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Schuster J, Lu X, Dang Y, Klar J, Wenz A, Dahl N, Chen X. Epigenetic insights into GABAergic development in Dravet Syndrome iPSC and therapeutic implications. eLife 2024; 12:RP92599. [PMID: 39190448 PMCID: PMC11349296 DOI: 10.7554/elife.92599] [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] [Indexed: 08/28/2024] Open
Abstract
Dravet syndrome (DS) is a devastating early-onset refractory epilepsy syndrome caused by variants in the SCN1A gene. A disturbed GABAergic interneuron function is implicated in the progression to DS but the underlying developmental and pathophysiological mechanisms remain elusive, in particularly at the chromatin level. Induced pluripotent stem cells (iPSCs) derived from DS cases and healthy donors were used to model disease-associated epigenetic abnormalities of GABAergic development. Chromatin accessibility was assessed at multiple time points (Day 0, Day 19, Day 35, and Day 65) of GABAergic differentiation. Additionally, the effects of the commonly used anti-seizure drug valproic acid (VPA) on chromatin accessibility were elucidated in GABAergic cells. The distinct dynamics in the chromatin profile of DS iPSC predicted accelerated early GABAergic development, evident at D19, and diverged further from the pattern in control iPSC with continued differentiation, indicating a disrupted GABAergic maturation. Exposure to VPA at D65 reshaped the chromatin landscape at a variable extent in different iPSC-lines and rescued the observed dysfunctional development of some DS iPSC-GABA. The comprehensive investigation on the chromatin landscape of GABAergic differentiation in DS-patient iPSC offers valuable insights into the epigenetic dysregulations associated with interneuronal dysfunction in DS. Moreover, the detailed analysis of the chromatin changes induced by VPA in iPSC-GABA holds the potential to improve the development of personalized and targeted anti-epileptic therapies.
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Affiliation(s)
- Jens Schuster
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Xi Lu
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Yonglong Dang
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Joakim Klar
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Amelie Wenz
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Niklas Dahl
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
| | - Xingqi Chen
- Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life LaboratoryUppsalaSweden
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Pereira MF, Shyti R, Testa G. In and out: Benchmarking in vitro, in vivo, ex vivo, and xenografting approaches for an integrative brain disease modeling pipeline. Stem Cell Reports 2024; 19:767-795. [PMID: 38865969 DOI: 10.1016/j.stemcr.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 06/14/2024] Open
Abstract
Human cellular models and their neuronal derivatives have afforded unprecedented advances in elucidating pathogenic mechanisms of neuropsychiatric diseases. Notwithstanding their indispensable contribution, animal models remain the benchmark in neurobiological research. In an attempt to harness the best of both worlds, researchers have increasingly relied on human/animal chimeras by xenografting human cells into the animal brain. Despite the unparalleled potential of xenografting approaches in the study of the human brain, literature resources that systematically examine their significance and advantages are surprisingly lacking. We fill this gap by providing a comprehensive account of brain diseases that were thus far subjected to all three modeling approaches (transgenic rodents, in vitro human lineages, human-animal xenografting) and provide a critical appraisal of the impact of xenografting approaches for advancing our understanding of those diseases and brain development. Next, we give our perspective on integrating xenografting modeling pipeline with recent cutting-edge technological advancements.
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Affiliation(s)
- Marlene F Pereira
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139 Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122 Milan, Italy; Neurogenomics Centre, Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
| | - Reinald Shyti
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139 Milan, Italy; Neurogenomics Centre, Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
| | - Giuseppe Testa
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139 Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122 Milan, Italy; Neurogenomics Centre, Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
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Brown JA, Faley SL, Judge M, Ward P, Ihrie RA, Carson R, Armstrong L, Sahin M, Wikswo JP, Ess KC, Neely MD. Rescue of impaired blood-brain barrier in tuberous sclerosis complex patient derived neurovascular unit. J Neurodev Disord 2024; 16:27. [PMID: 38783199 PMCID: PMC11112784 DOI: 10.1186/s11689-024-09543-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is a multi-system genetic disease that causes benign tumors in the brain and other vital organs. The most debilitating symptoms result from involvement of the central nervous system and lead to a multitude of severe symptoms including seizures, intellectual disability, autism, and behavioral problems. TSC is caused by heterozygous mutations of either the TSC1 or TSC2 gene and dysregulation of mTOR kinase with its multifaceted downstream signaling alterations is central to disease pathogenesis. Although the neurological sequelae of the disease are well established, little is known about how these mutations might affect cellular components and the function of the blood-brain barrier (BBB). METHODS We generated TSC disease-specific cell models of the BBB by leveraging human induced pluripotent stem cell and microfluidic cell culture technologies. RESULTS Using microphysiological systems, we demonstrate that a BBB generated from TSC2 heterozygous mutant cells shows increased permeability. This can be rescued by wild type astrocytes or by treatment with rapamycin, an mTOR kinase inhibitor. CONCLUSION Our results demonstrate the utility of microphysiological systems to study human neurological disorders and advance our knowledge of cell lineages contributing to TSC pathogenesis and informs future therapeutics.
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Affiliation(s)
- Jacquelyn A Brown
- Department of Physics and Astronomy, Vanderbilt University, Nashville, USA
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, USA
| | - Shannon L Faley
- Department of Physics and Astronomy, Vanderbilt University, Nashville, USA
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, USA
| | - Monika Judge
- Department of Physics and Astronomy, Vanderbilt University, Nashville, USA
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, USA
| | - Patricia Ward
- Department of Physics and Astronomy, Vanderbilt University, Nashville, USA
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, USA
| | - Rebecca A Ihrie
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, USA
- Neurological Surgery, Vanderbilt University Medical Center, Nashville, USA
| | - Robert Carson
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, USA
| | - Laura Armstrong
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, USA
| | - Mustafa Sahin
- Rosamund Stone Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, USA
| | - John P Wikswo
- Department of Physics and Astronomy, Vanderbilt University, Nashville, USA
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, USA
| | - Kevin C Ess
- Neurological Surgery, Vanderbilt University Medical Center, Nashville, USA.
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, USA.
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, USA.
| | - M Diana Neely
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, USA.
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4
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Mabry SA, Pavon N. Exploring the prospects, advancements, and challenges of in vitro modeling of the heart-brain axis. Front Cell Neurosci 2024; 18:1386355. [PMID: 38766369 PMCID: PMC11099243 DOI: 10.3389/fncel.2024.1386355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/12/2024] [Indexed: 05/22/2024] Open
Abstract
Research on bidirectional communication between the heart and brain has often relied on studies involving nonhuman animals. Dependance on animal models offer limited applicability to humans and a lack of high-throughput screening. Recently, the field of 3D cell biology, specifically organoid technology, has rapidly emerged as a valuable tool for studying interactions across organ systems, i.e., gut-brain axis. The initial success of organoid models indicates the usefulness of 3D cultures for elucidating the intricate interactivity of the autonomic nervous system and overall health. This perspective aims to explore the potential of advancing in vitro modeling of the heart-brain axis by discussing the benefits, applications, and adaptability of organoid technologies. We closely examine the current state of brain organoids in conjunction with the advancements of cardiac organoids. Moreover, we explore the use of combined organoid systems to investigate pathophysiology and provide a platform for treatment discovery. Finally, we address the challenges that accompany the use of 3D models for studying the heart-brain axis with an emphasis on generating tailored engineering strategies for further refinement of dynamic organ system modeling in vitro.
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Affiliation(s)
- Senegal Alfred Mabry
- Affect and Cognition Laboratory, Department of Psychology and Human Development, College of Human Ecology, Cornell University, Ithaca, NY, United States
| | - Narciso Pavon
- ChangHui Pak Laboratory, Department of Biochemistry and Molecular Biology, College of Natural Sciences, University of Massachusetts-Amherst, Amherst, MA, United States
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5
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Chi W, Kiskinis E. Integrative analysis of epilepsy-associated genes reveals expression-phenotype correlations. Sci Rep 2024; 14:3587. [PMID: 38351047 PMCID: PMC10864290 DOI: 10.1038/s41598-024-53494-2] [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: 07/28/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024] Open
Abstract
Epilepsy is a highly prevalent neurological disorder characterized by recurrent seizures. Patients exhibit broad genetic, molecular, and clinical diversity involving mild to severe comorbidities. The factors that contribute to this phenotypic diversity remain unclear. Here we used publicly available datasets to systematically interrogate the expression pattern of 230 epilepsy-associated genes across human tissues, developmental stages, and central nervous system (CNS) cellular subtypes. We grouped genes based on their curated phenotypes into 3 broad classes: core epilepsy genes (CEG), where seizures are the dominant phenotype, developmental and epileptic encephalopathy genes (DEEG) that are associated with developmental and epileptic encephalopathy, and seizure-related genes (SRG), which are characterized by the presence of seizures and gross brain malformations. We find that compared to the other two groups of genes, DEEGs are highly expressed within the adult CNS, exhibit the highest and most dynamic expression in various brain regions across development, and are significantly enriched in GABAergic neurons. Our analysis provides an overview of the expression pattern of epilepsy-associated genes with spatiotemporal resolution and establishes a broad expression-phenotype correlation in epilepsy.
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Affiliation(s)
- Wanhao Chi
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
| | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
- Simpson Querrey Institute, Northwestern University, Chicago, IL, 60611, USA.
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
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6
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Brown JA, Faley SL, Judge M, Ward P, Ihrie RA, Carson R, Armstrong L, Sahin M, Wikswo JP, Ess KC, Neely MD. Rescue of Impaired Blood-Brain Barrier in Tuberous Sclerosis Complex Patient Derived Neurovascular Unit. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571738. [PMID: 38168450 PMCID: PMC10760190 DOI: 10.1101/2023.12.15.571738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Tuberous sclerosis complex (TSC) is a multi-system genetic disease that causes benign tumors in the brain and other vital organs. The most debilitating symptoms result from involvement of the central nervous system and lead to a multitude of severe symptoms including seizures, intellectual disability, autism, and behavioral problems. TSC is caused by heterozygous mutations of either the TSC1 or TSC2 gene. Dysregulation of mTOR kinase with its multifaceted downstream signaling alterations is central to disease pathogenesis. Although the neurological sequelae of the disease are well established, little is known about how these mutations might affect cellular components and the function of the blood-brain barrier (BBB). We generated disease-specific cell models of the BBB by leveraging human induced pluripotent stem cell and microfluidic cell culture technologies. Using these microphysiological systems, we demonstrate that the BBB generated from TSC2 heterozygous mutant cells shows increased permeability which can be rescued by wild type astrocytes and with treatment with rapamycin, an mTOR kinase inhibitor. Our results further demonstrate the utility of microphysiological systems to study human neurological disorders and advance our knowledge of the cell lineages contributing to TSC pathogenesis.
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Affiliation(s)
- Jacquelyn A Brown
- Dept. of Physics and Astronomy, Vanderbilt University
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University
| | - Shannon L Faley
- Dept. of Physics and Astronomy, Vanderbilt University
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University
| | - Monika Judge
- Dept. of Physics and Astronomy, Vanderbilt University
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University
| | - Patricia Ward
- Dept. of Physics and Astronomy, Vanderbilt University
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University
| | - Rebecca A Ihrie
- Dept. of Cell & Developmental Biology, Vanderbilt University
- Neurological Surgery, Vanderbilt University Medical Center
| | - Robert Carson
- Dept. of Pediatrics, Vanderbilt University Medical Center
| | | | - Mustafa Sahin
- Rosamund Stone Translational Neuroscience Center, Dept. of Neurology, Boston Children's Hospital, Harvard Medical School
| | - John P Wikswo
- Dept. of Physics and Astronomy, Vanderbilt University
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University
- Dept. of Biomedical Engineering, Vanderbilt University
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University
| | - Kevin C Ess
- Neurological Surgery, Vanderbilt University Medical Center
- Dept. of Pediatrics, Vanderbilt University Medical Center
| | - M Diana Neely
- Dept. of Pediatrics, Vanderbilt University Medical Center
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7
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van Hugte EJH, Lewerissa EI, Wu KM, Scheefhals N, Parodi G, van Voorst TW, Puvogel S, Kogo N, Keller JM, Frega M, Schubert D, Schelhaas HJ, Verhoeven J, Majoie M, van Bokhoven H, Nadif Kasri N. SCN1A-deficient excitatory neuronal networks display mutation-specific phenotypes. Brain 2023; 146:5153-5167. [PMID: 37467479 PMCID: PMC10689919 DOI: 10.1093/brain/awad245] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/21/2023] [Accepted: 07/03/2023] [Indexed: 07/21/2023] Open
Abstract
Dravet syndrome is a severe epileptic encephalopathy, characterized by (febrile) seizures, behavioural problems and developmental delay. Eighty per cent of patients with Dravet syndrome have a mutation in SCN1A, encoding Nav1.1. Milder clinical phenotypes, such as GEFS+ (generalized epilepsy with febrile seizures plus), can also arise from SCN1A mutations. Predicting the clinical phenotypic outcome based on the type of mutation remains challenging, even when the same mutation is inherited within one family. This clinical and genetic heterogeneity adds to the difficulties of predicting disease progression and tailoring the prescription of anti-seizure medication. Understanding the neuropathology of different SCN1A mutations may help to predict the expected clinical phenotypes and inform the selection of best-fit treatments. Initially, the loss of Na+-current in inhibitory neurons was recognized specifically to result in disinhibition and consequently seizure generation. However, the extent to which excitatory neurons contribute to the pathophysiology is currently debated and might depend on the patient clinical phenotype or the specific SCN1A mutation. To examine the genotype-phenotype correlations of SCN1A mutations in relation to excitatory neurons, we investigated a panel of patient-derived excitatory neuronal networks differentiated on multi-electrode arrays. We included patients with different clinical phenotypes, harbouring various SCN1A mutations, along with a family in which the same mutation led to febrile seizures, GEFS+ or Dravet syndrome. We hitherto describe a previously unidentified functional excitatory neuronal network phenotype in the context of epilepsy, which corresponds to seizurogenic network prediction patterns elicited by proconvulsive compounds. We found that excitatory neuronal networks were affected differently, depending on the type of SCN1A mutation, but did not segregate according to clinical severity. Specifically, loss-of-function mutations could be distinguished from missense mutations, and mutations in the pore domain could be distinguished from mutations in the voltage sensing domain. Furthermore, all patients showed aggravated neuronal network responses at febrile temperatures compared with controls. Finally, retrospective drug screening revealed that anti-seizure medication affected GEFS+ patient- but not Dravet patient-derived neuronal networks in a patient-specific and clinically relevant manner. In conclusion, our results indicate a mutation-specific excitatory neuronal network phenotype, which recapitulates the foremost clinically relevant features, providing future opportunities for precision therapies.
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Affiliation(s)
- Eline J H van Hugte
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
- Department of Epileptology, ACE Kempenhaeghe, 5591 VE Heeze, The Netherlands
| | - Elly I Lewerissa
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Ka Man Wu
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
| | - Nicky Scheefhals
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
| | - Giulia Parodi
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, 16145 GE Genova, Italy
| | - Torben W van Voorst
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Sofia Puvogel
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
| | - Naoki Kogo
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Jason M Keller
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Monica Frega
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Helenius J Schelhaas
- Department of Neurology, Stichting Epilepsie Instellingen Nederland (SEIN), 2103 SW Heemstede, The Netherlands
| | - Judith Verhoeven
- Department of Epileptology, ACE Kempenhaeghe, 5591 VE Heeze, The Netherlands
| | - Marian Majoie
- Department of Epileptology, ACE Kempenhaeghe, 5591 VE Heeze, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
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Miguel Sanz C, Martinez Navarro M, Caballero Diaz D, Sanchez-Elexpuru G, Di Donato V. Toward the use of novel alternative methods in epilepsy modeling and drug discovery. Front Neurol 2023; 14:1213969. [PMID: 37719765 PMCID: PMC10501616 DOI: 10.3389/fneur.2023.1213969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Epilepsy is a chronic brain disease and, considering the amount of people affected of all ages worldwide, one of the most common neurological disorders. Over 20 novel antiseizure medications (ASMs) have been released since 1993, yet despite substantial advancements in our understanding of the molecular mechanisms behind epileptogenesis, over one-third of patients continue to be resistant to available therapies. This is partially explained by the fact that the majority of existing medicines only address seizure suppression rather than underlying processes. Understanding the origin of this neurological illness requires conducting human neurological and genetic studies. However, the limitation of sample sizes, ethical concerns, and the requirement for appropriate controls (many patients have already had anti-epileptic medication exposure) in human clinical trials underscore the requirement for supplemental models. So far, mammalian models of epilepsy have helped to shed light on the underlying causes of the condition, but the high costs related to breeding of the animals, low throughput, and regulatory restrictions on their research limit their usefulness in drug screening. Here, we present an overview of the state of art in epilepsy modeling describing gold standard animal models used up to date and review the possible alternatives for this research field. Our focus will be mainly on ex vivo, in vitro, and in vivo larval zebrafish models contributing to the 3R in epilepsy modeling and drug screening. We provide a description of pharmacological and genetic methods currently available but also on the possibilities offered by the continued development in gene editing methodologies, especially CRISPR/Cas9-based, for high-throughput disease modeling and anti-epileptic drugs testing.
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Tahara M, Higurashi N, Hata J, Nishikawa M, Ito K, Hirose S, Kaneko T, Mashimo T, Sakuma T, Yamamoto T, Okano HJ. Developmental changes in brain activity of heterozygous Scn1a knockout rats. Front Neurol 2023; 14:1125089. [PMID: 36998780 PMCID: PMC10043303 DOI: 10.3389/fneur.2023.1125089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/20/2023] [Indexed: 03/17/2023] Open
Abstract
IntroductionDravet syndrome (DS) is an infantile-onset developmental and epileptic encephalopathy characterized by an age-dependent evolution of drug-resistant seizures and poor developmental outcomes. Functional impairment of gamma-aminobutyric acid (GABA)ergic interneurons due to loss-of-function mutation of SCN1A is currently considered the main pathogenesis. In this study, to better understand the age-dependent changes in the pathogenesis of DS, we characterized the activity of different brain regions in Scn1a knockout rats at each developmental stage.MethodsWe established an Scn1a knockout rat model and examined brain activity from postnatal day (P) 15 to 38 using a manganese-enhanced magnetic resonance imaging technique (MEMRI).ResultsScn1a heterozygous knockout (Scn1a+/−) rats showed a reduced expression of voltage-gated sodium channel alpha subunit 1 protein in the brain and heat-induced seizures. Neural activity was significantly higher in widespread brain regions of Scn1a+/− rats than in wild-type rats from P19 to P22, but this difference did not persist thereafter. Bumetanide, a Na+-K+-2Cl− cotransporter 1 inhibitor, mitigated hyperactivity to the wild-type level, although no change was observed in the fourth postnatal week. Bumetanide also increased heat-induced seizure thresholds of Scn1a+/− rats at P21.ConclusionsIn Scn1a+/− rats, neural activity in widespread brain regions increased during the third postnatal week, corresponding to approximately 6 months of age in humans, when seizures most commonly develop in DS. In addition to impairment of GABAergic interneurons, the effects of bumetanide suggest a possible contribution of immature type A gamma-aminobutyric acid receptor signaling to transient hyperactivity and seizure susceptibility during the early stage of DS. This hypothesis should be addressed in the future. MEMRI is a potential technique for visualizing changes in basal brain activity in developmental and epileptic encephalopathies.
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Affiliation(s)
- Mayu Tahara
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Norimichi Higurashi
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- *Correspondence: Norimichi Higurashi
| | - Junichi Hata
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku, Tokyo, Japan
| | - Masako Nishikawa
- Clinical Research Support Center, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Ken Ito
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Shinichi Hirose
- General Medical Research Center, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Takehito Kaneko
- Division of Fundamental and Applied Sciences, Graduate School of Science and Engineering, Iwate University, Morioka, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - Tetsushi Sakuma
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takashi Yamamoto
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Hirotaka James Okano
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Hirotaka James Okano
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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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Human In Vitro Models of Epilepsy Using Embryonic and Induced Pluripotent Stem Cells. Cells 2022; 11:cells11243957. [PMID: 36552721 PMCID: PMC9776452 DOI: 10.3390/cells11243957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
The challenges in making animal models of complex human epilepsy phenotypes with varied aetiology highlights the need to develop alternative disease models that can address the limitations of animal models by effectively recapitulating human pathophysiology. The advances in stem cell technology provide an opportunity to use human iPSCs to make disease-in-a-dish models. The focus of this review is to report the current information and progress in the generation of epileptic patient-specific iPSCs lines, isogenic control cell lines, and neuronal models. These in vitro models can be used to study the underlying pathological mechanisms of epilepsies, anti-seizure medication resistance, and can also be used for drug testing and drug screening with their isogenic control cell lines.
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Concise Review: Stem Cell Models of SCN1A-Related Encephalopathies—Current Perspective and Future Therapies. Cells 2022; 11:cells11193119. [PMID: 36231081 PMCID: PMC9561991 DOI: 10.3390/cells11193119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations in the SCN1A gene can cause a variety of phenotypes, ranging from mild forms, such as febrile seizures and generalized epilepsy with febrile seizures plus, to severe, such as Dravet and non-Dravet developmental epileptic encephalopathies. Until now, more than two thousand pathogenic variants of the SCN1A gene have been identified and different pathogenic mechanisms (loss vs. gain of function) described, but the precise molecular mechanisms responsible for the deficits exhibited by patients are not fully elucidated. Additionally, the phenotypic variability proves the involvement of other genetic factors in its final expression. This is the reason why animal models and cell line models used to explore the molecular pathology of SCN1A-related disorders are only of limited use. The results of studies based on such models cannot be directly translated to affected individuals because they do not address each patient’s unique genetic background. The generation of functional neurons and glia for patient-derived iPSCs, together with the generation of isogenic controls using CRISPR/Cas technology, and finally, the 3D brain organoid models, seem to be a good way to solve this problem. Here, we review SCN1A-related encephalopathies, as well as the stem cell models used to explore their molecular basis.
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Tanenhaus A, Stowe T, Young A, McLaughlin J, Aeran R, Lin IW, Li J, Hosur R, Chen M, Leedy J, Chou T, Pillay S, Vila MC, Kearney JA, Moorhead M, Belle A, Tagliatela S. Cell-Selective Adeno-Associated Virus-Mediated SCN1A Gene Regulation Therapy Rescues Mortality and Seizure Phenotypes in a Dravet Syndrome Mouse Model and Is Well Tolerated in Nonhuman Primates. Hum Gene Ther 2022; 33:579-597. [PMID: 35435735 PMCID: PMC9242722 DOI: 10.1089/hum.2022.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Dravet syndrome (DS) is a developmental and epileptic encephalopathy caused by monoallelic loss-of-function variants in the SCN1A gene. SCN1A encodes for the alpha subunit of the voltage-gated type I sodium channel (NaV1.1), the primary voltage-gated sodium channel responsible for generation of action potentials in GABAergic inhibitory interneurons. In these studies, we tested the efficacy of an adeno-associated virus serotype 9 (AAV9) SCN1A gene regulation therapy, AAV9-REGABA-eTFSCN1A, designed to target transgene expression to GABAergic inhibitory neurons and reduce off-target expression within excitatory cells, in the Scn1a+/- mouse model of DS. Biodistribution and preliminary safety were evaluated in nonhuman primates (NHPs). AAV9-REGABA-eTFSCN1A was engineered to upregulate SCN1A expression levels within GABAergic inhibitory interneurons to correct the underlying haploinsufficiency and circuit dysfunction. A single bilateral intracerebroventricular (ICV) injection of AAV9-REGABA-eTFSCN1A in Scn1a+/- postnatal day 1 mice led to increased SCN1A mRNA transcripts, specifically within GABAergic inhibitory interneurons, and NaV1.1 protein levels in the brain. This was associated with a significant decrease in the occurrence of spontaneous and hyperthermia-induced seizures, and prolonged survival for over a year. In NHPs, delivery of AAV9-REGABA-eTFSCN1A by unilateral ICV injection led to widespread vector biodistribution and transgene expression throughout the brain, including key structures involved in epilepsy and cognitive behaviors, such as hippocampus and cortex. AAV9-REGABA-eTFSCN1A was well tolerated, with no adverse events during administration, no detectable changes in clinical observations, no adverse findings in histopathology, and no dorsal root ganglion-related toxicity. Our results support the clinical development of AAV9-REGABA-eTFSCN1A (ETX101) as an effective and targeted disease-modifying approach to SCN1A+ DS.
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Affiliation(s)
- Annie Tanenhaus
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Timothy Stowe
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Andrew Young
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - John McLaughlin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Rangoli Aeran
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - I. Winnie Lin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jianmin Li
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Ming Chen
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jennifer Leedy
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Tiffany Chou
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Sirika Pillay
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Jennifer A. Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Martin Moorhead
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Archana Belle
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Stephanie Tagliatela
- Encoded Therapeutics, Inc., South San Francisco, California, USA.,Correspondence: Stephanie Tagliatela, Encoded Therapeutics, Inc., 341 Oyster Point Boulevard, South San Francisco, CA 94080, USA.
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14
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Genetics and gene therapy in Dravet syndrome. Epilepsy Behav 2022; 131:108043. [PMID: 34053869 DOI: 10.1016/j.yebeh.2021.108043] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/02/2021] [Accepted: 05/02/2021] [Indexed: 12/17/2022]
Abstract
Dravet syndrome is a well-established electro-clinical condition first described in 1978. A main genetic cause was identified with the discovery of a loss-of-function SCN1A variant in 2001. Mechanisms underlying the phenotypic variations have subsequently been a main topic of research. Various genetic modifiers of clinical severities have been elucidated through many rigorous studies on genotype-phenotype correlations and the recent advances in next generation sequencing technology. Furthermore, a deeper understanding of the regulation of gene expression and remarkable progress on genome-editing technology using the CRISPR-Cas9 system provide significant opportunities to overcome hurdles of gene therapy, such as enhancing NaV1.1 expression. This article reviews the current understanding of genetic pathology and the status of research toward the development of gene therapy for Dravet syndrome. This article is part of the Special Issue "Severe Infantile Epilepsies".
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15
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Scalise S, Zannino C, Lucchino V, Lo Conte M, Scaramuzzino L, Cifelli P, D’Andrea T, Martinello K, Fucile S, Palma E, Gambardella A, Ruffolo G, Cuda G, Parrotta EI. Human iPSC Modeling of Genetic Febrile Seizure Reveals Aberrant Molecular and Physiological Features Underlying an Impaired Neuronal Activity. Biomedicines 2022; 10:biomedicines10051075. [PMID: 35625812 PMCID: PMC9138645 DOI: 10.3390/biomedicines10051075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/01/2023] Open
Abstract
Mutations in SCN1A gene, encoding the voltage-gated sodium channel (VGSC) NaV1.1, are widely recognized as a leading cause of genetic febrile seizures (FS), due to the decrease in the Na+ current density, mainly affecting the inhibitory neuronal transmission. Here, we generated induced pluripotent stem cells (iPSCs)-derived neurons (idNs) from a patient belonging to a genetically well-characterized Italian family, carrying the c.434T > C mutation in SCN1A gene (hereafter SCN1AM145T). A side-by-side comparison of diseased and healthy idNs revealed an overall maturation delay of SCN1AM145T cells. Membranes isolated from both diseased and control idNs were injected into Xenopus oocytes and both GABA and AMPA currents were successfully recorded. Patch-clamp measurements on idNs revealed depolarized action potential for SCN1AM145T, suggesting a reduced excitability. Expression analyses of VGSCs and chloride co-transporters NKCC1 and KCC2 showed a cellular “dysmaturity” of mutated idNs, strengthened by the high expression of SCN3A, a more fetal-like VGSC isoform, and a high NKCC1/KCC2 ratio, in mutated cells. Overall, we provide strong evidence for an intrinsic cellular immaturity, underscoring the role of mutant NaV1.1 in the development of FS. Furthermore, our data are strengthening previous findings obtained using transfected cells and recordings on human slices, demonstrating that diseased idNs represent a powerful tool for personalized therapy and ex vivo drug screening for human epileptic disorders.
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Affiliation(s)
- Stefania Scalise
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Clara Zannino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Valeria Lucchino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Michela Lo Conte
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Luana Scaramuzzino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Pierangelo Cifelli
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of Aquila, 67100 Aquila, Italy;
| | - Tiziano D’Andrea
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | | | - Sergio Fucile
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS Neuromed, Via Atinense, 86077 Pozzilli, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | - Antonio Gambardella
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS San Raffaele Roma, Via della Pisana, 00163 Rome, Italy
- Correspondence: (G.R.); (G.C.)
| | - Giovanni Cuda
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
- Correspondence: (G.R.); (G.C.)
| | - Elvira Immacolata Parrotta
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
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16
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Simkin D, Ambrosi C, Marshall KA, Williams LA, Eisenberg J, Gharib M, Dempsey GT, George AL, McManus OB, Kiskinis E. 'Channeling' therapeutic discovery for epileptic encephalopathy through iPSC technologies. Trends Pharmacol Sci 2022; 43:392-405. [PMID: 35427475 PMCID: PMC9119009 DOI: 10.1016/j.tips.2022.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 02/26/2022] [Accepted: 03/01/2022] [Indexed: 12/16/2022]
Abstract
Induced pluripotent stem cell (iPSC) and gene editing technologies have revolutionized the field of in vitro disease modeling, granting us access to disease-pertinent human cells of the central nervous system. These technologies are particularly well suited for the study of diseases with strong monogenic etiologies. Epilepsy is one of the most common neurological disorders in children, with approximately half of all genetic cases caused by mutations in ion channel genes. These channelopathy-associated epilepsies are clinically diverse, mechanistically complex, and hard to treat. Here, we review the genetic links to epilepsy, the opportunities and challenges of iPSC-based approaches for developing in vitro models of channelopathy-associated disorders, the available tools for effective phenotyping of iPSC-derived neurons, and discuss the potential therapeutic approaches for these devastating diseases.
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Affiliation(s)
- Dina Simkin
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Kelly A Marshall
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Jordyn Eisenberg
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mennat Gharib
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Alfred L George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Simpson Querrey Institute, Northwestern University, Chicago, IL 60611, USA; Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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17
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Sarkar AK, Nakamura S, Nakai K, Sato T, Shiga T, Abe Y, Hoashi Y, Inoue T, Akamatsu W, Baba K. Increased excitability of human iPSC-derived neurons in HTR2A variant-related sleep bruxism. Stem Cell Res 2022; 59:102658. [PMID: 34999422 DOI: 10.1016/j.scr.2022.102658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 12/05/2021] [Accepted: 01/02/2022] [Indexed: 10/19/2022] Open
Abstract
Sleep bruxism (SB) is a sleep-related movement disorder characterized by grinding and clenching of the teeth during sleep. We previously found a significant association between SB and a single nucleotide polymorphism (SNP), rs6313, in the neuronal serotonin 2A receptor gene (HTR2A), and established human induced pluripotent stem cell (iPSC)-derived neurons from SB patients with a genetic variant. To elucidate the electrophysiological characteristics of SB iPSC-derived neural cells bearing an SB-related genetic variant, we generated ventral hindbrain neurons from SB patients and unaffected controls, and explored the intrinsic membrane properties of these neurons using the patch-clamp technique. We found that the electrophysiological properties of iPSC-derived neurons mature in a time-dependent manner in long-term control cultures. SB neurons exhibited higher action potential firing frequency, higher gain, and shorter action potential half duration. This is the first in vitro modeling of SB using patient-specific iPSCs. The revealed electrophysiological characteristics may serve as a benchmark for further investigation of pathogenic mechanisms underlying SB. Moreover, our results on long-term cultures provide a strategy to define the functional maturity of human neurons in vitro, which can be implemented for stem cell research of neurogenesis, and neurodevelopmental disorders.
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Affiliation(s)
- Avijite Kumer Sarkar
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
| | - Shiro Nakamura
- Department of Oral Physiology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
| | - Kento Nakai
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
| | - Taro Sato
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
| | - Takahiro Shiga
- Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Yuka Abe
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
| | - Yurie Hoashi
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
| | - Tomio Inoue
- Department of Oral Physiology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
| | - Wado Akamatsu
- Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Kazuyoshi Baba
- Department of Prosthodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan.
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18
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Casalia ML, Casabona JC, García C, Cavaliere Candedo V, Quintá HR, Farías MI, Gonzalez J, Gonzalez Morón D, Córdoba M, Consalvo D, Mostoslavsky G, Urbano FJ, Pasquini J, Murer MG, Rela L, Kauffman MA, Pitossi FJ. A familiar study on self-limited childhood epilepsy patients using hIPSC-derived neurons shows a bias towards immaturity at the morphological, electrophysiological and gene expression levels. Stem Cell Res Ther 2021; 12:590. [PMID: 34823607 PMCID: PMC8620942 DOI: 10.1186/s13287-021-02658-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 10/31/2021] [Indexed: 12/28/2022] Open
Abstract
Background Self-limited Childhood Epilepsies are the most prevalent epileptic syndrome in children. Its pathogenesis is unknown. In this disease, symptoms resolve spontaneously in approximately 50% of patients when maturity is reached, prompting to a maturation problem. The purpose of this study was to understand the molecular bases of this disease by generating and analyzing induced pluripotent stem cell-derived neurons from a family with 7 siblings, among whom 4 suffer from this disease.
Methods Two affected siblings and, as controls, a healthy sister and the unaffected mother of the family were studied. Using exome sequencing, a homozygous variant in the FYVE, RhoGEF and PH Domain Containing 6 gene was identified in the patients as a putative genetic factor that could contribute to the development of this familial disorder. After informed consent was signed, skin biopsies from the 4 individuals were collected, fibroblasts were derived and reprogrammed and neurons were generated and characterized by markers and electrophysiology. Morphological, electrophysiological and gene expression analyses were performed on these neurons. Results Bona fide induced pluripotent stem cells and derived neurons could be generated in all cases. Overall, there were no major shifts in neuronal marker expression among patient and control-derived neurons. Compared to two familial controls, neurons from patients showed shorter axonal length, a dramatic reduction in synapsin-1 levels and cytoskeleton disorganization. In addition, neurons from patients developed a lower action potential threshold with time of in vitro differentiation and the amount of current needed to elicit an action potential (rheobase) was smaller in cells recorded from NE derived from patients at 12 weeks of differentiation when compared with shorter times in culture. These results indicate an increased excitability in patient cells that emerges with the time in culture. Finally, functional genomic analysis showed a biased towards immaturity in patient-derived neurons. Conclusions We are reporting the first in vitro model of self-limited childhood epilepsy, providing the cellular bases for future in-depth studies to understand its pathogenesis. Our results show patient-specific neuronal features reflecting immaturity, in resonance with the course of the disease and previous imaging studies. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02658-2.
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Affiliation(s)
| | | | - Corina García
- Institute Leloir Foundation- IIBBA-CONICET, Buenos Aires, Argentina
| | | | - Héctor Ramiro Quintá
- CONICET and Laboratorio de Medicina Experimental "Dr. J Toblli", Hospital Alemán, Buenos Aires, Argentina
| | | | - Joaquín Gonzalez
- Institute Leloir Foundation- IIBBA-CONICET, Buenos Aires, Argentina
| | - Dolores Gonzalez Morón
- Consultorio y Laboratorio de Neurogenética, Centro Universitario de Neurología "José María Ramos Mejía" Facultad de Medicina, UBA & Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, Universidad Austral-CONICET, Buenos Aires, Argentina
| | - Marta Córdoba
- Consultorio y Laboratorio de Neurogenética, Centro Universitario de Neurología "José María Ramos Mejía" Facultad de Medicina, UBA & Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, Universidad Austral-CONICET, Buenos Aires, Argentina
| | - Damian Consalvo
- Consultorio y Laboratorio de Neurogenética, Centro Universitario de Neurología "José María Ramos Mejía" Facultad de Medicina, UBA & Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, Universidad Austral-CONICET, Buenos Aires, Argentina
| | - Gustavo Mostoslavsky
- Center For Regenerative Medicine (CReM) of Boston University and Boston Medical Center, Boston, USA
| | - Francisco J Urbano
- Department of Physiology, Molecular and Cellular Biology "Dr. Héctor Maldonado", Faculty of Exact and Natural Sciences, University of Buenos Aires, IFIBYNE-CONICET, Buenos Aires, Argentina
| | - Juana Pasquini
- Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Mario Gustavo Murer
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Ciencias Fisiológicas, Grupo de Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires - CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Buenos Aires, Argentina
| | - Lorena Rela
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Ciencias Fisiológicas, Grupo de Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires - CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Buenos Aires, Argentina
| | - Marcelo A Kauffman
- Consultorio y Laboratorio de Neurogenética, Centro Universitario de Neurología "José María Ramos Mejía" Facultad de Medicina, UBA & Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, Universidad Austral-CONICET, Buenos Aires, Argentina.
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19
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Arribas-Blázquez M, Piniella D, Olivos-Oré LA, Bartolomé-Martín D, Leite C, Giménez C, Artalejo AR, Zafra F. Regulation of the voltage-dependent sodium channel Na V1.1 by AKT1. Neuropharmacology 2021; 197:108745. [PMID: 34375627 DOI: 10.1016/j.neuropharm.2021.108745] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/09/2021] [Accepted: 08/02/2021] [Indexed: 11/28/2022]
Abstract
The voltage-sensitive sodium channel NaV1.1 plays a critical role in regulating excitability of GABAergic neurons and mutations in the corresponding gene are associated to Dravet syndrome and other forms of epilepsy. The activity of this channel is regulated by several protein kinases. To identify novel regulatory kinases we screened a library of activated kinases and we found that AKT1 was able to directly phosphorylate NaV1.1. In vitro kinase assays revealed that the phosphorylation site was located in the C-terminal part of the large intracellular loop connecting domains I and II of NaV1.1, a region that is known to be targeted by other kinases like PKA and PKC. Electrophysiological recordings revealed that activated AKT1 strongly reduced peak Na+ currents and displaced the inactivation curve to more negative potentials in HEK-293 cell stably expressing NaV1.1. These alterations in current amplitude and steady-state inactivation were mimicked by SC79, a specific activator of AKT1, and largely reverted by triciribine, a selective inhibitor. Neurons expressing endogenous NaV1.1 in primary cultures were identified by expressing a fluorescent protein under the NaV1.1 promoter. There, we also observed a strong decrease in the current amplitude after addition of SC79, but small effects on the inactivation parameters. Altogether, we propose a novel mechanism that might regulate the excitability of neural networks in response to AKT1, a kinase that plays a pivotal role under physiological and pathological conditions, including epileptogenesis.
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Affiliation(s)
- Marina Arribas-Blázquez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Dolores Piniella
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Luis A Olivos-Oré
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain; Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - David Bartolomé-Martín
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristiana Leite
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Cecilio Giménez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio R Artalejo
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain; Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Francisco Zafra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain.
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New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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21
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In vitro monitoring of HTR2A-positive neurons derived from human-induced pluripotent stem cells. Sci Rep 2021; 11:15437. [PMID: 34326453 PMCID: PMC8322101 DOI: 10.1038/s41598-021-95041-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/20/2021] [Indexed: 11/08/2022] Open
Abstract
The serotonin 5-HT2A receptor (5-HT2AR) has been receiving increasing attention because its genetic variants have been associated with a variety of neurological diseases. To elucidate the pathogenesis of the neurological diseases associated with 5-HT2AR gene (HTR2A) variants, we have previously established a protocol to induce HTR2A-expressing neurons from human-induced pluripotent stem cells (hiPSCs). Here, we investigated the maturation stages and electrophysiological properties of HTR2A-positive neurons induced from hiPSCs and constructed an HTR2A promoter-specific reporter lentivirus to label the neurons. We found that neuronal maturity increased over time and that HTR2A expression was induced at the late stage of neuronal maturation. Furthermore, we demonstrated successful labelling of the HTR2A-positive neurons, which had fluorescence and generated repetitive action potentials in response to depolarizing currents and an inward current during the application of TCB-2, a selective agonist of 5-HT2ARs, respectively. These results indicated that our in vitro model mimicked the in vivo dynamics of 5-HT2AR. Therefore, in vitro monitoring of the function of HTR2A-positive neurons induced from hiPSCs could help elucidate the pathophysiological mechanisms of neurological diseases associated with genetic variations of the HTR2A gene.
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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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Uchino K, Kawano H, Tanaka Y, Adaniya Y, Asahara A, Deshimaru M, Kubota K, Watanabe T, Katsurabayashi S, Iwasaki K, Hirose S. Inhibitory synaptic transmission is impaired at higher extracellular Ca 2+ concentrations in Scn1a +/- mouse model of Dravet syndrome. Sci Rep 2021; 11:10634. [PMID: 34017040 PMCID: PMC8137694 DOI: 10.1038/s41598-021-90224-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/07/2021] [Indexed: 12/17/2022] Open
Abstract
Dravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na+ channels in the brain. However, the detailed pathogenesis of DS remains unclear. This study investigated the synaptic pathogenesis of this disease in terms of excitatory/inhibitory balance using a mouse model of DS. We show that excitatory postsynaptic currents were similar between Scn1a knock-in neurons (Scn1a+/- neurons) and wild-type neurons, but inhibitory postsynaptic currents were significantly lower in Scn1a+/- neurons. Moreover, both the vesicular release probability and the number of inhibitory synapses were significantly lower in Scn1a+/- neurons compared with wild-type neurons. There was no proportional increase in inhibitory postsynaptic current amplitude in response to increased extracellular Ca2+ concentrations. Our study revealed that the number of inhibitory synapses is significantly reduced in Scn1a+/- neurons, while the sensitivity of inhibitory synapses to extracellular Ca2+ concentrations is markedly increased. These data suggest that Ca2+ tethering in inhibitory nerve terminals may be disturbed following the synaptic burst, likely leading to epileptic symptoms.
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Affiliation(s)
- Kouya Uchino
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Hiroyuki Kawano
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Yasuyoshi Tanaka
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Yuna Adaniya
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Ai Asahara
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Masanobu Deshimaru
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan.
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Shinichi Hirose
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
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24
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Ademuwagun IA, Rotimi SO, Syrbe S, Ajamma YU, Adebiyi E. Voltage Gated Sodium Channel Genes in Epilepsy: Mutations, Functional Studies, and Treatment Dimensions. Front Neurol 2021; 12:600050. [PMID: 33841294 PMCID: PMC8024648 DOI: 10.3389/fneur.2021.600050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/01/2021] [Indexed: 12/19/2022] Open
Abstract
Genetic epilepsy occurs as a result of mutations in either a single gene or an interplay of different genes. These mutations have been detected in ion channel and non-ion channel genes. A noteworthy class of ion channel genes are the voltage gated sodium channels (VGSCs) that play key roles in the depolarization phase of action potentials in neurons. Of huge significance are SCN1A, SCN1B, SCN2A, SCN3A, and SCN8A genes that are highly expressed in the brain. Genomic studies have revealed inherited and de novo mutations in sodium channels that are linked to different forms of epilepsies. Due to the high frequency of sodium channel mutations in epilepsy, this review discusses the pathogenic mutations in the sodium channel genes that lead to epilepsy. In addition, it explores the functional studies on some known mutations and the clinical significance of VGSC mutations in the medical management of epilepsy. The understanding of these channel mutations may serve as a strong guide in making effective treatment decisions in patient management.
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Affiliation(s)
- Ibitayo Abigail Ademuwagun
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Solomon Oladapo Rotimi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Steffen Syrbe
- Clinic for Pediatric and Adolescent Medicine, Heidelberg University, Heidelberg, Germany
| | | | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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25
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Poulin H, Chahine M. R1617Q epilepsy mutation slows Na V 1.6 sodium channel inactivation and increases the persistent current and neuronal firing. J Physiol 2021; 599:1651-1664. [PMID: 33442870 DOI: 10.1113/jp280838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/21/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS A human NaV 1.6 construct was established to study the biophysical consequences of the R1617Q mutation on NaV 1.6 identified in patients with unclassified epileptic encephalopathy and severe intellectual disability. The R1617Q mutation disrupts the inactivation process of the channel, and more specifically, slows the current decay, increases the persistent sodium current that was blocked by tetrodotoxin and riluzole, and disrupts the inactivation voltage-dependence and increases the kinetics of recovery. In native hippocampal neurons, the R1617Q mutation exhibited a significant increase in action potentials triggered in response to stimulation and a significant increase in the number of neurons that exhibited spontaneous activity compared to neurons expressing WT channels that were inhibited by riluzole. The abnormally persistent current activity caused by the disruption of the channel inactivation process in NaV 1.6/R1617Q may result in epileptic encephalopathy in patients. ABSTRACT The voltage-gated sodium channel NaV 1.6 is the most abundantly expressed sodium channel isoform in the central nervous system. It plays a critical role in saltatory and continuous conduction. Although over 40 NaV 1.6 mutations have been linked to epileptic encephalopathy, only a few have been functionally analysed. In the present study, we characterized a NaV 1.6 mutation (R1617Q) identified in patients with epileptic encephalopathy and intellectual disability. R1617Q substitutes an arginine for a glutamine in the S4 segment of domain IV, which plays a major role in coupling the activation and inactivation of sodium channels. We used patch-clamp to show that R1617Q is a gain-of-function mutation. It is typified by slower inactivation kinetics and a loss of inactivation of voltage-dependence, which result in a 2.5-fold increase in the window current. In addition, sodium currents exhibited an enhanced rate of recovery from inactivation, most likely due to the destabilization of the inactivation state. The alterations in the fast inactivation caused a significant increase in the persistent sodium current. Overexpression of R1617Q in rat hippocampal neurons resulted in an increase in action potential firing activity that was inhibited by riluzole, consistent with the gain-of-function observed. We conclude that the R1617Q mutation causes neuronal hyperexcitability and may result in epileptic encephalopathy.
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Affiliation(s)
- Hugo Poulin
- CERVO Brain Research Centre, Quebec City, Québec, Canada
| | - Mohamed Chahine
- CERVO Brain Research Centre, Quebec City, Québec, Canada.,Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Québec, Canada
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26
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Shin H, Jeong S, Lee JH, Sun W, Choi N, Cho IJ. 3D high-density microelectrode array with optical stimulation and drug delivery for investigating neural circuit dynamics. Nat Commun 2021; 12:492. [PMID: 33479237 PMCID: PMC7820464 DOI: 10.1038/s41467-020-20763-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/15/2020] [Indexed: 02/08/2023] Open
Abstract
Investigation of neural circuit dynamics is crucial for deciphering the functional connections among regions of the brain and understanding the mechanism of brain dysfunction. Despite the advancements of neural circuit models in vitro, technologies for both precisely monitoring and modulating neural activities within three-dimensional (3D) neural circuit models have yet to be developed. Specifically, no existing 3D microelectrode arrays (MEAs) have integrated capabilities to stimulate surrounding neurons and to monitor the temporal evolution of the formation of a neural network in real time. Herein, we present a 3D high-density multifunctional MEA with optical stimulation and drug delivery for investigating neural circuit dynamics within engineered 3D neural tissues. We demonstrate precise measurements of synaptic latencies in 3D neural networks. We expect our 3D multifunctional MEA to open up opportunities for studies of neural circuits through precise, in vitro investigations of neural circuit dynamics with 3D brain models.
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Affiliation(s)
- Hyogeun Shin
- Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Sohyeon Jeong
- Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Ju-Hyun Lee
- Department of Anatomy, Korea University College of Medicine, Seoul, Republic of Korea
| | - Woong Sun
- Department of Anatomy, Korea University College of Medicine, Seoul, Republic of Korea
| | - Nakwon Choi
- Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea.
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea.
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.
| | - Il-Joo Cho
- Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea.
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea.
- School of Electrical and Electronics Engineering, Yonsei University, Seoul, Republic of Korea.
- Yonsei-KIST Convergence Research Institute, Yonsei University, Seoul, Republic of Korea.
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27
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Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
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Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
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28
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Zhang X, Li Z, Liu Y, Gai Z. Great Expectations: Induced pluripotent stem cell technologies in neurodevelopmental impairments. Int J Med Sci 2021; 18:459-473. [PMID: 33390815 PMCID: PMC7757149 DOI: 10.7150/ijms.51842] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Somatic cells such as skin fibroblasts, umbilical cord blood, peripheral blood, urinary epithelial cells, etc., are transformed into induced pluripotent stem cells (iPSCs) by reprogramming technology, a milestone in the stem-cell research field. IPSCs are similar to embryonic stem cells (ESCs), exhibiting the potential to differentiate into various somatic cells. Still, the former avoid problems of immune rejection and medical ethics in the study of ESCs and clinical trials. Neurodevelopmental disorders are chronic developmental brain dysfunctions that affect cognition, exercise, social adaptability, behavior, etc. Due to various inherited or acquired causes, they seriously affect the physical and psychological health of infants and children. These include generalized stunting / mental disability (GDD/ID), Epilepsy, autism spectrum disease (ASD), and attention deficit hyperactivity disorder (ADHD). Most neurodevelopmental disorders are challenging to cure. Establishing a neurodevelopmental disorder system model is essential for researching and treating neurodevelopmental disorders. At this stage, the scarcity of samples is a bigger problem for studying neurological diseases based on the donor, ethics, etc. Some iPSCs are reprogrammed from somatic cells that carry disease-causing mutations. They differentiate into nerve cells by induction, which has the original characteristics of diseases. Disease-specific iPSCs are used to study the mechanism and pathogenesis of neurodevelopmental disorders. The process provided samples and the impetus for developing drugs and developing treatment plans for neurodevelopmental disorders. Here, this article mainly introduced the development of iPSCs, the currently established iPSCs disease models, and artificial organoids related to neurodevelopmental impairments. This technology will promote our understanding of neurodevelopmental impairments and bring great expectations to children with neurological disorders.
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Affiliation(s)
- Xue Zhang
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China.,Neonatal Intensive Care Unit, Children's Medical Center, The Second Hospital of Shandong University, Ji'nan 250033, China
| | - Zilong Li
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
| | - Yi Liu
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
| | - Zhongtao Gai
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
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29
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Sabitha KR, Shetty AK, Upadhya D. Patient-derived iPSC modeling of rare neurodevelopmental disorders: Molecular pathophysiology and prospective therapies. Neurosci Biobehav Rev 2020; 121:201-219. [PMID: 33370574 DOI: 10.1016/j.neubiorev.2020.12.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022]
Abstract
The pathological alterations that manifest during the early embryonic development due to inherited and acquired factors trigger various neurodevelopmental disorders (NDDs). Besides major NDDs, there are several rare NDDs, exhibiting specific characteristics and varying levels of severity triggered due to genetic and epigenetic anomalies. The rarity of subjects, paucity of neural tissues for detailed analysis, and the unavailability of disease-specific animal models have hampered detailed comprehension of rare NDDs, imposing heightened challenge to the medical and scientific community until a decade ago. The generation of functional neurons and glia through directed differentiation protocols for patient-derived iPSCs, CRISPR/Cas9 technology, and 3D brain organoid models have provided an excellent opportunity and vibrant resource for decoding the etiology of brain development for rare NDDs caused due to monogenic as well as polygenic disorders. The present review identifies cellular and molecular phenotypes demonstrated from patient-derived iPSCs and possible therapeutic opportunities identified for these disorders. New insights to reinforce the existing knowledge of the pathophysiology of these disorders and prospective therapeutic applications are discussed.
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Affiliation(s)
- K R Sabitha
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA.
| | - Dinesh Upadhya
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
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30
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The polymicrogyria-associated GPR56 promoter preferentially drives gene expression in developing GABAergic neurons in common marmosets. Sci Rep 2020; 10:21516. [PMID: 33299078 PMCID: PMC7726139 DOI: 10.1038/s41598-020-78608-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 10/27/2020] [Indexed: 11/08/2022] Open
Abstract
GPR56, a member of the adhesion G protein-coupled receptor family, is abundantly expressed in cells of the developing cerebral cortex, including neural progenitor cells and developing neurons. The human GPR56 gene has multiple presumptive promoters that drive the expression of the GPR56 protein in distinct patterns. Similar to coding mutations of the human GPR56 gene that may cause GPR56 dysfunction, a 15-bp homozygous deletion in the cis-regulatory element upstream of the noncoding exon 1 of GPR56 (e1m) leads to the cerebral cortex malformation and epilepsy. To clarify the expression profile of the e1m promoter-driven GPR56 in primate brain, we generated a transgenic marmoset line in which EGFP is expressed under the control of the human minimal e1m promoter. In contrast to the endogenous GPR56 protein, which is highly enriched in the ventricular zone of the cerebral cortex, EGFP is mostly expressed in developing neurons in the transgenic fetal brain. Furthermore, EGFP is predominantly expressed in GABAergic neurons, whereas the total GPR56 protein is evenly expressed in both GABAergic and glutamatergic neurons, suggesting the GABAergic neuron-preferential activity of the minimal e1m promoter. These results indicate a possible pathogenic role for GABAergic neuron in the cerebral cortex of patients with GPR56 mutations.
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31
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Chen Z, Rollo B, Antonic-Baker A, Anderson A, Ma Y, O'Brien TJ, Ge Z, Wang X, Kwan P. New era of personalised epilepsy management. BMJ 2020; 371:m3658. [PMID: 33037001 PMCID: PMC7541035 DOI: 10.1136/bmj.m3658] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The trial and error approach to epilepsy treatment has not changed for over a century but machine learning and patient derived stem cells promise a personalised and more effective strategy, argue Patrick Kwan and colleagues
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Affiliation(s)
- Zhibin Chen
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Ben Rollo
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Ana Antonic-Baker
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Alison Anderson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Yuanlin Ma
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Australia
| | - Zongyuan Ge
- Faculty of Engineering, Monash University, Melbourne, Australia
- eResearch Centre, Monash University, Melbourne, Australia
- Airdoc Research Australia, Melbourne, Australia
| | - Xuefeng Wang
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Patrick Kwan
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Australia
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32
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Hirose S, Tanaka Y, Shibata M, Kimura Y, Ishikawa M, Higurashi N, Yamamoto T, Ichise E, Chiyonobu T, Ishii A. Application of induced pluripotent stem cells in epilepsy. Mol Cell Neurosci 2020; 108:103535. [DOI: 10.1016/j.mcn.2020.103535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
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33
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Turner TJ, Zourray C, Schorge S, Lignani G. Recent advances in gene therapy for neurodevelopmental disorders with epilepsy. J Neurochem 2020; 157:229-262. [PMID: 32880951 PMCID: PMC8436749 DOI: 10.1111/jnc.15168] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022]
Abstract
Neurodevelopmental disorders can be caused by mutations in neuronal genes fundamental to brain development. These disorders have severe symptoms ranging from intellectually disability, social and cognitive impairments, and a subset are strongly linked with epilepsy. In this review, we focus on those neurodevelopmental disorders that are frequently characterized by the presence of epilepsy (NDD + E). We loosely group the genes linked to NDD + E with different neuronal functions: transcriptional regulation, intrinsic excitability and synaptic transmission. All these genes have in common a pivotal role in defining the brain architecture and function during early development, and when their function is altered, symptoms can present in the first stages of human life. The relationship with epilepsy is complex. In some NDD + E, epilepsy is a comorbidity and in others seizures appear to be the main cause of the pathology, suggesting that either structural changes (NDD) or neuronal communication (E) can lead to these disorders. Furthermore, grouping the genes that cause NDD + E, we review the uses and limitations of current models of the different disorders, and how different gene therapy strategies are being developed to treat them. We highlight where gene replacement may not be a treatment option, and where innovative therapeutic tools, such as CRISPR‐based gene editing, and new avenues of delivery are required. In general this group of genetically defined disorders, supported increasing knowledge of the mechanisms leading to neurological dysfunction serve as an excellent collection for illustrating the translational potential of gene therapy, including newly emerging tools.
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Affiliation(s)
- Thomas J Turner
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Clara Zourray
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Department of Pharmacology, UCL School of Pharmacy, London, UK
| | | | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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Abstract
Epilepsy is a common neurological disorder characterized by recurrent and
unprovoked seizures due to neuronal hyperactivity. A large proportion
of epilepsy cases begin during childhood. Causes of epilepsy include
stroke, infections, brain injury, genetic factors, or other factors
that alter brain structure and development, but in up to 50% of cases
the cause is unknown. Approximately 35% of patients have refractory
seizures that do not respond to medication. Animal models and in vitro
cultures have contributed to our understanding of epilepsy, but there
is a clear need for better models to explore the human brain in normal
and pathological conditions. Human pluripotent stem cell (PSC)
technologies opened the door for new models for analyzing brain
development and disease, especially conditions with a genetic
component. Initially, PSCs were differentiated into 2-dimensional
cultures of a homogenous population of neural cells, such as
glutamatergic excitatory or γ-aminobutyric acidergic inhibitory
neurons, as well as glial cells. Nevertheless, these cultures lacked
the structure and complexity of a human brain. In the last decade, PSC
technology has advanced to the next level through the development of
3-dimensional culture, called organoids. These organoids recapitulate
features of the human brain that are missing in animal models,
enabling a deeper study of the human brain. In this review, we will
summarize the current status of organoid research and its application
to epilepsy.
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Affiliation(s)
- Vanesa Nieto-Estévez
- Department of Biology and Brain Health Consortium, 414492The University of Texas at San Antonio, TX, USA
| | - Jenny Hsieh
- Department of Biology and Brain Health Consortium, 414492The University of Texas at San Antonio, TX, USA
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CRISPR/dCas9-based Scn1a gene activation in inhibitory neurons ameliorates epileptic and behavioral phenotypes of Dravet syndrome model mice. Neurobiol Dis 2020; 141:104954. [DOI: 10.1016/j.nbd.2020.104954] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/12/2023] Open
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Pernia C, Tobe BTD, O'Donnell R, Snyder EY. The Evolution of Stem Cells, Disease Modeling, and Drug Discovery for Neurological Disorders. Stem Cells Dev 2020; 29:1131-1141. [PMID: 32024446 DOI: 10.1089/scd.2019.0217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Human neurological disorders are among the most challenging areas of translational research. The difficulty of acquiring human neural samples or specific representative animal models has necessitated a multifaceted approach to understanding disease pathology and drug discovery. The dedifferentiation of somatic cells to human induced pluripotent stem cells (hiPSCs) for the generation of neural derivatives has broadened the capability of biomedical research to study human cell types in neurological disorders. The initial zeal for the potential of hiPSCs for immediate biomedical breakthroughs has evolved to more reasonable expectations. Over the past decade, hiPSC technology has demonstrated the capacity to successfully establish "disease in a dish" models of complex neurological disorders and to identify possible novel therapeutics. However, as hiPSCs are used more broadly, an increased understanding of the limitations of hiPSC studies is becoming more evident. In this study, we review the challenges of studying neurological disorders, the current limitations of stem cell-based disease modeling, and the degrees to which hiPSC studies to date have demonstrated the capacity to fill essential gaps in neurological research.
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Affiliation(s)
- Cameron Pernia
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, California, USA
| | - Brian T D Tobe
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, California, USA.,Department of Psychiatry, Veterans Administration Medical Center, La Jolla, California, USA
| | - Ryan O'Donnell
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, California, USA
| | - Evan Y Snyder
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, California, USA
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Hedrich UBS, Lauxmann S, Lerche H. SCN2A channelopathies: Mechanisms and models. Epilepsia 2020; 60 Suppl 3:S68-S76. [PMID: 31904120 DOI: 10.1111/epi.14731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/21/2019] [Indexed: 01/01/2023]
Abstract
Variants in the SCN2A gene, encoding the voltage-gated sodium channel NaV 1.2, cause a variety of neuropsychiatric syndromes with different severity ranging from self-limiting epilepsies with early onset to developmental and epileptic encephalopathy with early or late onset and intellectual disability (ID), as well as ID or autism without seizures. Functional analysis of channel defects demonstrated a genotype-phenotype correlation and suggested effective treatment options for one group of affected patients carrying gain-of-function variants. Here, we sum up the functional mechanisms underlying different phenotypes of patients with SCN2A channelopathies and present currently available models that can help in understanding SCN2A-related disorders.
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Affiliation(s)
- Ulrike B S Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
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Mantegazza M, Broccoli V. SCN1A/Na V 1.1 channelopathies: Mechanisms in expression systems, animal models, and human iPSC models. Epilepsia 2020; 60 Suppl 3:S25-S38. [PMID: 31904127 DOI: 10.1111/epi.14700] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/04/2019] [Indexed: 12/20/2022]
Abstract
Pathogenic SCN1A/NaV 1.1 mutations cause well-defined epilepsies, including genetic epilepsy with febrile seizures plus (GEFS+) and the severe epileptic encephalopathy Dravet syndrome. In addition, they cause a severe form of migraine with aura, familial hemiplegic migraine. Moreover, SCN1A/NaV 1.1 variants have been inferred as risk factors in other types of epilepsy. We review here the advancements obtained studying pathologic mechanisms of SCN1A/NaV 1.1 mutations with experimental systems. We present results gained with in vitro expression systems, gene-targeted animal models, and the induced pluripotent stem cell (iPSC) technology, highlighting advantages, limits, and pitfalls for each of these systems. Overall, the results obtained in the last two decades confirm that the initial pathologic mechanism of epileptogenic SCN1A/NaV 1.1 mutations is loss-of-function of NaV 1.1 leading to hypoexcitability of at least some types of γ-aminobutyric acid (GABA)ergic neurons (including cortical and hippocampal parvalbumin-positive and somatostatin-positive ones). Conversely, more limited results point to NaV 1.1 gain-of-function for familial hemiplegic migraine (FHM) mutations. Behind these relatively simple pathologic mechanisms, an unexpected complexity has been observed, in part generated by technical issues in experimental studies and in part related to intrinsically complex pathophysiologic responses and remodeling, which yet remain to be fully disentangled.
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Affiliation(s)
- Massimo Mantegazza
- University Cote d'Azur (UCA), CNRS UMR7275, INSERM, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Vania Broccoli
- San Raffaele Scientific Institute, Milan, Italy.,Institute of Neuroscience, National Research Council (CNR), Milan, Italy
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Sterlini B, Fruscione F, Baldassari S, Benfenati F, Zara F, Corradi A. Progress of Induced Pluripotent Stem Cell Technologies to Understand Genetic Epilepsy. Int J Mol Sci 2020; 21:ijms21020482. [PMID: 31940887 PMCID: PMC7013950 DOI: 10.3390/ijms21020482] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 12/20/2022] Open
Abstract
The study of the pathomechanisms by which gene mutations lead to neurological diseases has benefit from several cellular and animal models. Recently, induced Pluripotent Stem Cell (iPSC) technologies have made possible the access to human neurons to study nervous system disease-related mechanisms, and are at the forefront of the research into neurological diseases. In this review, we will focalize upon genetic epilepsy, and summarize the most recent studies in which iPSC-based technologies were used to gain insight on the molecular bases of epilepsies. Moreover, we discuss the latest advancements in epilepsy cell modeling. At the two dimensional (2D) level, single-cell models of iPSC-derived neurons lead to a mature neuronal phenotype, and now allow a reliable investigation of synaptic transmission and plasticity. In addition, functional characterization of cerebral organoids enlightens neuronal network dynamics in a three-dimensional (3D) structure. Finally, we discuss the use of iPSCs as the cutting-edge technology for cell therapy in epilepsy.
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Affiliation(s)
- Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy;
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy;
| | - Floriana Fruscione
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy;
| | - Simona Baldassari
- Unità Operativa Complessa Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova Italy, Via G. Gaslini 5, 16147 Genoa, Italy;
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy;
- Istituto di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy;
- Unità Operativa Complessa Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova Italy, Via G. Gaslini 5, 16147 Genoa, Italy;
- Correspondence: (F.Z.); (A.C.)
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy;
- Istituto di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
- Correspondence: (F.Z.); (A.C.)
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40
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Xie Y, Ng NN, Safrina OS, Ramos CM, Ess KC, Schwartz PH, Smith MA, O'Dowd DK. Comparisons of dual isogenic human iPSC pairs identify functional alterations directly caused by an epilepsy associated SCN1A mutation. Neurobiol Dis 2019; 134:104627. [PMID: 31786370 DOI: 10.1016/j.nbd.2019.104627] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/05/2019] [Accepted: 09/26/2019] [Indexed: 02/06/2023] Open
Abstract
Over 1250 mutations in SCN1A, the Nav1.1 voltage-gated sodium channel gene, are associated with seizure disorders including GEFS+. To evaluate how a specific mutation, independent of genetic background, causes seizure activity we generated two pairs of isogenic human iPSC lines by CRISPR/Cas9 gene editing. One pair is a control line from an unaffected sibling, and the mutated control carrying the GEFS+ K1270T SCN1A mutation. The second pair is a GEFS+ patient line with the K1270T mutation, and the corrected patient line. By comparing the electrophysiological properties in inhibitory and excitatory iPSC-derived neurons from these pairs, we found the K1270T mutation causes cell type-specific alterations in sodium current density and evoked firing, resulting in hyperactive neural networks. We also identified differences associated with genetic background and interaction between the mutation and genetic background. Comparisons within and between dual pairs of isogenic iPSC-derived neuronal cultures provide a novel platform for evaluating cellular mechanisms underlying a disease phenotype and for developing patient-specific anti-seizure therapies.
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Affiliation(s)
- Yunyao Xie
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Nathan N Ng
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Olga S Safrina
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Carmen M Ramos
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America
| | - Kevin C Ess
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Philip H Schwartz
- Children's Hospital of Orange County Research Institute, Orange, CA, United States of America
| | - Martin A Smith
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Diane K O'Dowd
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States of America.
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41
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Antill-O'Brien N, Bourke J, O'Connell CD. Layer-By-Layer: The Case for 3D Bioprinting Neurons to Create Patient-Specific Epilepsy Models. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3218. [PMID: 31581436 PMCID: PMC6804258 DOI: 10.3390/ma12193218] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 09/26/2019] [Accepted: 09/26/2019] [Indexed: 02/06/2023]
Abstract
The ability to create three-dimensional (3D) models of brain tissue from patient-derived cells, would open new possibilities in studying the neuropathology of disorders such as epilepsy and schizophrenia. While organoid culture has provided impressive examples of patient-specific models, the generation of organised 3D structures remains a challenge. 3D bioprinting is a rapidly developing technology where living cells, encapsulated in suitable bioink matrices, are printed to form 3D structures. 3D bioprinting may provide the capability to organise neuronal populations in 3D, through layer-by-layer deposition, and thereby recapitulate the complexity of neural tissue. However, printing neuron cells raises particular challenges since the biomaterial environment must be of appropriate softness to allow for the neurite extension, properties which are anathema to building self-supporting 3D structures. Here, we review the topic of 3D bioprinting of neurons, including critical discussions of hardware and bio-ink formulation requirements.
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Affiliation(s)
- Natasha Antill-O'Brien
- BioFab3D, Aikenhead Centre for Medical Discovery, St Vincent's Hospital Melbourne, Fitzroy, VIC 3065, Australia.
| | - Justin Bourke
- BioFab3D, Aikenhead Centre for Medical Discovery, St Vincent's Hospital Melbourne, Fitzroy, VIC 3065, Australia.
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, Innovation Campus, University of Wollongong, NSW 2522, Australia.
- Department of Medicine, St Vincent's Hospital Melbourne, University of Melbourne, Fitzroy, VIC 3065, Australia.
| | - Cathal D O'Connell
- BioFab3D, Aikenhead Centre for Medical Discovery, St Vincent's Hospital Melbourne, Fitzroy, VIC 3065, Australia.
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, Innovation Campus, University of Wollongong, NSW 2522, Australia.
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42
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Lybrand ZR, Goswami S, Hsieh J. Stem cells: A path towards improved epilepsy therapies. Neuropharmacology 2019; 168:107781. [PMID: 31539537 DOI: 10.1016/j.neuropharm.2019.107781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
Despite the immense growth of new anti-seizure drugs (ASDs), approximately one-third of epilepsy patients remain resistant to current treatment options. Advancements in whole genome sequencing technology continues to identify an increasing number of epilepsy-associated genes at a rate that is outpacing the development of in vivo animal models. Patient-derived induced pluripotent stem cells (iPSCs) show promise in providing a platform for modeling genetic epilepsies, high throughput drug screening, and personalized medicine. This is largely due to the ease of collecting donor cells for iPSC reprogramming, and their ability to be maintained in vitro, while preserving the patient's genetic background. In this review, we summarize the current state of iPSC research in epilepsy and closely related syndromes, discuss the growing need for high-throughput drug screening (HTS), and review the use of stem cell technology for the purpose of autologous transplantation for epilepsy stem cell therapy. Although the use of iPSC technology, as it applies to ASD discovery, is in its infancy, we highlight the significant progress that has been made in phenotype and assay development to facilitate systematic HTS for personalized medicine. 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)
- Zane R Lybrand
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Sonal Goswami
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jenny Hsieh
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA.
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43
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Transcriptomes of Dravet syndrome iPSC derived GABAergic cells reveal dysregulated pathways for chromatin remodeling and neurodevelopment. Neurobiol Dis 2019; 132:104583. [PMID: 31445158 DOI: 10.1016/j.nbd.2019.104583] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 07/31/2019] [Accepted: 08/20/2019] [Indexed: 02/06/2023] Open
Abstract
Dravet syndrome (DS) is an early onset refractory epilepsy typically caused by de novo heterozygous variants in SCN1A encoding the α-subunit of the neuronal sodium channel Nav1.1. The syndrome is characterized by age-related progression of seizures, cognitive decline and movement disorders. We hypothesized that the distinct neurodevelopmental features in DS are caused by the disruption of molecular pathways in Nav1.1 haploinsufficient cells resulting in perturbed neural differentiation and maturation. Here, we established DS-patient and control induced pluripotent stem cell derived neural progenitor cells (iPSC NPC) and GABAergic inter-neuronal (iPSC GABA) cells. The DS-patient iPSC GABA cells showed a shift in sodium current activation and a perturbed response to induced oxidative stress. Transcriptome analysis revealed specific dysregulations of genes for chromatin structure, mitotic progression, neural plasticity and excitability in DS-patient iPSC NPCs and DS-patient iPSC GABA cells versus controls. The transcription factors FOXM1 and E2F1, positive regulators of the disrupted pathways for histone modification and cell cycle regulation, were markedly up-regulated in DS-iPSC GABA lines. Our study highlights transcriptional changes and disrupted pathways of chromatin remodeling in Nav1.1 haploinsufficient GABAergic cells, providing a molecular framework that overlaps with that of neurodevelopmental disorders and other epilepsies.
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44
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Sun Y, Dolmetsch RE. Investigating the Therapeutic Mechanism of Cannabidiol in a Human Induced Pluripotent Stem Cell (iPSC)-Based Model of Dravet Syndrome. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 83:185-191. [PMID: 31186344 DOI: 10.1101/sqb.2018.83.038174] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Dravet syndrome is an infantile epileptic encephalopathy primarily caused by loss-of-function variants of the gene SCN1A Standard treatment regimens have very limited efficacy to combat the life-threatening seizures in Dravet syndrome or the behavioral-cognitive comorbidities of the disease. Recently there has been encouraging progress in developing new treatments for this disorder. One of the clinical advances is cannabidiol (CBD), a compound naturally found in cannabis and shown to further reduce convulsive seizures in patients when used together with existing drug regimens. Like many other natural products, the exact therapeutic mechanism of CBD remains undefined. Previously we have established a human cellular model of Dravet syndrome by differentiating patient-derived induced pluripotent stem cells (iPSCs) into telencephalic inhibitory and excitatory neurons. Here we have applied this model to investigate the antiepileptic mechanism(s) of CBD at the cellular level. We first determined the effect of escalating the concentrations of CBD on neuronal excitability, using primary culture of rat cortical neurons. We found modulatory effects on excitability at submicromolar concentrations and toxic effects at high concentrations (15 µM). We then tested CBD at 50 nM, a concentration that corresponds to the estimated human clinical exposure, in telencephalic neurons derived from a patient iPSC line and control cell line H9. This 50 nM of CBD increased the excitability of inhibitory neurons but decreased the excitability of excitatory neurons, without changing the amplitude of sodium currents in either cell type. Our findings suggest a cell type-dependent mechanism for the therapeutic action of CBD in Dravet syndrome that is independent of sodium channel activity.
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Affiliation(s)
- Yishan Sun
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139, USA.,Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Ricardo E Dolmetsch
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139, USA.,Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305, USA
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45
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Kuo FS, Cleary CM, LoTurco JJ, Chen X, Mulkey DK. Disordered breathing in a mouse model of Dravet syndrome. eLife 2019; 8:e43387. [PMID: 31025941 PMCID: PMC6506208 DOI: 10.7554/elife.43387] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Dravet syndrome (DS) is a form of epilepsy with a high incidence of sudden unexpected death in epilepsy (SUDEP). Respiratory failure is a leading cause of SUDEP, and DS patients' frequently exhibit disordered breathing. Despite this, mechanisms underlying respiratory dysfunction in DS are unknown. We found that mice expressing a DS-associated Scn1a missense mutation (A1783V) conditionally in inhibitory neurons (Slc32a1cre/+::Scn1aA1783V fl/+; defined as Scn1aΔE26) exhibit spontaneous seizures, die prematurely and present a respiratory phenotype including hypoventilation, apnea, and a diminished ventilatory response to CO2. At the cellular level in the retrotrapezoid nucleus (RTN), we found inhibitory neurons expressing the Scn1a A1783V variant are less excitable, whereas glutamatergic chemosensitive RTN neurons, which are a key source of the CO2/H+-dependent drive to breathe, are hyper-excitable in slices from Scn1aΔE26 mice. These results show loss of Scn1a function can disrupt respiratory control at the cellular and whole animal levels.
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Affiliation(s)
- Fu-Shan Kuo
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Colin M Cleary
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Joseph J LoTurco
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Xinnian Chen
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Daniel K Mulkey
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
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46
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Pacitti D, Privolizzi R, Bax BE. Organs to Cells and Cells to Organoids: The Evolution of in vitro Central Nervous System Modelling. Front Cell Neurosci 2019; 13:129. [PMID: 31024259 PMCID: PMC6465581 DOI: 10.3389/fncel.2019.00129] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/14/2019] [Indexed: 02/05/2023] Open
Abstract
With 100 billion neurons and 100 trillion synapses, the human brain is not just the most complex organ in the human body, but has also been described as "the most complex thing in the universe." The limited availability of human living brain tissue for the study of neurogenesis, neural processes and neurological disorders has resulted in more than a century-long strive from researchers worldwide to model the central nervous system (CNS) and dissect both its striking physiology and enigmatic pathophysiology. The invaluable knowledge gained with the use of animal models and post mortem human tissue remains limited to cross-species similarities and structural features, respectively. The advent of human induced pluripotent stem cell (hiPSC) and 3-D organoid technologies has revolutionised the approach to the study of human brain and CNS in vitro, presenting great potential for disease modelling and translational adoption in drug screening and regenerative medicine, also contributing beneficially to clinical research. We have surveyed more than 100 years of research in CNS modelling and provide in this review an historical excursus of its evolution, from early neural tissue explants and organotypic cultures, to 2-D patient-derived cell monolayers, to the latest development of 3-D cerebral organoids. We have generated a comprehensive summary of CNS modelling techniques and approaches, protocol refinements throughout the course of decades and developments in the study of specific neuropathologies. Current limitations and caveats such as clonal variation, developmental stage, validation of pluripotency and chromosomal stability, functional assessment, reproducibility, accuracy and scalability of these models are also discussed.
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Affiliation(s)
- Dario Pacitti
- Molecular and Clinical Sciences Research Institute, St George’s, University of London, London, United Kingdom
- College of Medicine and Health, St Luke’s Campus, University of Exeter, Exeter, United Kingdom
| | - Riccardo Privolizzi
- Gene Transfer Technology Group, Institute for Women’s Health, University College London, London, United Kingdom
| | - Bridget E. Bax
- Molecular and Clinical Sciences Research Institute, St George’s, University of London, London, United Kingdom
- *Correspondence: Bridget E. Bax,
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Jung-Klawitter S, Opladen T. Induced pluripotent stem cells (iPSCs) as model to study inherited defects of neurotransmission in inborn errors of metabolism. J Inherit Metab Dis 2018; 41:1103-1116. [PMID: 29980968 DOI: 10.1007/s10545-018-0225-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/08/2018] [Accepted: 06/25/2018] [Indexed: 11/29/2022]
Abstract
The ability to reprogram somatic cells to induced pluripotent stem cells (iPSCs) has revolutionized the way of modeling human disease. Especially for the modeling of rare human monogenetic diseases with limited numbers of patients available worldwide and limited access to the mostly affected tissues, iPSCs have become an invaluable tool. To study rare diseases affecting neurotransmitter biosynthesis and neurotransmission, stem cell models carrying patient-specific mutations have become highly important as most of the cell types present in the human brain and the central nervous system (CNS), including motoneurons, neurons, oligodendrocytes, astrocytes, and microglia, can be differentiated from iPSCs following distinct developmental programs. Differentiation can be performed using classical 2D differentiation protocols, thereby generating specific subtypes of neurons or glial cells in a dish. On the other side, 3D differentiation into "organoids" opened new ways to study misregulated developmental processes associated with rare neurological and neurometabolic diseases. For the analysis of defects in neurotransmission associated with rare neurometabolic diseases, different types of brain organoids have been made available during the last years including forebrain, midbrain and cerebral organoids. In this review, we illustrate reprogramming of somatic cells to iPSCs, differentiation in 2D and 3D, as well as already available disease-specific iPSC models, and discuss current and future applications of these techniques.
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Affiliation(s)
- Sabine Jung-Klawitter
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany.
| | - Thomas Opladen
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
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A Transient Developmental Window of Fast-Spiking Interneuron Dysfunction in a Mouse Model of Dravet Syndrome. J Neurosci 2018; 38:7912-7927. [PMID: 30104343 DOI: 10.1523/jneurosci.0193-18.2018] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 07/12/2018] [Accepted: 07/17/2018] [Indexed: 01/06/2023] Open
Abstract
Dravet syndrome is a severe, childhood-onset epilepsy largely due to heterozygous loss-of-function mutation of the gene SCN1A, which encodes the type 1 neuronal voltage-gated sodium (Na+) channel α subunit Nav1.1. Prior studies in mouse models of Dravet syndrome (Scn1a+/- mice) indicate that, in cerebral cortex, Nav1.1 is predominantly expressed in GABAergic interneurons, in particular in parvalbumin-positive fast-spiking basket cell interneurons (PVINs). This has led to a model of Dravet syndrome pathogenesis in which Nav1.1 mutation leads to preferential dysfunction of interneurons, decreased synaptic inhibition, hyperexcitability, and epilepsy. However, such studies have been implemented at early developmental time points. Here, we performed electrophysiological recordings in acute brain slices prepared from male and female Scn1a+/- mice as well as age-matched wild-type littermate controls and found that, later in development, the excitability of PVINs had normalized. Analysis of action potential waveforms indirectly suggests a reorganization of axonal Na+ channels in PVINs from Scn1a+/- mice, a finding supported by immunohistochemical data showing elongation of the axon initial segment. Our results imply that transient impairment of action potential generation by PVINs may contribute to the initial appearance of epilepsy, but is not the mechanism of ongoing, chronic epilepsy in Dravet syndrome.SIGNIFICANCE STATEMENT Dravet syndrome is characterized by normal early development, temperature-sensitive seizures in infancy, progression to treatment-resistant epilepsy, developmental delay, autism, and sudden unexplained death due to mutation in SCN1A encoding the Na+ channel subunit Nav1.1. Prior work has revealed a preferential impact of Nav1.1 loss on the function of GABAergic inhibitory interneurons. However, such data derive exclusively from recordings of neurons in young Scn1a+/- mice. Here, we show that impaired action potential generation observed in parvalbumin-positive fast-spiking interneurons (PVINs) in Scn1a+/- mice during early development has normalized by postnatal day 35. This work suggests that a transient impairment of PVINs contributes to epilepsy onset, but is not the mechanism of ongoing, chronic epilepsy in Dravet syndrome.
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Zhou R, Jiang G, Tian X, Wang X. Progress in the molecular mechanisms of genetic epilepsies using patient-induced pluripotent stem cells. Epilepsia Open 2018; 3:331-339. [PMID: 30187003 PMCID: PMC6119748 DOI: 10.1002/epi4.12238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2018] [Indexed: 12/29/2022] Open
Abstract
Research findings on the molecular mechanisms of epilepsy almost always originate from animal experiments, and the development of induced pluripotent stem cell (iPSC) technology allows the use of human cells with genetic defects for studying the molecular mechanisms of genetic epilepsy (GE) for the first time. With iPSC technology, terminally differentiated cells collected from GE patients with specific genetic etiologies can be differentiated into many relevant cell subtypes that carry all of the GE patient's genetic information. iPSCs have opened up a new research field involving the pathogenesis of GE. Using this approach, studies have found that gene mutations induce GE by altering the balance between neuronal excitation and inhibition, which is associated. among other factors, with neuronal developmental disturbances, ion channel abnormalities, and synaptic dysfunction. Simultaneously, astrocyte activation, mitochondrial dysfunction, and abnormal signaling pathway activity are also important factors in the molecular mechanisms of GE.
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Affiliation(s)
- Ruijiao Zhou
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Guohui Jiang
- Department of Neurology Institute of Neurological Diseases Affiliated Hospital of North Sichuan Medical College Nanchong China
| | - Xin Tian
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Xuefeng Wang
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
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Abstract
In the current review, we discuss the process of modeling pediatric epileptic encephalopathies with a focus on in vitro iPSC-based technologies. We highlight the potential benefits as well as the challenges of these approaches and propose appropriate standards for the field.
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