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Hulett NA, Scalzo RL, Reusch JEB. Glucose Uptake by Skeletal Muscle within the Contexts of Type 2 Diabetes and Exercise: An Integrated Approach. Nutrients 2022; 14:nu14030647. [PMID: 35277006 PMCID: PMC8839578 DOI: 10.3390/nu14030647] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023] Open
Abstract
Type 2 diabetes continues to negatively impact the health of millions. The inability to respond to insulin to clear blood glucose (insulin resistance) is a key pathogenic driver of the disease. Skeletal muscle is the primary tissue for maintaining glucose homeostasis through glucose uptake via insulin-dependent and -independent mechanisms. Skeletal muscle is also responsive to exercise-meditated glucose transport, and as such, exercise is a cornerstone for glucose management in people with type 2 diabetes. Skeletal muscle glucose uptake requires a concert of events. First, the glucose-rich blood must be transported to the skeletal muscle. Next, the glucose must traverse the endothelium, extracellular matrix, and skeletal muscle membrane. Lastly, intracellular metabolic processes must be activated to maintain the diffusion gradient to facilitate glucose transport into the cell. This review aims to examine the physiology at each of these steps in healthy individuals, analyze the dysregulation affecting these pathways associated with type 2 diabetes, and describe the mechanisms by which exercise acts to increase glucose uptake.
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Affiliation(s)
- Nicholas A. Hulett
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
| | - Rebecca L. Scalzo
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Center for Women’s Health Research, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA
| | - Jane E. B. Reusch
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Center for Women’s Health Research, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA
- Correspondence:
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2
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Chen X, Zhao Y, Gao Y, Qi Y, Du J. Outcomes in hepatocellular carcinoma patients undergoing sorafenib treatment: toxicities, cellular oxidative stress, treatment adherence, and quality of life: Erratum. Anticancer Drugs 2021; 32:345-364. [PMID: 33417326 DOI: 10.1097/cad.0000000000001029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Xiaotong Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou
| | - Yunshuo Zhao
- School of Life Sciences, Zhengzhou University, Zhengzhou
| | - Yanfeng Gao
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Yuanming Qi
- School of Life Sciences, Zhengzhou University, Zhengzhou
| | - Jiangfeng Du
- School of Life Sciences, Zhengzhou University, Zhengzhou
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3
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Glucose transporters in adipose tissue, liver, and skeletal muscle in metabolic health and disease. Pflugers Arch 2020; 472:1273-1298. [PMID: 32591906 PMCID: PMC7462924 DOI: 10.1007/s00424-020-02417-x] [Citation(s) in RCA: 172] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022]
Abstract
A family of facilitative glucose transporters (GLUTs) is involved in regulating tissue-specific glucose uptake and metabolism in the liver, skeletal muscle, and adipose tissue to ensure homeostatic control of blood glucose levels. Reduced glucose transport activity results in aberrant use of energy substrates and is associated with insulin resistance and type 2 diabetes. It is well established that GLUT2, the main regulator of hepatic hexose flux, and GLUT4, the workhorse in insulin- and contraction-stimulated glucose uptake in skeletal muscle, are critical contributors in the control of whole-body glycemia. However, the molecular mechanism how insulin controls glucose transport across membranes and its relation to impaired glycemic control in type 2 diabetes remains not sufficiently understood. An array of circulating metabolites and hormone-like molecules and potential supplementary glucose transporters play roles in fine-tuning glucose flux between the different organs in response to an altered energy demand.
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4
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Regulation of Skeletal Muscle Glucose Transport and Glucose Metabolism by Exercise Training. Nutrients 2019; 11:nu11102432. [PMID: 31614762 PMCID: PMC6835691 DOI: 10.3390/nu11102432] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 09/30/2019] [Accepted: 10/08/2019] [Indexed: 12/22/2022] Open
Abstract
Aerobic exercise training and resistance exercise training are both well-known for their ability to improve human health; especially in individuals with type 2 diabetes. However, there are critical differences between these two main forms of exercise training and the adaptations that they induce in the body that may account for their beneficial effects. This article reviews the literature and highlights key gaps in our current understanding of the effects of aerobic and resistance exercise training on the regulation of systemic glucose homeostasis, skeletal muscle glucose transport and skeletal muscle glucose metabolism.
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5
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Carreño D, Corro N, Torres-Estay V, Véliz LP, Jaimovich R, Cisternas P, San Francisco IF, Sotomayor PC, Tanasova M, Inestrosa NC, Godoy AS. Fructose and prostate cancer: toward an integrated view of cancer cell metabolism. Prostate Cancer Prostatic Dis 2018; 22:49-58. [PMID: 30104655 DOI: 10.1038/s41391-018-0072-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/13/2018] [Accepted: 06/29/2018] [Indexed: 01/07/2023]
Abstract
Activation of glucose transporter-1 (Glut-1) gene expression is a molecular feature of cancer cells that increases glucose uptake and metabolism. Increased glucose uptake is the basis for the clinical localization of primary tumors using positron emission tomography (PET) and 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) as a radiotracer. However, previous studies have demonstrated that a considerable number of cancers, which include prostate cancer (CaP), express low to undetectable levels of Glut-1 and that FDG-PET has limited clinical applicability in CaP. This observation could be explained by a low metabolic activity of CaP cells that may be overcome using different hexoses, such as fructose, as the preferred energy source. However, these hypotheses have not been examined critically in CaP. This review article summarizes what is currently known about transport and metabolism of hexoses, and more specifically fructose, in CaP and provides experimental evidences indicating that CaP cells may have increased capacity to transport and metabolize fructose in vitro and in vivo. Moreover, this review highlights recent findings that allow better understanding of how metabolism of fructose may regulate cancer cell proliferation and how fructose uptake and metabolism, through the de novo lipogenesis pathway, may provide new opportunities for CaP early diagnosis, staging, and treatment.
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Affiliation(s)
- Daniela Carreño
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Néstor Corro
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Loreto P Véliz
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Pedro Cisternas
- Centro de Envejecimiento y Regeneración (CARE), Department of Cell Biology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Paula C Sotomayor
- Center for Integrative Medicine and Innovative Science, Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Marina Tanasova
- Department of Chemistry, Michigan Technological University, Houghton, MI, 49931, USA
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Department of Cell Biology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alejandro S Godoy
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, 14263, USA.
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6
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Welch KC, Myrka AM, Ali RS, Dick MF. The Metabolic Flexibility of Hovering Vertebrate Nectarivores. Physiology (Bethesda) 2018; 33:127-137. [DOI: 10.1152/physiol.00001.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Foraging hummingbirds and nectar bats oxidize both glucose and fructose from nectar at exceptionally high rates. Rapid sugar flux is made possible by adaptations to digestive, cardiovascular, and metabolic physiology affecting shared and distinct pathways for the processing of each sugar. Still, how these animals partition and regulate the metabolism of each sugar and whether this occurs differently between hummingbirds and bats remain unclear.
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Affiliation(s)
- Kenneth C. Welch
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Center for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Alexander M. Myrka
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Raafay Syed Ali
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Morag F. Dick
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
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7
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Jegatheesan P, De Bandt JP. Fructose and NAFLD: The Multifaceted Aspects of Fructose Metabolism. Nutrients 2017; 9:nu9030230. [PMID: 28273805 PMCID: PMC5372893 DOI: 10.3390/nu9030230] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 02/24/2017] [Indexed: 12/16/2022] Open
Abstract
Among various factors, such as an unhealthy diet or a sedentarity lifestyle, excessive fructose consumption is known to favor nonalcoholic fatty liver disease (NAFLD), as fructose is both a substrate and an inducer of hepatic de novo lipogenesis. The present review presents some well-established mechanisms and new clues to better understand the pathophysiology of fructose-induced NAFLD. Beyond its lipogenic effect, fructose intake is also at the onset of hepatic inflammation and cellular stress, such as oxidative and endoplasmic stress, that are key factors contributing to the progression of simple steatosis to nonalcoholic steatohepatitis (NASH). Beyond its hepatic effects, this carbohydrate may exert direct and indirect effects at the peripheral level. Excessive fructose consumption is associated, for example, with the release by the liver of several key mediators leading to alterations in the communication between the liver and the gut, muscles, and adipose tissue and to disease aggravation. These multifaceted aspects of fructose properties are in part specific to fructose, but are also shared in part with sucrose and glucose present in energy–dense beverages and foods. All these aspects must be taken into account in the development of new therapeutic strategies and thereby to better prevent NAFLD.
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Affiliation(s)
- Prasanthi Jegatheesan
- Department of Physiology, University of Lausanne, CH-1005 Lausanne, Switzerland.
- EA4466, Faculty of Pharmacy, Paris Descartes University, Sorbonne Paris Cité, 75006 Paris, France.
| | - Jean-Pascal De Bandt
- EA4466, Faculty of Pharmacy, Paris Descartes University, Sorbonne Paris Cité, 75006 Paris, France.
- Clinical Chemistry Department, Hôpitaux Universitaires Paris Centre, Assistance Publique-Hôpitaux de Paris, 75679 Paris, France.
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8
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Barron CC, Bilan PJ, Tsakiridis T, Tsiani E. Facilitative glucose transporters: Implications for cancer detection, prognosis and treatment. Metabolism 2016; 65:124-39. [PMID: 26773935 DOI: 10.1016/j.metabol.2015.10.007] [Citation(s) in RCA: 257] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/22/2015] [Accepted: 10/01/2015] [Indexed: 12/11/2022]
Abstract
It is long recognized that cancer cells display increased glucose uptake and metabolism. In a rate-limiting step for glucose metabolism, the glucose transporter (GLUT) proteins facilitate glucose uptake across the plasma membrane. Fourteen members of the GLUT protein family have been identified in humans. This review describes the major characteristics of each member of the GLUT family and highlights evidence of abnormal expression in tumors and cancer cells. The regulation of GLUTs by key proliferation and pro-survival pathways including the phosphatidylinositol 3-kinase (PI3K)-Akt, hypoxia-inducible factor-1 (HIF-1), Ras, c-Myc and p53 pathways is discussed. The clinical utility of GLUT expression in cancer has been recognized and evidence regarding the use of GLUTs as prognostic or predictive biomarkers is presented. GLUTs represent attractive targets for cancer therapy and this review summarizes recent studies in which GLUT1, GLUT3, GLUT5 and others are inhibited to decrease cancer growth.
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Affiliation(s)
- Carly C Barron
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Philip J Bilan
- Program in Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Theodoros Tsakiridis
- Department of Oncology, and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Evangelia Tsiani
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
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9
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Fructose–Glucose Composite Carbohydrates and Endurance Performance: Critical Review and Future Perspectives. Sports Med 2015; 45:1561-76. [DOI: 10.1007/s40279-015-0381-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Jaiswal N, Maurya CK, Pandey J, Rai AK, Tamrakar AK. Fructose-induced ROS generation impairs glucose utilization in L6 skeletal muscle cells. Free Radic Res 2015; 49:1055-68. [PMID: 25968943 DOI: 10.3109/10715762.2015.1031662] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High fructose consumption has implicated in insulin resistance and metabolic syndrome. Fructose is a highly lipogenic sugar that has intense metabolic effects in liver. Recent evidences suggest that fructose exposure to other tissues has substantial and profound metabolic consequences predisposing toward chronic conditions such as type 2 diabetes. Since skeletal muscle is the major site for glucose utilization, in the present study we define the effects of fructose exposure on glucose utilization in skeletal muscle cells. Upon fructose exposure, the L6 skeletal muscle cells displayed diminished glucose uptake, glucose transporter type 4 (GLUT4) translocation, and impaired insulin signaling. The exposure to fructose elevated reactive oxygen species (ROS) production in L6 myotubes, accompanied by activation of the stress/inflammation markers c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK1/2), and degradation of inhibitor of NF-κB (IκBα). We found that fructose caused impairment of glucose utilization and insulin signaling through ROS-mediated activation of JNK and ERK1/2 pathways, which was prevented in the presence of antioxidants. In conclusion, our data demonstrate that exposure to fructose induces cell-autonomous oxidative response through ROS production leading to impaired insulin signaling and attenuated glucose utilization in skeletal muscle cells.
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Affiliation(s)
- N Jaiswal
- Division of Biochemistry, CSIR-Central Drug Research Institute , Lucknow, Uttar Pradesh , India
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11
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Fernández-Novell JM, Ramió-Lluch L, Orozco A, Gómez-Foix AM, Guinovart JJ, Rodríguez-Gil JE. Glucose and fructose have sugar-specific effects in both liver and skeletal muscle in vivo: a role for liver fructokinase. PLoS One 2014; 9:e109726. [PMID: 25330076 PMCID: PMC4201455 DOI: 10.1371/journal.pone.0109726] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/04/2014] [Indexed: 11/18/2022] Open
Abstract
We examined glucose and fructose effects on serine phosphorylation levels of a range of proteins in rat liver and muscle cells. For this, healthy adult rats were subjected to either oral glucose or fructose loads. A mini-array system was utilized to determine serine phosphorylation levels of liver and skeletal muscle proteins. A glucose oral load of 125 mg/100 g body weight (G 1/2) did not induce changes in phosphorylated serines of the proteins studied. Loading with 250 mg/100 g body weight of fructose (Fr), which induced similar glycemia levels as G 1/2, significantly increased serine phosphorylation of liver cyclin D3, PI3 kinase/p85, ERK-2, PTP2 and clusterin. The G 1/2 increased serine levels of the skeletal muscle proteins cyclin H, Cdk2, IRAK, total PKC, PTP1B, c-Raf 1, Ras and the β-subunit of the insulin receptor. The Fr induced a significant increase only in muscle serine phosphorylation of PI3 kinase/p85. The incubation of isolated rat hepatocytes with 10 mM glucose for 5 min significantly increased serine phosphorylation of 31 proteins. In contrast, incubation with 10 mM fructose produced less intense effects. Incubation with 10 mM glucose plus 75 µM fructose counteracted the effects of the incubation with glucose alone, except those on Raf-1 and Ras. Less marked effects were detected in cultured muscle cells incubated with 10 mM glucose or 10 mM glucose plus 75 µM fructose. Our results suggest that glucose and fructose act as specific functional modulators through a general mechanism that involves liver-generated signals, like micromolar fructosemia, which would inform peripheral tissues of the presence of either glucose- or fructose-derived metabolites.
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Affiliation(s)
| | - Laura Ramió-Lluch
- Dept. Animal Medicine and Surgery, Autonomous University of Barcelona, Bellaterra, Spain
| | - Anna Orozco
- Dept. Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Anna M. Gómez-Foix
- Dept. Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Joan J. Guinovart
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
- Institute for Research in Biomedicine, Barcelona Science Park, Barcelona, Spain
| | - Joan E. Rodríguez-Gil
- Dept. Animal Medicine and Surgery, Autonomous University of Barcelona, Bellaterra, Spain
- * E-mail:
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12
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Gaster M. Fibre Type Dependent Expression of Glucose Transporters in Human Skeletal Muscles. APMIS 2008. [DOI: 10.1111/j.1600-0463.2007.apmv115s121.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Abstract
Under normal physiological conditions, the brain utilizes only a small number of carbon sources for energy. Recently, there is growing molecular and biochemical evidence that other carbon sources, including fructose, may play a role in neuro-energetics. Fructose is the number one commercial sweetener in Western civilization with large amounts of fructose being toxic, yet fructose metabolism remains relatively poorly characterized. Fructose is purportedly metabolized via either of two pathways, the fructose-1-phosphate pathway and/or the fructose-6-phosphate pathway. Many early metabolic studies could not clearly discriminate which of these two pathways predominates, nor could they distinguish which cell types in various tissues are capable of fructose metabolism. In addition, the lack of good physiological models, the diet-induced changes in gene expression in many tissues, the involvement of multiple genes in multiple pathways involved in fructose metabolism, and the lack of characterization of some genes involved in fructose metabolism have complicated our understanding of the physiological role of fructose in neuro-energetics. A recent neuro-metabolism study of the cerebellum demonstrated fructose metabolism and co-expression of the genes specific for the fructose 1-phosphate pathway, GLUT5 (glut5) and ketohexokinase (khk), in Purkinje cells suggesting this as an active pathway in specific neurons? Meanwhile, concern over the rapid increase in dietary fructose, particularly among children, has increased awareness about how fructose is metabolized in vivo and what effects a high fructose diet might have. In this regard, establishment of cellular and molecular studies and physiological characterization of the important and/or deleterious roles fructose plays in the brain is critical. This review will discuss the status of fructose metabolism in the brain with special reference to the cerebellum and the physiological roles of the different pathways.
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Affiliation(s)
- Vincent A Funari
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
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14
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Affiliation(s)
- Michael Gaster
- Institute of Pathology and Department of Endocrinology, Odense University Hospital, 5000 Odense C
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15
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Juel C. Training-induced changes in membrane transport proteins of human skeletal muscle. Eur J Appl Physiol 2006; 96:627-35. [PMID: 16456673 DOI: 10.1007/s00421-006-0140-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2006] [Indexed: 11/29/2022]
Abstract
Training improves human physical performance by inducing structural and cardiovascular changes, metabolic changes, and changes in the density of membrane transport proteins. This review focuses on the training-induced changes in proteins involved in sarcolemmal membrane transport. It is concluded that the same type of training affects many transport proteins, suggesting that all transport proteins increase with training, and that both sprint and endurance training in humans increase the density of most membrane transport proteins. There seems to be an upper limit for these changes: intense training for 6-8 weeks substantially increases the density of membrane proteins, whereas years of training (as performed by athletes) have no further effect. Studies suggest that training-induced changes at the protein level are important functionally. The underlying factors responsible for these changes in transport proteins might include changes in substrate concentration, but the existence of "exercise factors" mediating these responses is more likely. Exercise factors might include Ca(2+), mitogen-activated protein kinases, adenosine monophosphate kinases, other kinases, or interleukin-6. Although the magnitudes of training-induced changes have been investigated at the protein level, the underlying signal mechanisms have not been fully described.
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Affiliation(s)
- Carsten Juel
- Copenhagen Muscle Research Centre, Institute of Molecular Biology and Physiology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100 Copenhagen, Denmark.
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16
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Abstract
The question is no longer whether diet and exercise can benefit the individual with type 2 diabetes. Rather, the type and duration of exercise the magnitude of the effects on glycemic control, insulin sensitivity, and on risk factors for cardiovascular disease must be considered in determining the feasibility and acceptability of an intervention program. It is now clear that regular physical exercise is important in both the prevention and treatment of type 2 diabetes. The benefits of exercise are many and include increased energy expenditure, which, combined with dietary restriction, leads to decreased body fat, increased insulin sensitivity, improved long-term glycemic control, improved lipid profiles, lower blood pressure, and increased cardiovascular fitness. Persons with type 2 diabetes often find it difficult to exercise and are at increased risk for injury or exacerbation of underlying diseases or diabetic complications. Therefore, before starting an exercise program, all patients with type 2 diabetes should have a complete history and physical examination, with particular attention to evaluation of cardiovascular disease, medications that may affect glycemic control during or after exercise, and diabetic complications including retinopathy, nephropathy, and neuropathy. Exercise programs should be designed to start slowly, build up gradually, and emphasize moderately intense exercise performed at least three times a week and preferably five to seven times a week for best results.
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Affiliation(s)
- O Hamdy
- Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
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