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Rasooli A, Adab HZ, Van Ruitenbeek P, Weerasekera A, Chalavi S, Cuypers K, Levin O, Dhollander T, Peeters R, Sunaert S, Mantini D, Swinnen SP. White matter and neurochemical mechanisms underlying age-related differences in motor processing speed. iScience 2023; 26:106794. [PMID: 37255665 PMCID: PMC10225899 DOI: 10.1016/j.isci.2023.106794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 01/11/2023] [Accepted: 04/27/2023] [Indexed: 06/01/2023] Open
Abstract
Aging is associated with changes in the central nervous system and leads to reduced life quality. Here, we investigated the age-related differences in the CNS underlying motor performance deficits using magnetic resonance spectroscopy and diffusion MRI. MRS measured N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) concentrations in the sensorimotor and occipital cortex, whereas dMRI quantified apparent fiber density (FD) in the same voxels to evaluate white matter microstructural organization. We found that aging was associated with increased reaction time and reduced FD and NAA concentration in the sensorimotor voxel. Both FD and NAA mediated the association between age and reaction time. The NAA concentration was found to mediate the association between age and FD in the sensorimotor voxel. We propose that the age-related decrease in NAA concentration may result in reduced axonal fiber density in the sensorimotor cortex which may ultimately account for the response slowness of older participants.
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Affiliation(s)
- Amirhossein Rasooli
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Hamed Zivari Adab
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Peter Van Ruitenbeek
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD Maastricht, the Netherlands
| | - Akila Weerasekera
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sima Chalavi
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Koen Cuypers
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
- REVAL Rehabilitation Research Center, Hasselt University, Diepenbeek, Belgium
| | - Oron Levin
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Thijs Dhollander
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Ronald Peeters
- KU Leuven, Department of Imaging and Pathology, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Stefan Sunaert
- KU Leuven, Department of Imaging and Pathology, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Dante Mantini
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Stephan P. Swinnen
- Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
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Mosso J, Yin T, Poitry-Yamate C, Simicic D, Lepore M, McLin VA, Braissant O, Cudalbu C, Lanz B. PET CMR glc mapping and 1H-MRS show altered glucose uptake and neurometabolic profiles in BDL rats. Anal Biochem 2022; 647:114606. [PMID: 35240109 DOI: 10.1016/j.ab.2022.114606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/06/2022] [Accepted: 02/13/2022] [Indexed: 12/14/2022]
Abstract
Type C hepatic encephalopathy (HE) is a complex neuropsychiatric disorder occurring as a consequence of chronic liver disease. Alterations in energy metabolism have been suggested in type C HE, but in vivo studies on this matter remain sparse and have reported conflicting results. Here, we propose a novel preclinical 18F-FDG PET methodology to compute quantitative 3D maps of the regional cerebral metabolic rate of glucose (CMRglc) from a labelling steady-state PET image of the brain and an image-derived input function. This quantitative approach shows its strength when comparing groups of animals with divergent physiology, such as HE animals. PET CMRglc maps were registered to an atlas and the mean CMRglc from the hippocampus and the cerebellum were associated to the corresponding localized 1H-MR spectroscopy acquisitions. This study provides for the first time local and quantitative information on both brain glucose uptake and neurometabolic profile alterations in a rat model of type C HE. A 2-fold lower brain glucose uptake, concomitant with an increase in brain glutamine and a decrease in the main osmolytes was observed in the hippocampus and in the cerebellum. These novel findings are an important step towards new insights into energy metabolism in the pathophysiology of HE.
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Affiliation(s)
- Jessie Mosso
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland; Laboratory for Functional and Metabolic Imaging (LIFMET), EPFL, Lausanne, Switzerland
| | - Ting Yin
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland
| | | | - Dunja Simicic
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland; Laboratory for Functional and Metabolic Imaging (LIFMET), EPFL, Lausanne, Switzerland
| | - Mario Lepore
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland
| | - Valérie A McLin
- Swiss Pediatric Liver Center, Department of Pediatrics, Gynecology and Obstetrics, University Hospitals Geneva, And University of Geneva, Geneva, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Cristina Cudalbu
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland
| | - Bernard Lanz
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology (AIT), EPFL, Lausanne, Switzerland; Laboratory for Functional and Metabolic Imaging (LIFMET), EPFL, Lausanne, Switzerland.
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Fernandes-Pires G, Braissant O. Current and potential new treatment strategies for creatine deficiency syndromes. Mol Genet Metab 2022; 135:15-26. [PMID: 34972654 DOI: 10.1016/j.ymgme.2021.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 12/16/2022]
Abstract
Creatine deficiency syndromes (CDS) are inherited metabolic disorders caused by mutations in GATM, GAMT and SLC6A8 and mainly affect central nervous system (CNS). AGAT- and GAMT-deficient patients lack the functional brain endogenous creatine (Cr) synthesis pathway but express the Cr transporter SLC6A8 at blood-brain barrier (BBB), and can thus be treated by oral supplementation of high doses of Cr. For Cr transporter deficiency (SLC6A8 deficiency or CTD), current treatment strategies benefit one-third of patients. However, as their phenotype is not completely reversed, and for the other two-thirds of CTD patients, the development of novel more effective therapies is needed. This article aims to review the current knowledge on Cr metabolism and CDS clinical aspects, highlighting their current treatment possibilities and the most recent research perspectives on CDS potential therapeutics designed, in particular, to bring new options for the treatment of CTD.
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Affiliation(s)
- Gabriella Fernandes-Pires
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland.
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Hellas JA, Andrew RD. Neuronal Swelling: A Non-osmotic Consequence of Spreading Depolarization. Neurocrit Care 2021; 35:112-134. [PMID: 34498208 PMCID: PMC8536653 DOI: 10.1007/s12028-021-01326-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 08/04/2021] [Indexed: 01/22/2023]
Abstract
An acute reduction in plasma osmolality causes rapid uptake of water by astrocytes but not by neurons, whereas both cell types swell as a consequence of lost blood flow (ischemia). Either hypoosmolality or ischemia can displace the brain downwards, potentially causing death. However, these disorders are fundamentally different at the cellular level. Astrocytes osmotically swell or shrink because they express functional water channels (aquaporins), whereas neurons lack functional aquaporins and thus maintain their volume. Yet both neurons and astrocytes immediately swell when blood flow to the brain is compromised (cytotoxic edema) as following stroke onset, sudden cardiac arrest, or traumatic brain injury. In each situation, neuronal swelling is the direct result of spreading depolarization (SD) generated when the ATP-dependent sodium/potassium ATPase (the Na+/K+ pump) is compromised. The simple, and incorrect, textbook explanation for neuronal swelling is that increased Na+ influx passively draws Cl- into the cell, with water following by osmosis via some unknown conduit. We first review the strong evidence that mammalian neurons resist volume change during acute osmotic stress. We then contrast this with their dramatic swelling during ischemia. Counter-intuitively, recent research argues that ischemic swelling of neurons is non-osmotic, involving ion/water cotransporters as well as at least one known amino acid water pump. While incompletely understood, these mechanisms argue against the dogma that neuronal swelling involves water uptake driven by an osmotic gradient with aquaporins as the conduit. Promoting clinical recovery from neuronal cytotoxic edema evoked by spreading depolarizations requires a far better understanding of molecular water pumps and ion/water cotransporters that act to rebalance water shifts during brain ischemia.
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Affiliation(s)
- Julia A Hellas
- Center for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada.
| | - R David Andrew
- Center for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
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Ghirardini E, Calugi F, Sagona G, Di Vetta F, Palma M, Battini R, Cioni G, Pizzorusso T, Baroncelli L. The Role of Preclinical Models in Creatine Transporter Deficiency: Neurobiological Mechanisms, Biomarkers and Therapeutic Development. Genes (Basel) 2021; 12:genes12081123. [PMID: 34440297 PMCID: PMC8392480 DOI: 10.3390/genes12081123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Creatine (Cr) Transporter Deficiency (CTD) is an X-linked metabolic disorder, mostly caused by missense mutations in the SLC6A8 gene and presenting with intellectual disability, autistic behavior, and epilepsy. There is no effective treatment for CTD and patients need lifelong assistance. Thus, the research of novel intervention strategies is a major scientific challenge. Animal models are an excellent tool to dissect the disease pathogenetic mechanisms and drive the preclinical development of therapeutics. This review illustrates the current knowledge about Cr metabolism and CTD clinical aspects, with a focus on mainstay diagnostic and therapeutic options. Then, we discuss the rodent models of CTD characterized in the last decade, comparing the phenotypes expressed within clinically relevant domains and the timeline of symptom development. This analysis highlights that animals with the ubiquitous deletion/mutation of SLC6A8 genes well recapitulate the early onset and the complex pathological phenotype of the human condition. Thus, they should represent the preferred model for preclinical efficacy studies. On the other hand, brain- and cell-specific conditional mutants are ideal for understanding the basis of CTD at a cellular and molecular level. Finally, we explain how CTD models might provide novel insight about the pathogenesis of other disorders, including cancer.
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MESH Headings
- Animals
- Biomarkers/metabolism
- Brain Diseases, Metabolic, Inborn/metabolism
- Brain Diseases, Metabolic, Inborn/pathology
- Brain Diseases, Metabolic, Inborn/therapy
- Central Nervous System/pathology
- Creatine/deficiency
- Creatine/metabolism
- Disease Models, Animal
- Humans
- Mental Retardation, X-Linked/metabolism
- Mental Retardation, X-Linked/pathology
- Mental Retardation, X-Linked/therapy
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/metabolism
- Rats
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Affiliation(s)
- Elsa Ghirardini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
| | - Francesco Calugi
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Giulia Sagona
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Federica Di Vetta
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Biology, University of Pisa, I-56126 Pisa, Italy
| | - Martina Palma
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Laura Baroncelli
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Correspondence:
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Carli S, Chaabane L, Butti C, De Palma C, Aimar P, Salio C, Vignoli A, Giustetto M, Landsberger N, Frasca A. In vivo magnetic resonance spectroscopy in the brain of Cdkl5 null mice reveals a metabolic profile indicative of mitochondrial dysfunctions. J Neurochem 2021; 157:1253-1269. [PMID: 33448385 DOI: 10.1111/jnc.15300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/24/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022]
Abstract
Mutations in the X-linked CDKL5 gene cause CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition mainly characterized by infantile epileptic encephalopathy, intellectual disability, and autistic features. The molecular mechanisms underlying the clinical symptoms remain largely unknown and the identification of reliable biomarkers in animal models will certainly contribute to increase our comprehension of CDD as well as to assess the efficacy of therapeutic strategies. Here, we used different Magnetic Resonance (MR) methods to disclose structural, functional, or metabolic signatures of Cdkl5 deficiency in the brain of adult mice. We found that loss of Cdkl5 does not cause cerebral atrophy but affects distinct brain areas, particularly the hippocampus. By in vivo proton-MR spectroscopy (MRS), we revealed in the Cdkl5 null brain a metabolic dysregulation indicative of mitochondrial dysfunctions. Accordingly, we unveiled a significant reduction in ATP levels and a decrease in the expression of complex IV of mitochondrial electron transport chain. Conversely, the number of mitochondria appeared preserved. Importantly, we reported a significant defect in the activation of one of the major regulators of cellular energy balance, the adenosine monophosphate-activated protein kinase (AMPK), that might contribute to the observed metabolic impairment and become an interesting therapeutic target for future preclinical trials. In conclusion, MRS revealed in the Cdkl5 null brain the presence of a metabolic dysregulation suggestive of a mitochondrial dysfunction that permitted to foster our comprehension of Cdkl5 deficiency and brought our interest towards targeting mitochondria as therapeutic strategy for CDD.
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Affiliation(s)
- Sara Carli
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Linda Chaabane
- Institute of Experimental Neurology (INSPE) and Experimental Imaging Center (CIS), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Clarissa Butti
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Molecular Nociception Group, Wolfson Institute for Biomedical Research (WIBR), University College London, London, UK
| | - Clara De Palma
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Patrizia Aimar
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Aglaia Vignoli
- Epilepsy Center-Child Neuropsychiatric Unit, ASST Santi Paolo e Carlo, Department of Health Sciences, University of Milan, Milan, Italy
| | - Maurizio Giustetto
- Department of Neuroscience, University of Turin, Turin, Italy.,National Institute of Neuroscience-Italy, Turin, Italy
| | - Nicoletta Landsberger
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Angelisa Frasca
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
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Okada Y, Sabirov RZ, Sato-Numata K, Numata T. Cell Death Induction and Protection by Activation of Ubiquitously Expressed Anion/Cation Channels. Part 1: Roles of VSOR/VRAC in Cell Volume Regulation, Release of Double-Edged Signals and Apoptotic/Necrotic Cell Death. Front Cell Dev Biol 2021; 8:614040. [PMID: 33511120 PMCID: PMC7835517 DOI: 10.3389/fcell.2020.614040] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/15/2020] [Indexed: 12/18/2022] Open
Abstract
Cell volume regulation (CVR) is essential for survival and functions of animal cells. Actually, normotonic cell shrinkage and swelling are coupled to apoptotic and necrotic cell death and thus called the apoptotic volume decrease (AVD) and the necrotic volume increase (NVI), respectively. A number of ubiquitously expressed anion and cation channels are involved not only in CVD but also in cell death induction. This series of review articles address the question how cell death is induced or protected with using ubiquitously expressed ion channels such as swelling-activated anion channels, acid-activated anion channels and several types of TRP cation channels including TRPM2 and TRPM7. The Part 1 focuses on the roles of the volume-sensitive outwardly rectifying anion channels (VSOR), also called the volume-regulated anion channel (VRAC), which is activated by cell swelling or reactive oxygen species (ROS) in a manner dependent on intracellular ATP. First we describe phenotypical properties, the molecular identity, and physical pore dimensions of VSOR/VRAC. Second, we highlight the roles of VSOR/VRAC in the release of organic signaling molecules, such as glutamate, glutathione, ATP and cGAMP, that play roles as double-edged swords in cell survival. Third, we discuss how VSOR/VRAC is involved in CVR and cell volume dysregulation as well as in the induction of or protection from apoptosis, necrosis and regulated necrosis under pathophysiological conditions.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ravshan Z. Sabirov
- Laboratory of Molecular Physiology, Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Kaori Sato-Numata
- Japan Society for the Promotion of Science, Tokyo, Japan
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan
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Braissant O, Rackayová V, Pierzchala K, Grosse J, McLin VA, Cudalbu C. Longitudinal neurometabolic changes in the hippocampus of a rat model of chronic hepatic encephalopathy. J Hepatol 2019; 71:505-515. [PMID: 31173812 DOI: 10.1016/j.jhep.2019.05.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 05/24/2019] [Accepted: 05/27/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS The sequence of events in hepatic encephalopathy (HE) remains unclear. Using the advantages of in vivo 1H-MRS (9.4T) we aimed to analyse the time-course of disease in an established model of type C HE by analysing the longitudinal changes in a large number of brain metabolites together with biochemical, histological and behavioural assessment. We hypothesized that neurometabolic changes are detectable very early, and that these early changes will offer insight into the primary events underpinning HE. METHODS Wistar rats underwent bile-duct ligation (BDL) and were studied before BDL and at post-operative weeks 2, 4, 6 and 8 (n = 26). In vivo short echo-time 1H-MRS (9.4T) of the hippocampus was performed in a longitudinal manner, as were biochemical (plasma), histological and behavioural tests. RESULTS Plasma ammonium increased early after BDL and remained high during the study. Brain glutamine increased (+47%) as early as 2-4 weeks post-BDL while creatine (-8%) and ascorbate (-12%) decreased. Brain glutamine and ascorbate correlated closely with rising plasma ammonium, while brain creatine correlated with brain glutamine. The increases in brain glutamine and plasma ammonium were correlated, while plasma ammonium correlated negatively with distance moved. Changes in astrocyte morphology were observed at 4 weeks. These early changes were further accentuated at 6-8 weeks post-BDL, concurrently with the known decreases in brain organic osmolytes. CONCLUSION Using a multimodal, in vivo and longitudinal approach we have shown that neurometabolic changes are already noticeable 2 weeks after BDL. These early changes are suggestive of osmotic/oxidative stress and are likely the premise of some later changes. Early decreases in cerebral creatine and ascorbate are novel findings offering new avenues to explore neuroprotective strategies for HE treatment. LAY SUMMARY The sequence of events in chronic hepatic encephalopathy (HE) remains unclear, therefore using the advantages of in vivo proton magnetic resonance spectroscopy at 9.4T we aimed to test the hypothesis that neurometabolic changes are detectable very early in an established model of type C HE, offering insight into the primary events underpinning HE, before advanced liver disease confounds the findings. These early, previously unreported neurometabolic changes occurred as early as 2 to 4 weeks after bile-duct ligation, namely an increase in plasma ammonium and brain glutamine, a decrease in brain creatine and ascorbate together with behavioural and astrocyte morphology changes, and continued to progress throughout the 8-week course of the disease.
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Affiliation(s)
- Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
| | - Veronika Rackayová
- Laboratory of Functional and Metabolic Imaging, Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Katarzyna Pierzchala
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Jocelyn Grosse
- Laboratory of Behavioral Genetics, Brain Mind Institute, School Of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Valérie A McLin
- Swiss Pediatric Liver Center, Department of Pediatrics, Gynecology and Obstetrics, University Hospitals Geneva, and University of Geneva Medical School, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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9
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Cassol G, Godinho DB, de Zorzi VN, Farinha JB, Della-Pace ID, de Carvalho Gonçalves M, Oliveira MS, Furian AF, Fighera MR, Royes LFF. Potential therapeutic implications of ergogenic compounds on pathophysiology induced by traumatic brain injury: A narrative review. Life Sci 2019; 233:116684. [DOI: 10.1016/j.lfs.2019.116684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/22/2019] [Indexed: 12/19/2022]
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10
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Lizarbe B, Soares AF, Larsson S, Duarte JMN. Neurochemical Modifications in the Hippocampus, Cortex and Hypothalamus of Mice Exposed to Long-Term High-Fat Diet. Front Neurosci 2019; 12:985. [PMID: 30670942 PMCID: PMC6331468 DOI: 10.3389/fnins.2018.00985] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/10/2018] [Indexed: 11/13/2022] Open
Abstract
Metabolic syndrome and diabetes impact brain function and metabolism. While it is well established that rodents exposed to diets rich in saturated fat develop brain dysfunction, contrasting results abound in the literature, likely as result of exposure to different high-fat diet (HFD) compositions and for varied periods of time. In the present study, we investigated alterations of hippocampal-dependent spatial memory by measuring Y-maze spontaneous alternation, metabolic profiles of the hippocampus, cortex and hypothalamus by 1H magnetic resonance spectroscopy (MRS), and levels of proteins specific to synaptic and glial compartments in mice exposed for 6 months to different amounts of fat (10, 45, or 60% of total energy intake). Increasing the dietary amount of fat from 10 to 45% or 60% resulted in obesity accompanied by increased leptin, fasting blood glucose and insulin, and reduced glucose tolerance. In comparison to controls (10%-fat), only mice fed the 60%-fat diet showed increased fed glycemia, as well as plasma corticosterone that has a major impact on brain function. HFD-induced metabolic profile modifications measured by 1H MRS were observed across the three brain areas in mice exposed to 60%- but not 45%-fat diet, while both HFD groups displayed impaired hippocampal-dependent memory. HFD also affected systems involved in neuro- or gliotransmission in the hippocampus. Namely, relative to controls, 60%-fat-fed mice showed reduced SNAP-25, PSD-95 and syntaxin-4 immunoreactivity, while 45%-fat-fed mice showed reduced gephyrin and syntaxin-4 immunoreactivity. For both HFD levels, reductions of the vesicular glutamate transporter vGlut1 and levels of the vesicular GABA transporter were observed in the hippocampus and hypothalamus, relative to controls. Immunoreactivity against GFAP and/or Iba-1 in the hypothalamus was higher in mice exposed to HFD than controls, suggesting occurrence of gliosis. We conclude that different levels of dietary fat result in distinct neurochemical alterations in the brain.
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Affiliation(s)
- Blanca Lizarbe
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Instituto de Investigaciones Biomédicas "Alberto Sols", Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Madrid, Spain
| | - Ana Francisca Soares
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sara Larsson
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - João M N Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Lund, Sweden
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11
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Rijpma A, van der Graaf M, Meulenbroek O, Olde Rikkert MGM, Heerschap A. Altered brain high-energy phosphate metabolism in mild Alzheimer's disease: A 3-dimensional 31P MR spectroscopic imaging study. NEUROIMAGE-CLINICAL 2018; 18:254-261. [PMID: 29876246 PMCID: PMC5987799 DOI: 10.1016/j.nicl.2018.01.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 12/15/2017] [Accepted: 01/24/2018] [Indexed: 12/20/2022]
Abstract
In Alzheimer's disease (AD), defects in essential metabolic processes for energy supply and phospholipid membrane function have been implicated in the pathological process. However, post-mortem investigations are generally limited to late stage disease and prone to tissue decay artifacts. In vivo assessments of high energy phosphates, tissue pH and phospholipid metabolites are possible by phosphorus MR spectroscopy (31P–MRS), but so far only small studies, mostly focusing on single brain regions, have been performed. Therefore, we assessed phospholipid and energy metabolism in multiple brain regions of 31 early stage AD patients and 31 age- and gender-matched controls using 31P–MRS imaging. An increase of phosphocreatine (PCr) was found in AD patients compared with controls in the retrosplenial cortex, and both hippocampi, but not in the anterior cingulate cortex. While PCr/inorganic phosphate and pH were also increased in AD, no changes were found for phospholipid metabolites. This study showed that PCr levels are specifically increased in regions that show early degeneration in AD. Together with an increased pH, this indicates an altered energy metabolism in mild AD. Phosphocreatine and pH are increased in mild Alzheimer's disease. Phosphocreatine increase occurs in early affected brain regions. Brain energy metabolism may be altered in mild Alzheimer's disease. Phospholipid and energy metabolites as well as pH, differ across brain regions.
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Key Words
- 1H, proton
- 31P–MRS, phosphorus magnetic resonance spectroscopy
- AC, anterior commissure
- ACC, anterior cingulate cortex
- AD, Alzheimer's disease
- ADP, adenosine diphosphate
- ATP, adenosine triphosphate
- Alzheimer's disease
- CK, creatine kinase
- CSF, cerebrospinal fluid
- Cr, creatine
- Dementia
- Energy metabolism
- GM, grey matter
- GPCh, glycerophosphocholine
- GPEth, glycerophosphoethanolamine
- HL, left hippocampus
- HR, right hippocampus
- LS, least square
- MCI, mild cognitive impairment
- MMSE, Mini Mental State Examination
- MRSI, magnetic resonance spectroscopic imaging
- NAD(H), nicotinamide adenine dinucleotide
- OXPHOS, oxidative phosphorylation
- PC, posterior commissure
- PCh, phosphocholine
- PCr, phosphocreatine
- PDE, phosphodiesters
- PEth, phosphoethanolamine
- PME, phosphomonoesters
- Phospholipid metabolism
- Phosphorus magnetic resonance spectroscopic imaging
- Pi, inorganic phosphate
- ROI, region of interest
- RSC, retrosplenial cortex
- WM, white matter
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Affiliation(s)
- Anne Rijpma
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands.
| | - Marinette van der Graaf
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands; Department of Paediatrics, Radboud university medical center, Nijmegen, The Netherlands
| | - Olga Meulenbroek
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Marcel G M Olde Rikkert
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
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12
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Cysique LA, Jugé L, Gates T, Tobia M, Moffat K, Brew BJ, Rae C. Covertly active and progressing neurochemical abnormalities in suppressed HIV infection. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2018; 5:e430. [PMID: 29312999 PMCID: PMC5754644 DOI: 10.1212/nxi.0000000000000430] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/10/2017] [Indexed: 11/15/2022]
Abstract
Objective To assess whether HIV-related brain injury is progressive in persons with suppressed HIV infection. Methods Seventy-three HIV+ virally suppressed men and 35 HIV- men, screened for psychiatric and alcohol/drug use disorders, underwent neuropsychological evaluation and proton magnetic resonance spectroscopy (1H-MRS) at baseline and after and 23 ± 5 months. 1H-MRS included brain regions known to be vulnerable to HIV and aging: frontal white matter (FWM), posterior cingulate cortex (PCC), and caudate area (CA). Major brain metabolites such as creatine (Cr: marker of cellular energy), N-acetyl aspartate (NAA: marker of neuronal integrity), choline (marker of cellular membrane turnover), glutamate/glutamine (excitatory/inhibitory neurotransmitter), and myo-Inositol (mI: marker of neuroinflammation) were calculated with reference to water signal. Neurocognitive decline was corrected for practice effect and baseline HIV-associated neurocognitive disorder (HAND) status. Results Across the study period, 44% had intact cognition, 42% stable HAND (including the single case that improved), 10% progressing HAND, and 4% incident HAND. When analyzing the neurochemical data per neurocognitive trajectories, we found decreasing PCC Cr in all subgroups compared with controls (p < 0.002). In addition, relative to the HIV- group, stable HAND showed decreasing FWM Cr, incident HAND showed steep FWM Cr reduction, whereas progressing HAND had a sharply decreasing PCC NAA and reduced but stable CA NAA. When analyzing the neurochemical data at the group level (HIV+ vs HIV- groups), we found stable abnormal metabolite concentrations over the study period: decreased FWM and PCC Cr (both p < 0.001), decreased PCC NAA and CA NAA (both p < 0.05) and PCC mI increase (p < 0.05). HIV duration and historical HAND had modest effects on metabolite changes. Conclusions Our study reveals covertly active or progressing HIV-related brain injury in the majority of this virally suppressed cohort, reflecting ongoing neuropathogenic processes that are only partially worsened by historical HAND and HIV duration. Longer-term studies will be important for determining the prognosis of these slowly evolving neurochemical abnormalities.
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Affiliation(s)
- Lucette A Cysique
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Lauriane Jugé
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Thomas Gates
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Michael Tobia
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Kirsten Moffat
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Bruce J Brew
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
| | - Caroline Rae
- School of Medical Sciences (L.A.C., L.J., M.T., C.R.), Faculty of Medicine, UNSW Australia, Sydney; Neuroscience Research Australia (L.A.C., L.J., C.R.), Randwick; Peter Duncan Neuroscience Research Unit (L.A.C., T.G., B.J.B.), St. Vincent's Applied Medical Research Center, Darlinghurst; and St. Vincent's Hospital Sydney (L.A.C., T.G., K.M., B.J.B.), Darlinghurst, New South Wales, Australia
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13
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Uncoupling N-acetylaspartate from brain pathology: implications for Canavan disease gene therapy. Acta Neuropathol 2018; 135:95-113. [PMID: 29116375 PMCID: PMC5756261 DOI: 10.1007/s00401-017-1784-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 11/25/2022]
Abstract
N-Acetylaspartate (NAA) is the second most abundant organic metabolite in the brain, but its physiological significance remains enigmatic. Toxic NAA accumulation appears to be the key factor for neurological decline in Canavan disease—a fatal neurometabolic disorder caused by deficiency in the NAA-degrading enzyme aspartoacylase. To date clinical outcome of gene replacement therapy for this spongiform leukodystrophy has not met expectations. To identify the target tissue and cells for maximum anticipated treatment benefit, we employed comprehensive phenotyping of novel mouse models to assess cell type-specific consequences of NAA depletion or elevation. We show that NAA-deficiency causes neurological deficits affecting unconscious defensive reactions aimed at protecting the body from external threat. This finding suggests, while NAA reduction is pivotal to treat Canavan disease, abrogating NAA synthesis should be avoided. At the other end of the spectrum, while predicting pathological severity in Canavan disease mice, increased brain NAA levels are not neurotoxic per se. In fact, in transgenic mice overexpressing the NAA synthesising enzyme Nat8l in neurons, supra-physiological NAA levels were uncoupled from neurological deficits. In contrast, elimination of aspartoacylase expression exclusively in oligodendrocytes elicited Canavan disease like pathology. Although conditional aspartoacylase deletion in oligodendrocytes abolished expression in the entire CNS, the remaining aspartoacylase in peripheral organs was sufficient to lower NAA levels, delay disease onset and ameliorate histopathology. However, comparable endpoints of the conditional and complete aspartoacylase knockout indicate that optimal Canavan disease gene replacement therapies should restore aspartoacylase expression in oligodendrocytes. On the basis of these findings we executed an ASPA gene replacement therapy targeting oligodendrocytes in Canavan disease mice resulting in reversal of pre-existing CNS pathology and lasting neurological benefits. This finding signifies the first successful post-symptomatic treatment of a white matter disorder using an adeno-associated virus vector tailored towards oligodendroglial-restricted transgene expression.
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14
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Singh K, Trivedi R, Haridas S, Manda K, Khushu S. Study of neurometabolic and behavioral alterations in rodent model of mild traumatic brain injury: a pilot study. NMR IN BIOMEDICINE 2016; 29:1748-1758. [PMID: 27779341 DOI: 10.1002/nbm.3627] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 08/05/2016] [Accepted: 08/23/2016] [Indexed: 06/06/2023]
Abstract
Mild traumatic brain injury (mTBI) is the most common form of TBI (70-90%) with consequences of anxiety-like behavioral alterations in approximately 23% of mTBI cases. This study aimed to assess whether mTBI-induced anxiety-like behavior is a consequence of neurometabolic alterations. mTBI was induced using a weight drop model to simulate mild human brain injury in rodents. Based on injury induction and dosage of anesthesia, four animal groups were included in this study: (i) injury with anesthesia (IA); (ii) sham1 (injury only, IO); (iii) sham2 (only anesthesia, OA); and (iv) control rats. After mTBI, proton magnetic resonance spectroscopy (1 H-MRS) and neurobehavioral analysis were performed in these groups. At day 5, reduced taurine (Tau)/total creatine (tCr, creatine and phosphocreatine) levels in cortex were observed in the IA and IO groups relative to the control. These groups showed mTBI-induced anxiety-like behavior with normal cognition at day 5 post-injury. An anxiogenic effect of repeated dosage of anesthesia in OA rats was observed with normal Tau/tCr levels in rat cortex, which requires further examination. In conclusion, this mTBI model closely mimics human concussion injury with anxiety-like behavior and normal cognition. Reduced cortical Tau levels may provide a putative neurometabolic basis of anxiety-like behavior following mTBI.
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Affiliation(s)
- Kavita Singh
- NMR Research Center, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Richa Trivedi
- NMR Research Center, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Seenu Haridas
- Neurobehavior Laboratory, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Kailash Manda
- Neurobehavior Laboratory, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Subash Khushu
- NMR Research Center, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
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15
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Rackayova V, Cudalbu C, Pouwels PJW, Braissant O. Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies. Anal Biochem 2016; 529:144-157. [PMID: 27840053 DOI: 10.1016/j.ab.2016.11.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 10/20/2022]
Abstract
Creatine (Cr) is an important organic compound acting as intracellular high-energy phosphate shuttle and in energy storage. While located in most cells where it plays its main roles in energy metabolism and cytoprotection, Cr is highly concentrated in muscle and brain tissues, in which Cr also appears to act in osmoregulation and neurotransmission. This review discusses the basis of Cr metabolism, synthesis and transport within brain cells. The importance of Cr in brain function and the consequences of its impaired metabolism in primary and secondary Cr deficiencies are also discussed. Cr and phosphocreatine (PCr) in living systems can be well characterized using in vivo magnetic resonance spectroscopy (MRS). This review describes how 1H MRS allows the measurement of Cr and PCr, and how 31P MRS makes it possible to estimate the creatine kinase (CK) rate constant and so detect dynamic changes in the Cr/PCr/CK system. Absolute quantification by MRS using creatine as internal reference is also debated. The use of in vivo MRS to study brain Cr in a non-invasive way is presented, as well as its use in clinical and preclinical studies, including diagnosis and treatment follow-up in patients.
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Affiliation(s)
- Veronika Rackayova
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Petra J W Pouwels
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Olivier Braissant
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, Lausanne, Switzerland.
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16
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Ganesan M, Feng D, Barton RW, Thomes PG, McVicker BL, Tuma DJ, Osna NA, Kharbanda KK. Creatine Supplementation Does Not Prevent the Development of Alcoholic Steatosis. Alcohol Clin Exp Res 2016; 40:2312-2319. [PMID: 27581622 DOI: 10.1111/acer.13214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/09/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND Alcohol-induced reduction in the hepatocellular S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio impairs the activities of many SAM-dependent methyltransferases. These impairments ultimately lead to the generation of several hallmark features of alcoholic liver injury including steatosis. Guanidinoacetate methyltransferase (GAMT) is an important enzyme that catalyzes the final reaction in the creatine biosynthetic process. The liver is a major site for creatine synthesis which places a substantial methylation burden on this organ as GAMT-mediated reactions consume as much as 40% of all the SAM-derived methyl groups. We hypothesized that dietary creatine supplementation could potentially spare SAM, preserve the hepatocellular SAM:SAH ratio, and thereby prevent the development of alcoholic steatosis and other consequences of impaired methylation reactions. METHODS For these studies, male Wistar rats were pair-fed the Lieber-DeCarli control or ethanol (EtOH) diet with or without 1% creatine supplementation. At the end of 4 to 5 weeks of feeding, relevant biochemical and histological analyses were performed. RESULTS We observed that creatine supplementation neither prevented alcoholic steatosis nor attenuated the alcohol-induced impairments in proteasome activity. The lower hepatocellular SAM:SAH ratio seen in the EtOH-fed rats was also not normalized or SAM levels spared when these rats were fed the creatine-supplemented EtOH diet. However, a >10-fold increased level of creatine was observed in the liver, serum, and hearts of rats fed the creatine-supplemented diets. CONCLUSIONS Overall, dietary creatine supplementation did not prevent alcoholic liver injury despite its known efficacy in preventing high-fat-diet-induced steatosis. Betaine, a promethylating agent that maintains the hepatocellular SAM:SAH, still remains our best option for treating alcoholic steatosis.
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Affiliation(s)
- Murali Ganesan
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Dan Feng
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Ryan W Barton
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Paul G Thomes
- Department of Internal Medicine, Carolinas Medical Center, Charlotte, North Carolina
| | - Benita L McVicker
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Dean J Tuma
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Natalia A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska.
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska.
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska.
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17
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Hanna-El-Daher L, Braissant O. Creatine synthesis and exchanges between brain cells: What can be learned from human creatine deficiencies and various experimental models? Amino Acids 2016; 48:1877-95. [PMID: 26861125 DOI: 10.1007/s00726-016-2189-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/27/2016] [Indexed: 12/11/2022]
Abstract
While it has long been thought that most of cerebral creatine is of peripheral origin, the last 20 years has provided evidence that the creatine synthetic pathway (AGAT and GAMT enzymes) is expressed in the brain together with the creatine transporter (SLC6A8). It has also been shown that SLC6A8 is expressed by microcapillary endothelial cells at the blood-brain barrier, but is absent from surrounding astrocytes, raising the concept that the blood-brain barrier has a limited permeability for peripheral creatine. The first creatine deficiency syndrome in humans was also discovered 20 years ago (GAMT deficiency), followed later by AGAT and SLC6A8 deficiencies, all three diseases being characterized by creatine deficiency in the CNS and essentially affecting the brain. By reviewing the numerous and latest experimental studies addressing creatine transport and synthesis in the CNS, as well as the clinical and biochemical characteristics of creatine-deficient patients, our aim was to delineate a clearer view of the roles of the blood-brain and blood-cerebrospinal fluid barriers in the transport of creatine and guanidinoacetate between periphery and CNS, and on the intracerebral synthesis and transport of creatine. This review also addresses the question of guanidinoacetate toxicity for brain cells, as probably found under GAMT deficiency.
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MESH Headings
- Amidinotransferases/deficiency
- Amidinotransferases/genetics
- Amidinotransferases/metabolism
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/metabolism
- Amino Acid Metabolism, Inborn Errors/pathology
- Animals
- Blood-Brain Barrier/metabolism
- Blood-Brain Barrier/pathology
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/metabolism
- Brain Diseases, Metabolic, Inborn/pathology
- Capillaries/metabolism
- Capillaries/pathology
- Creatine/biosynthesis
- Creatine/deficiency
- Creatine/genetics
- Creatine/metabolism
- Developmental Disabilities/genetics
- Developmental Disabilities/metabolism
- Developmental Disabilities/pathology
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Guanidinoacetate N-Methyltransferase/deficiency
- Guanidinoacetate N-Methyltransferase/genetics
- Guanidinoacetate N-Methyltransferase/metabolism
- Humans
- Intellectual Disability/genetics
- Intellectual Disability/metabolism
- Intellectual Disability/pathology
- Language Development Disorders/genetics
- Language Development Disorders/metabolism
- Language Development Disorders/pathology
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/metabolism
- Mental Retardation, X-Linked/pathology
- Movement Disorders/congenital
- Movement Disorders/genetics
- Movement Disorders/metabolism
- Movement Disorders/pathology
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
- Plasma Membrane Neurotransmitter Transport Proteins/metabolism
- Speech Disorders/genetics
- Speech Disorders/metabolism
- Speech Disorders/pathology
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Affiliation(s)
- Layane Hanna-El-Daher
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, 1011, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, 1011, Lausanne, Switzerland.
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18
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Ellery SJ, Dickinson H, McKenzie M, Walker DW. Dietary interventions designed to protect the perinatal brain from hypoxic-ischemic encephalopathy--Creatine prophylaxis and the need for multi-organ protection. Neurochem Int 2015; 95:15-23. [PMID: 26576837 DOI: 10.1016/j.neuint.2015.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/03/2015] [Accepted: 11/08/2015] [Indexed: 12/12/2022]
Abstract
Birth asphyxia or hypoxia arises from impaired placental gas exchange during labor and remains one of the leading causes of neonatal morbidity and mortality worldwide. It is a condition that can strike in pregnancies that have been uneventful until these final moments, and leads to fundamental loss of cellular energy reserves in the newborn. The cascade of metabolic changes that occurs in the brain at birth as a result of hypoxia can lead to significant damage that evolves over several hours and days, the severity of which can be ameliorated with therapeutic cerebral hypothermia. However, this treatment is only applied to a subset of newborns that meet strict inclusion criteria and is usually administered only in facilities with a high level of medical surveillance. Hence, a number of neuropharmacological interventions have been suggested as adjunct therapies to improve the efficacy of hypothermia, which alone improves survival of the post-hypoxic infant but does not altogether prevent adverse neurological outcomes. In this review we discuss the prospect of using creatine as a dietary supplement during pregnancy and nutritional intervention that can significantly decrease the risk of brain damage in the event of severe oxygen deprivation at birth. Because brain damage can also arise secondarily to compromise of other fetal organs (e.g., heart, diaphragm, kidney), and that compromise of mitochondrial function under hypoxic conditions may be a common mechanism leading to damage of these tissues, we present data suggesting that dietary creatine supplementation during pregnancy may be an effective prophylaxis that can protect the fetus from the multi-organ consequences of severe hypoxia at birth.
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Affiliation(s)
- Stacey J Ellery
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Melbourne, Australia; Department of Obstetrics & Gynaecology, Monash University, Monash Medical Centre, Clayton, Melbourne, Australia.
| | - Hayley Dickinson
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Melbourne, Australia; Department of Obstetrics & Gynaecology, Monash University, Monash Medical Centre, Clayton, Melbourne, Australia
| | - Matthew McKenzie
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Melbourne, Australia
| | - David W Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Melbourne, Australia; Department of Obstetrics & Gynaecology, Monash University, Monash Medical Centre, Clayton, Melbourne, Australia
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19
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MRI/MRS in neuroinflammation: methodology and applications. Clin Transl Imaging 2015; 3:475-489. [PMID: 26705534 PMCID: PMC4679099 DOI: 10.1007/s40336-015-0142-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 08/30/2015] [Indexed: 12/11/2022]
Abstract
Neuroinflammation encompasses a wide range of humoral and cellular responses, not only enabling the CNS to fight various noxious events, including infections and trauma, but also playing a critical role in autoimmune as well as in neurodegenerative diseases. The complex interactions of immune, endothelial, and neuronal cells that take place during inflammation require an equivalent complexity of imaging approaches to be appropriately explored in vivo. Magnetic Resonance provides several complementary techniques that allow to study most mechanisms underlying the brain/immune interaction. In this review, we discuss the MR approaches to the study of endothelial activation, blood-brain barrier permeability alterations, intercellular compartment modifications, immune cell trafficking, and of metabolic alterations linked to immune cell activity. The main advantages and limitations of these techniques are assessed, in view of their exploitation in the clinical arena, where the complementarity of the information that can be obtained has the potential to change our way of studying neuroinflammation, with implications for the management of several CNS diseases.
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20
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Rae CD, Bröer S. Creatine as a booster for human brain function. How might it work? Neurochem Int 2015; 89:249-59. [PMID: 26297632 DOI: 10.1016/j.neuint.2015.08.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/04/2015] [Accepted: 08/15/2015] [Indexed: 01/19/2023]
Abstract
Creatine, a naturally occurring nitrogenous organic acid found in animal tissues, has been found to play key roles in the brain including buffering energy supply, improving mitochondrial efficiency, directly acting as an anti-oxidant and acting as a neuroprotectant. Much of the evidence for these roles has been established in vitro or in pre-clinical studies. Here, we examine the roles of creatine and explore the current status of translation of this research into use in humans and the clinic. Some further possibilities for use of creatine in humans are also discussed.
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Affiliation(s)
- Caroline D Rae
- Neuroscience Research Australia, Barker St Randwick, NSW 2031, Australia; School of Medical Sciences, UNSW, High Street, Randwick, NSW 2052, Australia.
| | - Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
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Wilkie MP, Stecyk JAW, Couturier CS, Sidhu S, Sandvik GK, Nilsson GE. Reversible brain swelling in crucian carp (Carassius carassius) and goldfish (Carassius auratus) in response to high external ammonia and anoxia. Comp Biochem Physiol A Mol Integr Physiol 2015; 184:65-75. [PMID: 25582543 DOI: 10.1016/j.cbpa.2014.12.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/30/2014] [Accepted: 12/31/2014] [Indexed: 01/15/2023]
Abstract
Increased internal ammonia (hyperammonemia) and ischemic/anoxic insults are known to result in a cascade of deleterious events that can culminate in potentially fatal brain swelling in mammals. It is less clear, however, if the brains of fishes respond to ammonia in a similar manner. The present study demonstrated that the crucian carp (Carassius carassius) was not only able to endure high environmental ammonia exposure (HEA; 2 to 22 mmol L(-1)) but that they experienced 30% increases in brain water content at the highest ammonia concentrations. This swelling was accompanied by 4-fold increases in plasma total ammonia (TAmm) concentration, but both plasma TAmm and brain water content were restored to pre-exposure levels following depuration in ammonia-free water. The closely related, ammonia-tolerant goldfish (Carassius auratus) responded similarly to HEA (up to 3.6 mmol L(-1)), which was accompanied by 4-fold increases in brain glutamine. Subsequent administration of the glutamine synthetase inhibitor, methionine sulfoximine (MSO), reduced brain glutamine accumulation by 80% during HEA. However, MSO failed to prevent ammonia-induced increases in brain water content suggesting that glutamine may not be directly involved in initiating ammonia-induced brain swelling in fishes. Although the mechanisms of brain swelling are likely different, exposure to anoxia for 96 h caused similar, but lesser (10%) increases in brain water content in crucian carp. We conclude that brain swelling in some fishes may be a common response to increased internal ammonia or lower oxygen but further research is needed to deduce the underlying mechanisms behind such responses.
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Affiliation(s)
- Michael P Wilkie
- Department of Biology and Institute for Water Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada; Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Jonathan A W Stecyk
- Department of Biosciences, University of Oslo, Oslo, Norway; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, USA
| | | | - Sanya Sidhu
- Department of Biology and Institute for Water Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
| | - Guro K Sandvik
- Department of Biosciences, University of Oslo, Oslo, Norway
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Zahr NM, Mayer D, Rohlfing T, Sullivan EV, Pfefferbaum A. Imaging neuroinflammation? A perspective from MR spectroscopy. Brain Pathol 2014; 24:654-64. [PMID: 25345895 PMCID: PMC4493672 DOI: 10.1111/bpa.12197] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 08/06/2014] [Indexed: 12/30/2022] Open
Abstract
Neuroinflammatory mechanisms contribute to the brain pathology resulting from human immunodeficiency virus (HIV) infection. Magnetic resonance spectroscopy (MRS) has been touted as a suitable method for discriminating in vivo markers of neuroinflammation. The present MRS study was conducted in four groups: alcohol dependent (A, n = 37), HIV-infected (H, n = 33), alcohol dependent + HIV infected (HA, n = 38) and healthy control (C, n = 62) individuals to determine whether metabolites would change in a pattern reflecting neuroinflammation. Significant four-group comparisons were evident only for striatal choline-containing compounds (Cho) and myo-inositol (mI), which follow-up analysis demonstrated were due to higher levels in HA compared with C individuals. To explore the potential relevance of elevated Cho and mI, correlations between blood markers, medication status and alcohol consumption were evaluated in H + HA subjects. Having an acquired immune deficiency syndrome (AIDS)-defining event or hepatitis C was associated with higher Cho; lower Cho levels, however, were associated with low thiamine levels and with highly active antiretroviral HIV treatment (HAART). Higher levels of mI were related to greater lifetime alcohol consumed, whereas HAART was associated with lower mI levels. The current results suggest that competing mechanisms can influence in vivo Cho and mI levels, and that elevations in these metabolites cannot necessarily be interpreted as reflecting a single underlying mechanism, including neuroinflammation.
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Affiliation(s)
- Natalie M. Zahr
- Department of Psychiatry and Behavioral SciencesStanford University School of Medicine (MC5723)StanfordCA
- Neuroscience ProgramSRI InternationalMenlo ParkCA
| | - Dirk Mayer
- Neuroscience ProgramSRI InternationalMenlo ParkCA
- Diagnostic Radiology and Nuclear MedicineUniversity of Maryland School of MedicineBaltimoreMD
| | | | - Edith V. Sullivan
- Department of Psychiatry and Behavioral SciencesStanford University School of Medicine (MC5723)StanfordCA
| | - Adolf Pfefferbaum
- Department of Psychiatry and Behavioral SciencesStanford University School of Medicine (MC5723)StanfordCA
- Neuroscience ProgramSRI InternationalMenlo ParkCA
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van de Kamp JM, Mancini GM, Salomons GS. X-linked creatine transporter deficiency: clinical aspects and pathophysiology. J Inherit Metab Dis 2014; 37:715-33. [PMID: 24789340 DOI: 10.1007/s10545-014-9713-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/27/2014] [Accepted: 04/01/2014] [Indexed: 12/22/2022]
Abstract
Creatine transporter deficiency was discovered in 2001 as an X-linked cause of intellectual disability characterized by cerebral creatine deficiency. This review describes the current knowledge regarding creatine metabolism, the creatine transporter and the clinical aspects of creatine transporter deficiency. The condition mainly affects the brain while other creatine requiring organs, such as the muscles, are relatively spared. Recent studies have provided strong evidence that creatine synthesis also occurs in the brain, leading to the intriguing question of why cerebral creatine is deficient in creatine transporter deficiency. The possible mechanisms explaining the cerebral creatine deficiency are discussed. The creatine transporter knockout mouse provides a good model to study the disease. Over the past years several treatment options have been explored but no treatment has been proven effective. Understanding the pathogenesis of creatine transporter deficiency is of paramount importance in the development of an effective treatment.
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MESH Headings
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/drug therapy
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/pathology
- Animals
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/physiopathology
- Creatine/deficiency
- Creatine/genetics
- Genetic Diseases, X-Linked/genetics
- Humans
- Intellectual Disability/etiology
- Intellectual Disability/genetics
- Membrane Transport Proteins/deficiency
- Membrane Transport Proteins/genetics
- Mental Retardation, X-Linked/complications
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/physiopathology
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
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Affiliation(s)
- Jiddeke M van de Kamp
- Department of Clinical Genetics, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands,
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Kharbanda KK, Todero SL, Moats JC, Harris RM, Osna NA, Thomes PG, Tuma DJ. Alcohol consumption decreases rat hepatic creatine biosynthesis via altered guanidinoacetate methyltransferase activity. Alcohol Clin Exp Res 2014; 38:641-8. [PMID: 24256608 DOI: 10.1111/acer.12306] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 09/17/2013] [Indexed: 02/05/2023]
Abstract
BACKGROUND We have previously shown that decreased S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio generated in livers of alcohol-fed rats can impair the activities of many SAM-dependent methyltransferases. One such methyltransferase is guanidinoacetate methyltransferase (GAMT) that catalyzes the last step of creatine synthesis. As GAMT is the major utilizer of SAM, the purpose of the study was to examine the effects of ethanol (EtOH) on liver creatine levels and GAMT activity. METHODS Male Wistar rats were pair-fed the Lieber-DeCarli control and EtOH diet for 4 to 5 weeks. At the end of the feeding regimen, the liver, kidney, and blood were removed from these rats for subsequent biochemical analyses. RESULTS We observed ~60% decrease in creatine levels in the livers from EtOH-fed rats as compared to controls. The reduction in creatine levels correlated with lower SAM:SAH ratio observed in the livers of the EtOH-fed rats. Further, in vitro experiments with cell-free system and hepatic cells revealed it is indeed elevated SAH and lower SAM:SAH ratio that directly impairs GAMT activity and significantly reduces creatine synthesis. EtOH intake also slightly decreases the hepatocellular uptake of the creatine precursor, guanidinoacetate (GAA), and the GAMT enzyme expression that could additionally contribute to reduced liver creatine synthesis. The consequences of impaired hepatic creatine synthesis by chronic EtOH consumption include (i) increased toxicity due to GAA accumulation in the liver; (ii) reduced protection due to lower creatine levels in the liver, and (iii) reduced circulating and cardiac creatine levels. CONCLUSIONS Chronic EtOH consumption affects the hepatic creatine biosynthetic pathway leading to detrimental consequences not only in the liver but could also affect distal organs such as the heart that depend on a steady supply of creatine from the liver.
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Affiliation(s)
- Kusum K Kharbanda
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska; Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
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25
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Rae CD. A Guide to the Metabolic Pathways and Function of Metabolites Observed in Human Brain 1H Magnetic Resonance Spectra. Neurochem Res 2013; 39:1-36. [PMID: 24258018 DOI: 10.1007/s11064-013-1199-5] [Citation(s) in RCA: 327] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 12/20/2022]
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Deng Y, Bu Q, Hu Z, Deng P, Yan G, Duan J, Hu C, Zhou J, Shao X, Zhao J, Li Y, Zhu R, Zhao Y, Cen X. (1) H-nuclear magnetic resonance-based metabonomic analysis of brain in rhesus monkeys with morphine treatment and withdrawal intervention. J Neurosci Res 2012; 90:2154-62. [PMID: 22847893 DOI: 10.1002/jnr.23109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/23/2012] [Accepted: 06/06/2012] [Indexed: 02/05/2023]
Abstract
Comprehensive cerebral metabolites involved in morphine dependence have not been well explored. To gain a better understanding of morphine dependence and withdrawal therapy in a model highly related to humans, metabolic changes in brain hippocampus and prefrontal cortex (PFC) of rhesus monkeys were measured by (1) H-nuclear magnetic resonance spectroscopy, coupled with partial least squares and orthogonal signal correction analysis. The results showed that concentrations of myoinositol (M-Ins) and taurine were significantly reduced, whereas lactic acid was increased in hippocampus and PFC of morphine-dependent monkeys. Phosphocholine and creatine increased in PFC but decreased in hippocampus after chronic treatment of morphine. Moreover, N-acetyl aspartate (NAA), γ-aminobutyric acid, glutamate, glutathione, methionine, and homocysteic acid also changed in these brain regions. These results suggest that chronic morphine exposure causes profound disturbances of neurotransmitters, membrane, and energy metabolism in the brain. Notably, morphine-induced dysregulations in NAA, creatine, lactic acid, taurine, M-Ins, and phosphocholine were clearly reversed after intervention with methadone or clonidine. Our study highlights the potential of metabolic profiling to enhance our understanding of metabolite alteration and neurobiological actions associated with morphine addiction and withdrawal therapy in primates.
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Affiliation(s)
- Yi Deng
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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The neurochemical profile quantified by in vivo 1H NMR spectroscopy. Neuroimage 2012; 61:342-62. [DOI: 10.1016/j.neuroimage.2011.12.038] [Citation(s) in RCA: 168] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 12/15/2011] [Indexed: 12/13/2022] Open
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Xu S, Zhuo J, Racz J, Shi D, Roys S, Fiskum G, Gullapalli R. Early microstructural and metabolic changes following controlled cortical impact injury in rat: a magnetic resonance imaging and spectroscopy study. J Neurotrauma 2011; 28:2091-102. [PMID: 21761962 DOI: 10.1089/neu.2010.1739] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Understanding tissue alterations at an early stage following traumatic brain injury (TBI) is critical for injury management and limiting severe consequences from secondary injury. We investigated the early microstructural and metabolic profiles using in vivo diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy ((1)H MRS) at 2 and 4 h following a controlled cortical impact injury in the rat brain using a 7.0 Tesla animal MRI system and compared profiles to baseline. Significant decrease in mean diffusivity (MD) and increased fractional anisotropy (FA) was found near the impact site (hippocampus and bilateral thalamus; p<0.05) immediately following TBI, suggesting cytotoxic edema. Although the DTI parameters largely normalized on the contralateral side by 4 h, a large inter-individual variation was observed with a trend towards recovery of MD and FA in the ipsilateral hippocampus and a sustained elevation of FA in the ipsilateral thalamus (p<0.05). Significant reduction in metabolite to total creatine ratios of N-acetylaspartate (NAA, p=0.0002), glutamate (p=0.0006), myo-inositol (Ins, p=0.04), phosphocholine and glycerophosphocholine (PCh+GPC, p=0.03), and taurine (Tau, p=0.009) were observed ipsilateral to the injury as early as 2 h, while glutamine concentration increased marginally (p=0.07). These metabolic alterations remained sustained over 4 h after TBI. Significant reductions of Ins (p=0.024) and Tau (p=0.013) and marginal reduction of NAA (p=0.06) were also observed on the contralateral side at 4 h after TBI. Overall our findings suggest significant microstructural and metabolic alterations as early as 2 h following injury. The tendency towards normalization at 4 h from the DTI data and no further metabolic changes at 4 h from MRS suggest an optimal temporal window of about 3 h for interventions that might limit secondary damage to the brain. Results indicate that early assessment of TBI patients using DTI and MRS may provide valuable information on the available treatment window to limit secondary brain damage.
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Affiliation(s)
- Su Xu
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Vitvitsky V, Garg SK, Banerjee R. Taurine biosynthesis by neurons and astrocytes. J Biol Chem 2011; 286:32002-10. [PMID: 21778230 DOI: 10.1074/jbc.m111.253344] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The physiological roles of taurine, a product of cysteine degradation and one of the most abundant amino acids in the body, remain elusive. Taurine deficiency leads to heart dysfunction, brain development abnormalities, retinal degradation, and other pathologies. The taurine synthetic pathway is proposed to be incomplete in astrocytes and neurons, and metabolic cooperation between these cell types is reportedly needed to complete the pathway. In this study, we analyzed taurine synthesis capability as reported by incorporation of radioactivity from [(35)S]cysteine into taurine, in primary murine astrocytes and neurons, and in several transformed cell lines (human (SH-SY5Y) and murine (N1E-115) neuroblastoma, human astrocytoma (U-87 MG and 1321 N1), and rat glioma (C6)). Extensive incorporation of radioactivity from [(35)S]cysteine into taurine was observed in rat glioma cells as well as in primary mouse astrocytes and neurons, establishing the presence of an intact taurine synthesis pathway in these cells. Interestingly, exposure of cells to cysteine or cysteamine resulted in elevated intracellular hypotaurine without a corresponding increase in taurine levels, suggesting that oxidation of hypotaurine limits taurine synthesis in cells. Consistent with its role as an organic osmolyte, taurine synthesis was stimulated under hypertonic conditions in neurons.
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Affiliation(s)
- Victor Vitvitsky
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, USA
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Nersesova LS. Role of creatine kinase and its substrates in the central nervous system in norm and in various pathologies. J EVOL BIOCHEM PHYS+ 2011. [DOI: 10.1134/s0022093011020034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bothwell JHF, Griffin JL. An introduction to biological nuclear magnetic resonance spectroscopy. Biol Rev Camb Philos Soc 2010; 86:493-510. [PMID: 20969720 DOI: 10.1111/j.1469-185x.2010.00157.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful analytical techniques available to biology. This review is an introduction to the potential of this method and is aimed at readers who have little or no experience in acquiring or analyzing NMR spectra. We focus on spectroscopic applications of the magnetic resonance effect, rather than imaging ones, and explain how various aspects of the NMR phenomenon make it a versatile tool with which to address a number of biological problems. Using detailed examples, we discuss the use of (1) H NMR spectroscopy in mixture analysis and metabolomics, the use of (13) C NMR spectroscopy in tracking isotopomers and determining the flux through metabolic pathways ('fluxomics') and the use of (31) P NMR spectroscopy in monitoring ATP generation and intracellular pH homeotasis in vivo. Further examples demonstrate how NMR spectroscopy can be used to probe the physical environment of a cell by measuring diffusion and the tumbling rates of individual metabolites and how it can determine macromolecular structures by measuring the bonds and distances which separate individual atoms. We finish by outlining some of the key challenges which remain in NMR spectroscopy and we highlight how recent advances-such as increased magnet field strengths, cryogenic cooling, microprobes and hyperpolarisation-are opening new avenues for today's biological NMR spectroscopists.
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Affiliation(s)
- John H F Bothwell
- Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast, UK.
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Singhal A, Nagarajan R, Hinkin CH, Kumar R, Sayre J, Elderkin-Thompson V, Huda A, Gupta RK, Han SH, Thomas MA. Two-dimensional MR spectroscopy of minimal hepatic encephalopathy and neuropsychological correlates in vivo. J Magn Reson Imaging 2010; 32:35-43. [PMID: 20578008 DOI: 10.1002/jmri.22216] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE To evaluate regional cerebral metabolic and structural changes in patients with minimal hepatic encephalopathy (MHE) using two-dimensional (2D) MR spectroscopy (MRS) and T( (1) )-weighted MRI, to correlate the observed MR changes with neuropsychological (NP) test scores, and to compare the diagnostic accuracy of MRI, 2D MRS, and NP tests in discriminating between patients and healthy subjects. MATERIALS AND METHODS Thirty-three MHE patients and 30 healthy controls were investigated. The 2D localized correlated spectroscopy (L-COSY) was performed in the frontal and occipital brain on a 1.5 Tesla (T) MR scanner. The NP test battery included 15 tests, grouped into 6 cognitive domains. Globus pallidus signal intensities were calculated from T(1)-weighted images. RESULTS The 2D MRS showed significant differences in ratios of the following metabolite(s) peaks with respect to creatine (Cr): decreased myo-inositol (mI), choline (Ch), mICh, and increased (glutamate plus glutamine) (Glx) in patients compared with healthy subjects in both occipital and frontal lobes. Frontal lobe taurine also showed a decline in patients. The NP test results revealed declines in cognitive speed, motor function, executive function, and global cognitive status. Significant correlations were found between the altered metabolites and NP tests. Alteration in the mICh/Cr ratio was noted as a powerful discriminant between healthy subjects and the patients. CONCLUSION The study demonstrates that relative metabolite levels determined by 2D MRS, in particular mICh/Cr, provide the best diagnostic prediction for MHE. The results suggest that depletions of myo-inositol, choline and taurine with respect to creatine correlate with measures of neuropsychological impairment.
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Affiliation(s)
- Aparna Singhal
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California 90095-1721, USA
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Béard E, Braissant O. Synthesis and transport of creatine in the CNS: importance for cerebral functions. J Neurochem 2010; 115:297-313. [DOI: 10.1111/j.1471-4159.2010.06935.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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35
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Zahr NM, Mayer D, Rohlfing T, Hasak MP, Hsu O, Vinco S, Orduna J, Luong R, Sullivan EV, Pfefferbaum A. Brain injury and recovery following binge ethanol: evidence from in vivo magnetic resonance spectroscopy. Biol Psychiatry 2010; 67:846-54. [PMID: 20044076 PMCID: PMC2854208 DOI: 10.1016/j.biopsych.2009.10.028] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 10/02/2009] [Accepted: 10/17/2009] [Indexed: 01/24/2023]
Abstract
BACKGROUND The binge-drinking model in rodents using intragastric injections of ethanol (EtOH) for 4 days results in argyrophilic corticolimbic tissue classically interpreted as indicating irreversible neuronal degeneration. However, recent findings suggest that acquired argyrophilia can also identify injured neurons that have the potential to recover. The current in vivo magnetic resonance (MR) imaging and spectroscopy study was conducted to test the hypothesis that binge EtOH exposure would injure but not cause the death of neurons as previously ascertained postmortem. METHODS After baseline MR scanning, 11 of 19 rats received a loading dose of 5 g/kg EtOH via oral gavage, then a maximum of 3 g/kg every 8 hours for 4 days, for a total average cumulative EtOH dose of 43 +/- 1.2 g/kg and average blood alcohol levels of 258 +/- 12 mg/dL. All animals were scanned after 4 days of gavage (post-gavage scan) with EtOH (EtOH group) or dextrose (control [Con] group) and again after 7 days of abstinence from EtOH (recovery scan). RESULTS Tissue shrinkage at the post-gavage scan was reflected by significantly increased lateral ventricular volume in the EtOH group compared with the Con group. At the post-gavage scan, the EtOH group had lower dorsal hippocampal N-acetylaspartate and total creatine and higher choline-containing compounds than the Con group. At the recovery scan, neither ventricular volume nor metabolite levels differentiated the groups. CONCLUSIONS Rapid recovery of ventricular volume and metabolite levels with removal of the causative agent argues for transient rather than permanent effects of a single EtOH binge episode in rats.
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Affiliation(s)
- Natalie M Zahr
- Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd., Stanford, CA 94305, United States,Neuroscience Program, SRI International, Menlo Park, CA, USA
| | - Dirk Mayer
- Neuroscience Program, SRI International, Menlo Park, CA, USA,Radiology Department, Lucas MRS/I Center, Stanford University, Stanford, CA, USA
| | | | - Michael P Hasak
- Neuroscience Program, SRI International, Menlo Park, CA, USA
| | - Oliver Hsu
- Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd., Stanford, CA 94305, United States,Neuroscience Program, SRI International, Menlo Park, CA, USA
| | - Shara Vinco
- Neuroscience Program, SRI International, Menlo Park, CA, USA
| | - Juan Orduna
- Neuroscience Program, SRI International, Menlo Park, CA, USA
| | - Richard Luong
- Department of Comparative Medicine, Stanford University, Stanford, CA, USA
| | - Edith V Sullivan
- Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd., Stanford, CA 94305, United States,corresponding author, , Phone: 650-859-2880, Fax: 650-859-2743
| | - Adolf Pfefferbaum
- Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd., Stanford, CA 94305, United States,Neuroscience Program, SRI International, Menlo Park, CA, USA
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Stein CS, Yancey PH, Martins I, Sigmund RD, Stokes JB, Davidson BL. Osmoregulation of ceroid neuronal lipofuscinosis type 3 in the renal medulla. Am J Physiol Cell Physiol 2010; 298:C1388-400. [PMID: 20219947 DOI: 10.1152/ajpcell.00272.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recessive inheritance of mutations in ceroid neuronal lipofuscinosis type 3 (CLN3) results in juvenile neuronal ceroid lipofuscinosis (JNCL), a childhood neurodegenerative disease with symptoms including loss of vision, seizures, and motor and mental decline. CLN3p is a transmembrane protein with undefined function. Using a Cln3 reporter mouse harboring a nuclear-localized bacterial beta-galactosidase (beta-Gal) gene driven by the native Cln3 promoter, we detected beta-Gal most prominently in epithelial cells of skin, colon, lung, and kidney. In the kidney, beta-Gal-positive nuclei were predominant in medullary collecting duct principal cells, with increased expression along the medullary osmotic gradient. Quantification of Cln3 transcript levels from kidneys of wild-type (Cln3(+/+)) mice corroborated this expression gradient. Reporter mouse-derived renal epithelial cultures demonstrated a tonicity-dependent increase in beta-Gal expression. RT-quantitative PCR determination of Cln3 transcript levels further supported osmoregulation at the Cln3 locus. In vivo, osmoresponsiveness of Cln3 was demonstrated by reduction of medullary Cln3 transcript abundance after furosemide administration. Primary cultures of epithelial cells of the inner medulla from Cln3(lacZ/lacZ) (CLN3p-null) mice showed no defect in osmolyte accumulation or taurine flux, arguing against a requirement for CLN3p in osmolyte import or synthesis. CLN3p-deficient mice with free access to water showed a mild urine-concentrating defect but, upon water deprivation, were able to concentrate their urine normally. Unexpectedly, we found that CLN3p-deficient mice were hyperkalemic and had a low fractional excretion of K(+). Together, these findings suggest an osmoregulated role for CLN3p in renal control of water and K(+) balance.
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Affiliation(s)
- Colleen S Stein
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
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Braissant O. Ammonia toxicity to the brain: effects on creatine metabolism and transport and protective roles of creatine. Mol Genet Metab 2010; 100 Suppl 1:S53-8. [PMID: 20227315 DOI: 10.1016/j.ymgme.2010.02.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 02/08/2010] [Indexed: 11/17/2022]
Abstract
Hyperammonemia can provoke irreversible damage to the developing brain, with the formation of cortical atrophy, ventricular enlargement, demyelination or gray and white matter hypodensities. Among the various pathogenic mechanisms involved, alterations in cerebral energy have been demonstrated. In particular, we could show that ammonia exposure generates a secondary deficiency in creatine in brain cells, by altering the brain expression and activity of the genes allowing creatine synthesis (AGAT and GAMT) and transport (SLC6A8). On the other hand, it is known that creatine administration can exert protective effects in various neurodegenerative processes. We could also show that creatine co-treatment under ammonia exposure can protect developing brain cells from some of the deleterious effects of ammonia, in particular axonal growth impairment. This article focuses on the effects of ammonia exposure on creatine metabolism and transport in developing brain cells, and on the potential neuroprotective properties of creatine in the brain exposed to ammonium.
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Affiliation(s)
- Olivier Braissant
- Inborn Errors of Metabolism, Clinical Chemistry Laboratory, Center Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
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Karl A, Werner A. The use of proton magnetic resonance spectroscopy in PTSD research--meta-analyses of findings and methodological review. Neurosci Biobehav Rev 2009; 34:7-22. [PMID: 19559046 DOI: 10.1016/j.neubiorev.2009.06.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 06/11/2009] [Accepted: 06/16/2009] [Indexed: 10/20/2022]
Abstract
Different neuroimaging techniques provided evidence for structural and functional brain alterations in posttraumatic stress disorder (PTSD). Due to technical improvements, especially concerning localization techniques and more reliable analysis methods, one technique, proton magnetic resonance spectroscopy ((1)H-MRS), has increasingly become of interest because it allows further insight into metabolic mechanisms that may contribute to these alterations. The aim of this article is, therefore, to review recent studies utilizing (1)H-MRS of the hippocampus and other brain structures in PTSD. Using meta-analytic methods, we attempted to answer the question if PTSD, as compared to different types of control samples, is accompanied by altered neurometabolite ratios and concentrations in the tissue of different brain regions. A second intent was to review methodological aspects to advise on a minimal standard for reliable results with respect to the application of (1)H-MRS in PTSD. Finally, we discussed the implications of the findings with respect to current PTSD models and future research.
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Affiliation(s)
- Anke Karl
- School of Psychology, University of Southampton, Building 44, Southampton, UK.
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Haskew-Layton RE, Rudkouskaya A, Jin Y, Feustel PJ, Kimelberg HK, Mongin AA. Two distinct modes of hypoosmotic medium-induced release of excitatory amino acids and taurine in the rat brain in vivo. PLoS One 2008; 3:e3543. [PMID: 18958155 PMCID: PMC2568819 DOI: 10.1371/journal.pone.0003543] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 10/03/2008] [Indexed: 11/19/2022] Open
Abstract
A variety of physiological and pathological factors induce cellular swelling in the brain. Changes in cell volume activate several types of ion channels, which mediate the release of inorganic and organic osmolytes and allow for compensatory cell volume decrease. Volume-regulated anion channels (VRAC) are thought to be responsible for the release of some of organic osmolytes, including the excitatory neurotransmitters glutamate and aspartate. In the present study, we compared the in vivo properties of the swelling-activated release of glutamate, aspartate, and another major brain osmolyte taurine. Cell swelling was induced by perfusion of hypoosmotic (low [NaCl]) medium via a microdialysis probe placed in the rat cortex. The hypoosmotic medium produced several-fold increases in the extracellular levels of glutamate, aspartate and taurine. However, the release of the excitatory amino acids differed from the release of taurine in several respects including: (i) kinetic properties, (ii) sensitivity to isoosmotic changes in [NaCl], and (iii) sensitivity to hydrogen peroxide, which is known to modulate VRAC. Consistent with the involvement of VRAC, hypoosmotic medium-induced release of the excitatory amino acids was inhibited by the anion channel blocker DNDS, but not by the glutamate transporter inhibitor TBOA or Cd2+, which inhibits exocytosis. In order to elucidate the mechanisms contributing to taurine release, we studied its release properties in cultured astrocytes and cortical synaptosomes. Similarities between the results obtained in vivo and in synaptosomes suggest that the swelling-activated release of taurine in vivo may be of neuronal origin. Taken together, our findings indicate that different transport mechanisms and/or distinct cellular sources mediate hypoosmotic medium-induced release of the excitatory amino acids and taurine in vivo.
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Affiliation(s)
- Renée E. Haskew-Layton
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- Burke Medical Research Institute of Cornell University, White Plains, New York, United States of America
| | - Alena Rudkouskaya
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Yiqiang Jin
- Ordway Research Institute, Albany, New York, United States of America
| | - Paul J. Feustel
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | | | - Alexander A. Mongin
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- * E-mail:
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40
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Banerjee R, Vitvitsky V, Garg SK. The undertow of sulfur metabolism on glutamatergic neurotransmission. Trends Biochem Sci 2008; 33:413-9. [PMID: 18703339 DOI: 10.1016/j.tibs.2008.06.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 06/11/2008] [Accepted: 06/12/2008] [Indexed: 11/18/2022]
Abstract
Metabolic interdependence between specialized cells in an organ represents a strategy for energy economy by requiring expression of only a subset of pathway genes in a given cell type. In brain, sulfur metabolism exemplifies this principle of metabolic cooperation between glial and neuronal cells and furnishes three key reagents: S-adenosylmethionine, glutathione and taurine. The pathways for glutathione and taurine syntheses depend on metabolic integration between astrocytes and neurons and intersect with the glutamine-glutamate cycle, which underlies glutamatergic synaptic transmission and requires cooperation between these cell types. We propose that underlying waves of glutamate clearance by astrocytes are activation of cystine import and taurine efflux that result, respectively, from a shared transporter and an increase in solute concentration that triggers osmoregulatory responses.
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Affiliation(s)
- Ruma Banerjee
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA.
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41
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Functions and effects of creatine in the central nervous system. Brain Res Bull 2008; 76:329-43. [DOI: 10.1016/j.brainresbull.2008.02.035] [Citation(s) in RCA: 254] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 02/15/2008] [Accepted: 02/25/2008] [Indexed: 12/12/2022]
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Fisher SK, Cheema TA, Foster DJ, Heacock AM. Volume-dependent osmolyte efflux from neural tissues: regulation by G-protein-coupled receptors. J Neurochem 2008; 106:1998-2014. [PMID: 18518929 DOI: 10.1111/j.1471-4159.2008.05510.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The CNS is particularly vulnerable to reductions in plasma osmolarity, such as occur during hyponatremia, the most commonly encountered electrolyte disorder in clinical practice. In response to a lowered plasma osmolarity, neural cells initially swell but then are able to restore their original volume through the release of osmolytes, both inorganic and organic, and the exit of osmotically obligated water. Given the importance of the maintenance of cell volume within the CNS, mechanisms underlying the release of osmolytes assume major significance. In this context, we review recent evidence obtained from our laboratory and others that indicates that the activation of specific G-protein-coupled receptors can markedly enhance the volume-dependent release of osmolytes from neural cells. Of particular significance is the observation that receptor activation significantly lowers the osmotic threshold at which osmolyte release occurs, thereby facilitating the ability of the cells to respond to small, more physiologically relevant, reductions in osmolarity. The mechanisms underlying G-protein-coupled receptor-mediated osmolyte release and the possibility that this efflux can result in both physiologically beneficial and potentially harmful pathophysiological consequences are discussed.
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Affiliation(s)
- Stephen K Fisher
- Molecular and Behavioral Neuroscience Institute; and Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109-2200, USA.
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43
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van Vliet E, Morath S, Eskes C, Linge J, Rappsilber J, Honegger P, Hartung T, Coecke S. A novel in vitro metabolomics approach for neurotoxicity testing, proof of principle for methyl mercury chloride and caffeine. Neurotoxicology 2008; 29:1-12. [DOI: 10.1016/j.neuro.2007.09.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 09/12/2007] [Accepted: 09/19/2007] [Indexed: 10/22/2022]
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A metabolomic study of brain tissues from aged mice with low expression of the vesicular monoamine transporter 2 (VMAT2) gene. Neurochem Res 2007; 33:292-300. [PMID: 18041582 DOI: 10.1007/s11064-007-9542-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 11/01/2007] [Indexed: 10/22/2022]
Abstract
The vesicular monoamine transporter 2 (VMAT2) sequesters monoamines into synaptic vesicles in preparation for neurotransmission. Samples of cerebellum, cortex, hippocampus, substantia nigra and striatum from VMAT2-deficient mice were compared to age-matched control mice. Multivariate statistical analyses of (1)H NMR spectral profiles separated VMAT2-deficient mice from controls for all five brain regions. Although the data show that metabolic alterations are region- and age-specific, in general, analyses indicated decreases in the concentrations of taurine and creatine/phosphocreatine and increases in glutamate and N-acetyl aspartate in VMAT2-deficient mouse brain tissues. This study demonstrates the efficacy of metabolomics as a functional genomics phenotyping tool for mouse models of neurological disorders, and indicates that mild reductions in the expression of VMAT2 affect normal brain metabolism.
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Wyss M, Braissant O, Pischel I, Salomons GS, Schulze A, Stockler S, Wallimann T. Creatine and creatine kinase in health and disease--a bright future ahead? Subcell Biochem 2007; 46:309-34. [PMID: 18652084 DOI: 10.1007/978-1-4020-6486-9_16] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many links are reported or suspected between the functioning of creatine, phosphocreatine, the creatine kinase isoenzymes or the creatine biosynthesis enzymes on one hand, and health or disease on the other hand. The aim of the present book was to outline our current understanding on many of these links. In this chapter, we summarize the main messages and conclusions presented in this book. In addition, we refer to a number of recent publications that highlight the pleiotropy in physiological functions of creatine and creatine kinase, and which suggest that numerous discoveries on new functions of this system are still ahead of us. Finally, we present our views on the most promising future avenues of research to deepen our knowledge on creatine and creatine kinase. In particular, we elaborate on how state-of-the-art high-throughput analytical ("omics") technologies and systems biology approaches may be used successfully to unravel the complex network of interdependent physiological functions related to creatine and creatine kinase.
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Affiliation(s)
- Markus Wyss
- DSM Nutritional Products Ltd., Biotechnology R&D, Bldg. 203/17B, P.O. Box 3255, CH-4002 Basel, Switzerland
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46
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Pascual JM, Solivera J, Prieto R, Barrios L, López-Larrubia P, Cerdán S, Roda JM. Time Course of Early Metabolic Changes following Diffuse Traumatic Brain Injury in Rats as Detected by1H NMR Spectroscopy. J Neurotrauma 2007; 24:944-59. [PMID: 17600512 DOI: 10.1089/neu.2006.0190] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Experimental models of traumatic brain injury (TBI) provide a useful tool for understanding the cerebral metabolic changes induced by this pathological condition. Here, we report on the time course of changes in cerebral metabolites after TBI and its correlation with early brain morphological changes using a combination of high-resolution proton magnetic resonance spectroscopy ((1)H MRS) and magnetic resonance imaging (MRI). Adult male Sprague-Dawley rats were subjected to closed head impact and examined by MRI at 1, 9, 24, 48, and and 72 h after the injury. Extracts from funnel frozen rat brains were then obtained and analyzed quantitatively by high-resolution (1)H MRS. Finally, statistical multivariate analysis was carried out to identify the combination of cerebral metabolites that best described the time evolution of diffuse TBI. The temporal changes observed in the concentration of cerebral metabolites followed three different patterns. The first pattern included taurine, threonine, and glycine, with concentrations peaking 24 h after the injury. The second pattern included glutamate, GABA, and alanine, with concentrations remaining elevated between 24 and 48 h post-injury. The third one involved creatine-phosphocreatine, N-acetylaspartate, and myo-inositol, with concentrations peaking 48 h after the injury. A multivariate stepwise discriminant analysis revealed that the combination of the organic osmolytes taurine and myo-inositol allowed optimal discrimination among the different time groups. Our findings suggest that the profile of some specific brain molecules that play a role as organic osmolytes can be used to follow-up the progression of the early diffuse brain edema response induced by TBI.
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Affiliation(s)
- José M Pascual
- Department of Neurosurgery, La Princesa University Hospital, Madrid, Spain.
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Tranberg M, Abbas AK, Sandberg M. In Vitro Studies on the Putative Function of N-acetylaspartate as an Osmoregulator. Neurochem Res 2007; 32:1248-55. [PMID: 17401659 DOI: 10.1007/s11064-007-9300-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Efflux and tissue content of N-acetylaspartate (NAA) and amino acids were evaluated from cultured and acutely prepared hippocampal slices in response to changes in osmolarity. The osmoregulator taurine, but not NAA, was lost from both types of slices after moderate reductions in extracellular osmolarity (-60 mOsm) for 10-48 h. Hypoosmotic shock (-166 mOsm) for 5 min resulted in unselective efflux of several amino acids from acutely prepared slices. Notably, the efflux of taurine, but not NAA, was prominent also after the shock. Efflux of NAA was markedly enhanced by NMDA and high K(+), in particular after the stimulation period. The high K(+)-mediated efflux was decreased by high extracellular osmolarity and a NMDA-receptor antagonist. The results indicate that NAA efflux can be induced by a sudden non-physiological decrease in extracellular osmolarity but not by prolonged more moderate changes in osmolarity. The mechanisms behind the efflux of NAA by high K(+) are complex and may involve both swelling and activation of NMDA-receptors.
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Affiliation(s)
- Mattias Tranberg
- Institute of Neuroscience and Physiology, Department of Physiology, Göteborg University, Göteborg, Sweden
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48
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Moffett JR, Ross B, Arun P, Madhavarao CN, Namboodiri AMA. N-Acetylaspartate in the CNS: from neurodiagnostics to neurobiology. Prog Neurobiol 2007; 81:89-131. [PMID: 17275978 PMCID: PMC1919520 DOI: 10.1016/j.pneurobio.2006.12.003] [Citation(s) in RCA: 977] [Impact Index Per Article: 57.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 12/07/2006] [Accepted: 12/11/2006] [Indexed: 01/02/2023]
Abstract
The brain is unique among organs in many respects, including its mechanisms of lipid synthesis and energy production. The nervous system-specific metabolite N-acetylaspartate (NAA), which is synthesized from aspartate and acetyl-coenzyme A in neurons, appears to be a key link in these distinct biochemical features of CNS metabolism. During early postnatal central nervous system (CNS) development, the expression of lipogenic enzymes in oligodendrocytes, including the NAA-degrading enzyme aspartoacylase (ASPA), is increased along with increased NAA production in neurons. NAA is transported from neurons to the cytoplasm of oligodendrocytes, where ASPA cleaves the acetate moiety for use in fatty acid and steroid synthesis. The fatty acids and steroids produced then go on to be used as building blocks for myelin lipid synthesis. Mutations in the gene for ASPA result in the fatal leukodystrophy Canavan disease, for which there is currently no effective treatment. Once postnatal myelination is completed, NAA may continue to be involved in myelin lipid turnover in adults, but it also appears to adopt other roles, including a bioenergetic role in neuronal mitochondria. NAA and ATP metabolism appear to be linked indirectly, whereby acetylation of aspartate may facilitate its removal from neuronal mitochondria, thus favoring conversion of glutamate to alpha ketoglutarate which can enter the tricarboxylic acid cycle for energy production. In its role as a mechanism for enhancing mitochondrial energy production from glutamate, NAA is in a key position to act as a magnetic resonance spectroscopy marker for neuronal health, viability and number. Evidence suggests that NAA is a direct precursor for the enzymatic synthesis of the neuron specific dipeptide N-acetylaspartylglutamate, the most concentrated neuropeptide in the human brain. Other proposed roles for NAA include neuronal osmoregulation and axon-glial signaling. We propose that NAA may also be involved in brain nitrogen balance. Further research will be required to more fully understand the biochemical functions served by NAA in CNS development and activity, and additional functions are likely to be discovered.
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Affiliation(s)
- John R Moffett
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
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Wallimann T. Introduction--creatine: cheap ergogenic supplement with great potential for health and disease. Subcell Biochem 2007; 46:1-16. [PMID: 18652069 DOI: 10.1007/978-1-4020-6486-9_1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Theo Wallimann
- Institute of Cell Biology, ETH Zurich, Hönggerberg HPM-D24.1, Schafmattstrasse 18, CH-8093 Zurich, Switzerland
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50
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Liu HT, Tashmukhamedov BA, Inoue H, Okada Y, Sabirov RZ. Roles of two types of anion channels in glutamate release from mouse astrocytes under ischemic or osmotic stress. Glia 2006; 54:343-57. [PMID: 16883573 DOI: 10.1002/glia.20400] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Astrocytes release glutamate upon hyperexcitation in the normal brain, and in response to pathologic insults such as ischemia and trauma. In our experiments, both hypotonic and ischemic stimuli caused the release of glutamate from cultured mouse astrocytes, which occurred with little or no contribution of gap junction hemichannels, vesicle-mediated exocytosis, or reversed operation of the Na-dependent glutamate transporter. Cell swelling and chemical ischemia activated, in cell-attached membrane patches, anionic channels with large unitary conductance (approximately 400 pS) and inactivation kinetics at potentials more positive than +20 mV or more negative than -20 mV. These properties are different from those of volume-sensitive outwardly rectifying (VSOR) Cl- channels, which were also expressed in these cells and exhibited intermediate unitary conductance (approximately 80 pS) and inactivation kinetics at large positive potentials of more than +40 mV. Both maxi-anion channels and VSOR Cl- channels were permeable to glutamate with permeability ratios of glutamate to chloride of 0.21 +/- 0.07 and 0.15 +/- 0.01, respectively. However, the release of glutamate was significantly more sensitive to Gd3+, a blocker of maxi-anion channels, than to phloretin, a blocker of VSOR Cl- channels. We conclude that these two channels jointly represent a major conductive pathway for the release of glutamate from swollen and ischemia-challenged astrocytes, with the contribution of maxi-anion channels being predominant.
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Affiliation(s)
- Hong-Tao Liu
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
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