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Rothman DL, Behar KL, Dienel GA. Mechanistic stoichiometric relationship between the rates of neurotransmission and neuronal glucose oxidation: Reevaluation of and alternatives to the pseudo-malate-aspartate shuttle model. J Neurochem 2024; 168:555-591. [PMID: 36089566 DOI: 10.1111/jnc.15619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/08/2022] [Accepted: 04/15/2022] [Indexed: 11/26/2022]
Abstract
The ~1:1 stoichiometry between the rates of neuronal glucose oxidation (CMRglc-ox-N) and glutamate (Glu)/γ-aminobutyric acid (GABA)-glutamine (Gln) neurotransmitter (NT) cycling between neurons and astrocytes (VNTcycle) has been firmly established. However, the mechanistic basis for this relationship is not fully understood, and this knowledge is critical for the interpretation of metabolic and brain imaging studies in normal and diseased brain. The pseudo-malate-aspartate shuttle (pseudo-MAS) model established the requirement for glycolytic metabolism in cultured glutamatergic neurons to produce NADH that is shuttled into mitochondria to support conversion of extracellular Gln (i.e., astrocyte-derived Gln in vivo) into vesicular neurotransmitter Glu. The evaluation of this model revealed that it could explain half of the 1:1 stoichiometry and it has limitations. Modifications of the pseudo-MAS model were, therefore, devised to address major knowledge gaps, that is, submitochondrial glutaminase location, identities of mitochondrial carriers for Gln and other model components, alternative mechanisms to transaminate α-ketoglutarate to form Glu and shuttle glutamine-derived ammonia while maintaining mass balance. All modified models had a similar 0.5 to 1.0 predicted mechanistic stoichiometry between VNTcycle and the rate of glucose oxidation. Based on studies of brain β-hydroxybutyrate oxidation, about half of CMRglc-ox-N may be linked to glutamatergic neurotransmission and localized in pre-synaptic structures that use pseudo-MAS type mechanisms for Glu-Gln cycling. In contrast, neuronal compartments that do not participate in transmitter cycling may use the MAS to sustain glucose oxidation. The evaluation of subcellular compartmentation of neuronal glucose metabolism in vivo is a critically important topic for future studies to understand glutamatergic and GABAergic neurotransmission.
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Affiliation(s)
- Douglas L Rothman
- Magnetic Resonance Research Center and Departments of Radiology and Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Kevin L Behar
- Magnetic Resonance Research Center and Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
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2
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Trejo-Solis C, Silva-Adaya D, Serrano-García N, Magaña-Maldonado R, Jimenez-Farfan D, Ferreira-Guerrero E, Cruz-Salgado A, Castillo-Rodriguez RA. Role of Glycolytic and Glutamine Metabolism Reprogramming on the Proliferation, Invasion, and Apoptosis Resistance through Modulation of Signaling Pathways in Glioblastoma. Int J Mol Sci 2023; 24:17633. [PMID: 38139462 PMCID: PMC10744281 DOI: 10.3390/ijms242417633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023] Open
Abstract
Glioma cells exhibit genetic and metabolic alterations that affect the deregulation of several cellular signal transduction pathways, including those related to glucose metabolism. Moreover, oncogenic signaling pathways induce the expression of metabolic genes, increasing the metabolic enzyme activities and thus the critical biosynthetic pathways to generate nucleotides, amino acids, and fatty acids, which provide energy and metabolic intermediates that are essential to accomplish the biosynthetic needs of glioma cells. In this review, we aim to explore how dysregulated metabolic enzymes and their metabolites from primary metabolism pathways in glioblastoma (GBM) such as glycolysis and glutaminolysis modulate anabolic and catabolic metabolic pathways as well as pro-oncogenic signaling and contribute to the formation, survival, growth, and malignancy of glioma cells. Also, we discuss promising therapeutic strategies by targeting the key players in metabolic regulation. Therefore, the knowledge of metabolic reprogramming is necessary to fully understand the biology of malignant gliomas to improve patient survival significantly.
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Affiliation(s)
- Cristina Trejo-Solis
- Laboratorio Experimental de Enfermedades Neurodegenerativas, Laboratorio de Reprogramación Celular, Departamento de Neurofisiología, Instituto Nacional de Neurología y Neurocirugía, Ciudad de Mexico 14269, Mexico; (D.S.-A.); (N.S.-G.); (R.M.-M.)
| | - Daniela Silva-Adaya
- Laboratorio Experimental de Enfermedades Neurodegenerativas, Laboratorio de Reprogramación Celular, Departamento de Neurofisiología, Instituto Nacional de Neurología y Neurocirugía, Ciudad de Mexico 14269, Mexico; (D.S.-A.); (N.S.-G.); (R.M.-M.)
| | - Norma Serrano-García
- Laboratorio Experimental de Enfermedades Neurodegenerativas, Laboratorio de Reprogramación Celular, Departamento de Neurofisiología, Instituto Nacional de Neurología y Neurocirugía, Ciudad de Mexico 14269, Mexico; (D.S.-A.); (N.S.-G.); (R.M.-M.)
| | - Roxana Magaña-Maldonado
- Laboratorio Experimental de Enfermedades Neurodegenerativas, Laboratorio de Reprogramación Celular, Departamento de Neurofisiología, Instituto Nacional de Neurología y Neurocirugía, Ciudad de Mexico 14269, Mexico; (D.S.-A.); (N.S.-G.); (R.M.-M.)
| | - Dolores Jimenez-Farfan
- Laboratorio de Inmunología, División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad de Mexico 04510, Mexico;
| | - Elizabeth Ferreira-Guerrero
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca 62100, Mexico; (E.F.-G.); (A.C.-S.)
| | - Arturo Cruz-Salgado
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca 62100, Mexico; (E.F.-G.); (A.C.-S.)
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3
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Bailleul J, Vlashi E. Glioblastomas: Hijacking Metabolism to Build a Flexible Shield for Therapy Resistance. Antioxid Redox Signal 2023; 39:957-979. [PMID: 37022791 PMCID: PMC10655009 DOI: 10.1089/ars.2022.0088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 02/01/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023]
Abstract
Significance: Glioblastomas (GBMs) are among the most lethal tumors despite the almost exclusive localization to the brain. This is largely due to therapeutic resistance. Radiation and chemotherapy significantly increase the survival for GBM patients, however, GBMs always recur, and the median overall survival is just over a year. Proposed reasons for such intractable resistance to therapy are numerous and include tumor metabolism, in particular, the ability of tumor cells to reconfigure metabolic fluxes on demand (metabolic plasticity). Understanding how the hard-wired, oncogene-driven metabolic tendencies of GBMs intersect with flexible, context-induced metabolic rewiring promises to reveal novel approaches for combating therapy resistance. Recent Advances: Personalized genome-scale metabolic flux models have recently provided evidence that metabolic flexibility promotes radiation resistance in cancer and identified tumor redox metabolism as a major predictor for resistance to radiation therapy (RT). It was demonstrated that radioresistant tumors, including GBM, reroute metabolic fluxes to boost the levels of reducing factors of the cell, thus enhancing clearance of reactive oxygen species that are generated during RT and promoting survival. Critical Issues: The current body of knowledge from published studies strongly supports the notion that robust metabolic plasticity can act as a (flexible) shield against the cytotoxic effects of standard GBM therapies, thus driving therapy resistance. The limited understanding of the critical drivers of such metabolic plasticity hampers the rational design of effective combination therapies. Future Directions: Identifying and targeting regulators of metabolic plasticity, rather than specific metabolic pathways, in combination with standard-of-care treatments have the potential to improve therapeutic outcomes in GBM. Antioxid. Redox Signal. 39, 957-979.
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Affiliation(s)
- Justine Bailleul
- Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Erina Vlashi
- Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California, USA
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4
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Lee IH, Walker DI, Lin Y, Smith MR, Mandl KD, Jones DP, Kong SW. Association between Neuroligin-1 polymorphism and plasma glutamine levels in individuals with autism spectrum disorder. EBioMedicine 2023; 95:104746. [PMID: 37544204 PMCID: PMC10427990 DOI: 10.1016/j.ebiom.2023.104746] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 08/08/2023] Open
Abstract
BACKGROUND Unravelling the relationships between candidate genes and autism spectrum disorder (ASD) phenotypes remains an outstanding challenge. Endophenotypes, defined as inheritable, measurable quantitative traits, might provide intermediary links between genetic risk factors and multifaceted ASD phenotypes. In this study, we sought to determine whether plasma metabolite levels could serve as endophenotypes in individuals with ASD and their family members. METHODS We employed an untargeted, high-resolution metabolomics platform to analyse 14,342 features across 1099 plasma samples. These samples were collected from probands and their family members participating in the Autism Genetic Resource Exchange (AGRE) (N = 658), compared with neurotypical individuals enrolled in the PrecisionLink Health Discovery (PLHD) program at Boston Children's Hospital (N = 441). We conducted a metabolite quantitative trait loci (mQTL) analysis using whole-genome genotyping data from each cohort in AGRE and PLHD, aiming to prioritize significant mQTL and metabolite pairs that were exclusively observed in AGRE. FINDINGS Within the AGRE group, we identified 54 significant associations between genotypes and metabolite levels (P < 5.27 × 10-11), 44 of which were not observed in the PLHD group. Plasma glutamine levels were found to be associated with variants in the NLGN1 gene, a gene that encodes post-synaptic cell-adhesion molecules in excitatory neurons. This association was not detected in the PLHD group. Notably, a significant negative correlation between plasma glutamine and glutamate levels was observed in the AGRE group, but not in the PLHD group. Furthermore, plasma glutamine levels showed a negative correlation with the severity of restrictive and repetitive behaviours (RRB) in ASD, although no direct association was observed between RRB severity and the NLGN1 genotype. INTERPRETATION Our findings suggest that plasma glutamine levels could potentially serve as an endophenotype, thus establishing a link between the genetic risk associated with NLGN1 and the severity of RRB in ASD. This identified association could facilitate the development of novel therapeutic targets, assist in selecting specific cohorts for clinical trials, and provide insights into target symptoms for future ASD treatment strategies. FUNDING This work was supported by the National Institute of Health (grant numbers: R01MH107205, U01TR002623, R24OD024622, OT2OD032720, and R01NS129188) and the PrecisionLink Biobank for Health Discovery at Boston Children's Hospital.
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Affiliation(s)
- In-Hee Lee
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02215, USA
| | - Douglas I Walker
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Yufei Lin
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02215, USA
| | - Matthew Ryan Smith
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, 30602, USA; Atlanta Department of Veterans Affairs Medical Center, Decatur, GA, 30033, USA
| | - Kenneth D Mandl
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02215, USA; Department of Biomedical Informatics, Harvard Medical School, Boston, MA, 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Dean P Jones
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, 30602, USA
| | - Sek Won Kong
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02215, USA; Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
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5
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Bhat UA, Kumar SA, Chakravarty S, Patel AB, Kumar A. Differential Effects of Chronic Ethanol Use on Mouse Neuronal and Astroglial Metabolic Activity. Neurochem Res 2023:10.1007/s11064-023-03922-y. [PMID: 37069415 DOI: 10.1007/s11064-023-03922-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/19/2023]
Abstract
Chronic alcohol use disorder, a major risk factor for the development of neuropsychiatric disorders including addiction to other substances, is associated with several neuropathology including perturbed neuronal and glial activities in the brain. It affects carbon metabolism in specific brain regions, and perturbs neuro-metabolite homeostasis in neuronal and glial cells. Alcohol induced changes in the brain neurochemical profile accompany the negative emotional state associated with dysregulated reward and sensitized stress response to withdrawal. However, the underlying alterations in neuro-astroglial activities and neurochemical dysregulations in brain regions after chronic alcohol use are poorly understood. This study evaluates the impact of chronic ethanol use on the regional neuro-astroglial metabolic activity using 1H-[13C]-NMR spectroscopy in conjunction with infusion of [1,6-13C2]glucose and sodium [2-13C]acetate, respectively, after 48 h of abstinence. Besides establishing detailed 13C labeling of neuro-metabolites in a brain region-specific manner, our results show chronic ethanol induced-cognitive deficits along with a reduction in total glucose oxidation rates in the hippocampus and striatum. Furthermore, using [2-13C]acetate infusion, we showed an alcohol-induced increase in astroglial metabolic activity in the hippocampus and prefrontal cortex. Interestingly, increased astroglia activity in the hippocampus and prefrontal cortex was associated with a differential expression of monocarboxylic acid transporters that are regulating acetate uptake and metabolism in the brain.
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Affiliation(s)
- Unis Ahmad Bhat
- Epigenetics and Neuropsychiatric Disorders Laboratory, CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Habsiguda, Hyderabad, Telangana State (TS), 500007, India
| | - Sreemantula Arun Kumar
- Applied Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, India
| | - Sumana Chakravarty
- Applied Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Anant Bahadur Patel
- Epigenetics and Neuropsychiatric Disorders Laboratory, CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Habsiguda, Hyderabad, Telangana State (TS), 500007, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Habsiguda, Hyderabad, Telangana State (TS), 500007, India.
| | - Arvind Kumar
- Epigenetics and Neuropsychiatric Disorders Laboratory, CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Habsiguda, Hyderabad, Telangana State (TS), 500007, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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6
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Guerrero-Molina MP, Morales-Conejo M, Delmiro A, Morán M, Domínguez-González C, Arranz-Canales E, Ramos-González A, Arenas J, Martín MA, de la Aleja JG. High-dose oral glutamine supplementation reduces elevated glutamate levels in cerebrospinal fluid in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome. Eur J Neurol 2023; 30:538-547. [PMID: 36334048 DOI: 10.1111/ene.15626] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 10/07/2022] [Accepted: 10/27/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND PURPOSE Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous disorder caused by mitochondrial DNA mutations. There are no disease-modifying therapies, and treatment remains mainly supportive. It has been shown previously that patients with MELAS syndrome have significantly increased cerebrospinal fluid (CSF) glutamate and significantly decreased CSF glutamine levels compared to controls. Glutamine has many metabolic fates in neurons and astrocytes, and the glutamate-glutamine cycle couples with many metabolic pathways depending on cellular requirements. The aim was to compare CSF glutamate and glutamine levels before and after dietary glutamine supplementation. It is postulated that high-dose oral glutamine supplementation could reduce the increase in glutamate levels. METHOD This open-label, single-cohort study determined the safety and changes in glutamate and glutamine levels in CSF after 12 weeks of oral glutamine supplementation. RESULTS Nine adult patients with MELAS syndrome (66.7% females, mean age 35.8 ± 3.2 years) were included. After glutamine supplementation, CSF glutamate levels were significantly reduced (9.77 ± 1.21 vs. 18.48 ± 1.34 μmol/l, p < 0.001) and CSF glutamine levels were significantly increased (433.66 ± 15.31 vs. 336.31 ± 12.92 μmol/l, p = 0.002). A side effect observed in four of nine patients was a mild sensation of satiety. One patient developed mild and transient elevation of transaminases, and another patient was admitted for an epileptic status without stroke-like episode. DISCUSSION This study demonstrates that high-dose oral glutamine supplementation significantly reduces CSF glutamate and increases CSF glutamine levels in patients with MELAS syndrome. These findings may have potential therapeutic implications in these patients. TRIAL REGISTRATION INFORMATION ClinicalTrials.gov Identifier: NCT04948138. Initial release 24 June 2021, first patient enrolled 1 July 2021. https://clinicaltrials.gov/ct2/show/NCT04948138.
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Affiliation(s)
| | - Montserrat Morales-Conejo
- Department of Internal Medicine, University Hospital, Madrid, Spain
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
| | - Aitor Delmiro
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - María Morán
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Cristina Domínguez-González
- Neurology Department, Neuromuscular Disorders Unit, University Hospital, Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Elena Arranz-Canales
- Department of Internal Medicine, University Hospital, Madrid, Spain
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
| | | | - Joaquín Arenas
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Miguel A Martín
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Jesús González de la Aleja
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
- Neurology Department, Epilepsy Unit, University Hospital, Madrid, Spain
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7
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Guerrero-Molina MP, Morales-Conejo M, Delmiro A, Morán M, Domínguez-González C, Arranz-Canales E, Ramos-González A, Arenas J, Martín MA, González de la Aleja J. Elevated glutamate and decreased glutamine levels in the cerebrospinal fluid of patients with MELAS syndrome. J Neurol 2022; 269:3238-3248. [PMID: 35088140 PMCID: PMC8794606 DOI: 10.1007/s00415-021-10942-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/22/2022]
Abstract
Background Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous disorder caused by mitochondrial DNA (mtDNA) mutations in the MT-TL1 gene. The pathophysiology of neurological manifestations is still unclear, but neuronal hyperexcitability and neuron–astrocyte uncoupling have been suggested. Glutamatergic neurotransmission is linked to glucose oxidation and mitochondrial metabolism in astrocytes and neurons. Given the relevance of neuron–astrocyte metabolic coupling and astrocyte function regulating energetic metabolism, we aimed to assess glutamate and glutamine CSF levels in MELAS patients. Methods This prospective observational case–control study determined glutamate and glutamine CSF levels in patients with MELAS syndrome and compared them with controls. The plasma and CSF levels of the remaining amino acids and lactate were also determined. Results Nine adult patients with MELAS syndrome (66.7% females mean age 35.8 ± 3.2 years) and 19 controls (63.2% females mean age 42.7 ± 3.8 years) were included. The CSF glutamate levels were significantly higher in patients with MELAS than in controls (18.48 ± 1.34 vs. 5.31 ± 1.09 μmol/L, p < 0.001). Significantly lower glutamine concentrations in patients with MELAS than controls were shown in CSF (336.31 ± 12.92 vs. 407.06 ± 15.74 μmol/L, p = 0.017). Moreover, the CSF levels of alanine, the branched-chain amino acids (BCAAs) and lactate were significantly higher in patients with MELAS. Conclusions Our results suggest the glutamate–glutamine cycle is altered probably due to metabolic imbalance, and as a result, the lactate–alanine and BCAA–glutamate cycles are upregulated. These findings might have therapeutic implications in MELAS syndrome. Supplementary Information The online version contains supplementary material available at 10.1007/s00415-021-10942-7.
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Affiliation(s)
- María Paz Guerrero-Molina
- Neuromuscular Disorders Unit, Neurology Department, University Hospital, 12 de Octubre, Madrid, Spain.
| | - Montserrat Morales-Conejo
- Department of Internal Medicine, University Hospital, 12 de Octubre, Madrid, Spain.,National Reference Center for Congenital Errors of Metabolism (CSUR) an European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, 12 de Octubre, Madrid, Spain.,Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain
| | - Aitor Delmiro
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain.,Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain.,Research Institute ('imas12'), University Hospital, 12 de Octubre, Madrid, Spain
| | - María Morán
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain.,Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain.,Research Institute ('imas12'), University Hospital, 12 de Octubre, Madrid, Spain
| | - Cristina Domínguez-González
- Neuromuscular Disorders Unit, Neurology Department, University Hospital, 12 de Octubre, Madrid, Spain.,Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain.,Research Institute ('imas12'), University Hospital, 12 de Octubre, Madrid, Spain
| | - Elena Arranz-Canales
- Department of Internal Medicine, University Hospital, 12 de Octubre, Madrid, Spain.,National Reference Center for Congenital Errors of Metabolism (CSUR) an European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, 12 de Octubre, Madrid, Spain
| | - Ana Ramos-González
- Department of Neuroradiology, University Hospital, 12 de Octubre, Madrid, Spain
| | - Joaquín Arenas
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain.,Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain.,Research Institute ('imas12'), University Hospital, 12 de Octubre, Madrid, Spain
| | - Miguel A Martín
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, Madrid, Spain.,Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain.,Research Institute ('imas12'), University Hospital, 12 de Octubre, Madrid, Spain
| | - Jesús González de la Aleja
- National Reference Center for Congenital Errors of Metabolism (CSUR) an European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, 12 de Octubre, Madrid, Spain.,Epilepsy Unit, Neurology Department, University Hospital, 12 de Octubre, Madrid, Spain
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8
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Dhaher R, Chen EC, Perez E, Rapuano A, Sandhu MRS, Gruenbaum SE, Deshpande K, Dai F, Zaveri HP, Eid T. Oral glutamine supplementation increases seizure severity in a rodent model of mesial temporal lobe epilepsy. Nutr Neurosci 2022; 25:64-69. [PMID: 31900092 PMCID: PMC8970572 DOI: 10.1080/1028415x.2019.1708568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background: Glutamine synthetase (GS) is the only enzyme known to synthesize significant amounts of glutamine in mammals, and loss of GS in the hippocampus has been implicated in the pathophysiology of medication refractory mesial temporal lobe epilepsy (MTLE). Moreover, loss-of-function mutations of the GS gene causes severe epileptic encephalopathy, and supplementation with glutamine has been shown to normalize EEG and possibly improve the outcome in these patients. Here we examined whether oral glutamine supplementation is an effective treatment for MTLE by assessing the frequency and severity of seizures after supplementation in a translationally relevant model of the disease.Methods: Male Sprague Dawley rats (380-400 g) were allowed to drink unlimited amounts of glutamine in water (3.6% w/v; n = 8) or pure water (n = 8) for several weeks. Ten days after the start of glutamine supplementation, GS was chronically inhibited in the hippocampus to induce MTLE. Continuous video-intracranial EEG was collected for 21 days to determine the frequency and severity of seizures.Results: While there was no change in seizure frequency between the groups, the proportion of convulsive seizures was significantly higher in glutamine treated animals during the first three days of GS inhibition.Conclusion: The results suggest that oral glutamine supplementation transiently increases seizure severity in the initial stages of an epilepsy model, indicating a potential role of the amino acid in seizure propagation and epileptogenesis.
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Affiliation(s)
- Roni Dhaher
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06520, USA,Correspondence Roni Dhaher, PhD, Associate Research Scientist in Neurosurgery, Yale School of Medicine, 330 Cedar St., P.O. Box 208035, New Haven, CT 06520-8035, USA, Fax: +1-203-688-8597,
| | - Eric C. Chen
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Edgar Perez
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Amedeo Rapuano
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06520, USA
| | | | - Shaun E. Gruenbaum
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Ketaki Deshpande
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Feng Dai
- Department of Biostatistics, Yale School of Medicine, New Haven, CT 06520, USA
| | - Hitten P. Zaveri
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06520, USA
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9
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Edwards DN, Ngwa VM, Raybuck AL, Wang S, Hwang Y, Kim LC, Cho SH, Paik Y, Wang Q, Zhang S, Manning HC, Rathmell JC, Cook RS, Boothby MR, Chen J. Selective glutamine metabolism inhibition in tumor cells improves antitumor T lymphocyte activity in triple-negative breast cancer. J Clin Invest 2021; 131:140100. [PMID: 33320840 PMCID: PMC7880417 DOI: 10.1172/jci140100] [Citation(s) in RCA: 158] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 12/10/2020] [Indexed: 12/27/2022] Open
Abstract
Rapidly proliferating tumor and immune cells need metabolic programs that support energy and biomass production. The amino acid glutamine is consumed by effector T cells and glutamine-addicted triple-negative breast cancer (TNBC) cells, suggesting that a metabolic competition for glutamine may exist within the tumor microenvironment, potentially serving as a therapeutic intervention strategy. Here, we report that there is an inverse correlation between glutamine metabolic genes and markers of T cell-mediated cytotoxicity in human basal-like breast cancer (BLBC) patient data sets, with increased glutamine metabolism and decreased T cell cytotoxicity associated with poor survival. We found that tumor cell-specific loss of glutaminase (GLS), a key enzyme for glutamine metabolism, improved antitumor T cell activation in both a spontaneous mouse TNBC model and orthotopic grafts. The glutamine transporter inhibitor V-9302 selectively blocked glutamine uptake by TNBC cells but not CD8+ T cells, driving synthesis of glutathione, a major cellular antioxidant, to improve CD8+ T cell effector function. We propose a "glutamine steal" scenario, in which cancer cells deprive tumor-infiltrating lymphocytes of needed glutamine, thus impairing antitumor immune responses. Therefore, tumor-selective targeting of glutamine metabolism may be a promising therapeutic strategy in TNBC.
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Affiliation(s)
- Deanna N. Edwards
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Verra M. Ngwa
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Ariel L. Raybuck
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Shan Wang
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yoonha Hwang
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Laura C. Kim
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Sung Hoon Cho
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yeeun Paik
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Qingfei Wang
- Department of Biological Sciences, College of Science, University of Notre Dame, Notre Dame, Indiana, USA
- Mike and Josie Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana, USA
| | - Siyuan Zhang
- Department of Biological Sciences, College of Science, University of Notre Dame, Notre Dame, Indiana, USA
- Mike and Josie Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana, USA
| | - H. Charles Manning
- Department of Chemistry
- Center for Molecular Probes
- Vanderbilt Institute for Imaging Sciences
- Department of Radiology and Radiological Sciences
- Vanderbilt-Ingram Cancer Center
| | - Jeffrey C. Rathmell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt-Ingram Cancer Center
- Vanderbilt Institute for Infection, Immunology and Inflammation, and
| | - Rebecca S. Cook
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt-Ingram Cancer Center
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark R. Boothby
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, and
| | - Jin Chen
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt-Ingram Cancer Center
- Vanderbilt Institute for Infection, Immunology and Inflammation, and
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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10
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He W, Wu G. Metabolism of Amino Acids in the Brain and Their Roles in Regulating Food Intake. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1265:167-185. [PMID: 32761576 DOI: 10.1007/978-3-030-45328-2_10] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amino acids (AAs) and their metabolites play an important role in neurological health and function. They are not only the building blocks of protein but are also neurotransmitters. In the brain, glutamate and aspartate are the major excitatory neurotransmitters, whereas γ-aminobutyrate (GABA, a metabolite of glutamate) and glycine are the major inhibitory neurotransmitters. Nitric oxide (NO, a metabolite of arginine), H2S (a metabolite of cysteine), serotonin (a metabolite of tryptophan) and histamine (a metabolite of histidine), as well as dopamine and norepinephrine (metabolites of tyrosine) are neurotransmitters to modulate synaptic plasticity, neuronal activity, learning, motor control, motivational behavior, emotion, and executive function. Concentrations of glutamine (a precursor of glutamate and aspartate), branched-chain AAs (precursors of glutamate, glutamine and aspartate), L-serine (a precursor of glycine and D-serine), methionine and phenylalanine in plasma are capable of affecting neurotransmission through the syntheses of glutamate, aspartate, and glycine, as well as the competitive transport of tryptophan and tyrosine across from the blood-brain barrier. Adequate consumption of AAs is crucial to maintain their concentrations and the production of neurotransmitters in the central nervous system. Thus, the content and balance of AAs in diets have a profound impact on food intake by animals. Knowledge of AA transport and metabolism in the brain is beneficial for improving the health and well-being of humans and animals.
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Affiliation(s)
- Wenliang He
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX, USA.
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11
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Rothman DL, de Graaf RA, Hyder F, Mason GF, Behar KL, De Feyter HM. In vivo 13 C and 1 H-[ 13 C] MRS studies of neuroenergetics and neurotransmitter cycling, applications to neurological and psychiatric disease and brain cancer. NMR IN BIOMEDICINE 2019; 32:e4172. [PMID: 31478594 DOI: 10.1002/nbm.4172] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/30/2019] [Accepted: 05/07/2019] [Indexed: 06/10/2023]
Abstract
In the last 25 years 13 C MRS has been established as the only noninvasive method for measuring glutamate neurotransmission and cell specific neuroenergetics. Although technically and experimentally challenging 13 C MRS has already provided important new information on the relationship between neuroenergetics and neuronal function, the high energy cost of brain function in the resting state and the role of altered neuroenergetics and neurotransmitter cycling in disease. In this paper we review the metabolic and neurotransmitter pathways that can be measured by 13 C MRS and key findings on the linkage between neuroenergetics, neurotransmitter cycling, and brain function. Applications of 13 C MRS to neurological and psychiatric disease as well as brain cancer are reviewed. Recent technological developments that may help to overcome spatial resolution and brain coverage limitations of 13 C MRS are discussed.
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Affiliation(s)
- Douglas L Rothman
- Departments of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
- Departments of Radiology and Biomedical Imaging, and Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, 300 Cedar Street, P.O. Box 208043, New Haven, CT, USA
| | - Robin A de Graaf
- Departments of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Fahmeed Hyder
- Departments of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Graeme F Mason
- Departments of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kevin L Behar
- Department of Psychiatry, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Henk M De Feyter
- Departments of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
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12
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Zhou W, Wahl DR. Metabolic Abnormalities in Glioblastoma and Metabolic Strategies to Overcome Treatment Resistance. Cancers (Basel) 2019; 11:cancers11091231. [PMID: 31450721 PMCID: PMC6770393 DOI: 10.3390/cancers11091231] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/07/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma (GBM) is the most common and aggressive primary brain tumor and is nearly universally fatal. Targeted therapy and immunotherapy have had limited success in GBM, leaving surgery, alkylating chemotherapy and ionizing radiation as the standards of care. Like most cancers, GBMs rewire metabolism to fuel survival, proliferation, and invasion. Emerging evidence suggests that this metabolic reprogramming also mediates resistance to the standard-of-care therapies used to treat GBM. In this review, we discuss the noteworthy metabolic features of GBM, the key pathways that reshape tumor metabolism, and how inhibiting abnormal metabolism may be able to overcome the inherent resistance of GBM to radiation and chemotherapy.
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Affiliation(s)
- Weihua Zhou
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Daniel R Wahl
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA.
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13
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Association between Brain and Plasma Glutamine Levels in Healthy Young Subjects Investigated by MRS and LC/MS. Nutrients 2019; 11:nu11071649. [PMID: 31330962 PMCID: PMC6682979 DOI: 10.3390/nu11071649] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 07/09/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022] Open
Abstract
Both glutamine (Gln) and glutamate (Glu) are known to exist in plasma and brain. However, despite the assumed relationship between brain and plasma, no studies have clarified the association between them. Proton magnetic resonance spectroscopy (MRS) was sequentially performed twice, with a 60-min interval, on 10 males and 10 females using a 3T scanner. Blood samples for liquid chromatography-mass spectrometry (LC/MS) to measure Gln and Glu concentrations in plasma were collected during the time interval between the two MRS sessions. MRS voxels of interest were localized at the posterior cingulate cortex (PCC) and cerebellum (Cbll) and measured by the SPECIAL sequence. Spearman's correlation coefficient was used to examine the association between brain and plasma metabolites. The Gln concentrations in PCC (mean of two measurements) were positively correlated with Gln concentrations in plasma (p < 0.01, r = 0.72). However, the Glu concentrations in the two regions were not correlated with those in plasma. Consideration of the different dynamics of Gln and Glu between plasma and brain is crucial when addressing the pathomechanism and therapeutic strategies for brain disorders such as Alzheimer's disease and hepatic encephalopathy.
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14
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Exchange-mode glutamine transport across CNS cell membranes. Neuropharmacology 2019; 161:107560. [PMID: 30853601 DOI: 10.1016/j.neuropharm.2019.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 12/18/2022]
Abstract
CNS cell membranes possess four transporters capable of exchanging Lglutamine (Gln) for other amino acids: the large neutral amino acid (LNAA) transporters LAT1 and LAT2, the hybrid basic amino acid (L-arginine (Arg), L-leucine (Leu)/LNAA transporter y+LAT2, and the L-alanine/L-serine/L-cysteine transporter 2 (ASCT2). LAT1/LAT2 and y+LAT2 are present in astrocytes, neurons and the blood brain barrier (BBB) - forming cerebral vascular endothelial cells (CVEC), while the location of ASCT2 in the individual cell types is a matter of debate. In the healthy brain, contribution of the exchangers to Gln shuttling from astrocytes to neurons and thus their role in controlling the conversion of Gln to the amino acid neurotransmitters l-glutamate (Glu) and γ-aminobutyric acid (GABA) and Gln flux across the BBB appears negligible as compared to the system A and system N uniporters. Insofar, except for the contribution of LAT1 to the maintenance of Gln homeostasis in the interstitial fluid (ISF), no well-defined CNS-specific function has been established for either of the three transporters in the healthy brain. The Gln-accepting amino acid exchangers appear to gain significance under conditions of excessive brain Gln load (glutaminosis). Excess Gln efflux across the BBB enhances influx into the brain of L-tryptophan (Trp). Excess of Trp is responsible for overloading the brain with neuroactive compounds: serotonin, kynurenic acid, quinolinic acid and/or oxindole, which contribute to neurotransmission imbalance accompanying hyperammonemia. In turn, alterations of y+LAT2-mediated Gln/Arg exchange and Arg uptake in astrocyte, modulate astrocytic nitric oxide synthesis and oxidative/nitrosative stress in ammonia-overexposed brain. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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15
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McDonald T, Puchowicz M, Borges K. Impairments in Oxidative Glucose Metabolism in Epilepsy and Metabolic Treatments Thereof. Front Cell Neurosci 2018; 12:274. [PMID: 30233320 PMCID: PMC6127311 DOI: 10.3389/fncel.2018.00274] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022] Open
Abstract
There is mounting evidence that oxidative glucose metabolism is impaired in epilepsy and recent work has further characterized the metabolic mechanisms involved. In healthy people eating a traditional diet, including carbohydrates, fats and protein, the major energy substrate in brain is glucose. Cytosolic glucose metabolism generates small amounts of energy, but oxidative glucose metabolism in the mitochondria generates most ATP, in addition to biosynthetic precursors in cells. Energy is crucial for the brain to signal "normally," while loss of energy can contribute to seizure generation by destabilizing membrane potentials and signaling in the chronic epileptic brain. Here we summarize the known biochemical mechanisms that contribute to the disturbance in oxidative glucose metabolism in epilepsy, including decreases in glucose transport, reduced activity of particular steps in the oxidative metabolism of glucose such as pyruvate dehydrogenase activity, and increased anaplerotic need. This knowledge justifies the use of alternative brain fuels as sources of energy, such as ketones, TCA cycle intermediates and precursors as well as even medium chain fatty acids and triheptanoin.
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Affiliation(s)
- Tanya McDonald
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
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16
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Xu X, Xu J, Chan KWY, Liu J, Liu H, Li Y, Chen L, Liu G, van Zijl PCM. GlucoCEST imaging with on-resonance variable delay multiple pulse (onVDMP) MRI. Magn Reson Med 2018; 81:47-56. [PMID: 30058240 DOI: 10.1002/mrm.27364] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/21/2018] [Accepted: 04/24/2018] [Indexed: 12/16/2022]
Abstract
PURPOSE To examine the detection sensitivity for the rapidly exchanging hydroxyl protons of D-glucose using the recently developed on-resonance variable delay multi-pulse (onVDMP) chemical exchange saturation transfer (CEST) technique. METHODS The onVDMP method was applied for the detection of water signal changes upon venous D-glucose infusion in mice with 9L glioma xenografts. The effect size of onVDMP MRI during infusion was compared with that of conventional continuous wave (CW) CEST MRI. RESULTS Both methods highlighted the tumor and the blood vessels on D-glucose infusion. In interleaved studies, the mean signal changes detected by onVDMP were found to be 1.8 times higher than those by CW-CEST, attributed to its high labeling efficiency for fast exchanging protons and the labeling of the OH protons over a larger frequency range. CONCLUSIONS The onVDMP method is a more sensitive technique for the detection of exogenous CEST agents with fast-exchanging protons compared to CW-CEST MRI.
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Affiliation(s)
- Xiang Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Jiadi Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Kannie W Y Chan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland.,Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Jing Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Radiology Department, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Huanling Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Ultrasound, Guangzhou Panyu Central Hospital, Guangzhou, China
| | - Yuguo Li
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Lin Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland.,Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China
| | - Guanshu Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Peter C M van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
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17
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Lu M, Zhu XH, Zhang Y, Mateescu G, Chen W. Quantitative assessment of brain glucose metabolic rates using in vivo deuterium magnetic resonance spectroscopy. J Cereb Blood Flow Metab 2017; 37:3518-3530. [PMID: 28503999 PMCID: PMC5669347 DOI: 10.1177/0271678x17706444] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Quantitative assessment of cerebral glucose consumption rate (CMRglc) and tricarboxylic acid cycle flux (VTCA) is crucial for understanding neuroenergetics under physiopathological conditions. In this study, we report a novel in vivo Deuterium (2H) MRS (DMRS) approach for simultaneously measuring and quantifying CMRglc and VTCA in rat brains at 16.4 Tesla. Following a brief infusion of deuterated glucose, dynamic changes of isotope-labeled glucose, glutamate/glutamine (Glx) and water contents in the brain can be robustly monitored from their well-resolved 2H resonances. Dynamic DMRS glucose and Glx data were employed to determine CMRglc and VTCA concurrently. To test the sensitivity of this method in response to altered glucose metabolism, two brain conditions with different anesthetics were investigated. Increased CMRglc (0.46 vs. 0.28 µmol/g/min) and VTCA (0.96 vs. 0.6 µmol/g/min) were found in rats under morphine as compared to deeper anesthesia using 2% isoflurane. This study demonstrates the feasibility and new utility of the in vivo DMRS approach to assess cerebral glucose metabolic rates at high/ultrahigh field. It provides an alternative MRS tool for in vivo study of metabolic coupling relationship between aerobic and anaerobic glucose metabolisms in brain under physiopathological states.
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Affiliation(s)
- Ming Lu
- 1 Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, MN, USA
| | - Xiao-Hong Zhu
- 1 Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, MN, USA
| | - Yi Zhang
- 1 Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, MN, USA
| | - Gheorghe Mateescu
- 2 Case Center for Imaging Research, Departments of Chemistry, Case Western Reserve University, Cleveland, OH, USA
| | - Wei Chen
- 1 Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, MN, USA
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18
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Jeitner TM, Kristoferson E, Azcona JA, Pinto JT, Stalnecker C, Erickson JW, Kung HF, Li J, Ploessl K, Cooper AJL. Fluorination at the 4 position alters the substrate behavior of L-glutamine and L-glutamate: Implications for positron emission tomography of neoplasias. J Fluor Chem 2017; 192:58-67. [PMID: 28546645 DOI: 10.1016/j.jfluchem.2016.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Two 4-fluoro-L-glutamine diastereoisomers [(2S,4R)-4-FGln, (2S,4S)-4-FGln] were previously developed for positron emission tomography. Label uptake into two tumor cell types was greater with [18F](2S,4R)-4-FGln than with [18F](2S,4S)-4-FGln. In the present work we investigated the enzymology of two diastereoisomers of 4-FGln, two diastereoisomers of 4-fluoroglutamate (4-FGlu) (potential metabolites of the 4-FGln diastereoisomers) and another fluoro-derivative of L-glutamine [(2S,4S)-4-(3-fluoropropyl)glutamine (FP-Gln)]. The two 4-FGlu diastereoisomers were found to be moderate-to-good substrates relative to L-glutamate of glutamate dehydrogenase, aspartate aminotransferase and alanine aminotransferase. Additionally, alanine aminotransferase was shown to catalyze an unusual γ-elimination reaction with both 4-FGlu diastereoisomers. Both 4-FGlu diastereoisomers were shown to be poor substrates, but strong inhibitors of glutamine synthetase. Both 4-FGln diastereoisomers were shown to be poor substrates compared to L-glutamine of glutamine transaminase L and α-aminoadipate aminotransferase. However, (2S,4R)-4-FGln was found to be a poor substrate of glutamine transaminase K, whereas (2S,4S)-4-FGln was shown to be an excellent substrate. By contrast, FP-Gln was found to be a poor substrate of all enzymes examined. Evidently, substitution of H in position 4 by F in L-glutamine/L-glutamate has moderate-to-profound effects on enzyme-catalyzed reactions. The present results: 1) show that 4-FGln and 4-FGlu diastereoisomers may be useful for studying active site topology of glutamate- and glutamine-utilizing enzymes; 2) provide a framework for understanding possible metabolic transformations in tumors of 18F-labeled (2S,4R)-4-FGln, (2S,4S)-4-FGln, (2S,4R)-4-FGlu or (2S,4S)-4-FGlu; and 3) show that [18F]FP-Gln is likely to be much less metabolically active in vivo than are the [18F]4-FGln diastereoisomers.
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Affiliation(s)
- Thomas M Jeitner
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Eva Kristoferson
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Juan A Azcona
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - John T Pinto
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Clint Stalnecker
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jon W Erickson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Hank F Kung
- Department of Radiology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Karl Ploessl
- Department of Radiology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
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19
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Li N, Li S, Shen J. Reconstruction of randomly under-sampled spectra for in vivo 13C magnetic resonance spectroscopy. Magn Reson Imaging 2016; 37:216-221. [PMID: 27939434 DOI: 10.1016/j.mri.2016.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 11/26/2022]
Abstract
PURPOSE Over the past decade, many techniques have been developed to reduce radiofrequency (RF) power deposition associated with proton decoupling in in vivo Carbon-13 (13C) magnetic resonance spectroscopy (MRS). In this work we propose a new strategy that uses data under-sampling to achieve reduction in RF power deposition. MATERIALS AND METHODS Essentially, proton decoupling is required only during randomly selected segments of data acquisition. By taking advantage of the sparse spectral pattern of the carboxylic/amide region of in vivo13C spectra of brain, we developed an iterative algorithm to reconstruct spectra from randomly under-sampled data. Fully sampled data were used as references. Reconstructed spectra were compared with the fully sampled references and evaluated using residuals and relative signal intensity errors. RESULTS Numerical simulations and in vivo experiments at 7Tesla demonstrated that this novel decoupling and data processing strategy can effectively reduce decoupling power deposition by greater than 30%. CONCLUSION This study proposes and evaluates a novel approach to acquire 13C data with reduced proton decoupling power deposition and reconstruct in vivo13C spectra of carboxylic/amide metabolite signals using randomly under-sampled data. Because proton decoupling is not needed over a significant portion of data acquisition, this novel approach can effectively reduce the required decoupling power and thus SAR. It opens the possibility of performing in vivo13C experiments of human brain at very high magnetic fields.
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Affiliation(s)
- Ningzhi Li
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Shizhe Li
- Magnetic Resonance Spectroscopy Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Jun Shen
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; Magnetic Resonance Spectroscopy Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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20
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Dolgodilina E, Imobersteg S, Laczko E, Welt T, Verrey F, Makrides V. Brain interstitial fluid glutamine homeostasis is controlled by blood-brain barrier SLC7A5/LAT1 amino acid transporter. J Cereb Blood Flow Metab 2016; 36:1929-1941. [PMID: 26661195 PMCID: PMC5094305 DOI: 10.1177/0271678x15609331] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/20/2015] [Accepted: 08/31/2015] [Indexed: 01/26/2023]
Abstract
L-glutamine (Gln) is the most abundant amino acid in plasma and cerebrospinal fluid and a precursor for the main central nervous system excitatory (L-glutamate) and inhibitory (γ-aminobutyric acid (GABA)) neurotransmitters. Concentrations of Gln and 13 other brain interstitial fluid amino acids were measured in awake, freely moving mice by hippocampal microdialysis using an extrapolation to zero flow rate method. Interstitial fluid levels for all amino acids including Gln were ∼5-10 times lower than in cerebrospinal fluid. Although the large increase in plasma Gln by intraperitoneal (IP) injection of 15N2-labeled Gln (hGln) did not increase total interstitial fluid Gln, low levels of hGln were detected in microdialysis samples. Competitive inhibition of system A (SLC38A1&2; SNAT1&2) or system L (SLC7A5&8; LAT1&2) transporters in brain by perfusion with α-(methylamino)-isobutyric acid (MeAIB) or 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) respectively, was tested. The data showed a significantly greater increase in interstitial fluid Gln upon BCH than MeAIB treatment. Furthermore, brain BCH perfusion also strongly increased the influx of hGln into interstitial fluid following IP injection consistent with transstimulation of LAT1-mediated transendothelial transport. Taken together, the data support the independent homeostatic regulation of amino acids in interstitial fluid vs. cerebrospinal fluid and the role of the blood-brain barrier expressed SLC7A5/LAT1 as a key interstitial fluid gatekeeper.
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Affiliation(s)
- Elena Dolgodilina
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney. CH, University of Zurich, Zurich, Switzerland
| | - Stefan Imobersteg
- Division of Psychiatry Research, University of Zurich, Schlieren, Switzerland
| | - Endre Laczko
- Functional Genomic Center Zurich (FGCZ), ETH and University of Zurich, Zurich, Switzerland
| | - Tobias Welt
- Division of Psychiatry Research, University of Zurich, Schlieren, Switzerland
| | - Francois Verrey
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney. CH, University of Zurich, Zurich, Switzerland
| | - Victoria Makrides
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney. CH, University of Zurich, Zurich, Switzerland
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21
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Zhuo M, Gorgun MF, Englander EW. Augmentation of glycolytic metabolism by meclizine is indispensable for protection of dorsal root ganglion neurons from hypoxia-induced mitochondrial compromise. Free Radic Biol Med 2016; 99:20-31. [PMID: 27458119 PMCID: PMC5538108 DOI: 10.1016/j.freeradbiomed.2016.07.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 01/12/2023]
Abstract
To meet energy demands, dorsal root ganglion (DRG) neurons harbor high mitochondrial content, which renders them acutely vulnerable to disruptions of energy homeostasis. While neurons typically rely on mitochondrial energy production and have not been associated with metabolic plasticity, new studies reveal that meclizine, a drug, recently linked to modulations of energy metabolism, protects neurons from insults that disrupt energy homeostasis. We show that meclizine rapidly enhances glycolysis in DRG neurons and that glycolytic metabolism is indispensable for meclizine-exerted protection of DRG neurons from hypoxic stress. We report that supplementation of meclizine during hypoxic exposure prevents ATP depletion, preserves NADPH and glutathione stores, curbs reactive oxygen species (ROS) and attenuates mitochondrial clustering in DRG neurites. Using extracellular flux analyzer, we show that in cultured DRG neurons meclizine mitigates hypoxia-induced loss of mitochondrial respiratory capacity. Respiratory capacity is a measure of mitochondrial fitness and cell ability to meet fluctuating energy demands and therefore, a key determinant of cellular fate. While meclizine is an 'old' drug with long record of clinical use, its ability to modulate energy metabolism has been uncovered only recently. Our findings documenting neuroprotection by meclizine in a setting of hypoxic stress reveal previously unappreciated metabolic plasticity of DRG neurons as well as potential for pharmacological harnessing of the newly discovered metabolic plasticity for protection of peripheral nervous system under mitochondria compromising conditions.
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Affiliation(s)
- Ming Zhuo
- Department of Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
| | - Murat F Gorgun
- Department of Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
| | - Ella W Englander
- Department of Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.
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22
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Valette J, Tiret B, Boumezbeur F. Experimental strategies for in vivo 13C NMR spectroscopy. Anal Biochem 2016; 529:216-228. [PMID: 27515993 DOI: 10.1016/j.ab.2016.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/24/2016] [Accepted: 08/04/2016] [Indexed: 11/15/2022]
Abstract
In vivo carbon-13 (13C) MRS opens unique insights into the metabolism of intact organisms, and has led to major advancements in the understanding of cellular metabolism under normal and pathological conditions in various organs such as skeletal muscles, the heart, the liver and the brain. However, the technique comes at the expense of significant experimental difficulties. In this review we focus on the experimental aspects of non-hyperpolarized 13C MRS in vivo. Some of the enrichment strategies which have been proposed so far are described; the various MRS acquisition paradigms to measure 13C labeling are then presented. Finally, practical aspects of 13C spectral quantification are discussed.
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Affiliation(s)
- Julien Valette
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), MIRCen, F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France.
| | - Brice Tiret
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), MIRCen, F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Fawzi Boumezbeur
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), NeuroSpin, F-91190 Gif-sur-Yvette, France
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23
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Tardito S, Oudin A, Ahmed SU, Fack F, Keunen O, Zheng L, Miletic H, Sakariassen PØ, Weinstock A, Wagner A, Lindsay SL, Hock AK, Barnett SC, Ruppin E, Mørkve SH, Lund-Johansen M, Chalmers AJ, Bjerkvig R, Niclou SP, Gottlieb E. Glutamine synthetase activity fuels nucleotide biosynthesis and supports growth of glutamine-restricted glioblastoma. Nat Cell Biol 2015; 17:1556-68. [PMID: 26595383 PMCID: PMC4663685 DOI: 10.1038/ncb3272] [Citation(s) in RCA: 387] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 10/19/2015] [Indexed: 12/27/2022]
Abstract
L-Glutamine (Gln) functions physiologically to balance the carbon and nitrogen requirements of tissues. It has been proposed that in cancer cells undergoing aerobic glycolysis, accelerated anabolism is sustained by Gln-derived carbons, which replenish the tricarboxylic acid (TCA) cycle (anaplerosis). However, it is shown here that in glioblastoma (GBM) cells, almost half of the Gln-derived glutamate (Glu) is secreted and does not enter the TCA cycle, and that inhibiting glutaminolysis does not affect cell proliferation. Moreover, Gln-starved cells are not rescued by TCA cycle replenishment. Instead, the conversion of Glu to Gln by glutamine synthetase (GS; cataplerosis) confers Gln prototrophy, and fuels de novo purine biosynthesis. In both orthotopic GBM models and in patients, (13)C-glucose tracing showed that GS produces Gln from TCA-cycle-derived carbons. Finally, the Gln required for the growth of GBM tumours is contributed only marginally by the circulation, and is mainly either autonomously synthesized by GS-positive glioma cells, or supplied by astrocytes.
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Affiliation(s)
- Saverio Tardito
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Switchback Road, Glasgow, G61 1BD, Scotland, UK
| | - Anaïs Oudin
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, L-1526, Luxembourg
| | - Shafiq U. Ahmed
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Fred Fack
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, L-1526, Luxembourg
| | - Olivier Keunen
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, L-1526, Luxembourg
| | - Liang Zheng
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Switchback Road, Glasgow, G61 1BD, Scotland, UK
| | - Hrvoje Miletic
- Kristian Gerhard Jebsen Brain Tumour Research Center, Department of Biomedicine, University of Bergen, Bergen, N-5009, Norway
| | - Per Øystein Sakariassen
- Kristian Gerhard Jebsen Brain Tumour Research Center, Department of Biomedicine, University of Bergen, Bergen, N-5009, Norway
| | - Adam Weinstock
- The Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Allon Wagner
- The Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Susan L. Lindsay
- Institute of Infection, Immunity and inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, Scotland, UK
| | - Andreas K. Hock
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Switchback Road, Glasgow, G61 1BD, Scotland, UK
| | - Susan C. Barnett
- Institute of Infection, Immunity and inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, Scotland, UK
| | - Eytan Ruppin
- The Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, 69978, Israel
- The Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | | | - Morten Lund-Johansen
- Department of Neurosurgery, Haukeland University Hospital, N-5021, Norway
- Department of Clinical Medicine, University of Bergen, N-5020, Norway
| | | | - Rolf Bjerkvig
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, L-1526, Luxembourg
- Kristian Gerhard Jebsen Brain Tumour Research Center, Department of Biomedicine, University of Bergen, Bergen, N-5009, Norway
| | - Simone P. Niclou
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, L-1526, Luxembourg
- Kristian Gerhard Jebsen Brain Tumour Research Center, Department of Biomedicine, University of Bergen, Bergen, N-5009, Norway
| | - Eyal Gottlieb
- Cancer Metabolism Research Unit, Cancer Research UK, Beatson Institute, Switchback Road, Glasgow, G61 1BD, Scotland, UK
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24
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Tiret B, Shestov AA, Valette J, Henry PG. Metabolic Modeling of Dynamic (13)C NMR Isotopomer Data in the Brain In Vivo: Fast Screening of Metabolic Models Using Automated Generation of Differential Equations. Neurochem Res 2015; 40:2482-92. [PMID: 26553273 DOI: 10.1007/s11064-015-1748-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 10/20/2015] [Accepted: 10/26/2015] [Indexed: 02/06/2023]
Abstract
Most current brain metabolic models are not capable of taking into account the dynamic isotopomer information available from fine structure multiplets in (13)C spectra, due to the difficulty of implementing such models. Here we present a new approach that allows automatic implementation of multi-compartment metabolic models capable of fitting any number of (13)C isotopomer curves in the brain. The new automated approach also makes it possible to quickly modify and test new models to best describe the experimental data. We demonstrate the power of the new approach by testing the effect of adding separate pyruvate pools in astrocytes and neurons, and adding a vesicular neuronal glutamate pool. Including both changes reduced the global fit residual by half and pointed to dilution of label prior to entry into the astrocytic TCA cycle as the main source of glutamine dilution. The glutamate-glutamine cycle rate was particularly sensitive to changes in the model.
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Affiliation(s)
- Brice Tiret
- Commissariat à l'Energie Atomique (CEA), Molecular Imaging Research Center (MIRCen), 92260, Fontenay-aux-Roses, France
| | - Alexander A Shestov
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, 2021 6th St SE, Minneapolis, MN, 55455, USA
| | - Julien Valette
- Commissariat à l'Energie Atomique (CEA), Molecular Imaging Research Center (MIRCen), 92260, Fontenay-aux-Roses, France
| | - Pierre-Gilles Henry
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, 2021 6th St SE, Minneapolis, MN, 55455, USA.
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25
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Niedenführ S, Wiechert W, Nöh K. How to measure metabolic fluxes: a taxonomic guide for (13)C fluxomics. Curr Opin Biotechnol 2014; 34:82-90. [PMID: 25531408 DOI: 10.1016/j.copbio.2014.12.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 12/24/2022]
Abstract
Metabolic reaction rates (fluxes) contribute fundamentally to our understanding of metabolic phenotypes and mechanisms of cellular regulation. Stable isotope-based fluxomics integrates experimental data with biochemical networks and mathematical modeling to 'measure' the in vivo fluxes within an organism that are not directly observable. In recent years, (13)C fluxomics has evolved into a technology with great experimental, analytical, and mathematical diversity. This review aims at establishing a unified taxonomy by means of which the various fluxomics methods can be compared to each other. By linking the developed modeling approaches to recent studies, their challenges and opportunities are put into perspective. The proposed classification serves as a guide for scientific 'travelers' who are striving to resolve research questions with the currently available (13)C fluxomics toolset.
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Affiliation(s)
| | - Wolfgang Wiechert
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Katharina Nöh
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
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