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Bertocchi I, Cambiaghi M, Hasan MT. Advances toward precision therapeutics for developmental and epileptic encephalopathies. Front Neurosci 2023; 17:1140679. [PMID: 37090807 PMCID: PMC10115946 DOI: 10.3389/fnins.2023.1140679] [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: 01/09/2023] [Accepted: 03/16/2023] [Indexed: 04/25/2023] Open
Abstract
Developmental and epileptic encephalopathies are childhood syndromes of severe epilepsy associated with cognitive and behavioral disorders. Of note, epileptic seizures represent only a part, although substantial, of the clinical spectrum. Whether the epileptiform activity per se accounts for developmental and intellectual disabilities is still unclear. In a few cases, seizures can be alleviated by antiseizure medication (ASM). However, the major comorbid features associated remain unsolved, including psychiatric disorders such as autism-like and attention deficit hyperactivity disorder-like behavior. Not surprisingly, the number of genes known to be involved is continuously growing, and genetically engineered rodent models are valuable tools for investigating the impact of gene mutations on local and distributed brain circuits. Despite the inconsistencies and problems arising in the generation and validation of the different preclinical models, those are unique and precious tools to identify new molecular targets, and essential to provide prospects for effective therapeutics.
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Affiliation(s)
- Ilaria Bertocchi
- Laboratory of Neuropsychopharmacology, Department of Neuroscience Rita Levi Montalcini, Institute of Neuroscience Cavalieri Ottolenghi (NICO), University of Turin, Torino, Italy
- Department of Neuroscience Rita Levi Montalcini, Neuroscience Institute of Turin (NIT), Torino, Italy
- *Correspondence: Ilaria Bertocchi,
| | - Marco Cambiaghi
- Department Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mazahir T. Hasan
- Laboratory of Brain Circuits Therapeutics, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque – Basque Foundation for Science, Bilbao, Spain
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2
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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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Dysfunction of the serotonergic system in the brain of synapsin triple knockout mice is associated with behavioral abnormalities resembling synapsin-related human pathologies. Prog Neuropsychopharmacol Biol Psychiatry 2021; 105:110135. [PMID: 33058959 DOI: 10.1016/j.pnpbp.2020.110135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/31/2020] [Accepted: 10/06/2020] [Indexed: 11/23/2022]
Abstract
Synapsins (Syns) are a family of phosphoproteins associated with synaptic vesicles (SVs). Their main function is to regulate neurotransmitter release by maintaining a reserve pool of SVs at the presynaptic terminal. Previous studies reported that the deletion of one or more Syn genes in mice results in an epileptic phenotype and autism-related behavioral abnormalities. Here we aimed at characterizing the behavioral phenotype and neurobiological correlates of the deletion of Syns in a Syn triple knockout (TKO) mouse model. Wild type (WT) and TKO mice were tested in the open field, novelty suppressed feeding, light-dark box, forced swim, tail suspension and three-chamber sociability tests. Using in vivo electrophysiology, we recorded the spontaneous activity of dorsal raphe nucleus (DRN) serotonin (5-HT) and ventral tegmental area (VTA) dopamine (DA) neurons. Levels of 5-HT and DA in the frontal cortex and hippocampus of WT and TKO mice were also assessed using a High-Performance Liquid Chromatography. TKO mice displayed hyperactivity and impaired social and anxiety-like behavior. Behavioral dysfunctions were accompanied by reduced firing activity of DRN 5-HT, but not VTA DA, neurons. TKO mice also showed increased responsiveness of DRN 5-HT-1A autoreceptors, measured as a reduced dose of the 5-HT-1A agonist 8-OH-DPAT necessary to inhibit DRN 5-HT firing activity by 50%. Finally, hippocampal 5-HT levels were lower in TKO than in WT mice. Overall, Syns deletion in mice leads to a reduction in DRN 5-HT firing activity and hippocampal 5-HT levels along with behavioral alterations reminiscent of human neuropsychiatric conditions associated with Syn dysfunction.
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4
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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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5
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Barbieri R, Contestabile A, Ciardo MG, Forte N, Marte A, Baldelli P, Benfenati F, Onofri F. Synapsin I and Synapsin II regulate neurogenesis in the dentate gyrus of adult mice. Oncotarget 2018; 9:18760-18774. [PMID: 29721159 PMCID: PMC5922353 DOI: 10.18632/oncotarget.24655] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 02/25/2018] [Indexed: 01/23/2023] Open
Abstract
Adult neurogenesis is emerging as an important player in brain functions and homeostasis, while impaired or altered adult neurogenesis has been associated with a number of neuropsychiatric diseases, such as depression and epilepsy. Here we investigated the possibility that synapsins (Syns) I and II, beyond their known functions in developing and mature neurons, also play a role in adult neurogenesis. We performed a systematic evaluation of the distinct stages of neurogenesis in the hippocampal dentate gyrus of Syn I and Syn II knockout (KO) mice, before (2-months-old) and after (6-months-old) the appearance of the epileptic phenotype. We found that Syns I and II play an important role in the regulation of adult neurogenesis. In juvenile mice, Syn II deletion was associated with a specific decrease in the proliferation of neuronal progenitors, whereas Syn I deletion impaired the survival of newborn neurons. These defects were reverted after the appearance of the epileptic phenotype, with Syn I KO and Syn II KO mice exhibiting significant increases in survival and proliferation, respectively. Interestingly, long-term potentiation dependent on newborn neurons was present in both juvenile Syn mutants while, at later ages, it was only preserved in Syn II KO mice that also displayed an increased expression of brain-derived neurotrophic factor. This study suggests that Syns I and II play a role in adult neurogenesis and the defects in neurogenesis associated with Syn deletion may contribute to the alterations of cognitive functions observed in Syn-deficient mice.
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Affiliation(s)
- Raffaella Barbieri
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Andrea Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163, Genova, Italy
| | - Maria Grazia Ciardo
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Nicola Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, 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
| | - Franco Onofri
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
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6
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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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7
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Heise C, Taha E, Murru L, Ponzoni L, Cattaneo A, Guarnieri FC, Montani C, Mossa A, Vezzoli E, Ippolito G, Zapata J, Barrera I, Ryazanov AG, Cook J, Poe M, Stephen MR, Kopanitsa M, Benfante R, Rusconi F, Braida D, Francolini M, Proud CG, Valtorta F, Passafaro M, Sala M, Bachi A, Verpelli C, Rosenblum K, Sala C. eEF2K/eEF2 Pathway Controls the Excitation/Inhibition Balance and Susceptibility to Epileptic Seizures. Cereb Cortex 2017; 27:2226-2248. [PMID: 27005990 PMCID: PMC5963824 DOI: 10.1093/cercor/bhw075] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alterations in the balance of inhibitory and excitatory synaptic transmission have been implicated in the pathogenesis of neurological disorders such as epilepsy. Eukaryotic elongation factor 2 kinase (eEF2K) is a highly regulated, ubiquitous kinase involved in the control of protein translation. Here, we show that eEF2K activity negatively regulates GABAergic synaptic transmission. Indeed, loss of eEF2K increases GABAergic synaptic transmission by upregulating the presynaptic protein Synapsin 2b and α5-containing GABAA receptors and thus interferes with the excitation/inhibition balance. This cellular phenotype is accompanied by an increased resistance to epilepsy and an impairment of only a specific hippocampal-dependent fear conditioning. From a clinical perspective, our results identify eEF2K as a potential novel target for antiepileptic drugs, since pharmacological and genetic inhibition of eEF2K can revert the epileptic phenotype in a mouse model of human epilepsy.
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Affiliation(s)
| | - Elham Taha
- Sagol Department of Neurobiology and
- Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Luca Murru
- CNR Neuroscience Institute, Milan, Italy
| | - Luisa Ponzoni
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | - Fabrizia C. Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | | | | | - Elena Vezzoli
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | | | - Iliana Barrera
- Sagol Department of Neurobiology and
- Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Alexey G. Ryazanov
- The Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - James Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Poe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Rajesh Stephen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Maksym Kopanitsa
- Synome, Babraham Research Campus, Cambridge CB22 3AT, UK
- Charles River Discovery Research Services, 70210 Kuopio, Finland
| | - Roberta Benfante
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Francesco Rusconi
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Daniela Braida
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Maura Francolini
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Christopher G. Proud
- University of Southampton, Centre for Biological Sciences, Southampton SO17 1BJ, UK
- South Australian Health and Medical Research Institute and University of Adelaide, Adelaide, Australia
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Maria Passafaro
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Mariaelvina Sala
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy
| | - Chiara Verpelli
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Kobi Rosenblum
- Sagol Department of Neurobiology and
- Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Carlo Sala
- CNR Neuroscience Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
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8
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Pennucci R, Talpo F, Astro V, Montinaro V, Morè L, Cursi M, Castoldi V, Chiaretti S, Bianchi V, Marenna S, Cambiaghi M, Tonoli D, Leocani L, Biella G, D'Adamo P, de Curtis I. Loss of Either Rac1 or Rac3 GTPase Differentially Affects the Behavior of Mutant Mice and the Development of Functional GABAergic Networks. Cereb Cortex 2015; 26:873-890. [PMID: 26582364 PMCID: PMC4712809 DOI: 10.1093/cercor/bhv274] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Rac GTPases regulate the development of cortical/hippocampal GABAergic interneurons by affecting the early development and migration of GABAergic precursors. We have addressed the function of Rac1 and Rac3 proteins during the late maturation of hippocampal interneurons. We observed specific phenotypic differences between conditional Rac1 and full Rac3 knockout mice. Rac1 deletion caused greater generalized hyperactivity and cognitive impairment compared with Rac3 deletion. This phenotype matched with a more evident functional impairment of the inhibitory circuits in Rac1 mutants, showing higher excitability and reduced spontaneous inhibitory currents in the CA hippocampal pyramidal neurons. Morphological analysis confirmed a differential modification of the inhibitory circuits: deletion of either Rac caused a similar reduction of parvalbumin-positive inhibitory terminals in the pyramidal layer. Intriguingly, cannabinoid receptor-1-positive terminals were strongly increased only in the CA1 of Rac1-depleted mice. This increase may underlie the stronger electrophysiological defects in this mutant. Accordingly, incubation with an antagonist for cannabinoid receptors partially rescued the reduction of spontaneous inhibitory currents in the pyramidal cells of Rac1 mutants. Our results show that Rac1 and Rac3 have independent roles in the formation of GABAergic circuits, as highlighted by the differential effects of their deletion on the late maturation of specific populations of interneurons.
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Affiliation(s)
| | - Francesca Talpo
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Italy
| | | | | | - Lorenzo Morè
- Molecular Genetics of Mental Retardation Unit, Division of Neuroscience, IRCSS San Raffaele Scientific Institute, Milano, Italy
| | - Marco Cursi
- Experimental Neurophysiology Unit, INSPE-Institute of Experimental Neurology, Division of Neuroscience, IRCSS San Raffaele Scientific Institute and San Raffaele University, Milano 20132, Italy
| | - Valerio Castoldi
- Experimental Neurophysiology Unit, INSPE-Institute of Experimental Neurology, Division of Neuroscience, IRCSS San Raffaele Scientific Institute and San Raffaele University, Milano 20132, Italy
| | | | - Veronica Bianchi
- Molecular Genetics of Mental Retardation Unit, Division of Neuroscience, IRCSS San Raffaele Scientific Institute, Milano, Italy
| | - Silvia Marenna
- Experimental Neurophysiology Unit, INSPE-Institute of Experimental Neurology, Division of Neuroscience, IRCSS San Raffaele Scientific Institute and San Raffaele University, Milano 20132, Italy
| | - Marco Cambiaghi
- Experimental Neurophysiology Unit, INSPE-Institute of Experimental Neurology, Division of Neuroscience, IRCSS San Raffaele Scientific Institute and San Raffaele University, Milano 20132, Italy
| | | | - Letizia Leocani
- Experimental Neurophysiology Unit, INSPE-Institute of Experimental Neurology, Division of Neuroscience, IRCSS San Raffaele Scientific Institute and San Raffaele University, Milano 20132, Italy
| | - Gerardo Biella
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Italy
| | - Patrizia D'Adamo
- Molecular Genetics of Mental Retardation Unit, Division of Neuroscience, IRCSS San Raffaele Scientific Institute, Milano, Italy
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9
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Cambiaghi M, Magri L, Cursi M. Importance of EEG in validating the chronic effects of drugs: suggestions from animal models of epilepsy treated with rapamycin. Seizure 2015; 27:30-9. [PMID: 25891924 DOI: 10.1016/j.seizure.2015.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The development of new drugs for the treatment of epilepsy is a major challenge for modern neurology and its first steps demand basic research. Preclinical studies on animal models of epilepsy are mainly based on the analysis of brain electrical activity to detect seizures, when they are not just limited to behavioral tests like the Racine scale. METHODS In the present review, we discuss the importance of using time-locked video and EEG recordings (Video-EEG) coupled with behavioral tests as tools to monitor and analyze the effects of anti-epileptic drugs in pre-clinical research. Particularly, we focus on the utility of a multimodal approach based on EEG/behavioral analysis to study the beneficial effects of chronic rapamycin treatment as a potential anti-epileptogenic therapy for a broad spectrum of epilepsy, including both genetic (as in tuberous sclerosis complex) and acquired diseases. RESULTS Changes and synchronization of neuronal activity of different areas have been correlated with specific behavior in both physiological and pathological conditions. In the epileptic brain, during a seizure there is an abnormal activation of many cells all at once, altering different networks. CONCLUSION A multimodal approach based on video, EEG analysis and behavioral tests would be the best option in preclinical studies of epilepsy.
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Affiliation(s)
- Marco Cambiaghi
- Università degli Studi di Torino, Department of Neuroscience, Turin, Italy.
| | - Laura Magri
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
| | - Marco Cursi
- Clinical Neurophysiology Unit, Department of Neurology, Scientific Institute San Raffaele, Milan, Italy
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10
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Garbarino G, Costa S, Pestarino M, Candiani S. Differential expression of synapsin genes during early zebrafish development. Neuroscience 2014; 280:351-67. [DOI: 10.1016/j.neuroscience.2014.09.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 11/27/2022]
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11
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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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12
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Giannandrea M, Guarnieri FC, Gehring NH, Monzani E, Benfenati F, Kulozik AE, Valtorta F. Nonsense-mediated mRNA decay and loss-of-function of the protein underlie the X-linked epilepsy associated with the W356× mutation in synapsin I. PLoS One 2013; 8:e67724. [PMID: 23818987 PMCID: PMC3688603 DOI: 10.1371/journal.pone.0067724] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/21/2013] [Indexed: 11/22/2022] Open
Abstract
Synapsins are a family of neuronal phosphoproteins associated with the cytosolic surface of synaptic vesicles. Experimental evidence suggests a role for synapsins in synaptic vesicle clustering and recycling at the presynaptic terminal, as well as in neuronal development and synaptogenesis. Synapsin knock-out (Syn1(-/-) ) mice display an epileptic phenotype and mutations in the SYN1 gene have been identified in individuals affected by epilepsy and/or autism spectrum disorder. We investigated the impact of the c.1067G>A nonsense transition, the first mutation described in a family affected by X-linked syndromic epilepsy, on the expression and functional properties of the synapsin I protein. We found that the presence of a premature termination codon in the human SYN1 transcript renders it susceptible to nonsense-mediated mRNA decay (NMD). Given that the NMD efficiency is highly variable among individuals and cell types, we investigated also the effects of expression of the mutant protein and found that it is expressed at lower levels compared to wild-type synapsin I, forms perinuclear aggregates and is unable to reach presynaptic terminals in mature hippocampal neurons grown in culture. Taken together, these data indicate that in patients carrying the W356× mutation the function of synapsin I is markedly impaired, due to both the strongly decreased translation and the altered function of the NMD-escaped protein, and support the value of Syn1(-/-) mice as an experimental model mimicking the human pathology.
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MESH Headings
- Animals
- Blotting, Northern
- Cells, Cultured
- Codon, Nonsense
- Epilepsy/genetics
- Epilepsy/metabolism
- Female
- Gene Expression
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/metabolism
- HeLa Cells
- Hippocampus/cytology
- Hippocampus/metabolism
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Fluorescence
- Microtubule-Associated Proteins/metabolism
- Neurons/metabolism
- Nonsense Mediated mRNA Decay
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Synapsins/genetics
- Synapsins/metabolism
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Affiliation(s)
- Maila Giannandrea
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Fabrizia C. Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | | | - Elena Monzani
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Fabio Benfenati
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genoa, Italy
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Andreas E. Kulozik
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg Medical Center and Molecular Medicine Partnership Unit, EMBL and University of Heidelberg, Heidelberg, Germany
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
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13
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Greco B, Managò F, Tucci V, Kao HT, Valtorta F, Benfenati F. Autism-related behavioral abnormalities in synapsin knockout mice. Behav Brain Res 2012; 251:65-74. [PMID: 23280234 PMCID: PMC3730181 DOI: 10.1016/j.bbr.2012.12.015] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 11/19/2012] [Accepted: 12/10/2012] [Indexed: 02/08/2023]
Abstract
Several synaptic genes predisposing to autism-spectrum disorder (ASD) have been identified. Nonsense and missense mutations in the SYN1 gene encoding for Synapsin I have been identified in families segregating for idiopathic epilepsy and ASD and genetic mapping analyses have identified variations in the SYN2 gene as significantly contributing to epilepsy predisposition. Synapsins (Syn I/II/III) are a multigene family of synaptic vesicle-associated phosphoproteins playing multiple roles in synaptic development, transmission and plasticity. Lack of SynI and/or SynII triggers a strong epileptic phenotype in mice associated with mild cognitive impairments that are also present in the non-epileptic SynIII(-/-) mice. SynII(-/-) and SynIII(-/-) mice also display schizophrenia-like traits, suggesting that Syns could be involved in the regulation of social behavior. Here, we studied social interaction and novelty, social recognition and social dominance, social transmission of food preference and social memory in groups of male SynI(-/-), SynII(-/-) and SynIII(-/-) mice before and after the appearance of the epileptic phenotype and compared their performances with control mice. We found that deletion of Syn isoforms widely impairs social behaviors and repetitive behaviors, resulting in ASD-related phenotypes. SynI or SynIII deletion altered social behavior, whereas SynII deletion extensively impaired various aspects of social behavior and memory, altered exploration of a novel environment and increased self-grooming. Social impairments of SynI(-/-) and SynII(-/-) mice were evident also before the onset of seizures. The results demonstrate an involvement of Syns in generation of the behavioral traits of ASD and identify Syn knockout mice as a useful experimental model of ASD and epilepsy.
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Affiliation(s)
- Barbara Greco
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy
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