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Bukhari-Parlakturk N, Frucht SJ. Isolated and combined dystonias: Update. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:425-442. [PMID: 37620082 DOI: 10.1016/b978-0-323-98817-9.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Dystonia is a hyperkinetic movement disorder with a unique motor phenomenology that can manifest as an isolated clinical syndrome or combined with other neurological features. This chapter reviews the characteristic features of dystonia phenomenology and the syndromic approach to evaluating the disorders that may allow us to differentiate the isolated and combined syndromes. We also present the most common types of isolated and combined dystonia syndromes. Since accelerated gene discoveries have increased our understanding of the molecular mechanisms of dystonia pathogenesis, we also present isolated and combined dystonia syndromes by shared biological pathways. Examples of these converging mechanisms of the isolated and combined dystonia syndromes include (1) disruption of the integrated response pathway through eukaryotic initiation factor 2 alpha signaling, (2) disease of dopaminergic signaling, (3) alterations in the cerebello-thalamic pathway, and (4) disease of protein mislocalization and stability. The discoveries that isolated and combined dystonia syndromes converge in shared biological pathways will aid in the development of clinical trials and therapeutic strategies targeting these convergent molecular pathways.
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Affiliation(s)
- Noreen Bukhari-Parlakturk
- Department of Neurology, Movement Disorders Division, Duke University (NBP), Durham, NC, United States.
| | - Steven J Frucht
- Department of Neurology, NYU Grossman School of Medicine (SJF), New York, NY, United States
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Winn SR, Dudley S, Scherer T, Rimann N, Thöny B, Boutros S, Krenik D, Raber J, Harding CO. Modeling the cognitive effects of diet discontinuation in adults with phenylketonuria (PKU) using pegvaliase therapy in PAH-deficient mice. Mol Genet Metab 2022; 136:46-64. [PMID: 35339387 PMCID: PMC9106909 DOI: 10.1016/j.ymgme.2022.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 10/18/2022]
Abstract
Existing phenylalanine hydroxylase (PAH)-deficient mice strains are useful models of untreated or late-treated human phenylketonuria (PKU), as most contemporary therapies can only be initiated after weaning and the pups have already suffered irreversible consequences of chronic hyperphenylalaninemia (HPA) during early brain development. Therefore, we sought to evaluate whether enzyme substitution therapy with pegvaliase initiated near birth and administered repetitively to C57Bl/6-Pahenu2/enu2 mice would prevent HPA-related behavioral and cognitive deficits and form a model for early-treated PKU. The main results of three reported experiments are: 1) lifelong weekly pegvaliase treatment prevented the cognitive deficits associated with HPA in contrast to persisting deficits in mice treated with pegvaliase only as adults. 2) Cognitive deficits reappear in mice treated with weekly pegvaliase from birth but in which pegvaliase is discontinued at 3 months age. 3) Twice weekly pegvaliase injection also prevented cognitive deficits but again cognitive deficits emerged in early-treated animals following discontinuation of pegvaliase treatment during adulthood, particularly in females. In all studies, pegvaliase treatment was associated with complete correction of brain monoamine neurotransmitter content and with improved overall growth of the mice as measured by body weight. Mean total brain weight however remained low in all PAH deficient mice regardless of treatment. Application of enzyme substitution therapy with pegvaliase, initiated near birth and continued into adulthood, to PAH-deficient Pahenu2/enu2 mice models contemporary early-treated human PKU. This model will be useful for exploring the differential pathophysiologic effects of HPA at different developmental stages of the murine brain.
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Affiliation(s)
- Shelley R Winn
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Sandra Dudley
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Tanja Scherer
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Nicole Rimann
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Beat Thöny
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Sydney Boutros
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Destine Krenik
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA; Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Cary O Harding
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA.
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The Pah-R261Q mouse reveals oxidative stress associated with amyloid-like hepatic aggregation of mutant phenylalanine hydroxylase. Nat Commun 2021; 12:2073. [PMID: 33824313 PMCID: PMC8024259 DOI: 10.1038/s41467-021-22107-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/25/2021] [Indexed: 01/09/2023] Open
Abstract
Phenylketonuria (PKU) is caused by autosomal recessive variants in phenylalanine hydroxylase (PAH), leading to systemic accumulation of L-phenylalanine (L-Phe) that may reach neurotoxic levels. A homozygous Pah-R261Q mouse, with a highly prevalent misfolding variant in humans, reveals the expected hepatic PAH activity decrease, systemic L-Phe increase, L-tyrosine and L-tryptophan decrease, and tetrahydrobiopterin-responsive hyperphenylalaninemia. Pah-R261Q mice also present unexpected traits, including altered lipid metabolism, reduction of liver tetrahydrobiopterin content, and a metabolic profile indicative of oxidative stress. Pah-R261Q hepatic tissue exhibits large ubiquitin-positive, amyloid-like oligomeric aggregates of mutant PAH that colocalize with selective autophagy markers. Together, these findings reveal that PKU, customarily considered a loss-of-function disorder, can also have toxic gain-of-function contribution from protein misfolding and aggregation. The proteostasis defect and concomitant oxidative stress may explain the prevalence of comorbid conditions in adult PKU patients, placing this mouse model in an advantageous position for the discovery of mutation-specific biomarkers and therapies.
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Kaiser RA, Carlson DF, Allen KL, Webster DA, VanLith CJ, Nicolas CT, Hillin LG, Yu Y, Kaiser CW, Wahoff WR, Hickey RD, Watson AL, Winn SR, Thöny B, Kern DR, Harding CO, Lillegard JB. Development of a porcine model of phenylketonuria with a humanized R408W mutation for gene editing. PLoS One 2021; 16:e0245831. [PMID: 33493163 PMCID: PMC7833140 DOI: 10.1371/journal.pone.0245831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 01/08/2021] [Indexed: 12/15/2022] Open
Abstract
Phenylketonuria (PKU) is a metabolic disorder whereby phenylalanine metabolism is deficient due to allelic variations in the gene for phenylalanine hydroxylase (PAH). There is no cure for PKU other than orthotopic liver transplantation, and the standard of care for patients is limited to dietary restrictions and key amino acid supplementation. Therefore, Pah was edited in pig fibroblasts for the generation of PKU clone piglets that harbor a common and severe human mutation, R408W. Additionally, the proximal region to the mutation was further humanized by introducing 5 single nucleotide polymorphisms (SNPs) to allow for development of gene editing machinery that could be translated directly from the pig model to human PKU patients that harbor at least one classic R408W allele. Resulting piglets were hypopigmented (a single Ossabaw piglet) and had low birthweight (all piglets). The piglets had similar levels of PAH expression, but no detectable enzymatic activity, consistent with the human phenotype. The piglets were fragile and required extensive neonatal care to prevent failure to thrive and early demise. Phenylalanine levels rose sharply when dietary Phe was unrestricted but could be rapidly reduced with a low Phe diet. Fibroblasts isolated from R408W piglets show susceptibility to correction using CRISPR or TALEN, with subsequent homology-directed recombination to correct Pah. This pig model of PKU provides a powerful new tool for development of all classes of therapeutic candidates to treat or cure PKU, as well as unique value for proof-of-concept studies for in vivo human gene editing platforms in the context of this humanized PKU allele.
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Affiliation(s)
- Robert A. Kaiser
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
- Midwest Fetal Care Center, Children’s Hospitals and Clinics of Minnesota, Minneapolis, Minnesota, United States of America
| | | | - Kari L. Allen
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | | | - Caitlin J. VanLith
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Clara T. Nicolas
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
- Faculty of Medicine, University of Barcelona, Barcelona, Spain
| | - Lori G. Hillin
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Yue Yu
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Catherine W. Kaiser
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | - William R. Wahoff
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Raymond D. Hickey
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | | | - Shelley R. Winn
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Beat Thöny
- Department of Pediatrics, University of Zurich, Zurich, Switzerland
| | - Douglas R. Kern
- Recombinetics, Inc., St. Paul, Minnesota, United States of America
| | - Cary O. Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Joseph B. Lillegard
- Department of Surgery, Mayo Clinic, Rochester, Minnesota, United States of America
- Midwest Fetal Care Center, Children’s Hospitals and Clinics of Minnesota, Minneapolis, Minnesota, United States of America
- Pediatric Surgical Associates, Minneapolis, Minnesota, United States of America
- * E-mail:
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Oxidative Stress, Folate Receptor Autoimmunity, and CSF Findings in Severe Infantile Autism. AUTISM RESEARCH AND TREATMENT 2020; 2020:9095284. [PMID: 33294225 PMCID: PMC7688371 DOI: 10.1155/2020/9095284] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 07/26/2020] [Accepted: 08/04/2020] [Indexed: 12/21/2022]
Abstract
Background Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and abnormal brain serotonin turnover are common in autism. Methods Oxidative stress biomarkers with pro- and antioxidants were measured in the severe form of infantile autism (n = 38) and controls (n = 24). Children and parents had repeated testing for serum FR autoantibodies, spinal fluid dopamine and serotonin metabolites, pterins, and N5-methyltetrahydrofolate (MTHF). Statistical analysis assessed correlations between variables. Genetic analysis included the SLC6A4 and SLC29A4 genes encoding synaptic serotonin reuptake proteins. Results Compared to controls, the autism group showed a significant increase in oxidative DNA damage in lymphocytes, plasma ceruloplasmin and copper levels with a high copper/zinc ratio, thiol proteins, and superoxide dismutase (SOD) activity. Vitamin C levels were significantly diminished. In most autistic patients, the vitamin A (64%) and D (70%) levels were low. Serum FR autoantibodies fluctuating over 5–7 week periods presented in 68% of all autistic children, 41% of parents vs. 3.3% of control children and their parents. CSF showed lowered serotonin 5-hydroxyindole acetic acid (5HIAA) metabolites in 13 (34%), a low 5HIAA to HVA (dopamine metabolite) ratio in 5 (13%), low 5HIAA and MTHF in 2 (5%), and low MTHF in 8 patients (21%). A known SLC6A4 mutation was identified only in 1 autistic child with low CSF 5HIAA and a novel SLC29A4 mutation was identified in identical twins. Low CSF MTHF levels among only 26% of subjects can be explained by the fluctuating FR antibody titers. Two or more aberrant pro-oxidant and/or antioxidant factors predisposed to low CSF serotonin metabolites. Three autistic children having low CSF 5HIAA and elevated oxidative stress received antioxidative supplements followed by CSF 5HIAA normalisation. Conclusion In autism, we found diverse combinations for FR autoimmunity and/or oxidative stress, both amenable to treatment. Parental and postnatal FR autoantibodies tend to block folate passage to the brain affecting folate-dependent pathways restored by folinic acid treatment, while an abnormal redox status tends to induce reduced serotonin turnover, corrected by antioxidant therapy. Trial Registration. The case-controlled study was approved in 2008 by the IRB at Liège University (Belgian Number: B70720083916). Lay Summary. Children with severe infantile autism frequently have serum folate receptor autoantibodies that block the transport of the essential vitamin folate across the blood-brain barrier to the brain. Parents are often asymptomatic carriers of these serum folate receptor autoantibodies, which in mothers can block folate passage across the placenta to their unborn child. This folate deficiency during the child's intrauterine development may predispose to neural tube defects and autism. Oxidative stress represents a condition with the presence of elevated toxic oxygen derivatives attributed to an imbalance between the formation and protection against these toxic reactive oxygen derivatives. Oxidative stress was found to be present in autistic children where these reactive oxygen derivatives can cause damage to DNA, which changes DNA function and regulation of gene expression. In addition, excessive amounts of these toxic oxygen derivatives are likely to damage the enzyme producing the neuromessenger serotonin in the brain, diminished in about 1/3 of the autistic children. Testing children with autism for oxidative stress and its origin, as well as testing for serum folate receptor autoantibodies, could open new approaches towards more effective treatments.
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Richards DY, Winn SR, Dudley S, Fedorov L, Rimann N, Thöny B, Harding CO. A novel Pah-exon1 deleted murine model of phenylalanine hydroxylase (PAH) deficiency. Mol Genet Metab 2020; 131:306-315. [PMID: 33051130 PMCID: PMC8173763 DOI: 10.1016/j.ymgme.2020.09.005] [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: 06/20/2020] [Revised: 09/16/2020] [Accepted: 09/23/2020] [Indexed: 12/26/2022]
Abstract
Phenylalanine hydroxylase (PAH) deficiency, colloquially known as phenylketonuria (PKU), is among the most common inborn errors of metabolism and in the past decade has become a target for the development of novel therapeutics such as gene therapy. PAH deficient mouse models have been key to new treatment development, but all prior existing models natively express liver PAH polypeptide as inactive or partially active PAH monomers, which complicates the experimental assessment of protein expression following therapeutic gene, mRNA, protein, or cell transfer. The mutant PAH monomers are able to form hetero-tetramers with and inhibit the overall holoenzyme activity of wild type PAH monomers produced from a therapeutic vector. Preclinical therapeutic studies would benefit from a PKU model that completely lacks both PAH activity and protein expression in liver. In this study, we employed CRISPR/Cas9-mediated gene editing in fertilized mouse embryos to generate a novel mouse model that lacks exon 1 of the Pah gene. Mice that are homozygous for the Pah exon 1 deletion are viable, severely hyperphenylalaninemic, accurately replicate phenotypic features of untreated human classical PKU and lack any detectable liver PAH activity or protein. This model of classical PKU is ideal for further development of gene and cell biologics to treat PKU.
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Affiliation(s)
- Daelyn Y Richards
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Portland, USA
| | - Shelley R Winn
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Portland, USA
| | - Sandra Dudley
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Portland, USA
| | - Lev Fedorov
- Transgenic Mouse Models Core, Oregon Health and Science University, Portland, USA
| | - Nicole Rimann
- Division of Metabolism, University Children's Hospital, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Cary O Harding
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Portland, USA.
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Opladen T, López-Laso E, Cortès-Saladelafont E, Pearson TS, Sivri HS, Yildiz Y, Assmann B, Kurian MA, Leuzzi V, Heales S, Pope S, Porta F, García-Cazorla A, Honzík T, Pons R, Regal L, Goez H, Artuch R, Hoffmann GF, Horvath G, Thöny B, Scholl-Bürgi S, Burlina A, Verbeek MM, Mastrangelo M, Friedman J, Wassenberg T, Jeltsch K, Kulhánek J, Kuseyri Hübschmann O. Consensus guideline for the diagnosis and treatment of tetrahydrobiopterin (BH 4) deficiencies. Orphanet J Rare Dis 2020; 15:126. [PMID: 32456656 PMCID: PMC7251883 DOI: 10.1186/s13023-020-01379-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/07/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Tetrahydrobiopterin (BH4) deficiencies comprise a group of six rare neurometabolic disorders characterized by insufficient synthesis of the monoamine neurotransmitters dopamine and serotonin due to a disturbance of BH4 biosynthesis or recycling. Hyperphenylalaninemia (HPA) is the first diagnostic hallmark for most BH4 deficiencies, apart from autosomal dominant guanosine triphosphate cyclohydrolase I deficiency and sepiapterin reductase deficiency. Early supplementation of neurotransmitter precursors and where appropriate, treatment of HPA results in significant improvement of motor and cognitive function. Management approaches differ across the world and therefore these guidelines have been developed aiming to harmonize and optimize patient care. Representatives of the International Working Group on Neurotransmitter related Disorders (iNTD) developed the guidelines according to the SIGN (Scottish Intercollegiate Guidelines Network) methodology by evaluating all available evidence for the diagnosis and treatment of BH4 deficiencies. CONCLUSION Although the total body of evidence in the literature was mainly rated as low or very low, these consensus guidelines will help to harmonize clinical practice and to standardize and improve care for BH4 deficient patients.
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Affiliation(s)
- Thomas Opladen
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany.
| | - Eduardo López-Laso
- Pediatric Neurology Unit, Department of Pediatrics, University Hospital Reina Sofía, IMIBIC and CIBERER, Córdoba, Spain
| | - Elisenda Cortès-Saladelafont
- Inborn errors of metabolism Unit, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
- Unit of Pediatric Neurology and Metabolic Disorders, Department of Pediatrics, Hospital Germans Trias i Pujol, and Faculty of Medicine, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Toni S Pearson
- Department of Neurology, Washington University School of Medicine, St. Louis, USA
| | - H Serap Sivri
- Department of Pediatrics, Section of Metabolism, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
| | - Yilmaz Yildiz
- Department of Pediatrics, Section of Metabolism, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
| | - Birgit Assmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Manju A Kurian
- Developmental Neurosciences, UCL Great Ormond Street-Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Vincenzo Leuzzi
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Simon Heales
- Neurometabolic Unit, National Hospital, Queen Square, London, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital, Queen Square, London, UK
| | - Francesco Porta
- Department of Pediatrics, AOU Città della Salute e della Scienza, Torino, Italy
| | - Angeles García-Cazorla
- Inborn errors of metabolism Unit, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Tomáš Honzík
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Roser Pons
- First Department of Pediatrics of the University of Athens, Aghia Sofia Hospital, Athens, Greece
| | - Luc Regal
- Department of Pediatric, Pediatric Neurology and Metabolism Unit, UZ Brussel, Brussels, Belgium
| | - Helly Goez
- Department of Pediatrics, University of Alberta Glenrose Rehabilitation Hospital, Edmonton, Canada
| | - Rafael Artuch
- Clinical biochemistry department, Institut de Recerca Sant Joan de Déu, CIBERER and MetabERN Hospital Sant Joan de Déu, Barcelona, Spain
| | - Georg F Hoffmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Gabriella Horvath
- Department of Pediatrics, Division of Biochemical Genetics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital Zurich, Zürich, Switzerland
| | - Sabine Scholl-Bürgi
- Clinic for Pediatrics I, Medical University of Innsbruck, Anichstr 35, Innsbruck, Austria
| | - Alberto Burlina
- U.O.C. Malattie Metaboliche Ereditarie, Dipartimento della Salute della Donna e del Bambino, Azienda Ospedaliera Universitaria di Padova - Campus Biomedico Pietro d'Abano, Padova, Italy
| | - Marcel M Verbeek
- Departments of Neurology and Laboratory Medicine, Alzheimer Centre, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Mario Mastrangelo
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Jennifer Friedman
- UCSD Departments of Neuroscience and Pediatrics, Rady Children's Hospital Division of Neurology; Rady Children's Institute for Genomic Medicine, San Diego, USA
| | - Tessa Wassenberg
- Department of Pediatric, Pediatric Neurology and Metabolism Unit, UZ Brussel, Brussels, Belgium
| | - Kathrin Jeltsch
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Jan Kulhánek
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
| | - Oya Kuseyri Hübschmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
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Froukh T. Genetic study in a family with dopa-responsive dystonia revealed a novel mutation in sepiapterin reductase gene. Pak J Med Sci 2019; 35:1736-1739. [PMID: 31777525 PMCID: PMC6861483 DOI: 10.12669/pjms.35.6.1181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Dopa-responsive dystonia due to sepiapterin reductase deficiency (OMIM#612716) is caused by recessive mutations in the gene encoding sepiapterin reductase (SPR), which plays an important role in the biosynthesis of tetrahydrobiopterin (BH4). One Jordanian patient to first cousin parents is reported in this study. The parents of the proband have recognized the symptoms of their daughter at six months old with motor developmental delay. The symptoms were progressed after-then to include speech delay, seizure, ataxia, oculomotor apraxia, dysarthia and choreoathetosis. Despite of these symptoms, the clinicians in Jordan were unable to diagnose the case. In August 2018, the proband (8 years old) was presented to the department of biotechnology and genetic engineering at Philadelphia University in Jordan for the purposes of performing whole exome sequencing (WES). Analysis of WES data has revealed novel homozygous frameshift variant in the gene SPR (NM_003124.4:c.40delG,p.Ala15Profs*100). The variant is heterozygous in the parents and in the healthy male siblings. Therefore, the studied case was diagnosed with sepiapterin reductase deficiency. Because this disease is likely to be treated recommendations were given to the family immediately to start treatments trials. The case in this study illustrates the difficulties of diagnosing sepiapterin reductase deficiency based on clinical symptoms only and thus renders the possibilities of early management. Also, this study reinforces the importance of running WES to undiagnosed neurodevelopmental cases.
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Affiliation(s)
- Tawfiq Froukh
- Tawfiq Froukh, Department of Biotechnology and Genetic Engineering, Philadelphia University, Jerash Road, Amman (19392) Jordan
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Winn SR, Scherer T, Thöny B, Ying M, Martinez A, Weber S, Raber J, Harding CO. Blood phenylalanine reduction corrects CNS dopamine and serotonin deficiencies and partially improves behavioral performance in adult phenylketonuric mice. Mol Genet Metab 2018; 123:6-20. [PMID: 29331172 PMCID: PMC5786171 DOI: 10.1016/j.ymgme.2017.10.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/17/2017] [Accepted: 10/17/2017] [Indexed: 01/12/2023]
Abstract
Central nervous system (CNS) deficiencies of the monoamine neurotransmitters dopamine and serotonin have been implicated in the pathophysiology of neuropsychiatric dysfunction in human phenylketonuria (PKU). In this study, we confirmed the occurrence of brain dopamine and serotonin deficiencies in association with severe behavioral alterations and cognitive impairments in hyperphenylalaninemic C57BL/6-Pahenu2/enu2 mice, a model of human PKU. Phenylalanine-reducing treatments, including either dietary phenylalanine restriction or liver-directed gene therapy, initiated during adulthood were associated with increased brain monoamine content along with improvements in nesting behavior but without a change in the severe cognitive deficits exhibited by these mice. At euthanasia, there was in Pahenu2/enu2 brain a significant reduction in the protein abundance and maximally stimulated activities of tyrosine hydroxylase (TH) and tryptophan hydroxylase 2 (TPH2), the rate limiting enzymes catalyzing neuronal dopamine and serotonin synthesis respectively, in comparison to levels seen in wild type brain. Phenylalanine-reducing treatments initiated during adulthood did not affect brain TH or TPH2 content or maximal activity. Despite this apparent fixed deficit in striatal TH and TPH2 activities, initiation of phenylalanine-reducing treatments yielded substantial correction of brain monoamine neurotransmitter content, suggesting that phenylalanine-mediated competitive inhibition of already constitutively reduced TH and TPH2 activities is the primary cause of brain monoamine deficiency in Pahenu2 mouse brain. We propose that CNS monoamine deficiency may be the cause of the partially reversible adverse behavioral effects associated with chronic HPA in Pahenu2 mice, but that phenylalanine-reducing treatments initiated during adulthood are unable to correct the neuropathology and attendant cognitive deficits that develop during juvenile life in late-treated Pahenu2/enu2 mice.
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Affiliation(s)
- Shelley R Winn
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Tanja Scherer
- Department of Pediatrics, University of Zurich, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Beat Thöny
- Department of Pediatrics, University of Zurich, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Ming Ying
- Department of Biomedicine, KG Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway
| | - Aurora Martinez
- Department of Biomedicine, KG Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway
| | - Sydney Weber
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA; Department of Neurology, Division of Neuroscience, ONPRC, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA; Department of Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Cary O Harding
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA.
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Kojima K, Anzai R, Ohba C, Goto T, Miyauchi A, Thöny B, Saitsu H, Matsumoto N, Osaka H, Yamagata T. A female case of aromatic l-amino acid decarboxylase deficiency responsive to MAO-B inhibition. Brain Dev 2016; 38:959-963. [PMID: 27371992 DOI: 10.1016/j.braindev.2016.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/22/2016] [Accepted: 06/04/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Aromatic l-amino acid decarboxylase (AADC) deficiency is an autosomal recessive disorder, caused by defects in the DDC gene. AADC catalyzes the synthesis of the neurotransmitters dopamine and serotonin from l-dopa and 5-HT respectively. Most patients are bed ridden for life, with little response to treatment. We now report one female patient who improved her motor and cognitive function after being prescribed a MAO-B inhibitor. CASE A five years old female presented with the typical clinical features of AADC deficiency. She was floppy, with no head control, had intermittent limb dystonia, and an upward deviation of the eyes (oculogyric crisis). This patient possessed compound heterozygous mutations in DDC (p.Trp105Cys, p.Pro129Ser), with a CSF draw indicating abnormal patterns of biogenic amine metabolites, compatible with AADC deficiency. RESULTS After her diagnosis at 3years of age, medication with levodopa and vitamin B6 failed to show any efficacy. Subsequent administration with a MAO-B inhibitor improved her psychomotor functions to the extent that at 5years of age she could walk several meters with support. CONCLUSION Our analyses of chemical findings, together with in silico structure predictions, lead us to hypothesize that this patient retained some AADC activity. In these cases, accurate diagnosis and early treatment should improve patient outcome.
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Affiliation(s)
- Karin Kojima
- Department of Pediatrics, Jichi Medical University, Japan
| | - Rie Anzai
- Department of Neurology, Kanagawa Children's Medical Center, Japan
| | - Chihiro Ohba
- Department of Pediatrics, University of Zürich, Switzerland
| | - Tomohide Goto
- Department of Neurology, Kanagawa Children's Medical Center, Japan
| | | | - Beat Thöny
- Department of Pediatrics, University of Zürich, Switzerland
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University, Graduate School of Medicine, Japan; Department of Biochemistry, Hamamatsu Medical University, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University, Graduate School of Medicine, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Japan.
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11
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Smit M, Bartels AL, van Faassen M, Kuiper A, Niezen-Koning KE, Kema IP, Dierckx RA, de Koning TJ, Tijssen MA. Serotonergic perturbations in dystonia disorders-a systematic review. Neurosci Biobehav Rev 2016; 65:264-75. [PMID: 27073048 DOI: 10.1016/j.neubiorev.2016.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/02/2016] [Accepted: 03/22/2016] [Indexed: 11/26/2022]
Abstract
Dystonia is a hyperkinetic movement disorder characterized by sustained or intermittent muscle contractions. Emerging data describe high prevalences of non-motor symptoms, including psychiatric co-morbidity, as part of the phenotype of dystonia. Basal ganglia serotonin and serotonin-dopamine interactions gain attention, as imbalances are known to be involved in extrapyramidal movement and psychiatric disorders. We systematically reviewed the literature for human and animal studies relating to serotonin and its role in dystonia. An association between dystonia and the serotonergic system was reported with decreased levels of 5-hydroxyindolacetic acid, the main metabolite of serotonin. A relation between dystonia and drugs affecting the serotonergic system was described in 89 cases in 49 papers. Psychiatric co-morbidity was frequently described, but likely underestimated as it was not systematically examined. Currently, there are no good (pharmaco)therapeutic options for most forms of dystonia or associated non-motor symptoms. Further research using selective serotonergic drugs in appropriate models of dystonia is required to establish the role of the serotonergic system in dystonia and to guide us to new therapeutic strategies.
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Affiliation(s)
- M Smit
- University of Groningen, University Medical Center Groningen, Department of Neurology, PO Box 30.001, 9700, RB Groningen, The Netherlands.
| | - A L Bartels
- University of Groningen, University Medical Center Groningen, Department of Neurology, PO Box 30.001, 9700, RB Groningen, The Netherlands; Ommelander Hospital Group, Department of Neurology, PO Box 30.000, 9930 RA Delfzijl, The Netherlands.
| | - M van Faassen
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, PO Box 30.001, 9700, RB Groningen, The Netherlands.
| | - A Kuiper
- University of Groningen, University Medical Center Groningen, Department of Neurology, PO Box 30.001, 9700, RB Groningen, The Netherlands.
| | - K E Niezen-Koning
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, PO Box 30.001, 9700, RB Groningen, The Netherlands.
| | - I P Kema
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, PO Box 30.001, 9700, RB Groningen, The Netherlands.
| | - R A Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, PO Box 30.001, 9700 RB Groningen, The Netherlands.
| | - T J de Koning
- University of Groningen, University Medical Center Groningen, Department of Genetics, PO Box 30.001, 9700 RB Groningen, The Netherlands.
| | - M A Tijssen
- University of Groningen, University Medical Center Groningen, Department of Neurology, PO Box 30.001, 9700, RB Groningen, The Netherlands.
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12
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Winn SR, Scherer T, Thöny B, Harding CO. High dose sapropterin dihydrochloride therapy improves monoamine neurotransmitter turnover in murine phenylketonuria (PKU). Mol Genet Metab 2016; 117:5-11. [PMID: 26653793 PMCID: PMC4706464 DOI: 10.1016/j.ymgme.2015.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 11/25/2015] [Indexed: 01/08/2023]
Abstract
Central nervous system (CNS) deficiencies of the monoamine neurotransmitters, dopamine and serotonin, have been implicated in the pathophysiology of neuropsychiatric dysfunction in phenylketonuria (PKU). Increased brain phenylalanine concentration likely competitively inhibits the activities of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), the rate limiting steps in dopamine and serotonin synthesis respectively. Tetrahydrobiopterin (BH4) is a required cofactor for TH and TPH activity. Our hypothesis was that treatment of hyperphenylalaninemic Pah(enu2/enu2) mice, a model of human PKU, with sapropterin dihydrochloride, a synthetic form of BH4, would stimulate TH and TPH activities leading to improved dopamine and serotonin synthesis despite persistently elevated brain phenylalanine. Sapropterin (20, 40, or 100mg/kg body weight in 1% ascorbic acid) was administered daily for 4 days by oral gavage to Pah(enu2/enu2) mice followed by measurement of brain biopterin, phenylalanine, tyrosine, tryptophan and monoamine neurotransmitter content. A significant increase in brain biopterin content was detected only in mice that had received the highest sapropterin dose, 100mg/kg. Blood and brain phenylalanine concentrations were unchanged by sapropterin therapy. Sapropterin therapy also did not alter the absolute amounts of dopamine and serotonin in brain but was associated with increased homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), dopamine and serotonin metabolites respectively, in both wild type and Pah(enu2/enu2) mice. Oral sapropterin therapy likely does not directly affect central nervous system monoamine synthesis in either wild type or hyperphenylalaninemic mice but may stimulate synaptic neurotransmitter release and subsequent metabolism.
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Affiliation(s)
- Shelley R Winn
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Tanja Scherer
- Department of Pediatrics, University of Zurich, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Beat Thöny
- Department of Pediatrics, University of Zurich, Steinweissstrasse 75, Zurich CH-8032, Switzerland
| | - Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA.
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13
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Korner G, Noain D, Ying M, Hole M, Flydal MI, Scherer T, Allegri G, Rassi A, Fingerhut R, Becu-Villalobos D, Pillai S, Wueest S, Konrad D, Lauber-Biason A, Baumann CR, Bindoff LA, Martinez A, Thöny B. Brain catecholamine depletion and motor impairment in a Th knock-in mouse with type B tyrosine hydroxylase deficiency. Brain 2015; 138:2948-63. [PMID: 26276013 DOI: 10.1093/brain/awv224] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 06/17/2015] [Indexed: 12/16/2023] Open
Abstract
Tyrosine hydroxylase catalyses the hydroxylation of L-tyrosine to l-DOPA, the rate-limiting step in the synthesis of catecholamines. Mutations in the TH gene encoding tyrosine hydroxylase are associated with the autosomal recessive disorder tyrosine hydroxylase deficiency, which manifests phenotypes varying from infantile parkinsonism and DOPA-responsive dystonia, also termed type A, to complex encephalopathy with perinatal onset, termed type B. We generated homozygous Th knock-in mice with the mutation Th-p.R203H, equivalent to the most recurrent human mutation associated with type B tyrosine hydroxylase deficiency (TH-p.R233H), often unresponsive to l-DOPA treatment. The Th knock-in mice showed normal survival and food intake, but hypotension, hypokinesia, reduced motor coordination, wide-based gate and catalepsy. This phenotype was associated with a gradual loss of central catecholamines and the serious manifestations of motor impairment presented diurnal fluctuation but did not improve with standard l-DOPA treatment. The mutant tyrosine hydroxylase enzyme was unstable and exhibited deficient stabilization by catecholamines, leading to decline of brain tyrosine hydroxylase-immunoreactivity in the Th knock-in mice. In fact the substantia nigra presented an almost normal level of mutant tyrosine hydroxylase protein but distinct absence of the enzyme was observed in the striatum, indicating a mutation-associated mislocalization of tyrosine hydroxylase in the nigrostriatal pathway. This hypomorphic mouse model thus provides understanding on pathomechanisms in type B tyrosine hydroxylase deficiency and a platform for the evaluation of novel therapeutics for movement disorders with loss of dopaminergic input to the striatum.
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Affiliation(s)
- Germaine Korner
- 1 Division of Metabolism, Department of Paediatrics, University of Zürich, Zürich, Switzerland 2 Affiliated with the Neuroscience Centre Zurich ZNZ, Zürich, Switzerland 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland
| | - Daniela Noain
- 4 Department of Neurology, University Hospital of Zurich, Zürich, Switzerland
| | - Ming Ying
- 5 Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Magnus Hole
- 5 Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Marte I Flydal
- 5 Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Tanja Scherer
- 1 Division of Metabolism, Department of Paediatrics, University of Zürich, Zürich, Switzerland 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland
| | - Gabriella Allegri
- 1 Division of Metabolism, Department of Paediatrics, University of Zürich, Zürich, Switzerland 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland
| | - Anahita Rassi
- 6 Division of Clinical Chemistry and Biochemistry, Department of Paediatrics, University of Zürich, Zürich, Switzerland
| | - Ralph Fingerhut
- 7 Swiss Newborn Screening Laboratory, University Children's Hospital, Zurich, Switzerland 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland
| | | | - Samyuktha Pillai
- 9 Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Stephan Wueest
- 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland 10 Division of Endocrinology, Department of Pediatrics, University of Zurich, Switzerland
| | - Daniel Konrad
- 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland 10 Division of Endocrinology, Department of Pediatrics, University of Zurich, Switzerland
| | - Anna Lauber-Biason
- 11 Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Christian R Baumann
- 2 Affiliated with the Neuroscience Centre Zurich ZNZ, Zürich, Switzerland 4 Department of Neurology, University Hospital of Zurich, Zürich, Switzerland
| | - Laurence A Bindoff
- 12 Department of Clinical Medicine K1, University of Bergen, Norway 13 Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Aurora Martinez
- 5 Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Beat Thöny
- 1 Division of Metabolism, Department of Paediatrics, University of Zürich, Zürich, Switzerland 2 Affiliated with the Neuroscience Centre Zurich ZNZ, Zürich, Switzerland 3 Affiliated with the Children's Research Centre CRC, Zürich, Switzerland
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14
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Protective effect of Bauhinia tomentosa on acetic acid induced ulcerative colitis by regulating antioxidant and inflammatory mediators. Int Immunopharmacol 2013; 16:57-66. [PMID: 23538025 DOI: 10.1016/j.intimp.2013.03.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 02/28/2013] [Accepted: 03/06/2013] [Indexed: 12/14/2022]
Abstract
Inflammatory bowel diseases (IBD), including Crohn's disease and Ulcerative colitis (UC), are life-long and recurrent disorders of the gastrointestinal tract with unknown etiology. The present study is designed to evaluate the ameliorative effect of Bauhinia tomentosa during ulcerative colitis (UC). Three groups of animals (n=6) were treated with B. tomentosa (5, 10, 20 mg/kg B.wt respectively) for 5 consecutive days before induction of UC. UC was induced by intracolonic injection of 3% acetic acid. The colonic mucosal injury was assessed by macroscopic scoring and histological examination. Furthermore, the mucosal content of lipid peroxidation (LPO), reduced glutathione (GSH), nitric oxide (NO), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity confirms that B. tomentosa could significantly inhibit colitis in a dose dependent manner. The myeloperoxidase (MPO), tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS) expression studies and lactate dehydrogenase (LDH) assay also supported that B. tomentosa could significantly inhibit experimental colitis. The effect was comparable to the standard drug sulfasalazine. Colonic mucosal injury parallels with the result of histological and biochemical evaluations. The extracts obtained from B. tomentosa possess active substances, which exert marked protective effects in acute experimental colitis, possibly by regulating the antioxidant and inflammatory mediators.
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15
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Franklin TB, Linder N, Russig H, Thöny B, Mansuy IM. Influence of early stress on social abilities and serotonergic functions across generations in mice. PLoS One 2011; 6:e21842. [PMID: 21799751 PMCID: PMC3143115 DOI: 10.1371/journal.pone.0021842] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/06/2011] [Indexed: 11/22/2022] Open
Abstract
Exposure to adverse environments during early development is a known risk factor for several psychiatric conditions including antisocial behavior and personality disorders. Here, we induced social anxiety and altered social recognition memory in adult mice using unpredictable maternal separation and maternal stress during early postnatal life. We show that these social defects are not only pronounced in the animals directly subjected to stress, but are also transmitted to their offspring across two generations. The defects are associated with impaired serotonergic signaling, in particular, reduced 5HT1A receptor expression in the dorsal raphe nucleus, and increased serotonin level in a dorsal raphe projection area. These findings underscore the susceptibility of social behaviors and serotonergic pathways to early stress, and the persistence of their perturbation across generations.
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Affiliation(s)
- Tamara B. Franklin
- Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
| | - Natacha Linder
- Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
| | - Holger Russig
- Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
| | - Beat Thöny
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zürich, Switzerland
| | - Isabelle M. Mansuy
- Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
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16
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Jäggi L, Zurflüh MR, Schuler A, Ponzone A, Porta F, Fiori L, Giovannini M, Santer R, Hoffmann GF, Ibel H, Wendel U, Ballhausen D, Baumgartner MR, Blau N. Outcome and long-term follow-up of 36 patients with tetrahydrobiopterin deficiency. Mol Genet Metab 2008; 93:295-305. [PMID: 18060820 DOI: 10.1016/j.ymgme.2007.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 10/06/2007] [Accepted: 10/06/2007] [Indexed: 10/22/2022]
Abstract
We describe the treatment, the clinical, and biochemical findings and the outcome of 26 patients with 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency and 10 patients with dihydropteridine reductase (DHPR) deficiency. These are the two most common forms of the autosomal-recessively inherited tetrahydrobiopterin (BH4) deficiency. Time of diagnosis, dosage of BH4 and neurotransmitter precursors, folinic acid substitution, and levels of 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) in cerebrospinal fluid (CSF) are essential parameters in the follow-up of patients. Unfortunately, treatment protocols vary greatly among patients and clinical centers, and CSF investigations and outcome assessments are not always available. Seventeen patients with PTPS deficiency and four patients with DHPR deficiency were diagnosed within 2 months after birth. In 14 patients with PTPS deficiency (54%; 9 early and 5 late diagnosed) and 2 patients with DHPR deficiency (20%; all early diagnosed) no developmental delay is observed, while in 10 patients with PTPS deficiency (38%; 6 early and 4 late diagnosed) and 8 patients with DHPR deficiency (80%; 2 early and 6 late diagnosed) development was delayed. Two PTPS-deficient patients died in the newborn period. DHPR deficiency seems to be more severe than PTPS deficiency and it is clearly the onset of treatment that determines the outcome. Our data suggest that diagnosis within the first month of life is essential for a good outcome and that low CSF5 HIAA and HVA values in CSF could be an indicator for the ongoing developmental impairment
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Affiliation(s)
- Leandra Jäggi
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland
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17
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Echenne B, Roubertie A, Assmann B, Lutz T, Penzien JM, Thöny B, Blau N, Hoffmann GF. Sepiapterin reductase deficiency: clinical presentation and evaluation of long-term therapy. Pediatr Neurol 2006; 35:308-13. [PMID: 17074599 DOI: 10.1016/j.pediatrneurol.2006.05.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 03/17/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
Sepiapterin reductase deficiency has recently been recognized as a treatable, inborn error of pterin metabolism. This investigation is the first long-term clinical study demonstrating impressive positive, long-term effects of treatment in two cases of sepiapterin reductase deficiency after 2 and 5 years of treatment respectively. The two patients were not diagnosed before 7 and 13 years of age. These results highlight the importance of cerebrospinal fluid neurotransmitter investigations in childhood encephalopathy, in cases of unexplained early-onset neurologic handicap. Such a widened approach to the diagnostic efforts in early-onset encephalopathy with motor delay during childhood is important, as we have at our disposal a simple and effective treatment.
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18
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Ormazabal A, García Cazorla A, Pérez Dueñas B, Pineda M, Ruiz A, López Laso E, García Silva M, Carilho I, Barbot C, Cormand B, Ribases M, Moller L, Fernández Alvarez E, Campistol J, Artuch R. Utilidad del análisis del líquido cefalorraquídeo para el estudio de las deficiencias del metabolismo de neurotransmisores y pterinas y del transporte de glucosa y folato a través de la barrera hematoencefálica. Med Clin (Barc) 2006; 127:81-5. [PMID: 16827996 DOI: 10.1157/13090262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND OBJECTIVE In the last few years, it has been described inborn errors of neurotransmitter and pterin metabolism and defects in folate and glucose transport across blood brain barrier. All these defects are classified as rare diseases and needs cerebrospinal fluid (CSF) sample analysis for diagnosis. Our aim was to evaluate the results of the application of a CSF analysis protocol in a pediatric population from Spain and Portugal presenting with neurological disorders of unknown origin. PATIENTS AND METHOD We studied CSF samples from and 283 patients with neurological disorders of unknown origin and 127 controls. Neurotransmitters were analysed by HPLC with electrochemical detection, and pterins and 5-methyltetrahydrofolate were determined by HPLC with fluorescence detection. RESULTS We diagnosed 3 patients with tyrosine hidroxylase deficiency, 2 with dopa responsive dystonia, 14 with GTP-ciclohydrolase deficiency, 2 with glucose transport deficiency and 43 with cerebral folate deficiency. CONCLUSIONS This study allowed us to diagnose new patients, and more importantly, the establishment in all of them of a pharmacological or nutritional treatment. The most frequent defect found was CSF 5-methyltetrahydrofolate deficiency, which was present in different groups of patients.
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19
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Yang S, Lee YJ, Kim JM, Park S, Peris J, Laipis P, Park YS, Chung JH, Oh SP. A murine model for human sepiapterin-reductase deficiency. Am J Hum Genet 2006; 78:575-87. [PMID: 16532389 PMCID: PMC1424682 DOI: 10.1086/501372] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Accepted: 01/17/2006] [Indexed: 11/03/2022] Open
Abstract
Tetrahydrobiopterin (BH(4)) is an essential cofactor for several enzymes, including all three forms of nitric oxide synthases, the three aromatic hydroxylases, and glyceryl-ether mono-oxygenase. A proper level of BH(4) is, therefore, necessary for the metabolism of phenylalanine and the production of nitric oxide, catecholamines, and serotonin. BH(4) deficiency has been shown to be closely associated with diverse neurological psychiatric disorders. Sepiapterin reductase (SPR) is an enzyme that catalyzes the final step of BH(4) biosynthesis. Whereas the number of cases of neuropsychological disorders resulting from deficiencies of other catalytic enzymes involved in BH(4) biosynthesis and metabolism has been increasing, only a handful of cases of SPR deficiency have been reported, and the role of SPR in BH(4) biosynthesis in vivo has been poorly understood. Here, we report that mice deficient in the Spr gene (Spr(-/-)) display disturbed pterin profiles and greatly diminished levels of dopamine, norepinephrine, and serotonin, indicating that SPR is essential for homeostasis of BH(4) and for the normal functions of BH(4)-dependent enzymes. The Spr(-/-) mice exhibit phenylketonuria, dwarfism, and impaired body movement. Oral supplementation of BH(4) and neurotransmitter precursors completely rescued dwarfism and phenylalanine metabolism. The biochemical and behavioral characteristics of Spr(-/-) mice share striking similarities with the symptoms observed in SPR-deficient patients. This Spr mutant strain of mice will be an invaluable resource to elucidate many important issues regarding SPR and BH(4) deficiencies.
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Affiliation(s)
- Seungkyoung Yang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Young Jae Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Jin-Man Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Sean Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Joanna Peris
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Philip Laipis
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Young Shik Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - Jae Hoon Chung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
| | - S. Paul Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, and Department of Pathology, Chungnam National University School of Medicine, Daejeon, South Korea; Departments of Physiology and Functional Genomics and Biochemistry and Molecular Biology, University of Florida College of Medicine, and Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville; and School of Biotechnology and Biomedical Science, Inje University, Kimhae, South Korea
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20
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Sajadi A, Bauer M, Thöny B, Aebischer P. Long-term glial cell line-derived neurotrophic factor overexpression in the intact nigrostriatal system in rats leads to a decrease of dopamine and increase of tetrahydrobiopterin production. J Neurochem 2005; 93:1482-6. [PMID: 15935064 DOI: 10.1111/j.1471-4159.2005.03139.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Parkinson's disease (PD) is characterized by the progressive degeneration of the nigrostriatal dopaminergic system. Brain delivery of glial cell line-derived neurotrophic factor (GDNF) has been shown to protect and restore the dopaminergic pathway in various animal models of PD. However, GDNF overexpression in the dopaminergic pathway leads to a time-dependent down-regulation of tyrosine hydroxylase (TH), a key enzyme in dopamine synthesis. In order to elucidate GDNF-mediated biochemical effects on dopaminergic neurons, we overexpressed GDNF in the intact rat striatum using a lentiviral vector-mediated gene transfer technique. Long-term GDNF overexpression led to increased GTP cyclohydrolase I (GTPCH I) activity and tetrahydrobiopterin (BH4) levels. Further, we observed a down-regulation of TH enzyme activity in morphologically intact striatal dopaminergic nerve terminals, as well as a significant decrease of dopamine levels in striatal tissue samples. These results indicate that long-term GDNF delivery is a major factor affecting dopamine biosynthesis via a direct or indirect modulation of TH and GTPCH I and further underscore the importance of assessing both GDNF dose and delivery duration prior to clinical application in order to circumvent potentially adverse pharmacological effects on the biosynthesis of dopamine.
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Affiliation(s)
- Ali Sajadi
- Ecole Polytechnique Fédérale de Lausanne, EPFL, Integrative Biosciences Institute, Lausanne, Switzerland
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Ponzone A, Spada M, Ferraris S, Dianzani I, de Sanctis L. Dihydropteridine reductase deficiency in man: from biology to treatment. Med Res Rev 2004; 24:127-50. [PMID: 14705166 DOI: 10.1002/med.10055] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In 1975, dihydropteridine reductase (DHPR) deficiency was first recognized as a cause of tetrahydrobiopterin (BH(4)) deficiency, leading to hyperphenylalaninemia (HPA) and impaired biogenic amine deficiency. So far, more than 150 patients scattered worldwide have been reported and major progresses have been made in the understanding of physiopathology, screening, diagnosis, treatment, and molecular genetics of this inherited disease. Present knowledge on different aspects of DHPR deficiency, largely derived from authors' personal experience, is traced in this article.
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Blau N, Bonafé L, Krägeloh-Mann I, Thöny B, Kierat L, Häusler M, Ramaekers V. Cerebrospinal fluid pterins and folates in Aicardi-Goutières syndrome: a new phenotype. Neurology 2003; 61:642-7. [PMID: 12963755 DOI: 10.1212/01.wnl.0000082726.08631.e7] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To describe three unrelated children with a distinctive variant of Aicardi-Goutières syndrome (AGS) characterized by microcephaly, severe mental and motor retardation, dyskinesia or spasticity, and occasional seizures. RESULTS Neuroimaging showed bilateral calcification of basal ganglia and white matter. CSF glucose, protein, cell count, and interferon alpha were normal. Abnormal CSF findings included extremely high neopterin (293 to 814 nmol/L; normal 12 to 30 nmol/L) and biopterin (226 to 416 nmol/L; normal 15 to 40 nmol/L) combined with lowered 5-methyltetrahydrofolate (23 to 48 nmol/L; normal 64 to 182 nmol/L) concentrations in two patients. The absence of pleocytosis and normal CSF interferon alpha was a characteristic finding compared to the classic AGS syndrome. Genetic and enzymatic tests excluded disorders of tetrahydrobiopterin metabolism, including mutation analysis of GTP cyclohydrolase feed-back regulatory protein. CSF investigations in three patients with classic AGS also showed increased pterins and partially lowered folate levels. CONCLUSIONS Intrathecal overproduction of pterins is the first biochemical abnormality identified in patients with AGS variants. Long-term substitution with folinic acid (2-4 mg/kg/day) resulted in substantial clinical recovery with normalization of CSF folates and pterins in one patient and clinical improvement in another. The underlying defect remains unknown.
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Affiliation(s)
- N Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich, Switzerland.
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Elzaouk L, Leimbacher W, Turri M, Ledermann B, Burki K, Blau N, Thony B. Dwarfism and low insulin-like growth factor-1 due to dopamine depletion in Pts-/- mice rescued by feeding neurotransmitter precursors and H4-biopterin. J Biol Chem 2003; 278:28303-11. [PMID: 12734191 DOI: 10.1074/jbc.m303986200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The tetrahydrobiopterin (BH4) cofactor is essential for the biosynthesis of catecholamines and serotonin and for nitric-oxide synthase (NOS). Alterations in BH4 metabolism are observed in various neurological and psychiatric diseases, and mutations in one of the human metabolic genes causes hyperphenylalaninemia and/or monoamine neurotransmitter deficiency. We report on a knockout mouse for the Pts gene, which codes for a BH4-biosynthetic enzyme. Homozygous Pts-/- mice developed with normal morphology but died after birth. Upon daily oral administration of BH4 and neurotransmitter precursors the Pts-/- mice eventually survived. However, at sexual maturity (6 weeks) the mice had only one-third of the normal body weight and were sexually immature. Biochemical analysis revealed no hyperphenylalaninemia, normal brain NOS activity, and almost normal serotonin levels, but brain dopamine was 3% of normal. Low dopamine leads to impaired food consumption as reflected by the severe growth deficiency and a 7-fold reduced serum insulin-like growth factor-1 (IGF-1). This is the first link shown between 6-pyruvoyltetrahydropterin synthase- or BH4-biosynthetic activity and IGF-1.
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Affiliation(s)
- Lina Elzaouk
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, Division of Animal Facility, University of Zürich, Steinwiesstrasse 75, CH-8032 Zurich, Switzerland
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Blau N, Bonafé L, Thöny B. Tetrahydrobiopterin deficiencies without hyperphenylalaninemia: diagnosis and genetics of dopa-responsive dystonia and sepiapterin reductase deficiency. Mol Genet Metab 2001; 74:172-85. [PMID: 11592814 DOI: 10.1006/mgme.2001.3213] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
DOPA responsive dystonia (DRD) and sepiapterin reductase (SR) deficiency are inherited disorders of tetrahydrobiopterin (BH4) metabolism characterized by the signs and symptoms related to monoamine neurotransmitter deficiency. In contrast to classical forms of BH4 deficiency DRD and SR deficiency present without hyperphenylalaninemia and thus cannot be detected by the neonatal screening for phenylketonuria (PKU). While DRD is mostly caused by autosomal dominant mutations in the GTP cyclohydrolase I gene (GCH1), SR deficiency is an autosomal recessive disease. The most important biochemical investigations for the diagnosis of these neurological diseases includes CSF investigations for neurotransmitter metabolites and pterins as well as neopterin and biopterin production in cytokine-stimulated fibroblasts. Discovery of SR deficiency opened new insights into alternative pathways of the cofactor BH4 via carbonyl, aldose, and dihydrofolate reductases. As a consequence of the low dihydrofolate reductase activity in the brain, dihydrobiopterin intermediate accumulates and inhibits tyrosine and tryptophan hydroxylases and uncouples nitric oxide synthase (nNOS), leading to neurotransmitter deficiency and possibly also to neuronal cell death.
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Affiliation(s)
- N Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Steinwiesstrasse 75, Zurich, 8032, Switzerland.
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Bonafé L, Thöny B, Penzien JM, Czarnecki B, Blau N. Mutations in the sepiapterin reductase gene cause a novel tetrahydrobiopterin-dependent monoamine-neurotransmitter deficiency without hyperphenylalaninemia. Am J Hum Genet 2001; 69:269-77. [PMID: 11443547 PMCID: PMC1235302 DOI: 10.1086/321970] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2001] [Accepted: 05/31/2001] [Indexed: 11/03/2022] Open
Abstract
Classic tetrahydrobiopterin (BH(4)) deficiencies are characterized by hyperphenylalaninemia and deficiency of monoamine neurotransmitters. In this article, we report two patients with progressive psychomotor retardation, dystonia, severe dopamine and serotonin deficiencies (low levels of 5-hydroxyindoleacetic and homovanillic acids), and abnormal pterin pattern (high levels of biopterin and dihydrobiopterin) in cerebrospinal fluid. Furthermore, they presented with normal urinary pterins and without hyperphenylalaninemia. Investigation of skin fibroblasts revealed inactive sepiapterin reductase (SR), the enzyme catalyzing the final two-step reaction in the biosynthesis of BH(4). Mutations in the SPR gene were detected in both patients and their family members. One patient was homozygous for a TC-->CT dinucleotide exchange, predicting a truncated SR (Q119X). The other patient was a compound heterozygote for a genomic 5-bp deletion (1397-1401delAGAAC) resulting in abolished SPR-gene expression and an A-->G transition leading to an R150G amino acid substitution and to inactive SR as confirmed by recombinant expression. The absence of hyperphenylalaninemia and the presence of normal urinary pterin metabolites and of normal SR-like activity in red blood cells may be explained by alternative pathways for the final two-step reaction of BH(4) biosynthesis in peripheral and neuronal tissues. We propose that, for the biosynthesis of BH(4) in peripheral tissues, SR activity may be substituted by aldose reductase (AR), carbonyl reductase (CR), and dihydrofolate reductase, whereas, in the brain, only AR and CR are fully present. Thus, autosomal recessive SR deficiency leads to BH(4) and to neurotransmitter deficiencies without hyperphenylalaninemia and may not be detected by neonatal screening for phenylketonuria.
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Affiliation(s)
- Luisa Bonafé
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich; Children’s Hospital, Augsburg; and Children’s Hospital Königsborn, Unna, Germany
| | - Beat Thöny
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich; Children’s Hospital, Augsburg; and Children’s Hospital Königsborn, Unna, Germany
| | - Johann M. Penzien
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich; Children’s Hospital, Augsburg; and Children’s Hospital Königsborn, Unna, Germany
| | - Barbara Czarnecki
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich; Children’s Hospital, Augsburg; and Children’s Hospital Königsborn, Unna, Germany
| | - Nenad Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich; Children’s Hospital, Augsburg; and Children’s Hospital Königsborn, Unna, Germany
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Spaapen LJ, Bakker JA, Velter C, Loots W, Rubio-Gozalbo ME, Forget PP, Dorland L, De Koning TJ, Poll-The BT, Ploos van Amstel HK, Bekhof J, Blau N, Duran M, Rubio-Gonzalbo ME. Tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency in Dutch neonates. J Inherit Metab Dis 2001; 24:352-8. [PMID: 11486900 DOI: 10.1023/a:1010596317296] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Four neonates with a positive phenylalanine screening test (Phe concentrations between 258 and 1250 micromol/L) were investigated further to differentiate between phenylalanine hydroxylase (PAH) deficiency and variant hyperphenylalaninaemia (HPA) forms. In patients 1 and 2 a tetrahydrobiopterin (BH4) load caused a significant decrease of the plasma Phe levels. A combined phenylalanine/BH4 loading test was performed in patients 2, 3 and 4. In the latter two patients, plasma Phe concentrations completely normalized within 8 h after the BH4 load (20 mg/kg). Basal urinary pterins were normal in all four patients. The activity of dihydropteridine reductase (DHPR) was normal in patients 1, 2 and 3 and 50% of control values in patient 4 (not in the range of DHPR-deficient patients). In patient 3 a subsequent phenylalanine loading test with concomitant analysis of plasma biopterins revealed a normal increase of biopterin, excluding a BH4 biosynthesis defect. Pterins and neurotransmitter metabolites in CSF of patients 1, 3 and 4 were normal. DNA mutations detected in the PAH gene of patients 1-4 were A313T, and L367fsinsC; V190A and R243X; A300S and A403V; R241C and A403V. The results are suggestive for mutant PAH enzymes with decreased affinity for the cofactor BH4.
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Affiliation(s)
- L J Spaapen
- Department of Biochemical Genetics, Stichting Klinische Genetica Zuid-Oost Nederland, Maastricht.
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Ramaekers VT, Senderek J, Häusler M, Häring M, Abeling N, Zerres K, Bergmann C, Heimann G, Blau N. A novel neurodevelopmental syndrome responsive to 5-hydroxytryptophan and carbidopa. Mol Genet Metab 2001; 73:179-87. [PMID: 11386854 DOI: 10.1006/mgme.2001.3187] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tryptophan hydroxylase (TPH; EC 1.14.16.4) catalyzes the first rate-limiting step of serotonin biosynthesis by converting l-tryptophan to 5-hydroxytryptophan. Serotonin controls multiple vegetative functions and modulates sensory and alpha-motor neurons at the spinal level. We report on five boys with floppiness in infancy followed by motor delay, development of a hypotonic-ataxic syndrome, learning disability, and short attention span. Cerebrospinal fluid (CSF) analysis showed a 51 to 65% reduction of the serotonin end-metabolite 5-hydroxyindoleacetic acid (5HIAA) compared to age-matched median values. In one out of five patients a low CSF 5-methyltetrahydrofolate (MTHF) was present probably due to the common C677T heterozygous mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. Baseline 24-h urinary excretion showed diminished 5HIAA values, not changing after a single oral load with l-tryptophan (50-70 mg/kg), but normalizing after 5-hydroxytryptophan administration (1 mg/kg). Treatment with 5-hydroxytryptophan (4-6 mg/kg) and carbidopa (0.5-1.0 mg/kg) resulted in clinical amelioration and normalization of 5HIAA levels in CSF and urine. In the patient with additional MTHFR heterozygosity, a heterozygous missense mutation within exon 6 (G529A) of the TPH gene caused an exchange of valine by isoleucine at codon 177 (V177I). This has been interpreted as a rare DNA variant because the pedigree analysis did not provide any genotype-phenotype correlation. In the other four patients the TPH gene analysis was normal. In conclusion, this new neurodevelopmental syndrome responsive to treatment with 5-hydroxytryptophan and carbidopa might result from an overall reduced capacity of serotonin production due to a TPH gene regulatory defect, unknown factors inactivating the TPH enzyme, or selective loss of serotonergic neurons.
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Affiliation(s)
- V T Ramaekers
- Division of Paediatric Neurology, Department of Pediatrics, University Hospital Aachen, 52074 Aachen, Germany.
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Abstract
Diagnostic testing for genetically determined metabolic disease has for many years relied heavily on the use of generalized screening tests that analyze groups of related compounds in easily accessible peripheral fluids such as plasma and urine. Organic acid profiles in urine and amino acid analysis in plasma are two of the most commonly requested tests; these, together with other protocols that examine peripheral fluids, have been and continue to be invaluable tools. There is, however, an emerging realization that many metabolic encephalopathies do not arise secondary to peripheral metabolic changes but rather have their origins within the central nervous system. In these cases, testing of peripheral fluids might be uninformative. This review is designed to examine the role of cerebrospinal fluid analyses in the investigation of infants and children with undefined encephalopathies. The aims are to review the conditions in which measurement of metabolites in cerebrospinal fluid is critical if a diagnosis is to be made, and to emphasize that considerable forethought is often required to ensure correct collection and handling of cerebrospinal fluid. Thus, fidelity of the diagnostic analytic procedures is maintained. This review will help the pediatric neurologist establish practical diagnostic guidelines that in turn will help in the recognition of recently described conditions. Those conditions can, in general, be identified only after specialized cerebrospinal fluid testing.
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Affiliation(s)
- K Hyland
- Department of Neurochemistry, Institute of Metabolic Disease, Baylor University Medical Center, Dallas, TX 75226, USA.
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Abstract
The purpose of the current review is to present a brief background examining the mechanisms controlling synthesis, storage, release and action of the biogenic amine neurotransmitters and to provide examples of newly defined conditions that expand our awareness of the diversity and complexity of the inherited diseases that affect these important regulators of central and peripheral homeostasis.
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Affiliation(s)
- K Hyland
- Institute of Metabolic Disease, Baylor University Medical Center, Dallas, TX 75226, USA.
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