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Goldstein J, Thomas-Wilson A, Groopman E, Aggarwal V, Bianconi S, Fernandez R, Hart K, Longo N, Liang N, Reich D, Wallis H, Weaver M, Young S, Mercimek-Andrews S. ClinGen variant curation expert panel recommendations for classification of variants in GAMT, GATM and SLC6A8 for cerebral creatine deficiency syndromes. Mol Genet Metab 2024; 142:108362. [PMID: 38452609 DOI: 10.1016/j.ymgme.2024.108362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/09/2024]
Abstract
Cerebral creatine deficiency syndromes (CCDS) are inherited metabolic phenotypes of creatine synthesis and transport. There are two enzyme deficiencies, guanidinoacetate methyltransferase (GAMT), encoded by GAMT and arginine-glycine amidinotransferase (AGAT), encoded by GATM, which are involved in the synthesis of creatine. After synthesis, creatine is taken up by a sodium-dependent membrane bound creatine transporter (CRTR), encoded by SLC6A8, into all organs. Creatine uptake is very important especially in high energy demanding organs such as the brain, and muscle. To classify the pathogenicity of variants in GAMT, GATM, and SLC6A8, we developed the CCDS Variant Curation Expert Panel (VCEP) in 2018, supported by The Clinical Genome Resource (ClinGen), a National Institutes of Health (NIH)-funded resource. We developed disease-specific variant classification guidelines for GAMT-, GATM-, and SLC6A8-related CCDS, adapted from the American College of Medical Genetics/Association of Molecular Pathology (ACMG/AMP) variant interpretation guidelines. We applied specific variant classification guidelines to 30 pilot variants in each of the three genes that have variants associated with CCDS. Our CCDS VCEP was approved by the ClinGen Sequence Variant Interpretation Working Group (SVI WG) and Clinical Domain Oversight Committee in July 2022. We curated 181 variants including 72 variants in GAMT, 45 variants in GATM, and 64 variants in SLC6A8 and submitted these classifications to ClinVar, a public variant database supported by the National Center for Biotechnology Information. Missense variants were the most common variant type in all three genes. We submitted 32 new variants and reclassified 34 variants with conflicting interpretations. We report specific phenotype (PP4) using a points system based on the urine and plasma guanidinoacetate and creatine levels, brain magnetic resonance spectroscopy (MRS) creatine level, and enzyme activity or creatine uptake in fibroblasts ranging from PP4, PP4_Moderate and PP4_Strong. Our CCDS VCEP is one of the first panels applying disease specific variant classification algorithms for an X-linked disease. The availability of these guidelines and classifications can guide molecular genetics and genomic laboratories and health care providers to assess the molecular diagnosis of individuals with a CCDS phenotype.
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Affiliation(s)
- Jennifer Goldstein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Emily Groopman
- Children's National Hospital, 111 Michigan Ave NW, Washington, DC, USA
| | - Vimla Aggarwal
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Simona Bianconi
- Kaiser Permanente, Southern California Permanente Group, CA, USA
| | - Raquel Fernandez
- American College of Medical Genetics and Genomics, Bethesda, MD, USA
| | - Kim Hart
- Newborn Screening Program, Utah Public Health Laboratory, Department of Health and Human Services, Salt Lake City, UT, USA
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | | | - Daniel Reich
- Newborn Screening Program, Utah Public Health Laboratory, Department of Health and Human Services, Salt Lake City, UT, USA
| | - Heidi Wallis
- Association for Creatine Deficiencies, Carlsbad, CA, USA
| | - Meredith Weaver
- American College of Medical Genetics and Genomics, Bethesda, MD, USA
| | - Sarah Young
- Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
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Finezilber Y, Massey C, Radley JA, Murphy E. Arginine:glycine amidinotransferase (AGAT) deficiency: an easy-to-miss treatable adult-onset myopathy. Pract Neurol 2024:pn-2023-003954. [PMID: 38350728 DOI: 10.1136/pn-2023-003954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2023] [Indexed: 02/15/2024]
Abstract
Arginine:glycine amidinotransferase (AGAT) deficiency is an ultrarare disorder of creatine metabolism, presenting with developmental delay, characteristic biochemical findings and muscle weakness. Most known cases have been identified and treated in early childhood. We describe a 27-year-old woman with learning difficulties and significant myopathy who was diagnosed through genetic investigation in adulthood. Treatment with creatine (10-15 g/day) led to a significant and rapid improvement of muscle strength. A literature review of the few reported adult cases confirms that progressive myopathy is a prominent feature that responds well to creatine supplementation. AGAT deficiency, a partially treatable condition, should be considered in the differential diagnosis of a genetic myopathy, particularly in people with developmental delay and progressive myopathy.
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Affiliation(s)
- Yael Finezilber
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, London, UK
| | - Charlotte Massey
- Therapy and Rehabilitation, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jessica A Radley
- London North West Healthcare Regional Genetics Service, Northwick Park Hospital, London, UK
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, London, UK
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Bian X, Zhu J, Jia X, Liang W, Yu S, Li Z, Zhang W, Rao Y. Suggestion of creatine as a new neurotransmitter by approaches ranging from chemical analysis and biochemistry to electrophysiology. eLife 2023; 12:RP89317. [PMID: 38126335 PMCID: PMC10735228 DOI: 10.7554/elife.89317] [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: 12/23/2023] Open
Abstract
The discovery of a new neurotransmitter, especially one in the central nervous system, is both important and difficult. We have been searching for new neurotransmitters for 12 y. We detected creatine (Cr) in synaptic vesicles (SVs) at a level lower than glutamate and gamma-aminobutyric acid but higher than acetylcholine and 5-hydroxytryptamine. SV Cr was reduced in mice lacking either arginine:glycine amidinotransferase (a Cr synthetase) or SLC6A8, a Cr transporter with mutations among the most common causes of intellectual disability in men. Calcium-dependent release of Cr was detected after stimulation in brain slices. Cr release was reduced in Slc6a8 and Agat mutants. Cr inhibited neocortical pyramidal neurons. SLC6A8 was necessary for Cr uptake into synaptosomes. Cr was found by us to be taken up into SVs in an ATP-dependent manner. Our biochemical, chemical, genetic, and electrophysiological results are consistent with the possibility of Cr as a neurotransmitter, though not yet reaching the level of proof for the now classic transmitters. Our novel approach to discover neurotransmitters is to begin with analysis of contents in SVs before defining their function and physiology.
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Affiliation(s)
- Xiling Bian
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Jiemin Zhu
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Xiaobo Jia
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
| | - Wenjun Liang
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
| | - Sihan Yu
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
| | - Zhiqiang Li
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
| | - Wenxia Zhang
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Institute of Molecular Physiology, Shenzhen Bay LaboratoryShenzhenChina
| | - Yi Rao
- Laboratory of Neurochemical Biology, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking UniversityBeijingChina
- Chinese Institute for Brain Research (CIBR)BeijingChina
- Chinese Institutes of Medical Research, Capital Medical UniversityBeijingChina
- Changping Laboratory, Yard 28, Science Park Road, Changping DistrictBeijingChina
- Institute of Molecular Physiology, Shenzhen Bay LaboratoryShenzhenChina
- Research Unit of Medical Neurobiology, Chinese Academy of Medical SciencesBeijingChina
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Libell JL, Lakhani DA, Balar AB, Khan M, Carpenter JS, Joseph JT. Guanidinoacetate N-methyltransferase deficiency: Case report and brief review of the literature. Radiol Case Rep 2023; 18:4331-4337. [PMID: 37808418 PMCID: PMC10550807 DOI: 10.1016/j.radcr.2023.09.026] [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: 08/11/2023] [Revised: 08/29/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Guanidinoacetate N-methyltransferase (GAMT) deficiency is a rare autosomal recessive disorder characterized by a decrease in creatine synthesis, resulting in cerebral creatine deficiency syndrome (CCDS). GAMT deficiency is caused by mutations in the GAMT gene located on chromosome 19, which impairs the conversion of guanidinoacetic acid (GAA) to creatine. The resulting accumulation of the toxic metabolite GAA and the lack of creatine lead to various symptoms, including global developmental delays, behavioral issues, and epilepsy. The gold standard for diagnosis of GAMT deficiency is genetic testing. Treatment options for GAMT deficiency include creatine supplementation, ornithine supplementation, arginine restriction, and sodium benzoate supplementation. These treatment options have been shown to improve movement disorders and epileptic symptoms, but their impact on intellectual and speech development is limited. Early intervention has shown promising results in normalizing neurological development in a minor subgroup of patients. Therefore, there is a growing need for newborn screening techniques to detect GAMT deficiency early and prevent permanent neurological delays. Here we report a case of GAMT deficiency with emphasis on imaging presentation. Our case showed reduced brain parenchyma creatine stores on MR Spectroscopy, which may provide an avenue to aid in early diagnosis.
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Affiliation(s)
- Joshua L. Libell
- School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - Dhairya A. Lakhani
- Department of Radiology, West Virginia University, 1 Medical Center Dr, Morgantown, WV 26506, USA
| | - Aneri B. Balar
- Department of Radiology, West Virginia University, 1 Medical Center Dr, Morgantown, WV 26506, USA
| | - Musharaf Khan
- Department of Radiology, West Virginia University, 1 Medical Center Dr, Morgantown, WV 26506, USA
| | - Jeffrey S. Carpenter
- Department of Radiology, West Virginia University, 1 Medical Center Dr, Morgantown, WV 26506, USA
| | - Joe T. Joseph
- Department of Radiology, West Virginia University, 1 Medical Center Dr, Morgantown, WV 26506, USA
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Post A, Garcia E, Shalaurova I, Matyus SP, González-Delgado JM, Doorenbos CSE, van der Veen Y, Shah SH, Kraus WE, Kremer D, Knobbe TJ, Bakker SJL, Dullaart RPF, Connelly MA. Creatine and creatinine quantified using nuclear magnetic resonance: A method validation study and clinical associations between circulating creatine and fatigue in kidney transplant recipients. Clin Chim Acta 2023; 548:117517. [PMID: 37591418 DOI: 10.1016/j.cca.2023.117517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023]
Abstract
BACKGROUND A potential contributor to fatigue in kidney transplant recipients (KTR) may be impaired creatine homeostasis. We developed and validated a high-throughput NMR assay allowing for simultaneous measurement of circulating creatine and creatinine, and determined plasma creatine and estimated intramuscular creatine concentrations in KTRs, delineated their determinants and explored their associations with self-reported fatigue. METHODS An NMR assay was developed and validated for measurement of circulating creatinine and creatine concentrations. Plasma creatine and creatinine concentrations were measured in 618 KTR. Fatigue was assessed using the checklist individual strength. Associations of creatine parameters with fatigue was assessed using linear mixed effect models. RESULTS The NMR-based assay had good sensitivity, precision and demonstrated linearity across a large range of values. Among KTR, the mean age was 56 ± 13 years, 62% were men and eGFR was 54 ± 18 ml/min/1.73 m2. Plasma creatine concentration was 27 [19-39] µmol/L. Estimated intramuscular creatine concentration was 27 ± 7 mmol/kg. Higher plasma creatine concentration and higher estimated intramuscular creatine concentration were independently associated with a lower total fatigue score and less motivation problems. CONCLUSION An NMR method for measurement of circulating creatine and creatinine which offers the potential for accurate and efficient quantification was developed. The found associations suggest that improving creatine status may play a beneficial role in mitigating fatigue.
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Affiliation(s)
- Adrian Post
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | | | | | | | | | - Caecilia S E Doorenbos
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | - Yvonne van der Veen
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | - Svati H Shah
- Division of Cardiology, Department of Medicine and Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC 27710, USA; Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC 27710, USA.
| | - William E Kraus
- Division of Cardiology, Department of Medicine and Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Daan Kremer
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | - Tim J Knobbe
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | - Stephan J L Bakker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
| | - Robin P F Dullaart
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands.
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Kim DR, Martin S, Desai K. The effects of a comparatively higher dose of 1000 mg/kg/d of oral L- or D-arginine on the L-arginine metabolic pathways in male Sprague-Dawley rats. PLoS One 2023; 18:e0289476. [PMID: 37527267 PMCID: PMC10393177 DOI: 10.1371/journal.pone.0289476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023] Open
Abstract
Oral L-arginine supplements are popular mainly for their nitric oxide mediated vasodilation, but their physiological impact is not fully known. L-arginine is a substrate of several enzymes including arginase, nitric oxide synthase, arginine decarboxylase, and arginine: glycine amidinotransferase (AGAT). We have published a study on the physiological impact of oral L- and D-arginine at 500 mg/kg/day for 4 wks in male Sprague-Dawley rats. We investigated the effects of oral L-arginine and D-arginine at a higher dose of 1000 mg/kg/d for a longer treatment duration of 16 wks in 9-week-old male Sprague-Dawley rats. We measured the expression and activity of L-arginine metabolizing enzymes, and levels of their metabolites in the plasma and various organs. L-arginine did not affect the levels of L-arginine and L-lysine in the plasma and various organs. L-arginine decreased arginase protein expression in the upper small intestine, and arginase activity in the plasma. It also decreased AGAT protein expression in the liver, and creatinine levels in the urine. L-arginine altered arginine decarboxylase protein expression in the upper small intestine and liver, with increased total polyamines plasma levels. Endothelial nitric oxide synthase protein was increased with D-arginine, the presumed metabolically inert isomer, but not L-arginine. In conclusion, oral L-arginine and D-arginine at a higher dose and longer treatment duration significantly altered various enzymes and metabolites in the arginine metabolic pathways, which differed from alterations produced by a lower dose shorter duration treatment published earlier. Further studies with differing doses and duration would allow for a better understanding of oral L-arginine uses, and evidence based safe and effective dose range and duration.
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Affiliation(s)
- Dain Raina Kim
- Department of Anatomy, Physiology & Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Sarah Martin
- Department of Anatomy, Physiology & Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Kaushik Desai
- Department of Anatomy, Physiology & Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
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Meera P, Uusi-Oukari M, Wallner M, Lipshutz GS. Guanidinoacetate (GAA) is a potent GABA A receptor GABA mimetic: Implications for neurological disease pathology. J Neurochem 2023; 165:445-454. [PMID: 36726215 DOI: 10.1111/jnc.15774] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/24/2023] [Accepted: 01/28/2023] [Indexed: 02/03/2023]
Abstract
Impairment of excretion and enzymatic processing of nitrogen, for example, because of liver or kidney failure, or with urea cycle and creatine synthesis enzyme defects, surprisingly leads to primarily neurologic symptoms, yet the exact mechanisms remain largely mysterious. In guanidinoacetate N-methyltransferase (GAMT) deficiency, the guanidino compound guanidinoacetate (GAA) increases dramatically, including in the cerebrospinal fluid (CSF), and has been implicated in mediating the neurological symptoms in GAMT-deficient patients. GAA is synthesized by arginine-glycine amidinotransferase (AGAT), a promiscuous enzyme that not only transfers the amidino group from arginine to glycine, but also to primary amines in, for example, GABA and taurine to generate γ-guanidinobutyric acid (γ-GBA) and guanidinoethanesulfonic acid (GES), respectively. We show that GAA, γ-GBA, and GES share structural similarities with GABA, evoke GABAA receptor (GABAA R) mediated currents (whereas creatine [methylated GAA] and arginine failed to evoke discernible currents) in cerebellar granule cells in mouse brain slices and displace the high-affinity GABA-site radioligand [3 H]muscimol in total brain homogenate GABAA Rs. While γ-GBA and GES are GABA agonists and displace [3 H]muscimol (EC50 /IC50 between 10 and 40 μM), GAA stands out as particularly potent in both activating GABAA Rs (EC50 ~6 μM) and also displacing the GABAA R ligand [3 H]muscimol (IC50 ~3 μM) at pathophysiologically relevant concentrations. These findings stress the role of substantially elevated GAA as a primary neurotoxic agent in GAMT deficiency and we discuss the potential role of GAA in arginase (and creatine transporter) deficiency which show a much more modest increase in GAA concentrations yet share the unique hyperexcitability neuropathology with GAMT deficiency. We conclude that orthosteric activation of GABAA Rs by GAA, and potentially other GABAA R mimetic guanidino compounds (GCs) like γ-GBA and GES, interferes with normal inhibitory GABAergic neurotransmission which could mediate, and contribute to, neurotoxicity.
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Affiliation(s)
- Pratap Meera
- Department of Neurobiology, University of California, Los Angeles, California, USA
| | - Mikko Uusi-Oukari
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Martin Wallner
- Departments of Surgery, University of California, Los Angeles, California, USA
| | - Gerald S Lipshutz
- Departments of Surgery, University of California, Los Angeles, California, USA.,Molecular & Medical Pharmacology, University of California, Los Angeles, California, USA.,Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, California, USA.,Semel Institute for Neuroscience, University of California, Los Angeles, California, USA
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8
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Mustafa NM, Elabd NE, Selim LA, Abdou DM, Griffin JL. Creatine Deficiency Syndromes: Comparison of Screening Methods and Characterization of Four Novel Intronic Variants. Clin Chim Acta 2022; 536:70-76. [PMID: 36130657 DOI: 10.1016/j.cca.2022.09.005] [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: 07/28/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cerebral creatine deficiency syndromes (CCDS) are disorders affecting creatine synthesis or transport. Several methods have been developed to measure creatine and guanidinoacetate (GAA) in different body fluids including methods based on gas chromatography-mass spectrometry (GC-MS) and High-pressure liquid chromatography mass spectrometry (HPLC-MS). The diagnosis of CCDS is then confirmed by sequencing of creatine biosynthesis genes guanidinoacetate methyltransferase (GAMT) and Arginine: glycine amidinotransferase (GATM) and creatine transporter gene solute carrier family 6 member 8 (SLC6A8) or by functional enzymatic assay. The aim of the current study was to find the most reliable and accurate screening method for CCDS by comparing methods using Nuclear Magnetic Resonance spectroscopy (NMR), GC-MS and HPLC-MS. Additionally, this study was performed to estimate the prevalence of CCDS in a cohort of Egyptian patients and potentially to discover novel variants. SUBJECTS AND METHODS The study was conducted on 150 subjects with clinical signs and symptoms consistent with CCDS. Metabolic profiling of urine samples was performed using three techniques: 1) GC-MS 2) Ultra high-pressure (or performance) liquid chromatography - Tandem Mass Spectrometry (UHPLC- MS/MS) and 3) NMR. RESULTS The linearity of peak areas for creatine and GAA by UHPLC-MS/MS and NMR covered and exceeded the ranges normally found in urine. The limit of quantification and the inter-day precision results for creatine and GAA were more robust by UHPLC-MS/MS than NMR. Ten cases were identified as being positive for CCDS by our analytical approaches and underwent next generation sequencing (NGS) for GAMT, GATM and SLC6A8 genes. NGS was performed and confirmed one patient with one likely Pathogenic variant in GAMT gene: (NC_000019.10:g.1401317C > G, NP_000147.1:p.Ala54Pro). Additionally, we describe four novel intronic variants in the GATM gene: c.1043-357del and c.1043-357_1043-356insT, and were predicted to activate cryptic acceptor site with potential alteration of splicing, c.979-227G > A was found to significantly alter the Exon Splice Enhancer (ESE) xon Splice Silencer (ESS) motifs ratio and c.1042 + 262del which was found to have no implications on splicing. CONCLUSIONS Both UHPLC-MS/MS and NMR spectroscopy are comparable to GC-MS in screening for CCDS. Nonetheless, the UHPLC-MS/MS method had better performance than NMR spectroscopy. Additionally, Sequencing of the full length of GATM, GAMT, and SLC6A8 genes is needed to identify intronic variants that could cause CCDS via affecting splice sites.
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Affiliation(s)
- Naira M Mustafa
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK; Department of Chemical Pathology, Faculty of Medicine, Cairo University, Egypt.
| | - Nevine E Elabd
- Department of Chemical Pathology, Faculty of Medicine, Cairo University, Egypt
| | - Laila A Selim
- Department of Paediatrics, Neurology and Metabolic Division, Faculty of Medicine, Cairo University, Egypt; Inherited Metabolic Disease Unit, Centre of Social and Preventive Medicine, Cairo University, Egypt
| | - Doaa M Abdou
- Department of Chemical Pathology, Faculty of Medicine, Cairo University, Egypt
| | - Julian L Griffin
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK; Biomolecular Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College, London, UK; The Rowett Institute, Foresterhill Campus, University of Aberdeen, Aberdeen, UK
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9
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Liu N, Sun Q. Laboratory Diagnosis of Cerebral Creatine Deficiency Syndromes by Determining Creatine and Guanidinoacetate in Plasma and Urine. Methods Mol Biol 2022; 2546:129-140. [PMID: 36127584 DOI: 10.1007/978-1-0716-2565-1_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cerebral creatine deficiency syndromes are caused by the dysfunctional creatine biosynthesis or transport and comprise three hereditary neurodevelopmental defects including arginine-glycine amidinotransferase (AGAT), guanidinoacetate methyltransferase (GAMT), and creatine transporter deficiencies. All conditions are characterized by seizures, intellectual disability, and behavioral abnormalities. Laboratory diagnosis of these disorders relies on the determination of creatine and guanidinoacetate concentrations in both plasma and urine. Here we describe a rapid quantitative UPLC/MS/MS method for the simultaneous determination of these analytes using a normal-phase HILIC column after analyte derivatization. The approach is suitable for neonatal screening follow-ups and monitoring of the treatment for creatine deficiency syndromes.
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Affiliation(s)
- Ning Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics, Houston, TX, USA
| | - Qin Sun
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Baylor Genetics, Houston, TX, USA.
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10
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Whitehead MT, Lai LM, Blüml S. Clinical 1H MRS in childhood neurometabolic diseases — part 2: MRS signatures. Neuroradiology 2022; 64:1111-1126. [DOI: 10.1007/s00234-022-02918-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
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McGinn RJ, Von Stein EL, Summers Stromberg JE, Li Y. Precision medicine in epilepsy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 190:147-188. [DOI: 10.1016/bs.pmbts.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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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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13
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Creatine promotes cancer metastasis through activation of Smad2/3. Cell Metab 2021; 33:1111-1123.e4. [PMID: 33811821 DOI: 10.1016/j.cmet.2021.03.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 02/15/2021] [Accepted: 03/11/2021] [Indexed: 12/24/2022]
Abstract
As one of the most popular nutrient supplements, creatine has been highly used to increase muscle mass and improve exercise performance. Here, we report an adverse effect of creatine using orthotopic mouse models, showing that creatine promotes colorectal and breast cancer metastasis and shortens mouse survival. We show that glycine amidinotransferase (GATM), the rate-limiting enzyme for creatine synthesis, is upregulated in liver metastases. Dietary uptake, or GATM-mediated de novo synthesis of creatine, enhances cancer metastasis and shortens mouse survival by upregulation of Snail and Slug expression via monopolar spindle 1 (MPS1)-activated Smad2 and Smad3 phosphorylation. GATM knockdown or MPS1 inhibition suppresses cancer metastasis and benefits mouse survival by downregulating Snail and Slug. Our findings call for using caution when considering dietary creatine to improve muscle mass or treat diseases and suggest that targeting GATM or MPS1 prevents cancer metastasis, especially metastasis of transforming growth factor beta receptor mutant colorectal cancers.
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14
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Hoytema van Konijnenburg EMM, Wortmann SB, Koelewijn MJ, Tseng LA, Houben R, Stöckler-Ipsiroglu S, Ferreira CR, van Karnebeek CDM. Treatable inherited metabolic disorders causing intellectual disability: 2021 review and digital app. Orphanet J Rare Dis 2021; 16:170. [PMID: 33845862 PMCID: PMC8042729 DOI: 10.1186/s13023-021-01727-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/03/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The Treatable ID App was created in 2012 as digital tool to improve early recognition and intervention for treatable inherited metabolic disorders (IMDs) presenting with global developmental delay and intellectual disability (collectively 'treatable IDs'). Our aim is to update the 2012 review on treatable IDs and App to capture the advances made in the identification of new IMDs along with increased pathophysiological insights catalyzing therapeutic development and implementation. METHODS Two independent reviewers queried PubMed, OMIM and Orphanet databases to reassess all previously included disorders and therapies and to identify all reports on Treatable IDs published between 2012 and 2021. These were included if listed in the International Classification of IMDs (ICIMD) and presenting with ID as a major feature, and if published evidence for a therapeutic intervention improving ID primary and/or secondary outcomes is available. Data on clinical symptoms, diagnostic testing, treatment strategies, effects on outcomes, and evidence levels were extracted and evaluated by the reviewers and external experts. The generated knowledge was translated into a diagnostic algorithm and updated version of the App with novel features. RESULTS Our review identified 116 treatable IDs (139 genes), of which 44 newly identified, belonging to 17 ICIMD categories. The most frequent therapeutic interventions were nutritional, pharmacological and vitamin and trace element supplementation. Evidence level varied from 1 to 3 (trials, cohort studies, case-control studies) for 19% and 4-5 (case-report, expert opinion) for 81% of treatments. Reported effects included improvement of clinical deterioration in 62%, neurological manifestations in 47% and development in 37%. CONCLUSION The number of treatable IDs identified by our literature review increased by more than one-third in eight years. Although there has been much attention to gene-based and enzyme replacement therapy, the majority of effective treatments are nutritional, which are relatively affordable, widely available and (often) surprisingly effective. We present a diagnostic algorithm (adjustable to local resources and expertise) and the updated App to facilitate a swift and accurate workup, prioritizing treatable IDs. Our digital tool is freely available as Native and Web App (www.treatable-id.org) with several novel features. Our Treatable ID endeavor contributes to the Treatabolome and International Rare Diseases Research Consortium goals, enabling clinicians to deliver rapid evidence-based interventions to our rare disease patients.
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Affiliation(s)
| | - Saskia B Wortmann
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria
- On Behalf of United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Marina J Koelewijn
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura A Tseng
- Department of Pediatrics, Amsterdam UMC, Amsterdam, The Netherlands
- On Behalf of United for Metabolic Diseases, Amsterdam, The Netherlands
| | | | - Sylvia Stöckler-Ipsiroglu
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, V6H 3V4, Canada
| | - Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Clara D M van Karnebeek
- Department of Pediatrics, Amsterdam UMC, Amsterdam, The Netherlands.
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
- On Behalf of United for Metabolic Diseases, Amsterdam, The Netherlands.
- Department of Pediatrics - Metabolic Diseases, Amalia Children's Hospital, Geert Grooteplein 10, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands.
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15
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Bonilla DA, Kreider RB, Stout JR, Forero DA, Kerksick CM, Roberts MD, Rawson ES. Metabolic Basis of Creatine in Health and Disease: A Bioinformatics-Assisted Review. Nutrients 2021; 13:nu13041238. [PMID: 33918657 PMCID: PMC8070484 DOI: 10.3390/nu13041238] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/01/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
Creatine (Cr) is a ubiquitous molecule that is synthesized mainly in the liver, kidneys, and pancreas. Most of the Cr pool is found in tissues with high-energy demands. Cr enters target cells through a specific symporter called Na+/Cl−-dependent Cr transporter (CRT). Once within cells, creatine kinase (CK) catalyzes the reversible transphosphorylation reaction between [Mg2+:ATP4−]2− and Cr to produce phosphocreatine (PCr) and [Mg2+:ADP3−]−. We aimed to perform a comprehensive and bioinformatics-assisted review of the most recent research findings regarding Cr metabolism. Specifically, several public databases, repositories, and bioinformatics tools were utilized for this endeavor. Topics of biological complexity ranging from structural biology to cellular dynamics were addressed herein. In this sense, we sought to address certain pre-specified questions including: (i) What happens when creatine is transported into cells? (ii) How is the CK/PCr system involved in cellular bioenergetics? (iii) How is the CK/PCr system compartmentalized throughout the cell? (iv) What is the role of creatine amongst different tissues? and (v) What is the basis of creatine transport? Under the cellular allostasis paradigm, the CK/PCr system is physiologically essential for life (cell survival, growth, proliferation, differentiation, and migration/motility) by providing an evolutionary advantage for rapid, local, and temporal support of energy- and mechanical-dependent processes. Thus, we suggest the CK/PCr system acts as a dynamic biosensor based on chemo-mechanical energy transduction, which might explain why dysregulation in Cr metabolism contributes to a wide range of diseases besides the mitigating effect that Cr supplementation may have in some of these disease states.
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Affiliation(s)
- Diego A. Bonilla
- Research Division, Dynamical Business & Science Society–DBSS International SAS, Bogotá 110861, Colombia
- Research Group in Biochemistry and Molecular Biology, Universidad Distrital Francisco José de Caldas, Bogotá 110311, Colombia
- Research Group in Physical Activity, Sports and Health Sciences (GICAFS), Universidad de Córdoba, Montería 230002, Colombia
- kDNA Genomics, Joxe Mari Korta Research Center, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián, Spain
- Correspondence: ; Tel.: +57-320-335-2050
| | - Richard B. Kreider
- Exercise & Sport Nutrition Laboratory, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA;
| | - Jeffrey R. Stout
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, FL 32816, USA;
| | - Diego A. Forero
- Professional Program in Sport Training, School of Health and Sport Sciences, Fundación Universitaria del Área Andina, Bogotá 111221, Colombia;
| | - Chad M. Kerksick
- Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, Saint Charles, MO 63301, USA;
| | - Michael D. Roberts
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA;
- Edward via College of Osteopathic Medicine, Auburn, AL 36849, USA
| | - Eric S. Rawson
- Department of Health, Nutrition and Exercise Science, Messiah University, Mechanicsburg, PA 17055, USA;
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16
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Bahl S, Cordeiro D, MacNeil L, Schulze A, Mercimek-Andrews S. Urine creatine metabolite panel as a screening test in neurodevelopmental disorders. Orphanet J Rare Dis 2020; 15:339. [PMID: 33267903 PMCID: PMC7709238 DOI: 10.1186/s13023-020-01617-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 11/16/2020] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Cerebral creatine deficiency disorders (CCDD) are inherited metabolic disorders of creatine synthesis and transport. Urine creatine metabolite panel is helpful to identify these disorders. METHODS We reviewed electronic patient charts for all patients that underwent urine creatine metabolite panel testing in the metabolic laboratory at our institution. RESULTS There were 498 tests conducted on 413 patients. Clinical, molecular genetics and neuroimaging features were available in 318 patients. Two new patients were diagnosed with creatine transporter deficiency: one female and one male, both had markedly elevated urine creatine. Urine creatine metabolite panel was also used as a monitoring test in our metabolic laboratory. Diagnostic yield of urine creatine metabolite panel was 0.67% (2/297). There were six known patients with creatine transporter deficiency. The prevalence of creatine transporter deficiency was 2.64% in our study in patients with neurodevelopmental disorders who underwent screening or monitoring of CCDS at our institution. CONCLUSION Even though the diagnostic yield of urine creatine metabolite panel is low, it can successfully detect CCDD patients, despite many neurodevelopmental disorders are not a result of CCDD. To the best of our knowledge, this study is the first Canadian study to report diagnostic yield of urine creatine metabolite panel for CCDD from a single center.
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Affiliation(s)
- Shalini Bahl
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, USA
| | - Dawn Cordeiro
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, USA
| | - Lauren MacNeil
- Metabolic Laboratory, Department of Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, USA.,Department of Medical Genetics, University of Alberta, Edmonton, AB, USA
| | - Andreas Schulze
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, USA.,Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, USA.,Department of Pediatrics, University of Toronto, Toronto, ON, USA
| | - Saadet Mercimek-Andrews
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, USA. .,Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, USA. .,Department of Pediatrics, University of Toronto, Toronto, ON, USA.
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17
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Alessandrì MG, Strigini F, Cioni G, Battini R. Increased creatine demand during pregnancy in Arginine: Glycine Amidino-Transferase deficiency: a case report. BMC Pregnancy Childbirth 2020; 20:506. [PMID: 32883247 PMCID: PMC7469264 DOI: 10.1186/s12884-020-03192-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 08/19/2020] [Indexed: 11/10/2022] Open
Abstract
Background Creatine (Cr), an amino acid derivative, is one of the most important sources of energy acting as both a spatial and temporal energy buffer through its phosphorylated analogue phosphocreatine (PCr) and creatine kinase (CK). Maternal Cr biosynthesis and metabolism seem to play an important role in pregnancy, as shown in preclinical and in healthy human pregnancy studies. Patients with Arginine:Glycine Amidino-Transferase deficiency (AGAT-d), due to the deficit of the first enzyme involved in Cr synthesis, are at a disadvantage due to their failure to synthesize Cr and their dependence on external intake, in contrast to normal subjects, where changes in Cr biosynthesis supply their needs. We report the outcomes of a pregnancy in an AGAT-d woman, and the challenge we faced in managing her treatment with oral Cr to ensure optimal conditions for her fetus. Case presentation A 22-year-old AGAT-d woman referred to our Institute for the management of her first conception at 11 weeks of fetal gestational age. Sonographic monitoring at 20 w GA indicated a reduction of fetal growth, in particular of the head circumference that was below the 3rd centile. Biochemical monitoring of Cr in biological fluids of the mother revealed a decline of the Cr concentrations, in particular in the urine sample, requiring prompt correction of the Cr dose. At 35 weeks of gestation the patient delivered a male infant, heterozygous for GATM mutation, with normal brain Cr levels; at one year the baby achieved typical developmental milestones. Conclusions This rare pregnancy demonstrates that Cr levels in the blood and urine of the mother with AGAT-d decreased since the first months of gestation. The increase of the Cr daily dose administered to the mother seems to have produced beneficial effects also on the fetus.
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Affiliation(s)
- Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Via dei Giacinti 2, 56128, Calambrone - Pisa, Italy.
| | - Francesca Strigini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Via dei Giacinti 2, 56128, Calambrone - Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Via dei Giacinti 2, 56128, Calambrone - Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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18
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Sinha A, Ahmed S, George C, Tsagaris M, Naufer A, von Both I, Tkachyova I, van Eede M, Henkelman M, Schulze A. Magnetic resonance imaging reveals specific anatomical changes in the brain of Agat- and Gamt-mice attributed to creatine depletion and guanidinoacetate alteration. J Inherit Metab Dis 2020; 43:827-842. [PMID: 31951021 DOI: 10.1002/jimd.12215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/30/2019] [Accepted: 01/09/2020] [Indexed: 11/07/2022]
Abstract
Arginine:glycine amidinotransferase- and guanidinoacetate methyltransferase deficiency are severe neurodevelopmental disorders. It is not known whether mouse models of disease express a neuroanatomical phenotype. High-resolution magnetic resonance imaging (MRI) with advanced image analysis was performed in perfused, fixed mouse brains encapsulated with the skull from male, 10-12 week old Agat -exc and B6J.Cg-Gamt tm1Isb mice (n = 48; n = 8 per genotype, strain). T2-weighted MRI scans were nonlinearly aligned to a 3D atlas of the mouse brain with 62 structures identified. Local differences in brain shape related to genotype were assessed by analysis of deformation fields. Creatine (Cr) and guanidinoacetate (GAA) were measured with high-performance liquid chromatography (HPLC) in brain homogenates (n = 24; n = 4 per genotype, strain) after whole-body perfusion. Cr was decreased in the brain of Agat- and Gamt mutant mice. GAA was decreased in Agat-/- and increased in Gamt-/- . Body weight and brain volume were lower in Agat-/- than in Gamt-/- . The analysis of entire brain structures revealed corpus callosum, internal capsule, fimbria and hypothalamus being different between the genotypes in both strains. Eighteen and fourteen significant peaks (local areas of difference in relative size) were found in Agat- and Gamt mutants, respectively. Comparing Agat-/- with Gamt-/- , we found changes in three brain regions, lateral septum, amygdala, and medulla. Intra-strain differences in four brain structures can be associated with Cr deficiency, while the inter-strain differences in three brain structures of the mutant mice may relate to GAA. Correlating these neuroanatomical findings with gene expression data implies the role of Cr metabolism in the developing brain and the importance of early intervention in patients with Cr deficiency syndromes.
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Affiliation(s)
- Ankit Sinha
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sohail Ahmed
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Chris George
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Melina Tsagaris
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Amriya Naufer
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ingo von Both
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ilona Tkachyova
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Matthijs van Eede
- Mouse Imaging Centre, Toronto Center of Phenogenomics, Toronto, Ontario, Canada
| | - Mark Henkelman
- Mouse Imaging Centre, Toronto Center of Phenogenomics, Toronto, Ontario, Canada
- Neurosciences and Mental Health Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Andreas Schulze
- Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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19
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Sun WH, Zhuang DY, Wang Y, Xiao FF, Wu MY, Dong XR, Zhang P, Wang HJ, Zhou WH, Wu BB. [Clinical features and SLC6A8 gene mutations of cerebral creatine deficiency syndrome I: an analysis of two families]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2020; 22:482-487. [PMID: 32434645 PMCID: PMC7389393 DOI: 10.7499/j.issn.1008-8830.2002012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
This article reports the clinical and genetic features of two cases of cerebral creatine deficiency syndrome I (CCDSI) caused by SLC6A8 gene mutations. Both children were boys. Boy 1 (aged 2 years and 10 months) and Boy 2 (aged 8 years and 11 months) had the clinical manifestations of delayed mental and motor development, and convulsion. Their older brothers had the same symptoms. The mother of the boy 1 had mild intellectual disability. The genetic analysis showed two novel homozygous mutations, c.200G>A(p.Gly67Asp) and c.626_627delCT(p.Pro209Argfs*87), in the SLC6A8 gene on the X chromosome, both of which came from their mothers. These two novel mutations were rated as possible pathogenic mutations and were not reported in the literature before. This study expands the mutation spectrum of the SLC6A8 gene and has great significance in the diagnosis of boys with delayed development, and epilepsy.
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Affiliation(s)
- Wei-Hua Sun
- Pediatric Research Institute, Children's Hospital, Fudan University, Shanghai 201102, China.
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20
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Jensen M, Müller C, Schwedhelm E, Arunachalam P, Gelderblom M, Magnus T, Gerloff C, Zeller T, Choe CU. Homoarginine- and Creatine-Dependent Gene Regulation in Murine Brains with l-Arginine:Glycine Amidinotransferase Deficiency. Int J Mol Sci 2020; 21:ijms21051865. [PMID: 32182846 PMCID: PMC7084559 DOI: 10.3390/ijms21051865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/28/2020] [Accepted: 03/07/2020] [Indexed: 12/14/2022] Open
Abstract
l-arginine:glycine amidinotransferase (AGAT) and its metabolites homoarginine (hArg) and creatine have been linked to stroke pathology in both human and mouse studies. However, a comprehensive understanding of the underlying molecular mechanism is lacking. To investigate transcriptional changes in cerebral AGAT metabolism, we applied a transcriptome analysis in brains of wild-type (WT) mice compared to untreated AGAT-deficient (AGAT−/−) mice and AGAT−/− mice with creatine or hArg supplementation. We identified significantly regulated genes between AGAT−/− and WT mice in two independent cohorts of mice which can be linked to amino acid metabolism (Ivd, Lcmt2), creatine metabolism (Slc6a8), cerebral myelination (Bcas1) and neuronal excitability (Kcnip3). While Ivd and Kcnip3 showed regulation by hArg supplementation, Bcas1 and Slc6a8 were creatine dependent. Additional regulated genes such as Pla2g4e and Exd1 need further evaluation of their influence on cerebral function. Experimental stroke models showed a significant regulation of Bcas1 and Slc6a8. Together, these results reveal that AGAT deficiency, hArg and creatine regulate gene expression in the brain, which may be critical in stroke pathology.
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Affiliation(s)
- Märit Jensen
- University Heart and Vascular Centre Hamburg, Clinic for Cardiology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.J.); (C.M.); (T.Z.)
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
| | - Christian Müller
- University Heart and Vascular Centre Hamburg, Clinic for Cardiology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.J.); (C.M.); (T.Z.)
- German Centre for Cardiovascular Research (DZHK e.V.), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany;
| | - Edzard Schwedhelm
- German Centre for Cardiovascular Research (DZHK e.V.), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany;
- Institute of Clinical Pharmacology and Toxicology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Priyadharshini Arunachalam
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
| | - Mathias Gelderblom
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
| | - Tim Magnus
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
| | - Christian Gerloff
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
| | - Tanja Zeller
- University Heart and Vascular Centre Hamburg, Clinic for Cardiology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.J.); (C.M.); (T.Z.)
- German Centre for Cardiovascular Research (DZHK e.V.), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany;
| | - Chi-un Choe
- German Centre for Cardiovascular Research (DZHK e.V.), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany;
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (P.A.); (M.G.); (T.M.); (C.G.)
- Correspondence: ; Tel.: +49-40-7410-53770
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21
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Ostojic SM, Ratgeber L, Olah A, Betlehem J, Acs P. Guanidinoacetic acid deficiency: a new entity in clinical medicine? Int J Med Sci 2020; 17:2544-2550. [PMID: 33029096 PMCID: PMC7532483 DOI: 10.7150/ijms.47757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/10/2020] [Indexed: 02/07/2023] Open
Abstract
Guanidinoacetic acid (GAA, also known as glycocyamine or betacyamine) is a naturally-occurring derivative of glycine and a direct metabolic precursor of creatine, a key player in high-phosphate cellular bioenergetics. GAA is found in human serum and urine, with circulating GAA likely reflects an equilibrium between its endogenous production and utilization/excretion. GAA deficiency (as indicated by low serum GAA) has been reported in various conditions yet this intriguing clinical entity appears to be poorly characterized as yet, either as a primary deficit or a sequel of secondary disease. This minireview article summarizes the inherited and acquired disorders with apparent GAA deficiency and discusses a possible relevance of GAA shortfall in clinical medicine.
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Affiliation(s)
- Sergej M Ostojic
- FSPE Applied Bioenergetics Lab, University of Novi Sad, Novi Sad, Serbia.,Faculty of Health Sciences, University of Pecs, Pecs, Hungary
| | - Laszlo Ratgeber
- Faculty of Health Sciences, University of Pecs, Pecs, Hungary
| | - Andras Olah
- Faculty of Health Sciences, University of Pecs, Pecs, Hungary
| | - Jozsef Betlehem
- Faculty of Health Sciences, University of Pecs, Pecs, Hungary
| | - Pongras Acs
- Faculty of Health Sciences, University of Pecs, Pecs, Hungary
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22
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Xie J, Ji T, Ferreira MAR, Li Y, Patel BN, Rivera RM. Modeling allele-specific expression at the gene and SNP levels simultaneously by a Bayesian logistic mixed regression model. BMC Bioinformatics 2019; 20:530. [PMID: 31660858 PMCID: PMC6819473 DOI: 10.1186/s12859-019-3141-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 10/09/2019] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND High-throughput sequencing experiments, which can determine allele origins, have been used to assess genome-wide allele-specific expression. Despite the amount of data generated from high-throughput experiments, statistical methods are often too simplistic to understand the complexity of gene expression. Specifically, existing methods do not test allele-specific expression (ASE) of a gene as a whole and variation in ASE within a gene across exons separately and simultaneously. RESULTS We propose a generalized linear mixed model to close these gaps, incorporating variations due to genes, single nucleotide polymorphisms (SNPs), and biological replicates. To improve reliability of statistical inferences, we assign priors on each effect in the model so that information is shared across genes in the entire genome. We utilize Bayesian model selection to test the hypothesis of ASE for each gene and variations across SNPs within a gene. We apply our method to four tissue types in a bovine study to de novo detect ASE genes in the bovine genome, and uncover intriguing predictions of regulatory ASEs across gene exons and across tissue types. We compared our method to competing approaches through simulation studies that mimicked the real datasets. The R package, BLMRM, that implements our proposed algorithm, is publicly available for download at https://github.com/JingXieMIZZOU/BLMRM . CONCLUSIONS We will show that the proposed method exhibits improved control of the false discovery rate and improved power over existing methods when SNP variation and biological variation are present. Besides, our method also maintains low computational requirements that allows for whole genome analysis.
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Affiliation(s)
- Jing Xie
- Department of Statistics, University of Missouri at Columbia, Columbia, 65211 MO USA
| | - Tieming Ji
- Department of Statistics, University of Missouri at Columbia, Columbia, 65211 MO USA
| | | | - Yahan Li
- Division of Animal Science, University of Missouri at Columbia, Columbia, 65211 MO USA
| | - Bhaumik N. Patel
- Division of Animal Science, University of Missouri at Columbia, Columbia, 65211 MO USA
| | - Rocio M. Rivera
- Division of Animal Science, University of Missouri at Columbia, Columbia, 65211 MO USA
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Glinton KE, Elsea SH. Untargeted Metabolomics for Autism Spectrum Disorders: Current Status and Future Directions. Front Psychiatry 2019; 10:647. [PMID: 31551836 PMCID: PMC6746843 DOI: 10.3389/fpsyt.2019.00647] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 08/12/2019] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorders (ASDs) are a group of neurodevelopment disorders characterized by childhood onset deficits in social communication and interaction. Although the exact etiology of most cases of ASDs is unknown, a portion has been proposed to be associated with various metabolic abnormalities including mitochondrial dysfunction, disorders of cholesterol metabolism, and folate abnormalities. Targeted biochemical testing like plasma amino acid and acylcarnitine profiles have demonstrated limited utility in helping to diagnose and manage such patients. Untargeted metabolomics has emerged, however, as a promising tool in screening for underlying biochemical abnormalities and managing treatment and as a means of investigating possible novel biomarkers for the disorder. Here, we review the principles and methodology behind untargeted metabolomics, recent pilot studies utilizing this technology, and areas in which it may be integrated into the care of children with this disorder in the future.
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Affiliation(s)
- Kevin E. Glinton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Sarah H. Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
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Li W, Su D, Zhai Q, Chi H, She X, Gao X, Wang K, Yang H, Wang R, Cui B. Proteomes analysis reveals the involvement of autophagy in AD-like neuropathology induced by noise exposure and ApoE4. ENVIRONMENTAL RESEARCH 2019; 176:108537. [PMID: 31228807 DOI: 10.1016/j.envres.2019.108537] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Noise is one of the most important environmental health hazards for humans. Environmental noise or apolipoprotein ε4 (ApoE4) can cause typical Alzheimer's disease (AD)-like pathological changes, which is characterized by progressive cognitive decline and neurodegenerative lesions. Gene-environment interactions may accelerate cognitive decline and increase AD risk. However, there is limited experimental evidence regarding the underlying mechanisms of noise-ApoE4 interactions and AD, which may be closely related to AD development. METHODS In this study, we investigated the combined effects of chronic noise exposure and the ApoE4 gene activation on hippocampus by using proteomics and differentially expressed proteins were found through performed gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, we assessed the changes in adult hippocampal neurogenesis and potential underlying mechanism for AD-like neuropathology. RESULTS Relative to control rats, combined exposure of noise and ApoE4 synergistically increased the characteristic pathological amyloid β-protein of AD-like neuropathology changes in hippocampus. The research identifies a total of 4147 proteins and 15 differentially expressed proteins in hippocampus. Furthermore, comparison of several of the diverse key pathways studied (e.g., PI3K/AKT, insulin, calpain-CDK5, and mammalian target of rapamycin (mTOR) signaling pathways) help to articulate the different mechanisms involved in combined effects of noise and ApoE4 on AD-like pathology. We verified four selected proteins, namely, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins. Validation data shows significant effects of chronic noise and ApoE4 on the expression of four selected proteins, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins, and mTOR and autophagy-related proteins, which share significant interaction effect of chronic noise and ApoE4. CONCLUSION Gene-environment interactions between chronic noise and ApoE4 activate the mTOR signaling, decrease autophagy, and facilitate AD-like changes in the hippocampus. Thus, our findings may help elucidate the role of gene-environment interactions in AD development.
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Affiliation(s)
- Wenlong Li
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Donghong Su
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; Shandong Academy of Occupational Health and Occupational Medicine, Shandong Academy of Medical Sciences, Jinan, China
| | - Qingfeng Zhai
- School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Huimin Chi
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Xiaojun She
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiujie Gao
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Kun Wang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Honglian Yang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Rui Wang
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong Academy of Medical Sciences, Jinan, China
| | - Bo Cui
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.
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25
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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: 12] [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: 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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Creatine is a Conditionally Essential Nutrient in Chronic Kidney Disease: A Hypothesis and Narrative Literature Review. Nutrients 2019; 11:nu11051044. [PMID: 31083291 PMCID: PMC6567063 DOI: 10.3390/nu11051044] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/23/2019] [Accepted: 05/08/2019] [Indexed: 12/15/2022] Open
Abstract
To accommodate the loss of the plethora of functions of the kidneys, patients with chronic kidney disease require many dietary adjustments, including restrictions on the intake of protein, phosphorus, sodium and potassium. Plant-based foods are increasingly recommended as these foods contain smaller amounts of saturated fatty acids, protein and absorbable phosphorus than meat, generate less acid and are rich in fibers, polyunsaturated fatty acids, magnesium and potassium. Unfortunately, these dietary recommendations cannot prevent the occurrence of many symptoms, which typically include fatigue, impaired cognition, myalgia, muscle weakness, and muscle wasting. One threat coming with the recommendation of low-protein diets in patients with non-dialysis-dependent chronic kidney disease (CKD) and with high-protein diets in patients with dialysis-dependent CKD, particularly with current recommendations towards proteins coming from plant-based sources, is that of creatine deficiency. Creatine is an essential contributor in cellular energy homeostasis, yet on a daily basis 1.6–1.7% of the total creatine pool is degraded. As the average omnivorous diet cannot fully compensate for these losses, the endogenous synthesis of creatine is required for continuous replenishment. Endogenous creatine synthesis involves two enzymatic steps, of which the first step is a metabolic function of the kidney facilitated by the enzyme arginine:glycine amidinotransferase (AGAT). Recent findings strongly suggest that the capacity of renal AGAT, and thus endogenous creatine production, progressively decreases with the increasing degree of CKD, to become absent or virtually absent in dialysis patients. We hypothesize that with increasing degree of CKD, creatine coming from meat and dairy in food increasingly becomes an essential nutrient. This phenomenon will likely be present in patients with CKD stages 3, 4 and 5, but will likely be most pronouncedly present in patients with dialysis-dependent CKD, because of the combination of lowest endogenous production of creatine and unopposed losses of creatine into the dialysate. It is likely that these increased demands for dietary creatine are not sufficiently met. The result of which, may be a creatine deficiency with important contributions to the sarcopenia, fatigue, impaired quality of life, impaired cognition, and premature mortality seen in CKD.
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Balestrino M, Adriano E. Beyond sports: Efficacy and safety of creatine supplementation in pathological or paraphysiological conditions of brain and muscle. Med Res Rev 2019; 39:2427-2459. [PMID: 31012130 DOI: 10.1002/med.21590] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 03/26/2019] [Accepted: 04/02/2019] [Indexed: 01/16/2023]
Abstract
Creatine is pivotal in energy metabolism of muscle and brain cells, both in physiological and in pathological conditions. Additionally, creatine facilitates the differentiation of muscle and neuronal cells. Evidence of effectiveness of creatine supplementation in improving several clinical conditions is now substantial, and we review it in this paper. In hereditary diseases where its synthesis is impaired, creatine has a disease-modifying capacity, especially when started soon after birth. Strong evidence, including a Cochrane meta-analysis, shows that it improves muscular strength and general well-being in muscular dystrophies. Significant evidence exists also of its effectiveness in secondary prevention of statin myopathy and of treatment-resistant depression in women. Vegetarians and vegans do not consume any dietary creatine and must synthesize all they need, spending most of their methylation capacity. Nevertheless, they have a lower muscular concentration of creatine. Creatine supplementation has proved effective in increasing muscular and neuropsychological performance in vegetarians or vegans and should, therefore, be recommended especially in those of them who are athletes, heavy-duty laborers or who undergo intense mental effort. Convincing evidence also exists of creatine effectiveness in muscular atrophy and sarcopenia in the elderly, and in brain energy shortage (mental fatigue, sleep deprivation, environmental hypoxia as in mountain climbing, and advanced age). Furthermore, we review more randomized, placebo-controlled trials showing that creatine supplementation is safe up to 20 g/d, with a possible caveat only in people with kidney disease. We trust that the evidence we review will be translated into clinical practice and will spur more research on these subjects.
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Affiliation(s)
- Maurizio Balestrino
- Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), University of Genova, Genova, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Enrico Adriano
- Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), University of Genova, Genova, Italy
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28
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P4 medicine for epilepsy and intellectual disability: nutritional therapy for inherited metabolic disease. Emerg Top Life Sci 2019; 3:75-95. [PMID: 33523196 DOI: 10.1042/etls20180180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/20/2019] [Accepted: 02/25/2019] [Indexed: 12/16/2022]
Abstract
Early identification and treatment of inherited metabolic diseases (IMDs) are essential to prevent and minimize intellectual disability (ID) and epilepsy. The oldest form of treatment, nutritional modulation, has proved beneficial for many IMDs. These conditions represent a promising model for P4 medicine - predictive, preventive, personalized, and participatory - specifically through the interpretation of individual genetic, pathophysiological, and clinical characteristics. More than 1000 IMDs have been described, and for these different nutritional modulation strategies are applied, varying from substrate reduction, supplementation of vitamins for catalyzation of enzymatic reactions or supplementation of amino acids or other nutrients, to substitution for deficient or inactivated products. This review provides an overview of all IMDs presenting with epilepsy and/or ID amenable to nutritional modulation; these are 85 in number, belonging to 27 categories. Therapeutic strategies include protein-restricted diet, ketogenic diet, fat-restricted diet, lactose-restricted diet; supplementation of amino acids, carbohydrates, or others; and supplementation of vitamins or cofactors as well as a sick-day protocol. Nutritional therapies are generally safe, affordable, and accessible, but compliance is an issue. Three different types of response exist: (1) a positive effect on seizure control and/or psychomotor development; (2) efficacy in prevention of decompensation but ongoing damage occurs; and (3) insufficient insights or evidence to establish the treatment as effective. For the latter category, we describe pyridoxine-dependent epilepsy as a case vignette for P4 medicine, discuss the benefits and challenges of nutritional modulation in IMDs, and outline novel approaches and solutions.
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29
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Nazari-Ghadikolaei A, Mehrabani-Yeganeh H, Miarei-Aashtiani SR, Staiger EA, Rashidi A, Huson HJ. Genome-Wide Association Studies Identify Candidate Genes for Coat Color and Mohair Traits in the Iranian Markhoz Goat. Front Genet 2018; 9:105. [PMID: 29670642 PMCID: PMC5893768 DOI: 10.3389/fgene.2018.00105] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/16/2018] [Indexed: 12/31/2022] Open
Abstract
The Markhoz goat provides an opportunity to study the genetics underlying coat color and mohair traits of an Angora type goat using genome-wide association studies (GWAS). This indigenous Iranian breed is valued for its quality mohair used in ceremonial garments and has the distinction of exhibiting an array of coat colors including black, brown, and white. Here, we performed 16 GWAS for different fleece (mohair) traits and coat color in 228 Markhoz goats sampled from the Markhoz Goat Research Station in Sanandaj, Kurdistan province, located in western Iran using the Illumina Caprine 50K beadchip. The Efficient Mixed Model Linear analysis was used to identify genomic regions with potential candidate genes contributing to coat color and mohair characteristics while correcting for population structure. Significant associations to coat color were found within or near the ASIP, ITCH, AHCY, and RALY genes on chromosome 13 for black and brown coat color and the KIT and PDGFRA genes on chromosome 6 for white coat color. Individual mohair traits were analyzed for genetic association along with principal components that allowed for a broader perspective of combined traits reflecting overall mohair quality and volume. A multitude of markers demonstrated significant association to mohair traits highlighting potential candidate genes of POU1F1 on chromosome 1 for mohair quality, MREG on chromosome 2 for mohair volume, DUOX1 on chromosome 10 for yearling fleece weight, and ADGRV1 on chromosome 7 for grease percentage. Variation in allele frequencies and haplotypes were identified for coat color and differentiated common markers associated with both brown and black coat color. This demonstrates the potential for genetic markers to be used in future breeding programs to improve selection for coat color and mohair traits. Putative candidate genes, both novel and previously identified in other species or breeds, require further investigation to confirm phenotypic causality and potential epistatic relationships.
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Affiliation(s)
- Anahit Nazari-Ghadikolaei
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Hassan Mehrabani-Yeganeh
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Seyed R. Miarei-Aashtiani
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | | | - Amir Rashidi
- Department of Animal Science, Faculty of Agriculture Engineering, University of Kurdistan, Sanandaj, Iran
| | - Heather J. Huson
- Department of Animal Science, Cornell University, Ithaca, NY, United States
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30
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Adeva-Andany M, Souto-Adeva G, Ameneiros-Rodríguez E, Fernández-Fernández C, Donapetry-García C, Domínguez-Montero A. Insulin resistance and glycine metabolism in humans. Amino Acids 2017; 50:11-27. [PMID: 29094215 DOI: 10.1007/s00726-017-2508-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/27/2017] [Indexed: 12/27/2022]
Abstract
Plasma glycine level is low in patients with obesity or diabetes and the improvement of insulin resistance increases plasma glycine concentration. In prospective studies, hypoglycinemia at baseline predicts the risk of developing type 2 diabetes and higher serum glycine level is associated with decreased risk of incident type 2 diabetes. Consistently, plasma glycine concentration is lower in the lean offspring of parents with type 2 diabetes compared to healthy subjects. Among patients with type 2 diabetes, hypoglycinemia occurs before clinical manifestations of the disease, but the pathophysiological mechanisms underlying glycine deficit and its potential clinical repercussions are unclear. Glycine participates in several metabolic pathways, being required for relevant human physiological processes. Humans synthesize glycine from glyoxylate, glucose (via serine), betaine and likely from threonine and during the endogenous synthesis of L-carnitine. Glycine conjugates bile acids and other acyl moieties producing acyl-glycine derivatives. The glycine cleavage system catalyzes glycine degradation to carbon dioxide and ammonium while tetrahydrofolate is converted into 5,10-methylene-tetrahydrofolate. Glycine is utilized to synthesize serine, sarcosine, purines, creatine, heme group, glutathione, and collagen. Glycine is a major quantitative component of collagen. In addition, the role of glycine maintaining collagen structure is critical, as glycine residues are required to stabilize the triple helix of the collagen molecule. This quality of glycine likely contributes to explain the occurrence of medial arterial calcification and the elevated cardiovascular risk associated with diabetes and chronic kidney disease, as emerging evidence links normal collagen content with the initiation and progression of vascular calcification in humans.
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Affiliation(s)
- M Adeva-Andany
- Internal Medicine Department, Hospital General Juan Cardona, c/Pardo Bazán s/n, 15406, Ferrol, Spain.
| | - G Souto-Adeva
- National Institutes of Health, National Institute of Arthritis and Metabolic Diseases, Bethesda, USA
| | - E Ameneiros-Rodríguez
- Internal Medicine Department, Hospital General Juan Cardona, c/Pardo Bazán s/n, 15406, Ferrol, Spain
| | - C Fernández-Fernández
- Internal Medicine Department, Hospital General Juan Cardona, c/Pardo Bazán s/n, 15406, Ferrol, Spain
| | - C Donapetry-García
- Internal Medicine Department, Hospital General Juan Cardona, c/Pardo Bazán s/n, 15406, Ferrol, Spain
| | - A Domínguez-Montero
- Internal Medicine Department, Hospital General Juan Cardona, c/Pardo Bazán s/n, 15406, Ferrol, Spain
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31
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Ostojic SM. Benefits and drawbacks of guanidinoacetic acid as a possible treatment to replenish cerebral creatine in AGAT deficiency. Nutr Neurosci 2017; 22:302-305. [PMID: 28971744 DOI: 10.1080/1028415x.2017.1385176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Arginine-glycine amidinotransferase (AGAT) deficiency is a rare inherited metabolic disorder that severely affects brain bioenergetics. Characterized by mental retardation, language impairment, and behavioral disorders, AGAT deficiency is a treatable condition, where long-term creatine supplementation usually restores brain creatine levels and improves its clinical features. In some cases of AGAT deficiency, creatine treatment might be somewhat limited due to possible shortcomings in performance and transport of creatine to the brain. Guanidinoacetic acid (GAA), a direct metabolic precursor of creatine, has recently been suggested as a possible alternative to creatine to tackle brain creatine levels in experimental medicine. AGAT patients might benefit from oral GAA due to upgraded bioavailability and convenient utilization of the compound, while possible drawbacks (e.g. brain methylation issues, neurotoxicity, and hyperhomocysteinemia) should be accounted as well.
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Affiliation(s)
- Sergej M Ostojic
- a Applied Bioenergetics Lab, Faculty of Sport and PE , University of Novi Sad , Lovcenska 16, Novi Sad 21000 , Serbia.,b University of Belgrade School of Medicine , Belgrade , Serbia
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32
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Battini R, Alessandrì MG, Casalini C, Casarano M, Tosetti M, Cioni G. Fifteen-year follow-up of Italian families affected by arginine glycine amidinotransferase deficiency. Orphanet J Rare Dis 2017; 12:21. [PMID: 28148286 PMCID: PMC5289057 DOI: 10.1186/s13023-017-0577-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 01/20/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Arginine:glycine amidinotransferase deficiency (AGAT-d) is a very rare inborn error of creatine synthesis mainly characterized by absence of brain Creatine (Cr) peak, intellectual disability, severe language impairment and behavioural disorder and susceptible to supplementary Cr treatment per os. Serial examinations by magnetic resonance spectroscopy are required to evaluate Cr recovery in brain during treatment of high doses of Cr per os, which have been proved beneficial and effective in treating main clinical symptoms. A long term study with detailed reports on clinical, neurochemical and neuropsychological outcomes of the first Italian patients affected by AGAT-d here reported can represent a landmark in management of this disorder thus enhancing medical knowledge and clinical practice. RESULTS We have evaluated the long term effects of Cr supplementation management in four Italian patients affected by AGAT-d, correlating specific treatments with serial clinical, biochemical and magnetic resonance spectroscopy examinations as well as the neuropsychological outcome by standardized developmental scales. Consecutive MRS examinations have confirmed that Cr depletion in AGAT-d patients is reversible under Cr supplementation. Cr treatment is considered safe and well tolerated but side effects, including weight gain and kidney stones, have been reported. CONCLUSIONS Early treatment prevents adverse developmental outcome, while patients diagnosed and treated at an older age showed partial but significant cognitive recovery with clear improvements in adaptive functioning.
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Affiliation(s)
- Roberta Battini
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, Calambrone, 56128, Pisa, Italy.
| | - M Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, Calambrone, 56128, Pisa, Italy
| | - Claudia Casalini
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, Calambrone, 56128, Pisa, Italy
| | - Manuela Casarano
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, Calambrone, 56128, Pisa, Italy
| | - Michela Tosetti
- Department of Developmental Neuroscience, MRI Laboratory, IRCCS Fondazione Stella Maris, Calambrone, Pisa, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, Calambrone, 56128, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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33
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Laboratory diagnosis of creatine deficiency syndromes: a technical standard and guideline of the American College of Medical Genetics and Genomics. Genet Med 2017; 19:256-263. [PMID: 28055022 DOI: 10.1038/gim.2016.203] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 11/11/2016] [Indexed: 01/29/2023] Open
Abstract
Disclaimer: These ACMG Standards and Guidelines are intended as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily assure a successful medical outcome. These Standards and Guidelines should not be considered inclusive of all proper procedures and tests or exclusive of others that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, clinical laboratory geneticists should apply their professional judgment to the specific circumstances presented by the patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient's record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these Standards and Guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Cerebral creatine deficiency syndromes are neurometabolic conditions characterized by intellectual disability, seizures, speech delay, and behavioral abnormalities. Several laboratory methods are available for preliminary and confirmatory diagnosis of these conditions, including measurement of creatine and related metabolites in biofluids using liquid chromatography-tandem mass spectrometry or gas chromatography-mass spectrometry, enzyme activity assays in cultured cells, and DNA sequence analysis. These guidelines are intended to standardize these procedures to help optimize the diagnosis of creatine deficiency syndromes. While biochemical methods are emphasized, considerations for confirmatory molecular testing are also discussed, along with variables that influence test results and interpretation.Genet Med 19 2, 256-263.
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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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Ostojic SM, Ostojic J, Drid P, Vranes M. Guanidinoacetic acid versus creatine for improved brain and muscle creatine levels: a superiority pilot trial in healthy men. Appl Physiol Nutr Metab 2016; 41:1005-7. [DOI: 10.1139/apnm-2016-0178] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this randomized, double-blind, crossover trial, we evaluated whether 4-week supplementation with guanidinoacetic acid (GAA) is superior to creatine in facilitating creatine levels in healthy men (n = 5). GAA (3.0 g/day) resulted in a more powerful rise (up to 16.2%) in tissue creatine levels in vastus medialis muscle, middle-cerebellar peduncle, and paracentral grey matter, as compared with creatine (P < 0.05). These results indicate that GAA as a preferred alternative to creatine for improved bioenergetics in energy-demanding tissues.
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Affiliation(s)
- Sergej M. Ostojic
- Applied Bioenergetics Lab, Biomedical Sciences Department, Faculty of Sport and Physical Education, University of Novi Sad, Lovcenska 16, Novi Sad 21000, Serbia
- University of Belgrade School of Medicine, Belgrade, Serbia
| | - Jelena Ostojic
- University Clinical Center of Vojvodina, Novi Sad, Serbia
| | - Patrik Drid
- Applied Bioenergetics Lab, Biomedical Sciences Department, Faculty of Sport and Physical Education, University of Novi Sad, Lovcenska 16, Novi Sad 21000, Serbia
| | - Milan Vranes
- Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
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DesRoches CL, Bruun T, Wang P, Marshall CR, Mercimek-Mahmutoglu S. Arginine-Glycine Amidinotransferase Deficiency and Functional Characterization of Missense Variants inGATM. Hum Mutat 2016; 37:926-32. [DOI: 10.1002/humu.23018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/03/2016] [Accepted: 05/19/2016] [Indexed: 01/22/2023]
Affiliation(s)
- Caro-Lyne DesRoches
- Genetics and Genome Biology Program; Research Institute; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
| | - Theodora Bruun
- Genetics and Genome Biology Program; Research Institute; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
| | - Peixiang Wang
- Genetics and Genome Biology Program; Research Institute; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
| | - Christian R. Marshall
- Genetics and Genome Biology Program; Research Institute; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
- Genome Diagnostics; Department of Paediatric Laboratory Medicine; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
| | - Saadet Mercimek-Mahmutoglu
- Genetics and Genome Biology Program; Research Institute; The Hospital for Sick Children; Toronto Ontario M5G 1×8 Canada
- Division of Clinical and Metabolic Genetics; Department of Pediatrics; The Hospital for Sick Children; University of Toronto; Toronto Ontario M5G 1×8 Canada
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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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