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Willmes DM, Daniels M, Kurzbach A, Lieske S, Bechmann N, Schumann T, Henke C, El-Agroudy NN, Da Costa Goncalves AC, Peitzsch M, Hofmann A, Kanczkowski W, Kräker K, Müller DN, Morawietz H, Deussen A, Wagner M, El-Armouche A, Helfand SL, Bornstein SR, de Cabo R, Bernier M, Eisenhofer G, Tank J, Jordan J, Birkenfeld AL. The longevity gene mIndy (I'm Not Dead, Yet) affects blood pressure through sympathoadrenal mechanisms. JCI Insight 2021; 6:136083. [PMID: 33491666 PMCID: PMC7934862 DOI: 10.1172/jci.insight.136083] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022] Open
Abstract
Reduced expression of the plasma membrane citrate transporter INDY (acronym I’m Not Dead, Yet) extends life span in lower organisms. Deletion of the mammalian Indy (mIndy) gene in rodents improves metabolism via mechanisms akin to caloric restriction, known to lower blood pressure (BP) by sympathoadrenal inhibition. We hypothesized that mIndy deletion attenuates sympathoadrenal support of BP. Continuous arterial BP and heart rate (HR) were reduced in mINDY-KO mice. Concomitantly, urinary catecholamine content was lower, and the decreases in BP and HR by mIndy deletion were attenuated after autonomic ganglionic blockade. Catecholamine biosynthesis pathways were reduced in mINDY-KO adrenals using unbiased microarray analysis. Citrate, the main mINDY substrate, increased catecholamine content in pheochromocytoma cells, while pharmacological inhibition of citrate uptake blunted the effect. Our data suggest that deletion of mIndy reduces sympathoadrenal support of BP and HR by attenuating catecholamine biosynthesis. Deletion of mIndy recapitulates beneficial cardiovascular and metabolic responses to caloric restriction, making it an attractive therapeutic target. Deletion of mIndy reduces blood pressure and heart rate by attenuating catecholamine biosynthesis and recapitulates beneficial cardiovascular and metabolic responses to caloric restriction.
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Affiliation(s)
- Diana M Willmes
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Martin Daniels
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany.,Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich, University of Tübingen, Tübingen, Germany.,Department of Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Anica Kurzbach
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany.,Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich, University of Tübingen, Tübingen, Germany.,Department of Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tübingen, Tübingen, Germany.,Department of Diabetes, School of Life Course Science, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Stefanie Lieske
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and
| | - Nicole Bechmann
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Tina Schumann
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Christine Henke
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Nermeen N El-Agroudy
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany.,Department of Diabetes, School of Life Course Science, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | | | - Mirko Peitzsch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Anja Hofmann
- Division of Vascular Endothelium and Microcirculation, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Waldemar Kanczkowski
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Department of Diabetes, School of Life Course Science, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Kristin Kräker
- Experimental and Clinical Research Center, Max Delbruck Center for Molecular Medicine and Charité - University Hospital Berlin, Berlin, Germany
| | - Dominik N Müller
- Experimental and Clinical Research Center, Max Delbruck Center for Molecular Medicine and Charité - University Hospital Berlin, Berlin, Germany
| | - Henning Morawietz
- Division of Vascular Endothelium and Microcirculation, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Andreas Deussen
- Department of Physiology, Medical Faculty Carl Gustav Carus, and
| | - Michael Wagner
- Department of Pharmacology and Toxicology, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Ali El-Armouche
- Department of Pharmacology and Toxicology, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Stephen L Helfand
- Department of Molecular Biology, Cell Biology & Biochemistry, Division of Biology and Medicine, Brown University, Providence, Rhode Island, USA
| | - Stephan R Bornstein
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Department of Diabetes, School of Life Course Science, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
| | - Michel Bernier
- Translational Gerontology Branch, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, USA
| | - Graeme Eisenhofer
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Institute of Clinical Chemistry and Laboratory Medicine, University Hospital and Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Jens Tank
- Aerospace Medicine, University of Cologne, Cologne, Germany
| | - Jens Jordan
- Aerospace Medicine, University of Cologne, Cologne, Germany.,Institute for Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital and Medical Faculty Carl Gustav Carus and.,Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, Technical University Dresden, Dresden, Germany.,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany.,Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich, University of Tübingen, Tübingen, Germany.,Department of Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tübingen, Tübingen, Germany.,Department of Diabetes, School of Life Course Science, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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52
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Mota-Martorell N, Jové M, Borrás C, Berdún R, Obis È, Sol J, Cabré R, Pradas I, Galo-Licona JD, Puig J, Viña J, Pamplona R. Methionine transsulfuration pathway is upregulated in long-lived humans. Free Radic Biol Med 2021; 162:38-52. [PMID: 33271279 DOI: 10.1016/j.freeradbiomed.2020.11.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/10/2020] [Accepted: 11/23/2020] [Indexed: 01/04/2023]
Abstract
Available evidences point to methionine metabolism as a key target to study the molecular adaptive mechanisms underlying differences in longevity. The plasma methionine metabolic profile was determined using a LC-MS/MS platform to systematically define specific phenotypic patterns associated with genotypes of human extreme longevity (centenarians). Our findings demonstrate the presence of a specific plasma profile associated with human longevity characterized by an enhanced transsulfuration pathway and tricarboxylic acid (TCA) cycle intermediates, as well as a reduced content of specific amino acids. Furthermore, our work reveals that centenarians maintain a strongly correlated methionine metabolism, suggesting an improved network integrity, homeostasis and more tightly regulated metabolism. We have discovered a particular methionine signature related to the condition of extreme longevity, allowing the identification of potential mechanisms and biomarkers of healthy aging.
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Affiliation(s)
- Natàlia Mota-Martorell
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Mariona Jové
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Consuelo Borrás
- Freshage Research Group, Department of Physiology, University of Valencia, CIBERFES, INCLIVA, Valencia, Spain.
| | - Rebeca Berdún
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Èlia Obis
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Joaquim Sol
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain; Institut Català de la Salut, Atenció Primària, Lleida, Spain; Research Support Unit Lleida, Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Lleida, Spain.
| | - Rosanna Cabré
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Irene Pradas
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - José Daniel Galo-Licona
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
| | - Josep Puig
- Department of Radiology (Institut de Diagnòstic per la Imatge, IDI), University Hospital Dr Josep Trueta, Girona Biomedical Research Institute (IDIBGI), Girona, Catalonia, Spain.
| | - José Viña
- Freshage Research Group, Department of Physiology, University of Valencia, CIBERFES, INCLIVA, Valencia, Spain.
| | - Reinald Pamplona
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida (UdL-IRBLleida), Lleida, Catalonia, Spain.
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53
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Le J, Fu Y, Han Q, Wei X, Ji H, Chen Y, Wang Q, Pi P, Li J, Lin X, Zhang X, Zhang Y, Ye J. Restoration of mRNA Expression of Solute Carrier Proteins in Liver of Diet-Induced Obese Mice by Metformin. Front Endocrinol (Lausanne) 2021; 12:720784. [PMID: 34659115 PMCID: PMC8515182 DOI: 10.3389/fendo.2021.720784] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 09/08/2021] [Indexed: 02/05/2023] Open
Abstract
Metformin (MET), the most common medicine for type 2 diabetes (T2DM), improves insulin sensitivity by targeting the liver, intestine and other organs. Its impact on expression of the solute carrier (Slc) transporter genes have not been reported in the mechanism of insulin sensitization. In this study, we examined Slc gene expression in the liver and colon of diet-induced obese (DIO) mice treated with MET by transcriptomic analysis. There were 939 differentially expressed genes (DEGs) in the liver of DIO mice vs lean mice, which included 34 Slc genes. MET altered 489 DEGs in the liver of DIO mice, in which 23 were Slc genes. Expression of 20 MET-responsive Slc DEGs was confirmed by qRT-PCR, in which 15 Slc genes were altered in DIO mice and their expressions were restored by MET, including Slc2a10, Slc2a13, Slc5a9, Slc6a14, Slc7a9, Slc9a2, Slc9a3, Slc13a2, Slc15a2, Slc26a3, Slc34a2, Slc37a1, Slc44a4, Slc51b and Slc52a3. While, there were only 97 DEGs in the colon of DIO mice with 5 Slc genes, whose expression was not restored by MET. The data suggest that more genes were altered in the liver over the colon by the high fat diet (HFD). There were 20 Slc genes with alteration confirmed in the liver of DIO mice and 15 of them were restored by MET, which was associated with improvement of insulin sensitivity and obesity. The restoration may improve the uptake of glucose, amino acids, mannose, fructose, 1,5-anhydro-D-glucitol and bumetanide in hepatocytes of the liver of DIO mice. The study provides new insight into the mechanism of metformin action in insulin sensitization and obesity.
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Affiliation(s)
- Jiamei Le
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Yi Fu
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Qiuqin Han
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Xindong Wei
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Department of Surgical Oncology, Nanjing University of Chinese Medicin Affiliated 81st Hospital, Nanjing, China
| | - Houlin Ji
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Graduate School, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yifan Chen
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Qiuying Wang
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Peixian Pi
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Jilei Li
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Xinjie Lin
- Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
- Shanghai Key Laboratory of Molecular Imaging, Collaborative Innovation Center for Biomedicine, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Xiaoying Zhang
- Metabolic Disease Research Center, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Yong Zhang
- Metabolic Disease Research Center, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Jianping Ye
- Metabolic Disease Research Center, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, China
- Center for Advanced Medicine, College of Medicine, Zhengzhou University, Zhengzhou, China
- Shanghai Diabetes Institute, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
- *Correspondence: Jianping Ye, ;
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54
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Fan SZ, Sung CW, Tsai YH, Yeh SR, Lin WS, Wang PY. Nervous System Deletion of Mammalian INDY in Mice Mimics Dietary Restriction-Induced Memory Enhancement. J Gerontol A Biol Sci Med Sci 2021; 76:50-56. [PMID: 32808644 DOI: 10.1093/gerona/glaa203] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Indexed: 02/06/2023] Open
Abstract
Reduced expression of the Indy (I'm Not Dead Yet) gene extends life span in Caenorhabditis elegans and Drosophila melanogaster and improves the metabolic heath of Mus musculus through inducing a physiological status akin to dietary restriction (DR). Although the function of Indy in aging and hepatic metabolism has been extensively studied, its role in the mouse nervous system remains unclear. Here, we explore the effect of mammalian Indy (mIndy, SLC13A5) gene deletion on murine cognitive function. Similar to what is seen in DR animals, systemic deletion of the mIndy gene (mIndy knockout [KO]) significantly improves memory performance and motor coordination of mice. Both DR and mIndy KO mice act normally in other behavioral tasks, including emotional, social, and food-seeking behaviors. Moreover, we find that tissue-specific deletion of mIndy in the nervous system is sufficient to improve memory performance, while liver-specific deletion has no effect on memory, and results in tests of motor coordination show no changes in either mutant. Mice with systemic or nervous system deletion of mIndy also exhibit increased hippocampal neurogenesis and dendritic spine formation in dentate granule cells; these changes are well-documented contributors to enhanced memory performance. Together, our studies demonstrate a critical role for brain-derived mIndy expression in the regulation of memory function in animals.
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Affiliation(s)
- Shou-Zen Fan
- Department of Anesthesiology, National Taiwan University Hospital, National Taiwan University, Taipei
| | - Chih-Wei Sung
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei
| | - Yi-Hsuan Tsai
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei
| | - Sheng-Rong Yeh
- Department of Anesthesiology, National Taiwan University Hospital, National Taiwan University, Taipei.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei
| | - Wei-Sheng Lin
- Department of Pediatrics, Taipei Veterans General Hospital, Taiwan
| | - Pei-Yu Wang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei.,Ph.D. Program in Translational Medicine, National Taiwan University and Academia Sinica, Taipei.,Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Taiwan University and Academia Sinica, Taipei.,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
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55
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Sampson CDD, Stewart MJ, Mindell JA, Mulligan C. Solvent accessibility changes in a Na +-dependent C 4-dicarboxylate transporter suggest differential substrate effects in a multistep mechanism. J Biol Chem 2020; 295:18524-18538. [PMID: 33087444 PMCID: PMC7939474 DOI: 10.1074/jbc.ra120.013894] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 10/06/2020] [Indexed: 11/06/2022] Open
Abstract
The divalent anion sodium symporter (DASS) family (SLC13) plays critical roles in metabolic homeostasis, influencing many processes, including fatty acid synthesis, insulin resistance, and adiposity. DASS transporters catalyze the Na+-driven concentrative uptake of Krebs cycle intermediates and sulfate into cells; disrupting their function can protect against age-related metabolic diseases and can extend lifespan. An inward-facing crystal structure and an outward-facing model of a bacterial DASS family member, VcINDY from Vibrio cholerae, predict an elevator-like transport mechanism involving a large rigid body movement of the substrate-binding site. How substrate binding influences the conformational state of VcINDY is currently unknown. Here, we probe the interaction between substrate binding and protein conformation by monitoring substrate-induced solvent accessibility changes of broadly distributed positions in VcINDY using a site-specific alkylation strategy. Our findings reveal that accessibility to all positions tested is modulated by the presence of substrates, with the majority becoming less accessible in the presence of saturating concentrations of both Na+ and succinate. We also observe separable effects of Na+ and succinate binding at several positions suggesting distinct effects of the two substrates. Furthermore, accessibility changes to a solely succinate-sensitive position suggests that substrate binding is a low-affinity, ordered process. Mapping these accessibility changes onto the structures of VcINDY suggests that Na+ binding drives the transporter into an as-yet-unidentified conformational state, involving rearrangement of the substrate-binding site-associated re-entrant hairpin loops. These findings provide insight into the mechanism of VcINDY, which is currently the only structurally characterized representative of the entire DASS family.
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Affiliation(s)
- Connor D D Sampson
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Matthew J Stewart
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, NINDS, National Institutes of Health, Bethesda, Maryland, USA
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56
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Haferkamp S, Drexler K, Federlin M, Schlitt HJ, Berneburg M, Adamski J, Gaumann A, Geissler EK, Ganapathy V, Parkinson EK, Mycielska ME. Extracellular Citrate Fuels Cancer Cell Metabolism and Growth. Front Cell Dev Biol 2020; 8:602476. [PMID: 33425906 PMCID: PMC7793864 DOI: 10.3389/fcell.2020.602476] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
Cancer cells need excess energy and essential nutrients/metabolites not only to divide and proliferate but also to migrate and invade distant organs for metastasis. Fatty acid and cholesterol synthesis, considered a hallmark of cancer for anabolism and membrane biogenesis, requires citrate. We review here potential pathways in which citrate is synthesized and/or supplied to cancer cells and the impact of extracellular citrate on cancer cell metabolism and growth. Cancer cells employ different mechanisms to support mitochondrial activity and citrate synthesis when some of the necessary substrates are missing in the extracellular space. We also discuss the different transport mechanisms available for the entry of extracellular citrate into cancer cells and how citrate as a master metabolite enhances ATP production and fuels anabolic pathways. The available literature suggests that cancer cells show an increased metabolic flexibility with which they tackle changing environmental conditions, a phenomenon crucial for cancer cell proliferation and metastasis.
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Affiliation(s)
| | - Konstantin Drexler
- Department of Dermatology, University Medical Center, Regensburg, Germany
| | - Marianne Federlin
- Department of Conservative Dentistry and Periodontology, University Medical Center, Regensburg, Germany
| | - Hans J. Schlitt
- Department of Surgery, University Medical Center Regensburg, Regensburg, Germany
| | - Mark Berneburg
- Department of Dermatology, University Medical Center, Regensburg, Germany
| | - Jerzy Adamski
- Research Unit Molecular Endocrinology and Metabolism, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Lehrstuhl für Experimentelle Genetik, Technische Universität München, Munich, Germany
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Andreas Gaumann
- Institute of Pathology, Kaufbeuren-Ravensburg, Kaufbeuren, Germany
| | - Edward K. Geissler
- Department of Surgery, University Medical Center Regensburg, Regensburg, Germany
| | - Vadivel Ganapathy
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - E. Kenneth Parkinson
- Center for Immunobiology and Regenerative Medicine, Barts and The London School of Medicine and Dentistry, Blizard Institute, London, United Kingdom
| | - Maria E. Mycielska
- Department of Surgery, University Medical Center Regensburg, Regensburg, Germany
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57
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Abulizi A, Vatner DF, Ye Z, Wang Y, Camporez JP, Zhang D, Kahn M, Lyu K, Sirwi A, Cline GW, Hussain MM, Aspichueta P, Samuel VT, Shulman GI. Membrane-bound sn-1,2-diacylglycerols explain the dissociation of hepatic insulin resistance from hepatic steatosis in MTTP knockout mice. J Lipid Res 2020; 61:1565-1576. [PMID: 32907986 PMCID: PMC7707176 DOI: 10.1194/jlr.ra119000586] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Microsomal triglyceride transfer protein (MTTP) deficiency results in a syndrome of hypolipidemia and accelerated NAFLD. Animal models of decreased hepatic MTTP activity have revealed an unexplained dissociation between hepatic steatosis and hepatic insulin resistance. Here, we performed comprehensive metabolic phenotyping of liver-specific MTTP knockout (L-Mttp-/-) mice and age-weight matched wild-type control mice. Young (10-12-week-old) L-Mttp-/- mice exhibited hepatic steatosis and increased DAG content; however, the increase in hepatic DAG content was partitioned to the lipid droplet and was not increased in the plasma membrane. Young L-Mttp-/- mice also manifested normal hepatic insulin sensitivity, as assessed by hyperinsulinemic-euglycemic clamps, no PKCε activation, and normal hepatic insulin signaling from the insulin receptor through AKT Ser/Thr kinase. In contrast, aged (10-month-old) L-Mttp-/- mice exhibited glucose intolerance and hepatic insulin resistance along with an increase in hepatic plasma membrane sn-1,2-DAG content and PKCε activation. Treatment with a functionally liver-targeted mitochondrial uncoupler protected the aged L-Mttp-/- mice against the development of hepatic steatosis, increased plasma membrane sn-1,2-DAG content, PKCε activation, and hepatic insulin resistance. Furthermore, increased hepatic insulin sensitivity in the aged controlled-release mitochondrial protonophore-treated L-Mttp-/- mice was not associated with any reductions in hepatic ceramide content. Taken together, these data demonstrate that differences in the intracellular compartmentation of sn-1,2-DAGs in the lipid droplet versus plasma membrane explains the dissociation of NAFLD/lipid-induced hepatic insulin resistance in young L-Mttp-/- mice as well as the development of lipid-induced hepatic insulin resistance in aged L-Mttp-/- mice.
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Affiliation(s)
- Abudukadier Abulizi
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Daniel F Vatner
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Zhang Ye
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Yongliang Wang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Joao-Paulo Camporez
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Dongyan Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Mario Kahn
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Kun Lyu
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Alaa Sirwi
- Departments of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Mineola, NY, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - M Mahmood Hussain
- Departments of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Mineola, NY, USA; Department of Foundations of Medicine, NYU Long Island School of Medicine, Mineola, NY, USA
| | - Patricia Aspichueta
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain; Biocruces Research Institute, Barakaldo, Spain
| | - Varman T Samuel
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA; Veterans Affairs Medical Center, West Haven, CT, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.
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Targeting metabolic pathways for extension of lifespan and healthspan across multiple species. Ageing Res Rev 2020; 64:101188. [PMID: 33031925 DOI: 10.1016/j.arr.2020.101188] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/20/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022]
Abstract
Metabolism plays a significant role in the regulation of aging at different levels, and metabolic reprogramming represents a major driving force in aging. Metabolic reprogramming leads to impaired organismal fitness, an age-dependent increase in susceptibility to diseases, decreased ability to mount a stress response, and increased frailty. The complexity of age-dependent metabolic reprogramming comes from the multitude of levels on which metabolic changes can be connected to aging and regulation of lifespan. This is further complicated by the different metabolic requirements of various tissues, cross-organ communication via metabolite secretion, and direct effects of metabolites on epigenetic state and redox regulation; however, not all of these changes are causative to aging. Studies in yeast, flies, worms, and mice have played a crucial role in identifying mechanistic links between observed changes in various metabolic traits and their effects on lifespan. Here, we review how changes in the organismal and organ-specific metabolome are associated with aging and how targeting of any one of over a hundred different targets in specific metabolic pathways can extend lifespan. An important corollary is that restriction or supplementation of different metabolites can change activity of these metabolic pathways in ways that improve healthspan and extend lifespan in different organisms. Due to the high levels of conservation of metabolism in general, translating findings from model systems to human beings will allow for the development of effective strategies for human health- and lifespan extension.
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Abstract
The mechanisms responsible for the trafficking of carboxylate ions across cell membranes are becoming clearer.
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Affiliation(s)
- Adam W Duster
- Department of Integrative Biology, University of Colorado Denver, Denver, United States
| | - Hai Lin
- Chemistry Department, University of Colorado Denver, Denver, United States
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Schumann T, König J, Henke C, Willmes DM, Bornstein SR, Jordan J, Fromm MF, Birkenfeld AL. Solute Carrier Transporters as Potential Targets for the Treatment of Metabolic Disease. Pharmacol Rev 2020; 72:343-379. [PMID: 31882442 DOI: 10.1124/pr.118.015735] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The solute carrier (SLC) superfamily comprises more than 400 transport proteins mediating the influx and efflux of substances such as ions, nucleotides, and sugars across biological membranes. Over 80 SLC transporters have been linked to human diseases, including obesity and type 2 diabetes (T2D). This observation highlights the importance of SLCs for human (patho)physiology. Yet, only a small number of SLC proteins are validated drug targets. The most recent drug class approved for the treatment of T2D targets sodium-glucose cotransporter 2, product of the SLC5A2 gene. There is great interest in identifying other SLC transporters as potential targets for the treatment of metabolic diseases. Finding better treatments will prove essential in future years, given the enormous personal and socioeconomic burden posed by more than 500 million patients with T2D by 2040 worldwide. In this review, we summarize the evidence for SLC transporters as target structures in metabolic disease. To this end, we identified SLC13A5/sodium-coupled citrate transporter, and recent proof-of-concept studies confirm its therapeutic potential in T2D and nonalcoholic fatty liver disease. Further SLC transporters were linked in multiple genome-wide association studies to T2D or related metabolic disorders. In addition to presenting better-characterized potential therapeutic targets, we discuss the likely unnoticed link between other SLC transporters and metabolic disease. Recognition of their potential may promote research on these proteins for future medical management of human metabolic diseases such as obesity, fatty liver disease, and T2D. SIGNIFICANCE STATEMENT: Given the fact that the prevalence of human metabolic diseases such as obesity and type 2 diabetes has dramatically risen, pharmacological intervention will be a key future approach to managing their burden and reducing mortality. In this review, we present the evidence for solute carrier (SLC) genes associated with human metabolic diseases and discuss the potential of SLC transporters as therapeutic target structures.
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Affiliation(s)
- Tina Schumann
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Jörg König
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Christine Henke
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Diana M Willmes
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Stefan R Bornstein
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Jens Jordan
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Martin F Fromm
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine (T.S., C.H., D.M.W., S.R.B.), and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine (T.S., C.H., D.M.W.), Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Diabetesforschung e.V., Neuherberg, Germany (T.S., C.H., D.M.W., A.L.B.); Clinical Pharmacology and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (J.K., M.F.F.); Institute for Aerospace Medicine, German Aerospace Center and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany (J.J.); Diabetes and Nutritional Sciences, King's College London, London, United Kingdom (S.R.B., A.L.B.); Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany (A.L.B.); and Department of Internal Medicine, Division of Endocrinology, Diabetology and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany (A.L.B.)
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Hu T, Huang W, Li Z, Kane MA, Zhang L, Huang SM, Wang H. Comparative proteomic analysis of SLC13A5 knockdown reveals elevated ketogenesis and enhanced cellular toxic response to chemotherapeutic agents in HepG2 cells. Toxicol Appl Pharmacol 2020; 402:115117. [PMID: 32634519 DOI: 10.1016/j.taap.2020.115117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/29/2022]
Abstract
Solute carrier family 13 member 5 (SLC13A5) is an uptake transporter mainly expressed in the liver and transports citrate from blood circulation into hepatocytes. Accumulating evidence suggests that SLC13A5 is involved in hepatic lipogenesis, cell proliferation, epilepsy, and bone development in mammals. However, the molecular mechanisms behind SLC13A5-mediated physiological/pathophysiological changes are largely unknown. In this regard, we conducted a differential proteome analysis in HepG2 and SLC13A5-knockdown (KD) HepG2 cells. A total of 3826 proteins were quantified and 330 proteins showed significant alterations (fold change ≥1.5; p < .05) in the knockdown cells. Gene ontology enrichment analysis reveals that 38 biological processes were significantly changed, with ketone body biosynthetic process showing the most significant upregulation following SLC13A5-KD. Catalytic activity and binding activity were the top two molecular functions associated with differentially expressed proteins, while HMG-CoA lyase activity showed the highest fold enrichment. Further ingenuity pathway analysis predicted 40 canonical pathways and 28 upstream regulators (p < .01), of which most were associated with metabolism, cell proliferation, and stress response. In line with these findings, functional validation demonstrated increased levels of two key ketone bodies, acetoacetate and β-hydroxybutyrate, in the SLC13A5-KD cells. Additional experiments showed that SLC13A5-KD sensitizes HepG2 cells to cellular stress caused by a number of chemotherapeutic agents. Together, our findings demonstrate that knockdown of SLC13A5 promotes hepatic ketogenesis and enhances cellular stress response in HepG2 cells, suggesting a potential role of this transporter in metabolic disorders and liver cancer.
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Affiliation(s)
- Tao Hu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, United States of America
| | - Weiliang Huang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, United States of America
| | - Zhihui Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, United States of America
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, United States of America
| | - Lei Zhang
- Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, United States of America
| | - Shiew-Mei Huang
- Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, United States of America
| | - Hongbing Wang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, United States of America.
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62
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Sauer DB, Trebesch N, Marden JJ, Cocco N, Song J, Koide A, Koide S, Tajkhorshid E, Wang DN. Structural basis for the reaction cycle of DASS dicarboxylate transporters. eLife 2020; 9:e61350. [PMID: 32869741 PMCID: PMC7553777 DOI: 10.7554/elife.61350] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023] Open
Abstract
Citrate, α-ketoglutarate and succinate are TCA cycle intermediates that also play essential roles in metabolic signaling and cellular regulation. These di- and tricarboxylates are imported into the cell by the divalent anion sodium symporter (DASS) family of plasma membrane transporters, which contains both cotransporters and exchangers. While DASS proteins transport substrates via an elevator mechanism, to date structures are only available for a single DASS cotransporter protein in a substrate-bound, inward-facing state. We report multiple cryo-EM and X-ray structures in four different states, including three hitherto unseen states, along with molecular dynamics simulations, of both a cotransporter and an exchanger. Comparison of these outward- and inward-facing structures reveal how the transport domain translates and rotates within the framework of the scaffold domain through the transport cycle. Additionally, we propose that DASS transporters ensure substrate coupling by a charge-compensation mechanism, and by structural changes upon substrate release.
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Affiliation(s)
- David B Sauer
- Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew YorkUnited States
- Department of Cell Biology, New York University School of MedicineNew YorkUnited States
| | - Noah Trebesch
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Jennifer J Marden
- Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew YorkUnited States
- Department of Cell Biology, New York University School of MedicineNew YorkUnited States
| | - Nicolette Cocco
- Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew YorkUnited States
- Department of Cell Biology, New York University School of MedicineNew YorkUnited States
| | - Jinmei Song
- Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew YorkUnited States
- Department of Cell Biology, New York University School of MedicineNew YorkUnited States
| | - Akiko Koide
- Perlmutter Cancer Center, New York University School of MedicineNew YorkUnited States
- Department of Medicine, New York University School of MedicineNew YorkUnited States
| | - Shohei Koide
- Perlmutter Cancer Center, New York University School of MedicineNew YorkUnited States
- Department of Medicine, New York University School of MedicineNew YorkUnited States
- Department of Biochemistry and Molecular Pharmacology, New York University School of MedicineNew YorkUnited States
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Da-Neng Wang
- Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew YorkUnited States
- Department of Cell Biology, New York University School of MedicineNew YorkUnited States
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63
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Henke C, Töllner K, van Dijk RM, Miljanovic N, Cordes T, Twele F, Bröer S, Ziesak V, Rohde M, Hauck SM, Vogel C, Welzel L, Schumann T, Willmes DM, Kurzbach A, El-Agroudy NN, Bornstein SR, Schneider SA, Jordan J, Potschka H, Metallo CM, Köhling R, Birkenfeld AL, Löscher W. Disruption of the sodium-dependent citrate transporter SLC13A5 in mice causes alterations in brain citrate levels and neuronal network excitability in the hippocampus. Neurobiol Dis 2020; 143:105018. [PMID: 32682952 DOI: 10.1016/j.nbd.2020.105018] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/08/2020] [Accepted: 07/11/2020] [Indexed: 12/28/2022] Open
Abstract
In addition to tissues such as liver, the plasma membrane sodium-dependent citrate transporter, NaCT (SLC13A5), is highly expressed in brain neurons, but its function is not understood. Loss-of-function mutations in the human SLC13A5 gene have been associated with severe neonatal encephalopathy and pharmacoresistant seizures. The molecular mechanisms of these neurological alterations are not clear. We performed a detailed examination of a Slc13a5 deletion mouse model including video-EEG monitoring, behavioral tests, and electrophysiologic, proteomic, and metabolomic analyses of brain and cerebrospinal fluid. The experiments revealed an increased propensity for epileptic seizures, proepileptogenic neuronal excitability changes in the hippocampus, and significant citrate alterations in the CSF and brain tissue of Slc13a5 deficient mice, which may underlie the neurological abnormalities. These data demonstrate that SLC13A5 is involved in brain citrate regulation and suggest that abnormalities in this regulation can induce seizures. The present study is the first to (i) establish the Slc13a5-knockout mouse model as a helpful tool to study the neuronal functions of NaCT and characterize the molecular mechanisms by which functional deficiency of this citrate transporter causes epilepsy and impairs neuronal function; (ii) evaluate all hypotheses that have previously been suggested on theoretical grounds to explain the neurological phenotype of SLC13A5 mutations; and (iii) indicate that alterations in brain citrate levels result in neuronal network excitability and increased seizure propensity.
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Affiliation(s)
- Christine Henke
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - R Maarten van Dijk
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Nina Miljanovic
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Thekla Cordes
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Friederike Twele
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Sonja Bröer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Vanessa Ziesak
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Marco Rohde
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Center Munich, Neuherberg, Germany
| | - Charlotte Vogel
- Department of Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Germany
| | - Lisa Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Tina Schumann
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Diana M Willmes
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Anica Kurzbach
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Nermeen N El-Agroudy
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Stefan R Bornstein
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany
| | | | - Jens Jordan
- Institute for Aerospace Medicine, German Aerospace Center (DLR) and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Christian M Metallo
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Rüdiger Köhling
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany.
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Szeri F, Lundkvist S, Donnelly S, Engelke UFH, Rhee K, Williams CJ, Sundberg JP, Wevers RA, Tomlinson RE, Jansen RS, van de Wetering K. The membrane protein ANKH is crucial for bone mechanical performance by mediating cellular export of citrate and ATP. PLoS Genet 2020; 16:e1008884. [PMID: 32639996 PMCID: PMC7371198 DOI: 10.1371/journal.pgen.1008884] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/20/2020] [Accepted: 05/25/2020] [Indexed: 01/23/2023] Open
Abstract
The membrane protein ANKH was known to prevent pathological mineralization of joints and was thought to export pyrophosphate (PPi) from cells. This did not explain, however, the presence of ANKH in tissues, such as brain, blood vessels and muscle. We now report that in cultured cells ANKH exports ATP, rather than PPi, and, unexpectedly, also citrate as a prominent metabolite. The extracellular ATP is rapidly converted into PPi, explaining the role of ANKH in preventing ankylosis. Mice lacking functional Ank (Ankank/ank mice) had plasma citrate concentrations that were 65% lower than those detected in wild type control animals. Consequently, citrate excretion via the urine was substantially reduced in Ankank/ank mice. Citrate was even undetectable in the urine of a human patient lacking functional ANKH. The hydroxyapatite of Ankank/ank mice contained dramatically reduced levels of both, citrate and PPi and displayed diminished strength. Our results show that ANKH is a critical contributor to extracellular citrate and PPi homeostasis and profoundly affects bone matrix composition and, consequently, bone quality.
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Affiliation(s)
- Flora Szeri
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Stefan Lundkvist
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Sylvia Donnelly
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Udo F. H. Engelke
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kyu Rhee
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, New York, United States of America
| | - Charlene J. Williams
- Cooper Medical School of Rowan University, Camden, New Jersey, United States of America
| | - John P. Sundberg
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Ron A. Wevers
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ryan E. Tomlinson
- Department of Orthopedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Robert S. Jansen
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, New York, United States of America
| | - Koen van de Wetering
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Yang QZ, Spelbrink EM, Nye KL, Hsu ER, Porter BE. Epilepsy and EEG Phenotype of SLC13A5 Citrate Transporter Disorder. Child Neurol Open 2020; 7:2329048X20931361. [PMID: 32551328 PMCID: PMC7281881 DOI: 10.1177/2329048x20931361] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/28/2020] [Accepted: 05/10/2020] [Indexed: 11/15/2022] Open
Abstract
Mutations in the SLC13A5 gene, a sodium citrate cotransporter, cause a rare autosomal recessive epilepsy (EIEE25) that begins during the neonatal period and is associated with motor and cognitive impairment. Patient's seizure burden, semiology, and electroencephalography (EEG) findings have not been well characterized. Data on 23 patients, 3 months to 29 years of age are reported. Seizures began during the neonatal period in 22 patients. Although seizures are quite severe in many patients later in life, seizure freedom was attainable in a minority of patients. Multiple patients' chronic seizure management included a few common medications, phenobarbital and valproic acid in particular. Patients EEGs had a relatively well-preserved background for age, even in the face of frequent seizures, little slowing and multiple normal EEGs and do not support an epileptic encephalopathy. Other causes for the motor and cognitive delay beyond epilepsy warrant further study.
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Affiliation(s)
- Qian-Zhou Yang
- Division of Child Neurology, Department of Neurology, Stanford University School of Medicine, CA, USA
| | - Emily M Spelbrink
- Division of Child Neurology, Department of Neurology, Stanford University School of Medicine, CA, USA
| | | | - Emily R Hsu
- TESS Research Foundation, Redwood City, CA, USA
| | - Brenda E Porter
- Division of Child Neurology, Department of Neurology, Stanford University School of Medicine, CA, USA
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66
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Goedeke L, Perry RJ, Shulman GI. Emerging Pharmacological Targets for the Treatment of Nonalcoholic Fatty Liver Disease, Insulin Resistance, and Type 2 Diabetes. Annu Rev Pharmacol Toxicol 2020; 59:65-87. [PMID: 30625285 DOI: 10.1146/annurev-pharmtox-010716-104727] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes (T2D) is characterized by persistent hyperglycemia despite hyperinsulinemia, affects more than 400 million people worldwide, and is a major cause of morbidity and mortality. Insulin resistance, of which ectopic lipid accumulation in the liver [nonalcoholic fatty liver disease (NAFLD)] and skeletal muscle is the root cause, plays a major role in the development of T2D. Although lifestyle interventions and weight loss are highly effective at reversing NAFLD and T2D, weight loss is difficult to sustain, and newer approaches aimed at treating the root cause of T2D are urgently needed. In this review, we highlight emerging pharmacological strategies aimed at improving insulin sensitivity and T2D by altering hepatic energy balance or inhibiting key enzymes involved in hepatic lipid synthesis. We also summarize recent research suggesting that liver-targeted mitochondrial uncoupling may be an attractive therapeutic approach to treat NAFLD, nonalcoholic steatohepatitis, and T2D.
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Affiliation(s)
- Leigh Goedeke
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA; , ,
| | - Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA; , , .,Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA; , , .,Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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67
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Hudry B, de Goeij E, Mineo A, Gaspar P, Hadjieconomou D, Studd C, Mokochinski JB, Kramer HB, Plaçais PY, Preat T, Miguel-Aliaga I. Sex Differences in Intestinal Carbohydrate Metabolism Promote Food Intake and Sperm Maturation. Cell 2020; 178:901-918.e16. [PMID: 31398343 PMCID: PMC6700282 DOI: 10.1016/j.cell.2019.07.029] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 05/31/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023]
Abstract
Physiology and metabolism are often sexually dimorphic, but the underlying mechanisms remain incompletely understood. Here, we use the intestine of Drosophila melanogaster to investigate how gut-derived signals contribute to sex differences in whole-body physiology. We find that carbohydrate handling is male-biased in a specific portion of the intestine. In contrast to known sexual dimorphisms in invertebrates, the sex differences in intestinal carbohydrate metabolism are extrinsically controlled by the adjacent male gonad, which activates JAK-STAT signaling in enterocytes within this intestinal portion. Sex reversal experiments establish roles for this male-biased intestinal metabolic state in controlling food intake and sperm production through gut-derived citrate. Our work uncovers a male gonad-gut axis coupling diet and sperm production, revealing that metabolic communication across organs is physiologically important. The instructive role of citrate in inter-organ communication might be significant in more biological contexts than previously recognized. Intestinal carbohydrate metabolism is male-biased and region-specific Testes masculinize gut sugar handling by promoting enterocyte JAK-STAT signaling The male intestine secretes citrate to the adjacent testes Gut-derived citrate promotes food intake and sperm maturation
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Affiliation(s)
- Bruno Hudry
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; Université Côte d'Azur, CNRS, INSERM, iBV, France.
| | - Eva de Goeij
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Alessandro Mineo
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Pedro Gaspar
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Dafni Hadjieconomou
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Chris Studd
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Joao B Mokochinski
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Holger B Kramer
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Pierre-Yves Plaçais
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK.
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68
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Khamaysi A, Aharon S, Eini-Rider H, Ohana E. A dynamic anchor domain in slc13 transporters controls metabolite transport. J Biol Chem 2020; 295:8155-8163. [PMID: 32152229 DOI: 10.1074/jbc.ra119.010911] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 02/26/2020] [Indexed: 12/11/2022] Open
Abstract
Metabolite transport across cellular membranes is required for bioenergetic processes and metabolic signaling. The solute carrier family 13 (slc13) transporters mediate transport of the metabolites succinate and citrate and hence are of paramount physiological importance. Nevertheless, the mechanisms of slc13 transport and regulation are poorly understood. Here, a dynamic structural slc13 model suggested that an interfacial helix, H4c, which is common to all slc13s, stabilizes the stationary scaffold domain by anchoring it to the membrane, thereby facilitating movement of the SLC13 catalytic domain. Moreover, we found that intracellular determinants interact with the H4c anchor domain to modulate transport. This dual function is achieved by basic residues that alternately face either the membrane phospholipids or the intracellular milieu. This mechanism was supported by several experimental findings obtained using biochemical methods, electrophysiological measurements in Xenopus oocytes, and fluorescent microscopy of mammalian cells. First, a positively charged and highly conserved H4c residue, Arg108, was indispensable and crucial for metabolite transport. Furthermore, neutralization of other H4c basic residues inhibited slc13 transport function, thus mimicking the inhibitory effect of the slc13 inhibitor, slc26a6. Our findings suggest that the positive charge distribution across H4c domain controls slc13 transporter function and is utilized by slc13-interacting proteins in the regulation of metabolite transport.
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Affiliation(s)
- Ahlam Khamaysi
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Sara Aharon
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Hadar Eini-Rider
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Ehud Ohana
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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69
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Yang J, Khan MAK, Zhang H, Zhang Y, Certik M, Garre V, Song Y. Mitochondrial Citrate Transport System in the Fungus Mucor circinelloides: Identification, Phylogenetic Analysis, and Expression Profiling During Growth and Lipid Accumulation. Curr Microbiol 2019; 77:220-231. [PMID: 31802201 DOI: 10.1007/s00284-019-01822-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/20/2019] [Indexed: 12/21/2022]
Abstract
The mitochondrial citrate transport system, composed of citrate and malate transporters (MTs), can regulate the citrate efflux from mitochondria to cytosol, and then citrate is cleaved into OAA and acetyl-CoA which can be used for fatty acid (FA) biosynthesis. However, in the fungus Mucor circinelloides the molecular mechanism of citrate efflux from the mitochondria by this system and its role in FA synthesis is unclear. In the present study, we have analyzed the genome of high lipid-producing strain WJ11 and the low lipid-producing strain CBS 277.49 to find the potential genes involving in this system. Five potential genes are present in the genome of WJ11. These genes encode one citrate transport protein (CT), one tricarboxylate carrier (TCT), one MT, and two 2-oxoglutarate:malate antiporters (SoDIT-a and SoDIT-b). However, the genome of CBS 277.49 contains the same set of genes, except for the presence of just one SoDIT. The proteins from WJ11 had similar properties as their counterparts in CBS 277.49. Moreover, phylogenetic analyses revealed the evolutionary relationship of these proteins and illuminated their typical motifs related to potential functions. Additionally, the expression of these genes was analyzed to predict the possible functions in lipid metabolism in M. circinelloides. This is the first study to report the in silico analysis of structures and functions of the mitochondrial citrate transport system in M. circinelloides. This work showed a new strategy for research for the selection of candidate genes for further detailed functional investigation of the mitochondrial citrate transport system in lipid accumulation.
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Affiliation(s)
- Junhuan Yang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, Shandong, People's Republic of China
| | - Md Ahsanul Kabir Khan
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, Shandong, People's Republic of China
| | - Huaiyuan Zhang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, Shandong, People's Republic of China
| | - Yao Zhang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, Shandong, People's Republic of China
| | - Milan Certik
- Institute of Biotechnology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 812 37, Bratislava, Slovakia
| | - Victoriano Garre
- Departmento de Genética Y Microbiología (Unidad Asociada Al Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain.
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, Shandong, People's Republic of China.
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70
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Rathje CC, Randle SJ, Al Rawi S, Skinner BM, Nelson DE, Majumdar A, Johnson EEP, Bacon J, Vlazaki M, Affara NA, Ellis PJ, Laman H. A Conserved Requirement for Fbxo7 During Male Germ Cell Cytoplasmic Remodeling. Front Physiol 2019; 10:1278. [PMID: 31649556 PMCID: PMC6795710 DOI: 10.3389/fphys.2019.01278] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 09/23/2019] [Indexed: 12/15/2022] Open
Abstract
Fbxo7 is the substrate-recognition subunit of an SCF-type ubiquitin E3 ligase complex. It has physiologically important functions in regulating mitophagy, proteasome activity and the cell cycle in multiple cell types, like neurons, lymphocytes and erythrocytes. Here, we show that in addition to the previously known Parkinsonian and hematopoietic phenotypes, male mice with reduced Fbxo7 expression are sterile. In these males, despite successful meiosis, nuclear elongation and eviction of histones from chromatin, the developing spermatids are phagocytosed by Sertoli cells during late spermiogenesis, as the spermatids undergo cytoplasmic remodeling. Surprisingly, despite the loss of all germ cells, there was no evidence of the symplast formation and cell sloughing that is typically associated with spermatid death in other mouse sterility models, suggesting that novel cell death and/or cell disposal mechanisms may be engaged in Fbxo7 mutant males. Mutation of the Drosophila Fbxo7 ortholog, nutcracker (ntc) also leads to sterility with germ cell death during cytoplasmic remodeling, indicating that the requirement for Fbxo7 at this stage is conserved. The ntc phenotype was attributed to decreased levels of the proteasome regulator, DmPI31 and reduced proteasome activity. Consistent with the fly model, we observe a reduction in PI31 levels in mutant mice; however, there is no alteration in proteasome activity in whole mouse testes. Our results are consistent with findings that Fbxo7 regulates PI31 protein levels, and indicates that a defect at the late stages of spermiogenesis, possibly due to faulty spatial dynamics of proteasomes during cytoplasmic remodeling, may underlie the fertility phenotype in mice.
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Affiliation(s)
- Claudia C Rathje
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Suzanne J Randle
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Sara Al Rawi
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Benjamin M Skinner
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - David E Nelson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Antara Majumdar
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Emma E P Johnson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Joanne Bacon
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Myrto Vlazaki
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Nabeel A Affara
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Peter J Ellis
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Heike Laman
- School of Biosciences, University of Kent, Canterbury, United Kingdom
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71
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Metabolic Biomarkers in Aging and Anti-Aging Research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1178:247-264. [PMID: 31493231 DOI: 10.1007/978-3-030-25650-0_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although human life expectancy has increased significantly over the last two centuries, this has not been paralleled by a similar rise in healthy life expectancy. Thus, an important goal of anti-aging research has been to reduce the impact of age-associated diseases as a way of extending the human healthspan. This review will explore some of the potential avenues which have emerged from this research as the most promising strategies and drug targets for therapeutic interventions to promote healthy aging.
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72
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Atp6ap2 deletion causes extensive vacuolation that consumes the insulin content of pancreatic β cells. Proc Natl Acad Sci U S A 2019; 116:19983-19988. [PMID: 31527264 DOI: 10.1073/pnas.1903678116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Pancreatic β cells store insulin within secretory granules which undergo exocytosis upon elevation of blood glucose levels. Crinophagy and autophagy are instead responsible to deliver damaged or old granules to acidic lysosomes for intracellular degradation. However, excessive consumption of insulin granules can impair β cell function and cause diabetes. Atp6ap2 is an essential accessory component of the vacuolar ATPase required for lysosomal degradative functions and autophagy. Here, we show that Cre recombinase-mediated conditional deletion of Atp6ap2 in mouse β cells causes a dramatic accumulation of large, multigranular vacuoles in the cytoplasm, with reduction of insulin content and compromised glucose homeostasis. Loss of insulin stores and gigantic vacuoles were also observed in cultured insulinoma INS-1 cells upon CRISPR/Cas9-mediated removal of Atp6ap2. Remarkably, these phenotypic alterations could not be attributed to a deficiency in autophagy or acidification of lysosomes. Together, these data indicate that Atp6ap2 is critical for regulating the stored insulin pool and that a balanced regulation of granule turnover is key to maintaining β cell function and diabetes prevention.
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73
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Deacetylation of metabolic enzymes by Sirt2 modulates pyruvate homeostasis to extend insect lifespan. Aging (Albany NY) 2019; 10:1053-1072. [PMID: 29769432 PMCID: PMC5990394 DOI: 10.18632/aging.101447] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/08/2018] [Indexed: 12/13/2022]
Abstract
Diapause in insects is akin to dauer in Caenorhabditis elegans and hibernation in vertebrates. Diapause causes a profound extension of lifespan by low metabolic activity. However, the detailed regulatory mechanisms for low metabolic activity remain unknown. Here, we showed that low pyruvate levels are present in the brains of diapause-destined pupae of the cotton bollworm Helicoverpa armigera, and three enzymes pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and phosphoglycerate mutase (PGAM) are closely correlated with pyruvate homeostasis. Notably, Sirt2 can deacetylate the three enzymes to increase their activity in vitro. Thus, low Sirt2 expression in the brains of diapause individuals decreases PK and PEPCK protein levels as well as PGAM activity, resulting in low pyruvate levels and low tricarboxylic acid cycle activity and eventually inducing diapause initiation by low metabolic activity. These findings suggest that pyruvate is a checkpoint for development or lifespan extension, and Sirt2 is a negative regulator to extend lifespan in insects.
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74
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Kemis JH, Linke V, Barrett KL, Boehm FJ, Traeger LL, Keller MP, Rabaglia ME, Schueler KL, Stapleton DS, Gatti DM, Churchill GA, Amador-Noguez D, Russell JD, Yandell BS, Broman KW, Coon JJ, Attie AD, Rey FE. Genetic determinants of gut microbiota composition and bile acid profiles in mice. PLoS Genet 2019; 15:e1008073. [PMID: 31465442 PMCID: PMC6715156 DOI: 10.1371/journal.pgen.1008073] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/14/2019] [Indexed: 02/03/2023] Open
Abstract
The microbial communities that inhabit the distal gut of humans and other mammals exhibit large inter-individual variation. While host genetics is a known factor that influences gut microbiota composition, the mechanisms underlying this variation remain largely unknown. Bile acids (BAs) are hormones that are produced by the host and chemically modified by gut bacteria. BAs serve as environmental cues and nutrients to microbes, but they can also have antibacterial effects. We hypothesized that host genetic variation in BA metabolism and homeostasis influence gut microbiota composition. To address this, we used the Diversity Outbred (DO) stock, a population of genetically distinct mice derived from eight founder strains. We characterized the fecal microbiota composition and plasma and cecal BA profiles from 400 DO mice maintained on a high-fat high-sucrose diet for ~22 weeks. Using quantitative trait locus (QTL) analysis, we identified several genomic regions associated with variations in both bacterial and BA profiles. Notably, we found overlapping QTL for Turicibacter sp. and plasma cholic acid, which mapped to a locus containing the gene for the ileal bile acid transporter, Slc10a2. Mediation analysis and subsequent follow-up validation experiments suggest that differences in Slc10a2 gene expression associated with the different strains influences levels of both traits and revealed novel interactions between Turicibacter and BAs. This work illustrates how systems genetics can be utilized to generate testable hypotheses and provide insight into host-microbe interactions.
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Affiliation(s)
- Julia H. Kemis
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Vanessa Linke
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Kelsey L. Barrett
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Frederick J. Boehm
- Department of Statistics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Lindsay L. Traeger
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Mark P. Keller
- Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Mary E. Rabaglia
- Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Kathryn L. Schueler
- Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Donald S. Stapleton
- Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Daniel M. Gatti
- Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Daniel Amador-Noguez
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Jason D. Russell
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Brian S. Yandell
- Department of Statistics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Karl W. Broman
- Department of Biostatistics and Medical Informatics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Joshua J. Coon
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- Morgridge Institute for Research, Madison, Wisconsin, United States of America
- Department of Biomolecular Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Federico E. Rey
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
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75
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Abulizi A, Camporez JP, Jurczak MJ, Høyer KF, Zhang D, Cline GW, Samuel VT, Shulman GI, Vatner DF. Adipose glucocorticoid action influences whole-body metabolism via modulation of hepatic insulin action. FASEB J 2019; 33:8174-8185. [PMID: 30922125 PMCID: PMC6593882 DOI: 10.1096/fj.201802706r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/18/2019] [Indexed: 12/14/2022]
Abstract
The connection between adipose glucocorticoid action and whole-body metabolism is incompletely understood. Thus, we generated adipose tissue-specific glucocorticoid receptor-knockout (Ad-GcR-/-) mice to explore potential mechanisms. Ad-GcR-/- mice had a lower concentration of fasting plasma nonesterified fatty acids and less hepatic steatosis. This was associated with increased protein kinase B phosphorylation and increased hepatic glycogen synthesis after an oral glucose challenge. High-fat diet (HFD)-fed Ad-GcR-/- mice were protected against the development of hepatic steatosis and diacylglycerol-PKCε-induced impairments in hepatic insulin signaling. Under hyperinsulinemic-euglycemic conditions, hepatic insulin response was ∼10-fold higher in HFD-fed Ad-GcR-/- mice. Insulin-mediated suppression of adipose lipolysis was improved by 40% in Ad-GcR-/- mice. Adipose triglyceride lipase expression was decreased and insulin-mediated perilipin dephosphorylation was increased in Ad-GcR-/- mice. In metabolic cages, food intake decreased by 3 kcal/kg per hour in Ad-GcR-/- mice. Therefore, physiologic adipose glucocorticoid action appears to drive hepatic lipid accumulation during stressors such as fasting. The resultant hepatic insulin resistance prevents hepatic glycogen synthesis, preserving glucose for glucose-dependent organs. Absence of adipose glucocorticoid action attenuates HFD-induced hepatic insulin resistance; potential explanations for reduction in hepatic steatosis include reductions in adipose lipolysis and food intake.-Abulizi, A., Camporez, J.-P., Jurczak, M. J., Høyer, K. F., Zhang, D., Cline, G. W., Samuel, V. T., Shulman, G. I., Vatner, D. F. Adipose glucocorticoid action influences whole-body metabolism via modulation of hepatic insulin action.
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Affiliation(s)
- Abudukadier Abulizi
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - João-Paulo Camporez
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Michael J. Jurczak
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kasper F. Høyer
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Clinical Medicine, Magnetic Resonance Research Centre, Aarhus University, Aarhus, Denmark
| | - Dongyan Zhang
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gary W. Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Varman T. Samuel
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Veterans Affairs Medical Center, West Haven, Connecticut, USA
| | - Gerald I. Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Daniel F. Vatner
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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Zhang T, Qi Z, Wang H, Ding S. Adeno-Associated Virus-Mediated Knockdown of SLC16A11 Improves Glucose Tolerance and Hepatic Insulin Signaling in High Fat Diet-Fed Mice. Exp Clin Endocrinol Diabetes 2019; 129:104-111. [PMID: 31185508 DOI: 10.1055/a-0840-3330] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND SLC16A11, a member of the SLC16 family, is associated with lipid metabolism, causing increased intracellular triacylglycerol (TAG) levels. In the current study, our primary goal was to determine if an SLC16A11 knockdown would improve glucose tolerance and hepatic insulin signaling in high fat diet (HFD)-fed mice. Additionally, the mechanism for exercise-improved insulin sensitivity remains unclear, and there is no mechanistic insight into SLC16A11's role in insulin sensitivity under exercise stress. Therefore, we also examined the impact of endurance exercise on the abundance of SLC16A11. METHODS C57BL/6 J male mice were fed either regular chow (Control) or HFD for 8 weeks and then injected with adeno-associated virus (AAV). Plasma parameters, tissue lipid contents, glucose tolerance, and expression profiles of hepatic insulin signaling were detected. Also, other mice were divided randomly into sedentary and exercise groups. We assessed hepatic expression of SLC16A11 after 8 weeks of endurance exercise. RESULTS 1) Hepatic SLC16A11 expression was greater in HFD-fed mice compared to Control mice. 2) AAV-mediated knockdown of SLC16A11 improved glucose tolerance, prevented TAG accumulation in serum and liver, and increased phosphorylation of protein kinase B (Akt) and glycogen synthesis kinase-3β (GSK3β) in HFD-fed mice. 3) Endurance exercise decreased hepatic SLC16A11 expression. CONCLUSIONS Inactivation of SLC16A11, which is robustly induced by HFD, improved glucose tolerance and hepatic insulin signaling, independent of body weight, but related to TAG. Additionally, SLC16A11 might mediate the health benefits of endurance exercise.
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Affiliation(s)
- Tan Zhang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education, East China Normal University, Shanghai, China.,College of Physical Education and Health, East China Normal University, Shanghai, China
| | - Zhengtang Qi
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education, East China Normal University, Shanghai, China.,College of Physical Education and Health, East China Normal University, Shanghai, China
| | - Haiyan Wang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education, East China Normal University, Shanghai, China.,College of Physical Education and Health, East China Normal University, Shanghai, China
| | - Shuzhe Ding
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education, East China Normal University, Shanghai, China.,College of Physical Education and Health, East China Normal University, Shanghai, China
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77
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Structure and Mechanism of the Divalent Anion/Na⁺ Symporter. Int J Mol Sci 2019; 20:ijms20020440. [PMID: 30669552 PMCID: PMC6359215 DOI: 10.3390/ijms20020440] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 12/22/2022] Open
Abstract
Integral membrane proteins of the divalent anion/Na⁺ symporter (DASS) family are conserved from bacteria to humans. DASS proteins typically mediate the coupled uptake of Na⁺ ions and dicarboxylate, tricarboxylate, or sulfate. Since the substrates for DASS include key intermediates and regulators of energy metabolism, alterations of DASS function profoundly affect fat storage, energy expenditure and life span. Furthermore, loss-of-function mutations in a human DASS have been associated with neonatal epileptic encephalopathy. More recently, human DASS has also been implicated in the development of liver cancers. Therefore, human DASS proteins are potentially promising pharmacological targets for battling obesity, diabetes, kidney stone, fatty liver, as well as other metabolic and neurological disorders. Despite its clinical relevance, the mechanism by which DASS proteins recognize and transport anionic substrates remains unclear. Recently, the crystal structures of a bacterial DASS and its humanized variant have been published. This article reviews the mechanistic implications of these structures and suggests future work to better understand how the function of DASS can be modulated for potential therapeutic benefit.
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78
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Analysis of naturally occurring mutations in the human uptake transporter NaCT important for bone and brain development and energy metabolism. Sci Rep 2018; 8:11330. [PMID: 30054523 PMCID: PMC6063891 DOI: 10.1038/s41598-018-29547-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 07/13/2018] [Indexed: 11/30/2022] Open
Abstract
The human uptake transporter NaCT is important for human brain development, brain function and energy metabolism and mediates the uptake of citrate and other intermediates of the tricarboxylic acid cycle from blood into neurons and hepatocytes. Mutations in the SLC13A5 gene encoding NaCT are associated with epileptic encephalopathy. To gain more insights into the transport mechanisms we analyzed the functional consequences of mutations in the SLC13A5 gene on NaCT-mediated transport function. Using HEK293 cells expressing wild-type and eight mutated NaCT proteins, we investigated the mRNA and protein amount as well as the protein localization of all NaCT variants. Furthermore, the impact on NaCT-mediated citrate uptake was measured. In addition, a structural model of the transport pore was generated to rationalize the consequences of the mutations on a structural basis. We demonstrated that all proteins were synthesized with an identical molecular weight as the wild-type transporter but several mutations (NaCTp.G219R, −p.G219E, −p.T227M, −p.L420P and −p.L488P) lead to a complete loss of NaCT-mediated citrate transport. This loss of transport activity can be explained on the basis of the developed structural model. This model may help in the further elucidation of the transport mechanism of this important uptake transporter.
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79
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Wang Y, Moussian B, Schaeffeler E, Schwab M, Nies AT. The fruit fly Drosophila melanogaster as an innovative preclinical ADME model for solute carrier membrane transporters, with consequences for pharmacology and drug therapy. Drug Discov Today 2018; 23:1746-1760. [PMID: 29890226 DOI: 10.1016/j.drudis.2018.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/13/2018] [Accepted: 06/04/2018] [Indexed: 12/31/2022]
Abstract
Solute carrier membrane transporters (SLCs) control cell exposure to small-molecule drugs, thereby contributing to drug efficacy and failure and/or adverse effects. Moreover, SLCs are genetically linked to various diseases. Hence, in-depth knowledge of SLC function is fundamental for a better understanding of disease pathophysiology and the drug development process. Given that the model organism Drosophila melanogaster (fruit fly) expresses SLCs, such as for the excretion of endogenous and toxic compounds by the hindgut and Malpighian tubules, equivalent to human intestine and kidney, this system appears to be a promising preclinical model to use to study human SLCs. Here, we systematically compare current knowledge of SLCs in Drosophila and humans and describe the Drosophila model as an innovative tool for drug development.
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Affiliation(s)
- Yiwen Wang
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany; Animal Genetics, University of Tübingen, Germany
| | - Bernard Moussian
- Animal Genetics, University of Tübingen, Germany; Université Côte d'Azur, CNRS, INSERM, iBV, Nice, France; Applied Zoology, TU Dresden, Germany
| | - Elke Schaeffeler
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany; University of Tübingen, Tübingen, Germany
| | - Matthias Schwab
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany; University of Tübingen, Tübingen, Germany; Department of Clinical Pharmacology, University Hospital Tübingen, Tübingen, Germany; Department of Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany.
| | - Anne T Nies
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany; University of Tübingen, Tübingen, Germany
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80
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Phokrai P, Poolsri W, Suwankulanan S, Phakdeeto N, Kaewkong W, Pekthong D, Richert L, Srisawang P. Suppressed de novo lipogenesis by plasma membrane citrate transporter inhibitor promotes apoptosis in HepG2 cells. FEBS Open Bio 2018; 8:986-1000. [PMID: 29928578 PMCID: PMC5986055 DOI: 10.1002/2211-5463.12435] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/03/2018] [Accepted: 04/18/2018] [Indexed: 01/02/2023] Open
Abstract
Suppression of the expression or activities of enzymes that are involved in the synthesis of de novo lipogenesis (DNL) in cancer cells triggers cell death via apoptosis. The plasma membrane citrate transporter (PMCT) is the initial step that translocates citrate from blood circulation into the cytoplasm for de novo long-chain fatty acids synthesis. This study investigated the antitumor effect of the PMCT inhibitor (PMCTi) in inducing apoptosis by inhibiting the DNL pathway in HepG2 cells. The present findings showed that PMCTi reduced cell viability and enhanced apoptosis through decreased intracellular citrate levels, which consequently caused inhibition of fatty acid and triacylglycerol productions. Thus, as a result of the reduction in fatty acid synthesis, the activity of carnitine palmitoyl transferase-1 (CPT-1) was suppressed. Decreased CPT-1 activity also facilitated the disruption of mitochondrial membrane potential (ΔΨm) leading to stimulation of apoptosis. Surprisingly, primary human hepatocytes were not affected by PMCTi. Increased caspase-8 activity as a consequence of reduction in fatty acid synthesis was also found to cause disruption of ΔΨm. In addition, apoptosis induction by PMCTi was associated with an enhanced reactive oxygen species generation. Taken together, we suggest that inhibition of the DNL pathway following reduction in citrate levels is an important regulator of apoptosis in HepG2 cells via suppression of CPT-1 activity. Thus, targeting the DNL pathway mediating CPT-1 activity by PMCTi may be a selective potential anticancer therapy.
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Affiliation(s)
- Phornpun Phokrai
- Department of Medical TechnologyFaculty of Science and TechnologyBansomdejchaopraya Rajabhat UniversityBangkokThailand
| | - Wan‐angkan Poolsri
- Department of PhysiologyFaculty of Medical ScienceNaresuan UniversityPhitsanulokThailand
| | - Somrudee Suwankulanan
- Department of PhysiologyFaculty of Medical ScienceNaresuan UniversityPhitsanulokThailand
| | - Narinthorn Phakdeeto
- Department of PhysiologyFaculty of Medical ScienceNaresuan UniversityPhitsanulokThailand
| | - Worasak Kaewkong
- Department of BiochemistryFaculty of Medical ScienceNaresuan UniversityPhitsanulokThailand
| | - Dumrongsak Pekthong
- Department of Pharmacy PracticeFaculty of Pharmaceutical SciencesNaresuan UniversityPhitsanulokThailand
| | | | - Piyarat Srisawang
- Department of PhysiologyFaculty of Medical ScienceNaresuan UniversityPhitsanulokThailand
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81
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Willmes DM, Kurzbach A, Henke C, Schumann T, Zahn G, Heifetz A, Jordan J, Helfand SL, Birkenfeld AL. The longevity gene INDY ( I 'm N ot D ead Y et) in metabolic control: Potential as pharmacological target. Pharmacol Ther 2018; 185:1-11. [DOI: 10.1016/j.pharmthera.2017.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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82
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Srivastava A, Singh S, Rajpurohit CS, Srivastava P, Pandey A, Kumar D, Khanna VK, Pant AB. Secretome of Differentiated PC12 Cells Restores the Monocrotophos-Induced Damages in Human Mesenchymal Stem Cells and SHSY-5Y Cells: Role of Autophagy and Mitochondrial Dynamics. Neuromolecular Med 2018; 20:233-251. [PMID: 29603067 DOI: 10.1007/s12017-018-8487-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/28/2018] [Indexed: 12/16/2022]
Abstract
A perturbed cellular homeostasis is a key factor associated with xenobiotic exposure resulting in various ailments. The local cellular microenvironment enriched with secretory components aids in cell-cell communication that restores this homeostasis. Deciphering the underlying mechanism behind this restorative potential of secretome could serve as a possible solution to many health hazards. We, therefore, explored the protective efficacy of the secretome of differentiated PC12 cells with emphasis on induction of autophagy and mitochondrial biogenesis. Monocrotophos (MCP), a widely used neurotoxic organophosphate, was used as the test compound at sublethal concentration. The conditioned medium (CM) of differentiated PC12 cells comprising of their secretome restored the cell viability, oxidative stress and apoptotic cell death in MCP-challenged human mesenchymal stem cells and SHSY-5Y, a human neuroblastoma cell line. Delving further to identify the underlying mechanism of this restorative effect we observed a marked increase in the expression of autophagy markers LC3, Beclin-1, Atg5 and Atg7. Exposure to autophagy inhibitor, 3-methyladenine, led to a reduced expression of these markers with a concomitant increase in the expression of pro-apoptotic caspase-3. Besides that, the increased mitochondrial fission in MCP-exposed cells was balanced with increased fusion in the presence of CM facilitated by AMPK/SIRT1/PGC-1α signaling cascade. Mitochondrial dysfunctions are strongly associated with autophagy activation and as per our findings, cellular secretome too induces autophagy. Therefore, connecting these three potential apices can be a major breakthrough in repair and rescue of xenobiotic-damaged tissues and cells.
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Affiliation(s)
- A Srivastava
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
| | - S Singh
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India
| | - C S Rajpurohit
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India
| | - P Srivastava
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
| | - A Pandey
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
| | - D Kumar
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India
| | - V K Khanna
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India
| | - A B Pant
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India.
- Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India.
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83
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Ogura J, Babu E, Miyauchi S, Ramachandran S, Nemeth E, Bhutia YD, Ganapathy V. Identification of a novel Na +-coupled Fe 3+-citrate transport system, distinct from mammalian INDY, for uptake of citrate in mammalian cells. Sci Rep 2018; 8:2519. [PMID: 29410496 PMCID: PMC5802838 DOI: 10.1038/s41598-018-20620-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/22/2018] [Indexed: 01/05/2023] Open
Abstract
NaCT is a Na+-coupled transporter for citrate expressed in hepatocytes and neurons. It is the mammalian ortholog of INDY (I’m Not Dead Yet), a transporter which modifies lifespan in Drosophila. Here we describe a hitherto unknown transport system for citrate in mammalian cells. When liver and mammary epithelial cells were pretreated with the iron supplement ferric ammonium citrate (FAC), uptake of citrate increased >10-fold. Iron chelators abrogated the stimulation of citrate uptake in FAC-treated cells. The iron exporter ferroportin had no role in this process. The stimulation of citrate uptake also occurred when Fe3+ was added during uptake without pretreatment. Similarly, uptake of Fe3+ was enhanced by citrate. The Fe3+-citrate uptake was coupled to Na+. This transport system was detectable in primary hepatocytes and neuronal cell lines. The functional features of this citrate transport system distinguish it from NaCT. Loss-of-function mutations in NaCT cause early-onset epilepsy and encephalopathy; the newly discovered Na+-coupled Fe3+-citrate transport system might offer a novel treatment strategy for these patients to deliver citrate into affected neurons independent of NaCT. It also has implications to iron-overload conditions where circulating free iron increases, which would stimulate cellular uptake of citrate and consequently affect multiple metabolic pathways.
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Affiliation(s)
- Jiro Ogura
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA
| | - Ellappan Babu
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA
| | - Seiji Miyauchi
- Department of Pharmaceutics, Toho University, Funabashi, Chiba, 274-8510, Japan
| | - Sabarish Ramachandran
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA
| | - Elizebeta Nemeth
- Department of Medicine and Center for Iron Disorders, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Yangzom D Bhutia
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA
| | - Vadivel Ganapathy
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA.
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84
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Combination of Mitochondrial and Plasma Membrane Citrate Transporter Inhibitors Inhibits De Novo Lipogenesis Pathway and Triggers Apoptosis in Hepatocellular Carcinoma Cells. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3683026. [PMID: 29546056 PMCID: PMC5818947 DOI: 10.1155/2018/3683026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/23/2017] [Accepted: 12/03/2017] [Indexed: 12/27/2022]
Abstract
Increased expression levels of both mitochondrial citrate transporter (CTP) and plasma membrane citrate transporter (PMCT) proteins have been found in various cancers. The transported citrates by these two transporter proteins provide acetyl-CoA precursors for the de novo lipogenesis (DNL) pathway to support a high rate of cancer cell viability and development. Inhibition of the DNL pathway promotes cancer cell apoptosis without apparent cytotoxic to normal cells, leading to the representation of selective and powerful targets for cancer therapy. The present study demonstrates that treatments with CTP inhibitor (CTPi), PMCT inhibitor (PMCTi), and the combination of CTPi and PMCTi resulted in decreased cell viability in two hepatocellular carcinoma cell lines (HepG2 and HuH-7). Treatment with citrate transporter inhibitors caused a greater cytotoxic effect in HepG2 cells than in HuH-7 cells. A lower concentration of combined CTPi and PMCTi promotes cytotoxic effect compared with either of a single compound. An increased cell apoptosis and an induced cell cycle arrest in both cell lines were reported after administration of the combined inhibitors. A combination treatment exhibits an enhanced apoptosis through decreased intracellular citrate levels, which consequently cause inhibition of fatty acid production in HepG2 cells. Apoptosis induction through the mitochondrial-dependent pathway was found as a consequence of suppressed carnitine palmitoyl transferase-1 (CPT-1) activity and enhanced ROS generation by combined CTPi and PMCTi treatment. We showed that accumulation of malonyl-CoA did not correlate with decreasing CPT-1 activity. The present study showed that elevated ROS levels served as an inhibition on Bcl-2 activity that is at least in part responsible for apoptosis. Moreover, inhibition of the citrate transporter is selectively cytotoxic to HepG2 cells but not in primary human hepatocytes, supporting citrate-mediating fatty acid synthesis as a promising cancer therapy.
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85
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Salminen A, Kaarniranta K, Kauppinen A. Regulation of longevity by FGF21: Interaction between energy metabolism and stress responses. Ageing Res Rev 2017; 37:79-93. [PMID: 28552719 DOI: 10.1016/j.arr.2017.05.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/28/2017] [Accepted: 05/18/2017] [Indexed: 12/11/2022]
Abstract
Fibroblast growth factor 21 (FGF21) is a hormone-like member of FGF family which controls metabolic multiorgan crosstalk enhancing energy expenditure through glucose and lipid metabolism. In addition, FGF21 acts as a stress hormone induced by endoplasmic reticulum stress and dysfunctions of mitochondria and autophagy in several tissues. FGF21 also controls stress responses and metabolism by modulating the functions of somatotropic axis and hypothalamic-pituitary-adrenal (HPA) pathway. FGF21 is a potent longevity factor coordinating interactions between energy metabolism and stress responses. Recent studies have revealed that FGF21 treatment can alleviate many age-related metabolic disorders, e.g. atherosclerosis, obesity, type 2 diabetes, and some cardiovascular diseases. In addition, transgenic mice overexpressing FGF21 have an extended lifespan. However, chronic metabolic and stress-related disorders involving inflammatory responses can provoke FGF21 resistance and thus disturb healthy aging process. First, we will describe the role of FGF21 in interorgan energy metabolism and explain how its functions as a stress hormone can improve healthspan. Next, we will examine both the induction of FGF21 expression via the integrated stress response and the molecular mechanism through which FGF21 enhances healthy aging. Finally, we postulate that FGF21 resistance, similarly to insulin resistance, jeopardizes human healthspan and accelerates the aging process.
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86
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Bainbridge MN, Cooney E, Miller M, Kennedy AD, Wulff JE, Donti T, Jhangiani SN, Gibbs RA, Elsea SH, Porter BE, Graham BH. Analyses of SLC13A5-epilepsy patients reveal perturbations of TCA cycle. Mol Genet Metab 2017; 121:314-319. [PMID: 28673551 PMCID: PMC7539367 DOI: 10.1016/j.ymgme.2017.06.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 01/16/2023]
Abstract
OBJECTIVE To interrogate the metabolic profile of five subjects from three families with rare, nonsense and missense mutations in SLC13A5 and Early Infantile Epileptic Encephalopathies (EIEE) characterized by severe, neonatal onset seizures, psychomotor retardation and global developmental delay. METHODS Mass spectrometry of plasma, CSF and urine was used to identify consistently dysregulated analytes in our subjects. RESULTS Distinctive elevations of citrate and dysregulation of citric acid cycle intermediates, supporting the hypothesis that loss of SLC13A5 function alters tricarboxylic acid cycle (TCA) metabolism and may disrupt metabolic compartmentation in the brain. SIGNIFICANCE Our results indicate that analysis of plasma citrate and other TCA analytes in SLC13A5 deficient patients define a diagnostic metabolic signature that can aid in diagnosing children with this disease.
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Affiliation(s)
- Matthew N Bainbridge
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States; Codified Genomics LLC, Houston, TX, United States; Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, United States
| | - Erin Cooney
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Marcus Miller
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | | | | | - Taraka Donti
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Sarah H Elsea
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Brenda E Porter
- Department of Neurology, Stanford University Medical School, Palo Alto, CA, United States
| | - Brett H Graham
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.
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87
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von Loeffelholz C, Lieske S, Neuschäfer-Rube F, Willmes DM, Raschzok N, Sauer IM, König J, Fromm M, Horn P, Chatzigeorgiou A, Pathe-Neuschäfer-Rube A, Jordan J, Pfeiffer AFH, Mingrone G, Bornstein SR, Stroehle P, Harms C, Wunderlich FT, Helfand SL, Bernier M, de Cabo R, Shulman GI, Chavakis T, Püschel GP, Birkenfeld AL. The human longevity gene homolog INDY and interleukin-6 interact in hepatic lipid metabolism. Hepatology 2017; 66:616-630. [PMID: 28133767 PMCID: PMC5519435 DOI: 10.1002/hep.29089] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 12/15/2016] [Accepted: 01/19/2017] [Indexed: 12/17/2022]
Abstract
UNLABELLED Reduced expression of the Indy ("I am Not Dead, Yet") gene in lower organisms promotes longevity in a manner akin to caloric restriction. Deletion of the mammalian homolog of Indy (mIndy, Slc13a5) encoding for a plasma membrane-associated citrate transporter expressed highly in the liver, protects mice from high-fat diet-induced and aging-induced obesity and hepatic fat accumulation through a mechanism resembling caloric restriction. We studied a possible role of mIndy in human hepatic fat metabolism. In obese, insulin-resistant patients with nonalcoholic fatty liver disease, hepatic mIndy expression was increased and mIndy expression was also independently associated with hepatic steatosis. In nonhuman primates, a 2-year high-fat, high-sucrose diet increased hepatic mIndy expression. Liver microarray analysis showed that high mIndy expression was associated with pathways involved in hepatic lipid metabolism and immunological processes. Interleukin-6 (IL-6) was identified as a regulator of mIndy by binding to its cognate receptor. Studies in human primary hepatocytes confirmed that IL-6 markedly induced mIndy transcription through the IL-6 receptor and activation of the transcription factor signal transducer and activator of transcription 3, and a putative start site of the human mIndy promoter was determined. Activation of the IL-6-signal transducer and activator of transcription 3 pathway stimulated mIndy expression, enhanced cytoplasmic citrate influx, and augmented hepatic lipogenesis in vivo. In contrast, deletion of mIndy completely prevented the stimulating effect of IL-6 on citrate uptake and reduced hepatic lipogenesis. These data show that mIndy is increased in liver of obese humans and nonhuman primates with NALFD. Moreover, our data identify mIndy as a target gene of IL-6 and determine novel functions of IL-6 through mINDY. CONCLUSION Targeting human mINDY may have therapeutic potential in obese patients with nonalcoholic fatty liver disease. German Clinical Trials Register: DRKS00005450. (Hepatology 2017;66:616-630).
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Affiliation(s)
- Christian von Loeffelholz
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, and Department of Anesthesiology and Intensive Care, Jena University Hospital, Jena, 01774, Germany
| | - Stefanie Lieske
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Paul Langerhans Institute Dresden (PLID), TU Dresden,01307 Germany,Lehrstuhl für Biochemie der Ernährung, Universität Potsdam, Potsdam, 14558, Germany
| | | | - Diana M. Willmes
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Paul Langerhans Institute Dresden (PLID), TU Dresden,01307 Germany
| | - Nathanael Raschzok
- General, Visceral, and Transplantation Surgery, Charité – University School of Medicine, Berlin, 10117, Germany
| | - Igor M. Sauer
- General, Visceral, and Transplantation Surgery, Charité – University School of Medicine, Berlin, 10117, Germany
| | - Jörg König
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität, Erlangen-Nürnberg, 91054, Germany
| | - Martin Fromm
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität, Erlangen-Nürnberg, 91054, Germany
| | - Paul Horn
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, and Department of Anesthesiology and Intensive Care, Jena University Hospital, Jena, 01774, Germany
| | - Antonis Chatzigeorgiou
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, University Clinic Dresden, TUD, Germany
| | | | - Jens Jordan
- Institute for Clinical Pharmacology, Hannover Medical School, 30625 Hannover, Germany
| | - Andreas F. H. Pfeiffer
- Department of Endocrinology, Diabetes and Nutrition, Charité – University School of Medicine, Berlin, 10117, Germany,German Centre for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Geltrude Mingrone
- Division of Diabetes & Nutritional Sciences, Faculty of Life Sciences & Medicine, King’s College London, London SE1 8WA, UK,Catholic University of Rome, Department of Internal Medicine, Rome, Italy
| | - Stefan R. Bornstein
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Paul Langerhans Institute Dresden (PLID), TU Dresden,01307 Germany,Division of Diabetes & Nutritional Sciences, Faculty of Life Sciences & Medicine, King’s College London, London SE1 8WA, UK,German Centre for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Peter Stroehle
- Max Planck Institute for Metabolism Research, Excellence cluster on cellular stress responses in aging associated diseases (CECAD), Cologne, 5093, Germany
| | - Christoph Harms
- Charité-Universitätsmedizin Berlin, Center for Stroke Research, Department of Experimental Neurology, Charitéplatz 1, 10117 Berlin, Germany
| | - F. Thomas Wunderlich
- Max Planck Institute for Metabolism Research, Excellence cluster on cellular stress responses in aging associated diseases (CECAD), Cologne, 5093, Germany
| | - Stephen. L. Helfand
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Michel Bernier
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Gerald I. Shulman
- Department of Internal Medicine, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Triantafyllos Chavakis
- Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, University Clinic Dresden, TUD, Germany
| | - Gerhard. P. Püschel
- Lehrstuhl für Biochemie der Ernährung, Universität Potsdam, Potsdam, 14558, Germany
| | - Andreas. L. Birkenfeld
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Paul Langerhans Institute Dresden (PLID), TU Dresden,01307 Germany,Division of Diabetes & Nutritional Sciences, Faculty of Life Sciences & Medicine, King’s College London, London SE1 8WA, UK,German Centre for Diabetes Research (DZD e.V.), Neuherberg, Germany,Competence Center for Metabolic Vascular Medicine, GWT-TU Dresden, Germany,Contact Information: Andreas L. Birkenfeld, M.D., Section of Metabolic Vascular Medicine, Dresden University School of Medicine Germany, TU Dresden, Tel: +49 15119188884.
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88
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Shigiyama F, Kumashiro N, Furukawa Y, Funayama T, Takeno K, Wakui N, Ikehara T, Nagai H, Taka H, Fujimura T, Uchino H, Tamura Y, Watada H, Nemoto T, Shiraga N, Sumino Y, Hirose T. Characteristics of hepatic insulin-sensitive nonalcoholic fatty liver disease. Hepatol Commun 2017; 1:634-647. [PMID: 29404483 PMCID: PMC5721442 DOI: 10.1002/hep4.1077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/20/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) plays a crucial role in type 2 diabetes and hepatocellular carcinoma. The major underlying pathogenesis is hepatic insulin resistance. The aim of the present study was to characterize patients with NAFLD with paradoxically normal hepatic insulin sensitivity relative to patients with NAFLD with hepatic insulin resistance. We recruited 26 patients with NAFLD and divided them into three groups ranked by the level of hepatic insulin sensitivity (HIS; high‐HIS, mid‐HIS, low‐HIS), as assessed by the hyperinsulinemic‐euglycemic clamp studies using stable isotope. Hepatic insulin sensitivity of the high‐HIS group was identical to that of the non‐NAFLD lean control (clamped percent suppression of endogenous glucose production, 91.1% ± 5.2% versus 91.0% ± 8.5%, respectively) and was significantly higher than that of the low‐HIS group (66.6% ± 7.5%; P < 0.01). Adiposity (subcutaneous, visceral, intrahepatic, and muscular lipid content), hepatic histopathology, and expression levels of various genes by using liver biopsies, muscle, and adipose tissue insulin sensitivity, plasma metabolites by metabolomics analysis, putative biomarkers, and lifestyles were assessed and compared between the high‐HIS and low‐HIS groups. Among these, adipose tissue insulin sensitivity assessed by clamped percent suppression of free fatty acid, serum high molecular weight adiponectin, and plasma tricarboxylic acid cycle metabolites, such as citric acid and cis‐aconitic acid, were significantly higher in the high‐HIS group compared to the low‐HIS group. In contrast, there were no differences in adiposity, including intrahepatic lipid content assessed by proton magnetic resonance spectroscopy (28.3% ± 16.1% versus 20.4% ± 9.9%, respectively), hepatic histopathology, other putative biomarkers, and lifestyles. Conclusion: High levels of adipose tissue insulin sensitivity, serum high molecular weight adiponectin, and plasma tricarboxylic acid cycle metabolites are unique characteristics that define patients with hepatic insulin‐sensitive NAFLD regardless of intrahepatic lipid content. (Hepatology Communications 2017;1:634–647)
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Affiliation(s)
- Fumika Shigiyama
- Division of Diabetes Metabolism, and Endocrinology, Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Naoki Kumashiro
- Division of Diabetes Metabolism, and Endocrinology, Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Yasuhiko Furukawa
- Department of Metabolism and Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan
| | - Takashi Funayama
- Department of Metabolism and Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan
| | - Kageumi Takeno
- Department of Metabolism and Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan
| | - Noritaka Wakui
- Division of Gastroenterology and Hepatology Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Takashi Ikehara
- Division of Gastroenterology and Hepatology Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Hidenari Nagai
- Division of Gastroenterology and Hepatology Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Hikari Taka
- Laboratory of Proteomics and Biomolecular Science Research Support Center, Juntendo University Graduate School of Medicine Tokyo Japan
| | - Tsutomu Fujimura
- Laboratory of Bioanalytical Chemistry Tohoku Medical and Pharmaceutical University Sendai Japan
| | - Hiroshi Uchino
- Division of Diabetes Metabolism, and Endocrinology, Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Yoshifumi Tamura
- Department of Metabolism and Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.,Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan
| | - Hirotaka Watada
- Department of Metabolism and Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.,Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan
| | - Tetsuo Nemoto
- Department of Surgical Pathology Toho University Graduate School of Medicine Tokyo Japan
| | - Nobuyuki Shiraga
- Department of Radiology Toho University Graduate School of Medicine Tokyo Japan
| | - Yasukiyo Sumino
- Division of Gastroenterology and Hepatology Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
| | - Takahisa Hirose
- Division of Diabetes Metabolism, and Endocrinology, Department of Medicine, Toho University Graduate School of Medicine Tokyo Japan
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89
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Li Z, Li D, Choi EY, Lapidus R, Zhang L, Huang SM, Shapiro P, Wang H. Silencing of solute carrier family 13 member 5 disrupts energy homeostasis and inhibits proliferation of human hepatocarcinoma cells. J Biol Chem 2017; 292:13890-13901. [PMID: 28655760 DOI: 10.1074/jbc.m117.783860] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/23/2017] [Indexed: 12/22/2022] Open
Abstract
The solute carrier family 13 member 5 (SLC13A5), a sodium-coupled citrate transporter, plays a key role in importing citrate from the circulation into liver cells. Recent evidence has revealed that SLC13A5 deletion protects mice from high-fat diet-induced hepatic steatosis and that mutation of the SLC13A5 orthologues in Drosophila melanogaster and Caenorhabditis elegans promotes longevity. However, despite the emerging importance of SLC13A5 in energy homeostasis, whether perturbation of SLC13A5 affects the metabolism and malignancy of hepatocellular carcinoma is unknown. Here, we sought to determine whether SLC13A5 regulates hepatic energy homeostasis and proliferation of hepatoma cells. RNAi-mediated silencing of SLC13A5 expression in two human hepatoma cell lines, HepG2 and Huh7, profoundly suppressed cell proliferation and colony formation, and induced cell cycle arrest accompanied by increased expression of cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin B1. Furthermore, such suppressive effects were also observed on the growth of HepG2 cell-derived xenografts expressing SLC13A5-shRNA in nude mice. Metabolically, knockdown of SLC13A5 in HepG2 and Huh7 cells was associated with a decrease in intracellular levels of citrate, the ratio of ATP/ADP, phospholipid content, and ATP citrate lyase expression. Moreover, both in vitro and in vivo assays demonstrated that SLC13A5 depletion promotes activation of the AMP-activated protein kinase, which was accompanied by deactivation of oncogenic mechanistic target of rapamycin signaling. Together, our findings expand the role of SLC13A5 from facilitating hepatic energy homeostasis to influencing hepatoma cell proliferation and suggest a potential role of SLC13A5 in the progression of human hepatocellular carcinoma.
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Affiliation(s)
- Zhihui Li
- From the Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201
| | - Daochuan Li
- From the Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201
| | - Eun Yong Choi
- the Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Rena Lapidus
- the Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Lei Zhang
- the Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, Maryland 20993
| | - Shiew-Mei Huang
- the Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, Maryland 20993
| | - Paul Shapiro
- From the Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201.,the Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Hongbing Wang
- From the Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, .,the Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
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90
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Rathjen T, Yan X, Kononenko NL, Ku MC, Song K, Ferrarese L, Tarallo V, Puchkov D, Kochlamazashvili G, Brachs S, Varela L, Szigeti-Buck K, Yi CX, Schriever SC, Tattikota SG, Carlo AS, Moroni M, Siemens J, Heuser A, van der Weyden L, Birkenfeld AL, Niendorf T, Poulet JFA, Horvath TL, Tschöp MH, Heinig M, Trajkovski M, Haucke V, Poy MN. Regulation of body weight and energy homeostasis by neuronal cell adhesion molecule 1. Nat Neurosci 2017. [PMID: 28628102 PMCID: PMC5533218 DOI: 10.1038/nn.4590] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Susceptibility to obesity is linked to genes regulating neurotransmission, pancreatic β-cell function, and energy homeostasis. Genome-wide association studies identified an association between body mass index and two loci near Cell Adhesion Molecule1 (CADM1) and Cell Adhesion Molecule2 (CADM2), genes encoding membrane proteins mediating synaptic assembly. We show these respective risk variants associate with increased CADM1 and CADM2 expression in the hypothalamus of human subjects. Expression of both genes is elevated in obese mice and induction of Cadm1 in excitatory neurons facilitated weight gain while exacerbating energy expenditure. Loss of Cadm1 protected mice from obesity and tract-tracing analysis revealed Cadm1-positive innervation of POMC neurons via afferent projections originating from beyond the arcuate nucleus. Reducing Cadm1 expression in the hypothalamus and hippocampus promoted a negative energy balance and weight loss. These data identify roles for Cadm1-mediated neuronal input in weight regulation and provide insight into the central pathways contributing to human obesity.
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Affiliation(s)
- Thomas Rathjen
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Xin Yan
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Natalia L Kononenko
- Leibniz Institute for Molecular Pharmacology, Berlin, Germany.,CECAD Research Center, University of Cologne, Cologne, Germany.,Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Min-Chi Ku
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Kun Song
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Leiron Ferrarese
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Valentina Tarallo
- University of Geneva, Medical Faculty, Department of Cell Physiology and Metabolism, Centre Médical Universitaire (CMU), Geneva, Switzerland
| | - Dmytro Puchkov
- Leibniz Institute for Molecular Pharmacology, Berlin, Germany
| | | | - Sebastian Brachs
- Charité - Universitätsmedizin Berlin, Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Berlin, Germany
| | - Luis Varela
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Klara Szigeti-Buck
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Chun-Xia Yi
- Institute for Diabetes and Obesity, Helmholtz Centre for Health and Environment and Division of Metabolic Diseases, Technical University Munich, Munich, Germany
| | - Sonja C Schriever
- Institute for Diabetes and Obesity, Helmholtz Centre for Health and Environment and Division of Metabolic Diseases, Technical University Munich, Munich, Germany
| | | | | | - Mirko Moroni
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jan Siemens
- Department of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Arnd Heuser
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Louise van der Weyden
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Andreas L Birkenfeld
- Section of Metabolic Vascular Medicine and Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Medical Clinic III, University Clinic Dresden, Dresden, Germany.,Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Thoralf Niendorf
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - James F A Poulet
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Anatomy and Histology, University of Veterinary Sciences, Budapest, Hungary
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Centre for Health and Environment and Division of Metabolic Diseases, Technical University Munich, Munich, Germany
| | - Matthias Heinig
- Helmholtz Zentrum München, Institute of Computational Biology, Neuherberg, Germany
| | - Mirko Trajkovski
- University of Geneva, Medical Faculty, Department of Cell Physiology and Metabolism, Centre Médical Universitaire (CMU), Geneva, Switzerland
| | - Volker Haucke
- Leibniz Institute for Molecular Pharmacology, Berlin, Germany.,Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Matthew N Poy
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
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91
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Rogina B. INDY-A New Link to Metabolic Regulation in Animals and Humans. Front Genet 2017; 8:66. [PMID: 28596784 PMCID: PMC5442177 DOI: 10.3389/fgene.2017.00066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 05/09/2017] [Indexed: 12/02/2022] Open
Abstract
The Indy (I’m Not Dead Yet) gene encodes the fly homolog of the mammalian SLC13A5 citrate transporter. Reduced expression of the Indy gene in flies and worms extends their longevity. INDY is expressed in the plasma membrane of metabolically active tissues. Decreased expression of Indy in worms, flies, mice, and rats alters metabolism in a manner similar to calorie restriction. Reducing INDY activity prevents weight gain in flies, worms, and mice, and counteracts the negative effects of age or a high fat diet on metabolism and insulin sensitivity. The metabolic effects of reducing INDY activity are the result of reduced cytoplasmic citrate. Citrate is a key metabolite and has a central role in energy status of the cell by effecting lipid and carbohydrate metabolism and energy production. Thereby newly described drugs that reduce INDY transporting activity increase insulin sensitivity and reduce hepatic lipid levels via its effect on hepatic citrate uptake. A recent report presented the first direct link between increased hepatic levels of human INDY, insulin resistance, and non-alcoholic fatty liver disease in obese humans. Similarly increased hepatic mIndy levels were observed in non-human primates fed on a high fat diet for 2 years. This effect is mediated via the stimulatory effect of the interleukin-6/Stat3 pathway on mINDY hepatic expression. These findings make INDY a potential and very promising target for the treatment of metabolic disorders in humans.
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Affiliation(s)
- Blanka Rogina
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, School of Medicine, University of Connecticut Health Center, FarmingtonCT, United States
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92
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Petersen MC, Shulman GI. Roles of Diacylglycerols and Ceramides in Hepatic Insulin Resistance. Trends Pharmacol Sci 2017; 38:649-665. [PMID: 28551355 DOI: 10.1016/j.tips.2017.04.004] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 12/22/2022]
Abstract
Although ample evidence links hepatic lipid accumulation with hepatic insulin resistance, the mechanistic basis of this association is incompletely understood and controversial. Diacylglycerols (DAGs) and ceramides have emerged as the two best-studied putative mediators of lipid-induced hepatic insulin resistance. Both lipids were first associated with insulin resistance in skeletal muscle and were subsequently hypothesized to mediate insulin resistance in the liver. However, the putative roles for DAGs and ceramides in hepatic insulin resistance have proved more complex than originally imagined, with various genetic and pharmacologic manipulations yielding a vast and occasionally contradictory trove of data to sort. In this review we examine the state of this field, turning a critical eye toward both DAGs and ceramides as putative mediators of lipid-induced hepatic insulin resistance.
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Affiliation(s)
- Max C Petersen
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Gerald I Shulman
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA.
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93
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Structure and function of the divalent anion/Na + symporter from Vibrio cholerae and a humanized variant. Nat Commun 2017; 8:15009. [PMID: 28436435 PMCID: PMC5413979 DOI: 10.1038/ncomms15009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/20/2017] [Indexed: 01/15/2023] Open
Abstract
Integral membrane proteins of the divalent anion/Na+ symporter (DASS) family translocate dicarboxylate, tricarboxylate or sulphate across cell membranes, typically by utilizing the preexisting Na+ gradient. The molecular determinants for substrate recognition by DASS remain obscure, largely owing to the absence of any substrate-bound DASS structure. Here we present 2.8-Å resolution X-ray structures of VcINDY, a DASS from Vibrio cholerae that catalyses the co-transport of Na+ and succinate. These structures portray the Na+-bound VcINDY in complexes with succinate and citrate, elucidating the binding sites for substrate and two Na+ ions. Furthermore, we report the structures of a humanized variant of VcINDY in complexes with succinate and citrate, which predict how a human citrate-transporting DASS may interact with its bound substrate. Our findings provide insights into metabolite transport by DASS, establishing a molecular basis for future studies on the regulation of this transport process. Divalent anion/Na+ symporter (DASS) transporters move intermediates of the Krebs cycle across the cell membrane. Here the authors present the substrate-bound structures of VcINDY, a DASS from Vibrio cholerae, which provide insights into the underlying transport mechanism.
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94
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Irizarry AR, Yan G, Zeng Q, Lucchesi J, Hamang MJ, Ma YL, Rong JX. Defective enamel and bone development in sodium-dependent citrate transporter (NaCT) Slc13a5 deficient mice. PLoS One 2017; 12:e0175465. [PMID: 28406943 PMCID: PMC5391028 DOI: 10.1371/journal.pone.0175465] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/27/2017] [Indexed: 01/08/2023] Open
Abstract
There has been growing recognition of the essential roles of citrate in biomechanical properties of mineralized tissues, including teeth and bone. However, the sources of citrate in these tissues have not been well defined, and the contribution of citrate to the regulation of odontogenesis and osteogenesis has not been examined. Here, tooth and bone phenotypes were examined in sodium-dependent citrate transporter (NaCT) Slc13a5 deficient C57BL/6 mice at 13 and 32 weeks of age. Slc13a5 deficiency led to defective tooth development, characterized by absence of mature enamel, formation of aberrant enamel matrix, and dysplasia and hyperplasia of the enamel organ epithelium that progressed with age. These abnormalities were associated with fragile teeth with a possible predisposition to tooth abscesses. The lack of mature enamel was consistent with amelogenesis imperfecta. Furthermore, Slc13a5 deficiency led to decreased bone mineral density and impaired bone formation in 13-week-old mice but not in older mice. The findings revealed the potentially important role of citrate and Slc13a5 in the development and function of teeth and bone.
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Affiliation(s)
- Armando R. Irizarry
- Department of Pathology, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, United States of America
- * E-mail: (JXR); (ARI)
| | - Guirui Yan
- Lilly China R&D Center, Eli Lilly & Company, Building 8, No. 338, Zhangjiang Hi-Tech Park, Shanghai, People’s Republic of China
| | - Qingqiang Zeng
- Musculoskeletal Research, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, United States of America
| | - Jonathan Lucchesi
- Musculoskeletal Research, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, United States of America
| | - Matthew J. Hamang
- Musculoskeletal Research, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, United States of America
| | - Yanfei L. Ma
- Musculoskeletal Research, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN, United States of America
| | - James Xiaojun Rong
- Lilly China R&D Center, Eli Lilly & Company, Building 8, No. 338, Zhangjiang Hi-Tech Park, Shanghai, People’s Republic of China
- * E-mail: (JXR); (ARI)
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95
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Díaz M, García C, Sebastiani G, de Zegher F, López-Bermejo A, Ibáñez L. Placental and Cord Blood Methylation of Genes Involved in Energy Homeostasis: Association With Fetal Growth and Neonatal Body Composition. Diabetes 2017; 66:779-784. [PMID: 27986832 DOI: 10.2337/db16-0776] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 12/09/2016] [Indexed: 11/13/2022]
Abstract
Low weight at birth is associated with subsequent susceptibility to diabetes. Epigenetic modulation is among the mechanisms potentially mediating this association. We performed a genome-wide DNA methylation analysis in placentas from term infants born appropriate-for-gestational-age (AGA) or small-for-gestational-age (SGA) to identify new genes related to fetal growth and neonatal body composition. Candidate genes were validated by bisulfite pyrosequencing (30 AGA, 21 SGA) and also analyzed in cord blood. Gene expression analyses were performed by RT-PCR. Neonatal body composition was assessed by dual X-ray absorptiometry at age 2 weeks. The ATG2B, NKX6.1, and SLC13A5 genes (respectively related to autophagy, β-cell development and function, and lipid metabolism) were hypermethylated in placenta and cord blood from SGA newborns, whereas GPR120 (related to free fatty acid regulation) was hypomethylated in placenta and hypermethylated in cord blood. Gene expression levels were opposite to methylation status, and both correlated with birth weight, circulating IGF-I, and total and abdominal fat at age 2 weeks. In conclusion, alterations in methylation and expression of genes involved in the regulation of energy homeostasis were found to relate to fetal growth and neonatal body composition and thus may be among the early mechanisms modulating later susceptibility to diabetes.
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Affiliation(s)
- Marta Díaz
- Institut Pediàtric, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina García
- Institut Pediàtric, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Giorgia Sebastiani
- Institut Pediàtric, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Francis de Zegher
- Department of Development and Regeneration, University of Leuven, Leuven, Belgium
| | - Abel López-Bermejo
- Department of Pediatrics, Dr. Josep Trueta Hospital, Girona, Spain
- Girona Institute for Biomedical Research, Girona, Spain
| | - Lourdes Ibáñez
- Institut Pediàtric, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
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96
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Plasma Membrane Na⁺-Coupled Citrate Transporter (SLC13A5) and Neonatal Epileptic Encephalopathy. Molecules 2017; 22:molecules22030378. [PMID: 28264506 PMCID: PMC6155422 DOI: 10.3390/molecules22030378] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 12/30/2022] Open
Abstract
SLC13A5 is a Na+-coupled transporter for citrate that is expressed in the plasma membrane of specific cell types in the liver, testis, and brain. It is an electrogenic transporter with a Na+:citrate3− stoichiometry of 4:1. In humans, the Michaelis constant for SLC13A5 to transport citrate is ~600 μM, which is physiologically relevant given that the normal concentration of citrate in plasma is in the range of 150–200 μM. Li+ stimulates the transport function of human SLC13A5 at concentrations that are in the therapeutic range in patients on lithium therapy. Human SLC13A5 differs from rodent Slc13a5 in two important aspects: the affinity of the human transporter for citrate is ~30-fold less than that of the rodent transporter, thus making human SLC13A5 a low-affinity/high-capacity transporter and the rodent Slc13a5 a high-affinity/low-capacity transporter. In the liver, SLC13A5 is expressed exclusively in the sinusoidal membrane of the hepatocytes, where it plays a role in the uptake of circulating citrate from the sinusoidal blood for metabolic use. In the testis, the transporter is expressed only in spermatozoa, which is also only in the mid piece where mitochondria are located; the likely function of the transporter in spermatozoa is to mediate the uptake of citrate present at high levels in the seminal fluid for subsequent metabolism in the sperm mitochondria to generate biological energy, thereby supporting sperm motility. In the brain, the transporter is expressed mostly in neurons. As astrocytes secrete citrate into extracellular medium, the potential function of SLC13A5 in neurons is to mediate the uptake of circulating citrate and astrocyte-released citrate for subsequent metabolism. Slc13a5-knockout mice have been generated; these mice do not have any overt phenotype but are resistant to experimentally induced metabolic syndrome. Recently however, loss-of-function mutations in human SLC13A5 have been found to cause severe epilepsy and encephalopathy early in life. Interestingly, there is no evidence of epilepsy or encephalopathy in Slc13a5-knockout mice, underlining the significant differences in clinical consequences of the loss of function of this transporter between humans and mice. The markedly different biochemical features of human SLC13A5 and mouse Slc13a5 likely contribute to these differences between humans and mice with regard to the metabolic consequences of the transporter deficiency. The exact molecular mechanisms by which the functional deficiency of the citrate transporter causes epilepsy and impairs neuronal development and function remain to be elucidated, but available literature implicate both dysfunction of GABA (γ-aminobutyrate) signaling and hyperfunction of NMDA (N-methyl-d-aspartate) receptor signaling. Plausible synaptic mechanisms linking loss-of-function mutations in SLC13A5 to epilepsy are discussed.
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97
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Willmes DM, Helfand SL, Birkenfeld AL. The longevity transporter mIndy (Slc13a5) as a target for treating hepatic steatosis and insulin resistance. Aging (Albany NY) 2016; 8:208-9. [PMID: 26928109 PMCID: PMC4789574 DOI: 10.18632/aging.100907] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Diana M Willmes
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Dresden, Germany.,Paul Langerhans Institute Dresden (PLID), German Center for Diabetes Research (DZD), Dresden, Germany
| | - Stephen L Helfand
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Andreas L Birkenfeld
- Section of Metabolic Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Dresden, Germany.,Paul Langerhans Institute Dresden (PLID), German Center for Diabetes Research (DZD), Dresden, Germany
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98
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Lee HW, Handlogten ME, Osis G, Clapp WL, Wakefield DN, Verlander JW, Weiner ID. Expression of sodium-dependent dicarboxylate transporter 1 (NaDC1/SLC13A2) in normal and neoplastic human kidney. Am J Physiol Renal Physiol 2016; 312:F427-F435. [PMID: 27927654 PMCID: PMC5374311 DOI: 10.1152/ajprenal.00559.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/15/2016] [Accepted: 12/05/2016] [Indexed: 12/21/2022] Open
Abstract
Regulated dicarboxylate transport is critical for acid-base homeostasis, prevention of calcium nephrolithiasis, regulation of collecting duct sodium chloride transport, and the regulation of blood pressure. Although luminal dicarboxylate reabsorption via NaDC1 (SLC13A2) is believed to be the primary mechanism regulating renal dicarboxylate transport, the specific localization of NaDC1 in the human kidney is currently unknown. This study's purpose was to determine NaDC1's expression in normal and neoplastic human kidneys. Immunoblot analysis demonstrated NaDC1 expression with an apparent molecular weight of ~61 kDa. Immunohistochemistry showed apical NaDC1 immunolabel in the proximal tubule of normal human kidney tissue; well-preserved proximal tubule brush border was clearly labeled. Apical NaDC1 expression was evident throughout the entire proximal tubule, including the initial proximal convoluted tubule, as identified by origination from the glomerular tuft, and extending through the terminal of the proximal tubule, the proximal straight tubule in the outer medulla. We confirmed proximal tubule localization by colocalization with the proximal tubule specific protein, NBCe1. NaDC1 immunolabel was not detected other than in the proximal tubule. In addition, NaDC1 immunolabel was not detected in tumors of presumed proximal tubule origin, clear cell and papillary renal cell carcinoma, or in tumors of nonproximal tubule origin, oncocytoma and chromophobe carcinoma. In summary, 1) in the human kidney, apical NaDC1 immunolabel is present throughout the entire proximal tubule, and is not detectable in other renal cells; and 2) NaDC1 immunolabel is not present in renal tumors. These studies provide important information regarding NaDC1's role in human dicarboxylate metabolism.
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Affiliation(s)
- Hyun-Wook Lee
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Mary E Handlogten
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Gunars Osis
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - William L Clapp
- Department of Pathology, University of Florida College of Medicine, Gainesville, Florida; and
| | - Dara N Wakefield
- Department of Pathology, University of Florida College of Medicine, Gainesville, Florida; and
| | - Jill W Verlander
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - I David Weiner
- Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida; .,Nephrology and Hypertension Section, Gainesville Veterans Affairs Medical Center, Gainesville, Florida
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99
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With mouse age comes wisdom: A review and suggestions of relevant mouse models for age-related conditions. Mech Ageing Dev 2016; 160:54-68. [DOI: 10.1016/j.mad.2016.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 07/07/2016] [Accepted: 07/15/2016] [Indexed: 12/14/2022]
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100
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Pesta DH, Perry RJ, Guebre-Egziabher F, Zhang D, Jurczak M, Fischer-Rosinsky A, Daniels MA, Willmes DM, Bhanot S, Bornstein SR, Knauf F, Samuel VT, Shulman GI, Birkenfeld AL. Prevention of diet-induced hepatic steatosis and hepatic insulin resistance by second generation antisense oligonucleotides targeted to the longevity gene mIndy (Slc13a5). Aging (Albany NY) 2016; 7:1086-93. [PMID: 26647160 PMCID: PMC4712334 DOI: 10.18632/aging.100854] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Reducing the expression of the Indy (I'm Not Dead Yet) gene in lower organisms extends life span by mechanisms resembling caloric restriction. Similarly, deletion of the mammalian homolog, mIndy (Slc13a5), encoding for a plasma membrane tricarboxylate transporter, protects from aging- and diet-induced adiposity and insulin resistance in mice. The organ specific contribution to this phenotype is unknown. We examined the impact of selective inducible hepatic knockdown of mIndy on whole body lipid and glucose metabolism using 2′-O-methoxyethyl chimeric anti-sense oligonucleotides (ASOs) in high-fat fed rats. 4-week treatment with 2′-O-methoxyethyl chimeric ASO reduced mIndy mRNA expression by 91% (P<0.001) compared to control ASO. Besides similar body weights between both groups, mIndy-ASO treatment lead to a 74% reduction in fasting plasma insulin concentrations as well as a 35% reduction in plasma triglycerides. Moreover, hepatic triglyceride content was significantly reduced by the knockdown of mIndy, likely mediating a trend to decreased basal rates of endogenous glucose production as well as an increased suppression of hepatic glucose production by 25% during a hyperinsulinemic-euglycemic clamp. Together, these data suggest that inducible liver-selective reduction of mIndy in rats is able to ameliorate hepatic steatosis and insulin resistance, conditions occurring with high calorie diets and during aging.
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Affiliation(s)
- Dominik H Pesta
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Department of Sport Science, Medical Section, University of Innsbruck, Innsbruck, Austria.,Department of Visceral, Transplant, and Thoracic Surgery, D. Swarovski Research Laboratory, Medical University of Innsbruck, Innsbruck, Austria.,Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University Düsseldorf, German Center for Diabetes Research, Partner Düsseldorf, Düsseldorf, Germany
| | - Rachel J Perry
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA
| | | | - Dongyan Zhang
- Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Michael Jurczak
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Antje Fischer-Rosinsky
- Charité - University School of Medicine, Department of Endocrinology, Diabetes and Nutrition, Berlin, Germany
| | - Martin A Daniels
- Charité - University School of Medicine, Department of Endocrinology, Diabetes and Nutrition, Berlin, Germany.,Section of Metabolic Vascular Medicine, Medical Clinic III and Paul Langerhans Institute Dresden (PLID), TU Dresden, Germany
| | - Diana M Willmes
- Section of Metabolic Vascular Medicine, Medical Clinic III and Paul Langerhans Institute Dresden (PLID), TU Dresden, Germany.,German Center for Diabetes Research (DZD), Dresden, Germany
| | | | - Stefan R Bornstein
- Section of Metabolic Vascular Medicine, Medical Clinic III and Paul Langerhans Institute Dresden (PLID), TU Dresden, Germany.,German Center for Diabetes Research (DZD), Dresden, Germany.,Section of Diabetes and Nutritional Sciences, Rayne Institute, King's College London, London, UK
| | - Felix Knauf
- University Clinic Erlangen, Erlangen, Germany
| | - Varman T Samuel
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Veterans Affairs Medical Center, West Haven, CT, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA
| | - Andreas L Birkenfeld
- Section of Metabolic Vascular Medicine, Medical Clinic III and Paul Langerhans Institute Dresden (PLID), TU Dresden, Germany.,German Center for Diabetes Research (DZD), Dresden, Germany.,Section of Diabetes and Nutritional Sciences, Rayne Institute, King's College London, London, UK
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