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Sample records for affects glut4 expression

  1. Impact of pre-gestational and gestational diabetes mellitus on the expression of glucose transporters GLUT-1, GLUT-4 and GLUT-9 in human term placenta.

    Science.gov (United States)

    Stanirowski, Paweł Jan; Szukiewicz, Dariusz; Pyzlak, Michał; Abdalla, Nabil; Sawicki, Włodzimierz; Cendrowski, Krzysztof

    2017-03-01

    Various studies in placental tissue suggest that diabetes mellitus alters the expression of glucose transporter (GLUT) proteins, with insulin therapy being a possible modulatory factor. The aim of the present study was quantitative evaluation of the expression of glucose transporters (GLUT-1, GLUT-4, GLUT-9) in the placenta of women in both, uncomplicated and diabetic pregnancy. Additionally, the effect of insulin therapy on the expression of selected glucose transporter isoforms was analyzed. Term placental samples were obtained from healthy control (n = 25) and diabetic pregnancies, including diet-controlled gestational diabetes mellitus (GDMG1) (n = 16), insulin-controlled gestational diabetes mellitus (GDMG2) (n = 6), and pre-gestational diabetes mellitus (PGDM) (n = 6). Computer-assisted quantitative morphometry of stained placental sections was performed to determine the expression of selected glucose transporter proteins. Morphometric analysis revealed a significant increase in the expression of GLUT-4 and GLUT-9 in insulin-dependent diabetic women (GDMG2 + PGDM) as compared to both, control and GDMG1 groups (p diabetic pregnancies. In addition, insulin therapy may increase placental expression of GLUT-4 and GLUT-9, and partially GLUT-1, in women with GDMG2/PGDM.

  2. Hexose transporter mRNAs for GLUT4, GLUT5, and GLUT12 predominate in human muscle.

    Science.gov (United States)

    Stuart, Charles A; Yin, Deling; Howell, Mary E A; Dykes, Rhesa J; Laffan, John J; Ferrando, Arny A

    2006-11-01

    In the past few years, 8 additional members of the facilitative hexose transporter family have been identified, giving a total of 14 members of the SLC2A family of membrane-bound hexose transporters. To determine which of the new hexose transporters were expressed in muscle, mRNA concentrations of 11 glucose transporters (GLUTs) were quantified and compared. RNA from muscle from 10 normal volunteers was subjected to RT-PCR. Primers were designed that amplified 78- to 241-base fragments, and cDNA standards were cloned for GLUT1, GLUT2, GLUT3, GLUT4, GLUT5, GLUT6, GLUT8, GLUT9, GLUT10, GLUT11, GLUT12, and GAPDH. Seven of these eleven hexose transporters were detectable in normal human muscle. The rank order was GLUT4, GLUT5, GLUT12, GLUT8, GLUT11, GLUT3, and GLUT1, with corresponding concentrations of 404 +/- 49, 131 +/- 14, 33 +/- 4, 5.5 +/- 0.5, 4.1 +/- 0.4, 1.2 +/- .0.1, and 0.9 +/- 0.2 copies/ng RNA (means +/- SE), respectively, for the 10 subjects. Concentrations of mRNA for GLUT4, GLUT5, and GLUT12 were much higher than those for the remainder of the GLUTs and together accounted for 98% of the total GLUT isoform mRNA. Immunoblots of muscle homogenates verified that the respective proteins for GLUT4, GLUT5, and GLUT12 were present in normal human muscle. Immunofluorescent studies demonstrated that GLUT4 and GLUT12 were predominantly expressed in type I oxidative fibers; however, GLUT5 was expressed predominantly in type II (white) fibers.

  3. Expression and localization of GLUT1 and GLUT12 in prostate carcinoma.

    Science.gov (United States)

    Chandler, Jenalle D; Williams, Elizabeth D; Slavin, John L; Best, James D; Rogers, Suzanne

    2003-04-15

    Increased glucose consumption is a characteristic of malignant cells and in prostate carcinoma is associated with the proliferation of both androgen-dependent and independent cells. Transport of polar glucose across the nonpolar membrane relies on glucose transporter proteins, known as GLUTs. Increased expression of GLUT1 is a characteristic of many malignant cells. The authors characterized and cloned the cDNA for a novel glucose transporter, GLUT12, which was identified initially in malignant breast epithelial cells. To the authors' knowledge, there have been no reports on the expression of glucose transporters in the human prostate or human prostate carcinoma cells. The authors evaluated GLUT1 and GLUT12 expression in human prostate carcinoma cells. Reverse transcription-polymerase chain reaction was performed on total RNA extracted from cultured prostate carcinoma cells LNCaP, C4, C4-2, and C4-2B using primers to amplify GLUT1, GLUT12, or the housekeeping gene, 36B4. Total protein extracted from prostate carcinoma cell lines was assessed for GLUT12 protein by Western blot analysis. Cultured cell monolayers were incubated with antibodies to GLUT1 or GLUT12 and a peripheral Golgi protein, Golgi 58K, for detection by immunofluorescent confocal microscopy. Sections of benign prostatic hyperplasia and human prostate carcinoma were stained for immunohistochemical detection of GLUT1 and GLUT12. GLUT1 and GLUT12 mRNA and protein were detected in all cell lines evaluated. Immunofluorescence staining demonstrated both GLUT1 and GLUT12 on the plasma membrane and in the cytoplasm in all cultured prostate carcinoma cell lines, with GLUT1 but not GLUT12 appearing to colocalize with the Golgi. Immunohistochemical staining of benign prostatic hyperplasia indicated expression of GLUT1 but not GLUT12. Malignant tissue stained for GLUT12 but was negative for GLUT1. GLUT1 and GLUT12 are expressed in human prostate carcinoma cells. One possible rationale for the GLUT1 Golgi

  4. Nuclear factor 1 regulates adipose tissue-specific expression in the mouse GLUT4 gene

    International Nuclear Information System (INIS)

    Miura, Shinji; Tsunoda, Nobuyo; Ikeda, Shinobu; Kai, Yuko; Cooke, David W.; Lane, M. Daniel; Ezaki, Osamu

    2004-01-01

    Previous studies demonstrated that an adipose tissue-specific element(s) (ASE) of the murine GLUT4 gene is located between -551 and -506 in the 5'-flanking sequence and that a high-fat responsive element(s) for down-regulation of the GLUT4 gene is located between bases -701 and -552. A binding site for nuclear factor 1 (NF1), that mediates insulin and cAMP-induced repression of GLUT4 in 3T3-L1 adipocytes is located between bases -700 and -688. To examine the role of NF1 in the regulation of GLUT4 gene expression in white adipose tissues (WAT) in vivo, we created two types of transgenic mice harboring mutated either 5' or 3' half-site of NF1-binding sites in GLUT4 minigene constructs. In both cases, the GLUT4 minigene was not expressed in WAT, while expression was maintained in brown adipose tissue, skeletal muscle, and heart. This was an unexpected finding, since a -551 GLUT4 minigene that did not have the NF1-binding site was expressed in WAT. We propose a model that explains the requirement for both the ASE and the NF1-binding site for expression of GLUT4 in WAT

  5. Analysis of correlations between the placental expression of glucose transporters GLUT-1, GLUT-4 and GLUT-9 and selected maternal and fetal parameters in pregnancies complicated by diabetes mellitus.

    Science.gov (United States)

    Stanirowski, Paweł Jan; Szukiewicz, Dariusz; Pyzlak, Michał; Abdalla, Nabil; Sawicki, Włodzimierz; Cendrowski, Krzysztof

    2017-10-16

    The aim of the study was to analyze the correlations between the expression of glucose transporters GLUT-1, GLUT-4, and GLUT-9 in human term placenta and selected maternal and fetal parameters in pregnancies complicated by diabetes mellitus (DM). Placental samples were obtained from healthy control (n = 25) and diabetic pregnancies, including diet-controlled gestational diabetes mellitus (GDMG1) (n = 16), insulin-controlled gestational diabetes mellitus (GDMG2) (n = 6), and pregestational DM (PGDM) (n = 6). Computer-assisted quantitative morphometry of stained placental sections was performed to determine the expression of selected glucose transporter proteins. For the purposes of correlation analysis, the following parameters were selected: type of diabetes, gestational age, maternal prepregnancy body mass index (BMI), gestational weight gain, third trimester glycated hemoglobin concentration, placental weight, fetal birth weight (FBW) as well as ultrasonographic indicators of fetal adiposity, including subscapular (SSFM), abdominal (AFM), and midthigh (MTFM) fat mass measurements. In the PGDM group, the analysis demonstrated positive correlations between the placental expression of GLUT-1, GLUT-4, and GLUT-9 and FBW, AFM, and SSFM measurements (p diabetes and FBW were significantly associated with GLUTs expression (p < .001). In addition, maternal prepregnancy BMI significantly contributed to GLUT-1 expression (p < .001). The study results revealed that placental expression of GLUT-1, GLUT-4, and GLUT-9 may be involved in the intensification of the fetal growth in pregnancies complicated by GDM/PGDM.

  6. Changes in photoperiod alter Glut4 expression in skeletal muscle of C57BL/6J mice

    International Nuclear Information System (INIS)

    Tashiro, Ayako; Shibata, Satomi; Takai, Yusuke; Uchiwa, Tatsuhiro; Furuse, Mitsuhiro; Yasuo, Shinobu

    2017-01-01

    Seasonal changes in photoperiod influence body weight and metabolism in mice. Here, we examined the effect of changes in photoperiod on the expression of glucose transporter genes in the skeletal muscle and adipose tissue of C57BL/6J mice. Glut4 expression was lower in the gastrocnemius muscle of mice exposed to a short-duration day (SD) than those to a long-duration day (LD), with accompanying changes in GLUT4 protein levels. Although Glut4 expression in the mouse soleus muscle was higher under SD than under LD, GLUT4 protein levels remained unchanged. To confirm the functional significance of photoperiod-induced changes in Glut4 expression, we checked for variations in insulin sensitivity. Blood glucose levels after insulin injection remained high under SD, suggesting that the mice exposed to SD showed lower sensitivity to insulin than those exposed to LD. We also attempted to clarify the relationship between Glut4 expression and physical activity in the mice following changes in photoperiod. Locomotor activity, as detected via infrared beam sensor, was lower under SD than under LD. However, when we facilitated voluntary activity by using running wheels, the rotation of wheels was similar for both groups of mice. Although physical activity levels were enhanced due to running wheels, Glut4 expression in the gastrocnemius muscle remained unchanged. Thus, variations in photoperiod altered Glut4 expression in the mouse skeletal muscle, with subsequent changes in GLUT4 protein levels and insulin sensitivity; these effects might be independent of physical activity. - Highlights: • Glut4 expression in the gastrocnemius muscle was lowered under short photoperiod. • Insulin sensitivity was lowered under short photoperiod. • Access to running wheels did not alter Glut4 expression in the gastrocnemius muscle. • Photoperiodic changes in Glut4 expression may be independent of physical activity.

  7. GLUT11, but not GLUT8 or GLUT12, is expressed in human skeletal muscle in a fibre type-specific pattern

    DEFF Research Database (Denmark)

    Gaster, M; Handberg, A; Schürmann, A

    2004-01-01

    or amyotrophic lateral sclerosis (ALS) were studied. GLUT8 and 12 immunoreactivity was below detection level in both developing and adult muscle fibres. GLUT11 immunoreactivity, however, was present in slow-twitch muscle fibres, but not in fast twitch fibres. Since, in contrast, GLUT4 was expressed in all...... exclusively in slow-twitch muscle fibres and is unaffected by physiological and pathophysiological conditions except in primary myopathy. GLUT8 and GLUT12 do not appear to be of importance in human muscle under physiological and pathophysiological conditions....... to induce GLUT8 or -12 expression. Likewise, the fibre type-dependent pattern of GLUT11 immunoreactivity was unaltered. However, some slow muscle fibres lose their GLUT11 immunoreactivity under regeneration. Our results indicate that GLUT11 immunoreactivity, in contrast to that of GLUT4, is expressed...

  8. Expression, purification, and functional characterization of the insulin-responsive facilitative glucose transporter GLUT4.

    Science.gov (United States)

    Kraft, Thomas E; Hresko, Richard C; Hruz, Paul W

    2015-12-01

    The insulin-responsive facilitative glucose transporter GLUT4 is of fundamental importance for maintenance of glucose homeostasis. Despite intensive effort, the ability to express and purify sufficient quantities of structurally and functionally intact protein for biophysical analysis has previously been exceedingly difficult. We report here the development of novel methods to express, purify, and functionally reconstitute GLUT4 into detergent micelles and proteoliposomes. Rat GLUT4 containing FLAG and His tags at the amino and carboxy termini, respectively, was engineered and stably transfected into HEK-293 cells. Overexpression in suspension culture yielded over 1.5 mg of protein per liter of culture. Systematic screening of detergent solubilized GLUT4-GFP fusion protein via fluorescent-detection size exclusion chromatography identified lauryl maltose neopentyl glycol (LMNG) as highly effective for isolating monomeric GLUT4 micelles. Preservation of structural integrity and ligand binding was demonstrated via quenching of tryptophan fluorescence and competition of ATB-BMPA photolabeling by cytochalasin B. GLUT4 was reconstituted into lipid nanodiscs and proper folding was confirmed. Reconstitution of purified GLUT4 with amphipol A8-35 stabilized the transporter at elevated temperatures for extended periods of time. Functional activity of purified GLUT4 was confirmed by reconstitution of LMNG-purified GLUT4 into proteoliposomes and measurement of saturable uptake of D-glucose over L-glucose. Taken together, these data validate the development of an efficient means to generate milligram quantities of stable and functionally intact GLUT4 that is suitable for a wide array of biochemical and biophysical analyses. © 2015 The Protein Society.

  9. Triiodothyronine Acutely Stimulates Glucose Transport into L6 Muscle Cells Without Increasing Surface GLUT4, GLUT1, or GLUT3

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    Teixeira, Silvania Silva; Tamrakar, Akhilesh K.; Goulart-Silva, Francemilson; Serrano-Nascimento, Caroline; Klip, Amira

    2012-01-01

    Background Thyroid hormones (THs) act genomically to stimulate glucose transport by elevating glucose transporter (Slc2a) expression and glucose utilization by cells. However, nongenomic effects of THs are now emerging. Here, we assess how triiodothyronine (T3) acutely affects glucose transport and the content of GLUT4, GLUT1, and GLUT3 at the surface of muscle cells, and possible interactions between T3 and insulin action. Methods Differentiated L6 myotubes transfected with myc-tagged Slc2a4 (L6-GLUT4myc) or Slc2a1 (L6-GLUT1myc) and wild-type L6 myotubes were studied in the following conditions: control, hypothyroid (Tx), Tx plus T3, Tx plus insulin, and Tx plus insulin and T3. Results Glucose uptake and GLUT4 content at the cell surface decreased in the Tx group relative to controls. T3 treatment for 30 minutes increased glucose transport into L6-GLUT4myc cells without altering surface GLUT4 content, which increased only thereafter. The total amount of GLUT4 protein remained unchanged among the groups studied. The surface GLUT1 content of L6-GLUT1myc cells also remained unaltered after T3 treatment; however, in these cells glucose transport was not stimulated by T3. In wild-type L6 cells, although T3 treatment increased the total amount of GLUT3, it did not change the surface GLUT3 content. Moreover, within 30 minutes, T3 stimulation of glucose uptake was additive to that of insulin in L6-GLUT4myc cells. As expected, insulin elevated surface GLUT4 content and glucose uptake. However, interestingly, surface GLUT4 content remained unchanged or even dropped with T3 plus insulin. Conclusions These data reveal that T3 rapidly increases glucose uptake in L6-GLUT4myc cells, which, at least for 30 minutes, did not depend on an increment in GLUT4 at the cell surface yet potentiates insulin action. We propose that this rapid T3 effect involves activation of GLUT4 transporters at the cell surface, but cannot discount the involvement of an unknown GLUT. PMID:22663547

  10. Regenerating human muscle fibres express GLUT3 protein

    DEFF Research Database (Denmark)

    Gaster, M; Beck-Nielsen, H; Schrøder, H D

    2002-01-01

    The presence of the GLUT3 glucose transporter protein in human muscle cells is a matter of debate. The present study was designed to establish whether GLUT3 is expressed in mature human skeletal muscle fibres and, if so, whether its expression changes under different conditions, such as metabolic...... muscle fibres, nor did metabolic stress, training or de- and re-innervation induce GLUT3 expression, while a few GLUT3 expressing fibres were seen in some cases of polymyositis. In contrast, GLUT4 was expressed in all investigated muscle fibres. GLUT3 immunoreactivity was found in perineural...... and endoneural cells, indicating that GLUT3 is important for glucose transport into nerves through the perineurium. Taken together, these data suggest that GLUT3 expression is restricted to regenerating muscle fibres and nerves in adult human muscle. Although the significance of GLUT3 in adult human muscle...

  11. The effect of intensive insulin therapy on the insulin-regulatable glucose transporter (GLUT4) expression in skeletal muscle in type 1 diabetes

    DEFF Research Database (Denmark)

    Andersen, P H; Vestergaard, H; Lund, S

    1993-01-01

    h given to patients with Type 1 diabetes in poor metabolic control was associated with an adaptive regulation of GLUT4 mRNA and protein levels in vastus lateralis muscle. Nine Type 1 diabetic patients with a mean HbA1c of 10.3% were included in the protocol. After intensified treatment with soluble.......54). These results suggest, that in spite of evidence that high insulin levels affect GLUT4 expression in muscle, changes in serum insulin within the physiological range do not play a major role in the short-term regulation of GLUT4 expression in Type 1 diabetic patients....

  12. Peripheral insulin resistance in ILK-depleted mice by reduction of GLUT4 expression.

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    Hatem-Vaquero, Marco; Griera, Mercedes; García-Jerez, Andrea; Luengo, Alicia; Álvarez, Julia; Rubio, José A; Calleros, Laura; Rodríguez-Puyol, Diego; Rodríguez-Puyol, Manuel; De Frutos, Sergio

    2017-08-01

    The development of insulin resistance is characterized by the impairment of glucose uptake mediated by glucose transporter 4 (GLUT4). Extracellular matrix changes are induced when the metabolic dysregulation is sustained. The present work was devoted to analyze the possible link between the extracellular-to-intracellular mediator integrin-linked kinase (ILK) and the peripheral tissue modification that leads to glucose homeostasis impairment. Mice with general depletion of ILK in adulthood (cKD-ILK) maintained in a chow diet exhibited increased glycemia and insulinemia concurrently with a reduction of the expression and membrane presence of GLUT4 in the insulin-sensitive peripheral tissues compared with their wild-type littermates (WT). Tolerance tests and insulin sensitivity indexes confirmed the insulin resistance in cKD-ILK, suggesting a similar stage to prediabetes in humans. Under randomly fed conditions, no differences between cKD-ILK and WT were observed in the expression of insulin receptor (IR-B) and its substrate IRS-1 expressions. The IR-B isoform phosphorylated at tyrosines 1150/1151 was increased, but the AKT phosphorylation in serine 473 was reduced in cKD-ILK tissues. Similarly, ILK-blocked myotubes reduced their GLUT4 promoter activity and GLUT4 expression levels. On the other hand, the glucose uptake capacity in response to exogenous insulin was impaired when ILK was blocked in vivo and in vitro , although IR/IRS/AKT phosphorylation states were increased but not different between groups. We conclude that ILK depletion modifies the transcription of GLUT4, which results in reduced peripheral insulin sensitivity and glucose uptake, suggesting ILK as a molecular target and a prognostic biomarker of insulin resistance. © 2017 Society for Endocrinology.

  13. Muscle GLUT4 in cirrhosis

    DEFF Research Database (Denmark)

    Holland-Fischer, Peter; Andersen, Per Heden; Lund, Sten

    2007-01-01

    test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively. RESULTS: GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance......: In cirrhosis GLUT4 protein content was quantitatively intact, while limiting glucose tolerance. This indicates loss of redundancy of the major glucose transport system, possibly related to the markedly decreased expression of its gene. Hyper-insulinemia may be a primary event. Our findings implicate...

  14. Direct evidence of fiber type-dependent GLUT-4 expression in human skeletal muscle

    DEFF Research Database (Denmark)

    Gaster, M; Poulsen, P; Handberg, A

    2000-01-01

    GLUT-4 expression in individual fibers of human skeletal muscles in younger and older adults was studied. Furthermore, the dependency of insulin-stimulated glucose uptake on fiber type distribution was investigated. Fiber type distribution was determined in cryosections of muscle biopsies from 8...... of slow fibers in the young (r = -0.45, P > 0.25) or in the elderly (r = 0. 11, P > 0.75) subjects. In conclusion, in human skeletal muscle, GLUT-4 expression is fiber type dependent and decreases with age, particularly in fast muscle fibers....

  15. GLUT4 expression at the plasma membrane is related to fibre volume in human skeletal muscle fibres

    DEFF Research Database (Denmark)

    Gaster, M; Vach, W; Beck-Nielsen, H

    2002-01-01

    In this study we examined the relationship between GLUT4 expression at the plasma membrane and muscle fibre size in fibre-typed human muscle fibres by immunocytochemistry and morphometry in order to gain further insight into the regulation of GLUT4 expression. At the site of the plasma membrane...

  16. Comparison of GLUT1, GLUT3, and GLUT4 mRNA and the subcellular distribution of their proteins in normal human muscle

    Science.gov (United States)

    Stuart, C. A.; Wen, G.; Gustafson, W. C.; Thompson, E. A.

    2000-01-01

    Basal, "insulin-independent" glucose uptake into skeletal muscle is provided by glucose transporters positioned at the plasma membrane. The relative amount of the three glucose transporters expressed in muscle has not been previously quantified. Using a combination of qualitative and quantitative ribonuclease protection assay (RPA) methods, we found in normal human muscle that GLUT1, GLUT3, and GLUT4 mRNA were expressed at 90 +/- 10, 46 +/- 4, and 156 +/- 12 copies/ng RNA, respectively. Muscle was fractionated by DNase digestion and differential sedimentation into membrane fractions enriched in plasma membranes (PM) or low-density microsomes (LDM). GLUT1 and GLUT4 proteins were distributed 57% to 67% in LDM, whereas GLUT3 protein was at least 88% in the PM-enriched fractions. These data suggest that basal glucose uptake into resting human muscle could be provided in part by each of these three isoforms.

  17. (+-Rutamarin as a dual inducer of both GLUT4 translocation and expression efficiently ameliorates glucose homeostasis in insulin-resistant mice.

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    Yu Zhang

    Full Text Available Glucose transporter 4 (GLUT4 is a principal glucose transporter in response to insulin, and impaired translocation or decreased expression of GLUT4 is believed to be one of the major pathological features of type 2 diabetes mellitus (T2DM. Therefore, induction of GLUT4 translocation or/and expression is a promising strategy for anti-T2DM drug discovery. Here we report that the natural product (+-Rutamarin (Rut functions as an efficient dual inducer on both insulin-induced GLUT4 translocation and expression. Rut-treated 3T3-L1 adipocytes exhibit efficiently enhanced insulin-induced glucose uptake, while diet-induced obese (DIO mice based assays further confirm the Rut-induced improvement of glucose homeostasis and insulin sensitivity in vivo. Subsequent investigation of Rut acting targets indicates that as a specific protein tyrosine phosphatase 1B (PTP1B inhibitor Rut induces basal GLUT4 translocation to some extent and largely enhances insulin-induced GLUT4 translocation through PI3 kinase-AKT/PKB pathway, while as an agonist of retinoid X receptor α (RXRα, Rut potently increases GLUT4 expression. Furthermore, by using molecular modeling and crystallographic approaches, the possible binding modes of Rut to these two targets have been also determined at atomic levels. All our results have thus highlighted the potential of Rut as both a valuable lead compound for anti-T2DM drug discovery and a promising chemical probe for GLUT4 associated pathways exploration.

  18. Glucose transporters GLUT4 and GLUT8 are upregulated after facial nerve axotomy in adult mice.

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    Gómez, Olga; Ballester-Lurbe, Begoña; Mesonero, José E; Terrado, José

    2011-10-01

    Peripheral nerve axotomy in adult mice elicits a complex response that includes increased glucose uptake in regenerating nerve cells. This work analyses the expression of the neuronal glucose transporters GLUT3, GLUT4 and GLUT8 in the facial nucleus of adult mice during the first days after facial nerve axotomy. Our results show that whereas GLUT3 levels do not vary, GLUT4 and GLUT8 immunoreactivity increases in the cell body of the injured motoneurons after the lesion. A sharp increase in GLUT4 immunoreactivity was detected 3 days after the nerve injury and levels remained high on Day 8, but to a lesser extent. GLUT8 also increased the levels but later than GLUT4, as they only rose on Day 8 post-lesion. These results indicate that glucose transport is activated in regenerating motoneurons and that GLUT4 plays a main role in this function. These results also suggest that metabolic defects involving impairment of glucose transporters may be principal components of the neurotoxic mechanisms leading to motoneuron death. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

  19. Demonstration of differential quantitative requirements for NSF among multiple vesicle fusion pathways of GLUT4 using a dominant-negative ATPase-deficient NSF

    International Nuclear Information System (INIS)

    Chen Xiaoli; Matsumoto, Hideko; Hinck, Cynthia S.; Al-Hasani, Hadi; St-Denis, Jean-Francois; Whiteheart, Sidney W.; Cushman, Samuel W.

    2005-01-01

    In this study, we investigated the relative participation of N-ethylmaleimide-sensitive factor (NSF) in vivo in a complex multistep vesicle trafficking system, the translocation response of GLUT4 to insulin in rat adipose cells. Transfections of rat adipose cells demonstrate that over-expression of wild-type NSF has no effect on total, or basal and insulin-stimulated cell-surface expression of HA-tagged GLUT4. In contrast, a dominant-negative NSF (NSF-D1EQ) can be expressed at a low enough level that it has little effect on total HA-GLUT4, but does reduce both basal and insulin-stimulated cell-surface HA-GLUT4 by ∼50% without affecting the GLUT4 fold-translocation response to insulin. However, high expression levels of NSF-D1EQ decrease total HA-GLUT4. The inhibitory effect of NSF-D1EQ on cell-surface HA-GLUT4 is reversed when endocytosis is inhibited by co-expression of a dominant-negative dynamin (dynamin-K44A). Moreover, NSF-D1EQ does not affect cell-surface levels of constitutively recycling GLUT1 and TfR, suggesting a predominant effect of low-level NSF-D1EQ on the trafficking of GLUT4 from the endocytic recycling compared to the intracellular GLUT4-specific compartment. Thus, our data demonstrate that the multiple fusion steps in GLUT4 trafficking have differential quantitative requirements for NSF activity. This indicates that the rates of plasma and intracellular membrane fusion reactions vary, leading to differential needs for the turnover of the SNARE proteins

  20. The GLUT4 density in slow fibres is not increased in athletes. How does training increase the GLUT4 pool originating from slow fibres?

    DEFF Research Database (Denmark)

    Gaster, M; Franch, J; Beck-Nielsen, H

    2001-01-01

    % of the fraction in the control group. Thus, GLUT4 originating from slow-twitch fibres was increased by 30% (Pincreases slow-twitch fibre GLUT4 expression by means of an elevated slow-twitch fibre mass in human skeletal muscle.......The influence of training on GLUT4 expression in slow- and fast-twitch skeletal muscle fibres was studied in male endurance-trained athletes and control subjects. The trained state was ensured by elevated maximal oxygen uptake (29%), as well as citrate synthase (60%) and 3-hydroxy......-acyl-CoA dehydrogenase (38%) activities in muscle biopsy samples of the vastus lateralis. GLUT4 densities in slow- and fast-twitch fibres were measured by the use of a newly developed, sensitive method combining immunohistochemistry with morphometry, and no effect of training was found. GLUT4 density was higher in slow...

  1. Role of insulin on exercise-induced GLUT-4 protein expression and glycogen supercompensation in rat skeletal muscle.

    Science.gov (United States)

    Kuo, Chia-Hua; Hwang, Hyonson; Lee, Man-Cheong; Castle, Arthur L; Ivy, John L

    2004-02-01

    The purpose of this study was to investigate the role of insulin on skeletal muscle GLUT-4 protein expression and glycogen storage after postexercise carbohydrate supplementation. Male Sprague-Dawley rats were randomly assigned to one of six treatment groups: sedentary control (Con), Con with streptozocin (Stz/C), immediately postexercise (Ex0), Ex0 with Stz (Stz/Ex0), 5-h postexercise (Ex5), and Ex5 with Stz (Stz/Ex5). Rats were exercised by swimming (2 bouts of 3 h) and carbohydrate supplemented immediately after each exercise session by glucose intubation (1 ml of a 50% wt/vol). Stz was administered 72-h before exercise, which resulted in hyperglycemia and elimination of the insulin response to the carbohydrate supplement. GLUT-4 protein of Ex0 rats was 30% above Con in fast-twitch (FT) red and 21% above Con in FT white muscle. In Ex5, GLUT-4 protein was 52% above Con in FT red and 47% above Con in FT white muscle. Muscle glycogen in FT red and white muscle was also increased above Con in Ex5 rats. Neither GLUT-4 protein nor muscle glycogen was increased above Con in Stz/Ex0 or Stz/Ex5 rats. GLUT-4 mRNA in FT red muscle of Ex0 rats was 61% above Con but only 33% above Con in Ex5 rats. GLUT-4 mRNA in FT red muscle of Stz/C and Stz/Ex0 rats was similar but significantly elevated in Ex5/Stz rats. These results suggest that insulin is essential for the increase in GLUT-4 protein expression following postexercise carbohydrate supplementation.

  2. Anti-Diabetic Activities of Jiaotaiwan in db/db Mice by Augmentation of AMPK Protein Activity and Upregulation of GLUT4 Expression

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    Na Hu

    2013-01-01

    Full Text Available Jiaotaiwan (JTW, which is composed of Coptis chinensis (CC and cinnamon (CIN, is one of the most well-known traditional Chinese medicines. In this study, we investigated the antidiabetic effects and mechanism of JTW in db/db mice. Results showed that JTW significantly decreased the level of fasting blood glucose and improved glucose and insulin tolerance better than CC or CIN alone. JTW also effectively protected the pancreatic islet shape, augmented the activation of AMP-activated protein kinase (AMPK in the liver, and increased the expression of glucose transporter 4 (GLUT4 protein in skeletal muscle and white fat. AMPK and GLUT4 contributed to glucose metabolism regulation and had an essential function in the development of diabetes mellitus (DM. Therefore, the mechanisms of JTW may be related to suppressing gluconeogenesis by activating AMPK in the liver and affecting glucose uptake in surrounding tissues through the upregulation of GLUT4 protein expression. These findings provided a new insight into the antidiabetic clinical applications of JTW and demonstrated the potential of JTW as a new drug candidate for DM treatment.

  3. The beneficial effects of exercise in rodents are preserved after detraining: a phenomenon unrelated to GLUT4 expression

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    De Angelis Kátia

    2010-10-01

    Full Text Available Abstract Background Although exercise training has well-known cardiorespiratory and metabolic benefits, low compliance with exercise training programs is a fact, and the harmful effects of physical detraining regarding these adaptations usually go unnoticed. We investigated the effects of exercise detraining on blood pressure, insulin sensitivity, and GLUT4 expression in spontaneously hypertensive rats (SHR and normotensive Wistar Kyoto rats (WKY. Methods Studied animals were randomized into sedentary, trained (treadmill running/5 days a week, 60 min/day for 10 weeks, 1 week of detraining, and 2 weeks of detraining. Blood pressure (tail-cuff system, insulin sensitivity (kITT, and GLUT4 (Western blot in heart, gastrocnemius and white fat tissue were measured. Results Exercise training reduced blood pressure (19%, improved insulin sensitivity (24%, and increased GLUT4 in the heart (+34%; gastrocnemius (+36% and fat (+22% in SHR. In WKY no change in either blood pressure or insulin sensitivity were observed, but there was an increase in GLUT4 in the heart (+25%, gastrocnemius (+45% and fat (+36% induced by training. Both periods of detraining did not induce any change in neither blood pressure nor insulin sensitivity in SHR and WKY. One-week detraining reduced GLUT4 in SHR (heart: -28%; fat: -23% and WKY (heart: -19%; fat: -22%; GLUT4 in the gastrocnemius was reduced after a 2-week detraining (SHR: -35%; WKY: -25%. There was a positive correlation between GLUT4 (gastrocnemius and the maximal velocity in the exercise test (r = 0.60, p = 0.004. Conclusions The study findings show that in detraining, despite reversion of the enhanced GLUT4 expression, cardiorespiratory and metabolic beneficial effects of exercise are preserved.

  4. Exploring the whereabouts of GLUT4 in skeletal muscle (review)

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Ralston, Evelyn

    2002-01-01

    related to GLUT4 storage compartments, trafficking to the surface membrane, and nature of the intracellular pools, have kept many groups busy for the past 20 years. Yet, one of the main questions in the field remains the universality of GLUT4 features. Can one extrapolate work done on fat cells to muscle......The glucose transporter GLUT4 is expressed in muscle, fat cells, brain and kidney. In contrast to other glucose transporters, GLUT4 in unstimulated cells is mostly intracellular. Stimuli such as insulin and muscle contractions then cause the translocation of GLUT4 to the cell surface. Questions...

  5. GLUT-1 expression and response to chemoradiotherapy in rectal cancer.

    LENUS (Irish Health Repository)

    Brophy, Sarah

    2009-12-15

    Preoperative chemoradiotherapy is used in locally advanced rectal cancer to reduce local recurrence and improve operability, however a proportion of tumors do not undergo significant regression. Identification of predictive markers of response to chemoradiotherapy would improve patient selection and may allow response modification by targeting of specific pathways. The aim of this study was to determine whether expression of glucose transporter-1 (GLUT-1) and p53 in pretreatment rectal cancer biopsies was predictive of tumor response to chemoradiotherapy. Immunohistochemical staining for GLUT-1 and p53 was performed on 69 pretreatment biopsies and compared to tumor response in the resected specimen as determined by the tumor regression grade (TRG) scoring system. GLUT-1 expression was significantly associated with reduced response to chemoradiotherapy and increasing GLUT expression correlated with poorer response (p=0.02). GLUT-1 negative tumors had a 70% probability of good response (TRG3\\/4) compared to a 31% probability of good response in GLUT-1 positive tumors. GLUT-1 may be a useful predictive marker of response to chemoradiotherapy in rectal cancer.

  6. Metabolically active CD4+ T cells expressing Glut1 and OX40 preferentially harbor HIV during in vitro infection.

    Science.gov (United States)

    Palmer, Clovis S; Duette, Gabriel A; Wagner, Marc C E; Henstridge, Darren C; Saleh, Suah; Pereira, Candida; Zhou, Jingling; Simar, David; Lewin, Sharon R; Ostrowski, Matias; McCune, Joseph M; Crowe, Suzanne M

    2017-10-01

    High glucose transporter 1 (Glut1) surface expression is associated with increased glycolytic activity in activated CD4+ T cells. Phosphatidylinositide 3-kinases (PI3K) activation measured by p-Akt and OX40 is elevated in CD4+Glut1+ T cells from HIV+ subjects. TCR engagement of CD4+Glut1+ T cells from HIV+ subjects demonstrates hyperresponsive PI3K-mammalian target of rapamycin signaling. High basal Glut1 and OX40 on CD4+ T cells from combination antiretroviral therapy (cART)-treated HIV+ patients represent a sufficiently metabolically active state permissive for HIV infection in vitro without external stimuli. The majority of CD4+OX40+ T cells express Glut1, thus OX40 rather than Glut1 itself may facilitate HIV infection. Furthermore, infection of CD4+ T cells is limited by p110γ PI3K inhibition. Modulating glucose metabolism may limit cellular activation and prevent residual HIV replication in 'virologically suppressed' cART-treated HIV+ persons. © 2017 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  7. GLUT4 in the endocrine pancreas--indicating an impact in pancreatic islet cell physiology?

    Science.gov (United States)

    Bähr, I; Bazwinsky-Wutschke, I; Wolgast, S; Hofmann, K; Streck, S; Mühlbauer, E; Wedekind, D; Peschke, E

    2012-06-01

    The glucose transporter GLUT4 is well known to facilitate the transport of blood glucose into insulin-sensitive muscle and adipose tissue. In this study, molecular, immunohistochemical, and Western blot investigations revealed evidence that GLUT4 is also located in the mouse, rat, and human endocrine pancreas. In addition, high glucose decreased and insulin elevated the GLUT4 expression in pancreatic α-cells. In contrast, high glucose increased GLUT4 expression, whereas insulin led to a reduced expression level of the glucose transporter in pancreatic β-cells. In vivo experiments showed that in pancreatic tissue of type 2 diabetic rats as well as type 2 diabetic patients, the GLUT4 expression is significantly increased compared to the nondiabetic control group. Furthermore, type 1 diabetic rats exhibited reduced GLUT4 transcript levels in pancreatic tissue, whereas insulin treatment of type 1 diabetic animals enhanced the GLUT4 expression back to control levels. These data provide evidence for the existence of GLUT4 in the endocrine pancreas and indicate a physiological relevance of this glucose transporter as well as characteristic changes in diabetic disease. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Effect of Papaya Seed Extract (Carica papaya Linn. on Glucose Transporter 4 (GLUT 4 Expression of Skeletal Muscle Tissue in Diabetic Mice Induced by High Fructose Diet

    Directory of Open Access Journals (Sweden)

    Devyani Diah Wulansari

    2017-08-01

    Full Text Available Ethnobotany surveys show that papaya seeds are widely used as herbs for the management of some diseases such as abdominal discomfort, pain, malaria, diabetes, obesity, and infection. This research was conducted to analyze the effect of papaya seed extract on GLUT4 expression on skeletal muscle tissue of DM type II model induced by high fructose diet. This study used 24 animals, divided into 4 groups of negative control group, treated with papaya seed extract 100 mg / kgBB, 200 mg / kgBW and 300 mg / kgBW, was adapted for 14 days then induced by fructose solution 20% Orally with a dose of 1.86 grams / kgBB for 56 days. The treatment group was given papaya seed extract in accordance with the dose of each group for 14 days. GDP levels was measured using a spectrophotometer. Skeletal muscle tissue is used on the gastrocnemius part. GLUT4 expression was measured through a Immunoreactive Score (IRS method with immunohistochemical staining using GLUT4 polyclonal antibodies. Comparative test results showed that there were significant differences between groups (p <0.05 in final GDP variables and GLUT4 expression. Pearson correlation test results show that the value p = 0.001, meaning there is a significant relationship between GLUT4 expression with final GDP levels. The result of simple linear regression analysis showed that p = 0,000 (<0,05, meaning that dose of papaya seed extract had a significant influence on GLUT4 expression.

  9. Cycle Training Increased GLUT4 and Activation of mTOR in Fast Twitch Muscle Fibers

    Science.gov (United States)

    Stuart, Charles A.; Howell, Mary E.A.; Baker, Jonathan D.; Dykes, Rhesa J.; Duffourc, Michelle M.; Ramsey, Michael W.; Stone, Michael H.

    2009-01-01

    Purpose To determine if cycle training of sedentary subjects would increase the expression of the principle muscle glucose transporters, six volunteers completed six weeks of progressively increasing intensity stationary cycle cycling. Methods In vastus lateralis muscle biopsies, changes in expression of GLUT1, GLUT4, GLUT5, and GLUT12 were compared using quantitative immunoblots with specific protein standards. Regulatory pathway components were evaluated by immunoblots of muscle homogenates and immunohistochemistry of microscopic sections. Results GLUT1 was unchanged, GLUT4 increased 66%, GLUT12 increased 104%, and GLUT5 decreased 72%. A mitochondrial marker (cytochrome c) and regulators of mitochondrial biogenesis (PGC-1α and phospho-AMPK) were unchanged, but the muscle hypertrophy pathway component, phospho-mTOR increased 83% after the exercise program. In baseline biopsies, GLUT4 by immunohistochemical techniques was 37% greater in Type I (slow twitch, red) muscle fibers, but the exercise training increased GLUT4 expression in Type II (fast twitch, white) fibers by 50%, achieving parity with the Type I fibers. Baseline phospho-mTOR expression was 50% higher in Type II fibers and increased more in Type II fibers (62%) with training, but also increased in Type I fibers (34%). Conclusion Progressive intensity stationary cycle training of previously sedentary subjects increased muscle insulin-responsive glucose transporters (GLUT4 and GLUT12) and decreased the fructose transporter (GLUT5). The increase in GLUT4 occurred primarily in Type II muscle fibers and this coincided with activation of the mTOR muscle hypertrophy pathway. There was little impact on Type I fiber GLUT4 expression and no evidence of change in mitochondrial biogenesis. PMID:20010125

  10. Expression of GLUT1 in stratified squamous epithelia and oral carcinoma from humans and rats

    DEFF Research Database (Denmark)

    Voldstedlund, M; Dabelsteen, Erik

    1997-01-01

    mucosa from rat and man, and a human oral carcinoma by indirect immunofluorescence microscopy. The results showed that GLUT1 was expressed in the basal and parabasal layers of the different stratified squamous epithelia, with some variations between keratinized and non-keratinized subtypes. GLUT1...... was also expressed in ductal- and myoepithelial cells of minor salivary glands and perineural sheath located in the lamina propra, and furthermore in the cells of an oral carcinoma. GLUT4 was not expressed in any of the tissues examined. This distribution of GLUT1 does not fit with the idea of GLUT1......Most cells express facilitative glucose transporters. Four isoforms (GLUT1-4) transporting D-glucose across the plasma membrane show a specific tissue distribution, which is the basis for tissue-specific patterns in glucose metabolism. GLUT1 is expressed at high levels in tissue barriers...

  11. An intracellular motif of GLUT4 regulates fusion of GLUT4-containing vesicles.

    Science.gov (United States)

    Heyward, Catherine A; Pettitt, Trevor R; Leney, Sophie E; Welsh, Gavin I; Tavaré, Jeremy M; Wakelam, Michael J O

    2008-05-20

    Insulin stimulates glucose uptake by adipocytes through increasing translocation of the glucose transporter GLUT4 from an intracellular compartment to the plasma membrane. Fusion of GLUT4-containing vesicles at the cell surface is thought to involve phospholipase D activity, generating the signalling lipid phosphatidic acid, although the mechanism of action is not yet clear. Here we report the identification of a putative phosphatidic acid-binding motif in a GLUT4 intracellular loop. Mutation of this motif causes a decrease in the insulin-induced exposure of GLUT4 at the cell surface of 3T3-L1 adipocytes via an effect on vesicle fusion. The potential phosphatidic acid-binding motif identified in this study is unique to GLUT4 among the sugar transporters, therefore this motif may provide a unique mechanism for regulating insulin-induced translocation by phospholipase D signalling.

  12. An intracellular motif of GLUT4 regulates fusion of GLUT4-containing vesicles

    Directory of Open Access Journals (Sweden)

    Welsh Gavin I

    2008-05-01

    Full Text Available Abstract Background Insulin stimulates glucose uptake by adipocytes through increasing translocation of the glucose transporter GLUT4 from an intracellular compartment to the plasma membrane. Fusion of GLUT4-containing vesicles at the cell surface is thought to involve phospholipase D activity, generating the signalling lipid phosphatidic acid, although the mechanism of action is not yet clear. Results Here we report the identification of a putative phosphatidic acid-binding motif in a GLUT4 intracellular loop. Mutation of this motif causes a decrease in the insulin-induced exposure of GLUT4 at the cell surface of 3T3-L1 adipocytes via an effect on vesicle fusion. Conclusion The potential phosphatidic acid-binding motif identified in this study is unique to GLUT4 among the sugar transporters, therefore this motif may provide a unique mechanism for regulating insulin-induced translocation by phospholipase D signalling.

  13. The Effect of a High-Protein Diet and Exercise on Cardiac AQP7 and GLUT4 Gene Expression.

    Science.gov (United States)

    Palabiyik, Orkide; Karaca, Aziz; Taştekin, Ebru; Yamasan, Bilge Eren; Tokuç, Burcu; Sipahi, Tammam; Vardar, Selma Arzu

    2016-10-01

    High-protein (HP) diets are commonly consumed by athletes despite their potential health hazard, which is postulated to enforce a negative effect on bone and renal health. However, its effects on heart have not been known yet. Aquaporin-7 (AQP7) is an aquaglyceroporin that facilitates glycerol and water transport. Glycerol is an important cardiac energy production substrate, especially during exercise, in conjunction with fatty acids and glucose. Glucose transporter 4 (GLUT4) is an insulin-sensitive glucose transporter in heart. We aimed to investigate the effect of HPD on AQP7 and GLUT4 levels in the rat heart subjected to exercise. Male Sprague-Dawley rats were divided into control (n = 12), exercise (E) training (n = 10), HPD (n = 12), and HPD-E training (n = 9) groups. The HPD groups were fed a 45 % protein-containing diet 5 weeks. The HPD-E and E groups were performed the treadmill exercise during the 5-week study period. Real-time polymerase chain reaction and immunohistochemistry techniques were used to determine the gene expression and localization of AQP7 and GLUT4 in heart tissue. Results of relative gene expression were calculated by the 'Pfaffl' mathematical method using the REST program. Differences in AQP7 and GLUT4 gene expression were expressed as fold change compared to the control group. Heart weight/tibia ratio and ventricular wall thickness were evaluated as markers of cardiac hypertrophy. Further, serum glucose, glycerol, and insulin levels were also measured. AQP7 gene expression was found to be increased in the E (3.47-fold, p protein expression was also increased in the HPD and HPD-E groups (p protein expression was significantly increased in the E, HPD, and HPD-E groups compared to the control group (p = 0.024, p protein diet groups (C and E). Serum insulin levels were higher for HPD groups compared with the normal-protein diet groups (p < 0.001), whereas no differences were observed between the exercise and sedentary

  14. Expressions of IGF-1, ERK, GLUT4, IRS-1 in metabolic syndrome complicated with colorectal cancer and their associations with the clinical characteristics of CRC.

    Science.gov (United States)

    Hu, Jianxia; Liu, Xiaoyi; Chi, Jingwei; Che, Kui; Feng, Yan; Zhao, Shihua; Wang, Zhongchao; Wang, Yangang

    2018-01-01

    Epidemiological data have revealed that colorectal cancer (CRC) risk is increased in patients with Metabolic syndrome. To explore the expressions of IGF-1, ERK, GLUT4, IRS-1 in MS patients with CRC and their associations with the clinical characteristics of CRC. We investigated the expressions of IGF-1, ERK, GLUT4 and IRS-1 in greater omental adipose tissues of 168 MS patients with/without CRC, 85 CRC patients without MS and 98 healthy controls by RT-PCR, and analyzed the relationships between their expressions and clinical characteristics of CRC. The expression levels of IGF-1 and ERK in MS patients with/without CRC were higher while the expression levels of GLUT4 were lower compared with CRC patients without MS and healthy controls (PCRC were higher while expression levels of GLUT4 were lower compared to MS patients without CRC (PCRC, including tumor size, distant metastasis and advanced stages (III/IV) (PCRC.

  15. Expression of Glut-1 and Glut-3 in untreated oral squamous cell carcinoma compared with FDG accumulation in a PET study

    International Nuclear Information System (INIS)

    Tian, Mei; Endo, Keigo; Zhang, Hong; Nakasone, Yoshiki; Mogi, Kenji

    2004-01-01

    Increased expression of glucose transporter-1 (Glut-1) and glucose transporter-3 (Glut-3) has been reported in many human cancers. The mechanism of glucose entry into oral squamous cell carcinoma (OSCC) remains unclear. In this study we investigated, in untreated human OSCC, the relationship between tumour fluorine-18 fluoro-2-deoxy-d-glucose (FDG) accumulation and the expression of Glut-1 and Glut-3, as well as the association between the expression of Glut-1 and of Glut-3. All patients underwent FDG positron emission tomography (PET) pre-operatively. Standardised uptake values (SUVs) were used for evaluation of tumour FDG uptake. Final diagnoses were established by histology. Immunohistochemical staining results were evaluated according to the percentage (%) of positive area, intensity and staining score. Tumour sections were stained by immunohistochemistry for Glut-1 and Glut-3. Glut-1 immunostaining revealed that 18 (94.7%) of the 19 tumours stained positively, while Glut-3 immunostaining yielded positive findings for 16 (84.2%) tumours. Overall, a relatively low level of agreement (36.8%) in the staining score was observed between Glut-1 and Glut-3 expression. No relationship was found between the staining pattern and tumour differentiation or T grade classification in either Glut-1 or Glut-3 immunostaining. Furthermore, no relationship was found between increased FDG SUV and tumour differentiation, but the former did correlate with T grade. In conclusion, high FDG uptake values were seen in OSCC with overexpression of Glut-1 and Glut-3. However, no significant correlation was found between FDG SUV and Glut-1 or Glut-3 expression. (orig.)

  16. Soybean and sunflower oil-induced insulin resistance correlates with impaired GLUT4 protein expression and translocation specifically in white adipose tissue.

    Science.gov (United States)

    Poletto, Ana Cláudia; Anhê, Gabriel Forato; Eichler, Paula; Takahashi, Hilton Kenji; Furuya, Daniela Tomie; Okamoto, Maristela Mitiko; Curi, Rui; Machado, Ubiratan Fabres

    2010-03-01

    Free fatty acids are known for playing a crucial role in the development of insulin resistance. High fat intake is known for impairing insulin sensitivity; however, the effect of vegetable-oil injections have never been investigated. The present study investigated the effects of daily subcutaneous injections (100 microL) of soybean (SB) and sunflower (SF) oils, during 7 days. Both treated groups developed insulin resistance as assessed by insulin tolerance test. The mechanism underlying the SB- and SF-induced insulin resistance was shown to involve GLUT4. In SB- and SF-treated animals, the GLUT4 protein expression was reduced approximately 20% and 10 min after an acute in vivo stimulus with insulin, the plasma membrane GLUT4 content was approximately 60% lower in white adipose tissue (WAT). No effects were observed in skeletal muscle. Additionally, both oil treatments increased mainly the content of palmitic acid ( approximately 150%) in WAT, which can contribute to explain the GLUT4 regulations. Altogether, the present study collects evidence that those oil treatments might generate insulin resistance by targeting GLUT4 expression and translocation specifically in WAT. These alterations are likely to be caused due to the specific local increase in saturated fatty acids that occurred as a consequence of oil daily injections. 2010 John Wiley & Sons, Ltd.

  17. PKC and Rab13 mediate Ca2+ signal-regulated GLUT4 traffic.

    Science.gov (United States)

    Deng, Bangli; Zhu, Xiaocui; Zhao, Yihe; Zhang, Da; Pannu, Alisha; Chen, Liming; Niu, Wenyan

    2018-01-08

    Exercise/muscle contraction increases cell surface glucose transporter 4 (GLUT4), leading to glucose uptake to regulate blood glucose level. Elevating cytosolic Ca 2+ mediates this effect, but the detailed mechanism is not clear yet. We used calcium ionophore ionomycin to raise intracellular cytosolic Ca 2+ level to explore the underlying mechanism. We showed that in L6 myoblast muscle cells stably expressing GLUT4myc, ionomycin increased cell surface GLUT4myc levels and the phosphorylation of AS160, TBC1D1. siPKCα and siPKCθ but not siPKCδ and siPKCε inhibited the ionomycin-increased cell surface GLUT4myc level. siPKCα, siPKCθ inhibited the phosphorylation of AS160 and TBC1D1 induced by ionomycin. siPKCα and siPKCθ prevented ionomycin-inhibited endocytosis of GLUT4myc. siPKCθ, but not siPKCα inhibited ionomycin-stimulated exocytosis of GLUT4myc. siRab13 but not siRab8a, siRab10 and siRab14 inhibited the exocytosis of GLUT4myc promoted by ionomycin. In summary, ionomycin-promoted exocytosis of GLUT4 is partly reversed by siPKCθ, whereas ionomycin-inhibited endocytosis of GLUT4 requires both siPKCα and siPKCθ. PKCα and PKCθ contribute to ionomycin-induced phosphorylation of AS160 and TBC1D1. Rab13 is required for ionomycin-regulated GLUT4 exocytosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Neonatal hypothyroidism affects testicular glucose homeostasis through increased oxidative stress in prepubertal mice: effects on GLUT3, GLUT8 and Cx43.

    Science.gov (United States)

    Sarkar, D; Singh, S K

    2017-07-01

    Thyroid hormones (THs) play an important role in maintaining the link between metabolism and reproduction and the altered THs status is associated with induction of oxidative stress in various organs like brain, heart, liver and testis. Further, reactive oxygen species play a pivotal role in regulation of glucose homeostasis in several organs, and glucose utilization by Leydig cells is essential for testosterone biosynthesis and thus is largely dependent on glucose transporter 8 (GLUT8). Glucose uptake by Sertoli cells is mediated through glucose transporter 3 (GLUT3) under the influence of THs to meet energy requirement of developing germ cells. THs also modulate level of gap junctional protein such as connexin 43 (Cx43), a potential regulator of cell proliferation and apoptosis in the seminiferous epithelium. Although the role of transient neonatal hypothyroidism in adult testis in terms of testosterone production is well documented, the effect of THs deficiency in early developmental period and its role in testicular glucose homeostasis and oxidative stress with reference to Cx43 in immature mice remain unknown. Therefore, the present study was conducted to evaluate the effect of neonatal hypothyroidism on testicular glucose homeostasis and oxidative stress at postnatal days (PND) 21 and 28 in relation to GLUT3, GLUT8 and Cx43. Hypothyroidism induced by 6-propyl-2-thiouracil (PTU) markedly decreased testicular glucose level with considerable reduction in expression level of GLUT3 and GLUT8. Likewise, lactate dehydrogenase (LDH) activity and intratesticular concentration of lactate were also decreased in hypothyroid mice. There was also a rise in germ cell apoptosis with increased expression of caspase-3 in PTU-treated mice. Further, neonatal hypothyroidism affected germ cell proliferation with decreased expression of proliferating cell nuclear antigen (PCNA) and Cx43. In conclusion, our results suggest that neonatal hypothyroidism alters testicular glucose

  19. Insulin and leptin induce Glut4 plasma membrane translocation and glucose uptake in a human neuronal cell line by a phosphatidylinositol 3-kinase- dependent mechanism.

    Science.gov (United States)

    Benomar, Yacir; Naour, Nadia; Aubourg, Alain; Bailleux, Virginie; Gertler, Arieh; Djiane, Jean; Guerre-Millo, Michèle; Taouis, Mohammed

    2006-05-01

    The insulin-sensitive glucose transporter Glut4 is expressed in brain areas that regulate energy homeostasis and body adiposity. In contrast with peripheral tissues, however, the impact of insulin on Glut4 plasma membrane (PM) translocation in neurons is not known. In this study, we examined the role of two anorexic hormones (leptin and insulin) on Glut4 translocation in a human neuronal cell line that express endogenous insulin and leptin receptors. We show that insulin and leptin both induce Glut4 translocation to the PM of neuronal cells and activate glucose uptake. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase, totally abolished insulin- and leptin-dependent Glut4 translocation and stimulation of glucose uptake. Thus, Glut4 translocation is a phosphatidylinositol 3-kinase-dependent mechanism in neuronal cells. Next, we investigated the impact of chronic insulin and leptin treatments on Glut4 expression and translocation. Chronic exposure of neuronal cells to insulin or leptin down-regulates Glut4 proteins and mRNA levels and abolishes the acute stimulation of glucose uptake in response to acute insulin or leptin. In addition, chronic treatment with either insulin or leptin impaired Glut4 translocation. A cross-desensitization between insulin and leptin was apparent, where exposure to insulin affects leptin-dependent Glut4 translocation and vice versa. This cross-desensitization could be attributed to the increase in suppressor of cytokine signaling-3 expression, which was demonstrated in response to each hormone. These results provide evidence to suggest that Glut4 translocation to neuronal PM is regulated by both insulin and leptin signaling pathways. These pathways might contribute to an in vivo glucoregulatory reflex involving a neuronal network and to the anorectic effect of insulin and leptin.

  20. PGC-1{alpha} is required for AICAR induced expression of GLUT4 and mitochondrial proteins in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Leick, Lotte; Fentz, Joachim; Biensø, Rasmus S

    2010-01-01

    We tested the hypothesis that repeated activation of AMPK induces mitochondrial and glucose membrane transporter gene/protein expression via a peroxisome proliferator activated receptor Upsilon co-activator (PGC)-1alpha dependent mechanism. Whole body PGC-1alpha knockout (KO) and littermate wild...... GLUT4, cytochrome c oxidase (COX)I and cytochrome (cyt) c protein expression ~10-40% relative to saline in white muscles of the WT mice, but not of the PGC-1alpha KO mice. In line, GLUT4 and cyt c mRNA content increased 30-60% 4h after a single AICAR injection relative to saline only in WT mice. One...... and PGC-1alpha KO mice. In conclusion, we here provide genetic evidence for a major role of PGC-1alpha in AMPK mediated regulation of mitochondrial and glucose membrane transport protein expression in skeletal muscle....

  1. GLUT4 expression in human muscle fibres is not correlated with intracellular triglyceride (TG) content. Is TG a maker or a marker of insulin resistance?

    DEFF Research Database (Denmark)

    Gaster, M; Ottosen, P D; Vach, W

    2003-01-01

    diabetic subjects, and young lean controls. TG density was significantly higher in slow compared to fast fibres in all studied subjects (pslow twitch fibres of obese diabetic subjects compared to obese (p...We have recently reported a progressive decline in the expression of glucose transporter isoform 4 (GLUT4) from control subjects through obese non-diabetics to obese type 2 diabetic subjects, indicating that the reduced GLUT4 in slow twitch fibres could be secondary to obesity. In this study we...... densities in slow and fast fibres did not correlate with the corresponding GLUT4 density in the same fibres in our study groups (p>0.05). Plasma TG and FFA did not correlate with GLUT4 expression in slow or fast fibres (p>0.05). In conclusion, TG content was increased in diabetic slow fibres with a reduced...

  2. Glucose rapidly decreases plasma membrane GLUT4 content in rat skeletal muscle.

    Science.gov (United States)

    Marette, A; Dimitrakoudis, D; Shi, Q; Rodgers, C D; Klip, A; Vranic, M

    1999-02-01

    We have previously demonstrated that chronic hyperglycemia per se decreases GLUT4 glucose transporter expression and plasma membrane content in mildly streptozotocin- (STZ) diabetic rats (Biochem. J. 284, 341-348, 1992). In the present study, we investigated the effect of an acute rise in glycemia on muscle GLUT4 and GLUT1 protein contents in the plasma membrane, in the absence of insulin elevation. Four experimental groups of rats were analyzed in the postabsorptive state: 1. Control rats. 2. Hyperglycemic STZ-diabetic rats with moderately reduced fasting insulin levels. 3. STZ-diabetic rats made normoglycemic with phlorizin treatment. 4. Phlorizin-treated (normoglycemic) STZ-diabetic rats infused with glucose for 40 min. The uniqueness of the latter model is that glycemia can be rapidly raised without any concomitant increase in plasma insulin levels. Plasma membranes were isolated from hindlimb muscle and GLUT1 and GLUT4 proteins amounts determined by Western blot analysis. As predicted, STZ-diabetes caused a significant decrease in the abundance of GLUT4 in the isolated plasma membranes. Normalization of glycemia for 3 d with phlorizin treatment restored plasma membrane GLUT4 content in muscle of STZ-diabetic rats. A sudden rise in glycemia over a period of 40 min caused the GLUT4 levels in the plasma membrane fraction to decrease to those of nontreated STZ-diabetic rats. In contrast to the GLUT4 transporter, plasma membrane GLUT1 abundance was not changed by the acute glucose challenge. It is concluded that glucose can have regulatory effect by acutely reducing plasma membrane GLUT4 protein contents in rat skeletal muscle. We hypothesize that this glucose-induced downregulation of plasma membrane GLUT4 could represent a protective mechanism against excessive glucose uptake under hyperglycemic conditions accompanied by insulin resistance.

  3. Sulfonylurea therapy improves glucose disposal without changing skeletal muscle GLUT4 levels in noninsulin-dependent diabetes mellitus subjects

    DEFF Research Database (Denmark)

    Vestergaard, H; Weinreb, J E; Rosen, A S

    1995-01-01

    alteration in GLUT4 levels expressed either per microgram membrane protein or per DNA. In summary, the improvement in glycemic control and glucose disposal in NIDDM subjects receiving gliclazide therapy cannot be explained by increased expression of GLUT4 in muscle. Thus, therapeutic effects on insulin......A major pathological feature of noninsulin-dependent diabetes (NIDDM) is defective insulin-stimulated glucose transport in skeletal muscle. When NIDDM subjects are assessed as a group, GLUT4 gene expression in skeletal muscle varies widely and is not different from that in controls. Thus......, longitudinal studies are needed to assess whether changes in GLUT4 expression in muscle of NIDDM subjects could be responsible for changes in glucose disposal. The question is timely because recent studies in transgenic mice show that increasing GLUT4 expression can increase insulin-stimulated glucose uptake...

  4. Impaired translocation of GLUT4 results in insulin resistance of atrophic soleus muscle.

    Science.gov (United States)

    Xu, Peng-Tao; Song, Zhen; Zhang, Wen-Cheng; Jiao, Bo; Yu, Zhi-Bin

    2015-01-01

    Whether or not the atrophic skeletal muscle induces insulin resistance and its mechanisms are not resolved now. The antigravity soleus muscle showed a progressive atrophy in 1-week, 2-week, and 4-week tail-suspended rats. Hyperinsulinemic-euglycemic clamp showed that the steady-state glucose infusion rate was lower in 4-week tail-suspended rats than that in the control rats. The glucose uptake rates under insulin- or contraction-stimulation were significantly decreased in 4-week unloaded soleus muscle. The key protein expressions of IRS-1, PI3K, and Akt on the insulin-dependent pathway and of AMPK, ERK, and p38 on the insulin-independent pathway were unchanged in unloaded soleus muscle. The unchanged phosphorylation of Akt and p38 suggested that the activity of two signal pathways was not altered in unloaded soleus muscle. The AS160 and GLUT4 expression on the common downstream pathway also was not changed in unloaded soleus muscle. But the GLUT4 translocation to sarcolemma was inhibited during insulin stimulation in unloaded soleus muscle. The above results suggest that hindlimb unloading in tail-suspended rat induces atrophy in antigravity soleus muscle. The impaired GLUT4 translocation to sarcolemma under insulin stimulation may mediate insulin resistance in unloaded soleus muscle and further affect the insulin sensitivity of whole body in tail-suspended rats.

  5. Impaired Translocation of GLUT4 Results in Insulin Resistance of Atrophic Soleus Muscle

    Directory of Open Access Journals (Sweden)

    Peng-Tao Xu

    2015-01-01

    Full Text Available Whether or not the atrophic skeletal muscle induces insulin resistance and its mechanisms are not resolved now. The antigravity soleus muscle showed a progressive atrophy in 1-week, 2-week, and 4-week tail-suspended rats. Hyperinsulinemic-euglycemic clamp showed that the steady-state glucose infusion rate was lower in 4-week tail-suspended rats than that in the control rats. The glucose uptake rates under insulin- or contraction-stimulation were significantly decreased in 4-week unloaded soleus muscle. The key protein expressions of IRS-1, PI3K, and Akt on the insulin-dependent pathway and of AMPK, ERK, and p38 on the insulin-independent pathway were unchanged in unloaded soleus muscle. The unchanged phosphorylation of Akt and p38 suggested that the activity of two signal pathways was not altered in unloaded soleus muscle. The AS160 and GLUT4 expression on the common downstream pathway also was not changed in unloaded soleus muscle. But the GLUT4 translocation to sarcolemma was inhibited during insulin stimulation in unloaded soleus muscle. The above results suggest that hindlimb unloading in tail-suspended rat induces atrophy in antigravity soleus muscle. The impaired GLUT4 translocation to sarcolemma under insulin stimulation may mediate insulin resistance in unloaded soleus muscle and further affect the insulin sensitivity of whole body in tail-suspended rats.

  6. Loss of sugar detection by GLUT2 affects glucose homeostasis in mice.

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    Emilie Stolarczyk

    Full Text Available BACKGROUND: Mammals must sense the amount of sugar available to them and respond appropriately. For many years attention has focused on intracellular glucose sensing derived from glucose metabolism. Here, we studied the detection of extracellular glucose concentrations in vivo by invalidating the transduction pathway downstream from the transporter-detector GLUT2 and measured the physiological impact of this pathway. METHODOLOGY/PRINCIPAL FINDINGS: We produced mice that ubiquitously express the largest cytoplasmic loop of GLUT2, blocking glucose-mediated gene expression in vitro without affecting glucose metabolism. Impairment of GLUT2-mediated sugar detection transiently protected transgenic mice against starvation and streptozotocin-induced diabetes, suggesting that both low- and high-glucose concentrations were not detected. Transgenic mice favored lipid oxidation, and oral glucose was slowly cleared from blood due to low insulin production, despite massive urinary glucose excretion. Kidney adaptation was characterized by a lower rate of glucose reabsorption, whereas pancreatic adaptation was associated with a larger number of small islets. CONCLUSIONS/SIGNIFICANCE: Molecular invalidation of sugar sensing in GLUT2-loop transgenic mice changed multiple aspects of glucose homeostasis, highlighting by a top-down approach, the role of membrane glucose receptors as potential therapeutic targets.

  7. Humanin (HN and glucose transporter 8 (GLUT8 in pregnancies complicated by intrauterine growth restriction.

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    Carla Janzen

    Full Text Available Intrauterine growth restriction (IUGR results from a lack of nutrients transferred to the developing fetus, particularly oxygen and glucose. Increased expression of the cytoprotective mitochondrial peptide, humanin (HN, and the glucose transporter 8, GLUT8, has been reported under conditions of hypoxic stress. However, the presence and cellular localization of HN and GLUT8 in IUGR-related placental pathology remain unexplored. Thus, we undertook this study to investigate placental expression of HN and GLUT8 in IUGR-affected versus normal pregnancies.We found 1 increased HN expression in human IUGR-affected pregnancies on the maternal aspect of the placenta (extravillous trophoblastic (EVT cytoplasm compared to control (i.e. appropriate for gestational age pregnancies, and a concomitant increase in GLUT8 expression in the same compartment, 2 HN and GLUT8 showed a protein-protein interaction by co-immunoprecipitation, 3 elevated HN and GLUT8 levels in vitro under simulated hypoxia in human EVT cells, HTR8/SVneo, and 4 increased HN expression but attenuated GLUT8 expression in vitro under serum deprivation in HTR8/SVneo cells.There was elevated HN expression with cytoplasmic localization to EVTs on the maternal aspect of the human placenta affected by IUGR, also associated with increased GLUT8 expression. We found that while hypoxia increased both HN and GLUT8, serum deprivation increased HN expression alone. Also, a protein-protein interaction between HN and GLUT8 suggests that their interaction may fulfill a biologic role that requires interdependency. Future investigations delineating molecular interactions between these proteins are required to fully uncover their role in IUGR-affected pregnancies.

  8. Estradiol-induced regulation of GLUT4 in 3T3-L1 cells: involvement of ESR1 and AKT activation.

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    Campello, Raquel S; Fátima, Luciana A; Barreto-Andrade, João Nilton; Lucas, Thais F; Mori, Rosana C; Porto, Catarina S; Machado, Ubiratan F

    2017-10-01

    Impaired insulin-stimulated glucose uptake involves reduced expression of the GLUT4 (solute carrier family 2 facilitated glucose transporter member 4, SLC2A4 gene). 17β-estradiol (E 2 ) modulates SLC2A4 /GLUT4 expression, but the involved mechanisms are unclear. Although E 2 exerts biological effects by binding to estrogen receptors 1/2 (ESR1/2), which are nuclear transcriptional factors; extranuclear effects have also been proposed. We hypothesize that E 2 regulates GLUT4 through an extranuclear ESR1 mechanism. Thus, we investigated the effects of E 2 upon (1) subcellular distribution of ESRs and the proto-oncogene tyrosine-protein kinases (SRC) involvement; (2) serine/threonine-protein kinase (AKT) activation; (3) Slc2a4 /GLUT4 expression and (4) GLUT4 subcellular distribution and glucose uptake in 3T3-L1 adipocytes. Differentiated 3T3-L1 adipocytes were cultivated or not with E 2 for 24 h, and additionally treated or not with ESR1-selective agonist (PPT), ESR1-selective antagonist (MPP) or selective SRC inhibitor (PP2). Subcellular distribution of ESR1, ESR2 and GLUT4 was analyzed by immunocytochemistry; Slc2a4 mRNA and GLUT4 were quantified by qPCR and Western blotting, respectively; plasma membrane GLUT4 translocation and glucose uptake were analyzed under insulin stimulus for 20 min or not. E 2 induced (1) translocation of ESR1, but not of ESR2, from nucleus to plasma membrane and AKT phosphorylation, effects mimicked by PPT and blocked by MPP and PP2; (2) increased Slc2a4 /GLUT4 expression and (3) increased insulin-stimulated GLUT4 translocation and glucose uptake. In conclusion, E 2 treatment promoted a SRC-mediated nucleus-plasma membrane shuttle of ESR1, and increased AKT phosphorylation, Slc2a4 /GLUT4 expression and plasma membrane GLUT4 translocation; consequently, improving insulin-stimulated glucose uptake. These results unravel mechanisms through which estrogen improves insulin sensitivity. © 2017 Society for Endocrinology.

  9. Expression of Akt and GLUT-4 in adipose tissue of women with gestational diabetes mellitus and pregnant women with excessive weight gain

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    Li WU

    2014-10-01

    Full Text Available Objective To investigate the influence of glucose transporter 4 (GLUT-4 and protein kinase B (Akt on gestational diabetes mellitus (GDM by determining their expressions in adipose tissues from women with GDM, excessive weight gain pregnant women, and normal pregnant women. Methods Adipose tissues were obtained by biopsy during cesarean section from 15 pregnant women with normal glucose tolerance while their body mass index (BMI increased in about 4kg/m2 (NGT1 group, and 15 pregnant women with normal glucose tolerance with BMI increased by 8kg/m2 (NGT2 group, and 15 cases of GDM (GDM group. Adipose tissue were divided into two sections and incubated in the culture medium with or without insulin (1×10-7 mol/L for 30 minutes. Fasting blood glucose (FBG and fasting insulin (FINS levels were determined with glucose oxidase and radioimmunoassay. Homeostatic model assessment of insulin resistance (HOMA-IR, and homeostatic model assessment of insulin secretions index (HOMA-IS were calculated from the data. Phosphorylation of Akt (P-Akt and GLUT-4 levels of cultured adipose tissue were examined by Western blotting. Results The FBG levels were similar in 3 groups. FINS, HOMA-IR and HOMA-IS were significantly different among the 3 groups (P0.05 in basal state. Compared with the basal state, however, the phosphorylation of Akt increased significantly in NGT1 group (P0.05 after insulin stimulation. The expression of GLUT-4 was significantly lower in GDM group and NGT2 group than in NGT1 group (P<0.05 in basal state. The expression of GLUT-4 increased much more in NGT1 group than in NGT2 group or GDM group (P<0.05 after insulin stimulation. Conclusion The excessive weight gain and normal glucose tolerance pregnant women almost share a similar expression with GDM women in the insulin signaling and glucose transporter proteins, Akt and GLUT-4, and their abnormal expression and function might play an important role in insulin resistance and GDM

  10. Super-resolution microscopy reveals the insulin-resistance-regulated reorganization of GLUT4 on plasma membranes.

    Science.gov (United States)

    Gao, Lan; Chen, Junling; Gao, Jing; Wang, Hongda; Xiong, Wenyong

    2017-01-15

    GLUT4 (also known as SLC2A4) is essential for glucose uptake in skeletal muscles and adipocytes, which play central roles in whole-body glucose metabolism. Here, using direct stochastic optical reconstruction microscopy (dSTORM) to investigate the characteristics of plasma-membrane-fused GLUT4 at the single-molecule level, we have demonstrated that insulin and insulin resistance regulate the spatial organization of GLUT4 in adipocytes. Stimulation with insulin shifted the balance of GLUT4 on the plasma membrane toward a more dispersed configuration. In contrast, insulin resistance induced a more clustered distribution of GLUT4 and increased the mean number of molecules per cluster. Furthermore, our data demonstrate that the F 5 QQI motif and lipid rafts mediate the maintenance of GLUT4 clusters on the plasma membrane. Mutation of F 5 QQI (F 5 QQA-GLUT4) induced a more clustered distribution of GLUT4; moreover, destruction of lipid rafts in adipocytes expressing F 5 QQA-GLUT4 dramatically decreased the percentage of large clusters and the mean number of molecules per cluster. In conclusion, our data clarify the effects of insulin stimulation or insulin resistance on GLUT4 reorganization on the plasma membrane and reveal new pathogenic mechanisms of insulin resistance. © 2017. Published by The Company of Biologists Ltd.

  11. Diabetes-Resistant NOR Mice Are More Severely Affected by Streptozotocin Compared to the Diabetes-Prone NOD Mice: Correlations with Liver and Kidney GLUT2 Expressions

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    S. Kahraman

    2015-01-01

    Full Text Available Nonobese Diabetic (NOD mice are susceptible strains for Type 1 diabetes development, and Nonobese Diabetes-Resistant (NOR mice are defined as suitable controls for NOD mice in non-MHC-related research. Diabetes is often accelerated in NOD mice via Streptozotocin (STZ. STZ is taken inside cells via GLUT2 transmembrane carrier proteins, the major glucose transporter isoforms in pancreatic beta cells, liver, kidneys, and the small intestine. We observed severe adverse effects in NOR mice treated with STZ compared to NOD mice that were made diabetic with a similar dose. We suggested that the underlying mechanism could be differential GLUT2 expressions in pancreatic beta cells, yet immunofluorescent and immunohistochemical studies revealed similar GLUT2 expression levels. We also detected GLUT2 expression profiles in NOD and NOR hepatic and renal tissues by western blot analysis and observed considerably higher GLUT2 expression levels in liver and kidney tissues of NOR mice. Although beta cell GLUT2 expression levels are frequently evaluated as a marker predicting STZ sensitivity in animal models, we report here very different diabetic responses to STZ in two different animal strains, in spite of similar initial GLUT2 expressions in beta cells. Furthermore, use of NOR mice in STZ-mediated experimental diabetes settings should be considered accordingly.

  12. Leptin Reduces the Expression and Increases the Phosphorylation of the Negative Regulators of GLUT4 Traffic TBC1D1 and TBC1D4 in Muscle of ob/ob Mice

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    Sáinz, Neira; Rodríguez, Amaia; Catalán, Victoria; Becerril, Sara; Ramírez, Beatriz; Lancha, Andoni; Burgos-Ramos, Emma; Gómez-Ambrosi, Javier; Frühbeck, Gema

    2012-01-01

    Leptin improves insulin sensitivity in skeletal muscle. Our goal was to determine whether proteins controlling GLUT4 traffic are altered by leptin deficiency and in vivo leptin administration in skeletal muscle of wild type and ob/ob mice. Leptin-deficient ob/ob mice were divided in three groups: control, leptin-treated (1 mg/kg/d) and leptin pair-fed ob/ob mice. Microarray analysis revealed that 1,546 and 1,127 genes were regulated by leptin deficiency and leptin treatment, respectively. Among these, we identified 24 genes involved in intracellular vesicle-mediated transport in ob/ob mice. TBC1 domain family, member 1 (Tbc1d1), a negative regulator of GLUT4 translocation, was up-regulated (P = 0.001) in ob/ob mice as compared to wild types. Importantly, leptin treatment reduced the transcript levels of Tbc1d1 (P<0.001) and Tbc1d4 (P = 0.004) in the leptin-treated ob/ob as compared to pair-fed ob/ob animals. In addition, phosphorylation levels of TBC1D1 and TBC1D4 were enhanced in leptin-treated ob/ob as compared to control ob/ob (P = 0.015 and P = 0.023, respectively) and pair-fed ob/ob (P = 0.036 and P = 0.034, respectively) mice. Despite similar GLUT4 protein expression in wild type and ob/ob groups a different immunolocalization of this protein was evidenced in muscle sections. Leptin treatment increased GLUT4 immunoreactivity in gastrocnemius and extensor digitorum longus sections of leptin-treated ob/ob mice. Moreover, GLUT4 protein detected in immunoprecipitates from TBC1D4 was reduced by leptin replacement compared to control ob/ob (P = 0.013) and pair-fed ob/ob (P = 0.037) mice. Our findings suggest that leptin enhances the intracellular GLUT4 transport in skeletal muscle of ob/ob animals by reducing the expression and activity of the negative regulators of GLUT4 traffic TBC1D1 and TBC1D4. PMID:22253718

  13. Myosin IIA participates in docking of Glut4 storage vesicles with the plasma membrane in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Chung, Le Thi Kim; Hosaka, Toshio; Harada, Nagakatsu; Jambaldorj, Bayasgalan; Fukunaga, Keiko; Nishiwaki, Yuka; Teshigawara, Kiyoshi; Sakai, Tohru; Nakaya, Yutaka; Funaki, Makoto

    2010-01-01

    In adipocytes and myocytes, insulin stimulation translocates glucose transporter 4 (Glut4) storage vesicles (GSVs) from their intracellular storage sites to the plasma membrane (PM) where they dock with the PM. Then, Glut4 is inserted into the PM and initiates glucose uptake into these cells. Previous studies using chemical inhibitors demonstrated that myosin II participates in fusion of GSVs and the PM and increase in the intrinsic activity of Glut4. In this study, the effect of myosin IIA on GSV trafficking was examined by knocking down myosin IIA expression. Myosin IIA knockdown decreased both glucose uptake and exposures of myc-tagged Glut4 to the cell surface in insulin-stimulated cells, but did not affect insulin signal transduction. Interestingly, myosin IIA knockdown failed to decrease insulin-dependent trafficking of Glut4 to the PM. Moreover, in myosin IIA knockdown cells, insulin-stimulated binding of GSV SNARE protein, vesicle-associated membrane protein 2 (VAMP2) to PM SNARE protein, syntaxin 4 was inhibited. These data suggest that myosin IIA plays a role in insulin-stimulated docking of GSVs to the PM in 3T3-L1 adipocytes through SNARE complex formation.

  14. Co-expression of CD147 and GLUT-1 indicates radiation resistance and poor prognosis in cervical squamous cell carcinoma.

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    Huang, Xin-Qiong; Chen, Xiang; Xie, Xiao-Xue; Zhou, Qin; Li, Kai; Li, Shan; Shen, Liang-Fang; Su, Juan

    2014-01-01

    The aim of this study was to investigate the association of CD147 and GLUT-1, which play important roles in glycolysis in response to radiotherapy and clinical outcomes in patients with locally advanced cervical squamous cell carcinoma (LACSCC). The records of 132 female patients who received primary radiation therapy to treat LACSCC at FIGO stages IB-IVA were retrospectively reviewed. Forty-seven patients with PFS (progression-free survival) of less than 36 months were regarded as radiation-resistant. Eighty-five patients with PFS longer than 36 months were regarded as radiation-sensitive. Using pretreatment paraffin-embedded tissues, we evaluated CD147 and GLUT-1 expression by immunohistochemistry. Overexpression of CD147, GLUT-1, and CD147 and GLUT-1 combined were 44.7%, 52.9% and 36.5%, respectively, in the radiation-sensitive group, and 91.5%, 89.4% and 83.0%, respectively, in the radiation-resistant group. The 5-year progress free survival (PFS) rates in the CD147-low, CD147-high, GLUT-1-low, GLUT-1-high, CD147- and/or GLUT-1-low and CD147- and GLUT-1- dual high expression groups were 66.79%, 87.10%, 52.78%, 85.82%, 55.94%, 82.90% and 50.82%, respectively. CD147 and GLUT-1 co-expression, FIGO stage and tumor diameter were independent poor prognostic factors for patients with LACSCC in multivariate Cox regression analysis. Patients with high expression of CD147 alone, GLUT-1 alone or co-expression of CD147 and GLUT-1 showed greater resistance to radiotherapy and a shorter PFS than those with low expression. In particular, co-expression of CD147 and GLUT-1 can be considered as a negative independent prognostic factor.

  15. FDG uptake and glut-1 expression in primary tumors and loco-regional lymph nodes in non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Lee, Won Woo; Nguyen, Xuan Canh; Chung, Jin Haeng; Park, So Yeon; Kim, Sang Eun

    2007-01-01

    FDG uptake level by primary tumors in NSCLC may affect the likelihood of malignant involvement in loco-regional lymph nodes (LNs). FDG uptake in tumors has been reported to be mediated by glucose transporter type 1 (Glut-I). Here, we investigated the correlations between primary tumors and loco-regional LNs in NSCLC regarding FDG uptake and Glut-1 expression. 126 NSCLC patients (M: F=103: 23, age=659.7y) who underwent curative resection and loco-regional LN dissection within 4 week period after FDG-PET study were enrolled. Maximum standardized uptake value (maxSUV) by PET and %Glut-1 expression by immunostaining were compared between primary tumors and FDG uptake positive loco-regional LNs. Significant correlations were found between 52 malignant LNs and 37 primary tumors in terms of maxSUV (r=0.6451, p<0.0001) and %Glut-1 expression (r=0.8341, p<0.0001). Linear regression of the relation between maxSUVs of malignant LNs (Y) and maxSUVs of primary tumors (X) yielded the expression Y = 0.5938 + 0.4808 X with an r2 value of 0.4162. On the other hand, no significant correlation was observed between 144 benign LNs and 75 primary tumors in terms of maxSUVs (r= -0.0125, p 0.8831). Moreover, %Glut-1 expressions of pathologically proven benign LNs and primary tumors were found to be correlated (r=0.3863, p=0.0004), but r2 value was low at 0.1492. High correlations were found between primary tumors and loco-regional metastatic LNs in NSCLC regarding FDG uptake and Glut-1 expression. Mediastinal LN staging of NSCLC by FDG-PET may be improved by considering the linear correlation between FDG uptakes of metastatic LNs and primary tumors

  16. GLUT3 gene expression is critical for embryonic growth, brain development and survival.

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    Carayannopoulos, Mary O; Xiong, Fuxia; Jensen, Penny; Rios-Galdamez, Yesenia; Huang, Haigen; Lin, Shuo; Devaskar, Sherin U

    2014-04-01

    Glucose is the primary energy source for eukaryotic cells and the predominant substrate for the brain. GLUT3 is essential for trans-placental glucose transport and highly expressed in the mammalian brain. To further elucidate the role of GLUT3 in embryonic development, we utilized the vertebrate whole animal model system of Danio rerio as a tractable system for defining the cellular and molecular mechanisms altered by impaired glucose transport and metabolism related to perturbed expression of GLUT3. The comparable orthologue of human GLUT3 was identified and the expression of this gene abrogated during early embryonic development. In a dose-dependent manner embryonic brain development was disrupted resulting in a phenotype of aberrant brain organogenesis, associated with embryonic growth restriction and increased cellular apoptosis. Rescue of the morphant phenotype was achieved by providing exogenous GLUT3 mRNA. We conclude that GLUT3 is critically important for brain organogenesis and embryonic growth. Disruption of GLUT3 is responsible for the phenotypic spectrum of embryonic growth restriction to demise and neural apoptosis with microcephaly. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation

    Science.gov (United States)

    Reno, Candace M.; Puente, Erwin C.; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J.; Routh, Vanessa H.; Kahn, Barbara B.

    2017-01-01

    GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. PMID:27797912

  18. 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. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  19. Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation.

    Science.gov (United States)

    Reno, Candace M; Puente, Erwin C; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J; Routh, Vanessa H; Kahn, Barbara B; Fisher, Simon J

    2017-03-01

    GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. © 2017 by the American Diabetes Association.

  20. Prognostic significance of glucose transporter-1 (GLUT1) gene expression in rectal cancer after preoperative chemoradiotherapy

    International Nuclear Information System (INIS)

    Saigusa, Susumu; Toiyama, Yuji; Tanaka, Koji; Okugawa, Yoshinaga; Fujikawa, Hiroyuki; Matsushita, Kohei; Uchida, Keiichi; Inoue, Yasuhiro; Kusunoki, Masato

    2012-01-01

    Most cancer cells exhibit increased glycolysis. The elevated glucose transporter 1 (GLUT1) expression has been reported to be associated with resistance to therapeutic agents and a poor prognosis. We wondered whether GLUT1 expression was associated with the clinical outcome in rectal cancer after preoperative chemoradiotherapy (CRT), and whether glycolysis inhibition could represent a novel anticancer treatment. We obtained total RNA from residual cancer cells using microdissection from a total of 52 rectal cancer specimens from patients who underwent preoperative CRT. We performed transcriptional analyzes, and studied the association of the GLUT1 gene expression levels with the clinical outcomes. In addition, we examined each proliferative response of three selected colorectal cancer cell lines to a glycolysis inhibitor, 3-bromopyruvic acid (3-BrPA), with regard to their expression of the GLUT1 gene. An elevated GLUT1 gene expression was associated with a high postoperative stage, the presence of lymph node metastasis, and distant recurrence. Moreover, elevated GLUT1 gene expression independently predicted both the recurrence-free and overall survival. In the in vitro studies, we observed that 3-BrPA significantly suppressed the proliferation of colon cancer cells with high GLUT1 gene expression, compared with those with low expression. An elevated GLUT1 expression may be a useful predictor of distant recurrence and poor prognosis in rectal cancer patients after preoperative CRT. (author)

  1. Induction of GLUT-1 protein in adult human skeletal muscle fibers

    DEFF Research Database (Denmark)

    Gaster, M; Franch, J; Staehr, P

    2000-01-01

    Prompted by our recent observations that GLUT-1 is expressed in fetal muscles, but not in adult muscle fibers, we decided to investigate whether GLUT-1 expression could be reactivated. We studied different stimuli concerning their ability to induce GLUT-1 expression in mature human skeletal muscle...... fibers. Metabolic stress (obesity, non-insulin-dependent diabetes mellitus), contractile activity (training), and conditions of de- and reinnervation (amyotrophic lateral sclerosis) could not induce GLUT-1 expression in human muscle fibers. However, regenerating muscle fibers in polymyositis expressed...... GLUT-1. In contrast to GLUT-1, GLUT-4 was expressed in all investigated muscle fibers. Although the significance of GLUT-1 in adult human muscle fibers appears limited, GLUT-1 may be of importance for the glucose supplies in immature and regenerating muscle....

  2. Multiple signalling pathways redundantly control glucose transporter GLUT4 gene transcription in skeletal muscle

    DEFF Research Database (Denmark)

    Murgia, Marta; Elbenhardt Jensen, Thomas; Cusinato, Marzia

    2009-01-01

    on pharmacological evidence. Here, we have used a more specific genetic approach to establish the relative role of the three pathways in fast and slow muscles. Plasmids coding for protein inhibitors of CaMKII or calcineurin were co-transfected in vivo with a GLUT4 enhancer-reporter construct either in normal mice...... or in mice expressing a dominant negative AMPK mutant. GLUT4 reporter activity was not inhibited in the slow soleus muscle by blocking either CaMKII or calcineurin alone, but was inhibited by blocking both pathways. GLUT4 reporter activity was likewise unchanged in the soleus of dnAMPK mice......, but was significantly reduce by incapacitation of either CaMKII or calcineurin in these mice. On the other hand, in the fast tibialis anterior muscle, calcineurin appears to exert a prominent role in the control of GLUT4 reporter activity, independent of CaMKII and AMPK. The results point to a muscle type...

  3. Insulin regulates Glut4 confinement in plasma membrane clusters in adipose cells.

    Science.gov (United States)

    Lizunov, Vladimir A; Stenkula, Karin; Troy, Aaron; Cushman, Samuel W; Zimmerberg, Joshua

    2013-01-01

    Insulin-stimulated delivery of glucose transporter-4 (GLUT4) to the plasma membrane (PM) is the hallmark of glucose metabolism. In this study we examined insulin's effects on GLUT4 organization in PM of adipose cells by direct microscopic observation of single monomers tagged with photoswitchable fluorescent protein. In the basal state, after exocytotic delivery only a fraction of GLUT4 is dispersed into the PM as monomers, while most of the GLUT4 stays at the site of fusion and forms elongated clusters (60-240 nm). GLUT4 monomers outside clusters diffuse freely and do not aggregate with other monomers. In contrast, GLUT4 molecule collision with an existing cluster can lead to immediate confinement and association with that cluster. Insulin has three effects: it shifts the fraction of dispersed GLUT4 upon delivery, it augments the dissociation of GLUT4 monomers from clusters ∼3-fold and it decreases the rate of endocytic uptake. All together these three effects of insulin shift most of the PM GLUT4 from clustered to dispersed states. GLUT4 confinement in clusters represents a novel kinetic mechanism for insulin regulation of glucose homeostasis.

  4. Insulin regulates Glut4 confinement in plasma membrane clusters in adipose cells.

    Directory of Open Access Journals (Sweden)

    Vladimir A Lizunov

    Full Text Available Insulin-stimulated delivery of glucose transporter-4 (GLUT4 to the plasma membrane (PM is the hallmark of glucose metabolism. In this study we examined insulin's effects on GLUT4 organization in PM of adipose cells by direct microscopic observation of single monomers tagged with photoswitchable fluorescent protein. In the basal state, after exocytotic delivery only a fraction of GLUT4 is dispersed into the PM as monomers, while most of the GLUT4 stays at the site of fusion and forms elongated clusters (60-240 nm. GLUT4 monomers outside clusters diffuse freely and do not aggregate with other monomers. In contrast, GLUT4 molecule collision with an existing cluster can lead to immediate confinement and association with that cluster. Insulin has three effects: it shifts the fraction of dispersed GLUT4 upon delivery, it augments the dissociation of GLUT4 monomers from clusters ∼3-fold and it decreases the rate of endocytic uptake. All together these three effects of insulin shift most of the PM GLUT4 from clustered to dispersed states. GLUT4 confinement in clusters represents a novel kinetic mechanism for insulin regulation of glucose homeostasis.

  5. VEGF and GLUT1 are highly heritable, inversely correlated and affected by dietary fat intake: Consequences for cognitive function in humans

    Directory of Open Access Journals (Sweden)

    Rita Schüler

    2018-05-01

    Full Text Available Objective: Reduction of brain glucose transporter GLUT1 results in severe neurological dysfunction. VEGF is required to restore and maintain brain glucose uptake across the blood brain barrier via GLUT1, which was shown to be acutely diminished in response to a high fat diet (HFD in mice. The genetic and HFD-related regulation and association of VEGF and GLUT1 (SLC2A1 in humans was investigated in the NUtriGenomic Analysis in Twins (NUGAT study. Methods: 92 healthy and non-obese twins were standardized to a high-carbohydrate low-fat diet for 6 weeks before switched to a 6-week HFD under isocaloric conditions. Three clinical investigation days were conducted: after 6 weeks of low-fat diet and after 1 and 6 weeks of HFD. Serum VEGF and other cytokine levels were measured using ELISA. Gene expression in subcutaneous adipose tissue was assessed by quantitative Real-Time PCR. Genotyping was performed using microarray. The Auditory Verbal Learning Task was conducted to measure cognitive performance. Results: In this human study, we showed that the environmental regulation of SLC2A1 expression and serum VEGF by HFD was inversely correlated and both factors showed strong heritability (>90%. In response to the HFD containing 45% fat, serum VEGF levels increased (P = 0.002 while SLC2A1 mRNA expression in adipose tissue decreased (P = 0.001. Higher BMI was additionally associated with lower SLC2A1 expression. AA-genotypes of the rs9472159 polymorphism, which explained ∼39% of the variation in circulating VEGF concentrations, showed significantly reduced serum VEGF levels (P = 6.4 × 10−11 but higher SLC2A1 expression (P = 0.009 in adipose tissue compared to CC/CA-genotypes after 6 weeks of HFD. Memory performance in AA-genotypes declined in response to the HFD compared to CC- and CA-genotypes. Conclusions: The results provide evidence to suggest the translatability of the dietary regulation of VEGF and GLUT1 from mouse models to humans. Our

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    Bolado-Carrancio, A.; Riancho, J.A.; Sainz, J.; Rodríguez-Rey, J.C.

    2014-01-01

    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

  8. Dehydroepiandrosterone activates AMP kinase and regulates GLUT4 and PGC-1α expression in C2C12 myotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yokokawa, Takumi [Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto (Japan); Sato, Koji [Graduate School of Sport & Health Science, Ritsumeikan University, Shiga (Japan); Iwanaka, Nobumasa [The Graduate School of Science and Engineering, Ritsumeikan University, Shiga (Japan); Honda, Hiroki [Graduate School of Sport & Health Science, Ritsumeikan University, Shiga (Japan); Higashida, Kazuhiko [Faculty of Sport Science, Waseda University, Saitama (Japan); Iemitsu, Motoyuki [Graduate School of Sport & Health Science, Ritsumeikan University, Shiga (Japan); Hayashi, Tatsuya [Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto (Japan); Hashimoto, Takeshi, E-mail: thashimo@fc.ritsumei.ac.jp [Graduate School of Sport & Health Science, Ritsumeikan University, Shiga (Japan)

    2015-07-17

    Exercise and caloric restriction (CR) have been reported to have anti-ageing, anti-obesity, and health-promoting effects. Both interventions increase the level of dehydroepiandrosterone (DHEA) in muscle and blood, suggesting that DHEA might partially mediate these effects. In addition, it is thought that either 5′-adenosine monophosphate-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mediates the beneficial effects of exercise and CR. However, the effects of DHEA on AMPK activity and PGC-1α expression remain unclear. Therefore, we explored whether DHEA in myotubes acts as an activator of AMPK and increases PGC-1α. DHEA exposure increased glucose uptake but not the phosphorylation levels of Akt and PKCζ/λ in C2C12 myotubes. In contrast, the phosphorylation levels of AMPK were elevated by DHEA exposure. Finally, we found that DHEA induced the expression of the genes PGC-1α and GLUT4. Our current results might reveal a previously unrecognized physiological role of DHEA; the activation of AMPK and the induction of PGC-1α by DHEA might mediate its anti-obesity and health-promoting effects in living organisms. - Highlights: • We assessed whether dehydroepiandrosterone (DHEA) activates AMPK and PGC-1α. • DHEA exposure increased glucose uptake in C2C12 myotubes. • The phosphorylation levels of AMPK were elevated by DHEA exposure. • DHEA induced the expression of the genes PGC-1α and GLUT4. • AMPK might mediate the anti-obesity and health-promoting effects of DHEA.

  9. Dehydroepiandrosterone activates AMP kinase and regulates GLUT4 and PGC-1α expression in C2C12 myotubes

    International Nuclear Information System (INIS)

    Yokokawa, Takumi; Sato, Koji; Iwanaka, Nobumasa; Honda, Hiroki; Higashida, Kazuhiko; Iemitsu, Motoyuki; Hayashi, Tatsuya; Hashimoto, Takeshi

    2015-01-01

    Exercise and caloric restriction (CR) have been reported to have anti-ageing, anti-obesity, and health-promoting effects. Both interventions increase the level of dehydroepiandrosterone (DHEA) in muscle and blood, suggesting that DHEA might partially mediate these effects. In addition, it is thought that either 5′-adenosine monophosphate-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mediates the beneficial effects of exercise and CR. However, the effects of DHEA on AMPK activity and PGC-1α expression remain unclear. Therefore, we explored whether DHEA in myotubes acts as an activator of AMPK and increases PGC-1α. DHEA exposure increased glucose uptake but not the phosphorylation levels of Akt and PKCζ/λ in C2C12 myotubes. In contrast, the phosphorylation levels of AMPK were elevated by DHEA exposure. Finally, we found that DHEA induced the expression of the genes PGC-1α and GLUT4. Our current results might reveal a previously unrecognized physiological role of DHEA; the activation of AMPK and the induction of PGC-1α by DHEA might mediate its anti-obesity and health-promoting effects in living organisms. - Highlights: • We assessed whether dehydroepiandrosterone (DHEA) activates AMPK and PGC-1α. • DHEA exposure increased glucose uptake in C2C12 myotubes. • The phosphorylation levels of AMPK were elevated by DHEA exposure. • DHEA induced the expression of the genes PGC-1α and GLUT4. • AMPK might mediate the anti-obesity and health-promoting effects of DHEA

  10. GLUT2-mediated glucose uptake and availability are required for embryonic brain development in zebrafish.

    Science.gov (United States)

    Marín-Juez, Rubén; Rovira, Mireia; Crespo, Diego; van der Vaart, Michiel; Spaink, Herman P; Planas, Josep V

    2015-01-01

    Glucose transporter 2 (GLUT2; gene name SLC2A2) has a key role in the regulation of glucose dynamics in organs central to metabolism. Although GLUT2 has been studied in the context of its participation in peripheral and central glucose sensing, its role in the brain is not well understood. To decipher the role of GLUT2 in brain development, we knocked down slc2a2 (glut2), the functional ortholog of human GLUT2, in zebrafish. Abrogation of glut2 led to defective brain organogenesis, reduced glucose uptake and increased programmed cell death in the brain. Coinciding with the observed localization of glut2 expression in the zebrafish hindbrain, glut2 deficiency affected the development of neural progenitor cells expressing the proneural genes atoh1b and ptf1a but not those expressing neurod. Specificity of the morphant phenotype was demonstrated by the restoration of brain organogenesis, whole-embryo glucose uptake, brain apoptosis, and expression of proneural markers in rescue experiments. These results indicate that glut2 has an essential role during brain development by facilitating the uptake and availability of glucose and support the involvement of glut2 in brain glucose sensing.

  11. Gene gun bombardment-mediated expression and translocation of EGFP-tagged GLUT4 in skeletal muscle fibres in vivo

    DEFF Research Database (Denmark)

    Lauritzen, Hans P M M; Reynet, Christine; Schjerling, Peter

    2002-01-01

    the enhanced green fluorescent protein (EGFP) labelling technique with physical transfection methods in vivo: intramuscular plasmid injection or gene gun bombardment. During optimisation experiments with plasmid coding for the EGFP reporter alone EGFP-positive muscle fibres were counted after collagenase...... treatment of in vivo transfected flexor digitorum brevis (FDB) muscles. In contrast to gene gun bombardment, intramuscular injection produced EGFP expression in only a few fibres. Regardless of the transfection technique, EGFP expression was higher in muscles from 2-week-old rats than in those from 6-week......Cellular protein trafficking has been studied to date only in vitro or with techniques that are invasive and have a low time resolution. To establish a gentle method for analysis of glucose transporter-4 (GLUT4) trafficking in vivo in fully differentiated rat skeletal muscle fibres we combined...

  12. Chloroquine Increases Glucose Uptake via Enhancing GLUT4 Translocation and Fusion with the Plasma Membrane in L6 Cells

    Directory of Open Access Journals (Sweden)

    Qi Zhou

    2016-05-01

    Full Text Available Background/Aims: Chloroquine can induce an increase in the cellular uptake of glucose; however, the underlying mechanism is unclear. Methods: In this study, translocation of GLUT4 and intracellular Ca2+ changes were simultaneously observed by confocal microscope in L6 cells stably over-expressing IRAP-mOrange. The GLUT4 fusion with the plasma membrane (PM was traced using HA-GLUT4-GFP. Glucose uptake was measured using a cell-based glucose uptake assay. GLUT4 protein was detected by Western blotting and mRNA level was detected by RT-PCR. Results: We found that chloroquine induced significant increases in glucose uptake, glucose transporter GLUT4 translocation to the plasma membrane (GTPM, GLUT4 fusion with the PM, and intracellular Ca2+ in L6 muscle cells. Chloroquine-induced increases of GTPM and intracellular Ca2+ were inhibited by Gallein (Gβγ inhibitor and U73122 (PLC inhibitor. However, 2-APB (IP3R blocker only blocked the increase in intracellular Ca2+ but did not inhibit GTPM increase. These results indicate that chloroquine, via the Gβγ-PLC-IP3-IP3R pathway, induces elevation of Ca2+, and this Ca2+ increase does not play a role in chloroqui-ne-evoked GTPM increase. However, GLUT4 fusion with the PM and glucose uptake were significantly inhibited with BAPTA-AM. This suggests that Ca2+ enhances GLUT4 fusion with the PM resulting in glucose uptake increase. Conclusion: Our data indicate that chloroquine via Gβγ-PLC-IP3-IP3R induces Ca2+ elevation, which in turn promotes GLUT4 fusion with the PM. Moreover, chloroquine can enhance GLUT4 trafficking to the PM. These mechanisms eventually result in glucose uptake increase in control and insulin-resistant L6 cells. These findings suggest that chloroquine might be a potential drug for improving insulin tolerance in diabetic patients.

  13. The t-SNAREs syntaxin4 and SNAP23 but not v-SNARE VAMP2 are indispensable to tether GLUT4 vesicles at the plasma membrane in adipocyte

    International Nuclear Information System (INIS)

    Kawaguchi, Takayuki; Tamori, Yoshikazu; Kanda, Hajime; Yoshikawa, Mari; Tateya, Sanshiro; Nishino, Naonobu; Kasuga, Masato

    2010-01-01

    SNARE proteins (VAMP2, syntaxin4, and SNAP23) have been thought to play a key role in GLUT4 trafficking by mediating the tethering, docking and subsequent fusion of GLUT4-containing vesicles with the plasma membrane. The precise functions of these proteins have remained elusive, however. We have now shown that depletion of the vesicle SNARE (v-SNARE) VAMP2 by RNA interference in 3T3-L1 adipocytes inhibited the fusion of GLUT4 vesicles with the plasma membrane but did not affect tethering of the vesicles to the membrane. In contrast, depletion of the target SNAREs (t-SNAREs) syntaxin4 or SNAP23 resulted in impairment of GLUT4 vesicle tethering to the plasma membrane. Our results indicate that the t-SNAREs syntaxin4 and SNAP23 are indispensable for the tethering of GLUT4 vesicles to the plasma membrane, whereas the v-SNARE VAMP2 is not required for this step but is essential for the subsequent fusion event.

  14. Analysis of GLUT-1, GLUT-3, and angiogenic index in syndromic and non-syndromic keratocystic odontogenic tumors

    Directory of Open Access Journals (Sweden)

    Rafaella Bastos LEITE

    2017-04-01

    Full Text Available Abstract The aim of this study was to evaluate the immunoexpression of glucose transporters 1 (GLUT-1 and 3 (GLUT-3 in keratocystic odontogenic tumors associated with Gorlin syndrome (SKOTs and non-syndromic keratocystic odontogenic tumors (NSKOTs, and to establish correlations with the angiogenic index. Seventeen primary NSKOTs, seven recurrent NSKOTs, and 17 SKOTs were selected for the study. The percentage of immunopositive cells for GLUT-1 and GLUT-3 in the epithelial component of the tumors was assessed. The angiogenic index was determined by microvessel count. The results were analyzed statistically using the nonparametric Kruskal-Wallis test and Spearman’s correlation test. High epithelial immunoexpression of GLUT-1 was observed in most tumors (p = 0.360. There was a higher frequency of negative cases for GLUT-3 in all groups. The few GLUT-3-positive tumors exhibited low expression of this protein in epithelial cells. No significant difference in the angiogenic index was observed between groups (p = 0.778. GLUT-1 expression did not correlate significantly with the angiogenic index (p > 0.05. The results suggest that the more aggressive biological behavior of SKOTs when compared to NSKOTs may not be related to GLUT-1 or GLUT-3 expression. GLUT-1 may play an important role in glucose uptake by epithelial cells of KOTs and this process is unlikely related to the angiogenic index. GLUT-1 could be a potential target for future development of therapeutic strategies for KOTs.

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

    OpenAIRE

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

    2014-01-01

    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 ...

  16. α-Mangostin Improves Glucose Uptake and Inhibits Adipocytes Differentiation in 3T3-L1 Cells via PPARγ, GLUT4, and Leptin Expressions

    Directory of Open Access Journals (Sweden)

    Muhammad Taher

    2015-01-01

    Full Text Available Obesity has been often associated with the occurrence of cardiovascular diseases, type 2 diabetes, and cancer. The development of obesity is also accompanied by significant differentiation of preadipocytes into adipocytes. In this study, we investigated the activity of α-mangostin, a major xanthone component isolated from the stem bark of G. malaccensis, on glucose uptake and adipocyte differentiation of 3T3-L1 cells focusing on PPARγ, GLUT4, and leptin expressions. α-Mangostin was found to inhibit cytoplasmic lipid accumulation and adipogenic differentiation. Cells treated with 50 μM of α-mangostin reduced intracellular fat accumulation dose-dependently up to 44.4% relative to MDI-treated cells. Analyses of 2-deoxy-D-[3H] glucose uptake activity showed that α-mangostin significantly improved the glucose uptake (P<0.05 with highest activity found at 25 μM. In addition, α-mangostin increased the amount of free fatty acids (FFA released. The highest glycerol release level was observed at 50 μM of α-mangostin. qRT-PCR analysis showed reduced lipid accumulation via inhibition of PPARγ gene expression. Induction of glucose uptake and free fatty acid release by α-mangostin were accompanied by increasing mRNA expression of GLUT4 and leptin. These evidences propose that α-mangostin might be possible candidate for the effective management of obesity in future.

  17. 糖脂平对胰岛素抵抗大鼠 GLUT4表达的影响%Impact of Tangzhiping on GUIT4 Expression in the Rats of Insulin Resistance

    Institute of Scientific and Technical Information of China (English)

    刘静; 朱智耀; 高彦彬; 赵轩; 周盛楠; 李娇阳; 仝宇; 王晓磊

    2016-01-01

    Objective To observe the impacts of tangzhiping on GLUT4 expression of epicyte of skeletal muscle in the rats of insulin resistance induced by high - lipid diet. Methods Forty - eight male SD rats,weighted from 180 to 200 g were selected and randomized into a blank group(12 rats)and a modeling group(36 rats). In the blank group,the common forage was used. In the model group,the high - lipid forage was used. After successful modeling in 8 weeks,the rats in the modeling group was subdivided randomly into a mode group,a Chinese medicine group and a western medicine group,12 rats in each one. In the Chinese medicine group,tangzhiping was used for gavage,20 g/ kg a day. In the western medicine group,rosiglitazone was used for gavage,0. 8 mg/ kg a day. The physical saline of same dose was used for gavage in the model group and the blank group. The gavage lasted for 8 weeks continuously. After the last medication,fasting was done for 12 h. The euglycemic hyperinsulinemic clamp technique was performed to evaluate the insulin sensi-tivity(M value). Enzymatic detection was used to measure the levels of TC,TG,HDL - C and LDL - C. Western Blot was used to detect GLUT4 expression of epicyte of skeletal muscle. Results Compared with the blank group,the insulin sensitivity was apparently reduced,the levels of TC,TG and LDL - C were apparently increased,HDL - C and GLUT4 expression were apparently reduced in the model group. Compared with the model group,the insulin sensitivity was increased apparently,the levels of TG and LDL - C were reduced, GLUT4 expression was increased apparently in the Chinese medicine group. The changes in TC and HDL - C were not apparent. Conclusion Tangzhiping improves the insulin sensitivity and adjusts lipid metabolic dis-turbance in the rats of insulin resistance. The effect mechanism may be related to the improvement of GLUT4 expression in epicyte of skeletal muscle and enhancement of the absorption and utility of skeletal muscular tissue to glucose

  18. Overexpression of protein tyrosine phosphatase-alpha (PTP-alpha) but not PTP-kappa inhibits translocation of GLUT4 in rat adipose cells

    DEFF Research Database (Denmark)

    Cong, L N; Chen, H; Li, Y

    1999-01-01

    Protein tyrosine phosphatases (PTPases) are likely to play important roles in insulin action. We recently demonstrated that the nontransmembrane PTPase PTP1B can act as a negative modulator of insulin-stimulated translocation of GLUT4. We now examine the role of PTP-alpha and PTP-kappa (two...... of cell surface GLUT4 in response to insulin and a threefold decrease in insulin sensitivity when compared with control cells expressing only tagged GLUT4. Co-overexpression of PTP-alpha and PTP1B did not have additive effects, suggesting that these PTPases share common substrates. Cells overexpressing...

  19. Similar [DE]XXXL[LI] motifs differentially target GLUT8 and GLUT12 in Chinese Hamster Ovary Cells

    OpenAIRE

    Flessner, Lauren B.; Moley, Kelle H.

    2008-01-01

    The transport of glucose across cell membranes is mediated by facilitative glucose transporters. The recently identified Class III glucose transporter GLUT12 is predominantly expressed in insulin-sensitive tissues such as heart, fat, and skeletal muscle. We examined the subcellular localization of GLUT12 in CHO and HEK293 cells stably expressing murine GLUT12. We have previously shown that another Class III glucose transporter, GLUT8, contains a [DE]XXXL[LI] motif that directs it to late endo...

  20. Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs

    Directory of Open Access Journals (Sweden)

    A.M. Vargas

    2004-07-01

    Full Text Available The GLUT4 transporter plays a key role in insulin-induced glucose uptake, which is impaired in insulin resistance. The objective of the present study was to investigate the tissue content and the subcellular distribution of GLUT4 protein in 4- to 12-year-old control, obese and insulin-treated diabetic mongrel female dogs (4 animals per group. The parametrial white adipose tissue was sampled and processed to obtain both plasma membrane and microsome subcellular fractions for GLUT4 analysis by Western blotting. There was no significant difference in glycemia and insulinemia between control and obese animals. Diabetic dogs showed hyperglycemia (369.9 ± 89.9 mg/dl. Compared to control, the plasma membrane GLUT4, reported per g tissue, was reduced by 55% (P < 0.01 in obese dogs, and increased by 30% (P < 0.05 in diabetic dogs, and the microsomal GLUT4 was increased by ~45% (P < 0.001 in both obese and diabetic animals. Considering the sum of GLUT4 measured in plasma membrane and microsome as total cellular GLUT4, percent GLUT4 present in plasma membrane was reduced by ~65% (P < 0.001 in obese compared to control and diabetic animals. Since insulin stimulates GLUT4 translocation to the plasma membrane, percent GLUT4 in plasma membrane was divided by the insulinemia at the time of tissue removal and was found to be reduced by 75% (P < 0.01 in obese compared to control dogs. We conclude that the insulin-stimulated translocation of GLUT4 to the cell surface is reduced in obese female dogs. This probably contributes to insulin resistance, which plays an important role in glucose homeostasis in dogs.

  1. Shikonin regulates C-MYC and GLUT1 expression through the MST1-YAP1-TEAD1 axis

    Energy Technology Data Exchange (ETDEWEB)

    Vališ, Karel, E-mail: karel.valis@biomed.cas.cz [Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology, v.v.i., The Czech Academy of Sciences, Prague (Czech Republic); Faculty of Science, Charles University, Prague (Czech Republic); Talacko, Pavel; Grobárová, Valéria [Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology, v.v.i., The Czech Academy of Sciences, Prague (Czech Republic); Faculty of Science, Charles University, Prague (Czech Republic); Černý, Jan [Faculty of Science, Charles University, Prague (Czech Republic); Novák, Petr, E-mail: pnovak@biomed.cas.cz [Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology, v.v.i., The Czech Academy of Sciences, Prague (Czech Republic); Faculty of Science, Charles University, Prague (Czech Republic)

    2016-12-10

    The general mechanism underlying the tumor suppressor activity of the Hippo signaling pathway remains unclear. In this study, we explore the molecular mechanisms connecting the Hippo signaling pathway with glucose metabolism. We have found that two key regulators of glycolysis, C-MYC and GLUT1, are targets of the Hippo signaling pathway in human leukemia cells. Our results revealed that activation of MST1 by the natural compound shikonin inhibited the expression of GLUT1 and C-MYC. Furthermore, RNAi experiments confirmed the regulation of GLUT1 and C-MYC expression via the MST1-YAP1-TEAD1 axis. Surprisingly, YAP1 was found to positively regulate C-MYC mRNA levels in complex with TEAD1, while it negatively regulates C-MYC levels in cooperation with MST1. Hence, YAP1 serves as a rheostat for C-MYC, which is regulated by MST1. In addition, depletion of MST1 stimulates lactate production, whereas the specific depletion of TEAD1 has an opposite effect. The inhibition of lactate production and cellular proliferation induced by shikonin also depends on the Hippo pathway activity. Finally, a bioinformatic analysis revealed conserved TEAD-binding motifs in the C-MYC and GLUT1 promoters providing another molecular data supporting our observations. In summary, regulation of glucose metabolism could serve as a new tumor suppressor mechanism orchestrated by the Hippo signaling pathway. - Highlights: • Shikonin inhibits C-MYC and GLUT1 expression in MST1 and YAP1 dependent manner. • YAP1-TEAD1 interaction activates C-MYC and GLUT1 expression. • MST1 in cooperation with YAP1 inhibits C-MYC and GLUT1 expression. • MST1-YAP1-TEAD1 axis regulates lactate production by leukemic cells. • MST1 and YAP1 proteins block proliferation of leukemic cells.

  2. GLUT4 Mobilization Supports Energetic Demands of Active Synapses.

    Science.gov (United States)

    Ashrafi, Ghazaleh; Wu, Zhuhao; Farrell, Ryan J; Ryan, Timothy A

    2017-02-08

    The brain is highly sensitive to proper fuel availability as evidenced by the rapid decline in neuronal function during ischemic attacks and acute severe hypoglycemia. We previously showed that sustained presynaptic function requires activity-driven glycolysis. Here, we provide strong evidence that during action potential (AP) firing, nerve terminals rely on the glucose transporter GLUT4 as a glycolytic regulatory system to meet the activity-driven increase in energy demands. Activity at synapses triggers insertion of GLUT4 into the axonal plasma membrane driven by activation of the metabolic sensor AMP kinase. Furthermore, we show that genetic ablation of GLUT4 leads to an arrest of synaptic vesicle recycling during sustained AP firing, similar to what is observed during acute glucose deprivation. The reliance on this biochemical regulatory system for "exercising" synapses is reminiscent of that occurring in exercising muscle to sustain cellular function and identifies nerve terminals as critical sites of proper metabolic control. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Crystal structure of a bacterial homologue of glucose transporters GLUT1-4.

    Science.gov (United States)

    Sun, Linfeng; Zeng, Xin; Yan, Chuangye; Sun, Xiuyun; Gong, Xinqi; Rao, Yu; Yan, Nieng

    2012-10-18

    Glucose transporters are essential for metabolism of glucose in cells of diverse organisms from microbes to humans, exemplified by the disease-related human proteins GLUT1, 2, 3 and 4. Despite rigorous efforts, the structural information for GLUT1-4 or their homologues remains largely unknown. Here we report three related crystal structures of XylE, an Escherichia coli homologue of GLUT1-4, in complex with d-xylose, d-glucose and 6-bromo-6-deoxy-D-glucose, at resolutions of 2.8, 2.9 and 2.6 Å, respectively. The structure consists of a typical major facilitator superfamily fold of 12 transmembrane segments and a unique intracellular four-helix domain. XylE was captured in an outward-facing, partly occluded conformation. Most of the important amino acids responsible for recognition of D-xylose or d-glucose are invariant in GLUT1-4, suggesting functional and mechanistic conservations. Structure-based modelling of GLUT1-4 allows mapping and interpretation of disease-related mutations. The structural and biochemical information reported here constitutes an important framework for mechanistic understanding of glucose transporters and sugar porters in general.

  4. Wushenziye Formula Improves Skeletal Muscle Insulin Resistance in Type 2 Diabetes Mellitus via PTP1B-IRS1-Akt-GLUT4 Signaling Pathway.

    Science.gov (United States)

    Tian, Chunyu; Chang, Hong; La, Xiaojin; Li, Ji-An

    2017-01-01

    Background. Wushenziye formula (WSZYF) is an effective traditional Chinese medicine in the treatment of type 2 diabetes mellitus (T2DM). Aim. This study aimed to identify the effects and underlying mechanisms of WSZYF on improving skeletal muscle insulin resistance in T2DM. Methods. An animal model of T2DM was induced by Goto-Kakizaki diabetes prone rats fed with high fat and sugar for 4 weeks. Insulin resistance model was induced in skeletal muscle cell. Results. In vivo , WSZYF improved general conditions and decreased significantly fasting blood glucose, glycosylated serum protein, glycosylated hemoglobin, insulin concentration, and insulin resistance index of T2DM rats. In vitro , WSZYF enhanced glucose consumption in insulin resistance model of skeletal muscle cell. Furthermore, WSZYF affected the expressions of molecules in regulating T2DM, including increasing the expressions of p-IRS1, p-Akt, and GLUT4, reducing PTP1B expression. Conclusion . These findings displayed the potential of WSZYF as a new drug candidate in the treatment of T2DM and the antidiabetic mechanism of WSZYF is probably mediated through modulating the PTP1B-IRS1-Akt-GLUT4 signaling pathway.

  5. Wushenziye Formula Improves Skeletal Muscle Insulin Resistance in Type 2 Diabetes Mellitus via PTP1B-IRS1-Akt-GLUT4 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Chunyu Tian

    2017-01-01

    Full Text Available Background. Wushenziye formula (WSZYF is an effective traditional Chinese medicine in the treatment of type 2 diabetes mellitus (T2DM. Aim. This study aimed to identify the effects and underlying mechanisms of WSZYF on improving skeletal muscle insulin resistance in T2DM. Methods. An animal model of T2DM was induced by Goto-Kakizaki diabetes prone rats fed with high fat and sugar for 4 weeks. Insulin resistance model was induced in skeletal muscle cell. Results. In vivo, WSZYF improved general conditions and decreased significantly fasting blood glucose, glycosylated serum protein, glycosylated hemoglobin, insulin concentration, and insulin resistance index of T2DM rats. In vitro, WSZYF enhanced glucose consumption in insulin resistance model of skeletal muscle cell. Furthermore, WSZYF affected the expressions of molecules in regulating T2DM, including increasing the expressions of p-IRS1, p-Akt, and GLUT4, reducing PTP1B expression. Conclusion. These findings displayed the potential of WSZYF as a new drug candidate in the treatment of T2DM and the antidiabetic mechanism of WSZYF is probably mediated through modulating the PTP1B-IRS1-Akt-GLUT4 signaling pathway.

  6. GLUT4 is reduced in slow muscle fibers of type 2 diabetic patients: is insulin resistance in type 2 diabetes a slow, type 1 fiber disease?

    DEFF Research Database (Denmark)

    Gaster, M; Staehr, P; Beck-Nielsen, H

    2001-01-01

    To gain further insight into the mechanisms underlying muscle insulin resistance, the influence of obesity and type 2 diabetes on GLUT4 immunoreactivity in slow and fast skeletal muscle fibers was studied. Through a newly developed, very sensitive method using immunohistochemistry combined...... with morphometry, GLUT4 density was found to be significantly higher in slow compared with fast fibers in biopsy specimens from lean and obese subjects. In contrast, in type 2 diabetic subjects, GLUT4 density was significantly lower in slow compared with fast fibers. GLUT4 density in slow fibers from diabetic...... was reduced to 77% in the obese subjects and to 61% in type 2 diabetic patients compared with the control subjects. We propose that a reduction in the fraction of slow-twitch fibers, combined with a reduction in GLUT4 expression in slow fibers, may reduce the insulin-sensitive GLUT4 pool in type 2 diabetes...

  7. HIF-1α and GLUT-1 Expression in Atypical Endometrial Hyperplasia, Type I and II Endometrial Carcinoma: A Potential Role in Pathogenesis

    Science.gov (United States)

    Abdou, Asmaa Gaber; Wahed, Moshira Mohammed Abdel; Kassem, Hend Abdou

    2016-01-01

    Introduction Hypoxia-Inducible Factor 1α (HIF-1α) is one of the major adaptive responses to hypoxia, regulating the activity of glucose transporter -1 (GLUT-1), responsible for glucose uptake. Aim To evaluate the immunohistochemical expression of both HIF-1α and GLUT-1 in type I and II endometrial carcinoma and their correlation with the available clinicopathologic variables in each type. Materials and Methods A retrospective study was conducted on archival blocks diagnosed from pathology department between April 2010 and August 2014 included 9 cases of atypical hyperplasia and 67 cases of endometrial carcinoma. Evaluation of both HIF-1α and GLUT-1 expression using standard immunohistochemical techniques performed on cut sections from selected paraffin embedded blocks. Statistical Analysis Descriptive analysis of the variables and statistical significances were calculated by non-parametric chi-square test using the Statistical Package for the Social Sciences version 12.0 (SPSS). Results HIF-1α was expressed in epithelial (88.9%, 52.2%, 61.2% and 50%) and stromal (33.3%, 74.6%. 71.4% and 83.3%) components of hyperplasia, total cases of EC, type I and II EC, respectively. GLUT-1 was expressed in the epithelial component of 88.9%, 98.5%, 98% and 100% of hyperplasia, total EC cases, type I and II EC, respectively. The necrosis related pattern of epithelial HIF-1α expression was in favour of type II (p=0.018) and grade III (p=0.038). HIF-1α H-score was associated with high apoptosis in both type I and total cases of EC (p=0.04). GLUT-1 H-score was negatively correlated with apoptotic count (p=0.04) and associated with high grade (p=0.003) and advanced stage in total EC (p=0.004). GLUT-1 H-score was correlated with the pattern of HIF-1α staining in all cases of EC (p= 0.04). Conclusion The role of HIF-1α in epithelial cells may differ from that of stromal cells in EC; however they augment the expression of each other supporting the crosstalk between them. The

  8. Fructose-induced increases in expression of intestinal fructolytic and gluconeogenic genes are regulated by GLUT5 and KHK

    Science.gov (United States)

    Patel, Chirag; Douard, Veronique; Yu, Shiyan; Tharabenjasin, Phuntila; Gao, Nan

    2015-01-01

    Marked increases in fructose consumption have been tightly linked to metabolic diseases. One-third of ingested fructose is metabolized in the small intestine, but the underlying mechanisms regulating expression of fructose-metabolizing enzymes are not known. We used genetic mouse models to test the hypothesis that fructose absorption via glucose transporter protein, member 5 (GLUT5), metabolism via ketohexokinase (KHK), as well as GLUT5 trafficking to the apical membrane via the Ras-related protein in brain 11a (Rab11a)-dependent endosomes are required for the regulation of intestinal fructolytic and gluconeogenic enzymes. Fructose feeding increased the intestinal mRNA and protein expression of these enzymes in the small intestine of adult wild-type (WT) mice compared with those gavage fed with lysine or glucose. Fructose did not increase expression of these enzymes in the GLUT5 knockout (KO) mice. Blocking intracellular fructose metabolism by KHK ablation also prevented fructose-induced upregulation. Glycolytic hexokinase I expression was similar between WT and GLUT5- or KHK-KO mice and did not vary with feeding solution. Gavage feeding with the fructose-specific metabolite glyceraldehyde did not increase enzyme expression, suggesting that signaling occurs before the hydrolysis of fructose to three-carbon compounds. Impeding GLUT5 trafficking to the apical membrane using intestinal epithelial cell-specific Rab11a-KO mice impaired fructose-induced upregulation. KHK expression was uniformly distributed along the villus but was localized mainly in the basal region of the cytosol of enterocytes. The feedforward upregulation of fructolytic and gluconeogenic enzymes specifically requires GLUT5 and KHK and may proactively enhance the intestine's ability to process anticipated increases in dietary fructose concentrations. PMID:26084694

  9. Rac1 signalling towards GLUT4/glucose uptake in skeletal muscle

    DEFF Research Database (Denmark)

    Chiu, Tim T; Jensen, Thomas Elbenhardt; Sylow, Lykke

    2011-01-01

    Small Rho family GTPases are important regulators of cellular traffic. Emerging evidence now implicates Rac1 and Rac-dependent actin reorganisation in insulin-induced recruitment of glucose transporter-4 (GLUT4) to the cell surface of muscle cells and mature skeletal muscle. This review summarises...... the current thinking on the regulation of Rac1 by insulin, the role of Rac-dependent cortical actin remodelling in GLUT4 traffic, and the impact of Rac1 towards insulin resistance in skeletal muscle....

  10. Gene Expression of Glucose Transporter 1 (GLUT1), Hexokinase 1 and Hexokinase 2 in Gastroenteropancreatic Neuroendocrine Tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Federspiel, Birgitte Hartnack

    2013-01-01

    -associated genes and to compare this with FDG-PET imaging as well as with the cellular proliferation index in two cancer entities with different malignant potential. Using real-time PCR, gene expression of GLUT1, HK1 and HK2 were studied in 34 neuroendocrine tumors (NETs) in comparison with 14 colorectal...... adenocarcinomas (CRAs). The Ki67 proliferation index and, when available, FDG-PET imaging was compared with gene expression. Overexpression of GLUT1 gene expression was less frequent in NETs (38%) compared to CRAs (86%), P = 0.004. HK1 was overexpressed in 41% and 71% of NETs and CRAs, respectively (P = 0.......111) and HK2 was overexpressed in 50% and 64% of NETs and CRAs, respectively (P = 0.53). There was a significant correlation between the Ki67 proliferation index and GLUT1 gene expression for the NETs (R = 0.34, P = 0.047), but no correlation with the hexokinases. FDG-PET identified foci in significantly...

  11. Exercise, GLUT4, and Skeletal Muscle Glucose Uptake

    DEFF Research Database (Denmark)

    Richter, Erik; Hargreaves, Mark

    2013-01-01

    Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon...... muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions....... Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose...

  12. GLUT4 trafficking in a test tube.

    Science.gov (United States)

    Ramm, Georg; James, David E

    2005-09-01

    Insulin regulates glucose transport in muscle and fat cells by stimulating the translocation of GLUT4 from intracellular vesicles to the plasma membrane. In this issue of Cell Metabolism, Holman and colleagues reconstitute this process in vitro, providing a system that promises new breakthroughs in our understanding of this important metabolic process.

  13. Genetic variants in promoters and coding regions of the muscle glycogen synthase and the insulin-responsive GLUT4 genes in NIDDM

    DEFF Research Database (Denmark)

    Bjørbaek, C; Echwald, Søren Morgenthaler; Hubricht, P

    1994-01-01

    To examine the hypothesis that variants in the regulatory or coding regions of the glycogen synthase (GS) and insulin-responsive glucose transporter (GLUT4) genes contribute to insulin-resistant glucose processing of muscle from non-insulin-dependent diabetes mellitus (NIDDM) patients, promoter...... volunteers. By applying inverse polymerase chain reaction and direct DNA sequencing, 532 base pairs (bp) of the GS promoter were identified and the transcriptional start site determined by primer extension. SSCP scanning of the promoter region detected five single nucleotide substitutions, positioned at 42......'-untranslated region, and the coding region of the GLUT4 gene showed four polymorphisms, all single nucleotide substitutions, positioned at -581, 1, 30, and 582. None of the three changes in the regulatory region of the gene had any major influence on expression of the GLUT4 gene in muscle. The variant at 582...

  14. Effect of vanadate on glucose transporter (GLUT4) intrinsic activity in skeletal muscle plasma membrane giant vesicles

    DEFF Research Database (Denmark)

    Kristiansen, S; Youn, J; Richter, Erik

    1996-01-01

    of vanadate (NaVO3) on glucose transporter (GLUT4) intrinsic activity (V(max) = intrinsic activity x [GLUT4 protein]) was studied in muscle plasma membrane giant vesicles. Giant vesicles (average diameter 7.6 microns) were produced by collagenase treatment of rat skeletal muscle. The vesicles were incubated......) 55% and 60%, respectively, compared with control. The plasma membrane GLUT4 protein content was not changed in response to vanadate. It is concluded that vanadate decreased glucose transport per GLUT4 (intrinsic activity). This finding suggests that regulation of glucose transport in skeletal muscle...

  15. Non-invasive assessment of animal exercise stress: real-time PCR of GLUT4, COX2, SOD1 and HSP70 in avalanche military dog saliva.

    Science.gov (United States)

    Diverio, S; Guelfi, G; Barbato, O; Di Mari, W; Egidi, M G; Santoro, M M

    2015-01-01

    Exercise has been shown to increase mRNA expression of a growing number of genes. The aim of this study was to assess if mRNA expression of the metabolism- and oxidative stress-related genes GLUT4 (glucose transporter 4), COX2 (cyclooxygenase 2), SOD1 (superoxide dismutase 1) and HSP70 (heat shock protein 70) in saliva changes following acute exercise stress in dogs. For this purpose, 12 avalanche dogs of the Italian Military Force Guardia di Finanza were monitored during simulation of a search for a buried person in an artificial avalanche area. Rectal temperature (RT) and saliva samples were collected the day before the trial (T0), immediately after the descent from a helicopter at the onset of a simulated avalanche search and rescue operation (T1), after the discovery of the buried person (T2) and 2 h later (T3). Expressions of GLUT4, SOD1, COX2 and HSP70 were measured by real-time PCR. The simulated avalanche search and rescue operation was shown to exert a significant effect on RT, as well as on the expression of all metabolism- and oxidative stress-related genes investigated, which peaked at T2. The observed expression patterns indicate an acute exercise stress-induced upregulation, as confirmed by the reductions in expression at T3. Moreover, our findings indicate that saliva is useful for assessing metabolism- and oxidative stress-related genes without the need for restraint, which could affect working dog performance.

  16. PI3K-GLUT4 Signal Pathway Associated with Effects of EX-B3 Electroacupuncture on Hyperglycemia and Insulin Resistance of T2DM Rats

    Directory of Open Access Journals (Sweden)

    Bing-Yan Cao

    2016-01-01

    Full Text Available Objectives. To explore electroacupuncture’s (EA’s effects on fasting blood glucose (FBG and insulin resistance of type 2 diabetic mellitus (T2DM model rats and give a possible explanation for the effects. Method. It takes high fat diet and intraperitoneal injection of streptozotocin (STZ, 30 mg/kg for model preparation. Model rats were randomly divided into T2DM Model group, EA weiwanxiashu (EX-B3 group, and sham EA group (n=12/group. EA (2 Hz continuous wave, 2 mA, 20 min/day, 6 days/week, 4 weeks was applied as intervention. FBG, area under curve (AUC of oral glucose tolerance test (OGTT, insulin resistance index (HOMA-IR, pancreatic B cell function index (HOMA-B, skeletal muscle phosphorylated phosphatidylinositol-3-kinase (PI3K, glucose transporter 4 (GLUT4, and membrane GLUT4 protein expression were measured. Results. EA weiwanxiashu (EX-B3 can greatly upregulate model rat’s significantly reduced skeletal muscle PI3K (Y607 and membrane GLUT4 protein expression (P<0.01, effectively reducing model rats’ FBG and AUC of OGTT (P<0.01. The effects are far superior to sham EA group. Conclusion. EA weiwanxiashu (EX-B3 can upregulate skeletal muscle phosphorylated PI3K protein expression, to stimulate membrane translocation of GLUT4 and thereby increase skeletal muscle glucose intake to treat T2DM.

  17. Prenatal Exposure to Sodium Arsenite Alters Placental Glucose 1, 3, and 4 Transporters in Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Daniela Sarahí Gutiérrez-Torres

    2015-01-01

    Full Text Available Inorganic arsenic (iAs exposure induces a decrease in glucose type 4 transporter (GLUT4 expression on the adipocyte membrane, which may be related to premature births and low birth weight infants in women exposed to iAs at reproductive age. The aim of this study was to analyze the effect of sodium arsenite (NaAsO2 exposure on GLUT1, GLUT3, and GLUT4 protein expression and on placental morphology. Female Balb/c mice (n=15 were exposed to 0, 12, and 20 ppm of NaAsO2 in drinking water from 8th to 18th day of gestation. Morphological changes and GLUT1, GLUT3, and GLUT4 expression were evaluated in placentas by immunohistochemical and image analysis and correlated with iAs and arsenical species concentration, which were quantified by atomic absorption spectroscopy. NaAsO2 exposure induced a significant decrease in fetal and placental weight (P<0.01 and increases in infarctions and vascular congestion. Whereas GLUT1 expression was unchanged in placentas from exposed group, GLUT3 expression was found increased. In contrast, GLUT4 expression was significantly lower (P<0.05 in placentas from females exposed to 12 ppm. The decrease in placental GLUT4 expression might affect the provision of adequate fetal nutrition and explain the low fetal weight observed in the exposed groups.

  18. (19)F-heptuloses as tools for the non-invasive imaging of GLUT2-expressing cells

    DEFF Research Database (Denmark)

    Malaisse, Willy J; Zhang, Ying; Louchami, Karim

    2012-01-01

    Suitable analogs of d-mannoheptulose are currently considered as possible tools for the non-invasive imaging of pancreatic islet insulin-producing cells. Here, we examined whether (19)F-heptuloses could be used for non-invasive imaging of GLUT2-expressing cells. After 20 min incubation, the uptake......-mannoheptulose in inhibiting insulin release. The 1-deoxy-1-fluoro-d-mannoheptulose and 3-deoxy-3-fluoro-d-mannoheptulose only marginally affected INS-1 cell viability. These findings are compatible with the view that selected (19)F-heptuloses may represent suitable tools for the non-invasive imaging of hepatocytes...

  19. 27-Hydroxycholesterol impairs neuronal glucose uptake through an IRAP/GLUT4 system dysregulation

    Science.gov (United States)

    Mateos, Laura; Maioli, Silvia; Ali, Zeina; Gulyás, Balázs; Winblad, Bengt; Savitcheva, Irina

    2017-01-01

    Hypercholesterolemia is associated with cognitively deteriorated states. Here, we show that excess 27-hydroxycholesterol (27-OH), a cholesterol metabolite passing from the circulation into the brain, reduced in vivo brain glucose uptake, GLUT4 expression, and spatial memory. Furthermore, patients exhibiting higher 27-OH levels had reduced 18F-fluorodeoxyglucose uptake. This interplay between 27-OH and glucose uptake revealed the engagement of the insulin-regulated aminopeptidase (IRAP). 27-OH increased the levels and activity of IRAP, countered the IRAP antagonist angiotensin IV (AngIV)–mediated glucose uptake, and enhanced the levels of the AngIV-degrading enzyme aminopeptidase N (AP-N). These effects were mediated by liver X receptors. Our results reveal a molecular link between cholesterol, brain glucose, and the brain renin-angiotensin system, all of which are affected in some neurodegenerative diseases. Thus, reducing 27-OH levels or inhibiting AP-N maybe a useful strategy in the prevention of the altered glucose metabolism and memory decline in these disorders. PMID:28213512

  20. Immunohistological expression of HIF-1α, GLUT-1, Bcl-2 and Ki-67 in consecutive biopsies during chemoradiotherapy in patients with rectal cancer

    DEFF Research Database (Denmark)

    Havelund, Birgitte Mayland; Sørensen, Flemming Brandt; Pløen, John

    2013-01-01

    receiving preoperative CRT (>50.4 Gy and Uracil/Tegafur). Immunohistological expressions of HIF-1α, GLUT-1, Bcl-2 and Ki-67 were investigated in biopsies taken before treatment, after 2, 4 and 6 weeks of CRT and in specimens from the operation. Decreasing expressions of HIF-1α, Bcl-2 and Ki-67 were observed...

  1. GLUT4 translocation is not impaired after acute exercise in skeletal muscle of women with obesity and polycystic ovary syndrome.

    Science.gov (United States)

    Dantas, Wagner Silva; Marcondes, José Antonio Miguel; Shinjo, Samuel Katsuyuki; Perandini, Luiz Augusto; Zambelli, Vanessa Olzon; Neves, Willian Das; Barcellos, Cristiano Roberto Grimaldi; Rocha, Michele Patrocínio; Yance, Viviane Dos Reis Vieira; Pereira, Renato Tavares Dos Santos; Murai, Igor Hisashi; Pinto, Ana Lucia De Sá; Roschel, Hamilton; Gualano, Bruno

    2015-11-01

    The aim of this study was to examine the effects of acute exercise on insulin signaling in skeletal muscle of women with polycystic ovary syndrome (PCOS) and controls (CTRL). Fifteen women with obesity and PCOS and 12 body mass index-matched CTRL participated in this study. Subjects performed a 40-min single bout of exercise. Muscle biopsies were performed before and 60 min after exercise. Selected proteins were assessed by Western blotting. CTRL, but not PCOS, showed a significant increase in PI3-k p85 and AS160 Thr 642 after a single bout of exercise (P = 0.018 and P = 0.018, respectively). Only PCOS showed an increase in Akt Thr 308 and AMPK phosphorylation after exercise (P = 0.018 and P = 0.018, respectively). Total GLUT4 expression was comparable between groups (P > 0.05). GLUT4 translocation tended to be significantly higher in both groups after exercise (PCOS: P = 0.093; CTRL: P = 0.091), with no significant difference between them (P > 0.05). A single bout of exercise elicited similar GLUT4 translocation in skeletal muscle of PCOS and CTRL, despite a slightly differential pattern of protein phosphorylation. The absence of impairment in GLUT4 translocation suggests that PCOS patients with obesity and insulin resistance may benefit from exercise training. © 2015 The Obesity Society.

  2. The FDG uptake and glucose transporter(GLUT-1) expression of the mediastinal nodes in the non-small cell lung cancer

    International Nuclear Information System (INIS)

    Baik, Hee Jong; Jung, Jin Haeng

    2000-12-01

    The aim of this study was to understand the mechanism of FDG uptake in the mediastinal nodes, and improve the accuracy of mediastinal staging of non-small cell lung cancer by PET. To evaluate factors determining the FDG uptake in mediastinal nodes, FDG-PET was performed preoperatively, and mediastinal dissection with pulmonary resection was done in 20 LSCLC patients. The GLUT-1 expression was studied by immunohistochemistry of paraffin-section from the mediastinal nodes(n=50, true positive 11, true negative 23, false positive 11, false negative 5) using the antiGLUT-1 antibody. The staining intensity of tumor(grade 0-4), percentage of tumor, level of follicular hyperplasia(grade 1-4), and staining intensity of follicle was also studied. The staining intensity of true positive nodes was higher than that of false negative group(Mann-Whitney test, P=0.07) in the metastased nodes. The level of follicular hyperplasia of false positive nodes was higher than that of true negative nodes in non-metastased nodes(P=0.02). This finding indicates that FN interpretation of mediastinal nodes by FDG-PET might be associated with low uptake of FDG due to low expression of GLUT-1, and that FP might be associated with high level of follicular hyperplasia as a reactive change to inflammatory and/or immune reaction

  3. GLUT-4 content in plasma membrane of muscle from patients with non-insulin-dependent diabetes mellitus

    DEFF Research Database (Denmark)

    Lund, S; Vestergaard, H; Andersen, P H

    1993-01-01

    The abundance of GLUT-4 protein in both total crude membrane and plasma membrane fractions of vastus lateralis muscle from 13 obese non-insulin-dependent diabetes mellitus (NIDDM) patients and 14 healthy subjects were examined in the fasting state and after supraphysiological hyperinsulinemia....... In the basal state the immunoreactive mass of GLUT-4 protein both in the crude membrane preparation and in the plasma membrane fraction was similar in NIDDM patients and control subjects. Moreover, in vivo insulin exposure neither for 30 min nor for 4 h had any impact on the content of GLUT-4 protein in plasma...... membranes. With the use of the same methodology, antibody, and achieving the same degree of plasma membrane purification and recovery, we found, however, that intraperitoneal administration of insulin to 7-wk-old rats within 30 min increased the content of GLUT-4 protein more than twofold (P

  4. Glucose transporter expression in human skeletal muscle fibers

    DEFF Research Database (Denmark)

    Gaster, M; Handberg, A; Beck-Nielsen, H

    2000-01-01

    , but its expression is markedly reduced around birth and is further reduced to undetectable levels within the first year of life; 2) GLUT-3 protein expression appears at 18 wk of gestation and disappears after birth; and 3) GLUT-4 protein is diffusely expressed in muscle cells throughout gestation, whereas...... after birth, the characteristic subcellular localization is as seen in adult muscle fibers. Our results show that GLUT-1, GLUT-3, and GLUT-4 seem to be of importance during muscle fiber growth and development. GLUT-5 protein was undetectable in fetal and adult skeletal muscle fibers. In adult muscle...... amplification (TSA) technique to detect the localization of glucose transporter expression in human skeletal muscle. We found expression of GLUT-1, GLUT-3, and GLUT-4 in developing human muscle fibers showing a distinct expression pattern. 1) GLUT-1 is expressed in human skeletal muscle cells during gestation...

  5. Pretreatment HIF-1α and GLUT-1 expressions do not correlate with outcome after preoperative chemoradiotherapy in rectal cancer

    DEFF Research Database (Denmark)

    Havelund, Birgitte Mayland; Sørensen, Flemming Brandt; Lindebjerg, Jan

    2011-01-01

    The aim of the present study was to investigate hypoxia-inducible factor 1α (HIF-1α) and glucose transporter-1 (GLUT-1) expressions as predictors of response and survival after chemoradiotherapy in pretreatment biopsy specimens from patients with rectal cancer.......The aim of the present study was to investigate hypoxia-inducible factor 1α (HIF-1α) and glucose transporter-1 (GLUT-1) expressions as predictors of response and survival after chemoradiotherapy in pretreatment biopsy specimens from patients with rectal cancer....

  6. Insulin stimulates translocation of human GLUT4 to the membrane in fat bodies of transgenic Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Georgeta Crivat

    Full Text Available The fruit fly Drosophila melanogaster is an excellent model system for studies of genes controlling development and disease. However, its applicability to physiological systems is less clear because of metabolic differences between insects and mammals. Insulin signaling has been studied in mammals because of relevance to diabetes and other diseases but there are many parallels between mammalian and insect pathways. For example, deletion of Drosophila Insulin-Like Peptides resulted in 'diabetic' flies with elevated circulating sugar levels. Whether this situation reflects failure of sugar uptake into peripheral tissues as seen in mammals is unclear and depends upon whether flies harbor the machinery to mount mammalian-like insulin-dependent sugar uptake responses. Here we asked whether Drosophila fat cells are competent to respond to insulin with mammalian-like regulated trafficking of sugar transporters. Transgenic Drosophila expressing human glucose transporter-4 (GLUT4, the sugar transporter expressed primarily in insulin-responsive tissues, were generated. After expression in fat bodies, GLUT4 intracellular trafficking and localization were monitored by confocal and total internal reflection fluorescence microscopy (TIRFM. We found that fat body cells responded to insulin with increased GLUT4 trafficking and translocation to the plasma membrane. While the amplitude of these responses was relatively weak in animals reared on a standard diet, it was greatly enhanced in animals reared on sugar-restricted diets, suggesting that flies fed standard diets are insulin resistant. Our findings demonstrate that flies are competent to mobilize translocation of sugar transporters to the cell surface in response to insulin. They suggest that Drosophila fat cells are primed for a response to insulin and that these pathways are down-regulated when animals are exposed to constant, high levels of sugar. Finally, these studies are the first to use TIRFM to

  7. Insulin Stimulates Translocation of Human GLUT4 to the Membrane in Fat Bodies of Transgenic Drosophila melanogaster

    Science.gov (United States)

    Crivat, Georgeta; Lizunov, Vladimir A.; Li, Caroline R.; Stenkula, Karin G.; Zimmerberg, Joshua; Cushman, Samuel W.; Pick, Leslie

    2013-01-01

    The fruit fly Drosophila melanogaster is an excellent model system for studies of genes controlling development and disease. However, its applicability to physiological systems is less clear because of metabolic differences between insects and mammals. Insulin signaling has been studied in mammals because of relevance to diabetes and other diseases but there are many parallels between mammalian and insect pathways. For example, deletion of Drosophila Insulin-Like Peptides resulted in ‘diabetic’ flies with elevated circulating sugar levels. Whether this situation reflects failure of sugar uptake into peripheral tissues as seen in mammals is unclear and depends upon whether flies harbor the machinery to mount mammalian-like insulin-dependent sugar uptake responses. Here we asked whether Drosophila fat cells are competent to respond to insulin with mammalian-like regulated trafficking of sugar transporters. Transgenic Drosophila expressing human glucose transporter-4 (GLUT4), the sugar transporter expressed primarily in insulin-responsive tissues, were generated. After expression in fat bodies, GLUT4 intracellular trafficking and localization were monitored by confocal and total internal reflection fluorescence microscopy (TIRFM). We found that fat body cells responded to insulin with increased GLUT4 trafficking and translocation to the plasma membrane. While the amplitude of these responses was relatively weak in animals reared on a standard diet, it was greatly enhanced in animals reared on sugar-restricted diets, suggesting that flies fed standard diets are insulin resistant. Our findings demonstrate that flies are competent to mobilize translocation of sugar transporters to the cell surface in response to insulin. They suggest that Drosophila fat cells are primed for a response to insulin and that these pathways are down-regulated when animals are exposed to constant, high levels of sugar. Finally, these studies are the first to use TIRFM to monitor insulin

  8. Effects of contraction on localization of GLUT4 and v-SNARE isoforms in rat skeletal muscle

    DEFF Research Database (Denmark)

    Rose, Adam John; Jeppesen, Jacob; Kiens, Bente

    2009-01-01

    In skeletal muscle, contractions increase glucose uptake due to a translocation of GLUT4 glucose transporters from intracellular storage sites to the surface membrane. Vesicle associated membrane proteins (VAMPs) are believed to play an important role in docking and fusion of the GLUT4 transporters...... at the surface membrane. However, knowledge about which VAMP isoforms in fact co-localize with GLUT4 vesicles in mature skeletal muscle and whether they translocate during muscle contractions is incomplete. The aim of the present study was to further identify VAMP isoforms which are associated with GLUT4......, there was a redistribution of VAMP2 (+240 +/- 40%), VAMP5 (+79 +/- 9%) and VAMP7 (+79 +/- 29%), but not VAMP3, to fractions enriched in heavy membranes away from low density membranes (-49 +/- 10%, -54 +/- 9%, -14 +/- 11%, respectively) in contracted versus resting muscle. In summary, VAMP2, VAMP3, VAMP5 and VAMP7 co...

  9. Dual role for myosin II in GLUT4-mediated glucose uptake in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Fulcher, F. Kent; Smith, Bethany T.; Russ, Misty; Patel, Yashomati M.

    2008-01-01

    Insulin-stimulated glucose uptake requires the activation of several signaling pathways to mediate the translocation and fusion of GLUT4 vesicles to the plasma membrane. Our previous studies demonstrated that GLUT4-mediated glucose uptake is a myosin II-dependent process in adipocytes. The experiments described in this report are the first to show a dual role for the myosin IIA isoform specifically in regulating insulin-stimulated glucose uptake in adipocytes. We demonstrate that inhibition of MLCK but not RhoK results in impaired insulin-stimulated glucose uptake. Furthermore, our studies show that insulin specifically stimulates the phosphorylation of the RLC associated with the myosin IIA isoform via MLCK. In time course experiments, we determined that GLUT4 translocates to the plasma membrane prior to myosin IIA recruitment. We further show that recruitment of myosin IIA to the plasma membrane requires that myosin IIA be activated via phosphorylation of the RLC by MLCK. Our findings also reveal that myosin II is required for proper GLUT4-vesicle fusion at the plasma membrane. We show that once at the plasma membrane, myosin II is involved in regulating the intrinsic activity of GLUT4 after insulin stimulation. Collectively, our results are the first to reveal that myosin IIA plays a critical role in mediating insulin-stimulated glucose uptake in 3T3-LI adipocytes, via both GLUT4 vesicle fusion at the plasma membrane and GLUT4 activity

  10. O exercício físico é capaz de melhorar expressão de AMPK e GLUT4 em músculo esquelético de ratos alcoolistas e/ou tabagistas

    OpenAIRE

    Florido Neto, Armando Ribeiro [UNESP

    2015-01-01

    Alcohol and cigarettes are the lawful psychoactive drugs more consumed in the world, usually being consumed in association. Metabolic alterations are linked to alcohol consumption and tobacco use involving impairment in the expression of proteins related to cellular metabolism. The objective of this study was to evaluate if the regular physical exercise can promote positive effects on the possible impairment related to expression of GLUT4 and AMPK in the skeletal muscle of smoker and/or alcoh...

  11. Effect of curcumin Extract on Ttranslocation of Glut 4 in C2C12 Myotubes

    Directory of Open Access Journals (Sweden)

    J Zavarreza

    2013-06-01

    Full Text Available Introduction: Curcumin is a major phenolic compound of Curcuma longa, which has long been used in traditional Indian medicine. Recently, curcumin has been reported to have antihyperglycemic activity in animal models. However, the molecular basis of this action has not been adequatedly described. In the present study the antihyperglycemic effect of curcumin was examined using C2C12 myoblast cells. Methods: The effects of curcumin were investigated in C2C12 myotubes by treating the cells with 40 µM of curcumin for 1.5 h. C2C12 myotubes were homogenized and the subcellular fractionation was prepared using ultracentrifugation; Then protein assay was performed using Bradford method and Glut4 determination was done using SDS-PAGE. Moreover, western immunoblotting techniques were exerted for semi-quantitative measurement. Data analysis was performed via gene tools software of Gel documentation and SPSS. An ANOVA test was used to compare three groups together. Results: Comparison of Glut4 levels in C2C12 myotubes showed that myotubes which were exposed to1.5 hours of 40 µM curcunin had higher Glut4 percentages in both cytosolic and membrane fractions and Glut4 percentages were significant with a confidence interval (CI of 95% ( P<0.05 . Conclusion: The study results showed that curcumin can strongly induce the increase of Glut4 translocation in differentiated C2C12 cells, indicating its possible regulatory role in the glucose metabolism of skeletal muscle cells

  12. Kinetics of contraction-induced GLUT4 translocation in skeletal muscle fibers from living mice

    DEFF Research Database (Denmark)

    Lauritzen, Hans Peter M. Mortensen; Galbo, Henrik; Toyoda, Taro

    2010-01-01

    Exercise is an important strategy for the treatment of type 2 diabetes. This is due in part to an increase in glucose transport that occurs in the working skeletal muscles. Glucose transport is regulated by GLUT4 translocation in muscle, but the molecular machinery mediating this process is poorl...... understood. The purpose of this study was to 1) use a novel imaging system to elucidate the kinetics of contraction-induced GLUT4 translocation in skeletal muscle and 2) determine the function of AMP-activated protein kinase alpha2 (AMPKalpha2) in this process.......Exercise is an important strategy for the treatment of type 2 diabetes. This is due in part to an increase in glucose transport that occurs in the working skeletal muscles. Glucose transport is regulated by GLUT4 translocation in muscle, but the molecular machinery mediating this process is poorly...

  13. Metformin ameliorates diabetes but does not normalize the decreased GLUT 4 content in skeletal muscle of obese (fa/fa) Zucker rats

    DEFF Research Database (Denmark)

    Handberg, A; Kayser, L; Høyer, P E

    1993-01-01

    We studied the expression of the glucose transporter GLUT 4 in the soleus and red gastrocnemius muscles from obese, diabetic (fa/fa) Zucker rats compared to their lean littermates (Fa/-), with and without treatment with the antidiabetic drug metformin. In the untreated groups of rats, the GLUT 4...... content in a crude membrane fraction of both the soleus and the red gastrocnemius muscles were significantly lower in the obese (fa/fa) rats (3.46 +/- 0.28 vs. 6.04 +/- 0.41, p ... the same rats were confirmed by quantitative immunofluorescence microscopy, and the results were significantly correlated with the results obtained from quantitative immunoblotting (rho = 0.70, p fa/fa rats could contribute to the well-established insulin...

  14. GLUT4 in cultured skeletal myotubes is segregated from the transferrin receptor and stored in vesicles associated with TGN

    DEFF Research Database (Denmark)

    Ralston, E; Ploug, Thorkil

    1996-01-01

    of the constitutive endosomal-lysosomal pathway. To address this question, we have investigated the localization of the endogenous GLUT4 in non-stimulated skeletal myotubes from the cell line C2, by immunofluorescence and immunoelectron microscopy. We have used a panel of antibodies to markers of the Golgi complex...... and in vesicles just beyond, i.e. in the structures that constitute the trans-Golgi network (TGN). In myotubes treated with brefeldin A, the immunofluorescence pattern of GLUT4 is modified, but it differs from both Golgi complex markers and TGN38. Instead, it resembles the pattern of the transferrin receptor...... to the GLUT4-containing tubulo-vesicular elements. In brefeldin A-treated cells, a network of tubules of approximately 70 nm diameter, studded with varicosities, stains for both GLUT4 and transferrin receptor, suggesting that brefeldin A has caused fusion of the transferrin receptor and GLUT4-containing...

  15. Associations Between PET Textural Features and GLUT1 Expression, and the Prognostic Significance of Textural Features in Lung Adenocarcinoma.

    Science.gov (United States)

    Koh, Young Wha; Park, Seong Yong; Hyun, Seung Hyup; Lee, Su Jin

    2018-02-01

    We evaluated the association between positron emission tomography (PET) textural features and glucose transporter 1 (GLUT1) expression level and further investigated the prognostic significance of textural features in lung adenocarcinoma. We evaluated 105 adenocarcinoma patients. We extracted texture-based PET parameters of primary tumors. Conventional PET parameters were also measured. The relationships between PET parameters and GLUT1 expression levels were evaluated. The association between PET parameters and overall survival (OS) was assessed using Cox's proportional hazard regression models. In terms of PET textural features, tumors expressing high levels of GLUT1 exhibited significantly lower coarseness, contrast, complexity, and strength, but significantly higher busyness. On univariate analysis, the metabolic tumor volume, total lesion glycolysis, contrast, busyness, complexity, and strength were significant predictors of OS. Multivariate analysis showed that lower complexity (HR=2.017, 95%CI=1.032-3.942, p=0.040) was independently associated with poorer survival. PET textural features may aid risk stratification in lung adenocarcinoma patients. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  16. Rosiglitazone stimulates the release and synthesis of insulin by enhancing GLUT-2, glucokinase and BETA2/NeuroD expression

    International Nuclear Information System (INIS)

    Kim, Hyo-Sup; Noh, Jung-Hyun; Hong, Seung-Hyun; Hwang, You-Cheol; Yang, Tae-Young; Lee, Myung-Shik; Kim, Kwang-Won; Lee, Moon-Kyu

    2008-01-01

    Peroxisome proliferator-activated receptor (PPAR)-γ is a member of the nuclear receptor superfamily, and its ligands, the thiazolidinediones, might directly stimulate insulin release and insulin synthesis in pancreatic β-cells. In the present study, we examined the effects of rosiglitazone (RGZ) on insulin release and synthesis in pancreatic β-cell (INS-1). Insulin release and synthesis were stimulated by treatment with RGZ for 24 h. RGZ upregulated the expressions of GLUT-2 and glucokinase (GCK). Moreover, it was found that RGZ increased the expression of BETA2/NeuroD gene which could regulate insulin gene expression. These results suggest that RGZ could stimulate the release and synthesis of insulin through the upregulation of GLUT-2, GCK, and BETA2/NeuroD gene expression

  17. Fruit extracts of Momordica charantia potentiate glucose uptake and up-regulate Glut-4, PPAR gamma and PI3K.

    Science.gov (United States)

    Kumar, Ramadhar; Balaji, S; Uma, T S; Sehgal, P K

    2009-12-10

    Momordica charantia fruit is a widely used traditional medicinal herb as, anti-diabetic, anti-HIV, anti-ulcer, anti-inflammatory, anti-leukemic, anti-microbial, and anti-tumor. The present study is undertaken to investigate the possible mode of action of fruit extracts derived from Momordica charantia (MC) and study its pharmacological effects for controlling diabetic mellitus. Effects of aqueous and chloroform extracts of Momordica charantia fruit on glucose uptake and up-regulation of glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPAR gamma) and phosphatidylinositol-3 kinase (PI3K), were investigated to show its efficacy as a hypoglycaemic agent. Dose dependent glucose uptake assay was performed on L6 myotubes using 2-deoxy-D-[1-(3)H] glucose. Up-regulatory effects of the extracts on the mRNA expression level of Glut-4, PPAR gamma and PI3K have been studied. The association of Momordica charantia with the aqueous and chloroform extracts of Momordica charantia fruit at 6 microg/ml has shown significant up-regulatory effect, respectively, by 3.6-, 2.8- and 3.8-fold on the battery of targets Glut-4, PPAR gamma and PI3K involved in glucose transport. The up-regulation of glucose uptake was comparable with insulin and rosiglitazone which was approximately 2-fold over the control. Moreover, the inhibitory effect of the cyclohexamide on Momordica charantia fruit extract mediated glucose uptake suggested the requirement of new protein synthesis for the enhanced glucose uptake. This study demonstrated the significance of Glut-4, PPAR gamma and PI3K up-regulation by Momordica charantia in augmenting the glucose uptake and homeostasis.

  18. Small G proteins in insulin action: Rab and Rho families at the crossroads of signal transduction and GLUT4 vesicle traffic.

    Science.gov (United States)

    Ishikura, S; Koshkina, A; Klip, A

    2008-01-01

    Insulin stimulates glucose uptake into muscle and adipose tissues through glucose transporter 4 (GLUT4). GLUT4 cycles between the intracellular compartments and the plasma membrane. GLUT4 traffic-regulating insulin signals are largely within the insulin receptor-insulin receptor substrate-phosphatidylinositol 3-kinase (IR-IRS-PI3K) axis. In muscle cells, insulin signal bifurcates downstream of the PI3K into one arm leading to the activation of the Ser/Thr kinases Akt and atypical protein kinase C, and another leading to the activation of Rho family protein Rac1 leading to actin remodelling. Activated Akt inactivates AS160, a GTPase-activating protein for Rab family small G proteins. Here we review the roles of Rab and Rho proteins, particularly Rab substrates of AS160 and Rac1, in insulin-stimulated GLUT4 traffic. We discuss: (1) how distinct steps in GLUT4 traffic may be regulated by discrete Rab proteins, and (2) the importance of Rac1 activation in insulin-induced actin remodelling in muscle cells, a key element for the net gain in surface GLUT4.

  19. GLUT3 is present in Clone 9 liver cells and translocates to the plasma membrane in response to insulin.

    Science.gov (United States)

    Defries, Danielle M; Taylor, Carla G; Zahradka, Peter

    2016-08-26

    Clone 9 cells have been reported to express only the GLUT1 facilitative glucose transporter; however, previous studies have not examined Clone 9 cells for GLUT3 content. The current study sought to profile the presence of glucose transporters in Clone 9 cells, H4IIE hepatoma cells, and L6 myoblasts and myotubes. While the other cell types contained the expected complement of transporters, Clone 9 cells had GLUT3 which was previously not reported. Interestingly, both GLUT3 mRNA and protein were detected in Clone 9 cells, but only mRNA for GLUT1 was detected. Glucose transport in Clone 9 cells was insulin-sensitive in a concentration-dependent manner, concomitant with the presence of GLUT3 in the plasma membrane after insulin treatment. Although basal glucose uptake was unaffected, insulin-stimulated glucose uptake was abolished with siRNA-mediated GLUT3 knockdown. These results contradict previous reports that Clone 9 cells exclusively express GLUT1 and suggest GLUT3 is a key insulin-sensitive glucose transporter required for insulin-stimulated glucose uptake by Clone 9 cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. AICAR administration affects glucose metabolism by upregulating the novel glucose transporter, GLUT8, in equine skeletal muscle.

    Science.gov (United States)

    de Laat, M A; Robinson, M A; Gruntmeir, K J; Liu, Y; Soma, L R; Lacombe, V A

    2015-09-01

    Equine metabolic syndrome is characterized by obesity and insulin resistance (IR). Currently, there is no effective pharmacological treatment for this insidious disease. Glucose uptake is mediated by a family of glucose transporters (GLUT), and is regulated by insulin-dependent and -independent pathways, including 5-AMP-activated protein kinase (AMPK). Importantly, the activation of AMPK, by 5-aminoimidazole-4-carboxamide-1-D-ribofuranoside (AICAR) stimulates glucose uptake in both healthy and diabetic humans. However, whether AICAR promotes glucose uptake in horses has not been established. It is hypothesized that AICAR administration would enhance glucose transport in equine skeletal muscle through AMPK activation. In this study, the effect of an intravenous AICAR infusion on blood glucose and insulin concentrations, as well as on GLUT expression and AMPK activation in equine skeletal muscle (quantified by Western blotting) was examined. Upon administration, plasma AICAR rapidly reached peak concentration. Treatment with AICAR resulted in a decrease (P change in lactate concentration. The ratio of phosphorylated to total AMPK was increased (P managing IR requires investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Infection of CD4+ T lymphocytes by the human T cell leukemia virus type 1 is mediated by the glucose transporter GLUT-1: Evidence using antibodies specific to the receptor's large extracellular domain

    International Nuclear Information System (INIS)

    Jin, Qingwen; Agrawal, Lokesh; VanHorn-Ali, Zainab; Alkhatib, Ghalib

    2006-01-01

    To analyze HTLV-1 cytotropism, we developed a highly sensitive vaccinia virus-based assay measuring activation of a reporter gene upon fusion of two distinct cell populations. We used this system in a functional cDNA screening to isolate and confirm that the glucose transporter protein 1 (GLUT-1) is a receptor for HTLV-1. GLUT-1 is a ubiquitously expressed plasma membrane glycoprotein with 12 transmembrane domains and 6 extracellular loops (ECL). We demonstrate for the first time that peptide antibodies (GLUT-IgY) raised in chicken to the large extracellular loop (ECL1) detect GLUT-1 at the cell surface and inhibit envelope (Env)-mediated fusion and infection. Efficient GLUT-IgY staining was detected with peripheral blood CD4 + lymphocytes purified by positive selection. Further, GLUT-IgY caused efficient inhibition of Env-mediated fusion and infection of CD4 + T and significantly lower inhibition of CD8 + T lymphocytes. The specificity of GLUT-IgY antibodies to GLUT-1 was demonstrated by ECL1 peptide competition studies. Grafting ECL1 of GLUT-1 onto the receptor-negative GLUT-3 conferred significant receptor activity. In contrast, grafting ECL1 of GLUT-3 onto GLUT-1 resulted in a significant loss of the receptor activity. The ECL1-mediated receptor activity was efficiently blocked with four different human monoclonal antibody (HMab) to HTLV-1 Env. The ECL1-derived peptide blocked HTLV-1 Env-mediated fusion with several nonhuman mammalian cell lines. The results demonstrate the utilization of cell surface GLUT-1 in HTLV-1 infection of CD4 + T lymphocytes and implicate a critical role for the ECL1 region in viral tropism

  2. Kinetics of contraction-induced GLUT4 translocation in skeletal muscle fibers from living mice

    DEFF Research Database (Denmark)

    Lauritzen, Hans Peter M. Mortensen; Galbo, Henrik; Toyoda, Taro

    2010-01-01

    Exercise is an important strategy for the treatment of type 2 diabetes. This is due in part to an increase in glucose transport that occurs in the working skeletal muscles. Glucose transport is regulated by GLUT4 translocation in muscle, but the molecular machinery mediating this process is poorly...... understood. The purpose of this study was to 1) use a novel imaging system to elucidate the kinetics of contraction-induced GLUT4 translocation in skeletal muscle and 2) determine the function of AMP-activated protein kinase alpha2 (AMPKalpha2) in this process....

  3. Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle.

    Science.gov (United States)

    Castorena, Carlos M; Arias, Edward B; Sharma, Naveen; Bogan, Jonathan S; Cartee, Gregory D

    2015-02-01

    To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[(3)H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater (P contraction-stimulated glucose uptake. Copyright © 2015 the American Physiological Society.

  4. Regulation of human trophoblast GLUT1 glucose transporter by insulin-like growth factor I (IGF-I.

    Directory of Open Access Journals (Sweden)

    Marc U Baumann

    Full Text Available Glucose transport to the fetus across the placenta takes place via glucose transporters in the opposing faces of the barrier layer, the microvillous and basal membranes of the syncytiotrophoblast. While basal membrane content of the GLUT1 glucose transporter appears to be the rate-limiting step in transplacental transport, the factors regulating transporter expression and activity are largely unknown. In view of the many studies showing an association between IGF-I and fetal growth, we investigated the effects of IGF-I on placental glucose transport and GLUT1 transporter expression. Treatment of BeWo choriocarcinoma cells with IGF-I increased cellular GLUT1 protein. There was increased basolateral (but not microvillous uptake of glucose and increased transepithelial transport of glucose across the BeWo monolayer. Primary syncytial cells treated with IGF-I also demonstrated an increase in GLUT1 protein. Term placental explants treated with IGF-I showed an increase in syncytial basal membrane GLUT1 but microvillous membrane GLUT1 was not affected. The placental dual perfusion model was used to assess the effects of fetally perfused IGF-I on transplacental glucose transport and syncytial GLUT1 content. In control perfusions there was a decrease in transplacental glucose transport over the course of the perfusion, whereas in tissues perfused with IGF-I through the fetal circulation there was no change. Syncytial basal membranes from IGF-I perfused tissues showed an increase in GLUT1 content. These results demonstrate that IGF-I, whether acting via microvillous or basal membrane receptors, increases the basal membrane content of GLUT1 and up-regulates basal membrane transport of glucose, leading to increased transepithelial glucose transport. These observations provide a partial explanation for the mechanism by which IGF-I controls nutrient supply in the regulation of fetal growth.

  5. Gene Expression of Glucose Transporter 1 (GLUT1, Hexokinase 1 and Hexokinase 2 in Gastroenteropancreatic Neuroendocrine Tumors: Correlation with F-18-fluorodeoxyglucose Positron Emission Tomography and Cellular Proliferation

    Directory of Open Access Journals (Sweden)

    Andreas Kjaer

    2013-10-01

    Full Text Available Neoplastic tissue exhibits high glucose utilization and over-expression of glucose transporters (GLUTs and hexokinases (HKs, which can be imaged by 18F-Fluorodeoxyglucose-positron emission tomography (FDG-PET. The aim of the present study was to investigate the expression of glycolysis-associated genes and to compare this with FDG-PET imaging as well as with the cellular proliferation index in two cancer entities with different malignant potential. Using real-time PCR, gene expression of GLUT1, HK1 and HK2 were studied in 34 neuroendocrine tumors (NETs in comparison with 14 colorectal adenocarcinomas (CRAs. The Ki67 proliferation index and, when available, FDG-PET imaging was compared with gene expression. Overexpression of GLUT1 gene expression was less frequent in NETs (38% compared to CRAs (86%, P = 0.004. HK1 was overexpressed in 41% and 71% of NETs and CRAs, respectively (P = 0.111 and HK2 was overexpressed in 50% and 64% of NETs and CRAs, respectively (P = 0.53. There was a significant correlation between the Ki67 proliferation index and GLUT1 gene expression for the NETs (R = 0.34, P = 0.047, but no correlation with the hexokinases. FDG-PET identified foci in significantly fewer NETs (36% than CRAs (86%, (P = 0.04. The gene expression results, with less frequent GLUT1 and HK1 upregulation in NETs, confirmed the lower metabolic activity of NETs compared to the more aggressive CRAs. In accordance with this, fewer NETs were FDG-PET positive compared to CRA tumors and FDG uptake correlated with GLUT1 gene expression.

  6. A potential link between insulin signaling and GLUT4 translocation: Association of Rab10-GTP with the exocyst subunit Exoc6/6b

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Hiroyuki; Peck, Grantley R. [Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 (United States); Blachon, Stephanie [Hybrigenics Services SAS, 3-5 Impasse Reille, 75014 Paris (France); Lienhard, Gustav E., E-mail: gustav.e.lienhard@dartmouth.edu [Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 (United States)

    2015-09-25

    Insulin increases glucose transport in fat and muscle cells by stimulating the exocytosis of specialized vesicles containing the glucose transporter GLUT4. This process, which is referred to as GLUT4 translocation, increases the amount of GLUT4 at the cell surface. Previous studies have provided evidence that insulin signaling increases the amount of Rab10-GTP in the GLUT4 vesicles and that GLUT4 translocation requires the exocyst, a complex that functions in the tethering of vesicles to the plasma membrane, leading to exocytosis. In the present study we show that Rab10 in its GTP form binds to Exoc6 and Exoc6b, which are the two highly homologous isotypes of an exocyst subunit, that both isotypes are found in 3T3-L1 adipocytes, and that knockdown of Exoc6, Exoc6b, or both inhibits GLUT4 translocation in 3T3-L1 adipocytes. These results suggest that the association of Rab10-GTP with Exoc6/6b is a molecular link between insulin signaling and the exocytic machinery in GLUT4 translocation. - Highlights: • Insulin stimulates the fusion of vesicles containing GLUT4 with the plasma membrane. • This requires vesicular Rab10-GTP and the exocyst plasma membrane tethering complex. • We find that Rab10-GTP associates with the Exoc6 subunit of the exocyst. • We find that knockdown of Exoc6 inhibits fusion of GLUT4 vesicles with the membrane. • The interaction of Rab10-GTP with Exoc6 potentially links signaling to exocytosis.

  7. Action of Phytochemicals on Insulin Signaling Pathways Accelerating Glucose Transporter (GLUT4 Protein Translocation

    Directory of Open Access Journals (Sweden)

    Abu Sadat Md Sayem

    2018-01-01

    Full Text Available Diabetes is associated with obesity, generally accompanied by a chronic state of oxidative stress and redox imbalances which are implicated in the progression of micro- and macro-complications like heart disease, stroke, dementia, cancer, kidney failure and blindness. All these complications rise primarily due to consistent high blood glucose levels. Insulin and glucagon help to maintain the homeostasis of glucose and lipids through signaling cascades. Pancreatic hormones stimulate translocation of the glucose transporter isoform 4 (GLUT4 from an intracellular location to the cell surface and facilitate the rapid insulin-dependent storage of glucose in muscle and fat cells. Malfunction in glucose uptake mechanisms, primarily contribute to insulin resistance in type 2 diabetes. Plant secondary metabolites, commonly known as phytochemicals, are reported to have great benefits in the management of type 2 diabetes. The role of phytochemicals and their action on insulin signaling pathways through stimulation of GLUT4 translocation is crucial to understand the pathogenesis of this disease in the management process. This review will summarize the effects of phytochemicals and their action on insulin signaling pathways accelerating GLUT4 translocation based on the current literature.

  8. De-phosphorylation of TRα-1 by p44/42 MAPK inhibition enhances T3-mediated GLUT5 gene expression in the intestinal cell line Caco-2 cells

    International Nuclear Information System (INIS)

    Mochizuki, Kazuki; Sakaguchi, Naomi; Takabe, Satsuki; Goda, Toshinao

    2007-01-01

    Thyroid hormone and p44/42 MAPK inactivation are important in intestinal differentiation. We demonstrated not only that treatment with p44/42 MAPK inhibitor U0126 in intestinal cell line Caco-2 cells reduced the phosphorylation of serine and threonine residues of TRα-1, but also that T 3 and U0126 synergistically induced GLUT5 gene expression. EMSA demonstrated that the binding activity of TRα-1-RXR heterodimer on GLUT5-TRE in nuclear proteins of Caco-2 cells was synergistically enhanced by co-incubation in vitro with T 3 and CIAP, which strongly de-phosphorylates proteins. ChIP and transfection assays revealed that co-treatment of T 3 and U0126 induces TRα-1-RXR binding to GLUT5-TRE on the human GLUT5 enhancer region, and recruitment of the transcriptional complex in cells. These results suggest that inactivation of p44/42 MAPK enhances T 3 -induced GLUT5 gene expression in Caco-2 cells through increasing TRα-1 transactivity and binding activity to the GLUT5-TRE, probably due to de-phosphorylation of TRα-1

  9. Sodium-glucose co-transporter (SGLT) and glucose transporter (GLUT) expression in the kidney of type 2 diabetic subjects.

    Science.gov (United States)

    Norton, Luke; Shannon, Christopher E; Fourcaudot, Marcel; Hu, Cheng; Wang, Niansong; Ren, Wei; Song, Jun; Abdul-Ghani, Muhammad; DeFronzo, Ralph A; Ren, Jimmy; Jia, Weiping

    2017-09-01

    The sodium-glucose co-transporters (SGLTs) are responsible for the tubular reabsorption of filtered glucose from the kidney into the bloodstream. The inhibition of SGLT2-mediated glucose reabsorption is a novel and highly effective strategy to alleviate hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). However, the effectiveness of SGLT2 inhibitor therapy is diminished due, in part, to a compensatory increase in the maximum reabsorptive capacity (Tm) for glucose in patients with T2DM. We hypothesized that this increase in Tm could be explained by an increase in the tubular expression of SGLT and glucose transporters (GLUT) in these patients. To examine this, we obtained human kidney biopsy specimens from patients with or without T2DM and examined the mRNA expression of SGLTs and GLUTs. The expression of SGLT1 is markedly increased in the kidney of patients with T2DM, and SGLT1 mRNA is highly and significantly correlated with fasting and postprandial plasma glucose and HbA1c. In contrast, our data demonstrate that the levels of SGLT2 and GLUT2 mRNA are downregulated in diabetic patients, but not to a statistically significant level. These important findings are clinically significant and may have implications for the treatment of T2DM using strategies that target SGLT transporters in the kidney. © 2017 John Wiley & Sons Ltd.

  10. GLUT-1-independent infection of the glioblastoma/astroglioma U87 cells by the human T cell leukemia virus type 1

    International Nuclear Information System (INIS)

    Jin Qingwen; Agrawal, Lokesh; VanHorn-Ali, Zainab; Alkhatib, Ghalib

    2006-01-01

    The human glucose transporter protein 1 (GLUT-1) functions as a receptor for human T cell leukemia virus (HTLV). GLUT-1 is a twelve-transmembrane cell surface receptor with six extracellular (ECL) and seven intracellular domains. To analyze HTLV-1 cytotropism, we utilized polyclonal antibodies to a synthetic peptide corresponding to the large extracellular domain of GLUT-1. The antibodies caused significant blocking of envelope (Env)-mediated fusion and pseudotyped virus infection of HeLa cells but had no significant effect on infection of U87 cells. This differential effect correlated with the detection of high-level surface expression of GLUT-1 on HeLa cells and very weak staining of U87 cells. To investigate this in terms of viral cytotropism, we cloned GLUT-1 cDNA from U87 cells and isolated two different versions of cDNA clones: the wild-type sequence (encoding 492 residues) and a mutant cDNA with a 5-base pair deletion (GLUT-1Δ5) between nucleotides 1329 and 1333. The deletion, also detected in genomic DNA, resulted in a frame-shift and premature termination producing a truncated protein of 463 residues. Transfection of the wild-type GLUT-1 but not GLUT-1Δ5 cDNA into CHO cells resulted in efficient surface expression of the human GLUT-1. Co-expression of GLUT-1 with GLUT-1Δ5 produces a trans-inhibition by GLUT-1Δ5 of GLUT-1-mediated HTLV-1 envelope (Env)-mediated fusion. Co-immunoprecipitation experiments demonstrated physical interaction of the wild-type and mutant proteins. Northern blot and RT-PCR analyses demonstrated lower GLUT-1 RNA expression in U87 cells. We propose two mechanisms to account for the impaired cell surface expression of GLUT-1 on U87 cells: low GLUT-1 RNA expression and the formation of GLUT-1/GLUT-1Δ5 heterodimers that are retained intracellularly. Significant RNAi-mediated reduction of endogenous GLUT-1 expression impaired HTLV-1 Env-mediated fusion with HeLa cells but not with U87 cells. We propose a GLUT-1-independent mechanism

  11. The effect of Glut1 and c-myc on prognosis in esophageal squamous cell carcinoma of Kazakh and Han patients.

    Science.gov (United States)

    Zhou, Ya-Xing; Zhou, Ke-Ming; Liu, Qian; Wang, Hui; Wang, Wen; Shi, Yi; Ma, Yu-Qing

    2018-04-09

    Glucose transporter type 1 (Glut1) plays a crucial role in cancer-specific metabolism. We explored the expression of Glut1 and c-myc, the relationship between them and the effect of Glut1, c-myc on prognosis in esophageal squamous cell carcinoma. Immunohistochemistry was used to examine the expression of Glut1 and c-myc. χ 2 test analyzes the relationship between c-myc, Glut1 and pathological parameters. Spearman correlation analyzes the relationship between c-myc and Glut1. Survival analysis was used to investigate the effect of Glut1 and c-myc on prognosis. Glut1 positivity was associated with tumor size (p C-myc positivity was associated with tumor location (p = 0.015), depth of invasion (p = 0.022) and lymph node metastasis (p = 0.035). There was a positive correlation between c-myc and Glut1 (r = 0.321). Patients with Glut1 c-myc co-expression had poorer prognosis. Inhibiting Glut1 c-myc co-expression may improve the prognosis of esophageal squamous cell carcinoma.

  12. Long-Term Chronic Intermittent Hypobaric Hypoxia Induces Glucose Transporter (GLUT4 Translocation Through AMP-Activated Protein Kinase (AMPK in the Soleus Muscle in Lean Rats

    Directory of Open Access Journals (Sweden)

    Patricia Siques

    2018-06-01

    Full Text Available Background: In chronic hypoxia (CH and short-term chronic intermittent hypoxia (CIH exposure, glycemia and insulin levels decrease and insulin sensitivity increases, which can be explained by changes in glucose transport at skeletal muscles involving GLUT1, GLUT4, Akt, and AMPK, as well as GLUT4 translocation to cell membranes. However, during long-term CIH, there is no information regarding whether these changes occur similarly or differently than in other types of hypoxia exposure. This study evaluated the levels of AMPK and Akt and the location of GLUT4 in the soleus muscles of lean rats exposed to long-term CIH, CH, and normoxia (NX and compared the findings.Methods: Thirty male adult rats were randomly assigned to three groups: a NX (760 Torr group (n = 10, a CIH group (2 days hypoxia/2 days NX; n = 10 and a CH group (n = 10. Rats were exposed to hypoxia for 30 days in a hypobaric chamber set at 428 Torr (4,600 m. Feeding (10 g daily and fasting times were accurately controlled. Measurements included food intake (every 4 days, weight, hematocrit, hemoglobin, glycemia, serum insulin (by ELISA, and insulin sensitivity at days 0 and 30. GLUT1, GLUT4, AMPK levels and Akt activation in rat soleus muscles were determined by western blot. GLUT4 translocation was measured with confocal microscopy at day 30.Results: (1 Weight loss and increases in hematocrit and hemoglobin were found in both hypoxic groups (p < 0.05. (2 A moderate decrease in glycemia and plasma insulin was found. (3 Insulin sensitivity was greater in the CIH group (p < 0.05. (4 There were no changes in GLUT1, GLUT4 levels or in Akt activation. (5 The level of activated AMPK was increased only in the CIH group (p < 0.05. (6 Increased GLUT4 translocation to the plasma membrane of soleus muscle cells was observed in the CIH group (p < 0.05.Conclusion: In lean rats experiencing long-term CIH, glycemia and insulin levels decrease and insulin sensitivity increases. Interestingly, there

  13. A steady state analysis indicates that negative feedback regulation of PTP1B by Akt elicits bistability in insulin-stimulated GLUT4 translocation

    Directory of Open Access Journals (Sweden)

    Giri Lopamudra

    2004-08-01

    Full Text Available Abstract Background The phenomenon of switch-like response to graded input signal is the theme involved in various signaling pathways in living systems. Positive feedback loops or double negative feedback loops embedded with nonlinearity exhibit these switch-like bistable responses. Such feedback regulations exist in insulin signaling pathway as well. Methods In the current manuscript, a steady state analysis of the metabolic insulin-signaling pathway is presented. The threshold concentration of insulin required for glucose transporter GLUT4 translocation was studied with variation in system parameters and component concentrations. The dose response curves of GLUT4 translocation at various concentration of insulin obtained by steady state analysis were quantified in-terms of half saturation constant. Results We show that, insulin-stimulated GLUT4 translocation can operate as a bistable switch, which ensures that GLUT4 settles between two discrete, but mutually exclusive stable steady states. The threshold concentration of insulin required for GLUT4 translocation changes with variation in system parameters and component concentrations, thus providing insights into possible pathological conditions. Conclusion A steady state analysis indicates that negative feedback regulation of phosphatase PTP1B by Akt elicits bistability in insulin-stimulated GLUT4 translocation. The threshold concentration of insulin required for GLUT4 translocation and the corresponding bistable response at different system parameters and component concentrations was compared with reported experimental observations on specific defects in regulation of the system.

  14. Effects of high-intensity swimming training on GLUT-4 and glucose transport activity in rat skeletal muscle.

    Science.gov (United States)

    Terada, S; Yokozeki, T; Kawanaka, K; Ogawa, K; Higuchi, M; Ezaki, O; Tabata, I

    2001-06-01

    This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than

  15. Glucose transporter expression in an avian nectarivore: the ruby-throated hummingbird (Archilochus colubris.

    Directory of Open Access Journals (Sweden)

    Kenneth C Welch

    Full Text Available Glucose transporter (GLUT proteins play a key role in the transport of monosaccharides across cellular membranes, and thus, blood sugar regulation and tissue metabolism. Patterns of GLUT expression, including the insulin-responsive GLUT4, have been well characterized in mammals. However, relatively little is known about patterns of GLUT expression in birds with existing data limited to the granivorous or herbivorous chicken, duck and sparrow. The smallest avian taxa, hummingbirds, exhibit some of the highest fasted and fed blood glucose levels and display an unusual ability to switch rapidly and completely between endogenous fat and exogenous sugar to fuel energetically expensive hovering flight. Despite this, nothing is known about the GLUT transporters that enable observed rapid rates of carbohydrate flux. We examined GLUT (GLUT1, 2, 3, & 4 expression in pectoralis, leg muscle, heart, liver, kidney, intestine and brain from both zebra finches (Taeniopygia guttata and ruby-throated hummingbirds (Archilochus colubris. mRNA expression of all four transporters was probed using reverse-transcription PCR (RT-PCR. In addition, GLUT1 and 4 protein expression were assayed by western blot and immunostaining. Patterns of RNA and protein expression of GLUT1-3 in both species agree closely with published reports from other birds and mammals. As in other birds, and unlike in mammals, we did not detect GLUT4. A lack of GLUT4 correlates with hyperglycemia and an uncoupling of exercise intensity and relative oxidation of carbohydrates in hummingbirds. The function of GLUTs present in hummingbird muscle tissue (e.g. GLUT1 and 3 remain undescribed. Thus, further work is necessary to determine if high capillary density, and thus surface area across which cellular-mediated transport of sugars into active tissues (e.g. muscle occurs, rather than taxon-specific differences in GLUT density or kinetics, can account for observed rapid rates of sugar flux into these

  16. L-Cysteine supplementation increases adiponectin synthesis and secretion, and GLUT4 and glucose utilization by upregulating disulfide bond A-like protein expression mediated by MCP-1 inhibition in 3T3-L1 adipocytes exposed to high glucose.

    Science.gov (United States)

    Achari, Arunkumar Elumalai; Jain, Sushil K

    2016-03-01

    Adiponectin is an anti-diabetic and anti-atherogenic adipokine; its plasma levels are decreased in obesity, insulin resistance, and type 2 diabetes. An adiponectin-interacting protein named disulfide bond A-like protein (DsbA-L) plays an important role in the assembly of adiponectin. This study examined the hypothesis that L-cysteine (LC) regulates glucose homeostasis through the DsbA-L upregulation and synthesis and secretion of adiponectin in diabetes. 3T3L1 adipocytes were treated with LC (250 and 500 µM, 2 h) and high glucose (HG, 25 mM, 20 h). Results showed that LC supplementation significantly (p L, adiponectin, and GLUT-4 protein expression and glucose utilization in HG-treated adipocytes. LC supplementation significantly (p L expression and adiponectin levels in 3T3-L1 cells. Treatment with LC prevented the decrease in DsbA-L, adiponectin, and GLUT-4 expression in 3T3L1 adipocyte cells exposed to MCP-1. Thus, this study demonstrates that DsbA-L and adiponectin upregulation mediates the beneficial effects of LC on glucose utilization by inhibiting MCP-1 secretion in adipocytes and provides a novel mechanism by which LC supplementation can improve insulin sensitivity in diabetes.

  17.  The role of glucose transporter 1 (GLUT1 in the diagnosis and therapy of tumors

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    Paweł Jóźwiak

    2012-03-01

    Full Text Available  Malignant cells are known to enhance glucose metabolism, to increase glucose uptake and to inhibit the process of oxidative phosphorylation. Accelerated glycolysis is one of the biochemical characteristics of cancer cells that allow them to compensate the inefficient extraction of energy from glucose in order to continue their uncontrolled growth and proliferation. Upregulation of glucose transport across the plasma membrane is mediated by a family of facilitated glucose transporter proteins named GLUT. Overexpression of GLUTs, especially the hypoxia-responsive GLUT1, has been frequently observed in various human carcinomas. Many studies have reported a correlation between GLUT1 expression level and the grade of tumor aggressiveness, which suggests that GLUT1 expression may be of prognostic significance. Therefore, GLUT1 is a key rate-limiting factor in the transport and glucose metabolism in cancer cells. This paper presents the current state of knowledge on GLUT1 regulation as well as its utility in the diagnosis and therapy of cancers.

  18. Insulin modulates hippocampally-mediated spatial working memory via glucose transporter-4.

    Science.gov (United States)

    Pearson-Leary, J; Jahagirdar, V; Sage, J; McNay, E C

    2018-02-15

    The insulin-regulated glucose transporter, GluT4, is a key molecule in peripheral insulin signaling. Although GluT4 is abundantly expressed in neurons of specific brain regions such as the hippocampus, the functional role of neuronal GluT4 is unclear. Here, we used pharmacological inhibition of GluT4-mediated glucose uptake to determine whether GluT4 mediates insulin-mediated glucose uptake in the hippocampus. Consistent with previous reports, we found that glucose utilization increased in the dorsal hippocampus of male rats during spontaneous alternation (SA), a hippocampally-mediated spatial working memory task. We previously showed that insulin signaling within the hippocampus is required for processing this task, and that administration of exogenous insulin enhances performance. At baseline levels of hippocampal insulin, inhibition of GluT4-mediated glucose uptake did not affect SA performance. However, inhibition of an upstream regulator of GluT4, Akt, did impair SA performance. Conversely, when a memory-enhancing dose of insulin was delivered to the hippocampus prior to SA-testing, inhibition of GluT4-mediated glucose transport prevented cognitive enhancement. These data suggest that baseline hippocampal cognitive processing does not require functional hippocampal GluT4, but that cognitive enhancement by supra-baseline insulin does. Consistent with these findings, we found that in neuronal cell culture, insulin increases glucose utilization in a GluT4-dependent manner. Collectively, these data demonstrate a key role for GluT4 in transducing the procognitive effects of elevated hippocampal insulin. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Exercise-induced increase in glucose transport, GLUT-4, and VAMP-2 in plasma membrane from human muscle

    DEFF Research Database (Denmark)

    Kristiansen, S; Hargreaves, Mark; Richter, Erik

    1996-01-01

    contractions may induce trafficking of GLUT-4-containing vesicles via a mechanism similar to neurotransmitter release. Our results demonstrate for the first time exercise-induced translocation of GLUT-4 and VAMP-2 to the plasma membrane of human muscle and increased sarcolemmal glucose transport.......A major effect of muscle contractions is an increase in sarcolemmal glucose transport. We have used a recently developed technique to produce sarcolemmal giant vesicles from human muscle biopsy samples obtained before and after exercise. Six men exercised for 10 min at 50% maximal O2 uptake (Vo2max...

  20. Pulsatile Hyperglycaemia Induces Vascular Oxidative Stress and GLUT 1 Expression More Potently than Sustained Hyperglycaemia in Rats on High Fat Diet

    DEFF Research Database (Denmark)

    Rakipovski, Gunaj; Lykkesfeldt, Jens; Raun, Kirsten

    2016-01-01

    expression of glucose transporter 1 (GLUT1), gp-91(PHOX) and super oxide dismutase (SOD), while only the PLG group showed increased accumulation of oxidative stress and oxidised low density lipoprotein (oxLDL) in aorta. Conclusion Pulsatile hyperglycaemia induced relatively higher levels of oxidative stress......Introduction Pulsatile hyperglycaemia resulting in oxidative stress may play an important role in the development of macrovascular complications. We investigated the effects of sustained vs. pulsatile hyperglycaemia in insulin resistant rats on markers of oxidative stress, enzyme expression...... and glucose metabolism in liver and aorta. We hypothesized that liver's ability to regulate the glucose homeostasis under varying states of hyperglycaemia may indirectly affect oxidative stress status in aorta despite the amount of glucose challenged with. Methods Animals were infused with sustained high (SHG...

  1. An efficient co-expression and purification system for the complex of Stx4 and C-terminal domain of Synip

    International Nuclear Information System (INIS)

    Tian Wei; Ma Cong; Liu Yingfang; Xu Tao

    2008-01-01

    Synip and Stx4 complex plays a key role in GLUT4 vesicle trafficking and fusion with plasma membrane. The interaction of Synip with Stx4 prevents interaction of VAMP2 located in GLUT4 vesicle with Stx4 in basal state. Insulin induces the dissociation of the Synip and Stx4 complex, and then triggers VAMP2 to interact with Stx4 to form the SNARE complex, thus promoting the vesicle fusion. In this report, we adopt a novel system for co-expression of the Synip and Stx4 by using two common vectors pGEX6p-1 and pET28a(+) to investigate their expression, purification, and interaction. Through this co-expression system, we successfully co-expressed the Synip and Stx4 complex with high yield, and co-purified at an approximate 1:1 molar ratio with high purity (95%). We also demonstrate that the 1-28 residues of Stx4 are dispensable for interaction with Synip using this co-expression system

  2. The invisible teenager: Comic book materiality and the amateur films of Don Glut

    Directory of Open Access Journals (Sweden)

    Matt Yockey

    2014-06-01

    Full Text Available Don Glut, between the ages of 9 and 25, made 41 short amateur films inspired by horror, science fiction, and superhero movies, serials, and comic books. The tactile qualities of comic books as affect-generating objects are instrumental to how Glut confirmed his identity during a time (adolescence in which that identity is particularly unstable. Glut used the popular figure of the teen rebel and his role as a filmmaker in order to negotiate with hegemonic restrictions on his objects of affection, especially comic books.

  3. Photoactivation of GLUT4 translocation promotes glucose uptake via PI3-K/Akt2 signaling in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2014-05-01

    Full Text Available Insulin resistance is a hallmark of the metabolic syndrome and type 2 diabetes. Dysfunction of PI-3K/Akt signaling was involved in insulin resistance. Glucose transporter 4 (GLUT4 is a key factor for glucose uptake in muscle and adipose tissues, which is closely regulated by PI-3K/Akt signaling in response to insulin treatment. Low-power laser irradiation (LPLI has been shown to regulate various physiological processes and induce the synthesis or release of multiple molecules such as growth factors, which (especially red and near infrared light is mainly through the activation of mitochondrial respiratory chain and the initiation of intracellular signaling pathways. Nevertheless, it is unclear whether LPLI could promote glucose uptake through activation of PI-3K/Akt/GLUT4 signaling in 3T3L-1 adipocytes. In this study, we investigated how LPLI promoted glucose uptake through activation of PI-3K/Akt/GLUT4 signaling pathway. Here, we showed that GLUT4 was localized to the Golgi apparatus and translocated from cytoplasm to cytomembrane upon LPLI treatment in 3T3L-1 adipocytes, which enhanced glucose uptake. Moreover, we found that glucose uptake was mediated by the PI3-K/Akt2 signaling, but not Akt1 upon LPLI treatment with Akt isoforms gene silence and PI3-K/Akt inhibitors. Collectively, our results indicate that PI3-K/Akt2/GLUT4 signaling act as the key regulators for improvement of glucose uptake under LPLI treatment in 3T3L-1 adipocytes. More importantly, our findings suggest that activation of PI3-K/Akt2/GLUT4 signaling by LPLI may provide guidance in practical applications for promotion of glucose uptake in insulin-resistant adipose tissue.

  4. Metabolic markers in relation to hypoxia; staining patterns and colocalization of pimonidazole, HIF-1α, CAIX, LDH-5, GLUT-1, MCT1 and MCT4

    International Nuclear Information System (INIS)

    Rademakers, Saskia E; Lok, Jasper; Kogel, Albert J van der; Bussink, Johan; Kaanders, Johannes HAM

    2011-01-01

    The cellular response of malignant tumors to hypoxia is diverse. Several important endogenous metabolic markers are upregulated under hypoxic conditions. We examined the staining patterns and co-expression of HIF-1α, CAIX, LDH-5, GLUT-1, MCT1 and MCT4 with the exogenous hypoxic cell marker pimonidazole and the association of marker expression with clinicopathological characteristics. 20 biopsies of advanced head and neck carcinomas were immunohistochemically stained and analyzed. All patients were given the hypoxia marker pimonidazole intravenously 2 h prior to biopsy taking. The tumor area positive for each marker, the colocalization of the different markers and the distribution of the markers in relation to the blood vessels were assessed by semiautomatic quantitative analysis. MCT1 staining was present in hypoxic (pimonidazole stained) as well as non-hypoxic areas in almost equal amounts. MCT1 expression showed a significant overall correlation (r = 0.75, p < 0.001) and strong spatial relationship with CAIX. LDH-5 showed the strongest correlation with pimonidazole (r = 0.66, p = 0.002). MCT4 and GLUT-1 demonstrated a typical diffusion-limited hypoxic pattern and showed a high degree of colocalization. Both MCT4 and CAIX showed a higher expression in the primary tumor in node positive patients (p = 0.09 both). Colocalization and staining patterns of metabolic and hypoxia-related proteins provides valuable additional information over single protein analyses and can improve the understanding of their functions and environmental influences

  5. Fisetin Suppresses Lipid Accumulation in Mouse Adipocytic 3T3-L1 Cells by Repressing GLUT4-Mediated Glucose Uptake through Inhibition of mTOR-C/EBPα Signaling.

    Science.gov (United States)

    Watanabe, Marina; Hisatake, Mitsuhiro; Fujimori, Ko

    2015-05-27

    3,7,3',4'-Tetrahydroxyflavone (fisetin) is a flavonoid found in vegetables and fruits having broad biological activities. Here the effects of fisetin on adipogenesis and its regulatory mechanism in mouse adipocytic 3T3-L1 cells are studied. Fisetin inhibited the accumulation of intracellular lipids and lowered the expression of adipogenic genes such as peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein (C/EBP) α and fatty acid-binding protein 4 (aP2) during adipogenesis. Moreover, the mRNA levels of genes such as acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase involved in the fatty acid biosynthesis (lipogenesis) were reduced by the treatment with fisetin. The expression level of the glucose transporter 4 (GLUT4) gene was also decreased by fisetin, resulting in down-regulation of glucose uptake. Furthermore, fisetin inhibited the phosphorylation of the mammalian target of rapamycin (mTOR) and that of p70 ribosomal S6 kinase, a target of the mTOR complex, the inhibition of which was followed by a decreased mRNA level of the C/EBPα gene. The results obtained from a chromatin immunoprecipitation assay demonstrated that the ability of C/EBPα to bind to the GLUT4 gene promoter was reduced by the treatment with fisetin, which agreed well with those obtained when 3T3-L1 cells were allowed to differentiate into adipocytes in medium in the presence of rapamycin, an inhibitor for mTOR. These results indicate that fisetin suppressed the accumulation of intracellular lipids by inhibiting GLUT4-mediated glucose uptake through inhibition of the mTOR-C/EBPα signaling in 3T3-L1 cells.

  6. Arsenite stimulated glucose transport in 3T3-L1 adipocytes involves both Glut4 translocation and p38 MAPK activity

    NARCIS (Netherlands)

    Bazuine, Merlijn; Ouwens, D. Margriet; Gomes de Mesquita, Daan S.; Maassen, J. Antonie

    2003-01-01

    The protein-modifying agent arsenite stimulates glucose uptake in 3T3-L1 adipocytes. In the current study we have analysed the signalling pathways that contribute to this response. By subcellular fractionation we observed that arsenite, like insulin, induces translocation of the GLUT1 and GLUT4

  7. Role of vitamin D on the expression of glucose transporters in L6 myotubes

    Directory of Open Access Journals (Sweden)

    Bubblu Tamilselvan

    2013-01-01

    Full Text Available Altered expression of glucose transporters is a major characteristic of diabetes. Vitamin D has evolved widespread interest in the pathogenesis and prevention of diabetes. The present study was designed to investigate the effect of vitamin D in the overall regulation of muscle cell glucose transporter expression. L6 cells were exposed to type 1 and type 2 diabetic conditions and the effect of calcitriol (1,25, dihydroxy cholicalciferol on the expression of glucose transporters was studied by real time polymerase chain reaction (RT-PCR. There was a significant decrease in glucose transporter type 1 (GLUT1, GLUT4, vitamin D receptor (VDR, and IR expression in type 1 and 2 diabetic model compared to control group. Treatment of myoblasts with 10-7 M calcitriol for 24 h showed a significant increase in GLUT1, GLUT4, VDR, and insulin receptor (IR expression. The results indicate a potential antidiabetic function of vitamin D on GLUT1, GLUT4, VDR, and IR by improving receptor gene expression suggesting a role for vitamin D in regulation of expression of the glucose transporters in muscle cells.

  8. Rac1 governs exercise‐stimulated glucose uptake in skeletal muscle through regulation of GLUT4 translocation in mice

    Science.gov (United States)

    Nielsen, Ida L.; Kleinert, Maximilian; Møller, Lisbeth L. V.; Ploug, Thorkil; Schjerling, Peter; Bilan, Philip J.; Klip, Amira; Jensen, Thomas E.; Richter, Erik A.

    2016-01-01

    Key point Exercise increases skeletal muscle energy turnover and one of the important substrates for the working muscle is glucose taken up from the blood.The GTPase Rac1 can be activated by muscle contraction and has been found to be necessary for insulin‐stimulated glucose uptake, although its role in exercise‐stimulated glucose uptake is unknown.We show that Rac1 regulates the translocation of the glucose transporter GLUT4 to the plasma membrane in skeletal muscle during exercise.We find that Rac1 knockout mice display significantly reduced glucose uptake in skeletal muscle during exercise. Abstract Exercise increases skeletal muscle energy turnover and one of the important substrates for the working muscle is glucose taken up from the blood. Despite extensive efforts, the signalling mechanisms vital for glucose uptake during exercise are not yet fully understood, although the GTPase Rac1 is a candidate molecule. The present study investigated the role of Rac1 in muscle glucose uptake and substrate utilization during treadmill exercise in mice in vivo. Exercise‐induced uptake of radiolabelled 2‐deoxyglucose at 65% of maximum running capacity was blocked in soleus muscle and decreased by 80% and 60% in gastrocnemius and tibialis anterior muscles, respectively, in muscle‐specific inducible Rac1 knockout (mKO) mice compared to wild‐type littermates. By developing an assay to quantify endogenous GLUT4 translocation, we observed that GLUT4 content at the sarcolemma in response to exercise was reduced in Rac1 mKO muscle. Our findings implicate Rac1 as a regulatory element critical for controlling glucose uptake during exercise via regulation of GLUT4 translocation. PMID:27061726

  9. The inability of phosphatidylinositol 3-kinase activation to stimulate GLUT4 translocation indicates additional signaling pathways are required for insulin-stimulated glucose uptake.

    Science.gov (United States)

    Isakoff, S J; Taha, C; Rose, E; Marcusohn, J; Klip, A; Skolnik, E Y

    1995-10-24

    Recent experimental evidence has focused attention to the role of two molecules, insulin receptor substrate 1 (IRS-1) and phosphatidylinositol 3-kinase (PI3-kinase), in linking the insulin receptor to glucose uptake; IRS-1 knockout mice are insulin resistant, and pharmacological inhibitors of PI3-kinase block insulin-stimulated glucose uptake. To investigate the role of PI3-kinase and IRS-1 in insulin-stimulated glucose uptake we examined whether stimulation of insulin-sensitive cells with platelet-derived growth factor (PDGF) or with interleukin 4 (IL-4) stimulates glucose uptake; the activated PDGF receptor (PDGFR) directly binds and activates PI3-kinase, whereas the IL-4 receptor (IL-4R) activates PI3-kinase via IRS-1 or the IRS-1-related molecule 4PS. We found that stimulation of 3T3-L1 adipocytes with PDGF resulted in tyrosine phosphorylation of the PDGFR and activation of PI3-kinase in these cells. To examine whether IL-4 stimulates glucose uptake, L6 myoblasts were engineered to overexpress GLUT4 as well as both chains of the IL-4R (L6/IL-4R/GLUT4); when these L6/IL-4R/GLUT4 myoblasts were stimulated with IL-4, IRS-1 became tyrosine phosphorylated and associated with PI3-kinase. Although PDGF and IL-4 can activate PI3-kinase in the respective cell lines, they do not possess insulin's ability to stimulate glucose uptake and GLUT4 translocation to the plasma membrane. These findings indicate that activation of PI3-kinase is not sufficient to stimulate GLUT4 translocation to the plasma membrane. We postulate that activation of a second signaling pathway by insulin, distinct from PI3-kinase, is necessary for the stimulation of glucose uptake in insulin-sensitive cells.

  10. A High Fat Diet During Pregnancy and Lactation Induces Cardiac and Renal Abnormalities in GLUT4 +/- Male Mice

    Directory of Open Access Journals (Sweden)

    Michael Kruse

    2017-07-01

    Full Text Available Background/Aims: Altered nutrients during the in utero (IU and/or lactation (L period predispose offspring to cardio-renal diseases in adulthood. This study investigates the effect of a high fat diet (HFD fed to female mice during IU/L on gene expression patterns associated with heart and kidney failure and hypertension in male offspring. Methods: Female wild type (WT mice were fed either a HFD or control chow (C prior to mating with males with a genetic heterozygous deletion of GLUT4 (G4+/-, a model of peripheral insulin resistance and hypertension and throughout IU/L. After weaning male offspring were placed on a standard rodent chow until 24 weeks of age. Results: All offspring exposed to a maternal HFD showed increased heart and kidney weight and reduced cardiac insulin responsiveness. G4+/- offspring on a HFD displayed early hypertension associated with increased renal gene expression of renin and the AT1- receptors compared to G4+/- on a C diet. This group showed decreased cardiac expression of key genes involved in fatty acid oxidation compared to WT on a C diet. Conclusions: These results indicate an interaction between a HFD diet and genotype during early life development that can enhance susceptibility to cardio-renal diseases later in life.

  11. XbaI GLUT1 Gene Polymorphism and the Risk of Type 2 Diabetes with Nephropathy

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    Ioannis Stefanidis

    2009-01-01

    Full Text Available Altered expression of the facilitated glucose transporter GLUT1 affects pathways implicated in the pathogenesis of diabetic nephropathy. There is indication that variation of GLUT1 gene (SLC2A1 contributes to development of microangiopathy in diabetes mellitus type 2 (DM patients. A genetic association study involving Caucasians was carried out to investigate the role of XbαI polymorphism in the GLUT1 gene in diabetic nephropathy (DN. Study population (n = 240 consisted of 148 unrelated patients with DM (92 cases with diabetic nephropathy (DN, and of 92 matched healthy control subjects. Diabetic nephropathy was defined as persistent albuminuria (> 300 mg/24 h and/or renal failure, in the absence of non-diabetes induced renal disease. The analysis showed that the risk of developing DM and DN in XbaI(− carriers, when healthy individuals were considered as controls, was two-fold: odds ratio (OR 2.08 [95% confidence interval (1.14–3.79]. However, there was no evidence of association between XbaI(− and DN when patients with DM and without DN were considered as controls: OR = 1.12 (0.55–2.26. Thus, the GLUT1 XbaI(− allele is associated with DM, and possibly with a more severe form of the disease that can lead to development of DN.

  12. Adolescents with clinical type 1 diabetes display reduced red blood cell glucose transporter isoform 1 (GLUT1).

    Science.gov (United States)

    Garg, Meena; Thamotharan, Manikkavasagar; Becker, Dorothy J; Devaskar, Sherin U

    2014-11-01

    Type 1 diabetic (T1D) adolescent children on insulin therapy suffer episodes of both hyper- and hypoglycemic episodes. Glucose transporter isoform GLUT1 expressed in blood-brain barrier (BBB) and red blood cells (RBC) compensates for perturbed circulating glucose toward protecting the supply to brain and RBCs. We hypothesized that RBC-GLUT1 concentration, as a surrogate for BBB-GLUT1, is altered in T1D children. To test this hypothesis, we measured RBC-GLUT1 by enzyme-linked immunosorbent assay (ELISA) in T1D children (n = 72; mean age 15.3 ± 0.2 yr) and control children (CON; n = 11; mean age 15.6 ± 0.9 yr) after 12 h of euglycemia and during a hyperinsulinemic-hypoglycemic clamp with a nadir blood glucose of ~3.3 mmol/L for 90 min (clamp I) or ~3 mmol/L for 45 min (clamp II). Reduced baseline RBC-GLUT1 was observed in T1D (2.4 ± 0.17 ng/ng membrane protein); vs. CON (4.2 ± 0.61 ng/ng protein) (p < 0.0001). Additionally, baseline RBC-GLUT1 in T1D negatively correlated with hemoglobin A1c (HbA1c) (R = -0.23, p < 0.05) but not in CON (R = 0.06, p < 0.9). Acute decline in serum glucose to 3.3 mmol/L (90 min) or 3 mmol/L (45 min) did not change baseline RBC-GLUT1 in T1D or CON children. We conclude that reduced RBC-GLUT1 encountered in T1D, with no ability to compensate by increasing during acute hypoglycemia over the durations examined, may demonstrate a vulnerability of impaired RBC glucose transport (serving as a surrogate for BBB), especially in those with the worst control. We speculate that this may contribute to the perturbed cognition seen in T1D adolescents. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Signal transduction meets vesicle traffic: the software and hardware of GLUT4 translocation.

    Science.gov (United States)

    Klip, Amira; Sun, Yi; Chiu, Tim Ting; Foley, Kevin P

    2014-05-15

    Skeletal muscle is the major tissue disposing of dietary glucose, a function regulated by insulin-elicited signals that impart mobilization of GLUT4 glucose transporters to the plasma membrane. This phenomenon, also central to adipocyte biology, has been the subject of intense and productive research for decades. We focus on muscle cell studies scrutinizing insulin signals and vesicle traffic in a spatiotemporal manner. Using the analogy of an integrated circuit to approach the intersection between signal transduction and vesicle mobilization, we identify signaling relays ("software") that engage structural/mechanical elements ("hardware") to enact the rapid mobilization and incorporation of GLUT4 into the cell surface. We emphasize how insulin signal transduction switches from tyrosine through lipid and serine phosphorylation down to activation of small G proteins of the Rab and Rho families, describe key negative regulation step of Rab GTPases through the GTPase-activating protein activity of the Akt substrate of 160 kDa (AS160), and focus on the mechanical effectors engaged by Rabs 8A and 10 (the molecular motor myosin Va), and the Rho GTPase Rac1 (actin filament branching and severing through Arp2/3 and cofilin). Finally, we illustrate how actin filaments interact with myosin 1c and α-Actinin4 to promote vesicle tethering as preamble to fusion with the membrane. Copyright © 2014 the American Physiological Society.

  14. Evaluating the Efficacy of GLUT Inhibitors Using a Seahorse Extracellular Flux Analyzer.

    Science.gov (United States)

    Wei, Changyong; Heitmeier, Monique; Hruz, Paul W; Shanmugam, Mala

    2018-01-01

    Glucose is metabolized through anaerobic glycolysis and aerobic oxidative phosphorylation (OXPHOS). Perturbing glucose uptake and its subsequent metabolism can alter both glycolytic and OXPHOS pathways and consequently lactate and/or oxygen consumption. Production and secretion of lactate, as a consequence of glycolysis, leads to acidification of the extracellular medium. Molecular oxygen is the final electron acceptor in the electron transport chain, facilitating oxidative phosphorylation of ADP to ATP. The alterations in extracellular acidification and/or oxygen consumption can thus be used as indirect readouts of glucose metabolism and assessing the impact of inhibiting glucose transport through specific glucose transporters (GLUTs). The Seahorse bioenergetics analyzer can measure both the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). The proposed methodology affords a robust, high-throughput method to screen for GLUT inhibition in cells engineered to express specific GLUTs, providing live cell read-outs upon GLUT inhibition.

  15. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...... were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before...... the marathon and decreased to 148 +/- 39 mmol/kg dry weight immediately afterward. Despite a carbohydrate-rich diet (containing at least 7 g carbohydrate.kg body mass-1.day-1), the muscle glycogen concentration remained 30% lower than before-race values 2 days after the race, whereas it had returned to before...

  16. Novel Roles for the Insulin-Regulated Glucose Transporter-4 in Hippocampally Dependent Memory.

    Science.gov (United States)

    Pearson-Leary, Jiah; McNay, Ewan C

    2016-11-23

    The insulin-regulated glucose transporter-4 (GluT4) is critical for insulin- and contractile-mediated glucose uptake in skeletal muscle. GluT4 is also expressed in some hippocampal neurons, but its functional role in the brain is unclear. Several established molecular modulators of memory processing regulate hippocampal GluT4 trafficking and hippocampal memory formation is limited by both glucose metabolism and insulin signaling. Therefore, we hypothesized that hippocampal GluT4 might be involved in memory processes. Here, we show that, in male rats, hippocampal GluT4 translocates to the plasma membrane after memory training and that acute, selective intrahippocampal inhibition of GluT4-mediated glucose transport impaired memory acquisition, but not memory retrieval. Other studies have shown that prolonged systemic GluT4 blockade causes insulin resistance. Unexpectedly, we found that prolonged hippocampal blockade of glucose transport through GluT4-upregulated markers of hippocampal insulin signaling prevented task-associated depletion of hippocampal glucose and enhanced both working and short-term memory while also impairing long-term memory. These effects were accompanied by increased expression of hippocampal AMPA GluR1 subunits and the neuronal GluT3, but decreased expression of hippocampal brain-derived neurotrophic factor, consistent with impaired ability to form long-term memories. Our findings are the first to show the cognitive impact of brain GluT4 modulation. They identify GluT4 as a key regulator of hippocampal memory processing and also suggest differential regulation of GluT4 in the hippocampus from that in peripheral tissues. The role of insulin-regulated glucose transporter-4 (GluT4) in the brain is unclear. In the current study, we demonstrate that GluT4 is a critical component of hippocampal memory processes. Memory training increased hippocampal GluT4 translocation and memory acquisition was impaired by GluT4 blockade. Unexpectedly, whereas long

  17. Inhibition of Glucose Transport by Tomatoside A, a Tomato Seed Steroidal Saponin, through the Suppression of GLUT2 Expression in Caco-2 Cells.

    Science.gov (United States)

    Li, Baorui; Terazono, Yusuke; Hirasaki, Naoto; Tatemichi, Yuki; Kinoshita, Emiko; Obata, Akio; Matsui, Toshiro

    2018-02-14

    We investigated whether tomatoside A (5α-furostane-3β,22,26-triol-3-[O-β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl (1→4)-β-d-galactopyranoside] 26-O-β-d-glucopyranoside), a tomato seed saponin, may play a role in the regulation of intestinal glucose transport in human intestinal Caco-2 cells. Tomatoside A could not penetrate through Caco-2 cell monolayers, as observed in the transport experiments using liquid chromatography-mass spectrometry. The treatment of cells with 10 μM tomatoside A for 3 h resulted in a 46.0% reduction in glucose transport as compared to untreated cells. Western blotting analyses revealed that tomatoside A significantly (p transporter 2 (GLUT2) in Caco-2 cells, while no change in the expression of sodium-dependent glucose transporter 1 was observed. In glucose transport experiments, the reduced glucose transport by tomatoside A was ameliorated by a protein kinase C (PKC) inhibitor and a multidrug resistance-associated protein 2 (MRP2) inhibitor. The tomatoside A-induced reduction in glucose transport was restored in cells treated with apical sodium-dependent bile acid transporter (ASBT) siRNA or an ASBT antagonist. These findings demonstrated for the first time that the nontransportable tomato seed steroidal saponin, tomatoside A, suppressed GLUT2 expression via PKC signaling pathway during the ASBT-influx/MRP2-efflux process in Caco-2 cells.

  18. FGT-1 is a mammalian GLUT2-like facilitative glucose transporter in Caenorhabditis elegans whose malfunction induces fat accumulation in intestinal cells.

    Directory of Open Access Journals (Sweden)

    Shun Kitaoka

    Full Text Available Caenorhabditis elegans (C. elegans is an attractive animal model for biological and biomedical research because it permits relatively easy genetic dissection of cellular pathways, including insulin/IGF-like signaling (IIS, that are conserved in mammalian cells. To explore C. elegans as a model system to study the regulation of the facilitative glucose transporter (GLUT, we have characterized the GLUT gene homologues in C. elegans: fgt-1, R09B5.11, C35A11.4, F53H8.3, F48E3.2, F13B12.2, Y61A9LA.1, K08F9.1 and Y37A1A.3. The exogenous expression of these gene products in Xenopus oocytes showed transport activity to unmetabolized glucose analogue 2-deoxy-D-glucose only in FGT-1. The FGT-1-mediated transport activity was inhibited by the specific GLUT inhibitor phloretin and exhibited a Michaelis constant (Km of 2.8 mM. Mannose, galactose, and fructose were able to inhibit FGT-1-mediated 2-deoxy-D-glucose uptake (P < 0.01, indicating that FGT-1 is also able to transport these hexose sugars. A GFP fusion protein of FGT-1 was observed only on the basolateral membrane of digestive tract epithelia in C. elegans, but not in other tissues. FGT-1::eGFP expression was observed from early embryonic stages. The knockdown or mutation of fgt-1 resulted in increased fat staining in both wild-type and daf-2 (mammalian insulin receptor homologue mutant animals. Other common phenotypes of IIS mutant animals, including dauer formation and brood size reduction, were not affected by fgt-1 knockdown in wild-type or daf-2 mutants. Our results indicated that in C. elegans, FGT-1 is mainly a mammalian GLUT2-like intestinal glucose transporter and is involved in lipid metabolism.

  19. Stereospermum tetragonam as an antidiabetic agent by activating PPARγ and GLUT4

    Directory of Open Access Journals (Sweden)

    Bino Kingsley

    2014-06-01

    Full Text Available Present study evaluates the anti-diabetic activity of S. tetragonam LC-MSMS experiments showed the presence of two novel molecules C1 and C2, which were further taken for in silico study against PPARγ. Cell culture studies with A431 cells in the presence of crude aqueous extract showed the elevated level of PPARγ and GLUT4 and also confirmed using in silico studies. Thus, the present study proves the mecode of action of S. tetragonam as an antidiabetic drug.

  20. Glut2-dependent glucose-sensing controls thermoregulation by enhancing the leptin sensitivity of NPY and POMC neurons.

    Science.gov (United States)

    Mounien, Lourdes; Marty, Nell; Tarussio, David; Metref, Salima; Genoux, David; Preitner, Frédéric; Foretz, Marc; Thorens, Bernard

    2010-06-01

    The physiological contribution of glucose in thermoregulation is not completely established nor whether this control may involve a regulation of the melanocortin pathway. Here, we assessed thermoregulation and leptin sensitivity of hypothalamic arcuate neurons in mice with inactivation of glucose transporter type 2 (Glut2)-dependent glucose sensing. Mice with inactivation of Glut2-dependent glucose sensors are cold intolerant and show increased susceptibility to food deprivation-induced torpor and abnormal hypothermic response to intracerebroventricular administration of 2-deoxy-d-glucose compared to control mice. This is associated with a defect in regulated expression of brown adipose tissue uncoupling protein I and iodothyronine deiodinase II and with a decreased leptin sensitivity of neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons, as observed during the unfed-to-refed transition or following i.p. leptin injection. Sites of central Glut-2 expression were identified by a genetic tagging approach and revealed that glucose-sensitive neurons were present in the lateral hypothalamus, the dorsal vagal complex, and the basal medulla but not in the arcuate nucleus. NPY and POMC neurons were, however, connected to nerve terminals from Glut2-expressing neurons. Thus, our data suggest that glucose controls thermoregulation and the leptin sensitivity of NPY and POMC neurons through activation of Glut2-dependent glucose-sensing neurons located outside of the arcuate nucleus.

  1. Molecular Tools for Facilitative Carbohydrate Transporters (Gluts).

    Science.gov (United States)

    Tanasova, Marina; Fedie, Joseph R

    2017-09-19

    Facilitative carbohydrate transporters-Gluts-have received wide attention over decades due to their essential role in nutrient uptake and links with various metabolic disorders, including diabetes, obesity, and cancer. Endeavors directed towards understanding the mechanisms of Glut-mediated nutrient uptake have resulted in a multidisciplinary research field spanning protein chemistry, chemical biology, organic synthesis, crystallography, and biomolecular modeling. Gluts became attractive targets for cancer research and medicinal chemistry, leading to the development of new approaches to cancer diagnostics and providing avenues for cancer-targeting therapeutics. In this review, the current state of knowledge of the molecular interactions behind Glut-mediated sugar uptake, Glut-targeting probes, therapeutics, and inhibitors are discussed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Near-critical GLUT1 and Neurodegeneration.

    Science.gov (United States)

    Barros, L Felipe; San Martín, Alejandro; Ruminot, Ivan; Sandoval, Pamela Y; Fernández-Moncada, Ignacio; Baeza-Lehnert, Felipe; Arce-Molina, Robinson; Contreras-Baeza, Yasna; Cortés-Molina, Francisca; Galaz, Alex; Alegría, Karin

    2017-11-01

    Recent articles have drawn renewed attention to the housekeeping glucose transporter GLUT1 and its possible involvement in neurodegenerative diseases. Here we provide an updated analysis of brain glucose transport and the cellular mechanisms involved in its acute modulation during synaptic activity. We discuss how the architecture of the blood-brain barrier and the low concentration of glucose within neurons combine to make endothelial/glial GLUT1 the master controller of neuronal glucose utilization, while the regulatory role of the neuronal glucose transporter GLUT3 emerges as secondary. The near-critical condition of glucose dynamics in the brain suggests that subtle deficits in GLUT1 function or its activity-dependent control by neurons may contribute to neurodegeneration. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Antioxidant and glucose metabolizing potential of edible insect, Brachytrupes orientalis via modulating Nrf2/AMPK/GLUT4 signaling pathway.

    Science.gov (United States)

    Dutta, Prachurjya; Dey, Tapan; Dihingia, Anjum; Manna, Prasenjit; Kalita, Jatin

    2017-11-01

    Brachytrupes orientalis (Gryllidae) is a common edible insect species eaten by the different tribes of North East India. This study investigated the potentiality of Brachytrupes orientalis extracts in different solvent hydro-alcoholic (AEBO), hexane (HEBO) and ethyl acetate (EEBO) on glucose utilization and cell viability in high glucose (HG) treated myotubes. It has been observed that AEBO supplementation significantly increased the glucose utilization against HG exposure; however, treatment HEBO and EEBO have no significant effect. AEBO also increased the intercellular glucose-6-phosphate level and the protein expression of both phospho-AMPK and GLUT4 in HG treated myotubes in a dose dependent manner. Furthermore, supplementation with AEBO decreased the intercellular ROS production, lipid peroxidation, and up-regulated the protein expression of Nrf2 and GST. Chromatography and Spectroscopic analyses of AEBO also suggest that Ursolic acid may be one of the bioactive principles with rich potassium, sodium, calcium and magnesium content. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Glucose transporter expression differs between bovine monocyte and macrophage subsets and is influenced by milk production.

    Science.gov (United States)

    Eger, M; Hussen, J; Koy, M; Dänicke, S; Schuberth, H-J; Breves, G

    2016-03-01

    The peripartal period of dairy cows is characterized by negative energy balance and higher incidences of infectious diseases such as mastitis or metritis. With the onset of lactation, milk production is prioritized and large amounts of glucose are transported into the mammary gland. Decreased overall energy availability might impair the function of monocytes acting as key innate immune cells, which give rise to macrophages and dendritic cells and link innate and adaptive immunity. Information on glucose requirements of bovine immune cells is rare. Therefore, this study aims to evaluate glucose transporter expression of the 3 bovine monocyte subsets (classical, intermediate, and nonclassical monocytes) and monocyte-derived macrophages and to identify influences of the peripartal period. Blood samples were either collected from nonpregnant healthy cows or from 16 peripartal German Holstein cows at d -14, +7, and +21 relative to parturition. Quantitative real-time PCR was applied to determine mRNA expression of glucose transporters (GLUT) 1, GLUT3, and GLUT4 in monocyte subsets and monocyte-derived macrophages. The low GLUT1 and GLUT3 expression in nonclassical monocytes was unaltered during differentiation into macrophages, whereas in classical and intermediate monocytes GLUT expression was downregulated. Alternatively activated M2 macrophages consumed more glucose compared with classically activated M1 macrophages. The GLUT4 mRNA was only detectable in unstimulated macrophages. Neither monocytes nor macrophages were insulin responsive. In the peripartum period, monocyte GLUT1 and GLUT3 expression and the GLUT3/GLUT1 ratio were negatively correlated with lactose production. The high-affinity GLUT3 transporter appears to be the predominant glucose transporter on bovine monocytes and macrophages, especially in the peripartal period when blood glucose levels decline. Glucose transporter expression in monocytes is downregulated as a function of lactose production, which

  5. A novel PTP1B inhibitor extracted from Ganoderma lucidum ameliorates insulin resistance by regulating IRS1-GLUT4 cascades in the insulin signaling pathway.

    Science.gov (United States)

    Yang, Zhou; Wu, Fan; He, Yanming; Zhang, Qiang; Zhang, Yuan; Zhou, Guangrong; Yang, Hongjie; Zhou, Ping

    2018-01-24

    Insulin resistance caused by the overexpression of protein tyrosine phosphatase 1 B (PTP1B) as well as the dephosphorylation of its target is one of the main causes of type 2 diabetes (T2D). A newly discovered proteoglycan, Fudan-Yueyang Ganoderma lucidum (FYGL) extracted from Ganoderma lucidum, was first reported to be capable of competitively inhibiting PTP1B activity in vitro in our previous work. In the present study, we sought to reveal the mechanism of PTP1B inhibition by FYGL at the animal and cellular levels. We found that FYGL can decrease blood glucose, reduce body weight and ameliorate insulin resistance in ob/ob mice. Decrease of PTP1B expression and increase of the phosphorylation of PTP1B targets in the insulin signaling pathway of skeletal muscles were observed. In order to clearly reveal the underlying mechanism of the hypoglycemic effect caused by FYGL, we further investigated the effects of FYGL on the PTP1B-involved insulin signaling pathway in rat myoblast L6 cells. We demonstrated that FYGL had excellent cell permeability by using a confocal laser scanning microscope and a flow cytometer. We found that FYGL had a positive effect on insulin-stimulated glucose uptake by using the 2-deoxyglucose (2-DG) method. FYGL could inhibit PTP1B expression at the mRNA level, phosphorylating insulin receptor substrate-1 (IRS1), as well as activating phosphatidylinositol-3 kinase (PI3K) and protein kinase B (Akt). Finally, FYGL increased the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and consequently up-regulated the expression of glucose transporter type 4 (GLUT4), promoting GLUT4 transportation to the plasma membrane in PTP1B-transfected L6 cells. Our study provides theoretical evidence for FYGL to be potentially used in T2D management.

  6. GLUT2 in pancreatic islets: crucial target molecule in diabetes induced with multiple low doses of streptozotocin in mice.

    Science.gov (United States)

    Wang, Z; Gleichmann, H

    1998-01-01

    In mice, diabetes can be induced by multiple low doses of streptozotocin (MLD-STZ), i.e., 40 mg/kg body wt on each of 5 consecutive days. In this model, diabetes develops only when STZ induces both beta-cell toxicity and T-cell-dependent immune reactions. The target molecule(s) of MLD-STZ-induced beta-cell toxicity are not known, however. In this study, we report that GLUT2 is a target molecule for MLD-STZ toxicity. Ex vivo, a gradual decrement of both GLUT2 protein and mRNA expression was found in pancreatic islets isolated from MLD-STZ-treated C57BL/6 male mice, whereas mRNA expression of beta-actin, glucokinase, and proinsulin remained unaffected. Significant reduction of both GLUT2 protein and mRNA expression was first noted 1 day after the third STZ injection, clearly preceding the onset of hyperglycemia. The extent of reduction increased with the number of STZ injections administered and increased over time, after the last, i.e., fifth, STZ injection. The STZ-induced reduction of GLUT2 protein and mRNA was not due to an essential loss of beta-cells, because ex vivo, not only the total RNA yield and protein content in isolated islets, but also proinsulin mRNA expression, failed to differ significantly in the differently treated groups. Furthermore, islets isolated from MLD-STZ-treated donors responded to the nonglucose secretagogue arginine in a pattern similar to that of solvent-treated donors. Interestingly, the MLD-STZ-induced reduction of both GLUT2 protein and mRNA was prevented by preinjecting mice with 5-thio-D-glucose before each STZ injection. Apparently, GLUT2 is a crucial target molecule of MLD-STZ toxicity, and this toxicity seems to precede the immune reactions against beta-cells.

  7. Genistein induces estrogen-like effects in ovariectomized rats but fails to increase cardiac GLUT4 and oxidative stress.

    Science.gov (United States)

    Al-Nakkash, Layla; Markus, Brandon; Batia, Lyn; Prozialeck, Walter C; Broderick, Tom L

    2010-12-01

    This study aimed to determine whether a 2-week genistein treatment induced estrogen-like effects in ovariectomized (OVX) Sprague-Dawley rats, after 2 weeks of subcutaneous genistein injections (250 mg/kg of body weight/day). Uterine weight, uterine-to-body weight ratio, femur weight, and femur-to-body weight ratio were all significantly increased with genistein in OVX rats. Body weight was significantly decreased with genistein in OVX rats. Genistein had no effect on the weights of heart, heart-to-body ratio, and fat pad but significantly decreased heart rate and pulse pressure. Genistein had no effect on cardiac GLUT4 protein, oxidative stress, plasma glucose, nonesterified fatty acids, or low-density lipoprotein levels; however, plasma insulin levels were significantly increased. Our results show that a 2-week genistein treatment produced favorable estrogen-like effects on some physical and physiological characteristics in OVX rats. However, based on our experimental conditions, the effects of genistein were not associated with changes in cardiac GLUT4 or oxidative stress.

  8. Chronic intermittent hypoxia from pedo-stage decreases glucose transporter 4 expression in adipose tissue and causes insulin resistance.

    Science.gov (United States)

    Chen, Lin; Cao, Zhao-long; Han, Fang; Gao, Zhan-cheng; He, Quan-ying

    2010-02-20

    The persistence of sleep disordered breathing (SDB) symptoms after tonsil and/or adenoid (T&A) surgery are common in children with obstructive sleep apnea (OSA). We tested the hypothesis that disturbances of glucose transporters (GLUTs) in intraabdominal adipose tissue caused by chronic intermittent hypoxia (CIH) from the pedo-period could facilitate the appearance of periphery insulin resistance in Sprague-Dawley (SD) rats. We tested the hypothesis that the changes of GLUTs in adipose tissue may be one of the reasons for persistent SDB among clinical OSA children after T&A surgery. Thirty 21-day-old SD rats were randomly divided into a CIH group, a chronic continuous hypoxia (CCH) group, and a normal oxygen group (control group) and exposed for 40 days. The changes of weight, fasting blood glucose and fasting blood insulin levels were measured. Hyperinsulinemic-euglycemic clamp techniques were used to measure insulin resistance in each animal. Real-time quantitative PCR and Western blotting were used to measure GLUT mRNA and proteins in intraabdominal adipose tissue. Additional intraabdomial white adipose tissue (WAT) was also processed into paraffin sections and directly observed for GLUTs1-4 expression. When compared with control group, CIH increased blood fasting insulin levels, (245.07 +/- 53.89) pg/ml vs. (168.63 +/- 38.70) pg/ml, P = 0.038, and decreased the mean glucose infusion rate (GIR), (7.25 +/- 1.29) mg x kg(-1) x min(-1) vs. (13.34 +/- 1.54) mg x kg(-1) x min(-1), P < 0.001. GLUT-4 mRNA and protein expression was significantly reduced after CIH compared with CCH or normal oxygen rats, 0.002 +/- 0.002 vs. 0.039 +/- 0.009, P < 0.001; 0.642 +/- 0.073 vs. 1.000 +/- 0.103, P = 0.035. CIH in young rats could induce insulin resistance via adverse effects on glycometabolism. These findings emphasize the importance of early detection and treatment of insulin insensitivity in obese childhood OSA.

  9. Refractory absence epilepsy associated with GLUT-1 deficiency syndrome.

    LENUS (Irish Health Repository)

    Byrne, Susan

    2011-05-01

    GLUT-1 deficiency syndrome (GLUT-1 DS) is a disorder of cerebral glucose transport associated with early infantile epilepsy and microcephaly. We report two boys who presented with refractory absence epilepsy associated with hypoglycorrhachia, both of whom have genetically confirmed GLUT-1 DS. We propose that these children serve to expand the phenotype of GLUT-1 DS and suggest that this condition should be considered as a cause of refractory absence seizures in childhood.

  10. Testicular regulation of neuronal glucose and monocarboxylate transporter gene expression profiles in CNS metabolic sensing sites during acute and recurrent insulin-induced hypoglycemia.

    Science.gov (United States)

    Vavaiya, Kamlesh V; Paranjape, Sachin A; Briski, Karen P

    2007-01-01

    Recurrent insulin-induced hypoglycemia (RIIH) impairs glucose counter-regulatory function in male humans and rodents and, in the latter, diminishes neuronal activation in CNS structures that monitor metabolic homeostasis, including the lateral hypothalamic area (LHA) and dorsal vagal complex (DVC). We investigated whether habituated neuronal reactivity in CNS sensing sites to hypoglycemia is correlated with modified monocarboxylate and/or glucose uptake by using quantitative real-time RT-PCR to analyze neuronal monocarboxylate transporter (MCT2) and glucose transporter variant (GLUT and GLUT4) gene expression profiles in the microdissected LHA, ventromedial nucleus hypothalamus (VMH), and DVC after one or multiple insulin injections. Because orchidectomy (ORDX) maintains uniform glycemic responses to RIIH in male rats, we also examined whether regional gene response patterns are testes dependent. In the intact male rat DVC, MCT2, GLUT3, and GLUT4 gene expression was not altered by acute hypoglycemia but was enhanced by RIIH. MCT2 and GLUT3 mRNA levels in the ORDX rat DVC did not differ among groups, but GLUT4 transcripts were progressively increased by acute and recurrent hypoglycemia. Precedent hypoglycemia decreased or increased basal MCT2 and GLUT4 gene expression, respectively, in the intact rat LHA; LHA GLUT3 transcription was augmented by RIIH in intact rats only. Acute hypoglycemia suppressed MCT2, GLUT3, and GLUT4 gene expression in the intact rat VMH, a response that was abolished by RIIH. In ORDX rats, VMH gene transcript levels were unchanged in response to one dose of insulin but were selectively diminished during RIIH. These data demonstrate site-specific, testes-dependent effects of acute and recurrent hypoglycemia on neuronal metabolic substrate transporter gene expression in characterized rat brain metabolic sensing loci and emphasize the need to assess the impact of potential alterations in glucose and lactate uptake during RIIH on general and

  11. Sex-Specific Life Course Changes in the Neuro-Metabolic Phenotype of Glut3 Null Heterozygous Mice: Ketogenic Diet Ameliorates Electroencephalographic Seizures and Improves Sociability.

    Science.gov (United States)

    Dai, Yun; Zhao, Yuanzi; Tomi, Masatoshi; Shin, Bo-Chul; Thamotharan, Shanthie; Mazarati, Andrey; Sankar, Raman; Wang, Elizabeth A; Cepeda, Carlos; Levine, Michael S; Zhang, Jingjing; Frew, Andrew; Alger, Jeffry R; Clark, Peter M; Sondhi, Monica; Kositamongkol, Sudatip; Leibovitch, Leah; Devaskar, Sherin U

    2017-04-01

    We tested the hypothesis that exposure of glut3+/- mice to a ketogenic diet ameliorates autism-like features, which include aberrant behavior and electrographic seizures. We first investigated the life course sex-specific changes in basal plasma-cerebrospinal fluid (CSF)-brain metabolic profile, brain glucose transport/uptake, glucose and monocarboxylate transporter proteins, and adenosine triphosphate (ATP) in the presence or absence of systemic insulin administration. Glut3+/- male but not female mice (5 months of age) displayed reduced CSF glucose/lactate concentrations with no change in brain Glut1, Mct2, glucose uptake or ATP. Exogenous insulin-induced hypoglycemia increased brain glucose uptake in glut3+/- males alone. Higher plasma-CSF ketones (β-hydroxybutyrate) and lower brain Glut3 in females vs males proved protective in the former while enhancing vulnerability in the latter. As a consequence, increased synaptic proteins (neuroligin4 and SAPAP1) with spontaneous excitatory postsynaptic activity subsequently reduced hippocampal glucose content and increased brain amyloid β1-40 deposition in an age-dependent manner in glut3+/- males but not females (4 to 24 months of age). We then explored the protective effect of a ketogenic diet on ultrasonic vocalization, sociability, spatial learning and memory, and electroencephalogram seizures in male mice (7 days to 6 to 8 months of age) alone. A ketogenic diet partially restored sociability without affecting perturbed vocalization, spatial learning and memory, and reduced seizure events. We conclude that (1) sex-specific and age-dependent perturbations underlie the phenotype of glut3+/- mice, and (2) a ketogenic diet ameliorates seizures caused by increased cortical excitation and improves sociability, but fails to rescue vocalization and cognitive deficits in glut3+/- male mice. Copyright © 2017 Endocrine Society.

  12. Effects of octacosanol extracted from rice bran on blood hormone levels and gene expressions of glucose transporter protein-4 and adenosine monophosphate protein kinase in weaning piglets

    Directory of Open Access Journals (Sweden)

    Lei Long

    2015-12-01

    Full Text Available The object of this study was to explore the regulatory mechanism of octacosanol to the body of animals and the effects of octacosanol on blood hormone levels and gene expressions of glucose transporter protein (GLUT-4 and adenosine monophosphate protein kinase (AMPK in liver and muscle tissue of weaning piglets. A total of 105 crossbred piglets ([Yorkshire × Landrace] × Duroc with an initial BW of 5.70 ± 1.41 kg (21 d of age were used in a 6-wk trial to evaluate the effects of octacosanol and tiamulin supplementation on contents of triiodothyronine (T3, thyroxine (T4, growth hormone (GH, glucagon (GU and adrenaline (AD in blood and gene expressions of GLUT-4 and AMPK in liver and muscle. Piglets were randomly distributed into 3 dietary treatments on the basis of BW and sex. Each treatment had 7 replicate pens with 5 piglets per pen. Treatments were as followed: control group, tiamulin group and octacosanol group. The results showed that compared with control group and tiamulin group, octacosanol greatly promoted the secretion of T3, GH, GU and AD (P  0.05. Results of the present study has confirmed that octacosanol affects energy metabolism of body by regulating secretion of blood hormones and related gene expression in tissue of weaning piglets, which can reduce stress response and has an impact on performance.

  13. An increase in immature β-cells lacking Glut2 precedes the expansion of β-cell mass in the pregnant mouse.

    Directory of Open Access Journals (Sweden)

    Christine A Beamish

    Full Text Available A compensatory increase in β-cell mass occurs during pregnancy to counter the associated insulin resistance, and a failure in adaptation is thought to contribute to gestational diabetes. Insulin-expressing but glucose-transporter-2-low (Ins+Glut2LO progenitor cells are present in mouse and human pancreas, being predominantly located in extra-islet β-cell clusters, and contribute to the regeneration of the endocrine pancreas following induced ablation. We therefore sought to investigate the contribution of Ins+Glut2LO cells to β-cell mass expansion during pregnancy. Female C57Bl/6 mice were time mated and pancreata were collected at gestational days (GD 6, 9, 12, 15, and 18, and postpartum D7 (n = 4/time-point and compared to control (non-pregnant animals. Beta cell mass, location, proliferation (Ki67+, and proportion of Ins+Glut2LO cells were measured using immunohistochemistry and bright field or confocal microscopy. Beta cell mass tripled by GD18 and β-cell proliferation peaked at GD12 in islets (≥6 β-cells and small β-cell clusters (1-5 β-cells. The proportion and fraction of Ins+Glut2LO cells undergoing proliferation increased significantly at GD9 in both islets and clusters, preceding the increase in β-cell mass and proliferation, and their proliferation within clusters persisted until GD15. The overall number of clusters increased significantly at GD9. Quantitative PCR showed a significant increase in Pdx1 presence at GD9 vs. GD18 or control pancreas, and Pdx1 was visualized by immunohistochemistry within both Ins+Glut2LO and Ins+Glut2HI cells within clusters. These results indicate that Ins+Glut2LO cells are likely to contribute to β-cell mass expansion during pregnancy.

  14. Genetic and nongenetic determinants of skeletal muscle glucose transporter 4 messenger ribonucleic acid levels and insulin action in twins

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Poulsen, Pernille; Ling, Charlotte

    2006-01-01

    -stimulated expressions of GLUT4 were independently and significantly related to whole-body in vivo insulin action, nonoxidative glucose metabolism, and glucose oxidation. CONCLUSION: We show that skeletal muscle GLUT4 gene expression in twins is significantly and independently related to glucose metabolism...

  15. Glucose transporters: expression, regulation and cancer

    Directory of Open Access Journals (Sweden)

    RODOLFO A. MEDINA

    2002-01-01

    Full Text Available Mammalian cells depend on glucose as a major substrate for energy production. Glucose is transported into the cell via facilitative glucose transporters (GLUT present in all cell types. Many GLUT isoforms have been described and their expression is cell-specific and subject to hormonal and environmental control. The kinetic properties and substrate specificities of the different isoforms are specifically suited to the energy requirements of the particular cell types. Due to the ubiquitousness of these transporters, their differential expression is involved in various disease states such as diabetes, ischemia and cancer. The majority of cancers and isolated cancer cell lines over-express the GLUT family members which are present in the respective tissue of origin under non-cancerous conditions. Moreover, due to the requirement of energy to feed uncontrolled proliferation, cancer cells often express GLUTs which under normal conditions would not be present in these tissues. This over-expression is predominantly associated with the likelihood of metastasis and hence poor patient prognosis. This article presents a review of the current literature on the regulation and expression of GLUT family members and has compiled clinical and research data on GLUT expression in human cancers and in isolated human cancer cell lines.

  16. Upregulation of Glucose Uptake and Hexokinase Activity of Primary Human CD4+ T Cells in Response to Infection with HIV-1

    Directory of Open Access Journals (Sweden)

    Maia Kavanagh Williamson

    2018-03-01

    Full Text Available Infection of primary CD4+ T cells with HIV-1 coincides with an increase in glycolysis. We investigated the expression of glucose transporters (GLUT and glycolytic enzymes in human CD4+ T cells in response to infection with HIV-1. We demonstrate the co-expression of GLUT1, GLUT3, GLUT4, and GLUT6 in human CD4+ T cells after activation, and their concerted overexpression in HIV-1 infected cells. The investigation of glycolytic enzymes demonstrated activation-dependent expression of hexokinases HK1 and HK2 in human CD4+ T cells, and a highly significant increase in cellular hexokinase enzyme activity in response to infection with HIV-1. HIV-1 infected CD4+ T cells showed a marked increase in expression of HK1, as well as the functionally related voltage-dependent anion channel (VDAC protein, but not HK2. The elevation of GLUT, HK1, and VDAC expression in HIV-1 infected cells mirrored replication kinetics and was dependent on virus replication, as evidenced by the use of reverse transcription inhibitors. Finally, we demonstrated that the upregulation of HK1 in HIV-1 infected CD4+ T cells is independent of the viral accessory proteins Vpu, Vif, Nef, and Vpr. Though these data are consistent with HIV-1 dependency on CD4+ T cell glucose metabolism, a cellular response mechanism to infection cannot be ruled out.

  17. The ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) attenuates insulin resistance through suppressing GLUT-2 in rat liver.

    Science.gov (United States)

    Sharawy, Maha H; El-Awady, Mohammed S; Megahed, Nirmeen; Gameil, Nariman M

    2016-05-01

    This study investigates the effect of the ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) on insulin resistance induced by high-fructose diet (HFD) in rats. Male Sprague Dawley rats were fed 60% HFD for 12 weeks and HMB (320 mg·kg(-1)·day(-1), orally) for 4 weeks. HFD significantly increased fasting insulin, fasting glucose, glycosylated hemoglobin (HBA1C), liver glycogen content, and homeostasis model assessment of insulin resistance (HOMA-IR) index, while it decreased glucose and insulin tolerance. Furthermore, HFD significantly increased serum triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and very low density lipoprotein cholesterol (VLDL-C) levels, while it significantly decreased high density lipoprotein cholesterol (HDL-C). Moreover, HFD significantly increased mRNA expression of glucose transporter type-2 (GLUT-2), the mammalian target of rapamycin (mTOR), and sterol regulatory element-binding protein-1c (SREBP-1c) but decreased peroxisome proliferator-activated receptor-alpha (PPAR-α) in liver. Aortic relaxation to acetylcholine (ACh) was impaired and histopathology showed severe hepatic steatosis. HMB significantly increased insulin tolerance and decreased fasting insulin, HOMA-IR, HBA1C, hepatic glycogen content, serum TG, LDL-C, and VLDL-C. Additionally, HMB enhanced ACh-induced relaxation, ameliorated hepatic steatosis, and decreased mRNA expression of GLUT-2. In conclusion, HMB may attenuate insulin resistance and hepatic steatosis through inhibiting GLUT-2 in liver.

  18. Adipose tissue insulin receptor and glucose transporter 4 expression, and blood glucose and insulin responses during glucose tolerance tests in transition Holstein cows with different body condition.

    Science.gov (United States)

    Jaakson, H; Karis, P; Ling, K; Ilves-Luht, A; Samarütel, J; Henno, M; Jõudu, I; Waldmann, A; Reimann, E; Pärn, P; Bruckmaier, R M; Gross, J J; Kaart, T; Kass, M; Ots, M

    2018-01-01

    Glucose uptake in tissues is mediated by insulin receptor (INSR) and glucose transporter 4 (GLUT4). The aim of this study was to examine the effect of body condition during the dry period on adipose tissue mRNA and protein expression of INSR and GLUT4, and on the dynamics of glucose and insulin following the i.v. glucose tolerance test in Holstein cows 21 d before (d -21) and after (d 21) calving. Cows were grouped as body condition score (BCS) ≤3.0 (thin, T; n = 14), BCS = 3.25 to 3.5 (optimal, O; n = 14), and BCS ≥3.75 (overconditioned, OC; n = 14). Blood was analyzed for glucose, insulin, fatty acids, and β-hydroxybutyrate concentrations. Adipose tissue was analyzed for INSR and GLUT4 mRNA and protein concentrations. During the glucose tolerance test 0.15 g/kg of body weight glucose was infused; blood was collected at -5, 5, 10, 20, 30, 40, 50, and 60 min, and analyzed for glucose and insulin. On d -21 the area under the curve (AUC) of glucose was smallest in group T (1,512 ± 33.9 mg/dL × min) and largest in group OC (1,783 ± 33.9 mg/dL × min), and different between all groups. Basal insulin on d -21 was lowest in group T (13.9 ± 2.32 µU/mL), which was different from group OC (24.9 ± 2.32 µU/mL. On d -21 the smallest AUC 5-60 of insulin in group T (5,308 ± 1,214 µU/mL × min) differed from the largest AUC in group OC (10,867 ± 1,215 µU/mL × min). Time to reach basal concentration of insulin in group OC (113 ± 14.1 min) was longer compared with group T (45 ± 14.1). The INSR mRNA abundance on d 21 was higher compared with d -21 in groups T (d -21: 3.3 ± 0.44; d 21: 5.9 ± 0.44) and O (d -21: 3.7 ± 0.45; d 21: 4.7 ± 0.45). The extent of INSR protein expression on d -21 was highest in group T (7.3 ± 0.74 ng/mL), differing from group O (4.6 ± 0.73 ng/mL), which had the lowest expression. The amount of GLUT4 protein on d -21 was lowest in group OC (1.2 ± 0.14 ng/mL), different from group O (1.8 ± 0.14 ng/mL), which had the highest amount

  19. Autosomal dominant transmission of GLUT1 deficiency.

    NARCIS (Netherlands)

    Klepper, J.; Willemsen, M.A.A.P.; Verrips, A.; Guertsen, E.; Herrmann, R.; Kutzick, C.; Florcken, A.; Voit, T.

    2001-01-01

    GLUT1 deficiency is caused by a defect in the facilitative glucose transporter GLUT1. Impaired glucose transport across brain tissue barriers is reflected by hypoglycorrhachia and results in an epileptic encephalopathy with developmental delay and motor disorders. Recently heterozygous mutations in

  20. [6]-Gingerol, from Zingiber officinale, potentiates GLP-1 mediated glucose-stimulated insulin secretion pathway in pancreatic β-cells and increases RAB8/RAB10-regulated membrane presentation of GLUT4 transporters in skeletal muscle to improve hyperglycemia in Leprdb/db type 2 diabetic mice.

    Science.gov (United States)

    Samad, Mehdi Bin; Mohsin, Md Nurul Absar Bin; Razu, Bodiul Alam; Hossain, Mohammad Tashnim; Mahzabeen, Sinayat; Unnoor, Naziat; Muna, Ishrat Aklima; Akhter, Farjana; Kabir, Ashraf Ul; Hannan, J M A

    2017-08-09

    [6]-Gingerol, a major component of Zingiber officinale, was previously reported to ameliorate hyperglycemia in type 2 diabetic mice. Endocrine signaling is involved in insulin secretion and is perturbed in db/db Type-2 diabetic mice. [6]-Gingerol was reported to restore the disrupted endocrine signaling in rodents. In this current study on Lepr db/db diabetic mice, we investigated the involvement of endocrine pathway in the insulin secretagogue activity of [6]-Gingerol and the mechanism(s) through which [6]-Gingerol ameliorates hyperglycemia. Lepr db/db type 2 diabetic mice were orally administered a daily dose of [6]-Gingerol (200 mg/kg) for 28 days. We measured the plasma levels of different endocrine hormones in fasting and fed conditions. GLP-1 levels were modulated using pharmacological approaches, and cAMP/PKA pathway for insulin secretion was assessed by qRT-PCR and ELISA in isolated pancreatic islets. Total skeletal muscle and its membrane fractions were used to measure glycogen synthase 1 level and Glut4 expression and protein levels. 4-weeks treatment of [6]-Gingerol dramatically increased glucose-stimulated insulin secretion and improved glucose tolerance. Plasma GLP-1 was found to be significantly elevated in the treated mice. Pharmacological intervention of GLP-1 levels regulated the effect of [6]-Gingerol on insulin secretion. Mechanistically, [6]-Gingerol treatment upregulated and activated cAMP, PKA, and CREB in the pancreatic islets, which are critical components of GLP-1-mediated insulin secretion pathway. [6]-Gingerol upregulated both Rab27a GTPase and its effector protein Slp4-a expression in isolated islets, which regulates the exocytosis of insulin-containing dense-core granules. [6]-Gingerol treatment improved skeletal glycogen storage by increased glycogen synthase 1 activity. Additionally, GLUT4 transporters were highly abundant in the membrane of the skeletal myocytes, which could be explained by the increased expression of Rab8 and Rab

  1. Placental Expression of Glucose Transporter Proteins in Pregnancies Complicated by Gestational and Pregestational Diabetes Mellitus.

    Science.gov (United States)

    Stanirowski, Paweł Jan; Szukiewicz, Dariusz; Pazura-Turowska, Monika; Sawicki, Włodzimierz; Cendrowski, Krzysztof

    2018-04-01

    Gestational diabetes mellitus and pregestational diabetes mellitus constitute carbohydrate metabolism disorders, which, if not diagnosed and adequately treated, lead to serious and often life-threatening pregnancy complications. According to a recently formulated hypothesis, some diabetes-related complications, such as fetal macrosomia, may be the result of disturbances in the transplacental transport of nutrients-in particular, excessive maternal-fetal glucose transfer. Throughout pregnancy, glucose flux across the placenta is mediated by the group of facilitative glucose transporters (GLUT), the expression of which in different placental compartments is the precondition for effective glucose uptake from maternal blood and its subsequent transfer to the fetal circulation. In diabetes-complicated pregnancies, the location, expression and activity of glucose transporters are modified to an extent that results in alterations in the maternal-fetal glucose exchange, potentially leading to an excessive supply of energy substrates to the fetus. This paper reviews the literature on the expression and activity of glucose transporter proteins-GLUT-1, GLUT-3, GLUT-4, GLUT-8, GLUT-9 and GLUT-12-in the human placenta, with a special focus on diabetes-complicated pregnancy. The characteristics of transporters in conditions of maternal normoglycemia and modifications occurring in the diabetic placenta are summarized, and the factors responsible for the regulation of the expression of selected isoforms are described. Finally, the impact of alterations in the placental expression of the aforementioned members of the GLUT family on intrauterine fetal development in pregnancies complicated by diabetes mellitus is discussed. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  2. Gallic acid attenuates high-fat diet fed-streptozotocin-induced insulin resistance via partial agonism of PPARγ in experimental type 2 diabetic rats and enhances glucose uptake through translocation and activation of GLUT4 in PI3K/p-Akt signaling pathway.

    Science.gov (United States)

    Gandhi, Gopalsamy Rajiv; Jothi, Gnanasekaran; Antony, Poovathumkal James; Balakrishna, Kedike; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu; Stalin, Antony; Al-Dhabi, Naif Abdullah

    2014-12-15

    In this study, the therapeutic efficacy of gallic acid from Cyamopsis tetragonoloba (L.) Taub. (Fabaceae) beans was examined against high-fat diet fed-streptozotocin-induced experimental type 2 diabetic rats. Molecular-dockings were done to determine the putative binding modes of gallic acid into the active sites of key insulin-signaling markers. Gallic acid (20 mg/kg) given to high-fat diet fed-streptozotocin-induced rats lowered body weight gain, fasting blood glucose and plasma insulin in diabetic rats. It further restored the alterations of biochemical parameters to near normal levels in diabetic treated rats along with cytoprotective action on pancreatic β-cell. Histology of liver and adipose tissues supported the biochemical findings. Gallic acid significantly enhanced the level of peroxisome proliferator-activated receptor γ (PPARγ) expression in the adipose tissue of treated rat compared to untreated diabetic rat; it also slightly activated PPARγ expressions in the liver and skeletal muscle. Consequently, it improved insulin-dependent glucose transport in adipose tissue through translocation and activation of glucose transporter protein 4 (GLUT4) in phosphatidylinositol 3-kinase (PI3K)/phosphorylated protein kinase B (p-Akt) dependent pathway. Gallic acid docked with PPARγ; it exhibited promising interactions with the GLUT4, glucose transporter protein 1 (GLUT1), PI3K and p-Akt. These findings provided evidence to show that gallic acid could improve adipose tissue insulin sensitivity, modulate adipogenesis, increase adipose glucose uptake and protect β-cells from impairment. Hence it can be used in the management of obesity-associated type 2 diabetes mellitus. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Severe Hypertriglyceridemia in Glut1D on Ketogenic Diet.

    Science.gov (United States)

    Klepper, Joerg; Leiendecker, Baerbel; Heussinger, Nicole; Lausch, Ekkehart; Bosch, Friedrich

    2016-04-01

    High-fat ketogenic diets are the only treatment available for Glut1 deficiency (Glut1D). Here, we describe an 8-year-old girl with classical Glut1D responsive to a 3:1 ketogenic diet and ethosuximide. After 3 years on the diet a gradual increase of blood lipids was followed by rapid, severe asymptomatic hypertriglyceridemia (1,910 mg/dL). Serum lipid apheresis was required to determine liver, renal, and pancreatic function. A combination of medium chain triglyceride-oil and a reduction of the ketogenic diet to 1:1 ratio normalized triglyceride levels within days but triggered severe myoclonic seizures requiring comedication with sultiam. Severe hypertriglyceridemia in children with Glut1D on ketogenic diets may be underdiagnosed and harmful. In contrast to congenital hypertriglyceridemias, children with Glut1D may be treated effectively by dietary adjustments alone. Georg Thieme Verlag KG Stuttgart · New York.

  4. Effects of rhizoma polygonati on the expression of glucose transporter-4 gene in type 2 diabetes mellitus rats with insulin resistance%黄精对2型糖尿病胰岛素抵抗大鼠葡萄糖转运蛋白-4基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    董琦; 董凯; 张春军

    2012-01-01

    Objective To observe the effects of rhizoma polygonati( RP) on the expression of glucose transporter-4 (GLUT-4) gene in muscular tissue in type 2 diabetes mellitus(T2DM) rats with insulin resistance(IR). Methods The model of T2DM rats with insulin resistance was established by giving high fat, high caloric diet and injection of small dose of strep-tozotocin(STZ). The model rats were divided into model control group, high, middle and low doses RP groups( inlragastric administration 10.0,5.0,2.5 g o kg-1 o d-1 RP). Other 10 rats were selected as normal control group. After intragastric administration for eight weeks,then the GLUT-4 mRNA in muscular tissue was determined by reverse transcription-polymerase chain reaction(RT-PCR). Results Compared with normal control group,the expressions of GLUT-4 mRNA were lower(P <0.01), but the levels of fasting plasma glucose(FPG) were higher(P <0. 01) in model control group,low,middle and high doses RP groups. Compared with model control group,the levels of FPG were lower in low,middle and high doses RP groups,and the decreasing level in middle and high doses RP groups was obviously( P < 0.01 ) ; the expressions of GLUT-4 mRNA were higher in low,middle and high doses RP groups,and the increasing level in middle and high doses RP groups was obviously(P<0.01 ). Conclusion RP can reduce blood glucose by increasing expression of GLUT-4 mRNA in T2DM rats with IR.%目的 观察黄精水提液对2型糖尿病(T2DM)胰岛素抵抗大鼠肌肉组织葡萄糖转运蛋白-4(GLUT-4)基因表达的影响.方法 采用小剂量链脲佐菌素加高脂高热量饲料喂养方法建立2型糖尿病胰岛素抵抗模型,将造模大鼠随机分为模型对照组和黄精高、中、低剂量治疗组(分别灌胃10.0、5.0、2.5g·kg-1·d-1),另选10只为正常对照组.灌胃8周后,空腹取材,反转录-聚合酶链反应法检测肌肉组织GLUT-4基因mRNA水平.结果 与正常对照组相比,模型对照组及黄精高、中、低剂量治疗组大鼠GLUT

  5. Lifelong Physical Activity Prevents Aging-Associated Insulin Resistance in Human Skeletal Muscle Myotubes via Increased Glucose Transporter Expression

    DEFF Research Database (Denmark)

    Bunprajun, Tipwadee; Henriksen, Tora Ida; Scheele, Camilla

    2013-01-01

    , and significantly higher GLUT4 protein. It is likely that physical activity induces a number of stable adaptations, including increased GLUT4 expression that are retained in cells ex vivo and protect, or delay the onset of middle-aged-associated insulin resistance. Additionally, a sedentary lifestyle has an impact...

  6. The Global Saving Glut in the light of demographic developments : a numerical simulation of the developments in China and the US

    OpenAIRE

    Pettersen, Malin Karlberg; Håland, Marianne

    2016-01-01

    The objective of this thesis is to predict how demographic developments will affect the Global Saving Glut. The thesis examines how the changes in the age structure in China and the US are affecting their respective aggregate savings rates. Ben Bernanke was the first economist to mention the term Global Saving Glut, which describes an economy where desired saving exceeds desired investment. He states that the increase in the global supply of savings was one of the main reasons ...

  7. Autosomal recessive inheritance of GLUT1 deficiency syndrome.

    NARCIS (Netherlands)

    Klepper, J.; Scheffer, H.; Elsaid, M.F.; Kamsteeg, E.J.; Leferink, M.; Ben-Omran, T.

    2009-01-01

    GLUT1 deficiency syndrome (GLUT1DS) is understood as a monogenetic disease caused by heterozygous SLC2A1 gene mutations with autosomaldominant and sporadic transmission. We report on a six-year-old girl from an inbred Arab family with moderate global developmental delay, epilepsy, ataxia, hypotonia,

  8. Glucose transporter 1 and monocarboxylate transporters 1, 2, and 4 localization within the glial cells of shark blood-brain-barriers.

    Directory of Open Access Journals (Sweden)

    Carolina Balmaceda-Aguilera

    Full Text Available Although previous studies showed that glucose is used to support the metabolic activity of the cartilaginous fish brain, the distribution and expression levels of glucose transporter (GLUT isoforms remained undetermined. Optic/ultrastructural immunohistochemistry approaches were used to determine the expression of GLUT1 in the glial blood-brain barrier (gBBB. GLUT1 was observed solely in glial cells; it was primarily located in end-feet processes of the gBBB. Western blot analysis showed a protein with a molecular mass of 50 kDa, and partial sequencing confirmed GLUT1 identity. Similar approaches were used to demonstrate increased GLUT1 polarization to both apical and basolateral membranes in choroid plexus epithelial cells. To explore monocarboxylate transporter (MCT involvement in shark brain metabolism, the expression of MCTs was analyzed. MCT1, 2 and 4 were expressed in endothelial cells; however, only MCT1 and MCT4 were present in glial cells. In neurons, MCT2 was localized at the cell membrane whereas MCT1 was detected within mitochondria. Previous studies demonstrated that hypoxia modified GLUT and MCT expression in mammalian brain cells, which was mediated by the transcription factor, hypoxia inducible factor-1. Similarly, we observed that hypoxia modified MCT1 cellular distribution and MCT4 expression in shark telencephalic area and brain stem, confirming the role of these transporters in hypoxia adaptation. Finally, using three-dimensional ultrastructural microscopy, the interaction between glial end-feet and leaky blood vessels of shark brain was assessed in the present study. These data suggested that the brains of shark may take up glucose from blood using a different mechanism than that used by mammalian brains, which may induce astrocyte-neuron lactate shuttling and metabolic coupling as observed in mammalian brain. Our data suggested that the structural conditions and expression patterns of GLUT1, MCT1, MCT2 and MCT4 in shark

  9. MicroRNA-223 Expression Is Upregulated in Insulin Resistant Human Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Tung-Yueh Chuang

    2015-01-01

    Full Text Available MicroRNAs (miRNAs are short noncoding RNAs involved in posttranscriptional regulation of gene expression and influence many cellular functions including glucose and lipid metabolism. We previously reported that adipose tissue (AT from women with polycystic ovary syndrome (PCOS or controls with insulin resistance (IR revealed a differentially expressed microRNA (miRNA profile, including upregulated miR-93 in PCOS patients and in non-PCOS women with IR. Overexpressed miR-93 directly inhibited glucose transporter isoform 4 (GLUT4 expression, thereby influencing glucose metabolism. We have now studied the role of miR-223, which is also abnormally expressed in the AT of IR subjects. Our data indicates that miR-223 is significantly overexpressed in the AT of IR women, regardless of whether they had PCOS or not. miR-223 expression in AT was positively correlated with HOMA-IR. Unlike what is reported in cardiomyocytes, overexpression of miR-223 in human differentiated adipocytes was associated with a reduction in GLUT4 protein content and insulin-stimulated glucose uptake. In addition, our data suggests miR-223 regulates GLUT4 expression by direct binding to its 3′ untranslated region (3′UTR. In conclusion, in AT miR-223 is an IR-related miRNA that may serve as a potential therapeutic target for the treatment of IR-related disorders.

  10. GLUT4 and glycogen synthase are key players in bed rest-induced insulin resistance

    DEFF Research Database (Denmark)

    Biensø, Rasmus Sjørup; Jørgensen, Stine Ringholm; Kiilerich, Kristian

    2012-01-01

    To elucidate the molecular mechanisms behind physical inactivity-induced insulin resistance in skeletal muscle, 12 young, healthy male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies obtained before and after. In six of the subjects, muscle biopsies were taken from both...... than before bed rest. This bed rest-induced insulin resistance occurred together with reduced muscle GLUT4, hexokinase II, protein kinase B/Akt1, and Akt2 protein level, and a tendency for reduced 3-hydroxyacyl-CoA dehydrogenase activity. The ability of insulin to phosphorylate Akt and activate....... The present findings demonstrate that physical inactivity-induced insulin resistance in muscle is associated with lower content/activity of key proteins in glucose transport/phosphorylation and storage....

  11. CD63 and GLUT-1 Overexpression Could Predict a Poor Clinical Outcome in GIST: A Study of 54 Cases with Follow-Up

    Directory of Open Access Journals (Sweden)

    Piotr Lewitowicz

    2016-01-01

    Full Text Available Background and Goals. In light of current knowledge, it seems that alternations underlying GISTs are well explained, although all that is enhanced by various aspects on a daily basis. More recently, attention has been pointed towards exosomes as important particles able to modify healthy and also diseased tissues including cancer. The goal of the present study was an analysis of CD9, CD63, and GLUT-1 as a marker of hypoxia status within 54 cases of GIST and evaluation of their predictive value. Methods. 54 cases of patients suffering from GIST were enrolled into the study, predominantly in the gastric location. All operated cases had no Imatinib and other chemotherapies up to the day of operation. Expression of targeted proteins was performed by immunohistochemistry and, after that, the results with tabulated clinical data were compared by Kaplan-Meier method and multivariate Cox proportional hazard model of statistical analysis. Results. Our results presented a marked dependence of worsening clinical outcome with high expression CD63 (p=0.008 as well as with GLUT-1 (p=0.014. We noted a strict correlation of GLUT-1 expression with CD63 expression (p=0.03, which could confirm the thesis about the contribution of exosomes in intratumoural hypoxia status. The collected material did not confirm CD9 contribution. Conclusions. As presented here, CD63 and GLUT-1 have a prognostic value in GIST cases. The results confirm the other studies in this scope and can be used in future as an additional prognostic factor.

  12. Immunohistochemical expression of glucose transporter 1 in keratin-producing odontogenic cysts.

    Science.gov (United States)

    Vera-Sirera, Beatriz; Forner-Navarro, Leopoldo; Vera-Sempere, Francisco

    2016-03-10

    Keratin-producing odontogenic cysts (KPOCs) are a group of cystic lesions that are often aggressive, with high rates of recurrence and multifocality. KPOCs included orthokeratinised odontogenic cyst (OOC) and parakeratotic odontogenic cysts, which are now considered true tumours denominated keratocystic odontogenic tumours (KCOTs). GLUT1 is a protein transporter that is involved in the active uptake of glucose across cell membranes and that is overexpressed in tumours in close correlation with the proliferation rate and positron emission tomography (PET) imaging results. A series of 58 keratin-producing odontogenic cysts was evaluated histologically and immunohistochemically in terms of GLUT1 expression. Different data were correlated using the beta regression model in relation to histological type and immunohistochemical expression of GLUT1, which was quantified using two different morphological methods. KPOC cases comprised 12 OOCs and 46 KCOTs, the latter corresponding to 6 syndromic and 40 sporadic KCOTs. GLUT1 expression was very low in OOC cases compared with KCOT cases, with statistical significant differences when quantification was considered. Different GLUT1 localisation patterns were revealed by immunostaining, with the parabasal cells showing higher reactivity in KCOTs. However, among KCOTs cases, GLUT1 expression was unable to establish differences between syndromic and sporadic cases. GLUT1 expression differentiated between OOC and KCOT cases, with significantly higher expression in KCOTs, but did not differentiate between syndromic and sporadic KCOT cases. However, given the structural characteristics of KCOTs, we hypothesised that PET imaging methodology is probably not a useful diagnostic tool for KCOTs. Further studies of GLUT1 expression and PET examination in KCOT series are needed to confirm this last hypothesis.

  13. The Influence of Tissue Ischemia on Biomarker Expression in Colorectal Cancer

    DEFF Research Database (Denmark)

    Havelund, Birgitte M; Aalund Olsen, Dorte; Andersen, Rikke F

    2013-01-01

    The aim of the present study was to investigate the influence of fixation delay and the perioperative ischemia on hypoxia inducible factor (HIF)-1α gene expression, HIF-1α protein expression, and immunohistochemical (IHC) expression of HIF-1α, GLUT-1, Bcl-2, and Ki-67 in colorectal cancer....... The study included 25 surgically removed colorectal tumors. Three sets of samples were collected readily after removal and exposed to 0, 30, and 60 minutes of delay of fixation or freezing. The perioperative ischemia time was registered. In each set of the samples, HIF-1α gene expression was analyzed...... by IHC. We found that the HIF-1α gene expression, HIF-1α protein concentration, and IHC expression of HIF-1α, GLUT-1, Ki-67, and Bcl-2 were not systematically affected by either the fixation or freezing delay of the tissue, the perioperative ischemia time, or the total ischemia time (perioperative...

  14. Tunable GLUT-Hexose Binding and Transport via Modulation of Hexose C-3 Hydrogen-Bonding Capabilities.

    Science.gov (United States)

    Kumar Kondapi, Venkata Pavan; Soueidan, Olivier-Mohamad; Cheeseman, Christopher I; West, Frederick G

    2017-06-12

    The importance of the hydrogen bonding interactions in the GLUT-hexose binding process (GLUT=hexose transporter) has been demonstrated by studying the binding of structurally modified d-fructose analogues to GLUTs, and in one case its transport into cells. The presence of a hydrogen bond donor at the C-3 position of 2,5-anhydro-d-mannitol derivatives is essential for effective binding to GLUT5 and transport into tumor cells. Surprisingly, installation of a group that can function only as a hydrogen bond acceptor at C-3 resulted in selective recognition by GLUT1 rather than GLUT5. A fluorescently labelled analogue clearly showed GLUT-mediated transport and low efflux properties of the probe. This study reveals that a single positional modification of a 2,5-anhydro-d-mannitol derivative is sufficient to switch its binding preference from GLUT5 to GLUT1, and uncovers general scaffolds that are suitable for the potential selective delivery of molecular payloads into tumor cells via GLUT transport machinery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Molecular Dynamics Simulations of the Human Glucose Transporter GLUT1.

    Directory of Open Access Journals (Sweden)

    Min-Sun Park

    Full Text Available Glucose transporters (GLUTs provide a pathway for glucose transport across membranes. Human GLUTs are implicated in devastating diseases such as heart disease, hyper- and hypo-glycemia, type 2 diabetes and cancer. The human GLUT1 has been recently crystalized in the inward-facing open conformation. However, there is no other structural information for other conformations. The X-ray structures of E. coli Xylose permease (XylE, a glucose transporter homolog, are available in multiple conformations with and without the substrates D-xylose and D-glucose. XylE has high sequence homology to human GLUT1 and key residues in the sugar-binding pocket are conserved. Here we construct a homology model for human GLUT1 based on the available XylE crystal structure in the partially occluded outward-facing conformation. A long unbiased all atom molecular dynamics simulation starting from the model can capture a new fully opened outward-facing conformation. Our investigation of molecular interactions at the interface between the transmembrane (TM domains and the intracellular helices (ICH domain in the outward- and inward-facing conformation supports that the ICH domain likely stabilizes the outward-facing conformation in GLUT1. Furthermore, inducing a conformational transition, our simulations manifest a global asymmetric rocker switch motion and detailed molecular interactions between the substrate and residues through the water-filled selective pore along a pathway from the extracellular to the intracellular side. The results presented here are consistent with previously published biochemical, mutagenesis and functional studies. Together, this study shed light on the structure and functional relationships of GLUT1 in multiple conformational states.

  16. GLUT-1 DEFICIENCY: FROM PATHOPHYSILOGY AND GENETICS TO ABROAD CLINICAL SPECTRUM

    Directory of Open Access Journals (Sweden)

    Arsov Todor

    2016-07-01

    Full Text Available The classical GLUT-1 deficiency syndrome (GLUT-1 DS, De Vivo disease was described over 2 decades ago as a metabolic encephalopathy characterized by developmental delay, secondary microcephaly paroxysmal neurological symptoms (epilepsy and movement disorders. The biochemical parameters of this disease, used in diagnosis, are low levels of glucose in the cerebrospinal fluid, normal level of glucose in the blood and consequent low ratio of cerebrospinal fluid vs. blood glucose levels (<40-45%. So far, more than 200 cases of the classical GLUT-1 DS have been described in the literature. Genetic research demonstrated that this disease is caused by mutations in SLC2A1 gene coding for GLUT-1, a transporter of glucose across the blood brain barrier. Over the last few years the clinical spectrum of GLUT-1 deficiencywas expanded to include other rare diseases such as paroxysmal exertional dyskinesia and early-onset absence epilepsy, but also some more common diseases such as idiopathic generalised epilepsy (1-2%. GLUT-1 deficiency is an important pathophysiological basis of these diseases as early diagnosis (aided by DNA mutation testing and treatment (ketogenic diet could lead to improved disease outcomes.

  17. Glucose metabolism transporters and epilepsy: only GLUT1 has an established role.

    Science.gov (United States)

    Hildebrand, Michael S; Damiano, John A; Mullen, Saul A; Bellows, Susannah T; Oliver, Karen L; Dahl, Hans-Henrik M; Scheffer, Ingrid E; Berkovic, Samuel F

    2014-02-01

    The availability of glucose, and its glycolytic product lactate, for cerebral energy metabolism is regulated by specific brain transporters. Inadequate energy delivery leads to neurologic impairment. Haploinsufficiency of the glucose transporter GLUT1 causes a characteristic early onset encephalopathy, and has recently emerged as an important cause of a variety of childhood or later-onset generalized epilepsies and paroxysmal exercise-induced dyskinesia. We explored whether mutations in the genes encoding the other major glucose (GLUT3) or lactate (MCT1/2/3/4) transporters involved in cerebral energy metabolism also cause generalized epilepsies. A cohort of 119 cases with myoclonic astatic epilepsy or early onset absence epilepsy was screened for nucleotide variants in these five candidate genes. No epilepsy-causing mutations were identified, indicating that of the major energetic fuel transporters in the brain, only GLUT1 is clearly associated with generalized epilepsy. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

  18. The Role of Hypoxia-Inducible Factor-1α, Glucose Transporter-1, (GLUT-1 and Carbon Anhydrase IX in Endometrial Cancer Patients

    Directory of Open Access Journals (Sweden)

    Pawel Sadlecki

    2014-01-01

    Full Text Available Hypoxia-inducible factor-1α (HIF-1α, glucose transporter-1 (GLUT-1, and carbon anhydrase IX (CAIX are important molecules that allow adaptation to hypoxic environments. The aim of our study was to investigate the correlation between HIF-1α, GLUT-1, and CAIX protein level with the clinicopathological features of endometrial cancer patients. Materials and Methods. 92 endometrial cancer patients, aged 37–84, were enrolled to our study. In all patients clinical stage, histologic grade, myometrial invasion, lymph node, and distant metastases were determined. Moreover, the survival time was assessed. Immunohistochemical analyses were performed on archive formalin fixed paraffin embedded tissue sections. Results. High significant differences (P=0.0115 were reported between HIF-1α expression and the histologic subtype of cancer. Higher HIF-1α expression was associated with the higher risk of recurrence (P=0.0434. The results of GLUT-1 and CAIX expression did not reveal any significant differences between the proteins expression in the primary tumor and the clinicopathological features. Conclusion. The important role of HIF-1α in the group of patients with the high risk of recurrence and the negative histologic subtype of the tumor suggest that the expression of this factor might be useful in the panel of accessory pathomorphological tests and could be helpful in establishing more accurate prognosis in endometrial cancer patients.

  19. Culture Conditions Affect Expression of DUX4 in FSHD Myoblasts

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    Sachchida Nand Pandey

    2015-05-01

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is believed to be caused by aberrant expression of double homeobox 4 (DUX4 due to epigenetic changes of the D4Z4 region at chromosome 4q35. Detecting DUX4 is challenging due to its stochastic expression pattern and low transcription level. In this study, we examined different cDNA synthesis strategies and the sensitivity for DUX4 detection. In addition, we investigated the effects of dexamethasone and knockout serum replacement (KOSR on DUX4 expression in culture. Our data showed that DUX4 was consistently detected in cDNA samples synthesized using Superscript III. The sensitivity of DUX4 detection was higher in the samples synthesized using oligo(dT primers compared to random hexamers. Adding dexamethasone to the culture media significantly suppressed DUX4 expression in immortalized (1.3 fold, p < 0.01 and primary (4.7 fold, p < 0.01 FSHD myoblasts, respectively. Culture medium with KOSR increased DUX4 expression and the response is concentration dependent. The findings suggest that detection strategies and culture conditions should be carefully considered when studying DUX4 in cultured cells.

  20. GLUT1 deficiency syndrome into adulthood: a follow-up study

    NARCIS (Netherlands)

    Leen, W.G.; Taher, M.; Verbeek, M.M.; Kamsteeg, E.J.; Warrenburg, B.P.C. van de; Willemsen, M.A.

    2014-01-01

    GLUT1 deficiency syndrome (GLUT1DS) is a treatable neurometabolic disorder in which glucose transport into the brain is disturbed. Besides the classic phenotype of intellectual disability, epilepsy, and movement disorders, other phenotypes are increasingly recognized. These include, for example,

  1. Inhibitors of GLUT/SLC2A Enhance the Action of BCNU and Temozolomide against High-Grade Gliomas

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    Alberto Azzalin

    2017-04-01

    Full Text Available Glucose transport across glioblastoma membranes plays a crucial role in maintaining the enhanced glycolysis typical of high-grade gliomas and glioblastoma. We tested the ability of two inhibitors of the glucose transporters GLUT/SLC2A superfamily, indinavir (IDV and ritonavir (RTV, and of one inhibitor of the Na/glucose antiporter type 2 (SGLT2/SLC5A2 superfamily, phlorizin (PHZ, in decreasing glucose consumption and cell proliferation of human and murine glioblastoma cells. We found in vitro that RTV, active on at least three different GLUT/SLC2A transporters, was more effective than IDV, a specific inhibitor of GLUT4/SLC2A4, both in decreasing glucose consumption and lactate production and in inhibiting growth of U87MG and Hu197 human glioblastoma cell lines and primary cultures of human glioblastoma. PHZ was inactive on the same cells. Similar results were obtained when cells were grown in adherence or as 3D multicellular tumor spheroids. RTV treatment but not IDV treatment induced AMP-activated protein kinase (AMPKα phosphorylation that paralleled the decrease in glycolytic activity and cell growth. IDV, but not RTV, induced an increase in GLUT1/SLC2A1 whose activity could compensate for the inhibition of GLUT4/SLC2A4 by IDV. RTV and IDV pass poorly the blood brain barrier and are unlikely to reach sufficient liquoral concentrations in vivo to inhibit glioblastoma growth as single agents. Isobologram analysis of the association of RTV or IDV and 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU or 4-methyl-5-oxo-2,3,4,6,8-pentazabicyclo[4.3.0]nona-2,7,9-triene-9-carboxamide (TMZ indicated synergy only with RTV on inhibition of glioblastoma cells. Finally, we tested in vivo the combination of RTV and BCNU on established GL261 tumors. This drug combination increased the overall survival and allowed a five-fold reduction in the dose of BCNU.

  2. Insulin-Like Growth Factor (IGF Binding Protein-2, Independently of IGF-1, Induces GLUT-4 Translocation and Glucose Uptake in 3T3-L1 Adipocytes

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    Biruhalem Assefa

    2017-01-01

    Full Text Available Insulin-like growth factor binding protein-2 (IGFBP-2 is the predominant IGF binding protein produced during adipogenesis and is known to increase the insulin-stimulated glucose uptake (GU in myotubes. We investigated the IGFBP-2-induced changes in basal and insulin-stimulated GU in adipocytes and the underlying mechanisms. We further determined the role of insulin and IGF-1 receptors in mediating the IGFBP-2 and the impact of IGFBP-2 on the IGF-1-induced GU. Fully differentiated 3T3-L1 adipocytes were treated with IGFBP-2 in the presence and absence of insulin and IGF-1. Insulin, IGF-1, and IGFBP-2 induced a dose-dependent increase in GU. IGFBP-2 increased the insulin-induced GU after long-term incubation. The IGFBP-2-induced impact on GU was neither affected by insulin or IGF-1 receptor blockage nor by insulin receptor knockdown. IGFBP-2 significantly increased the phosphorylation of PI3K, Akt, AMPK, TBC1D1, and PKCζ/λ and induced GLUT-4 translocation. Moreover, inhibition of PI3K and AMPK significantly reduced IGFBP-2-stimulated GU. In conclusion, IGFBP-2 stimulates GU in 3T3-L1 adipocytes through activation of PI3K/Akt, AMPK/TBC1D1, and PI3K/PKCζ/λ/GLUT-4 signaling. The stimulatory effect of IGFBP-2 on GU is independent of its binding to IGF-1 and is possibly not mediated through the insulin or IGF-1 receptor. This study highlights the potential role of IGFBP-2 in glucose metabolism.

  3. GLUT1 deficiency with delayed myelination responding to ketogenic diet.

    NARCIS (Netherlands)

    Klepper, J.; Engelbrecht, V.; Scheffer, H.; Knaap, M.S. van der; Fiedler, A.

    2007-01-01

    Monitoring effects of a ketogenic diet in GLUT1 deficiency syndrome without seizures is difficult. Neuroimaging is considered uninformative. We report the case of a boy with neurodevelopmental delay, severe ataxia, an E54X-mutation in the SLC2A1 gene (previously GLUT1), and neuroimaging

  4. GLUT1 deficiency with delayed myelination responding to ketogenic diet

    NARCIS (Netherlands)

    Klepper, Jörg; Engelbrecht, Volkher; Scheffer, Hans; van der Knaap, Marjo S.; Fiedler, Andreas

    2007-01-01

    Monitoring effects of a ketogenic diet in GLUT1 deficiency syndrome without seizures is difficult. Neuroimaging is considered uninformative. We report the case of a boy with neurodevelopmental delay, severe ataxia, an E54X-mutation in the SLC2A1 gene (previously GLUT1), and neuroimaging

  5. Association of a common nonsynonymous variant in GLUT9 with serum uric acid levels in old order amish.

    Science.gov (United States)

    McArdle, Patrick F; Parsa, Afshin; Chang, Yen-Pei C; Weir, Matthew R; O'Connell, Jeffery R; Mitchell, Braxton D; Shuldiner, Alan R

    2008-09-01

    Uric acid is the primary end product of purine metabolism. Increased serum uric acid levels have been associated with gouty arthritis as well as with a variety of cardiovascular-related phenotypes. This study was undertaken to investigate associations between uric acid levels and single-nucleotide polymorphisms (SNPs). A 500,000-SNP genome-wide association study of serum uric acid levels was performed in a cohort of Old Order Amish from Lancaster County, Pennsylvania. The scan confirmed a previously identified region on chromosome 4 to be strongly associated with uric acid levels (P = 4.2 x 10(-11) for rs10489070). Followup genotyping revealed that a nonsynonymous coding SNP (Val253Ile; rs16890979) in GLUT9 was most strongly associated with uric acid levels, with each copy of the minor allele associated with a decrease of 0.47 mg/dl in the uric acid level (95% confidence interval 0.31-0.63 [P = 1.43 x 10(-11)]). The effect of this variant tended to be stronger in women than in men (P = 0.16 for sex-genotype interaction). The genotype effect was not modified by the inclusion of several cardiovascular risk factors, suggesting that GLUT9 is directly related to uric acid homeostasis. The SNP identified in the genome-wide scan in the Amish population (rs10489070) was also significantly associated with gout in the Framingham Heart Study (P = 0.004). Our findings indicate that GLUT9, which is expressed in the kidney, may be a novel regulator of uric acid elimination and that a common nonsynonymous variant in this gene contributes to abnormalities in uric acid homeostasis and gout.

  6. Photoperiodic regulation of the sucrose transporter StSUT4 affects the expression of circadian-regulated genes and ethylene production

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    Izabela eChincinska

    2013-02-01

    Full Text Available Several recent publications report different subcellular localisation of members of the SUT4 subfamily of sucrose transporters. The physiological function of SUT4 sucrose transporters is still not entirely clarified as down-regulation of members of the SUT4 clade had very different effects in rice, poplar and potato. Here, we provide new data on the localization and function of the Solanaceous StSUT4 protein, further elucidating involvement in the onset of flowering, tuberization and in the shade avoidance syndrome of potato plants.Induction of early flowering and tuberization in SUT4-inhibited potato plants correlates with increased sucrose export from leaves and increased sucrose and starch accumulation in terminal sink organs such as developing tubers. SUT4 does not only affect the expression of gibberellin and ethylene biosynthetic enzymes, but also the rate of ethylene synthesis in potato. In SUT4-inhibited plants, the ethylene production no longer follows a diurnal rhythm, leading to the assumption that StSUT4 controls circadian gene expression, potentially by regulating sucrose export from leaves. Furthermore, SUT4 expression affects clock-regulated genes such as StFT, StSOC1 and StCO, which might also be involved in a photoperiod-dependently controlled tuberization. A model is proposed in which StSUT4 controls a phloem-mobile signalling molecule generated in leaves which together with enhanced sucrose export affects developmental switches in apical meristems. SUT4 seems to link photoreceptor-perceived information about the light quality and day length, with phytohormone biosynthesis and the expression of circadian genes.

  7. Radiopharmacological evaluation of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose as a radiotracer for PET imaging of GLUT5 in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Melinda, E-mail: mwuest@ualberta.c [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Trayner, Brendan J. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Grant, Tina N. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Jans, Hans-Soenke; Mercer, John R.; Murray, David [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); West, Frederick G. [Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); McEwan, Alexander J.B.; Wuest, Frank [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Cheeseman, Chris I. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada)

    2011-05-15

    Introduction: Several clinical studies have shown low or no expression of GLUT1 in breast cancer patients, which may account for the low clinical specificity and sensitivity of 2-deoxy-2-[{sup 18}F]fluoro-D-glucose ([{sup 18}F]FDG) used in positron emission tomography (PET). Therefore, it has been proposed that other tumor characteristics such as the high expression of GLUT2 and GLUT5 in many breast tumors could be used to develop alternative strategies to detect breast cancer. Here we have studied the in vitro and in vivo radiopharmacological profile of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose (6-[{sup 18}F]FDF) as a potential PET radiotracer to image GLUT5 expression in breast cancers. Methods: Uptake of 6-[{sup 18}F]FDF was studied in murine EMT-6 and human MCF-7 breast cancer cells over 60 min and compared to [{sup 18}F]FDG. Biodistribution of 6-[{sup 18}F]FDF was determined in BALB/c mice. Tumor uptake was studied with dynamic small animal PET in EMT-6 tumor-bearing BALB/c mice and human xenograft MCF-7 tumor-bearing NIH-III mice in comparison to [{sup 18}F]FDG. 6-[{sup 18}F]FDF metabolism was investigated in mouse blood and urine. Results: 6-[{sup 18}F]FDF is taken up by EMT-6 and MCF-7 breast tumor cells independent of extracellular glucose levels but dependent on the extracellular concentration of fructose. After 60 min, 30{+-}4% (n=9) and 12{+-}1% (n=7) ID/mg protein 6-[{sup 18}F]FDF was found in EMT-6 and MCF-7 cells, respectively. 6-deoxy-6-fluoro-D-fructose had a 10-fold higher potency than fructose to inhibit 6-[{sup 18}F]FDF uptake into EMT-6 cells. Biodistribution in normal mice revealed radioactivity uptake in bone and brain. Radioactivity was accumulated in EMT-6 tumors reaching 3.65{+-}0.30% ID/g (n=3) at 5 min post injection and decreasing to 1.75{+-}0.03% ID/g (n=3) at 120 min post injection. Dynamic small animal PET showed significantly lower radioactivity uptake after 15 min post injection in MCF-7 tumors [standard uptake value (SUV)=0

  8. Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes.

    Science.gov (United States)

    Chaudhary, Natasha; Gonzalez, Eva; Chang, Sung-Hee; Geng, Fuqiang; Rafii, Shahin; Altorki, Nasser K; McGraw, Timothy E

    2016-12-20

    Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin's effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  9. Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes

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    Natasha Chaudhary

    2016-12-01

    Full Text Available Insulin activation of phosphatidylinositol 3-kinase (PI3K regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin’s effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types.

  10. Differential expression of microRNAs in omental adipose tissue from gestational diabetes mellitus subjects reveals miR-222 as a regulator of ERα expression in estrogen-induced insulin resistance.

    Science.gov (United States)

    Shi, Zhonghua; Zhao, Chun; Guo, Xirong; Ding, Hongjuan; Cui, Yugui; Shen, Rong; Liu, Jiayin

    2014-05-01

    Omental adipose tissue plays a central role in insulin resistance in gestational diabetes mellitus (GDM), and the molecular mechanisms leading to GDM remains vague. Evidence demonstrates that maternal hormones, such as estradiol, contribute to insulin resistance in GDM. In this study we determined the differential expression patterns of microRNAs (miRNAs) in omental adipose tissues from GDM patients and pregnant women with normal glucose tolerance using AFFX miRNA expression chips. MiR-222, 1 of 17 identified differentially expressed miRNAs, was found to be significantly up-regulated in GDM by quantitative real-time PCR (P insulin-sensitive membrane transporter glucose transporter 4 (GLUT4) protein (P insulin-stimulated translocation of GLUT4 from the cytoplasm to the cell membrane and glucose uptake in mature adipocytes were dramatically increased (P insulin resistance in GDM and might be a candidate biomarker and therapeutic target for GDM.

  11. Comparative study of expression and activity of glucose transporters between stem cell-derived brain microvascular endothelial cells and hCMEC/D3 cells.

    Science.gov (United States)

    Al-Ahmad, Abraham J

    2017-10-01

    Glucose constitutes a major source of energy of mammalian brains. Glucose uptake at the blood-brain barrier (BBB) occurs through a facilitated glucose transport, through glucose transporter 1 (GLUT1), although other isoforms have been described at the BBB. Mutations in GLUT1 are associated with the GLUT1 deficiency syndrome, yet none of the current in vitro models of the human BBB maybe suited for modeling such a disorder. In this study, we investigated the expression of glucose transporters and glucose diffusion across brain microvascular endothelial cells (BMECs) derived from healthy patient-derived induced pluripotent stem cells (iPSCs). We investigated the expression of different glucose transporters at the BBB using immunocytochemistry and flow cytometry and measured glucose uptake and diffusion across BMEC monolayers obtained from two iPSC lines and from hCMEC/D3 cells. BMEC monolayers showed expression of several glucose transporters, in particular GLUT1, GLUT3, and GLUT4. Diffusion of glucose across the monolayers was mediated via a saturable transcellular mechanism and partially inhibited by pharmacological inhibitors. Taken together, our study suggests the presence of several glucose transporters isoforms at the human BBB and demonstrates the feasibility of modeling glucose across the BBB using patient-derived stem cells. Copyright © 2017 the American Physiological Society.

  12. Attenuation of insulin resistance in rats by agmatine: role of SREBP-1c, mTOR and GLUT-2.

    Science.gov (United States)

    Sharawy, Maha H; El-Awady, Mohammed S; Megahed, Nirmeen; Gameil, Nariman M

    2016-01-01

    Insulin resistance is a serious health condition worldwide; however, its exact mechanisms are still unclear. This study investigates agmatine (AGM; an endogenous metabolite of L-arginine) effects on insulin resistance induced by high fructose diet (HFD) in rats and the possible involved mechanisms. Sprague Dawley rats were fed 60% HFD for 12 weeks, and AGM (10 mg/kg/day, orally) was given from week 9 to 12. AGM significantly reduced HFD-induced elevation in fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) index and liver glycogen content from 3.44-, 3.62- and 2.07- to 2.59-, 2.78- and 1.3-fold, respectively, compared to the control group, while it increased HFD-induced reduction in glucose tolerance. Additionally, AGM significantly decreased HFD-induced elevation in serum triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol levels from 3.18-, 2.97- and 4.75- to 1.25-, 1.25- and 1.07-fold, respectively, compared to control group. Conversely, AGM had no significant effect on HFD-induced changes in fasting glucose, glycosylated hemoglobin, insulin tolerance and high density lipoprotein cholesterol. Furthermore, AGM significantly reduced HFD-induced elevation in mRNA expression of glucose transporter type-2 (GLUT-2), mammalian target of rapamycin (mTOR) and sterol regulatory element-binding protein-1c (SREBP-1c) without affecting that of peroxisome proliferator-activated receptor-alpha (PPAR-α) in the liver. Additionally, AGM enhanced ACh-induced aortic relaxation and attenuated liver steatosis induced by HFD. In conclusion, AGM may have a therapeutic potential in insulin resistance through suppressing SREBP-1c, mTOR and GLUT-2 in liver.

  13. Long-term In Vitro Treatment of Human Glioblastoma Cells with Temozolomide Increases Resistance In Vivo through Up-regulation of GLUT Transporter and Aldo-Keto Reductase Enzyme AKR1C Expression

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    Benjamin Le Calvé

    2010-09-01

    Full Text Available Glioblastoma (GBM is the most frequent malignant glioma. Treatment of GBM patients is multimodal with maximum surgical resection, followed by concurrent radiation and chemotherapy with the alkylating drug temozolomide (TMZ. The present study aims to identify genes implicated in the acquired resistance of two human GBM cells of astrocytic origin, T98G and U373, to TMZ. Resistance to TMZ was induced by culturing these cells in vitro for months with incremental TMZ concentrations up to 1 mM. Only partial resistance to TMZ has been achieved and was demonstrated in vivo in immunocompromised mice bearing orthotopic U373 and T98G xenografts. Our data show that long-term treatment of human astroglioma cells with TMZ induces increased expression of facilitative glucose transporter/solute carrier GLUT/SLC2A family members, mainly GLUT-3, and of the AKR1C family of proteins. The latter proteins are phase 1 drug-metabolizing enzymes involved in the maintenance of steroid homeostasis, prostaglandin metabolism, and metabolic activation of polycyclic aromatic hydrocarbons. GLUT-3 has been previously suggested to exert roles in GBM neovascularization processes, and TMZ was found to exert antiangiogenic effects in experimental gliomas. AKR1C1 was previously shown to be associated with oncogenic potential, with proproliferative effects similar to AKR1C3 in the latter case. Both AKR1C1 and AKR1C2 proteins are involved in cancer pro-proliferative cell chemoresistance. Selective targeting of GLUT-3 in GBM and/or AKR1C proteins (by means of jasmonates, for example could thus delay the acquisition of resistance to TMZ of astroglioma cells in the context of prolonged treatment with this drug.

  14. In vitro glucose uptake activity of Aegles marmelos and Syzygium cumini by activation of Glut-4, PI3 kinase and PPARgamma in L6 myotubes.

    Science.gov (United States)

    Anandharajan, R; Jaiganesh, S; Shankernarayanan, N P; Viswakarma, R A; Balakrishnan, A

    2006-06-01

    The purpose of the present study is to investigate the effect of methanolic extracts of Aegles marmelos and Syzygium cumini on a battery of targets glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPARgamma) and phosphatidylinositol 3' kinase (PI3 kinase) involved in glucose transport. A. marmelos and S. cumini are anti-diabetic medicinal plants being used in Indian traditional medicine. Different solvent extracts extracted sequentially were analysed for glucose uptake activity at each step and methanol extracts were found to be significantly active at 100ng/ml dose comparable with insulin and rosiglitazone. Elevation of Glut-4, PPARgamma and PI3 kinase by A. marmelos and S. cumini in association with glucose transport supported the up-regulation of glucose uptake. The inhibitory effect of cycloheximide on A. marmelos- and S. cumini-mediated glucose uptake suggested that new protein synthesis is required for the elevated glucose transport. Current observation concludes that methanolic extracts of A. marmelos and S. cumini activate glucose transport in a PI3 kinase-dependent fashion.

  15. miR-95, -548am and -1246 expression in placenta tissue of gestational diabetes mellitus as well as their relationship with adipocytokines and glucose transporters

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    Li Tan

    2016-12-01

    Full Text Available Objective: To study the miR-95, -548am and -1246 expression in placenta tissue of gestational diabetes mellitus as well as their relationship with adipocytokines and glucose transporters (GLUTs. Methods: A total og 45 pregnant women diagnosed with gestational diabetes mellitus in obstetrics department of our hospital between May 2012 and December 2015 during obstetric were selected as the GDM group of the study, 40 healthy pregnant women who received antenatal care and gave birth during the same period were selected as the control group of the study. Serum was collected at 36 weeks of gestation to determine the content of glucolipid metabolism indexes and adipocytokines, and placenta tissue was collected after childbirth to determine the expression of miRNAs and GLUTs. Results: miR-95 and -548am expression levels in placenta tissue of GDM group were significantly higher than those of control group while miR-1246 expression level was significantly lower than that of control group; serum TC, TG, FBG, FINS, leptin, resistin and RBP4 content as well as HOMAIR level of GDM group were significantly higher than those of control group, positively correlated with miR-95 and -548am expression levels, and negatively correlated with miR- 1246 expression level; serum adiponectin and visfatin content as well as HOMA-ISI level were significantly lower than those of control group, negatively correlated with miR-95 and -548am expression levels, and positively correlated with miR-1246 expression level; GLUT1, GLUT3 and GLUT4 expression levels in placenta tissue of GDM group were significantly lower than those of control group, negatively correlated with miR-95 and -548am expression levels, and positively correlated with miR-1246 expression level. Conclusions: Abnormally expressed miR-95, -548am and -1246 in placenta tissue of gestational diabetes mellitus can target and adjust the expression of adipocytokines and glucose transporters, and thus result in maternal

  16. The Endocannabinoid System Affects Myocardial Glucose Metabolism in the DOCA-Salt Model of Hypertension

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    Agnieszka Polak

    2018-03-01

    Full Text Available Background/Aims: Recent interest in the use of cannabinoids as therapeutic agents has revealed the involvement of the endogenous cannabinoid system (ECS in the regulation of the cardiovascular system in hypertension. Abnormalities in glucose metabolism and insulin action are commonly detected in hypertensive animals. Thus, potential antihypertensive drugs should be investigated with respect to modulation of glucose homeostasis. Therefore, the aim of the present study was to evaluate the effects of the ECS activation after chronic fatty acid amide hydrolase inhibitor (URB597 administration on plasma glucose and insulin concentrations as well as parameters of myocardial glucose metabolism in the deoxycorticosterone acetate (DOCA-salt hypertensive rats, an animal model of secondary hypertension. Methods: Hypertension was induced by DOCA (25mg/kg injections and addition of 1% NaCl in the drinking water for six weeks. Chronic activation of the ECS was performed by URB597 (1mg/kg injections for two weeks. We examined fasting plasma levels of insulin (ELISA, glucose and intramyocardial glycogen (colorimetric method. Expressions of glucose transporters (GLUT1, 4 and selected proteins engaged in GLUT translocation as well as glucose metabolism were determined using Western blotting. Results: Hypertension induced hypoinsulinemia with concomitant lack of significant changes in glycemia, reduced intramyocardial glycogen content and increased pyruvate dehydrogenase (PDH expression in the cardiac muscle. Importantly, chronic URB597 administration in the hypertensive rats increased insulin concentration, elevated plasmalemmal GLUT1 and GLUT4 expression and concomitantly improved myocardial glycogen storage. Conclusion: Chronic administration of fatty acid amide hydrolase (FAAH inhibitor has potential protective properties on myocardial glucose metabolism in hypertension.

  17. Glucose transporters are expressed in taste receptor cells.

    Science.gov (United States)

    Merigo, Flavia; Benati, Donatella; Cristofoletti, Mirko; Osculati, Francesco; Sbarbati, Andrea

    2011-08-01

    In the intestine, changes of sugar concentration generated in the lumen during digestion induce adaptive responses of glucose transporters in the epithelium. A close matching between the intestinal expression of glucose transporters and the composition and amount of the diet has been provided by several experiments. Functional evidence has demonstrated that the regulation of glucose transporters into enterocytes is induced by the sensing of sugar of the enteroendocrine cells through activation of sweet taste receptors (T1R2 and T1R3) and their associated elements of G-protein-linked signaling pathways (e.g. α-gustducin, phospholipase C β type 2 and transient receptor potential channel M5), which are signaling molecules also involved in the perception of sweet substances in the taste receptor cells (TRCs) of the tongue. Considering this phenotypical similarity between the intestinal cells and TRCs, we evaluated whether the TRCs themselves possess proteins of the glucose transport mechanism. Therefore, we investigated the expression of the typical intestinal glucose transporters (i.e. GLUT2, GLUT5 and SGLT1) in rat circumvallate papillae, using immunohistochemistry, double-labeling immunofluorescence, immunoelectron microscopy and reverse transcriptase-polymerase chain reaction analysis. The results showed that GLUT2, GLUT5 and SGLT1 are expressed in TRCs; their immunoreactivity was also observed in cells that displayed staining for α-gustducin and T1R3 receptor. The immunoelectron microscopic results confirmed that GLUT2, GLUT5 and SGLT1 were predominantly expressed in cells with ultrastructural characteristics of chemoreceptor cells. The presence of glucose transporters in TRCs adds a further link between chemosensory information and cellular responses to sweet stimuli that may have important roles in glucose homeostasis, contributing to a better understanding of the pathways implicated in glucose metabolism. © 2011 The Authors. Journal of Anatomy © 2011

  18. Dysregulated hepatic expression of glucose transporters in chronic disease: contribution of semicarbazide-sensitive amine oxidase to hepatic glucose uptake.

    Science.gov (United States)

    Karim, Sumera; Liaskou, Evaggelia; Fear, Janine; Garg, Abhilok; Reynolds, Gary; Claridge, Lee; Adams, David H; Newsome, Philip N; Lalor, Patricia F

    2014-12-15

    Insulin resistance is common in patients with chronic liver disease (CLD). Serum levels of soluble vascular adhesion protein-1 (VAP-1) are also increased in these patients. The amine oxidase activity of VAP-1 stimulates glucose uptake via translocation of transporters to the cell membrane in adipocytes and smooth muscle cells. We aimed to document human hepatocellular expression of glucose transporters (GLUTs) and to determine if VAP-1 activity influences receptor expression and hepatic glucose uptake. Quantitative PCR and immunocytochemistry were used to study human liver tissue and cultured cells. We also used tissue slices from humans and VAP-1-deficient mice to assay glucose uptake and measure hepatocellular responses to stimulation. We report upregulation of GLUT1, -3, -5, -6, -7, -8, -9, -10, -11, -12, and -13 in CLD. VAP-1 expression and enzyme activity increased in disease, and provision of substrate to hepatic VAP-1 drives hepatic glucose uptake. This effect was sensitive to inhibition of VAP-1 and could be recapitulated by H2O2. VAP-1 activity also altered expression and subcellular localization of GLUT2, -4, -9, -10, and -13. Therefore, we show, for the first time, alterations in hepatocellular expression of glucose and fructose transporters in CLD and provide evidence that the semicarbazide-sensitive amine oxidase activity of VAP-1 modifies hepatic glucose homeostasis and may contribute to patterns of GLUT expression in chronic disease. Copyright © 2014 the American Physiological Society.

  19. Enigma interacts with adaptor protein with PH and SH2 domains to control insulin-induced actin cytoskeleton remodeling and glucose transporter 4 translocation.

    Science.gov (United States)

    Barrès, Romain; Grémeaux, Thierry; Gual, Philippe; Gonzalez, Teresa; Gugenheim, Jean; Tran, Albert; Le Marchand-Brustel, Yannick; Tanti, Jean-François

    2006-11-01

    APS (adaptor protein with PH and SH2 domains) initiates a phosphatidylinositol 3-kinase-independent pathway involved in insulin-stimulated glucose transport. We recently identified Enigma, a PDZ and LIM domain-containing protein, as a partner of APS and showed that APS-Enigma complex plays a critical role in actin cytoskeleton organization in fibroblastic cells. Because actin rearrangement is important for insulin-induced glucose transporter 4 (Glut 4) translocation, we studied the potential involvement of Enigma in insulin-induced glucose transport in 3T3-L1 adipocytes. Enigma mRNA was expressed in differentiated adipocytes and APS and Enigma were colocalized with cortical actin. Expression of an APS mutant unable to bind Enigma increased the insulin-induced Glut 4 translocation to the plasma membrane. By contrast, overexpression of Enigma inhibited insulin-stimulated glucose transport and Glut 4 translocation without alterations in proximal insulin signaling. This inhibitory effect was prevented with the deletion of the LIM domains of Enigma. Using time-lapse fluorescent microscopy of green fluorescent protein-actin, we demonstrated that the overexpression of Enigma altered insulin-induced actin rearrangements, whereas the expression of Enigma without its LIM domains was without effect. A physiological link between increased expression of Enigma and an alteration in insulin-induced glucose uptake was suggested by the increase in Enigma mRNA expression in adipose tissue of diabetic obese patients. Taken together, these data strongly suggest that the interaction between APS and Enigma is involved in insulin-induced Glut 4 translocation by regulating cortical actin remodeling and raise the possibility that modification of APS/Enigma ratio could participate in the alteration of insulin-induced glucose uptake in adipose tissue.

  20. Low birthweight is associated with specific changes in muscle insulin-signalling protein expression

    DEFF Research Database (Denmark)

    Ozanne, SE; Jensen, CB; Tingey, KJ

    2005-01-01

    muscle in a human cohort and a rat model. METHODS: We recruited 20 young men with low birthweight (mean birthweight 2702+/-202 g) and 20 age-matched control subjects (mean birthweight 3801+/-99 g). Biopsies were obtained from the vastus lateralis muscle and protein expression of selected insulin......-signalling proteins was determined. Rats used for this study were male offspring born to dams fed a standard (20%) protein diet or a low (8%) protein diet during pregnancy and lactation. Protein expression was determined in soleus muscle from adult offspring. RESULTS: Low-birthweight subjects showed reduced muscle...... expression of protein kinase C (PKC)zeta, p85alpha, p110beta and GLUT4. PKCzeta, GLUT4 and p85 were also reduced in the muscle of rats fed a low-protein diet. Other proteins studied were unchanged in low-birthweight humans and in rats fed a low-protein diet when compared with control groups. CONCLUSIONS...

  1. GLUT2 and the incretin receptors are involved in glucose-induced incretin secretion

    DEFF Research Database (Denmark)

    Cani, Patrice D; Holst, Jens Juul; Drucker, Daniel J

    2007-01-01

    to those described for beta-cells, brain and hepatoportal sensors. We determined the role of GLUT2, GLP-1 or GIP receptors in glucose-induced incretins secretion, in the corresponding knockout mice. GLP-1 secretion was reduced in all mutant mice, while GIP secretion did not require GLUT2. Intestinal GLP-1...... content was reduced only in GIP and GLUT2 receptors knockout mice suggesting that this impairment could contribute to the phenotype. Intestinal GIP content was similar in all mice studied. Furthermore, the impaired incretins secretion was associated with a reduced glucose-stimulated insulin secretion...

  2. Effect of telmisartan on the expression of adiponectin receptors and nicotinamide adenine dinucleotide phosphate oxidase in the heart and aorta in type 2 diabetic rats

    Directory of Open Access Journals (Sweden)

    Guo Zhixin

    2012-08-01

    Full Text Available Abstract Background Diabetic cardiovascular disease is associated with decreased adiponectin and increased oxidative stress. This study investigated the effect of telmisartan on the expression of adiponectin receptor 2 (adipoR2 and nicotinamide adenine dinucleotide phosphate (NADPH oxidase subunits in the heart and the expression of adiponectin receptor 1 (adipoR1 in aorta in type 2 diabetic rats. Methods Type 2 diabetes was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin (STZ. Heart function, adipoR2, p22phox, NOX4, glucose transporter 4(GLUT4, monocyte chemoattractant protein-1(MCP-1 and connective tissue growth factor (CTGFin the heart, and adipoR1, MCP-1 and nuclear factor kappa B (NF-κB in aorta were analyzed in controls and diabetic rats treated with or without telmisartan (5mg/kg/d by gavage for 12 weeks. Results Heart function, plasma and myocardial adiponectin levels, the expression of myocardial adipoR2 and GLUT4 were significantly decreased in diabetic rats (P Conclusions Our results suggest that telmisartan upregulates the expression of myocardial adiponectin, its receptor 2 and GLUT4. Simultaneously, it downregulates the expression of myocardial p22phox, NOX4, MCP-1, and CTGF, contributing so to the improvement of heart function in diabetic rats. Telmisartan also induces a protective role on the vascular system by upregulating the expression of adipoR1 and downregulating the expression of MCP-1 and NF-κB in the abdominal aorta in diabetic rats.

  3. Oral tongue cancer gene expression profiling: Identification of novel potential prognosticators by oligonucleotide microarray analysis

    International Nuclear Information System (INIS)

    Estilo, Cherry L; Boyle, Jay O; Kraus, Dennis H; Patel, Snehal; Shaha, Ashok R; Wong, Richard J; Huryn, Joseph M; Shah, Jatin P; Singh, Bhuvanesh; O-charoenrat, Pornchai; Talbot, Simon; Socci, Nicholas D; Carlson, Diane L; Ghossein, Ronald; Williams, Tijaana; Yonekawa, Yoshihiro; Ramanathan, Yegnanarayana

    2009-01-01

    The present study is aimed at identifying potential candidate genes as prognostic markers in human oral tongue squamous cell carcinoma (SCC) by large scale gene expression profiling. The gene expression profile of patients (n=37) with oral tongue SCC were analyzed using Affymetrix HG-U95Av2 high-density oligonucleotide arrays. Patients (n=20) from which there were available tumor and matched normal mucosa were grouped into stage (early vs. late) and nodal disease (node positive vs. node negative) subgroups and genes differentially expressed in tumor vs. normal and between the subgroups were identified. Three genes, GLUT3, HSAL2, and PACE4, were selected for their potential biological significance in a larger cohort of 49 patients via quantitative real-time RT-PCR. Hierarchical clustering analyses failed to show significant segregation of patients. In patients (n=20) with available tumor and matched normal mucosa, 77 genes were found to be differentially expressed (P< 0.05) in the tongue tumor samples compared to their matched normal controls. Among the 45 over-expressed genes, MMP-1 encoding interstitial collagenase showed the highest level of increase (average: 34.18 folds). Using the criterion of two-fold or greater as overexpression, 30.6%, 24.5% and 26.5% of patients showed high levels of GLUT3, HSAL2 and PACE4, respectively. Univariate analyses demonstrated that GLUT3 over-expression correlated with depth of invasion (P<0.0001), tumor size (P=0.024), pathological stage (P=0.009) and recurrence (P=0.038). HSAL2 was positively associated with depth of invasion (P=0.015) and advanced T stage (P=0.047). In survival studies, only GLUT3 showed a prognostic value with disease-free (P=0.049), relapse-free (P=0.002) and overall survival (P=0.003). PACE4 mRNA expression failed to show correlation with any of the relevant parameters. The characterization of genes identified to be significant predictors of prognosis by oligonucleotide microarray and further validation by

  4. Deletion of GLUT1 and GLUT3 Reveals Multiple Roles for Glucose Metabolism in Platelet and Megakaryocyte Function

    Directory of Open Access Journals (Sweden)

    Trevor P. Fidler

    2017-07-01

    Full Text Available Anucleate platelets circulate in the blood to facilitate thrombosis and diverse immune functions. Platelet activation leading to clot formation correlates with increased glycogenolysis, glucose uptake, glucose oxidation, and lactic acid production. Simultaneous deletion of glucose transporter (GLUT 1 and GLUT3 (double knockout [DKO] specifically in platelets completely abolished glucose uptake. In DKO platelets, mitochondrial oxidative metabolism of non-glycolytic substrates, such as glutamate, increased. Thrombosis and platelet activation were decreased through impairment at multiple activation nodes, including Ca2+ signaling, degranulation, and integrin activation. DKO mice developed thrombocytopenia, secondary to impaired pro-platelet formation from megakaryocytes, and increased platelet clearance resulting from cytosolic calcium overload and calpain activation. Systemic treatment with oligomycin, inhibiting mitochondrial metabolism, induced rapid clearance of platelets, with circulating counts dropping to zero in DKO mice, but not wild-type mice, demonstrating an essential role for energy metabolism in platelet viability. Thus, substrate metabolism is essential for platelet production, activation, and survival.

  5. Caveolin-1 and glucose transporter 4 involved in the regulation of glucose-deprivation stress in PC12 cells.

    Science.gov (United States)

    Zhang, Qi-Qi; Huang, Liang; Han, Chao; Guan, Xin; Wang, Ya-Jun; Liu, Jing; Wan, Jing-Hua; Zou, Wei

    2015-08-25

    Recent evidence suggests that caveolin-1 (Cav-1), the major protein constituent of caveolae, plays a prominent role in neuronal nutritional availability with cellular fate regulation besides in several cellular processes such as cholesterol homeostasis, regulation of signal transduction, integrin signaling and cell growth. Here, we aimed to investigate the function of Cav-1 and glucose transporter 4 (GLUT4) upon glucose deprivation (GD) in PC12 cells. The results demonstrated firstly that both Cav-1 and GLUT4 were up-regulated by glucose withdrawal in PC12 cells by using Western blot and laser confocal technology. Also, we found that the cell death rate, mitochondrial membrane potential (MMP) and intracellular free Ca(2+) concentration ([Ca(2+)]i) were also respectively changed followed the GD stress tested by CCK8 and flow cytometry. After knocking down of Cav-1 in the cells by siRNA, the level of [Ca(2+)]i was increased, and MMP was reduced further in GD-treated PC12 cells. Knockdown of Cav-1 or methylated-β-Cyclodextrin (M-β-CD) treatment inhibited the expression of GLUT4 protein upon GD. Additionally, we found that GLUT4 could translocate from cytoplasm to cell membrane upon GD. These findings might suggest a neuroprotective role for Cav-1, through coordination of GLUT4 in GD.

  6. Biochemical phenotyping unravels novel metabolic abnormalities and potential biomarkers associated with treatment of GLUT1 deficiency with ketogenic diet.

    Science.gov (United States)

    Cappuccio, Gerarda; Pinelli, Michele; Alagia, Marianna; Donti, Taraka; Day-Salvatore, Debra-Lynn; Veggiotti, Pierangelo; De Giorgis, Valentina; Lunghi, Simona; Vari, Maria Stella; Striano, Pasquale; Brunetti-Pierri, Nicola; Kennedy, Adam D; Elsea, Sarah H

    2017-01-01

    Global metabolomic profiling offers novel opportunities for the discovery of biomarkers and for the elucidation of pathogenic mechanisms that might lead to the development of novel therapies. GLUT1 deficiency syndrome (GLUT1-DS) is an inborn error of metabolism due to reduced function of glucose transporter type 1. Clinical presentation of GLUT1-DS is heterogeneous and the disorder mirrors patients with epilepsy, movement disorders, or any paroxysmal events or unexplained neurological manifestation triggered by exercise or fasting. The diagnostic biochemical hallmark of the disease is a reduced cerebrospinal fluid (CSF)/blood glucose ratio and the only available treatment is ketogenic diet. This study aimed at advancing our understanding of the biochemical perturbations in GLUT1-DS pathogenesis through biochemical phenotyping and the treatment of GLUT1-DS with a ketogenic diet. Metabolomic analysis of three CSF samples from GLUT1-DS patients not on ketogenic diet was feasible inasmuch as CSF sampling was used for diagnosis before to start with ketogenic diet. The analysis of plasma and urine samples obtained from GLUT1-DS patients treated with a ketogenic diet showed alterations in lipid and amino acid profiles. While subtle, these were consistent findings across the patients with GLUT1-DS on ketogenic diet, suggesting impacts on mitochondrial physiology. Moreover, low levels of free carnitine were present suggesting its consumption in GLUT1-DS on ketogenic diet. 3-hydroxybutyrate, 3-hydroxybutyrylcarnitine, 3-methyladipate, and N-acetylglycine were identified as potential biomarkers of GLUT1-DS on ketogenic diet. This is the first study to identify CSF, plasma, and urine metabolites associated with GLUT1-DS, as well as biochemical changes impacted by a ketogenic diet. Potential biomarkers and metabolic insights deserve further investigation.

  7. A Glimpse of Membrane Transport through Structures-Advances in the Structural Biology of the GLUT Glucose Transporters.

    Science.gov (United States)

    Yan, Nieng

    2017-08-18

    The cellular uptake of glucose is an essential physiological process, and movement of glucose across biological membranes requires specialized transporters. The major facilitator superfamily glucose transporters GLUTs, encoded by the SLC2A genes, have been a paradigm for functional, mechanistic, and structural understanding of solute transport in the past century. This review starts with a glimpse into the structural biology of membrane proteins and particularly membrane transport proteins, enumerating the landmark structures in the past 25years. The recent breakthrough in the structural elucidation of GLUTs is then elaborated following a brief overview of the research history of these archetypal transporters, their functional specificity, and physiological and pathophysiological significances. Structures of GLUT1, GLUT3, and GLUT5 in distinct transport and/or ligand-binding states reveal detailed mechanisms of the alternating access transport cycle and substrate recognition, and thus illuminate a path by which structure-based drug design may be applied to help discover novel therapeutics against several debilitating human diseases associated with GLUT malfunction and/or misregulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Expression of digestive enzymes and nutrient transporters in Eimeria-challenged broilers.

    Science.gov (United States)

    Su, S; Miska, K B; Fetterer, R H; Jenkins, M C; Wong, E A

    2015-03-01

    Avian coccidiosis is a disease caused by the intestinal protozoa Eimeria. The site of invasion and lesions in the intestine is species-specific, for example E. acervulina affects the duodenum, E. maxima the jejunum, and E. tenella the ceca. Lesions in the intestinal mucosa cause reduced feed efficiency and body weight gain. The growth reduction may be due to changes in expression of digestive enzymes and nutrient transporters in the intestine. The objective of this study was to compare the expression of digestive enzymes, nutrient transporters and an antimicrobial peptide in broilers challenged with either E. acervulina, E. maxima or E. tenella. The genes examined included digestive enzymes (APN and SI), peptide and amino acid transporters (PepT1, ASCT1, b(0,+)AT/rBAT, B(0)AT, CAT1, CAT2, EAAT3, LAT1, y(+)LAT1 and y(+)LAT2), sugar transporters (GLUT1, GLUT2, GLUT5 and SGLT1), zinc transporter (ZnT1) and an antimicrobial peptide (LEAP2). Duodenum, jejunum, ileum and ceca were collected 7 days post challenge. E. acervulina challenge resulted in downregulation of various nutrient transporters or LEAP2 in the duodenum and ceca, but not the jejunum or ileum. E. maxima challenge produced both downregulation and upregulation of nutrient transporters and LEAP2 in all three segments of the small intestine and ceca. E. tenella challenge resulted in the downregulation and upregulation of nutrient transporters and LEAP2 in the jejunum, ileum and ceca, but not the duodenum. At the respective target tissue, E. acervulina, E. maxima and E. tenella infection caused common downregulation of APN, b(0,+)AT, rBAT, EAAT3, SI, GLUT2, GLUT5, ZnT1 and LEAP2. The downregulation of nutrient transporters would result in a decrease in the efficiency of protein and polysaccharide digestion and uptake, which may partially explain the weight loss. The downregulation of nutrient transporters may also be a cellular response to reduced expression of the host defense protein LEAP2, which would

  9. Dehydroeburicoic Acid from Antrodia camphorata Prevents the Diabetic and Dyslipidemic State via Modulation of Glucose Transporter 4, Peroxisome Proliferator-Activated Receptor α Expression and AMP-Activated Protein Kinase Phosphorylation in High-Fat-Fed Mice

    Directory of Open Access Journals (Sweden)

    Yueh-Hsiung Kuo

    2016-06-01

    Full Text Available This study investigated the potential effects of dehydroeburicoic acid (TT, a triterpenoid compound from Antrodia camphorata, in vitro and examined the effects and mechanisms of TT on glucose and lipid homeostasis in high-fat-diet (HFD-fed mice. The in vitro study examined the effects of a MeOH crude extract (CruE of A. camphorata and Antcin K (AnK; the main constituent of fruiting body of this mushroom on membrane glucose transporter 4 (GLUT4 and phospho-Akt in C2C12 myoblasts cells. The in vitro study demonstrated that treatment with CruE, AnK and TT increased the membrane levels of glucose transporter 4 (GLUT4 and phospho-Akt at different concentrations. The animal experiments were performed for 12 weeks. Diabetic mice were randomly divided into six groups after 8 weeks of HFD-induction and treated with daily oral gavage doses of TT (at three dose levels, fenofibrate (Feno (at 0.25 g/kg body weight, metformin (Metf (at 0.3 g/kg body weight or vehicle for another 4 weeks while on an HFD diet. HFD-fed mice exhibited increased blood glucose levels. TT treatment dramatically lowered blood glucose levels by 34.2%~43.4%, which was comparable to the antidiabetic agent-Metf (36.5%. TT-treated mice reduced the HFD-induced hyperglycemia, hypertriglyceridemia, hyperinsulinemia, hyperleptinemia, and hypercholesterolemia. Membrane levels of GLUT4 were significantly higher in CruE-treated groups in vitro. Skeletal muscle membrane levels of GLUT4 were significantly higher in TT-treated mice. These groups of mice also displayed lower mRNA levels of glucose-6-phosphatase (G6 Pase, an inhibitor of hepatic glucose production. The combination of these agents produced a net hypoglycemic effect in TT-treated mice. TT treatment enhanced the expressions of hepatic and skeletal muscle AMP-activated protein kinase (AMPK phosphorylation in mice. TT-treated mice exhibited enhanced expression of hepatic fatty acid oxidation enzymes, including peroxisome proliferator

  10. Elucidation of the glucose transport pathway in glucose transporter 4 via steered molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Aswathy Sheena

    Full Text Available BACKGROUND: GLUT4 is a predominant insulin regulated glucose transporter expressed in major glucose disposal tissues such as adipocytes and muscles. Under the unstimulated state, GLUT4 resides within intracellular vesicles. Various stimuli such as insulin translocate this protein to the plasma membrane for glucose transport. In the absence of a crystal structure for GLUT4, very little is known about the mechanism of glucose transport by this protein. Earlier we proposed a homology model for GLUT4 and performed a conventional molecular dynamics study revealing the conformational rearrangements during glucose and ATP binding. However, this study could not explain the transport of glucose through the permeation tunnel. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the molecular mechanism of glucose transport and its energetic, a steered molecular dynamics study (SMD was used. Glucose was pulled from the extracellular end of GLUT4 to the cytoplasm along the pathway using constant velocity pulling method. We identified several key residues within the tunnel that interact directly with either the backbone ring or the hydroxyl groups of glucose. A rotation of glucose molecule was seen near the sugar binding site facilitating the sugar recognition process at the QLS binding site. CONCLUSIONS/SIGNIFICANCE: This study proposes a possible glucose transport pathway and aids the identification of several residues that make direct interactions with glucose during glucose transport. Mutational studies are required to further validate the observation made in this study.

  11. Endurance exercise induces mRNA expression of oxidative enzymes in human skeletal muscle late in recovery

    DEFF Research Database (Denmark)

    Leick, Lotte; Plomgaard, Peter S.; Grønløkke, L.

    2010-01-01

    exercise. To test the hypothesis that mRNA expression of many oxidative enzymes is up-regulated late in recovery (10-24 h) after exercise, male subjects (n=8) performed a 90-min cycling exercise (70% VO(2-max)), with muscle biopsies obtained before exercise (pre), and after 10, 18 and 24 h of recovery....... The mRNA expression of carnitine-palmitoyltransferase (CPT)I, CD36, 3-hydroxyacyl-CoA-dehydrogenase (HAD), cytochrome (Cyt)c, aminolevulinate-delta-synthase (ALAS)1 and GLUT4 was 100-200% higher at 10-24 h of recovery from exercise than in a control trial. Exercise induced a 100-300% increase...... in peroxisome proliferator-activated receptor gamma co-activator (PGC)-1alpha, citrate synthase (CS), CPTI, CD36, HAD and ALAS1 mRNA contents at 10-24 h of recovery relative to before exercise. No protein changes were detected in Cytc, ALAS1 or GLUT4. This shows that mRNA expression of several training...

  12. Glucose Transporter 1 Expression in Odontogenic Keratocyst, Dentigerous Cyst, and Ameloblastoma: An Immunohistochemical Study.

    Science.gov (United States)

    Bandyopadhyay, Alokenath; Panda, Abikshyeet; Behura, Shyam S; Ramachandra, Sujatha; Dash, Kailash C; Mishra, Pallavi

    2017-05-01

    An array of odontogenic lesions manifest in the maxillofacial region with variable presentations. The biological behavior of lesions, such as odontogenic keratocyst (OKC), dentigerous cyst (DC), and ameloblastoma (AM) always invite debate. Glucose transporter 1 (GLUT-1) is proven to be an indicator of metabolic behavior of several benign and malignant neoplasms. The purpose of this study was to evaluate the expression of GLUT-1 in OKC, DC, and AM to understand their metabolic behavior. Immunohistochemical expression of GLUT-1 was evaluated in each of the 15 cases of OKC, DC, and AM. The number of labeled cells, staining intensity, and membrane or cytoplasmic expressions were the parameters assessed and analyzed using chi-square test. All cases showed positive GLUT-1 expression: 86.6% OKC showed more than 50% labeled cells followed by DC (40%) and AM (26.5%); 53.3% OKC showed strong intensity in comparison to AM, which showed weak intensity in 53.3% cases; 86.6% of OKCs showed both membrane and cytoplasmic expression followed by DC (40%) and AM (26.6%), whereas 73.3% of AM showed only membrane expression followed by DC (60%) and OKC (13.3%). Odontogenic keratocyst was found out to be more metabolically active followed by DC and AM.

  13. Caffeine inhibition of GLUT1 is dependent on the activation state of the transporter.

    Science.gov (United States)

    Gunnink, Leesha K; Busscher, Brianna M; Wodarek, Jeremy A; Rosette, Kylee A; Strohbehn, Lauren E; Looyenga, Brendan D; Louters, Larry L

    2017-06-01

    Caffeine has been shown to be a robust uncompetitive inhibitor of glucose uptake in erythrocytes. It preferentially binds to the nucleotide-binding site on GLUT1 in its tetrameric form and mimics the inhibitory action of ATP. Here we demonstrate that caffeine is also a dose-dependent, uncompetitive inhibitor of 2-deoxyglucose (2DG) uptake in L929 fibroblasts. The inhibitory effect on 2DG uptake in these cells was reversible with a rapid onset and was additive to the competitive inhibitory effects of glucose itself, confirming that caffeine does not interfere with glucose binding. We also report for the first time that caffeine inhibition was additive to inhibition by curcumin, suggesting distinct binding sites for curcumin and caffeine. In contrast, caffeine inhibition was not additive to that of cytochalasin B, consistent with previous data that reported that these two inhibitors have overlapping binding sites. More importantly, we show that the magnitude of maximal caffeine inhibition in L929 cells is much lower than in erythrocytes (35% compared to 90%). Two epithelial cell lines, HCLE and HK2, have both higher concentrations of GLUT1 and increased basal 2DG uptake (3-4 fold) compared to L929 cells, and subsequently display greater maximal inhibition by caffeine (66-70%). Interestingly, activation of 2DG uptake (3-fold) in L929 cells by glucose deprivation shifted the responsiveness of these cells to caffeine inhibition (35%-70%) without a change in total GLUT1 concentration. These data indicate that the inhibition of caffeine is dependent on the activity state of GLUT1, not merely on the concentration. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Cinnamon extract regulates glucose transporter and insulin-signaling gene expression in mouse adipocytes.

    Science.gov (United States)

    Cao, Heping; Graves, Donald J; Anderson, Richard A

    2010-11-01

    Cinnamon extracts (CE) are reported to have beneficial effects on people with normal and impaired glucose tolerance, the metabolic syndrome, type 2 diabetes, and insulin resistance. However, clinical results are controversial. Molecular characterization of CE effects is limited. This study investigated the effects of CE on gene expression in cultured mouse adipocytes. Water-soluble CE was prepared from ground cinnamon (Cinnamomum burmannii). Quantitative real-time PCR was used to investigate CE effects on the expression of genes coding for adipokines, glucose transporter (GLUT) family, and insulin-signaling components in mouse 3T3-L1 adipocytes. CE (100 μg/ml) increased GLUT1 mRNA levels 1.91±0.15, 4.39±0.78, and 6.98±2.18-fold of the control after 2-, 4-, and 16-h treatments, respectively. CE decreased the expression of further genes encoding insulin-signaling pathway proteins including GSK3B, IGF1R, IGF2R, and PIK3R1. This study indicates that CE regulates the expression of multiple genes in adipocytes and this regulation could contribute to the potential health benefits of CE. Published by Elsevier GmbH.

  15. Expression of insulin signalling components in the sensory epithelium of the human saccule

    DEFF Research Database (Denmark)

    Degerman, Eva; Rauch, Uwe; Lindberg, Sven

    2013-01-01

    signalling components in the inner ear is sparce. Our immunohistochemistry approach has shown that the insulin receptor, insulin receptor substrate 1 (IRS1), protein kinase B (PKB) and insulin-sensitive glucose transporter (GLUT4) are expressed in the sensory epithelium of the human saccule, which also...

  16. GLUT1-mediated selective tumor targeting with fluorine containing platinum(II) glycoconjugates.

    Science.gov (United States)

    Liu, Ran; Fu, Zheng; Zhao, Meng; Gao, Xiangqian; Li, Hong; Mi, Qian; Liu, Pengxing; Yang, Jinna; Yao, Zhi; Gao, Qingzhi

    2017-06-13

    Increased glycolysis and overexpression of glucose transporters (GLUTs) are physiological characteristics of human malignancies. Based on the so-called Warburg effect, 18flurodeoxyglucose-positron emission tomography (FDG-PET) has successfully developed as clinical modality for the diagnosis and staging of many cancers. To leverage this glucose transporter mediated metabolic disparity between normal and malignant cells, in the current report, we focus on the fluorine substituted series of glucose, mannose and galactose-conjugated (trans-R,R-cyclohexane-1,2-diamine)-2-flouromalonato-platinum(II) complexes for a comprehensive evaluation on their selective tumor targeting. Besides highly improved water solubility, these sugar-conjugates presented improved cytotoxicity than oxaliplatin in glucose tranporters (GLUTs) overexpressing cancer cell lines and exhibited no cross-resistance to cisplatin. For the highly water soluble glucose-conjugated complex (5a), two novel in vivo assessments were conducted and the results revealed that 5a was more efficacious at a lower equitoxic dose (70% MTD) than oxaliplatin (100% MTD) in HT29 xenograft model, and it was significantly more potent than oxaliplatin in leukemia-bearing DBA/2 mice as well even at equimolar dose levels (18% vs 90% MTD). GLUT inhibitor mediated cell viability analysis, GLUT1 knockdown cell line-based cytotoxicity evaluation, and platinum accumulation study demonstrated that the cellular uptake of the sugar-conjugates was regulated by GLUT1. The higher intrinsic DNA reactivity of the sugar-conjugates was confirmed by kinetic study of platinum(II)-guanosine adduct formation. The mechanistic origin of the antitumor effect of the fluorine complexes was found to be forming the bifunctional Pt-guanine-guanine (Pt-GG) intrastrand cross-links with DNA. The results provide a rationale for Warburg effect targeted anticancer drug design.

  17. 2-(4-Methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-D-pyranoside confers neuroprotection in cell and animal models of ischemic stroke through calpain1/PKA/CREB-mediated induction of neuronal glucose transporter 3

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shu; Cheng, Qiong; Li, Lu; Liu, Mei; Yang, Yumin; Ding, Fei, E-mail: dingfei@ntu.edu.cn

    2014-06-15

    Salidroside is proven to be a neuroprotective agent of natural origin, and its analog, 2-(4-Methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-D-pyranoside (named SalA-4 g), has been synthesized in our lab. In this study, we showed that SalA-4 g promoted neuronal survival and inhibited neuronal apoptosis in primary hippocampal neurons exposed to oxygen and glucose deprivation (OGD) and in rats subjected to ischemia by transient middle cerebral artery occlusion (MCAO), respectively, and that SalA-4 g was more neuroprotective than salidroside. We further found that SalA-4 g elevated glucose uptake in OGD-injured primary hippocampal neurons and increased the expression and recruitment of glucose transporter 3 (GLUT3) in ischemic brain. Signaling analysis revealed that SalA-4 g triggered the phosphorylation of CREB, and increased the expression of PKA RII in primary hippocampal neurons exposed to OGD injury, while inhibition of PKA/CREB by H-89 alleviated the elevation in glucose uptake and GLUT3 expression, and blocked the protective effects of SalA-4 g. Moreover, SalA-4 g was noted to inhibit intracellular Ca{sup 2+} influx and calpain1 activation in OGD-injured primary hippocampal neurons. Our results suggest that SalA-4 g neuroprotection might be mediated by increased glucose uptake and elevated GLUT3 expression through calpain1/PKA/CREB pathway. - Highlights: • A salidroside (Sal) analog (SalA-4 g) is prepared to be more neuroprotective than Sal. • SalA-4 g protected hippocampal neurons from oxygen and glucose deprivation insult. • SalA-4 g reduced ischemic injury after transient middle cerebral artery occlusion in rats. • Neuroprotection of SalA-4 g was mediated by GLUT3 level via calpain/PKA/CREB pathway.

  18. 2-(4-Methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-D-pyranoside confers neuroprotection in cell and animal models of ischemic stroke through calpain1/PKA/CREB-mediated induction of neuronal glucose transporter 3

    International Nuclear Information System (INIS)

    Yu, Shu; Cheng, Qiong; Li, Lu; Liu, Mei; Yang, Yumin; Ding, Fei

    2014-01-01

    Salidroside is proven to be a neuroprotective agent of natural origin, and its analog, 2-(4-Methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-D-pyranoside (named SalA-4 g), has been synthesized in our lab. In this study, we showed that SalA-4 g promoted neuronal survival and inhibited neuronal apoptosis in primary hippocampal neurons exposed to oxygen and glucose deprivation (OGD) and in rats subjected to ischemia by transient middle cerebral artery occlusion (MCAO), respectively, and that SalA-4 g was more neuroprotective than salidroside. We further found that SalA-4 g elevated glucose uptake in OGD-injured primary hippocampal neurons and increased the expression and recruitment of glucose transporter 3 (GLUT3) in ischemic brain. Signaling analysis revealed that SalA-4 g triggered the phosphorylation of CREB, and increased the expression of PKA RII in primary hippocampal neurons exposed to OGD injury, while inhibition of PKA/CREB by H-89 alleviated the elevation in glucose uptake and GLUT3 expression, and blocked the protective effects of SalA-4 g. Moreover, SalA-4 g was noted to inhibit intracellular Ca 2+ influx and calpain1 activation in OGD-injured primary hippocampal neurons. Our results suggest that SalA-4 g neuroprotection might be mediated by increased glucose uptake and elevated GLUT3 expression through calpain1/PKA/CREB pathway. - Highlights: • A salidroside (Sal) analog (SalA-4 g) is prepared to be more neuroprotective than Sal. • SalA-4 g protected hippocampal neurons from oxygen and glucose deprivation insult. • SalA-4 g reduced ischemic injury after transient middle cerebral artery occlusion in rats. • Neuroprotection of SalA-4 g was mediated by GLUT3 level via calpain/PKA/CREB pathway

  19. CD4+CD25+ T cells expressing FoxP3 in Icelandic horses affected with insect bite hypersensitivity.

    Science.gov (United States)

    Hamza, Eman; Steinbach, Falko; Marti, Eliane

    2012-07-15

    Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis caused by bites of midges from the genus Culicoides. We have shown previously that peripheral blood mononuclear cells (PBMC) from IBH-affected horses produce higher levels of IL-4 and lower levels of IL-10 and TGF-β1 than those from healthy horses, suggesting that IBH is associated with a reduced regulatory immune response. FoxP3 is a crucial marker of regulatory T cells (Tregs). Here we have determined the proportion of CD4(+)CD25(+)FoxP3(+) T cells by flow cytometry in PBMC directly after isolation or after stimulation with Culicoides extract or a control antigen (Tetanus Toxoid). There were no differences between healthy and IBH horses either in the proportion of FoxP3(+)CD4(+)CD25(+) cells in freshly isolated PBMC or in the following stimulation with Tetanus Toxoid. However, upon stimulation of PBMC with the allergen, expression of FoxP3 by CD4(+)CD25(+high) and CD4(+)CD25(+dim) cells was significantly higher in healthy than in IBH horses. Addition of recombinant IL-4 to PBMC from healthy horses stimulated with the allergen significantly decreased the proportion of FoxP3 expressing cells within CD4(+)CD25(+high). These results suggest that IBH is associated with a decreased number of allergen-induced Tregs. This could be a consequence of the increased IL-4 production by PBMC of IBH-affected horses. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Nutritional status induces divergent variations of GLUT4 protein content, but not lipoprotein lipase activity, between adipose tissues and muscles in adult cattle.

    Science.gov (United States)

    Bonnet, Muriel; Faulconnier, Yannick; Hocquette, Jean-François; Bocquier, François; Leroux, Christine; Martin, Patrice; Chilliard, Yves

    2004-10-01

    Metabolic adaptations to variations in food supply are incompletely understood in ruminant animal adipose tissue (AT) and muscle. To explore this, we studied lipid metabolism and glucose transport potential in one internal and one external AT, as well as in one oxidative and one glycolytic muscle from control, 7 d underfed and 21 d refed adult cows. Refeeding increased (+79 to +307 %) the activities of enzymes involved in de novo lipogenesis (fatty acid synthase, malic enzyme, glucose-6-phosphate dehydrogenase) in perirenal and subcutaneous AT; underfeeding did not modify these variables. Underfeeding decreased the activities of lipoprotein lipase (LPL) in perirenal AT (-70 %) and cardiac muscle (-67 %), but did not modify the activities in subcutaneous AT and longissimus thoracis. Refeeding increased LPL activities in all tissues (+40 to +553 %) to levels comparable with (cardiac muscle) or greater than (AT, longissimus thoracis) those observed in control cows. Such variations in perirenal and cardiac muscle LPL activities did not result from variations in LPL mRNA levels, but suggest a post-transcriptional regulation of LPL in these nutritional conditions. Underfeeding did not modify GLUT4 contents in perirenal AT and muscles, while refeeding increased it only in perirenal AT (+250 %). Our present results contrast with previous results in rats, where LPL is regulated in opposite directions in AT and muscles, and GLUT4 is generally increased by fasting and decreased by refeeding in skeletal muscles. The present results highlight the bovine specificity of the response, which probably arises in part from peculiarities of ruminant animals for nutrient digestion and absorption.

  1. Complex analysis of urate transporters SLC2A9, SLC22A12 and functional characterization of non-synonymous allelic variants of GLUT9 in the Czech population: no evidence of effect on hyperuricemia and gout.

    Science.gov (United States)

    Hurba, Olha; Mancikova, Andrea; Krylov, Vladimir; Pavlikova, Marketa; Pavelka, Karel; Stibůrková, Blanka

    2014-01-01

    Using European descent Czech populations, we performed a study of SLC2A9 and SLC22A12 genes previously identified as being associated with serum uric acid concentrations and gout. This is the first study of the impact of non-synonymous allelic variants on the function of GLUT9 except for patients suffering from renal hypouricemia type 2. The cohort consisted of 250 individuals (150 controls, 54 nonspecific hyperuricemics and 46 primary gout and/or hyperuricemia subjects). We analyzed 13 exons of SLC2A9 (GLUT9 variant 1 and GLUT9 variant 2) and 10 exons of SLC22A12 by PCR amplification and sequenced directly. Allelic variants were prepared and their urate uptake and subcellular localization were studied by Xenopus oocytes expression system. The functional studies were analyzed using the non-parametric Wilcoxon and Kruskall-Wallis tests; the association study used the Fisher exact test and linear regression approach. We identified a total of 52 sequence variants (12 unpublished). Eight non-synonymous allelic variants were found only in SLC2A9: rs6820230, rs2276961, rs144196049, rs112404957, rs73225891, rs16890979, rs3733591 and rs2280205. None of these variants showed any significant difference in the expression of GLUT9 and in urate transport. In the association study, eight variants showed a possible association with hyperuricemia. However, seven of these were in introns and the one exon located variant, rs7932775, did not show a statistically significant association with serum uric acid concentration. Our results did not confirm any effect of SLC22A12 and SLC2A9 variants on serum uric acid concentration. Our complex approach using association analysis together with functional and immunohistochemical characterization of non-synonymous allelic variants did not show any influence on expression, subcellular localization and urate uptake of GLUT9.

  2. Beetle (Ulomoides dermestoides fat improves diabetes: effect on liver and pancreatic architecture and on PPARγ expression

    Directory of Open Access Journals (Sweden)

    E.I. Jasso-Villagomez

    2018-04-01

    Full Text Available Ulomoides dermestoides is a beetle traditionally consumed to treat diabetes. In this study, we performed a composition analysis of U. dermestoides to obtain the principal fractions, which were used to assess the effect on glycemia, liver and pancreatic architecture, and PPARγ and GLUT4 expression. Normal mice and alloxan-induced diabetic mice were administered fractions of chitin, protein or fat, and the acute hypoglycemic effect was evaluated. A subacute study involving daily administration of these fractions to diabetic mice was also performed over 30 days, after which the liver and pancreas were processed by conventional histological techniques and stained with hematoxylin and eosin to evaluate morphological changes. The most active fraction, the fat fraction, was analyzed by gas chromatography-mass spectrometry (GC-MS, and PPARγ and GLUT4 mRNA expressions were determined in 3T3-L1 adipocytes. The protein and fat fractions exhibited hypoglycemic effects in the acute as well as in the 30-day study. Only the fat fraction led to elevated insulin levels and reduced glycemia, as well as lower intake of water and food. In the liver, we observed recovery of close hepatic cords in the central lobule vein following treatment with the fat fraction, while in the pancreas there was an increased density and percentage of islets and number of cells per islet, suggesting cellular regeneration. The GC-MS analysis of fat revealed three fatty acids as the major components. Finally, increased expression of PPARγ and GLUT4 was observed in 3T3-L1 adipocytes, indicating an antidiabetic effect.

  3. Expression of glucocorticoid receptor and glucose transporter-1 during placental development in the diabetic rat

    Directory of Open Access Journals (Sweden)

    Ramazan Demir

    2011-07-01

    Full Text Available In various tissues, glucocorticoids (GCs are known to downregulate glucose transport systems; however, their effects on glucose transporters (GLUTs in the placenta of a diabetic rat are unknown. Glucocorticoid hormone action within the cell is regulated by the glucocorticoid receptor (GR. Thus, this study was designed to investigate the relationship between GR and glucose transporter expression in the placenta of the diabetic rat. Our immunohistochemical results indicated that GR and glucose transporter protein 1 (GLUT 1 are expressed ubiquitously in the trophoblast and endothelial cells of the labyrinthine zone, where maternal fetal transport takes place in the rat placenta. Expression of GR in the junctional zone of the rat placenta was detected in giant cells, and in some spongiotrophoblast cells, but not in the glycogen cells. GLUT 1 was present, especially in glycogen cells during early pregnancy, and in the spongiotrophoblast cells of the junctional zone during late pregnancy. Amounts of GR and GLUT 1 protein were increased towards the end of gestation both in the control and the diabetic placenta. However, at days 17 and 19 of gestation, only the placental GR protein was significantly increased in the streptozotocin-induced diabetic rats compared to control rats. Diabetes led to a significant decrease in placental weight at gestation day 15. In contrast, at gestational days 17 and 21, the weights of the diabetic placenta were significantly increased as compared with the controls. Moreover, diabetes induced fetus intrauterine growth retardation at gestational days 13, 17 and 21. In conclusion, the localization pattern of GR and GLUT 1 proteins in the same cell types led us to believe that there might be a relationship between GR and GLUT 1 expressions at the cellular level. GLUT 1 does not play a pivotal role in diabetic pregnancies. However, placental growth abnormalities during diabetic pregnancy may be related to the amount of GR

  4. Selective insulin resistance in hepatocyte senescence

    International Nuclear Information System (INIS)

    Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

    2015-01-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance

  5. Selective insulin resistance in hepatocyte senescence

    Energy Technology Data Exchange (ETDEWEB)

    Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  6. Gene expression and 18FDG uptake in atherosclerotic carotid plaques

    DEFF Research Database (Denmark)

    Pedersen, Sune Folke; Graebe, Martin; Fisker Hag, Anne Mette

    2010-01-01

    ) and an additional ipsilateral internal carotid artery stenosis of greater than 60% were recruited. FDG uptake in the carotids was determined by PET/computed tomography and expressed as mean and maximal standardized uptake values (SUVmean and SUVmax). The atherosclerotic plaques were subsequently recovered...... by carotid endarterectomy. The gene expression of markers of vulnerability - CD68, IL-18, matrix metalloproteinase 9, cathepsin K, GLUT-1, and hexokinase type II (HK2) - were measured in plaques by quantitative PCR. RESULTS: In a multivariate linear regression model, GLUT-1, CD68, cathepsin K, and HK2 gene...... expression remained in the final model as predictive variables of FDG accumulation calculated as SUVmean (R=0.26, PK, and HK2 gene expression as independent predictive variables of FDG accumulation calculated...

  7. Gene expression of tumour necrosis factor and insulin signalling-related factors in subcutaneous adipose tissue during the dry period and in early lactation in dairy cows.

    Science.gov (United States)

    Sadri, H; Bruckmaier, R M; Rahmani, H R; Ghorbani, G R; Morel, I; van Dorland, H A

    2010-10-01

    Gene expression of adipose factors, which may be part of the mechanisms that underlie insulin sensitivity, were studied in dairy cows around parturition. Subcutaneous fat biopsies and blood samples were taken from 27 dairy cows in week 8 antepartum (a.p.), on day 1 postpartum (p.p.) and in week 5 p.p. In the adipose tissue samples, mRNA was quantified by real-time reverse transcription polymerase chain reaction for tumour necrosis factor alpha (TNFα), insulin-independent glucose transporter (GLUT1), insulin-responsive glucose transporter (GLUT4), insulin receptor, insulin receptor substrate 1 (IRS1), insulin receptor substrate 2 (IRS2), regulatory subunit of phosphatidylinositol-3 kinase (p85) and catalytic subunit of phosphatidylinositol-3 kinase. Blood plasma was assayed for concentrations of glucose, β-hydroxybutyric acid, non-esterified fatty acids (NEFA) and insulin. Plasma parameters followed a pattern typically observed in dairy cows. Gene expression changes were observed, but there were no changes in TNFα concentrations, which may indicate its local involvement in catabolic adaptation of adipose tissue. Changes in GLUT4 and GLUT1 mRNA abundance may reflect their involvement in reduced insulin sensitivity and in sparing glucose for milk synthesis in early lactation. Unchanged gene expression of IRS1, IRS2 and p85 over time may imply a lack of their involvement in terms of insulin sensitivity dynamics. Alternatively, it may indicate that post-transcriptional modifications of these factors came into play and may have concealed an involvement. © 2010 Blackwell Verlag GmbH.

  8. Pioglitazone reverses down-regulation of cardiac PPARγ expression in Zucker diabetic fatty rats

    International Nuclear Information System (INIS)

    Pelzer, Theo; Jazbutyte, Virginija; Arias-Loza, Paula Anahi; Segerer, Stephan; Lichtenwald, Margit; Law, Marilyn P.; Schaefers, Michael; Ertl, Georg; Neyses, Ludwig

    2005-01-01

    Peroxisome proliferator-activated receptor-γ (PPARγ) plays a critical role in peripheral glucose homeostasis and energy metabolism, and inhibits cardiac hypertrophy in non-diabetic animal models. The functional role of PPARγ in the diabetic heart, however, is not fully understood. Therefore, we analyzed cardiac gene expression, metabolic control, and cardiac glucose uptake in male Zucker diabetic fatty rats (ZDF fa/fa) and lean ZDF rats (+/+) treated with the high affinity PPARγ agonist pioglitazone or placebo from 12 to 24 weeks of age. Hyperglycemia, hyperinsulinemia, and hypertriglyceridemia as well as lower cardiac PPARγ, glucose transporter-4 and α-myosin heavy chain expression levels were detected in diabetic ZDF rats compared to lean animals. Pioglitazone increased body weight and improved metabolic control, cardiac PPARγ, glut-4, and α-MHC expression levels in diabetic ZDF rats. Cardiac [ 18 F]fluorodeoxyglucose uptake was not detectable by micro-PET studies in untreated and pioglitazone treated ZDF fa/fa rats but was observed after administration of insulin to pioglitazone treated ZDF fa/fa rats. PPARγ agonists favorably affect cardiac gene expression in type-2 diabetic rats via activation and up-regulation of cardiac PPARγ expression whereas improvement of impaired cardiac glucose uptake in advanced type-2 diabetes requires co-administration of insulin

  9. All-trans retinoic acid increases the expression of oxidative myosin heavy chain through the PPARδ pathway in bovine muscle cells derived from satellite cells.

    Science.gov (United States)

    Kim, Jongkyoo; Wellmann, Kimberly B; Smith, Zachary K; Johnson, Bradley J

    2018-04-24

    All-trans retinoic acid (ATRA) has been associated with various physiological phenomenon in mammalian adipose tissue and skeletal muscle. We hypothesized that ATRA may affect skeletal muscle fiber type in bovine satellite cell culture through various transcriptional processes. Bovine primary satellite cell (BSC) culture experiments were conducted to determine dose effects of ATRA on expression of genes and protein levels related to skeletal muscle fiber type and metabolism. The semimembranosus from crossbred steers (n = 2 steers), aged approximately 24 months, were used to isolate BSC for 3 separate assays. Myogenic differentiation was induced using 3% horse serum upon cultured BSC with increasing doses (0, 1, 10, 100, 1000 nM) of ATRA. After 96 h of incubation, cells were harvested and used to measure the gene expression of protein kinase B (Akt), AMP-activated protein kinase alpha (AMPK), glucose transporter 4 (GLUT4), myogenin, lipoprotein lipase (LPL), myosin heavy chain (MHC) I, MHC IIA,MHC IIX, insulin like growth factor -1 (IGF-1), Peroxisome proliferator activated receptor gamma (PPARγ), PPARδ, and Smad transcription factor 3 (SMAD3) mRNA relative to ribosomal protein subunit 9 (RPS9). The mRNA expression of LPL was increased (P < 0.05) with 100 and 1000nM of ATRA. Expression of GLUT4 was altered (P < 0.05) by ATRA. The treatment of ATRA (1000nM) also increased (P < 0.05) mRNA gene expression of SMAD3. The gene expression of both PPARδ and PPARγ were increased (P < 0.05) with 1000nM of ATRA. Protein level of PPARδ was also affected (P < 0.05) by 1000nM of ATRA and resulted in a greater (P < 0.05) protein level of PPARδ compared to CON. All-trans retinoic acid (10nM) increased gene expression of MHC I (P < 0.05) compared to CON. Expression of MHC IIA was also influenced (P < 0.05) by ATRA. The mRNA expression of MHC IIX was decreased (P < 0.05) with 100 and 1000nM of ATRA.In muscle cells, ATRA may cause muscle fibers to transition towards the MHC

  10. Complex analysis of urate transporters SLC2A9, SLC22A12 and functional characterization of non-synonymous allelic variants of GLUT9 in the Czech population: no evidence of effect on hyperuricemia and gout.

    Directory of Open Access Journals (Sweden)

    Olha Hurba

    Full Text Available OBJECTIVE: Using European descent Czech populations, we performed a study of SLC2A9 and SLC22A12 genes previously identified as being associated with serum uric acid concentrations and gout. This is the first study of the impact of non-synonymous allelic variants on the function of GLUT9 except for patients suffering from renal hypouricemia type 2. METHODS: The cohort consisted of 250 individuals (150 controls, 54 nonspecific hyperuricemics and 46 primary gout and/or hyperuricemia subjects. We analyzed 13 exons of SLC2A9 (GLUT9 variant 1 and GLUT9 variant 2 and 10 exons of SLC22A12 by PCR amplification and sequenced directly. Allelic variants were prepared and their urate uptake and subcellular localization were studied by Xenopus oocytes expression system. The functional studies were analyzed using the non-parametric Wilcoxon and Kruskall-Wallis tests; the association study used the Fisher exact test and linear regression approach. RESULTS: We identified a total of 52 sequence variants (12 unpublished. Eight non-synonymous allelic variants were found only in SLC2A9: rs6820230, rs2276961, rs144196049, rs112404957, rs73225891, rs16890979, rs3733591 and rs2280205. None of these variants showed any significant difference in the expression of GLUT9 and in urate transport. In the association study, eight variants showed a possible association with hyperuricemia. However, seven of these were in introns and the one exon located variant, rs7932775, did not show a statistically significant association with serum uric acid concentration. CONCLUSION: Our results did not confirm any effect of SLC22A12 and SLC2A9 variants on serum uric acid concentration. Our complex approach using association analysis together with functional and immunohistochemical characterization of non-synonymous allelic variants did not show any influence on expression, subcellular localization and urate uptake of GLUT9.

  11. Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis

    International Nuclear Information System (INIS)

    Martins, Sandra Fernandes; Amorim, Ricardo; Viana-Pereira, Marta; Pinheiro, Céline; Costa, Ricardo Filipe Alves; Silva, Patrícia; Couto, Carla; Alves, Sara; Fernandes, Sara; Vilaça, Sónia; Falcão, Joaquim; Marques, Herlander; Pardal, Fernando; Rodrigues, Mesquita; Preto, Ana; Reis, Rui Manuel; Longatto-Filho, Adhemar; Baltazar, Fátima

    2016-01-01

    Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis. Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry. All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting. These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC

  12. Microsatellite alterations in head and neck squamous cell carcinoma and relation to expression of pimonidazole, CA IX and GLUT-1

    International Nuclear Information System (INIS)

    Schutter, Harlinde de; Barbe, Barbara; Spaepen, Marijke

    2006-01-01

    Background and Purpose: Because the locoregional control for HNSCC is still disappointing, research efforts focus on the exploration of new molecular markers located in both tumour and microenvironment, which could help stratify patients. The aim of the present work was therefore first to assess microsatellite alterations and hypoxia in HNSCC as possible molecular markers. Second, a relation between both was investigated, as hypoxia is known to select for genetic alterations. Material and methods: Forty-eight patients with advanced HNSCC treated by surgery ± radiotherapy were included. MSI and LOH were investigated with microsatellite markers using automatic fragment analysis. The presence of hypoxia was assessed by immunohistochemistry for pimonidazole, CA IX and GLUT-1. The mutual relationship between MSI/LOH and hypoxia was evaluated. Results: No MSI was detected in this patient group. LOH occurred mostly on chromosomal arms 3p, 5q, 9p, 17p and 17q. Patients with LOH at D17S799, located in the near environment of p53, showed a higher CA IX expression (p = 0.01). Conclusions: LOH is a possible molecular marker in HNSCC. The positive correlation between LOH at D17S799 and CA IX is in full concordance with previous publications linking hypoxia to selective pressure on the p53 gene

  13. The Monocarboxylate Transporter Inhibitor α-Cyano-4-Hydroxycinnamic Acid Disrupts Rat Lung Branching

    Directory of Open Access Journals (Sweden)

    Sara Granja

    2013-12-01

    Full Text Available Background/Aims: The human embryo develops in a hypoxic environment. In this way, cells have to rely on the glycolytic pathway for energy supply, leading to an intracellular accumulation of monocarboxylates such as lactate and pyruvate. These acids have an important role in cell metabolism and their rapid transport across the plasma membrane is crucial for the maintenance of intracellular pH homeostasis. This transport is mediated by a family of transporters, designated by monocarboxylate transporters (MCTs, namely isoforms 1 and 4. MCT1/4 expression is regulated by the ancillary protein CD147.The general aim of this study was to characterize the expression pattern of MCT1/4, CD147 and the glucose transporter GLUT1 during human fetal lung development and elucidate the role of MCTs in lung development. Methods: The expression pattern of MCT1/4 and GLUT1 was characterized by immunohistochemistry and fetal lung viability and branching were evaluated by exposing rat fetal lung explants to CHC, an inhibitor of MCT activity. Results: Our findings show that all the biomarkers are differently expressed during fetal lung development and that CHC appears to have an inhibitory effect on lung branching and viability, in a dose dependent way. Conclusion: We provide evidence for the role of MCTs in embryo lung development, however to prove the dependence of MCT activity further studies are waranted.

  14. Dendrobium nobile Lindl. alkaloids regulate metabolism gene expression in livers of mice.

    Science.gov (United States)

    Xu, Yun-Yan; Xu, Ya-Sha; Wang, Yuan; Wu, Qin; Lu, Yuan-Fu; Liu, Jie; Shi, Jing-Shan

    2017-10-01

    In our previous studies, Dendrobium nobile Lindl. alkaloids (DNLA) has been shown to have glucose-lowering and antihyperlipidaemia effects in diabetic rats, in rats fed with high-fat diets, and in mice challenged with adrenaline. This study aimed to examine the effects of DNLA on the expression of glucose and lipid metabolism genes in livers of mice. Mice were given DNLA at doses of 10-80 mg/kg, po for 8 days, and livers were removed for total RNA and protein isolation to perform real-time RT-PCR and Western blot analysis. Dendrobium nobile Lindl. alkaloids increased PGC1α at mRNA and protein levels and increased glucose metabolism gene Glut2 and FoxO1 expression. DNLA also increased the expression of fatty acid β-oxidation genes Acox1 and Cpt1a. The lipid synthesis regulator Srebp1 (sterol regulatory element-binding protein-1) was decreased, while the lipolysis gene ATGL was increased. Interestingly, DNLA increased the expression of antioxidant gene metallothionein-1 and NADPH quinone oxidoreductase-1 (Nqo1) in livers of mice. Western blot on selected proteins confirmed these changes including the increased expression of GLUT4 and PPARα. DNLA has beneficial effects on liver glucose and lipid metabolism gene expressions, and enhances the Nrf2-antioxidant pathway gene expressions, which could play integrated roles in regulating metabolic disorders. © 2017 Royal Pharmaceutical Society.

  15. Ketone Bodies as a Possible Adjuvant to Ketogenic Diet in PDHc Deficiency but Not in GLUT1 Deficiency.

    Science.gov (United States)

    Habarou, F; Bahi-Buisson, N; Lebigot, E; Pontoizeau, C; Abi-Warde, M T; Brassier, A; Le Quan Sang, K H; Broissand, C; Vuillaumier-Barrot, S; Roubertie, A; Boutron, A; Ottolenghi, C; de Lonlay, P

    2018-01-01

    Ketogenic diet is the first line therapy for neurological symptoms associated with pyruvate dehydrogenase deficiency (PDHD) and intractable seizures in a number of disorders, including GLUT1 deficiency syndrome (GLUT1-DS). Because high-fat diet raises serious compliance issues, we investigated if oral L,D-3-hydroxybutyrate administration could be as effective as ketogenic diet in PDHD and GLUT1-DS. We designed a partial or total progressive substitution of KD with L,D-3-hydroxybutyrate in three GLUT1-DS and two PDHD patients. In GLUT1-DS patients, we observed clinical deterioration including increased frequency of seizures and myoclonus. In parallel, ketone bodies in CSF decreased after introducing 3-hydroxybutyrate. By contrast, two patients with PDHD showed clinical improvement as dystonic crises and fatigability decreased under basal metabolic conditions. In one of the two PDHD children, 3-hydroxybutyrate has largely replaced the ketogenic diet, with the latter that is mostly resumed only during febrile illness. Positive direct effects on energy metabolism in PDHD patients were suggested by negative correlation between ketonemia and lactatemia (r 2  = 0.59). Moreover, in cultured PDHc-deficient fibroblasts, the increase of CO 2 production after 14 C-labeled 3-hydroxybutyrate supplementation was consistent with improved Krebs cycle activity. However, except in one patient, ketonemia tended to be lower with 3-hydroxybutyrate administration compared to ketogenic diet. 3-hydroxybutyrate may be an adjuvant treatment to ketogenic diet in PDHD but not in GLUT1-DS under basal metabolic conditions. Nevertheless, ketogenic diet is still necessary in PDHD patients during febrile illness.

  16. Cortisol increases CXCR4 expression but does not affect CD62L and CCR7 levels on specific T cell subsets in humans.

    Science.gov (United States)

    Besedovsky, Luciana; Linz, Barbara; Dimitrov, Stoyan; Groch, Sabine; Born, Jan; Lange, Tanja

    2014-06-01

    Glucocorticoids are well known to affect T cell migration, leading to a redistribution of the cells from blood to the bone marrow, accompanied by a concurrent suppression of lymph node homing. Despite numerous studies in this context, with most of them employing synthetic glucocorticoids in nonphysiological doses, the mechanisms of this redistribution are not well understood. Here, we investigated in healthy men the impact of cortisol at physiological concentrations on the expression of different migration molecules on eight T cell subpopulations in vivo and in vitro. Hydrocortisone (cortisol, 22 mg) infused during nocturnal rest when endogenous cortisol levels are low, compared with placebo, differentially reduced numbers of T cell subsets, with naive CD4(+) and CD8(+) subsets exhibiting the strongest reduction. Hydrocortisone in vivo and in vitro increased CXCR4 expression, which presumably mediates the recruitment of T cells to the bone marrow. Expression of the lymph node homing receptor CD62L on total CD3(+) and CD8(+) T cells appeared reduced following hydrocortisone infusion. However, this was due to a selective extravasation of CD62L(+) T cell subsets, as hydrocortisone affected neither CD62L expression on a subpopulation level nor CD62L expression in vitro. Corresponding results in the opposite direction were observed after blocking of endogenous cortisol synthesis by metyrapone. CCR7, another lymph node homing receptor, was also unaffected by hydrocortisone in vitro. Thus, cortisol seems to redirect T cells to the bone marrow by upregulating their CXCR4 expression, whereas its inhibiting effect on T cell homing to lymph nodes is apparently regulated independently of the expression of classical homing receptors. Copyright © 2014 the American Physiological Society.

  17. Functional expression of sodium-glucose transporters in cancer

    Science.gov (United States)

    Scafoglio, Claudio; Hirayama, Bruce A.; Kepe, Vladimir; Liu, Jie; Ghezzi, Chiara; Satyamurthy, Nagichettiar; Moatamed, Neda A.; Huang, Jiaoti; Koepsell, Hermann; Barrio, Jorge R.; Wright, Ernest M.

    2015-01-01

    Glucose is a major metabolic substrate required for cancer cell survival and growth. It is mainly imported into cells by facilitated glucose transporters (GLUTs). Here we demonstrate the importance of another glucose import system, the sodium-dependent glucose transporters (SGLTs), in pancreatic and prostate adenocarcinomas, and investigate their role in cancer cell survival. Three experimental approaches were used: (i) immunohistochemical mapping of SGLT1 and SGLT2 distribution in tumors; (ii) measurement of glucose uptake in fresh isolated tumors using an SGLT-specific radioactive glucose analog, α-methyl-4-deoxy-4-[18F]fluoro-d-glucopyranoside (Me4FDG), which is not transported by GLUTs; and (iii) measurement of in vivo SGLT activity in mouse models of pancreatic and prostate cancer using Me4FDG-PET imaging. We found that SGLT2 is functionally expressed in pancreatic and prostate adenocarcinomas, and provide evidence that SGLT2 inhibitors block glucose uptake and reduce tumor growth and survival in a xenograft model of pancreatic cancer. We suggest that Me4FDG-PET imaging may be used to diagnose and stage pancreatic and prostate cancers, and that SGLT2 inhibitors, currently in use for treating diabetes, may be useful for cancer therapy. PMID:26170283

  18. Effects of ketamine on glucose uptake by glucose transporter type 3 expressed in Xenopus oocytes: The role of protein kinase C

    Energy Technology Data Exchange (ETDEWEB)

    Tomioka, Shigemasa, E-mail: tomioka@dent.tokushima-u.ac.jp [Department of Dental Anesthesiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho 18-15, Tokushima City, Tokushima 770-8504 (Japan); Kaneko, Miyuki [Department of Dental Anesthesiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho 18-15, Tokushima City, Tokushima 770-8504 (Japan); Satomura, Kazuhito [First Department of Oral and Maxillofacial Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho 18-15, Tokushima City, Tokushima 770-8504 (Japan); Mikyu, Tomiko; Nakajo, Nobuyoshi [Department of Dental Anesthesiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho 18-15, Tokushima City, Tokushima 770-8504 (Japan)

    2009-10-09

    We investigated the effects of ketamine on the type 3 facilitative glucose transporter (GLUT3), which plays a major role in glucose transport across the plasma membrane of neurons. Human-cloned GLUT3 was expressed in Xenopus oocytes by injection of GLUT3 mRNA. GLUT3-mediated glucose uptake was examined by measuring oocyte radioactivity following incubation with 2-deoxy-D-[1,2-{sup 3}H]glucose. While ketamine and S(+)-ketamine significantly increased GLUT3-mediated glucose uptake, this effect was biphasic such that higher concentrations of ketamine inhibited glucose uptake. Ketamine (10 {mu}M) significantly increased V{sub max} but not K{sub m} of GLUT3 for 2-deoxy-D-glucose. Although staurosporine (a protein kinase C inhibitor) increased glucose uptake, no additive or synergistic interactions were observed between staurosporine and racemic ketamine or S(+)-ketamine. Treatment with ketamine or S(+)-ketamine partially prevented GLUT3 inhibition by the protein kinase C activator phorbol-12-myrisate-13-acetate. Our results indicate that ketamine increases GLUT3 activity at clinically relevant doses through a mechanism involving PKC inhibition.

  19. Effects of ketamine on glucose uptake by glucose transporter type 3 expressed in Xenopus oocytes: The role of protein kinase C

    International Nuclear Information System (INIS)

    Tomioka, Shigemasa; Kaneko, Miyuki; Satomura, Kazuhito; Mikyu, Tomiko; Nakajo, Nobuyoshi

    2009-01-01

    We investigated the effects of ketamine on the type 3 facilitative glucose transporter (GLUT3), which plays a major role in glucose transport across the plasma membrane of neurons. Human-cloned GLUT3 was expressed in Xenopus oocytes by injection of GLUT3 mRNA. GLUT3-mediated glucose uptake was examined by measuring oocyte radioactivity following incubation with 2-deoxy-D-[1,2- 3 H]glucose. While ketamine and S(+)-ketamine significantly increased GLUT3-mediated glucose uptake, this effect was biphasic such that higher concentrations of ketamine inhibited glucose uptake. Ketamine (10 μM) significantly increased V max but not K m of GLUT3 for 2-deoxy-D-glucose. Although staurosporine (a protein kinase C inhibitor) increased glucose uptake, no additive or synergistic interactions were observed between staurosporine and racemic ketamine or S(+)-ketamine. Treatment with ketamine or S(+)-ketamine partially prevented GLUT3 inhibition by the protein kinase C activator phorbol-12-myrisate-13-acetate. Our results indicate that ketamine increases GLUT3 activity at clinically relevant doses through a mechanism involving PKC inhibition.

  20. Exposure of Pregnant Mice to Triclosan Causes Insulin Resistance via Thyroxine Reduction.

    Science.gov (United States)

    Hua, Xu; Cao, Xin-Yuan; Wang, Xiao-Li; Sun, Peng; Chen, Ling

    2017-11-01

    Exposure to triclosan (TCS), an antibacterial agent, during pregnancy is associated with hypothyroxinemia and decreases in placental glucose transporter expression and activity. The objective of this study was to investigate the influence of TCS on glucose homeostasis and insulin sensitivity in gestational mice (G-mice) and nongestational female mice (Ng-mice) as a control. Herein, we show that the exposure of G-mice to TCS (8 mg/kg) from gestational day (GD) 5 to GD17 significantly increased their levels of fasting plasma glucose and serum insulin, and insulin content in pancreatic β-cells with reduced homeostasis model assessment (HOMA)-β index and increased HOMA-IR index. Area under curve (AUC) of glucose and insulin tolerance tests in TCS (8 mg/kg)-treated G-mice were markedly larger than controls. When compared with controls, TCS (8 mg/kg)-treated G-mice showed a significant decrease in the levels of thyroxine and triiodothyroninelevels, PPARγ and glucose transporter 4 (GLUT4) expression, and Akt phosphorylation in adipose tissue and muscle. Replacement of L-thyroxine in TCS (8 mg/kg)-treated G-mice corrected their insulin resistance and recovered the levels of insulin, PPARγ and GLUT4 expression, and Akt phosphorylation. Activation of PPARγ by administration of rosiglitazone recovered the decrease in Akt phosphorylation, but not GLUT4 expression. Although exposure to TCS (8 mg/kg) in Ng-mice reduced thyroid hormones levels, it did not cause the insulin resistance or affect PPARγ and GLUT4 expression, and Akt phosphorylation. The findings indicate that the exposure of gestational mice to TCS (≥8 mg/kg) results in insulin resistance via thyroid hormones reduction. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Expression Patterns and Correlations with Metabolic Markers of Zinc Transporters ZIP14 and ZNT1 in Obesity and Polycystic Ovary Syndrome

    Science.gov (United States)

    Maxel, Trine; Svendsen, Pernille Fog; Smidt, Kamille; Lauridsen, Jesper Krogh; Brock, Birgitte; Pedersen, Steen Bønlykke; Rungby, Jørgen; Larsen, Agnete

    2017-01-01

    Polycystic ovary syndrome (PCOS) is associated with infertility, increased androgen levels, and insulin resistance. In adipose tissue, zinc facilitates insulin signaling. Circulating zinc levels are altered in obesity, diabetes, and PCOS; and zinc supplementation can ameliorate metabolic disturbances in PCOS. In adipose tissue, expression of zinc influx transporter ZIP14 varies with body mass index (BMI), clinical markers of metabolic syndrome, and peroxisome proliferator-activated receptor gamma (PPARG). In this study, we investigated expression levels of ZIP14 and PPARG in subcutaneous adipose tissue of 36 PCOS women (17 lean and 19 obese women) compared with 23 healthy controls (7 lean and 16 obese women). Further, expression levels of zinc transporter ZIP9, a recently identified androgen receptor, and zinc efflux transporter ZNT1 were investigated, alongside lipid profile and markers of glucose metabolism [insulin degrading enzyme, retinol-binding protein 4 (RBP4), and glucose transporter 4 (GLUT4)]. We find that ZIP14 expression is reduced in obesity and positively correlates with PPARG expression, which is downregulated with increasing BMI. ZNT1 is upregulated in obesity, and both ZIP14 and ZNT1 expression significantly correlates with clinical markers of altered glucose metabolism. In addition, RBP4 and GLUT4 associate with obesity, but an association with PCOS as such was present only for PPARG and RBP4. ZIP14 and ZNT1 does not relate to clinical androgen status and ZIP9 is unaffected by all parameters investigated. In conclusion, our findings support the existence of a zinc dyshomeostasis in adipose tissue in metabolic disturbances including PCOS-related obesity. PMID:28303117

  2. Prenatal physical activity and diet composition affect the expression of nutrient transporters and mTOR signaling molecules in the human placenta.

    Science.gov (United States)

    Brett, K E; Ferraro, Z M; Holcik, M; Adamo, K B

    2015-02-01

    Adequate nutrient delivery to the fetus is essential for optimal growth. Differences in prenatal physical activity level and diet quality influence maternal energy balance and these factors may alter placental nutrient transport. We investigated the associations between meeting physical activity guidelines and the quality of maternal diet on the expression of genes involved in fatty acid, amino acid and glucose transport, and mammalian target of rapamycin (mTOR) and insulin signaling in the placenta from 16 term pregnancies. Physical activity was directly measured with accelerometry, diet composition was assessed with 24 h dietary recalls, and gene expression was measured with custom polymerase chain reaction (PCR) arrays. Women who met physical activity guidelines had lower gene expression of fatty acid transport protein 4 (FATP4), insulin-like growth factor 1 (IGF1), and the beta non-catalytic subunit of AMP-activated protein kinase (AMPK), and a higher expression of SNAT2. There was a strong positive correlation observed between total sugar intake and glucose transporter 1 (GLUT1) (r = 0.897, p = 0.000, n = 12), and inverse correlations between total sugar and mTOR and IGF1 expression. Percentage of total calories from protein was inversely related to insulin-like growth factor 1 receptor (IGF1R) (r = -0.605, p = 0.028, n = 13). Variations in maternal physical activity and diet composition altered the expression of genes involved in fatty acid, amino acid and glucose transport and mTOR signaling. Future research on placental nutrient transport should include direct measures of maternal PA and dietary habits to help eliminate confounding factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Assessment of metabolic and mitochondrial dynamics in CD4+ and CD8+ T cells in virologically suppressed HIV-positive individuals on combination antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Jesse J R Masson

    Full Text Available Metabolism plays a fundamental role in supporting the growth, proliferation and effector functions of T cells. We investigated the impact of HIV infection on key processes that regulate glucose uptake and mitochondrial biogenesis in subpopulations of CD4+ and CD8+ T cells from 18 virologically-suppressed HIV-positive individuals on combination antiretroviral therapy (cART; median CD4+ cell count: 728 cells/μl and 13 HIV seronegative controls. Mitochondrial membrane potential (MMP and reactive oxygen species (ROS production were also analysed in total CD4+ and CD8+ T cells. Among HIV+/cART individuals, expression of glucose transporter (Glut1 and mitochondrial density were highest within central memory and naïve CD4+ T cells, and lowest among effector memory and transitional memory T cells, with similar trends in HIV-negative controls. Compared to HIV-negative controls, there was a trend towards higher percentage of circulating CD4+Glut1+ T cells in HIV+/cART participants. There were no significant differences in mitochondrial dynamics between subject groups. Glut1 expression was positively correlated with mitochondrial density and MMP in total CD4+ T cells, while MMP was also positively correlated with ROS production in both CD4+ and CD8+ T cells. Our study characterizes specific metabolic features of CD4+ and CD8+ T cells in HIV-negative and HIV+/cART individuals and will invite future studies to explore the immunometabolic consequences of HIV infection.

  4. Genetic variation of the GLUT10 glucose transporter (SLC2A10) and relationships to type 2 diabetes and intermediary traits

    DEFF Research Database (Denmark)

    Andersen, Gitte; Rose, Christian Schack; Hamid, Yasmin Hassan

    2003-01-01

    The SLC2A10 gene encodes the GLUT10 facilitative glucose transporter, which is expressed in high amounts in liver and pancreas. The gene is mapped to chromosome 20q12-q13.1, a region that has been shown to be linked to type 2 diabetes. The gene was examined in 61 Danish type 2 diabetic patients......, and a total of six variants (-27C-->T, Ala206Thr, Ala272Ala, IVS2 + 10G-->A, IVS4 + 18T-->G, and IVS4 + 26G-->A) were identified and investigated in an association study, which included 503 type 2 diabetic patients and 510 glucose-tolerant control subjects. None of the variants were associated with type 2...... substantially to the pathogenesis of type 2 diabetes in the examined study population. However, the codon 206 polymorphism may be related to the interindividual variation in fasting and oral glucose-induced serum insulin levels....

  5. Glucose Metabolism Gene Expression Patterns and Tumor Uptake of 18F-Fluorodeoxyglucose After Radiation Treatment

    International Nuclear Information System (INIS)

    Wilson, George D.; Thibodeau, Bryan J.; Fortier, Laura E.; Pruetz, Barbara L.; Galoforo, Sandra; Baschnagel, Andrew M.; Chunta, John; Oliver Wong, Ching Yee; Yan, Di; Marples, Brian; Huang, Jiayi

    2014-01-01

    Purpose: To investigate whether radiation treatment influences the expression of glucose metabolism genes and compromises the potential use of 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) as a tool to monitor the early response of head and neck cancer xenografts to radiation therapy (RT). Methods and Materials: Low passage head and neck squamous cancer cells (UT14) were injected to the flanks of female nu/nu mice to generate xenografts. After tumors reached a size of 500 mm 3 they were treated with either sham RT or 15 Gy in 1 fraction. At different time points, days 3, 9, and 16 for controls and days 4, 7, 12, 21, 30, and 40 after irradiation, 2 to 3 mice were assessed with dynamic FDG-PET acquisition over 2 hours. Immediately after the FDG-PET the tumors were harvested for global gene expression analysis and immunohistochemical evaluation of GLUT1 and HK2. Different analytic parameters were used to process the dynamic PET data. Results: Radiation had no effect on key genes involved in FDG uptake and metabolism but did alter other genes in the HIF1α and glucose transport–related pathways. In contrast to the lack of effect on gene expression, changes in the protein expression patterns of the key genes GLUT1/SLC2A1 and HK2 were observed after radiation treatment. The changes in GLUT1 protein expression showed some correlation with dynamic FDG-PET parameters, such as the kinetic index. Conclusion: 18 F-fluorodeoxyglucose positron emission tomography changes after RT would seem to represent an altered metabolic state and not a direct effect on the key genes regulating FDG uptake and metabolism

  6. Association of single nucleotide polymorphisms in the gene encoding GLUT1 and diabetic nephropathy in Brazilian patients with type 1 diabetes mellitus.

    Science.gov (United States)

    Marques, T; Patente, T A; Monteiro, M B; Cavaleiro, A M; Queiroz, M S; Nery, M; de Azevedo, M J; Canani, L H; Parisi, M C; Moura-Neto, A; Passarelli, M; Giannella-Neto, D; Machado, U F; Corrêa-Giannella, M L

    2015-04-15

    Mesangial cells subject to high extracellular glucose concentrations, as occur in hyperglycaemic states, are unable to down regulate glucose influx, resulting in intracellular activation of deleterious biochemical pathways. A high expression of GLUT1 participates in the development of diabetic glomerulopathy. Variants in the gene encoding GLUT1 (SLC2A1) have been associated to this diabetic complication. The aim of this study was to test whether polymorphisms in SLC2A1 confer susceptibility to diabetic nephropathy (DN) in Brazilian type 1 diabetes patients. Four polymorphisms (rs3820589, rs1385129, rs841847 and rs841848) were genotyped in a Brazilian cohort comprised of 452 patients. A prospective analysis was performed in 155 patients. Mean duration of follow-up was 5.6 ± 2.4 years and the incidence of renal events was 18.0%. The rs3820589 presented an inverse association with the prevalence of incipient DN (OR: 0.36, 95% CI: 0.16 - 0.80, p=0.01) and with progression to renal events (HR: 0.20; 95% CI: 0.03 - 0.70; p=0.009). AGGT and AGAC haplotypes were associated with the prevalence of incipient DN and the AGAC haplotype was also associated with the prevalence of established/advanced DN. In conclusion, rs3820589 in the SLC2A1 gene modulates the risk to DN in Brazilian patients with inadequate type 1 diabetes control. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. The small intestinal epithelia of beef steers differentially express sugar transporter messenger ribonucleic acid in response to abomasal versus ruminal infusion of starch hydrolysate.

    Science.gov (United States)

    Liao, S F; Harmon, D L; Vanzant, E S; McLeod, K R; Boling, J A; Matthews, J C

    2010-01-01

    In mammals, the absorption of monosaccharides from small intestinal lumen involves at least 3 sugar transporters (SugT): sodium-dependent glucose transporter 1 (SGLT1; gene SLC5A1) transports glucose and galactose, whereas glucose transporter (GLUT) 5 (GLUT5; gene SLC2A5) transports fructose, across the apical membrane of enterocytes. In contrast, GLUT2 (gene SLC2A2) transports all of these sugars across basolateral and apical membranes. To compare the distribution patterns and sensitivity with nutritional regulation of these 3 SugT mRNA in beef cattle small intestinal tissue, 18 ruminally and abomasally catheterized Angus steers (BW approximately 260 kg) were assigned to water (control), ruminal cornstarch (partially hydrolyzed by alpha-amylase; SH), or abomasal SH infusion treatments (n = 6) and fed an alfalfa-cube-based diet at 1.3 x NE(m) requirement. The SH infusions amounted to 20% of ME intake. After 14- or 16-d of infusion, steers were killed; duodenal, jejunal, and ileal epithelia harvested; and total RNA extracted. The relative amount of SugT mRNA in epithelia was determined using real-time reverse transcription-PCR quantification methods. Basal expression of GLUT2 and SGLT1 mRNA was greater (P content of GLUT5 mRNA was greater (P content of GLUT5 mRNA in small intestinal epithelia was not affected (P > or = 0.16) by either SH infusion treatment. In contrast, GLUT2 and SGLT1 mRNA content in the ileal epithelium was increased (P content also was increased (P = 0.07) by 64% after ruminal SH infusion. These results demonstrate that the ileum of beef cattle small intestine adapts to an increased luminal supply of glucose by increasing SGLT1 and GLUT2 mRNA content, whereas increased ruminal SH supply results in duodenal upregulation of SGLT1 mRNA content. These adaptive responses of GLUT2 and SGLT1 mRNA to abomasal or ruminal SH infusion suggest that beef cattle can adapt to increase their carbohydrate assimilation through small intestinal epithelia, assuming

  8. Histone Acetylation Modifications Affect Tissue-Dependent Expression of Poplar Homologs of C4 Photosynthetic Enzyme Genes

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2017-06-01

    Full Text Available Histone modifications play important roles in regulating the expression of C4 photosynthetic genes. Given that all enzymes required for the C4 photosynthesis pathway are present in C3 plants, it has been hypothesized that this expression regulatory mechanism has been conserved. However, the relationship between histone modification and the expression of homologs of C4 photosynthetic enzyme genes has not been well determined in C3 plants. In the present study, we cloned nine hybrid poplar (Populus simonii × Populus nigra homologs of maize (Zea mays C4 photosynthetic enzyme genes, carbonic anhydrase (CA, pyruvate orthophosphate dikinase (PPDK, phosphoenolpyruvate carboxykinase (PCK, and phosphoenolpyruvate carboxylase (PEPC, and investigated the correlation between the expression levels of these genes and the levels of promoter histone acetylation modifications in four vegetative tissues. We found that poplar homologs of C4 homologous genes had tissue-dependent expression patterns that were mostly well-correlated with the level of histone acetylation modification (H3K9ac and H4K5ac determined by chromatin immunoprecipitation assays. Treatment with the histone deacetylase inhibitor trichostatin A further confirmed the role of histone acetylation in the regulation of the nine target genes. Collectively, these results suggest that both H3K9ac and H4K5ac positively regulate the tissue-dependent expression pattern of the PsnCAs, PsnPPDKs, PsnPCKs, and PsnPEPCs genes and that this regulatory mechanism seems to be conserved among the C3 and C4 species. Our findings provide new insight that will aid efforts to modify the expression pattern of these homologs of C4 genes to engineer C4 plants from C3 plants.

  9. Causes, Effects and Possible Solution of Seasonal Egg Gluts: A ...

    African Journals Online (AJOL)

    A study was conducted to assess small holder poultry farmers' perspectives on the causes, effects and solution to the cyclical egg glut in Ejigbo, Nigeria using questionnaire for data collection and descriptive data analysis. Farmers interviewed agreed that government policies have a registered effect on drop of egg sales ...

  10. Automatically Identifying Fusion Events between GLUT4 Storage Vesicles and the Plasma Membrane in TIRF Microscopy Image Sequences

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2015-01-01

    Full Text Available Quantitative analysis of the dynamic behavior about membrane-bound secretory vesicles has proven to be important in biological research. This paper proposes a novel approach to automatically identify the elusive fusion events between VAMP2-pHluorin labeled GLUT4 storage vesicles (GSVs and the plasma membrane. The differentiation is implemented to detect the initiation of fusion events by modified forward subtraction of consecutive frames in the TIRFM image sequence. Spatially connected pixels in difference images brighter than a specified adaptive threshold are grouped into a distinct fusion spot. The vesicles are located at the intensity-weighted centroid of their fusion spots. To reveal the true in vivo nature of a fusion event, 2D Gaussian fitting for the fusion spot is used to derive the intensity-weighted centroid and the spot size during the fusion process. The fusion event and its termination can be determined according to the change of spot size. The method is evaluated on real experiment data with ground truth annotated by expert cell biologists. The evaluation results show that it can achieve relatively high accuracy comparing favorably to the manual analysis, yet at a small fraction of time.

  11. Glucose Metabolism Gene Expression Patterns and Tumor Uptake of {sup 18}F-Fluorodeoxyglucose After Radiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, George D., E-mail: george.wilson@beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Thibodeau, Bryan J.; Fortier, Laura E.; Pruetz, Barbara L. [Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Galoforo, Sandra; Baschnagel, Andrew M.; Chunta, John [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Oliver Wong, Ching Yee [Department of Diagnostic Radiology and Molecular Imaging Medicine, William Beaumont Hospital, Royal Oak, Michigan (United States); Yan, Di; Marples, Brian [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Huang, Jiayi [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2014-11-01

    Purpose: To investigate whether radiation treatment influences the expression of glucose metabolism genes and compromises the potential use of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) as a tool to monitor the early response of head and neck cancer xenografts to radiation therapy (RT). Methods and Materials: Low passage head and neck squamous cancer cells (UT14) were injected to the flanks of female nu/nu mice to generate xenografts. After tumors reached a size of 500 mm{sup 3} they were treated with either sham RT or 15 Gy in 1 fraction. At different time points, days 3, 9, and 16 for controls and days 4, 7, 12, 21, 30, and 40 after irradiation, 2 to 3 mice were assessed with dynamic FDG-PET acquisition over 2 hours. Immediately after the FDG-PET the tumors were harvested for global gene expression analysis and immunohistochemical evaluation of GLUT1 and HK2. Different analytic parameters were used to process the dynamic PET data. Results: Radiation had no effect on key genes involved in FDG uptake and metabolism but did alter other genes in the HIF1α and glucose transport–related pathways. In contrast to the lack of effect on gene expression, changes in the protein expression patterns of the key genes GLUT1/SLC2A1 and HK2 were observed after radiation treatment. The changes in GLUT1 protein expression showed some correlation with dynamic FDG-PET parameters, such as the kinetic index. Conclusion: {sup 18}F-fluorodeoxyglucose positron emission tomography changes after RT would seem to represent an altered metabolic state and not a direct effect on the key genes regulating FDG uptake and metabolism.

  12. Evolutionary ancestry and novel functions of the mammalian glucose transporter (GLUT) family.

    Science.gov (United States)

    Wilson-O'Brien, Amy L; Patron, Nicola; Rogers, Suzanne

    2010-05-21

    In general, sugar porters function by proton-coupled symport or facilitative transport modes. Symporters, coupled to electrochemical energy, transport nutrients against a substrate gradient. Facilitative carriers transport sugars along a concentration gradient, thus transport is dependent upon extracellular nutrient levels. Across bacteria, fungi, unicellular non-vertebrates and plants, proton-coupled hexose symport is a crucial process supplying energy under conditions of nutrient flux. In mammals it has been assumed that evolution of whole body regulatory mechanisms would eliminate this need. To determine whether any isoforms bearing this function might be conserved in mammals, we investigated the relationship between the transporters of animals and the proton-coupled hexose symporters found in other species. We took a comparative genomic approach and have performed the first comprehensive and statistically supported phylogenetic analysis of all mammalian glucose transporter (GLUT) isoforms. Our data reveals the mammalian GLUT proteins segregate into five distinct classes. This evolutionary ancestry gives insight to structure, function and transport mechanisms within the groups. Combined with biological assays, we present novel evidence that, in response to changing nutrient availability and environmental pH, proton-coupled, active glucose symport function is maintained in mammalian cells. The analyses show the ancestry, evolutionary conservation and biological importance of the GLUT classes. These findings significantly extend our understanding of the evolution of mammalian glucose transport systems. They also reveal that mammals may have conserved an adaptive response to nutrient demand that would have important physiological implications to cell survival and growth.

  13. Scoparia dulcis (SDF7) endowed with glucose uptake properties on L6 myotubes compared insulin.

    Science.gov (United States)

    Beh, Joo Ee; Latip, Jalifah; Abdullah, Mohd Puad; Ismail, Amin; Hamid, Muhajir

    2010-05-04

    Insulin stimulates glucose uptake and promotes the translocation of glucose transporter 4 (Glut 4) to the plasma membrane on L6 myotubes. The aim of this study is to investigate affect of Scoparia dulcis Linn water extracts on glucose uptake activity and the Glut 4 translocation components (i.e., IRS-1, PI 3-kinase, PKB/Akt2, PKC and TC 10) in L6 myotubes compared to insulin. Extract from TLC fraction-7 (SDF7) was used in this study. The L6 myotubes were treated by various concentrations of SDF7 (1 to 50 microg/ml) and insulin (1 to 100 nM). The glucose uptake activities of L6 myotubes were evaluated using 2-Deoxy-D-glucose uptake assay in with or without fatty acid-induced medium. The Glut 4 translocation components in SDF7-treated L6 myotubes were detected using immunoblotting and quantified by densitometry compared to insulin. Plasma membrane lawn assay and glycogen colorimetry assay were carried out in SDF7- and insulin-treated L6 myotubes in this study. Here, our data clearly shows that SDF7 possesses glucose uptake properties on L6 myotubes that are dose-dependent, time-dependent and plasma membrane Glut 4 expression-dependent. SDF7 successfully stimulates glucose uptake activity as potent as insulin at a maximum concentration of 50 microg/ml at 480 min on L6 myotubes. Furthermore, SDF7 stimulates increased Glut 4 expression and translocation to plasma membranes at equivalent times. Even in the insulin resistance stage (free fatty acids-induced), SDF7-treated L6 myotubes were found to be more capable at glucose transport than insulin treatment. Thus, we suggested that Scoparia dulcis has the potential to be categorized as a hypoglycemic medicinal plant based on its good glucose transport properties. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  14. CD133-expressing thyroid cancer cells are undifferentiated, radioresistant and survive radioiodide therapy

    International Nuclear Information System (INIS)

    Ke, Chien-Chih; Liu, Ren-Shyan; Yang, An-Hang; Liu, Ching-Sheng; Chi, Chin-Wen; Tseng, Ling-Ming; Tsai, Yi-Fan; Ho, Jennifer H.; Lee, Chen-Hsen; Lee, Oscar K.

    2013-01-01

    131 I therapy is regularly used following surgery as a part of thyroid cancer management. Despite an overall relatively good prognosis, recurrent or metastatic thyroid cancer is not rare. CD133-expressing cells have been shown to mark thyroid cancer stem cells that possess the characteristics of stem cells and have the ability to initiate tumours. However, no studies have addressed the influence of CD133-expressing cells on radioiodide therapy of the thyroid cancer. The aim of this study was to investigate whether CD133 + cells contribute to the radioresistance of thyroid cancer and thus potentiate future recurrence and metastasis. Thyroid cancer cell lines were analysed for CD133 expression, radiosensitivity and gene expression. The anaplastic thyroid cancer cell line ARO showed a higher percentage of CD133 + cells and higher radioresistance. After γ-irradiation of the cells, the CD133 + population was enriched due to the higher apoptotic rate of CD133 - cells. In vivo 131 I treatment of ARO tumour resulted in an elevated expression of CD133, Oct4, Nanog, Lin28 and Glut1 genes. After isolation, CD133 + cells exhibited higher radioresistance and higher expression of Oct4, Nanog, Sox2, Lin28 and Glut1 in the cell line or primarily cultured papillary thyroid cancer cells, and lower expression of various thyroid-specific genes, namely NIS, Tg, TPO, TSHR, TTF1 and Pax8. This study demonstrates the existence of CD133-expressing thyroid cancer cells which show a higher radioresistance and are in an undifferentiated status. These cells possess a greater potential to survive radiotherapy and may contribute to the recurrence of thyroid cancer. A future therapeutic approach for radioresistant thyroid cancer may focus on the selective eradication of CD133 + cells. (orig.)

  15. Reprogramming energy metabolism and inducing angiogenesis: co-expression of monocarboxylate transporters with VEGF family members in cervical adenocarcinomas

    International Nuclear Information System (INIS)

    Pinheiro, Céline; Garcia, Eduardo A.; Morais-Santos, Filipa; Moreira, Marise A. R.; Almeida, Fábio M.; Jubé, Luiz F.; Queiroz, Geraldo S.; Paula, Élbio C.; Andreoli, Maria A.; Villa, Luisa L.; Longatto-Filho, Adhemar; Baltazar, Fátima

    2015-01-01

    Deregulation of cellular energetic metabolism was recently pointed out as a hallmark of cancer cells. This deregulation involves a metabolic reprogramming that leads to a high production of lactate. Lactate efflux, besides contributing for the glycolytic flux, also acts in the extracellular matrix, contributing for cancer malignancy, by, among other effects, induction of angiogenesis. However, studies on the interplay between cancer metabolism and angiogenesis are scarce. Therefore, the aim of the present study was to evaluate the metabolic and vascular molecular profiles of cervical adenocarcinomas, their co-expression, and their relation to the clinical and pathological behavior. The immunohistochemical expression of metabolism-related proteins (MCT1, MCT4, CD147, GLUT1 and CAIX) as well as VEGF family members (VEGF-A, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2 and VEGFR-3) was assessed in a series of 232 cervical adenocarcinomas. The co-expression among proteins was assessed and the expression profiles were associated with patients’ clinicopathological parameters. Among the metabolism-related proteins, MCT4 and CAIX were the most frequently expressed in cervical adenocarcinomas while CD147 was the less frequently expressed protein. Overall, VEGF family members showed a strong and extended expression with VEGF-C and VEGFR-2 as the most frequently expressed and VEGFR-1 as the less expressed member. Co-expression of MCT isoforms with VEGF family members was demonstrated. Finally, MCT4 was associated with parametrial invasion and HPV18 infection, CD147 and GLUT1 with distant metastasis, CAIX with tumor size and HPV18 infection, and VEGFR-1 with local and lymphnode metastasis. The results herein presented provide additional evidence for a crosstalk between deregulating cellular energetics and inducing angiogenesis. Also, the metabolic remodeling and angiogenic switch are relevant to cancer progression and aggressiveness in adenocarcinomas

  16. Glucose availability controls adipogenesis in mouse 3T3-L1 adipocytes via up-regulation of nicotinamide metabolism.

    Science.gov (United States)

    Jackson, Robert M; Griesel, Beth A; Gurley, Jami M; Szweda, Luke I; Olson, Ann Louise

    2017-11-10

    Expansion of adipose tissue in response to a positive energy balance underlies obesity and occurs through both hypertrophy of existing cells and increased differentiation of adipocyte precursors (hyperplasia). To better understand the nutrient signals that promote adipocyte differentiation, we investigated the role of glucose availability in regulating adipocyte differentiation and maturation. 3T3-L1 preadipocytes were grown and differentiated in medium containing a standard differentiation hormone mixture and either 4 or 25 mm glucose. Adipocyte maturation at day 9 post-differentiation was determined by key adipocyte markers, including glucose transporter 4 (GLUT4) and adiponectin expression and Oil Red O staining of neutral lipids. We found that adipocyte differentiation and maturation required a pulse of 25 mm glucose only during the first 3 days of differentiation. Importantly, fatty acids were unable to substitute for the 25 mm glucose pulse during this period. The 25 mm glucose pulse increased adiponectin and GLUT4 expression and accumulation of neutral lipids via distinct mechanisms. Adiponectin expression and other early markers of differentiation required an increase in the intracellular pool of total NAD/P. In contrast, GLUT4 protein expression was only partially restored by increased NAD/P levels. Furthermore, GLUT4 mRNA expression was mediated by glucose-dependent activation of GLUT4 gene transcription through the cis-acting GLUT4-liver X receptor element (LXRE) promoter element. In summary, this study supports the conclusion that high glucose promotes adipocyte differentiation via distinct metabolic pathways and independently of fatty acids. This may partly explain the mechanism underlying adipocyte hyperplasia that occurs much later than adipocyte hypertrophy in the development of obesity. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Increased FOXP3 expression in tumour-associated tissues of horses affected with equine sarcoid disease.

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    Mählmann, K; Hamza, E; Marti, E; Dolf, G; Klukowska, J; Gerber, V; Koch, C

    2014-12-01

    Recent studies suggest that regulatory T cells (Tregs) are associated with disease severity and progression in papilloma virus induced neoplasia. Bovine papilloma virus (BPV) is recognised as the most important aetiological factor in equine sarcoid (ES) disease. The aim of this study was to compare expression levels of Treg markers and associated cytokines in tissue samples of ES-affected equids with skin samples of healthy control horses. Eleven ES-affected, and 12 healthy horses were included in the study. Expression levels of forkhead box protein 3 (FOXP3), interleukin 10 (IL10), interleukin 4 (IL4) and interferon gamma (IFNG) mRNA in lesional and tumour-distant samples from ES-affected horses, as well as in dermal samples of healthy control horses were measured using quantitative reverse transcription polymerase chain reaction (PCR). Expression levels were compared between lesional and tumour-distant as well as between tumour-distant and control samples. Furthermore, BPV-1 E5 DNA in samples of ES-affected horses was quantified using quantitative PCR, and possible associations of viral load, disease severity and gene expression levels were evaluated. Expression levels of FOXP3, IL10 and IFNG mRNA and BPV-1 E5 copy numbers were significantly increased in lesional compared to tumour-distant samples. There was no difference in FOXP3 and cytokine expression in tumour-distant samples from ES- compared with control horses. In tumour-distant samples viral load was positively correlated with IL10 expression and severity score. The increased expression of Treg markers in tumour-associated tissues of ES-affected equids indicates a local, Treg-induced immune suppression. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Abundance in proteins expressed after functional electrical stimulation cycling or arm cycling ergometry training in persons with chronic spinal cord injury.

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    Gorgey, Ashraf S; Graham, Zachary A; Bauman, William A; Cardozo, Christopher; Gater, David R

    2017-07-01

    Longitudinal design. The study determined the effects of two forms of exercise training on the abundance of two proteins, (glucose transporter-4 [GLUT-4], adenosine monophosphate kinase [AMPK]) involved in glucose utilization and the transcriptional coactivator that regulates the genes involved in energy metabolism and mitochondrial biogenesis (peroxisome proliferator-activated receptor (PPAR) coactivator 1 alpha [PGC-1α]), in muscles in men with chronic motor-complete spinal cord injury (SCI). Clinical trial at a Medical Center. Nine men with chronic motor-complete SCI participated in functional electrical stimulation lower extremity cycling (FES-LEC; n = 4) or arm cycling ergometer (arm-cycling ergometer [ACE]; n = 5) 5 days/week for 16 weeks. Whole body composition was measured by dual energy X-ray absorptiometry. An intravenous glucose tolerance test was performed to measure glucose effectiveness (Sg) and insulin sensitivity (Si). Muscle biopsies of the right vastus lateralis (VL) and triceps muscles were collected one week prior to and post the exercise training intervention. Neither training intervention altered body composition or carbohydrate metabolism. GLUT-4 increased by 3.8 fold in the VL after FES training and increased 0.6 fold in the triceps after ACE training. PGC-1α increased by 2.3 fold in the VL after FES training and 3.8 fold in the triceps after ACE training. AMPK increased by 3.4 fold in the VL after FES training and in the triceps after ACE training. FES-LEC and ACE training were associated with greater protein expressions in the trained muscles by effectively influencing the abundance of GLUT-4, AMPK and PGC-1α. Thus, FES-LEC training of paralyzed muscle can modulate protein expression similar to that of trained and innervated muscle.

  19. 18F-fluorodeoxyglucose and PET/CT for noninvasive study of exercise-induced glucose uptake in rat skeletal muscle and tendon

    International Nuclear Information System (INIS)

    Skovgaard, Dorthe; Kjaer, Michael; El-Ali, Henrik; Kjaer, Andreas

    2009-01-01

    To investigate exercise-related glucose uptake in rat muscle and tendon using PET/CT and to study possible explanatory changes in gene expression for the glucose transporters (GLUT1 and GLUT4). The sciatic nerve in eight Wistar rats was subjected to electrostimulation to cause unilateral isometric contractions of the calf muscle. 18 F-Fluorodeoxyglucose was administered and a PET/CT scan of the hindlimbs was performed. SUVs were calculated in both Achilles tendons and the triceps surae muscles. To exclude a spill-over effect the tendons and muscles from an ex vivo group of eight rats were cut out and scanned separately (distance≥1 cm). Muscle contractions increased glucose uptake approximately sevenfold in muscles (p<0.001) and 36% in tendons (p<0.01). The ex vivo group confirmed the increase in glucose uptake in intact animals. GLUT1 and GLUT4 were expressed in both skeletal muscle and tendon, but no changes in mRNA levels could be detected. PET/CT can be used for studying glucose uptake in rat muscle and tendon in relation to muscle contractions; however, the increased uptake of glucose was not explained by changes in gene expression of GLUT1 and GLUT4. (orig.)

  20. Differential expression of growth factor receptors and membrane-bound tumor markers for imaging in male and female breast cancer.

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    Jeroen F Vermeulen

    Full Text Available INTRODUCTION: Male breast cancer accounts for 0.5-1% of all breast cancers and is generally diagnosed at higher stage than female breast cancers and therefore might benefit from earlier detection and targeted therapy. Except for HER2 and EGFR, little is known about expression of growth factor receptors in male breast cancer. We therefore investigated expression profiles of growth factor receptors and membrane-bound tumor markers in male breast cancer and gynecomastia, in comparison with female breast cancer. METHODS: Tissue microarrays containing 133 male breast cancer and 32 gynecomastia cases were stained by immunohistochemistry for a panel of membrane-bound targets and compared with data on 266 female breast cancers. RESULTS: Growth factor receptors were variably expressed in 4.5% (MET up to 38.5% (IGF1-R of male breast cancers. Compared to female breast cancer, IGF1-R and carbonic anhydrase 12 (CAXII were more frequently and CD44v6, MET and FGFR2 less frequently expressed in male breast cancer. Expression of EGFR, HER2, CAIX, and GLUT1 was not significantly different between male and female breast cancer. Further, 48.1% of male breast cancers expressed at least one and 18.0% expressed multiple growth factor receptors. Since individual membrane receptors are expressed in only half of male breast cancers, a panel of membrane markers will be required for molecular imaging strategies to reach sensitivity. A potential panel of markers for molecular imaging, consisting of EGFR, IGF1-R, FGFR2, CD44v6, CAXII, GLUT1, and CD44v6 was positive in 77% of male breast cancers, comparable to female breast cancers. CONCLUSIONS: Expression patterns of growth factor receptors and hypoxia membrane proteins in male breast cancer are different from female breast cancer. For molecular imaging strategies, a putative panel consisting of markers for EGFR, IGF1-R, FGFR2, GLUT1, CAXII, CD44v6 was positive in 77% of cases and might be considered for development of

  1. Stromal Expression of Hypoxia Regulated Proteins Is an Adverse Prognostic Factor in Colorectal Carcinomas

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    Arjen H. G. Cleven

    2007-01-01

    Full Text Available Background: Hypoxia modifies the phenotype of tumors in a way that promotes tumor aggressiveness and resistance towards chemotherapy and radiotherapy. However, the expression and influence of hypoxia-regulated proteins on tumor biology are not well characterized in colorectal tumors. We studied the role of protein expression of hypoxia-inducible factor (HIF-1α, HIF-2α, carbonic anhydrase 9 (CA9 and glucose transporter 1 (GLUT1 in patients with colorectal adenocarcinomas. Methods: Expression of HIF-1α, HIF-2α, CA9 and GLUT1 was quantified by immunohistochemistry in 133 colorectal adenocarcinomas. The expression of hypoxia markers was correlated with clinicopathological variables and overall patient survival. Results: Expression of these hypoxia markers was detected in the epithelial compartment of the tumor cells as well as in tumor-associated stromal cells. Although tumor cells frequently showed expression of one or more of the investigated hypoxia markers, no correlation among these markers or with clinical response was found. However, within the tumor stroma, positive correlations between the hypoxia markers HIF-2α, CA9 and GLUT1 were observed. Furthermore expression of HIF-2α and CA9 in tumor-associated stroma were both associated with a significantly reduced overall survival. In the Cox proportional hazard model, stromal HIF-2α expression was an independent prognostic factor for survival. Conclusion: These observations show, that expression of hypoxia regulated proteins in tumor-associated stromal cells, as opposed to their expression in epithelial tumor cells, is associated with poor outcome in colorectal cancer. This study suggests that tumor hypoxia may influence tumor-associated stromal cells in a way that ultimately contributes to patient prognosis.

  2. Evolutionary ancestry and novel functions of the mammalian glucose transporter (GLUT family

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    Patron Nicola

    2010-05-01

    Full Text Available Abstract Background In general, sugar porters function by proton-coupled symport or facilitative transport modes. Symporters, coupled to electrochemical energy, transport nutrients against a substrate gradient. Facilitative carriers transport sugars along a concentration gradient, thus transport is dependent upon extracellular nutrient levels. Across bacteria, fungi, unicellular non-vertebrates and plants, proton-coupled hexose symport is a crucial process supplying energy under conditions of nutrient flux. In mammals it has been assumed that evolution of whole body regulatory mechanisms would eliminate this need. To determine whether any isoforms bearing this function might be conserved in mammals, we investigated the relationship between the transporters of animals and the proton-coupled hexose symporters found in other species. Results We took a comparative genomic approach and have performed the first comprehensive and statistically supported phylogenetic analysis of all mammalian glucose transporter (GLUT isoforms. Our data reveals the mammalian GLUT proteins segregate into five distinct classes. This evolutionary ancestry gives insight to structure, function and transport mechanisms within the groups. Combined with biological assays, we present novel evidence that, in response to changing nutrient availability and environmental pH, proton-coupled, active glucose symport function is maintained in mammalian cells. Conclusions The analyses show the ancestry, evolutionary conservation and biological importance of the GLUT classes. These findings significantly extend our understanding of the evolution of mammalian glucose transport systems. They also reveal that mammals may have conserved an adaptive response to nutrient demand that would have important physiological implications to cell survival and growth.

  3. [Transciptome among Mexicans: a large scale methodology to analyze the genetics expression profile of simultaneous samples in muscle, adipose tissue and lymphocytes obtained from the same individual].

    Science.gov (United States)

    Bastarrachea, Raúl A; López-Alvarenga, Juan Carlos; Kent, Jack W; Laviada-Molina, Hugo A; Cerda-Flores, Ricardo M; Calderón-Garcidueñas, Ana Laura; Torres-Salazar, Amada; Torres-Salazar, Amanda; Nava-González, Edna J; Solis-Pérez, Elizabeth; Gallegos-Cabrales, Esther C; Cole, Shelley A; Comuzzie, Anthony G

    2008-01-01

    We describe the methodology used to analyze multiple transcripts using microarray techniques in simultaneous biopsies of muscle, adipose tissue and lymphocytes obtained from the same individual as part of the standard protocol of the Genetics of Metabolic Diseases in Mexico: GEMM Family Study. We recruited 4 healthy male subjects with BM1 20-41, who signed an informed consent letter. Subjects participated in a clinical examination that included anthropometric and body composition measurements, muscle biopsies (vastus lateralis) subcutaneous fat biopsies anda blood draw. All samples provided sufficient amplified RNA for microarray analysis. Total RNA was extracted from the biopsy samples and amplified for analysis. Of the 48,687 transcript targets queried, 39.4% were detectable in a least one of the studied tissues. Leptin was not detectable in lymphocytes, weakly expressed in muscle, but overexpressed and highly correlated with BMI in subcutaneous fat. Another example was GLUT4, which was detectable only in muscle and not correlated with BMI. Expression level concordance was 0.7 (p< 0.001) for the three tissues studied. We demonstrated the feasibility of carrying out simultaneous analysis of gene expression in multiple tissues, concordance of genetic expression in different tissues, and obtained confidence that this method corroborates the expected biological relationships among LEPand GLUT4. TheGEMM study will provide a broad and valuable overview on metabolic diseases, including obesity and type 2 diabetes.

  4. Clinical procedure for colon carcinoma tissue sampling directly affects the cancer marker-capacity of VEGF family members

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    Pringels, Sarah; Van Damme, Nancy; De Craene, Bram; Pattyn, Piet; Ceelen, Wim; Peeters, Marc; Grooten, Johan

    2012-01-01

    mRNA levels of members of the Vascular Endothelial Growth Factor family (VEGF-A, -B, -C, -D, Placental Growth Factor/PlGF) have been investigated as tissue-based markers of colon cancer. These studies, which used specimens obtained by surgical resection or colonoscopic biopsy, yielded contradictory results. We studied the effect of the sampling method on the marker accuracy of VEGF family members. Comparative RT-qPCR analysis was performed on healthy colon and colon carcinoma samples obtained by biopsy (n = 38) or resection (n = 39) to measure mRNA expression levels of individual VEGF family members. mRNA levels of genes encoding the eicosanoid enzymes cyclooxygenase 2 (COX2) and 5-lipoxygenase (5-LOX) and of genes encoding the hypoxia markers glucose transporter 1 (GLUT-1) and carbonic anhydrase IX (CAIX) were included as markers for cellular stress and hypoxia. Expression levels of COX2, 5-LOX, GLUT-1 and CAIX revealed the occurrence in healthy colon resection samples of hypoxic cellular stress and a concurrent increment of basal expression levels of VEGF family members. This increment abolished differential expression of VEGF-B and VEGF-C in matched carcinoma resection samples and created a surgery-induced underexpression of VEGF-D. VEGF-A and PlGF showed strong overexpression in carcinoma samples regardless of the sampling method. Sampling-induced hypoxia in resection samples but not in biopsy samples affects the marker-reliability of VEGF family members. Therefore, biopsy samples provide a more accurate report on VEGF family mRNA levels. Furthermore, this limited expression analysis proposes VEGF-A and PlGF as reliable, sampling procedure insensitive mRNA-markers for molecular diagnosis of colon cancer

  5. GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

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    Kátia C. Carvalho

    2011-01-01

    Full Text Available OBJECTIVE: To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry. INTRODUCTION: Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data. METHODS: Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types. RESULTS: Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Fortyseven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression. CONCLUSION: Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

  6. Equine Chorionic Gonadotropin Modulates the Expression of Genes Related to the Structure and Function of the Bovine Corpus Luteum.

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    Sousa, Liza Margareth Medeiros de Carvalho; Mendes, Gabriela Pacheco; Campos, Danila Barreiro; Baruselli, Pietro Sampaio; Papa, Paula de Carvalho

    2016-01-01

    We hypothesized that stimulatory and superovulatory treatments, using equine chorionic gonadotropin (eCG), modulate the expression of genes related to insulin, cellular modelling and angiogenesis signaling pathways in the bovine corpus luteum (CL). Therefore, we investigated: 1-the effect of these treatments on circulating insulin and somatomedin C concentrations and on gene and protein expression of INSR, IGF1 and IGFR1, as well as other insulin signaling molecules; 2-the effects of eCG on gene and protein expression of INSR, IGF1, GLUT4 and NFKB1A in bovine luteal cells; and 3-the effect of stimulatory and superovulatory treatments on gene and protein expression of ANG, ANGPT1, NOS2, ADM, PRSS2, MMP9 and PLAU. Serum insulin did not differ among groups (P = 0.96). However, serum somatomedin C levels were higher in both stimulated and superovulated groups compared to the control (P = 0.01). In stimulated cows, lower expression of INSR mRNA and higher expression of NFKB1A mRNA and IGF1 protein were observed. In superovulated cows, lower INSR mRNA expression, but higher INSR protein expression and higher IGF1, IGFR1 and NFKB1A gene and protein expression were observed. Expression of angiogenesis and cellular modelling pathway-related factors were as follows: ANGPT1 and PLAU protein expression were higher and MMP9 gene and protein expression were lower in stimulated animals. In superovulated cows, ANGPT1 mRNA expression was higher and ANG mRNA expression was lower. PRSS2 gene and protein expression were lower in both stimulated and superovulated animals related to the control. In vitro, eCG stimulated luteal cells P4 production as well as INSR and GLUT4 protein expression. In summary, our results suggest that superovulatory treatment induced ovarian proliferative changes accompanied by increased expression of genes providing the CL more energy substrate, whereas stimulatory treatment increased lipogenic activity, angiogenesis and plasticity of the extracellular matrix

  7. Equine Chorionic Gonadotropin Modulates the Expression of Genes Related to the Structure and Function of the Bovine Corpus Luteum.

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    Liza Margareth Medeiros de Carvalho Sousa

    Full Text Available We hypothesized that stimulatory and superovulatory treatments, using equine chorionic gonadotropin (eCG, modulate the expression of genes related to insulin, cellular modelling and angiogenesis signaling pathways in the bovine corpus luteum (CL. Therefore, we investigated: 1-the effect of these treatments on circulating insulin and somatomedin C concentrations and on gene and protein expression of INSR, IGF1 and IGFR1, as well as other insulin signaling molecules; 2-the effects of eCG on gene and protein expression of INSR, IGF1, GLUT4 and NFKB1A in bovine luteal cells; and 3-the effect of stimulatory and superovulatory treatments on gene and protein expression of ANG, ANGPT1, NOS2, ADM, PRSS2, MMP9 and PLAU. Serum insulin did not differ among groups (P = 0.96. However, serum somatomedin C levels were higher in both stimulated and superovulated groups compared to the control (P = 0.01. In stimulated cows, lower expression of INSR mRNA and higher expression of NFKB1A mRNA and IGF1 protein were observed. In superovulated cows, lower INSR mRNA expression, but higher INSR protein expression and higher IGF1, IGFR1 and NFKB1A gene and protein expression were observed. Expression of angiogenesis and cellular modelling pathway-related factors were as follows: ANGPT1 and PLAU protein expression were higher and MMP9 gene and protein expression were lower in stimulated animals. In superovulated cows, ANGPT1 mRNA expression was higher and ANG mRNA expression was lower. PRSS2 gene and protein expression were lower in both stimulated and superovulated animals related to the control. In vitro, eCG stimulated luteal cells P4 production as well as INSR and GLUT4 protein expression. In summary, our results suggest that superovulatory treatment induced ovarian proliferative changes accompanied by increased expression of genes providing the CL more energy substrate, whereas stimulatory treatment increased lipogenic activity, angiogenesis and plasticity of the

  8. Crescimento de mudas de orégano submetidas a doses e frequências de aplicação de Ácido L-glutâmico em sistema orgânico

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    M.B. Bettoni

    2014-03-01

    Full Text Available O presente trabalho teve por objetivo identificar o efeito de diferentes doses e frequências de aplicação do biofertilizante aminoácido Ácido L-glutâmico em mudas de orégano produzidas em sistema orgânico, quantificando seu crescimento. Os tratamentos compostos por 2 doses (0,4 e 0,8 mL L-1 de Ácido L-glutâmico a 30%, e testemunha com água, foram aplicados via foliar em intervalos regulares de 7 e 14 dias, por 28 dias (fatorial 3 x 2, com 4 e 2 aplicações, respectivamente, em delineamento inteiramente casualizado com 4 repetições. Aos 62 dias após a semeadura foi realizada a coleta de 8 plantas centrais por repetição para avaliação de características biométricas da parte aérea e das raízes. O experimento demonstrou que o biofertilizante aminoácido ácido L-glutâmico influenciou as características avaliadas. A dose de 0,8 mL L-1, aplicada com intervalo de 14 dias, promoveu maior crescimento das mudas de orégano.

  9. Expression of the hypoxia-inducible monocarboxylate transporter MCT4 is increased in triple negative breast cancer and correlates independently with clinical outcome

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    Doyen, J. [Department of Radiation Oncology, Centre A. Lacassagne, Nice (France); Trastour, C. [Department of Gynecology, Archet II Hospital, 06202 Nice (France); Ettore, F.; Peyrottes, I.; Toussant, N. [Department of Pathology, Centre A. Lacassagne, Nice (France); Gal, J. [Department of Medical Statistics, Centre A. Lacassagne, Nice (France); Ilc, K.; Roux, D. [Institute for Research on Cancer and Aging (IRCAN), University of Nice, Centre A. Lacassagne, 06189 Nice (France); Parks, S.K. [Centre Scientifique de Monaco (CSM) (Monaco); Ferrero, J.M. [Department of Medical Oncology, Centre A. Lacassagne, Nice (France); Pouysségur, J., E-mail: jacques.pouyssegur@unice.fr [Institute for Research on Cancer and Aging (IRCAN), University of Nice, Centre A. Lacassagne, 06189 Nice (France); Centre Scientifique de Monaco (CSM) (Monaco)

    2014-08-15

    Highlights: • Glycolytic markers are highly expressed in triple negative breast cancers. • Lactate/H{sup +} symporter MCT4 demonstrated the strongest deleterious impact on survival. • MCT4 should serve as a new prognostic factor in node-negative breast cancers. - Abstract: Background: {sup 18}Fluor-deoxy-glucose PET-scanning of glycolytic metabolism is being used for staging in many tumors however its impact on prognosis has never been studied in breast cancer. Methods: Glycolytic and hypoxic markers: glucose transporter (GLUT1), carbonic anhydrase IX (CAIX), monocarboxylate transporter 1 and 4 (MCT1, 4), MCT accessory protein basigin and lactate-dehydrogenase A (LDH-A) were assessed by immunohistochemistry in two cohorts of breast cancer comprising 643 node-negative and 127 triple negative breast cancers (TNBC) respectively. Results: In the 643 node-negative breast tumor cohort with a median follow-up of 124 months, TNBC were the most glycolytic (≈70%), followed by Her-2 (≈50%) and RH-positive cancers (≈30%). Tumoral MCT4 staining (without stromal staining) was a strong independent prognostic factor for metastasis-free survival (HR = 0.47, P = 0.02) and overall-survival (HR = 0.38, P = 0.002). These results were confirmed in the independent cohort of 127 cancer patients. Conclusion: Glycolytic markers are expressed in all breast tumors with highest expression occurring in TNBC. MCT4, the hypoxia-inducible lactate/H{sup +} symporter demonstrated the strongest deleterious impact on survival. We propose that MCT4 serves as a new prognostic factor in node-negative breast cancer and can perhaps act soon as a theranostic factor considering the current pharmacological development of MCT4 inhibitors.

  10. Processing of facial affect in social drinkers: a dose-response study of alcohol using dynamic emotion expressions.

    Science.gov (United States)

    Kamboj, Sunjeev K; Joye, Alyssa; Bisby, James A; Das, Ravi K; Platt, Bradley; Curran, H Valerie

    2013-05-01

    Studies of affect recognition can inform our understanding of the interpersonal effects of alcohol and help develop a more complete neuropsychological profile of this drug. The objective of the study was to examine affect recognition in social drinkers using a novel dynamic affect-recognition task, sampling performance across a range of evolutionarily significant target emotions and neutral expressions. Participants received 0, 0.4 or 0.8 g/kg alcohol in a double-blind, independent groups design. Relatively naturalistic changes in facial expression-from neutral (mouth open) to increasing intensities of target emotions, as well as neutral (mouth closed)-were simulated using computer-generated dynamic morphs. Accuracy and reaction time were measured and a two-high-threshold model applied to hits and false-alarm data to determine sensitivity and response bias. While there was no effect on the principal emotion expressions (happiness, sadness, fear, anger and disgust), compared to those receiving 0.8 g/kg of alcohol and placebo, participants administered with 0.4 g/kg alcohol tended to show an enhanced response bias to neutral expressions. Exploration of this effect suggested an accompanying tendency to misattribute neutrality to sad expressions following the 0.4-g/kg dose. The 0.4-g/kg alcohol-but not 0.8 g/kg-produced a limited and specific modification in affect recognition evidenced by a neutral response bias and possibly an accompanying tendency to misclassify sad expressions as neutral. In light of previous findings on involuntary negative memory following the 0.4-g/kg dose, we suggest that moderate-but not high-doses of alcohol have a special relevance to emotional processing in social drinkers.

  11. Glucose Transporters in Diabetic Kidney Disease-Friends or Foes?

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    Wasik, Anita A; Lehtonen, Sanna

    2018-01-01

    Diabetic kidney disease (DKD) is a major microvascular complication of diabetes and a common cause of end-stage renal disease worldwide. DKD manifests as an increased urinary protein excretion (albuminuria). Multiple studies have shown that insulin resistance correlates with the development of albuminuria in non-diabetic and diabetic patients. There is also accumulating evidence that glomerular epithelial cells or podocytes are insulin sensitive and that insulin signaling in podocytes is essential for maintaining normal kidney function. At the cellular level, the mechanisms leading to the development of insulin resistance include mutations in the insulin receptor gene, impairments in the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway, or perturbations in the trafficking of glucose transporters (GLUTs), which mediate the uptake of glucose into cells. Podocytes express several GLUTs, including GLUT1, GLUT2, GLUT3, GLUT4, and GLUT8. Of these, the most studied ones are GLUT1 and GLUT4, both shown to be insulin responsive in podocytes. In the basal state, GLUT4 is preferentially located in perinuclear and cytosolic vesicular structures and to a lesser extent at the plasma membrane. After insulin stimulation, GLUT4 is sorted into GLUT4-containing vesicles (GCVs) that translocate to the plasma membrane. GCV trafficking consists of several steps, including approaching of the GCVs to the plasma membrane, tethering, and docking, after which the lipid bilayers of the GCVs and the plasma membrane fuse, delivering GLUT4 to the cell surface for glucose uptake into the cell. Studies have revealed novel molecular regulators of the GLUT trafficking in podocytes and unraveled unexpected roles for GLUT1 and GLUT4 in the development of DKD, summarized in this review. These findings pave the way for better understanding of the mechanistic pathways associated with the development and progression of DKD and aid in the development of new treatments for this devastating disease.

  12. A novel role for myosin II in insulin-stimulated glucose uptake in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Steimle, Paul A.; Kent Fulcher, F.; Patel, Yashomati M.

    2005-01-01

    Insulin-stimulated glucose uptake requires the activation of several signaling pathways to mediate the translocation and fusion of GLUT4 vesicles from an intracellular pool to the plasma membrane. The studies presented here show that inhibition of myosin II activity impairs GLUT4-mediated glucose uptake but not GLUT4 translocation to the plasma membrane. We also show that adipocytes express both myosin IIA and IIB isoforms, and that myosin IIA is recruited to the plasma membrane upon insulin stimulation. Taken together, the data presented here represent the first demonstration that GLUT4-mediated glucose uptake is a myosin II-dependent process in adipocytes. Based on our findings, we hypothesize that myosin II is activated upon insulin stimulation and recruited to the cell cortex to facilitate GLUT4 fusion with the plasma membrane. The identification of myosin II as a key component of GLUT4-mediated glucose uptake represents an important advance in our understanding of the mechanisms regulating glucose homeostasis

  13. Genetic analysis of the GLUT10 glucose transporter (SLC2A10 polymorphisms in Caucasian American type 2 diabetes

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    Mychaleckyj Josyf C

    2005-12-01

    Full Text Available Abstract Background GLUT10 (gene symbol SLC2A10 is a facilitative glucose transporter within the type 2 diabetes (T2DM-linked region on chromosome 20q12-13.1. Therefore, we evaluated GLUT10 as a positional candidate gene for T2DM in Caucasian Americans. Methods Twenty SNPs including 4 coding, 10 intronic and 6 5' and 3' to the coding sequence were genotyped across a 100 kb region containing the SLC2A10 gene in DNAs from 300 T2DM cases and 310 controls using the Sequenom MassArray Genotyping System. Allelic association was evaluated, and linkage disequilibrium (LD and haplotype structure of SLC2A10 were also determined to assess whether any specific haplotypes were associated with T2DM. Results Of these variants, fifteen had heterozygosities greater than 0.80 and were analyzed further for association with T2DM. No evidence of significant association was observed for any variant with T2DM (all P ≥ 0.05, including Ala206Thr (rs2235491 which was previously reported to be associated with fasting insulin. Linkage disequilibrium analysis suggests that the SLC2A10 gene is contained in a single haplotype block of 14 kb. Haplotype association analysis with T2DM did not reveal any significant differences between haplotype frequencies in T2DM cases and controls. Conclusion From our findings, we can conclude that sequence variants in or near GLUT10 are unlikely to contribute significantly to T2DM in Caucasian Americans.

  14. Perceptual and affective mechanisms in facial expression recognition: An integrative review.

    Science.gov (United States)

    Calvo, Manuel G; Nummenmaa, Lauri

    2016-09-01

    Facial expressions of emotion involve a physical component of morphological changes in a face and an affective component conveying information about the expresser's internal feelings. It remains unresolved how much recognition and discrimination of expressions rely on the perception of morphological patterns or the processing of affective content. This review of research on the role of visual and emotional factors in expression recognition reached three major conclusions. First, behavioral, neurophysiological, and computational measures indicate that basic expressions are reliably recognized and discriminated from one another, albeit the effect may be inflated by the use of prototypical expression stimuli and forced-choice responses. Second, affective content along the dimensions of valence and arousal is extracted early from facial expressions, although this coarse affective representation contributes minimally to categorical recognition of specific expressions. Third, the physical configuration and visual saliency of facial features contribute significantly to expression recognition, with "emotionless" computational models being able to reproduce some of the basic phenomena demonstrated in human observers. We conclude that facial expression recognition, as it has been investigated in conventional laboratory tasks, depends to a greater extent on perceptual than affective information and mechanisms.

  15. Categorical Perception of Affective and Linguistic Facial Expressions

    Science.gov (United States)

    McCullough, Stephen; Emmorey, Karen

    2009-01-01

    Two experiments investigated categorical perception (CP) effects for affective facial expressions and linguistic facial expressions from American Sign Language (ASL) for Deaf native signers and hearing non-signers. Facial expressions were presented in isolation (Experiment 1) or in an ASL verb context (Experiment 2). Participants performed ABX…

  16. Eugenosedin-A improves glucose metabolism and inhibits MAPKs expression in streptozotocin/nicotinamide-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Kuo-Ping Shen

    2018-03-01

    Full Text Available This study examined the effects of eugenosedin-A (Eu-A in a streptozotocin (STZ/nicotinamide-induced rat model of type II diabetes mellitus (T2DM. Six-week-old Sprague–Dawley rats were randomly divided into three groups: (1 RD group, normal rats fed a regular diet (RD, (2 DM group, T2DM rats fed a high-fat diet, and (3 Eu-A group, T2DM rats fed a high fat diet plus oral Eu-A (5 mg/kg/day. After 30 days, the DM group had higher body weight, higher blood glucose and lower insulin levels than the RD group. The DM group also had increased protein expression of glycogen synthase kinase (GSK in liver and skeletal muscle and decreased protein expression of insulin receptor (IR, insulin receptor substrate-1 (IRS-1, IRS-2, AMP-activated protein kinase (AMPK, glucose transporter-4 (GLUT-4, glucokinase (GCK, and peroxisome proliferator-activated receptor γ (PPAR-γ. STZ/nicotinamide-induced T2DM increased the expression of mitogen-activated protein kinases (MAPKs: p38, ERK, JNK and inflammatory p65 protein. In the Eu-A treated T2DM rats, however, blood glucose was attenuated and the insulin concentration stimulated. Changes in IR, IRS-1 and IRS-2 proteins as well as AMPK, GLUT-4, GCK, GSK, PPAR-γ, MAPKs, and inflammatory p65 proteins were ameliorated. These results suggested that Eu-A alleviates STZ/nicotinamide-induced hyperglycemia by improving insulin levels and glucose metabolism, and inhibiting the MAPKs- and p65-mediated inflammatory pathway.

  17. Beetle (Ulomoides dermestoides) fat improves diabetes: effect on liver and pancreatic architecture and on PPARγ expression

    OpenAIRE

    Jasso-Villagomez, E.I.; Garcia-Lorenzana, M.; Almanza-Perez, J.C.; Fortis-Barrera, M.A.; Blancas-Flores, G.; Roman-Ramos, R.; Prado-Barragan, L.A.; Alarcon-Aguilar, F.J.

    2018-01-01

    Ulomoides dermestoides is a beetle traditionally consumed to treat diabetes. In this study, we performed a composition analysis of U. dermestoides to obtain the principal fractions, which were used to assess the effect on glycemia, liver and pancreatic architecture, and PPARγ and GLUT4 expression. Normal mice and alloxan-induced diabetic mice were administered fractions of chitin, protein or fat, and the acute hypoglycemic effect was evaluated. A subacute study involving daily administration ...

  18. Experimental study of the molecular mechanisms of myocardial ischemic memory with 18F-FDG PET/CT imaging

    International Nuclear Information System (INIS)

    Xie Boqia; Yang Minfu; Ye Jue; Yang Zihe; Dou Kefei; Tian Yi; Han Chunlei

    2012-01-01

    This study was aimed to explore whether the changes of mRNA and the existence and duration of ischemic 18 F-FDG uptake correlate with the extent of myocardial ischemia in ischemia-reperfusion canine model. The 20-minute (n= 4) and 40-minute (n=4) coronary artery occlusion followed by 24 h of open-artery reperfusion in canine model were per- formed. All dogs underwent fasting (>12 h) dynamic 18 F-FDG PET/CT and 99 Tc m -MIBI SPECT imaging at baseline, 1 h and 24 h after reperfusion. When all imaging were completed, myocardial samples from the ischemic and nonischemic region were obtained, and the mRNA expression of glucose transporter-l (GLUT-1), glucose transporter-4 (GLUT-4), and heart-fatty acid binding protein (H-FABP) were estimated by Real Time PCR. There was no difference in the ratio of hypoperfused region/nomoperfused region of 18 F-FDG up- take between the 20-minute group and 40-minute group at baseline. When examined at 1 h, increased 18 F-FDG uptake was observed in the 40-minute group. When estimated at 24 h, only the 40-minute group showed slightly higher 18 F-FDG uptake than baseline, whereas no such difference was demonstrated in the 20-minute group. Similar mRNA expression of GLUT-1, GLUT-4 and H-FABP were demonstrated in the nonischemic regions between the 2 groups, whereas increased expressions of GLUT-1 and GLUT-4, and decreased H-FABP mRNA were demonstrated in the ischemic regions. The changes of mRNA expression were more obvious in the 40 minute group than in the 20-minute group. The results showed that the existence and persistent period of ischemic 18 F-FDG uptake (ischemic memory) was correlated with the extent of myocardial ischemia. (authors)

  19. Hypoglycemia induced changes in cholinergic receptor expression in the cerebellum of diabetic rats

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    Anju TR

    2010-02-01

    Full Text Available Abstract Glucose homeostasis in humans is an important factor for the functioning of nervous system. Hypoglycemia and hyperglycemia is found to be associated with central and peripheral nerve system dysfunction. Changes in acetylcholine receptors have been implicated in the pathophysiology of many major diseases of the central nervous system (CNS. In the present study we showed the effects of insulin induced hypoglycemia and streptozotocin induced diabetes on the cerebellar cholinergic receptors, GLUT3 and muscle cholinergic activity. Results showed enhanced binding parameters and gene expression of Muscarinic M1, M3 receptor subtypes in cerebellum of diabetic (D and hypoglycemic group (D + IIH and C + IIH. α7nAchR gene expression showed a significant upregulation in diabetic group and showed further upregulated expression in both D + IIH and C + IIH group. AchE expression significantly upregulated in hypoglycemic and diabetic group. ChAT showed downregulation and GLUT3 expression showed a significant upregulation in D + IIH and C + IIH and diabetic group. AchE activity enhanced in the muscle of hypoglycemic and diabetic rats. Our studies demonstrated a functional disturbance in the neuronal glucose transporter GLUT3 in the cerebellum during insulin induced hypoglycemia in diabetic rats. Altered expression of muscarinic M1, M3 and α7nAchR and increased muscle AchE activity in hypoglycemic rats in cerebellum is suggested to cause cognitive and motor dysfunction. Hypoglycemia induced changes in ChAT and AchE gene expression is suggested to cause impaired acetycholine metabolism in the cerebellum. Cerebellar dysfunction is associated with seizure generation, motor deficits and memory impairment. The results shows that cerebellar cholinergic neurotransmission is impaired during hyperglycemia and hypoglycemia and the hypoglycemia is causing more prominent imbalance in cholinergic neurotransmission which is suggested to be a cause of cerebellar

  20. Localization and regulation of dopamine receptor D4 expression in the adult and developing rat retina

    DEFF Research Database (Denmark)

    Klitten, Laura L; Rath, Martin F; Coon, Steven L

    2008-01-01

    layers but the nocturnal increase is confined to the photoreceptors. Retinal Drd4 expression is not affected by removal of the sympathetic input to the eye, but triiodothyronine treatment induces Drd4 expression in the photoreceptors. In a developmental series, we show that the expression of Drd4...

  1. N-Methyl-D aspartate receptor-mediated effect on glucose transporter-3 levels of high glucose exposed-SH-SY5Y dopaminergic neurons.

    Science.gov (United States)

    Engin, Ayse Basak; Engin, Evren Doruk; Karakus, Resul; Aral, Arzu; Gulbahar, Ozlem; Engin, Atilla

    2017-11-01

    High glucose and insulin lead to neuronal insulin resistance. Glucose transport into the neurons is achieved by regulatory induction of surface glucose transporter-3 (GLUT3) instead of the insulin. N-methyl-D aspartate (NMDA) receptor activity increases GLUT3 expression. This study explored whether an endogenous NMDA receptor antagonist, kynurenic acid (KynA) affects the neuronal cell viability at high glucose concentrations. SH-SY5Y neuroblastoma cells were exposed to 150-250 mg/dL glucose and 40 μU/mL insulin. In KynA and N-nitro-l-arginine methyl ester (L-NAME) supplemented cultures, oxidative stress, mitochondrial metabolic activity (MTT), nitric oxide as nitrite+nitrate (NOx) and GLUT3 were determined at the end of 24 and 48-h incubation periods. Viable cells were counted by trypan blue dye. High glucose-exposed SH-SY5Y cells showed two-times more GLUT3 expression at second 24-h period. While GLUT3-stimulated glucose transport and oxidative stress was increased, total mitochondrial metabolic activity was significantly reduced. Insulin supplementation to high glucose decreased NOx synthesis and GLUT3 levels, in contrast oxidative stress increased three-fold. KynA significantly reduced oxidative stress, and increased MTT by regulating NOx production and GLUT3 expression. KynA is a noteworthy compound, as an endogenous, specific NMDA receptor antagonist; it significantly reduces oxidative stress, while increasing cell viability at high glucose and insulin concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Altered glucose transport to utero-embryonic unit in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Arnab, Banerjee; Amitabh, Krishna

    2011-02-10

    The aim of this study was to compare the changes in concentration of glucose and glucose transporters (GLUTs) in the utero-embryonic unit, consisting of decidua, trophoblast and embryo, during delayed and non-delayed periods to understand the possible cause of delayed embryonic development in Cynopterus sphinx. The results showed a significantly decreased concentration of glucose in the utero-embryonic unit due to decline in the expression of insulin receptor (IR) and GLUT 3, 4 and 8 proteins in the utero-embryonic unit during delayed period. The in vitro study showed suppressive effect of insulin on expression of GLUTs 4 and 8 in the utero-embryonic unit and a significant positive correlation between the decreased amount of glucose consumed by the utero-embryonic unit and decreased expression of GLUTs 4 (r=0.99; psphinx. Increased supply of fatty acid to the delayed embryo may be responsible for its survival under low glucose condition but unable to promote embryonic development in C. sphinx. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Expressive suppression and neural responsiveness to nonverbal affective cues.

    Science.gov (United States)

    Petrican, Raluca; Rosenbaum, R Shayna; Grady, Cheryl

    2015-10-01

    Optimal social functioning occasionally requires concealment of one's emotions in order to meet one's immediate goals and environmental demands. However, because emotions serve an important communicative function, their habitual suppression disrupts the flow of social exchanges and, thus, incurs significant interpersonal costs. Evidence is accruing that the disruption in social interactions, linked to habitual expressive suppression use, stems not only from intrapersonal, but also from interpersonal causes, since the suppressors' restricted affective displays reportedly inhibit their interlocutors' emotionally expressive behaviors. However, expressive suppression use is not known to lead to clinically significant social impairments. One explanation may be that over the lifespan, individuals who habitually suppress their emotions come to compensate for their interlocutors' restrained expressive behaviors by developing an increased sensitivity to nonverbal affective cues. To probe this issue, the present study used functional magnetic resonance imaging (fMRI) to scan healthy older women while they viewed silent videos of a male social target displaying nonverbal emotional behavior, together with a brief verbal description of the accompanying context, and then judged the target's affect. As predicted, perceivers who reported greater habitual use of expressive suppression showed increased neural processing of nonverbal affective cues. This effect appeared to be coordinated in a top-down manner via cognitive control. Greater neural processing of nonverbal cues among perceivers who habitually suppress their emotions was linked to increased ventral striatum activity, suggestive of increased reward value/personal relevance ascribed to emotionally expressive nonverbal behaviors. These findings thus provide neural evidence broadly consistent with the hypothesized link between habitual use of expressive suppression and compensatory development of increased responsiveness to

  4. Meis1 regulates Foxn4 expression during retinal progenitor cell differentiation

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    Mohammed M. Islam

    2013-09-01

    The transcription factor forkhead box N4 (Foxn4 is a key regulator in a variety of biological processes during development. In particular, Foxn4 plays an essential role in the genesis of horizontal and amacrine neurons from neural progenitors in the vertebrate retina. Although the functions of Foxn4 have been well established, the transcriptional regulation of Foxn4 expression during progenitor cell differentiation remains unclear. Here, we report that an evolutionarily conserved 129 bp noncoding DNA fragment (Foxn4CR4.2 or CR4.2, located ∼26 kb upstream of Foxn4 transcription start site, functions as a cis-element for Foxn4 regulation. CR4.2 directs gene expression in Foxn4-positive cells, primarily in progenitors, differentiating horizontal and amacrine cells. We further determined that the gene regulatory activity of CR4.2 is modulated by Meis1 binding motif, which is bound and activated by Meis1 transcription factor. Deletion of the Meis1 binding motif or knockdown of Meis1 expression abolishes the gene regulatory activity of CR4.2. In addition, knockdown of Meis1 expression diminishes the endogenous Foxn4 expression and affects cell lineage development. Together, we demonstrate that CR4.2 and its interacting Meis1 transcription factor play important roles in regulating Foxn4 expression during early retinogenesis. These findings provide new insights into molecular mechanisms that govern gene regulation in retinal progenitors and specific cell lineage development.

  5. Insulin Signaling in Liver and Adipose Tissues in Periparturient Dairy Cows Supplemented with Dietary Nicotinic Acid.

    Science.gov (United States)

    Kinoshita, Asako; Kenéz, Ákos; Locher, Lena; Meyer, Ulrich; Dänicke, Sven; Rehage, Jürgen; Huber, Korinna

    2016-01-01

    The glucose homeostasis in dairy cattle is very well controlled, in line with the metabolic adaptation during the periparturient period. Former studies showed that nicotinic acid (NA) lowered plasma non-esterified fatty acids (NEFA) concentrations and increased insulin sensitivity in dairy cows. Thus, the purpose of this study was to investigate whether the expression of proteins involved in hepatic and adipose insulin signaling and protein expression of hepatic glucose transporter 2 (GLUT2) were affected by dietary NA and dietary concentrate intake in periparturient dairy cows. Twenty pluriparous German Holstein cows were fed with the same diet from about 21 days before the expected calving date (d-21) to calving. After calving, cows were randomly assigned in 4 groups and fed with diets different in concentrate proportion ("HC" with 60:40% or "LC" with 30:70% concentrate-to-roughage ratio) and supplemented with NA (24 g/day) (NA) or without (CON) until d21. Biopsy samples were taken from the liver, subcutaneous (SCAT) and retroperitoneal (RPAT) adipose tissues at d-21 and d21. Protein expression of insulin signaling molecules (insulin receptor (INSR), phosphatidylinositol-3-kinase (PI3K), protein kinase Cζ (PKCζ)) and hepatic GLUT2 was measured by Western Blotting. The ratio of protein expression at d21/at d-21 was calculated and statistically evaluated for the effects of time and diet. Cows in HC had significantly higher dietary energy intake than cows in LC. In RPAT a decrease in PI3K and PKCζ expression was found in all groups, irrespectively of diet. In the liver, the GLUT2 expression was significantly lower in cows in NA compared with cows in CON. In conclusion, insulin signaling might be decreased in RPAT over time without any effect of diet. NA was able to modulate hepatic GLUT2 expression, but its physiological role is unclear.

  6. Insulin Signaling in Liver and Adipose Tissues in Periparturient Dairy Cows Supplemented with Dietary Nicotinic Acid.

    Directory of Open Access Journals (Sweden)

    Asako Kinoshita

    Full Text Available The glucose homeostasis in dairy cattle is very well controlled, in line with the metabolic adaptation during the periparturient period. Former studies showed that nicotinic acid (NA lowered plasma non-esterified fatty acids (NEFA concentrations and increased insulin sensitivity in dairy cows. Thus, the purpose of this study was to investigate whether the expression of proteins involved in hepatic and adipose insulin signaling and protein expression of hepatic glucose transporter 2 (GLUT2 were affected by dietary NA and dietary concentrate intake in periparturient dairy cows. Twenty pluriparous German Holstein cows were fed with the same diet from about 21 days before the expected calving date (d-21 to calving. After calving, cows were randomly assigned in 4 groups and fed with diets different in concentrate proportion ("HC" with 60:40% or "LC" with 30:70% concentrate-to-roughage ratio and supplemented with NA (24 g/day (NA or without (CON until d21. Biopsy samples were taken from the liver, subcutaneous (SCAT and retroperitoneal (RPAT adipose tissues at d-21 and d21. Protein expression of insulin signaling molecules (insulin receptor (INSR, phosphatidylinositol-3-kinase (PI3K, protein kinase Cζ (PKCζ and hepatic GLUT2 was measured by Western Blotting. The ratio of protein expression at d21/at d-21 was calculated and statistically evaluated for the effects of time and diet. Cows in HC had significantly higher dietary energy intake than cows in LC. In RPAT a decrease in PI3K and PKCζ expression was found in all groups, irrespectively of diet. In the liver, the GLUT2 expression was significantly lower in cows in NA compared with cows in CON. In conclusion, insulin signaling might be decreased in RPAT over time without any effect of diet. NA was able to modulate hepatic GLUT2 expression, but its physiological role is unclear.

  7. Hypouricemic Effects of Ganoderma applanatum in Hyperuricemia Mice through OAT1 and GLUT9

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    Tianqiao Yong

    2018-01-01

    Full Text Available Ganoderma applanatum (G. applanatum dispels wind to eliminate dampness and exhibited nephron- and liver-protective effects as noted in Chinese herbal classic literature; it might also affect hyperuricemia. Therefore, we examined the hypouricemia effects and mechanisms underlying G. applanatum on chemical-induced hyperuricemia in mice. Ethanol (GAE and water (GAW extracts were prepared by extracting G. applanatum in ethanol (GAE, followed by bathing the remains in water to yield GAW. GAE and GAW were administered orally at different doses to hyperuricemia mice, while allopurinol and benzbromarone served as positive controls. Both GAE and GAW showed remarkable hypouricemia activities, rendering a substantial decline in the SUA (serum uric acid level in hyperuricemia control (P < 0.01. Moreover, the urine uric acid (UUA levels were enhanced by GAE and GAW. In contrast to the evident renal toxicity of allopurinol, GAE and GAW did not show a distinct renal toxicity. Almost no suppressing effect was observed on the XOD activities. However, compared to the hyperuricemia control, OAT1 was elevated remarkably in mice drugged with GAE and GAW, while GLUT9 was significantly decreased. Similar to benzbromarone, GAE decreased the URAT1 protein levels significantly (P < 0.01, while GAW did not display a similar effect. GAE and GAW downregulated the level of CNT2 proteins in the gastrointestinal tract of hyperuricemia mice. Thus, G. applanatum produced outstanding hypouricemic effects, mediated by renal OAT1, GLUT9, and URAT1 and gastrointestinal CNT2 that might elevate urine uric secretions and decline in the absorption of purine in the gastrointestinal tracts. G. applanatum showed little negative influence on inner organs. By docking screening, four top-ranked compounds were identified that necessitated further investigation.Compounds: potassium oxonate, hypoxanthine, allopurinol, benzbromarone.

  8. MMSET deregulation affects cell cycle progression and adhesion regulons in t(4;14) myeloma plasma cells

    Science.gov (United States)

    Brito, Jose L.R.; Walker, Brian; Jenner, Matthew; Dickens, Nicholas J.; Brown, Nicola J.M.; Ross, Fiona M.; Avramidou, Athanasia; Irving, Julie A.E.; Gonzalez, David; Davies, Faith E.; Morgan, Gareth J.

    2009-01-01

    Background The recurrent immunoglobulin translocation, t(4;14)(p16;q32) occurs in 15% of multiple myeloma patients and is associated with poor prognosis, through an unknown mechanism. The t(4;14) up-regulates fibroblast growth factor receptor 3 (FGFR3) and multiple myeloma SET domain (MMSET) genes. The involvement of MMSET in the pathogenesis of t(4;14) multiple myeloma and the mechanism or genes deregulated by MMSET upregulation are still unclear. Design and Methods The expression of MMSET was analyzed using a novel antibody. The involvement of MMSET in t(4;14) myelomagenesis was assessed by small interfering RNA mediated knockdown combined with several biological assays. In addition, the differential gene expression of MMSET-induced knockdown was analyzed with expression microarrays. MMSET gene targets in primary patient material was analyzed by expression microarrays. Results We found that MMSET isoforms are expressed in multiple myeloma cell lines, being exclusively up-regulated in t(4;14)-positive cells. Suppression of MMSET expression affected cell proliferation by both decreasing cell viability and cell cycle progression of cells with the t(4;14) translocation. These findings were associated with reduced expression of genes involved in the regulation of cell cycle progression (e.g. CCND2, CCNG1, BRCA1, AURKA and CHEK1), apoptosis (CASP1, CASP4 and FOXO3A) and cell adhesion (ADAM9 and DSG2). Furthermore, we identified genes involved in the latter processes that were differentially expressed in t(4;14) multiple myeloma patient samples. Conclusions In conclusion, dysregulation of MMSET affects the expression of several genes involved in the regulation of cell cycle progression, cell adhesion and survival. PMID:19059936

  9. GLUT1 deficiency syndrome as a cause of encephalopathy that includes cognitive disability, treatment-resistant infantile epilepsy and a complex movement disorder.

    Science.gov (United States)

    Graham, John M

    2012-05-01

    Glucose transporter-1 (GLUT1) deficiency syndrome is caused by heterozygous mutations in the SLC2A1 gene, resulting in impaired glucose transport into the brain. It is characterized by a low glucose concentration in the cerebrospinal fluid (hypoglycorrhachia) in the absence of hypoglycemia, in combination with low to normal lactate in the cerebrospinal fluid (CSF). It often results in treatment-resistant infantile epilepsy with progressive developmental disabilities and a complex movement disorder. Recognizing GLUT1 deficiency syndrome is important, since initiation of a ketogenic diet can reduce the frequency of seizures and the severity of the movement disorder. There can be a considerable delay in diagnosing GLUT1 deficiency syndrome, and this point is illustrated by the natural history of this disorder in a 21-year-old woman with severe, progressive neurological disabilities. Her encephalopathy consisted of treatment-resistant seizures, a complex movement disorder, progressive intellectual disability, and deceleration of her head growth after late infancy. Focused evaluation at age 21 revealed GLUT1 deficiency caused by a novel heterozygous missence mutation in exon 7 (c.938C > A; p.Ser313Try) in SLC2A1 as the cause for her disabilities. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  10. Expression and Purification of Rat Glucose Transporter 1 in Pichia pastoris.

    Science.gov (United States)

    Venskutonytė, Raminta; Elbing, Karin; Lindkvist-Petersson, Karin

    2018-01-01

    Large amounts of pure and homogenous protein are a prerequisite for several biochemical and biophysical analyses, and in particular if aiming at resolving the three-dimensional protein structure. Here we describe the production of the rat glucose transporter 1 (GLUT1), a membrane protein facilitating the transport of glucose in cells. The protein is recombinantly expressed in the yeast Pichia pastoris. It is easily maintained and large-scale protein production in shaker flasks, as commonly performed in academic research laboratories, results in relatively high yields of membrane protein. The purification protocol describes all steps needed to obtain a pure and homogenous GLUT1 protein solution, including cell growth, membrane isolation, and chromatographic purification methods.

  11. Genome scan identifies a locus affecting gamma-globin expression in human beta-cluster YAC transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S.D.; Cooper, P.; Fung, J.; Weier, H.U.G.; Rubin, E.M.

    2000-03-01

    Genetic factors affecting post-natal g-globin expression - a major modifier of the severity of both b-thalassemia and sickle cell anemia, have been difficult to study. This is especially so in mice, an organism lacking a globin gene with an expression pattern equivalent to that of human g-globin. To model the human b-cluster in mice, with the goal of screening for loci affecting human g-globin expression in vivo, we introduced a human b-globin cluster YAC transgene into the genome of FVB mice . The b-cluster contained a Greek hereditary persistence of fetal hemoglobin (HPFH) g allele resulting in postnatal expression of human g-globin in transgenic mice. The level of human g-globin for various F1 hybrids derived from crosses between the FVB transgenics and other inbred mouse strains was assessed. The g-globin level of the C3HeB/FVB transgenic mice was noted to be significantly elevated. To map genes affecting postnatal g-globin expression, a 20 centiMorgan (cM) genome scan of a C3HeB/F VB transgenics [prime] FVB backcross was performed, followed by high-resolution marker analysis of promising loci. From this analysis we mapped a locus within a 2.2 cM interval of mouse chromosome 1 at a LOD score of 4.2 that contributes 10.4% of variation in g-globin expression level. Combining transgenic modeling of the human b-globin gene cluster with quantitative trait analysis, we have identified and mapped a murine locus that impacts on human g-globin expression in vivo.

  12. Diversity in the glucose transporter-4 gene (SLC2A4 in humans reflects the action of natural selection along the old-world primates evolution.

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    Eduardo Tarazona-Santos

    Full Text Available BACKGROUND: Glucose is an important source of energy for living organisms. In vertebrates it is ingested with the diet and transported into the cells by conserved mechanisms and molecules, such as the trans-membrane Glucose Transporters (GLUTs. Members of this family have tissue specific expression, biochemical properties and physiologic functions that together regulate glucose levels and distribution. GLUT4 -coded by SLC2A4 (17p13 is an insulin-sensitive transporter with a critical role in glucose homeostasis and diabetes pathogenesis, preferentially expressed in the adipose tissue, heart muscle and skeletal muscle. We tested the hypothesis that natural selection acted on SLC2A4. METHODOLOGY/PRINCIPAL FINDINGS: We re-sequenced SLC2A4 and genotyped 104 SNPs along a approximately 1 Mb region flanking this gene in 102 ethnically diverse individuals. Across the studied populations (African, European, Asian and Latin-American, all the eight common SNPs are concentrated in the N-terminal region upstream of exon 7 ( approximately 3700 bp, while the C-terminal region downstream of intron 6 ( approximately 2600 bp harbors only 6 singletons, a pattern that is not compatible with neutrality for this part of the gene. Tests of neutrality based on comparative genomics suggest that: (1 episodes of natural selection (likely a selective sweep predating the coalescent of human lineages, within the last 25 million years, account for the observed reduced diversity downstream of intron 6 and, (2 the target of natural selection may not be in the SLC2A4 coding sequence. CONCLUSIONS: We propose that the contrast in the pattern of genetic variation between the N-terminal and C-terminal regions are signatures of the action of natural selection and thus follow-up studies should investigate the functional importance of different regions of the SLC2A4 gene.

  13. Identification of a novel phosphorylation site on TBC1D4 regulated by AMP-activated protein kinase in skeletal muscle

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Taylor, Eric B.; Witczak, Carol A.

    2010-01-01

    TBC1D4 (also known as AS160) regulates GLUT4 translocation and glucose uptake in adipocytes and skeletal muscle. Its mode of action involves phosphorylation of Serine (S)/Threonine (T) residues by upstream kinases resulting in inactivation of Rab-GAP activity leading to GLUT4 mobilization...

  14. GLUT1-mediated selective tumor targeting with fluorine containing platinum(II) glycoconjugates

    OpenAIRE

    Liu, Ran; Fu, Zheng; Zhao, Meng; Gao, Xiangqian; Li, Hong; Mi, Qian; Liu, Pengxing; Yang, Jinna; Yao, Zhi; Gao, Qingzhi

    2017-01-01

    Increased glycolysis and overexpression of glucose transporters (GLUTs) are physiological characteristics of human malignancies. Based on the so-called Warburg effect, 18flurodeoxyglucose-positron emission tomography (FDG-PET) has successfully developed as clinical modality for the diagnosis and staging of many cancers. To leverage this glucose transporter mediated metabolic disparity between normal and malignant cells, in the current report, we focus on the fluorine substituted series of glu...

  15. Intratumoral Heterogeneous F 18 Fluorodeoxyglucose Uptake Corresponds with Glucose Transporter 1 and Ki-67 Expression in a Case of Krukenberg Tumor: Localization of Intratumoral Hypermetabolic Focus by Fused PET/MR

    International Nuclear Information System (INIS)

    Im, Hyung Jun; Kim, Youg il; Kim, Woo Ho; Kim, Seung Hyup; Kang, Keon Wook

    2011-01-01

    The expression of glucose transporters (Glut 1, Glut 3), Hexokinase II, and Ki-67 has been proposed to explain intratumoral heterogeneous F-18 fluorodeoxyglucose (FDG) uptake. We report a case of Krukenberg tumor with intratumoral heterogeneous FDG uptake which corresponded well with the expression tomography (PET)/magnetic resonance (MR) imaging was helpful for localizing the metabolically active area in the tumor specimen. This report elucidates the relationship between the intratumoral heterogeneous FDG uptake and biologic heterogeneity, and shows the usefulness of PET/MR in research on intratumoral heterogeneity.

  16. Vitrification affects nuclear maturation and gene expression of immature human oocytes

    Directory of Open Access Journals (Sweden)

    Abbas Shahedi

    2017-02-01

    Full Text Available Background: Vitrification of oocytes is a fast-freezing technique, which may affect the quality of the human oocyte, and consequently affects the embryo development, pregnancy and birth. The aim of the current study was to investigate the consequence of in-vitro vitrification on maturation status of immature human oocytes, additionally, expression levels of stress, and apoptosis related genes. Materials and Methods: The total of 213 human immature oocytes which routinely discarded from assisted reproduction clinics were collected and divided into two groups including: (I fresh germinal vesicle (GV oocytes (n=106 (matured in-vitro  (fIVM , and  (II GV oocytes (n=107 that initially vitrified, then matured in  in-vitro (vIVM. After 36 hours of incubation, the oocytes were evaluated for nuclear maturation and expression level of DNA methyltransferase (DNMT1, stress related genes (Sod1 and Hsp70, and apoptotic related genes (Bax and Bcl-2 by quantitative Real-Time PCR. Results: Oocyte maturation rates were reduced in vIVM compared to fIVM oocytes (P=0.001. The expression of stress (Sod1 and Hsp70, and apoptotic-related genes (Bax and Bcl-2 in vIVM were significantly higher compared to the fIVM group. Additionally, pro-apoptotic gene up-regulated 4.3 times more than anti-apoptotic gene in vIVM oocyte. However, DNMT1 gene expression was reduced in vIVM oocyte (P = 0.047. Conclusions: The low survival rate of vitrified In-vitro matured GV oocytes could definitely be explained by the alterations of their gene expression profile. 

  17. Studi Distribusi Glukosa Transporter 4 pada Otot Skelet Ayam Kedu Cemani

    OpenAIRE

    Budipitojo, Teguh; -, Ariana; Pangestiningsih, Tri Wahyu; Wijayanto, Hery; Kusindarta, Dwi Liliek; Musana, Dewi Kania

    2017-01-01

    Glucose transporter (GLUT 4) is glucose transporter protein regulated by insulin, found in adipose tissue and striated muscle (skeletal and cardiac muscle). Kedu cemani chicken is one of Indonesia endemic animal, found in Kedu, Temanggung regency, Central Java. This study was required to complete microscopic documentation of  Indonesia’s native biodiversity. The objective of this study was to clarify GLUT 4 distribution in skeletal muscle fibers of kedu cemani chicken by using avidin-biotin-p...

  18. Immunohistochemical Evaluation of Glucose Transporter Type 1 in Epithelial Dysplasia and Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Pereira, Karuza Maria Alves; Feitosa, Sthefane Gomes; Lima, Ana Thayssa Tomaz; Luna, Ealber Carvalho Macedo; Cavalcante, Roberta Barroso; de Lima, Kenio Costa; Chaves, Filipe Nobre; Costa, Fábio Wildson Gurgel

    2016-01-01

    Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity and some of these have been documented in association or preceded by oral epithelial dysplasia (OED). Aggressive cancers with fast growth have demonstrated overexpression of some glucose transporters (GLUTs). Thus, the aim of this study was to analyze the immunohistochemical expression of the glucose transporter, GLUT-1, in OEDs and OSCCs, seeking to better elucidate the biological behavior of neoplasias. Fifteen cases were selected this research of both lesions. Five areas were analyzed from each case by counting the percentage of positive cells at 400x magnification. Immunoreactivity of GLUT-1 was observed in 100% of the samples ranging from 54.2% to 86.2% for the OSCC and 73.9% to 97.4% for the OED. Statistical test revealed that there was greater overexpression of GLUT-1 in OED than the OSCC (p=0.01). It is believed the high expression of GLUT-1 may reflect the involvement of GLUT-1 in early stages of oral carcinogenesis.

  19. Affective State Level Recognition in Naturalistic Facial and Vocal Expressions.

    Science.gov (United States)

    Meng, Hongying; Bianchi-Berthouze, Nadia

    2014-03-01

    Naturalistic affective expressions change at a rate much slower than the typical rate at which video or audio is recorded. This increases the probability that consecutive recorded instants of expressions represent the same affective content. In this paper, we exploit such a relationship to improve the recognition performance of continuous naturalistic affective expressions. Using datasets of naturalistic affective expressions (AVEC 2011 audio and video dataset, PAINFUL video dataset) continuously labeled over time and over different dimensions, we analyze the transitions between levels of those dimensions (e.g., transitions in pain intensity level). We use an information theory approach to show that the transitions occur very slowly and hence suggest modeling them as first-order Markov models. The dimension levels are considered to be the hidden states in the Hidden Markov Model (HMM) framework. Their discrete transition and emission matrices are trained by using the labels provided with the training set. The recognition problem is converted into a best path-finding problem to obtain the best hidden states sequence in HMMs. This is a key difference from previous use of HMMs as classifiers. Modeling of the transitions between dimension levels is integrated in a multistage approach, where the first level performs a mapping between the affective expression features and a soft decision value (e.g., an affective dimension level), and further classification stages are modeled as HMMs that refine that mapping by taking into account the temporal relationships between the output decision labels. The experimental results for each of the unimodal datasets show overall performance to be significantly above that of a standard classification system that does not take into account temporal relationships. In particular, the results on the AVEC 2011 audio dataset outperform all other systems presented at the international competition.

  20. L-Glutamine in vitro Modulates some Immunomodulatory Properties of Bone Marrow Mesenchymal Stem Cells.

    Science.gov (United States)

    Dos Santos, Guilherme Galvão; Hastreiter, Araceli Aparecida; Sartori, Talita; Borelli, Primavera; Fock, Ricardo Ambrósio

    2017-08-01

    Glutamine (GLUT) is a nonessential amino acid that can become conditionally essential under stress conditions, being able to act in the modulation of the immune responses. Mesenchymal stem cells (MSCs) are known to their capability in the modulation of immune responses through cell-cell contact and by the secretion of soluble factors. Considering that GLUT is an immunonutrient and little is known about the influence of GLUT on the capability of MSCs to modulate immune cells, this work aims to investigate how variations in GLUT concentrations in vitro could affect some immunomodulatory properties of MSCs. In order to evaluate the effects of GLUT on MSCs immunomodulatory properties, cell proliferation rates, the expression of NFκB and STAT-3, and the production of IL-1β, IL-6, IL-10, TGF-β and TNF-α by MSCs were assessed. Based on our findings, GLUT at high doses (10 mM) augmented the proliferation of MSCs and modulated immune responses by decreasing levels of pro-inflammatory cytokines, such as IL-1β and IL-6, and by increasing levels of anti-inflammatory cytokines IL-10 and TGF-β. In addition, MSCs cultured in higher GLUT concentrations (10 mM) expressed lower levels of NF-κB and higher levels of STAT-3. Furthermore, conditioned media from MSCs cultured at higher GLUT concentrations (10 mM) reduced lymphocyte and macrophage proliferation, increased IL-10 production by both cells types, and decreased IFN-γ production by lymphocytes. Overall, this study showed that 10 mM of GLUT is able to modify immunomodulatory properties of MSCs.

  1. Hypoxia induced expression of endogenous markers in vitro is highly influenced by pH

    DEFF Research Database (Denmark)

    Sørensen, Brita Singers; Alsner, Jan; Overgaard, Jens

    2007-01-01

    BACKGROUND: Genes such as carbonic anhydrase IX (Ca9), glucose transporter 1 (Glut1), lactate dehydrogenase A (LDH-A), osteopontin (OPN) and lysyl oxidase (LOX) have been suggested as hypoxic markers, but inconsistent results suggest that factors other than oxygen influence their expression...

  2. Electrical vs manual acupuncture stimulation in a rat model of polycystic ovary syndrome: different effects on muscle and fat tissue insulin signaling.

    Directory of Open Access Journals (Sweden)

    Julia Johansson

    Full Text Available In rats with dihydrotestosterone (DHT-induced polycystic ovary syndrome (PCOS, repeated low-frequency electrical stimulation of acupuncture needles restores whole-body insulin sensitivity measured by euglycemic hyperinsulinemic clamp. We hypothesized that electrical stimulation causing muscle contractions and manual stimulation causing needle sensation have different effects on insulin sensitivity and related signaling pathways in skeletal muscle and adipose tissue, with electrical stimulation being more effective in DHT-induced PCOS rats. From age 70 days, rats received manual or low-frequency electrical stimulation of needles in abdominal and hind limb muscle five times/wk for 4-5 wks; controls were handled but untreated rats. Low-frequency electrical stimulation modified gene expression (decreased Tbc1d1 in soleus, increased Nr4a3 in mesenteric fat and protein expression (increased pAS160/AS160, Nr4a3 and decreased GLUT4 by western blot and increased GLUT4 expression by immunohistochemistry in soleus muscle; glucose clearance during oral glucose tolerance tests was unaffected. Manual stimulation led to faster glucose clearance and modified mainly gene expression in mesenteric adipose tissue (increased Nr4a3, Mapk3/Erk, Adcy3, Gsk3b, but not protein expression to the same extent; however, Nr4a3 was reduced in soleus muscle. The novel finding is that electrical and manual muscle stimulation affect glucose homeostasis in DHT-induced PCOS rats through different mechanisms. Repeated electrical stimulation regulated key functional molecular pathways important for insulin sensitivity in soleus muscle and mesenteric adipose tissue to a larger extent than manual stimulation. Manual stimulation improved whole-body glucose tolerance, an effect not observed after electrical stimulation, but did not affect molecular signaling pathways to the same extent as electrical stimulation. Although more functional signaling pathways related to insulin sensitivity

  3. SOX4 expression in bladder carcinoma

    DEFF Research Database (Denmark)

    Aaboe, Mads; Birkenkamp-Demtroder, Karin; Wiuf, Carsten

    2006-01-01

    The human transcription factor SOX4 was 5-fold up-regulated in bladder tumors compared with normal tissue based on whole-genome expression profiling of 166 clinical bladder tumor samples and 27 normal urothelium samples. Using a SOX4-specific antibody, we found that the cancer cells expressed...... in the clinical bladder material and a small subset of the genes showed a high correlation to SOX4 expression. The present data suggest a role of SOX4 in the bladder cancer disease....... the SOX4 protein and, thus, did an evaluation of SOX4 protein expression in 2,360 bladder tumors using a tissue microarray with clinical annotation. We found a correlation (P bladder cell line HU609, SOX4...

  4. Precursor Amino Acids Inhibit Polymyxin E Biosynthesis in Paenibacillus polymyxa, Probably by Affecting the Expression of Polymyxin E Biosynthesis-Associated Genes

    Directory of Open Access Journals (Sweden)

    Zhiliang Yu

    2015-01-01

    Full Text Available Polymyxin E belongs to cationic polypeptide antibiotic bearing four types of direct precursor amino acids including L-2,4-diaminobutyric acid (L-Dab, L-Leu, D-Leu, and L-Thr. The objective of this study is to evaluate the effect of addition of precursor amino acids during fermentation on polymyxin E biosynthesis in Paenibacillus polymyxa. The results showed that, after 35 h fermentation, addition of direct precursor amino acids to certain concentration significantly inhibited polymyxin E production and affected the expression of genes involved in its biosynthesis. L-Dab repressed the expression of polymyxin synthetase genes pmxA and pmxE, as well as 2,4-diaminobutyrate aminotransferase gene ectB; both L-Leu and D-Leu repressed the pmxA expression. In addition, L-Thr affected the expression of not only pmxA, but also regulatory genes spo0A and abrB. As L-Dab precursor, L-Asp repressed the expression of ectB, pmxA, and pmxE. Moreover, it affected the expression of spo0A and abrB. In contrast, L-Phe, a nonprecursor amino acid, had no obvious effect on polymyxin E biosynthesis and those biosynthesis-related genes expression. Taken together, our data demonstrated that addition of precursor amino acids during fermentation will inhibit polymyxin E production probably by affecting the expression of its biosynthesis-related genes.

  5. The effects of abnormalities of glucose homeostasis on the expression and binding of muscarinic receptors in cerebral cortex of rats.

    Science.gov (United States)

    Sherin, Antony; Peeyush, Kumar T; Naijil, George; Nandhu, Mohan Sobhana; Jayanarayanan, Sadanandan; Jes, Paul; Paulose, Cheramadathikudiyil Skaria

    2011-01-25

    Glucose homeostasis in humans is an important factor for the functioning of nervous system. Both hypo and hyperglycemia contributes to neuronal functional deficit. In the present study, effect of insulin induced hypoglycemia and streptozotocin induced diabetes on muscarinic receptor binding, cholinergic enzymes; AChE, ChAT expression and GLUT3 in the cerebral cortex of experimental rats were analysed. Total muscarinic, muscarinic M(1) receptor showed a significant decrease and muscarinic M(3) receptor subtype showed a significant increased binding in the cerebral cortex of hypoglycemic rats compared to diabetic and control. Real-Time PCR analysis of muscarinic M(1), M(3) receptor subtypes confirmed the receptor binding studies. Immunohistochemistry of muscarinic M(1), M(3) receptors using specific antibodies were also carried out. AChE and GLUT3 expression up regulated and ChAT expression down regulated in hypoglycemic rats compared to diabetic and control rats. Our results showed that hypo/hyperglycemia caused impaired glucose transport in neuronal cells as shown by altered expression of GLUT3. Increased AChE and decreased ChAT expression is suggested to alter cortical acetylcholine metabolism in experimental rats along with altered muscarinic receptor binding in hypo/hyperglycemic rats, impair cholinergic transmission, which subsequently lead to cholinergic dysfunction thereby causing learning and memory deficits. We observed a prominent cholinergic functional disturbance in hypoglycemic condition than in hyperglycemia. Hypoglycemia exacerbated the neurochemical changes in cerebral cortex induced by hyperglycemia. These findings have implications for both therapy and identification of causes contributing to neuronal dysfunction in diabetes. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Alkaline pH activates the transport activity of GLUT1 in L929 fibroblast cells.

    Science.gov (United States)

    Gunnink, Stephen M; Kerk, Samuel A; Kuiper, Benjamin D; Alabi, Ola D; Kuipers, David P; Praamsma, Riemer C; Wrobel, Kathryn E; Louters, Larry L

    2014-04-01

    The widely expressed mammalian glucose transporter, GLUT1, can be acutely activated in L929 fibroblast cells by a variety of conditions, including glucose deprivation, or treatment with various respiration inhibitors. Known thiol reactive compounds including phenylarsine oxide and nitroxyl are the fastest acting stimulators of glucose uptake, implicating cysteine biochemistry as critical to the acute activation of GLUT1. In this study, we report that in L929 cells glucose uptake increases 6-fold as the pH of the uptake solution is increased from 6 to 9 with the half-maximal activation at pH 7.5; consistent with the pKa of cysteine residues. This pH effect is essentially blocked by the pretreatment of the cells with either iodoacetamide or cinnamaldehyde, compounds that form covalent adducts with reduced cysteine residues. In addition, the activation by alkaline pH is not additive at pH 8 with known thiol reactive activators such as phenylarsine oxide or hydroxylamine. Kinetic analysis in L929 cells at pH 7 and 8 indicate that alkaline conditions both increases the Vmax and decreases the Km of transport. This is consistent with the observation that pH activation is additive to methylene blue, which activates uptake by increasing the Vmax, as well as to berberine, which activates uptake by decreasing the Km. This suggests that cysteine biochemistry is utilized in both methylene blue and berberine activation of glucose uptake. In contrast a pH increase from 7 to 8 in HCLE cells does not further activate glucose uptake. HCLE cells have a 25-fold higher basal glucose uptake rate than L929 cells and the lack of a pH effect suggests that the cysteine biochemistry has already occurred in HCLE cells. The data are consistent with pH having a complex mechanism of action, but one likely mediated by cysteine biochemistry. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Functional expression of human adenine nucleotide translocase 4 in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Takashi Hamazaki

    2011-04-01

    Full Text Available The adenine nucleotide translocase (ANT mediates the exchange of ADP and ATP across the inner mitochondrial membrane. The human genome encodes multiple ANT isoforms that are expressed in a tissue-specific manner. Recently a novel germ cell-specific member of the ANT family, ANT4 (SLC25A31 was identified. Although it is known that targeted depletion of ANT4 in mice resulted in male infertility, the functional biochemical differences between ANT4 and other somatic ANT isoforms remain undetermined. To gain insight into ANT4, we expressed human ANT4 (hANT4 in yeast mitochondria. Unlike the somatic ANT proteins, expression of hANT4 failed to complement an AAC-deficient yeast strain for growth on media requiring mitochondrial respiration. Moreover, overexpression of hANT4 from a multi-copy plasmid interfered with optimal yeast growth. However, mutation of specific amino acids of hANT4 improved yeast mitochondrial expression and supported growth of the AAC-deficient yeast on non-fermentable carbon sources. The mutations affected amino acids predicted to interact with phospholipids, suggesting the importance of lipid interactions for function of this protein. Each mutant hANT4 and the somatic hANTs exhibited similar ADP/ATP exchange kinetics. These data define common and distinct biochemical characteristics of ANT4 in comparison to ANT1, 2 and 3 providing a basis for study of its unique adaptation to germ cells.

  8. Gluts and battles: Canadian pipeline growth fear coming to U.S. markets

    International Nuclear Information System (INIS)

    Jaremko, G.

    1997-01-01

    Industry peers in the U.S.A. sounded a warning to Canadian natural gas exporters and pipeline owners about an approaching 'capacity glut' if they stay on their current aggressive expansion course. Just one of the current crop of export pipeline projects would be enough to bring on a 'displacement scenario' where delivery capacity overtakes demand and pits Canadian and American suppliers against one another for markets. These warnings were contained in a recent report by the Interstate Natural Gas Association of America. According to this report, today's pipeline projects lineup faces the American industry with the possibility of confronting a 70 per cent jump in Canadian exports to 4.9 trillion cubic feet per year by 2005, equal to 175 per cent of anticipated growth in demand. The report stresses the importance of responsible expansion of capacity based on realistic rise in demand estimates. The ball is in the industry's court to regulate itself since regulators no longer try to manage supply and demand

  9. High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling.

    Science.gov (United States)

    Gómez-Ruiz, Ana; Milagro, Fermín I; Campión, Javier; Martínez, J Alfredo; de Miguel, Carlos

    2011-04-13

    The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP) and subcutaneous (SC) adipose tissue, comparing fasted (F) to not fasted (NF) rats that had been fed a control or high-fat (HF) diet for 72 days. Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4) were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test. High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF) induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF) also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF) in animals fed either diet. In RP adipocytes of control animals, food intake (NF) decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF) did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF) decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet. Animals fed a control-diet show a normal response to food intake (NF), with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet

  10. Cycle affects imidacloprid efficiency by mediating cytochrome P450 expression in the brown planthopper Nilaparvata lugens.

    Science.gov (United States)

    Kang, K; Yang, P; Pang, R; Yue, L; Zhang, W

    2017-10-01

    Circadian clocks influence most behaviours and physiological activities in animals, including daily fluctuations in metabolism. However, how the clock gene cycle influences insects' responses to pesticides has rarely been reported. Here, we provide evidence that cycle affects imidacloprid efficacy by mediating the expression of cytochrome P450 genes in the brown planthopper (BPH) Nilaparvata lugens, a serious insect pest of rice. Survival bioassays showed that the susceptibility of BPH adults to imidacloprid differed significantly between the two time points tested [Zeitgeber Time 8 (ZT8) and ZT4]. After cloning the cycle gene in the BPH (Nlcycle), we found that Nlcycle was expressed at higher levels in the fat body and midgut, and its expression was rhythmic with two peaks. Knockdown of Nlcycle affected the expression levels and rhythms of cytochrome P450 genes as well as susceptibility to imidacloprid. The survival rates of BPH adults after treatment with imidacloprid did not significantly differ between ZT4 and ZT8 after double-stranded Nlcycle treatment. These findings can be used to improve pesticide use and increase pesticide efficiency in the field. © 2017 The Royal Entomological Society.

  11. Necrosis related HIF-1α expression predicts prognosis in patients with endometrioid endometrial carcinoma

    International Nuclear Information System (INIS)

    Seeber, Laura MS; Horrée, Nicole; Groep, Petra van der; Wall, Elsken van der; Verheijen, René HM; Diest, Paul J van

    2010-01-01

    Hypoxia inducible factor 1α (HIF-1α) plays an essential role in the adaptive response of cells to hypoxia and is associated with aggressive tumour behaviour. We have shown p27 kip1 , which is generally reduced in endometrial cancer, to be re-expressed in hypoxic regions. This possibly contributes to survival of cancer cells. The aim of this study was to evaluate the prognostic value of HIF-1α and p27 kip expression in patients with endometrioid endometrial cancer. Expression levels of HIF-1α, CAIX, Glut-1, and p27 kip1 were analyzed by immunohistochemistry. Percentage of positive cells, staining pattern (perinecrotic, diffuse, or mixed) and presence of necrosis were noted. Necrosis was correlated with shortened disease free survival (DFS) (p = 0.008) and overall survival (OS) (p = 0.045). For DFS, perinecrotic HIF-1α expression was also prognostic (p = 0.044). Moreover, high p27 kip1 expression was an additional prognostic factor for these patients with perinecrotic HIF-1α expression. In multivariate Cox regression, perinecrotic HIF-expression emerged as an independent prognostic factor. Perinecrotic HIF-1α expression was significantly associated with CAIX and Glut-1 expression, pointing towards functional HIF-1. In patients with endometrioid endometrial cancer, necrosis and necrosis-related expression of HIF-1α are important prognostic factors. More aggressive adjuvant treatment might be necessary to improve the outcome of patients with these characteristics

  12. Stability of Facial Affective Expressions in Schizophrenia

    Directory of Open Access Journals (Sweden)

    H. Fatouros-Bergman

    2012-01-01

    Full Text Available Thirty-two videorecorded interviews were conducted by two interviewers with eight patients diagnosed with schizophrenia. Each patient was interviewed four times: three weekly interviews by the first interviewer and one additional interview by the second interviewer. 64 selected sequences where the patients were speaking about psychotic experiences were scored for facial affective behaviour with Emotion Facial Action Coding System (EMFACS. In accordance with previous research, the results show that patients diagnosed with schizophrenia express negative facial affectivity. Facial affective behaviour seems not to be dependent on temporality, since within-subjects ANOVA revealed no substantial changes in the amount of affects displayed across the weekly interview occasions. Whereas previous findings found contempt to be the most frequent affect in patients, in the present material disgust was as common, but depended on the interviewer. The results suggest that facial affectivity in these patients is primarily dominated by the negative emotions of disgust and, to a lesser extent, contempt and implies that this seems to be a fairly stable feature.

  13. d-Fructose Modification Enhanced Internalization of Mixed Micelles in Breast Cancer Cells via GLUT5 Transporters.

    Science.gov (United States)

    Zhou, Xu; Qin, Xianyan; Gong, Tao; Zhang, Zhi-Rong; Fu, Yao

    2017-07-01

    d-Fructose modified poly(ε-caprolactone)-polyethylene glycol (PCL-PEG-Fru) diblock amphiphile is synthesized via Cu(I)-catalyzed click chemistry, which self-assembles with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) into PCL-PEG-Fru/TPGS mixed micelles (PPF MM). It has been proven that glucose transporter (GLUT)5 is overexpressed in MCF-7 cells other than L929 cells. In this study, PPF MM exhibit a significantly higher uptake efficiency than fructose-free PCL-PEG-N 3 /TPGS mixed micelles in both 2D MCF-7 cells and 3D tumor spheroids. Also, the presence of free d-fructose competitively inhibits the internalization of PPF MM in MCF-7 cells other than L929 cells. PPF MM show selective tumor accumulation in MCF-7 breast tumor bearing mice xenografts. Taken together, PPF MM represent a promising nanoscale carrier system to achieve GLUT5-mediated cell specific delivery in cancer therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Vasopressin-dependent short-term regulation of aquaporin 4 expressed in Xenopus oocytes

    DEFF Research Database (Denmark)

    Moeller, H B; Fenton, R A; Zeuthen, T

    2009-01-01

    Aquaporin 4 (AQP4) is abundantly expressed in the perivascular glial endfeet in the central nervous system (CNS), where it is involved in the exchange of fluids between blood and brain. At this location, AQP4 contributes to the formation and/or the absorption of the brain edema that may arise...... following pathologies such as brain injuries, brain tumours, and cerebral ischemia. As vasopressin and its G-protein-coupled receptor (V1(a)R) have been shown to affect the outcome of brain edema, we have investigated the regulatory interaction between AQP4 and V1(a)R by heterologous expression in Xenopus......)R may prove to be a potential therapeutic target in the prevention and treatment of brain edema....

  15. Leptin modulates human Sertoli cells acetate production and glycolytic profile: a novel mechanism of obesity-induced male infertility?

    Science.gov (United States)

    Martins, Ana D; Moreira, Ana C; Sá, Rosália; Monteiro, Mariana P; Sousa, Mário; Carvalho, Rui A; Silva, Branca M; Oliveira, Pedro F; Alves, Marco G

    2015-09-01

    Human feeding behavior and lifestyle are gradually being altered, favoring the development of metabolic diseases, particularly type 2 diabetes and obesity. Leptin is produced by the adipose tissue acting as a satiety signal. Its levels have been positively correlated with fat mass and hyperleptinemia has been proposed to negatively affect male reproductive function. Nevertheless, the molecular mechanisms by which this hormone affects male fertility remain unknown. Herein, we hypothesize that leptin acts on human Sertoli cells (hSCs), the "nurse cells" of spermatogenesis, altering their metabolism. To test our hypothesis, hSCs were cultured without or with leptin (5, 25 and 50ng/mL). Leptin receptor was identified by qPCR and Western blot. Protein levels of glucose transporters (GLUT1, GLUT2 and GLUT3), phosphofructokinase, lactate dehydrogenase (LDH) and monocarboxylate transporter 4 (MCT4) were determined by Western Blot. LDH activity was assessed and metabolite production/consumption determined by proton nuclear magnetic resonance. Oxidative damage was evaluated by assessing lipid peroxidation, protein carbonilation and nitration. Our data shows that leptin receptor is expressed in hSCs. The concentration of leptin found in lean, healthy patients, upregulated GLUT2 protein levels and concentrations of leptin found in lean and obese patients increased LDH activity. Of note, all leptin concentrations decreased hSCs acetate production illustrating a novel mechanism for this hormone action. Moreover, our data shows that leptin does not induce or protect hSCs from oxidative damage. We report that this hormone modulates the nutritional support of spermatogenesis, illustrating a novel mechanism that may be linked to obesity-induced male infertility. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. CyclinD1, CDK4, and P21 expression by IEC-6 cells in response to NiTi alloy and polymeric biomaterials

    International Nuclear Information System (INIS)

    Wang, Zhanhui; Yan, Jun; Zheng, Qi; Wang, Zhigang

    2012-01-01

    In order to investigate how cells recognize biomaterials, mRNA that was expressed in attached Intestinal epithelial cells (IEC-6) on various suture substrates was evaluated. The expressed cell cycle regulators (cyclin D1, CDK4 and p21) mRNA were then isolated and detected using the real time- polymerase chain reaction (PCR) method. As a result, cyclin D1 gene expression was affected by cell-polymer adhesion and was associated with cell proliferation. In addition, CDK4 gene expression was affected by cell proliferation rather than by cell-biomaterial interaction. The p21 mRNA gene expression was higher in cells on more hydrophilic surfaces than on hydrophobic surfaces. Further, the cyclin D1, CDK4 and p21 gene expression were also influenced by the surface chemistry of suture materials. We concluded that the expression of cyclin D1, CDK4 and p21 mRNA was a powerful method for studying cell-biomaterial interactions or the evaluation of the carcinogenic activity of biomaterials. - Highlights: ►We evaluated the effects of biomaterials on the cyclin D1, CDK4 and p21 expression. ►Cell-polymer adhesion and cell proliferation affected cyclin D1 and CDK4 expression. ►The p21 expression was higher on more hydrophilic surfaces than on hydrophobic. ►They were also influenced by surface chemistry of biomaterials.

  17. Gene Expression Profiles in Paired Gingival Biopsies from Periodontitis-Affected and Healthy Tissues Revealed by Massively Parallel Sequencing

    Science.gov (United States)

    Båge, Tove; Lagervall, Maria; Jansson, Leif; Lundeberg, Joakim; Yucel-Lindberg, Tülay

    2012-01-01

    Periodontitis is a chronic inflammatory disease affecting the soft tissue and bone that surrounds the teeth. Despite extensive research, distinctive genes responsible for the disease have not been identified. The objective of this study was to elucidate transcriptome changes in periodontitis, by investigating gene expression profiles in gingival tissue obtained from periodontitis-affected and healthy gingiva from the same patient, using RNA-sequencing. Gingival biopsies were obtained from a disease-affected and a healthy site from each of 10 individuals diagnosed with periodontitis. Enrichment analysis performed among uniquely expressed genes for the periodontitis-affected and healthy tissues revealed several regulated pathways indicative of inflammation for the periodontitis-affected condition. Hierarchical clustering of the sequenced biopsies demonstrated clustering according to the degree of inflammation, as observed histologically in the biopsies, rather than clustering at the individual level. Among the top 50 upregulated genes in periodontitis-affected tissues, we investigated two genes which have not previously been demonstrated to be involved in periodontitis. These included interferon regulatory factor 4 and chemokine (C-C motif) ligand 18, which were also expressed at the protein level in gingival biopsies from patients with periodontitis. In conclusion, this study provides a first step towards a quantitative comprehensive insight into the transcriptome changes in periodontitis. We demonstrate for the first time site-specific local variation in gene expression profiles of periodontitis-affected and healthy tissues obtained from patients with periodontitis, using RNA-seq. Further, we have identified novel genes expressed in periodontitis tissues, which may constitute potential therapeutic targets for future treatment strategies of periodontitis. PMID:23029519

  18. Investigation of SLC6A4 gene expression in autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Elif Funda Şener

    2015-06-01

    Full Text Available Objective: Autism is defined as a complex neurodevelopmental disorder. Genetics plays a major role in the etiology of autism spectrum disorders (ASD. The role of the serotonin in the development of autism has been widely investigated. SLC6A4 gene (SERT or 5-HT has an important role reuptaking of serotonin. Because of this, our study examined the expression level of SLC6A4 gene in autism patients. Methods: Thirty-four patients (26 male, 8 female who diagnosed as autism firstly according to DSM-V criteria in the Department of child psychiatry, Erciyes University Medical Faculty and healthy 23 controls (16 male, 7 female were enrolled in this study. Total RNA was isolated from peripheral blood samples using TRIzol. Quantitative Real-time PCR (qRT-PCR was performed to detect SLC6A4 gene expression. Results: SLC6A4 gene expression was found statistically significant and low in autism group compared with controls (p=0,027. Conclusion: The low gene expression in the patient group implied that there is an abnormality of serotonin reuptake. According to our results, we suggest that much more studies may be planned with the expression and methylation profile of this gene combined with gene polymorphisms especially affecting the expression in larger sample sizes. J Clin Exp Invest 2015; 6 (2: 165-169

  19. Mastication markedly affects mandibular condylar cartilage growth, gene expression, and morphology.

    Science.gov (United States)

    Enomoto, Akiko; Watahiki, Junichi; Nampo, Tomoki; Irie, Tarou; Ichikawa, Yuuta; Tachikawa, Tetsuhiko; Maki, Koutaro

    2014-09-01

    Mandibular growth is believed to be strongly related to mastication. Furthermore, mandibular condylar cartilage is known to be derived from neural crest cells. We examined whether the degree of chewing affects condylar cartilage growth of the mandible. Mice were fed diets with varying hardness. Genes specific to neural crest-derived cells were measured by real-time polymerase chain reaction to compare the expression changes between the mandibular and tibia cartilages. The mandibular condylar cartilage was then evaluated histologically, and proliferation was evaluated using proliferating cell nuclear antigen. Immunostaining was conducted for osteopontin, type X collagen, and Musashi1, and real-time polymerase chain reaction was used to assess the expression levels of osteopontin and type X collagen. Markers including P75, Wnt-1, Musashi1, and Nestin were upregulated in the mandibular condylar cartilage as compared with the tibial cartilage. Histologic assessment of the mandibular cartilage showed that the hypertrophic chondrocyte zone was statistically significantly thicker in mice fed a hard diet. Chondrocyte proliferation and Musashi1 expression were lower in mice fed a hard diet. After 4 weeks, numerous osteopontin and type X collagen-positive cells were observed in mice fed a mixed diet. Mastication affects the balance between differentiation and proliferation in the mandibular condylar cartilage. This phenomenon might be attributed to the presence of neural crest-derived cells. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  20. Short-term impact of a classical ketogenic diet on gut microbiota in GLUT1 Deficiency Syndrome: A 3-month prospective observational study.

    Science.gov (United States)

    Tagliabue, Anna; Ferraris, Cinzia; Uggeri, Francesca; Trentani, Claudia; Bertoli, Simona; de Giorgis, Valentina; Veggiotti, Pierangelo; Elli, Marina

    2017-02-01

    The classical ketogenic diet (KD) is a high-fat, very low-carbohydrate normocaloric diet used for drug-resistant epilepsy and Glucose Transporter 1 Deficiency Syndrome (GLUT1 DS). In animal models, high fat diet induces large alterations in microbiota producing deleterious effects on gut health. We carried out a pilot study on patients treated with KD comparing their microbiota composition before and after three months on the diet. Six patients affected by GLUT1 DS were asked to collect fecal samples before and after three months on the diet. RT - PCR analysis was performed in order to quantify Firmicutes, Bacteroidetes, Bifidobacterium spp., Lactobacillus spp., Clostridium perfringens, Enterobacteriaceae, Clostridium cluster XIV, Desulfovibrio spp. and Faecalibacterium prausnitzii. Compared with baseline, there were no statistically significant differences at 3 months in Firmicutes and Bacteroidetes. However fecal microbial profiles revealed a statistically significant increase in Desulfovibrio spp. (p = 0.025), a bacterial group supposed to be involved in the exacerbation of the inflammatory condition of the gut mucosa associated to the consumption of fats of animal origin. A future prospective study on the changes in gut microbiota of all children with epilepsy started on a KD is warranted. In patients with dysbiosis demonstrated by fecal samples, it my be reasonable to consider an empiric trial of pre or probiotics to potentially restore the «ecological balance» of intestinal microbiota. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  1. Characteristics of [18F] fluorodeoxyglucose uptake in human colon cancer cells

    International Nuclear Information System (INIS)

    Kim, Chae Kyun; Chung, June Key; Jeong, Jae Min; Lee, Myung Chul; Koh, Chang Soon

    1997-01-01

    Cancer tissues are characterized by increased glucose uptake. 18 F-fluorodeoxyglucose(FDG), a glucose analogue is used for the diagnosis of cancer in PET studies. This study was aimed to compare the glucose uptake and glucose transporter 1(GLUT1) expression in various human colon cancer cells. We measured FDG uptake by cell retention study and expression of GLUT1 using Western blotting. Human colon cancer cells, SNU-C2A, SNU-C4 and SNU-C5, were used. The cells were incubated with 1μ Ci/ml of FDG in HEPES- buffered saline for one hour. The FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were 16.8±1.36, 12.3±5.55 and 61.0±2.17 cpm/μg of protein, respectively. Dose-response and time-course studies represent that FDG uptake of cancer cells were dose dependent and time dependent. The rate of FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were 0.29±0.03, 0.21±0.09 and 1.07±0.07 cpm/min/μg of protein, respectively. Western blot analysis showed that the GLUT1 expression of SNU-C5 was significantly higher than those of SNU-C2A and SNU-C4. These results represent that FDG uptake into human colon cancer cells are different from each other. In addition, FDG uptake and expression of GLUT1 are closely related in human colon cancer cells

  2. TRPM4 protein expression in prostate cancer

    DEFF Research Database (Denmark)

    Berg, Kasper Drimer; Soldini, Davide; Jung, Maria

    2016-01-01

    BACKGROUND: Transient receptor potential cation channel, subfamily M, member 4 (TRPM4) messenger RNA (mRNA) has been shown to be upregulated in prostate cancer (PCa) and might be a new promising tissue biomarker. We evaluated TRPM4 protein expression and correlated the expression level.......79-2.62; p = 0.01-0.03 for the two observers) when compared to patients with a lower staining intensity. CONCLUSIONS: TRPM4 protein expression is widely expressed in benign and cancerous prostate tissue, with highest staining intensities found in PCa. Overexpression of TRPM4 in PCa (combination of high...

  3. Representing affective facial expressions for robots and embodied conversational agents by facial landmarks

    NARCIS (Netherlands)

    Liu, C.; Ham, J.R.C.; Postma, E.O.; Midden, C.J.H.; Joosten, B.; Goudbeek, M.

    2013-01-01

    Affective robots and embodied conversational agents require convincing facial expressions to make them socially acceptable. To be able to virtually generate facial expressions, we need to investigate the relationship between technology and human perception of affective and social signals. Facial

  4. In vitro culture of bovine embryos in murine ES cell conditioned media negatively affects expression of pluripotency-related markers OCT4, SOX2 and SSEA1.

    Science.gov (United States)

    Oliveira, C S; de Souza, M M; Saraiva, N Z; Tetzner, T A D; Lima, M R; Lopes, F L; Garcia, J M

    2012-06-01

    Despite extensive efforts, establishment of bovine embryonic stem (ES) cell lines has not been successful. We hypothesized that culture conditions for in vitro-produced (IVP) embryos, the most used source of inner cell mass (ICM) to obtain ES cells, might affect their undifferentiated state. Therefore, the aim of this work was to improve pluripotency of IVP blastocysts to produce suitable ICM for further culturing. We tested KSR and foetal calf serum (FCS) supplements in SOF medium and ES cell conditioned medium (CM) on IVC (groups: KSR, KSR CM, FCS and FCS CM). Cleavage and blastocyst rates were similar between all groups. Also, embryonic quality, assessed by apoptosis rates (TUNEL assay), total cell number and ICM percentage did not differ between experimental groups. However, expression of pluripotency-related markers was affected. We detected down-regulation of OCT3/4, SOX2 and SSEA1 in ICM of FCS CM blastocysts (p < 0.05). SOX2 gene expression revealed lower levels (p < 0.05) on KSR CM blastocysts and a remarkable variation in SOX2 mRNA levels on FCS-supplemented blastocysts. In conclusion, pluripotency-related markers tend to decrease after supplementation with ES cell CM, suggesting different mechanisms regulating mouse and bovine pluripotency. KSR supplementation did not differ from FCS, but FCS replacement by KSR may produce blastocysts with stable SOX2 gene expression levels. © 2011 Blackwell Verlag GmbH.

  5. Altered Expression of the Malate-Permeable Anion Channel OsALMT4 Reduces the Growth of Rice Under Low Radiance

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2018-05-01

    Full Text Available We examined the function of OsALMT4 in rice (Oryza sativa L. which is a member of the aluminum-activated malate transporter family. Previous studies showed that OsALMT4 localizes to the plasma membrane and that expression in transgenic rice lines results in a constitutive release of malate from the roots. Here, we show that OsALMT4 is expressed widely in roots, shoots, flowers, and grain but not guard cells. Expression was also affected by ionic and osmotic stress, light and to the hormones ABA, IAA, and salicylic acid. Malate efflux from the transgenic plants over-expressing OsALMT4 was inhibited by niflumate and salicylic acid. Growth of transgenic lines with either increased OsALMT4 expression or reduced expression was measured in different environments. Light intensity caused significant differences in growth between the transgenic lines and controls. When day-time light was reduced from 700 to 300 μmol m-2s-1 independent transgenic lines with either increased or decreased OsALMT4 expression accumulated less biomass compared to their null controls. This response was not associated with differences in photosynthetic capacity, stomatal conductance or sugar concentrations in tissues. We propose that by disrupting malate fluxes across the plasma membrane carbon partitioning and perhaps signaling are affected which compromises growth under low light. We conclude that OsALMT4 is expressed widely in rice and facilitates malate efflux from different cell types. Altering OsALMT4 expression compromises growth in low-light environments.

  6. Expression of the Transcription Factor E4BP4 in Human Basophils

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Gohr, Maria; Poulsen, Lars Kærgaard

    2014-01-01

    Rationale The cytokine IL-3 plays an important role for human basophil development, function and survival. IL-3 is also reported to induce the expression of the transcription factor E4BP4, but it is not known whether E4BP4 is expressed in basophils and influences basophil responsiveness. The aim...... by Alcian blue. RNA was extracted (0.005-0.02 µg RNA from 0.5 - 1 x 106 cells), and the corresponding cDNA analyzed by real-time PCR where E4BP4 expression was calculated as 2-(CT(E4BP4) - CT(β-actin)). E4BP4 protein expression was visualized in basophil lysates (107 cells/ml) by Western blot followed...... the transcription factor E4BP4 which might have an impact on basophil histamine release....

  7. Psoriatic T cells reduce epidermal turnover time and affect cell proliferation contributed from differential gene expression.

    Science.gov (United States)

    Li, Junqin; Li, Xinhua; Hou, Ruixia; Liu, Ruifeng; Zhao, Xincheng; Dong, Feng; Wang, Chunfang; Yin, Guohua; Zhang, Kaiming

    2015-09-01

    Psoriasis is mediated primarily by T cells, which reduce epidermal turnover time and affect keratinocyte proliferation. We aimed to identify differentially expressed genes (DEG) in T cells from normal, five pairs of monozygotic twins concordant or discordant for psoriasis, to determine whether these DEG may account for the influence to epidermal turnover time and keratinocyte proliferation. The impact of T cells on keratinocyte proliferation and epidermal turnover time were investigated separately by immunohistochemistry and cultured with (3) H-TdR. mRNA expression patterns were investigated by RNA sequencing and verified by real-time reverse transcription polymerase chain reaction. After co-culture with psoriatic T cells, the expression of Ki-67, c-Myc and p53 increased, while expression of Bcl-2 and epidermal turnover time decreased. There were 14 DEG which were found to participate in the regulation of cell proliferation or differentiation. Psoriatic T cells exhibited the ability to decrease epidermal turnover time and affect keratinocyte proliferation because of the differential expression of PPIL1, HSPH1, SENP3, NUP54, FABP5, PLEKHG3, SLC9A9 and CHCHD4. © 2015 Japanese Dermatological Association.

  8. Temporal Changes in Cortical and Hippocampal Expression of Genes Important for Brain Glucose Metabolism Following Controlled Cortical Impact Injury in Mice

    Directory of Open Access Journals (Sweden)

    June Zhou

    2017-09-01

    Full Text Available Traumatic brain injury (TBI causes transient increases and subsequent decreases in brain glucose utilization. The underlying molecular pathways are orchestrated processes and poorly understood. In the current study, we determined temporal changes in cortical and hippocampal expression of genes important for brain glucose/lactate metabolism and the effect of a known neuroprotective drug telmisartan on the expression of these genes after experimental TBI. Adult male C57BL/6J mice (n = 6/group underwent sham or unilateral controlled cortical impact (CCI injury. Their ipsilateral and contralateral cortex and hippocampus were collected 6 h, 1, 3, 7, 14, 21, and 28 days after injury. Expressions of several genes important for brain glucose utilization were determined by qRT-PCR. In results, (1 mRNA levels of three key enzymes in glucose metabolism [hexo kinase (HK 1, pyruvate kinase, and pyruvate dehydrogenase (PDH] were all increased 6 h after injury in the contralateral cortex, followed by decreases at subsequent times in the ipsilateral cortex and hippocampus; (2 capillary glucose transporter Glut-1 mRNA increased, while neuronal glucose transporter Glut-3 mRNA decreased, at various times in the ipsilateral cortex and hippocampus; (3 astrocyte lactate transporter MCT-1 mRNA increased, whereas neuronal lactate transporter MCT-2 mRNA decreased in the ipsilateral cortex and hippocampus; (4 HK2 (an isoform of hexokinase expression increased at all time points in the ipsilateral cortex and hippocampus. GPR81 (lactate receptor mRNA increased at various time points in the ipsilateral cortex and hippocampus. These temporal alterations in gene expression corresponded closely to the patterns of impaired brain glucose utilization reported in both TBI patients and experimental TBI rodents. The observed changes in hippocampal gene expression were delayed and prolonged, when compared with those in the cortex. The patterns of alterations were specific

  9. Dihydrotestosterone deteriorates cardiac insulin signaling and glucose transport in the rat model of polycystic ovary syndrome.

    Science.gov (United States)

    Tepavčević, Snežana; Vojnović Milutinović, Danijela; Macut, Djuro; Žakula, Zorica; Nikolić, Marina; Božić-Antić, Ivana; Romić, Snježana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

    2014-05-01

    It is supposed that women with polycystic ovary syndrome (PCOS) are prone to develop cardiovascular disease as a consequence of multiple risk factors that are mostly related to the state of insulin resistance and consequent hyperinsulinemia. In the present study, we evaluated insulin signaling and glucose transporters (GLUT) in cardiac cells of dihydrotestosterone (DHT) treated female rats as an animal model of PCOS. Expression of proteins involved in cardiac insulin signaling pathways and glucose transporters, as well as their phosphorylation or intracellular localization were studied by Western blot analysis in DHT-treated and control rats. Treatment with DHT resulted in increased body mass, absolute mass of the heart, elevated plasma insulin concentration, dyslipidemia and insulin resistance. At the molecular level, DHT treatment did not change protein expression of cardiac insulin receptor and insulin receptor substrate 1, while phosphorylation of the substrate at serine 307 was increased. Unexpectedly, although expression of downstream Akt kinase and its phosphorylation at threonine 308 were not altered, phosphorylation of Akt at serine 473 was increased in the heart of DHT-treated rats. In contrast, expression and phosphorylation of extracellular signal regulated kinases 1/2 were decreased. Plasma membrane contents of GLUT1 and GLUT4 were decreased, as well as the expression of GLUT4 in cardiac cells at the end of androgen treatment. The obtained results provide evidence for alterations in expression and especially in functional characteristics of insulin signaling molecules and glucose transporters in the heart of DHT-treated rats with PCOS, indicating impaired cardiac insulin action. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Clinicopathologic Significance of CXCL12 and CXCR4 Expressions in Patients with Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Naomi Yoshuantari

    2018-01-01

    Full Text Available Background. Colorectal cancer (CRC is both a global and national burden, being the third most common malignancy in men and the second in women, worldwide. The prognosis of CRC is affected by various factors like the histological grade, angiolymphatic invasion, and distant metastases. Metastasis is an intricate process; one of the possible mechanisms is through the interaction of the chemokines CXCL12 and CXCR4. This study aims to reveal the expression patterns of CXCL12 and CXCR4 in CRC. Methods. The quantitative expressions of CXCL12 and CXCR4 messenger RNA (mRNA were evaluated in 32 patients with adenocarcinoma-type CRC. Real-time polymerase chain reaction (qRT-PCR was performed on formalin-fixed tissues. CXCL12 and CXCR4’s expressions, clinicopathologic features, and the treatment response to the CRC were analysed. Results. All tumour tissues showed higher levels of both chemokines compared to normal colonic tissue. The expression of CXCL12 mRNA was higher in rectal location (p=0.04 with a tendency to be higher in later stages (p=0.15, while the expression of CXCR4 was lower in tumours with a lymphatic invasion (p=0.02, compared to their counterparts. There was no difference in the expression of CXCL12 and CXCR4 according to the patients’ ages, gender, tumour differentiation, or response to chemotherapy. Conclusion. Our study demonstrated that the mRNA expression of CXCL12 was significantly correlated with rectal location. CXCR4 mRNA expression was inversely correlated in tumours with a lymphatic invasion.

  11. False positive {sup 18}F-FDG PET in an ischial chondroblastoma; an analysis of glucose transporter 1 and hexokinase II expression

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Kenichiro [Osaka University Graduate School of Medicine, Department of Nuclear Medicine and Tracer Kinetics, Osaka (Japan); Osaka University Graduate School of Medicine, Department of Orthopaedics, Osaka (Japan); Ueda, Takafumi; Tamai, Noriyuki; Myoui, Akira; Yoshikawa, Hideki [Osaka University Graduate School of Medicine, Department of Orthopaedics, Osaka (Japan); Tomita, Yasuhiko; Aozasa, Katsuyuki [Osaka University Graduate School of Medicine, Pathology, Osaka (Japan); Higuchi, Ichiro; Hatazawa, Jun [Osaka University Graduate School of Medicine, Department of Nuclear Medicine and Tracer Kinetics, Osaka (Japan); Inoue, Atsuo [Osaka University Graduate School of Medicine, Radiology, Osaka (Japan)

    2006-05-15

    We report a rare case of chondroblastoma arising from the ischium which showed an increased {sup 18}F-FDG uptake. Chondroblastoma is an uncommon lesion and usually involves the epiphysis of long bones. However, in this case, the tumor appeared as a well-defined osteolytic lesion in the ischium on radiographs. MR imaging demonstrated two components in the tumor: a solid one and a multilobular cystic component. {sup 18}F-FDG PET imaging revealed an increased uptake in the ischium. The {sup 18}F-FDG uptake resembled the results observed in malignant bone tumors. A histological diagnosis of chondroblastoma was obtained from tissue of an open biopsy. An immunohistochemical analysis demonstrated weak expression of both Glut-1 and HK-II. These findings suggest that Glut-1 and HK-II expression are not strongly related to FDG uptake in chondroblastoma. (orig.)

  12. Differential expression of ID4 and its association with TP53 mutation, SOX2, SOX4 and OCT-4 expression levels.

    Directory of Open Access Journals (Sweden)

    Thais Fernanda de Almeida Galatro

    Full Text Available Inhibitor of DNA Binding 4 (ID4 is a member of the helix-loop-helix ID family of transcription factors, mostly present in the central nervous system during embryonic development, that has been associated with TP53 mutation and activation of SOX2. Along with other transcription factors, ID4 has been implicated in the tumorigenic process of astrocytomas, contributing to cell dedifferentiation, proliferation and chemoresistance. In this study, we aimed to characterize the ID4 expression pattern in human diffusely infiltrative astrocytomas of World Health Organization (WHO grades II to IV of malignancy (AGII-AGIV; to correlate its expression level to that of SOX2, SOX4, OCT-4 and NANOG, along with TP53 mutational status; and to correlate the results with the clinical end-point of overall survival among glioblastoma patients. Quantitative real time PCR (qRT-PCR was performed in 130 samples of astrocytomas for relative expression, showing up-regulation of all transcription factors in tumor cases. Positive correlation was found when comparing ID4 relative expression of infiltrative astrocytomas with SOX2 (r = 0.50; p<0.005, SOX4 (r = 0.43; p<0.005 and OCT-4 (r = 0.39; p<0.05. The results from TP53 coding exon analysis allowed comparisons between wild-type and mutated status only in AGII cases, demonstrating significantly higher levels of ID4, SOX2 and SOX4 in mutated cases (p<0.05. This pattern was maintained in secondary GBM and further confirmed by immunohistochemistry, suggesting a role for ID4, SOX2 and SOX4 in early astrocytoma tumorigenesis. Combined hyperexpression of ID4, SOX4 and OCT-4 conferred a much lower (6 months median survival than did hypoexpression (18 months. Because both ID4 alone and a complex of SOX4 and OCT-4 activate SOX2 transcription, it is possible that multiple activation of SOX2 impair the prognosis of GBM patients. These observational results of associated expression of ID4 with SOX4 and OCT-4 may be used as a

  13. Transport, metabolism, and endosomal trafficking-dependent regulation of intestinal fructose absorption

    Science.gov (United States)

    Patel, Chirag; Douard, Veronique; Yu, Shiyan; Gao, Nan; Ferraris, Ronaldo P.

    2015-01-01

    Dietary fructose that is linked to metabolic abnormalities can up-regulate its own absorption, but the underlying regulatory mechanisms are not known. We hypothesized that glucose transporter (GLUT) protein, member 5 (GLUT5) is the primary fructose transporter and that fructose absorption via GLUT5, metabolism via ketohexokinase (KHK), as well as GLUT5 trafficking to the apical membrane via the Ras-related protein-in-brain 11 (Rab11)a-dependent endosomes are each required for regulation. Introducing fructose but not lysine and glucose solutions into the lumen increased by 2- to 10-fold the heterogeneous nuclear RNA, mRNA, protein, and activity levels of GLUT5 in adult wild-type mice consuming chow. Levels of GLUT5 were >100-fold that of candidate apical fructose transporters GLUTs 7, 8, and 12 whose expression, and that of GLUT 2 and the sodium-dependent glucose transporter protein 1 (SGLT1), was not regulated by luminal fructose. GLUT5-knockout (KO) mice exhibited no facilitative fructose transport and no compensatory increases in activity and expression of SGLT1 and other GLUTs. Fructose could not up-regulate GLUT5 in GLUT5-KO, KHK-KO, and intestinal epithelial cell-specific Rab11a-KO mice. The fructose-specific metabolite glyceraldehyde did not increase GLUT5 expression. GLUT5 is the primary transporter responsible for facilitative absorption of fructose, and its regulation specifically requires fructose uptake and metabolism and normal GLUT5 trafficking to the apical membrane.—Patel, C., Douard, V., Yu, S., Gao, N., Ferraris, R. P. Transport, metabolism, and endosomal trafficking-dependent regulation of intestinal fructose absorption. PMID:26071406

  14. Expression of cartilage developmental genes in Hoxc8- and Hoxd4-transgenic mice.

    Directory of Open Access Journals (Sweden)

    Claudia Kruger

    2010-02-01

    Full Text Available Hox genes encode transcription factors, which regulate skeletal patterning and chondrocyte differentiation during the development of cartilage, the precursor to mature bone. Overexpression of the homeobox transcription factors Hoxc8 and Hoxd4 causes severe cartilage defects due to delay in cartilage maturation. Matrix metalloproteinases (MMPs, bone morphogenetic proteins (BMPs and fibroblastic growth factors (FGFs are known to play important roles in skeletal development and endochondral bone formation and remodeling. In order to investigate whether these molecules are aberrantly expressed in Hoxc8- and/or Hoxd4-transgenic cartilage, we performed quantitative RT-PCR on chondrocytes from Hox-transgenic mice. Gene expression levels of Bmp4, Fgf8, Fgf10, Mmp9, Mmp13, Nos3, Timp3, Wnt3a and Wnt5a were altered in Hoxc8-transgenic chondrocytes, and Fgfr3, Ihh, Mmp8, and Wnt3a expression levels were altered in Hoxd4-transgenic chondrocytes, respectively. Notably, Wnt3a expression was elevated in Hoxc8- and reduced in Hoxd4-transgenic cartilage. These results suggest that both transcription factors affect cartilage maturation through different molecular mechanisms, and provide the basis for future studies into the role of these genes and possible interactions in pathogenesis of cartilage defects in Hoxc8- and Hoxd4-transgenic mice.

  15. Fanconi Bickel Syndrome: Novel Mutations in GLUT 2 Gene Causing a Distinguished Form of Renal Tubular Acidosis in Two Unrelated Egyptian Families

    Directory of Open Access Journals (Sweden)

    Mohammad Al-Haggar

    2011-01-01

    Full Text Available Background. Fanconi-Bickel syndrome (FBS is an autosomal recessive disorder caused by defects in facilitative glucose transporter 2 (GLUT2 or SLC2A2 gene mapped on chromosome 3q26.1-26.3, that codes for the glucose transporter protein 2. Methods. Two unrelated Egyptian families having suspected cases of FBS were enrolled after taking a written informed consent; both had positive consanguinity, and index cases had evidences of proximal renal tubular defects with hepatomegaly; they were subjected to history taking, signs of rickets as well as anthropometric measurements. Laboratory workup included urinalysis, renal and liver function tests including fasting and postprandial blood sugar; serum calcium, phosphorus, alkaline phosphatase, sodium and potassium, lipid profile, and detailed blood gas. Imaging including bone survey and abdominal ultrasound, and liver biopsy were done to confirm diagnosis. Molecular analysis of the GLUT2 gene was done for DNA samples extracted from peripheral blood leukocyte. All coding sequences, including flanking introns in GLUT2 gene, were amplified using PCR followed by direct sequencing. Results. Two new mutations had been detected, one in each family, in exon 3 two bases (GA were deleted (c.253 254delGA and in exon 6 in the second family, G-to-C substitution at position-1 of the splicing acceptor site (c.776-1G>C or IVS5-1G>A. Conclusion. FBS is a rare disease due to mutation in GLUT2 gene; many mutations were reported, about half were novel mutations; yet none of these mutations is more frequent. A more extensive survey for the most frequent mutations among FBS has to be contemplated to allow for use of molecular screening tests like ARMS.

  16. Putting Yourself on the Line: Self-Esteem and Expressing Affection in Romantic Relationships.

    Science.gov (United States)

    Luerssen, Anna; Jhita, Gugan Jote; Ayduk, Ozlem

    2017-07-01

    Although expressing affection is an important way to connect to a romantic partner, it also involves putting yourself on the line-revealing dependence on your partner. Extending the risk-regulation model, we hypothesized that individuals with lower self-esteem (SE), who are concerned about vulnerability in relationships, experience less rewarding reactions to expressing affection, and believe that their partners respond less positively to receiving affection. We assessed these predictions across two studies that measured retrospective reports, reactions to an in vivo exchange and responses in daily life. We found that participants with lower SE expressed less affection and experienced less positive emotional, cognitive, and physiological reactions when doing so. Participants with lower SE believed that their partners derived fewer benefits from their affection despite that their partners experienced normative boosts in positive emotion and relationship satisfaction during these exchanges. The consequences of these findings for relationship functioning and SE are discussed.

  17. 12038_2016_9616_Supplementary 1..4

    Indian Academy of Sciences (India)

    homeostasis, autoimmunity, responses to infection, cancers and inflammation. ... CD40+CD4+T cells involved in type-I diabetes through binding of Gal-9 with CD40. ... ForssmanGlycosphingolipid; FOXP3: Forkhead Box P3; GLUT 2: Glucose.

  18. NOX4 mediates BMP4-induced upregulation of TRPC1 and 6 protein expressions in distal pulmonary arterial smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Qian Jiang

    Full Text Available Our previous studies demonstrated that bone morphogenetic protein 4 (BMP4 mediated, elevated expression of canonical transient receptor potential (TRPC largely accounts for the enhanced proliferation in pulmonary arterial smooth muscle cells (PASMCs. In the present study, we sought to determine the signaling pathway through which BMP4 up-regulates TRPC expression.We employed recombinant human BMP4 (rhBMP4 to determine the effects of BMP4 on NADPH oxidase 4 (NOX4 and reactive oxygen species (ROS production in rat distal PASMCs. We also designed small interfering RNA targeting NOX4 (siNOX4 and detected whether NOX4 knockdown affects rhBMP4-induced ROS, TRPC1 and 6 expression, cell proliferation and intracellular Ca2+ determination in PASMCs.In rhBMP4 treated rat distal PASMCs, NOX4 expression was (226.73±11.13 %, and the mean ROS level was (123.65±1.62 % of that in untreated control cell. siNOX4 transfection significantly reduced rhBMP4-induced elevation of the mean ROS level in PASMCs. Moreover, siNOX4 transfection markedly reduced rhBMP4-induced elevation of TRPC1 and 6 proteins, basal [Ca2+]i and SOCE. Furthermore, compared with control group (0.21±0.001, the proliferation of rhBMP4 treated cells was significantly enhanced (0.41±0.001 (P<0.01. However, such increase was attenuated by knockdown of NOX4. Moreover, external ROS (H2O2 100 µM, 24 h rescued the effects of NOX4 knockdown, which included the declining of TRPC1 and 6 expression, basal intracellular calcium concentration ([Ca2+]i and store-operated calcium entry (SOCE, suggesting that NOX4 plays as an important mediator in BMP4-induced proliferation and intracellular calcium homeostasis.These results suggest that BMP4 may increase ROS level, enhance TRPC1 and 6 expression and proliferation by up-regulating NOX4 expression in PASMCs.

  19. Macrophage activation and differentiation signals regulate schlafen-4 gene expression: evidence for Schlafen-4 as a modulator of myelopoiesis.

    Directory of Open Access Journals (Sweden)

    Wendy J van Zuylen

    Full Text Available BACKGROUND: The ten mouse and six human members of the Schlafen (Slfn gene family all contain an AAA domain. Little is known of their function, but previous studies suggest roles in immune cell development. In this report, we assessed Slfn regulation and function in macrophages, which are key cellular regulators of innate immunity. METHODOLOGY/PRINCIPAL FINDINGS: Multiple members of the Slfn family were up-regulated in mouse bone marrow-derived macrophages (BMM by the Toll-like Receptor (TLR4 agonist lipopolysaccharide (LPS, the TLR3 agonist Poly(I∶C, and in disease-affected joints in the collagen-induced model of rheumatoid arthritis. Of these, the most inducible was Slfn4. TLR agonists that signal exclusively through the MyD88 adaptor protein had more modest effects on Slfn4 mRNA levels, thus implicating MyD88-independent signalling and autocrine interferon (IFN-β in inducible expression. This was supported by the substantial reduction in basal and LPS-induced Slfn4 mRNA expression in IFNAR-1⁻/⁻ BMM. LPS causes growth arrest in macrophages, and other Slfn family genes have been implicated in growth control. Slfn4 mRNA levels were repressed during macrophage colony-stimulating factor (CSF-1-mediated differentiation of bone marrow progenitors into BMM. To determine the role of Slfn4 in vivo, we over-expressed the gene specifically in macrophages in mice using a csf1r promoter-driven binary expression system. Transgenic over-expression of Slfn4 in myeloid cells did not alter macrophage colony formation or proliferation in vitro. Monocyte numbers, as well as inflammatory macrophages recruited to the peritoneal cavity, were reduced in transgenic mice that specifically over-expressed Slfn4, while macrophage numbers and hematopoietic activity were increased in the livers and spleens. CONCLUSIONS: Slfn4 mRNA levels were up-regulated during macrophage activation but down-regulated during differentiation. Constitutive Slfn4 expression in the

  20. Oracle Application Express 4 Recipes

    CERN Document Server

    Zehoo, Edmund

    2011-01-01

    Oracle Application Express 4 Recipes provides an example-based approach to learning Application Express - the ground-breaking, rapid application development platform included with every Oracle Database license. The recipes format is ideal for the quick-study who just wants a good example or two to kick start their thinking and get pointed in the right direction. The recipes cover the gamut of Application Express development. Author and Application Express expert Edmund Zehoo shows how to create data entry screens, visualize data in the form of reports and charts, implement validation and back-

  1. Activity-Dependent Regulation of Surface Glucose Transporter-3

    OpenAIRE

    Ferreira, Jainne M.; Burnett, Arthur L.; Rameau, Gerald A.

    2011-01-01

    Glucose transporter 3 (GLUT3) is the main facilitative glucose transporter in neurons. Glucose provides neurons with a critical energy source for neuronal activity. However, the mechanism by which neuronal activity controls glucose influx via GLUT3 is unknown. We investigated the influence of synaptic stimulation on GLUT3 surface expression and glucose import in primary cultured cortical and hippocampal neurons. Synaptic activity increased surface expression of GLUT3 leading to an elevation o...

  2. Role of chrysin on expression of insulin signaling molecules

    Directory of Open Access Journals (Sweden)

    Kottireddy Satyanarayana

    2015-01-01

    Full Text Available Background: Currently available drugs are unsuccessful for the treatment of tye-2 diabetes due to their adverseside-effects. Hence, a search for novel drugs, especially ofplant origin, continues. Chrysin (5,7-dihydroxyflavone is a flavonoid, natural component of traditional medicinal herbs, present in honey, propolis and many plant extracts that hasbeen used in traditional medicine around the world to treat numerous ailments. Objective: The present study was aimed to identify the protective role of chrysin on the expression of insulin-signaling molecules in the skeletal muscle of high fat and sucrose-induced type-2 diabetic adult male rats. Materials and Methods: The oral effective dose of chrysin (100 mg/kg body weight was given once a day until the end of the study (30 days post-induction of diabetes to high fat diet-induced diabetic rats.At the end of the experimental period, fasting blood glucose, oral glucose tolerance, serum lipid profile, lipid peroxidation (LPO and free radical generation, as well as the levels of insulin signaling molecules and tissue glycogen in the gastrocnemius muscle were assessed. Results: Diabetic rats showed impaired glucose tolerance and impairment in insulin signaling molecules (IR, IRS-1, p-IRS-1Tyr 632 , p- Akt Thr308 , glucose transporter subtype 4 [GLUT4] proteins and glycogen concentration. Serum insulin, lipid profile, LPO and free radical generation were found to be increased in diabetic control rats.The treatment with chrysin normalized the altered levels of blood glucose, serum insulin, lipid profile, LPO and insulin signaling molecules as well as GLUT4 proteins. Conclusion: Our present findings indicate that chrysin improves glycemic control through activation of insulin signal transduction in the gastrocnemius muscle of high fat and sucrose-induced type-2 diabetic male rats.

  3. Supplementation of pyruvate prevents palmitate-induced impairment of glucose uptake in C2 myotubes.

    Science.gov (United States)

    Jung, Jong Gab; Choi, Sung-E; Hwang, Yoon-Jung; Lee, Sang-A; Kim, Eun Kyoung; Lee, Min-Seok; Han, Seung Jin; Kim, Hae Jin; Kim, Dae Jung; Kang, Yup; Lee, Kwan-Woo

    2011-10-15

    Elevated fatty acid levels have been thought to contribute to insulin resistance. Repression of the glucose transporter 4 (GLUT4) gene as well as impaired GLUT4 translocation may be a mediator for fatty acid-induced insulin resistance. This study was initiated to determine whether palmitate treatment repressed GLUT4 expression, whether glucose/fatty acid metabolism influenced palmitate-induced GLUT4 gene repression (PIGR), and whether attempts to prevent PIGR restored palmitate-induced impairment of glucose uptake (PIIGU) in C2 myotubes. Not only stimulators of fatty acid oxidation, such as bezafibrate, AICAR, and TOFA, but also TCA cycle substrates, such as pyruvate, leucine/glutamine, and α-ketoisocaproate/monomethyl succinate, significantly prevented PIGR. In particular, supplementing with pyruvate through methyl pyruvate resulted in nearly complete prevention of PIIGU, whereas palmitate treatment reduced the intracellular pyruvate level. These results suggest that pyruvate depletion plays a critical role in PIGR and PIIGU; thus, pyruvate supplementation may help prevent obesity-induced insulin resistance in muscle cells. Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Peroxireduxin-4 is Over-Expressed in Colon Cancer and its Down-Regulation Leads to Apoptosis

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    Sandra M. Leydold

    2011-01-01

    Full Text Available The objective of this study was to gain insight into the biological basis of colon cancer progression by characterizing gene expression differences between normal colon epithelium, corresponding colorectal primary tumors and metastases. We found a close similarity in gene expression patterns between primary tumors and metastases, indicating a correlation between gene expression and morphological characteristics. PRDX4 was identified as highly expressed both in primary colon tumors and metastases, and selected for further characterization. Our study revealed that “Prdx4” (PrxIV, AOE372 shows functional similarities to other Prx family members by negatively affecting apoptosis induction in tumor cells. In addition, our study links Prdx4 with Hif-1α, a key regulatory factor of angiogenesis. Targeting Prdx4 may be an attractive approach in cancer therapy, as its inhibition is expected to lead to induction of apoptosis and blockage of Hif-1α-mediated tumor angiogenesis.

  5. The K-Ras 4A isoform promotes apoptosis but does not affect either lifespan or spontaneous tumor incidence in aging mice

    International Nuclear Information System (INIS)

    Plowman, Sarah J.; Arends, Mark J.; Brownstein, David G.; Luo Feijun; Devenney, Paul S.; Rose, Lorraine; Ritchie, Ann-Marie; Berry, Rachel L.; Harrison, David J.; Hooper, Martin L.; Patek, Charles E.

    2006-01-01

    Ras proteins function as molecular switches in signal transduction pathways, and, here, we examined the effects of the K-ras4A and 4B splice variants on cell function by comparing wild-type embryonic stem (ES) cells with K-ras tmΔ4A/tmΔ4A (exon 4A knock-out) ES cells which express K-ras4B only and K-ras -/- (exons 1-3 knock-out) ES cells which express neither splice variant, and intestinal epithelium from wild-type and K-ras tmΔ4A/tmΔ4A mice. RT-qPCR analysis found that K-ras4B expression was reduced in K-ras tmΔ4A/tmΔ4A ES cells but unaffected in small intestine. K-Ras deficiency did not affect ES cell growth, and K-Ras4A deficiency did not affect intestinal epithelial proliferation. K-ras tmΔ4A/tmΔ4A and K-ras -/- ES cells showed a reduced capacity for differentiation following LIF withdrawal, and K-ras -/- cells were least differentiated. K-Ras4A deficiency inhibited etoposide-induced apoptosis in ES cells and intestinal epithelial cells. However, K-ras tmΔ4A/tmΔ4A ES cells were more resistant to etoposide-induced apoptosis than K-ras -/- cells. The results indicate that (1) K-Ras4A promotes apoptosis while K-Ras4B inhibits it, and (2) K-Ras4B, and possibly K-Ras4A, promotes differentiation. The findings raise the possibility that alteration of the K-Ras4A/4B isoform ratio modulates tumorigenesis by differentially affecting stem cell survival and/or differentiation. However, K-Ras4A deficiency did not affect life expectancy or spontaneous overall tumor incidence in aging mice

  6. Metabolic and behavioral effects of ractopamine at continuous low levels in rats under stress

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    Edna Lopes

    2015-06-01

    Full Text Available This study aimed at evaluating the effect of ractopamine (RAC on metabolism, zootechnical performance, body composition, and behavior in Wistar rats submitted to acute and chronic restrain stress. The oral dose of 5 mg/kg of RAC was administered in periods of 0, 7, 14, 21, and 28 days. The elevated plus-maze test (EPMT was used for behavioral assessment. Blood, carcass and viscera characteristics were evaluated. Insulin-dependent glucose transporters (GLUT-4 were semi-quantified by Western Blot in epididymal adipocytes. RAC periods associated with chronic stress increased the GLUT-4 protein expression in adipose tissue in a time-dependent manner (P=0.01, i.e., the longer the RAC addition period, the higher the GLUT-4 concentration in chronically stressed animals (0=1.42; 7=1.19; 14=2.03; 21=1.59; 28=2.35. The stress periods combined with RAC increased the time spent in the opened arms of the maze (Chronic stress: 0=10.6; 7=8.7; 14=5.9; 21=12.3; 28=4.0; Acute stress 0=3.1; 7= 4.7; 14=7.5; 21=0.0; 28=2.8 (P=0.04. Chronic (entries on the closed arms [ECA]=3.60 and acute (ECA=3.80 stress reduced locomotive activity in the maze (P=0.03. The results suggested that stress could negatively affect the possible benefits offered by the RAC, mainly impairing the adipose tissue metabolism and behavior in the animals.

  7. Through the eyes of a child: preschoolers' identification of emotional expressions from the child affective facial expression (CAFE) set.

    Science.gov (United States)

    LoBue, Vanessa; Baker, Lewis; Thrasher, Cat

    2017-08-10

    Researchers have been interested in the perception of human emotional expressions for decades. Importantly, most empirical work in this domain has relied on controlled stimulus sets of adults posing for various emotional expressions. Recently, the Child Affective Facial Expression (CAFE) set was introduced to the scientific community, featuring a large validated set of photographs of preschool aged children posing for seven different emotional expressions. Although the CAFE set was extensively validated using adult participants, the set was designed for use with children. It is therefore necessary to verify that adult validation applies to child performance. In the current study, we examined 3- to 4-year-olds' identification of a subset of children's faces in the CAFE set, and compared it to adult ratings cited in previous research. Our results demonstrate an exceptionally strong relationship between adult ratings of the CAFE photos and children's ratings, suggesting that the adult validation of the set can be applied to preschool-aged participants. The results are discussed in terms of methodological implications for the use of the CAFE set with children, and theoretical implications for using the set to study the development of emotion perception in early childhood.

  8. TRPC4α and TRPC4β Similarly Affect Neonatal Cardiomyocyte Survival during Chronic GPCR Stimulation.

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    Nadine Kirschmer

    Full Text Available The Transient Receptor Potential Channel Subunit 4 (TRPC4 has been considered as a crucial Ca2+ component in cardiomyocytes promoting structural and functional remodeling in the course of pathological cardiac hypertrophy. TRPC4 assembles as homo or hetero-tetramer in the plasma membrane, allowing a non-selective Na+ and Ca2+ influx. Gαq protein-coupled receptor (GPCR stimulation is known to increase TRPC4 channel activity and a TRPC4-mediated Ca2+ influx which has been regarded as ideal Ca2+ source for calcineurin and subsequent nuclear factor of activated T-cells (NFAT activation. Functional properties of TRPC4 are also based on the expression of the TRPC4 splice variants TRPC4α and TRPC4β. Aim of the present study was to analyze cytosolic Ca2+ signals, signaling, hypertrophy and vitality of cardiomyocytes in dependence on the expression level of either TRPC4α or TRPC4β. The analysis of Ca2+ transients in neonatal rat cardiomyocytes (NRCs showed that TRPC4α and TRPC4β affected Ca2+ cycling in beating cardiomyocytes with both splice variants inducing an elevation of the Ca2+ transient amplitude at baseline and TRPC4β increasing the Ca2+ peak during angiotensin II (Ang II stimulation. NRCs infected with TRPC4β (Ad-C4β also responded with a sustained Ca2+ influx when treated with Ang II under non-pacing conditions. Consistent with the Ca2+ data, NRCs infected with TRPC4α (Ad-C4α showed an elevated calcineurin/NFAT activity and a baseline hypertrophic phenotype but did not further develop hypertrophy during chronic Ang II/phenylephrine stimulation. Down-regulation of endogenous TRPC4α reversed these effects, resulting in less hypertrophy of NRCs at baseline but a markedly increased hypertrophic enlargement after chronic agonist stimulation. Ad-C4β NRCs did not exhibit baseline calcineurin/NFAT activity or hypertrophy but responded with an increased calcineurin/NFAT activity after GPCR stimulation. However, this effect was not

  9. Glucose stimulates neurotensin secretion from the rat small intestine by mechanisms involving SGLT1 and GLUT2 leading to cell depolarization and calcium influx

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Bechmann, Louise Ellegaard; Hartmann, Bolette

    2015-01-01

    of secretion. Luminal glucose (20% wt/vol) stimulated secretion but vascular glucose (5, 10, or 15 mmol/l) was without effect. The underlying mechanisms depend on membrane depolarization and calcium influx, since the voltage-gated calcium channel inhibitor nifedipine and the KATP channel opener diazoxide......, suggesting that glucose stimulates secretion by initial uptake by this transporter. However, secretion was also sensitive to GLUT2 inhibition (by phloretin) and blockage of oxidative phosphorylation (2-4-dinitrophenol). Direct KATP channel closure by sulfonylureas stimulated secretion. Therefore, glucose...

  10. Spatial memory impairment is associated with hippocampal insulin signals in ovariectomized rats.

    Science.gov (United States)

    Wang, Fang; Song, Yan-Feng; Yin, Jie; Liu, Zi-Hua; Mo, Xiao-Dan; Wang, De-Gui; Gao, Li-Ping; Jing, Yu-Hong

    2014-01-01

    Estrogen influences memory formation and insulin sensitivity. Meanwhile, glucose utilization directly affects learning and memory, which are modulated by insulin signals. Therefore, this study investigated whether or not the effect of estrogen on memory is associated with the regulatory effect of this hormone on glucose metabolism. The relative expression of estrogen receptor β (ERβ) and glucose transporter type 4 (GLUT4) in the hippocampus of rats were evaluated by western blot. Insulin level was assessed by ELISA and quantitative RT-PCR, and spatial memory was tested by the Morris water maze. Glucose utilization in the hippocampus was measured by 2-NBDG uptake analysis. Results showed that ovariectomy impaired the spatial memory of rats. These impairments are similar as the female rats treated with the ERβ antagonist tamoxifen (TAM). Estrogen blockade by ovariectomy or TAM treatment obviously decreased glucose utilization. This phenomenon was accompanied by decreased insulin level and GLUT4 expression in the hippocampus. The female rats were neutralized with hippocampal insulin with insulin antibody, which also impaired memory and local glucose consumption. These results indicated that estrogen blockade impaired the spatial memory of the female rats. The mechanisms by which estrogen blockade impaired memory partially contributed to the decline in hippocampal insulin signals, which diminished glucose consumption.

  11. What is Driving Global Imbalances? The Global Savings Glut Hypothesis Reexamined

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    Jai-Won Ryou

    2009-12-01

    Full Text Available In the middle of the global financial crisis, global imbalances seem to have been resolved to some extent, but it remains to be seen whether these imbalances will emerge again along with economic recovery. In order to cope with this global issue, we need to clarify what caused global imbalances in the first place. This paper aims to evaluate the relative importance of the "global savings glut" to the U.S. external imbalances. Drawing on the portfolio balance model, we analyze how the process of interaction between the U.S. current account deficit, capital inflows, and the U.S. dollar exchange rate is linked to domestic and external factors. Our empirical analysis shows that the U.S. current account deficit maintained since the early 1990s is mainly driven by the domestic factors, such as a decrease in the U.S. national savings and an increase in money supply growth. The size of the negative effect of a "global savings glut" measured by an increase in the East Asian countries' national savings (i.e. China, Japan and Korea on the U.S. current account seems to be exaggerated. Meanwhile, current account does not appear to be sensitive to changes in the exchange rate. This finding implies that the rectification of global imbalances is hardly possible to achieve by means of depreciating the U.S. dollar alone while leaving the structural factors unchanged. In order to achieve global rebalancing, the U.S. should increase its savings rate, reduce fiscal deficit, and tighten its money supply. While an increase in the domestic demand in the surplus countries such as China and Japan may be helpful in rectifying global imbalances, it appears to be insufficient per se.

  12. AMP-activated protein kinase plays an important evolutionary conserved role in the regulation of glucose metabolism in fish skeletal muscle cells.

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    Leonardo J Magnoni

    Full Text Available 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 that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively. We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase and mitochondrial biogenesis (PGC-1α and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish.

  13. Expression of apoplast-targeted plant defensin MtDef4.2 confers resistance to leaf rust pathogen Puccinia triticina but does not affect mycorrhizal symbiosis in transgenic wheat.

    Science.gov (United States)

    Kaur, Jagdeep; Fellers, John; Adholeya, Alok; Velivelli, Siva L S; El-Mounadi, Kaoutar; Nersesian, Natalya; Clemente, Thomas; Shah, Dilip

    2017-02-01

    Rust fungi of the order Pucciniales are destructive pathogens of wheat worldwide. Leaf rust caused by the obligate, biotrophic basidiomycete fungus Puccinia triticina (Pt) is an economically important disease capable of causing up to 50 % yield losses. Historically, resistant wheat cultivars have been used to control leaf rust, but genetic resistance is ephemeral and breaks down with the emergence of new virulent Pt races. There is a need to develop alternative measures for control of leaf rust in wheat. Development of transgenic wheat expressing an antifungal defensin offers a promising approach to complement the endogenous resistance genes within the wheat germplasm for durable resistance to Pt. To that end, two different wheat genotypes, Bobwhite and Xin Chun 9 were transformed with a chimeric gene encoding an apoplast-targeted antifungal plant defensin MtDEF4.2 from Medicago truncatula. Transgenic lines from four independent events were further characterized. Homozygous transgenic wheat lines expressing MtDEF4.2 displayed resistance to Pt race MCPSS relative to the non-transgenic controls in growth chamber bioassays. Histopathological analysis suggested the presence of both pre- and posthaustorial resistance to leaf rust in these transgenic lines. MtDEF4.2 did not, however, affect the root colonization of a beneficial arbuscular mycorrhizal fungus Rhizophagus irregularis. This study demonstrates that the expression of apoplast-targeted plant defensin MtDEF4.2 can provide substantial resistance to an economically important leaf rust disease in transgenic wheat without negatively impacting its symbiotic relationship with the beneficial mycorrhizal fungus.

  14. Universal and culture-specific factors in the recognition and performance of musical affect expressions.

    Science.gov (United States)

    Laukka, Petri; Eerola, Tuomas; Thingujam, Nutankumar S; Yamasaki, Teruo; Beller, Grégory

    2013-06-01

    We present a cross-cultural study on the performance and perception of affective expression in music. Professional bowed-string musicians from different musical traditions (Swedish folk music, Hindustani classical music, Japanese traditional music, and Western classical music) were instructed to perform short pieces of music to convey 11 emotions and related states to listeners. All musical stimuli were judged by Swedish, Indian, and Japanese participants in a balanced design, and a variety of acoustic and musical cues were extracted. Results first showed that the musicians' expressive intentions could be recognized with accuracy above chance both within and across musical cultures, but communication was, in general, more accurate for culturally familiar versus unfamiliar music, and for basic emotions versus nonbasic affective states. We further used a lens-model approach to describe the relations between the strategies that musicians use to convey various expressions and listeners' perceptions of the affective content of the music. Many acoustic and musical cues were similarly correlated with both the musicians' expressive intentions and the listeners' affective judgments across musical cultures, but the match between musicians' and listeners' uses of cues was better in within-cultural versus cross-cultural conditions. We conclude that affective expression in music may depend on a combination of universal and culture-specific factors.

  15. Altered Expression of the Malate-Permeable Anion Channel OsALMT4 Reduces the Growth of Rice Under Low Radiance

    OpenAIRE

    Jie Liu; Jie Liu; Muyun Xu; Gonzalo M. Estavillo; Emmanuel Delhaize; Rosemary G. White; Meixue Zhou; Peter R. Ryan

    2018-01-01

    We examined the function of OsALMT4 in rice (Oryza sativa L.) which is a member of the aluminum-activated malate transporter family. Previous studies showed that OsALMT4 localizes to the plasma membrane and that expression in transgenic rice lines results in a constitutive release of malate from the roots. Here, we show that OsALMT4 is expressed widely in roots, shoots, flowers, and grain but not guard cells. Expression was also affected by ionic and osmotic stress, light and to the hormones ...

  16. Who I am depends on how I feel: the role of affect in the expression of culture.

    Science.gov (United States)

    Ashton-James, Claire E; Maddux, William W; Galinsky, Adam D; Chartrand, Tanya L

    2009-03-01

    We present a novel role of affect in the expression of culture. Four experiments tested whether individuals' affective states moderate the expression of culturally normative cognitions and behaviors. We consistently found that value expressions, self-construals, and behaviors were less consistent with cultural norms when individuals were experiencing positive rather than negative affect. Positive affect allowed individuals to explore novel thoughts and behaviors that departed from cultural constraints, whereas negative affect bound people to cultural norms. As a result, when Westerners experienced positive rather than negative affect, they valued self-expression less, showed a greater preference for objects that reflected conformity, viewed the self in more interdependent terms, and sat closer to other people. East Asians showed the reverse pattern for each of these measures, valuing and expressing individuality and independence more when experiencing positive than when experiencing negative affect. The results suggest that affect serves an important functional purpose of attuning individuals more or less closely to their cultural heritage.

  17. Glucosamine-induced endoplasmic reticulum stress affects GLUT4 expression via activating transcription factor 6 in rat and human skeletal muscle cells

    DEFF Research Database (Denmark)

    Raciti, G A; Iadicicco, C; Ulianich, L

    2010-01-01

    Glucosamine, generated during hyperglycaemia, causes insulin resistance in different cells. Here we sought to evaluate the possible role of endoplasmic reticulum (ER) stress in the induction of insulin resistance by glucosamine in skeletal muscle cells.......Glucosamine, generated during hyperglycaemia, causes insulin resistance in different cells. Here we sought to evaluate the possible role of endoplasmic reticulum (ER) stress in the induction of insulin resistance by glucosamine in skeletal muscle cells....

  18. Calcium affecting protein expression in longan under simulated acid rain stress.

    Science.gov (United States)

    Pan, Tengfei; Li, Yongyu; Ma, Cuilan; Qiu, Dongliang

    2015-08-01

    Longan (Dimocarpus longana Lour. cv. Wulongling) of uniform one-aged seedlings grown in pots were selected to study specific proteins expressed in leaves under simulated acid rain (SiAR) stress and exogenous Ca(2+) regulation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results showed that there was a protein band specifically expressed under SiAR of pH 2.5 stress for 15 days with its molecular weight of about 23 kD. A 17 kD protein band specifically expressed after SiAR stress 5 days. Compared with pH 2.5, the pH 3.5 of SiAR made a less influence to protein expression. Two-dimensional electrophoresis (2-DE) results showed that six new specific proteins including C4 (20.2 kD pI 6.0), F (24 kD pI 6.35), B3 (22.3 kD pI 6.35), B4 (23.5 kD pI 6.5), C5 (21.8 kD pI 5.6), and C6 (20.2 kD pI 5.6) specifically expressed. C4 always expressed during SiAR stress. F expressed under the stress of pH 2.5 for 15 days and expressed in all pH SiAR stress for 20 days. The expression of proteins including B3, C5, and C6 was related to pH value and stress intensity of SiAR. The expression of B4 resulted from synergistic effects of SiAR and Ca. The expression of G1 (Mr 19.3 kD, pI 4.5), G2 (Mr 17.8 kD, pI 4.65), G3 (Mr 16.6 kD, pI 4.6), and G4 (Mr 14.7 kD, pI 4.4) enhanced under the treatment of 5 mM ethylene glycol tetraacetic acid (EGTA) and 2 mM chlorpromazine (CPZ). These proteins showed antagonistic effects and might be relative to the Ca-calmodulin (Ca-CaM) system of longan in response to SiAR stress.

  19. Effect of embryo density on in vitro development and gene expression in bovine in vitro-fertilized embryos cultured in a microwell system.

    Science.gov (United States)

    Sugimura, Satoshi; Akai, Tomonori; Hashiyada, Yutaka; Aikawa, Yoshio; Ohtake, Masaki; Matsuda, Hideo; Kobayashi, Shuji; Kobayashi, Eiji; Konishi, Kazuyuki; Imai, Kei

    2013-01-01

    To identify embryos individually during in vitro development, we previously developed the well-of-the-well (WOW) dish, which contains 25 microwells. Here we investigated the effect of embryo density (the number of embryos per volume of medium) on in vitro development and gene expression of bovine in vitro-fertilized embryos cultured in WOW dishes. Using both conventional droplet and WOW culture formats, 5, 15, and 25 bovine embryos were cultured in 125 μl medium for 168 h. The blastocysts at Day 7 were analyzed for number of cells and expression of ten genes (CDX2, IFN-tau, PLAC8, NANOG, OCT4, SOX2, AKR1B1, ATP5A1, GLUT1 and IGF2R). In droplet culture, the rates of formation of >4-cell cleavage embryos and blastocysts were significantly lower in embryos cultured at 5 embryos per droplet than in those cultured at 15 or 25 embryos per droplet, but not in WOW culture. In both droplet and WOW culture, developmental kinetics and blastocyst cell numbers did not differ among any groups. IFN-tau expression in embryos cultured at 25 embryos per droplet was significantly higher than in those cultured at 15 embryos per droplet and in artificial insemination (AI)-derived blastocysts. Moreover, IGF2R expression was significantly lower in the 25-embryo group than in the 5-embryo group and in AI-derived blastocysts. In WOW culture, these expressions were not affected by embryo density and were similar to those in AI-derived blastocysts. These results suggest that, as compared with conventional droplet culture, in vitro development and expression of IFN-tau and IGF2R in the microwell system may be insensitive to embryo density.

  20. Efeitos do exercício físico na expressão e atividade da AMPKα em ratos obesos induzidos por dieta rica em gordura Effects of physical exercise in the Ampkα expression and activity in high-fat diet induced obese rats

    Directory of Open Access Journals (Sweden)

    José Rodrigo Pauli

    2009-04-01

    Full Text Available INTRODUÇÃO: A ingestão de dieta hiperlipídica é um fator de risco singular no desenvolvimento de resistência à insulina e diabetes do tipo 2. OBJETIVO: O estudo investigou os efeitos do exercício físico na expressão e atividade da AMPKα em ratos obesos. MÉTODOS: Foram utilizados ratos Wistar, aleatoriamente divididos em quatro grupos, que receberam dieta padrão de manutenção (grupo controle ou dieta hiperlipídica (DHL (grupos sedentários e exercitados, por período de quatro meses. Dois diferentes protocolos de exercícios foram utilizados: exercício agudo ou crônico de natação. O teste de tolerância à insulina foi realizado para estimar a sensibilidade à insulina. Os níveis protéicos da AMPKα e do GLUT4 e também de p-AMPKα e pACC no músculo esquelético dos ratos foram determinados através da técnica de Western blot. RESULTADOS: O teste de tolerância à insulina revelou significativo prejuízo na ação da insulina após a alimentação com a DHL, indicando insulino-resistência quando comparado com grupo controle (p INTRODUCTION: High-fat diet is a special risk factor in the development of insulin resistance and type 2 diabetes. OBJECTIVE: To investigate the effects of physical exercise on the AMPK expression and activity in high-fat diet induced obese rats. METHODS: Wistar rats were randomly divided into four groups and received either a rat maintenance diet (control group or an isocaloric high-fat diet (HFD (sedentary groups and exercised groups for four months. Two different exercise protocols were utilized: acute or chronic swimming exercise. Insulin tolerance test was performed to estimate whole-body insulin sensitivity. AMPKα and GLUT4 as well as p-AMPKα and pACC of rats' skeletal muscle levels were determined using Western blot. RESULTS: Insulin tolerance test revealed a significantly impaired insulin action after HFDt feeding, indicating high-fat induced insulin resistance when compared to control

  1. Quantitative gene expression underlying 18f-fluorodeoxyglucose uptake in colon cancer

    DEFF Research Database (Denmark)

    Engelmann, Bodil E.; Binderup, Tina; Kjær, Andreas

    2015-01-01

    Background: Positron emission tomography (PET) with the glucose analogue 18F-fluorodeoxyglucose (FDG) is widely used in oncologic imaging. This study examines the molecular mechanism underlying the detection of colon cancer (CC) by FDG-PET. Methods: Pre-operative PET/CT scans and tissue samples....... Mean gene expression levels of GLUT1, HK2, ki67, HIF1α, VEGF and CaIX, but not HK1, were significantly higher in primary tumours than in surrounding normal colonic mucosa. Linear regressions pairing tumour SUVmax with gene expression levels showed significant correlations between SUVmax and HK2, ki67...

  2. Serotonin transporter gene-linked polymorphism affects detection of facial expressions.

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    Ai Koizumi

    Full Text Available Previous studies have demonstrated that the serotonin transporter gene-linked polymorphic region (5-HTTLPR affects the recognition of facial expressions and attention to them. However, the relationship between 5-HTTLPR and the perceptual detection of others' facial expressions, the process which takes place prior to emotional labeling (i.e., recognition, is not clear. To examine whether the perceptual detection of emotional facial expressions is influenced by the allelic variation (short/long of 5-HTTLPR, happy and sad facial expressions were presented at weak and mid intensities (25% and 50%. Ninety-eight participants, genotyped for 5-HTTLPR, judged whether emotion in images of faces was present. Participants with short alleles showed higher sensitivity (d' to happy than to sad expressions, while participants with long allele(s showed no such positivity advantage. This effect of 5-HTTLPR was found at different facial expression intensities among males and females. The results suggest that at the perceptual stage, a short allele enhances the processing of positive facial expressions rather than that of negative facial expressions.

  3. Immunohistochemical study of p16 INK4A and survivin expressions in cervical squamous neoplasm

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    Tan Geok

    2010-01-01

    Full Text Available Introduction:Cervical cancer is the second most common cancer affecting Malaysian women. Despite the implementation of pap smear screening, many women are still diagnosed only in the advanced stage of cervical cancer. This could partly be due to failure of detection of its precursor lesions; hence the need to search for novel biomarkers to assist in the screening and diagnosis of cervical neoplasia. This study aims to determine the expression of p16INK4A and survivin as possible predictive biomarkers in cervical squamous neoplasm. Material and Methods: This is a retrospective study on 201 cases of cervical neoplasm comprising of 129 cervical intraepithelial neoplasia (CIN and 72 squamous cell carcinoma (SCC. All samples were evaluated by two independent observers using p16INK4A and survivin monoclonal antibodies. The p16 INK4A expression was graded as negative, focal and diffuse positivity. The intensity for survivin expression was graded as weak, moderate and intense. Results: It is seen that p16 INK4A expression in CIN 1, CIN 2 and CIN 3 were 25.4%, 42.9% and 95.9% respectively. Majority of SCC (98.6% showed p16 INK4A expression. Survivin expressions in CIN 1, CIN 2, CIN 3 and SCC were 56.7%, 33.4%, 87.5% and 98.6%. There was a linear relationship between increasing grade of CIN and p16 INK4A expressions. Conclusion: Our study showed that p16 INK4A expressions correlate well with the increasing grade of CIN. Although survivin does not correlate well to the increasing grade of CIN, it could be useful in differentiating CIN 3 from SCC.

  4. Septin 7 reduces nonmuscle myosin IIA activity in the SNAP23 complex and hinders GLUT4 storage vesicle docking and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Wasik, Anita A.; Dumont, Vincent [Department of Pathology, University of Helsinki, 00014 Helsinki (Finland); Tienari, Jukka [Department of Pathology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, 05850 Hyvinkää (Finland); Nyman, Tuula A. [Institute of Biotechnology, University of Helsinki, 00014 Helsinki (Finland); Fogarty, Christopher L.; Forsblom, Carol; Lehto, Markku [Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki (Finland); Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, 000290 Helsinki (Finland); Diabetes& Obesity Research Program, Research Program´s Unit, 00014 University of Helsinki (Finland); Lehtonen, Eero [Department of Pathology, University of Helsinki, 00014 Helsinki (Finland); Laboratory Animal Centre, University of Helsinki, 00014 Helsinki (Finland); Groop, Per-Henrik [Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki (Finland); Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, 000290 Helsinki (Finland); Diabetes& Obesity Research Program, Research Program´s Unit, 00014 University of Helsinki (Finland); Baker IDI Heart & Diabetes Institute, 3004 Melbourne (Australia); Lehtonen, Sanna, E-mail: sanna.h.lehtonen@helsinki.fi [Department of Pathology, University of Helsinki, 00014 Helsinki (Finland)

    2017-01-15

    Glomerular epithelial cells, podocytes, are insulin responsive and can develop insulin resistance. Here, we demonstrate that the small GTPase septin 7 forms a complex with nonmuscle myosin heavy chain IIA (NMHC-IIA; encoded by MYH9), a component of the nonmuscle myosin IIA (NM-IIA) hexameric complex. We observed that knockdown of NMHC-IIA decreases insulin-stimulated glucose uptake into podocytes. Both septin 7 and NM-IIA associate with SNAP23, a SNARE protein involved in GLUT4 storage vesicle (GSV) docking and fusion with the plasma membrane. We observed that insulin decreases the level of septin 7 and increases the activity of NM-IIA in the SNAP23 complex, as visualized by increased phosphorylation of myosin regulatory light chain. Also knockdown of septin 7 increases the activity of NM-IIA in the complex. The activity of NM-IIA is increased in diabetic rat glomeruli and cultured human podocytes exposed to macroalbuminuric sera from patients with type 1 diabetes. Collectively, the data suggest that the activity of NM-IIA in the SNAP23 complex plays a key role in insulin-stimulated glucose uptake into podocytes. Furthermore, we observed that septin 7 reduces the activity of NM-IIA in the SNAP23 complex and thereby hinders GSV docking and fusion with the plasma membrane. - Highlights: • Septin 7, nonmuscle myosin heavy chain IIA (NMHC-IIA) and SNAP23 form a complex. • Knockdown of septin 7 increases NM-IIA activity in the SNAP23 complex. • Insulin decreases septin 7 level and increases NM-IIA activity in the SNAP23 complex. • Septin 7 hinders GSV docking/fusion by reducing NM-IIA activity in the SNAP23 complex.

  5. Septin 7 reduces nonmuscle myosin IIA activity in the SNAP23 complex and hinders GLUT4 storage vesicle docking and fusion

    International Nuclear Information System (INIS)

    Wasik, Anita A.; Dumont, Vincent; Tienari, Jukka; Nyman, Tuula A.; Fogarty, Christopher L.; Forsblom, Carol; Lehto, Markku; Lehtonen, Eero; Groop, Per-Henrik; Lehtonen, Sanna

    2017-01-01

    Glomerular epithelial cells, podocytes, are insulin responsive and can develop insulin resistance. Here, we demonstrate that the small GTPase septin 7 forms a complex with nonmuscle myosin heavy chain IIA (NMHC-IIA; encoded by MYH9), a component of the nonmuscle myosin IIA (NM-IIA) hexameric complex. We observed that knockdown of NMHC-IIA decreases insulin-stimulated glucose uptake into podocytes. Both septin 7 and NM-IIA associate with SNAP23, a SNARE protein involved in GLUT4 storage vesicle (GSV) docking and fusion with the plasma membrane. We observed that insulin decreases the level of septin 7 and increases the activity of NM-IIA in the SNAP23 complex, as visualized by increased phosphorylation of myosin regulatory light chain. Also knockdown of septin 7 increases the activity of NM-IIA in the complex. The activity of NM-IIA is increased in diabetic rat glomeruli and cultured human podocytes exposed to macroalbuminuric sera from patients with type 1 diabetes. Collectively, the data suggest that the activity of NM-IIA in the SNAP23 complex plays a key role in insulin-stimulated glucose uptake into podocytes. Furthermore, we observed that septin 7 reduces the activity of NM-IIA in the SNAP23 complex and thereby hinders GSV docking and fusion with the plasma membrane. - Highlights: • Septin 7, nonmuscle myosin heavy chain IIA (NMHC-IIA) and SNAP23 form a complex. • Knockdown of septin 7 increases NM-IIA activity in the SNAP23 complex. • Insulin decreases septin 7 level and increases NM-IIA activity in the SNAP23 complex. • Septin 7 hinders GSV docking/fusion by reducing NM-IIA activity in the SNAP23 complex.

  6. Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

    International Nuclear Information System (INIS)

    Ploug, T.; Stallknecht, B.M.; Pedersen, O.; Kahn, B.B.; Ohkuwa, T.; Vinten, J.; Galbo, H.

    1990-01-01

    The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters

  7. The prognostic value of endogenous hypoxia-related markers for head and neck squamous cell carcinomas treated with ARCON

    International Nuclear Information System (INIS)

    Jonathan, Ruth A.; Wijffels, Karien I.E.M.; Peeters, Wenny; Wilde, Peter C.M. de; Marres, Henri A.M.; Merkx, Matthias A.W.; Oosterwijk, Egbert; Kogel, Albert van der J.; Kaanders, Johannes H.A.M.

    2006-01-01

    Background and purpose: Hypoxic radioresistance is an important cause for treatment failure in a number of tumor types including head and neck cancers. Recent studies suggest that outcome can be improved by oxygenation modifying treatments such as ARCON. A robust endogenous marker of hypoxia might be a valuable aid to select patients for such treatments. The aim of this investigation was to study associations between the putative endogenous hypoxia markers CA-IX, Glut-1 and Glut-3 and clinical tumor and patient characteristics and to evaluate the prognostic value of these markers. Patients and methods: Tumor biopsies from 58 patients treated with ARCON in a phase II trial were included. Tumor sections were immunohistochemically stained for CA-IX, Glut-1 and Glut-3. Sections were scored for relative tumor area stained by the markers (CA-IX and Glut-3) and for intensity of staining (Glut-1 and Glut-3). Further, sections were stained for CD34, an endothelial marker to assess microvascular density. Results: Staining of CA-IX and Glut-3 was observed at some distance from vessels and adjacent to necrosis. Glut-1 staining was generally very diffuse. The distribution of clinical characteristics was equal between tumors with high and low marker expression. Significant differences were found for locoregional control (P=0.04) and for freedom of distant metastases (P=0.02) in favour of patients with high CA-IX positivity (>25% of tumor area). High Glut-3 expression was associated with a better locoregional control (P=0.04). Higher Glut-1 intensity was associated with an increased rate of distant metastases (P=0.0005) and a worse overall survival (P=0.001). Conclusions: The inconsistent associations with outcome of CA-IX and the glucose transporters indicate that different factors play a role in up-regulation of these markers. Compared to studies with conventional treatment, the correlation between CA-IX expression and Glut-3 expression and outcome was reversed after treatment

  8. Tumor SHB gene expression affects disease characteristics in human acute myeloid leukemia.

    Science.gov (United States)

    Jamalpour, Maria; Li, Xiujuan; Cavelier, Lucia; Gustafsson, Karin; Mostoslavsky, Gustavo; Höglund, Martin; Welsh, Michael

    2017-10-01

    The mouse Shb gene coding for the Src Homology 2-domain containing adapter protein B has recently been placed in context of BCRABL1-induced myeloid leukemia in mice and the current study was performed in order to relate SHB to human acute myeloid leukemia (AML). Publicly available AML databases were mined for SHB gene expression and patient survival. SHB gene expression was determined in the Uppsala cohort of AML patients by qPCR. Cell proliferation was determined after SHB gene knockdown in leukemic cell lines. Despite a low frequency of SHB gene mutations, many tumors overexpressed SHB mRNA compared with normal myeloid blood cells. AML patients with tumors expressing low SHB mRNA displayed longer survival times. A subgroup of AML exhibiting a favorable prognosis, acute promyelocytic leukemia (APL) with a PMLRARA translocation, expressed less SHB mRNA than AML tumors in general. When examining genes co-expressed with SHB in AML tumors, four other genes ( PAX5, HDAC7, BCORL1, TET1) related to leukemia were identified. A network consisting of these genes plus SHB was identified that relates to certain phenotypic characteristics, such as immune cell, vascular and apoptotic features. SHB knockdown in the APL PMLRARA cell line NB4 and the monocyte/macrophage cell line MM6 adversely affected proliferation, linking SHB gene expression to tumor cell expansion and consequently to patient survival. It is concluded that tumor SHB gene expression relates to AML survival and its subgroup APL. Moreover, this gene is included in a network of genes that plays a role for an AML phenotype exhibiting certain immune cell, vascular and apoptotic characteristics.

  9. Additional Prognostic Value of SUVmax Measured by F-18 FDG PET/CT over Biological Marker Expressions in Surgically Resected Cervical Cancer Patients.

    Science.gov (United States)

    Yun, Man Soo; Kim, Seong-Jang; Pak, Kyoungjune; Lee, Chang Hun

    2015-01-01

    We compared the prognostic ability of the maximum standardized uptake value (SUVmax) and various biological marker expressions to predict recurrence in patients with surgically resected cervical cancer. A retrospective review identified 60 patients with cervical cancer who received [18F]fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) at the time of the diagnosis of cancer. The SUVmax, expressions of carbonic anhydrase-IX (CA-IX), glucose transporter 1 (GLUT-1), and vascular endothelial growth factor (VEGF), and known prognostic factors were investigated. The median follow-up time was 22.2 months (range 3.4-43.1 months). Using univariate analyses, the stage (stage II, p = 0.0066), SUVmax (> 6, p = 0.027), parametrial involvement (p value than biological marker expression in patients with surgically resected cervical cancer. © 2015 S. Karger GmbH, Freiburg.

  10. Facial Expression of Affect in Children with Cornelia de Lange Syndrome

    Science.gov (United States)

    Collis, L.; Moss, J.; Jutley, J.; Cornish, K.; Oliver, C.

    2008-01-01

    Background: Individuals with Cornelia de Lange syndrome (CdLS) have been reported to show comparatively high levels of flat and negative affect but there have been no empirical evaluations. In this study, we use an objective measure of facial expression to compare affect in CdLS with that seen in Cri du Chat syndrome (CDC) and a group of…

  11. From specificity to sensitivity: affective states modulate visual working memory for emotional expressive faces.

    Science.gov (United States)

    Maran, Thomas; Sachse, Pierre; Furtner, Marco

    2015-01-01

    Previous findings suggest that visual working memory (VWM) preferentially remembers angry looking faces. However, the meaning of facial actions is construed in relation to context. To date, there are no studies investigating the role of perceiver-based context when processing emotional cues in VWM. To explore the influence of affective context on VWM for faces, we conducted two experiments using both a VWM task for emotionally expressive faces and a mood induction procedure. Affective context was manipulated by unpleasant (Experiment 1) and pleasant (Experiment 2) IAPS pictures in order to induce an affect high in motivational intensity (defensive or appetitive, respectively) compared to a low arousal control condition. Results indicated specifically increased sensitivity of VWM for angry looking faces in the neutral condition. Enhanced VWM for angry faces was prevented by inducing affects of high motivational intensity. In both experiments, affective states led to a switch from specific enhancement of angry expressions in VWM to an equally sensitive representation of all emotional expressions. Our findings demonstrate that emotional expressions are of different behavioral relevance for the receiver depending on the affective context, supporting a functional organization of VWM along with flexible resource allocation. In VWM, stimulus processing adjusts to situational requirements and transitions from a specifically prioritizing default mode in predictable environments to a sensitive, hypervigilant mode in exposure to emotional events.

  12. Prognostic significance of XRCC4 expression in hepatocellular carcinoma

    Science.gov (United States)

    Huang, Xiao-Ying; Yao, Jin-Guang; Wang, Chao; Wei, Zhong-Hong; Ma, Yun; Wu, Xue-Min; Luo, Chun-Ying; Xia, Qiang; Long, Xi-Dai

    2017-01-01

    Background Our previous investigations have shown that the variants of X-ray repair complementing 4 (XRCC4) may be involved in hepatocellular carcinoma (hepatocarcinoma) tumorigenesis. This study aimed to investigate the possible prognostic significance of XRCC4 expression for hepatocarcinoma patients and possible value for the selection of transarterial chemoembolization (TACE) treatment. Materials and Methods We conducted a hospital-based retrospective analysis (including 421 hepatocarcinoma cases) to analyze the effects of XRCC4 on hepatocarcinoma prognosis and TACE. The levels of XRCC4 expression were tested using immunohistochemistry. The sensitivity of cancer cells to anti-cancer drug doxorubicin was evaluated using the half-maximal inhibitory concentration (IC50). Results XRCC4 expression was significantly correlated with pathological features including tumor stage, liver cirrhosis, and micro-vessel density. XRCC4 expression was an independent prognostic factor of hepatocarcinoma, and TACE treatments had no effects on prognosis of hepatocarcinoma patients with high XRCC4 expression. More intriguingly, TACE improved the prognosis of hepatocarcinoma patients with low XRCC4 expression. Functionally, XRCC4 overexpression increased while XRCC4 knockdown reduced the IC50 of cancer cells to doxorubicin. Conclusions These results suggest that XRCC4 may be an independent prognostic factor for hepatocarcinoma patients, and that decreasing XRCC4 expression may be beneficial for post-operative adjuvant TACE treatment in hepatocarcinoma. PMID:29152133

  13. Myocardin-related transcription factor regulates Nox4 protein expression

    DEFF Research Database (Denmark)

    Rozycki, Matthew; Bialik, Janne Folke; Speight, Pam

    2016-01-01

    translocation of MRTF. Because the Nox4 promoter harbors a serum response factor/MRTF cis-element (CC(A/T)6GG box), we asked if MRTF (and thus cytoskeleton organization) could regulate Nox4 expression. We show that Nox4 protein is robustly induced in kidney tubular cells exclusively by combined application...... TGFβ/contact disruption-provoked Nox4 protein and mRNA expression, Nox4 promoter activation, and reactive oxygen species production. Mutation of the CC(A/T)6GG box eliminates the synergistic activation of the Nox4 promoter. Jasplakinolide-induced actin polymerization synergizes with TGFβ to facilitate...... MRTF-dependent Nox4 mRNA expression/promoter activation. Moreover, MRTF inhibition prevents Nox4 expression during TGFβ-induced fibroblast-myofibroblast transition as well. Although necessary, MRTF is insufficient; Nox4 expression also requires TGFβ-activated Smad3 and TAZ/YAP, two contact...

  14. The E4 protein; structure, function and patterns of expression

    Energy Technology Data Exchange (ETDEWEB)

    Doorbar, John, E-mail: jdoorba@nimr.mrc.ac.uk

    2013-10-15

    The papillomavirus E4 open reading frame (ORF) is contained within the E2 ORF, with the primary E4 gene-product (E1{sup ∧}E4) being translated from a spliced mRNA that includes the E1 initiation codon and adjacent sequences. E4 is located centrally within the E2 gene, in a region that encodes the E2 protein′s flexible hinge domain. Although a number of minor E4 transcripts have been reported, it is the product of the abundant E1{sup ∧}E4 mRNA that has been most extensively analysed. During the papillomavirus life cycle, the E1{sup ∧}E4 gene products generally become detectable at the onset of vegetative viral genome amplification as the late stages of infection begin. E4 contributes to genome amplification success and virus synthesis, with its high level of expression suggesting additional roles in virus release and/or transmission. In general, E4 is easily visualised in biopsy material by immunostaining, and can be detected in lesions caused by diverse papillomavirus types, including those of dogs, rabbits and cattle as well as humans. The E4 protein can serve as a biomarker of active virus infection, and in the case of high-risk human types also disease severity. In some cutaneous lesions, E4 can be expressed at higher levels than the virion coat proteins, and can account for as much as 30% of total lesional protein content. The E4 proteins of the Beta, Gamma and Mu HPV types assemble into distinctive cytoplasmic, and sometimes nuclear, inclusion granules. In general, the E4 proteins are expressed before L2 and L1, with their structure and function being modified, first by kinases as the infected cell progresses through the S and G2 cell cycle phases, but also by proteases as the cell exits the cell cycle and undergoes true terminal differentiation. The kinases that regulate E4 also affect other viral proteins simultaneously, and include protein kinase A, Cyclin-dependent kinase, members of the MAP Kinase family and protein kinase C. For HPV16 E1{sup

  15. TLR-4 polymorphisms and leukocyte TLR-4 expression in febrile UTI and renal scarring.

    Science.gov (United States)

    Bayram, Meral Torun; Soylu, Alper; Ateş, Halil; Kızıldağ, Sefa; Kavukçu, Salih

    2013-09-01

    In this study, we aimed to determine the relation of TLR-4 Asp299Gly and Thr399Ile polymorphisms and monocyte/neutrophil TLR-4 expression to febrile urinary tract infection (UTI) and renal scar development in children. The study was performed in children with a history of febrile UTI. Patients with and without renal scarring were classified as group 1 and group 2, respectively, while the control cases in our previous study were used as the control group (group 3). All three groups were compared for the rate of TLR-4 Asp299Gly and Thr399Ile polymorphisms, and for basal and lipopolysaccharide-stimulated monocyte/neutrophil TLR-4 expression levels. There were 168 patients (86 in group 1, 82 in group 2) and 120 control cases. Monocyte/neutrophil TLR-4 expression levels were similar in groups 1 and 2. However, both groups had lower TLR-4 expression than group 3. The rate of TLR-4 Asp299Gly polymorphism was not different in all groups. TLR-4 Thr399Ile polymorphism was higher in groups 1 and 2 than in group 3 (14.0, 12.2, and 2.0 %, respectively), while group 1 and group 2 were not different. Furthermore, monocyte TLR-4 expression level was lower in those having TLR-4 Thr399Ile polymorphism than in those without this polymorphism. Patients with febrile UTI had more frequent TLR-4 Thr399Ile polymorphism and lower monocyte/neutrophil TLR-4 expression. These findings indicate that children carrying TLR-4 Thr399Ile polymorphism and/or having low level of monocyte/neutrophil TLR-4 expression have a tendency to develop febrile UTI. However, we could not show the association of TLR-4 polymorphisms and of TLR-4 expression level to renal scarring.

  16. 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.

  17. Apolipoprotein E-epsilon 4 frequency in affective disorder

    DEFF Research Database (Denmark)

    Kessing, L V; Jørgensen, O S

    1999-01-01

    -Bråne-Steen Dementia Rating Scale, and the Global Deterioration Scale. RESULTS: The frequency of APOE-epsilon 4 allele was approximately the same in unipolar patients (.189) and in bipolar patients (.167). Although patients showed more cognitive impairment than controls, no significant overall difference was found...... was found with gender, age at onset, the number of affective episodes, the presence of psychotic features, or the prevalence of familial affective disorder. CONCLUSIONS: It seems that cognitive impairment in affective disorder can be attributed to pathways other than the APOE genotype.......BACKGROUND: The epsilon 4 allele of apolipoprotein E (APOE) as well as affective disorder have been found to be associated with Alzheimer's disease, but it is unclear whether cognitive impairment in affective disorder or subtypes of affective disorder is mediated by the epsilon 4 allele of APOE...

  18. COUP-TFI mitotically regulates production and migration of dentate granule cells and modulates hippocampal Cxcr4 expression.

    Science.gov (United States)

    Parisot, Joséphine; Flore, Gemma; Bertacchi, Michele; Studer, Michèle

    2017-06-01

    Development of the dentate gyrus (DG), the primary gateway for hippocampal inputs, spans embryonic and postnatal stages, and involves complex morphogenetic events. We have previously identified the nuclear receptor COUP-TFI as a novel transcriptional regulator in the postnatal organization and function of the hippocampus. Here, we dissect its role in DG morphogenesis by inactivating it in either granule cell progenitors or granule neurons. Loss of COUP-TFI function in progenitors leads to decreased granule cell proliferative activity, precocious differentiation and increased apoptosis, resulting in a severe DG growth defect in adult mice. COUP-TFI-deficient cells express high levels of the chemokine receptor Cxcr4 and migrate abnormally, forming heterotopic clusters of differentiated granule cells along their paths. Conversely, high COUP-TFI expression levels downregulate Cxcr4 expression, whereas increased Cxcr4 expression in wild-type hippocampal cells affects cell migration. Finally, loss of COUP-TFI in postmitotic cells leads to only minor and transient abnormalities, and to normal Cxcr4 expression. Together, our results indicate that COUP-TFI is required predominantly in DG progenitors for modulating expression of the Cxcr4 receptor during granule cell neurogenesis and migration. © 2017. Published by The Company of Biologists Ltd.

  19. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    International Nuclear Information System (INIS)

    Epstein, L.M.; Forney, J.D.

    1984-01-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei

  20. Animal Model of Gestational Diabetes Mellitus with Pathophysiological Resemblance to the Human Condition Induced by Multiple Factors (Nutritional, Pharmacological, and Stress in Rats

    Directory of Open Access Journals (Sweden)

    Siti Hajar Abdul Aziz

    2016-01-01

    Full Text Available This study attempts to develop an experimental gestational diabetes mellitus (GDM animal model in female Sprague-Dawley rats. Rats were fed with high fat sucrose diet, impregnated, and induced with Streptozotocin and Nicotinamide on gestational day 0 (D0. Sleeping patterns of the rats were also manipulated to induce stress, a lifestyle factor that contributes to GDM. Rats were tested for glycemic parameters (glucose, C-peptide, and insulin, lipid profiles (total cholesterol, triglycerides, HDL, and LDL, genes affecting insulin signaling (IRS-2, AKT-1, and PCK-1, glucose transporters (GLUT-2 and GLUT-4, proinflammatory cytokines (IL-6, TNF-α, and antioxidants (SOD, CAT, and GPX on D6 and D21. GDM rats showed possible insulin resistance as evidenced by high expression of proinflammatory cytokines, PCK-1 and CRP. Furthermore, low levels of IRS-2 and AKT-1 genes and downregulation of GLUT-4 from the initial to final phases indicate possible defect of insulin signaling. GDM rats also showed an impairment of antioxidant status and a hyperlipidemic state. Additionally, GDM rats exhibited significantly higher body weight and blood glucose and lower plasma insulin level and C-peptide than control. Based on the findings outlined, the current GDM animal model closely replicates the disease state in human and can serve as a reference for future investigations.

  1. Socializing infants towards a cultural understanding of expressing negative affect

    DEFF Research Database (Denmark)

    Demuth, Carolin

    2013-01-01

    This article addresses the socialization of emotion expression in infancy. It argues that in order to adequately understand emotion development we need to consider the appraisal of emotion expression through caregivers in mundane, everyday interactions. Drawing on sociocultural and Bakhtinian...... theorizing, it claims that caregivers’ appraisals of infants’ emotion expression are dialogically intertwined with broader speech genres or “communicative genres” of a community and the emotional-volitional tone and normative orientations embedded in them. It aims to investigate how communicative genres......’ expression of negative affect. We found distinct patterns of coconstructing the interaction that point to different normative ori- entations and communicative genres that can be considered to be specific to the two sociocultural contexts. These communicative genres were found to be in line with broader...

  2. Immunohistochemical expression profiles of mucin antigens in salivary gland mucoepidermoid carcinoma: MUC4- and MUC6-negative expression predicts a shortened survival in the early postoperative phase.

    Science.gov (United States)

    Honjo, Kie; Hiraki, Tsubasa; Higashi, Michiyo; Noguchi, Hirotsugu; Nomoto, Mitsuharu; Yoshimura, Takuya; Batra, Surinder K; Yonezawa, Suguru; Semba, Ichiro; Nakamura, Norifumi; Tanimoto, Akihide; Yamada, Sohsuke

    2018-02-01

    In mucoepidermoid carcinoma (MEC), the most common salivary gland carcinoma, there is a lack of novel prognostic markers, but post-operative early recurrence strongly affects the clinical course and a poor outcome. It is critical to predict which MEC patients are prone to develop recurrence/metastases. Mucins play pivotal roles in influencing cancer biology, thus affecting cell differentiation, adhesion, carcinoma invasion, aggressiveness and/or metastatic potential. Our aim is to elucidate the significance of expression profiles for mucins, particularly MUC4 and MUC6, and their correlations with various clinicopathological features and recurrence in salivary gland MECs. We performed immunohistochemical analyses on patients with surgically resected primary MEC using antibodies against mucin core proteins MUC4/8G7 and MUC6/CLH5 in 73 paraffin-embedded samples. Recurrence was noted in 15 of 73 (20.5%) patients. MUC4 or MUC6 expression was considered to be negative when <30% or 0% of the MEC cells showed positive staining, respectively. MUC4- and/or MUC6-negative expression respectively and variably showed a significant relationship to pathological tumor high-grade, the presence of lymphovascular invasion, lymph node metastasis and/or tumor-related death. In addition, MUC4 showed significantly negative co-expression with MUC6. Kaplan-Meier analyses revealed that not only single MUC4/6-negative expression but also the combination of both predicted significantly shorter disease-free and disease-specific survivals in MECs, especially within the first two years postoperatively. Therefore, each mucin plays a pivotal role in the pathogenesis of MEC progression. The detection of MUC4 and/or MUC6 might be a powerful parameter in the clinical management of MECs in the early postsurgical phase.

  3. Facial Expression at Retrieval Affects Recognition of Facial Identity

    Directory of Open Access Journals (Sweden)

    Wenfeng eChen

    2015-06-01

    Full Text Available It is well known that memory can be modulated by emotional stimuli at the time of encoding and consolidation. For example, happy faces create better identity recognition than faces with certain other expressions. However, the influence of facial expression at the time of retrieval remains unknown in the literature. To separate the potential influence of expression at retrieval from its effects at earlier stages, we had participants learn neutral faces but manipulated facial expression at the time of memory retrieval in a standard old/new recognition task. The results showed a clear effect of facial expression, where happy test faces were identified more successfully than angry test faces. This effect is unlikely due to greater image similarity between the neutral learning face and the happy test face, because image analysis showed that the happy test faces are in fact less similar to the neutral learning faces relative to the angry test faces. In the second experiment, we investigated whether this emotional effect is influenced by the expression at the time of learning. We employed angry or happy faces as learning stimuli, and angry, happy, and neutral faces as test stimuli. The results showed that the emotional effect at retrieval is robust across different encoding conditions with happy or angry expressions. These findings indicate that emotional expressions affect the retrieval process in identity recognition, and identity recognition does not rely on emotional association between learning and test faces.

  4. From Specificity to Sensitivity: Affective states modulate visual working memory for emotional expressive faces

    Directory of Open Access Journals (Sweden)

    Thomas eMaran

    2015-08-01

    Full Text Available Previous findings suggest that visual working memory preferentially remembers angry looking faces. However, the meaning of facial actions is construed in relation to context. To date, there are no studies investigating the role of perceiver-based context when processing emotional cues in visual working memory. To explore the influence of affective context on visual working memory for faces, we conducted two experiments using both a visual working memory task for emotionally expressive faces and a mood induction procedure. Affective context was manipulated by unpleasant (Experiment 1 and pleasant (Experiment 2 IAPS pictures in order to induce an affect high in motivational intensity (defensive or appetitive, respectively compared to a low arousal control condition. Results indicated specifically increased sensitivity of visual working memory for angry looking faces in the neutral condition. Enhanced visual working memory for angry faces was prevented by inducing affects of high motivational intensity. In both experiments, affective states led to a switch from specific enhancement of angry expressions in visual working memory to an equally sensitive representation of all emotional expressions. Our findings demonstrate that emotional expressions are of different behavioral relevance for the receiver depending on the affective context, supporting a functional organization of visual working memory along with flexible resource allocation. In visual working memory, stimulus processing adjusts to situational requirements and transitions from a specifically prioritizing default mode in predictable environments to a sensitive, hypervigilant mode in exposure to emotional events.

  5. Affective priming using facial expressions modulates liking for abstract art.

    Science.gov (United States)

    Flexas, Albert; Rosselló, Jaume; Christensen, Julia F; Nadal, Marcos; Olivera La Rosa, Antonio; Munar, Enric

    2013-01-01

    We examined the influence of affective priming on the appreciation of abstract artworks using an evaluative priming task. Facial primes (showing happiness, disgust or no emotion) were presented under brief (Stimulus Onset Asynchrony, SOA = 20 ms) and extended (SOA = 300 ms) conditions. Differences in aesthetic liking for abstract paintings depending on the emotion expressed in the preceding primes provided a measure of the priming effect. The results showed that, for the extended SOA, artworks were liked more when preceded by happiness primes and less when preceded by disgust primes. Facial expressions of happiness, though not of disgust, exerted similar effects in the brief SOA condition. Subjective measures and a forced-choice task revealed no evidence of prime awareness in the suboptimal condition. Our results are congruent with findings showing that the affective transfer elicited by priming biases evaluative judgments, extending previous research to the domain of aesthetic appreciation.

  6. Affective priming using facial expressions modulates liking for abstract art.

    Directory of Open Access Journals (Sweden)

    Albert Flexas

    Full Text Available We examined the influence of affective priming on the appreciation of abstract artworks using an evaluative priming task. Facial primes (showing happiness, disgust or no emotion were presented under brief (Stimulus Onset Asynchrony, SOA = 20 ms and extended (SOA = 300 ms conditions. Differences in aesthetic liking for abstract paintings depending on the emotion expressed in the preceding primes provided a measure of the priming effect. The results showed that, for the extended SOA, artworks were liked more when preceded by happiness primes and less when preceded by disgust primes. Facial expressions of happiness, though not of disgust, exerted similar effects in the brief SOA condition. Subjective measures and a forced-choice task revealed no evidence of prime awareness in the suboptimal condition. Our results are congruent with findings showing that the affective transfer elicited by priming biases evaluative judgments, extending previous research to the domain of aesthetic appreciation.

  7. Increased TLR4 expression in murine placentas after oral infection with periodontal pathogens

    Science.gov (United States)

    Arce, R.M.; Barros, S.P.; Wacker, B.; Peters, B.; Moss, K.; Offenbacher, S.

    2009-01-01

    Maternal periodontitis has emerged as a putative risk factor for preterm births in humans. The periodontitis-associated dental biofilm is thought to serve as an important source of oral bacteria and related virulence factors that hematogenously disseminate and affect the fetoplacental unit; however the underlying biological mechanisms are yet to be fully elucidated. This study hypothesized that an oral infection with the human periodontal pathogens Campylobacter rectus and Porphyromonas gingivalis is able to induce fetal growth restriction, placental inflammation and enhance Toll-like receptors type 4 (TLR4) expression in a murine pregnancy model. Female Balb/C mice (n=40) were orally infected with C. rectus and/or P. gingivalis over a 16-week period and mated once per week. Pregnant mice were sacrificed at embryonic day (E) 16.5 and placentas were collected and analyzed for TLR4 mRNA levels and qualitative protein expression by real time PCR and immunofluorescence. TLR4 mRNA expression was found to be increased in C. rectus-infected group (1.98±0.886 fold difference, Pperiodontal pathogens. The TLR4 pathway has been implicated in the pathogenesis of preterm births; therefore the abnormal regulation of placental TLR4 may give new insights into how maternal periodontitis and periodontal pathogens might be linked to placental inflammation and preterm birth pathogenesis. PMID:19101032

  8. The ontogeny of nutrient transporter and digestive enzyme gene expression in domestic pigeon (Columba livia) intestine and yolk sac membrane during pre- and posthatch development.

    Science.gov (United States)

    Dong, X Y; Wang, Y M; Yuan, C; Zou, X T

    2012-08-01

    To better understand the digestive capacity in domestic pigeons (Columba livia), this study was conducted to evaluate nutrient transporters and digestive enzymes gene expression in small intestine and yolk sac membrane (YSM) during pre- and posthatch development. We investigated the oligopeptide transporter Pept1, sodium glucose transporter SGLT1, glucose transporter GLUT2, aminopeptidase-N (APN), and sucrase-isomaltase (SI). Intestine was collected at embryo d 12, 14, and 16, day of hatch, and d 1, 3, 5, 8, and 14 posthatch. The YSM was collected at embryo d 12, 14, 16, and day of hatch. The cDNA fragments for Pept1, SGLT1, GLUT2, APN, and SI were isolated and cloned using reverse-transcription PCR. The sequences data showed that these genes were highly identical to the gene of chicken. The mRNA expression of each gene was assayed using real-time PCR. Expression of intestinal nutrient transporters increased linearly (Ppigeons and establish a foundation for future research on the nutrients requirements for young pigeons.

  9. Expression of C4.4A in an in Vitro Human Tissue-Engineered Skin Model

    DEFF Research Database (Denmark)

    Jacobsen, Benedikte; Larouche, Danielle; Rochette-Drouin, Olivier

    2017-01-01

    , the biological function of C4.4A remains unknown. To enable further studies, we evaluated the expression of C4.4A in monolayer cultures of normal human keratinocytes and in tissue-engineered skin substitutes (TESs) produced by the self-assembly approach, which allow the formation of a fully differentiated...... epidermis tissue. Results showed that, in monolayer, C4.4A was highly expressed in the centre of keratinocyte colonies at cell-cell contacts areas, while some cells located at the periphery presented little C4.4A expression. In TES, emergence of C4.4A expression coincided with the formation of the stratum...

  10. Factors influencing [F-18]2-fluoro-2-deoxy-D-glucose (F-18 FDG) uptake in melanoma cells. The role of proliferation rate, viability, glucose transporter expression and hexokinase activity

    International Nuclear Information System (INIS)

    Yamada, Kiyoshi; Brink, I.; Bisse, E.; Epting, T.; Engelhardt, R.

    2005-01-01

    Using human (SK-MEL 23, SK-MEL 24 and G361) and murine (B16) melanoma cell lines, the coregulatory potential of the uptake of the positron emission tomography (PET) tracer, [Fluorine-18]2-fluoro-2-deoxy-D-glucose (F-18 FDG) has been investigated in relationship to tumor characteristics. Comparative studies among the four melanoma cell lines demonstrated that the lowest FDG uptake in SK-MEL 24 corresponded strongly to the data for DT (population doubling time) and MTT (tetrazolium salt) cell viability as well as hexokinase (HK) activity, but was not related to the glucose transporter 1 (GLUT 1) expression level. Furthermore, the FDG uptake in each melanoma cell line measured by cell cycle kinetics was significantly positively correlated to both the proliferation index (PI=S/G 2 M phase fractions) and the cell viability, though with one exception relating to the proliferation index (PI) of the lowest FDG uptake cell line, SK-MEL 24. No positive correlation was found between the expression of GLUT 1 and FDG uptake in any individual cell line. However, the HK activities in SK-MEL 23 and 24 showed considerable positive relationships with FDG uptake. Our present study suggests that both the proliferation rate and the cell viability of melanoma cells may be key factors for FDG uptake and that HK activity, rather than GLUT 1 expression, seems to be a major factor. (author)

  11. Insulin-sparing and fungible effects of E4orf1 combined with an adipocyte-targeting sequence in mouse models of type 1 and type 2 diabetes.

    Science.gov (United States)

    Yoon, I-S; Park, S; Kim, R-H; Ko, H L; Nam, J-H

    2017-10-01

    Obesity impairs glycemic control and causes insulin resistance and type 2 diabetes. Adenovirus 36 (Ad36) infection can increase the uptake of excess glucose from blood into adipocytes by increasing GLUT4 translocation through the Ras-Akt signaling pathway, which bypasses PI3K-Akt-mediated insulin receptor signaling. E4orf1, a viral gene expressed early during Ad36 infection, is responsible for this insulin-sparing effect and may be an alternative target for improving insulin resistance. To deliver the gene to adipocytes only, we connected the adipocyte-targeting sequence (ATS) to the 5' end of E4orf1 (ATS-E4orf1). In vitro transfection of ATS-E4orf1 into preadipocytes activated factors for GLUT4 translocation and adipogenesis to the same extent as did Hemagglutinin (HA)-E4orf1 transfection as positive reference. Moreover, the Transwell migration assay also showed that ATS-E4orf1 secreted by liver cells activated Akt in preadipocytes. We used a hydrodynamic gene delivery technique to deliver ATS-E4orf1 into high-fat diet-fed and streptozotocin-injected mice (disease models of type 2 and type 1 diabetes, respectively). ATS-E4orf1 improved the ability to eliminate excess glucose from the blood and ameliorated liver function in both disease models. These findings suggest that ATS-E4orf1 has insulin-sparing and fungible effects in type 2 and 1 diabetes independent of the presence of insulin.

  12. The prognostic value of the hypoxia markers CA IX and GLUT 1 and the cytokines VEGF and IL 6 in head and neck squamous cell carcinoma treated by radiotherapy ± chemotherapy

    International Nuclear Information System (INIS)

    De Schutter, Harlinde; Landuyt, Willy; Verbeken, Erik; Goethals, Laurence; Hermans, Robert; Nuyts, Sandra

    2005-01-01

    Several parameters of the tumor microenvironment, such as hypoxia, inflammation and angiogenesis, play a critical role in tumor aggressiveness and treatment response. A major question remains if these markers can be used to stratify patients to certain treatment protocols. The purpose of this study was to investigate the inter-relationship and the prognostic significance of several biological and clinicopathological parameters in patients with head and neck squamous cell carcinoma (HNSCC) treated by radiotherapy ± chemotherapy. We used two subgroups of a retrospective series for which CT-determined tumoral perfusion correlated with local control. In the first subgroup (n = 67), immunohistochemistry for carbonic anhydrase IX (CA IX) and glucose transporter-1 (GLUT-1) was performed on the pretreatment tumor biopsy. In the second subgroup (n = 34), enzyme linked immunosorbent assay (ELISA) was used to determine pretreatment levels of the cytokines vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in serum. Correlation was investigated between tumoral perfusion and each of these biological markers, as well as between the markers mutually. The prognostic value of these microenvironmental parameters was also evaluated. For CA IX and GLUT-1, the combined assessment of patients with both markers expressed above the median showed an independent correlation with local control (p = 0.02) and disease-free survival (p = 0.04) with a trend for regional control (p = 0.06). In the second subgroup, IL-6 pretreatment serum level above the median was the only independent predictor of local control (p = 0.009), disease-free survival (p = 0.02) and overall survival (p = 0.005). To our knowledge, we are the first to report a link in HNSCC between IL-6 pretreatment serum levels and radioresistance in vivo. This link is supported by the strong prognostic association of pretreatment IL-6 with local control, known to be the most important parameter to judge radiotherapy

  13. [Value of immunocytochemistry in differential diagnosis of gastric adenocarcinoma, reactive mesothelial cells and malignant epithelial mesothelioma in metastatic effusion fluid].

    Science.gov (United States)

    Lyu, M; Cha, N; Zou, Y F; Leng, J H; Xu, L; Sun, Y; Hao, Y Y

    2018-03-08

    Objective: To investigate the diagnostic value of some antibodies in peritoneal fluid of patients with gastric cancer and malignant epithelioid mesothelioma in serous effusion. Methods: One hundred and eighty-two cases of serous effusion were collected at Jilin Cancer Hospital, from July 2012 to July 2016. The expression of GLUT1, CDX2, Villin, calretinin and WT1 was evaluated using SP immunocytochemical technique in peritoneal fluid samples collected from 98 patients with gastric cancer and 74 patients with reactive mesothelial cells. The expression of GLUT1, calretinin and WT1 was also evaluated in serous effusion from 10 patients with mesothelioma. Results: The sensitivity of GLUT1, CDX2 and Villin in adenocarcinoma cells was 91.8%(90/98), 68.4% (67/98) and 88.8%(87/98), respectively. The specificity was 95.9% (71/74), 100.0%(74/74) and 100.0% (74/74), respectively. The sensitivity of calretinin and WT1 for reactive mesothelium was 93.2% (69/74) and 79.7% (59/74), respectively. The specificity was 96.9% (95/98) and 100.0% (98/98), respectively. The sensitivity of GLUT1, calretinin and WT1 for mesothelioma was 9/10, 9/10 and 7/10. The reactivity of GLUT1, CDX2, Villin, calretinin and WT1 showed a significant difference ( P <0.01) between adenocarcinoma cells and reactive mesothelium. The reactivity of GLUT1 showed a significant difference ( P <0.01) between mesothelioma and reactive mesothelium. Conclusions: The optimal combination is a panel of GLUT1, CDX2, Villin, calretinin and WT1 for differential diagnosis between adenocarcinoma cells and reactive mesothelium in peritoneal fluid of patients with gastric cancer. Whereas GLUT1, calretinin and WT1 is the best for differential diagnosis between reactive mesothelium and mesothelioma in serous effusions.

  14. Toll-like receptor-4 (TLR-4) expression on polymorphonuclear ...

    African Journals Online (AJOL)

    To establish a foundation for further researches on the improvement of polymorphonuclear neutrophil leukocytes (PMN) functions in dairy cow during perinatal period, the counting of PMN, as well as the mRNA and protein expression of toll-like receptor-4 (TLR-4) on PMN was studied during this critical period.

  15. Arachidonic acid and lipoxin A4 attenuate alloxan-induced cytotoxicity to RIN5F cells in vitro and type 1 diabetes mellitus in vivo.

    Science.gov (United States)

    Gundala, Naveen K V; Naidu, Vegi G M; Das, Undurti N

    2017-03-01

    We studied whether polyunsaturated fatty acids (PUFAs) can protect rat insulinoma (RIN5F) cells against alloxan-induced apoptosis in vitro and type 1 diabetes mellitus (type 1 DM) in vivo and if so, mechanism of this beneficial action. In vitro study was conducted using RIN5F cells while in vivo study was performed in Wistar rats. The effect of PUFAs, cyclo-oxygenase and lipoxygenase inhibitors, various eicosanoids and PUFAs metabolites: lipoxin A4 (LXA4), resolvin D2 and protectin against alloxan-induced cytotoxicity to RIN5F cells and type 1 DM was studied. Expression of PDX1, P65 NF-kB and IKB in RIN5F cells and Nrf2, GLUT2, COX2, iNOS protein levels in the pancreatic tissue and plasma glucose, insulin and tumor necrosis factor-α and antioxidants, lipid peroxides and nitric oxide were measured. Of all, arachidonic acid (AA) was found to be the most effective against alloxan-induced cytotoxicity to RIN5F cells and preventing type 1 DM. Both cyclo-oxygenase and lipoxygenase inhibitors did not block the beneficial actions of AA in vitro and in vivo. Alloxan inhibited LXA4 production by RIN5F cells and in alloxan-induced type 1 DM Wistar rats. AA-treatment restored LXA4 levels to normal both in vitro and in vivo. LXA4 protected RIN5F cells against alloxan-induced cytotoxicity and prevented type 1 DM and restored expression of Nrf2, Glut2, COX2, and iNOS genes and abnormal antioxidants to near normal. AA seems to bring about its beneficial actions against alloxan-induced cytotoxicity and type 1 DM by enhancing the production of LXA4. © 2016 BioFactors, 43(2):251-271, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

  16. Regulation and Gene Expression Profiling of NKG2D Positive Human Cytomegalovirus-Primed CD4+ T-Cells

    Science.gov (United States)

    Jensen, Helle; Folkersen, Lasse; Skov, Søren

    2012-01-01

    NKG2D is a stimulatory receptor expressed by natural killer (NK) cells, CD8+ T-cells, and γδ T-cells. NKG2D expression is normally absent from CD4+ T-cells, however recently a subset of NKG2D+ CD4+ T-cells has been found, which is specific for human cytomegalovirus (HCMV). This particular subset of HCMV-specific NKG2D+ CD4+ T-cells possesses effector-like functions, thus resembling the subsets of NKG2D+ CD4+ T-cells found in other chronic inflammations. However, the precise mechanism leading to NKG2D expression on HCMV-specific CD4+ T-cells is currently not known. In this study we used genome-wide analysis of individual genes and gene set enrichment analysis (GSEA) to investigate the gene expression profile of NKG2D+ CD4+ T-cells, generated from HCMV-primed CD4+ T-cells. We show that the HCMV-primed NKG2D+ CD4+ T-cells possess a higher differentiated phenotype than the NKG2D– CD4+ T-cells, both at the gene expression profile and cytokine profile. The ability to express NKG2D at the cell surface was primarily determined by the activation or differentiation status of the CD4+ T-cells and not by the antigen presenting cells. We observed a correlation between CD94 and NKG2D expression in the CD4+ T-cells following HCMV stimulation. However, knock-down of CD94 did not affect NKG2D cell surface expression or signaling. In addition, we show that NKG2D is recycled at the cell surface of activated CD4+ T-cells, whereas it is produced de novo in resting CD4+ T-cells. These findings provide novel information about the gene expression profile of HCMV-primed NKG2D+ CD4+ T-cells, as well as the mechanisms regulating NKG2D cell surface expression. PMID:22870231

  17. Regulation and gene expression profiling of NKG2D positive human cytomegalovirus-primed CD4+ T-cells.

    Directory of Open Access Journals (Sweden)

    Helle Jensen

    Full Text Available NKG2D is a stimulatory receptor expressed by natural killer (NK cells, CD8(+ T-cells, and γδ T-cells. NKG2D expression is normally absent from CD4(+ T-cells, however recently a subset of NKG2D(+ CD4(+ T-cells has been found, which is specific for human cytomegalovirus (HCMV. This particular subset of HCMV-specific NKG2D(+ CD4(+ T-cells possesses effector-like functions, thus resembling the subsets of NKG2D(+ CD4(+ T-cells found in other chronic inflammations. However, the precise mechanism leading to NKG2D expression on HCMV-specific CD4(+ T-cells is currently not known. In this study we used genome-wide analysis of individual genes and gene set enrichment analysis (GSEA to investigate the gene expression profile of NKG2D(+ CD4(+ T-cells, generated from HCMV-primed CD4(+ T-cells. We show that the HCMV-primed NKG2D(+ CD4(+ T-cells possess a higher differentiated phenotype than the NKG2D(- CD4(+ T-cells, both at the gene expression profile and cytokine profile. The ability to express NKG2D at the cell surface was primarily determined by the activation or differentiation status of the CD4(+ T-cells and not by the antigen presenting cells. We observed a correlation between CD94 and NKG2D expression in the CD4(+ T-cells following HCMV stimulation. However, knock-down of CD94 did not affect NKG2D cell surface expression or signaling. In addition, we show that NKG2D is recycled at the cell surface of activated CD4(+ T-cells, whereas it is produced de novo in resting CD4(+ T-cells. These findings provide novel information about the gene expression profile of HCMV-primed NKG2D(+ CD4(+ T-cells, as well as the mechanisms regulating NKG2D cell surface expression.

  18. Aquaporin Expression and Water Transport Pathways inside Leaves Are Affected by Nitrogen Supply through Transpiration in Rice Plants

    Directory of Open Access Journals (Sweden)

    Lei Ding

    2018-01-01

    Full Text Available The photosynthetic rate increases under high-N supply, resulting in a large CO2 transport conductance in mesophyll cells. It is less known that water movement is affected by nitrogen supply in leaves. This study investigated whether the expression of aquaporin and water transport were affected by low-N (0.7 mM and high-N (7 mM concentrations in the hydroponic culture of four rice varieties: (1 Shanyou 63 (SY63, a hybrid variant of the indica species; (2 Yangdao 6 (YD6, a variant of indica species; (3 Zhendao 11 (ZD11, a hybrid variant of japonica species; and (4 Jiuyou 418 (JY418, another hybrid of the japonica species. Both the photosynthetic and transpiration rate were increased by the high-N supply in the four varieties. The expressions of aquaporins, plasma membrane intrinsic proteins (PIPs, and tonoplast membrane intrinsic protein (TIP were higher in high-N than low-N leaves, except in SY63. Leaf hydraulic conductance (Kleaf was lower in high-N than low-N leaves in SY63, while Kleaf increased under high-N supply in the YD6 variant. Negative correlations were observed between the expression of aquaporin and the transpiration rate in different varieties. Moreover, there was a significant negative correlation between transpiration rate and intercellular air space. In conclusion, the change in expression of aquaporins could affect Kleaf and transpiration. A feedback effect of transpiration would regulate aquaporin expression. The present results imply a coordination of gas exchange with leaf hydraulic conductance.

  19. Impairment of brain endothelial glucose transporter by methamphetamine causes blood-brain barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Murrin L Charles

    2011-03-01

    Full Text Available Abstract Background Methamphetamine (METH, an addictive psycho-stimulant drug with euphoric effect is known to cause neurotoxicity due to oxidative stress, dopamine accumulation and glial cell activation. Here we hypothesized that METH-induced interference of glucose uptake and transport at the endothelium can disrupt the energy requirement of the blood-brain barrier (BBB function and integrity. We undertake this study because there is no report of METH effects on glucose uptake and transport across the blood-brain barrier (BBB to date. Results In this study, we demonstrate that METH-induced disruption of glucose uptake by endothelium lead to BBB dysfunction. Our data indicate that a low concentration of METH (20 μM increased the expression of glucose transporter protein-1 (GLUT1 in primary human brain endothelial cell (hBEC, main component of BBB without affecting the glucose uptake. A high concentration of 200 μM of METH decreased both the glucose uptake and GLUT1 protein levels in hBEC culture. Transcription process appeared to regulate the changes in METH-induced GLUT1 expression. METH-induced decrease in GLUT1 protein level was associated with reduction in BBB tight junction protein occludin and zonula occludens-1. Functional assessment of the trans-endothelial electrical resistance of the cell monolayers and permeability of dye tracers in animal model validated the pharmacokinetics and molecular findings that inhibition of glucose uptake by GLUT1 inhibitor cytochalasin B (CB aggravated the METH-induced disruption of the BBB integrity. Application of acetyl-L-carnitine suppressed the effects of METH on glucose uptake and BBB function. Conclusion Our findings suggest that impairment of GLUT1 at the brain endothelium by METH may contribute to energy-associated disruption of tight junction assembly and loss of BBB integrity.

  20. Intracellular ascorbic acid inhibits transport of glucose by neurons, but not by astrocytes.

    Science.gov (United States)

    Castro, Maite A; Pozo, Miguel; Cortés, Christian; García, María de Los Angeles; Concha, Ilona I; Nualart, Francisco

    2007-08-01

    It has been demonstrated that glutamatergic activity induces ascorbic acid (AA) depletion in astrocytes. Additionally, different data indicate that AA may inhibit glucose accumulation in primary cultures of rat hippocampal neurons. Thus, our hypothesis postulates that AA released from the astrocytes during glutamatergic synaptic activity may inhibit glucose uptake by neurons. We observed that cultured neurons express the sodium-vitamin C cotransporter 2 and the facilitative glucose transporters (GLUT) 1 and 3, however, in hippocampal brain slices GLUT3 was the main transporter detected. Functional activity of GLUTs was confirmed by means of kinetic analysis using 2-deoxy-d-glucose. Therefore, we showed that AA, once accumulated inside the cell, inhibits glucose transport in both cortical and hippocampal neurons in culture. Additionally, we showed that astrocytes are not affected by AA. Using hippocampal slices, we observed that upon blockade of monocarboxylate utilization by alpha-cyano-4-hydroxycinnamate and after glucose deprivation, glucose could rescue neuronal response to electrical stimulation only if AA uptake is prevented. Finally, using a transwell system of separated neuronal and astrocytic cultures, we observed that glutamate can reduce glucose transport in neurons only in presence of AA-loaded astrocytes, suggesting the essential role of astrocyte-released AA in this effect.

  1. Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions.

    Science.gov (United States)

    Pinho, Andreia V; Mawson, Amanda; Gill, Anthony; Arshi, Mehreen; Warmerdam, Max; Giry-Laterriere, Marc; Eling, Nils; Lie, Triyana; Kuster, Evelyne; Camargo, Simone; Biankin, Andrew V; Wu, Jianmin; Rooman, Ilse

    2016-11-15

    Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered.To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH.The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival.These findings open perspectives for novel targeted therapies in pancreatic cancer.

  2. Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions

    Science.gov (United States)

    Pinho, Andreia V.; Mawson, Amanda; Gill, Anthony; Arshi, Mehreen; Warmerdam, Max; Giry-Laterriere, Marc; Eling, Nils; Lie, Triyana; Kuster, Evelyne; Camargo, Simone; Biankin, Andrew V.; Wu, Jianmin; Rooman, Ilse

    2016-01-01

    Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered. To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH. The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival. These findings open perspectives for novel targeted therapies in pancreatic cancer. PMID:27494892

  3. Conventional kinesin KIF5B mediates adiponectin secretion in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ju, E-mail: juzi.cui@gmail.com [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Pang, Jing; Lin, Ya-Jun; Jiang, Ping; Gong, Huan [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Wang, Zai [Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing (China); Li, Jian; Cai, Jian-Ping [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Huang, Jian-Dong, E-mail: jdhuang@hku.hk [School of Biomedical Sciences and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Pokfulam (Hong Kong); The Centre for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Shenzhen (China); Zhang, Tie-Mei, E-mail: tmzhang126@126.com [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China)

    2016-08-05

    Insulin stimulates adiponectin secretion and glucose transporter type 4 (GLUT4) translocation in adipocyte to regulate metabolism homeostasis. Similar to GLUT4 translocation, intracellular trafficking and release of adiponectin in adipocytes relies on the trans-Golgi network and endosomal system. Recent studies show that the heavy chain of conventional kinesin (KIF5B) mediates GLUT4 translocation in murine 3T3-L1 adipocytes, however, the motor machinery involved in mediating intracellular trafficking and release of adiponectin is unknown. Here, we examined the role of KIF5B in the regulation of adiponectin secretion. The KIF5B level was up-regulated during 3T3-L1 adipogenesis. This increase in cytosolic KIF5B was synchronized with the induction of adiponectin. Endogenous KIF5B and adiponectin were partially colocalized at the peri-nuclear and cytosolic regions. In addition, adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. Knockdown of KIF5B resulted in a marked inhibition of adiponectin secretion and overexpression of KIF5B enhanced adiponectin release, whereas leptin secretion was not affected by changes in KIF5B expression. These data suggest that the secretion of adiponectin, but not leptin, is dependent on functional KIF5B. - Highlights: • The KIF5B level was up regulated during 3T3-L1 adipogenesis. • Endogenous KIF5B and adiponectin were partially colicalized. • Adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. • The secretion of adiponectin, but not leptin, is dependent on functional KIF5B.

  4. Conventional kinesin KIF5B mediates adiponectin secretion in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Cui, Ju; Pang, Jing; Lin, Ya-Jun; Jiang, Ping; Gong, Huan; Wang, Zai; Li, Jian; Cai, Jian-Ping; Huang, Jian-Dong; Zhang, Tie-Mei

    2016-01-01

    Insulin stimulates adiponectin secretion and glucose transporter type 4 (GLUT4) translocation in adipocyte to regulate metabolism homeostasis. Similar to GLUT4 translocation, intracellular trafficking and release of adiponectin in adipocytes relies on the trans-Golgi network and endosomal system. Recent studies show that the heavy chain of conventional kinesin (KIF5B) mediates GLUT4 translocation in murine 3T3-L1 adipocytes, however, the motor machinery involved in mediating intracellular trafficking and release of adiponectin is unknown. Here, we examined the role of KIF5B in the regulation of adiponectin secretion. The KIF5B level was up-regulated during 3T3-L1 adipogenesis. This increase in cytosolic KIF5B was synchronized with the induction of adiponectin. Endogenous KIF5B and adiponectin were partially colocalized at the peri-nuclear and cytosolic regions. In addition, adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. Knockdown of KIF5B resulted in a marked inhibition of adiponectin secretion and overexpression of KIF5B enhanced adiponectin release, whereas leptin secretion was not affected by changes in KIF5B expression. These data suggest that the secretion of adiponectin, but not leptin, is dependent on functional KIF5B. - Highlights: • The KIF5B level was up regulated during 3T3-L1 adipogenesis. • Endogenous KIF5B and adiponectin were partially colicalized. • Adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. • The secretion of adiponectin, but not leptin, is dependent on functional KIF5B.

  5. Differential expression of the Slc4 bicarbonate transporter family in murine corneal endothelium and cell culture.

    Science.gov (United States)

    Shei, William; Liu, Jun; Htoon, Hla M; Aung, Tin; Vithana, Eranga N

    2013-01-01

    To characterize the relative expression levels of all the solute carrier 4 (Slc4) transporter family members (Slc4a1-Slc4a11) in murine corneal endothelium using real-time quantitative (qPCR), to identify further important members besides Slc4a11 and Slc4a4, and to explore how close to the baseline levels the gene expressions remain after cells have been subjected to expansion and culture. Descemet's membrane-endothelial layers of 8-10-week-old C57BL6 mice were stripped from corneas and used for both primary cell culture and direct RNA extraction. Total RNA (from uncultured cells as well as cultured cells at passages 2 and 7) was reverse transcribed, and the cDNA was used for real time qPCR using specific primers for all the Slc4 family members. The geNorm method was applied to determine the most stable housekeeping genes and normalization factor, which was calculated from multiple housekeeping genes for more accurate and robust quantification. qPCR analyses revealed that all Slc4 bicarbonate transporter family members were expressed in mouse corneal endothelium. Slc4a11 showed the highest expression, which was approximately three times higher than that of Slc4a4 (3.4±0.3; p=0.004). All Slc4 genes were also expressed in cultured cells, and interestingly, the expression of Slc4a11 in cultured cells was significantly reduced by approximately 20-fold (0.05±0.001; p=0.000001) in early passage and by approximately sevenfold (0.14±0.002; p=0.000002) in late passage cells. Given the known involvement of SLC4A4 and SLC4A11 in corneal dystrophies, we speculate that the other two highly expressed genes in the uncultured corneal endothelium, SLC4A2 and SLC4A7, are worthy of being considered as potential candidate genes for corneal endothelial diseases. Moreover, as cell culture can affect expression levels of Slc4 genes, caution and careful design of experiments are necessary when undertaking studies of Slc4-mediated ion transport in cultured cells.

  6. Implicit motives predict affective responses to emotional expressions

    Directory of Open Access Journals (Sweden)

    Andreas G. Rösch

    2013-12-01

    Full Text Available We explored the influence of implicit motives and activity inhibition on subjectively experienced affect in response to the presentation of six different facial expressions of emotion (FEEs; anger, disgust, fear, happiness, sadness, and surprise and neutral faces from the NimStim set of facial expressions (Tottenham et al., 2009. Implicit motives and activity inhibition were assessed using a Picture Story Exercise (Schultheiss et al., 2009b. Ratings of subjectively experienced affect (arousal and valence were assessed using Self-Assessment Manikins (Bradley and Lang, 1994 in a sample of 84 participants. We found that people with either a strong implicit power or achievement motive experienced stronger arousal, while people with a strong affiliation motive experienced less aroused and felt more unpleasant across emotions. Additionally, we obtained significant power motive × activity inhibition interactions for arousal ratings in response to FEEs and neutral faces. Participants with a strong power motive and weak activity inhibition experienced stronger arousal after the presentation of neutral faces but no additional increase in arousal after the presentation of FEEs. Participants with a strong power motive and strong activity inhibition (inhibited power motive did not feel aroused by neutral faces. However, their arousal increased in response to all FEEs with the exception of happy faces, for which their subjective arousal decreased. These more differentiated reaction pattern of individuals with an inhibited power motive suggest that they engage in a more socially adaptive manner of responding to different FEEs. Our findings extend established links between implicit motives and affective processes found at the procedural level to declarative reactions to FEEs. Implications are discussed with respect to dual-process models of motivation and research in motive congruence.

  7. The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells

    DEFF Research Database (Denmark)

    Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe

    2009-01-01

    We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell......-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However......, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell...

  8. Metal ion toxins and brain aquaporin-4 expression: an overview

    Directory of Open Access Journals (Sweden)

    Adriana eXimenes-Da-Silva

    2016-06-01

    Full Text Available Metal ions such as iron, zinc, and manganese are essential to metabolic functions, protein synthesis, neurotransmission, and antioxidant neuroprotective mechanisms. Conversely, non-essential metals such as mercury and lead are sources of human intoxication due to occupational activities or environmental contamination. Essential or non-essential metal accumulation in the central nervous system (CNS results in changes in blood-brain barrier (BBB permeability, as well as triggering microglia activation and astrocyte reactivity and changing water transport through the cells, which could result in brain swelling. Aquaporin-4 is the main water channel in the CNS, is expressed in astrocyte foot processes in brain capillaries and along the circumventricular epithelium in the ventricles, and has important physiological functions in maintaining brain osmotic homeostasis and supporting brain excitability through regulation of the extracellular space. Some evidence has pointed to a role of AQP4 during metal intoxication in the brain, where it may act in a dual form as a neuroprotector or a mediator of the development of oxidative stress in neurons and astrocytes, resulting in brain swelling and neuronal damage. This mini-review presents the way some metal ions affect changes in AQP4 expression in the CNS and discuss the ways in which water transport in brain cells can be involved in brain damage.

  9. Characterization, expression profiles, intracellular distribution and association analysis of porcine PNAS-4 gene with production traits

    Directory of Open Access Journals (Sweden)

    Wang Heng

    2008-06-01

    Full Text Available Abstract Background In a previous screen to identify differentially expressed genes associated with embryonic development, the porcine PNAS-4 gene had been found. Considering differentially expressed genes in early stages of muscle development are potential candidate genes to improve meat quality and production efficiency, we determined how porcine PNAS-4 gene regulates meat production. Therefore, this gene has been sequenced, expression analyzed and associated with meat production traits. Results We cloned the full-length cDNA of porcine PNAS-4 gene encoding a protein of 194 amino acids which was expressed in the Golgi complex. This gene was mapped to chromosome 10, q11–16, in a region of conserved synteny with human chromosome 1 where the human homologous gene was localized. Real-time PCR revealed that PNAS-4 mRNA was widely expressed with highest expression levels in skeletal muscle followed by lymph, liver and other tissues, and showed a down-regulated expression pattern during prenatal development while a up-regulated expression pattern after weaning. Association analysis revealed that allele C of SNP A1813C was prevalent in Chinese indigenous breeds whereas A was dominant allele in Landrace and Large White, and the pigs with homozygous CC had a higher fat content than those of the pigs with other genotypes (P Conclusion Porcine PNAS-4 protein tagged with green fluorescent protein accumulated in the Golgi complex, and its mRNA showed a widespread expression across many tissues and organs in pigs. It may be an important factor affecting the meat production efficiency, because its down-regulated expression pattern during early embryogenesis suggests involvement in increase of muscle fiber number. In addition, the SNP A1813C associated with fat traits might be a genetic marker for molecular-assisted selection in animal breeding.

  10. SOX4 expression is associated with treatment failure and chemoradioresistance in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Yoon, Tae Mi; Kim, Sun-Ae; Cho, Wan Seok; Lee, Dong Hoon; Lee, Joon Kyoo; Park, Young-Lan; Lee, Kyung-Hwa; Lee, Jae Hyuk; Kweon, Sun-Seog; Chung, Ik-Joo; Lim, Sang Chul; Joo, Young-Eun

    2015-01-01

    In humans, sex-determining region-Y (SRY) related high-mobility-group box 4 (SOX4) is linked to development and tumorigenesis. SOX4 is over-expressed in several cancers and has prognostic significance. This study evaluated whether SOX4 affects oncogenic behavior and chemoradiotherapy response in head and neck squamous cell carcinoma (HNSCC) cells, and documented the relationship between its expression and prognosis in oral squamous cell carcinoma (OSCC). We used small interfering RNA in HNSCC cells to evaluate the effect of SOX4 on cell proliferation, apoptosis, chemoradiation-induced apoptosis, invasion, and migration. SOX4 expression in OSCC tissues was investigated by immunohistochemistry. SOX4 knockdown (KO) decreased cell proliferation and induced apoptosis by activating caspases-3 and −7, and poly-ADP ribose polymerase and suppressing X-linked inhibitor of apoptosis protein in HNSCC cells; it also enhanced radiation/cisplatin-induced apoptosis; and suppressed tumor cell invasion and migration. Immunostaining showed SOX4 protein was significantly increased in OSCC tissues compared with adjacent normal mucosa. SOX4 expression was observed in 51.8 % of 85 OSCC tissues, and was significantly correlated with treatment failure (P = 0.032) and shorter overall survival (P = 0.036) in patients with OSCC. SOX4 may contribute to oncogenic phenotypes of HNSCC cells by promoting cell survival and causing chemoradioresistance. It could be a potential prognostic marker for OSCC. The online version of this article (doi:10.1186/s12885-015-1875-8) contains supplementary material, which is available to authorized users

  11. Common inversion polymorphism at 17q21.31 affects expression of multiple genes in tissue-specific manner.

    Science.gov (United States)

    de Jong, Simone; Chepelev, Iouri; Janson, Esther; Strengman, Eric; van den Berg, Leonard H; Veldink, Jan H; Ophoff, Roel A

    2012-09-06

    Chromosome 17q21.31 contains a common inversion polymorphism of approximately 900 kb in populations with European ancestry. Two divergent MAPT haplotypes, H1 and H2 are described with distinct linkage disequilibrium patterns across the region reflecting the inversion status at this locus. The MAPT H1 haplotype has been associated with progressive supranuclear palsy, corticobasal degeneration, Parkinson's disease and Alzheimer's disease, while the H2 is linked to recurrent deletion events associated with the 17q21.31 microdeletion syndrome, a disease characterized by developmental delay and learning disability. In this study, we investigate the effect of the inversion on the expression of genes in the 17q21.31 region. We find the expression of several genes in and at the borders of the inversion to be affected; specific either to whole blood or different regions of the human brain. The H1 haplotype was found to be associated with an increased expression of LRRC37A4, PLEKH1M and MAPT. In contrast, a decreased expression of MGC57346, LRRC37A and CRHR1 was associated with H1. Studies thus far have focused on the expression of MAPT in the inversion region. However, our results show that the inversion status affects expression of other genes in the 17q21.31 region as well. Given the link between the inversion status and different neurological diseases, these genes may also be involved in disease pathology, possibly in a tissue-specific manner.

  12. Negative Effects of High Glucose Exposure in Human Gonadotropin-Releasing Hormone Neurons

    Directory of Open Access Journals (Sweden)

    Annamaria Morelli

    2013-01-01

    Full Text Available Metabolic disorders are often associated with male hypogonadotropic hypogonadism, suggesting that hypothalamic defects involving GnRH neurons may impair the reproductive function. Among metabolic factors hyperglycemia has been implicated in the control of the reproductive axis at central level, both in humans and in animal models. To date, little is known about the direct effects of pathological high glucose concentrations on human GnRH neurons. In this study, we investigated the high glucose effects in the human GnRH-secreting FNC-B4 cells. Gene expression profiling by qRT-PCR, confirmed that FNC-B4 cells express GnRH and several genes relevant for GnRH neuron function (KISS1R, KISS1, sex steroid and leptin receptors, FGFR1, neuropilin 2, and semaphorins, along with glucose transporters (GLUT1, GLUT3, and GLUT4. High glucose exposure (22 mM; 40 mM significantly reduced gene and protein expression of GnRH, KISS1R, KISS1, and leptin receptor, as compared to normal glucose (5 mM. Consistent with previous studies, leptin treatment significantly induced GnRH mRNA expression at 5 mM glucose, but not in the presence of high glucose concentrations. In conclusion, our findings demonstrate a deleterious direct contribution of high glucose on human GnRH neurons, thus providing new insights into pathogenic mechanisms linking metabolic disorders to reproductive dysfunctions.

  13. Thermal properties of silica-filled high density polyethylene composites compatibilized with glut palmitate

    Science.gov (United States)

    Samsudin, Dalina; Ismail, Hanafi; Othman, Nadras; Hamid, Zuratul Ain Abdul

    2017-07-01

    A study of thermal properties resulting from the utilization of Glut Palmitate (GP) on the silica filled high density polyethylene (HDPE) composites was carried out. The composites with the incorporation of GP at 0.5, 1.0, 2.0 and 3.0 phr were prepared by using an internal mixer at the temperature 180 °C and the rotor speed of 50 rpm. The thermal behaviours of the composites were then investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was found that the crystallinity and the thermal stability of the composites increased with the incorporation of GP. The highest crystallinity contents and decomposition temperatures were observed at the 1 phr GP loading.

  14. Interspecies Systems Biology Uncovers Metabolites Affecting C. elegans Gene Expression and Life History Traits

    Science.gov (United States)

    Watson, Emma; MacNeil, Lesley T.; Ritter, Ashlyn D.; Yilmaz, L. Safak; Rosebrock, Adam P.; Caudy, Amy A.; Walhout, Albertha J. M.

    2014-01-01

    SUMMARY Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here we used an interspecies systems biology approach with Caenorhabditis elegans and two if its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal’s gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development and reduces fertility, but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology. PMID:24529378

  15. Facial Expressivity at 4 Months: A Context by Expression Analysis.

    Science.gov (United States)

    Bennett, David S; Bendersky, Margaret; Lewis, Michael

    2002-01-01

    The specificity predicted by differential emotions theory (DET) for early facial expressions in response to 5 different eliciting situations was studied in a sample of 4-month-old infants (n = 150). Infants were videotaped during tickle, sour taste, jack-in-the-box, arm restraint, and masked-stranger situations and their expressions were coded second by second. Infants showed a variety of facial expressions in each situation; however, more infants exhibited positive (joy and surprise) than negative expressions (anger, disgust, fear, and sadness) across all situations except sour taste. Consistent with DET-predicted specificity, joy expressions were the most common in response to tickling, and were less common in response to other situations. Surprise expressions were the most common in response to the jack-in-the-box, as predicted, but also were the most common in response to the arm restraint and masked-stranger situations, indicating a lack of specificity. No evidence of predicted specificity was found for anger, disgust, fear, and sadness expressions. Evidence of individual differences in expressivity within situations, as well as stability in the pattern across situations, underscores the need to examine both child and contextual factors in studying emotional development. The results provide little support for the DET postulate of situational specificity and suggest that a synthesis of differential emotions and dynamic systems theories of emotional expression should be considered.

  16. Quercetin ameliorates chronic unpredicted stress-induced behavioral dysfunction in male Swiss albino mice by modulating hippocampal insulin signaling pathway.

    Science.gov (United States)

    Mehta, Vineet; Singh, Tiratha Raj; Udayabanu, Malairaman

    2017-12-01

    Chronic stress is associated with impaired neurogenesis, neurodegeneration and behavioral dysfunction, whereas the mechanism underlying stress-mediated neurological complications is still not clear. In the present study, we aimed to investigate whether chronic unpredicted stress (CUS) mediated neurological alterations are associated with impaired hippocampal insulin signaling or not, and studied the effect of quercetin in this scenario. Male Swiss albino mice were subjected to 21day CUS, during which 30mg/kg quercetin treatment was given orally. After 21days, behavioral functions were evaluated in terms of locomotor activity (Actophotometer), muscle coordination (Rota-rod), depression (Tail Suspension Test (TST), Forced Swim Test (FST)) and memory performance (Passive-avoidance step-down task (PASD)). Further, hippocampal insulin signaling was evaluated in terms of protein expression of insulin, insulin receptor (IR) and glucose transporter 4 (GLUT-4) and neurogenesis was evaluated in terms of doublecortin (DCX) expression. 21day CUS significantly impaired locomotion and had no effect on muscle coordination. Stressed animals were depressed and showed markedly impaired memory functions. Quercetin treatment significantly improvement stress-mediated behavior dysfunction as indicated by improved locomotion, lesser immobility time and greater frequency of upward turning in TST and FST and increased transfer latency on the day 2 (short-term memory) and day 5 (long-term memory) in PASD test. We observed significantly higher IR expression and significantly lower GLUT-4 expression in the hippocampus of stressed animals, despite of nonsignificant difference in insulin levels. Further, chronic stress impaired hippocampal neurogenesis, as indicated by the significantly reduced levels of hippocampal DCX expression. Quercetin treatment significantly lowered insulin and IR expression and significantly enhanced GLUT-4 and DCX expression in the hippocampus, when compared to CUS. In

  17. High USP6NL levels in breast cancer sustain chronic AKT phosphorylation and GLUT1 stability fueling aerobic glycolysis.

    Science.gov (United States)

    Avanzato, Daniele; Pupo, Emanuela; Ducano, Nadia; Isella, Claudio; Bertalot, Giovanni; Luise, Chiara; Pece, Salvatore; Bruna, Alejandra; Rueda, Oscar M; Caldas, Carlos; Di Fiore, Pier Paolo; Sapino, Anna; Lanzetti, Letizia

    2018-04-24

    USP6NL, also named RN-tre, is a GTPase activating protein (GAP) involved in control of endocytosis and signal transduction. Here we report that USP6NL is overexpressed in breast cancer (BC), mainly of the basal-like/integrative cluster 10 subtype. Increased USP6NL levels were accompanied by gene amplification and were associated with worse prognosis in the METABRIC dataset, retaining prognostic value in multivariable analysis. High levels of USP6NL in BC cells delayed endocytosis and degradation of the epidermal growth factor receptor (EGFR), causing chronic AKT activation. In turn, AKT stabilized the glucose transporter GLUT1 at the plasma membrane, increasing aerobic glycolysis. In agreement, elevated USP6NL sensitized BC cells to glucose deprivation, indicating that their glycolytic capacity relies on this protein. Depletion of USP6NL accelerated EGFR/AKT downregulation and GLUT1 degradation, impairing cell proliferation exclusively in BC cells that harbored increased levels of USP6NL. Overall, these findings argue that USP6NL overexpression generates a metabolic rewiring that is essential to foster the glycolytic demand of BC cells and promote their proliferation. Copyright ©2018, American Association for Cancer Research.

  18. The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells.

    Science.gov (United States)

    Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe; Sosa-Pineda, Beatriz; Dussaud, Sébastien; Billestrup, Nils; Madsen, Ole D; Serup, Palle; Heimberg, Harry; Mansouri, Ahmed

    2009-08-07

    We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell mass and curing diabetes in animals that have been chemically depleted of beta cells.

  19. Human ApoE Isoforms Differentially Modulate Glucose and Amyloid Metabolic Pathways in Female Brain: Evidence of the Mechanism of Neuroprotection by ApoE2 and Implications for Alzheimer's Disease Prevention and Early Intervention.

    Science.gov (United States)

    Keeney, Jeriel Thomas-Richard; Ibrahimi, Shaher; Zhao, Liqin

    2015-01-01

    Three major genetic isoforms of apolipoprotein E (ApoE), ApoE2, ApoE3, and ApoE4, exist in humans and lead to differences in susceptibility to Alzheimer's disease (AD). This study investigated the impact of human ApoE isoforms on brain metabolic pathways involved in glucose utilization and amyloid-β (Aβ) degradation, two major areas that are significantly perturbed in preclinical AD. Hippocampal RNA samples from middle-aged female mice with targeted human ApoE2, ApoE3, and ApoE4 gene replacement were comparatively analyzed with a qRT-PCR custom array for the expression of 85 genes involved in insulin/insulin-like growth factor (Igf) signaling. Consistent with its protective role against AD, ApoE2 brain exhibited the most metabolically robust profile among the three ApoE genotypes. When compared to ApoE2 brain, both ApoE3 and ApoE4 brains exhibited markedly reduced levels of Igf1, insulin receptor substrates (Irs), and facilitated glucose transporter 4 (Glut4), indicating reduced glucose uptake. Additionally, ApoE4 brain exhibited significantly decreased Pparg and insulin-degrading enzyme (Ide), indicating further compromised glucose metabolism and Aβ dysregulation associated with ApoE4. Protein analysis showed significantly decreased Igf1, Irs, and Glut4 in ApoE3 brain, and Igf1, Irs, Glut4, Pparg, and Ide in ApoE4 brain compared to ApoE2 brain. These data provide the first documented evidence that human ApoE isoforms differentially affect brain insulin/Igf signaling and downstream glucose and amyloid metabolic pathways, illustrating a potential mechanism for their differential risk in AD. A therapeutic strategy that enhances brain insulin/Igf1 signaling activity to a more robust ApoE2-like phenotype favoring both energy production and amyloid homeostasis holds promise for AD prevention and early intervention.

  20. Mechanism of Butyrate Stimulation of Triglyceride Storage and Adipokine Expression during Adipogenic Differentiation of Porcine Stromovascular Cells.

    Directory of Open Access Journals (Sweden)

    Hui Yan

    Full Text Available Short chain fatty acids (SCFA, products of microbial fermentation of dietary fiber, exert multiple metabolic effects in cells. Previously, we had demonstrated that soluble fiber influenced fat mass accumulation, gut microbial community structure and SCFA production in pigs. The current study was designed to identify effects of SCFA treatment during adipogenic differentiation of porcine stromovascular cells on lipid metabolism and adipokine expression. Differentiating cells were treated with varying concentrations of butyrate. Results show that butyrate treatment enhanced adipogenesis and lipid accumulation, perhaps through upregulation of glucose uptake and de novo lipogenesis and other mechanisms that include induction of SREBP-1c, C/EBPα/β, GLUT4, LPL, PPARγ, GPAT4, DGAT1 and DGAT2 expression. In addition, butyrate induced adiponectin expression, resulting in activation of downstream target genes, such as AMPK and AKT. Activation of AMPK by butyrate led to phosphorylation of ACC. Although increased ACO gene expression was seen with butyrate treatment, experiments with the peroxisomal fatty acid inhibitor, thioridazine, suggest that butyrate may have an inhibitory effect on peroxisomal fatty acid oxidation. Our studies also provide evidence that butyrate may inhibit lipolysis, perhaps in an FFAR3-dependent manner. Therefore, this study presents a novel paradigm for butyrate action in adipocytes and shows that adipocytes are capable of utilizing butyrate, leading to increased expression of adiponectin for enhanced glucose uptake and improved insulin sensitivity.

  1. Diabetic microvascular complications are not associated with two polymorphisms in the GLUT-1 and PC-1 genes regulating glucose metabolism in Caucasian type 1 diabetic patients

    DEFF Research Database (Denmark)

    Tarnow, L; Grarup, N; Hansen, T

    2001-01-01

    BACKGROUND: An XbaI polymorphism in the gene encoding the glucose transporter, GLUT-1, is associated with development of diabetic nephropathy in Chinese type 2 diabetic patients. In addition, an amino acid variant (K121Q) in the gene encoding the glycoprotein plasma cell differentiating antigen (PC...... men/77 women, age 40.9+/-9.6 years, diabetes duration 27+/-8 years) and type 1 diabetic patients with persistent normoalbuminuria (118 men/74 women, age 42.7+/-10.2 years, diabetes duration 26+/-9 years). Proliferative retinopathy was present in 156 patients (40%), while 67 patients (17%) had....... CONCLUSIONS: Neither the PC-1 K121Q nor the GLUT-1 XbaI polymorphism contribute to the genetic susceptibility of diabetic microvascular complications in Danish type 1 diabetic patients....

  2. GABA dramatically improves glucose tolerance in streptozotocin-induced diabetic rats fed with high-fat diet.

    Science.gov (United States)

    Sohrabipour, Shahla; Sharifi, Mohammad Reza; Talebi, Ardeshir; Sharifi, Mohammadreza; Soltani, Nepton

    2018-05-05

    Skeletal muscle, hepatic insulin resistance, and beta cell dysfunction are the characteristic pathophysiological features of type 2 diabetes mellitus. GABA has an important role in pancreatic islet cells. The present study attempted to clarify the possible mechanism of GABA to improve glucose tolerance in a model of type 2 diabetes mellitus in rats. Fifty Wistar rats were divided into five groups: NDC that was fed the normal diet, CD which received a high-fat diet with streptozotocin, CD-GABA animals that received GABA via intraperitoneal injection, plus CD-Ins1 and CD-Ins2 groups which were treated with low and high doses of insulin, respectively. Body weight and blood glucose were measured weekly. Intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test (ITT), urine volume, amount of water drinking, and food intake assessments were performed monthly. The hyperinsulinemic euglycemic clamp was done for assessing insulin resistance. Plasma insulin and glucagon were measured. Abdominal fat was measured. Glucagon receptor, Glucose 6 phosphatase, Phosphoenolpyruvate carboxykinase genes expression were evaluated in liver and Glucose transporter 4 (GLUT4) genes expression and protein translocation were evaluated in the muscle. GABA or insulin therapy improved blood glucose, insulin level, IPGTT, ITT, gluconeogenesis pathway, Glucagon receptor, body weight and body fat in diabetic rats. GLUT4 gene and protein expression increased. GABA whose beneficial effect was comparable to that of insulin, also increased glucose infusion rate during an euglycemic clamp. GABA could improve insulin resistance via rising GLUT4 and also decreasing the gluconeogenesis pathway and Glucagon receptor gene expression. Copyright © 2018. Published by Elsevier B.V.

  3. PAI-1 expression and its regulation by promoter 4G/5G polymorphism in clear cell renal cell carcinoma.

    Science.gov (United States)

    Choi, Jung-Woo; Lee, Ju-Han; Park, Hong Seok; Kim, Young-Sik

    2011-10-01

    To characterise patients with high plasminogen activator inhibitor-1 (PAI-1) expression as oral PAI-1 antagonists are currently in preclinical trials, and to determine whether the PAI-1 promoter 4G/5G polymorphism regulates PAI-1 expression in clear cell renal cell carcinoma (CCRCC). PAI-1 expression was examined by immunohistochemistry in 69 CCRCC specimens. In addition, the promoter 4G/5G polymorphism was investigated by both allele-specific PCR and direct DNA sequencing. PAI-1 was overexpressed in 25/69 (36.2%) patients with CCRCC. PAI-1 staining was intense in tumour cells with a high Fuhrman nuclear grade and in spindle-shaped tumour cells. PAI-1 expression was significantly associated with older age at diagnosis (p=0.027), high nuclear grade (p5G and 31.9% (22/69) 5G/5G. The homozygous 4G/4G or 5G/5G group showed a tendency for a high nuclear grade (p=0.05) but the 4G/5G polymorphism was not related to other prognostic parameters. PAI-1 expression was poorly correlated with its promoter 4G/5G polymorphism (Spearman ρ=0.088). CCRCC with high PAI-1 expression is characterised by older age, high nuclear grade, advanced stage, distant metastasis and/or shortened disease-free survival. PAI-1 expression is not affected by the promoter 4G/5G polymorphism.

  4. Interspecies systems biology uncovers metabolites affecting C. elegans gene expression and life history traits.

    Science.gov (United States)

    Watson, Emma; MacNeil, Lesley T; Ritter, Ashlyn D; Yilmaz, L Safak; Rosebrock, Adam P; Caudy, Amy A; Walhout, Albertha J M

    2014-02-13

    Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here, we used an interspecies systems biology approach with Caenorhabditis elegans and two of its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal's gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development, and reduces fertility but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid, preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Decoding NADPH oxidase 4 expression in human tumors

    Directory of Open Access Journals (Sweden)

    Jennifer L. Meitzler

    2017-10-01

    Full Text Available NADPH oxidase 4 (NOX4 is a redox active, membrane-associated protein that contributes to genomic instability, redox signaling, and radiation sensitivity in human cancers based on its capacity to generate H2O2 constitutively. Most studies of NOX4 in malignancy have focused on the evaluation of a small number of tumor cell lines and not on human tumor specimens themselves; furthermore, these studies have often employed immunological tools that have not been well characterized. To determine the prevalence of NOX4 expression across a broad range of solid tumors, we developed a novel monoclonal antibody that recognizes a specific extracellular region of the human NOX4 protein, and that does not cross-react with any of the other six members of the NOX gene family. Evaluation of 20 sets of epithelial tumors revealed, for the first time, high levels of NOX4 expression in carcinomas of the head and neck (15/19 patients, esophagus (12/18 patients, bladder (10/19 patients, ovary (6/17 patients, and prostate (7/19 patients, as well as malignant melanoma (7/15 patients when these tumors were compared to histologically-uninvolved specimens from the same organs. Detection of NOX4 protein upregulation by low levels of TGF-β1 demonstrated the sensitivity of this new probe; and immunofluorescence experiments found that high levels of endogenous NOX4 expression in ovarian cancer cells were only demonstrable associated with perinuclear membranes. These studies suggest that NOX4 expression is upregulated, compared to normal tissues, in a well-defined, and specific group of human carcinomas, and that its expression is localized on intracellular membranes in a fashion that could modulate oxidative DNA damage.

  6. Emodin suppresses migration and invasion through the modulation of CXCR4 expression in an orthotopic model of human hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Kanjoormana Aryan Manu

    Full Text Available Accumulating evidence(s indicate that CXCL12-CXCR4 signaling cascade plays an important role in the process of invasion and metastasis that accounts for more than 80% of deaths in hepatocellular carcinoma (HCC patients. Thus, identification of novel agents that can downregulate CXCR4 expression and its associated functions have a great potential in the treatment of metastatic HCC. In the present report, we investigated an anthraquinone derivative, emodin for its ability to affect CXCR4 expression as well as function in HCC cells. We observed that emodin downregulated the expression of CXCR4 in a dose-and time-dependent manner in HCC cells. Treatment with pharmacological proteasome and lysosomal inhibitors did not have substantial effect on emodin-induced decrease in CXCR4 expression. When investigated for the molecular mechanism(s, it was observed that the suppression of CXCR4 expression was due to downregulation of mRNA expression, inhibition of NF-κB activation, and abrogation of chromatin immunoprecipitation activity. Inhibition of CXCR4 expression by emodin further correlated with the suppression of CXCL12-induced migration and invasion in HCC cell lines. In addition, emodin treatment significantly suppressed metastasis to the lungs in an orthotopic HCC mice model and CXCR4 expression in tumor tissues. Overall, our results show that emodin exerts its anti-metastatic effect through the downregulation of CXCR4 expression and thus has the potential for the treatment of HCC.

  7. Do GnRH analogues directly affect human endometrial epithelial cell gene expression?

    KAUST Repository

    Zhang, Xiaomei

    2010-03-04

    We examined whether Gonadotrophin-releasing hormone (GnRH) analogues [leuprolide acetate (LA) and ganirelix acetate (GA)] modulate gene expression in Ishikawa cells used as surrogate for human endometrial epithelial cells in vitro. The specific aims were: (i) to study the modulatory effect of GnRH analogues by RT-PCR [in the absence and presence of E2 and P4, and cyclic adenosine monophos-phate (cAMP)] on mRNA expression of genes modulated during the window of implantation in GnRH analogues/rFSH-treated assisted reproductive technology cycles including OPTINEURIN (OPTN), CHROMATIN MODIFYING PROTEIN (CHMP1A), PROSAPOSIN (PSAP), IGFBP-5 and SORTING NEXIN 7 (SNX7), and (ii) to analyze the 5\\'-flanking regions of such genes for the presence of putative steroid-response elements [estrogen-response elements (EREs) and P4-response element (PREs)]. Ishikawa cells were cytokeratin+/vimentin2 and expressed ERa,ERb, PR and GnRH-R proteins. At 6 and 24 h, neither LA nor GA alone had an effect on gene expression. GnRH analogues alone or following E2 and/or P4 co-incubation for 24 h also had no effect on gene expression, but P4 significantly increased expression of CHMP1A.E2 + P4 treatment for 4 days, alone or followed by GA, had no effect, but E2 + P4 treatment followed by LA significantly decreased IGFBP-5 expression. The addition of 8-Br cAMP did not modify gene expression, with the exception of IGFBP-5 that was significantly increased. The GnRH analogues did not modify intracellular cAMP levels. We identified conserved EREs for OPN, CHMP1A, SNX7 and PSAP and PREs for SNX7. We conclude that GnRH analogues appear not to have major direct effects on gene expression of human endo-metrial epithelial cells in vitro. © The Author 2010. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

  8. Effects of extracellular modulation through hypoxia on the glucose metabolism of human breast cancer stem cells

    Science.gov (United States)

    Yustisia, I.; Jusman, S. W. A.; Wanandi, S. I.

    2017-08-01

    Cancer stem cells have been reported to maintain stemness under certain extracellular changes. This study aimed to analyze the effect of extracellular O2 level modulation on the glucose metabolism of human CD24-/CD44+ breast cancer stem cells (BCSCs). The primary BCSCs (CD24-/CD44+ cells) were cultured under hypoxia (1% O2) for 0.5, 4, 6, 24 and 48 hours. After each incubation period, HIF1α, GLUT1 and CA9 expressions, as well as glucose metabolism status, including glucose consumption, lactate production, O2 consumption and extracellular pH (pHe) were analyzed using qRT-PCR, colorimetry, fluorometry, and enzymatic reactions, respectively. Hypoxia caused an increase in HIF1α mRNA expressions and protein levels and shifted the metabolic states to anaerobic glycolysis, as demonstrated by increased glucose consumption and lactate production, as well as decreased O2 consumption and pHe. Furthermore, we demonstrated that GLUT1 and CA9 mRNA expressions simultaneously increased, in line with HIF1α expression. In conclusion, modulation of the extracellular environment of human BCSCs through hypoxia shifedt the metabolic state of BCSCs to anaerobic glycolysis, which might be associated with GLUT1 and CA9 expressions regulated by HIFlα transcription factor.

  9. Inactivation of Bmp4 from the Tbx1 Expression Domain Causes Abnormal Pharyngeal Arch Artery and Cardiac Outflow Tract Remodeling

    Science.gov (United States)

    Nie, Xuguang; Brown, Christopher B.; Wang, Qin; Jiao, Kai

    2011-01-01

    Maldevelopment of outflow tract and aortic arch arteries is among the most common forms of human congenital heart diseases. Both Bmp4 and Tbx1 are known to play critical roles during cardiovascular development. Expression of these two genes partially overlaps in pharyngeal arch areas in mouse embryos. In this study, we applied a conditional gene inactivation approach to test the hypothesis that Bmp4 expressed from the Tbx1 expression domain plays a critical role for normal development of outflow tract and pharyngeal arch arteries. We showed that inactivation of Bmp4 from Tbx1-expressing cells leads to the spectrum of deformities resembling the cardiovascular defects observed in human DiGeorge syndrome patients. Inactivation of Bmp4 from the Tbx1 expression domain did not cause patterning defects, but affected remodeling of outflow tract and pharyngeal arch arteries. Our further examination revealed that Bmp4 is required for normal recruitment/differentiation of smooth muscle cells surrounding the PAA4 and survival of outflow tract cushion mesenchymal cells. PMID:21123999

  10. Ezrin is down-regulated in diabetic kidney glomeruli and regulates actin reorganization and glucose uptake via GLUT1 in cultured podocytes.

    Science.gov (United States)

    Wasik, Anita A; Koskelainen, Susanna; Hyvönen, Mervi E; Musante, Luca; Lehtonen, Eero; Koskenniemi, Kerttu; Tienari, Jukka; Vaheri, Antti; Kerjaschki, Dontscho; Szalay, Csaba; Révész, Csaba; Varmanen, Pekka; Nyman, Tuula A; Hamar, Peter; Holthöfer, Harry; Lehtonen, Sanna

    2014-06-01

    Diabetic nephropathy is a complication of diabetes and a major cause of end-stage renal disease. To characterize the early pathophysiological mechanisms leading to glomerular podocyte injury in diabetic nephropathy, we performed quantitative proteomic profiling of glomeruli isolated from rats with streptozotocin-induced diabetes and controls. Fluorescence-based two-dimensional difference gel electrophoresis, coupled with mass spectrometry, identified 29 differentially expressed spots, including actin-binding protein ezrin and its interaction partner, NHERF2, which were down-regulated in the streptozotocin group. Knockdown of ezrin by siRNA in cultured podocytes increased glucose uptake compared with control siRNA-transfected cells, apparently by increasing translocation of glucose transporter GLUT1 to the plasma membrane. Knockdown of ezrin also induced actin remodeling under basal conditions, but reduced insulin-stimulated actin reorganization. Ezrin-dependent actin remodeling involved cofilin-1 that is essential for the turnover and reorganization of actin filaments. Phosphorylated, inactive cofilin-1 was up-regulated in diabetic glomeruli, suggesting altered actin dynamics. Furthermore, IHC analysis revealed reduced expression of ezrin in the podocytes of patients with diabetes. Our findings suggest that ezrin may play a role in the development of the renal complication in diabetes by regulating transport of glucose and organization of the actin cytoskeleton in podocytes. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  11. Expression of sall4 in taste buds of zebrafish.

    Science.gov (United States)

    Jackson, Robyn; Braubach, Oliver R; Bilkey, Jessica; Zhang, Jing; Akimenko, Marie-Andrée; Fine, Alan; Croll, Roger P; Jonz, Michael G

    2013-07-01

    We characterized the expression of sall4, a gene encoding a zinc finger transcription factor involved in the maintenance of embryonic stem cells, in taste buds of zebrafish (Danio rerio). Using an enhancer trap line (ET5), we detected enhanced green fluorescent protein (EGFP) in developing and adult transgenic zebrafish in regions containing taste buds: the lips, branchial arches, and the nasal and maxillary barbels. Localization of EGFP to taste cells of the branchial arches and lips was confirmed by co-immunolabeling with antibodies against calretinin and serotonin, and a zebrafish-derived neuronal marker (zn-12). Transgenic insertion of the ET construct into the zebrafish genome was evaluated and mapped to chromosome 23 in proximity (i.e. 23 kb) to the sall4 gene. In situ hybridization and expression analysis between 24 and 96 h post-fertilization (hpf) demonstrated that transgenic egfp expression in ET5 zebrafish was correlated with the spatial and temporal pattern of expression of sall4 in the wild-type. Expression was first observed in the central nervous system and branchial arches at 24 hpf. At 48 hpf, sall4 and egfp expression was observed in taste bud primordia surrounding the mouth and branchial arches. At 72 and 96 hpf, expression was detected in the upper and lower lips and branchial arches. Double fluorescence in situ hybridization at 3 and 10 dpf confirmed colocalization of sall4 and egfp in the lips and branchial arches. These studies reveal sall4 expression in chemosensory cells and implicate this transcription factor in the development and renewal of taste epithelia in zebrafish. Copyright © 2013 Wiley Periodicals, Inc.

  12. Perinatal exposure to diesel exhaust affects gene expression in mouse cerebrum

    Energy Technology Data Exchange (ETDEWEB)

    Tsukue, Naomi [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Noda, Chiba (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); Japan Automobile Research Institute, Health Effects Research Group, Energy and Environment Research Division, Tsukuba, Ibaraki (Japan); Watanabe, Manabu; Kumamoto, Takayuki; Takeda, Ken [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Noda, Chiba (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); Takano, Hirohisa [Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); National Institute for Environmental Studies, Pathophysiology Research Team, Tsukuba, Ibaraki (Japan)

    2009-11-15

    Many environmental toxins alter reproductive function and affect the central nervous system (CNS). Gonadal steroid hormones cause differentiation of neurons and affect brain function and behavior during the perinatal period, and the CNS is thought to be particularly susceptible to toxic insult during this period. It was, therefore, hypothesized that inhalation of diesel exhaust (DE) during the fetal or suckling period would disrupt the sexual differentiation of brain function in mice, and the effects of exposure to DE during the perinatal period on sexual differentiation related gene expression of the brain were investigated. In the fetal period exposure group, pregnant ICR mice were exposed to DE from 1.5 days post-coitum (dpc) until 16 dpc. In the neonatal period exposure group, dams and their offspring were exposed to DE from the day of birth [postnatal day (PND)-0] until PND-16. Then, the cerebrums of males and females at PND-2, -5, and -16 from both groups were analyzed for expression level of mRNA encoding stress-related proteins [cytochrome P450 1A1 (CYP1A1), heme oxygenase-1 (HO-1)] and steroid hormone receptors [estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta), androgen receptor (AR)]. Expression levels of ER alpha and ER beta mRNA were increased in the cerebrum of newborns in the DE exposure groups as well as mRNA for CYP1A1 and HO-1. Results indicate that perinatal exposure to DE during the critical period of sexual differentiation of the brain may affect endocrine function. (orig.)

  13. 2B4 expression on natural killer cells increases in HIV-1 infected patients followed prospectively during highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Ostrowski, S R; Ullum, H; Pedersen, Bente Klarlund

    2005-01-01

    Human immunodeficiency virus (HIV)-1 infection influences natural killer (NK) cell expression of inhibitory NK receptors and activating natural cytotoxicity receptors. It is unknown whether expression of the co-stimulatory NK cell receptor 2B4 (CD244) on NK cells and CD3+ CD8+ cells are affected ...

  14. Estudio de pacientes con aciduria glutárica tipo II, mediante la incubación de fibroblastos con ácidos palmítico y mirístico tritiados = Study of patients with type II glutaric aciduria by incubation of fibroblasts with tritiated palmitic and myristic acids

    Directory of Open Access Journals (Sweden)

    Osorio Orozco, José Henry

    2011-09-01

    Full Text Available Introducción: la aciduria glutárica tipo II, o deficiencia múltiple de acil-CoA deshidrogenasas, es un trastorno causado por deficiencia de la flavoproteína de transferencia de electrones, de su oxidorreductasa o de ambas; se trata de una enfermedad metabólica autosómica recesiva, caracterizada por acidosis, hipoglicemia, aciduria orgánica, olor a pies sudados y malformaciones en cerebro y riñones.Objetivo: analizar las tasas de oxidación de sustratos tritiados por fibroblastos de pacientes con aciduria glutárica tipo II.Materiales y métodos: se incubaron fibroblastos de dos pacientes con aciduria glutárica tipo II y de 20 controles en presencia de ácidos palmítico y mirístico tritiados.Resultados: se encontró muy deprimida (16%-18% la oxidación de los sustratos tritiados por los fibroblastos procedentes de pacientes con aciduria glutárica tipo II en comparación con los controles.Conclusión: la prueba estudiada permite la confirmación in vitro del diagnóstico de aciduria glutárica tipo II.

  15. Decreased astroglial monocarboxylate transporter 4 expression in temporal lobe epilepsy.

    Science.gov (United States)

    Liu, Bei; Niu, Le; Shen, Ming-Zhi; Gao, Lei; Wang, Chao; Li, Jie; Song, Li-Jia; Tao, Ye; Meng, Qiang; Yang, Qian-Li; Gao, Guo-Dong; Zhang, Hua

    2014-10-01

    Efflux of monocaroxylates like lactate, pyruvate, and ketone bodies from astrocytes through monocarboxylate transporter 4 (MCT4) supplies the local neuron population with metabolic intermediates to meet energy requirements under conditions of increased demand. Disruption of this astroglial-neuron metabolic coupling pathway may contribute to epileptogenesis. We measured MCT4 expression in temporal lobe epileptic foci excised from patients with intractable epilepsy and in rats injected with pilocarpine, an animal model of temporal lobe epilepsy (TLE). Cortical MCT4 expression levels were significantly lower in TLE patients compared with controls, due at least partially to MCT4 promoter methylation. Expression of MCT4 also decreased progressively in pilocarpine-treated rats from 12 h to 14 days post-administration. Underexpression of MCT4 in cultured astrocytes induced by a short hairpin RNA promoted apoptosis. Knockdown of astrocyte MCT4 also suppressed excitatory amino acid transporter 1 (EAAT1) expression. Reduced MCT4 and EAAT1 expression by astrocytes may lead to neuronal hyperexcitability and epileptogenesis in the temporal lobe by reducing the supply of metabolic intermediates and by allowing accumulation of extracellular glutamate.

  16. Elevated muscle TLR4 expression and metabolic endotoxemia in human aging.

    Science.gov (United States)

    Ghosh, Sangeeta; Lertwattanarak, Raweewan; Garduño, Jose de Jesus; Galeana, Joaquin Joya; Li, Jinqi; Zamarripa, Frank; Lancaster, Jack L; Mohan, Sumathy; Hussey, Sophie; Musi, Nicolas

    2015-02-01

    Aging is associated with alterations in glucose metabolism and sarcopenia that jointly contribute to a higher risk of developing type 2 diabetes. Because aging is considered as a state of low-grade inflammation, in this study we examined whether older, healthy (lean, community-dwelling) participants have altered signaling flux through toll-like receptor 4 (TLR4), a key mediator of innate and adaptive immune responses. We also examined whether a 4-month aerobic exercise program would have an anti-inflammatory effect by reducing TLR4 expression and signaling. At baseline, muscle TLR4, nuclear factor κB p50 and nuclear factor κB p65 protein content, and c-Jun N-terminal kinase phosphorylation were significantly elevated in older versus young participants. The plasma concentration of the TLR4 agonist lipopolysaccharide and its binding protein also were significantly elevated in older participants, indicative of metabolic endotoxemia, which is a recently described phenomenon of increased plasma endotoxin level in metabolic disease. These alterations in older participants were accompanied by decreased insulin sensitivity, quadriceps muscle volume, and muscle strength. The exercise training program increased insulin sensitivity, without affecting quadriceps muscle volume or strength. Muscle TLR4, nuclear factor κB, and c-Jun N-terminal kinase, and plasma lipopolysaccharide and lipopolysaccharide binding protein were not changed by exercise. In conclusion, insulin resistance and sarcopenia of aging are associated with increased TLR4 expression/signaling, which may be secondary to metabolic endotoxemia. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Increased expression of CYP4Z1 promotes tumor angiogenesis and growth in human breast cancer

    International Nuclear Information System (INIS)

    Yu, Wei; Chai, Hongyan; Li, Ying; Zhao, Haixia; Xie, Xianfei; Zheng, Hao; Wang, Chenlong; Wang, Xue; Yang, Guifang; Cai, Xiaojun; Falck, John R.; Yang, Jing

    2012-01-01

    Cytochrome P450 (CYP) 4Z1, a novel CYP4 family member, is over-expressed in human mammary carcinoma and associated with high-grade tumors and poor prognosis. However, the precise role of CYP4Z1 in tumor progression is unknown. Here, we demonstrate that CYP4Z1 overexpression promotes tumor angiogenesis and growth in breast cancer. Stable expression of CYP4Z1 in T47D and BT-474 human breast cancer cells significantly increased mRNA expression and production of vascular endothelial growth factor (VEGF)-A, and decreased mRNA levels and secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), without affecting cell proliferation and anchorage-independent cell growth in vitro. Notably, the conditioned medium from CYP4Z1-expressing cells enhanced proliferation, migration and tube formation of human umbilical vein endothelial cells, and promoted angiogenesis in the zebrafish embryo and chorioallantoic membrane of the chick embryo. In addition, there were lower levels of myristic acid and lauric acid, and higher contents of 20-hydroxyeicosatetraenoic acid (20-HETE) in CYP4Z1-expressing T47D cells compared with vector control. CYP4Z1 overexpression significantly increased tumor weight and microvessel density by 2.6-fold and 1.9-fold in human tumor xenograft models, respectively. Moreover, CYP4Z1 transfection increased the phosphorylation of ERK1/2 and PI3K/Akt, while PI3K or ERK inhibitors and siRNA silencing reversed CYP4Z1-mediated changes in VEGF-A and TIMP-2 expression. Conversely, HET0016, an inhibitor of the CYP4 family, potently inhibited the tumor-induced angiogenesis with associated changes in the intracellular levels of myristic acid, lauric acid and 20-HETE. Collectively, these data suggest that increased CYP4Z1 expression promotes tumor angiogenesis and growth in breast cancer partly via PI3K/Akt and ERK1/2 activation. -- Highlights: ► CYP4Z1 overexpression promotes human breast cancer growth and angiogenesis. ► The pro-angiogenic effects of CYP4Z1 have

  18. Increased expression of CYP4Z1 promotes tumor angiogenesis and growth in human breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Wei [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Chai, Hongyan [Center for Gene Diagnosis, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Li, Ying; Zhao, Haixia; Xie, Xianfei; Zheng, Hao; Wang, Chenlong; Wang, Xue [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Yang, Guifang [Department of Pathology, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Cai, Xiaojun [Department of Ophthalmology, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Falck, John R. [Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States); Yang, Jing, E-mail: yangjingliu@yahoo.com.cn [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

    2012-10-01

    Cytochrome P450 (CYP) 4Z1, a novel CYP4 family member, is over-expressed in human mammary carcinoma and associated with high-grade tumors and poor prognosis. However, the precise role of CYP4Z1 in tumor progression is unknown. Here, we demonstrate that CYP4Z1 overexpression promotes tumor angiogenesis and growth in breast cancer. Stable expression of CYP4Z1 in T47D and BT-474 human breast cancer cells significantly increased mRNA expression and production of vascular endothelial growth factor (VEGF)-A, and decreased mRNA levels and secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), without affecting cell proliferation and anchorage-independent cell growth in vitro. Notably, the conditioned medium from CYP4Z1-expressing cells enhanced proliferation, migration and tube formation of human umbilical vein endothelial cells, and promoted angiogenesis in the zebrafish embryo and chorioallantoic membrane of the chick embryo. In addition, there were lower levels of myristic acid and lauric acid, and higher contents of 20-hydroxyeicosatetraenoic acid (20-HETE) in CYP4Z1-expressing T47D cells compared with vector control. CYP4Z1 overexpression significantly increased tumor weight and microvessel density by 2.6-fold and 1.9-fold in human tumor xenograft models, respectively. Moreover, CYP4Z1 transfection increased the phosphorylation of ERK1/2 and PI3K/Akt, while PI3K or ERK inhibitors and siRNA silencing reversed CYP4Z1-mediated changes in VEGF-A and TIMP-2 expression. Conversely, HET0016, an inhibitor of the CYP4 family, potently inhibited the tumor-induced angiogenesis with associated changes in the intracellular levels of myristic acid, lauric acid and 20-HETE. Collectively, these data suggest that increased CYP4Z1 expression promotes tumor angiogenesis and growth in breast cancer partly via PI3K/Akt and ERK1/2 activation. -- Highlights: ► CYP4Z1 overexpression promotes human breast cancer growth and angiogenesis. ► The pro-angiogenic effects of CYP4Z1 have

  19. Low-Magnitude High-Frequency Vibration Accelerated the Foot Wound Healing of n5-streptozotocin-induced Diabetic Rats by Enhancing Glucose Transporter 4 and Blood Microcirculation.

    Science.gov (United States)

    Yu, Caroline Oi-Ling; Leung, Kwok-Sui; Jiang, Jonney Lei; Wang, Tina Bai-Yan; Chow, Simon Kwoon-Ho; Cheung, Wing-Hoi

    2017-09-14

    Delayed wound healing is a Type 2 diabetes mellitus (DM) complication caused by hyperglycemia, systemic inflammation, and decreased blood microcirculation. Skeletal muscles are also affected by hyperglycemia, resulting in reduced blood flow and glucose uptake. Low Magnitude High Frequency Vibration (LMHFV) has been proven to be beneficial to muscle contractility and blood microcirculation. We hypothesized that LMHFV could accelerate the wound healing of n5-streptozotocin (n5-STZ)-induced DM rats by enhancing muscle activity and blood microcirculation. This study investigated the effects of LMHFV in an open foot wound created on the footpad of n5-STZ-induced DM rats (DM_V), compared with no-treatment DM (DM), non-DM vibration (Ctrl_V) and non-DM control rats (Ctrl) on Days 1, 4, 8 and 13. Results showed that the foot wounds of DM_V and Ctrl_V rats were significantly reduced in size compared to DM and Ctrl rats, respectively, at Day 13. The blood glucose level of DM_V rats was significantly reduced, while the glucose transporter 4 (GLUT4) expression and blood microcirculation of DM_V rats were significantly enhanced in comparison to those of DM rats. In conclusion, LMHFV can accelerate the foot wound healing process of n5-STZ rats.

  20. Neuropilin-2 expression in breast cancer: correlation with lymph node metastasis, poor prognosis, and regulation of CXCR4 expression

    International Nuclear Information System (INIS)

    Yasuoka, Hironao; Kodama, Rieko; Tsujimoto, Masahiko; Yoshidome, Katsuhide; Akamatsu, Hiroki; Nakahara, Masaaki; Inagaki, Michiya; Sanke, Tokio; Nakamura, Yasushi

    2009-01-01

    Neuropilin-2 (Nrp2) is a receptor for vascular endothelial growth factor-C (VEGF-C), which is a well-known lymphangiogenic factor and plays an important role in lymph node metastasis of various human cancers, including breast cancer. Recently, Nrp2 was shown to play a role in cancer by promoting tumor cell metastasis. CXC chemokine receptor 4 (CXCR4) also promotes tumor metastasis. In the previous studies, we demonstrated that VEGF-C and cytoplasmic CXCR4 expressions were correlated with poorer patient prognosis (BMC Cancer 2008,8:340; Breast Cancer Res Treat 2005, 91:125–132). The relationship between Nrp2 expression and lymph node metastasis, VEGF-C expression, CXCR4 expression, and other established clinicopathological variables (these data were cited in our previous papers), including prognosis, was analyzed in human breast cancer. Effects of neutralizing anti-Nrp2 antibody on CXCR4 expression and chemotaxis were assessed in MDA-MB-231 breast cancer cells. Nrp2 expression was observed in 53.1% (60 of 113) of the invasive breast carcinomas. Nrp2 expression was significantly correlated with lymph node metastasis, VEGF-C expression, and cytoplasmic CXCR4 expression. Survival curves determined by the Kaplan-Meier method showed that Nrp2 expression was associated with reduced overall survival. In multivariate analysis, Nrp2 expression emerged as a significant independent predictor for overall survival. Neutralizing anti-Nrp2 antibody blocks cytoplasmic CXCR4 expression and CXCR4-induced migration in MDA-MB-231 cells. Nrp2 expression was correlated with lymph node metastasis, VEGF-C expression, and cytoplasmic CXCR4 expression. Nrp2 expression may serve as a significant prognostic factor for long-term survival in breast cancer. Our data also showed a role for Nrp2 in regulating cytoplasmic CXCR4 expression in vitro

  1. Significance of TLR4/MyD88 expression in breast cancer

    Science.gov (United States)

    Chen, Xiangjin; Zhao, Feng; Zhang, Huihao; Zhu, Youzhi; Wu, Kunlin; Tan, Guozheng

    2015-01-01

    Objective: To investigate the expression of TLR4/MyD88 in breast cancer, and explore the relationship between their expression and breast cancer tumor growth and invasion. Methods: We examined the protein expression of TLR4 and MyD88 in 60 cases of histologically confirmed breast cancer. The relationship of their protein expressions with clinical features including age at diagnosis, tumor size and stage, lymph node metastasis and distant metastasis were analyzed. Results: The IHC results showed that TLR4 and MyD88 were expressed in 63.3% (38/60) and 58.3% (35/60) of malignant breast tumors respectively. TLR4 expression in breast cancer were significantly higher than in fibroadenoma (n = 4, 20.0%) and adjacent normal tissues (n = 2, 10.0%) (P fibroadenoma (n = 4, 20.0%) and adjacent normal tissue (n = 3, 15.0%) (P fibroadenoma and adjacent normal tissues (P < 0.05). The protein expressions of TLR4 and MyD88 were also significantly associated with poor clinical features (P < 0.05). Conclusion: TLR4 and MyD88 expression might be associated with breast cancer growth and regional and distant metastases. PMID:26261595

  2. In situ TLR2 and TLR4 expression in a murine model of mycetoma caused by Nocardia brasiliensis.

    Science.gov (United States)

    Millán-Chiu, Blanca Edith; Hernández-Hernández, Francisca; Pérez-Torres, Armando; Méndez-Tovar, Luis Javier; López-Martínez, Rubén

    2011-04-01

    Actinomycetoma caused by Nocardia brasiliensis is a common disease in tropical regions. This ailment is characterized by a localized chronic inflammation that mainly affects the lower limbs. Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns, inducing the production of proinflammatory mediators. The role of TLRs in the immune response against N. brasiliensis is unknown. The aim of this work was to locate and quantify in a murine model the expression of TLR2 and TLR4 in the infection site using reverse transcription-PCR and immunohistochemistry. The results showed that TLR2 expression increased in the infected tissue, whereas TLR4 expression decreased. The presence of TLR2 and TLR4 was demonstrated in different cell populations throughout the chronic infectious process. In the early stages of this process, TLR2 was expressed in neutrophils and macrophages in direct contact with the inoculum, whereas TLR4 was observed in mast cells. In the advanced stages of the infection, TLR2 was expressed in foam cells and fibroblasts and was likely associated with bacterial containment, while TLR4 was downregulated, probably resulting in an imbalance between the host immune response and the bacterial load that favoured chronic disease. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Analysis of IgG4-positive clones in affected organs of IgG4-related disease.

    Science.gov (United States)

    Kakuchi, Yasushi; Yamada, Kazunori; Ito, Kiyoaki; Hara, Satoshi; Fujii, Hiroshi; Yamagishi, Masakazu; Kawano, Mitsuhiro

    2016-11-01

    We investigated class switch reaction (CSR) in affected organs and evaluated whether the same or genetically related clones exist in IgG4-RD. We studied three patients with IgG4-RD. Total cellular RNA was extracted from salivary glands and peripheral blood and lung tissue. Activation-induced cytidine deaminase (AID) and immunoglobulin heavy chain third complementarity determining region (IgVH-CDR3) of IgM and IgG4 were detected by reverse transcription polymerase chain reaction (RT-PCR). We analyzed the clonal relationship of infiltrating IgG4-positive cells, as compared with IgM. We determined the existence of common clones among organs and patients. AID was expressed in salivary glands of all patients and lung tissue in one. Closely related IgVH-CDR3 sequences in infiltrating IgG4-positive cells were detected in salivary glands and lung tissue. Identical IgVH-CDR3 sequence between IgM and IgG4 in salivary glands was detected in one patient, indicating CSR in salivary glands. Identical IgVH-CDR3 sequences of IgG4-positive cells were detected between salivary glands and peripheral blood in two patients. Four identical sequences of IgVH-CDR3 existed between patients. Interestingly, one of the four sequences was detected in all patients. Our results demonstrate the existence of common antigen(s) shared by patients with IgG4-RD.

  4. The NDE1 genomic locus can affect treatment of psychiatric illness through gene expression changes related to microRNA-484.

    Science.gov (United States)

    Bradshaw, Nicholas J; Ukkola-Vuoti, Liisa; Pankakoski, Maiju; Zheutlin, Amanda B; Ortega-Alonso, Alfredo; Torniainen-Holm, Minna; Sinha, Vishal; Therman, Sebastian; Paunio, Tiina; Suvisaari, Jaana; Lönnqvist, Jouko; Cannon, Tyrone D; Haukka, Jari; Hennah, William

    2017-11-01

    Genetic studies of familial schizophrenia in Finland have observed significant associations with a group of biologically related genes, DISC1 , NDE1 , NDEL1 , PDE4B and PDE4D , the 'DISC1 network'. Here, we use gene expression and psychoactive medication use data to study their biological consequences and potential treatment implications. Gene expression levels were determined in 64 individuals from 18 families, while prescription medication information has been collected over a 10-year period for 931 affected individuals. We demonstrate that the NDE1 SNP rs2242549 associates with significant changes in gene expression for 2908 probes (2542 genes), of which 794 probes (719 genes) were replicable. A significant number of the genes altered were predicted targets of microRNA-484 ( p = 3.0 × 10 -8 ), located on a non-coding exon of NDE1 Variants within the NDE1 locus also displayed significant genotype by gender interaction to early cessation of psychoactive medications metabolized by CYP2C19. Furthermore, we demonstrate that miR-484 can affect the expression of CYP2C19 in a cell culture system. Thus, variation at the NDE1 locus may alter risk of mental illness, in part through modification of miR-484, and such modification alters treatment response to specific psychoactive medications, leading to the potential for use of this locus in targeting treatment. © 2017 The Authors.

  5. SIK2 regulates CRTCs, HDAC4 and glucose uptake in adipocytes

    DEFF Research Database (Denmark)

    Henriksson, Emma; Säll, Johanna; Gormand, Amélie

    2015-01-01

    regulation in human adipocytes, strengthening the physiological relevance of our findings. Collectively, we demonstrate that SIK2 acts directly on CRTC2, CRTC3 and HDAC4, and that cAMP/PKA reduces the interaction of SIK2 with CRTCs and PP2A. Downstream, SIK2 promotes GLUT4 levels and glucose uptake...

  6. High sugar intake and development of skeletal muscle insulin resistance and inflammation in mice: a protective role for PPAR- δ agonism.

    Science.gov (United States)

    Benetti, Elisa; Mastrocola, Raffaella; Rogazzo, Mara; Chiazza, Fausto; Aragno, Manuela; Fantozzi, Roberto; Collino, Massimo; Minetto, Marco A

    2013-01-01

    Peroxisome Proliferator Activated Receptor (PPAR)- δ agonists may serve for treating metabolic diseases. However, the effects of PPAR- δ agonism within the skeletal muscle, which plays a key role in whole-body glucose metabolism, remain unclear. This study aimed to investigate the signaling pathways activated in the gastrocnemius muscle by chronic administration of the selective PPAR- δ agonist, GW0742 (1 mg/kg/day for 16 weeks), in male C57Bl6/J mice treated for 30 weeks with high-fructose corn syrup (HFCS), the major sweetener in foods and soft-drinks (15% wt/vol in drinking water). Mice fed with the HFCS diet exhibited hyperlipidemia, hyperinsulinemia, hyperleptinemia, and hypoadiponectinemia. In the gastrocnemius muscle, HFCS impaired insulin and AMP-activated protein kinase signaling pathways and reduced GLUT-4 and GLUT-5 expression and membrane translocation. GW0742 administration induced PPAR- δ upregulation and improvement in glucose and lipid metabolism. Diet-induced activation of nuclear factor-κB and expression of inducible-nitric-oxide-synthase and intercellular-adhesion-molecule-1 were attenuated by drug treatment. These effects were accompanied by reduction in the serum concentration of interleukin-6 and increase in muscular expression of fibroblast growth factor-21. Overall, here we show that PPAR- δ activation protects the skeletal muscle against the metabolic abnormalities caused by chronic HFCS exposure by affecting multiple levels of the insulin and inflammatory cascades.

  7. Effect of high sugar intake on glucose transporter and weight regulating hormones in mice and humans.

    Directory of Open Access Journals (Sweden)

    Yvonne Ritze

    Full Text Available OBJECTIVE: Sugar consumption has increased dramatically over the last decades in Western societies. Especially the intake of sugar-sweetened beverages seems to be a major risk for the development of obesity. Thus, we compared liquid versus solid high-sugar diets with regard to dietary intake, intestinal uptake and metabolic parameters in mice and partly in humans. METHODS: Five iso-caloric diets, enriched with liquid (in water 30% vol/vol or solid (in diet 65% g/g fructose or sucrose or a control diet were fed for eight weeks to C57bl/6 mice. Sugar, liquid and caloric intake, small intestinal sugar transporters (GLUT2/5 and weight regulating hormone mRNA expression, as well as hepatic fat accumulation were measured. In obese versus lean humans that underwent either bariatric surgery or small bowel resection, we analyzed small intestinal GLUT2, GLUT5, and cholecystokinin expression. RESULTS: In mice, the liquid high-sucrose diet caused an enhancement of total caloric intake compared to the solid high-sucrose diet and the control diet. In addition, the liquid high-sucrose diet increased expression of GLUT2, GLUT5, and cholecystokinin expression in the ileum (P<0.001. Enhanced liver triglyceride accumulation was observed in mice being fed the liquid high-sucrose or -fructose, and the solid high-sucrose diet compared to controls. In obese, GLUT2 and GLUT5 mRNA expression was enhanced in comparison to lean individuals. CONCLUSIONS: We show that the form of sugar intake (liquid versus solid is presumably more important than the type of sugar, with regard to feeding behavior, intestinal sugar uptake and liver fat accumulation in mice. Interestingly, in obese individuals, an intestinal sugar transporter modulation also occurred when compared to lean individuals.

  8. Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.

    Science.gov (United States)

    Lu, Yun-Yueh; Franz, Bettina; Truttmann, Matthias C; Riess, Tanja; Gay-Fraret, Jérémie; Faustmann, Marco; Kempf, Volkhard A J; Dehio, Christoph

    2013-05-01

    The Gram-negative, zoonotic pathogen Bartonella henselae is the aetiological agent of cat scratch disease, bacillary angiomatosis and peliosis hepatis in humans. Two pathogenicity factors of B. henselae - each displaying multiple functions in host cell interaction - have been characterized in greater detail: the trimeric autotransporter Bartonella adhesin A (BadA) and the type IV secretion system VirB/D4 (VirB/D4 T4SS). BadA mediates, e.g. binding to fibronectin (Fn), adherence to endothelial cells (ECs) and secretion of vascular endothelial growth factor (VEGF). VirB/D4 translocates several Bartonella effector proteins (Beps) into the cytoplasm of infected ECs, resulting, e.g. in uptake of bacterial aggregates via the invasome structure, inhibition of apoptosis and activation of a proangiogenic phenotype. Despite this knowledge of the individual activities of BadA or VirB/D4 it is unknown whether these major virulence factors affect each other in their specific activities. In this study, expression and function of BadA and VirB/D4 were analysed in a variety of clinical B. henselae isolates. Data revealed that most isolates have lost expression of either BadA or VirB/D4 during in vitro passages. However, the phenotypic effects of coexpression of both virulence factors was studied in one clinical isolate that was found to stably coexpress BadA and VirB/D4, as well as by ectopic expression of BadA in a strain expressing VirB/D4 but not BadA. BadA, which forms a dense layer on the bacterial surface, negatively affected VirB/D4-dependent Bep translocation and invasome formation by likely preventing close contact between the bacterial cell envelope and the host cell membrane. In contrast, BadA-dependent Fn binding, adhesion to ECs and VEGF secretion were not affected by a functional VirB/D4 T4SS. The obtained data imply that the essential virulence factors BadA and VirB/D4 are likely differentially expressed during different stages of the infection cycle of

  9. High-fat diet with stress impaired islets' insulin secretion by reducing plasma estradiol and pancreatic GLUT2 protein levels in rats' proestrus phase.

    Science.gov (United States)

    Salimi, M; Zardooz, H; Khodagholi, F; Rostamkhani, F; Shaerzadeh, F

    2016-10-01

    This study was conducted to determine whether two estrus phases (proestrus and diestrus) in female rats may influence the metabolic response to a high-fat diet and/or stress, focusing on pancreatic insulin secretion and content. Animals were divided into high-fat and normal diet groups, then each group was subdivided into stress and non-stress groups, and finally, each one of these was divided into proestrus and diestrus subgroups. At the end of high-fat diet treatment, foot-shock stress was applied to the animals. Then, blood samples were taken to measure plasma factors. Finally, the pancreas was removed for determination of glucose transporter 2 (GLUT2) protein levels and assessment of insulin content and secretion of the isolated islets. In the normal and high-fat diet groups, stress increased plasma corticosterone concentration in both phases. In both study phases, high-fat diet consumption decreased estradiol and increased leptin plasma levels. In the high-fat diet group in response to high glucose concentration, a reduction in insulin secretion was observed in the proestrus phase compared with the same phase in the normal diet group in the presence and absence of stress. Also, high-fat diet decreased the insulin content of islets in the proestrus phase compared with the normal diet. High-fat diet and/or stress caused a reduction in islet GLUT2 protein levels in both phases. In conclusion, it seems possible that high-fat diet alone or combined with foot-shock, predispose female rats to impaired insulin secretion, at least in part, by interfering with estradiol levels in the proestrus phase and decreasing pancreatic GLUT2 protein levels.

  10. EGCG evokes Nrf2 nuclear translocation and dampens PTP1B expression to ameliorate metabolic misalignment under insulin resistance condition.

    Science.gov (United States)

    Mi, Yashi; Zhang, Wentong; Tian, Haoyu; Li, Runnan; Huang, Shuxian; Li, Xingyu; Qi, Guoyuan; Liu, Xuebo

    2018-03-01

    As a major nutraceutical component of green tea (-)-epigallocatechin-3-gallate (EGCG) has attracted interest from scientists due to its well-documented antioxidant and antiobesity bioactivities. In the current study, we aimed to investigate the protective effect of EGCG on metabolic misalignment and in balancing the redox status in mice liver and HepG2 cells under insulin resistance condition. Our results indicated that EGCG accelerates the glucose uptake and evokes IRS-1/Akt/GLUT2 signaling pathway via dampening the expression of protein tyrosine phosphatase 1B (PTP1B). Consistently, ectopic expression of PTP1B by Ad-PTP1B substantially impaired EGCG-elicited IRS-1/Akt/GLUT2 signaling pathway. Moreover, EGCG co-treatment stimulated nuclear translocation of Nrf2 by provoking P13K/AKT signaling pathway and thus modulated the downstream expressions of antioxidant enzymes such as HO-1 and NQO-1 in HepG2 cells. Furthermore, knockdown Nrf2 by small interfering RNA (siRNA) notably enhanced the expression of PTP1B and blunt EGCG-stimulated glucose uptake. Consistent with these results, in vivo study revealed that EGCG supplement significantly ameliorated high-fat and high-fructose diet (HFFD)-triggered insulin resistance and oxidative stress by up-regulating the IRS-1/AKT and Keap1/Nrf2 transcriptional pathways. Administration of an appropriate chemopreventive agent, such as EGCG, could potentially serve as an additional therapeutic intervention in the arsenal against obesity.

  11. Increased Expression of the Na,K-ATPase alpha4 Isoform Enhances Sperm Motility in Transgenic Mice1

    Science.gov (United States)

    Jimenez, Tamara; Sanchez, Gladis; McDermott, Jeffrey P.; Nguyen, Anh-Nguyet; Kumar, T. Rajendra; Blanco, Gustavo

    2010-01-01

    The Na,K-ATPase alpha4 (ATP1A4) isoform is specifically expressed in male germ cells and is highly prevalent in spermatozoa. Although selective inhibition of alpha4 activity with ouabain has been shown to affect sperm motility, a more direct analysis of the role of this isoform in sperm movement has not yet been demonstrated. To establish this, we engineered transgenic mice that express the rat alpha4 isoform fused to green fluorescent protein in male germ cells, under the control of the mouse protamine 1 promoter. We showed that the rat Atp1a4 transgene is expressed in mouse spermatozoa and that it is localized to the sperm flagellum. In agreement with increased expression of the alpha4 isoform, sperm from transgenic mice displayed higher alpha4-specific Na,K-ATPase activity and binding of fluorescently labeled ouabain than wild-type mice. In contrast, expression and activity of ATP1A1 (alpha1), the other Na,K-ATPase alpha isoform present in sperm, remained unchanged. Similar to wild-type mice, mice expressing the alpha4 transgene exhibited normal testis and sperm morphology and no differences in fertility. However, compared to wild-type mice, sperm from transgenic mice displayed plasma membrane hyperpolarization and higher total and progressive motility. Other parameters of motility also increased, including straight-line, curvilinear, and average path velocities and amplitude of lateral head displacement. In addition, sperm from the transgenic mice showed enhanced sperm hyperactive motility, but no changes in progesterone-induced acrosome reaction. Altogether, these results provide new genetic evidence for the role of the ATP1A4 isoform in sperm motility, under both noncapacitating and capacitating conditions. PMID:20826726

  12. Endothelial glutathione-S-transferase A4-4 protects against oxidative stress and modulates iNOS expression through NF-κB translocation

    International Nuclear Information System (INIS)

    Yang Yongzhen; Yang Yusong; Xu Ya; Lick, Scott D.; Awasthi, Yogesh C.; Boor, Paul J.

    2008-01-01

    Our recent work in endothelial cells and human atherosclerotic plaque showed that overexpression of glutathione-S-tranferases (GSTs) in endothelium protects against oxidative damage from aldehydes such as 4-HNE. Nuclear factor (NF)-κB plays a crucial role during inflammation and immune responses by regulating the expression of inducible genes such as inducible nitric oxide synthase (iNOS). 4-HNE induces apoptosis and affects NF-κB mediated gene expression, but conflicting results on 4-HNE's effect on NF-κB have been reported. We compared the effect of 4-HNE on iNOS and the NF-κB pathway in control mouse pancreatic islet endothelial (MS1) cells and those transfected with mGSTA4, a α-class GST with highest activity toward 4-HNE. When treated with 4-HNE, mGSTA4-transfected cells showed significant upregulation of iNOS and nitric oxide (NO) through (NF)-κB (p65) translocation in comparison with wild-type or vector-transfected cells. Immunohistochemical studies of early human plaques showed lower 4-HNE content and upregulation of iNOS, which we take to indicate that GSTA4-4 induction acts as an enzymatic defense against high levels of 4-HNE, since 4-HNE accumulated in more advanced plaques, when detoxification and exocytotic mechanisms are likely to be overwhelmed. These studies suggest that GSTA4-4 may play an important defensive role against atherogenesis through detoxification of 4-HNE and upregulation of iNOS

  13. Long-Term Effect of GPi-DBS in a Patient With Generalized Dystonia Due to GLUT1 Deficiency Syndrome

    Directory of Open Access Journals (Sweden)

    Idil Hanci

    2018-05-01

    Full Text Available Treatment outcomes from pallidal deep brain stimulation are highly heterogeneous reflecting the phenotypic and etiologic spectrum of dystonia. Treatment stratification to neurostimulation therapy primarily relies on the phenotypic motor presentation; however, etiology including genetic factors are increasingly recognized as modifiers of treatment outcomes. Here, we describe a 53 year-old female patient with a progressive generalized dystonia since age 25. The patient underwent deep brain stimulation of the globus pallidus internus (GPi-DBS at age 44. Since the clinical phenotype included mobile choreo-dystonic features, we expected favorable therapeutic outcome from GPi-DBS. Although mobile dystonia components were slightly improved in the long-term outcome from GPi-DBS the overall therapeutic response 9 years from implantation was limited when comparing “stimulation off” and “stimulation on” despite of proper electrode localization and sufficient stimulation programming. In order to further understand the reason for this limited motor symptom response, we aimed to clarify the etiology of generalized dystonia in this patient. Genetic testing identified a novel heterozygous pathogenic SLC2A1 mutation as cause of glucose transporter type 1 deficiency syndrome (GLUT1-DS. This case report presents the first outcome of GPi-DBS in a patient with GLUT1-DS, and suggests that genotype relations may increasingly complement phenotype-based therapy stratification of GPi-DBS in dystonia.

  14. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    International Nuclear Information System (INIS)

    Si, Lina; Shi, Jin; Gao, Wenqun; Zheng, Min; Liu, Lingjuan; Zhu, Jing; Tian, Jie

    2014-01-01

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  15. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Si, Lina; Shi, Jin; Gao, Wenqun [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Zheng, Min [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Liu, Lingjuan; Zhu, Jing [Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Tian, Jie, E-mail: jietian@cqmu.edu.cn [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China)

    2014-07-18

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  16. Molecular Cloning, Characterization, and Expression Analysis of a Prolyl 4-Hydroxylase from the Marine Sponge Chondrosia reniformis.

    Science.gov (United States)

    Pozzolini, Marina; Scarfì, Sonia; Mussino, Francesca; Ferrando, Sara; Gallus, Lorenzo; Giovine, Marco

    2015-08-01

    Prolyl 4-hydroxylase (P4H) catalyzes the hydroxylation of proline residues in collagen. P4H has two functional subunits, α and β. Here, we report the cDNA cloning, characterization, and expression analysis of the α and β subunits of the P4H derived from the marine sponge Chondrosia reniformis. The amino acid sequence of the α subunit is 533 residues long with an M r of 59.14 kDa, while the β subunit counts 526 residues with an M r of 58.75 kDa. Phylogenetic analyses showed that αP4H and βP4H are more related to the mammalian sequences than to known invertebrate P4Hs. Western blot analysis of sponge lysate protein cross-linking revealed a band of 240 kDa corresponding to an α2β2 tetramer structure. This result suggests that P4H from marine sponges shares the same quaternary structure with vertebrate homologous enzymes. Gene expression analyses showed that αP4H transcript is higher in the choanosome than in the ectosome, while the study of factors affecting its expression in sponge fragmorphs revealed that soluble silicates had no effect on the αP4H levels, whereas ascorbic acid strongly upregulated the αP4H mRNA. Finally, treatment with two different tumor necrosis factor (TNF)-alpha inhibitors determined a significant downregulation of αP4H gene expression in fragmorphs demonstrating, for the first time in Porifera, a positive involvement of TNF in sponge matrix biosynthesis. The molecular characterization of P4H genes involved in collagen hydroxylation, including the mechanisms that regulate their expression, is a key step for future recombinant sponge collagen production and may be pivotal to understand pathological mechanisms related to extracellular matrix deposition in higher organisms.

  17. The influence of a working memory task on affective perception of facial expressions.

    Directory of Open Access Journals (Sweden)

    Seung-Lark Lim

    Full Text Available In a dual-task paradigm, participants performed a spatial location working memory task and a forced two-choice perceptual decision task (neutral vs. fearful with gradually morphed emotional faces (neutral ∼ fearful. Task-irrelevant word distractors (negative, neutral, and control were experimentally manipulated during spatial working memory encoding. We hypothesized that, if affective perception is influenced by concurrent cognitive load using a working memory task, task-irrelevant emotional distractors would bias subsequent perceptual decision-making on ambiguous facial expression. We found that when either neutral or negative emotional words were presented as task-irrelevant working-memory distractors, participants more frequently reported fearful face perception - but only at the higher emotional intensity levels of morphed faces. Also, the affective perception bias due to negative emotional distractors correlated with a decrease in working memory performance. Taken together, our findings suggest that concurrent working memory load by task-irrelevant distractors has an impact on affective perception of facial expressions.

  18. IFNL4 affects clearance of hepatitis C virus

    Science.gov (United States)

    Scientists have discovered a new human interferon gene, Interferon Lambda 4 (IFNL4), that affects clearance of the hepatitis C virus. They also identified an inherited genetic variant within IFNL4 that predicts how people respond to treatment for hepatit

  19. Hypoxia induced expression of endogenous markers in vitro is highly influenced by pH

    International Nuclear Information System (INIS)

    Sorensen, Brita Singers; Alsner, Jan; Overgaard, Jens; Horsman, Michael R.

    2007-01-01

    Background: Genes such as carbonic anhydrase IX (Ca9), glucose transporter 1 (Glut1), lactate dehydrogenase A (LDH-A), osteopontin (OPN) and lysyl oxidase (LOX) have been suggested as hypoxic markers, but inconsistent results suggest that factors other than oxygen influence their expression. The current study is a detailed investigation using a range of pH values from 6.3 to 7.5 in two human cell lines to establish the pH dependency of hypoxia induced gene expression. Methods: Human tumour cell lines (uterine cervix squamous cell carcinoma (SiHa) and pharyngeal squamous cell carcinoma [FaDu DD ]) were used. Hypoxia was induced by gassing cells in airtight chambers with various oxygen concentrations (21%, 1%, 0.1%, 0.01% and 0%) for up to 24 h. The media were titrated to a range of pH values (7.5, 7.0, 6.7, 6.5 and 6.3). Gene expression was determined by real-time PCR. Results: In both SiHa and FaDu DD cells Ca9 and LOX reached the highest level of expression at 1% oxygen. In FaDu DD cells, a pH of 6.5 had a medium suppression effect on the hypoxia induced expression of Ca9. pH 6.3 resulted in severe suppression of expression for Ca9 and LOX in both SiHa and FaDu DD . Glut1 and LDH-A had a similar expression pattern to each other, with a maximum expression at 0.01% oxygen, in both cell lines. For these genes pH 6.5 and 6.3 changed the expression pattern in SiHa cells. OPN was up regulated at low oxygen in SiHa cells, but was not induced by hypoxia in FaDu DD cells. Conclusion: As tumour hypoxia occurs in a deprived microenvironment, other environmental factors, for example low pH, might interact with the effect of low oxygen concentration on gene expression. This study shows that pH in two cell lines has a profound influence on the oxygen dependent induction of certain endogenous hypoxic markers

  20. Seizure control and acceptance of the ketogenic diet in GLUT1 deficiency syndrome: a 2- to 5-year follow-up of 15 children enrolled prospectively.

    NARCIS (Netherlands)

    Klepper, J.; Scheffer, H.; Leiendecker, B.; Gertsen, E.; Binder, S.; Leferink, M.; Hertzberg, C.; Nake, A.; Voit, T.; Willemsen, M.A.A.P.

    2005-01-01

    BACKGROUND: GLUT1 deficiency syndrome is caused by impaired glucose transport into the brain resulting in an epileptic encephalopathy, developmental delay, and a complex motor disorder. A ketogenic diet provides an alternative fuel to the brain and effectively restores brain energy metabolism.

  1. Prolonged endoplasmic reticulum stress alters placental morphology and causes low birth weight

    International Nuclear Information System (INIS)

    Kawakami, Takashige; Yoshimi, Masaki; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

    2014-01-01

    The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 μg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 μg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 μg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight. - Highlights: • Maternal exposure to excessive ER stress induced preterm birth and IUGR. • Prolonged excessive ER stress altered the formation of the placental labyrinth. • ER stress decreased GLUT1 mRNA expression in the placenta, but increased GLUT3. • ER stress-induced IUGR causes decreased glycogen and altered glucose transport

  2. Prolonged endoplasmic reticulum stress alters placental morphology and causes low birth weight

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Takashige, E-mail: tkawakami@ph.bunri-u.ac.jp; Yoshimi, Masaki; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

    2014-03-01

    The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 μg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 μg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 μg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight. - Highlights: • Maternal exposure to excessive ER stress induced preterm birth and IUGR. • Prolonged excessive ER stress altered the formation of the placental labyrinth. • ER stress decreased GLUT1 mRNA expression in the placenta, but increased GLUT3. • ER stress-induced IUGR causes decreased glycogen and altered glucose transport.

  3. Decreased serum glucose and glycosylated hemoglobin levels in patients with Chuvash polycythemia: a role for HIF in glucose metabolism

    Science.gov (United States)

    McClain, Donald A.; Abuelgasim, Khadega A.; Nouraie, Mehdi; Salomon-Andonie, Juan; Niu, Xiaomei; Miasnikova, Galina; Polyakova, Lydia A.; Sergueeva, Adelina; Okhotin, Daniel J.; Cherqaoui, Rabia; Okhotin, David; Cox, James E.; Swierczek, Sabina; Song, Jihyun; Simon, M.Celeste; Huang, Jingyu; Simcox, Judith A.; Yoon, Donghoon; Prchal, Josef T.; Gordeuk, Victor R.

    2012-01-01

    In Chuvash polycythemia, a homozygous 598C>T mutation in the von Hippel-Lindau gene (VHL) leads to an R200W substitution in VHL protein, impaired degradation of α-subunits of hypoxia inducible factor (HIF)-1 and HIF-2, and augmented hypoxic responses during normoxia. Chronic hypoxia of high altitude is associated with decreased serum glucose and insulin concentrations. Other investigators reported that HIF-1 promotes cellular glucose uptake by increased expression of GLUT1 and increased glycolysis by increased expression of enzymes such as PDK. On the other hand, inactivation of Vhl in murine liver leads to hypoglycemia associated with a HIF-2-related decrease in the expression of the gluconeogenic enzymes genes Pepck, G6pc, and Glut2. We therefore hypothesized that glucose concentrations are decreased in individuals with Chuvash polycythemia. We found that 88 Chuvash VHLR200W homozygotes had lower random glucose and glycosylated hemoglobin A1c levels than 52 Chuvash subjects with wildtype VHL alleles. Serum metabolomics revealed higher glycerol and citrate levels in the VHLR200W homozygotes. We expanded these observations in VHLR200W homozygote mice and found that they had lower fasting glucose values and lower glucose excursions than wild-type control mice but no change in fasting insulin concentrations. Hepatic expression of Glut2 and G6pc but not Pdk2 was decreased and skeletal muscle expression of Glut1, Pdk1 and Pdk4 was increased. These results suggest that both decreased hepatic gluconeogenesis and increased skeletal uptake and glycolysis contribute to the decreased glucose concentrations. Further study is needed to determine whether pharmacologically manipulating HIF expression might be beneficial for treatment of diabetic patients. PMID:23015148

  4. Efeitos do ácido L-glutâmico e da vitamina K na composição bioquímica parcial de fêmures de frangos de corte Effects of dietary L-glutamic acid and K vitamin in the biochemical composition in femurs of broilers at 14 days of age

    Directory of Open Access Journals (Sweden)

    George Henrique Kling de Moraes

    2010-04-01

    Full Text Available Objetivou-se estudar os efeitos da combinação de ácido L-glutâmico (L-Glu e vitamina K na composição bioquímica de fêmures (proteínas colagenosas; não-colagenosas e totais de frangos de corte. O experimento, que teve 14 dias de duração, foi conduzido em delineamento inteiramente casualizado, em fatorial 2 × 4, com dois níveis de ácido L-glutâmico (6,25 e 12,5% combinados com quatro níveis de vitamina K (0,02; 0,2; 2,0 e 20,0 mg/kg de ração, cada combinação com quatro repetições de dez animais. Foram utilizados pintos machos, Avian Farm, de 1 dia, criados em baterias aquecidas e alimentados à vontade com dieta básica contendo L-aminoácidos essenciais, minerais e vitaminas (exceto vitamina K suplementada com ácido L-glutâmico e vitamina K. Ao término do experimento, os animais foram sacrificados por deslocamento cervical e seus fêmures removidos, medidos, desengordurados e pesados. Não foi observada interação significativa entre ácido L-glutâmico e vitamina K para os parâmetros estudados. Os teores de proteínas não-colagenosas foram maiores e o de proteínas colagenosas, menores nos fêmures dos pintos alimentados com a ração com 6,25% de ácido L-glutâmico. Os teores de proteínas totais, no entanto, não foram afetados pelos níveis de ácido L-glutâmico e de vitamina K. Os níveis de vitamina K tiveram efeito quadrático decrescente nos teores de proteínas não-colagenosas e efeito crescente na composição de proteínas colagenosas dos fêmures. A composição em proteínas colagenosas e não-colagenosas pode ser utilizada como indicador bioquímico de anormalidades de pernas causadas por baixo nível de nitrogênio não-específico.This work aimed to study the effects of L-glutamic acid (L-Glu and K vitamin on the biochemical composition (collagenous proteins, CP; non collagenous proteins, NCP; and total proteins, TP in femurs of broilers. The experiment which lasted for 14 days, was carried out in a

  5. APOE ε4, Rated Life Experiences, and Affect among Centenarians

    Science.gov (United States)

    Martin, Peter; Jazwinski, S. Michal; Davey, Adam; Green, Robert; MacDonald, Maurice; Margrett, Jennifer A.; Siegler, Ilene C.; Arnold, Jonathan; Woodard, John; Johnson, Mary Ann; Kim, Sangkyu; Dai, Jianliang; Li, Li; Batzer, Mark A.; Poon, Leonard W.

    2013-01-01

    The purpose of this study was to assess the relationship between APOE, life events and engagement, and subjective well-being (as measured by positive and negative affect) among centenarians. Based on the life stress paradigm, we predicted that higher levels of stress would allow APOE to influence positive and negative affect. One hundred and ninety six centenarians and near centenarians (98 years and older) of the Georgia Centenarian Study participated in this research. APOE, positive and negative affect, number of recent (last two years) and life-long (more than 20 years prior to testing) events, as well as a number of life engagement tasks were assessed. Results suggested that centenarians carrying the APOE ε4 allele rated lower in positive affect, number of life-long events, and in engaged lifestyle when compared to centenarians without the APOE ε4 allele (t = 3.43, p < .01, t = 3.19, p < .01, and t = 2.33, p < .05, respectively). Blockwise multiple regressions indicated that APOE ε4 predicted positive but not negative affect after controlling for demographics. Gene-environment interactions were obtained for APOE ε4 and life-long events, suggesting that carriers of the APOE ε4 allele had higher scores of negative affect after having experienced more events, whereas non-carriers had reduced negative affect levels after having experienced more events. PMID:23998924

  6. Neural activity during affect labeling predicts expressive writing effects on well-being: GLM and SVM approaches.

    Science.gov (United States)

    Memarian, Negar; Torre, Jared B; Haltom, Kate E; Stanton, Annette L; Lieberman, Matthew D

    2017-09-01

    Affect labeling (putting feelings into words) is a form of incidental emotion regulation that could underpin some benefits of expressive writing (i.e. writing about negative experiences). Here, we show that neural responses during affect labeling predicted changes in psychological and physical well-being outcome measures 3 months later. Furthermore, neural activity of specific frontal regions and amygdala predicted those outcomes as a function of expressive writing. Using supervised learning (support vector machines regression), improvements in four measures of psychological and physical health (physical symptoms, depression, anxiety and life satisfaction) after an expressive writing intervention were predicted with an average of 0.85% prediction error [root mean square error (RMSE) %]. The predictions were significantly more accurate with machine learning than with the conventional generalized linear model method (average RMSE: 1.3%). Consistent with affect labeling research, right ventrolateral prefrontal cortex (RVLPFC) and amygdalae were top predictors of improvement in the four outcomes. Moreover, RVLPFC and left amygdala predicted benefits due to expressive writing in satisfaction with life and depression outcome measures, respectively. This study demonstrates the substantial merit of supervised machine learning for real-world outcome prediction in social and affective neuroscience. © The Author (2017). Published by Oxford University Press.

  7. The Child Affective Facial Expression (CAFE) set: validity and reliability from untrained adults.

    Science.gov (United States)

    LoBue, Vanessa; Thrasher, Cat

    2014-01-01

    Emotional development is one of the largest and most productive areas of psychological research. For decades, researchers have been fascinated by how humans respond to, detect, and interpret emotional facial expressions. Much of the research in this area has relied on controlled stimulus sets of adults posing various facial expressions. Here we introduce a new stimulus set of emotional facial expressions into the domain of research on emotional development-The Child Affective Facial Expression set (CAFE). The CAFE set features photographs of a racially and ethnically diverse group of 2- to 8-year-old children posing for six emotional facial expressions-angry, fearful, sad, happy, surprised, and disgusted-and a neutral face. In the current work, we describe the set and report validity and reliability data on the set from 100 untrained adult participants.

  8. Selective enhancement of wnt4 expression by cyclic AMP-associated cooperation between rat central astrocytes and microglia

    International Nuclear Information System (INIS)

    Ohnishi, Masatoshi; Urasaki, Tomoka; Ochiai, Hiroyuki; Matsuoka, Kohei; Takeo, Shin; Harada, Tomoki; Ohsugi, Yoshihito; Inoue, Atsuko

    2015-01-01

    The wnt protein family has important members involved in cell differentiation, proliferation and plasticity expression; however, little is known about its biosynthesis processes. On the other hand, an increase in the intracerebral cyclic adenosine 3′, 5’-monophosphate (cAMP) level leads to synaptic plasticity via the de novo synthesis of any protein. Here, the effect of dibutyryl cAMP (dbcAMP), a membrane permeability cAMP analog, on the wnt family was investigated in rat primary-cultured glial cells containing astrocytes and microglia. Among wnt3a, 4, 5a, 7a and 11 mRNA, only wnt4 expression was increased by longer treatment (24 h), compared with short treatment (2 h), with dbcAMP in a concentration-dependent manner, and its effect reached statistical significance at 1 mM. In cultures of isolated astrocytes or microglia, wnt4 expression was not affected by 1 mM dbcAMP for 24 h, and microglial wnt4 protein was undetectable even when cells were treated with the drug. Mixed glial cells treated for 24 h with 1 mM dbcAMP showed significantly increased wnt4 protein, as well as mRNA. Immunofluorescence manifested that cells that expressed wnt4 protein were astrocytes, but not microglia. Intraperitoneal injection of 1.25 mg/kg rolipram, a phosphodiesterase (PDE) IV inhibitor that can pass through the blood brain barrier and inhibits cAMP degradation specifically, showed a tendency to increase wnt4 expression in the adult rat brain after 24 h, and the increases in wnt4 mRNA and protein levels reached statistical significance in the hippocampus and striatum, respectively. This is the first finding to help elucidate the selective biosynthesis of central wnt4 through cAMP-stimulated microglia and astrocytes interaction. - Highlights: • Dibutyryl cAMP increased wnt4, but not wnt3a, 5a, 7a and 11, mRNA in mixed glia. • Wnt4 protein increased in astrocytes co-cultivated with microglia. • It took a long time to robustly increase wnt4 expression. • Rolipram

  9. Selective enhancement of wnt4 expression by cyclic AMP-associated cooperation between rat central astrocytes and microglia

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Masatoshi, E-mail: ohnishi@fupharm.fukuyama-u.ac.jp [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Urasaki, Tomoka [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Ochiai, Hiroyuki; Matsuoka, Kohei; Takeo, Shin; Harada, Tomoki; Ohsugi, Yoshihito [Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Inoue, Atsuko [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan)

    2015-11-13

    The wnt protein family has important members involved in cell differentiation, proliferation and plasticity expression; however, little is known about its biosynthesis processes. On the other hand, an increase in the intracerebral cyclic adenosine 3′, 5’-monophosphate (cAMP) level leads to synaptic plasticity via the de novo synthesis of any protein. Here, the effect of dibutyryl cAMP (dbcAMP), a membrane permeability cAMP analog, on the wnt family was investigated in rat primary-cultured glial cells containing astrocytes and microglia. Among wnt3a, 4, 5a, 7a and 11 mRNA, only wnt4 expression was increased by longer treatment (24 h), compared with short treatment (2 h), with dbcAMP in a concentration-dependent manner, and its effect reached statistical significance at 1 mM. In cultures of isolated astrocytes or microglia, wnt4 expression was not affected by 1 mM dbcAMP for 24 h, and microglial wnt4 protein was undetectable even when cells were treated with the drug. Mixed glial cells treated for 24 h with 1 mM dbcAMP showed significantly increased wnt4 protein, as well as mRNA. Immunofluorescence manifested that cells that expressed wnt4 protein were astrocytes, but not microglia. Intraperitoneal injection of 1.25 mg/kg rolipram, a phosphodiesterase (PDE) IV inhibitor that can pass through the blood brain barrier and inhibits cAMP degradation specifically, showed a tendency to increase wnt4 expression in the adult rat brain after 24 h, and the increases in wnt4 mRNA and protein levels reached statistical significance in the hippocampus and striatum, respectively. This is the first finding to help elucidate the selective biosynthesis of central wnt4 through cAMP-stimulated microglia and astrocytes interaction. - Highlights: • Dibutyryl cAMP increased wnt4, but not wnt3a, 5a, 7a and 11, mRNA in mixed glia. • Wnt4 protein increased in astrocytes co-cultivated with microglia. • It took a long time to robustly increase wnt4 expression. • Rolipram

  10. The Role of GluK4 in Synaptic Plasticity and Affective Behavior in Mice

    Science.gov (United States)

    Catches, Justin Samuel

    Kainate receptors (KARs) are glutamate-gated ion channels that signal through both ionotropic and metabotropic pathways (Contractor et al., 2011). Combinations of five KAR subunits (GluK1-5) form tetrameric receptors with GluK1, GluK2, and GluK3 able to form functional homomeric channels. The high-affinity subunits, GluK4 and GluK5, do not form homomeric channels but modify the properties of heteromeric receptors. Expression of the GluK4 receptor subunit in the forebrain is restricted to the CA3 region of the hippocampus and dentate gyrus regions where KARs modulate synaptic plasticity. In this study, ablation of Grik4, which encodes GluK4, in mice reduced KAR synaptic currents and altered activation properties of postsynaptic receptors but left two forms of presynaptic short-term plasticity intact. Disruption of both Grik4 and Grik5 caused complete loss of the postsynaptic ionotropic KAR current and impaired presynaptic frequency facilitation. Additionally, KAR surface expression was altered at pre- and postsynaptic sites at the MF synapse. Despite the loss of ionotropic signaling, KAR-mediated inhibition of the slow afterhyperpolarization current, which is dependent on metabotropic signaling, was intact in CA3 neurons. Long-term potentiation at the MF-CA3 synapse was reduced, likely through a loss of KAR modulation of excitability of the presynaptic MF axons. Genetic variants in the human GRIK4 gene alter the susceptibility for affective disorders (Bloss and Hunter, 2010). We found that ablation of Grik4 in mice resulted in reduced anxiety and an antidepressant-like phenotype. In the elevated zero-maze, a test for anxiety and risk taking behavior, and in two anxiogenic tests, marble-burying and novelty-induced suppression of feeding, anxiety-like behavior was consistently reduced in knockout animals. In the forced swim, a test of learned helplessness used to determine depression-like behavior, knockout mice demonstrated significantly less immobility suggesting

  11. Toll-Like Receptor 4 Expression in the Epithelium of Inflammatory Periapical Lesions.

    Science.gov (United States)

    Leonardi, R.; Perrotta, R.E.; Musumeci, G.; Crimi, S.; dos Santos, J.N.; Rusu, M.C.; Bufo, P.; Barbato, E.; Pannone, G.

    2015-01-01

    Toll-like receptors (TLR) are essential for the innate immune response against invading pathogens and have been described in immunocompetent cells of areas affected by periapical disease. Besides initiating the inflammatory response, they also directly regulate epithelial cell proliferation and survival in a variety of settings. This study evaluates the in situ expression of TLR4 in periapical granulomas (PG) and radicular cysts, focusing on the epithelial compartment. Twenty-one periapical cysts (PC) and 10 PG were analyzed; 7 dentigerous non-inflamed follicular cyst (DC) served as control. TLR4 expression was assessed by immunohistochemistry. TLR4 immunoreaction products were detected in the epithelium of all specimens, with a higher percentage of immunostained cells in PG. Although TLR4 overexpression was detected in both PG and PC, there were differences that seemed to be related to the nature of the lesion, since in PG all epithelial cells of strands, islands and trabeculae were strongly immunoreactive for TLR4, whereas in PC only some areas of the basal and suprabasal epithelial layers were immunostained. This staining pattern is consistent with the action of TLR4: in PG it could promote formation of epithelial cell rests of Malassez and in epithelial strands and islands the enhancement of cell survival, proliferation and migration, whereas in PC TLR4 could protect the lining epithelium from extensive apoptosis. These findings go some way towards answering the intriguing question of why many epithelial strands or islands in PG and the lining epithelium of apical cysts regress after non-surgical endodontic therapy, and suggest that TLR4 plays a key role in the pathobiology of the inflammatory process related to periapical disease. PMID:26708181

  12. The correlation between FDG uptake and biological molecular markers in pancreatic cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Kaida, Hayato, E-mail: kaida@med.kindai.ac.jp [Department of Radiology, Kindai University Faculty of Medicine, Osakasayama City, Osaka, 589-8511 (Japan); Azuma, Koichi [Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Kurume City, Fukuoka, 830-0011 (Japan); Kawahara, Akihiko [Department of Diagnostic Pathology, Kurume University Hospital, Kurume City, Fukuoka, 830-0011 (Japan); Yasunaga, Masafumi; Kitasato, Yuhei [Department of Surgery, Kurume University School of Medicine, Kurume City, Fukuoka, 830-0011 (Japan); Hattori, Satoshi [Biostatic Center, Kurume University School of Medicine, Kurume City, Fukuoka, 830-0011 (Japan); Taira, Tomoki [Department of Diagnostic Pathology, Kurume University Hospital, Kurume City, Fukuoka, 830-0011 (Japan); Ureshino, Hiroki [Department of Surgery, Kurume University School of Medicine, Kurume City, Fukuoka, 830-0011 (Japan); Kage, Masayoshi [Department of Diagnostic Pathology, Kurume University Hospital, Kurume City, Fukuoka, 830-0011 (Japan); Ishii, Kazunari; Murakami, Takamichi [Department of Radiology, Kindai University Faculty of Medicine, Osakasayama City, Osaka, 589-8511 (Japan); Ishibashi, Masatoshi [Division of Nuclear Medicine, PET Center, and Department of Radiology, Fukuoka Tokushukai Hospital, Kasuga City, Fukuoka, 816-0864 (Japan)

    2016-10-15

    Purpose: We examined whether fluorine-18 fluorodeoxyglucose (FDG) uptake is related to the mammalian target of rapamycin (mTOR) signal pathway and its related proteins in pancreatic cancer patients. Methods: We retrospectively studied 53 pancreatic cancer patients who underwent FDG positron emission tomography (PET) or FDG PET/CT, and complete curative surgical resection. The SUV max, the tumor to nontumor activity of pancreas [T/N (P)] ratio and the T/N of liver [T/N (L)] ratio were calculated. The expressions of glucose transporter-1(Glut-1) and mTOR pathway proteins in pancreas cell lines were examined by immune blots. Excised tumor tissue was analyzed by immunohistochemistry using monoclonal antibodies for Glut-1, epidermal growth factor receptor (EGFR), mTOR, p70S6kinase (p70S6) and S6 ribosomal protein (S6). Results: The expressions of Glut-1, EGFR and p70S6 were significantly correlated with the SUV max, T/N (P) ratio and T/N (L) ratio. The expressions of mTOR and S6 were not correlated with all parameters. The expression of Glut-1 was positively correlated with the expressions of EGFR and p70S6, but not with mTOR or S6. S6 was positively correlated with p70S6. Conclusions: Glut-1, EGFR and p70S6 expressions are associated with the FDG uptake mechanism of pancreatic cancer. FDG uptake may predict the levels of EGFR and p70S6 expressions, and FDG uptake reflects glucose metabolism and cancer progression.

  13. Korean mistletoe (Viscum album coloratum) extract regulates gene expression related to muscle atrophy and muscle hypertrophy.

    Science.gov (United States)

    Jeong, Juseong; Park, Choon-Ho; Kim, Inbo; Kim, Young-Ho; Yoon, Jae-Min; Kim, Kwang-Soo; Kim, Jong-Bae

    2017-01-21

    Korean mistletoe (Viscum album coloratum) is a semi-parasitic plant that grows on various trees and has a diverse range of effects on biological functions, being implicated in having anti-tumor, immunostimulatory, anti-diabetic, and anti-obesity properties. Recently, we also reported that Korean mistletoe extract (KME) improves endurance exercise in mice, suggesting its beneficial roles in enhancing the capacity of skeletal muscle. We examined the expression pattern of several genes concerned with muscle physiology in C2C12 myotubes cells to identify whether KME inhibits muscle atrophy or promotes muscle hypertrophy. We also investigated these effects of KME in denervated mice model. Interestingly, KME induced the mRNA expression of SREBP-1c, PGC-1α, and GLUT4, known positive regulators of muscle hypertrophy, in C2C12 cells. On the contrary, KME reduced the expression of Atrogin-1, which is directly involved in the induction of muscle atrophy. In animal models, KME mitigated the decrease of muscle weight in denervated mice. The expression of Atrogin-1 was also diminished in those mice. Moreover, KME enhanced the grip strength and muscle weight in long-term feeding mice. Our results suggest that KME has beneficial effects on muscle atrophy and muscle hypertrophy.

  14. Age-related hearing loss: Aquaporin 4 gene expression changes in the mouse cochlea and auditory midbrain

    Science.gov (United States)

    Christensen, Nathan; D'Souza, Mary; Zhu, Xiaoxia; Frisina, Robert D.

    2009-01-01

    Presbycusis – age-related hearing loss, is the number one communication disorder, and one of the top three chronic medical conditions of our aged population. Aquaporins, particularly aquaporin 4 (Aqp4), are membrane proteins with important roles in water and ion flux across cell membranes, including cells of the inner ear and pathways of the brain used for hearing. To more fully understand the biological bases of presbycusis, 39 CBA mice, a well-studied animal model of presbycusis, underwent non-invasive hearing testing as a function of sound frequency (auditory brainstem response – ABR thresholds, and distortion-product otoacoustic emission – DPOAE magnitudes), and were clustered into four groups based on age and hearing ability. Aqp4 gene expression, as determined by genechip microarray analysis and quantitative real-time PCR, was compared to the young adult control group in the three older groups: middle aged with good hearing, old age with mild presbycusis, and old age with severe presbycusis. Linear regression and ANOVA showed statistically significant changes in Aqp4 gene expression and ABR and DPOAE hearing status in the cochlea and auditory midbrain – inferior colliculus. Down-regulation in the cochlea was seen, and an initial down-, then up-regulation was discovered for the inferior colliculus Aqp4 expression. It is theorized that these changes in Aqp4 gene expression represent an age-related disruption of ion flux in the fluids of the cochlea that are responsible for ionic gradients underlying sound transduction in cochlear hair cells necessary for hearing. In regard to central auditory processing at the level of the auditory midbrain, aquaporin gene expression changes may affect neurotransmitter cycling involving supporting cells, thus impairing complex sound neural processing with age. PMID:19070604

  15. Myeloid-Cell-Derived VEGF Maintains Brain Glucose Uptake and Limits Cognitive Impairment in Obesity.

    Science.gov (United States)

    Jais, Alexander; Solas, Maite; Backes, Heiko; Chaurasia, Bhagirath; Kleinridders, André; Theurich, Sebastian; Mauer, Jan; Steculorum, Sophie M; Hampel, Brigitte; Goldau, Julia; Alber, Jens; Förster, Carola Y; Eming, Sabine A; Schwaninger, Markus; Ferrara, Napoleone; Karsenty, Gerard; Brüning, Jens C

    2016-05-05

    High-fat diet (HFD) feeding induces rapid reprogramming of systemic metabolism. Here, we demonstrate that HFD feeding of mice downregulates glucose transporter (GLUT)-1 expression in blood-brain barrier (BBB) vascular endothelial cells (BECs) and reduces brain glucose uptake. Upon prolonged HFD feeding, GLUT1 expression is restored, which is paralleled by increased expression of vascular endothelial growth factor (VEGF) in macrophages at the BBB. In turn, inducible reduction of GLUT1 expression specifically in BECs reduces brain glucose uptake and increases VEGF serum concentrations in lean mice. Conversely, myeloid-cell-specific deletion of VEGF in VEGF(Δmyel) mice impairs BBB-GLUT1 expression, brain glucose uptake, and memory formation in obese, but not in lean mice. Moreover, obese VEGF(Δmyel) mice exhibit exaggerated progression of cognitive decline and neuroinflammation on an Alzheimer's disease background. These experiments reveal that transient, HFD-elicited reduction of brain glucose uptake initiates a compensatory increase of VEGF production and assign obesity-associated macrophage activation a homeostatic role to restore cerebral glucose metabolism, preserve cognitive function, and limit neurodegeneration in obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. GnRH-agonist implants suppress reproductive function and affects ovarian LHR and FSHR expression in prepubertal female cats.

    Science.gov (United States)

    Mehl, N S; Srisuwatanasagul, S; Swangchan-Uthai, T; Sirivaidyapong, S; Khalid, M

    2017-01-01

    Effect of a GnRH-agonist (deslorelin) was studied on reproductive function and ovarian luteinizing hormone receptor (LHR) and follicle stimulating hormone receptor (FSHR) expression in prepubertal female cats that were either implanted with 4.7-mg deslorelin (implanted: n = 6) or not (controls: n = 18) or ovariohysterectomized at prepubertal age (prepubertal OVH: n = 6). Body weights, fecal estradiol, and sexual behavior of implanted and control cats were monitored for 48 weeks followed by collection of ovaries and uteri. Ovaries and uteri were collected from control cats at follicular, luteal, and inactive stage (n = 6/group) and from prepubertal OVH cats at prepubertal age. Ovaries and uteri were analyzed for anatomical/histological characteristics. Ovaries were also analyzed for LHR and FSHR expression. Statistical analysis showed higher (P ≤ 0.05) body weight in control than implanted cats only during 22nd to 26th weeks of the study. Estrus was observed in control cats only. Deslorelin reduced (P ≤ 0.05) ovarian weight and number of antral follicles but did not affect endometrial thickness and gland diameter. However, myometrial thickness of implanted cats was significantly lower than control cats at follicular and luteal stage. Ovarian LHR mRNA expression was lower (P ≤ 0.05) in implanted cats than control cats at follicular stage. FSHR mRNA and LHR protein expression did not differ among the three groups. FSHR protein expression was lower (P ≤ 0.05) in prepubertal OVH cats and was not affected by deslorelin. In conclusion, deslorelin suppresses reproductive function in prepubertal female cats for at least 48 weeks possibly through a change in the ovarian mRNA expression of LHR. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Exercise Increases Insulin Sensitivity and Skeletal Muscle AMPK Expression in Systemic Lupus Erythematosus: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Fabiana B. Benatti

    2018-04-01

    significant differences between groups were observed in Akt Ser 473 phosphorylation, total and membrane GLUT4 expression, and GLUT4 translocation (all p > 0.05. In conclusion, a 12-week moderate-intensity aerobic exercise training program improved insulin sensitivity in SLE patients with mild/inactive disease. This effect appears to be partially mediated by the increased insulin-stimulated skeletal muscle AMPK phosphorylation.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier NCT01515163.

  18. Restoration of type 1 iodothyronine deiodinase expression in renal cancer cells downregulates oncoproteins and affects key metabolic pathways as well as anti-oxidative system.

    Science.gov (United States)

    Popławski, Piotr; Wiśniewski, Jacek R; Rijntjes, Eddy; Richards, Keith; Rybicka, Beata; Köhrle, Josef; Piekiełko-Witkowska, Agnieszka

    2017-01-01

    Type 1 iodothyronine deiodinase (DIO1) contributes to deiodination of 3,5,3',5'-tetraiodo-L-thyronine (thyroxine, T4) yielding of 3,5,3'-triiodothyronine (T3), a powerful regulator of cell differentiation, proliferation, and metabolism. Our previous work showed that loss of DIO1 enhances proliferation and migration of renal cancer cells. However, the global effects of DIO1 expression in various tissues affected by cancer remain unknown. Here, the effects of stable DIO1 re-expression were analyzed on the proteome of renal cancer cells, followed by quantitative real-time PCR validation in two renal cancer-derived cell lines. DIO1-induced changes in intracellular concentrations of thyroid hormones were quantified by L-MS/MS and correlations between expression of DIO1 and potential target genes were determined in tissue samples from renal cancer patients. Stable re-expression of DIO1, resulted in 26 downregulated proteins while 59 proteins were overexpressed in renal cancer cells. The 'downregulated' group consisted mainly of oncoproteins (e.g. STAT3, ANPEP, TGFBI, TGM2) that promote proliferation, migration and invasion. Furthermore, DIO1 re-expression enhanced concentrations of two subunits of thyroid hormone transporter (SLC7A5, SLC3A2), enzymes of key pathways of cellular energy metabolism (e.g. TKT, NAMPT, IDH2), sex steroid metabolism and anti-oxidative response (AKR1C2, AKR1B10). DIO1 expression resulted in elevated intracellular concentration of T4. Expression of DIO1-affected genes strongly correlated with DIO1 transcript levels in tissue samples from renal cancer patients as well as with their poor survival. This first study addressing effects of deiodinase re-expression on proteome of cancer cells demonstrates that induced DIO1 re-expression in renal cancer robustly downregulates oncoproteins, affects key metabolic pathways, and triggers proteins involved in anti-oxidative protection. This data supports the notion that suppressed DIO1 expression and changes

  19. Restoration of type 1 iodothyronine deiodinase expression in renal cancer cells downregulates oncoproteins and affects key metabolic pathways as well as anti-oxidative system.

    Directory of Open Access Journals (Sweden)

    Piotr Popławski

    Full Text Available Type 1 iodothyronine deiodinase (DIO1 contributes to deiodination of 3,5,3',5'-tetraiodo-L-thyronine (thyroxine, T4 yielding of 3,5,3'-triiodothyronine (T3, a powerful regulator of cell differentiation, proliferation, and metabolism. Our previous work showed that loss of DIO1 enhances proliferation and migration of renal cancer cells. However, the global effects of DIO1 expression in various tissues affected by cancer remain unknown. Here, the effects of stable DIO1 re-expression were analyzed on the proteome of renal cancer cells, followed by quantitative real-time PCR validation in two renal cancer-derived cell lines. DIO1-induced changes in intracellular concentrations of thyroid hormones were quantified by L-MS/MS and correlations between expression of DIO1 and potential target genes were determined in tissue samples from renal cancer patients. Stable re-expression of DIO1, resulted in 26 downregulated proteins while 59 proteins were overexpressed in renal cancer cells. The 'downregulated' group consisted mainly of oncoproteins (e.g. STAT3, ANPEP, TGFBI, TGM2 that promote proliferation, migration and invasion. Furthermore, DIO1 re-expression enhanced concentrations of two subunits of thyroid hormone transporter (SLC7A5, SLC3A2, enzymes of key pathways of cellular energy metabolism (e.g. TKT, NAMPT, IDH2, sex steroid metabolism and anti-oxidative response (AKR1C2, AKR1B10. DIO1 expression resulted in elevated intracellular concentration of T4. Expression of DIO1-affected genes strongly correlated with DIO1 transcript levels in tissue samples from renal cancer patients as well as with their poor survival. This first study addressing effects of deiodinase re-expression on proteome of cancer cells demonstrates that induced DIO1 re-expression in renal cancer robustly downregulates oncoproteins, affects key metabolic pathways, and triggers proteins involved in anti-oxidative protection. This data supports the notion that suppressed DIO1 expression

  20. Calling genotypes from public RNA-sequencing data enables identification of genetic variants that affect gene-expression levels

    NARCIS (Netherlands)

    Deelen, Patrick; Zhernakova, Daria V.; de Haan, Mark; van der Sijde, Marijke; Bonder, Marc Jan; Karjalainen, Juha; van der Velde, K. Joeri; Abbott, Kristin M.; Fu, Jingyuan; Wijmenga, Cisca; Sinke, Richard J.; Swertz, Morris A.; Franke, Lude

    2015-01-01

    Background: RNA-sequencing (RNA-seq) is a powerful technique for the identification of genetic variants that affect gene-expression levels, either through expression quantitative trait locus (eQTL) mapping or through allele-specific expression (ASE) analysis. Given increasing numbers of RNA-seq