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Ramirez-Franco J, Debreux K, Sangiardi M, Belghazi M, Kim Y, Lee SH, Lévêque C, Seagar M, El Far O. The downregulation of Kv 1 channels in Lgi1 -/-mice is accompanied by a profound modification of its interactome and a parallel decrease in Kv 2 channels. Neurobiol Dis 2024; 196:106513. [PMID: 38663634 DOI: 10.1016/j.nbd.2024.106513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 03/12/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024] Open
Abstract
In animal models of LGI1-dependent autosomal dominant lateral temporal lobe epilepsy, Kv1 channels are downregulated, suggesting their crucial involvement in epileptogenesis. The molecular basis of Kv1 channel-downregulation in LGI1 knock-out mice has not been elucidated and how the absence of this extracellular protein induces an important modification in the expression of Kv1 remains unknown. In this study we analyse by immunofluorescence the modifications in neuronal Kv1.1 and Kv1.2 distribution throughout the hippocampal formation of LGI1 knock-out mice. We show that Kv1 downregulation is not restricted to the axonal compartment, but also takes place in the somatodendritic region and is accompanied by a drastic decrease in Kv2 expression levels. Moreover, we find that the downregulation of these Kv channels is associated with a marked increase in bursting patterns. Finally, mass spectrometry uncovered key modifications in the Kv1 interactome that highlight the epileptogenic implication of Kv1 downregulation in LGI1 knock-out animals.
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Affiliation(s)
- Jorge Ramirez-Franco
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
| | - Kévin Debreux
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Marion Sangiardi
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Maya Belghazi
- Marseille Protéomique (MaP), Plateforme Protéomique IMM, CNRS FR3479, Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13009 Marseille, France
| | - Yujin Kim
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Suk-Ho Lee
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Christian Lévêque
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Michael Seagar
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Oussama El Far
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
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Cetica V, Pisano T, Lesca G, Marafi D, Licchetta L, Riccardi F, Mei D, Chung HYB, Bayat A, Balasubramanian M, Lowenstein DH, Endzinienė M, Alotaibi M, Villeneuve N, Jacobs J, Isidor B, Solazzi R, den Hollander NS, Marjanovic D, Rougeot-Jung C, Jung J, Lesieur-Sebellin M, Accogli A, Salpietro V, Saadi NW, Panagiotakaki E, Foiadelli T, Redon S, Tsai MH, Bisulli F, Hammer TB, Lupski JR, Parrini E, Guerrini R. Clinical and molecular characterization of patients with YWHAG-related epilepsy. Epilepsia 2024; 65:1439-1450. [PMID: 38491959 DOI: 10.1111/epi.17939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/15/2024] [Accepted: 02/22/2024] [Indexed: 03/18/2024]
Abstract
OBJECTIVE YWHAG variant alleles have been associated with a rare disease trait whose clinical synopsis includes an early onset epileptic encephalopathy with predominantly myoclonic seizures, developmental delay/intellectual disability, and facial dysmorphisms. Through description of a large cohort, which doubles the number of reported patients, we further delineate the spectrum of YWHAG-related epilepsy. METHODS We included in this study 24 patients, 21 new and three previously described, with pathogenic/likely pathogenic variants in YWHAG. We extended the analysis of clinical, electroencephalographic, brain magnetic resonance imaging, and molecular genetic information to 24 previously published patients. RESULTS The phenotypic spectrum of YWHAG-related disorders ranges from mild developmental delay to developmental and epileptic encephalopathy (DEE). Epilepsy onset is in the first 2 years of life. Seizure freedom can be achieved in half of the patients (13/24, 54%). Intellectual disability (23/24, 96%), behavioral disorders (18/24, 75%), neurological signs (13/24, 54%), and dysmorphisms (6/24, 25%) are common. A genotype-phenotype correlation emerged, as DEE is more represented in patients with missense variants located in the ligand-binding domain than in those with truncating or missense variants in other domains (90% vs. 19%, p < .001). SIGNIFICANCE This study suggests that pathogenic YWHAG variants cause a wide range of clinical presentations with variable severity, ranging from mild developmental delay to DEE. In this allelic series, a genotype-phenotype correlation begins to emerge, potentially providing prognostic information for clinical management and genetic counseling.
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Affiliation(s)
- Valentina Cetica
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Tiziana Pisano
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Gaetan Lesca
- Université Lyon 1, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Physiopathologie et Génétique du Neurone et du Muscle, Institut NeuroMyoGène, Lyon, France
- Department of Genetics, University Hospitals of Lyon, Hospices Civils de Lyon, Lyon, France
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Department of Pediatrics, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Laura Licchetta
- Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, Istituto delle Scienze Neurologiche di Bologna, full member of the European Reference Network EpiCARE, Bologna, Italy
| | - Florence Riccardi
- Aix-Marseille University, Institut National de la Santé et de la Recherche Médicale (INSERM), Marseille Medical Genetics, Marseille, France
- Centre Hospitalier Intercommunal Toulon - La Seyne sur Mer (CHITS), Hôpital Ste Musse, Service de Génétique Médicale, Toulon, France
| | - Davide Mei
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Hon-Yin B Chung
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing (LKS) Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Allan Bayat
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
| | - Meena Balasubramanian
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
- Sheffield Clinical Genetics Service, Sheffield Children's National Health Service (NHS) Foundation Trust, Sheffield, UK
| | - Daniel H Lowenstein
- Department of Neurology, University of California, San Francisco, California, USA
| | - Milda Endzinienė
- Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | - Nathalie Villeneuve
- Depatment of Pediatric Neurology, Assistance Publique-Hopitaux de Marseille (AP-HM), Hôpital de la Timone Enfants, Marseille, France
| | - Julia Jacobs
- Alberta Children's Research Institute, Hodgekiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Bertrand Isidor
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
- Université de Nantes, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), l'Institut du Thorax, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Roberta Solazzi
- Department of Pediatric Neuroscience, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | | | | | - Julien Jung
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, Université de Lyon, Lyon, France
| | - Marion Lesieur-Sebellin
- Department of Genomic Medicine of Rare Disorders, Necker Hospital, University Paris Cité, Paris, France
| | - Andrea Accogli
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Vincenzo Salpietro
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Nebal W Saadi
- College of Medicine, University of Baghdad, Baghdad, Iraq
- Children Welfare Teaching Hospital, Baghdad, Iraq
| | - Eleni Panagiotakaki
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, Université de Lyon, Lyon, France
| | - Thomas Foiadelli
- Clinica Pediatrica, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico IRCCS Policlinico San Matteo, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, Pavia, Italy
| | - Sylvia Redon
- Service de Génétique Médicale, Centre Hospitalier et Universitaire de Brest, Brest, France
- Université de Brest, Institut National de la Santé et de la Recherche Médicale (INSERM), Etablissement Français du Sang, UMR 1078, Brest, France
- Centre de Référence Déficiences Intellectuelles de Causes Rares, Brest, France
| | - Meng-Han Tsai
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
- School of Medicine, Chang Gung University, Kaohsiung, Taiwan
| | - Francesca Bisulli
- Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, Istituto delle Scienze Neurologiche di Bologna, full member of the European Reference Network EpiCARE, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Trine B Hammer
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Elena Parrini
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, Italy
- University of Florence, Florence, Italy
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Amin AK, Krause J, Eggermann T. 11p13 microduplication: a differential diagnosis of Silver-Russell syndrome? Mol Cytogenet 2024; 17:5. [PMID: 38486332 PMCID: PMC10941370 DOI: 10.1186/s13039-024-00672-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/21/2024] [Indexed: 03/17/2024] Open
Abstract
BACKGROUND Silver-Russel syndrome (SRS) is a congenital disorder which is mainly characterized by intrauterine and postnatal growth retardation, relative macrocephaly, and characteristic (facial) dysmorphisms. The majority of patients shows a hypomethylation of the imprinting center region 1 (IC1) in 11p15 and maternal uniparental disomy of chromosome 7 (upd(7)mat), but in addition a broad spectrum of copy number variations (CNVs) and monogenetic variants (SNVs) has been reported in this cohort. These heterogeneous findings reflect the clinical overlap of SRS with other congenital disorders, but some of the CNVs are recurrent and have therefore been suggested as SRS-associated loci. However, this molecular heterogeneity makes the decision on the diagnostic workup of patients with SRS features challenging. CASE PRESENTATION A girl with clinical features of SRS but negatively tested for the IC1 hypomethylation and upd(7)mat was analyzed by whole genome sequencing in order to address both CNVs and SNVs in the same run. We identified a 11p13 microduplication affecting a region overlapping with a variant reported in a previously published patient with clinical features of Silver-Russel syndrome. CONCLUSIONS The identification of a 11p13 microduplication in a patient with SRS features confirms the considerable contribution of CNVs to SRS-related phenotypes, and it strengthens the evidence for a 11p13 microduplication syndrome as a differential diagnosis SRS. Furthermore, we could confirm that WGS is a valuable diagnostic tool in patients with SRS and related disorders, as it allows CNVs and SNV detection in the same run, thereby avoiding a time-consuming diagnostic testing process.
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Affiliation(s)
- Asmaa K Amin
- Department of Human Genetics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Jeremias Krause
- Institute for Human Genetics and Genome Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Thomas Eggermann
- Institute for Human Genetics and Genome Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.
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Sedlackova L, Sterbova K, Vlckova M, Seeman P, Zarubova J, Marusic P, Krsek P, Krijtova H, Musilova A, Lassuthova P. Yield of exome sequencing in patients with developmental and epileptic encephalopathies and inconclusive targeted gene panel. Eur J Paediatr Neurol 2024; 48:17-29. [PMID: 38008000 DOI: 10.1016/j.ejpn.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 10/25/2023] [Accepted: 10/28/2023] [Indexed: 11/28/2023]
Abstract
OBJECTIVE Developmental and epileptic encephalopathies (DEEs) are a group of severe, early-onset epilepsies characterised by refractory seizures, developmental delay, or regression and generally poor prognosis. DEE are now known to have an identifiable molecular genetic basis and are usually examined using a gene panel. However, for many patients, the genetic cause has still not been identified. The aims of this study were to identify causal variants for DEE in patients for whom the previous examination with a gene panel did not determine their genetic diagnosis. It also aims for a detailed description and broadening of the phenotypic spectrum of several rare DEEs. METHODS In the last five years (2015-2020), 141 patients from all over the Czech Republic were referred to our department for genetic testing in association with their diagnosis of epilepsy. All patients underwent custom-designed gene panel testing prior to enrolment into the study, and their results were inconclusive. We opted for whole exome sequencing (WES) to identify the cause of their disorder. If a causal or potentially causal variant was identified, we performed a detailed clinical evaluation and phenotype-genotype correlation study to better describe the specific rare subtypes. RESULTS Explanatory causative variants were detected in 20 patients (14%), likely pathogenic variants that explain the epilepsy in 5 patients (3.5%) and likely pathogenic variants that do not fully explain the epilepsy in 11 patients (7.5%), and variants in candidate genes in 4 patients (3%). Variants were mostly de novo 29/40 (72.5%). SIGNIFICANCE WES enables us to identify the cause of the disease in additional patients, even after gene panel testing. It is very important to perform a WES in DEE patients as soon as possible, since it will spare the patients and their families many years of a diagnostic odyssey. In particular, patients with rare epilepsies might significantly benefit from this approach, and we propose using WES as a new standard in the diagnosis of DEE instead of targeted gene panel testing.
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Affiliation(s)
- Lucie Sedlackova
- Neurogenetic Laboratory, Department of Paediatric Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Katalin Sterbova
- Department of Paediatric Neurology, Second Faculty of Medicine, Motol Epilepsy Center, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Marketa Vlckova
- Department of Biology and Medical Genetics, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Pavel Seeman
- Neurogenetic Laboratory, Department of Paediatric Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic; Department of Medical Genetics, Masaryk Hospital, Ústí nad Labem, Czech Republic.
| | - Jana Zarubova
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Petr Marusic
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Pavel Krsek
- Department of Paediatric Neurology, Second Faculty of Medicine, Motol Epilepsy Center, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Hana Krijtova
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Alena Musilova
- Neurogenetic Laboratory, Department of Paediatric Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
| | - Petra Lassuthova
- Neurogenetic Laboratory, Department of Paediatric Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Full Member of the ERN EpiCARE, Czech Republic.
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Buccoliero AM, Caporalini C, Moscardi S, Cetica V, Mei D, Conti V, Nozzoli F, Bonaudo C, Battista F, Giordano F, Mura R, Spacca B, Mussa F, D'Onofrio V, Guerrini R, Genitori L, Scagnet M. Leat-associated seizures the possible role of EAAT2, pyruvate carboxylase and glutamine synthetase. Epilepsy Res 2024; 199:107258. [PMID: 38086219 DOI: 10.1016/j.eplepsyres.2023.107258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Drug-resistant epilepsy is a common condition in patients with brain neoplasms. The pathogenesis of tumor-associated seizures is poorly understood. Among the possible pathogenetic mechanisms, the increase in glutamate concentration has been proposed. Glutamate transporters, glutamine synthetase and pyruvate carboxylase are involved in maintaining the physiological concentration of glutamate in the intersynaptic spaces. In our previous research on angiocentric gliomas, we demonstrated that all tumors lacked the expression of the main glutamate transporter EAAT2, while the expression of glutamine synthetase and pyruvate carboxylase was mostly preserved. METHODS In the present study, we evaluated the immunohistochemical expression of EAAT2, glutamine synthetase and pyruvate carboxylase in a heterogeneous series of 25 long-term epilepsy-associated tumors (10 dysembryoplastic neuroepithelial tumors, 7 gangliogliomas, 3 subependymal giant cell astrocytomas, 3 rosette forming glioneuronal tumors, 1 diffuse astrocytoma MYB- or MYBL1-altered and 1 angiocentric glioma). In order to evaluate the incidence of variants in the SLC1A2 gene, encoding EAAT2, in a large number of central nervous system tumors we also queried the PedcBioPortal. RESULTS EAAT2 protein expression was lost in 9 tumors (36 %: 3 dysembryoplastic neuroepithelial tumors, 1 ganglioglioma, 3 subependymal giant cell astrocytomas, 1 diffuse astrocytoma MYB- or MYBL1-altered and 1 angiocentric glioma). Glutamine synthetase protein expression was completely lost in 2 tumors (8 %; 1 ganglioglioma and 1 diffuse astrocytoma MYB- or MYBL1-altered). All tumors of our series but rosette forming glioneuronal tumors (in which neurocytic cells were negative) were diffusely positive for pyruvate carboxylase. Consultation of the PedcBioPortal revealed that of 2307 pediatric brain tumors of different histotype and grade, 20 (< 1%) had variants in the SLC1A2 gene. Among the SLC1A2-mutated tumors, there were no angiocentric gliomas or other LEATs CONCLUSIONS: In conclusion, unlike angiocentric gliomas where the EAAT2 loss is typical and constant, the current study shows the loss of EAAT2 expression only in a fraction of the LEATs. In these cases, we may hypothesize some possible epileptogenic role of the EAAT2 loss. The retained expression of pyruvate carboxylase may contribute to determining a pathological glutamate excess unopposed by glutamine synthetase that resulted expressed to a variable extent in the majority of the tumors. Furthermore, we can assume that the EAAT2 loss in brain tumors in general and in LEATs in particular is more conceivably epigenetic.
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Affiliation(s)
| | | | - Selene Moscardi
- Pathology Unit, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Valentina Cetica
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Davide Mei
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Valerio Conti
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Filippo Nozzoli
- Histopathology and Molecular Diagnostics, Careggi University Hospital, Florence, Italy
| | - Camilla Bonaudo
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), Careggi University Hospital, Florence, Italy
| | - Francesca Battista
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), Careggi University Hospital, Florence, Italy
| | - Flavio Giordano
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Regina Mura
- Department of Neurosurgery, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Barbara Spacca
- Department of Neurosurgery, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Federico Mussa
- Department of Neurosurgery, Meyer Children's Hospital IRCCS, Florence, Italy
| | | | - Renzo Guerrini
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Lorenzo Genitori
- Department of Neurosciences, Psychology, Drug Research, and Child Health (NEUROFARBA), Careggi University Hospital, Florence, Italy
| | - Mirko Scagnet
- Department of Neurosurgery, Meyer Children's Hospital IRCCS, Florence, Italy
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Suslova M, Kortzak D, Machtens JP, Kovermann P, Fahlke C. Apo state pore opening as functional basis of increased EAAT anion channel activity in episodic ataxia 6. Front Physiol 2023; 14:1147216. [PMID: 37538371 PMCID: PMC10394623 DOI: 10.3389/fphys.2023.1147216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 07/07/2023] [Indexed: 08/05/2023] Open
Abstract
SLC1A2 and SLC1A3 encode the glial glutamate transporters EAAT2 and EAAT1, which are not only the predominant glutamate uptake carriers in our brain, but also function as anion channels. Two homologous mutations, which predict substitutions of prolines in the center of the fifth transmembrane helix by arginine (P289R EAAT2, P290R EAAT1), have been identified in patients with epileptic encephalopathy (SLC1A2) or with episodic ataxia type 6 (SLC1A3). Both mutations have been shown to impair glutamate uptake and to increase anion conduction. The molecular processes that link the disease-causing mutations to two major alterations of glutamate transporter function remain insufficiently understood. The mutated proline is conserved in every EAAT. Since the pathogenic changes mainly affect the anion channel function, we here study the functional consequences of the homologous P312R mutation in the neuronal glutamate transporter EAAT4, a low capacity glutamate transporter with predominant anion channel function. To assess the impact of charge and structure of the inserted amino acid for the observed functional changes, we generated and functionally evaluated not only P312R, but also substitutions of P312 with all other amino acids. However, only exchange of proline by arginine, lysine, histidine and asparagine were functionally tolerated. We compared WT, P312R and P312N EAAT4 using a combination of cellular electrophysiology, fast substrate application and kinetic modelling. We found that WT and mutant EAAT4 anion currents can be described with a 11-state model of the transport cycle, in which several states are connected to branching anion channel states to account for the EAAT anion channel function. Substitutions of P312 modify various transitions describing substrate binding/unbinding, translocation or anion channel opening. Most importantly, P312R generates a new anion conducting state that is accessible in the outward facing apo state and that is the main determinant of the increased anion conduction of EAAT transporters carrying this mutation. Our work provides a quantitative description how a naturally occurring mutation changes glutamate uptake and anion currents in two genetic diseases.
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Pan X, Yi X, Lan M, Su X, Zhou F, Wu W. Research on the pathological mechanism of rectal adenocarcinoma based on DNA methylation. Medicine (Baltimore) 2023; 102:e32763. [PMID: 36705386 PMCID: PMC9876001 DOI: 10.1097/md.0000000000032763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Colorectal cancer is one of the 3 most common cancers worldwide. In this study, a weighted network-based analysis method was proposed to explore the pathological mechanisms and prognostic targets of rectal adenocarcinoma (READ) at the deoxyribonucleic acid (DNA) methylation level. In this study, we downloaded clinical information and DNA methylation data from The Cancer Genome Atlas database. Differentially methylated gene analysis was used to identify the differential methylated genes in READ. Canonical correlation analysis was used to construct the weighted gene regulatory network for READ. Multilevel analysis and association analyses between gene modules and clinical information were used to mine key modules related to tumor metastasis evaluation. Genetic significance analysis was used to identify methylation sites in key modules. Finally, the importance of these methylation sites was confirmed using survival analysis. DNA methylation datasets from 90 cancer tissue samples and 6 paracancerous tissue samples were selected. A weighted gene regulatory network was constructed, and a multilevel algorithm was used to divide the gene co-expression network into 20 modules. From gene ontology enrichment analysis, characteristic M was related to biological processes such as the chemotaxis of fibroblast growth factors and the activation and regulation of immune cells etc and characteristic N was associated with the regulation of cytoskeleton formation, mainly microtubules and flagella, regulation of synapses, and regulation of cell mitosis. Based on the results of survival analysis, 7 key methylation sites were found closely correlated to the survival rate of READ, such as cg04441191 (microtubule-associated protein 4 [MAP4]), cg05658717 (KSR2), cg09622330 (GRIN2A), cg10698404 (YWHAG), cg17047993 (SPAG9), cg24504843 (CEP135), and cg24531267 (CEP250). Mutational and transcriptomic level studies revealed significant differences in DNA methylation, single nucleotide polymorphism, and transcript levels between YWHAG and MAP4 in normal tissues compared to tumor tissues, and differential expression of the 2 proteins in immunohistochemistry. Therefore, potential targeting drugs were screened for these 2 proteins for molecular docking, and artenimol was found to bind to MAP4 protein and 27-hydroxycholesterol to YWHAG. Our study found that key methylation sites played an important role in tumor metastasis and were associated with the prognosis of READ. Mutations and methylation may jointly regulate the transcription and translation of related genes, which in turn affect cancer progression. This may provide some new potential therapeutic targets and thoughts for the prognosis of READ.
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Affiliation(s)
- Xiaoqiang Pan
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xingcheng Yi
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Maozhuo Lan
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xiaoyun Su
- School of Pharmaceutical Sciences, Jilin University, Changchun, China
| | - Fang Zhou
- Equipment Division, Zhijiang People’s Hospital, Yichang, Hubei, China
| | - Wei Wu
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin, China
- * Correspondence: Wei Wu, Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130012, China (e-mail: )
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8
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Alijanpour S, Miryounesi M, Ghafouri-Fard S. The role of excitatory amino acid transporter 2 (EAAT2) in epilepsy and other neurological disorders. Metab Brain Dis 2023; 38:1-16. [PMID: 36173507 DOI: 10.1007/s11011-022-01091-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/15/2022] [Indexed: 02/03/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system (CNS). Excitatory amino acid transporters (EAATs) have important roles in the uptake of glutamate and termination of glutamatergic transmission. Up to now, five EAAT isoforms (EAAT1-5) have been identified in mammals. The main focus of this review is EAAT2. This protein has an important role in the pathoetiology of epilepsy. De novo dominant mutations, as well as inherited recessive mutation in this gene, have been associated with epilepsy. Moreover, dysregulation of this protein is implicated in a range of neurological diseases, namely amyotrophic lateral sclerosis, alzheimer's disease, parkinson's disease, schizophrenia, epilepsy, and autism. In this review, we summarize the role of EAAT2 in epilepsy and other neurological disorders, then provide an overview of the therapeutic modulation of this protein.
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Affiliation(s)
- Sahar Alijanpour
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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9
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Qu Q, Zhang W, Wang J, Mai D, Ren S, Qu S, Zhang Y. Functional investigation of SLC1A2 variants associated with epilepsy. Cell Death Dis 2022; 13:1063. [PMID: 36543780 DOI: 10.1038/s41419-022-05457-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022]
Abstract
Epilepsy is a common neurological disorder and glutamate excitotoxicity plays a key role in epileptic pathogenesis. Astrocytic glutamate transporter GLT-1 is responsible for preventing excitotoxicity via clearing extracellular accumulated glutamate. Previously, three variants (G82R, L85P, and P289R) in SLC1A2 (encoding GLT-1) have been clinically reported to be associated with epilepsy. However, the functional validation and underlying mechanism of these GLT-1 variants in epilepsy remain undetermined. In this study, we reported that these disease-linked mutants significantly decrease glutamate uptake, cell membrane expression of the glutamate transporter, and glutamate-elicited current. Additionally, we found that these variants may disturbed stromal-interacting molecule 1 (STIM1)/Orai1-mediated store-operated Ca2+ entry (SOCE) machinery in the endoplasmic reticulum (ER), in which GLT-1 may be a new partner of SOCE. Furthermore, knock-in mice with disease-associated variants showed a hyperactive phenotype accompanied by reduced glutamate transporter expression. Therefore, GLT-1 is a promising and reliable therapeutic target for epilepsy interventions.
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10
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Feng Y, Zhang C, Wei Z, Li G, Gan Y, Liu C, Deng Y. Gene variations of glutamate metabolism pathway and epilepsy. Acta Epileptologica 2022. [DOI: 10.1186/s42494-022-00103-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Epilepsy is a paroxysmal disorder of the brain, caused by an imbalance of neuronal excitation and inhibition. Glutamate is the most important excitatory neurotransmitter in the brain and plays an important role in epileptogenesis. Mutations in genes at any step/component of the glutamate metabolic pathway may lead to the development of epilepsy or epileptic encephalopathy.
Methods
Clinical history of 3 epilepsy patients with genetic variations of the glutamate metabolism pathway was collected. Electroencephalogram recording and magnetic resonance imaging were performed in each patient. We also reviewed recent literature for a variety of the genetic variations involved in epilepsy.
Results
Case 1 was a SLC1A2 mutation-carrier diagnosed with developmental and epileptic encephalopathy (DEE) 41, whose seizures decreased after start of the ketogenic diet. Case 2 carried a GRIN2A gene mutation and was seizure-free for three years after taking levetiracetam and vitamin B6. Case 3 was a GRIN2B mutation-carrier diagnosed with DEE 27, who seizures diminished after taking oxcarbazepine.
Conclusions
Preclinical and clinical evidence supports the therapeutic potential of glutamatergic signaling-targeting treatments for epilepsy. More studies are needed to discover novel DEE-related genetic mutations in the glutamate metabolic pathway.
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11
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Gokce-Samar Z, de Bellescize J, Arzimanoglou A, Putoux A, Chatron N, Lesca G, Portes VD. STAG2 microduplication in a patient with eyelid myoclonia and absences and a review of EMA-related reported genes. Eur J Med Genet 2022; 65:104636. [DOI: 10.1016/j.ejmg.2022.104636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 03/14/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022]
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12
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Archer SL, Dasgupta A, Chen KH, Wu D, Baid K, Mamatis JE, Gonzalez V, Read A, Bentley RET, Martin AY, Mewburn JD, Dunham-Snary KJ, Evans GA, Levy G, Jones O, Al-Qazazi R, Ring B, Alizadeh E, Hindmarch CCT, Rossi J, Lima PDA, Falzarano D, Banerjee A, Colpitts CC. SARS-CoV-2 mitochondriopathy in COVID-19 pneumonia exacerbates hypoxemia. Redox Biol 2022; 58:102508. [PMID: 36334378 PMCID: PMC9558649 DOI: 10.1016/j.redox.2022.102508] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/09/2022] [Indexed: 11/05/2022] Open
Abstract
Rationale Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 pneumonia. We hypothesize that SARS-CoV-2 causes alveolar injury and hypoxemia by damaging mitochondria in airway epithelial cells (AEC) and pulmonary artery smooth muscle cells (PASMC), triggering apoptosis and bioenergetic impairment, and impairing hypoxic pulmonary vasoconstriction (HPV), respectively. Objectives We examined the effects of: A) human betacoronaviruses, SARS-CoV-2 and HCoV-OC43, and individual SARS-CoV-2 proteins on apoptosis, mitochondrial fission, and bioenergetics in AEC; and B) SARS-CoV-2 proteins and mouse hepatitis virus (MHV-1) infection on HPV. Methods We used transcriptomic data to identify temporal changes in mitochondrial-relevant gene ontology (GO) pathways post-SARS-CoV-2 infection. We also transduced AECs with SARS-CoV-2 proteins (M, Nsp7 or Nsp9) and determined effects on mitochondrial permeability transition pore (mPTP) activity, relative membrane potential, apoptosis, mitochondrial fission, and oxygen consumption rates (OCR). In human PASMC, we assessed the effects of SARS-CoV-2 proteins on hypoxic increases in cytosolic calcium, an HPV proxy. In MHV-1 pneumonia, we assessed HPV via cardiac catheterization and apoptosis using the TUNEL assay. Results SARS-CoV-2 regulated mitochondrial apoptosis, mitochondrial membrane permeabilization and electron transport chain (ETC) GO pathways within 2 hours of infection. SARS-CoV-2 downregulated ETC Complex I and ATP synthase genes, and upregulated apoptosis-inducing genes. SARS-CoV-2 and HCoV-OC43 upregulated and activated dynamin-related protein 1 (Drp1) and increased mitochondrial fission. SARS-CoV-2 and transduced SARS-CoV-2 proteins increased apoptosis inducing factor (AIF) expression and activated caspase 7, resulting in apoptosis. Coronaviruses also reduced OCR, decreased ETC Complex I activity and lowered ATP levels in AEC. M protein transduction also increased mPTP opening. In human PASMC, M and Nsp9 proteins inhibited HPV. In MHV-1 pneumonia, infected AEC displayed apoptosis and HPV was suppressed. BAY K8644, a calcium channel agonist, increased HPV and improved SpO2. Conclusions Coronaviruses, including SARS-CoV-2, cause AEC apoptosis, mitochondrial fission, and bioenergetic impairment. SARS-CoV-2 also suppresses HPV by targeting mitochondria. This mitochondriopathy is replicated by transduction with SARS-CoV-2 proteins, indicating a mechanistic role for viral-host mitochondrial protein interactions. Mitochondriopathy is a conserved feature of coronaviral pneumonia that may exacerbate hypoxemia and constitutes a therapeutic target.
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Affiliation(s)
- Stephen L. Archer
- Department of Medicine, Queen’s University, Kingston, ON, Canada,Queen’s Cardiopulmonary Unit (QCPU), Queen’s University, Kingston, ON, Canada,Corresponding author. Head Department of Medicine, Queen's University Etherington Hall, Room 3041 94 Stuart St., Kingston, Ontario, K7L 3N6, Canada
| | - Asish Dasgupta
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Kuang-Hueih Chen
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Danchen Wu
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Kaushal Baid
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada
| | - John E. Mamatis
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
| | - Victoria Gonzalez
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan; Saskatoon, SK, Canada
| | - Austin Read
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | | | - Ashley Y. Martin
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | | | - Kimberly J. Dunham-Snary
- Department of Medicine, Queen’s University, Kingston, ON, Canada,Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
| | - Gerald A. Evans
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Gary Levy
- University of Toronto, Toronto, ON, Canada
| | - Oliver Jones
- Queen’s Cardiopulmonary Unit (QCPU), Queen’s University, Kingston, ON, Canada
| | - Ruaa Al-Qazazi
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Brooke Ring
- Queen’s Cardiopulmonary Unit (QCPU), Queen’s University, Kingston, ON, Canada
| | - Elahe Alizadeh
- Queen’s Cardiopulmonary Unit (QCPU), Queen’s University, Kingston, ON, Canada
| | | | - Jenna Rossi
- Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Patricia DA. Lima
- Queen’s Cardiopulmonary Unit (QCPU), Queen’s University, Kingston, ON, Canada
| | - Darryl Falzarano
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan; Saskatoon, SK, Canada
| | - Arinjay Banerjee
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan; Saskatoon, SK, Canada,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada,Department of Biology, University of Waterloo; Waterloo, ON, Canada
| | - Che C. Colpitts
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
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13
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Kato T, Kusakizako T, Jin C, Zhou X, Ohgaki R, Quan L, Xu M, Okuda S, Kobayashi K, Yamashita K, Nishizawa T, Kanai Y, Nureki O. Structural insights into inhibitory mechanism of human excitatory amino acid transporter EAAT2. Nat Commun 2022; 13:4714. [PMID: 35953475 PMCID: PMC9372063 DOI: 10.1038/s41467-022-32442-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 08/01/2022] [Indexed: 11/18/2022] Open
Abstract
Glutamate is a pivotal excitatory neurotransmitter in mammalian brains, but excessive glutamate causes numerous neural disorders. Almost all extracellular glutamate is retrieved by the glial transporter, Excitatory Amino Acid Transporter 2 (EAAT2), belonging to the SLC1A family. However, in some cancers, EAAT2 expression is enhanced and causes resistance to therapies by metabolic disturbance. Despite its crucial roles, the detailed structural information about EAAT2 has not been available. Here, we report cryo-EM structures of human EAAT2 in substrate-free and selective inhibitor WAY213613-bound states at 3.2 Å and 2.8 Å, respectively. EAAT2 forms a trimer, with each protomer consisting of transport and scaffold domains. Along with a glutamate-binding site, the transport domain possesses a cavity that could be disrupted during the transport cycle. WAY213613 occupies both the glutamate-binding site and cavity of EAAT2 to interfere with its alternating access, where the sensitivity is defined by the inner environment of the cavity. We provide the characterization of the molecular features of EAAT2 and its selective inhibition mechanism that may facilitate structure-based drug design for EAAT2. EAAT2 is an amino acid transporter implicated in glutamate homeostasis in brain and therapy resistance of cancer cells. Here, the authors report cryo-EM structures and reveal inhibitory mechanisms via selective inhibitor WAY213613.
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Affiliation(s)
- Takafumi Kato
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Department of Biochemistry, The University of Oxford, Oxford, UK
| | - Tsukasa Kusakizako
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| | - Chunhuan Jin
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Xinyu Zhou
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Ryuichi Ohgaki
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiative (OTRI), Osaka University, Osaka, Japan
| | - LiLi Quan
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Minhui Xu
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Suguru Okuda
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kan Kobayashi
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Peptidream Inc, Kawasaki, Japan
| | - Keitaro Yamashita
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Tomohiro Nishizawa
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan. .,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiative (OTRI), Osaka University, Osaka, Japan.
| | - Osamu Nureki
- Department of Biological Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
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14
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Marafi D, Fatih JM, Kaiyrzhanov R, Ferla MP, Gijavanekar C, Al-Maraghi A, Liu N, Sites E, Alsaif HS, Al-Owain M, Zakkariah M, El-Anany E, Guliyeva U, Guliyeva S, Gaba C, Haseeb A, Alhashem AM, Danish E, Karageorgou V, Beetz C, Subhi AA, Mullegama SV, Torti E, Sebastin M, Breilyn MS, Duberstein S, Abdel-Hamid MS, Mitani T, Du H, Rosenfeld JA, Jhangiani SN, Coban Akdemir Z, Gibbs RA, Taylor JC, Fakhro KA, Hunter JV, Pehlivan D, Zaki MS, Gleeson JG, Maroofian R, Houlden H, Posey JE, Sutton VR, Alkuraya FS, Elsea SH, Lupski JR. Biallelic variants in SLC38A3 encoding a glutamine transporter cause epileptic encephalopathy. Brain 2022; 145:909-924. [PMID: 34605855 PMCID: PMC9050560 DOI: 10.1093/brain/awab369] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/13/2021] [Accepted: 08/26/2021] [Indexed: 11/14/2022] Open
Abstract
The solute carrier (SLC) superfamily encompasses >400 transmembrane transporters involved in the exchange of amino acids, nutrients, ions, metals, neurotransmitters and metabolites across biological membranes. SLCs are highly expressed in the mammalian brain; defects in nearly 100 unique SLC-encoding genes (OMIM: https://www.omim.org) are associated with rare Mendelian disorders including developmental and epileptic encephalopathy and severe neurodevelopmental disorders. Exome sequencing and family-based rare variant analyses on a cohort with neurodevelopmental disorders identified two siblings with developmental and epileptic encephalopathy and a shared deleterious homozygous splicing variant in SLC38A3. The gene encodes SNAT3, a sodium-coupled neutral amino acid transporter and a principal transporter of the amino acids asparagine, histidine, and glutamine, the latter being the precursor for the neurotransmitters GABA and glutamate. Additional subjects with a similar developmental and epileptic encephalopathy phenotype and biallelic predicted-damaging SLC38A3 variants were ascertained through GeneMatcher and collaborations with research and clinical molecular diagnostic laboratories. Untargeted metabolomic analysis was performed to identify novel metabolic biomarkers. Ten individuals from seven unrelated families from six different countries with deleterious biallelic variants in SLC38A3 were identified. Global developmental delay, intellectual disability, hypotonia, and absent speech were common features while microcephaly, epilepsy, and visual impairment were present in the majority. Epilepsy was drug-resistant in half. Metabolomic analysis revealed perturbations of glutamate, histidine, and nitrogen metabolism in plasma, urine, and CSF of selected subjects, potentially representing biomarkers of disease. Our data support the contention that SLC38A3 is a novel disease gene for developmental and epileptic encephalopathy and illuminate the likely pathophysiology of the disease as perturbations in glutamine homeostasis.
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Affiliation(s)
- Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Faculty of Medicine, Kuwait University, P.O. Box 24923, 13110 Safat, Kuwait
- Correspondence to: Dana Marafi, MD, MSc Department of Pediatrics, Faculty of Medicine, Kuwait University P.O. Box 24923, 13110 Safat, Kuwait E-mail:
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Rauan Kaiyrzhanov
- Department of Neuromuscular Disorders Institute of Neurology, University College London, Queen Square, London, UK
| | - Matteo P Ferla
- NIHR Oxford Biomedical Research Centre, Oxford OX4 2PG, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Charul Gijavanekar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratory, Houston, TX 77030, USA
| | | | - Ning Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratory, Houston, TX 77030, USA
| | - Emily Sites
- Division of Molecular and Human Genetics, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Hessa S Alsaif
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Mohammad Al-Owain
- Department of Medical Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University 11533, Riyadh, Saudi Arabia
| | - Mohamed Zakkariah
- Section of Child Neurology, Department of Pediatrics, Al-adan Hospital, Riqqa, Kuwait
| | - Ehab El-Anany
- Section of Child Neurology, Department of Pediatrics, Al-adan Hospital, Riqqa, Kuwait
| | | | | | - Colette Gaba
- Department of Pediatrics, Bon Secours Mercy Health, Toledo, OH 43608, USA
| | - Ateeq Haseeb
- Mercy Children’s Hospital, Toledo, OH 43608, USA
| | - Amal M Alhashem
- Division of Medical Genetic and Metabolic Medicine, Department of Pediatrics, Prince Sultan Medical Military City, Riyadh, Saudi Arabia
| | - Enam Danish
- Department of Ophthalmology, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | | | | | - Alaa A Subhi
- Neurosciences Department, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | | | | | - Monisha Sebastin
- Albert Einstein College of Medicine and the Children's Hospital at Montefiore, Bronx, New York 10467, USA
- Division of Genetics, Department of Pediatrics, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York, 10467, USA
| | - Margo Sheck Breilyn
- Albert Einstein College of Medicine and the Children's Hospital at Montefiore, Bronx, New York 10467, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Susan Duberstein
- Isabelle Rapin Division of Child Neurology in the Saul R Korey Department of Neurology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Mohamed S Abdel-Hamid
- Department of Medical Molecular Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Tadahiro Mitani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratory, Houston, TX 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zeynep Coban Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genetics Center, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jenny C Taylor
- NIHR Oxford Biomedical Research Centre, Oxford OX4 2PG, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Khalid A Fakhro
- Department of Human Genetics, Sidra Medicine, Doha 26999, Qatar
- Department of Genetic Medicine, Weill Cornell Medical College, Doha, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha 34110, Qatar
| | - Jill V Hunter
- E.B. Singleton Department of Pediatric Radiology, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Radiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Texas Children's Hospital, Houston, TX 77030, USA
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Maha S Zaki
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Joseph G Gleeson
- Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, CA 92123, USA
| | - Reza Maroofian
- Department of Neuromuscular Disorders Institute of Neurology, University College London, Queen Square, London, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders Institute of Neurology, University College London, Queen Square, London, UK
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratory, Houston, TX 77030, USA
- Texas Children's Hospital, Houston, TX 77030, USA
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratory, Houston, TX 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
- Texas Children's Hospital, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence may also be addressed to: James R. Lupski, MD, PhD, DSc (hon) Department of Molecular and Human Genetics, Baylor College of Medicine One Baylor Plaza, Room 604B, Houston, TX 77030, USA E-mail:
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15
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Kovermann P, Kolobkova Y, Franzen A, Fahlke C. Mutations associated with epileptic encephalopathy modify EAAT2 anion channel function. Epilepsia 2021; 63:388-401. [PMID: 34961934 DOI: 10.1111/epi.17154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/09/2021] [Accepted: 12/09/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Mutations in the gene solute carrier family member 1A2 (SLC1A2) encoding the excitatory amino acid transporter 2 (EAAT2) are associated with severe forms of epileptic encephalopathy. EAAT2 is expressed in glial cells and presynaptic nerve terminals and represents the main l-glutamate uptake carrier in the mammalian brain. It does not only function as a secondary active glutamate transporter, but also as an anion channel. How naturally occurring mutations affect these two transport functions of EAAT2 and how such alterations cause epilepsy is insufficiently understood. METHODS Here we studied the functional consequences of three disease-associated mutations, which predict amino acid exchanges p.Gly82Arg (G82R), p.Leu85Pro (L85P), and p.Pro289Arg (P289R), by heterologous expression in mammalian cells, biochemistry, confocal imaging, and whole-cell patch-clamp recordings of EAAT2 l-glutamate transport and anion current. RESULTS G82R and L85P exchange amino acid residues contribute to the formation of the EAAT anion pore. They enlarge the pore diameter sufficiently to permit the passage of l-glutamate and thus function as l-glutamate efflux pathways. The mutation P289R decreases l-glutamate uptake, but increases anion currents despite a lower membrane expression. SIGNIFICANCE l-glutamate permeability of the EAAT anion pore is an unexpected functional consequence of naturally occurring single amino acid substitutions. l-glutamate efflux through mutant EAAT2 anion channels will cause glutamate excitotoxicity and neuronal hyperexcitability in affected patients. Antagonists that selectively suppress the EAAT anion channel function could serve as therapeutic agents in the future.
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Affiliation(s)
- Peter Kovermann
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Yulia Kolobkova
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Arne Franzen
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
| | - Christoph Fahlke
- Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Institute of Biological Information Processing, Jülich, Germany
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16
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Iodice A, Giannelli C, Soli F, Riva A, Striano P. Myoclonic epilepsy of infancy related to YWHAG gene mutation: towards a better phenotypic characterization. Seizure 2021; 94:161-164. [PMID: 34915349 DOI: 10.1016/j.seizure.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 10/19/2022] Open
Affiliation(s)
- Alessandro Iodice
- Child Neuropsychiatry Unit, S. Chiara Hospital, APSS, Trento, Italy.
| | | | - Fiorenza Soli
- Medical Genetic Unit, S. Chiara Hospital APSS, Trento, Italy
| | - Antonella Riva
- Paediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Pasquale Striano
- Paediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
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17
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Dick K, Pattang A, Hooker J, Nissan N, Sadowski M, Barnes B, Tan LH, Burnside D, Phanse S, Aoki H, Babu M, Dehne F, Golshani A, Cober ER, Green JR, Samanfar B. Human-Soybean Allergies: Elucidation of the Seed Proteome and Comprehensive Protein-Protein Interaction Prediction. J Proteome Res 2021; 20:4925-4947. [PMID: 34582199 DOI: 10.1021/acs.jproteome.1c00138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The soybean crop, Glycine max (L.) Merr., is consumed by humans, Homo sapiens, worldwide. While the respective bodies of literature and -omics data for each of these organisms are extensive, comparatively few studies investigate the molecular biological processes occurring between the two. We are interested in elucidating the network of protein-protein interactions (PPIs) involved in human-soybean allergies. To this end, we leverage state-of-the-art sequence-based PPI predictors amenable to predicting the enormous comprehensive interactome between human and soybean. A network-based analytical approach is proposed, leveraging similar interaction profiles to identify candidate allergens and proteins involved in the allergy response. Interestingly, the predicted interactome can be explored from two complementary perspectives: which soybean proteins are predicted to interact with specific human proteins and which human proteins are predicted to interact with specific soybean proteins. A total of eight proteins (six specific to the human proteome and two to the soy proteome) have been identified and supported by the literature to be involved in human health, specifically related to immunological and neurological pathways. This study, beyond generating the most comprehensive human-soybean interactome to date, elucidated a soybean seed interactome and identified several proteins putatively consequential to human health.
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Affiliation(s)
- Kevin Dick
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Arezo Pattang
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Julia Hooker
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Nour Nissan
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Michael Sadowski
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Bradley Barnes
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Le Hoa Tan
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Daniel Burnside
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Sadhna Phanse
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2
| | - Hiroyuki Aoki
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2
| | - Frank Dehne
- School of Computer Science, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Ashkan Golshani
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Elroy R Cober
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
| | - James R Green
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Bahram Samanfar
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Ontario, Canada K1A 0C6
- Department of Biology and Institute of Biochemistry, and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
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18
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Hotz AL, Jamali A, Rieser NN, Niklaus S, Aydin E, Myren‐Svelstad S, Lalla L, Jurisch‐Yaksi N, Yaksi E, Neuhauss SCF. Loss of glutamate transporter eaat2a leads to aberrant neuronal excitability, recurrent epileptic seizures, and basal hypoactivity. Glia 2021; 70:196-214. [PMID: 34716961 PMCID: PMC9297858 DOI: 10.1002/glia.24106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022]
Abstract
Astroglial excitatory amino acid transporter 2 (EAAT2, GLT‐1, and SLC1A2) regulates the duration and extent of neuronal excitation by removing glutamate from the synaptic cleft. Hence, an impairment in EAAT2 function could lead to an imbalanced brain network excitability. Here, we investigated the functional alterations of neuronal and astroglial networks associated with the loss of function in the astroglia predominant eaat2a gene in zebrafish. We observed that eaat2a−/− mutant zebrafish larvae display recurrent spontaneous and light‐induced seizures in neurons and astroglia, which coincide with an abrupt increase in extracellular glutamate levels. In stark contrast to this hyperexcitability, basal neuronal and astroglial activity was surprisingly reduced in eaat2a−/− mutant animals, which manifested in decreased overall locomotion. Our results reveal an essential and mechanistic contribution of EAAT2a in balancing brain excitability, and its direct link to epileptic seizures.
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Affiliation(s)
- Adriana L. Hotz
- Department of Molecular Life SciencesUniversity of ZurichZurichSwitzerland
- Life Science Zürich Graduate School ‐ NeuroscienceUniversity of Zurich and ETH ZurichZurichSwitzerland
| | - Ahmed Jamali
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
| | - Nicolas N. Rieser
- Department of Molecular Life SciencesUniversity of ZurichZurichSwitzerland
- Life Science Zürich Graduate School ‐ NeuroscienceUniversity of Zurich and ETH ZurichZurichSwitzerland
| | - Stephanie Niklaus
- Department of Molecular Life SciencesUniversity of ZurichZurichSwitzerland
- Present address:
EraCal TherapeuticsSchlierenSwitzerland
| | - Ecem Aydin
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
| | - Sverre Myren‐Svelstad
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
- Department of Neurology and Clinical NeurophysiologySt. Olav's University HospitalTrondheimNorway
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Laetitia Lalla
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
| | - Nathalie Jurisch‐Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
- Department of Neurology and Clinical NeurophysiologySt. Olav's University HospitalTrondheimNorway
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural ComputationFaculty of Medicine and Health Sciences, Norwegian University of Science and TechnologyTrondheimNorway
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19
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Qu Q, Wang J, Li G, Chen R, Qu S. The Conformationally Sensitive Spatial Distance Between the TM3-4 Loop and Transmembrane Segment 7 in the Glutamate Transporter Revealed by Paired-Cysteine Mutagenesis. Front Cell Dev Biol 2021; 9:737629. [PMID: 34621751 PMCID: PMC8490817 DOI: 10.3389/fcell.2021.737629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 08/25/2021] [Indexed: 11/23/2022] Open
Abstract
Excitatory amino acid transporters can maintain extracellular glutamate concentrations lower than neurotoxic levels by transferring neurotransmitters from the synaptic cleft into surrounding glial cells and neurons. Previous work regarding the structural studies of GltPh, GltTK, excitatory amino acid transporter 1 (EAAT1), EAAT3 and alanine serine cysteine transporter 2 described the transport mechanism of the glutamate transporter in depth. However, much remains unknown about the role of the loop between transmembrane segment 3 and 4 during transport. To probe the function of this loop in the transport cycle, we engineered a pair of cysteine residues between the TM3-TM4 loop and TM7 in cysteine-less EAAT2. Here, we show that the oxidative cross-linking reagent CuPh inhibits transport activity of the paired mutant L149C/M414C, whereas DTT inhibits the effect of CuPh on transport activity of L149C/M414C. Additionally, we show that the effect of cross-linking in the mutant is due to the formation of the disulfide bond within the molecules of EAAT2. Further, L-glutamate or KCl protect, and D,L-threo-β-benzyloxy-aspartate (TBOA) increases, CuPh-induced inhibition in the L149C/M414 mutant, suggesting that the L149C and M414C cysteines are closer or farther away in the outward- or inward-facing conformations, respectively. Together, our findings provide evidence that the distance between TM3-TM4 loop and TM7 alter when substrates are transported.
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Affiliation(s)
- Qi Qu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.,Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China
| | - Ji Wang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.,Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China
| | - Guiping Li
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Rongqing Chen
- Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Shaogang Qu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.,Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China
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20
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Green JL, Dos Santos WF, Fontana ACK. Role of glutamate excitotoxicity and glutamate transporter EAAT2 in epilepsy: Opportunities for novel therapeutics development. Biochem Pharmacol 2021; 193:114786. [PMID: 34571003 DOI: 10.1016/j.bcp.2021.114786] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/21/2022]
Abstract
Epilepsy is a complex neurological syndrome characterized by seizures resulting from neuronal hyperexcitability and sudden and synchronized bursts of electrical discharges. Impaired astrocyte function that results in glutamate excitotoxicity has been recognized to play a key role in the pathogenesis of epilepsy. While there are 26 drugs marketed as anti-epileptic drugs no current treatments are disease modifying as they only suppress seizures rather than the development and progression of epilepsy. Excitatory amino acid transporters (EAATs) are critical for maintaining low extracellular glutamate concentrations and preventing excitotoxicity. When extracellular glutamate concentrations rise to abnormal levels, glutamate receptor overactivation and the subsequent excessive influx of calcium into the post-synaptic neuron can trigger cell death pathways. In this review we discuss targeting EAAT2, the predominant glutamate transporter in the CNS, as a promising approach for developing therapies for epilepsy. EAAT2 upregulation via transcriptional and translational regulation has proven successful in vivo in reducing spontaneous recurrent seizures and offering neuroprotective effects. Another approach to regulate EAAT2 activity is through positive allosteric modulation (PAM). Novel PAMs of EAAT2 have recently been identified and are under development, representing a promising approach for the advance of novel therapeutics for epilepsy.
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Affiliation(s)
- Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, United States
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21
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Magalhães PHM, Moraes HT, Athie MCP, Secolin R, Lopes-Cendes I. New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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22
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Pavinato L, Nematian-Ardestani E, Zonta A, De Rubeis S, Buxbaum J, Mancini C, Bruselles A, Tartaglia M, Pessia M, Tucker SJ, D’Adamo MC, Brusco A. KCNK18 Biallelic Variants Associated with Intellectual Disability and Neurodevelopmental Disorders Alter TRESK Channel Activity. Int J Mol Sci 2021; 22:ijms22116064. [PMID: 34199759 PMCID: PMC8200030 DOI: 10.3390/ijms22116064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/30/2021] [Accepted: 06/01/2021] [Indexed: 12/19/2022] Open
Abstract
The TWIK-related spinal cord potassium channel (TRESK) is encoded by KCNK18, and variants in this gene have previously been associated with susceptibility to familial migraine with aura (MIM #613656). A single amino acid substitution in the same protein, p.Trp101Arg, has also been associated with intellectual disability (ID), opening the possibility that variants in this gene might be involved in different disorders. Here, we report the identification of KCNK18 biallelic missense variants (p.Tyr163Asp and p.Ser252Leu) in a family characterized by three siblings affected by mild-to-moderate ID, autism spectrum disorder (ASD) and other neurodevelopment-related features. Functional characterization of the variants alone or in combination showed impaired channel activity. Interestingly, Ser252 is an important regulatory site of TRESK, suggesting that alteration of this residue could lead to additive downstream effects. The functional relevance of these mutations and the observed co-segregation in all the affected members of the family expand the clinical variability associated with altered TRESK function and provide further insight into the relationship between altered function of this ion channel and human disease.
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Affiliation(s)
- Lisa Pavinato
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy;
- Center for Molecular Medicine Cologne, Institute of Human Genetics, University of Cologne, 50931 Cologne, Germany
| | - Ehsan Nematian-Ardestani
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD-2080 Msida, Malta; (E.N.-A.); (M.P.)
| | - Andrea Zonta
- Unit of Medical Genetics, “Città della Salute e della Scienza” University Hospital, 10126 Turin, Italy;
| | - Silvia De Rubeis
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (S.D.R.); (J.B.)
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Joseph Buxbaum
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (S.D.R.); (J.B.)
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cecilia Mancini
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00165 Rome, Italy; (C.M.); (M.T.)
| | - Alessandro Bruselles
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00165 Rome, Italy; (C.M.); (M.T.)
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD-2080 Msida, Malta; (E.N.-A.); (M.P.)
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Stephen J. Tucker
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 4BH, UK;
| | - Maria Cristina D’Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD-2080 Msida, Malta; (E.N.-A.); (M.P.)
- Correspondence: (M.C.D.); (A.B.)
| | - Alfredo Brusco
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy;
- Unit of Medical Genetics, “Città della Salute e della Scienza” University Hospital, 10126 Turin, Italy;
- Correspondence: (M.C.D.); (A.B.)
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23
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Ye XG, Liu ZG, Wang J, Dai JM, Qiao PX, Gao PM, Liao WP. YWHAG Mutations Cause Childhood Myoclonic Epilepsy and Febrile Seizures: Molecular Sub-regional Effect and Mechanism. Front Genet 2021; 12:632466. [PMID: 33767733 PMCID: PMC7985244 DOI: 10.3389/fgene.2021.632466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/15/2021] [Indexed: 01/27/2023] Open
Abstract
YWHAG, which encodes an adapter protein 14-3-3γ, is highly expressed in the brain and regulates a diverse range of cell signaling pathways. Previously, eight YWHAG mutations have been identified in patients with epileptic encephalopathy (EE). In this study, using trios-based whole exome sequencing, we identified two novel YWHAG mutations in two unrelated families with childhood myoclonic epilepsy and/or febrile seizures (FS). The identified mutations included a heterozygous truncating mutation (c.124C>T/p.Arg42Ter) and a de novo missense mutation (c.373A>G/p.Lys125Glu). The two probands experienced daily myoclonic seizures that were recorded with ictal generalized polyspike-slow waves, but became seizure-free with simple valproate treatment. The other affected individuals presented FS. The truncating mutation was identified in the family with six individuals of mild phenotype, suggesting that YWHAG mutations of haploinsufficiency are relatively less pathogenic. Analysis on all missense mutations showed that nine mutations were located within 14-3-3γ binding groove and another mutation was located at residues critical for dimerization, indicating a molecular sub-regional effect. Mutation Arg132Cys, which was identified recurrently in five patients with EE, would have the strongest influence on binding affinity. 14-3-3γ dimers supports target proteins activity. Thus, a heterozygous missense mutation would lead to majority dimers being mutants; whereas a heterozygous truncating mutation would lead to only decreasing the number of wild-type dimer, being one of the explanations for phenotypical variation. This study suggests that YWHAG is potentially a candidate pathogenic gene of childhood myoclonic epilepsy and FS. The spectrum of epilepsy caused by YWHAG mutations potentially range from mild myoclonic epilepsy and FS to severe EE.
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Affiliation(s)
- Xing-Guang Ye
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Zhi-Gang Liu
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China.,Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jie Wang
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jie-Min Dai
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Pei-Xiu Qiao
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Ping-Ming Gao
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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24
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Mai D, Chen R, Wang J, Zheng J, Zhang X, Qu S. Critical amino acids in the TM2 of EAAT2 are essential for membrane-bound localization, substrate binding, transporter function and anion currents. J Cell Mol Med 2021; 25:2530-2548. [PMID: 33523598 PMCID: PMC7933967 DOI: 10.1111/jcmm.16212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 11/12/2020] [Accepted: 11/28/2020] [Indexed: 12/25/2022] Open
Abstract
Excitatory amino acid transporter 2 (EAAT2), the gene of which is known as solute carrier family 1 member 2 (SLC1A2), is an important membrane-bound transporter that mediates approximately 90% of the transport and clearance of l-glutamate at synapses in the central nervous system (CNS). Transmembrane domain 2 (TM2) of EAAT2 is close to hairpin loop 2 (HP2) and far away from HP1 in the inward-facing conformation. In the present study, 14 crucial amino acid residues of TM2 were identified via alanine-scanning mutations. Further analysis in EAAT2-transfected HeLa cells in vitro showed that alanine substitutions of these residues resulted in a decrease in the efficiency of trafficking/targeting to the plasma membrane and/or reduced functionality of membrane-bound, which resulted in impaired transporter activity. After additional mutations, the transporter activities of some alanine-substitution mutants recovered. Specifically, the P95A mutant decreased EAAT2-associated anion currents. The Michaelis constant (Km ) values of the mutant proteins L85A, L92A and L101A were increased significantly, whereas R87 and P95A were decreased significantly, indicating that the mutations L85A, L92A and L101A reduced the affinity of the transporter and the substrate, whereas R87A and P95A enhanced this affinity. The maximum velocity (Vmax) values of all 14 alanine mutant proteins were decreased significantly, indicating that all these mutations reduced the substrate transport rate. These results suggest that critical residues in TM2 affect not only the protein expression and membrane-bound localization of EAAT2, but also its interactions with substrates. Additionally, our findings elucidate that the P95A mutant decreased EAAT2-related anion currents. Our results indicate that the TM2 of EAAT2 plays a vital role in the transport process. The key residues in TM2 affect protein expression in the membrane, substrate transport and the anion currents of EAAT2.
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Affiliation(s)
- Dongmei Mai
- Department of NeurologyNanfang HospitalSouthern Medical UniversityGuangzhouChina
- Key Laboratory of Mental Health of the Ministry of EducationSouthern Medical UniversityGuangzhouChina
- Guangdong‐Hong Kong‐Macao Greater Bay Area Center for Brain Science and Brain‐Inspired IntelligenceGuangzhouChina
| | - Rongqing Chen
- Department of NeurobiologySchool of Basic Medical SciencesSouthern Medical UniversityGuangzhouChina
| | - Ji Wang
- Department of NeurologyNanfang HospitalSouthern Medical UniversityGuangzhouChina
- Key Laboratory of Mental Health of the Ministry of EducationSouthern Medical UniversityGuangzhouChina
- Guangdong‐Hong Kong‐Macao Greater Bay Area Center for Brain Science and Brain‐Inspired IntelligenceGuangzhouChina
| | - Jiawei Zheng
- Department of NeurobiologySchool of Basic Medical SciencesSouthern Medical UniversityGuangzhouChina
| | - Xiuping Zhang
- Teaching Center of Experimental MedicineSchool of Basic Medical SciencesSouthern Medical UniversityGuangzhouChina
| | - Shaogang Qu
- Department of NeurologyNanfang HospitalSouthern Medical UniversityGuangzhouChina
- Key Laboratory of Mental Health of the Ministry of EducationSouthern Medical UniversityGuangzhouChina
- Guangdong‐Hong Kong‐Macao Greater Bay Area Center for Brain Science and Brain‐Inspired IntelligenceGuangzhouChina
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25
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Sedláčková L, Štěrbová K, Vlčková M, Maulisová A, Laššuthová P. A novel variant in YWHAG further supports phenotype of developmental and epileptic encephalopathy. Am J Med Genet A 2021; 185:1363-1365. [PMID: 33590706 DOI: 10.1002/ajmg.a.62116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Lucie Sedláčková
- Neurogenetic Laboratory, Department of Pediatric Neurology, Second Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Katalin Štěrbová
- Department of Pediatric Neurology, Second Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Markéta Vlčková
- Biology and Medical Genetics, Second Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Alice Maulisová
- Department of Psychology, Second Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Petra Laššuthová
- Neurogenetic Laboratory, Department of Pediatric Neurology, Second Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
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26
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Alleva C, Machtens JP, Kortzak D, Weyand I, Fahlke C. Molecular Basis of Coupled Transport and Anion Conduction in Excitatory Amino Acid Transporters. Neurochem Res 2021; 47:9-22. [PMID: 33587237 PMCID: PMC8763778 DOI: 10.1007/s11064-021-03252-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/15/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. After its release from presynaptic nerve terminals, glutamate is quickly removed from the synaptic cleft by excitatory amino acid transporters (EAATs) 1–5, a subfamily of glutamate transporters. The five proteins utilize a complex transport stoichiometry that couples glutamate transport to the symport of three Na+ ions and one H+ in exchange with one K+ to accumulate glutamate against up to 106-fold concentration gradients. They are also anion-selective channels that open and close during transitions along the glutamate transport cycle. EAATs belong to a larger family of secondary-active transporters, the SLC1 family, which also includes purely Na+- or H+-coupled prokaryotic transporters and Na+-dependent neutral amino acid exchangers. In recent years, molecular cloning, heterologous expression, cellular electrophysiology, fluorescence spectroscopy, structural approaches, and molecular simulations have uncovered the molecular mechanisms of coupled transport, substrate selectivity, and anion conduction in EAAT glutamate transporters. Here we review recent findings on EAAT transport mechanisms, with special emphasis on the highly conserved hairpin 2 gate, which has emerged as the central processing unit in many of these functions.
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Affiliation(s)
- Claudia Alleva
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Jan-Philipp Machtens
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany.,Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
| | - Daniel Kortzak
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Ingo Weyand
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Christoph Fahlke
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany.
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Sadler B, Wilborn J, Antunes L, Kuensting T, Hale AT, Gannon SR, McCall K, Cruchaga C, Harms M, Voisin N, Reymond A, Cappuccio G, Brunetti-Pierri N, Tartaglia M, Niceta M, Leoni C, Zampino G, Ashley-Koch A, Urbizu A, Garrett ME, Soldano K, Macaya A, Conrad D, Strahle J, Dobbs MB, Turner TN, Shannon CN, Brockmeyer D, Limbrick DD, Gurnett CA, Haller G. Rare and de novo coding variants in chromodomain genes in Chiari I malformation. Am J Hum Genet 2021; 108:100-114. [PMID: 33352116 DOI: 10.1016/j.ajhg.2020.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
Chiari I malformation (CM1), the displacement of the cerebellum through the foramen magnum into the spinal canal, is one of the most common pediatric neurological conditions. Individuals with CM1 can present with neurological symptoms, including severe headaches and sensory or motor deficits, often as a consequence of brainstem compression or syringomyelia (SM). We conducted whole-exome sequencing (WES) on 668 CM1 probands and 232 family members and performed gene-burden and de novo enrichment analyses. A significant enrichment of rare and de novo non-synonymous variants in chromodomain (CHD) genes was observed among individuals with CM1 (combined p = 2.4 × 10-10), including 3 de novo loss-of-function variants in CHD8 (LOF enrichment p = 1.9 × 10-10) and a significant burden of rare transmitted variants in CHD3 (p = 1.8 × 10-6). Overall, individuals with CM1 were found to have significantly increased head circumference (p = 2.6 × 10-9), with many harboring CHD rare variants having macrocephaly. Finally, haploinsufficiency for chd8 in zebrafish led to macrocephaly and posterior hindbrain displacement reminiscent of CM1. These results implicate chromodomain genes and excessive brain growth in CM1 pathogenesis.
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Abstract
This review explores how different classes of drugs, including those with therapeutic and abuse potential, alter brain functions and behavior via the epigenome. Epigenetics, in its simplest interpretation, is the study of the regulation of a genes' transcriptional potential. The epigenome is established during development but is malleable throughout life by a wide variety of drugs, with both clinical utility and abuse potential. An epigenetic effect can be central to the drug's therapeutic or abuse potential, or it can be independent from the main effect but nevertheless produce beneficial or adverse side effects. Here, I discuss the various epigenetic effects of main pharmacological drug classes, including antidepressants, antiepileptics, and drugs of abuse.
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Affiliation(s)
- Miklos Toth
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA;
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29
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Yaksi E, Jamali A, Diaz Verdugo C, Jurisch-Yaksi N. Past, present and future of zebrafish in epilepsy research. FEBS J 2021; 288:7243-7255. [PMID: 33394550 DOI: 10.1111/febs.15694] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/17/2020] [Accepted: 12/31/2020] [Indexed: 12/17/2022]
Abstract
Animal models contribute greatly to our understanding of brain development and function as well as its dysfunction in neurological diseases. Epilepsy research is a very good example of how animal models can provide us with a mechanistic understanding of the genes, molecules, and pathophysiological processes involved in disease. Over the course of the last two decades, zebrafish came in as a new player in epilepsy research, with an expanding number of laboratories using this animal to understand epilepsy and to discover new strategies for preventing seizures. Yet, zebrafish as a model offers a lot more for epilepsy research. In this viewpoint, we aim to highlight some key contributions of zebrafish to epilepsy research, and we want to emphasize the great untapped potential of this animal model for expanding these contributions. We hope that our suggestions will trigger further discussions between clinicians and researchers with a common goal to understand and cure epilepsy.
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Affiliation(s)
- Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ahmed Jamali
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway
| | - Carmen Diaz Verdugo
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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30
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Stern T, Orenstein N, Fellner A, Lev-El Halabi N, Shuldiner AR, Gonzaga-Jauregui C, Lidzbarsky G, Basel-Salmon L, Goldberg-Stern H. Epilepsy and electroencephalogram evolution in YWHAG gene mutation: A new phenotype and review of the literature. Am J Med Genet A 2021; 185:901-908. [PMID: 33393734 DOI: 10.1002/ajmg.a.62026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/09/2020] [Accepted: 11/12/2020] [Indexed: 02/02/2023]
Abstract
A male patient with a de novo mutation in the YWHAG gene and mild phenotype is presented. He had normal delivery and normal development, with normal speech and social milestones. At the age of 9 months, myoclonic seizures started, with generalized epileptiform discharges. The child responded well to levetiracetam monotherapy with complete seizure resolution. Levetiracetam was stopped and he remained seizure-free for 10 months. His development was appropriate for age according to psychological evaluation and he attended a regular kindergarten. At the age of approximately 4 years, the seizures reappeared with different semiology of staring with eye blinking. Electroencephalogram (EEG) showed multifocal spikes. Brain magnetic resonance imaging did not reveal any structural abnormality. Genetic analysis revealed a de novo likely pathogenic missense variant in the YWHAG gene (c.619G>A p.Glu207Lys). We compared our case to the other cases published in the literature. Our case is unique in its seizure semiology and evolution of EEG. Moreover, in contrast to our case, the majority of cases described in the literature have dysmorphism and intellectual disability or autistic spectrum disorder. This report emphasizes the phenotypic heterogeneity of YWHAG mutation as is the case in other developmental encephalopathies.
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Affiliation(s)
- Tomer Stern
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Naama Orenstein
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Pediatric Genetics Clinic, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Avi Fellner
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.,Department of Neurology, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel
| | - Noa Lev-El Halabi
- The Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel
| | | | | | - Gabriel Lidzbarsky
- Pediatric Genetics Clinic, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Lina Basel-Salmon
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.,Department of Neurology, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.,Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Hadassa Goldberg-Stern
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Epilepsy Center, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
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Kim SY, Jang SS, Kim H, Hwang H, Choi JE, Chae JH, Kim KJ, Lim BC. Genetic diagnosis of infantile-onset epilepsy in the clinic: Application of whole-exome sequencing following epilepsy gene panel testing. Clin Genet 2021; 99:418-424. [PMID: 33349918 DOI: 10.1111/cge.13903] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/02/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022]
Abstract
This study aimed to evaluate the clinical utility of whole-exome sequencing in a group of infantile-onset epilepsy patients who tested negative for epilepsy using a gene panel test. Whole-exome sequencing was performed on 59 patients who tested negative on customized epilepsy gene panel testing. We identified eight pathogenic or likely pathogenic sequence variants in eight different genes (FARS2, YWHAG, KCNC1, DYRK1A, SMC1A, PIGA, OGT, and FGF12), one pathogenic structural variant (8.6 Mb-sized deletion on chromosome X [140 994 419-149 630 805]), and three putative low-frequency mosaic variants from three different genes (GABBR2, MTOR, and CUX1). Subsequent whole-exome sequencing revealed an additional 8% of diagnostic yield with genetic confirmation of epilepsy in 55.4% (62/112) of our cohort. Three genes (YWHAG, KCNC1, and FGF12) were identified as epilepsy-causing genes after the original gene panel was designed. The others were initially linked with mitochondrial encephalopathy or different neurodevelopmental disorders, although an epilepsy phenotype was listed as one of the clinical features. Application of whole-exome sequencing following epilepsy gene panel testing provided 8% of additional diagnostic yield in an infantile-onset epilepsy cohort. Whole-exome sequencing could provide an opportunity to reanalyze newly recognized epilepsy-linked genes without updating the gene panel design.
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Affiliation(s)
- Soo Yeon Kim
- Department of Pediatrics, Pediatric Neuroscience Center, Seoul National University Children's Hospital, Seoul National University Children's Hospital, Seoul, South Korea.,Rare Diseases Center, Seoul National University Hospital, Seoul, South Korea
| | - Se Song Jang
- Department of Pediatrics, Pediatric Neuroscience Center, Seoul National University Children's Hospital, Seoul National University Children's Hospital, Seoul, South Korea
| | - Hunmin Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, South Korea
| | - Hee Hwang
- Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, South Korea
| | - Ji Eun Choi
- Department of Pediatrics, Seoul National University Boramae Medical Center, Seoul, South Korea
| | - Jong-Hee Chae
- Department of Pediatrics, Pediatric Neuroscience Center, Seoul National University Children's Hospital, Seoul National University Children's Hospital, Seoul, South Korea.,Rare Diseases Center, Seoul National University Hospital, Seoul, South Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
| | - Ki Joong Kim
- Department of Pediatrics, Pediatric Neuroscience Center, Seoul National University Children's Hospital, Seoul National University Children's Hospital, Seoul, South Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
| | - Byung Chan Lim
- Department of Pediatrics, Pediatric Neuroscience Center, Seoul National University Children's Hospital, Seoul National University Children's Hospital, Seoul, South Korea.,Rare Diseases Center, Seoul National University Hospital, Seoul, South Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
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32
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Bhat S, El-Kasaby A, Freissmuth M, Sucic S. Functional and Biochemical Consequences of Disease Variants in Neurotransmitter Transporters: A Special Emphasis on Folding and Trafficking Deficits. Pharmacol Ther 2020; 222:107785. [PMID: 33310157 PMCID: PMC7612411 DOI: 10.1016/j.pharmthera.2020.107785] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
Neurotransmitters, such as γ-aminobutyric acid, glutamate, acetyl choline, glycine and the monoamines, facilitate the crosstalk within the central nervous system. The designated neurotransmitter transporters (NTTs) both release and take up neurotransmitters to and from the synaptic cleft. NTT dysfunction can lead to severe pathophysiological consequences, e.g. epilepsy, intellectual disability, or Parkinson’s disease. Genetic point mutations in NTTs have recently been associated with the onset of various neurological disorders. Some of these mutations trigger folding defects in the NTT proteins. Correct folding is a prerequisite for the export of NTTs from the endoplasmic reticulum (ER) and the subsequent trafficking to their pertinent site of action, typically at the plasma membrane. Recent studies have uncovered some of the key features in the molecular machinery responsible for transporter protein folding, e.g., the role of heat shock proteins in fine-tuning the ER quality control mechanisms in cells. The therapeutic significance of understanding these events is apparent from the rising number of reports, which directly link different pathological conditions to NTT misfolding. For instance, folding-deficient variants of the human transporters for dopamine or GABA lead to infantile parkinsonism/dystonia and epilepsy, respectively. From a therapeutic point of view, some folding-deficient NTTs are amenable to functional rescue by small molecules, known as chemical and pharmacological chaperones.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Ali El-Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria.
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Lapato AS, Thompson SM, Parra K, Tiwari-Woodruff SK. Astrocyte Glutamate Uptake and Water Homeostasis Are Dysregulated in the Hippocampus of Multiple Sclerosis Patients With Seizures. ASN Neuro 2020; 12:1759091420979604. [PMID: 33297722 PMCID: PMC7734542 DOI: 10.1177/1759091420979604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
While seizure disorders are more prevalent among multiple sclerosis (MS) patients than the population overall and prognosticate earlier death & disability, their etiology remains unclear. Translational data indicate perturbed expression of astrocytic molecules contributing to homeostatic neuronal excitability, including water channels (AQP4) and synaptic glutamate transporters (EAAT2), in a mouse model of MS with seizures (MS+S). However, astrocytes in MS+S have not been examined. To assess the translational relevance of astrocyte dysfunction observed in a mouse model of MS+S, demyelinated lesion burden, astrogliosis, and astrocytic biomarkers (AQP4/EAAT2/ connexin-CX43) were evaluated by immunohistochemistry in postmortem hippocampi from MS & MS+S donors. Lesion burden was comparable in MS & MS+S cohorts, but astrogliosis was elevated in MS+S CA1 with a concomitant decrease in EAAT2 signal intensity. AQP4 signal declined in MS+S CA1 & CA3 with a loss of perivascular AQP4 in CA1. CX43 expression was increased in CA3. Together, these data suggest that hippocampal astrocytes from MS+S patients display regional differences in expression of molecules associated with glutamate buffering and water homeostasis that could exacerbate neuronal hyperexcitability. Importantly, mislocalization of CA1 perivascular AQP4 seen in MS+S is analogous to epileptic hippocampi without a history of MS, suggesting convergent pathophysiology. Furthermore, as neuropathology was concentrated in MS+S CA1, future study is warranted to determine the pathophysiology driving regional differences in glial function in the context of seizures during demyelinating disease.
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Affiliation(s)
- Andrew S Lapato
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States.,Center for Glial-Neuronal Interaction, UCR School of Medicine, Riverside, California, United States
| | - Sarah M Thompson
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States
| | - Karen Parra
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States.,Center for Glial-Neuronal Interaction, UCR School of Medicine, Riverside, California, United States.,Department of Neuroscience, UCR School of Medicine, Riverside, California, United States
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34
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Zaitsev AV, Smolensky IV, Jorratt P, Ovsepian SV. Neurobiology, Functions, and Relevance of Excitatory Amino Acid Transporters (EAATs) to Treatment of Refractory Epilepsy. CNS Drugs 2020; 34:1089-103. [PMID: 32926322 DOI: 10.1007/s40263-020-00764-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epilepsy is one of the most prevalent and devastating neurological disorders characterized by episodes of unusual sensations, loss of awareness, and reoccurring seizures. The frequency and intensity of epileptic fits can vary to a great degree, with almost a third of all cases resistant to available therapies. At present, there is a major unmet need for effective and specific therapeutic intervention. Impairments of the exquisite balance between excitatory and inhibitory synaptic processes in the brain are considered key in the onset and pathophysiology of the disease. As the primary excitatory neurotransmitter in the central nervous system, glutamate has been implicated in the process, with the glutamatergic system holding center stage in the pathobiology as well as in developing disease-modifying therapies. Emerging data pinpoint impairments of glutamate clearance as one of the key causative factors in drug-resistant disease forms. Reinstatement of glutamate homeostasis using pharmacological and genetic modulation of glutamate clearance is therefore considered to be of major translational relevance. In this article, we review the neurobiological and clinical evidence suggesting complex aberrations in the activity and functions of excitatory amino acid transporters (EAATs) in epilepsy, with knock-on effects on glutamate homeostasis as a leading cause for the development of refractory forms. We consider the emerging data on pharmacological and genetic manipulations of EAATs, with reference to seizures and glutamate dyshomeostasis, and review their fundamental and translational relevance. We discuss the most recent advances in the EAATs research in human and animal models, along with numerous questions that remain open for debate and critical appraisal. Contrary to the widely held view on EAATs as a promising therapeutic target for management of refractory epilepsy as well as other neurological and psychiatric conditions related to glutamatergic hyperactivity and glutamate-induced cytotoxicity, we stress that the true relevance of EAAT2 as a target for medical intervention remains to be fully appreciated and verified. Despite decades of research, the emerging properties and functional characteristics of glutamate transporters and their relationship with neurophysiological and behavioral correlates of epilepsy challenge the current perception of this disease and fit unambiguously in neither EAATs functional deficit nor in reversal models. We stress the pressing need for new approaches and models for research and restoration of the physiological activity of glutamate transporters and synaptic transmission to achieve much needed therapeutic effects. The complex mechanism of EAATs regulation by multiple factors, including changes in the electrochemical environment and ionic gradients related to epileptic hyperactivity, impose major therapeutic challenges. As a final note, we consider the evolving views and present a cautious perspective on the key areas of future progress in the field towards better management and treatment of refractory disease forms.
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Abstract
14-3-3 proteins are mostly expressed in the brain and are closely involved in numerous brain functions and various brain disorders. Among the isotypes of the 14-3-3 proteins, 14-3-3γ is mainly expressed in neurons and is highly produced during brain development, which could indicate that it has a significance in neural development. Furthermore, the distinctive levels of temporally and locally regulated 14-3-3γ expression in various brain disorders suggest that it could play a substantial role in brain plasticity of the diseased states. In this review, we introduce the various brain disorders reported to be involved with 14-3-3γ, and summarize the changes of 14-3-3γ expression in each brain disease. We also discuss the potential of 14-3-3γ for treatment and the importance of research on specific 14-3-3 isotypes for an effective therapeutic approach.
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Affiliation(s)
- Eunsil Cho
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
| | - Jae-Yong Park
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
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36
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Zhao M, Havrilla JM, Fang L, Chen Y, Peng J, Liu C, Wu C, Sarmady M, Botas P, Isla J, Lyon GJ, Weng C, Wang K. Phen2Gene: rapid phenotype-driven gene prioritization for rare diseases. NAR Genom Bioinform 2020; 2:lqaa032. [PMID: 32500119 PMCID: PMC7252576 DOI: 10.1093/nargab/lqaa032] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/10/2020] [Accepted: 04/28/2020] [Indexed: 02/07/2023] Open
Abstract
Human Phenotype Ontology (HPO) terms are increasingly used in diagnostic settings to aid in the characterization of patient phenotypes. The HPO annotation database is updated frequently and can provide detailed phenotype knowledge on various human diseases, and many HPO terms are now mapped to candidate causal genes with binary relationships. To further improve the genetic diagnosis of rare diseases, we incorporated these HPO annotations, gene-disease databases and gene-gene databases in a probabilistic model to build a novel HPO-driven gene prioritization tool, Phen2Gene. Phen2Gene accesses a database built upon this information called the HPO2Gene Knowledgebase (H2GKB), which provides weighted and ranked gene lists for every HPO term. Phen2Gene is then able to access the H2GKB for patient-specific lists of HPO terms or PhenoPacket descriptions supported by GA4GH (http://phenopackets.org/), calculate a prioritized gene list based on a probabilistic model and output gene-disease relationships with great accuracy. Phen2Gene outperforms existing gene prioritization tools in speed and acts as a real-time phenotype-driven gene prioritization tool to aid the clinical diagnosis of rare undiagnosed diseases. In addition to a command line tool released under the MIT license (https://github.com/WGLab/Phen2Gene), we also developed a web server and web service (https://phen2gene.wglab.org/) for running the tool via web interface or RESTful API queries. Finally, we have curated a large amount of benchmarking data for phenotype-to-gene tools involving 197 patients across 76 scientific articles and 85 patients' de-identified HPO term data from the Children's Hospital of Philadelphia.
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Affiliation(s)
- Mengge Zhao
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - James M Havrilla
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Li Fang
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ying Chen
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jacqueline Peng
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cong Liu
- Department of Biomedical Informatics, Columbia University Medical Center, New York, NY 10032, USA
| | - Chao Wu
- Division of Genomic Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Mahdi Sarmady
- Division of Genomic Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Pablo Botas
- Foundation 29, Pozuelo de Alarcon, 28223 Madrid, Spain
| | - Julián Isla
- Foundation 29, Pozuelo de Alarcon, 28223 Madrid, Spain.,Dravet Syndrome European Federation, 29200 Brest, France
| | - Gholson J Lyon
- Institute for Basic Research in Developmental Disabilities (IBR), Staten Island, NY 10314, USA
| | - Chunhua Weng
- Department of Biomedical Informatics, Columbia University Medical Center, New York, NY 10032, USA
| | - Kai Wang
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA. The expanding spectrum of movement disorders in genetic epilepsies. Dev Med Child Neurol 2020; 62:178-191. [PMID: 31784983 DOI: 10.1111/dmcn.14407] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 12/27/2022]
Abstract
An ever-increasing number of neurogenetic conditions presenting with both epilepsy and atypical movements are now recognized. These disorders within the 'genetic epilepsy-dyskinesia' spectrum are clinically and genetically heterogeneous. Increased clinical awareness is therefore necessary for a rational diagnostic approach. Furthermore, careful interpretation of genetic results is key to establishing the correct diagnosis and initiating disease-specific management strategies in a timely fashion. In this review we describe the spectrum of movement disorders associated with genetically determined epilepsies. We also propose diagnostic strategies and putative pathogenic mechanisms causing these complex syndromes associated with both seizures and atypical motor control. WHAT THIS PAPER ADDS: Implicated genes encode proteins with very diverse functions. Pathophysiological mechanisms by which epilepsy and movement disorder phenotypes manifest are often not clear. Early diagnosis of treatable disorders is essential and next generation sequencing may be required.
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Affiliation(s)
- Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Federica Rachele Danti
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Robert Spaull
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Amy Mctague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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38
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Kanani F, Titheradge H, Cooper N, Elmslie F, Lees MM, Juusola J, Pisani L, McKenna C, Mignot C, Valence S, Keren B, Lachlan K, Balasubramanian M. Expanding the genotype-phenotype correlation of de novo heterozygous missense variants in YWHAG as a cause of developmental and epileptic encephalopathy. Am J Med Genet A 2020; 182:713-720. [PMID: 31926053 DOI: 10.1002/ajmg.a.61483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/20/2019] [Accepted: 12/27/2019] [Indexed: 01/19/2023]
Abstract
Developmental and Epileptic encephalopathies (DEE) describe heterogeneous epilepsy syndromes, characterized by early-onset, refractory seizures and developmental delay (DD). Several DEE associated genes have been reported. With increased access to whole exome sequencing (WES), new candidate genes are being identified although there are fewer large cohort papers describing the clinical phenotype in such patients. We describe 6 unreported individuals and provide updated information on an additional previously reported individual with heterozygous de novo missense variants in YWHAG. We describe a syndromal phenotype, report 5 novel, and a recurrent p.Arg132Cys YWHAG variant and compare developmental trajectory and treatment strategies in this cohort. We provide further evidence of causality in YWHAG variants. WES was performed in five patients via Deciphering Developmental Disorders Study and the remaining two were identified via Genematcher and AnnEX databases. De novo variants identified from exome data were validated using Sanger sequencing. Seven out of seven patients in the cohort have de novo, heterozygous missense variants in YWHAG including 2/7 patients with a recurrent c.394C > T, p.Arg132Cys variant; 1/7 has a second, pathogenic variant in STAG1. Characteristic features included: early-onset seizures, predominantly generalized tonic-clonic and absence type (7/7) with good response to standard anti-epileptic medications; moderate DD; Intellectual Disability (ID) (5/7) and Autism Spectrum Disorder (3/7). De novo YWHAG missense variants cause EE, characterized by early-onset epilepsy, ID and DD, supporting the hypothesis that YWHAG loss-of-function causes a neurological phenotype. Although the exact mechanism of disease resulting from alterations in YWHAG is not fully known, it is possible that haploinsufficiency of YWHAG in developing cerebral cortex may lead to abnormal neuronal migration resulting in DEE.
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Affiliation(s)
- Farah Kanani
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Hannah Titheradge
- Clinical Genetics, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Nicola Cooper
- Clinical Genetics, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Frances Elmslie
- South West Thames Regional Genetics Service, St George's, University of London, UK
| | - Melissa M Lees
- North East Regional Genetics Service, Great Ormond Street Hospital, London, UK
| | - Jane Juusola
- Clinical Genomics and Research Programs, Gaithersburg, Maryland
| | - Laura Pisani
- Human Genetics & Genomics, Northwell Health System, New York, USA
| | - Carolyn McKenna
- Human Genetics & Genomics, Northwell Health System, New York, USA
| | - Cyril Mignot
- Assistance Publique-Hôpitaux de Paris, Département de Génétique and Centre de Référence Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, France
| | - Stephanie Valence
- Assistance Publique-Hôpitaux de Paris, Service de Neuropédiatrie, Hôpital Armand Trousseau
| | - Boris Keren
- Département de génétique, hôpital Pitié-Salpêtrière, Assistance publique-Hôpitaux de Paris, France
| | - Katherine Lachlan
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
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- Wellcome Trust Sanger Institute, Cambridge, UK
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK.,Academic Unit of Child Health, University of Sheffield, Sheffield, UK
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Yahyaoui R, Pérez-Frías J. Amino Acid Transport Defects in Human Inherited Metabolic Disorders. Int J Mol Sci 2019; 21:ijms21010119. [PMID: 31878022 PMCID: PMC6981491 DOI: 10.3390/ijms21010119] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023] Open
Abstract
Amino acid transporters play very important roles in nutrient uptake, neurotransmitter recycling, protein synthesis, gene expression, cell redox balance, cell signaling, and regulation of cell volume. With regard to transporters that are closely connected to metabolism, amino acid transporter-associated diseases are linked to metabolic disorders, particularly when they involve different organs, cell types, or cell compartments. To date, 65 different human solute carrier (SLC) families and more than 400 transporter genes have been identified, including 11 that are known to include amino acid transporters. This review intends to summarize and update all the conditions in which a strong association has been found between an amino acid transporter and an inherited metabolic disorder. Many of these inherited disorders have been identified in recent years. In this work, the physiological functions of amino acid transporters will be described by the inherited diseases that arise from transporter impairment. The pathogenesis, clinical phenotype, laboratory findings, diagnosis, genetics, and treatment of these disorders are also briefly described. Appropriate clinical and diagnostic characterization of the underlying molecular defect may give patients the opportunity to avail themselves of appropriate therapeutic options in the future.
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Affiliation(s)
- Raquel Yahyaoui
- Laboratory of Metabolic Disorders and Newborn Screening Center of Eastern Andalusia, Málaga Regional University Hospital, 29011 Málaga, Spain
- Grupo Endocrinología y Nutrición, Diabetes y Obesidad, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain
- Correspondence:
| | - Javier Pérez-Frías
- Grupo Multidisciplinar de Investigación Pediátrica, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain;
- Departamento de Farmacología y Pediatría, Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
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40
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Diaz Verdugo C, Myren-Svelstad S, Aydin E, Van Hoeymissen E, Deneubourg C, Vanderhaeghe S, Vancraeynest J, Pelgrims R, Cosacak MI, Muto A, Kizil C, Kawakami K, Jurisch-Yaksi N, Yaksi E. Glia-neuron interactions underlie state transitions to generalized seizures. Nat Commun 2019; 10:3830. [PMID: 31444362 DOI: 10.1038/s41467-019-11739-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/31/2019] [Indexed: 11/08/2022] Open
Abstract
Brain activity and connectivity alter drastically during epileptic seizures. The brain networks shift from a balanced resting state to a hyperactive and hypersynchronous state. It is, however, less clear which mechanisms underlie the state transitions. By studying neural and glial activity in zebrafish models of epileptic seizures, we observe striking differences between these networks. During the preictal period, neurons display a small increase in synchronous activity only locally, while the gap-junction-coupled glial network was highly active and strongly synchronized across large distances. The transition from a preictal state to a generalized seizure leads to an abrupt increase in neural activity and connectivity, which is accompanied by a strong alteration in glia-neuron interactions and a massive increase in extracellular glutamate. Optogenetic activation of glia excites nearby neurons through the action of glutamate and gap junctions, emphasizing a potential role for glia-glia and glia-neuron connections in the generation of epileptic seizures. During epileptic seizures, neural activity across the brain switches into a hyperactive and hypersynchronized state. Here, the authors report on the role of glia-glia and glia-neuron interactions in mediating the changes that result in the ictal state in a zebrafish model of epilepsy.
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Demos M, Guella I, DeGuzman C, McKenzie MB, Buerki SE, Evans DM, Toyota EB, Boelman C, Huh LL, Datta A, Michoulas A, Selby K, Bjornson BH, Horvath G, Lopez-Rangel E, van Karnebeek CDM, Salvarinova R, Slade E, Eydoux P, Adam S, Van Allen MI, Nelson TN, Bolbocean C, Connolly MB, Farrer MJ. Diagnostic Yield and Treatment Impact of Targeted Exome Sequencing in Early-Onset Epilepsy. Front Neurol 2019; 10:434. [PMID: 31164858 PMCID: PMC6536592 DOI: 10.3389/fneur.2019.00434] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 04/09/2019] [Indexed: 12/12/2022] Open
Abstract
Targeted whole-exome sequencing (WES) is a powerful diagnostic tool for a broad spectrum of heterogeneous neurological disorders. Here, we aim to examine the impact on diagnosis, treatment and cost with early use of targeted WES in early-onset epilepsy. WES was performed on 180 patients with early-onset epilepsy (≤5 years) of unknown cause. Patients were classified as Retrospective (epilepsy diagnosis >6 months) or Prospective (epilepsy diagnosis <6 months). WES was performed on an Ion Proton™ and variant reporting was restricted to the sequences of 620 known epilepsy genes. Diagnostic yield and time to diagnosis were calculated. An analysis of cost and impact on treatment was also performed. A molecular diagnoses (pathogenic/likely pathogenic variants) was achieved in 59/180 patients (33%). Clinical management changed following WES findings in 23 of 59 diagnosed patients (39%) or 13% of all patients. A possible diagnosis was identified in 21 additional patients (12%) for whom supporting evidence is pending. Time from epilepsy onset to a genetic diagnosis was faster when WES was performed early in the diagnostic process (mean: 145 days Prospective vs. 2,882 days Retrospective). Costs of prior negative tests averaged $8,344 per patient in the Retrospective group, suggesting savings of $5,110 per patient using WES. These results highlight the diagnostic yield, clinical utility and potential cost-effectiveness of using targeted WES early in the diagnostic workup of patients with unexplained early-onset epilepsy. The costs and clinical benefits are likely to continue to improve. Advances in precision medicine and further studies regarding impact on long-term clinical outcome will be important.
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Affiliation(s)
- Michelle Demos
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Ilaria Guella
- Department of Medical Genetics, Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
| | - Conrado DeGuzman
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Marna B McKenzie
- Department of Medical Genetics, Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
| | - Sarah E Buerki
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada.,Division of Neuropediatrics, University Children's Hospital Zurich, Zurich, Switzerland
| | - Daniel M Evans
- Department of Medical Genetics, Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
| | - Eric B Toyota
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Cyrus Boelman
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Linda L Huh
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Anita Datta
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Aspasia Michoulas
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Kathryn Selby
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Bruce H Bjornson
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Gabriella Horvath
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Elena Lopez-Rangel
- Division of Developmental Pediatrics, Department of Pediatrics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Clara D M van Karnebeek
- Department of Pediatrics, Centre for Molecular Medicine and Therapeutics, BCCHRI, University of British Columbia, Vancouver, BC, Canada.,Department of Pediatrics, Academic Medical Centre, Amsterdam, Netherlands
| | - Ramona Salvarinova
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Erin Slade
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Patrice Eydoux
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Shelin Adam
- Department of Medical Genetics, BC Children's and BC's Women's Hospitals, University of British Columbia, Vancouver, BC, Canada
| | - Margot I Van Allen
- Department of Medical Genetics, BC Children's and BC's Women's Hospitals, University of British Columbia, Vancouver, BC, Canada
| | - Tanya N Nelson
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Corneliu Bolbocean
- University of Tennessee Health Science Center, Memphis, TN, United States.,Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Mary B Connolly
- Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada
| | - Matthew J Farrer
- Department of Medical Genetics, Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
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Stergachis AB, Pujol-Giménez J, Gyimesi G, Fuster D, Albano G, Troxler M, Picker J, Rosenberg PA, Bergin A, Peters J, El Achkar CM, Harini C, Manzi S, Rotenberg A, Hediger MA, Rodan LH. Recurrent SLC1A2 variants cause epilepsy via a dominant negative mechanism. Ann Neurol 2019; 85:921-926. [PMID: 30937933 DOI: 10.1002/ana.25477] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/11/2019] [Accepted: 03/31/2019] [Indexed: 12/20/2022]
Abstract
SLC1A2 is a trimeric transporter essential for clearing glutamate from neuronal synapses. Recurrent de novo SLC1A2 missense variants cause a severe, early onset developmental and epileptic encephalopathy via an unclear mechanism. We demonstrate that all 3 variants implicated in this condition localize to the trimerization domain of SLC1A2, and that the Leu85Pro variant acts via a dominant negative mechanism to reduce, but not eliminate, wild-type SLC1A2 protein localization and function. Finally, we demonstrate that treatment of a 20-month-old SLC1A2-related epilepsy patient with the SLC1A2-modulating agent ceftriaxone did not result in a significant change in daily spasm count. ANN NEUROL 2019;85:921-926.
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Affiliation(s)
- Andrew B Stergachis
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA
| | - Jonai Pujol-Giménez
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Gergely Gyimesi
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Daniel Fuster
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Giusppe Albano
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Marina Troxler
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Jonathan Picker
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Paul A Rosenberg
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Ann Bergin
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Jurriaan Peters
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | | - Chellamani Harini
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Shannon Manzi
- Department of Pharmacy, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Alexander Rotenberg
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Matthias A Hediger
- Department of Nephrology and Hypertension, University Hospital Bern, Inselspital, Bern, Switzerland.,Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Lance H Rodan
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA.,Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA
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43
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Das S, Baruah C, Saikia AK, Tiwari D, Bose S. Genetic and expression changes in TNF-α as a risk factor for rheumatoid arthritis pathogenesis in northeast India. J Genet 2019; 98:3. [PMID: 30945669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Antitumour necrosis factor-alpha (TNF-α) therapy is used as a clinical intervention for rheumatoid arthritis (RA) but differences exist in response to the treatment which makes the candidature of the screening of TNF-α alteration(s) at genetic and expression levels an important agenda prior to treatment. This study aims to determine the associative role of TNF-α -308G/A polymorphism and differential expression of TNF-α in the pathogenesis of RA. A case-control study where a total of 126 RA patients were enrolled based on ACR-EULAR (2010) criteria, along with 160 community matched age and sex controls over a period of three years. The differential expression level of TNF-α mRNA and protein level was studied and TNF-α -308G/A polymorphism was screened by T-ARMS PCR assay. All statistical analysis was performed using SPSS software. mRNA expression level of TNF-α was upregulated in RA cases (avg. 15.85 ± 9.52 fold) compared to control. TNF-α protein level was found to be higher in RA cases (28.62±7.17 pg/mL) compared to control (23.14±6.91 pg/mL). TNF-α -308 variant GA genotype was higher in RA (46.03%) than in control (25%). The presence of TNF-α -308 variant A allele was associated with increased risk of RA susceptibility (odds ratio (OR) = 2.559 at 95% confidence interval (CI), P< 0.001) but not severity (OR = 1.617 at 95% CI, P = 0.571). The presence of -308 variant genotype was associated with a higher TNF-α mRNA and protein expression. The presence of TNF-α -308A allele is associated with increased risk of RA susceptibility and differential TNF-α expression, and has prognostic significance. Association of higher TNF-α pro-inflammatory cytokine levels with northeast Indian patients makes them suitable subjects for anti-TNF-α therapy.
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Affiliation(s)
- Somdatta Das
- Department of Bioengineering and Technology, Gauhati University, Guwahati 781 014, India.
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44
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Lallar M, Srivastava P, Rai A, Saxena D, Mandal K, Phadke SR. Cytogenetic microarray in structurally normal and abnormal foetuses: a five years experience elucidating increasing acceptance and clinical utility. J Genet 2019; 98. [DOI: 10.1007/s12041-018-1050-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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45
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Møller RS, Hammer TB, Rubboli G, Lemke JR, Johannesen KM. From next-generation sequencing to targeted treatment of non-acquired epilepsies. Expert Rev Mol Diagn 2019; 19:217-228. [DOI: 10.1080/14737159.2019.1573144] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Rikke S. Møller
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Trine B. Hammer
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
| | - Guido Rubboli
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Johannes R. Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Katrine M. Johannesen
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
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46
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Kim DE, Cho CH, Sim KM, Kwon O, Hwang EM, Kim HW, Park JY. 14-3-3γ Haploinsufficient Mice Display Hyperactive and Stress-sensitive Behaviors. Exp Neurobiol 2019; 28:43-53. [PMID: 30853823 PMCID: PMC6401549 DOI: 10.5607/en.2019.28.1.43] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 02/03/2023] Open
Abstract
14-3-3γ plays diverse roles in different aspects of cellular processes. Especially in the brain where 14-3-3γ is enriched, it has been reported to be involved in neurological and psychiatric diseases (e.g. Williams-Beuren syndrome and Creutzfeldt-Jakob disease). However, behavioral abnormalities related to 14-3-3γ deficiency are largely unknown. Here, by using 14-3-3γ deficient mice, we found that homozygous knockout mice were prenatally lethal, and heterozygous mice showed developmental delay relative to wild-type littermate mice. In addition, in behavioral analyses, we found that 14-3-3γ heterozygote mice display hyperactive and depressive-like behavior along with more sensitive responses to acute stress than littermate control mice. These results suggest that 14-3-3γ levels may be involved in the developmental manifestation of related neuropsychiatric diseases. In addition, 14-3-3γ heterozygote mice may be a potential model to study the molecular pathophysiology of neuropsychiatric symptoms.
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Affiliation(s)
- Do Eon Kim
- College of Life Sciences, Sejong University, Seoul 05006, Korea
| | - Chang-Hoon Cho
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
| | - Kyoung Mi Sim
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
| | - Osung Kwon
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
| | - Eun Mi Hwang
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Hyung-Wook Kim
- College of Life Sciences, Sejong University, Seoul 05006, Korea
| | - Jae-Yong Park
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02708, Korea
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47
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Coe BP, Stessman HAF, Sulovari A, Geisheker MR, Bakken TE, Lake AM, Dougherty JD, Lein ES, Hormozdiari F, Bernier RA, Eichler EE. Neurodevelopmental disease genes implicated by de novo mutation and copy number variation morbidity. Nat Genet 2019; 51:106-16. [PMID: 30559488 DOI: 10.1038/s41588-018-0288-4] [Citation(s) in RCA: 180] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 10/23/2018] [Indexed: 12/11/2022]
Abstract
We combined de novo mutation (DNM) data from 10,927 individuals with developmental delay and autism to identify 253 candidate neurodevelopmental disease genes with an excess of missense and/or likely gene-disruptive (LGD) mutations. Of these genes, 124 reach exome-wide significance (P < 5 × 10-7) for DNM. Intersecting these results with copy number variation (CNV) morbidity data shows an enrichment for genomic disorder regions (30/253, likelihood ratio (LR) +1.85, P = 0.0017). We identify genes with an excess of missense DNMs overlapping deletion syndromes (for example, KIF1A and the 2q37 deletion) as well as duplication syndromes, such as recurrent MAPK3 missense mutations within the chromosome 16p11.2 duplication, recurrent CHD4 missense DNMs in the 12p13 duplication region, and recurrent WDFY4 missense DNMs in the 10q11.23 duplication region. Network analyses of genes showing an excess of DNMs highlights functional networks, including cell-specific enrichments in the D1+ and D2+ spiny neurons of the striatum.
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48
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Chen X, Jin J, Wang Q, Xue H, Zhang N, Du Y, Zhang T, Zhang B, Wu J, Liu Z. A de novo pathogenic CSNK1E mutation identified by exome sequencing in family trios with epileptic encephalopathy. Hum Mutat 2018; 40:281-287. [PMID: 30488659 DOI: 10.1002/humu.23690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 11/07/2018] [Accepted: 11/24/2018] [Indexed: 12/29/2022]
Abstract
Recent whole-exome sequencing (WES) studies have demonstrated the contribution of de novo mutations (DNMs) to epileptic encephalopathies (EEs). Here, we performed WES on four trios with West syndrome and identified three loss-of-function DNMs in both CSNK1E (c.885+1G>A) and STXBP1 (splicing, c.1111-2A>G; nonsense, p.(Y519X)). The splicing mutation in CSNK1E creates insertion of 116 new amino acids at position 246 followed by a premature stop codon. Both CSNK1E and STXBP1 showed a closer coexpression relationship with epilepsy candidate genes beyond that expected by chance. In addition, genes coexpressed with CSNK1E were enriched in early prenatal stages across multiple brain regions. We also found that 60 CSNK1E-interacting genes share an association with multiple neuropsychiatric disorders, and these genes formed a significant interconnected interaction network with roles in the midbrain development. Our study supported the potential role of CSNK1E variants in EE susceptibility and expanded the phenotypic spectrum associated with CSNK1E variation.
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Affiliation(s)
- Xiaomin Chen
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Center of Scientific Research, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jing Jin
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Qiongdan Wang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Department of Laboratory Medicine, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Huangqi Xue
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Na Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yaoqiang Du
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Research Center of Blood Transfusion Medicine, Education Ministry Key Laboratory of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Tao Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Bing Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jinyu Wu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zhenwei Liu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
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Zhou R, Jiang G, Tian X, Wang X. Progress in the molecular mechanisms of genetic epilepsies using patient-induced pluripotent stem cells. Epilepsia Open 2018; 3:331-339. [PMID: 30187003 PMCID: PMC6119748 DOI: 10.1002/epi4.12238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2018] [Indexed: 12/29/2022] Open
Abstract
Research findings on the molecular mechanisms of epilepsy almost always originate from animal experiments, and the development of induced pluripotent stem cell (iPSC) technology allows the use of human cells with genetic defects for studying the molecular mechanisms of genetic epilepsy (GE) for the first time. With iPSC technology, terminally differentiated cells collected from GE patients with specific genetic etiologies can be differentiated into many relevant cell subtypes that carry all of the GE patient's genetic information. iPSCs have opened up a new research field involving the pathogenesis of GE. Using this approach, studies have found that gene mutations induce GE by altering the balance between neuronal excitation and inhibition, which is associated. among other factors, with neuronal developmental disturbances, ion channel abnormalities, and synaptic dysfunction. Simultaneously, astrocyte activation, mitochondrial dysfunction, and abnormal signaling pathway activity are also important factors in the molecular mechanisms of GE.
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Affiliation(s)
- Ruijiao Zhou
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Guohui Jiang
- Department of Neurology Institute of Neurological Diseases Affiliated Hospital of North Sichuan Medical College Nanchong China
| | - Xin Tian
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Xuefeng Wang
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
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50
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Sugimoto J, Tanaka M, Sugiyama K, Ito Y, Aizawa H, Soma M, Shimizu T, Mitani A, Tanaka K. Region-specific deletions of the glutamate transporter GLT1 differentially affect seizure activity and neurodegeneration in mice. Glia 2017; 66:777-788. [PMID: 29214672 DOI: 10.1002/glia.23281] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 11/06/2022]
Abstract
Glial glutamate transporter GLT1 plays a key role in the maintenance of extracellular glutamate homeostasis. Recent human genetic studies have suggested that de novo mutations in GLT1 (EAAT2) cause early-onset epilepsy with multiple seizure types. Consistent with these findings, global GLT1 null mice show lethal spontaneous seizures. The consequences of GLT1 dysfunction vary between different brain regions, suggesting that the role of GLT1 dysfunction in epilepsy may also vary with brain regions. In this study, we generated region-specific GLT1 knockout mice by crossing floxed-GLT1 mice with mice that express the Cre recombinase in a particular domain of the ventricular zone. Selective deletion of GLT1 in the diencephalon, brainstem and spinal cord is sufficient to reproduce the phenotypes (excess mortality, decreased body weight, and lethal spontaneous seizure) of the global GLT1 null mice. By contrast, dorsal forebrain-specific GLT1 knockout mice showed nonlethal complex seizures including myoclonic jerks, hyperkinetic running, spasm and clonic convulsion via the activation of NMDA receptors during a limited period from P12 to P14 and selective neuronal death in cortical layer II/III and the hippocampus. Thus, GLT1 dysfunction in the dorsal forebrain is involved in the pathogenesis of infantile epilepsy and GLT1 in the diencephalon, brainstem and spinal cord may play a critical role in preventing seizure-induced sudden death.
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Affiliation(s)
- Junya Sugimoto
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Moeko Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Kaori Sugiyama
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Yukiko Ito
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Hidenori Aizawa
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Miho Soma
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Tomoko Shimizu
- Laboratory of Physiology, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Akira Mitani
- Laboratory of Physiology, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.,Center for Brain Integration Research (CBIR), TMDU, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
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