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Chitolina R, Gallas-Lopes M, Reis CG, Benvenutti R, Stahlhofer-Buss T, Calcagnotto ME, Herrmann AP, Piato A. Chemically-induced epileptic seizures in zebrafish: A systematic review. Epilepsy Res 2023; 197:107236. [PMID: 37801749 DOI: 10.1016/j.eplepsyres.2023.107236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/14/2023] [Accepted: 09/28/2023] [Indexed: 10/08/2023]
Abstract
The use of zebrafish as a model organism is gaining evidence in the field of epilepsy as it may help to understand the mechanisms underlying epileptic seizures. As zebrafish assays became popular, the heterogeneity between protocols increased, making it hard to choose a standard protocol to conduct research while also impairing the comparison of results between studies. We conducted a systematic review to comprehensively profile the chemically-induced seizure models in zebrafish. Literature searches were performed in PubMed, Scopus, and Web of Science, followed by a two-step screening process based on inclusion/exclusion criteria. Qualitative data were extracted, and a sample of 100 studies was randomly selected for risk of bias assessment. Out of the 1058 studies identified after removing duplicates, 201 met the inclusion criteria. We found that the most common chemoconvulsants used in the reviewed studies were pentylenetetrazole (n = 180), kainic acid (n = 11), and pilocarpine (n = 10), which increase seizure severity in a dose-dependent manner. The main outcomes assessed were seizure scores and locomotion. Significant variability between the protocols was observed for administration route, duration of exposure, and dose/concentration. Of the studies subjected to risk of bias assessment, most were rated as low risk of bias for selective reporting (94%), baseline characteristics of the animals (67%), and blinded outcome assessment (54%). Randomization procedures and incomplete data were rated unclear in 81% and 68% of the studies, respectively. None of the studies reported the sample size calculation. Overall, these findings underscore the need for improved methodological and reporting practices to enhance the reproducibility and reliability of zebrafish models for studying epilepsy. Our study offers a comprehensive overview of the current state of chemically-induced seizure models in zebrafish, highlighting the common chemoconvulsants used and the variability in protocol parameters. This may be particularly valuable to researchers interested in understanding the underlying mechanisms of epileptic seizures and screening potential drug candidates in zebrafish models.
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Affiliation(s)
- Rafael Chitolina
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Psicofarmacologia e Comportamento (LAPCOM), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Matheus Gallas-Lopes
- Brazilian Reproducibility Initiative in Preclinical Systematic Review and meta-Analysis (BRISA) Collaboration, Brazil; Laboratório de Neurobiologia e Psicofarmacologia Experimental (PsychoLab), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos G Reis
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Psicofarmacologia e Comportamento (LAPCOM), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Radharani Benvenutti
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Thailana Stahlhofer-Buss
- Laboratório de Psicofarmacologia e Comportamento (LAPCOM), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Maria Elisa Calcagnotto
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Neurobiologia e Neuroquímica da Excitabilidade Neuronal e Plasticidade Sináptica (NNNESP Lab), Departamento de bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ana P Herrmann
- Brazilian Reproducibility Initiative in Preclinical Systematic Review and meta-Analysis (BRISA) Collaboration, Brazil; Laboratório de Neurobiologia e Psicofarmacologia Experimental (PsychoLab), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Angelo Piato
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Psicofarmacologia e Comportamento (LAPCOM), Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
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2
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Martins TG, Soliman R, Cordero-Maldonado ML, Donato C, Ameli C, Mombaerts L, Skupin A, Peri F, Crawford AD. Seizure-induced increase in microglial cell population in the developing zebrafish brain. Epilepsy Res 2023; 195:107203. [PMID: 37572541 DOI: 10.1016/j.eplepsyres.2023.107203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/21/2023] [Accepted: 07/31/2023] [Indexed: 08/14/2023]
Abstract
Epilepsy is a chronic brain disorder characterized by unprovoked and recurrent seizures, of which 60% are of unknown etiology. Recent studies implicate microglia in the pathophysiology of epilepsy. However, their role in this process, in particular following early-life seizures, remains poorly understood due in part to the lack of suitable experimental models allowing the in vivo imaging of microglial activity. Given the advantage of zebrafish larvae for minimally-invasive imaging approaches, we sought for the first time to describe the microglial responses after acute seizures in two different zebrafish larval models: a chemically-induced epileptic model by the systemic injection of kainate at 3 days post-fertilization, and the didys552 genetic epilepsy model, which carries a mutation in scn1lab that leads to spontaneous epileptiform discharges. Kainate-treated larvae exhibited transient brain damage as shown by increased numbers of apoptotic nuclei as early as one day post-injection, which was followed by an increase in the number of microglia in the brain. A similar microglial phenotype was also observed in didys552-/- mutants, suggesting that microglia numbers change in response to seizure-like activity in the brain. Interestingly, kainate-treated larvae also displayed a decreased seizure threshold towards subsequent pentylenetetrazole-induced seizures, as shown by higher locomotor and encephalographic activity in comparison with vehicle-injected larvae. These results are comparable to kainate-induced rodent seizure models and suggest the suitability of these zebrafish seizure models for future studies, in particular to elucidate the links between epileptogenesis and microglial dynamic changes after seizure induction in the developing brain, and to understand how these modulate seizure susceptibility.
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Affiliation(s)
- Teresa G Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg.
| | - Remon Soliman
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | - Cristina Donato
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Corrado Ameli
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Laurent Mombaerts
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Alexander Skupin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg; University of California, San Diego (UCSD), La Jolla, CA, United States
| | - Francesca Peri
- Developmental Biology Group, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg; Institute for Orphan Drug Discovery, Bremerhaven, Germany.
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3
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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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Knap B, Nieoczym D, Kundap U, Kusio-Targonska K, Kukula-Koch W, Turski WA, Gawel K. Zebrafish as a robust preclinical platform for screening plant-derived drugs with anticonvulsant properties-a review. Front Mol Neurosci 2023; 16:1221665. [PMID: 37701853 PMCID: PMC10493295 DOI: 10.3389/fnmol.2023.1221665] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/25/2023] [Indexed: 09/14/2023] Open
Abstract
Traditionally, selected plant sources have been explored for medicines to treat convulsions. This continues today, especially in countries with low-income rates and poor medical systems. However, in the low-income countries, plant extracts and isolated drugs are in high demand due to their good safety profiles. Preclinical studies on animal models of seizures/epilepsy have revealed the anticonvulsant and/or antiepileptogenic properties of, at least some, herb preparations or plant metabolites. Still, there is a significant number of plants known in traditional medicine that exert anticonvulsant activity but have not been evaluated on animal models. Zebrafish is recognized as a suitable in vivo model of epilepsy research and is increasingly used as a screening platform. In this review, the results of selected preclinical studies are summarized to provide credible information for the future development of effective screening methods for plant-derived antiseizure/antiepileptic therapeutics using zebrafish models. We compared zebrafish vs. rodent data to show the translational value of the former in epilepsy research. We also surveyed caveats in methodology. Finally, we proposed a pipeline for screening new anticonvulsant plant-derived drugs in zebrafish ("from tank to bedside and back again").
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Affiliation(s)
- Bartosz Knap
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Dorota Nieoczym
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Uday Kundap
- Canada East Spine Center, Saint John Regional Hospital, Horizon Health Center, Saint John, NB, Canada
| | - Kamila Kusio-Targonska
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Wirginia Kukula-Koch
- Department of Pharmacognosy with Medicinal Plants Garden, Medical University, Lublin, Poland
| | - Waldemar A. Turski
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Kinga Gawel
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
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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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Aquatic Freshwater Vertebrate Models of Epilepsy Pathology: Past Discoveries and Future Directions for Therapeutic Discovery. Int J Mol Sci 2022; 23:ijms23158608. [PMID: 35955745 PMCID: PMC9368815 DOI: 10.3390/ijms23158608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 12/04/2022] Open
Abstract
Epilepsy is an international public health concern that greatly affects patients’ health and lifestyle. About 30% of patients do not respond to available therapies, making new research models important for further drug discovery. Aquatic vertebrates present a promising avenue for improved seizure drug screening and discovery. Zebrafish (Danio rerio) and African clawed frogs (Xenopus laevis and tropicalis) are increasing in popularity for seizure research due to their cost-effective housing and rearing, similar genome to humans, ease of genetic manipulation, and simplicity of drug dosing. These organisms have demonstrated utility in a variety of seizure-induction models including chemical and genetic methods. Past studies with these methods have produced promising data and generated questions for further applications of these models to promote discovery of drug-resistant seizure pathology and lead to effective treatments for these patients.
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Li P, Zhang J, Liu X, Gan L, Xie Y, Zhang H, Si J. The Function and the Affecting Factors of the Zebrafish Gut Microbiota. Front Microbiol 2022; 13:903471. [PMID: 35722341 PMCID: PMC9201518 DOI: 10.3389/fmicb.2022.903471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Gut microbiota has become a topical issue in unraveling the research mechanisms underlying disease onset and progression. As an important and potential “organ,” gut microbiota plays an important role in regulating intestinal epithelial cell differentiation, proliferation, metabolic function and immune response, angiogenesis and host growth. More recently, zebrafish models have been used to study the interactions between gut microbiota and hosts. It has several advantages, such as short reproductive cycle, low rearing cost, transparent larvae, high genomic similarity to humans, and easy construction of germ-free (GF) and transgenic zebrafish. In our review, we reviewed a large amount of data focusing on the close relationship between gut microbiota and host health. Moreover, we outlined the functions of gut microbiota in regulating intestinal epithelial cell differentiation, intestinal epithelial cell proliferation, metabolic function, and immune response. More, we summarized major factors that can influence the composition, abundance, and diversity of gut microbiota, which will help us to understand the significance of gut microbiota in regulating host biological functions and provide options for maintaining the balance of host health.
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Affiliation(s)
- Pingping Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jinhua Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyi Liu
- College of Life Science, Lanzhou University, Lanzhou, China
| | - Lu Gan
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, China
| | - Yi Xie
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, China
| | - Hong Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, China
| | - Jing Si
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, China
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Zhang Y, Heylen L, Partoens M, Mills JD, Kaminski RM, Godard P, Gillard M, de Witte PAM, Siekierska A. Connectivity Mapping Using a Novel sv2a Loss-of-Function Zebrafish Epilepsy Model as a Powerful Strategy for Anti-epileptic Drug Discovery. Front Mol Neurosci 2022; 15:881933. [PMID: 35686059 PMCID: PMC9172968 DOI: 10.3389/fnmol.2022.881933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/08/2022] [Indexed: 12/03/2022] Open
Abstract
Synaptic vesicle glycoprotein 2A (SV2A) regulates action potential-dependent neurotransmitter release and is commonly known as the primary binding site of an approved anti-epileptic drug, levetiracetam. Although several rodent knockout models have demonstrated the importance of SV2A for functional neurotransmission, its precise physiological function and role in epilepsy pathophysiology remains to be elucidated. Here, we present a novel sv2a knockout model in zebrafish, a vertebrate with complementary advantages to rodents. We demonstrated that 6 days post fertilization homozygous sv2a–/– mutant zebrafish larvae, but not sv2a+/– and sv2a+/+ larvae, displayed locomotor hyperactivity and spontaneous epileptiform discharges, however, no major brain malformations could be observed. A partial rescue of this epileptiform brain activity could be observed after treatment with two commonly used anti-epileptic drugs, valproic acid and, surprisingly, levetiracetam. This observation indicated that additional targets, besides Sv2a, maybe are involved in the protective effects of levetiracetam against epileptic seizures. Furthermore, a transcriptome analysis provided insights into the neuropathological processes underlying the observed epileptic phenotype. While gene expression profiling revealed only one differentially expressed gene (DEG) between wildtype and sv2a+/– larvae, there were 4386 and 3535 DEGs between wildtype and sv2a–/–, and sv2a+/– and sv2a–/– larvae, respectively. Pathway and gene ontology (GO) enrichment analysis between wildtype and sv2a–/– larvae revealed several pathways and GO terms enriched amongst up- and down-regulated genes, including MAPK signaling, synaptic vesicle cycle, and extracellular matrix organization, all known to be involved in epileptogenesis and epilepsy. Importantly, we used the Connectivity map database to identify compounds with opposing gene signatures compared to the one observed in sv2a–/– larvae, to finally rescue the epileptic phenotype. Two out of three selected compounds rescued electrographic discharges in sv2a–/– larvae, while negative controls did not. Taken together, our results demonstrate that sv2a deficiency leads to increased seizure vulnerability and provide valuable insight into the functional importance of sv2a in the brain in general. Furthermore, we provided evidence that the concept of connectivity mapping represents an attractive and powerful approach in the discovery of novel compounds against epilepsy.
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Affiliation(s)
- Yifan Zhang
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Lise Heylen
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Michèle Partoens
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - James D. Mills
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- Chalfont Centre for Epilepsy, Chalfont St Peter, United Kingdom
| | - Rafal M. Kaminski
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Kraków, Poland
- UCB Pharma, Braine-l’Alleud, Belgium
| | | | | | - Peter A. M. de Witte
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
- *Correspondence: Peter A. M. de Witte,
| | - Aleksandra Siekierska
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
- Aleksandra Siekierska,
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Shaw PAG, Panda SK, Stanca A, Luyten W. Optimization of a locomotion-based zebrafish seizure model. J Neurosci Methods 2022; 375:109594. [PMID: 35421798 DOI: 10.1016/j.jneumeth.2022.109594] [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: 06/18/2021] [Revised: 03/22/2022] [Accepted: 04/02/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Locomotor assays in zebrafish have emerged as a screening test in early drug discovery for antiseizure compounds. However, parameters differ considerably between published studies, which may explain some discrepant results with (candidate) antiseizure medications. NEW METHOD We optimized a locomotor-based seizure assay in zebrafish with pentylenetetrazol (PTZ) as the pharmacological proconvulsant to generate a therapeutic window in which proconvulsant-treated zebrafish larvae could be discriminated from a non-treated control. To generate a reliable control, exposure time and concentration of valproate (VPA, anticonvulsant) was optimized. RESULTS Wells with one or three larvae show a similar PTZ dose-dependent increase in locomotion with less variability in motility for the latter. Zebrafish immersed in 10 mM PTZ showed a significant increase in movement with a sustained effect, without any indication of toxicity. Animals treated with 3 mM VPA showed the strongest reduction of PTZ-induced movement without toxicity. The decrease in PTZ-induced locomotion was greater after 18 h versus 2 h. COMPARISON WITH EXISTING METHOD(S) For the larval zebrafish PTZ-induced seizure model, varying experimental parameters have been reported in literature. Our results show that PTZ is often used at toxic concentrations, and we provide instead reliable conditions to quantify convulsant behaviour using an infrared-beam motility assay. CONCLUSIONS We recommend using three zebrafish larvae per well to quantify locomotion in 96-multiwell plates. Larvae should preferably be exposed to 10 mM PTZ for 1 h, consisting of 30 min acclimation and 30 min subsequent recording. As positive control for anticonvulsant activity, we recommend exposure to 3 mM VPA for 18 h before administration of PTZ.
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Affiliation(s)
| | - Sujogya Kumar Panda
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; Center of Environment Climate Change and Public Health, Utkal University, Vani Vihar, Bhubaneswar 751004, Odisha, India.
| | - Alexandru Stanca
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Walter Luyten
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
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