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Ji J, Zhou X, Lu Y, Shen L, Li L, Chen Z, Shi Y, Liao W, Yu L. SCN1A intronic variants impact on Nav1.1 protein expression and sodium channel function, and associated with epilepsy phenotypic severity. Gene 2025; 932:148876. [PMID: 39173978 DOI: 10.1016/j.gene.2024.148876] [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: 03/12/2024] [Revised: 07/18/2024] [Accepted: 08/19/2024] [Indexed: 08/24/2024]
Abstract
High-throughput sequencing has identified numerous intronic variants in the SCN1A gene in epilepsy patients. Abnormal mRNA splicing caused by these variants can lead to significant phenotypic differences, but the mechanisms of epileptogenicity and phenotypic differences remain unknown. Two variants, c.4853-1 G>C and c.4853-25 T>A, were identified in intron 25 of SCN1A, which were associated with severe Dravet syndrome (DS) and mild focal epilepsy with febrile seizures plus (FEFS+), respectively. The impact of these variants on protein expression, electrophysiological properties of sodium channels and their correlation with epilepsy severity was investigated through plasmid construction and transfection based on the aberrant spliced mRNA. We found that the expression of truncated mutant proteins was significantly reduced on the cell membrane, and retained in the cytoplasmic endoplasmic reticulum. The mutants caused a decrease in current density, voltage sensitivity, and an increased vulnerability of channel, leading to a partial impairment of sodium channel function. Notably, the expression of DS-related mutant protein on the cell membrane was higher compared to that of FEFS+-related mutant, whereas the sodium channel function impairment caused by DS-related mutant was comparatively milder than that caused by FEFS+-related mutant. Our study suggests that differences in protein expression levels and altered electrophysiological properties of sodium channels play important roles in the manifestation of diverse epileptic phenotypes. The presence of intronic splice site variants may result in severe phenotypes due to the dominant-negative effects, whereas non-canonical splice site variants leading to haploinsufficiency could potentially cause milder phenotypes.
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Affiliation(s)
- Jingjing Ji
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Xijing Zhou
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China; Department of Neurology, The First People's Hospital of Nanning, the Fifth Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Yanting Lu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Lang Shen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Lixia Li
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Zirong Chen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Yiwu Shi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, GD, China
| | - Weiping Liao
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, GD, China
| | - Lu Yu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China.
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2
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Joseph DJ, Von Deimling M, Risbud R, McCoy AJ, Marsh ED. Loss of postnatal Arx transcriptional activity in parvalbumin interneurons reveals non-cell autonomous disturbances in CA1 pyramidal cells. Neuroscience 2024; 558:128-150. [PMID: 38788829 PMCID: PMC11381180 DOI: 10.1016/j.neuroscience.2024.05.020] [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: 07/19/2023] [Revised: 04/16/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
Maintenance of proper electrophysiological and connectivity profiles in the adult brain may be a perturbation point in neurodevelopmental disorders (NDDs). How these profiles are maintained within mature circuits is unclear. We recently demonstrated that postnatal ablation of the Aristaless (Arx) homeobox gene in parvalbumin interneurons (PVIs) alone led to dysregulation of their transcriptome and alterations in their functional as well as network properties in the hippocampal cornu Ammoni first region (CA1). Here, we characterized CA1 pyramidal cells (PCs) responses in this conditional knockout (CKO) mouse to further understand the circuit mechanisms by which postnatal Arx expression regulates mature CA1 circuits. Field recordings of network excitability showed that CA1 PC ensembles were less excitable in response to unpaired stimulations but exhibited enhanced excitability in response to paired-pulse stimulations. Whole-cell voltage clamp recordings revealed a significant increase in the frequency of spontaneous inhibitory postsynaptic currents onto PCs. In contrast, excitatory drive from evoked synaptic transmission was reduced while that of inhibitory synaptic transmission was increased. Current clamp recordings showed increase excitability in several sub- and threshold membrane properties that correlated with an increase in voltage-gated Na+ current. Our data suggest that, in addition to cell-autonomous disruption in PVIs, loss of Arx postnatal transcriptional activity in PVIs led to complex dysfunctions in PCs in CA1 microcircuits. These non-cell autonomous effects are likely the product of breakdown in feedback and/or feedforward processes and should be considered as fundamental contributors to the circuit mechanisms of NDDs such as Arx-linked early-onset epileptic encephalopathies.
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Affiliation(s)
- Donald J Joseph
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Markus Von Deimling
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Urology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rashmi Risbud
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Almedia J McCoy
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Eric D Marsh
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Koh B, Kim YE, Park SB, Kim SS, Lee J, Jo JH, Lee K, Bae DH, Kim TY, Cho SH, Bae MA, Kang D, Kim KY. Unraveling the Molecular Landscape of SCN1A Gene Knockout in Cerebral Organoids: A Multiomics Approach Utilizing Proteomics, Lipidomics, and Transcriptomics. ACS OMEGA 2024; 9:39804-39816. [PMID: 39346820 PMCID: PMC11425820 DOI: 10.1021/acsomega.4c05039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 08/29/2024] [Accepted: 09/05/2024] [Indexed: 10/01/2024]
Abstract
This study investigates the impact of sodium channel protein type 1 subunit alpha (SCN1A) gene knockout (SCN1A KO) on brain development and function using cerebral organoids coupled with a multiomics approach. From comprehensive omics analyses, we found that SCN1A KO organoids exhibit decreased growth, dysregulated neurotransmitter levels, and altered lipidomic, proteomic, and transcriptomic profiles compared to controls under matrix-free differentiation conditions. Neurochemical analysis reveals reduced levels of key neurotransmitters, and lipidomic analysis highlights changes in ether phospholipids and sphingomyelin. Furthermore, quantitative profiling of the SCN1A KO organoid proteome shows perturbations in cholesterol metabolism and sodium ion transportation, potentially affecting synaptic transmission. These findings suggest dysregulation of cholesterol metabolism and sodium ion transport, with implications for synaptic transmission. Overall, these insights shed light on the molecular mechanisms underlying SCN1A-associated disorders, such as Dravet syndrome, and offer potential avenues for therapeutic intervention.
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Affiliation(s)
- Byumseok Koh
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Young Eun Kim
- Group for Biometrology, Korea Research Institute of Standards and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
- School of Earth Sciences & Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Sung Bum Park
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Seong Soon Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Jangjae Lee
- Chemical Platform Technology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
- Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jeong Hyeon Jo
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
- Graduate School of New Drug Discovery and Development, Chungnam National University, Daejeon 34134, Republic of Korea
| | - KyungJin Lee
- Department of Microbiology, CHA University School of Medicine, 335 Pangyo-ro, Seongnam 13488, Republic of Korea
- ORGANOIDSCIENCES, 335 Pangyo-ro, Seongnam 13488, Republic of Korea
| | - Dong Hyuck Bae
- Department of Microbiology, CHA University School of Medicine, 335 Pangyo-ro, Seongnam 13488, Republic of Korea
| | - Tae-Young Kim
- School of Earth Sciences & Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Sung-Hee Cho
- Chemical Platform Technology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Myung Ae Bae
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Dukjin Kang
- Group for Biometrology, Korea Research Institute of Standards and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Ki Young Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon 34114, Republic of Korea
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Potesta CV, Cargile MS, Yan A, Xiong S, Macdonald RL, Gallagher MJ, Zhou C. Preoptic area controls sleep-related seizure onset in a genetic epilepsy mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.24.568593. [PMID: 39314442 PMCID: PMC11418963 DOI: 10.1101/2023.11.24.568593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
In genetic and refractory epileptic patients, seizure activity exhibits sleep-related modulation/regulation and sleep and seizure are intermingled. In this study, by using one het Gabrg2 Q390X KI mice as a genetic epilepsy model and optogenetic method in vivo, we found that subcortical POA neurons were active within epileptic network from the het Gabrg2 Q390X KI mice and the POA activity preceded epileptic (poly)spike-wave discharges(SWD/PSDs) in the het Gabrg2 Q390X KI mice. Meanwhile, as expected, the manipulating of the POA activity relatively altered NREM sleep and wake periods in both wt and the het Gabrg2 Q390X KI mice. Most importantly, the short activation of epileptic cortical neurons alone did not effectively trigger seizure activity in the het Gabrg2 Q390X KI mice. In contrast, compared to the wt mice, combined the POA nucleus activation and short activation of the epileptic cortical neurons effectively triggered or suppressed epileptic activity in the het Gabrg2 Q390X KI mice, indicating that the POA activity can control the brain state to trigger seizure incidence in the het Gabrg2 Q390X KI mice in vivo. In addition, the suppression of POA nucleus activity decreased myoclonic jerks in the Gabrg2 Q390X KI mice. Overall, this study discloses an operational mechanism for sleep-dependent seizure incidence in the genetic epilepsy model with the implications for refractory epilepsy. This operational mechanism also underlies myoclonic jerk generation, further with translational implications in seizure treatment for genetic/refractory epileptic patients and with contribution to memory/cognitive deficits in epileptic patients.
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Affiliation(s)
| | | | | | | | - Robert L. Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Martin J. Gallagher
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Brain Institute and Neuroscience graduate program, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Brain Institute and Neuroscience graduate program, Vanderbilt University Medical Center, Nashville, TN 37232
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5
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Barker-Haliski M, Hawkins NA. Innovative drug discovery strategies in epilepsy: integrating next-generation syndrome-specific mouse models to address pharmacoresistance and epileptogenesis. Expert Opin Drug Discov 2024; 19:1099-1113. [PMID: 39075876 PMCID: PMC11390315 DOI: 10.1080/17460441.2024.2384455] [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: 05/30/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024]
Abstract
INTRODUCTION Although there are numerous treatment options already available for epilepsy, over 30% of patients remain resistant to these antiseizure medications (ASMs). Historically, ASM discovery has relied on the demonstration of efficacy through the use of 'traditional' acute in vivo seizure models (e.g. maximal electroshock, subcutaneous pentylenetetrazol, and kindling). However, advances in genetic sequencing technologies and remaining medical needs for people with treatment-resistant epilepsy or special patient populations have encouraged recent efforts to identify novel compounds in syndrome-specific models of epilepsy. Syndrome-specific models, including Scn1a variant models of Dravet syndrome and APP/PS1 mice associated with familial early-onset Alzheimer's disease, have already led to the discovery of two mechanistically novel treatments for developmental and epileptic encephalopathies (DEEs), namely cannabidiol and soticlestat, respectively. AREAS COVERED In this review, the authors discuss how it is likely that next-generation drug discovery efforts for epilepsy will more comprehensively integrate syndrome-specific epilepsy models into early drug discovery providing the reader with their expert perspectives. EXPERT OPINION The percentage of patients with pharmacoresistant epilepsy has remained unchanged despite over 30 marketed ASMs. Consequently, there is a high unmet need to reinvent and revise discovery strategies to more effectively address the remaining needs of patients with specific epilepsy syndromes, including drug-resistant epilepsy and DEEs.
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Affiliation(s)
| | - Nicole A Hawkins
- Feinberg School of Medicine Chicago, Northwestern University, Chicago, IL, USA
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Hawkins NA, Speakes N, Kearney JA. Fine mapping and candidate gene analysis of Dravet syndrome modifier loci on mouse chromosomes 7 and 8. Mamm Genome 2024; 35:334-345. [PMID: 38862622 PMCID: PMC11329421 DOI: 10.1007/s00335-024-10046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 05/21/2024] [Indexed: 06/13/2024]
Abstract
Dravet syndrome is a developmental and epileptic encephalopathy (DEE) characterized by intractable seizures, comorbidities related to developmental, cognitive, and motor delays, and a high mortality burden due to sudden unexpected death in epilepsy (SUDEP). Most Dravet syndrome cases are attributed to SCN1A haploinsufficiency, with genetic modifiers and environmental factors influencing disease severity. Mouse models with heterozygous deletion of Scn1a recapitulate key features of Dravet syndrome, including seizures and premature mortality; however, severity varies depending on genetic background. Here, we refined two Dravet survival modifier (Dsm) loci, Dsm2 on chromosome 7 and Dsm3 on chromosome 8, using interval-specific congenic (ISC) mapping. Dsm2 was complex and encompassed at least two separate loci, while Dsm3 was refined to a single locus. Candidate modifier genes within these refined loci were prioritized based on brain expression, strain-dependent differences, and biological relevance to seizures or epilepsy. High priority candidate genes for Dsm2 include Nav2, Ptpn5, Ldha, Dbx1, Prmt3 and Slc6a5, while Dsm3 has a single high priority candidate, Psd3. This study underscores the complex genetic architecture underlying Dravet syndrome and provides insights into potential modifier genes that could influence disease severity and serve as novel therapeutic targets.
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Affiliation(s)
- Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Nathan Speakes
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA.
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7
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Howard MA. New complex physiological findings evolve hypothesized mechanisms of Dravet syndrome. Neural Regen Res 2024; 19:1867-1868. [PMID: 38227502 DOI: 10.4103/1673-5374.390967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/09/2023] [Indexed: 01/17/2024] Open
Affiliation(s)
- MacKenzie A Howard
- Department of Neurology, Dell Medical School, Austin, TX, USA Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
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Espino CM, Nagaraja C, Ortiz S, Dayton JR, Murali AR, Ma Y, Mann EL, Garlapalli S, Wohlgemuth RP, Brashear SE, Smith LR, Wilkinson KA, Griffith TN. Differential encoding of mammalian proprioception by voltage-gated sodium channels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.27.609982. [PMID: 39253497 PMCID: PMC11383322 DOI: 10.1101/2024.08.27.609982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
Animals that require purposeful movement for survival are endowed with mechanosensory neurons called proprioceptors that provide essential sensory feedback from muscles and joints to spinal cord circuits, which modulates motor output. Despite the essential nature of proprioceptive signaling in daily life, the mechanisms governing proprioceptor activity are poorly understood. Here, we have identified distinct and nonredundant roles for two voltage-gated sodium channels (NaVs), NaV1.1 and NaV1.6, in mammalian proprioception. Deletion of NaV1.6 in somatosensory neurons (NaV1.6cKO mice) causes severe motor deficits accompanied by complete loss of proprioceptive transmission, which contrasts with our previous findings using similar mouse models to target NaV1.1 (NaV1.1cKO). In NaV1.6cKO animals, loss of proprioceptive feedback caused non-cell-autonomous impairments in proprioceptor end-organs and skeletal muscle that were absent in NaV1.1cKO mice. We attribute the differential contribution of NaV1.1 and NaV1.6 in proprioceptor function to distinct cellular localization patterns. Collectively, these data provide the first evidence that NaV subtypes uniquely shape neurotransmission within a somatosensory modality.
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Affiliation(s)
- Cyrrus M Espino
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
| | - Chetan Nagaraja
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
| | - Serena Ortiz
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Jacquelyn R Dayton
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
| | - Akash R Murali
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
- Undergraduate Program in Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Yanki Ma
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
- Undergraduate Program in Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Emari L Mann
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
- Postbaccalaureate Research Education Program at UC Davis, University of California, Davis, Davis, CA, USA
| | - Snigdha Garlapalli
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
- Undergraduate Program in Psychology, University of California, Davis, Davis, CA, USA
| | - Ross P Wohlgemuth
- Department of Physiology, Neurobiology, and Behavior, University of California, Davis, Davis, CA, USA
| | - Sarah E Brashear
- Department of Physiology, Neurobiology, and Behavior, University of California, Davis, Davis, CA, USA
| | - Lucas R Smith
- Department of Physiology, Neurobiology, and Behavior, University of California, Davis, Davis, CA, USA
| | | | - Theanne N Griffith
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, USA
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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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Lin S, Gade AR, Wang HG, Niemeyer JE, Galante A, DiStefano I, Towers P, Nunez J, Matsui M, Schwartz TH, Rajadhyaksha AM, Pitt GS. Interneuron FGF13 regulates seizure susceptibility via a sodium channel-independent mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590019. [PMID: 38659789 PMCID: PMC11042350 DOI: 10.1101/2024.04.18.590019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Developmental and Epileptic Encephalopathies (DEEs), a class of devastating neurological disorders characterized by recurrent seizures and exacerbated by disruptions to excitatory/inhibitory balance in the brain, are commonly caused by mutations in ion channels. Disruption of, or variants in, FGF13 were implicated as causal for a set of DEEs, but the underlying mechanisms were clouded because FGF13 is expressed in both excitatory and inhibitory neurons, FGF13 undergoes extensive alternative splicing producing multiple isoforms with distinct functions, and the overall roles of FGF13 in neurons are incompletely cataloged. To overcome these challenges, we generated a set of novel cell type-specific conditional knockout mice. Interneuron-targeted deletion of Fgf13 led to perinatal mortality associated with extensive seizures and impaired the hippocampal inhibitory/excitatory balance while excitatory neuron-targeted deletion of Fgf13 caused no detectable seizures and no survival deficits. While best studied as a voltage-gated sodium channel (Na v ) regulator, we observed no effect of Fgf13 ablation in interneurons on Na v s but rather a marked reduction in K + channel currents. Re-expressing different Fgf13 splice isoforms could partially rescue deficits in interneuron excitability and restore K + channel current amplitude. These results enhance our understanding of the molecular mechanisms that drive the pathogenesis of Fgf13- related seizures and expand our understanding of FGF13 functions in different neuron subsets.
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Shore AN, Li K, Safari M, Qunies AM, Spitznagel BD, Weaver CD, Emmitte KA, Frankel WN, Weston MC. Heterozygous expression of a Kcnt1 gain-of-function variant has differential effects on SST- and PV-expressing cortical GABAergic neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.11.561953. [PMID: 37873369 PMCID: PMC10592778 DOI: 10.1101/2023.10.11.561953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
More than twenty recurrent missense gain-of-function (GOF) mutations have been identified in the sodium-activated potassium (KNa) channel gene KCNT1 in patients with severe developmental and epileptic encephalopathies (DEEs), most of which are resistant to current therapies. Defining the neuron types most vulnerable to KCNT1 GOF will advance our understanding of disease mechanisms and provide refined targets for precision therapy efforts. Here, we assessed the effects of heterozygous expression of a Kcnt1 GOF variant (Y777H) on KNa currents and neuronal physiology among cortical glutamatergic and GABAergic neurons in mice, including those expressing vasoactive intestinal polypeptide (VIP), somatostatin (SST), and parvalbumin (PV), to identify and model the pathogenic mechanisms of autosomal dominant KCNT1 GOF variants in DEEs. Although the Kcnt1-Y777H variant had no effects on glutamatergic or VIP neuron function, it increased subthreshold KNa currents in both SST and PV neurons but with opposite effects on neuronal output; SST neurons became hypoexcitable with a higher rheobase current and lower action potential (AP) firing frequency, whereas PV neurons became hyperexcitable with a lower rheobase current and higher AP firing frequency. Further neurophysiological and computational modeling experiments showed that the differential effects of the Y777H variant on SST and PV neurons are not likely due to inherent differences in these neuron types, but to an increased persistent sodium current in PV, but not SST, neurons. The Y777H variant also increased excitatory input onto, and chemical and electrical synaptic connectivity between, SST neurons. Together, these data suggest differential pathogenic mechanisms, both direct and compensatory, contribute to disease phenotypes, and provide a salient example of how a pathogenic ion channel variant can cause opposite functional effects in closely related neuron subtypes due to interactions with other ionic conductances.
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Affiliation(s)
- Amy N. Shore
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Department of Neurological Sciences, University of Vermont, Burlington, VT, USA
| | - Keyong Li
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
| | - Mona Safari
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Translational Biology, Medicine, and Health Graduate Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Alshaima’a M. Qunies
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
- School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Brittany D. Spitznagel
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Kyle A. Emmitte
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Wayne N. Frankel
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
| | - Matthew C. Weston
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Department of Neurological Sciences, University of Vermont, Burlington, VT, USA
- Translational Biology, Medicine, and Health Graduate Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
- School of Neuroscience, Virginia Tech, Blacksburg, VA, USA
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12
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Johnson JP, Focken T, Karimi Tari P, Dube C, Goodchild SJ, Andrez JC, Bankar G, Burford K, Chang E, Chowdhury S, Christabel J, Dean R, de Boer G, Dehnhardt C, Gong W, Grimwood M, Hussainkhel A, Jia Q, Khakh K, Lee S, Li J, Lin S, Lindgren A, Lofstrand V, Mezeyova J, Nelkenbrecher K, Shuart NG, Sojo L, Sun S, Waldbrook M, Wesolowski S, Wilson M, Xie Z, Zenova A, Zhang W, Scott FL, Cutts AJ, Sherrington RP, Winquist R, Cohen CJ, Empfield JR. The contribution of Na V1.6 to the efficacy of voltage-gated sodium channel inhibitors in wild type and Na V1.6 gain-of-function (GOF) mouse seizure control. Br J Pharmacol 2024. [PMID: 38922847 DOI: 10.1111/bph.16481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/19/2024] [Accepted: 05/15/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND AND PURPOSE Inhibitors of voltage-gated sodium channels (NaVs) are important anti-epileptic drugs, but the contribution of specific channel isoforms is unknown since available inhibitors are non-selective. We aimed to create novel, isoform selective inhibitors of Nav channels as a means of informing the development of improved antiseizure drugs. EXPERIMENTAL APPROACH We created a series of compounds with diverse selectivity profiles enabling block of NaV1.6 alone or together with NaV1.2. These novel NaV inhibitors were evaluated for their ability to inhibit electrically evoked seizures in mice with a heterozygous gain-of-function mutation (N1768D/+) in Scn8a (encoding NaV1.6) and in wild-type mice. KEY RESULTS Pharmacologic inhibition of NaV1.6 in Scn8aN1768D/+ mice prevented seizures evoked by a 6-Hz shock. Inhibitors were also effective in a direct current maximal electroshock seizure assay in wild-type mice. NaV1.6 inhibition correlated with efficacy in both models, even without inhibition of other CNS NaV isoforms. CONCLUSIONS AND IMPLICATIONS Our data suggest NaV1.6 inhibition is a driver of efficacy for NaV inhibitor anti-seizure medicines. Sparing the NaV1.1 channels of inhibitory interneurons did not compromise efficacy. Selective NaV1.6 inhibitors may provide targeted therapies for human Scn8a developmental and epileptic encephalopathies and improved treatments for idiopathic epilepsies.
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Affiliation(s)
- James P Johnson
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Thilo Focken
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Parisa Karimi Tari
- Department of In Vivo Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Celine Dube
- Department of In Vivo Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Samuel J Goodchild
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | | | - Girish Bankar
- Department of In Vivo Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Kristen Burford
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Elaine Chang
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Sultan Chowdhury
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Jessica Christabel
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Richard Dean
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Gina de Boer
- Department of Compound Properties, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Christoph Dehnhardt
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Wei Gong
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Michael Grimwood
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Angela Hussainkhel
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Qi Jia
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Kuldip Khakh
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Stephanie Lee
- Department of Compound Properties, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Jenny Li
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Sophia Lin
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Andrea Lindgren
- Department of Compound Properties, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Verner Lofstrand
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Janette Mezeyova
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Karen Nelkenbrecher
- Department of In Vivo Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Noah Gregory Shuart
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Luis Sojo
- Department of Compound Properties, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Shaoyi Sun
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Matthew Waldbrook
- Department of In Vivo Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Steven Wesolowski
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Michael Wilson
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Zhiwei Xie
- Department of In Vitro Biology, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Alla Zenova
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Wei Zhang
- Department of Chemistry, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | | | - Alison J Cutts
- Scientific Affairs, Xenon Pharmaceuticals, Inc, Burnaby, British Columbia, Canada
| | - Robin P Sherrington
- Executive Team, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Raymond Winquist
- Executive Team, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - Charles J Cohen
- Executive Team, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
| | - James R Empfield
- Executive Team, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada
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13
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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 PMCID: PMC11390705 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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14
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Capitano F, Kuchenbuch M, Lavigne J, Chaptoukaev H, Zuluaga MA, Lorenzi M, Nabbout R, Mantegazza M. Preictal dysfunctions of inhibitory interneurons paradoxically lead to their rebound hyperactivity and to low-voltage-fast onset seizures in Dravet syndrome. Proc Natl Acad Sci U S A 2024; 121:e2316364121. [PMID: 38809712 PMCID: PMC11161744 DOI: 10.1073/pnas.2316364121] [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: 09/26/2023] [Accepted: 05/01/2024] [Indexed: 05/31/2024] Open
Abstract
Epilepsies have numerous specific mechanisms. The understanding of neural dynamics leading to seizures is important for disclosing pathological mechanisms and developing therapeutic approaches. We investigated electrographic activities and neural dynamics leading to convulsive seizures in patients and mouse models of Dravet syndrome (DS), a developmental and epileptic encephalopathy in which hypoexcitability of GABAergic neurons is considered to be the main dysfunction. We analyzed EEGs from DS patients carrying a SCN1A pathogenic variant, as well as epidural electrocorticograms, hippocampal local field potentials, and hippocampal single-unit neuronal activities in Scn1a+/- and Scn1aRH/+ DS mice. Strikingly, most seizures had low-voltage-fast onset in both patients and mice, which is thought to be generated by hyperactivity of GABAergic interneurons, the opposite of the main pathological mechanism of DS. Analyzing single-unit recordings, we observed that temporal disorganization of the firing of putative interneurons in the period immediately before the seizure (preictal) precedes the increase of their activity at seizure onset, together with the entire neuronal network. Moreover, we found early signatures of the preictal period in the spectral features of hippocampal and cortical field potential of Scn1a mice and of patients' EEG, which are consistent with the dysfunctions that we observed in single neurons and that allowed seizure prediction. Therefore, the perturbed preictal activity of interneurons leads to their hyperactivity at the onset of generalized seizures, which have low-voltage-fast features that are similar to those observed in other epilepsies and are triggered by hyperactivity of GABAergic neurons. Preictal spectral features may be used as predictive seizure biomarkers.
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Affiliation(s)
- Fabrizio Capitano
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
| | - Mathieu Kuchenbuch
- Reference Centre for Rare Epilepsies, Member of European Reference Network EpiCARE, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris75015, France
- Laboratory of Translational Research for Neurological Disorders, Inserm UMR 1163, Imagine Institute, Université Paris Cité, Paris75015, France
| | - Jennifer Lavigne
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
| | | | | | - Marco Lorenzi
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- Epione Research team, Inria Center of Université Côte d’Azur, Biot-Sophia Antipolis06410, France
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Member of European Reference Network EpiCARE, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris75015, France
- Laboratory of Translational Research for Neurological Disorders, Inserm UMR 1163, Imagine Institute, Université Paris Cité, Paris75015, France
| | - Massimo Mantegazza
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
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15
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Guo J, Min D, Farrell EK, Zhou Y, Faingold CL, Cotten JF, Feng HJ. Enhancing the action of serotonin by three different mechanisms prevents spontaneous seizure-induced mortality in Dravet mice. Epilepsia 2024; 65:1791-1800. [PMID: 38593237 PMCID: PMC11166528 DOI: 10.1111/epi.17966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is an underestimated complication of epilepsy. Previous studies have demonstrated that enhancement of serotonergic neurotransmission suppresses seizure-induced sudden death in evoked seizure models. However, it is unclear whether elevated serotonin (5-HT) function will prevent spontaneous seizure-induced mortality (SSIM), which is characteristic of human SUDEP. We examined the effects of 5-HT-enhancing agents that act by three different pharmacological mechanisms on SSIM in Dravet mice, which exhibit a high incidence of SUDEP, modeling human Dravet syndrome. METHODS Dravet mice of both sexes were evaluated for spontaneous seizure characterization and changes in SSIM incidence induced by agents that enhance 5-HT-mediated neurotransmission. Fluoxetine (a selective 5-HT reuptake inhibitor), fenfluramine (a 5-HT releaser and agonist), SR 57227 (a specific 5-HT3 receptor agonist), or saline (vehicle) was intraperitoneally administered over an 8-day period in Dravet mice, and the effect of these treatments on SSIM was examined. RESULTS Spontaneous seizures in Dravet mice generally progressed from wild running to tonic seizures with or without SSIM. Fluoxetine at 30 mg/kg, but not at 20 or 5 mg/kg, significantly reduced SSIM compared with the vehicle control. Fenfluramine at 1-10 mg/kg, but not .2 mg/kg, fully protected Dravet mice from SSIM, with all mice surviving. Compared with the vehicle control, SR 57227 at 20 mg/kg, but not at 10 or 5 mg/kg, significantly lowered SSIM. The effect of these drugs on SSIM was independent of sex. SIGNIFICANCE Our data demonstrate that elevating serotonergic function by fluoxetine, fenfluramine, or SR 57227 significantly reduces or eliminates SSIM in Dravet mice in a sex-independent manner. These findings suggest that deficits in serotonergic neurotransmission likely play an important role in the pathogenesis of SSIM, and fluoxetine and fenfluramine, which are US Food and Drug Administration-approved medications, may potentially prevent SUDEP in at-risk patients.
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Affiliation(s)
- Jialing Guo
- National Health Commission Key Laboratory of Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
| | - Daniel Min
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Emory K. Farrell
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Yupeng Zhou
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Carl L. Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Joseph F. Cotten
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Anesthesia, Harvard Medical School, Boston, MA, USA
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16
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Zalaquett NG, Salameh E, Kim JM, Ghanbarian E, Tawk K, Abouzari M. The Dawn and Advancement of the Knowledge of the Genetics of Migraine. J Clin Med 2024; 13:2701. [PMID: 38731230 PMCID: PMC11084801 DOI: 10.3390/jcm13092701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
Background: Migraine is a prevalent episodic brain disorder known for recurrent attacks of unilateral headaches, accompanied by complaints of photophobia, phonophobia, nausea, and vomiting. Two main categories of migraine are migraine with aura (MA) and migraine without aura (MO). Main body: Early twin and population studies have shown a genetic basis for these disorders, and efforts have been invested since to discern the genes involved. Many techniques, including candidate-gene association studies, loci linkage studies, genome-wide association, and transcription studies, have been used for this goal. As a result, several genes were pinned with concurrent and conflicting data among studies. It is important to understand the evolution of techniques and their findings. Conclusions: This review provides a chronological understanding of the different techniques used from the dawn of migraine genetic investigations and the genes linked with the migraine subtypes.
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Affiliation(s)
- Nader G. Zalaquett
- Faculty of Medicine, American University of Beirut, Beirut 1107, Lebanon
| | - Elio Salameh
- Faculty of Medicine, American University of Beirut, Beirut 1107, Lebanon
| | - Jonathan M. Kim
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, CA 92697, USA
| | - Elham Ghanbarian
- Department of Neurology, University of California, Irvine, CA 92617, USA
| | - Karen Tawk
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, CA 92697, USA
| | - Mehdi Abouzari
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, CA 92697, USA
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17
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Spoleti E, La Barbera L, Cauzzi E, De Paolis ML, Saba L, Marino R, Sciamanna G, Di Lazzaro V, Keller F, Nobili A, Krashia P, D'Amelio M. Dopamine neuron degeneration in the Ventral Tegmental Area causes hippocampal hyperexcitability in experimental Alzheimer's Disease. Mol Psychiatry 2024; 29:1265-1280. [PMID: 38228889 PMCID: PMC11189820 DOI: 10.1038/s41380-024-02408-9] [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: 07/28/2023] [Revised: 12/17/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024]
Abstract
Early and progressive dysfunctions of the dopaminergic system from the Ventral Tegmental Area (VTA) have been described in Alzheimer's Disease (AD). During the long pre-symptomatic phase, alterations in the function of Parvalbumin interneurons (PV-INs) are also observed, resulting in cortical hyperexcitability represented by subclinical epilepsy and aberrant gamma-oscillations. However, it is unknown whether the dopaminergic deficits contribute to brain hyperexcitability in AD. Here, using the Tg2576 mouse model of AD, we prove that reduced hippocampal dopaminergic innervation, due to VTA dopamine neuron degeneration, impairs PV-IN firing and gamma-waves, weakens the inhibition of pyramidal neurons and induces hippocampal hyperexcitability via lower D2-receptor-mediated activation of the CREB-pathway. These alterations coincide with reduced PV-IN numbers and Perineuronal Net density. Importantly, L-DOPA and the selective D2-receptor agonist quinpirole rescue p-CREB levels and improve the PV-IN-mediated inhibition, thus reducing hyperexcitability. Moreover, similarly to quinpirole, sumanirole - another D2-receptor agonist and a known anticonvulsant - not only increases p-CREB levels in PV-INs but also restores gamma-oscillations in Tg2576 mice. Conversely, blocking the dopaminergic transmission with sulpiride (a D2-like receptor antagonist) in WT mice reduces p-CREB levels in PV-INs, mimicking what occurs in Tg2576. Overall, these findings support the hypothesis that the VTA dopaminergic system integrity plays a key role in hippocampal PV-IN function and survival, disclosing a relevant contribution of the reduced dopaminergic tone to aberrant gamma-waves, hippocampal hyperexcitability and epileptiform activity in early AD.
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Affiliation(s)
- Elena Spoleti
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
| | - Livia La Barbera
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
| | - Emma Cauzzi
- Department of Systems Medicine, University of Rome Tor Vergata, 00133, Rome, Italy
| | - Maria Luisa De Paolis
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
| | - Luana Saba
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
| | - Ramona Marino
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
| | - Giuseppe Sciamanna
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
- UniCamillus International University of Health Sciences, 00131, Rome, Italy
| | - Vincenzo Di Lazzaro
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
- Operative Research Unit of Neurology, Fondazione Policlinico Universitario Campus Bio-Medico, 00128, Rome, Italy
| | - Flavio Keller
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
| | - Annalisa Nobili
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
| | - Paraskevi Krashia
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
- Department of Sciences and Technologies for Sustainable Development and One Health, Università Campus Bio-Medico di Roma, 00128, Rome, Italy
| | - Marcello D'Amelio
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, 00128, Rome, Italy.
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, 00143, Rome, Italy.
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18
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Olkhova EA, Smith LA, Dennis BH, Ng YS, LeBeau FEN, Gorman GS. Delineating mechanisms underlying parvalbumin neuron impairment in different neurological and neurodegenerative disorders: the emerging role of mitochondrial dysfunction. Biochem Soc Trans 2024; 52:553-565. [PMID: 38563502 PMCID: PMC11088917 DOI: 10.1042/bst20230191] [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: 11/21/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024]
Abstract
Given the current paucity of effective treatments in many neurological disorders, delineating pathophysiological mechanisms among the major psychiatric and neurodegenerative diseases may fuel the development of novel, potent treatments that target shared pathways. Recent evidence suggests that various pathological processes, including bioenergetic failure in mitochondria, can perturb the function of fast-spiking, parvalbumin-positive neurons (PV+). These inhibitory neurons critically influence local circuit regulation, the generation of neuronal network oscillations and complex brain functioning. Here, we survey PV+ cell vulnerability in the major neuropsychiatric, and neurodegenerative diseases and review associated cellular and molecular pathophysiological alterations purported to underlie disease aetiology.
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Affiliation(s)
- Elizaveta A. Olkhova
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Laura A. Smith
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Bethany H. Dennis
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, U.K
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Fiona E. N. LeBeau
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Gráinne S. Gorman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, U.K
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
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19
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Hawkins NA, Speakes N, Kearney JA. Fine Mapping and Candidate Gene Analysis of Dravet Syndrome Modifier Loci on Mouse Chromosomes 7 and 8. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589561. [PMID: 38659879 PMCID: PMC11042286 DOI: 10.1101/2024.04.15.589561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Dravet syndrome is a developmental and epileptic encephalopathy (DEE) characterized by intractable seizures, comorbidities related to developmental, cognitive, and motor delays, and a high mortality burden due to sudden unexpected death in epilepsy (SUDEP). Most Dravet syndrome cases are attributed to SCN1A haploinsufficiency, with genetic modifiers and environmental factors influencing disease severity. Mouse models with heterozygous deletion of Scn1a recapitulate key features of Dravet syndrome, including seizures and premature mortality; however, severity varies depending on genetic background. Here, we refined two Dravet survival modifier (Dsm) loci, Dsm2 on chromosome 7 and Dsm3 on chromosome 8, using interval-specific congenic (ISC) mapping. Dsm2 was complex and encompassed at least two separate loci, while Dsm3 was refined to a single locus. Candidate modifier genes within these refined loci were prioritized based on brain expression, strain-dependent differences, and biological relevance to seizures or epilepsy. High priority candidate genes for Dsm2 include Nav2, Ptpn5, Ldha, Dbx1, Prmt3 and Slc6a5, while Dsm3 has a single high priority candidate, Psd3. This study underscores the complex genetic architecture underlying Dravet syndrome and provides insights into potential modifier genes that could influence disease severity and serve as novel therapeutic targets.
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Affiliation(s)
- Nicole A. Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
| | - Nathan Speakes
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
| | - Jennifer A. Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
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20
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Lee SH, Kang YJ, Smith BN. Activation of hypoactive parvalbumin-positive fast-spiking interneuron restores dentate inhibition to prevent epileptiform activity in the mouse intrahippocampal kainate model of temporal lobe epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.05.588316. [PMID: 38645248 PMCID: PMC11030452 DOI: 10.1101/2024.04.05.588316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Parvalbumin-positive (PV+) GABAergic interneurons in the dentate gyrus provide powerful perisomatic inhibition of dentate granule cells (DGCs) to prevent overexcitation and maintain the stability of dentate gyrus circuits. Most dentate PV+ interneurons survive status epilepticus, but surviving PV+ interneuron mediated inhibition is compromised in the dentate gyrus shortly after status epilepticus, contributing to epileptogenesis in temporal lobe epilepsy. It is uncertain whether the impaired activity of dentate PV+ interneurons recovers at later times or if it continues for months following status epilepticus. The development of compensatory modifications related to PV+ interneuron circuits in the months following status epilepticus is unknown, although reduced dentate GABAergic inhibition persists long after status epilepticus. We employed PV immunostaining and whole-cell patch-clamp recordings from dentate PV+ interneurons and DGCs in slices from male and female sham controls and intrahippocampal kainate (IHK) treated mice that developed spontaneous seizures months after status epilepticus to study epilepsy-associated changes in dentate PV+ interneuron circuits. We found that the number of dentate PV+ cells was reduced in IHK treated mice. Electrical recordings showed that: 1) Action potential firing rates of dentate PV+ interneurons were reduced in IHK treated mice up to four months after status epilepticus; 2) Spontaneous inhibitory postsynaptic currents (sIPSCs) in DGCs exhibited reduced frequency but increased amplitude in IHK treated mice; and 3) The amplitude of evoked IPSCs in DGCs by optogenetic activation of dentate PV+ cells was upregulated without changes in short-term plasticity. Video-EEG recordings revealed that IHK treated mice showed spontaneous epileptiform activity in the dentate gyrus and that chemogenetic activation of PV+ interneurons abolished the epileptiform activity. Our results suggest not only that the compensatory changes in PV+ interneuron circuits develop after IHK treatment, but also that increased PV+ interneuron mediated inhibition in the dentate gyrus may compensate for cell loss and reduced intrinsic excitability of dentate PV+ interneurons to stop seizures in temporal lobe epilepsy. Highlights Reduced number of dentate PV+ interneurons in TLE micePersistently reduced action potential firing rates of dentate PV+ interneurons in TLE miceEnhanced amplitude but decreased frequency of spontaneous IPSCs in the dentate gyrus in TLE miceIncreased amplitude of evoked IPSCs mediated by dentate PV+ interneurons in TLE miceChemogenetic activation of PV+ interneurons prevents epileptiform activity in TLE mice.
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21
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Di Berardino C, Mainardi M, Brusco S, Benvenuto E, Broccoli V, Colasante G. Temporal manipulation of the Scn1a gene reveals its essential role in adult brain function. Brain 2024; 147:1216-1230. [PMID: 37812819 PMCID: PMC10994529 DOI: 10.1093/brain/awad350] [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: 05/23/2023] [Revised: 09/23/2023] [Accepted: 09/30/2023] [Indexed: 10/11/2023] Open
Abstract
Dravet syndrome is a severe epileptic encephalopathy, characterized by drug-resistant epilepsy, severe cognitive and behavioural deficits, with increased risk of sudden unexpected death (SUDEP). It is caused by haploinsufficiency of SCN1A gene encoding for the α-subunit of the voltage-gated sodium channel Nav1.1. Therapeutic approaches aiming to upregulate the healthy copy of SCN1A gene to restore its normal expression levels are being developed. However, whether Scn1a gene function is required only during a specific developmental time-window or, alternatively, if its physiological expression is necessary in adulthood is untested up to now. We induced Scn1a gene haploinsufficiency at two ages spanning postnatal brain development (P30 and P60) and compared the phenotypes of those mice to Scn1a perinatally induced mice (P2), recapitulating all deficits of Dravet mice. Induction of heterozygous Nav1.1 mutation at P30 and P60 elicited susceptibility to the development of both spontaneous and hyperthermia-induced seizures and SUDEP rates comparable to P2-induced mice, with symptom onset accompanied by the characteristic GABAergic interneuron dysfunction. Finally, delayed Scn1a haploinsufficiency induction provoked hyperactivity, anxiety and social attitude impairment at levels comparable to age matched P2-induced mice, while it was associated with a better cognitive performance, with P60-induced mice behaving like the control group. Our data show that maintenance of physiological levels of Nav1.1 during brain development is not sufficient to prevent Dravet symptoms and that long-lasting restoration of Scn1a gene expression would be required to grant optimal clinical benefit in patients with Dravet syndrome.
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Affiliation(s)
- Claudia Di Berardino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Martina Mainardi
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Simone Brusco
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129 Milan, Italy
| | - Elena Benvenuto
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Gene and Cell Therapy PhD Program, Vita- Salute San Raffaele University, 20132 Milan, Italy
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129 Milan, Italy
| | - Gaia Colasante
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
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22
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Yuan Y, Lopez-Santiago L, Denomme N, Chen C, O'Malley HA, Hodges SL, Ji S, Han Z, Christiansen A, Isom LL. Antisense oligonucleotides restore excitability, GABA signalling and sodium current density in a Dravet syndrome model. Brain 2024; 147:1231-1246. [PMID: 37812817 PMCID: PMC10994531 DOI: 10.1093/brain/awad349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/13/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
Dravet syndrome is an intractable developmental and epileptic encephalopathy caused by de novo variants in SCN1A resulting in haploinsufficiency of the voltage-gated sodium channel Nav1.1. We showed previously that administration of the antisense oligonucleotide STK-001, also called ASO-22, generated using targeted augmentation of nuclear gene output technology to prevent inclusion of the nonsense-mediated decay, or poison, exon 20N in human SCN1A, increased productive Scn1a transcript and Nav1.1 expression and reduced the incidence of electrographic seizures and sudden unexpected death in epilepsy in a mouse model of Dravet syndrome. Here, we investigated the mechanism of action of ASO-84, a surrogate for ASO-22 that also targets splicing of SCN1A exon 20N, in Scn1a+/- Dravet syndrome mouse brain. Scn1a +/- Dravet syndrome and wild-type mice received a single intracerebroventricular injection of antisense oligonucleotide or vehicle at postnatal Day 2. We examined the electrophysiological properties of cortical pyramidal neurons and parvalbumin-positive fast-spiking interneurons in brain slices at postnatal Days 21-25 and measured sodium currents in parvalbumin-positive interneurons acutely dissociated from postnatal Day 21-25 brain slices. We show that, in untreated Dravet syndrome mice, intrinsic cortical pyramidal neuron excitability was unchanged while cortical parvalbumin-positive interneurons showed biphasic excitability with initial hyperexcitability followed by hypoexcitability and depolarization block. Dravet syndrome parvalbumin-positive interneuron sodium current density was decreased compared to wild-type. GABAergic signalling to cortical pyramidal neurons was reduced in Dravet syndrome mice, suggesting decreased GABA release from interneurons. ASO-84 treatment restored action potential firing, sodium current density and GABAergic signalling in Dravet syndrome parvalbumin-positive interneurons. Our work suggests that interneuron excitability is selectively affected by ASO-84. This new work provides critical insights into the mechanism of action of this antisense oligonucleotide and supports the potential of antisense oligonucleotide-mediated upregulation of Nav1.1 as a successful strategy to treat Dravet syndrome.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luis Lopez-Santiago
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nicholas Denomme
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chunling Chen
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Heather A O'Malley
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Samantha L Hodges
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sophina Ji
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | - Zhou Han
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | | | - Lori L Isom
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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23
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Gallagher D, Pérez-Palma E, Bruenger T, Ghanty I, Brilstra E, Ceulemans B, Chemaly N, de Lange I, Depienne C, Guerrini R, Mei D, Møller RS, Nabbout R, Regan BM, Schneider AL, Scheffer IE, Schoonjans AS, Symonds JD, Weckhuysen S, Zuberi SM, Lal D, Brunklaus A. Genotype-phenotype associations in 1018 individuals with SCN1A-related epilepsies. Epilepsia 2024; 65:1046-1059. [PMID: 38410936 DOI: 10.1111/epi.17882] [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: 09/17/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE SCN1A variants are associated with epilepsy syndromes ranging from mild genetic epilepsy with febrile seizures plus (GEFS+) to severe Dravet syndrome (DS). Many variants are de novo, making early phenotype prediction difficult, and genotype-phenotype associations remain poorly understood. METHODS We assessed data from a retrospective cohort of 1018 individuals with SCN1A-related epilepsies. We explored relationships between variant characteristics (position, in silico prediction scores: Combined Annotation Dependent Depletion (CADD), Rare Exome Variant Ensemble Learner (REVEL), SCN1A genetic score), seizure characteristics, and epilepsy phenotype. RESULTS DS had earlier seizure onset than other GEFS+ phenotypes (5.3 vs. 12.0 months, p < .001). In silico variant scores were higher in DS versus GEFS+ (p < .001). Patients with missense variants in functionally important regions (conserved N-terminus, S4-S6) exhibited earlier seizure onset (6.0 vs. 7.0 months, p = .003) and were more likely to have DS (280/340); those with missense variants in nonconserved regions had later onset (10.0 vs. 7.0 months, p = .036) and were more likely to have GEFS+ (15/29, χ2 = 19.16, p < .001). A minority of protein-truncating variants were associated with GEFS+ (10/393) and more likely to be located in the proximal first and last exon coding regions than elsewhere in the gene (9.7% vs. 1.0%, p < .001). Carriers of the same missense variant exhibited less variability in age at seizure onset compared with carriers of different missense variants for both DS (1.9 vs. 2.9 months, p = .001) and GEFS+ (8.0 vs. 11.0 months, p = .043). Status epilepticus as presenting seizure type is a highly specific (95.2%) but nonsensitive (32.7%) feature of DS. SIGNIFICANCE Understanding genotype-phenotype associations in SCN1A-related epilepsies is critical for early diagnosis and management. We demonstrate an earlier disease onset in patients with missense variants in important functional regions, the occurrence of GEFS+ truncating variants, and the value of in silico prediction scores. Status epilepticus as initial seizure type is a highly specific, but not sensitive, early feature of DS.
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Affiliation(s)
- Declan Gallagher
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago, Chile
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Tobias Bruenger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Ismael Ghanty
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eva Brilstra
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Berten Ceulemans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Nicole Chemaly
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Iris de Lange
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Davide Mei
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Rikke S Møller
- Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Brigid M Regan
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Amy L Schneider
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia
| | - An-Sofie Schoonjans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB Center for Molecular Neurology, Antwerp, Belgium
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium
- Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Stanley Center for Psychiatric Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Neurology, McGovern Medical School, UTHealth Houston, Houston, Texas, USA
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
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24
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Alfayyadh MM, Maksemous N, Sutherland HG, Lea RA, Griffiths LR. Unravelling the Genetic Landscape of Hemiplegic Migraine: Exploring Innovative Strategies and Emerging Approaches. Genes (Basel) 2024; 15:443. [PMID: 38674378 PMCID: PMC11049430 DOI: 10.3390/genes15040443] [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: 03/12/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Migraine is a severe, debilitating neurovascular disorder. Hemiplegic migraine (HM) is a rare and debilitating neurological condition with a strong genetic basis. Sequencing technologies have improved the diagnosis and our understanding of the molecular pathophysiology of HM. Linkage analysis and sequencing studies in HM families have identified pathogenic variants in ion channels and related genes, including CACNA1A, ATP1A2, and SCN1A, that cause HM. However, approximately 75% of HM patients are negative for these mutations, indicating there are other genes involved in disease causation. In this review, we explored our current understanding of the genetics of HM. The evidence presented herein summarises the current knowledge of the genetics of HM, which can be expanded further to explain the remaining heritability of this debilitating condition. Innovative bioinformatics and computational strategies to cover the entire genetic spectrum of HM are also discussed in this review.
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Affiliation(s)
| | | | | | | | - Lyn R. Griffiths
- Centre for Genomics and Personalised Health, Genomics Research Centre, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia; (M.M.A.); (N.M.); (H.G.S.); (R.A.L.)
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25
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Goodchild SJ, Shuart NG, Williams AD, Ye W, Parrish RR, Soriano M, Thouta S, Mezeyova J, Waldbrook M, Dean R, Focken T, Ghovanloo MR, Ruben PC, Scott F, Cohen CJ, Empfield J, Johnson JP. Molecular Pharmacology of Selective Na V1.6 and Dual Na V1.6/Na V1.2 Channel Inhibitors that Suppress Excitatory Neuronal Activity Ex Vivo. ACS Chem Neurosci 2024; 15:1169-1184. [PMID: 38359277 PMCID: PMC10958515 DOI: 10.1021/acschemneuro.3c00757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/17/2024] Open
Abstract
Voltage-gated sodium channel (NaV) inhibitors are used to treat neurological disorders of hyperexcitability such as epilepsy. These drugs act by attenuating neuronal action potential firing to reduce excitability in the brain. However, all currently available NaV-targeting antiseizure medications nonselectively inhibit the brain channels NaV1.1, NaV1.2, and NaV1.6, which potentially limits the efficacy and therapeutic safety margins of these drugs. Here, we report on XPC-7724 and XPC-5462, which represent a new class of small molecule NaV-targeting compounds. These compounds specifically target inhibition of the NaV1.6 and NaV1.2 channels, which are abundantly expressed in excitatory pyramidal neurons. They have a > 100-fold molecular selectivity against NaV1.1 channels, which are predominantly expressed in inhibitory neurons. Sparing NaV1.1 preserves the inhibitory activity in the brain. These compounds bind to and stabilize the inactivated state of the channels thereby reducing the activity of excitatory neurons. They have higher potency, with longer residency times and slower off-rates, than the clinically used antiseizure medications carbamazepine and phenytoin. The neuronal selectivity of these compounds is demonstrated in brain slices by inhibition of firing in cortical excitatory pyramidal neurons, without impacting fast spiking inhibitory interneurons. XPC-5462 also suppresses epileptiform activity in an ex vivo brain slice seizure model, whereas XPC-7224 does not, suggesting a possible requirement of Nav1.2 inhibition in 0-Mg2+- or 4-AP-induced brain slice seizure models. The profiles of these compounds will facilitate pharmacological dissection of the physiological roles of NaV1.2 and NaV1.6 in neurons and help define the role of specific channels in disease states. This unique selectivity profile provides a new approach to potentially treat disorders of neuronal hyperexcitability by selectively downregulating excitatory circuits.
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Affiliation(s)
- Samuel J. Goodchild
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Noah Gregory Shuart
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Aaron D. Williams
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Wenlei Ye
- Neurocrine
Biosciences, San Diego, California 92130, United States
| | - R. Ryley Parrish
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Maegan Soriano
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Samrat Thouta
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Janette Mezeyova
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Matthew Waldbrook
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Richard Dean
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Thilo Focken
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - Mohammad-Reza Ghovanloo
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
- Department
of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department
of Neurology, Yale University, New Haven, Connecticut 06519, United States
| | - Peter C. Ruben
- Department
of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Fiona Scott
- Neurocrine
Biosciences, San Diego, California 92130, United States
| | - Charles J. Cohen
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - James Empfield
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
| | - JP Johnson
- Department
of Cellular and Molecular Biology, Xenon
Pharmaceuticals, Burnaby, BC V5G 4W8, Canada
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26
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Qiao YN, Li L, Hu SH, Yang YX, Ma ZZ, Huang L, An YP, Yuan YY, Lin Y, Xu W, Li Y, Lin PC, Cao J, Zhao JY, Zhao SM. Ketogenic diet-produced β-hydroxybutyric acid accumulates brain GABA and increases GABA/glutamate ratio to inhibit epilepsy. Cell Discov 2024; 10:17. [PMID: 38346975 PMCID: PMC10861483 DOI: 10.1038/s41421-023-00636-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 12/06/2023] [Indexed: 02/15/2024] Open
Abstract
Ketogenic diet (KD) alleviates refractory epilepsy and reduces seizures in children. However, the metabolic/cell biologic mechanisms by which the KD exerts its antiepileptic efficacy remain elusive. Herein, we report that KD-produced β-hydroxybutyric acid (BHB) augments brain gamma-aminobutyric acid (GABA) and the GABA/glutamate ratio to inhibit epilepsy. The KD ameliorated pentetrazol-induced epilepsy in mice. Mechanistically, KD-produced BHB, but not other ketone bodies, inhibited HDAC1/HDAC2, increased H3K27 acetylation, and transcriptionally upregulated SIRT4 and glutamate decarboxylase 1 (GAD1). BHB-induced SIRT4 de-carbamylated and inactivated glutamate dehydrogenase to preserve glutamate for GABA synthesis, and GAD1 upregulation increased mouse brain GABA/glutamate ratio to inhibit neuron excitation. BHB administration in mice inhibited epilepsy induced by pentetrazol. BHB-mediated relief of epilepsy required high GABA level and GABA/glutamate ratio. These results identified BHB as the major antiepileptic metabolite of the KD and suggested that BHB may serve as an alternative and less toxic antiepileptic agent than KD.
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Affiliation(s)
- Ya-Nan Qiao
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Lei Li
- Department of Anatomy, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Song-Hua Hu
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Yuan-Xin Yang
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Zhen-Zhen Ma
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Lin Huang
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Yan-Peng An
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Yi-Yuan Yuan
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Yan Lin
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Wei Xu
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Yao Li
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China
| | - Peng-Cheng Lin
- Key Laboratory for Tibet Plateau Phytochemistry of Qinghai Province, College of Pharmacy, Qinghai University for Nationalities, Xining, Qinghai, China
| | - Jing Cao
- Department of Anatomy, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Jian-Yuan Zhao
- Institute for Developmental and Regenerative Cardiovascular Medicine, MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shi-Min Zhao
- The Obstetrics & Gynaecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodelling and Health, Institutes of Biomedical Sciences, and Children's Hospital of Fudan University, Fudan University, Shanghai, China.
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Key Laboratory for Tibet Plateau Phytochemistry of Qinghai Province, College of Pharmacy, Qinghai University for Nationalities, Xining, Qinghai, China.
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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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28
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Witkowski G, Szulczyk B, Nurowska E, Jurek M, Pasierski M, Lipiec A, Charzewska A, Dawidziuk M, Milewski M, Owsiak S, Rola R, Sienkiewicz Jarosz H, Hoffman-Zacharska D. Functional Characteristics of the Nav1.1 p.Arg1596Cys Mutation Associated with Varying Severity of Epilepsy Phenotypes. Int J Mol Sci 2024; 25:1745. [PMID: 38339022 PMCID: PMC10855957 DOI: 10.3390/ijms25031745] [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: 12/29/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Mutations of the SCN1A gene, which encodes the voltage-dependent Na+ channel's α subunit, are associated with diverse epileptic syndromes ranging in severity, even intra-family, from febrile seizures to epileptic encephalopathy. The underlying cause of this variability is unknown, suggesting the involvement of additional factors. The aim of our study was to describe the properties of mutated channels and investigate genetic causes for clinical syndromes' variability in the family of five SCN1A gene p.Arg1596Cys mutation carriers. The analysis of additional genetic factors influencing SCN1A-associated phenotypes was conducted through exome sequencing (WES). To assess the impact of mutations, we used patch clamp analysis of mutated channels expressed in HEK cells and in vivo neural excitability studies (NESs). In cells expressing the mutant channel, sodium currents were reduced. NESs indicated increased excitability of peripheral motor neurons in mutation carriers. WES showed the absence of non-SCA1 pathogenic variants that could be causative of disease in the family. Variants of uncertain significance in three genes, as potential modifiers of the most severe phenotype, were identified. The p.Arg1596Cys substitution inhibits channel function, affecting steady-state inactivation kinetics. Its clinical manifestations involve not only epileptic symptoms but also increased excitability of peripheral motor fibers. The role of Nav1.1 in excitatory neurons cannot be ruled out as a significant factor of the clinical phenotype.
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Affiliation(s)
- Grzegorz Witkowski
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
- Military Institute of Aviation Medicine, Krasinskiego 54/56, 01-755 Warsaw, Poland;
| | - Bartlomiej Szulczyk
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Ewa Nurowska
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Marta Jurek
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Michal Pasierski
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Agata Lipiec
- Clinic of Pediatric Neurology, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland;
| | - Agnieszka Charzewska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Mateusz Dawidziuk
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Michal Milewski
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Szymon Owsiak
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
| | - Rafal Rola
- Military Institute of Aviation Medicine, Krasinskiego 54/56, 01-755 Warsaw, Poland;
| | - Halina Sienkiewicz Jarosz
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
| | - Dorota Hoffman-Zacharska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
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Krishna S, Fasaludeen A, Jose M, Banerjee M, Sundaram S, Radhakrishnan A, Menon RN. Impact of variant subtype on electro-clinical phenotype of Dravet syndrome- a South Indian cohort study. Seizure 2024; 115:81-86. [PMID: 38232648 DOI: 10.1016/j.seizure.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 01/19/2024] Open
Abstract
OBJECTIVE We aimed to compare the electroclinical correlates of truncating and missense variants of SCN1A variants in children with Dravet syndrome (DS) and to determine phenotypic features in relation to variants identified and seizure outcomes. METHODS A single center prospective study was carried out on a South Indian cohort. Patients below 18 years of age who met the clinical criteria for DS who had undergone genetic testing and completed a minimum of one year follow up were included. We compared the differences in clinical profile, seizure outcome, developmental characteristics and anti-seizure medication (ASM) responsiveness profiles between patients with missense and truncating variants. RESULTS Out of a total of 3967 children with drug-resistant epilepsy during the period 2015-2021, 49 patients who fulfilled the inclusion criteria were studied. Thirty-seven had positive genetic tests, out of which 29 were SCN1A variants and 9 were other novel variants. The proportion of missense (14; 48.3%) and truncating SCN1A variants (15; 51.7%) was similar. A significant trend for developing multiple seizure types was noted among children with truncating variants (p = 0.035) and seizure freedom was more likely among children with missense variants (p = 0.042). All patients with truncating variants had ASM resistant epilepsy (p = 0.020). Developmental outcomes did not differ between the variant subtypes. CONCLUSION Our results show that children harbouring missense variants demonstrated a significantly lower propensity for multiple seizure subtypes and a higher proportion with seizure freedom. However developmental implications appear to be independent of variant subtype.
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Affiliation(s)
- S Krishna
- R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Alfiya Fasaludeen
- R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Manna Jose
- R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Moinak Banerjee
- Human Molecular Genetics Laboratory, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
| | - Soumya Sundaram
- Comprehensive Care Centre for Neuodevelopmental Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Ashalatha Radhakrishnan
- R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Ramshekhar N Menon
- R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India; Comprehensive Care Centre for Neuodevelopmental Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
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30
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Cha J, Filatov G, Smith SJ, Gammaitoni AR, Lothe A, Reeder T. Fenfluramine increases survival and reduces markers of neurodegeneration in a mouse model of Dravet syndrome. Epilepsia Open 2024; 9:300-313. [PMID: 38018342 PMCID: PMC10839300 DOI: 10.1002/epi4.12873] [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: 05/03/2023] [Accepted: 11/21/2023] [Indexed: 11/30/2023] Open
Abstract
OBJECTIVE In patients with Dravet syndrome (DS), fenfluramine reduced convulsive seizure frequency and provided clinical benefit in nonseizure endpoints (e.g., executive function, survival). In zebrafish mutant scn1 DS models, chronic fenfluramine treatment preserved neuronal cytoarchitecture prior to seizure onset and prevented gliosis; here, we extend these findings to a mammalian model of DS (Scn1a+/- mice) by evaluating the effects of fenfluramine on neuroinflammation (degenerated myelin, activated microglia) and survival. METHODS Scn1a+/- DS mice were treated subcutaneously once daily with fenfluramine (15 mg/kg) or vehicle from postnatal day (PND) 7 until 35-37. Sagittal brain sections were processed for immunohistochemistry using antibodies to degraded myelin basic protein (D-MBP) for degenerated myelin, or CD11b for activated (inflammatory) microglia; sections were scored semi-quantitatively. Apoptotic nuclei were quantified by TUNEL assay. Statistical significance was evaluated by 1-way ANOVA with post-hoc Dunnett's test (D-MBP, CD11b, and TUNEL) or Logrank Mantel-Cox (survival). RESULTS Quantitation of D-MBP immunostaining per 0.1 mm2 unit area of the parietal cortex and hippocampus CA3 yielded significantly higher spheroidal and punctate myelin debris counts in vehicle-treated DS mice than in wild-type mice. Fenfluramine treatment in DS mice significantly reduced these counts. Activated CD11b + microglia were more abundant in DS mouse corpus callosum and hippocampus than in wild-type controls. Fenfluramine treatment of DS mice resulted in significantly fewer activated CD11b + microglia than vehicle-treated DS mice in these brain regions. TUNEL staining in corpus callosum was increased in DS mice relative to wild-type controls. Fenfluramine treatment in DS mice lowered TUNEL staining relative to vehicle-treated DS mice. By PND 35-37, 55% of control DS mice had died, compared with 24% of DS mice receiving fenfluramine treatment (P = 0.0291). SIGNIFICANCE This is the first report of anti-neuroinflammation and pro-survival after fenfluramine treatment in a mammalian DS model. These results corroborate prior data in humans and animal models and suggest important pharmacological activities for fenfluramine beyond seizure reduction. PLAIN LANGUAGE SUMMARY Dravet syndrome is a severe epilepsy disorder that impairs learning and causes premature death. Clinical studies in patients with Dravet syndrome show that fenfluramine reduces convulsive seizures. Additional studies suggest that fenfluramine may have benefits beyond seizures, including promoting survival and improving control over emotions and behavior. Our study is the first to use a Dravet mouse model to investigate nonseizure outcomes of fenfluramine. Results showed that fenfluramine treatment of Dravet mice reduced neuroinflammation significantly more than saline treatment. Fenfluramine-treated Dravet mice also lived longer than saline-treated mice. These results support clinical observations that fenfluramine may have benefits beyond seizures.
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Affiliation(s)
- John Cha
- University of California San FranciscoSan FranciscoCaliforniaUSA
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
| | - Gregory Filatov
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
- Crosshair Therapeutics, Inc.SunnyvaleCaliforniaUSA
| | - Steven J. Smith
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
- WuXi AppTec, Inc.San FranciscoCaliforniaUSA
| | | | | | - Thadd Reeder
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
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31
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Peall KJ, Owen MJ, Hall J. Rare genetic brain disorders with overlapping neurological and psychiatric phenotypes. Nat Rev Neurol 2024; 20:7-21. [PMID: 38001363 DOI: 10.1038/s41582-023-00896-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2023] [Indexed: 11/26/2023]
Abstract
Understanding rare genetic brain disorders with overlapping neurological and psychiatric phenotypes is of increasing importance given the potential for developing disease models that could help to understand more common, polygenic disorders. However, the traditional clinical boundaries between neurology and psychiatry result in frequent segregation of these disorders into distinct silos, limiting cross-specialty understanding that could facilitate clinical and biological advances. In this Review, we highlight multiple genetic brain disorders in which neurological and psychiatric phenotypes are observed, but for which in-depth, cross-spectrum clinical phenotyping is rarely undertaken. We describe the combined phenotypes observed in association with genetic variants linked to epilepsy, dystonia, autism spectrum disorder and schizophrenia. We also consider common underlying mechanisms that centre on synaptic plasticity, including changes to synaptic and neuronal structure, calcium handling and the balance of excitatory and inhibitory neuronal activity. Further investigation is needed to better define and replicate these phenotypes in larger cohorts, which would help to gain greater understanding of the pathophysiological mechanisms and identify common therapeutic targets.
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Affiliation(s)
- Kathryn J Peall
- Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, UK.
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.
| | - Michael J Owen
- Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, UK
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
- Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, UK
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
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32
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Smith J, Richerson G, Kouchi H, Duprat F, Mantegazza M, Bezin L, Rheims S. Are we there yet? A critical evaluation of sudden and unexpected death in epilepsy models. Epilepsia 2024; 65:9-25. [PMID: 37914406 DOI: 10.1111/epi.17812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/11/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023]
Abstract
Although animal models have helped to elaborate meaningful hypotheses about the pathophysiology of sudden and unexpected death in epilepsy (SUDEP), specific prevention strategies are still lacking, potentially reflecting the limitations of these models and the intrinsic difficulties of investigating SUDEP. The interpretation of preclinical data and their translation to diagnostic and therapeutic developments in patients thus require a high level of confidence in their relevance to model the human situation. Preclinical models of SUDEP are heterogeneous and include rodent and nonrodent species. A critical aspect is whether the animals have isolated seizures exclusively induced by a specific trigger, such as models where seizures are elicited by electrical stimulation, pharmacological intervention, or DBA mouse strains, or whether they suffer from epilepsy with spontaneous seizures, with or without spontaneous SUDEP, either of nongenetic epilepsy etiology or from genetically based developmental and epileptic encephalopathies. All these models have advantages and potential disadvantages, but it is important to be aware of these limitations to interpret data appropriately in a translational perspective. The majority of models with spontaneous seizures are of a genetic basis, whereas SUDEP cases with a genetic basis represent only a small proportion of the total number. In almost all models, cardiorespiratory arrest occurs during the course of the seizure, contrary to that in patients observed at the time of death, potentially raising the issue of whether we are studying models of SUDEP or models of periseizure death. However, some of these limitations are impossible to avoid and can in part be dependent on specific features of SUDEP, which may be difficult to model. Several preclinical tools are available to address certain gaps in SUDEP pathophysiology, which can be used to further validate current preclinical models.
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Affiliation(s)
- Jonathon Smith
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - George Richerson
- Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Hayet Kouchi
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - Fabrice Duprat
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Massimo Mantegazza
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Laurent Bezin
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - Sylvain Rheims
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon and Lyon 1 University, Lyon, France
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Ho SY, Chen IC, Tsai CW, Chang KC, Lin CJ, Chern Y, Liou HH. Anticonvulsant effect of equilibrative nucleoside transporters 1 inhibitor in a mouse model of Dravet syndrome. Hippocampus 2024; 34:7-13. [PMID: 37933097 DOI: 10.1002/hipo.23584] [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: 01/31/2023] [Revised: 10/09/2023] [Accepted: 10/13/2023] [Indexed: 11/08/2023]
Abstract
There are limited therapeutic options for patients with Dravet syndrome (DS). The equilibrative nucleoside transporters 1 (ENT1) mediate both the influx and efflux of adenosine across the cell membrane exerted beneficial effects in the treatment of epilepsy. This study aimed to evaluate the anticonvulsant effect of the ENT1 inhibitor in an animal model of DS (Scn1aE1099X/+ mice). J7 (5 mg/kg) treatment was efficacious in elevating seizure threshold in Scn1aE1099X/+ mice after hyperthermia exposure. Moreover, the J7 treatment significantly reduced the frequency of spontaneous excitatory post-synaptic currents (sEPSCs, ~35% reduction) without affecting the amplitude in dentate gyrus (DG) granule cells. Pretreatment with the adenosine A1 receptor (A1R) antagonist, DPCPX, abolished the J7 effects on sEPSCs. These observations suggest that the J7 shows an anticonvulsant effect in hyperthermia-induced seizures in Scn1aE1099X/+ mice. This effect possibly acts on presynaptic A1R-mediated signaling modulation in granule cells.
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Affiliation(s)
- Shih-Yin Ho
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical and Pharmaceutical Science, College of Medicine, Fu Jen Catholic University, New Taipei, Taiwan
- Department of Neurology, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei, Taiwan
| | - I-Chun Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Che-Wen Tsai
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kai-Chieh Chang
- Department of Neurology, National Taiwan University Hospital Yunlin Branch, Douliu, Taiwan
| | - Chun-Jung Lin
- School of Pharmacy, National Taiwan University, Taipei, Taiwan
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Horng-Huei Liou
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical and Pharmaceutical Science, College of Medicine, Fu Jen Catholic University, New Taipei, Taiwan
- Department of Neurology, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei, Taiwan
- Department of Neurology, National Taiwan University Hospital Yunlin Branch, Douliu, Taiwan
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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.
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Affiliation(s)
- Nina Doorn
- Department of Clinical Neurophysiology, University of Twente, Enschede, The Netherlands
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35
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Fan HC, Yang MT, Lin LC, Chiang KL, Chen CM. Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy. Int J Mol Sci 2023; 25:31. [PMID: 38203200 PMCID: PMC10779156 DOI: 10.3390/ijms25010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.
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Affiliation(s)
- Hueng-Chuen Fan
- Department of Pediatrics, Tungs’ Taichung Metroharbor Hospital, Wuchi, Taichung 435, Taiwan;
- Department of Rehabilitation, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 356, Taiwan
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
| | - Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan;
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan
| | - Lung-Chang Lin
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Kuo-Liang Chiang
- Department of Pediatric Neurology, Kuang-Tien General Hospital, Taichung 433, Taiwan;
- Department of Nutrition, Hungkuang University, Taichung 433, Taiwan
| | - Chuan-Mu Chen
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- The iEGG and Animal Biotechnology Center, and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan
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36
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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.
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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.
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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.
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Lersch R, Jannadi R, Grosse L, Wagner M, Schneider MF, von Stülpnagel C, Heinen F, Potschka H, Borggraefe I. Targeted Molecular Strategies for Genetic Neurodevelopmental Disorders: Emerging Lessons from Dravet Syndrome. Neuroscientist 2023; 29:732-750. [PMID: 35414300 PMCID: PMC10623613 DOI: 10.1177/10738584221088244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the SCN1A gene encoding the voltage-gated sodium channel α subunit Nav1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for SCN1A-related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional SCN1A or by activating Nav1.1. These include antisense nucleotides directed against the nonproductive transcript of SCN1A with the poison exon 20N and against an inhibitory noncoding antisense RNA of SCN1A. Gene therapy approaches such as adeno-associated virus-based upregulation of SCN1A using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.
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Affiliation(s)
- Robert Lersch
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Rawan Jannadi
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Leonie Grosse
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Matias Wagner
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute for Neurogenomics, Helmholtz Centre Munich, German Research Center for Health and Environment (GmbH), Munich, Germany
| | - Marius Frederik Schneider
- Metabolic Biochemistry, Biomedical Center Munich, Medical Faculty, Ludwig Maximilians University, Munich, Germany
- International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried, Germany
| | - Celina von Stülpnagel
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Research Institute for Rehabilitation, Transition and Palliation, Paracelsus Medical Private University (PMU), Salzburg, Austria
| | - Florian Heinen
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Ingo Borggraefe
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
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Arcos-Hernández C, Nishigaki T. Ion currents through the voltage sensor domain of distinct families of proteins. J Biol Phys 2023; 49:393-413. [PMID: 37851173 PMCID: PMC10651576 DOI: 10.1007/s10867-023-09645-z] [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: 04/28/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
The membrane potential of a cell (Vm) regulates several physiological processes. The voltage sensor domain (VSD) is a region that confers voltage sensitivity to different types of transmembrane proteins such as the following: voltage-gated ion channels, the voltage-sensing phosphatase (Ci-VSP), and the sperm-specific Na+/H+ exchanger (sNHE). VSDs contain four transmembrane segments (S1-S4) and several positively charged amino acids in S4, which are essential for the voltage sensitivity of the protein. Generally, in response to changes of the Vm, the positive residues of S4 displace along the plasma membrane without generating ionic currents through this domain. However, some native (e.g., Hv1 channel) and mutants of VSDs produce ionic currents. These gating pore currents are usually observed in VSDs that lack one or more of the conserved positively charged amino acids in S4. The gating pore currents can also be induced by the isolation of a VSD from the rest of the protein domains. In this review, we summarize gating pore currents from all families of proteins with VSDs with classification into three cases: (1) pathological, (2) physiological, and (3) artificial currents. We reinforce the model in which the position of S4 that lacks the positively charged amino acid determines the voltage dependency of the gating pore current of all VSDs independent of protein families.
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Affiliation(s)
- César Arcos-Hernández
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
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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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Borowicz-Reutt K, Czernia J, Krawczyk M. Genetic Background of Epilepsy and Antiepileptic Treatments. Int J Mol Sci 2023; 24:16280. [PMID: 38003469 PMCID: PMC10671416 DOI: 10.3390/ijms242216280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/01/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Advanced identification of the gene mutations causing epilepsy syndromes is expected to translate into faster diagnosis and more effective treatment of these conditions. Over the last 5 years, approximately 40 clinical trials on the treatment of genetic epilepsies have been conducted. As a result, some medications that are not regular antiseizure drugs (e.g., soticlestat, fenfluramine, or ganaxolone) have been introduced to the treatment of drug-resistant seizures in Dravet, Lennox-Gastaut, maternally inherited chromosome 15q11.2-q13.1 duplication (Dup 15q) syndromes, and protocadherin 19 (PCDH 19)-clusterig epilepsy. And although the effects of soticlestat, fenfluramine, and ganaxolone are described as promising, they do not significantly affect the course of the mentioned epilepsy syndromes. Importantly, each of these syndromes is related to mutations in several genes. On the other hand, several mutations can occur within one gene, and different gene variants may be manifested in different disease phenotypes. This complex pattern of inheritance contributes to rather poor genotype-phenotype correlations. Hence, the detection of a specific mutation is not synonymous with a precise diagnosis of a specific syndrome. Bearing in mind that seizures develop as a consequence of the predominance of excitatory over inhibitory processes, it seems reasonable that mutations in genes encoding sodium and potassium channels, as well as glutamatergic and gamma-aminobutyric (GABA) receptors, play a role in the pathogenesis of epilepsy. In some cases, different pathogenic variants of the same gene can result in opposite functional effects, determining the effectiveness of therapy with certain medications. For instance, seizures related to gain-of-function (GoF) mutations in genes encoding sodium channels can be successfully treated with sodium channel blockers. On the contrary, the same drugs may aggravate seizures related to loss-of-function (LoF) variants of the same genes. Hence, knowledge of gene mutation-treatment response relationships facilitates more favorable selection of drugs for anticonvulsant therapy.
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Affiliation(s)
- Kinga Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Toxicology, Medical University of Lublin, Jaczewskiego 8b, 20-090 Lublin, Poland; (J.C.); (M.K.)
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Ulyanova AV, Adam CD, Cottone C, Maheshwari N, Grovola MR, Fruchet OE, Alamar J, Koch PF, Johnson VE, Cullen DK, Wolf JA. Hippocampal interneuronal dysfunction and hyperexcitability in a porcine model of concussion. Commun Biol 2023; 6:1136. [PMID: 37945934 PMCID: PMC10636018 DOI: 10.1038/s42003-023-05491-w] [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: 03/18/2022] [Accepted: 10/19/2023] [Indexed: 11/12/2023] Open
Abstract
Cognitive impairment is a common symptom following mild traumatic brain injury (mTBI or concussion) and can persist for years in some individuals. Hippocampal slice preparations following closed-head, rotational acceleration injury in swine have previously demonstrated reduced axonal function and hippocampal circuitry disruption. However, electrophysiological changes in hippocampal neurons and their subtypes in a large animal mTBI model have not been examined. Using in vivo electrophysiology techniques, we examined laminar oscillatory field potentials and single unit activity in the hippocampal network 7 days post-injury in anesthetized minipigs. Concussion altered the electrophysiological properties of pyramidal cells and interneurons differently in area CA1. While the firing rate, spike width and amplitude of CA1 interneurons were significantly decreased post-mTBI, these parameters were unchanged in CA1 pyramidal neurons. In addition, CA1 pyramidal neurons in TBI animals were less entrained to hippocampal gamma (40-80 Hz) oscillations. Stimulation of the Schaffer collaterals also revealed hyperexcitability across the CA1 lamina post-mTBI. Computational simulations suggest that reported changes in interneuronal physiology may be due to alterations in voltage-gated sodium channels. These data demonstrate that a single concussion can lead to significant neuronal and circuit level changes in the hippocampus, which may contribute to cognitive dysfunction following mTBI.
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Affiliation(s)
- Alexandra V Ulyanova
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, USA
| | - Christopher D Adam
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Carlo Cottone
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Nikhil Maheshwari
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Michael R Grovola
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Oceane E Fruchet
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Jami Alamar
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Paul F Koch
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Victoria E Johnson
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - D Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, USA
| | - John A Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA.
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, USA.
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Manning A, Han V, Stephens A, Wang R, Bush N, Bard M, Ramirez JM, Kalume F. Elevated susceptibility to exogenous seizure triggers and impaired interneuron excitability in a mouse model of Leigh syndrome epilepsy. Neurobiol Dis 2023; 187:106288. [PMID: 37704057 PMCID: PMC10621616 DOI: 10.1016/j.nbd.2023.106288] [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: 05/28/2023] [Revised: 08/12/2023] [Accepted: 09/10/2023] [Indexed: 09/15/2023] Open
Abstract
Mutations in the NADH dehydrogenase (ubiquinone reductase) iron‑sulfur protein 4 (NDUFS4) gene, which encodes for a key structural subunit of the OXFOS complex I (CI), lead to the most common form of mitochondrial disease in children known as Leigh syndrome (LS). As in other mitochondrial diseases, epileptic seizures constitute one of the most significant clinical features of LS. These seizures are often very difficult to treat and are a sign of poor disease prognosis. Mice with whole-body Ndufs4 KO are a well-validated model of LS; they exhibit epilepsy and several other clinical features of LS. We have previously shown that mice with Ndufs4 KO in only GABAergic interneurons (Gad2-Ndufs4-KO) reproduce the severe epilepsy phenotype observed in the global KO mice. This observation indicated that these mice represent an excellent model of LS epilepsy isolated from other clinical manifestations of the disease. To further characterize this epilepsy phenotype, we investigated seizure susceptibility to selected exogenous seizure triggers in Gad2-Ndufs4-KO mice. Then, using electrophysiology, imaging, and immunohistochemistry, we studied the cellular, physiological, and neuroanatomical consequences of Ndufs4 KO in GABAergic interneurons. Homozygous KO of Ndufs4 in GABAergic interneurons leads to a prominent susceptibility to exogenous seizure triggers, impaired interneuron excitability and interneuron loss. Finally, we found that the hippocampus and cortex participate in the generation of seizure activity in Gad2-Ndufs4-KO mice. These findings further define the LS epilepsy phenotype and provide important insights into the cellular mechanisms underlying epilepsy in LS and other mitochondrial diseases.
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Affiliation(s)
- Arena Manning
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States of America; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Victor Han
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Alexa Stephens
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Rose Wang
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Nicholas Bush
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Michelle Bard
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America
| | - Jan M Ramirez
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States of America; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America; Department of Neurological Surgery, University of Washington, Seattle, WA, United States of America
| | - Franck Kalume
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States of America; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States of America; Department of Neurological Surgery, University of Washington, Seattle, WA, United States of America.
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Nakakubo S, Hiramatsu Y, Goto T, Kimura S, Narugami M, Nakajima M, Ueda Y, Shiraishi H, Manabe A, Sharmin D, Cook JM, Egawa K. Therapeutic effects of KRM-II-81, positive allosteric modulator for α2/3 subunit containing GABA A receptors, in a mouse model of Dravet syndrome. Front Pharmacol 2023; 14:1273633. [PMID: 37849734 PMCID: PMC10577232 DOI: 10.3389/fphar.2023.1273633] [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: 08/06/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction: Dravet syndrome (DS) is an intractable epilepsy syndrome concomitant with neurodevelopmental disorder that begins in infancy. DS is dominantly caused by mutations in the SCN1A gene, which encodes the α subunit of a voltage-gated Na channel. Pre-synaptic inhibitory dysfunction is regarded as the pathophysiological mechanism, but an effective strategy for ameliorating seizures and behavioral problems is still under development. Here, we evaluated the effects of KRM-II-81, a newly developed positive allosteric modulator for α 2/3 subunit containing GABAA receptors (α2/3-GABAAR) in a mice model of DS both in vivo and at the neuronal level. Methods: We used knock-in mice carrying a heterozygous, clinically relevant SCN1A mutation (background strain: C57BL/6 J) as a model of the DS (Scn1a WT/A1783V mice), knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V). Seizure threshold and locomotor activity was evaluated by using the hyperthermia-induced seizure paradigm and open filed test, respectively. Anxiety-like behavior was assessed by avoidance of the center region in locomotor activity. We estimated a sedative effect by the total distance traveled in locomotor activity and grip strength. Inhibitory post synaptic currents (IPSCs) were recorded from a hippocampal CA1 pyramidal neuron in an acutely prepared brain slice. Results: KRM-II-81 significantly increased the seizure threshold of Scn1a WT/A1783V mice in a dose-dependent manner. A low dose of KRM-II-81 specifically improved anxiety-like behavior of Scn1a WT/A1783V mice. A sedative effect was induced by relatively high dose of KRM-II-81 in Scn1a WT/A1783V mice, the dose of which was not sedative for WT mice. KRM-II-81 potentiated IPSCs by increasing its decay time kinetics. This effect was more prominent in Scn1a WT/A1783V mice. Discussion: Higher activation of α2/3-GABAAR by KRM-II-81 suggests a compensatory modification of post synaptic inhibitory function against presynaptic inhibitory dysfunction in Scn1a WT/A1783V. The increased sensitivity for KRM-II-81 may be relevant to the distinct dose-dependent effect in each paradigm of Scn1a WT/A1783V mice. Conclusion: Selective activation for α2/3-GABAAR by KRM-II-81 could be potential therapeutic strategy for treating seizures and behavioral problems in DS.
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Affiliation(s)
- Sachiko Nakakubo
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yasuyoshi Hiramatsu
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Takeru Goto
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Syuhei Kimura
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Masashi Narugami
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Midori Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yuki Ueda
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Atsushi Manabe
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Dishary Sharmin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
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Fukushima K, Higashiyama H, Kazuta Y, Hashimoto K, Watanabe N, Furuya Y, Ito Y, Wu T, Kosasa T, Talos DM, Song Y, Roberts NS, Jensen FE, Hanada T, Ido K. Discovery of E2730, a novel selective uncompetitive GAT1 inhibitor, as a candidate for anti-seizure medication. Epilepsia Open 2023; 8:834-845. [PMID: 37052238 PMCID: PMC10472371 DOI: 10.1002/epi4.12741] [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: 12/12/2022] [Accepted: 04/08/2023] [Indexed: 04/14/2023] Open
Abstract
OBJECTIVE As of 2022, 36 anti-seizure medications (ASMs) have been licensed for the treatment of epilepsy, however, adverse effects (AEs) are commonly reported. Therefore, ASMs with a wide margin between therapeutic effects and AEs are preferred over ASMs that are associated with a narrow margin between efficacy and risk of AEs. E2730 was discovered using in vivo phenotypic screening and characterized as an uncompetitive, yet selective, inhibitor of γ-aminobutyric acid (GABA) transporter 1 (GAT1). Here, we describe the preclinical characteristics of E2730. METHODS Anti-seizure effects of E2730 were evaluated in several animal models of epilepsy: corneal kindling, 6 Hz-44 mA psychomotor seizure, amygdala kindling, Fragile X syndrome, and Dravet syndrome models. Effects of E2730 on motor coordination were assessed in accelerating rotarod tests. The mechanism of action of E2730 was explored by [3 H]E2730 binding assay. The GAT1-selectivity over other GABA transporters was examined by GABA uptake assay of GAT1, GAT2, GAT3, or betaine/GABA transporter 1 (BGT-1) stably expressing HEK293 cells. To further investigate the mechanism for E2730-mediated inhibition of GAT1, in vivo microdialysis and in vitro GABA uptake assays were conducted under conditions of different GABA concentrations. RESULTS E2730 showed anti-seizure effects in the assessed animal models with an approximately >20-fold margin between efficacy and motor incoordination. [3 H]E2730 binding on brain synaptosomal membrane was abolished in GAT1-deficient mice, and E2730 selectively inhibited GAT1-mediated GABA uptake over other GABA transporters. In addition, results of GABA uptake assays showed that E2730-mediated inhibition of GAT1 positively correlated to the level of ambient GABA in vitro. E2730 also increased extracellular GABA concentration in hyperactivated conditions but not under basal levels in vivo. SIGNIFICANCE E2730 is a novel, selective, uncompetitive GAT1 inhibitor, which acts selectively under the condition of increasing synaptic activity, contributing to a wide margin between therapeutic effect and motor incoordination.
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Affiliation(s)
| | | | - Yuji Kazuta
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | | | - Naoto Watanabe
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Yoshiaki Furuya
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Yoshimasa Ito
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
| | - Ting Wu
- Alzheimer's Disease and Brain HealthEisai Co., Ltd.TsukubaIbarakiJapan
| | - Takashi Kosasa
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
| | - Delia M. Talos
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Yeri Song
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Nicholas S. Roberts
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Frances E. Jensen
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Takahisa Hanada
- Deep Human Biology LearningEisai Co., Ltd.TsukubaIbarakiJapan
| | - Katsutoshi Ido
- Neurology Business GroupEisai Co., Ltd.TsukubaIbarakiJapan
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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.
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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.
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Hameed MQ, Hui B, Lin R, MacMullin PC, Pascual‐Leone A, Vermudez SAD, Rotenberg A. Depressed glutamate transporter 1 expression in a mouse model of Dravet syndrome. Ann Clin Transl Neurol 2023; 10:1695-1699. [PMID: 37452008 PMCID: PMC10502630 DOI: 10.1002/acn3.51851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/06/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023] Open
Abstract
Dravet syndrome (DS) is a monogenic, often refractory, epilepsy resultant from SCN1A haploinsufficiency in humans. A novel therapeutic target in DS that can be engaged in isolation or as adjunctive therapy is highly desirable. Here, we demonstrate reduced expression of the rodent glutamate transporter type 1 (GLT-1) in a DS mouse model, and in wild type mouse strains where Scn1a haploinsufficiency is most likely to cause epilepsy, indicating that GLT-1 depression may play a role in DS seizures. As GLT-1 can be upregulated by common and safe FDA-approved medications, this strategy may be an attractive, viable, and novel avenue for DS treatment.
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Affiliation(s)
- Mustafa Q. Hameed
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- Department of NeurosurgeryBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Benjamin Hui
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Rui Lin
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Paul C. MacMullin
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Andres Pascual‐Leone
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Sheryl Anne D. Vermudez
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Alexander Rotenberg
- Neuromodulation Program, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- FM Kirby Neurobiology Center, Department of NeurologyBoston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
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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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Rusina E, Simonti M, Duprat F, Cestèle S, Mantegazza M. Voltage-gated sodium channels in genetic epilepsy: up and down of excitability. J Neurochem 2023. [PMID: 37654020 DOI: 10.1111/jnc.15947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 09/02/2023]
Abstract
The past two decades have witnessed a wide range of studies investigating genetic variants of voltage-gated sodium (NaV ) channels, which are involved in a broad spectrum of diseases, including several types of epilepsy. We have reviewed here phenotypes and pathological mechanisms of genetic epilepsies caused by variants in NaV α and β subunits, as well as of some relevant interacting proteins (FGF12/FHF1, PRRT2, and Ankyrin-G). Notably, variants of all these genes can induce either gain- or loss-of-function of NaV leading to either neuronal hyperexcitability or hypoexcitability. We present the results of functional studies obtained with different experimental models, highlighting that they should be interpreted considering the features of the experimental system used. These systems are models, but they have allowed us to better understand pathophysiological issues, ameliorate diagnostics, orientate genetic counseling, and select/develop therapies within a precision medicine framework. These studies have also allowed us to gain insights into the physiological roles of different NaV channels and of the cells that express them. Overall, our review shows the progress that has been made, but also the need for further studies on aspects that have not yet been clarified. Finally, we conclude by highlighting some significant themes of general interest that can be gleaned from the results of the work of the last two decades.
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Affiliation(s)
- Evgeniia Rusina
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Martina Simonti
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Fabrice Duprat
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Massimo Mantegazza
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
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50
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Gosalia H, Karsan N, Goadsby PJ. Genetic Mechanisms of Migraine: Insights from Monogenic Migraine Mutations. Int J Mol Sci 2023; 24:12697. [PMID: 37628876 PMCID: PMC10454024 DOI: 10.3390/ijms241612697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/01/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023] Open
Abstract
Migraine is a disabling neurological disorder burdening patients globally. Through the increasing development of preclinical and clinical experimental migraine models, advancing appreciation of the extended clinical phenotype, and functional neuroimaging studies, we can further our understanding of the neurobiological basis of this highly disabling condition. Despite increasing understanding of the molecular and chemical architecture of migraine mechanisms, many areas require further investigation. Research over the last three decades has suggested that migraine has a strong genetic basis, based on the positive family history in most patients, and this has steered exploration into possibly implicated genes. In recent times, human genome-wide association studies and rodent genetic migraine models have facilitated our understanding, but most migraine seems polygenic, with the monogenic migraine mutations being considerably rarer, so further large-scale studies are required to elucidate fully the genetic underpinnings of migraine and the translation of these to clinical practice. The monogenic migraine mutations cause severe aura phenotypes, amongst other symptoms, and offer valuable insights into the biology of aura and the relationship between migraine and other conditions, such as vascular disease and sleep disorders. This review will provide an outlook of what is known about some monogenic migraine mutations, including familial hemiplegic migraine, familial advanced sleep-phase syndrome, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
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Affiliation(s)
- Helin Gosalia
- Headache Group, The Wolfson Sensory, Pain and Rehabilitation Centre, NIHR King’s Clinical Research Facility, & SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 9PJ, UK; (H.G.); (N.K.)
| | - Nazia Karsan
- Headache Group, The Wolfson Sensory, Pain and Rehabilitation Centre, NIHR King’s Clinical Research Facility, & SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 9PJ, UK; (H.G.); (N.K.)
| | - Peter J. Goadsby
- Headache Group, The Wolfson Sensory, Pain and Rehabilitation Centre, NIHR King’s Clinical Research Facility, & SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 9PJ, UK; (H.G.); (N.K.)
- Department of Neurology, University of California, Los Angeles, CA 90095, USA
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