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Bernardino Gomes TM, Vincent AE, Menger KE, Stewart JB, Nicholls TJ. Mechanisms and pathologies of human mitochondrial DNA replication and deletion formation. Biochem J 2024; 481:683-715. [PMID: 38804971 DOI: 10.1042/bcj20230262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024]
Abstract
Human mitochondria possess a multi-copy circular genome, mitochondrial DNA (mtDNA), that is essential for cellular energy metabolism. The number of copies of mtDNA per cell, and their integrity, are maintained by nuclear-encoded mtDNA replication and repair machineries. Aberrant mtDNA replication and mtDNA breakage are believed to cause deletions within mtDNA. The genomic location and breakpoint sequences of these deletions show similar patterns across various inherited and acquired diseases, and are also observed during normal ageing, suggesting a common mechanism of deletion formation. However, an ongoing debate over the mechanism by which mtDNA replicates has made it difficult to develop clear and testable models for how mtDNA rearrangements arise and propagate at a molecular and cellular level. These deletions may impair energy metabolism if present in a high proportion of the mtDNA copies within the cell, and can be seen in primary mitochondrial diseases, either in sporadic cases or caused by autosomal variants in nuclear-encoded mtDNA maintenance genes. These mitochondrial diseases have diverse genetic causes and multiple modes of inheritance, and show notoriously broad clinical heterogeneity with complex tissue specificities, which further makes establishing genotype-phenotype relationships challenging. In this review, we aim to cover our current understanding of how the human mitochondrial genome is replicated, the mechanisms by which mtDNA replication and repair can lead to mtDNA instability in the form of large-scale rearrangements, how rearranged mtDNAs subsequently accumulate within cells, and the pathological consequences when this occurs.
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Affiliation(s)
- Tiago M Bernardino Gomes
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- NHS England Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Amy E Vincent
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Katja E Menger
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - James B Stewart
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
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2
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Guo Y, Kang Y, Bai W, Liu Q, Zhang R, Wang Y, Wang C. Perinatal exposure to bisphenol A impairs cognitive function via the gamma-aminobutyric acid signaling pathway in male rat offspring. ENVIRONMENTAL TOXICOLOGY 2024; 39:1235-1244. [PMID: 37926988 DOI: 10.1002/tox.24007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 08/17/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023]
Abstract
Bisphenol A (BPA) is a common synthetic endocrine disruptor that can be utilized in the fabrication of materials such as polycarbonates and epoxy resins. Numerous studies have linked BPA to learning and memory problems, although the precise mechanism remains unknown. Gamma-aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the vertebrate central nervous system, and it is intimately related to learning and memory. This study aims to evaluate whether altered cognitive behavior involves the GABA signaling pathway in male offspring of rats exposed to BPA during the prenatal and early postnatal periods. Pregnant rats were orally given BPA (0, 0.04, 0.4, and 4 mg/kg body weight (BW)/day) from the first day of pregnancy to the 21st day of breastfeeding. Three-week-old male rat offspring were selected for an open-field experiment and a new object recognition experiment to evaluate the effect of BPA exposure on cognitive behavior. Furthermore, the role of GABA signaling markers in the cognition affected by BPA was investigated at the molecular level using western blotting and real-time polymerase chain reaction (RT-PCR). The research demonstrated that BPA exposure impacted the behavior and memory of male rat offspring and elevated the expression of glutamic acid decarboxylase 67 (GAD67), GABA type A receptors subunit (GABAARα1), and GABA vesicle transporter (VGAT) in the hippocampus while decreasing the expression levels of GABA transaminase (GABA-T) and GABA transporter 1 (GAT-1). These findings indicate that the alteration in the expression of GABA signaling molecules may be one of the molecular mechanisms by which perinatal exposure to BPA leads to decreased learning and memory in male rat offspring.
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Affiliation(s)
- Yi Guo
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Yuxin Kang
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Wenjie Bai
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Qiling Liu
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Rongqiang Zhang
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Yuxin Wang
- College of Health Public, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
| | - Chong Wang
- Medical Experiment Center, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China
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Xu S, Neupane S, Wang H, Pham TP, Snyman M, Huynh TV, Wang L. Efficient CRISPR genome editing and integrative genomic analyses reveal the mosaicism of Cas-induced mutations and pleiotropic effects of scarlet gene in an emerging model system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.29.577787. [PMID: 38352317 PMCID: PMC10862705 DOI: 10.1101/2024.01.29.577787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Despite the revolutionary impacts of CRISPR-Cas gene editing systems, the effective and widespread use of CRISPR technologies in emerging model organisms still faces significant challenges. These include the inefficiency in generating heritable mutations at the organismal level, limited knowledge about the genomic consequences of gene editing, and an inadequate understanding of the inheritance patterns of CRISPR-Cas-induced mutations. This study addresses these issues by 1) developing an efficient microinjection delivery method for CRISPR editing in the microcrustacean Daphnia pulex; 2) assessing the editing efficiency of Cas9 and Cas12a nucleases, examining mutation inheritance patterns, and analyzing the local and global mutation spectrum in the scarlet mutants; and 3) investigating the transcriptomes of scarlet mutants to understand the pleiotropic effects of scarlet underlying their swimming behavior changes. Our reengineered CRISPR microinjection method results in efficient biallelic editing with both nucleases. While indels are dominant in Cas-induced mutations, a few on-site large deletions (>1kb) are observed, most likely caused by microhomology-mediated end joining repair. Knock-in of a stop codon cassette to the scarlet locus was successful, despite complex induced mutations surrounding the target site. Moreover, extensive germline mosaicism exists in some mutants, which unexpectedly produce different phenotypes/genotypes in their asexual progenies. Lastly, our transcriptomic analyses unveil significant gene expression changes associated with scarlet knock-out and altered swimming behavior in mutants, including several genes (e.g., NMDA1, ABAT, CNTNAP2) involved in human neurodegenerative diseases. This study expands our understanding of the dynamics of gene editing in the tractable model organism Daphnia and highlights its promising potential as a neurological disease model.
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Affiliation(s)
- Sen Xu
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, 65211, USA
| | - Swatantra Neupane
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, 65211, USA
| | - Hongjun Wang
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019, USA
| | - Thinh Phu Pham
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019, USA
| | - Marelize Snyman
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019, USA
| | - Trung V. Huynh
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, 65211, USA
| | - Li Wang
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, 65211, USA
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Ortigoza-Escobar JD. Catching the Culprit: How Chorea May Signal an Inborn Error of Metabolism. Tremor Other Hyperkinet Mov (N Y) 2023; 13:36. [PMID: 37810989 PMCID: PMC10558026 DOI: 10.5334/tohm.801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 09/27/2023] [Indexed: 10/10/2023] Open
Abstract
Background Movement disorders, particularly chorea, are uncommon in inborn errors of metabolism, but their identification is essential for improved clinical outcomes. In this context, comprehensive descriptions of movement disorders are limited and primarily derived from single cases or small patient series, highlighting the need for increased awareness and additional research in this field. Methods A systematic review was conducted using the MEDLINE database and GeneReviews. The search included studies on inborn errors of metabolism associated with chorea, athetosis, or ballismus. The review adhered to PRISMA guidelines. Results The systematic review analyzed 76 studies out of 2350 records, encompassing the period from 1964 to 2022. Chorea was observed in 90.1% of the 173 patients, followed by athetosis in 5.7%. Various inborn errors of metabolism showed an association with chorea, with trace elements and metals being the most frequent. Cognitive and developmental abnormalities were common in the cohort. Frequent neurological features included seizures, dysarthria, and optic atrophy, whereas non-neurological features included, among others, facial dysmorphia and failure to thrive. Neuroimaging and biochemical testing played crucial roles in aiding diagnosis, revealing abnormal findings in 34.1% and 47.9% of patients, respectively. However, symptomatic treatment efficacy for movement disorders was limited. Discussion This study emphasizes the complexities of chorea in inborn errors of metabolism. A systematic approach with red flags, biochemical testing, and neuroimaging is required for diagnosis. Collaboration between neurologists, geneticists, and metabolic specialists is crucial for improving early detection and individualized treatment. Utilizing genetic testing technologies and potential therapeutic avenues can aid in the improvement of patient outcomes.
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Affiliation(s)
- Juan Darío Ortigoza-Escobar
- Department of Paediatric Neurology, Hospital Sant Joan de Déu, Barcelona, Spain
- European Reference Network for Rare Neurological Diseases (ERN-RND), Barcelona, Spain
- U-703 Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, Barcelona, Spain
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Zhang YM, Qi YB, Gao YN, Chen WG, Zhou T, Zang Y, Li J. Astrocyte metabolism and signaling pathways in the CNS. Front Neurosci 2023; 17:1217451. [PMID: 37732313 PMCID: PMC10507181 DOI: 10.3389/fnins.2023.1217451] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/18/2023] [Indexed: 09/22/2023] Open
Abstract
Astrocytes comprise half of the cells in the central nervous system and play a critical role in maintaining metabolic homeostasis. Metabolic dysfunction in astrocytes has been indicated as the primary cause of neurological diseases, such as depression, Alzheimer's disease, and epilepsy. Although the metabolic functionalities of astrocytes are well known, their relationship to neurological disorders is poorly understood. The ways in which astrocytes regulate the metabolism of glucose, amino acids, and lipids have all been implicated in neurological diseases. Metabolism in astrocytes has also exhibited a significant influence on neuron functionality and the brain's neuro-network. In this review, we focused on metabolic processes present in astrocytes, most notably the glucose metabolic pathway, the fatty acid metabolic pathway, and the amino-acid metabolic pathway. For glucose metabolism, we focused on the glycolysis pathway, pentose-phosphate pathway, and oxidative phosphorylation pathway. In fatty acid metabolism, we followed fatty acid oxidation, ketone body metabolism, and sphingolipid metabolism. For amino acid metabolism, we summarized neurotransmitter metabolism and the serine and kynurenine metabolic pathways. This review will provide an overview of functional changes in astrocyte metabolism and provide an overall perspective of current treatment and therapy for neurological disorders.
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Affiliation(s)
- Yong-mei Zhang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang, China
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ying-bei Qi
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang, China
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ya-nan Gao
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- Institute of Pharmaceutical Sciences, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Wen-gang Chen
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- Institute of Pharmaceutical Sciences, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Ting Zhou
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yi Zang
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jia Li
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang, China
- National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- Institute of Pharmaceutical Sciences, China Pharmaceutical University, Nanjing, Jiangsu, China
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Fukuyama K, Motomura E, Okada M. A Novel Gliotransmitter, L-β-Aminoisobutyric Acid, Contributes to Pathophysiology of Clinical Efficacies and Adverse Reactions of Clozapine. Biomolecules 2023; 13:1288. [PMID: 37759688 PMCID: PMC10526296 DOI: 10.3390/biom13091288] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
Clozapine is listed as one of the most effective antipsychotics and has been approved for treating treatment-resistant schizophrenia (TRS); however, several type A and B adverse reactions, including weight gain, metabolic complications, cardiotoxicity, convulsions, and discontinuation syndromes, exist. The critical mechanisms of clinical efficacy for schizophrenia, TRS, and adverse reactions of clozapine have not been elucidated. Recently, the GABA isomer L-β-aminoisobutyric acid (L-BAIBA), a protective myokine in the peripheral organs, was identified as a candidate novel transmission modulator in the central nervous system (CNS). L-BAIBA activates adenosine monophosphate-activated protein kinase (AMPK) signalling in both the peripheral organs and CNS. Activated AMPK signalling in peripheral organs is an established major target for treating insulin-resistant diabetes, whereas activated AMPK signalling in the hypothalamus contributes to the pathophysiology of weight gain and metabolic disturbances. Clozapine increases L-BAIBA synthesis in the hypothalamus. In addition, the various functions of L-BAIBA in the CNS have recently been elucidated, including as an activator of GABA-B and group-III metabotropic glutamate (III-mGlu) receptors. Considering the expressions of GABA-B and III-mGlu receptors (localised in the presynaptic regions), the activation of GABA-B and III-mGlu receptors can explain the distinct therapeutic advantages of clozapine in schizophrenia or TRS associated with N-methyl-D-aspartate (NMDA) receptor disturbance compared with other atypical antipsychotics via the inhibition of the persistent tonic hyperactivation of thalamocortical glutamatergic transmission in the prefrontal cortex. L-BAIBA has also been identified as a gliotransmitter, and a detailed exploration of the function of L-BAIBA in tripartite synaptic transmission can further elucidate the pathophysiology of effectiveness for treating TRS and/or specific adverse reactions of clozapine.
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Affiliation(s)
| | | | - Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (E.M.)
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Steel D, Reid KM, Pisani A, Hess EJ, Fox S, Kurian MA. Advances in targeting neurotransmitter systems in dystonia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:217-258. [PMID: 37482394 DOI: 10.1016/bs.irn.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Dystonia is characterised as uncontrolled, often painful involuntary muscle contractions that cause abnormal postures and repetitive or twisting movements. These movements can be continuous or sporadic and affect different parts of the body and range in severity. Dystonia and its related conditions present a huge cause of neurological morbidity worldwide. Although therapies are available, achieving optimal symptom control without major unwanted effects remains a challenge. Most pharmacological treatments for dystonia aim to modulate the effects of one or more neurotransmitters in the central nervous system, but doing so effectively and with precision is far from straightforward. In this chapter we discuss the physiology of key neurotransmitters, including dopamine, noradrenaline, serotonin (5-hydroxytryptamine), acetylcholine, GABA, glutamate, adenosine and cannabinoids, and their role in dystonia. We explore the ways in which existing pharmaceuticals as well as novel agents, currently in clinical trial or preclinical development, target dystonia, and their respective advantages and disadvantages. Finally, we discuss current and emerging genetic therapies which may be used to treat genetic forms of dystonia.
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Affiliation(s)
- Dora Steel
- UCL GOS Institute of Child Health (Zayed Centre for Research into Rare Diseases in Children), London, United Kingdom; Great Ormond Street Hospital for Children, London, United Kingdom
| | - Kimberley M Reid
- UCL GOS Institute of Child Health (Zayed Centre for Research into Rare Diseases in Children), London, United Kingdom
| | - Antonio Pisani
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; IRCCS Mondino Foundation, Pavia, Italy
| | - Ellen J Hess
- Emory University School of Medicine, CA, United States
| | - Susan Fox
- Movement Disorders Clinic, Toronto Western Hospital, University of Toronto, ON, Canada
| | - Manju A Kurian
- UCL GOS Institute of Child Health (Zayed Centre for Research into Rare Diseases in Children), London, United Kingdom; Great Ormond Street Hospital for Children, London, United Kingdom.
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8
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Yasir M, Park J, Han ET, Park WS, Han JH, Kwon YS, Lee HJ, Chun W. Computational Exploration of the Effects of Mutations on GABA Aminotransferase in GABA Aminotransferase Deficiency. Int J Mol Sci 2023; 24:10933. [PMID: 37446113 DOI: 10.3390/ijms241310933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) transaminase-also called GABA aminotransferase (GABA-AT)-deficiency is a rare autosomal recessive disorder characterized by a severe neonatal-infantile epileptic encephalopathy with symptoms such as seizures, hypotonia, hyperreflexia, developmental delay, and growth acceleration. GABA transaminase deficiency is caused by mutations in GABA-AT, the enzyme responsible for the catabolism of GABA. Mutations in multiple locations on GABA-AT have been reported and their locations have been shown to influence the onset of the disease and the severity of symptoms. We examined how GABA-AT mutations influence the structural stability of the enzyme and GABA-binding affinity using computational methodologies such as molecular dynamics simulation and binding free energy calculation to understand the underlying mechanism through which GABA-AT mutations cause GABA-AT deficiency. GABA-AT 3D model depiction was carried out together with seven individual mutated models of GABA-AT. The structural stability of all the predicted models was analyzed using several tools and web servers. All models were evaluated based on their phytochemical values. Additionally, 100 ns MD simulation was carried out and the mutated models were evaluated using RMSD, RMSF, Rg, and SASA. gmxMMPBSA free energy calculation was carried out. Moreover, RMSD and free energy calculations were also compared with those obtained using online web servers. Our study demonstrates that P152S, Q296H, and R92Q play a more critical role in the structural instability of GABA-AT compared with the other mutated models: G465R, L211F, L478P, and R220K.
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Affiliation(s)
- Muhammad Yasir
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Jinyoung Park
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Yong-Soo Kwon
- College of Pharmacy, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Hee-Jae Lee
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
| | - Wanjoo Chun
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea
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9
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Andersen JV, Schousboe A. Glial Glutamine Homeostasis in Health and Disease. Neurochem Res 2023; 48:1100-1128. [PMID: 36322369 DOI: 10.1007/s11064-022-03771-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 08/25/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022]
Abstract
Glutamine is an essential cerebral metabolite. Several critical brain processes are directly linked to glutamine, including ammonia homeostasis, energy metabolism and neurotransmitter recycling. Astrocytes synthesize and release large quantities of glutamine, which is taken up by neurons to replenish the glutamate and GABA neurotransmitter pools. Astrocyte glutamine hereby sustains the glutamate/GABA-glutamine cycle, synaptic transmission and general brain function. Cerebral glutamine homeostasis is linked to the metabolic coupling of neurons and astrocytes, and relies on multiple cellular processes, including TCA cycle function, synaptic transmission and neurotransmitter uptake. Dysregulations of processes related to glutamine homeostasis are associated with several neurological diseases and may mediate excitotoxicity and neurodegeneration. In particular, diminished astrocyte glutamine synthesis is a common neuropathological component, depriving neurons of an essential metabolic substrate and precursor for neurotransmitter synthesis, hereby leading to synaptic dysfunction. While astrocyte glutamine synthesis is quantitatively dominant in the brain, oligodendrocyte-derived glutamine may serve important functions in white matter structures. In this review, the crucial roles of glial glutamine homeostasis in the healthy and diseased brain are discussed. First, we provide an overview of cellular recycling, transport, synthesis and metabolism of glutamine in the brain. These cellular aspects are subsequently discussed in relation to pathological glutamine homeostasis of hepatic encephalopathy, epilepsy, Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis. Further studies on the multifaceted roles of cerebral glutamine will not only increase our understanding of the metabolic collaboration between brain cells, but may also aid to reveal much needed therapeutic targets of several neurological pathologies.
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Affiliation(s)
- Jens V Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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10
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Astrocytes regulate inhibitory neurotransmission through GABA uptake, metabolism, and recycling. Essays Biochem 2023; 67:77-91. [PMID: 36806927 DOI: 10.1042/ebc20220208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 02/23/2023]
Abstract
Synaptic regulation of the primary inhibitory neurotransmitter γ-aminobutyric acid (GABA) is essential for brain function. Cerebral GABA homeostasis is tightly regulated through multiple mechanisms and is directly coupled to the metabolic collaboration between neurons and astrocytes. In this essay, we outline and discuss the fundamental roles of astrocytes in regulating synaptic GABA signaling. A major fraction of synaptic GABA is removed from the synapse by astrocytic uptake. Astrocytes utilize GABA as a metabolic substrate to support glutamine synthesis. The astrocyte-derived glutamine is subsequently transferred to neurons where it serves as the primary precursor of neuronal GABA synthesis. The flow of GABA and glutamine between neurons and astrocytes is collectively termed the GABA-glutamine cycle and is essential to sustain GABA synthesis and inhibitory signaling. In certain brain areas, astrocytes are even capable of synthesizing and releasing GABA to modulate inhibitory transmission. The majority of oxidative GABA metabolism in the brain takes place in astrocytes, which also leads to synthesis of the GABA-related metabolite γ-hydroxybutyric acid (GHB). The physiological roles of endogenous GHB remain unclear, but may be related to regulation of tonic inhibition and synaptic plasticity. Disrupted inhibitory signaling and dysfunctional astrocyte GABA handling are implicated in several diseases including epilepsy and Alzheimer's disease. Synaptic GABA homeostasis is under astrocytic control and astrocyte GABA uptake, metabolism, and recycling may therefore serve as relevant targets to ameliorate pathological inhibitory signaling.
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11
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Kentab AY. Gamma-Aminobutyric Acid Transaminase (GABA-T) Deficiency in a Consanguineous Saudi Family: A Case Report and Literature Review. JOURNAL OF PEDIATRIC EPILEPSY 2022. [DOI: 10.1055/s-0042-1757447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractGamma-aminobutyric acid transaminase (GABA-T) deficiency is a rare, autosomal recessive disorder caused by mutations in the 4-aminobutyrate aminotransferase (ABAT) gene, which encodes an enzyme involved in GABA catabolism. It is characterized by severe psychomotor retardation, early-onset epileptic encephalopathy, intractable seizures, hypotonia, hyperreflexia, movement disorder, hypersomnolence, and early childhood mortality. It is associated with elevated free GABA in cerebrospinal fluid (CSF), GABA-T deficiency in cultured lymphoblasts, hypomyelination on brain magnetic resonance imaging (MRI), and elevated GABA level in the basal ganglia on proton magnetic resonance spectroscopy (MRS). Only 14 cases have been published in the literature. A rare case of infantile epileptic encephalopathy caused by GABA-T deficiency resulting from a previously unreported homozygous missense mutation in the ABAT gene is described. Our findings add to the phenotypic, neuroradiological, and genetic spectrum of ABAT mutations.
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Affiliation(s)
- Amal Y. Kentab
- Department of Paediatrics, Neurology Division, College of Medicine, King Saud University, King Saud University Medical City, Riyadh, Saudi Arabia
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12
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Andersen JV, Schousboe A, Verkhratsky A. Astrocyte energy and neurotransmitter metabolism in Alzheimer's disease: integration of the glutamate/GABA-glutamine cycle. Prog Neurobiol 2022; 217:102331. [PMID: 35872221 DOI: 10.1016/j.pneurobio.2022.102331] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 02/06/2023]
Abstract
Astrocytes contribute to the complex cellular pathology of Alzheimer's disease (AD). Neurons and astrocytes function in close collaboration through neurotransmitter recycling, collectively known as the glutamate/GABA-glutamine cycle, which is essential to sustain neurotransmission. Neurotransmitter recycling is intimately linked to astrocyte energy metabolism. In the course of AD, astrocytes undergo extensive metabolic remodeling, which may profoundly affect the glutamate/GABA-glutamine cycle. The consequences of altered astrocyte function and metabolism in relation to neurotransmitter recycling are yet to be comprehended. Metabolic alterations of astrocytes in AD deprive neurons of metabolic support, thereby contributing to synaptic dysfunction and neurodegeneration. In addition, several astrocyte-specific components of the glutamate/GABA-glutamine cycle, including glutamine synthesis and synaptic neurotransmitter uptake, are perturbed in AD. Integration of the complex astrocyte biology within the context of AD is essential for understanding the fundamental mechanisms of the disease, while restoring astrocyte metabolism may serve as an approach to arrest or even revert clinical progression of AD.
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Affiliation(s)
- Jens V Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102 Vilnius, Lithuania.
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13
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Feng Y, Wei ZH, Liu C, Li GY, Qiao XZ, Gan YJ, Zhang CC, Deng YC. Genetic variations in GABA metabolism and epilepsy. Seizure 2022; 101:22-29. [PMID: 35850019 DOI: 10.1016/j.seizure.2022.07.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 11/18/2022] Open
Abstract
Epilepsy is a paroxysmal brain disorder that results from an imbalance between neuronal excitation and inhibition. Gamma-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the brain and plays an important role in the occurrence and development of epilepsy. Abnormalities in all aspects of GABA metabolism, including GABA synthesis, transport, genes encoding GABA receptors, and GABA inactivation, may lead to epilepsy. GABRA1, GABRA2, GABRA5, GABRB1, GABRB2, GABRB3, GABRG2 and GABBR2 are genes that encode GABA receptors and are commonly associated with epilepsy. Mutations of these genes lead to a variety of epilepsy syndromes with different clinical phenotypes, primarily by down regulating receptor expression and reducing the amplitude of GABA-evoked potentials. GABA is metabolized by GABA transaminase and succinate semi aldehyde dehydrogenase, which are encoded by the ABAT and ALDH5A1 genes, respectively. Mutations of these genes result in symptoms related to deficiency of GABA transaminase and succinate semi aldehyde dehydrogenase, such as epilepsy and cognitive impairment. Most of the variation in genes associated with GABA metabolism are accompanied by developmental disorders. This review focuses on advances in understanding the relationship between genetic variation in GABA metabolism and epilepsy to establish a basis for the accurate diagnosis and treatment of epilepsy.
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Affiliation(s)
- Yan Feng
- Xi'an Medical University, Xi'an 710021, People's Republic of China; Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Zi-Han Wei
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Chao Liu
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Guo-Yan Li
- Xi'an Medical University, Xi'an 710021, People's Republic of China; Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Xiao-Zhi Qiao
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Ya-Jing Gan
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Chu-Chu Zhang
- Xi'an Medical University, Xi'an 710021, People's Republic of China
| | - Yan-Chun Deng
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
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14
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2022 Overview of Metabolic Epilepsies. Genes (Basel) 2022; 13:genes13030508. [PMID: 35328062 PMCID: PMC8952328 DOI: 10.3390/genes13030508] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/04/2022] Open
Abstract
Understanding the genetic architecture of metabolic epilepsies is of paramount importance, both to current clinical practice and for the identification of further research directions. The main goals of our study were to identify the scope of metabolic epilepsies and to investigate their clinical presentation, diagnostic approaches and treatments. The International Classification of Inherited Metabolic Disorders and IEMbase were used as a basis for the identification and classification of metabolic epilepsies. Six hundred metabolic epilepsies have been identified, accounting for as much as 37% of all currently described inherited metabolic diseases (IMD). Epilepsy is a particularly common symptom in disorders of energy metabolism, congenital disorders of glycosylation, neurotransmitter disorders, disorders of the synaptic vesicle cycle and some other IMDs. Seizures in metabolic epilepsies may present variably, and most of these disorders are complex and multisystem. Abnormalities in routine laboratory tests and/or metabolic testing may be identified in 70% of all metabolic epilepsies, but in many cases they are non-specific. In total, 111 metabolic epilepsies (18% of all) have specific treatments that may significantly change health outcomes if diagnosed in time. Although metabolic epilepsies comprise an important and significant group of disorders, their real scope and frequency may have been underestimated.
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15
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Zhang M, Zhong H, Cao T, Huang Y, Ji X, Fan GC, Peng T. Gamma-Aminobutyrate Transaminase Protects against Lipid Overload-Triggered Cardiac Injury in Mice. Int J Mol Sci 2022; 23:ijms23042182. [PMID: 35216295 PMCID: PMC8874535 DOI: 10.3390/ijms23042182] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/10/2022] [Accepted: 02/13/2022] [Indexed: 12/26/2022] Open
Abstract
Lipid overload contributes to cardiac complications of diabetes and obesity. However, the underlying mechanisms remain obscure. This study investigates the role of gamma-aminobutyrate transaminase (ABAT), the key enzyme involved in the catabolism of γ-aminobutyric acid (GABA), in lipid overload-induced cardiac injury. Microarray revealed a down-regulation of ABAT mRNA expression in high fat diet (HFD)-fed mouse hearts, which correlated with a reduction in ABAT protein level and its GABA catabolic activity. Transgenic mice with cardiomyocyte-specific ABAT over-expression (Tg-ABAT/tTA) were generated to determine the role of ABAT in lipid overload-induced cardiac injury. Feeding with a HFD to control mice for 4 months reduced ATP production and the mitochondrial DNA copy number, and induced myocardial oxidative stress, hypertrophy, fibrosis and dysfunction. Such pathological effects of HFD were mitigated by ABAT over-expression in Tg-ABAT/tTA mice. In cultured cardiomyocytes, palmitate increased mitochondrial ROS production, depleted ATP production and promoted apoptosis, all of which were attenuated by ABAT over-expression. With the inhibition of ABAT’s GABA catabolic activity, the protective effects of ABAT remained unchanged in palmitate-induced cardiomyocytes. Thus, ABAT protects the mitochondrial function in defending the heart against lipid overload-induced injury through mechanisms independent of its GABA catabolic activity, and may represent a new therapeutic target for lipid overload-induced cardiac injury.
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Affiliation(s)
- Mengxiao Zhang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (M.Z.); (H.Z.); (T.C.); (Y.H.)
- School of Pharmacy, Bengbu Medical College, Bengbu 233000, China
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 5C1, Canada;
| | - Huiting Zhong
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (M.Z.); (H.Z.); (T.C.); (Y.H.)
| | - Ting Cao
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (M.Z.); (H.Z.); (T.C.); (Y.H.)
| | - Yifan Huang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (M.Z.); (H.Z.); (T.C.); (Y.H.)
| | - Xiaoyun Ji
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 5C1, Canada;
- Lawson Health Research Institute, London Health Sciences Centre, London, ON N6A 5W9, Canada
| | - Guo-Chang Fan
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
| | - Tianqing Peng
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 5C1, Canada;
- Lawson Health Research Institute, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Medicine, Western University, London, ON N6A 5W9, Canada
- VRLA6-140, 800 Commissioners Road, London, ON N6A 5W9, Canada
- Correspondence: ; Tel.: +1-519-6858500-55441
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16
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Ikeda A, Tomiyasu M, Yamamoto A, Tsuyusaki Y, Kawai Y, Tanabe M, Tsuji M, Iai M, Aida N, Goto T. Elevation of brain gamma‐aminobutyric acid levels is associated with vigabatrin‐associated brain abnormalities on magnetic resonance imaging. Epilepsy Res 2022; 181:106881. [DOI: 10.1016/j.eplepsyres.2022.106881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/14/2022] [Accepted: 02/04/2022] [Indexed: 11/29/2022]
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17
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Coupling of GABA Metabolism to Mitochondrial Glucose Phosphorylation. Neurochem Res 2021; 47:470-480. [PMID: 34623563 DOI: 10.1007/s11064-021-03463-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/15/2021] [Accepted: 10/04/2021] [Indexed: 10/20/2022]
Abstract
Glucose and oxygen (O2) are vital to the brain. Glucose metabolism and mitochondria play a pivotal role in this process, culminating in the increase of reactive O2 species. Hexokinase (HK) is a key enzyme on glucose metabolism and is coupled to the brain mitochondrial redox modulation by recycling ADP for oxidative phosphorylation (OXPHOS). GABA shunt is an alternative pathway to GABA metabolism that increases succinate levels, a Krebs cycle intermediate. Although glucose and GABA metabolisms are intrinsically connected, their interplay coordinating mitochondrial function is poorly understood. Here, we hypothesize that the HK and the GABA shunt interact to control mitochondrial metabolism differently in the cortex and the hypothalamus. The GABA shunt stimulated mitochondrial O2 consumption and H2O2 production higher in hypothalamic synaptosomes (HSy) than cortical synaptosomes (CSy). The GABA shunt increased the HK coupled to OXPHOS activity in both population of synaptosomes, but the rate of activation was higher in HSy than CSy. Significantly, malonate and vigabatrin blocked the effects of the GABA shunt in the HK activity coupled to OXPHOS. It indicates that the glucose phosphorylation is linked to GABA and Krebs cycle reactions. Together, these data shed light on the HK and SDH role on the metabolism of each region fed by GABA turnover, which depends on the neurons' metabolic route.
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18
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Aida N. 1H-MR Spectroscopy of the Early Developmental Brain, Neonatal Encephalopathies, and Neurometabolic Disorders. Magn Reson Med Sci 2021; 21:9-28. [PMID: 34421092 PMCID: PMC9199977 DOI: 10.2463/mrms.rev.2021-0055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
MRI interpretations of the pediatric brain are often challenging for general radiologists and clinicians because MR signals and morphology are continuously changing in the developing brain. Furthermore, the developing brain reacts differently to injuries, resulting in imaging characteristics that differ from those of the mature brain. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive method for assessing neurological abnormalities at the microscopic level and measures in vivo brain metabolites using a clinical MR machine. In MR examinations of the pediatric brain, 1H-MRS demonstrates its powerful diagnostic capability when MRI is insufficient for diagnostic features. MRI and 1H-MRS may be complementary tools for diagnosing and monitoring diseases. However, there is currently no consensus on how to include 1H-MRS in clinical MR examinations. An overview of the clinical implementation of 1H-MRS for the assessment of early pediatric developmental brains as well as the diagnosis, prognostification, and disease monitoring of various non-neoplastic brain disorders, including neonatal encephalopathies and neurometabolic/neurodegenerative diseases, was provided herein. Qualitative and quantitative 1H-MRS is a powerful non-invasive tool for accessing various brain metabolites to confirm age appropriate peaks and detect abnormal peaks or deficient or reduced peaks, which may facilitate the identification of metabolic and neurodegenerative disorders as well as damage associated with hypoxic-ischemic encephalopathy (HIE). Moreover, 1H-MRS has potential as a biomarker for monitoring therapeutic efficacy in metabolic diseases and neonatal HIE. It also provides insights into the pathophysiologies of various disorders, which may facilitate the use of novel therapeutic approaches. Therefore, 1H-MRS needs to be included more frequently in routine clinical MR examinations of pediatric patients with neurological disorders.
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Affiliation(s)
- Noriko Aida
- Department of Radiology, Kanagawa Children's Medical Center.,Department of Diagnostic Radiology, Yokohama City University Graduate School of Medicine
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19
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Liao JY, Salles PA, Shuaib UA, Fernandez HH. Genetic updates on paroxysmal dyskinesias. J Neural Transm (Vienna) 2021; 128:447-471. [PMID: 33929620 DOI: 10.1007/s00702-021-02335-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/31/2021] [Indexed: 12/17/2022]
Abstract
The paroxysmal dyskinesias are a diverse group of genetic disorders that manifest as episodic movements, with specific triggers, attack frequency, and duration. With recent advances in genetic sequencing, the number of genetic variants associated with paroxysmal dyskinesia has dramatically increased, and it is now evident that there is significant genotype-phenotype overlap, reduced (or incomplete) penetrance, and phenotypic variability. In addition, a variety of genetic conditions can present with paroxysmal dyskinesia as the initial symptom. This review will cover the 34 genes implicated to date and propose a diagnostic workflow featuring judicious use of whole-exome or -genome sequencing. The goal of this review is to provide a common understanding of paroxysmal dyskinesias so basic scientists, geneticists, and clinicians can collaborate effectively to provide diagnoses and treatments for patients.
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Affiliation(s)
- James Y Liao
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Philippe A Salles
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
- Centro de Trastornos del Movimiento, CETRAM, Santiago, Chile
| | - Umar A Shuaib
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Hubert H Fernandez
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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20
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Oshi A, Alfaifi A, Seidahmed MZ, Al Hussein K, Miqdad A, Samadi A, Abdelbasit O. GABA transaminase deficiency. Case report and literature review. Clin Case Rep 2021; 9:1295-1298. [PMID: 33768830 PMCID: PMC7981681 DOI: 10.1002/ccr3.3753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/09/2020] [Accepted: 09/17/2020] [Indexed: 11/07/2022] Open
Abstract
GABA transaminase deficiency should be considered in the differential diagnosis of early onset epileptic encephalopathies. This case was diagnosed post-mortem, but increased vigilance to this will allow for earlier diagnoses in other infants and families. This is a case study which involved diagnosis of a rare neurometabolic disorder in one of the babies in the family and eventual genetic counselling of the family. The family has been offered pre-implantation genetic diagnosis for future pregnancies. This case reporting has been approved by the hospital research and ethical committee.
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Affiliation(s)
- Amira Oshi
- Department of PediatricsSecurity Forces HospitalRiyadhSaudi Arabia
| | - Abdullah Alfaifi
- Department of PediatricsSecurity Forces HospitalRiyadhSaudi Arabia
| | | | | | - Abeer Miqdad
- Department of PediatricsSecurity Forces HospitalRiyadhSaudi Arabia
| | | | - Omar Abdelbasit
- Department of PediatricsSecurity Forces HospitalRiyadhSaudi Arabia
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21
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Zheng Q, Bi R, Xu M, Zhang DF, Tan LW, Lu YP, Yao YG. Exploring the Genetic Association of the ABAT Gene with Alzheimer's Disease. Mol Neurobiol 2021; 58:1894-1903. [PMID: 33404980 DOI: 10.1007/s12035-020-02271-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022]
Abstract
Accumulating evidence demonstrated that GABAergic dysfunction contributes to the pathogenesis of Alzheimer's disease (AD). The GABA aminotransferase (ABAT) gene encodes a mitochondrial GABA transaminase and plays key roles in the biogenesis and metabolism of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. In this study, we performed an integrative study at the genetic and expression levels to investigate the potential genetic association between the ABAT gene and AD. Through re-analyzing data from the currently largest meta-analysis of AD genome-wide association study (GWAS), we identified genetic variants in the 3'-UTR of ABAT as the top AD-associated SNPs (P < 1 × 10-4) in this gene. Functional annotation of these AD-associated SNPs indicated that these SNPs are located in the regulatory regions of transcription factors or/and microRNAs. Expression quantitative trait loci (eQTL) analysis and luciferase reporter assay showed that the AD risk alleles of these SNPs were associated with a reduced expression level of ABAT. Further analysis of mRNA expression data and single-cell transcriptome data of AD patients showed that ABAT reduction in the neuron is an early event during AD development. Overall, our results indicated that ABAT genetic variants may be associated with AD through affecting its mRNA expression. An abnormal level of ABAT will lead to a disturbance of the GABAergic signal pathway in AD brains.
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Affiliation(s)
- Quanzhen Zheng
- College of Life Sciences, Anhui Normal University, Wuhu, 241002, Anhui, China.,Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
| | - Rui Bi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China.,Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Min Xu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
| | - Deng-Feng Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China
| | - Li-Wen Tan
- Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, 410011, China
| | - Ya-Ping Lu
- College of Life Sciences, Anhui Normal University, Wuhu, 241002, Anhui, China
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China. .,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China. .,Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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22
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Mastrangelo M. Epilepsy in inherited neurotransmitter disorders: Spotlights on pathophysiology and clinical management. Metab Brain Dis 2021; 36:29-43. [PMID: 33095372 DOI: 10.1007/s11011-020-00635-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/16/2020] [Indexed: 01/02/2023]
Abstract
Inborn errors of neurotransmitter metabolism are ultrarare disorders affecting neurotransmitter biosynthesis, breakdown or transport or their essential cofactors. Neurotransmitter dysfunctions could also result from the impairment of neuronal receptors, intracellular signaling, vesicle release or other synaptic abnormalities. Epilepsy is the main clinical hallmark in some of these diseases (e.g. disorders of GABA metabolism, glycine encephalopathy) while it is infrequent in others (e.g. all the disorders of monoamine metabolism in exception for dihydropteridine reductase deficiency). This review analyzes the epileptogenic mechanisms, the epilepsy phenotypes and the principle for the clinical management of epilepsy in primary and secondary inherited disorders of neurotransmitter metabolism (disorders of GABA, serine and glycine metabolism, disorders of neurotransmitter receptors and secondary neurotransmitter diseases).
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Affiliation(s)
- Mario Mastrangelo
- Child Neurology and Psychiatry Unit-Department of Human Neuroscience, Sapienza Università di Roma-Umberto I Policlinico di Roma, Via dei Sabelli, 108 - 00141, Roma, Italy.
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23
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CRISPR/Cas9-engineered Gad1 elimination in rats leads to complex behavioral changes: implications for schizophrenia. Transl Psychiatry 2020; 10:426. [PMID: 33293518 PMCID: PMC7723991 DOI: 10.1038/s41398-020-01108-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/06/2020] [Accepted: 11/16/2020] [Indexed: 12/19/2022] Open
Abstract
GABAergic dysfunctions have been implicated in the pathogenesis of schizophrenia, especially the associated cognitive impairments. The GABA synthetic enzyme glutamate decarboxylase 67-kDa isoform (GAD67) encoded by the GAD1 gene is downregulated in the brains of patients with schizophrenia. Furthermore, a patient with schizophrenia harboring a homozygous mutation of GAD1 has recently been discovered. However, it remains unclear whether loss of function of GAD1 leads to the symptoms observed in schizophrenia, including cognitive impairment. One of the obstacles faced in experimental studies to address this issue is the perinatal lethality of Gad1 knockout (KO) mice, which precluded characterization at the adult stage. In the present study, we successfully generated Gad1 KO rats using CRISPR/Cas9 genome editing technology. Surprisingly, 33% of Gad1 KO rats survived to adulthood and could be subjected to further characterization. The GABA concentration in the Gad1 KO cerebrum was reduced to ~52% of the level in wild-type rats. Gad1 KO rats exhibited impairments in both spatial reference and working memory without affecting adult neurogenesis in the hippocampus. In addition, Gad1 KO rats showed a wide range of behavioral alterations, such as enhanced sensitivity to an NMDA receptor antagonist, hypoactivity in a novel environment, and decreased preference for social novelty. Taken together, the results suggest that Gad1 KO rats could provide a novel model covering not only cognitive deficits but also other aspects of the disorder. Furthermore, the present study teaches an important lesson: differences between species should be considered when developing animal models of human diseases.
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24
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The characterization of psychotic symptoms in succinic semialdehyde dehydrogenase deficiency: a review. Psychiatr Genet 2020; 30:153-161. [PMID: 33165204 DOI: 10.1097/ypg.0000000000000264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Succinic semialdehyde dehydrogenase (SSADH) deficiency is an ultra-rare inborn error of metabolism that results in disrupted gamma-amino butyric acid (GABA) catabolism. In addition to developmental delay, intellectual disability, hypotonia, ataxia, and seizures, a variety of neuropsychiatric symptoms may occur, including psychosis. By highlighting all available and relevant case reports/series, this qualitative review seeks to characterize the prevalence, clinical manifestation, pathophysiology, and treatment of psychotic symptoms in this population. Psychosis occurs in a minority of SSADH-deficient individuals, and most commonly presents as auditory or visual hallucinations with an onset in adolescence or young adulthood. Although the pathophysiology underlying the development of psychosis in this context is not fully understood, it likely in part relates to increased GABA and/or gamma hydroxybutyric acid activity. Although antipsychotic medications should be used cautiously in SSADH deficiency, they may be effective at treating emergent psychotic symptoms.
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25
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Abstract
Neonates presenting with seizures are frequently assessed and managed by neonatologists in the NICU. Although hypoxic-ischemic encephalopathy and infection are common underlying causes of neonatal seizures, many patients with neonatal epilepsy will have an identifiable genetic etiology. Often these cases will be evaluated in collaboration with a geneticist. The categories of genetic causes of neonatal seizures include 1) structural brain malformations; 2) inborn errors of metabolism; 3) syndromic; and 4) nonsyndromic, single gene. Evaluation of these patients involves a comprehensive history and examination, followed by appropriate investigations and diagnostic genetic testing. Components of the diagnostic process will vary based on the clinical suspicion and differential diagnoses. In certain cases, syndromic surveillance for evaluation of other congenital anomalies may be recommended. Determination of the underlying genetic diagnosis, when present, will have important implications for treatment. Targeted therapies are currently available for specific genetic syndromes, and outcomes may improve with earlier initiation of therapy. Certain genetic diagnoses may also have guideline-based management involving screening for other manifestations of the disorder.
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Affiliation(s)
- Shagun Kaur
- Division of Genetic, Genomic, and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI
| | - Kara Pappas
- Division of Genetic, Genomic, and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI.,Department of Pediatrics, Central Michigan University, Mt Pleasant, MI
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26
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Andersen JV, Jakobsen E, Westi EW, Lie MEK, Voss CM, Aldana BI, Schousboe A, Wellendorph P, Bak LK, Pinborg LH, Waagepetersen HS. Extensive astrocyte metabolism of γ-aminobutyric acid (GABA) sustains glutamine synthesis in the mammalian cerebral cortex. Glia 2020; 68:2601-2612. [PMID: 32584476 DOI: 10.1002/glia.23872] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/15/2022]
Abstract
Synaptic transmission is closely linked to brain energy and neurotransmitter metabolism. However, the extent of brain metabolism of the inhibitory neurotransmitter γ-aminobutyric acid (GABA), and the relative metabolic contributions of neurons and astrocytes, are yet unknown. The present study was designed to investigate the functional significance of brain GABA metabolism using isolated mouse cerebral cortical slices and slices of neurosurgically resected neocortical human tissue of the temporal lobe. By using dynamic isotope labeling, with [15 N]GABA and [U-13 C]GABA as metabolic substrates, we show that both mouse and human brain slices exhibit a large capacity for GABA metabolism. Both the nitrogen and the carbon backbone of GABA strongly support glutamine synthesis, particularly in the human cerebral cortex, indicative of active astrocytic GABA metabolism. This was further substantiated by pharmacological inhibition of the primary astrocytic GABA transporter subtype 3 (GAT3), by (S)-SNAP-5114 or 1-benzyl-5-chloro-2,3-dihydro-1H-indole-2,3-dione (compound 34), leading to significant reductions in oxidative GABA carbon metabolism. Interestingly, this was not the case when tiagabine was used to specifically inhibit GAT1, which is predominantly found on neurons. Finally, we show that acute GABA exposure does not directly stimulate glycolytic activity nor oxidative metabolism in cultured astrocytes, but can be used as an additional substrate to enhance uncoupled respiration. These results clearly show that GABA is actively metabolized in astrocytes, particularly for the synthesis of glutamine, and challenge the current view that synaptic GABA homeostasis is maintained primarily by presynaptic recycling.
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Affiliation(s)
- Jens V Andersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Jakobsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil W Westi
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria E K Lie
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline M Voss
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Blanca I Aldana
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars H Pinborg
- Epilepsy Clinic and Neurobiology Research Unit, Copenhagen University Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Brown M, Turgeon C, Rinaldo P, Pop A, Salomons GS, Roullet J, Gibson KM. Longitudinal metabolomics in dried bloodspots yields profiles informing newborn screening for succinic semialdehyde dehydrogenase deficiency. JIMD Rep 2020; 53:29-38. [PMID: 32395407 PMCID: PMC7203655 DOI: 10.1002/jmd2.12075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 12/23/2022] Open
Abstract
Analyses of 19 amino acids, 38 acylcarnitines, and 3 creatine analogues (https://clir.mayo.edu) were implemented to test the hypothesis that succinic semialdehyde dehydrogenase deficiency (SSADHD) could be identified in dried bloodspots (DBS) using currently available newborn screening methodology. The study population included 17 post-newborn SSADHD DBS (age range 0.8-38 years; median, 8.2 years; 10 M; controls, 129-353 age-matched individuals, mixed gender) and 10 newborn SSADHD DBS (including first and second screens from 3 of 7 patients). Low (informative) markers in post-newborn DBS included C2- and C4-OH carnitines, ornithine, histidine and creatine, with no gender differences. For newborn DBS, informative markers included C2-, C3-, C4- and C4-OH carnitines, creatine and ornithine. Of these, only creatine demonstrated a significant change with age, revealing an approximate 4-fold decrease. We conclude that quantitation of short-chain acylcarnitines, creatine, and ornithine provides a newborn DBS profile with potential as a first tier screening tool for early detection of SSADHD. This first tier evaluation can be readily verified using a previously described second tier liquid chromatography-tandem mass spectrometry method for γ-hydroxybutyric acid in the same DBS. More extensive evaluation of this first/second tier screening approach is needed in a larger population.
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Affiliation(s)
- Madalyn Brown
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
| | - Coleman Turgeon
- Mayo Clinic, Department of Laboratory Medicine and PathologyRochesterMinnesota
| | - Piero Rinaldo
- Mayo Clinic, Department of Laboratory Medicine and PathologyRochesterMinnesota
| | - Ana Pop
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical CentersVrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
| | - Gajja S. Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical CentersVrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
- Department of Genetic Metabolic Diseases, Amsterdam University Medical CentersUniversity of Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
| | - Jean‐Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
| | - K. Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
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Si W, Li H, Kang T, Ye J, Yao Z, Liu Y, Yu T, Zhang Y, Ling Y, Cao H, Wang J, Li Y, Fang F. Effect of GABA-T on Reproductive Function in Female Rats. Animals (Basel) 2020; 10:ani10040567. [PMID: 32230949 PMCID: PMC7222393 DOI: 10.3390/ani10040567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/16/2020] [Accepted: 03/25/2020] [Indexed: 12/29/2022] Open
Abstract
This study explored the role of γ-aminobutyric acid transaminase (GABA-T) in the puberty and reproductive performance of female rats. Immunofluorescence technique, quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution of GABA-T and the expression of genes and hormones in female rats, respectively. The results showed that GABA-T was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN) and periventricular nucleus (PeN) of the hypothalamus, and in the adenohypophysis, ovarian granulosa cells and oocytes. Abat mRNA level at 28 d was lowest in the hypothalamus and the pituitary; at puberty, it was lowest in the ovary. Abat mRNA level was highest in adults in the hypothalamus; at infancy and puberty, it was highest in the pituitary; and at 21 d it was highest in the ovary. After vigabatrin (GABA-T irreversible inhibitor) was added to hypothalamus cells, the levels of Abat mRNA and Rfrp-3 mRNA were significantly reduced, but Gnrh mRNA increased at the dose of 25 and 50 μg/mL; Kiss1 mRNA was significantly increased but Gabbr1 mRNA was reduced at the 50 μg/mL dose. In prepubertal rats injected with vigabatrin, puberty onset was delayed. Abat mRNA, Kiss1 mRNA and Gnrh mRNA levels were significantly reduced, but Rfrp-3 mRNA level increased in the hypothalamus. Vigabatrin reduced the concentrations of GABA-T, luteinizing hormone (LH) and progesterone (P4), and the ovarian index. Lactation performance was reduced in adult rats with vigabatrin treatment. Four hours after vigabatrin injection, the concentrations of GABA-T and LH were significantly reduced in adult and 25 d rats, but follicle-stimulating hormone (FSH) increased in 25 d rats. In conclusion, GABA-T affects the reproductive function of female rats by regulating the levels of Gnrh, Kiss1 and Rfrp-3 in the hypothalamus as well as the concentrations of LH and P4.
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Affiliation(s)
- Wenyu Si
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Hailing Li
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Tiezhu Kang
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Jing Ye
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Zhiqiu Yao
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Ya Liu
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Tong Yu
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Yunhai Zhang
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Yinghui Ling
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Hongguo Cao
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Juhua Wang
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Yunsheng Li
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
| | - Fugui Fang
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China; (W.S.); (H.L.); (T.K.); (J.Y.); (Z.Y.); (Y.L.); (T.Y.); (Y.Z.); (Y.L.); (H.C.); (J.W.); (Y.L.)
- Anhui Provincial Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei 230036, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China
- Correspondence:
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Rumping L, Vringer E, Houwen RHJ, van Hasselt PM, Jans JJM, Verhoeven‐Duif NM. Inborn errors of enzymes in glutamate metabolism. J Inherit Metab Dis 2020; 43:200-215. [PMID: 31603991 PMCID: PMC7078983 DOI: 10.1002/jimd.12180] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 10/01/2019] [Accepted: 10/04/2019] [Indexed: 12/29/2022]
Abstract
Glutamate is involved in a variety of metabolic pathways. We reviewed the literature on genetic defects of enzymes that directly metabolise glutamate, leading to inborn errors of glutamate metabolism. Seventeen genetic defects of glutamate metabolising enzymes have been reported, of which three were only recently identified. These 17 defects affect the inter-conversion of glutamine and glutamate, amino acid metabolism, ammonia detoxification, and glutathione metabolism. We provide an overview of the clinical and biochemical phenotypes of these rare defects in an effort to ease their recognition. By categorising these by biochemical pathway, we aim to create insight into the contributing role of deviant glutamate and glutamine levels to the pathophysiology. For those disorders involving the inter-conversion of glutamine and glutamate, these deviant levels are postulated to play a pivotal pathophysiologic role. For the other IEM however-with the exception of urea cycle defects-abnormal glutamate and glutamine concentrations were rarely reported. To create insight into the clinical consequences of disturbed glutamate metabolism-rather than individual glutamate and glutamine levels-the prevalence of phenotypic abnormalities within the 17 IEM was compared to their prevalence within all Mendelian disorders and subsequently all disorders with metabolic abnormalities notated in the Human Phenotype Ontology (HPO) database. For this, a hierarchical database of all phenotypic abnormalities of the 17 defects in glutamate metabolism based on HPO was created. A neurologic phenotypic spectrum of developmental delay, ataxia, seizures, and hypotonia are common in the inborn errors of enzymes in glutamate metabolism. Additionally, ophthalmologic and skin abnormalities are often present, suggesting that disturbed glutamate homeostasis affects tissues of ectodermal origin: brain, eye, and skin. Reporting glutamate and glutamine concentrations in patients with inborn errors of glutamate metabolism would provide additional insight into the pathophysiology.
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Affiliation(s)
- Lynne Rumping
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Esmee Vringer
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Roderick H. J. Houwen
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Peter M. van Hasselt
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Judith J. M. Jans
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Nanda M. Verhoeven‐Duif
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
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Brown M, Turgeon C, Rinaldo P, Roullet JB, Gibson KM. Temporal metabolomics in dried bloodspots suggests multipathway disruptions in aldh5a1 -/- mice, a model of succinic semialdehyde dehydrogenase deficiency. Mol Genet Metab 2019; 128:397-408. [PMID: 31699650 DOI: 10.1016/j.ymgme.2019.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/26/2019] [Accepted: 10/05/2019] [Indexed: 02/08/2023]
Abstract
Succinic semialdehyde dehydrogenase (SSADH) deficiency (SSADHD; OMIM 271980) is a rare disorder featuring accumulation of neuroactive 4-aminobutyric acid (GABA; γ-aminobutyric acid, derived from glutamic acid) and 4-hydroxybutyric acid (γ-hydroxybutyric acid; GHB, a short-chain fatty acid analogue of GABA). Elevated GABA is predicted to disrupt the GABA shunt linking GABA transamination to the Krebs cycle and maintaining the balance of excitatory:inhibitory neurotransmitters. Similarly, GHB (or a metabolite) is predicted to impact β-oxidation flux. We explored these possibilities employing temporal metabolomics of dried bloodspots (DBS), quantifying amino acids, acylcarnitines, and guanidino- metabolites, derived from aldh5a1+/+, aldh5a1+/- and aldh5a1-/- mice (aldehyde dehydrogenase 5a1 = SSADH) at day of life (DOL) 20 and 42 days. At DOL 20, aldh5a1-/- mice had elevated C6 dicarboxylic (adipic acid) and C14 carnitines and threonine, combined with a significantly elevated ratio of threonine/[aspartic acid + alanine], in comparison to aldh5a1+/+ mice. Conversely, at DOL 42 aldh5a1-/- mice manifested decreased short chain carnitines (C0-C6), valine and glutamine, in comparison to aldh5a1+/+ mice. Guanidino species, including creatinine, creatine and guanidinoacetic acid, evolved from normal levels (DOL 20) to significantly decreased values at DOL 42 in aldh5a1-/- as compared to aldh5a1+/+ mice. Our results provide a novel temporal snapshot of the evolving metabolic profile of aldh5a1-/- mice while highlighting new pathomechanisms in SSADHD.
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Affiliation(s)
- Madalyn Brown
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America
| | - Coleman Turgeon
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Piero Rinaldo
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America.
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Abstract
PURPOSE OF REVIEW Recent advancements in next-generation sequencing (NGS) have enabled techniques such as whole exome sequencing (WES) and whole genome sequencing (WGS) to be used to study paroxysmal movement disorders (PMDs). This review summarizes how the recent genetic advances have altered our understanding of the pathophysiology and treatment of the PMDs. Recently described disease entities are also discussed. RECENT FINDINGS With the recognition of the phenotypic and genotypic heterogeneity that occurs amongst the PMDs, an increasing number of gene mutations are now implicated to cause the disorders. PMDs can also occur as part of a complex phenotype. The increasing complexity of PMDs challenges the way we view and classify them. The identification of new causative genes and their genotype-phenotype correlation will shed more light on the underlying pathophysiology and will facilitate development of genetic testing guidelines and identification of novel drug targets for PMDs.
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Affiliation(s)
- Zheyu Xu
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Che-Kang Lim
- Department of Clinical Translational Research, Singapore General Hospital, Bukit Merah, Singapore, Singapore
- Division of Clinical Immunology and Transfusion Medicine, Department of Laboratory Medicine, Karolinska Institute, Solna, Sweden
| | - Louis C S Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
- Duke-NUS Medical School, 8 College Rd, Singapore, 169857, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
- Duke-NUS Medical School, 8 College Rd, Singapore, 169857, Singapore.
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Kennedy AD, Pappan KL, Donti T, Delgado MR, Shinawi M, Pearson TS, Lalani SR, Craigen WE, Sutton VR, Evans AM, Sun Q, Emrick LT, Elsea SH. 2-Pyrrolidinone and Succinimide as Clinical Screening Biomarkers for GABA-Transaminase Deficiency: Anti-seizure Medications Impact Accurate Diagnosis. Front Neurosci 2019; 13:394. [PMID: 31133775 PMCID: PMC6517487 DOI: 10.3389/fnins.2019.00394] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/05/2019] [Indexed: 11/13/2022] Open
Abstract
Broad-scale untargeted biochemical phenotyping is a technology that supplements widely accepted assays, such as organic acid, amino acid, and acylcarnitine analyses typically utilized for the diagnosis of inborn errors of metabolism. In this study, we investigate the analyte changes associated with 4-aminobutyrate aminotransferase (ABAT, GABA transaminase) deficiency and treatments that affect GABA metabolism. GABA-transaminase deficiency is a rare neurodevelopmental and neurometabolic disorder caused by mutations in ABAT and resulting in accumulation of GABA in the cerebrospinal fluid (CSF). For that reason, measurement of GABA in CSF is currently the primary approach to diagnosis. GABA-transaminase deficiency results in severe developmental delay with intellectual disability, seizures, and movement disorder, and is often associated with death in childhood. Using an untargeted metabolomics platform, we analyzed EDTA plasma, urine, and CSF specimens from four individuals with GABA-transaminase deficiency to identify biomarkers by comparing the biochemical profile of individual patient samples to a pediatric-centric population cohort. Metabolomic analyses of over 1,000 clinical plasma samples revealed a rich source of biochemical information. Three out of four patients showed significantly elevated levels of the molecule 2-pyrrolidinone (Z-score ≥2) in plasma, and whole exome sequencing revealed variants of uncertain significance in ABAT. Additionally, these same patients also had elevated levels of succinimide in plasma, urine, and CSF and/or homocarnosine in urine and CSF. In the analysis of clinical EDTA plasma samples, the levels of succinimide and 2-pyrrolidinone showed a high level of correlation (R = 0.73), indicating impairment in GABA metabolism and further supporting the association with GABA-transaminase deficiency and the pathogenicity of the ABAT variants. Further analysis of metabolomic data across our patient population revealed the association of elevated levels of 2-pyrrolidinone with administration of vigabatrin, a commonly used anti-seizure medication and a known inhibitor of GABA-transaminase. These data indicate that anti-seizure medications may alter the biochemical and metabolomic data, potentially impacting the interpretation and diagnosis for the patient. Further, these data demonstrate the power of combining broad scale genotyping and phenotyping technologies to diagnose inherited neurometabolic disorders and support the use of metabolic phenotyping of plasma to screen for GABA-transaminase deficiency.
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Affiliation(s)
| | | | - Taraka Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Mauricio R Delgado
- Department of Neurology and Neurotherapeutics, Texas Scottish Rite Hospital for Children, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Marwan Shinawi
- Department of Pediatrics, Washington University School of Medicine St. Louis, St. Louis, MO, United States
| | - Toni S Pearson
- Department of Neurology, Washington University School of Medicine St. Louis, St. Louis, MO, United States
| | - Seema R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - William E Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | | | - Qin Sun
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Lisa T Emrick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.,Department of Neurology, 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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Hegde AU, Karnavat PK, Vyas R, DiBacco ML, Ellen Grant P, Pearl PL. GABA Transaminase Deficiency With Survival Into Adulthood. J Child Neurol 2019; 34:216-220. [PMID: 30644311 PMCID: PMC7292229 DOI: 10.1177/0883073818823359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
γ-Aminobutyric acid (GABA)-transaminase deficiency is an ultra-rare disorder of GABA metabolism that was described for decades as an early-onset epileptic encephalopathy plus movement disorder and hypersomnolence with mortality in early childhood. We report 2 affected siblings in adolescence and adulthood, both with profound developmental impairment, intractable epilepsy, movement disorder, and behavioral fluctuations. This considerably expands the phenotype and longevity of this inherited neurotransmitter disease.
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Affiliation(s)
| | | | | | | | - P. Ellen Grant
- Boston Children’s Hospital, Harvard Medical School,
Boston, MA, USA
| | - Phillip L. Pearl
- Boston Children’s Hospital, Harvard Medical School,
Boston, MA, USA
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34
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Morales-Briceño H, Chang FCF, Wong C, Mallawaarachchi A, Wolfe N, Pellegrino da Silva R, Hakonarson H, Sandaradura SA, Guo Y, Christodoulou J, Lagopoulos J, Grattan-Smith P, Fung VSC. Paroxysmal dyskinesias with drowsiness and thalamic lesions in GABA transaminase deficiency. Neurology 2019; 92:94-97. [PMID: 30617166 DOI: 10.1212/wnl.0000000000006744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 10/02/2018] [Indexed: 11/15/2022] Open
Affiliation(s)
- Hugo Morales-Briceño
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Florence C F Chang
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Chong Wong
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Amali Mallawaarachchi
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Nigel Wolfe
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Renata Pellegrino da Silva
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Hakon Hakonarson
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Sarah Annabella Sandaradura
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Yiran Guo
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - John Christodoulou
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Jim Lagopoulos
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Padraic Grattan-Smith
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia
| | - Victor S C Fung
- From the Movement Disorders Unit (H.M.-B., F.C., N.W., V.S.C.F.) and Epilepsy Unit (C.W.), Neurology Department, and Department of Clinical Genetics (A.M., S.A.S.), Westmead Hospital, Australia; Center for Applied Genomics (R.P.d.S., H.H., Y.G.), Children's Hospital of Philadelphia, PA; Discipline of Paediatrics and Child Health (S.A.S.) and Sydney Medical School (H.M.-B., F.C., V.S.C.F.), University of Sydney; Murdoch Children's Research Institute (J.C.), Melbourne; Department of Paediatrics (J.C.), Melbourne Medical School, University of Melbourne; Sunshine Coast Mind and Neuroscience (J.L.), Thompson Institute, University of the Sunshine Coast, Sippy Downs; and Department of Neurology (P.G.-S.), Children's Hospital at Westmead, Sydney, Australia.
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35
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Abstract
Inborn errors of metabolism, also known as inherited metabolic diseases, constitute an important group of conditions presenting with neurologic signs in newborns. They are individually rare but collectively common. Many are treatable through restoration of homeostasis of a disrupted metabolic pathway. Given their frequency and potential for treatment, the clinician should be aware of this group of conditions and learn to identify the typical manifestations of the different inborn errors of metabolism. In this review, we summarize the clinical, laboratory, electrophysiologic, and neuroimaging findings of the different inborn errors of metabolism that can present with florid neurologic signs and symptoms in the neonatal period.
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MESH Headings
- Adult
- Female
- Humans
- Infant, Newborn
- Infant, Newborn, Diseases/diagnosis
- Infant, Newborn, Diseases/diagnostic imaging
- Infant, Newborn, Diseases/physiopathology
- Infant, Newborn, Diseases/therapy
- Metabolism, Inborn Errors/diagnosis
- Metabolism, Inborn Errors/diagnostic imaging
- Metabolism, Inborn Errors/physiopathology
- Metabolism, Inborn Errors/therapy
- Neuroimaging
- Pregnancy
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Affiliation(s)
- Carlos R Ferreira
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States; Rare Disease Institute, Children's National Health System, Washington, DC, United States
| | - Clara D M van Karnebeek
- Departments of Pediatrics and Clinical Genetics, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Pediatrics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
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36
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Kölker S. Metabolism of amino acid neurotransmitters: the synaptic disorder underlying inherited metabolic diseases. J Inherit Metab Dis 2018; 41:1055-1063. [PMID: 29869166 DOI: 10.1007/s10545-018-0201-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/09/2018] [Accepted: 05/14/2018] [Indexed: 10/14/2022]
Abstract
Amino acids are involved in various metabolic pathways and some of them also act as neurotransmitters. Since biosynthesis of L-glutamate and γ-aminobutyric acid (GABA) requires 2-oxoglutarate while 3-phosphoglycerate is the precursor of L-glycine and D-serine, evolutionary selection of these amino acid neurotransmitters might have been driven by their capacity to provide important information about the glycolytic pathway and Krebs cycle. Synthesis and recycling of amino acid neurotransmitters as well as composition and function of their receptors are often compromised in inherited metabolic diseases. For instance, increased plasma L-phenylalanine concentrations impair cerebral biosynthesis of protein and bioamines in phenylketonuria, while elevated cerebral L-phenylalanine directly acts via ionotropic glutamate receptors. In succinic semialdehyde dehydrogenase deficiency, the neurotransmitter GABA and neuromodulatory γ-hydroxybutyric acid are elevated. Chronic hyperGABAergic state results in progressive downregulation of GABAA and GABAB receptors and impaired mitophagy. In glycine encephalopathy, the neurological phenotype is precipitated by L-glycine acting both via cortical NMDA receptors and glycine receptors in spinal cord and brain stem neurons. Serine deficiency syndromes are biochemically characterized by decreased biosynthesis of L-serine, an important neurotrophic factor, and the neurotransmitters D-serine and L-glycine. Supplementation with L-serine and L-glycine has a positive effect on seizure frequency and spasticity, while neurocognitive development can only be improved if treatment starts in utero or immediately postnatally. With novel techniques, the study of synaptic dysfunction in inherited metabolic diseases has become an emerging research field. More and better therapies are needed for these difficult-to-treat diseases.
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Affiliation(s)
- Stefan Kölker
- Division of Pediatric Neurology and Metabolic Medicine, Centre for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.
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37
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Abstract
Metabolomic profiling is an emerging technology in the clinical setting with immediate diagnostic potential for the population of patients with Inborn Errors of Metabolism. We present the metabolomics profile of two ABAT deficiency patients both pre- and posttreatment with flumazenil. ABAT deficiency, also known as GABA-transaminase deficiency, is caused by recessive mutations in the gene ABAT and leads to encephalopathy of variable severity with hypersomnolence, hypotonia, hypomyelination, and seizures. Through metabolomics screening of multiple patient tissues, we identify 2-pyrrolidinone as a biomarker for GABA that is informative in plasma, urine, and CSF. These data will enable noninvasive diagnostic testing for the population of patients with disorders of GABA metabolism.
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38
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Ichikawa K, Tsuji M, Tsuyusaki Y, Tomiyasu M, Aida N, Goto T. Serial Magnetic Resonance Imaging and 1H-Magnetic Resonance Spectroscopy in GABA Transaminase Deficiency: A Case Report. JIMD Rep 2018; 43:7-12. [PMID: 29478219 PMCID: PMC6323023 DOI: 10.1007/8904_2018_95] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/20/2018] [Accepted: 02/06/2018] [Indexed: 02/07/2023] Open
Abstract
Gamma-aminobutyric acid transaminase (GABA-T) deficiency is a rare, autosomal recessive disorder characterized by severe psychomotor retardation, early-onset epileptic encephalopathy, intractable seizures, hypotonia, and hyperreflexia. The disease is caused by mutation in the 4-aminobutyrate aminotransferase (ABAT) gene, which encodes an enzyme involved in GABA catabolism. In this chapter, a 10-year follow-up of GABA-T deficiency in a rare case of a long-term survivor patient is discussed. The patient showed a progression of clinical phases with increasing age. In infancy, the patient developed psychomotor retardation and recurrent encephalopathic episodes associated with febrile illness. In early childhood, the patient presented with refractory involuntary and hyperkinetic movements and dystonic hypertonicity. In childhood, the patient gradually progressed into the chronic stable phase of the condition. Magnetic resonance imaging demonstrated high signal intensity on diffusion-weighted images involving the internal and external capsules and cerebral white matter in infancy which disappeared gradually by the age of 3 years, and showed subsequently diffuse brain atrophy in childhood. Using proton magnetic resonance spectroscopy, GABA levels in the basal ganglia were shown to be markedly elevated at the age of 1-2 years, and subsequently decreased with increasing age (toward 5 years). These findings suggest that the encephalopathic episodes in infancy and clinical severity of involuntary and hyperkinetic movements may be correlated with levels of GABA in the basal ganglia. The high levels of GABA in the cerebrospinal fluid remained unaltered, whereas levels of GABA in the serum decreased during childhood. Further investigation of long-term clinical surveillance may improve the understanding of GABA-T deficiency.
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Affiliation(s)
- Kazushi Ichikawa
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
| | - Megumi Tsuji
- Division of Neurology, Kanagawa Children’s Medical Center, Yokohama, Japan
| | - Yu Tsuyusaki
- Division of Neurology, Kanagawa Children’s Medical Center, Yokohama, Japan
| | - Moyoko Tomiyasu
- Department of Radiology, Kanagawa Children’s Medical Center, Yokohama, Japan ,Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, Chiba, Japan ,Research Center for Child Mental Development, Chiba University, Chiba, Japan
| | - Noriko Aida
- Department of Radiology, Kanagawa Children’s Medical Center, Yokohama, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children’s Medical Center, Yokohama, Japan
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39
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Vogel KR, Ainslie GR, McConnell A, Roullet JB, Gibson KM. Toxicologic/transport properties of NCS-382, a γ-hydroxybutyrate (GHB) receptor ligand, in neuronal and epithelial cells: Therapeutic implications for SSADH deficiency, a GABA metabolic disorder. Toxicol In Vitro 2017; 46:203-212. [PMID: 29031482 DOI: 10.1016/j.tiv.2017.10.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/24/2017] [Accepted: 10/10/2017] [Indexed: 12/16/2022]
Abstract
We report the in vitro assessment of pharmacotoxicity for the high-affinity GHB receptor ligand, NCS-382, using neuronal stem cells derived from mice with a targeted deletion of the aldehyde dehydrogenase 5a1 gene (succinic semialdehyde dehydrogenase(SSADH)-deficient mice). These animals represent a phenocopy of the human disorder of GABA metabolism, SSADH deficiency, that metabolically features accumulation of both GABA and the GABA-analog γ-hydroxybutyric acid in conjunction with a nonspecific neurological phenotype. We demonstrate for the first time using MDCK cells that NCS-382 is actively transported and capable of inhibiting GHB transport. Following these in vitro assays with in vivo studies in aldh5a1-/- mice, we found the ratio of brain/liver GHB to be unaffected by chronic NCS-382 administration (300mg/kg; 7 consecutive days). Employing a variety of cellular parameters (reactive oxygen and superoxide species, ATP production and decay, mitochondrial and lysosomal number, cellular viability and necrosis), we demonstrate that up to 1mM NCS-382 shows minimal evidence of pharmacotoxicity. As well, studies at the molecular level indicate that the effects of NCS-382 at 0.5mM are minimally toxic as evaluated using gene expression assay. The cumulative data provides increasing confidence that NCS-382 could eventually be considered in the therapeutic armament for heritable SSADH deficiency.
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Affiliation(s)
- K R Vogel
- Department of Neuroscience, Wisconsin Institute of Medical Research (WIMR), Madison, WI, United States
| | - G R Ainslie
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States
| | | | - J-B Roullet
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States
| | - K M Gibson
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States.
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