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Zhang C, Gu L, Xie H, Liu Y, Huang P, Zhang J, Luo D, Zhang J. Glucose transport, transporters and metabolism in diabetic retinopathy. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166995. [PMID: 38142757 DOI: 10.1016/j.bbadis.2023.166995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/02/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Diabetic retinopathy (DR) is the most common reason for blindness in working-age individuals globally. Prolonged high blood glucose is a main causative factor for DR development, and glucose transport is prerequisite for the disturbances in DR caused by hyperglycemia. Glucose transport is mediated by its transporters, including the facilitated transporters (glucose transporter, GLUTs), the "active" glucose transporters (sodium-dependent glucose transporters, SGLTs), and the SLC50 family of uniporters (sugars will eventually be exported transporters, SWEETs). Glucose transport across the blood-retinal barrier (BRB) is crucial for nourishing the neuronal retina in the context of retinal physiology. This physiological process primarily relies on GLUTs and SGLTs, which mediate the glucose transportation across both the cell membrane of retinal capillary endothelial cells and the retinal pigment epithelium (RPE). Under diabetic conditions, increased accumulation of extracellular glucose enhances the retinal cellular glucose uptake and metabolism via both glycolysis and glycolytic side branches, which activates several biochemical pathways, including the protein kinase C (PKC), advanced glycation end-products (AGEs), polyol pathway and hexosamine biosynthetic pathway (HBP). These activated biochemical pathways further increase the production of reactive oxygen species (ROS), leading to oxidative stress and activation of Poly (ADP-ribose) polymerase (PARP). The activated PARP further affects all the cellular components in the retina, and finally resulting in microangiopathy, neurodegeneration and low-to-moderate grade inflammation in DR. This review aims to discuss the changes of glucose transport, glucose transporters, as well as its metabolism in DR, which influences the retinal neurovascular unit (NVU) and implies the possible therapeutic strategies for treating DR.
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Affiliation(s)
- Chaoyang Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Limin Gu
- Department of Ophthalmology, Shanghai Aier Eye Hospital, Shanghai, China.
| | - Hai Xie
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Yan Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Peirong Huang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Jingting Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Dawei Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
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Yang M, Chen Y, Vagionitis S, Körtvely E, Ueffing M, Schmachtenberg O, Hu Z, Jiao K, Paquet-Durand F. Expression of glucose transporter-2 in murine retina: Evidence for glucose transport from horizontal cells to photoreceptor synapses. J Neurochem 2021; 160:283-296. [PMID: 34726780 DOI: 10.1111/jnc.15533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/12/2021] [Accepted: 10/18/2021] [Indexed: 01/30/2023]
Abstract
The retina has the highest relative energy consumption of any tissue, depending on a steady supply of glucose from the bloodstream. Glucose uptake is mediated by specific transporters whose regulation and expression are critical for the pathogenesis of many diseases, including diabetes and diabetic retinopathy. Here, we used immunofluorescence to show that glucose transporter-2 (GLUT2) is expressed in horizontal cells of the mouse neuroretina in proximity to inner retinal capillaries. To study the function of GLUT2 in the murine retina, we used organotypic retinal explants, cultivated under entirely controlled, serum-free conditions and exposed them to streptozotocin, a cytotoxic drug transported exclusively by GLUT2. Contrary to our expectations, streptozotocin did not measurably affect horizontal cell viability, while it ablated rod and cone photoreceptors in a concentration-dependent manner. Staining for poly-ADP-ribose (PAR) indicated that the detrimental effect of streptozotocin on photoreceptors may be associated with DNA damage. The negative effect of streptozotocin on the viability of rod photoreceptors was counteracted by co-administration of either the inhibitor of connexin-formed hemi-channels meclofenamic acid or the blocker of clathrin-mediated endocytosis dynasore. Remarkably, cone photoreceptors were not protected from streptozotocin-induced degeneration by neither of the two drugs. Overall, these data suggest the existence of a GLUT2-dependent glucose transport shuttle, from horizontal cells into photoreceptor synapses. Moreover, our study points at different glucose uptake mechanisms in rod and cone photoreceptors.
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Affiliation(s)
- Ming Yang
- Affiliated Hospital of Yunnan University & 2nd People's Hospital of Yunnan Province, Kunming, China.,Yunnan Eye Institute & Key Laboratory of Yunnan Province, Kunming, China.,1st Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yiyi Chen
- Institute for Ophthalmic Research, Eberhard-Karls-Universität, Tübingen, Germany
| | - Stavros Vagionitis
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Elöd Körtvely
- Roche Pharma Research and Early Development, Immunology, Infectious Diseases and Ophthalmology (I2O), Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Marius Ueffing
- Institute for Ophthalmic Research, Eberhard-Karls-Universität, Tübingen, Germany
| | - Oliver Schmachtenberg
- CINV, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Zhulin Hu
- Affiliated Hospital of Yunnan University & 2nd People's Hospital of Yunnan Province, Kunming, China.,Yunnan Eye Institute & Key Laboratory of Yunnan Province, Kunming, China
| | - Kangwei Jiao
- Affiliated Hospital of Yunnan University & 2nd People's Hospital of Yunnan Province, Kunming, China.,Yunnan Eye Institute & Key Laboratory of Yunnan Province, Kunming, China
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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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Chen X, Qian Y, Wu S. The Warburg effect: evolving interpretations of an established concept. Free Radic Biol Med 2015; 79:253-63. [PMID: 25277420 PMCID: PMC4356994 DOI: 10.1016/j.freeradbiomed.2014.08.027] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 08/15/2014] [Accepted: 08/23/2014] [Indexed: 12/20/2022]
Abstract
Metabolic reprogramming and altered bioenergetics have emerged as hallmarks of cancer and an area of active basic and translational cancer research. Drastically upregulated glucose transport and metabolism in most cancers regardless of the oxygen supply, a phenomenon called the Warburg effect, is a major focuses of the research. Warburg speculated that cancer cells, due to defective mitochondrial oxidative phosphorylation (OXPHOS), switch to glycolysis for ATP synthesis, even in the presence of oxygen. Studies in the recent decade indicated that while glycolysis is indeed drastically upregulated in almost all cancer cells, mitochondrial respiration continues to operate normally at rates proportional to oxygen supply. There is no OXPHOS-to-glycolysis switch but rather upregulation of glycolysis. Furthermore, upregulated glycolysis appears to be for synthesis of biomass and reducing equivalents in addition to ATP production. The new finding that a significant amount of glycolytic intermediates is diverted to the pentose phosphate pathway (PPP) for production of NADPH has profound implications in how cancer cells use the Warburg effect to cope with reactive oxygen species (ROS) generation and oxidative stress, opening the door for anticancer interventions taking advantage of this. Recent findings in the Warburg effect and its relationship with ROS and oxidative stress controls will be reviewed. Cancer treatment strategies based on these new findings will be presented and discussed.
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Affiliation(s)
- Xiaozhuo Chen
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, USA; Department of Biomedical Sciences, Ohio University, Athens, OH 45701, USA; Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
| | - Yanrong Qian
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, USA; Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
| | - Shiyong Wu
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, USA; Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA.
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Qian Y, Wang X, Chen X. Inhibitors of glucose transport and glycolysis as novel anticancer therapeutics. World J Transl Med 2014; 3:37-57. [DOI: 10.5528/wjtm.v3.i2.37] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/25/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Metabolic reprogramming and altered energetics have become an emerging hallmark of cancer and an active area of basic, translational, and clinical cancer research in the recent decade. Development of effective anticancer therapeutics may depend on improved understanding of the altered cancer metabolism compared to that of normal cells. Changes in glucose transport and glycolysis, which are drastically upregulated in most cancers and termed the Warburg effect, are one of major focuses of this new research area. By taking advantage of the new knowledge and understanding of cancer’s mechanisms, numerous therapeutic agents have been developed to target proteins and enzymes involved in glucose transport and metabolism, with promising results in cancer cells, animal tumor models and even clinical trials. It has also been hypothesized that targeting a pathway or a process, such as glucose transport or glucose metabolism, rather than a specific protein or enzyme in a signaling pathway may be more effective. This is based on the observation that cancer somehow can always bypass the inhibition of a target drug by switching to a redundant or compensatory pathway. In addition, cancer cells have higher dependence on glucose. This review will provide background information on glucose transport and metabolism in cancer, and summarize new therapeutic developments in basic and translational research in these areas, with a focus on glucose transporter inhibitors and glycolysis inhibitors. The daunting challenges facing both basic and clinical researchers of the field are also presented and discussed.
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Ulloa V, García-Robles M, Martínez F, Salazar K, Reinicke K, Pérez F, Godoy DF, Godoy AS, Nualart F. Human choroid plexus papilloma cells efficiently transport glucose and vitamin C. J Neurochem 2013; 127:403-14. [DOI: 10.1111/jnc.12295] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/18/2013] [Accepted: 04/19/2013] [Indexed: 01/20/2023]
Affiliation(s)
- Viviana Ulloa
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
| | - María García-Robles
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
| | - Fernando Martínez
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
| | - Katterine Salazar
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
| | - Karin Reinicke
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
| | - Fernando Pérez
- Hospital Regional Guillermo Grant Benavente; Concepción Chile
| | - David F. Godoy
- Facultad de Medicina; Universidad de la Frontera; Temuco Chile
| | - Alejandro S. Godoy
- Departamento de Fisiología; Pontificia Universidad Católica de Chile; Santiago Chile
- Department of Urology; Roswell Park Cancer Institute; Buffalo New York USA
| | - Francisco Nualart
- Departamento de Biología Celular; Facultad de Ciencias Biológicas; Center for Advanced Microscopy; CMA BIO BIO; Universidad de Concepción; Concepción Chile
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Reinicke K, Sotomayor P, Cisterna P, Delgado C, Nualart F, Godoy A. Cellular distribution of Glut-1 and Glut-5 in benign and malignant human prostate tissue. J Cell Biochem 2012; 113:553-62. [PMID: 21938742 DOI: 10.1002/jcb.23379] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Over-expression of hexose transporters (Gluts), specifically Glut-1, is a common event in human malignancies. In prostate cancer (CaP), however, expression of Gluts has been characterized poorly. In this study, expression and distribution of Glut-1 and Glut-5 proteins were characterized using immunohistochemistry in 76 specimens of benign prostate, 10 specimens of high-grade intraepithelial neoplasia (HGPIN), and 28 specimens of CaP. In addition, mRNA expression of Glut-2, Glut-7, Glut-9, and Glut-11 was analyzed in a set of five specimens of benign prostate and CaP. In benign prostate, Glut-1 localized to the basal cells and to the basolateral membrane of secretory/luminal epithelial cells. Glut-5, however, localized to the apical membrane of secretory/luminal epithelial cells. In HGPIN, Glut-1 was immunohistochemically undetectable. Glut-5, however, localized to the apical membrane of the neoplastic epithelial cells. In CaP, Glut-1 and Glut-5, were immunohistochemically undetectable. However, over-expression of GLUT1 was observed in some specimens of highly proliferative intraductal CaP. Glut-7, Glut-9, and Glut-11 mRNAs were detected in benign prostate and CaP, however, only Glut-11 mRNA was consistently up-regulated in CaP compared to benign prostate. Low levels of expression of Glut-1 protein in the majority of CaP could explain, at least in part, the limited clinical applicability of positron emission tomography using 2-[18F]-fluoro-2-deoxy-D-glucose for imaging CaP. Moreover, expression of Glut-5 in HGPIN suggested that fructose could be utilized as potential metabolic substrate in HGPIN. Understanding the molecular mechanisms involved in regulation/dysregulation of Gluts in CaP could provide insight in the understanding of hexose metabolism in CaP.
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Affiliation(s)
- Karin Reinicke
- Departamento de Biología Celular, Universidad de Concepción, Concepción, Chile
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Godoy A, Ulloa V, Rodríguez F, Reinicke K, Yañez AJ, García MDLA, Medina RA, Carrasco M, Barberis S, Castro T, Martínez F, Koch X, Vera JC, Poblete MT, Figueroa CD, Peruzzo B, Pérez F, Nualart F. Differential subcellular distribution of glucose transporters GLUT1–6 and GLUT9 in human cancer: Ultrastructural localization of GLUT1 and GLUT5 in breast tumor tissues. J Cell Physiol 2006; 207:614-27. [PMID: 16523487 DOI: 10.1002/jcp.20606] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It has been proposed that the enhanced metabolic activity of tumor cells is accompanied by an increased expression of facilitative hexose transporters (GLUTs). However, a previous immunohistochemical analysis of GLUT1 expression in 154 malignant human neoplasms failed to detect the GLUT1 isoform in 87 tumors. We used 146 normal human tissues and 215 tumor samples to reassess GLUT1 expression. A similar number of samples were used to compare the expression of GLUT2-6 and 9. The classical expression of GLUT1-5 in different normal human tissues was confirmed, however, we were unable to detect GLUT2 in human pancreatic islet cells. GLUT6 was principally detected in testis germinal cells and GLUT9 was localized in kidney, liver, heart, and adrenal. In tumor samples, GLUT1, 2, and 5 were the main transporters detected. GLUT1 was the most widely expressed transporter, however, 42% of the samples had very low-to-negative expression levels. GLUT2 was detected in 31% of the samples, being mainly expressed in breast, colon, and liver carcinoma. GLUT5 was detected in 27% of breast and colon adenocarcinoma, liver carcinoma, lymphomas, and testis seminoma samples. In situ RT-PCR and ultrastructural immunohistochemistry confirmed GLUT5 expression in breast cancer. GLUT6 and 9 are not clearly over-expressed in human cancer. The extensive expression of GLUT2 and 5 (glucose/fructose and fructose transporters, respectively) in malignant human tissues indicates that fructose may be a good energy substrate in tumor cells. Our functional data obtained in vitro in different tumor cells support this hypothesis. Additionally, these results suggest that fructose uptake could be used for positron emission tomography imaging and, may possibly represent a novel target for the development of therapeutic agents in different human cancers.
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Affiliation(s)
- Alejandro Godoy
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160C, Concepción, Chile
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Abe N, Watanabe T, Ozawa S, Masaki T, Mori T, Sugiyama M, Ishida H, Nagamatsu S, Atomi Y. Pancreatic endocrine function and glucose transporter (GLUT)-2 expression in rat acute pancreatitis. Pancreas 2002; 25:149-53. [PMID: 12142737 DOI: 10.1097/00006676-200208000-00006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
INTRODUCTION Impairment in pancreatic endocrine function is believed to play an important role in the development of glucose intolerance in acute pancreatitis. AIM To investigate the functional aspects of endocrine cells in acute pancreatitis and the expression of glucose transporter (GLUT) 2 in the pancreatitis islet. METHODOLOGY A mild form of acute pancreatitis was induced in rats by an injection of a sodium taurocholate solution via a cannulated biliopancreatic duct. Isolated islets were stimulated by glucose, and insulin secretion was analyzed by radioimmunoassay. Immunohistochemical detection of GLUT2 with use of a specific antibody was attempted to determine GLUT2 expression in pancreatic islets. RESULTS A marked elevation of glucose levels observed in the current rat pancreatitis model confirmed that glucose intolerance can occur even in a mild form of pancreatitis. The architecture of the islets, however, remained intact despite marked inflammatory changes in the neighboring exocrine region. Insulin secretion studies revealed that the ability of islets to secrete insulin in response to glucose was markedly reduced in pancreatitis islets. GLUT2 immunoreactivity in endocrine cells was found to be intact in pancreatitis islets. CONCLUSION The amount of insulin released from isolated islets following glucose stimulation is reduced in acute edematous pancreatitis, although pancreatic islets remain histologically intact. On the basis of the present findings, it appears that although the mechanisms responsible for this functional deficiency remain to be determined, the decrease in insulin secretion is possibly caused by impairment of some pancreatic B-cell functions rather than GLUT2-mediated glucose transportation.
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Affiliation(s)
- Nobutsugu Abe
- First Department of Surgery, Kyorin University School of Medicine, Mitaka City, Tokyo, Japan.
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