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Gallagher D, Pérez-Palma E, Bruenger T, Ghanty I, Brilstra E, Ceulemans B, Chemaly N, de Lange I, Depienne C, Guerrini R, Mei D, Møller RS, Nabbout R, Regan BM, Schneider AL, Scheffer IE, Schoonjans AS, Symonds JD, Weckhuysen S, Zuberi SM, Lal D, Brunklaus A. Genotype-phenotype associations in 1018 individuals with SCN1A-related epilepsies. Epilepsia 2024; 65:1046-1059. [PMID: 38410936 DOI: 10.1111/epi.17882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE SCN1A variants are associated with epilepsy syndromes ranging from mild genetic epilepsy with febrile seizures plus (GEFS+) to severe Dravet syndrome (DS). Many variants are de novo, making early phenotype prediction difficult, and genotype-phenotype associations remain poorly understood. METHODS We assessed data from a retrospective cohort of 1018 individuals with SCN1A-related epilepsies. We explored relationships between variant characteristics (position, in silico prediction scores: Combined Annotation Dependent Depletion (CADD), Rare Exome Variant Ensemble Learner (REVEL), SCN1A genetic score), seizure characteristics, and epilepsy phenotype. RESULTS DS had earlier seizure onset than other GEFS+ phenotypes (5.3 vs. 12.0 months, p < .001). In silico variant scores were higher in DS versus GEFS+ (p < .001). Patients with missense variants in functionally important regions (conserved N-terminus, S4-S6) exhibited earlier seizure onset (6.0 vs. 7.0 months, p = .003) and were more likely to have DS (280/340); those with missense variants in nonconserved regions had later onset (10.0 vs. 7.0 months, p = .036) and were more likely to have GEFS+ (15/29, χ2 = 19.16, p < .001). A minority of protein-truncating variants were associated with GEFS+ (10/393) and more likely to be located in the proximal first and last exon coding regions than elsewhere in the gene (9.7% vs. 1.0%, p < .001). Carriers of the same missense variant exhibited less variability in age at seizure onset compared with carriers of different missense variants for both DS (1.9 vs. 2.9 months, p = .001) and GEFS+ (8.0 vs. 11.0 months, p = .043). Status epilepticus as presenting seizure type is a highly specific (95.2%) but nonsensitive (32.7%) feature of DS. SIGNIFICANCE Understanding genotype-phenotype associations in SCN1A-related epilepsies is critical for early diagnosis and management. We demonstrate an earlier disease onset in patients with missense variants in important functional regions, the occurrence of GEFS+ truncating variants, and the value of in silico prediction scores. Status epilepticus as initial seizure type is a highly specific, but not sensitive, early feature of DS.
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Affiliation(s)
- Declan Gallagher
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago, Chile
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Tobias Bruenger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Ismael Ghanty
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eva Brilstra
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Berten Ceulemans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Nicole Chemaly
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Iris de Lange
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Davide Mei
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Rikke S Møller
- Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Brigid M Regan
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Amy L Schneider
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia
| | - An-Sofie Schoonjans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB Center for Molecular Neurology, Antwerp, Belgium
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium
- Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Stanley Center for Psychiatric Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Neurology, McGovern Medical School, UTHealth Houston, Houston, Texas, USA
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
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Elmardenly A, Aljehani Z, Tamim A, Alyazidi A, Muthaffar O. Efficacy and Safety of Perampanel in Children with Drug-Resistant Focal-Onset Seizures: A Retrospective Review. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1071. [PMID: 37371302 DOI: 10.3390/children10061071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023]
Abstract
BACKGROUND Epilepsy is one of the most common neurological disorders. Existing antiseizure medications (ASMs) are still unable to control seizures in one-third of these patients, making the discovery of antiseizure therapies with novel mechanisms of action a necessity. AIM OF THE STUDY This study aimed to determine the safety and efficacy of perampanel (PER) as an adjuvant treatment for children with drug-resistant focal-onset seizures with or without focal to bilateral tonic-clonic seizures. PATIENTS AND METHODS This is a single-center retrospective study of 38 epileptic pediatric patients, aged 2 to 14, at King Faisal Specialist Hospital and Research Center whose seizures were pharmaco-resistant to more than two antiseizure medications and followed for at least three months after PER adjuvant therapy initiation. Efficacy was assessed by the PER response rate at 3-, 6-, and 12-month follow-up evaluations, and side effects were also reported. RESULTS Multiple seizure types were reported. Myoclonic seizures were the predominant type of epilepsy in 17 children (44.7%). At 3 months, 6 months, and 12 months of follow-up, approximately 23.4%, 23.4%, and 18.4% of the patients were seizure-free at these time points, respectively. Adverse events were documented in 14 patients (35.7%) and led to the discontinuation of PER in 26.3%, 31.6%, and 36.8% of the studied group at the 3-, 6-, and 12-month follow-ups, respectively. The most common adverse events included dizziness or drowsiness, irritability, gait disturbance, and confusion; however, all were transient, and no serious adverse effects occurred. CONCLUSION Our findings confirm the therapeutic efficacy of adjunctive PER in the treatment of drug-resistant epilepsy in children. As an adjunctive treatment for epilepsy, perampanel demonstrated sufficient effectiveness and tolerability.
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Affiliation(s)
- Ahmed Elmardenly
- Department of Pediatrics, King Faisal Specialist Hospital & Research Centre, Jeddah 23431, Saudi Arabia
| | - Zekra Aljehani
- Medical/Critical Pharmacy Department, Pharmaceutical Care Division, King Faisal Specialist Hospital and Research Centre, Jeddah 23431, Saudi Arabia
| | - Abdullah Tamim
- Department of Pediatrics, King Faisal Specialist Hospital & Research Centre, Jeddah 23431, Saudi Arabia
| | - Anas Alyazidi
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Osama Muthaffar
- Department of Pediatrics, King Faisal Specialist Hospital & Research Centre, Jeddah 23431, Saudi Arabia
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Wen F, Tan Z, Huang D, Jiang Y, Xiang J. LncRNA PVT1 Promotes Neuronal Cell Apoptosis and Neuroinflammation by Regulating miR-488-3p/FOXD3/SCN2A Axis in Epilepsy. Neurochem Res 2023; 48:895-908. [PMID: 36378391 DOI: 10.1007/s11064-022-03801-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/08/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022]
Abstract
It is vital to understand the mechanism of epilepsy onset and development. Dysregulated lncRNAs are closely associated with epilepsy. Our work probed the role of lncRNA PVT1/miR-488-3p/FOXD3/SCN2A axis in epilepsy. The mRNA and protein expressions were assessed using qRT-PCR and western blot. MTT assay and TUNEL staining were conducted to assess cell viability and apoptosis, respectively. TNFα, IL-1β and IL-6 levels were analyzed using ELISA. LDH level was tested by Assay Kit. The binding relationship between PVT1, miR-488-3p and FOXD3 were verified using dual luciferase reporter gene assay. The epilepsy model of rats was established by lithium-pilocarpine injection. Nissl staining was performed to evaluate neuronal damage. PVT1 was markedly upregulated in epilepsy model cells. Knockdown of PVT1 increased the viability, while repressed the apoptosis and inflammatory cytokines secretion as well as LDH level in epilepsy cell model. MiR-488-3p alleviated neuronal injury and neuroinflammation in model cells. MiR-488-3p functioned as the direct target of PVT1, and its inhibition neutralized the effects of PVT1 silencing on neuronal cell injury and neuroinflammation in model cells. Furthermore, miR-488-3p inhibited neuronal cell injury and neuroinflammation in model cells by regulating FOXD3/SCN2A pathway. Finally, animal experiments proved that PVT1 promoted epilepsy-induced neuronal cell injury and neuroinflammation by regulating miR-488-3p-mediated FOXD3/SCN2A pathway. PVT1 promoted neuronal cell injury and inflammatory response in epilepsy via inhibiting miR-488-3p and further regulating FOXD3/SCN2A pathway.
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Affiliation(s)
- Fang Wen
- Department of Neurology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Zhigang Tan
- Department of Neurosurgery, The Second Xiangya Hospital of Central South University, No. 139, Renmin Road, Changsha, 410011, Hunan, People's Republic of China
| | - Dezhi Huang
- Department of Neurosurgery, The Second Xiangya Hospital of Central South University, No. 139, Renmin Road, Changsha, 410011, Hunan, People's Republic of China
| | - Yugang Jiang
- Department of Neurosurgery, The Second Xiangya Hospital of Central South University, No. 139, Renmin Road, Changsha, 410011, Hunan, People's Republic of China
| | - Jun Xiang
- Department of Neurosurgery, The Second Xiangya Hospital of Central South University, No. 139, Renmin Road, Changsha, 410011, Hunan, People's Republic of China.
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Sakellakis M, Chalkias A. The Role οf Ion Channels in the Development and Progression of Prostate Cancer. Mol Diagn Ther 2023; 27:227-242. [PMID: 36600143 DOI: 10.1007/s40291-022-00636-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2022] [Indexed: 01/06/2023]
Abstract
Ion channels have major regulatory functions in living cells. Apart from their role in ion transport, they are responsible for cellular electrogenesis and excitability, and may also regulate tissue homeostasis. Although cancer is not officially classified as a channelopathy, it has been increasingly recognized that ion channel aberrations play an important role in virtually all cancer types. Ion channels can exert pro-tumorigenic activities due to genetic or epigenetic alterations, or as a response to molecular signals, such as growth factors, hormones, etc. Increasing evidence suggests that ion channels and pumps play a critical role in the regulation of prostate cancer cell proliferation, apoptosis evasion, migration, epithelial-to-mesenchymal transition, and angiogenesis. There is also evidence suggesting that ion channels might play a role in treatment failure in patients with prostate cancer. Hence, they represent promising targets for diagnosis, staging, and treatment, and their effects may be of particular significance for specific patient populations, including those undergoing anesthesia and surgery. In this article, the role of major types of ion channels involved in the development and progression of prostate cancer are reviewed. Identifying the underlying molecular mechanisms of the pro-tumorigenic effects of ion channels may potentially inform the development of novel therapeutic strategies to counter this malignancy.
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Affiliation(s)
- Minas Sakellakis
- Hellenic GU Cancer Group, Athens, Greece. .,Department of Medical Oncology, Metropolitan Hospital, 9 Ethnarchou Makariou, 18547, Athens, Greece.
| | - Athanasios Chalkias
- Department of Anesthesiology, Faculty of Medicine, University of Thessaly, Larissa, Greece.,Outcomes Research Consortium, Cleveland, OH, USA
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Tian T, Cai Y, Qin X, Wang J, Wang Y, Yang X. Forebrain E-I balance controlled in cognition through coordinated inhibition and inhibitory transcriptome mechanism. Front Cell Neurosci 2023; 17:1114037. [PMID: 36909282 PMCID: PMC10000298 DOI: 10.3389/fncel.2023.1114037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/31/2023] [Indexed: 02/26/2023] Open
Abstract
Introduction Forebrain neural networks are vital for cognitive functioning, and their excitatory-inhibitory (E-I) balance is governed by neural homeostasis. However, the homeostatic control strategies and transcriptomic mechanisms that maintain forebrain E-I balance and optimal cognition remain unclear. Methods We used patch-clamp and RNA sequencing to investigate the patterns of neural network homeostasis with suppressing forebrain excitatory neural activity and spatial training. Results We found that inhibitory transmission and receptor transcription were reduced in tamoxifen-inducible Kir2.1 conditional knock-in mice. In contrast, spatial training increased inhibitory synaptic connections and the transcription of inhibitory receptors. Discussion Our study provides significant evidence that inhibitory systems play a critical role in the homeostatic control of the E-I balance in the forebrain during cognitive training and E-I rebalance, and we have provided insights into multiple gene candidates for cognition-related homeostasis in the forebrain.
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Affiliation(s)
- Tian Tian
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - You Cai
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Department of Neurology, Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Xin Qin
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, BC, Canada
| | - Jiangang Wang
- Henan International Joint Laboratory of Non-Invasive Neuromodulation, Department of Physiology and Pathophysiology, Xinxiang Medical University, Xinxiang, China
| | - Yali Wang
- Henan International Joint Laboratory of Non-Invasive Neuromodulation, Department of Physiology and Pathophysiology, Xinxiang Medical University, Xinxiang, China
| | - Xin Yang
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Zheng XX, You YX, Zhao LL, Du Y, Xu SQ, Tang DQ. Effects of UGT1A, CYP2C9/19 and ABAT polymorphisms on plasma concentration of valproic acid in Chinese epilepsy patients. Pharmacogenomics 2023; 24:153-162. [PMID: 36718958 DOI: 10.2217/pgs-2022-0156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Aim: To evaluate the association between genetic polymorphisms and plasma concentration-to-dose ratio of valproic acid (CDRV) in Chinese epileptic patients. Methods: A total of 46 epileptic patients treated with valproic acid therapy were enrolled. 18 SNPs in nine genes related to valproic acid were directly sequenced with Sanger methods. Results: Patients carrying UGT1A6 heterozygous genotypes had significantly lower CDRV than those carrying the wild-type genotypes. In contrast, patients with the homozygote genotypes of CYP2C9 and ABAT had higher CDRV than those with the wild-type genotypes and patients with the heterozygous genotypes of CYP2C19 had higher CDRV. Conclusion: Detection of genetic polymorphism in these genes might facilitate an appropriate dose of valproic acid for epileptic patients. Further studies with larger cohorts are necessary to underpin these observations.
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Affiliation(s)
- Xiao-Xiao Zheng
- Department of Clinical Pharmacy, Xuzhou Municipal Hospital Affiliated to Xuzhou Medical University, 269 University Road, Xuzhou City, Jiangsu Province, P.R. China
| | - Yu-Xin You
- Jiangsu Key Laboratory of New Drug Research & Clinical Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China
| | - Lin-Lin Zhao
- Jiangsu Key Laboratory of New Drug Research & Clinical Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China
| | - Yan Du
- Jiangsu Key Laboratory of New Drug Research & Clinical Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China.,Department of Pharmaceutical Analysis, Xuzhou Medical University, Xuzhou, 221004, China
| | - Sheng-Qiu Xu
- Department of Clinical Pharmacy, Xuzhou Municipal Hospital Affiliated to Xuzhou Medical University, 269 University Road, Xuzhou City, Jiangsu Province, P.R. China
| | - Dao-Quan Tang
- Jiangsu Key Laboratory of New Drug Research & Clinical Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China.,Department of Pharmaceutical Analysis, Xuzhou Medical University, Xuzhou, 221004, China
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Anderson LL, Bahceci DA, Hawkins NA, Everett-Morgan D, Banister SD, Kearney JA, Arnold JC. Heterozygous deletion of Gpr55 does not affect a hyperthermia-induced seizure, spontaneous seizures or survival in the Scn1a+/- mouse model of Dravet syndrome. PLoS One 2023; 18:e0280842. [PMID: 36701411 PMCID: PMC9879440 DOI: 10.1371/journal.pone.0280842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
A purified preparation of cannabidiol (CBD), a cannabis constituent, has been approved for the treatment of intractable childhood epilepsies such as Dravet syndrome. Extensive pharmacological characterization of CBD shows activity at numerous molecular targets but its anticonvulsant mechanism(s) of action is yet to be delineated. Many suggest that the anticonvulsant action of CBD is the result of G protein-coupled receptor 55 (GPR55) inhibition. Here we assessed whether Gpr55 contributes to the strain-dependent seizure phenotypes of the Scn1a+/- mouse model of Dravet syndrome. The Scn1a+/- mice on a 129S6/SvEvTac (129) genetic background have no overt phenotype, while those on a [129 x C57BL/6J] F1 background exhibit a severe phenotype that includes hyperthermia-induced seizures, spontaneous seizures and reduced survival. We observed greater Gpr55 transcript expression in the cortex and hippocampus of mice on the seizure-susceptible F1 background compared to those on the seizure-resistant 129 genetic background, suggesting that Gpr55 might be a genetic modifier of Scn1a+/- mice. We examined the effect of heterozygous genetic deletion of Gpr55 and pharmacological inhibition of GPR55 on the seizure phenotypes of F1.Scn1a+/- mice. Heterozygous Gpr55 deletion and inhibition of GPR55 with CID2921524 did not affect the temperature threshold of a thermally-induced seizure in F1.Scn1a+/- mice. Neither was there an effect of heterozygous Gpr55 deletion observed on spontaneous seizure frequency or survival of F1.Scn1a+/- mice. Our results suggest that GPR55 antagonism may not be a suitable anticonvulsant target for Dravet syndrome drug development programs, although future research is needed to provide more definitive conclusions.
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Affiliation(s)
- Lyndsey L. Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Dilara A. Bahceci
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Nicole A. Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Evanston, IL, United States of America
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Jennifer A. Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Evanston, IL, United States of America
| | - Jonathon C. Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
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8
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Atlı E, Gürkan H, Güldiken B, Eker D, Yalçıntepe S, Demir S, Atlı Eİ. Investigation of the Genetic Etiology in Idiopathic Generalized Epileptic Disorders by Targeted Next-generation Sequencing Technique. Balkan Med J 2023; 40:13-20. [PMID: 36374051 PMCID: PMC9874255 DOI: 10.4274/balkanmedj.galenos.2022.2022-7-55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background Idiopathic generalized epilepsy is the most common group of epilepsy disorders in children and adolescents. Various types of genetic abnormality were identified among the hereditary factors that explain epilepsy. Aims To determine the variations in the etiopathogenesis, treatment protocol planning, and prognosis of idiopathic generalized epilepsy using the next-generation sequencing method. Study Design A cross-sectional study. Methods This study included 32 patients with idiopathic generalized epilepsy. Genomic DNA was obtained from peripheral venous blood samples taken from the patients. A total of 18 genes encoding ion channel subunits that are involved in monogenic disorders and are associated with idiopathic generalized epilepsy were included. The targeted custom next-generation sequencing panel was designed to cover all coding exons and all exon/intron splice site regions of 18 genes. Results We detected 9 (28%) variations, including 1 likely pathogenic (a variant in the SCN1A gene) and 8 of unknown clinical significance (2 in the CLCN2 genes, GABBR2, SCN1B, SLC2A1, SLC4A10 genes, and 2 in the TBC1D24 gene). Conclusion Study results should be supported by functional advanced studies, with increased existing knowledge in the relevant variations.
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Affiliation(s)
- Engin Atlı
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Hakan Gürkan
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Babürhan Güldiken
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Damla Eker
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Sinem Yalçıntepe
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Selma Demir
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey
| | - Emine İkbal Atlı
- Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey,* Address for Correspondence: Department of Medical Genetics, Faculty of Medicine Trakya University, Edirne, Turkey E-mail:
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Hill SF, Ziobro JM, Jafar‐Nejad P, Rigo F, Meisler MH. Genetic interaction between Scn8a and potassium channel genes Kcna1 and Kcnq2. Epilepsia 2022; 63:e125-e131. [PMID: 35892317 PMCID: PMC9804156 DOI: 10.1111/epi.17374] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 01/07/2023]
Abstract
Voltage-gated sodium and potassium channels regulate the initiation and termination of neuronal action potentials. Gain-of-function mutations of sodium channel Scn8a and loss-of-function mutations of potassium channels Kcna1 and Kcnq2 increase neuronal activity and lead to seizure disorders. We tested the hypothesis that reducing the expression of Scn8a would compensate for loss-of-function mutations of Kcna1 or Kcnq2. Scn8a expression was reduced by the administration of an antisense oligonucleotide (ASO). This treatment lengthened the survival of the Kcn1a and Kcnq2 mutants, and reduced the seizure frequency in the Kcnq2 mutant mice. These observations suggest that reduction of SCN8A may be therapeutic for genetic epilepsies resulting from mutations in these potassium channel genes.
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Affiliation(s)
- Sophie F. Hill
- Neuroscience Graduate ProgramUniversity of MichiganAnn ArborMichiganUSA,Department of Human GeneticsUniversity of MichiganAnn ArborMichiganUSA
| | - Julie M. Ziobro
- Department of PediatricsUniversity of MichiganAnn ArborMichiganUSA
| | | | - Frank Rigo
- Ionis PharmaceuticalsCarlsbadCaliforniaUSA
| | - Miriam H. Meisler
- Neuroscience Graduate ProgramUniversity of MichiganAnn ArborMichiganUSA,Department of Human GeneticsUniversity of MichiganAnn ArborMichiganUSA,Department of NeurologyUniversity of MichiganAnn ArborMichiganUSA
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10
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Son JH, Do H, Han J. Intragenic L1 Insertion: One Possibility of Brain Disorder. Life (Basel) 2022; 12:life12091425. [PMID: 36143463 PMCID: PMC9505610 DOI: 10.3390/life12091425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/29/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
Long interspersed nuclear element 1 (LINE1, L1) is a retrotransposon comprising ~17% of the human genome. A subset of L1s maintains the potential to mobilize and alter the genomic landscape, consequently contributing to the change in genome integrity and gene expression. L1 retrotransposition occurs in the human brain regardless of disease status. However, in the brain of patients with various brain diseases, the expression level and copy number of L1 are significantly increased. In this review, we briefly introduce the methodologies applied to measure L1 mobility and identify genomic loci where new insertion of L1 occurs in the brain. Then, we present a list of genes disrupted by L1 transposition in the genome of patients with brain disorders. Finally, we discuss the association between genes disrupted by L1 and relative brain disorders.
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Affiliation(s)
- Ji-Hoon Son
- Graduate School of Medical Science and Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyunsu Do
- Graduate School of Medical Science and Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jinju Han
- Graduate School of Medical Science and Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
- BioMedical Research Center, KAIST, Daejeon 34141, Korea
- Correspondence:
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11
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Anderson LL, Doohan PT, Hawkins NA, Bahceci D, Thakur GA, Kearney JA, Arnold JC, Arnold JC. The endocannabinoid system impacts seizures in a mouse model of Dravet syndrome. Neuropharmacology 2022; 205:108897. [PMID: 34822817 PMCID: PMC9514665 DOI: 10.1016/j.neuropharm.2021.108897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/07/2021] [Accepted: 11/20/2021] [Indexed: 10/19/2022]
Abstract
Dravet syndrome is a catastrophic childhood epilepsy with multiple seizure types that are refractory to treatment. The endocannabinoid system regulates neuronal excitability so a deficit in endocannabinoid signaling could lead to hyperexcitability and seizures. Thus, we sought to determine whether a deficiency in the endocannabinoid system might contribute to seizure phenotypes in a mouse model of Dravet syndrome and whether enhancing endocannabinoid tone is anticonvulsant. Scn1a+/- mice model the clinical features of Dravet syndrome: hyperthermia-induced seizures, spontaneous seizures and reduced survival. We examined whether Scn1a+/- mice exhibit deficits in the endocannabinoid system by measuring brain cannabinoid receptor expression and endocannabinoid concentrations. Next, we determined whether pharmacologically enhanced endocannabinoid tone was anticonvulsant in Scn1a+/- mice. We used GAT229, a positive allosteric modulator of the cannabinoid (CB1) receptor, and ABX-1431, a compound that inhibits the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG). The Scn1a+/- phenotype is strain-dependent with mice on a 129S6/SvEvTac (129) genetic background having no overt phenotype and those on an F1 (129S6/SvEvTac x C57BL/6J) background exhibiting a severe epilepsy phenotype. We observed lower brain cannabinoid CB1 receptor expression in the seizure-susceptible F1 compared to seizure-resistant 129 strain, suggesting an endocannabinoid deficiency might contribute to seizure susceptibility. GAT229 and ABX-1431 were anticonvulsant against hyperthermia-induced seizures. However, subchronic ABX1431 treatment increased spontaneous seizure frequency despite reducing seizure severity. Cnr1 is a putative genetic modifier of epilepsy in the Scn1a+/- mouse model of Dravet syndrome. Compounds that increase endocannabinoid tone could be developed as novel treatments for Dravet syndrome.
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Affiliation(s)
- Lyndsey L. Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Peter T. Doohan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Nicole A. Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Dilara Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Ganesh A. Thakur
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, MA 02115, USA
| | - Jennifer A. Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C. Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, NSW 2050, Australia.
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12
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Anderson LL, Udoh M, Everett-Morgan D, Heblinski M, McGregor IS, Banister SD, Arnold JC. Olivetolic acid, a cannabinoid precursor in Cannabis sativa, but not CBGA methyl ester exhibits a modest anticonvulsant effect in a mouse model of Dravet syndrome. J Cannabis Res 2022; 4:2. [PMID: 34980287 PMCID: PMC8725448 DOI: 10.1186/s42238-021-00113-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/07/2021] [Indexed: 12/17/2022] Open
Abstract
Objective Cannabigerolic acid (CBGA), a precursor cannabinoid in Cannabis sativa, has recently been found to have anticonvulsant properties in the Scn1a+/- mouse model of Dravet syndrome. Poor brain penetration and chemical instability of CBGA limits its potential as an anticonvulsant therapy. Here, we examined whether CBGA methyl ester, a more stable analogue of CBGA, might have superior pharmacokinetic and anticonvulsant properties. In addition, we examined whether olivetolic acid, the biosynthetic precursor to CBGA with a truncated (des-geranyl) form, might possess minimum structural requirements for anticonvulsant activity. We also examined whether olivetolic acid and CBGA methyl ester retain activity at the epilepsy-relevant drug targets of CBGA: G-protein-coupled receptor 55 (GPR55) and T-type calcium channels. Methods The brain and plasma pharmacokinetic profiles of CBGA methyl ester and olivetolic acid were examined following 10 mg/kg intraperitoneal (i.p.) administration in mice (n = 4). The anticonvulsant potential of each was examined in male and female Scn1a+/- mice (n = 17–19) against hyperthermia-induced seizures (10–100 mg/kg, i.p.). CBGA methyl ester and olivetolic acid were also screened in vitro against T-type calcium channels and GPR55 using intracellular calcium and ERK phosphorylation assays, respectively. Results CBGA methyl ester exhibited relatively limited brain penetration (13%), although somewhat superior to that of 2% for CBGA. No anticonvulsant effects were observed against thermally induced seizures in Scn1a+/- mice. Olivetolic acid also showed poor brain penetration (1%) but had a modest anticonvulsant effect in Scn1a+/- mice increasing the thermally induced seizure temperature threshold by approximately 0.4°C at a dose of 100 mg/kg. Neither CBGA methyl ester nor olivetolic acid displayed pharmacological activity at GPR55 or T-type calcium channels. Conclusions Olivetolic acid displayed modest anticonvulsant activity against hyperthermia-induced seizures in the Scn1a+/- mouse model of Dravet syndrome despite poor brain penetration. The effect was, however, comparable to the known anticonvulsant cannabinoid cannabidiol in this model. Future studies could explore the anticonvulsant mechanism(s) of action of olivetolic acid and examine whether its anticonvulsant effect extends to other seizure types. Supplementary Information The online version contains supplementary material available at 10.1186/s42238-021-00113-w.
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Affiliation(s)
- Lyndsey L Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Michael Udoh
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Marika Heblinski
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Iain S McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Samuel D Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.,School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jonathon C Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia. .,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia. .,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.
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13
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Xu C, Zhang Y, Gozal D, Carney P. Channelopathy of Dravet Syndrome and Potential Neuroprotective Effects of Cannabidiol. J Cent Nerv Syst Dis 2021; 13:11795735211048045. [PMID: 34992485 PMCID: PMC8724990 DOI: 10.1177/11795735211048045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Dravet syndrome (DS) is a channelopathy, neurodevelopmental, epileptic encephalopathy characterized by seizures, developmental delay, and cognitive impairment that includes susceptibility to thermally induced seizures, spontaneous seizures, ataxia, circadian rhythm and sleep disorders, autistic-like behaviors, and premature death. More than 80% of DS cases are linked to mutations in genes which encode voltage-gated sodium channel subunits, SCN1A and SCN1B, which encode the Nav1.1α subunit and Nav1.1β1 subunit, respectively. There are other gene mutations encoding potassium, calcium, and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels related to DS. One-third of patients have pharmacoresistance epilepsy. DS is unresponsive to standard therapy. Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been introduced for treating DS because of its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. However, the etiological channelopathiological mechanism of DS and action mechanism of CBD on the channels are unclear. In this review, we summarize evidence of the direct and indirect action mechanism of sodium, potassium, calcium, and HCN channels in DS, especially sodium subunits. Some channels' loss-of-function or gain-of-function in inhibitory or excitatory neurons determine the balance of excitatory and inhibitory are associated with DS. A great variety of mechanisms of CBD anticonvulsant effects are focused on modulating these channels, especially sodium, calcium, and potassium channels, which will shed light on ionic channelopathy of DS and the precise molecular treatment of DS in the future.
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Affiliation(s)
- Changqing Xu
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Yumin Zhang
- Department of Anatomy, Physiology and Genetics; Department of Neuroscience, Uniformed Services University School of Medicine, Bethesda, MD, USA
| | - David Gozal
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Paul Carney
- Departments of Child Health and Neurology, School of Medicine, University of Missouri, Columbia, MO, USA
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14
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Wong JC, Butler KM, Shapiro L, Thelin JT, Mattison KA, Garber KB, Goldenberg PC, Kubendran S, Schaefer GB, Escayg A. Pathogenic in-Frame Variants in SCN8A: Expanding the Genetic Landscape of SCN8A-Associated Disease. Front Pharmacol 2021; 12:748415. [PMID: 34867351 PMCID: PMC8635767 DOI: 10.3389/fphar.2021.748415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/21/2021] [Indexed: 01/11/2023] Open
Abstract
Numerous SCN8A mutations have been identified, of which, the majority are de novo missense variants. Most mutations result in epileptic encephalopathy; however, some are associated with less severe phenotypes. Mouse models generated by knock-in of human missense SCN8A mutations exhibit seizures and a range of behavioral abnormalities. To date, there are only a few Scn8a mouse models with in-frame deletions or insertions, and notably, none of these mouse lines exhibit increased seizure susceptibility. In the current study, we report the generation and characterization of two Scn8a mouse models (ΔIRL/+ and ΔVIR/+) carrying overlapping in-frame deletions within the voltage sensor of domain 4 (DIVS4). Both mouse lines show increased seizure susceptibility and infrequent spontaneous seizures. We also describe two unrelated patients with the same in-frame SCN8A deletion in the DIV S5-S6 pore region, highlighting the clinical relevance of this class of mutations.
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Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kameryn M Butler
- Department of Human Genetics, Emory University, Atlanta, GA, United States.,Greenwood Genetic Center, Greenwood, SC, United States
| | - Lindsey Shapiro
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Jacquelyn T Thelin
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kari A Mattison
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kathryn B Garber
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Paula C Goldenberg
- Department of Pediatrics and Medical Genetics, Harvard Medical School, Boston, MA, United States
| | - Shobana Kubendran
- Department of Pediatrics, Kansas University School of Medicine-Wichita, Wichita, KS, United States
| | - G Bradley Schaefer
- University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, United States
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15
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Lo Faro V, Ten Brink JB, Snieder H, Jansonius NM, Bergen AA. Genome-wide CNV investigation suggests a role for cadherin, Wnt, and p53 pathways in primary open-angle glaucoma. BMC Genomics 2021; 22:590. [PMID: 34348663 PMCID: PMC8336345 DOI: 10.1186/s12864-021-07846-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/18/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND To investigate whether copy number variations (CNVs) are implicated in molecular mechanisms underlying primary open-angle glaucoma (POAG), we used genotype data of POAG individuals and healthy controls from two case-control studies, AGS (n = 278) and GLGS-UGLI (n = 1292). PennCNV, QuantiSNP, and cnvPartition programs were used to detect CNV. Stringent quality controls at both sample and marker levels were applied. The identified CNVs were intersected in CNV region (CNVR). After, we performed burden analysis, CNV-genome-wide association analysis, gene set overrepresentation and pathway analysis. In addition, in human eye tissues we assessed the expression of the genes lying within significant CNVRs. RESULTS We reported a statistically significant greater burden of CNVs in POAG cases compared to controls (p-value = 0,007). In common between the two cohorts, CNV-association analysis identified statistically significant CNVRs associated with POAG that span 11 genes (APC, BRCA2, COL3A1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MFSD8, NIPBL, SCN1A, SDHB, and ZDHHC11). Functional annotation and pathway analysis suggested the involvement of cadherin, Wnt signalling, and p53 pathways. CONCLUSIONS Our data suggest that CNVs may have a role in the susceptibility of POAG and they can reveal more information on the mechanism behind this disease. Additional genetic and functional studies are warranted to ascertain the contribution of CNVs in POAG.
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Affiliation(s)
- Valeria Lo Faro
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Jacoline B Ten Brink
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nomdo M Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Arthur A Bergen
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Department of Ophthalmology, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands. .,Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands.
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16
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Mantegazza M, Cestèle S, Catterall WA. Sodium channelopathies of skeletal muscle and brain. Physiol Rev 2021; 101:1633-1689. [PMID: 33769100 DOI: 10.1152/physrev.00025.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.
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Affiliation(s)
- Massimo Mantegazza
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France.,INSERM, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France
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17
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Zhao GX, Zhang Z, Cai WK, Shen ML, Wang P, He GH. Associations between CYP3A4, CYP3A5 and SCN1A polymorphisms and carbamazepine metabolism in epilepsy: A meta-analysis. Epilepsy Res 2021; 173:106615. [PMID: 33756436 DOI: 10.1016/j.eplepsyres.2021.106615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/03/2021] [Accepted: 03/10/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND OBJECTIVE CYP3A4 (rs2242480), CYP3A5 (rs776746) and SCN1A (rs3812718 and rs2298771) gene polymorphisms were previously indicated to be associated with carbamazepine (CBZ) metabolism and resistance in epilepsy. However, previous studies regarding the effects of these polymorphisms still remain controversial. Therefore, we performed a meta-analysis to evaluate whether the four polymorphisms are associated with CBZ metabolism and resistance. METHODS The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure, Chinese Science and Technique Journals Database, China Biology Medicine disc and Wan Fang Database were searched up to January 2021 for appropriate studies regarding the association of rs2242480, rs776746, rs3812718 and rs2234922 polymorphisms with CBZ metabolism and resistance. The meta-analysis was conducted by Review Manager 5.3 software. RESULTS Eighteen studies involving 2546 related epilepsy patients were included. We found that the G allele of CYP3A4 rs2242480 markedly decreased the plasma CBZ concentration in epilepsy. For CYP3A5 rs776746 polymorphism, the GG genotype (homozygote codominant model: GG vs. AA) and GG + GA genotype (dominant model: GG + GA vs. AA and recessive model: GG vs. GA + AA) were respectively found to be significantly associated with increased CBZ plasma concentration. Additionally, it was also found that the SCN1A rs3812718 A allele was significantly associated with decreased CBZ plasma concentration and increased CBZ resistance. However, no association was observed between SCN1A rs2298771 polymorphism and CBZ metabolism and resistance. CONCLUSION The CYP3A4 rs2242480, CYP3A5 rs776746 and SCN1A rs3812718 polymorphisms may play important roles in CBZ metabolism and resistance, while SCN1A rs2298771 polymorphism is not associated with CBZ in epilepsy. These findings would improve the individualized therapy of epileptic patients in clinics.
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Affiliation(s)
- Gui-Xin Zhao
- Department of Pharmacy, 920th Hospital of Joint Logistics Support Force, Kunming, 650032, China; Kunming Medical University, Kunming, 650500, China; Research Center of Clinical Pharmacology, Yunnan Provincial Hospital of Traditional Chinese Medicine, Kunming, 650021, China
| | - Zheng Zhang
- Medical Engineering Section, The 306th Hospital of PLA, Beijing, 100101, China
| | - Wen-Ke Cai
- Department of Cardio-Thoracic Surgery, 920th Hospital of Joint Logistics Support Force, Kunming, 650032, China
| | - Ming-Li Shen
- Department of Pharmacy, 920th Hospital of Joint Logistics Support Force, Kunming, 650032, China
| | - Ping Wang
- Department of Pharmacy, 920th Hospital of Joint Logistics Support Force, Kunming, 650032, China
| | - Gong-Hao He
- Department of Pharmacy, 920th Hospital of Joint Logistics Support Force, Kunming, 650032, China; Research Center of Clinical Pharmacology, Yunnan Provincial Hospital of Traditional Chinese Medicine, Kunming, 650021, China.
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18
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Jiang D, Gamal El-Din T, Zheng N, Catterall WA. Expression and purification of the cardiac sodium channel Na V1.5 for cryo-EM structure determination. Methods Enzymol 2021; 653:89-101. [PMID: 34099183 DOI: 10.1016/bs.mie.2021.01.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium channel NaV1.5 is responsible for initiating and propagating cardiac action potentials by selectively conducting Na+ into cardiomyocytes. Class-I antiarrhythmic drugs target NaV1.5 for treatment of arrhythmias. During the last few years, cryogenic electron microscopy (cryo-EM) has become a powerful technique to determine the structures of ion channels at atomic level. In order to reveal the structural features of NaV1.5 and the structural basis for its interaction with antiarrhythmic drugs by cryo-EM, NaV1.5 protein must be expressed at high levels and purified to homogeneity. In this chapter, we discuss the expression and purification of NaV1.5 in a mammalian expression system. We optimized the construct by deleting unstructured intracellular loops of rat NaV1.5 while retaining core functional regions. The resulting rNaV1.5C is fully functional and is blocked by Class-I antiarrhythmic drugs in a state-dependent manner. Protocols are presented for expressing and purifying sufficient sample of NaV1.5 for preparing cryo-EM grids. The resulting cryo-EM structure is briefly described.
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Affiliation(s)
- Daohua Jiang
- Department of Pharmacology, University of Washington, Seattle, WA, United States; Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Tamer Gamal El-Din
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA, United States; Howard Hughes Medical Institute, University of Washington, Seattle, WA, United States
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA, United States.
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19
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Han Z, Christiansen A, Meena, Liau G. Relative Quantification of Na V1.1 Protein in Mouse Brains Using a Meso Scale Discovery-Electrochemiluminescence (MSD-ECL) Method. Bio Protoc 2021; 11:e3910. [PMID: 33732797 DOI: 10.21769/bioprotoc.3910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/14/2020] [Accepted: 02/03/2021] [Indexed: 11/02/2022] Open
Abstract
Densitometric analysis is often used to quantify NaV1.1 protein on immunoblots, although the sensitivity and dilution linearity of the method are usually poor. Here we present a protocol for quantification of NaV1.1 in mouse brain tissues using a Meso Scale Discovery-Electrochemiluminescence (MSD-ECL) method. MSD-ECL is based on ELISA (enzyme-linked immunosorbent assay) and uses electrochemiluminescence to produce measurable signals. Two different antibodies are used in this assay to capture and detect NaV1.1 respectively in brain tissue lysate. The specificity of the antibodies is confirmed by Scn1a gene knock-out tissue. The calibration curve standards used in this assay were generated with mouse liver lysate spiked with mouse brain lysate, instead of using a recombinant protein. We showed that this method was qualified and used for quantification of NaV1.1 in mouse brain tissues with specificity, accuracy and precision.
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Affiliation(s)
- Zhou Han
- Stoke Therapeutics, Inc., Bedford, MA, USA
| | | | - Meena
- Stoke Therapeutics, Inc., Bedford, MA, USA
| | - Gene Liau
- Stoke Therapeutics, Inc., Bedford, MA, USA
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20
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Neurological Disorders and Risk of Arrhythmia. Int J Mol Sci 2020; 22:ijms22010188. [PMID: 33375447 PMCID: PMC7795827 DOI: 10.3390/ijms22010188] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/19/2020] [Accepted: 12/24/2020] [Indexed: 01/08/2023] Open
Abstract
Neurological disorders including depression, anxiety, post-traumatic stress disorder (PTSD), schizophrenia, autism and epilepsy are associated with an increased incidence of cardiovascular disorders and susceptibility to heart failure. The underlying molecular mechanisms that link neurological disorders and adverse cardiac function are poorly understood. Further, a lack of progress is likely due to a paucity of studies that investigate the relationship between neurological disorders and cardiac electrical activity in health and disease. Therefore, there is an important need to understand the spatiotemporal behavior of neurocardiac mechanisms. This can be advanced through the identification and validation of neurological and cardiac signaling pathways that may be adversely regulated. In this review we highlight how dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS) activity and inflammation, predispose to psychiatric disorders and cardiac dysfunction. Moreover, antipsychotic and antidepressant medications increase the risk for adverse cardiac events, mostly through the block of the human ether-a-go-go-related gene (hERG), which plays a critical role in cardiac repolarization. Therefore, understanding how neurological disorders lead to adverse cardiac ion channel remodeling is likely to have significant implications for the development of effective therapeutic interventions and helps improve the rational development of targeted therapeutics with significant clinical implications.
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21
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Sabitha KR, Shetty AK, Upadhya D. Patient-derived iPSC modeling of rare neurodevelopmental disorders: Molecular pathophysiology and prospective therapies. Neurosci Biobehav Rev 2020; 121:201-219. [PMID: 33370574 DOI: 10.1016/j.neubiorev.2020.12.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022]
Abstract
The pathological alterations that manifest during the early embryonic development due to inherited and acquired factors trigger various neurodevelopmental disorders (NDDs). Besides major NDDs, there are several rare NDDs, exhibiting specific characteristics and varying levels of severity triggered due to genetic and epigenetic anomalies. The rarity of subjects, paucity of neural tissues for detailed analysis, and the unavailability of disease-specific animal models have hampered detailed comprehension of rare NDDs, imposing heightened challenge to the medical and scientific community until a decade ago. The generation of functional neurons and glia through directed differentiation protocols for patient-derived iPSCs, CRISPR/Cas9 technology, and 3D brain organoid models have provided an excellent opportunity and vibrant resource for decoding the etiology of brain development for rare NDDs caused due to monogenic as well as polygenic disorders. The present review identifies cellular and molecular phenotypes demonstrated from patient-derived iPSCs and possible therapeutic opportunities identified for these disorders. New insights to reinforce the existing knowledge of the pathophysiology of these disorders and prospective therapeutic applications are discussed.
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Affiliation(s)
- K R Sabitha
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA.
| | - Dinesh Upadhya
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
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Schartz ND, Tenner AJ. The good, the bad, and the opportunities of the complement system in neurodegenerative disease. J Neuroinflammation 2020; 17:354. [PMID: 33239010 PMCID: PMC7690210 DOI: 10.1186/s12974-020-02024-8] [Citation(s) in RCA: 136] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023] Open
Abstract
The complement cascade is a critical effector mechanism of the innate immune system that contributes to the rapid clearance of pathogens and dead or dying cells, as well as contributing to the extent and limit of the inflammatory immune response. In addition, some of the early components of this cascade have been clearly shown to play a beneficial role in synapse elimination during the development of the nervous system, although excessive complement-mediated synaptic pruning in the adult or injured brain may be detrimental in multiple neurogenerative disorders. While many of these later studies have been in mouse models, observations consistent with this notion have been reported in human postmortem examination of brain tissue. Increasing awareness of distinct roles of C1q, the initial recognition component of the classical complement pathway, that are independent of the rest of the complement cascade, as well as the relationship with other signaling pathways of inflammation (in the periphery as well as the central nervous system), highlights the need for a thorough understanding of these molecular entities and pathways to facilitate successful therapeutic design, including target identification, disease stage for treatment, and delivery in specific neurologic disorders. Here, we review the evidence for both beneficial and detrimental effects of complement components and activation products in multiple neurodegenerative disorders. Evidence for requisite co-factors for the diverse consequences are reviewed, as well as the recent studies that support the possibility of successful pharmacological approaches to suppress excessive and detrimental complement-mediated chronic inflammation, while preserving beneficial effects of complement components, to slow the progression of neurodegenerative disease.
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Affiliation(s)
- Nicole D. Schartz
- Department of Molecular Biology and Biochemistry, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
| | - Andrea J. Tenner
- Department of Molecular Biology and Biochemistry, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
- Department of Neurobiology and Behavior, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
- Department of Pathology and Laboratory Medicine, University of California Irvine, 3205 McGaugh Hall, Irvine, CA 92697 USA
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23
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Goldman A. Structure-Function Properties in Sodium Channelopathies: Considerations for Targeted Therapy. Epilepsy Curr 2020; 20:303-305. [PMID: 34025246 PMCID: PMC7653659 DOI: 10.1177/1535759720948128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Biological Concepts in Human Sodium Channel Epilepsies and Their Relevance in
Clinical Practice Brunklaus A, Du J, Steckler F, Ghanty II, Johannesen KM, Fenger CD, Schorge S,
Baez-Nieto D, Wang H-R, Allen A, Pan JQ, Lerche H, Heyne H, Symonds JD, Zuberi SM,
Sanders S, Sheidley BR, Craiu D, Olson HE, Weckhuysen S, DeJonge P, Helbig I, Esch HV,
Tiffany B, Milh M, Isidor B, Depienne C, Poduri A, Campbel AJ, Dimidschstein J, Møller
RS, Lal D. Epilepsia. 2020;61(3):387-399. doi.org/10.1111/epi.16438 Objective: Voltage-gated sodium channels (SCNs) share similar amino acid sequence, structure,
and function. Genetic variants in the 4 human brain-expressed SCN genes
SCN1A/2A/3A/8A have been associated with heterogeneous epilepsy phenotypes and
neurodevelopmental disorders. To better understand the biology of seizure
susceptibility in SCN-related epilepsies, our aim was to determine similarities and
differences between SCN disorders, allowing us to develop a broader perspective on
precision treatment than on an individual gene level alone. Methods: We analyzed genotype–phenotype correlations in large SCN-patient cohorts and
applied variant constraint analysis to identify severe SCN disease. We examined
temporal patterns of human SCN expression and correlated functional data from in
vitro studies with clinical phenotypes across different SCN disorders. Results: Comparing 865 epilepsy patients (504 SCN1A, 140 SCN2A, 171 SCN8A, 4 SCN3A, 46 copy
number variation [CNV] cases) and analysis of 114 functional studies allowed us to
identify common patterns of presentation. All 4 epilepsy-associated SCN genes
demonstrated significant constraint in both protein truncating and missense
variation when compared to other SCN genes. We observed that age at seizure onset is
related to SCN gene expression over time. Individuals with gain-of-function
SCN2A/3A/8A missense variants or CNV duplications share similar characteristics,
most frequently present with early onset epilepsy (<3 months), and demonstrate
good response to SCN blockers (SCBs). Direct comparison of corresponding SCN
variants across different SCN subtypes illustrates that the functional effects of
variants in corresponding channel locations are similar; however, their clinical
manifestation differs, depending on their role in different types of neurons in
which they are expressed. Significance: Variant function and location within one channel can serve as a surrogate for
variant effects across related SCNs. Taking a broader view on precision treatment
suggests that in those patients with a suspected underlying genetic epilepsy
presenting with neonatal or early onset seizures (<3 months), SCBs should be
considered.
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24
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Menezes LFS, Sabiá Júnior EF, Tibery DV, Carneiro LDA, Schwartz EF. Epilepsy-Related Voltage-Gated Sodium Channelopathies: A Review. Front Pharmacol 2020; 11:1276. [PMID: 33013363 PMCID: PMC7461817 DOI: 10.3389/fphar.2020.01276] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/31/2020] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a disease characterized by abnormal brain activity and a predisposition to generate epileptic seizures, leading to neurobiological, cognitive, psychological, social, and economic impacts for the patient. There are several known causes for epilepsy; one of them is the malfunction of ion channels, resulting from mutations. Voltage-gated sodium channels (NaV) play an essential role in the generation and propagation of action potential, and malfunction caused by mutations can induce irregular neuronal activity. That said, several genetic variations in NaV channels have been described and associated with epilepsy. These mutations can affect channel kinetics, modifying channel activation, inactivation, recovery from inactivation, and/or the current window. Among the NaV subtypes related to epilepsy, NaV1.1 is doubtless the most relevant, with more than 1500 mutations described. Truncation and missense mutations are the most observed alterations. In addition, several studies have already related mutated NaV channels with the electrophysiological functioning of the channel, aiming to correlate with the epilepsy phenotype. The present review provides an overview of studies on epilepsy-associated mutated human NaV1.1, NaV1.2, NaV1.3, NaV1.6, and NaV1.7.
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Affiliation(s)
- Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Elias Ferreira Sabiá Júnior
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Lilian Dos Anjos Carneiro
- Faculdade de Medicina, Centro Universitário Euro Americano, Brasília, Brazil.,Faculdade de Medicina, Centro Universitário do Planalto Central, Brasília, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
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Gavrilovici C, Jiang Y, Kiroski I, Teskey GC, Rho JM, Nguyen MD. Postnatal Role of the Cytoskeleton in Adult Epileptogenesis. Cereb Cortex Commun 2020; 1:tgaa024. [PMID: 32864616 PMCID: PMC7446231 DOI: 10.1093/texcom/tgaa024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 02/07/2023] Open
Abstract
Mutations in cytoskeletal proteins can cause early infantile and childhood epilepsies by misplacing newly born neurons and altering neuronal connectivity. In the adult epileptic brain, cytoskeletal disruption is often viewed as being secondary to aberrant neuronal activity and/or death, and hence simply represents an epiphenomenon. Here, we review the emerging evidence collected in animal models and human studies implicating the cytoskeleton as a potential causative factor in adult epileptogenesis. Based on the emerging evidence, we propose that cytoskeletal disruption may be an important pathogenic mechanism in the mature epileptic brain.
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Affiliation(s)
- Cezar Gavrilovici
- Departments of Neurosciences & Pediatrics, University of California San Diego, Rady Children’s Hospital San Diego, San Diego, CA 92123, USA
| | - Yulan Jiang
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - Ivana Kiroski
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - G Campbell Teskey
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - Jong M Rho
- Departments of Neurosciences & Pediatrics, University of California San Diego, Rady Children’s Hospital San Diego, San Diego, CA 92123, USA
| | - Minh Dang Nguyen
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
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26
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D'Adamo MC, Liantonio A, Conte E, Pessia M, Imbrici P. Ion Channels Involvement in Neurodevelopmental Disorders. Neuroscience 2020; 440:337-359. [PMID: 32473276 DOI: 10.1016/j.neuroscience.2020.05.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/14/2022]
Abstract
Inherited and sporadic mutations in genes encoding for brain ion channels, affecting membrane expression or biophysical properties, have been associated with neurodevelopmental disorders characterized by epilepsy, cognitive and behavioral deficits with significant phenotypic and genetic heterogeneity. Over the years, the screening of a growing number of patients and the functional characterization of newly identified mutations in ion channels genes allowed to recognize new phenotypes and to widen the clinical spectrum of known diseases. Furthermore, advancements in understanding disease pathogenesis at atomic level or using patient-derived iPSCs and animal models have been pivotal to orient therapeutic intervention and to put the basis for the development of novel pharmacological options for drug-resistant disorders. In this review we will discuss major improvements and critical issues concerning neurodevelopmental disorders caused by dysfunctions in brain sodium, potassium, calcium, chloride and ligand-gated ion channels.
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Affiliation(s)
- Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | | | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta; Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy.
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27
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Rodent genetic models of neurodevelopmental disorders and epilepsy. Eur J Paediatr Neurol 2020; 24:66-69. [PMID: 31870697 DOI: 10.1016/j.ejpn.2019.12.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/06/2019] [Indexed: 11/23/2022]
Abstract
Neurodevelopmental disorders (NDDs) are characterised by cognitive, social and motor deficits and are highly comorbid with intractable epilepsies. Through advances in genetic sequencing technologies a vast number of genes have been implicated in NDDs. State-of-the-art gene-editing techniques have led to the generation of hundreds of mouse models of NDDs. As an example, rodent models of Rett and Dravet syndromes as well as the syndromes caused by mutations in CDKL5 and Syngap1 display cognitive deficits in conjunction with seizure phenotypes. These models allow researchers to understand the underlying mechanisms as well as develop novel treatment strategies that can potentially be translated to the clinic. Furthermore, it may be possible to gain insights into the contribution of epilepsy to the progression of cognitive, social and motor phenotypes in NDDs.
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28
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Changes in Calcium Homeostasis and Gene Expression Implicated in Epilepsy in Hippocampi of Mice Overexpressing ORAI1. Int J Mol Sci 2019; 20:ijms20225539. [PMID: 31698854 PMCID: PMC6888010 DOI: 10.3390/ijms20225539] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/04/2019] [Accepted: 11/04/2019] [Indexed: 12/21/2022] Open
Abstract
Previously, we showed that the overexpression of ORAI1 calcium channel in neurons of murine brain led to spontaneous occurrence of seizure-like events in aged animals of transgenic line FVB/NJ-Tg(ORAI1)Ibd (Nencki Institute of Experimental Biology). We aimed to identify the mechanism that is responsible for this phenomenon. Using a modified Ca2+-addback assay in the CA1 region of acute hippocampal slices and FURA-2 acetomethyl ester (AM) Ca2+ indicator, we found that overexpression of ORAI1 in neurons led to altered Ca2+ response. Next, by RNA sequencing (RNAseq) we identified a set of genes, whose expression was changed in our transgenic animals. These data were validated using customized real-time PCR assays and digital droplet PCR (ddPCR) ddPCR. Using real-time PCR, up-regulation of hairy and enhancer of split-5 (Hes-5) gene and down-regulation of aristaless related homeobox (Arx), doublecortin-like kinase 1 (Dclk1), and cyclin-dependent kinase-like 5 (Cdkl5, also known as serine/threonine kinase 9 (Stk9)) genes were found. Digital droplet PCR (ddPCR) analysis revealed down-regulation of Arx. In humans, ARX, DCLK1, and CDLK5 were shown to be mutated in some rare epilepsy-associated disorders. We conclude that the occurrence of seizure-like events in aged mice overexpressing ORAI1 might be due to the down-regulation of Arx, and possibly of Cdkl5 and Dclk1 genes.
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29
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Kiernan MC, Bostock H, Park SB, Kaji R, Krarup C, Krishnan AV, Kuwabara S, Lin CSY, Misawa S, Moldovan M, Sung J, Vucic S, Wainger BJ, Waxman S, Burke D. Measurement of axonal excitability: Consensus guidelines. Clin Neurophysiol 2019; 131:308-323. [PMID: 31471200 DOI: 10.1016/j.clinph.2019.07.023] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 12/12/2022]
Abstract
Measurement of axonal excitability provides an in vivo indication of the properties of the nerve membrane and of the ion channels expressed on these axons. Axonal excitability techniques have been utilised to investigate the pathophysiological mechanisms underlying neurological diseases. This document presents guidelines derived for such studies, based on a consensus of international experts, and highlights the potential difficulties when interpreting abnormalities in diseased axons. The present manuscript provides a state-of-the-art review of the findings of axonal excitability studies and their interpretation, in addition to suggesting guidelines for the optimal performance of excitability studies.
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Affiliation(s)
- Matthew C Kiernan
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney 2006, Australia.
| | - Hugh Bostock
- UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom
| | - Susanna B Park
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney 2006, Australia
| | - Ryuji Kaji
- National Utano Hospital, 8-Narutaki Ondoyamacho, Ukyoku, Kyoto 616-8255, Japan
| | - Christian Krarup
- Department of Neuroscience, University of Copenhagen and Department of Clinical Neurophysiology, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Arun V Krishnan
- Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Japan
| | - Cindy Shin-Yi Lin
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney 2006, Australia
| | - Sonoko Misawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Japan
| | - Mihai Moldovan
- Department of Neuroscience, University of Copenhagen and Department of Clinical Neurophysiology, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Jiaying Sung
- Taipei Medical University, Wanfang Hospital, Taipei, Taiwan
| | - Steve Vucic
- Department of Neurology, Westmead Hospital, Western Clinical School, University of Sydney, Australia
| | - Brian J Wainger
- Department of Neurology and Anesthesiology, Critical Care & Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Stephen Waxman
- Department of Neurology, Yale Medical School, New Haven, CT 06510, USA; Neurorehabilitation Research Center, Veterans Affairs Hospital, West Haven, CT 06516, USA
| | - David Burke
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney 2006, Australia
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30
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Haworth AS, Brackenbury WJ. Emerging roles for multifunctional ion channel auxiliary subunits in cancer. Cell Calcium 2019; 80:125-140. [PMID: 31071485 PMCID: PMC6553682 DOI: 10.1016/j.ceca.2019.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 02/07/2023]
Abstract
Several superfamilies of plasma membrane channels which regulate transmembrane ion flux have also been shown to regulate a multitude of cellular processes, including proliferation and migration. Ion channels are typically multimeric complexes consisting of conducting subunits and auxiliary, non-conducting subunits. Auxiliary subunits modulate the function of conducting subunits and have putative non-conducting roles, further expanding the repertoire of cellular processes governed by ion channel complexes to processes such as transcellular adhesion and gene transcription. Given this expansive influence of ion channels on cellular behaviour it is perhaps no surprise that aberrant ion channel expression is a common occurrence in cancer. This review will focus on the conducting and non-conducting roles of the auxiliary subunits of various Ca2+, K+, Na+ and Cl- channels and the burgeoning evidence linking such auxiliary subunits to cancer. Several subunits are upregulated (e.g. Cavβ, Cavγ) and downregulated (e.g. Kvβ) in cancer, while other subunits have been functionally implicated as oncogenes (e.g. Navβ1, Cavα2δ1) and tumour suppressor genes (e.g. CLCA2, KCNE2, BKγ1) based on in vivo studies. The strengthening link between ion channel auxiliary subunits and cancer has exposed these subunits as potential biomarkers and therapeutic targets. However further mechanistic understanding is required into how these subunits contribute to tumour progression before their therapeutic potential can be fully realised.
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Affiliation(s)
- Alexander S Haworth
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, Heslington, York, YO10 5DD, UK
| | - William J Brackenbury
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, Heslington, York, YO10 5DD, UK.
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31
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Vgontzas A, Renthal W. Introduction to Neurogenetics. Am J Med 2019; 132:142-152. [PMID: 30098310 DOI: 10.1016/j.amjmed.2018.07.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 07/26/2018] [Accepted: 07/26/2018] [Indexed: 12/17/2022]
Abstract
Genetic variation can directly cause or increase susceptibility to neurologic diseases. An explosion of new genetic technologies has enabled the characterization of specific genes responsible for many neurologic diseases and has provided fundamentally new insight into their pathophysiology. These advancements, along with recent breakthroughs in gene therapy, are beginning to result in the translation of an individual's genetic sequence into targeted treatment strategies. This review aims to introduce key genetic concepts and to illustrate how these principles apply in cases of rare, single-gene neurologic diseases as well as more common, polygenic diseases that are encountered frequently in clinical practice.
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Affiliation(s)
- Angeliki Vgontzas
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.
| | - William Renthal
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
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32
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Carvill GL, Engel KL, Ramamurthy A, Cochran JN, Roovers J, Stamberger H, Lim N, Schneider AL, Hollingsworth G, Holder DH, Regan BM, Lawlor J, Lagae L, Ceulemans B, Bebin EM, Nguyen J, Barsh GS, Weckhuysen S, Meisler M, Berkovic SF, De Jonghe P, Scheffer IE, Myers RM, Cooper GM, Mefford HC, Striano P, Zara F, Helbig I, Møller RS, von Spiczak S, Muhle H, Caglayan H, Sterbova K, Craiu D, Hoffman D, Lehesjoki AE, Selmer K, Depienne C, Lemke J, Marini C, Guerrini R, Neubauer B, Talvik T, Leguern E, de Jonghe P, Weckhuysen S. Aberrant Inclusion of a Poison Exon Causes Dravet Syndrome and Related SCN1A-Associated Genetic Epilepsies. Am J Hum Genet 2018; 103:1022-1029. [PMID: 30526861 DOI: 10.1016/j.ajhg.2018.10.023] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/25/2018] [Indexed: 12/30/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are a group of severe epilepsies characterized by refractory seizures and developmental impairment. Sequencing approaches have identified causal genetic variants in only about 50% of individuals with DEEs.1-3 This suggests that unknown genetic etiologies exist, potentially in the ∼98% of human genomes not covered by exome sequencing (ES). Here we describe seven likely pathogenic variants in regions outside of the annotated coding exons of the most frequently implicated epilepsy gene, SCN1A, encoding the alpha-1 sodium channel subunit. We provide evidence that five of these variants promote inclusion of a "poison" exon that leads to reduced amounts of full-length SCN1A protein. This mechanism is likely to be broadly relevant to human disease; transcriptome studies have revealed hundreds of poison exons,4,5 including some present within genes encoding other sodium channels and in genes involved in neurodevelopment more broadly.6 Future research on the mechanisms that govern neuronal-specific splicing behavior might allow researchers to co-opt this system for RNA therapeutics.
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Jiang T, Shen Y, Chen H, Yuan Z, Mao S, Gao F. Clinical and molecular analysis of epilepsy-related genes in patients with Dravet syndrome. Medicine (Baltimore) 2018; 97:e13565. [PMID: 30558019 PMCID: PMC6320057 DOI: 10.1097/md.0000000000013565] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Dravet syndrome is considered to be one of the most severe types of genetic epilepsy. Mutations in SCN1A gene have been found to be responsible for at least 80% of patients with Dravet syndrome, and 90% of these mutations arise de novo. The variable clinical phenotype is commonly observed among these patients with SCN1A mutations, suggesting that genetic modifiers may influence the phenotypic expression of Dravet syndrome. In the present study, we described the clinical, pathological, and molecular characteristics of 13 Han Chinese pedigrees clinically diagnosed with Dravet syndrome. By targeted-exome sequencing, bioinformatics analysis and Sanger sequencing verification, 11 variants were identified in SCN1A gene among 11 pedigrees including 7 missense mutations, 2 splice site mutations, and 2 frameshift mutations (9 novel variants and 2 reported mutations). Particularly, 2 of these Dravet syndrome patients with SCN1A variants also harbored SCN9A, KCNQ2, or SLC6A8 variants. In addition, 2 subjects were failed to detect any pathogenic mutations in SCN1A and other epilepsy-related genes. These data suggested that SCN1A variants account for about 84.6% of Dravet syndrome in our cohort. This study expanded the mutational spectrum for the SCN1A gene, and also provided clinical and genetic evidence for the hypothesis that genetic modifiers may contribute to the variable manifestation of Dravet syndrome patients with SCN1A mutations. Thus, targeted-exome sequencing will make it possible to detect the interactions of epilepsy-related genes and reveal their modification on the severity of SCN1A mutation-related Dravet syndrome.
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Affiliation(s)
- TieJia Jiang
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Yaping Shen
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Huai Chen
- Hangzhou Red Cross Hospital, Hangzhou, China
| | - Zhefeng Yuan
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Shanshan Mao
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Feng Gao
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
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Nickel K, Tebartz van Elst L, Domschke K, Gläser B, Stock F, Endres D, Maier S, Riedel A. Heterozygous deletion of SCN2A and SCN3A in a patient with autism spectrum disorder and Tourette syndrome: a case report. BMC Psychiatry 2018; 18:248. [PMID: 30071822 PMCID: PMC6090917 DOI: 10.1186/s12888-018-1822-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 07/19/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Mutations in voltage-gated sodium channel (SCN) genes are supposed to be of importance in the etiology of psychiatric and neurological diseases, in particular in the etiology of seizures. Previous studies report a potential susceptibility region at the chromosomal locus 2q including SCN1A, SCN2A and SCN3A genes for autism spectrum disorder (ASD). To date, there is no previous description of a patient with comorbid ASD and Tourette syndrome showing a deletion containing SCN2A and SCN3A. CASE PRESENTATION We present the unique complex case of a 28-year-old male patient suffering from developmental retardation and exhibiting a range of behavioral traits since birth. He received the diagnoses of ASD (in early childhood) and of Tourette syndrome (in adulthood) according to ICD-10 and DSM-5 criteria. Investigations of underlying genetic factors yielded a heterozygous microdeletion of approximately 719 kb at 2q24.3 leading to a deletion encompassing the five genes SCN2A (exon 1 to intron 14-15), SCN3A, GRB14 (exon 1 to intron 2-3), COBLL1 and SCL38A11. CONCLUSIONS We discuss the association of SCN2A, SCN3A, GRB14, COBLL1 and SCL38A11 deletions with ASD and Tourette syndrome and possible implications for treatment.
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Affiliation(s)
- Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104, Freiburg, Germany.
| | - Ludger Tebartz van Elst
- grid.5963.9Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104 Freiburg, Germany
| | - Katharina Domschke
- grid.5963.9Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104 Freiburg, Germany
| | - Birgitta Gläser
- grid.5963.9Institute of Human Genetics, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Straße 33, D-79106 Freiburg, Germany
| | - Friedrich Stock
- grid.5963.9Institute of Human Genetics, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Straße 33, D-79106 Freiburg, Germany
| | - Dominique Endres
- grid.5963.9Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104 Freiburg, Germany
| | - Simon Maier
- grid.5963.9Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104 Freiburg, Germany
| | - Andreas Riedel
- grid.5963.9Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstraße 5, D-79104 Freiburg, Germany
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Dhifallah S, Lancaster E, Merrill S, Leroudier N, Mantegazza M, Cestèle S. Gain of Function for the SCN1A/hNa v1.1-L1670W Mutation Responsible for Familial Hemiplegic Migraine. Front Mol Neurosci 2018; 11:232. [PMID: 30038559 PMCID: PMC6046441 DOI: 10.3389/fnmol.2018.00232] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/12/2018] [Indexed: 12/21/2022] Open
Abstract
The SCN1A gene encodes for the voltage-dependent Nav1.1 Na+ channel, an isoform mainly expressed in GABAergic neurons that is the target of hundreds of epileptogenic mutations. More recently, it has been shown that the SCN1A gene is also the target of mutations responsible for familial hemiplegic migraine (FHM-3), a rare autosomal dominant subtype of migraine with aura. Studies of these mutations indicate that they induce gain of function of the channel. Surprisingly, the mutation L1649Q responsible for pure FHM-3 showed a complete loss of function, but, when partially rescued it induced an overall gain of function because of modification of the gating properties of the mutant channel. Here, we report the characterization of the L1670W SCN1A mutation that has been previously identified in a Chinese family with pure FHM-3, and that we have identified also in a Caucasian American family with pure FHM-3. Notably, one patient in our family had severe neurological deterioration after brain radiation for cancer treatment. Functional analysis of L1670W reveals that the mutation is responsible for folding/trafficking defects and, when they are rescued by incubation at lower temperature or by expression in neurons, modifications of the gating properties lead to an overall gain of function. Therefore, L1670W is the second mutation responsible for FHM-3 with this pathophysiological mechanism, showing that it may be a recurrent mechanism for Nav1.1 hemiplegic migraine mutations.
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Affiliation(s)
- Sandra Dhifallah
- Université Côte d'Azur, CNRS UMR 7275, INSERM, IPMC, Valbonne, France
| | - Eric Lancaster
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Shana Merrill
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | | | | | - Sandrine Cestèle
- Université Côte d'Azur, CNRS UMR 7275, INSERM, IPMC, Valbonne, France
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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] [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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Zhi H, Wu C, Yang Z. SCN1A rs3812718 polymorphism is associated with epilepsy: An updated meta-analysis. Epilepsy Res 2018; 142:81-87. [DOI: 10.1016/j.eplepsyres.2018.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/10/2018] [Accepted: 03/24/2018] [Indexed: 12/18/2022]
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Feng W, Mei S, Zhu L, Yu Y, Yang W, Gao B, Wu X, Zhao Z, Fang F. Effects of UGT2B7, SCN1A and CYP3A4 on the therapeutic response of sodium valproate treatment in children with generalized seizures. Seizure 2018; 58:96-100. [PMID: 29679912 DOI: 10.1016/j.seizure.2018.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 03/11/2018] [Accepted: 04/08/2018] [Indexed: 11/28/2022] Open
Abstract
PURPOSE This study aims to evaluate the associations between genetic polymorphisms and the effect of sodium valproate (VPA) therapy in children with generalized seizures. METHODS A total of 174 children with generalized seizures on VPA therapy were enrolled. Steady-state trough plasma concentrations of VPA were analyzed. Seventy-six single nucleotide polymorphisms involved in the absorption, metabolism, transport, and target receptor of VPA were identified, and their associations with the therapeutic effect (seizure reduction) were evaluated using logistic regression adjusted by various influence factors. RESULTS rs7668282 (UGT2B7, T > C, OR = 2.67, 95% CI: 1.19 to 5.91, P = 0.017) was more prevalent in drug-resistant patients than drug-responsive patients. rs2242480 (CYP3A4, C > T, OR = 0.27, 95% CI: 0.095 to 0.79, P = 0.017) and rs10188577 (SCN1A, T > C, OR = 0.40, 95% CI: 0.17 to 0.94, P = 0.035) were more prevalent in drug-responsive patients compared to drug-resistant patients. CONCLUSION In children with generalized seizures on VPA therapy, polymorphisms of UGT2B7, CYP3A4, and SCN1A genes were associated with seizure reduction. Larger studies are warranted to corroborate the results.
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Affiliation(s)
- Weixing Feng
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China; Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Shenghui Mei
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China; Department of Clinical Pharmacology, College of Pharmaceutical Sciences, Capital Medical University, Beijing 100045, China
| | - Leting Zhu
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Yazhen Yu
- Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Weili Yang
- Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Baoqin Gao
- Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Xiaojuan Wu
- Department of Pediatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Zhigang Zhao
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China; Department of Clinical Pharmacology, College of Pharmaceutical Sciences, Capital Medical University, Beijing 100045, China.
| | - Fang Fang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China.
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Kim HW, Quan Z, Kim YB, Cheong E, Kim HD, Cho M, Jang J, Yoo YR, Lee JS, Kim JH, Kim YI, Kim DS, Kang HC. Differential effects on sodium current impairments by distinct SCN1A mutations in GABAergic neurons derived from Dravet syndrome patients. Brain Dev 2018; 40:287-298. [PMID: 29295803 DOI: 10.1016/j.braindev.2017.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND We investigated how two distinct mutations in SCN1A differentially affect electrophysiological properties of the patient-derived GABAergic neurons and clinical severities in two Dravet syndrome (DS) patients. MATERIALS AND METHODS We established induced pluripotent stem cells from two DS patients with different mutations in SCN1A and subsequently differentiated them into forebrain GABAergic neurons. Functionality of differentiated GABAergic neurons was examined by electrophysiological recordings. RESULTS DS-1 patient had a missense mutation, c.4261G > T [GenBank: NM_006920.4] and DS-2 patient had a nonsense frameshift mutation, c.3576_3580 del TCAAA [GenBank: NM_006920.4]. Clinically, contrary to our expectations, DS-1 patient had more severe symptoms including frequency of seizure episodes and the extent of intellectual ability penetration than DS-2 patient. Electrophysiologic recordings showed significantly lower sodium current density and reduced action potential frequency at strong current injection (>60 pA) in GABAergic neurons derived from both. Intriguingly, unique genetic alterations of SCN1A differentially impacted electrophysiological impairment of the neurons, and the impairment's extent corresponded with the symptomatic severity of the donor from which the iPSCs were derived. CONCLUSION Our results suggest the possibility that patient-derived iPSCs may provide a reliable in vitro system that reflects clinical severities in individuals with DS.
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Affiliation(s)
- Hyun Woo Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Zhejiu Quan
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Young-Beom Kim
- Department of Physiology, Korea University College of Medicine, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Eunji Cheong
- Department of Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Minjung Cho
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jiho Jang
- Department of Physiology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Young Rang Yoo
- Department of Biotechnology, BK21 PLUS Project, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Ji Hun Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Yang In Kim
- Department of Physiology, Korea University College of Medicine, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Dae-Sung Kim
- Department of Biotechnology, BK21 PLUS Project, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea; Department of Pediatrics, Korea University College of Medicine, Guro Hospital, 97 Gurodong-gil, Guro-gu, Seoul 08308, Republic of Korea.
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Republic of Korea.
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Yang C, Hua Y, Zhang W, Xu J, Xu L, Gao F, Jiang P. Variable epilepsy phenotypes associated with heterozygous mutation in the SCN9A gene: report of two cases. Neurol Sci 2018; 39:1113-1115. [PMID: 29500686 DOI: 10.1007/s10072-018-3300-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/22/2018] [Indexed: 11/25/2022]
Abstract
Up to now, SCN9A mutations encoding Nav1.7 have been limited to inherited pain syndromes. A few of pathogenic SCN9A mutations with or without SCN1A mutations have been identified in epileptic patients. Here, we report two heterozygous SCN9A mutations with no SCN1A mutations, which are associated with variable epilepsy phenotypes and explored the possibility of SCN9A contributing to a multifactorial etiology for epilepsy. Our findings suggest that the two SCN9A mutations (c.980G>A chr2:167149868 p.G327E; c.5702_5706del chr2:167055410 p.I1901fs) should be regarded as pathogenic mutations. Two heterozygous mutations of SCN9A are associated with a wide clinical spectrum of seizure phenotypes including simple febrile seizures, afebrile seizures, generalized tonic-clonic seizure, myoclonic or tonic seizures, and focal clonic seizures. Patients with deletion mutations tend to be associated with more severe seizure type than missense mutations.
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Affiliation(s)
- Cuiwei Yang
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Yi Hua
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Weiqin Zhang
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Jialu Xu
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Lu Xu
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Feng Gao
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China
| | - Peifang Jiang
- Department of Neurology, Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, People's Republic of China.
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Refractory focal epilepsy in a paediatric patient with primary familial brain calcification. Seizure 2018; 56:50-52. [PMID: 29448117 DOI: 10.1016/j.seizure.2018.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 09/09/2017] [Accepted: 02/01/2018] [Indexed: 12/17/2022] Open
Abstract
Primary familial brain calcification (PFBC), otherwise known as Fahr's disease, is a rare autosomal dominant condition with manifestations of movement disorders, neuropsychiatric symptoms, and epilepsy in a minority of PFBC patients. The clinical presentation of epilepsy in PFBC has not been described in detail. We present a paediatric patient with PFBC and refractory focal epilepsy based on seizure semiology and ictal EEG, but with generalized interictal EEG abnormalities. The patient was found to have a SLC20A2 mutation known to be pathogenic in PFBC, as well as a variant of unknown significance in SCN2A. This case demonstrates that the ictal EEG is important for accurately classifying epilepsy in affected subjects with PFBC. Further, epilepsy in PFBC may be a polygenic disorder.
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Ye M, Yang J, Tian C, Zhu Q, Yin L, Jiang S, Yang M, Shu Y. Differential roles of Na V1.2 and Na V1.6 in regulating neuronal excitability at febrile temperature and distinct contributions to febrile seizures. Sci Rep 2018; 8:753. [PMID: 29335582 PMCID: PMC5768682 DOI: 10.1038/s41598-017-17344-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 11/20/2017] [Indexed: 01/25/2023] Open
Abstract
Dysregulation of voltage-gated sodium channels (VGSCs) is associated with multiple clinical disorders, including febrile seizures (FS). The contribution of different sodium channel subtypes to environmentally triggered seizures is not well understood. Here we demonstrate that somatic and axonal sodium channels primarily mediated through NaV1.2 and NaV1.6 subtypes, respectively, behave differentially at FT, and might play distinct roles in FS generation. In contrast to sodium channels on the main axonal trunk, somatic ones are more resistant to inactivation and display significantly augmented currents, faster gating rates and kinetics of recovery from inactivation at FT, features that promote neuronal excitabilities. Pharmacological inhibition of NaV1.2 by Phrixotoxin-3 (PTx3) suppressed FT-induced neuronal hyperexcitability in brain slice, while up-regulation of NaV1.2 as in NaV1.6 knockout mice showed an opposite effect. Consistently, NaV1.6 knockout mice were more susceptible to FS, exhibiting much lower temperature threshold and shorter onset latency than wildtype mice. Neuron modeling further suggests that NaV1.2 is the major subtype mediating FT-induced neuronal hyperexcitability, and predicts potential outcomes of alterations in sodium channel subtype composition. Together, these data reveal a role of native NaV1.2 on neuronal excitability at FT and its important contribution to FS pathogenesis.
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Affiliation(s)
- Mingyu Ye
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
| | - Jun Yang
- State Key Laboratory of Cognitive Neuroscience and Learning, School of Brain and Cognitive Sciences, the Collaborative Innovation Center for Brain Science, Beijing Normal University, Beijing, China
| | - Cuiping Tian
- iHuman Institute, ShanghaiTech University, Shanghai, China
| | - Qiyu Zhu
- Brain Institute, College of Pharmaceutical Sciences, Capital Medical University, Beijing, China
| | - Luping Yin
- State Key Laboratory of Cognitive Neuroscience and Learning, School of Brain and Cognitive Sciences, the Collaborative Innovation Center for Brain Science, Beijing Normal University, Beijing, China
| | - Shan Jiang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Mingpo Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yousheng Shu
- State Key Laboratory of Cognitive Neuroscience and Learning, School of Brain and Cognitive Sciences, the Collaborative Innovation Center for Brain Science, Beijing Normal University, Beijing, China.
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Xiang J, Wen F, Zhang L, Zhou Y. FOXD3 inhibits SCN2A gene transcription in intractable epilepsy cell models. Exp Neurol 2017; 302:14-21. [PMID: 29288635 DOI: 10.1016/j.expneurol.2017.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 12/20/2017] [Accepted: 12/26/2017] [Indexed: 12/28/2022]
Abstract
The expression of sodium voltage-gated channel alpha subunit 2 (SCN2A) is closely related to the development of epilepsy. This study investigated regulatory element of the SCN2A gene involved in epilepsy. An intractable epilepsy cell model was constructed using hippocampal primary neurons and the SH-SY5Y cell line. SCN2A protein and gene expression in cells as well as the level of lactic acid dehydrogenase (LDH) in the cell culture supernatants was detected. Potential regulatory factors of SCN2A and its upstream regulatory elements were identified using the dual-luciferase reporter assay. Finally, the role of the hypothetical transcription factor in epilepsy was examined by using its small interfering RNA (siRNA). Results found that levels of LDH and expression of the hypothetical transcription factor, Forkhead box D3 (FOXD3), was both increased in the model cells, whereas that of SCN2A was decreased. The results of dual-luciferase reporter assays revealed that an upstream region of SCN2A gene spanning from nucleotides -1617 to -1470 was a transcription factor binding region and a trans-acting factor role of FOXD3 was identified in the core region (GGCAAAATTAT). Then the FOXD3 binding site was further verified by the chromatin immunoprecipitation (ChIP) assay and electrophoretic mobility shift assay (EMSA). After SH-SY5Y cells were transfected with FOXD3 siRNA, the release of LDH into culture supernatants and the LDH expression levels in cells were significantly decreased. SCN2A expression in model cells was increased by knockdown of FOXD3. Therefore, this study demonstrated that FOXD3 is a trans-acting factor of SCN2A, and this mechanism may play a role in cell injury after epilepsy.
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Affiliation(s)
- Jun Xiang
- Department of Neurosurgery, The Second Xiang-Ya Hospital of Central South University, Changsha 410011, Hunan Province, China.
| | - Fang Wen
- Neurology Electroencephalogram Room of Neurology Department, The Second Xiang-Ya Hospital of Central South University, Changsha 410011, Hunan Province, China
| | - Lingyun Zhang
- Department of Neurosurgery, The Second Xiang-Ya Hospital of Central South University, Changsha 410011, Hunan Province, China
| | - Yu Zhou
- Department of Neurosurgery, The Second Xiang-Ya Hospital of Central South University, Changsha 410011, Hunan Province, China
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Hull JM, Isom LL. Voltage-gated sodium channel β subunits: The power outside the pore in brain development and disease. Neuropharmacology 2017; 132:43-57. [PMID: 28927993 DOI: 10.1016/j.neuropharm.2017.09.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/19/2017] [Accepted: 09/11/2017] [Indexed: 12/19/2022]
Abstract
Voltage gated sodium channels (VGSCs) were first identified in terms of their role in the upstroke of the action potential. The underlying proteins were later identified as saxitoxin and scorpion toxin receptors consisting of α and β subunits. We now know that VGSCs are heterotrimeric complexes consisting of a single pore forming α subunit joined by two β subunits; a noncovalently linked β1 or β3 and a covalently linked β2 or β4 subunit. VGSC α subunits contain all the machinery necessary for channel cell surface expression, ion conduction, voltage sensing, gating, and inactivation, in one central, polytopic, transmembrane protein. VGSC β subunits are more than simple accessories to α subunits. In the more than two decades since the original cloning of β1, our knowledge of their roles in physiology and pathophysiology has expanded immensely. VGSC β subunits are multifunctional. They confer unique gating mechanisms, regulate cellular excitability, affect brain development, confer distinct channel pharmacology, and have functions that are independent of the α subunits. The vast array of functions of these proteins stems from their special station in the channelome: being the only known constituents that are cell adhesion and intra/extracellular signaling molecules in addition to being part of channel complexes. This functional trifecta and how it goes awry demonstrates the power outside the pore in ion channel signaling complexes, broadening the term channelopathy beyond defects in ion conduction. This article is part of the Special Issue entitled 'Channelopathies.'
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Affiliation(s)
- Jacob M Hull
- Neuroscience Program and Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Lori L Isom
- Neuroscience Program and Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States.
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45
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Modulation of Abnormal Sodium Channel Currents in Heart and Brain: Hope for SUDEP Prevention and Seizure Reduction. Epilepsy Curr 2017; 17:306-310. [PMID: 29225548 DOI: 10.5698/1535-7597.17.5.306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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46
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Need AC, Goldstein DB. Neuropsychiatric genomics in precision medicine: diagnostics, gene discovery, and translation. DIALOGUES IN CLINICAL NEUROSCIENCE 2017. [PMID: 27757059 PMCID: PMC5067142 DOI: 10.31887/dcns.2016.18.3/aneed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Only a few years after its development, next-generation sequencing is rapidly becoming an essential part of clinical care for patients with serious neurological conditions, especially in the diagnosis of early-onset and severe presentations. Beyond this diagnostic role, there has been an explosion in definitive gene discovery in a range of neuropsychiatric diseases. This is providing new pointers to underlying disease biology and is beginning to outline a new framework for genetic stratification of neuropsychiatric disease, with clear relevance to both individual treatment optimization and clinical trial design. Here, we outline these developments and chart the expected impact on the treatment of neurological, neurodevelopmental, and psychiatric disease.
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Affiliation(s)
- Anna C Need
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, W12 ONN, UK
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY, 10032, USA
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Peng Q, Schork NJ, Wilhelmsen KC, Ehlers CL. Whole genome sequence association and ancestry-informed polygenic profile of EEG alpha in a Native American population. Am J Med Genet B Neuropsychiatr Genet 2017; 174:435-450. [PMID: 28436151 PMCID: PMC5435561 DOI: 10.1002/ajmg.b.32533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 02/06/2017] [Indexed: 12/18/2022]
Abstract
EEG alpha activity is the dominant oscillation in most adult humans, is highly heritable, and has been associated with a number of cognitive functions. Two EEG phenotypes, low- and high-voltage alpha (LVA & HVA), have been demonstrated to have high heritabilities. They have different prevalence depending on a population's ancestral origins. In the present study we assessed the influence of ancestry admixture on EEG alpha power, and conducted a whole genome sequencing association analysis and an ancestry-informed polygenic study on those phenotypes in a Native American (NA) population that has a high prevalence of LVA. Seven common variants, in LD with each other upstream from gene ASIC2, reached genome-wide significance (p = 2 × 10-8 ) having a positive association with alpha voltage. They had lower minor allele frequencies in the NAs than in a global population sample. Overall correlations between lower degrees of NA (higher degree European) ancestry and HVA, and higher degrees of NA and LVA were also found. Additionally a rare-variant gene-based study identified gene TIA1 being negatively associated with LVA. Approximately 3% of SNPs exhibited a 15-fold enrichment that explained nearly half of the total SNP-heritability for EEG alpha. These regions showed the most significant anti-correlations between NA ancestry and alpha voltage, and were enriched for genes and pathways mediating cognitive functions. Our findings suggested that these regions likely harbor causal variants for HVA, and lacking of such variants could explain the high prevalence of LVA in this NA population, possibly illuminating the ancestral origin and genetic basis for EEG alpha.
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Affiliation(s)
- Qian Peng
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, California 92037 USA
- Department of Human Biology, J. Craig Venter Institute, La Jolla, California 92037 USA
| | - Nicholas J. Schork
- Department of Human Biology, J. Craig Venter Institute, La Jolla, California 92037 USA
| | - Kirk C. Wilhelmsen
- Department of Genetics and Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 USA
| | - Cindy L. Ehlers
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, California 92037 USA
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Ion Channel Genes and Epilepsy: Functional Alteration, Pathogenic Potential, and Mechanism of Epilepsy. Neurosci Bull 2017; 33:455-477. [PMID: 28488083 DOI: 10.1007/s12264-017-0134-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/20/2017] [Indexed: 01/29/2023] Open
Abstract
Ion channels are crucial in the generation and modulation of excitability in the nervous system and have been implicated in human epilepsy. Forty-one epilepsy-associated ion channel genes and their mutations are systematically reviewed. In this paper, we analyzed the genotypes, functional alterations (funotypes), and phenotypes of these mutations. Eleven genes featured loss-of-function mutations and six had gain-of-function mutations. Nine genes displayed diversified funotypes, among which a distinct funotype-phenotype correlation was found in SCN1A. These data suggest that the funotype is an essential consideration in evaluating the pathogenicity of mutations and a distinct funotype or funotype-phenotype correlation helps to define the pathogenic potential of a gene.
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Bernardo S, Marchionni E, Prudente S, De Liso P, Spalice A, Giancotti A, Manganaro L, Pizzuti A. Unusual association of SCN2A epileptic encephalopathy with severe cortical dysplasia detected by prenatal MRI. Eur J Paediatr Neurol 2017; 21:587-590. [PMID: 28254201 DOI: 10.1016/j.ejpn.2017.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/23/2017] [Accepted: 01/29/2017] [Indexed: 12/16/2022]
Abstract
We present an atypical association of SCN2A epileptic encephalopathy with severe cortical dysplasia. SCN2A mutations are associated with epileptic syndromes from benign to extremely severe in absence of such macroscopic brain findings. Prenatal MRI (Magnetic Resonance Imaging) in a 32 weeks fetus, with US (Ultrasonography) diagnosis of isolated ventriculomegaly showed CNS (Central Nervous System) dysplasia characterized by lack of differentiation between cortical and subcortical layers, pachygyria and corpus callosum dysgenesis. Postnatal MRI confirmed the prenatal findings. On day 6 the baby presented a focal status epilepticus, partially controlled by phenobarbital, phenytoin, and levetiracetam. After three weeks a moderate improvement in seizure control has been achieved with carbamazepine. Exome sequencing detected a de novo heterozygous mutation in the SCN2A gene, encoding the αII-subunit of a sodium channel. The patient findings expand the phenotype spectrum of SCN2A mutations to epileptic encephalopathies with macroscopic brain developmental features.
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Affiliation(s)
- Silvia Bernardo
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy; Department of Experimental Medicine, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy.
| | - Enrica Marchionni
- Department of Experimental Medicine, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy; IRCCS Casa Sollievo della Sofferenza, Mendel-laboratory, San Giovanni Rotondo, Italy.
| | - Sabrina Prudente
- IRCCS Casa Sollievo della Sofferenza, Mendel-laboratory, San Giovanni Rotondo, Italy.
| | - Paola De Liso
- Department of Pediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy.
| | - Alberto Spalice
- Department of Pediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy.
| | - Antonella Giancotti
- Department of Obstetrics, Gynecology and Urologic Sciences, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy.
| | - Lucia Manganaro
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy.
| | - Antonio Pizzuti
- Department of Experimental Medicine, Sapienza University of Rome, Policlinico Umberto I Hospital, Viale Regina Elena 324, Rome, Italy; IRCCS Casa Sollievo della Sofferenza, Mendel-laboratory, San Giovanni Rotondo, Italy.
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50
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CaMKII modulates sodium current in neurons from epileptic Scn2a mutant mice. Proc Natl Acad Sci U S A 2017; 114:1696-1701. [PMID: 28137877 DOI: 10.1073/pnas.1615774114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Monogenic epilepsies with wide-ranging clinical severity have been associated with mutations in voltage-gated sodium channel genes. In the Scn2aQ54 mouse model of epilepsy, a focal epilepsy phenotype is caused by transgenic expression of an engineered NaV1.2 mutation displaying enhanced persistent sodium current. Seizure frequency and other phenotypic features in Scn2aQ54 mice depend on genetic background. We investigated the neurophysiological and molecular correlates of strain-dependent epilepsy severity in this model. Scn2aQ54 mice on the C57BL/6J background (B6.Q54) exhibit a mild disorder, whereas animals intercrossed with SJL/J mice (F1.Q54) have a severe phenotype. Whole-cell recording revealed that hippocampal pyramidal neurons from B6.Q54 and F1.Q54 animals exhibit spontaneous action potentials, but F1.Q54 neurons exhibited higher firing frequency and greater evoked activity compared with B6.Q54 neurons. These findings correlated with larger persistent sodium current and depolarized inactivation in neurons from F1.Q54 animals. Because calcium/calmodulin protein kinase II (CaMKII) is known to modify persistent current and channel inactivation in the heart, we investigated CaMKII as a plausible modulator of neuronal sodium channels. CaMKII activity in hippocampal protein lysates exhibited a strain-dependence in Scn2aQ54 mice with higher activity in F1.Q54 animals. Heterologously expressed NaV1.2 channels exposed to activated CaMKII had enhanced persistent current and depolarized channel inactivation resembling the properties of F1.Q54 neuronal sodium channels. By contrast, inhibition of CaMKII attenuated persistent current, evoked a hyperpolarized channel inactivation, and suppressed neuronal excitability. We conclude that CaMKII-mediated modulation of neuronal sodium current impacts neuronal excitability in Scn2aQ54 mice and may represent a therapeutic target for the treatment of epilepsy.
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