1
|
Doorn N. Unraveling Dravet Syndrome: Exploring the complex effects of sodium channel mutations on neuronal networks. Sci Prog 2024; 107:368504231225076. [PMID: 38373395 PMCID: PMC10878221 DOI: 10.1177/00368504231225076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Dravet Syndrome (DS) is a severe developmental epileptic encephalopathy with frequent intractable seizures accompanied by cognitive impairment, often caused by pathogenic variants in SCN1A encoding sodium channel NaV1.1. Recent research utilizing in vitro patient-derived neuronal networks and accompanying in silico models uncovered that not just sodium-but also potassium-and synaptic currents were impaired in DS networks. Here, we explore the implications of these findings for three questions that remain elusive in DS: How do sodium channel impairments result in epilepsy? How can identical variants lead to varying phenotypes? What mechanisms underlie the developmental delay in DS patients? We speculate that impaired potassium currents might be a secondary effect to NaV1.1 mutations and could result in hyperexcitable neurons and epileptic networks. Moreover, we reason that homeostatic plasticity is actively engaged in DS networks, possibly affecting the phenotype and impairing learning and development when driven to extremes.
Collapse
Affiliation(s)
- Nina Doorn
- Department of Clinical Neurophysiology, University of Twente, Enschede, The Netherlands
| |
Collapse
|
2
|
Mich JK, Ryu J, Wei AD, Gore BB, Guo R, Bard AM, Martinez RA, Bishaw Y, Luber E, Oliveira Santos LM, Miranda N, Ramirez JM, Ting JT, Lein ES, Levi BP, Kalume FK. AAV-mediated interneuron-specific gene replacement for Dravet syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571820. [PMID: 38168178 PMCID: PMC10760176 DOI: 10.1101/2023.12.15.571820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Dravet syndrome (DS) is a devastating developmental epileptic encephalopathy marked by treatment-resistant seizures, developmental delay, intellectual disability, motor deficits, and a 10-20% rate of premature death. Most DS patients harbor loss-of-function mutations in one copy of SCN1A , which has been associated with inhibitory neuron dysfunction. Here we developed an interneuron-targeting AAV human SCN1A gene replacement therapy using cell class-specific enhancers. We generated a split-intein fusion form of SCN1A to circumvent AAV packaging limitations and deliver SCN1A via a dual vector approach using cell class-specific enhancers. These constructs produced full-length Na V 1.1 protein and functional sodium channels in HEK293 cells and in brain cells in vivo . After packaging these vectors into enhancer-AAVs and administering to mice, immunohistochemical analyses showed telencephalic GABAergic interneuron-specific and dose-dependent transgene biodistribution. These vectors conferred strong dose-dependent protection against postnatal mortality and seizures in two DS mouse models carrying independent loss-of-function alleles of Scn1a, at two independent research sites, supporting the robustness of this approach. No mortality or toxicity was observed in wild-type mice injected with single vectors expressing either the N-terminal or C-terminal halves of SCN1A , or the dual vector system targeting interneurons. In contrast, nonselective neuronal targeting of SCN1A conferred less rescue against mortality and presented substantial preweaning lethality. These findings demonstrate proof-of-concept that interneuron-specific AAV-mediated SCN1A gene replacement is sufficient for significant rescue in DS mouse models and suggest it could be an effective therapeutic approach for patients with DS.
Collapse
|
3
|
Ricobaraza A, Bunuales M, Gonzalez-Aparicio M, Fadila S, Rubinstein M, Vides-Urrestarazu I, Banderas J, Sola-Sevilla N, Sanchez-Carpintero R, Lanciego JL, Roda E, Honrubia A, Arnaiz P, Hernandez-Alcoceba R. Preferential expression of SCN1A in GABAergic neurons improves survival and epileptic phenotype in a mouse model of Dravet syndrome. J Mol Med (Berl) 2023; 101:1587-1601. [PMID: 37819378 PMCID: PMC10697872 DOI: 10.1007/s00109-023-02383-8] [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: 05/05/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The SCN1A gene encodes the alpha subunit of a voltage-gated sodium channel (Nav1.1), which is essential for the function of inhibitory neurons in the brain. Mutations in this gene cause severe encephalopathies such as Dravet syndrome (DS). Upregulation of SCN1A expression by different approaches has demonstrated promising therapeutic effects in preclinical models of DS. Limiting the effect to inhibitory neurons may contribute to the restoration of brain homeostasis, increasing the safety and efficacy of the treatment. In this work, we have evaluated different approaches to obtain preferential expression of the full SCN1A cDNA (6 Kb) in GABAergic neurons, using high-capacity adenoviral vectors (HC-AdV). In order to favour infection of these cells, we considered ErbB4 as a surface target. Incorporation of the EGF-like domain from neuregulin 1 alpha (NRG1α) in the fiber of adenovirus capsid allowed preferential infection in cells lines expressing ErbB4. However, it had no impact on the infectivity of the vector in primary cultures or in vivo. For transcriptional control of transgene expression, we developed a regulatory sequence (DP3V) based on the Distal-less homolog enhancer (Dlx), the vesicular GABA transporter (VGAT) promoter, and a portion of the SCN1A gene. The hybrid DP3V promoter allowed preferential expression of transgenes in GABAergic neurons both in vitro and in vivo. A new HC-AdV expressing SCN1A under the control of this promoter showed improved survival and amelioration of the epileptic phenotype in a DS mouse model. These results increase the repertoire of gene therapy vectors for the treatment of DS and indicate a new avenue for the refinement of gene supplementation in this disease. KEY MESSAGES: Adenoviral vectors can deliver the SCN1A cDNA and are amenable for targeting. An adenoviral vector displaying an ErbB4 ligand in the capsid does not target GABAergic neurons. A hybrid promoter allows preferential expression of transgenes in GABAergic neurons. Preferential expression of SCN1A in GABAergic cells is therapeutic in a Dravet syndrome model.
Collapse
Affiliation(s)
- Ana Ricobaraza
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Maria Bunuales
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Saja Fadila
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Irene Vides-Urrestarazu
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Julliana Banderas
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Noemi Sola-Sevilla
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
| | - Jose Luis Lanciego
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CiberNed), Madrid, Spain
| | - Elvira Roda
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Adriana Honrubia
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Patricia Arnaiz
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain.
| |
Collapse
|
4
|
Lopez L, De Waard S, Meudal H, Caumes C, Khakh K, Peigneur S, Oliveira-Mendes B, Lin S, De Waele J, Montnach J, Cestèle S, Tessier A, Johnson JP, Mantegazza M, Tytgat J, Cohen C, Béroud R, Bosmans F, Landon C, De Waard M. Structure-function relationship of new peptides activating human Na v1.1. Biomed Pharmacother 2023; 165:115173. [PMID: 37453200 DOI: 10.1016/j.biopha.2023.115173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Nav1.1 is an important pharmacological target as this voltage-gated sodium channel is involved in neurological and cardiac syndromes. Channel activators are actively sought to try to compensate for haploinsufficiency in several of these pathologies. Herein we used a natural source of new peptide compounds active on ion channels and screened for drugs capable to inhibit channel inactivation as a way to compensate for decreased channel function. We discovered that JzTx-34 is highly active on Nav1.1 and subsequently performed a full structure-activity relationship investigation to identify its pharmacophore. These experiments will help interpret the mechanism of action of this and formerly identified peptides as well as the future identification of new peptides. We also reveal structural determinants that make natural ICK peptides active against Nav1.1 challenging to synthesize. Altogether, the knowledge gained by this study will help facilitate the discovery and development of new compounds active on this critical ion channel target.
Collapse
Affiliation(s)
- Ludivine Lopez
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France
| | - Stephan De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France
| | - Hervé Meudal
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | | | - Kuldip Khakh
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | | | - Sophia Lin
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Jolien De Waele
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Jérôme Montnach
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - Sandrine Cestèle
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Agnès Tessier
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - J P Johnson
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Massimo Mantegazza
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Jan Tytgat
- University of Leuven, 3000 Leuven, Belgium
| | - Charles Cohen
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Céline Landon
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | - Michel De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France.
| |
Collapse
|
5
|
Doorn N, van Hugte EJH, Ciptasari U, Mordelt A, Meijer HGE, Schubert D, Frega M, Nadif Kasri N, van Putten MJAM. An in silico and in vitro human neuronal network model reveals cellular mechanisms beyond Na V1.1 underlying Dravet syndrome. Stem Cell Reports 2023; 18:1686-1700. [PMID: 37419110 PMCID: PMC10444571 DOI: 10.1016/j.stemcr.2023.06.003] [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: 01/10/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 07/09/2023] Open
Abstract
Human induced pluripotent stem cell (hiPSC)-derived neuronal networks on multi-electrode arrays (MEAs) provide a unique phenotyping tool to study neurological disorders. However, it is difficult to infer cellular mechanisms underlying these phenotypes. Computational modeling can utilize the rich dataset generated by MEAs, and advance understanding of disease mechanisms. However, existing models lack biophysical detail, or validation and calibration to relevant experimental data. We developed a biophysical in silico model that accurately simulates healthy neuronal networks on MEAs. To demonstrate the potential of our model, we studied neuronal networks derived from a Dravet syndrome (DS) patient with a missense mutation in SCN1A, encoding sodium channel NaV1.1. Our in silico model revealed that sodium channel dysfunctions were insufficient to replicate the in vitro DS phenotype, and predicted decreased slow afterhyperpolarization and synaptic strengths. We verified these changes in DS patient-derived neurons, demonstrating the utility of our in silico model to predict disease mechanisms.
Collapse
Affiliation(s)
- Nina Doorn
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, the Netherlands.
| | - Eline J H van Hugte
- Department of Neurology, Academic Center for Epileptology Kempenhaeghe, 5591 VE Heeze, the Netherlands; Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, the Netherlands; Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR Nijmegen, the Netherlands
| | - Ummi Ciptasari
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, the Netherlands; Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR Nijmegen, the Netherlands
| | - Annika Mordelt
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, the Netherlands; Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR Nijmegen, the Netherlands
| | - Hil G E Meijer
- Department of Applied Mathematics, University of Twente, 7522 NB Enschede, the Netherlands
| | - Dirk Schubert
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, the Netherlands; Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR Nijmegen, the Netherlands
| | - Monica Frega
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, the Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, 6500 HB Nijmegen, the Netherlands; Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR Nijmegen, the Netherlands
| | - Michel J A M van Putten
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, the Netherlands; Department of Neurology and Clinical Neurophysiology, Medisch Spectrum Twente, 7512 KZ Enschede, the Netherlands
| |
Collapse
|
6
|
Lemaire L, Desroches M, Krupa M, Mantegazza M. Idealized multiple-timescale model of cortical spreading depolarization initiation and pre-epileptic hyperexcitability caused by Na V1.1/SCN1A mutations. J Math Biol 2023; 86:92. [PMID: 37171678 DOI: 10.1007/s00285-023-01917-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 01/30/2023] [Accepted: 03/28/2023] [Indexed: 05/13/2023]
Abstract
NaV1.1 (SCN1A) is a voltage-gated sodium channel mainly expressed in GABAergic neurons. Loss of function mutations of NaV1.1 lead to epileptic disorders, while gain of function mutations cause a migraine in which cortical spreading depolarizations (CSDs) are involved. It is still debated how these opposite effects initiate two different manifestations of neuronal hyperactivity: epileptic seizures and CSD. To investigate this question, we previously built a conductance-based model of two neurons (GABAergic and pyramidal), with dynamic ion concentrations (Lemaire et al. in PLoS Comput Biol 17(7):e1009239, 2021. https://doi.org/10.1371/journal.pcbi.1009239 ). When implementing either NaV1.1 migraine or epileptogenic mutations, ion concentration modifications acted as slow processes driving the system to the corresponding pathological firing regime. However, the large dimensionality of the model complicated the exploitation of its implicit multi-timescale structure. Here, we substantially simplify our biophysical model to a minimal version more suitable for bifurcation analysis. The explicit timescale separation allows us to apply slow-fast theory, where slow variables are treated as parameters in the fast singular limit. In this setting, we reproduce both pathological transitions as dynamic bifurcations in the full system. In the epilepsy condition, we shift the spike-terminating bifurcation to lower inputs for the GABAergic neuron, to model an increased susceptibility to depolarization block. The resulting failure of synaptic inhibition triggers hyperactivity of the pyramidal neuron. In the migraine scenario, spiking-induced release of potassium leads to the abrupt increase of the extracellular potassium concentration. This causes a dynamic spike-terminating bifurcation of both neurons, which we interpret as CSD initiation.
Collapse
Affiliation(s)
- Louisiane Lemaire
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France.
- Institute for Theoretical Biology, Humboldt-University of Berlin, Berlin, Germany.
- Bernstein Center for Computational Neuroscience, Berlin, Germany.
| | - Mathieu Desroches
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France
| | - Martin Krupa
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France
- Laboratoire Jean-Alexandre Dieudonné, Université Côte d'Azur, Nice, France
| | - Massimo Mantegazza
- Institute of Molecular and Cellular Pharmacology (IPMC), Université Côte d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- INSERM, Valbonne-Sophia Antipolis, France
| |
Collapse
|
7
|
Mavashov A, Brusel M, Liu J, Woytowicz V, Bae H, Chen YH, Dani VS, Cardenal-Muñoz E, Spinosa V, Aibar JÁ, Rubinstein M. Heat-induced seizures, premature mortality, and hyperactivity in a novel Scn1a nonsense model for Dravet syndrome. Front Cell Neurosci 2023; 17:1149391. [PMID: 37206664 PMCID: PMC10191256 DOI: 10.3389/fncel.2023.1149391] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/05/2023] [Indexed: 05/21/2023] Open
Abstract
Dravet syndrome (Dravet) is a severe congenital developmental genetic epilepsy caused by de novo mutations in the SCN1A gene. Nonsense mutations are found in ∼20% of the patients, and the R613X mutation was identified in multiple patients. Here we characterized the epileptic and non-epileptic phenotypes of a novel preclinical Dravet mouse model harboring the R613X nonsense Scn1a mutation. Scn1aWT/R613X mice, on a mixed C57BL/6J:129S1/SvImJ background, exhibited spontaneous seizures, susceptibility to heat-induced seizures, and premature mortality, recapitulating the core epileptic phenotypes of Dravet. In addition, these mice, available as an open-access model, demonstrated increased locomotor activity in the open-field test, modeling some non-epileptic Dravet-associated phenotypes. Conversely, Scn1aWT/R613X mice, on the pure 129S1/SvImJ background, had a normal life span and were easy to breed. Homozygous Scn1aR613X/R613X mice (pure 129S1/SvImJ background) died before P16. Our molecular analyses of hippocampal and cortical expression demonstrated that the premature stop codon induced by the R613X mutation reduced Scn1a mRNA and NaV1.1 protein levels to ∼50% in heterozygous Scn1aWT/R613X mice (on either genetic background), with marginal expression in homozygous Scn1aR613X/R613X mice. Together, we introduce a novel Dravet model carrying the R613X Scn1a nonsense mutation that can be used to study the molecular and neuronal basis of Dravet, as well as the development of new therapies associated with SCN1A nonsense mutations in Dravet.
Collapse
Affiliation(s)
- Anat Mavashov
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jiaxing Liu
- Tevard Biosciences, Cambridge, MA, United States
| | | | - Haneui Bae
- Tevard Biosciences, Cambridge, MA, United States
| | | | | | | | | | | | - Moran Rubinstein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
| |
Collapse
|