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Gauer L, Baer S, Valenti-Hirsch MP, De Saint-Martin A, Hirsch E. Drug-resistant generalized epilepsies: Revisiting the frontiers of idiopathic generalized epilepsies. Rev Neurol (Paris) 2024; 180:290-297. [PMID: 38508955 DOI: 10.1016/j.neurol.2024.03.001] [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: 12/21/2023] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
The 2017 International League Against Epilepsy (ILAE) classification suggested that the term "genetic generalized epilepsies" (GGEs) should be used for the broad group of epilepsies with so-called "generalized" seizure types and "generalized" spike-wave activity on EEG, based on a presumed genetic etiology. Within this framework, idiopathic generalized epilepsies (IGEs) are described as a subset of GGEs and include only four epileptic syndromes: childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. The recent 2022 ILAE definition of IGEs is based on the current state of knowledge and reflects a community consensus and is designed to evolve as knowledge advances. The term "frontiers of IGEs" refers to the actual limits of our understanding of these four syndromes. Indeed, among patients presenting with a syndrome compatible with the 2022 definition of IGEs, we still observe a significant proportion of patients presenting with specific clinical features, refractory seizures, or drug-resistant epilepsies. This leads to the discussion of the boundaries of IGEs and GGEs, or what is accepted within a clinical spectrum of a definite IGE. Here, we discuss several entities that have been described in the literature for many years and that may either constitute rare features of IGEs or a distinct differential diagnosis. Their recognition by clinicians may allow a more individualized approach and improve the management of patients presenting with such entities.
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Affiliation(s)
- L Gauer
- Hôpitaux Universitaires de Strasbourg, Neurology department, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Reference Centre for Rare Epilepsies (CRéER), Strasbourg, France.
| | - S Baer
- Hôpitaux Universitaires de Strasbourg, Pediatric Neurology Department, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Reference Centre for Rare Epilepsies (CRéER), Strasbourg, France
| | - M-P Valenti-Hirsch
- Hôpitaux Universitaires de Strasbourg, Neurology department, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Reference Centre for Rare Epilepsies (CRéER), Strasbourg, France
| | - A De Saint-Martin
- Hôpitaux Universitaires de Strasbourg, Pediatric Neurology Department, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Reference Centre for Rare Epilepsies (CRéER), Strasbourg, France
| | - E Hirsch
- Hôpitaux Universitaires de Strasbourg, Neurology department, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Reference Centre for Rare Epilepsies (CRéER), Strasbourg, France
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2
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Nors JW, Endres Z, Goldschen-Ohm MP. GABA A receptor subunit M2-M3 linkers have asymmetric roles in pore gating and diazepam modulation. Biophys J 2024:S0006-3495(24)00136-X. [PMID: 38400541 DOI: 10.1016/j.bpj.2024.02.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/19/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024] Open
Abstract
GABAA receptors (GABAARs) are neurotransmitter-gated ion channels critical for inhibitory synaptic transmission as well as the molecular target for benzodiazepines (BZDs), one of the most widely prescribed class of psychotropic drugs today. Despite structural insight into the conformations underlying functional channel states, the detailed molecular interactions involved in conformational transitions and the physical basis for their modulation by BZDs are not fully understood. We previously identified that alanine substitution at the central residue in the α1 subunit M2-M3 linker (V279A) enhances the efficiency of linkage between the BZD site and the pore gate. Here, we expand on this work by investigating the effect of alanine substitutions at the analogous positions in the M2-M3 linkers of β2 (I275A) and γ2 (V290A) subunits, which together with α1 comprise typical heteromeric α1β2γ2 synaptic GABAARs. We find that these mutations confer subunit-specific effects on the intrinsic pore closed-open equilibrium and its modulation by the BZD diazepam (DZ). The mutations α1(V279A) or γ2(V290A) bias the channel toward a closed conformation, whereas β2(I275A) biases the channel toward an open conformation to the extent that the channel becomes leaky and opens spontaneously in the absence of agonist. In contrast, only α1(V279A) enhances the efficiency of DZ-to-pore linkage, whereas mutations in the other two subunits have no effect. These observations show that the central residue in the M2-M3 linkers of distinct subunits in synaptic α1β2γ2 GABAARs contribute asymmetrically to the intrinsic closed-open equilibrium and its modulation by DZ.
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Affiliation(s)
- Joseph W Nors
- Department of Neuroscience, University of Texas at Austin, Austin, Texas; Department of Molecular and Cellular Physiology, Stanford University, Stanford, California
| | - Zachary Endres
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
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3
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Richardson RJ, Petrou S, Bryson A. Established and emerging GABA A receptor pharmacotherapy for epilepsy. Front Pharmacol 2024; 15:1341472. [PMID: 38449810 PMCID: PMC10915249 DOI: 10.3389/fphar.2024.1341472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/07/2024] [Indexed: 03/08/2024] Open
Abstract
Drugs that modulate the GABAA receptor are widely used in clinical practice for both the long-term management of epilepsy and emergency seizure control. In addition to older medications that have well-defined roles for the treatment of epilepsy, recent discoveries into the structure and function of the GABAA receptor have led to the development of newer compounds designed to maximise therapeutic benefit whilst minimising adverse effects, and whose position within the epilepsy pharmacologic armamentarium is still emerging. Drugs that modulate the GABAA receptor will remain a cornerstone of epilepsy management for the foreseeable future and, in this article, we provide an overview of the mechanisms and clinical efficacy of both established and emerging pharmacotherapies.
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Affiliation(s)
- Robert J. Richardson
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Praxis Precision Medicines, Boston, MA, United States
| | - Alexander Bryson
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC, Australia
- Department of Neurology, Eastern Health, Melbourne, VIC, Australia
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4
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Modarres Mousavi SM, Alipour F, Noorbakhsh F, Jafarian M, Ghadipasha M, Gharehdaghi J, Kellinghaus C, Speckmann EJ, Stummer W, Khaleghi Ghadiri M, Gorji A. Clinical Correlation of Altered Molecular Signatures in Epileptic Human Hippocampus and Amygdala. Mol Neurobiol 2024; 61:725-752. [PMID: 37658249 PMCID: PMC10861640 DOI: 10.1007/s12035-023-03583-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 08/14/2023] [Indexed: 09/03/2023]
Abstract
Widespread alterations in the expression of various genes could contribute to the pathogenesis of epilepsy. The expression levels of various genes, including major inhibitory and excitatory receptors, ion channels, cell type-specific markers, and excitatory amino acid transporters, were assessed and compared between the human epileptic hippocampus and amygdala, and findings from autopsy controls. Moreover, the potential correlation between molecular alterations in epileptic brain tissues and the clinical characteristics of patients undergoing epilepsy surgery was evaluated. Our findings revealed significant and complex changes in the expression of several key regulatory genes in both the hippocampus and amygdala of patients with intractable epilepsy. The expression changes in various genes differed considerably between the epileptic hippocampus and amygdala. Different correlation patterns were observed between changes in gene expression and clinical characteristics, depending on whether the patients were considered as a whole or were subdivided. Altered molecular signatures in different groups of epileptic patients, defined within a given category, could be viewed as diagnostic biomarkers. Distinct patterns of molecular changes that distinguish these groups from each other appear to be associated with epilepsy-specific functional consequences.
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Affiliation(s)
| | - Fatemeh Alipour
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Farshid Noorbakhsh
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Maryam Jafarian
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Masoud Ghadipasha
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | - Jaber Gharehdaghi
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | | | - Erwin-Josef Speckmann
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany
- Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Walter Stummer
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | | | - Ali Gorji
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Department of Neuroscience, Mashhad University of Medical Sciences, Mashhad, Iran.
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5
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Harraz OF, Delpire E. Recent insights into channelopathies. Physiol Rev 2024; 104:23-31. [PMID: 37561136 DOI: 10.1152/physrev.00022.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/12/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023] Open
Affiliation(s)
- Osama F Harraz
- Department of Pharmacology, Larner College of Medicine, Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, Vermont, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical School, Nashville, Tennessee, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, Tennessee, United States
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Liu N, Li J, Gao K, Perszyk RE, Zhang J, Wang J, Wu Y, Jenkins A, Yuan H, Traynelis SF, Jiang Y. De novo CLPTM1 variants with reduced GABA A R current response in patients with epilepsy. Epilepsia 2023; 64:2968-2981. [PMID: 37577761 PMCID: PMC10840799 DOI: 10.1111/epi.17746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
OBJECTIVE To investigate the clinical features and potential pathogenesis mechanism of de novo CLPTM1 variants associated with epilepsy. METHODS Identify de novo genetic variants associated with epilepsy by reanalyzing trio-based whole-exome sequencing data. We analyzed the clinical characteristics of patients with these variants and performed functional in vitro studies in cells expressing mutant complementary DNA for these variants using whole-cell voltage-clamp current recordings and outside-out patch-clamp recordings from transiently transfected human embryonic kidney (HEK) cells. RESULTS Two de novo missense variants related to epilepsy were identified in the CLPTM1 gene. Functional studies indicated that CLPTM1-p.R454H and CLPTM1-p.R568Q variants reduced the γ-aminobutyric acid A receptor (GABAA R) current response amplitude recorded under voltage clamp compared to the wild-type receptors. These variants also reduced the charge transfer and altered the time course of desensitization and deactivation following rapid removal of GABA. The surface expression of the GABAA R γ2 subunit from the CLPTM1-p.R568Q group was significantly reduced compared to CLPTM1-WT. SIGNIFICANCE This is the first report of functionally relevant variants within the CLPTM1 gene. Patch-clamp recordings showed that these de novo CLPTM1 variants reduce GABAA R currents and charge transfer, which should promote excitation and hypersynchronous activity. This study may provide insights into the molecular mechanisms of the CLPTM1 variants underlying the patients' phenotypes, as well as for exploring potential therapeutic targets for epilepsy.
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Affiliation(s)
- Nana Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Jinliang Li
- Department of Pediatrics, Central People's Hospital of Zhanjiang, Guangdong, China
| | - Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jing Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Ye Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Andrew Jenkins
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, Connecticut, USA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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7
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Mortensen M, Xu Y, Shehata MA, Krall J, Ernst M, Frølund B, Smart TG. Pregnenolone sulfate analogues differentially modulate GABA A receptor closed/desensitised states. Br J Pharmacol 2023; 180:2482-2499. [PMID: 37194503 PMCID: PMC10952582 DOI: 10.1111/bph.16143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 02/07/2023] [Accepted: 05/05/2023] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND AND PURPOSE GABAA receptors are regulated by numerous classes of allosteric modulators. However, regulation of receptor macroscopic desensitisation remains largely unexplored and may offer new therapeutic opportunities. Here, we report the emerging potential for modulating desensitisation with analogues of the endogenous inhibitory neurosteroid, pregnenolone sulfate. EXPERIMENTAL APPROACH New pregnenolone sulfate analogues were synthesised incorporating various heterocyclic substitutions located at the C-21 position on ring D. The pharmacological profiles of these compounds were assessed using electrophysiology and recombinant GABAA receptors together with mutagenesis, molecular dynamics simulations, structural modelling and kinetic simulations. KEY RESULTS All seven analogues retained a negative allosteric modulatory capability whilst exhibiting diverse potencies. Interestingly, we observed differential effects on GABA current decay by compounds incorporating either a six- (compound 5) or five-membered heterocyclic ring (compound 6) on C-21, which was independent of their potencies as inhibitors. We propose that differences in molecular charges, and the targeted binding of analogues to specific states of the GABAA receptor, are the most likely cause of the distinctive functional profiles. CONCLUSIONS AND IMPLICATIONS Our findings reveal that heterocyclic addition to inhibitory neurosteroids not only affected their potency and macroscopic efficacy but also affected innate receptor mechanisms that underlie desensitisation. Acute modulation of macroscopic desensitisation will determine the degree and duration of GABA inhibition, which are vital for the integration of neural circuit activity. Discovery of this form of modulation could present an opportunity for next-generation GABAA receptor drug design and development.
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Affiliation(s)
- Martin Mortensen
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUK
| | - Yue Xu
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Mohamed A. Shehata
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jacob Krall
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Present address:
Xellia Pharmaceuticals ApSCopenhagenDenmark
| | - Margot Ernst
- Department of Pathology of the Nervous System, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Bente Frølund
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Trevor G. Smart
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUK
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8
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Absalom NL, Lin SXN, Liao VWY, Chua HC, Møller RS, Chebib M, Ahring PK. GABA A receptors in epilepsy: Elucidating phenotypic divergence through functional analysis of genetic variants. J Neurochem 2023. [PMID: 37621067 DOI: 10.1111/jnc.15932] [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: 05/21/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/26/2023]
Abstract
Normal brain function requires a tightly regulated balance between excitatory and inhibitory neurotransmissions. γ-Aminobutyric acid type A (GABAA ) receptors represent the major class of inhibitory ion channels in the mammalian brain. Dysregulation of these receptors and/or their associated pathways is strongly implicated in the pathophysiology of epilepsy. To date, hundreds of different GABAA receptor subunit variants have been associated with epilepsy, making them a prominent cause of genetically linked epilepsy. While identifying these genetic variants is crucial for accurate diagnosis and effective genetic counselling, it does not necessarily lead to improved personalised treatment options. This is because the identification of a variant does not reveal how the function of GABAA receptors is affected. Genetic variants in GABAA receptor subunits can cause complex changes to receptor properties resulting in various degrees of gain-of-function, loss-of-function or a combination of both. Understanding how variants affect the function of GABAA receptors therefore represents an important first step in the ongoing development of precision therapies. Furthermore, it is important to ensure that functional data are produced using methodologies that allow genetic variants to be classified using clinical guidelines such as those developed by the American College of Medical Genetics and Genomics. This article will review the current knowledge in the field and provide recommendations for future functional analysis of genetic GABAA receptor variants.
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Affiliation(s)
- Nathan L Absalom
- School of Science, University of Western Sydney, Sydney, New South Wales, Australia
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Susan X N Lin
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Vivian W Y Liao
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Han C Chua
- Brain and Mind Centre, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Mary Chebib
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Philip K Ahring
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
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9
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Li L, Yuan L, Zheng W, Yang Y, Deng X, Song Z, Deng H. An SCN1A gene missense variant in a Chinese Tujia ethnic family with genetic epilepsy with febrile seizures plus. Front Neurol 2023; 14:1229569. [PMID: 37576022 PMCID: PMC10412811 DOI: 10.3389/fneur.2023.1229569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 06/30/2023] [Indexed: 08/15/2023] Open
Abstract
Genetic epilepsy with febrile seizures plus (GEFSP) is a familial epileptic syndrome that is genetically heterogeneous and inherited in an autosomal dominant form in most cases. To date, at least seven genes have been reported to associate with GEFSP. This study aimed to identify the disease-causing variant in a Chinese Tujia ethnic family with GEFSP by using whole exome sequencing, Sanger sequencing, and in silico prediction. A heterozygous missense variant c.5725A>G (p.T1909A) was identified in the sodium voltage-gated channel alpha subunit 1 gene (SCN1A) coding region. The variant co-segregated with the GEFSP phenotype in this family, and it was predicted as disease-causing by multiple in silico programs, which was proposed as the genetic cause of GEFSP, further genetically diagnosed as GEFSP2. These findings expand the genetic and phenotypic spectrum of GEFSP and should contribute to genetic diagnoses, personalized therapies, and prognoses.
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Affiliation(s)
- Ling Li
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yuan
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
- Disease Genome Research Center, Central South University, Changsha, China
| | - Wen Zheng
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yan Yang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
- Disease Genome Research Center, Central South University, Changsha, China
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10
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Peek AL, Rebbeck TJ, Leaver AM, Foster SL, Refshauge KM, Puts NA, Oeltzschner G. A comprehensive guide to MEGA-PRESS for GABA measurement. Anal Biochem 2023; 669:115113. [PMID: 36958511 PMCID: PMC10805000 DOI: 10.1016/j.ab.2023.115113] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/25/2023]
Abstract
The aim of this guideline is to provide a series of evidence-based recommendations that allow those new to using MEGA-PRESS to produce high-quality data for the measurement of GABA levels using edited magnetic resonance spectroscopy with the MEGA-PRESS sequence at 3T. GABA is the main inhibitory neurotransmitter of the central nervous system and has been increasingly studied due to its relevance in many clinical disorders of the central nervous system. MEGA-PRESS is the most widely used method for quantification of GABA at 3T, but is technically challenging and operates at a low signal-to-noise ratio. Therefore, the acquisition of high-quality MRS data relies on avoiding numerous pitfalls and observing important caveats. The guideline was developed by a working party that consisted of experts in MRS and experts in guideline development and implementation, together with key stakeholders. Strictly following a translational framework, we first identified evidence using a systematically conducted scoping literature review, then synthesized and graded the quality of evidence that formed recommendations. These recommendations were then sent to a panel of 21 world leaders in MRS for feedback and approval using a modified-Delphi process across two rounds. The final guideline consists of 23 recommendations across six domains essential for GABA MRS acquisition (Parameters, Practicalities, Data acquisition, Confounders, Quality/reporting, Post-processing). Overall, 78% of recommendations were formed from high-quality evidence, and 91% received agreement from over 80% of the expert panel. These 23 expert-reviewed recommendations and accompanying extended documentation form a readily useable guideline to allow those new to using MEGA-PRESS to design appropriate MEGA-PRESS study protocols and generate high-quality data.
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Affiliation(s)
- A L Peek
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia.
| | - T J Rebbeck
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia.
| | - A M Leaver
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia.
| | - S L Foster
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; Department of Radiology, Westmead Hospital, Hawkesbury Road, Westmead, New South Wales, 2145, Australia.
| | - K M Refshauge
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia.
| | - N A Puts
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, Kings College London, UK.
| | - G Oeltzschner
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, 21205, United States.
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11
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Rosenberg EC, Chamberland S, Bazelot M, Nebet ER, Wang X, McKenzie S, Jain S, Greenhill S, Wilson M, Marley N, Salah A, Bailey S, Patra PH, Rose R, Chenouard N, Sun SED, Jones D, Buzsáki G, Devinsky O, Woodhall G, Scharfman HE, Whalley BJ, Tsien RW. Cannabidiol modulates excitatory-inhibitory ratio to counter hippocampal hyperactivity. Neuron 2023; 111:1282-1300.e8. [PMID: 36787750 DOI: 10.1016/j.neuron.2023.01.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/27/2022] [Accepted: 01/20/2023] [Indexed: 02/15/2023]
Abstract
Cannabidiol (CBD), a non-euphoric component of cannabis, reduces seizures in multiple forms of pediatric epilepsies, but the mechanism(s) of anti-seizure action remain unclear. In one leading model, CBD acts at glutamatergic axon terminals, blocking the pro-excitatory actions of an endogenous membrane phospholipid, lysophosphatidylinositol (LPI), at the G-protein-coupled receptor GPR55. However, the impact of LPI-GPR55 signaling at inhibitory synapses and in epileptogenesis remains underexplored. We found that LPI transiently increased hippocampal CA3-CA1 excitatory presynaptic release probability and evoked synaptic strength in WT mice, while attenuating inhibitory postsynaptic strength by decreasing GABAARγ2 and gephyrin puncta. LPI effects at excitatory and inhibitory synapses were eliminated by CBD pre-treatment and absent after GPR55 deletion. Acute pentylenetrazole-induced seizures elevated GPR55 and LPI levels, and chronic lithium-pilocarpine-induced epileptogenesis potentiated LPI's pro-excitatory effects. We propose that CBD exerts potential anti-seizure effects by blocking LPI's synaptic effects and dampening hyperexcitability.
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Affiliation(s)
- Evan C Rosenberg
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Simon Chamberland
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Michael Bazelot
- School of Chemistry, Food and Nutritional Sciences, and Pharmacy, University of Reading, Hopkins Life Science Building, Whiteknights, Reading, Berks RG6 6AP, UK; GW Research Ltd, Histon, Cambridge, UK
| | - Erica R Nebet
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Xiaohan Wang
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Sam McKenzie
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Swati Jain
- Departments of Child and Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA; Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Bldg. 35, Orangeburg, NY 10962, USA
| | - Stuart Greenhill
- Aston Neuroscience Institute, School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Max Wilson
- Aston Neuroscience Institute, School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Nicole Marley
- Aston Neuroscience Institute, School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Alejandro Salah
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Shanice Bailey
- School of Chemistry, Food and Nutritional Sciences, and Pharmacy, University of Reading, Hopkins Life Science Building, Whiteknights, Reading, Berks RG6 6AP, UK
| | - Pabitra Hriday Patra
- School of Chemistry, Food and Nutritional Sciences, and Pharmacy, University of Reading, Hopkins Life Science Building, Whiteknights, Reading, Berks RG6 6AP, UK
| | - Rebecca Rose
- Department of Advanced Research Technologies, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Nicolas Chenouard
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Simón E D Sun
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Drew Jones
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - György Buzsáki
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Orrin Devinsky
- Department of Neurology, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA
| | - Gavin Woodhall
- Aston Neuroscience Institute, School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Helen E Scharfman
- Departments of Child and Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA; Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Bldg. 35, Orangeburg, NY 10962, USA
| | - Benjamin J Whalley
- School of Chemistry, Food and Nutritional Sciences, and Pharmacy, University of Reading, Hopkins Life Science Building, Whiteknights, Reading, Berks RG6 6AP, UK; GW Research Ltd, Histon, Cambridge, UK
| | - Richard W Tsien
- Department of Neuroscience & Physiology and Neuroscience Institute, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA; Department of Neurology, NYU Langone Medical Center, 435 E 30th St, New York, NY 10016, USA.
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12
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Hernandez CC, Shen Y, Hu N, Shen W, Narayanan V, Ramsey K, He W, Zou L, Macdonald RL. GABRG2 Variants Associated with Febrile Seizures. Biomolecules 2023; 13:414. [PMID: 36979350 PMCID: PMC10046037 DOI: 10.3390/biom13030414] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Febrile seizures (FS) are the most common form of epilepsy in children between six months and five years of age. FS is a self-limited type of fever-related seizure. However, complicated prolonged FS can lead to complex partial epilepsy. We found that among the GABAA receptor subunit (GABR) genes, most variants associated with FS are harbored in the γ2 subunit (GABRG2). Here, we characterized the effects of eight variants in the GABAA receptor γ2 subunit on receptor biogenesis and channel function. Two-thirds of the GABRG2 variants followed the expected autosomal dominant inheritance in FS and occurred as missense and nonsense variants. The remaining one-third appeared as de novo in the affected probands and occurred only as missense variants. The loss of GABAA receptor function and dominant negative effect on GABAA receptor biogenesis likely caused the FS phenotype. In general, variants in the GABRG2 result in a broad spectrum of phenotypic severity, ranging from asymptomatic, FS, genetic epilepsy with febrile seizures plus (GEFS+), and Dravet syndrome individuals. The data presented here support the link between FS, epilepsy, and GABRG2 variants, shedding light on the relationship between the variant topological occurrence and disease severity.
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Affiliation(s)
- Ciria C. Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yanwen Shen
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Ningning Hu
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Wen He
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Liping Zou
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Robert L. Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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13
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Novel variants in GABA A receptor subunits: A possible association with benzodiazepine resistance in patients with drug-resistant epilepsy. Epilepsy Res 2023; 189:107056. [PMID: 36469977 DOI: 10.1016/j.eplepsyres.2022.107056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/12/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022]
Abstract
Benzodiazepines (BDZ) such as diazepam and lorazepam are popular as first-line treatment for acute seizures due to their rapid action and high efficacy. However, long-term usage of BDZ leads to benzodiazepine resistance, a phenomenon whose underlying mechanisms are still being investigated. One of the hypothesised mechanisms contributing to BDZ resistance is the presence of mutations in benzodiazepine-sensitive receptors. While a few genetic variants have been reported previously, knowledge of relevant pathogenic variants is still scarce. We used Sanger Sequencing to detect variants in the ligand-binding domain of BDZ-sensitive GABAA receptor subunits α1-3 and 5 expressed in resected brain tissues of drug-resistant epilepsy (DRE) patients with a history of BDZ resistance and found two previously unreported predicted pathogenic frameshifting variants - NM_000807.4(GABRA2):c.367_368insG and NM_000810.4(GABRA5):c.410del - significantly enriched in these patients. The findings were further explored in resected DRE brain tissues through cellular electrophysiological experiments.
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14
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Kuanyshbek A, Wang M, Andersson Å, Tuifua M, Palmer EE, Sachdev RK, Mu TW, Vetter I, Keramidas A. Anti-seizure mechanisms of midazolam and valproate at the β2(L51M) variant of the GABA A receptor. Neuropharmacology 2022; 221:109295. [PMID: 36257447 PMCID: PMC9981329 DOI: 10.1016/j.neuropharm.2022.109295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022]
Abstract
Genetic sequencing is identifying an expanding number of variants of GABAA receptors associated with human epilepsies. We identified a new de novo variant of the β2 subunit (β2L51M) of the inhibitory GABAA receptor associated with seizures. Our analysis determined the pathogenicity of the variant and the effects of anti-seizure medications. Our data demonstrates that the variant reduced cell surface trafficking and peak GABA-gated currents. Synaptic currents mediated by variant-containing receptors decayed faster than wild-type and single receptor currents showed that the variant shortened the duration of receptor activity by decreasing receptor open times. We tested the effects of the anti-seizure medications, midazolam, carbamazepine and valproate and found that all three enhance variant receptor surface expression. Additionally, midazolam restored receptor function by increasing single receptor active periods and synaptic current decay times towards wild-type levels. By contrast, valproate increased synaptic peak currents, event frequency and promoted synaptic bursting. Our study identifies a new disease-causing variant to the GABAA receptor, profiles its pathogenic effects and demonstrates how anti-seizure drugs correct its functional deficits.
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Affiliation(s)
- Alibek Kuanyshbek
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Meng Wang
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Åsa Andersson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Marie Tuifua
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Elizabeth E Palmer
- Sydney Children's Hospital Network, Randwick Sydney Australia and School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Rani K Sachdev
- Sydney Children's Hospital Network, Randwick Sydney Australia and School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Ting-Wei Mu
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, 4102, Australia
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
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15
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Alghamdi MA, Al-Eitan LN, Asiri A, Rababa'h DM, Alqahtani SA, Aldarami MS, Alsaeedi MA, Almuidh RS, Alzahrani AA, Sakah AH, El Nashar EM, Otaif MY, Abdel Ghaffar NF. Association of sodium voltage-gated channel genes polymorphisms with epilepsy risk and prognosis in the Saudi population. Ann Med 2022; 54:1938-1951. [PMID: 35801810 PMCID: PMC9367647 DOI: 10.1080/07853890.2022.2096257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Epilepsy is a heterogeneous complex condition that involve the human brain. Genetic predisposition to epilepsy is a fundamental factor of the disorder aetiology. The sodium voltage-gated channel (SCN) genes variants are critical biomarker for the epilepsy development and progression. In this study, we aimed to investigate the association of several SNCs genetic polymorphisms with epilepsy risk and their intrudance of the disease prognosis. METHODS Blood samples were withdrawn from 296 Epilepsy patients in addition to 293 healthy matched participants prior to DNA extraction. PCR-sequencing was used for genotyping analysis. Genotyping outputs were then statistically analysed for genotype/phenotype evaluation. RESULTS Within SCN1A gene we found that the rs6432861 (p = 0.014) was in correlation with the risk of epilepsy. In addition, both rs4667485 and rs1469649 of SCN2A gene were significantly correlated to epilepsy risk for both allelic (4e-4 and 1e-3) and genotypic (1e-3 and 5e-3). Moreover, the haplotype analysis showed that the GATGCTCGGTTTCGCTACGCA haplotype of SCN2A gene was significantly related to epilepsy increased risk, p = 6e-3, OR (CI) = 2.02 (1.23-3.31). In relevant to our finding, many of the investigated SCNs variants in the current study were related to several clinical features of epilepsy. CONCLUSION In light of our results, we infer that SCN genes polymorphisms are strong candidates for epilepsy development and progression. Furthermore, these variant are essential for the disorder prognosis and medications outcomes.Key MessagesGenetic polymorphisms of sodium channels SCN1A, SCN2A and SCN3A were found to be associated with the risk of epilepsy.SCN1B polymorphisms were found to be correlated to epilepsy reduced risk.SCNs variants are involved in the epilepsy prognosis and response to treatment.
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Affiliation(s)
- Mansour A Alghamdi
- Department of Anatomy, College of Medicine, King Khalid University, Abha, Saudi Arabia.,Genomics and Personalized Medicine Unit, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Laith N Al-Eitan
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan.,Department of Biotechnology and Genetic Engineering, Jordan University of Science and Technology, Irbid, Jordan
| | - Ashwag Asiri
- Department of Child Health, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Doaa M Rababa'h
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Sultan A Alqahtani
- Neurology Department, Neuroscience Centre, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mohammed S Aldarami
- Neurology Department, Neuroscience Centre, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Manar A Alsaeedi
- Neurology Department, Neuroscience Centre, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Raghad S Almuidh
- Neurology Department, Neuroscience Centre, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Abdulbari A Alzahrani
- Neurology Department, Neuroscience Centre, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Ahmad H Sakah
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Eman Mohamad El Nashar
- Department of Anatomy, College of Medicine, King Khalid University, Abha, Saudi Arabia.,Department of Histology and Cell Biology, Faculty of Medicine, Benha University, Benha, Egypt
| | - Mansour Y Otaif
- Department of Pediatric, Neurology section, Abha Maternity and Childern Hospital, Abha, Saudi Arabia
| | - Nawal F Abdel Ghaffar
- Neurology Department, Kasr Al Ainy Hospital, Faculty of Medicine, Cairo University, Giza, Egypt.,Neurology Department, Aseer Central Hospital, Abha, Saudi Arabia
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16
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Saleem T, Maqbool H, Sheikh N, Tayyeb A, Mukhtar M, Ashfaq A. GABRG2 C588T Polymorphism Is Associated with Idiopathic Generalized Epilepsy but Not with Antiepileptic Drug Resistance in Pakistani Cohort. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3460792. [PMID: 36425336 PMCID: PMC9681559 DOI: 10.1155/2022/3460792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 10/19/2022] [Accepted: 10/29/2022] [Indexed: 08/30/2023]
Abstract
Idiopathic generalized epilepsy (IGE) is the most prevalent type of epilepsy with genetic origin. Mutations in ion channel genes have been identified as a common cause of IGE. Several studies have reported various epilepsy risk variants of GABRG2 (gamma-aminobutyric acid type A receptor subunit gamma2 subunit) gene in different ethnic groups, but the results are inconsistent. The purpose of this case-control research is to determine if GABRG2 polymorphisms contribute to IGE susceptibility and antiepileptic drug resistance in Pakistani population. For this purpose, we genotyped exon2, exon5 (C540T and C588T), exon7 (T813C), exon8 (K289M), and exon9 of GABRG2 gene by restriction fragment length polymorphism and Sanger's sequencing in 87 drug-responsive idiopathic generalized epilepsy patients, 55 drug-resistant epilepsy patients, and 83 healthy controls. Restriction fragment length polymorphism (RFLP) and sequencing results indicated only C588T polymorphism in the studied subjects. The comparison of genotypic and allelic frequencies showed significant differences between IGE patients and control groups (P = 0.008 and odds ratio = 4.2) and nonsignificant association of C588T polymorphism in antiseizure medication-resistant patients (P = 0.9). Our findings showed that C588T polymorphism of GABRG2 is a risk variant for IGE in Pakistani population. Further studies are required to validate the results.
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Affiliation(s)
- Tayyaba Saleem
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Hafsa Maqbool
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Nadeem Sheikh
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Asima Tayyeb
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Maryam Mukhtar
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Aqsa Ashfaq
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
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17
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Leng X, Zhang T, Guan Y, Tang M. Genotype and phenotype analysis of epilepsy caused by ADGRV1 mutations in Chinese children. Seizure 2022; 103:108-114. [DOI: 10.1016/j.seizure.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/07/2022] [Accepted: 11/10/2022] [Indexed: 11/13/2022] Open
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18
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Castro PA, Pinto-Borguero I, Yévenes GE, Moraga-Cid G, Fuentealba J. Antiseizure medication in early nervous system development. Ion channels and synaptic proteins as principal targets. Front Pharmacol 2022; 13:948412. [PMID: 36313347 PMCID: PMC9614143 DOI: 10.3389/fphar.2022.948412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/05/2022] [Indexed: 12/04/2022] Open
Abstract
The main strategy for the treatment of epilepsy is the use of pharmacological agents known as antiseizure medication (ASM). These drugs control the seizure onset and improves the life expectancy and quality of life of patients. Several ASMs are contraindicated during pregnancy, due to a potential teratogen risk. For this reason, the pharmacological treatments of the pregnant Women with Epilepsy (WWE) need comprehensive analyses to reduce fetal risk during the first trimester of pregnancy. The mechanisms by which ASM are teratogens are still under study and scientists in the field, propose different hypotheses. One of them, which will be addressed in this review, corresponds to the potential alteration of ASM on ion channels and proteins involved in relevant signaling and cellular responses (i.e., migration, differentiation) during embryonic development. The actual information related to the action of ASM and its possible targets it is poorly understood. In this review, we will focus on describing the eventual presence of some ion channels and synaptic proteins of the neurotransmitter signaling pathways present during early neural development, which could potentially interacting as targets of ASM. This information leads to elucidate whether these drugs would have the ability to affect critical signaling during periods of neural development that in turn could explain the fetal malformations observed by the use of ASM during pregnancy.
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Affiliation(s)
- Patricio A. Castro
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
- *Correspondence: Patricio A. Castro,
| | - Ingrid Pinto-Borguero
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E. Yévenes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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19
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Maillard P, Baer S, Schaefer É, Desnous B, Villeneuve N, Lépine A, Fabre A, Lacoste C, El Chehadeh S, Piton A, Porter LF, Perriard C, Wardé MA, Spitz M, Laugel V, Lesca G, Putoux A, Ville D, Mignot C, Héron D, Nabbout R, Barcia G, Rio M, Roubertie A, Meyer P, Paquis‐Flucklinger V, Patat O, Lefranc J, Gerard M, de Bellescize J, Villard L, De Saint Martin A, Milh M. Molecular and clinical descriptions of patients with GABA A receptor gene variants (GABRA1, GABRB2, GABRB3, GABRG2): A cohort study, review of literature, and genotype-phenotype correlation. Epilepsia 2022; 63:2519-2533. [PMID: 35718920 PMCID: PMC9804453 DOI: 10.1111/epi.17336] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/16/2022] [Accepted: 06/16/2022] [Indexed: 01/05/2023]
Abstract
OBJECTIVE γ-Aminobutyric acid (GABA)A -receptor subunit variants have recently been associated with neurodevelopmental disorders and/or epilepsy. The phenotype linked with each gene is becoming better known. Because of the common molecular structure and physiological role of these phenotypes, it seemed interesting to describe a putative phenotype associated with GABAA -receptor-related disorders as a whole and seek possible genotype-phenotype correlations. METHODS We collected clinical, electrophysiological, therapeutic, and molecular data from patients with GABAA -receptor subunit variants (GABRA1, GABRB2, GABRB3, and GABRG2) through a national French collaboration using the EPIGENE network and compared these data to the one already described in the literature. RESULTS We gathered the reported patients in three epileptic phenotypes: 15 patients with fever-related epilepsy (40%), 11 with early developmental epileptic encephalopathy (30%), 10 with generalized epilepsy spectrum (27%), and 1 patient without seizures (3%). We did not find a specific phenotype for any gene, but we showed that the location of variants on the transmembrane (TM) segment was associated with a more severe phenotype, irrespective of the GABAA -receptor subunit gene, whereas N-terminal variants seemed to be related to milder phenotypes. SIGNIFICANCE GABAA -receptor subunit variants are associated with highly variable phenotypes despite their molecular and physiological proximity. None of the genes described here was associated with a specific phenotype. On the other hand, it appears that the location of the variant on the protein may be a marker of severity. Variant location may have important weight in the development of targeted therapeutics.
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Affiliation(s)
- Pierre‐Yves Maillard
- Department of Medical GeneticsIGMA, Hôpitaux Universitaires de StrasbourgStrasbourgFrance,Present address:
Institut Jérome LejeuneParisFrance
| | - Sarah Baer
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance,Institute for Genetics and Molecular and Cellular Biology (IGBMC), University of Strasbourg, CNRS UMR7104, INSERM U1258IllkirchFrance
| | - Élise Schaefer
- Department of Medical GeneticsIGMA, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Béatrice Desnous
- Department of Pediatric NeurologyAP‐HM, La Timone Children's HospitalMarseilleFrance
| | - Nathalie Villeneuve
- Department of Pediatric NeurologyAP‐HM, La Timone Children's HospitalMarseilleFrance
| | - Anne Lépine
- Department of Pediatric NeurologyAP‐HM, La Timone Children's HospitalMarseilleFrance
| | - Alexandre Fabre
- Pediatric Multidisciplinary UnitAP‐HM, Timone EnfantMarseilleFrance,Aix‐Marseille University, INSERM, GMGFMarseilleFrance
| | - Caroline Lacoste
- Department of Medical GeneticsLa Timone Children's HospitalMarseilleFrance
| | - Salima El Chehadeh
- Department of Medical GeneticsIGMA, Hôpitaux Universitaires de StrasbourgStrasbourgFrance,Institute for Genetics and Molecular and Cellular Biology (IGBMC), University of Strasbourg, CNRS UMR7104, INSERM U1258IllkirchFrance
| | - Amélie Piton
- Institute for Genetics and Molecular and Cellular Biology (IGBMC), University of Strasbourg, CNRS UMR7104, INSERM U1258IllkirchFrance,Laboratory of Genetic DiagnosisInstitut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Louise Frances Porter
- Department of Medical GeneticsInstitut de Génétique Médicale d'Alsace, Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO)StrasbourgFrance
| | - Caroline Perriard
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Marie‐Thérèse Abi Wardé
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Marie‐Aude Spitz
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Vincent Laugel
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance
| | - Gaëtan Lesca
- Department of GeneticsHospices Civils de LyonBronFrance
| | - Audrey Putoux
- Department of GeneticsHospices Civils de LyonBronFrance
| | - Dorothée Ville
- Pediatric Neurology Department and Reference Center of Rare EpilepsiesMother Child Women's Hospital, Lyon University HospitalLyonFrance
| | - Cyril Mignot
- Department of GeneticsGroupe Hospitalier Pitié‐Salpêtrière and Hôpital Armand Trousseau, APHP‐Sorbonne UniversitéParisFrance,Centre de Référence Déficiences Intellectuelles de Causes RaresParisFrance
| | - Delphine Héron
- Department of GeneticsGroupe Hospitalier Pitié‐Salpêtrière and Hôpital Armand Trousseau, APHP‐Sorbonne UniversitéParisFrance,Centre de Référence Déficiences Intellectuelles de Causes RaresParisFrance
| | - Rima Nabbout
- Department of Pediatric NeurologyReference Centre for Rare Epilepsies, Necker Enfants Malades University Hospital, APHP, Université de ParisParisFrance
| | - Giulia Barcia
- Department of Medical GeneticsNecker‐Enfants Malades Hospital, Université de ParisParisFrance
| | - Marlène Rio
- Department of Medical GeneticsNecker‐Enfants Malades Hospital, Université de ParisParisFrance
| | - Agathe Roubertie
- Pediatric Neurology DepartmentINM, INSERM, CHU Montpellier, University of MontpellierMontpellierFrance
| | - Pierre Meyer
- Pediatric Neurology DepartmentINM, INSERM, CHU Montpellier, University of MontpellierMontpellierFrance
| | | | - Olivier Patat
- Department of Medical GeneticsCHU Toulouse PurpanToulouseFrance
| | | | - Marion Gerard
- Department of Medical GeneticsCentre Hospitalier Universitaire de CaenCaenFrance
| | | | - Julietta de Bellescize
- Paediatric Clinical Epileptology and Functional Neurology DepartmentReference Center of Rare Epilepsies, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL)LyonFrance
| | - Laurent Villard
- Pediatric Multidisciplinary UnitAP‐HM, Timone EnfantMarseilleFrance,Faculté de Médecine TimoneAix Marseille Univ, INSERM, MMG, U1251, ERN EpicareMarseilleFrance
| | - Anne De Saint Martin
- Department of NeuropediatricsERN EpiCare, Hôpitaux Universitaires de StrasbourgStrasbourgFrance,Institute for Genetics and Molecular and Cellular Biology (IGBMC), University of Strasbourg, CNRS UMR7104, INSERM U1258IllkirchFrance
| | - Mathieu Milh
- Department of Pediatric NeurologyAP‐HM, La Timone Children's HospitalMarseilleFrance,Faculté de Médecine TimoneAix Marseille Univ, INSERM, MMG, U1251, ERN EpicareMarseilleFrance
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20
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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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21
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Huenerfauth EI, Bien CG, Bien C, Volk HA, Meyerhoff N. Case Report: Anti-GABAA Receptor Encephalitis in a Dog. Front Vet Sci 2022; 9:886711. [PMID: 35812851 PMCID: PMC9262380 DOI: 10.3389/fvets.2022.886711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/25/2022] [Indexed: 01/21/2023] Open
Abstract
Autoantibodies against neurotransmitter receptors detected in cerebrospinal fluid (CSF) and serum are increasingly recognized in people with human autoimmune encephalitis causing severe neurological deficits, such as seizures and behavioral abnormalities. This case report describes the first encephalitis associated with antibodies against the γ-aminobutyric acid-A receptor (GABAAR) in a dog. A young male intact Cavalier King Charles Spaniel was presented with recent onset of initial multiple generalized tonic-clonic seizures progressing into a status epilepticus. Interictally, he showed alternating stupor and hyperexcitability, ataxia, pleurothotonus and circling behavior to the left side. Magnetic resonance imaging (MRI) of the brain showed breed-specific anatomical abnormalities. Standard CSF analysis was unremarkable. Despite treatment with multiple antiseizure medications (ASMs) seizures and behavior abnormalities sustained. Immunotherapy with dexamethasone was started on the fifth day after disease manifestation. This led to rapid improvement of clinical signs. An extensive antibody search in CSF and serum demonstrated a neuropil staining pattern on a tissue-based assay compatible with GABAAR antibodies. The diagnosis was confirmed by binding of serum and CSF antibodies to GABAAR transfected Human Embryonic Kidney cells. The serum titer was 1:320, the CSF titer 1:2. At the control visit 4.5 weeks after start of immunotherapy, the dog was clinically normal. The GABAAR antibody titer in serum had strongly decreased. The antibodies were no longer detectable in CSF. Based on clinical presentation and testing for GABAAR binding antibodies, this describes the first veterinary patient with an anti-GABAAR encephalitis with a good outcome following ASM and corticosteroid treatment.
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Affiliation(s)
- Enrice I. Huenerfauth
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
- *Correspondence: Enrice I. Huenerfauth
| | | | | | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
| | - Nina Meyerhoff
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
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22
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Zachlod D, Bludau S, Cichon S, Palomero-Gallagher N, Amunts K. Combined analysis of cytoarchitectonic, molecular and transcriptomic patterns reveal differences in brain organization across human functional brain systems. Neuroimage 2022; 257:119286. [PMID: 35597401 DOI: 10.1016/j.neuroimage.2022.119286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/22/2022] [Accepted: 05/05/2022] [Indexed: 01/14/2023] Open
Abstract
Brain areas show specific cellular, molecular, and gene expression patterns that are linked to function, but their precise relationships are largely unknown. To unravel these structure-function relationships, a combined analysis of 53 neurotransmitter receptor genes, receptor densities of six transmitter systems and cytoarchitectonic data of the auditory, somatosensory, visual, motor systems was conducted. Besides covariation of areal gene expression with receptor density, the study reveals specific gene expression patterns in functional systems, which are most prominent for the inhibitory GABAA and excitatory glutamatergic NMDA receptors. Furthermore, gene expression-receptor relationships changed in a systematic manner according to information flow from primary to higher associative areas. The findings shed new light on the relationship of anatomical, functional, and molecular and transcriptomic principles of cortical segregation towards a more comprehensive understanding of human brain organization.
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Affiliation(s)
- Daniel Zachlod
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.
| | - Sebastian Bludau
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Sven Cichon
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Medical Genetics and Pathology, University Hospital Basel, Basel, Switzerland
| | - Nicola Palomero-Gallagher
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; C. & O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical Faculty, RWTH Aachen, and JARA - Translational Brain Medicine, Aachen, Germany
| | - Katrin Amunts
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; C. & O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
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23
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Singh K, Kumar P, Bhatia R, Mehta V, Kumar B, Akhtar MJ. Nipecotic acid as potential lead molecule for the development of GABA uptake inhibitors; structural insights and design strategies. Eur J Med Chem 2022; 234:114269. [DOI: 10.1016/j.ejmech.2022.114269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/05/2022] [Accepted: 03/05/2022] [Indexed: 11/04/2022]
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24
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Koko M, Motelow JE, Stanley KE, Bobbili DR, Dhindsa RS, May P. Association of ultra-rare coding variants with genetic generalized epilepsy: A case-control whole exome sequencing study. Epilepsia 2022; 63:723-735. [PMID: 35032048 PMCID: PMC8891088 DOI: 10.1111/epi.17166] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/29/2021] [Accepted: 12/29/2021] [Indexed: 01/18/2023]
Abstract
OBJECTIVE We aimed to identify genes associated with genetic generalized epilepsy (GGE) by combining large cohorts enriched with individuals with a positive family history. Secondarily, we set out to compare the association of genes independently with familial and sporadic GGE. METHODS We performed a case-control whole exome sequencing study in unrelated individuals of European descent diagnosed with GGE (previously recruited and sequenced through multiple international collaborations) and ancestry-matched controls. The association of ultra-rare variants (URVs; in 18 834 protein-coding genes) with epilepsy was examined in 1928 individuals with GGE (vs. 8578 controls), then separately in 945 individuals with familial GGE (vs. 8626 controls), and finally in 1005 individuals with sporadic GGE (vs. 8621 controls). We additionally examined the association of URVs with familial and sporadic GGE in two gene sets important for inhibitory signaling (19 genes encoding γ-aminobutyric acid type A [GABAA ] receptors, 113 genes representing the GABAergic pathway). RESULTS GABRG2 was associated with GGE (p = 1.8 × 10-5 ), approaching study-wide significance in familial GGE (p = 3.0 × 10-6 ), whereas no gene approached a significant association with sporadic GGE. Deleterious URVs in the most intolerant subgenic regions in genes encoding GABAA receptors were associated with familial GGE (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 1.9-7.8, false discovery rate [FDR]-adjusted p = .0024), whereas their association with sporadic GGE had marginally lower odds (OR = 3.1, 95% CI = 1.3-6.7, FDR-adjusted p = .022). URVs in GABAergic pathway genes were associated with familial GGE (OR = 1.8, 95% CI = 1.3-2.5, FDR-adjusted p = .0024) but not with sporadic GGE (OR = 1.3, 95% CI = .9-1.9, FDR-adjusted p = .19). SIGNIFICANCE URVs in GABRG2 are likely an important risk factor for familial GGE. The association of gene sets of GABAergic signaling with familial GGE is more prominent than with sporadic GGE.
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Affiliation(s)
- Mahmoud Koko
- Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Joshua E. Motelow
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Kate E. Stanley
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Dheeraj R. Bobbili
- Luxembourg Centre for Systems Biomedicine, University Luxembourg, 4367 Belvaux, Luxembourg
| | - Ryan S. Dhindsa
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, University Luxembourg, 4367 Belvaux, Luxembourg
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25
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Genetic generalized epilepsies in adults - challenging assumptions and dogmas. Nat Rev Neurol 2022; 18:71-83. [PMID: 34837042 DOI: 10.1038/s41582-021-00583-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 01/16/2023]
Abstract
Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.
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26
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Dell'Isola GB, Vinti V, Fattorusso A, Tascini G, Mencaroni E, Di Cara G, Striano P, Verrotti A. The Broad Clinical Spectrum of Epilepsies Associated With Protocadherin 19 Gene Mutation. Front Neurol 2022; 12:780053. [PMID: 35111125 PMCID: PMC8801579 DOI: 10.3389/fneur.2021.780053] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Protocadherin 19 (PCDH19) gene is one of the most common genes involved in epilepsy syndromes. According to literature data PCDH19 is among the 6 genes most involved in genetic epilepsies. PCDH19 is located on chromosome Xq22.1 and is involved in neuronal connections and signal transduction. The most frequent clinical expression of PCDH19 mutation is epilepsy and mental retardation limited to female (EFMR) characterized by epileptic and non-epileptic symptoms affecting mainly females. However, the phenotypic spectrum of these mutations is considerably variable from genetic epilepsy with febrile seizure plus to epileptic encephalopathies. The peculiar exclusive involvement of females seems to be caused by a cellular interference in heterozygosity, however, affected mosaic-males have been reported. Seizure types range from focal seizure to generalized tonic-clonic, tonic, atonic, absences, and myoclonic jerks. Treatment of PCDH19-related epilepsy is limited by drug resistance and by the absence of specific treatment indications. However, seizures become less severe with adolescence and some patients may even become seizure-free. Non-epileptic symptoms represent the main disabilities of adult patients with PCDH19 mutation. This review aims to analyze the highly variable phenotypic expression of PCDH19 gene mutation associated with epilepsy.
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Affiliation(s)
| | - Valerio Vinti
- Department of Pediatrics, University of Perugia, Perugia, Italy
| | | | - Giorgia Tascini
- Department of Pediatrics, University of Perugia, Perugia, Italy
| | | | | | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) “G. Gaslini” Institute, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
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27
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Skotte L, Fadista J, Bybjerg-Grauholm J, Appadurai V, Hildebrand MS, Hansen TF, Banasik K, Grove J, Albiñana C, Geller F, Bjurström CF, Vilhjálmsson BJ, Coleman M, Damiano JA, Burgess R, Scheffer IE, Pedersen OBV, Erikstrup C, Westergaard D, Nielsen KR, Sørensen E, Bruun MT, Liu X, Hjalgrim H, Pers TH, Mortensen PB, Mors O, Nordentoft M, Dreier JW, Børglum AD, Christensen J, Hougaard DM, Buil A, Hviid A, Melbye M, Ullum H, Berkovic SF, Werge T, Feenstra B. Genome-wide association study of febrile seizures implicates fever response and neuronal excitability genes. Brain 2022; 145:555-568. [PMID: 35022648 PMCID: PMC9128543 DOI: 10.1093/brain/awab260] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/09/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022] Open
Abstract
Febrile seizures represent the most common type of pathological brain activity in
young children and are influenced by genetic, environmental and developmental
factors. In a minority of cases, febrile seizures precede later development of
epilepsy. We conducted a genome-wide association study of febrile seizures in 7635 cases
and 83 966 controls identifying and replicating seven new loci, all with
P < 5 × 10−10. Variants at two loci were functionally related to altered expression of the fever
response genes PTGER3 and IL10, and four other
loci harboured genes (BSN, ERC2,
GABRG2, HERC1) influencing neuronal
excitability by regulating neurotransmitter release and binding, vesicular
transport or membrane trafficking at the synapse. Four previously reported loci
(SCN1A, SCN2A, ANO3 and
12q21.33) were all confirmed. Collectively, the seven novel and four previously
reported loci explained 2.8% of the variance in liability to febrile
seizures, and the single nucleotide polymorphism heritability based on all
common autosomal single nucleotide polymorphisms was 10.8%.
GABRG2, SCN1A and SCN2A
are well-established epilepsy genes and, overall, we found positive genetic
correlations with epilepsies (rg = 0.39,
P = 1.68 × 10−4). Further,
we found that higher polygenic risk scores for febrile seizures were associated
with epilepsy and with history of hospital admission for febrile seizures.
Finally, we found that polygenic risk of febrile seizures was lower in febrile
seizure patients with neuropsychiatric disease compared to febrile seizure
patients in a general population sample. In conclusion, this largest genetic investigation of febrile seizures to date
implicates central fever response genes as well as genes affecting neuronal
excitability, including several known epilepsy genes. Further functional and
genetic studies based on these findings will provide important insights into the
complex pathophysiological processes of seizures with and without fever.
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Affiliation(s)
- Line Skotte
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - João Fadista
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
- Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Jonas Bybjerg-Grauholm
- Danish Centre for Neonatal Screening, Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
| | - Vivek Appadurai
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Mental Health Center Sct. Hans, Mental Health Services, Capital Region Denmark, Roskilde, Denmark
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
- Murdoch Children’s Research Institute, Parkville, Victoria, Australia
| | - Thomas F Hansen
- Danish Headache Center, Department of Neurology, Rigshospitalet-Glostrup, Denmark
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Karina Banasik
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Grove
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- Department of Biomedicine–Human Genetics, Aarhus University, Aarhus, Denmark
- Bioinformatics Research Centre, Aarhus University, Aarhus, Denmark
| | - Clara Albiñana
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Frank Geller
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Carmen F Bjurström
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Bjarni J Vilhjálmsson
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Matthew Coleman
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
- Murdoch Children’s Research Institute, Parkville, Victoria, Australia
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
| | - Rosemary Burgess
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
- Department of Paediatrics, Royal Children's Hospital, The University of Melbourne, Flemington, Victoria, Australia
- The Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia
| | | | - Christian Erikstrup
- Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark
| | - David Westergaard
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Kaspar René Nielsen
- Department of Clinical Immunology, Aalborg University Hospital North, Aalborg, Denmark
| | - Erik Sørensen
- Department of Clinical Immunology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Mie Topholm Bruun
- Department of Clinical Immunology, Odense University Hospital, Odense, Denmark
| | - Xueping Liu
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Henrik Hjalgrim
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
- Department of Haematology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Preben Bo Mortensen
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Ole Mors
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - Merete Nordentoft
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Mental Health Center Copenhagen, Mental Health Services in the Capital Region of Denmark, Copenhagen, Denmark
| | - Julie W Dreier
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Anders D Børglum
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- Department of Biomedicine–Human Genetics, Aarhus University, Aarhus, Denmark
| | - Jakob Christensen
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - David M Hougaard
- Danish Centre for Neonatal Screening, Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
| | - Alfonso Buil
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Mental Health Center Sct. Hans, Mental Health Services, Capital Region Denmark, Roskilde, Denmark
| | - Anders Hviid
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
- Department of Drug Design and Pharmacology, Pharmacovigilance Research Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mads Melbye
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Henrik Ullum
- Department of Clinical Immunology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Statens Serum Institut, Copenhagen, Denmark
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Victoria, Australia
| | - Thomas Werge
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Mental Health Center Sct. Hans, Mental Health Services, Capital Region Denmark, Roskilde, Denmark
| | - Bjarke Feenstra
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
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28
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GABRA1 and GABRA6 gene mutations in idiopathic generalized epilepsy patients. Seizure 2021; 93:88-94. [PMID: 34740144 DOI: 10.1016/j.seizure.2021.10.013] [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: 06/19/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 12/25/2022] Open
Abstract
The GABA receptor is an important epilepsy-associated candidate gene, and has always been a focus in etiology and in the treatment of epilepsy. This study explores the genetic association between GABA receptor gene polymorphisms and epilepsy in a cohort of the Pakistani population. A case-control study was conducted on 150 patients with idiopathic generalized epilepsy (IGE) and 150 controls. Blood samples were collected, and genomic DNA was extracted and amplified using polymerase chain reaction (PCR). The amplified products were subsequently genotyped by Sanger sequencing and the results were analyzed using the chi-square test. Among the five mutational sites observed, two GABRA1 (rs2279020 and novel c.1016_1017insT) and two GABRA6 (rs3219151 and novel c.1344C>G) were found to be significantly associated with IGE. Amino acid alignment showed that a novel insertion mutation, c.1016_1017insT, in GABRA1 disrupted the reading frame and was possibly damaging, whereas c.1344C>G in GABRA6 was responsible for a synonymous mutation. Therefore, both the GABA receptor genes may play critical roles in the development of epilepsy in Pakistani patients.
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Wu A, Yu Q, Lu H, Lou Z, Zhao Y, Luo T, Fu Z, Jin Y. Developmental toxicity of procymidone to larval zebrafish based on physiological and transcriptomic analysis. Comp Biochem Physiol C Toxicol Pharmacol 2021; 248:109081. [PMID: 34004283 DOI: 10.1016/j.cbpc.2021.109081] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/20/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022]
Abstract
As a broad-spectrum with low toxicity, procymidone (PCM), is widely used in agriculture and frequently observed in aquatic system, which may cause some impacts on aquatic organisms. Here, to determine the developmental toxicity of PCM, embryonic and larval zebrafish were exposed to PCM at 0, 1, 10, 100 μg/L in dehydrogenated natural water containing 0.01% acetone for 7 days. The results showed that high concentration of PCM could cause the pericardial edema and increase the heart rates in larval zebrafish, suggesting that PCM had developmental toxicity to zebrafish. We also observed that PCM exposure not only changed the physiological parameters including TBA, GLU and pyruvic acid, but also changed the transcriptional levels of glycolipid metabolism related genes. In addition, after transcriptomics analysis, a total of 1065 differentially expressed genes, including 456 up-regulated genes and 609 down-regulated genes, changed significantly in 100 μg/L PCM treated larval zebrafish. Interestingly, after GO (Gene Ontology) analysis, the different expression genes (DEGs) were mainly enriched to the three different biology processes including GABA-nervous, lipid Metabolism and response to drug. We also observed that the levels of GABA receptor related genes including gabrg2, gabbr1α, gabbr1 and gabra6α were inhibited by PCM exposure. Interestingly, the swimming distance of larval zebrafish had the tendency to decrease after PCM exposure, indicating that the nervous system was affected by PCM. Taken together, the results confirmed that the fungicide PCM could cause developmental toxicity by influencing the lipid metabolism and GABA mediated nervous system and behavior in larval zebrafish. We believed that the results could provide an important data for the influence of PCM on aquatic animals.
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Affiliation(s)
- Anyi Wu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Qianxuan Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Huahui Lu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Ze Lou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yao Zhao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Ting Luo
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yuanxiang Jin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China.
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Belelli D, Hales TG, Lambert JJ, Luscher B, Olsen R, Peters JA, Rudolph U, Sieghart W. GABA A receptors in GtoPdb v.2021.3. IUPHAR/BPS GUIDE TO PHARMACOLOGY CITE 2021; 2021. [PMID: 35005623 DOI: 10.2218/gtopdb/f72/2021.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The GABAA receptor is a ligand-gated ion channel of the Cys-loop family that includes the nicotinic acetylcholine, 5-HT3 and strychnine-sensitive glycine receptors. GABAA receptor-mediated inhibition within the CNS occurs by fast synaptic transmission, sustained tonic inhibition and temporally intermediate events that have been termed 'GABAA, slow' [45]. GABAA receptors exist as pentamers of 4TM subunits that form an intrinsic anion selective channel. Sequences of six α, three β, three γ, one δ, three ρ, one ε, one π and one θ GABAA receptor subunits have been reported in mammals [278, 235, 236, 283]. The π-subunit is restricted to reproductive tissue. Alternatively spliced versions of many subunits exist (e.g. α4- and α6- (both not functional) α5-, β2-, β3- and γ2), along with RNA editing of the α3 subunit [71]. The three ρ-subunits, (ρ1-3) function as either homo- or hetero-oligomeric assemblies [359, 50]. Receptors formed from ρ-subunits, because of their distinctive pharmacology that includes insensitivity to bicuculline, benzodiazepines and barbiturates, have sometimes been termed GABAC receptors [359], but they are classified as GABA A receptors by NC-IUPHAR on the basis of structural and functional criteria [16, 235, 236]. Many GABAA receptor subtypes contain α-, β- and γ-subunits with the likely stoichiometry 2α.2β.1γ [168, 235]. It is thought that the majority of GABAA receptors harbour a single type of α- and β - subunit variant. The α1β2γ2 hetero-oligomer constitutes the largest population of GABAA receptors in the CNS, followed by the α2β3γ2 and α3β3γ2 isoforms. Receptors that incorporate the α4- α5-or α 6-subunit, or the β1-, γ1-, γ3-, δ-, ε- and θ-subunits, are less numerous, but they may nonetheless serve important functions. For example, extrasynaptically located receptors that contain α6- and δ-subunits in cerebellar granule cells, or an α4- and δ-subunit in dentate gyrus granule cells and thalamic neurones, mediate a tonic current that is important for neuronal excitability in response to ambient concentrations of GABA [209, 272, 83, 19, 288]. GABA binding occurs at the β+/α- subunit interface and the homologous γ+/α- subunits interface creates the benzodiazepine site. A second site for benzodiazepine binding has recently been postulated to occur at the α+/β- interface ([254]; reviewed by [282]). The particular α-and γ-subunit isoforms exhibit marked effects on recognition and/or efficacy at the benzodiazepine site. Thus, receptors incorporating either α4- or α6-subunits are not recognised by 'classical' benzodiazepines, such as flunitrazepam (but see [356]). The trafficking, cell surface expression, internalisation and function of GABAA receptors and their subunits are discussed in detail in several recent reviews [52, 140, 188, 316] but one point worthy of note is that receptors incorporating the γ2 subunit (except when associated with α5) cluster at the postsynaptic membrane (but may distribute dynamically between synaptic and extrasynaptic locations), whereas as those incorporating the δ subunit appear to be exclusively extrasynaptic. NC-IUPHAR [16, 235, 3, 2] class the GABAA receptors according to their subunit structure, pharmacology and receptor function. Currently, eleven native GABAA receptors are classed as conclusively identified (i.e., α1β2γ2, α1βγ2, α3βγ2, α4βγ2, α4β2δ, α4β3δ, α5βγ2, α6βγ2, α6β2δ, α6β3δ and ρ) with further receptor isoforms occurring with high probability, or only tentatively [235, 236]. It is beyond the scope of this Guide to discuss the pharmacology of individual GABAA receptor isoforms in detail; such information can be gleaned in the reviews [16, 95, 168, 173, 143, 278, 216, 235, 236] and [9, 10]. Agents that discriminate between α-subunit isoforms are noted in the table and additional agents that demonstrate selectivity between receptor isoforms, for example via β-subunit selectivity, are indicated in the text below. The distinctive agonist and antagonist pharmacology of ρ receptors is summarised in the table and additional aspects are reviewed in [359, 50, 145, 223]. Several high-resolution cryo-electron microscopy structures have been described in which the full-length human α1β3γ2L GABAA receptor in lipid nanodiscs is bound to the channel-blocker picrotoxin, the competitive antagonist bicuculline, the agonist GABA (γ-aminobutyric acid), and the classical benzodiazepines alprazolam and diazepam [198].
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Zaganas I, Vorgia P, Spilioti M, Mathioudakis L, Raissaki M, Ilia S, Giorgi M, Skoula I, Chinitrakis G, Michaelidou K, Paraskevoulakos E, Grafakou O, Kariniotaki C, Psyllou T, Zafeiris S, Tzardi M, Briassoulis G, Dinopoulos A, Mitsias P, Evangeliou A. Genetic cause of epilepsy in a Greek cohort of children and young adults with heterogeneous epilepsy syndromes. Epilepsy Behav Rep 2021; 16:100477. [PMID: 34568804 PMCID: PMC8449081 DOI: 10.1016/j.ebr.2021.100477] [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] [Received: 04/27/2021] [Revised: 08/17/2021] [Accepted: 08/23/2021] [Indexed: 12/01/2022] Open
Abstract
We describe a cohort of 10 unrelated Greek patients (4 females, 6 males; median age 6.5 years, range 2-18 years) with heterogeneous epilepsy syndromes with a genetic basis. In these patients, causative genetic variants, including two novel ones, were identified in 9 known epilepsy-related genes through whole exome sequencing. A patient with glycine encephalopathy was a compound heterozygote for the p.Arg222Cys and the p.Ser77Leu AMT variant. A patient affected with Lafora disease carried the homozygous p.Arg171His EPM2A variant. A de novo heterozygous variant in the GABRG2 gene (p.Pro282Thr) was found in one patient and a pathogenic variant in the GRIN2B gene (p.Gly820Val) in another patient. Infantile-onset lactic acidosis with seizures was associated with the p.Arg446Ter PDHX gene variant in one patient. In two additional epilepsy patients, the p.Ala1662Val and the novel non-sense p.Phe1330Ter SCN1A gene variants were found. Finally, in 3 patients we observed a novel heterozygous missense variant in SCN2A (p.Ala1874Thr), a heterozygous splice site variant in SLC2A1 (c.517-2A>G), as a cause of Glut1 deficiency syndrome, and a pathogenic variant in STXBP1 (p.Arg292Leu), respectively. In half of our cases (patients with variants in the GRIN2B, SCN1A, SCN2A and SLC2A1 genes), a genetic cause with potential management implications was identified.
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Affiliation(s)
- Ioannis Zaganas
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
- Neurology Department, University Hospital of Heraklion, Crete, Greece
| | - Pelagia Vorgia
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Martha Spilioti
- AHEPA General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Lambros Mathioudakis
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Maria Raissaki
- Department of Radiology, University Hospital of Heraklion, Crete, Greece
| | - Stavroula Ilia
- Pediatric Intensive Care Unit, University Hospital of Heraklion, Crete, Greece
| | | | - Irene Skoula
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | | | - Kleita Michaelidou
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | | | - Olga Grafakou
- Pediatric Department, Venizelion General Hospital, Heraklio, Crete, Greece
| | - Chariklia Kariniotaki
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Thekla Psyllou
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Spiros Zafeiris
- Neurology Department, University Hospital of Heraklion, Crete, Greece
| | - Maria Tzardi
- Pathology Department, Medical School, University of Crete, Greece
| | - George Briassoulis
- Pediatric Intensive Care Unit, University Hospital of Heraklion, Crete, Greece
| | | | - Panayiotis Mitsias
- Neurology Department, University Hospital of Heraklion, Crete, Greece
- Department of Neurology, Henry Ford Hospital/Wayne State University, Detroit, MI, USA
| | - Athanasios Evangeliou
- Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Neocortex- and hippocampus-specific deletion of Gabrg2 causes temperature-dependent seizures in mice. Cell Death Dis 2021; 12:553. [PMID: 34050134 PMCID: PMC8163876 DOI: 10.1038/s41419-021-03846-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/17/2021] [Indexed: 02/04/2023]
Abstract
Mutations in the GABRG2 gene encoding the γ-aminobutyric acid (GABA) A receptor gamma 2 subunit are associated with genetic epilepsy with febrile seizures plus, febrile seizures plus, febrile seizures, and other symptoms of epilepsy. However, the mechanisms underlying Gabrg2-mediated febrile seizures are poorly understood. Here, we used the Cre/loxP system to generate conditional knockout (CKO) mice with deficient Gabrg2 in the hippocampus and neocortex. Heterozygous CKO mice (Gabrg2fl/wtCre+) exhibited temperature-dependent myoclonic jerks, generalised tonic-clonic seizures, increased anxiety-like symptoms, and a predisposition to induce seizures. Cortical electroencephalography showed the hyperexcitability in response to temperature elevation in Gabrg2fl/wtCre+ mice, but not in wild-type mice. Gabrg2fl/wtCre+ mice exhibited spontaneous seizures and susceptibility to temperature-induced seizures. Loss of neurons were observed in cortical layers V-VI and hippocampus of Gabrg2fl/wtCre+ mice. Furthermore, the latency of temperature- or pentylenetetrazol-induced seizures were significantly decreased in Gabrg2fl/wtCre+ mice compared with wild-type mice. In summary, Gabrg2fl/wtCre+ mice with Gabrg2 deletion in the neocortex and hippocampus reproduce many features of febrile seizures and therefore provide a novel model to further understand this syndrome at the cellular and molecular level.
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Keute M, Wienke C, Ruhnau P, Zaehle T. Effects of transcutaneous vagus nerve stimulation (tVNS) on beta and gamma brain oscillations. Cortex 2021; 140:222-231. [PMID: 34015727 DOI: 10.1016/j.cortex.2021.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/05/2021] [Accepted: 04/12/2021] [Indexed: 12/01/2022]
Abstract
Physiological and behavioral effects induced through transcutaneous vagus nerve stimulation (tVNS) are under scrutiny in a growing number of studies, yet its mechanisms of action remain poorly understood. One candidate mechanism is a modulation of γ-aminobutyric acid (GABA) transmission through tVNS. Two recent behavioral studies suggest that such a GABAergic effect might occur in a lateralized fashion, i.e., the GABA modulation might be stronger in the left than in the right brain hemisphere after tVNS applied to the left ear. Using magnetoencephalography (MEG), we tested for GABA-associated modulations in resting and event-related brain oscillations and for a lateralization of those effects in a sample of 41 healthy young adults. Our data provide substantial evidence against all hypotheses, i.e., we neither find effects of tVNS on oscillatory power nor a lateralization of effects.
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Affiliation(s)
- Marius Keute
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Institute for Neuromodulation and Neurotechnology, University of Tübingen, Tübingen, Germany.
| | - Christian Wienke
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
| | - Philipp Ruhnau
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
| | - Tino Zaehle
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
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Excitatory/Inhibitory Synaptic Ratios in Polymicrogyria and Down Syndrome Help Explain Epileptogenesis in Malformations. Pediatr Neurol 2021; 116:41-54. [PMID: 33450624 DOI: 10.1016/j.pediatrneurol.2020.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND The ratio between excitatory (glutamatergic) and inhibitory (GABAergic) inputs into maturing individual cortical neurons influences their epileptic potential. Structural factors during development that alter synaptic inputs can be demonstrated neuropathologically. Increased mitochondrial activity identifies neurons with excessive discharge rates. METHODS This study focuses on the neuropathological examinaion of surgical resections for epilepsy and at autopsy, in fetuses, infants, and children, using immunocytochemical markers, and electron microscopy in selected cases. Polymicrogyria and Down syndrome are highlighted. RESULTS Factors influencing afferent synaptic ratios include the following: (1) synaptic short-circuitry in fused molecular zones of adjacent gyri (polymicrogyria); (2) impaired development of dendritic spines decreasing excitation (Down syndrome); (3) extracellular keratan sulfate proteoglycan binding to somatic membranes but not dendritic spines may be focally diminished (cerebral atrophy, schizencephaly, lissencephaly, polymicrogyria) or augmented, ensheathing individual axons (holoprosencephaly), or acting as a barrier to axonal passage in the U-fiber layer. If keratan is diminished, glutamate receptors on the neuronal soma enable ectopic axosomatic excitatory synapses to form; (4) dysplastic, megalocytic neurons and balloon cells in mammalian target of rapamycin disorders; (5) satellitosis of glial cells displacing axosomatic synapses; (6) peri-neuronal inflammation (tuberous sclerosis) and heat-shock proteins. CONCLUSIONS Synaptic ratio of excitatory/inhibitory afferents is a major fundamental basis of epileptogenesis at the neuronal level. Neuropathology can demonstrate subcellular changes that help explain either epilepsy or lack of seizures in immature brains. Synaptic ratios in malformations influence postnatal epileptogenesis. Single neurons can be hypermetabolic and potentially epileptogenic.
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Qu S, Zhou C, Howe R, Shen W, Huang X, Catron M, Hu N, Macdonald RL. The K328M substitution in the human GABA A receptor gamma2 subunit causes GEFS+ and premature sudden death in knock-in mice. Neurobiol Dis 2021; 152:105296. [PMID: 33582225 PMCID: PMC8243844 DOI: 10.1016/j.nbd.2021.105296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 01/19/2021] [Accepted: 02/08/2021] [Indexed: 01/03/2023] Open
Affiliation(s)
- Shimian Qu
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Chengwen Zhou
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Rachel Howe
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Wangzhen Shen
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Xuan Huang
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Mackenzie Catron
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Ningning Hu
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America.
| | - Robert L Macdonald
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232, United States of America; Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, United States of America; Pharmacology, Vanderbilt University, Nashville, TN 37232, United States of America.
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Castellano D, Shepard RD, Lu W. Looking for Novelty in an "Old" Receptor: Recent Advances Toward Our Understanding of GABA ARs and Their Implications in Receptor Pharmacology. Front Neurosci 2021; 14:616298. [PMID: 33519367 PMCID: PMC7841293 DOI: 10.3389/fnins.2020.616298] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022] Open
Abstract
Diverse populations of GABAA receptors (GABAARs) throughout the brain mediate fast inhibitory transmission and are modulated by various endogenous ligands and therapeutic drugs. Deficits in GABAAR signaling underlie the pathophysiology behind neurological and neuropsychiatric disorders such as epilepsy, anxiety, and depression. Pharmacological intervention for these disorders relies on several drug classes that target GABAARs, such as benzodiazepines and more recently neurosteroids. It has been widely demonstrated that subunit composition and receptor stoichiometry impact the biophysical and pharmacological properties of GABAARs. However, current GABAAR-targeting drugs have limited subunit selectivity and produce their therapeutic effects concomitantly with undesired side effects. Therefore, there is still a need to develop more selective GABAAR pharmaceuticals, as well as evaluate the potential for developing next-generation drugs that can target accessory proteins associated with native GABAARs. In this review, we briefly discuss the effects of benzodiazepines and neurosteroids on GABAARs, their use as therapeutics, and some of the pitfalls associated with their adverse side effects. We also discuss recent advances toward understanding the structure, function, and pharmacology of GABAARs with a focus on benzodiazepines and neurosteroids, as well as newly identified transmembrane proteins that modulate GABAARs.
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Affiliation(s)
- David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Ryan David Shepard
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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Faraz M, Kosarmadar N, Rezaei M, Zare M, Javan M, Barkley V, Shojaei A, Mirnajafi-Zadeh J. Deep brain stimulation effects on learning, memory and glutamate and GABA A receptor subunit gene expression in kindled rats. Acta Neurobiol Exp (Wars) 2021; 81:43-57. [PMID: 33949168 DOI: 10.21307/ane-2021-006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 01/14/2021] [Indexed: 11/11/2022]
Abstract
Epileptic seizures are accompanied by learning and memory impairments. In this study, the effect of low frequency stimulation (LFS) on spatial learning and memory was assessed in kindled animals and followed for one month. Fully kindled rats received LFS at 4 times (immediately, 6 h, 24 h and 30 h following the final kindling stimulation). Applying LFS improved kindled animals' performance in the Barnes maze test. This LFS action was accompanied by a decrease in NR2B gene expression, an increase in the gene expression of the α subunit of calcineurin A and an increased NR2A/NR2B ratio in kindled animals. In addition, the gene expression of the GABAA receptor γ2 subunit increased at 2-3 h after applying LFS. The increase in NR2A/NR2B ratio was also observed 1 week after LFS. No significant changes were observed one month after LFS administration. Field potential recordings in the hippocampal CA1 area showed that kindling-induced potentiation of the field EPSP slope returned to near baseline when measured 2-3 h after applying LFS. Therefore, it may be postulated that applying LFS in kindled animals reduced the seizure-induced learning and memory impairments, albeit time-dependently. In tandem, LFS prevented kindling-induced alterations in gene expression of the described proteins, which are potentially important for synaptic transmission and/or potentiation. Moreover, a depotentiation-like phenomenon may be a possible mechanism underlying the LFS action. Epileptic seizures are accompanied by learning and memory impairments. In this study, the effect of low frequency stimulation (LFS) on spatial learning and memory was assessed in kindled animals and followed for one month. Fully kindled rats received LFS at 4 times (immediately, 6 h, 24 h and 30 h following the final kindling stimulation). Applying LFS improved kindled animals’ performance in the Barnes maze test. This LFS action was accompanied by a decrease in NR2B gene expression, an increase in the gene expression of the α subunit of calcineurin A and an increased NR2A/NR2B ratio in kindled animals. In addition, the gene expression of the GABAA receptor γ2 subunit increased at 2–3 h after applying LFS. The increase in NR2A/NR2B ratio was also observed 1 week after LFS. No significant changes were observed one month after LFS administration. Field potential recordings in the hippocampal CA1 area showed that kindling-induced potentiation of the field EPSP slope returned to near baseline when measured 2–3 h after applying LFS. Therefore, it may be postulated that applying LFS in kindled animals reduced the seizure-induced learning and memory impairments, albeit time-dependently. In tandem, LFS prevented kindling-induced alterations in gene expression of the described proteins, which are potentially important for synaptic transmission and/or potentiation. Moreover, a depotentiation-like phenomenon may be a possible mechanism underlying the LFS action.
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Affiliation(s)
- Mona Faraz
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran
| | - Nastaran Kosarmadar
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran
| | - Mahmoud Rezaei
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran
| | - Meysam Zare
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran
| | - Mohammad Javan
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran ; Institute for Brain Sciences and Cognition , Tarbiat Modares University , Tehran , Iran
| | - Victoria Barkley
- Krembil Research Institute , University Health Network , Toronto , Canada
| | - Amir Shojaei
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran ; Institute for Brain Sciences and Cognition , Tarbiat Modares University , Tehran , Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology , Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran ; Institute for Brain Sciences and Cognition , Tarbiat Modares University , Tehran , Iran
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Neural Networks in Health and Disease. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11470-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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El Achkar CM, Harrer M, Smith L, Kelly M, Iqbal S, Maljevic S, Niturad CE, Vissers LELM, Poduri A, Yang E, Lal D, Lerche H, Møller RS, Olson HE. Characterization of the GABRB2-Associated Neurodevelopmental Disorders. Ann Neurol 2020; 89:573-586. [PMID: 33325057 DOI: 10.1002/ana.25985] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVE We aimed to characterize the phenotypic spectrum and functional consequences associated with variants in the gene GABRB2, coding for the γ-aminobutyric acid type A (GABAA ) receptor subunit β2. METHODS We recruited and systematically evaluated 25 individuals with variants in GABRB2, 17 of whom are newly described and 8 previously reported with additional clinical data. Functional analysis was performed using a Xenopus laevis oocyte model system. RESULTS Our cohort of 25 individuals from 22 families with variants in GABRB2 demonstrated a range of epilepsy phenotypes from genetic generalized epilepsy to developmental and epileptic encephalopathy. Fifty-eight percent of individuals had pharmacoresistant epilepsy; response to medications targeting the GABAergic pathway was inconsistent. Developmental disability (present in 84%) ranged from mild intellectual disability to severe global disability; movement disorders (present in 44%) included choreoathetosis, dystonia, and ataxia. Disease-associated variants cluster in the extracellular N-terminus and transmembrane domains 1-3, with more severe phenotypes seen in association with variants in transmembrane domains 1 and 2 and the allosteric binding site between transmembrane domains 2 and 3. Functional analysis of 4 variants in transmembrane domains 1 or 2 (p.Ile246Thr, p.Pro252Leu, p.Ile288Ser, p.Val282Ala) revealed strongly reduced amplitudes of GABA-evoked anionic currents. INTERPRETATION GABRB2-related epilepsy ranges broadly in severity from genetic generalized epilepsy to developmental and epileptic encephalopathies. Developmental disability and movement disorder are key features. The phenotypic spectrum is comparable to other GABAA receptor-encoding genes. Phenotypic severity varies by protein domain. Experimental evidence supports loss of GABAergic inhibition as the mechanism underlying GABRB2-associated neurodevelopmental disorders. ANN NEUROL 2021;89:573-586.
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Affiliation(s)
- Christelle M El Achkar
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
| | - Merle Harrer
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lacey Smith
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA
| | - McKenna Kelly
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA.,Dartmouth Geisel School of Medicine, Hanover, NH
| | - Sumaiya Iqbal
- Center for Development of Therapeutics and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Snezana Maljevic
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Cristina E Niturad
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lisenka E L M Vissers
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Annapurna Poduri
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
| | - Edward Yang
- Department of Radiology, Boston Children's Hospital, Boston, MA
| | - Dennis Lal
- Cleveland Clinic Genomic Medicine Institute and Neurological Institute, Cleveland, OH
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Treatment, Danish Epilepsy Center Filadelfia, Dianalund, Denmark.,Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Heather E Olson
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
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Yu W, Hill SF, Xenakis JG, Pardo-Manuel de Villena F, Wagnon JL, Meisler MH. Gabra2 is a genetic modifier of Scn8a encephalopathy in the mouse. Epilepsia 2020; 61:2847-2856. [PMID: 33140451 PMCID: PMC7756374 DOI: 10.1111/epi.16741] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 12/23/2022]
Abstract
Objective SCN8A encephalopathy is a developmental epileptic encephalopathy typically caused by de novo gain‐of‐function mutations in Nav1.6. Severely affected individuals exhibit refractory seizures, developmental delay, cognitive disabilities, movement disorders, and elevated risk of sudden death. Patients with the identical SCN8A variant can differ in clinical course, suggesting a role for modifier genes in determining disease severity. The identification of genetic modifiers contributes to understanding disease pathogenesis and suggesting therapeutic interventions. Methods We generated F1 and F2 crosses between inbred mouse strains and mice carrying the human pathogenic variants SCN8A‐R1872W and SCN8A‐N1768D. Quantitative trait locus (QTL) analysis of seizure‐related phenotypes was used for chromosomal mapping of modifier loci. Results In an F2 cross between strain SJL/J and C57BL/6J mice carrying the patient mutation R1872W, we identified a major QTL on chromosome 5 containing the Gabra2 gene. Strain C57BL/6J carries a splice site mutation that reduces expression of Gabra2, encoding the α2 subunit of the aminobutyric acid type A receptor. The protective wild‐type allele of Gabra2 from strain SJL/J delays the age at seizure onset and extends life span of the Scn8a mutant mice. Additional Scn8a modifiers were observed in the F2 cross and in an F1 cross with strain C3HeB/FeJ. Significance These studies demonstrate that the SJL/J strain carries multiple modifiers with protective effects against seizures induced by gain‐of‐function mutations in Scn8a. Homozygosity for the hypomorphic variant of Gabra2 in strain C57BL/6J is associated with early seizure onset and short life span. GABRA2 is a potential therapeutic target for SCN8A encephalopathy.
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Affiliation(s)
- Wenxi Yu
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Sophie F Hill
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - James G Xenakis
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | | | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Miriam H Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
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Han JY, Lee HJ, Lee YM, Park J. Identification of Missense ADGRV1 Mutation as a Candidate Genetic Cause of Familial Febrile Seizure 4. CHILDREN (BASEL, SWITZERLAND) 2020; 7:children7090144. [PMID: 32962041 PMCID: PMC7552766 DOI: 10.3390/children7090144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/03/2023]
Abstract
Febrile seizure (FS) is related to a febrile illness (temperature > 38 °C) not caused by an infection of central nervous system, without neurologic deficits in children aged 6–60 months. The family study implied a polygenic model in the families of proband(s) with single FS, however in families with repeated FS, inheritance was matched to autosomal dominance with reduced disease penetrance. A 20 month-old girl showed recurrent FS and afebrile seizures without developmental delay or intellectual disability. The seizures disappeared after 60 months without anti-seizure medication. The 35 year-old proband’s mother also experienced five episodes of simple FS and two episodes of unprovoked seizures before 5 years old. Targeted exome sequencing was conducted along with epilepsy/seizure-associated gene-filtering to identify the candidate causative mutation. As a result, a heterozygous c.2039A>G of the ADGRV1 gene leading to a codon change of aspartic acid to glycine at the position 680 (rs547076322) was identified. This protein’s glycine residue is highly conserved, and its allele frequency is 0.00002827 in the gnomAD population database. ADGRV1 mutation may have an influential role in the occurrence of genetic epilepsies, especially those with febrile and afebrile seizures. Further investigation of ADGRV1 mutations is needed to prove that it is a significant susceptible gene for febrile and/or afebrile seizures in early childhood.
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Affiliation(s)
- Ji Yoon Han
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea;
| | - Hyun Joo Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul 06273, Korea;
| | - Young-Mock Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul 06273, Korea;
- Correspondence: (Y.-M.L.); (J.P.); Tel.: +82-2-2019-3354 (Y.-M.L.); +82-42-220-9799 (J.P.); Fax: +82-2-3261-9473 (Y.-M.L.); +82-42-220-9915 (J.P.)
| | - Joonhong Park
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Korea
- Correspondence: (Y.-M.L.); (J.P.); Tel.: +82-2-2019-3354 (Y.-M.L.); +82-42-220-9799 (J.P.); Fax: +82-2-3261-9473 (Y.-M.L.); +82-42-220-9915 (J.P.)
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Kapur M, Ganguly A, Nagy G, Adamson SI, Chuang JH, Frankel WN, Ackerman SL. Expression of the Neuronal tRNA n-Tr20 Regulates Synaptic Transmission and Seizure Susceptibility. Neuron 2020; 108:193-208.e9. [PMID: 32853550 DOI: 10.1016/j.neuron.2020.07.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/07/2020] [Accepted: 07/19/2020] [Indexed: 12/31/2022]
Abstract
The mammalian genome has hundreds of nuclear-encoded tRNAs, but the contribution of individual tRNA genes to cellular and organismal function remains unknown. Here, we demonstrate that mutations in a neuronally enriched arginine tRNA, n-Tr20, increased seizure threshold and altered synaptic transmission. n-Tr20 expression also modulated seizures caused by an epilepsy-linked mutation in Gabrg2, a gene encoding a GABAA receptor subunit. Loss of n-Tr20 altered translation initiation by activating the integrated stress response and suppressing mTOR signaling, the latter of which may contribute to altered neurotransmission in mutant mice. Deletion of a highly expressed isoleucine tRNA similarly altered these signaling pathways in the brain, suggesting that regulation of translation initiation is a conserved response to tRNA loss. Our data indicate that loss of a single member of a tRNA family results in multiple cellular phenotypes, highlighting the disease-causing potential of tRNA mutations.
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Affiliation(s)
- Mridu Kapur
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Archan Ganguly
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gabor Nagy
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Scott I Adamson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Health, Farmington, CT 06030, USA
| | - Jeffrey H Chuang
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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Gallo NB, Paul A, Van Aelst L. Shedding Light on Chandelier Cell Development, Connectivity, and Contribution to Neural Disorders. Trends Neurosci 2020; 43:565-580. [PMID: 32564887 PMCID: PMC7392791 DOI: 10.1016/j.tins.2020.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/06/2020] [Accepted: 05/07/2020] [Indexed: 02/04/2023]
Abstract
Chandelier cells (ChCs) are a unique type of GABAergic interneuron that selectively innervate the axon initial segment (AIS) of excitatory pyramidal neurons; the subcellular domain where action potentials are initiated. The proper genesis and maturation of ChCs is critical for regulating neural ensemble firing in the neocortex throughout development and adulthood. Recently, genetic and molecular studies have shed new light on the complex innerworkings of ChCs in health and disease. This review presents an overview of recent studies on the developmental origins, migratory properties, and morphology of ChCs. In addition, attention is given to newly identified molecules regulating ChC morphogenesis and connectivity as well as recent work linking ChC dysfunction to neural disorders, including schizophrenia, epilepsy, and autism spectrum disorder (ASD).
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Affiliation(s)
- Nicholas B Gallo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 11724, USA; Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Anirban Paul
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, PA, 17033, USA
| | - Linda Van Aelst
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 11724, USA.
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Fortin O, Vincelette C, Chénier S, Ghais A, Shevell MI, Simard-Tremblay E, Myers KA. Copy number variation in genetic epilepsy with febrile seizures plus. Eur J Paediatr Neurol 2020; 27:111-115. [PMID: 32595013 DOI: 10.1016/j.ejpn.2020.05.005] [Citation(s) in RCA: 3] [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: 12/30/2019] [Revised: 05/10/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022]
Abstract
AIM Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which affected individuals may have a variety of epilepsy phenotypes, the most common being febrile seizures (FS) and febrile seizures plus (FS+). We investigated the possible contribution of copy number variation to GEFS+. METHOD We searched our epilepsy research database for patients in GEFS + families who underwent chromosomal microarray analysis. We reviewed the clinical features and results of genetic testing in these families. RESULTS Of twelve families with available microarray data, four had at least one copy number variant (CNV) identified. In Family 1, the proband had a maternally-inherited 15q11.2 deletion. In Family 5, four different CNVs were identified, variably present in the affected individuals; this included a 19p13.3 deletion affecting CACNA1A. Finally, in both Families 9 and 10, the proband had Dravet syndrome with pathogenic SCN1A variant, as well as a CNV (10q11.22 duplication in Family 9 and 22q11.2 deletion in Family 10). INTERPRETATION The significance of these specific variants is difficult to precisely determine; however, there appeared to be an overrepresentation of CNVs in this small cohort. These findings suggest chromosomal microarray analysis could have clinical utility as part of the workup in GEFS + families.
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Affiliation(s)
- Olivier Fortin
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada
| | - Christian Vincelette
- School of Nursing, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Sébastien Chénier
- Department of Pediatrics, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Ahmad Ghais
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Michael I Shevell
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada; Department of Neurology & Neurosurgery, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada; Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Elisabeth Simard-Tremblay
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada; Department of Neurology & Neurosurgery, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada
| | - Kenneth A Myers
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada; Department of Neurology & Neurosurgery, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada; Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
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Chow CY, Absalom N, Biggs K, King GF, Ma L. Venom-derived modulators of epilepsy-related ion channels. Biochem Pharmacol 2020; 181:114043. [PMID: 32445870 DOI: 10.1016/j.bcp.2020.114043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Epilepsy is characterised by spontaneous recurrent seizures that are caused by an imbalance between neuronal excitability and inhibition. Since ion channels play fundamental roles in the generation and propagation of action potentials as well as neurotransmitter release at a subset of excitatory and inhibitory synapses, their dysfunction has been linked to a wide variety of epilepsies. Indeed, these unique proteins are the major biological targets for antiepileptic drugs. Selective targeting of a specific ion channel subtype remains challenging for small molecules, due to the high level of homology among members of the same channel family. As a consequence, there is a growing trend to target ion channels with biologics. Venoms are the best known natural source of ion channel modulators, and venom peptides are increasingly recognised as potential therapeutics due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Here we describe the major ion channel families involved in the pathogenesis of various types of epilepsy, including voltage-gated Na+, K+, Ca2+ channels, Cys-loop receptors, ionotropic glutamate receptors and P2X receptors, and currently available venom-derived peptides that target these channel proteins. Although only a small number of venom peptides have successfully progressed to the clinic, there is reason to be optimistic about their development as antiepileptic drugs, notwithstanding the challenges associated with development of any class of peptide drug.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nathan Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kimberley Biggs
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia.
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GABRG2 Deletion Linked to Genetic Epilepsy with Febrile Seizures Plus Affects the Expression of GABA A Receptor Subunits and Other Genes at Different Temperatures. Neuroscience 2020; 438:116-136. [PMID: 32418750 DOI: 10.1016/j.neuroscience.2020.04.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/11/2022]
Abstract
Mutations in γ-aminobutyric acid A receptor (GABAA) subunits and sodium channel genes, especially GABRG2 and SCN1A, have been reported to be associated with febrile seizures (FS) and genetic epilepsy with febrile seizures plus (GEFS+). GEFS+ is a well-known family of epileptic syndrome with autosomal dominant inheritance in children. Its most common phenotypes are febrile seizures often with accessory afebrile generalized tonic-clonic seizures, febrile seizures plus (FS+), severe epileptic encephalopathy, as well as other types of generalized or localization-related seizures. However, the pathogenesis of febrile seizures remains largely unknown. Here, we generated a GABRG2 gene knockout cell line (HT22GABRG2KO) by applying the CRISPR/Cas9-mediated genomic deletion in HT-22 mouse hippocampal neuronal cell line to explore the function of GABRG2 in vitro. With mRNA-seq, we found significant changes in the expression profiles of several epilepsy-related genes when GABRG2 was knockout, some of them showing temperature-induced changes as well. Kyoto Encyclopedia Gene and Genomic (KEGG) analysis revealed a significant alteration in the MAPK and PI3K-Akt signaling pathways. We also observed an up-regulation of the matrix metalloproteinases (MMPs) family after GABRG2 knockout. Furthermore, the significant decrease in expression of GABRA1 and CACNA1A (but not others) with an increase in temperature is a novel finding. In summary, mutations in the GABAA receptor can lead to a decrease in numbers of receptors, which may cause the impairment of GABAergic pathway signaling. This data has been the first time to reveal that GABRG2 mutations would affect the function of other genes, and based on this finding we hope this work would also provide a new direction for the research of GABRG2 in GEFS+. It also may provide a molecular basis for the severity of epilepsy, and guide the clinical medication for the treatment of the epilepsy focused on the function on GABAA receptors, which, might be a new strategy for genetic diagnosis and targeted treatment of epilepsy.
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Maljevic S, Keren B, Aung YH, Forster IC, Mignot C, Buratti J, Lafitte A, Freihuber C, Rodan LH, Bergin A, Hubert L, Poirier K, Munnich A, Besmond C, Hauser N, Miller R, McWalter K, Nabbout R, Héron D, Leguern E, Depienne C, Petrou S, Nava C. Novel GABRA2 variants in epileptic encephalopathy and intellectual disability with seizures. Brain 2020; 142:e15. [PMID: 31032849 DOI: 10.1093/brain/awz079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Boris Keren
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France
| | - Ye Htet Aung
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Ian C Forster
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Cyril Mignot
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France.,Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Julien Buratti
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France
| | - Aurélie Lafitte
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France
| | - Cécile Freihuber
- AP-HP, Hôpital Trousseau, Service de Neuropédiatrie, Paris, France
| | - Lance H Rodan
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ann Bergin
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Laurence Hubert
- INSERM UMR 1163, Translational Genetics Lab., Paris-Descartes University, Imagine Institute, Paris, France
| | - Karine Poirier
- INSERM UMR 1163, Translational Genetics Lab., Paris-Descartes University, Imagine Institute, Paris, France
| | - Arnold Munnich
- INSERM UMR 1163, Translational Genetics Lab., Paris-Descartes University, Imagine Institute, Paris, France
| | - Claude Besmond
- INSERM UMR 1163, Translational Genetics Lab., Paris-Descartes University, Imagine Institute, Paris, France
| | - Natalie Hauser
- Inova Health System, Inova Translational Medicine Institute, Falls Church, VA, USA
| | - Rebecca Miller
- Inova Health System, Inova Translational Medicine Institute, Falls Church, VA, USA
| | | | - Rima Nabbout
- APHP, Hôpital Necker Enfants Malades, Centre de référence épilepsies rares, Service de Neurologie pédiatrique, Paris, France
| | - Delphine Héron
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France
| | - Eric Leguern
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France.,Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Christel Depienne
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France.,Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Caroline Nava
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», Paris, France.,Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
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Jenkins A, Escayg A. Reply: Novel GABRA2 variants in epileptic encephalopathy and intellectual disability with seizures. Brain 2020; 142:e16. [PMID: 31032848 DOI: 10.1093/brain/awz086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Andrew Jenkins
- Departments of Anesthesiology and Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, Georgia, USA
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Xie Y, Ng NN, Safrina OS, Ramos CM, Ess KC, Schwartz PH, Smith MA, O'Dowd DK. Comparisons of dual isogenic human iPSC pairs identify functional alterations directly caused by an epilepsy associated SCN1A mutation. Neurobiol Dis 2019; 134:104627. [PMID: 31786370 DOI: 10.1016/j.nbd.2019.104627] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/05/2019] [Accepted: 09/26/2019] [Indexed: 02/06/2023] Open
Abstract
Over 1250 mutations in SCN1A, the Nav1.1 voltage-gated sodium channel gene, are associated with seizure disorders including GEFS+. To evaluate how a specific mutation, independent of genetic background, causes seizure activity we generated two pairs of isogenic human iPSC lines by CRISPR/Cas9 gene editing. One pair is a control line from an unaffected sibling, and the mutated control carrying the GEFS+ K1270T SCN1A mutation. The second pair is a GEFS+ patient line with the K1270T mutation, and the corrected patient line. By comparing the electrophysiological properties in inhibitory and excitatory iPSC-derived neurons from these pairs, we found the K1270T mutation causes cell type-specific alterations in sodium current density and evoked firing, resulting in hyperactive neural networks. We also identified differences associated with genetic background and interaction between the mutation and genetic background. Comparisons within and between dual pairs of isogenic iPSC-derived neuronal cultures provide a novel platform for evaluating cellular mechanisms underlying a disease phenotype and for developing patient-specific anti-seizure therapies.
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Affiliation(s)
- Yunyao Xie
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Nathan N Ng
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Olga S Safrina
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Carmen M Ramos
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Kevin C Ess
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Philip H Schwartz
- Children's Hospital of Orange County Research Institute, Orange, CA, United States of America
| | - Martin A Smith
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Diane K O'Dowd
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America.
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Liao M, Kundap U, Rosch RE, Burrows DRW, Meyer MP, Ouled Amar Bencheikh B, Cossette P, Samarut É. Targeted knockout of GABA-A receptor gamma 2 subunit provokes transient light-induced reflex seizures in zebrafish larvae. Dis Model Mech 2019; 12:dmm.040782. [PMID: 31582559 PMCID: PMC6899022 DOI: 10.1242/dmm.040782] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/24/2019] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a common primary neurological disorder characterized by the chronic tendency of a patient to experience epileptic seizures, which are abnormal body movements or cognitive states that result from excessive, hypersynchronous brain activity. Epilepsy has been found to have numerous etiologies and, although about two-thirds of epilepsies were classically considered idiopathic, the majority of those are now believed to be of genetic origin. Mutations in genes involved in gamma-aminobutyric acid (GABA)-mediated inhibitory neurotransmission have been associated with a broad range of epilepsy syndromes. Mutations in the GABA-A receptor gamma 2 subunit gene (GABRG2), for example, have been associated with absence epilepsy and febrile seizures in humans. Several rodent models of GABRG2 loss of function depict clinical features of the disease; however, alternative genetic models more amenable for the study of ictogenesis and for high-throughput screening purposes are still needed. In this context, we generated a gabrg2 knockout (KO) zebrafish model (which we called R23X) that displayed light/dark-induced reflex seizures. Through high-resolution in vivo calcium imaging of the brain, we showed that this phenotype is associated with widespread increases in neuronal activity that can be effectively alleviated by the anti-epileptic drug valproic acid. Moreover, these seizures only occur at the larval stages but disappear after 1 week of age. Interestingly, our whole-transcriptome analysis showed that gabrg2 KO does not alter the expression of genes in the larval brain. As a result, the gabrg2−/− zebrafish is a novel in vivo genetic model of early epilepsies that opens new doors to investigate ictogenesis and for further drug-screening assays. Summary: The authors present a novel in vivo genetic model of idiopathic epilepsy in zebrafish (gabrg2−/−) to aid the study of ictogenesis and provide a convenient genetic tool for drug screening.
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Affiliation(s)
- Meijiang Liao
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Uday Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Richard E Rosch
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Dominic R W Burrows
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Martin P Meyer
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department for Developmental Neurobiology, Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Bouchra Ouled Amar Bencheikh
- Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada.,Neuroscience Department, Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Patrick Cossette
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Éric Samarut
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada .,Modelis Inc., Montréal, QC H2X 0A9, Canada
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