1
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Reyes-Nava NG, Paz D, Pinales BE, Perez I, Gil CB, Gonzales AV, Grajeda BI, Estevao IL, Ellis CC, Castro VL, Quintana AM. Characterization of the zebrafish gabra1 sa43718/sa43718 germline loss of function allele confirms a function for Gabra1 in motility and nervous system development. Differentiation 2024; 138:100790. [PMID: 38908344 DOI: 10.1016/j.diff.2024.100790] [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: 06/05/2024] [Accepted: 06/13/2024] [Indexed: 06/24/2024]
Abstract
Mutation of the GABRA1 gene is associated with neurodevelopmental defects and epilepsy. GABRA1 encodes for the α1 subunit of the γ-aminobutyric acid type A receptor (GABAAR), which regulates the fast inhibitory impulses of the nervous system. Multiple model systems have been developed to understand the function of GABRA1, but these models have produced complex and, at times, incongruent data. Thus, additional model systems are required to validate and substantiate previous results. We sought to provide initial phenotypic analysis of a novel germline mutant allele. Our analysis provides a solid foundation for the future use of this allele to characterize gabra1 functionally and pharmacologically using zebrafish. We investigated the behavioral swim patterns associated with a nonsense mutation of the zebrafish gabra1 (sa43718 allele) gene. The sa43718 allele causes a decrease in gabra1 mRNA expression, which is associated with light induced hypermotility, one phenotype previously associated with seizure like behavior in zebrafish. Mutation of gabra1 was accompanied by decreased mRNA expression of gabra2, gabra3, and gabra5, indicating a reduction in the expression of additional α sub-units of the GABAAR. Although multiple sub-units were decreased, larvae continued to respond to pentylenetetrazole (PTZ), indicating that a residual GABAAR exists in the sa43718 allele. Proteomics analysis demonstrated that mutation of gabra1 is associated with abnormal expression of proteins that regulate synaptic vesicle fusion, vesicle transport, synapse development, and mitochondrial protein complexes. These data support previous studies performed in a zebrafish nonsense allele created by CRISPR/Cas9 and validate that loss of function mutations in the gabra1 gene result in seizure-like phenotypes with abnormal development of the GABA synapse. Our results add to the existing body of knowledge as to the function of GABRA1 during development and validate that zebrafish can be used to provide complete functional characterization of the gene.
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Affiliation(s)
- Nayeli G Reyes-Nava
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - David Paz
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Briana E Pinales
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Isaiah Perez
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Claudia B Gil
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Annalise V Gonzales
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Brian I Grajeda
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Igor L Estevao
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Cameron C Ellis
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Victoria L Castro
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA
| | - Anita M Quintana
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA.
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2
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Ren B, Wu X, Zhou Y, Chen L, Jiang J. SYN1 variant causes X-linked neurodevelopmental disorders: a case report of variable clinical phenotypes in siblings. Front Neurol 2024; 15:1359287. [PMID: 38576531 PMCID: PMC10991737 DOI: 10.3389/fneur.2024.1359287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/08/2024] [Indexed: 04/06/2024] Open
Abstract
The SYN1 gene encodes synapsin I, variants within the SYN1 gene are linked to X-linked neurodevelopmental disorders with high clinical heterogeneity, with reflex epilepsies (REs) being a representative clinical manifestation. This report analyzes a Chinese pedigree affected by seizures associated with SYN1 variants and explores the genotype-phenotype correlation. The proband, a 9-year-old boy, experienced seizures triggered by bathing at the age of 3, followed by recurrent absence seizures, behavioral issues, and learning difficulties. His elder brother exhibited a distinct clinical phenotype, experiencing sudden seizures during sleep at the age of 16, accompanied by hippocampal sclerosis. Whole exome sequencing (WES) confirmed a pathogenic SYN1 variant, c.1647_1650dup (p. Ser551Argfs*134), inherited in an X-linked manner from their mother. Notably, this variant displayed diverse clinical phenotypes in the two brothers and one previously reported case in the literature. Retrospective examination of SYN1 variants revealed an association between truncating variants and the pathogenicity of REs, and non-truncating variants are more related to developmental delay/intellectual disability (DD/ID). In summary, this study contributes to understanding complex neurodevelopmental disorders associated with SYN1, highlighting the clinical heterogeneity of gene variants and emphasizing the necessity for comprehensive genetic analysis in elucidating the pathogenic mechanisms of such diseases.
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Affiliation(s)
- Bin Ren
- Shanghai Nyuen Biotechnology Co., Ltd., Shanghai, China
| | - Xiaoyan Wu
- Shanghai Nyuen Biotechnology Co., Ltd., Shanghai, China
| | - Yuqiang Zhou
- Shanghai Nyuen Biotechnology Co., Ltd., Shanghai, China
| | - Lijuan Chen
- Shanghai Nyuen Biotechnology Co., Ltd., Shanghai, China
| | - Jingzi Jiang
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin, China
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3
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Paz D, Reyes-Nava NG, Pinales BE, Perez I, Gil CB, Gonzales AV, Grajeda B, Estevao IL, Ellis CC, Castro VL, Quintana AM. Characterization of the zebrafish gabra1sa43718/sa43718 germline loss of function allele confirms a function for Gabra1 in motility and nervous system development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525860. [PMID: 36747751 PMCID: PMC9900897 DOI: 10.1101/2023.01.27.525860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mutation of the GABRA1 gene is associated with neurodevelopmental defects and epilepsy. GABRA1 encodes for the α1 subunit of the gamma-aminobutyric acid type A receptor (GABAAR), which regulates the fast inhibitory impulses of the nervous system. Multiple model systems have previously been developed to understand the function of GABRA1 during development, but these models have produced complex and at times incongruent data. Thus, additional model systems are required to validate and substantiate previously published results. We investigated the behavioral swim patterns associated with a nonsense mutation of the zebrafish gabra1 (sa43718 allele) gene. The sa43718 allele causes a decrease in gabra1 mRNA expression, which is associated with light induced hypermotility, one phenotype associated with seizure like behavior in zebrafish. Mutation of gabra1 was accompanied by decreased mRNA expression of gabra2, gabra3, and gabra5, indicating a reduction in the expression of additional alpha sub-units of the GABAAR. Although multiple sub-units were decreased in total expression, larvae continued to respond to pentylenetetrazole (PTZ) indicating that a residual GABAAR exists in the sa43718 allele. Proteomics analysis demonstrated that nonsense mutation of gabra1 is associated with abnormal expression of proteins that regulate proton transport, ion homeostasis, vesicle transport, and mitochondrial protein complexes. These data support previous studies performed in a zebrafish nonsense allele created by CRISPR/Cas9 and validate that loss of function mutations in the gabra1 gene result in seizure like phenotypes with abnormal function of inhibitory synapses.
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Affiliation(s)
- David Paz
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Nayeli G Reyes-Nava
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Briana E Pinales
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Isaiah Perez
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Claudia B Gil
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Annalise V Gonzales
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Brian Grajeda
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Igor L Estevao
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Cameron C Ellis
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Victoria L Castro
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
| | - Anita M Quintana
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
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4
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Bünger I, Makridis KL, Kreye J, Nikolaus M, Sedlin E, Ullrich T, Hoffmann C, Tromm JV, Rasmussen HF, Milovanovic D, Höltje M, Prüss H, Kaindl AM. Maternal synapsin autoantibodies are associated with neurodevelopmental delay. Front Immunol 2023; 14:1101087. [PMID: 36742338 PMCID: PMC9893770 DOI: 10.3389/fimmu.2023.1101087] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/04/2023] [Indexed: 01/20/2023] Open
Abstract
Maternal autoantibodies can be transmitted diaplacentally, with potentially deleterious effects on neurodevelopment. Synapsin 1 (SYN1) is a neuronal protein that is important for synaptic communication and neuronal plasticity. While monoallelic loss of function (LoF) variants in the SYN1 gene result in X-linked intellectual disability (ID), learning disabilities, epilepsy, behavioral problems, and macrocephaly, the effect of SYN1 autoantibodies on neurodevelopment remains unclear. We recruited a clinical cohort of 208 mothers and their children with neurologic abnormalities and analyzed the role of maternal SYN1 autoantibodies. We identified seropositivity in 9.6% of mothers, and seropositivity was associated with an increased risk for ID and behavioral problems. Furthermore, children more frequently had epilepsy, macrocephaly, and developmental delay, in line with the SYN1 LoF phenotype. Whether SYN1 autoantibodies have a direct pathogenic effect on neurodevelopment or serve as biomarkers requires functional experiments.
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Affiliation(s)
- Isabel Bünger
- Charité - Universitätsmedizin Berlin, Department of Neurology and Experimental Neurology, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
| | - Konstantin L Makridis
- Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany.,Charité - Universitätsmedizin Berlin, German Epilepsy Center for Children and Adolescents, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Berlin, Germany
| | - Jakob Kreye
- Charité - Universitätsmedizin Berlin, Department of Neurology and Experimental Neurology, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany.,Charité - Universitätsmedizin Berlin, German Epilepsy Center for Children and Adolescents, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Marc Nikolaus
- Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany.,Charité - Universitätsmedizin Berlin, German Epilepsy Center for Children and Adolescents, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Eva Sedlin
- Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | - Tim Ullrich
- Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | - Christian Hoffmann
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
| | | | - Helle Foverskov Rasmussen
- Charité - Universitätsmedizin Berlin, Department of Neurology and Experimental Neurology, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
| | | | - Markus Höltje
- Charité - Universitätsmedizin Berlin, Institute of Integrative Neuroanatomy, Berlin, Germany
| | - Harald Prüss
- Charité - Universitätsmedizin Berlin, Department of Neurology and Experimental Neurology, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
| | - Angela M Kaindl
- Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany.,Charité - Universitätsmedizin Berlin, German Epilepsy Center for Children and Adolescents, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Berlin, Germany
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5
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Parenti I, Leitão E, Kuechler A, Villard L, Goizet C, Courdier C, Bayat A, Rossi A, Julia S, Bruel AL, Tran Mau-Them F, Nambot S, Lehalle D, Willems M, Lespinasse J, Ghoumid J, Caumes R, Smol T, El Chehadeh S, Schaefer E, Abi-Warde MT, Keren B, Afenjar A, Tabet AC, Levy J, Maruani A, Aledo-Serrano Á, Garming W, Milleret-Pignot C, Chassevent A, Koopmans M, Verbeek NE, Person R, Belles R, Bellus G, Salbert BA, Kaiser FJ, Mazzola L, Convers P, Perrin L, Piton A, Wiegand G, Accogli A, Brancati F, Benfenati F, Chatron N, Lewis-Smith D, Thomas RH, Zara F, Striano P, Lesca G, Depienne C. The different clinical facets of SYN1-related neurodevelopmental disorders. Front Cell Dev Biol 2022; 10:1019715. [PMID: 36568968 PMCID: PMC9773998 DOI: 10.3389/fcell.2022.1019715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/20/2022] [Indexed: 12/13/2022] Open
Abstract
Synapsin-I (SYN1) is a presynaptic phosphoprotein crucial for synaptogenesis and synaptic plasticity. Pathogenic SYN1 variants are associated with variable X-linked neurodevelopmental disorders mainly affecting males. In this study, we expand on the clinical and molecular spectrum of the SYN1-related neurodevelopmental disorders by describing 31 novel individuals harboring 22 different SYN1 variants. We analyzed newly identified as well as previously reported individuals in order to define the frequency of key features associated with these disorders. Specifically, behavioral disturbances such as autism spectrum disorder or attention deficit hyperactivity disorder are observed in 91% of the individuals, epilepsy in 82%, intellectual disability in 77%, and developmental delay in 70%. Seizure types mainly include tonic-clonic or focal seizures with impaired awareness. The presence of reflex seizures is one of the most representative clinical manifestations related to SYN1. In more than half of the cases, seizures are triggered by contact with water, but other triggers are also frequently reported, including rubbing with a towel, fever, toothbrushing, fingernail clipping, falling asleep, and watching others showering or bathing. We additionally describe hyperpnea, emotion, lighting, using a stroboscope, digestive troubles, and defecation as possible triggers in individuals with SYN1 variants. The molecular spectrum of SYN1 variants is broad and encompasses truncating variants (frameshift, nonsense, splicing and start-loss variants) as well as non-truncating variants (missense substitutions and in-frame duplications). Genotype-phenotype correlation revealed that epileptic phenotypes are enriched in individuals with truncating variants. Furthermore, we could show for the first time that individuals with early seizures onset tend to present with severe-to-profound intellectual disability, hence highlighting the existence of an association between early seizure onset and more severe impairment of cognitive functions. Altogether, we present a detailed clinical description of the largest series of individuals with SYN1 variants reported so far and provide the first genotype-phenotype correlations for this gene. A timely molecular diagnosis and genetic counseling are cardinal for appropriate patient management and treatment.
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Affiliation(s)
- Ilaria Parenti
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Elsa Leitão
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Laurent Villard
- INSERM, MMG, Faculté de Médecine, Aix-Marseille University, Marseille, France,Département de Génétique Médicale, APHM, Hôpital d'Enfants de La Timone, Marseille, France
| | - Cyril Goizet
- Service de Génétique Médicale, Bordeaux, France,Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France,NRGEN Team, INCIA, CNRS UMR 5287, University of Bordeaux, Bordeaux, France
| | - Cécile Courdier
- Service de Génétique Médicale, Bordeaux, France,Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France,NRGEN Team, INCIA, CNRS UMR 5287, University of Bordeaux, Bordeaux, France
| | - Allan Bayat
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark,Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Alessandra Rossi
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark,Pediatric Clinic, IRCCS Policlinico San Matteo Foundation, University of Pavia, Pavia, Italy
| | - Sophie Julia
- Service de Génétique Médicale, Pôle de Biologie, CHU de Toulouse - Hôpital Purpan, Toulouse, France
| | - Ange-Line Bruel
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France,UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Frédéric Tran Mau-Them
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France,UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Sophie Nambot
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Daphné Lehalle
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France,UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Marjolaine Willems
- Department of Medical Genetics, Rare diseases and Personalized Medicine, CHU Montpellier, University of Montpellier, Montpellier, France,Inserm U1298, INM, CHU Montpellier, University of Montpellier, Montpellier, France
| | - James Lespinasse
- Service de Cytogenetique, Centre Hospitalier de Chambéry, Chambéry, France
| | - Jamal Ghoumid
- Univ. Lille, ULR7364 RADEME, Lille, France,CHU Lille, Clinique de Génétique, Guy Fontaine, Lille, France
| | - Roseline Caumes
- Univ. Lille, ULR7364 RADEME, Lille, France,CHU Lille, Clinique de Génétique, Guy Fontaine, Lille, France
| | - Thomas Smol
- Univ. Lille, ULR7364 RADEME, Lille, France,CHU Lille, Institut de Génétique Médicale, Lille, France
| | - Salima El Chehadeh
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Elise Schaefer
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | | | - Boris Keren
- APHP, Département de Génétique, UF de Génomique du Développement, Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - Alexandra Afenjar
- Département de Génétique, Centre de Référence déficiences Intellectuelles de Causes Rares, APHP, Hôpital Armand Trousseau, Sorbonne Université, Paris, France
| | | | - Jonathan Levy
- APHP, Département de Génétique, Hôpital Robert-Debré, Paris, France
| | - Anna Maruani
- Department of Child and Adolescent Psychiatry, Robert Debré Hospital, APHP, Paris, France
| | - Ángel Aledo-Serrano
- Epilepsy and Neurogenetics Program, Neurology Department, Ruber Internacional Hospital, Madrid, Spain
| | - Waltraud Garming
- Sozialpädiatrisches Zentrum, Kinder-und Jugendklinik Gelsenkirchen, Gelsenkirchen, Germany
| | | | - Anna Chassevent
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Marije Koopmans
- Department of Genetics, Utrecht University Medical Center, Utrecht, Netherlands
| | - Nienke E. Verbeek
- Department of Genetics, Utrecht University Medical Center, Utrecht, Netherlands
| | | | - Rebecca Belles
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Gary Bellus
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Bonnie A. Salbert
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Frank J. Kaiser
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany,Essener Zentrum für Seltene Erkrankungen (EZSE), Universitätsklinikum Essen, Essen, Germany
| | - Laure Mazzola
- Department of Neurology, University Hospital, Lyon Neuroscience Research Center (CRNL), INSERM U1028, CNRS UMR5292, Lyon, France,Department of Neurology, University Hospital, Saint-Etienne, France
| | - Philippe Convers
- Department of Neurology, University Hospital, Lyon Neuroscience Research Center (CRNL), INSERM U1028, CNRS UMR5292, Lyon, France,Department of Neurology, University Hospital, Saint-Etienne, France
| | - Laurine Perrin
- Department of Paediatric Physical Medicine and Rehabilitation, CHU Saint-Étienne, Hôpital Bellevue, Rhône-Alpes Reference Centre for Neuromuscular Diseases, Saint-Étienne, France
| | - Amélie Piton
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France,Université de Strasbourg, Illkirch, France
| | - Gert Wiegand
- Division of Pediatric Neurology, Department of Pediatrics, Asklepios Klinik Nord-Heidberg, Hamburg, Germany,Department of Pediatric and Adolescent Medicine II (Neuropediatrics, Social Pediatrics), University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - Andrea Accogli
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre, Montreal, Qc, Canada,Department of Human Genetics, Faculty of Medicine, McGill University, Montreal, Qc, Canada
| | - Francesco Brancati
- Department of Life, Human Genetics, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy,IRCCS San Raffaele Roma, Rome, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Geneva, Italy,IRCCS Ospedale Policlinico San Martino, Geneva, Italy
| | - Nicolas Chatron
- Service de Genetique, Hospices Civils de Lyon, Bron, France,Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261 -INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
| | - David Lewis-Smith
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom,Department of Clinical Neurosciences, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom
| | - Rhys H. Thomas
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom,Department of Clinical Neurosciences, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom
| | - Federico Zara
- IRCCS G. Gaslini, Genova, Italy,Department of Neurology, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Pasquale Striano
- IRCCS G. Gaslini, Genova, Italy,Department of Neurology, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Gaetan Lesca
- Service de Genetique, Hospices Civils de Lyon, Bron, France,Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261 -INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany,*Correspondence: Christel Depienne,
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6
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Zou YF, Zhang SY, Li LW, Jing K, Xia L, Sun CX, Wu B. Hub genes for early diagnosis and therapy of adamantinomatous craniopharyngioma. Medicine (Baltimore) 2022; 101:e30278. [PMID: 36123899 PMCID: PMC9478218 DOI: 10.1097/md.0000000000030278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Adamantinomatous craniopharyngioma (ACP) is a subtype of craniopharyngioma, a neoplastic disease with a benign pathological phenotype but a poor prognosis in the sellar region. The disease has been considered the most common congenital tumor in the skull. Therefore, this article aims to identify hub genes that might serve as genetic markers of diagnosis, treatment, and prognosis of ACP. METHODS The procedure of this research includes the acquisition of public data, identification and functional annotation of differentially expressed genes (DEGs), construction and analysis of protein-protein interaction network, and the mining and analysis of hub genes by Spearman-rho test, multivariable linear regression, and receiver operator characteristic curve analysis. Quantitative real-time polymerase chain reaction was used to detect the level of mRNA of relative genes. RESULTS Among 2 datasets, a total of 703 DEGs were identified, mainly enriched in chemical synaptic transmission, cell adhesion, odontogenesis of the dentin-containing tooth, cell junction, extracellular region, extracellular space, structural molecule activity, and structural constituent of cytoskeleton. The protein-protein interaction network was composed of 4379 edges and 589 nodes. Its significant module had 10 hub genes, and SYN1, SYP, and GRIA2 were significantly down-regulated with ACP. CONCLUSION In a word, we find out the DEGs between ACP patients and standard samples, which are likely to play an essential role in the development of ACP. At the same time, these DEGs are of great value in tumors' diagnosis and targeted therapy and could even be mined as biological molecular targets for diagnosing and treating ACP patients.
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Affiliation(s)
- Yang-Fan Zou
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Shu-Yuan Zhang
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Li-Weng Li
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Kai Jing
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Liang Xia
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Cai-Xing Sun
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
| | - Bin Wu
- Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, China
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Hangzhou, China
- *Correspondence: Bin Wu, Department of Neurosurgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China (e-mail: )
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7
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Moreira DDP, Suzuki AM, Silva ALTE, Varella-Branco E, Meneghetti MCZ, Kobayashi GS, Fogo M, Ferrari MDFR, Cardoso RR, Lourenço NCV, Griesi-Oliveira K, Zachi EC, Bertola DR, Weinmann KDS, de Lima MA, Nader HB, Sertié AL, Passos-Bueno MR. Neuroprogenitor Cells From Patients With TBCK Encephalopathy Suggest Deregulation of Early Secretory Vesicle Transport. Front Cell Neurosci 2022; 15:803302. [PMID: 35095425 PMCID: PMC8793280 DOI: 10.3389/fncel.2021.803302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Biallelic pathogenic variants in TBCK cause encephaloneuropathy, infantile hypotonia with psychomotor retardation, and characteristic facies 3 (IHPRF3). The molecular mechanisms underlying its neuronal phenotype are largely unexplored. In this study, we reported two sisters, who harbored biallelic variants in TBCK and met diagnostic criteria for IHPRF3. We provided evidence that TBCK may play an important role in the early secretory pathway in neuroprogenitor cells (iNPC) differentiated from induced pluripotent stem cells (iPSC). Lack of functional TBCK protein in iNPC is associated with impaired endoplasmic reticulum-to-Golgi vesicle transport and autophagosome biogenesis, as well as altered cell cycle progression and severe impairment in the capacity of migration. Alteration in these processes, which are crucial for neurogenesis, neuronal migration, and cytoarchitecture organization, may represent an important causative mechanism of both neurodevelopmental and neurodegenerative phenotypes observed in IHPRF3. Whether reduced mechanistic target of rapamycin (mTOR) signaling is secondary to impaired TBCK function over other secretory transport regulators still needs further investigation.
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Affiliation(s)
- Danielle de Paula Moreira
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Angela May Suzuki
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | | | - Elisa Varella-Branco
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | | | - Gerson Shigeru Kobayashi
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Mariana Fogo
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
- Instituto de Ensino e Pesquisa Albert Einstein, Albert Einstein Hospital, São Paulo, Brazil
| | | | - Rafaela Regina Cardoso
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Naila Cristina Vilaça Lourenço
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Karina Griesi-Oliveira
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
- Instituto de Ensino e Pesquisa Albert Einstein, Albert Einstein Hospital, São Paulo, Brazil
| | - Elaine Cristina Zachi
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Débora Romeo Bertola
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
- Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Karina de Souza Weinmann
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Marcelo Andrade de Lima
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Helena Bonciani Nader
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Andrea Laurato Sertié
- Instituto de Ensino e Pesquisa Albert Einstein, Albert Einstein Hospital, São Paulo, Brazil
| | - Maria Rita Passos-Bueno
- Centro de Pesquisas Sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
- *Correspondence: Maria Rita Passos-Bueno,
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8
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Moschetta M, Ravasenga T, De Fusco A, Maragliano L, Aprile D, Orlando M, Sacchetti S, Casagrande S, Lignani G, Fassio A, Baldelli P, Benfenati F. Ca 2+ binding to synapsin I regulates resting Ca 2+ and recovery from synaptic depression in nerve terminals. Cell Mol Life Sci 2022; 79:600. [PMID: 36409372 PMCID: PMC9678998 DOI: 10.1007/s00018-022-04631-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/23/2022] [Accepted: 11/13/2022] [Indexed: 11/22/2022]
Abstract
Synapsin I (SynI) is a synaptic vesicle (SV)-associated phosphoprotein that modulates neurotransmission by controlling SV trafficking. The SynI C-domain contains a highly conserved ATP binding site mediating SynI oligomerization and SV clustering and an adjacent main Ca2+ binding site, whose physiological role is unexplored. Molecular dynamics simulations revealed that the E373K point mutation irreversibly deletes Ca2+ binding to SynI, still allowing ATP binding, but inducing a destabilization of the SynI oligomerization interface. Here, we analyzed the effects of this mutation on neurotransmitter release and short-term plasticity in excitatory and inhibitory synapses from primary hippocampal neurons. Patch-clamp recordings showed an increase in the frequency of miniature excitatory postsynaptic currents (EPSCs) that was totally occluded by exogenous Ca2+ chelators and associated with a constitutive increase in resting terminal Ca2+ concentrations. Evoked EPSC amplitude was also reduced, due to a decreased readily releasable pool (RRP) size. Moreover, in both excitatory and inhibitory synapses, we observed a marked impaired recovery from synaptic depression, associated with impaired RRP refilling and depletion of the recycling pool of SVs. Our study identifies SynI as a novel Ca2+ buffer in excitatory terminals. Blocking Ca2+ binding to SynI results in higher constitutive Ca2+ levels that increase the probability of spontaneous release and disperse SVs. This causes a decreased size of the RRP and an impaired recovery from depression due to the failure of SV reclustering after sustained high-frequency stimulation. The results indicate a physiological role of Ca2+ binding to SynI in the regulation of SV clustering and trafficking in nerve terminals.
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Affiliation(s)
- Matteo Moschetta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Tiziana Ravasenga
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Antonio De Fusco
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Davide Aprile
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,Present Address: High-Definition Disease Modelling Lab, Campus IFOM-IEO, Milan, Italy
| | - Marta Orlando
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Present Address: Charitè Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Germany
| | - Silvio Sacchetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Silvia Casagrande
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Gabriele Lignani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Present Address: Queens Square Institute of Neurology, University College London, London, UK
| | - Anna Fassio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
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9
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Longhena F, Faustini G, Brembati V, Pizzi M, Benfenati F, Bellucci A. An updated reappraisal of synapsins: structure, function and role in neurological and psychiatric disorders. Neurosci Biobehav Rev 2021; 130:33-60. [PMID: 34407457 DOI: 10.1016/j.neubiorev.2021.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023]
Abstract
Synapsins (Syns) are phosphoproteins strongly involved in neuronal development and neurotransmitter release. Three distinct genes SYN1, SYN2 and SYN3, with elevated evolutionary conservation, have been described to encode for Synapsin I, Synapsin II and Synapsin III, respectively. Syns display a series of common features, but also exhibit distinctive localization, expression pattern, post-translational modifications (PTM). These characteristics enable their interaction with other synaptic proteins, membranes and cytoskeletal components, which is essential for the proper execution of their multiple functions in neuronal cells. These include the control of synapse formation and growth, neuron maturation and renewal, as well as synaptic vesicle mobilization, docking, fusion, recycling. Perturbations in the balanced expression of Syns, alterations of their PTM, mutations and polymorphisms of their encoding genes induce severe dysregulations in brain networks functions leading to the onset of psychiatric or neurological disorders. This review presents what we have learned since the discovery of Syn I in 1977, providing the state of the art on Syns structure, function, physiology and involvement in central nervous system disorders.
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Affiliation(s)
- Francesca Longhena
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Viviana Brembati
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Marina Pizzi
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Fabio Benfenati
- Italian Institute of Technology, Via Morego 30, Genova, Italy; IRCSS Policlinico San Martino Hospital, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Laboratory for Preventive and Personalized Medicine, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
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10
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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11
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Patzke C, Brockmann MM, Dai J, Gan KJ, Grauel MK, Fenske P, Liu Y, Acuna C, Rosenmund C, Südhof TC. Neuromodulator Signaling Bidirectionally Controls Vesicle Numbers in Human Synapses. Cell 2020; 179:498-513.e22. [PMID: 31585084 DOI: 10.1016/j.cell.2019.09.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/28/2019] [Accepted: 09/06/2019] [Indexed: 10/25/2022]
Abstract
Neuromodulators bind to pre- and postsynaptic G protein-coupled receptors (GPCRs), are able to quickly change intracellular cyclic AMP (cAMP) and Ca2+ levels, and are thought to play important roles in neuropsychiatric and neurodegenerative diseases. Here, we discovered in human neurons an unanticipated presynaptic mechanism that acutely changes synaptic ultrastructure and regulates synaptic communication. Activation of neuromodulator receptors bidirectionally controlled synaptic vesicle numbers within nerve terminals. This control correlated with changes in the levels of cAMP-dependent protein kinase A-mediated phosphorylation of synapsin-1. Using a conditional deletion approach, we reveal that the neuromodulator-induced control of synaptic vesicle numbers was largely dependent on synapsin-1. We propose a mechanism whereby non-phosphorylated synapsin-1 "latches" synaptic vesicles to presynaptic clusters at the active zone. cAMP-dependent phosphorylation of synapsin-1 then removes the vesicles. cAMP-independent dephosphorylation of synapsin-1 in turn recruits vesicles. Synapsin-1 thereby bidirectionally regulates synaptic vesicle numbers and modifies presynaptic neurotransmitter release as an effector of neuromodulator signaling in human neurons.
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Affiliation(s)
- Christopher Patzke
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA.
| | - Marisa M Brockmann
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Jinye Dai
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Kathlyn J Gan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - M Katharina Grauel
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Pascal Fenske
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Yu Liu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Claudio Acuna
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Christian Rosenmund
- Institut für Neurophysiologie, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
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12
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Beretta S, Gritti L, Verpelli C, Sala C. Eukaryotic Elongation Factor 2 Kinase a Pharmacological Target to Regulate Protein Translation Dysfunction in Neurological Diseases. Neuroscience 2020; 445:42-49. [PMID: 32088293 DOI: 10.1016/j.neuroscience.2020.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 02/02/2023]
Abstract
Two major processes tightly regulate protein synthesis, the initiation of mRNA translation and elongation phase that mediates the movement of ribosomes along the mRNA. The elongation phase is a high energy-consuming process, and is mainly regulated by the eukaryotic elongation factor 2 kinase (eEF2K) activity that phosphorylates and inhibits eEF2, the only known substrate of the kinase. eEF2K activity is closely regulated by several signaling pathways because the translation elongation phase strongly influences the cellular energy demand and can change the expression of specific proteins in different tissues. An increasing number of recent findings link eEF2k over activation to an array of human diseases, such as atherosclerosis, pulmonary arterial hypertension, progression of solid tumors, and some major neurological disorders. Several neurological studies suggest that eEF2K is a valuable target in treating epilepsy, depression and major neurodegenerative diseases. Despite eEF2k is an ubiquitous and conserved protein, it has been proved that its deletion does not affect development in animal models and in general cell viability. Therefore, it is possible to postulate that inhibiting its function may not cause serious side effects. In addition, eEF2K is a peculiar kinase molecularly different from most of other mammalian kinases and new compounds that inhibit eEF2K should not necessarily interfere with other important protein kinases. In this review we will critically summarize the evidence supporting the role of the altered eEF2K/eEF2 pathway in defined neurological diseases and its implications in curing these diseases in animal models, and possibly in humans, by targeting eEF2K activity.
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Affiliation(s)
| | | | | | - Carlo Sala
- CNR Neuroscience Institute, Milano, Italy.
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13
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Forte N, Binda F, Contestabile A, Benfenati F, Baldelli P. Synapsin I Synchronizes GABA Release in Distinct Interneuron Subpopulations. Cereb Cortex 2019; 30:1393-1406. [DOI: 10.1093/cercor/bhz174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 01/28/2023] Open
Abstract
Abstract
Neurotransmitters can be released either synchronously or asynchronously with respect to action potential timing. Synapsins (Syns) are a family of synaptic vesicle (SV) phosphoproteins that assist gamma-aminobutyric acid (GABA) release and allow a physiological excitation/inhibition balance. Consistently, deletion of either or both Syn1 and Syn2 genes is epileptogenic. In this work, we have characterized the effect of SynI knockout (KO) in the regulation of GABA release dynamics. Using patch-clamp recordings in hippocampal slices, we demonstrate that the lack of SynI impairs synchronous GABA release via a reduction of the readily releasable SVs and, in parallel, increases asynchronous GABA release. The effects of SynI deletion on synchronous GABA release were occluded by ω-AgatoxinIVA, indicating the involvement of P/Q-type Ca2+channel-expressing neurons. Using in situ hybridization, we show that SynI is more expressed in parvalbumin (PV) interneurons, characterized by synchronous release, than in cholecystokinin or SOM interneurons, characterized by a more asynchronous release. Optogenetic activation of PV and SOM interneurons revealed a specific reduction of synchronous release in PV/SynIKO interneurons associated with an increased asynchronous release in SOM/SynIKO interneurons. The results demonstrate that SynI is differentially expressed in interneuron subpopulations, where it boosts synchronous and limits asynchronous GABA release.
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Affiliation(s)
- N Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - F Binda
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - A Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - F Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - P Baldelli
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
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14
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Lucchese G. Herpesviruses, autoimmunity and epilepsy: Peptide sharing and potential cross-reactivity with human synaptic proteins. Autoimmun Rev 2019; 18:102367. [PMID: 31404705 DOI: 10.1016/j.autrev.2019.102367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 12/11/2022]
Abstract
Aggregation of immuno-proteomic data reveals that i) herpesviruses and synaptic proteins -in particular Synapsin-1 and Bassoon - share a large number of hexapeptides that also recur in hundreds of epitopes experimentally validated as immunopositive in the human host, and ii) the shared peptides are also spread among human epilepsy-related proteins. The data indicate that cross-reactive processes may be associated with pathogenetic mechanisms in epilepsy, thus suggesting a role of autoimmunity in etiopathology of epilepsies after herpesvirus-infections.
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Affiliation(s)
- Guglielmo Lucchese
- University of Greifswald, Department of Neurology, Ferdinand-Sauerbruch-Straße, Greifswald 17495, Germany; Goldsmiths, University of London, Department of Computing, Lewisham Way, New Cross, London SE14 6NW, United Kingdom.
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15
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Matos H, Quiles R, Andrade R, Bykhovskaia M. Growth and excitability at synapsin II deficient hippocampal neurons. Mol Cell Neurosci 2019; 96:25-34. [PMID: 30858140 DOI: 10.1016/j.mcn.2019.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/25/2019] [Accepted: 03/07/2019] [Indexed: 10/27/2022] Open
Abstract
Synapsins are neuronal phosphoproteins that fine-tune synaptic transmission and suppress seizure activity. Synapsin II (SynII) deletion produces epileptic seizures and overexcitability in neuronal networks. Early studies in primary neuronal cultures have shown that SynII deletion results in a delay in synapse formation. More recent studies at hippocampal slices have revealed increased spontaneous activity in SynII knockout (SynII(-)) mice. To reconcile these observations, we systematically re-examined synaptic transmission, synapse formation, and neurite growth in primary hippocampal neuronal cultures. We find that spontaneous glutamatergic synaptic activity was suppressed in SynII(-) neurons during the initial developmental epoch (7 days in vitro, DIV) but was enhanced at later times (12 and18 DIV). The density of synapses, transmission between connected pairs of neurons, and the number of docked synaptic vesicles were not affected by SynII deletion. However, we found that neurite outgrowth in SynII(-) neurons was suppressed during the initial developmental epoch (7 DIV) but enhanced at subsequent developmental stages (12 and18 DIV). This finding can account for the observed effect of SynII deletion on synaptic activity. To test whether the observed phenotype resulted directly from the deletion of SynII we expressed SynII in SynII(-) cultures using an adeno-associated virus (AAV). Expression of SynII at 2 DIV rescued the SynII deletion-dependent alterations in both synaptic activity and neuronal growth. To test whether the increased neurite outgrowth in SynII(-) observed at DIV 12 and18 represents an overcompensation for the initial developmental delay or results directly from SynII deletion we performed "late expression" experiments, transfecting SynII(-) cultures with AAV at 7 DIV. The late SynII expression suppressed neurite outgrowth at 12 and 18 DIV to the levels observed in control neurons, suggesting that these phenotypes directly depend on SynII. These results reveal a novel developmentally regulated role for SynII function in the control of neurite growth.
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Affiliation(s)
- Heidi Matos
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Raymond Quiles
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Rodrigo Andrade
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Maria Bykhovskaia
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America.
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16
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Guarnieri FC, Pozzi D, Raimondi A, Fesce R, Valente MM, Delvecchio VS, Van Esch H, Matteoli M, Benfenati F, D'Adamo P, Valtorta F. A novel SYN1 missense mutation in non-syndromic X-linked intellectual disability affects synaptic vesicle life cycle, clustering and mobility. Hum Mol Genet 2018; 26:4699-4714. [PMID: 28973667 DOI: 10.1093/hmg/ddx352] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 08/29/2017] [Indexed: 01/04/2023] Open
Abstract
Intellectual Disability is a common and heterogeneous disorder characterized by limitations in intellectual functioning and adaptive behaviour, whose molecular mechanisms remain largely unknown. Among the numerous genes found to be involved in the pathogenesis of intellectual disability, 10% are located on the X-chromosome. We identified a missense mutation (c.236 C > G; p.S79W) in the SYN1 gene coding for synapsin I in the MRX50 family, affected by non-syndromic X-linked intellectual disability. Synapsin I is a neuronal phosphoprotein involved in the regulation of neurotransmitter release and neuronal development. Several mutations in SYN1 have been identified in patients affected by epilepsy and/or autism. The S79W mutation segregates with the disease in the MRX50 family and all affected members display intellectual disability as sole clinical manifestation. At the protein level, the S79W Synapsin I mutation is located in the region of the B-domain involved in recognition of highly curved membranes. Expression of human S79W Synapsin I in Syn1 knockout hippocampal neurons causes aberrant accumulation of small clear vesicles in the soma, increased clustering of synaptic vesicles at presynaptic terminals and increased frequency of excitatory spontaneous release events. In addition, the presence of S79W Synapsin I strongly reduces the mobility of synaptic vesicles, with possible implications for the regulation of neurotransmitter release and synaptic plasticity. These results implicate SYN1 in the pathogenesis of non-syndromic intellectual disability, showing that alterations of synaptic vesicle trafficking are one possible cause of this disease, and suggest that distinct mutations in SYN1 may lead to distinct brain pathologies.
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Affiliation(s)
- Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.,San Raffaele Vita-Salute University, 20132 Milan, Italy
| | - Davide Pozzi
- Laboratory of Pharmacology and Brain Pathology, Humanitas Clinical and Research Center, 20089 Rozzano, Milan, Italy
| | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Riccardo Fesce
- Centre of Neuroscience and DISTA, University of Insubria, 21100 Varese, Italy
| | - Maria M Valente
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | | | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, B3000 Leuven, Belgium
| | - Michela Matteoli
- Laboratory of Pharmacology and Brain Pathology, Humanitas Clinical and Research Center, 20089 Rozzano, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Patrizia D'Adamo
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.,San Raffaele Vita-Salute University, 20132 Milan, Italy
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17
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Valente P, Farisello P, Valtorta F, Baldelli P, Benfenati F. Impaired GABA B-mediated presynaptic inhibition increases excitatory strength and alters short-term plasticity in synapsin knockout mice. Oncotarget 2017; 8:90061-90076. [PMID: 29163811 PMCID: PMC5685732 DOI: 10.18632/oncotarget.21405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/03/2017] [Indexed: 11/25/2022] Open
Abstract
Synapsins are a family of synaptic vesicle phosphoproteins regulating synaptic transmission and plasticity. SYN1/2 genes are major epilepsy susceptibility genes in humans. Consistently, synapsin I/II/III triple knockout (TKO) mice are epileptic and exhibit severe impairments in phasic and tonic GABAergic inhibition that precede the appearance of the epileptic phenotype. These changes are associated with an increased strength of excitatory transmission that has never been mechanistically investigated. Here, we observed that an identical effect in excitatory transmission could be induced in wild-type (WT) Schaffer collateral-CA1 pyramidal cell synapses by blockade of GABAB receptors (GABABRs). The same treatment was virtually ineffective in TKO slices, suggesting that the increased strength of the excitatory transmission results from an impairment of GABAB presynaptic inhibition. Exogenous stimulation of GABABRs in excitatory autaptic neurons, where GABA spillover is negligible, demonstrated that GABABRs were effective in inhibiting excitatory transmission in both WT and TKO neurons. These results demonstrate that the decreased GABA release and spillover, previously observed in TKO hippocampal slices, removes the tonic brake of presynaptic GABABRs on glutamate transmission, making the excitation/inhibition imbalance stronger.
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Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy
| | - Pasqualina Farisello
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Flavia Valtorta
- S. Raffaele Scientific Institute and Vita-Salute University, 20132 Milano, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
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18
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Mooney CM, Jimenez-Mateos EM, Engel T, Mooney C, Diviney M, Venø MT, Kjems J, Farrell MA, O'Brien DF, Delanty N, Henshall DC. RNA sequencing of synaptic and cytoplasmic Upf1-bound transcripts supports contribution of nonsense-mediated decay to epileptogenesis. Sci Rep 2017; 7:41517. [PMID: 28128343 PMCID: PMC5269742 DOI: 10.1038/srep41517] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/20/2016] [Indexed: 12/19/2022] Open
Abstract
The nonsense mediated decay (NMD) pathway is a critical surveillance mechanism for identifying aberrant mRNA transcripts. It is unknown, however, whether the NMD system is affected by seizures in vivo and whether changes confer beneficial or maladaptive responses that influence long-term outcomes such the network alterations that produce spontaneous recurrent seizures. Here we explored the responses of the NMD pathway to prolonged seizures (status epilepticus) and investigated the effects of NMD inhibition on epilepsy in mice. Status epilepticus led to increased protein levels of Up-frameshift suppressor 1 homolog (Upf1) within the mouse hippocampus. Upf1 protein levels were also higher in resected hippocampus from patients with intractable temporal lobe epilepsy. Immunoprecipitation of Upf1-bound RNA from the cytoplasmic and synaptosomal compartments followed by RNA sequencing identified unique populations of NMD-associated transcripts and altered levels after status epilepticus, including known substrates such as Arc as well as novel targets including Inhba and Npas4. Finally, long-term video-EEG recordings determined that pharmacologic interference in the NMD pathway after status epilepticus reduced the later occurrence of spontaneous seizures in mice. These findings suggest compartment-specific recruitment and differential loading of transcripts by NMD pathway components may contribute to the process of epileptogenesis.
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Affiliation(s)
- Claire M Mooney
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Catherine Mooney
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Mairead Diviney
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Morten T Venø
- Department of Molecular Biology and Genetics and Center for DNA Nanotechnology and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Jørgen Kjems
- Department of Molecular Biology and Genetics and Center for DNA Nanotechnology and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | | | | | | | - David C Henshall
- Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
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19
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Synapsin II Regulation of GABAergic Synaptic Transmission Is Dependent on Interneuron Subtype. J Neurosci 2017; 37:1757-1771. [PMID: 28087765 DOI: 10.1523/jneurosci.0844-16.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 12/22/2016] [Accepted: 12/31/2016] [Indexed: 11/21/2022] Open
Abstract
Synapsins are epilepsy susceptibility genes that encode phosphoproteins reversibly associated with synaptic vesicles. Synapsin II (SynII) gene deletion produces a deficit in inhibitory synaptic transmission, and this defect is thought to cause epileptic activity. We systematically investigated how SynII affects synchronous and asynchronous release components of inhibitory transmission in the CA1 region of the mouse hippocampus. We found that the asynchronous GABAergic release component is diminished in SynII-deleted (SynII(-)) slices. To investigate this defect at different interneuron subtypes, we selectively blocked either N-type or P/Q-type Ca2+ channels. SynII deletion suppressed the asynchronous release component at synapses dependent on N-type Ca2+ channels but not at synapses dependent on P/Q-type Ca2+ channels. We then performed paired double-patch recordings from inhibitory basket interneurons connected to pyramidal neurons and used cluster analysis to classify interneurons according to their spiking and synaptic parameters. We identified two cell subtypes, presumably parvalbumin (PV) and cholecystokinin (CCK) expressing basket interneurons. To validate our interneuron classification, we took advantage of transgenic animals with fluorescently labeled PV interneurons and confirmed that their spiking and synaptic parameters matched the parameters of presumed PV cells identified by the cluster analysis. The analysis of the release time course at the two interneuron subtypes demonstrated that the asynchronous release component was selectively reduced at SynII(-) CCK interneurons. In contrast, the transmission was desynchronized at SynII(-) PV interneurons. Together, our results demonstrate that SynII regulates the time course of GABAergic release, and that this SynII function is dependent on the interneuron subtype.SIGNIFICANCE STATEMENT Deletion of the neuronal protein synapsin II (SynII) leads to the development of epilepsy, probably due to impairments in inhibitory synaptic transmission. We systematically investigated SynII function at different subtypes of inhibitory neurons in the hippocampus. We discovered that SynII affects the time course of GABA release, and that this effect is interneuron subtype specific. Within one of the subtypes, SynII deficiency synchronizes the release and suppresses the asynchronous release component, while at the other subtype SynII deficiency suppresses the synchronous release component. These results reveal a new SynII function in the regulation of the time course of GABA release and demonstrate that this function is dependent on the interneuron subtype.
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20
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Subconvulsant doses of pentylenetetrazol uncover the epileptic phenotype of cultured synapsin-deficient Helix serotonergic neurons in the absence of excitatory and inhibitory inputs. Epilepsy Res 2016; 127:241-251. [PMID: 27639349 DOI: 10.1016/j.eplepsyres.2016.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/24/2016] [Accepted: 09/06/2016] [Indexed: 11/21/2022]
Abstract
Synapsins are a family of presynaptic proteins related to several processes of synaptic functioning. A variety of reports have linked mutations in synapsin genes with the development of epilepsy. Among the proposed mechanisms, a main one is based on the synapsin-mediated imbalance towards network hyperexcitability due to differential effects on neurotransmitter release in GABAergic and glutamatergic synapses. Along this line, a non-synaptic effect of synapsin depletion increasing neuronal excitability has recently been described in Helix neurons. To further investigate this issue, we examined the effect of synapsin knock-down on the development of pentylenetetrazol (PTZ)-induced epileptic-like activity using single neurons or isolated monosynaptic circuits reconstructed on microelectrode arrays (MEAs). Compared to control neurons, synapsin-silenced neurons showed a lower threshold for the development of epileptic-like activity and prolonged periods of activity, together with the occurrence of spontaneous firing after recurrent PTZ-induced epileptic-like activity. These findings highlight the crucial role of synapsin on neuronal excitability regulation in the absence of inhibitory or excitatory inputs.
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21
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Dynamin 1 isoform roles in a mouse model of severe childhood epileptic encephalopathy. Neurobiol Dis 2016; 95:1-11. [PMID: 27363778 DOI: 10.1016/j.nbd.2016.06.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/23/2016] [Accepted: 06/26/2016] [Indexed: 01/05/2023] Open
Abstract
Dynamin 1 is a large neuron-specific GTPase involved in the endocytosis and recycling of pre-synaptic membranes and synaptic vesicles. Mutations in the gene encoding dynamin 1 (DNM1) underlie two epileptic encephalopathy syndromes, Lennox-Gastaut Syndrome and Infantile Spasms. Mice homozygous for the Dnm1 "fitful" mutation, a non-synonymous coding variant in an alternatively spliced exon of Dnm1 (exon 10a; isoform designation: Dnm1a(Ftfl)) have an epileptic encephalopathy-like disorder including lethal early onset seizures, locomotor and neurosensory deficits. Although fitful heterozygotes have milder recurrent seizures later in life, suggesting an additive or semi-dominant mechanism, the molecular etiology must also consider the fact that Dnm1a(Ftfl) exerts a dominant negative effect on endocytosis in vitro. Another complication is that the fitful mutation induces alterations in the relative abundance of Dnm1 splice variants; mutants have a downregulation of Dnm1a and an upregulation of Dnm1b, changes which may contribute to the epileptic pathology. To examine whether Dnm1a loss of function, Dnm1a(Ftfl) dominance or compensation by Dnm1b is the most critical for severe seizures, we studied alternate isoform-specific mutant mice. Mice lacking Dnm1 exon 10a or Dnm1 exon 10b have neither spontaneous seizures nor other overt abnormalities, suggesting that in normal conditions the major role of each isoform is redundant. However, in the presence of Dnm1a(Ftfl) only exon 10a deleted mice experience severe seizures. These results reveal functional differences between Dnm1a and Dnm1b isoforms in the presence of a challenge, i.e. toxic Dnm1(Ftfl), while reinforcing its effect explicitly in this model of severe pediatric epilepsy.
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22
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Knock-down of synapsin alters cell excitability and action potential waveform by potentiating BK and voltage-gated Ca(2+) currents in Helix serotonergic neurons. Neuroscience 2015; 311:430-43. [PMID: 26522789 DOI: 10.1016/j.neuroscience.2015.10.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 09/23/2015] [Accepted: 10/25/2015] [Indexed: 11/21/2022]
Abstract
Synapsins (Syns) are an evolutionarily conserved family of presynaptic proteins crucial for the fine-tuning of synaptic function. A large amount of experimental evidences has shown that Syns are involved in the development of epileptic phenotypes and several mutations in Syn genes have been associated with epilepsy in humans and animal models. Syn mutations induce alterations in circuitry and neurotransmitter release, differentially affecting excitatory and inhibitory synapses, thus causing an excitation/inhibition imbalance in network excitability toward hyperexcitability that may be a determinant with regard to the development of epilepsy. Another approach to investigate epileptogenic mechanisms is to understand how silencing Syn affects the cellular behavior of single neurons and is associated with the hyperexcitable phenotypes observed in epilepsy. Here, we examined the functional effects of antisense-RNA inhibition of Syn expression on individually identified and isolated serotonergic cells of the Helix land snail. We found that Helix synapsin silencing increases cell excitability characterized by a slightly depolarized resting membrane potential, decreases the rheobase, reduces the threshold for action potential (AP) firing and increases the mean and instantaneous firing rates, with respect to control cells. The observed increase of Ca(2+) and BK currents in Syn-silenced cells seems to be related to changes in the shape of the AP waveform. These currents sustain the faster spiking in Syn-deficient cells by increasing the after hyperpolarization and limiting the Na(+) and Ca(2+) channel inactivation during repetitive firing. This in turn speeds up the depolarization phase by reaching the AP threshold faster. Our results provide evidence that Syn silencing increases intrinsic cell excitability associated with increased Ca(2+) and Ca(2+)-dependent BK currents in the absence of excitatory or inhibitory inputs.
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23
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Pitcher MR, Herrera JA, Buffington SA, Kochukov MY, Merritt JK, Fisher AR, Schanen NC, Costa-Mattioli M, Neul JL. Rett syndrome like phenotypes in the R255X Mecp2 mutant mouse are rescued by MECP2 transgene. Hum Mol Genet 2015; 24:2662-72. [PMID: 25634563 DOI: 10.1093/hmg/ddv030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/26/2015] [Indexed: 01/26/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that is usually caused by mutations in Methyl-CpG-binding Protein 2 (MECP2). Four of the eight common disease causing mutations in MECP2 are nonsense mutations and are responsible for over 35% of all cases of RTT. A strategy to overcome disease-causing nonsense mutations is treatment with nonsense mutation suppressing drugs that allow expression of full-length proteins from mutated genes with premature in-frame stop codons. To determine if this strategy is useful in RTT, we characterized a new mouse model containing a knock-in nonsense mutation (p.R255X) in the Mecp2 locus (Mecp2(R255X)). To determine whether the truncated gene product acts as a dominant negative allele and if RTT-like phenotypes could be rescued by expression of wild-type protein, we genetically introduced an extra copy of MECP2 via an MECP2 transgene. The addition of MECP2 transgene to Mecp2(R255X) mice abolished the phenotypic abnormalities and resulted in near complete rescue. Expression of MECP2 transgene Mecp2(R255X) allele also rescued mTORC1 signaling abnormalities discovered in mice with loss of function and overexpression of Mecp2. Finally, we treated Mecp2(R255X) embryonic fibroblasts with the nonsense mutation suppressing drug gentamicin and we were able to induce expression of full-length MeCP2 from the mutant p.R255X allele. These data provide proof of concept that the p.R255X mutation of MECP2 is amenable to the nonsense suppression therapeutic strategy and provide guidelines for the extent of rescue that can be expected by re-expressing MeCP2 protein.
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Affiliation(s)
- Meagan R Pitcher
- Interdepartmental Program in Translational Biology and Molecular Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - José A Herrera
- Interdepartmental Program in Translational Biology and Molecular Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Mikhail Y Kochukov
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Jonathan K Merritt
- Interdepartmental Program in Translational Biology and Molecular Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Amanda R Fisher
- Department of Biological Sciences, University of Delaware, Newark, DE, USA and
| | | | | | - Jeffrey L Neul
- Interdepartmental Program in Translational Biology and Molecular Medicine, Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX, USA, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA,
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24
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Srivastava AK, Schwartz CE. Intellectual disability and autism spectrum disorders: causal genes and molecular mechanisms. Neurosci Biobehav Rev 2014; 46 Pt 2:161-74. [PMID: 24709068 DOI: 10.1016/j.neubiorev.2014.02.015] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/30/2014] [Accepted: 02/12/2014] [Indexed: 12/19/2022]
Abstract
Intellectual disability (ID) and autism spectrum disorder (ASD) are the most common developmental disorders present in humans. Combined, they affect between 3 and 5% of the population. Additionally, they can be found together in the same individual thereby complicating treatment. The causative factors (genes, epigenetic and environmental) are quite varied and likely interact so as to further complicate the assessment of an individual patient. Nonetheless, much valuable information has been gained by identifying candidate genes for ID or ASD. Understanding the etiology of either ID or ASD is of utmost importance for families. It allows a determination of the risk of recurrence, the possibility of other comorbidity medical problems, the molecular and cellular nature of the pathobiology and hopefully potential therapeutic approaches.
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Affiliation(s)
- Anand K Srivastava
- J.C. Self Research Institute, Greenwood Genetic Center, Greenwood, SC, USA
| | - Charles E Schwartz
- J.C. Self Research Institute, Greenwood Genetic Center, Greenwood, SC, USA.
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25
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Giovedí S, Corradi A, Fassio A, Benfenati F. Involvement of synaptic genes in the pathogenesis of autism spectrum disorders: the case of synapsins. Front Pediatr 2014; 2:94. [PMID: 25237665 PMCID: PMC4154395 DOI: 10.3389/fped.2014.00094] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/21/2014] [Indexed: 12/03/2022] Open
Abstract
Autism spectrum disorders (ASDs) are heterogeneous neurodevelopmental disorders characterized by deficits in social interaction and social communication, restricted interests, and repetitive behaviors. Many synaptic protein genes are linked to the pathogenesis of ASDs, making them prototypical synaptopathies. An array of mutations in the synapsin (Syn) genes in humans has been recently associated with ASD and epilepsy, diseases that display a frequent comorbidity. Syns are pre-synaptic proteins regulating synaptic vesicle traffic, neurotransmitter release, and short-term synaptic plasticity. In doing so, Syn isoforms control the tone of activity of neural circuits and the balance between excitation and inhibition. As ASD pathogenesis is believed to result from dysfunctions in the balance between excitatory and inhibitory transmissions in neocortical areas, Syns are novel ASD candidate genes. Accordingly, deletion of single Syn genes in mice, in addition to epilepsy, causes core symptoms of ASD by affecting social behavior, social communication, and repetitive behaviors. Thus, Syn knockout mice represent a good experimental model to define synaptic alterations involved in the pathogenesis of ASD and epilepsy.
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Affiliation(s)
- Silvia Giovedí
- Department of Experimental Medicine, University of Genova , Genova , Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova , Genova , Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genova , Genova , Italy ; Department of Neuroscience and Brain Technologies, Fondazione Istituto Italiano di Tecnologia , Genova , Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, University of Genova , Genova , Italy ; Department of Neuroscience and Brain Technologies, Fondazione Istituto Italiano di Tecnologia , Genova , Italy
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26
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Corradi A, Fadda M, Piton A, Patry L, Marte A, Rossi P, Cadieux-Dion M, Gauthier J, Lapointe L, Mottron L, Valtorta F, Rouleau GA, Fassio A, Benfenati F, Cossette P. SYN2 is an autism predisposing gene: loss-of-function mutations alter synaptic vesicle cycling and axon outgrowth. Hum Mol Genet 2013; 23:90-103. [PMID: 23956174 PMCID: PMC3857945 DOI: 10.1093/hmg/ddt401] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
An increasing number of genes predisposing to autism spectrum disorders (ASDs) has been identified, many of which are implicated in synaptic function. This 'synaptic autism pathway' notably includes disruption of SYN1 that is associated with epilepsy, autism and abnormal behavior in both human and mice models. Synapsins constitute a multigene family of neuron-specific phosphoproteins (SYN1-3) present in the majority of synapses where they are implicated in the regulation of neurotransmitter release and synaptogenesis. Synapsins I and II, the major Syn isoforms in the adult brain, display partially overlapping functions and defects in both isoforms are associated with epilepsy and autistic-like behavior in mice. In this study, we show that nonsense (A94fs199X) and missense (Y236S and G464R) mutations in SYN2 are associated with ASD in humans. The phenotype is apparent in males. Female carriers of SYN2 mutations are unaffected, suggesting that SYN2 is another example of autosomal sex-limited expression in ASD. When expressed in SYN2 knockout neurons, wild-type human Syn II fully rescues the SYN2 knockout phenotype, whereas the nonsense mutant is not expressed and the missense mutants are virtually unable to modify the SYN2 knockout phenotype. These results identify for the first time SYN2 as a novel predisposing gene for ASD and strengthen the hypothesis that a disturbance of synaptic homeostasis underlies ASD.
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Affiliation(s)
- Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova 16132, Italy
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