1
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Lopez L, De Waard S, Meudal H, Caumes C, Khakh K, Peigneur S, Oliveira-Mendes B, Lin S, De Waele J, Montnach J, Cestèle S, Tessier A, Johnson JP, Mantegazza M, Tytgat J, Cohen C, Béroud R, Bosmans F, Landon C, De Waard M. Structure-function relationship of new peptides activating human Na v1.1. Biomed Pharmacother 2023; 165:115173. [PMID: 37453200 DOI: 10.1016/j.biopha.2023.115173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Nav1.1 is an important pharmacological target as this voltage-gated sodium channel is involved in neurological and cardiac syndromes. Channel activators are actively sought to try to compensate for haploinsufficiency in several of these pathologies. Herein we used a natural source of new peptide compounds active on ion channels and screened for drugs capable to inhibit channel inactivation as a way to compensate for decreased channel function. We discovered that JzTx-34 is highly active on Nav1.1 and subsequently performed a full structure-activity relationship investigation to identify its pharmacophore. These experiments will help interpret the mechanism of action of this and formerly identified peptides as well as the future identification of new peptides. We also reveal structural determinants that make natural ICK peptides active against Nav1.1 challenging to synthesize. Altogether, the knowledge gained by this study will help facilitate the discovery and development of new compounds active on this critical ion channel target.
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Affiliation(s)
- Ludivine Lopez
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France
| | - Stephan De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France
| | - Hervé Meudal
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | | | - Kuldip Khakh
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | | | - Sophia Lin
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Jolien De Waele
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Jérôme Montnach
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - Sandrine Cestèle
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Agnès Tessier
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - J P Johnson
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Massimo Mantegazza
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Jan Tytgat
- University of Leuven, 3000 Leuven, Belgium
| | - Charles Cohen
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Céline Landon
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | - Michel De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France.
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2
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Goff KM, Liebergall SR, Jiang E, Somarowthu A, Goldberg EM. VIP interneuron impairment promotes in vivo circuit dysfunction and autism-related behaviors in Dravet syndrome. Cell Rep 2023; 42:112628. [PMID: 37310860 PMCID: PMC10592464 DOI: 10.1016/j.celrep.2023.112628] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 04/01/2023] [Accepted: 05/24/2023] [Indexed: 06/15/2023] Open
Abstract
Dravet syndrome (DS) is a severe neurodevelopmental disorder caused by loss-of-function variants in SCN1A, which encodes the voltage-gated sodium channel subunit Nav1.1. We recently showed that neocortical vasoactive intestinal peptide interneurons (VIP-INs) express Nav1.1 and are hypoexcitable in DS (Scn1a+/-) mice. Here, we investigate VIP-IN function at the circuit and behavioral level by performing in vivo 2-photon calcium imaging in awake wild-type (WT) and Scn1a+/- mice. VIP-IN and pyramidal neuron activation during behavioral transition from quiet wakefulness to active running is diminished in Scn1a+/- mice, and optogenetic activation of VIP-INs restores pyramidal neuron activity to WT levels during locomotion. VIP-IN selective Scn1a deletion reproduces core autism-spectrum-disorder-related behaviors in addition to cellular- and circuit-level deficits in VIP-IN function, but without epilepsy, sudden death, or avoidance behaviors seen in the global model. Hence, VIP-INs are impaired in vivo, which may underlie non-seizure cognitive and behavioral comorbidities in DS.
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Affiliation(s)
- Kevin M Goff
- Medical Scientist Training Program (MSTP), The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Neuroscience Graduate Group, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Sophie R Liebergall
- Medical Scientist Training Program (MSTP), The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Neuroscience Graduate Group, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Evan Jiang
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ala Somarowthu
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ethan M Goldberg
- Neuroscience Graduate Group, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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3
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Abstract
Recent advances in genomics have revealed a wide spectrum of genetic variants associated with neurodevelopmental disorders at an unprecedented scale. An increasing number of studies have consistently identified mutations-both inherited and de novo-impacting the function of specific brain circuits. This suggests that, during brain development, alterations in distinct neural circuits, cell types, or broad regulatory pathways ultimately shaping synapses might be a dysfunctional process underlying these disorders. Here, we review findings from human studies and animal model research to provide a comprehensive description of synaptic and circuit mechanisms implicated in neurodevelopmental disorders. We discuss how specific synaptic connections might be commonly disrupted in different disorders and the alterations in cognition and behaviors emerging from imbalances in neuronal circuits. Moreover, we review new approaches that have been shown to restore or mitigate dysfunctional processes during specific critical windows of brain development. Considering the heterogeneity of neurodevelopmental disorders, we also highlight the recent progress in developing improved clinical biomarkers and strategies that will help to identify novel therapeutic compounds and opportunities for early intervention.
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Affiliation(s)
- David Exposito-Alonso
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom;
- Current affiliation: Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
| | - Beatriz Rico
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom;
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4
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Fawcett JW, Fyhn M, Jendelova P, Kwok JCF, Ruzicka J, Sorg BA. The extracellular matrix and perineuronal nets in memory. Mol Psychiatry 2022; 27:3192-3203. [PMID: 35760878 PMCID: PMC9708575 DOI: 10.1038/s41380-022-01634-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/09/2022] [Accepted: 05/16/2022] [Indexed: 02/06/2023]
Abstract
All components of the CNS are surrounded by a diffuse extracellular matrix (ECM) containing chondroitin sulphate proteoglycans (CSPGs), heparan sulphate proteoglycans (HSPGs), hyaluronan, various glycoproteins including tenascins and thrombospondin, and many other molecules that are secreted into the ECM and bind to ECM components. In addition, some neurons, particularly inhibitory GABAergic parvalbumin-positive (PV) interneurons, are surrounded by a more condensed cartilage-like ECM called perineuronal nets (PNNs). PNNs surround the soma and proximal dendrites as net-like structures that surround the synapses. Attention has focused on the role of PNNs in the control of plasticity, but it is now clear that PNNs also play an important part in the modulation of memory. In this review we summarize the role of the ECM, particularly the PNNs, in the control of various types of memory and their participation in memory pathology. PNNs are now being considered as a target for the treatment of impaired memory. There are many potential treatment targets in PNNs, mainly through modulation of the sulphation, binding, and production of the various CSPGs that they contain or through digestion of their sulphated glycosaminoglycans.
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Affiliation(s)
- James W Fawcett
- John van Geest Centre for Brain Repair, Department Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK.
- Centre for Reconstructive Neuroscience, Institute for Experimental Medicine CAS, Videnska 1083, Prague 4, Prague, Czech Republic.
| | - Marianne Fyhn
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Pavla Jendelova
- Centre for Reconstructive Neuroscience, Institute for Experimental Medicine CAS, Videnska 1083, Prague 4, Prague, Czech Republic
| | - Jessica C F Kwok
- Centre for Reconstructive Neuroscience, Institute for Experimental Medicine CAS, Videnska 1083, Prague 4, Prague, Czech Republic
- School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Jiri Ruzicka
- Centre for Reconstructive Neuroscience, Institute for Experimental Medicine CAS, Videnska 1083, Prague 4, Prague, Czech Republic
| | - Barbara A Sorg
- Robert S. Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR, USA
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5
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Wong JC. On the Right Trk: Towards an Effective Treatment for Dravet Syndrome. Epilepsy Curr 2022; 22:387-389. [DOI: 10.1177/15357597221112794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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6
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Tanenhaus A, Stowe T, Young A, McLaughlin J, Aeran R, Lin IW, Li J, Hosur R, Chen M, Leedy J, Chou T, Pillay S, Vila MC, Kearney JA, Moorhead M, Belle A, Tagliatela S. Cell-Selective Adeno-Associated Virus-Mediated SCN1A Gene Regulation Therapy Rescues Mortality and Seizure Phenotypes in a Dravet Syndrome Mouse Model and Is Well Tolerated in Nonhuman Primates. Hum Gene Ther 2022; 33:579-597. [PMID: 35435735 PMCID: PMC9242722 DOI: 10.1089/hum.2022.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Dravet syndrome (DS) is a developmental and epileptic encephalopathy caused by monoallelic loss-of-function variants in the SCN1A gene. SCN1A encodes for the alpha subunit of the voltage-gated type I sodium channel (NaV1.1), the primary voltage-gated sodium channel responsible for generation of action potentials in GABAergic inhibitory interneurons. In these studies, we tested the efficacy of an adeno-associated virus serotype 9 (AAV9) SCN1A gene regulation therapy, AAV9-REGABA-eTFSCN1A, designed to target transgene expression to GABAergic inhibitory neurons and reduce off-target expression within excitatory cells, in the Scn1a+/- mouse model of DS. Biodistribution and preliminary safety were evaluated in nonhuman primates (NHPs). AAV9-REGABA-eTFSCN1A was engineered to upregulate SCN1A expression levels within GABAergic inhibitory interneurons to correct the underlying haploinsufficiency and circuit dysfunction. A single bilateral intracerebroventricular (ICV) injection of AAV9-REGABA-eTFSCN1A in Scn1a+/- postnatal day 1 mice led to increased SCN1A mRNA transcripts, specifically within GABAergic inhibitory interneurons, and NaV1.1 protein levels in the brain. This was associated with a significant decrease in the occurrence of spontaneous and hyperthermia-induced seizures, and prolonged survival for over a year. In NHPs, delivery of AAV9-REGABA-eTFSCN1A by unilateral ICV injection led to widespread vector biodistribution and transgene expression throughout the brain, including key structures involved in epilepsy and cognitive behaviors, such as hippocampus and cortex. AAV9-REGABA-eTFSCN1A was well tolerated, with no adverse events during administration, no detectable changes in clinical observations, no adverse findings in histopathology, and no dorsal root ganglion-related toxicity. Our results support the clinical development of AAV9-REGABA-eTFSCN1A (ETX101) as an effective and targeted disease-modifying approach to SCN1A+ DS.
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Affiliation(s)
- Annie Tanenhaus
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Timothy Stowe
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Andrew Young
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - John McLaughlin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Rangoli Aeran
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - I. Winnie Lin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jianmin Li
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Ming Chen
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jennifer Leedy
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Tiffany Chou
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Sirika Pillay
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Jennifer A. Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Martin Moorhead
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Archana Belle
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Stephanie Tagliatela
- Encoded Therapeutics, Inc., South San Francisco, California, USA.,Correspondence: Stephanie Tagliatela, Encoded Therapeutics, Inc., 341 Oyster Point Boulevard, South San Francisco, CA 94080, USA.
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7
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Almog Y, Mavashov A, Brusel M, Rubinstein M. Functional Investigation of a Neuronal Microcircuit in the CA1 Area of the Hippocampus Reveals Synaptic Dysfunction in Dravet Syndrome Mice. Front Mol Neurosci 2022; 15:823640. [PMID: 35370551 PMCID: PMC8966673 DOI: 10.3389/fnmol.2022.823640] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Dravet syndrome is severe childhood-onset epilepsy, caused by loss of function mutations in the SCN1A gene, encoding for the voltage-gated sodium channel NaV1.1. The leading hypothesis is that Dravet is caused by selective reduction in the excitability of inhibitory neurons, due to hampered activity of NaV1.1 channels in these cells. However, these initial neuronal changes can lead to further network alterations. Here, focusing on the CA1 microcircuit in hippocampal brain slices of Dravet syndrome (DS, Scn1aA1783V/WT) and wild-type (WT) mice, we examined the functional response to the application of Hm1a, a specific NaV1.1 activator, in CA1 stratum-oriens (SO) interneurons and CA1 pyramidal excitatory neurons. DS SO interneurons demonstrated reduced firing and depolarized threshold for action potential (AP), indicating impaired activity. Nevertheless, Hm1a induced a similar AP threshold hyperpolarization in WT and DS interneurons. Conversely, a smaller effect of Hm1a was observed in CA1 pyramidal neurons of DS mice. In these excitatory cells, Hm1a application resulted in WT-specific AP threshold hyperpolarization and increased firing probability, with no effect on DS neurons. Additionally, when the firing of SO interneurons was triggered by CA3 stimulation and relayed via activation of CA1 excitatory neurons, the firing probability was similar in WT and DS interneurons, also featuring a comparable increase in the firing probability following Hm1a application. Interestingly, a similar functional response to Hm1a was observed in a second DS mouse model, harboring the nonsense Scn1aR613X mutation. Furthermore, we show homeostatic synaptic alterations in both CA1 pyramidal neurons and SO interneurons, consistent with reduced excitation and inhibition onto CA1 pyramidal neurons and increased release probability in the CA1-SO synapse. Together, these results suggest global neuronal alterations within the CA1 microcircuit extending beyond the direct impact of NaV1.1 dysfunction.
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Affiliation(s)
- Yael Almog
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Anat Mavashov
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
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8
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Chronic partial TrkB activation reduces seizures and mortality in a mouse model of Dravet syndrome. Proc Natl Acad Sci U S A 2022; 119:2022726119. [PMID: 35165147 PMCID: PMC8851461 DOI: 10.1073/pnas.2022726119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2021] [Indexed: 12/03/2022] Open
Abstract
Dravet syndrome (DS) is a severe childhood epileptic encephalopathy characterized by intractable seizures and comorbidities, including a high rate of premature mortality. DS is mainly caused by loss-of-function mutations of the Scn1a gene encoding sodium channel Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, causing DS phenotypes. Effective pharmacological therapy targeting defective PV interneurons is currently not available. This study demonstrated that early treatment with a partial TrkB receptor agonist, LM22A-4, increased Nav1.1 expression, improved PV interneuron function, and reduced seizure occurrence and mortality rate in DS mice, suggesting a potential therapy for DS. Dravet syndrome (DS) is one of the most severe childhood epilepsies, characterized by intractable seizures and comorbidities including cognitive and social dysfunction and high premature mortality. DS is mainly caused by loss-of-function mutations in the Scn1a gene encoding Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, contributing to DS phenotypes. Effective pharmacological therapy that targets defective PV interneurons is not available. The known role of brain-derived neurotrophic factor (BDNF) in the development and maintenance of interneurons, together with our previous results showing improved PV interneuronal function and antiepileptogenic effects of a TrkB receptor agonist in a posttraumatic epilepsy model, led to the hypothesis that early treatment with a TrkB receptor agonist might prevent or reduce seizure activity in DS mice. To test this hypothesis, we treated DS mice with LM22A-4 (LM), a partial agonist at the BDNF TrkB receptor, for 7 d starting at postnatal day 13 (P13), before the onset of spontaneous seizures. Results from immunohistochemistry, Western blot, whole-cell patch-clamp recording, and in vivo seizure monitoring showed that LM treatment increased the number of perisomatic PV interneuronal synapses around cortical pyramidal cells in layer V, upregulated Nav1.1 in PV neurons, increased inhibitory synaptic transmission, and decreased seizures and the mortality rate in DS mice. The results suggest that early treatment with a partial TrkB receptor agonist may be a promising therapeutic approach to enhance PV interneuron function and reduce epileptogenesis and premature death in DS.
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9
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Huang CH, Hung PL, Fan PC, Lin KL, Hsu TR, Chou IJ, Ho CS, Chou IC, Lin WS, Lee IC, Fan HC, Chen SJ, Liang JS, Tu YF, Chang TM, Hu SC, Wong LC, Hung KL, Lee WT. Clinical spectrum and the comorbidities of Dravet syndrome in Taiwan and the possible molecular mechanisms. Sci Rep 2021; 11:20242. [PMID: 34642351 PMCID: PMC8511137 DOI: 10.1038/s41598-021-98517-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 09/03/2021] [Indexed: 11/09/2022] Open
Abstract
Dravet syndrome (DS) is an uncommon epilepsy syndrome that may negatively affect the patients and their caregivers. However, reliable and valid measures of its impact on caregivers and the characteristics of patients with DS in Taiwan are lacking. This study aimed to describe the characteristics of patients with DS and concerns of their caregivers and establish a baseline frequency of disease characteristics using a cross-sectional survey in Taiwan. We assessed the caregivers of patients with DS using an online anonymous questionnaire. The seizure frequency decreased with age, although lacking statistical significance. Vaccines show no influence on the condition of patients with DS. Our findings revealed the highest impact on the domains affecting the caregivers’ daily life, including additional household tasks, symptom observation, further medical plan, and financial issues. Caregivers also expressed concerns regarding the lack of independence/constant care, seizure control, speech/communication, and impacts on siblings because of long-term care of the patients in parents’ absence. Our findings highlight the significant effects of caring for a child with DS on the lives of their caregivers in Taiwan; these findings will help raise awareness regarding the needs of these families. Furthermore, we discussed the possible pathophysiological mechanisms of associated comorbidities.
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Affiliation(s)
- Chia-Hsuan Huang
- Division of Pediatric Neurology, Department of Pediatrics, National Taiwan University Hospital Yunlin Branch, Yunlin County, Taiwan
| | - Pi-Lien Hung
- Department of Pediatric Neurology, Chang Gung Memorial Hospital-Kaohsiung, Kaohsiung, Taiwan
| | - Pi-Chuan Fan
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Kuang-Lin Lin
- Division of Pediatric Neurology, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ting-Rong Hsu
- Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan
| | - I-Jun Chou
- Division of Pediatric Neurology, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Che-Sheng Ho
- Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan
| | - I-Ching Chou
- Division of Pediatrics Neurology, China Medical University Children's Hospital, Taichung, Taiwan
| | - Wei-Sheng Lin
- Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Inn-Chi Lee
- Institute of Medicine, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Hueng-Chuen Fan
- Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Taichung, Taiwan
| | - Shyi-Jou Chen
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Jao-Shwann Liang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Yi-Fang Tu
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tung-Ming Chang
- Department of Pediatric Neurology, Changhua Christian Children's Hospital, Changhua, Taiwan
| | - Su-Ching Hu
- Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan
| | - Lee-Chin Wong
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan
| | - Kun-Long Hung
- Department of Pediatrics, Fu-Jen Catholic University Hospital, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. .,Department of Pediatric Neurology, National Taiwan University Children's Hospital, 8, Chung-Shan South Road, Taipei, 100, Taiwan.
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10
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Hawkins NA, Jurado M, Thaxton TT, Duarte SE, Barse L, Tatsukawa T, Yamakawa K, Nishi T, Kondo S, Miyamoto M, Abrahams BS, During MJ, Kearney JA. Soticlestat, a novel cholesterol 24-hydroxylase inhibitor, reduces seizures and premature death in Dravet syndrome mice. Epilepsia 2021; 62:2845-2857. [PMID: 34510432 PMCID: PMC9291096 DOI: 10.1111/epi.17062] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Dravet syndrome is a severe developmental and epileptic encephalopathy (DEE) most often caused by de novo pathogenic variants in SCN1A. Individuals with Dravet syndrome rarely achieve seizure control and have significantly elevated risk for sudden unexplained death in epilepsy (SUDEP). Heterozygous deletion of Scn1a in mice (Scn1a+/- ) recapitulates several core phenotypes, including temperature-dependent and spontaneous seizures, SUDEP, and behavioral abnormalities. Furthermore, Scn1a+/- mice exhibit a similar clinical response to standard anticonvulsants. Cholesterol 24-hydroxlase (CH24H) is a brain-specific enzyme responsible for cholesterol catabolism. Recent research has indicated the therapeutic potential of CH24H inhibition for diseases associated with neural excitation, including seizures. METHODS In this study, the novel compound soticlestat, a CH24H inhibitor, was administered to Scn1a+/- mice to investigate its ability to improve Dravet-like phenotypes in this preclinical model. RESULTS Soticlestat treatment reduced seizure burden, protected against hyperthermia-induced seizures, and completely prevented SUDEP in Scn1a+/- mice. Video-electroencephalography (EEG) analysis confirmed the ability of soticlestat to reduce occurrence of electroclinical seizures. SIGNIFICANCE This study demonstrates that soticlestat-mediated inhibition of CH24H provides therapeutic benefit for the treatment of Dravet syndrome in mice and has the potential for treatment of DEEs.
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Affiliation(s)
- Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Manuel Jurado
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tyler T Thaxton
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Samantha E Duarte
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Levi Barse
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tetsuya Tatsukawa
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, Wako, Japan
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, Wako, Japan
| | - Toshiya Nishi
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | - Shinichi Kondo
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | - Maki Miyamoto
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | | | | | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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11
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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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12
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Goff KM, Goldberg EM. A Role for Vasoactive Intestinal Peptide Interneurons in Neurodevelopmental Disorders. Dev Neurosci 2021; 43:168-180. [PMID: 33794534 PMCID: PMC8440337 DOI: 10.1159/000515264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/10/2021] [Indexed: 11/19/2022] Open
Abstract
GABAergic inhibitory interneurons of the cerebral cortex expressing vasoactive intestinal peptide (VIP-INs) are rapidly emerging as important regulators of network dynamics and normal circuit development. Several recent studies have also identified VIP-IN dysfunction in models of genetically determined neurodevelopmental disorders (NDDs). In this article, we review the known circuit functions of VIP-INs and how they may relate to accumulating evidence implicating VIP-INs in the mechanisms of prominent NDDs. We highlight recurring VIP-IN-mediated circuit motifs that are shared across cerebral cortical areas and how VIP-IN activity can shape sensory input, development, and behavior. Ultimately, we extract a set of themes that inform our understanding of how VIP-INs influence pathogenesis of NDDs. Using publicly available single-cell RNA sequencing data from the Allen Institute, we also identify several underexplored disease-associated genes that are highly expressed in VIP-INs. We survey these genes and their shared related disease phenotypes that may broadly implicate VIP-INs in autism spectrum disorder and intellectual disability rather than epileptic encephalopathy. Finally, we conclude with a discussion of the relevance of cell type-specific investigations and therapeutics in the age of genomic diagnosis and targeted therapeutics.
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Affiliation(s)
- Kevin M Goff
- Medical Scientist Training Program (MSTP), The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Neuroscience Graduate Group, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ethan M Goldberg
- Neuroscience Graduate Group, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- The Epilepsy NeuroGenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Departments of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Departments of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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13
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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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14
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Lunardi P, Mansk LMZ, Jaimes LF, Pereira GS. On the novel mechanisms for social memory and the emerging role of neurogenesis. Brain Res Bull 2021; 171:56-66. [PMID: 33753208 DOI: 10.1016/j.brainresbull.2021.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/24/2021] [Accepted: 03/08/2021] [Indexed: 01/25/2023]
Abstract
Social memory (SM) is a key element in social cognition and it encompasses the neural representation of conspecifics, an essential information to guide behavior in a social context. Here we evaluate classical and cutting-edge studies on neurobiology of SM, using as a guiding principle behavioral tasks performed in adult rodents. Our review highlights the relevance of the hippocampus, especially the CA2 region, as a neural substrate for SM and suggest that neural ensembles in the olfactory bulb may also encode SM traces. Compared to other hippocampus-dependent memories, much remains to be done to describe the neurobiological foundations of SM. Nonetheless, we argue that special attention should be paid to neurogenesis. Finally, we pinpoint the remaining open question on whether the hippocampal adult neurogenesis acts through pattern separation to permit the discrimination of highly similar stimuli during behavior.
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Affiliation(s)
- Paula Lunardi
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lara M Z Mansk
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Laura F Jaimes
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Grace S Pereira
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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15
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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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16
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Satta V, Alonso C, Díez P, Martín-Suárez S, Rubio M, Encinas JM, Fernández-Ruiz J, Sagredo O. Neuropathological Characterization of a Dravet Syndrome Knock-In Mouse Model Useful for Investigating Cannabinoid Treatments. Front Mol Neurosci 2021; 13:602801. [PMID: 33584198 PMCID: PMC7879984 DOI: 10.3389/fnmol.2020.602801] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/30/2020] [Indexed: 12/24/2022] Open
Abstract
Dravet syndrome (DS) is an epileptic syndrome caused by mutations in the Scn1a gene encoding the α1 subunit of the sodium channel Nav1.1, which is associated with febrile seizures that progress to severe tonic-clonic seizures and associated comorbidities. Treatment with cannabidiol has been approved to reduce seizures in DS, but it may also be active against these comorbidities. The aim of this study was to validate a new mouse model of DS having lower mortality than previous models, which may serve to further evaluate therapies for the long-term comorbidities. This new model consists of heterozygous conditional knock-in mice carrying a missense mutation (A1783V) in Scn1a gene expressed exclusively in neurons of the CNS (Syn-Cre/Scn1aWT/A1783V). These mice have been used here to determine the extent and persistence of the behavioral deterioration in different postnatal days (PND), as well as to investigate the alterations that the disease produces in the endocannabinoid system and the contribution of inflammatory events and impaired neurogenesis in the pathology. Syn-Cre/Scn1aWT/A1783V mice showed a strong reduction in hindlimb grasp reflex at PND10, whereas at PND25, they presented spontaneous convulsions and a greater susceptibility to pentylenetetrazole-induced seizures, marked hyperactivity, deficient spatial working memory, lower levels of anxiety, and altered social interaction behavior. These differences disappeared at PND40 and PND60, except the changes in social interaction and anxiety. The analysis of CNS structures associated with these behavioral alterations revealed an elevated glial reactivity in the prefrontal cortex and the dentate gyrus. This was associated in the dentate gyrus with a greater cell proliferation detected with Ki67 immunostaining, whereas double-labeling analyses identified that proliferating cells were GFAP-positive suggesting failed neurogenesis but astrocyte proliferation. The analysis of the endocannabinoid system of Syn-Cre/Scn1aWT/A1783V mice confirmed reductions in CB1 receptors and MAGL and FAAH enzymes, mainly in the cerebellum but also in other areas, whereas CB2 receptors became upregulated in the hippocampus. In conclusion, Syn-Cre/Scn1aWT/A1783V mice showed seizuring susceptibility and several comorbidities (hyperactivity, memory impairment, less anxiety, and altered social behavior), which exhibited a pattern of age expression similar to DS patients. Syn-Cre/Scn1aWT/A1783V mice also exhibited greater glial reactivity and a reactive response in the neurogenic niche, and regional changes in the status of the endocannabinoid signaling, events that could contribute in behavioral impairment.
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Affiliation(s)
- Valentina Satta
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Cristina Alonso
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Paula Díez
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Soraya Martín-Suárez
- The NSC Cell and Neurogenesis Laboratory, Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Marta Rubio
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Juan M Encinas
- The NSC Cell and Neurogenesis Laboratory, Achucarro Basque Center for Neuroscience, Leioa, Spain.,The University of the Basque Country (UPV/EHU), Leioa, Spain.,IKERBASQUE, The Basque Foundation for Science, Bilbao, Spain
| | - Javier Fernández-Ruiz
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Onintza Sagredo
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
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17
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Shin S, Santi A, Huang S. Conditional Pten knockout in parvalbumin- or somatostatin-positive neurons sufficiently leads to autism-related behavioral phenotypes. Mol Brain 2021; 14:24. [PMID: 33504340 PMCID: PMC7839207 DOI: 10.1186/s13041-021-00731-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
Disrupted GABAergic neurons have been extensively described in brain tissues from individuals with autism spectrum disorder (ASD) and animal models for ASD. However, the contribution of these aberrant inhibitory neurons to autism-related behavioral phenotypes is not well understood. We examined ASD-related behaviors in mice with conditional Pten knockout in parvalbumin (PV)-expressing or somatostatin (Sst)-expressing neurons, two common subtypes of GABAergic neurons. We found that mice with deletion of Pten in either PV-neurons or Sst-neurons displayed social deficits, repetitive behaviors and impaired motor coordination/learning. In addition, mice with one copy of Pten deletion in PV-neurons exhibited hyperlocomotion in novel open fields and home cages. We also examined anxiety behaviors and found that mice with Pten deletion in Sst-neurons displayed anxiety-like behaviors, while mice with Pten deletion in PV-neurons exhibited anxiolytic-like behaviors. These behavioral assessments demonstrate that Pten knockout in the subtype of inhibitory neurons sufficiently gives rise to ASD-core behaviors, providing evidence that both PV- and Sst-neurons may play a critical role in ASD symptoms.
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Affiliation(s)
- Sangyep Shin
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD 21201 USA
| | - Andrea Santi
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD 21201 USA
| | - Shiyong Huang
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD 21201 USA
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18
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Richards K, Jancovski N, Hanssen E, Connelly A, Petrou S. Atypical myelinogenesis and reduced axon caliber in the Scn1a variant model of Dravet syndrome: An electron microscopy pilot study of the developing and mature mouse corpus callosum. Brain Res 2020; 1751:147157. [PMID: 33069731 DOI: 10.1016/j.brainres.2020.147157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 11/24/2022]
Abstract
Dravet Syndrome (DS) is a genetic neurodevelopmental disease. Recurrent severe seizures begin in infancy and co-morbidities follow, including developmental delay, cognitive and behavioral dysfunction. A majority of DS patients have an SCN1A heterozygous gene mutation. This mutation causes a loss-of-function in inhibitory neurons, initiating seizure onset. We have investigated whether the sodium channelopathy may result in structural changes in the DS model independent of seizures. Morphometric analyses of axons within the corpus callosum were completed at P16 and P50 in Scn1a heterozygote KO male mice and their age-matched wild-type littermates. Trainable machine learning algorithms were used to examine electron microscopy images of ~400 myelinated axons per animal, per genotype, including myelinated axon cross-section area, frequency distribution and g-ratios. Pilot data for Scn1a heterozygote KO mice demonstrate the average axon caliber was reduced in developing and adult mice. Qualitative analysis also shows micro-features marking altered myelination at P16 in the DS model, with myelin out-folding and myelin debris within phagocytic cells. The data has indicated, in the absence of behavioral seizures, factors that governed a shift toward small calibre axons at P16 have persisted in adult Scn1a heterozygote KO corpus callosum. The pilot study provides a basis for future meta-analysis that will enable robust estimates of the effects of the sodium channelopathy on axon architecture. We propose that early therapeutic strategies in DS could help minimize the effect of sodium channelopathies, beyond the impact of overt seizures, and therefore achieve better long-term treatment outcomes.
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Affiliation(s)
- Kay Richards
- Florey Institute of Neuroscience and Mental Health, Australia
| | | | - Eric Hanssen
- Bio21 Advanced Microscopy Facility, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Australia
| | - Alan Connelly
- Florey Institute of Neuroscience and Mental Health, Australia; Florey Institute of Neuroscience and Mental Health, The Florey Department of Neuroscience and Mental Health, University of Melbourne, Australia
| | - Steve Petrou
- Florey Institute of Neuroscience and Mental Health, Australia.
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19
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Fadila S, Quinn S, Turchetti Maia A, Yakubovich D, Ovadia M, Anderson KL, Giladi M, Rubinstein M. Convulsive seizures and some behavioral comorbidities are uncoupled in the
Scn1a
A1783V
Dravet syndrome mouse model. Epilepsia 2020; 61:2289-2300. [DOI: 10.1111/epi.16662] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 02/03/2023]
Affiliation(s)
- Saja Fadila
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Department of Human Molecular Genetics and Biochemistry Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Shir Quinn
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Department of Human Molecular Genetics and Biochemistry Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Ana Turchetti Maia
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Daniel Yakubovich
- Department of Physiology and Pharmacology Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Schneider Children's Medical Center of Israel Petah Tikvah Israel
| | - Mor Ovadia
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Sagol School of Neuroscience Tel Aviv University Tel Aviv Israel
| | - Karen L. Anderson
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Moshe Giladi
- Department of Physiology and Pharmacology Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Moran Rubinstein
- Goldschleger Eye Research Institute Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Department of Human Molecular Genetics and Biochemistry Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Sagol School of Neuroscience Tel Aviv University Tel Aviv Israel
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20
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CRISPR/dCas9-based Scn1a gene activation in inhibitory neurons ameliorates epileptic and behavioral phenotypes of Dravet syndrome model mice. Neurobiol Dis 2020; 141:104954. [DOI: 10.1016/j.nbd.2020.104954] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/12/2023] Open
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21
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Electrophysiological Alterations of Pyramidal Cells and Interneurons of the CA1 Region of the Hippocampus in a Novel Mouse Model of Dravet Syndrome. Genetics 2020; 215:1055-1066. [PMID: 32554600 DOI: 10.1534/genetics.120.303399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/05/2020] [Indexed: 11/18/2022] Open
Abstract
Dravet syndrome is a developmental epileptic encephalopathy caused by pathogenic variation in SCN1A To characterize the pathogenic substitution (p.H939R) of a local individual with Dravet syndrome, fibroblast cells from the individual were reprogrammed to pluripotent stem cells and differentiated into neurons. Sodium currents of these neurons were compared with healthy control induced neurons. A novel Scn1a H939R/+ mouse model was generated with the p.H939R substitution. Immunohistochemistry and electrophysiological experiments were performed on hippocampal slices of Scn1a H939R/+ mice. We found that the sodium currents recorded in the proband-induced neurons were significantly smaller and slower compared to wild type (WT). The resting membrane potential and spike amplitude were significantly depolarized in the proband-induced neurons. Similar differences in resting membrane potential and spike amplitude were observed in the interneurons of the hippocampus of Scn1a H939R/+ mice. The Scn1a H939R/+ mice showed the characteristic features of a Dravet-like phenotype: increased mortality and both spontaneous and heat-induced seizures. Immunohistochemistry showed a reduction in amount of parvalbumin and vesicular acetylcholine transporter in the hippocampus of Scn1a H939R/+ compared to WT mice. Overall, these results underline hyper-excitability of the hippocampal CA1 circuit of this novel mouse model of Dravet syndrome which, under certain conditions, such as temperature, can trigger seizure activity. This hyper-excitability is due to the altered electrophysiological properties of pyramidal neurons and interneurons which are caused by the dysfunction of the sodium channel bearing the p.H939R substitution. This novel Dravet syndrome model also highlights the reduction in acetylcholine and the contribution of pyramidal cells, in addition to interneurons, to network hyper-excitability.
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22
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Sanchez REA, Bussi IL, Ben-Hamo M, Caldart CS, Catterall WA, De La Iglesia HO. Circadian regulation of sleep in a pre-clinical model of Dravet syndrome: dynamics of sleep stage and siesta re-entrainment. Sleep 2020; 42:5539047. [PMID: 31346614 DOI: 10.1093/sleep/zsz173] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/24/2019] [Indexed: 12/11/2022] Open
Abstract
STUDY OBJECTIVES Sleep disturbances are common co-morbidities of epileptic disorders. Dravet syndrome (DS) is an intractable epilepsy accompanied by disturbed sleep. While there is evidence that daily sleep timing is disrupted in DS, the difficulty of chronically recording polysomnographic sleep from patients has left our understanding of the effect of DS on circadian sleep regulation incomplete. We aim to characterize circadian sleep regulation in a mouse model of DS. METHODS Here we exploit long-term electrocorticographic recordings of sleep in a mouse model of DS in which one copy of the Scn1a gene is deleted. This model both genocopies and phenocopies the disease in humans. We test the hypothesis that the deletion of Scn1a in DS mice is associated with impaired circadian regulation of sleep. RESULTS We find that DS mice show impairments in circadian sleep regulation, including a fragmented rhythm of non-rapid eye movement (NREM) sleep and an elongated circadian period of sleep. Next, we characterize re-entrainment of sleep stages and siesta following jet lag in the mouse. Strikingly, we find that re-entrainment of sleep following jet lag is normal in DS mice, in contrast to previous demonstrations of slowed re-entrainment of wheel-running activity. Finally, we report that DS mice are more likely to have an absent or altered daily "siesta". CONCLUSIONS Our findings support the hypothesis that the circadian regulation of sleep is altered in DS and highlight the value of long-term chronic polysomnographic recording in studying the role of the circadian clock on sleep/wake cycles in pre-clinical models of disease.
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Affiliation(s)
- Raymond E A Sanchez
- Department of Biology, University of Washington, Seattle, WA.,Graduate Program in Neuroscience, University of Washington, Seattle WA
| | - Ivana L Bussi
- Department of Biology, University of Washington, Seattle, WA
| | - Miriam Ben-Hamo
- Department of Biology, University of Washington, Seattle, WA
| | | | - William A Catterall
- Graduate Program in Neuroscience, University of Washington, Seattle WA.,Department of Pharmacology, University of Washington, Seattle WA
| | - Horacio O De La Iglesia
- Department of Biology, University of Washington, Seattle, WA.,Graduate Program in Neuroscience, University of Washington, Seattle WA
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23
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Mantegazza M, Broccoli V. SCN1A/Na V 1.1 channelopathies: Mechanisms in expression systems, animal models, and human iPSC models. Epilepsia 2020; 60 Suppl 3:S25-S38. [PMID: 31904127 DOI: 10.1111/epi.14700] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/04/2019] [Indexed: 12/20/2022]
Abstract
Pathogenic SCN1A/NaV 1.1 mutations cause well-defined epilepsies, including genetic epilepsy with febrile seizures plus (GEFS+) and the severe epileptic encephalopathy Dravet syndrome. In addition, they cause a severe form of migraine with aura, familial hemiplegic migraine. Moreover, SCN1A/NaV 1.1 variants have been inferred as risk factors in other types of epilepsy. We review here the advancements obtained studying pathologic mechanisms of SCN1A/NaV 1.1 mutations with experimental systems. We present results gained with in vitro expression systems, gene-targeted animal models, and the induced pluripotent stem cell (iPSC) technology, highlighting advantages, limits, and pitfalls for each of these systems. Overall, the results obtained in the last two decades confirm that the initial pathologic mechanism of epileptogenic SCN1A/NaV 1.1 mutations is loss-of-function of NaV 1.1 leading to hypoexcitability of at least some types of γ-aminobutyric acid (GABA)ergic neurons (including cortical and hippocampal parvalbumin-positive and somatostatin-positive ones). Conversely, more limited results point to NaV 1.1 gain-of-function for familial hemiplegic migraine (FHM) mutations. Behind these relatively simple pathologic mechanisms, an unexpected complexity has been observed, in part generated by technical issues in experimental studies and in part related to intrinsically complex pathophysiologic responses and remodeling, which yet remain to be fully disentangled.
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Affiliation(s)
- Massimo Mantegazza
- University Cote d'Azur (UCA), CNRS UMR7275, INSERM, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Vania Broccoli
- San Raffaele Scientific Institute, Milan, Italy.,Institute of Neuroscience, National Research Council (CNR), Milan, Italy
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24
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Colasante G, Lignani G, Brusco S, Di Berardino C, Carpenter J, Giannelli S, Valassina N, Bido S, Ricci R, Castoldi V, Marenna S, Church T, Massimino L, Morabito G, Benfenati F, Schorge S, Leocani L, Kullmann DM, Broccoli V. dCas9-Based Scn1a Gene Activation Restores Inhibitory Interneuron Excitability and Attenuates Seizures in Dravet Syndrome Mice. Mol Ther 2020; 28:235-253. [PMID: 31607539 PMCID: PMC6952031 DOI: 10.1016/j.ymthe.2019.08.018] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 01/05/2023] Open
Abstract
Dravet syndrome (DS) is a severe epileptic encephalopathy caused mainly by heterozygous loss-of-function mutations of the SCN1A gene, indicating haploinsufficiency as the pathogenic mechanism. Here we tested whether catalytically dead Cas9 (dCas9)-mediated Scn1a gene activation can rescue Scn1a haploinsufficiency in a mouse DS model and restore physiological levels of its gene product, the Nav1.1 voltage-gated sodium channel. We screened single guide RNAs (sgRNAs) for their ability to stimulate Scn1a transcription in association with the dCas9 activation system. We identified a specific sgRNA that increases Scn1a gene expression levels in cell lines and primary neurons with high specificity. Nav1.1 protein levels were augmented, as was the ability of wild-type immature GABAergic interneurons to fire action potentials. A similar enhancement of Scn1a transcription was achieved in mature DS interneurons, rescuing their ability to fire. To test the therapeutic potential of this approach, we delivered the Scn1a-dCas9 activation system to DS pups using adeno-associated viruses. Parvalbumin interneurons recovered their firing ability, and febrile seizures were significantly attenuated. Our results pave the way for exploiting dCas9-based gene activation as an effective and targeted approach to DS and other disorders resulting from altered gene dosage.
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Affiliation(s)
- Gaia Colasante
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Simone Brusco
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Claudia Di Berardino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Jenna Carpenter
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Serena Giannelli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Nicholas Valassina
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Simone Bido
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Raffaele Ricci
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Valerio Castoldi
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Silvia Marenna
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Timothy Church
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Luca Massimino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Giuseppe Morabito
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy; IRCCS Ospedale Policlinico San Martino, University of Genova, 16132 Genova, Italy
| | - Stephanie Schorge
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Letizia Leocani
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy; CNR Institute of Neuroscience, 20129 Milan, Italy.
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25
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White CM, Rees CL, Wheeler DW, Hamilton DJ, Ascoli GA. Molecular expression profiles of morphologically defined hippocampal neuron types: Empirical evidence and relational inferences. Hippocampus 2019; 30:472-487. [PMID: 31596053 PMCID: PMC7875254 DOI: 10.1002/hipo.23165] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/14/2019] [Accepted: 08/22/2019] [Indexed: 12/12/2022]
Abstract
Gene and protein expressions are key determinants of cellular function. Neurons are the building blocks of brain circuits, yet the relationship between their molecular identity and the spatial distribution of their dendritic inputs and axonal outputs remains incompletely understood. The open-source knowledge base Hippocampome.org amasses such transcriptomic data from the scientific literature for morphologically defined neuron types in the rodent hippocampal formation: dentate gyrus, CA3, CA2, CA1, subiculum, and entorhinal cortex. Positive, negative, or mixed expression reports were initially obtained from published articles directly connecting molecular evidence to neurons with known axonal and dendritic patterns across hippocampal layers. Here, we supplement this information by collating, formalizing, and leveraging relational expression inferences that link a gene or protein expression or lack thereof to that of another molecule or to an anatomical location. With these additional interpretations, we freely release online a comprehensive human- and machine-readable molecular profile for more than 100 neuron types in Hippocampome.org. Analysis of these data ascertains the ability to distinguish unequivocally most neuron types in each of the major subdivisions of the hippocampus based on currently known biochemical markers. Moreover, grouping neuron types by expression similarity reveals eight superfamilies characterized by a few defining molecules.
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Affiliation(s)
- Charise M White
- Center for Neural Informatics, Structure, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
| | - Christopher L Rees
- Center for Neural Informatics, Structure, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
| | - Diek W Wheeler
- Center for Neural Informatics, Structure, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
| | - David J Hamilton
- Center for Neural Informatics, Structure, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
| | - Giorgio A Ascoli
- Center for Neural Informatics, Structure, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
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26
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Friedman LK, Wongvravit JP. Anticonvulsant and Neuroprotective Effects of Cannabidiol During the Juvenile Period. J Neuropathol Exp Neurol 2019; 77:904-919. [PMID: 30169677 DOI: 10.1093/jnen/nly069] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Anticonvulsant effects of cannabidiol (CBD), a nonpsychoactive cannabinoid, have not been investigated in the juvenile brain. We hypothesized that CBD would attenuate epileptiform activity at an age when the brain first becomes vulnerable to neurotoxicity and social/cognitive impairments. To induce seizures, kainic acid (KA) was injected either into the hippocampus (KAih) or systemically (KAip) on postnatal (P) day 20. CBD was coadministered (KA + CBDih, KA + CBDip) or injected 30 minutes postseizure onset (KA/CBDih, KA/CBDip). Hyperactivity, clonic convulsions, and electroencephalogram rhythmic oscillations were attenuated or absent after KA + CBDih and reduced after KA + CBDip. NeuN immunohistochemistry revealed neuroprotection. Augmented reactive glia number and expression were reversed in CA1 but persisted deep within the dentate hilus. Parvalbumin-positive (PV+) interneurons were reduced in both models, whereas immunolabeling was dramatically increased within ipsilateral and contralateral dendritic/neuropilar fields following KA + CBDih. Cannabinoid receptor 1 (CB1) expression was minimally affected after KAih contrasting elevations observed after KAip. Intracranial coadministration data suggest that CBD has higher efficacy in epilepsy with hippocampal focus rather than when extrahippocampal amygdala/cortical structures are triggered by systemic treatments. Inhibition of surviving PV+ and CB1+ interneurons may be facilitated by CBD implying a protective role in regulating hippocampal seizures and neurotoxicity at juvenile ages.
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Affiliation(s)
- Linda K Friedman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
| | - Joann P Wongvravit
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
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27
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Ricobaraza A, Mora-Jimenez L, Puerta E, Sanchez-Carpintero R, Mingorance A, Artieda J, Nicolas MJ, Besne G, Bunuales M, Gonzalez-Aparicio M, Sola-Sevilla N, Valencia M, Hernandez-Alcoceba R. Epilepsy and neuropsychiatric comorbidities in mice carrying a recurrent Dravet syndrome SCN1A missense mutation. Sci Rep 2019; 9:14172. [PMID: 31578435 PMCID: PMC6775062 DOI: 10.1038/s41598-019-50627-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/11/2019] [Indexed: 11/30/2022] Open
Abstract
Dravet Syndrome (DS) is an encephalopathy with epilepsy associated with multiple neuropsychiatric comorbidities. In up to 90% of cases, it is caused by functional happloinsufficiency of the SCN1A gene, which encodes the alpha subunit of a voltage-dependent sodium channel (Nav1.1). Preclinical development of new targeted therapies requires accessible animal models which recapitulate the disease at the genetic and clinical levels. Here we describe that a C57BL/6 J knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V) presents a full spectrum of DS manifestations. This includes 70% mortality rate during the first 8 weeks of age, reduced threshold for heat-induced seizures (4.7 °C lower compared with control littermates), cognitive impairment, motor disturbances, anxiety, hyperactive behavior and defects in the interaction with the environment. In contrast, sociability was relatively preserved. Electrophysiological studies showed spontaneous interictal epileptiform discharges, which increased in a temperature-dependent manner. Seizures were multifocal, with different origins within and across individuals. They showed intra/inter-hemispheric propagation and often resulted in generalized tonic-clonic seizures. 18F-labelled flourodeoxyglucose positron emission tomography (FDG-PET) revealed a global increase in glucose uptake in the brain of Scn1aWT/A1783V mice. We conclude that the Scn1aWT/A1783V model is a robust research platform for the evaluation of new therapies against DS.
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Affiliation(s)
- Ana Ricobaraza
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain.
| | - Lucia Mora-Jimenez
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Elena Puerta
- University of Navarra, Department of Pharmacology and Toxicology, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | | | - Julio Artieda
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Neurophysiology Service, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain
| | - Maria Jesus Nicolas
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Guillermo Besne
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Maria Bunuales
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Noemi Sola-Sevilla
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Miguel Valencia
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
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Impairment of Sharp-Wave Ripples in a Murine Model of Dravet Syndrome. J Neurosci 2019; 39:9251-9260. [PMID: 31537705 DOI: 10.1523/jneurosci.0890-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 11/21/2022] Open
Abstract
Dravet syndrome (DS) is a severe early-onset epilepsy associated with heterozygous loss-of-function mutations in SCN1A Animal models of DS with global Scn1a haploinsufficiency recapitulate the DS phenotype, including seizures, premature death, and impaired spatial memory performance. Spatial memory requires hippocampal sharp-wave ripples (SPW-Rs), which consist of high-frequency field potential oscillations (ripples, 100-260 Hz) superimposed on a slower SPW. Published in vitro electrophysiologic recordings in DS mice demonstrate reduced firing of GABAergic inhibitory neurons, which are essential for the formation of SPW-R complexes. Here, in vivo electrophysiologic recordings of hippocampal local field potential in both male and female mice demonstrate that Scn1a haploinsufficiency slows intrinsic ripple frequency and reduces the rate of SPW-R occurrence. In DS mice, peak ripple-band power is shifted to lower frequencies, average intertrough intervals of individually detected ripples are slower, and the rate of SPW-R generation is reduced, while SPW amplitude remains unaffected. These alterations in SPW-R properties, in combination with published reductions in interneuron function in DS, suggest a direct link between reduced inhibitory neuron excitability and impaired SPW-R function. A simple interconnected, conductance-based in silico interneuron network model was used to determine whether reduced sodium conductance is sufficient to slow ripple frequency, and stimulation with a modeled SPW demonstrates that reduced sodium conductance alone is sufficient to slow oscillatory frequencies. These findings forge a potential mechanistic link between impaired SPW-R generation and Scn1a mutation in DS mice, expanding the set of disorders in which SPW-R dysfunction contributes to impaired memory.SIGNIFICANCE STATEMENT Disruption of sharp-wave ripples, a characteristic hippocampal rhythm coordinated by the precise timing of GABAergic interneurons, impairs spatial learning and memory. Prior in vitro patch-clamp recordings in brain slices from genetic mouse models of Dravet syndrome (DS) reveal reduced sodium current and excitability in GABAergic interneurons but not excitatory cells, suggesting a causal role for impaired interneuron activity in seizures and cognitive impairment. Here, heterozygous Scn1a mutation in DS mice reduces hippocampal sharp-wave ripple occurrence and slows internal ripple frequency in vivo and a simple in silico model demonstrates reduction in interneuron function alone is sufficient to slow model oscillations. Together, these findings provide a plausible pathophysiologic mechanism for Scn1a gene mutation to impair spatial memory.
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Hippocampal deletion of Na V1.1 channels in mice causes thermal seizures and cognitive deficit characteristic of Dravet Syndrome. Proc Natl Acad Sci U S A 2019; 116:16571-16576. [PMID: 31346088 DOI: 10.1073/pnas.1906833116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dravet Syndrome is a severe childhood epileptic disorder caused by haploinsufficiency of the SCN1A gene encoding brain voltage-gated sodium channel NaV1.1. Symptoms include treatment-refractory epilepsy, cognitive impairment, autistic-like behavior, and premature death. The specific loci of NaV1.1 function in the brain that underlie these global deficits remain unknown. Here we specifically deleted Scn1a in the hippocampus using the Cre-Lox method in weanling mice. Local gene deletion caused selective reduction of inhibitory neurotransmission measured in dentate granule cells. Mice with local NaV1.1 reduction had thermally evoked seizures and spatial learning deficits, but they did not have abnormalities of locomotor activity or social interaction. Our results show that local gene deletion in the hippocampus can induce two of the most severe dysfunctions of Dravet Syndrome: Epilepsy and cognitive deficit. Considering these results, the hippocampus may be a potential target for future gene therapy for Dravet Syndrome.
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30
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Exploration of Ion Channels in the Clitoris: a Review. CURRENT SEXUAL HEALTH REPORTS 2019. [DOI: 10.1007/s11930-019-00206-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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A more efficient conditional mouse model of Dravet syndrome: Implications for epigenetic selection and sex-dependent behaviors. J Neurosci Methods 2019; 325:108315. [PMID: 31265868 DOI: 10.1016/j.jneumeth.2019.108315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 06/13/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND Dravet Syndrome (DS) is an epileptic disorder characterized by spontaneous and thermally-induced seizures, hyperactivity, cognitive deficits, autistic-like behaviors, and Sudden Unexpected Death in Epilepsy (SUDEP). DS is caused by de novo loss-of-function mutations in the SCN1A gene. Selective loss of GABAergic interneuron excitability is the primary cause of the disease. Up to 60% of Scn1a+/- mice die from SUDEP before sexual maturity. NEW METHOD We used Cre-Lox technology to conditionally delete Scn1a in all epiblast-derived somatic cells by crossing a floxed Scn1a mouse with a mouse expressing Cre under the Meox2 promoter. RESULTS Parental Scn1a flox (F) mice, parental Meox2 Cre+ mice, and their F/+:Meox2-Cre- offspring were phenotypically normal and did not prematurely die. In contrast, F/+:Meox2-Cre+ offspring recapitulated DS seizure and behavioral phenotypes. Unexpectedly, male F/+:Meox2-Cre+ mice demonstrated impaired social interaction, while females did not. COMPARISON WITH EXISTING METHOD In the previous models, colony maintenance required breeding SUDEP survivors, which greatly increased colony size required to sustain experimental animal production, and raised the concern that surviving breeders have epigenetic traits that impart new phenotypes to their offspring. Our method greatly facilitates breeding, recapitulates DS phenotypes, eliminates concerns about parents that are survivors, and provides initial evidence for unexpected sex-dependent social interaction impairment. CONCLUSIONS We introduce a more efficient mouse model of human DS that demonstrates an efficient breeding strategy free from potential inherited epigenetic changes and reveals an unexpected sex-specific impairment of social interaction in DS. This new model should have great value to investigators of DS.
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Ouss L, Leunen D, Laschet J, Chemaly N, Barcia G, Losito EM, Aouidad A, Barrault Z, Desguerre I, Breuillard D, Nabbout R. Autism spectrum disorder and cognitive profile in children with Dravet syndrome: Delineation of a specific phenotype. Epilepsia Open 2019; 4:40-53. [PMID: 30868114 PMCID: PMC6398110 DOI: 10.1002/epi4.12281] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/27/2018] [Accepted: 09/30/2018] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE We aimed to assess a cohort of young patients with Dravet syndrome (DS) for intellectual disability (ID) and autism spectrum disorder (ASD) using standardized tools and parental questionnaires to delineate their specific profiles. METHODS We included 35 patients with DS aged 24 months to 7 years, excluding patients with a developmental age (DA) <18 months (n = 5). We performed specific tests adapted for ID (Psychoeducational Profile, Third Edition [PEP-3]), in addition to the Child Development Inventory (CDI) and Vineland Adaptive Behavior Scales, Second Edition (VABS-II) questionnaires. We used 2 standardized tools for ASD: the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R). We compared the with parental questionnaires and the VABS-II, and with ASD characteristics. RESULTS PEP-3 subscales showed pathologic development in all but one patient (97%): ID in 23 of 30 (77%), and borderline cognitive functioning in 6 of 30 (22%). Eleven patients (39%) had ASD and 2 (7%) had a Social Communication Disorder (SCD) diagnosis. We found no difference between PEP-3 and CDI categorization except for fine motor skills. We found significant negative correlations between ADOS-2 and PEP-3 for the majority of scores. For patients aged older than 50 months, 2 groups emerged (ASD/no ASD) with significant difference in DA. The logistic regression for ASD diagnosis explained by VABS-II showed a significant effect for Socialization, Motor Skills, and Adaptive Behavior. SIGNIFICANCE We found a high prevalence of ID in patients with DS. ID is characterized by expressive and comprehensive communication deficits in addition to visuospatial difficulties. ASD showed a specific profile with a relative preservation of social skills, emphasizing a possible underdiagnosis. Parental questionnaires can provide a good assessment of cognitive profile and might allow the difficulty of addressing cognitive scales in DS to be overcome. The profile of ID and ASD should help to establish early adapted rehabilitation programs and emphasizes the global need for care beyond seizures in DS and other developmental epileptic encephalopathies.
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Affiliation(s)
- Lisa Ouss
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
- Child Psychiatry UnitNecker Enfants Malades HospitalParisFrance
| | - Dorothee Leunen
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
- Child Psychiatry UnitNecker Enfants Malades HospitalParisFrance
| | - Jacques Laschet
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Nicole Chemaly
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Giulia Barcia
- Department of Medical GeneticsNecker Enfants Malades HospitalAPHPParisFrance
| | - Emma M. Losito
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Aveline Aouidad
- Department of Child and Adolescent PsychiatryAPHPPitié‐Salpêtrière HospitalParisFrance
| | - Zoe Barrault
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Isabelle Desguerre
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Delphine Breuillard
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
| | - Rima Nabbout
- Reference Centre for Rare EpilepsiesDepartment of Pediatric NeurologyNecker Enfants Malades HospitalAPHPParis Descartes UniversityImagine InstituteParisFrance
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Downregulation of Npas4 in parvalbumin interneurons and cognitive deficits after neonatal NMDA receptor blockade: relevance for schizophrenia. Transl Psychiatry 2019; 9:99. [PMID: 30792384 PMCID: PMC6385315 DOI: 10.1038/s41398-019-0436-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/29/2019] [Accepted: 02/12/2019] [Indexed: 12/17/2022] Open
Abstract
Dysfunction of prefrontal parvalbumin (PV+) interneurons has been linked with severe cognitive deficits as observed in several neurodevelopmental disorders including schizophrenia. However, whether a specific aspect of PV+ neurons deregulation, or a specific molecular mechanism within PV+ neurons is responsible for cognitive deficits and other behavioral impairments remain to be determined. Here, we induced cognitive deficits and altered the prefrontal PV system in mice by exposing them neonatally to the NMDA receptor antagonist ketamine. We observed that the cognitive deficits and hyperactivity induced by neonatal ketamine were associated with a downregulation of Npas4 expression specifically in PV+ neurons. To determine whether Npas4 downregulation-induced dysfunction of PV+ neurons could be a molecular contributor to the cognitive and behavioral impairments reported after neonatal ketamine, we used a transgenic Cre-Lox approach. Reduced Npas4 expression within PV+ neurons replicates deficits in short-term memory observed after neonatal ketamine, but does not reproduce disturbances in general activity. Our data show for the first time that the brain-specific transcription factor Npas4 may be an important contributor to PV+ neurons dysfunction in neurodevelopmental disorders, and thereby could contribute to the cognitive deficits observed in diseases characterized by abnormal functioning of PV+ neurons such as schizophrenia. These findings provide a potential novel therapeutic target to rescue the cognitive impairments of schizophrenia that remain to date unresponsive to treatments.
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Lee S, Lee E, Kim R, Kim J, Lee S, Park H, Yang E, Kim H, Kim E. Shank2 Deletion in Parvalbumin Neurons Leads to Moderate Hyperactivity, Enhanced Self-Grooming and Suppressed Seizure Susceptibility in Mice. Front Mol Neurosci 2018; 11:209. [PMID: 29970987 PMCID: PMC6018407 DOI: 10.3389/fnmol.2018.00209] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/28/2018] [Indexed: 01/05/2023] Open
Abstract
Shank2 is an abundant postsynaptic scaffolding protein implicated in neurodevelopmental and psychiatric disorders, including autism spectrum disorders (ASD). Deletion of Shank2 in mice has been shown to induce social deficits, repetitive behaviors, and hyperactivity, but the identity of the cell types that contribute to these phenotypes has remained unclear. Here, we report a conditional mouse line with a Shank2 deletion restricted to parvalbumin (PV)-positive neurons (Pv-Cre;Shank2fl/fl mice). These mice display moderate hyperactivity in both novel and familiar environments and enhanced self-grooming in novel, but not familiar, environments. In contrast, they showed normal levels of social interaction, anxiety-like behavior, and learning and memory. Basal brain rhythms in Pv-Cre;Shank2fl/fl mice, measured by electroencephalography, were normal, but susceptibility to pentylenetetrazole (PTZ)-induced seizures was decreased. These results suggest that Shank2 deletion in PV-positive neurons leads to hyperactivity, enhanced self-grooming and suppressed brain excitation.
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Affiliation(s)
- Seungjoon Lee
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
| | - Eunee Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Ryunhee Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
| | - Jihye Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
| | - Esther Yang
- Department of Anatomy, College of Medicine, Korea University, Seoul, South Korea
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University, Seoul, South Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
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35
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Griffin A, Hamling KR, Hong S, Anvar M, Lee LP, Baraban SC. Preclinical Animal Models for Dravet Syndrome: Seizure Phenotypes, Comorbidities and Drug Screening. Front Pharmacol 2018; 9:573. [PMID: 29915537 PMCID: PMC5994396 DOI: 10.3389/fphar.2018.00573] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/14/2018] [Indexed: 12/18/2022] Open
Abstract
Epilepsy is a common chronic neurological disease affecting almost 3 million people in the United States and 50 million people worldwide. Despite availability of more than two dozen FDA-approved anti-epileptic drugs (AEDs), one-third of patients fail to receive adequate seizure control. Specifically, pediatric genetic epilepsies are often the most severe, debilitating and pharmaco-resistant forms of epilepsy. Epileptic syndromes share a common symptom of unprovoked seizures. While some epilepsies/forms of epilepsy are the result of acquired insults such as head trauma, febrile seizure, or viral infection, others have a genetic basis. The discovery of epilepsy associated genes suggests varied underlying pathologies and opens the door for development of new "personalized" treatment options for each genetic epilepsy. Among these, Dravet syndrome (DS) has received substantial attention for both the pre-clinical and early clinical development of novel therapeutics. Despite these advances, there is no FDA-approved treatment for DS. Over 80% of patients diagnosed with DS carry a de novo mutation within the voltage-gated sodium channel gene SCN1A and these patients suffer with drug resistant and life-threatening seizures. Here we will review the preclinical animal models for DS featuring inactivation of SCN1A (including zebrafish and mice) with an emphasis on seizure phenotypes and behavioral comorbidities. Because many drugs fail somewhere between initial preclinical discovery and clinical trials, it is equally important that we understand how these models respond to known AEDs. As such, we will also review the available literature and recent drug screening efforts using these models with a focus on assay protocols and predictive pharmacological profiles. Validation of these preclinical models is a critical step in our efforts to efficiently discover new therapies for these patients. The behavioral and electrophysiological drug screening assays in zebrafish will be discussed in detail including specific examples from our laboratory using a zebrafish scn1 mutant and a summary of the nearly 3000 drugs screened to date. As the discovery and development phase rapidly moves from the lab-to-the-clinic for DS, it is hoped that this preclinical strategy offers a platform for how to approach any genetic epilepsy.
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Affiliation(s)
- Aliesha Griffin
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Kyla R Hamling
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - SoonGweon Hong
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Mana Anvar
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Luke P Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Scott C Baraban
- Epilepsy Research Laboratory Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
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