1
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Sorto P, Mäyränpää MI, Saksi J, Nuotio K, Ijäs P, Tuimala J, Vikatmaa P, Soinne L, Kovanen PT, Lindsberg PJ. Glutamine synthetase in human carotid plaque macrophages associates with features of plaque vulnerability: An immunohistological study. Atherosclerosis 2022; 352:18-26. [DOI: 10.1016/j.atherosclerosis.2022.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 04/15/2022] [Accepted: 05/11/2022] [Indexed: 11/02/2022]
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2
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Lee DS, Kim JE. P2X7 Receptor Augments LPS-Induced Nitrosative Stress by Regulating Nrf2 and GSH Levels in the Mouse Hippocampus. Antioxidants (Basel) 2022; 11:antiox11040778. [PMID: 35453462 PMCID: PMC9025791 DOI: 10.3390/antiox11040778] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 01/27/2023] Open
Abstract
P2X7 receptor (P2X7R) regulates inducible nitric oxide synthase (iNOS) expression/activity in response to various harmful insults. Since P2X7R deletion paradoxically decreases the basal glutathione (GSH) level in the mouse hippocampus, it is likely that P2X7R may increase the demand for GSH for the maintenance of the intracellular redox state or affect other antioxidant defense systems. Therefore, the present study was designed to elucidate whether P2X7R affects nuclear factor-erythroid 2-related factor 2 (Nrf2) activity/expression and GSH synthesis under nitrosative stress in response to lipopolysaccharide (LPS)-induced neuroinflammation. In the present study, P2X7R deletion attenuated iNOS upregulation and Nrf2 degradation induced by LPS. Compatible with iNOS induction, P2X7R deletion decreased S-nitrosylated (SNO)-cysteine production under physiological and post-LPS treated conditions. P2X7R deletion also ameliorated the decreases in GSH, glutathione synthetase, GS and ASCT2 levels concomitant with the reduced S-nitrosylations of GS and ASCT2 following LPS treatment. Furthermore, LPS upregulated cystine:glutamate transporter (xCT) and glutaminase in P2X7R+/+ mice, which were abrogated by P2X7R deletion. LPS did not affect GCLC level in both P2X7R+/+ and P2X7R−/− mice. Therefore, our findings indicate that P2X7R may augment LPS-induced neuroinflammation by leading to Nrf2 degradation, aberrant glutamate-glutamine cycle and impaired cystine/cysteine uptake, which would inhibit GSH biosynthesis. Therefore, we suggest that the targeting of P2X7R, which would exert nitrosative stress with iNOS in a positive feedback manner, may be one of the important therapeutic strategies of nitrosative stress under pathophysiological conditions.
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3
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Lu V, Roy IJ, Torres A, Joly JH, Ahsan FM, Graham NA, Teitell MA. Glutamine-dependent signaling controls pluripotent stem cell fate. Dev Cell 2022; 57:610-623.e8. [PMID: 35216682 PMCID: PMC8930616 DOI: 10.1016/j.devcel.2022.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 11/01/2021] [Accepted: 01/31/2022] [Indexed: 12/30/2022]
Abstract
Human pluripotent stem cells (hPSCs) can self-renew indefinitely or can be induced to differentiate. We previously showed that exogenous glutamine (Gln) withdrawal biased hPSC differentiation toward ectoderm and away from mesoderm. We revealed that, although all three germ lineages are capable of de novo Gln synthesis, only ectoderm generates sufficient Gln to sustain cell viability and differentiation, and this finding clarifies lineage fate restrictions under Gln withdrawal. Furthermore, we found that Gln acts as a signaling molecule for ectoderm that supersedes lineage-specifying cytokine induction. In contrast, Gln in mesoderm and endoderm is the preferred precursor of α-ketoglutarate without a direct signaling role. Our work raises a question about whether the nutrient environment functions directly in cell differentiation during development. Interestingly, transcriptome analysis of a gastrulation-stage human embryo shows that unique Gln enzyme-encoding gene expression patterns may also distinguish germ lineages in vivo. Together, our study suggests that intracellular Gln may help coordinate differentiation of the three germ layers.
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Affiliation(s)
- Vivian Lu
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Irena J Roy
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Alejandro Torres
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, CA, USA
| | - James H Joly
- Mork Family Department of Chemical Engineering and Materials Science, Los Angeles, CA 90089, USA
| | - Fasih M Ahsan
- Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA, USA
| | - Nicholas A Graham
- Mork Family Department of Chemical Engineering and Materials Science, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA; Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Michael A Teitell
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California at Los Angeles, Los Angeles, CA, USA; Department of Bioengineering, Department of Pediatrics, California NanoSystems Institute, and Broad Center for Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.
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4
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You J, Huang H, Chan CTY, Li L. Pathological Targets for Treating Temporal Lobe Epilepsy: Discoveries From Microscale to Macroscale. Front Neurol 2022; 12:779558. [PMID: 35069411 PMCID: PMC8777077 DOI: 10.3389/fneur.2021.779558] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common and severe types of epilepsy, characterized by intractable, recurrent, and pharmacoresistant seizures. Histopathology of TLE is mostly investigated through observing hippocampal sclerosis (HS) in adults, which provides a robust means to analyze the related histopathological lesions. However, most pathological processes underlying the formation of these lesions remain elusive, as they are difficult to detect and observe. In recent years, significant efforts have been put in elucidating the pathophysiological pathways contributing to TLE epileptogenesis. In this review, we aimed to address the new and unrecognized neuropathological discoveries within the last 5 years, focusing on gene expression (miRNA and DNA methylation), neuronal peptides (neuropeptide Y), cellular metabolism (mitochondria and ion transport), cellular structure (microtubule and extracellular matrix), and tissue-level abnormalities (enlarged amygdala). Herein, we describe a range of biochemical mechanisms and their implication for epileptogenesis. Furthermore, we discuss their potential role as a target for TLE prevention and treatment. This review article summarizes the latest neuropathological discoveries at the molecular, cellular, and tissue levels involving both animal and patient studies, aiming to explore epileptogenesis and highlight new potential targets in the diagnosis and treatment of TLE.
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Affiliation(s)
- Jing You
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Haiyan Huang
- Department of Nutrition and Food Science, Texas Women University, Denton, TX, United States
| | - Clement T Y Chan
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Lin Li
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States.,Department of Neurology, University of California, Los Angeles, Los Angeles, CA, United States
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5
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Affiliation(s)
- Vishal D Naik
- Department of Obstetrics & Gynecology, C.S. Mott Center for Human Growth and Development, School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Jehoon Lee
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Shannon Washburn
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Jayanth Ramadoss
- J. Ramadoss, Department of Obstetrics & Gynecology and Department of Physiology, 275 E Hancock St, C.S. Mott Center for Human Growth and Development, Rm 195, School of Medicine, Wayne State University, Detroit, MI 48201, USA. E-mail:
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6
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Liebe H, Liebe F, Sponder G, Hedtrich S, Stumpff F. Beyond Ca 2+ signalling: the role of TRPV3 in the transport of NH 4. Pflugers Arch 2021; 473:1859-1884. [PMID: 34664138 PMCID: PMC8599221 DOI: 10.1007/s00424-021-02616-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/11/2022]
Abstract
Mutations of TRPV3 lead to severe dermal hyperkeratosis in Olmsted syndrome, but whether the mutants are trafficked to the cell membrane or not is controversial. Even less is known about TRPV3 function in intestinal epithelia, although research on ruminants and pigs suggests an involvement in the uptake of NH4+. It was the purpose of this study to measure the permeability of the human homologue (hTRPV3) to NH4+, to localize hTRPV3 in human skin equivalents, and to investigate trafficking of the Olmsted mutant G573S. Immunoblotting and immunostaining verified the successful expression of hTRPV3 in HEK-293 cells and Xenopus oocytes with trafficking to the cell membrane. Human skin equivalents showed distinct staining of the apical membrane of the top layer of keratinocytes with cytosolic staining in the middle layers. Experiments with pH-sensitive microelectrodes on Xenopus oocytes demonstrated that acidification by NH4+ was significantly greater when hTRPV3 was expressed. Single-channel measurements showed larger conductances in overexpressing Xenopus oocytes than in controls. In whole-cell experiments on HEK-293 cells, both enantiomers of menthol stimulated influx of NH4+ in hTRPV3 expressing cells, but not in controls. Expression of the mutant G573S greatly reduced cell viability with partial rescue via ruthenium red. Immunofluorescence confirmed cytosolic expression, with membrane staining observed in a very small number of cells. We suggest that expression of TRPV3 by epithelia may have implications not just for Ca2+ signalling, but also for nitrogen metabolism. Models suggesting how influx of NH4+ via TRPV3 might stimulate skin cornification or intestinal NH4+ transport are discussed.
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Affiliation(s)
- Hendrik Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.,Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Franziska Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Sarah Hedtrich
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Friederike Stumpff
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
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7
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Ferreira CR, Martinelli D, Blau N. Clinical and biochemical footprints of inherited metabolic diseases. VI. Metabolic dermatoses. Mol Genet Metab 2021; 134:87-95. [PMID: 34304991 PMCID: PMC8578301 DOI: 10.1016/j.ymgme.2021.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/10/2021] [Accepted: 07/13/2021] [Indexed: 12/15/2022]
Abstract
Cutaneous signs and symptoms may facilitate the diagnosis or can help in identifying complications or side effects of overtreatment of inherited metabolic diseases. The principal manifestations can be grouped into vascular lesions, ichthyosis, papular and nodular skin lesions, abnormal pigmentation, photosensitivity, skin laxity, hair shaft involvement, and nail abnormalities. We have summarized associations of these cutaneous signs and symptoms in 252 inherited metabolic diseases. This represents the sixth of a series of articles attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.
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Affiliation(s)
- Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Diego Martinelli
- Division of Metabolism, Department of Pediatric Subspecialties, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Nenad Blau
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland.
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8
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Frieg B, Görg B, Gohlke H, Häussinger D. Glutamine synthetase as a central element in hepatic glutamine and ammonia metabolism: novel aspects. Biol Chem 2021; 402:1063-1072. [PMID: 33962502 DOI: 10.1515/hsz-2021-0166] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/22/2021] [Indexed: 12/27/2022]
Abstract
Glutamine synthetase (GS) in the liver is expressed in a small perivenous, highly specialized hepatocyte population and is essential for the maintenance of low, non-toxic ammonia levels in the organism. However, GS activity can be impaired by tyrosine nitration of the enzyme in response to oxidative/nitrosative stress in a pH-sensitive way. The underlying molecular mechanism as investigated by combined molecular simulations and in vitro experiments indicates that tyrosine nitration can lead to a fully reversible and pH-sensitive regulation of protein function. This approach was also used to understand the functional consequences of several recently described point mutations of human GS with clinical relevance and to suggest an approach to restore impaired GS activity.
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Affiliation(s)
- Benedikt Frieg
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Boris Görg
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany
| | - Holger Gohlke
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany
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9
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Sandhu MRS, Gruenbaum BF, Gruenbaum SE, Dhaher R, Deshpande K, Funaro MC, Lee TSW, Zaveri HP, Eid T. Astroglial Glutamine Synthetase and the Pathogenesis of Mesial Temporal Lobe Epilepsy. Front Neurol 2021; 12:665334. [PMID: 33927688 PMCID: PMC8078591 DOI: 10.3389/fneur.2021.665334] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
The enzyme glutamine synthetase (GS), also referred to as glutamate ammonia ligase, is abundant in astrocytes and catalyzes the conversion of ammonia and glutamate to glutamine. Deficiency or dysfunction of astrocytic GS in discrete brain regions have been associated with several types of epilepsy, including medically-intractable mesial temporal lobe epilepsy (MTLE), neocortical epilepsies, and glioblastoma-associated epilepsy. Moreover, experimental inhibition or deletion of GS in the entorhinal-hippocampal territory of laboratory animals causes an MTLE-like syndrome characterized by spontaneous, recurrent hippocampal-onset seizures, loss of hippocampal neurons, and in some cases comorbid depressive-like features. The goal of this review is to summarize and discuss the possible roles of astroglial GS in the pathogenesis of epilepsy.
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Affiliation(s)
| | - Benjamin F Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL, United States
| | - Shaun E Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL, United States
| | - Roni Dhaher
- Department of Neurosurgery, New Haven, CT, United States
| | | | - Melissa C Funaro
- Harvey Cushing/John Hay Whitney Medical Library, Yale University, New Haven, CT, United States
| | | | - Hitten P Zaveri
- Department of Neurology, Yale School of Medicine, New Haven, CT, United States
| | - Tore Eid
- Department of Laboratory Medicine, New Haven, CT, United States
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10
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Egerton A, Dunn JT, Singh N, Yu Z, O'Doherty J, Koychev I, Webb J, Claridge S, Turkheimer FE, Marsden PK, Hammers A, Gee A. Evaluation of [ 13N]ammonia positron emission tomography as a potential method for quantifying glutamine synthetase activity in the human brain. EJNMMI Res 2020; 10:146. [PMID: 33270177 PMCID: PMC7714883 DOI: 10.1186/s13550-020-00731-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/21/2020] [Indexed: 11/22/2022] Open
Abstract
PURPOSE The conversion of synaptic glutamate to glutamine in astrocytes by glutamine synthetase (GS) is critical to maintaining healthy brain activity and may be disrupted in several brain disorders. As the GS catalysed conversion of glutamate to glutamine requires ammonia, we evaluated whether [13N]ammonia positron emission tomography (PET) could reliability quantify GS activity in humans. METHODS In this test-retest study, eight healthy volunteers each received two dynamic [13N]ammonia PET scans on the morning and afternoon of the same day. Each [13N]ammonia scan was preceded by a [15O]water PET scan to account for effects of cerebral blood flow (CBF). RESULTS Concentrations of radioactive metabolites in arterial blood were available for both sessions in five of the eight subjects. Our results demonstrated that kinetic modelling was unable to reliably distinguish estimates of the kinetic rate constant k3 (related to GS activity) from K1 (related to [13N]ammonia brain uptake), and indicated a non-negligible back-flux of [13N] to blood (k2). Model selection favoured a reversible one-tissue compartmental model, and [13N]ammonia K1 correlated reliably (r2 = 0.72-0.92) with [15O]water CBF. CONCLUSION The [13N]ammonia PET method was unable to reliably estimate GS activity in the human brain but may provide an alternative index of CBF.
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Affiliation(s)
- Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK.
| | - Joel T Dunn
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
| | - Nisha Singh
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 7AF, UK
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, UK
| | - Zilin Yu
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
| | - Jim O'Doherty
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
- Clinical Imaging Research Centre, National University of Singapore, Singapore, 117599, Singapore
| | - Ivan Koychev
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 16 De Crespigny Park, London, SE5 8AF, UK
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, UK
| | - Jessica Webb
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
| | - Simon Claridge
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
| | - Federico E Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 7AF, UK
| | - Paul K Marsden
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
| | - Alexander Hammers
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
| | - Antony Gee
- School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, SE1 7EH, UK
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11
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Proteomics reveals that quinoa bioester promotes replenishing effects in epidermal tissue. Sci Rep 2020; 10:19392. [PMID: 33173110 PMCID: PMC7655866 DOI: 10.1038/s41598-020-76325-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/27/2020] [Indexed: 12/21/2022] Open
Abstract
The continuous search for natural products that attenuate age-related losses has increasingly gained notice; among them, those applicable for skin care have drawn significant attention. The bioester generated from the Chenopodium quinoa’s oil is a natural-origin ingredient described to produce replenishing skin effects. With this as motivation, we used shotgun proteomics to study the effects of quinoa bioester on human reconstructed epidermis tridimensional cell cultures after 0, 3, 6, 12, 24, and 48 h of exposure. Our experimental setup employed reversed-phase nano-chromatography coupled online with an Orbitrap-XL and PatternLab for proteomics as the data analysis tool. Extracted ion chromatograms were obtained as surrogates for relative peptide quantitation. Our findings spotlight proteins with increased abundance, as compared to the untreated cell culture counterparts at the same timepoints, that were related to preventing premature aging, homeostasis, tissue regeneration, protection against ultraviolet radiation and oxidative damage.
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12
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Zhou Y, Eid T, Hassel B, Danbolt NC. Novel aspects of glutamine synthetase in ammonia homeostasis. Neurochem Int 2020; 140:104809. [DOI: 10.1016/j.neuint.2020.104809] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
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13
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Roifman M, Niles KM, MacNeil L, Blaser S, Noor A, Godoy R, van Mieghem T, Ryan G, Seaward G, Sondheimer N, Mercimek-Andrews S, Schulze A, Hewson S, Ovadia A, Chitayat D, Morgen EK, Hojilla C, Kolomietz E, Watkins N, Häberle J, Shannon P. Homozygous GLUL deletion is embryonically viable and leads to glutamine synthetase deficiency. Clin Genet 2020; 98:613-619. [PMID: 32888207 DOI: 10.1111/cge.13844] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/28/2020] [Accepted: 08/31/2020] [Indexed: 12/17/2022]
Abstract
Glutamine synthetase (GS) is the enzyme responsible for the biosynthesis of glutamine, providing the only source of endogenous glutamine necessary for several critical metabolic and developmental pathways. GS deficiency, caused by pathogenic variants in the glutamate-ammonia ligase (GLUL) gene, is a rare autosomal recessive inborn error of metabolism characterized by systemic glutamine deficiency, persistent moderate hyperammonemia, and clinically devastating seizures and multi-organ failure shortly after birth. The four cases reported thus far were caused by homozygous GLUL missense variants. We report a case of GS deficiency caused by homozygous GLUL gene deletion, diagnosed prenatally and likely representing the most severe end of the spectrum. We expand the known phenotype of this rare condition with novel dysmorphic, radiographic and neuropathologic features identified on post-mortem examination. The biallelic deletion identified in this case also included the RNASEL gene and was associated with immune dysfunction in the fetus. This case demonstrates that total absence of the GLUL gene in humans is viable beyond the embryonic period, despite the early embryonic lethality found in GLUL animal models.
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Affiliation(s)
- Maian Roifman
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada.,Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Kirsten M Niles
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada.,Division of Maternal Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Lauren MacNeil
- Department of Pathology and Laboratory Medicine, Hospital for Sick Children, University of Toronto, Toronto, Canada.,Department of Medical Genetics, Alberta Precision Laboratories, University of Alberta, Edmonton, Alberta, Canada
| | - Susan Blaser
- Division of Neuroradiology, Department of Diagnostic Imaging, Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Abdul Noor
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Ruth Godoy
- Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Tim van Mieghem
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Greg Ryan
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Gareth Seaward
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Neal Sondheimer
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Saadet Mercimek-Andrews
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Andreas Schulze
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Stacy Hewson
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Adi Ovadia
- Division of Immunology, Department of Pediatrics, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, Holon, Israel.,Department of Pediatrics, Edith Wolfson Medical Center, Holon, Israel
| | - David Chitayat
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada.,Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Eric K Morgen
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada.,BioAge Labs, Richmond, California, USA
| | - Carlo Hojilla
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Elena Kolomietz
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Nicholas Watkins
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital, University of Zurich, Zurich, Switzerland
| | - Patrick Shannon
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Canada
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14
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Eid T, Lee TSW, Patrylo P, Zaveri HP. Astrocytes and Glutamine Synthetase in Epileptogenesis. J Neurosci Res 2019; 97:1345-1362. [PMID: 30022509 PMCID: PMC6338538 DOI: 10.1002/jnr.24267] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/15/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022]
Abstract
The cellular, molecular, and metabolic mechanisms that underlie the development of mesial temporal lobe epilepsy are incompletely understood. Here we review the role of astrocytes in epilepsy development (a.k.a. epileptogenesis), particularly astrocyte pathologies related to: aquaporin 4, the inwardly rectifying potassium channel Kir4.1, monocarboxylate transporters MCT1 and MCT2, excitatory amino acid transporters EAAT1 and EAAT2, and glutamine synthetase. We propose that inhibition, dysfunction or loss of astrocytic glutamine synthetase is an important causative factor for some epilepsies, particularly mesial temporal lobe epilepsy and glioblastoma-associated epilepsy. We postulate that the regulatory mechanisms of glutamine synthetase as well as the downstream effects of glutamine synthetase dysfunction, represent attractive, new targets for antiepileptogenic interventions. Currently, no antiepileptogenic therapies are available for human use. The discovery of such interventions is important as it will fundamentally change the way we approach epilepsy by preventing the disease from ever becoming manifest after an epileptogenic insult to the brain.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine
- Department of Molecular Medicine, University of Oslo
| | | | - Peter Patrylo
- Department of Physiology, Southern Illinois University School of Medicine
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15
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Insufficient glutamine synthetase activity during synaptogenesis causes spatial memory impairment in adult mice. Sci Rep 2019; 9:252. [PMID: 30670758 PMCID: PMC6342969 DOI: 10.1038/s41598-018-36619-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 11/21/2018] [Indexed: 12/11/2022] Open
Abstract
Glutamatergic synapses constitute a major excitatory neurotransmission system and are regulated by glutamate/glutamine (Gln) cycling between neurons and astrocytes. Gln synthetase (GS) produced by astrocytes plays an important role in maintaining the cycle. However, the significance of GS during synaptogenesis has not been clarified. GS activity and expression significantly increase from postnatal day (PD) 7 to 21, and GS is expressed prior to glial fibrillary acidic protein (GFAP) and is more abundant than GFAP throughout synaptogenesis. These observations suggest that GS plays an important role in synaptogenesis. We investigated this by inhibiting GS activity in neonatal mice and assessed the consequences in adult animals. Lower expression levels of GS and GFAP were found in the CA3 region of the hippocampus but not in the CA1 region. Moreover, synaptic puncta and glutamatergic neurotransmission were also decreased in CA3. Behaviorally, mice with inhibited GS during synaptogenesis showed spatial memory-related impairment as adults. These results suggest that postnatal GS activity is important for glutamatergic synapse development in CA3.
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16
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Mallet M, Weiss N, Thabut D, Rudler M. Why and when to measure ammonemia in cirrhosis? Clin Res Hepatol Gastroenterol 2018; 42:505-511. [PMID: 29551609 DOI: 10.1016/j.clinre.2018.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/29/2018] [Accepted: 01/31/2018] [Indexed: 02/06/2023]
Abstract
Hyperammonemia plays a key role in the pathophysiology of hepatic encephalopathy (HE) and most HE treatments are ammonia-lowering drugs. However, the usefulness of measuring ammonemia in routine practice remains controversial and not recommended systematically even when neurological symptoms are present. First, ammonemia measurement should be carefully performed in order to avoid a falsely elevated result. When performed, a normal ammonemia in a cirrhotic patient with neurological symptoms should lead to reconsider the diagnosis of HE. Indeed, literature data show that most cirrhotic patients with HE have an elevated ammonemia, which is however individually poorly correlated with the severity of symptoms. Nevertheless, elevated ammonemia seems to be a factor of bad prognosis in cirrhosis. A decrease in ammonemia after treatments is well proven but it is not determined whether it is associated with clinical efficacy. Repeated measurements could be useful in this context, especially in non-responders, to help differentiating other causes of encephalopathy, such as drug induced. In acute liver failure, the prognostic value of hyperammonemia is well described and could help an early recognition the most severe forms of this disease. We will also discuss how integrating ammonemia into the diagnostic work-up of liver failure and/or encephalopathy. Ammonemia is also essential to diagnose urea cycle disorders or drug toxicity that both need specific interventions.
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Affiliation(s)
- Maxime Mallet
- Unité de soins intensifs d'hépatologie, service d'hépato-gastro-entérologie, groupe hospitalier Pitié-Salpêtrière Charles-Foix, Assistance publique-Hôpitaux de Paris, Paris, & Sorbonne universités, UPMC Université Paris 06, 47, boulevard de l'Hôpital, 75013 Paris, France; Brain Liver Pitié-Salpêtrière (BLIPS) study group, 47, boulevard de l'Hôpital, 75013, Paris, France
| | - Nicolas Weiss
- Brain Liver Pitié-Salpêtrière (BLIPS) study group, 47, boulevard de l'Hôpital, 75013, Paris, France; Sorbonne universités, UPMC université Paris 06, France & unité de réanimation neurologique, département de neurologie, groupe hospitalier Pitié-Salpêtrière Charles-Foix, pôle des maladies du système nerveux et institut de neurosciences translationnelles, IHU-A-ICM, 75013 Paris, France
| | - Dominique Thabut
- Unité de soins intensifs d'hépatologie, service d'hépato-gastro-entérologie, groupe hospitalier Pitié-Salpêtrière Charles-Foix, Assistance publique-Hôpitaux de Paris, Paris, & Sorbonne universités, UPMC Université Paris 06, 47, boulevard de l'Hôpital, 75013 Paris, France; Brain Liver Pitié-Salpêtrière (BLIPS) study group, 47, boulevard de l'Hôpital, 75013, Paris, France
| | - Marika Rudler
- Unité de soins intensifs d'hépatologie, service d'hépato-gastro-entérologie, groupe hospitalier Pitié-Salpêtrière Charles-Foix, Assistance publique-Hôpitaux de Paris, Paris, & Sorbonne universités, UPMC Université Paris 06, 47, boulevard de l'Hôpital, 75013 Paris, France; Brain Liver Pitié-Salpêtrière (BLIPS) study group, 47, boulevard de l'Hôpital, 75013, Paris, France.
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17
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Obara T, Ishikuro M, Tamiya G, Ueki M, Yamanaka C, Mizuno S, Kikuya M, Metoki H, Matsubara H, Nagai M, Kobayashi T, Kamiyama M, Watanabe M, Kakuta K, Ouchi M, Kurihara A, Fukuchi N, Yasuhara A, Inagaki M, Kaga M, Kure S, Kuriyama S. Potential identification of vitamin B6 responsiveness in autism spectrum disorder utilizing phenotype variables and machine learning methods. Sci Rep 2018; 8:14840. [PMID: 30287864 PMCID: PMC6172273 DOI: 10.1038/s41598-018-33110-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/19/2018] [Indexed: 12/15/2022] Open
Abstract
We investigated whether machine learning methods could potentially identify a subgroup of persons with autism spectrum disorder (ASD) who show vitamin B6 responsiveness by selected phenotype variables. We analyzed the existing data from our intervention study with 17 persons. First, we focused on signs and biomarkers that have been identified as candidates for vitamin B6 responsiveness indicators. Second, we conducted hypothesis testing among these selected variables and their combinations. Finally, we further investigated the results by conducting cluster analyses with two different algorithms, affinity propagation and k-medoids. Statistically significant variables for vitamin B6 responsiveness, including combination of hypersensitivity to sound and clumsiness, and plasma glutamine level, were included. As an a priori variable, the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) scores was also included. The affinity propagation analysis showed good classification of three potential vitamin B6-responsive persons with ASD. The k-medoids analysis also showed good classification. To our knowledge, this is the first study to attempt to identify subgroup of persons with ASD who show specific treatment responsiveness using selected phenotype variables. We applied machine learning methods to further investigate these variables' ability to identify this subgroup of ASD, even when only a small sample size was available.
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Affiliation(s)
- Taku Obara
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
- Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Miyagi, Japan
| | - Mami Ishikuro
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Gen Tamiya
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Statistical Genetics Team, RIKEN Center for Advanced Intelligence Project, Chuo-ku, Tokyo, Japan
| | - Masao Ueki
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Statistical Genetics Team, RIKEN Center for Advanced Intelligence Project, Chuo-ku, Tokyo, Japan
| | - Chizuru Yamanaka
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Satoshi Mizuno
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Masahiro Kikuya
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Hygiene and Public Health, School of Medicine, Teikyo University, Tokyo, Japan
| | - Hirohito Metoki
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Hiroko Matsubara
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Masato Nagai
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Tomoko Kobayashi
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Pediatrics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Machiko Kamiyama
- Department of Education, Art and Science, Yamagata University, Yamagata, Yamagata, Japan
| | - Mikako Watanabe
- Department of Pediatrics, Saka General Hospital, Shiogama, Miyagi, Japan
| | | | - Minami Ouchi
- Department of Pediatrics, NTT Medical Center Tokyo, Shinagawa-ku, Tokyo, Japan
- Bunkyo Education Center, Bunkyo-ku, Tokyo, Japan
| | - Aki Kurihara
- Fujimoto Shinjuku Hospital, Shinjuku-ku, Tokyo, Japan
| | - Naru Fukuchi
- Department of Psychiatry, Miyagi Psychiatric Center, Natori, Miyagi, Japan
- Miyagi Disaster Mental Health Care Center, Sendai, Miyagi, Japan
| | | | - Masumi Inagaki
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Makiko Kaga
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
- Tokyo Metropolitan Tobu Medical Center for Children with Developmental Disabilities, Koto-ku, Tokyo, Japan
| | - Shigeo Kure
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan
- Department of Pediatrics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Shinichi Kuriyama
- Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Miyagi, Japan.
- Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan.
- Department of Disaster Public Health, International Research Institute of Disaster Science, Tohoku University, Sendai, Miyagi, Japan.
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18
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Crispim M, Damasceno FS, Hernández A, Barisón MJ, Pretto Sauter I, Souza Pavani R, Santos Moura A, Pral EMF, Cortez M, Elias MC, Silber AM. The glutamine synthetase of Trypanosoma cruzi is required for its resistance to ammonium accumulation and evasion of the parasitophorous vacuole during host-cell infection. PLoS Negl Trop Dis 2018; 12:e0006170. [PMID: 29320490 PMCID: PMC5779702 DOI: 10.1371/journal.pntd.0006170] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/23/2018] [Accepted: 12/16/2017] [Indexed: 11/19/2022] Open
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, consumes glucose and amino acids depending on the environmental availability of each nutrient during its complex life cycle. For example, amino acids are the major energy and carbon sources in the intracellular stages of the T. cruzi parasite, but their consumption produces an accumulation of NH4+ in the environment, which is toxic. These parasites do not have a functional urea cycle to secrete excess nitrogen as low-toxicity waste. Glutamine synthetase (GS) plays a central role in regulating the carbon/nitrogen balance in the metabolism of most living organisms. We show here that the gene TcGS from T. cruzi encodes a functional glutamine synthetase; it can complement a defect in the GLN1 gene from Saccharomyces cerevisiae and utilizes ATP, glutamate and ammonium to yield glutamine in vitro. Overall, its kinetic characteristics are similar to other eukaryotic enzymes, and it is dependent on divalent cations. Its cytosolic/mitochondrial localization was confirmed by immunofluorescence. Inhibition by Methionine sulfoximine revealed that GS activity is indispensable under excess ammonium conditions. Coincidently, its expression levels are maximal in the amastigote stage of the life cycle, when amino acids are preferably consumed, and NH4+ production is predictable. During host-cell invasion, TcGS is required for the parasite to escape from the parasitophorous vacuole, a process sine qua non for the parasite to replicate and establish infection in host cells. These results are the first to establish a link between the activity of a metabolic enzyme and the ability of a parasite to reach its intracellular niche to replicate and establish host-cell infection.
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Affiliation(s)
- Marcell Crispim
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Flávia Silva Damasceno
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Agustín Hernández
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - María Julia Barisón
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Ismael Pretto Sauter
- Immunobiology of Leishmania-Macrophage Interaction Laboratory, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Raphael Souza Pavani
- Special Laboratory of Cell Cycle, Center of Toxins, Immunology and Cell Signalling, Butantan Institute, São Paulo, SP, Brazil
| | - Alexandre Santos Moura
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Elizabeth Mieko Furusho Pral
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Mauro Cortez
- Immunobiology of Leishmania-Macrophage Interaction Laboratory, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Maria Carolina Elias
- Special Laboratory of Cell Cycle, Center of Toxins, Immunology and Cell Signalling, Butantan Institute, São Paulo, SP, Brazil
| | - Ariel Mariano Silber
- Laboratory of Biochemistry of Tryps—LaBTryps, Department of Parasitology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
- * E-mail:
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19
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Affiliation(s)
- Callum Livingstone
- Clinical Biochemistry Department, Royal Surrey County Hospital, NHS Foundation Trust, Guildford, UK
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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20
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Zhang J, Pavlova NN, Thompson CB. Cancer cell metabolism: the essential role of the nonessential amino acid, glutamine. EMBO J 2017; 36:1302-1315. [PMID: 28420743 DOI: 10.15252/embj.201696151] [Citation(s) in RCA: 409] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
Biochemistry textbooks and cell culture experiments seem to be telling us two different things about the significance of external glutamine supply for mammalian cell growth and proliferation. Despite the fact that glutamine is a nonessential amino acid that can be synthesized by cells from glucose-derived carbons and amino acid-derived ammonia, most mammalian cells in tissue culture cannot proliferate or even survive in an environment that does not contain millimolar levels of glutamine. Not only are the levels of glutamine in standard tissue culture media at least ten-fold higher than other amino acids, but glutamine is also the most abundant amino acid in the human bloodstream, where it is assiduously maintained at approximately 0.5 mM through a combination of dietary uptake, de novo synthesis, and muscle protein catabolism. The complex metabolic logic of the proliferating cancer cells' appetite for glutamine-which goes far beyond satisfying their protein synthesis requirements-has only recently come into focus. In this review, we examine the diversity of biosynthetic and regulatory uses of glutamine and their role in proliferation, stress resistance, and cellular identity, as well as discuss the mechanisms that cells utilize in order to adapt to glutamine limitation.
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Affiliation(s)
- Ji Zhang
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Natalya N Pavlova
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Craig B Thompson
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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21
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Minireview on Glutamine Synthetase Deficiency, an Ultra-Rare Inborn Error of Amino Acid Biosynthesis. BIOLOGY 2016; 5:biology5040040. [PMID: 27775558 PMCID: PMC5192420 DOI: 10.3390/biology5040040] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/03/2016] [Accepted: 10/12/2016] [Indexed: 12/25/2022]
Abstract
Glutamine synthetase (GS) is a cytosolic enzyme that produces glutamine, the most abundant free amino acid in the human body. Glutamine is a major substrate for various metabolic pathways, and is thus an important factor for the functioning of many organs; therefore, deficiency of glutamine due to a defect in GS is incompatible with normal life. Mutations in the human GLUL gene (encoding for GS) can cause an ultra-rare recessive inborn error of metabolism—congenital glutamine synthetase deficiency. This disease was reported until now in only three unrelated patients, all of whom suffered from neonatal onset severe epileptic encephalopathy. The hallmark of GS deficiency in these patients was decreased levels of glutamine in body fluids, associated with chronic hyperammonemia. This review aims at recapitulating the clinical history of the three known patients with congenital GS deficiency and summarizes the findings from studies done along with the work-up of these patients. It is the aim of this paper to convince the reader that (i) this disorder is possibly underdiagnosed, since decreased concentrations of metabolites do not receive the attention they deserve; and (ii) early detection of GS deficiency may help to improve the outcome of patients who could be treated early with metabolites that are lacking in this condition.
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22
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Issoglio FM, Campolo N, Zeida A, Grune T, Radi R, Estrin DA, Bartesaghi S. Exploring the Catalytic Mechanism of Human Glutamine Synthetase by Computer Simulations. Biochemistry 2016; 55:5907-5916. [DOI: 10.1021/acs.biochem.6b00822] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Federico M. Issoglio
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Ari Zeida
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Tilman Grune
- German Institute of Human Nutrition (DIfE) Potsdam-Rehbrücke, Department of Molecular Toxicology, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | | | - Dario A. Estrin
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Silvina Bartesaghi
- Departamento
de Educación Médica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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23
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Ryu JM, Lee SH, Seong JK, Han HJ. Glutamine contributes to maintenance of mouse embryonic stem cell self-renewal through PKC-dependent downregulation of HDAC1 and DNMT1/3a. Cell Cycle 2016; 14:3292-305. [PMID: 26375799 DOI: 10.1080/15384101.2015.1087620] [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] [Indexed: 02/02/2023] Open
Abstract
Although glutamine (Gln) is not an essential amino acid, it is considered a critical substrate in many key metabolic processes that control a variety of physiological functions and are involved in regulating early embryonic development. Thus, we investigated the effect of Gln on regulation of mouse embryonic stem cell (mESC) self-renewal and related signaling pathways. Gln deprivation decreased Oct4 expression as well as expression of cell cycle regulatory proteins. However, Gln treatment retained the expression of cell cycle regulatory proteins and the Oct4 in mESCs, which were blocked by compound 968 (a glutaminase inhibitor). In addition, Gln stimulated PI3K/Akt pathway, which subsequently elicited PKCϵ translocation to membrane without an influx of intracellular Ca(2+). Inhibition of Akt and PKC blocked Gln-induced Oct4 expression and proliferation. Gln also stimulated mTOR phosphorylation in a time-dependent manner, which abolished by PKC inhibition. Furthermore, Gln increased the cellular population of both Oct4 and bromodeoxyuridine positive cells, suggesting that Gln regulates self-renewal ability of mESCs. Gln induced a decrease in HDAC1, but not in HDAC2, which were blocked by PKC inhibitors. Gln treatment resulted in an increase in global histone acetylation and methylation. In addition, Gln significantly reduced methylation of the Oct4 promoter region through decrease in DNMT1 and DNMT3a expression, which were blocked by PKC and HDAC inhibitors. In conclusion, Gln stimulates mESC proliferation and maintains mESC undifferentiation status through transcription regulation via the Akt, PKCϵ, and mTOR signaling pathways.
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Affiliation(s)
- Jung Min Ryu
- a Department of Veterinary Physiology ; College of Veterinary Medicine, Seoul National University ; Seoul , Korea
| | - Sang Hun Lee
- b Medical Science Research Institute, Soonchunhyang University Seoul Hospital ; Seoul , Korea
| | - Je Kyung Seong
- c BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University ; Seoul , Korea.,d Department of Anatomy and Cell Biology ; Korea Mouse Phenotyping Center (KMPC), College of Veterinary Medicine, Seoul National University ; Seoul , Korea
| | - Ho Jae Han
- a Department of Veterinary Physiology ; College of Veterinary Medicine, Seoul National University ; Seoul , Korea.,c BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University ; Seoul , Korea
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24
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Frieg B, Görg B, Homeyer N, Keitel V, Häussinger D, Gohlke H. Molecular Mechanisms of Glutamine Synthetase Mutations that Lead to Clinically Relevant Pathologies. PLoS Comput Biol 2016; 12:e1004693. [PMID: 26836257 PMCID: PMC4737493 DOI: 10.1371/journal.pcbi.1004693] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 12/03/2015] [Indexed: 12/15/2022] Open
Abstract
Glutamine synthetase (GS) catalyzes ATP-dependent ligation of ammonia and glutamate to glutamine. Two mutations of human GS (R324C and R341C) were connected to congenital glutamine deficiency with severe brain malformations resulting in neonatal death. Another GS mutation (R324S) was identified in a neurologically compromised patient. However, the molecular mechanisms underlying the impairment of GS activity by these mutations have remained elusive. Molecular dynamics simulations, free energy calculations, and rigidity analyses suggest that all three mutations influence the first step of GS catalytic cycle. The R324S and R324C mutations deteriorate GS catalytic activity due to loss of direct interactions with ATP. As to R324S, indirect, water-mediated interactions reduce this effect, which may explain the suggested higher GS residual activity. The R341C mutation weakens ATP binding by destabilizing the interacting residue R340 in the apo state of GS. Additionally, the mutation is predicted to result in a significant destabilization of helix H8, which should negatively affect glutamate binding. This prediction was tested in HEK293 cells overexpressing GS by dot-blot analysis: Structural stability of H8 was impaired through mutation of amino acids interacting with R341, as indicated by a loss of masking of an epitope in the glutamate binding pocket for a monoclonal anti-GS antibody by L-methionine-S-sulfoximine; in contrast, cells transfected with wild type GS showed the masking. Our analyses reveal complex molecular effects underlying impaired GS catalytic activity in three clinically relevant mutants. Our findings could stimulate the development of ATP binding-enhancing molecules by which the R324S mutant can be repaired extrinsically. Glutamine synthetase (GS) catalyzes the ATP-dependent ligation of ammonia and glutamate to glutamine, which makes the enzyme essential for human nitrogen metabolism. Three mutations in human GS, R324C, R324S, and R341C, had been identified previously that lead to a glutamine deficiency, resulting in neonatal death in the case of R324C and R341C. However, the molecular mechanisms underlying this impairment of GS activity have remained elusive. Our results from computational biophysics approaches suggest that all three mutants influence the first step of GS’ catalytic cycle, namely ATP or glutamate binding. The analyses reveal a complex set of effects including the loss of direct interactions to substrates, the involvement of water-mediated interactions that alleviate part of the mutation effect, and long-range effects between the catalytic site and structural parts distant from it. As to the latter, experimental validation is in line with our prediction of a significant destabilization of helix H8 in the R341C mutant, which should negatively affect glutamate binding. Finally, our findings could stimulate the development of ATP-binding enhancing molecules for the R324S mutant, which has been suggested to have residual activity, that way extrinsically “repairing” the mutant.
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Affiliation(s)
- Benedikt Frieg
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-University, Düsseldorf, Germany
| | - Boris Görg
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University, Düsseldorf, Germany
| | - Nadine Homeyer
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-University, Düsseldorf, Germany
| | - Verena Keitel
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University, Düsseldorf, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich-Heine-University, Düsseldorf, Germany
- * E-mail: (DH); (HG)
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-University, Düsseldorf, Germany
- * E-mail: (DH); (HG)
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Eid T, Gruenbaum SE, Dhaher R, Lee TSW, Zhou Y, Danbolt NC. The Glutamate-Glutamine Cycle in Epilepsy. ADVANCES IN NEUROBIOLOGY 2016; 13:351-400. [PMID: 27885637 DOI: 10.1007/978-3-319-45096-4_14] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Epilepsy is a complex, multifactorial disease characterized by spontaneous recurrent seizures and an increased incidence of comorbid conditions such as anxiety, depression, cognitive dysfunction, and sudden unexpected death. About 70 million people worldwide are estimated to suffer from epilepsy, and up to one-third of all people with epilepsy are expected to be refractory to current medications. Development of more effective and specific antiepileptic interventions is therefore requisite. Perturbations in the brain's glutamate-glutamine cycle, such as increased extracellular levels of glutamate, loss of astroglial glutamine synthetase, and changes in glutaminase and glutamate dehydrogenase, are frequently encountered in patients with epilepsy. Hence, manipulations of discrete glutamate-glutamine cycle components may represent novel approaches to treat the disease. The goal of his review is to discuss some of the glutamate-glutamine cycle components that are altered in epilepsy, particularly neurotransmitters and metabolites, enzymes, amino acid transporters, and glutamate receptors. We will also review approaches that potentially could be used in humans to target the glutamate-glutamine cycle. Examples of such approaches are treatment with glutamate receptor blockers, glutamate scavenging, dietary intervention, and hypothermia.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA.
| | - Shaun E Gruenbaum
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA
| | - Tih-Shih W Lee
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Yun Zhou
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Niels Christian Danbolt
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
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26
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Boycott KM, Beaulieu CL, Kernohan KD, Gebril OH, Mhanni A, Chudley AE, Redl D, Qin W, Hampson S, Küry S, Tetreault M, Puffenberger EG, Scott JN, Bezieau S, Reis A, Uebe S, Schumacher J, Hegele RA, McLeod DR, Gálvez-Peralta M, Majewski J, Ramaekers VT, Nebert DW, Innes AM, Parboosingh JS, Abou Jamra R. Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8. Am J Hum Genet 2015; 97:886-93. [PMID: 26637978 DOI: 10.1016/j.ajhg.2015.11.002] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/03/2015] [Indexed: 12/17/2022] Open
Abstract
Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development.
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Affiliation(s)
- Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada.
| | - Chandree L Beaulieu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Kristin D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Ola H Gebril
- National Research Centre, El Bohoth Street, Dokki, Giza 12622, Egypt
| | - Aziz Mhanni
- Section of Genetics and Metabolism, Children's Hospital and the Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB R3A 1S1, Canada
| | - Albert E Chudley
- Section of Genetics and Metabolism, Children's Hospital and the Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB R3A 1S1, Canada
| | - David Redl
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Wen Qin
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Sarah Hampson
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Sébastien Küry
- Department of Medical Genetics, CHU Nantes, Nantes 44093, France
| | - Martine Tetreault
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | | | - James N Scott
- Department of Radiology, Foothills Hospital, Calgary, AB T2N 2T9, Canada
| | - Stéphane Bezieau
- Department of Medical Genetics, CHU Nantes, Nantes 44093, France
| | - André Reis
- Institute of Human Genetics, FAU Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Steffen Uebe
- Institute of Human Genetics, FAU Erlangen-Nürnberg, Erlangen 91054, Germany
| | | | - Robert A Hegele
- Robarts Research Institute and University of Western Ontario, London, ON N6A 5B7, Canada
| | - D Ross McLeod
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Marina Gálvez-Peralta
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jacek Majewski
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Vincent T Ramaekers
- Department of Paediatric Neurology, Centre Hospitalier Universitaire, Liege 4032, Belgium
| | - Daniel W Nebert
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; Department of Pediatrics & Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
| | - A Micheil Innes
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada
| | | | - Rami Abou Jamra
- Institute of Human Genetics, FAU Erlangen-Nürnberg, Erlangen 91054, Germany.
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Hu L, Ibrahim K, Stucki M, Frapolli M, Shahbeck N, Chaudhry FA, Görg B, Häussinger D, Penberthy WT, Ben-Omran T, Häberle J. Secondary NAD+ deficiency in the inherited defect of glutamine synthetase. J Inherit Metab Dis 2015; 38:1075-83. [PMID: 25896882 DOI: 10.1007/s10545-015-9846-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/03/2015] [Accepted: 03/20/2015] [Indexed: 01/05/2023]
Abstract
Glutamine synthetase (GS) deficiency is an ultra-rare inborn error of amino acid metabolism that has been described in only three patients so far. The disease is characterized by neonatal onset of severe encephalopathy, low levels of glutamine in blood and cerebrospinal fluid, chronic moderate hyperammonemia, and an overall poor prognosis in the absence of an effective treatment. Recently, enteral glutamine supplementation was shown to be a safe and effective therapy for this disease but there are no data available on the long-term effects of this intervention. The amino acid glutamine, severely lacking in this disorder, is central to many metabolic pathways in the human organism and is involved in the synthesis of nicotinamide adenine dinucleotide (NAD(+)) starting from tryptophan or niacin as nicotinate, but not nicotinamide. Using fibroblasts, leukocytes, and immortalized peripheral blood stem cells (PBSC) from a patient carrying a GLUL gene point mutation associated with impaired GS activity, we tested whether glutamine deficiency in this patient results in NAD(+) depletion and whether it can be rescued by supplementation with glutamine, nicotinamide or nicotinate. The present study shows that congenital GS deficiency is associated with NAD(+) depletion in fibroblasts, leukocytes and PBSC, which may contribute to the severe clinical phenotype of the disease. Furthermore, it shows that NAD(+) depletion can be rescued by nicotinamide supplementation in fibroblasts and leukocytes, which may open up potential therapeutic options for the treatment of this disorder.
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Affiliation(s)
- Liyan Hu
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
- Center for Neuroscience Zurich, Zurich, Switzerland
| | - Khalid Ibrahim
- Section of Pediatric Neurology, Hamad Medical Corporation, Doha, Qatar
| | - Martin Stucki
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
| | - Michele Frapolli
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
| | - Noora Shahbeck
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Farrukh A Chaudhry
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Boris Görg
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Dieter Häussinger
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Düsseldorf, Germany
| | | | - Tawfeg Ben-Omran
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
- Department of Pediatrics, Weil-Cornell Medical College, New York, USA
- Department of Genetic Medicine, Weil-Cornell Medical College, Doha, Qatar
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland.
- Center for Neuroscience Zurich, Zurich, Switzerland.
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Ryu JM, Lee HJ, Jung YH, Lee KH, Kim DI, Kim JY, Ko SH, Choi GE, Chai II, Song EJ, Oh JY, Lee SJ, Han HJ. Regulation of Stem Cell Fate by ROS-mediated Alteration of Metabolism. Int J Stem Cells 2015; 8:24-35. [PMID: 26019752 PMCID: PMC4445707 DOI: 10.15283/ijsc.2015.8.1.24] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 04/14/2015] [Indexed: 02/06/2023] Open
Abstract
Stem cells have attracted much attention due to their distinct features that support infinite self-renewal and differentiation into the cellular derivatives of three lineages. Recent studies have suggested that many stem cells both embryonic and adult stem cells reside in a specialized niche defined by hypoxic condition. In this respect, distinguishing functional differences arising from the oxygen concentration is important in understanding the nature of stem cells and in controlling stem cell fate for therapeutic purposes. ROS act as cellular signaling molecules involved in the propagation of signaling and the translation of environmental cues into cellular responses to maintain cellular homeostasis, which is mediated by the coordination of various cellular processes, and to adapt cellular activity to available bioenergetic sources. Thus, in this review, we describe the physiological role of ROS in stem cell fate and its effect on the metabolic regulation of stem cells.
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Affiliation(s)
- Jung Min Ryu
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Hyun Jik Lee
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Ki Hoon Lee
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Dah Ihm Kim
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Jeong Yeon Kim
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - So Hee Ko
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Gee Euhn Choi
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Ing Ing Chai
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Eun Ju Song
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Ji Young Oh
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Sei-Jung Lee
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, and BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, Korea
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Crunelli V, Carmignoto G, Steinhäuser C. Novel astrocyte targets: new avenues for the therapeutic treatment of epilepsy. Neuroscientist 2015; 21:62-83. [PMID: 24609207 PMCID: PMC4361461 DOI: 10.1177/1073858414523320] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During the last 20 years, it has been well established that a finely tuned, continuous crosstalk between neurons and astrocytes not only critically modulates physiological brain functions but also underlies many neurological diseases. In particular, this novel way of interpreting brain activity is markedly influencing our current knowledge of epilepsy, prompting a re-evaluation of old findings and guiding novel experimentation. Here, we review recent studies that have unraveled novel and unique contributions of astrocytes to the generation and spread of convulsive and nonconvulsive seizures and epileptiform activity. The emerging scenario advocates an overall framework in which a dynamic and reciprocal interplay among astrocytic and neuronal ensembles is fundamental for a fuller understanding of epilepsy. In turn, this offers novel astrocytic targets for the development of those really novel chemical entities for the control of convulsive and nonconvulsive seizures that have been acknowledged as a key priority in the management of epilepsy.
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Affiliation(s)
- Vincenzo Crunelli
- Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, UK
| | - Giorgio Carmignoto
- Centro Nazionale della Ricerca, Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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30
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Pekny M, Pekna M. Astrocyte reactivity and reactive astrogliosis: costs and benefits. Physiol Rev 2014; 94:1077-98. [PMID: 25287860 DOI: 10.1152/physrev.00041.2013] [Citation(s) in RCA: 616] [Impact Index Per Article: 61.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant cells in the central nervous system (CNS) that provide nutrients, recycle neurotransmitters, as well as fulfill a wide range of other homeostasis maintaining functions. During the past two decades, astrocytes emerged also as increasingly important regulators of neuronal functions including the generation of new nerve cells and structural as well as functional synapse remodeling. Reactive gliosis or reactive astrogliosis is a term coined for the morphological and functional changes seen in astroglial cells/astrocytes responding to CNS injury and other neurological diseases. Whereas this defensive reaction of astrocytes is conceivably aimed at handling the acute stress, limiting tissue damage, and restoring homeostasis, it may also inhibit adaptive neural plasticity mechanisms underlying recovery of function. Understanding the multifaceted roles of astrocytes in the healthy and diseased CNS will undoubtedly contribute to the development of treatment strategies that will, in a context-dependent manner and at appropriate time points, modulate reactive astrogliosis to promote brain repair and reduce the neurological impairment.
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Affiliation(s)
- Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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31
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Abstract
The multifunctional properties of astrocytes signify their importance in brain physiology and neurological function. In addition to defining the brain architecture, astrocytes are primary elements of brain ion, pH and neurotransmitter homoeostasis. GS (glutamine synthetase), which catalyses the ATP-dependent condensation of ammonia and glutamate to form glutamine, is an enzyme particularly found in astrocytes. GS plays a pivotal role in glutamate and glutamine homoeostasis, orchestrating astrocyte glutamate uptake/release and the glutamate-glutamine cycle. Furthermore, astrocytes bear the brunt of clearing ammonia in the brain, preventing neurotoxicity. The present review depicts the central function of astrocytes, concentrating on the importance of GS in glutamate/glutamine metabolism and ammonia detoxification in health and disease.
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32
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Huyghe D, Nakamura Y, Terunuma M, Faideau M, Haydon P, Pangalos MN, Moss SJ. Glutamine synthetase stability and subcellular distribution in astrocytes are regulated by γ-aminobutyric type B receptors. J Biol Chem 2014; 289:28808-15. [PMID: 25172509 DOI: 10.1074/jbc.m114.583534] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Emerging evidence suggests that functional γ-aminobutyric acid B receptors (GABABRs) are expressed by astrocytes within the mammalian brain. GABABRs are heterodimeric G-protein-coupled receptors that are composed of R1/R2 subunits. To date, they have been characterized in neurons as the principal mediators of sustained inhibitory signaling; however their roles in astrocytic physiology have been ill defined. Here we reveal that the cytoplasmic tail of the GABABR2 subunit binds directly to the astrocytic protein glutamine synthetase (GS) and that this interaction determines the subcellular localization of GS. We further demonstrate that the binding of GS to GABABR2 increases the steady state expression levels of GS in heterologous cells and in mouse primary astrocyte culture. Mechanistically this increased stability of GS in the presence of GABABR2 occurs via reduced proteasomal degradation. Collectively, our results suggest a novel role for GABABRs as regulators of GS stability. Given the critical role that GS plays in the glutamine-glutamate cycle, astrocytic GABABRs may play a critical role in supporting both inhibitory and excitatory neurotransmission.
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Affiliation(s)
- Deborah Huyghe
- From the Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Yasuko Nakamura
- From the Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Miho Terunuma
- Department of Cell Physiology and Pharmacology, College of Medicine, Biological Sciences and Psychology, University of Leicester, University Road, Leicester LE1 9HN, United Kingdom
| | - Mathilde Faideau
- Department of Experimental Dementia Research, Lund University SE-221 00 Lund, Sweden
| | - Philip Haydon
- From the Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Menelas N Pangalos
- Innovative Medicines, AstraZeneca, Mereside, Alderley Park, Cheshire SK10 4TF, United Kingdom, and
| | - Stephen J Moss
- From the Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6B, United Kingdom
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Eid T, Tu N, Lee TSW, Lai JCK. Regulation of astrocyte glutamine synthetase in epilepsy. Neurochem Int 2013; 63:670-81. [PMID: 23791709 DOI: 10.1016/j.neuint.2013.06.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 05/28/2013] [Accepted: 06/08/2013] [Indexed: 11/20/2022]
Abstract
Astrocytes play a crucial role in regulating and maintaining the extracellular chemical milieu of the central nervous system under physiological conditions. Moreover, proliferation of phenotypically altered astrocytes (a.k.a. reactive astrogliosis) has been associated with many neurologic and psychiatric disorders, including mesial temporal lobe epilepsy (MTLE). Glutamine synthetase (GS), which is found in astrocytes, is the only enzyme known to date that is capable of converting glutamate and ammonia to glutamine in the mammalian brain. This reaction is important, because a continuous supply of glutamine is necessary for the synthesis of glutamate and GABA in neurons. The known stoichiometry of glutamate transport across the astrocyte plasma membrane also suggests that rapid metabolism of intracellular glutamate via GS is a prerequisite for efficient glutamate clearance from the extracellular space. Several studies have indicated that the activity of GS in astrocytes is diminished in several brain disorders, including MTLE. It has been hypothesized that the loss of GS activity in MTLE leads to increased extracellular glutamate concentrations and epileptic seizures. Understanding the mechanisms by which GS is regulated may lead to novel therapeutic approaches to MTLE, which is frequently refractory to antiepileptic drugs. This review discusses several known mechanisms by which GS expression and function are influenced, from transcriptional control to enzyme modification.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, United States.
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O'Sullivan A, He X, McNiven EMS, Haggarty NW, Lönnerdal B, Slupsky CM. Early diet impacts infant rhesus gut microbiome, immunity, and metabolism. J Proteome Res 2013; 12:2833-45. [PMID: 23651394 DOI: 10.1021/pr4001702] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Epidemiological research has indicated a relationship between infant formula feeding and increased risk of chronic diseases later in life including obesity, type-2 diabetes, and cardiovascular disease. The present study used an infant rhesus monkey model to compare the comprehensive metabolic implications of formula- and breast-feeding practices using NMR spectroscopy to characterize metabolite fingerprints from urine and serum, in combination with anthropometric measurements, fecal microbial profiling, and cytokine measurements. Here we show that formula-fed infants are larger than their breast-fed counterparts and have a different gut microbiome that includes higher levels of bacteria from the Ruminococcus genus and lower levels of bacteria from the Lactobacillus genus. In addition, formula-fed infants have higher serum insulin coupled with higher amino acid levels, while amino acid degradation products were higher in breast-fed infants. Increases in serum and urine galactose and urine galactitol were observed in the second month of life in formula-fed infants, along with higher levels of TNFα, IFN-γ, IL-1β, IL-4, and other cytokines and growth factors at week 4. These results demonstrate that metabolic and gut microbiome development of formula-fed infants is different from breast-fed infants and that the choice of infant feeding may hold future health consequences.
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Affiliation(s)
- Aifric O'Sullivan
- Department of Nutrition, One Shields Avenue, University of California, Davis, Davis, California 95616, United States
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Häberle J. Clinical and biochemical aspects of primary and secondary hyperammonemic disorders. Arch Biochem Biophys 2013; 536:101-8. [PMID: 23628343 DOI: 10.1016/j.abb.2013.04.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/16/2013] [Accepted: 04/17/2013] [Indexed: 02/08/2023]
Abstract
An increased concentration of ammonia is a non-specific laboratory sign indicating the presence of potentially toxic free ammonia that is not normally removed. This does occur in many different conditions for which hyperammonemia is a surrogate marker. Hyperammonemia can occur due to increased production or impaired detoxification of ammonia and should, if associated with clinical symptoms, be regarded as an emergency. The conditions can be classified into primary or secondary hyperammonemias depending on the underlying pathophysiology. If the urea cycle is directly affected by a defect of any of the involved enzymes or transporters, this results in primary hyperammonemia. If however the function of the urea cycle is inhibited by toxic metabolites or by substrate deficiencies, the situation is described as secondary hyperammonemia. For removal of ammonia, mammals require the action of glutamine synthetase in addition to the urea cycle, in order to ensure lowering of plasma ammonia concentrations to the normal range. Independent of its etiology, hyperammonemia may result in irreversible brain damage if not treated early and thoroughly. Thus, early recognition of a hyperammonemic state and immediate initiation of the specific management are of utmost importance. The main prognostic factors are, irrespective of the underlying cause, the duration of the hyperammonemic coma and the extent of ammonia accumulation. This paper will discuss the biochemical background of primary and secondary hyperammonemia and will give an overview of the various underlying conditions including a brief clinical outline and information on the genetic backgrounds.
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Affiliation(s)
- Johannes Häberle
- Division of Metabolism, University Children's Hospital Zurich, Steinwiesstr. 75, 8032 Zurich, Switzerland.
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36
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Eid T, Behar K, Dhaher R, Bumanglag AV, Lee TSW. Roles of glutamine synthetase inhibition in epilepsy. Neurochem Res 2012; 37:2339-50. [PMID: 22488332 PMCID: PMC3731630 DOI: 10.1007/s11064-012-0766-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 03/15/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
Glutamine synthetase (GS, E.C. 6.3.1.2) is a ubiquitous and highly compartmentalized enzyme that is critically involved in several metabolic pathways in the brain, including the glutamine-glutamate-GABA cycle and detoxification of ammonia. GS is normally localized to the cytoplasm of most astrocytes, with elevated concentrations of the enzyme being present in perivascular endfeet and in processes close to excitatory synapses. Interestingly, an increasing number of studies have indicated that the expression, distribution, or activity of brain GS is altered in several brain disorders, including Alzheimer's disease, schizophrenia, depression, suicidality, and mesial temporal lobe epilepsy (MTLE). Although the metabolic and functional sequelae of brain GS perturbations are not fully understood, it is likely that a deficiency in brain GS will have a significant biological impact due to the critical metabolic role of the enzyme. Furthermore, it is possible that restoration of GS in astrocytes lacking the enzyme could constitute a novel and highly specific therapy for these disorders. The goals of this review are to summarize key features of mammalian GS under normal conditions, and discuss the consequences of GS deficiency in brain disorders, specifically MTLE.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale University School of Medicine, 330 Cedar Street, P.O. Box 208035, New Haven, CT 06520-8035, USA.
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Brassier A, Ottolenghi C, Boddaert N, Sonigo P, Attié-Bitach T, Millischer-Bellaiche AE, Baujat G, Cormier-Daire V, Valayannopoulos V, Seta N, Piraud M, Chadefaux-Vekemans B, Vianey-Saban C, Froissart R, de Lonlay P. Maladies héréditaires du métabolisme : signes anténatals et diagnostic biologique. Arch Pediatr 2012; 19:959-69. [DOI: 10.1016/j.arcped.2012.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 06/27/2012] [Indexed: 10/26/2022]
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Zerebrale Bildgebung bei angeborenen Stoffwechselfehlern. Monatsschr Kinderheilkd 2012. [DOI: 10.1007/s00112-012-2686-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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39
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Häberle J, Shahbeck N, Ibrahim K, Schmitt B, Scheer I, O'Gorman R, Chaudhry FA, Ben-Omran T. Glutamine supplementation in a child with inherited GS deficiency improves the clinical status and partially corrects the peripheral and central amino acid imbalance. Orphanet J Rare Dis 2012; 7:48. [PMID: 22830360 PMCID: PMC3495849 DOI: 10.1186/1750-1172-7-48] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/06/2012] [Indexed: 11/10/2022] Open
Abstract
Glutamine synthetase (GS) is ubiquitously expressed in mammalian organisms and is a key enzyme in nitrogen metabolism. It is the only known enzyme capable of synthesising glutamine, an amino acid with many critical roles in the human organism. A defect in GLUL, encoding for GS, leads to congenital systemic glutamine deficiency and has been described in three patients with epileptic encephalopathy. There is no established treatment for this condition.Here, we describe a therapeutic trial consisting of enteral and parenteral glutamine supplementation in a four year old patient with GS deficiency. The patient received increasing doses of glutamine up to 1020 mg/kg/day. The effect of this glutamine supplementation was monitored clinically, biochemically, and by studies of the electroencephalogram (EEG) as well as by brain magnetic resonance imaging and spectroscopy.Treatment was well tolerated and clinical monitoring showed improved alertness. Concentrations of plasma glutamine normalized while levels in cerebrospinal fluid increased but remained below the lower reference range. The EEG showed clear improvement and spectroscopy revealed increasing concentrations of glutamine and glutamate in brain tissue. Concomitantly, there was no worsening of pre-existing chronic hyperammonemia.In conclusion, supplementation of glutamine is a safe therapeutic option for inherited GS deficiency since it corrects the peripheral biochemical phenotype and partially also improves the central biochemical phenotype. There was some clinical improvement but the patient had a long standing severe encephalopathy. Earlier supplementation with glutamine might have prevented some of the neuronal damage.
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Affiliation(s)
- Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
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40
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Perez EL, Lauritzen F, Wang Y, Lee TSW, Kang D, Zaveri HP, Chaudhry FA, Ottersen OP, Bergersen LH, Eid T. Evidence for astrocytes as a potential source of the glutamate excess in temporal lobe epilepsy. Neurobiol Dis 2012; 47:331-7. [PMID: 22659305 DOI: 10.1016/j.nbd.2012.05.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 05/07/2012] [Accepted: 05/24/2012] [Indexed: 12/26/2022] Open
Abstract
Increased extracellular brain glutamate has been implicated in the pathophysiology of human refractory temporal lobe epilepsy (TLE), but the cause of the excessive glutamate is unknown. Prior studies by us and others have shown that the glutamate degrading enzyme glutamine synthetase (GS) is deficient in astrocytes in the epileptogenic hippocampal formation in a subset of patients with TLE. We have postulated that the loss of GS in TLE leads to increased glutamate in astrocytes with elevated concentrations of extracellular glutamate and recurrent seizures as the ultimate end-points. Here we test the hypothesis that the deficiency in GS leads to increased glutamate in astrocytes. Rats were chronically infused with methionine sulfoximine (MSO, n=4) into the hippocampal formation to induce GS deficiency and recurrent seizures. A separate group of rats was infused with 0.9% NaCl (saline) as a control (n=6). At least 10days after the start of infusion, once recurrent seizures were established in the MSO-treated rats, the concentration of glutamate was assessed in CA1 of the hippocampal formation by immunogold electron microscopy. The concentration of glutamate was 47% higher in astrocytes in the MSO-treated vs. saline-treated rats (p=0.02), and the ratio of glutamate in astrocytes relative to axon terminals was increased by 74% in the MSO-treated rats (p=0.003). These data support our hypothesis that a deficiency in GS leads to increased glutamate in astrocytes. We additionally propose that the GS-deficient astrocytes in the hippocampal formation in TLE lead to elevated extracellular brain glutamate either through decreased clearance of extracellular glutamate or excessive release of glutamate into the extracellular space from these cells, or a combination of the two.
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Affiliation(s)
- Edgar L Perez
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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41
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Brown PM, Hutchison JD, Crockett JC. Absence of glutamine supplementation prevents differentiation of murine calvarial osteoblasts to a mineralizing phenotype. Calcif Tissue Int 2011; 89:472-82. [PMID: 21972050 DOI: 10.1007/s00223-011-9537-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 09/11/2011] [Indexed: 10/17/2022]
Abstract
Osteoblasts in vitro differentiate from a proliferating to a mineralizing phenotype upon transfer to a medium rich in beta-glycerophosphate and ascorbic acid. The nutritional requirements of the cells at different stages of this differentiation process are not known. In other cell types, nutritional supplementation during surgery can improve the outcome in terms of speed of patient recovery and prognosis. There is therefore the potential for supplementation at the site of fracture repair or bone grafting with critical osteoblast nutritional factors to potentially accelerate healing. In this study we investigate which common cell nutrients are required for the proliferating and mineralizing stages of osteoblast differentiation. Medium containing 5.5 mM glucose was sufficient to achieve maximal proliferation of primary calvarial osteoblasts and human osteoblast cell lines, with some added benefit of additional glutamine supplementation. However, when cells were stimulated to mineralize, glucose was insufficient to support their energetic requirements. Only when cells were supplemented with glucose together with glutamine were high levels of osteocalcin expression observed together with mineralized nodules in culture, suggesting that this would be a useful combination to assess in cultures of primary human osteoblasts to determine whether it may have beneficial effects during fracture surgery, bone grafting, and fixation of uncemented arthroplasty implants.
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Affiliation(s)
- Philip M Brown
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, UK
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42
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Papageorgiou IE, Gabriel S, Fetani AF, Kann O, Heinemann U. Redistribution of astrocytic glutamine synthetase in the hippocampus of chronic epileptic rats. Glia 2011; 59:1706-18. [DOI: 10.1002/glia.21217] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/16/2011] [Indexed: 01/01/2023]
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43
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Kalkman HO. Circumstantial evidence for a role of glutamine-synthetase in suicide. Med Hypotheses 2011; 76:905-7. [DOI: 10.1016/j.mehy.2011.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 12/10/2010] [Accepted: 03/03/2011] [Indexed: 12/19/2022]
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44
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Häberle J, Shahbeck N, Ibrahim K, Hoffmann GF, Ben-Omran T. Natural course of glutamine synthetase deficiency in a 3 year old patient. Mol Genet Metab 2011; 103:89-91. [PMID: 21353613 DOI: 10.1016/j.ymgme.2011.02.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 11/28/2022]
Abstract
Glutamine deficiency with hyperammonemia due to an inherited defect of glutamine synthetase (GS) was found in a 2 year old patient. He presented neonatal seizures and developed chronic encephalopathy. Thus, GS deficiency leads to severe neurological disease but is not always early lethal.
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Affiliation(s)
- Johannes Häberle
- University Children's Hospital Zurich, Division of Metabolism, 8032 Zürich, Switzerland.
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45
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Hernandez MA, Schulz R, Chaplin T, Young BD, Perrett D, Champion MP, Taanman JW, Fensom A, Marinaki AM. The diagnosis of inherited metabolic diseases by microarray gene expression profiling. Orphanet J Rare Dis 2010; 5:34. [PMID: 21122112 PMCID: PMC3009951 DOI: 10.1186/1750-1172-5-34] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 12/01/2010] [Indexed: 02/04/2023] Open
Abstract
Background Inherited metabolic diseases (IMDs) comprise a diverse group of generally progressive genetic metabolic disorders of variable clinical presentations and severity. We have undertaken a study using microarray gene expression profiling of cultured fibroblasts to investigate 68 patients with a broad range of suspected metabolic disorders, including defects of lysosomal, mitochondrial, peroxisomal, fatty acid, carbohydrate, amino acid, molybdenum cofactor, and purine and pyrimidine metabolism. We aimed to define gene expression signatures characteristic of defective metabolic pathways. Methods Total mRNA extracted from cultured fibroblast cell lines was hybridized to Affymetrix U133 Plus 2.0 arrays. Expression data was analyzed for the presence of a gene expression signature characteristic of an inherited metabolic disorder and for genes expressing significantly decreased levels of mRNA. Results No characteristic signatures were found. However, in 16% of cases, disease-associated nonsense and frameshift mutations generating premature termination codons resulted in significantly decreased mRNA expression of the defective gene. The microarray assay detected these changes with high sensitivity and specificity. Conclusion In patients with a suspected familial metabolic disorder where initial screening tests have proven uninformative, microarray gene expression profiling may contribute significantly to the identification of the genetic defect, shortcutting the diagnostic cascade.
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46
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Andriamihaja M, Davila AM, Eklou-Lawson M, Petit N, Delpal S, Allek F, Blais A, Delteil C, Tomé D, Blachier F. Colon luminal content and epithelial cell morphology are markedly modified in rats fed with a high-protein diet. Am J Physiol Gastrointest Liver Physiol 2010; 299:G1030-7. [PMID: 20689060 DOI: 10.1152/ajpgi.00149.2010] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hyperproteic diets are used in human nutrition to obtain body weight reduction. Although increased protein ingestion results in an increased transfer of proteins from the small to the large intestine, there is little information on the consequences of the use of such diets on the composition of large intestine content and on epithelial cell morphology and metabolism. Rats were fed for 15 days with either a normoproteic (NP, 14% protein) or a hyperproteic isocaloric diet (HP, 53% protein), and absorptive colonocytes were observed by electron microscopy or isolated for enzyme activity studies. The colonic luminal content was recovered for biochemical analysis. Absorbing colonocytes were characterized by a 1.7-fold reduction in the height of the brush-border membranes (P = 0.0001) after HP diet consumption when compared with NP. This coincided in the whole colon content of HP animals with a 1.8-fold higher mass content (P = 0.0020), a 2.2-fold higher water content (P = 0.0240), a 5.2-fold higher protease activity (P = 0.0104), a 5.5-fold higher ammonia content (P = 0.0008), and a more than twofold higher propionate, valerate, isobutyrate, and isovalerate content (P < 0.05). The basal oxygen consumption of colonocytes was similar in the NP and HP groups, but ammonia was found to provoke a dose-dependent decrease of oxygen consumption in the isolated absorbing colonocytes. The activity of glutamine synthetase (which condenses ammonia and glutamate) was found to be much higher in colonocytes than in small intestine enterocytes and was 1.6-fold higher (P = 0.0304) in colonocytes isolated from HP animals than NP. Glutaminase activity remained unchanged. Thus hyperproteic diet ingestion causes marked changes both in the luminal environment of colonocytes and in the characteristics of these cells, demonstrating that hyperproteic diet interferes with colonocyte metabolism and morphology. Possible causal relationships between energy metabolism, reduced height of colonocyte brush-border membranes, and reduced water absorption are discussed.
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Affiliation(s)
- Mireille Andriamihaja
- Institut National de Recherche Agronomique, AgroParisTech, Centre de Recherche en Nutrition Humaine-Ile de France, UMR 914 Physiologie de Nutrition et du Comportement Alimentaire, Paris, France
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47
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Yoshioka C, Yasuda S, Kimura F, Kobayashi M, Itagaki S, Hirano T, Iseki K. Expression and role of SNAT3 in the placenta. Placenta 2009; 30:1071-7. [PMID: 19892400 DOI: 10.1016/j.placenta.2009.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 09/22/2009] [Accepted: 09/23/2009] [Indexed: 11/26/2022]
Abstract
Glutamine is the most versatile amino acid and its plasma concentration is the highest of all amino acid. Many transporters are therefore involved in glutamine uptake or efflux. Glutamine is actively released from the placenta into fetal circulation. In this study, we examined the alteration of transporters that transport glutamine into fetal circulation as gestation progresses. High expression levels of system A and y(+)L were found in the rat placenta in the late period of pregnancy and the expression levels of these transporters increased as gestation progressed (p<0.05). On the other hand, the expression of SNAT3, the system N transporter, was detected in the early period of pregnancy and its expression level decreased as gestation progressed (p<0.05). SNAT3 was also found to be expressed in isolated human primary cytotrophoblast cells and its expression level was decreased by their differentiation into syncytiotrophoblast cells (p<0.05). Since this regulation is closely related to glutamine synthetase expression, SNAT3 may play a key role in providing glutamine corresponding to glutamine synthetase function in the early period of gestation. This is the first report on the expression of SNAT3 in the placenta in the early stage of pregnancy.
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Affiliation(s)
- C Yoshioka
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo, Japan
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48
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Danielyan L, Zellmer S, Sickinger S, Tolstonog GV, Salvetter J, Lourhmati A, Reissig DD, Gleiter CH, Gebhardt R, Buniatian GH. Keratinocytes as depository of ammonium-inducible glutamine synthetase: age- and anatomy-dependent distribution in human and rat skin. PLoS One 2009; 4:e4416. [PMID: 19204801 PMCID: PMC2637544 DOI: 10.1371/journal.pone.0004416] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 12/23/2008] [Indexed: 02/02/2023] Open
Abstract
In inner organs, glutamine contributes to proliferation, detoxification and establishment of a mechanical barrier, i.e., functions essential for skin, as well. However, the age-dependent and regional peculiarities of distribution of glutamine synthetase (GS), an enzyme responsible for generation of glutamine, and factors regulating its enzymatic activity in mammalian skin remain undisclosed. To explore this, GS localization was investigated using immunohistochemistry and double-labeling of young and adult human and rat skin sections as well as skin cells in culture. In human and rat skin GS was almost completely co-localized with astrocyte-specific proteins (e.g. GFAP). While GS staining was pronounced in all layers of the epidermis of young human skin, staining was reduced and more differentiated among different layers with age. In stratum basale and in stratum spinosum GS was co-localized with the adherens junction component beta-catenin. Inhibition of, glycogen synthase kinase 3beta in cultured keratinocytes and HaCaT cells, however, did not support a direct role of beta-catenin in regulation of GS. Enzymatic and reverse transcriptase polymerase chain reaction studies revealed an unusual mode of regulation of this enzyme in keratinocytes, i.e., GS activity, but not expression, was enhanced about 8-10 fold when the cells were exposed to ammonium ions. Prominent posttranscriptional up-regulation of GS activity in keratinocytes by ammonium ions in conjunction with widespread distribution of GS immunoreactivity throughout the epidermis allows considering the skin as a large reservoir of latent GS. Such a depository of glutamine-generating enzyme seems essential for continuous renewal of epidermal permeability barrier and during pathological processes accompanied by hyperammonemia.
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Affiliation(s)
- Lusine Danielyan
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | - Sebastian Zellmer
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Stefan Sickinger
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Genrich V. Tolstonog
- Heinrich-Pette-Institute for Experimental Virology and Immunology, Hamburg, Germany
| | | | - Ali Lourhmati
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | | | - Cristoph H. Gleiter
- Department of Clinical Pharmacology, University Hospital of Tübingen, Tübingen, Germany
| | - Rolf Gebhardt
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
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Chalcraft KR, Britz-McKibbin P. Newborn Screening of Inborn Errors of Metabolism by Capillary Electrophoresis−Electrospray Ionization-Mass Spectrometry: A Second-Tier Method with Improved Specificity and Sensitivity. Anal Chem 2008; 81:307-14. [PMID: 19117458 DOI: 10.1021/ac8020455] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kenneth R. Chalcraft
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Philip Britz-McKibbin
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
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50
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Abstract
Birth and adaptation to extrauterine life involve major shifts in the protein and energy metabolism of the human newborn. These include a shift from a state of continuous supply of nutrients including amino acids from the mother to cyclic periodic oral intake, a change in the redox state of organs, thermogenesis, and a significant change in the mobilization and use of oxidative substrates. The development of safe, stable isotopic tracer methods has allowed the study of protein and amino acid metabolism not only in the healthy newborn but also in those born prematurely and of low birth weight. These studies have identified the unique and quantitative aspects of amino acid/protein metabolism in the neonate, thus contributing to rational nutritional care of these babies. The present review summarizes the contemporary data on some of the significant developments in essential and dispensable amino acids and their relationship to overall protein metabolism. Specifically, the recent data of kinetics of leucine, phenylalanine, glutamine, sulfur amino acid, and threonine and their relation to whole-body protein turnover are presented. Finally, the physiological rationale and the impact of nutrient (amino acids) interventions on the dynamics of protein metabolism are discussed.
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Affiliation(s)
- Satish C Kalhan
- Department of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195, USA.
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