.

    1994-01-01

    Female Swiss-Webster mice were injected with the glucose analogue 2-deoxy-D-glucose (2-DG), which when administered to rodents induces acute periods of metabolic stress. A single or multiple injections of 2-DG invoked a stress response, as evidenced by increases in serum corticosterone levels. The influence of this metabolic stressor on the blastogenic potential of splenic T lymphocytes was then examined. It was found that one, two, or three injections of 2-DG resulted in depressed T cell proliferative responses, with an attenuation of the effect occurring by the fifth injection. The 2-DG-induced inhibition of T cell proliferation was not attributable to 2-DG-induced cytolysis, as in vitro incubation of naive T cells with varying concentrations of 2-DG did not result in a reduction in cell number or viability, and flow cytometric analysis demonstrated that percentages of CD3, CD4, and CD8 splenic T cells were not altered as a result of 2-DG-induced stress. Incubating naive T cells in varying concentrations of 2-DG resulted in a dose-dependent inhibition of T cell blastogenic potential. Following in vivo exposure to 2-DG, T cell proliferation did not return to normal levels until 3 days after the cessation of 2-DG injections. Administering the beta-adrenergic receptor antagonist propranolol did not reverse the inhibited lymphoproliferation in 2-DG-treated mice. The inhibition in T cell proliferation was not observed, however, in mice that had been adrenalectomized or hypophysectomized and injected with 2-DG.(ABSTRACT TRUNCATED AT 250 WORDS).

  10. Gluconeogenesis and amino acids metabolism in ovarian clear cell carcinoma

    OpenAIRE

    2013-01-01

    Dissertação de mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2013 Tumor cells may exhibit different metabolic profiles compared to normal tissues from which they are derived. Those observations gave rise to the new concept that tumorigenesis requires metabolic alterations to sustain cell proliferation. Several studies reveal that increased cell proliferation is accompanied by increased glucose consumption. In OCCC, a typical morphol...

  11. Thalamic, brainstem, and cerebellar glucose metabolism in the hemiplegic monkey

    Energy Technology Data Exchange (ETDEWEB)

    Shimoyama, I.; Dauth, G.W.; Gilman, S.; Frey, K.A.; Penney, J.B. Jr.

    1988-12-01

    Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a contralateral hemiplegia that resolves partially with time. During the phase of dense hemiplegia, local cerebral metabolic rate for glucose (1CMRG1c) is decreased significantly in most of the thalamic nuclei ipsilateral to the ablation, and there are slight contralateral decreases. The lCMRGlc is reduced bilaterally in most of the brainstem nuclei and bilaterally in the deep cerebellar nuclei, but only in the contralateral cerebellar cortex. During the phase of partial motor recovery, lCMRGlc is incompletely restored in many of the thalamic nuclei ipsilateral to the ablation and completely restored in the contralateral nuclei. In the brainstem and deep cerebellar nuclei, poor to moderate recovery occurs bilaterally. Moderate recovery occurs in the contralateral cerebellar cortex. The findings demonstrate that a unilateral cerebral cortical lesion strongly affects lCMRGlc in the thalamus ipsilaterally and in the cerebellar cortex contralaterally, but in the brainstem bilaterally. Partial recovery of lCMRGlc accompanies the progressive motor recovery. The structures affected include those with direct, and also those with indirect, connections to the areas ablated.

  12. Relationship between regional brain glucose metabolism and temperament factor of personality

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Soo; Lee, Eun Ju; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2005-07-01

    Temperament factor of personality has been considered to have correlation with activity in a specific central monoaminergic system. In an attempt to explore neuronal substrate of biogenetic personality traits, we examined the relationship between regional brain glucose metabolism and temperament factor of personality. Twenty right-handed healthy subjects (age, 24{+-}4 yr: 10 females and 10 males) were studied with FDG PET. Their temperaments were assessed using the Temperament and Character Inventory (TCI), which consisted of four temperament factors (harm avoidance (HA), novelty seeking (NS), reward dependence (RD), persistency) and three personality factors. The relationship between regional glucose metabolism and each temperament score was tested using SPM99 (P < 0.005, uncorrected). NS score was negatively correlated with glucose metabolism in the frontal areas, insula, and superior temporal gyrus mainly in the right hemisphere. Positive correlation between NS score and glucose metabolism was observed in the left superior temporal gyrus. HA score showed negative correlation with glucose metabolism in the middle and orbitofrontal gyri as well as in the parahippocampal gyrus. RD score was positively correlated with glucose metabolism in the left middle frontal gyrus and negative correlated in the posterior cingulate gyrus and caudate nucleus. We identified the relationship between regional brain glucose metabolism and temperamental personality trait. Each temperament factor had a relation with functions of specific brain areas. These results help understand biological background of personality and specific feedback circuits associated with each temperament factor.

  13. INPP4B-mediated tumor resistance is associated with modulation of glucose metabolism via hexokinase 2 regulation in laryngeal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Min, Joong Won [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Kwang Il [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Hyun-Ah; Kim, Eun-Kyu; Noh, Woo Chul [Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeon, Hong Bae [Biomedical Research Institute, MEDIPOST Co., Ltd., Seoul (Korea, Republic of); Cho, Dong-Hyung [Graduate School of East-West Medical Science, Kyung Hee University, Gyeonggi-do (Korea, Republic of); Oh, Jeong Su [Department of Genetic Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Park, In-Chul; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Jae-Sung, E-mail: jaesung@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2013-10-11

    Highlights: •HIF-1α-regulated INPP4B enhances glycolysis. •INPP4B regulates aerobic glycolysis by inducing HK2 via Akt-mTOR pathway. •Blockage of INPP4B and HK2 sensitizes radioresistant laryngeal cancer cells to radiation and anticancer drug. •INPP4B is associated with HK2 in human laryngeal cancer tissues. -- Abstract: Inositol polyphosphate 4-phosphatase type II (INPP4B) was recently identified as a tumor resistance factor in laryngeal cancer cells. Herein, we show that INPP4B-mediated resistance is associated with increased glycolytic phenotype. INPP4B expression was induced by hypoxia and irradiation. Intriguingly, overexpression of INPP4B enhanced aerobic glycolysis. Of the glycolysis-regulatory genes, hexokinase 2 (HK2) was mainly regulated by INPP4B and this regulation was mediated through the Akt-mTOR pathway. Notably, codepletion of INPP4B and HK2 markedly sensitized radioresistant laryngeal cancer cells to irradiation or anticancer drug. Moreover, INPP4B was significantly associated with HK2 in human laryngeal cancer tissues. Therefore, these results suggest that INPP4B modulates aerobic glycolysis via HK2 regulation in radioresistant laryngeal cancer cells.

  14. Metabolic Effects of Glucose-Fructose Co-Ingestion Compared to Glucose Alone during Exercise in Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Lia Bally

    2017-02-01

    Full Text Available This paper aims to compare the metabolic effects of glucose-fructose co-ingestion (GLUFRU with glucose alone (GLU in exercising individuals with type 1 diabetes mellitus. Fifteen male individuals with type 1 diabetes (HbA1c 7.0% ± 0.6% (53 ± 7 mmol/mol underwent a 90 min iso-energetic continuous cycling session at 50% VO2max while ingesting combined glucose-fructose (GLUFRU or glucose alone (GLU to maintain stable glycaemia without insulin adjustment. GLUFRU and GLU were labelled with 13C-fructose and 13C-glucose, respectively. Metabolic assessments included measurements of hormones and metabolites, substrate oxidation, and stable isotopes. Exogenous carbohydrate requirements to maintain stable glycaemia were comparable between GLUFRU and GLU (p = 0.46. Fat oxidation was significantly higher (5.2 ± 0.2 vs. 2.6 ± 1.2 mg·kg−1·min−1, p < 0.001 and carbohydrate oxidation lower (18.1 ± 0.8 vs. 24.5 ± 0.8 mg·kg−1·min−1 p < 0.001 in GLUFRU compared to GLU, with decreased muscle glycogen oxidation in GLUFRU (10.2 ± 0.9 vs. 17.5 ± 1.0 mg·kg−1·min−1, p < 0.001. Lactate levels were higher (2.2 ± 0.2 vs. 1.8 ± 0.1 mmol/L, p = 0.012 in GLUFRU, with comparable counter-regulatory hormones between GLUFRU and GLU (p > 0.05 for all. Glucose and insulin levels, and total glucose appearance and disappearance were comparable between interventions. Glucose-fructose co-ingestion may have a beneficial impact on fuel metabolism in exercising individuals with type 1 diabetes without insulin adjustment, by increasing fat oxidation whilst sparing glycogen.

  15. Acute overexpression of lactate dehydrogenase-A perturbs beta-cell mitochondrial metabolism and insulin secretion.

    Science.gov (United States)

    Ainscow, E K; Zhao, C; Rutter, G A

    2000-07-01

    Islet beta-cells express low levels of lactate dehydrogenase and have high glycerol phosphate dehydrogenase activity. To determine whether this configuration favors oxidative glucose metabolism via mitochondria in the beta-cell and is important for beta-cell metabolic signal transduction, we have determined the effects on glucose metabolism and insulin secretion of acute overexpression of the skeletal muscle isoform of lactate dehydrogenase (LDH)-A. Monitored in single MIN6 beta-cells, LDH hyperexpression (achieved by intranuclear cDNA microinjection or adenoviral infection) diminished the response to glucose of both phases of increases in mitochondrial NAD(P)H, as well as increases in mitochondrial membrane potential, cytosolic free ATP, and cystolic free Ca2+. These effects were observed at all glucose concentrations, but were most pronounced at submaximal glucose levels. Correspondingly, adenoviral vector-mediated LDH-A overexpression reduced insulin secretion stimulated by 11 mmol/l glucose and the subsequent response to stimulation with 30 mmol/l glucose, but it was without significant effect when the concentration of glucose was raised acutely from 3 to 30 mmol/l. Thus, overexpression of LDH activity interferes with normal glucose metabolism and insulin secretion in the islet beta-cell type, and it may therefore be directly responsible for insulin secretory defects in some forms of type 2 diabetes. The results also reinforce the view that glucose-derived pyruvate metabolism in the mitochondrion is critical for glucose-stimulated insulin secretion in the beta-cell.

  16. Comparative Metabolic Flux Profiling of Melanoma Cell Lines

    Science.gov (United States)

    Scott, David A.; Richardson, Adam D.; Filipp, Fabian V.; Knutzen, Christine A.; Chiang, Gary G.; Ronai, Ze'ev A.; Osterman, Andrei L.; Smith, Jeffrey W.

    2011-01-01

    Metabolic rewiring is an established hallmark of cancer, but the details of this rewiring at a systems level are not well characterized. Here we acquire this insight in a melanoma cell line panel by tracking metabolic flux using isotopically labeled nutrients. Metabolic profiling and flux balance analysis were used to compare normal melanocytes to melanoma cell lines in both normoxic and hypoxic conditions. All melanoma cells exhibited the Warburg phenomenon; they used more glucose and produced more lactate than melanocytes. Other changes were observed in melanoma cells that are not described by the Warburg phenomenon. Hypoxic conditions increased fermentation of glucose to lactate in both melanocytes and melanoma cells (the Pasteur effect). However, metabolism was not strictly glycolytic, as the tricarboxylic acid (TCA) cycle was functional in all melanoma lines, even under hypoxia. Furthermore, glutamine was also a key nutrient providing a substantial anaplerotic contribution to the TCA cycle. In the WM35 melanoma line glutamine was metabolized in the “reverse” (reductive) direction in the TCA cycle, particularly under hypoxia. This reverse flux allowed the melanoma cells to synthesize fatty acids from glutamine while glucose was primarily converted to lactate. Altogether, this study, which is the first comprehensive comparative analysis of metabolism in melanoma cells, provides a foundation for targeting metabolism for therapeutic benefit in melanoma. PMID:21998308

  17. Glucose metabolism and kinetics of phosphorus removal by the fermentative bacterium Microlunatus phosphovorus.

    Science.gov (United States)

    Santos, M M; Lemos, P C; Reis, M A; Santos, H

    1999-09-01

    Phosphorus and carbon metabolism in Microlunatus phosphovorus was investigated by using a batch reactor to study the kinetics of uptake and release of extracellular compounds, in combination with (31)P and (13)C nuclear magnetic resonance (NMR) to characterize intracellular pools and to trace the fate of carbon substrates through the anaerobic and aerobic cycles. The organism was subjected to repetitive anaerobic and aerobic cycles to induce phosphorus release and uptake in a sequential batch reactor; an ultrafiltration membrane module was required since cell suspensions did not sediment. M. phosphovorus fermented glucose to acetate via an Embden-Meyerhof pathway but was unable to grow under anaerobic conditions. A remarkable time shift was observed between the uptake of glucose and excretion of acetate, resulting in an intracellular accumulation of acetate. The acetate produced was oxidized in the subsequent aerobic stage. Very high phosphorus release and uptake rates were measured, 3.34 mmol g of cell(-1) h(-1) and 1.56 mmol g of cell(-1) h(-1), respectively, values only comparable with those determined in activated sludge. In the aerobic period, growth was strictly dependent on the availability of external phosphate. Natural abundance (13)C NMR showed the presence of reserves of glutamate and trehalose in cell suspensions. Unexpectedly, [1-(13)C]glucose was not significantly channeled to the synthesis of internal reserves in the anaerobic phase, and acetate was not during the aerobic stage, although the glutamate pool became labeled via the exchange with intermediates of the tricarboxylic acid cycle at the level of glutamate dehydrogenase. The intracellular pool of glutamate increased under anaerobic conditions and decreased during the aerobic period. The contribution of M. phosphovorus for phosphorus removal in wastewater treatment plants is discussed on the basis of the metabolic features disclosed by this study.

  18. High-density lipoprotein modulates glucose metabolism in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Drew, Brian G; Duffy, Stephen J; Formosa, Melissa F

    2009-01-01

    kinase kinase and the AMP-activated protein kinase pathway. CONCLUSIONS: rHDL reduced plasma glucose in patients with type 2 diabetes mellitus by increasing plasma insulin and activating AMP-activated protein kinase in skeletal muscle. These findings suggest a role for HDL-raising therapies beyond......BACKGROUND: Low plasma high-density lipoprotein (HDL) is associated with elevated cardiovascular risk and aspects of the metabolic syndrome. We hypothesized that HDL modulates glucose metabolism via elevation of plasma insulin and through activation of the key metabolic regulatory enzyme, AMP...... baseline occurred during rHDL than during placebo (at 4 hours rHDL=-2.6+/-0.4; placebo=-2.1+/-0.3 mmol/L; P=0.018). rHDL increased plasma insulin (at 4 hours rHDL=3.4+/-10.0; placebo= -19.2+/-7.4 pmol/L; P=0.034) and also the homeostasis model assessment beta-cell function index (at 4 hours rHDL=18...

  19. Association between dopamine D4 receptor polymorphism and age related changes in brain glucose metabolism.

    Directory of Open Access Journals (Sweden)

    Nora D Volkow

    Full Text Available Aging is associated with reductions in brain glucose metabolism in some cortical and subcortical regions, but the rate of decrease varies significantly between individuals, likely reflecting genetic and environmental factors and their interactions. Here we test the hypothesis that the variant of the dopamine receptor D4 (DRD4 gene (VNTR in exon 3, which has been associated with novelty seeking and sensitivity to environmental stimuli (negative and positive including the beneficial effects of physical activity on longevity, influence the effects of aging on the human brain. We used positron emission tomography (PET and [(18F]fluoro-D-glucose ((18FDG to measure brain glucose metabolism (marker of brain function under baseline conditions (no stimulation in 82 healthy individuals (age range 22-55 years. We determined their DRD4 genotype and found an interaction with age: individuals who did not carry the 7-repeat allele (7R-, n = 53 had a significant (p<0.0001 negative association between age and relative glucose metabolism (normalized to whole brain glucose metabolism in frontal (r = -0.52, temporal (r = -0.51 and striatal regions (r = -0.47, p<0.001; such that older individuals had lower metabolism than younger ones. In contrast, for carriers of the 7R allele (7R+ n = 29, these correlations with age were not significant and they only showed a positive association with cerebellar glucose metabolism (r = +0.55; p = 0.002. Regression slopes of regional brain glucose metabolism with age differed significantly between the 7R+ and 7R- groups in cerebellum, inferior temporal cortex and striatum. These results provide evidence that the DRD4 genotype might modulate the associations between regional brain glucose metabolism and age and that the carriers of the 7R allele appear to be less sensitive to the effects of age on brain glucose metabolism.

  20. Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

    NARCIS (Netherlands)

    Cutts, DA; Maguire, RP; Leenders, KL; Spyrou, NM

    2004-01-01

    In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. This study determines whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was exa

  1. High-Density Lipoprotein Modulates Glucose Metabolism in Patients With Type 2 Diabetes Mellitus

    NARCIS (Netherlands)

    Drew, Brian G.; Duffy, Stephen J.; Formosa, Melissa F.; Natoli, Alaina K.; Henstridge, Darren C.; Penfold, Sally A.; Thomas, Walter G.; Mukhamedova, Nigora; de Courten, Barbora; Forbes, Josephine M.; Yap, Felicia Y.; Kaye, David M.; van Hall, Gerrit; Febbraio, Mark A.; Kemp, Bruce E.; Sviridov, Dmitri; Steinberg, Gregory R.; Kingwell, Bronwyn A.

    2009-01-01

    Background-Low plasma high-density lipoprotein (HDL) is associated with elevated cardiovascular risk and aspects of the metabolic syndrome. We hypothesized that HDL modulates glucose metabolism via elevation of plasma insulin and through activation of the key metabolic regulatory enzyme, AMP-activat

  2. Profiling sulfation/epimerization pattern of full-length heparan sulfate by NMR following cell culture 13C-glucose metabolic labeling.

    Science.gov (United States)

    Pegeot, Mathieu; Sadir, Rabia; Eriksson, Inger; Kjellen, Lena; Simorre, Jean-Pierre; Gans, Pierre; Lortat-Jacob, Hugues

    2015-02-01

    Through its ability to interact with proteins, heparan sulfate (HS) fulfills a large variety of functions. Protein binding depends on the level of HS sulfation and epimerization which are cell specific and dynamically regulated. Characterization of this molecule, however, has been restricted to oligosaccharide fragments available in large amount for structural investigation or to sulfate distribution through compositional analysis. Here we developed a (1)H-(13)C 2D NMR-based approach, directly performed on HS isolated from (13)C-labeled cells. By integrating the peak volumes measured at different chemical shifts, this non-destructive analysis allows us to determine both the sulfation and the iduronic/glucuronic profiles of the polysaccharide. Applied to wild-type and N-deacetylase/N-sulfotransferase-deficient fibroblasts as well as to epithelial cells differentiation, it also gives insights into the functional relationships existing between HS biosynthetic enzymes. This approach should be of significant interest to better understand HS changes that occur through physiologic regulations or during pathological development.

  3. Delta9-tetrahydrocannabinol stimulates glucose utilization in C6 glioma cells.

    Science.gov (United States)

    Sánchez, C; Velasco, G; Guzmán, M

    1997-08-29

    The present work was undertaken to study the metabolic response of C6 glioma cells to physiologically relevant doses of delta9-tetrahydrocannabinol (THC), the major active component of marijuana. At those concentrations (i.e. nanomolar range), THC produced a dose-dependent increase in the rates of glucose oxidation to CO2 and glucose incorporation into phospholipids and glycogen. The THC-induced stimulation of glucose utilization was (i) dose-dependent up to 100 nM THC, (ii) mimicked by the synthetic cannabinoid HU-210, and (iii) prevented by pertussis toxin and the CB1 receptor antagonist SR141716A. In contrast to THC, forskolin markedly depressed CO2 production, phospholipid synthesis and glycogen synthesis from glucose. The forskolin-induced inhibition of glucose utilization was (i) mimicked by dibutyryl-cAMP, and (ii) prevented by THC, HU-210 and H-7, an inhibitor of the cAMP-dependent protein kinase. Likewise, THC was able to antagonize in part the forskolin-induced elevation of intracellular cAMP concentration, and this antagonistic effect was prevented by SR141716A. However, THC per se did not affect basal cAMP concentration. Results thus indicate that physiologically relevant doses of THC stimulate glucose metabolism in C6 glioma cells through a cannabinoid receptor-mediated process. Although cannabinoid receptors may be coupled to inhibition of adenylyl cyclase in C6 glioma cells, this does not seem to be the mechanism involved in the THC-induced stimulation of glucose metabolism.

  4. A glucose biofuel cell implanted in rats.

    Science.gov (United States)

    Cinquin, Philippe; Gondran, Chantal; Giroud, Fabien; Mazabrard, Simon; Pellissier, Aymeric; Boucher, François; Alcaraz, Jean-Pierre; Gorgy, Karine; Lenouvel, François; Mathé, Stéphane; Porcu, Paolo; Cosnier, Serge

    2010-05-04

    Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF). Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO) and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 microW mL(-1), which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications.

  5. A glucose biofuel cell implanted in rats.

    Directory of Open Access Journals (Sweden)

    Philippe Cinquin

    Full Text Available Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs, are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF. Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 microW mL(-1, which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications.

  6. Interleukin-6 directly increases glucose metabolism in resting human skeletal muscle

    DEFF Research Database (Denmark)

    Glund, Stephan; Deshmukh, Atul; Long, Yun Chau

    2007-01-01

    suggested to promote insulin-mediated glucose utilization. In this study, we determined the direct effects of IL-6 on glucose transport and signal transduction in human skeletal muscle. Skeletal muscle strips were prepared from vastus lateralis biopsies obtained from 22 healthy men. Muscle strips were...... incubated with or without IL-6 (120 ng/ml). We found that IL-6 increased glucose transport in human skeletal muscle 1.3-fold (P ... exposure increases glucose metabolism in resting human skeletal muscle. Insulin-stimulated glucose transport and insulin signaling were unchanged after IL-6 exposure....

  7. The Effect of Selenium Supplementation on Glucose Homeostasis and the Expression of Genes Related to Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Ewa Jablonska

    2016-12-01

    Full Text Available The aim of the study was to evaluate the effect of selenium supplementation on the expression of genes associated with glucose metabolism in humans, in order to explain the unclear relationship between selenium and the risk of diabetes. For gene expression analysis we used archival samples of cDNA from 76 non-diabetic subjects supplemented with selenium in the previous study. The supplementation period was six weeks and the daily dose of selenium was 200 µg (as selenium yeast. Blood for mRNA isolation was collected at four time points: before supplementation, after two and four weeks of supplementation, and after four weeks of washout. The analysis included 15 genes encoding selected proteins involved in insulin signaling and glucose metabolism. In addition, HbA1c and fasting plasma glucose were measured at three and four time points, respectively. Selenium supplementation was associated with a significantly decreased level of HbA1c but not fasting plasma glucose (FPG and significant down-regulation of seven genes: INSR, ADIPOR1, LDHA, PDHA, PDHB, MYC, and HIF1AN. These results suggest that selenium may affect glycemic control at different levels of regulation, linked to insulin signaling, glycolysis, and pyruvate metabolism. Further research is needed to investigate mechanisms of such transcriptional regulation and its potential implication in direct metabolic effects.

  8. The Effect of Selenium Supplementation on Glucose Homeostasis and the Expression of Genes Related to Glucose Metabolism

    Science.gov (United States)

    Jablonska, Ewa; Reszka, Edyta; Gromadzinska, Jolanta; Wieczorek, Edyta; Krol, Magdalena B.; Raimondi, Sara; Socha, Katarzyna; Borawska, Maria H.; Wasowicz, Wojciech

    2016-01-01

    The aim of the study was to evaluate the effect of selenium supplementation on the expression of genes associated with glucose metabolism in humans, in order to explain the unclear relationship between selenium and the risk of diabetes. For gene expression analysis we used archival samples of cDNA from 76 non-diabetic subjects supplemented with selenium in the previous study. The supplementation period was six weeks and the daily dose of selenium was 200 µg (as selenium yeast). Blood for mRNA isolation was collected at four time points: before supplementation, after two and four weeks of supplementation, and after four weeks of washout. The analysis included 15 genes encoding selected proteins involved in insulin signaling and glucose metabolism. In addition, HbA1c and fasting plasma glucose were measured at three and four time points, respectively. Selenium supplementation was associated with a significantly decreased level of HbA1c but not fasting plasma glucose (FPG) and significant down-regulation of seven genes: INSR, ADIPOR1, LDHA, PDHA, PDHB, MYC, and HIF1AN. These results suggest that selenium may affect glycemic control at different levels of regulation, linked to insulin signaling, glycolysis, and pyruvate metabolism. Further research is needed to investigate mechanisms of such transcriptional regulation and its potential implication in direct metabolic effects. PMID:27983572

  9. Significance of insulin for glucose metabolism in skeletal muscle during contractions

    DEFF Research Database (Denmark)

    Hespel, P; Vergauwen, Lieven; Vandenberghe, K

    1996-01-01

    is effected primarily via mechanisms exerted within the muscle cell related to the contractile activity per se. Yet contractions become a more potent stimulus of muscle glucose uptake as the plasma insulin level is increased. In addition, enhanced glucose delivery to muscle, which during exercise...... is essentially effected via increased blood flow, significantly contributes to stimulate glucose uptake. Again, however, increased glucose delivery appears to be a more potent stimulus of muscle glucose uptake as the circulating insulin level is increased. Furthermore, contractions and elevated flow prove......Glucose uptake rate in active skeletal muscles is markedly increased during exercise. This increase reflects a multifactorial process involving both local and systemic mechanisms that cooperate to stimulate glucose extraction and glucose delivery to the muscle cells. Increased glucose extraction...

  10. Impact of switching from lopinavir/ritonavir to boosted and un-boosted atazanavir on glucose metabolism: the ATAzanavir & GLUcose metabolism (ATAGLU) study.

    Science.gov (United States)

    d'Ettorre, Gabriella; Ceccarelli, Giancarlo; Zaccarelli, Mauro; Ascoli-Bartoli, Tommaso; Bianchi, Luigi; Bellelli, Valeria; De Girolamo, Gabriella; Serafino, Sara; Giustini, Noemi; Mastroianni, Claudio M; Vullo, Vincenzo

    2016-07-01

    Previous studies have reported that protease inhibitors (PIs) can contribute to glycaemic alterations. However, there are few trials examining the direct effect of a single PI. The objective of the study was to evaluate the modifications of glucose and lipid profiles after a switch from lopinavir/ritonavir (LPV/r) to atazanavir, used as ritonavir-boosted (ATV/r) or un-boosted. We conducted a retrospective observational cohort study on the effect of ATV/(r) on glycaemic metabolism (ATAGLU) in patients with undetectable levels of HIV-RNA who switched from LPV/r. In total, 235 patients treated for 48 weeks with LPV/r plus two nucleoside reverse transcriptase inhibitors (NRTIs) and with undetectable HIV-RNA were included: 134 continued LPV/r after the initial 48 weeks and 101 switched to ATV(/r) (18.3% to ATV; 24.7% to ATV/r). A significant decrease in mean glucose level and insulin resistance was observed in patients who switched to ATV(/r). The mean cholesterol triglyceride levels increased in the LPV/r group and decreased among the patients who switched. A significant increase of CD4 T cells with undetectable levels of HIV-RNA was observed in all groups. The long-term results obtained in this real-life study suggest that patients who have achieved initial suppression on a regimen including LPV/r + two NRTIs can switch to ATV/(r) + two NRTIs with an improvement in lipid and glycaemic metabolism.

  11. Alleviation of glucose repression of maltose metabolism by MIG1 disruption in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B.

    1996-01-01

    The MIG1 gene was disrupted in a haploid laboratory strain (B224) and in an industrial polyploid strain (DGI 342) of Saccharomyces cerevisiae. The alleviation of glucose repression of the expression of MAL genes and alleviation of glucose control of maltose metabolism were investigated in batch...... cultivations on glucose-maltose mixtures. In the MIG1-disrupted haploid strain, glucose repression was partly alleviated; i.e., maltose metabolism was initiated at higher glucose concentrations than in the corresponding wild-type strain. In contrast, the polyploid Delta mig1 strain exhibited an even more...... of glucose repression of the SUC genes. The disruption of MIG1 was shown to bring about pleiotropic effects, manifested in changes in the pattern of secreted metabolites and in the specific growth rate....

  12. The Rab-GTPase-activating protein TBC1D1 regulates skeletal muscle glucose metabolism

    DEFF Research Database (Denmark)

    Szekeres, Ferenc; Chadt, Alexandra; Tom, Robby Z

    2012-01-01

    The Rab-GTPase-activating protein TBC1D1 has emerged as a novel candidate involved in metabolic regulation. Our aim was to determine whether TBC1D1 is involved in insulin as well as energy-sensing signals controlling skeletal muscle metabolism. TBC1D1-deficient congenic B6.SJL-Nob1.10 (Nob1.10(SJL...... be explained partly by a 50% reduction in GLUT4 protein, since proximal signaling at the level of Akt, AMPK, and acetyl-CoA carboxylase (ACC) was unaltered. Paradoxically, in vivo insulin-stimulated 2-deoxyglucose uptake was increased in EDL and tibialis anterior muscle from TBC1D1-deficient mice......)) and wild-type littermates were studied. Glucose and insulin tolerance, glucose utilization, hepatic glucose production, and tissue-specific insulin-mediated glucose uptake were determined. The effect of insulin, AICAR, or contraction on glucose transport was studied in isolated skeletal muscle. Glucose...

  13. Clinical observation of glucose metabolism disorders in elderly patients with obstructive sleep apnea disorder

    Institute of Scientific and Technical Information of China (English)

    张蔷

    2013-01-01

    Objective To explore the correlation between obstructive sleep apnea hypoventilation syndrome (OSAHS) and glucose metabolism disorders in patients without diabetes mellitus.Methods A total of 88 patients with OSAHS but without diabetes mellitus from 2009 to 2011 in

  14. Assessment of regional glucose metabolism in aging brain and dementia with positron-emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Reivich, M.; Alavi, A.; Ferris, S.; Christman, D.; Fowler, J.; MacGregor, R.; Farkas, T.; Greenberg, J.; Dann, R.; Wolf, A.

    1981-01-01

    This paper explores the alterations in regional glucose metabolism that occur in elderly subjects and those with senile dementia compared to normal young volunteers. Results showed a tendency for the frontal regions to have a lower metabolic rate in patients with dementia although this did not reach the level of significance when compared to the elderly control subjects. The changes in glucose metabolism were symmetrical in both the left and right hemispheres. There was a lack of correlation between the mean cortical metabolic rates for glucose and the global mental function in the patients with senile dementia. This is at variance with most of the regional cerebral blood flow data that has been collected. This may be partly related to the use of substrates other than glucose by the brain in elderly and demented subjects. (PSB)

  15. (p)ppGpp, a Small Nucleotide Regulator, Directs the Metabolic Fate of Glucose in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Lee, Kang-Mu; Bari, Wasimul; Raskin, David M; Yoon, Sang Sun

    2015-05-22

    When V. cholerae encounters nutritional stress, it activates (p)ppGpp-mediated stringent response. The genes relA and relV are involved in the production of (p)ppGpp, whereas the spoT gene encodes an enzyme that hydrolyzes it. Herein, we show that the bacterial capability to produce (p)ppGpp plays an essential role in glucose metabolism. The V. cholerae mutants defective in (p)ppGpp production (i.e. ΔrelAΔrelV and ΔrelAΔrelVΔspoT mutants) lost their viability because of uncontrolled production of organic acids, when grown with extra glucose. In contrast, the ΔrelAΔspoT mutant, a (p)ppGpp overproducer strain, exhibited better growth in the presence of the same glucose concentration. An RNA sequencing analysis demonstrated that transcriptions of genes consisting of an operon for acetoin biosynthesis were markedly elevated in N16961, a seventh pandemic O1 strain, but not in its (p)ppGpp(0) mutant during glucose-stimulated growth. Transposon insertion in acetoin biosynthesis gene cluster resulted in glucose-induced loss of viability of the ΔrelAΔspoT mutant, further suggesting the crucial role of acetoin production in balanced growth under glucose-rich environments. Additional deletion of the aphA gene, encoding a negative regulator for acetoin production, failed to rescue the (p)ppGpp(0) mutant from the defective glucose-mediated growth, suggesting that (p)ppGpp-mediated acetoin production occurs independent of the presence of AphA. Overall, our results reveal that (p)ppGpp, in addition to its well known role as a stringent response mediator, positively regulates acetoin production that contributes to the successful glucose metabolism and consequently the proliferation of V. cholerae cells under a glucose-rich environment, a condition that may mimic the human intestine.

  16. Metabolic Fate of Fructose Ingested with and without Glucose in a Mixed Meal

    OpenAIRE

    Fanny Theytaz; Sara de Giorgi; Leanne Hodson; Nathalie Stefanoni; Valentine Rey; Philippe Schneiter; Vittorio Giusti; Luc Tappy

    2014-01-01

    Ingestion of pure fructose stimulates de novo lipogenesis and gluconeogenesis. This may however not be relevant to typical nutritional situations, where fructose is invariably ingested with glucose. We therefore assessed the metabolic fate of fructose incorporated in a mixed meal without or with glucose in eight healthy volunteers. Each participant was studied over six hours after the ingestion of liquid meals containing either 13C-labelled fructose, unlabeled glucose, lipids and protein (Fr...

  17. Complex Patterns of Metabolic and Ca2+ Entrainment in Pancreatic Islets by Oscillatory Glucose

    OpenAIRE

    Pedersen, Morten Gram; Mosekilde, Erik; Polonsky, Kenneth S.; Luciani, Dan S.

    2013-01-01

    Glucose-stimulated insulin secretion is pulsatile and driven by intrinsic oscillations in metabolism, electrical activity, and Ca2+ in pancreatic islets. Periodic variations in glucose can entrain islet Ca2+ and insulin secretion, possibly promoting interislet synchronization. Here, we used fluorescence microscopy to demonstrate that glucose oscillations can induce distinct 1:1 and 1:2 entrainment of oscillations (one and two oscillations for each period of exogenous stimulus, respectively) i...

  18. Protein Kinase A Activation Promotes Cancer Cell Resistance to Glucose Starvation and Anoikis.

    Directory of Open Access Journals (Sweden)

    Roberta Palorini

    2016-03-01

    Full Text Available Cancer cells often rely on glycolysis to obtain energy and support anabolic growth. Several studies showed that glycolytic cells are susceptible to cell death when subjected to low glucose availability or to lack of glucose. However, some cancer cells, including glycolytic ones, can efficiently acquire higher tolerance to glucose depletion, leading to their survival and aggressiveness. Although increased resistance to glucose starvation has been shown to be a consequence of signaling pathways and compensatory metabolic routes activation, the full repertoire of the underlying molecular alterations remain elusive. Using omics and computational analyses, we found that cyclic adenosine monophosphate-Protein Kinase A (cAMP-PKA axis activation is fundamental for cancer cell resistance to glucose starvation and anoikis. Notably, here we show that such a PKA-dependent survival is mediated by parallel activation of autophagy and glutamine utilization that in concert concur to attenuate the endoplasmic reticulum (ER stress and to sustain cell anabolism. Indeed, the inhibition of PKA-mediated autophagy or glutamine metabolism increased the level of cell death, suggesting that the induction of autophagy and metabolic rewiring by PKA is important for cancer cellular survival under glucose starvation. Importantly, both processes actively participate to cancer cell survival mediated by suspension-activated PKA as well. In addition we identify also a PKA/Src mechanism capable to protect cancer cells from anoikis. Our results reveal for the first time the role of the versatile PKA in cancer cells survival under chronic glucose starvation and anoikis and may be a novel potential target for cancer treatment.

  19. Protein Kinase A Activation Promotes Cancer Cell Resistance to Glucose Starvation and Anoikis.

    Science.gov (United States)

    Palorini, Roberta; Votta, Giuseppina; Pirola, Yuri; De Vitto, Humberto; De Palma, Sara; Airoldi, Cristina; Vasso, Michele; Ricciardiello, Francesca; Lombardi, Pietro Paolo; Cirulli, Claudia; Rizzi, Raffaella; Nicotra, Francesco; Hiller, Karsten; Gelfi, Cecilia; Alberghina, Lilia; Chiaradonna, Ferdinando

    2016-03-01

    Cancer cells often rely on glycolysis to obtain energy and support anabolic growth. Several studies showed that glycolytic cells are susceptible to cell death when subjected to low glucose availability or to lack of glucose. However, some cancer cells, including glycolytic ones, can efficiently acquire higher tolerance to glucose depletion, leading to their survival and aggressiveness. Although increased resistance to glucose starvation has been shown to be a consequence of signaling pathways and compensatory metabolic routes activation, the full repertoire of the underlying molecular alterations remain elusive. Using omics and computational analyses, we found that cyclic adenosine monophosphate-Protein Kinase A (cAMP-PKA) axis activation is fundamental for cancer cell resistance to glucose starvation and anoikis. Notably, here we show that such a PKA-dependent survival is mediated by parallel activation of autophagy and glutamine utilization that in concert concur to attenuate the endoplasmic reticulum (ER) stress and to sustain cell anabolism. Indeed, the inhibition of PKA-mediated autophagy or glutamine metabolism increased the level of cell death, suggesting that the induction of autophagy and metabolic rewiring by PKA is important for cancer cellular survival under glucose starvation. Importantly, both processes actively participate to cancer cell survival mediated by suspension-activated PKA as well. In addition we identify also a PKA/Src mechanism capable to protect cancer cells from anoikis. Our results reveal for the first time the role of the versatile PKA in cancer cells survival under chronic glucose starvation and anoikis and may be a novel potential target for cancer treatment.

  20. Direct neuronal glucose uptake Heralds activity-dependent increases in cerebral metabolism

    DEFF Research Database (Denmark)

    Lundgaard, Iben; Li, Baoman; Xie, Lulu

    2015-01-01

    Metabolically, the brain is a highly active organ that relies almost exclusively on glucose as its energy source. According to the astrocyte-to-neuron lactate shuttle hypothesis, glucose is taken up by astrocytes and converted to lactate, which is then oxidized by neurons. Here we show, using two...

  1. Metabolomic profiling identifies potential pathways involved in the interaction of iron homeostasis with glucose metabolism

    Directory of Open Access Journals (Sweden)

    Lars Stechemesser

    2017-01-01

    Conclusions: Our data suggest that high serum ferritin concentrations are linked to impaired glucose homeostasis in subjects with the MetS. Iron excess is associated to distinct changes in the serum concentrations of phosphatidylcholine subsets. A pathway involving sarcosine and citrulline also may be involved in iron-induced impairment of glucose metabolism.

  2. Impact of 3-year lifestyle intervention on postprandial glucose metabolism : the SLIM study

    NARCIS (Netherlands)

    Roumen, C.; Corpeleijn, E.; Feskens, E. J. M.; Mensink, M.; Saris, W. H. M.; Blaak, E. E.

    2008-01-01

    Objective To determine the effect of a 3-year diet and exercise lifestyle intervention, based on general public health recommendations, on glucose tolerance, insulin resistance and metabolic cardiovascular risk factors in Dutch subjects with impaired glucose tolerance (IGT). Methods The study was a

  3. Physical activity energy expenditure vs cardiorespiratory fitness level in impaired glucose metabolism

    DEFF Research Database (Denmark)

    Lidegaard, Lærke P; Hansen, Anne-Louise Smidt; Johansen, Nanna B

    2015-01-01

    AIM/HYPOTHESIS: Little is known about the relative roles of physical activity energy expenditure (PAEE) and cardiorespiratory fitness (CRF) as determinants of glucose regulation. The aim of this study was to examine the associations of PAEE and CRF with markers of glucose metabolism, and to test...

  4. Regulation of glucose and glycogen metabolism during and after exercise

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Richter, Erik

    2012-01-01

    Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport...... in the post-exercise period which can result in an overshoot of intramuscular glycogen resynthesis post exercise (glycogen supercompensation)....

  5. Metabolic ketoacidosis with normal blood glucose: A rare complication of sodium–glucose cotransporter 2 inhibitors

    OpenAIRE

    Saad Ullah; Noman Khan; Hassan Zeb; Hassan Tahir

    2016-01-01

    Ketoacidosis is a significant and often a life-threatening complication of diabetes mellitus seen mostly in type 1 diabetes mellitus as well as occasionally in type 2 diabetes mellitus. Diabetic ketoacidosis usually manifests with high blood glucose more than 250 mg/dL, but euglycemic diabetic ketoacidosis is defined as ketoacidosis associated with blood glucose level less than 250 mg/dL. Normal blood glucose in such patients results in significant delay in diagnosis and management of diabeti...

  6. Glucose metabolism: focus on gut microbiota, the endocannabinoid system and beyond.

    Science.gov (United States)

    Cani, P D; Geurts, L; Matamoros, S; Plovier, H; Duparc, T

    2014-09-01

    The gut microbiota is now considered as a key factor in the regulation of numerous metabolic pathways. Growing evidence suggests that cross-talk between gut bacteria and host is achieved through specific metabolites (such as short-chain fatty acids) and molecular patterns of microbial membranes (lipopolysaccharides) that activate host cell receptors (such as toll-like receptors and G-protein-coupled receptors). The endocannabinoid (eCB) system is an important target in the context of obesity, type 2 diabetes (T2D) and inflammation. It has been demonstrated that eCB system activity is involved in the control of glucose and energy metabolism, and can be tuned up or down by specific gut microbes (for example, Akkermansia muciniphila). Numerous studies have also shown that the composition of the gut microbiota differs between obese and/or T2D individuals and those who are lean and non-diabetic. Although some shared taxa are often cited, there is still no clear consensus on the precise microbial composition that triggers metabolic disorders, and causality between specific microbes and the development of such diseases is yet to be proven in humans. Nevertheless, gastric bypass is most likely the most efficient procedure for reducing body weight and treating T2D. Interestingly, several reports have shown that the gut microbiota is profoundly affected by the procedure. It has been suggested that the consistent postoperative increase in certain bacterial groups such as Proteobacteria, Bacteroidetes and Verrucomicrobia (A. muciniphila) may explain its beneficial impact in gnotobiotic mice. Taken together, these data suggest that specific gut microbes modulate important host biological systems that contribute to the control of energy homoeostasis, glucose metabolism and inflammation in obesity and T2D.

  7. Convergence role of transcriptional coactivator p300 and apparent modification on HMCs metabolic memory induced by high glucose

    Directory of Open Access Journals (Sweden)

    Hong SU

    2013-03-01

    Full Text Available Objective  To investigate the protein expression of transcriptional coactivator p300, acetylated histone H3 (Ac-H3 and Ac-H4 in human renal mesangial cell (HMCs as imitative "metabolic memory" in vitro, and explore the potential role of convergence point of p300. Methods  The HMCs were divided into the following groups: ① High glucose metabolic memory model: normal glucose group (NG, 5.5mmol/L D-glucose×2d, high glucose group (HG, 25mmol/L D-glucose×2d, memory groups (M1, M2, M3, 25mmol/L D-glucose×2days + 5.5mmol/L D-glucose×3d, 6d or 9d, persisting normal glucose group (NG, 5.5mmol/L D-glucose×9d. ② Advanced glycation end products memory model: normal glucose group (NG, 5.5mmol/ L D-glucose×2d, NG+AGEs group (AGEs, 5.5mmol/L D-glucose+250µg/ml AGEs×2d; AGEs memory group (AGEs-M, 5.5mmol/L D-glucose + 250µg/ml AGEs×2d + 5.5mmol/L D-glucose×3d; BSA control group (NG+BSA, 5.5mmol/L D-glucose + 250µg/ml BSA×2d. ③ H2O2 was used to simulate oxidative stress memory model: normal glucose group (NG, 5.5mmol/L D-glucose×2d, NG+H2O2 group (H2O2, 5.5mmol/L D-glucose +100µmol/L H2O2×30min; H2O2 memory group [(5.5mmol/ L D-glucose + 100µmol/L H2O2×30min + 5.5mmol/L D-glucose×3d]; normal glucose control group (NG3, 5.5mmol/L D-glucose×3d. ④ Transfection with PKCβ2 memory model: normal glucose group (NG, 5.5mmol/L D-glucose×2d; high glucose group (HG, 25mmol/L D-glucose×2d; memory group (M, 25mmol/L D-glucose×2d + 5.5mmol/L D-glucose×3d; Ad5-null memory group (HN, 25mmol/L D-glucose + Ad5-null×2d + 5.5mmol/L D-glucose×3d; PKCβ2 memory group (PO, 25mmol/L D-glucose + Ad5-PKCβ2×2d + 5.5mmol/L D-glucose×3d; inhibitor of PKCβ2 memory group (PI, 25mmol/L D-glucose×2d + 10µmol/L CGP53353 + 5.5mmol/L D-glucose×3d. The expression of intracellular reactive oxygen species (ROS was detected by fluorescence microscope and fluorescence microplate reader. The expression levels of p300, Ac-H3, Ac-H4 and PKCβ2 proteins were

  8. Steviol Glycosides Modulate Glucose Transport in Different Cell Types

    Directory of Open Access Journals (Sweden)

    Benedetta Rizzo

    2013-01-01

    Full Text Available Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  9. Steviol glycosides modulate glucose transport in different cell types.

    Science.gov (United States)

    Rizzo, Benedetta; Zambonin, Laura; Angeloni, Cristina; Leoncini, Emanuela; Dalla Sega, Francesco Vieceli; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  10. Inhibition of fatty acid metabolism reduces human myeloma cells proliferation.

    Directory of Open Access Journals (Sweden)

    José Manuel Tirado-Vélez

    Full Text Available Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40-70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

  11. Damaging effects of hyperglycemia on cardiovascular function: spotlight on glucose metabolic pathways.

    Science.gov (United States)

    Mapanga, Rudo F; Essop, M Faadiel

    2016-01-15

    The incidence of cardiovascular complications associated with hyperglycemia is a growing global health problem. This review discusses the link between hyperglycemia and cardiovascular diseases onset, focusing on the role of recently emerging downstream mediators, namely, oxidative stress and glucose metabolic pathway perturbations. The role of hyperglycemia-mediated activation of nonoxidative glucose pathways (NOGPs) [i.e., the polyol pathway, hexosamine biosynthetic pathway, advanced glycation end products (AGEs), and protein kinase C] in this process is extensively reviewed. The proposal is made that there is a unique interplay between NOGPs and a downstream convergence of detrimental effects that especially affect cardiac endothelial cells, thereby contributing to contractile dysfunction. In this process the AGE pathway emerges as a crucial mediator of hyperglycemia-mediated detrimental effects. In addition, a vicious metabolic cycle is established whereby hyperglycemia-induced NOGPs further fuel their own activation by generating even more oxidative stress, thereby exacerbating damaging effects on cardiac function. Thus NOGP inhibition, and particularly that of the AGE pathway, emerges as a novel therapeutic intervention for the treatment of cardiovascular complications such as acute myocardial infarction in the presence hyperglycemia.

  12. Evaluation of Glucose Uptake in Normal and Cancer Cell Lines by Positron Emission Tomography.

    Science.gov (United States)

    Maddalena, Francesca; Lettini, Giacomo; Gallicchio, Rosj; Sisinni, Lorenza; Simeon, Vittorio; Nardelli, Anna; Venetucci, Angela Assunta; Storto, Giovanni; Landriscina, Matteo

    2015-01-01

    To date, there is no definitive demonstration of the utility of positron emission tomography (PET) in studying glucose metabolism in cultured cell lines. Thus, this study was designed to compare PET to more standardized methods for the quantitative assessment of glucose uptake in nontransformed and transformed living cells and to validate PET for metabolic studies in vitro. Human colon and breast carcinoma cell lines and mouse embryo fibroblasts were evaluated for [(18)F]fluorodeoxyglucose ([(18)F]FDG) uptake by PET and autoradiography and 2-deoxyglucose (2-DG) incorporation by colorimetric assay and analyzed for the radiotoxic effects of [(18)F]FDG and the expression levels of glucose transporters. Indeed, [(18)F]FDG incorporation on PET was comparable to [(18)F]FDG uptake by autoradiography and 2-DG incorporation by colorimetric assay, although radiotracer-based methods exhibited more pronounced differences between individual cell lines. As expected, these data correlated with glucose transporters 1 to 4 and hexokinase II expression in tumor cell lines and mouse fibroblasts. Notably, [(18)F]FDG incorporation resulted in low apoptotic rates, with fibroblasts being slightly more sensitive to radiotracer-induced cell death. The quantitative analysis of [(18)F]FDG uptake in living cells by PET represents a valuable and reproducible method to study tumor cell metabolism in vitro, being representative of the differences in the molecular profile of normal and tumor cell lines.

  13. Pregnancy and undernutrition alter glucose metabolic responses to insulin in sheep.

    Science.gov (United States)

    Petterson, J A; Dunshea, F R; Ehrhardt, R A; Bell, A W

    1993-07-01

    Nonpregnant and late-pregnant ditocous ewes were fed either to maintain zero energy balance in maternal tissues (fed) or at 50% of this level (underfed) for several weeks. Whole-body kinetics of glucose metabolism were measured under basal conditions, and the hyperinsulinemic, euglycemic clamp technique was used to define insulin-dose response profiles for several indices of whole-body glucose utilization, and for endogenous glucose production. Pregnancy increased and undernutrition decreased basal glucose entry rate (GER), glucose metabolic clearance rate (GMCR) and insulin-independent glucose utilization (IIGU). The consistent increment in IIGU of pregnant over nonpregnant ewes was comparable to previous estimates of uterine glucose uptake. Pregnancy resulted in higher plasma concentration for 50% maximal responses (ED50) to insulin of GER, GMCR, steady-state glucose infusion rate (SSGIR) to maintain euglycemia and insulin-dependent glucose utilization (IDGU). These changes were especially large in underfed pregnant ewes. Effects on the maximal response to insulin of these variables (Rmax) were relatively small (GMCR, IDGU) or nonsignificant (GER, SSGIR). Maximum insulin-induced suppression of endogenous glucose production was significantly lower due to undernutrition; neither Rmax nor ED50 for this response was affected by pregnancy. Insulin resistance in late-pregnant ewes is primarily due to decreased insulin sensitivity in (presumably) peripheral tissues, implying an alteration of receptor function or of early postreceptor signal transduction.

  14. Delivery-Corrected Imaging of Fluorescently-Labeled Glucose Reveals Distinct Metabolic Phenotypes in Murine Breast Cancer

    Science.gov (United States)

    Frees, Amy E.; Rajaram, Narasimhan; McCachren, Samuel S.; Fontanella, Andrew N.; Dewhirst, Mark W.; Ramanujam, Nimmi

    2014-01-01

    When monitoring response to cancer therapy, it is important to differentiate changes in glucose tracer uptake caused by altered delivery versus a true metabolic shift. Here, we propose an optical imaging method to quantify glucose uptake and correct for in vivo delivery effects. Glucose uptake was measured using a fluorescent D-glucose derivative 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-deoxy-D-glucose (2-NBDG) in mice implanted with dorsal skin flap window chambers. Additionally, vascular oxygenation (SO2) was calculated using only endogenous hemoglobin contrast. Results showed that the delivery factor proposed for correction, “RD”, reported on red blood cell velocity and injected 2-NBDG dose. Delivery-corrected 2-NBDG uptake (2-NBDG60/RD) inversely correlated with blood glucose in normal tissue, indicating sensitivity to glucose demand. We further applied our method in metastatic 4T1 and nonmetastatic 4T07 murine mammary adenocarcinomas. The ratio 2-NBDG60/RD was increased in 4T1 tumors relative to 4T07 tumors yet average SO2 was comparable, suggesting a shift toward a “Warburgian” (aerobic glycolysis) metabolism in the metastatic 4T1 line. In heterogeneous regions of both 4T1 and 4T07, 2-NBDG60/RD increased slightly but significantly as vascular oxygenation decreased, indicative of the Pasteur effect in both tumors. These data demonstrate the utility of delivery-corrected 2-NBDG and vascular oxygenation imaging for differentiating metabolic phenotypes in vivo. PMID:25526261

  15. Transcriptome profiling of brown adipose tissue during cold exposure reveals extensive regulation of glucose metabolism

    DEFF Research Database (Denmark)

    Hao, Qin; Yadav, Rachita; Basse, Astrid L.

    2015-01-01

    exposure, we propose a model for the intermediary glucose metabolism in activated BAT: 1) fluxes through glycolysis and the pentose phosphate pathway are induced, the latter providing reducing equivalents for de novo fatty acid synthesis; 2) glycerol synthesis from glucose is increased, facilitating...... metabolism, and the pentose phosphate pathway was observed in BAT from cold-exposed animals. In addition, glycerol-3-phosphate dehydrogenase 1 expression was induced in BAT from cold-challenged mice, suggesting increased synthesis of glycerol from glucose. Similarly, expression of lactate dehydrogenases...

  16. The direct effect of incretin hormones on glucose and glycerol metabolism and hemodynamics

    DEFF Research Database (Denmark)

    Karstoft, Kristian; Mortensen, Stefan; Knudsen, Sine H;

    2015-01-01

    The objective of this study was to assess the insulin-independent effects of incretin hormones on glucose and glycerol metabolism and hemodynamics under eu- and hyperglycemic conditions. Young, healthy males (n=10) underwent three trials in a randomized, controlled, cross-over study. Each trial...... consisted of a 2-stage (eu- and hyperglycemia) pancreatic clamp (using somatostatin to prevent endogenous insulin secretion). Glucose and lipid metabolism were measured via infusion of stable glucose and glycerol isotopic tracers. Hemodynamic variables (femoral, brachial and common carotid artery blood flow...... a higher femoral blood flow during hyperglycemia in GIP (vs. CON and GLP-1, Pmetabolism or hemodynamics during euglycemia. On contrary, during...

  17. The progression from a lower to a higher invasive stage of bladder cancer is associated with severe alterations in glucose and pyruvate metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Vanessa R. [CICS-UBI–Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Oliveira, Pedro F. [CICS-UBI–Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Department of Microscopy, Laboratory of Cell Biology and Unit for Multidisciplinary Research in Biomedicine, Abel Salazar Institute of Biomedical Sciences, University of Porto – UMIB/ICBAS/UP (Portugal); Nunes, Ana R.; Rocha, Cátia S. [CICS-UBI–Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Ramalhosa, Elsa; Pereira, José A. [Mountain Research Centre (CIMO), School of Agriculture, Polytechnic Institute of Bragança (Portugal); Alves, Marco G., E-mail: alvesmarc@gmail.com [CICS-UBI–Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal); Silva, Branca M., E-mail: bmcms@ubi.pt [CICS-UBI–Health Sciences Research Centre, University of Beira Interior, Covilhã (Portugal)

    2015-07-01

    Cancer cells present a particular metabolic behavior. We hypothesized that the progression of bladder cancer could be accompanied by changes in cells glycolytic profile. We studied two human bladder cancer cells, RT4 and TCCSUP, in which the latter represents a more invasive stage. The levels of glucose, pyruvate, alanine and lactate in the extracellular media were measured by Proton Nuclear Magnetic Resonance. The protein expression levels of glucose transporters 1 (GLUT1) and 3 (GLUT3), monocarboxylate transporter 4 (MCT4), phosphofructokinase-1 (PFK1), glutamic-pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) were determined. Our data showed that glucose consumption and GLUT3 levels were similar in both cell lines, but TCCSUP cells displayed lower levels of GLUT1 and PFK expression. An increase in pyruvate consumption, concordant with the higher levels of lactate and alanine production, was also detected in TCCSUP cells. Moreover, TCCSUP cells presented lower protein expression levels of GPT and LDH. These results illustrate that bladder cancer progression is associated with alterations in cells glycolytic profile, namely the switch from glucose to pyruvate consumption in the more aggressive stage. This may be useful to develop new therapies and to identify biomarkers for cancer progression. - Highlights: • Metabolic phenotype of less and high invasive bladder cancer cells was studied. • Bladder cancer progression involves alterations in cells glycolytic profile. • More invasive bladder cancer cells switch from glucose to pyruvate consumption. • Our results may help to identify metabolic biomarkers of bladder cancer progression.

  18. Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

    Directory of Open Access Journals (Sweden)

    Amanda Fraga

    Full Text Available Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3 and hexokinase (HexA genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

  19. Comparison of glucose and lipid metabolic gene expressions between fat and lean lines of rainbow trout after a glucose load.

    Directory of Open Access Journals (Sweden)

    Junyan Jin

    Full Text Available Two experimental rainbow trout lines developed through divergent selection for low (Lean 'L' line or high (Fat 'F' line muscle fat content were used as models to study the genetic determinism of fat depots. Previous nutritional studies suggested that the F line had a better capability to use glucose than the L line during feeding trials. Based on that, we put forward the hypothesis that F line has a greater metabolic ability to clear a glucose load effectively, compared to L line. In order to test this hypothesis, 250 mg/kg glucose was intraperitoneally injected to the two rainbow trout lines fasted for 48 h. Hyperglycemia was observed after glucose treatment in both lines without affecting the phosphorylation of AMPK (cellular energy sensor and Akt-TOR (insulin signaling components. Liver glucokinase and glucose-6-phosphate dehydrogenase expression levels were increased by glucose, whereas mRNA levels of β-oxidation enzymes (CPT1a, CPT1b, HOAD and ACO were down-regulated in the white skeletal muscle of both lines. Regarding the genotype effect, concordant with normoglycemia at 12 h after glucose treatment, higher muscle glycogen was found in F line compared to L line which exhibited hyperglycemia. Moreover, mRNA levels of hepatic glycolytic enzymes (GK, 6PFK and PK, gluconeogenic enzyme PEPCK and muscle fatty acid oxidation enzymes (CPT1a, CPT1b and HOAD were concurrently higher in the F line. Overall, these findings suggest that F line may have a better ability to maintain glucose homeostasis than L line.

  20. Tumor metabolism: cancer cells give and take lactate.

    Science.gov (United States)

    Semenza, Gregg L

    2008-12-01

    Tumors contain well-oxygenated (aerobic) and poorly oxygenated (hypoxic) regions, which were thought to utilize glucose for oxidative and glycolytic metabolism, respectively. In this issue of the JCI, Sonveaux et al. show that human cancer cells cultured under hypoxic conditions convert glucose to lactate and extrude it, whereas aerobic cancer cells take up lactate via monocarboxylate transporter 1 (MCT1) and utilize it for oxidative phosphorylation (see the related article beginning on page 3930). When MCT1 is inhibited, aerobic cancer cells take up glucose rather than lactate, and hypoxic cancer cells die due to glucose deprivation. Treatment of tumor-bearing mice with an inhibitor of MCT1 retarded tumor growth. MCT1 expression was detected exclusively in nonhypoxic regions of human cancer biopsy samples, and in combination, these data suggest that MCT1 inhibition holds potential as a novel cancer therapy.

  1. Metabolic ketoacidosis with normal blood glucose: A rare complication of sodium–glucose cotransporter 2 inhibitors

    Science.gov (United States)

    Ullah, Saad; Khan, Noman; Zeb, Hassan; Tahir, Hassan

    2016-01-01

    Ketoacidosis is a significant and often a life-threatening complication of diabetes mellitus seen mostly in type 1 diabetes mellitus as well as occasionally in type 2 diabetes mellitus. Diabetic ketoacidosis usually manifests with high blood glucose more than 250 mg/dL, but euglycemic diabetic ketoacidosis is defined as ketoacidosis associated with blood glucose level less than 250 mg/dL. Normal blood glucose in such patients results in significant delay in diagnosis and management of diabetic ketoacidosis, thus increasing mortality and morbidity. We present a case of euglycemic diabetic ketoacidosis secondary to canagliflozin in a type 2 diabetic patient. PMID:27928503

  2. Metabolic ketoacidosis with normal blood glucose: A rare complication of sodium–glucose cotransporter 2 inhibitors

    Directory of Open Access Journals (Sweden)

    Saad Ullah

    2016-11-01

    Full Text Available Ketoacidosis is a significant and often a life-threatening complication of diabetes mellitus seen mostly in type 1 diabetes mellitus as well as occasionally in type 2 diabetes mellitus. Diabetic ketoacidosis usually manifests with high blood glucose more than 250 mg/dL, but euglycemic diabetic ketoacidosis is defined as ketoacidosis associated with blood glucose level less than 250 mg/dL. Normal blood glucose in such patients results in significant delay in diagnosis and management of diabetic ketoacidosis, thus increasing mortality and morbidity. We present a case of euglycemic diabetic ketoacidosis secondary to canagliflozin in a type 2 diabetic patient.

  3. Analysis of CHO cells metabolic redistribution in a glutamate-based defined medium in continuous culture.

    Science.gov (United States)

    Altamirano, C; Illanes, A; Casablancas, A; Gámez, X; Cairó, J J; Gòdia, C

    2001-01-01

    The effect of glutamine replacement by glutamate and the balance between glutamate and glucose metabolism on the redistribution of t-PA-producing recombinant CHO cells metabolism is studied in a series of glucose shift down and shift up experiments in continuous culture. These experiments reveal the existence of multiple steady states, and experimental data are used to perform metabolic flux analysis to gain a better insight into cellular metabolism and its redistribution. Regulation of glucose feed rate promotes a higher efficiency of glucose and nitrogen source utilization, with lower production of metabolic byproducts, but this reduces t-PA specific production rate. This reduction under glucose limitation can be attributed to the fact that the cells are forced to efficiently utilize the carbon and energy source for growth, impairing the production of dispensable metabolites. It is, therefore, the combination of growth rate and carbon and energy source availability that determines the level of t-PA production in continuous culture.

  4. Effects of an oral insulin nanoparticle administration on hepatic glucose metabolism assessed by 13C and 2H isotopomer analysis

    NARCIS (Netherlands)

    Reis, C.P.; Neufeld, R.; Veiga, F.; Figueiredo, I.V.; Jones, J.; Soares, A.F.; Nunes, P.M.; Damg\\'e, C.; Carvalho, R.A.

    2012-01-01

    The purpose of this study was to evaluate hepatic glucose metabolism of diabetic induced rats after a daily oral load of insulin nanoparticles over 2 weeks. After the 2-week treatment, an oral glucose tolerance test was performed with [U-‘‘C] glucose and ‘H2O. Plasma glucose ‘H and ‘‘C enrichments w

  5. Effects of pituitary hormone deficiency on growth and glucose metabolism of the sheep fetus.

    Science.gov (United States)

    Fowden, A L; Forhead, A J

    2007-10-01

    Pituitary hormones are essential for normal growth and metabolic responsiveness after birth, but their role before birth remains unclear. This study examined the effects of hypophysectomizing fetal sheep on their growth and glucose metabolism during the late normal and extended periods of gestation, and on their metabolic response to maternal fasting for 48 h near term. Fetal hypophysectomy reduced crown rump length (CRL), limb lengths, and body weight but increased ponderal index relative to controls near normal term. It also lowered the daily rate of crown rump length increment uniformly from 35 d before, to 20 d after normal term. Hypophysectomized (HX) fetuses had normal weight-specific rates of umbilical uptake, utilization, and oxidation of glucose but lower rates of umbilical oxygen uptake than controls near term. All these metabolic rates were significantly less in HX fetuses during the extended period of gestation than in HX and intact fetuses near normal term. In contrast to controls, glucogenesis was negligible in HX fetuses during maternal fasting. Consequently, the rate of glucose utilization decreased significantly in fasted HX but not intact fetuses. Conversely, the rate of CO(2) production from glucose carbon decreased in fasted intact but not HX fetuses. Fetal hypophysectomy also prevented the fasting-induced increases in plasma cortisol and norepinephrine concentrations seen in controls. These findings demonstrate that the pituitary hormones are important in regulating the growth rate and adaptive responses of glucose metabolism to undernutrition in fetal sheep. They also suggest that fetal metabolism is altered when gestational length is extended.

  6. Cerebral glucose metabolism in Wernicke's, Broca's, and conduction aphasia

    Energy Technology Data Exchange (ETDEWEB)

    Metter, E.J.; Kempler, D.; Jackson, C.; Hanson, W.R.; Mazziotta, J.C.; Phelps, M.E.

    1989-01-01

    Cerebral glucose metabolism was evaluated in patients with either Wernicke's (N = 7), Broca's (N = 11), or conduction (N = 10) aphasia using /sup 18/F-2-fluoro-2-deoxy-D-glucose with positron emission tomography. The three aphasic syndromes differed in the degree of left-to-right frontal metabolic asymmetry, with Broca's aphasia showing severe asymmetry and Wernicke's aphasia mild-to-moderate metabolic asymmetry, while patients with conduction aphasia were metabolically symmetric. On the other hand, the three syndromes showed the same degree of metabolic decline in the left temporal region. The parietal region appeared to separate conduction aphasia from both Broca's and Wernicke's aphasias. Common aphasic features in the three syndromes appear to be due to common changes in the temporal region, while unique features were associated with frontal and parietal metabolic differences.

  7. Glutamate Acts as a Key Signal Linking Glucose Metabolism to Incretin/cAMP Action to Amplify Insulin Secretion

    Directory of Open Access Journals (Sweden)

    Ghupurjan Gheni

    2014-10-01

    Full Text Available Incretins, hormones released by the gut after meal ingestion, are essential for maintaining systemic glucose homeostasis by stimulating insulin secretion. The effect of incretins on insulin secretion occurs only at elevated glucose concentrations and is mediated by cAMP signaling, but the mechanism linking glucose metabolism and cAMP action in insulin secretion is unknown. We show here, using a metabolomics-based approach, that cytosolic glutamate derived from the malate-aspartate shuttle upon glucose stimulation underlies the stimulatory effect of incretins and that glutamate uptake into insulin granules mediated by cAMP/PKA signaling amplifies insulin release. Glutamate production is diminished in an incretin-unresponsive, insulin-secreting β cell line and pancreatic islets of animal models of human diabetes and obesity. Conversely, a membrane-permeable glutamate precursor restores amplification of insulin secretion in these models. Thus, cytosolic glutamate represents the elusive link between glucose metabolism and cAMP action in incretin-induced insulin secretion.

  8. CCL5 activation of CCR5 regulates cell metabolism to enhance proliferation of breast cancer cells.

    Science.gov (United States)

    Gao, Darrin; Rahbar, Ramtin; Fish, Eleanor N

    2016-06-01

    In earlier studies, we showed that CCL5 enhances proliferation and survival of MCF-7 breast cancer cells in an mTOR-dependent manner and we provided evidence that, for T cells, CCL5 activation of CCR5 results in increased glycolysis and enhanced ATP production. Increases in metabolic activity of cancer cells, specifically increased glycolytic activity and increased expression of glucose transporters, are associated with tumour progression. In this report, we provide evidence that CCL5 enhances the proliferation of human breast cancer cell lines (MDA-MB-231, MCF-7) and mouse mammary tumour cells (MMTV-PyMT), mediated by CCR5 activation. Concomitant with enhanced proliferation we show that CCL5 increases cell surface expression of the glucose transporter GLUT1, and increases glucose uptake and ATP production by these cells. Blocking CCL5-inducible glucose uptake abrogates the enhanced proliferation induced by CCL5. We provide evidence that increased glucose uptake is associated with enhanced glycolysis, as measured by extracellular acidification. Moreover, CCL5 enhances the invasive capacity of these breast cancer cells. Using metabolomics, we demonstrate that the metabolic signature of CCL5-treated primary mouse mammary tumour cells reflects increased anabolic metabolism. The implications are that CCL5-CCR5 interactions in the tumour microenvironment regulate metabolic events, specifically glycolysis, to promote tumour proliferation and invasion.

  9. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G. (NIDA Addiction Research Center, Baltimore, MD (USA))

    1990-12-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states.

  10. Designing a highly active soluble PQQ-glucose dehydrogenase for efficient glucose biosensors and biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Durand, Fabien [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France); Stines-Chaumeil, Claire [Universite de Bordeaux, CNRS, Institut de Biochimie et de Genetique Cellulaires, 1 rue Camille Saint Saens, 33077 Bordeaux Cedex (France); Flexer, Victoria [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France); Andre, Isabelle [Universite de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR5504, F-31400 Toulouse (France); INRA, UMR 792 Ingenierie des Systemes Biologiques et des Procedes, F-31400 Toulouse (France); Mano, Nicolas, E-mail: mano@crpp-bordeaux.cnrs.fr [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France)

    2010-11-26

    Research highlights: {yields} A new mutant of PQQ-GDH designed for glucose biosensors application. {yields} First mutant of PQQ-GDH with higher activity for D-glucose than the Wild type. {yields} Position N428 is a key point to increase the enzyme activity. {yields} Molecular modeling shows that the N428 C mutant displays a better interaction for PQQ than the WT. -- Abstract: We report for the first time a soluble PQQ-glucose dehydrogenase that is twice more active than the wild type for glucose oxidation and was obtained by combining site directed mutagenesis, modelling and steady-state kinetics. The observed enhancement is attributed to a better interaction between the cofactor and the enzyme leading to a better electron transfer. Electrochemical experiments also demonstrate the superiority of the new mutant for glucose oxidation and make it a promising enzyme for the development of high-performance glucose biosensors and biofuel cells.

  11. Effect of pioglitazone on glucose metabolism and luteinizing hormone secretion in women with polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Glintborg, Dorte; Hermann, Anne Pernille; Andersen, Marianne;

    2006-01-01

    OBJECTIVE: To thoroughly examine the mechanisms for insulin resistance in polycystic ovary syndrome (PCOS) and to evaluate the effects of pioglitazone treatment on insulin resistance, beta-cell function, LH secretion, and glucose metabolism. DESIGN: Randomized, blinded, placebo-controlled study....... SETTING: Outpatient clinic, at a university hospital in Denmark. PATIENT(S): Thirty obese women with PCOS and 14 weight-matched healthy females. INTERVENTION(S): Sixteen weeks of blinded treatment with pioglitazone (30 mg/d) or placebo. MAIN OUTCOME MEASURE(S): Fasting blood samples, 24-hour 20-minute...... of lipid oxidation. During 24-hour blood sampling, significantly lower area under-the-curve insulin and lower median insulin levels were observed. Secretion profiles of LH and E(2) and T levels did not change significantly. CONCLUSION(S): Insulin resistance in PCOS was characterized by hyperinsulinemia...

  12. Obstructive sleep apnea is associated with impaired glucose metabolism in Han Chinese subjects

    Institute of Scientific and Technical Information of China (English)

    GU Chen-juan; LI Min; LI Qing-yun; LI Ning; SHI Guo-chao; WAN Huan-ying

    2013-01-01

    Background Increasingly,evidence from population,clinic-based and laboratory studies supports an independent association between obstructive sleep apnea syndrome (OSAS) and an increased risk of type 2 diabetes; however,this observation has yet to be replicated in China and the potential mechanisms that link these two conditions are not clear.Methods A total of 179 Han Chinese subjects were enrolled in this study.All subjects underwent polysomnography,the oral glucose tolerance-insulin releasing test (OGTT-IRT) and serum HbA1c measurement.Indexes including homeostasis model assessment-IR (HOMA-IR),Matsuda index,HOMA-β,early phase insulinogenic index (△I30 / △G30),AUC-I180 and oral disposition index (DIo) were calculated for the assessment of insulin resistance and pancreatic β-cell function.Results Based on OGTT,25.4%,44.6% and 54.5% subjects were diagnosed having glucose metabolic disorders respectively in control,mild to moderate and severe OSAS groups (P <0.05).Serum HbA1c levels were highest in subjects with severe OSAS (P <0.05).In contrast,compared with normal subjects,HOMA-β,△I30/△G30 and DIo were lower in severe OSAS group (P <0.05).In stepwise multiple linear regressions,0-min glucose and HbA1c were positively correlated with the percentage of total sleep time below an oxyhemoglobin saturation of 90% (T90) (Beta =0.215 and 0.368,P <0.05); 30-min and 60-min glucose was negatively correlated with the lowest SpO2 (LSpO2) (Beta =-0.214 and -0.241,P <0.05).HOMA-β and Dlowere negatively correlated with T90 (Beta =-0.153 and-0.169,P <0.05) while body mass index (BMI) was the only determinant of HOMA-IR and Matsuda index.Conclusions OSAS is associated with impairment in glucose tolerance and pancreatic β-cell function in Han Chinese subjects while insulin sensitivity is mainly determined by obesity.

  13. Metabolism Is Central to Tolerogenic Dendritic Cell Function

    Directory of Open Access Journals (Sweden)

    Wen Jing Sim

    2016-01-01

    Full Text Available Immunological tolerance is a fundamental tenant of immune homeostasis and overall health. Self-tolerance is a critical component of the immune system that allows for the recognition of self, resulting in hyporeactivity instead of immunogenicity. Dendritic cells are central to the establishment of dominant immune tolerance through the secretion of immunosuppressive cytokines and regulatory polarization of T cells. Cellular metabolism holds the key to determining DC immunogenic or tolerogenic cell fate. Recent studies have demonstrated that dendritic cell maturation leads to a shift toward a glycolytic metabolic state and preferred use of glucose as a carbon source. In contrast, tolerogenic dendritic cells favor oxidative phosphorylation and fatty acid oxidation. This dichotomous metabolic reprogramming of dendritic cells drives differential cellular function and plays a role in pathologies, such as autoimmune disease. Pharmacological alterations in metabolism have promising therapeutic potential.

  14. Effects of glucose and insulin on the H9c2 (2-1) cell proliferation may be mediated through regulating glucose transporter 4 expression

    Institute of Scientific and Technical Information of China (English)

    LIU Qian; HUANG Qing-xian; LOU Fu-chen; ZHANG Li; WANG Kun; YU Shan; XU Hua

    2013-01-01

    Background The change of glucose transporter 4 (GLUT4) expression could influence glucose uptake in the myocardial cells and then effect myocardial metabolism,which maybe one of the factor for the diabetes cardiovascular disease.This study aimed to explore the influence of glucose and insulin at different concentrations on H9c2 (2-1) cell proliferation and its GLUT4 expression in vitro,and evaluate the correlation between myocardial cells proliferation and GLUT4 expression.This might be helpful for understanding the relationship between glucose metabolism and cardiovascular disease.Methods According to glucose concentrations in culture medium,cultured H9c2 rat myocardial cells were divided into five groups:control group (NC,glucose concentration 5.0 mmol/L),low glucose group (LG,glucose concentration 0.1 mmol/L),high glucose group 1 (HG1,glucose concentration 10 mmol/L),high glucose group 2 (HG2,glucose concentration 15 mmol/L),high glucose group 3 (HG3,glucose concentration 20 mmol/L).Then according to different insulin concentrations in culture medium,each group was further divided into two subgroups:normal insulin subgroup (INSc,insulin concentration 3.8 mU/L),high insulin subgroup (INSh,insulin concentration 7.6 mU/L).H9c2 (2-1) cells were cultured for 1,2,3 days,the proliferation of cells were assayed by cell counting Kit-8 assay,the expressions of GLUT4 mRNA and protein were detected with RT-PCR and Western Blotting technique,and the relation between myocardial cells proliferation and GLUT4 expression was evaluated.Results Compared with NC group,cell proliferation (OD value) was lower in LG,HG2,HG3 group but higher in HG1 group on the second and the third day (P <0.05).There was a negative correlation between OD value and the glucose level in HG1,HG2,HG3 groups (P <0.05).OD value in INSc subgroups was lower than that in INSh subgroups (P <0.05).GLUT4 mRNA was lower in LG,HG2,HG3 groups than that in NC group (P <0.05).Compared with NC group,GLUT4 m

  15. Inhibition of glucose turnover by 3-bromopyruvate counteracts pancreatic cancer stem cell features and sensitizes cells to gemcitabine

    OpenAIRE

    Isayev, Orkhan; Rausch, Vanessa; Bauer, Nathalie; Liu, Li; Fan, Pei; Zhang, Yiyao; Gladkich, Jury; Nwaeburu, Clifford C.; Mattern, Jürgen; Mollenhauer, Martin; Rückert, Felix; Zach, Sebastian; Haberkorn, Uwe; Gross, Wolfgang; Schönsiegel, Frank

    2014-01-01

    According to the cancer stem cell (CSC) hypothesis, the aggressive growth and early metastasis of pancreatic ductal adenocarcinoma (PDA) is due to the activity of CSCs, which are not targeted by current therapies. Otto Warburg suggested that the growth of cancer cells is driven by a high glucose metabolism. Here, we investigated whether glycolysis inhibition targets CSCs and thus may enhance therapeutic efficacy. Four established and 3 primary PDA cell lines, non-malignant cells, and 3 patien...

  16. Simultaneous utilization of glucose and gluconate in Penicillium chrysogenum during overflow metabolism.

    Science.gov (United States)

    Schmitz, Katja; Peter, Vivien; Meinert, Sabine; Kornfeld, Georg; Hardiman, Timo; Wiechert, Wolfgang; Noack, Stephan

    2013-12-01

    The filamentous fungus Penicillium chrysogenum is one of the most important production organism for β-lactam antibiotics, especially penicillin. A specific feature of P. chrysogenum is the formation of gluconate as the primary overflow metabolite under non-limiting growth on glucose. Gluconate can be formed extracellularly by the enzyme glucose oxidase (GOD) that shows high activities under glucose excess conditions. Currently, it is assumed that under these conditions glucose is the preferred carbon substrate for P. chrysogenum and gluconate consumption first starts after glucose becomes limiting. Here, we specifically address this hypothesis by combining batch cultivation experiments on defined glucose media, time-dependent GOD activity measurements, and (13)C-tracer studies. Our data prove that both substrates are metabolized simultaneously independent from the actual glucose concentration and therefore suggest that no distinct mechanism of carbon catabolite repression exists for gluconate in P. chrysogenum. Moreover, gluconate consumption does not interfere with penicillin V production by repression of the penicillin genes. Finally, by following a model-driven approach the specific uptake rates for glucose and gluconate were quantified and found to be significantly higher for gluconate. In summary, our results show that P. chrysogenum metabolizes gluconate directly and at high rates making it an interesting alternative carbon source for production purposes.

  17. Neuroendocrinology: Electromagnetogenetic Control over Feeding and Glucose Metabolism.

    Science.gov (United States)

    Ruud, Johan; Brüning, Jens C

    2016-06-06

    Cutting-edge experiments show a new means to control the activity of specifically genetically targeted neurons in the hypothalamus using electromagnetic force. At the flip of a switch, the system bidirectionally regulates feeding behavior and glucose homeostasis, demonstrating wireless control over deep brain regions and their strong influence over energy balance.

  18. The Alzheimer's Disease-Related Glucose Metabolic Brain Pattern

    NARCIS (Netherlands)

    Teune, Laura K.; Strijkert, Fijanne; Renken, Remco J.; Izaks, Gerbrand J.; de Vries, Jeroen J.; Segbers, Marcel; Roerdink, Jos B. T. M.; Dierckx, Rudi A. J. O.; Leenders, Klaus L.

    2014-01-01

    Purpose: [F-18] fluorodeoxyglucose (FDG) PET imaging of the brain can be used to assist in the differential diagnosis of dementia. Group differences in glucose uptake between patients with dementia and controls are well-known. However, a multivariate analysis technique called scaled subprofile model

  19. A quantitative proteomic analysis of cellular responses to high glucose media in Chinese hamster ovary cells.

    Science.gov (United States)

    Liu, Zhenke; Dai, Shujia; Bones, Jonathan; Ray, Somak; Cha, Sangwon; Karger, Barry L; Li, Jingyi Jessica; Wilson, Lee; Hinckle, Greg; Rossomando, Anthony

    2015-01-01

    A goal in recombinant protein production using Chinese hamster ovary (CHO) cells is to achieve both high specific productivity and high cell density. Addition of glucose to the culture media is necessary to maintain both cell growth and viability. We varied the glucose concentration in the media from 5 to 16 g/L and found that although specific productivity of CHO-DG44 cells increased with the glucose level, the integrated viable cell density decreased. To examine the biological basis of these results, we conducted a discovery proteomic study of CHO-DG44 cells grown under batch conditions in normal (5 g/L) or high (15 g/L) glucose over 3, 6, and 9 days. Approximately 5,000 proteins were confidently identified against an mRNA-based CHO-DG44 specific proteome database, with 2,800 proteins quantified with at least two peptides. A self-organizing map algorithm was used to deconvolute temporal expression profiles of quantitated proteins. Functional analysis of altered proteins suggested that differences in growth between the two glucose levels resulted from changes in crosstalk between glucose metabolism, recombinant protein expression, and cell death, providing an overall picture of the responses to high glucose environment. The high glucose environment may enhance recombinant dihydrofolate reductase in CHO cells by up-regulating NCK1 and down-regulating PRKRA, and may lower integrated viable cell density by activating mitochondrial- and endoplasmic reticulum-mediated cell death pathways by up-regulating HtrA2 and calpains. These proteins are suggested as potential targets for bioengineering to enhance recombinant protein production.

  20. Glucose metabolism in the antibiotic producing actinomycete Nonomuraea sp ATCC 39727

    DEFF Research Database (Denmark)

    Gunnarsson, Nina; Bruheim, Per; Nielsen, Jens

    2004-01-01

    primary carbon metabolism in further detail, Nonomuraea was cultivated with [1-C-13] glucose as the only carbon source and the C-13-labeling patterns of proteinogenic amino acids were determined by GC-MS analysis. Through this method, the fluxes in the central carbon metabolism during balanced growth were......The actinomycete Nonomuraea sp. ATCC 39727, producer of the glycopeptide A40926 that is used as precursor for the novel antibiotic dalbavancin, has an unusual carbon metabolism. Glucose is primarily metabolized via the Entner-Doudoroff (ED) pathway, although the energetically more favorable Embden...... - Meyerhof - Parnas (EMP) pathway is present in this organism. Moreover, Nonomuraea utilizes a PPi-dependent phosphofructokinase, an enzyme that has been connected with anaerobic metabolism in eukaryotes and higher plants, but recently has been recognized in several actinomycetes. In order to study its...

  1. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  2. Betatrophin and glucose-lipid metabolism%Betatrophin与糖脂代谢

    Institute of Scientific and Technical Information of China (English)

    赵术君; 王明明; 刘师伟

    2015-01-01

    Betatrophin是2013年发现的一种由肝脏、白色脂肪组织及褐色脂肪组织分泌的蛋白.其可以显著而特异性地促进胰岛β细胞增生及β细胞数量的增加,从而改善小鼠糖耐量.同时Betatrophin也参与脂代谢.Betatrophin可能成为治疗糖尿病及脂代谢疾病的新靶点.%Betatrophin,discovered in 2013,is a protein secreted by liver,white adipose tissues,and brown adipose tissues.Betatrophin can improve glucose tolerance in mice by promoting islet β cell proliferation and increasing the number of β cells significantly and specifically.At the same time,Betatrophin is involved in lipid metabolism.Betatrophin may work as the new target for treatment of diabetes and disorders of lipid metabolism.

  3. Sex-related differences in peripheral glucose metabolism in normal subjects.

    Science.gov (United States)

    Paula, F J; Pimenta, W P; Saad, M J; Paccola, G M; Piccinato, C E; Foss, M C

    1990-01-01

    The metabolic response of muscle tissue to glucose ingestion was studied in 10 normal men (M) and women (F) by using the forearm balance technique and indirect calorimetry simultaneously. During the 3 hours after a 75 g--oral glucose load, glucose uptake per unit muscle mass was significantly higher in women than in men, F = 187.3 +/- 26.9 vs M = 116.7 +/- 9.5 mg/100 g forearm muscle (P less than 0.05). A significant difference in muscle glucose fate was also observed since the amount of glucose utilized through a nonoxidative pathway was significantly higher in women, F = 84.5 +/- 2.6% (161.8 +/- 27.3 mg/100 g forearm muscle) vs M = 75.3 +/- 2.2% (87.2 +/- 8.6 mg/100 g forearm muscle) (P less than 0.05), whereas the amount of glucose oxidized in relation to glucose uptake was significantly higher in men, M = 24.7 +/- 2.2% (28.2 +/- 3.2 mg/100 g forearm muscle) vs F = 15.5 +/- 2.6% (27.8 +/- 5.4 mg/100 g forearm muscle) (P less than 0.05). No significant differences in insulin response to glucose ingestion were detected between groups. The women showed greater suppression of serum free fatty acids (FFA) levels in relation to basal levels than men. We conclude that: 1) after ingesting 75 g glucose, normal women showed greater glucose uptake per unit muscle mass than normal men, 2) for 3 hours after the ingestion of 75 g glucose, the predominant tendency toward utilizing glucose by a nonoxidative pathway is more marked in normal women than in normal men, and 3) the higher glucose uptake per unit muscle mass in the female group in the presence of an insulin response not significantly different from that of the male group suggests that muscle insulin sensitivity is greater in normal women.

  4. Effect of Antibiotics on Gut Microbiota, Gut Hormones and Glucose Metabolism

    DEFF Research Database (Denmark)

    Mikkelsen, Kristian H; Frost, Morten; Bahl, Martin Iain;

    2015-01-01

    The gut microbiota has been designated as an active regulator of glucose metabolism and metabolic phenotype in a number of animal and human observational studies. We evaluated the effect of removing as many bacteria as possible by antibiotics on postprandial physiology in healthy humans. Meal tests...... with measurements of postprandial glucose tolerance and postprandial release of insulin and gut hormones were performed before, immediately after and 6 weeks after a 4-day, broad-spectrum, per oral antibiotic cocktail (vancomycin 500 mg, gentamycin 40 mg and meropenem 500 mg once-daily) in a group of 12 lean...... and glucose tolerant males. Faecal samples were collected for culture-based assessment of changes in gut microbiota composition. Acute and dramatic reductions in the abundance of a representative set of gut bacteria was seen immediately following the antibiotic course, but no changes in postprandial glucose...

  5. Analysis of Patients With Coronary Heart Disease Combined With Impaired Glucose Metabolism

    Institute of Scientific and Technical Information of China (English)

    Zhi-ping GAO; Li-wen LIE; Ying-ling ZHOU; Hao-jian DONG

    2009-01-01

    Objectives To study the morbidity of patients with coronary artery disease (CAD) combined with impaired glucose metabolism. Methods Retrospective analysis of clinical data about patients with CAD in 1997, 2002 and 2007, sepa-rately. A total of 2951 patients were enrolled, among whom had coexistence of 457 abnormal glycometabolism, inclu-ding impaired fasting glucose, impaired glucose tolerance and type 2 diabetes mellitus. Results The prevalence of ab-normal glycometabolism in patients with CAD was increasing year by year. The morbidity raised from 3.8% and 16. 5% to 10. 8% in these three years. Contusion It is more and more common to detect CAD with impaired glucose metabolism, and it should be emphasized in the secondary prevention of CAD.

  6. Glucose metabolism, islet architecture, and genetic homogeneity in imprinting of [Ca2+](i and insulin rhythms in mouse islets.

    Directory of Open Access Journals (Sweden)

    Craig S Nunemaker

    Full Text Available We reported previously that islets isolated from individual, outbred Swiss-Webster mice displayed oscillations in intracellular calcium ([Ca2+](i that varied little between islets of a single mouse but considerably between mice, a phenomenon we termed "islet imprinting." We have now confirmed and extended these findings in several respects. First, imprinting occurs in both inbred (C57BL/6J as well as outbred mouse strains (Swiss-Webster; CD1. Second, imprinting was observed in NAD(PH oscillations, indicating a metabolic component. Further, short-term exposure to a glucose-free solution, which transiently silenced [Ca2+](i oscillations, reset the oscillatory patterns to a higher frequency. This suggests a key role for glucose metabolism in maintaining imprinting, as transiently suppressing the oscillations with diazoxide, a K(ATP-channel opener that blocks [Ca2+](i influx downstream of glucose metabolism, did not change the imprinted patterns. Third, imprinting was not as readily observed at the level of single beta cells, as the [Ca2+](i oscillations of single cells isolated from imprinted islets exhibited highly variable, and typically slower [Ca2+](i oscillations. Lastly, to test whether the imprinted [Ca2+](i patterns were of functional significance, a novel microchip platform was used to monitor insulin release from multiple islets in real time. Insulin release patterns correlated closely with [Ca2+](i oscillations and showed significant mouse-to-mouse differences, indicating imprinting. These results indicate that islet imprinting is a general feature of islets and is likely to be of physiological significance. While islet imprinting did not depend on the genetic background of the mice, glucose metabolism and intact islet architecture may be important for the imprinting phenomenon.

  7. Dibenzoylmethane exerts metabolic activity through regulation of AMP-activated protein kinase (AMPK-mediated glucose uptake and adipogenesis pathways.

    Directory of Open Access Journals (Sweden)

    Nami Kim

    Full Text Available Dibenzoylmethane (DBM has been shown to exert a variety of beneficial effects on human health. However, the mechanism of action is poorly understood. In this study, DBM increased phosphorylation of AMP-activated protein kinase (AMPK and stimulated glucose uptake in a skeletal muscle cell line. Both knockdown of AMPK with siRNA and inhibition with AMPK inhibitor blocked DBM-induced glucose uptake. DBM increased the concentration of intracellular calcium and glucose uptake due to DBM was abolished by STO-609 (a calcium/calmodulin-dependent protein kinase inhibitor. DBM stimulated phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK, which was blocked by pretreatment with compound C, an AMPK inhibitor. The expression of glucose transporter type 4 (GLUT4 was increased by DBM. The translocation of GLUT4 to the plasma membrane was also increased by DBM in AMPK dependently. In addition, DBM suppressed weight gain and prevented fat accumulation in the liver and abdomen in mice fed a high-fat diet. In pre-adipocyte cells, DBM decreased the activity of acetyl-CoA carboxylase (ACC, the rate-limiting enzyme of fatty acid synthesis. Expression of the adipogenic gene, fatty acid synthase (FAS, was suppressed by DBM in an AMPK-dependent manner. These results showed that the beneficial metabolic effects of DBM might be due to regulation of glucose uptake via AMPK in skeletal muscle and inhibition of adipogenesis in pre-adipocytes.

  8. Glucose metabolism in small subcortical structures in Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per; Hansen, Søren B; Eggers, Carsten;

    2012-01-01

    Evidence from experimental animal models of Parkinson's disease (PD) suggests a characteristic pattern of metabolic perturbation in discrete, very small basal ganglia structures. These structures are generally too small to allow valid investigation by conventional positron emission tomography (PET...

  9. Fructose Alters Intermediary Metabolism of Glucose in Human Adipocytes and Diverts Glucose to Serine Oxidation in the One–Carbon Cycle Energy Producing Pathway

    OpenAIRE

    Vijayalakshmi Varma; Boros, László G; Nolen, Greg T.; Ching-Wei Chang; Martin Wabitsch; Beger, Richard D.; Jim Kaput

    2015-01-01

    Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS) preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration. Targeted tracer [1,2-13C2]-d-glucose fate asso...

  10. Changes in metabolism during a fasting period and a subsequent vegetarian diet with particular reference to glucose metabolism.

    Science.gov (United States)

    Lithell, H; Vessby, B; Hellsing, K; Ljunghall, K; Höglund, N J; Werner, I; Bruce, A

    1983-01-01

    During an investigation on the effect of fasting and a vegetarian diet on the symptoms and signs in chronic cutaneous and arthritic diseases studies were made of glucose metabolism, liver function and the plasma concentration and urine excretion of some minerals. The study was performed on 27 patients who stayed as in-patients on a metabolic ward for five weeks. After the fasting period the blood glucose and serum insulin concentrations were lower (p less than 0.01) than before the fast. At the end of the period on the vegetarian (vegan) diet (three weeks) the insulin/glucose ratio was lower than at the start of the fast. Serum enzyme concentrations reflecting liver function increased during the fast, but normalized during the vegan diet. The intake of vitamin B12 and of selenium due to the vegan diets was very low, which may give reason for some concern during long-term use of this type of vegetarian diet.

  11. Complex Patterns of Metabolic and Ca2+ Entrainment in Pancreatic Islets by Oscillatory Glucose

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Mosekilde, Erik; Polonsky, Kenneth S.

    2013-01-01

    fluorescence microscopy to demonstrate that glucose oscillations can induce distinct 1:1 and 1:2 entrainment of oscillations (one and two oscillations for each period of exogenous stimulus, respectively) in islet Ca2+ , NAD(P)H, and mitochondrial membrane potential. To our knowledge, this is the first......Glucose-stimulated insulin secretion is pulsatile and driven by intrinsic oscillations in metabolism, electrical activity, and Ca2+in pancreatic islets. Periodic variations in glucose can entrain islet Ca2+ and insulin secretion, possibly promoting interislet synchronization. Here, we used...... demonstration of metabolic entrainment in islets, and we found that entrainment of metabolic oscillations requires voltage-gated Ca2+ influx. We identified diverse patterns of 1:2 entrainment and showed that islet synchronization during entrainment involves adjustments of both oscillatory phase and period. All...

  12. Carbon Metabolism of Soil microorganisms at Low Temperatures: Position-Specific 13C Labeled Glucose Reveals the Story

    Science.gov (United States)

    Apostel, C.; Bore, E. K.; Halicki, S.; Kuzyakov, Y.; Dippold, M.

    2015-12-01

    Metabolic pathway activities at low temperature are not well understood, despite the fact that the processes are relevant for many soils globally and seasonally. To analyze soil metabolism at low temperature, isotopomeres of position-specifically 13C labeled glucose were applied at three temperature levels; +5, -5 -20 oC. In additon, one sterilization treatment with sodium azide at +5 oC was also performed. Soils were incubated for 1, 3 and 10 days while soil samples at -20 oC were additionally sampled after 30 days. The 13C from individual molecule position in respired CO2 was quantifed. Incorporation of 13C in bulk soil, extractable microbial biomass by chloroform fumigation extraction (CFE) and cell membranes of different microbial communities classified by 13C phospholipid fatty acid analysis (PLFA) was carried out. Our 13CO2 data showed a dominance of C-1 respiration at +5 °C for treatments with and without sodium azide, but total respiration for sodium azide inhibited treatments increased by 14%. In contrast, at -5 and -20 oC metabolic behavior showed intermingling of preferential respiration of the glucose C-4 and C-1 positions. Therefore, at +5 °C, pentose phosphate pathway activity is a dominant metabolic pathway used by microorganisms to metabolize glucose. The respiration increase due to NaN3 inhibition was attributed to endoenzymes released from dead organisms that are stabilized at the soil matrix and have access to suitable substrate and co-factors to permit their funtions. Our PLFA analysis showed that incorporation of glucose 13C was higher in Gram negative bacteria than other microbial groups as they are most competitive for LMWOS. Only a limited amount of microbial groups maintained their glucose utilizing activity at -5 and -20 °C and they strongly shifted towards a metabolization of glucose via both glycolysis and pentose phosphate pathways indicating both growth and cellular maintenance. This study revealed a remarkable microbial acitivity

  13. Ketones and brain development: Implications for correcting deteriorating brain glucose metabolism during aging

    Directory of Open Access Journals (Sweden)

    Nugent Scott

    2016-01-01

    Full Text Available Brain energy metabolism in Alzheimer’s disease (AD is characterized mainly by temporo-parietal glucose hypometabolism. This pattern has been widely viewed as a consequence of the disease, i.e. deteriorating neuronal function leading to lower demand for glucose. This review will address deteriorating glucose metabolism as a problem specific to glucose and one that precedes AD. Hence, ketones and medium chain fatty acids (MCFA could be an alternative source of energy for the aging brain that could compensate for low brain glucose uptake. MCFA in the form of dietary medium chain triglycerides (MCT have a long history in clinical nutrition and are widely regarded as safe by government regulatory agencies. The importance of ketones in meeting the high energy and anabolic requirements of the infant brain suggest they may be able to contribute in the same way in the aging brain. Clinical studies suggest that ketogenesis from MCT may be able to bypass the increasing risk of insufficient glucose uptake or metabolism in the aging brain sufficiently to have positive effects on cognition.

  14. Glucose metabolism during fasting is altered in experimental porphobilinogen deaminase deficiency.

    Science.gov (United States)

    Collantes, María; Serrano-Mendioroz, Irantzu; Benito, Marina; Molinet-Dronda, Francisco; Delgado, Mercedes; Vinaixa, María; Sampedro, Ana; Enríquez de Salamanca, Rafael; Prieto, Elena; Pozo, Miguel A; Peñuelas, Iván; Corrales, Fernando J; Barajas, Miguel; Fontanellas, Antonio

    2016-04-01

    Porphobilinogen deaminase (PBGD) haploinsufficiency (acute intermittent porphyria, AIP) is characterized by neurovisceral attacks when hepatic heme synthesis is activated by endogenous or environmental factors including fasting. While the molecular mechanisms underlying the nutritional regulation of hepatic heme synthesis have been described, glucose homeostasis during fasting is poorly understood in porphyria. Our study aimed to analyse glucose homeostasis and hepatic carbohydrate metabolism during fasting in PBGD-deficient mice. To determine the contribution of hepatic PBGD deficiency to carbohydrate metabolism, AIP mice injected with a PBGD-liver gene delivery vector were included. After a 14 h fasting period, serum and liver metabolomics analyses showed that wild-type mice stimulated hepatic glycogen degradation to maintain glucose homeostasis while AIP livers activated gluconeogenesis and ketogenesis due to their inability to use stored glycogen. The serum of fasted AIP mice showed increased concentrations of insulin and reduced glucagon levels. Specific over-expression of the PBGD protein in the liver tended to normalize circulating insulin and glucagon levels, stimulated hepatic glycogen catabolism and blocked ketone body production. Reduced glucose uptake was observed in the primary somatosensorial brain cortex of fasted AIP mice, which could be reversed by PBGD-liver gene delivery. In conclusion, AIP mice showed a different response to fasting as measured by altered carbohydrate metabolism in the liver and modified glucose consumption in the brain cortex. Glucose homeostasis in fasted AIP mice was efficiently normalized after restoration of PBGD gene expression in the liver.

  15. Perinatal exposure to perfluorooctane sulfonate affects glucose metabolism in adult offspring.

    Directory of Open Access Journals (Sweden)

    Hin T Wan

    Full Text Available Perfluoroalkyl acids (PFAAs are globally present in the environment and are widely distributed in human populations and wildlife. The chemicals are ubiquitous in human body fluids and have a long serum elimination half-life. The notorious member of PFAAs, perfluorooctane sulfonate (PFOS is prioritized as a global concerning chemical at the Stockholm Convention in 2009, due to its harmful effects in mammals and aquatic organisms. PFOS is known to affect lipid metabolism in adults and was found to be able to cross human placenta. However the effects of in utero exposure to the susceptibility of metabolic disorders in offspring have not yet been elucidated. In this study, pregnant CD-1 mice (F0 were fed with 0, 0.3 or 3 mg PFOS/kg body weight/day in corn oil by oral gavage daily throughout gestational and lactation periods. We investigated the immediate effects of perinatal exposure to PFOS on glucose metabolism in both maternal and offspring after weaning (PND 21. To determine if the perinatal exposure predisposes the risk for metabolic disorder to the offspring, weaned animals without further PFOS exposure, were fed with either standard or high-fat diet until PND 63. Fasting glucose and insulin levels were measured while HOMA-IR index and glucose AUCs were reported. Our data illustrated the first time the effects of the environmental equivalent dose of PFOS exposure on the disturbance of glucose metabolism in F1 pups and F1 adults at PND 21 and 63, respectively. Although the biological effects of PFOS on the elevated levels of fasting serum glucose and insulin levels were observed in both pups and adults of F1, the phenotypes of insulin resistance and glucose intolerance were only evident in the F1 adults. The effects were exacerbated under HFD, highlighting the synergistic action at postnatal growth on the development of metabolic disorders.

  16. Glucose-deprivation increases thyroid cancer cells sensitivity to metformin.

    Science.gov (United States)

    Bikas, Athanasios; Jensen, Kirk; Patel, Aneeta; Costello, John; McDaniel, Dennis; Klubo-Gwiezdzinska, Joanna; Larin, Olexander; Hoperia, Victoria; Burman, Kenneth D; Boyle, Lisa; Wartofsky, Leonard; Vasko, Vasyl

    2015-12-01

    Metformin inhibits thyroid cancer cell growth. We sought to determine if variable glucose concentrations in medium alter the anti-cancer efficacy of metformin. Thyroid cancer cells (FTC133 and BCPAP) were cultured in high-glucose (20 mM) and low-glucose (5 mM) medium before treatment with metformin. Cell viability and apoptosis assays were performed. Expression of glycolytic genes was examined by real-time PCR, western blot, and immunostaining. Metformin inhibited cellular proliferation in high-glucose medium and induced cell death in low-glucose medium. In low-, but not in high-glucose medium, metformin induced endoplasmic reticulum stress, autophagy, and oncosis. At micromolar concentrations, metformin induced phosphorylation of AMP-activated protein kinase and blocked p-pS6 in low-glucose medium. Metformin increased the rate of glucose consumption from the medium and prompted medium acidification. Medium supplementation with glucose reversed metformin-inducible morphological changes. Treatment with an inhibitor of glycolysis (2-deoxy-d-glucose (2-DG)) increased thyroid cancer cell sensitivity to metformin. The combination of 2-DG with metformin led to cell death. Thyroid cancer cell lines were characterized by over-expression of glycolytic genes, and metformin decreased the protein level of pyruvate kinase muscle 2 (PKM2). PKM2 expression was detected in recurrent thyroid cancer tissue samples. In conclusion, we have demonstrated that the glucose concentration in the cellular milieu is a factor modulating metformin's anti-cancer activity. These data suggest that the combination of metformin with inhibitors of glycolysis could represent a new strategy for the treatment of thyroid cancer.

  17. The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome.

    Science.gov (United States)

    Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique; Cassis, Lisa A

    2012-03-15

    The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment.

  18. Disturbed postprandial glucose metabolism and gut hormone responses in non-diabetic patients with psoriasis

    DEFF Research Database (Denmark)

    Gyldenløve, M; Vilsbøll, T; Holst, Jens Juul

    2016-01-01

    Patients with psoriasis have increased risk of developing type 2 diabetes.(1-4) Though the aetiology is not fully understood, overrepresentation of traditional diabetes risk factors, shared genetics, and chronic inflammation likely explain some of the increased susceptibility. Glucose metabolism...... in patients with psoriasis has only been sparsely investigated. Previous studies are based on fasting blood samples analysed for glucose and insulin or various forms of glucose and/or insulin challenges.(5-11) The results are generally difficult to compare due to methodological differences and limitations...

  19. Elucidating the role of copper in CHO cell energy metabolism using (13)C metabolic flux analysis.

    Science.gov (United States)

    Nargund, Shilpa; Qiu, Jinshu; Goudar, Chetan T

    2015-01-01

    (13)C-metabolic flux analysis was used to understand copper deficiency-related restructuring of energy metabolism, which leads to excessive lactate production in recombinant protein-producing CHO cells. Stationary-phase labeling experiments with U-(13)C glucose were conducted on CHO cells grown under high and limiting copper in 3 L fed-batch bioreactors. The resultant labeling patterns of soluble metabolites were measured by GC-MS and used to estimate metabolic fluxes in the central carbon metabolism pathways using OpenFlux. Fluxes were evaluated 300 times from stoichiometrically feasible random guess values and their confidence intervals calculated by Monte Carlo simulations. Results from metabolic flux analysis exhibited significant carbon redistribution throughout the metabolic network in cells under Cu deficiency. Specifically, glycolytic fluxes increased (25%-79% relative to glucose uptake) whereas fluxes through the TCA and pentose phosphate pathway (PPP) were lower (15%-23% and 74%, respectively) compared with the Cu-containing condition. Furthermore, under Cu deficiency, 33% of the flux entering TCA via the pyruvate node was redirected to lactate and malate production. Based on these results, we hypothesize that Cu deficiency disrupts the electron transport chain causing ATP deficiency, redox imbalance, and oxidative stress, which in turn drive copper-deficient CHO cells to produce energy via aerobic glycolysis, which is associated with excessive lactate production, rather than the more efficient route of oxidative phosphorylation.

  20. Aldolase B knockdown prevents high glucose-induced methylglyoxal overproduction and cellular dysfunction in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Jianghai Liu

    Full Text Available We used cultured endothelial cells as a model to examine whether up-regulation of aldolase B and enhanced methylglyoxal (MG formation play an important role in high glucose-induced overproduction of advanced glycosylation endproducts (AGEs, oxidative stress and cellular dysfunction. High glucose (25 mM incubation up-regulated mRNA levels of aldose reductase (an enzyme converting glucose to fructose and aldolase B (a key enzyme that catalyzes MG formation from fructose and enhanced MG formation in human umbilical vein endothelial cells (HUVECs and HUVEC-derived EA. hy926 cells. High glucose-increased MG production in EA. hy926 cells was completely prevented by siRNA knockdown of aldolase B, but unaffected by siRNA knockdown of aldolase A, an enzyme responsible for MG formation during glycolysis. In addition, inhibition of cytochrome P450 2E1 or semicarbazide-sensitive amine oxidase which produces MG during the metabolism of lipid and proteins, respectively, did not alter MG production. Both high glucose (25 mM and MG (30, 100 µM increased the formation of N(ε-carboxyethyl-lysine (CEL, a MG-induced AGE, oxidative stress (determined by the generation of oxidized DCF, H(2O(2, protein carbonyls and 8-oxo-dG, O-GlcNAc modification (product of the hexosamine pathway, membrane protein kinase C activity and nuclear translocation of NF-κB in EA. hy926 cells. However, the above metabolic and signaling alterations induced by high glucose were completely prevented by knockdown of aldolase B and partially by application of aminoguanidine (a MG scavenger or alagebrium (an AGEs breaker. In conclusion, efficient inhibition of aldolase B can prevent high glucose-induced overproduction of MG and related cellular dysfunction in endothelial cells.

  1. Effect of Systemic Inflammation on the Function of Insulin and Glucose Metabolism in Rheumatoid Arthritis.

    Science.gov (United States)

    Herlitz-Cifuentes, Herbert Sebastian; Garces, Paulina Carola Fernandez; Fernandez, Liliana Ivone Lamperti; Guzman-Gutierrez, Enrique Alberto

    2015-01-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease of unknown etiology characterized by chronic inflammation of the synovial membranes and articular structures of the joints. The concomitant comorbidities are important in the management and treatment of patients with RA, because they decrease their life quality and expectancy - with cardiovascular diseases being the most common comorbidities and primary cause of death in RA. Traditional cardiovascular risk factors, such as diabetes mellitus (DM) and insulin resistance (IR) are prevalent in these patients. The prevalence of DM in RA patients has not been well established and the association between these diseases is controversial. On the other hand, several epidemiological studies support the association between RA and IR, with the latter being linked to systemic inflammatory markers, including C reactive protein and erythrocyte sedimentation rate. Patients with RA who underwent glucocorticoid therapy were also determined to have a defective insulin sensitivity and pancreatic β-cell dysfunction. It has been proposed that systemic inflammation due to RA may result in insulin resistance - moreover, studies have examined the effect of inflammatory cytokines such as TNF-α, IL-6 and IL-1 on insulin sensitivity and glucose metabolism. Likewise, the association between RA and IR, and its role on the different characteristics of the disease, such as duration, activity, and treatment with glucocorticoids has not been well defined. A gap in the current understanding regarding the role that the systemic inflammation and the different RA characteristics have on the insulin function and glucose metabolism of RA patients suggest that more studies are required to elucidate these mechanisms.

  2. Cerebral glucose metabolism in neurofibromatosis type 1 assessed with [18F]-2-fluoro-2-deoxy-D-glucose and PET.

    Science.gov (United States)

    Balestri, P; Lucignani, G; Fois, A; Magliani, L; Calistri, L; Grana, C; Di Bartolo, R M; Perani, D; Fazio, F

    1994-01-01

    Cerebral PET with [18F]-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This finding suggests that the abnormalities seen on MRI are not due to defective blood supply, localised oedema, or grey matter heterotopic foci as previously hypothesised. The presence of the hypometabolic areas seems to be inconsistently related to the occurrence of seizures and is not proportional to the degree of mental impairment. This study provides evidence of a widespread cerebral hypometabolism that is not related to the presence of MRI abnormalities; conversely normal metabolism was present in the areas with an abnormal MRI signal. Images PMID:7798976

  3. The effect of PCSK1 variants on waist, waist-hip ratio and glucose metabolism is modified by sex and glucose tolerance status

    DEFF Research Database (Denmark)

    Gjesing, Anette P; Vestmar, Marie A; Jørgensen, Torben;

    2011-01-01

    Background: We aimed to evaluate the effects of the G-allele of rs6232 and the C-allele of rs6235 within PCSK1 on measures of body fat and glucose homeostasis in Danish individuals and to assess interactions of genotypes with age, sex and glucose tolerance status. Data were included in meta-analy...... composition which may be modified by sex, whereas the effect of rs6235 C-allele on fasting and stimulated circulating plasma glucose and hormone levels may be influenced by glucose tolerance status.......-allele was associated nominally with a 0.6% (0.1–1%, p = 0.01) reduction in fasting glucose, it interacted with glucose tolerance status for traits related to glucose metabolism and analysis among individuals having abnormal glucose tolerance revealed a 5% (20.7–9%, p = 0.02) elevated level of acute insulin response...

  4. Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis

    Directory of Open Access Journals (Sweden)

    Logullo Carlos

    2010-02-01

    Full Text Available Abstract Background The mosquito A. aegypti is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of A. aegypty life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during A. aegypti embryogenesis are unknown. Results Glucose metabolism was investigated throughout Aedes aegypti (Diptera embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE and germ band retraction (GBr, 24 HAE may be considered landmarks regarding glucose 6-phosphate (G6P destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP, of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK and pyruvate kinase (PK activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3 activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis. Conclusions The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose

  5. Glucose metabolism via the pentose phosphate pathway, glycolysis and Krebs cycle in an orthotopic mouse model of human brain tumors.

    Science.gov (United States)

    Marin-Valencia, Isaac; Cho, Steve K; Rakheja, Dinesh; Hatanpaa, Kimmo J; Kapur, Payal; Mashimo, Tomoyuki; Jindal, Ashish; Vemireddy, Vamsidhara; Good, Levi B; Raisanen, Jack; Sun, Xiankai; Mickey, Bruce; Choi, Changho; Takahashi, Masaya; Togao, Osamu; Pascual, Juan M; Deberardinis, Ralph J; Maher, Elizabeth A; Malloy, Craig R; Bachoo, Robert M

    2012-10-01

    It has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using orthotopic mouse models of human glioblastoma (GBM) and renal cell carcinoma metastatic to brain, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-(13) C(2) ]glucose. The [3-(13) C]lactate/[2,3-(13) C(2) ]lactate ratio was similar for both the GBM and brain metastasis and their respective surrounding brains (GBM, 0.197 ± 0.011 and 0.195 ± 0.033, respectively (p = 1); metastasis: 0.126 and 0.119 ± 0.033, respectively). This suggests that the rate of glycolysis is significantly greater than the PPP flux in these tumors, and that the PPP flux into the lactate pool is similar in both tumors. Remarkably, (13) C-(13) C coupling was observed in molecules derived from Krebs cycle intermediates in both tumor types, denoting glucose oxidation. In the renal cell carcinoma, in contrast with GBM, (13) C multiplets of γ-aminobutyric acid (GABA) differed from its precursor glutamate, suggesting that GABA did not derive from a common glutamate precursor pool. In addition, the orthotopic renal tumor, the patient's primary renal mass and brain metastasis were all strongly immunopositive for the 67-kDa isoform of glutamate decarboxylase, as were 84% of tumors on a renal cell carcinoma tissue microarray of the same histology, suggesting that GABA synthesis is cell autonomous in at least a subset of renal cell carcinomas. Taken together, these data demonstrate that (13) C-labeled glucose can be used in orthotopic mouse models to study tumor metabolism in vivo and to ascertain new metabolic targets for cancer diagnosis and therapy.

  6. Role of hypoxia in obesity-induced disorders of glucose and lipid metabolism in adipose tissue

    Science.gov (United States)

    Yin, Jun; Gao, Zhanguo; He, Qing; Zhou, Dequan; Guo, ZengKui; Ye, Jianping

    2009-01-01

    Recent studies suggest that adipose tissue hypoxia (ATH) may contribute to endocrine dysfunction in adipose tissue of obese mice. In this study, we examined hypoxia's effects on metabolism in adipocytes. We determined the dynamic relationship of ATH and adiposity in ob/ob mice. The interstitial oxygen pressure (Po2) was monitored in the epididymal fat pads for ATH. During weight gain from 39.5 to 55.5 g, Po2 declined from 34.8 to 20.1 mmHg, which are 40–60% lower than those in the lean mice. Insulin receptor-β (IRβ) and insulin receptor substrate-1 (IRS-1) were decreased in the adipose tissue of obese mice, and the alteration was observed in 3T3-L1 adipocytes after hypoxia (1% oxygen) treatment. Insulin-induced glucose uptake and Akt Ser473 phosphorylation was blocked by hypoxia in the adipocytes. This effect of hypoxia exhibited cell type specificity, as it was not observed in L6 myotubes and βTC6 cells. In response to hypoxia, free fatty acid (FFA) uptake was reduced and lipolysis was increased in 3T3-L1 adipocytes. The molecular mechanism of decreased fatty acid uptake may be related to inhibition of fatty acid transporters (FATP1 and CD36) and transcription factors (PPARγ and C/EBPα) by hypoxia. The hypoxia-induced lipolysis was observed in vivo after femoral arterial clamp. Necrosis and apoptosis were induced by hypoxia in 3T3-L1 adipocytes. These data suggest that ATH may promote FFA release and inhibit glucose uptake in adipocytes by inhibition of the insulin-signaling pathway and induction of cell death. PMID:19066318

  7. Quantification of Metabolic Rearrangements During Neural Stem Cells Differentiation into Astrocytes by Metabolic Flux Analysis.

    Science.gov (United States)

    Sá, João V; Kleiderman, Susanne; Brito, Catarina; Sonnewald, Ursula; Leist, Marcel; Teixeira, Ana P; Alves, Paula M

    2017-01-01

    Proliferation and differentiation of neural stem cells (NSCs) have a crucial role to ensure neurogenesis and gliogenesis in the mammalian brain throughout life. As there is growing evidence for the significance of metabolism in regulating cell fate, knowledge on the metabolic programs in NSCs and how they evolve during differentiation into somatic cells may provide novel therapeutic approaches to address brain diseases. In this work, we applied a quantitative analysis to assess how the central carbon metabolism evolves upon differentiation of NSCs into astrocytes. Murine embryonic stem cell (mESC)-derived NSCs and astrocytes were incubated with labelled [1-(13)C]glucose and the label incorporation into intracellular metabolites was followed by GC-MS. The obtained (13)C labelling patterns, together with uptake/secretion rates determined from supernatant analysis, were integrated into an isotopic non-stationary metabolic flux analysis ((13)C-MFA) model to estimate intracellular flux maps. Significant metabolic differences between NSCs and astrocytes were identified, with a general downregulation of central carbon metabolism during astrocytic differentiation. While glucose uptake was 1.7-fold higher in NSCs (on a per cell basis), a high lactate-secreting phenotype was common to both cell types. Furthermore, NSCs consumed glutamine from the medium; the highly active reductive carboxylation of alpha-ketoglutarate indicates that this was converted to citrate and used for biosynthetic purposes. In astrocytes, pyruvate entered the TCA cycle mostly through pyruvate carboxylase (81%). This pathway supported glutamine and citrate secretion, recapitulating well described metabolic features of these cells in vivo. Overall, this fluxomics study allowed us to quantify the metabolic rewiring accompanying astrocytic lineage specification from NSCs.

  8. Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics.

    Science.gov (United States)

    Geurts, L; Neyrinck, A M; Delzenne, N M; Knauf, C; Cani, P D

    2014-03-01

    Crosstalk between organs is crucial for controlling numerous homeostatic systems (e.g. energy balance, glucose metabolism and immunity). Several pathological conditions, such as obesity and type 2 diabetes, are characterised by a loss of or excessive inter-organ communication that contributes to the development of disease. Recently, we and others have identified several mechanisms linking the gut microbiota with the development of obesity and associated disorders (e.g. insulin resistance, type 2 diabetes, hepatic steatosis). Among these, we described the concept of metabolic endotoxaemia (increase in plasma lipopolysaccharide levels) as one of the triggering factors leading to the development of metabolic inflammation and insulin resistance. Growing evidence suggests that gut microbes contribute to the onset of low-grade inflammation characterising these metabolic disorders via mechanisms associated with gut barrier dysfunctions. We have demonstrated that enteroendocrine cells (producing glucagon-like peptide-1, peptide YY and glucagon-like peptide-2) and the endocannabinoid system control gut permeability and metabolic endotoxaemia. Recently, we hypothesised that specific metabolic dysregulations occurring at the level of numerous organs (e.g. gut, adipose tissue, muscles, liver and brain) rely from gut microbiota modifications. In this review, we discuss the mechanisms linking gut permeability, adipose tissue metabolism, and glucose homeostasis, and recent findings that show interactions between the gut microbiota, the endocannabinoid system and the apelinergic system. These specific systems are discussed in the context of the gut-to-peripheral organ axis (intestine, adipose tissue and brain) and impacts on metabolic regulation. In the present review, we also briefly describe the impact of a variety of non-digestible nutrients (i.e. inulin-type fructans, arabinoxylans, chitin glucans and polyphenols). Their effects on the composition of the gut microbiota and

  9. The Roots of Atractylodes macrocephala Koidzumi Enhanced Glucose and Lipid Metabolism in C2C12 Myotubes via Mitochondrial Regulation

    Directory of Open Access Journals (Sweden)

    Mi Young Song

    2015-01-01

    Full Text Available The root of Atractylodes macrocephala Koidzumi (Atractylodis Rhizoma Alba, ARA is a Traditional Korean Medicine and has been commonly used for weight control. Mitochondrial dysfunction appears to be a key contributor to insulin resistance, and therefore mitochondrial targeting drugs represent an important potential strategy for the treatment of insulin resistance and obesity. In this study, the authors investigated the regulatory effects of ARA on mitochondrial function with respect to the stimulation of glucose and lipid metabolism in C2C12 myotubes. After differentiating C2C12 myotubes, cells were treated with or without different concentrations (0.2, 0.5, and 1.0 mg/mL of ARA extract. ARA extract significantly increased the expression of peroxisome proliferator-activated receptor coactivator 1 alpha (PGC1α and the downregulations of its targets, nuclear respiratory factor-1 (NRF-1, transcription factor A (TFAM, and total ATP content in C2C12 myotubes. ARA extract also increased the expressions of PGC1α activator and of the metabolic sensors, AMP-activated protein kinase (AMPK, and acetyl-CoA carboxylase and sirtuin (SIRT 1. Furthermore, it significantly increased glucose uptake by enhancing glucose consumption and subsequently decreased FFA contents and increased carnitine palmitoyltransferase (CPT 1b expression. Our study indicates that ARA has a potential for stimulating mitochondrial function and energy metabolism in muscle.

  10. Metabolic network analysis of Bacillus clausii on minimal and semirich medium using C-13-Labeled glucose

    DEFF Research Database (Denmark)

    Christiansen, Torben; Christensen, Bjarke; Nielsen, Jens

    2002-01-01

    from the medium and partly synthesized from glucose. The metabolic network analysis was extended to include analysis of growth on the semirich medium containing amino acids, and the metabolic flux distribution on this medium was estimated and compared with growth on minimal medium....... to increase with increasing specific growth rate but at a much lower level than previously reported for Bacillus subtilis. Two futile cycles in the pyruvate metabolism were included in the metabolic network. A substantial flux in the futile cycle involving malic enzyme was estimated, whereas only a very small......Using C-13-labeled glucose fed to the facultative alkalophilic Bacillus clausii producing the alkaline serine protease Savinase, the intracellular fluxes were quantified in continuous cultivation and in batch cultivation on a minimal medium. The flux through the pentose phosphate pathway was found...

  11. The Lin28/let-7 Axis Regulates Glucose Metabolism

    NARCIS (Netherlands)

    Zhu, Hao; Shyh-Chang, Ng; Segre, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G.; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

    2011-01-01

    The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating-metabolism. When overexpressed in mice, both Lin28

  12. The characteristics of cortical glucose metabolism in amblyopia

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Ji Young [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of); Lee, Dong Soo; Chung, June Key; Shin, Seung Ai; Lee, Myung Chul [College of Medicine, Ewha Womans Univ., Seoul (Korea, Republic of)

    2000-07-01

    Cortical metabolism of amblyopia patients was investigated with F-18-FDG PET and Statistical Parametric Mapping (SPM) and quantificiation based on volume of interest (VOI) by statistical probabilistic anatomical map (SPAM). In 9 amblyopic patients (12{+-}7 years ) and 20 normal subjects (23{+-}2 years), F-18-FDG PET scans were peformed in amblyopic patients after amblyopic eye or sound eye was patch-closed during PET studies. SPM was done with SPM96. By multiplying SPAM to FDG images, counts of 98 VOI's were calculated and compared with 3 S. D. range of those of normal subjects. On SPM, cortical metabolism decreased (p<0.05) in occipital lobe (Ba 17, 18, 19), superior partietal lobe (Ba 7), and inferior temporal lobe (BA 37, 20). FDG uptake of gyri of occuipital lobe was decreased in 2 and increased in 2, and was normal in the other 5. FDG uptake of gyri of parietal, frontal, and temporal lobes were decreased in FDG uptake on these VOIs. We conclude that cortical metabolism in occipital lobe and extraoccipital lobes was variable but was consistent regardless of visual input during PET studies in amblyopic patients. SPM and quantification of functional images using SPAM could reveal subtle differences or changes according to visual input. The significance of metabolic changes of extraoccipital lobes should be studies further.

  13. Effect of cytochalasin B on 3-O-[(14)C]-methyl-D-glucose or D-[U-(14)C]glucose handling by BRIN-BD11 cells.

    Science.gov (United States)

    Cetik, Sibel; Rzajeva, Aigun; Malaisse, Willy J; Sener, Abdullah

    2014-07-01

    The present study aimed to investigate the effects of cytochalasin B (20 μM) on the uptake of 3-O-[(14)C]-methyl-D-glucose or D-[U-(14)C]glucose (8.3 mM each) by BRIN-BD11 cells. Taking into account the distribution space of tritiated water ((3)HOH), which was unexpectedly increased shortly after exposure of the cells to cytochalasin B and then progressively returned to its control values, and that of L-[1-(14)C]glucose, used as an extracellular marker, it was demonstrated that cytochalasin B caused a modest, but significant inhibition of the uptake of D-glucose and its non-metabolized analog by the BRIN-BD11 cells. These findings resemble those observed in acinar or ductal cells of the rat submaxillary gland and displayed a relative magnitude comparable to that found for the inhibition of D-glucose metabolism by cytochalasin B in purified pancreatic islet B cells. These findings reinforce the view that the primary site of action of cytochalasin B is located at the level of the plasma membrane.

  14. Sexual Dimorphism in Glucose and Lipid Metabolism during Fasting, Hypoglycemia, and Exercise

    OpenAIRE

    Hedrington, Maka S.; Davis, Stephen N.

    2015-01-01

    Sexually dimorphic physiologic responses occur during fasting, hypoglycemia, and exercise. The areas covered in this mini review include studies that have used isotopic tracer methods and/or euglycemic clamp studies to investigate substrate metabolism during the above common physiologic stress. Women have greater reliance on lipid metabolism during fasting, hypoglycemia, and exercise while men exhibit preference of carbohydrate utilization. Plasma glucose concentrations were shown to be lower...

  15. TAp63 is a master transcriptional regulator of lipid and glucose metabolism

    OpenAIRE

    Su, Xiaohua; Gi, Young Jin; Chakravarti, Deepavali; Chan, Io Long; Zhang, Aijun; Xia, Xuefeng; Tsai, Kenneth Y.; Flores, Elsa R.

    2012-01-01

    TAp63 prevents premature aging suggesting a link to genes that regulate longevity. Further characterization of TAp63−/− mice revealed that these mice develop obesity, insulin resistance, and glucose intolerance, similar to those seen in mice lacking two key metabolic regulators, Silent information regulator T1 (Sirt1) and AMPK. While the roles of Sirt1 and AMPK in metabolism have been well studied, their upstream regulators are not well understood. We found that TAp63 is important in regulati...

  16. Increased T cell glucose uptake reflects acute rejection in lung grafts

    Science.gov (United States)

    Chen, Delphine L.; Wang, Xingan; Yamamoto, Sumiharu; Carpenter, Danielle; Engle, Jacquelyn T.; Li, Wenjun; Lin, Xue; Kreisel, Daniel; Krupnick, Alexander S.; Huang, Howard J.; Gelman, Andrew E.

    2013-01-01

    Although T cells are required for acute lung rejection, other graft-infiltrating cells such as neutrophils accumulate in allografts and are also high glucose utilizers. Positron emission tomography (PET) with the glucose probe [18F]fluorodeoxyglucose ([18F]FDG) has been employed to image solid organ acute rejection, but the sources of glucose utilization remain undefined. Using a mouse model of orthotopic lung transplantation, we analyzed glucose probe uptake in the grafts of syngeneic and allogeneic recipients with or without immunosuppression treatment. Pulmonary microPET scans demonstrated significantly higher [18F]FDG uptake in rejecting allografts when compared to transplanted lungs of either immunosuppressed or syngeneic recipients. [18F]FDG uptake was also markedly attenuated following T cell depletion therapy in lung recipients with ongoing acute rejection. Flow-cytometric analysis using the fluorescent deoxyglucose analog 2-NBDG revealed that T cells, and in particular CD8+ T cells, were the largest glucose utilizers in acutely rejecting lung grafts followed by neutrophils and antigen presenting cells. These data indicate that imaging modalities tailored toward assessing T cell metabolism may be useful in identifying acute rejection in lung recipients PMID:23927673

  17. Chemosensitizing and cytotoxic effects of 2-deoxy-D-glucose on breast cancer cells

    Directory of Open Access Journals (Sweden)

    Zhang Fanjie

    2009-09-01

    Full Text Available Background: Accelerated glucose uptake for anerobic glycolysis is one of the major metabolic changes found in malignant cells. This property has been exploited for imaging malignancies and as a possible anticancer therapy. The nonmetabolizable glucose analog 2-deoxyglucose (2 DG interferes with glucose metabolism leading to breast cancer cell death. Aims: To determine whether 2DG can synergize with chemotherapeutic agents commonly used in breast cancer treatment and identify cellular characteristics associated with sensitivity to 2DG. Materials and Methods: SkBr3 breast cancer cells were incubated with varying concentrations of 5-fluorouracil (5FU, doxorubicin, cisplatin, cyclophosphamide, or herceptin with or without 2DG. Cell viability was measured using the MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay. Results: Combining 2DG with doxorubicin, 5 FU, cyclophosphamide, and herceptin resulted in enhanced cell death compared with each agent alone, while in combination with cisplatin, the amount of cell death was additive. Mouse embryo fibroblasts (MEF mutated for p53 (-/- were 30% more sensitive to the cytotoxic effects of 2DG than the parental cell lines. Cells mutated for Bax/Bac, genes involved in protection from apoptosis, are slightly more sensitive than the parental cell lines. Conclusions: These results indicate that 2DG acts synergistically with specific chemotherapeutic agents in causing cell death and the class of chemicals most sensitive appear to be those which cause DNA damage.

  18. Effect of heparin on high glucose induced proliferation and expression of matrix metalloproteinases in normal human mesangial cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qiao-ling; Arima Terukatsu; Yasumoto Yuichiro; Tsukamoto Masatoshi; Nozaki Tsuyoshi; Sogabe Atsushi; Harada Kouji; ZHANG Yi-xiang; LIN Xiao-yan; ZHANG Yang-de

    2005-01-01

    Background The pathogenesis of diabetic nephropathy (DN) is a complex pathophysiological process.Its precise mechanism is not fully known. In recent years it has been recognized that synthesis of various extracelluar matrix (ECM) components may increase, and that degradation of ECM may decrease in DN. It was reported heparin could inhibit mesangial cells proliferation in vitro. The main aim of this study is to explore whether heparin inhibits proliferation of mesangial cells grown in high glucose concentration and to measure the effect of heparin on matrix metalloproteinases (MMPs) expression in mesangial cells. Methods The medium contained either low glucose (5 mmol/L) or high glucose (25 mmol/L). The concentrations of heparin in the culture medium were 0, 25, 50,100, 200 or 400 μg/mL. A metabolic (WST-1) assay was used to measure mesangial cell proliferation and Western blot analysis was used to measure MMPs expression of mesangial cells. Results Normal human mesangial cell (NHMC) proliferation was higher in high glucose (HG) medium than in low glucose (LG) medium. They showed a 1.93 fold expansion after 72 h in high glucose in contrast to a 1.63 fold expansion in low glucose. In the presence of heparin, mesangial cells proliferation was inhibited, which was more obvious at high glucose concentrations than at low glucose concentrations. In high glucose, with heparin concentration of 50, 100, 200 and 400 μg/mL, the mesangial cells showed a 0. 61 fold, 0.52 fold, 0.52 fold and 0.41 fold reductions in cell number compared to cells grown without heparin. In low glucose, only concentrations of 200 μg/mL and 400 μg/mL showed reduction in cell number, namely 0.54 fold and 0.45 fold, when compared to cells grown without heparin. In Western blot analysis,MMP1, MMP2, MMP3 and MMP9 was expressed by mesangial cells expressed in both high and low glucose concentrations, which was more prominent in high glucose medium. Incubation of heparin further increased expression of

  19. Rewired Metabolism in Drug-resistant Leukemia Cells

    Science.gov (United States)

    Stäubert, Claudia; Bhuiyan, Hasanuzzaman; Lindahl, Anna; Broom, Oliver Jay; Zhu, Yafeng; Islam, Saiful; Linnarsson, Sten; Lehtiö, Janne; Nordström, Anders

    2015-01-01

    Cancer cells that escape induction therapy are a major cause of relapse. Understanding metabolic alterations associated with drug resistance opens up unexplored opportunities for the development of new therapeutic strategies. Here, we applied a broad spectrum of technologies including RNA sequencing, global untargeted metabolomics, and stable isotope labeling mass spectrometry to identify metabolic changes in P-glycoprotein overexpressing T-cell acute lymphoblastic leukemia (ALL) cells, which escaped a therapeutically relevant daunorubicin treatment. We show that compared with sensitive ALL cells, resistant leukemia cells possess a fundamentally rewired central metabolism characterized by reduced dependence on glutamine despite a lack of expression of glutamate-ammonia ligase (GLUL), a higher demand for glucose and an altered rate of fatty acid β-oxidation, accompanied by a decreased pantothenic acid uptake capacity. We experimentally validate our findings by selectively targeting components of this metabolic switch, using approved drugs and starvation approaches followed by cell viability analyses in both the ALL cells and in an acute myeloid leukemia (AML) sensitive/resistant cell line pair. We demonstrate how comparative metabolomics and RNA expression profiling of drug-sensitive and -resistant cells expose targetable metabolic changes and potential resistance markers. Our results show that drug resistance is associated with significant metabolic costs in cancer cells, which could be exploited using new therapeutic strategies. PMID:25697355

  20. Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach

    Directory of Open Access Journals (Sweden)

    Panazzolo Diogo G

    2012-11-01

    Full Text Available Abstract Background We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Methods Data from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m2, who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA. PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI, waist circumference, systolic and diastolic blood pressure (BP, fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c, low-density lipoprotein cholesterol (LDL-c, triglycerides (TG, insulin, C-reactive protein (CRP, and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV at rest and peak after 1 min of arterial occlusion (RBCVmax, and the time taken to reach RBCVmax (TRBCVmax. Results A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCVmax varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCVmax, but in the opposite way. Principal component 3 was

  1. Glucose metabolism and astrocyte-neuron interactions in the neonatal brain.

    Science.gov (United States)

    Brekke, Eva; Morken, Tora Sund; Sonnewald, Ursula

    2015-03-01

    Glucose is essentially the sole fuel for the adult brain and the mapping of its metabolism has been extensive in the adult but not in the neonatal brain, which is believed to rely mainly on ketone bodies for energy supply. However, glucose is absolutely indispensable for normal development and recent studies have shed light on glycolysis, the pentose phosphate pathway and metabolic interactions between astrocytes and neurons in the 7-day-old rat brain. Appropriately (13)C labeled glucose was used to distinguish between glycolysis and the pentose phosphate pathway during development. Experiments using (13)C labeled acetate provided insight into the GABA-glutamate-glutamine cycle between astrocytes and neurons. It could be shown that in the neonatal brain the part of this cycle that transfers glutamine from astrocytes to neurons is operating efficiently while, in contrast, little glutamate is shuttled from neurons to astrocytes. This lack of glutamate for glutamine synthesis is compensated for by anaplerosis via increased pyruvate carboxylation relative to that in the adult brain. Furthermore, compared to adults, relatively more glucose is prioritized to the pentose phosphate pathway than glycolysis and pyruvate dehydrogenase activity. The reported developmental differences in glucose metabolism and neurotransmitter synthesis may determine the ability of the brain at various ages to resist excitotoxic insults such as hypoxia-ischemia.

  2. Abnormal Glucose Tolerance Is Associated with a Reduced Myocardial Metabolic Flexibility in Patients with Dilated Cardiomyopathy.

    Science.gov (United States)

    Tricò, Domenico; Baldi, Simona; Frascerra, Silvia; Venturi, Elena; Marraccini, Paolo; Neglia, Danilo; Natali, Andrea

    2016-01-01

    Dilated cardiomyopathy (DCM) is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. We verified whether this pattern is influenced by an abnormal glucose tolerance (AGT). In 10 patients with DCM, 5 with normal glucose tolerance (DCM-NGT) and 5 with AGT (DCM-AGT), and 5 non-DCM subjects with AGT (N-AGT), we measured coronary blood flow and arteriovenous differences of oxygen and metabolites during Rest, Pacing (at 130 b/min), and Recovery. Myocardial lactate exchange and oleate oxidation were also measured. At Rest, DCM patients showed a reduced nonesterified fatty acids (NEFA) myocardial uptake, while glucose utilization increased only in DCM-AGT. In response to Pacing, glucose uptake promptly rose in N-AGT (from 72 ± 21 to 234 ± 73 nmol/min/g, p equivalents, p metabolism and the reduced myocardial metabolic flexibility in response to an increased workload. This trial is registered with ClinicalTrial.gov NCT02440217.

  3. Muscle insulin sensitivity and glucose metabolism are controlled by the intrinsic muscle clock★

    Science.gov (United States)

    Dyar, Kenneth A.; Ciciliot, Stefano; Wright, Lauren E.; Biensø, Rasmus S.; Tagliazucchi, Guidantonio M.; Patel, Vishal R.; Forcato, Mattia; Paz, Marcia I.P.; Gudiksen, Anders; Solagna, Francesca; Albiero, Mattia; Moretti, Irene; Eckel-Mahan, Kristin L.; Baldi, Pierre; Sassone-Corsi, Paolo; Rizzuto, Rosario; Bicciato, Silvio; Pilegaard, Henriette; Blaauw, Bert; Schiaffino, Stefano

    2013-01-01

    Circadian rhythms control metabolism and energy homeostasis, but the role of the skeletal muscle clock has never been explored. We generated conditional and inducible mouse lines with muscle-specific ablation of the core clock gene Bmal1. Skeletal muscles from these mice showed impaired insulin-stimulated glucose uptake with reduced protein levels of GLUT4, the insulin-dependent glucose transporter, and TBC1D1, a Rab-GTPase involved in GLUT4 translocation. Pyruvate dehydrogenase (PDH) activity was also reduced due to altered expression of circadian genes Pdk4 and Pdp1, coding for PDH kinase and phosphatase, respectively. PDH inhibition leads to reduced glucose oxidation and diversion of glycolytic intermediates to alternative metabolic pathways, as revealed by metabolome analysis. The impaired glucose metabolism induced by muscle-specific Bmal1 knockout suggests that a major physiological role of the muscle clock is to prepare for the transition from the rest/fasting phase to the active/feeding phase, when glucose becomes the predominant fuel for skeletal muscle. PMID:24567902

  4. Glucose metabolism in completed suicide: a forensic-pathological pilot study

    Science.gov (United States)

    Forsman, Jonas; Keltanen, Terhi; Liberg, Benny; Sajantila, Antti; Masterman, Thomas; Lindroos, Katarina

    2017-01-01

    Aim To determine whether antemortem blood levels of glycated hemoglobin (HbA1c) and glucose predict completed suicide and, by extension, whether markers of glucose metabolism might be associated with a prosuicidal trait or state. Method From consecutively performed autopsies, samples of blood and vitreous humor from 17 suicide victims and 27 non-suicide controls were compared with regard to levels of glucose, lactate, and HbA1c. Results Mean HbA1c was higher and mean estimated blood glucose was lower among suicide victims, although tests revealed no significant differences (P = 0.171 and P = 0.395, respectively). HbA1c levels exceeding 48.0 mmol/mol, which were indicative of persistent hyperglycemia, were twice as common in suicide victims (59% vs 30%; P = 0.068). Conclusion The finding of this pilot study suggest that deranged glucose metabolism may reflect biological events antecedent to, or concomitant with, completed suicide, with the following clinical implications: recurring hyperglycemia due to defective glucose transport, which may give rise to depression and suicidal ideation, and elevated HbA1c levels, which may represent an assayable correlate to neurobiological conditions predisposing to suicide. PMID:28252873

  5. Berberine improves glucose metabolism in diabetic rats by inhibition of hepatic gluconeogenesis.

    Directory of Open Access Journals (Sweden)

    Xuan Xia

    Full Text Available Berberine (BBR is a compound originally identified in a Chinese herbal medicine Huanglian (Coptis chinensis French. It improves glucose metabolism in type 2 diabetic patients. The mechanisms involve in activation of adenosine monophosphate activated protein kinase (AMPK and improvement of insulin sensitivity. However, it is not clear if BBR reduces blood glucose through other mechanism. In this study, we addressed this issue by examining liver response to BBR in diabetic rats, in which hyperglycemia was induced in Sprague-Dawley rats by high fat diet. We observed that BBR decreased fasting glucose significantly. Gluconeogenic genes, Phosphoenolpyruvate carboxykinase (PEPCK and Glucose-6-phosphatase (G6Pase, were decreased in liver by BBR. Hepatic steatosis was also reduced by BBR and expression of fatty acid synthase (FAS was inhibited in liver. Activities of transcription factors including Forkhead transcription factor O1 (FoxO1, sterol regulatory element-binding protein 1c (SREBP1 and carbohydrate responsive element-binding protein (ChREBP were decreased. Insulin signaling pathway was not altered in the liver. In cultured hepatocytes, BBR inhibited oxygen consumption and reduced intracellular adenosine triphosphate (ATP level. The data suggest that BBR improves fasting blood glucose by direct inhibition of gluconeogenesis in liver. This activity is not dependent on insulin action. The gluconeogenic inhibition is likely a result of mitochondria inhibition by BBR. The observation supports that BBR improves glucose metabolism through an insulin-independent pathway.

  6. Association between serum uric acid and different states of glucose metabolism and glomerular filtration rate

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-ling; HAN Xue-yao; JI Li-nong

    2010-01-01

    Background Recently, it has been suggested that the serum uric acid (SUA) level decreased in diabetic patients. The aim of this study was to explore the association between SUA level and different state of glucose metabolism and glomerular filtration rate (GFR) reflected by the simplified Modification of Diet in Renal Disease (MDRD) equation and to test the hypothesis that high MDRD is one of the determinants of SUA level.Methods This cross-sectional study included 2373 subjects in Beijing who underwent a 75 g oral glucose tolerance test (OGTT) for screening of diabetes. According to the states of glucose metabolism, they were divided into normal glucose tolerance, impaired glucose regulation and diabetes.Results Multiple stepwise linear regression analysis showed that adjusted by gender, SUA was positively correlated with body mass index (BMI), waist/hippo ratio, systolic blood pressure (SBP) and triglyceride, meanwhile negatively correlated with age, hemoglobin A1c, fasting insulin and MDRD. There was an increasing trend in SUA concentration and a decreasing trend in MDRD when the levels of fasting plasma glucose (FPG) increased from low to high up to the FPG level of 8.0 mmol/L; thereafter, the SUA concentration started to decrease with further increases in FPG levels, and the MDRD started to increase with further increases in FPG levels.Conclusion This study confirmed the previous finding that SUA decreased in diabetes and provided the supporting evidence that the increased MDRD might contribute to the fall of SUA.

  7. Quantification of pathways of glucose utilization and balance of energy metabolism of rabbit reticulocytes.

    Science.gov (United States)

    Siems, W; Müller, M; Dumdey, R; Holzhütter, H G; Rathmann, J; Rapoport, S M

    1982-06-01

    In this work it is demonstrated that glucose constitutes the main substrate of energy metabolism of rabbit reticulocytes under aerobic conditions in the presence of 5 mM glucose. Amino acids and fatty acids are minor sources of energy. The shares of processes utilizing glucose in reticulocytes were estimated from tracer experiments. A new mathematical technique used permits the derivation of closed terms for the specific radioactivity of single positions of C atoms of the metabolites of the citrate cycle. By means of regression analysis, the undetermined flux rates in the citrate cycle were calculated. On the basis of the data an overall balance sheet of glucose utilization and of ATP generation is given. About 45% of the glucose of reticulocytes is catabolized via the citrate cycle, about the same percentage yields lactate. Only 2% of the glucose was oxidized in the oxidative pentose pathway whereas the remainder is used for the formation of serine and glycine required for hemoglobin synthesis. These results are related to knowledge about the main processes utilizing ATP in reticulocytes, i.e. the synthesis of hemoglobin and the energy-dependent proteolysis. Our approach to the investigation of metabolic relations in the reticulocytes can be applied to other tissues in which equilibria between large metabolite pools play a role.

  8. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-02-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5omicronC for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughtout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat.

  9. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-02-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5 degrees C for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat.

  10. High glucose suppresses embryonic stem cell differentiation into neural lineage cells.

    Science.gov (United States)

    Yang, Penghua; Shen, Wei-bin; Reece, E Albert; Chen, Xi; Yang, Peixin

    2016-04-01

    Abnormal neurogenesis occurs during embryonic development in human diabetic pregnancies and in animal models of diabetic embryopathy. Our previous studies in a mouse model of diabetic embryopathy have implicated that high glucose of maternal diabetes delays neurogenesis in the developing neuroepithelium leading to neural tube defects. However, the underlying process in high glucose-impaired neurogenesis is uncharacterized. Neurogenesis from embryonic stem (ES) cells provides a valuable model for understanding the abnormal neural lineage development under high glucose conditions. ES cells are commonly generated and maintained in high glucose (approximately 25 mM glucose). Here, the mouse ES cell line, E14, was gradually adapted to and maintained in low glucose (5 mM), and became a glucose responsive E14 (GR-E14) line. High glucose induced the endoplasmic reticulum stress marker, CHOP, in GR-E14 cells. Under low glucose conditions, the GR-E14 cells retained their pluripotency and capability to differentiate into neural lineage cells. GR-E14 cell differentiation into neural stem cells (Sox1 and nestin positive cells) was inhibited by high glucose. Neuron (Tuj1 positive cells) and glia (GFAP positive cells) differentiation from GR-E14 cells was also suppressed by high glucose. In addition, high glucose delayed GR-E14 differentiation into neural crest cells by decreasing neural crest markers, paired box 3 (Pax3) and paired box 7 (Pax7). Thus, high glucose impairs ES cell differentiation into neural lineage cells. The low glucose adapted and high glucose responsive GR-E14 cell line is a useful in vitro model for assessing the adverse effect of high glucose on the development of the central nervous system.

  11. High glucose suppresses embryonic stem cell differentiation into neural lineage cells

    Science.gov (United States)

    Yang, Penghua; Shen, Wei-bin; Reece, E. Albert; Chen, Xi; Yang, Peixin

    2017-01-01

    Abnormal neurogenesis occurs during embryonic development in human diabetic pregnancies and in animal models of diabetic embryopathy. Our previous studies in a mouse model of diabetic embryopathy have implicated that high glucose of maternal diabetes delays neurogenesis in the developing neuroepithelium leading to neural tube defects. However, the underlying process in high glucose-impaired neurogenesis is uncharacterized. Neurogenesis from embryonic stem (ES) cells provides a valuable model for understanding the abnormal neural lineage development under high glucose conditions. ES cells are commonly generated and maintained in high glucose (approximately 25 mM glucose). Here, the mouse ES cell line, E14, was gradually adapted to and maintained in low glucose (5 mM), and became a glucose responsive E14 (GR-E14) line. High glucose induced the endoplasmic reticulum stress marker, CHOP, in GR-E14 cells. Under low glucose conditions, the GR-E14 cells retained their pluripotency and capability to differentiate into neural lineage cells. GR-E14 cell differentiation into neural stem cells (Sox1 and nestin positive cells) was inhibited by high glucose. Neuron (Tuj1 positive cells) and glia (GFAP positive cells) differentiation from GR-E14 cells was also suppressed by high glucose. In addition, high glucose delayed GR-E14 differentiation into neural crest cells by decreasing neural crest markers, paired box 3 (Pax3) and paired box 7 (Pax7). Thus, high glucose impairs ES cell differentiation into neural lineage cells. The low glucose adapted and high glucose responsive GR-E14 cell line is a useful in vitro model for assessing the adverse effect of high glucose on the development of the central nervous system. PMID:26940741

  12. Lactate and glucose concomitant consumption as a self-regulated pH detoxification mechanism in HEK293 cell cultures.

    Science.gov (United States)

    Liste-Calleja, Leticia; Lecina, Martí; Lopez-Repullo, Jonatan; Albiol, Joan; Solà, Carles; Cairó, Jordi Joan

    2015-12-01

    One of the most important limitations of mammalian cell-based processes is the secretion and accumulation of lactate as a by-product of their metabolism. Among the cell lines commonly used in industrial bioprocesses, HEK293 has been gaining importance over the last years. Up recently, HEK293 cells were known to consume lactate in late stages of cell culture usually when glucose and/or glutamine were depleted from media. Remarkably, in both scenarios, no significant cell growth was reported. However, we have observed a different metabolic behavior regarding lactate production and consumption in HEK293 cultures. HEK293 cells were able to co-metabolize glucose and lactate simultaneously, even in exponentially growing cell cultures. Our deep study of the effects of environmental conditions on lactate metabolism revealed that pH was the key to trigger the metabolic shift from lactate production to lactate and glucose concomitant consumption. Remarkably, this shift could be triggered at will when pH was set at 6.8. Even more interesting was the fact that lowering pH to 6.6 and supplementing media with exogenous lactate resulted in co-consumption of glucose and lactate from the beginning of cell culture, without affecting cell growth or protein productivity. On the contrary, cell growth was clearly hampered at this low pH if extracellular lactate was lacking. From our results, we hypothesize that HEK293 cells metabolize extracellular lactate as a strategy for pH detoxification, by means of co-transporting extracellular protons together with lactate into the cytosol. This novel hypothesis for unraveling lactate metabolism in HEK293 cells could open a door to re-direct genetic engineering strategies in order to obtain more efficient cell lines and also to further develop animal cell technology applications.

  13. Transgenic overexpression of intraislet ghrelin does not affect insulin secretion or glucose metabolism in vivo.

    Science.gov (United States)

    Bando, Mika; Iwakura, Hiroshi; Ariyasu, Hiroyuki; Hosoda, Hiroshi; Yamada, Go; Hosoda, Kiminori; Adachi, Souichi; Nakao, Kazuwa; Kangawa, Kenji; Akamizu, Takashi

    2012-02-15

    Whereas ghrelin is produced primarily in the stomach, a small amount of it is produced in pancreatic islets. Although exogenous administration of ghrelin suppresses insulin secretion in vitro or in vivo, the role of intraislet ghrelin in the regulation of insulin secretion in vivo remains unclear. To understand the physiological role of intraislet ghrelin in insulin secretion and glucose metabolism, we developed a transgenic (Tg) mouse model, rat insulin II promoter ghrelin-internal ribosomal entry site-ghrelin O-acyl transferase (RIP-GG) Tg mice, in which mouse ghrelin cDNA and ghrelin O-acyltransferase are overexpressed under the control of the rat insulin II promoter. Although pancreatic desacyl ghrelin levels were elevated in RIP-GG Tg mice, pancreatic ghrelin levels were not altered in animals on a standard diet. However, when Tg mice were fed a medium-chain triglyceride-rich diet (MCTD), pancreatic ghrelin levels were elevated to ∼16 times that seen in control animals. It seems likely that the gastric ghrelin cells possess specific machinery to provide the octanoyl acid necessary for ghrelin acylation but that this machinery is absent from pancreatic β-cells. Despite the overexpression of ghrelin, plasma ghrelin levels in the portal veins of RIP-GG Tg mice were unchanged from control levels. Glucose tolerance, insulin secretion, and islet architecture in RIP-GG Tg mice were not significantly different even when the mice were fed a MCTD. These results indicate that intraislet ghrelin does not play a major role in the regulation of insulin secretion in vivo.

  14. Conservation of the Nrf2-Mediated Gene Regulation of Proteasome Subunits and Glucose Metabolism in Zebrafish

    Directory of Open Access Journals (Sweden)

    Vu Thanh Nguyen

    2016-01-01

    Full Text Available The Keap1-Nrf2 system is an evolutionarily conserved defense mechanism against oxidative and xenobiotic stress. Besides the exogenous stress response, Nrf2 has been found to regulate numerous cellular functions, including protein turnover and glucose metabolism; however, the evolutionary origins of these functions remain unknown. In the present study, we searched for novel target genes associated with the zebrafish Nrf2 to answer this question. A microarray analysis of zebrafish embryos that overexpressed Nrf2 revealed that 115 candidate genes were targets of Nrf2, including genes encoding proteasome subunits and enzymes involved in glucose metabolism. A real-time quantitative PCR suggested that the expression of 3 proteasome subunits (psma3, psma5, and psmb7 and 2 enzymes involved in glucose metabolism (pgd and fbp1a were regulated by zebrafish Nrf2. We thus next examined the upregulation of these genes by an Nrf2 activator, diethyl maleate, using Nrf2 mutant zebrafish larvae. The results of real-time quantitative PCR and whole-mount in situ hybridization showed that all of these 5 genes were upregulated by diethyl maleate treatment in an Nrf2-dependent manner, especially in the liver. These findings implied that the Nrf2-mediated regulation of the proteasome subunits and glucose metabolism is evolutionarily conserved among vertebrates.

  15. Co-ordination of hepatic and adipose tissue lipid metabolism after oral glucose

    DEFF Research Database (Denmark)

    Bülow, J; Simonsen, L; Wiggins, D;

    1999-01-01

    The integration of lipid metabolism in the splanchnic bed and in subcutaneous adipose tissue before and after ingestion of a 75 g glucose load was studied by Fick's principle in seven healthy subjects. Six additional subjects were studied during a hyperinsulinemic euglycemic clamp. Release of non...

  16. Effect of opium on glucose metabolism and lipid profiles in rats with streptozotocin-induced diabetes

    NARCIS (Netherlands)

    Sadeghian, Saeed; Boroumand, Mohammad Ali; Sotoudeh-Anvari, Maryam; Rahbani, Shahram; Sheikhfathollahi, Mahmood; Abbasi, Ali

    2009-01-01

    Background: This experimental study was performed to determine the impact of opium use on serum lipid profile and glucose metabolism in rats with streptozotocin-induced diabetes. Material and methods: To determine the effect of opium, 20 male rats were divided into control (n = 10) and opium-treated

  17. Brain Size and Cerebral Glucose Metabolic Rate in Nonspecific Retardation and Down Syndrome.

    Science.gov (United States)

    Haier, Richard J.; And Others

    1995-01-01

    Brain size and cerebral glucose metabolic rate were determined for 10 individuals with mild mental retardation (MR), 7 individuals with Down syndrome (DS), and 10 matched controls. MR and DS groups both had brain volumes of about 80% compared to controls, with variance greatest within the MR group. (SLD)

  18. Sleep deprivation and its impact on circadian rhythms and glucose metabolism

    NARCIS (Netherlands)

    Jha, P.K.

    2016-01-01

    The mammalian master pacemaker is located in the hypothalamic suprachiasmatic nucleus (SCN). The SCN generates rhythms of behavioural and metabolic processes throughout the body via both endocrine and neuronal outputs. For example, daily rhythms of sleep-wake, fasting-feeding, plasma glucose, glucos

  19. Brain-derived neurotrophic factor, impaired glucose metabolism, and bipolar disorder course

    DEFF Research Database (Denmark)

    Mansur, Rodrigo B; Santos, Camila M; Rizzo, Lucas B

    2016-01-01

    OBJECTIVES: The neurotrophin brain-derived neurotrophic factor (BDNF) has been proposed as a potential biomarker in bipolar disorder (BD). However, current evidence is limited and results have been highly heterogeneous. This study aimed to assess the moderating effect of impaired glucose metabolism...

  20. Glucose and maltose metabolism in MIG1-disrupted and MAL-constitutive strains of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B;

    1997-01-01

    The alleviation of glucose control of maltose metabolism brought about by MIG1 disruption was compared to that by MAL overexpression in a haploid Saccharomyces cerevisiae strain. The sugar consumption profiles during cultivation of the wild type, single transformants and a double transformant in ...

  1. Low Cerebral Glucose Metabolism: A Potential Predictor for the Severity of Vascular Parkinsonism and Parkinson's Disease.

    Science.gov (United States)

    Xu, Yunqi; Wei, Xiaobo; Liu, Xu; Liao, Jinchi; Lin, Jiaping; Zhu, Cansheng; Meng, Xiaochun; Xie, Dongsi; Chao, Dongman; Fenoy, Albert J; Cheng, Muhua; Tang, Beisha; Zhang, Zhuohua; Xia, Ying; Wang, Qing

    2015-11-01

    This study explored the association between cerebral metabolic rates of glucose (CMRGlc) and the severity of Vascular Parkinsonism (VP) and Parkinson's disease (PD). A cross-sectional study was performed to compare CMRGlc in normal subjects vs. VP and PD patients. Twelve normal subjects, 22 VP, and 11 PD patients were evaluated with the H&Y and MMSE, and underwent 18F-FDG measurements. Pearson's correlations were used to identify potential associations between the severity of VP/PD and CMRGlc. A pronounced reduction of CMRGlc in the frontal lobe and caudate putamen was detected in patients with VP and PD when compared with normal subjects. The VP patients displayed a slight CMRGlc decrease in the caudate putamen and frontal lobe in comparison with PD patients. These decreases in CMRGlc in the frontal lobe and caudate putamen were significantly correlated with the VP patients' H&Y, UPDRS II, UPDRS III, MMSE, cardiovascular, and attention/memory scores. Similarly, significant correlations were observed in patients with PD. This is the first clinical study finding strong evidence for an association between low cerebral glucose metabolism and the severity of VP and PD. Our findings suggest that these changes in glucose metabolism in the frontal lobe and caudate putamen may underlie the pathophysiological mechanisms of VP and PD. As the scramble to find imaging biomarkers or predictors of the disease intensifies, a better understanding of the roles of cerebral glucose metabolism may give us insight into the pathogenesis of VP and PD.

  2. Leptin regulates energy metabolism in MCF-7 breast cancer cells.

    Science.gov (United States)

    Blanquer-Rosselló, Maria del Mar; Oliver, Jordi; Sastre-Serra, Jorge; Valle, Adamo; Roca, Pilar

    2016-03-01

    Obesity is known to be a poorer prognosis factor for breast cancer in postmenopausal women. Among the diverse endocrine factors associated to obesity, leptin has received special attention since it promotes breast cancer cell growth and invasiveness, processes which force cells to adapt their metabolism to satisfy the increased demands of energy and biosynthetic intermediates. Taking this into account, our aim was to explore the effects of leptin in the metabolism of MCF-7 breast cancer cells. Polarographic analysis revealed that leptin increased oxygen consumption rate and cellular ATP levels were more dependent on mitochondrial oxidative metabolism in leptin-treated cells compared to the more glycolytic control cells. Experiments with selective inhibitors of glycolysis (2-DG), fatty acid oxidation (etomoxir) or aminoacid deprivation showed that ATP levels were more reliant on fatty acid oxidation. In agreement, levels of key proteins involved in lipid catabolism (FAT/CD36, CPT1, PPARα) and phosphorylation of the energy sensor AMPK were increased by leptin. Regarding glucose, cellular uptake was not affected by leptin, but lactate release was deeply repressed. Analysis of pyruvate dehydrogenase (PDH), lactate dehydrogenase (LDH) and pyruvate carboxylase (PC) together with the pentose-phosphate pathway enzyme glucose-6 phosphate dehydrogenase (G6PDH) revealed that leptin favors the use of glucose for biosynthesis. These results point towards a role of leptin in metabolic reprogramming, consisting of an enhanced use of glucose for biosynthesis and lipids for energy production. This metabolic adaptations induced by leptin may provide benefits for MCF-7 growth and give support to the reverse Warburg effect described in breast cancer.

  3. Effect of Antibiotics on Gut Microbiota, Gut Hormones and Glucose Metabolism

    DEFF Research Database (Denmark)

    Mikkelsen, Kristian H; Frost, Morten; Bahl, Martin Iain;

    2015-01-01

    The gut microbiota has been designated as an active regulator of glucose metabolism and metabolic phenotype in a number of animal and human observational studies. We evaluated the effect of removing as many bacteria as possible by antibiotics on postprandial physiology in healthy humans. Meal tests...... and glucose tolerant males. Faecal samples were collected for culture-based assessment of changes in gut microbiota composition. Acute and dramatic reductions in the abundance of a representative set of gut bacteria was seen immediately following the antibiotic course, but no changes in postprandial glucose...... tolerance, insulin secretion or plasma lipid concentrations were found. Apart from an acute and reversible increase in peptide YY secretion, no changes were observed in postprandial gut hormone release. As evaluated by selective cultivation of gut bacteria, a broad-spectrum 4-day antibiotics course...

  4. Glucose Metabolism via the Pentose Phosphate Pathway, Glycolysis and Krebs Cycle in an Orthotopic Mouse Model of Human Brain Tumors

    Science.gov (United States)

    Marin-Valencia, Isaac; Cho, Steve K.; Rakheja, Dinesh; Hatanpaa, Kimmo J.; Kapur, Payal; Mashimo, Tomoyuki; Jindal, Ashish; Vemireddy, Vamsidhara; Good, Levi B.; Raisanen, Jack; Sun, Xiankai; Mickey, Bruce; Choi, Changho; Takahashi, Masaya; Togao, Osamu; Pascual, Juan M.; DeBerardinis, Ralph J.; Maher, Elizabeth A.; Malloy, Craig R.; Bachoo, Robert M.

    2013-01-01

    It has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using an orthotopic mouse model of primary human glioblastoma (GBM) and a brain metastatic renal tumor of clear cell renal cell carcinoma (CCRCC) histology, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-13C2]glucose. The [3-13C]lactate/[2,3-13C2]lactate ratio was similar for both the GBM and renal tumor and their respective surrounding brains (GBM: 0.197 ± 0.011 and 0.195 ± 0.033 (p=1); CCRCC: 0.126 and 0.119 ± 0.033, respectively). This suggests that the rate of glycolysis is significantly greater than PPP flux in these tumors, and that PPP flux into the lactate pool was similar in both tissues. Remarkably, 13C-13C coupling was observed in molecules derived from Krebs cycle intermediates in both tumors, denoting glucose oxidation. In the renal tumor, in contrast to GBM and surrounding brain, 13C multiplets of GABA differed from its precursor glutamate, suggesting that GABA did not derive from a common glutamate precursor pool. Additionally, the orthotopic renal tumor, the patient’s primary renal mass and brain metastasis were all strongly immunopositive for the 67-kDa isoform of glutamate decarboxylase, as were 84% of tumors on a CCRCC tissue microarray suggesting that GABA synthesis is cell-autonomous in at least a subset of renal tumors. Taken together, these data demonstrate that 13C-labeled glucose can be used in orthotopic mouse models to study tumor metabolism in vivo and to ascertain new metabolic targets for cancer diagnosis and therapy. PMID:22383401

  5. Longitudinal Associations of Exposure to Perfluoroalkylated Substances in Childhood and Adolescence and Indicators of Adiposity and Glucose Metabolism 6 and 12 Years Later

    DEFF Research Database (Denmark)

    Domazet, Sidsel Louise; Grøntved, Anders; Timmermann, Clara Amalie Gade;

    2016-01-01

    OBJECTIVE: To investigate the long-term association of exposure to perfluoroalkylated substances, including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), during childhood (9 years) and adolescence (15 years) on indicators of adiposity and glucose metabolism in adolescence...... childhood (N = 590), during adolescence (N = 444), and into young adulthood (N = 369). Stored plasma samples were analyzed for PFOS and PFOA. Indicators of adiposity comprising body height, body weight, sum of four skinfolds, and waist circumference; as well as indicators of glucose metabolism, comprising...... was associated with decreased β-cell function at 15 years of age. We did not observe associations between exposure during adolescence and indicators of adiposity and glucose metabolism in young adulthood. CONCLUSIONS: This study found evidence for childhood exposure to PFOS and PFOA predicting adiposity at 15...

  6. Germinated Pigmented Rice (Oryza Sativa L. cv. Superhongmi Improves Glucose and Bone Metabolisms in Ovariectomized Rats

    Directory of Open Access Journals (Sweden)

    Soo Im Chung

    2016-10-01

    Full Text Available The effect of germinated Superhongmi, a reddish brown pigmented rice cultivar, on the glucose profile and bone turnover in the postmenopausal-like model of ovariectomized rats was determined. The ovariectomized Sprague-Dawley rats were randomly divided into three dietary groups (n = 10: normal control diet (NC and normal diet supplemented with non-germinated Superhongmi (SH or germinated Superhongmi (GSH rice powder. After eight weeks, the SH and GSH groups showed significantly lower body weight, glucose and insulin concentrations, levels of bone resorption markers and higher glycogen and 17-β-estradiol contents than the NC group. The glucose metabolism improved through modulation of adipokine production and glucose-regulating enzyme activities. The GSH rats exhibited a greater hypoglycemic effect and lower bone resorption than SH rats. These results demonstrate that germinated Superhongmi rice may potentially be useful in the prevention and management of postmenopausal hyperglycemia and bone turnover imbalance.

  7. Role of ZAC1 in transient neonatal diabetes mellitus and glucose metabolism

    Institute of Scientific and Technical Information of China (English)

    Anke; Hoffmann; Dietmar; Spengler

    2015-01-01

    Transient neonatal diabetes mellitus 1(TNDM1) is a rare genetic disorder representing with severe neonatal hyperglycaemia followed by remission within one and a half year and adolescent relapse with type 2 diabetes in half of the patients. Genetic defects in TNDM1 comprise uniparental isodisomy of chromosome 6, duplication of the minimal TNDM1 locus at 6q24, or relaxation of genomically imprinted ZAC1 /HYMAI. Whereas the function of HYMAI, a non-coding m RNA, is still unidentified, biochemical and molecular studies show that zinc finger protein 1 regulating apoptosis and cell cycle arrest(ZAC1) behaves as a factor with versatile transcriptional functions dependent on binding to specific GC-rich DNA motives and interconnected regulation of recruited coactivator activities. Genome-wide expression profiling enabled the isolation of a number of Zac1 target genes known to regulate different aspects of β-cell function and peripheral insulin sensitivity. Among these, upregulation of Pparγ and Tcf4 impairs insulinsecretion and β-cell proliferation. Similarly, Zac1-mediated upregulation of Socs3 may attenuate β-cell proliferation and survival by inhibition of growth factor signalling. Additionally, Zac1 directly represses Pac1 and Rasgrf1 with roles in insulin secretion and β-cell proliferation. Collectively, concerted dysregulation of these target genes could contribute to the onset and course of TNDM1. Interestingly, Zac1 overexpression in β-cells spares the effects of stimulatory G-protein signaling on insulin secretion and raises the prospect for tailored treatments in relapsed TNDM1 patients. Overall, these results suggest that progress on the molecular and cellular foundations of monogenetic forms of diabetes can advance personalized therapy in addition to deepening the understanding of insulin and glucose metabolism in general.

  8. Role of ZAC1 in transient neonatal diabetes mellitus and glucose metabolism.

    Science.gov (United States)

    Hoffmann, Anke; Spengler, Dietmar

    2015-08-26

    Transient neonatal diabetes mellitus 1 (TNDM1) is a rare genetic disorder representing with severe neonatal hyperglycaemia followed by remission within one and a half year and adolescent relapse with type 2 diabetes in half of the patients. Genetic defects in TNDM1 comprise uniparental isodisomy of chromosome 6, duplication of the minimal TNDM1 locus at 6q24, or relaxation of genomically imprinted ZAC1/HYMAI. Whereas the function of HYMAI, a non-coding mRNA, is still unidentified, biochemical and molecular studies show that zinc finger protein 1 regulating apoptosis and cell cycle arrest (ZAC1) behaves as a factor with versatile transcriptional functions dependent on binding to specific GC-rich DNA motives and interconnected regulation of recruited coactivator activities. Genome-wide expression profiling enabled the isolation of a number of Zac1 target genes known to regulate different aspects of β-cell function and peripheral insulin sensitivity. Among these, upregulation of Pparγ and Tcf4 impairs insulin-secretion and β-cell proliferation. Similarly, Zac1-mediated upregulation of Socs3 may attenuate β-cell proliferation and survival by inhibition of growth factor signalling. Additionally, Zac1 directly represses Pac1 and Rasgrf1 with roles in insulin secretion and β-cell proliferation. Collectively, concerted dysregulation of these target genes could contribute to the onset and course of TNDM1. Interestingly, Zac1 overexpression in β-cells spares the effects of stimulatory G-protein signaling on insulin secretion and raises the prospect for tailored treatments in relapsed TNDM1 patients. Overall, these results suggest that progress on the molecular and cellular foundations of monogenetic forms of diabetes can advance personalized therapy in addition to deepening the understanding of insulin and glucose metabolism in general.

  9. Increased adiposity, dysregulated glucose metabolism and systemic inflammation in Galectin-3 KO mice.

    Directory of Open Access Journals (Sweden)

    Jingbo Pang

    Full Text Available Obesity and type 2 diabetes are associated with increased production of Galectin-3 (Gal-3, a protein that modulates inflammation and clearance of glucose adducts. We used Lean and Diet-induced Obese (DIO WT and Gal-3 KO mice to investigate the role of Gal-3 in modulation of adiposity, glucose metabolism and inflammation. Deficiency of Gal-3 lead to age-dependent development of excess adiposity and systemic inflammation, as indicated by elevated production of acute-phase proteins, number of circulating pro-inflammatory Ly6C(high monocytes and development of neutrophilia, microcytic anemia and thrombocytosis in 20-week-old Lean and DIO male Gal-3 KO mice. This was associated with impaired fasting glucose, heightened response to a glucose tolerance test and reduced adipose tissue expression of adiponectin, Gal-12, ATGL and PPARγ, in the presence of maintained insulin sensitivity and hepatic expression of gluconeogenic enzymes in 20-week-old Gal-3 KO mice compared to their diet-matched WT controls. Expression of PGC-1α and FGF-21 in the liver of Lean Gal-3 KO mice was comparable to that observed in DIO animals. Impaired fasting glucose and altered responsiveness to a glucose load preceded development of excess adiposity and systemic inflammation, as demonstrated in 12-week-old Gal-3 KO mice. Finally, a role for the microflora in mediating the fasting hyperglycemia, but not the excessive response to a glucose load, of 12-week-old Gal-3 KO mice was demonstrated by administration of antibiotics. In conclusion, Gal-3 is an important modulator of glucose metabolism, adiposity and inflammation.

  10. Glucose metabolism in batch and continuous cultures of Gluconacetobacter diazotrophicus PAL 3.

    Science.gov (United States)

    Luna, María F; Bernardelli, Cecilia E; Galar, María L; Boiardi, José L

    2006-03-01

    Periplasmic glucose oxidation (by way of a pyrrolo-quinoline-quinone [PQQ]-linked glucose dehydrogenase [GDH]) was observed in continuous cultures of Gluconacetobacter diazotrophicus regardless of the carbon source (glucose or gluconate) and the nitrogen source (N(2) or NH(3)). Its synthesis was stimulated by conditions of high energetic demand (i.e., N(2)-fixation) and/or C-limitation. Under C-excess conditions, PQQ-GDH synthesis increased with the glucose concentration in the culture medium. In batch cultures, PQQ-GDH was actively expressed in very early stages with higher activities under conditions of N(2)-fixation. Hexokinase activity was almost absent under any culture condition. Cytoplasmic nicotinamide adenine dinucleotide (NAD)-linked glucose dehydrogenase (GDH) was expressed in continuous cultures under all tested conditions, and its synthesis increased with the glucose concentration. In contrast, low activities of this enzyme were detected in batch cultures. Periplasmic oxidation, by way of PQQ-GDH, seems to be the principal pathway for metabolism of glucose in G. Diazotrophicus, and NAD-GDH is an alternative route under certain environmental conditions.

  11. Effect of breakfast skipping on diurnal variation of energy metabolism and blood glucose.

    Science.gov (United States)

    Kobayashi, Fumi; Ogata, Hitomi; Omi, Naomi; Nagasaka, Shoichiro; Yamaguchi, Sachiko; Hibi, Masanobu; Tokuyama, Kumpei

    2014-01-01

    Epidemiological studies suggest an association between breakfast skipping and body weight gain, insulin resistance or type 2 diabetes. Time when meal is consumed affects postprandial increase in energy expenditure and blood glucose, and breakfast skipping may reduce 24 h energy expenditure and elevate blood glucose level. The present study evaluated the effect of breakfast skipping on diurnal variation of energy metabolism and blood glucose. The skipped breakfast was compensated by following big meals at lunch and supper. In a randomized repeated-measure design with or without breakfast, eight males stayed twice in a room-size respiratory chamber. Blood glucose was recorded with a continuous glucose monitoring system. Breakfast skipping did not affect 24 h energy expenditure, fat oxidation and thermic effect of food, but increased overall 24 h average of blood glucose (83 ± 3 vs 89 ± 2 mg/dl, P breakfast skipping. These observations suggest that changes in glucose homeostasis precede that of energy balance, in the potential sequence caused by breakfast skipping, if this dietary habit has any effect on energy balance.:

  12. High glucose-mediated oxidative stress impairs cell migration.

    Directory of Open Access Journals (Sweden)

    Marcelo L Lamers

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG, 25 mM D-glucose (high glucose, HG or 25 mM L-glucose medium (osmotic control--OC, we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC. We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients.

  13. A membraneless single compartment abiotic glucose fuel cell

    Science.gov (United States)

    Slaughter, Gymama; Sunday, Joshua

    2014-09-01

    A simple energy harvesting strategy has been developed to selectively catalyze glucose in the presence of oxygen in a glucose/O2 fuel cell. The anode consists of an abiotic catalyst Al/Au/ZnO, in which ZnO seed layer was deposited on the surface of Al/Au substrate using hydrothermal method. The cathode is constructed from a single rod of platinum with an outer diameter of 500 μm. The abiotic glucose fuel cell was studied in phosphate buffer solution (pH 7.4) containing 5 mM glucose at a temperature of 22 °C. The cell is characterized according to its open-circuit voltage, polarization profile, and power density plot. Under these conditions, the abiotic glucose fuel cell possesses an open-circuit voltage of 840 mV and delivered a maximum power density of 16.2 μW cm-2 at a cell voltage of 495 mV. These characteristics are comparable to biofuel cell utilizing a much more complex system design. Such low-cost lightweight abiotic catalyzed glucose fuel cells have a great promise to be optimized, miniaturized to power bio-implantable devices.

  14. A randomized trial comparing the effect of weight loss and exercise training on insulin sensitivity and glucose metabolism in coronary artery disease

    DEFF Research Database (Denmark)

    Pedersen, Lene Rørholm; Olsen, Rasmus Huan; Jürs, Anders

    2015-01-01

    AIM: The majority of patients with coronary artery disease (CAD) exhibit abnormal glucose metabolism, which is associated with mortality even at non-diabetic glucose levels. This trial aims to compare the effects of a considerable weight loss and exercise with limited weight loss on glucose...... followed by 2-4 weeks' weight maintenance diet. Glucose tolerance, insulin action, β-cell function and suppression of lipolysis were assessed using a 3-h oral glucose tolerance test. ISI-composite and ISI-HOMA (=1/HOMA-IR) were calculated as surrogate measures of whole-body and hepatic insulin sensitivity......, respectively. Magnetic resonance imaging estimated abdominal adipose tissue. Twenty-six (74%) AIT and 29 (83%) LED participants completed intervention per protocol. LED increased ISI-composite by 55% and ISI-HOMA by 70% (p0.7) revealing a significant...

  15. Regional changes in glucose metabolism during brain development from the age of 6 years.

    Science.gov (United States)

    Van Bogaert, P; Wikler, D; Damhaut, P; Szliwowski, H B; Goldman, S

    1998-07-01

    Positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) studies of 42 subjects ages 6 to 38 years were analyzed using statistical parametric mapping to identify age-related changes in regional distribution of glucose metabolism adjusted for global activity. Whereas adults were normal volunteers, children had idiopathic epilepsy. We studied polynomial expansions of age to identify nonlinear effects and found that adjusted glucose metabolism varied very significantly in the thalamus and the anterior cingulate cortex and to a lesser degree in the basal ganglia, the mesencephalon, and the insular, posterior cingulate, frontal, and postcentral cortices. Regression plots slowed that the best fit was not linear: adjusted glucose metabolism increased mainly before the age of 25 years and then remained relatively stable. Effects persisted when anti-epileptic drug intake and sleep during the FDG uptake were considered as confounding covariates. To determine if the metabolic changes observed were not due to the epileptic condition of the children, PET data obtained in adults with temporal lobe epilepsy were compared with those in our group of normal adult subjects, resulting in the absence of mapping in the age-related regions. This study suggests that brain maturation from the age of 6 years gives rise to a relative increase of synaptic activities in the thalamus, possibly as a consequence of improved corticothalamic connections. Increased metabolic activity in the anterior cingulate cortex is probably related to these thalamic changes and suggests that the limbic system is involved in the processes of brain maturation.

  16. Partial inhibition of adipose tissue lipolysis improves glucose metabolism and insulin sensitivity without alteration of fat mass.

    Directory of Open Access Journals (Sweden)

    Amandine Girousse

    Full Text Available When energy is needed, white adipose tissue (WAT provides fatty acids (FAs for use in peripheral tissues via stimulation of fat cell lipolysis. FAs have been postulated to play a critical role in the development of obesity-induced insulin resistance, a major risk factor for diabetes and cardiovascular disease. However, whether and how chronic inhibition of fat mobilization from WAT modulates insulin sensitivity remains elusive. Hormone-sensitive lipase (HSL participates in the breakdown of WAT triacylglycerol into FAs. HSL haploinsufficiency and treatment with a HSL inhibitor resulted in improvement of insulin tolerance without impact on body weight, fat mass, and WAT inflammation in high-fat-diet-fed mice. In vivo palmitate turnover analysis revealed that blunted lipolytic capacity is associated with diminution in FA uptake and storage in peripheral tissues of obese HSL haploinsufficient mice. The reduction in FA turnover was accompanied by an improvement of glucose metabolism with a shift in respiratory quotient, increase of glucose uptake in WAT and skeletal muscle, and enhancement of de novo lipogenesis and insulin signalling in liver. In human adipocytes, HSL gene silencing led to improved insulin-stimulated glucose uptake, resulting in increased de novo lipogenesis and activation of cognate gene expression. In clinical studies, WAT lipolytic rate was positively and negatively correlated with indexes of insulin resistance and WAT de novo lipogenesis gene expression, respectively. In obese individuals, chronic inhibition of lipolysis resulted in induction of WAT de novo lipogenesis gene expression. Thus, reduction in WAT lipolysis reshapes FA fluxes without increase of fat mass and improves glucose metabolism through cell-autonomous induction of fat cell de novo lipogenesis, which contributes to improved insulin sensitivity.

  17. Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine) (and others)

    1989-11-01

    Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author).

  18. Deoxyglucose method for the estimation of local myocardial glucose metabolism with positron computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ratib, O.; Phelps, M.E.; Huang, S.C.; Henze, E.; Selin, C.E.; Schelbert, H.R.

    1981-01-01

    The deoxyglucose method originally developed for measurements of the local cerebral metabolic rate for glucose has been investigated in terms of its application to studies of the heart with positron computed tomography (PCT) and FDG. Studies were performed in dogs to measure the tissue kinetics of FDG with PCT and by direct arterial-venous sampling. The operational equation developed in our laboratory as an extension of the Sokoloff model was used to analyze the data. The FDG method accurately predicted the true MMRGlc even when the glucose metabolic rate was normal but myocardial blood flow (MBF) was elevated 5 times the control value or when metabolism was reduced to 10% of normal and MBF increased 5 times normal. Improvements in PCT resolution are required to improve the accuracy of the estimates of the rate constants and the MMRGlc.

  19. Determination of patterns of regional cerebral glucose metabolism in normal aging and dementia

    Energy Technology Data Exchange (ETDEWEB)

    Alavi, A.; Chawluk, J.; Hurtig, H.; Dann, R.; Rosen, M.; Kushner, M.; Silver, F.; Reivich, M.

    1985-05-01

    Regional cerebral metabolic rates for glucose (rCMRGlc) were measured using 18F-FDG and positron emission tomography (PET) in 14 patients with probable Alzheimer's disease (AD) (age=64), 9 elderly controls (age=61), and 9 young controls (age=28). PET studies were performed without sensory stimulation or deprivation. Metabolic rates in individual brain regions were determined using an atlas overlay. Relative metabolic rates (rCMRGl c/global CMRGlc) were determined for all subjects. Comparison of young and elderly controls demonstrated significant decreases in frontal metabolism (rho<0.005) and right inferior parietal (IP) metabolism (rho<0.02) with normal aging. Patients with mild-moderate AD (NMAD) (n=8) when compared to age-matched controls, showed further reduction in right IP metabolism (rho<0.02). SAD patients also demonstrated metabolic decrements in left hemisphere language areas (rho<0.01). This latter finding is consistent with language disturbance observed late in the course of the disease. Out data reveal progressive changes in patterns of cerebral glucose utilization with aging and demential with reflect salient clinical features of these processes.

  20. Subcellular characterization of glucose uptake in coronary endothelial cells.

    Science.gov (United States)

    Gaudreault, N; Scriven, D R L; Laher, I; Moore, E D W

    2008-01-01

    Despite all the evidence linking glucose toxicity to an increased risk of cardiovascular diseases, very little is known about the regulation of glucose uptake in endothelial cells. We have previously reported an asymmetric distribution of the GLUTs (1-5) and SGLT-1 in en face preparations of rat coronary artery endothelia [Gaudreault N., Scriven D.R., Moore E.D., 2004. Characterisation of glucose transporters in the intact coronary artery endothelium in rats: GLUT-2 upregulated by long-term hyperglycaemia. Diabetologia 47(12),2081-2092]. We assessed this time, through immunocytochemistry and wide field fluorescence microscopy coupled to deconvolution, the presence and subcellular distribution of glucose transporters in cultures of human coronary artery endothelial cells (HCAECs). HCAECs express GLUT-1 to 5 and SGLT-1, but their subcellular distribution lacks the luminal/abluminal asymmetry and the proximity to cell-to-cell junctions observed in intact endothelium. To determine the impact of the transporters' distribution on intracellular glucose accumulation, a fluorescent glucose analog (2-NBDG) was used in conjunction with confocal microscopy to monitor uptake in individual cells; the arteries were mounted in an arteriograph chamber with physiological flow rates. The uptake in both preparations was inhibited by cytochalasin-B and d-glucose and stimulated by insulin, but the distribution of the incorporated 2-NBDG mirrored that of the transporters. In HCAEC it was distributed throughout the cell and in the intact arterial endothelium it was restricted to the narrow cytosolic volume adjacent to the cell-to-cell junctions. We suggest that the latter subcellular organization and compartmentalization may facilitate transendothelial transport of glucose in intact coronary artery.

  1. Metformin Decouples Phospholipid Metabolism in Breast Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Tim A D Smith

    Full Text Available The antidiabetic drug metformin, currently undergoing trials for cancer treatment, modulates lipid and glucose metabolism both crucial in phospholipid synthesis. Here the effect of treatment of breast tumour cells with metformin on phosphatidylcholine (PtdCho metabolism which plays a key role in membrane synthesis and intracellular signalling has been examined.MDA-MB-468, BT474 and SKBr3 breast cancer cell lines were treated with metformin and [3H-methyl]choline and [14C(U]glucose incorporation and lipid accumulation determined in the presence and absence of lipase inhibitors. Activities of choline kinase (CK, CTP:phosphocholine cytidylyl transferase (CCT and PtdCho-phospholipase C (PLC were also measured. [3H] Radiolabelled metabolites were determined using thin layer chromatography.Metformin-treated cells exhibited decreased formation of [3H]phosphocholine but increased accumulation of [3H]choline by PtdCho. CK and PLC activities were decreased and CCT activity increased by metformin-treatment. [14C] incorporation into fatty acids was decreased and into glycerol was increased in breast cancer cells treated with metformin incubated with [14C(U]glucose.This is the first study to show that treatment of breast cancer cells with metformin induces profound changes in phospholipid metabolism.

  2. The glucose metabolite methylglyoxal inhibits expression of the glucose transporter genes by inactivating the cell surface glucose sensors Rgt2 and Snf3 in yeast.

    Science.gov (United States)

    Roy, Adhiraj; Hashmi, Salman; Li, Zerui; Dement, Angela D; Cho, Kyu Hong; Kim, Jeong-Ho

    2016-03-01

    Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations at their putative ubiquitin-acceptor lysine residues are resistant to MG-induced degradation. These results suggest that the glucose sensors are inactivated through ubiquitin-mediated endocytosis and degraded in the presence of MG. In addition, the inhibitory effect of MG on the glucose sensors is greatly enhanced in cells lacking Glo1, a key component of the MG detoxification system. Thus the stability of these glucose sensors seems to be critically regulated by intracellular MG levels. Taken together, these findings suggest that MG attenuates glycolysis by promoting degradation of the cell-surface glucose sensors and thus identify MG as a potential glycolytic inhibitor.

  3. Human regional cerebral glucose metabolism during non-rapid eye movement sleep in relation to waking.

    Science.gov (United States)

    Nofzinger, Eric A; Buysse, Daniel J; Miewald, Jean M; Meltzer, Carolyn C; Price, Julie C; Sembrat, Robert C; Ombao, Hernando; Reynolds, Charles F; Monk, Timothy H; Hall, Martica; Kupfer, David J; Moore, Robert Y

    2002-05-01

    Sleep is an essential human function. Although the function of sleep has generally been regarded to be restorative, recent data indicate that it also plays an important role in cognition. The neurobiology of human sleep is most effectively analysed with functional imaging, and PET studies have contributed substantially to our understanding of both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. In this study, PET was used to determine patterns of regional glucose metabolism in NREM sleep compared with waking. We hypothesized that brain structures related to waking cognitive function would show a persistence of function into the NREM sleep state. Fourteen healthy subjects (age range 21-49 years; 10 women, 4 men) underwent concurrent EEG sleep studies and [(18)F]fluoro-2-deoxy-D-glucose PET scans during waking and NREM sleep. Whole-brain glucose metabolism declined significantly from waking to NREM sleep. Relative decreases in regional metabolism from waking to NREM sleep occurred in wide areas of frontal, parietal, temporal and occipital association cortex, primary visual cortex, and in anterior/dorsomedial thalamus. After controlling for the whole-brain declines in absolute metabolism, relative increases in regional metabolism from waking to NREM were found bilaterally in the dorsal pontine tegmentum, hypothalamus, basal forebrain, ventral striatum, anterior cingulate cortex and extensive regions of the mesial temporal lobe, including the amygdala and hippocampus, and in the right dorsal parietal association cortex and primary somatosensory and motor cortices. The reductions in relative metabolism in NREM sleep compared with waking are consistent with prior findings from blood flow studies. The relative increases in glucose utilization in the basal forebrain, hypothalamus, ventral striatum, amygdala, hippocampus and pontine reticular formation are new observations that are in accordance with the view that NREM sleep is important to brain

  4. Acute Alcohol Intoxication Decreases Glucose Metabolism but Increases Acetate Uptake in the Human Brain

    Science.gov (United States)

    Volkow, Nora D.; Kim, Sung Won; Wang, Gene-Jack; Alexoff, David; Logan, Jean; Muench, Lisa; Shea, Colleen; Telang, Frank; Fowler, Joanna S.; Wong, Christopher; Benveniste, Helene; Tomasi, Dardo

    2012-01-01

    Alcohol intoxication results in marked reductions in brain glucose metabolism, which we hypothesized reflect not just its GABAergic enhancing effects but also metabolism of acetate as an alternative brain energy source. To test this hypothesis we separately assessed the effects of alcohol intoxication on brain glucose and acetate metabolism using Positron Emission Tomography (PET). We found that alcohol intoxication significantly decreased whole brain glucose metabolism (measured with FDG) with the largest decrements in cerebellum and occipital cortex and the smallest in thalamus. In contrast, alcohol intoxication caused a significant increase in [1-11C]acetate brain uptake (measured as standard uptake value, SUV), with the largest increases occurring in cerebellum and the smallest in thalamus. In heavy alcohol drinkers [1-11C]acetate brain uptake during alcohol challenge trended to be higher than in occasional drinkers (p <0.06) and the increases in [1-11C]acetate uptake in cerebellum with alcohol were positively associated with the reported amount of alcohol consumed (r=0.66, p<0.01). Our findings corroborate a reduction of brain glucose metabolism during intoxication and document an increase in brain acetate uptake. The opposite changes observed between regional brain metabolic decrements and regional increases in [1-11C]acetate uptake support the hypothesis that during alcohol intoxication the brain may rely on acetate as an alternative brain energy source and provides preliminary evidence that heavy alcohol exposures may facilitate the use of acetate as an energy substrate. These findings raise the question of the potential therapeutic benefits that increasing plasma acetate concentration (ie ketogenic diets) may have in alcoholics undergoing alcohol detoxification. PMID:22947541

  5. Metabolic regulation of collagen gel contraction by porcine aortic valvular interstitial cells.

    Science.gov (United States)

    Kamel, Peter I; Qu, Xin; Geiszler, Andrew M; Nagrath, Deepak; Harmancey, Romain; Taegtmeyer, Heinrich; Grande-Allen, K Jane

    2014-12-06

    Despite a high incidence of calcific aortic valve disease in metabolic syndrome, there is little information about the fundamental metabolism of heart valves. Cell metabolism is a first responder to chemical and mechanical stimuli, but it is unknown how such signals employed in valve tissue engineering impact valvular interstitial cell (VIC) biology and valvular disease pathogenesis. In this study porcine aortic VICs were seeded into three-dimensional collagen gels and analysed for gel contraction, lactate production and glucose consumption in response to manipulation of metabolic substrates, including glucose, galactose, pyruvate and glutamine. Cell viability was also assessed in two-dimensional culture. We found that gel contraction was sensitive to metabolic manipulation, particularly in nutrient-depleted medium. Contraction was optimal at an intermediate glucose concentration (2 g l(-1)) with less contraction with excess (4.5 g l(-1)) or reduced glucose (1 g l(-1)). Substitution with galactose delayed contraction and decreased lactate production. In low sugar concentrations, pyruvate depletion reduced contraction. Glutamine depletion reduced cell metabolism and viability. Our results suggest that nutrient depletion and manipulation of metabolic substrates impacts the viability, metabolism and contractile behaviour of VICs. Particularly, hyperglycaemic conditions can reduce VIC interaction with and remodelling of the extracellular matrix. These results begin to link VIC metabolism and macroscopic behaviour such as cell-matrix interaction.

  6. Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

    Directory of Open Access Journals (Sweden)

    Maxi Meissner

    Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

  7. Ozone induces glucose intolerance and systemic metabolic effects in young and aged brown Norway rats

    Energy Technology Data Exchange (ETDEWEB)

    Bass, V. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Gordon, C.J.; Jarema, K.A.; MacPhail, R.C. [Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Cascio, W.E. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Phillips, P.M. [Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Ledbetter, A.D.; Schladweiler, M.C. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Andrews, D. [Research Cores Unit, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Miller, D. [Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC (United States); Doerfler, D.L. [Research Cores Unit, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Kodavanti, U.P., E-mail: kodavanti.urmila@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States)

    2013-12-15

    Air pollutants have been associated with increased diabetes in humans. We hypothesized that ozone would impair glucose homeostasis by altering insulin signaling and/or endoplasmic reticular (ER) stress in young and aged rats. One, 4, 12, and 24 month old Brown Norway (BN) rats were exposed to air or ozone, 0.25 or 1.0 ppm, 6 h/day for 2 days (acute) or 2 d/week for 13 weeks (subchronic). Additionally, 4 month old rats were exposed to air or 1.0 ppm ozone, 6 h/day for 1 or 2 days (time-course). Glucose tolerance tests (GTT) were performed immediately after exposure. Serum and tissue biomarkers were analyzed 18 h after final ozone for acute and subchronic studies, and immediately after each day of exposure in the time-course study. Age-related glucose intolerance and increases in metabolic biomarkers were apparent at baseline. Acute ozone caused hyperglycemia and glucose intolerance in rats of all ages. Ozone-induced glucose intolerance was reduced in rats exposed for 13 weeks. Acute, but not subchronic ozone increased α{sub 2}-macroglobulin, adiponectin and osteopontin. Time-course analysis indicated glucose intolerance at days 1 and 2 (2 > 1), and a recovery 18 h post ozone. Leptin increased day 1 and epinephrine at all times after ozone. Ozone tended to decrease phosphorylated insulin receptor substrate-1 in liver and adipose tissues. ER stress appeared to be the consequence of ozone induced acute metabolic impairment since transcriptional markers of ER stress increased only after 2 days of ozone. In conclusion, acute ozone exposure induces marked systemic metabolic impairments in BN rats of all ages, likely through sympathetic stimulation. - Highlights: • Air pollutants have been associated with increased diabetes in humans. • Acute ozone exposure produces profound metabolic alterations in rats. • Age influences metabolic risk factors in aging BN rats. • Acute metabolic effects are reversible and repeated exposure reduces these effects. • Ozone

  8. Glucose metabolism and neurogenesis in the gerbil hippocampus after transient forebrain ischemia

    Institute of Scientific and Technical Information of China (English)

    Dae Young Yoo; Kwon Young Lee; Joon Ha Park; Hyo Young Jung; Jong Whi Kim; Yeo Sung Yoon; Moo-Ho Won; Jung Hoon Choi; In Koo Hwang

    2016-01-01

    Recent evidence exists that glucose transporter 3 (GLUT3) plays an important role in the energy metabo-lism in the brain. Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and mRNA levels rather than tissue levels. In the present study, we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia. In the sham-operated group, GLUT3 immunoreactivity in the hippocampal CA1 region was weak, in the pyramidal cells of the CA1 region in-creased in a time-dependent fashion 24 hours after ischemia, and in the hippocampal CA1 region decreased signiifcantly between 2 and 5 days after ischemia, with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia. In a double immunolfuorescence study using GLUT3 and gli-al-ifbrillary acidic protein (GFAP), we observed strong GLUT3 immunoreactivity in the astrocytes. GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfu-sion. In a double immunolfuorescence study using GLUT3 and doublecortin (DCX), we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia. GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgran-ular zone of the dentate gyrus. These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus.

  9. Glucose metabolism and neurogenesis in the gerbil hippocampus after transient forebrain ischemia

    Science.gov (United States)

    Yoo, Dae Young; Lee, Kwon Young; Park, Joon Ha; Jung, Hyo Young; Kim, Jong Whi; Yoon, Yeo Sung; Won, Moo-Ho; Choi, Jung Hoon; Hwang, In Koo

    2016-01-01

    Recent evidence exists that glucose transporter 3 (GLUT3) plays an important role in the energy metabolism in the brain. Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and mRNA levels rather than tissue levels. In the present study, we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia. In the sham-operated group, GLUT3 immunoreactivity in the hippocampal CA1 region was weak, in the pyramidal cells of the CA1 region increased in a time-dependent fashion 24 hours after ischemia, and in the hippocampal CA1 region decreased significantly between 2 and 5 days after ischemia, with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia. In a double immunofluorescence study using GLUT3 and glial-fibrillary acidic protein (GFAP), we observed strong GLUT3 immunoreactivity in the astrocytes. GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfusion. In a double immunofluorescence study using GLUT3 and doublecortin (DCX), we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia. GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgranular zone of the dentate gyrus. These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus. PMID:27651772

  10. Lactate as a cerebral metabolic fuel for glucose-6-phosphatase deficient children.

    Science.gov (United States)

    Fernandes, J; Berger, R; Smit, G P

    1984-04-01

    The main substrates for brain energy metabolism were measured in blood samples taken from the carotid artery and the internal jugular bulb of four children with glycogen storage disease caused by deficiency of glucose-6-phosphatase. Multiple paired arterial and venous blood samples were analyzed for glucose, lactate, pyruvate, D-beta-hydroxybutyrate, acetoacetate, glycerol and O2, and the arteriovenous differences of the concentrations were calculated. In the first three patients the substrates were measured in two successive conditions with lower and higher glucose-intake, respectively, inducing reciprocally higher and lower concentrations of blood lactate. In the fourth patient medium chain triglycerides were administered simultaneously with the glucose-containing gastric drip feeding. Lactate appeared to be taken up significantly. It consumed, if completely oxidized, between 40-50% of the total O2 uptake in most cases. Only once in one patient the uptake of lactate switched to its release, when the blood lactate level decreased to normal. D-beta-hydroxybutyrate and acetoacetate arteriovenous (A-V) differences were small to negligible and these ketone bodies, therefore, did not contribute substantially to the brain's energy expenditure. Glycerol was not metabolized by the brain. Lactate thus appeared to be the second brain fuel next to glucose. It may protect the brain against fuel depletion in case of hypoglycemia.

  11. Epigallocatechin gallate affects glucose metabolism and increases fitness and lifespan in Drosophila melanogaster.

    Science.gov (United States)

    Wagner, Anika E; Piegholdt, Stefanie; Rabe, Doerte; Baenas, Nieves; Schloesser, Anke; Eggersdorfer, Manfred; Stocker, Achim; Rimbach, Gerald

    2015-10-13

    In this study, we tested whether a standardized epigallocatechin-3-gallate (EGCG) rich green tea extract (comprising > 90% EGCG) affects fitness and lifespan as well as parameters of glucose metabolism and energy homeostasis in the fruit fly, Drosophila melanogaster. Following the application of the green tea extract a significant increase in the mean lifespan (+ 3.3 days) and the 50% survival (+ 4.3 days) as well as improved fitness was detected. These effects went along an increased expression of Spargel, the homolog of mammalian PGC1α, which has been reported to affect lifespan in flies. Intriguingly, in flies, treatment with the green tea extract decreased glucose concentrations, which were accompanied by an inhibition of α-amylase and α-glucosidase activity. Computational docking analysis proved the potential of EGCG to dock into the substrate binding pocket of α-amylase and to a greater extent into α-glucosidase. Furthermore, we demonstrate that EGCG downregulates insulin-like peptide 5 and phosphoenolpyruvate carboxykinase, major regulators of glucose metabolism, as well as the Drosophila homolog of leptin, unpaired 2. We propose that a decrease in glucose metabolism in connection with an upregulated expression of Spargel contribute to the better fitness and the extended lifespan in EGCG-treated flies.

  12. Inhibition effects of ethanol on the kinetics of glucose metabolism by S. cerevisiae: NMR and modelling study

    Science.gov (United States)

    Ricci, Maso; Martini, Silvia; Bonechi, Claudia; Trabalzini, Lorenza; Santucci, Annalisa; Rossi, Claudio

    2004-04-01

    Saccharomyces cerevisiae is an important model to understand the eukaryotic cells control mechanisms. In this Letter, an approach based on in vivo13C NMR and mathematical modelling was presented to develop a basis for a deeper understanding of eukaryotic responses to environmental stresses. Despite the few metabolites included, the model describes correctly the dynamical behaviour of glucose degradation and ethanol production, providing a qualitative and quantitative description of the response of S. cerevisiae metabolism to stressful concentrations of ethanol. The data and the model highlight that an exogenous stress is able to influence the cellular activity and the ethanol production rate constant.

  13. Fructose Alters Intermediary Metabolism of Glucose in Human Adipocytes and Diverts Glucose to Serine Oxidation in the One-Carbon Cycle Energy Producing Pathway.

    Science.gov (United States)

    Varma, Vijayalakshmi; Boros, László G; Nolen, Greg T; Chang, Ching-Wei; Wabitsch, Martin; Beger, Richard D; Kaput, Jim

    2015-06-16

    Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS) preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration. Targeted tracer [1,2-13C2]-d-glucose fate association approach was employed to examine the influence of fructose on the intermediary metabolism of glucose. Increasing concentrations of fructose robustly increased the oxidation of [1,2-13C2]-d-glucose to 13CO2 (p < 0.000001). However, glucose-derived 13CO2 negatively correlated with 13C labeled glutamate, 13C palmitate, and M+1 labeled lactate. These are strong markers of limited tricarboxylic acid (TCA) cycle, fatty acid synthesis, pentose cycle fluxes, substrate turnover and NAD+/NADP+ or ATP production from glucose via complete oxidation, indicating diminished mitochondrial energy metabolism. Contrarily, a positive correlation was observed between glucose-derived 13CO2 formed and 13C oleate and doses of fructose which indicate the elongation and desaturation of palmitate to oleate for storage. Collectively, these results suggest that fructose preferentially drives glucose through serine oxidation glycine cleavage (SOGC pathway) one-carbon cycle for NAD+/NADP+ production that is utilized in fructose-induced lipogenesis and storage in adipocytes.

  14. Fructose Alters Intermediary Metabolism of Glucose in Human Adipocytes and Diverts Glucose to Serine Oxidation in the One–Carbon Cycle Energy Producing Pathway

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi Varma

    2015-06-01

    Full Text Available Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration. Targeted tracer [1,2-13C2]-d-glucose fate association approach was employed to examine the influence of fructose on the intermediary metabolism of glucose. Increasing concentrations of fructose robustly increased the oxidation of [1,2-13C2]-d-glucose to 13CO2 (p < 0.000001. However, glucose-derived 13CO2 negatively correlated with 13C labeled glutamate, 13C palmitate, and M+1 labeled lactate. These are strong markers of limited tricarboxylic acid (TCA cycle, fatty acid synthesis, pentose cycle fluxes, substrate turnover and NAD+/NADP+ or ATP production from glucose via complete oxidation, indicating diminished mitochondrial energy metabolism. Contrarily, a positive correlation was observed between glucose-derived 13CO2 formed and 13C oleate and doses of fructose which indicate the elongation and desaturation of palmitate to oleate for storage. Collectively, these results suggest that fructose preferentially drives glucose through serine oxidation glycine cleavage (SOGC pathway one-carbon cycle for NAD+/NADP+ production that is utilized in fructose-induced lipogenesis and storage in adipocytes.

  15. Abnormal Glucose Tolerance Is Associated with a Reduced Myocardial Metabolic Flexibility in Patients with Dilated Cardiomyopathy

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    Domenico Tricò

    2016-01-01

    Full Text Available Dilated cardiomyopathy (DCM is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. We verified whether this pattern is influenced by an abnormal glucose tolerance (AGT. In 10 patients with DCM, 5 with normal glucose tolerance (DCM-NGT and 5 with AGT (DCM-AGT, and 5 non-DCM subjects with AGT (N-AGT, we measured coronary blood flow and arteriovenous differences of oxygen and metabolites during Rest, Pacing (at 130 b/min, and Recovery. Myocardial lactate exchange and oleate oxidation were also measured. At Rest, DCM patients showed a reduced nonesterified fatty acids (NEFA myocardial uptake, while glucose utilization increased only in DCM-AGT. In response to Pacing, glucose uptake promptly rose in N-AGT (from 72 ± 21 to 234 ± 73 nmol/min/g, p<0.05, did not change in DCM-AGT, and slowly increased in DCM-NGT. DCM-AGT sustained the extra workload by increasing NEFA oxidation (from 1.3 ± 0.2 to 2.9 ± 0.1 μmol/min/gO2 equivalents, p<0.05, while DCM-NGT showed a delayed increase in glucose uptake. Substrate oxidation rates paralleled the metabolites data. The presence of AGT in patients with DCM exacerbates both the shift from fat to carbohydrates in resting myocardial metabolism and the reduced myocardial metabolic flexibility in response to an increased workload. This trial is registered with ClinicalTrial.gov NCT02440217.

  16. GLUCOSE AND LACTATE METABOLISM IN THE AWAKE AND STIMULATED RAT: A 13C-NMR STUDY.

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    Denys eSampol

    2013-05-01

    Full Text Available Glucose is the major energetic substrate for the brain but evidence has accumulated during the last 20 years that lactate produced by astrocytes could be an additional substrate for neurons. However, little information exists about this lactate shuttle in vivo in activated and awake animals. We designed an experiment in which the cortical barrel field (S1BF was unilaterally activated during infusion of both glucose and lactate (alternatively labeled with 13C in rats. At the end of stimulation (1h, both S1BF areas were removed and analyzed by HR-MAS NMR spectroscopy to compare glucose and lactate metabolism in the activated area versus the non-activated one. In combination with microwave irradiation, HR-MAS spectroscopy is a powerful technical approach to study brain lactate metabolism in vivo.Using in vivo 14C-2-deoxyglucose and autoradiography, we confirmed that whisker stimulation was effective since we observed a 40% increase in glucose uptake in the activated S1BF area compared to the ipsilateral one.We first determined that lactate observed on spectra of biopsies did not arise from post-mortem metabolism. 1H-NMR data indicated that during brain activation, there was an average 2.4-fold increase in lactate content in the activated area. When [1-13C]glucose+lactate were infused, 13C-NMR data showed an increase in 13C-labeled lactate during brain activation, as well as an increase in lactate C3-specific enrichment. This result demonstrates that the increase in lactate observed on 1H-NMR spectra originates from newly synthesized lactate from the labeled precursor ([1-13C]glucose. It also shows that this additional lactate does not arise from an increase in blood lactate uptake since it would otherwise be unlabeled. These results are in favor of intracerebral lactate production during brain activation in vivo, which could be a supplementary fuel for neurons.

  17. Myocardial glucose transporters and glycolytic metabolism during ischemia in hyperglycemic diabetic swine.

    Science.gov (United States)

    Stanley, W C; Hall, J L; Smith, K R; Cartee, G D; Hacker, T A; Wisneski, J A

    1994-01-01

    We assessed the effects of 4 weeks of streptozocin-induced diabetes on regional myocardial glycolytic metabolism during ischemia in anesthetized open-chest domestic swine. Diabetic animals were hyperglycemic (12.0 +/- 2.1 v 6.6 +/- .5 mmol/L), and had lower fasting insulin levels (27 +/- 8 v 79 +/- 19 pmol/L). Myocardial glycolytic metabolism was studied with coronary flow controlled by an extracorporeal perfusion circuit. Left anterior descending coronary artery (LAD) flow was decreased by 50% for 45 minutes and left circumflex (CFX) flow was constant. Myocardial glucose uptake and extraction were measured with D-[6-3H]-2-deoxyglucose (DG) and myocardial blood flow was measured with microspheres. The rate of glucose conversion to lactate and lactate uptake and output were assessed with a continuous infusion of [6-14C]glucose and [U-13C]lactate into the coronary perfusion circuit. Both diabetic and nondiabetic animals had sharp decreases in subendocardial blood flow during ischemia (from 1.21 +/- .10 to 0.43 +/- .08 mL.g-1.min-1 in the nondiabetic group, and from 1.30 +/- .15 to 0.55 +/- .11 in the diabetic group). Diabetes had no significant effect on myocardial glucose uptake or glucose conversion to lactate under either well-perfused or ischemic conditions. Forty-five minutes of ischemia resulted in significant glycogen depletion in the subendocardium in both nondiabetic and diabetic animals, with no differences between the two groups. Glycolytic metabolism is not impaired in hyperglycemic diabetic swine after 1 month of the disease when compared with that in normoglycemic nondiabetic animals. The myocardial content of the insulin-regulatable glucose transporter (GLUT 4) was measured in left ventricular biopsies.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Ovarian tumor-initiating cells display a flexible metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Angela S. [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Roberts, Paul C. [Biomedical Science and Pathobiology, Virginia Tech, Blacksburg, VA (United States); Frisard, Madlyn I. [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Hulver, Matthew W., E-mail: hulvermw@vt.edu [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Schmelz, Eva M., E-mail: eschmelz@vt.edu [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States)

    2014-10-15

    An altered metabolism during ovarian cancer progression allows for increased macromolecular synthesis and unrestrained growth. However, the metabolic phenotype of cancer stem or tumor-initiating cells, small tumor cell populations that are able to recapitulate the original tumor, has not been well characterized. In the present study, we compared the metabolic phenotype of the stem cell enriched cell variant, MOSE-L{sub FFLv} (TIC), derived from mouse ovarian surface epithelial (MOSE) cells, to their parental (MOSE-L) and benign precursor (MOSE-E) cells. TICs exhibit a decrease in glucose and fatty acid oxidation with a concomitant increase in lactate secretion. In contrast to MOSE-L cells, TICs can increase their rate of glycolysis to overcome the inhibition of ATP synthase by oligomycin and can increase their oxygen consumption rate to maintain proton motive force when uncoupled, similar to the benign MOSE-E cells. TICs have an increased survival rate under limiting conditions as well as an increased survival rate when treated with AICAR, but exhibit a higher sensitivity to metformin than MOSE-E and MOSE-L cells. Together, our data show that TICs have a distinct metabolic profile that may render them flexible to adapt to the specific conditions of their microenvironment. By better understanding their metabolic phenotype and external environmental conditions that support their survival, treatment interventions can be designed to extend current therapy regimens to eradicate TICs. - Highlights: • Ovarian cancer TICs exhibit a decreased glucose and fatty acid oxidation. • TICs are more glycolytic and have highly active mitochondria. • TICs are more resistant to AICAR but not metformin. • A flexible metabolism allows TICs to adapt to their microenvironment. • This flexibility requires development of specific drugs targeting TIC-specific changes to prevent recurrent TIC outgrowth.

  19. Diabetes, Glucose Metabolism, and Glaucoma: The 2005–2008 National Health and Nutrition Examination Survey

    Science.gov (United States)

    Zhao, Di; Cho, Juhee; Kim, Myung Hun; Friedman, David; Guallar, Eliseo

    2014-01-01

    Background Diabetes may affect vascular autoregulation of the retina and optic nerve and may be associated with an increased risk of glaucoma,but the association of prediabetes, insulin resistance, markers of glucose metabolismwith glaucoma has not beenevaluated in general population samples. Objective To examine the relation between diabetes, pre-diabetes, metabolic syndrome and its components and the levels of fasting glucose, HbA1c and HOMA-IR with the prevalence of glaucoma in the general U.S. population. Methods Cross-sectional study of 3,299 adult men and women from the 2005–2008 National Health and NutritionExamination Survey (NHANES). The presence of diabetes, prediabetes, the metabolic syndrome and its individual components and biomarkers of glucose metabolisms were based on standardized questionnaire and physical exam data and laboratory tests. The history of glaucoma was assessed through questionnaire during the home interview. Results Diabetes was strongly associated with prevalent glaucoma.In fully adjusted models, the odds ratiofor glaucoma comparing participants with diabetes with participants in the reference group with neither pre-diabetes nor diabetes was 2.12 (95% CI: 1.23, 3.67). The corresponding odd ratio comparing participants with pre-diabetes to those in the reference group was 1.01 (95% CI: 0.57, 1.82). Patients with 5 or more years of diabetes duration hadan OR for glaucoma of 3.90 (95% CI: 1.63, 9.32) compared with patients with <5 years of diabetes duration. We also found a hockey-stick shaped associations between biomarkers of glucose metabolisms and the prevalence of glaucoma. Conclusions Diabetes was associated with higher risk of glaucoma. Participants without diabetes but at the higher levels of fasting glucose, fasting insulin, HbA1c and HOMA-IR spectrum may also be at greater risk of glaucoma. PMID:25393836

  20. Effect of peripheral 5-HT on glucose and lipid metabolism in wether sheep.

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    Hitoshi Watanabe

    Full Text Available In mice, peripheral 5-HT induces an increase in the plasma concentrations of glucose, insulin and bile acids, and a decrease in plasma triglyceride, NEFA and cholesterol concentrations. However, given the unique characteristics of the metabolism of ruminants relative to monogastric animals, the physiological role of peripheral 5-HT on glucose and lipid metabolism in sheep remains to be established. Therefore, in this study, we investigated the effect of 5-HT on the circulating concentrations of metabolites and insulin using five 5-HT receptor (5HTR antagonists in sheep. After fasting for 24 h, sheep were intravenously injected with 5-HT, following which-, plasma glucose, insulin, triglyceride and NEFA concentrations were significantly elevated. In contrast, 5-HT did not affect the plasma cholesterol concentration, and it induced a decrease in bile acid concentrations. Increases in plasma glucose and insulin concentrations induced by 5-HT were attenuated by pre-treatment with Methysergide, a 5HTR 1, 2 and 7 antagonist. Additionally, decreased plasma bile acid concentrations induced by 5-HT were blocked by pre-treatment with Ketanserin, a 5HTR 2A antagonist. However, none of the 5HTR antagonists inhibited the increase in plasma triglyceride and NEFA levels induced by 5-HT. On the other hand, mRNA expressions of 5HTR1D and 1E were observed in the liver, pancreas and skeletal muscle. These results suggest that there are a number of differences in the physiological functions of peripheral 5-HT with respect to lipid metabolism between mice and sheep, though its effect on glucose metabolism appears to be similar between these species.

  1. Diabetes, glucose metabolism, and glaucoma: the 2005-2008 National Health and Nutrition Examination Survey.

    Directory of Open Access Journals (Sweden)

    Di Zhao

    Full Text Available BACKGROUND: Diabetes may affect vascular autoregulation of the retina and optic nerve and may be associated with an increased risk of glaucoma,but the association of prediabetes, insulin resistance, markers of glucose metabolismwith glaucoma has not beenevaluated in general population samples. OBJECTIVE: To examine the relation between diabetes, pre-diabetes, metabolic syndrome and its components and the levels of fasting glucose, HbA1c and HOMA-IR with the prevalence of glaucoma in the general U.S. population. METHODS: Cross-sectional study of 3,299 adult men and women from the 2005-2008 National Health and NutritionExamination Survey (NHANES. The presence of diabetes, prediabetes, the metabolic syndrome and its individual components and biomarkers of glucose metabolisms were based on standardized questionnaire and physical exam data and laboratory tests. The history of glaucoma was assessed through questionnaire during the home interview. RESULTS: Diabetes was strongly associated with prevalent glaucoma.In fully adjusted models, the odds ratiofor glaucoma comparing participants with diabetes with participants in the reference group with neither pre-diabetes nor diabetes was 2.12 (95% CI: 1.23, 3.67. The corresponding odd ratio comparing participants with pre-diabetes to those in the reference group was 1.01 (95% CI: 0.57, 1.82. Patients with 5 or more years of diabetes duration hadan OR for glaucoma of 3.90 (95% CI: 1.63, 9.32 compared with patients with <5 years of diabetes duration. We also found a hockey-stick shaped associations between biomarkers of glucose metabolisms and the prevalence of glaucoma. CONCLUSIONS: Diabetes was associated with higher risk of glaucoma. Participants without diabetes but at the higher levels of fasting glucose, fasting insulin, HbA1c and HOMA-IR spectrum may also be at greater risk of glaucoma.

  2. Plasma antioxidants and brain glucose metabolism in elderly subjects with cognitive complaints

    Energy Technology Data Exchange (ETDEWEB)

    Picco, Agnese; Ferrara, Michela; Arnaldi, Dario; Brugnolo, Andrea; Nobili, Flavio [University of Genoa and IRCCS San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Largo P. Daneo, 3, 16132, Genoa (Italy); Polidori, M.C. [University of Cologne, Institute of Geriatrics, Cologne (Germany); Cecchetti, Roberta; Baglioni, Mauro; Bastiani, Patrizia; Mecocci, Patrizia [University of Perugia, Institute of Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, Perugia (Italy); Morbelli, Silvia; Bossert, Irene [University of Genoa and IRCCS San Martino-IST, Nuclear Medicine, Department of Health Science (DISSAL), Genoa (Italy); Fiorucci, Giuliana; Dottorini, Massimo Eugenio [Nuclear Medicine, S. M. della Misericordia Hospital, Perugia (Italy)

    2014-04-15

    The role of oxidative stress is increasingly recognized in cognitive disorders of the elderly, notably Alzheimer's disease (AD). In these subjects brain{sup 18}F-FDG PET is regarded as a reliable biomarker of neurodegeneration. We hypothesized that oxidative stress could play a role in impairing brain glucose utilization in elderly subjects with increasing severity of cognitive disturbance. The study group comprised 85 subjects with cognitive disturbance of increasing degrees of severity including 23 subjects with subjective cognitive impairment (SCI), 28 patients with mild cognitive impairment and 34 patients with mild AD. In all subjects brain FDG PET was performed and plasma activities of extracellular superoxide dismutase (eSOD), catalase and glutathione peroxidase were measured. Voxel-based analysis (SPM8) was used to compare FDG PET between groups and to evaluate correlations between plasma antioxidants and glucose metabolism in the whole group of subjects, correcting for age and Mini-Mental State Examination score. Brain glucose metabolism progressively decreased in the bilateral posterior temporoparietal and cingulate cortices across the three groups, from SCI to mild AD. eSOD activity was positively correlated with glucose metabolism in a large area of the left temporal lobe including the superior, middle and inferior temporal gyri and the fusiform gyrus. These results suggest a role of oxidative stress in the impairment of glucose utilization in the left temporal lobe structures in elderly patients with cognitive abnormalities, including AD and conditions predisposing to AD. Further studies exploring the oxidative stress-energy metabolism axis are considered worthwhile in larger groups of these patients in order to identify pivotal pathophysiological mechanisms and innovative therapeutic opportunities. (orig.)

  3. Effect and its Mechanism of dexamethasone and pioglitazone intervention on glucose metabolism in HepG2 cells%地塞米松影响肝细胞糖代谢机制及吡格列酮干预作用的研究

    Institute of Scientific and Technical Information of China (English)

    王丹萍; 邵明玮; 宋素彩; 汪丽娟; 栗夏连

    2013-01-01

    目的 研究地塞米松(DEX)在细胞水平对肝脏糖代谢和胰岛素的生物效应的影响,并观察吡格列酮(PGZ)在该过程中的干预作用. 方法 体外培养HepG2细胞,加入DEX作用不同的时间,GOD-POD法测上清葡萄糖浓度来确定影响细胞葡萄糖消耗量(GC)最明显的DEX作用时间,并观察PGZ在该条件下对细胞GC、糖原合成、糖异生及糖酵解过程的干预作用. 结果 1μmol/L DEX作用36 h时细胞GC下降最明显,作用48 h时出现IR.PGZ组细胞糖原合成、糖异生指标较DEX组差异均有统计学意义(P均<0.05),糖酵解指标差异无统计学意义(P>0.05),但在胰岛素存在时,PGZ和胰岛素在促进葡萄糖合成和酵解、抑制糖异生等糖代谢的各个环节均发挥协同作用(P<0.05). 结论 DEX作用于肝细胞使其葡萄糖摄取能力及IS下降.PGZ通过糖代谢的多种途径发挥干预作用,其中主要通过糖原合成和糖异生,为临床上类固醇性糖尿病的治疗提供了分子基础.%Objective To study the effect of dexamethasone on glucose metabolism and insulin sensitivity in HepG2 cells, and observe the intervention of pioglitazone on it Methods Dexamethasone was added into the cultured HepG2 cells for different culture duration, and the GOD-POD method was used to ascertain the best action time of dexamethasone for the most obvious effect on glucose metabolism of HepG2 cells. Based on this, the intervention effect of pioglitazone through measuring the indicators of glucose consumption (GC), glycogen synthesis, gluconeogenesis, and glycolysis was observed. Results With the intervention of 1 μmol/L dexamethasone for 36 hours, the decrease of GC of cells was the most significant, and IR occurred at 48 hours. The glycogen synthesis and gluconeogenesis of the PGZ group were significantly different from those of the dexamethasone group (all P0. 05). Insulin and pioglitazone had the co-effect on promoting glucose synthesis, glycolysis, and

  4. Cereal Processing Influences Postprandial Glucose Metabolism as Well as the GI Effect

    OpenAIRE

    2015-01-01

    Objective: Technological processes may influence the release of glucose in starch. The aim of this study was to compare the metabolic response and the kinetics of appearance of exogenous glucose from 2 cereal products consumed at breakfast. Methods: Twenty-five healthy men were submitted to a randomized, open, crossover study that was divided into 2 parts: 12 of the 25 subjects were included in the “isotope part,” and the 13 other subjects were included in the “glycemic part.” On test days, s...

  5. Effect of abomasal glucose infusion on splanchnic amino acid metabolism in periparturient dairy cows

    DEFF Research Database (Denmark)

    Larsen, Mogens; Kristensen, Niels Bastian

    2009-01-01

    Six Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the portal vein, hepatic vein, mesenteric vein, and an artery were used to study the effects of abomasal glucose infusion on splanchnic AA metabolism. The experimental design was a split plot, with cow as the whole...... plot, treatment as the whole-plot factor and days in milk (DIM) as the subplot factor. Cows were assigned to 1 of 2 treatments: control or infusion of 1,500 g/d of glucose into the abomasum from the day of calving to 29 DIM....

  6. Toward homosuccinate fermentation: metabolic engineering of Corynebacterium glutamicum for anaerobic production of succinate from glucose and formate.

    Science.gov (United States)

    Litsanov, Boris; Brocker, Melanie; Bott, Michael

    2012-05-01

    Previous studies have demonstrated the capability of Corynebacterium glutamicum for anaerobic succinate production from glucose under nongrowing conditions. In this work, we have addressed two shortfalls of this process, the formation of significant amounts of by-products and the limitation of the yield by the redox balance. To eliminate acetate formation, a derivative of the type strain ATCC 13032 (strain BOL-1), which lacked all known pathways for acetate and lactate synthesis (Δcat Δpqo Δpta-ackA ΔldhA), was constructed. Chromosomal integration of the pyruvate carboxylase gene pyc(P458S) into BOL-1 resulted in strain BOL-2, which catalyzed fast succinate production from glucose with a yield of 1 mol/mol and showed only little acetate formation. In order to provide additional reducing equivalents derived from the cosubstrate formate, the fdh gene from Mycobacterium vaccae, coding for an NAD(+)-coupled formate dehydrogenase (FDH), was chromosomally integrated into BOL-2, leading to strain BOL-3. In an anaerobic batch process with strain BOL-3, a 20% higher succinate yield from glucose was obtained in the presence of formate. A temporary metabolic blockage of strain BOL-3 was prevented by plasmid-borne overexpression of the glyceraldehyde 3-phosphate dehydrogenase gene gapA. In an anaerobic fed-batch process with glucose and formate, strain BOL-3/pAN6-gap accumulated 1,134 mM succinate in 53 h with an average succinate production rate of 1.59 mmol per g cells (dry weight) (cdw) per h. The succinate yield of 1.67 mol/mol glucose is one of the highest currently described for anaerobic succinate producers and was accompanied by a very low level of by-products (0.10 mol/mol glucose).

  7. TAp63 is a master transcriptional regulator of lipid and glucose metabolism

    Science.gov (United States)

    Su, Xiaohua; Gi, Young Jin; Chakravarti, Deepavali; Chan, Io Long; Zhang, Aijun; Xia, Xuefeng; Tsai, Kenneth Y.; Flores, Elsa R.

    2012-01-01

    SUMMARY TAp63 prevents premature aging suggesting a link to genes that regulate longevity. Further characterization of TAp63−/− mice revealed that these mice develop obesity, insulin resistance, and glucose intolerance, similar to those seen in mice lacking two key metabolic regulators, Silent information regulator T1 (Sirt1) and AMPK. While the roles of Sirt1 and AMPK in metabolism have been well studied, their upstream regulators are not well understood. We found that TAp63 is important in regulating energy metabolism by accumulating in response to metabolic stress and transcriptionally activating Sirt1, AMPKα2, and LKB1 resulting in increased fatty acid synthesis and decreased fatty acid oxidation. Moreover, we found that TAp63 lowers blood glucose levels in response to metformin. Restoration of Sirt1, AMPKα2, and LKB1 in TAp63−/− mice rescued some of the metabolic defects of the TAp63−/− mice. Our study defines a role for TAp63 in metabolism and weight control. PMID:23040072

  8. Interactions between mitochondrial reactive oxygen species and cellular glucose metabolism

    NARCIS (Netherlands)

    Liemburg-Apers, D.C.; Willems, P.H.G.M.; Koopman, W.J.H.; Grefte, Sander

    2015-01-01

    Mitochondrial reactive oxygen species (ROS) production and detoxification are tightly balanced. Shifting this balance enables ROS to activate intracellular signaling and/or induce cellular damage and cell death. Increased mitochondrial ROS production is observed in a number of pathological condit

  9. Visceral adiposity influences glucose and glycogen metabolism in control and hyperlipidic-fed animals

    Directory of Open Access Journals (Sweden)

    Danielle Kaiser de Souza

    2013-04-01

    Full Text Available Introduction: Evidences suggest that fat intake, visceral obesity and intracellular lipids are related to insulin impairment. Objective: The objective of the present paper was correlate visceral obesity and metabolic alterations in control (CTR and hyperlipidic cafeteria diet (CFT fed animals. Methods: After 6 months of diet treatment, liver and muscle of the male rats were utilized to determined glucose uptake and glycogen metabolism after administration of 0.4I U/kg insulin in vivo, and correlate the visceral adiposity to these two parameters. Results: Ample range of physiologic answers to body composition in metabolic profile of the both diets was found. No differences were found in glycemia and triacylglycerol after insulin action in both groups, however CFT group accumulated higher adiposity, mostly visceral fat, and showed lower glycogen content in the liver. We also found an inverse correlation between visceral adiposity and glucose uptake and a decrease of the glycogen synthase active form in the liver. CTR animals demonstrated an inverse correlation between glucose uptake and visceral adiposity in the muscle. Discussion and conclusion: It was observed a variability of metabolic alterations in animals which can be related to degree of accumulation of abdominal adiposity and ingestion of diet fats. Further studies will be required to clarify the reasons for the observed liver alterations in CFT and muscle alterations in CTR animals.

  10. Metabolic Characteristics of a Glucose-Utilizing Shewanella oneidensis Strain Grown under Electrode-Respiring Conditions.

    Directory of Open Access Journals (Sweden)

    Gen Nakagawa

    Full Text Available In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode, the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.

  11. Dynamic metabolic flux analysis of plant cell wall synthesis.

    Science.gov (United States)

    Chen, Xuewen; Alonso, Ana P; Shachar-Hill, Yair

    2013-07-01

    The regulation of plant cell wall synthesis pathways remains poorly understood. This has become a bottleneck in designing bioenergy crops. The goal of this study was to analyze the regulation of plant cell wall precursor metabolism using metabolic flux analysis based on dynamic labeling experiments. Arabidopsis T87 cells were cultured heterotrophically with (13)C labeled sucrose. The time course of ¹³C labeling patterns in cell wall precursors and related sugar phosphates was monitored using liquid chromatography tandem mass spectrometry until steady state labeling was reached. A kinetic model based on mass action reaction mechanisms was developed to simulate the carbon flow in the cell wall synthesis network. The kinetic parameters of the model were determined by fitting the model to the labeling time course data, cell wall composition, and synthesis rates. A metabolic control analysis was performed to predict metabolic regulations that may improve plant biomass composition for biofuel production. Our results describe the routes and rates of carbon flow from sucrose to cell wall precursors. We found that sucrose invertase is responsible for the entry of sucrose into metabolism and UDP-glucose-4-epimerase plays a dominant role in UDP-Gal synthesis in heterotrophic Aradidopsis cells under aerobic conditions. We also predicted reactions that exert strong regulatory influence over carbon flow to cell wall synthesis and its composition.

  12. Saffron (Crocus sativus L.) increases glucose uptake and insulin sensitivity in muscle cells via multipathway mechanisms.

    Science.gov (United States)

    Kang, Changkeun; Lee, Hyunkyoung; Jung, Eun-Sun; Seyedian, Ramin; Jo, MiNa; Kim, Jehein; Kim, Jong-Shu; Kim, Euikyung

    2012-12-15

    Saffron (Crocus sativus Linn.) has been an important subject of research in the past two decades because of its various biological properties, including anti-cancer, anti-inflammatory, and anti-atherosclerotic activities. On the other hand, the molecular bases of its actions have been scarcely understood. Here, we elucidated the mechanism of the hypoglycemic actions of saffron through investigating its signaling pathways associated with glucose metabolism in C(2)C(12) skeletal muscle cells. Saffron strongly enhanced glucose uptake and the phosphorylation of AMPK (AMP-activated protein kinase)/ACC (acetyl-CoA carboxylase) and MAPKs (mitogen-activated protein kinases), but not PI 3-kinase (Phosphatidylinositol 3-kinase)/Akt. Interestingly, the co-treatment of saffron and insulin further improved the insulin sensitivity via both insulin-independent (AMPK/ACC and MAPKs) and insulin-dependent (PI 3-kinase/Akt and mTOR) pathways. It also suggested that there is a crosstalk between the two signaling pathways of glucose metabolism in skeletal muscle cells. These results could be confirmed from the findings of GLUT4 translocation. Taken together, AMPK plays a major role in the effects of saffron on glucose uptake and insulin sensitivity in skeletal muscle cells. Our study provides important insights for the possible mechanism of action of saffron and its potential as a therapeutic agent in diabetic patients.

  13. Metabolic responses to exercise on land and in water following glucose ingestion.

    Science.gov (United States)

    Kurobe, Kazumichi; Kousaka, Ayaka; Ogita, Futoshi; Matsumoto, Naoyuki

    2016-12-26

    Although aerobic exercise after a meal decreases postprandial blood glucose, the differences in glucose response between land and aquatic exercise are unclear. Thus, we examined the effect of different modes of exercise with same energy expenditure following glucose ingestion on carbohydrate metabolism. Ten healthy sedentary men (age, 22 ± 1 years) participated in this study. All subjects performed each of three exercise modes (cycling, walking and aquatic exercise) for 30 min after ingestion of a 75-g glucose solution with 1-2 weeks between trials. The exercise intensity was set at 40% of the maximum oxygen uptake that occurred during cycling. The velocity during walking and the target heart rate during aquatic exercise were predetermined in a pretest. The plasma glucose concentration at 30 min after exercise was significantly lower with aquatic exercise compared to that with cycling and walking (Pexercise modes in respiratory exchange ratio. On the other hand, serum free fatty acid concentration with aquatic exercise was significantly higher at 120 min after exercise compared with that after walking (Pexercise reduces postprandial blood glucose compared with both cycling and walking with the same energy expenditure. Aquatic exercise shows potential as an exercise prescription to prevent postprandial hyperglycaemia.

  14. Cross feeding of glucose metabolism byproducts of Escherichia coli human gut isolates and probiotic strains affect survival of Vibrio cholerae.

    Science.gov (United States)

    Sengupta, Chirantana; Ekka, Manjula; Arora, Saurabh; Dhaware, Prashant D; Chowdhury, Rukhsana; Raychaudhuri, Saumya

    2017-01-01

    Vibrio cholerae converts glucose into either acid or the neutral end product acetoin and its survival in carbohydrate enriched media is linked to the nature of the byproducts produced. It has been demonstrated in this study that Escherichia coli strain isolated from the gut of healthy human volunteers and the commonly used probiotic E. coli Nissle strain that metabolize glucose to acidic byproducts drastically reduce the survival of V. cholerae strains irrespective of their glucose sensitivity and acetoin production status. Accordingly, E. coli glucose transport mutants that produce lower amounts of acidic metabolites had little effect on the survival of V. cholerae in cocultures. Thus, cross feeding of byproducts of glucose metabolism by heterologous bacteria modulates the survival of V. cholerae in glucose rich medium suggesting that composition of the gut microbiota could influence the outcome of V. cholerae infection especially when glucose based ORS is administered.

  15. Integrative Genomics Outlines a Biphasic Glucose Response and a ChREBP-RORγ Axis Regulating Proliferation in β Cells

    DEFF Research Database (Denmark)

    Schmidt, Søren Fisker; Madsen, Jesper Grud Skat; Frafjord, Kari Østerli

    2016-01-01

    activity in response to glucose in the INS-1E pancreatic β cell line. Our data outline a biphasic response with a first transcriptional wave during which metabolic genes are activated, and a second wave where cell-cycle genes are activated and β cell identity genes are repressed. The glucose......Glucose is an important inducer of insulin secretion, but it also stimulates long-term adaptive changes in gene expression that can either promote or antagonize the proliferative potential and function of β cells. Here, we have generated time-resolved profiles of enhancer and transcriptional...... regulators of the second wave. These include RORγ, the activity of which is important for glucose-induced proliferation of both INS-1E and primary rat β cells....

  16. Metabolic and endocrine modulation of anabolic and catabolic pathways of glucose and fatty acids. I. Chemical anatomy of the major metabolic pathways of the energogenic general function.

    Science.gov (United States)

    Belloiu, D D; Belloiu, I

    1986-01-01

    This study is an attempt to integrate the intermediary metabolism of energogenic substrates--glucose and fatty acids--within the framework of the energogenic general function (EGF), which is active in two distinct phases: anabolic and catabolic. EGF is a component of the metabolic general function (MGF), which together with the reproductive general function and the adaptation general function may be taken to represent three main "general functions of organisms" common to all beings, whether animal or vegetal. This initial paper presents, descriptively and graphically, the main anabolic functions and pathways of glucose and fatty acids and, separately, the main catabolic ones, in other words, the "chemical anatomy" of EGF. The study begins with the anabolic "digestive" function of the digestive tract, concerning the digestion and absorption of carbohydrates and proteins. Conversion of the non-absorbable macromolecules of ingested carbohydrates into absorbable micromolecules of glucose, is shown to enable the latter, after absorption, to carry out the two characteristic anabolic processes: transmembrane "transport" and "condensation". Absorption and vehiculation of hydrophobic lipids is carried out by means of the major function of intestinal cells: synthesis of chylomicrons. Chylomicrons are hydrophilic special lipoprotein particles which are able to transport fats to the adipose tissue and cholesterol to the liver. In the liver the anabolic aspects of EGF are represented by two main functions: glycogeno-genesis, i.e. "non-reductive" condensation of glucose into glycogen stores, and lipoproteino-genesis, i.e. "reductive" condensation of glucose into lipoproteins or VLDL (very low density lipoproteins). VLDL are hydrophilic (vehiculable) spheric particles (containing triacylglycerols and cholesteryl esters in their core, and phospholipids, cholesterol and apolipoprotein-B at their surface), which are to be released into the general circulation. The anabolic phase in

  17. Inhibition of glucose turnover by 3-bromopyruvate counteracts pancreatic cancer stem cell features and sensitizes cells to gemcitabine.

    Science.gov (United States)

    Isayev, Orkhan; Rausch, Vanessa; Bauer, Nathalie; Liu, Li; Fan, Pei; Zhang, Yiyao; Gladkich, Jury; Nwaeburu, Clifford C; Mattern, Jürgen; Mollenhauer, Martin; Rückert, Felix; Zach, Sebastian; Haberkorn, Uwe; Gross, Wolfgang; Schönsiegel, Frank; Bazhin, Alexandr V; Herr, Ingrid

    2014-07-15

    According to the cancer stem cell (CSC) hypothesis, the aggressive growth and early metastasis of pancreatic ductal adenocarcinoma (PDA) is due to the activity of CSCs, which are not targeted by current therapies. Otto Warburg suggested that the growth of cancer cells is driven by a high glucose metabolism. Here, we investigated whether glycolysis inhibition targets CSCs and thus may enhance therapeutic efficacy. Four established and 3 primary PDA cell lines, non-malignant cells, and 3 patient-tumor-derived CSC-enriched spheroidal cultures were analyzed by glucose turnover measurements, MTT and ATP assays, flow cytometry of ALDH1 activity and annexin positivity, colony and spheroid formation, western blotting, electrophoretic mobility shift assay, xenotransplantation, and immunohistochemistry. The effect of siRNA-mediated inhibition of LDH-A and LDH-B was also investigated. The PDA cells exhibited a high glucose metabolism, and glucose withdrawal or LDH inhibition by siRNA prevented growth and colony formation. Treatment with the anti-glycolytic agent 3-bromopyruvate almost completely blocked cell viability, self-renewal potential, NF-κB binding activity, and stem cell-related signaling and reverted gemcitabine resistance. 3-bromopyruvate was less effective in weakly malignant PDA cells and did not affect non-malignant cells, predicting minimal side effects. 3-bromopyruvate inhibited in vivo tumor engraftment and growth on chicken eggs and mice and enhanced the efficacy of gemcitabine by influencing the expression of markers of proliferation, apoptosis, self-renewal, and metastasis. Most importantly, primary CSC-enriched spheroidal cultures were eliminated by 3-bromopyruvate. These findings propose that CSCs may be specifically dependent on a high glucose turnover and suggest 3-bromopyruvate for therapeutic intervention.

  18. High glucose augments stress-induced apoptosis in endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Wenwen Zhong; Yang Liu; Hui Tian

    2009-01-01

    Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. Eahy 926 endothelial cells were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide (H2O2) or tumour necrosis factor- α (TNF- α ), following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of Eahy 926 cells to apoptosis in the presence of 500 μmol/L H2O2, above that induced in normal glucose (P<0.02). A reduction of H2O2- and TNF- α -induced apoptosis occurred in both high and low glucose after treatment with dexametha-sone (P<0.05). Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

  19. Expression of conventional and novel glucose transporters, GLUT1, -9, -10, and -12, in vascular smooth muscle cells

    OpenAIRE

    Pyla, Rajkumar; Poulose, Ninu; Jun, John Y.; Segar, Lakshman

    2013-01-01

    Intimal hyperplasia is characterized by exaggerated proliferation of vascular smooth muscle cells (VSMCs). Enhanced VSMC growth is dependent on increased glucose uptake and metabolism. Facilitative glucose transporters (GLUTs) are comprised of conventional GLUT isoforms (GLUT1–5) and novel GLUT isoforms (GLUT6–14). Previous studies demonstrate that GLUT1 overexpression or GLUT10 downregulation contribute to phenotypic changes in VSMCs. To date, the expression profile of all 14 GLUT isoforms h...

  20. High incidence of abnormal glucose metabolism in acute coronary syndrome patients at a moderate altitude: A sub-Himalayan study

    Science.gov (United States)

    Mokta, Jitender; Kumar, Subash; Ganju, Neeraj; Mokta, Kiran; Panda, Prashant Kumar; Gupta, Swatantra

    2017-01-01

    Background: Abnormal glucose metabolic status at admission is an important marker of future cardiovascular events and long-term mortality after acute coronary syndrome (ACS), whether or not they are known diabetics. Objective: The aims were to study the prevalence of abnormal glucose metabolism in ACS patients and to compare the different methods of diagnosing diabetes in ACS patients. Methods: We did a prospective study. About 250 consecutive nondiabetic patients (200 men and 50 women) with ACS admitted to a tertiary care institute of Himachal Pradesh in 1 year were enrolled. Admission plasma glucose, next morning fasting plasma glucose (FPG), A1C, and a standardized 75-g oral glucose tolerance test (OGTT) 72 h after admission were done. Glucose metabolism was categorized as normal glucose metabolism, impaired glucose metabolism (impaired fasting glucose or impaired glucose tolerance [IGT]), and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HBA1c ≥6.5%) or possibly stress diabetes (HBA1c <6.5%). A repeat OGTT after 3 months in objects with IGT and stress hyperglycemia at a time of admission was done. Results: The mean age was 54 ± 12.46 years. The mean plasma glucose at admission was 124 ± 53.96 mg/dL, and the mean FPG was 102 ± 27.07 mg/dL. The mean 2-h postglucose load concentration was 159.5 ± 56.58 mg/dL. At baseline, 95 (38%) had normal glucose metabolism, 95 (38%) had impaired glucose metabolism (IGT and or IGT) and 60 (24%) had diabetes; 48 (19.2%) were undiagnosed diabetes and 12 (4.8%) had stress hyperglycemia. At follow up 58.66% and 55.55% of patients with impaired glucose tolerance and stress hyperglycemia continued to have impaired glucose tolerance respectively. About 75 gm OGTT has highest sensitivity and specificity to diagnose diabetes, whereas A1C most specific to rule out stress hyperglycemia. Conclusions: In this small hilly state of India, abnormal glucose metabolism (previously undiagnosed diabetes and IGT) is

  1. Simultaneous Voltammetric Measurements of Glucose and Dopamine Demonstrate the Coupling of Glucose Availability with Increased Metabolic Demand in the Rat Striatum.

    Science.gov (United States)

    Smith, Samantha K; Lee, Christie A; Dausch, Matthew E; Horman, Brian M; Patisaul, Heather B; McCarty, Gregory S; Sombers, Leslie A

    2017-02-15

    Cerebral blood flow ensures delivery of nutrients, such as glucose, to brain sites with increased metabolic demand. However, little is known about rapid glucose dynamics at discrete locations during neuronal activation in vivo. Acute exposure to many substances of abuse elicits dopamine release and neuronal activation in the striatum; however, the concomitant changes in striatal glucose remain largely unknown. Recent developments have combined fast-scan cyclic voltammetry with glucose oxidase enzyme modified carbon-fiber microelectrodes to enable the measurement of glucose dynamics with subsecond temporal resolution in the mammalian brain. This work evaluates several waveforms to enable the first simultaneous detection of endogenous glucose and dopamine at single recording sites. These molecules, one electroactive and one nonelectroactive, were found to fluctuate in the dorsal striatum in response to electrical stimulation of the midbrain and systemic infusion of cocaine/raclopride. The data reveal the second-by-second dynamics of these species in a striatal microenvironment, and directly demonstrate the coupling of glucose availability with increased metabolic demand. This work provides a foundation that will enable detailed investigation of local mechanisms that regulate the coupling of cerebral blood flow with metabolic demand under normal conditions, and in animal studies of drug abuse and addiction.

  2. Pancreatic GLP-1 receptor activation is sufficient for incretin control of glucose metabolism in mice

    OpenAIRE

    Lamont, Benjamin J.; Li, Yazhou; Kwan, Edwin; Brown, Theodore J.; Gaisano, Herbert; Drucker, Daniel J.

    2011-01-01

    Glucagon-like peptide-1 (GLP-1) circulates at low levels and acts as an incretin hormone, potentiating glucose-dependent insulin secretion from islet β cells. GLP-1 also modulates gastric emptying and engages neural circuits in the portal region and CNS that contribute to GLP-1 receptor–dependent (GLP-1R–dependent) regulation of glucose homeostasis. To elucidate the importance of pancreatic GLP-1R signaling for glucose homeostasis, we generated transgenic mice that expressed the human GLP-1R ...

  3. Metabolic profiling of hematopoietic stem and progenitor cells during proliferation and differentiation into red blood cells.

    Science.gov (United States)

    Daud, Hasbullah; Browne, Susan; Al-Majmaie, Rasoul; Murphy, William; Al-Rubeai, Mohamed

    2016-01-25

    An understanding of the metabolic profile of cell proliferation and differentiation should support the optimization of culture conditions for hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and maturation into red blood cells. We have evaluated the key metabolic parameters during each phase of HSPC culture for red blood cell production in serum-supplemented (SS) and serum-free (SF) conditions. A simultaneous decrease in growth rate, total protein content, cell size, and the percentage of cells in the S/G2 phase of cell cycle, as well as an increase in the percentage of cells with a CD71(-)/GpA(+) surface marker profile, indicates HSPC differentiation into red blood cells. Compared with proliferating HSPCs, differentiating HSPCs showed significantly lower glucose and glutamine consumption rates, lactate and ammonia production rates, and amino acid consumption and production rates in both SS and SF conditions. Furthermore, extracellular acidification was associated with late proliferation phase, suggesting a reduced cellular metabolic rate during the transition from proliferation to differentiation. Under both SS and SF conditions, cells demonstrated a high metabolic rate with a mixed metabolism of both glycolysis and oxidative phosphorylation (OXPHOS) in early and late proliferation, an increased dependence on OXPHOS activity during differentiation, and a shift to glycolytic metabolism only during maturation phase. These changes indicate that cell metabolism may have an important impact on the ability of HSPCs to proliferate and differentiate into red blood cells.

  4. UCP2 mRNA expression is dependent on glucose metabolism in pancreatic islets

    DEFF Research Database (Denmark)

    Dalgaard, Louise Torp

    2012-01-01

    Uncoupling Protein 2 (UCP2) is expressed in the pancreatic β-cell, where it partially uncouples the mitochondrial proton gradient, decreasing both ATP-production and glucose-stimulated insulin secretion (GSIS). Increased glucose levels up-regulate UCP2 mRNA and protein levels, but the mechanism f...... down-regulation of UCP2 is involved in preserving the insulin secretory capacity of GK mutant mice and might also be implicated in limiting disease progression in MODY2 patients....

  5. A metabolic trade-off between phosphate and glucose utilization in Escherichia coli.

    Science.gov (United States)

    Behrends, Volker; Maharjan, Ram P; Ryall, Ben; Feng, Lu; Liu, Bin; Wang, Lei; Bundy, Jacob G; Ferenci, Thomas

    2014-11-01

    Getting the most out of available nutrients is a key challenge that all organisms face. Little is known about how they optimize and balance the simultaneous utilization of multiple elemental resources. We investigated the effects of long-term phosphate limitation on carbon metabolism of the model organism Escherichia coli using chemostat cultures. We profiled metabolic changes in the growth medium over time and found evidence for an increase in fermentative metabolism despite the aerobic conditions. Using full-genome sequencing and competition experiments, we found that fitness under phosphate-limiting conditions was reproducibly increased by a mutation preventing flux through succinate in the tricarboxylic acid cycle. In contrast, these mutations reduced competitive ability under carbon limitation, and thus reveal a conflicting metabolic benefit in the role of the TCA cycle in environments limited by inorganic phosphate and glucose.

  6. Adaptive mutations in sugar metabolism restore growth on glucose in a pyruvate decarboxylase negative yeast strain

    DEFF Research Database (Denmark)

    Zhang, Yiming; Liu, Guodong; Engqvist, Martin K. M.

    2015-01-01

    DNA sequencing. Among these genetic changes, 4 genes were found to carry point mutations in at least two of the evolved strains: MTH1 encoding a negative regulator of the glucose-sensing signal transduction pathway, HXT2 encoding a hexose transporter, CIT1 encoding a mitochondrial citrate synthase...... further increased the maximum specific growth rate to 0.069 h-1. Conclusions: In this study, possible evolving mechanisms of Pdc negative strains on glucose were investigated by genome sequencing and reverse engineering. The non-synonymous mutations in MTH1 alleviated the glucose repression by repressing...... expression of several hexose transporter genes. The non-synonymous mutations in HXT2 and CIT1 may function in the presence of mutated MTH1 alleles and could be related to an altered central carbon metabolism in order to ensure production of cytosolic acetyl-CoA in the Pdc negative strain....

  7. Tumor glucose metabolism imaged in vivo in small animals with whole-body photoacoustic computed tomography

    Science.gov (United States)

    Chatni, Muhammad Rameez; Xia, Jun; Sohn, Rebecca; Maslov, Konstantin; Guo, Zijian; Zhang, Yu; Wang, Kun; Xia, Younan; Anastasio, Mark; Arbeit, Jeffrey; Wang, Lihong V.

    2012-07-01

    With the increasing use of small animals for human disease studies, small-animal whole-body molecular imaging plays an important role in biomedical research. Currently, none of the existing imaging modalities can provide both anatomical and glucose molecular information, leading to higher costs of building dual-modality systems. Even with image co-registration, the spatial resolution of the molecular imaging modality is not improved. Utilizing a ring-shaped confocal photoacoustic computed tomography system, we demonstrate, for the first time, that both anatomy and glucose uptake can be imaged in a single modality. Anatomy was imaged with the endogenous hemoglobin contrast, and glucose metabolism was imaged with a near-infrared dye-labeled 2-deoxyglucose.

  8. Further studies of the influence of apolipoprotein B alleles on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Bentzen, Joan; Poulsen, Pernille; Vaag, Allan

    2003-01-01

    The effect of five genetic polymorphisms in the apolipoprotein B gene on parameters of lipid and glucose metabolism was assessed in 564 Danish mono- and dizygotic twins. Genotypes in apolipoprotein B T71I (ApaLI RFLP), A591V (AluI RFLP), L2712P (MvaI RFLP), R3611Q (MspI RFLP), and E4154K (Eco...... on the insulin-to-glucose ratio (p = 0.04), and E4154K (EcoRI RFLP) influenced HOMAbeta (p = 0.04). Significant interactions were observed between genotype in T71I (ApaLI RFLP), A591V (AluI RFLP), R3611Q (MspI RFLP), and E4154K (EcoRI RFLP) and glucose tolerance on lipid-related parameters (0.03

  9. Pancreatic A and B cell stimulation in euthermic and hibernating marmots (Marmota flaviventris): effects of glucose and arginine administration.

    Science.gov (United States)

    Florant, G L; Hoo-Paris, R; Castex, C; Bauman, W A; Sutter, B C

    1986-01-01

    In euthermic and hibernating marmots (Marmota flaviventris), the pancreatic A and B cells respond in the appropriate secretory manner to glucose or arginine injection. Although reduced, this response, is clearly present in hibernating marmots. When glucose is administered to euthermic or hibernating marmots, plasma insulin concentrations rise and glucagon levels fall. While similar results are obtained in hibernation, the time period of the response is much longer due to the slowing of temperature dependent metabolic processes. Injection of L-arginine stimulates an increase in plasma glucose, insulin, and glucagon as expected. Measurements of plasma glucose, insulin, and glucagon under basal conditions, suggest that there are no significant differences between any phase of hibernation (eg. entrance, deep hibernation, arousal) and euthermia. These results provide indirect evidence that the pancreatic A and B cells of hibernating marmots continue to function in order to help regulate plasma glucose concentration.

  10. Selective and Efficient Elimination of Vibrio cholerae with a Chemical Modulator that Targets Glucose Metabolism

    Science.gov (United States)

    Oh, Young Taek; Kim, Hwa Young; Kim, Eun Jin; Go, Junhyeok; Hwang, Wontae; Kim, Hyoung Rae; Kim, Dong Wook; Yoon, Sang Sun

    2016-01-01

    Vibrio cholerae, a Gram-negative bacterium, is the causative agent of pandemic cholera. Previous studies have shown that the survival of the seventh pandemic El Tor biotype V. cholerae strain N16961 requires production of acetoin in a glucose-rich environment. The production of acetoin, a neutral fermentation end-product, allows V. cholerae to metabolize glucose without a pH drop, which is mediated by the production of organic acid. This finding suggests that inhibition of acetoin fermentation can result in V. cholerae elimination by causing a pH imbalance under glucose-rich conditions. Here, we developed a simple high-throughput screening method and identified an inducer of medium acidification (iMAC). Of 8364 compounds screened, we identified one chemical, 5-(4-chloro-2-nitrobenzoyl)-6-hydroxy-1,3-dimethylpyrimidine-2,4(1H,3H)-dione, that successfully killed glucose-metabolizing N16961 by inducing acidic stress. When N16961 was grown with abundant glucose in the presence of iMAC, acetoin production was completely suppressed and concomitant accumulation of lactate and acetate was observed. Using a beta-galactosidase activity assay with a single-copy palsD::lacZ reporter fusion, we show that that iMAC likely inhibits acetoin production at the transcriptional level. Thin-layer chromatography revealed that iMAC causes a significantly reduced accumulation of intracellular (p)ppGpp, a bacterial stringent response alarmone known to positively regulate acetoin production. In vivo bacterial colonization and fluid accumulation were also markedly decreased after iMAC treatment. Finally, we demonstrate iMAC-induced bacterial killing for 22 different V. cholerae strains belonging to diverse serotypes. Together, our results suggest that iMAC, acting as a metabolic modulator, has strong potential as a novel antibacterial agent for treatment against cholera. PMID:27900286

  11. Sympathetic overactivity precedes metabolic dysfunction in a fructose model of glucose intolerance in mice.

    Science.gov (United States)

    De Angelis, Katia; Senador, Danielle D; Mostarda, Cristiano; Irigoyen, Maria C; Morris, Mariana

    2012-04-15

    Consumption of high levels of fructose in humans and animals leads to metabolic and cardiovascular dysfunction. There are questions as to the role of the autonomic changes in the time course of fructose-induced dysfunction. C57/BL male mice were given tap water or fructose water (100 g/l) to drink for up to 2 mo. Groups were control (C), 15-day fructose (F15), and 60-day fructose (F60). Light-dark patterns of arterial pressure (AP) and heart rate (HR), and their respective variabilities were measured. Plasma glucose, lipids, insulin, leptin, resistin, adiponectin, and glucose tolerance were quantified. Fructose increased systolic AP (SAP) at 15 and 60 days during both light (F15: 123 ± 2 and F60: 118 ± 2 mmHg) and dark periods (F15: 136 ± 4 and F60: 136 ± 5 mmHg) compared with controls (light: 111 ± 2 and dark: 117 ± 2 mmHg). SAP variance (VAR) and the low-frequency component (LF) were increased in F15 (>60% and >80%) and F60 (>170% and >140%) compared with C. Cardiac sympatho-vagal balance was enhanced, while baroreflex function was attenuated in fructose groups. Metabolic parameters were unchanged in F15. However, F60 showed significant increases in plasma glucose (26%), cholesterol (44%), triglycerides (22%), insulin (95%), and leptin (63%), as well as glucose intolerance. LF of SAP was positively correlated with SAP. Plasma leptin was correlated with triglycerides, insulin, and glucose tolerance. Results show that increased sympathetic modulation of vessels and heart preceded metabolic dysfunction in fructose-consuming mice. Data suggest that changes in autonomic modulation may be an initiating mechanism underlying the cluster of symptoms associated with cardiometabolic disease.

  12. Sexual dimorphism in glucose and lipid metabolism during fasting, hypoglycemia and exercise

    Directory of Open Access Journals (Sweden)

    Maka S Hedrington

    2015-04-01

    Full Text Available Sexually dimorphic physiologic responses occur during fasting, hypoglycemia and exercise. The areas covered in this mini review include studies that have used isotopic tracer methods and/or euglycemic clamp studies to investigate substrate metabolism during the above common physiologic stress. Women have greater reliance on lipid metabolism during fasting, hypoglycemia and exercise while men exhibit preference of carbohydrate utilization. Plasma glucose concentrations were shown to be lower, while free fatty acids (FFA and lipolysis higher in women compared to men after fasting. Hypoglycemia resulted in significantly reduced epinephrine, norepinephrine, glucagon, growth hormone, pancreatic polypeptide and hepatic glucose production responses in females as compared to males. Sexual dimorphism during exercise was demonstrated by higher glycerol and FFA responses in women compared to men and higher carbohydrate oxidation rate in men. Mechanisms that can increase lipolytic rates in women include higher total fat mass, enhanced lipolytic sensitivity to epinephrine and increased activation of β adrenergic receptors.

  13. Dietary Fiber-Induced Improvement in Glucose Metabolism Is Associated with Increased Abundance of Prevotella

    DEFF Research Database (Denmark)

    Kovatcheva-Datchary, Petia; Nilsson, Anne; Akrami, Rozita

    2015-01-01

    The gut microbiota plays an important role in human health by interacting with host diet, but there is substantial inter-individual variation in the response to diet. Here we compared the gut microbiota composition of healthy subjects who exhibited improved glucose metabolism following 3-day...... consumption of barley kernel-based bread (BKB) with those who responded least to this dietary intervention. The Prevotella/Bacteroides ratio was higher in responders than non-responders after BKB. Metagenomic analysis showed that the gut microbiota of responders was enriched in Prevotella copri and had...... increased potential to ferment complex polysaccharides after BKB. Finally, germ-free mice transplanted with microbiota from responder human donors exhibited improved glucose metabolism and increased abundance of Prevotella and liver glycogen content compared with germ-free mice that received non...

  14. Impact of expression of EMP enzymes on glucose metabolism in Zymomonas mobilis.

    Science.gov (United States)

    Chen, Rachel Ruizhen; Agrawal, Manoj; Mao, Zichao

    2013-06-01

    Zymomonas mobilis is the only known microorganism that utilizes the Entner-Doudoroff (ED) pathway anaerobically. In this work, we investigated whether the overexpression of a phosphofructokinase (PFK), the only missing Embden-Meyerhof-Parnas (EMP) pathway enzyme, could establish the pathway in this organism. Introduction of a pyrophosphate-dependent PFK, along with co-expression of homologous fructose-1,6-bisphosphate aldolase and triosephosphate isomerase, did not result in an EMP flux to any appreciable level. However, the metabolism of glucose was impacted significantly. Eight percent of glucose was metabolized to form a new metabolite, dihydroxyacetone. Reducing flux through the ED pathway by as much as 40 % through antisense of a key enzyme, ED aldolase, did not result in a fully functional EMP pathway, suggesting that the ED pathway, especially the lower arm, downstream from glyceraldehyde-3-phosphate, is very rigid, possibly due to redox balance.

  15. Prevalence of depression in individuals with impaired glucose metabolism or undiagnosed diabetes

    DEFF Research Database (Denmark)

    Nouwen, Arie; Nefs, Giesje; Caramlau, Isabela

    2011-01-01

    diagnosed type 2 diabetes (PDD) has not been the subject of a systematic review/meta-analysis. This study examined the prevalence of depression in IGM and UDD subjects relative to each other and to NGM and PDD subjects by reviewing the literature and conducting a meta-analysis of studies on this topic....... RESEARCH DESIGN AND METHODS: EMBASE and MEDLINE databases were searched for articles published up to May 2010. All studies that compared the prevalence of depression in subjects with IGM and UDD were included. Odds ratios (ORs) were calculated using fixed and random-effects models. RESULTS: The meta......OBJECTIVE: Meta-analyses have shown that the risk for depression is elevated in type 2 diabetes. Whether this risk in individuals with impaired glucose metabolism (IGM) or undiagnosed diabetes (UDD) is elevated relative to normal glucose metabolism (NGM) or decreased relative to previously...

  16. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    Science.gov (United States)

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

  17. [Comparative characteristics of glucose metabolism in the liver of rats under acute alcohol and morphine intoxication].

    Science.gov (United States)

    Lelevich, S V

    2011-01-01

    The comparative analysis effect of acute alcohol and morphine intoxications on rats on hepatic glycolysis and pentose phosphate pathway was done. The dose-dependent inhibitory effect of ethanol on activity of limiting enzymes of these metabolic ways, as well as anaerobic reorientation of glucose metabolism was recognised with the increase of the dose of the intake alcohol. Morfine (10 mg/kg) activated enymes of glycolysis and pentose phosphate pathway, but in contrast to ethanol it did not influence these parameters at the dose 20 or 40 mg/kg.

  18. The multiple connections between pRB and cell metabolism.

    Science.gov (United States)

    Nicolay, Brandon N; Dyson, Nicholas J

    2013-12-01

    The pRB tumor suppressor is traditionally seen as an important regulator of the cell cycle. pRB represses the transcriptional activation of a diverse set of genes by the E2F transcription factors and prevents inappropriate S-phase entry. Advances in our understanding of pRB have documented roles that extend beyond the cell cycle and this review summarizes recent studies that link pRB to the control of cell metabolism. pRB has been shown to regulate glucose tolerance, mitogenesis, glutathione synthesis, and the expression of genes involved in central carbon metabolism. Several studies have demonstrated that pRB directly targets a set of genes that are crucial for nucleotide metabolism, and this seems likely to represent one of the ways by which pRB influences the G1/S-phase transition and S-phase progression.

  19. Associations of fatty acids in cerebrospinal fluid with peripheral glucose concentrations and energy metabolism.

    Directory of Open Access Journals (Sweden)

    Reiner Jumpertz

    Full Text Available Rodent experiments have emphasized a role of central fatty acid (FA species, such as oleic acid, in regulating peripheral glucose and energy metabolism. Thus, we hypothesized that central FAs are related to peripheral glucose regulation and energy expenditure in humans. To test this we measured FA species profiles in cerebrospinal fluid (CSF and plasma of 32 individuals who stayed in our clinical inpatient unit for 6 days. Body composition was measured by dual energy X-ray absorptiometry and glucose regulation by an oral glucose test (OGTT followed by measurements of 24 hour (24EE and sleep energy expenditure (SLEEP as well as respiratory quotient (RQ in a respiratory chamber. CSF was obtained via lumbar punctures; FA concentrations were measured by liquid chromatography/mass spectrometry. As expected, FA concentrations were higher in plasma compared to CSF. Individuals with high concentrations of CSF very-long-chain saturated FAs had lower rates of SLEEP. In the plasma moderate associations of these FAs with higher 24EE were observed. Moreover, CSF monounsaturated long-chain FA (palmitoleic and oleic acid concentrations were associated with lower RQs and lower glucose area under the curve during the OGTT. Thus, FAs in the CSF strongly correlated with peripheral metabolic traits. These physiological parameters were most specific to long-chain monounsaturated (C16:1, C18:1 and very-long-chain saturated (C24:0, C26:0 FAs.Together with previous animal experiments these initial cross-sectional human data indicate that central FA species are linked to peripheral glucose and energy homeostasis.

  20. A palatable hyperlipidic diet causes obesity and affects brain glucose metabolism in rats

    Directory of Open Access Journals (Sweden)

    Motoyama Caio SM

    2011-09-01

    Full Text Available Abstract Background We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H or the alternation of chow (C and an H diet (CH regimen induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism. Methods Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids. Results The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups. Conclusion These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age.

  1. Hexachlorobenzene impairs glucose metabolism in a rat model of porphyria cutanea tarda: a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Mazzetti, Marta Blanca; Taira, Maria Cristina; Lelli, Sandra Marcela; Viale, Leonor Carmen San Martin de [Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428BGA, Ciudad Autonoma Buenos Aires (Argentina); Dascal, Eduardo; Basabe, Juan Carlos [Centro de Investigaciones Endocrinologicas (CEDIE). Hospital de Ninos, Dr. Ricardo Gutierrez, C1425EDF, Ciudad Autonoma Buenos Aires (Argentina)

    2004-01-01

    Hexachlobenzene (HCB), one of the most persistent environmental pollutants, induces porphyria cutanea tarda (PCT). The aim of this work was to analyze the effect of HCB on some aspects of glucose metabolism, particularly those related to its neosynthesis in vivo. For this purpose, a time-course study on gluconeogenic enzymes, pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G-6-Pase) and on pyruvate kinase (PK), a glycolytic enzyme, was carried out. Plasma glucose and insulin levels, hepatic glycogen, tryptophan contents, and the pancreatic insulin secretion pattern stimulated by glucose were investigated. Oxidative stress and heme pathway parameters were also evaluated. HCB treatment decreased PC, PEPCK, and G-6-Pase activities. The effect was observed at an early time point and grew as the treatment progressed. Loss of 60, 56, and 37%, respectively, was noted at the end of the treatment when a considerable amount of porphyrins had accumulated in the liver as a result of drastic blockage of uroporphyrinogen decarboxylase (URO-D) (95% inhibition). The plasma glucose level was reduced (one-third loss), while storage of hepatic glucose was stimulated in a time-dependent way by HCB treatment. A decay in the normal plasma insulin level was observed as fungicide intoxication progressed (twice to four times lower). However, normal insulin secretion of perifused pancreatic Langerhans islets stimulated by glucose during the 3rd and 6th weeks of treatment did not prove to be significantly affected. HCB promoted a time-dependent increase in urinary chemiluminiscence (fourfold) and hepatic malondialdehide (MDA) content (fivefold), while the liver tryptophan level was only raised at the longest intoxication times. These results would suggest that HCB treatment does not cause a primary alteration in the mechanism of pancreatic insulin secretion and that the changes induced by the fungicide on insulin levels would be an adaptative

  2. A favorable effect of hydroxychloroquine on glucose and lipid metabolism beyond its anti-inflammatory role

    OpenAIRE

    Hage, Mirella P.; Al-Badri, Marwa R.; Azar, Sami T.

    2014-01-01

    Hydroxychloroquine (HCQ), a commonly used antimalarial drug in rheumatic diseases, has shown favorable metabolic effects on both glucose control and lipid profiles. We describe a case of a young woman with type 1 diabetes whose glycemic control was optimized with the introduction of HCQ as a treatment for her Sjogren syndrome in addition to a subtle yet measurable improvement in her lipid profile. An increasing body of evidence supports the beneficial impacts of HCQ in various ancillary condi...

  3. Sleep Disturbances and Glucose Metabolism in Older Adults: The Cardiovascular Health Study

    OpenAIRE

    Strand, Linn Beate; Carnethon, Mercedes; Biggs, Mary Lou; Djoussé, Luc; Kaplan, Robert C.; David S Siscovick; Robbins, John A.; Redline, Susan; Patel, Sanjay R.; Janszky, Imre; Mukamal, Kenneth J.

    2015-01-01

    OBJECTIVE We examined the associations of symptoms of sleep-disordered breathing (SDB), which was defined as loud snoring, stopping breathing for a while during sleep, and daytime sleepiness, and insomnia with glucose metabolism and incident type 2 diabetes in older adults. RESEARCH DESIGN AND METHODS Between 1989 and 1993, the Cardiovascular Health Study recruited 5,888 participants ≥65 years of age from four U.S. communities. Participants reported SDB and insomnia symptoms yearly through 19...

  4. Nosocomial pneumonia caused by a glucose-metabolizing strain of Neisseria cinerea.

    OpenAIRE

    Boyce, J M; Taylor, M R; Mitchell, E B; Knapp, J S

    1985-01-01

    We describe what appears to be the first reported case of nosocomial pneumonia caused by Neisseria cinerea. The isolate metabolized glucose when tested in BACTEC Neisseria Differentiation Kits (Johnston Laboratories), but did not produce detectable acid in cystine-Trypticase (BBL Microbiology Systems) agar medium or in modified oxidation-fermentation medium. Clinical laboratories that rely on the BACTEC method for differentiation of pathogenic neisseriae should be aware of the fact that N. ci...

  5. IL-7 promotes Glut1 trafficking and glucose uptake via STAT5-mediated activation of Akt to support T-cell survival.

    Science.gov (United States)

    Wofford, Jessica A; Wieman, Heather L; Jacobs, Sarah R; Zhao, Yuxing; Rathmell, Jeffrey C

    2008-02-15

    Lymphocyte homeostasis requires coordination of metabolic processes with cellular energetic and biosynthetic demands but mechanisms that regulate T-cell metabolism are uncertain. We show that interleukin-7 (IL-7) is a key regulator of glucose uptake in T lymphocytes. To determine how IL-7 affects glucose uptake, we analyzed IL-7 signaling mechanisms and regulation of the glucose transporter, Glut1. The IL-7 receptor (IL-7R) stimulated glucose uptake and cell-surface localization of Glut1 in a manner that required IL-7R Y449, which promoted rapid signal transducer and activator of transcription 5 (STAT5) activation and a delayed yet sustained activation of Akt. Each pathway was necessary for IL-7 to promote glucose uptake, as Akt1(-/-) T cells or PI3-kinase inhibition and RNAi of STAT5 led to defective glucose uptake in response to IL-7. STAT5 and Akt acted in a linear pathway, with STAT5-mediated transcription leading to Akt activation, which was necessary for STAT5 and IL-7 to promote glucose uptake and prevent cell death. Importantly, IL-7 required glucose uptake to promote cell survival. These data demonstrate that IL-7 promotes glucose uptake via a novel signaling mechanism in which STAT5 transcriptional activity promotes Akt activation to regulate Glut1 trafficking and glucose uptake that is critical for IL-7 to prevent T-cell death and maintain homeostasis.

  6. IL-15 Activates the Jak3/STAT3 Signaling Pathway to Mediate Glucose Uptake in Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    James E Krolopp

    2016-12-01

    Full Text Available Myokines are specialized cytokines that are secreted from skeletal muscle (SKM in response to metabolic stimuli, such as exercise. Interleukin-15 (IL-15 is a myokine with potential to reduce obesity and increase lean mass through induction of metabolic processes. It has been previously shown that IL-15 acts to increase glucose uptake in SKM cells. However, the downstream signals orchestrating the link between IL-15 signaling and glucose uptake have not been fully explored. Here we employed the mouse SKM C2C12 cell line to examine potential downstream targets of IL-15-induced alterations in glucose uptake. Following differentiation, C2C12 cells were treated overnight with 100 ng/ml of IL-15. Activation of factors associated with glucose metabolism (Akt and AMPK and known downstream targets of IL-15 (Jak1, Jak3, STAT3, and STAT5 were assessed with IL-15 stimulation. IL-15 stimulated glucose uptake and GLUT4 translocation to the plasma membrane. IL-15 treatment had no effect on phospho-Akt, phospho-Akt substrates, phospho-AMPK, phospho-Jak1, or phospho-STAT5. However, with IL-15, phospho-Jak3 and phospho-STAT3 levels were increased along with increased interaction of Jak3 and STAT3. Additionally, IL-15 induced a translocation of phospho-STAT3 from the cytoplasm to the nucleus. We have evidence that a mediator of glucose uptake, HIF1α, expression was dependent on IL-15 induced STAT3 activation. Finally, upon inhibition of STAT3 the positive effects of IL-15 on glucose uptake and GLUT4 translocation were abolished. Taken together, we provide evidence for a novel signaling pathway for IL-15 acting through Jak3/STAT3 to regulate glucose metabolism.

  7. Hyperglycemia and anthocyanin inhibit quercetin metabolism in HepG2 cells

    Science.gov (United States)

    A high glucose (Glu) milieu promotes generation of reactive oxygen species, which may not only cause cellular damage, but also modulate phase II enzymes that are responsible for the metabolism of flavonoids. Thus, we examined the effect of a high Glu milieu on quercetin (Q) metabolism in HepG2 cells...

  8. Changes in glucose metabolism and gene expression after transfer of anti-angiogenic genes in rat hepatoma

    Energy Technology Data Exchange (ETDEWEB)

    Haberkorn, Uwe; Altmann, Annette [University of Heidelberg, INF 400, Department of Nuclear Medicine, Heidelberg (Germany); DKFZ and University of Heidelberg, INF 280, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); Hoffend, Johannes [University of Heidelberg, INF 400, Department of Nuclear Medicine, Heidelberg (Germany); Schmidt, Kerstin [University of Heidelberg, INF 400, Department of Nuclear Medicine, Heidelberg (Germany); DKFZ and University of Heidelberg, INF 280, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); University of Heidelberg, Anatomy and Developmental Biology, Medical Faculty Mannheim, Mannheim (Germany); Bonaterra, Gabriel A.; Kinscherf, Ralf [University of Heidelberg, Anatomy and Developmental Biology, Medical Faculty Mannheim, Mannheim (Germany); Dimitrakopoulou-Strauss, Antonia; Strauss, Ludwig G. [DKFZ and University of Heidelberg, INF 280, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); Eisenhut, Michael [DKFZ, INF 280, Department of Radiopharmaceutical Chemistry, Heidelberg (Germany)

    2007-12-15

    Human troponin I (TROP), the soluble receptor for vascular endothelial growth factor (sFLT) and angiostatin (ASTAT) are potent inhibitors of endothelial cell proliferation, angiogenesis and tumour growth in vivo. Transfer of these genes into tumours may induce changes not only in perfusion, but also more general ones such as changes in metabolism. The aim of this study was to assess these reactions using FDG-PET and high-throughput methods such as gene profiling. We established Morris hepatoma (MH3924A) cell lines expressing TROP, sFLT or ASTAT and quantified {sup 18}F-fluorodeoxyglucose ({sup 18}FDG) uptake by dynamic positron emission tomography (PET) after tumour inoculation in ACI rats. Furthermore, expression of glucose transporter-1 and -3 (GLUT-1 and GLUT-3) as well as hexokinase-1 and -2 were investigated by RT-PCR and immunohistomorphometry. In addition, gene array analyses were performed. {sup 18}FDG uptake, vascular fraction and distribution volume were significantly higher in all genetically modified tumours. Immunohistomorphometry showed an increased percentage of hexokinase-1 and -2 as well as GLUT-1 and -3 immunoreactive (ir) cells. Using gene arrays and comparing all three groups of genetically modified tumours, we found upregulated expression of 36 genes related to apoptosis, signal transduction, stress or metabolism. TROP-, sFLT- or ASTAT-expressing MH3924A tumours show enhanced influx of {sup 18}FDG, which seems to be caused by several factors: enhanced exchange of nutrients between blood and tumour, increased amounts of glucose transporters and hexokinases, and increased expression of genes related to apoptosis, matrix and stress, which induce an increased demand for glucose. (orig.)

  9. Effects of over-expressing resistin on glucose and lipid metabolism in mice

    Institute of Scientific and Technical Information of China (English)

    You LIU; Qun WANG; Ying-bin PAN; Zhi-jie GAO; Yan-fen LIU; Shao-hong CHEN

    2008-01-01

    Resistin, a newly discovered peptide hormone mainly secreted by adipose tissues, is present at high levels in serum of obese mice and may be a potential link between obesity and insulin resistance in rodents. However, some studies of rat and mouse models have associated insulin resistance and obesity with decreased resistin expression. In humans, no relationship between resistin level and insulin resistance or adiposity was observed. This suggests that additional studies are necessary to determine the specific role of resistin in the regulation of energy metabolism and adipogenesis. In the present study, we investigated the effect of resistin in vivo on glucose and lipid metabolism by over-expressing resistin in mice by intramuscular injection of a recombinant eukaryotic expression vector pcDNA3.1-Retn encoding porcine resistin gene. After injection, serum resistin and serum glucose (GLU) levels were significantly increased in the pcDNA3.1-Retn-treated mice; there was an obvious difference in total cholesterol (TC) level between the experiment and the control groups on Day 30. In pcDNA3.1-Retn-treated mice, both free fatty acid (FFA) and high density lipoprotein (HDL) cholesterol levels were markedly lower than those of control, whereas HDL cholesterol and triglyceride (TG) levels did not differ between the two groups. Furthermore, lipase activity was expressly lower on Day 20. Our data suggest that resistin over-expressed in mice might be responsible for insulin resistance and parameters related to glucose and lipid metabolism were changed accordingly.

  10. Olanzapine-induced changes in glucose metabolism are independent of the melanin-concentrating hormone system.

    Science.gov (United States)

    Girault, Elodie M; Toonen, Pim W; Eggels, Leslie; Foppen, Ewout; Ackermans, Mariëtte T; la Fleur, Susanne E; Fliers, Eric; Kalsbeek, Andries

    2013-11-01

    Atypical antipsychotic drugs such as Olanzapine (Ola) induce weight gain and metabolic changes associated with the development of type 2 diabetes. The mechanisms underlying these undesired side-effects are currently unknown. Chagnon et al. showed that the common allele rs7973796 of the prepro-melanin-concentrating hormone (PMCH) gene is associated with a greater body mass index in Ola-treated schizophrenic patients. As PMCH encodes for the orexigenic neuropeptide melanin-concentrating hormone (MCH), it was hypothesized that MCH is involved in Ola-induced metabolic changes. We have recently reported that the intragastric infusion of Ola results in hyperglycaemia and insulin resistance in male rats. In order to test in vivo the possible involvement of the PMCH gene in the pathogenesis of Ola side-effects, we administered Ola intragastrically in wild-type (WT) and PMCH knock-out (KO) rats. Our results show that glucose and corticosterone levels, as well as endogenous glucose production, are elevated by the infusion of Ola in both WT and KO animals. Thus, the lack of MCH does not seem to affect the acute effects of Ola on glucose metabolism. On the other hand, these effects might be obliterated by compensatory changes in other hypothalamic systems. In addition, possible modulatory effects of the MCH KO on the long term effects of Ola, i.e. increased adiposity, body weight gain, have not been investigated yet.

  11. A glucose fuel cell for implantable brain-machine interfaces.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    Full Text Available We have developed an implantable fuel cell that generates power through glucose oxidation, producing 3.4 μW cm(-2 steady-state power and up to 180 μW cm(-2 peak power. The fuel cell is manufactured using a novel approach, employing semiconductor fabrication techniques, and is therefore well suited for manufacture together with integrated circuits on a single silicon wafer. Thus, it can help enable implantable microelectronic systems with long-lifetime power sources that harvest energy from their surrounds. The fuel reactions are mediated by robust, solid state catalysts. Glucose is oxidized at the nanostructured surface of an activated platinum anode. Oxygen is reduced to water at the surface of a self-assembled network of single-walled carbon nanotubes, embedded in a Nafion film that forms the cathode and is exposed to the biological environment. The catalytic electrodes are separated by a Nafion membrane. The availability of fuel cell reactants, oxygen and glucose, only as a mixture in the physiologic environment, has traditionally posed a design challenge: Net current production requires oxidation and reduction to occur separately and selectively at the anode and cathode, respectively, to prevent electrochemical short circuits. Our fuel cell is configured in a half-open geometry that shields the anode while exposing the cathode, resulting in an oxygen gradient that strongly favors oxygen reduction at the cathode. Glucose reaches the shielded anode by diffusing through the nanotube mesh, which does not catalyze glucose oxidation, and the Nafion layers, which are permeable to small neutral and cationic species. We demonstrate computationally that the natural recirculation of cerebrospinal fluid around the human brain theoretically permits glucose energy harvesting at a rate on the order of at least 1 mW with no adverse physiologic effects. Low-power brain-machine interfaces can thus potentially benefit from having their implanted units

  12. Enhancement of energy production by black ginger extract containing polymethoxy flavonoids in myocytes through improving glucose, lactic acid and lipid metabolism.

    Science.gov (United States)

    Toda, Kazuya; Takeda, Shogo; Hitoe, Shoketsu; Nakamura, Seikou; Matsuda, Hisashi; Shimoda, Hiroshi

    2016-04-01

    Enhancement of muscular energy production is thought to improve locomotive functions and prevent metabolic syndromes including diabetes and lipidemia. Black ginger (Kaempferia parviflora) has been cultivated for traditional medicine in Thailand. Recent studies have shown that black ginger extract (KPE) activated brown adipocytes and lipolysis in white adipose tissue, which may cure obesity-related dysfunction of lipid metabolism. However, the effect of KPE on glucose and lipid utilization in muscle cells has not been examined yet. Hence, we evaluated the effect of KPE and its constituents on energy metabolism in pre-differentiated (p) and differentiated (d) C2C12 myoblasts. KPE (0.1-10 μg/ml) was added to pC2C12 cells in the differentiation process for a week or used to treat dC2C12 cells for 24 h. After culturing, parameters of glucose and lipid metabolism and mitochondrial biogenesis were assessed. In terms of the results, KPE enhanced the uptake of 2-deoxyglucose and lactic acid as well as the mRNA expression of glucose transporter (GLUT) 4 and monocarboxylate transporter (MCT) 1 in both types of cells. The expression of peroxisome proliferator-activated receptor γ coactivator (PGC)-1α was enhanced in pC2C12 cells. In addition, KPE enhanced the production of ATP and mitochondrial biogenesis. Polymethoxy flavonoids in KPE including 5-hydroxy-7-methoxyflavone, 5-hydroxy-3,7,4'-trimethoxyflavone and 5,7-dimethoxyflavone enhanced the expression of GLUT4 and PGC-1α. Moreover, KPE and 5,7-dimethoxyflavone enhanced the phosphorylation of 5'AMP-activated protein kinase (AMPK). In conclusion, KPE and its polymethoxy flavonoids were found to enhance energy metabolism in myocytes. KPE may improve the dysfunction of muscle metabolism that leads to metabolic syndrome and locomotive dysfunction.

  13. Vibrational imaging of glucose uptake activity in live cells and tissues by stimulated Raman scattering microscopy (Conference Presentation)

    Science.gov (United States)

    Hu, Fanghao; Chen, Zhixing; Zhang, Luyuan; Shen, Yihui; Wei, Lu; Min, Wei

    2016-03-01

    Glucose is consumed as an energy source by virtually all living organisms, from bacteria to humans. Its uptake activity closely reflects the cellular metabolic status in various pathophysiological transformations, such as diabetes and cancer. Extensive efforts such as positron emission tomography, magnetic resonance imaging and fluorescence microscopy have been made to specifically image glucose uptake activity but all with technical limitations. Here, we report a new platform to visualize glucose uptake activity in live cells and tissues with subcellular resolution and minimal perturbation. A novel glucose analogue with a small alkyne tag (carbon-carbon triple bond) is developed to mimic natural glucose for cellular uptake, which can be imaged with high sensitivity and specificity by targeting the strong and characteristic alkyne vibration on stimulated Raman scattering (SRS) microscope to generate a quantitative three dimensional concentration map. Cancer cells with differing metabolic characteristics can be distinguished. Heterogeneous uptake patterns are observed in tumor xenograft tissues, neuronal culture and mouse brain tissues with clear cell-cell variations. Therefore, by offering the distinct advantage of optical resolution but without the undesirable influence of bulky fluorophores, our method of coupling SRS with alkyne labeled glucose will be an attractive tool to study energy demands of living systems at the single cell level.

  14. Modulation of glucose transporter 1 (GLUT1 expression levels alters mouse mammary tumor cell growth in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Christian D Young

    Full Text Available Tumor cells exhibit an altered metabolism characterized by elevated aerobic glycolysis and lactate secretion which is supported by an increase in glucose transport and consumption. We hypothesized that reducing or eliminating the expression of the most prominently expressed glucose transporter(s would decrease the amount of glucose available to breast cancer cells thereby decreasing their metabolic capacity and proliferative potential.Of the 12 GLUT family glucose transporters expressed in mice, GLUT1 was the most abundantly expressed at the RNA level in the mouse mammary tumors from MMTV-c-ErbB2 mice and cell lines examined. Reducing GLUT1 expression in mouse mammary tumor cell lines using shRNA or Cre/Lox technology reduced glucose transport, glucose consumption, lactate secretion and lipid synthesis in vitro without altering the concentration of ATP, as well as reduced growth on plastic and in soft agar. The growth of tumor cells with reduced GLUT1 expression was impaired when transplanted into the mammary fat pad of athymic nude mice in vivo. Overexpression of GLUT1 in a cell line with low levels of endogenous GLUT1 increased glucose transport in vitro and enhanced growth in nude mice in vivo as compared to the control cells with very low levels of GLUT1.These studies demonstrate that GLUT1 is the major glucose transporter in mouse mammary carcinoma models overexpressing ErbB2 or PyVMT and that modulation of the level of GLUT1 has an effect upon the growth of mouse mammary tumor cell lines in vivo.

  15. Evaluation of hepatic glucose metabolism via gluconeogenesis and glycogenolysis after oral administration of insulin nanoparticles.

    Science.gov (United States)

    Woitiski, Camile B; Neufeld, Ronald J; Soares, Ana F; Figueiredo, Isabel V; Veiga, Francisco J; Carvalho, Rui A

    2012-12-01

    Nanoparticles were designed to promote insulin intestinal absorption via the oral route, to increase portal insulin levels to better mimic the physiological pathway, providing enhanced glucose control through glycogenolysis and gluconeogenesis. Nanoparticles were formulated with insulin encapsulated in the core material consisting of alginate and dextran sulfate, associated with poloxamer and subsequently coated with chitosan then albumin. A spherical and slightly rough core was observed in electron micrographs with the appearance of a concentration gradient of the polysaccharide structure toward the periphery of the nanoparticle. Atomic force microscopy showed that the fully formed nanoparticles are about 200 nm in diameter with smooth and spherical morphology. Histopathological analysis of organs and tissues of diabetic rats dosed daily for 15 days with insulin nanoparticles was used to evaluate toxicological issues. No morphological or pathological alterations were observed in rat liver, spleen, pancreas, kidney or intestinal sections. Following, the effect of nanoencapsulated insulin on inhibiting hepatic gluconeogenesis was evaluated after a single insulin administration and oral glucose tolerance test, which represents a significant metabolic challenge to the liver. Alterations in the hepatic glucose metabolism of fasted streptozotocin-diabetic rats were determined by the percent contribution of glycogenolysis and gluconeogenesis, measured by using metabolic tracers, however similar gluconeogenesis contribution to the hepatic metabolism was observed between diabetic rats receiving nanoencapsulated insulin or insulin solution. The metabolic results may be explained by the inability of a single dose in shifting the gluconeogenesis/glycogenolysis contributions, sampling time, fasting period or by influence of the kidney enzymes and impairment in insulin signaling observed in stz-diabetic rats.

  16. Insulin-dependent glucose metabolism in dairy cows with variable fat mobilization around calving.

    Science.gov (United States)

    Weber, C; Schäff, C T; Kautzsch, U; Börner, S; Erdmann, S; Görs, S; Röntgen, M; Sauerwein, H; Bruckmaier, R M; Metges, C C; Kuhla, B; Hammon, H M

    2016-08-01

    Dairy cows undergo significant metabolic and endocrine changes during the transition from pregnancy to lactation, and impaired insulin action influences nutrient partitioning toward the fetus and the mammary gland. Because impaired insulin action during transition is thought to be related to elevated body condition and body fat mobilization, we hypothesized that over-conditioned cows with excessive body fat mobilization around calving may have impaired insulin metabolism compared with cows with low fat mobilization. Nineteen dairy cows were grouped according to their average concentration of total liver fat (LFC) after calving in low [LLFC; LFC 24.4% total fat/DM; n=10) fat-mobilizing cows. Blood samples were taken from wk 7 antepartum (ap) to wk 5 postpartum (pp) to determine plasma concentrations of glucose, insulin, glucagon, and adiponectin. We applied euglycemic-hyperinsulinemic (EGHIC) and hyperglycemic clamps (HGC) in wk 5 ap and wk 3 pp to measure insulin responsiveness in peripheral tissue and pancreatic insulin secretion during the transition period. Before and during the pp EGHIC, [(13)C6] glucose was infused to determine the rate of glucose appearance (GlucRa) and glucose oxidation (GOx). Body condition, back fat thickness, and energy-corrected milk were greater, but energy balance was lower in HLFC than in LLFC. Plasma concentrations of glucose, insulin, glucagon, and adiponectin decreased at calving, and this was followed by an immediate increase of glucagon and adiponectin after calving. Insulin concentrations ap were higher in HLFC than in LLFC cows, but the EGHIC indicated no differences in peripheral insulin responsiveness among cows ap and pp. However, GlucRa and GOx:GlucRa during the pp EGHIC were greater in HLFC than in LLFC cows. During HGC, pancreatic insulin secretion was lower, but the glucose infusion rate was higher pp than ap in both groups. Plasma concentrations of nonesterified fatty acids decreased during HGC and EGHIC, but in both

  17. Killing of glucose-deprived hypoxic cells with moderate hyperthermia. [HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1978-08-01

    Investigations were carried out to determine the importance of glucose as a modifying factor for hyperthermic cellular damage. HeLa S-3 cells were heated under oxic and hypoxic conditions, in the presence and absence of D-glucose. Temperatures as low as 41/sup 0/C selectively enhanced killing of the glucose deprived hypoxic cell. Glucose deprivation (37/sup 0/C, 2 hr) or heat alone (41/sup 0/C for 2 hr in regular medium with glucose) produced minimal cell kill under oxic or hypoxic conditions. No enhancement was seen with hyperthermia under oxic condition in the absence of glucose. The result suggests that the interplay between glucose concentration is important for hyperthermic cell kill.

  18. Effects of Cooling and Supplemental Bovine Somatotropin on Milk Production relating to Body Glucose Metabolism and Utilization of Glucose by the Mammary Gland in Crossbred Holstein Cattle

    Directory of Open Access Journals (Sweden)

    Siravit Sitprija

    2010-01-01

    Full Text Available Problem statement: The low milk yield and shorter persistency of lactation of dairy cattle is the major problem for the dairy practices in the tropics. High environmental temperatures and rapid decline of plasma growth hormone level can influence milk production. Regulation of the milk yield of animals is mainly based on the mechanisms governing the quantity of glucose extracted by the mammary gland for lactose biosynthetic pathways. The mechanism(s underlying the effects of cooling and supplemental bovine somatotropin on milk production relating to body glucose metabolism and intracellular metabolism of glucose in the mammary gland of crossbred Holstein cattle in the tropics have not been investigated to date. Approach: Ten crossbred 87.5% Holstein cows were divided into two groups of five animals each. Animals were housed in Normal Shade barn (NS as non-cooled cows and cows in the second group were housed in barn which was equipped with a two Misty-Fan cooling system (MF as cooled cows. Supplementation of recombinant bovine Somatotropin (rbST (POSILAC, 500 mg per cow were performed in both groups to study body glucose metabolism and the utilization of glucose in the mammary gland using a continuous infusion of [3-3H] glucose and [U- 14C] glucose as markers in early, mid and late stages of lactation. Results: Milk yield significantly increased in both groups during supplemental rbST with a high level of mammary blood flow. Body glucose turnover rates were not significant different between cooled and non-cooled cows whether supplemental rbST or not. The glucose taken up by the mammary gland of both non-cooled and cooled cows increased flux through the lactose synthesis and the pentose cycle pathway with significant increases in NADPH formation for fatty acid synthesis during rbST supplementation. The utilization of glucose carbon incorporation into milk appeared to increase in milk lactose and milk triacylglycerol but not for

  19. SH2B1 regulation of energy balance, body weight, and glucose metabolism

    Institute of Scientific and Technical Information of China (English)

    Liangyou; Rui

    2014-01-01

    The Src homology 2B(SH2B)family members(SH2B1,SH2B2 and SH2B3)are adaptor signaling proteins containing characteristic SH2 and PH domains.SH2B1(also called SH2-B and PSM)and SH2B2(also called APS)are able to form homo-or hetero-dimers via their N-terminal dimerization domains.Their C-terminal SH2 domains bind to tyrosyl phosphorylated proteins,including Janus kinase 2(JAK2),TrkA,insulin receptors,insulin-like growth factor-1 receptors,insulin receptor substrate-1(IRS1),and IRS2.SH2B1 enhances leptin signaling by both stimulating JAK2 activity and assembling a JAK2/IRS1/2 signaling complex.SH2B1 promotes insulin signaling by both enhancing insulin receptor catalytic activity and protecting against dephosphorylation of IRS proteins.Accordingly,genetic deletion of SH2B1 results in severe leptin resistance,insulin resistance,hyperphagia,obesity,and type 2 diabetes in mice.Neuronspecific overexpression of SH2B1βtransgenes protects against diet-induced obesity and insulin resistance.SH2B1 in pancreaticβcells promotesβcell expansion and insulin secretion to counteract insulin resistance in obesity.Moreover,numerous SH2B1 mutations are genetically linked to leptin resistance,insulin resistance,obesity,and type 2 diabetes in humans.Unlike SH2B1,SH2B2 and SH2B3 are not required for the maintenance of normal energy and glucose homeostasis.The metabolic function of the SH2B family is conserved from insects to humans.

  20. Metabolic measurements in cell culture and tissue constructs

    Science.gov (United States)

    Rolfe, P.

    2008-10-01

    This paper concerns the study and use of biological cells in which there is a need for sensors and assemblies for the measurement of a diverse range of physical and chemical variables. In this field cell culture is used for basic research and for applications such as pro