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Spyrou J, Aung KP, Vanyai H, Leventer RJ, Maljevic S, Lockhart PJ, Howell KB, Reid CA. Slc35a2 mosaic knockout impacts cortical development, dendritic arborisation, and neuronal firing. Neurobiol Dis 2024; 201:106657. [PMID: 39236911 DOI: 10.1016/j.nbd.2024.106657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 09/01/2024] [Accepted: 09/02/2024] [Indexed: 09/07/2024] Open
Abstract
Mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) is an important cause of drug-resistant epilepsy. A significant subset of individuals diagnosed with MOGHE display somatic mosaicism for loss-of-function variants in SLC35A2, which encodes the UDP-galactose transporter. We developed a mouse model to investigate how disruption of this transporter leads to a malformation of cortical development. We used in utero electroporation and CRISPR/Cas9 to knockout Slc35a2 in a subset of layer 2/3 cortical neuronal progenitors in the developing brains of male and female fetal mice to model mosaic expression. Mosaic Slc35a2 knockout was verified through next-generation sequencing and immunohistochemistry of GFP-labelled transfected cells. Histology of brain tissue in mosaic Slc35a2 knockout mice revealed the presence of upper layer-derived cortical neurons in the white matter. Reconstruction of single filled neurons identified altered dendritic arborisation with Slc35a2 knockout neurons having increased complexity. Whole-cell electrophysiological recordings revealed that Slc35a2 knockout neurons display reduced action potential firing, increased afterhyperpolarisation duration and reduced burst-firing when compared with control neurons. Mosaic Slc35a2 knockout mice also exhibited significantly increased epileptiform spiking and increased locomotor activity. We successfully generated a mouse model of mosaic Slc35a2 deficiency, which recapitulates features of the human phenotype, including impaired neuronal migration. We show that knockout in layer 2/3 cortical neuron progenitors is sufficient to disrupt neuronal excitability, increase epileptiform activity and cause hyperactivity in mosaic mice. Our mouse model provides an opportunity to further investigate the disease mechanisms that contribute to MOGHE and facilitate the development of precision therapies.
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Affiliation(s)
- James Spyrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia; Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Khaing Phyu Aung
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Hannah Vanyai
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Richard J Leventer
- Department of Neurology, Royal Children's Hospital, Parkville, VIC 3052, Australia; Murdoch Children's Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Paul J Lockhart
- Murdoch Children's Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Katherine B Howell
- Department of Neurology, Royal Children's Hospital, Parkville, VIC 3052, Australia; Murdoch Children's Research Institute, Parkville, VIC 3052, Australia
| | - Christopher A Reid
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia; Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia.
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2
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Abstract
ABSTRACT The SCN2A gene encodes a subunit that forms part of voltage-gated sodium channels in the brain. Gain-of-function mutations are associated with epilepsy as well as numerous movement/motor abnormalities. Loss-of-function mutations may also cause epilepsy in addition to a variety of neurodevelopmental anomalies, including autism and intellectual disability. The occurrence of catatonia has also been described in 1 previous report that involved a 4-year-old boy. We describe a 20-year-old intellectually disabled female patient who developed recurrent catatonic symptoms in her teenage years that remitted with electroconvulsive therapy. This is only the second report of catatonia occurring in relation to an SCN2A mutation and the first involving a female. Moreover, this case is unique given our patient's later age of symptom onset and given that her symptoms responded well to electroconvulsive therapy.
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Egido-Betancourt HX, Strowd Iii RE, Raab-Graham KF. Potential roles of voltage-gated ion channel disruption in Tuberous Sclerosis Complex. Front Mol Neurosci 2024; 17:1404884. [PMID: 39253727 PMCID: PMC11381416 DOI: 10.3389/fnmol.2024.1404884] [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: 03/21/2024] [Accepted: 06/27/2024] [Indexed: 09/11/2024] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a lynchpin disorder, as it results in overactive mammalian target of rapamycin (mTOR) signaling, which has been implicated in a multitude of disease states. TSC is an autosomal dominant disease where 90% of affected individuals develop epilepsy. Epilepsy results from aberrant neuronal excitability that leads to recurring seizures. Under neurotypical conditions, the coordinated activity of voltage-gated ion channels keep neurons operating in an optimal range, thus providing network stability. Interestingly, loss or gain of function mutations in voltage-gated potassium, sodium, or calcium channels leads to altered excitability and seizures. To date, little is known about voltage-gated ion channel expression and function in TSC. However, data is beginning to emerge on how mTOR signaling regulates voltage-gated ion channel expression in neurons. Herein, we provide a comprehensive review of the literature describing common seizure types in patients with TSC, and suggest possible parallels between acquired epilepsies with known voltage-gated ion channel dysfunction. Furthermore, we discuss possible links toward mTOR regulation of voltage-gated ion channels expression and channel kinetics and the underlying epileptic manifestations in patients with TSC.
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Affiliation(s)
- Hailey X Egido-Betancourt
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Roy E Strowd Iii
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Kimberly F Raab-Graham
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem, NC, United States
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4
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Wu J, Zhang J, Chen X, Wettschurack K, Que Z, Deming BA, Olivero-Acosta MI, Cui N, Eaton M, Zhao Y, Li SM, Suzuki M, Chen I, Xiao T, Halurkar MS, Mandal P, Yuan C, Xu R, Koss WA, Du D, Chen F, Wu LJ, Yang Y. Microglial over-pruning of synapses during development in autism-associated SCN2A-deficient mice and human cerebral organoids. Mol Psychiatry 2024; 29:2424-2437. [PMID: 38499656 DOI: 10.1038/s41380-024-02518-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 02/29/2024] [Accepted: 03/04/2024] [Indexed: 03/20/2024]
Abstract
Autism spectrum disorder (ASD) is a major neurodevelopmental disorder affecting 1 in 36 children in the United States. While neurons have been the focus of understanding ASD, an altered neuro-immune response in the brain may be closely associated with ASD, and a neuro-immune interaction could play a role in the disease progression. As the resident immune cells of the brain, microglia regulate brain development and homeostasis via core functions including phagocytosis of synapses. While ASD has been traditionally considered a polygenic disorder, recent large-scale human genetic studies have identified SCN2A deficiency as a leading monogenic cause of ASD and intellectual disability. We generated a Scn2a-deficient mouse model, which displays major behavioral and neuronal phenotypes. However, the role of microglia in this disease model is unknown. Here, we reported that Scn2a-deficient mice have impaired learning and memory, accompanied by reduced synaptic transmission and lower spine density in neurons of the hippocampus. Microglia in Scn2a-deficient mice are partially activated, exerting excessive phagocytic pruning of post-synapses related to the complement C3 cascades during selective developmental stages. The ablation of microglia using PLX3397 partially restores synaptic transmission and spine density. To extend our findings from rodents to human cells, we established a microglia-incorporated human cerebral organoid model carrying an SCN2A protein-truncating mutation identified in children with ASD. We found that human microglia display increased elimination of post-synapse in cerebral organoids carrying the SCN2A mutation. Our study establishes a key role of microglia in multi-species autism-associated models of SCN2A deficiency from mouse to human cells.
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Affiliation(s)
- Jiaxiang Wu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Jingliang Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Xiaoling Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Kyle Wettschurack
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Zhefu Que
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Brody A Deming
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Maria I Olivero-Acosta
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Ningren Cui
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Muriel Eaton
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Yuanrui Zhao
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Sophia M Li
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Matthew Suzuki
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Ian Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Tiange Xiao
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Manasi S Halurkar
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Purba Mandal
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Ranjie Xu
- College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Wendy A Koss
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Dongshu Du
- School of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Fuxue Chen
- School of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA.
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA.
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5
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Miyazaki H, Nishioka S, Yamanaka T, Abe M, Imamura Y, Miyasaka T, Kakuda N, Oohashi T, Shimogori T, Yamakawa K, Ikawa M, Nukina N. Generation and characterization of cerebellar granule neurons specific knockout mice of Golli-MBP. Transgenic Res 2024; 33:99-117. [PMID: 38684589 PMCID: PMC11176102 DOI: 10.1007/s11248-024-00382-0] [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: 11/30/2023] [Accepted: 04/02/2024] [Indexed: 05/02/2024]
Abstract
Golli-myelin basic proteins, encoded by the myelin basic protein gene, are widely expressed in neurons and oligodendrocytes in the central nervous system. Further, prior research has shown that Golli-myelin basic protein is necessary for myelination and neuronal maturation during central nervous system development. In this study, we established Golli-myelin basic protein-floxed mice to elucidate the cell-type-specific effects of Golli-myelin basic protein knockout through the generation of conditional knockout mice (Golli-myelin basic proteinsfl/fl; E3CreN), in which Golli-myelin basic proteins were specifically deleted in cerebellar granule neurons, where Golli-myelin basic proteins are expressed abundantly in wild-type mice. To investigate the role of Golli-myelin basic proteins in cerebellar granule neurons, we further performed histopathological analyses of these mice, with results indicating no morphological changes or degeneration of the major cellular components of the cerebellum. Furthermore, behavioral analysis showed that Golli-myelin basic proteinsfl/fl; E3CreN mice were healthy and did not display any abnormal behavior. These results suggest that the loss of Golli-myelin basic proteins in cerebellar granule neurons does not lead to cerebellar perturbations or behavioral abnormalities. This mouse model could therefore be employed to analyze the effect of Golli-myelin basic protein deletion in specific cell types of the central nervous system, such as other neuronal cells and oligodendrocytes, or in lymphocytes of the immune system.
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Grants
- 16K07005 Grants-in-Aid from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan
- 16H06276 Grants-in-Aid from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan
- 17H01564 Grants-in-Aid from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan
- 20ek0109310h0003 AMED
- The Center for Baby Science, Doshisha University
- Takeda Science Foundation
- Ichiro Kanehara Foundation for the Promotion of Medical Sciences and Medical Care
- Okayama University
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Affiliation(s)
- Haruko Miyazaki
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan.
- Department of Molecular Biology and Biochemistry, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
| | - Saki Nishioka
- Department of Experimental Genome Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, 1-757 Asahimachidori, Chuo-ku, Niigata, 951-8585, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, 1-757 Asahimachidori, Chuo-ku, Niigata, 951-8585, Japan
| | - Yukio Imamura
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan
| | - Tomohiro Miyasaka
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan
| | - Nobuto Kakuda
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan
| | - Toshitaka Oohashi
- Department of Molecular Biology and Biochemistry, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Tomomi Shimogori
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Sciences, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Masahito Ikawa
- Department of Experimental Genome Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto, 610-0394, Japan.
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6
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Marcombe S, Doeurk B, Thammavong P, Veseli T, Heafield C, Mills MA, Kako S, Prado MF, Thomson S, Millett S, Hill T, Kentsley I, Davies S, Pathiraja G, Daniels B, Browne L, Nyamukanga M, Harvey J, Rubinstein L, Townsend C, Allen Z, Davey-Spence C, Hupi A, Jones AK, Boyer S. Metabolic Resistance and Not Voltage-Gated Sodium Channel Gene Mutation Is Associated with Pyrethroid Resistance of Aedes albopictus (Skuse, 1894) from Cambodia. INSECTS 2024; 15:358. [PMID: 38786914 PMCID: PMC11122440 DOI: 10.3390/insects15050358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
(1) Background: In Cambodia, Aedes albopictus is an important vector of the dengue virus. Vector control using insecticides is a major strategy implemented in managing mosquito-borne diseases. Resistance, however, threatens to undermine the use of insecticides. In this study, we present the levels of insecticide resistance of Ae. albopictus in Cambodia and the mechanisms involved. (2) Methods: Two Ae. albopictus populations were collected from the capital, Phnom Penh city, and from rural Pailin province. Adults were tested with diagnostic doses of malathion (0.8%), deltamethrin (0.03%), permethrin (0.25%), and DDT (4%) using WHO tube assays. Synergist assays using piperonyl butoxide (PBO) were implemented before the pyrethroid assays to detect the potential involvement of metabolic resistance mechanisms. Adult female mosquitoes collected from Phnom Penh and Pailin were tested for voltage-gated sodium channel (VGSC) kdr (knockdown resistance) mutations commonly found in Aedes sp.-resistant populations throughout Asia (S989P, V1016G, and F1534C), as well as for other mutations (V410L, L982W, A1007G, I1011M, T1520I, and D1763Y). (3) Results: The two populations showed resistance against all the insecticides tested (<90% mortality). The use of PBO (an inhibitor of P450s) strongly restored the efficacy of deltamethrin and permethrin against the two resistant populations. Sequences of regions of the vgsc gene showed a lack of kdr mutations known to be associated with pyrethroid resistance. However, four novel non-synonymous mutations (L412P/S, C983S, Q1554STOP, and R1718L) and twenty-nine synonymous mutations were detected. It remains to be determined whether these mutations contribute to pyrethroid resistance. (4) Conclusions: Pyrethroid resistance is occurring in two Ae. albopictus populations originating from urban and rural areas of Cambodia. The resistance is likely due to metabolic resistance specifically involving P450s monooxygenases. The levels of resistance against different insecticide classes are a cause for concern in Cambodia. Alternative tools and insecticides for controlling dengue vectors should be used to minimize disease prevalence in the country.
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Affiliation(s)
- Sébastien Marcombe
- Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos; (S.M.); (P.T.)
- Vector Control Consulting—South East Asia Sole Co., Ltd., Vientiane P.O. Box 3463, Laos
| | - Bros Doeurk
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia; (B.D.); (S.B.)
| | - Phoutmany Thammavong
- Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos; (S.M.); (P.T.)
| | - Tuba Veseli
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Derby DE65 5NX, UK
| | - Christian Heafield
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Oxford OX14 2RN, UK
| | - Molly-Ann Mills
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK
| | - Sedra Kako
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Marcelly Ferreira Prado
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Oxford University Hospitals, Churchill Hospital, Genetics Laboratories, Old Rd, Headington, Oxford OX3 7LE, UK
| | - Shakira Thomson
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Burnham-On-Sea TA8 1AZ, UK
| | - Saffron Millett
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Timothy Hill
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Imogen Kentsley
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Brighton BN8 4HR, UK
| | - Shereena Davies
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Shrewsbury SY1 4YP, UK
| | - Geethika Pathiraja
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Wallingford OX10 7EA, UK
| | - Ben Daniels
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Syngenta, Jealott’s Hill International Research Centre, Bracknell RG42 6EY, Berkshire, UK
| | - Lucianna Browne
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Reading RG31 4SE, UK
| | - Miranda Nyamukanga
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Wythenshawe Hospital, Southmoor Rd, Wythenshawe M23 9LT, Manchester, UK
| | - Jess Harvey
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Oxford Nanopore Technologies plc, Unit 3, Genesis Building, Library Avenue, Harwell, Didcot OX11 0SG, Oxfordshire, UK
| | - Lyranne Rubinstein
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, 69009 Lyon, France
| | - Chloe Townsend
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Zack Allen
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Christopher Davey-Spence
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Adina Hupi
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Oxford OX3 8HP, UK
| | - Andrew K. Jones
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia; (B.D.); (S.B.)
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7
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Mao M, Mattei C, Rollo B, Byars S, Cuddy C, Berecki G, Heighway J, Pachernegg S, Menheniott T, Apted D, Jia L, Dalby K, Nemiroff A, Mullen S, Reid CA, Maljevic S, Petrou S. Distinctive In Vitro Phenotypes in iPSC-Derived Neurons From Patients With Gain- and Loss-of-Function SCN2A Developmental and Epileptic Encephalopathy. J Neurosci 2024; 44:e0692232023. [PMID: 38148154 PMCID: PMC10883610 DOI: 10.1523/jneurosci.0692-23.2023] [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: 04/17/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 12/28/2023] Open
Abstract
SCN2A encodes NaV1.2, an excitatory neuron voltage-gated sodium channel and a major monogenic cause of neurodevelopmental disorders, including developmental and epileptic encephalopathies (DEE) and autism. Clinical presentation and pharmocosensitivity vary with the nature of SCN2A variant dysfunction and can be divided into gain-of-function (GoF) cases with pre- or peri-natal seizures and loss-of-function (LoF) patients typically having infantile spasms after 6 months of age. We established and assessed patient induced pluripotent stem cell (iPSC) - derived neuronal models for two recurrent SCN2A DEE variants with GoF R1882Q and LoF R853Q associated with early- and late-onset DEE, respectively. Two male patient-derived iPSC isogenic pairs were differentiated using Neurogenin-2 overexpression yielding populations of cortical-like glutamatergic neurons. Functional properties were assessed using patch clamp and multielectrode array recordings and transcriptomic profiles obtained with total mRNA sequencing after 2-4 weeks in culture. At 3 weeks of differentiation, increased neuronal activity at cellular and network levels was observed for R1882Q iPSC-derived neurons. In contrast, R853Q neurons showed only subtle changes in excitability after 4 weeks and an overall reduced network activity after 7 weeks in vitro. Consistent with the reported efficacy in some GoF SCN2A patients, phenytoin (sodium channel blocker) reduced the excitability of neurons to the control levels in R1882Q neuronal cultures. Transcriptomic alterations in neurons were detected for each variant and convergent pathways suggested potential shared mechanisms underlying SCN2A DEE. In summary, patient iPSC-derived neuronal models of SCN2A GoF and LoF pathogenic variants causing DEE show specific functional and transcriptomic in vitro phenotypes.
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Affiliation(s)
- Miaomiao Mao
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Cristiana Mattei
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Ben Rollo
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3800, Australia
| | - Sean Byars
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Claire Cuddy
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Geza Berecki
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Jacqueline Heighway
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Svenja Pachernegg
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Trevelyan Menheniott
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Danielle Apted
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Linghan Jia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Kelley Dalby
- Rogcon Biosciences, Cambridge, MA 02142
- Praxis Precision Medicines, Inc., Cambridge, MA 02142
| | - Alex Nemiroff
- Rogcon Biosciences, Cambridge, MA 02142
- Praxis Precision Medicines, Inc., Cambridge, MA 02142
| | - Saul Mullen
- Austin Health, University of Melbourne, Melbourne, Victoria 3084, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Snezana Maljevic
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3052, Australia
- Praxis Precision Medicines, Inc., Cambridge, MA 02142
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8
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Suzuki T, Hattori S, Mizukami H, Nakajima R, Hibi Y, Kato S, Matsuzaki M, Ikebe R, Miyakawa T, Yamakawa K. Inversed Effects of Nav1.2 Deficiency at Medial Prefrontal Cortex and Ventral Tegmental Area for Prepulse Inhibition in Acoustic Startle Response. Mol Neurobiol 2024; 61:622-634. [PMID: 37650965 DOI: 10.1007/s12035-023-03610-6] [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: 01/05/2023] [Accepted: 08/20/2023] [Indexed: 09/01/2023]
Abstract
Numerous pathogenic variants of SCN2A gene, encoding voltage-gated sodium channel α2 subunit Nav1.2 protein, have been identified in a wide spectrum of neuropsychiatric disorders including schizophrenia. However, pathological mechanisms for the schizophrenia-relevant behavioral abnormalities caused by the variants remain poorly understood. Here in this study, we characterized mouse lines with selective Scn2a deletion at schizophrenia-related brain regions, medial prefrontal cortex (mPFC) or ventral tegmental area (VTA), obtained by injecting adeno-associated viruses (AAV) expressing Cre recombinase into homozygous Scn2a-floxed (Scn2afl/fl) mice, in which expression of the Scn2a was locally deleted in the presence of Cre recombinase. The mice lacking Scn2a in the mPFC exhibited a tendency for a reduction in prepulse inhibition (PPI) in acoustic startle response. Conversely, the mice lacking Scn2a in the VTA showed a significant increase in PPI. We also found that the mice lacking Scn2a in the mPFC displayed increased sociability, decreased locomotor activity, and increased anxiety-like behavior, while the mice lacking Scn2a in the VTA did not show any other abnormalities in these parameters except for vertical activity which is one of locomotor activities. These results suggest that Scn2a-deficiencies in mPFC and VTA are inversely relevant for the schizophrenic phenotypes in patients with SCN2A variants.
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Affiliation(s)
- Toshimitsu Suzuki
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan.
| | - Satoko Hattori
- Division of Systems Medical Science, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
- Research Creation Support Center, Aichi Medical University, Nagakute, Aichi, 480-1195, Japan
| | - Hiroaki Mizukami
- Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Ryuichi Nakajima
- Division of Systems Medical Science, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Yurina Hibi
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Saho Kato
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Mahoro Matsuzaki
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Ryu Ikebe
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Kazuhiro Yamakawa
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
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9
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Brown CO, Uy JA, Murtaza N, Rosa E, Alfonso A, Dave BM, Kilpatrick S, Cheng AA, White SH, Scherer SW, Singh KK. Disruption of the autism-associated gene SCN2A alters synaptic development and neuronal signaling in patient iPSC-glutamatergic neurons. Front Cell Neurosci 2024; 17:1239069. [PMID: 38293651 PMCID: PMC10824931 DOI: 10.3389/fncel.2023.1239069] [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: 06/12/2023] [Accepted: 12/14/2023] [Indexed: 02/01/2024] Open
Abstract
SCN2A is an autism spectrum disorder (ASD) risk gene and encodes a voltage-gated sodium channel. However, the impact of ASD-associated SCN2A de novo variants on human neuron development is unknown. We studied SCN2A using isogenic SCN2A-/- induced pluripotent stem cells (iPSCs), and patient-derived iPSCs harboring a de novo R607* truncating variant. We used Neurogenin2 to generate excitatory (glutamatergic) neurons and found that SCN2A+/R607* and SCN2A-/- neurons displayed a reduction in synapse formation and excitatory synaptic activity. We found differential impact on actional potential dynamics and neuronal excitability that reveals a loss-of-function effect of the R607* variant. Our study reveals that a de novo truncating SCN2A variant impairs the development of human neuronal function.
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Affiliation(s)
- Chad O. Brown
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Jarryll A. Uy
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Nadeem Murtaza
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Elyse Rosa
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Alexandria Alfonso
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Biren M. Dave
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- SickKids Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Savannah Kilpatrick
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Annie A. Cheng
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Sean H. White
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Stephen W. Scherer
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- SickKids Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Karun K. Singh
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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10
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Schamiloglu S, Wu H, Zhou M, Kwan AC, Bender KJ. Dynamic Foraging Behavior Performance Is Not Affected by Scn2a Haploinsufficiency. eNeuro 2023; 10:ENEURO.0367-23.2023. [PMID: 38151324 PMCID: PMC10755640 DOI: 10.1523/eneuro.0367-23.2023] [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: 09/19/2023] [Revised: 10/23/2023] [Accepted: 11/14/2023] [Indexed: 12/29/2023] Open
Abstract
Dysfunction in the gene SCN2A, which encodes the voltage-gated sodium channel Nav1.2, is strongly associated with neurodevelopmental disorders including autism spectrum disorder and intellectual disability (ASD/ID). This dysfunction typically manifests in these disorders as a haploinsufficiency, where loss of one copy of a gene cannot be compensated for by the other allele. Scn2a haploinsufficiency affects a range of cells and circuits across the brain, including associative neocortical circuits that are important for cognitive flexibility and decision-making behaviors. Here, we tested whether Scn2a haploinsufficiency has any effect on a dynamic foraging task that engages such circuits. Scn2a +/- mice and wild-type (WT) littermates were trained on a choice behavior where the probability of reward between two options varied dynamically across trials and where the location of the high reward underwent uncued reversals. Despite impairments in Scn2a-related neuronal excitability, we found that both male and female Scn2a +/- mice performed these tasks as well as wild-type littermates, with no behavioral difference across genotypes in learning or performance parameters. Varying the number of trials between reversals or probabilities of receiving reward did not result in an observable behavioral difference, either. These data suggest that, despite heterozygous loss of Scn2a, mice can perform relatively complex foraging tasks that make use of higher-order neuronal circuits.
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Affiliation(s)
- Selin Schamiloglu
- Neuroscience Graduate Program, University of California, San Francisco, CA 94158
- Center for Integrative Neuroscience, Department of Neurology, University of California, San Francisco, CA 94158
| | - Hao Wu
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511
| | - Mingkang Zhou
- Neuroscience Graduate Program, University of California, San Francisco, CA 94158
- Center for Integrative Neuroscience, Department of Neurology, University of California, San Francisco, CA 94158
| | - Alex C Kwan
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
| | - Kevin J Bender
- Center for Integrative Neuroscience, Department of Neurology, University of California, San Francisco, CA 94158
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11
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Li M, Eltabbal M, Tran HD, Kuhn B. Scn2a insufficiency alters spontaneous neuronal Ca 2+ activity in somatosensory cortex during wakefulness. iScience 2023; 26:108138. [PMID: 37876801 PMCID: PMC10590963 DOI: 10.1016/j.isci.2023.108138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/22/2023] [Accepted: 10/02/2023] [Indexed: 10/26/2023] Open
Abstract
SCN2A protein-truncating variants (PTV) can result in neurological disorders such as autism spectrum disorder and intellectual disability, but they are less likely to cause epilepsy in comparison to missense variants. While in vitro studies showed PTV reduce action potential firing, consequences at in vivo network level remain elusive. Here, we generated a mouse model of Scn2a insufficiency using antisense oligonucleotides (Scn2a ASO mice), which recapitulated key clinical feature of SCN2A PTV disorders. Simultaneous two-photon Ca2+ imaging and electrocorticography (ECoG) in awake mice showed that spontaneous Ca2+ transients in somatosensory cortical neurons, as well as their pairwise co-activities were generally decreased in Scn2a ASO mice during spontaneous awake state and induced seizure state. The reduction of neuronal activities and paired co-activity are mechanisms associated with motor, social and cognitive deficits observed in our mouse model of severe Scn2a insufficiency, indicating these are likely mechanisms driving SCN2A PTV pathology.
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Affiliation(s)
- Melody Li
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Mohamed Eltabbal
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Hoang-Dai Tran
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Bernd Kuhn
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
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12
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Yang Y, Wu J, Zhang J, Chen X, Que Z, Wettschurack K, Deming B, Acosta M, Cui N, Eaton M, Zhao Y, Halurkar M, Purba M, Chen I, Xiao T, Suzuki M, Yuan C, Xu R, Koss W, Du D, Chen F, Wu LJ, Clinic M. Microglial over-pruning of synapses during development in autism-associated SCN2A-deficient mice and human cerebral organoids. RESEARCH SQUARE 2023:rs.3.rs-3270664. [PMID: 37841865 PMCID: PMC10571631 DOI: 10.21203/rs.3.rs-3270664/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Autism spectrum disorder (ASD) is a major neurodevelopmental disorder affecting 1 in 36 children in the United States. While neurons have been the focus to understand ASD, an altered neuro-immune response in the brain may be closely associated with ASD, and a neuro-immune interaction could play a role in the disease progression. As the resident immune cells of the brain, microglia regulate brain development and homeostasis via core functions including phagocytosis of synapses. While ASD has been traditionally considered a polygenic disorder, recent large-scale human genetic studies have identified SCN2A deficiency as a leading monogenic cause of ASD and intellectual disability. We generated a Scn2a-deficient mouse model, which displays major behavioral and neuronal phenotypes. However, the role of microglia in this disease model is unknown. Here, we reported that Scn2a-deficient mice have impaired learning and memory, accompanied by reduced synaptic transmission and lower spine density in neurons of the hippocampus. Microglia in Scn2a-deficient mice are partially activated, exerting excessive phagocytic pruning of post-synapses related to the complement C3 cascades during selective developmental stages. The ablation of microglia using PLX3397 partially restores synaptic transmission and spine density. To extend our findings from rodents to human cells, we established a microglial-incorporated human cerebral organoid model carrying an SCN2A protein-truncating mutation identified in children with ASD. We found that human microglia display increased elimination of post-synapse in cerebral organoids carrying the SCN2A mutation. Our study establishes a key role of microglia in multi-species autism-associated models of SCN2A deficiency from mouse to human cells.
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Affiliation(s)
- Yang Yang
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Jiaxiang Wu
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Jingliang Zhang
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Xiaoling Chen
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Zhefu Que
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Kyle Wettschurack
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Brody Deming
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Maria Acosta
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Ningren Cui
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Muriel Eaton
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Yuanrui Zhao
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Manasi Halurkar
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Mandal Purba
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
| | - Ian Chen
- Purdue University College of Pharmacy & Purdue Institute for Integrative Neuroscience (PIIN)
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13
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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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14
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Asadollahi R, Delvendahl I, Muff R, Tan G, Rodríguez DG, Turan S, Russo M, Oneda B, Joset P, Boonsawat P, Masood R, Mocera M, Ivanovski I, Baumer A, Bachmann-Gagescu R, Schlapbach R, Rehrauer H, Steindl K, Begemann A, Reis A, Winkler J, Winner B, Müller M, Rauch A. Pathogenic SCN2A variants cause early-stage dysfunction in patient-derived neurons. Hum Mol Genet 2023; 32:2192-2204. [PMID: 37010102 PMCID: PMC10281746 DOI: 10.1093/hmg/ddad048] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/23/2023] [Accepted: 03/19/2023] [Indexed: 04/04/2023] Open
Abstract
Pathogenic heterozygous variants in SCN2A, which encodes the neuronal sodium channel NaV1.2, cause different types of epilepsy or intellectual disability (ID)/autism without seizures. Previous studies using mouse models or heterologous systems suggest that NaV1.2 channel gain-of-function typically causes epilepsy, whereas loss-of-function leads to ID/autism. How altered channel biophysics translate into patient neurons remains unknown. Here, we investigated iPSC-derived early-stage cortical neurons from ID patients harboring diverse pathogenic SCN2A variants [p.(Leu611Valfs*35); p.(Arg937Cys); p.(Trp1716*)] and compared them with neurons from an epileptic encephalopathy (EE) patient [p.(Glu1803Gly)] and controls. ID neurons consistently expressed lower NaV1.2 protein levels. In neurons with the frameshift variant, NaV1.2 mRNA and protein levels were reduced by ~ 50%, suggesting nonsense-mediated decay and haploinsufficiency. In other ID neurons, only protein levels were reduced implying NaV1.2 instability. Electrophysiological analysis revealed decreased sodium current density and impaired action potential (AP) firing in ID neurons, consistent with reduced NaV1.2 levels. In contrast, epilepsy neurons displayed no change in NaV1.2 levels or sodium current density, but impaired sodium channel inactivation. Single-cell transcriptomics identified dysregulation of distinct molecular pathways including inhibition of oxidative phosphorylation in neurons with SCN2A haploinsufficiency and activation of calcium signaling and neurotransmission in epilepsy neurons. Together, our patient iPSC-derived neurons reveal characteristic sodium channel dysfunction consistent with biophysical changes previously observed in heterologous systems. Additionally, our model links the channel dysfunction in ID to reduced NaV1.2 levels and uncovers impaired AP firing in early-stage neurons. The altered molecular pathways may reflect a homeostatic response to NaV1.2 dysfunction and can guide further investigations.
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Affiliation(s)
- R Asadollahi
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
- Faculty of Engineering and Science, University of Greenwich London, Medway Campus, Chatham Maritime ME4 4TB, UK
| | - I Delvendahl
- Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
| | - R Muff
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - G Tan
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - D G Rodríguez
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - S Turan
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - M Russo
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - B Oneda
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - P Joset
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - P Boonsawat
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Masood
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - M Mocera
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - I Ivanovski
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Baumer
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Schlapbach
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - H Rehrauer
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - K Steindl
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Begemann
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - J Winkler
- Department of Molecular Neurology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
- Center for Rare Diseases Erlangen, University Hospital Erlangen, Erlangen 91054, Germany
| | - B Winner
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
- Center for Rare Diseases Erlangen, University Hospital Erlangen, Erlangen 91054, Germany
| | - M Müller
- Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
- University of Zurich Clinical Research Priority Program (CRPP) Praeclare – Personalized prenatal and reproductive medicine, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) AdaBD: Adaptive Brain Circuits in Development and Learning, Zurich 8006, Switzerland
| | - A Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
- University of Zurich Clinical Research Priority Program (CRPP) Praeclare – Personalized prenatal and reproductive medicine, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) AdaBD: Adaptive Brain Circuits in Development and Learning, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) ITINERARE: Innovative Therapies in Rare Diseases, Zurich 8006, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich 8057, Switzerland
- University Children's Hospital Zurich, University of Zurich, Zurich 8032, Switzerland
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15
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Lindquist BE, Timbie C, Voskobiynyk Y, Paz JT. Thalamocortical circuits in generalized epilepsy: Pathophysiologic mechanisms and therapeutic targets. Neurobiol Dis 2023; 181:106094. [PMID: 36990364 PMCID: PMC10192143 DOI: 10.1016/j.nbd.2023.106094] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/02/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023] Open
Abstract
Generalized epilepsy affects 24 million people globally; at least 25% of cases remain medically refractory. The thalamus, with widespread connections throughout the brain, plays a critical role in generalized epilepsy. The intrinsic properties of thalamic neurons and the synaptic connections between populations of neurons in the nucleus reticularis thalami and thalamocortical relay nuclei help generate different firing patterns that influence brain states. In particular, transitions from tonic firing to highly synchronized burst firing mode in thalamic neurons can cause seizures that rapidly generalize and cause altered awareness and unconsciousness. Here, we review the most recent advances in our understanding of how thalamic activity is regulated and discuss the gaps in our understanding of the mechanisms of generalized epilepsy syndromes. Elucidating the role of the thalamus in generalized epilepsy syndromes may lead to new opportunities to better treat pharmaco-resistant generalized epilepsy by thalamic modulation and dietary therapy.
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Affiliation(s)
- Britta E Lindquist
- UCSF Department of Neurology, Division of Neurocritical Care, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Clare Timbie
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America; Kavli Institute for Fundamental Neuroscience, UCSF, United States of America.
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16
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Wang L, Wang B, Wu C, Wang J, Sun M. Autism Spectrum Disorder: Neurodevelopmental Risk Factors, Biological Mechanism, and Precision Therapy. Int J Mol Sci 2023; 24:ijms24031819. [PMID: 36768153 PMCID: PMC9915249 DOI: 10.3390/ijms24031819] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
Autism spectrum disorder (ASD) is a heterogeneous, behaviorally defined neurodevelopmental disorder. Over the past two decades, the prevalence of autism spectrum disorders has progressively increased, however, no clear diagnostic markers and specifically targeted medications for autism have emerged. As a result, neurobehavioral abnormalities, neurobiological alterations in ASD, and the development of novel ASD pharmacological therapy necessitate multidisciplinary collaboration. In this review, we discuss the development of multiple animal models of ASD to contribute to the disease mechanisms of ASD, as well as new studies from multiple disciplines to assess the behavioral pathology of ASD. In addition, we summarize and highlight the mechanistic advances regarding gene transcription, RNA and non-coding RNA translation, abnormal synaptic signaling pathways, epigenetic post-translational modifications, brain-gut axis, immune inflammation and neural loop abnormalities in autism to provide a theoretical basis for the next step of precision therapy. Furthermore, we review existing autism therapy tactics and limits and present challenges and opportunities for translating multidisciplinary knowledge of ASD into clinical practice.
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17
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Hu X, Jing M, Wang Y, Liu Y, Hua Y. Functional analysis of a novel de novo SCN2A variant in a patient with seizures refractory to oxcarbazepine. Front Mol Neurosci 2023; 16:1159649. [PMID: 37152433 PMCID: PMC10158977 DOI: 10.3389/fnmol.2023.1159649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/29/2023] [Indexed: 05/09/2023] Open
Abstract
Objective We admitted a female patient with infantile onset epilepsy (<3-month-old). The use of oxcarbazepine exacerbated epileptic seizures in the patient. In the present study, we aimed to identify the genetic basis of the infantile onset epilepsy in the patient, and determine the correlations among genotype, phenotype, and clinical drug response. Methods We described the clinical characteristics of an infant with refractory epilepsy. Whole exome sequencing (WES) was used to screen for the pathogenic variant. Whole-cell patch-clamp was performed to determine functional outcomes of the variant. Results WES identified a novel de novo SCN2A variant (c.468 G > C, p.K156N) in the patient. In comparison with wildtype, electrophysiology revealed that SCN2A-K156N variant in transfected cells demonstrated reduced sodium current density, delayed activation and accelerated inactivation process of Na+ channel, all of which suggested a loss-of-function (LOF) of Nav1.2 channel. Conclusion We showed the importance of functional analysis for a SCN2A variant with unknown significance to determine pathogenicity, drug reactions, and genotype-phenotype correlations. For patients suffering from early infantile epilepsies, the use of oxcarbazepine in some SCN2A-related epilepsies requires vigilance to assess the possibility of epilepsy worsening.
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Affiliation(s)
- Xiaoyue Hu
- Department of Neurology, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, China
| | - Miao Jing
- Department of Neurology, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, China
| | - Yanping Wang
- Department of Neurology, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, China
| | - Yanshan Liu
- Department of Pediatric Laboratory, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, China
- *Correspondence: Yanshan Liu,
| | - Ying Hua
- Department of Neurology, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, China
- Ying Hua,
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18
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Johannesen KM, Liu Y, Koko M, Gjerulfsen CE, Sonnenberg L, Schubert J, Fenger CD, Eltokhi A, Rannap M, Koch NA, Lauxmann S, Krüger J, Kegele J, Canafoglia L, Franceschetti S, Mayer T, Rebstock J, Zacher P, Ruf S, Alber M, Sterbova K, Lassuthová P, Vlckova M, Lemke JR, Platzer K, Krey I, Heine C, Wieczorek D, Kroell-Seger J, Lund C, Klein KM, Au PYB, Rho JM, Ho AW, Masnada S, Veggiotti P, Giordano L, Accorsi P, Hoei-Hansen CE, Striano P, Zara F, Verhelst H, Verhoeven JS, Braakman HMH, van der Zwaag B, Harder AVE, Brilstra E, Pendziwiat M, Lebon S, Vaccarezza M, Le NM, Christensen J, Grønborg S, Scherer SW, Howe J, Fazeli W, Howell KB, Leventer R, Stutterd C, Walsh S, Gerard M, Gerard B, Matricardi S, Bonardi CM, Sartori S, Berger A, Hoffman-Zacharska D, Mastrangelo M, Darra F, Vøllo A, Motazacker MM, Lakeman P, Nizon M, Betzler C, Altuzarra C, Caume R, Roubertie A, Gélisse P, Marini C, Guerrini R, Bilan F, Tibussek D, Koch-Hogrebe M, Perry MS, Ichikawa S, Dadali E, Sharkov A, Mishina I, Abramov M, Kanivets I, Korostelev S, Kutsev S, Wain KE, Eisenhauer N, Wagner M, Savatt JM, Müller-Schlüter K, Bassan H, Borovikov A, Nassogne MC, Destrée A, Schoonjans AS, Meuwissen M, Buzatu M, Jansen A, Scalais E, Srivastava S, Tan WH, Olson HE, Loddenkemper T, Poduri A, Helbig KL, Helbig I, Fitzgerald MP, Goldberg EM, Roser T, Borggraefe I, Brünger T, May P, Lal D, Lederer D, Rubboli G, Heyne HO, Lesca G, Hedrich UBS, Benda J, Gardella E, Lerche H, Møller RS. Genotype-phenotype correlations in SCN8A-related disorders reveal prognostic and therapeutic implications. Brain 2022; 145:2991-3009. [PMID: 34431999 PMCID: PMC10147326 DOI: 10.1093/brain/awab321] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/24/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel Nav1.6, with the aim of describing clinical phenotypes related to functional effects. Six different clinical subgroups were identified: Group 1, benign familial infantile epilepsy (n = 15, normal cognition, treatable seizures); Group 2, intermediate epilepsy (n = 33, mild intellectual disability, partially pharmaco-responsive); Group 3, developmental and epileptic encephalopathy (n = 177, severe intellectual disability, majority pharmaco-resistant); Group 4, generalized epilepsy (n = 20, mild to moderate intellectual disability, frequently with absence seizures); Group 5, unclassifiable epilepsy (n = 127); and Group 6, neurodevelopmental disorder without epilepsy (n = 20, mild to moderate intellectual disability). Those in Groups 1-3 presented with focal or multifocal seizures (median age of onset: 4 months) and focal epileptiform discharges, whereas the onset of seizures in patients with generalized epilepsy was later (median: 42 months) with generalized epileptiform discharges. We performed functional studies expressing missense variants in ND7/23 neuroblastoma cells and primary neuronal cultures using recombinant tetrodotoxin-insensitive human Nav1.6 channels and whole-cell patch-clamping. Two variants causing developmental and epileptic encephalopathy showed a strong gain-of-function (hyperpolarizing shift of steady-state activation, strongly increased neuronal firing rate) and one variant causing benign familial infantile epilepsy or intermediate epilepsy showed a mild gain-of-function (defective fast inactivation, less increased firing). In contrast, all three variants causing generalized epilepsy induced a loss-of-function (reduced current amplitudes, depolarizing shift of steady-state activation, reduced neuronal firing). Functional effects were known for 170 individuals. All 136 individuals carrying a functionally tested gain-of-function variant had either focal (n = 97, Groups 1-3) or unclassifiable (n = 39) epilepsy, whereas 34 individuals with a loss-of-function variant had either generalized (n = 14), no (n = 11) or unclassifiable (n = 6) epilepsy; only three had developmental and epileptic encephalopathy. Computational modelling in the gain-of-function group revealed a significant correlation between the severity of the electrophysiological and clinical phenotypes. Gain-of-function variant carriers responded significantly better to sodium channel blockers than to other anti-seizure medications, and the same applied for all individuals in Groups 1-3. In conclusion, our data reveal clear genotype-phenotype correlations between age at seizure onset, type of epilepsy and gain- or loss-of-function effects of SCN8A variants. Generalized epilepsy with absence seizures is the main epilepsy phenotype of loss-of-function variant carriers and the extent of the electrophysiological dysfunction of the gain-of-function variants is a main determinant of the severity of the clinical phenotype in focal epilepsies. Our pharmacological data indicate that sodium channel blockers present a treatment option in SCN8A-related focal epilepsy with onset in the first year of life.
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Affiliation(s)
- Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, 5230 Odense, Denmark
| | - Yuanyuan Liu
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Cathrine E Gjerulfsen
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
| | - Lukas Sonnenberg
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
- Institute for Neurobiology, University of Tuebingen, 72072 Tuebingen, Germany
| | - Julian Schubert
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Christina D Fenger
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
| | - Ahmed Eltokhi
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Maert Rannap
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Nils A Koch
- Institute for Neurobiology, University of Tuebingen, 72072 Tuebingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
- Institute for Neurobiology, University of Tuebingen, 72072 Tuebingen, Germany
| | - Johanna Krüger
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Josua Kegele
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Laura Canafoglia
- Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologio Carlo Besta, 20125 Milan, Italy
| | - Silvana Franceschetti
- Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologio Carlo Besta, 20125 Milan, Italy
| | - Thomas Mayer
- Epilepsy Center Kleinwachau, 01454 Dresden-Radeberg, Germany
| | | | - Pia Zacher
- Epilepsy Center Kleinwachau, 01454 Dresden-Radeberg, Germany
| | - Susanne Ruf
- Department of Pediatric Neurology and Developmental Medicine, University Children’s Hospital, 72072 Tuebingen, Germany
| | - Michael Alber
- Department of Pediatric Neurology and Developmental Medicine, University Children’s Hospital, 72072 Tuebingen, Germany
| | - Katalin Sterbova
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 10000 Prague, Czech Republic
| | - Petra Lassuthová
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 10000 Prague, Czech Republic
| | - Marketa Vlckova
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 10000 Prague, Czech Republic
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 4275 Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 4275 Leipzig, Germany
| | - Ilona Krey
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 4275 Leipzig, Germany
| | - Constanze Heine
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 4275 Leipzig, Germany
| | - Dagmar Wieczorek
- Institute of Human Genetics, University Clinic, Heinrich-Heine-University, 40210 Düsseldorf, Germany
| | - Judith Kroell-Seger
- Children’s Department, Swiss Epilepsy Centre, Clinic Lengg, 8001 Zurich, Switzerland
| | - Caroline Lund
- National Centre for Rare Epilepsy-Related Disorders, Oslo University Hospital, 0001 Oslo, Norway
| | - Karl Martin Klein
- Departments of Clinical Neurosciences, Medical Genetics and Community Health Sciences, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2P 0A1, Canada
| | - P Y Billie Au
- Department of Medical Genetics, Alberta Children’s Hospital Research Institute, University of Calgary, AB T6G 2T4, Canada
| | - Jong M Rho
- Section of Pediatric Neurology, Alberta Children’s Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB T2P 0A1, Canada
| | - Alice W Ho
- Section of Pediatric Neurology, Alberta Children’s Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB T2P 0A1, Canada
| | - Silvia Masnada
- Department of Child Neurology, V. Buzzi Children’s Hospital, 20125 Milan, Italy
| | - Pierangelo Veggiotti
- Department of Child Neurology, V. Buzzi Children’s Hospital, 20125 Milan, Italy
- ‘L. Sacco’ Department of Biomedical and Clinical Sciences, University of Milan, 20157 Milan, Italy
| | - Lucio Giordano
- Child Neuropsychiatric Unit, Civilian Hospital, 25100 Brescia, Italy
| | - Patrizia Accorsi
- Child Neuropsychiatric Unit, Civilian Hospital, 25100 Brescia, Italy
| | - Christina E Hoei-Hansen
- Department of Pediatrics, Copenhagen University Hospital Rigshospitalet, 2200 Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16121 Genova, Italy
- IRCCS ‘G. Gaslini’ Institute, 16121 Genoa, Italy
| | | | - Helene Verhelst
- Department of Pediatrics, Division of Pediatric Neurology, Gent University Hospital, 9042 Gent, Belgium
| | - Judith S Verhoeven
- Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, 5591 Heeze, The Netherlands
| | - Hilde M H Braakman
- Department of Pediatric Neurology, Amalia Children’s Hospital, Radboud University Medical Center, 6525 Nijmegen, The Netherlands
| | - Bert van der Zwaag
- Department of Genetics, University Medical Center Utrecht, Utrecht University, 3553 Utrecht, The Netherlands
| | - Aster V E Harder
- Department of Genetics, University Medical Center Utrecht, Utrecht University, 3553 Utrecht, The Netherlands
| | - Eva Brilstra
- Department of Genetics, University Medical Center Utrecht, Utrecht University, 3553 Utrecht, The Netherlands
| | - Manuela Pendziwiat
- Department of Neuropediatrics, Universitätsklinikum Schleswig Holstein Campus Kiel, 24106 Kiel, Germany
| | - Sebastian Lebon
- Pediatric Neurology and Neurorehabilitation Unit, Woman Mother Child Department, Lausanne University Hospital (CHUV), 1000 Lausanne, Switzerland
- University of Lausanne, 1000 Lausanne, Switzerland
| | - Maria Vaccarezza
- Department of Pediatric Neurology, Hospital Italiano de Buenos Aires, C1428 Buenos Aires, Argentina
| | - Ngoc Minh Le
- Center for Pediatric Neurology, Cleveland Clinic, Cleveland, OH 44102, USA
| | - Jakob Christensen
- Department of Neurology, Aarhus University Hospital, 8000 Aarhus, Denmark
| | - Sabine Grønborg
- Center for Rare Diseases, Department of Pediatrics and Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, 2200 Copenhagen, Denmark
| | - Stephen W Scherer
- McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON 66777, Canada
- The Centre for Applied Genomics and Department of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON 66777, Canada
| | - Jennifer Howe
- Department of Neuropediatrics, University Hospital Bonn, 53229 Bonn, Germany
| | - Walid Fazeli
- Institute for Molecular and Behavioral Neuroscience, University of Cologne, 50667 Cologne, Germany
- Neurology Department, The Royal Children’s Hospital Melbourne, 3002 Melbourne, Australia
| | - Katherine B Howell
- Neurology Department, The Royal Children’s Hospital Melbourne, 3002 Melbourne, Australia
- Murdoch Children’s Research Institute, 3052 Parkville, Australia
- Department of Pediatrics, University of Melbourne, Royal Children’s Hospital, 3052 Parkville, Australia
| | - Richard Leventer
- Neurology Department, The Royal Children’s Hospital Melbourne, 3002 Melbourne, Australia
- Murdoch Children’s Research Institute, 3052 Parkville, Australia
- Department of Pediatrics, University of Melbourne, Royal Children’s Hospital, 3052 Parkville, Australia
| | - Chloe Stutterd
- Murdoch Children’s Research Institute, 3052 Parkville, Australia
- Department of Pediatrics, University of Melbourne, Royal Children’s Hospital, 3052 Parkville, Australia
| | - Sonja Walsh
- Department of Neuropediatrics, Children’s Hospital, University Hospital Carl Gustav Carus, Technical University, 1099 Dresden, Germany
| | - Marion Gerard
- Genetics Department, CHU Côte de Nacre, 14118 Caen, France
| | | | - Sara Matricardi
- Child Neurology and Psychiatry Unit, Children’s Hospital G. Salesi, 60121 Ancona, Italy
| | - Claudia M Bonardi
- Department of Woman’s and Child’s Health, Padova University Hospital, 35100 Padova, Italy
| | - Stefano Sartori
- Child Neurology and Clinical Neurophysiology Unit, Padova University Hospital, 35100 Padova, Italy
| | - Andrea Berger
- Department of Neuropediatrics, Klinikum Weiden, Kliniken Nordoberpfalz AG, 92637 Weiden, Germany
| | | | - Massimo Mastrangelo
- Pediatric Neurology Unit, Vittore Buzzi Hospital, ASST Fatebenefratelli Sacco, 20100 Milan, Italy
| | - Francesca Darra
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37121 Verona, Italy
| | - Arve Vøllo
- Department of Pediatrics, Oestfold Hospital, 1712 Graalum, Norway
| | - M Mahdi Motazacker
- Laboratory of Genome Diagnostics, Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, 1019 Amsterdam, Netherlands
| | - Phillis Lakeman
- Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, 1019 Amsterdam, Netherlands
| | - Mathilde Nizon
- Service de Génétique Médicale, CHU Nantes, 44093 Nantes, France
| | - Cornelia Betzler
- Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schön Klinik, 83569 Vogtareuth, Germany
- Research Institute ‘Rehabilitation, Transition, Palliation’, PMU Salzburg, 5020 Salzburg, Austria
| | - Cecilia Altuzarra
- Department of Pediatrics, St. Jacques Hospital, 25000 Besançon, France
| | - Roseline Caume
- Clinique de Génétique Guy Fontaine, CHU Lille, 59000, Lille, France
| | - Agathe Roubertie
- Département de Neuropédiatrie, INSERM, CHU Montpellier, 34000 Montpellier, France
| | - Philippe Gélisse
- Département de Neuropédiatrie, INSERM, CHU Montpellier, 34000 Montpellier, France
| | - Carla Marini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children’s Hospital, University of Florence, 50131 Florence, Italy
| | | | - Frederic Bilan
- Service de Génétique, Centre Hospitalier Universitaire de Poitiers, 86021 Poitiers, France
| | - Daniel Tibussek
- Child Neurology, Center for Pediatric and Teenage Health Care, 53757 Sankt Augustin, Germany
| | | | - M Scott Perry
- Justin Neurosciences Center, Cook Children’s Medical Center, Fort Worth, TX 76101, USA
| | - Shoji Ichikawa
- Department of Clinical Diagnostics, Ambry Genetics, Aliso Viejo, CA 92637, USA
| | - Elena Dadali
- Research Centre for Medical Genetics, 115522 Moscow, Russia
- Veltischev Research and Clinical Institute for Pediatrics, Pirogov Russian National Research Medical University, 125412 Moscow, Russia
| | - Artem Sharkov
- Veltischev Research and Clinical Institute for Pediatrics, Pirogov Russian National Research Medical University, 125412 Moscow, Russia
- Genomed Ltd., 100000 Moscow, Russia
| | - Irina Mishina
- Research Centre for Medical Genetics, 115522 Moscow, Russia
| | - Mikhail Abramov
- Veltischev Research and Clinical Institute for Pediatrics, Pirogov Russian National Research Medical University, 125412 Moscow, Russia
| | - Ilya Kanivets
- Svt. Luka’s Institute of Child Neurology & Epilepsy, 100000 Moscow, Russia
- Russian Medical Academy of Continuous Professional Education, 100000 Moscow, Russia
| | - Sergey Korostelev
- Svt. Luka’s Institute of Child Neurology & Epilepsy, 100000 Moscow, Russia
- I.M. Sechenov First Moscow State Medical University, 100000 Moscow, Russia
| | - Sergey Kutsev
- Research Centre for Medical Genetics, 115522 Moscow, Russia
| | - Karen E Wain
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Nancy Eisenhauer
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Monisa Wagner
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Juliann M Savatt
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Karen Müller-Schlüter
- Epilepsy Center for Children, University Hospital Neuruppin, Brandenburg Medical School, 16816 Neuruppin, Germany
| | - Haim Bassan
- Pediatric Neurology & Development Center, Shamir Medical Center (Assaf Harofe), Be'er Ya'akov, Israel
- Sackler Faculty of Medicine, Tel Aviv University, 5296001 Tel Aviv, Israel
| | | | - Marie Cecile Nassogne
- Pediatric Neurology Unit, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, 1000 Brussels, Belgium
| | - Anne Destrée
- Institute for Pathology and Genetics, 6040 Gosselies, Belgium
| | - An Sofie Schoonjans
- Department of Pediatrics and Pediatric Neurology, Antwerp University Hospital, University of Antwerp, 2650 Edegem, Belgium
| | - Marije Meuwissen
- Pediatric Neurology, Marie Curie Hospital—CHU Charleroi, 6032 Charleroi, Belgium
| | - Marga Buzatu
- Pediatric Neurology, Marie Curie Hospital—CHU Charleroi, 6032 Charleroi, Belgium
| | - Anna Jansen
- Pediatric Neurology Unit, Department of Pediatrics, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Emmanuel Scalais
- Pediatric Neurology Unit, Department of Pediatrics, Centre Hospitalier de Luxembourg, 1313 Luxembourg, Luxembourg
| | - Siddharth Srivastava
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02108, USA
| | - Wen Hann Tan
- Department of Genetics, Boston Children’s Hospital, Boston, MA 02108, USA
| | - Heather E Olson
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02108, USA
- Epilepsy Genetics Program, Boston Children’s Hospital, Boston, MA 02108, USA
| | - Tobias Loddenkemper
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02108, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02108, USA
- Epilepsy Genetics Program, Boston Children’s Hospital, Boston, MA 02108, USA
| | - Katherine L Helbig
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy Neurogenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ingo Helbig
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy Neurogenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA
- Institute of Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
- Department of Neuropediatrics, Kiel University, 24105 Kiel, Germany
| | - Mark P Fitzgerald
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy Neurogenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Institute of Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
| | - Ethan M Goldberg
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy Neurogenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Timo Roser
- Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, Dr. von Haunersches Children’s Hospital, Ludwig-Maximilian-University of Munich, 80331 Munich, Germany
| | - Ingo Borggraefe
- Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, Dr. von Haunersches Children’s Hospital, Ludwig-Maximilian-University of Munich, 80331 Munich, Germany
- Comprehensive Epilepsy Center, Ludwig-Maximilian- University of Munich, 80331 Munich, Germany
| | - Tobias Brünger
- Luxembourg Centre for Systems Biomedicine (LCSB), University Luxembourg, L-4243 Esch-sur-Alzette, Luxembourg
| | - Patrick May
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44102, USA
| | - Dennis Lal
- Luxembourg Centre for Systems Biomedicine (LCSB), University Luxembourg, L-4243 Esch-sur-Alzette, Luxembourg
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44102, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T., Cambridge, MA 02138, USA
- Cologne Center for Genomics (CCG), University of Cologne, 50667 Cologne, Germany
| | - Damien Lederer
- Institute for Pathology and Genetics, 6040 Gosselies, Belgium
| | - Guido Rubboli
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
- University of Copenhagen, 2200 Copenhagen, Denmark
| | - Henrike O Heyne
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 4275 Leipzig, Germany
- Finnish Institute for Molecular Medicine (FIMM), University of Helsinki, 320 Helsinki, Finland
- Program for Medical and Population Genetics/Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02138, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02108, USA
| | - Gaetan Lesca
- Department of Medical Genetics, Groupement Hospitalier Est and ERN EpiCARE, University Hospitals of Lyon (HCL), 69001 Lyon, France
- Institut Neuromyogène, CNRS UMR 5310 - INSERM U1217, Université de Lyon, Université Claude Bernard Lyon 1, 69001 Lyon, France
| | - Ulrike B S Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Jan Benda
- Institute for Neurobiology, University of Tuebingen, 72072 Tuebingen, Germany
| | - Elena Gardella
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, 5230 Odense, Denmark
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72072 Tuebingen, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Center, 4293 Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, 5230 Odense, Denmark
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19
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Ma Z, Eaton M, Liu Y, Zhang J, Chen X, Tu X, Shi Y, Que Z, Wettschurack K, Zhang Z, Shi R, Chen Y, Kimbrough A, Lanman NA, Schust L, Huang Z, Yang Y. Deficiency of autism-related Scn2a gene in mice disrupts sleep patterns and circadian rhythms. Neurobiol Dis 2022; 168:105690. [PMID: 35301122 PMCID: PMC9018617 DOI: 10.1016/j.nbd.2022.105690] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/21/2022] [Accepted: 03/09/2022] [Indexed: 02/06/2023] Open
Abstract
Autism spectrum disorder (ASD) affects ~2% of the population in the US, and monogenic forms of ASD often result in the most severe manifestation of the disorder. Recently, SCN2A has emerged as a leading gene associated with ASD, of which abnormal sleep pattern is a common comorbidity. SCN2A encodes the voltage-gated sodium channel NaV1.2. Predominantly expressed in the brain, NaV1.2 mediates the action potential firing of neurons. Clinical studies found that a large portion of children with SCN2A deficiency have sleep disorders, which severely impact the quality of life of affected individuals and their caregivers. The underlying mechanism of sleep disturbances related to NaV1.2 deficiency, however, is not known. Using a gene-trap Scn2a-deficient mouse model (Scn2atrap), we found that Scn2a deficiency results in increased wakefulness and reduced non-rapid-eye-movement (NREM) sleep. Brain region-specific Scn2a deficiency in the suprachiasmatic nucleus (SCN) containing region, which is involved in circadian rhythms, partially recapitulates the sleep disturbance phenotypes. At the cellular level, we found that Scn2a deficiency disrupted the firing pattern of spontaneously firing neurons in the SCN region. At the molecular level, RNA-sequencing analysis revealed differentially expressed genes in the circadian entrainment pathway including core clock genes Per1 and Per2. Performing a transcriptome-based compound discovery, we identified dexanabinol (HU-211), a putative glutamate receptor modulator, that can partially reverse the sleep disturbance in mice. Overall, our study reveals possible molecular and cellular mechanisms underlying Scn2a deficiency-related sleep disturbances, which may inform the development of potential pharmacogenetic interventions for the affected individuals.
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Affiliation(s)
- Zhixiong Ma
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Muriel Eaton
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Yushuang Liu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Jingliang Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Xiaoling Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Xinyu Tu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yiqiang Shi
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Zhefu Que
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Kyle Wettschurack
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA
| | - Zaiyang Zhang
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA
| | - Riyi Shi
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA
| | - Yueyi Chen
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA
| | - Adam Kimbrough
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA
| | - Nadia A Lanman
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA
| | - Leah Schust
- FamilieSCN2A Foundation, P.O. Box 82, East Longmeadow, MA 01028, USA
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China.
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy & Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47906, USA.
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20
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Genetics and gene therapy in Dravet syndrome. Epilepsy Behav 2022; 131:108043. [PMID: 34053869 DOI: 10.1016/j.yebeh.2021.108043] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/02/2021] [Accepted: 05/02/2021] [Indexed: 12/17/2022]
Abstract
Dravet syndrome is a well-established electro-clinical condition first described in 1978. A main genetic cause was identified with the discovery of a loss-of-function SCN1A variant in 2001. Mechanisms underlying the phenotypic variations have subsequently been a main topic of research. Various genetic modifiers of clinical severities have been elucidated through many rigorous studies on genotype-phenotype correlations and the recent advances in next generation sequencing technology. Furthermore, a deeper understanding of the regulation of gene expression and remarkable progress on genome-editing technology using the CRISPR-Cas9 system provide significant opportunities to overcome hurdles of gene therapy, such as enhancing NaV1.1 expression. This article reviews the current understanding of genetic pathology and the status of research toward the development of gene therapy for Dravet syndrome. This article is part of the Special Issue "Severe Infantile Epilepsies".
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21
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Mangano GD, Fontana A, Antona V, Salpietro V, Mangano GR, Giuffrè M, Nardello R. Commonalities and distinctions between two neurodevelopmental disorder subtypes associated with SCN2A and SCN8A variants and literature review. Mol Genet Genomic Med 2022; 10:e1911. [PMID: 35348308 PMCID: PMC9034667 DOI: 10.1002/mgg3.1911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/02/2022] [Accepted: 02/07/2022] [Indexed: 01/29/2023] Open
Abstract
This study was aimed to analyze the commonalities and distinctions of voltage‐gated sodium channels, Nav1.2, Nav1.6, in neurodevelopmental disorders. An observational study was performed including two patients with neurodevelopmental disorders. The demographic, electroclinical, genetic, and neuropsychological characteristics were analyzed and compared with each other and then with the subjects carrying the same genetic variants reported in the literature. The clinical features of one of them argued for autism spectrum disorder and developmental delay, the other for intellectual disability, diagnoses confirmed by the neuropsychological assessment. The first patient was a carrier of SCN2A (p.R379H) variant while the second was carrier of SCN8A (p.E936K) variant, both involving the pore loop of the two channels. The results of this study suggest that the neurodevelopmental disorders without overt epilepsy of both patients can be the consequences of loss of function of Nav1.2/Nav1.6 channels. Notably, the SCN2A variant, with an earlier expression timing in brain development, resulted in a more severe phenotype as autism spectrum disorder and developmental delay, while the SCN8A variant, with a later expression timing, resulted in a less severe phenotype as intellectual disability.
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Affiliation(s)
- Giuseppe Donato Mangano
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Antonina Fontana
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Vincenzo Antona
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Vincenzo Salpietro
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.,Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa; Pediatric Neurology and Muscular Diseases Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy
| | - Giuseppa Renata Mangano
- Department of Psychology, Educational Sciences and Human Movement, University of Palermo, Palermo, Italy
| | - Mario Giuffrè
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Rosaria Nardello
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro," University of Palermo, Palermo, Italy
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22
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Antoine MW. Paradoxical Hyperexcitability in Disorders of Neurodevelopment. Front Mol Neurosci 2022; 15:826679. [PMID: 35571370 PMCID: PMC9102973 DOI: 10.3389/fnmol.2022.826679] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/14/2022] [Indexed: 01/29/2023] Open
Abstract
Autism Spectrum Disorder (ASD), Rett syndrome (RTT) and Angelman Syndrome (AS) are neurodevelopmental disorders (NDDs) that share several clinical characteristics, including displays of repetitive movements, developmental delays, language deficits, intellectual disability, and increased susceptibility to epilepsy. While several reviews address the biological basis of non-seizure-related ASD phenotypes, here, I highlight some shared biological mechanisms that may contribute to increased seizure susceptibility. I focus on genetic studies identifying the anatomical origin of the seizure phenotype in loss-of-function, monogenic, mouse models of these NDDs, combined with insights gained from complementary studies quantifying levels of synaptic excitation and inhibition. Epilepsy is characterized by a sudden, abnormal increase in synchronous activity within neuronal networks, that is posited to arise from excess excitation, largely driven by reduced synaptic inhibition. Primarily for this reason, elevated network excitability is proposed to underlie the causal basis for the ASD, RTT, and AS phenotypes. Although, mouse models of these disorders replicate aspects of the human condition, i.e., hyperexcitability discharges or seizures on cortical electroencephalograms, measures at the synaptic level often reveal deficits in excitatory synaptic transmission, rather than too much excitation. Resolving this apparent paradox has direct implications regarding expected outcomes of manipulating GABAergic tone. In particular, in NDDs associated with seizures, cortical circuits can display reduced, rather than normal or increased levels of synaptic excitation, and therefore suggested treatments aimed at increasing inhibition could further promote hypoactivity instead of normality. In this review, I highlight shared mechanisms across animal models for ASD, RTT, and AS with reduced synaptic excitation that nevertheless promote hyperexcitability in cortical circuits.
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Affiliation(s)
- Michelle W. Antoine
- Section on Neural Circuits, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
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23
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Nadella N, Ghosh A, Chu XP. Hyperexcitability in adult mice with severe deficiency in Na V1.2 channels. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2022; 14:55-59. [PMID: 35310859 PMCID: PMC8918607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
Epilepsy is one of the most common neurological diseases. Epileptic individuals are faced with seizures, which are largely caused by enhanced neuronal excitability and/or decreased neuronal inhibitory activity. SCN2A encodes a neuronal voltage-gated sodium channel, NaV1.2 that is primarily found in excitatory neurons throughout the brain. NaV1.2 is most concentrated within the principal neurons of the corticostriatal circuit, which includes pyramidal neurons in the medial prefrontal cortex and medium spiny neurons in the striatum. In the early stage of adult development, the NaV1.2 channel plays critical roles in generation and propagation of action potentials in these neurons. Gain of Function variants of SCN2A results in unprovoked seizures and epilepsy, while loss-of-function variants of SCN2A is a leading cause for autism spectrum disorder as well as intellectual disability. Previous studies have shown that full deletion of Scn2a gene in mice is lethal and partial disruption of Scn2a gene (less than 50%) leads to inhibition of neuronal excitability. A recent study from Dr. Yang's laboratory revealed an unexpected result from mice with severe NaV1.2 deficiency and they demonstrated that severe deletion of Scn2a gene (around 68% gene disruption) in NaV1.2 triggers neuronal hyperexcitability in adult mice. Their findings may explain the puzzling clinical observation that certain individuals with NaV1.2 deficiency still develop unprovoked seizure. With the knowledge that using sodium-channel blockers simply exacerbates the seizure, the need for understanding the intrinsic nature of the NaV1.2 channel provides an important research topic in the future.
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Affiliation(s)
- Nitin Nadella
- Department of Biomedical Sciences, University of Missouri-Kansas City School of Medicine Kansas City, Missouri, MO 64108, USA
| | - Arkadeep Ghosh
- Department of Biomedical Sciences, University of Missouri-Kansas City School of Medicine Kansas City, Missouri, MO 64108, USA
| | - Xiang-Ping Chu
- Department of Biomedical Sciences, University of Missouri-Kansas City School of Medicine Kansas City, Missouri, MO 64108, USA
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24
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Panagiotakos G, Pasca SP. A matter of space and time: Emerging roles of disease-associated proteins in neural development. Neuron 2022; 110:195-208. [PMID: 34847355 PMCID: PMC8776599 DOI: 10.1016/j.neuron.2021.10.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/11/2021] [Accepted: 10/25/2021] [Indexed: 01/21/2023]
Abstract
Recent genetic studies of neurodevelopmental disorders point to synaptic proteins and ion channels as key contributors to disease pathogenesis. Although many of these proteins, such as the L-type calcium channel Cav1.2 or the postsynaptic scaffolding protein SHANK3, have well-studied functions in mature neurons, new evidence indicates that they may subserve novel, distinct roles in immature cells as the nervous system is assembled in prenatal development. Emerging tools and technologies, including single-cell sequencing and human cellular models of disease, are illuminating differential isoform utilization, spatiotemporal expression, and subcellular localization of ion channels and synaptic proteins in the developing brain compared with the adult, providing new insights into the regulation of developmental processes. We propose that it is essential to consider the temporally distinct and cell-specific roles of these proteins during development and maturity in our framework for understanding neuropsychiatric disorders.
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Affiliation(s)
- Georgia Panagiotakos
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA.
| | - Sergiu P Pasca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
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25
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Li M, Jancovski N, Jafar-Nejad P, Burbano LE, Rollo B, Richards K, Drew L, Sedo A, Heighway J, Pachernegg S, Soriano A, Jia L, Blackburn T, Roberts B, Nemiroff A, Dalby K, Maljevic S, Reid CA, Rigo F, Petrou S. Antisense oligonucleotide therapy reduces seizures and extends life span in an SCN2A gain-of-function epilepsy model. J Clin Invest 2021; 131:152079. [PMID: 34850743 DOI: 10.1172/jci152079] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 10/01/2021] [Indexed: 01/21/2023] Open
Abstract
De novo variation in SCN2A can give rise to severe childhood disorders. Biophysical gain of function in SCN2A is seen in some patients with early seizure onset developmental and epileptic encephalopathy (DEE). In these cases, targeted reduction in SCN2A expression could substantially improve clinical outcomes. We tested this theory by central administration of a gapmer antisense oligonucleotide (ASO) targeting Scn2a mRNA in a mouse model of Scn2a early seizure onset DEE (Q/+ mice). Untreated Q/+ mice presented with spontaneous seizures at P1 and did not survive beyond P30. Administration of the ASO to Q/+ mice reduced spontaneous seizures and significantly extended life span. Across a range of behavioral tests, Scn2a ASO-treated Q/+ mice were largely indistinguishable from WT mice, suggesting treatment is well tolerated. A human SCN2A gapmer ASO could likewise impact the lives of patients with SCN2A gain-of-function DEE.
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Affiliation(s)
- Melody Li
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Nikola Jancovski
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | | | - Lisseth E Burbano
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Ben Rollo
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Kay Richards
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Lisa Drew
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Alicia Sedo
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Jacqueline Heighway
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Svenja Pachernegg
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | | | - Linghan Jia
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Todd Blackburn
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,RogCon Biosciences, Miami Beach, Florida, USA
| | - Blaine Roberts
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Alex Nemiroff
- RogCon Biosciences, Miami Beach, Florida, USA.,Praxis Precision Medicines, Boston, Massachusetts, USA
| | - Kelley Dalby
- RogCon Biosciences, Miami Beach, Florida, USA.,Praxis Precision Medicines, Boston, Massachusetts, USA
| | - Snezana Maljevic
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,RogCon Biosciences, Miami Beach, Florida, USA.,Praxis Precision Medicines, Boston, Massachusetts, USA
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26
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Miralles RM, Patel MK. It Takes Two to Tango: Channel Interplay Leads to Paradoxical Hyperexcitability in a Loss-of-Function Epilepsy Variant. Epilepsy Curr 2021; 22:69-71. [PMID: 35233206 PMCID: PMC8832357 DOI: 10.1177/15357597211057966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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27
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Yamano R, Miyazaki H, Nukina N. The diffuse distribution of Nav1.2 on mid-axonal regions is a marker for unmyelinated fibers in the central nervous system. Neurosci Res 2021; 177:145-150. [PMID: 34808247 DOI: 10.1016/j.neures.2021.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/25/2022]
Abstract
Unmyelinated fibers in the central nervous system are known to exist in hippocampal mossy fibers, cerebellar parallel fibers and striatal projection fibers. Previously, we and others reported diffuse distribution of Nav1.2, a voltage-gated sodium channel α-subunit encoded by the SCN2A gene, on unmyelinated striatal projection fibers. Mutations in the SCN2A gene are associated with epilepsies and autism. In this study, we investigated the distribution of Nav1.2 on the unmyelinated fibers in the corpus callosum and stria terminalis by immunohistochemistry and immunoelectron microscopy analysis, suggesting that diffuse localization of Nav1.2 on mid-axonal regions can be a useful marker for unmyelinated fibers.
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Affiliation(s)
- Risa Yamano
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, 1-3 Miyakodanitatara, Kyotanabe-shi, Kyoto, 610-0394, Japan
| | - Haruko Miyazaki
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, 1-3 Miyakodanitatara, Kyotanabe-shi, Kyoto, 610-0394, Japan.
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, 1-3 Miyakodanitatara, Kyotanabe-shi, Kyoto, 610-0394, Japan.
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28
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Wang HG, Bavley CC, Li A, Jones RM, Hackett J, Bayleyen Y, Lee FS, Rajadhyaksha AM, Pitt GS. Scn2a severe hypomorphic mutation decreases excitatory synaptic input and causes autism-associated behaviors. JCI Insight 2021; 6:150698. [PMID: 34156984 PMCID: PMC8410058 DOI: 10.1172/jci.insight.150698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/17/2021] [Indexed: 12/02/2022] Open
Abstract
SCN2A, encoding the neuronal voltage-gated Na+ channel NaV1.2, is one of the most commonly affected loci linked to autism spectrum disorders (ASDs). Most ASD-associated mutations in SCN2A are loss-of-function mutations, but studies examining how such mutations affect neuronal function and whether Scn2a mutant mice display ASD endophenotypes have been inconsistent. We generated a protein truncation variant Scn2a mouse model (Scn2aΔ1898/+) by CRISPR that eliminates the NaV1.2 channel's distal intracellular C-terminal domain, and we analyzed the molecular and cellular consequences of this variant in a heterologous expression system, in neuronal culture, in brain slices, and in vivo. We also analyzed multiple behaviors in WT and Scn2aΔ1898/+ mice and correlated behaviors with clinical data obtained in human subjects with SCN2A variants. Expression of the NaV1.2 mutant in a heterologous expression system revealed decreased NaV1.2 channel function, and cultured pyramidal neurons isolated from Scn2aΔ1898/+ forebrain showed correspondingly reduced voltage-gated Na+ channel currents without compensation from other CNS voltage-gated Na+ channels. Na+ currents in inhibitory neurons were unaffected. Consistent with loss of voltage-gated Na+ channel currents, Scn2aΔ1898/+ pyramidal neurons displayed reduced excitability in forebrain neuronal culture and reduced excitatory synaptic input onto the pyramidal neurons in brain slices. Scn2aΔ1898/+ mice displayed several behavioral abnormalities, including abnormal social interactions that reflect behavior observed in humans with ASD and with harboring loss-of-function SCN2A variants. This model and its cellular electrophysiological characterizations provide a framework for tracing how a SCN2A loss-of-function variant leads to cellular defects that result in ASD-associated behaviors.
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Affiliation(s)
| | - Charlotte C. Bavley
- Feil Family Brain and Mind Research Institute, and
- Pediatric Neurology, Department of Pediatrics, Weill Cornell Medicine, New York, New York, USA
| | - Anfei Li
- Feil Family Brain and Mind Research Institute, and
| | - Rebecca M. Jones
- Weill Cornell Medicine, Center for Autism and the Developing Brain, White Plains, New York, USA
- Weill Cornell Autism Research Program and
- Sackler Institute for Developmental Psychobiology, Department of Psychiatry, Weill Cornell Medicine, New York, New York, USA
| | - Jonathan Hackett
- Pediatric Neurology, Department of Pediatrics, Weill Cornell Medicine, New York, New York, USA
| | | | - Francis S. Lee
- Feil Family Brain and Mind Research Institute, and
- Weill Cornell Autism Research Program and
- Sackler Institute for Developmental Psychobiology, Department of Psychiatry, Weill Cornell Medicine, New York, New York, USA
| | - Anjali M. Rajadhyaksha
- Feil Family Brain and Mind Research Institute, and
- Pediatric Neurology, Department of Pediatrics, Weill Cornell Medicine, New York, New York, USA
- Weill Cornell Autism Research Program and
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute
- Weill Cornell Autism Research Program and
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29
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Spratt PWE, Alexander RPD, Ben-Shalom R, Sahagun A, Kyoung H, Keeshen CM, Sanders SJ, Bender KJ. Paradoxical hyperexcitability from Na V1.2 sodium channel loss in neocortical pyramidal cells. Cell Rep 2021; 36:109483. [PMID: 34348157 PMCID: PMC8719649 DOI: 10.1016/j.celrep.2021.109483] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/17/2021] [Accepted: 07/13/2021] [Indexed: 12/17/2022] Open
Abstract
Loss-of-function variants in the gene SCN2A, which encodes the sodium channel NaV1.2, are strongly associated with autism spectrum disorder and intellectual disability. An estimated 20%-30% of children with these variants also suffer from epilepsy, with altered neuronal activity originating in neocortex, a region where NaV1.2 channels are expressed predominantly in excitatory pyramidal cells. This is paradoxical, as sodium channel loss in excitatory cells would be expected to dampen neocortical activity rather than promote seizure. Here, we examined pyramidal neurons lacking NaV1.2 channels and found that they were intrinsically hyperexcitable, firing high-frequency bursts of action potentials (APs) despite decrements in AP size and speed. Compartmental modeling and dynamic-clamp recordings revealed that NaV1.2 loss prevented potassium channels from properly repolarizing neurons between APs, increasing overall excitability by allowing neurons to reach threshold for subsequent APs more rapidly. This cell-intrinsic mechanism may, therefore, account for why SCN2A loss-of-function can paradoxically promote seizure.
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Affiliation(s)
- Perry W E Spratt
- Neuroscience Graduate Program, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Ryan P D Alexander
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Roy Ben-Shalom
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Atehsa Sahagun
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Henry Kyoung
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Caroline M Keeshen
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Stephan J Sanders
- Department of Psychiatry, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Kevin J Bender
- Neuroscience Graduate Program, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.
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30
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Zhang J, Chen X, Eaton M, Wu J, Ma Z, Lai S, Park A, Ahmad TS, Que Z, Lee JH, Xiao T, Li Y, Wang Y, Olivero-Acosta MI, Schaber JA, Jayant K, Yuan C, Huang Z, Lanman NA, Skarnes WC, Yang Y. Severe deficiency of the voltage-gated sodium channel Na V1.2 elevates neuronal excitability in adult mice. Cell Rep 2021; 36:109495. [PMID: 34348148 PMCID: PMC8382316 DOI: 10.1016/j.celrep.2021.109495] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/30/2021] [Accepted: 07/14/2021] [Indexed: 12/13/2022] Open
Abstract
Scn2a encodes the voltage-gated sodium channel NaV1.2, a main mediator of neuronal action potential firing. The current paradigm suggests that NaV1.2 gain-of-function variants enhance neuronal excitability, resulting in epilepsy, whereas NaV1.2 deficiency impairs neuronal excitability, contributing to autism. However, this paradigm does not explain why ∼20%-30% of individuals with NaV1.2 deficiency still develop seizures. Here, we report the counterintuitive finding that severe NaV1.2 deficiency results in increased neuronal excitability. Using a NaV1.2-deficient mouse model, we show enhanced intrinsic excitability of principal neurons in the prefrontal cortex and striatum, brain regions known to be involved in Scn2a-related seizures. This increased excitability is autonomous and reversible by genetic restoration of Scn2a expression in adult mice. RNA sequencing reveals downregulation of multiple potassium channels, including KV1.1. Correspondingly, KV channel openers alleviate the hyperexcitability of NaV1.2-deficient neurons. This unexpected neuronal hyperexcitability may serve as a cellular basis underlying NaV1.2 deficiency-related seizures.
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Affiliation(s)
- Jingliang Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Xiaoling Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Muriel Eaton
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Jiaxiang Wu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Zhixiong Ma
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Shirong Lai
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Anthony Park
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Talha S Ahmad
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Zhefu Que
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Ji Hea Lee
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Tiange Xiao
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Yuansong Li
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Yujia Wang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Maria I Olivero-Acosta
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - James A Schaber
- Bioscience Imaging Facility, Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
| | - Krishna Jayant
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Zhuo Huang
- Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Nadia A Lanman
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - William C Skarnes
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA.
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31
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Khoshkhoo S, Lal D, Walsh CA. Application of single cell genomics to focal epilepsies: A call to action. Brain Pathol 2021; 31:e12958. [PMID: 34196990 PMCID: PMC8412079 DOI: 10.1111/bpa.12958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/24/2022] Open
Abstract
Focal epilepsies are the largest epilepsy subtype and associated with significant morbidity. Somatic variation is a newly recognized genetic mechanism underlying a subset of focal epilepsies, but little is known about the processes through which somatic mosaicism causes seizures, the cell types carrying the pathogenic variants, or their developmental origin. Meanwhile, the inception of single cell biology has completely revolutionized the study of neurological diseases and has the potential to answer some of these key questions. Focusing on single cell genomics, transcriptomics, and epigenomics in focal epilepsy research, circumvents the averaging artifact associated with studying bulk brain tissue and offers the kind of granularity that is needed for investigating the consequences of somatic mosaicism. Here we have provided a brief overview of some of the most developed single cell techniques and the major considerations around applying them to focal epilepsy research.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Dennis Lal
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.,Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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32
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The role of GABAergic signalling in neurodevelopmental disorders. Nat Rev Neurosci 2021; 22:290-307. [PMID: 33772226 PMCID: PMC9001156 DOI: 10.1038/s41583-021-00443-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 02/08/2023]
Abstract
GABAergic inhibition shapes the connectivity, activity and plasticity of the brain. A series of exciting new discoveries provides compelling evidence that disruptions in a number of key facets of GABAergic inhibition have critical roles in the aetiology of neurodevelopmental disorders (NDDs). These facets include the generation, migration and survival of GABAergic neurons, the formation of GABAergic synapses and circuit connectivity, and the dynamic regulation of the efficacy of GABAergic signalling through neuronal chloride transporters. In this Review, we discuss recent work that elucidates the functions and dysfunctions of GABAergic signalling in health and disease, that uncovers the contribution of GABAergic neural circuit dysfunction to NDD aetiology and that leverages such mechanistic insights to advance precision medicine for the treatment of NDDs.
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33
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Interneuron Dysfunction in a New Mouse Model of SCN1A GEFS. eNeuro 2021; 8:ENEURO.0394-20.2021. [PMID: 33658306 PMCID: PMC8174035 DOI: 10.1523/eneuro.0394-20.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/15/2021] [Accepted: 02/19/2021] [Indexed: 11/21/2022] Open
Abstract
Advances in genome sequencing have identified over 1300 mutations in the SCN1A sodium channel gene that result in genetic epilepsies. However, it still remains unclear how most individual mutations within SCN1A result in seizures. A previous study has shown that the K1270T (KT) mutation, linked to genetic epilepsy with febrile seizure plus (GEFS+) in humans, causes heat-induced seizure activity associated with a temperature-dependent decrease in GABAergic neuron excitability in a Drosophila knock-in model. To examine the behavioral and cellular effects of this mutation in mammals, we introduced the equivalent KT mutation into the mouse (Mus musculus) Scn1a (Scn1aKT) gene using CRISPR/Cas9 and generated mutant lines in two widely used genetic backgrounds: C57BL/6NJ and 129X1/SvJ. In both backgrounds, mice homozygous for the KT mutation had spontaneous seizures and died by postnatal day (P)23. There was no difference in mortality of heterozygous KT mice compared with wild-type littermates up to six months old. Heterozygous mutants exhibited heat-induced seizures at ∼42°C, a temperature that did not induce seizures in wild-type littermates. In acute hippocampal slices at permissive temperatures, current-clamp recordings revealed a significantly depolarized shift in action potential threshold and reduced action potential amplitude in parvalbumin (PV)-expressing inhibitory CA1 interneurons in Scn1aKT/+ mice. There was no change in the firing properties of excitatory CA1 pyramidal neurons. These results suggest that a constitutive decrease in inhibitory interneuron excitability contributes to the seizure phenotype in the mouse model.
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34
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Eaton M, Zhang J, Ma Z, Park AC, Lietzke E, Romero CM, Liu Y, Coleman ER, Chen X, Xiao T, Que Z, Lai S, Wu J, Lee JH, Palant S, Nguyen HP, Huang Z, Skarnes WC, Koss WA, Yang Y. Generation and basic characterization of a gene-trap knockout mouse model of Scn2a with a substantial reduction of voltage-gated sodium channel Na v 1.2 expression. GENES, BRAIN, AND BEHAVIOR 2021; 20:e12725. [PMID: 33369088 DOI: 10.1111/gbb.12725] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022]
Abstract
Large-scale genetic studies revealed SCN2A as one of the most frequently mutated genes in patients with neurodevelopmental disorders. SCN2A encodes for the voltage-gated sodium channel isoform 1.2 (Nav 1.2) expressed in the neurons of the central nervous system. Homozygous knockout (null) of Scn2a in mice is perinatal lethal, whereas heterozygous knockout of Scn2a (Scn2a+/- ) results in mild behavior abnormalities. The Nav 1.2 expression level in Scn2a+/- mice is reported to be around 50-60% of the wild-type (WT) level, which indicates that a close to 50% reduction of Nav 1.2 expression may not be sufficient to lead to major behavioral phenotypes in mice. To overcome this barrier, we characterized a novel mouse model of severe Scn2a deficiency using a targeted gene-trap knockout (gtKO) strategy. This approach produces viable homozygous mice (Scn2agtKO/gtKO ) that can survive to adulthood, with about a quarter of Nav 1.2 expression compared to WT mice. Innate behaviors like nesting and mating were profoundly disrupted in Scn2agtKO/gtKO mice. Notably, Scn2agtKO/gtKO mice have a significantly decreased center duration compared to WT in the open field test, suggesting anxiety-like behaviors in a novel, open space. These mice also have decreased thermal and cold tolerance. Additionally, Scn2agtKO/gtKO mice have increased fix-pattern exploration in the novel object exploration test and a slight increase in grooming, indicating a detectable level of repetitive behaviors. They bury little to no marbles and have decreased interaction with novel objects. These Scn2a gene-trap knockout mice thus provide a unique model to study pathophysiology associated with severe Scn2a deficiency.
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Affiliation(s)
- Muriel Eaton
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Jingliang Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Zhixiong Ma
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Anthony C Park
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Emma Lietzke
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Chloé M Romero
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Yushuang Liu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Emily R Coleman
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Xiaoling Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Tiange Xiao
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Zhefu Que
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Shirong Lai
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Jiaxiang Wu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Ji Hea Lee
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Sophia Palant
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Huynhvi P Nguyen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - Zhuo Huang
- Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - William C Skarnes
- Department of Cellular Engineering, The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Wendy A Koss
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
- Office of the Executive Vice President for Research and Partnerships, Purdue University, West Lafayette, Indiana, USA
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
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35
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Mantegazza M, Cestèle S, Catterall WA. Sodium channelopathies of skeletal muscle and brain. Physiol Rev 2021; 101:1633-1689. [PMID: 33769100 DOI: 10.1152/physrev.00025.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.
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Affiliation(s)
- Massimo Mantegazza
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France.,INSERM, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France
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Abstract
The voltage-gated sodium channel α-subunit genes comprise a highly conserved gene family. Mutations of three of these genes, SCN1A, SCN2A and SCN8A, are responsible for a significant burden of neurological disease. Recent progress in identification and functional characterization of patient variants is generating new insights and novel approaches to therapy for these devastating disorders. Here we review the basic elements of sodium channel function that are used to characterize patient variants. We summarize a large body of work using global and conditional mouse mutants to characterize the in vivo roles of these channels. We provide an overview of the neurological disorders associated with mutations of the human genes and examples of the effects of patient mutations on channel function. Finally, we highlight therapeutic interventions that are emerging from new insights into mechanisms of sodium channelopathies.
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Altered hippocampal gene expression, glial cell population, and neuronal excitability in aminopeptidase P1 deficiency. Sci Rep 2021; 11:932. [PMID: 33441619 PMCID: PMC7806765 DOI: 10.1038/s41598-020-79656-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/04/2020] [Indexed: 01/09/2023] Open
Abstract
Inborn errors of metabolism are often associated with neurodevelopmental disorders and brain injury. A deficiency of aminopeptidase P1, a proline-specific endopeptidase encoded by the Xpnpep1 gene, causes neurological complications in both humans and mice. In addition, aminopeptidase P1-deficient mice exhibit hippocampal neurodegeneration and impaired hippocampus-dependent learning and memory. However, the molecular and cellular changes associated with hippocampal pathology in aminopeptidase P1 deficiency are unclear. We show here that a deficiency of aminopeptidase P1 modifies the glial population and neuronal excitability in the hippocampus. Microarray and real-time quantitative reverse transcription-polymerase chain reaction analyses identified 14 differentially expressed genes (Casp1, Ccnd1, Myoc, Opalin, Aldh1a2, Aspa, Spp1, Gstm6, Serpinb1a, Pdlim1, Dsp, Tnfaip6, Slc6a20a, Slc22a2) in the Xpnpep1−/− hippocampus. In the hippocampus, aminopeptidase P1-expression signals were mainly detected in neurons. However, deficiency of aminopeptidase P1 resulted in fewer hippocampal astrocytes and increased density of microglia in the hippocampal CA3 area. In addition, Xpnpep1−/− CA3b pyramidal neurons were more excitable than wild-type neurons. These results indicate that insufficient astrocytic neuroprotection and enhanced neuronal excitability may underlie neurodegeneration and hippocampal dysfunction in aminopeptidase P1 deficiency.
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Wang W, Frankel WN. Overlaps, gaps, and complexities of mouse models of Developmental and Epileptic Encephalopathy. Neurobiol Dis 2021; 148:105220. [PMID: 33301879 PMCID: PMC8547712 DOI: 10.1016/j.nbd.2020.105220] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/17/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022] Open
Abstract
Mouse models have made innumerable contributions to understanding the genetic basis of neurological disease and pathogenic mechanisms and to therapy development. Here we consider the current state of mouse genetic models of Developmental and Epileptic Encephalopathy (DEE), representing a set of rare but devastating and largely intractable childhood epilepsies. By examining the range of mouse lines available in this rapidly moving field and by detailing both expected and unusual features in representative examples, we highlight lessons learned in an effort to maximize the full potential of this powerful resource for preclinical studies.
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Affiliation(s)
- Wanqi Wang
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States of America.
| | - Wayne N Frankel
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States of America.
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39
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Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
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Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
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Hayase Y, Amano S, Hashizume K, Tominaga T, Miyamoto H, Kanno Y, Ueno-Inoue Y, Inoue T, Yamada M, Ogata S, Balan S, Hayashi K, Miura Y, Tokudome K, Ohno Y, Nishijo T, Momiyama T, Yanagawa Y, Takizawa A, Mashimo T, Serikawa T, Sekine A, Nakagawa E, Takeshita E, Yoshikawa T, Waga C, Inoue K, Goto YI, Nabeshima Y, Ihara N, Yamakawa K, Taya S, Hoshino M. Down syndrome cell adhesion molecule like-1 (DSCAML1) links the GABA system and seizure susceptibility. Acta Neuropathol Commun 2020; 8:206. [PMID: 33256836 PMCID: PMC7706048 DOI: 10.1186/s40478-020-01082-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 11/15/2020] [Indexed: 12/18/2022] Open
Abstract
The Ihara epileptic rat (IER) is a mutant model with limbic-like seizures whose pathology and causative gene remain elusive. In this report, via linkage analysis, we identified Down syndrome cell adhesion molecule-like 1(Dscaml1) as the responsible gene for IER. A single base mutation in Dscaml1 causes abnormal splicing, leading to lack of DSCAML1. IERs have enhanced seizure susceptibility and accelerated kindling establishment. Furthermore, GABAergic neurons are severely reduced in the entorhinal cortex (ECx) of these animals. Voltage-sensitive dye imaging that directly presents the excitation status of brain slices revealed abnormally persistent excitability in IER ECx. This suggests that reduced GABAergic neurons may cause weak sustained entorhinal cortex activations, leading to natural kindling via the perforant path that could cause dentate gyrus hypertrophy and epileptogenesis. Furthermore, we identified a single nucleotide substitution in a human epilepsy that would result in one amino acid change in DSCAML1 (A2105T mutation). The mutant DSCAML1A2105T protein is not presented on the cell surface, losing its homophilic cell adhesion ability. We generated knock-in mice (Dscaml1A2105T) carrying the corresponding mutation and observed reduced GABAergic neurons in the ECx as well as spike-and-wave electrocorticogram. We conclude that DSCAML1 is required for GABAergic neuron placement in the ECx and suppression of seizure susceptibility in rodents. Our findings suggest that mutations in DSCAML1 may affect seizure susceptibility in humans.
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Affiliation(s)
- Yoneko Hayase
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Shigeru Amano
- Graduate School of Medicine Faculty of Health Science, Department of Laboratory Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Koichi Hashizume
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Takashi Tominaga
- Laboratory for Neural Circuit System, Institute of Neuroscience, Tokushima Bunri University, Sanuki, 769-2300, Japan
| | - Hiroyuki Miyamoto
- International Research Center for Neurointelligence (IRCN), The University of Tokyo, Tokyo, 187-8502, Japan
| | - Yukie Kanno
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Yukiko Ueno-Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Mayumi Yamada
- Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Shigehiro Ogata
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Shabeesh Balan
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Ken Hayashi
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Yoshiki Miura
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kentaro Tokudome
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, 569-1094, Japan
| | - Yukihiro Ohno
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, 569-1094, Japan
| | - Takuma Nishijo
- Department of Pharmacology, Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Toshihiko Momiyama
- Department of Pharmacology, Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Yuchio Yanagawa
- Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Akiko Takizawa
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Tomoji Mashimo
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
- Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, 108-839, Japan
| | - Tadao Serikawa
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Akihiro Sekine
- Omics-Based Medicine, Center for Preventive Medical Science, Chiba University, Chiba, 260-0856, Japan
| | - Eiji Nakagawa
- Department of Pediatric Neurology, National Center Hospital, NCNP, Tokyo, 187-8551, Japan
| | - Eri Takeshita
- Department of Pediatric Neurology, National Center Hospital, NCNP, Tokyo, 187-8551, Japan
| | - Takeo Yoshikawa
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Chikako Waga
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Yoichi Nabeshima
- Foundation for Biomedical Research and Innovation, Kobe, 650-0047, Japan
| | - Nobuo Ihara
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kazuhiro Yamakawa
- Graduate School of Medical Science, Nagoya City University, Nagoya, 467-8601, Japan
| | - Shinichiro Taya
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
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41
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Rai D, Akagi T, Shimohata A, Ishii T, Gangi M, Maruyama T, Wada-Kiyama Y, Ogiwara I, Kaneda M. Involvement of the C-terminal domain in cell surface localization and G-protein coupling of mGluR6. J Neurochem 2020; 158:837-848. [PMID: 33067823 DOI: 10.1111/jnc.15217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 05/25/2020] [Accepted: 10/11/2020] [Indexed: 01/05/2023]
Abstract
Metabotropic glutamate receptor 6, mGluR6, interacts with scaffold proteins and Gβγ subunits via its intracellular C-terminal domain (CTD). The mGluR6 pathway is critically involved in the retinal processing of visual signals. We herein investigated whether the CTD (residues 840-871) was necessary for mGluR6 cell surface localization and G-protein coupling using mGluR6-CTD mutants with immunocytochemistry, surface biotinylation assays, and electrophysiological approaches. We used 293T cells and primary hippocampal neurons as model systems. We examined C-terminally truncated mGluR6 and showed that the removal of up to residue 858 did not affect surface localization or glutamate-induced G-protein-mediated responses, whereas a 15-amino acid deletion (Δ857-871) impaired these functions. However, a 21-amino acid deletion (Δ851-871) restored surface localization and glutamate-dependent responses, which were again attenuated when the entire CTD was removed. The sequence alignment of group III mGluRs showed conserved amino acids resembling an ER retention motif in the CTD. These results suggest that the intracellular CTD is required for the cell surface transportation and receptor function of mGluR6, whereas it may contain regulatory elements for intracellular trafficking and signaling.
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Affiliation(s)
- Dilip Rai
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Takumi Akagi
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | | | - Toshiyuki Ishii
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Mie Gangi
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Takuma Maruyama
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | | | - Ikuo Ogiwara
- Department of Physiology, Nippon Medical School, Tokyo, Japan
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42
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Liu Y, Tang Y, Yan J, Du D, Yang Y, Chen F. Deletion of Kv10.2 Causes Abnormal Dendritic Arborization and Epilepsy Susceptibility. Neurochem Res 2020; 45:2949-2958. [PMID: 33033860 DOI: 10.1007/s11064-020-03143-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/27/2022]
Abstract
The abnormal function of the voltage-gated potassium channel Kv10.2 can induce epilepsy. However, the physiological function of Kv10.2 in the central nervous system remains unclear. In this study, we found that Kv10.2 knockout (KO) increased the complexity of neurons in the CA3 subarea of hippocampus. Kv10.2 KO led to enlarged somata, elongated dendritic length, and increased the number of dendritic tips in cultured rat hippocampus neurons. Kv10.2 KO also increased Synapsin I and PSD95 protein density in cultured rat hippocampal neurons. Whole cell patch-clamp recordings of brain slices in the CA3 subarea of hippocampus revealed that Kv10.2 KO increased the amplitude of spontaneous excitatory postsynaptic currents (sEPSC) and miniature excitatory postsynaptic currents (mEPSC), depolarized the resting membrane potential and increased the action potential firing, reduced the rheobase and increased the input resistance, which results in enhanced neuronal excitability. Furthermore, we made electroencephalogram (EEG) recordings of brain activity in freely moving rats before and after inducing seizures by pentylenetetrazole (PTZ) injection. Kv10.2 KO rats dramatically increased the EEG amplitude during epilepsy. Behavioral observation after seizure induction revealed that Kv10.2 KO rats demonstrated shortened onset latency, prolonged duration, and increased seizure severity when compared with wild type rats. Therefore, this study provides a new link between Kv10.2 and neuronal morphology and higher intrinsic excitability.
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Affiliation(s)
- Yamei Liu
- School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Yunfei Tang
- School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Jinyu Yan
- School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Dongshu Du
- School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, 47907, USA
| | - Fuxue Chen
- School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China.
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43
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Neurobiological Mechanisms of Autism Spectrum Disorder and Epilepsy, Insights from Animal Models. Neuroscience 2020; 445:69-82. [DOI: 10.1016/j.neuroscience.2020.02.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/22/2020] [Accepted: 02/21/2020] [Indexed: 02/09/2023]
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44
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Turner TJ, Zourray C, Schorge S, Lignani G. Recent advances in gene therapy for neurodevelopmental disorders with epilepsy. J Neurochem 2020; 157:229-262. [PMID: 32880951 PMCID: PMC8436749 DOI: 10.1111/jnc.15168] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022]
Abstract
Neurodevelopmental disorders can be caused by mutations in neuronal genes fundamental to brain development. These disorders have severe symptoms ranging from intellectually disability, social and cognitive impairments, and a subset are strongly linked with epilepsy. In this review, we focus on those neurodevelopmental disorders that are frequently characterized by the presence of epilepsy (NDD + E). We loosely group the genes linked to NDD + E with different neuronal functions: transcriptional regulation, intrinsic excitability and synaptic transmission. All these genes have in common a pivotal role in defining the brain architecture and function during early development, and when their function is altered, symptoms can present in the first stages of human life. The relationship with epilepsy is complex. In some NDD + E, epilepsy is a comorbidity and in others seizures appear to be the main cause of the pathology, suggesting that either structural changes (NDD) or neuronal communication (E) can lead to these disorders. Furthermore, grouping the genes that cause NDD + E, we review the uses and limitations of current models of the different disorders, and how different gene therapy strategies are being developed to treat them. We highlight where gene replacement may not be a treatment option, and where innovative therapeutic tools, such as CRISPR‐based gene editing, and new avenues of delivery are required. In general this group of genetically defined disorders, supported increasing knowledge of the mechanisms leading to neurological dysfunction serve as an excellent collection for illustrating the translational potential of gene therapy, including newly emerging tools.
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Affiliation(s)
- Thomas J Turner
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Clara Zourray
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Department of Pharmacology, UCL School of Pharmacy, London, UK
| | | | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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45
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D'Adamo MC, Liantonio A, Conte E, Pessia M, Imbrici P. Ion Channels Involvement in Neurodevelopmental Disorders. Neuroscience 2020; 440:337-359. [PMID: 32473276 DOI: 10.1016/j.neuroscience.2020.05.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/14/2022]
Abstract
Inherited and sporadic mutations in genes encoding for brain ion channels, affecting membrane expression or biophysical properties, have been associated with neurodevelopmental disorders characterized by epilepsy, cognitive and behavioral deficits with significant phenotypic and genetic heterogeneity. Over the years, the screening of a growing number of patients and the functional characterization of newly identified mutations in ion channels genes allowed to recognize new phenotypes and to widen the clinical spectrum of known diseases. Furthermore, advancements in understanding disease pathogenesis at atomic level or using patient-derived iPSCs and animal models have been pivotal to orient therapeutic intervention and to put the basis for the development of novel pharmacological options for drug-resistant disorders. In this review we will discuss major improvements and critical issues concerning neurodevelopmental disorders caused by dysfunctions in brain sodium, potassium, calcium, chloride and ligand-gated ion channels.
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Affiliation(s)
- Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | | | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta; Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy.
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Pathophysiological roles and therapeutic potential of voltage-gated ion channels (VGICs) in pain associated with herpesvirus infection. Cell Biosci 2020; 10:70. [PMID: 32489585 PMCID: PMC7247163 DOI: 10.1186/s13578-020-00430-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023] Open
Abstract
Herpesvirus is ranked as one of the grand old members of all pathogens. Of all the viruses in the superfamily, Herpes simplex virus type 1 (HSV-1) is considered as a model virus for a variety of reasons. In a permissive non-neuronal cell culture, HSV-1 concludes the entire life cycle in approximately 18–20 h, encoding approximately 90 unique transcriptional units. In latency, the robust viral gene expression is suppressed in neurons by a group of noncoding RNA. Historically the lesions caused by the virus can date back to centuries ago. As a neurotropic pathogen, HSV-1 is associated with painful oral lesions, severe keratitis and lethal encephalitis. Transmission of pain signals is dependent on the generation and propagation of action potential in sensory neurons. T-type Ca2+ channels serve as a preamplifier of action potential generation. Voltage-gated Na+ channels are the main components for action potential production. This review summarizes not only the voltage-gated ion channels in neuropathic disorders but also provides the new insights into HSV-1 induced pain.
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47
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Hedrich UBS, Lauxmann S, Lerche H. SCN2A channelopathies: Mechanisms and models. Epilepsia 2020; 60 Suppl 3:S68-S76. [PMID: 31904120 DOI: 10.1111/epi.14731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/21/2019] [Indexed: 01/01/2023]
Abstract
Variants in the SCN2A gene, encoding the voltage-gated sodium channel NaV 1.2, cause a variety of neuropsychiatric syndromes with different severity ranging from self-limiting epilepsies with early onset to developmental and epileptic encephalopathy with early or late onset and intellectual disability (ID), as well as ID or autism without seizures. Functional analysis of channel defects demonstrated a genotype-phenotype correlation and suggested effective treatment options for one group of affected patients carrying gain-of-function variants. Here, we sum up the functional mechanisms underlying different phenotypes of patients with SCN2A channelopathies and present currently available models that can help in understanding SCN2A-related disorders.
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Affiliation(s)
- Ulrike B S Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
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48
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Denomme N, Lukowski AL, Hull JM, Jameson MB, Bouza AA, Narayan ARH, Isom LL. The voltage-gated sodium channel inhibitor, 4,9-anhydrotetrodotoxin, blocks human Na v1.1 in addition to Na v1.6. Neurosci Lett 2020; 724:134853. [PMID: 32114117 PMCID: PMC7096269 DOI: 10.1016/j.neulet.2020.134853] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 11/23/2022]
Abstract
Voltage-gated sodium channels (VGSCs) are responsible for the initiation and propagation of action potentials in neurons. The human genome includes ten human VGSC α-subunit genes, SCN(X)A, encoding Nav1.1-1.9 plus Nax. To understand the unique role that each VGSC plays in normal and pathophysiological function in neural networks, compounds with high affinity and selectivity for specific VGSC subtypes are required. Toward that goal, a structural analog of the VGSC pore blocker tetrodotoxin, 4,9-anhydrotetrodotoxin (4,9-ah-TTX), has been reported to be more selective in blocking Na+ current mediated by Nav1.6 than other TTX-sensitive VGSCs, including Nav1.2, Nav1.3, Nav1.4, and Nav1.7. While SCN1A, encoding Nav1.1, has been implicated in several neurological diseases, the effects of 4,9-ah-TTX on Nav1.1-mediated Na+ current have not been tested. Here, we compared the binding of 4,9-ah-TTX for human and mouse brain preparations, and the effects of 4,9-ah-TTX on human Nav1.1-, Nav1.3- and Nav1.6-mediated Na+ currents using the whole-cell patch clamp technique in heterologous cells. We show that, while 4,9-ah-TTX administration results in significant blockade of Nav1.6-mediated Na+ current in the nanomolar range, it also has significant effects on Nav1.1-mediated Na+ current. Thus, 4,9-ah-TTX is not a useful tool in identifying Nav1.6-specific effects in human brain networks.
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Affiliation(s)
- Nicholas Denomme
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan, 48109 United States
| | - April L Lukowski
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109 United States
| | - Jacob M Hull
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, 48109 United States
| | - Margaret B Jameson
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Molecular and Cellular Pharmacology Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 United States
| | - Alexandra A Bouza
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, 48109 United States
| | - Alison R H Narayan
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109 United States; Department of Chemistry, University of Michigan, Ann Arbor, Michigan, 48109 United States
| | - Lori L Isom
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, 48109 United States; Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, 48109 United States; Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109 United States.
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49
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Kruth KA, Grisolano TM, Ahern CA, Williams AJ. SCN2A channelopathies in the autism spectrum of neuropsychiatric disorders: a role for pluripotent stem cells? Mol Autism 2020; 11:23. [PMID: 32264956 PMCID: PMC7140374 DOI: 10.1186/s13229-020-00330-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
Efforts to identify the causes of autism spectrum disorders have highlighted the importance of both genetics and environment, but the lack of human models for many of these disorders limits researchers’ attempts to understand the mechanisms of disease and to develop new treatments. Induced pluripotent stem cells offer the opportunity to study specific genetic and environmental risk factors, but the heterogeneity of donor genetics may obscure important findings. Diseases associated with unusually high rates of autism, such as SCN2A syndromes, provide an opportunity to study specific mutations with high effect sizes in a human genetic context and may reveal biological insights applicable to more common forms of autism. Loss-of-function mutations in the SCN2A gene, which encodes the voltage-gated sodium channel NaV1.2, are associated with autism rates up to 50%. Here, we review the findings from experimental models of SCN2A syndromes, including mouse and human cell studies, highlighting the potential role for patient-derived induced pluripotent stem cell technology to identify the molecular and cellular substrates of autism.
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Affiliation(s)
- Karina A Kruth
- Department of Psychiatry, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2326 PBDB, Iowa City, IA, 52242, USA
| | - Tierney M Grisolano
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2312 PBDB, Iowa City, IA, 52242, USA
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2312 PBDB, Iowa City, IA, 52242, USA
| | - Aislinn J Williams
- Department of Psychiatry, Iowa Neuroscience Institute, University of Iowa, 169 Newton Rd, 2326 PBDB, Iowa City, IA, 52242, USA.
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50
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Chow CY, Chin YKY, Walker AA, Guo S, Blomster LV, Ward MJ, Herzig V, Rokyta DR, King GF. Venom Peptides with Dual Modulatory Activity on the Voltage-Gated Sodium Channel Na V1.1 Provide Novel Leads for Development of Antiepileptic Drugs. ACS Pharmacol Transl Sci 2019; 3:119-134. [PMID: 32259093 DOI: 10.1021/acsptsci.9b00079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Indexed: 01/14/2023]
Abstract
Voltage-gated sodium (NaV) channels play a fundamental role in normal neurological function, especially via the initiation and propagation of action potentials. The NaV1.1 subtype is found in inhibitory interneurons of the brain and it is essential for maintaining a balance between excitation and inhibition in neuronal networks. Heterozygous loss-of-function mutations of SCN1A, the gene encoding NaV1.1, underlie Dravet syndrome (DS), a severe pediatric epilepsy. We recently demonstrated that selective inhibition of NaV1.1 inactivation prevents seizures and premature death in a mouse model of DS. Thus, selective modulators of NaV1.1 might be useful therapeutics for treatment of DS as they target the underlying molecular deficit. Numerous scorpion-venom peptides have been shown to modulate the activity of NaV channels, but little is known about their activity at NaV1.1. Here we report the isolation, sequence, three-dimensional structure, recombinant production, and functional characterization of two peptidic modulators of NaV1.1 from venom of the buthid scorpion Hottentotta jayakari. These peptides, Hj1a and Hj2a, are potent agonists of NaV1.1 (EC50 of 17 and 32 nM, respectively), and they present dual α/β activity by modifying both the activation and inactivation properties of the channel. NMR studies of rHj1a indicate that it adopts a cystine-stabilized αβ fold similar to known scorpion toxins. Although Hj1a and Hj2a have only limited selectivity for NaV1.1, their unusual dual mode of action provides an alternative approach to the development of selective NaV1.1 modulators for the treatment of DS.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Yanni K-Y Chin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Shaodong Guo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Linda V Blomster
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Micaiah J Ward
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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