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Bhattacharjee P, Wang D, Anderson D, Buckler JN, de Geus E, Yan F, Polekhina G, Schittenhelm R, Creek DJ, Harris LD, Sadler AJ. The immune response to RNA suppresses nucleic acid synthesis by limiting ribose 5-phosphate. EMBO J 2024; 43:2636-2660. [PMID: 38778156 PMCID: PMC11217295 DOI: 10.1038/s44318-024-00100-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 02/29/2024] [Accepted: 03/19/2024] [Indexed: 05/25/2024] Open
Abstract
During infection viruses hijack host cell metabolism to promote their replication. Here, analysis of metabolite alterations in macrophages exposed to poly I:C recognises that the antiviral effector Protein Kinase RNA-activated (PKR) suppresses glucose breakdown within the pentose phosphate pathway (PPP). This pathway runs parallel to central glycolysis and is critical to producing NADPH and pentose precursors for nucleotides. Changes in metabolite levels between wild-type and PKR-ablated macrophages show that PKR controls the generation of ribose 5-phosphate, in a manner distinct from its established function in gene expression but dependent on its kinase activity. PKR phosphorylates and inhibits the Ribose 5-Phosphate Isomerase A (RPIA), thereby preventing interconversion of ribulose- to ribose 5-phosphate. This activity preserves redox control but decreases production of ribose 5-phosphate for nucleotide biosynthesis. Accordingly, the PKR-mediated immune response to RNA suppresses nucleic acid production. In line, pharmacological targeting of the PPP during infection decreases the replication of the Herpes simplex virus. These results identify an immune response-mediated control of host cell metabolism and suggest targeting the RPIA as a potential innovative antiviral treatment.
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Affiliation(s)
- Pushpak Bhattacharjee
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, 3168, Australia
| | - Die Wang
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, 3168, Australia
| | - Dovile Anderson
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Joshua N Buckler
- Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, 5010, New Zealand
| | - Eveline de Geus
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, 3168, Australia
| | - Feng Yan
- Australian Centre for Blood Diseases, Department of Clinical Hematology, Monash University, Clayton, VIC, 3004, Australia
| | - Galina Polekhina
- Department of Epidemiology & Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
| | - Ralf Schittenhelm
- Monash Proteomics & Metabolomics Facility, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Lawrence D Harris
- Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, 5010, New Zealand
| | - Anthony J Sadler
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, 3168, Australia.
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2
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Thirion A, Loots DT, Williams ME, Solomons R, Mason S. An exploratory investigation of the CSF metabolic profile of HIV in a South African paediatric cohort using GCxGC-TOF/MS. Metabolomics 2024; 20:33. [PMID: 38427142 PMCID: PMC10907482 DOI: 10.1007/s11306-024-02098-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
INTRODUCTION Because cerebrospinal fluid (CSF) samples are difficult to obtain for paediatric HIV, few studies have attempted to profile neurometabolic dysregulation. AIM AND OBJECTIVE The aim of this exploratory study was to profile the neurometabolic state of CSF from a South African paediatric cohort using GCxGC-TOF/MS. The study included 54 paediatric cases (< 12 years), 42 HIV-negative controls and 12 HIV-positive individuals. RESULTS The results revealed distinct metabolic alterations in the HIV-infected cohort. In the PLS-DA model, 18 metabolites significantly discriminated between HIV-infected and control groups. In addition, fold-change analysis, Mann-Whitney U tests, and effect size measurements verified these findings. Notably, lactose, myo-inositol, and glycerol, although not significant by p-value alone, demonstrated practical significance based on the effect size. CONCLUSIONS This study provided valuable insights on the impact of HIV on metabolic pathways, including damage to the gut and blood-brain barrier, disruption of bioenergetics processes, gliosis, and a potential marker for antiretroviral therapy. Nevertheless, the study recognized certain constraints, notably a limited sample size and the absence of a validation cohort. Despite these limitations, the rarity of the study's focus on paediatric HIV research underscores the significance and unique contributions of its findings.
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Affiliation(s)
- Anicia Thirion
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, North West, South Africa
| | - Du Toit Loots
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, North West, South Africa
| | - Monray E Williams
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, North West, South Africa
| | - Regan Solomons
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, 7505, South Africa
| | - Shayne Mason
- Department of Biochemistry, Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, North West, South Africa.
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3
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Abstract
Magnetic resonance spectroscopy (MRS), being able to identify and measure some brain components (metabolites) in pathologic lesions and in normal-appearing tissue, offers a valuable additional diagnostic tool to assess several pediatric neurological diseases. In this review we will illustrate the basic principles and clinical applications of brain proton (H1; hydrogen) MRS (H1MRS), by now the only MRS method widely available in clinical practice. Performing H1MRS in the brain is inherently less complicated than in other tissues (e.g., liver, muscle), in which spectra are heavily affected by magnetic field inhomogeneities, respiration artifacts, and dominating signals from the surrounding adipose tissues. H1MRS in pediatric neuroradiology has some advantages over acquisitions in adults (lack of motion due to children sedation and lack of brain iron deposition allow optimal results), but it requires a deep knowledge of pediatric pathologies and familiarity with the developmental changes in spectral patterns, particularly occurring in the first two years of life. Examples from our database, obtained mainly from a 1.5 Tesla clinical scanner in a time span of 15 years, will demonstrate the efficacy of H1MRS in the diagnosis of a wide range of selected pediatric pathologies, like brain tumors, infections, neonatal hypoxic-ischemic encephalopathy, metabolic and white matter disorders.
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Affiliation(s)
- Roberto Liserre
- Department of Radiology, Neuroradiology Unit, ASST Spedali Civili University Hospital, Brescia, Italy
| | - Lorenzo Pinelli
- Department of Radiology, Neuroradiology Unit, ASST Spedali Civili University Hospital, Brescia, Italy
| | - Roberto Gasparotti
- Neuroradiology Unit, Department of Medical-Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
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4
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Shayota BJ, Donti TR, Xiao J, Gijavanekar C, Kennedy AD, Hubert L, Rodan L, Vanderpluym C, Nowak C, Bjornsson HT, Ganetzky R, Berry GT, Pappan KL, Sutton VR, Sun Q, Elsea SH. Untargeted metabolomics as an unbiased approach to the diagnosis of inborn errors of metabolism of the non-oxidative branch of the pentose phosphate pathway. Mol Genet Metab 2020; 131:147-154. [PMID: 32828637 PMCID: PMC8630378 DOI: 10.1016/j.ymgme.2020.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/31/2020] [Accepted: 07/31/2020] [Indexed: 12/27/2022]
Abstract
Inborn errors of metabolism (IEM) involving the non-oxidative pentose phosphate pathway (PPP) include the two relatively rare conditions, transketolase deficiency and transaldolase deficiency, both of which can be difficult to diagnosis given their non-specific clinical presentations. Current biochemical testing approaches require an index of suspicion to consider targeted urine polyol testing. To determine whether a broad-spectrum biochemical test could accurately identify a specific metabolic pattern defining IEMs of the non-oxidative PPP, we employed the use of clinical metabolomic profiling as an unbiased novel approach to diagnosis. Subjects with molecularly confirmed IEMs of the PPP were included in this study. Targeted quantitative analysis of polyols in urine and plasma samples was accomplished with chromatography and mass spectrometry. Semi-quantitative unbiased metabolomic analysis of urine and plasma samples was achieved by assessing small molecules via liquid chromatography and high-resolution mass spectrometry. Results from untargeted and targeted analyses were then compared and analyzed for diagnostic acuity. Two siblings with transketolase (TKT) deficiency and three unrelated individuals with transaldolase (TALDO) deficiency were identified for inclusion in the study. For both IEMs, targeted polyol testing and untargeted metabolomic testing on urine and/or plasma samples identified typical perturbations of the respective disorder. Additionally, untargeted metabolomic testing revealed elevations in other PPP metabolites not typically measured with targeted polyol testing, including ribonate, ribose, and erythronate for TKT deficiency and ribonate, erythronate, and sedoheptulose 7-phosphate in TALDO deficiency. Non-PPP alternations were also noted involving tryptophan, purine, and pyrimidine metabolism for both TKT and TALDO deficient patients. Targeted polyol testing and untargeted metabolomic testing methods were both able to identify specific biochemical patterns indicative of TKT and TALDO deficiency in both plasma and urine samples. In addition, untargeted metabolomics was able to identify novel biomarkers, thereby expanding the current knowledge of both conditions and providing further insight into potential underlying pathophysiological mechanisms. Furthermore, untargeted metabolomic testing offers the advantage of having a single effective biochemical screening test for identification of rare IEMs, like TKT and TALDO deficiencies, that may otherwise go undiagnosed due to their generally non-specific clinical presentations.
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MESH Headings
- Adult
- Biomarkers/blood
- Carbohydrate Metabolism, Inborn Errors/blood
- Carbohydrate Metabolism, Inborn Errors/genetics
- Carbohydrate Metabolism, Inborn Errors/metabolism
- Carbohydrate Metabolism, Inborn Errors/pathology
- Child
- Child, Preschool
- Chromatography, Liquid
- Female
- Humans
- Infant
- Male
- Mass Spectrometry
- Metabolism, Inborn Errors/blood
- Metabolism, Inborn Errors/genetics
- Metabolism, Inborn Errors/metabolism
- Metabolism, Inborn Errors/pathology
- Metabolomics
- Pentose Phosphate Pathway/genetics
- Transaldolase/blood
- Transaldolase/deficiency
- Transaldolase/genetics
- Transaldolase/metabolism
- Transketolase/blood
- Transketolase/deficiency
- Transketolase/genetics
- Young Adult
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Affiliation(s)
- Brian J Shayota
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Taraka R Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jing Xiao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA
| | | | | | - Leroy Hubert
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Lance Rodan
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | | | - Catherine Nowak
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Hans T Bjornsson
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Landspitali University Hospital, Reykjavik, Iceland
| | - Rebecca Ganetzky
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Gerard T Berry
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | | | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA
| | - Qin Sun
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA.
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5
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Kaur P, Wamelink MMC, van der Knaap MS, Girisha KM, Shukla A. Confirmation of a Rare Genetic Leukoencephalopathy due to a Novel Bi-allelic Variant in RPIA. Eur J Med Genet 2019; 62:103708. [PMID: 31247379 DOI: 10.1016/j.ejmg.2019.103708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 03/02/2019] [Accepted: 06/19/2019] [Indexed: 10/26/2022]
Abstract
Ribose 5-phosphate isomerase deficiency is a rare genetic leukoencephalopathy caused by pathogenic sequence variants in RPIA, that encodes ribose 5-phosphate isomerase, an enzyme in the pentose phosphate pathway. Till date, only three individuals with ribose 5-phosphate isomerase deficiency have been described in literature. We report on a subject with RPIA associated progressive leukoencephalopathy with elevated urine arabitol and ribitol levels and a novel missense variant c.770T > C p.(Ile257Thr) in exon 8 of RPIA. We also compare the phenotypes of all the four subjects. Our report confirms the phenotype and the genetic cause of this condition.
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Affiliation(s)
- Parneet Kaur
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Mirjam M C Wamelink
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Clinical Chemistry, Metabolic Laboratory, Amsterdam Neuroscience, De Boelelaan, 1117, Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- Pediatric Neurology, Emma Children's Hospital, Amsterdam University Medical Center, Amsterdam Neuroscience, The Netherlands; Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India.
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6
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Brooks SS, Anderson S, Bhise V, Botti C. Further Delineation of Ribose-5-phosphate Isomerase Deficiency: Report of a Third Case. J Child Neurol 2018; 33:784-787. [PMID: 30088433 DOI: 10.1177/0883073818789316] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ribose-5-phosphate isomerase deficiency, a disorder of the pentose phosphate shunt, was described in 1999. There are 2 previously reported cases of ribose-5-phosphate isomerase deficiency. Here, we describe the clinical course, diagnostic odyssey, and molecular findings in the third case of ribose-5-phosphate isomerase deficiency to further delineate the syndrome. Whole-exome sequencing demonstrated 2 mutations in the ribose-5-phosphate isomerase gene, RPIA, in a child with neonatal onset leukoencephalopathy and psychomotor delays. Urine polyols were elevated confirming deficiency of ribose-5-phosphate isomerase (RPI, EC. 5.3.1.6) and pathogenicity of the variants. Measurement of urine polyols should be considered in cases of early-onset white-matter disease.
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Affiliation(s)
- Susan Sklower Brooks
- 1 Pediatric Medical Genetics, Rutgers, The State University of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Sharon Anderson
- 1 Pediatric Medical Genetics, Rutgers, The State University of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, USA.,2 School of Nursing, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Vikram Bhise
- 3 Child Neurology, Rutgers, The State University of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Christina Botti
- 1 Pediatric Medical Genetics, Rutgers, The State University of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
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7
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Naik N, Shah A, Wamelink MM, van der Knaap MS, Hingwala D. Rare case of ribose 5 phosphate isomerase deficiency with slowly progressive leukoencephalopathy. Neurology 2017; 89:1195-1196. [DOI: 10.1212/wnl.0000000000004361] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 06/06/2017] [Indexed: 11/15/2022] Open
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8
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Stincone A, Prigione A, Cramer T, Wamelink MMC, Campbell K, Cheung E, Olin-Sandoval V, Grüning NM, Krüger A, Tauqeer Alam M, Keller MA, Breitenbach M, Brindle KM, Rabinowitz JD, Ralser M. The return of metabolism: biochemistry and physiology of the pentose phosphate pathway. Biol Rev Camb Philos Soc 2014; 90:927-63. [PMID: 25243985 PMCID: PMC4470864 DOI: 10.1111/brv.12140] [Citation(s) in RCA: 816] [Impact Index Per Article: 81.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 07/07/2014] [Accepted: 07/16/2014] [Indexed: 12/13/2022]
Abstract
The pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. The PPP is important to maintain carbon homoeostasis, to provide precursors for nucleotide and amino acid biosynthesis, to provide reducing molecules for anabolism, and to defeat oxidative stress. The PPP shares reactions with the Entner–Doudoroff pathway and Calvin cycle and divides into an oxidative and non-oxidative branch. The oxidative branch is highly active in most eukaryotes and converts glucose 6-phosphate into carbon dioxide, ribulose 5-phosphate and NADPH. The latter function is critical to maintain redox balance under stress situations, when cells proliferate rapidly, in ageing, and for the ‘Warburg effect’ of cancer cells. The non-oxidative branch instead is virtually ubiquitous, and metabolizes the glycolytic intermediates fructose 6-phosphate and glyceraldehyde 3-phosphate as well as sedoheptulose sugars, yielding ribose 5-phosphate for the synthesis of nucleic acids and sugar phosphate precursors for the synthesis of amino acids. Whereas the oxidative PPP is considered unidirectional, the non-oxidative branch can supply glycolysis with intermediates derived from ribose 5-phosphate and vice versa, depending on the biochemical demand. These functions require dynamic regulation of the PPP pathway that is achieved through hierarchical interactions between transcriptome, proteome and metabolome. Consequently, the biochemistry and regulation of this pathway, while still unresolved in many cases, are archetypal for the dynamics of the metabolic network of the cell. In this comprehensive article we review seminal work that led to the discovery and description of the pathway that date back now for 80 years, and address recent results about genetic and metabolic mechanisms that regulate its activity. These biochemical principles are discussed in the context of PPP deficiencies causing metabolic disease and the role of this pathway in biotechnology, bacterial and parasite infections, neurons, stem cell potency and cancer metabolism.
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Affiliation(s)
- Anna Stincone
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Alessandro Prigione
- Max Delbrueck Centre for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Thorsten Cramer
- Department of Gastroenterology and Hepatology, Molekulares Krebsforschungszentrum (MKFZ), Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Mirjam M C Wamelink
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Centre Amsterdam, De Boelelaaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Kate Campbell
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Eric Cheung
- Cancer Research UK, Beatson Institute, Switchback Road, Glasgow G61 1BD, U.K
| | - Viridiana Olin-Sandoval
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Nana-Maria Grüning
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Antje Krüger
- Max Planck Institute for Molecular Genetics, Ihnestr 73, 14195 Berlin, Germany
| | - Mohammad Tauqeer Alam
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Markus A Keller
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Michael Breitenbach
- Department of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cancer Research UK Cambridge Research Institute (CRI), Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, U.K
| | - Joshua D Rabinowitz
- Department of Chemistry, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, 08544 NJ, U.S.A
| | - Markus Ralser
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K.,Division of Physiology and Metabolism, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7, U.K
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9
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Polyols accumulated in ribose-5-phosphate isomerase deficiency increase mitochondrial superoxide production and improve antioxidant defenses in rats' prefrontal cortex. Int J Dev Neurosci 2014; 37:21-5. [PMID: 24970317 DOI: 10.1016/j.ijdevneu.2014.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 01/24/2023] Open
Abstract
The ribose-5-phosphate isomerase deficiency is an inherited condition, which results in cerebral d-arabitol and ribitol accumulation. Patients present leukoencephalopathy, mental retardation, and psychomotor impairment. Considering that the pathophysiology of this disorder is still unclear, and literature are sparse and contradictory, reporting pro and antioxidant activities of polyols, the main objective of this study was to investigate some parameters of oxidative homeostasis of prefrontal cortex of rats incubated with d-arabitol and ribitol. We found evidences that ribitol promoted an increase in antioxidant enzymes activity (superoxide dismutase, catalase, and glutathione peroxidase), probably secondary to enhanced production of superoxide radical, measured by flow cytometry. Oxidation of proteins and lipids was not induced by polyols. Our data allow us to conclude that, at least in our methodological conditions, arabitol and ribitol probably have a secondary effect on the pathophysiology of ribose-5-phosphate isomerase deficiency.
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10
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Khan MS, Dwivedi S, Priyadarshini M, Tabrez S, Siddiqui MA, Jagirdar H, Al-Senaidy AM, Al-Khedhairy AA, Musarrat J. Ribosylation of bovine serum albumin induces ROS accumulation and cell death in cancer line (MCF-7). EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:811-8. [PMID: 24218080 DOI: 10.1007/s00249-013-0929-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 07/30/2013] [Accepted: 09/10/2013] [Indexed: 01/13/2023]
Abstract
Formation of advanced glycation end products (AGE) is crucially involved in the several pathophysiologies associated with ageing and diabetes, for example arthritis, atherosclerosis, chronic renal insufficiency, Alzheimer's disease, nephropathy, neuropathy, and cataracts. Because of devastating effects of AGE and the significance of bovine serum albumin (BSA) as a transport protein, this study was designed to investigate glycation-induced structural modifications in BSA and their functional consequences in breast cancer cell line (MCF-7). We incubated D-ribose with BSA and monitored formation of D-ribose-glycated BSA by observing changes in the intensity of fluorescence at 410 nm. NBT (nitro blue tetrazolium) assay was performed to confirm formation of keto-amine during glycation. Absorbance at 540 nm (fructosamine) increased markedly with time. Furthermore, intrinsic protein and 8-anilino-1-naphthalenesulfonate (ANS) fluorescence revealed marked conformational changes in BSA upon ribosylation. In addition, a fluorescence assay with thioflavin T (ThT) revealed a remarkable increase in fluorescence at 485 nm in the presence of glycated BSA. This suggests that glycation with D-ribose induced aggregation of BSA into amyloid-like deposits. Circular dichroism (CD) study of native and ribosylated BSA revealed molten globule formation in the glycation pathway of BSA. Functional consequences of ribosylated BSA on cancer cell line, MCF-7 was studied by MTT assay and ROS estimation. The results revealed cytotoxicity of ribosylated BSA on MCF-7 cells.
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Affiliation(s)
- Mohd Shahnawaz Khan
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia,
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11
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Wei Y, Han CS, Zhou J, Liu Y, Chen L, He RQ. d-ribose in glycation and protein aggregation. Biochim Biophys Acta Gen Subj 2012; 1820:488-94. [DOI: 10.1016/j.bbagen.2012.01.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 12/23/2022]
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12
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Abstract
Magnetic resonance spectroscopy (MRS) and the related technique of magnetic resonance spectroscopic imaging (MRSI) are widely used in both clinical and preclinical research for the non-invasive evaluation of brain metabolism. They are also used in medical practice, although their ultimate clinical value continues to be a source of discussion. This chapter reviews the general information content of brain spectra and commonly used protocols for both MRS and MRSI and also touches on data analysis methods and quantitation. The main focus is on proton MRS for application in humans, but many of the methods are also applicable to other nuclei and studies of animal models as well.
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13
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Kossoff EH, Bosarge JL, Miranda MJ, Wiemer-Kruel A, Kang HC, Kim HD. Will seizure control improve by switching from the modified Atkins diet to the traditional ketogenic diet? Epilepsia 2010; 51:2496-9. [PMID: 21204815 DOI: 10.1111/j.1528-1167.2010.02774.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It has been reported that children can maintain seizure control when the ketogenic diet (KD) is transitioned to the less-restrictive modified Atkins diet (MAD). What is unknown, however, is the likelihood of additional seizure control from a switch from the MAD to the KD. Retrospective information was obtained from 27 patients who made this dietary change from four different institutions. Ten (37%) patients had ≥10% additional seizure reduction with the KD over the MAD, of which five became seizure-free. The five children who did not improve on the MAD failed to improve when transitioned to the KD. A higher incidence of improvement with the KD occurred for those with myoclonic-astatic epilepsy (70% vs. 12% for all other etiologies, p = 0.004), including all who became seizure-free. These results suggest that the KD probably represents a "higher dose" of dietary therapy than the MAD, which may particularly benefit those with myoclonic-astatic epilepsy.
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Affiliation(s)
- Eric H Kossoff
- Neurology, The Johns Hopkins University, Baltimore, Maryland, USA.
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14
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The difference between rare and exceptionally rare: molecular characterization of ribose 5-phosphate isomerase deficiency. J Mol Med (Berl) 2010; 88:931-9. [PMID: 20499043 DOI: 10.1007/s00109-010-0634-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/03/2010] [Accepted: 05/04/2010] [Indexed: 12/29/2022]
Abstract
Ribose 5-phosphate isomerase (RPI) deficiency is an enzymopathy of the pentose phosphate pathway. It manifests with progressive leukoencephalopathy and peripheral neuropathy and belongs, with one sole diagnosed case, to the rarest human disorders. The single patient was found compound heterozygous for a RPI frameshift and a missense (RPI(Ala61Val)) allele. Here, we report that two patient-derived cell lines differ in RPI enzyme activity, enzyme concentration, and mRNA expression. Furthermore, we present a transgenic yeast model, which exhibits metabolite- and enzyme-activity changes that correspond to the human syndrome and show that the decrease in RPI activity in patient cells is not fully attributable to the residue exchange. Taken together, our results demonstrate that RPI deficiency is caused by the combination of a RPI null allele with an allele that encodes for a partially active enzyme which has, in addition, cell-type-dependent expression deficits. We speculate that a low probability for comparable traits accounts for the rareness of RPI deficiency.
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15
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van der Knaap M. MR Definition of Novel White Matter Disorders. Neuroradiol J 2009. [DOI: 10.1177/19714009090220s112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- M.S. van der Knaap
- Department of Child Neurology, VU University Medical Center; Amsterdam, The Netherlands
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16
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van der Graaf M. In vivo magnetic resonance spectroscopy: basic methodology and clinical applications. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:527-40. [PMID: 19680645 PMCID: PMC2841275 DOI: 10.1007/s00249-009-0517-y] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 06/12/2009] [Accepted: 06/29/2009] [Indexed: 12/21/2022]
Abstract
The clinical use of in vivo magnetic resonance spectroscopy (MRS) has been limited for a long time, mainly due to its low sensitivity. However, with the advent of clinical MR systems with higher magnetic field strengths such as 3 Tesla, the development of better coils, and the design of optimized radio-frequency pulses, sensitivity has been considerably improved. Therefore, in vivo MRS has become a technique that is routinely used more and more in the clinic. In this review, the basic methodology of in vivo MRS is described-mainly focused on (1)H MRS of the brain-with attention to hardware requirements, patient safety, acquisition methods, data post-processing, and quantification. Furthermore, examples of clinical applications of in vivo brain MRS in two interesting fields are described. First, together with a description of the major resonances present in brain MR spectra, several examples are presented of deviations from the normal spectral pattern associated with inborn errors of metabolism. Second, through examples of MR spectra of brain tumors, it is shown that MRS can play an important role in oncology.
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Affiliation(s)
- Marinette van der Graaf
- Clinical Physics Laboratory, Department of Paediatrics 833, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands.
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17
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18
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Wamelink MMC, Struys EA, Jakobs C. The biochemistry, metabolism and inherited defects of the pentose phosphate pathway: a review. J Inherit Metab Dis 2008; 31:703-17. [PMID: 18987987 DOI: 10.1007/s10545-008-1015-6] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/09/2008] [Accepted: 09/17/2008] [Indexed: 11/27/2022]
Abstract
The recent discovery of two defects (ribose-5-phosphate isomerase deficiency and transaldolase deficiency) in the reversible part of the pentose phosphate pathway (PPP) has stimulated interest in this pathway. In this review we describe the functions of the PPP, its relation to other pathways of carbohydrate metabolism and an overview of the metabolic defects in the reversible part of the PPP.
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Affiliation(s)
- M M C Wamelink
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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19
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Regenold WT, Hisley KC, Phatak P, Marano CM, Obuchowski A, Lefkowitz DM, Sassan A, Ohri S, Phillips TL, Dosanjh N, Conley RR, Gullapalli R. Relationship of cerebrospinal fluid glucose metabolites to MRI deep white matter hyperintensities and treatment resistance in bipolar disorder patients. Bipolar Disord 2008; 10:753-64. [PMID: 19032707 PMCID: PMC3753008 DOI: 10.1111/j.1399-5618.2008.00626.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Both diabetes mellitus and magnetic resonance image (MRI) deep white matter hyperintensities (WMHs) are more common in bipolar disorder (BD) patients than in matched controls. Deep-as opposed to periventricular--WMHs and diabetes are associated with treatment resistance and poorer outcome. This study investigated whether brain glucose metabolism by the polyol pathway--a pathway linked to nervous tissue disease in diabetes--is related to deep WMH volume and treatment resistance in BD patients. METHODS Volumes of fluid-attenuated inversion recovery WMHs were quantified and correlated with cerebrospinal fluid (CSF) concentrations of glucose metabolites in 20 nondiabetic patients with BD and nondiabetic comparison subjects with schizophrenia (n = 15) or transient neurologic symptoms (neurologic controls, n = 15). RESULTS BD patients, but not schizophrenic patients, had significantly greater volumes of deep but not periventricular WMHs compared to neurologic controls. BD subjects also had significantly greater CSF concentrations of sorbitol and fructose (the polyol pathway metabolites of glucose) compared to controls. Significant positive correlations between CSF metabolites and WMH volumes were found only in the BD group and were between deep WMH volumes and CSF sorbitol (rho = 0.487, p = 0.029) and fructose (rho = 0.474, p = 0.035). An index of treatment resistance correlated significantly with deep WMH volume (rho = 0.578, p = 0.008), sorbitol (rho = 0.542, p = 0.013), and fructose (rho = 0.692, p = 0.001) in BD subjects but not in other subjects. CONCLUSIONS This is the first reported evidence of relationships between abnormal brain glucose metabolism and both deep WMHs and treatment resistance in a group of BD patients. Further studies are necessary to determine the significance of these findings to BD pathophysiology.
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Affiliation(s)
- William T Regenold
- Department of Psychiatry, Division of Geriatric Psychiatry, University of Maryland School of Medicine, Baltimore, MD,
| | - K Calvin Hisley
- Department of Diagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Pornima Phatak
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Christopher M Marano
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Abraham Obuchowski
- Department of Diagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David M Lefkowitz
- Department of Diagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amritpal Sassan
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sameer Ohri
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Tony L Phillips
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Narveen Dosanjh
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robert R Conley
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Rao Gullapalli
- Department of Diagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, USA
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20
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Regenold WT, Phatak P, Makley MJ, Stone RD, Kling MA. Cerebrospinal fluid evidence of increased extra-mitochondrial glucose metabolism implicates mitochondrial dysfunction in multiple sclerosis disease progression. J Neurol Sci 2008; 275:106-12. [PMID: 18783801 DOI: 10.1016/j.jns.2008.07.032] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 07/22/2008] [Accepted: 07/31/2008] [Indexed: 11/25/2022]
Abstract
In contrast to relapse, the mechanisms of multiple sclerosis (MS) disease progression are less understood and appear not to be exclusively inflammatory in nature. In this pilot study we investigated the relationship between disturbed CNS energy metabolism and MS disease progression. We tested the hypothesis that cerebrospinal fluid (CSF) concentrations of sorbitol, fructose, and lactate, all metabolites of extra-mitochondrial glucose metabolism, would be elevated in secondary progressive (SP) MS patients and would be associated with worsening neurologic disability. We measured metabolite concentrations by gas chromatographic/mass spectrometric and enzymatic methods in archived CSF samples from 85 MS patients [31 relapsing-remitting (RR) and 54 SP patients] and 18 healthy controls. We found that concentrations of all three metabolites, but not concentrations of glucose or myoinositol, were significantly increased in CSF from SP and, to a lesser degree, RR patients, compared to controls. Furthermore, CSF concentrations of sorbitol and fructose (polyol pathway metabolites), but not lactate (anaerobic glycolysis metabolite), correlated positively and significantly with Expanded Disability Status Scale (EDSS) score, an index of neurologic disability in MS patients. We conclude that extra-mitochondrial glucose metabolism is increased in MS patients and is associated with disease progression evidenced by increasing EDSS score. As extra-mitochondrial glucose metabolism increases with impaired mitochondrial metabolism of glucose, these findings implicate mitochondrial dysfunction in the pathogenesis of MS disease progression. CSF metabolic profiling may be useful in clarifying the role of mitochondrial pathology in progression and in targeting and monitoring therapies for disease progression that aim to preserve or boost mitochondrial glucose metabolism.
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Affiliation(s)
- William T Regenold
- University of Maryland School of Medicine, Department of Psychiatry, Division of Geriatric Psychiatry, Baltimore, MD 21201, USA.
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21
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Betsalel OT, van de Kamp JM, Martínez-Muñoz C, Rosenberg EH, de Brouwer APM, Pouwels PJW, van der Knaap MS, Mancini GMS, Jakobs C, Hamel BCJ, Salomons GS. Detection of low-level somatic and germline mosaicism by denaturing high-performance liquid chromatography in a EURO-MRX family with SLC6A8 deficiency. Neurogenetics 2008; 9:183-90. [DOI: 10.1007/s10048-008-0125-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Accepted: 02/25/2008] [Indexed: 11/28/2022]
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Abstract
The application of MR spectroscopy (MRS) in pediatric brain disorders yields valued information on pathologic processes, such as ischemia, demyelination, gliosis, and neurodegeneration. Because these processes manifest in inborn errors of metabolism, the purposes of this article are to (1) describe the spectral changes that are associated with the relatively common metabolic disorders, with summaries of known spectroscopic features of these disorders; (2) offer suggestions for recognition and distinction of disorders; and (3) provide general guidelines for MRS implementation. Although many conditions have a similar presentation, MRS offers valuable information for the individual patient in diagnosis and therapy when integrated fully into the clinical setting.
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Affiliation(s)
- Kim M Cecil
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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23
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Boddaert N, Ribeiro M, Touati G, Mention K, Valayanopoulos V, Nihoul-Fékété C, Brunelle F, de Lonlay P. [Radiological innovations in the screening and diagnosis of the inborn errors of metabolism]. Med Sci (Paris) 2005; 21:981-6. [PMID: 16274650 DOI: 10.1051/medsci/20052111981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
New metabolic diseases are regularly identified by a genetic or biochemical approach. Indeed, the metabolic diseases result from an enzymatic block with accumulation of a metabolite upstream to the block and deficit of a metabolite downstream. The characterization of these abnormal metabolites by MRI spectroscopy permitted to identify the deficient enzyme in two new groups of diseases, creatine deficiencies and polyol anomalies. Creatine deficiency is implicated in unspecific mental retardation. A low peak of creatine at MRI spectroscopy is evocating of creatine deficiency which is treatable by creatine administration. Deficiency of synthesis of polyols, metabolites on the pentose pathway, represent new described metabolic diseases with variable symptoms including a neurological distress, liver disease, splenomegaly, cutis laxa and renal insufficiency. The deficit of ribose-5-phosphate isomerase, one of the enzymes whose diagnosis is evoked in front of the accumulation of ribitol, arabitol and xylitol leads to a leucodystrophy in adults. This new deficit was highlighted by the identification of an abnormal peak in cerebral MRI-spectroscopy corresponding to the abnormal accumulation of polyols in brain. Congenital hyperinsulinism (HI) is characterized by profound hypoglycaemia related to inappropriate insulin secretion. Focal and diffuse forms of hyperinsulinism share a similar clinical presentation but their treatment is dramatically different. Until recently, preoperative differential diagnosis was based on pancreatic venous sampling, an invasive and technically demanding technique. Positron emission tomography (PET) after injection of [18F]Fluoro-L-DOPA has been evaluated for the preoperative differentiation between focal and diffuse HI, by imaging uptake of radiotracer and the conversion of [18F]Fluoro-L-DOPA into dopamine by DOPA decarboxylase. PET with [18F]Fluoro-L-DOPA has been validated as a reliable test to differentiate diffuse and focal HI and is now a major differential diagnosis tool in infantile hyperinsulinemic hypoglycaemia.
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Affiliation(s)
- Nathalie Boddaert
- Service de radiologie pédiatrique, ERM 0205, Hôpital Necker Enfants-Malades, 149, rue de Sèvres, 75743 Paris Cedex 15, France.
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24
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Patay Z. Diffusion-weighted MR imaging in leukodystrophies. Eur Radiol 2005; 15:2284-303. [PMID: 16021451 DOI: 10.1007/s00330-005-2846-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 05/23/2005] [Accepted: 05/31/2005] [Indexed: 11/30/2022]
Abstract
Leukodystrophies are genetically determined metabolic diseases, in which the underlying biochemical abnormality interferes with the normal build-up and/or maintenance of myelin, which leads to hypo- (or arrested) myelination, or dysmyelination with resultant demyelination. Although conventional magnetic resonance imaging has significantly contributed to recent progress in the diagnostic work-up of these diseases, diffusion-weighted imaging has the potential to further improve our understanding of underlying pathological processes and their dynamics through the assessment of normal and abnormal diffusion properties of cerebral white matter. Evaluation of conventional diffusion-weighted and ADC map images allows the detection of major diffusion abnormalities and the identification of various edema types, of which the so-called myelin edema is particularly relevant to leukodystrophies. Depending on the nature of histopathological changes, stage and progression gradient of diseases, various diffusion-weighted imaging patterns may be seen in leukodystrophies. Absent or low-grade myelin edema is found in mucopolysaccharidoses, GM gangliosidoses, Zellweger disease, adrenomyeloneuropathy, L-2-hydroxyglutaric aciduria, non-ketotic hyperglycinemia, classical phenylketonuria, Van der Knaap disease and the vanishing white matter, medium grade myelin edema in metachromatic leukodystrophy, X-linked adrenoleukodystrophy and HMG coenzyme lyase deficiency and high grade edema in Krabbe disease, Canavan disease, hyperhomocystinemias, maple syrup urine disease and leukodystrophy with brainstem and spinal cord involvement and high lactate.
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Affiliation(s)
- Zoltan Patay
- Department of Radiology, MBC 28, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, 11211, Riyadh, Kingdom of Saudi Arabia.
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25
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Harting I, Jost G, Hacke N, Hartmann M. 1H-Magnetresonanz-Spektroskopie von Hirntumoren. DER NERVENARZT 2005; 76:403-17. [PMID: 15349736 DOI: 10.1007/s00115-004-1797-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Magnetic resonance spectroscopy facilitates non-invasive determination of metabolic changes in vivo. The main metabolites are the neuronal marker N-acetylaspartate (NAA), cholines reflecting membrane turnover, creatine, lactate, and mobile lipids. Primary brain tumours exhibit reduced NAA and increased choline resonances compared to normal brain, and these abnormalities increase with higher malignancy. Increasing choline resonances on follow-up studies correlate with tumour progression, whereas the reduction of initially increased choline resonances indicates a transition from viable tumour to necrotic tissue. Metastases as non-neuroectodermal tumours lack NAA, but demonstrate elevated choline, lactate and lipid resonances. Lymphomas are characterised by massively increased lipid resonances with markedly elevated choline. Prominent alanine resonances are often observed in meningioma. Cystic/necrotic lesions demonstrate elevated lactate regardless of their aetiology. The characteristic finding of prominent resonances from acetate, succinate, and alanine, of leucine, isoleucine and valine in untreated bacterial abscesses allows the differentiation of bacterial abscesses from cystic/necrotic brain tumours.
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Affiliation(s)
- I Harting
- Abteilung Neuroradiologie, Neurologische Klinik, Universitätsklinikum Heidelberg.
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26
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Regenold WT, Hisley KC, Obuchowski A, Lefkowitz DM, Marano C, Hauser P. Relationship of white matter hyperintensities to cerebrospinal fluid glucose polyol pathway metabolites-a pilot study in treatment-resistant affective disorder patients. J Affect Disord 2005; 85:341-50. [PMID: 15780705 DOI: 10.1016/j.jad.2004.10.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Accepted: 10/21/2004] [Indexed: 11/17/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) white matter hyperintensities (WMHs) are found at higher rates in patients with affective disorders, particularly late-life or treatment-resistant disorders. Studies support a vascular pathogenesis for WMHs in late-life onset disorders; however, pathogenesis in typical early-life onset disorders is less clear. Based on associations between diabetes mellitus and both WMHs and affective disorders, this study investigated the relationship between WMHs and brain glucose metabolism by the polyol pathway-a pathway linked to nervous tissue disease in diabetes. METHODS Burdens of fluid-attenuated inversion recovery (FLAIR) WMHs were quantified and correlated with cerebrospinal fluid (CSF) concentrations of glucose metabolites in 10 nondiabetic inpatients with treatment-resistant bipolar, unipolar, and schizoaffective disorders and 10 nondiabetic control patients who had been investigated clinically for transient neurological symptoms. RESULTS Deep but not periventricular WMH burden correlated positively and significantly with elevated CSF concentrations of sorbitol, the specific polyol pathway metabolite of glucose (rho=0.86, p=0.002), in the affective disorders but not the control group. LIMITATIONS This was a pilot study with a relatively small number of subjects; therefore, conclusions are tentative. Controls were not healthy subjects; they were patients with transient neurological symptoms. CONCLUSIONS This is the first reported evidence of a relationship between WMHs and increased brain glucose metabolism by the polyol pathway in patients with affective disorders. More extensive studies are necessary to determine whether this preliminary finding represents a pathogenetic relationship.
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Affiliation(s)
- William T Regenold
- Division of Geriatric Psychiatry, Department of Psychiatry, University of Maryland School of Medicine, and Research Service, VA Maryland Healthcare System, Baltimore, MD 21201, USA
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27
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Mancini GMS, Catsman-Berrevoets CE, de Coo IFM, Aarsen FK, Kamphoven JHJ, Huijmans JG, Duran M, van der Knaap MS, Jakobs C, Salomons GS. Two novel mutations in SLC6A8 cause creatine transporter defect and distinctive X-linked mental retardation in two unrelated Dutch families. Am J Med Genet A 2005; 132A:288-95. [PMID: 15690373 DOI: 10.1002/ajmg.a.30473] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Four Dutch male patients, two brothers from unrelated families were referred for investigation of psychomotor and severe language/speech delay. All four patients showed growth deficiency over the years. Facial features and poor body habitus were quite similar in the patients and in their mothers. Brain MRI showed nonspecific periventricular white matter lesions. In all the patients neuropsychological tests revealed moderate mental retardation, attention deficit and hyperactivity with impulsivity, a semantic-pragmatic language disorder, and oral dyspraxia. This specific cognitive profile is different from other children with mental retardation syndromes and seems to be unique. Excretion of creatine to creatinine ratio in urine of the four boys was increased compared to controls and their creatine uptake in fibroblasts was deficient. In the two brothers from the first pedigree, DNA sequence analysis revealed a novel mutation in the splice donor site in intron 10 (IVS10 + 5G>C, c.1495 + 5G>C) of the SLC6A8 gene leading to skipping of exon 10. In the other sib pair a novel missense mutation (c. 1361C>T; p.Pro544Leu) was found. These are the first families reported, in which the clinical suspicion of a creatine transporter disorder was raised on clinical grounds, before a brain 1H-MRS suggested the diagnosis. Screening of apparently X-linked mental retarded patients with this somatic and behavioral phenotype by the biochemical assay of creatine to creatinine ratio in the urine or DNA sequence analysis of SLC6A8 is worthwhile even when 1H-MRS is not available.
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Affiliation(s)
- G M S Mancini
- Department of Clinical Genetics, Erasmus University MC/Sophia Children's Hospital, Rotterdam, The Netherlands.
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28
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Wolf NI, Willemsen MAAP, Engelke UF, van der Knaap MS, Pouwels PJW, Harting I, Zschocke J, Sistermans EA, Rating D, Wevers RA. Severe hypomyelination associated with increased levels of N-acetylaspartylglutamate in CSF. Neurology 2004; 62:1503-8. [PMID: 15136672 DOI: 10.1212/01.wnl.0000123094.13406.20] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Two unrelated girls had early onset of nystagmus and epilepsy, absent psychomotor development, and almost complete absence of myelin on cerebral MRI. The clinical features and MR images of both patients resembled the connatal form of Pelizaeus-Merzbacher disease (PMD), which is an X-linked recessive disorder caused by duplications or mutations of the proteolipid protein gene (PLP). OBJECTIVE To define a unique neurometabolic disorder with failure of myelination. METHOD S AND RESULTS: 1H-NMR of CSF in both girls was performed repeatedly, and both showed highly elevated concentrations of N-acetylaspartylglutamate (NAAG). The coding sequence of the gene coding for glutamate carboxypeptidase II, which converts NAAG to N-acetylaspartate (NAA) and glutamate, was entirely sequenced but revealed no mutations. Even though both patients are girls, the authors sequenced the PLP gene and found no abnormality. CONCLUSIONS NAAG is an abundant peptide neurotransmitter whose exact role is unclear. NAAG is implicated in two cases of unresolved severe CNS disorder. Its elevated concentration in CSF may be the biochemical hallmark for a novel neurometabolic disorder. The cause of its accumulation is still unclear.
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Affiliation(s)
- N I Wolf
- Department of Pediatric Neurology, University Children's Hospital Heidelberg, Germany
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29
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Viola A, Nicoli F, Denis B, Confort-Gouny S, Le Fur Y, Ranjeva JP, Viout P, Cozzone PJ. High cerebral scyllo-inositol: a new marker of brain metabolism disturbances induced by chronic alcoholism. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 17:47-61. [PMID: 15340856 DOI: 10.1007/s10334-004-0044-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Revised: 06/07/2004] [Accepted: 06/07/2004] [Indexed: 11/25/2022]
Abstract
Cerebral metabolic changes that concur to motor and/or cognitive disorders in actively drinking alcoholics are not well established. We tested the hypothesis that chronic alcoholics exhibit profound alterations in the cerebral metabolism of scyllo-inositol. Brain metabolism was explored in nine actively drinking and 11 recently detoxified chronic alcoholics by in vivo brain (1)H-MRS and in vitro(1)H-MRS of blood serum and cerebrospinal fluid. The cohort was composed of individuals with acute, subacute or chronic encephalopathy or without any clinical encephalopathy. Chronic alcoholism is associated with a hitherto unrecognized accumulation of brain scyllo-inositol. Our results suggest that scyllo-inositol is produced within the central nervous system and shows a diffuse but heterogenous distribution in brain where it can persist several weeks after detoxification. Its highest levels were observed in subjects with a clinically symptomatic alcohol-related encephalopathy. When detected, brain scyllo-inositol takes part in a metabolic encephalopathy since it is associated with reduced N-acetylaspartate and increased creatine. High levels of cerebral scyllo-inositol are correlated with altered glial and neuronal metabolism. Our findings suggest that the accumulation of scyllo-inositol may precede and take part in the development of symptomatic alcoholic metabolic encephalopathy.
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Affiliation(s)
- A Viola
- Centre de Résonance Magnétique, Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, 27 Bd J. Moulin, 13005 Marseille, France.
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30
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Di Rocco M, Biancheri R, Rossi A, Filocamo M, Tortori-Donati P. Genetic disorders affecting white matter in the pediatric age. Am J Med Genet B Neuropsychiatr Genet 2004; 129B:85-93. [PMID: 15274047 DOI: 10.1002/ajmg.b.30029] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pediatric white matter disorders can be distinguished into well-defined leukoencephalopathies, and undefined leukoencephalopathies. The first category may be subdivided into: (a) hypomyelinating disorders; (b) dysmyelinating disorders; (c) leukodystrophies; (d) disorders related to cystic degeneration of myelin; and (e) disorders secondary to axonal damage. The second category, representing up to 50% of leukoencephalopathies in childhood, requires a multidisciplinar approach in order to define novel homogeneous subgroups of patients, possibly representing "new genetic disorders" (such as megalencephalic leukoencepahlopathy with subcortical cysts and vanishing white matter disease that have recently been identified). In the majority of cases, pediatric white matter disorders are inherited diseases. An integrated description of the clinical, neuroimaging and pathophysiological features is crucial for categorizing myelin disorders and better understanding their genetic basis. A review of the genetic disorders affecting white matter in the pediatric age, including some novel entities, is provided.
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Affiliation(s)
- Maja Di Rocco
- Second Unit of Pediatrics, Istituto G. Gaslini, Genova, Italy.
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31
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Abstract
The application of techniques based on in vivo magnetic resonance to the study of leukodystrophies is evaluated. Magnetic resonance imaging (MRI), the most important neuroimaging modality for patients with leukodystrophies, has proven invaluable for the detection of the extent and etiology of white-matter involvement, diagnosis, and monitoring of disease progression. Proton magnetic resonance spectroscopy, which can detect several brain metabolites, including those related to axonal function and myelination, can provide additional diagnostic and prognostic information and, in some cases, allows a rare insight into the biochemical pathology of leukodystrophies. The potential of other advanced magnetic resonance techniques, including diffusion tensor imaging, magnetization transfer contrast, and molecular imaging, is also discussed. In the future, anatomic and physiologic magnetic resonance techniques are expected to be integrated into a single examination that will provide a detailed characterization of white-matter diseases in children.
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Affiliation(s)
- Peter B Barker
- Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Huck JHJ, Roos B, Jakobs C, van der Knaap MS, Verhoeven NM. Evaluation of pentitol metabolism in mammalian tissues provides new insight into disorders of human sugar metabolism. Mol Genet Metab 2004; 82:231-7. [PMID: 15234337 DOI: 10.1016/j.ymgme.2004.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Revised: 04/30/2004] [Accepted: 05/05/2004] [Indexed: 12/27/2022]
Abstract
To more completely elucidate the pathways of sugar metabolism in human, we have evaluated the formation and degradation of pentitols in human fibroblasts and erythrocytes. Cultured human fibroblasts were incubated with d-arabinose, d-ribose, d-ribulose, and d-xylulose. Formation of arabitol and ribitol was analyzed by gas chromatography of the incubation medium and cell homogenate. We found that the pentoses d-arabinose and d-ribose could cross cell membranes, which indicate possible pentitol formation from extracellular pentoses. Fibroblasts formed 17+/-4 nmol arabitol/4 days/mg protein from d-arabinose and ribitol production rates of 70+/-15 nmol/4 days/mg protein were found after d-ribose incubation. Following d-ribulose incubation 13 nmol ribitol/4 days/mg protein was found. Human cultured fibroblasts were also incubated with d-arabitol, ribitol, and xylitol. Analyzing the incubation medium and cell homogenate revealed an absence of pentose formation. However, export of the pentitols arabitol and ribitol across the cell membrane was demonstrated, indicating that pentitols can be cleared from the body without metabolic conversion. Finally, human erythrocytes were incubated with d-/l-arabitol, ribitol, sorbitol, and xylitol. Activities of potential pentitol dehydrogenases were evaluated by a fluorometric assay. No evidence for ribitol and arabitol degradation was observed in human erythrocytes, as compared to polyol dehydrogenase activities ranging from 1.3 to 6.1 pmol NADH/min/microl erythrocytes observed using sorbitol and xylitol. Our results indicate that ribitol and arabitol are metabolic end products in humans.
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Affiliation(s)
- Jojanneke H J Huck
- Department of Child Neurology, VU University Medical Centre, Amsterdam, The Netherlands
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Huck JHJ, Verhoeven NM, Struys EA, Salomons GS, Jakobs C, van der Knaap MS. Ribose-5-phosphate isomerase deficiency: new inborn error in the pentose phosphate pathway associated with a slowly progressive leukoencephalopathy. Am J Hum Genet 2004; 74:745-51. [PMID: 14988808 PMCID: PMC1181951 DOI: 10.1086/383204] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 01/20/2004] [Indexed: 01/20/2023] Open
Abstract
The present article describes the first patient with a deficiency of ribose-5-phosphate isomerase (RPI) (Enzyme Commission number 5.3.1.6) who presented with leukoencephalopathy and peripheral neuropathy. Proton magnetic resonance spectroscopy of the brain revealed highly elevated levels of the polyols ribitol and D-arabitol, which were subsequently also found in high concentrations in body fluids. Deficient activity of RPI, one of the pentose-phosphate-pathway (PPP) enzymes, was demonstrated in fibroblasts. RPI gene-sequence analysis revealed a frameshift and a missense mutation. Recently, we described a patient with liver cirrhosis and abnormal polyol levels in body fluids, related to a deficiency of transaldolase, another enzyme in the PPP. RPI is the second known inborn error in the reversible phase of the PPP, confirming that defects in pentose and polyol metabolism constitute a new area of inborn metabolic disorders.
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Affiliation(s)
- Jojanneke H J Huck
- Department of Child Neurology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands
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Huck JHJ, Struys EA, Verhoeven NM, Jakobs C, van der Knaap MS. Profiling of pentose phosphate pathway intermediates in blood spots by tandem mass spectrometry: application to transaldolase deficiency. Clin Chem 2003; 49:1375-80. [PMID: 12881455 DOI: 10.1373/49.8.1375] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Recently, several patients with abnormal polyol profiles in body fluids have been reported, but the origins of these polyols are unknown. We hypothesized that they are derived from sugar phosphate intermediates of the pentose phosphate pathway (PPP), and we developed a semiquantitative method for profiling of pentose phosphate pathway intermediates. METHODS Sugar phosphates in blood spots were simultaneously analyzed by liquid chromatography-tandem mass spectrometry using an ion-pair-loaded C(18) HPLC column. The tandem mass spectrometer was operated in the multiple-reaction monitoring mode. Enzymatically prepared D-[(13)C(6)]glucose 6-phosphate was used as internal standard. The method was used to study sugar phosphates abnormalities in a patient affected with a deficiency of transaldolase (TALDO1; EC 2.2.1.2). RESULTS In control blood spots, dihydroxyacetone phosphate, pentulose 5-phosphates, pentose 5-phosphates, hexose 6-phosphates, and sedoheptulose 7-phosphate were detected. Detection limits ranged from approximately 100 to approximately 500 nmol/L. Glyceraldehyde 3-phosphate and erythrose 4-phosphate were undetectable. Intra- and interassay imprecision (CVs) were 10-17% and 12-21%, respectively. In blood from the TALDO1-deficient patient, sedoheptulose 7-phosphate was increased. CONCLUSIONS The new method allows investigation of patients in whom a defect in the PPP is suspected. Measurements of sugar phosphate intermediates of the PPP may provide new insights into metabolic defects underlying the accumulating polyols.
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Affiliation(s)
- Jojanneke H J Huck
- Department of Pediatrics, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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van der Knaap MS, van der Voorn P, Barkhof F, Van Coster R, Krägeloh-Mann I, Feigenbaum A, Blaser S, Vles JSH, Rieckmann P, Pouwels PJW. A new leukoencephalopathy with brainstem and spinal cord involvement and high lactate. Ann Neurol 2003; 53:252-8. [PMID: 12557294 DOI: 10.1002/ana.10456] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We identified eight patients with a distinct magnetic resonance imaging pattern of inhomogeneous cerebral white matter abnormalities and selective involvement of brainstem and spinal tracts. Proton magnetic resonance imaging showed increased lactate in the abnormal white matter. Clinically, the patients had slowly progressive pyramidal, cerebellar, and dorsal column dysfunction. The uniform, highly characteristic magnetic resonance imaging pattern and the similarities in clinical and magnetic resonance spectroscopy findings provide evidence for a new disease entity. Autosomal recessive inheritance is likely.
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Affiliation(s)
- Marjo S van der Knaap
- Department of Child Neurology, Free University Medical Center, Amsterdam, The Netherlands.
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Abstract
A female patient, the first child of healthy non-consanguineous parents, presented at the age of 16 months with delayed motor development and facial dysmorphism. In addition she displayed a palatoschizis and multiple skeletal abnormalities as hypoplastic scapulae, hypoplastic os ilea, and an extreme cervical kyphosis. Biochemical investigation of urine revealed no abnormalities except for the presence of large amounts of reducing sugars. The sugar was identified as L-arabinose, which mainly originated from fruit formula in her diet. In addition highly elevated levels of L-arabitol were found in urine, plasma, and cerebrospinal fluid. Although little is known about human arabinose metabolism, we presume that L-arabitol dehydrogenase is deficient in our patient. As polyols are potentially toxic to the central nervous system there could be deleterious long-term effects of this disorder. Withdrawal of dietary fruit led to normalization of polyol levels. The above-mentioned clinical abnormalities are probably not related to this new inborn error of metabolism and should be considered as a separate entity.
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Affiliation(s)
- W Onkenhout
- Department of Pediatrics, Leiden University Medical Center (LUMC), Building 1 P3-P, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
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Abstract
This review centers on important recent advances in the understanding of the role of glial fibrillary acidic protein in Alexander disease and of proteolipid protein in hypomyelinating disorders such as Pelizaeus-Merzbacher and spastic paraplegia. We also describe seven novel leukodystrophies. These include childhood ataxia with central nervous system hypomyelination, a relatively common leukodystrophy syndrome with linkage to chromosome 3 in some patients, and megalencephalic leukoencephalopathy with subcortical cysts whose gene has recently been cloned. These, along with five other disorders, including leukodystrophy with polyol metabolism abnormality, demonstrate that an increasing number of protein and metabolic abnormalities can cause primary myelin disorders.
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Affiliation(s)
- R Schiffmann
- National Institutes of Health, Building 10, Room 3D03, 9000 Rockville Pike, Bethesda, MD 20892-1260, USA.
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Provencher SW. Automatic quantitation of localized in vivo 1H spectra with LCModel. NMR IN BIOMEDICINE 2001; 14:260-4. [PMID: 11410943 DOI: 10.1002/nbm.698] [Citation(s) in RCA: 1215] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The LCModel method analyzes an in vivo spectrum as a Linear Combination of Model in vitro spectra from individual metabolite solutions. Complete model spectra, rather than individual resonances, are used in order to incorporate maximum prior information into the analysis. A nearly model-free constrained regularization method automatically accounts for the baseline and lineshape in vivo without imposing a restrictive parameterized form on them. LCModel is automatic (non-interactive) with no subjective input. Approximately maximum-likelihood estimates of the metabolite concentrations and their uncertainties (Cramér-Rao lower bounds) are obtained. LCModel analyses of spectra from users with fields from 1.5 to 9.4 T and a wide range of sequences, particularly with short TE, are used here to illustrate the capabilities and limitations of LCModel and proton MRS.
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Affiliation(s)
- S W Provencher
- Max Planck Institute for Biophysical Chemistry, D-37070 Göttingen, Germany.
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Verhoeven NM, Huck JH, Roos B, Struys EA, Salomons GS, Douwes AC, van der Knaap MS, Jakobs C. Transaldolase deficiency: liver cirrhosis associated with a new inborn error in the pentose phosphate pathway. Am J Hum Genet 2001; 68:1086-92. [PMID: 11283793 PMCID: PMC1226089 DOI: 10.1086/320108] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2001] [Accepted: 03/08/2001] [Indexed: 11/03/2022] Open
Abstract
This article describes the first patient with a deficiency of transaldolase (TALDO1 [E.C.2.2.1.2]). Clinically, the patient presented with liver cirrhosis and hepatosplenomegaly during early infancy. In urine and plasma, elevated concentrations of ribitol, D-arabitol, and erythritol were found. By incubating the patient's lymphoblasts and erythrocytes with ribose-5-phosphate and subsequently analyzing phosphate sugar metabolites, we discovered a deficiency of transaldolase. Sequence analysis of the transaldolase gene from this patient showed a homozygous deletion of 3 bp. This deletion results in absence of serine at position 171 of the transaldolase protein. This amino acid is invariable between species and is located in a conserved region, indicating its importance for enzyme activity. The detection of this new inborn error of pentose metabolism has implications for the diagnostic workup of liver problems of unknown etiology.
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Affiliation(s)
- N M Verhoeven
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, 1007 MB Amsterdam, The Netherlands.
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Moolenaar SH, van der Knaap MS, Engelke UF, Pouwels PJ, Janssen-Zijlstra FS, Verhoeven NM, Jakobs C, Wevers RA. In vivo and in vitro NMR spectroscopy reveal a putative novel inborn error involving polyol metabolism. NMR IN BIOMEDICINE 2001; 14:167-176. [PMID: 11357181 DOI: 10.1002/nbm.690] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In vivo NMR spectroscopy was performed on the brain of a patient with a leukoencephalopathy, revealing unknown resonances between 3.5 and 4.0 ppm. In addition, urine and CSF of the patient were measured using high-resolution NMR spectroscopy. Also in these in vitro spectra, unknown resonances were observed in the 3.5-4.0 ppm region. Homonuclear (1)H two-dimensional J-resolved spectroscopy (JRES) and (1)H-(1)H correlation spectroscopy (COSY) were performed on the patient's urine for more accurate assignment of resonances. The NMR spectroscopic studies showed that the unknown resonances could be assigned to arabinitol and ribitol. This was confirmed using gas chromatography. The arabinitol was identified as D-arabinitol. The patient is likely to suffer from an as yet unknown inborn error of metabolism affecting D-arabinitol and ribitol metabolism. The primary molecular defect has not been found yet. Urine spectra of patients suffering from diabetes mellitus or galactosemia were recorded for comparison. Resonances outside the 3.2-4.0 ppm region, which are the most easy to recognize in body fluid spectra, allow easy recognition of various sugars and polyols. The paper shows that NMR spectroscopy in body fluids may help identifying unknown resonances observed in in vivo NMR spectra.
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Affiliation(s)
- S H Moolenaar
- Laboratory of Pediatrics and Neurology, University Hospital Nijmegen, 6500 HB Nijmegen, The Netherlands
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Martin E, Capone A, Schneider J, Hennig J, Thiel T. Absence ofN-acetylaspartate in the human brain: Impact on neurospectroscopy? Ann Neurol 2001. [DOI: 10.1002/ana.102] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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