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Guo J, Min D, Farrell EK, Zhou Y, Faingold CL, Cotten JF, Feng HJ. Enhancing the action of serotonin by three different mechanisms prevents spontaneous seizure-induced mortality in Dravet mice. Epilepsia 2024; 65:1791-1800. [PMID: 38593237 PMCID: PMC11166528 DOI: 10.1111/epi.17966] [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: 08/17/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is an underestimated complication of epilepsy. Previous studies have demonstrated that enhancement of serotonergic neurotransmission suppresses seizure-induced sudden death in evoked seizure models. However, it is unclear whether elevated serotonin (5-HT) function will prevent spontaneous seizure-induced mortality (SSIM), which is characteristic of human SUDEP. We examined the effects of 5-HT-enhancing agents that act by three different pharmacological mechanisms on SSIM in Dravet mice, which exhibit a high incidence of SUDEP, modeling human Dravet syndrome. METHODS Dravet mice of both sexes were evaluated for spontaneous seizure characterization and changes in SSIM incidence induced by agents that enhance 5-HT-mediated neurotransmission. Fluoxetine (a selective 5-HT reuptake inhibitor), fenfluramine (a 5-HT releaser and agonist), SR 57227 (a specific 5-HT3 receptor agonist), or saline (vehicle) was intraperitoneally administered over an 8-day period in Dravet mice, and the effect of these treatments on SSIM was examined. RESULTS Spontaneous seizures in Dravet mice generally progressed from wild running to tonic seizures with or without SSIM. Fluoxetine at 30 mg/kg, but not at 20 or 5 mg/kg, significantly reduced SSIM compared with the vehicle control. Fenfluramine at 1-10 mg/kg, but not .2 mg/kg, fully protected Dravet mice from SSIM, with all mice surviving. Compared with the vehicle control, SR 57227 at 20 mg/kg, but not at 10 or 5 mg/kg, significantly lowered SSIM. The effect of these drugs on SSIM was independent of sex. SIGNIFICANCE Our data demonstrate that elevating serotonergic function by fluoxetine, fenfluramine, or SR 57227 significantly reduces or eliminates SSIM in Dravet mice in a sex-independent manner. These findings suggest that deficits in serotonergic neurotransmission likely play an important role in the pathogenesis of SSIM, and fluoxetine and fenfluramine, which are US Food and Drug Administration-approved medications, may potentially prevent SUDEP in at-risk patients.
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Affiliation(s)
- Jialing Guo
- National Health Commission Key Laboratory of Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
| | - Daniel Min
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Emory K. Farrell
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Yupeng Zhou
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Carl L. Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Joseph F. Cotten
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
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2
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Locubiche S, Ordóñez V, Abad E, Scotto di Mase M, Di Donato V, De Santis F. A Zebrafish-Based Platform for High-Throughput Epilepsy Modeling and Drug Screening in F0. Int J Mol Sci 2024; 25:2991. [PMID: 38474238 DOI: 10.3390/ijms25052991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/22/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
The zebrafish model has emerged as a reference tool for phenotypic drug screening. An increasing number of molecules have been brought from bench to bedside thanks to zebrafish-based assays over the last decade. The high homology between the zebrafish and the human genomes facilitates the generation of zebrafish lines carrying loss-of-function mutations in disease-relevant genes; nonetheless, even using this alternative model, the establishment of isogenic mutant lines requires a long generation time and an elevated number of animals. In this study, we developed a zebrafish-based high-throughput platform for the generation of F0 knock-out (KO) models and the screening of neuroactive compounds. We show that the simultaneous inactivation of a reporter gene (tyrosinase) and a second gene of interest allows the phenotypic selection of F0 somatic mutants (crispants) carrying the highest rates of mutations in both loci. As a proof of principle, we targeted genes associated with neurodevelopmental disorders and we efficiently generated de facto F0 mutants in seven genes involved in childhood epilepsy. We employed a high-throughput multiparametric behavioral analysis to characterize the response of these KO models to an epileptogenic stimulus, making it possible to employ kinematic parameters to identify seizure-like events. The combination of these co-injection, screening and phenotyping methods allowed us to generate crispants recapitulating epilepsy features and to test the efficacy of compounds already during the first days post fertilization. Since the strategy can be applied to a wide range of indications, this study paves the ground for high-throughput drug discovery and promotes the use of zebrafish in personalized medicine and neurotoxicity assessment.
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Affiliation(s)
- Sílvia Locubiche
- ZeClinics S.L., Carrer de Laureà Miró, 408-410, 08980 Sant Feliu de Llobregat, Spain
- Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain
| | - Víctor Ordóñez
- ZeClinics S.L., Carrer de Laureà Miró, 408-410, 08980 Sant Feliu de Llobregat, Spain
| | - Elena Abad
- ZeClinics S.L., Carrer de Laureà Miró, 408-410, 08980 Sant Feliu de Llobregat, Spain
| | | | - Vincenzo Di Donato
- ZeClinics S.L., Carrer de Laureà Miró, 408-410, 08980 Sant Feliu de Llobregat, Spain
| | - Flavia De Santis
- ZeClinics S.L., Carrer de Laureà Miró, 408-410, 08980 Sant Feliu de Llobregat, Spain
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3
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Fan HC, Yang MT, Lin LC, Chiang KL, Chen CM. Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy. Int J Mol Sci 2023; 25:31. [PMID: 38203200 PMCID: PMC10779156 DOI: 10.3390/ijms25010031] [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: 11/23/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.
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Affiliation(s)
- Hueng-Chuen Fan
- Department of Pediatrics, Tungs’ Taichung Metroharbor Hospital, Wuchi, Taichung 435, Taiwan;
- Department of Rehabilitation, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 356, Taiwan
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
| | - Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan;
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan
| | - Lung-Chang Lin
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Kuo-Liang Chiang
- Department of Pediatric Neurology, Kuang-Tien General Hospital, Taichung 433, Taiwan;
- Department of Nutrition, Hungkuang University, Taichung 433, Taiwan
| | - Chuan-Mu Chen
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- The iEGG and Animal Biotechnology Center, and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan
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4
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Lersch R, Jannadi R, Grosse L, Wagner M, Schneider MF, von Stülpnagel C, Heinen F, Potschka H, Borggraefe I. Targeted Molecular Strategies for Genetic Neurodevelopmental Disorders: Emerging Lessons from Dravet Syndrome. Neuroscientist 2023; 29:732-750. [PMID: 35414300 PMCID: PMC10623613 DOI: 10.1177/10738584221088244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the SCN1A gene encoding the voltage-gated sodium channel α subunit Nav1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for SCN1A-related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional SCN1A or by activating Nav1.1. These include antisense nucleotides directed against the nonproductive transcript of SCN1A with the poison exon 20N and against an inhibitory noncoding antisense RNA of SCN1A. Gene therapy approaches such as adeno-associated virus-based upregulation of SCN1A using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.
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Affiliation(s)
- Robert Lersch
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Rawan Jannadi
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Leonie Grosse
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Matias Wagner
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute for Neurogenomics, Helmholtz Centre Munich, German Research Center for Health and Environment (GmbH), Munich, Germany
| | - Marius Frederik Schneider
- Metabolic Biochemistry, Biomedical Center Munich, Medical Faculty, Ludwig Maximilians University, Munich, Germany
- International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried, Germany
| | - Celina von Stülpnagel
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Research Institute for Rehabilitation, Transition and Palliation, Paracelsus Medical Private University (PMU), Salzburg, Austria
| | - Florian Heinen
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Ingo Borggraefe
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
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5
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Auvin S, Galanopoulou AS, Moshé SL, Potschka H, Rocha L, Walker MC. Revisiting the concept of drug-resistant epilepsy: A TASK1 report of the ILAE/AES Joint Translational Task Force. Epilepsia 2023; 64:2891-2908. [PMID: 37676719 PMCID: PMC10836613 DOI: 10.1111/epi.17751] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 09/08/2023]
Abstract
Despite progress in the development of anti-seizure medications (ASMs), one third of people with epilepsy have drug-resistant epilepsy (DRE). The working definition of DRE, proposed by the International League Against Epilepsy (ILAE) in 2010, helped identify individuals who might benefit from presurgical evaluation early on. As the incidence of DRE remains high, the TASK1 workgroup on DRE of the ILAE/American Epilepsy Society (AES) Joint Translational Task Force discussed the heterogeneity and complexity of its presentation and mechanisms, the confounders in drawing mechanistic insights when testing treatment responses, and barriers in modeling DRE across the lifespan and translating across species. We propose that it is necessary to revisit the current definition of DRE, in order to transform the preclinical and clinical research of mechanisms and biomarkers, to identify novel, effective, precise, pharmacologic treatments, allowing for earlier recognition of drug resistance and individualized therapies.
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Affiliation(s)
- Stéphane Auvin
- Institut Universitaire de France, Paris, France
- Paediatric Neurology, Assistance Publique - Hôpitaux de Paris, EpiCARE ERN Member, Robert-Debré Hospital, Paris, France
- University Paris-Cité, Paris, France
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, and Montefiore/Einstein Epilepsy Center, Bronx, New York, USA
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, and Montefiore/Einstein Epilepsy Center, Bronx, New York, USA
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Luisa Rocha
- Pharmacobiology Department, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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6
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Ernst A, Piragyte I, Mp AM, Le ND, Grandgirard D, Leib SL, Oates A, Mercader N. Identification of side effects of COVID-19 drug candidates on embryogenesis using an integrated zebrafish screening platform. Sci Rep 2023; 13:17037. [PMID: 37813860 PMCID: PMC10562458 DOI: 10.1038/s41598-023-43911-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023] Open
Abstract
Drug repurposing is an important strategy in COVID-19 treatment, but many clinically approved compounds have not been extensively studied in the context of embryogenesis, thus limiting their administration during pregnancy. Here we used the zebrafish embryo model organism to test the effects of 162 marketed drugs on cardiovascular development. Among the compounds used in the clinic for COVD-19 treatment, we found that Remdesivir led to reduced body size and heart functionality at clinically relevant doses. Ritonavir and Baricitinib showed reduced heart functionality and Molnupiravir and Baricitinib showed effects on embryo activity. Sabizabulin was highly toxic at concentrations only 5 times higher than Cmax and led to a mean mortality of 20% at Cmax. Furthermore, we tested if zebrafish could be used as a model to study inflammatory response in response to spike protein treatment and found that Remdesivir, Ritonavir, Molnupiravir, Baricitinib as well as Sabizabulin counteracted the inflammatory response related gene expression upon SARS-CoV-2 spike protein treatment. Our results show that the zebrafish allows to study immune-modulating properties of COVID-19 compounds and highlights the need to rule out secondary defects of compound treatment on embryogenesis. All results are available on a user friendly web-interface https://share.streamlit.io/alernst/covasc_dataapp/main/CoVasc_DataApp.py that provides a comprehensive overview of all observed phenotypic effects and allows personalized search on specific compounds or group of compounds. Furthermore, the presented platform can be expanded for rapid detection of developmental side effects of new compounds for treatment of COVID-19 and further viral infectious diseases.
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Affiliation(s)
| | - Indre Piragyte
- Institute of Anatomy, University of Bern, Bern, Switzerland
- Department for Biomedical Research DBMR, University of Bern, Bern, Switzerland
| | - Ayisha Marwa Mp
- Institute of Anatomy, University of Bern, Bern, Switzerland
- Department for Biomedical Research DBMR, University of Bern, Bern, Switzerland
| | - Ngoc Dung Le
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Denis Grandgirard
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Stephen L Leib
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Andrew Oates
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nadia Mercader
- Institute of Anatomy, University of Bern, Bern, Switzerland.
- Department for Biomedical Research DBMR, University of Bern, Bern, Switzerland.
- Centro Nacional de Investigaciones Cardiovasculares, CNIC, Madrid, Spain.
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7
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Dini G, Di Cara G, Ferrara P, Striano P, Verrotti A. Reintroducing Fenfluramine as a Treatment for Seizures: Current Knowledge, Recommendations and Gaps in Understanding. Neuropsychiatr Dis Treat 2023; 19:2013-2025. [PMID: 37790801 PMCID: PMC10543412 DOI: 10.2147/ndt.s417676] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/19/2023] [Indexed: 10/05/2023] Open
Abstract
Despite the introduction of new anti-seizure medications in recent years, approximately one-third of the epileptic population continues to experience seizures. Recently, the anti-obesity medication fenfluramine (FFA) has been successfully repurposed, and it has received approval from various regulatory agencies for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome. The potential antiseizure effects of FFA were initially observed in patients with photosensitive epilepsy in the 1980s but it was not rigorously explored as a treatment option until 30 years later. This narrative review aims to provide an overview of the historical progression of FFA's use, starting from initial clinical observations to preclinical studies and, ultimately, successful clinical trials in the field of epilepsy.
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Affiliation(s)
- Gianluca Dini
- Department of Pediatrics, University of Perugia, Perugia, Italy
| | | | - Pietro Ferrara
- Department of Pediatrics, Campus Bio-Medico University, Rome, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto “G. Gaslini”, Genoa, Italy
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8
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Miguel Sanz C, Martinez Navarro M, Caballero Diaz D, Sanchez-Elexpuru G, Di Donato V. Toward the use of novel alternative methods in epilepsy modeling and drug discovery. Front Neurol 2023; 14:1213969. [PMID: 37719765 PMCID: PMC10501616 DOI: 10.3389/fneur.2023.1213969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Epilepsy is a chronic brain disease and, considering the amount of people affected of all ages worldwide, one of the most common neurological disorders. Over 20 novel antiseizure medications (ASMs) have been released since 1993, yet despite substantial advancements in our understanding of the molecular mechanisms behind epileptogenesis, over one-third of patients continue to be resistant to available therapies. This is partially explained by the fact that the majority of existing medicines only address seizure suppression rather than underlying processes. Understanding the origin of this neurological illness requires conducting human neurological and genetic studies. However, the limitation of sample sizes, ethical concerns, and the requirement for appropriate controls (many patients have already had anti-epileptic medication exposure) in human clinical trials underscore the requirement for supplemental models. So far, mammalian models of epilepsy have helped to shed light on the underlying causes of the condition, but the high costs related to breeding of the animals, low throughput, and regulatory restrictions on their research limit their usefulness in drug screening. Here, we present an overview of the state of art in epilepsy modeling describing gold standard animal models used up to date and review the possible alternatives for this research field. Our focus will be mainly on ex vivo, in vitro, and in vivo larval zebrafish models contributing to the 3R in epilepsy modeling and drug screening. We provide a description of pharmacological and genetic methods currently available but also on the possibilities offered by the continued development in gene editing methodologies, especially CRISPR/Cas9-based, for high-throughput disease modeling and anti-epileptic drugs testing.
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Turrini L, Roschi L, de Vito G, Pavone FS, Vanzi F. Imaging Approaches to Investigate Pathophysiological Mechanisms of Brain Disease in Zebrafish. Int J Mol Sci 2023; 24:9833. [PMID: 37372981 DOI: 10.3390/ijms24129833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Zebrafish has become an essential model organism in modern biomedical research. Owing to its distinctive features and high grade of genomic homology with humans, it is increasingly employed to model diverse neurological disorders, both through genetic and pharmacological intervention. The use of this vertebrate model has recently enhanced research efforts, both in the optical technology and in the bioengineering fields, aiming at developing novel tools for high spatiotemporal resolution imaging. Indeed, the ever-increasing use of imaging methods, often combined with fluorescent reporters or tags, enable a unique chance for translational neuroscience research at different levels, ranging from behavior (whole-organism) to functional aspects (whole-brain) and down to structural features (cellular and subcellular). In this work, we present a review of the imaging approaches employed to investigate pathophysiological mechanisms underlying functional, structural, and behavioral alterations of human neurological diseases modeled in zebrafish.
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Affiliation(s)
- Lapo Turrini
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Lorenzo Roschi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Giuseppe de Vito
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Viale Gaetano Pieraccini 6, 50139 Florence, Italy
- Interdepartmental Centre for the Study of Complex Dynamics, University of Florence, Via Giovanni Sansone 1, 50019 Sesto Fiorentino, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Via Giovanni Sansone 1, 50019 Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Francesco Vanzi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
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10
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D'Amora M, Galgani A, Marchese M, Tantussi F, Faraguna U, De Angelis F, Giorgi FS. Zebrafish as an Innovative Tool for Epilepsy Modeling: State of the Art and Potential Future Directions. Int J Mol Sci 2023; 24:ijms24097702. [PMID: 37175408 PMCID: PMC10177843 DOI: 10.3390/ijms24097702] [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: 04/06/2023] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
This article discusses the potential of Zebrafish (ZF) (Danio Rerio), as a model for epilepsy research. Epilepsy is a neurological disorder affecting both children and adults, and many aspects of this disease are still poorly understood. In vivo and in vitro models derived from rodents are the most widely used for studying both epilepsy pathophysiology and novel drug treatments. However, researchers have recently obtained several valuable insights into these two fields of investigation by studying ZF. Despite the relatively simple brain structure of these animals, researchers can collect large amounts of data in a much shorter period and at lower costs compared to classical rodent models. This is particularly useful when a large number of candidate antiseizure drugs need to be screened, and ethical issues are minimized. In ZF, seizures have been induced through a variety of chemoconvulsants, primarily pentylenetetrazol (PTZ), kainic acid (KA), and pilocarpine. Furthermore, ZF can be easily genetically modified to test specific aspects of monogenic forms of human epilepsy, as well as to discover potential convulsive phenotypes in monogenic mutants. The article reports on the state-of-the-art and potential new fields of application of ZF research, including its potential role in revealing epileptogenic mechanisms, rather than merely assessing iatrogenic acute seizure modulation.
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Affiliation(s)
- Marta D'Amora
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Biology, University of Pisa, 56125 Pisa, Italy
| | - Alessandro Galgani
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56126 Pisa, Italy
| | - Maria Marchese
- Molecular Medicine and Neurobiology-ZebraLab, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy
| | | | - Ugo Faraguna
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56126 Pisa, Italy
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy
| | | | - Filippo Sean Giorgi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56126 Pisa, Italy
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Gao C, Pielas M, Jiao F, Mei D, Wang X, Kotulska K, Jozwiak S. Epilepsy in Dravet Syndrome—Current and Future Therapeutic Opportunities. J Clin Med 2023; 12:jcm12072532. [PMID: 37048615 PMCID: PMC10094968 DOI: 10.3390/jcm12072532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023] Open
Abstract
Dravet Syndrome (DS) is a developmental epileptic encephalopathy characterized by drug-resistant seizures and other clinical features, including intellectual disability and behavioral, sleep, and gait problems. The pathogenesis is strongly connected to voltage-gated sodium channel dysfunction. The current consensus of seizure management in DS consists of a combination of conventional and recently approved drugs such as stiripentol, cannabidiol, and fenfluramine. Despite promising results in randomized clinical trials and extension studies, the prognosis of the developmental outcomes of patients with DS remains unfavorable. The article summarizes recent changes in the therapeutic approach to DS and discusses ongoing clinical research directions. Serotonergic agents under investigation show promising results and may replace less DS-specific medicines. The use of antisense nucleotides and gene therapy is focused not only on symptom relief but primarily addresses the underlying cause of the syndrome. Novel compounds, after expected safe and successful implementation in clinical practice, will open a new era for patients with DS. The main goal of causative treatment is to modify the natural course of the disease and provide the best neurodevelopmental outcome with minimum neurological deficit.
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12
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Burton EA, Burgess HA. A Critical Review of Zebrafish Neurological Disease Models-2. Application: Functional and Neuroanatomical Phenotyping Strategies and Chemical Screens. OXFORD OPEN NEUROSCIENCE 2022; 2:kvac019. [PMID: 37637775 PMCID: PMC10455049 DOI: 10.1093/oons/kvac019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/28/2022] [Indexed: 08/29/2023]
Abstract
Extensive phylogenetic conservation of molecular pathways and neuroanatomical structures, associated with efficient methods for genetic modification, have been exploited increasingly to generate zebrafish models of human disease. A range of powerful approaches can be deployed to analyze these models with the ultimate goal of elucidating pathogenic mechanisms and accelerating efforts to find effective treatments. Unbiased neurobehavioral assays can provide readouts that parallel clinical abnormalities found in patients, although some of the most useful assays quantify responses that are not routinely evaluated clinically, and differences between zebrafish and human brains preclude expression of the full range of neurobehavioral abnormalities seen in disease. Imaging approaches that use fluorescent reporters and standardized brain atlases coupled with quantitative measurements of brain structure offer an unbiased means to link experimental manipulations to changes in neural architecture. Together, quantitative structural and functional analyses allow dissection of the cellular and physiological basis underlying neurological phenotypes. These approaches can be used as outputs in chemical modifier screens, which provide a major opportunity to exploit zebrafish models to identify small molecule modulators of pathophysiology that may be informative for understanding disease mechanisms and possible therapeutic approaches.
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Affiliation(s)
- Edward A Burton
- Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Geriatric Research, Education, and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, PA 15240, USA
| | - Harold A Burgess
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
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13
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Hernández-Silva D, Alcaraz-Pérez F, Pérez-Sánchez H, Cayuela ML. Virtual screening and zebrafish models in tandem, for drug discovery and development. Expert Opin Drug Discov 2022:1-13. [DOI: 10.1080/17460441.2022.2147503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- David Hernández-Silva
- Telomerase, Cancer and Aging Group (TCAG), Hospital Clínico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria-Arrixaca (IMIB-Arrixaca), 30120 Murcia, Spain
- Structural Bioinformatics and High-Performance Computing Research Group (BIOHPC), Computer Engineering Department, Universidad Católica de Murcia (UCAM), Guadalupe, 30107 Murcia, Spain
| | - Francisca Alcaraz-Pérez
- Telomerase, Cancer and Aging Group (TCAG), Hospital Clínico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria-Arrixaca (IMIB-Arrixaca), 30120 Murcia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, 30100 Murcia, Spain
| | - Horacio Pérez-Sánchez
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, 30100 Murcia, Spain
| | - Maria Luisa Cayuela
- Telomerase, Cancer and Aging Group (TCAG), Hospital Clínico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria-Arrixaca (IMIB-Arrixaca), 30120 Murcia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, 30100 Murcia, Spain
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14
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Suvekbala V, Ramachandran H, Veluchamy A, Mascarenhas MAB, Ramprasath T, Nair MKC, Garikipati VNS, Gundamaraju R, Subbiah R. The Promising Epigenetic Regulators for Refractory Epilepsy: An Adventurous Road Ahead. Neuromolecular Med 2022:10.1007/s12017-022-08723-0. [DOI: 10.1007/s12017-022-08723-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 07/13/2022] [Indexed: 10/14/2022]
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15
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Fasano G, Compagnucci C, Dallapiccola B, Tartaglia M, Lauri A. Teleost Fish and Organoids: Alternative Windows Into the Development of Healthy and Diseased Brains. Front Mol Neurosci 2022; 15:855786. [PMID: 36034498 PMCID: PMC9403253 DOI: 10.3389/fnmol.2022.855786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
The variety in the display of animals’ cognition, emotions, and behaviors, typical of humans, has its roots within the anterior-most part of the brain: the forebrain, giving rise to the neocortex in mammals. Our understanding of cellular and molecular events instructing the development of this domain and its multiple adaptations within the vertebrate lineage has progressed in the last decade. Expanding and detailing the available knowledge on regionalization, progenitors’ behavior and functional sophistication of the forebrain derivatives is also key to generating informative models to improve our characterization of heterogeneous and mechanistically unexplored cortical malformations. Classical and emerging mammalian models are irreplaceable to accurately elucidate mechanisms of stem cells expansion and impairments of cortex development. Nevertheless, alternative systems, allowing a considerable reduction of the burden associated with animal experimentation, are gaining popularity to dissect basic strategies of neural stem cells biology and morphogenesis in health and disease and to speed up preclinical drug testing. Teleost vertebrates such as zebrafish, showing conserved core programs of forebrain development, together with patients-derived in vitro 2D and 3D models, recapitulating more accurately human neurogenesis, are now accepted within translational workflows spanning from genetic analysis to functional investigation. Here, we review the current knowledge of common and divergent mechanisms shaping the forebrain in vertebrates, and causing cortical malformations in humans. We next address the utility, benefits and limitations of whole-brain/organism-based fish models or neuronal ensembles in vitro for translational research to unravel key genes and pathological mechanisms involved in neurodevelopmental diseases.
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16
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Samanta D. Fenfluramine: A Review of Pharmacology, Clinical Efficacy, and Safety in Epilepsy. CHILDREN 2022; 9:children9081159. [PMID: 36010049 PMCID: PMC9406381 DOI: 10.3390/children9081159] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 11/29/2022]
Abstract
Despite the availability of more than 30 antiseizure medications (ASMs), the proportion of patients who remain refractory to ASMs remains static. Refractory seizures are almost universal in patients with epileptic encephalopathies. Since many of these patients are not candidates for curative surgery, there is always a need for newer ASMs with better efficacy and safety profile. Recently, the anti-obesity medication fenfluramine (FFA) has been successfully repurposed, and various regulatory agencies approved it for seizures associated with Dravet and Lennox–Gastaut syndromes. However, there is a limited in-depth critical review of FFA to facilitate its optimal use in a clinical context. This narrative review discusses and summarizes the antiseizure mechanism of action of FFA, clinical pharmacology, and clinical studies related to epilepsy, focusing on efficacy and adverse effects.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, 1 Children's Way, Little Rock, AR 72202, USA
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17
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Ochenkowska K, Herold A, Samarut É. Zebrafish Is a Powerful Tool for Precision Medicine Approaches to Neurological Disorders. Front Mol Neurosci 2022; 15:944693. [PMID: 35875659 PMCID: PMC9298522 DOI: 10.3389/fnmol.2022.944693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/17/2022] [Indexed: 12/17/2022] Open
Abstract
Personalized medicine is currently one of the most promising tools which give hope to patients with no suitable or no available treatment. Patient-specific approaches are particularly needed for common diseases with a broad phenotypic spectrum as well as for rare and yet-undiagnosed disorders. In both cases, there is a need to understand the underlying mechanisms and how to counteract them. Even though, during recent years, we have been observing the blossom of novel therapeutic techniques, there is still a gap to fill between bench and bedside in a patient-specific fashion. In particular, the complexity of genotype-to-phenotype correlations in the context of neurological disorders has dampened the development of successful disease-modifying therapeutics. Animal modeling of human diseases is instrumental in the development of therapies. Currently, zebrafish has emerged as a powerful and convenient model organism for modeling and investigating various neurological disorders. This model has been broadly described as a valuable tool for understanding developmental processes and disease mechanisms, behavioral studies, toxicity, and drug screening. The translatability of findings obtained from zebrafish studies and the broad prospect of human disease modeling paves the way for developing tailored therapeutic strategies. In this review, we will discuss the predictive power of zebrafish in the discovery of novel, precise therapeutic approaches in neurosciences. We will shed light on the advantages and abilities of this in vivo model to develop tailored medicinal strategies. We will also investigate the newest accomplishments and current challenges in the field and future perspectives.
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Affiliation(s)
- Katarzyna Ochenkowska
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.,Department of Neuroscience, Université de Montréal, Montreal, QC, Canada
| | - Aveeva Herold
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.,Department of Neuroscience, Université de Montréal, Montreal, QC, Canada
| | - Éric Samarut
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.,Department of Neuroscience, Université de Montréal, Montreal, QC, Canada.,Modelis Inc., Montreal, QC, Canada
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18
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Mesika A, Nadav G, Shochat C, Kalfon L, Jackson K, Khalaileh A, Karasik D, Falik-Zaccai TC. NGLY1 Deficiency Zebrafish Model Manifests Abnormalities of the Nervous and Musculoskeletal Systems. Front Cell Dev Biol 2022; 10:902969. [PMID: 35769264 PMCID: PMC9234281 DOI: 10.3389/fcell.2022.902969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Background: NGLY1 is an enigmatic enzyme with multiple functions across a wide range of species. In humans, pathogenic genetic variants in NGLY1 are linked to a variable phenotype of global neurological dysfunction, abnormal tear production, and liver disease presenting the rare autosomal recessive disorder N-glycanase deficiency. We have ascertained four NGLY1 deficiency patients who were found to carry a homozygous nonsense variant (c.1294G > T, p.Glu432*) in NGLY1. Methods: We created an ngly1 deficiency zebrafish model and studied the nervous and musculoskeletal (MSK) systems to further characterize the phenotypes and pathophysiology of the disease. Results: Nervous system morphology analysis has shown significant loss of axon fibers in the peripheral nervous system. In addition, we found muscle structure abnormality of the mutant fish. Locomotion behavior analysis has shown hypersensitivity of the larval ngly1(−/−) fish during stress conditions. Conclusion: This first reported NGLY1 deficiency zebrafish model might add to our understanding of NGLY1 role in the development of the nervous and MSK systems. Moreover, it might elucidate the natural history of the disease and be used as a platform for the development of novel therapies.
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Affiliation(s)
- Aviv Mesika
- Institute of Human Genetics, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Golan Nadav
- Institute of Human Genetics, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Chen Shochat
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Limor Kalfon
- Institute of Human Genetics, Galilee Medical Center, Nahariya, Israel
| | - Karen Jackson
- MIGAL, Galilee Research Institute, Kiryat Shmona, Israel
| | - Ayat Khalaileh
- Institute of Human Genetics, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - David Karasik
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Tzipora C. Falik-Zaccai
- Institute of Human Genetics, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
- *Correspondence: Tzipora C. Falik-Zaccai,
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19
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Moog M, Baraban SC. Clemizole and Trazodone are Effective Antiseizure Treatments in a Zebrafish Model of STXBP1 Disorder. Epilepsia Open 2022; 7:504-511. [PMID: 35451230 PMCID: PMC9436285 DOI: 10.1002/epi4.12604] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/19/2022] [Indexed: 11/07/2022] Open
Abstract
CRISPR-Cas9-generated zebrafish carrying a 12 base-pair deletion in stxbpb1b, a paralog sharing 79% amino acid sequence identity with human, exhibit spontaneous electrographic seizures during larval stages of development. Zebrafish stxbp1b mutants provide an efficient preclinical platform to test antiseizure therapeutics. The present study was designed to test antiseizure medications approved for clinical use and two recently identified repurposed drugs with antiseizure activity. Larval homozygous stxbp1b zebrafish (4 days post-fertilization) were agarose-embedded and monitored for electrographic seizure activity using a local field recording electrode placed in midbrain. Frequency of ictal-like events was evaluated at baseline and following 45 min of continuous drug exposure (1 mM, bath application). Analysis was performed on coded files by an experimenter blinded to drug treatment and genotype. Phenytoin, valproate, ethosuximide, levetiracetam, and diazepam had no effect on ictal-like event frequency in stxbp1b mutant zebrafish. Clemizole and trazodone decreased ictal-like event frequency in stxbp1b mutant zebrafish by 80% and 83%, respectively. These results suggest that repurposed drugs with serotonin receptor binding affinities could be effective antiseizure treatments. Clemizole and trazodone were previously identified in a larval zebrafish model for Dravet syndrome. Based primarily on these preclinical zebrafish studies, compassionate-use and double-blind clinical trials with both drugs have progressed. The present study extends this approach to a preclinical zebrafish model representing STXBP1-related disorders, and suggests that future clinical studies may be warranted.
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Affiliation(s)
- Maia Moog
- Department of Neurological Surgery & Weill Institute for NeuroscienceUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Scott C. Baraban
- Department of Neurological Surgery & Weill Institute for NeuroscienceUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Helen Wills Neuroscience InstituteUniversity of CaliforniaBerkeleyCaliforniaUSA
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20
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Turrini L, Sorelli M, de Vito G, Credi C, Tiso N, Vanzi F, Pavone FS. Multimodal Characterization of Seizures in Zebrafish Larvae. Biomedicines 2022; 10:951. [PMID: 35625689 PMCID: PMC9139036 DOI: 10.3390/biomedicines10050951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/07/2022] [Accepted: 04/15/2022] [Indexed: 11/17/2022] Open
Abstract
Epilepsy accounts for a significant proportion of the world's disease burden. Indeed, many research efforts are produced both to investigate the basic mechanism ruling its genesis and to find more effective therapies. In this framework, the use of zebrafish larvae, owing to their peculiar features, offers a great opportunity. Here, we employ transgenic zebrafish larvae expressing GCaMP6s in all neurons to characterize functional alterations occurring during seizures induced by pentylenetetrazole. Using a custom two-photon light-sheet microscope, we perform fast volumetric functional imaging of the entire larval brain, investigating how different brain regions contribute to seizure onset and propagation. Moreover, employing a custom behavioral tracking system, we outline the progressive alteration of larval swim kinematics, resulting from different grades of seizures. Collectively, our results show that the epileptic larval brain undergoes transitions between diverse neuronal activity regimes. Moreover, we observe that different brain regions are progressively recruited into the generation of seizures of diverse severity. We demonstrate that midbrain regions exhibit highest susceptibility to the convulsant effects and that, during periods preceding abrupt hypersynchronous paroxysmal activity, they show a consistent increase in functional connectivity. These aspects, coupled with the hub-like role that these regions exert, represent important cues in their identification as epileptogenic hubs.
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Affiliation(s)
- Lapo Turrini
- Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy;
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
| | - Michele Sorelli
- Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy;
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
| | - Giuseppe de Vito
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - Caterina Credi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
- National Institute of Optics, National Research Council, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35131 Padova, Italy;
| | - Francesco Vanzi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Francesco Saverio Pavone
- Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy;
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy; (G.d.V.); (C.C.); (F.V.)
- National Institute of Optics, National Research Council, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
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21
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Bialer M, Perucca E. Lorcaserin for Dravet Syndrome: A Potential Advance Over Fenfluramine? CNS Drugs 2022; 36:113-122. [PMID: 35094259 DOI: 10.1007/s40263-022-00896-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/09/2022] [Indexed: 12/12/2022]
Abstract
Lorcaserin, a selective serotonin 5-HT2C receptor agonist, was developed as an appetite suppressant with the rationale of minimizing the risk of cardiovascular toxicity associated with non-selective serotoninergic agents such as fenfluramine. Eight years after FDA approval, however, it was withdrawn from the market, when a large safety study suggested a potential cancer risk. Following in the fenfluramine footsteps and utilizing the repurposing approach coupled with the regulatory orphan drug designation, lorcaserin is currently in clinical development for the treatment of epilepsy. This potential novel indication builds on the evidence that 5-HT2C receptor stimulation can protect against seizures, and accounts at least in part for fenfluramine's antiseizure effects in Dravet syndrome models. In animal models, lorcaserin shows a narrower range of antiseizure activity than fenfluramine. In particular, lorcaserin is inactive in classical acute seizure tests such as maximal electroshock and subcutaneous pentylenetetrazole in mice and rats, and the 6-Hz stimulation model in mice. However, it is active in the GAERS absence seizure model, and in mutant zebrafish models of Dravet syndrome. Preliminary uncontrolled studies in patients with Dravet syndrome have yielded promising results, and a phase III, double-blind, placebo-controlled, parallel group trial is currently ongoing to assess its efficacy and safety in children and adults with Dravet syndrome.
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Affiliation(s)
- Meir Bialer
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel. .,David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Emilio Perucca
- Department of Medicine, Austin Health, University of Melbourne, Melbourne, VIC, Australia.,Department of Neuroscience, Monash University, Melbourne, VIC, Australia
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22
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Crouzier L, Richard EM, Sourbron J, Lagae L, Maurice T, Delprat B. Use of Zebrafish Models to Boost Research in Rare Genetic Diseases. Int J Mol Sci 2021; 22:13356. [PMID: 34948153 PMCID: PMC8706563 DOI: 10.3390/ijms222413356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 02/06/2023] Open
Abstract
Rare genetic diseases are a group of pathologies with often unmet clinical needs. Even if rare by a single genetic disease (from 1/2000 to 1/more than 1,000,000), the total number of patients concerned account for approximatively 400 million peoples worldwide. Finding treatments remains challenging due to the complexity of these diseases, the small number of patients and the challenge in conducting clinical trials. Therefore, innovative preclinical research strategies are required. The zebrafish has emerged as a powerful animal model for investigating rare diseases. Zebrafish combines conserved vertebrate characteristics with high rate of breeding, limited housing requirements and low costs. More than 84% of human genes responsible for diseases present an orthologue, suggesting that the majority of genetic diseases could be modelized in zebrafish. In this review, we emphasize the unique advantages of zebrafish models over other in vivo models, particularly underlining the high throughput phenotypic capacity for therapeutic screening. We briefly introduce how the generation of zebrafish transgenic lines by gene-modulating technologies can be used to model rare genetic diseases. Then, we describe how zebrafish could be phenotyped using state-of-the-art technologies. Two prototypic examples of rare diseases illustrate how zebrafish models could play a critical role in deciphering the underlying mechanisms of rare genetic diseases and their use to identify innovative therapeutic solutions.
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Affiliation(s)
- Lucie Crouzier
- MMDN, University of Montpellier, EPHE, INSERM, 34095 Montpellier, France; (L.C.); (E.M.R.); (T.M.)
| | - Elodie M. Richard
- MMDN, University of Montpellier, EPHE, INSERM, 34095 Montpellier, France; (L.C.); (E.M.R.); (T.M.)
| | - Jo Sourbron
- Department of Development and Regeneration, Section Pediatric Neurology, University Hospital KU Leuven, 3000 Leuven, Belgium; (J.S.); (L.L.)
| | - Lieven Lagae
- Department of Development and Regeneration, Section Pediatric Neurology, University Hospital KU Leuven, 3000 Leuven, Belgium; (J.S.); (L.L.)
| | - Tangui Maurice
- MMDN, University of Montpellier, EPHE, INSERM, 34095 Montpellier, France; (L.C.); (E.M.R.); (T.M.)
| | - Benjamin Delprat
- MMDN, University of Montpellier, EPHE, INSERM, 34095 Montpellier, France; (L.C.); (E.M.R.); (T.M.)
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23
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Heylen L, Pham DH, De Meulemeester AS, Samarut É, Skiba A, Copmans D, Kazwiny Y, Vanden Berghe P, de Witte PAM, Siekierska A. Pericardial Injection of Kainic Acid Induces a Chronic Epileptic State in Larval Zebrafish. Front Mol Neurosci 2021; 14:753936. [PMID: 34720874 PMCID: PMC8551382 DOI: 10.3389/fnmol.2021.753936] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is a common disorder of the brain characterized by spontaneous recurrent seizures, which develop gradually during a process called epileptogenesis. The mechanistic processes underlying the changes of brain tissue and networks toward increased seizure susceptibility are not fully understood. In rodents, injection of kainic acid (KA) ultimately leads to the development of spontaneous epileptic seizures, reflecting similar neuropathological characteristics as seen in patients with temporal lobe epilepsy (TLE). Although this model has significantly contributed to increased knowledge of epileptogenesis, it is technically demanding, costly to operate and hence not suitable for high-throughput screening of anti-epileptic drugs (AEDs). Zebrafish, a vertebrate with complementary advantages to rodents, is an established animal model for epilepsy research. Here, we generated a novel KA-induced epilepsy model in zebrafish larvae that we functionally and pharmacologically validated. KA was administered by pericardial injection at an early zebrafish larval stage. The epileptic phenotype induced was examined by quantification of seizure-like behavior using automated video recording, and of epileptiform brain activity measured via local field potential (LFP) recordings. We also assessed GFP-labeled GABAergic and RFP-labeled glutamatergic neurons in double transgenic KA-injected zebrafish larvae, and examined the GABA and glutamate levels in the larval heads by liquid chromatography with tandem mass spectrometry detection (LC-MS/MS). Finally, KA-injected larvae were exposed to five commonly used AEDs by immersion for pharmacological characterization of the model. Shortly after injection, KA induced a massive damage and inflammation in the zebrafish brain and seizure-like locomotor behavior. An abnormal reorganization of brain circuits was observed, a decrease in both GABAergic and glutamatergic neuronal population and their associated neurotransmitters. Importantly, these changes were accompanied by spontaneous and continuous epileptiform brain discharges starting after a short latency period, as seen in KA rodent models and reminiscent of human pathology. Three out of five AEDs tested rescued LFP abnormalities but did not affect the seizure-like behavior. Taken together, for the first time we describe a chemically-induced larval zebrafish epilepsy model offering unique insights into studying epileptogenic processes in vivo and suitable for high-throughput AED screening purposes and rapid genetic investigations.
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Affiliation(s)
- Lise Heylen
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Duc-Hung Pham
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | | | - Éric Samarut
- Department of Neurosciences, Research Center of the University of Montreal Hospital Center, University of Montreal, Montreal, QC, Canada.,Modelis Inc., Montreal, QC, Canada
| | - Adrianna Skiba
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Daniëlle Copmans
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Youcef Kazwiny
- Laboratory for Enteric Neuroscience, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
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24
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Sturgeon ML, Langton R, Sharma S, Cornell RA, Glykys J, Bassuk AG. The opioid antagonist naltrexone decreases seizure-like activity in genetic and chemically induced epilepsy models. Epilepsia Open 2021; 6:528-538. [PMID: 34664432 PMCID: PMC8408599 DOI: 10.1002/epi4.12512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/23/2021] [Accepted: 05/18/2021] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE A significant number of epileptic patients fail to respond to available anticonvulsive medications. To find new anticonvulsive medications, we evaluated FDA-approved drugs not known to be anticonvulsants. Using zebrafish larvae as an initial model system, we found that the opioid antagonist naltrexone exhibited an anticonvulsant effect. We validated this effect in three other epilepsy models and present naltrexone as a promising anticonvulsive candidate. METHODS Candidate anticonvulsant drugs, determined by our prior transcriptomics analysis of hippocampal tissue, were evaluated in a larval zebrafish model of human Dravet syndrome (scn1Lab mutants), in wild-type zebrafish larvae treated with the pro-convulsant drug pentylenetetrazole (PTZ), in wild-type C57bl/6J acute brain slices exposed to PTZ, and in wild-type mice treated with PTZ in vivo. Abnormal locomotion was determined behaviorally in zebrafish and mice and by field potential in neocortex layer IV/V and CA1 stratum pyramidale in the hippocampus. RESULTS The opioid antagonist naltrexone decreased abnormal locomotion in the larval zebrafish model of human Dravet syndrome (scn1Lab mutants) and wild-type larvae treated with the pro-convulsant drug PTZ. Naltrexone also decreased seizure-like events in acute brain slices of wild-type mice, and the duration and number of seizures in adult mice injected with PTZ. SIGNIFICANCE Our data reveal that naltrexone has anticonvulsive properties and is a candidate drug for seizure treatment.
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Affiliation(s)
| | - Rachel Langton
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
| | | | - Robert A. Cornell
- Department of Anatomy and Cell BiologyUniversity of IowaIowa CityIAUSA
| | - Joseph Glykys
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
- Department of NeurologyUniversity of IowaIowa CityIAUSA
| | - Alexander G. Bassuk
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
- Department of NeurologyUniversity of IowaIowa CityIAUSA
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Patton EE, Zon LI, Langenau DM. Zebrafish disease models in drug discovery: from preclinical modelling to clinical trials. Nat Rev Drug Discov 2021; 20:611-628. [PMID: 34117457 PMCID: PMC9210578 DOI: 10.1038/s41573-021-00210-8] [Citation(s) in RCA: 178] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2021] [Indexed: 02/03/2023]
Abstract
Numerous drug treatments that have recently entered the clinic or clinical trials have their genesis in zebrafish. Zebrafish are well established for their contribution to developmental biology and have now emerged as a powerful preclinical model for human disease, as their disease characteristics, aetiology and progression, and molecular mechanisms are clinically relevant and highly conserved. Zebrafish respond to small molecules and drug treatments at physiologically relevant dose ranges and, when combined with cell-specific or tissue-specific reporters and gene editing technologies, drug activity can be studied at single-cell resolution within the complexity of a whole animal, across tissues and over an extended timescale. These features enable high-throughput and high-content phenotypic drug screening, repurposing of available drugs for personalized and compassionate use, and even the development of new drug classes. Often, drugs and drug leads explored in zebrafish have an inter-organ mechanism of action and would otherwise not be identified through targeted screening approaches. Here, we discuss how zebrafish is an important model for drug discovery, the process of how these discoveries emerge and future opportunities for maximizing zebrafish potential in medical discoveries.
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Affiliation(s)
- E Elizabeth Patton
- MRC Human Genetics Unit and Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Cancer, Western General Hospital Campus, University of Edinburgh, Edinburgh, UK.
| | - Leonard I Zon
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Howard Hughes Medical Institute, Harvard Medical School; Harvard Stem Cell Institute, Stem Cell and Regenerative Biology Department, Harvard University, Boston, MA, USA.
| | - David M Langenau
- Department of Pathology, Massachusetts General Research Institute, Boston, MA, USA.
- Center of Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.
- Harvard Stem Cell Institute, Harvard University, Boston, MA, USA.
- Center of Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA.
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Gogou M, Cross JH. Fenfluramine as antiseizure medication for epilepsy. Dev Med Child Neurol 2021; 63:899-907. [PMID: 33565102 DOI: 10.1111/dmcn.14822] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/05/2021] [Indexed: 12/11/2022]
Abstract
Fenfluramine hydrochloride has classically been described as acting pharmacologically through a serotonergic mechanism. Therefore, it was initially used as an anorectic drug, given that impaired serotonin homeostasis may be associated with increased food intake. Although positive results were documented, cardiovascular concerns resulted in its temporary withdrawal. Nevertheless, a novel role in patients with epilepsy was later suggested by isolated clinical observations. The wide application of genetic testing allowed the classification (predominantly as Dravet syndrome) of patients in whom benefit was seen, while with the development of zebrafish models, its antiepileptic properties were confirmed at a molecular level. Data from randomized clinical trials have shown a beneficial effect of fenfluramine, as an adjunct therapy, on seizure control for children with Dravet syndrome, though there is still uncertainty about the impact on neurodevelopment in these patients. No signs of heart valve disease have been documented to date. Long-term and appropriately designed clinical studies will verify whether fenfluramine is a therapeutic agent of high importance, living up to the promise shown so far. What this paper adds Fenfluramine is a very promising repurposed therapy specifically for seizures in Dravet syndrome. The long-term effect of fenfluramine on neurodevelopmental prognosis requires further investigation.
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Affiliation(s)
- Maria Gogou
- Department of Neurology, Great Ormond Street Hospital for Children NHS Trust, London, UK
| | - J Helen Cross
- Department of Neurology, Great Ormond Street Hospital for Children NHS Trust, London, UK.,Developmental Neurosciences, University College London NIHR BRC Great Ormond Street Institute of Child Health, London, UK
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Abstract
Danio rerio (zebrafish) are a powerful experimental model for genetic and developmental studies. Adaptation of zebrafish to study seizures was initially established using the common convulsant agent pentylenetetrazole (PTZ). Larval PTZ-exposed zebrafish exhibit clear behavioral convulsions and abnormal electrographic activity, reminiscent of interictal and ictal epileptiform discharge. By using this model, our laboratory developed simple locomotion-based and electrophysiological assays to monitor and quantify seizures in larval zebrafish. Zebrafish also offer multiple advantages for rapid genetic manipulation and high-throughput phenotype-based drug screening. Combining these seizure assays with genetically modified zebrafish that represent Dravet syndrome, a rare genetic epilepsy, ultimately contributed to a phenotype-based screen of over 3500 drugs. Several drugs identified in these zebrafish screens are currently in clinical or compassionate-use trials. The emergence of this 'aquarium-to-bedside' approach suggests that broader efforts to adapt and improve upon this zebrafish-centric strategy can drive a variety of exciting new discoveries.
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Affiliation(s)
- Scott C Baraban
- Department of Neurological Surgery and Weill Institute for Neuroscience, University of California, San Francisco,CA 94143-0350, USA
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28
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Pernici CD, Mensah JA, Dahle EJ, Johnson KJ, Handy L, Buxton L, Smith MD, West PJ, Metcalf CS, Wilcox KS. Development of an antiseizure drug screening platform for Dravet syndrome at the NINDS contract site for the Epilepsy Therapy Screening Program. Epilepsia 2021; 62:1665-1676. [PMID: 34002394 PMCID: PMC8360068 DOI: 10.1111/epi.16925] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Dravet syndrome (DS) is a rare but catastrophic genetic epilepsy, with 80% of patients carrying a mutation in the SCN1A gene. Currently, no antiseizure drug (ASD) exists that adequately controls seizures. In the clinic, individuals with DS often present first with a febrile seizure and, subsequently, generalized tonic-clonic seizures that can continue throughout life. To facilitate the development of ASDs for DS, the contract site of the National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP) has evaluated a mouse model of DS using the conditional knock-in Scn1aA1783V/WT mouse. METHODS Survival rates and temperature thresholds for Scn1aA1783V/WT were determined. Prototype ASDs were administered via intraperitoneal injections at the time-to-peak effect, which was previously determined, prior to the induction of hyperthermia-induced seizures. ASDs were considered effective if they significantly increased the temperature at which Scn1aA1783V/WT mice had seizures. RESULTS Approximately 50% of Scn1aA1783V/WT survive to adulthood and all have hyperthermia-induced seizures. The results suggest that hyperthermia-induced seizures in this model of DS are highly refractory to a battery of ASDs. Exceptions were clobazam, tiagabine, levetiracetam, and the combination of clobazam and valproic acid with add-on stiripentol, which elevated seizure thresholds. SIGNIFICANCE Overall, the data demonstrate that the proposed model for DS is suitable for screening novel compounds for the ability to block hyperthermia-induced seizures and that heterozygous mice can be evaluated repeatedly over the course of several weeks, allowing for higher throughput screening.
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Affiliation(s)
- Chelsea D. Pernici
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Jeffrey A. Mensah
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - E. Jill Dahle
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Kristina J. Johnson
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Laura Handy
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Lauren Buxton
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Misty D. Smith
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Peter J. West
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Cameron S. Metcalf
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Karen S. Wilcox
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
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Shcheglovitov A, Peterson RT. Screening Platforms for Genetic Epilepsies-Zebrafish, iPSC-Derived Neurons, and Organoids. Neurotherapeutics 2021; 18:1478-1489. [PMID: 34595731 PMCID: PMC8608971 DOI: 10.1007/s13311-021-01115-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 02/04/2023] Open
Abstract
Recent advances in molecular and cellular engineering, such as human cell reprogramming, genome editing, and patient-specific organoids, have provided unprecedented opportunities for investigating human disorders in both animals and human-based models at an improved pace and precision. This progress will inevitably lead to the development of innovative drug-screening platforms and new patient-specific therapeutics. In this review, we discuss recent advances that have been made using zebrafish and human-induced pluripotent stem cell (iPSC)-derived neurons and organoids for modeling genetic epilepsies. We also provide our prospective on how these models can potentially be combined to build new screening platforms for antiseizure and antiepileptogenic drug discovery that harness the robustness and tractability of zebrafish models as well as the patient-specific genetics and biology of iPSC-derived neurons and organoids.
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30
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Phenotypic analysis of catastrophic childhood epilepsy genes. Commun Biol 2021; 4:680. [PMID: 34083748 PMCID: PMC8175701 DOI: 10.1038/s42003-021-02221-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/17/2021] [Indexed: 01/06/2023] Open
Abstract
Genetic engineering techniques have contributed to the now widespread use of zebrafish to investigate gene function, but zebrafish-based human disease studies, and particularly for neurological disorders, are limited. Here we used CRISPR-Cas9 to generate 40 single-gene mutant zebrafish lines representing catastrophic childhood epilepsies. We evaluated larval phenotypes using electrophysiological, behavioral, neuro-anatomical, survival and pharmacological assays. Local field potential recordings (LFP) were used to screen ∼3300 larvae. Phenotypes with unprovoked electrographic seizure activity (i.e., epilepsy) were identified in zebrafish lines for 8 genes; ARX, EEF1A, GABRB3, GRIN1, PNPO, SCN1A, STRADA and STXBP1. We also created an open-source database containing sequencing information, survival curves, behavioral profiles and representative electrophysiology data. We offer all zebrafish lines as a resource to the neuroscience community and envision them as a starting point for further functional analysis and/or identification of new therapies. Griffin et al used CRISPR-Cas9 to generate 40 single-gene mutant zebrafish lines representing childhood epilepsies for which they evaluated larval phenotypes using electrophysiological, behavioral, neuro-anatomical, survival and pharmacological assays. Their study provides a useful resource for the future functional analysis and/or identification of potential anti-epileptic therapies.
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31
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Galanopoulou AS, Löscher W, Lubbers L, O’Brien TJ, Staley K, Vezzani A, D’Ambrosio R, White HS, Sontheimer H, Wolf JA, Twyman R, Whittemore V, Wilcox KS, Klein B. Antiepileptogenesis and disease modification: Progress, challenges, and the path forward-Report of the Preclinical Working Group of the 2018 NINDS-sponsored antiepileptogenesis and disease modification workshop. Epilepsia Open 2021; 6:276-296. [PMID: 34033232 PMCID: PMC8166793 DOI: 10.1002/epi4.12490] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/04/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is one of the most common chronic brain diseases and is often associated with cognitive, behavioral, or other medical conditions. The need for therapies that would prevent, ameliorate, or cure epilepsy and the attendant comorbidities is a priority for both epilepsy research and public health. In 2018, the National Institute of Neurological Disease and Stroke (NINDS) convened a workshop titled "Accelerating the Development of Therapies for Antiepileptogenesis and Disease Modification" that brought together preclinical and clinical investigators and industry and regulatory bodies' representatives to discuss and propose a roadmap to accelerate the development of antiepileptogenic (AEG) and disease-modifying (DM) new therapies. This report provides a summary of the discussions and proposals of the Preclinical Science working group. Highlights of the progress of collaborative preclinical research projects on AEG/DM of ongoing research initiatives aiming to improve infrastructure and translation to clinical trials are presented. Opportunities and challenges of preclinical epilepsy research, vis-à-vis clinical research, were extensively discussed, as they pertain to modeling of specific epilepsy types across etiologies and ages, the utilization of preclinical models in AG/DM studies, and the strategies and study designs, as well as on matters pertaining to transparency, data sharing, and reporting research findings. A set of suggestions on research initiatives, infrastructure, workshops, advocacy, and opportunities for expanding the borders of epilepsy research were discussed and proposed as useful initiatives that could help create a roadmap to accelerate and optimize preclinical translational AEG/DM epilepsy research.
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Affiliation(s)
- Aristea S. Galanopoulou
- Saul R. Korey Department of NeurologyDominick P. Purpura Department of NeuroscienceIsabelle Rapin Division of Child NeurologyAlbert Einstein College of MedicineBronxNYUSA
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary Medicine HannoverHannoverGermany
| | | | - Terence J. O’Brien
- Department of NeuroscienceCentral Clinical SchoolAlfred HealthMonash UniversityMelbourneVic.Australia
| | - Kevin Staley
- Department of NeurologyMassachusetts General HospitalBostonMAUSA
| | - Annamaria Vezzani
- Department of NeuroscienceIRCCS‐Mario Negri Institute for Pharmacological ResearchMilanoItaly
| | | | - H. Steve White
- Department of PharmacySchool of PharmacyUniversity of WashingtonSeattleWAUSA
| | | | - John A. Wolf
- Center for Brain Injury and RepairDepartment of NeurosurgeryUniversity of PennsylvaniaPhiladelphiaPAUSA
- Corporal Michael J. Crescenz Veterans Affairs Medical CenterPhiladelphiaPAUSA
| | | | - Vicky Whittemore
- National Institute of Neurological Disorders and StrokeNational Institutes of HealthBethesdaMDUSA
| | - Karen S. Wilcox
- Department of Pharmacology & ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Brian Klein
- National Institute of Neurological Disorders and StrokeNational Institutes of HealthBethesdaMDUSA
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32
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Barthelson K, Baer L, Dong Y, Hand M, Pujic Z, Newman M, Goodhill GJ, Richards RI, Pederson SM, Lardelli M. Zebrafish Chromosome 14 Gene Differential Expression in the fmr1 h u2787 Model of Fragile X Syndrome. Front Genet 2021; 12:625466. [PMID: 34135935 PMCID: PMC8203322 DOI: 10.3389/fgene.2021.625466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
Zebrafish represent a valuable model for investigating the molecular and cellular basis of Fragile X syndrome (FXS). Reduced expression of the zebrafish FMR1 orthologous gene, fmr1, causes developmental and behavioural phenotypes related to FXS. Zebrafish homozygous for the hu2787 non-sense mutation allele of fmr1 are widely used to model FXS, although FXS-relevant phenotypes seen from morpholino antisense oligonucleotide (morpholino) suppression of fmr1 transcript translation were not observed when hu2787 was first described. The subsequent discovery of transcriptional adaptation (a form of genetic compensation), whereby mutations causing non-sense-mediated decay of transcripts can drive compensatory upregulation of homologous transcripts independent of protein feedback loops, suggested an explanation for the differences reported. We examined the whole-embryo transcriptome effects of homozygosity for fmr1 h u2787 at 2 days post fertilisation. We observed statistically significant changes in expression of a number of gene transcripts, but none from genes showing sequence homology to fmr1. Enrichment testing of differentially expressed genes implied effects on lysosome function and glycosphingolipid biosynthesis. The majority of the differentially expressed genes are located, like fmr1, on Chromosome 14. Quantitative PCR tests did not support that this was artefactual due to changes in relative chromosome abundance. Enrichment testing of the "leading edge" differentially expressed genes from Chromosome 14 revealed that their co-location on this chromosome may be associated with roles in brain development and function. The differential expression of functionally related genes due to mutation of fmr1, and located on the same chromosome as fmr1, is consistent with R.A. Fisher's assertion that the selective advantage of co-segregation of particular combinations of alleles of genes will favour, during evolution, chromosomal rearrangements that place them in linkage disequilibrium on the same chromosome. However, we cannot exclude that the apparent differential expression of genes on Chromosome 14 genes was, (if only in part), caused by differences between the expression of alleles of genes unrelated to the effects of the fmr1 h u2787 mutation and made manifest due to the limited, but non-zero, allelic diversity between the genotypes compared.
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Affiliation(s)
- Karissa Barthelson
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Lachlan Baer
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Yang Dong
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Melanie Hand
- Bioinformatics Hub, University of Adelaide, Adelaide, SA, Australia
| | - Zac Pujic
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
| | - Morgan Newman
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Geoffrey J. Goodhill
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
- School of Mathematics and Physics, University of Queensland, Brisbane, QLD, Australia
| | - Robert I. Richards
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | | | - Michael Lardelli
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
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Oprişoreanu AM, Smith HL, Krix S, Chaytow H, Carragher NO, Gillingwater TH, Becker CG, Becker T. Automated in vivo drug screen in zebrafish identifies synapse-stabilising drugs with relevance to spinal muscular atrophy. Dis Model Mech 2021; 14:259422. [PMID: 33973627 PMCID: PMC8106959 DOI: 10.1242/dmm.047761] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
Synapses are particularly vulnerable in many neurodegenerative diseases and often the first to degenerate, for example in the motor neuron disease spinal muscular atrophy (SMA). Compounds that can counteract synaptic destabilisation are rare. Here, we describe an automated screening paradigm in zebrafish for small-molecule compounds that stabilize the neuromuscular synapse in vivo. We make use of a mutant for the axonal C-type lectin chondrolectin (chodl), one of the main genes dysregulated in SMA. In chodl-/- mutants, neuromuscular synapses that are formed at the first synaptic site by growing axons are not fully mature, causing axons to stall, thereby impeding further axon growth beyond that synaptic site. This makes axon length a convenient read-out for synapse stability. We screened 982 small-molecule compounds in chodl chodl-/- mutants and found four that strongly rescued motor axon length. Aberrant presynaptic neuromuscular synapse morphology was also corrected. The most-effective compound, the adenosine uptake inhibitor drug dipyridamole, also rescued axon growth defects in the UBA1-dependent zebrafish model of SMA. Hence, we describe an automated screening pipeline that can detect compounds with relevance to SMA. This versatile platform can be used for drug and genetic screens, with wider relevance to synapse formation and stabilisation.
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Affiliation(s)
- Ana-Maria Oprişoreanu
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Hannah L Smith
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Sophia Krix
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Helena Chaytow
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Neil O Carragher
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, EH4 2XR Edinburgh, UK
| | - Thomas H Gillingwater
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Catherina G Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Thomas Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
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Odi R, Invernizzi RW, Gallily T, Bialer M, Perucca E. Fenfluramine repurposing from weight loss to epilepsy: What we do and do not know. Pharmacol Ther 2021; 226:107866. [PMID: 33895186 DOI: 10.1016/j.pharmthera.2021.107866] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/26/2021] [Accepted: 04/12/2021] [Indexed: 12/21/2022]
Abstract
In 2020, racemic-fenfluramine was approved in the U.S. and Europe for the treatment of seizures associated with Dravet syndrome, through a restricted/controlled access program aimed at minimizing safety risks. Fenfluramine had been used extensively in the past as an appetite suppressant, but it was withdrawn from the market in 1997 when it was found to cause cardiac valvulopathy. Available evidence indicates that appetite suppression and cardiac valvulopathy are mediated by different serotonergic mechanisms. In particular, appetite suppression can be ascribed mainly to the enantiomers d-fenfluramine and d-norfenfluramine, the primary metabolite of d-fenfluramine, whereas cardiac valvulopathy can be ascribed mainly to d-norfenfluramine. Because of early observations of markedly improved seizure control in some forms of epilepsy, fenfluramine remained available in Belgium through a Royal Decree after 1997 for use in a clinical trial in patients with Dravet syndrome at average dosages lower than those generally prescribed for appetite suppression. More recently, double-blind placebo-controlled trials established its efficacy in the treatment of convulsive seizures associated with Dravet syndrome and of drop seizures associated with Lennox-Gastaut syndrome, at doses up to 0.7 mg/kg/day (maximum 26 mg/day). Although no cardiovascular toxicity has been associated with the use of fenfluramine in epilepsy, the number of patients exposed to date has been limited and only few patients had duration of exposure longer than 3 years. This article analyzes available evidence on the mechanisms involved in fenfluramine-induced appetite suppression, antiseizure effects and cardiovascular toxicity. Despite evidence that stimulation of 5-HT2B receptors (the main mechanism leading to cardiac valvulopathy) is not required for antiseizure activity, there are many critical gaps in understanding fenfluramine's properties which are relevant to its use in epilepsy. Particular emphasis is placed on the remarkable lack of publicly accessible information about the comparative activity of the individual enantiomers of fenfluramine and norfenfluramine in experimental models of seizures and epilepsy, and on receptors systems considered to be involved in antiseizure effects. Preliminary data suggest that l-fenfluramine retains prominent antiseizure effects in a genetic zebrafish model of Dravet syndrome. If these findings are confirmed and extended to other seizure/epilepsy models, there would be an incentive for a chiral switch from racemic-fenfluramine to l-fenfluramine, which could minimize the risk of cardiovascular toxicity and reduce the incidence of adverse effects such as loss of appetite and weight loss.
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Affiliation(s)
- Reem Odi
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Tamar Gallily
- Yissum Technology Transfer Company of the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Meir Bialer
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel; David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Emilio Perucca
- Division of Clinical and Experimental Pharmacology, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
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35
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Ferreira MKA, da Silva AW, Dos Santos Moura AL, Sales KVB, Marinho EM, do Nascimento Martins Cardoso J, Marinho MM, Bandeira PN, Magalhães FEA, Marinho ES, de Menezes JESA, Dos Santos HS. Chalcones reverse the anxiety and convulsive behavior of adult zebrafish. Epilepsy Behav 2021; 117:107881. [PMID: 33711684 DOI: 10.1016/j.yebeh.2021.107881] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/22/2021] [Accepted: 02/20/2021] [Indexed: 01/07/2023]
Abstract
In the treatment of anxiety and seizures, drugs of the benzodiazepine (BZD) class are used, which act on the Central Nervous System (CNS) through the neurotransmitter gamma-aminobutyric acid (GABA). Flavonoids modulate GABAA receptors. The aim of this study was to evaluate the anxiolytic and anticonvulsant effects of synthetic chalcones and their mechanisms of action via the GABAergic system, using adult zebrafish (ZFa). The animals were treated with chalcones (4.0 or 20 or 40 mg/kg; 20 µL; i.p) and submitted to the open field and 96 h toxicity test. Chalcones that cause locomotor alteration were evaluated in the light and dark anxiolytic test. The same doses of chalcones were evaluated in the anticonvulsant test. The lowest effective dose was chosen to assess the possible involvement in the GABAA receptor by blocking the flumazenil (fmz) antagonist. No chalcone was toxic and altered ZFa's locomotion. All chalcones had anxiolytic and anticonvulsant effects, mainly chalcones 1, where all doses showed effects in both tests. These effects were blocked by Fmz (antagonist GABAA), where it shows evidence of the performance of these activities of the GABA system. Therefore, this study demonstrated in relation to structure-activity, that the position of the substituents is important in the intensity of activities and that the absence of toxicity and the action of these compounds in the CNS, shows the pharmacological potential of these molecules, and, therefore, the insights are designed for the development of new drugs.
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Affiliation(s)
| | | | - Atilano Lucas Dos Santos Moura
- State University of Ceará, Graduate Program in Natural Sciences, Natural Products Chemistry Laboratory, Fortaleza, Ceará, Brazil
| | - Ketelly Vanessa Barros Sales
- State University of Ceará, Graduate Program in Natural Sciences, Natural Products Chemistry Laboratory, Fortaleza, Ceará, Brazil
| | - Emanuelle Machado Marinho
- Federal University of Ceará, Department of Analytical Chemistry and Physical Chemistry, Group of Theoretical Chemistry, Fortaleza, Ceará, Brazil
| | | | - Márcia Machado Marinho
- State University of Ceará, Iguatu Faculty of Education, Science and Letters, Ceará, Brazil
| | - Paulo Nogueira Bandeira
- Center for Exact Sciences and Technology, Vale do Acaraú State University, Sobral, Ceará, Brazil
| | - Francisco Ernani Alves Magalhães
- State University of Ceará, Department of Chemistry, Laboratory of Natural Products Bioprospecting and Biotechnology, Tauá, Ceará, Brazil
| | - Emmanuel Silva Marinho
- State University of Ceará, Department of Chemistry, Group of Theoretical Chemistry And Electrochemistry, Limoeiro do Norte, Ceará, Brazil
| | | | - Hélcio Silva Dos Santos
- State University of Ceará, Graduate Program in Natural Sciences, Natural Products Chemistry Laboratory, Fortaleza, Ceará, Brazil; Postgraduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil; Center for Exact Sciences and Technology, Vale do Acaraú State University, Sobral, Ceará, Brazil.
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36
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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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37
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Schoonjans AS, Ceulemans B. A critical evaluation of fenfluramine hydrochloride for the treatment of Dravet syndrome. Expert Rev Neurother 2021; 22:351-364. [PMID: 33455486 DOI: 10.1080/14737175.2021.1877540] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Dravet Syndrome (DS) is a severe developmental and epileptic encephalopathy. Fenfluramine recently demonstrated to be a highly efficacious and safe treatment option for DS patients. Fenfluramine has been recently approved by the FDA and EMA and is marketed as Fintepla®.Areas covered: DS and the need for additional anticonvulsive treatment options is discussed. The results of three placebo-controlled phase III studies (1 with and 2 without stiripentol) and 2 open label (extension) studies are reviewed. All studies demonstrate a consistent and impressive seizure reduction, confirming the results of two smaller investigator-initiated trials. The mechanism of action of fenfluramine is discussed. Finally, the place of fenfluramine in the future treatment of DS is outlined.Expert opinion: Fenfluramine has a potent anticonvulsive effect in DS. Although not yet fully elucidated, the anticonvulsive mechanism of fenfluramine seems to be mainly serotonergic. Fenfluramine is generally well tolerated. A dose reduction is necessary in combination with stiripentol. Considering new competitors, efficacy seems lower for cannabidiol and is comparable with stiripentol. Preclinical studies indicate a disease specific action and possible disease modification in DS. The latter would support the use of fenfluramine above its anticonvulsive effect and needs to be further elaborated.
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Affiliation(s)
- An-Sofie Schoonjans
- Department of Pediatrics and Pediatric Neurology, Antwerp University Hospital, Edegem, Belgium.,Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Berten Ceulemans
- Department of Pediatrics and Pediatric Neurology, Antwerp University Hospital, Edegem, Belgium.,Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
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38
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Banerji R, Huynh C, Figueroa F, Dinday MT, Baraban SC, Patel M. Enhancing glucose metabolism via gluconeogenesis is therapeutic in a zebrafish model of Dravet syndrome. Brain Commun 2021; 3:fcab004. [PMID: 33842883 PMCID: PMC8023476 DOI: 10.1093/braincomms/fcab004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/18/2023] Open
Abstract
Energy-producing pathways are novel therapeutic targets for the treatment of neurodevelopmental disorders. Here, we focussed on correcting metabolic defects in a catastrophic paediatric epilepsy, Dravet syndrome which is caused by mutations in sodium channel NaV1.1 gene, SCN1A. We utilized a translatable zebrafish model of Dravet syndrome (scn1lab) which exhibits key characteristics of patients with Dravet syndrome and shows metabolic deficits accompanied by down-regulation of gluconeogenesis genes, pck1 and pck2. Using a metabolism-based small library screen, we identified compounds that increased gluconeogenesis via up-regulation of pck1 gene expression in scn1lab larvae. Treatment with PK11195, a pck1 activator and a translocator protein ligand, normalized dys-regulated glucose levels, metabolic deficits, translocator protein expression and significantly decreased electrographic seizures in mutant larvae. Inhibition of pck1 in wild-type larvae mimicked metabolic and behaviour defects observed in scn1lab mutants. Together, this suggests that correcting dys-regulated metabolic pathways can be therapeutic in neurodevelopmental disorders such as Dravet syndrome arising from ion channel dysfunction.
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Affiliation(s)
- Rajeswari Banerji
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, CA 80045, USA
| | - Christopher Huynh
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, CA 80045, USA
| | - Francisco Figueroa
- Department of Neurological Surgery, Epilepsy Research Laboratory, University of California, San Francisco, CA 94143, USA
| | - Matthew T Dinday
- Department of Neurological Surgery, Epilepsy Research Laboratory, University of California, San Francisco, CA 94143, USA
| | - Scott C Baraban
- Department of Neurological Surgery, Epilepsy Research Laboratory, University of California, San Francisco, CA 94143, USA
| | - Manisha Patel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, CA 80045, USA
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Yaksi E, Jamali A, Diaz Verdugo C, Jurisch-Yaksi N. Past, present and future of zebrafish in epilepsy research. FEBS J 2021; 288:7243-7255. [PMID: 33394550 DOI: 10.1111/febs.15694] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/17/2020] [Accepted: 12/31/2020] [Indexed: 12/17/2022]
Abstract
Animal models contribute greatly to our understanding of brain development and function as well as its dysfunction in neurological diseases. Epilepsy research is a very good example of how animal models can provide us with a mechanistic understanding of the genes, molecules, and pathophysiological processes involved in disease. Over the course of the last two decades, zebrafish came in as a new player in epilepsy research, with an expanding number of laboratories using this animal to understand epilepsy and to discover new strategies for preventing seizures. Yet, zebrafish as a model offers a lot more for epilepsy research. In this viewpoint, we aim to highlight some key contributions of zebrafish to epilepsy research, and we want to emphasize the great untapped potential of this animal model for expanding these contributions. We hope that our suggestions will trigger further discussions between clinicians and researchers with a common goal to understand and cure epilepsy.
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Affiliation(s)
- Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ahmed Jamali
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway
| | - Carmen Diaz Verdugo
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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40
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Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
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Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
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41
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Shen D, Chen J, Liu D, Shen M, Wang X, Wu Y, Ke S, Macdonald RL, Zhang Q. The GABRG2 F343L allele causes spontaneous seizures in a novel transgenic zebrafish model that can be treated with suberanilohydroxamic acid (SAHA). ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1560. [PMID: 33437759 PMCID: PMC7791267 DOI: 10.21037/atm-20-3745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Mutations in the γ-aminobutyric acid type A (GABAA) receptor γ2 subunit gene, GABRG2, have been associated frequently with epilepsy syndromes with varying severities. Recently, a de novo GABRG2 mutation, c.T1027C, p.F343L, was identified in a patient with an early onset epileptic encephalopathy (EOEE). In vitro, we demonstrated that GABAA receptors containing the mutant γ2(F343L) subunit have impaired trafficking to the cell surface. Here, we aim to validate an in vivo zebrafish model of EOEE associated with the GABRG2 mutation T1027C. Methods We generated a novel transgenic zebrafish (AB strain) that overexpressed mutant human γ2(F343L) subunits and provided an initial characterization of the transgenic Tg(hGABRG2F343L) zebrafish. Results Real-time quantitative PCR and in situ hybridization identified a significant up-regulation of c-fos in the mutant transgenic zebrafish, which has a well-established role in epileptogenesis. In the larval stage 5 days postfertilization (dpf), freely swimming Tg(hGABRG2F343L) zebrafish displayed spontaneous seizure-like behaviors consisting of whole-body shaking and hyperactivity during automated locomotion video tracking, and seizures can be induced by light stimulation. Using RNA sequencing, we investigated transcriptomic changes due to the presence of mutant γ2L(F343L) subunits and have found 524 genes that are differentially expressed, including up-regulation of 33 genes associated with protein processing. More specifically, protein network analysis indicated histone deacetylases (HDACs) as potential therapeutic targets, and suberanilohydroxamic acid (SAHA), a broad HDACs inhibitor, alleviated seizure-like phenotypes in mutant zebrafish larvae. Conclusions Overall, our Tg(hGABRG2F343L) overexpression zebrafish model provides the first example of a human epilepsy-associated GABRG2 mutation resulting in spontaneous seizures in zebrafish. Moreover, HDAC inhibition may be worth investigating as a therapeutic strategy for genetic epilepsies caused by missense mutations in GABRG2 and possibly in other central nervous system genes that impair surface trafficking.
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Affiliation(s)
- Dingding Shen
- Department of Neurology & Collaborative Innovation Center for Brain Science, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Juan Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Dong Liu
- School of Life Science, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Mi Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xin Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Youjia Wu
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Shuan Ke
- Xinglin College, Nantong University, Nantong, China
| | - Robert L Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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42
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Balagura G, Cacciatore M, Grasso EA, Striano P, Verrotti A. Fenfluramine for the Treatment of Dravet Syndrome and Lennox-Gastaut Syndrome. CNS Drugs 2020; 34:1001-1007. [PMID: 32875491 DOI: 10.1007/s40263-020-00755-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The last 50 years has seen the introduction of a great number of antiepileptic drugs, relieving the burden of seizures for many patients. However, some conditions remain a challenge for epileptologists, especially Dravet syndrome and Lennox-Gastaut syndrome, which are severe epileptic and developmental encephalopathies characterized by multiple seizure types and electroencephalographic abnormalities that are often unresponsive to combinations of antiepileptic drugs. The re-purposing of an old drug such as fenfluramine could provide an indispensable tool for clinicians, especially because only a few drugs have been tested in relatively homogeneous populations, like Dravet syndrome. It could also provide insights into precision medicine approaches to the treatment of epileptic syndromes. We searched for relevant papers within MEDLINE, EMBASE, and the Clinical Trial Database, considering publications through July 2020. Pre-clinical studies show a mechanism of action for fenfluramine that goes beyond its pro-serotoninergic activity and that is at the intersection of several pathways involved in excitation/inhibition balance. From the ongoing clinical trial data, it is evident that fenfluramine is proving to be a promising antiepileptic drug with very favorable pharmacokinetics and with a good overall safety profile when used at a lower dosage (0.2-0.7 mg/kg/day), despite its previously link to major cardiac adverse events that prompted its withdrawal from the market in 1997. Here, we review the experimental and clinical evidence of the efficacy of fenfluramine, including the latest results from ongoing clinical trials, and critically discuss the future potential of fenfluramine in terms of safety and precision medicine. Available data from the literature suggest a very good efficacy for both epileptic syndromes with a reduction in seizure burden and a longer seizure-free interval. We note the higher prevalence of evidence in patients with Dravet syndrome. Fenfluramine has been used in association with both first- and second-line medications, while its use in monotherapy still needs to be assessed.
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Affiliation(s)
- Ganna Balagura
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy.,Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G. Gaslini' Institute, Genoa, Italy
| | - Marta Cacciatore
- Department of Pediatrics, University of L'Aquila, Via Vetoio 1, 67100, Coppito, L'Aquila, Italy.,Department of Pediatrics, University of Chieti, Chieti, Italy
| | - Eleonora A Grasso
- Department of Pediatrics, University of L'Aquila, Via Vetoio 1, 67100, Coppito, L'Aquila, Italy.,Department of Pediatrics, University of Chieti, Chieti, Italy
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy.,Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G. Gaslini' Institute, Genoa, Italy
| | - Alberto Verrotti
- Department of Pediatrics, University of L'Aquila, Via Vetoio 1, 67100, Coppito, L'Aquila, Italy.
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Jones A, Barker-Haliski M, Ilie AS, Herd MB, Baxendale S, Holdsworth CJ, Ashton JP, Placzek M, Jayasekera BAP, Cowie CJA, Lambert JJ, Trevelyan AJ, Steve White H, Marson AG, Cunliffe VT, Sills GJ, Morgan A. A multiorganism pipeline for antiseizure drug discovery: Identification of chlorothymol as a novel γ-aminobutyric acidergic anticonvulsant. Epilepsia 2020; 61:2106-2118. [PMID: 32797628 PMCID: PMC10756143 DOI: 10.1111/epi.16644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Current medicines are ineffective in approximately one-third of people with epilepsy. Therefore, new antiseizure drugs are urgently needed to address this problem of pharmacoresistance. However, traditional rodent seizure and epilepsy models are poorly suited to high-throughput compound screening. Furthermore, testing in a single species increases the chance that therapeutic compounds act on molecular targets that may not be conserved in humans. To address these issues, we developed a pipeline approach using four different organisms. METHODS We sequentially employed compound library screening in the zebrafish, Danio rerio, chemical genetics in the worm, Caenorhabditis elegans, electrophysiological analysis in mouse and human brain slices, and preclinical validation in mouse seizure models to identify novel antiseizure drugs and their molecular mechanism of action. RESULTS Initially, a library of 1690 compounds was screened in an acute pentylenetetrazol seizure model using D rerio. From this screen, the compound chlorothymol was identified as an effective anticonvulsant not only in fish, but also in worms. A subsequent genetic screen in C elegans revealed the molecular target of chlorothymol to be LGC-37, a worm γ-aminobutyric acid type A (GABAA ) receptor subunit. This GABAergic effect was confirmed using in vitro brain slice preparations from both mice and humans, as chlorothymol was shown to enhance tonic and phasic inhibition and this action was reversed by the GABAA receptor antagonist, bicuculline. Finally, chlorothymol exhibited in vivo anticonvulsant efficacy in several mouse seizure assays, including the 6-Hz 44-mA model of pharmacoresistant seizures. SIGNIFICANCE These findings establish a multiorganism approach that can identify compounds with evolutionarily conserved molecular targets and translational potential, and so may be useful in drug discovery for epilepsy and possibly other conditions.
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Affiliation(s)
- Alistair Jones
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | | | - Andrei S. Ilie
- Institute of Neuroscience, University of Newcastle, Newcastle, UK
| | - Murray B. Herd
- Neuroscience, Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Sarah Baxendale
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | | | - John-Paul Ashton
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Marysia Placzek
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Bodiabaduge A. P. Jayasekera
- Institute of Neuroscience, University of Newcastle, Newcastle, UK
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle, UK
| | - Christopher J. A. Cowie
- Institute of Neuroscience, University of Newcastle, Newcastle, UK
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle, UK
| | - Jeremy J. Lambert
- Neuroscience, Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | | | - H. Steve White
- Department of Pharmacy, University of Washington, Seattle
| | - Anthony G. Marson
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | | | - Graeme J. Sills
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- School of Life Sciences, University of Glasgow, Glasgow, UK
| | - Alan Morgan
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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Takai A, Yamaguchi M, Yoshida H, Chiyonobu T. Investigating Developmental and Epileptic Encephalopathy Using Drosophila melanogaster. Int J Mol Sci 2020; 21:ijms21176442. [PMID: 32899411 PMCID: PMC7503973 DOI: 10.3390/ijms21176442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are the spectrum of severe epilepsies characterized by early-onset, refractory seizures occurring in the context of developmental regression or plateauing. Early infantile epileptic encephalopathy (EIEE) is one of the earliest forms of DEE, manifesting as frequent epileptic spasms and characteristic electroencephalogram findings in early infancy. In recent years, next-generation sequencing approaches have identified a number of monogenic determinants underlying DEE. In the case of EIEE, 85 genes have been registered in Online Mendelian Inheritance in Man as causative genes. Model organisms are indispensable tools for understanding the in vivo roles of the newly identified causative genes. In this review, we first present an overview of epilepsy and its genetic etiology, especially focusing on EIEE and then briefly summarize epilepsy research using animal and patient-derived induced pluripotent stem cell (iPSC) models. The Drosophila model, which is characterized by easy gene manipulation, a short generation time, low cost and fewer ethical restrictions when designing experiments, is optimal for understanding the genetics of DEE. We therefore highlight studies with Drosophila models for EIEE and discuss the future development of their practical use.
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Affiliation(s)
- Akari Takai
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
- Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Kyoto 619-0237, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
| | - Tomohiro Chiyonobu
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
- Correspondence:
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Thornton C, Dickson KE, Carty DR, Ashpole NM, Willett KL. Cannabis constituents reduce seizure behavior in chemically-induced and scn1a-mutant zebrafish. Epilepsy Behav 2020; 110:107152. [PMID: 32585475 PMCID: PMC8276876 DOI: 10.1016/j.yebeh.2020.107152] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 12/22/2022]
Abstract
Current antiepileptic drugs (AEDs) are undesirable for many reasons including the inability to reduce seizures in certain types of epilepsy, such as Dravet syndrome (DS) where in one-third of patients does not respond to current AEDs, and severe adverse effects that are frequently experienced by patients. Epidiolex, a cannabidiol (CBD)-based drug, was recently approved for treatment of DS. While Epidiolex shows great promise in reducing seizures in patients with DS, it is used in conjunction with other AEDs and can cause liver toxicity. To investigate whether other cannabis-derived compounds could also reduce seizures, the antiepileptic effects of CBD, Δ9-tetrahydrocannabinol (THC), cannabidivarin (CBDV), cannabinol (CBN), and linalool (LN) were compared in both a chemically-induced (pentylenetetrazole, PTZ) and a DS (scn1Lab-/-) seizure models. Zebrafish (Danio rerio) that were either wild-type (Tupfel longfin) or scn1Lab-/- (DS) were exposed to CBD, THC, CBDV, CBN, or LN for 24 h from 5 to 6 days postfertilization. Following exposure, total distance traveled was measured in a ViewPoint Zebrabox to determine if these compounds reduced seizure-like activity. Cannabidiol (0.6 and 1 μM) and THC (1 and 4 μM) significantly reduced PTZ-induced total distance moved. At the highest THC concentration, the significant reduction in PTZ-induced behavior was likely the result of sedation as opposed to antiseizure activity. In the DS model, CBD (0.6 μM), THC (1 μM), CBN (0.6 and 1 μM), and LN (4 μM) significantly reduced total distance traveled. Cannabinol was the most effective at reducing total distance relative to controls. In addition to CBD, other cannabis-derived compounds showed promise in reducing seizure-like activity in zebrafish. Specifically, four of the five compounds were effective in the DS model, whereas in the PTZ model, only CBD and THC were, suggesting a divergence in the mode of action among the cannabis constituents.
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Affiliation(s)
- Cammi Thornton
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, United States of America
| | - Kennedy E Dickson
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, United States of America
| | - Dennis R Carty
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, United States of America
| | - Nicole M Ashpole
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, United States of America
| | - Kristine L Willett
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, United States of America.
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46
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Gawel K, Langlois M, Martins T, van der Ent W, Tiraboschi E, Jacmin M, Crawford AD, Esguerra CV. Seizing the moment: Zebrafish epilepsy models. Neurosci Biobehav Rev 2020; 116:1-20. [PMID: 32544542 DOI: 10.1016/j.neubiorev.2020.06.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/20/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
Zebrafish are now widely accepted as a valuable animal model for a number of different central nervous system (CNS) diseases. They are suitable both for elucidating the origin of these disorders and the sequence of events culminating in their onset, and for use as a high-throughput in vivo drug screening platform. The availability of powerful and effective techniques for genome manipulation allows the rapid modelling of different genetic epilepsies and of conditions with seizures as a core symptom. With this review, we seek to summarize the current knowledge about existing epilepsy/seizures models in zebrafish (both pharmacological and genetic) and compare them with equivalent rodent and human studies. New findings obtained from the zebrafish models are highlighted. We believe that this comprehensive review will highlight the value of zebrafish as a model for investigating different aspects of epilepsy and will help researchers to use these models to their full extent.
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Affiliation(s)
- Kinga Gawel
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego St. 8b, 20-090, Lublin, Poland
| | | | - Teresa Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Wietske van der Ent
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway
| | - Ettore Tiraboschi
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Neurophysics Group, Center for Mind/Brain Sciences, University of Trento, Piazza Manifattura 1, Building 14, 38068, Rovereto, TN, Italy
| | - Maxime Jacmin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg; Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway.
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47
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Dozières-Puyravel B, Auvin S. Fenfluramine hydrochloride for the treatment of Dravet syndrome. Expert Opin Orphan Drugs 2020. [DOI: 10.1080/21678707.2020.1758930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | - Stéphane Auvin
- APHP, Service de Neurologie Pédiatrique, Hôpital Robert Debré, Paris, France
- INSERM NeuroDiderot, Université De Paris, Paris, France
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48
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Griffin A, Anvar M, Hamling K, Baraban SC. Phenotype-Based Screening of Synthetic Cannabinoids in a Dravet Syndrome Zebrafish Model. Front Pharmacol 2020; 11:464. [PMID: 32390835 PMCID: PMC7193054 DOI: 10.3389/fphar.2020.00464] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/25/2020] [Indexed: 12/24/2022] Open
Abstract
Dravet syndrome is a catastrophic epilepsy of childhood, characterized by cognitive impairment, severe seizures, and increased risk for sudden unexplained death in epilepsy (SUDEP). Although refractory to conventional antiepileptic drugs, emerging preclinical and clinical evidence suggests that modulation of the endocannabinoid system could be therapeutic in these patients. Preclinical research on this topic is limited as cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are designated by United States Drug Enforcement Agency (DEA) as illegal substances. In this study, we used a validated zebrafish model of Dravet syndrome, scn1lab homozygous mutants, to screen for anti-seizure activity in a commercially available library containing 370 synthetic cannabinoid (SC) compounds. SCs are intended for experimental use and not restricted by DEA designations. Primary phenotype-based screening was performed using a locomotion-based assay in 96-well plates, and a secondary local field potential recording assay was then used to confirm suppression of electrographic epileptiform events. Identified SCs with anti-seizure activity, in both assays, included five SCs structurally classified as indole-based cannabinoids JWH 018 N-(5-chloropentyl) analog, JWH 018 N-(2-methylbutyl) isomer, 5-fluoro PB-22 5-hydroxyisoquinoline isomer, 5-fluoro ADBICA, and AB-FUBINACA 3-fluorobenzyl isomer. Our approach demonstrates that two-stage phenotype-based screening in a zebrafish model of Dravet syndrome successfully identifies SCs with anti-seizure activity.
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Affiliation(s)
- Aliesha Griffin
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Mana Anvar
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Kyla Hamling
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Scott C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
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49
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Tiraboschi E, Martina S, van der Ent W, Grzyb K, Gawel K, Cordero-Maldonado ML, Poovathingal SK, Heintz S, Satheesh SV, Brattespe J, Xu J, Suster M, Skupin A, Esguerra CV. New insights into the early mechanisms of epileptogenesis in a zebrafish model of Dravet syndrome. Epilepsia 2020; 61:549-560. [PMID: 32096222 DOI: 10.1111/epi.16456] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 02/03/2020] [Accepted: 02/03/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To pinpoint the earliest cellular defects underlying seizure onset (epileptogenic period) during perinatal brain development in a new zebrafish model of Dravet syndrome (DS) and to investigate potential disease-modifying activity of the 5HT2 receptor agonist fenfluramine. METHODS We used CRISPR/Cas9 mutagenesis to introduce a missense mutation, designed to perturb ion transport function in all channel isoforms, into scn1lab, the zebrafish orthologue of SCN1A (encoding voltage-gated sodium channel alpha subunit 1). We performed behavioral analysis and electroencephalographic recordings to measure convulsions and epileptiform discharges, followed by single-cell RNA-Seq, morphometric analysis of transgenic reporter-labeled γ-aminobutyric acidergic (GABAergic) neurons, and pharmacological profiling of mutant larvae. RESULTS Homozygous mutant (scn1labmut/mut ) larvae displayed spontaneous seizures with interictal, preictal, and ictal discharges (mean = 7.5 per 20-minute recording; P < .0001; one-way analysis of variance). Drop-Seq analysis revealed a 2:1 shift in the ratio of glutamatergic to GABAergic neurons in scn1labmut/mut larval brains versus wild type (WT), with dynamic changes in neuronal, glial, and progenitor cell populations. To explore disease pathophysiology further, we quantified dendritic arborization in GABAergic neurons and observed a 40% reduction in arbor number compared to WT (P < .001; n = 15 mutant, n = 16 WT). We postulate that the significant reduction in inhibitory arbors causes an inhibitory to excitatory neurotransmitter imbalance that contributes to seizures and enhanced electrical brain activity in scn1labmut/mut larvae (high-frequency range), with subsequent GABAergic neuronal loss and astrogliosis. Chronic fenfluramine administration completely restored dendritic arbor numbers to normal in scn1labmut/mut larvae, whereas similar treatment with the benzodiazepine diazepam attenuated seizures, but was ineffective in restoring neuronal cytoarchitecture. BrdU labeling revealed cell overproliferation in scn1labmut/mut larval brains that were rescued by fenfluramine but not diazepam. SIGNIFICANCE Our findings provide novel insights into early mechanisms of DS pathogenesis, describe dynamic cell population changes in the scn1labmut/mut brain, and present first-time evidence for potential disease modification by fenfluramine.
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Affiliation(s)
- Ettore Tiraboschi
- Chemical Neuroscience Group, Center for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | - Silvia Martina
- Integrative Cell Signaling Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Wietske van der Ent
- Chemical Neuroscience Group, Center for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | - Kamil Grzyb
- Integrative Cell Signaling Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Kinga Gawel
- Chemical Neuroscience Group, Center for Molecular Medicine Norway, University of Oslo, Oslo, Norway.,Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Maria Lorena Cordero-Maldonado
- Integrative Cell Signaling Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Suresh Kumar Poovathingal
- Integrative Cell Signaling Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Sarah Heintz
- Chemical Neuroscience Group, Center for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | | | - Jarle Brattespe
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Ju Xu
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Alexander Skupin
- Integrative Cell Signaling Group, Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Camila V Esguerra
- Chemical Neuroscience Group, Center for Molecular Medicine Norway, University of Oslo, Oslo, Norway.,Department of Pharmacy, University of Oslo, Oslo, Norway
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50
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Ibhazehiebo K, Rho JM, Kurrasch DM. Metabolism-based drug discovery in zebrafish: An emerging strategy to uncover new anti-seizure therapies. Neuropharmacology 2020; 167:107988. [PMID: 32070912 DOI: 10.1016/j.neuropharm.2020.107988] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 12/20/2022]
Abstract
As one of the most common neurological disorders, epilepsy can occur throughout the lifespan and from a multiplicity of causes, including genetic mutations, inflammation, neurotrauma, or brain malformations. Although pharmacological agents are the mainstay of treatment for seizure control, an unyielding 30-40% of patients remain refractory to these medications and continue to experience spontaneous recurrent seizures with attendant life-long cognitive, behavioural, and mental health issues, as well as an increased risk for sudden unexpected death. Despite over eight decades of antiseizure drug (ASD) discovery and the approval of dozens of new medications, the percentage of this refractory population remains virtually unchanged, suggesting that drugs with new and unexpected mechanisms of action are needed. In this brief review, we discuss the need for new animal models of epilepsy, with a particular focus on the advantages and disadvantages of zebrafish. We also outline the evidence that epilepsy is characterized by derangements in mitochondrial function and introduce the rationale and promise of bioenergetics as a functional readout assay to uncover novel ASDs. We also consider limitations of a zebrafish metabolism-based drug screening approach. Our goal is to discuss the opportunities and challenges of further development of mitochondrial screening strategies for the development of novel ASDs. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Kingsley Ibhazehiebo
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Canada
| | - Jong M Rho
- Alberta Children's Hospital Research Institute, University of Calgary, Canada; Department of Pediatrics, Cumming School of Medicine, University of Calgary, Canada; Department of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital San Diego, California, USA
| | - Deborah M Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Canada.
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