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Helm M, Bohnsack MT, Carell T, Dalpke A, Entian KD, Ehrenhofer-Murray A, Ficner R, Hammann C, Höbartner C, Jäschke A, Jeltsch A, Kaiser S, Klassen R, Leidel SA, Marx A, Mörl M, Meier JC, Meister G, Rentmeister A, Rodnina M, Roignant JY, Schaffrath R, Stadler P, Stafforst T. Experience with German Research Consortia in the Field of Chemical Biology of Native Nucleic Acid Modifications. ACS Chem Biol 2023; 18:2441-2449. [PMID: 37962075 DOI: 10.1021/acschembio.3c00586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The chemical biology of native nucleic acid modifications has seen an intense upswing, first concerning DNA modifications in the field of epigenetics and then concerning RNA modifications in a field that was correspondingly rebaptized epitranscriptomics by analogy. The German Research Foundation (DFG) has funded several consortia with a scientific focus in these fields, strengthening the traditionally well-developed nucleic acid chemistry community and inciting it to team up with colleagues from the life sciences and data science to tackle interdisciplinary challenges. This Perspective focuses on the genesis, scientific outcome, and downstream impact of the DFG priority program SPP1784 and offers insight into how it fecundated further consortia in the field. Pertinent research was funded from mid-2015 to 2022, including an extension related to the coronavirus pandemic. Despite being a detriment to research activity in general, the pandemic has resulted in tremendously boosted interest in the field of RNA and RNA modifications as a consequence of their widespread and successful use in vaccination campaigns against SARS-CoV-2. Funded principal investigators published over 250 pertinent papers with a very substantial impact on the field. The program also helped to redirect numerous laboratories toward this dynamic field. Finally, SPP1784 spawned initiatives for several funded consortia that continue to drive the fields of nucleic acid modification.
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Affiliation(s)
- Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Thomas Carell
- Department of Chemistry, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Alexander Dalpke
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Karl-Dieter Entian
- Institute for Molecular Biosciences, Goethe-University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | | | - Ralf Ficner
- Institute for Microbiology and Genetics, Georg-August University Göttingen, 37077 Göttingen, Germany
| | - Christian Hammann
- Department of Medicine, HMU Health and Medical University, 14471 Potsdam, Germany
| | - Claudia Höbartner
- Institute for Organic Chemistry, Julius-Maximilians-University of Würzburg, 97074 Würzburg, Germany
| | - Andres Jäschke
- Institute for Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University Heidelberg, 69120 Heidelberg, Germany
| | - Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Stefanie Kaiser
- Institute for Pharmaceutical Chemistry, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - Roland Klassen
- Institute for Biology - Microbiology, University of Kassel, 34132 Kassel, Germany
| | - Sebastian A Leidel
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Andreas Marx
- Department of Chemistry - Organic/Cellular Chemistry, University of Constance, 78457 Constance, Germany
| | - Mario Mörl
- Institute of Biochemistry, University of Leipzig, 04103 Leipzig, Germany
| | - Jochen C Meier
- Department of Cell Physiology, Technical University of Braunschweig, 38106 Brunswick, Germany
| | - Gunter Meister
- Institute of Biochemistry, Genetics and Microbiology - Biochemistry I, University of Regensburg, 93053 Regensburg, Germany
| | - Andrea Rentmeister
- Institute for Biochemistry, Westphalian Wilhelms University Münster, 48149 Münster, Germany
| | - Marina Rodnina
- Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
| | - Jean-Yves Roignant
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Raffael Schaffrath
- Institute for Biology - Microbiology, University of Kassel, 34132 Kassel, Germany
| | - Peter Stadler
- Institute for Computer Science - Bioinformatics, University of Leipzig, 04107 Leipzig, Germany
| | - Thorsten Stafforst
- Interfaculty Institute for Biochemistry, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
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2
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Fricke S, Harnau M, Hetsch F, Liu H, Leonhard J, Eylmann A, Knauff P, Sun H, Semtner M, Meier JC. Cesium activates the neurotransmitter receptor for glycine. Front Mol Neurosci 2023; 16:1018530. [PMID: 37284465 PMCID: PMC10239821 DOI: 10.3389/fnmol.2023.1018530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 05/02/2023] [Indexed: 06/08/2023] Open
Abstract
The monovalent cations sodium and potassium are crucial for the proper functioning of excitable cells, but, in addition, other monovalent alkali metal ions such as cesium and lithium can also affect neuronal physiology. For instance, there have been recent reports of adverse effects resulting from self-administered high concentrations of cesium in disease conditions, prompting the Food and Drug Administration (FDA) to issue an alert concerning cesium chloride. As we recently found that the monovalent cation NH4+ activates glycine receptors (GlyRs), we investigated the effects of alkali metal ions on the function of the GlyR, which belongs to one of the most widely distributed neurotransmitter receptors in the peripheral and central nervous systems. Whole-cell voltage clamp electrophysiology was performed with HEK293T cells transiently expressing different splice and RNA-edited variants of GlyR α2 and α3 homopentameric channels. By examining the influence of various milli- and sub-millimolar concentrations of lithium, sodium, potassium, and cesium on these GlyRs in comparison to its natural ligand glycine (0.1 mM), we could show that cesium activates GlyRs in a concentration- and post-transcriptional-dependent way. Additionally, we conducted atomistic molecular dynamic simulations on GlyR α3 embedded in a membrane bilayer with potassium and cesium, respectively. The simulations revealed slightly different GlyR-ion binding profiles for potassium and cesium, identifying interactions near the glycine binding pocket (potassium and cesium) and close to the RNA-edited site (cesium) in the extracellular GlyR domain. Together, these findings show that cesium acts as an agonist of GlyRs.
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Affiliation(s)
- Steffen Fricke
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Magnus Harnau
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Florian Hetsch
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Haoran Liu
- Structural Chemistry and Computational Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
- Institute of Chemistry, Technical University of Berlin, Berlin, Germany
| | - Julia Leonhard
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Anna Eylmann
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Pina Knauff
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Han Sun
- Structural Chemistry and Computational Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
- Institute of Chemistry, Technical University of Berlin, Berlin, Germany
| | - Marcus Semtner
- Psychoneuroimmunology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jochen C. Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
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3
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Pose-Méndez S, Schramm P, Winter B, Meier JC, Ampatzis K, Köster RW. Lifelong regeneration of cerebellar Purkinje cells after induced cell ablation in zebrafish. eLife 2023; 12:79672. [PMID: 37042514 PMCID: PMC10147380 DOI: 10.7554/elife.79672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 04/11/2023] [Indexed: 04/13/2023] Open
Abstract
Zebrafish have an impressive capacity to regenerate neurons in the central nervous system. However, regeneration of the principal neuron of the evolutionary conserved cerebellum, the Purkinje cell (PC), is believed to be limited to developmental stages based on invasive lesions. In contrast, non-invasive cell type specific ablation by induced apoptosis closely represents a process of neurodegeneration. We demonstrate that the ablated larval PC population entirely recovers in number, quickly reestablishes electrophysiological properties, and properly integrates into circuits to regulate cerebellum-controlled behavior. PC progenitors are present in larvae and adults, and PC ablation in adult cerebelli results in an impressive PC regeneration of different PC subtypes able to restore behavioral impairments. Interestingly, caudal PCs are more resistant to ablation and regenerate more efficiently, suggesting a rostro-caudal pattern of de- and regeneration properties. These findings demonstrate that the zebrafish cerebellum is able to regenerate functional PCs during all stages of the animal's life.
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Affiliation(s)
- Sol Pose-Méndez
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Paul Schramm
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Barbara Winter
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Jochen C Meier
- Cell Physiology, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Reinhard W Köster
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
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4
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Dorigo A, Valishetti K, Hetsch F, Matsui H, Meier JC, Namikawa K, Köster RW. Functional regionalization of the differentiating cerebellar Purkinje cell population occurs in an activity-dependent manner. Front Mol Neurosci 2023; 16:1166900. [PMID: 37181649 PMCID: PMC10174242 DOI: 10.3389/fnmol.2023.1166900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/11/2023] [Indexed: 05/16/2023] Open
Abstract
Introduction The cerebellum is organized into functional regions each dedicated to process different motor or sensory inputs for controlling different locomotor behaviors. This functional regionalization is prominent in the evolutionary conserved single-cell layered Purkinje cell (PC) population. Fragmented gene expression domains suggest a genetic organization of PC layer regionalization during cerebellum development. However, the establishment of such functionally specific domains during PC differentiation remained elusive. Methods and results We show the progressive emergence of functional regionalization of PCs from broad responses to spatially restricted regions in zebrafish by means of in vivo Ca2+-imaging during stereotypic locomotive behavior. Moreover, we reveal that formation of new dendritic spines during cerebellar development using in vivo imaging parallels the time course of functional domain development. Pharmacological as well as cell-type specific optogenetic inhibition of PC neuronal activity results in reduced PC dendritic spine density and an altered stagnant pattern of functional domain formation in the PC layer. Discussion Hence, our study suggests that functional regionalization of the PC layer is driven by physiological activity of maturing PCs themselves.
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Affiliation(s)
- Alessandro Dorigo
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Komali Valishetti
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Florian Hetsch
- Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
- Institute of Pathophysiology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Hideaki Matsui
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
| | - Jochen C. Meier
- Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Kazuhiko Namikawa
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Kazuhiko Namikawa,
| | - Reinhard W. Köster
- Cellular and Molecular Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany
- Reinhard W. Köster,
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5
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Ainge JA, Chisari M, Cohen A, Mennerick SJ, Topolnik L, Meier JC. Editorial: Spring Hippocampal Research Conference and Beyond. Front Mol Neurosci 2021; 14:773308. [PMID: 34712119 PMCID: PMC8546257 DOI: 10.3389/fnmol.2021.773308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 09/20/2021] [Indexed: 11/26/2022] Open
Affiliation(s)
- James A Ainge
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom
| | - Mariangela Chisari
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Akiva Cohen
- University of Pennsylvania and Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Steven J Mennerick
- Department of Psychiatry, Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Lisa Topolnik
- Department of Biochemistry, Microbiology and Bio-Informatics, Laval University, Québec City, QC, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec City, QC, Canada
| | - Jochen C Meier
- Division Cell Physiology, Technical University Braunschweig, Zoological Institute, Braunschweig, Germany
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6
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Macha A, Liebsch F, Fricke S, Hetsch F, Neuser F, Johannes L, Kress V, Djémié T, Santamaria-Araujo JA, Vilain C, Aeby A, Van Bogaert P, Dejanovic B, Weckhuysen S, Meier JC, Schwarz G. Bi-allelic gephyrin variants impair GABAergic inhibition in a patient with epileptic encephalopathy. Hum Mol Genet 2021; 31:901-913. [PMID: 34617111 DOI: 10.1093/hmg/ddab298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 11/12/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition is linked to epilepsy. Gephyrin (Geph) is the principal scaffolding protein at inhibitory synapses and is essential for postsynaptic clustering of glycine (GlyRs) and GABA type A receptors (GABAARs). Consequently, gephyrin is crucial for maintaining the relationship between excitation and inhibition in normal brain function and mutations in the gephyrin gene (GPHN) are associated with neurodevelopmental disorders and epilepsy. We identified bi-allelic variants in the GPHN gene, namely the missense mutation c.1264G > A and splice acceptor variant c.1315-2A > G, in a patient with developmental and epileptic encephalopathy (DEE). We demonstrate that the splice acceptor variant leads to nonsense-mediated mRNA decay (NMD). Furthermore, the missense variant (D422N) alters gephyrin structure, as examined by analytical size exclusion chromatography and CD-spectroscopy, thus leading to reduced receptor clustering and sensitivity towards calpain-mediated cleavage. Additionally, both alterations contribute to an observed reduction of inhibitory signal transmission in neurons, which likely contributes to the pathological encephalopathy.
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Affiliation(s)
- Arthur Macha
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Filip Liebsch
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Steffen Fricke
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Institute for Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Franziska Neuser
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Lena Johannes
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Vanessa Kress
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Tania Djémié
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium
| | - Jose A Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Catheline Vilain
- Department of Genetics, Hôpital Universitaire des Enfants Reine Fabiola, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Department of Genetics, Hôpital Erasme, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles, Brussels, Belgium
| | - Alec Aeby
- Pediatric Neurology, Queen Fabiola Children Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Patrick Van Bogaert
- Departement of Pediatric Neurology, CHU d'Angers, and Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), Université d'Angers, France
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium.,Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp, Belgium.,Neurology Department, University Hospital Antwerp, Antwerp, Belgium
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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7
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Schramm P, Hetsch F, Meier JC, Köster RW. In vivo Imaging of Fully Active Brain Tissue in Awake Zebrafish Larvae and Juveniles by Skull and Skin Removal. J Vis Exp 2021. [PMID: 33645565 DOI: 10.3791/62166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Understanding the ephemeral changes that occur during brain development and maturation requires detailed high-resolution imaging in space and time at cellular and subcellular resolution. Advances in molecular and imaging technologies have allowed us to gain numerous detailed insights into cellular and molecular mechanisms of brain development in the transparent zebrafish embryo. Recently, processes of refinement of neuronal connectivity that occur at later larval stages several weeks after fertilization, which are for example control of social behavior, decision making or motivation-driven behavior, have moved into focus of research. At these stages, pigmentation of the zebrafish skin interferes with light penetration into brain tissue, and solutions for embryonic stages, e.g., pharmacological inhibition of pigmentation, are not feasible anymore. Therefore, a minimally invasive surgical solution for microscopy access to the brain of awake zebrafish is provided that is derived from electrophysiological approaches. In teleosts, skin and soft skull cartilage can be carefully removed by micro-peeling these layers, exposing underlying neurons and axonal tracts without damage. This allows for recording neuronal morphology, including synaptic structures and their molecular contents, and the observation of physiological changes such as Ca2+ transients or intracellular transport events. In addition, interrogation of these processes by means of pharmacological inhibition or optogenetic manipulation is feasible. This brain exposure approach provides information about structural and physiological changes in neurons as well as the correlation and interdependence of these events in live brain tissue in the range of minutes or hours. The technique is suitable for in vivo brain imaging of zebrafish larvae up to 30 days post fertilization, the latest developmental stage tested so far. It, thus, provides access to such important questions as synaptic refinement and scaling, axonal and dendritic transport, synaptic targeting of cytoskeletal cargo or local activity-dependent expression. Therefore, a broad use for this mounting and imaging approach can be anticipated.
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Affiliation(s)
- Paul Schramm
- Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig
| | - Florian Hetsch
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University
| | - Jochen C Meier
- Cell Physiology, Zoological institute, Technische Universität Braunschweig
| | - Reinhard W Köster
- Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig;
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8
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Knoll A, Kankowski S, Schöllkopf S, Meier JC, Seitz O. Chemo-biological mRNA imaging with single nucleotide specificity. Chem Commun (Camb) 2020; 55:14817-14820. [PMID: 31763632 DOI: 10.1039/c9cc06989e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Unambiguous imaging of C → U edited mRNA calls for a method that distinguishes a locally high concentration of unbound probe or single nucleotide mismatched target from a locally low concentration of matched mRNA target. To address this issue, we combine FIT probes as a "chemical" detection system with the "biological" MS2 technique. Ratio measurements provide a convenient parameter to discriminate the edited from the unedited state of mRNA encoding for GlyR α2 in HEK cells.
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Affiliation(s)
- Andrea Knoll
- Humboldt University Berlin, Department of Chemistry, Brook-Taylor-Str. 2, D-12489 Berlin, Germany.
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9
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Kraus L, Hetsch F, Schneider UC, Radbruch H, Holtkamp M, Meier JC, Fidzinski P. Dimethylethanolamine Decreases Epileptiform Activity in Acute Human Hippocampal Slices in vitro. Front Mol Neurosci 2019; 12:209. [PMID: 31551707 PMCID: PMC6743366 DOI: 10.3389/fnmol.2019.00209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 08/09/2019] [Indexed: 01/13/2023] Open
Abstract
Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy with about 30% of patients developing pharmacoresistance. These patients continue to suffer from seizures despite polytherapy with antiepileptic drugs (AEDs) and have an increased risk for premature death, thus requiring further efforts for the development of new antiepileptic therapies. The molecule dimethylethanolamine (DMEA) has been tested as a potential treatment in various neurological diseases, albeit the functional mechanism of action was never fully understood. In this study, we investigated the effects of DMEA on neuronal activity in single-cell recordings of primary neuronal cultures. DMEA decreased the frequency of spontaneous synaptic events in a concentration-dependent manner with no apparent effect on resting membrane potential (RMP) or action potential (AP) threshold. We further tested whether DMEA can exert antiepileptic effects in human brain tissue ex vivo. We analyzed the effect of DMEA on epileptiform activity in the CA1 region of the resected hippocampus of TLE patients in vitro by recording extracellular field potentials in the pyramidal cell layer. Epileptiform burst activity in resected hippocampal tissue from TLE patients remained stable over several hours and was pharmacologically suppressed by lacosamide, demonstrating the applicability of our platform to test antiepileptic efficacy. Similar to lacosamide, DMEA also suppressed epileptiform activity in the majority of samples, albeit with variable interindividual effects. In conclusion, DMEA might present a new approach for treatment in pharmacoresistant TLE and further studies will be required to identify its exact mechanism of action and the involved molecular targets.
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Affiliation(s)
- Larissa Kraus
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Berlin, Germany
- Berlin Institute of Health (BIH), Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
| | - Florian Hetsch
- Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
| | - Ulf C. Schneider
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurosurgery, Berlin, Germany
| | - Helena Radbruch
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neuropathology, Berlin, Germany
| | - Martin Holtkamp
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Berlin, Germany
- Berlin Institute of Health (BIH), Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
| | - Jochen C. Meier
- Berlin Institute of Health (BIH), Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
- Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
| | - Pawel Fidzinski
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Berlin, Germany
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10
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Kankowski S, Förstera B, Winkelmann A, Knauff P, Wanker EE, You XA, Semtner M, Hetsch F, Meier JC. Corrigendum: A Novel RNA Editing Sensor Tool and a Specific Agonist Determine Neuronal Protein Expression of RNA-Edited Glycine Receptors and Identify a Genomic APOBEC1 Dimorphism as a New Genetic Risk Factor of Epilepsy. Front Mol Neurosci 2019; 12:103. [PMID: 31105523 PMCID: PMC6492049 DOI: 10.3389/fnmol.2019.00103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/04/2019] [Indexed: 11/13/2022] Open
Abstract
[This corrects the article DOI: 10.3389/fnmol.2017.00439.].
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Affiliation(s)
- Svenja Kankowski
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Benjamin Förstera
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig Maximilians University of Munich, Munich, Germany
| | - Aline Winkelmann
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Pina Knauff
- Institute of Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Xintian A You
- Bioinformatics in Medicine, Zuse Institute Berlin, Berlin, Germany
| | - Marcus Semtner
- Cellular Neurosciences, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
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11
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Abstract
Compared to sites in protein-coding sequences many more targets undergoing adenosine to inosine (A-to-I) RNA editing were discovered in non-coding regions of human cerebral transcripts, particularly in genetic transposable elements called retrotransposons. We review here the interaction mechanisms of RNA editing and retrotransposons and their impact on normal function and human neurological diseases. Exemplarily, A-to-I editing of retrotransposons embedded in protein-coding mRNAs can contribute to protein abundance and function via circular RNA formation, alternative splicing, and exonization or silencing of retrotransposons. Interactions leading to disease are not very well understood. We describe human diseases with involvement of the central nervous system including inborn errors of metabolism, neurodevelopmental disorders, neuroinflammatory and neurodegenerative and paroxysmal diseases, in which retrotransposons (Alu and/or L1 elements) appear to be causally involved in genetic rearrangements. Sole binding of single-stranded retrotransposon transcripts by RNA editing enzymes rather than enzymatic deamination may have a homeostatic effect on retrotransposon turnover. We also review evidence in support of the emerging pathophysiological function of A-to-I editing of retrotransposons in inflammation and its implication for different neurological diseases including amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's and Parkinson's disease, and epilepsy.
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Affiliation(s)
- Heinz Krestel
- Department of Neurology, Bern University Hospital and University of Bern, Bern, Switzerland.,Department for BioMedical Research, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technical University Braunschweig, Braunschweig, Germany
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12
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Fang GM, Chamiolo J, Kankowski S, Hövelmann F, Friedrich D, Löwer A, Meier JC, Seitz O. A bright FIT-PNA hybridization probe for the hybridization state specific analysis of a C → U RNA edit via FRET in a binary system. Chem Sci 2018; 9:4794-4800. [PMID: 29910930 PMCID: PMC5982193 DOI: 10.1039/c8sc00457a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/01/2018] [Indexed: 12/24/2022] Open
Abstract
Oligonucleotide probes that show enhanced fluorescence upon nucleic acid hybridization enable the detection and visualization of specific mRNA molecules, in vitro and in cellulo. A challenging problem is the analysis of single nucleotide alterations that occur, for example, when cellular mRNA is subject to C → U editing. Given the length required for uniqueness of the targeted segment, the commonly used probes do not provide the level of sequence specificity needed to discriminate single base mismatched hybridization. Herein we introduce a binary probe system based on fluorescence resonance energy transfer (FRET) that distinguishes three possible states i.e. (i) absence of target, (ii) presence of edited (matched) and (iii) unedited (single base mismatched) target. To address the shortcomings of read-out via FRET, we designed donor probes that avoid bleed through into the acceptor channel and nevertheless provide a high intensity of FRET signaling. We show the combined use of thiazole orange (TO) and an oxazolopyridine analogue (JO), linked as base surrogates in modified PNA FIT-probes that serve as FRET donor for a second, near-infrared (NIR)-labeled strand. In absence of target, donor emission is low and FRET cannot occur in lieu of the lacking co-alignment of probes. Hybridization of the TO/JO-PNA FIT-probe with the (unedited RNA) target leads to high brightness of emission at 540 nm. Co-alignment of the NIR-acceptor strand ensues from recognition of edited RNA inducing emission at 690 nm. We show imaging of mRNA in fixed and live cells and discuss the homogeneous detection and intracellular imaging of a single nucleotide mRNA edit used by nature to post-transcriptionally modify the function of the Glycine Receptor (GlyR).
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Affiliation(s)
- Ge-Min Fang
- Department of Chemistry , Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2 , D-12489 Berlin , Germany . .,Institute of Physical Science and Information Technology , Anhui University , Hefei , Anhui 230601 , China
| | - Jasmine Chamiolo
- Department of Chemistry , Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2 , D-12489 Berlin , Germany .
| | - Svenja Kankowski
- Zoological Institute , Technical University Braunschweig , Spielmannstr. 7 , D-38106 Braunschweig , Germany
| | - Felix Hövelmann
- Department of Chemistry , Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2 , D-12489 Berlin , Germany .
| | - Dhana Friedrich
- Max Delbrück Centrum für Molekulare Medizin , Robert Rössle Straße 10 , 13125 Berlin , Germany.,Technische Universität Darmstadt , Department of Biology , Schnittspahnstraße 13 , 64287 Darmstadt , Germany
| | - Alexander Löwer
- Max Delbrück Centrum für Molekulare Medizin , Robert Rössle Straße 10 , 13125 Berlin , Germany.,Technische Universität Darmstadt , Department of Biology , Schnittspahnstraße 13 , 64287 Darmstadt , Germany
| | - Jochen C Meier
- Zoological Institute , Technical University Braunschweig , Spielmannstr. 7 , D-38106 Braunschweig , Germany
| | - Oliver Seitz
- Department of Chemistry , Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2 , D-12489 Berlin , Germany .
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13
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Le Duigou C, Savary E, Morin-Brureau M, Gomez-Dominguez D, Sobczyk A, Chali F, Milior G, Kraus L, Meier JC, Kullmann DM, Mathon B, de la Prida LM, Dorfmuller G, Pallud J, Eugène E, Clemenceau S, Miles R. Imaging pathological activities of human brain tissue in organotypic culture. J Neurosci Methods 2018; 298:33-44. [PMID: 29427611 DOI: 10.1016/j.jneumeth.2018.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 01/27/2018] [Accepted: 02/02/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Insights into human brain diseases may emerge from tissue obtained after operations on patients. However techniques requiring transduction of transgenes carried by viral vectors cannot be applied to acute human tissue. NEW METHOD We show that organotypic culture techniques can be used to maintain tissue from patients with three different neurological syndromes for several weeks in vitro. Optimized viral vector techniques and promoters for transgene expression are described. RESULTS Region-specific differences in neuronal form, firing pattern and organization as well as pathological activities were maintained over 40-50 days in culture. Both adeno-associated virus and lentivirus based vectors were persistently expressed from ∼10 days after application, providing 30-40 days to exploit genetically expressed constructs. Different promoters, including hSyn, e/hSyn, CMV and CaMKII, provided cell-type specific transgene expression. The Ca probe GCaMP let us explore epileptogenic synchrony and a FRET-based probe was used to follow activity of the kinase mTORC1. COMPARISON WITH EXISTING METHODS The use of a defined culture medium, with low concentrations of amino acids and no growth factors, permitted organotypic culture of tissue from humans aged 3-62 years. Epileptic activity was maintained and excitability changed relatively little until ∼6 weeks in culture. CONCLUSIONS Characteristic morphology and region-specific neuronal activities are maintained in organotypic culture of tissue from patients diagnosed with mesial temporal lobe epilepsy, cortical dysplasia and cortical glioblastoma. Viral vector techniques permit expression of probes for long-term measurements of multi-cellular activity and intra-cellular signaling.
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Affiliation(s)
- Caroline Le Duigou
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France.
| | - Etienne Savary
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France.
| | - Mélanie Morin-Brureau
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France
| | - Daniel Gomez-Dominguez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, E-28002, Spain
| | - André Sobczyk
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France
| | - Farah Chali
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France
| | - Giampaolo Milior
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France
| | - Larissa Kraus
- Cell Physiology, Technische Universität Braunschweig, Braunschweig, Germany; Charite Universitätsmedizin, Clinical and Experimental Epileptology, Berlin, Germany; Berlin Institute of Health (BIH), 10178, Berlin, Germany
| | - Jochen C Meier
- Cell Physiology, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Bertrand Mathon
- Neurochirurgie, AP-HP, GH Pitie-Salpêtrière-Charles Foix, Paris, 75013, France
| | | | - Georg Dorfmuller
- Neurochirurgie, Fondation Ophtalmologique Rothschild, 75019, Paris, France
| | - Johan Pallud
- Neurochirurgie, Hôpital Sainte-Anne, Paris Descartes University, IMA-BRAIN, Inserm, U894 Centre de Psychiatrie et Neurosciences, Paris, 75014, France
| | - Emmanuel Eugène
- Inserm U839, UPMC Univ Paris 6, Institut du Fer-à-Moulin, Paris, 75005, France
| | - Stéphane Clemenceau
- Neurochirurgie, AP-HP, GH Pitie-Salpêtrière-Charles Foix, Paris, 75013, France
| | - Richard Miles
- Cortex & Epilepsie, Inserm U1127, CNRS UMR7225, UPMC Univ Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, 75013, France, France.
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14
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Kankowski S, Förstera B, Winkelmann A, Knauff P, Wanker EE, You XA, Semtner M, Hetsch F, Meier JC. A Novel RNA Editing Sensor Tool and a Specific Agonist Determine Neuronal Protein Expression of RNA-Edited Glycine Receptors and Identify a Genomic APOBEC1 Dimorphism as a New Genetic Risk Factor of Epilepsy. Front Mol Neurosci 2018; 10:439. [PMID: 29375302 PMCID: PMC5768626 DOI: 10.3389/fnmol.2017.00439] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/18/2017] [Indexed: 01/30/2023] Open
Abstract
C-to-U RNA editing of glycine receptors (GlyR) can play an important role in disease progression of temporal lobe epilepsy (TLE) as it may contribute in a neuron type-specific way to neuropsychiatric symptoms of the disease. It is therefore necessary to develop tools that allow identification of neuron types that express RNA-edited GlyR protein. In this study, we identify NH4 as agonist of C-to-U RNA edited GlyRs. Furthermore, we generated a new molecular C-to-U RNA editing sensor tool that detects Apobec-1- dependent RNA editing in HEPG2 cells and rat primary hippocampal neurons. Using this sensor combined with NH4 application, we were able to identify C-to-U RNA editing-competent neurons and expression of C-to-U RNA-edited GlyR protein in neurons. Bioinformatic analysis of 1,000 Genome Project Phase 3 allele frequencies coding for human Apobec-1 80M and 80I variants showed differences between populations, and the results revealed a preference of the 80I variant to generate RNA-edited GlyR protein. Finally, we established a new PCR-based restriction fragment length polymorphism (RFLP) approach to profile mRNA expression with regard to the genetic APOBEC1 dimorphism of patients with intractable temporal lobe epilepsy (iTLE) and found that the patients fall into two groups. Patients with expression of the Apobec-1 80I variant mostly suffered from simple or complex partial seizures, whereas patients with 80M expression exhibited secondarily generalized seizure activity. Thus, our method allows the characterization of Apobec-1 80M and 80l variants in the brain and provides a new way to epidemiologically and semiologically classify iTLE according to the two different APOBEC1 alleles. Together, these results demonstrate Apobec-1-dependent expression of RNA-edited GlyR protein in neurons and identify the APOBEC1 80I/M-coding alleles as new genetic risk factors for iTLE patients.
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Affiliation(s)
- Svenja Kankowski
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Benjamin Förstera
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig Maximilians University of Munich, Munich, Germany
| | - Aline Winkelmann
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Pina Knauff
- Institute of Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Xintian A You
- Bioinformatics in Medicine, Zuse Institute Berlin, Berlin, Germany
| | - Marcus Semtner
- Cellular Neurosciences, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
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15
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Dejanovic B, Djémié T, Grünewald N, Suls A, Kress V, Hetsch F, Craiu D, Zemel M, Gormley P, Lal D, Myers CT, Mefford HC, Palotie A, Helbig I, Meier JC, De Jonghe P, Weckhuysen S, Schwarz G. Simultaneous impairment of neuronal and metabolic function of mutated gephyrin in a patient with epileptic encephalopathy. EMBO Mol Med 2017; 9:1764. [PMID: 29196314 PMCID: PMC5709744 DOI: 10.15252/emmm.201708525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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16
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Kumar A, Dejanovic B, Hetsch F, Semtner M, Fusca D, Arjune S, Santamaria-Araujo JA, Winkelmann A, Ayton S, Bush AI, Kloppenburg P, Meier JC, Schwarz G, Belaidi AA. S-sulfocysteine/NMDA receptor-dependent signaling underlies neurodegeneration in molybdenum cofactor deficiency. J Clin Invest 2017; 127:4365-4378. [PMID: 29106383 DOI: 10.1172/jci89885] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/26/2017] [Indexed: 02/06/2023] Open
Abstract
Molybdenum cofactor deficiency (MoCD) is an autosomal recessive inborn error of metabolism characterized by neurodegeneration and death in early childhood. The rapid and progressive neurodegeneration in MoCD presents a major clinical challenge and may relate to the poor understanding of the molecular mechanisms involved. Recently, we reported that treating patients with cyclic pyranopterin monophosphate (cPMP) is a successful therapy for a subset of infants with MoCD and prevents irreversible brain damage. Here, we studied S-sulfocysteine (SSC), a structural analog of glutamate that accumulates in the plasma and urine of patients with MoCD, and demonstrated that it acts as an N-methyl D-aspartate receptor (NMDA-R) agonist, leading to calcium influx and downstream cell signaling events and neurotoxicity. SSC treatment activated the protease calpain, and calpain-dependent degradation of the inhibitory synaptic protein gephyrin subsequently exacerbated SSC-mediated excitotoxicity and promoted loss of GABAergic synapses. Pharmacological blockade of NMDA-R, calcium influx, or calpain activity abolished SSC and glutamate neurotoxicity in primary murine neurons. Finally, the NMDA-R antagonist memantine was protective against the manifestation of symptoms in a tungstate-induced MoCD mouse model. These findings demonstrate that SSC drives excitotoxic neurodegeneration in MoCD and introduce NMDA-R antagonists as potential therapeutics for this fatal disease.
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Affiliation(s)
- Avadh Kumar
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Florian Hetsch
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Marcus Semtner
- Cellular Neurosciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Debora Fusca
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Sita Arjune
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Jose Angel Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Aline Winkelmann
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany.,Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Scott Ayton
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley I Bush
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Peter Kloppenburg
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jochen C Meier
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Abdel Ali Belaidi
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
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17
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Chair and Director of Neurobiology Research Legacy Research InstitutePortland, OR, United States
| | | | - Susan A Masino
- Life Sciences Center, Neuroscience and Psychology, Trinity CollegeHartford, CT, United States
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18
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Meier JC, Kankowski S, Krestel H, Hetsch F. RNA Editing-Systemic Relevance and Clue to Disease Mechanisms? Front Mol Neurosci 2016; 9:124. [PMID: 27932948 PMCID: PMC5120146 DOI: 10.3389/fnmol.2016.00124] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 11/04/2016] [Indexed: 11/13/2022] Open
Abstract
Recent advances in sequencing technologies led to the identification of a plethora of different genes and several hundreds of amino acid recoding edited positions. Changes in editing rates of some of these positions were associated with diseases such as atherosclerosis, myopathy, epilepsy, major depression disorder, schizophrenia and other mental disorders as well as cancer and brain tumors. This review article summarizes our current knowledge on that front and presents glycine receptor C-to-U RNA editing as a first example of disease-associated increased RNA editing that includes assessment of disease mechanisms of the corresponding gene product in an animal model.
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Affiliation(s)
- Jochen C Meier
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Svenja Kankowski
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Heinz Krestel
- Neurology, Universitätsspital und Universität Bern Bern, Switzerland
| | - Florian Hetsch
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
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19
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Raltschev C, Hetsch F, Winkelmann A, Meier JC, Semtner M. Electrophysiological Signature of Homomeric and Heteromeric Glycine Receptor Channels. J Biol Chem 2016; 291:18030-40. [PMID: 27382060 DOI: 10.1074/jbc.m116.735084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/06/2022] Open
Abstract
Glycine receptors are chloride-permeable, ligand-gated ion channels and contribute to the inhibition of neuronal firing in the central nervous system or to facilitation of neurotransmitter release if expressed at presynaptic sites. Recent structure-function studies have provided detailed insights into the mechanisms of channel gating, desensitization, and ion permeation. However, most of the work has focused only on comparing a few isoforms, and among studies, different cellular expression systems were used. Here, we performed a series of experiments using recombinantly expressed homomeric and heteromeric glycine receptor channels, including their splice variants, in the same cellular expression system to investigate and compare their electrophysiological properties. Our data show that the current-voltage relationships of homomeric channels formed by the α2 or α3 subunits change upon receptor desensitization from a linear to an inwardly rectifying shape, in contrast to their heteromeric counterparts. The results demonstrate that inward rectification depends on a single amino acid (Ala(254)) at the inner pore mouth of the channels and is closely linked to chloride permeation. We also show that the current-voltage relationships of glycine-evoked currents in primary hippocampal neurons are inwardly rectifying upon desensitization. Thus, the alanine residue Ala(254) determines voltage-dependent rectification upon receptor desensitization and reveals a physio-molecular signature of homomeric glycine receptor channels, which provides unprecedented opportunities for the identification of these channels at the single cell level.
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Affiliation(s)
- Constanze Raltschev
- From the Department of Biomedicine, Cellular Neurophysiology, University of Basel, Pestalozzistrasse 20, 4056 Basel, Switzerland
| | - Florian Hetsch
- the Division of Cell Physiology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany, and
| | - Aline Winkelmann
- the Division of Cell Physiology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany, and
| | - Jochen C Meier
- the Division of Cell Physiology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany, and
| | - Marcus Semtner
- Cellular Neurosciences, Max-Delbrück-Centrum für Molekulare Medizin (MDC), Robert-Rössle-Strasse 10, 13092 Berlin, Germany
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20
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Dejanovic B, Djémié T, Grünewald N, Suls A, Kress V, Hetsch F, Craiu D, Zemel M, Gormley P, Lal D, Myers CT, Mefford HC, Palotie A, Helbig I, Meier JC, De Jonghe P, Weckhuysen S, Schwarz G. Simultaneous impairment of neuronal and metabolic function of mutated gephyrin in a patient with epileptic encephalopathy. EMBO Mol Med 2016; 7:1580-94. [PMID: 26613940 PMCID: PMC4693503 DOI: 10.15252/emmm.201505323] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition plays an important role in neurological disorders. Gephyrin is a central player at inhibitory postsynapses, directly binds and organizes GABAA and glycine receptors (GABAARs and GlyRs), and is thereby indispensable for normal inhibitory neurotransmission. Additionally, gephyrin catalyzes the synthesis of the molybdenum cofactor (MoCo) in peripheral tissue. We identified a de novo missense mutation (G375D) in the gephyrin gene (GPHN) in a patient with epileptic encephalopathy resembling Dravet syndrome. Although stably expressed and correctly folded, gephyrin‐G375D was non‐synaptically localized in neurons and acted dominant‐negatively on the clustering of wild‐type gephyrin leading to a marked decrease in GABAAR surface expression and GABAergic signaling. We identified a decreased binding affinity between gephyrin‐G375D and the receptors, suggesting that Gly375 is essential for gephyrin–receptor complex formation. Surprisingly, gephyrin‐G375D was also unable to synthesize MoCo and activate MoCo‐dependent enzymes. Thus, we describe a missense mutation that affects both functions of gephyrin and suggest that the identified defect at GABAergic synapses is the mechanism underlying the patient's severe phenotype.
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Affiliation(s)
- Borislav Dejanovic
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Tania Djémié
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Nora Grünewald
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Arvid Suls
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium GENOMED, Center for Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Vanessa Kress
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Dana Craiu
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Matthew Zemel
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Padhraig Gormley
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis Lal
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | | | - Candace T Myers
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Aarno Palotie
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Program in Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein Christian Albrechts University, Kiel, Germany Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Peter De Jonghe
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Sarah Weckhuysen
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Inserm U 1127 CNRS UMR 7225 Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Institut du Cerveau et de la Moelle épinière, ICM, Paris, France Centre de reference épilepsies rares, Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière, F-75013, Paris, France
| | - Guenter Schwarz
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany
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21
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Çaliskan G, Müller I, Semtner M, Winkelmann A, Raza AS, Hollnagel JO, Rösler A, Heinemann U, Stork O, Meier JC. Identification of Parvalbumin Interneurons as Cellular Substrate of Fear Memory Persistence. Cereb Cortex 2016; 26:2325-2340. [PMID: 26908632 PMCID: PMC4830301 DOI: 10.1093/cercor/bhw001] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Parvalbumin-positive (PV) basket cells provide perisomatic inhibition in the cortex and hippocampus and control generation of memory-related network activity patterns, such as sharp wave ripples (SPW-R). Deterioration of this class of fast-spiking interneurons has been observed in neuropsychiatric disorders and evidence from animal models suggests their involvement in the acquisition and extinction of fear memories. Here, we used mice with neuron type-targeted expression of the presynaptic gain-of-function glycine receptor RNA variant GlyR α3L185L to genetically enhance the network activity of PV interneurons. These mice showed reduced extinction of contextual fear memory but normal auditory cued fear memory. They furthermore displayed increase of SPW-R activity in area CA3 and CA1 and facilitated propagation of this particular network activity pattern, as determined in ventral hippocampal slice preparations. Individual freezing levels during extinction and SPW-R propagation were correlated across genotypes. The same was true for parvalbumin immunoreactivity in the ventral hippocampus, which was generally augmented in the GlyR mutant mice and correlated with individual freezing levels. Together, these results identify PV interneurons as critical cellular substrate of fear memory persistence and associated SPW-R activity in the hippocampus. Our findings may be relevant for the identification and characterization of physiological correlates for posttraumatic stress and anxiety disorders.
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Affiliation(s)
- Gürsel Çaliskan
- Institute for Neurophysiology, Charité Universitätsmedizin Berlin, Berlin 14195, Germany.,Institute of Biology, Department of Genetics and Molecular Neurobiology, Otto-von-Guericke-University, Magdeburg 39120, Germany
| | - Iris Müller
- Institute of Biology, Department of Genetics and Molecular Neurobiology, Otto-von-Guericke-University, Magdeburg39120, Germany
| | - Marcus Semtner
- Division Cell Physiology, Zoological Institute, Braunschweig38106, Germany
| | - Aline Winkelmann
- Division Cell Physiology, Zoological Institute, Braunschweig 38106, Germany.,RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Ahsan S Raza
- Institute of Biology, Department of Genetics and Molecular Neurobiology, Otto-von-Guericke-University, Magdeburg39120, Germany
| | - Jan O Hollnagel
- Institute for Neurophysiology, Charité Universitätsmedizin Berlin, Berlin 14195, Germany.,Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Anton Rösler
- Institute for Neurophysiology, Charité Universitätsmedizin Berlin, Berlin14195, Germany
| | - Uwe Heinemann
- Institute for Neurophysiology, Charité Universitätsmedizin Berlin, Berlin14195, Germany
| | - Oliver Stork
- Institute of Biology, Department of Genetics and Molecular Neurobiology, Otto-von-Guericke-University, Magdeburg 39120, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Braunschweig 38106, Germany.,RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
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22
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Winkelmann A, Semtner M, Meier JC. Chloride transporter KCC2-dependent neuroprotection depends on the N-terminal protein domain. Cell Death Dis 2015; 6:e1776. [PMID: 26043076 PMCID: PMC4669822 DOI: 10.1038/cddis.2015.127] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 01/04/2023]
Abstract
Neurodegeneration is a serious issue of neurodegenerative diseases including epilepsy. Downregulation of the chloride transporter KCC2 in the epileptic tissue may not only affect regulation of the polarity of GABAergic synaptic transmission but also neuronal survival. Here, we addressed the mechanisms of KCC2-dependent neuroprotection by assessing truncated and mutated KCC2 variants in different neurotoxicity models. The results identify a threonine- and tyrosine-phosphorylation-resistant KCC2 variant with increased chloride transport activity, but they also identify the KCC2 N-terminal domain (NTD) as the relevant minimal KCC2 protein domain that is sufficient for neuroprotection. As ectopic expression of the KCC2-NTD works independently of full-length KCC2-dependent regulation of Cl(-) transport or structural KCC2 C-terminus-dependent regulation of synaptogenesis, our study may pave the way for a selective neuroprotective therapeutic strategy that will be applicable to a wide range of neurodegenerative diseases.
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Affiliation(s)
- A Winkelmann
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
| | - M Semtner
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
| | - J C Meier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
- Division of Cell Physiology, TU Braunschweig, Zoological Institute, Braunschweig 38106, Germany
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23
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Winkelmann A, You X, Grünewald N, Häussler U, Krestel H, Haas CA, Schwarz G, Chen W, Meier JC. Identification of a new genomic hot spot of evolutionary diversification of protein function. PLoS One 2015; 10:e0125413. [PMID: 25955356 PMCID: PMC4425505 DOI: 10.1371/journal.pone.0125413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 03/23/2015] [Indexed: 01/06/2023] Open
Abstract
Establishment of phylogenetic relationships remains a challenging task because it is based on computational analysis of genomic hot spots that display species-specific sequence variations. Here, we identify a species-specific thymine-to-guanine sequence variation in the Glrb gene which gives rise to species-specific splice donor sites in the Glrb genes of mouse and bushbaby. The resulting splice insert in the receptor for the inhibitory neurotransmitter glycine (GlyR) conveys synaptic receptor clustering and specific association with a particular synaptic plasticity-related splice variant of the postsynaptic scaffold protein gephyrin. This study identifies a new genomic hot spot which contributes to phylogenetic diversification of protein function and advances our understanding of phylogenetic relationships.
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Affiliation(s)
- Aline Winkelmann
- RNA editing and Hyperexcitability Disorders Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Xiantian You
- Laboratory of Functional and Medical Genomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nora Grünewald
- Department of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany
| | - Ute Häussler
- Department of Neurosurgery, University of Freiburg, Freiburg, Germany
| | - Heinz Krestel
- Department of Neurology, Bern University Hospital, Bern, Switzerland
| | - Carola A. Haas
- Department of Neurosurgery, University of Freiburg, Freiburg, Germany
| | - Günter Schwarz
- Department of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany
| | - Wei Chen
- Laboratory of Functional and Medical Genomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jochen C. Meier
- RNA editing and Hyperexcitability Disorders Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Life Science Department, Zoological Institute, Division of Cell Physiology, TU Braunschweig, Braunschweig, Germany
- * E-mail:
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24
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Reinthaler EM, Dejanovic B, Lal D, Semtner M, Merkler Y, Reinhold A, Pittrich DA, Hotzy C, Feucht M, Steinböck H, Gruber-Sedlmayr U, Ronen GM, Neophytou B, Geldner J, Haberlandt E, Muhle H, Ikram MA, van Duijn CM, Uitterlinden AG, Hofman A, Altmüller J, Kawalia A, Toliat MR, Nürnberg P, Lerche H, Nothnagel M, Thiele H, Sander T, Meier JC, Schwarz G, Neubauer BA, Zimprich F. Rare variants in γ-aminobutyric acid type A receptor genes in rolandic epilepsy and related syndromes. Ann Neurol 2015; 77:972-86. [PMID: 25726841 DOI: 10.1002/ana.24395] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/12/2015] [Accepted: 02/22/2015] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To test whether mutations in γ-aminobutyric acid type A receptor (GABAA -R) subunit genes contribute to the etiology of rolandic epilepsy (RE) or its atypical variants (ARE). METHODS We performed exome sequencing to compare the frequency of variants in 18 GABAA -R genes in 204 European patients with RE/ARE versus 728 platform-matched controls. Identified GABRG2 variants were functionally assessed for protein stability, trafficking, postsynaptic clustering, and receptor function. RESULTS Of 18 screened GABAA -R genes, we detected an enrichment of rare variants in the GABRG2 gene in RE/ARE patients (5 of 204, 2.45%) in comparison to controls (1 of 723, 0.14%; odds ratio = 18.07, 95% confidence interval = 2.01-855.07, p = 0.0024, pcorr = 0.043). We identified a GABRG2 splice variant (c.549-3T>G) in 2 unrelated patients as well as 3 nonsynonymous variations in this gene (p.G257R, p.R323Q, p.I389V). Functional assessment showed reduced surface expression of p.G257R and decreased GABA-evoked currents for p.R323Q. The p.G257R mutation displayed diminished levels of palmitoylation, a post-translational modification crucial for trafficking of proteins to the cell membrane. Enzymatically raised palmitoylation levels restored the surface expression of the p.G257R variant γ2 subunit. INTERPRETATION The statistical association and the functional evidence suggest that mutations of the GABRG2 gene may increase the risk of RE/ARE. Restoring the impaired membrane trafficking of some GABRG2 mutations by enhancing palmitoylation might be an interesting therapeutic approach to reverse the pathogenic effect of such mutants.
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Affiliation(s)
- Eva M Reinthaler
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Dennis Lal
- Department of Neuropediatrics, University Medical Center Giessen and Marburg, Giessen, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.,Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Marcus Semtner
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Yvonne Merkler
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Annika Reinhold
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Christoph Hotzy
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Martha Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | | | | | - Gabriel M Ronen
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Birgit Neophytou
- Department of Neuropediatrics, St Anna Children's Hospital, Vienna, Austria
| | - Julia Geldner
- Department of Pediatrics, SMZ Süd - Kaiser-Franz-Josef-Hospital, Vienna, Austria
| | - Edda Haberlandt
- Department of Pediatrics, Medical University of Innsbruck, Innsbruck, Austria
| | - Hiltrud Muhle
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian Albrechts University, Kiel, Germany
| | - M Arfan Ikram
- Departments of Epidemiology, Neurology, and Radiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | | | - Andre G Uitterlinden
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Albert Hofman
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Human Genetics, University of Cologne, Cologne, Germany
| | - Amit Kawalia
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Mohammad R Toliat
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | | | - Peter Nürnberg
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.,Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Michael Nothnagel
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Thomas Sander
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Jochen C Meier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Braunschweig University of Technology, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Bernd A Neubauer
- Department of Neuropediatrics, University Medical Center Giessen and Marburg, Giessen, Germany
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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25
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Staudacher JJ, Naarmann-de Vries IS, Ujvari SJ, Klinger B, Kasim M, Benko E, Ostareck-Lederer A, Ostareck DH, Bondke Persson A, Lorenzen S, Meier JC, Blüthgen N, Persson PB, Henrion-Caude A, Mrowka R, Fähling M. Hypoxia-induced gene expression results from selective mRNA partitioning to the endoplasmic reticulum. Nucleic Acids Res 2015; 43:3219-36. [PMID: 25753659 PMCID: PMC4381074 DOI: 10.1093/nar/gkv167] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 02/21/2015] [Indexed: 01/01/2023] Open
Abstract
Protein synthesis is a primary energy-consuming process in the cell. Therefore, under hypoxic conditions, rapid inhibition of global mRNA translation represents a major protective strategy to maintain energy metabolism. How some mRNAs, especially those that encode crucial survival factors, continue to be efficiently translated in hypoxia is not completely understood. By comparing specific transcript levels in ribonucleoprotein complexes, cytoplasmic polysomes and endoplasmic reticulum (ER)-bound ribosomes, we show that the synthesis of proteins encoded by hypoxia marker genes is favoured at the ER in hypoxia. Gene expression profiling revealed that transcripts particularly increased by the HIF-1 transcription factor network show hypoxia-induced enrichment at the ER. We found that mRNAs favourably translated at the ER have higher conservation scores for both the 5'- and 3'-untranslated regions (UTRs) and contain less upstream initiation codons (uAUGs), indicating the significance of these sequence elements for sustained mRNA translation under hypoxic conditions. Furthermore, we found enrichment of specific cis-elements in mRNA 5'- as well as 3'-UTRs that mediate transcript localization to the ER in hypoxia. We conclude that transcriptome partitioning between the cytoplasm and the ER permits selective mRNA translation under conditions of energy shortage.
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Affiliation(s)
- Jonas J Staudacher
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Isabel S Naarmann-de Vries
- University Hospital Aachen, RWTH Aachen University, Department of Intensive and Intermediate Care, Experimental Research Unit, D-52074 Aachen, Germany
| | - Stefanie J Ujvari
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Bertram Klinger
- Humboldt Universität zu Berlin, Institut für Theoretische Biologie, D-10115 Berlin, Germany Charité - Universitätsmedizin Berlin, Institut für Pathologie, D-10117 Berlin, Germany
| | - Mumtaz Kasim
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Edgar Benko
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Antje Ostareck-Lederer
- University Hospital Aachen, RWTH Aachen University, Department of Intensive and Intermediate Care, Experimental Research Unit, D-52074 Aachen, Germany
| | - Dirk H Ostareck
- University Hospital Aachen, RWTH Aachen University, Department of Intensive and Intermediate Care, Experimental Research Unit, D-52074 Aachen, Germany
| | - Anja Bondke Persson
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Stephan Lorenzen
- Universitätsklinikum Jena, Klinik für Innere Medizin III, AG Experimentelle Nephrologie, D-07743 Jena, Germany
| | - Jochen C Meier
- Max Delbrück Center for Molecular Medicine, RNA Editing and Hyperexcitability Disorders Helmholtz Group, D-13125 Berlin, Germany TU Braunschweig, Zoological Institute, Division of Cell Physiology, D-38106 Braunschweig, Germany
| | - Nils Blüthgen
- Humboldt Universität zu Berlin, Institut für Theoretische Biologie, D-10115 Berlin, Germany Charité - Universitätsmedizin Berlin, Institut für Pathologie, D-10117 Berlin, Germany
| | - Pontus B Persson
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
| | - Alexandra Henrion-Caude
- Hôpital Necker-Enfants Malades, Université Paris Descartes, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1163 and Imagine Foundation, 75015 Paris, France
| | - Ralf Mrowka
- Universitätsklinikum Jena, Klinik für Innere Medizin III, AG Experimentelle Nephrologie, D-07743 Jena, Germany
| | - Michael Fähling
- Charité - Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Charitéplatz 1, D-10117 Berlin, Germany
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26
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Fossati G, Morini R, Corradini I, Antonucci F, Trepte P, Edry E, Sharma V, Papale A, Pozzi D, Defilippi P, Meier JC, Brambilla R, Turco E, Rosenblum K, Wanker EE, Ziv NE, Menna E, Matteoli M. Reduced SNAP-25 increases PSD-95 mobility and impairs spine morphogenesis. Cell Death Differ 2015; 22:1425-36. [PMID: 25678324 DOI: 10.1038/cdd.2014.227] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 10/22/2014] [Accepted: 11/26/2014] [Indexed: 12/24/2022] Open
Abstract
Impairment of synaptic function can lead to neuropsychiatric disorders collectively referred to as synaptopathies. The SNARE protein SNAP-25 is implicated in several brain pathologies and, indeed, brain areas of psychiatric patients often display reduced SNAP-25 expression. It has been recently found that acute downregulation of SNAP-25 in brain slices impairs long-term potentiation; however, the processes through which this occurs are still poorly defined. We show that in vivo acute downregulation of SNAP-25 in CA1 hippocampal region affects spine number. Consistently, hippocampal neurons from SNAP-25 heterozygous mice show reduced densities of dendritic spines and defective PSD-95 dynamics. Finally, we show that, in brain, SNAP-25 is part of a molecular complex including PSD-95 and p140Cap, with p140Cap being capable to bind to both SNAP-25 and PSD-95. These data demonstrate an unexpected role of SNAP-25 in controlling PSD-95 clustering and open the possibility that genetic reductions of the protein levels - as occurring in schizophrenia - may contribute to the pathology through an effect on postsynaptic function and plasticity.
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Affiliation(s)
- G Fossati
- 1] Department of Biotechnology and Translational Medicine, University of Milan, Milano 20129, Italy [2] Humanitas Clinical and Research Center, Laboratory of Pharmacology and Brain Pathology, Via Manzoni 56, Rozzano, 20089 Milano, Italy
| | - R Morini
- 1] Department of Biotechnology and Translational Medicine, University of Milan, Milano 20129, Italy [2] Humanitas Clinical and Research Center, Laboratory of Pharmacology and Brain Pathology, Via Manzoni 56, Rozzano, 20089 Milano, Italy
| | - I Corradini
- 1] Department of Biotechnology and Translational Medicine, University of Milan, Milano 20129, Italy [2] Istituto di Neuroscienze del CNR, Milano 20129, Italy
| | - F Antonucci
- 1] Department of Biotechnology and Translational Medicine, University of Milan, Milano 20129, Italy [2] Istituto di Neuroscienze del CNR, Milano 20129, Italy
| | - P Trepte
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine (MDC), Berlin 13125, Germany
| | - E Edry
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Adult Brain (CGMB), Haifa University, Haifa, Israel
| | - V Sharma
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Adult Brain (CGMB), Haifa University, Haifa, Israel
| | - A Papale
- Division of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute and University, Milano 20132, Italy
| | - D Pozzi
- Humanitas Clinical and Research Center, Laboratory of Pharmacology and Brain Pathology, Via Manzoni 56, Rozzano, 20089 Milano, Italy
| | - P Defilippi
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino 10124, Italy
| | - J C Meier
- 1] RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany [2] TU Braunschweig, Zoological Institute, Division of Cell Biology and Cell Physiology, Braunschweig, Germany
| | - R Brambilla
- Division of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute and University, Milano 20132, Italy
| | - E Turco
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino 10124, Italy
| | - K Rosenblum
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Adult Brain (CGMB), Haifa University, Haifa, Israel
| | - E E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine (MDC), Berlin 13125, Germany
| | - N E Ziv
- Network Biology Labs and Faculty of Medicine, Technion, 33000 Haifa, Israel
| | - E Menna
- 1] Humanitas Clinical and Research Center, Laboratory of Pharmacology and Brain Pathology, Via Manzoni 56, Rozzano, 20089 Milano, Italy [2] Istituto di Neuroscienze del CNR, Milano 20129, Italy
| | - M Matteoli
- 1] Department of Biotechnology and Translational Medicine, University of Milan, Milano 20129, Italy [2] Humanitas Clinical and Research Center, Laboratory of Pharmacology and Brain Pathology, Via Manzoni 56, Rozzano, 20089 Milano, Italy
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27
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Kasim M, Benko E, Winkelmann A, Mrowka R, Staudacher JJ, Persson PB, Scholz H, Meier JC, Fähling M. Shutdown of achaete-scute homolog-1 expression by heterogeneous nuclear ribonucleoprotein (hnRNP)-A2/B1 in hypoxia. J Biol Chem 2014; 289:26973-26988. [PMID: 25124043 DOI: 10.1074/jbc.m114.579391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The basic helix-loop-helix transcription factor hASH1, encoded by the ASCL1 gene, plays an important role in neurogenesis and tumor development. Recent findings indicate that local oxygen tension is a critical determinant for the progression of neuroblastomas. Here we investigated the molecular mechanisms underlying the oxygen-dependent expression of hASH1 in neuroblastoma cells. Exposure of human neuroblastoma-derived Kelly cells to 1% O2 significantly decreased ASCL1 mRNA and hASH1 protein levels. Using reporter gene assays, we show that the response of hASH1 to hypoxia is mediated mainly by post-transcriptional inhibition via the ASCL1 mRNA 5'- and 3'-UTRs, whereas additional inhibition of the ASCL1 promoter was observed under prolonged hypoxia. By RNA pulldown experiments followed by MALDI/TOF-MS analysis, we identified heterogeneous nuclear ribonucleoprotein (hnRNP)-A2/B1 and hnRNP-R as interactors binding directly to the ASCL1 mRNA 5'- and 3'-UTRs and influencing its expression. We further demonstrate that hnRNP-A2/B1 is a key positive regulator of ASCL1, findings that were also confirmed by analysis of a large compilation of gene expression data. Our data suggest that a prominent down-regulation of hnRNP-A2/B1 during hypoxia is associated with the post-transcriptional suppression of hASH1 synthesis. This novel post-transcriptional mechanism for regulating hASH1 levels will have important implications in neural cell fate development and disease.
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Affiliation(s)
- Mumtaz Kasim
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin
| | - Edgar Benko
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin
| | - Aline Winkelmann
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, D-13125 Berlin, and
| | - Ralf Mrowka
- Klinik für Innere Medizin III, AG Experimentelle Nephrologie, Universitätsklinikum Jena, D-07743 Jena, Germany
| | - Jonas J Staudacher
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin
| | - Pontus B Persson
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin
| | - Holger Scholz
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin
| | - Jochen C Meier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, D-13125 Berlin, and
| | - Michael Fähling
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10117 Berlin,.
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28
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Dejanovic B, Semtner M, Ebert S, Lamkemeyer T, Neuser F, Lüscher B, Meier JC, Schwarz G. Palmitoylation of gephyrin controls receptor clustering and plasticity of GABAergic synapses. PLoS Biol 2014; 12:e1001908. [PMID: 25025157 PMCID: PMC4099074 DOI: 10.1371/journal.pbio.1001908] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/05/2014] [Indexed: 12/03/2022] Open
Abstract
Gephyrin, the principal scaffolding protein at inhibitory synapses, needs to be palmitoylated in order to cluster and to assemble functional synapses. Postsynaptic scaffolding proteins regulate coordinated neurotransmission by anchoring and clustering receptors and adhesion molecules. Gephyrin is the major instructive molecule at inhibitory synapses, where it clusters glycine as well as major subsets of GABA type A receptors (GABAARs). Here, we identified palmitoylation of gephyrin as an important mechanism of strengthening GABAergic synaptic transmission, which is regulated by GABAAR activity. We mapped palmitoylation to Cys212 and Cys284, which are critical for both association of gephyrin with the postsynaptic membrane and gephyrin clustering. We identified DHHC-12 as the principal palmitoyl acyltransferase that palmitoylates gephyrin. Furthermore, gephyrin pamitoylation potentiated GABAergic synaptic transmission, as evidenced by an increased amplitude of miniature inhibitory postsynaptic currents. Consistently, inhibiting gephyrin palmitoylation either pharmacologically or by expression of palmitoylation-deficient gephyrin reduced the gephyrin cluster size. In aggregate, our study reveals that palmitoylation of gephyrin by DHHC-12 contributes to dynamic and functional modulation of GABAergic synapses. Efficient signal transmission at synapses is essential for higher brain functions. Inhibitory signaling in the brain takes place primarily at GABA (γ-aminobutyric acid)-ergic synapses. GABA type A receptors (GABAARs) are clustered at the postsynaptic side by a scaffold composed of the peripheral membrane protein gephyrin. We demonstrate that gephyrin is modulated by palmitoylation, a reversible posttranslational fatty acid modification. Palmitoylation facilitates the membrane association of gephyrin and is therefore essential for normal clustering of gephyrin at GABAergic synapses. Reciprocally, palmitoylation of gephyrin is regulated by GABAAR activity. Of the 23 known palmitoyl transferases that catalyze the palmitoylation of proteins in human cells, we identified one enzyme, DHHC-12, to specifically modify gephyrin. Our results provide a new aspect to the posttranslational control of synaptic plasticity.
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Affiliation(s)
- Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Marcus Semtner
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Silvia Ebert
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Tobias Lamkemeyer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Franziska Neuser
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Bernhard Lüscher
- Department of Biology and Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jochen C. Meier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- * E-mail:
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29
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Meier JC, Meier J, Semtner M, Winkelmann A, Wolfart J. Presynaptic mechanisms of neuronal plasticity and their role in epilepsy. Front Cell Neurosci 2014; 8:164. [PMID: 24987332 PMCID: PMC4060558 DOI: 10.3389/fncel.2014.00164] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 05/29/2014] [Indexed: 11/17/2022] Open
Abstract
Synaptic communication requires constant adjustments of pre- and postsynaptic efficacies. In addition to synaptic long term plasticity, the presynaptic machinery underlies homeostatic regulations which prevent out of range transmitter release. In this minireview we will discuss the relevance of selected presynaptic mechanisms to epilepsy including voltage- and ligand-gated ion channels as well as cannabinoid and adenosine receptor signaling.
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Affiliation(s)
| | - Jochen Meier
- RNA Editing and Hyperexcitability Disorders, Max Delbrück Centre for Molecular Medicine, Neurosciences Berlin, Germany
| | - Marcus Semtner
- RNA Editing and Hyperexcitability Disorders, Max Delbrück Centre for Molecular Medicine, Neurosciences Berlin, Germany
| | - Aline Winkelmann
- RNA Editing and Hyperexcitability Disorders, Max Delbrück Centre for Molecular Medicine, Neurosciences Berlin, Germany
| | - Jakob Wolfart
- Oscar Langendorff Institute of Physiology, University of Rostock Rostock, Germany
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30
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Notelaers K, Rocha S, Paesen R, Swinnen N, Vangindertael J, Meier JC, Rigo JM, Ameloot M, Hofkens J. Membrane distribution of the glycine receptor α3 studied by optical super-resolution microscopy. Histochem Cell Biol 2014; 142:79-90. [PMID: 24553792 DOI: 10.1007/s00418-014-1197-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2014] [Indexed: 11/24/2022]
Abstract
In this study, the effect of glycine receptor (GlyR) α3 alternative RNA splicing on the distribution of receptors in the membrane of human embryonic kidney 293 cells is investigated using optical super-resolution microscopy. Direct stochastic optical reconstruction microscopy is used to image both α3K and α3L splice variants individually and together using single- and dual-color imaging. Pair correlation analysis is used to extract quantitative measures from the resulting images. Autocorrelation analysis of the individually expressed variants reveals clustering of both variants, yet with differing properties. The cluster size is increased for α3L compared to α3K (mean radius 92 ± 4 and 56 ± 3 nm, respectively), yet an even bigger difference is found in the cluster density (9,870 ± 1,433 and 1,747 ± 200 μm(-2), respectively). Furthermore, cross-correlation analysis revealed that upon co-expression, clusters colocalize on the same spatial scales as for individually expressed receptors (mean co-cluster radius 94 ± 6 nm). These results demonstrate that RNA splicing determines GlyR α3 membrane distribution, which has consequences for neuronal GlyR physiology and function.
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Affiliation(s)
- Kristof Notelaers
- Biomedical Research Institute, Hasselt University and School of Life Sciences, Transnational University Limburg, Agoralaan Gebouw C, 3590, Diepenbeek, Belgium
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31
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Winkelmann A, Maggio N, Eller J, Caliskan G, Semtner M, Häussler U, Jüttner R, Dugladze T, Smolinsky B, Kowalczyk S, Chronowska E, Schwarz G, Rathjen FG, Rechavi G, Haas CA, Kulik A, Gloveli T, Heinemann U, Meier JC. Changes in neural network homeostasis trigger neuropsychiatric symptoms. J Clin Invest 2014; 124:696-711. [PMID: 24430185 PMCID: PMC3904623 DOI: 10.1172/jci71472] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 10/31/2013] [Indexed: 12/13/2022] Open
Abstract
The mechanisms that regulate the strength of synaptic transmission and intrinsic neuronal excitability are well characterized; however, the mechanisms that promote disease-causing neural network dysfunction are poorly defined. We generated mice with targeted neuron type-specific expression of a gain-of-function variant of the neurotransmitter receptor for glycine (GlyR) that is found in hippocampectomies from patients with temporal lobe epilepsy. In this mouse model, targeted expression of gain-of-function GlyR in terminals of glutamatergic cells or in parvalbumin-positive interneurons persistently altered neural network excitability. The increased network excitability associated with gain-of-function GlyR expression in glutamatergic neurons resulted in recurrent epileptiform discharge, which provoked cognitive dysfunction and memory deficits without affecting bidirectional synaptic plasticity. In contrast, decreased network excitability due to gain-of-function GlyR expression in parvalbumin-positive interneurons resulted in an anxiety phenotype, but did not affect cognitive performance or discriminative associative memory. Our animal model unveils neuron type-specific effects on cognition, formation of discriminative associative memory, and emotional behavior in vivo. Furthermore, our data identify a presynaptic disease-causing molecular mechanism that impairs homeostatic regulation of neural network excitability and triggers neuropsychiatric symptoms.
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Affiliation(s)
- Aline Winkelmann
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Nicola Maggio
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Joanna Eller
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Gürsel Caliskan
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Marcus Semtner
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Ute Häussler
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - René Jüttner
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Tamar Dugladze
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Birthe Smolinsky
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Sarah Kowalczyk
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Ewa Chronowska
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Günter Schwarz
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Fritz G. Rathjen
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Gideon Rechavi
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Carola A. Haas
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Akos Kulik
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Tengis Gloveli
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Uwe Heinemann
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Jochen C. Meier
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany.
RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany.
Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany.
Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany.
Department of Physiology II, University of Freiburg, Freiburg, Germany.
Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
BrainLinks-BrainTools, Cluster of Excellence and
BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
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Förstera B, a Dzaye OD, Winkelmann A, Semtner M, Benedetti B, Markovic DS, Synowitz M, Wend P, Fähling M, Junier MP, Glass R, Kettenmann H, Meier JC. Intracellular glycine receptor function facilitates glioma formation in vivo. J Cell Sci 2014; 127:3687-98. [DOI: 10.1242/jcs.146662] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The neuronal function of Cys-loop neurotransmitter receptors is established; however, their role in non-neuronal cells is poorly defined. As brain tumors accumulate the neurotransmitter glycine, we studied expression and function of glycine receptors (GlyR) in glioma cells. Human brain tumor biopsies selectively expressed GlyR subunits with nuclear import signal (NLS, α1 and α3). The mouse glioma cell line GL261 expressed GlyR α1, and knock-down of α1 protein expression impaired self-renewal capacity and tumorigenicity of GL261 glioma cells as evidenced by the neurosphere assay and GL261 cell inoculation in vivo, respectively. We furthermore show that the pronounced tumorigenic effect of GlyR α1 relies on a new intracellular signaling function that depends on the NLS region in the large cytosolic loop and impacts on GL261 glioma cell gene regulation. Stable expression of GlyR α1 and α3 loops rescued self-renewal capacity of GlyR α1 knock-down cells, which demonstrates their functional equivalence. The new intracellular signaling function identified here goes beyond the well-established role of GlyRs as neuronal ligand-gated ion channels and defines NLS-containing GlyRs as novel potential targets for brain tumor therapies.
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Kowalczyk S, Winkelmann A, Smolinsky B, Förstera B, Neundorf I, Schwarz G, Meier JC. Direct binding of GABAA receptor β2 and β3 subunits to gephyrin. Eur J Neurosci 2012. [PMID: 23205938 DOI: 10.1111/ejn.12078] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
GABAergic transmission is essential to brain function, and a large repertoire of GABA type A receptor (GABA(A) R) subunits is at a neuron's disposition to serve this function. The glycine receptor (GlyR)-associated protein gephyrin has been shown to be essential for the clustering of a subset of GABA(A) R. Despite recent progress in the field of gephyrin-dependent mechanisms of postsynaptic GABA(A) R stabilisation, the role of gephyrin in synaptic GABA(A) R localisation has remained a complex matter with many open questions. Here, we analysed comparatively the interaction of purified rat gephyrin and mouse brain gephyrin with the large cytoplasmic loops of GABA(A) R α1, α2, β2 and β3 subunits. Binding affinities were determined using surface plasmon resonance spectroscopy, and showed an ~ 20-fold lower affinity of the β2 loop to gephyrin as compared to the GlyR β loop-gephyrin interaction. We also probed in vivo binding in primary cortical neurons by the well-established use of chimaeras of GlyR α1 that harbour respective gephyrin-binding motifs derived from the different GABA(A) R subunits. These studies identify a novel gephyrin-binding motif in GABA(A) R β2 and β3 large cytoplasmic loops.
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Affiliation(s)
- Sarah Kowalczyk
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
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Notelaers K, Smisdom N, Rocha S, Janssen D, Meier JC, Rigo JM, Hofkens J, Ameloot M. Ensemble and single particle fluorimetric techniques in concerted action to study the diffusion and aggregation of the glycine receptor α3 isoforms in the cell plasma membrane. Biochim Biophys Acta 2012; 1818:3131-40. [PMID: 22906711 DOI: 10.1016/j.bbamem.2012.08.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 08/03/2012] [Accepted: 08/11/2012] [Indexed: 10/28/2022]
Abstract
The spatio-temporal membrane behavior of glycine receptors (GlyRs) is known to be of influence on receptor homeostasis and functionality. In this work, an elaborate fluorimetric strategy was applied to study the GlyR α3K and L isoforms. Previously established differential clustering, desensitization and synaptic localization of these isoforms imply that membrane behavior is crucial in determining GlyR α3 physiology. Therefore diffusion and aggregation of homomeric α3 isoform-containing GlyRs were studied in HEK 293 cells. A unique combination of multiple diffraction-limited ensemble average methods and subdiffraction single particle techniques was used in order to achieve an integrated view of receptor properties. Static measurements of aggregation were performed with image correlation spectroscopy (ICS) and, single particle based, direct stochastic optical reconstruction microscopy (dSTORM). Receptor diffusion was measured by means of raster image correlation spectroscopy (RICS), temporal image correlation spectroscopy (TICS), fluorescence recovery after photobleaching (FRAP) and single particle tracking (SPT). The results show a significant difference in diffusion coefficient and cluster size between the isoforms. This reveals a positive correlation between desensitization and diffusion and disproves the notion that receptor aggregation is a universal mechanism for accelerated desensitization. The difference in diffusion coefficient between the clustering GlyR α3L and the non-clustering GlyR α3K cannot be explained by normal diffusion. SPT measurements indicate that the α3L receptors undergo transient trapping and directed motion, while the GlyR α3K displays mild hindered diffusion. These findings are suggestive of differential molecular interaction of the isoforms after incorporation in the membrane.
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Affiliation(s)
- Kristof Notelaers
- Biomedical Research Institute, Hasselt University and School of Life Sciences, Transnational University Limburg, Agoralaan gebouw C, 3590 Diepenbeek, Belgium
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35
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Meier JC, Harvey RJ, Seeburg P. Frontiers in molecular neuroscience - résumé and perspective. Front Mol Neurosci 2012; 4:58. [PMID: 22232574 PMCID: PMC3248788 DOI: 10.3389/fnmol.2011.00058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 12/15/2011] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jochen C Meier
- Max Delbrück Center for Molecular Medicine Berlin, Germany
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36
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Grantyn R, Henneberger C, Jüttner R, Meier JC, Kirischuk S. Functional hallmarks of GABAergic synapse maturation and the diverse roles of neurotrophins. Front Cell Neurosci 2011; 5:13. [PMID: 21772813 PMCID: PMC3131524 DOI: 10.3389/fncel.2011.00013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 06/17/2011] [Indexed: 12/03/2022] Open
Abstract
Functional impairment of the adult brain can result from deficits in the ontogeny of GABAergic synaptic transmission. Gene defects underlying autism spectrum disorders, Rett’s syndrome or some forms of epilepsy, but also a diverse set of syndromes accompanying perinatal trauma, hormonal imbalances, intake of sleep-inducing or mood-improving drugs or, quite common, alcohol intake during pregnancy can alter GABA signaling early in life. The search for therapeutically relevant endogenous molecules or exogenous compounds able to alleviate the consequences of dysfunction of GABAergic transmission in the embryonic or postnatal brain requires a clear understanding of its site- and state-dependent development. At the level of single synapses, it is necessary to discriminate between presynaptic and postsynaptic alterations, and to define parameters that can be regarded as both suitable and accessible for the quantification of developmental changes. Here we focus on the performance of GABAergic synapses in two brain structures, the hippocampus and the superior colliculus, describe some novel aspects of neurotrophin effects during the development of GABAergic synaptic transmission and examine the applicability of the following rules: (1) synaptic transmission starts with GABA, (2) nascent/immature GABAergic synapses operate in a ballistic mode (multivesicular release), (3) immature synaptic terminals release vesicles with higher probability than mature synapses, (4) immature GABAergic synapses are prone to paired pulse and tetanic depression, (5) synapse maturation is characterized by an increasing dominance of synchronous over asynchronous release, (6) in immature neurons GABA acts as a depolarizing transmitter, (7) synapse maturation implies inhibitory postsynaptic current shortening due to an increase in alpha1 subunit expression, (8) extrasynaptic (tonic) conductances can inhibit the development of synaptic (phasic) GABA actions.
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Affiliation(s)
- Rosemarie Grantyn
- Institute of Neurophysiology, University Medicine Charité Berlin, Germany
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Benko E, Winkelmann A, Meier JC, Persson PB, Scholz H, Fähling M. Phorbol-Ester Mediated Suppression of hASH1 Synthesis: Multiple Ways to Keep the Level Down. Front Mol Neurosci 2011; 4:1. [PMID: 21441980 PMCID: PMC3057490 DOI: 10.3389/fnmol.2011.00001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 01/20/2011] [Indexed: 11/13/2022] Open
Abstract
Human achaete-scute homolog-1 (hASH1), encoded by the human ASCL1 gene, belongs to the family of basic helix-loop-helix transcription factors. hASH1 and its mammalian homolog Mash1 are expressed in the central and peripheral nervous system during development, and promote early neuronal differentiation. Furthermore, hASH1 is involved in the specification of neuronal subtype identities. Misexpression of the transcription factor is correlated with a variety of tumors, including lung cancer and neuroendocrine tumors. To gain insights into the molecular mechanisms of hASH1 regulation, we screened for conditions causing changes in hASH1 gene expression rate. We found that treatment of human neuroblastoma-derived Kelly cells with phorbol 12-myristate 13-acetate (PMA) resulted in a fast, strong and long-lasting suppression of hASH1 synthesis. Reporter gene assays with constructs, in which the luciferase activity was controlled either by the ASCL1 promoter or by the hASH1 mRNA untranslated regions (UTRs), revealed a mainly UTR-dependent mechanism. The hASH1 promoter activity was decreased only after 48 h of PMA administration. Our data indicate that different mechanisms acting consecutively at the transcriptional and post-transcriptional level are responsible for hASH1 suppression after PMA treatment. We provide evidence that short term inhibition of hASH1 synthesis is attributed to hASH1 mRNA destabilization, which seems to depend mainly on protein kinase C activity. Under prolonged conditions (48 h), hASH1 suppression is mediated by decreased promoter activity and inhibition of mRNA translation.
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Affiliation(s)
- Edgar Benko
- Institut für Vegetative Physiologie, Charité - Universitätsmedizin Berlin Berlin, Germany
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38
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Förstera B, Belaidi AA, Jüttner R, Bernert C, Tsokos M, Lehmann TN, Horn P, Dehnicke C, Schwarz G, Meier JC. Irregular RNA splicing curtails postsynaptic gephyrin in the cornu ammonis of patients with epilepsy. Brain 2010; 133:3778-94. [DOI: 10.1093/brain/awq298] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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39
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Affiliation(s)
- William Wisden
- Division of Cell and Molecular Biology, Imperial College London London, UK
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40
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Legendre P, Förstera B, Jüttner R, Meier JC. Glycine Receptors Caught between Genome and Proteome - Functional Implications of RNA Editing and Splicing. Front Mol Neurosci 2009; 2:23. [PMID: 19936314 PMCID: PMC2779093 DOI: 10.3389/neuro.02.023.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 10/13/2009] [Indexed: 11/13/2022] Open
Abstract
Information processing in the brain requires a delicate balance between excitation and inhibition. Glycine receptors (GlyR) are involved in inhibitory mechanisms mainly at a synaptic level, but potential novel roles for these receptors recently emerged due to the discovery of posttranscriptional processing. GLR transcripts are edited through enzymatic modification of a single nucleotide leading to amino acid substitution within the neurotransmitter binding domain. RNA editing produces gain-of-function receptors well suited for generation and maintenance of tonic inhibition of neuronal excitability. As neuronal activity deprivation in early stages of development or in epileptic tissue is detrimental to neurons and because RNA editing of GlyR is up-regulated in temporal lobe epilepsy patients with a severe course of disease a pathophysiological role of these receptors emerges. This review contains a state-of-the-art discussion of (patho)physiological implications of GlyR RNA editing.
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Eichler SA, Förstera B, Smolinsky B, Jüttner R, Lehmann TN, Fähling M, Schwarz G, Legendre P, Meier JC. Splice-specific roles of glycine receptor alpha3 in the hippocampus. Eur J Neurosci 2009; 30:1077-91. [PMID: 19723286 DOI: 10.1111/j.1460-9568.2009.06903.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glycine receptor (GlyR) alpha3 is involved in vision, and processing of acoustic and nociceptive signals, and RNA editing of GLRA3 transcripts was associated with hippocampal pathophysiology of mesial temporal lobe epilepsy (TLE). However, neither the role of GlyR alpha3 splicing in hippocampal neurons nor the expression of splice variants have yet been elucidated. We report here that the long (L) splice variant of GlyR alpha3 predominates in the brain of rodents. Cellular analysis using primary hippocampal neurons and hippocampus cryosections revealed preferential association of synaptic alpha3L clusters with glutamatergic nerve endings in strata granulare and pyramidale. In primary hippocampal neurons GlyR alpha3L clusters also preferred glutamatergic nerve endings while alpha3K was mainly in a diffuse state. Co-expression of GlyR beta subunit with alpha3L or alpha3K produced heteromeric receptor clusters and favoured their association with GABAergic terminals. However, heteromeric alpha3L was still more efficient than heteromeric alpha3K in associating with glutamatergic nerve endings. To give physiological relevance to these results we have finally analysed GlyR alpha3 splicing in human hippocampus obtained from patients with intractable TLE. As up-regulation of alpha3K occurred at the expense of alpha3L in TLE patients with a severe course of disease and a high degree of hippocampal damage, our results again involve post-transcriptional processing of GLRA3 transcripts in the pathophysiology of TLE.
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42
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Fähling M, Mrowka R, Steege A, Kirschner KM, Benko E, Förstera B, Persson PB, Thiele BJ, Meier JC, Scholz H. Translational regulation of the human achaete-scute homologue-1 by fragile X mental retardation protein. J Biol Chem 2008; 284:4255-66. [PMID: 19097999 DOI: 10.1074/jbc.m807354200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fragile X syndrome is a common inherited cause of mental retardation that results from loss or mutation of the fragile X mental retardation protein (FMRP). In this study, we identified the mRNA of the basic helix-loop-helix transcription factor human achaete-scute homologue-1 (hASH1 or ASCL1), which is required for normal development of the nervous system and has been implicated in the formation of neuroendocrine tumors, as a new FMRP target. Using a double-immunofluorescent staining technique we detected an overlapping pattern of both proteins in the hippocampus, temporal cortex, subventricular zone, and cerebellum of newborn rats. Forced expression of FMRP and gene silencing by small interference RNA transfection revealed a positive correlation between the cellular protein levels of FMRP and hASH1. A luciferase reporter construct containing the 5'-untranslated region of hASH1 mRNA was activated by the full-length FMRP, but not by naturally occurring truncated FMR proteins, in transient co-transfections. The responsible cis-element was mapped by UV-cross-linking experiments and reporter mutagenesis assays to a (U)(10) sequence located in the 5'-untranslated region of the hASH1 mRNA. Sucrose density gradient centrifugation revealed that hASH1 transcripts were translocated into a translationally active polysomal fraction upon transient transfection of HEK293 cells with FMRP, thus indicating translational activation of hASH1 mRNA. In conclusion, we identified hASH1 as a novel downstream target of FMRP. Improved translation efficiency of hASH1 mRNA by FMRP may represent an important regulatory switch in neuronal differentiation.
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Affiliation(s)
- Michael Fähling
- Charité, Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Tucholskystrasse 2, D-10117 Berlin
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43
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Eichler SA, Kirischuk S, Jüttner R, Schafermeier PK, Legendre P, Lehmann TN, Gloveli T, Grantyn R, Meier JC. Glycinergic tonic inhibition of hippocampal neurons with depolarizing GABAergic transmission elicits histopathological signs of temporal lobe epilepsy. J Cell Mol Med 2008; 12:2848-66. [PMID: 19210758 PMCID: PMC3828897 DOI: 10.1111/j.1582-4934.2008.00357.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 04/17/2008] [Indexed: 01/13/2023] Open
Abstract
An increasing number of epilepsy patients are afflicted with drug-resistant temporal lobe epilepsy (TLE) and require alternative therapeutic approaches. High-affinity glycine receptors (haGlyRs) are functionally adapted to tonic inhibition due to their response to hippocampal ambient glycine, and their synthesis is activity-dependent. Therefore, in our study, we scanned TLE hippocampectomies for expression of haGlyRs and characterized the effects mediated by these receptors using primary hippocampal neurons. Increased haGlyR expression occurred in TLE hippocampi obtained from patients with a severe course of disease. Furthermore, in TLE patients, haGlyR and potassium chloride cotransporter 2 (KCC2) expressions were inversely regulated. To examine this potential causal relationship with respect to TLE histopathology, we established a hippocampal cell culture system utilising tonic inhibition mediated by haGlyRs in response to hippocam-pal ambient glycine and in the context of a high Cl equilibrium potential, as is the case in TLE hippocampal neurons. We showed that hypoactive neurons increase their ratio between glutamatergic and GABAergic synapses, reduce their dendrite length and finally undergo excitotoxicity. Pharmacological dissection of the underlying processes revealed ionotropic glutamate and TrkB receptors as critical mediators between neuronal hypoactivity and the emergence of these TLE-characteristic histopathological signs. Moreover, our results indicate a beneficial role for KCC2, because decreasing the Cl- equilibrium potential by KCC2 expression also rescued hypoactive hippocampal neurons. Thus, our data support a causal relationship between increased haGlyR expression and the emergence of histopathological TLE-characteristic signs, and they establish a pathophysiological role for neuronal hypoactivity in the context of a high Cl- equilibrium potential.
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Affiliation(s)
- Sabrina A Eichler
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular MedicineBerlin, Germany
| | - Sergei Kirischuk
- Developmental Physiology, Institute for Neurophysiology, Charité University Medicine BerlinGermany
| | - René Jüttner
- Developmental Neurobiology, Max Delbrück Center for Molecular MedicineBerlin, Germany
| | - Philipp K Schafermeier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular MedicineBerlin, Germany
| | - Pascal Legendre
- UMR CNRS 7102 NPA, Université Pierre et Marie CurieParis, France
| | | | - Tengis Gloveli
- Cellular and Network Physiology, Institute of Neurophysiology, Charité University Medicine BerlinGermany
| | - Rosemarie Grantyn
- Developmental Physiology, Institute for Neurophysiology, Charité University Medicine BerlinGermany
| | - Jochen C Meier
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular MedicineBerlin, Germany
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44
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Smolinsky B, Eichler SA, Buchmeier S, Meier JC, Schwarz G. Splice-specific functions of gephyrin in molybdenum cofactor biosynthesis. J Biol Chem 2008; 283:17370-9. [PMID: 18411266 DOI: 10.1074/jbc.m800985200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gephyrin is a multifunctional protein involved in the clustering of inhibitory neuroreceptors. In addition, gephyrin catalyzes the last step in molybdenum cofactor (Moco) biosynthesis essential for the activities of Mo-dependent enzymes such as sulfite oxidase and xanthine oxidoreductase. Functional complexity and diversity of gephyrin is believed to be regulated by alternative splicing in a tissue-specific manner. Here, we investigated eight gephyrin variants with combinations of seven alternatively spliced exons located in the N-terminal G domain, the central domain, and the C-terminal E domain. Their activity in Moco synthesis was analyzed in vivo by reconstitution of gephyrin-deficient L929 cells, which were found to be defective in the G domain of gephyrin. Individual domain functions were assayed in addition and confirmed that variants containing either an additional C5 cassette or missing the C6 cassette are inactive in Moco synthesis. In contrast, different alterations within the central domain retained the Moco synthetic activity of gephyrin. The recombinant gephyrin G domain containing the C5 cassette forms dimers in solution, binds molybdopterin, but is unable to catalyze molybdopterin (MPT) adenylylation. Determination of Moco and MPT content in different tissues showed that besides liver and kidney, brain was capable of synthesizing Moco most efficiently. Subsequent analysis of cultured neurons and glia cells demonstrated glial Moco synthesis due to the expression of gephyrins containing the cassettes C2 and C6 with and without C3.1.
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Affiliation(s)
- Birthe Smolinsky
- Institute of Biochemistry and Center for Molecular Medicine, University of Cologne, 50674 Cologne, Germany
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Abstract
Information transfer in the brain requires a homeostatic control of neuronal excitability. Therefore, a functional balance between excitatory and inhibitory systems is established during development. This review contains recent information about the molecular mechanisms orchestrating the establishment and maintenance of this excitation-inhibition (E-I) balance, and it reviews examples of deregulation of inhibitory and excitatory systems at a molecular, network and disease level of investigation.
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Affiliation(s)
- Sabrina A Eichler
- RNA Editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine Berlin, Germany
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46
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Lardi-Studler B, Smolinsky B, Petitjean CM, Koenig F, Sidler C, Meier JC, Fritschy JM, Schwarz G. Vertebrate-specific sequences in the gephyrin E-domain regulate cytosolic aggregation and postsynaptic clustering. J Cell Sci 2007; 120:1371-82. [PMID: 17374639 DOI: 10.1242/jcs.003905] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Gephyrin is a multifunctional protein contributing to molybdenum cofactor (Moco) synthesis and postsynaptic clustering of glycine and GABA(A) receptors. It contains three major functional domains (G-C-E) and forms cytosolic aggregates and postsynaptic clusters by unknown mechanisms. Here, structural determinants of gephyrin aggregation and clustering were investigated by neuronal transfection of EGFP-tagged deletion and mutant gephyrin constructs. EGFP-gephyrin formed postsynaptic clusters containing endogenous gephyrin and GABA(A)-receptors. Isolated GC- or E-domains failed to aggregate and exerted dominant-negative effects on endogenous gephyrin clustering. A construct interfering with intermolecular E-domain dimerization readily auto-aggregated but showed impaired postsynaptic clustering. Finally, two mutant constructs with substitution of vertebrate-specific E-domain sequences with homologue bacterial MoeA sequences uncovered a region crucial for gephyrin clustering. One construct failed to aggregate, but retained Moco biosynthesis capacity, demonstrating the independence of gephyrin enzymatic activity and aggregation. Reinserting two vertebrate-specific residues restored gephyrin aggregation and increased formation of postsynaptic clusters containing GABA(A) receptors at the expense of PSD-95 clusters - a marker of glutamatergic synapses. These results underscore the key role of specific E-domain regions distinct from the known dimerization interface for controlling gephyrin aggregation and postsynaptic clustering and suggest that formation of gephyrin clusters influences the homeostatic balance between inhibitory and excitatory synapses.
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Affiliation(s)
- Barbara Lardi-Studler
- Institute of Pharmacology and Toxicology, University of Zurich, CH-8057 Zurich, Switzerland
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47
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Singh B, Henneberger C, Betances D, Arevalo MA, Rodríguez-Tébar A, Meier JC, Grantyn R. Altered balance of glutamatergic/GABAergic synaptic input and associated changes in dendrite morphology after BDNF expression in BDNF-deficient hippocampal neurons. J Neurosci 2006; 26:7189-200. [PMID: 16822976 PMCID: PMC6673958 DOI: 10.1523/jneurosci.5474-05.2006] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cultured neurons from bdnf-/- mice display reduced densities of synaptic terminals, although in vivo these deficits are small or absent. Here we aimed at clarifying the local responses to postsynaptic brain-derived neurotrophic factor (BDNF). To this end, solitary enhanced green fluorescent protein (EGFP)-labeled hippocampal neurons from bdnf-/- mice were compared with bdnf-/- neurons after transfection with BDNF, bdnf-/- neurons after transient exposure to exogenous BDNF, and bdnf+/+ neurons in wild-type cultures. Synapse development was evaluated on the basis of presynaptic immunofluorescence and whole-cell patch-clamp recording of miniature postsynaptic currents. It was found that neurons expressing BDNF::EGFP for at least 16 h attracted a larger number of synaptic terminals than BDNF-deficient control neurons. Transfected BDNF formed clusters in the vicinity of glutamatergic terminals and produced a stronger upregulation of synaptic terminal numbers than high levels of ambient BDNF. Glutamatergic and GABAergic synapses reacted differently to postsynaptic BDNF: glutamatergic input increased, whereas GABAergic input decreased. BDNF::EGFP-expressing neurons also differed from BDNF-deficient neurons in their dendrite morphology: they exhibited weaker dendrite elongation and stronger dendrite initiation. The upregulation of glutamatergic synaptic input and the BDNF-induced downregulation of GABAergic synaptic terminal numbers by postsynaptic BDNF depended on tyrosine receptor kinase B activity, as deduced from the blocking effects of K252a. The suppression of dendrite elongation was also prevented by block of tyrosine receptor kinase B but required, in addition, glutamate receptor activity. Dendritic length decreased with the number of glutamatergic contacts. These results illuminate the role of BDNF as a retrograde synaptic regulator of synapse development and the dependence of dendrite elongation on glutamatergic input.
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Affiliation(s)
- B Singh
- Developmental Physiology Group, Johannes Mueller Institute for Neurophysiology, University Medical School (Charité) of the Humboldt University, D-10117 Berlin, Germany
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48
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Meier JC, Henneberger C, Melnick I, Racca C, Harvey RJ, Heinemann U, Schmieden V, Grantyn R. RNA editing produces glycine receptor alpha3(P185L), resulting in high agonist potency. Nat Neurosci 2005; 8:736-44. [PMID: 15895087 DOI: 10.1038/nn1467] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Accepted: 04/20/2005] [Indexed: 11/09/2022]
Abstract
The function of supramedullary glycine receptors (GlyRs) is still unclear. Using Wistar rat collicular slices, we demonstrate GlyR-mediated inhibition of spike discharge elicited by low glycine (10 microM). Searching for the molecular basis of this phenomenon, we identified a new GlyR isoform. GlyR alpha3(P185L), a result of cytidine 554 deamination, confers high glycine sensitivity (EC50 approximately 5 microM) to neurons and thereby promotes the generation of sustained chloride conductances associated with tonic inhibition. The level of GlyR alpha3-C554U RNA editing is sensitive to experimentally induced brain lesion, inhibition of cytidine deamination by zebularine and inhibition of mRNA transcription by actinomycin D, but not to blockade of protein synthesis by cycloheximide. Conditional regulation of GlyR alpha3(P185L) is thus likely to be part of a post-transcriptional adaptive mechanism in neurons with enhanced excitability.
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Affiliation(s)
- Jochen C Meier
- Department of Developmental Physiology, Johannes-Mueller Center of Physiology, Charité University Medicine, 10117 Berlin, Germany.
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Henneberger C, Jüttner R, Schmidt SA, Walter J, Meier JC, Rothe T, Grantyn R. GluR- and TrkB-mediated maturation of GABA receptor function during the period of eye opening. Eur J Neurosci 2005; 21:431-40. [PMID: 15673442 DOI: 10.1111/j.1460-9568.2005.03869.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Synapse maturation includes the shortening of postsynaptic currents, due to changes in the subunit composition of respective transmitter receptors. Patch clamp experiments revealed that GABAergic inhibitory postsynaptic currents (ISPCs) of superior colliculus neurons significantly shorten from postnatal day (P)1 to P21. The change started after P6 and was steepest between P12 and P15, i.e. around eye opening. It was accompanied by enhanced sensitivity to zolpidem and increased expression of GABAAR alpha1 mRNA, whereas the level of alpha3 mRNA decreased. This result is consistent with the hypothesis that the IPSC kinetics of developing collicular neurons is determined by the level of alpha1/alpha3. As alpha1/alpha3 peaked when N-methyl-D-aspartate receptor (NMDAR)-mediated synaptic currents reached their maximum (P12) it was asked whether NMDAR activity can shape the kinetics of GABAergic IPSCs. Cultured collicular neurons were treated with NMDA or NMDAR block, and it was found that the former resulted in faster and the latter in slower IPSC decay. Group I mGluR blockade had no effect. Experiments with bdnf-/- mice revealed that, with some delay, the increase of alpha1/alpha3 mRNA also occurred in the chronic absence of brain-derived neurotrophic factor (BDNF) and, again, this was accompanied by the shortening of IPSCs. In addition, there was an age-dependent depression of IPSC amplitudes by endogenous BDNF, which might reflect the developmental increase in the expression of GABAAR gamma2L, as opposed to gamma2S. Together, these experiments suggest that the GABAAR alpha subunit switch and the associated change in the IPSC kinetics were specifically controlled by NMDAR activity and independent on the signalling through group I mGluRs or TrkB.
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MESH Headings
- Age Factors
- Animals
- Animals, Newborn
- Blotting, Northern
- Brain-Derived Neurotrophic Factor/deficiency
- Dizocilpine Maleate/pharmacology
- Embryo, Mammalian
- Eye/growth & development
- GABA Agonists/pharmacology
- Gene Expression Regulation, Developmental/drug effects
- Gene Expression Regulation, Developmental/physiology
- In Vitro Techniques
- Mice
- Mice, Knockout
- N-Methylaspartate/pharmacology
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Neurons/cytology
- Neurons/drug effects
- Neurons/physiology
- Patch-Clamp Techniques/methods
- Pyridines/pharmacology
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, trkB/physiology
- Receptors, GABA-A/physiology
- Receptors, Glutamate/physiology
- Receptors, N-Methyl-D-Aspartate/agonists
- Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors
- Receptors, N-Methyl-D-Aspartate/physiology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Superior Colliculi/cytology
- Superior Colliculi/growth & development
- Synapses/drug effects
- Synapses/physiology
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
- Valine/analogs & derivatives
- Valine/pharmacology
- Zolpidem
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Affiliation(s)
- Christian Henneberger
- Sensory and Developmental Physiology, Johannes Mueller Centre for Physiology, University Medicine (Charité), Tucholskystr. 2, D-10117 Berlin, Germany
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