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Marten LM, Krätzner R, Salomons GS, Fernandez Ojeda M, Dechent P, Gärtner J, Huppke P, Dreha-Kulaczewski S. Long term follow-up in GAMT deficiency - Correlation of therapy regimen, biochemical and in vivo brain proton MR spectroscopy data. Mol Genet Metab Rep 2024; 38:101053. [PMID: 38469086 PMCID: PMC10926185 DOI: 10.1016/j.ymgmr.2024.101053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 03/13/2024] Open
Abstract
GAMT deficiency is a rare autosomal recessive disease within the group of cerebral creatine deficiency syndromes. Cerebral creatine depletion and accumulation of guanidinoacetate (GAA) lead to clinical presentation with intellectual disability, seizures, speech disturbances and movement disorders. Treatment consists of daily creatine supplementation to increase cerebral creatine, reduction of arginine intake and supplementation of ornithine for reduction of toxic GAA levels. This study represents the first long-term follow-up over a period of 14 years, with detailed clinical data, biochemical and multimodal neuroimaging findings. Developmental milestones, brain MRI, quantitative single voxel 1H magnetic resonance spectroscopy (MRS) and biochemical analyses were assessed. The results reveal insights into the dose dependent effects of creatine/ornithine supplementation and expand the phenotypic spectrum of GAMT deficiency. Of note, the creatine concentrations, which were regularly monitored over a long follow-up period, increased significantly over time, but did not reach age matched control ranges. Our patient is the second reported to show normal neurocognitive outcome after an initial delay, stressing the importance of early diagnosis and treatment initiation.
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Affiliation(s)
- Lara M. Marten
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Germany
| | - Ralph Krätzner
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Germany
| | - Gajja S. Salomons
- Amsterdam UMC location University of Amsterdam, Dept of Laboratory Medicine, Laboratory Genetic Metabolic Diseases and Dept of Pediatrics Emma Children's Hospital, Meibergdreef 9, Amsterdam, the Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands
| | - Matilde Fernandez Ojeda
- Amsterdam UMC location University of Amsterdam, Dept of Laboratory Medicine, Laboratory Genetic Metabolic Diseases and Dept of Pediatrics Emma Children's Hospital, Meibergdreef 9, Amsterdam, the Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands
| | - Peter Dechent
- MR-Research in Neurosciences, Department of Cognitive Neurology, University Medical Center Goettingen, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Germany
| | - Peter Huppke
- Department of Neuropediatrics, Jena University Hospital, Germany
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2
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Sugimoto C, Perna MK, Regan SL, Tepe EA, Liou R, Fritz AL, Williams MT, Vorhees CV, Skelton MR. A Gad2 specific Slc6a8 deletion recapitulates the contextual and cued freezing deficits seen in Slc6a8 -/y mice. Brain Res 2024; 1825:148690. [PMID: 38030104 PMCID: PMC10875619 DOI: 10.1016/j.brainres.2023.148690] [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: 08/21/2023] [Revised: 11/14/2023] [Accepted: 11/25/2023] [Indexed: 12/01/2023]
Abstract
The creatine (Cr)-phosphocreatine shuttle is essential for ATP homeostasis. In humans, the absence of brain Cr causes significant intellectual disability, epilepsy, and language delay. Mutations of the creatine transporter (SLC6A8) are the most common cause of Cr deficiency. In rodents, Slc6a8 deletion causes deficits in spatial learning, novel object recognition (NOR), as well as in contextual and cued freezing. The mechanisms that underlie these cognitive deficits are not known. Due to the heterogeneous nature of the brain, it is important to determine which systems are affected by a loss of Cr. In this study, we generated mice lacking Slc6a8 in GABAergic neurons by crossing Slc6a8FL mice with Gad2-Cre mice. These Gad2-specific Slc6a8 knockout (cKO) mice, along with the ubiquitous Slc6a8 KO (Slc6a8-/y), Gad2-Cre+, and wild-type (WT) mice were tested in the Morris water maze, NOR, conditioned freezing, and the radial water maze. Similar to the Slc6a8-/y mice, cKO mice had reduced contextual and cued freezing compared with WT mice. The cKO mice had a mild spatial learning deficit during the reversal phase of the MWM, however they were not as pronounced as in Slc6a8-/y mice. In NOR, the Gad2-Cre mice spent less time with the novel object, similar to the reduced novel time in the cKO mice. There were no changes in radial water maze performance. Slc6a8 deletion in GABAergic neurons is sufficient to recapitulate the conditioned freezing deficits seen in Slc6a8-/y mice.
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Affiliation(s)
- Chiho Sugimoto
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States
| | - Marla K Perna
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
| | - Samantha L Regan
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
| | - Erin A Tepe
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States
| | - Rosalyn Liou
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
| | - Adam L Fritz
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States
| | - Michael T Williams
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
| | - Charles V Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
| | - Matthew R Skelton
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229, United States.
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3
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Broca-Brisson L, Harati R, Disdier C, Mozner O, Gaston-Breton R, Maïza A, Costa N, Guyot AC, Sarkadi B, Apati A, Skelton MR, Madrange L, Yates F, Armengaud J, Hamoudi R, Mabondzo A. Deciphering neuronal deficit and protein profile changes in human brain organoids from patients with creatine transporter deficiency. eLife 2023; 12:RP88459. [PMID: 37830910 PMCID: PMC10575631 DOI: 10.7554/elife.88459] [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: 10/14/2023] Open
Abstract
Creatine transporter deficiency (CTD) is an X-linked disease caused by mutations in the SLC6A8 gene. The impaired creatine uptake in the brain results in intellectual disability, behavioral disorders, language delay, and seizures. In this work, we generated human brain organoids from induced pluripotent stem cells of healthy subjects and CTD patients. Brain organoids from CTD donors had reduced creatine uptake compared with those from healthy donors. The expression of neural progenitor cell markers SOX2 and PAX6 was reduced in CTD-derived organoids, while GSK3β, a key regulator of neurogenesis, was up-regulated. Shotgun proteomics combined with integrative bioinformatic and statistical analysis identified changes in the abundance of proteins associated with intellectual disability, epilepsy, and autism. Re-establishment of the expression of a functional SLC6A8 in CTD-derived organoids restored creatine uptake and normalized the expression of SOX2, GSK3β, and other key proteins associated with clinical features of CTD patients. Our brain organoid model opens new avenues for further characterizing the CTD pathophysiology and supports the concept that reinstating creatine levels in patients with CTD could result in therapeutic efficacy.
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Affiliation(s)
- Léa Broca-Brisson
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Rania Harati
- Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University of SharjahSharjahUnited Arab Emirates
- Sharjah Institute for Medical Research, University of SharjahSharjahUnited Arab Emirates
| | | | - Orsolya Mozner
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Romane Gaston-Breton
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Auriane Maïza
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Narciso Costa
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Anne-Cécile Guyot
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
| | - Balazs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Agota Apati
- Institute of Enzymology, Research Centre for Natural Sciences, ELKH, and Doctoral School of Molecular Medicine, Semmelweis UniversityBudapestHungary
| | - Matthew R Skelton
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children’s Research FoundationCincinnatiUnited States
| | - Lucie Madrange
- SupBiotech/Service d'Etude des Prions et des Infections Atypiques (SEPIA), Institut François Jacob, CEA, Université Paris SaclayParisFrance
| | - Frank Yates
- SupBiotech/Service d'Etude des Prions et des Infections Atypiques (SEPIA), Institut François Jacob, CEA, Université Paris SaclayParisFrance
| | - Jean Armengaud
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPIBagnols-sur-CèzeFrance
| | - Rifat Hamoudi
- Clinical Sciences Department, College of Medicine, University of SharjahSharjahUnited Arab Emirates
- Division of Surgery and Interventional Science, University College LondonLondonUnited Kingdom
- ASPIRE Precision Medicine Research Institute Abu Dhabi, University of SharjahSharjahUnited Arab Emirates
| | - Aloïse Mabondzo
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la SantéGif sur YvetteFrance
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4
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Lyons EL, Watson D, Alodadi MS, Haugabook SJ, Tawa GJ, Hannah-Shmouni F, Porter FD, Collins JR, Ottinger EA, Mudunuri US. Rare disease variant curation from literature: assessing gaps with creatine transport deficiency in focus. BMC Genomics 2023; 24:460. [PMID: 37587458 PMCID: PMC10433598 DOI: 10.1186/s12864-023-09561-5] [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: 04/04/2023] [Accepted: 08/08/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND Approximately 4-8% of the world suffers from a rare disease. Rare diseases are often difficult to diagnose, and many do not have approved therapies. Genetic sequencing has the potential to shorten the current diagnostic process, increase mechanistic understanding, and facilitate research on therapeutic approaches but is limited by the difficulty of novel variant pathogenicity interpretation and the communication of known causative variants. It is unknown how many published rare disease variants are currently accessible in the public domain. RESULTS This study investigated the translation of knowledge of variants reported in published manuscripts to publicly accessible variant databases. Variants, symptoms, biochemical assay results, and protein function from literature on the SLC6A8 gene associated with X-linked Creatine Transporter Deficiency (CTD) were curated and reported as a highly annotated dataset of variants with clinical context and functional details. Variants were harmonized, their availability in existing variant databases was analyzed and pathogenicity assignments were compared with impact algorithm predictions. 24% of the pathogenic variants found in PubMed articles were not captured in any database used in this analysis while only 65% of the published variants received an accurate pathogenicity prediction from at least one impact prediction algorithm. CONCLUSIONS Despite being published in the literature, pathogenicity data on patient variants may remain inaccessible for genetic diagnosis, therapeutic target identification, mechanistic understanding, or hypothesis generation. Clinical and functional details presented in the literature are important to make pathogenicity assessments. Impact predictions remain imperfect but are improving, especially for single nucleotide exonic variants, however such predictions are less accurate or unavailable for intronic and multi-nucleotide variants. Developing text mining workflows that use natural language processing for identifying diseases, genes and variants, along with impact prediction algorithms and integrating with details on clinical phenotypes and functional assessments might be a promising approach to scale literature mining of variants and assigning correct pathogenicity. The curated variants list created by this effort includes context details to improve any such efforts on variant curation for rare diseases.
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Affiliation(s)
- Erica L Lyons
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Daniel Watson
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Mohammad S Alodadi
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Sharie J Haugabook
- Division of Preclinical Innovation, Therapeutic Development Branch, Therapeutics for Rare and Neglected Diseases (TRND) Program, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Gregory J Tawa
- Division of Preclinical Innovation, Therapeutic Development Branch, Therapeutics for Rare and Neglected Diseases (TRND) Program, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Fady Hannah-Shmouni
- Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Forbes D Porter
- Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jack R Collins
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Elizabeth A Ottinger
- Division of Preclinical Innovation, Therapeutic Development Branch, Therapeutics for Rare and Neglected Diseases (TRND) Program, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Uma S Mudunuri
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA.
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5
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Almatrafi M, Al-Sabban Z, Balkhy S, Abumansour IS. Case Report: X-Linked Creatine Transporter Deficiency in Two Saudi Brothers with Autism. J Autism Dev Disord 2023; 53:1273-1278. [PMID: 36520361 DOI: 10.1007/s10803-022-05860-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Mohammed Almatrafi
- Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 127, Makkah, 21961, Saudi Arabia
| | - Zehour Al-Sabban
- Department of Radiology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Soher Balkhy
- General Pediatric Section, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Iman Sabri Abumansour
- Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 127, Makkah, 21961, Saudi Arabia.
- Pediatric Neurology Section, Department of Pediatrics, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah, 21499, Saudi Arabia.
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6
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Chen HR, DeGrauw T, Kuan CY. (Phospho)creatine: the reserve and merry-go-round of brain energetics. Neural Regen Res 2023; 18:327-328. [PMID: 35900419 PMCID: PMC9396488 DOI: 10.4103/1673-5374.346470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/21/2022] [Accepted: 03/21/2022] [Indexed: 11/12/2022] Open
Affiliation(s)
- Hong-Ru Chen
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Ton DeGrauw
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, GA, USA
| | - Chia-Yi Kuan
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, VA, USA
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7
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Farr CV, El-Kasaby A, Erdem FA, Sucic S, Freissmuth M, Sandtner W. Cooperative Binding of Substrate and Ions Drives Forward Cycling of the Human Creatine Transporter-1. Front Physiol 2022; 13:919439. [PMID: 35837012 PMCID: PMC9273935 DOI: 10.3389/fphys.2022.919439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022] Open
Abstract
Creatine serves as an ATP buffer and is thus an integral component of cellular energy metabolism. Most cells maintain their creatine levels via uptake by the creatine transporter (CRT-1, SLC6A8). The activity of CRT-1, therefore, is a major determinant of cytosolic creatine concentrations. We determined the kinetics of CRT-1 in real time by relying on electrophysiological recordings of transport-associated currents. Our analysis revealed that CRT-1 harvested the concentration gradient of NaCl and the membrane potential but not the potassium gradient to achieve a very high concentrative power. We investigated the mechanistic basis for the ability of CRT-1 to maintain the forward cycling mode in spite of high intracellular concentrations of creatine: this is achieved by cooperative binding of substrate and co-substrate ions, which, under physiological ion conditions, results in a very pronounced (i.e. about 500-fold) drop in the affinity of creatine to the inward-facing state of CRT-1. Kinetic estimates were integrated into a mathematical model of the transport cycle of CRT-1, which faithfully reproduced all experimental data. We interrogated the kinetic model to examine the most plausible mechanistic basis of cooperativity: based on this systematic exploration, we conclude that destabilization of binary rather than ternary complexes is necessary for CRT-1 to maintain the observed cytosolic creatine concentrations. Our model also provides a plausible explanation why neurons, heart and skeletal muscle cells must express a creatine releasing transporter to achieve rapid equilibration of the intracellular creatine pool.
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Affiliation(s)
| | | | | | | | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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8
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Morey K, Hallinan B, Cecil KM. Case report: Clinical and magnetic resonance spectroscopy presentation of a female severely affected with X-linked creatine transporter deficiency. Radiol Case Rep 2022; 17:1115-1119. [PMID: 35169411 PMCID: PMC8829519 DOI: 10.1016/j.radcr.2022.01.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/30/2022] Open
Abstract
Creatine transporter deficiency is an X-linked genetic disorder caused by a variant in the SLC6A8 gene located on the X chromosome (Xq28). This condition varies in severity with features often including intellectual disabilities, speech delay, autistic features, attention deficit hyperactivity and gastrointestinal issues. While creatine transporter deficiency primarily affects males, females may also demonstrate severe phenotypes. However, screening of creatine transporter deficiency in females can be especially difficult as urine creatine/creatinine screenings often have values falling within normative ranges. Also, females may not demonstrate the characteristic reduction of creatine concentrations in the brain visualized with in vivo proton magnetic resonance spectroscopy. Identification typically results from exome sequencing. In this report, we present the clinical, imaging, and spectroscopy features of a heterozygous female with a severe presentation of creatine transporter deficiency.
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Affiliation(s)
- Katherine Morey
- Summer Undergraduate Research Fellowship Program, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, MLC 5033, Cincinnati, OH 45229, USA
| | - Barbara Hallinan
- Department of Pediatrics, Division of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Kim M. Cecil
- Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, MLC 5033, Cincinnati, OH 45229, USA
- Corresponding author.
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9
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Lai LM, Gropman AL, Whitehead MT. MR Neuroimaging in Pediatric Inborn Errors of Metabolism. Diagnostics (Basel) 2022; 12:diagnostics12040861. [PMID: 35453911 PMCID: PMC9027484 DOI: 10.3390/diagnostics12040861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 02/04/2023] Open
Abstract
Inborn errors of metabolism (IEM) are a group of disorders due to functional defects in one or more metabolic pathways that can cause considerable morbidity and death if not diagnosed early. While individually rare, the estimated global prevalence of IEMs comprises a substantial number of neonatal and infantile disorders affecting the central nervous system. Clinical manifestations of IEMs may be nonspecific. Newborn metabolic screens do not capture all IEMs, and likewise, genetic testing may not always detect pathogenic variants. Neuroimaging is a critical component of the work-up, given that imaging sometimes occurs before prenatal screen results are available, which may allow for recognition of imaging patterns that lead to early diagnosis and treatment of IEMs. This review will demonstrate the role of magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS) in the evaluation of IEMs. The focus will be on scenarios where MRI and 1H MRS are suggestive of or diagnostic for IEMs, or alternatively, refute the diagnosis.
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Affiliation(s)
- Lillian M. Lai
- Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA;
- Department of Radiology, Children’s Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Andrea L. Gropman
- Department of Neurology, Children’s National, Washington, DC 20010, USA;
| | - Matthew T. Whitehead
- Department of Radiology, Children’s National, Washington, DC 20010, USA
- Correspondence: ; Tel.: +1-202-476-5000
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10
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Fernandes-Pires G, Braissant O. Current and potential new treatment strategies for creatine deficiency syndromes. Mol Genet Metab 2022; 135:15-26. [PMID: 34972654 DOI: 10.1016/j.ymgme.2021.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 12/16/2022]
Abstract
Creatine deficiency syndromes (CDS) are inherited metabolic disorders caused by mutations in GATM, GAMT and SLC6A8 and mainly affect central nervous system (CNS). AGAT- and GAMT-deficient patients lack the functional brain endogenous creatine (Cr) synthesis pathway but express the Cr transporter SLC6A8 at blood-brain barrier (BBB), and can thus be treated by oral supplementation of high doses of Cr. For Cr transporter deficiency (SLC6A8 deficiency or CTD), current treatment strategies benefit one-third of patients. However, as their phenotype is not completely reversed, and for the other two-thirds of CTD patients, the development of novel more effective therapies is needed. This article aims to review the current knowledge on Cr metabolism and CDS clinical aspects, highlighting their current treatment possibilities and the most recent research perspectives on CDS potential therapeutics designed, in particular, to bring new options for the treatment of CTD.
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Affiliation(s)
- Gabriella Fernandes-Pires
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland.
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11
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Baker SA, Gajera CR, Wawro AM, Corces MR, Montine TJ. GATM and GAMT synthesize creatine locally throughout the mammalian body and within oligodendrocytes of the brain. Brain Res 2021; 1770:147627. [PMID: 34418357 DOI: 10.1016/j.brainres.2021.147627] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 08/08/2021] [Accepted: 08/14/2021] [Indexed: 11/17/2022]
Abstract
The enzymes glycine amidinotransferase, mitochondrial (GATM also known as AGAT) and guanidinoacetate N-methyltransferase (GAMT) function together to synthesize creatine from arginine, glycine, and S-Adenosyl methionine. Deficiency in either enzyme or the creatine transporter, CT1, results in a devastating neurological disorder, Cerebral Creatine Deficiency Syndrome (CCDS). To better understand the pathophysiology of CCDS, we mapped the distribution of GATM and GAMT at single cell resolution, leveraging RNA sequencing analysis combined with in vivo immunofluorescence (IF). Using the mouse as a model system, we find that GATM and GAMT are coexpressed in several tissues with distinct and overlapping cellular sources, implicating local synthesis as an important mechanism of creatine metabolism in numerous organs. Extending previous findings at the RNA level, our analysis demonstrates that oligodendrocytes express the highest level of Gatm and Gamt of any cell type in the body. We confirm this finding in the mouse brain by IF, where GATM localizes to the mitochondria of oligodendrocytes, whereas both oligodendrocytes and cerebral cortical neurons express GAMT. Interestingly, the latter is devoid of GATM. Single nucleus assay for transposase-accessible chromatin sequencing (snATAC-seq) analysis of 4 brain regions highlights a similar primacy of oligodendrocytes in the expression of GATM and GAMT in the human central nervous system. Importantly, an active putative regulatory element within intron 2 of human GATM is detected in oligodendrocytes but not neurons.
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Affiliation(s)
- Steven Andrew Baker
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Chandresh R Gajera
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Adam M Wawro
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - M Ryan Corces
- Gladstone Institute of Neurological Disease, Gladstone Institute of Data Science and Biotechnology, San Francisco, CA 94158, USA; Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Thomas J Montine
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94035, USA; Lead Contact.
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12
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Chen HR, Zhang-Brotzge X, Morozov YM, Li Y, Wang S, Zhang HH, Kuan IS, Fugate EM, Mao H, Sun YY, Rakic P, Lindquist DM, DeGrauw T, Kuan CY. Creatine transporter deficiency impairs stress adaptation and brain energetics homeostasis. JCI Insight 2021; 6:e140173. [PMID: 34324436 PMCID: PMC8492331 DOI: 10.1172/jci.insight.140173] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/28/2021] [Indexed: 11/22/2022] Open
Abstract
The creatine transporter (CrT) maintains brain creatine (Cr) levels, but the effects of its deficiency on energetics adaptation under stress remain unclear. There are also no effective treatments for CrT deficiency, the second most common cause of X-linked intellectual disabilities. Herein, we examined the consequences of CrT deficiency in brain energetics and stress-adaptation responses plus the effects of intranasal Cr supplementation. We found that CrT-deficient (CrT–/y) mice harbored dendritic spine and synaptic dysgenesis. Nurtured newborn CrT–/y mice maintained baseline brain ATP levels, with a trend toward signaling imbalance between the p-AMPK/autophagy and mTOR pathways. Starvation elevated the signaling imbalance and reduced brain ATP levels in P3 CrT–/y mice. Similarly, CrT–/y neurons and P10 CrT–/y mice showed an imbalance between autophagy and mTOR signaling pathways and greater susceptibility to cerebral hypoxia-ischemia and ischemic insults. Notably, intranasal administration of Cr after cerebral ischemia increased the brain Cr/N-acetylaspartate ratio, partially averted the signaling imbalance, and reduced infarct size more potently than intraperitoneal Cr injection. These findings suggest important functions for CrT and Cr in preserving the homeostasis of brain energetics in stress conditions. Moreover, intranasal Cr supplementation may be an effective treatment for congenital CrT deficiency and acute brain injury.
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Affiliation(s)
- Hong-Ru Chen
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Xiaohui Zhang-Brotzge
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Yury M Morozov
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yuancheng Li
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Siming Wang
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | | | - Irena S Kuan
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Elizabeth M Fugate
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Hui Mao
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Yu-Yo Sun
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Pasko Rakic
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Diana M Lindquist
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Ton DeGrauw
- Department of Pediatrics, Division of Neurology, Emory University, Atlanta, Georgia, USA
| | - Chia-Yi Kuan
- Department of Neurosciences, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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13
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Ghirardini E, Calugi F, Sagona G, Di Vetta F, Palma M, Battini R, Cioni G, Pizzorusso T, Baroncelli L. The Role of Preclinical Models in Creatine Transporter Deficiency: Neurobiological Mechanisms, Biomarkers and Therapeutic Development. Genes (Basel) 2021; 12:genes12081123. [PMID: 34440297 PMCID: PMC8392480 DOI: 10.3390/genes12081123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Creatine (Cr) Transporter Deficiency (CTD) is an X-linked metabolic disorder, mostly caused by missense mutations in the SLC6A8 gene and presenting with intellectual disability, autistic behavior, and epilepsy. There is no effective treatment for CTD and patients need lifelong assistance. Thus, the research of novel intervention strategies is a major scientific challenge. Animal models are an excellent tool to dissect the disease pathogenetic mechanisms and drive the preclinical development of therapeutics. This review illustrates the current knowledge about Cr metabolism and CTD clinical aspects, with a focus on mainstay diagnostic and therapeutic options. Then, we discuss the rodent models of CTD characterized in the last decade, comparing the phenotypes expressed within clinically relevant domains and the timeline of symptom development. This analysis highlights that animals with the ubiquitous deletion/mutation of SLC6A8 genes well recapitulate the early onset and the complex pathological phenotype of the human condition. Thus, they should represent the preferred model for preclinical efficacy studies. On the other hand, brain- and cell-specific conditional mutants are ideal for understanding the basis of CTD at a cellular and molecular level. Finally, we explain how CTD models might provide novel insight about the pathogenesis of other disorders, including cancer.
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MESH Headings
- Animals
- Biomarkers/metabolism
- Brain Diseases, Metabolic, Inborn/metabolism
- Brain Diseases, Metabolic, Inborn/pathology
- Brain Diseases, Metabolic, Inborn/therapy
- Central Nervous System/pathology
- Creatine/deficiency
- Creatine/metabolism
- Disease Models, Animal
- Humans
- Mental Retardation, X-Linked/metabolism
- Mental Retardation, X-Linked/pathology
- Mental Retardation, X-Linked/therapy
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/metabolism
- Rats
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Affiliation(s)
- Elsa Ghirardini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
| | - Francesco Calugi
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Giulia Sagona
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Federica Di Vetta
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Biology, University of Pisa, I-56126 Pisa, Italy
| | - Martina Palma
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126 Pisa, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135 Florence, Italy
| | - Laura Baroncelli
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy; (E.G.); (G.S.); (R.B.); (G.C.)
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; (F.C.); (F.D.V.); (M.P.); (T.P.)
- Correspondence:
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14
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Wawro AM, Gajera CR, Baker SA, Nirschl JJ, Vogel H, Montine TJ. Creatine transport and pathological changes in creatine transporter deficient mice. J Inherit Metab Dis 2021; 44:939-948. [PMID: 33389772 DOI: 10.1002/jimd.12358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 01/26/2023]
Abstract
The severe impact on brain function and lack of effective therapy for patients with creatine (Cr) transporter deficiency motivated the generation of three ubiquitous Slc6a8 deficient mice (-/y). While each mouse knock-out line has similar behavioral effects at 2 to 3 months of age, other features critical to the efficient use of these mice in drug discovery are unclear or lacking: the concentration of Cr in brain and heart differ widely between mouse lines, there are limited data on histopathologic changes, and no data on Cr uptake. Here, we determined survival, measured endogenous Cr and uptake of its deuterium-labeled analogue Cr-d3 using a liquid chromatography coupled with tandem mass spectrometry assay, and performed comprehensive histopathologic examination on the Slc6a8-/y mouse developed by Skelton et al. Our results show that Slc6a8-/y mice have widely varying organ-specific uptake of Cr-d3, significantly diminished growth with the exception of brain, progressive vacuolar myopathy, and markedly shortened lifespan.
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Affiliation(s)
- Adam M Wawro
- Department of Pathology, Stanford University, Stanford, California, USA
| | | | - Steven A Baker
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Jeffrey J Nirschl
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Thomas J Montine
- Department of Pathology, Stanford University, Stanford, California, USA
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15
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Şimşek S, Hattapoğlu S, Ekici F. Value of Magnetic Resonance Spectroscopy for Diagnosis of Creatine Deficiency Syndrome. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1726311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractCreatine deficiency syndromes are congenital metabolic diseases characterized by decreased cerebral creatine levels as a result of disorders in creatine synthesis and transport. Therefore, magnetic resonance spectroscopy is a valuable tool for diagnosis. This disease can be explained by congenital disorders occurring in three forms at different stages of the creatine metabolic pathway. Two of disorders arise autosomal recessively in creatine biosynthesis, arginine-glycine amidinotransferase, and guanidinoacetate methyltransferase enzyme deficiency. The third disorder occurs as a result of an SLC6A8 variant in the form of creatine carrier protein deficiency. In this article, a patient with SLC6A8 carrier deficiency is presented.
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Affiliation(s)
- Sadullah Şimşek
- Department of Radiology, Medical School, Dicle University, Diyarbakir, Turkey
| | - Salih Hattapoğlu
- Department of Radiology, Medical School, Dicle University, Diyarbakir, Turkey
| | - Faysal Ekici
- Department of Radiology, Medical School, Dicle University, Diyarbakir, Turkey
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16
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Li S, Bianconi S, van der Veen JW, Do AD, Stolinski J, Cecil KM, Hannah-Shmouni F, Porter FD, Shen J. Oxidative phosphorylation in creatine transporter deficiency. NMR IN BIOMEDICINE 2021; 34:e4419. [PMID: 32990357 PMCID: PMC7722185 DOI: 10.1002/nbm.4419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/03/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
X-linked creatine transporter deficiency (CTD) is one of the three types of cerebral creatine deficiency disorders. CTD arises from pathogenic variants in the X-linked gene SLC6A8. We report the first phosphorus (31 P) MRS study of patients with CTD, where both phosphocreatine and total creatine concentrations were found to be markedly reduced. Despite the diminished role of creatine and phosphocreatine in oxidative phosphorylation in CTD, we found no elevation of lactate or lowered pH, indicating that the brain energy supply still largely relied on oxidative metabolism. Our results suggest that mitochondrial function is a potential therapeutic target for CTD.
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Affiliation(s)
- Shizhe Li
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Simona Bianconi
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | | | - An Dang Do
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - JoEllyn Stolinski
- NMR Facility, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Kim M. Cecil
- Department of Radiology, Cincinnati Children’s Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Fady Hannah-Shmouni
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Forbes D. Porter
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Jun Shen
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
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17
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Fei Y, Shi R, Song Z, Wu J. Metabolic Control of Epilepsy: A Promising Therapeutic Target for Epilepsy. Front Neurol 2020; 11:592514. [PMID: 33363507 PMCID: PMC7753014 DOI: 10.3389/fneur.2020.592514] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/20/2020] [Indexed: 12/16/2022] Open
Abstract
Epilepsy is a common neurological disease that is not always controlled, and the ketogenic diet shows good antiepileptic effects drug-resistant epilepsy or seizures caused by specific metabolic defects via regulating the metabolism. The brain is a vital organ with high metabolic demands, and epileptic foci tend to exhibit high metabolic characteristics. Accordingly, there has been growing interest in the relationship between brain metabolism and epilepsy in recent years. To date, several new antiepileptic therapies targeting metabolic pathways have been proposed (i.e., inhibiting glycolysis, targeting lactate dehydrogenase, and dietary therapy). Promising strategies to treat epilepsy via modulating the brain's metabolism could be expected, while a lack of thorough understanding of the role of brain metabolism in the control of epilepsy remains. Herein, this review aims to provide insight into the state of the art concerning the brain's metabolic patterns and their association with epilepsy. Regulation of neuronal excitation via metabolic pathways and antiepileptic therapies targeting metabolic pathways are emphasized, which could provide a better understanding of the role of metabolism in epilepsy and could reveal potential therapeutic targets.
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Affiliation(s)
- Yanqing Fei
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ruting Shi
- Department of Rehabilitation, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jinze Wu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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18
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Mazziotti R, Cacciante F, Sagona G, Lupori L, Gennaro M, Putignano E, Alessandrì MG, Ferrari A, Battini R, Cioni G, Pizzorusso T, Baroncelli L. Novel translational phenotypes and biomarkers for creatine transporter deficiency. Brain Commun 2020; 2:fcaa089. [PMID: 32954336 PMCID: PMC7472907 DOI: 10.1093/braincomms/fcaa089] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/20/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Creatine transporter deficiency is a metabolic disorder characterized by intellectual disability, autistic-like behaviour and epilepsy. There is currently no cure for creatine transporter deficiency, and reliable biomarkers of translational value for monitoring disease progression and response to therapeutics are sorely lacking. Here, we found that mice lacking functional creatine transporter display a significant alteration of neural oscillations in the EEG and a severe epileptic phenotype that are recapitulated in patients with creatine transporter deficiency. In-depth examination of knockout mice for creatine transporter also revealed that a decrease in EEG theta power is predictive of the manifestation of spontaneous seizures, a frequency that is similarly affected in patients compared to healthy controls. In addition, knockout mice have a highly specific increase in haemodynamic responses in the cerebral cortex following sensory stimuli. Principal component and Random Forest analyses highlighted that these functional variables exhibit a high performance in discriminating between pathological and healthy phenotype. Overall, our findings identify novel, translational and non-invasive biomarkers for the analysis of brain function in creatine transporter deficiency, providing a very reliable protocol to longitudinally monitor the efficacy of potential therapeutic strategies in preclinical, and possibly clinical, studies.
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Affiliation(s)
- Raffaele Mazziotti
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | | | - Giulia Sagona
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Leonardo Lupori
- BIO@SNS Lab, Scuola Normale Superiore di Pisa, Pisa I-56125, Italy
| | - Mariangela Gennaro
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Annarita Ferrari
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
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19
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Rostami P, Hosseinpour S, Ashrafi MR, Alizadeh H, Garshasbi M, Tavasoli AR. Primary creatine deficiency syndrome as a potential missed diagnosis in children with psychomotor delay and seizure: case presentation with two novel variants and literature review. Acta Neurol Belg 2020; 120:511-516. [PMID: 31222513 DOI: 10.1007/s13760-019-01168-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 06/06/2019] [Indexed: 11/24/2022]
Abstract
Creatine is the main source of energy for the brain. Primary creatine deficiency syndromes (PCDSs) are inborn error of metabolism of creatine synthesis. Symptoms of central nervous system involvement are the most common clinical manifestations in these disorders. We reviewed medical records of all genetically confirmed patients diagnosed by whole exome sequencing who were referred to Myelin and Neurodegenerative Disorders Clinic, Children's Medical Center, Tehran, Iran, from May 2016 to Dec 2018. A literature review was conducted on clinical and genomic variability of PCDS to compare our patients with previously reported cases. We report two patients with creatine deficiency among a cohort of 550 registered cases out of which 200 patients had a genetically confirmed neurodegenerative disorder diagnosis. The main complain in the first patient with creatine transporter (CRTR) deficiency was seizure and genetic study in this patient identified a novel hemizygote variant of "c.92 > T; p.Pro31Leu" in the first exon of SLC6A8 gene. The second patient with guanidinoacetate methyltransferase (GAMT) deficiency had an unknown motor and speech delay as the striking manifestation and molecular assay revealed a novel homozygote variant of "c.134G > A; p.Trp45*" in the first exon of GAMT gene. PCDSs usually are associated with nonspecific neurologic symptoms. The first presented case had a mean delayed diagnosis of 5 years. Therefore, in children with unexplained neurologic features including developmental delay and/or regression, mental disability and repeated seizures without any significant findings in metabolic studies, PCDSs can be considered as a differential diagnosis and molecular analysis can be helpful for the precise diagnosis and treatment.
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Affiliation(s)
- Parastoo Rostami
- Division of Pediatric Endocrinology and Metabolism, Growth and Development Research Center, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Sareh Hosseinpour
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Houman Alizadeh
- Division of Pediatric Radiology, Department of Pediatrics, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran.
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
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20
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Uemura T, Ito S, Masuda T, Shimbo H, Goto T, Osaka H, Wada T, Couraud PO, Ohtsuki S. Cyclocreatine Transport by SLC6A8, the Creatine Transporter, in HEK293 Cells, a Human Blood-Brain Barrier Model Cell, and CCDSs Patient-Derived Fibroblasts. Pharm Res 2020; 37:61. [PMID: 32124083 DOI: 10.1007/s11095-020-2779-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/04/2020] [Indexed: 01/04/2023]
Abstract
PURPOSE Cyclocreatine, a creatine analog, is a candidate drug for treating patients with cerebral creatine deficiency syndromes (CCDSs) caused by creatine transporter (CRT, SLC6A8) deficiency, which reduces brain creatine level. The purpose of this study was to clarify the characteristics of cyclocreatine transport in HEK293 cells, which highly express endogenous CRT, in hCMEC/D3 cells, a human blood-brain barrier (BBB) model, and in CCDSs patient-derived fibroblasts with CRT mutations. METHODS Cells were incubated at 37°C with [14C]cyclocreatine (9 μM) and [14C]creatine (9 μM) for specified periods of times in the presence or absence of inhibitors, while the siRNAs were transfected by lipofection. Protein expression and mRNA expression were quantified using targeted proteomics and quantitative PCR, respectively. RESULTS [14C]Cyclocreatine was taken up by HEK293 cells in a time-dependent manner, while exhibiting saturable kinetics. The inhibition and siRNA knockdown studies demonstrated that the uptake of [14C]cyclocreatine by both HEK293 and hCMEC/D3 cells was mediated predominantly by CRT as well as [14C]creatine. In addition, uptake of [14C]cyclocreatine and [14C]creatine by the CCDSs patient-derived fibroblasts was found to be largely reduced. CONCLUSION The present study suggests that cyclocreatine is a CRT substrate, where CRT is the predominant contributor to influx of cyclocreatine into the brain at the BBB. Our findings provide vital insights for the purposes of treating CCDSs patients using cyclocreatine.
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Affiliation(s)
- Tatsuki Uemura
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Shingo Ito
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Takeshi Masuda
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Hiroko Shimbo
- Division of Neurology, Kanagawa Children's Medical Center, Kanagawa, 232-8555, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children's Medical Center, Kanagawa, 232-8555, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical School, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Takahito Wada
- Department of Medical Ethics and Medical Genetics, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Pierre-Olivier Couraud
- Institut Cochin, Paris Descartes University, Inserm U1016, CNRS UMR8104, 75014, Paris, France
| | - Sumio Ohtsuki
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan. .,Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
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21
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Deletion of the Creatine Transporter (Slc6a8) in Dopaminergic Neurons Leads to Hyperactivity in Mice. J Mol Neurosci 2019; 70:102-111. [PMID: 31520365 DOI: 10.1007/s12031-019-01405-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/30/2019] [Indexed: 12/27/2022]
Abstract
The lack of cerebral creatine (Cr) causes intellectual disability and epilepsy. In addition, a significant portion of individuals with Cr transporter (Crt) deficiency (CTD), the leading cause of cerebral Cr deficiency syndromes (CCDS), are diagnosed with attention-deficit hyperactivity disorder. While the neurological effects of CTD are clear, the mechanisms that underlie these deficits are unknown. Part of this is due to the heterogenous nature of the brain and the unique metabolic demands of specific neuronal systems. Of particular interest related to Cr physiology are dopaminergic neurons, as many CCDS patients have ADHD and Cr has been implicated in dopamine-associated neurodegenerative disorders, such as Parkinson's and Huntington's diseases. The purpose of this study was to examine the effect of a loss of the Slc6a8 (Crt) gene in dopamine transporter (Slc6a3; DAT) expressing cells on locomotor activity and motor function as the mice age. Floxed Slc6a8 (Slc6a8flox) mice were mated to DATIREScre expressing mice to generate DAT-specific Slc6a8 knockouts (dCrt-/y). Locomotor activity, spontaneous activity, and performance in the challenging beam test were evaluated monthly in dCrt-/y and control (Slc6a8flox) mice from 3 to 12 months of age. dCrt-/y mice were hyperactive compared with controls throughout testing. In addition, dCrt-/y mice showed increased rearing and hindlimb steps in the spontaneous activity test. Latency to cross the narrow bridge was increased in dCrt-/y mice while foot slips were unchanged. Taken together, these data suggest that the lack of Cr in dopaminergic neurons causes hyperactivity while sparing motor function.
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Udobi KC, Delcimmuto N, Kokenge AN, Abdulla ZI, Perna MK, Skelton MR. Deletion of the creatine transporter gene in neonatal, but not adult, mice leads to cognitive deficits. J Inherit Metab Dis 2019; 42:966-974. [PMID: 31209903 PMCID: PMC6739135 DOI: 10.1002/jimd.12137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/15/2019] [Accepted: 06/13/2019] [Indexed: 12/20/2022]
Abstract
Creatine (Cr) is a guanidino compound that provides readily available phosphate pools for the regeneration of spent adenosine triphosphate (ATP). The lack of brain Cr causes moderate to severe intellectual disability, language impairment, and epilepsy. The most prevalent cause of Cr deficiency are mutations in the X-linked SLC6A8 (Creatine transporter; CrT) gene, known as CrT deficiency (CTD). One of the most critical areas that need to be addressed is whether Cr is necessary for brain development. To address this concern, the Slc6a8 gene was knocked out in either neonatal (postnatal day (P)5) or adult (P60) mice using a tamoxifen-inducible Cre recombinase driven by the human ubiquitin C (UBC) promoter. Mice were tested in the Morris water maze, novel, object recognition, and conditioned fear 60 days after Slc6a8 deletion. In addition, overnight locomotor activity was analyzed. Mice that had the gene deleted on P5 showed deficits in the Morris water maze and novel object recognition, while there were no deficits in P60 knockout mice. Interestingly, the P5 knockout mice showed hyperactivity during the dark phase; however, when examining control mice, the effect was due to the administration of tamoxifen from P5 to 10. Taken together, the results of this study show that Cr is necessary during periods of brain development involved in spatial and object learning. This study also highlights the continued importance of using proper control groups for behavioral testing.
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Abstract
With an ever aging population, identifying interventions that can alleviate age-related functional declines has become increasingly important. Dietary supplements have taken center stage based on various health claims and have become a multi-million dollar business. One such supplement is creatine, a major contributor to normal cellular physiology. Creatine, an energy source that can be endogenously synthesized or obtained through diet and supplement, is involved primarily in cellular metabolism via ATP replenishment. The goal of this chapter is to summarize how creatine and its associated enzyme, creatine kinase, act under normal physiological conditions, and how altered levels of either may lead to detrimental functional outcomes. Furthermore, we will focus on the effect of aging on the creatine system and how supplementation may affect the aging process and perhaps reverse it.
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Affiliation(s)
- Nathalie Sumien
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Ritu A Shetty
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Eric B Gonzales
- Department of Medical Education, TCU and UNTHSC School of Medicine, Fort Worth, TX, USA.
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24
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Giusti L, Molinaro A, Alessandrì MG, Boldrini C, Ciregia F, Lacerenza S, Ronci M, Urbani A, Cioni G, Mazzoni MR, Pizzorusso T, Lucacchini A, Baroncelli L. Brain mitochondrial proteome alteration driven by creatine deficiency suggests novel therapeutic venues for creatine deficiency syndromes. Neuroscience 2019; 409:276-289. [PMID: 31029731 DOI: 10.1016/j.neuroscience.2019.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/09/2019] [Accepted: 03/12/2019] [Indexed: 01/15/2023]
Abstract
Creatine (Cr) is a small metabolite with a central role in energy metabolism and mitochondrial function. Creatine deficiency syndromes are inborn errors of Cr metabolism causing Cr depletion in all body tissues and particularly in the nervous system. Patient symptoms involve intellectual disability, language and behavioral disturbances, seizures and movement disorders suggesting that brain cells are particularly sensitive to Cr depletion. Cr deficiency was found to affect metabolic activity and structural abnormalities of mitochondrial organelles; however a detailed analysis of molecular mechanisms linking Cr deficit, energy metabolism alterations and brain dysfunction is still missing. Using a proteomic approach we evaluated the proteome changes of the brain mitochondrial fraction induced by the deletion of the Cr transporter (CrT) in developing mutant mice. We found a marked alteration of the mitochondrial proteomic landscape in the brain of CrT deficient mice, with the overexpression of many proteins involved in energy metabolism and response to oxidative stress. Moreover, our data suggest possible abnormalities of dendritic spines, synaptic function and plasticity, network excitability and neuroinflammatory response. Intriguingly, the alterations occurred in coincidence with the developmental onset of neurological symptoms. Thus, cerebral mitochondrial alterations could represent an early response to Cr deficiency that could be targeted for therapeutic intervention.
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Affiliation(s)
- Laura Giusti
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy; School of Pharmacy, University of Camerino, I-62032 Camerino, Italy
| | - Angelo Molinaro
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy; Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy
| | - Claudia Boldrini
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy
| | - Federica Ciregia
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy; Department of Rheumatology, GIGA Research, Centre Hospitalier Universitaire (CHU) de Liège, B-4000, Liège, Belgium
| | - Serena Lacerenza
- Department of Pharmacy, University of Pisa, I-56126, Pisa, Italy
| | - Maurizio Ronci
- Department of Medical, Oral and Biotechnological Sciences, University G. d'Annunzio of Chieti-Pescara, I-66100, Chieti, Italy
| | - Andrea Urbani
- Institute of Biochemistry and Clinical Chemistry, Catholic university of the sacred heart, I-00168, Rome, Italy
| | - Giovanni Cioni
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy; Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy
| | | | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, I-50135, Florence, Italy; Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy
| | - Antonio Lucacchini
- Department of Clinical and Experimental Medicine, University of Pisa, I-56126, Pisa, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), I-56124, Pisa, Italy; Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy.
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Pazini FL, Cunha MP, Rodrigues ALS. The possible beneficial effects of creatine for the management of depression. Prog Neuropsychopharmacol Biol Psychiatry 2019; 89:193-206. [PMID: 30193988 DOI: 10.1016/j.pnpbp.2018.08.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 08/17/2018] [Accepted: 08/28/2018] [Indexed: 01/23/2023]
Abstract
Depression, a highly prevalent neuropsychiatric disorder worldwide, causes a heavy burden for the society and is associated with suicide risk. The treatment of this disorder remains a challenge, since currently available antidepressants provide a slow and, often, incomplete response and cause several side effects that contribute to diminish the adhesion of patients to treatment. In this context, several nutraceuticals have been investigated regarding their possible beneficial effects for the management of this neuropsychiatric disorder. Creatine stands out as a supplement frequently used for ergogenic purpose, but it also is a neuroprotective compound with potential to treat or mitigate a broad range of central nervous systems diseases, including depression. This review presents preclinical and clinical evidence that creatine may exhibit antidepressant properties. The focus is given on the possible molecular mechanisms underlying its effects based on the results obtained with different animal models of depression. Finally, evidence obtained in animal models of depression addressing the possibility that creatine may produce rapid antidepressant effect, similar to ketamine, are also presented and discussed.
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Affiliation(s)
- Francis L Pazini
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900 Florianópolis, SC, Brazil
| | - Mauricio P Cunha
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900 Florianópolis, SC, Brazil
| | - Ana Lúcia S Rodrigues
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900 Florianópolis, SC, Brazil.
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Repeated Transcranial Magnetic Stimulation-Induced Motor Evoked Potentials Correlate With the Subject-Specific Serum Metabolic Profile of Creatine. J Clin Neurophysiol 2019; 36:229-235. [PMID: 30720554 DOI: 10.1097/wnp.0000000000000568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Transcranial magnetic stimulation-induced motor responses have been considered to mainly reflect the electrophysiological characteristics of the central motor system. However, certain motor phenomena, such as the magnitude of repetition suppression measured with motor evoked potentials (MEPs), could also in part be influenced by metabolic processes in the peripheral muscles and in both the peripheral and central nervous system. Repetition suppression is an inhibitory phenomenon in which the amplitude of MEP decreases in comparison to that of the first MEP in a train of transcranial magnetic stimulation pulses. This study aimed to identify possible metabolic processes influencing repetition suppression. METHODS The metabolic profiles from serum samples and repetition suppression from the right abductor pollicis brevis muscle were measured in 73 subjects (37 female subjects). Repetition suppression was measured using trains of transcranial magnetic stimulation stimuli consisting of 4 identical single pulses at 1-second intervals. The trains were repeated every 20 seconds, and 30 trains were given with a stimulation intensity of 120% of the resting motor threshold of the abductor pollicis brevis. Thus, a total of 120 stimuli were administered. RESULTS The main finding was a significant negative relationship between serum creatine levels and the magnitude of repetition suppression (standardized β coefficient (β) = -0.43; P < 0.001). In other words, higher creatine levels corresponded to a smaller decrement in the MEP amplitude in response to repetition. When MEPs were not repeated, no relationship was observed (β = 0.09; P = 0.454). Creatine is used to form phosphocreatine, which in turn is needed to resynthesize adenosine triphosphate from adenosine diphosphate in situations requiring high amounts of energy in muscles and neural cells. CONCLUSIONS For the first time, this study demonstrated a connection between repeated MEPs and peripheral serum metabolites linked to muscle function. These findings could explain some of the intersubject variability commonly observed in MEPs when the pulses are repeated.
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Bruun TUJ, Sidky S, Bandeira AO, Debray FG, Ficicioglu C, Goldstein J, Joost K, Koeberl DD, Luísa D, Nassogne MC, O'Sullivan S, Õunap K, Schulze A, van Maldergem L, Salomons GS, Mercimek-Andrews S. Treatment outcome of creatine transporter deficiency: international retrospective cohort study. Metab Brain Dis 2018; 33:875-884. [PMID: 29435807 DOI: 10.1007/s11011-018-0197-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 01/29/2018] [Indexed: 12/25/2022]
Abstract
To evaluate the outcome of current treatment for creatine transporter (CRTR) deficiency, we developed a clinical severity score and initiated an international treatment registry. An online questionnaire was completed by physicians following patients with CRTR deficiency on a treatment, including creatine and/or arginine, and/or glycine. Clinical severity score included 1) global developmental delay/intellectual disability; 2) seizures; 3) behavioural disorder. Phenotype scored 1-3 = mild; 4-6 = moderate; and 7-9 = severe. We applied the clinical severity score pre- and on-treatment. Seventeen patients, 14 males and 3 females, from 16 families were included. Four patients had severe, 6 patients had moderate, and 7 patients had a mild phenotype. The phenotype ranged from mild to severe in patients diagnosed at or before 2 years of age or older than 6 years of age. The phenotype ranged from mild to severe in patients with mildly elevated urine creatine to creatinine ratio. Fourteen patients were on the combined creatine, arginine and glycine therapy. On the combined treatment with creatine, arginine and glycine, none of the males showed either deterioration or improvements in their clinical severity score, whereas two females showed improvements in the clinical severity score. Creatine monotherapy resulted in deterioration of the clinical severity score in one male. There seems to be no correlation between phenotype and degree of elevation in urine creatine to creatinine ratio, genotype, or age at diagnosis. Combined creatine, arginine and glycine therapy might have stopped disease progression in males and improved phenotype in females.
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Affiliation(s)
- Theodora U J Bruun
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Sarah Sidky
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
| | - Anabela O Bandeira
- Pediatrics, Metabolic Unit, Centro Materno Infantil do Norte, Centro Hospitalar do Porto, Porto, Portugal
| | | | - Can Ficicioglu
- Department of Pediatrics, Division of Human Genetics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer Goldstein
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, NC, North, USA
| | - Kairit Joost
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Dwight D Koeberl
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, NC, North, USA
| | - Diogo Luísa
- Metabolic Unit - Child Development Center, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
| | - Marie-Cecile Nassogne
- Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Woluwe-Saint-Lambert, Belgium
| | - Siobhan O'Sullivan
- Department of Metabolic Paediatrics, Royal Hospital for Sick Children, Belfast, UK
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Andreas Schulze
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada
- Departments of Paediatrics and Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Saadet Mercimek-Andrews
- Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
- Institute of Medical Sciences, University of Toronto, The Hospital for Sick Children, Toronto, ON, Canada.
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28
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Abstract
Abstract
Background
Creatine transporter deficiency (CTD) is a treatable, X-linked, inborn error of metabolism.
Case characteristics
Two brothers with autism spectrum disorder were diagnosed with CTD at the ages of 17 and 12 years. Both were found to have a previously reported hemizygous p.408delF (c.1216_1218delTTC) deletion mutation.
Outcome
Both patients were given creatine monohydrate, L-arginine, L-glycine and S-adenosylmethionine, which partially improved the behavioral problems.
Message
Serum creatinine levels, creatine peak at brain MR spectroscopy or creatine/creatinine ratio in urine should be evaluated to identify CTD in children with autistic behavior and language disorders.
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29
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Iqbal F, Hoeger H, Lubec G, Bodamer O. Biochemical and behavioral phenotype of AGAT and GAMT deficient mice following long-term Creatine monohydrate supplementation. Metab Brain Dis 2017; 32:1951-1961. [PMID: 28808834 DOI: 10.1007/s11011-017-0092-3] [Citation(s) in RCA: 7] [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: 05/30/2017] [Accepted: 08/11/2017] [Indexed: 10/19/2022]
Abstract
The creatine/phosphocreatine system is essential for cellular phosphate coupled energy storage and production. We investigated the utility of creatine monohydrate supplementation in two different creatine deficient knockout mouse models. Following weaning, female Arginine: Glycine Amidinotransferase (AGAT) and Guanidinoacetate: methyltransferase (GAMT) knockouts and wild type mice were studied based on their genotypes and dietary supplementation (creatine free or 2% creatine monohydrate supplemented diet) for 10 weeks, using a series of behavioral tests and biochemical analyzes. An improved Rota rod performance was observed in both AGAT (p = 0.02) and GAMT knockout mice (p < 0.001) supplemented with 2% creatine. During Morris water maze probe trial, creatine supplemented AGAT knockout mice took less time to reach virtual platform (p = 0.03) and more frequently crossed this area (p = 0.001) than mice on creatine free diet. Similar observations were recorded for GAMT knockout mice. Urinary creatinine concentrations for AGAT (p = 0.001) and GAMT (p = 0.05) knockout mice were increased following creatine supplementation. Creatine supplementation has a potential to improve neuro-muscular coordination, spatial learning in both AGAT and GAMT knockout mice. Long term Creatine supplementation results in increased urine creatinine concentrations indicating improved creatine metabolism in knockout mice.
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Affiliation(s)
- Furhan Iqbal
- Department of Pediatrics and Adolescent Medicine, Laboratory for Inherited Metabolic Disorders, Medical University of Vienna, Vienna, Austria.
- Institute of Pure and Applied Biology, Zoology Division, Bahauddin Zakariya University, Multan, 60800, Pakistan.
| | - Herald Hoeger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Brauhausgasse 34, A-2235, Himberg, Austria
| | - Gurt Lubec
- Department of Pediatrics and Adolescent Medicine, Laboratory for Inherited Metabolic Disorders, Medical University of Vienna, Vienna, Austria
| | - Olaf Bodamer
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
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30
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Magnetic Resonance Spectroscopy and its Clinical Applications: A Review. J Med Imaging Radiat Sci 2017; 48:233-253. [PMID: 31047406 DOI: 10.1016/j.jmir.2017.06.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/30/2017] [Accepted: 06/22/2017] [Indexed: 12/25/2022]
Abstract
In vivo NMR spectroscopy is known as magnetic resonance spectroscopy (MRS). MRS has been applied as both a research and a clinical tool in order to detect visible or nonvisible abnormalities. The adaptability of MRS allows a technique that can probe a wide variety of metabolic uses across different tissues. Although MRS is mostly applied for brain tissue, it can be used for detection, localization, staging, tumour aggressiveness evaluation, and tumour response assessment of breast, prostate, hepatic, and other cancers. In this article, the medical applications of MRS in the brain, including tumours, neural and psychiatric disorder studies, breast, prostate, hepatic, gastrointestinal, and genitourinary investigations have been reviewed.
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31
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Uemura T, Ito S, Ohta Y, Tachikawa M, Wada T, Terasaki T, Ohtsuki S. Abnormal N-Glycosylation of a Novel Missense Creatine Transporter Mutant, G561R, Associated with Cerebral Creatine Deficiency Syndromes Alters Transporter Activity and Localization. Biol Pharm Bull 2017; 40:49-55. [PMID: 28049948 DOI: 10.1248/bpb.b16-00582] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebral creatine deficiency syndromes (CCDSs) are caused by loss-of-function mutations in creatine transporter (CRT, SLC6A8), which transports creatine at the blood-brain barrier and into neurons of the central nervous system (CNS). This results in low cerebral creatine levels, and patients exhibit mental retardation, poor language skills and epilepsy. We identified a novel human CRT gene missense mutation (c.1681 G>C, G561R) in Japanese CCDSs patients. The purpose of the present study was to evaluate the reduction of creatine transport in G561R-mutant CRT-expressing 293 cells, and to clarify the mechanism of its functional attenuation. G561R-mutant CRT exhibited greatly reduced creatine transport activity compared to wild-type CRT (WT-CRT) when expressed in 293 cells. Also, the mutant protein is localized mainly in intracellular membrane fraction, while WT-CRT is localized in plasma membrane. Western blot analysis revealed a 68 kDa band of WT-CRT protein in plasma membrane fraction, while G561R-mutant CRT protein predominantly showed bands at 55, 110 and 165 kDa in crude membrane fraction. The bands of both WT-CRT and G561R-mutant CRT were shifted to 50 kDa by N-glycosidase treatment. Our results suggest that the functional impairment of G561R-mutant CRT was probably caused by incomplete N-linked glycosylation due to misfolding during protein maturation, leading to oligomer formation and changes of cellular localization.
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Affiliation(s)
- Tatsuki Uemura
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University
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32
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Heussinger N, Saake M, Mennecke A, Dörr HG, Trollmann R. Variable White Matter Atrophy and Intellectual Development in a Family With X-linked Creatine Transporter Deficiency Despite Genotypic Homogeneity. Pediatr Neurol 2017; 67:45-52. [PMID: 28065824 DOI: 10.1016/j.pediatrneurol.2016.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 10/02/2016] [Accepted: 10/08/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND The X-linked creatine transporter deficiency (CRTD) caused by an SLC6A8 mutation represents the second most common cause of X-linked intellectual disability. The clinical phenotype ranges from mild to severe intellectual disability, epilepsy, short stature, poor language skills, and autism spectrum disorders. The objective of this study was to investigate phenotypic variability in the context of genotype, cerebral creatine concentration, and volumetric analysis in a family with CRTD. PATIENTS AND METHODS The clinical phenotype and manifestations of epilepsy were assessed in a Caucasian family with CRTD. DNA sequencing and creatine metabolism analysis confirmed the diagnosis. Cerebral magnetic resonance imaging (cMRI) with voxel-based morphometry and magnetic resonance spectroscopy was performed in all family members. RESULTS An SLC6A8 missense mutation (c.1169C>T; p.Pro390Leu, exon 8) was detected in four of five individuals. Both male siblings were hemizygous, the mother and the affected sister heterozygous for the mutation. Structural cMRI was normal, whereas voxel-based morphometry analysis showed reduced white matter volume below the first percentile of the reference population of 290 subjects in the more severely affected boy compared with family members and controls. Normalized creatine concentration differed significantly between the individuals (P < 0.005). CONCLUSIONS There is a broad phenotypic variability in CRTD even in family members with the same mutation. Differences in mental development could be related to atrophy of the subcortical white matter.
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Affiliation(s)
- Nicole Heussinger
- Department of Pediatrics, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany.
| | - Marc Saake
- Department of Radiology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
| | - Angelika Mennecke
- Department of Neuroradiology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
| | - Helmuth-Günther Dörr
- Department of Pediatrics, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
| | - Regina Trollmann
- Department of Pediatrics, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
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33
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Rackayova V, Cudalbu C, Pouwels PJW, Braissant O. Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies. Anal Biochem 2016; 529:144-157. [PMID: 27840053 DOI: 10.1016/j.ab.2016.11.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 10/20/2022]
Abstract
Creatine (Cr) is an important organic compound acting as intracellular high-energy phosphate shuttle and in energy storage. While located in most cells where it plays its main roles in energy metabolism and cytoprotection, Cr is highly concentrated in muscle and brain tissues, in which Cr also appears to act in osmoregulation and neurotransmission. This review discusses the basis of Cr metabolism, synthesis and transport within brain cells. The importance of Cr in brain function and the consequences of its impaired metabolism in primary and secondary Cr deficiencies are also discussed. Cr and phosphocreatine (PCr) in living systems can be well characterized using in vivo magnetic resonance spectroscopy (MRS). This review describes how 1H MRS allows the measurement of Cr and PCr, and how 31P MRS makes it possible to estimate the creatine kinase (CK) rate constant and so detect dynamic changes in the Cr/PCr/CK system. Absolute quantification by MRS using creatine as internal reference is also debated. The use of in vivo MRS to study brain Cr in a non-invasive way is presented, as well as its use in clinical and preclinical studies, including diagnosis and treatment follow-up in patients.
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Affiliation(s)
- Veronika Rackayova
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Petra J W Pouwels
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Olivier Braissant
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, Lausanne, Switzerland.
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34
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Hanna-El-Daher L, Braissant O. Creatine synthesis and exchanges between brain cells: What can be learned from human creatine deficiencies and various experimental models? Amino Acids 2016; 48:1877-95. [PMID: 26861125 DOI: 10.1007/s00726-016-2189-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/27/2016] [Indexed: 12/11/2022]
Abstract
While it has long been thought that most of cerebral creatine is of peripheral origin, the last 20 years has provided evidence that the creatine synthetic pathway (AGAT and GAMT enzymes) is expressed in the brain together with the creatine transporter (SLC6A8). It has also been shown that SLC6A8 is expressed by microcapillary endothelial cells at the blood-brain barrier, but is absent from surrounding astrocytes, raising the concept that the blood-brain barrier has a limited permeability for peripheral creatine. The first creatine deficiency syndrome in humans was also discovered 20 years ago (GAMT deficiency), followed later by AGAT and SLC6A8 deficiencies, all three diseases being characterized by creatine deficiency in the CNS and essentially affecting the brain. By reviewing the numerous and latest experimental studies addressing creatine transport and synthesis in the CNS, as well as the clinical and biochemical characteristics of creatine-deficient patients, our aim was to delineate a clearer view of the roles of the blood-brain and blood-cerebrospinal fluid barriers in the transport of creatine and guanidinoacetate between periphery and CNS, and on the intracerebral synthesis and transport of creatine. This review also addresses the question of guanidinoacetate toxicity for brain cells, as probably found under GAMT deficiency.
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MESH Headings
- Amidinotransferases/deficiency
- Amidinotransferases/genetics
- Amidinotransferases/metabolism
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/metabolism
- Amino Acid Metabolism, Inborn Errors/pathology
- Animals
- Blood-Brain Barrier/metabolism
- Blood-Brain Barrier/pathology
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/metabolism
- Brain Diseases, Metabolic, Inborn/pathology
- Capillaries/metabolism
- Capillaries/pathology
- Creatine/biosynthesis
- Creatine/deficiency
- Creatine/genetics
- Creatine/metabolism
- Developmental Disabilities/genetics
- Developmental Disabilities/metabolism
- Developmental Disabilities/pathology
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Guanidinoacetate N-Methyltransferase/deficiency
- Guanidinoacetate N-Methyltransferase/genetics
- Guanidinoacetate N-Methyltransferase/metabolism
- Humans
- Intellectual Disability/genetics
- Intellectual Disability/metabolism
- Intellectual Disability/pathology
- Language Development Disorders/genetics
- Language Development Disorders/metabolism
- Language Development Disorders/pathology
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/metabolism
- Mental Retardation, X-Linked/pathology
- Movement Disorders/congenital
- Movement Disorders/genetics
- Movement Disorders/metabolism
- Movement Disorders/pathology
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
- Plasma Membrane Neurotransmitter Transport Proteins/metabolism
- Speech Disorders/genetics
- Speech Disorders/metabolism
- Speech Disorders/pathology
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Affiliation(s)
- Layane Hanna-El-Daher
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, 1011, Lausanne, Switzerland
| | - Olivier Braissant
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, 1011, Lausanne, Switzerland.
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35
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Joncquel-Chevalier Curt M, Voicu PM, Fontaine M, Dessein AF, Porchet N, Mention-Mulliez K, Dobbelaere D, Soto-Ares G, Cheillan D, Vamecq J. Creatine biosynthesis and transport in health and disease. Biochimie 2015; 119:146-65. [DOI: 10.1016/j.biochi.2015.10.022] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/27/2015] [Indexed: 12/31/2022]
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36
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A novel SLC6A8 mutation associated with motor dysfunction in a child exhibiting creatine transporter deficiency. Hum Genome Var 2015; 2:15037. [PMID: 27081545 PMCID: PMC4785581 DOI: 10.1038/hgv.2015.37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/13/2015] [Accepted: 08/14/2015] [Indexed: 11/30/2022] Open
Abstract
Creatine transporter (CT) deficiency is an X-linked disorder caused by mutations in the SLC6A8 gene. We describe a clinical, biochemical and molecular examination of a child with X-linked cerebral creatine deficiency. Increased urinary creatine/creatinine ratio, abnormal brain proton magnetic resonance spectroscopy and reduced creatine transport confirmed the clinical diagnosis. SLC6A8 analysis revealed a novel mutation that was hemizygous in the child and not detected in his mother. CT deficiency should be considered in children, especially males, with mental retardation.
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37
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Clark JF, Cecil KM. Diagnostic methods and recommendations for the cerebral creatine deficiency syndromes. Pediatr Res 2015; 77:398-405. [PMID: 25521922 DOI: 10.1038/pr.2014.203] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/15/2014] [Indexed: 12/29/2022]
Abstract
Primary care pediatricians and a variety of specialist physicians strive to define an accurate diagnosis for children presenting with impairment of expressive speech and delay in achieving developmental milestones. Within the past two decades, a group of disorders featuring this presentation have been identified as cerebral creatine deficiency syndromes (CCDS). Patients with these disorders were initially discerned using proton magnetic resonance spectroscopy of the brain within a magnetic resonance imaging (MRI) examination. The objective of this review is to provide the clinician with an overview of the current information available on identifying and treating these conditions. We explain the salient features of creatine metabolism, synthesis, and transport required for normal development. We propose diagnostic approaches for confirming a CCDS diagnosis. Finally, we describe treatment approaches for managing patients with these conditions.
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Affiliation(s)
- Joseph F Clark
- Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Kim M Cecil
- 1] Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio [2] Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio [3] Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio [4] Department of Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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38
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Campos-Bedolla P, Walter FR, Veszelka S, Deli MA. Role of the Blood–Brain Barrier in the Nutrition of the Central Nervous System. Arch Med Res 2014; 45:610-38. [DOI: 10.1016/j.arcmed.2014.11.018] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022]
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39
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Baroncelli L, Alessandrì MG, Tola J, Putignano E, Migliore M, Amendola E, Gross C, Leuzzi V, Cioni G, Pizzorusso T. A novel mouse model of creatine transporter deficiency. F1000Res 2014; 3:228. [PMID: 25485098 PMCID: PMC4243761 DOI: 10.12688/f1000research.5369.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/25/2014] [Indexed: 12/29/2022] Open
Abstract
Mutations in the creatine (Cr) transporter (CrT) gene lead to cerebral creatine deficiency syndrome-1 (CCDS1), an X-linked metabolic disorder characterized by cerebral Cr deficiency causing intellectual disability, seizures, movement and behavioral disturbances, language and speech impairment ( OMIM #300352). CCDS1 is still an untreatable pathology that can be very invalidating for patients and caregivers. Only two murine models of CCDS1, one of which is an ubiquitous knockout mouse, are currently available to study the possible mechanisms underlying the pathologic phenotype of CCDS1 and to develop therapeutic strategies. Given the importance of validating phenotypes and efficacy of promising treatments in more than one mouse model we have generated a new murine model of CCDS1 obtained by ubiquitous deletion of 5-7 exons in the
Slc6a8 gene. We showed a remarkable Cr depletion in the murine brain tissues and cognitive defects, thus resembling the key features of human CCDS1. These results confirm that CCDS1 can be well modeled in mice. This CrT
−/y murine model will provide a new tool for increasing the relevance of preclinical studies to the human disease.
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Affiliation(s)
- Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Pisa, I-56124, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Scientific Institute, Calambrone (Pisa), I-56128, Italy
| | - Jonida Tola
- Institute of Neuroscience, National Research Council (CNR), Pisa, I-56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Pisa, I-56124, Italy
| | - Martina Migliore
- Institute of Neuroscience, National Research Council (CNR), Pisa, I-56124, Italy
| | - Elena Amendola
- Mouse Biology Unit, European Molecular Biology Laboratory (EMBL), Monterotondo (Roma), I-00015, Italy
| | - Cornelius Gross
- Mouse Biology Unit, European Molecular Biology Laboratory (EMBL), Monterotondo (Roma), I-00015, Italy
| | - Vincenzo Leuzzi
- Department of Paediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, Rome, I-00185, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Scientific Institute, Calambrone (Pisa), I-56128, Italy ; Department of Clinical and Experimental Medicine, University of Pisa, Pisa, I-56126, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, National Research Council (CNR), Pisa, I-56124, Italy ; Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence, I-50135, Italy
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40
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van de Kamp JM, Mancini GM, Salomons GS. X-linked creatine transporter deficiency: clinical aspects and pathophysiology. J Inherit Metab Dis 2014; 37:715-33. [PMID: 24789340 DOI: 10.1007/s10545-014-9713-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/27/2014] [Accepted: 04/01/2014] [Indexed: 12/22/2022]
Abstract
Creatine transporter deficiency was discovered in 2001 as an X-linked cause of intellectual disability characterized by cerebral creatine deficiency. This review describes the current knowledge regarding creatine metabolism, the creatine transporter and the clinical aspects of creatine transporter deficiency. The condition mainly affects the brain while other creatine requiring organs, such as the muscles, are relatively spared. Recent studies have provided strong evidence that creatine synthesis also occurs in the brain, leading to the intriguing question of why cerebral creatine is deficient in creatine transporter deficiency. The possible mechanisms explaining the cerebral creatine deficiency are discussed. The creatine transporter knockout mouse provides a good model to study the disease. Over the past years several treatment options have been explored but no treatment has been proven effective. Understanding the pathogenesis of creatine transporter deficiency is of paramount importance in the development of an effective treatment.
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MESH Headings
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/drug therapy
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/pathology
- Animals
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/physiopathology
- Creatine/deficiency
- Creatine/genetics
- Genetic Diseases, X-Linked/genetics
- Humans
- Intellectual Disability/etiology
- Intellectual Disability/genetics
- Membrane Transport Proteins/deficiency
- Membrane Transport Proteins/genetics
- Mental Retardation, X-Linked/complications
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/physiopathology
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
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Affiliation(s)
- Jiddeke M van de Kamp
- Department of Clinical Genetics, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands,
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41
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Dunbar M, Jaggumantri S, Sargent M, Stockler-Ipsiroglu S, van Karnebeek CDM. Treatment of X-linked creatine transporter (SLC6A8) deficiency: systematic review of the literature and three new cases. Mol Genet Metab 2014; 112:259-74. [PMID: 24953403 DOI: 10.1016/j.ymgme.2014.05.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Creatine transporter deficiency (CTD) is an X-linked inborn error of creatine metabolism characterized by reduced intra-cerebral creatine, developmental delay/intellectual disability, (ID), behavioral disturbance, seizures, and hypotonia in individuals harboring mutations in the SLC6A8 gene. Treatment for CTD includes supplementation with creatine, either alone or in combination with creatine precursors (arginine or glycine). Unlike other disorders of creatine metabolism, the efficacy of its treatment remains controversial. METHODS We present our systematic literature review (2001-2013) comprising 7 publications (case series/reports), collectively describing 25 patients who met the inclusion criteria, and 3 additional cases treated at our institution. Definitions were established and extracted data analyzed for cognitive ability, psychiatric and behavioral disturbances, epilepsy, and cerebral proton magnetic resonance spectroscopy measurements at pre- and post-treatment. RESULTS Treatment regimens varied among the 28 cases: 2 patients received creatine-monohydrate supplementation; 7 patients received L-arginine; 2 patients received creatine-monohydrate and L-arginine; and 17 patients received a combination of creatine-monohydrate, L-arginine and glycine. Median treatment duration was 34.6 months (range 3 months-5 years). Level of evidence was IV. A total of 10 patients (36%) demonstrated response to treatment, manifested by either an increase in cerebral creatine, or improved clinical parameters. Seven of the 28 patients had quantified pre- and post-treatment creatine, and it was significantly increased post-treatment. All of the patients with increased cerebral creatine also experienced clinical improvement. In addition, the majority of patients with clinical improvement had detectable cerebral creatine prior to treatment. 90% of the patients who improved were initiated on treatment before nine years of age. CONCLUSIONS Acknowledging the limitations of this systematic review, we conclude that a proportion of CTD patients show amenability to treatment-particularly milder cases with residual brain creatine, and therefore probable residual protein function. We propose systematic screening for CTD in patients with ID, to allow early initiation of treatment, which currently comprises oral creatine, arginine and/or glycine supplementation. Standardized monitoring for safety and evaluation of treatment effects are required in all patients. This study provides effectiveness on currently available treatment, which can be used to discern effectiveness of future interventions (e.g. cyclocreatine).
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Affiliation(s)
- Mary Dunbar
- Division of Pediatric Neurology, Department of Pediatrics, BC Children's Hospital, Vancouver, Canada
| | - Sravan Jaggumantri
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia, Vancouver, Canada; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC), Vancouver, Canada
| | - Michael Sargent
- Department of Radiology, BC Children's Hospital, Vancouver, Canada
| | - Sylvia Stockler-Ipsiroglu
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia, Vancouver, Canada; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC), Vancouver, Canada
| | - Clara D M van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia, Vancouver, Canada; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC), Vancouver, Canada; Centre for Molecular Medicine and Therapeutics, Vancouver, Canada.
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42
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Reid CA, Mullen S, Kim TH, Petrou S. Epilepsy, energy deficiency and new therapeutic approaches including diet. Pharmacol Ther 2014; 144:192-201. [PMID: 24924701 DOI: 10.1016/j.pharmthera.2014.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 05/28/2014] [Indexed: 02/08/2023]
Abstract
Metabolic dysfunction leading to epilepsy is well recognised. Dietary therapy, in particular the ketogenic diet, is now considered an effective option. Recent genetic studies have highlighted the central role that metabolism can play in setting seizure susceptibility. Here we discuss various metabolic disorders implicated in epilepsy focusing on energy deficiency due to genetic and environmental causes. We argue that low, uncompensated brain glucose levels can precipitate seizures. We will also explore mechanisms of disease and therapy in an attempt to identify common metabolic pathways involved in modulating seizure susceptibility. Finally, newer therapeutic approaches based on diet manipulation in the context of energy deficiency are discussed.
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Affiliation(s)
- Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia.
| | - Saul Mullen
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Tae Hwan Kim
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia; Centre for Neural Engineering, The University of Melbourne, Parkville, Melbourne, Australia; Department of Electrical Engineering, The University of Melbourne, Parkville, Melbourne, Australia
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43
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Haas D, Gan-Schreier H, Langhans CD, Anninos A, Haege G, Burgard P, Schulze A, Hoffmann GF, Okun JG. Diagnosis and therapeutic monitoring of inborn errors of creatine metabolism and transport using liquid chromatography–tandem mass spectrometry in urine, plasma and CSF. Gene 2014; 538:188-94. [DOI: 10.1016/j.gene.2014.01.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/18/2013] [Accepted: 01/06/2014] [Indexed: 10/25/2022]
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44
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Hautman ER, Kokenge AN, Udobi KC, Williams MT, Vorhees CV, Skelton MR. Female mice heterozygous for creatine transporter deficiency show moderate cognitive deficits. J Inherit Metab Dis 2014; 37:63-8. [PMID: 23716276 PMCID: PMC7025435 DOI: 10.1007/s10545-013-9619-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/04/2013] [Accepted: 04/30/2013] [Indexed: 11/29/2022]
Abstract
Creatine transporter (CrT) deficiency (CTD) is an X-linked disorder characterized by intellectual disability and speech delay. There have been reports that show female carriers have clinical symptoms. We have created CrT knockout (CrT(-/y)) mice in which males show severe cognitive deficits as a model of this disorder. The purpose of this study was to examine if the female carrier mice show cognitive deficits. Reductions in Cr levels as well as CrT transcript were observed in the brains of the female CrT(+/-) mice. CrT(+/-) mice show hyperactivity and increased latency to find the cued platform in the Morris water maze (MWM). CrT(+/-) female mice showed deficits in MWM hidden platform acquisition but not during reversal testing. Memory deficits on probe trials were observed during both phases. Novel object recognition memory and contextual fear memory were not affected in female CrT(+/-) mice. Female CrT(+/-) mice show moderate cognitive deficits, which is consistent with some of the human data. Female CrT(+/-) mice could prove to be beneficial in further understanding CTD and testing therapeutic approaches.
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Affiliation(s)
- Emily R Hautman
- Division of Neurology, MLC 7044 Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
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45
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Yu H, van Karnebeek C, Sinclair G, Hill A, Cui H, Zhang VW, Wong LJ. Detection of a novel intragenic rearrangement in the creatine transporter gene by next generation sequencing. Mol Genet Metab 2013; 110:465-71. [PMID: 24140398 DOI: 10.1016/j.ymgme.2013.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/26/2013] [Accepted: 09/29/2013] [Indexed: 12/30/2022]
Abstract
Deficiency caused by mutations in the creatine transporter gene (SLC6A8/CT1) is an X-linked form of intellectual disability. The presence of highly homologous pseudogenes and high GC content of SLC6A8 genomic sequence complicates the molecular diagnosis of this disorder. To minimize the pseudogene interference, exons 2 to 13 of SLC6A8 were amplified as a single PCR product using gene-specific long-range PCR (LR-PCR) primers. The GC-rich exon 1 and its flanking intronic sequences were amplified separately in a short fragment under GC-rich conditions and a touchdown PCR program. Traditional Sanger sequence analysis of all coding exons of SLC6A8 from a 3-year-old boy with creatine transporter deficiency did not detect deleterious mutations. The long-range PCR product was used as template followed by massively parallel sequencing (MPS) on HiSeq2000. We were able to detect a tandem duplication involving part of exons 11 and 12 in the SLC6A8 gene. The deduced c.1592_1639dup133 mutation was confirmed to be a hemizygous insertion by targeted genomic DNA and cDNA Sanger sequencing. Combination of deep sequencing technology with long-range PCR revealed a novel intragenic duplication in the SLC6A8 gene, providing a definitive molecular diagnosis of creatine transporter deficiency in a male patient.
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MESH Headings
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/genetics
- Child, Preschool
- Creatine/deficiency
- Creatine/genetics
- Exons
- Gene Duplication
- Genetic Diseases, X-Linked/diagnosis
- Genetic Diseases, X-Linked/genetics
- High-Throughput Nucleotide Sequencing
- Humans
- Intellectual Disability/genetics
- Male
- Mental Retardation, X-Linked/diagnosis
- Mental Retardation, X-Linked/genetics
- Models, Structural
- Molecular Sequence Data
- Mutation
- Nerve Tissue Proteins/genetics
- Pathology, Molecular/methods
- Pedigree
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
- Pseudogenes/genetics
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Affiliation(s)
- Hui Yu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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46
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Trotier-Faurion A, Dézard S, Taran F, Valayannopoulos V, de Lonlay P, Mabondzo A. Synthesis and biological evaluation of new creatine fatty esters revealed dodecyl creatine ester as a promising drug candidate for the treatment of the creatine transporter deficiency. J Med Chem 2013; 56:5173-81. [PMID: 23697594 DOI: 10.1021/jm400545n] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The creatine transporter deficiency is a neurological disease caused by impairment of the creatine transporter SLC6A8, resulting in mental retardation associated with a complete absence of creatine within the brain and cellular energy perturbation of neuronal cells. One of the therapeutic hypotheses was to administer lipophilic creatine derivatives which are (1) thought to have better permeability through the cell membrane and (2) would not rely on the activity of SLC6A8 to penetrate the brain. Here, we synthesized creatine fatty esters through original organic chemistry process. A screening on an in vitro rat primary cell-based blood-brain barrier model and on a rat primary neuronal cells model demonstrated interesting properties of these prodrugs to incorporate into endothelial, astroglial, and neuronal cells according to a structure-activity relationship. Dodecyl creatine ester showed then a 20-fold increase in creatine content in pathological human fibroblasts compared with the endogenous creatine content, stating that it could be a promising drug candidate.
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47
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van de Kamp JM, Betsalel OT, Mercimek-Mahmutoglu S, Abulhoul L, Grünewald S, Anselm I, Azzouz H, Bratkovic D, de Brouwer A, Hamel B, Kleefstra T, Yntema H, Campistol J, Vilaseca MA, Cheillan D, D’Hooghe M, Diogo L, Garcia P, Valongo C, Fonseca M, Frints S, Wilcken B, von der Haar S, Meijers-Heijboer HE, Hofstede F, Johnson D, Kant SG, Lion-Francois L, Pitelet G, Longo N, Maat-Kievit JA, Monteiro JP, Munnich A, Muntau AC, Nassogne MC, Osaka H, Ounap K, Pinard JM, Quijano-Roy S, Poggenburg I, Poplawski N, Abdul-Rahman O, Ribes A, Arias A, Yaplito-Lee J, Schulze A, Schwartz CE, Schwenger S, Soares G, Sznajer Y, Valayannopoulos V, Van Esch H, Waltz S, Wamelink MMC, Pouwels PJW, Errami A, van der Knaap MS, Jakobs C, Mancini GM, Salomons GS. Phenotype and genotype in 101 males with X-linked creatine transporter deficiency. J Med Genet 2013; 50:463-72. [DOI: 10.1136/jmedgenet-2013-101658] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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48
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Abstract
Magnetic resonance spectroscopy (MRS) is a powerful clinical tool for investigating the metabolic characteristics of neurologic diseases. Proton ((1)H)-MRS is the most commonly used and widely available method. In this article, a brief introduction regarding technical issues of (1)H-MRS applied to the study of metabolic diseases is followed by a description of findings in some of the most common entities in this large, heterogeneous group of neurologic disorders. The aim was to provide a focused representation of the most common applications of (1)H-MRS to metabolic disorders in a routine clinical setting.
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Affiliation(s)
- Andrea Rossi
- Pediatric Neuroradiology Unit, Istituto Giannina Gaslini, Genoa 16147, Italy.
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49
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Abstract
The lack of creatine in the central nervous system causes a severe but treatable neurological disease. Three inherited defects, AGAT, GAMT, and CrT deficiency, compromising synthesis and transport of creatine have been discovered recently. Together these so-called creatine deficiency syndromes (CDS) might represent the most frequent metabolic disorders with a primarily neurological phenotype. Patients with CDS present with global developmental delays, mental retardation, speech impairment especially affecting active language, seizures, extrapyramidal movement disorder, and autism spectrum disorder. The two defects in the creatine synthesis, AGAT and GAMT, are autosomal recessive disorders. They can be diagnosed by analysis of the creatine, guanidinoacetate, and creatinine in body fluids. Treatment is available and, especially when introduced in infancy, has a good outcome. The defect of creatine transport, CrT, is an X-linked condition and perhaps the most frequent reasons for X-linked mental retardation. Diagnosis is made by an increased ratio of creatine to creatinine in urine, but successful treatment still needs to be explored. CDS are under-diagnosed because easy to miss in standard diagnostic workup. Because CDS represent a frequent cause of cognitive and neurological impairment that is treatable they warrant consideration in the workup for genetic mental retardation syndromes, for intractable seizure disorders, and for neurological diseases with a predominant lack of active speech.
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Affiliation(s)
- Andreas Schulze
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Research Institute, Hospital for Sick Children and University of Toronto, Toronto, Canada.
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50
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Valayannopoulos V, Bakouh N, Mazzuca M, Nonnenmacher L, Hubert L, Makaci FL, Chabli A, Salomons GS, Mellot-Draznieks C, Brulé E, de Lonlay P, Toulhoat H, Munnich A, Planelles G, de Keyzer Y. Functional and electrophysiological characterization of four non-truncating mutations responsible for creatine transporter (SLC6A8) deficiency syndrome. J Inherit Metab Dis 2013; 36:103-12. [PMID: 22644605 DOI: 10.1007/s10545-012-9495-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 04/24/2012] [Accepted: 05/03/2012] [Indexed: 12/27/2022]
Abstract
Intellectual disability coupled with epilepsy are clinical hallmarks of the creatine (Cr) transporter deficiency syndrome resulting from mutations in the SLC6A8 gene. So far characterization of pathogenic mutations of SLC6A8 has been limited to Cr uptake. The aim of our study was to characterize the electrogenic and pharmacological properties of non truncating SLC6A8 mutations identified in patients presenting variable clinical severity. Electrophysiological and pharmacological properties of four mutants (including two novel ones) were studied in X. laevis oocyte expression system. Creatine uptake was assessed with [(14)C]-Cr in X. laevis and patients' fibroblasts. Subcellular localization was determined by immunofluorescence and western blot. All mutants were properly targeted to the plasma membrane in both systems. Mutations led to the complete loss of both electrogenic and transport activities in X. laevis and Cr uptake in patients' fibroblasts. Among the Cr analogs tested, guanidinopropionate induced an electrogenic activity with the normal SLC6A8 transporter similar to creatine whereas a phosphocreatine derivative, PCr-Mg-CPLX, resulted in partial activity. SLC6A8 mutants displayed no electrogenic activity with all Cr analogs tested in X. laevis oocytes. Although the mutations altered various domains of SLC6A8 Cr uptake and electrogenic properties were completely inhibited and could not be dissociated. Besides the metabolic functions of Cr, the loss of SLC6A8 electrogenic activity, demonstrated here for the first time, may also play a role in the altered brain functions of the patients.
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Affiliation(s)
- Vassili Valayannopoulos
- INSERM U781 and Paris-Descartes University, Necker-Enfants Malades Hospital, 149 rue de Sèvres, 75743 Paris cedex 15, France
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