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Tong X, Wang Q, Yang J, Zhou J, Chen X, Gan J, Cai Q, Yu T, Luo R. Optimizing ketogenic diet therapy for childhood epilepsy: Identifying key factors for seizure control and psychomotor enhancement. Epilepsia 2024. [PMID: 39190400 DOI: 10.1111/epi.18098] [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: 02/26/2024] [Revised: 08/02/2024] [Accepted: 08/02/2024] [Indexed: 08/28/2024]
Abstract
OBJECTIVE To identify key factors influencing the therapeutic efficacy of the ketogenic diet (KD) for children with drug-resistant epilepsy and elucidate their interconnected relationships to optimize clinical practice. METHODS Participants were selected from children receiving KD treatment at West Second University Hospital of Sichuan University from September 2015 to October 2023. Clinical factors pre-KD and post-KD (at the third month) were analyzed systematically using an analytical framework. Descriptive analyses, univariate analyses, and multivariate regression analyses were performed for the entire cohort and subgroups of genetic and non-genetic (i.e., structural and unknown) etiologies. Thereby, the most significant predictors were identified for each relevant dependent variable. Path analysis diagrams were used for visual representation. RESULTS Of 156 patients, genetic etiology was prevalent (38.5%). In the genetic subgroup, channelopathies predicted lower baseline seizure frequency and increased chance of seizure freedom with KD. Frequent seizures and complex history of anti-seizure medications (ASMs) predicted severe baseline psychomotor abnormalities. Younger age at KD initiation benefited psychomotor improvement. In the non-genetic subgroup, lower baseline seizure frequency increased the likelihood of seizure freedom post-KD. Concurrent use of multiple ASMs helped achieve ≥50% seizure reduction. Boys were more likely to experience psychomotor improvement. A significant correlation was found between ≥50% seizure reduction and psychomotor improvement in both subgroups. Delayed KD initiation (longer epilepsy duration at KD start) was related to a greater number of ASMs used, infrequent seizures, and older age at epilepsy onset. In addition, patients with channelopathies had delayed initiation of KD. SIGNIFICANCE Children with genetic epilepsy display more pronounced characteristics of epileptic encephalopathy. Early KD intervention is crucial for channelopathies, notably SCN1A variants. For other drug-resistant epilepsy cases, KD alongside diverse ASMs may improve seizure control and developmental outcomes. However, the patient population benefiting most from early KD tends to start the treatment later, urging a re-evaluation of KD decision-making paradigms.
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Affiliation(s)
- Xin Tong
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Qian Wang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Jie Yang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Jielan Zhou
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Xiaolu Chen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Jing Gan
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Qianyun Cai
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Tao Yu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
| | - Rong Luo
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan University, Chengdu, China
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De Meulemeester AS, Reid C, Auvin S, Carlen PL, Cole AJ, Szlendak R, Di Sapia R, Moshé SL, Sankar R, O'Brien TJ, Baulac S, Henshall DC, Akman Ö, Galanopoulou AS. WONOEP appraisal: Modeling early onset epilepsies. Epilepsia 2024. [PMID: 39042520 DOI: 10.1111/epi.18063] [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: 03/20/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/25/2024]
Abstract
Epilepsy has a peak incidence during the neonatal to early childhood period. These early onset epilepsies may be severe conditions frequently associated with comorbidities such as developmental deficits and intellectual disability and, in a significant percentage of patients, may be medication-resistant. The use of adult rodent models in the exploration of mechanisms and treatments for early life epilepsies is challenging, as it ignores significant age-specific developmental differences. More recently, models developed in immature animals, such as rodent pups, or in three-dimensional organoids may more closely model aspects of the immature brain and could result in more translatable findings. Although models are not perfect, they may offer a more controlled screening platform in studies of mechanisms and treatments, which cannot be done in pediatric patient cohorts. On the other hand, more simplified models with higher throughput capacities are required to deal with the large number of epilepsy candidate genes and the need for new treatment options. Therefore, a combination of different modeling approaches will be beneficial in addressing the unmet needs of pediatric epilepsy patients. In this review, we summarize the discussions on this topic that occurred during the XVI Workshop on Neurobiology of Epilepsy, organized in 2022 by the Neurobiology Commission of the International League Against Epilepsy. We provide an overview of selected models of early onset epilepsies, discussing their advantages and disadvantages. Heterologous expression models provide initial functional insights, and zebrafish, rodent models, and brain organoids present increasingly complex platforms for modeling and validating epilepsy-related phenomena. Together, these models offer valuable insights into early onset epilepsies and accelerate hypothesis generation and therapy discovery.
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Affiliation(s)
- Ann-Sofie De Meulemeester
- Institut du Cerveau-Paris Brain Institute-ICM, Institut National de la Santé et de la Recherche Médicale (INSERM), CNRS, Sorbonne Université, Paris, France
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | - Christopher Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
- Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Stéphane Auvin
- Pediatric Neurology Department, CRMR Épilepsies Rares, EpiCARE member, AP-HP, Robert-Debré University Hospital, Paris, France
- INSERM NeuroDiderot, Université Paris Cité, Paris, France
- Institut Universitaire de France, Paris, France
| | - Peter L Carlen
- Krembil Research Institute, Toronto, Ontario, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
- Department of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Andrew J Cole
- MGH Epilepsy Service, Division of Clinical Neurophysiology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Roza Szlendak
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
- Institut de Génomique Fonctionnelle, University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Rossella Di Sapia
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
- Isabelle Rapin Division of Child Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Raman Sankar
- Department of Neurology and Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Terence J O'Brien
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
| | - Stéphanie Baulac
- Institut du Cerveau-Paris Brain Institute-ICM, Institut National de la Santé et de la Recherche Médicale (INSERM), CNRS, Sorbonne Université, Paris, France
| | - David C Henshall
- FutureNeuro SFI Research Centre, Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences, Dublin, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences, Dublin, Ireland
| | - Özlem Akman
- Department of Physiology, Faculty of Medicine, Demiroglu Bilim University, Istanbul, Turkey
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
- Isabelle Rapin Division of Child Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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Pant K, Sharma A, Menon SV, Ali H, Hassan Almalki W, Kaur M, Deorari M, Kazmi I, Mahajan S, Kalra H, Alzarea SI. Exploring ncRNAs in epilepsy: From oxidative stress regulation to therapy. Brain Res 2024; 1841:149089. [PMID: 38880410 DOI: 10.1016/j.brainres.2024.149089] [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: 04/22/2024] [Revised: 06/10/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
Epilepsy is a prevalent neurological illness which is linked with high worldwide burdens. Oxidative stress (OS) is recognized to be among the contributors that trigger the advancement of epilepsy, affecting neuronal excitability and synaptic transmission. Various types of non-coding RNAs (ncRNAs) are known to serve vital functions in many disease mechanisms, including epilepsy. The current review sought to understand better the mechanisms through which these ncRNAs regulate epilepsy's OS-related pathways. We investigated the functions of microRNAs in controlling gene expression at the post-translatory stage and their involvement in OS and neuroinflammation. We also looked at the different regulatory roles of long ncRNAs, including molecular scaffolding, enhancer, and transcriptional activator, during OS. Circular RNAs and their capability to act as miRNA decoys and their consequential impact on epilepsy development were also explored. Our review aimed to improve the current understanding of novel therapies for epilepsy based on the role of ncRNAs in OS pathways. We also demonstrated the roles of ncRNAs in epilepsy treatment and diagnosis, explaining that these molecules play vital roles that could be used in therapy as biomarkers.
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Affiliation(s)
- Kumud Pant
- Graphic Era (Deemed to be University), Clement Town Dehradun, 248002, India; Graphic Era Hill University Clement Town Dehradun, 248002, India
| | - Aanchal Sharma
- Chandigarh Pharmacy College, Chandigarh Group of Colleges, Jhanjheri, Mohali 140307, Punjab, India
| | - Soumya V Menon
- Department of Biotechnology and Genetics, Jain (Deemed-to-be) University, Bengaluru, Karnataka 560069, India; Department of Allied Healthcare and Sciences, Vivekananda Global University, Jaipur, Rajasthan 303012, India
| | - Haider Ali
- Centre for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, India; Department of Pharmacology, Kyrgyz State Medical College, Bishkek, Kyrgyzstan.
| | - Waleed Hassan Almalki
- Department of Pharmacology, College of Pharmacy, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Mandeep Kaur
- Department of Sciences, Vivekananda Global University, Jaipur, Rajasthan 303012, India
| | - Mahamedha Deorari
- School of Basic & Applied Sciences, Shobhit University, Gangoh, Uttar Pradesh-247341, India; Department of Health & Allied Sciences, Arka Jain University, Jamshedpur, Jharkhand- 831001, India
| | - Imran Kazmi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
| | - Shriya Mahajan
- Centre of Research Impact and Outcome, Chitkara University, Rajpura 140417, Punjab, India
| | - Hitesh Kalra
- Chitkara Centre for Research and Development, Chitkara University, Himachal Pradesh 174103, India
| | - Sami I Alzarea
- Department of Pharmacology, College of Pharmacy, Jouf University, 72341, Sakaka, Aljouf, Saudi Arabia
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Whyte-Fagundes PA, Vance A, Carroll A, Figueroa F, Manukyan C, Baraban SC. Testing of putative antiseizure medications in a preclinical Dravet syndrome zebrafish model. Brain Commun 2024; 6:fcae135. [PMID: 38707709 PMCID: PMC11069116 DOI: 10.1093/braincomms/fcae135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/27/2024] [Accepted: 04/12/2024] [Indexed: 05/07/2024] Open
Abstract
Dravet syndrome is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications. Preclinical Dravet syndrome animal models are a valuable tool to identify candidate anti-seizure medications for these patients. Among these, scn1lab mutant zebrafish, exhibiting spontaneous seizure-like activity, are particularly amenable to large-scale drug screening. Thus far, we have screened more than 3000 drug candidates in scn1lab zebrafish mutants, identifying valproate, stiripentol, and fenfluramine e.g. Food and Drug Administration-approved drugs, with clinical application in the Dravet syndrome population. Successful phenotypic screening in scn1lab mutant zebrafish is rigorous and consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behaviour and (ii) an electrophysiology-based assay, using in vivo local field potential recordings, to quantify electrographic seizure-like events. Historically, nearly 90% of drug candidates fail during translation from preclinical models to the clinic. With such a high failure rate, it becomes necessary to address issues of replication and false positive identification. Leveraging our scn1lab zebrafish assays is one approach to address these problems. Here, we curated a list of nine anti-seizure drug candidates recently identified by other groups using preclinical Dravet syndrome models: 1-Ethyl-2-benzimidazolinone, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-Ethyl-2-benzimidazolinone, chlorzoxazone and lisuride. However, second-stage local field potential recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of anti-seizure medications.
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Affiliation(s)
- Paige A Whyte-Fagundes
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Anjelica Vance
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Aloe Carroll
- Behavioral Neurosciences, Northeastern University, Boston, MA 02115, USA
| | - Francisco Figueroa
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Catherine Manukyan
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
| | - Scott C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
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Ilyin NP, Petersen EV, Kolesnikova TO, Demin KA, Khatsko SL, Apuhtin KV, Kalueff AV. Developing Peripheral Biochemical Biomarkers of Brain Disorders: Insights from Zebrafish Models. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:377-391. [PMID: 38622104 DOI: 10.1134/s0006297924020160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/09/2024] [Accepted: 02/13/2024] [Indexed: 04/17/2024]
Abstract
High prevalence of human brain disorders necessitates development of the reliable peripheral biomarkers as diagnostic and disease-monitoring tools. In addition to clinical studies, animal models markedly advance studying of non-brain abnormalities associated with brain pathogenesis. The zebrafish (Danio rerio) is becoming increasingly popular as an animal model organism in translational neuroscience. These fish share some practical advantages over mammalian models together with high genetic homology and evolutionarily conserved biochemical and neurobehavioral phenotypes, thus enabling large-scale modeling of human brain diseases. Here, we review mounting evidence on peripheral biomarkers of brain disorders in zebrafish models, focusing on altered biochemistry (lipids, carbohydrates, proteins, and other non-signal molecules, as well as metabolic reactions and activity of enzymes). Collectively, these data strongly support the utility of zebrafish (from a systems biology standpoint) to study peripheral manifestations of brain disorders, as well as highlight potential applications of biochemical biomarkers in zebrafish models to biomarker-based drug discovery and development.
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Affiliation(s)
- Nikita P Ilyin
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199034, Russia.
| | - Elena V Petersen
- Moscow Institute of Physics and Technology, Moscow, 115184, Russia.
| | - Tatyana O Kolesnikova
- Neuroscience Program, Sirius University of Science and Technology, Sochi, 354340, Russia.
| | - Konstantin A Demin
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199034, Russia.
- Moscow Institute of Physics and Technology, Moscow, 115184, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of the Russian Federation, St. Petersburg, 197341, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the Russian Federation, Pesochny, 197758, Russia
| | | | - Kirill V Apuhtin
- Laboratory of Biopsychiatry, Scientific Research Institute of Neurosciences and Medicine, Novosibirsk, 630117, Russia.
- Neuroscience Division, Sirius University of Science and Technology, Sirius Federal Territory, 354340, Russia
| | - Allan V Kalueff
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199034, Russia.
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of the Russian Federation, St. Petersburg, 197341, Russia
- Ural Federal University, Ekaterinburg, 620002, Russia
- Laboratory of Biopsychiatry, Scientific Research Institute of Neurosciences and Medicine, Novosibirsk, 630117, Russia
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Sui J, Zhan L, Ji S, Wu W, Chen Y, Yun F, Liang W, Wang J, Cao M, Shen D, Zhang Q. Differential inflammation responses determine the variable phenotypes of epilepsy induced by GABRG2 mutations. CNS Neurosci Ther 2024; 30:e14583. [PMID: 38357846 PMCID: PMC10867793 DOI: 10.1111/cns.14583] [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: 10/19/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 02/16/2024] Open
Abstract
OBJECTIVE To explore the mechanism involved in variable phenotypes of epilepsy models induced by γ-aminobutyric acid type A γ2 subunit (GABRG2) mutations. METHODS The zebrafish carrying wild-type (WT) GABRG2, mutant GABRG2(P282S), GABRG2(F343L) and GABRG2(I107T) were established by Tol2kit transgenesis system and Gateway method. Behavioral analysis of different transgenic zebrafish was performed with the DanioVision Video-Track framework and the brain activity was analyzed by field potential recording with MD3000 Bio-signal Acquisition and Processing System. The transcriptome analysis was applied to detect the underlying mechanisms of variable phenotypes caused by different GABRG2 mutations. RESULTS The established Tg(hGABRG2P282S ) zebrafish showed hyperactivity and spontaneous seizures, which were more sensitive to chemical and physical epileptic stimulations. Traditional antiepileptic drugs, such as Clonazepam (CBZ) and valproic acid (VPA), could ameliorate the hyperactivity in Tg(hGABRG2P282S ) zebrafish. The metabolic pathway was significantly changed in the brain transcriptome of Tg(hGABRG2P282S ) zebrafish. In addition, the behavioral activity, production of pro-inflammatory factors, and activation of the IL-2 receptor signal pathway varied among the three mutant zebrafish lines. CONCLUSION We successfully established transgenic zebrafish epileptic models expressing human mutant GABRG2(P282S), in which CBZ and VPA showed antiepileptic effects. Differential inflammatory responses, especially the SOCS/JAK/STAT signaling pathway, might be related to the phenotypes of genetic epilepsy induced by GABRG2 mutations. Further study will expand the pathological mechanisms of genetic epilepsies and provide a theoretical basis for searching for effective drug treatment.
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Affiliation(s)
- Jiahui Sui
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Longwu Zhan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Shengtao Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Wenwen Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Yuhan Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Feng Yun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Wenpeng Liang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Jie Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Maohong Cao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Dingding Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Department of NeurologyAffiliated Hospital of Nantong University, Medical School, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong UniversityNantongChina
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Whyte-Fagundes P, Vance A, Carroll A, Figueroa F, Manukyan C, Baraban SC. Testing of putative antiseizure drugs in a preclinical Dravet syndrome zebrafish model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566723. [PMID: 38014342 PMCID: PMC10680609 DOI: 10.1101/2023.11.11.566723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Dravet syndrome (DS) is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications (ASM). Preclinical DS animal models are a valuable tool to identify candidate ASMs for these patients. Among these, scn1lab mutant zebrafish exhibiting spontaneous seizure-like activity are particularly amenable to large-scale drug screening. Prior screening in a scn1lab mutant zebrafish line generated using N-ethyl-Nnitrosourea (ENU) identified valproate, stiripentol, and fenfluramine e.g., Federal Drug Administration (FDA) approved drugs with clinical application in the DS population. Successful phenotypic screening in scn1lab mutant zebrafish consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behavior and (ii) an electrophysiology-based assay, using in vivo local field potential (LFP) recordings, to quantify electrographic seizure-like events. Using this strategy more than 3000 drug candidates have been screened in scn1lab zebrafish mutants. Here, we curated a list of nine additional anti-seizure drug candidates recently identified in preclinical models: 1-EBIO, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-EBIO, chlorzoxazone and lisuride. However, second-stage LFP recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of ASMs.
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Affiliation(s)
- P Whyte-Fagundes
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Vance
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Carroll
- Behavioral Neurosciences, Northeastern University, Boston, MA, USA
| | - F Figueroa
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - C Manukyan
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - S C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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Sri Hari A, Banerji R, Liang LP, Fulton RE, Huynh CQ, Fabisiak T, McElroy PB, Roede JR, Patel M. Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability. Redox Biol 2023; 67:102895. [PMID: 37769522 PMCID: PMC10539966 DOI: 10.1016/j.redox.2023.102895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/14/2023] [Accepted: 09/18/2023] [Indexed: 10/02/2023] Open
Abstract
Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.
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Affiliation(s)
- Ashwini Sri Hari
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Rajeswari Banerji
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Li-Ping Liang
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Ruth E Fulton
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Christopher Quoc Huynh
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Timothy Fabisiak
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Pallavi Bhuyan McElroy
- The Janssen Pharmaceutical Companies of Johnson & Johnson, Greater Philadelphia Area, Horsham, PA, 19044, USA
| | - James R Roede
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA.
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9
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Dogra D, Meza-Santoscoy PL, Gavrilovici C, Rehak R, de la Hoz CLR, Ibhazehiebo K, Rho JM, Kurrasch DM. kcna1a mutant zebrafish model episodic ataxia type 1 (EA1) with epilepsy and show response to first-line therapy carbamazepine. Epilepsia 2023; 64:2186-2199. [PMID: 37209379 DOI: 10.1111/epi.17659] [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: 09/28/2022] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 05/22/2023]
Abstract
OBJECTIVE KCNA1 mutations are associated with a rare neurological movement disorder known as episodic ataxia type 1 (EA1), and epilepsy is a common comorbidity. Current medications provide only partial relief for ataxia and/or seizures, making new drugs needed. Here, we characterized zebrafish kcna1a-/- as a model of EA1 with epilepsy and compared the efficacy of the first-line therapy carbamazepine in kcna1a-/- zebrafish to Kcna1-/- rodents. METHODS CRISPR/Cas9 mutagenesis was used to introduce a mutation in the sixth transmembrane segment of the zebrafish Kcna1 protein. Behavioral and electrophysiological assays were performed on kcna1a-/- larvae to assess ataxia- and epilepsy-related phenotypes. Real-time quantitative polymerase chain reaction (qPCR) was conducted to measure mRNA levels of brain hyperexcitability markers in kcna1a-/- larvae, followed by bioenergetics profiling to evaluate metabolic function. Drug efficacies were tested using behavioral and electrophysiological assessments, as well as seizure frequency in kcna1a-/- zebrafish and Kcna1-/- mice, respectively. RESULTS Zebrafish kcna1a-/- larvae showed uncoordinated movements and locomotor deficits, along with scoliosis and increased mortality. The mutants also exhibited impaired startle responses when exposed to light-dark flashes and acoustic stimulation as well as hyperexcitability as measured by extracellular field recordings and upregulated fosab transcripts. Neural vglut2a and gad1b transcript levels were disrupted in kcna1a-/- larvae, indicative of a neuronal excitatory/inhibitory imbalance, as well as a significant reduction in cellular respiration in kcna1a-/- , consistent with dysregulation of neurometabolism. Notably, carbamazepine suppressed the impaired startle response and brain hyperexcitability in kcna1a-/- zebrafish but had no effect on the seizure frequency in Kcna1-/- mice, suggesting that this EA1 zebrafish model might better translate to humans than rodents. SIGNIFICANCE We conclude that zebrafish kcna1a-/- show ataxia and epilepsy-related phenotypes and are responsive to carbamazepine treatment, consistent with EA1 patients. These findings suggest that kcna1-/- zebrafish are a useful model for drug screening as well as studying the underlying disease biology.
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Affiliation(s)
- Deepika Dogra
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Paola L Meza-Santoscoy
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Cezar Gavrilovici
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Departments of Pediatrics, Clinical Neurosciences, Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Departments of Neurosciences, Pediatrics, and Pharmacology, Rady Children's Hospital San Diego, University of California San Diego, San Diego, California, USA
| | - Renata Rehak
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Cristiane L R de la Hoz
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Kingsley Ibhazehiebo
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jong M Rho
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Departments of Pediatrics, Clinical Neurosciences, Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Departments of Neurosciences, Pediatrics, and Pharmacology, Rady Children's Hospital San Diego, University of California San Diego, San Diego, California, USA
| | - Deborah M Kurrasch
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
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10
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Otsuka T, Matsui H. Fish Models for Exploring Mitochondrial Dysfunction Affecting Neurodegenerative Disorders. Int J Mol Sci 2023; 24:ijms24087079. [PMID: 37108237 PMCID: PMC10138900 DOI: 10.3390/ijms24087079] [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: 03/16/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Neurodegenerative disorders are characterized by the progressive loss of neuronal structure or function, resulting in memory loss and movement disorders. Although the detailed pathogenic mechanism has not been elucidated, it is thought to be related to the loss of mitochondrial function in the process of aging. Animal models that mimic the pathology of a disease are essential for understanding human diseases. In recent years, small fish have become ideal vertebrate models for human disease due to their high genetic and histological homology to humans, ease of in vivo imaging, and ease of genetic manipulation. In this review, we first outline the impact of mitochondrial dysfunction on the progression of neurodegenerative diseases. Then, we highlight the advantages of small fish as model organisms, and present examples of previous studies regarding mitochondria-related neuronal disorders. Lastly, we discuss the applicability of the turquoise killifish, a unique model for aging research, as a model for neurodegenerative diseases. Small fish models are expected to advance our understanding of the mitochondrial function in vivo, the pathogenesis of neurodegenerative diseases, and be important tools for developing therapies to treat diseases.
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Affiliation(s)
- Takayoshi Otsuka
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Hideaki Matsui
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
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11
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The Generation of Human iPSC Lines from Three Individuals with Dravet Syndrome and Characterization of Neural Differentiation Markers in iPSC-Derived Ventral Forebrain Organoid Model. Cells 2023; 12:cells12020339. [PMID: 36672274 PMCID: PMC9856691 DOI: 10.3390/cells12020339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/02/2023] [Accepted: 01/07/2023] [Indexed: 01/18/2023] Open
Abstract
Dravet syndrome (DRVT) is a rare form of neurodevelopmental disorder with a high risk of sudden unexpected death in epilepsy (SUDEP), caused mainly (>80% cases) by mutations in the SCN1A gene, coding the Nav1.1 protein (alfa-subunit of voltage-sensitive sodium channel). Mutations in SCN1A are linked to heterogenous epileptic phenotypes of various types, severity, and patient prognosis. Here we generated iPSC lines from fibroblasts obtained from three individuals affected with DRVT carrying distinct mutations in the SCN1A gene (nonsense mutation p.Ser1516*, missense mutation p.Arg1596His, and splicing mutation c.2589+2dupT). The iPSC lines, generated with the non-integrative approach, retained the distinct SCN1A gene mutation of the donor fibroblasts and were characterized by confirming the expression of the pluripotency markers, the three-germ layer differentiation potential, the absence of exogenous vector expression, and a normal karyotype. The generated iPSC lines were used to establish ventral forebrain organoids, the most affected type of neurons in the pathology of DRVT. The DRVT organoid model will provide an additional resource for deciphering the pathology behind Nav1.1 haploinsufficiency and drug screening to remediate the functional deficits associated with the disease.
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12
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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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13
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Fabisiak T, Patel M. Crosstalk between neuroinflammation and oxidative stress in epilepsy. Front Cell Dev Biol 2022; 10:976953. [PMID: 36035987 PMCID: PMC9399352 DOI: 10.3389/fcell.2022.976953] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
The roles of both neuroinflammation and oxidative stress in the pathophysiology of epilepsy have begun to receive considerable attention in recent years. However, these concepts are predominantly studied as separate entities despite the evidence that neuroinflammatory and redox-based signaling cascades have significant crosstalk. Oxidative post-translational modifications have been demonstrated to directly influence the function of key neuroinflammatory mediators. Neuroinflammation can further be controlled on the transcriptional level as the transcriptional regulators NF-KB and nrf2 are activated by reactive oxygen species. Further, neuroinflammation can induce the increased expression and activity of NADPH oxidase, leading to a highly oxidative environment. These factors additionally influence mitochondria function and the metabolic status of neurons and glia, which are already metabolically stressed in epilepsy. Given the implication of this relationship to disease pathology, this review explores the numerous mechanisms by which neuroinflammation and oxidative stress influence one another in the context of epilepsy. We further examine the efficacy of treatments targeting oxidative stress and redox regulation in animal and human epilepsies in the literature that warrant further investigation. Treatment approaches aimed at rectifying oxidative stress and aberrant redox signaling may enable control of neuroinflammation and improve patient outcomes.
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14
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USE OF KETOGENIC DIET THERAPY IN EPILEPSY WITH MITOCHONDRIAL DYSFUNCTION: A SYSTEMATIC AND CRITICAL REVIEW. BIOTECHNOLOGIA ACTA 2022. [DOI: 10.15407/biotech15.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
With the development of molecular techniques over time more than %60 of epilepsy has associated with mitochondrial (mt) dysfunction. Ketogenic diet (KD) has been used in the treatment of epilepsy since the 1920s. Aim. To evaluate the evidence behind KD in mt dysfunction in epilepsy. Methods. Databases PubMed, Google Scholar and MEDLINE were searched in an umbrella approach to 12 March 2021 in English. To identify relevant studies specific search strategies were devised for the following topics: (1) mitochondrial dysfunction (2) epilepsy (3) KD treatment. Results. From 1794 papers, 36 articles were included in analysis: 16 (%44.44) preclinical studies, 11 (%30.55) case reports, 9 (%25) clinical studies. In all the preclinic studies, KD regulated the number of mt profiles, transcripts of metabolic enzymes and encoding mt proteins, protected the mice against to seizures and had an anticonvulsant mechanism. Case reports and clinical trials have reported patients with good results in seizure control and mt functions, although not all of them give good results as well as preclinical. Conclusion. Healthcare institutions, researchers, neurologists, health promotion organizations, and dietitians should consider these results to improve KD programs and disease outcomes for mt dysfunction in epilepsy.
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15
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Abstract
The brain is a highly energy-demanding organ and requires bioenergetic adaptability to balance normal activity with pathophysiological fuelling of spontaneous recurrent seizures, the hallmark feature of the epilepsies. Recurrent or prolonged seizures have long been known to permanently alter neuronal circuitry and to cause excitotoxic injury and aberrant inflammation. Furthermore, pathological changes in bioenergetics and metabolism are considered downstream consequences of epileptic seizures that begin at the synaptic level. However, as we highlight in this Review, evidence is also emerging that primary derangements in cellular or mitochondrial metabolism can result in seizure genesis and lead to spontaneous recurrent seizures. Basic and translational research indicates that the relationships between brain metabolism and epileptic seizures are complex and bidirectional, producing a vicious cycle that compounds the deleterious consequences of seizures. Metabolism-based treatments such as the high-fat, antiseizure ketogenic diet have become mainstream, and metabolic substrates and enzymes have become attractive molecular targets for seizure prevention and recovery. Moreover, given that metabolism is crucial for epigenetic as well as inflammatory changes, the idea that epileptogenesis can be both negatively and positively influenced by metabolic changes is rapidly gaining ground. Here, we review evidence that supports both pathophysiological and therapeutic roles for brain metabolism in epilepsy.
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16
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2022 Overview of Metabolic Epilepsies. Genes (Basel) 2022; 13:genes13030508. [PMID: 35328062 PMCID: PMC8952328 DOI: 10.3390/genes13030508] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/04/2022] Open
Abstract
Understanding the genetic architecture of metabolic epilepsies is of paramount importance, both to current clinical practice and for the identification of further research directions. The main goals of our study were to identify the scope of metabolic epilepsies and to investigate their clinical presentation, diagnostic approaches and treatments. The International Classification of Inherited Metabolic Disorders and IEMbase were used as a basis for the identification and classification of metabolic epilepsies. Six hundred metabolic epilepsies have been identified, accounting for as much as 37% of all currently described inherited metabolic diseases (IMD). Epilepsy is a particularly common symptom in disorders of energy metabolism, congenital disorders of glycosylation, neurotransmitter disorders, disorders of the synaptic vesicle cycle and some other IMDs. Seizures in metabolic epilepsies may present variably, and most of these disorders are complex and multisystem. Abnormalities in routine laboratory tests and/or metabolic testing may be identified in 70% of all metabolic epilepsies, but in many cases they are non-specific. In total, 111 metabolic epilepsies (18% of all) have specific treatments that may significantly change health outcomes if diagnosed in time. Although metabolic epilepsies comprise an important and significant group of disorders, their real scope and frequency may have been underestimated.
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17
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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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18
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Tapia A, Giachello CN, Palomino-Schätzlein M, Baines RA, Galindo MI. Generation and Characterization of the Drosophila melanogaster paralytic Gene Knock-Out as a Model for Dravet Syndrome. Life (Basel) 2021; 11:life11111261. [PMID: 34833136 PMCID: PMC8619338 DOI: 10.3390/life11111261] [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: 10/01/2021] [Revised: 11/11/2021] [Accepted: 11/17/2021] [Indexed: 12/13/2022] Open
Abstract
Dravet syndrome is a severe rare epileptic disease caused by mutations in the SCN1A gene coding for the Nav1.1 protein, a voltage-gated sodium channel alpha subunit. We have made a knock-out of the paralytic gene, the single Drosophila melanogaster gene encoding this type of protein, by homologous recombination. These flies showed a heat-induced seizing phenotype, and sudden death in long term seizures. In addition to seizures, neuromuscular alterations were observed in climbing, flight, and walking tests. Moreover, they also manifested some cognitive alterations, such as anxiety and problems in learning. Electrophysiological analyses from larval motor neurons showed a decrease in cell capacitance and membrane excitability, while persistent sodium current increased. To detect alterations in metabolism, we performed an NMR metabolomic profiling of heads, which revealed higher levels in some amino acids, succinate, and lactate; and also an increase in the abundance of GABA, which is the main neurotransmitter implicated in Dravet syndrome. All these changes in the paralytic knock-out flies indicate that this is a good model for epilepsy and specifically for Dravet syndrome. This model could be a new tool to understand the pathophysiology of the disease and to find biomarkers, genetic modifiers and new treatments.
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Affiliation(s)
- Andrea Tapia
- Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain; (A.T.); (M.P.-S.)
| | - Carlo N. Giachello
- Manchester Academic Health Science Centre, Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (C.N.G.); (R.A.B.)
| | | | - Richard A. Baines
- Manchester Academic Health Science Centre, Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (C.N.G.); (R.A.B.)
| | - Máximo Ibo Galindo
- Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain; (A.T.); (M.P.-S.)
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022 Valencia, Spain
- UPV-CIPF Joint Unit Disease Mechanisms and Nanomedicine, 46012 Valencia, Spain
- Correspondence:
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Lu D, Ma R, Xie Q, Xu Z, Yuan J, Ren M, Li J, Li Y, Wang J. Application and advantages of zebrafish model in the study of neurovascular unit. Eur J Pharmacol 2021; 910:174483. [PMID: 34481878 DOI: 10.1016/j.ejphar.2021.174483] [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: 07/14/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 11/15/2022]
Abstract
The concept of "Neurovascular Unit" (NVU) was put forward, so that the research goal of Central Nervous System (CNS) diseases gradually transitioned from a single neuron to the structural and functional integrity of the NVU. Zebrafish has the advantages of high homology with human genes, strong reproductive capacity and visualization of neural circuits, so it has become an emerging model organism for NVU research and has been applied to a variety of CNS diseases. Based on CNKI (https://www.cnki.net/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/about/) databases, the author of this article sorted out the relevant literature, analyzed the construction of a zebrafish model of various CNS diseases,and the use of diagrams showed the application of zebrafish in the NVU, revealed its relationship, which would provide new methods and references for the treatment and research of CNS diseases.
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Affiliation(s)
- Danni Lu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Rong Ma
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Qian Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Zhuo Xu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jianmei Yuan
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Mihong Ren
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jinxiu Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Yong Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jian Wang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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20
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Jancovski N, Baldwin T, Orford M, Li M, Jones GD, Burbano LE, Rutherford T, Reid C, Heales S, Eaton S, Petrou S. Protective effects of medium chain triglyceride diet in a mouse model of Dravet syndrome. Epilepsia 2021; 62:3131-3142. [PMID: 34713469 DOI: 10.1111/epi.17101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 09/27/2021] [Accepted: 10/05/2021] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with early childhood onset. Patients with DS do not respond well to antiepileptic drugs and have only a few treatment options available. Here, we evaluated the effect of medium chain triglyceride (MCT) diet therapy in a mouse model of DS. METHODS Scn1aR1407X/+ DS mice were given diets supplemented with MCTs with varying ratios of decanoic (C10) and octanoic (C8) acid or a control diet for 4 weeks. Video monitoring was performed to evaluate spontaneous convulsive seizure frequency. Susceptibility to hyperthermia-induced seizures was also examined. Medium chain fatty acids, and mitochondrial and antioxidant markers were assessed in brain homogenate. RESULTS Dietary intervention with MCTs significantly prolonged survival and reduced convulsive seizure frequency during the critical period of highest seizure occurrence in the Scn1aR1407X/+ DS mice. Moreover, MCT diet therapy showed protective effects against hyperthermia-induced seizures. We demonstrated that coadministration of C10/C8 was effective at reducing both seizures and mortality, whereas C10 alone only reduced mortality, suggesting that the ratio of C10 to C8 in the MCT is an important factor for efficacy. When C10 and C8 are supplemented at an 80:20 ratio in the diet, C10 accumulates in the brain in high enough concentrations to enhance brain energy metabolism by both stimulating mitochondrial enrichment and increasing its antioxidant status. SIGNIFICANCE The results from this study indicate that MCT diet therapy may provide therapeutic benefits in DS. Future clinical studies would elucidate whether these positive effects are mirrored in human patients.
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Affiliation(s)
- Nikola Jancovski
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Tomas Baldwin
- Developmental Biology and Cancer University College London Great Ormond Street Institute of Child Health, London, UK
| | - Michael Orford
- Developmental Biology and Cancer University College London Great Ormond Street Institute of Child Health, London, UK
| | - Melody Li
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Gabriel Davis Jones
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Lisseth Estefania Burbano
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | | | - Christopher Reid
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Simon Heales
- Inborn Errors of Metabolism, Chemical Pathology, University College London Metabolism, Great Ormond Street for Children Hospital, Chemical Pathology, Great Ormond Street Hospital, London, UK.,Neurometabolic Unit, National Hospital, London, UK
| | - Simon Eaton
- Developmental Biology and Cancer University College London Great Ormond Street Institute of Child Health, London, UK
| | - Steven Petrou
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
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21
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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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22
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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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23
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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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24
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Pedersen AF, Meyer DN, Petriv AMV, Soto AL, Shields JN, Akemann C, Baker BB, Tsou WL, Zhang Y, Baker TR. Nanoplastics impact the zebrafish (Danio rerio) transcriptome: Associated developmental and neurobehavioral consequences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115090. [PMID: 32693326 PMCID: PMC7492438 DOI: 10.1016/j.envpol.2020.115090] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/05/2020] [Accepted: 06/22/2020] [Indexed: 05/20/2023]
Abstract
Microplastics (MPs) are a ubiquitous pollutant detected not only in marine and freshwater bodies, but also in tap and bottled water worldwide. While MPs have been extensively studied, the toxicity of their smaller counterpart, nanoplastics (NPs), is not well documented. Despite likely large-scale human and animal exposure to NPs, the associated health risks remain unclear, especially during early developmental stages. To address this, we investigated the health impacts of exposures to both 50 and 200 nm polystyrene NPs in larval zebrafish. From 6 to 120 h post-fertilization (hpf), developing zebrafish were exposed to a range of fluorescent NPs (10-10,000 parts per billion). Dose-dependent increases in accumulation were identified in exposed larval fish, potentially coinciding with an altered behavioral response as evidenced through swimming hyperactivity. Notably, exposures did not impact mortality, hatching rate, or deformities; however, transcriptomic analysis suggests neurodegeneration and motor dysfunction at both high and low concentrations. Furthermore, results of this study suggest that NPs can accumulate in the tissues of larval zebrafish, alter their transcriptome, and affect behavior and physiology, potentially decreasing organismal fitness in contaminated ecosystems. The uniquely broad scale of this study during a critical window of development provides crucial multidimensional characterization of NP impacts on human and animal health.
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Affiliation(s)
- Adam F Pedersen
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Danielle N Meyer
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Anna-Maria V Petriv
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Abraham L Soto
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Jeremiah N Shields
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Camille Akemann
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Bridget B Baker
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Wei-Ling Tsou
- Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Yongli Zhang
- College of Engineering, Wayne State University, 5050 Anthony Wayne Dr, Detroit, MI, 28201, USA
| | - Tracie R Baker
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA.
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25
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Murugan M, Boison D. Ketogenic diet, neuroprotection, and antiepileptogenesis. Epilepsy Res 2020; 167:106444. [PMID: 32854046 PMCID: PMC7655615 DOI: 10.1016/j.eplepsyres.2020.106444] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/30/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022]
Abstract
High fat, low carbohydrate ketogenic diets (KD) have been in use for the treatment of epilepsy for almost a hundred years. Remarkably, seizures that are resistant to conventional anti-seizure drugs can in many cases be controlled by the KD therapy, and it has been shown that many patients with epilepsy become seizure free even after discontinuation of the diet. These findings suggest that KD combine anti-seizure effects with disease modifying effects. In addition to the treatment of epilepsy, KDs are now widely used for the treatment of a wide range of conditions including weight reduction, diabetes, and cancer. The reason for the success of metabolic therapies is based on the synergism of at least a dozen different mechanisms through which KDs provide beneficial activities. Among the newest findings are epigenetic mechanisms (DNA methylation and histone acetylation) through which KD exerts long-lasting disease modifying effects. Here we review mechanisms through which KD can affect neuroprotection in the brain, and how a combination of those mechanisms with epigenetic alterations can attenuate and possibly reverse the development of epilepsy.
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Affiliation(s)
- Madhuvika Murugan
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, United States
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, United States; Department of Neurosurgery, New Jersey Medical School, Rutgers University, Newark, NJ 07102, United States; Rutgers Neurosurgery H.O.P.E. Center, Department of Neurosurgery, Rutgers University, New Brunswick, NJ 08901, United States.
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26
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Martínez R, Tu W, Eng T, Allaire-Leung M, Piña B, Navarro-Martín L, Mennigen JA. Acute and long-term metabolic consequences of early developmental Bisphenol A exposure in zebrafish (Danio rerio). CHEMOSPHERE 2020; 256:127080. [PMID: 32450349 DOI: 10.1016/j.chemosphere.2020.127080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 05/22/2023]
Abstract
Bisphenol A (BPA) is an estrogenic contaminant linked to metabolic disruption. Developmental BPA exposure is of particular concern, as organizational effects may irreversibly disrupt metabolism at later life-stages. While BPA exposures in adult fish elicit metabolic perturbations similar to effects described in rodents, the metabolic effects of developmental BPA exposure in juvenile fish remain largely unknown. Following embryonic zebrafish exposure to BPA (0.1, 1 and 4 mg/L) and EE2 (10 ng/L) from 2 to 5 dpf, we assessed the metabolic phenotype in larvae (4-6 dpf) and juveniles (43-49 dpf) which had been divided into regular-fed and overfed groups at 29 dpf. Developmental BPA exposure in larvae dose-dependently reduced food-intake and locomotion and increased energy expenditure. Juveniles (29 dpf) exhibited a transient increase in body weight after developmental BPA exposure and persistent diet-dependent locomotion changes (43-49 dpf). At the molecular level, glucose and lipid metabolism-related transcript abundance clearly separated BPA exposed fish from controls and EE2 exposed fish at the larval stage, in juveniles on a regular diet and, to a lesser extent, in overfed juveniles. In general, the metabolic endpoints affected by BPA exposure were not mimicked by EE2 treatment. We conclude that developmental BPA exposure elicits acute metabolic effects in zebrafish larvae and fewer transient and persistent effects in juveniles and that these metabolic effects are largely independent of BPA's estrogenicity.
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Affiliation(s)
- Rubén Martínez
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Jordi Girona, Barcelona, Spain; Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona (UB), Barcelona, Spain
| | - Wenqing Tu
- Research Institute of Poyang Lake, Jiangxi Academy of Sciences, Nanchang 330012, China
| | - Tyler Eng
- Department of Biology, University of Ottawa, 20 Marie-Curie K1N 6N5, Ottawa, Ontario, Canada
| | - Melissa Allaire-Leung
- Department of Biology, University of Ottawa, 20 Marie-Curie K1N 6N5, Ottawa, Ontario, Canada
| | - Benjamin Piña
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Jordi Girona, Barcelona, Spain
| | - Laia Navarro-Martín
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Jordi Girona, Barcelona, Spain
| | - Jan A Mennigen
- Department of Biology, University of Ottawa, 20 Marie-Curie K1N 6N5, Ottawa, Ontario, Canada.
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27
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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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28
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Kundap UP, Paudel YN, Shaikh MF. Animal Models of Metabolic Epilepsy and Epilepsy Associated Metabolic Dysfunction: A Systematic Review. Pharmaceuticals (Basel) 2020; 13:ph13060106. [PMID: 32466498 PMCID: PMC7345684 DOI: 10.3390/ph13060106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a serious neurological disorder affecting around 70 million people globally and is characterized by spontaneous recurrent seizures. Recent evidence indicates that dysfunction in metabolic processes can lead to the alteration of neuronal and network excitability, thereby contributing to epileptogenesis. Developing a suitable animal model that can recapitulate all the clinical phenotypes of human metabolic epilepsy (ME) is crucial yet challenging. The specific environment of many symptoms as well as the primary state of the applicable neurobiology, genetics, and lack of valid biomarkers/diagnostic tests are the key factors that hinder the process of developing a suitable animal model. The present systematic review summarizes the current state of available animal models of metabolic dysfunction associated with epileptic disorders. A systematic search was performed by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model. A range of electronic databases, including google scholar, Springer, PubMed, ScienceDirect, and Scopus, were scanned between January 2000 and April 2020. Based on the selection criteria, 23 eligible articles were chosen and are discussed in the current review. Critical analysis of the selected literature delineated several available approaches that have been modeled into metabolic epilepsy and pointed out several drawbacks associated with the currently available models. The result describes available models of metabolic dysfunction associated with epileptic disorder, such as mitochondrial respiration deficits, Lafora disease (LD) model-altered glycogen metabolism, causing epilepsy, glucose transporter 1 (GLUT1) deficiency, adiponectin responsive seizures, phospholipid dysfunction, glutaric aciduria, mitochondrial disorders, pyruvate dehydrogenase (PDH) α-subunit gene (PDHA1), pyridoxine dependent epilepsy (PDE), BCL2-associated agonist of cell death (BAD), Kcna1 knock out (KO), and long noncoding RNAs (lncRNA) cancer susceptibility candidate 2 (lncRNA CASC2). Finally, the review highlights certain focus areas that may increase the possibilities of developing more suitable animal models and underscores the importance of the rationalization of animal models and evaluation methods for studying ME. The review also suggests the pressing need of developing precise robust animal models and evaluation methods for investigating ME.
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Affiliation(s)
- Uday Praful Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
| | - Yam Nath Paudel
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
- Correspondence: ; Tel.: +60-3-551-44-483
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29
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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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30
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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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31
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Perry CJ, Finch P, Müller‐Taubenberger A, Leung K, Warren EC, Damstra‐Oddy J, Sharma D, Patra PH, Glyn S, Boberska J, Stewart B, Baldwin A, Piscitelli F, Harvey RJ, Harwood A, Thompson C, Claus SP, Greene ND, McNeish AJ, Williams CM, Whalley BJ, Williams RS. A new mechanism for cannabidiol in regulating the one-carbon cycle and methionine levels in Dictyostelium and in mammalian epilepsy models. Br J Pharmacol 2020; 177:912-928. [PMID: 31693171 PMCID: PMC7024701 DOI: 10.1111/bph.14892] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Epidiolex™, a form of highly purified cannabidiol (CBD) derived from Cannabis plants, has demonstrated seizure control activity in patients with Dravet syndrome, without a fully elucidated mechanism of action. We have employed an unbiased approach to investigate this mechanism at a cellular level. EXPERIMENTAL APPROACH We use a tractable biomedical model organism, Dictyostelium, to identify a protein controlling the effect of CBD and characterize this mechanism. We then translate these results to a Dravet syndrome mouse model and an acute in vitro seizure model. KEY RESULTS CBD activity is partially dependent upon the mitochondrial glycine cleavage system component, GcvH1 in Dictyostelium, orthologous to the human glycine cleavage system component H protein, which is functionally linked to folate one-carbon metabolism (FOCM). Analysis of FOCM components identified a mechanism for CBD in directly inhibiting methionine synthesis. Analysis of brain tissue from a Dravet syndrome mouse model also showed drastically altered levels of one-carbon components including methionine, and an in vitro rat seizure model showed an elevated level of methionine that is attenuated following CBD treatment. CONCLUSIONS AND IMPLICATIONS Our results suggest a novel mechanism for CBD in the regulating methionine levels and identify altered one-carbon metabolism in Dravet syndrome and seizure activity.
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Affiliation(s)
- Christopher J. Perry
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Paul Finch
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | | | - Kit‐Yi Leung
- Development Biology and Cancer ProgramUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Eleanor C. Warren
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Joseph Damstra‐Oddy
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Devdutt Sharma
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Pabitra H. Patra
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Sarah Glyn
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Joanna Boberska
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Balint Stewart
- Faculty of Life SciencesManchester UniversityManchesterUK
| | - Amy Baldwin
- Neuroscience and Mental Health Research InstituteCardiff UniversityCardiffUK
| | - Fabiana Piscitelli
- Institute of Biomolecular ChemistryConsiglio Nazionale delle RicercheRomeItaly
| | - Robert J. Harvey
- School of Health and Sport SciencesUniversity of the Sunshine CoastSippy DownsQLDAustralia
- Sunshine Coast Health InstituteUniversity of the Sunshine CoastBirtinyaQLDAustralia
| | - Adrian Harwood
- Neuroscience and Mental Health Research InstituteCardiff UniversityCardiffUK
| | | | - Sandrine P. Claus
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Nicholas D.E. Greene
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Alister J. McNeish
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Claire M. Williams
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Benjamin J. Whalley
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Robin S.B. Williams
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
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Binder DK, Boison D, Eid T, Frankel WN, Mingorance A, Smith BN, Dacks PA, Whittemore V, Poduri A. Epilepsy Benchmarks Area II: Prevent Epilepsy and Its Progression. Epilepsy Curr 2020; 20:14S-22S. [PMID: 31937124 PMCID: PMC7031802 DOI: 10.1177/1535759719895274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Area II of the 2014 Epilepsy Research Benchmarks aims to establish goals for preventing the development and progression of epilepsy. In this review, we will highlight key advances in Area II since the last summary of research progress and opportunities was published in 2016. We also highlight areas of investigation that began to develop before 2016 and in which additional progress has been made more recently.
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Affiliation(s)
- Devin K Binder
- Division of Biomedical Sciences, School of Medicine, Center for Glial-Neuronal Interactions, University of California, Riverside, CA, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson and New Jersey Medical Schools, Rutgers University, Piscataway, NJ, USA
| | - Tore Eid
- Department of Laboratory Medicine, Neurosurgery and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Wayne N Frankel
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | | | - Bret N Smith
- Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, USA
| | | | - Vicky Whittemore
- Division of Neuroscience, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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Burrows DRW, Samarut É, Liu J, Baraban SC, Richardson MP, Meyer MP, Rosch RE. Imaging epilepsy in larval zebrafish. Eur J Paediatr Neurol 2020; 24:70-80. [PMID: 31982307 PMCID: PMC7035958 DOI: 10.1016/j.ejpn.2020.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 12/19/2022]
Abstract
Our understanding of the genetic aetiology of paediatric epilepsies has grown substantially over the last decade. However, in order to translate improved diagnostics to personalised treatments, there is an urgent need to link molecular pathophysiology in epilepsy to whole-brain dynamics in seizures. Zebrafish have emerged as a promising new animal model for epileptic seizure disorders, with particular relevance for genetic and developmental epilepsies. As a novel model organism for epilepsy research they combine key advantages: the small size of larval zebrafish allows high throughput in vivo experiments; the availability of advanced genetic tools allows targeted modification to model specific human genetic disorders (including genetic epilepsies) in a vertebrate system; and optical access to the entire central nervous system has provided the basis for advanced microscopy technologies to image structure and function in the intact larval zebrafish brain. There is a growing body of literature describing and characterising features of epileptic seizures and epilepsy in larval zebrafish. Recently genetically encoded calcium indicators have been used to investigate the neurobiological basis of these seizures with light microscopy. This approach offers a unique window into the multiscale dynamics of epileptic seizures, capturing both whole-brain dynamics and single-cell behaviour concurrently. At the same time, linking observations made using calcium imaging in the larval zebrafish brain back to an understanding of epileptic seizures largely derived from cortical electrophysiological recordings in human patients and mammalian animal models is non-trivial. In this review we briefly illustrate the state of the art of epilepsy research in zebrafish with particular focus on calcium imaging of epileptic seizures in the larval zebrafish. We illustrate the utility of a dynamic systems perspective on the epileptic brain for providing a principled approach to linking observations across species and identifying those features of brain dynamics that are most relevant to epilepsy. In the following section we survey the literature for imaging features associated with epilepsy and epileptic seizures and link these to observations made from humans and other more traditional animal models. We conclude by identifying the key challenges still facing epilepsy research in the larval zebrafish and indicate strategies for future research to address these and integrate more directly with the themes and questions that emerge from investigating epilepsy in other model systems and human patients.
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Affiliation(s)
- D R W Burrows
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - É Samarut
- Department of Neurosciences, Research Center of the University of Montreal Hospital Center, Montreal, Quebec, Canada
| | - J Liu
- Department of Neurological Surgery and Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - S C Baraban
- Department of Neurological Surgery and Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - M P Richardson
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - M P Meyer
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - R E Rosch
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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34
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Brenet A, Hassan-Abdi R, Somkhit J, Yanicostas C, Soussi-Yanicostas N. Defective Excitatory/Inhibitory Synaptic Balance and Increased Neuron Apoptosis in a Zebrafish Model of Dravet Syndrome. Cells 2019; 8:cells8101199. [PMID: 31590334 PMCID: PMC6829503 DOI: 10.3390/cells8101199] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/04/2019] [Accepted: 10/03/2019] [Indexed: 12/22/2022] Open
Abstract
Dravet syndrome is a type of severe childhood epilepsy that responds poorly to current anti-epileptic drugs. In recent years, zebrafish disease models with Scn1Lab sodium channel deficiency have been generated to seek novel anti-epileptic drug candidates, some of which are currently undergoing clinical trials. However, the spectrum of neuronal deficits observed following Scn1Lab depletion in zebrafish larvae has not yet been fully explored. To fill this gap and gain a better understanding of the mechanisms underlying neuron hyperexcitation in Scn1Lab-depleted larvae, we analyzed neuron activity in vivo using combined local field potential recording and transient calcium uptake imaging, studied the distribution of excitatory and inhibitory synapses and neurons as well as investigated neuron apoptosis. We found that Scn1Lab-depleted larvae displayed recurrent epileptiform seizure events, associating massive synchronous calcium uptakes and ictal-like local field potential bursts. Scn1Lab-depletion also caused a dramatic shift in the neuronal and synaptic balance toward excitation and increased neuronal death. Our results thus provide in vivo evidence suggesting that Scn1Lab loss of function causes neuron hyperexcitation as the result of disturbed synaptic balance and increased neuronal apoptosis.
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Affiliation(s)
- Alexandre Brenet
- Université de Paris, NeuroDiderot, Inserm, F-75019 Paris, France.
| | | | - Julie Somkhit
- Université de Paris, NeuroDiderot, Inserm, F-75019 Paris, France.
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35
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Chan F, Lax NZ, Voss CM, Aldana BI, Whyte S, Jenkins A, Nicholson C, Nichols S, Tilley E, Powell Z, Waagepetersen HS, Davies CH, Turnbull DM, Cunningham MO. The role of astrocytes in seizure generation: insights from a novel in vitro seizure model based on mitochondrial dysfunction. Brain 2019; 142:391-411. [PMID: 30689758 DOI: 10.1093/brain/awy320] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022] Open
Abstract
Approximately one-quarter of patients with mitochondrial disease experience epilepsy. Their epilepsy is often severe and resistant towards conventional antiepileptic drugs. Despite the severity of this epilepsy, there are currently no animal models available to provide a mechanistic understanding of mitochondrial epilepsy. We conducted neuropathological studies on patients with mitochondrial epilepsy and found the involvement of the astrocytic compartment. As a proof of concept, we developed a novel brain slice model of mitochondrial epilepsy by the application of an astrocytic-specific aconitase inhibitor, fluorocitrate, concomitant with mitochondrial respiratory inhibitors, rotenone and potassium cyanide. The model was robust and exhibited both face and predictive validity. We then used the model to assess the role that astrocytes play in seizure generation and demonstrated the involvement of the GABA-glutamate-glutamine cycle. Notably, glutamine appears to be an important intermediary molecule between the neuronal and astrocytic compartment in the regulation of GABAergic inhibitory tone. Finally, we found that a deficiency in glutamine synthetase is an important pathogenic process for seizure generation in both the brain slice model and the human neuropathological study. Our study describes the first model for mitochondrial epilepsy and provides a mechanistic insight into how astrocytes drive seizure generation in mitochondrial epilepsy.
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Affiliation(s)
- Felix Chan
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK.,Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Caroline Marie Voss
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Blanca Irene Aldana
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Shuna Whyte
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Alistair Jenkins
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Claire Nicholson
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Sophie Nichols
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Elizabeth Tilley
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Zoe Powell
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Ceri H Davies
- Neural Pathways DPU, GSK, 11 Biopolis Way, Singapore
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Mark O Cunningham
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK.,Discipline of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
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36
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Fichi G, Naef V, Barca A, Longo G, Fronte B, Verri T, Santorelli FM, Marchese M, Petruzzella V. Fishing in the Cell Powerhouse: Zebrafish as A Tool for Exploration of Mitochondrial Defects Affecting the Nervous System. Int J Mol Sci 2019; 20:ijms20102409. [PMID: 31096646 PMCID: PMC6567007 DOI: 10.3390/ijms20102409] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/30/2022] Open
Abstract
The zebrafish (Danio rerio) is a small vertebrate ideally suited to the modeling of human diseases. Large numbers of genetic alterations have now been modeled and could be used to study organ development by means of a genetic approach. To date, limited attention has been paid to the possible use of the zebrafish toolbox in studying human mitochondrial disorders affecting the nervous system. Here, we review the pertinent scientific literature discussing the use of zebrafish in modeling gene mutations involved in mitochondria-related neurological human diseases. A critical analysis of the literature suggests that the zebrafish not only lends itself to exploration of the pathological consequences of mitochondrial energy output on the nervous system but could also serve as an attractive platform for future drugs in an as yet untreatable category of human disorders.
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Affiliation(s)
- Gianluca Fichi
- Molecular Medicine, IRCCS Stella Maris, Via dei Giacinti 2, 56028 Pisa, Italy.
| | - Valentina Naef
- Molecular Medicine, IRCCS Stella Maris, Via dei Giacinti 2, 56028 Pisa, Italy.
| | - Amilcare Barca
- Laboratory of General Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.
| | - Giovanna Longo
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari 'Aldo Moro', Piazza Giulio Cesare 11, 70124 Bari, Italy.
| | - Baldassare Fronte
- Department of Veterinary Sciences, University of Pisa, viale delle Piagge 2, 56124 Pisa, Italy.
| | - Tiziano Verri
- Laboratory of General Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.
| | | | - Maria Marchese
- Molecular Medicine, IRCCS Stella Maris, Via dei Giacinti 2, 56028 Pisa, Italy.
| | - Vittoria Petruzzella
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari 'Aldo Moro', Piazza Giulio Cesare 11, 70124 Bari, Italy.
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37
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Network Properties Revealed during Multi-Scale Calcium Imaging of Seizure Activity in Zebrafish. eNeuro 2019; 6:eN-NWR-0041-19. [PMID: 30895220 PMCID: PMC6424556 DOI: 10.1523/eneuro.0041-19.2019] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 02/08/2019] [Indexed: 12/02/2022] Open
Abstract
Seizures are characterized by hypersynchronization of neuronal networks. Understanding these networks could provide a critical window for therapeutic control of recurrent seizure activity, i.e., epilepsy. However, imaging seizure networks has largely been limited to microcircuits in vitro or small “windows” in vivo. Here, we combine fast confocal imaging of genetically encoded calcium indicator (GCaMP)-expressing larval zebrafish with local field potential (LFP) recordings to study epileptiform events at whole-brain and single-neuron levels in vivo. Using an acute seizure model (pentylenetetrazole, PTZ), we reliably observed recurrent electrographic ictal-like events associated with generalized activation of all major brain regions and uncovered a well-preserved anterior-to-posterior seizure propagation pattern. We also examined brain-wide network synchronization and spatiotemporal patterns of neuronal activity in the optic tectum microcircuit. Brain-wide and single-neuronal level analysis of PTZ-exposed and 4-aminopyridine (4-AP)-exposed zebrafish revealed distinct network dynamics associated with seizure and non-seizure hyperexcitable states, respectively. Neuronal ensembles, comprised of coactive neurons, were also uncovered during interictal-like periods. Taken together, these results demonstrate that macro- and micro-network calcium motifs in zebrafish may provide a greater understanding of epilepsy.
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38
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Li Z, Li W, Zha J, Chen H, Martyniuk CJ, Liang X. Transcriptome analysis reveals benzotriazole ultraviolet stabilizers regulate networks related to inflammation in juvenile zebrafish (Danio rerio) brain. ENVIRONMENTAL TOXICOLOGY 2019; 34:112-122. [PMID: 30315675 DOI: 10.1002/tox.22663] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 09/22/2018] [Accepted: 09/23/2018] [Indexed: 06/08/2023]
Abstract
Benzotriazole ultraviolet stabilizers (BUVSs) are widely applied ultraviolet absorbing compounds in industrial materials and personal care products. Due to their ubiquitous use and reports of bio-accumulation in aquatic organisms, these compounds are significant environmental pollutants; however, data are limited for BUVSs toxicity. In this study, juvenile zebrafish (Danio rerio) were exposed to 4 commonly used BUVSs (UV-234, UV-326, UV-329, and UV-P) at one dose of 10 or 100 μg/L for 28 days. To characterize the underlying mechanisms of different BUVSs-induced toxicities, we performed global transcriptome sequencing (RNA-Seq) in the brain (100 μg/L). There were 390, 575, 483, and 470 differentially expressed genes (DEGs) detected following UV-234, UV-326, UV-329, and UV-P exposure at 100 μg/L, respectively. Only 59 genes were identified as DEGs following exposure to each of the BUVSs, suggesting that these chemicals can induce unique responses in fish. Noteworthy was that there were 81 common gene networks (~10%) identified following exposure to BUVSs, many of which were related to inflammation and immune function. Uniquely regulated pathways affected by different BUVSs included those related to mitochondrial respiration, interleukin 1/brain-damaging signaling, dopaminergic signaling, and adrenergic receptor cascades. Furthermore, quantitative PCR (qPCR) results revealed that mgst1 levels were increased in fish from the 100 μg/L UV-329 treatment, while the expression of pck2 was significantly down-regulated in fish from both the 10 and 100 μg/L UV-P treatment. Transcriptomic data suggest that BUVSs can alter mitochondrial bioenergetics, alter expression of a broad range of genes in the oxidative stress response, and can induce pathways related to the immune system in zebrafish brain.
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Affiliation(s)
- Zhitong Li
- Inner Mongolia Key Laboratory of Environmental Pollution Control & Waste Resource Reuse, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Wenjing Li
- Inner Mongolia Key Laboratory of Environmental Pollution Control & Waste Resource Reuse, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Jinmiao Zha
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Huihui Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Xuefang Liang
- Inner Mongolia Key Laboratory of Environmental Pollution Control & Waste Resource Reuse, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
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39
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Shi X, He W, Guo S, Zhang B, Ren S, Liu K, Sun T, Cui J. RNA-seq Analysis of the SCN1A-KO Model based on CRISPR/Cas9 Genome Editing Technology. Neuroscience 2018; 398:1-11. [PMID: 30529264 DOI: 10.1016/j.neuroscience.2018.11.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/30/2018] [Accepted: 11/30/2018] [Indexed: 01/14/2023]
Abstract
Dravet syndrome (DS) is a disease that is primarily caused by the inactivation of the SCN1A-encoded voltage-gated sodium channel alpha subunit (Nav1.1). In this study, we constructed an SCN1A gene knockout model using CRISPR/Cas9 genome editing technology to deprive the Nav1.1 function in vitro. With mRNA-seq analysis we found abundant gene changes after SCN1A knockout, which associated with various signaling pathways, such as cancer pathways, the PI3K-AKT signaling pathway, the MAPK signaling pathway, and pathways involved in HTLV-I infection. We also noticed changes in the spliceosome, decreased glycolytic capacity, disturbances in calcium signaling pathways, and changes in the potassium, sodium, chloride, and calcium plasma channels after SCN1A knockout. In this study, we have been the first time to discover these changes and summarize them here and hope it would provide some clue for the study of Nav1.1 in the nervous system.
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Affiliation(s)
- Xiaoguang Shi
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Wenxin He
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Shanshan Guo
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Bingying Zhang
- Department of Biochemistry and Molecular Biology, The School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
| | - Shuanglai Ren
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Kunmei Liu
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Tao Sun
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Jianqi Cui
- The Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, Yinchuan, China; Department of Biochemistry and Molecular Biology, The School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China.
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40
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From molecules to medicines: the dawn of targeted therapies for genetic epilepsies. Nat Rev Neurol 2018; 14:735-745. [DOI: 10.1038/s41582-018-0099-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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41
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Abstract
There is a resurgence of interest in the role of metabolism in epilepsy. Long considered ancillary and acknowledged only in the context of clinical application of ketogenic diets, metabolic control of epilepsy is gaining momentum and mainstream interest among researchers. A metabolic paradigm for epilepsy rests upon known perturbations in three major interconnected metabolic nodes and therapeutic targets therefrom (i.e., glycolysis, mitochondria, and redox balance).
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42
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Bolser DG, Dreier DA, Li E, Kroll KJ, Martyniuk CJ, Denslow ND. Toward an adverse outcome pathway for impaired growth: Mitochondrial dysfunction impairs growth in early life stages of the fathead minnow (Pimephales promelas). Comp Biochem Physiol C Toxicol Pharmacol 2018; 209:46-53. [PMID: 29625345 DOI: 10.1016/j.cbpc.2018.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/08/2018] [Accepted: 03/28/2018] [Indexed: 01/19/2023]
Abstract
Chemical contaminants present in the environment can affect mitochondrial bioenergetics in aquatic organisms and can have substantial effects on individual fitness. As early life stages of fish are particularly vulnerable to environmental contaminants, they are ideal models for examining the relationship between impaired mitochondrial bioenergetics (ATP-dependent respiration, basal oxidative respiration) and apical endpoints such as growth. Here, early life stages of the fathead minnow (Pimephales promelas), an ecologically relevant North American species, were used to investigate the relationship between mitochondrial bioenergetics and growth following perturbation with model mitochondrial toxicants 2,4-dinitrophenol and octylamine. Fathead minnows were exposed to 2,4-dinitrophenol and octylamine at 3 concentrations for 24 h and endpoints related to mitochondrial bioenergetics were measured with the Agilent Seahorse XFe24 Bioanalyzer. In order to link changes in mitochondrial bioenergetics to growth, fathead minnows were exposed to the same chemical contaminants for 7-14 days and growth was measured by measuring total length on a weekly basis. There was a significant correlation between decrease in average length at 14 days and basal respiration (r = 0.997, p = 0.050, n = 3), as well as maximal respiration (r = 0.998, p-value = 0.043, n = 3) for embryos exposed to 2,4 dinitrophenol. For octylamine, ATP production was highly correlated with average length at 7 days (p-value = 0.1) and spare respiratory capacity and average length at 14 days were highly correlated (p-value = 0.1). These data improve understanding of how mitochondrial toxicants impair growth in fish larvae and may be useful for developing an adverse outcome pathway for growth.
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Affiliation(s)
- Derek G Bolser
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - David A Dreier
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Erchao Li
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China
| | - Kevin J Kroll
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Nancy D Denslow
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
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Griffin A, Hamling KR, Hong S, Anvar M, Lee LP, Baraban SC. Preclinical Animal Models for Dravet Syndrome: Seizure Phenotypes, Comorbidities and Drug Screening. Front Pharmacol 2018; 9:573. [PMID: 29915537 PMCID: PMC5994396 DOI: 10.3389/fphar.2018.00573] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/14/2018] [Indexed: 12/18/2022] Open
Abstract
Epilepsy is a common chronic neurological disease affecting almost 3 million people in the United States and 50 million people worldwide. Despite availability of more than two dozen FDA-approved anti-epileptic drugs (AEDs), one-third of patients fail to receive adequate seizure control. Specifically, pediatric genetic epilepsies are often the most severe, debilitating and pharmaco-resistant forms of epilepsy. Epileptic syndromes share a common symptom of unprovoked seizures. While some epilepsies/forms of epilepsy are the result of acquired insults such as head trauma, febrile seizure, or viral infection, others have a genetic basis. The discovery of epilepsy associated genes suggests varied underlying pathologies and opens the door for development of new "personalized" treatment options for each genetic epilepsy. Among these, Dravet syndrome (DS) has received substantial attention for both the pre-clinical and early clinical development of novel therapeutics. Despite these advances, there is no FDA-approved treatment for DS. Over 80% of patients diagnosed with DS carry a de novo mutation within the voltage-gated sodium channel gene SCN1A and these patients suffer with drug resistant and life-threatening seizures. Here we will review the preclinical animal models for DS featuring inactivation of SCN1A (including zebrafish and mice) with an emphasis on seizure phenotypes and behavioral comorbidities. Because many drugs fail somewhere between initial preclinical discovery and clinical trials, it is equally important that we understand how these models respond to known AEDs. As such, we will also review the available literature and recent drug screening efforts using these models with a focus on assay protocols and predictive pharmacological profiles. Validation of these preclinical models is a critical step in our efforts to efficiently discover new therapies for these patients. The behavioral and electrophysiological drug screening assays in zebrafish will be discussed in detail including specific examples from our laboratory using a zebrafish scn1 mutant and a summary of the nearly 3000 drugs screened to date. As the discovery and development phase rapidly moves from the lab-to-the-clinic for DS, it is hoped that this preclinical strategy offers a platform for how to approach any genetic epilepsy.
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Affiliation(s)
- Aliesha Griffin
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Kyla R Hamling
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - SoonGweon Hong
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Mana Anvar
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Luke P Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Scott C Baraban
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
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Abstract
PURPOSE OF REVIEW High-fat, low-carbohydrate ketogenic diets have been used for almost a century for the treatment of epilepsy. Used traditionally for the treatment of refractory pediatric epilepsies, in recent years the use of ketogenic diets has experienced a revival to include the treatment of adulthood epilepsies as well as conditions ranging from autism to chronic pain and cancer. Despite the ability of ketogenic diet therapy to suppress seizures refractory to antiepileptic drugs and reports of lasting seizure freedom, the underlying mechanisms are poorly understood. This review explores new insights into mechanisms mobilized by ketogenic diet therapies. RECENT FINDINGS Ketogenic diets act through a combination of mechanisms, which are linked to the effects of ketones and glucose restriction, and to interactions with receptors, channels, and metabolic enzymes. Decanoic acid, a component of medium-chain triclycerides, contributes to seizure control through direct α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor inhibition, whereas drugs targeting lactate dehydrogenase reduce seizures through inhibition of a metabolic pathway. Ketogenic diet therapy also affects DNA methylation, a novel epigenetic mechanism of the diet. SUMMARY Ketogenic diet therapy combines several beneficial mechanisms that provide broad benefits for the treatment of epilepsy with the potential to not only suppress seizures but also to modify the course of the epilepsy.
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Dolce A, Santos P, Chen W, Hoke A, Hartman AL. Different ketogenesis strategies lead to disparate seizure outcomes. Epilepsy Res 2018; 143:90-97. [PMID: 29723773 DOI: 10.1016/j.eplepsyres.2018.04.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/28/2018] [Accepted: 04/25/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Despite the introduction of new medicines to treat epilepsy over the last 50 years, the number of patients with poorly-controlled seizures remains unchanged. Metabolism-based therapies are an underutilized treatment option for this population. We hypothesized that two different means of systemic ketosis, the ketogenic diet and intermittent fasting, would differ in their acute seizure test profiles and mitochondrial respiration. METHODS Male NIH Swiss mice (aged 3-4 weeks) were fed for 12-13 days using one of four diet regimens: ketogenic diet (KD), control diet matched to KD for protein content and micronutrients (CD), or CD with intermittent fasting (24 h feed/24 h fast) (CD-IF), tested post-feed or post-fast. Mice were subject to the 6 Hz threshold test or, in separate cohorts, after injection of kainic acid in doses based on their weight (Cohort I) or a uniform dose regardless of weight (Cohort II). Mitochondrial respiration was tested in brain tissue isolated from similarly-fed seizure-naïve mice. RESULTS KD mice were protected against 6 Hz-induced seizures but had more severe seizure scores in the kainic acid test (Cohorts I & II), the opposite of CD-IF mice. No differences were noted in mitochondrial respiration between diet regimens. INTERPRETATION KD and CD-IF do not share identical antiseizure mechanisms. These differences were not explained by differences in mitochondrial respiration. Nevertheless, both KD and CD-IF regimens protected against different types of seizures, suggesting that mechanisms underlying CD-IF seizure protection should be explored further.
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Affiliation(s)
- Alison Dolce
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA; Departments of Pediatrics, Neurology & Neurotherapeutics, University of Texas Southwestern, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
| | - Polan Santos
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
| | - Weiran Chen
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
| | - Ahmet Hoke
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA.
| | - Adam L Hartman
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA.
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Kovac S, Preza E, Houlden H, Walker MC, Abramov AY. Impaired Bioenergetics in Mutant Mitochondrial DNA Determines Cell Fate During Seizure-Like Activity. Mol Neurobiol 2018; 56:321-334. [PMID: 29704197 DOI: 10.1007/s12035-018-1078-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 04/10/2018] [Indexed: 11/26/2022]
Abstract
Mutations in genes affecting mitochondrial proteins are increasingly recognised in patients with epilepsy, but the factors determining cell fate during seizure activity in these mutations remain unknown. Fluorescent dye imaging techniques were applied to fibroblast cell lines from patients suffering from common mitochondrial mutations and to age-matched controls. Using live cell imaging techniques in fibroblasts, we show that fibroblasts with mutations in the mitochondrial genome had reduced mitochondrial membrane potential and NADH pools and higher redox indices, indicative of respiratory chain dysfunction. Increasing concentrations of ferutinin, a Ca2+ ionophore, led to oscillatory Ca2+ signals in fibroblasts resembling dynamic Ca2+ changes that occur during seizure-like activity. Co-monitoring of mitochondrial membrane potential (ΔΨm) changes induced by ferutinin showed accelerated membrane depolarisation and cell collapse in fibroblasts with mutations in the mitochondrial genome when compared to controls. Ca2+ flash photolysis using caged Ca2+ confirmed impaired Ca2+ handling in fibroblasts with mitochondrial mutations. Findings indicate that intracellular Ca2+ levels cannot be compensated during periods of hyperexcitability, leading to Ca2+ overload and subsequent cell death in mitochondrial diseases.
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Affiliation(s)
- Stjepana Kovac
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK.
- Department of Neurology, University of Muenster, Muenster, Germany.
| | | | - Henry Houlden
- Department of Molecular Neuroscience, UCL, London, UK
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
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Ibhazehiebo K, Gavrilovici C, de la Hoz CL, Ma SC, Rehak R, Kaushik G, Meza Santoscoy PL, Scott L, Nath N, Kim DY, Rho JM, Kurrasch DM. A novel metabolism-based phenotypic drug discovery platform in zebrafish uncovers HDACs 1 and 3 as a potential combined anti-seizure drug target. Brain 2018; 141:744-761. [PMID: 29373639 PMCID: PMC5837409 DOI: 10.1093/brain/awx364] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 10/29/2017] [Accepted: 11/05/2017] [Indexed: 01/01/2023] Open
Abstract
Despite the development of newer anti-seizure medications over the past 50 years, 30-40% of patients with epilepsy remain refractory to treatment. One explanation for this lack of progress is that the current screening process is largely biased towards transmembrane channels and receptors, and ignores intracellular proteins and enzymes that might serve as efficacious molecular targets. Here, we report the development of a novel drug screening platform that harnesses the power of zebrafish genetics and combines it with in vivo bioenergetics screening assays to uncover therapeutic agents that improve mitochondrial health in diseased animals. By screening commercially available chemical libraries of approved drugs, for which the molecular targets and pathways are well characterized, we were able to reverse-identify the proteins targeted by efficacious compounds and confirm the physiological roles that they play by utilizing other pharmacological ligands. Indeed, using an 870-compound screen in kcna1-morpholino epileptic zebrafish larvae, we uncovered vorinostat (Zolinza™; suberanilohydroxamic acid, SAHA) as a potent anti-seizure agent. We further demonstrated that vorinostat decreased average daily seizures by ∼60% in epileptic Kcna1-null mice using video-EEG recordings. Given that vorinostat is a broad histone deacetylase (HDAC) inhibitor, we then delineated a specific subset of HDACs, namely HDACs 1 and 3, as potential drug targets for future screening. In summary, we have developed a novel phenotypic, metabolism-based experimental therapeutics platform that can be used to identify new molecular targets for future drug discovery in epilepsy.
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Affiliation(s)
- Kingsley Ibhazehiebo
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Cezar Gavrilovici
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
- Departments of Pediatrics, Clinical Neurosciences, Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Cristiane L de la Hoz
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Shun-Chieh Ma
- Departments of Neurology and Neurobiology, Barrow Neurological Institute, St Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Renata Rehak
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Gaurav Kaushik
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Paola L Meza Santoscoy
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Lucas Scott
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
- Departments of Pediatrics, Clinical Neurosciences, Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Nandan Nath
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
| | - Do-Young Kim
- Departments of Neurology and Neurobiology, Barrow Neurological Institute, St Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Jong M Rho
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
- Departments of Pediatrics, Clinical Neurosciences, Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Deborah M Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Canada
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Pearson-Smith JN, Patel M. Metabolic Dysfunction and Oxidative Stress in Epilepsy. Int J Mol Sci 2017; 18:ijms18112365. [PMID: 29117123 PMCID: PMC5713334 DOI: 10.3390/ijms18112365] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 01/17/2023] Open
Abstract
The epilepsies are a heterogeneous group of disorders characterized by the propensity to experience spontaneous recurrent seizures. Epilepsies can be genetic or acquired, and the underlying mechanisms of seizure initiation, seizure propagation, and comorbid conditions are incompletely understood. Metabolic changes including the production of reactive species are known to result from prolonged seizures and may also contribute to epilepsy development. In this review, we focus on the evidence that metabolic and redox disruption is both cause and consequence of epileptic seizures. Additionally, we discuss the promise of targeting redox processes as a therapeutic option in epilepsy.
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Affiliation(s)
- Jennifer N Pearson-Smith
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
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Behavioral Comorbidities and Drug Treatments in a Zebrafish scn1lab Model of Dravet Syndrome. eNeuro 2017; 4:eN-NWR-0066-17. [PMID: 28812061 PMCID: PMC5555352 DOI: 10.1523/eneuro.0066-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 07/11/2017] [Accepted: 07/30/2017] [Indexed: 12/15/2022] Open
Abstract
Loss-of-function mutations in SCN1A cause Dravet syndrome (DS), a catastrophic childhood epilepsy in which patients experience comorbid behavioral conditions, including movement disorders, sleep abnormalities, anxiety, and intellectual disability. To study the functional consequences of voltage-gated sodium channel mutations, we use zebrafish with a loss-of-function mutation in scn1lab, a zebrafish homolog of human SCN1A. Homozygous scn1labs552/s552 mutants exhibit early-life seizures, metabolic deficits, and early death. Here, we developed in vivo assays using scn1labs552 mutants between 3 and 6 d postfertilization (dpf). To evaluate sleep disturbances, we monitored larvae for 24 h with locomotion tracking software. Locomotor activity during dark (night phase) was significantly higher in mutants than in controls. Among anticonvulsant drugs, clemizole and diazepam, but not trazodone or valproic acid, decreased distance moved at night for scn1labs552 mutant larvae. To monitor exploratory behavior in an open field, we tracked larvae in a novel arena. Mutant larvae exhibited impaired exploratory behavior, with increased time spent near the edge of the arena and decreased mobility, suggesting greater anxiety. Both clemizole and diazepam, but not trazodone or valproic acid, decreased distance moved and increased time spent in the center of the arena. Counting inhibitory neurons in vivo revealed no differences between scn1labs552 mutants and siblings. Taken together, our results demonstrate conserved features of sleep, anxiety, and movement disorders in scn1lab mutant zebrafish, and provide evidence that a zebrafish model allows effective tests of treatments for behavioral comorbidities associated with DS.
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Griffin A, Hamling KR, Knupp K, Hong S, Lee LP, Baraban SC. Clemizole and modulators of serotonin signalling suppress seizures in Dravet syndrome. Brain 2017; 140:669-683. [PMID: 28073790 DOI: 10.1093/brain/aww342] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/18/2016] [Indexed: 01/01/2023] Open
Abstract
Dravet syndrome is a catastrophic childhood epilepsy with early-onset seizures, delayed language and motor development, sleep disturbances, anxiety-like behaviour, severe cognitive deficit and an increased risk of fatality. It is primarily caused by de novo mutations of the SCN1A gene encoding a neuronal voltage-activated sodium channel. Zebrafish with a mutation in the SCN1A homologue recapitulate spontaneous seizure activity and mimic the convulsive behavioural movements observed in Dravet syndrome. Here, we show that phenotypic screening of drug libraries in zebrafish scn1 mutants rapidly and successfully identifies new therapeutics. We demonstrate that clemizole binds to serotonin receptors and its antiepileptic activity can be mimicked by drugs acting on serotonin signalling pathways e.g. trazodone and lorcaserin. Coincident with these zebrafish findings, we treated five medically intractable Dravet syndrome patients with a clinically-approved serotonin receptor agonist (lorcaserin, Belviq®) and observed some promising results in terms of reductions in seizure frequency and/or severity. Our findings demonstrate a rapid path from preclinical discovery in zebrafish, through target identification, to potential clinical treatments for Dravet syndrome.
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Affiliation(s)
- Aliesha Griffin
- Epilepsy Research Laboratory and Weill Institute for Neurosciences, Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Kyla R Hamling
- Epilepsy Research Laboratory and Weill Institute for Neurosciences, Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Kelly Knupp
- Department of Pediatrics, University of Colorado Denver, Denver, CO, USA
| | - SoonGweon Hong
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Program, University of California, Berkeley, Berkeley, CA, USA
| | - Luke P Lee
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Program, University of California, Berkeley, Berkeley, CA, USA
| | - Scott C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neurosciences, Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
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