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Brenner M, Zink C, Witzinger L, Keller A, Hadamek K, Bothe S, Neuenschwander M, Villmann C, von Kries JP, Schindelin H, Jeanclos E, Gohla A. 7,8-Dihydroxyflavone is a direct inhibitor of human and murine pyridoxal phosphatase. eLife 2024; 13:RP93094. [PMID: 38856179 PMCID: PMC11164532 DOI: 10.7554/elife.93094] [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] [Indexed: 06/11/2024] Open
Abstract
Vitamin B6 deficiency has been linked to cognitive impairment in human brain disorders for decades. Still, the molecular mechanisms linking vitamin B6 to these pathologies remain poorly understood, and whether vitamin B6 supplementation improves cognition is unclear as well. Pyridoxal 5'-phosphate phosphatase (PDXP), an enzyme that controls levels of pyridoxal 5'-phosphate (PLP), the co-enzymatically active form of vitamin B6, may represent an alternative therapeutic entry point into vitamin B6-associated pathologies. However, pharmacological PDXP inhibitors to test this concept are lacking. We now identify a PDXP and age-dependent decline of PLP levels in the murine hippocampus that provides a rationale for the development of PDXP inhibitors. Using a combination of small-molecule screening, protein crystallography, and biolayer interferometry, we discover, visualize, and analyze 7,8-dihydroxyflavone (7,8-DHF) as a direct and potent PDXP inhibitor. 7,8-DHF binds and reversibly inhibits PDXP with low micromolar affinity and sub-micromolar potency. In mouse hippocampal neurons, 7,8-DHF increases PLP in a PDXP-dependent manner. These findings validate PDXP as a druggable target. Of note, 7,8-DHF is a well-studied molecule in brain disorder models, although its mechanism of action is actively debated. Our discovery of 7,8-DHF as a PDXP inhibitor offers novel mechanistic insights into the controversy surrounding 7,8-DHF-mediated effects in the brain.
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Affiliation(s)
- Marian Brenner
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Christoph Zink
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Linda Witzinger
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Angelika Keller
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Kerstin Hadamek
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Sebastian Bothe
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of WürzburgWürzburgGermany
| | | | - Carmen Villmann
- Institute of Clinical Neurobiology, University Hospital, University of WürzburgWürzburgGermany
| | | | - Hermann Schindelin
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of WürzburgWürzburgGermany
| | - Elisabeth Jeanclos
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
| | - Antje Gohla
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburgGermany
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2
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Thompson MD, Knaus A. Rare Genetic Developmental Disabilities: Mabry Syndrome (MIM 239300) Index Cases and Glycophosphatidylinositol (GPI) Disorders. Genes (Basel) 2024; 15:619. [PMID: 38790248 PMCID: PMC11121671 DOI: 10.3390/genes15050619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The case report by Mabry et al. (1970) of a family with four children with elevated tissue non-specific alkaline phosphatase, seizures and profound developmental disability, became the basis for phenotyping children with the features that became known as Mabry syndrome. Aside from improvements in the services available to patients and families, however, the diagnosis and treatment of this, and many other developmental disabilities, did not change significantly until the advent of massively parallel sequencing. As more patients with features of the Mabry syndrome were identified, exome and genome sequencing were used to identify the glycophosphatidylinositol (GPI) biosynthesis disorders (GPIBDs) as a group of congenital disorders of glycosylation (CDG). Biallelic variants of the phosphatidylinositol glycan (PIG) biosynthesis, type V (PIGV) gene identified in Mabry syndrome became evidence of the first in a phenotypic series that is numbered HPMRS1-6 in the order of discovery. HPMRS1 [MIM: 239300] is the phenotype resulting from inheritance of biallelic PIGV variants. Similarly, HPMRS2 (MIM 614749), HPMRS5 (MIM 616025) and HPMRS6 (MIM 616809) result from disruption of the PIGO, PIGW and PIGY genes expressed in the endoplasmic reticulum. By contrast, HPMRS3 (MIM 614207) and HPMRS4 (MIM 615716) result from disruption of post attachment to proteins PGAP2 (HPMRS3) and PGAP3 (HPMRS4). The GPI biosynthesis disorders (GPIBDs) are currently numbered GPIBD1-21. Working with Dr. Mabry, in 2020, we were able to use improved laboratory diagnostics to complete the molecular diagnosis of patients he had originally described in 1970. We identified biallelic variants of the PGAP2 gene in the first reported HPMRS patients. We discuss the longevity of the Mabry syndrome index patients in the context of the utility of pyridoxine treatment of seizures and evidence for putative glycolipid storage in patients with HPMRS3. From the perspective of the laboratory innovations made that enabled the identification of the HPMRS phenotype in Dr. Mabry's patients, the need for treatment innovations that will benefit patients and families affected by developmental disabilities is clear.
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Affiliation(s)
- Miles D. Thompson
- Krembil Brain Institute, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany;
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3
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Korasick DA, Buckley DP, Palpacelli A, Cursio I, Cesaroni E, Cheng J, Tanner JJ. Biochemical, structural, and computational analyses of two new clinically identified missense mutations of ALDH7A1. Chem Biol Interact 2024; 394:110993. [PMID: 38604394 PMCID: PMC11073572 DOI: 10.1016/j.cbi.2024.110993] [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: 02/27/2024] [Revised: 03/30/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
Aldehyde dehydrogenase 7A1 (ALDH7A1) catalyzes a step of lysine catabolism. Certain missense mutations in the ALDH7A1 gene cause pyridoxine dependent epilepsy (PDE), a rare autosomal neurometabolic disorder with recessive inheritance that affects almost 1:65,000 live births and is classically characterized by recurrent seizures from the neonatal period. We report a biochemical, structural, and computational study of two novel ALDH7A1 missense mutations that were identified in a child with rare recurrent seizures from the third month of life. The mutations affect two residues in the oligomer interfaces of ALDH7A1, Arg134 and Arg441 (Arg162 and Arg469 in the HGVS nomenclature). The corresponding enzyme variants R134S and R441C (p.Arg162Ser and p.Arg469Cys in the HGVS nomenclature) were expressed in Escherichia coli and purified. R134S and R441C have 10,000- and 50-fold lower catalytic efficiency than wild-type ALDH7A1, respectively. Sedimentation velocity analytical ultracentrifugation shows that R134S is defective in tetramerization, remaining locked in a dimeric state even in the presence of the tetramer-inducing coenzyme NAD+. Because the tetramer is the active form of ALDH7A1, the defect in oligomerization explains the very low catalytic activity of R134S. In contrast, R441C exhibits wild-type oligomerization behavior, and the 2.0 Å resolution crystal structure of R441C complexed with NAD+ revealed no obvious structural perturbations when compared to the wild-type enzyme structure. Molecular dynamics simulations suggest that the mutation of Arg441 to Cys may increase intersubunit ion pairs and alter the dynamics of the active site gate. Our biochemical, structural, and computational data on two novel clinical variants of ALDH7A1 add to the complexity of the molecular determinants underlying pyridoxine dependent epilepsy.
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Affiliation(s)
- David A Korasick
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, United States
| | - David P Buckley
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, United States
| | | | - Ida Cursio
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, United Hospitals of Marche, Ancona, Italy
| | - Elisabetta Cesaroni
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, United Hospitals of Marche, Ancona, Italy
| | - Jianlin Cheng
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, 65211, United States
| | - John J Tanner
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, United States; Department of Chemistry, University of Missouri, Columbia, MO, 65211, United States.
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4
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Cruz Marino T, Leblanc J, Pratte A, Tardif J, Thomas MJ, Fortin CA, Girard L, Bouchard L. Portrait of autosomal recessive diseases in the French-Canadian founder population of Saguenay-Lac-Saint-Jean. Am J Med Genet A 2023; 191:1145-1163. [PMID: 36786328 DOI: 10.1002/ajmg.a.63147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/16/2023] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
The population of the Saguenay-Lac-Saint-Jean (SLSJ) region, located in the province of Quebec, Canada, is recognized as a founder population, where some rare autosomal recessive diseases show a high prevalence. Through the clinical and molecular study of 82 affected individuals from 60 families, this study outlines 12 diseases identified as recurrent in SLSJ. Their carrier frequency was estimated with the contribution of 1059 healthy individuals, increasing the number of autosomal recessive diseases with known carrier frequency in this region from 14 to 25. We review the main clinical and molecular features previously reported for these disorders. Five of the studied diseases have a potential lethal effect and three are associated with intellectual deficiency. Therefore, we believe that the provincial program for carrier screening should be extended to include these eight disorders. The high-carrier frequency, together with the absence of consanguinity in most of these unrelated families, suggest a founder effect and genetic drift for the 12 recurrent variants. We recommend further studies to validate this hypothesis, as well as to extend the present study to other regions in the province of Quebec, since some of these disorders could also be present in other French-Canadian families.
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Affiliation(s)
- Tania Cruz Marino
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Josianne Leblanc
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Annabelle Pratte
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Jessica Tardif
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | | | - Carol-Ann Fortin
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
| | - Lysanne Girard
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
| | - Luigi Bouchard
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada.,Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
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5
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Zagubnaya OA, Nartsissov YR. MOLECULAR MECHANISMS UNDERLYING THERAPEUTIC ACTION OF VITAMIN B6. PHARMACY & PHARMACOLOGY 2023. [DOI: 10.19163/2307-9266-2022-10-6-500-514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The aim of the study was to analyze the molecular mechanisms that determine the possibility of using vitamin B6 in clinical practice for the correction of various pathological conditions.Materials and methods. Information retrieval (Scopus, PubMed) and library (eLibrary) databases were used as research tools. In some cases, the ResearchGate application was used for a semantic search. The analysis and generalization of the scientific literature on the topic of research, covering the period from 1989 to the present, has been carried out in the work.Results. It has been shown that all chemical forms of vitamin B6 are able to penetrate the membranes of most cells by free diffusion, while forming phosphorylated forms inside. Pyridoxal phosphate is a biologically important metabolite that is directly involved as a cofactor in a variety of intracellular reactions. Requirements for this cofactor depend on the age, sex and condition of the patient. Pregnancy and lactation play a special role in the consumption of vitamin B6. In most cases, a balanced diet will provide an acceptable level of this vitamin. At the same time, its deficiency leads to the development of a number of pathological conditions, including neurodegenerative diseases, inflammations and diabetes. Negative manifestations from the central nervous system are also possible with an excessive consumption of B6.Conclusion. Replenishment of the vitamin B6 level in case of its identified deficiency is a necessary condition for the successful treatment of the central nervous system diseases, diabetes and correction of patients’ immune status. At the same time, it is necessary to observe a balanced intake of this cofactor in order to avoid negative effects on metabolism in case of its excess.
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Affiliation(s)
- O. A. Zagubnaya
- Institute of Cytochemistry and Molecular Pharmacology;
Biomedical Research Group, BiDiPharma GmbH
| | - Y. R. Nartsissov
- Institute of Cytochemistry and Molecular Pharmacology;
Biomedical Research Group, BiDiPharma GmbH
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6
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Bayat A, Aledo-Serrano A, Gil-Nagel A, Korff CM, Thomas A, Boßelmann C, Weber Y, Gardella E, Lund AM, de Sain-van der Velden MGM, Møller RS. Pyridoxine or pyridoxal-5-phosphate treatment for seizures in glycosylphosphatidylinositol deficiency: A cohort study. Dev Med Child Neurol 2022; 64:789-798. [PMID: 35080266 DOI: 10.1111/dmcn.15142] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/20/2021] [Accepted: 11/24/2021] [Indexed: 01/06/2023]
Abstract
AIM To investigate the short-term efficacy and safety of high-dose pyridoxine and pyridoxal 5-phosphate (P5P) in the treatment of inherited glycosylphosphatidylinositol (GPI) deficiency-associated epilepsy. METHOD Participants with genetically confirmed GPI deficiency were treated with oral pyridoxine or P5P as compassionate use in an agreed-upon clinical regimen. Pyridoxine (20-30 mg/kg/day) was used for 3 months. Baseline evaluation included 4 weeks of prospective seizure data and one video electroencephalogram (EEG). Seizure frequency was captured daily. The EEG was repeated after reaching maximum dosage of pyridoxine. Pyridoxine was switched to P5P (20-30 mg/kg/day) if seizure burden was unchanged after 3 months' treatment. Another EEG was done after 3 months of P5P treatment. Primary outcome measures were reduction of seizure frequency and EEG improvements. RESULTS Seven participants (one female, six males; age range 5-23 year; mean age 11 years 10 months, SD 5 year 2 months) were included. The genetic causes of inherited GPI deficiency were phosphatidylinositol N-acetylglucosaminyltransferase subunit A/T/V deficiency. All had drug-resistant epilepsy and neurodevelopmental impairment. We observed more than 50% seizure frequency reduction in 2 out of 7 and less than 50% reduction in another 3 out of 7 participants. No participants reached seizure freedom. No remarkable changes in electrophysiological findings were observed in 6 out of 7 participants treated with pyridoxine or P5P when comparing the baseline and follow-up EEGs. INTERPRETATION We observed no long-lasting electrophysiological improvements during treatment but pyridoxine may reduce seizure frequency or burden in inherited GPI deficiency. WHAT THIS PAPER ADDS Inherited glycosylphosphatidylinositol (GPI) deficiency often causes early-onset and drug-resistant epilepsy. Vitamin B6 is a potential disease-specific treatment; however, efficacy and safety are ill-defined. Pyridoxine may reduce seizure frequency or burden in inherited GPI deficiency. Pyridoxine and P5P could prove to be a useful treatment in some individuals with inherited GPI deficiency and epilepsy.
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Affiliation(s)
- Allan Bayat
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark.,Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Angel Aledo-Serrano
- Epilepsy Program, Department of Neurology, Ruber International Hospital, Madrid, Spain
| | - Antonio Gil-Nagel
- Epilepsy Program, Department of Neurology, Ruber International Hospital, Madrid, Spain
| | - Christian M Korff
- Pediatric Neurology Unit, Department of the Woman, Child, and Adolescent, University Hospitals Geneva, Geneva, Switzerland
| | - Ashley Thomas
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Christian Boßelmann
- Department of Neurology and Epileptology, Hertie-Institute for Clinical Brain Research, Eberhard-Karls University of Tübingen, Tübingen, Germany
| | - Yvonne Weber
- Department of Neurology and Epileptology, Hertie-Institute for Clinical Brain Research, Eberhard-Karls University of Tübingen, Tübingen, Germany.,Department of Epileptology and Neurology, University of Aachen, Aachen, Germany
| | - Elena Gardella
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark.,Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Allan M Lund
- Department of Pediatrics, Centre for Inherited Metabolic Diseases, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Genetics, Centre for Inherited Metabolic Diseases, Rigshospitalet, Copenhagen, Denmark
| | | | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark.,Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
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7
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Bayat A, de Valles-Ibáñez G, Pendziwiat M, Knaus A, Alt K, Biamino E, Bley A, Calvert S, Carney P, Caro-Llopis A, Ceulemans B, Cousin J, Davis S, des Portes V, Edery P, England E, Ferreira C, Freeman J, Gener B, Gorce M, Heron D, Hildebrand MS, Jezela-Stanek A, Jouk PS, Keren B, Kloth K, Kluger G, Kuhn M, Lemke JR, Li H, Martinez F, Maxton C, Mefford HC, Merla G, Mierzewska H, Muir A, Monfort S, Nicolai J, Norman J, O'Grady G, Oleksy B, Orellana C, Orec LE, Peinhardt C, Pronicka E, Rosello M, Santos-Simarro F, Schwaibold EMC, Stegmann APA, Stumpel CT, Szczepanik E, Terczyńska I, Thevenon J, Tzschach A, Van Bogaert P, Vittorini R, Walsh S, Weckhuysen S, Weissman B, Wolfe L, Reymond A, De Nittis P, Poduri A, Olson H, Striano P, Lesca G, Scheffer IE, Møller RS, Sadleir LG. PIGN encephalopathy: Characterizing the epileptology. Epilepsia 2022; 63:974-991. [PMID: 35179230 DOI: 10.1111/epi.17173] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Epilepsy is common in patients with PIGN diseases due to biallelic variants; however, limited epilepsy phenotyping data have been reported. We describe the epileptology of PIGN encephalopathy. METHODS We recruited patients with epilepsy due to biallelic PIGN variants and obtained clinical data regarding age at seizure onset/offset and semiology, development, medical history, examination, electroencephalogram, neuroimaging, and treatment. Seizure and epilepsy types were classified. RESULTS Twenty six patients (13 female) from 26 families were identified, with mean age 7 years (range = 1 month to 21 years; three deceased). Abnormal development at seizure onset was present in 25 of 26. Developmental outcome was most frequently profound (14/26) or severe (11/26). Patients presented with focal motor (12/26), unknown onset motor (5/26), focal impaired awareness (1/26), absence (2/26), myoclonic (2/26), myoclonic-atonic (1/26), and generalized tonic-clonic (2/26) seizures. Twenty of 26 were classified as developmental and epileptic encephalopathy (DEE): 55% (11/20) focal DEE, 30% (6/20) generalized DEE, and 15% (3/20) combined DEE. Six had intellectual disability and epilepsy (ID+E): two generalized and four focal epilepsy. Mean age at seizure onset was 13 months (birth to 10 years), with a lower mean onset in DEE (7 months) compared with ID+E (33 months). Patients with DEE had drug-resistant epilepsy, compared to 4/6 ID+E patients, who were seizure-free. Hyperkinetic movement disorder occurred in 13 of 26 patients. Twenty-seven of 34 variants were novel. Variants were truncating (n = 7), intronic and predicted to affect splicing (n = 7), and missense or inframe indels (n = 20, of which 11 were predicted to affect splicing). Seven variants were recurrent, including p.Leu311Trp in 10 unrelated patients, nine with generalized seizures, accounting for nine of the 11 patients in this cohort with generalized seizures. SIGNIFICANCE PIGN encephalopathy is a complex autosomal recessive disorder associated with a wide spectrum of epilepsy phenotypes, typically with substantial profound to severe developmental impairment.
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Affiliation(s)
- Allan Bayat
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.,Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
| | | | - Manuela Pendziwiat
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian Albrecht University, Kiel, Germany.,Institute of Clinical Molecular Biology, Christian Albrecht University of Kiel, Kiel, Germany
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rhenish Friedrich Wilhelm University of Bonn, Bonn, Germany
| | | | - Elisa Biamino
- Department of Pediatrics, Regina Margherita Children's Hospital, Turin, Italy
| | - Annette Bley
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sophie Calvert
- Department of Neurosciences, Queensland Children's Hospital, South Brisbane, Queensland, Australia
| | - Patrick Carney
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | | | - Berten Ceulemans
- Department of Pediatric Neurology, Antwerp University Hospital, Edegem, Belgium
| | - Janice Cousin
- Section of Human Biochemical Genetics, National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Suzanne Davis
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | | | - Patrick Edery
- Department of Medical Genetics, University Hospital of Lyon, Lyon, France
| | - Eleina England
- Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts, USA
| | - Carlos Ferreira
- National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Jeremy Freeman
- Royal Children's Hospital, Parkville, Victoria, Australia.,Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Blanca Gener
- Department of Genetics, Cruces University Hospital, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | | | - Delphine Heron
- Department of Genetics, Intellectual Disability and Autism Clinical Research Group, Pierre and Marie Curie University, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | - Michael S Hildebrand
- Royal Children's Hospital, Florey institute and Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Epilepsy Research Centre, Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Victoria, Australia
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - Pierre-Simon Jouk
- Inserm U1209, Grenoble Alpes University Hospital Center, University of Grenoble Alpes, Grenoble, France
| | - Boris Keren
- Department of Genetics, Intellectual Disability and Autism Clinical Research Group, Pierre and Marie Curie University, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | - Katja Kloth
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | | | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany.,Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
| | - Hong Li
- Emory University School of Medicine, Atlanta, Georgia, USA
| | - Francisco Martinez
- Genomics Unit, University and Polytechnic Hospital La Fe, Valencia, Spain
| | | | - Heather C Mefford
- Center for Pediatric Neurological Disease Research, Department of Cell and Molecular Biology, St, Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Giuseppe Merla
- Department of Pediatrics, Regina Margherita Children's Hospital, Turin, Italy
| | - Hanna Mierzewska
- Department of Mother and Child Neurology, Institute of Mother and Child, Warsaw, Poland
| | - Alison Muir
- Center for Pediatric Neurological Disease Research, Department of Cell and Molecular Biology, St, Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Sandra Monfort
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Joost Nicolai
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands
| | | | - Gina O'Grady
- Starship Children's Hospital, Auckland, New Zealand
| | - Barbara Oleksy
- Department of Child and Adolescent Neurology, Institute of Mother and Child, Warsaw, Poland
| | - Carmen Orellana
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Laura Elena Orec
- Center for Child and Adolescent Medicine, Pediatric Neurology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Ewa Pronicka
- Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland
| | - Monica Rosello
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands
| | | | | | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Constance T Stumpel
- Department of Clinical Genetics and School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Elzbieta Szczepanik
- Department of Child and Adolescent Neurology, Institute of Mother and Child, Warsaw, Poland
| | - Iwona Terczyńska
- Department of Medical Genetics, Warsaw Medical University, Warsaw, Poland
| | - Julien Thevenon
- Department of Genetics, University of Bourgogne-Franche Comté, Dijon, France
| | - Andreas Tzschach
- Institute of Clinical Genetics, Dresden University of Technology, Dresden, Germany
| | | | - Roberta Vittorini
- Department of Pediatrics, Regina Margherita Children's Hospital, Turin, Italy
| | - Sonja Walsh
- Institute of Clinical Genetics, Dresden University of Technology, Dresden, Germany
| | - Sarah Weckhuysen
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium.,Applied and Translational Genomics Group, Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Barbara Weissman
- Center for Child and Adolescent Medicine, Pediatric Neurology, Heidelberg University Hospital, Heidelberg, Germany
| | - Lynne Wolfe
- National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | | | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Heather Olson
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Gaetan Lesca
- Department of Medical Genetics, University Hospital of Lyon, Lyon, France
| | - Ingrid E Scheffer
- Royal Children's Hospital, Florey institute and Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Departments of Medicine and Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Rikke S Møller
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.,Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
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Whyte MP, Zhang F, Wenkert D, Mack KE, Bijanki VN, Ericson KL, Coburn SP. Hypophosphatasia: Vitamin B 6 status of affected children and adults. Bone 2022; 154:116204. [PMID: 34547524 DOI: 10.1016/j.bone.2021.116204] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 12/20/2022]
Abstract
Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation(s) of the gene ALPL that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP is a cell-surface homodimeric phosphomonoester phosphohydrolase expressed in healthy people especially in the skeleton, liver, kidneys, and developing teeth. In HPP, diminished TNSALP activity leads to extracellular accumulation of its natural substrates including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving >450 usually missense defects scattered throughout ALPL largely explains the remarkably broad-ranging severity of this inborn-error-of-metabolism. In 1985 when we identified elevated plasma PLP as a biochemical hallmark of HPP, all 14 investigated affected children and adults had markedly increased PLP levels. However, pyridoxal (PL), the dephosphorylated form of PLP that enters cells to cofactor many enzymatic reactions, was not low but often inexplicably elevated. Levels of pyridoxic acid (PA), the B6 degradation product quantified to assess B6 sufficiency, were unremarkable. Canonical signs or symptoms of B6 deficiency or toxicity were absent. B6-dependent seizures in infants with life-threatening HPP were later explained by their profound deficiency of TNSALP activity blocking PLP dephosphorylation to PL and diminishing gamma-aminobutyric acid synthesis in the brain. Now, there is speculation that altered B6 metabolism causes further clinical complications in HPP. Herein, we assessed the plasma PL and PA levels accompanying previously reported elevated plasma PLP concentrations in 150 children and adolescents with HPP. Their mean (SD) plasma PL level was nearly double the mean for our healthy pediatric controls: 66.7 (59.0) nM versus 37.1 (22.2) nM (P < 0.0001), respectively. Their PA levels were broader than our pediatric control range, but their mean value was normal; 40.2 (25.1) nM versus 39.3 (9.9) nM (P = 0.7793), respectively. In contrast, adults with HPP often had plasma PL and PA levels suggestive of dietary B6 insufficiency. We discuss why the B6 levels of our pediatric patients with HPP would not cause B6 toxicity or deficiency, whereas in affected adults dietary B6 insufficiency can develop.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Fan Zhang
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Deborah Wenkert
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Karen E Mack
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Vinieth N Bijanki
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Karen L Ericson
- Department of Chemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
| | - Stephen P Coburn
- Department of Chemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
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Tanigawa J, Nabatame S, Tominaga K, Nishimura Y, Maegaki Y, Kinosita T, Murakami Y, Ozono K. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021; 43:680-687. [PMID: 33824024 DOI: 10.1016/j.braindev.2021.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/21/2021] [Accepted: 02/28/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We aimed to assess the efficacy and safety of high-dose pyridoxine treatment for seizures and its effects on development in patients with inherited glycosylphosphatidylinositol deficiencies (IGDs). METHODS In this prospective open-label multicenter pilot study, we enrolled patients diagnosed with IGDs using flow cytometry and/or genetic tests. The patients received oral pyridoxine (20-30 mg/kg/day) for 1 year, in addition to previous treatment. RESULTS All nine enrolled patients (mean age: 66.3 ± 44.3 months) exhibited marked decreases in levels of CD16, a glycosylphosphatidylinositol-anchored protein, on blood granulocytes. The underlying genetic causes of IGDs were PIGO, PIGL, and unknown gene mutations in two, two, and five patients, respectively. Six patients experienced seizures, while all patients presented with developmental delay (mean developmental age: 11.1 ± 8.1 months). Seizure frequencies were markedly (>50%) and drastically (>90%) reduced in three and one patients who experienced seizures, respectively. None of the patients presented with seizure exacerbation. Eight of nine patients exhibited modest improvements in development (P = 0.14). No adverse events were observed except for mild transient diarrhea in one patient. CONCLUSION One year of daily high-dose pyridoxine treatment was effective in the treatment of seizures in more than half of our patients with IGDs and modestly improved development in the majority of them. Moreover, such treatment was reasonably safe. These findings indicate that high-dose pyridoxine treatment may be effective against seizures in patients with IGDs, although further studies are required to confirm our findings. (University Hospital Medical Information Network Clinical Trials Registry [UMIN-CTR] number: UMIN000024185.).
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Affiliation(s)
- Junpei Tanigawa
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shin Nabatame
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Koji Tominaga
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Division of Developmental Neuroscience, United Graduate School of Child Development, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoko Nishimura
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Yoshihiro Maegaki
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Taroh Kinosita
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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Moretti R, Peinkhofer C. B Vitamins and Fatty Acids: What Do They Share with Small Vessel Disease-Related Dementia? Int J Mol Sci 2019; 20:E5797. [PMID: 31752183 PMCID: PMC6888477 DOI: 10.3390/ijms20225797] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 10/21/2019] [Accepted: 11/12/2019] [Indexed: 12/12/2022] Open
Abstract
Many studies have been written on vitamin supplementation, fatty acid, and dementia, but results are still under debate, and no definite conclusion has yet been drawn. Nevertheless, a significant amount of lab evidence confirms that vitamins of the B group are tightly related to gene control for endothelium protection, act as antioxidants, play a co-enzymatic role in the most critical biochemical reactions inside the brain, and cooperate with many other elements, such as choline, for the synthesis of polyunsaturated phosphatidylcholine, through S-adenosyl-methionine (SAM) methyl donation. B-vitamins have anti-inflammatory properties and act in protective roles against neurodegenerative mechanisms, for example, through modulation of the glutamate currents and a reduction of the calcium currents. In addition, they also have extraordinary antioxidant properties. However, laboratory data are far from clinical practice. Many studies have tried to apply these results in everyday clinical activity, but results have been discouraging and far from a possible resolution of the associated mysteries, like those represented by Alzheimer's disease (AD) or small vessel disease dementia. Above all, two significant problems emerge from the research: No consensus exists on general diagnostic criteria-MCI or AD? Which diagnostic criteria should be applied for small vessel disease-related dementia? In addition, no general schema exists for determining a possible correct time of implementation to have effective results. Here we present an up-to-date review of the literature on such topics, shedding some light on the possible interaction of vitamins and phosphatidylcholine, and their role in brain metabolism and catabolism. Further studies should take into account all of these questions, with well-designed and world-homogeneous trials.
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Affiliation(s)
- Rita Moretti
- Neurology Clinic, Department of Medical, Surgical and Health Sciences, University of Trieste, 34149 Trieste, Italy;
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