1
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Peng Q, Zeng W. The protective role of endothelial GLUT1 in ischemic stroke. Brain Behav 2024; 14:e3536. [PMID: 38747733 PMCID: PMC11095318 DOI: 10.1002/brb3.3536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 05/18/2024] Open
Abstract
OBJECTIVE To provide thorough insight on the protective role of endothelial glucose transporter 1 (GLUT1) in ischemic stroke. METHODS We comprehensively review the role of endothelial GLUT1 in ischemic stroke by narrating the findings concerning biological characteristics of GLUT1 in brain in depth, summarizing the changes of endothelial GLUT1 expression and activity during ischemic stroke, discussing how GLUT1 achieves its neuroprotective effect via maintaining endothelial function, and identifying some outstanding blind spots in current studies. RESULTS Endothelial GLUT1 maintains persistent high glucose and energy requirements of the brain by transporting glucose through the blood-brain barrier, which preserves endothelial function and is beneficial to stroke prognosis. CONCLUSION This review underscores the potential involvement of GLUT1 trafficking, activity modulation, and degradation, and we look forward to more clinical and animal studies to illuminate these mechanisms.
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Affiliation(s)
- Qiwei Peng
- Department of Critical Care Medicine, Union HospitalTongji Medical College, Huazhong University of Science and TechnologyWuhanChina
- Key Laboratory of Anesthesiology and Resuscitation (Huazhong University of Science and Technology)Ministry of EducationWuhanChina
| | - Weiqi Zeng
- Department of NeurologyThe First People's Hospital of FoshanFoshanChina
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2
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Trocmé C, Gonnet N, Di Tommaso M, Samouda H, Cracowski JL, Cracowski C, Lambert-Porcheron S, Laville M, Nobécourt E, Gaddhab C, Le Lay A, Bohn T, Poitou C, Clément K, Al-Mulla F, Bitar MS, Bottari SP. Serum IRAP, a Novel Direct Biomarker of Prediabetes and Type 2 Diabetes? Front Mol Biosci 2021; 7:596141. [PMID: 33665204 PMCID: PMC7921167 DOI: 10.3389/fmolb.2020.596141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/23/2020] [Indexed: 01/03/2023] Open
Abstract
Insulin resistance (IR), currently called prediabetes (PD), affects more than half of the adult population worldwide. Type 2 diabetes (T2D), which often follows in the absence of treatment, affects more than 475 million people and represents 10–20% of the health budget in industrialized countries. A preventive public health policy is urgently needed in order to stop this constantly progressing epidemic. Indeed, early management of prediabetes does not only strongly reduce its evolution toward T2D but also strongly reduces the appearance of cardiovascular comorbidity as well as that of associated cancers. There is however currently no simple and reliable test available for the diagnosis or screening of prediabetes and it is generally estimated that 20–60% of diabetics are not diagnosed. We therefore developed an ELISA for the quantitative determination of serum Insulin-Regulated AminoPeptidase (IRAP). IRAP is associated with and translocated in a stoechiometric fashion to the plasma membrane together with GLUT4 in response to insulin in skeletal muscle and adipose tissue which are the two major glucose storage sites. Its extracellular domain (IRAPs) is subsequently cleaved and secreted in the blood stream. In T2D, IRAP translocation in response to insulin is strongly decreased. Our patented sandwich ELISA is highly sensitive (≥10.000-fold “normal” fasting concentrations) and specific, robust and very cost-effective. Dispersion of fasting plasma concentration values in a healthy population is very low (101.4 ± 15.9 μg/ml) as compared to those of insulin (21–181 pmol/l) and C-peptide (0.4–1.7 nmol/l). Results of pilot studies indicate a clear correlation between IRAPs levels and insulin sensitivity. We therefore think that plasma IRAPs may be a direct marker of insulin sensitivity and that the quantitative determination of its plasma levels should allow large-scale screening of populations at risk for PD and T2D, thereby allow the enforcement of a preventive health policy aiming at efficiently reducing this epidemic.
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Affiliation(s)
- Candice Trocmé
- Department of Biochemistry, Molecular Biology and Environmental Toxicology, Centre Hospitalier Grenoble-Alpes, La Tronche, France
| | - Nicolas Gonnet
- Centre d'Investigation Clinique, Centre Hospitalier Grenoble-Alpes, La Tronche, France
| | - Margaux Di Tommaso
- Population Health Department, Nutrition and Health Research Group, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Hanen Samouda
- Population Health Department, Nutrition and Health Research Group, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Jean-Luc Cracowski
- Centre d'Investigation Clinique, Centre Hospitalier Grenoble-Alpes, La Tronche, France.,Medical School, Université Grenoble Alpes, La Tronche, France.,INSERM U1042 Laboratoire Hypoxie et Physiopathologies cardiovasculaires et respiratoires (HP2), Grenoble, France
| | - Claire Cracowski
- Centre d'Investigation Clinique, Centre Hospitalier Grenoble-Alpes, La Tronche, France
| | | | - Martine Laville
- Centre de Recherche en Nutrition Humaine Rhône-Alpes, Pierre-Bénite, France.,CH Lyon Sud, Lyon, France.,INSERM U1060 Laboratoire de Recherche en Cardiovasculaire, Métabolisme, diabétologie et Nutrition, Oullins, France
| | - Estelle Nobécourt
- Department of Endocrinology, Metabolic Diseases and Nutrition, Centre Hospitalier Universitaire de La Réunion, Saint-Denis, France
| | - Chiraz Gaddhab
- Department of Pediatrics, Diabetes and Endocrinology Care, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Allan Le Lay
- CHU Grenoble-Alpes, Department of Biochemistry, Molecular Biology and Environmental Toxicology, Grenoble, France
| | - Torsten Bohn
- Population Health Department, Nutrition and Health Research Group, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Christine Poitou
- INSERM UMR-S 1269, NutriOmics, Paris, France.,Medical School, Sorbonne Universités, Paris, France
| | - Karine Clément
- INSERM UMR-S 1269, NutriOmics, Paris, France.,Medical School, Sorbonne Universités, Paris, France
| | - Fahd Al-Mulla
- Department of Genomics and Bioinformatics, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Milad S Bitar
- Department of Genomics and Bioinformatics, Dasman Diabetes Institute, Kuwait City, Kuwait.,Department of Pharmacology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Serge P Bottari
- Population Health Department, Nutrition and Health Research Group, Luxembourg Institute of Health, Luxembourg, Luxembourg.,GREPI, UMR5525 Techniques de l'Ingénierie Médicale et de la Complexité Informatique, Mathématiques et Applications, Grenoble (TIMC-IMAG), La Tronche, France.,Faculté de Médecine, Université Grenoble Alpes, La Tronche, France.,Centre Hospitalier Grenoble-Alpes, La Tronche, France
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3
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Exploring cellular markers of metabolic syndrome in peripheral blood mononuclear cells across the neuropsychiatric spectrum. Brain Behav Immun 2021; 91:673-682. [PMID: 32898636 DOI: 10.1016/j.bbi.2020.07.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/18/2022] Open
Abstract
Recent evidence suggests that comorbidities between neuropsychiatric conditions and metabolic syndrome may precede and even exacerbate long-term side-effects of psychiatric medication, such as a higher risk of type 2 diabetes and cardiovascular disease, which result in increased mortality. In the present study we compare the expression of key metabolic proteins, including the insulin receptor (CD220), glucose transporter 1 (GLUT1) and fatty acid translocase (CD36), on peripheral blood mononuclear cell subtypes from patients across the neuropsychiatric spectrum, including schizophrenia, bipolar disorder, major depression and autism spectrum conditions (n = 25/condition), relative to typical controls (n = 100). This revealed alterations in the expression of these proteins that were specific to schizophrenia. Further characterization of metabolic alterations in an extended cohort of first-onset antipsychotic drug-naïve schizophrenia patients (n = 58) and controls (n = 63) revealed that the relationship between insulin receptor expression in monocytes and physiological insulin sensitivity was disrupted in schizophrenia and that altered expression of the insulin receptor was associated with whole genome polygenic risk scores for schizophrenia. Finally, longitudinal follow-up of the schizophrenia patients over the course of antipsychotic drug treatment revealed that peripheral metabolic markers predicted changes in psychopathology and the principal side effect of weight gain at clinically relevant time points. These findings suggest that peripheral blood cells can provide an accessible surrogate model for metabolic alterations in schizophrenia and have the potential to stratify subgroups of patients with different clinical outcomes or a greater risk of developing metabolic complications following antipsychotic therapy.
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4
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Honkala SM, Motiani P, Kivelä R, Hemanthakumar KA, Tolvanen E, Motiani KK, Eskelinen JJ, Virtanen KA, Kemppainen J, Heiskanen MA, Löyttyniemi E, Nuutila P, Kalliokoski KK, Hannukainen JC. Exercise training improves adipose tissue metabolism and vasculature regardless of baseline glucose tolerance and sex. BMJ Open Diabetes Res Care 2020; 8:e000830. [PMID: 32816872 PMCID: PMC7437884 DOI: 10.1136/bmjdrc-2019-000830] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 05/08/2020] [Accepted: 06/10/2020] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION We investigated the effects of a supervised progressive sprint interval training (SIT) and moderate-intensity continuous training (MICT) on adipocyte morphology and adipose tissue metabolism and function; we also tested whether the responses were similar regardless of baseline glucose tolerance and sex. RESEARCH DESIGN AND METHODS 26 insulin-resistant (IR) and 28 healthy participants were randomized into 2-week-long SIT (4-6×30 s at maximum effort) and MICT (40-60 min at 60% of maximal aerobic capacity (VO2peak)). Insulin-stimulated glucose uptake and fasting-free fatty acid uptake in visceral adipose tissue (VAT), abdominal and femoral subcutaneous adipose tissues (SATs) were quantified with positron emission tomography. Abdominal SAT biopsies were collected to determine adipocyte morphology, gene expression markers of lipolysis, glucose and lipid metabolism and inflammation. RESULTS Training increased glucose uptake in VAT (p<0.001) and femoral SAT (p<0.001) and decreased fatty acid uptake in VAT (p=0.01) irrespective of baseline glucose tolerance and sex. In IR participants, training increased adipose tissue vasculature and decreased CD36 and ANGPTL4 gene expression in abdominal SAT. SIT was superior in increasing VO2peak and VAT glucose uptake in the IR group, whereas MICT reduced VAT fatty acid uptake more than SIT. CONCLUSIONS Short-term training improves adipose tissue metabolism both in healthy and IR participants independently of the sex. Adipose tissue angiogenesis and gene expression was only significantly affected in IR participants.
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Affiliation(s)
| | | | - Riikka Kivelä
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | | | - Erik Tolvanen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Turku, Finland
- Turku PET Centre, Turku University Hospital, Turku, Finland
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5
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Morris S, Geoghegan ND, Sadler JBA, Koester AM, Black HL, Laub M, Miller L, Heffernan L, Simpson JC, Mastick CC, Cooper J, Gadegaard N, Bryant NJ, Gould GW. Characterisation of GLUT4 trafficking in HeLa cells: comparable kinetics and orthologous trafficking mechanisms to 3T3-L1 adipocytes. PeerJ 2020; 8:e8751. [PMID: 32185116 PMCID: PMC7060922 DOI: 10.7717/peerj.8751] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/14/2020] [Indexed: 12/18/2022] Open
Abstract
Insulin-stimulated glucose transport is a characteristic property of adipocytes and muscle cells and involves the regulated delivery of glucose transporter (GLUT4)-containing vesicles from intracellular stores to the cell surface. Fusion of these vesicles results in increased numbers of GLUT4 molecules at the cell surface. In an attempt to overcome some of the limitations associated with both primary and cultured adipocytes, we expressed an epitope- and GFP-tagged version of GLUT4 (HA–GLUT4–GFP) in HeLa cells. Here we report the characterisation of this system compared to 3T3-L1 adipocytes. We show that insulin promotes translocation of HA–GLUT4–GFP to the surface of both cell types with similar kinetics using orthologous trafficking machinery. While the magnitude of the insulin-stimulated translocation of GLUT4 is smaller than mouse 3T3-L1 adipocytes, HeLa cells offer a useful, experimentally tractable, human model system. Here, we exemplify their utility through a small-scale siRNA screen to identify GOSR1 and YKT6 as potential novel regulators of GLUT4 trafficking in human cells.
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Affiliation(s)
- Silke Morris
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK
| | | | - Jessica B A Sadler
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK
| | - Anna M Koester
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK
| | | | - Marco Laub
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK
| | - Lucy Miller
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK
| | - Linda Heffernan
- School of Biology & Environmental Science, University College Dublin, Dublin, Ireland
| | - Jeremy C Simpson
- School of Biology & Environmental Science, University College Dublin, Dublin, Ireland
| | | | - Jon Cooper
- School of Engineering, University of Glasgow, Glasgow, UK
| | | | - Nia J Bryant
- Department of Biology, University of York, York, UK
| | - Gwyn W Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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6
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Hammarstedt A, Gogg S, Hedjazifar S, Nerstedt A, Smith U. Impaired Adipogenesis and Dysfunctional Adipose Tissue in Human Hypertrophic Obesity. Physiol Rev 2019; 98:1911-1941. [PMID: 30067159 DOI: 10.1152/physrev.00034.2017] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The subcutaneous adipose tissue (SAT) is the largest and best storage site for excess lipids. However, it has a limited ability to expand by recruiting and/or differentiating available precursor cells. When inadequate, this leads to a hypertrophic expansion of the cells with increased inflammation, insulin resistance, and a dysfunctional prolipolytic tissue. Epi-/genetic factors regulate SAT adipogenesis and genetic predisposition for type 2 diabetes is associated with markers of an impaired SAT adipogenesis and development of hypertrophic obesity also in nonobese individuals. We here review mechanisms for the adipose precursor cells to enter adipogenesis, emphasizing the role of bone morphogenetic protein-4 (BMP-4) and its endogenous antagonist gremlin-1, which is increased in hypertrophic SAT in humans. Gremlin-1 is a secreted and a likely important mechanism for the impaired SAT adipogenesis in hypertrophic obesity. Transiently increasing BMP-4 enhances adipogenic commitment of the precursor cells while maintained BMP-4 signaling during differentiation induces a beige/brown oxidative phenotype in both human and murine adipose cells. Adipose tissue growth and development also requires increased angiogenesis, and BMP-4, as a proangiogenic molecule, may also be an important feedback regulator of this. Hypertrophic obesity is also associated with increased lipolysis. Reduced lipid storage and increased release of FFA by hypertrophic SAT are important mechanisms for the accumulation of ectopic fat in the liver and other places promoting insulin resistance. Taken together, the limited expansion and storage capacity of SAT is a major driver of the obesity-associated metabolic complications.
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Affiliation(s)
- Ann Hammarstedt
- Department of Molecular and Clinical Medicine, The Lundberg Laboratory for Diabetes Research, the Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Silvia Gogg
- Department of Molecular and Clinical Medicine, The Lundberg Laboratory for Diabetes Research, the Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Shahram Hedjazifar
- Department of Molecular and Clinical Medicine, The Lundberg Laboratory for Diabetes Research, the Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Annika Nerstedt
- Department of Molecular and Clinical Medicine, The Lundberg Laboratory for Diabetes Research, the Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Ulf Smith
- Department of Molecular and Clinical Medicine, The Lundberg Laboratory for Diabetes Research, the Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
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7
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Exercise during pregnancy and its impact on mothers and offspring in humans and mice. J Dev Orig Health Dis 2017; 9:63-76. [DOI: 10.1017/s2040174417000617] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Exercise during pregnancy has beneficial effects on maternal and offspring’s health in humans and mice. The underlying mechanisms remain unclear. This comparative study aimed to determine the long-term effects of an exercise program on metabolism, weight gain, body composition and changes in hormones [insulin, leptin, brain-derived neurotrophic factor (BDNF)]. Pregnant women (n=34) and mouse dams (n=44) were subjected to an exercise program compared with matched controls (period I). Follow-up in the offspring was performed over 6 months in humans, corresponding to postnatal day (P) 21 in mice (period II). Half of the mouse offspring was challenged with a high-fat diet (HFD) for 6 weeks between P70 and P112 (period III). In period I, exercise during pregnancy led to 6% lower fat content, 40% lower leptin levels and an increase of 50% BDNF levels in humans compared with controls, which was not observed in mice. After period II in humans and mice, offspring body weight did not differ from that of the controls. Further differences were observed in period III. Offspring of exercising mouse dams had significantly lower fat mass and leptin levels compared with controls. In addition, at P112, BDNF levels in offspring were significantly higher from exercising mothers while this effect was completely blunted by HFD feeding. In this study, we found comparable effects on maternal and offspring’s weight gain in humans and mice but different effects in insulin, leptin and BDNF. The long-term potential protective effects of exercise on biomarkers should be examined in human studies.
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8
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Sadler JBA, Roccisana J, Virolainen M, Bryant NJ, Gould GW. mVps45 knockdown selectively modulates VAMP expression in 3T3-L1 adipocytes. Commun Integr Biol 2015; 8:e1026494. [PMID: 26479872 PMCID: PMC4594494 DOI: 10.1080/19420889.2015.1026494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 08/05/2014] [Accepted: 08/06/2014] [Indexed: 02/08/2023] Open
Abstract
Insulin stimulates the delivery of glucose transporter-4 (GLUT4)-containing vesicles to the surface of adipocytes. Depletion of the Sec1/Munc18 protein mVps45 significantly abrogates insulin-stimulated glucose transport and GLUT4 translocation. Here we show that depletion of mVps45 selectively reduced expression of VAMPs 2 and 4, but not other VAMP isoforms. Although we did not observe direct interaction of mVps45 with any VAMP isoform; we found that the cognate binding partner of mVps45, Syntaxin 16 associates with VAMPs 2, 4, 7 and 8 in vitro. Co-immunoprecipitation experiments in 3T3-L1 adipocytes revealed an interaction between Syntaxin 16 and only VAMP4. We suggest GLUT4 trafficking is controlled by the coordinated expression of mVps45/Syntaxin 16/VAMP4, and that depletion of mVps45 regulates VAMP2 levels indirectly, perhaps via reduced trafficking into specialized subcellular compartments.
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Affiliation(s)
- Jessica B A Sadler
- Henry Wellcome Laboratory of Cell Biology; Institute of Molecular; Cell and Systems Biology; College of Medical; Veterinary and Life Sciences; University of Glasgow ; Glasgow, Scotland
| | - Jennifer Roccisana
- Henry Wellcome Laboratory of Cell Biology; Institute of Molecular; Cell and Systems Biology; College of Medical; Veterinary and Life Sciences; University of Glasgow ; Glasgow, Scotland
| | - Minttu Virolainen
- Henry Wellcome Laboratory of Cell Biology; Institute of Molecular; Cell and Systems Biology; College of Medical; Veterinary and Life Sciences; University of Glasgow ; Glasgow, Scotland
| | - Nia J Bryant
- Department of Biology; University of York ; Heslington, York
| | - Gwyn W Gould
- Henry Wellcome Laboratory of Cell Biology; Institute of Molecular; Cell and Systems Biology; College of Medical; Veterinary and Life Sciences; University of Glasgow ; Glasgow, Scotland
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9
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Soliman H, Nyamandi V, Garcia-Patino M, Varela JN, Bankar G, Lin G, Jia Z, MacLeod KM. Partial deletion of ROCK2 protects mice from high-fat diet-induced cardiac insulin resistance and contractile dysfunction. Am J Physiol Heart Circ Physiol 2015; 309:H70-81. [PMID: 25910808 DOI: 10.1152/ajpheart.00664.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 04/06/2015] [Indexed: 01/13/2023]
Abstract
Obesity is associated with cardiac insulin resistance and contractile dysfunction, which contribute to the development of heart failure. The RhoA-Rho kinase (ROCK) pathway has been reported to modulate insulin resistance, but whether it is implicated in obesity-induced cardiac dysfunction is not known. To test this, wild-type (WT) and ROCK2(+/-) mice were fed normal chow or a high-fat diet (HFD) for 17 wk. Whole body insulin resistance, determined by an insulin tolerance test, was observed in HFD-WT, but not HFD-ROCK2(+/-), mice. The echocardiographically determined myocardial performance index, a measure of global systolic and diastolic function, was significantly increased in HFD-WT mice, indicating a deterioration of cardiac function. However, no change in myocardial performance index was found in hearts from HFD-ROCK2(+/-) mice. Speckle-tracking-based strain echocardiography also revealed regional impairment in left ventricular wall motion in hearts from HFD-WT, but not HFD-ROCK2(+/-), mice. Activity of ROCK1 and ROCK2 was significantly increased in hearts from HFD-WT mice, and GLUT4 expression was significantly reduced. Insulin-induced phosphorylation of insulin receptor substrate (IRS) Tyr(612), Akt, and AS160 was also impaired in these hearts, while Ser(307) phosphorylation of IRS was increased. In contrast, the increase in ROCK2, but not ROCK1, activity was prevented in hearts from HFD-ROCK2(+/-) mice, and cardiac levels of TNFα were reduced. This was associated with normalization of IRS phosphorylation, downstream insulin signaling, and GLUT4 expression. These data suggest that increased activation of ROCK2 contributes to obesity-induced cardiac dysfunction and insulin resistance and that inhibition of ROCK2 may constitute a novel approach to treat this condition.
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Affiliation(s)
- Hesham Soliman
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minia, Egypt; and
| | - Vongai Nyamandi
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marysol Garcia-Patino
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Julia Nogueira Varela
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Girish Bankar
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Guorong Lin
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zhengping Jia
- Neurosciences and Mental Health, Hospital for Sick Children, and Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Kathleen M MacLeod
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada;
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10
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Calvo MB, Figueroa A, Pulido EG, Campelo RG, Aparicio LA. Potential role of sugar transporters in cancer and their relationship with anticancer therapy. Int J Endocrinol 2010; 2010:205357. [PMID: 20706540 PMCID: PMC2913528 DOI: 10.1155/2010/205357] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 06/20/2010] [Indexed: 12/18/2022] Open
Abstract
Sugars, primarily glucose and fructose, are the main energy source of cells. Because of their hydrophilic nature, cells use a number of transporter proteins to introduce sugars through their plasma membrane. Cancer cells are well known to display an enhanced sugar uptake and consumption. In fact, sugar transporters are deregulated in cancer cells so they incorporate higher amounts of sugar than normal cells. In this paper, we compile the most significant data available about biochemical and biological properties of sugar transporters in normal tissues and we review the available information about sugar carrier expression in different types of cancer. Moreover, we describe the possible pharmacological interactions between drugs currently used in anticancer therapy and the expression or function of facilitative sugar transporters. Finally, we also go into the insights about the future design of drugs targeted against sugar utilization in cancer cells.
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Affiliation(s)
- Moisés Blanco Calvo
- Biomedical Research Institute, A Coruña University Hospital, As Xubias 84, 15006 A Coruña, Spain
| | - Angélica Figueroa
- Biomedical Research Institute, A Coruña University Hospital, As Xubias 84, 15006 A Coruña, Spain
| | - Enrique Grande Pulido
- Clinical Oncology Department, Ramón y Cajal University Hospital, Ctra. de Colmenar Viejo Km. 9,100, 28034 Madrid, Spain
| | - Rosario García Campelo
- Clinical Oncology Department, A Coruña University Hospital, As Xubias 84, 15006 A Coruña, Spain
| | - Luís Antón Aparicio
- Clinical Oncology Department, A Coruña University Hospital, As Xubias 84, 15006 A Coruña, Spain
- Medicine Department, University of A Coruña, Oza s/n, 15006 A Coruña, Spain
- *Luís Antón Aparicio:
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11
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Abstract
Emerging evidence suggests that increased dietary consumption of fructose in Western society may be a potentially important factor in the growing rates of obesity and the metabolic syndrome. This review will discuss fructose-induced perturbations in cell signaling and inflammatory cascades in insulin-sensitive tissues. In particular, the roles of cellular signaling molecules including nuclear factor kappa B (NFkB), tumor necrosis factor alpha (TNF-alpha), c-Jun amino terminal kinase 1 (JNK-1), protein tyrosine phosphatase 1B (PTP-1B), phosphatase and tensin homolog deleted on chromosome ten (PTEN), liver X receptor (LXR), farnesoid X receptor (FXR), and sterol regulatory element-binding protein-1c (SREBP-1c) will be addressed. Considering the prevalence and seriousness of the metabolic syndrome, further research on the underlying molecular mechanisms and preventative and curative strategies is warranted.
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Affiliation(s)
- Angela C Rutledge
- Department of Clinical Biochemistry and Molecular Structure and Function, University of Toronto, Ontario, Canada
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12
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Armoni M, Harel C, Bar-Yoseph F, Milo S, Karnieli E. Free fatty acids repress the GLUT4 gene expression in cardiac muscle via novel response elements. J Biol Chem 2005; 280:34786-95. [PMID: 16096283 DOI: 10.1074/jbc.m502740200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Hyperlipidemia (HL) impairs cardiac glucose homeostasis, but the molecular mechanisms involved are yet unclear. We examined HL-regulated GLUT4 and peroxisome proliferator-activated receptor (PPAR) gamma gene expression in human cardiac muscle. Compared with control patients, GLUT4 protein levels were 30% lower in human cardiac muscle biopsies from patients with HL and/or type 2 diabetes mellitus, whereas GLUT4 mRNA levels were unchanged. PPARgamma mRNA levels were 30-50% lower in patients with HL and/or diabetes mellitus type 2 than in controls. Reporter studies in H9C2 cardiomyotubes showed that HL in vitro, induced by high levels of arachidonic (AA) stearic, linoleic, and oleic acids (24 h, 200 mum) repressed transcription from the GLUT4 promoter; AA also repressed transcription from the PPARgamma1 and PPARgamma2 promoters. Co-expression of PPARgamma2 repressed GLUT4 promoter activity, and the addition of AA further enhanced this effect. 5'-Deletion analysis revealed three GLUT4 promoter regions that accounted for AA-mediated effects: two repression-mediating sequences at -443/-423 bp and -222/-197 bp, the deletion of either or both of which led to a partial derepression of promoter activity, and a third derepression-mediating sequence at -612/-587 bp that was required for sustaining this derepression effect. Electromobility shift assay further shows that AA enhanced binding to two of the three regions of cardiac nuclear protein(s), the nature of which is still unknown. We propose that HL, exhibited as a high free fatty acid level, modulates GLUT4 gene expression in cardiac muscle via a complex mechanism that includes: (a) binding of AA mediator proteins to three newly identified response elements on the GLUT4 promoter gene and (b) repression of GLUT4 and the PPARgamma genes by AA.
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Affiliation(s)
- Michal Armoni
- Institute of Endocrinology, Diabetes and Metabolism, Rambam Medical Center and B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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13
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Leloup C, Magnan C, Alquier T, Mistry S, Offer G, Arnaud E, Kassis N, Ktorza A, Pénicaud L. Intrauterine hyperglycemia increases insulin binding sites but not glucose transporter expression in discrete brain areas in term rat fetuses. Pediatr Res 2004; 56:263-7. [PMID: 15181191 DOI: 10.1203/01.pdr.0000132853.35660.27] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Diabetic pregnancy results in several metabolic and hormonal disorders, both in the embryo and the fetus of different species, including humans. Insulin is a potent modulator of brain development and is suggested to promote the differentiation and maturation of hypothalamic or related extrahypothalamic structures, which are directly involved in neural inputs to the pancreas. Because these structures are known to be specifically responsive both to insulin and glucose, we examined the effects of 48-h hyperglycemic clamps in unrestrained pregnant rats on insulin binding and glucose transporter expression in hypothalamic and extrahypothalamic-related areas of their fetal offspring. The main result was an increase in insulin binding in the ventromedial hypothalamic nucleus (VMH), the arcuate nucleus (AN), and the lateral hypothalamus (LH), and in the nucleus of the tractus solitarius (NTS) for extrahypothalamic areas (+30% in the VMH, +37% in the AN, +25.8% in the LH, and +37.3% in the NTS). The deleterious effect of brain hyperinsulinism during the late gestational stage does not seem to act through glucose transporter (GLUT) expression, inasmuch as no relationship between GLUT level and hyperinsulinism in brain areas could be observed. The specific increase in insulin binding in areas involved in the nervous control of metabolism could be a factor in the increased glucose intolerance and impairment of insulin secretion that was previously observed in the adult rats from hyperglycemic mothers.
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Affiliation(s)
- Corinne Leloup
- CNRS UMR 5018-UPS, CHU de Rangueil, 1 Ave Jean Poulhès, 31 403 Toulouse cedex, France.
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14
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James DJ, Cairns F, Salt IP, Murphy GJ, Dominiczak AF, Connell JM, Gould GW. Skeletal muscle of stroke-prone spontaneously hypertensive rats exhibits reduced insulin-stimulated glucose transport and elevated levels of caveolin and flotillin. Diabetes 2001; 50:2148-56. [PMID: 11522683 DOI: 10.2337/diabetes.50.9.2148] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Insulin resistance is of major pathogenic importance in several common human disorders, but the underlying mechanisms are unknown. The stroke-prone spontaneously hypertensive (SHRSP) rat is a model of human insulin resistance and is characterized by reduced insulin-mediated glucose disposal and defective fatty acid metabolism in isolated adipocytes (Collison et al. [Diabetes 49:2222-2226, 2000]). In this study, we have examined skeletal muscle and cultured skeletal muscle myoblasts for defects in insulin action in the male SHRSP rat model compared with the normotensive, insulin-sensitive control strain, Wistar-Kyoto (WKY). We show that skeletal muscle from SHRSP animals exhibits a marked decrease in insulin-stimulated glucose transport compared with WKY animals (fold increase in response to insulin: 1.4 +/- 0.15 in SHRSP, 2.29 +/- 0.22 in WKY; n = 4, P = 0.02), but the stimulation of glucose transport in response to activation of AMP-activated protein kinase was similar between the two strains. Similar reductions in insulin-stimulated glucose transport were also evident in myoblast cultures from SHRSP compared with WKY cultures. These differences were not accounted for by a reduction in cellular GLUT4 content. Moreover, analysis of the levels and subcellular distribution of insulin receptor substrates 1 and 2, the p85alpha subunit of phosphatidylinositol 3'-kinase, and protein kinase B (PKB)/cAKT in skeletal muscle did not identify any differences between the two strains; the insulin-dependent activation of PKB/cAKT was not different between the two strains. However, the total cellular levels of caveolin and flotillin, proteins implicated in insulin signal transduction/compartmentalization, were markedly elevated in skeletal muscles from SHRSP compared with WKY animals. Increased cellular levels of the soluble N-ethylmaleimide attachment protein receptor (SNARE) proteins syntaxin 4 and vesicle-associated membrane protein (VAMP)-2 were also observed in the insulin-resistant SHRSP strain. Taken together, these data suggest that the insulin resistance observed in the SHRSP is manifest at the level of skeletal muscle, that muscle cell glucose transport exhibits a blunted response to insulin but unchanged responses to activation of AMP-activated protein kinase, that alterations in key molecules in both GLUT4 trafficking and insulin signal compartmentalization may underlie these defects in insulin action, and that the insulin resistance of these muscles appears to be of genetic origin rather than a paracrine or autocrine effect, since the insulin resistance is also observed in cultured myoblasts over several passages.
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Affiliation(s)
- D J James
- Division of Biochemistry and Molecular Biology, University of Glasgow, Glasgow, Scotland, UK
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15
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Seatter MJ, Gould GW. The mammalian facilitative glucose transporter (GLUT) family. PHARMACEUTICAL BIOTECHNOLOGY 2000; 12:201-28. [PMID: 10742976 DOI: 10.1007/0-306-46812-3_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- M J Seatter
- Division of Biochemistry and Molecular Biology, University of Glasgow, Scotland
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16
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Cheung A, Kusari J, Jansen D, Bandyopadhyay D, Kusari A, Bryer-Ash M. Marked impairment of protein tyrosine phosphatase 1B activity in adipose tissue of obese subjects with and without type 2 diabetes mellitus. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1999; 134:115-23. [PMID: 10444024 DOI: 10.1016/s0022-2143(99)90115-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Protein tyrosine phosphatases (PTPs) are required for the dephosphorylation of the insulin receptor (IR) and its initial cellular substrates, and it has recently been reported that PTP-1B may play a role in the pathogenesis of insulin resistance in obesity and type 2 diabetes mellitus (DM). We therefore determined the amount and activity of PTP-1B in abdominal adipose tissue obtained from lean nondiabetic subjects (lean control (LC)), obese nondiabetic subjects (obese control (OC)), and subjects with both type 2 DM (DM2) and obesity (obese diabetic (OD)). PTP-1B protein levels were 3-fold higher in OC than in LC (1444 +/- 195 U vs 500 +/- 146 U (mean +/- SEM), P < .015), while OD exhibited a 5.5-fold increase (2728 +/- 286 U, P < .01). PTP activity was assayed by measuring the dephosphorylating activity toward a phosphorus 32-labeled synthetic dodecapeptide. In contrast to the increased PTP-1B protein levels, PTP-1B activity per unit of PTP-1B protein was markedly reduced, by 71% and 88% in OC and OD, respectively. Non-PTP-1B tyrosine phosphatase activity was comparable in all three groups. Similar results were obtained when PTP-1B activity was measured against intact human IR. A significant correlation was found between body mass index (BMI) and PTP-1B level (r = 0.672, P < .02), whereas BMI and PTP-1B activity per unit of PTP-1B showed a strong inverse correlation (r = -0.801, P < .002). These data suggest that the insulin resistance of obesity and DM2 is characterized by the increased expression of a catalytically impaired PTP-1B in adipose tissue and that impaired PTP-1B activity may be pathogenic for insulin resistance in these conditions.
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Affiliation(s)
- A Cheung
- Department of Medicine, University of Tennessee College of Medicine, Memphis, USA
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17
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Stenbit AE, Tsao TS, Li J, Burcelin R, Geenen DL, Factor SM, Houseknecht K, Katz EB, Charron MJ. GLUT4 heterozygous knockout mice develop muscle insulin resistance and diabetes. Nat Med 1997; 3:1096-101. [PMID: 9334720 DOI: 10.1038/nm1097-1096] [Citation(s) in RCA: 246] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
GLUT4, the insulin-responsive glucose transporter, plays an important role in postprandial glucose disposal. Altered GLUT4 activity is suggested to be one of the factors responsible for decreased glucose uptake in muscle and adipose tissue in obesity and diabetes. To assess the effect of GLUT4 expression on whole-body glucose homeostasis, we disrupted the murine GLUT4 gene by homologous recombination. Male mice heterozygous for the mutation (GLUT4 +/-) exhibited a decrease in GLUT4 expression in adipose tissue and skeletal muscle. This decrease in GLUT4 expression did not result in obesity but led to increased serum glucose and insulin, reduced muscle glucose uptake, hypertension, and diabetic histopathologies in the heart and liver similar to those of humans with non-insulin-dependent diabetes mellitus (NIDDM). The male GLUT4 +/- mice represent a good model for studying the development of NIDDM without the complications associated with obesity.
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Affiliation(s)
- A E Stenbit
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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18
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McCall AL, van Bueren AM, Huang L, Stenbit A, Celnik E, Charron MJ. Forebrain endothelium expresses GLUT4, the insulin-responsive glucose transporter. Brain Res 1997; 744:318-26. [PMID: 9027391 DOI: 10.1016/s0006-8993(96)01122-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The presence of GLUT4, the insulin-responsive glucose transporter, in microvascular endothelium and the responsiveness of glucose transport at the blood-brain barrier to insulin have been matters of controversy. To address these issues, we examined GLUT4 mRNA and protein expression in isolated brain microvessels and in cultured calf vascular cells derived from brain microvessels and aorta. We report here that GLUT4 mRNA can be detected in rat forebrain and its microvasculature using high stringency hybridization of poly(A)+ RNA isolated from these sources. This mRNA is identical to that found in adipose cells from rat. Immunoblot analysis of isolate brain microvessels reveals that GLUT4 protein is also present. Peptide preadsorption studies and absence of our antibody reaction to human red cells suggest these findings are specific. Immunohistochemical staining of cultured calf vascular cells reveals that GLUT4 is expressed in brain endothelial cells but not pericytes, nor in aortic endothelium or smooth muscle cells. The sensitivity of the methods required to detect GLUT4 in brain and comparison to its abundance in low density microsomes from rat adipose cells indicate that GLUT4 is expressed in relatively low abundance in brain microvascular endothelium. No significant differences are observed in steady state levels of GLUT4 mRNA in brain from streptozotocin diabetic compared to control rats. This last finding supports the concept of tissue-specific regulation of GLUT4. We conclude that brain microvascular endothelium specifically expressed GLUT4 while other vascular cells do not.
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Affiliation(s)
- A L McCall
- Diabetes Program, Portland VA Medical Center, OR 97201, USA.
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19
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Abstract
Although muscle is thought to be a primary assimilator of glucose, adipose may provide a substantial amount of substrate for gluconeogenesis, even in the fed state.
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Affiliation(s)
- S C Frost
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville 32610, USA
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20
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Quon MJ. Advances in kinetic analysis of insulin-stimulated GLUT-4 translocation in adipose cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:E144-50. [PMID: 8304439 DOI: 10.1152/ajpendo.1994.266.1.e144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
GLUT-4 is the major insulin-sensitive glucose transporter in muscle and adipose tissue. Regulation of GLUT-4 is an important component of whole body glucose homeostasis. Abnormalities in the regulation of insulin-stimulated reversible translocation of glucose transporters have been observed in various pathological states, including diabetes. Recently, the development of specific photolabels for glucose transporters and the availability of antibodies against the various transporter isoforms have presented the opportunity for detailed kinetic analysis of GLUT-4 regulation. A kinetic analysis of some of the most recent data is presented to demonstrate how this approach can advance the understanding of GLUT-4 regulation. Some areas in which the currently available data limit the ability to resolve certain mechanistic questions are noted. Using a two-compartment model, we show that the mechanism of insulin-stimulated GLUT-4 translocation is likely to involve a large increase in the exocytosis rate of GLUT-4 with a minimal decrease in the endocytosis rate. Mathematical models based on these kinetic analyses are helpful for testing hypotheses and designing experiments to elucidate the molecular and cellular mechanisms of GLUT-4 regulation under normal and pathological conditions. This type of approach may be useful for evaluating the contribution of GLUT-4 regulation to the pathogenesis of diabetes.
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Affiliation(s)
- M J Quon
- Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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21
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Rosenbaum D, Haber RS, Dunaif A. Insulin resistance in polycystic ovary syndrome: decreased expression of GLUT-4 glucose transporters in adipocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 264:E197-202. [PMID: 8447386 DOI: 10.1152/ajpendo.1993.264.2.e197] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have found that women with polycystic ovary syndrome (PCOS) have decreased sensitivity and responsiveness to insulin. The present study was performed to determine whether this impaired insulin responsiveness was associated with diminished GLUT-4 glucose transporter content in adipocytes. Insulin-stimulated glucose transport and GLUT-4 abundance were measured in abdominal adipocytes from obese (n = 9) and lean (n = 7) PCOS as well as obese (n = 8) and lean (n = 8) control women matched for age and weight. No woman had impaired glucose tolerance. The maximal insulin-stimulated increment in adipocyte glucose transport was independently decreased by obesity and by PCOS. As expected, GLUT-4 content in adipocyte membranes was decreased in obesity (by 40%, P < or = 0.01). GLUT-4 content was also significantly decreased in PCOS (by 36%, P < or = 0.01), independent of obesity. There was a highly significant correlation (R = 0.66, P < = 0.001) between GLUT-4 content and insulin-stimulated glucose transport in adipocytes from individual women across the study population. We conclude that the diminished adipocyte insulin responsiveness in PCOS is associated with decreased GLUT-4 abundance. This represents a newly recognized phenotypic feature of the insulin resistance of PCOS. Moreover, in human adipocytes, GLUT-4 abundance is highly correlated with insulin responsiveness.
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Affiliation(s)
- D Rosenbaum
- Department of Medicine, Mount Sinai School of Medicine, New York, New York 10029
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22
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Hundal HS, Klip A. Regulation of glucose transporters and the Na/K-ATPase by insulin in skeletal muscle. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 334:63-78. [PMID: 8249696 DOI: 10.1007/978-1-4615-2910-1_5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- H S Hundal
- Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
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23
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Hamman RF. Genetic and environmental determinants of non-insulin-dependent diabetes mellitus (NIDDM). DIABETES/METABOLISM REVIEWS 1992; 8:287-338. [PMID: 1307522 DOI: 10.1002/dmr.5610080402] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- R F Hamman
- University of Colorado School of Medicine, Department of Preventive Medicine and Biometrics, Denver 80262
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24
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Shepherd PR, Gould GW, Colville CA, McCoid SC, Gibbs EM, Kahn BB. Distribution of GLUT3 glucose transporter protein in human tissues. Biochem Biophys Res Commun 1992; 188:149-54. [PMID: 1417839 DOI: 10.1016/0006-291x(92)92362-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To investigate the tissue distribution of the GLUT3 glucose transporter isoform in human tissue we produced affinity purified antibodies to the COOH terminus of the human GLUT3. Both antibodies recognize a specific GLUT3 band in oocytes injected with GLUT3 mRNA but not in those injected with H2O or GLUT1, 2, 4, 5 mRNA. This immunoreactive band in GLUT3 injected oocytes is photolabelled by cytochalasin-B in the presence of L- but not D-glucose indicating that it is a glucose transporter. A high cross reactivity between the human GLUT3 antibodies and a 43 kDa cytoskeletal actin band was identified in all oocyte lysates and many human tissues. However, the specific GLUT3 band could be distinguished from the actin band by carbonate treatment which preferentially solubilized the actin band. Using these antibodies we show that GLUT3 is present as a 45-48 kDa protein in human brain with lower levels detectable in heart, placenta, liver and a barely detectable level in kidney. No GLUT3 was detected in membranes from any of 3 skeletal muscle groups investigated. We conclude that a major role of GLUT3 in humans is as the brain neuronal glucose transporter.
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Affiliation(s)
- P R Shepherd
- Charles A. Dana Research Institute, Beth Israel Hospital, Boston, MA 02215
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