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Cuhadar U, Calzado-Reyes L, Pascual-Caro C, Aberra AS, Ritzau-Jost A, Aggarwal A, Ibata K, Podgorski K, Yuzaki M, Geis C, Hallerman S, Hoppa MB, de Juan-Sanz J. Activity-driven synaptic translocation of LGI1 controls excitatory neurotransmission. Cell Rep 2024; 43:114186. [PMID: 38700985 DOI: 10.1016/j.celrep.2024.114186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 12/14/2023] [Accepted: 04/17/2024] [Indexed: 05/05/2024] Open
Abstract
The fine control of synaptic function requires robust trans-synaptic molecular interactions. However, it remains poorly understood how trans-synaptic bridges change to reflect the functional states of the synapse. Here, we develop optical tools to visualize in firing synapses the molecular behavior of two trans-synaptic proteins, LGI1 and ADAM23, and find that neuronal activity acutely rearranges their abundance at the synaptic cleft. Surprisingly, synaptic LGI1 is primarily not secreted, as described elsewhere, but exo- and endocytosed through its interaction with ADAM23. Activity-driven translocation of LGI1 facilitates the formation of trans-synaptic connections proportionally to the history of activity of the synapse, adjusting excitatory transmission to synaptic firing rates. Accordingly, we find that patient-derived autoantibodies against LGI1 reduce its surface fraction and cause increased glutamate release. Our findings suggest that LGI1 abundance at the synaptic cleft can be acutely remodeled and serves as a critical control point for synaptic function.
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Affiliation(s)
- Ulku Cuhadar
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Lorenzo Calzado-Reyes
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Carlos Pascual-Caro
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Aman S Aberra
- Department of Biology, Dartmouth College, Hanover, NH 03755, USA
| | - Andreas Ritzau-Jost
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, 04317 Leipzig, Germany
| | - Abhi Aggarwal
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Keiji Ibata
- Department of Neurophysiology, Keio University, Tokyo 160-8582, Japan
| | | | - Michisuke Yuzaki
- Department of Neurophysiology, Keio University, Tokyo 160-8582, Japan
| | - Christian Geis
- Department of Neurology, Section Translational Neuroimmunology, Jena University Hospital, 07747 Jena, Germany
| | - Stefan Hallerman
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, 04317 Leipzig, Germany
| | - Michael B Hoppa
- Department of Biology, Dartmouth College, Hanover, NH 03755, USA
| | - Jaime de Juan-Sanz
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France.
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2
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Miyazaki Y, Otsuka T, Yamagata Y, Endo T, Sanbo M, Sano H, Kobayashi K, Inahashi H, Kornau HC, Schmitz D, Prüss H, Meijer D, Hirabayashi M, Fukata Y, Fukata M. Oligodendrocyte-derived LGI3 and its receptor ADAM23 organize juxtaparanodal Kv1 channel clustering for short-term synaptic plasticity. Cell Rep 2024; 43:113634. [PMID: 38194969 PMCID: PMC10828548 DOI: 10.1016/j.celrep.2023.113634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/31/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024] Open
Abstract
Neurodevelopmental disorders, such as intellectual disability (ID), epilepsy, and autism, involve altered synaptic transmission and plasticity. Functional characterization of their associated genes is vital for understanding physio-pathological brain functions. LGI3 is a recently recognized ID-associated gene encoding a secretory protein related to an epilepsy-gene product, LGI1. Here, we find that LGI3 is uniquely secreted from oligodendrocytes in the brain and enriched at juxtaparanodes of myelinated axons, forming nanoscale subclusters. Proteomic analysis using epitope-tagged Lgi3 knockin mice shows that LGI3 uses ADAM23 as a receptor and selectively co-assembles with Kv1 channels. A lack of Lgi3 in mice disrupts juxtaparanodal clustering of ADAM23 and Kv1 channels and suppresses Kv1-channel-mediated short-term synaptic plasticity. Collectively, this study identifies an extracellular organizer of juxtaparanodal Kv1 channel clustering for finely tuned synaptic transmission. Given the defective secretion of the LGI3 missense variant, we propose a molecular pathway, the juxtaparanodal LGI3-ADAM23-Kv1 channel, for understanding neurodevelopmental disorders.
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Affiliation(s)
- Yuri Miyazaki
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Takeshi Otsuka
- Section of Cellular Electrophysiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan
| | - Yoko Yamagata
- Section of Multilayer Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | | | - Makoto Sanbo
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hiromi Sano
- Division of Behavioral Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Kenta Kobayashi
- Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan; Section of Viral Vector Development, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | - Hiroki Inahashi
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hans-Christian Kornau
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Neuroscience Research Center (NWFZ), Cluster NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Dietmar Schmitz
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Neuroscience Research Center (NWFZ), Cluster NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Helmholtz Innovation Lab BaoBab (Brain Antibody-omics and B-cell Lab), Berlin, Germany; Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Dies Meijer
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
| | - Masumi Hirabayashi
- Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan; Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
| | - Masaki Fukata
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan.
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3
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Martin SP, Leeman-Markowski BA. Proposed mechanisms of tau: relationships to traumatic brain injury, Alzheimer's disease, and epilepsy. Front Neurol 2024; 14:1287545. [PMID: 38249745 PMCID: PMC10797726 DOI: 10.3389/fneur.2023.1287545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/30/2023] [Indexed: 01/23/2024] Open
Abstract
Traumatic brain injury (TBI), Alzheimer's disease (AD), and epilepsy share proposed mechanisms of injury, including neuronal excitotoxicity, cascade signaling, and activation of protein biomarkers such as tau. Although tau is typically present intracellularly, in tauopathies, phosphorylated (p-) and hyper-phosphorylated (hp-) tau are released extracellularly, the latter leading to decreased neuronal stability and neurofibrillary tangles (NFTs). Tau cleavage at particular sites increases susceptibility to hyper-phosphorylation, NFT formation, and eventual cell death. The relationship between tau and inflammation, however, is unknown. In this review, we present evidence for an imbalanced endoplasmic reticulum (ER) stress response and inflammatory signaling pathways resulting in atypical p-tau, hp-tau and NFT formation. Further, we propose tau as a biomarker for neuronal injury severity in TBI, AD, and epilepsy. We present a hypothesis of tau phosphorylation as an initial acute neuroprotective response to seizures/TBI. However, if the underlying seizure pathology or TBI recurrence is not effectively treated, and the pathway becomes chronically activated, we propose a "tipping point" hypothesis that identifies a transition of tau phosphorylation from neuroprotective to injurious. We outline the role of amyloid beta (Aβ) as a "last ditch effort" to revert the cell to programmed death signaling, that, when fails, transitions the mechanism from injurious to neurodegenerative. Lastly, we discuss targets along these pathways for therapeutic intervention in AD, TBI, and epilepsy.
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Affiliation(s)
- Samantha P. Martin
- Comprehensive Epilepsy Center, New York University Langone Health, New York, NY, United States
- Department of Neurology, New York University Langone Health, New York, NY, United States
- New York University Grossman School of Medicine, New York, NY, United States
- VA New York Harbor Healthcare System, New York, NY, United States
| | - Beth A. Leeman-Markowski
- Comprehensive Epilepsy Center, New York University Langone Health, New York, NY, United States
- Department of Neurology, New York University Langone Health, New York, NY, United States
- VA New York Harbor Healthcare System, New York, NY, United States
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4
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Iqbal M, Lewis SL, Padhye S, Jinwal UK. Updates on Aβ Processing by Hsp90, BRICHOS, and Newly Reported Distinctive Chaperones. Biomolecules 2023; 14:16. [PMID: 38254616 PMCID: PMC10812967 DOI: 10.3390/biom14010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Alzheimer's disease (AD) is an extremely devastating neurodegenerative disease, and there is no cure for it. AD is specified as the misfolding and aggregation of amyloid-β protein (Aβ) and abnormalities in hyperphosphorylated tau protein. Current approaches to treat Alzheimer's disease have had some success in slowing down the disease's progression. However, attempts to find a cure have been largely unsuccessful, most likely due to the complexity associated with AD pathogenesis. Hence, a shift in focus to better understand the molecular mechanism of Aβ processing and to consider alternative options such as chaperone proteins seems promising. Chaperone proteins act as molecular caretakers to facilitate cellular homeostasis under standard conditions. Chaperone proteins like heat shock proteins (Hsps) serve a pivotal role in correctly folding amyloid peptides, inhibiting mitochondrial dysfunction, and peptide aggregation. For instance, Hsp90 plays a significant role in maintaining cellular homeostasis through its protein folding mechanisms. In this review, we analyze the most recent studies from 2020 to 2023 and provide updates on Aβ regulation by Hsp90, BRICHOS domain chaperone, and distinctive newly reported chaperones.
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Affiliation(s)
| | | | | | - Umesh Kumar Jinwal
- Department of Pharmaceutical Sciences, USF-Health Taneja College of Pharmacy, University of South Florida, Tampa, FL 33612, USA; (M.I.)
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5
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Extrémet J, Ramirez-Franco J, Fronzaroli-Molinieres L, Boumedine-Guignon N, Ankri N, El Far O, Garrido JJ, Debanne D, Russier M. Rescue of Normal Excitability in LGI1-Deficient Epileptic Neurons. J Neurosci 2023; 43:8596-8606. [PMID: 37863654 PMCID: PMC10727174 DOI: 10.1523/jneurosci.0701-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/08/2023] [Accepted: 10/14/2023] [Indexed: 10/22/2023] Open
Abstract
Leucine-rich glioma inactivated 1 (LGI1) is a glycoprotein secreted by neurons, the deletion of which leads to autosomal dominant lateral temporal lobe epilepsy. We previously showed that LGI1 deficiency in a mouse model (i.e., knock-out for LGI1 or KO-Lgi1) decreased Kv1.1 channel density at the axon initial segment (AIS) and at presynaptic terminals, thus enhancing both intrinsic excitability and glutamate release. However, it is not known whether normal excitability can be restored in epileptic neurons. Here, we show that the selective expression of LGI1 in KO-Lgi1 neurons from mice of both sexes, using single-cell electroporation, reduces intrinsic excitability and restores both the Kv1.1-mediated D-type current and Kv1.1 channels at the AIS. In addition, we show that the homeostatic-like shortening of the AIS length observed in KO-Lgi1 neurons is prevented in neurons electroporated with the Lgi1 gene. Furthermore, we reveal a spatial gradient of intrinsic excitability that is centered on the electroporated neuron. We conclude that expression of LGI1 restores normal excitability through functional Kv1 channels at the AIS.SIGNIFICANCE STATEMENT The lack of leucine-rich glioma inactivated 1 (LGI1) protein induces severe epileptic seizures that leads to death. Enhanced intrinsic and synaptic excitation in KO-Lgi1 mice is because of the decrease in Kv1.1 channels in CA3 neurons. However, the conditions to restore normal excitability profile in epileptic neurons remain to be defined. We show here that the expression of LGI1 in KO-Lgi1 neurons in single neurons reduces intrinsic excitability, and restores both the Kv1.1-mediated D-type current and Kv1.1 channels at the axon initial segment (AIS). Furthermore, the homeostatic shortening of the AIS length observed in KO-Lgi1 neurons is prevented in neurons in which the Lgi1 gene has been rescued. We conclude that LGI1 constitutes a critical factor to restore normal excitability in epileptic neurons.
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Affiliation(s)
- Johanna Extrémet
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Jorge Ramirez-Franco
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Laure Fronzaroli-Molinieres
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Norah Boumedine-Guignon
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Norbert Ankri
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Oussama El Far
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Juan José Garrido
- Cajal Institute, Consejo Superior de Investigaciones Cientificas, Madrid, 28002, Spain
| | - Dominique Debanne
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Michaël Russier
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
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6
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Nosková L, Fukata Y, Stránecký V, Šaligová J, Bodnárová O, Giertlová M, Fukata M, Kmoch S. ADAM22 ethnic-specific variant reducing binding of membrane-associated guanylate kinases causes focal epilepsy and behavioural disorder. Brain Commun 2023; 5:fcad295. [PMID: 37953841 PMCID: PMC10636567 DOI: 10.1093/braincomms/fcad295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 07/19/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023] Open
Abstract
Pathogenic variants of ADAM22 affecting either its biosynthesis and/or its interactions with either LGI1 and/or PSD-95 have been recently identified in individuals with developmental and epileptic encephalopathy. Here, we describe a girl with seizures, delayed psychomotor development, and behavioural disorder, carrying a homozygous variant in ADAM22 (NM_021723.5:c.2714C > T). The variant has a surprisingly high frequency in the Roma population of the Czech and Slovak Republic, with 11 of 213 (∼5.2%) healthy Roma individuals identified as heterozygous carriers. Structural in silico characterization revealed that the genetic variant encodes the missense variant p.S905F, which localizes to the PDZ-binding motif of ADAM22. Studies in transiently transfected mammalian cells revealed that the variant has no effect on biosynthesis and stability of ADAM22. Rather, protein-protein interaction studies showed that the p.S905F variant specifically impairs ADAM22 binding to PSD-95 and other proteins from a family of membrane-associated guanylate kinases, while it has only minor effect on ADAM22-LGI1 interaction. Our study indicates that a significant proportion of epilepsy in patients of Roma ancestry may be caused by homozygous c.2714C > T variants in ADAM22. The study of this ADAM22 variant highlights a novel pathogenic mechanism of ADAM22 dysfunction and reconfirms an essential role of interaction of ADAM22 with membrane-associated guanylate kinases in seizure protection in humans.
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Affiliation(s)
- Lenka Nosková
- Research Unit for Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University in Prague, 128 08 Prague 2, Czech Republic
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan
- Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Viktor Stránecký
- Research Unit for Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University in Prague, 128 08 Prague 2, Czech Republic
| | - Jana Šaligová
- Children's Faculty Hospital, Košice 040 11, Slovakia
| | | | - Mária Giertlová
- Medical Genetics Outpatient Service, Unilabs Slovakia Ltd, Košice 040 01, Slovakia
- Department of Paediatric and Adolescent Medicine, Faculty of Medicine, P.J. Šafárik University,Košice 040 01, Slovak Republic
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Stanislav Kmoch
- Research Unit for Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University in Prague, 128 08 Prague 2, Czech Republic
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7
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Zhou L, Wang K, Xu Y, Dong BB, Wu DC, Wang ZX, Wang XT, Cai XY, Yang JT, Zheng R, Chen W, Shen Y, Wei JS. A patient-derived mutation of epilepsy-linked LGI1 increases seizure susceptibility through regulating K v1.1. Cell Biosci 2023; 13:34. [PMID: 36804022 PMCID: PMC9940402 DOI: 10.1186/s13578-023-00983-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/04/2023] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Autosomal dominant lateral temporal epilepsy (ADLTE) is an inherited syndrome caused by mutations in the leucine-rich glioma inactivated 1 (LGI1) gene. It is known that functional LGI1 is secreted by excitatory neurons, GABAergic interneurons, and astrocytes, and regulates AMPA-type glutamate receptor-mediated synaptic transmission by binding ADAM22 and ADAM23. However, > 40 LGI1 mutations have been reported in familial ADLTE patients, more than half of which are secretion-defective. How these secretion-defective LGI1 mutations lead to epilepsy is unknown. RESULTS We identified a novel secretion-defective LGI1 mutation from a Chinese ADLTE family, LGI1-W183R. We specifically expressed mutant LGI1W183R in excitatory neurons lacking natural LGI1, and found that this mutation downregulated Kv1.1 activity, led to neuronal hyperexcitability and irregular spiking, and increased epilepsy susceptibility in mice. Further analysis revealed that restoring Kv1.1 in excitatory neurons rescued the defect of spiking capacity, improved epilepsy susceptibility, and prolonged the life-span of mice. CONCLUSIONS These results describe a role of secretion-defective LGI1 in maintaining neuronal excitability and reveal a new mechanism in the pathology of LGI1 mutation-related epilepsy.
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Affiliation(s)
- Lin Zhou
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Kang Wang
- grid.452661.20000 0004 1803 6319Department of Neurology, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003 China
| | - Yuxiang Xu
- grid.256922.80000 0000 9139 560XSchool of Life Sciences, Henan University, Kaifeng, 475004 China
| | - Bin-Bin Dong
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Deng-Chang Wu
- grid.452661.20000 0004 1803 6319Department of Neurology, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003 China
| | - Zhao-Xiang Wang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Xin-Tai Wang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Xin-Yu Cai
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Jin-Tao Yang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Rui Zheng
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Wei Chen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020, China.
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020, China.
| | - Jian-She Wei
- School of Life Sciences, Henan University, Kaifeng, 475004, China.
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8
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Ramirez-Franco J, Debreux K, Extremet J, Maulet Y, Belghazi M, Villard C, Sangiardi M, Youssouf F, El Far L, Lévêque C, Debarnot C, Marchot P, Paneva S, Debanne D, Russier M, Seagar M, Irani SR, El Far O. Patient-derived antibodies reveal the subcellular distribution and heterogeneous interactome of LGI1. Brain 2022; 145:3843-3858. [PMID: 35727946 DOI: 10.1093/brain/awac218] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/14/2022] Open
Abstract
Autoantibodies against leucine-rich glioma-inactivated 1 (LGI1) occur in patients with encephalitis who present with frequent focal seizures and a pattern of amnesia consistent with focal hippocampal damage. To investigate whether the cellular and subcellular distribution of LGI1 may explain the localization of these features, and hence gain broader insights into LGI1's neurobiology, we analysed the detailed localization of LGI1 and the diversity of its protein interactome, in mouse brains using patient-derived recombinant monoclonal LGI1 antibodies. Combined immunofluorescence and mass spectrometry analyses showed that LGI1 is enriched in excitatory and inhibitory synaptic contact sites, most densely within CA3 regions of the hippocampus. LGI1 is secreted in both neuronal somatodendritic and axonal compartments, and occurs in oligodendrocytic, neuro-oligodendrocytic and astro-microglial protein complexes. Proteomic data support the presence of LGI1-Kv1-MAGUK complexes, but did not reveal LGI1 complexes with postsynaptic glutamate receptors. Our results extend our understanding of regional, cellular and subcellular LGI1 expression profiles and reveal novel LGI1-associated complexes, thus providing insights into the complex biology of LGI1 and its relationship to seizures and memory loss.
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Affiliation(s)
- Jorge Ramirez-Franco
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Kévin Debreux
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Johanna Extremet
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Yves Maulet
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Maya Belghazi
- Aix-Marseille University, CNRS, Institute of Neurophysiopathology (INP), PINT, PFNT, 13385 cedex 5 Marseille, France
| | - Claude Villard
- Aix-Marseille University, CNRS, Institute of Neurophysiopathology (INP), PINT, PFNT, 13385 cedex 5 Marseille, France
| | - Marion Sangiardi
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Fahamoe Youssouf
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Lara El Far
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Christian Lévêque
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Claire Debarnot
- Laboratoire 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', CNRS, Aix-Marseille Université, 13288 cedex 09 Marseille, France
| | - Pascale Marchot
- Laboratoire 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', CNRS, Aix-Marseille Université, 13288 cedex 09 Marseille, France
| | - Sofija Paneva
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Dominique Debanne
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Michael Russier
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Michael Seagar
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Department of Neurology, Oxford University Hospitals, Oxford, UK
| | - Oussama El Far
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
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9
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Syrbe S. Developmental and epileptic encephalopathies – therapeutic consequences of genetic testing. MED GENET-BERLIN 2022. [DOI: 10.1515/medgen-2022-2145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Developmental and epileptic encephalopathies comprise a heterogeneous group of monogenic neurodevelopmental disorders characterized by early-onset seizures, marked epileptic activity and abnormal neurocognitive development. The identification of an increasing number of underlying genetic alterations and their pathophysiological roles in cellular signaling drives the way toward novel precision therapies. The implementation of novel treatments that target the underlying mechanisms gives hope for disease modification that will improve not only the seizure burden but also the neurodevelopmental outcome of affected children. So far, beneficial effects are mostly reported in individual trials and small numbers of patients. There is a need for international collaborative studies to define the natural history and relevant outcome measures and to test novel pharmacological approaches.
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Affiliation(s)
- Steffen Syrbe
- Division of Paediatric Epileptology, Centre for Paediatrics and Adolescent Medicine , University Hospital Heidelberg , Im Neuenheimer Feld 430 , Heidelberg , Germany
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10
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van der Knoop MM, Maroofian R, Fukata Y, van Ierland Y, Karimiani EG, Lehesjoki AE, Muona M, Paetau A, Miyazaki Y, Hirano Y, Selim L, de França M, Fock RA, Beetz C, Ruivenkamp CAL, Eaton AJ, Morneau-Jacob FD, Sagi-Dain L, Shemer-Meiri L, Peleg A, Haddad-Halloun J, Kamphuis DJ, Peeters-Scholte CMPCD, Kurul SH, Horvath R, Lochmüller H, Murphy D, Waldmüller S, Spranger S, Overberg D, Muir AM, Rad A, Vona B, Abdulwahad F, Maddirevula S, Povolotskaya IS, Voinova VY, Gowda VK, Srinivasan VM, Alkuraya FS, Mefford HC, Alfadhel M, Haack TB, Striano P, Severino M, Fukata M, Hilhorst-Hofstee Y, Houlden H. Biallelic ADAM22 pathogenic variants cause progressive encephalopathy and infantile-onset refractory epilepsy. Brain 2022; 145:2301-2312. [PMID: 35373813 PMCID: PMC9337806 DOI: 10.1093/brain/awac116] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/31/2022] [Accepted: 03/04/2022] [Indexed: 12/03/2022] Open
Abstract
Pathogenic variants in A Disintegrin And Metalloproteinase (ADAM) 22, the postsynaptic cell membrane receptor for the glycoprotein leucine-rich repeat glioma-inactivated protein 1 (LGI1), have been recently associated with recessive developmental and epileptic encephalopathy. However, so far, only two affected individuals have been described and many features of this disorder are unknown. We refine the phenotype and report 19 additional individuals harbouring compound heterozygous or homozygous inactivating ADAM22 variants, of whom 18 had clinical data available. Additionally, we provide follow-up data from two previously reported cases. All affected individuals exhibited infantile-onset, treatment-resistant epilepsy. Additional clinical features included moderate to profound global developmental delay/intellectual disability (20/20), hypotonia (12/20) and delayed motor development (19/20). Brain MRI findings included cerebral atrophy (13/20), supported by post-mortem histological examination in patient-derived brain tissue, cerebellar vermis atrophy (5/20), and callosal hypoplasia (4/20). Functional studies in transfected cell lines confirmed the deleteriousness of all identified variants and indicated at least three distinct pathological mechanisms: (i) defective cell membrane expression; (ii) impaired LGI1-binding; and/or (iii) impaired interaction with the postsynaptic density protein PSD-95. We reveal novel clinical and molecular hallmarks of ADAM22 deficiency and provide knowledge that might inform clinical management and early diagnostics.
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Affiliation(s)
- Marieke M van der Knoop
- Department of Child Neurology, Sophia Children’s Hospital, Erasmus University Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Reza Maroofian
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Yvette van Ierland
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Ehsan G Karimiani
- Next Generation Genetic Polyclinic, Razavi International Hospital, Mashhad, Iran
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St. George’s University, London SW17 0RE, UK
| | - Anna Elina Lehesjoki
- Folkhälsan Research Center, Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki 00290, Finland
| | - Mikko Muona
- Folkhälsan Research Center, Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki 00290, Finland
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland,00100 Helsinki, Finland
- Blueprint Genetics, 02150 Espoo, Finland
| | - Anders Paetau
- Department of Pathology, Medicum, University of Helsinki, 00100 Helsinki, Finland
| | - Yuri Miyazaki
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Yoko Hirano
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-8655, Japan
| | - Laila Selim
- Division of Neurology and Metabolism, Kasr Al Ainy School of Medicine, Cairo University Children Hospital, Cairo, Egypt
| | - Marina de França
- Department of Morphology and Genetics, Clinical Center of Medical Genetics Federal, University of São Paulo, São Paulo, Brazil
| | - Rodrigo Ambrosio Fock
- Department of Morphology and Genetics, Clinical Center of Medical Genetics Federal, University of São Paulo, São Paulo, Brazil
| | | | - Claudia A L Ruivenkamp
- Department of Clinical Genetics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Alison J Eaton
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | | | - Lena Sagi-Dain
- Affiliated to the Ruth and Bruce Rappaport Faculty of Medicine Technion-Israel Institute of Technology, Genetics Institute, Carmel Medical Center,Haifa, Israel
| | | | - Amir Peleg
- Affiliated to the Ruth and Bruce Rappaport Faculty of Medicine Technion-Israel Institute of Technology, Genetics Institute, Carmel Medical Center,Haifa, Israel
| | - Jumana Haddad-Halloun
- Department of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Daan J Kamphuis
- Department of Neurology, Reinier de Graaf Hospital, 2625 AD Delft, The Netherlands
| | | | - Semra Hiz Kurul
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Rita Horvath
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Hanns Lochmüller
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
- Department of Neuropediatrics and Muscle Disorders, Medical Center–University of Freiburg, Faculty of Medicine, Freiburg, Germany
- Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - David Murphy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Stephan Waldmüller
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany
| | | | - David Overberg
- Department of Pediatrics, Klinikum Bremen-Mitte, Bremen 28205, Germany
| | - Alison M Muir
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children’s Hospital, Seattle, WA 98195, USA
| | - Aboulfazl Rad
- Department of Otolaryngology - Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, Tübingen 72076, Germany
| | - Barbara Vona
- Department of Otolaryngology - Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, Tübingen 72076, Germany
| | - Firdous Abdulwahad
- Department of Translational Genomics, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Translational Genomics, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Inna S Povolotskaya
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Victoria Y Voinova
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
- Mental Health Research Center, Moscow 107076, Russia
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | | | - Fowzan S Alkuraya
- Department of Translational Genomics, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children’s Hospital, Seattle, WA 98195, USA
| | - Majid Alfadhel
- Genetics and Precision Medicine Department, King Abdullah Specialized Children's Hospital (KASCH), King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNG-HA), Riyadh, Saudi Arabia
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, King AbdulAziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany
- Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Pasquale Striano
- IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | | | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Yvonne Hilhorst-Hofstee
- Department of Clinical Genetics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
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11
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Liu J, Hu D, Zhang Z, Tang F, Yan Y, Ma Y. Autosomal dominant lateral temporal epilepsy in a family exhibiting a rare heterozygous mutation and deletion in the leucine-rich glioma inactivated 1 gene. Neurosci Lett 2022; 782:136698. [PMID: 35643238 DOI: 10.1016/j.neulet.2022.136698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 05/08/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022]
Abstract
Autosomal dominant lateral temporal epilepsy (ADLTE) is an inherited syndrome caused by mutations in the leucine-rich glioma inactivated 1 (LGI1) gene. In a family with six ADLTE patients spanning four generations, our linkage and exome sequencing investigations revealed a rare frameshift heterozygous mutation in LGI1 (c.1494del(p.Phe498LeufsTer15)). Gene cloning methods were used to create plasmids with wild-type and mutant LGI1 alleles. Through transfection of HEK293 cells and primary neurons, they were utilized to assess the subcellular location of wild-type and mutant LGI1. Moreover, the plasmid-transfected primary neurons were analyzed for neuronal complexity and density of dendritic spines. According to our results. the mutation decreased LGI1 secretion in transfected HEK293 cells. In primary neurons, mutant LGI1 affected neuronal polarity and complexity. Our findings have broadened the phenotypic spectrum of LGI1 mutations and provided evidence regarding the pathogenicity of this mutation. In addition, we discovered new information about the role of LGI1 in the development of temporal lobe epilepsy, along with a possible link between neuronal polarity disorder and ADLTE.
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Affiliation(s)
- Jie Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Danmei Hu
- Department of Neurology, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan 030032, China
| | - Zhijuan Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Fenglin Tang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yin Yan
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yuanlin Ma
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China.
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12
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Zhang W, Ye F, Pang N, Kessi M, Xiong J, Chen S, Peng J, Yang L, Yin F. Restoration of Sarco/Endoplasmic Reticulum Ca 2+-ATPase Activity Functions as a Pivotal Therapeutic Target of Anti-Glutamate-Induced Excitotoxicity to Attenuate Endoplasmic Reticulum Ca 2+ Depletion. Front Pharmacol 2022; 13:877175. [PMID: 35517826 PMCID: PMC9065279 DOI: 10.3389/fphar.2022.877175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Glutamate-induced excitotoxicity is a pathological basis of many acute/chronic neurodegenerative diseases. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2b) is a membrane-embedded P-type ATPase pump that manages the translocation of calcium ions (Ca2+) from cytosol into the lumen of the endoplasmic reticulum (ER) calcium stores. It participates in a wide range of biological functions in the central nervous system (CNS). However, the role of SERCA2b in glutamate-induced excitotoxicity and its mechanism must be elucidated. Herein, we demonstrate that SERCA2b mutants exacerbate the excitotoxicity of hypo-glutamate stimulation on HT22 cells. In this study, SERCA2b mutants accelerated Ca2+ depletion through loss-of-function (reduced pumping capacity) or gain-of-function (acquired leakage), resulting in ER stress. In addition, the occurrence of ER Ca2+ depletion increased mitochondria-associated membrane formation, which led to mitochondrial Ca2+ overload and dysfunction. Moreover, the enhancement of SERCA2b pumping capacity or inhibition of Ca2+ leakage attenuated Ca2+ depletion and impeded excitotoxicity in response to hypo-glutamate stimulation. In conclusion, SERCA2b mutants exacerbate ER Ca2+-depletion-mediated excitotoxicity in glutamate-sensitive HT22 cells. The mechanism of disruption is mainly related to the heterogeneity of SERCA2b mutation sites. Stabilization of SRECA2b function is a critical therapeutic approach against glutamate-induced excitotoxicity. These data will expand understanding of organelle regulatory networks and facilitate the discovery and creation of drugs against excitatory/inhibitory imbalance in the CNS.
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Affiliation(s)
- Wen Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Fanghua Ye
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China.,Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Shimeng Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Li Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China.,Clinical Research Center for Children Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
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13
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Disruption of the Ubiquitin-Proteasome System and Elevated Endoplasmic Reticulum Stress in Epilepsy. Biomedicines 2022; 10:biomedicines10030647. [PMID: 35327449 PMCID: PMC8945847 DOI: 10.3390/biomedicines10030647] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/05/2022] [Accepted: 03/07/2022] [Indexed: 02/06/2023] Open
Abstract
The epilepsies are a broad group of conditions characterized by repeated seizures, and together are one of the most common neurological disorders. Additionally, epilepsy is comorbid with many neurological disorders, including lysosomal storage diseases, syndromic intellectual disability, and autism spectrum disorder. Despite the prevalence, treatments are still unsatisfactory: approximately 30% of epileptic patients do not adequately respond to existing therapeutics, which primarily target ion channels. Therefore, new therapeutic approaches are needed. Disturbed proteostasis is an emerging mechanism in epilepsy, with profound effects on neuronal health and function. Proteostasis, the dynamic balance of protein synthesis and degradation, can be directly disrupted by epilepsy-associated mutations in various components of the ubiquitin-proteasome system (UPS), or impairments can be secondary to seizure activity or misfolded proteins. Endoplasmic reticulum (ER) stress can arise from failed proteostasis and result in neuronal death. In light of this, several treatment modalities that modify components of proteostasis have shown promise in the management of neurological disorders. These include chemical chaperones to assist proper folding of proteins, inhibitors of overly active protein degradation, and enhancers of endogenous proteolytic pathways, such as the UPS. This review summarizes recent work on the pathomechanisms of abnormal protein folding and degradation in epilepsy, as well as treatment developments targeting this area.
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14
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Zimmern V, Minassian B, Korff C. A Review of Targeted Therapies for Monogenic Epilepsy Syndromes. Front Neurol 2022; 13:829116. [PMID: 35250833 PMCID: PMC8891748 DOI: 10.3389/fneur.2022.829116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/13/2022] [Indexed: 11/15/2022] Open
Abstract
Genetic sequencing technologies have led to an increase in the identification and characterization of monogenic epilepsy syndromes. This increase has, in turn, generated strong interest in developing “precision therapies” based on the unique molecular genetics of a given monogenic epilepsy syndrome. These therapies include diets, vitamins, cell-signaling regulators, ion channel modulators, repurposed medications, molecular chaperones, and gene therapies. In this review, we evaluate these therapies from the perspective of their clinical validity and discuss the future of these therapies for individual syndromes.
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Affiliation(s)
- Vincent Zimmern
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
- *Correspondence: Vincent Zimmern
| | - Berge Minassian
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
| | - Christian Korff
- Pediatric Neurology Unit, University Hospitals, Geneva, Switzerland
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15
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Teng X, Hu P, Chen Y, Zang Y, Ye X, Ou J, Chen G, Shi YS. A novel
Lgi1
mutation causes white matter abnormalities and impairs motor coordination in mice. FASEB J 2022; 36:e22212. [DOI: 10.1096/fj.202101652r] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 01/18/2022] [Accepted: 02/03/2022] [Indexed: 12/22/2022]
Affiliation(s)
- Xiao‐Yu Teng
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
| | - Ping Hu
- Department of Prenatal Diagnosis State Key Laboratory of Reproductive Medicine Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital Nanjing China
| | - Yangyang Chen
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
| | - Yanyu Zang
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
| | - Xiaolian Ye
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
| | - Jingmin Ou
- Department of General Surgery Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine Shanghai China
| | - Guiquan Chen
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
| | - Yun Stone Shi
- Minister of Education Key Laboratory of Model Animal for Disease Study Model Animal Research Center, Medical School Nanjing University Nanjing China
- State Key Laboratory of Pharmaceutical Biotechnology Department of Neurology Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing University Nanjing China
- Institute for Brain Sciences Nanjing University Nanjing China
- Chemistry and Biomedicine Innovation Center Nanjing University Nanjing China
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16
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Liu C, Qiao XZ, Wei ZH, Cao M, Wu ZY, Deng YC. Molecular typing of familial temporal lobe epilepsy. World J Psychiatry 2022; 12:98-107. [PMID: 35111581 PMCID: PMC8783165 DOI: 10.5498/wjp.v12.i1.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 09/25/2021] [Accepted: 12/02/2021] [Indexed: 02/06/2023] Open
Abstract
The pathogenesis of temporal lobe epilepsy (TLE) was originally considered to be acquired. However, some reports showed that TLE was clustered in some families, indicating a genetic etiology. With the popularity of genetic testing technology, eleven different types of familial TLE (FTLE), including ETL1-ETL11, have been reported, of which ETL9-ETL11 had not yet been included in the OMIM database. These types of FTLE were caused by different genes/Loci and had distinct characteristics. ETL1, ETL7 and ETL10 were characterized by auditory, visual and aphasia seizures, leading to the diagnosis of familial lateral TLE. ETL2, ETL3 and ETL6 showed prominent autonomic symptom and automatism with or without hippocampal abnormalities, indicating a mesial temporal origin. Febrile seizures were common in FTLEs such as ETL2, ETL5, ETL6 and ETL11. ETL4 was diagnosed as occipitotemporal lobe epilepsy with a high incidence of migraine and visual aura. Considering the diversity and complexity of the symptoms of TLE, neurologists enquiring about the family history of epilepsy should ask whether the relatives of the proband had experienced unnoticeable seizures and whether there is a family history of other neurological diseases carefully. Most FTLE patients had a good prognosis with or without anti-seizure medication treatment, with the exception of patients with heterozygous mutations of the CPA6 gene. The pathogenic mechanism was diverse among these genes and spans disturbances of neuron development, differentiation and synaptic signaling. In this article, we describe the research progress on eleven different types of FTLE. The precise molecular typing of FTLE would facilitate the diagnosis and treatment of FTLE and genetic counseling for this disorder.
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Affiliation(s)
- Chao Liu
- Department of Neurology, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, Shaanxi Province, China
| | - Xiao-Zhi Qiao
- Department of Neurology, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, Shaanxi Province, China
| | - Zi-Han Wei
- Department of Neurology, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, Shaanxi Province, China
| | - Mi Cao
- Department of Neurology, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, Shaanxi Province, China
| | - Zhen-Yu Wu
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, School of Basic Medicine, Air Force Medical University, Xi'an 710032, Shaanxi Province, China
| | - Yan-Chun Deng
- Department of Neurology, The First Affiliated Hospital of Air Force Medical University, Xi'an 710032, Shaanxi Province, China
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17
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Baudin P, Cousyn L, Navarro V. The LGI1 protein: molecular structure, physiological functions and disruption-related seizures. Cell Mol Life Sci 2021; 79:16. [PMID: 34967933 PMCID: PMC11072701 DOI: 10.1007/s00018-021-04088-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 01/16/2023]
Abstract
Leucine-rich, glioma inactivated 1 (LGI1) is a secreted glycoprotein, mainly expressed in the brain, and involved in central nervous system development and physiology. Mutations of LGI1 have been linked to autosomal dominant lateral temporal lobe epilepsy (ADLTE). Recently auto-antibodies against LGI1 have been described as the basis for an autoimmune encephalitis, associated with specific motor and limbic epileptic seizures. It is the second most common cause of autoimmune encephalitis. This review presents details on the molecular structure, expression and physiological functions of LGI1, and examines how their disruption underlies human pathologies. Knock-down of LGI1 in rodents reveals that this protein is necessary for normal brain development. In mature brains, LGI1 is associated with Kv1 channels and AMPA receptors, via domain-specific interaction with membrane anchoring proteins and contributes to regulation of the expression and function of these channels. Loss of function, due to mutations or autoantibodies, of this key protein in the control of neuronal activity is a common feature in the genesis of epileptic seizures in ADLTE and anti-LGI1 autoimmune encephalitis.
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Affiliation(s)
- Paul Baudin
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Louis Cousyn
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
- AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Vincent Navarro
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France.
- AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France.
- AP-HP, Center of Reference for Rare Epilepsies, Pitié-Salpêtrière Hospital, 47-83 Boulevard de l'Hôpital, 75013, Paris, France.
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18
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Yokoi N, Fukata Y, Okatsu K, Yamagata A, Liu Y, Sanbo M, Miyazaki Y, Goto T, Abe M, Kassai H, Sakimura K, Meijer D, Hirabayashi M, Fukai S, Fukata M. 14-3-3 proteins stabilize LGI1-ADAM22 levels to regulate seizure thresholds in mice. Cell Rep 2021; 37:110107. [PMID: 34910912 DOI: 10.1016/j.celrep.2021.110107] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/08/2021] [Accepted: 11/16/2021] [Indexed: 01/17/2023] Open
Abstract
What percentage of the protein function is required to prevent disease symptoms is a fundamental question in genetic disorders. Decreased transsynaptic LGI1-ADAM22 protein complexes, because of their mutations or autoantibodies, cause epilepsy and amnesia. However, it remains unclear how LGI1-ADAM22 levels are regulated and how much LGI1-ADAM22 function is required. Here, by genetic and structural analysis, we demonstrate that quantitative dual phosphorylation of ADAM22 by protein kinase A (PKA) mediates high-affinity binding of ADAM22 to dimerized 14-3-3. This interaction protects LGI1-ADAM22 from endocytosis-dependent degradation. Accordingly, forskolin-induced PKA activation increases ADAM22 levels. Leveraging a series of ADAM22 and LGI1 hypomorphic mice, we find that ∼50% of LGI1 and ∼10% of ADAM22 levels are sufficient to prevent lethal epilepsy. Furthermore, ADAM22 function is required in excitatory and inhibitory neurons. These results suggest strategies to increase LGI1-ADAM22 complexes over the required levels by targeting PKA or 14-3-3 for epilepsy treatment.
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Affiliation(s)
- Norihiko Yokoi
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan.
| | - Kei Okatsu
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Atsushi Yamagata
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Yan Liu
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Makoto Sanbo
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Yuri Miyazaki
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Teppei Goto
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Hidetoshi Kassai
- Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Dies Meijer
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Masumi Hirabayashi
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan; Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Shuya Fukai
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan.
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19
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Hu P, Wu D, Zang YY, Wang Y, Zhou YP, Qiao F, Teng XY, Chen J, Li QQ, Sun JH, Liu T, Feng HY, Zhou QG, Shi YS, Xu Z. A novel LGI1 mutation causing autosomal dominant lateral temporal lobe epilepsy confirmed by a precise knock-in mouse model. CNS Neurosci Ther 2021; 28:237-246. [PMID: 34767694 PMCID: PMC8739050 DOI: 10.1111/cns.13761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 10/20/2021] [Accepted: 10/25/2021] [Indexed: 12/30/2022] Open
Abstract
AIMS This study aimed to explore the pathomechanism of a mutation on the leucine-rich glioma inactivated 1 gene (LGI1) identified in a family having autosomal dominant lateral temporal lobe epilepsy (ADLTE), using a precise knock-in mouse model. METHODS AND RESULTS A novel LGI1 mutation, c.152A>G; p. Asp51Gly, was identified by whole exome sequencing in a Chinese family with ADLTE. The pathomechanism of the mutation was explored by generating Lgi1D51G knock-in mice that precisely phenocopied the epileptic symptoms of human patients. The Lgi1D51G / D51G mice showed spontaneous recurrent generalized seizures and premature death. The Lgi1D51G /+ mice had partial epilepsy, with half of them displaying epileptiform discharges on electroencephalography. They also showed enhanced sensitivity to the convulsant agent pentylenetetrazole. Mechanistically, the secretion of Lgi1 was impaired in the brain of the D51G knock-in mice and the protein level was drastically reduced. Moreover, the antiepileptic drugs, carbamazepine, oxcarbazepine, and sodium valproate, could prolong the survival time of Lgi1D51G / D51G mice, and oxcarbazepine appeared to be the most effective. CONCLUSIONS We identified a novel epilepsy-causing mutation of LGI1 in humans. The Lgi1D51G /+ mouse model, precisely phenocopying epileptic symptoms of human patients, could be a useful tool in future studies on the pathogenesis and potential therapies for epilepsy.
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Affiliation(s)
- Ping Hu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health care Hospital, Nanjing, China
| | - Dan Wu
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Yan-Yu Zang
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Yan Wang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health care Hospital, Nanjing, China
| | - Ya-Ping Zhou
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Fengchang Qiao
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health care Hospital, Nanjing, China
| | - Xiao-Yu Teng
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Jiang Chen
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Qing-Qing Li
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Jia-Hui Sun
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - TingTing Liu
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China
| | - Hao-Yang Feng
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health care Hospital, Nanjing, China
| | - Qi-Gang Zhou
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Yun Stone Shi
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, National Resource for Mutant Mice, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, China.,Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Zhengfeng Xu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health care Hospital, Nanjing, China
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20
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Fels E, Muñiz-Castrillo S, Vogrig A, Joubert B, Honnorat J, Pascual O. Role of LGI1 protein in synaptic transmission: From physiology to pathology. Neurobiol Dis 2021; 160:105537. [PMID: 34695575 DOI: 10.1016/j.nbd.2021.105537] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/17/2023] Open
Abstract
Leucine-Rich Glioma Inactivated protein 1 (LGI1) is a secreted neuronal protein highly expressed in the central nervous system and high amount are found in the hippocampus. An alteration of its function has been described in few families of patients with autosomal dominant temporal lobe epilepsy (ADLTE) or with autoimmune limbic encephalitis (LE), both characterized by epileptic seizures. Studies have shown that LGI1 plays an essential role during development, but also in neuronal excitability through an action on voltage-gated potassium Kv1.1 channels, and in synaptic transmission by regulating the surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-R). Over the last decade, a growing number of studies investigating LGI1 functions have been published. They aimed to improve the understanding of LGI1 function in the regulation of neuronal networks using different animal and cellular models. LGI1 appears to be a major actor of synaptic regulation by modulating trans-synaptically pre- and post-synaptic proteins. In this review, we will focus on LGI1 binding partners, "A Disintegrin And Metalloprotease (ADAM) 22 and 23", the complex they form at the synapse, and will discuss the effects of LGI1 on neuronal excitability and synaptic transmission in physiological and pathological conditions. Finally, we will highlight new insights regarding N-terminal Leucine-Rich Repeat (LRR) domain and C-terminal Epitempin repeat (EPTP) domain and their potentially distinct role in LGI1 function.
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Affiliation(s)
- Elodie Fels
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France
| | - Sergio Muñiz-Castrillo
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Alberto Vogrig
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Bastien Joubert
- Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Jérôme Honnorat
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France.
| | - Olivier Pascual
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France.
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21
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Fukata Y, Hirano Y, Miyazaki Y, Yokoi N, Fukata M. Trans-synaptic LGI1–ADAM22–MAGUK in AMPA and NMDA receptor regulation. Neuropharmacology 2021; 194:108628. [DOI: 10.1016/j.neuropharm.2021.108628] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 02/06/2023]
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22
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Booth DG, Kozar N, Bradley S, Meijer D. Characterizing the molecular etiology of arthrogryposis multiplex congenita in patients with LGI4 mutations. Glia 2021; 69:2605-2617. [PMID: 34288120 DOI: 10.1002/glia.24061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/07/2021] [Accepted: 07/09/2021] [Indexed: 11/05/2022]
Abstract
Disruption of axon-glia interactions in the peripheral nervous system has emerged as a major cause of arthrogryposis multiplex congenita (AMC), a condition characterized by multiple congenital postural abnormalities involving the major joints. Several genes crucially important to the biology of Schwann cells have now been implicated with AMC. One such gene is LGI4 which encodes a secreted glycoprotein. LGI4 is expressed and secreted by Schwann cells and binds its receptor ADAM22 on the axonal membrane to drive myelination. Homozygous mutations in LGI4 or ADAM22 results in severe congenital hypomyelination and joint contractures in mice. Recently bi-allelic LGI4 loss of function mutations has been described in three unrelated families with severe AMC. Two individuals in a fourth, non-consanguineous family were found to be compound heterozygous for two LGI4 missense mutations. It is not known how these missense mutations affect the biology of LGI4. Here we investigated whether these missense mutations affected the secretion of the protein, its ADAM22 binding capacity, or its myelination-promoting function. We demonstrate that the mutations largely affect the progression of the mutant protein through the endomembrane system resulting in severely reduced expression. Importantly, binding to ADAM22 and myelination-promoting activity appear largely unaffected, suggesting that treatment with chemical chaperones to improve secretion of the mutant proteins might prove beneficial.
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Affiliation(s)
- Daniel G Booth
- Centre for Discovery Brain Sciences and MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Nina Kozar
- Centre for Discovery Brain Sciences and MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen Bradley
- Centre for Discovery Brain Sciences and MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Dies Meijer
- Centre for Discovery Brain Sciences and MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, United Kingdom
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23
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LGI1-ADAM22-MAGUK configures transsynaptic nanoalignment for synaptic transmission and epilepsy prevention. Proc Natl Acad Sci U S A 2021; 118:2022580118. [PMID: 33397806 PMCID: PMC7826393 DOI: 10.1073/pnas.2022580118] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
This study addresses a fundamental question in neuroscience, namely how does the presynaptic component of the synapse precisely align with the postsynaptic component? This is essential for the proper transmission of signals across the synapse. This paper focuses on a set of transsynaptic, epilepsy-related proteins that are essential for this alignment. We show that the LGI1–ADAM22–MAGUK complex is a key player in the nanoarchitecture of the synapse, such that the release site is directly apposed to the nanocluster of glutamate receptors. Physiological functioning and homeostasis of the brain rely on finely tuned synaptic transmission, which involves nanoscale alignment between presynaptic neurotransmitter-release machinery and postsynaptic receptors. However, the molecular identity and physiological significance of transsynaptic nanoalignment remain incompletely understood. Here, we report that epilepsy gene products, a secreted protein LGI1 and its receptor ADAM22, govern transsynaptic nanoalignment to prevent epilepsy. We found that LGI1–ADAM22 instructs PSD-95 family membrane-associated guanylate kinases (MAGUKs) to organize transsynaptic protein networks, including NMDA/AMPA receptors, Kv1 channels, and LRRTM4–Neurexin adhesion molecules. Adam22ΔC5/ΔC5 knock-in mice devoid of the ADAM22–MAGUK interaction display lethal epilepsy of hippocampal origin, representing the mouse model for ADAM22-related epileptic encephalopathy. This model shows less-condensed PSD-95 nanodomains, disordered transsynaptic nanoalignment, and decreased excitatory synaptic transmission in the hippocampus. Strikingly, without ADAM22 binding, PSD-95 cannot potentiate AMPA receptor-mediated synaptic transmission. Furthermore, forced coexpression of ADAM22 and PSD-95 reconstitutes nano-condensates in nonneuronal cells. Collectively, this study reveals LGI1–ADAM22–MAGUK as an essential component of transsynaptic nanoarchitecture for precise synaptic transmission and epilepsy prevention.
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24
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Syrbe S. Präzisionsmedizin für genetische Epilepsien – am Anfang des Weges? ZEITSCHRIFT FÜR EPILEPTOLOGIE 2021. [DOI: 10.1007/s10309-021-00409-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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25
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Fu J, Tao T, Li Z, Chen Y, Li J, Peng L. The roles of ER stress in epilepsy: Molecular mechanisms and therapeutic implications. Biomed Pharmacother 2020; 131:110658. [PMID: 32841895 DOI: 10.1016/j.biopha.2020.110658] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsies are a diverse group of neurological disorders, which are characterized by spontaneous recurrent seizures. Although a wide range of pathogenic mechanisms such as alterations in ion channels, inflammation and neuronal loss have been reported to be implicated in the epileptogenesis, the underlying pathogenesis of epilepsy remains unclear currently. Endoplasmic reticulum (ER) stress is regarded as a condition that unfolded or misfolded proteins accumulate in the ER lumen. Excessive or prolonged ER stress causes the activation of the unfolded protein response (UPR) to buffer ER stress and restore ER homeostasis. Increasing evidence has indicated dysregulated ER stress during epileptogenesis, which may participate in various pathological processes associated with epilepsy. In this present review, we summarized recent advances in the involvement of ER stress in the pathogenesis of epilepsy. Additionally, the antiepileptic and neuroprotective effects of interventions targeting ER stress were also discussed.
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Affiliation(s)
- Jie Fu
- Department of Neurology, the Affiliated Hospital of Southwest Medical University. Taiping Street, Jiangyang District, Luzhou, 646000, China; Department of Neurology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China
| | - Tao Tao
- Department of Neurology, the Affiliated Hospital of Southwest Medical University. Taiping Street, Jiangyang District, Luzhou, 646000, China
| | - Zuoxiao Li
- Department of Neurology, the Affiliated Hospital of Southwest Medical University. Taiping Street, Jiangyang District, Luzhou, 646000, China
| | - Yangmei Chen
- Department of Neurology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China
| | - Jinglun Li
- Department of Neurology, the Affiliated Hospital of Southwest Medical University. Taiping Street, Jiangyang District, Luzhou, 646000, China.
| | - Lilei Peng
- Department of Neurosurgery, the Affiliated Hospital of Southwest Medical University. Taiping Street, Jiangyang District, Luzhou, 646000, China.
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26
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Yamagata A, Fukai S. Insights into the mechanisms of epilepsy from structural biology of LGI1-ADAM22. Cell Mol Life Sci 2020; 77:267-274. [PMID: 31432233 PMCID: PMC11104983 DOI: 10.1007/s00018-019-03269-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/05/2019] [Accepted: 08/09/2019] [Indexed: 01/05/2023]
Abstract
Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1-ADAM22.
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Affiliation(s)
- Atsushi Yamagata
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
- Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan.
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa, 230-0045, Japan.
| | - Shuya Fukai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
- Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan.
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27
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Matsushima N, Takatsuka S, Miyashita H, Kretsinger RH. Leucine Rich Repeat Proteins: Sequences, Mutations, Structures and Diseases. Protein Pept Lett 2019; 26:108-131. [PMID: 30526451 DOI: 10.2174/0929866526666181208170027] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
Abstract
Mutations in the genes encoding Leucine Rich Repeat (LRR) containing proteins are associated with over sixty human diseases; these include high myopia, mitochondrial encephalomyopathy, and Crohn's disease. These mutations occur frequently within the LRR domains and within the regions that shield the hydrophobic core of the LRR domain. The amino acid sequences of fifty-five LRR proteins have been published. They include Nod-Like Receptors (NLRs) such as NLRP1, NLRP3, NLRP14, and Nod-2, Small Leucine Rich Repeat Proteoglycans (SLRPs) such as keratocan, lumican, fibromodulin, PRELP, biglycan, and nyctalopin, and F-box/LRR-repeat proteins such as FBXL2, FBXL4, and FBXL12. For example, 363 missense mutations have been identified. Replacement of arginine, proline, or cysteine by another amino acid, or the reverse, is frequently observed. The diverse effects of the mutations are discussed based on the known structures of LRR proteins. These mutations influence protein folding, aggregation, oligomerization, stability, protein-ligand interactions, disulfide bond formation, and glycosylation. Most of the mutations cause loss of function and a few, gain of function.
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Affiliation(s)
- Norio Matsushima
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan.,Institute of Tandem Repeats, Noboribetsu 059-0464, Japan
| | - Shintaro Takatsuka
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Hiroki Miyashita
- Institute of Tandem Repeats, Noboribetsu 059-0464, Japan.,Hokubu Rinsho Co., Ltd, Sapporo 060-0061, Japan
| | - Robert H Kretsinger
- Department of Biology, University of Virginia, Charlottesville, VA 22904, United States
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Fu J, Peng L, Wang W, He H, Zeng S, Chen TC, Chen Y. Sodium Valproate Reduces Neuronal Apoptosis in Acute Pentylenetetrzole-Induced Seizures via Inhibiting ER Stress. Neurochem Res 2019; 44:2517-2526. [DOI: 10.1007/s11064-019-02870-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/10/2019] [Accepted: 09/05/2019] [Indexed: 02/06/2023]
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Hsia HE, Tüshaus J, Brummer T, Zheng Y, Scilabra SD, Lichtenthaler SF. Functions of 'A disintegrin and metalloproteases (ADAMs)' in the mammalian nervous system. Cell Mol Life Sci 2019; 76:3055-3081. [PMID: 31236626 PMCID: PMC11105368 DOI: 10.1007/s00018-019-03173-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 05/22/2019] [Accepted: 05/29/2019] [Indexed: 12/31/2022]
Abstract
'A disintegrin and metalloproteases' (ADAMs) are a family of transmembrane proteins with diverse functions in multicellular organisms. About half of the ADAMs are active metalloproteases and cleave numerous cell surface proteins, including growth factors, receptors, cytokines and cell adhesion proteins. The other ADAMs have no catalytic activity and function as adhesion proteins or receptors. Some ADAMs are ubiquitously expressed, others are expressed tissue specifically. This review highlights functions of ADAMs in the mammalian nervous system, including their links to diseases. The non-proteolytic ADAM11, ADAM22 and ADAM23 have key functions in neural development, myelination and synaptic transmission and are linked to epilepsy. Among the proteolytic ADAMs, ADAM10 is the best characterized one due to its substrates Notch and amyloid precursor protein, where cleavage is required for nervous system development or linked to Alzheimer's disease (AD), respectively. Recent work demonstrates that ADAM10 has additional substrates and functions in the nervous system and its substrate selectivity may be regulated by tetraspanins. New roles for other proteolytic ADAMs in the nervous system are also emerging. For example, ADAM8 and ADAM17 are involved in neuroinflammation. ADAM17 additionally regulates neurite outgrowth and myelination and its activity is controlled by iRhoms. ADAM19 and ADAM21 function in regenerative processes upon neuronal injury. Several ADAMs, including ADAM9, ADAM10, ADAM15 and ADAM30, are potential drug targets for AD. Taken together, this review summarizes recent progress concerning substrates and functions of ADAMs in the nervous system and their use as drug targets for neurological and psychiatric diseases.
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Affiliation(s)
- Hung-En Hsia
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany
| | - Johanna Tüshaus
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany
| | - Tobias Brummer
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany
| | - Yuanpeng Zheng
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany
| | - Simone D Scilabra
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany
- Fondazione Ri.MED, Department of Research, IRCCS-ISMETT, via Tricomi 5, 90127, Palermo, Italy
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Strasse 17, 81377, Munich, Germany.
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Science, Technische Universität München, 81675, Munich, Germany.
- Munich Center for Systems Neurology (SyNergy), Munich, Germany.
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Liu F, Du C, Tian X, Ma Y, Zhao B, Yan Y, Lin Z, Lin P, Zhou R, Wang X. A novel LGI1 missense mutation causes dysfunction in cortical neuronal migration and seizures. Brain Res 2019; 1721:146332. [PMID: 31301272 DOI: 10.1016/j.brainres.2019.146332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/23/2019] [Accepted: 07/09/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND To explore the causative genes and pathogenesis of autosomal dominant partial epilepsy with auditory features in a large Chinese family that includes 7 patients over four generations. METHODS We used targeted exome sequencing and Sanger sequencing to validate the mutation. Zebrafish were used to explore the epileptic behavior caused by the mutation. Primary cortical neuronal culturing and in utero electroporation were used to observe the influences of the mutation on neuronal polarity and migration. RESULTS We report the identification of a novel missense mutation, c.128C > G (p. Pro43Arg), in exon 1 of LGI1. The heterozygous missense mutation, which cosegregated with the syndrome, was absent in 300 unrelated and matched-ancestor controls. The mutation inhibited the secretion of LGI1 and could not rescue the hyperactivity caused by lgi1a knockdown in zebrafish. In vitro, mutant LGI1 interrupts normal cell polarity. In agreement with these findings, dysfunctional cortical neuron migration was observed using in utero electroporation technology, which is reminiscent of the subtle structural changes in the lateral temporal region observed in the proband of this family. CONCLUSION Our findings enrich the spectrum of LGI1 mutations and support the pathogenicity of the mutation. Furthermore, additional information regarding the role of LGI1 in the development of temporal lobe epilepsy was elucidated, and a potential relationship was established between cortical neuronal migration dysfunction and autosomal dominant partial epilepsy with auditory features.
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Affiliation(s)
- Feng Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Chao Du
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Xin Tian
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yuanlin Ma
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Bei Zhao
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yin Yan
- Department of Neurology, The Ninth People's Hospital of Chongqing, Chongqing 400016, China
| | - Zijun Lin
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Peijia Lin
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Ruijiao Zhou
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Xuefeng Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China.
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31
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Huang GH, Chen K, Sun YY, Zhu L, Sun ZL, Feng DF. 4-Phenylbutyrate Ameliorates Anxiety Disorder by Inhibiting Endoplasmic Reticulum Stress after Diffuse Axonal Injury. J Neurotrauma 2019; 36:1856-1868. [PMID: 30582423 DOI: 10.1089/neu.2018.6048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Diffuse axonal injury (DAI) is accompanied frequently by adverse sequelae and psychiatric disorders, such as anxiety, leading to a decreased quality of life, social isolation, and poor outcomes in patients. The mechanisms regulating psychiatric disorders post-DAI are not well elucidated, however. Previous studies showed that endoplasmic reticulum (ER) stress functions as a pivotal factor in neurodegeneration disease. In this study, we showed that DAI can trigger ER stress and unfolded protein response (UPR) activation in both the acute and chronic periods, leading to cell death and anxiety disorder. Treatment with 4-phenylbutyrate (4-PBA) is able to inhibit the UPR and cell apoptosis and relieve the anxiety disorder in our DAI model. Later (14 days post-DAI) 4-PBA treatment, however, can restore only the related gene expression of ER stress and UPR but not the psychiatric disorder. Therefore, the early (5 min after DAI) administration of 4-PBA might be a therapeutic approach for blocking the ER stress/UPR-induced cell death and anxiety disorder after DAI.
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Affiliation(s)
- Guo-Hui Huang
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,2 Institute of Traumatic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kui Chen
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,2 Institute of Traumatic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi-Yu Sun
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,2 Institute of Traumatic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liang Zhu
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhao-Liang Sun
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dong-Fu Feng
- 1 Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,2 Institute of Traumatic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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32
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Yamagata A, Fukai S. Structural insights into leucine-rich repeat-containing synaptic cleft molecules. Curr Opin Struct Biol 2019; 54:68-77. [PMID: 30784960 DOI: 10.1016/j.sbi.2019.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 11/28/2018] [Accepted: 01/07/2019] [Indexed: 02/04/2023]
Abstract
Synapses are cell adhesion structures specialized for signal transmission between neurons. At the synapse, presynaptic and postsynaptic terminals of neurons are functionally connected but spatially separated and form a cleft. Membrane receptor-like cell adhesion molecules and secreted proteins in the synaptic cleft (synaptic cleft molecules) can mediate structural and functional linkages between the presynaptic and postsynaptic terminals for neural development or activity. A leucine-rich repeat (LRR) has been known as a typical structural motif for protein-protein interactions and plays important roles in intermolecular interactions mediated by synaptic cleft molecules. In this review, we summarize structural insights into LRR-containing synaptic cleft molecules from recent structural studies and discuss how they are linked to their downstream events.
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Affiliation(s)
- Atsushi Yamagata
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan; Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo 113-0032, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan.
| | - Shuya Fukai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan; Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo 113-0032, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan.
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33
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Esposito S, Principi N, Calabresi P, Rigante D. An evolving redefinition of autoimmune encephalitis. Autoimmun Rev 2018; 18:155-163. [PMID: 30572142 DOI: 10.1016/j.autrev.2018.08.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 08/18/2018] [Indexed: 12/13/2022]
Abstract
Autoimmune encephalitis encompasses a wide variety of protean pathologic processes associated with the presence of antibodies against neuronal intracellular proteins, synaptic receptors, ion channels and/or neuronal surface proteins. This type of encephalitis can also involve children with complex patterns of seizures and unexpected behavioural changes, which jeopardize their prompt recognition and treatment. Many epidemiological studies have shown that numerous immune-based forms of encephalitis can be encountered, almost surpassing the rate of postinfectious encephalitides. However, the overall exact prevalence of autoimmune encephalopathies remains underestimated, and the definition of diagnostic algorithms results muddled. The spectrum of neuropsychiatric manifestations in the pediatric population with autoimmune encephalitis is less clear than in adults, but the integration of clinical, immunological, electrophysiological and neuroradiological data is essential for a general approach to patients. In this review we report the most relevant data about both immunologic and clinical characteristics of the main autoimmune encephalitides recognized so far, with the aim of assisting clinicians in the differential diagnosis and favouring an early effective treatment. Correlations between phenotype and autoantibodies involved in the neurological damage of autoimmune encephalitis are largely unknown in the first years of life, because of the relatively small number of pediatric patients adequately studied. Future multicenter collaborative studies are needed to improve the diagnostic approach and tailor personalized therapies in the long-term.
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Affiliation(s)
- Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Perugia, Italy.
| | | | - Paolo Calabresi
- Neurology Clinic, Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
| | - Donato Rigante
- Institute of Pediatrics, Università Cattolica Sacro Cuore, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
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Jara O, Minogue PJ, Berthoud VM, Beyer EC. Chemical chaperone treatment improves levels and distributions of connexins in Cx50D47A mouse lenses. Exp Eye Res 2018; 175:192-198. [PMID: 29913165 DOI: 10.1016/j.exer.2018.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/10/2018] [Accepted: 06/14/2018] [Indexed: 01/29/2023]
Abstract
Mouse Cx50D47A and human Cx50D47N are non-functional connexin mutants that cause dominantly-inherited cataracts. In tissue culture expression experiments, they both exhibit impaired cellular trafficking and gap junction plaque formation. Lenses of mice expressing Cx50D47A have cataracts, reduced size, drastically decreased levels of connexin50, and less severely reduced levels of connexin46. The PERK-dependent pathway of the ER response to misfolded proteins is activated, and they have impaired differentiation with retained cellular organelles. Since treatments that enhance protein folding improve trafficking and plaque formation by Cx50D47N and other mutant connexins in vitro, and they are successful therapeutics for some other diseases caused by misfolded proteins, we tested the efficacy of the chemical chaperone, 4-phenylbutyrate (4-PBA) in cultured cells and mice expressing Cx50D47A. 4-PBA treatment increased the formation of Cx50D47A-containing plaques at appositional membranes of transiently transfected HeLa cells. Heterozygous Cx50D47A mice were treated with 4-PBA by addition to the drinking water and parenteral injection of pregnant mice (starting 10 days after pairing of males and females) and their pups. Lenses from 1-month-old mice were examined by darkfield illumination and immunofluorescence microscopy. Protein levels were determined by immunoblotting. Cataract size and density were not detectably different between the control and the 4-PBA-treated groups. Lens size was not increased following treatment. Levels of connexin46 and connexin50 were significantly increased in lenses of 4-PBA-treated mice compared with saline-treated animals. Immunofluorescence showed an increased abundance of connexin46 immunoreactivity and puncta. The ratio of phosphorylated to total EIF2α was not altered, and levels of organellar proteins were not significantly reduced, suggesting that the ER response to misfolded proteins and differentiation were not changed. Thus, treatment with 4-PBA improved critical pathological issues in these mice (low connexin and gap junction abundance), but the magnitude of this recovery (especially for Cx50) was inadequate to impact the reduced size or the opacification of Cx50D47A lenses.
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Affiliation(s)
- Oscar Jara
- Department of Pediatrics, University of Chicago, Chicago, IL, United States
| | - Peter J Minogue
- Department of Pediatrics, University of Chicago, Chicago, IL, United States
| | - Viviana M Berthoud
- Department of Pediatrics, University of Chicago, Chicago, IL, United States
| | - Eric C Beyer
- Department of Pediatrics, University of Chicago, Chicago, IL, United States.
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35
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Liu Y, Hou B, Zhang Y, Fan Y, Peng B, Liu W, Han S, Yin J, He X. Anticonvulsant agent DPP4 inhibitor sitagliptin downregulates CXCR3/RAGE pathway on seizure models. Exp Neurol 2018; 307:90-98. [PMID: 29885296 DOI: 10.1016/j.expneurol.2018.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/09/2018] [Accepted: 06/05/2018] [Indexed: 12/11/2022]
Abstract
Epilepsy is a common neurological disorder with a complex etiology. Our previous study demonstrated that dipeptidyl peptidase IV (DPP4) may be associated with the pathogenesis of epilepsy. However, whether the DPP4 inhibitor sitagliptin has an anticonvulsant effect and the underlying mechanism remain to be elucidated. In this study, we determined that sitagliptin remarkably attenuated the severity of seizures in a pentylenetetrazole (PTZ)-induced rat model. In addition, sitagliptin decreased epileptiform activity measured by electroencephalography (EEG) recordings and patch-clamp methods. Interestingly, sitagliptin pretreatment downregulated the RAGE-JAK2/STAT3 pathway and decreased the expression of CXCL4 and CXCR3. Moreover, CXCR3 knockdown decreased the expression of RAGE, JAK2 and STAT3 in cultured neurons, which suggests that CXCR3 is upstream of the RAGE-JAK2/STAT3 pathway. Altogether, our present data suggest that sitagliptin has an anticonvulsant effect, which might act via downregulation of the CXCL4/CXCR3 axis, followed by a decrease in RAGE and JAK2/STAT3 expression. Considering these effects, sitagliptin could be considered as a novel potential anticonvulsant drug.
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Affiliation(s)
- Yunli Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Baohua Hou
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yusong Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China; Department of Pathology, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yuanteng Fan
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Biwen Peng
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jun Yin
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
| | - Xiaohua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
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36
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Structural basis of epilepsy-related ligand-receptor complex LGI1-ADAM22. Nat Commun 2018; 9:1546. [PMID: 29670100 PMCID: PMC5906670 DOI: 10.1038/s41467-018-03947-w] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/23/2018] [Indexed: 01/17/2023] Open
Abstract
Epilepsy is a common brain disorder throughout history. Epilepsy-related ligand–receptor complex, LGI1–ADAM22, regulates synaptic transmission and has emerged as a determinant of brain excitability, as their mutations and acquired LGI1 autoantibodies cause epileptic disorders in human. Here, we report the crystal structure of human LGI1–ADAM22 complex, revealing a 2:2 heterotetrameric assembly. The hydrophobic pocket of the C-terminal epitempin-repeat (EPTP) domain of LGI1 binds to the metalloprotease-like domain of ADAM22. The N-terminal leucine-rich repeat and EPTP domains of LGI1 mediate the intermolecular LGI1–LGI1 interaction. A pathogenic R474Q mutation of LGI1, which does not exceptionally affect either the secretion or the ADAM22 binding, is located in the LGI1–LGI1 interface and disrupts the higher-order assembly of the LGI1–ADAM22 complex in vitro and in a mouse model for familial epilepsy. These studies support the notion that the LGI1–ADAM22 complex functions as the trans-synaptic machinery for precise synaptic transmission. LGI1 is an epilepsy-related gene that encodes a secreted neuronal protein. Here the authors present the crystal structure of LGI1 bound to its receptor ADAM22, which provides structural insights into epilepsy-causing LGI1 mutations and might facilitate the development of novel anti-epilepsy drugs.
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37
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Dazzo E, Rehberg K, Michelucci R, Passarelli D, Boniver C, Vianello Dri V, Striano P, Striano S, Pasterkamp RJ, Nobile C. Mutations in MICAL-1cause autosomal-dominant lateral temporal epilepsy. Ann Neurol 2018; 83:483-493. [PMID: 29394500 DOI: 10.1002/ana.25167] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Autosomal-dominant lateral temporal epilepsy (ADLTE) is a genetic focal epilepsy characterized by auditory symptoms. Two genes, LGI1 and RELN, encoding secreted proteins, are implicated in the etiology of ADLTE, but half of the affected families remain genetically unsolved, and the underlying molecular mechanisms are yet to be clarified. We aimed to identify additional genes causing ADLTE to better understand the genetic basis and molecular pathway underlying this epileptic disorder. METHODS A cohort of Italian ADLTE families was examined by whole exome sequencing combined with genome-wide single-nucleotide polymorphism-array linkage analysis. RESULTS We identified two ADLTE-causing variants in the MICAL-1 gene: a p.Gly150Ser substitution occurring in the enzymatically active monooxygenase (MO) domain and a p.Ala1065fs frameshift indel in the C-terminal domain, which inhibits the oxidoreductase activity of the MO domain. Each variant segregated with ADLTE in a single family. Examination of candidate variants in additional genes excluded their implication in ADLTE. In cell-based assays, both variants significantly increased MICAL-1 oxidoreductase activity and induced cell contraction in COS7 cells, which likely resulted from deregulation of F-actin dynamics. INTERPRETATION MICAL-1 oxidoreductase activity induces disassembly of actin filaments, thereby regulating the organization of the actin cytoskeleton in developing and adult neurons and in other cell types. This suggests that dysregulation of the actin cytoskeleton dynamics is a likely mechanism by which MICAL-1 pathogenic variants lead to ADLTE. Ann Neurol 2018;83:483-493.
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Affiliation(s)
- Emanuela Dazzo
- CNR-Neuroscience Institute, Section of Padua, Padova, Italy
| | - Kati Rehberg
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, UMC Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Roberto Michelucci
- IRCCS-Institute of Neurological Sciences of Bologna, Unit of Neurology, Bellaria Hospital, Bologna, Italy
| | | | - Clementina Boniver
- Clinical Neurophysiology, Department of Pediatrics, University of Padua, Padova, Italy
| | - Valeria Vianello Dri
- APSS Trento, Mental Health Department, Child and Adolescent Neuropsichiatry 1, Trento, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, "G. Gaslini" Institute, Genova, Italy
| | - Salvatore Striano
- Department of Neurological Sciences, Federico II University, Napoli, Italy
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, UMC Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Carlo Nobile
- CNR-Neuroscience Institute, Section of Padua, Padova, Italy.,Department of Biomedical Sciences, University of Padua, Padova, Italy
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Omachi K, Kamura M, Teramoto K, Kojima H, Yokota T, Kaseda S, Kuwazuru J, Fukuda R, Koyama K, Matsuyama S, Motomura K, Shuto T, Suico MA, Kai H. A Split-Luciferase-Based Trimer Formation Assay as a High-throughput Screening Platform for Therapeutics in Alport Syndrome. Cell Chem Biol 2018. [PMID: 29526710 DOI: 10.1016/j.chembiol.2018.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alport syndrome is a hereditary glomerular disease caused by mutation in type IV collagen α3-α5 chains (α3-α5(IV)), which disrupts trimerization, leading to glomerular basement membrane degeneration. Correcting the trimerization of α3/α4/α5 chain is a feasible therapeutic approach, but is hindered by lack of information on the regulation of intracellular α(IV) chain and the absence of high-throughput screening (HTS) platforms to assess α345(IV) trimer formation. Here, we developed sets of split NanoLuc-fusion α345(IV) proteins to monitor α345(IV) trimerization of wild-type and clinically associated mutant α5(IV). The α345(IV) trimer assay, which satisfied the acceptance criteria for HTS, enabled the characterization of intracellular- and secretion-dependent defects of mutant α5(IV). Small interfering RNA-based and chemical screening targeting the ER identified several chemical chaperones that have potential to promote α345(IV) trimer formation. This split luciferase-based trimer formation assay is a functional HTS platform that realizes the feasibility of targeting α345(IV) trimers to treat Alport syndrome.
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Affiliation(s)
- Kohei Omachi
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Misato Kamura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Keisuke Teramoto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Haruka Kojima
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Tsubasa Yokota
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Shota Kaseda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Jun Kuwazuru
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Ryosuke Fukuda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Kosuke Koyama
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Shingo Matsuyama
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Keishi Motomura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Tsuyoshi Shuto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan.
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan.
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Celecoxib Ameliorates Seizure Susceptibility in Autosomal Dominant Lateral Temporal Epilepsy. J Neurosci 2018; 38:3346-3357. [PMID: 29491011 DOI: 10.1523/jneurosci.3245-17.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/24/2018] [Accepted: 02/20/2018] [Indexed: 12/11/2022] Open
Abstract
Autosomal dominant lateral temporal epilepsy (ADLTE) is an inherited syndrome caused by mutations in the leucine-rich glioma inactivated 1 (LGI1) gene. It is known that glutamatergic transmission is altered in LGI1 mutant mice, and seizures can be reduced by restoring LGI1 function. Yet, the mechanism underlying ADLTE is unclear. Here, we propose that seizures in male LGI1-/- mice are due to nonsynaptic epileptiform activity in cortical neurons. We examined the intrinsic excitability of pyramidal neurons in the temporal cortex of male LGI1-/- mice and found that the voltage-gated K+ channel Kv1.2 was significantly downregulated. We also found that cytosolic phospholipase A2 (cPLA2)-cyclooxygenase 2 (Cox2) signaling was enhanced in LGI1-/- mice. Interestingly, Cox2 inhibition effectively restored the dysregulated Kv1.2 and reduced the intrinsic excitability of pyramidal neurons. Moreover, in vivo injection of celecoxib, an FDA-approved nonsteroidal anti-inflammatory drug, rescued the defective Kv1.2 (an ∼1.9-fold increase), thereby alleviating the seizure susceptibility and extending the life of LGI1-/- mice by 5 d. In summary, we conclude that LGI1 deficiency dysregulates cPLA2-Cox2 signaling to cause hyperexcitability of cortical pyramidal neurons, and celecoxib is a potential agent to manage human ADLTE.SIGNIFICANCE STATEMENT Haploinsufficiency of the leucine-rich glioma inactivated 1 (LGI1) gene is the major pathogenic basis for ADLTE, an inherited syndrome with no cure to date. Existing studies suggest that altered glutamatergic transmission in the hippocampus causes this disease, but the data are paradoxical. We demonstrate that the loss of LGI1 decreases Kv1.2 expression, enhances intrinsic excitability, and thereby causes epilepsy. Interestingly, for the first time, we show that an FDA-approved drug, celecoxib, rescues the Kv1.2 defect and alleviates seizure susceptibility in LGI1-/- mice, as well as improving their survival. Thus, we suggest that celecoxib is a promising drug for the treatment of ADLTE patients.
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Fukata M, Yokoi N, Fukata Y. Neurobiology of autoimmune encephalitis. Curr Opin Neurobiol 2018; 48:1-8. [DOI: 10.1016/j.conb.2017.07.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/28/2017] [Indexed: 01/17/2023]
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Ren L, Wu C, Yang K, Chen S, Ye P, Wu J, Zhang A, Huang X, Wang K, Deng P, Ding X, Chen M, Xia J. A Disintegrin and Metalloprotease-22 Attenuates Hypertrophic Remodeling in Mice Through Inhibition of the Protein Kinase B Signaling Pathway. J Am Heart Assoc 2018; 7:JAHA.117.005696. [PMID: 29358191 PMCID: PMC5850139 DOI: 10.1161/jaha.117.005696] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Severe cardiac hypertrophy can lead to cardiac remodeling and even heart failure in the end, which is a leading cause of cardiovascular disease-related mortality worldwide. A disintegrin and metalloprotease-22 (ADAM22), a member of the transmembrane and secreted metalloendopeptidase family, participates in many biological processes, including those in the cardiovascular system. However, there is no explicit information on whether ADAM22 can regulate the process of cardiac hypertrophy; the effects that ADAM22 exerts in cardiac hypertrophy remain elusive. METHODS AND RESULTS We observed significantly increased ADAM22 expression in failing hearts from patients with dilated cardiomyopathy and hypertrophic cardiomyopathy; the same trend was observed in mice induced by transaortic constriction and in neonatal rat cardiomyocytes treated by angiotensin II. Therefore, we constructed both cardiac-specific ADAM22 overexpression and knockout mice. At 4 weeks after transaortic constriction, cardiac-specific ADAM22 knockout, by the CRISPR/Cas9 (clustered regularly interspaced palindromic repeat (CRISPR)-Cas9) system, deteriorated the severity of cardiac hypertrophy in mice, whereas cardiac-specific ADAM22 overexpression mitigated the degrees of cardiac hypertrophy in mice. Similarly, altered ADAM22 expression modulated the angiotensin II-mediated cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. After screening several signaling pathways, we found ADAM22 played a role in inhibition of protein kinase B (AKT) activation. Under the cardiac-specific ADAM22 knockout background, AKT activation was enhanced in transaortic constriction-induced mice and angiotensin II-stimulated neonatal rat cardiomyocytes, with a severe degree of cardiac hypertrophy. Treatment of a specific AKT inhibitor attenuated the transaortic constriction-enhanced AKT activation and cardiac hypertrophy in mice. CONCLUSIONS The findings demonstrated that ADAM22 negatively regulates the AKT activation and the process of cardiac hypertrophy and may provide new insights into the pathobiological features of cardiac hypertrophy.
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Affiliation(s)
- Lingyun Ren
- Department of Anesthesiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chuangyan Wu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Yang
- Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanshan Chen
- Key Laboratory for Molecular Diagnosis of Hubei Province, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ping Ye
- Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jie Wu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Anchen Zhang
- Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaofan Huang
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ke Wang
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Deng
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangchao Ding
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Manhua Chen
- Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiahong Xia
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Hivert B, Marien L, Agbam KN, Faivre-Sarrailh C. ADAM22 and ADAM23 modulate the targeting of the Kv1 channel-associated protein LGI1 to the axon initial segment. J Cell Sci 2018; 132:jcs.219774. [DOI: 10.1242/jcs.219774] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 12/19/2018] [Indexed: 01/30/2023] Open
Abstract
The distribution of voltage-gated potassium channels Kv1 at the axon initial segment (AIS) influences neuronal intrinsic excitability. Kv1.1/1.2 subunits are associated with cell adhesion molecules (CAMs), including Caspr2 and LGI1 that are implicated in autoimmune and genetic neurological diseases with seizures. In particular, mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy (ADLTE). Here, using rat hippocampal neurons in culture, we showed that LGI1 is recruited at the AIS and colocalized with ADAM22 and Kv1 channels. Strikingly, the missense mutations S473L and R474Q of LGI1 identified in ADLTE prevent its association with ADAM22 and enrichment at the AIS. Moreover, we observed that ADAM22 or ADAM23 modulates the trafficking of LGI1, and promotes its ER export and expression at the overall neuronal cell surface. Live-cell imaging indicated that LGI1 is co-transported in axonal vesicles with ADAM22 or ADAM23. Finally, we showed that ADAM22 and ADAM23 also associate with Caspr2 and TAG-1 to be selectively targeted within different axonal sub-regions. So, the combinatorial expression of Kv1-associated CAMs may be critical to tune intrinsic excitability in physiological or epileptogenic context.
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Affiliation(s)
- Bruno Hivert
- Aix Marseille Université, INSERM UMR1249, F-13273 Marseille, France
- Present address: Aix Marseille Université, CNRS UMR7289, Institut de Neurosciences de la Timone, F-13385 Marseille, France
| | - Laurène Marien
- Aix Marseille Université, INSERM UMR1249, F-13273 Marseille, France
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Yu Y, Hasegawa D, Fujiwara-Igarashi A, Hamamoto Y, Mizoguchi S, Kuwabara T, Fujita M. Molecular cloning and characterization of the family of feline leucine-rich glioma-inactivated (LGI) genes, and mutational analysis in familial spontaneous epileptic cats. BMC Vet Res 2017; 13:389. [PMID: 29237452 PMCID: PMC5729232 DOI: 10.1186/s12917-017-1308-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/28/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leucine-rich glioma-inactivated (LGI) proteins play a critical role in synaptic transmission. Dysfunction of these genes and encoded proteins is associated with neurological disorders such as genetic epilepsy or autoimmune limbic encephalitis in animals and human. Familial spontaneous epileptic cats (FSECs) are the only feline strain and animal model of familial temporal lobe epilepsy. The seizure semiology of FSECs comprises recurrent limbic seizures with or without evolution into generalized epileptic seizures, while cats with antibodies against voltage-gated potassium channel complexed/LGI1 show limbic encephalitis and recurrent limbic seizures. However, it remains unclear whether the genetics underlying FSECs are associated with LGI family genes. In the present study, we cloned and characterized the feline LGI1-4 genes and examined their association with FSECs. Conventional PCR techniques were performed for cloning and mutational analysis. Characterization was predicted using bioinformatics software. RESULTS The cDNAs of feline LGI1-4 contained 1674-bp, 1650-bp, 1647-bp, and 1617-bp open reading frames, respectively, and encoded proteins comprising 557, 549, 548, and 538 amino acid residues, respectively. The feline LGI1-4 putative protein sequences showed high homology with Homo sapiens, Canis familiaris, Bos taurus, Sus scrofa, and Equus caballus (92%-100%). Mutational analysis in 8 FSECs and 8 controls for LGI family genes revealed 3 non-synonymous and 14 synonymous single nucleotide polymorphisms in the coding region. Only one non-synonymous single nucleotide polymorphism in LGI4 was found in 3 out of 8 FSECs. Using three separate computational tools, this mutation was not predicted to be disease causing. No co-segregation of the disease was found with any variant. CONCLUSIONS We cloned the cDNAs of the four feline LGI genes, analyzed the amino acid sequences, and revealed that epilepsy in FSEC is not a monogenic disorder associated with LGI genes.
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Affiliation(s)
- Yoshihiko Yu
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan.
| | - Daisuke Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan.
| | - Aki Fujiwara-Igarashi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Yuji Hamamoto
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Shunta Mizoguchi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Takayuki Kuwabara
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Michio Fujita
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
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Epilepsy and synaptic proteins. Curr Opin Neurobiol 2017; 45:1-8. [DOI: 10.1016/j.conb.2017.02.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/25/2017] [Accepted: 02/01/2017] [Indexed: 12/22/2022]
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Jin H, Komita M, Aoe T. The Role of BiP Retrieval by the KDEL Receptor in the Early Secretory Pathway and its Effect on Protein Quality Control and Neurodegeneration. Front Mol Neurosci 2017; 10:222. [PMID: 28769758 PMCID: PMC5511815 DOI: 10.3389/fnmol.2017.00222] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 06/27/2017] [Indexed: 12/14/2022] Open
Abstract
Protein quality control in the early secretory pathway is a ubiquitous eukaryotic mechanism for adaptation to endoplasmic reticulum (ER) stress. An ER molecular chaperone, immunoglobulin heavy chain-binding protein (BiP), is one of the essential components in this process. BiP interacts with nascent proteins to facilitate their folding. BiP also plays an important role in preventing aggregation of misfolded proteins and regulating the ER stress response when cells suffer various injuries. BiP is a member of the 70-kDa heat shock protein (HSP70) family of molecular chaperones that resides in the ER. Interaction between BiP and unfolded proteins is mediated by a substrate-binding domain and a nucleotide-binding domain for ATPase activity, leading to protein folding and maturation. BiP also possesses a retrieval motif in its carboxyl terminal. When BiP is secreted from the ER, the Lys-Asp-Glu-Leu (KDEL) receptor in the post-ER compartments binds with the carboxyl terminal KDEL sequence of BiP and returns BiP to the ER via coat protein complex I (COPI) vesicular transport. Although yeast studies showed that BiP retrieval by the KDEL receptor is not essential in single cells, it is crucial for multicellular organisms, where some essential proteins require retrieval to facilitate folding and maturation. Experiments in knock-in mice expressing mutant BiP with the retrieval motif deleted revealed a unique role of BiP retrieval by the KDEL receptor in neuronal development and age-related neurodegeneration.
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Affiliation(s)
- Hisayo Jin
- Department of Anesthesiology, Graduate School of Medicine, Chiba UniversityChiba, Japan
| | - Mari Komita
- Department of Anesthesiology, Chiba Rosai HospitalIchihara, Japan
| | - Tomohiko Aoe
- Pain Center, Chiba Medical Center, Teikyo UniversityIchihara, Japan
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Peachey NS, Hasan N, FitzMaurice B, Burrill S, Pangeni G, Karst SY, Reinholdt L, Berry ML, Strobel M, Gregg RG, McCall MA, Chang B. A missense mutation in Grm6 reduces but does not eliminate mGluR6 expression or rod depolarizing bipolar cell function. J Neurophysiol 2017; 118:845-854. [PMID: 28490646 DOI: 10.1152/jn.00888.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 05/03/2017] [Accepted: 05/03/2017] [Indexed: 01/01/2023] Open
Abstract
GRM6 encodes the metabotropic glutamate receptor 6 (mGluR6) used by retinal depolarizing bipolar cells (DBCs). Mutations in GRM6 lead to DBC dysfunction and underlie the human condition autosomal recessive complete congenital stationary night blindness. Mouse mutants for Grm6 are important models for this condition. Here we report a new Grm6 mutant, identified in an electroretinogram (ERG) screen of mice maintained at The Jackson Laboratory. The Grm6nob8 mouse has a reduced-amplitude b-wave component of the ERG, which reflects light-evoked DBC activity. Sequencing identified a missense mutation that converts a highly conserved methionine within the ligand binding domain to leucine (p.Met66Leu). Consistent with prior studies of Grm6 mutant mice, the laminar size and structure in the Grm6nob8 retina were comparable to control. The Grm6nob8 phenotype is distinguished from other Grm6 mutants that carry a null allele by a reduced but not absent ERG b-wave, decreased but present expression of mGluR6 at DBC dendritic tips, and mislocalization of mGluR6 to DBC somas. Consistent with a reduced but not absent b-wave, there were a subset of retinal ganglion cells whose responses to light onset have times to peak within the range of those in control retinas. These data indicate that the p.Met66Leu mutant mGluR6 is trafficked less than control. However, the mGluR6 that is localized to the DBC dendritic tips is able to initiate DBC signal transduction. The Grm6nob8 mouse extends the Grm6 allelic series and will be useful for elucidating the role of mGluR6 in DBC signal transduction and in human disease.NEW & NOTEWORTHY This article describes a mouse model of the human disease complete congenital stationary night blindness in which the mutation reduces but does not eliminate GRM6 expression and bipolar cell function, a distinct phenotype from that seen in other Grm6 mouse models.
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Affiliation(s)
- Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio.,Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.,Department of Ophthalmology, Cleveland Clinic College of Medicine of Case Western Reserve University, Cleveland, Ohio
| | - Nazarul Hasan
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky
| | | | | | - Gobinda Pangeni
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky; and
| | | | | | | | | | - Ronald G Gregg
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky.,Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky; and
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky; and.,Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine;
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Fukata Y, Yokoi N, Miyazaki Y, Fukata M. The LGI1–ADAM22 protein complex in synaptic transmission and synaptic disorders. Neurosci Res 2017; 116:39-45. [DOI: 10.1016/j.neures.2016.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/18/2016] [Accepted: 09/22/2016] [Indexed: 12/21/2022]
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Ariyasu D, Yoshida H, Hasegawa Y. Endoplasmic Reticulum (ER) Stress and Endocrine Disorders. Int J Mol Sci 2017; 18:ijms18020382. [PMID: 28208663 PMCID: PMC5343917 DOI: 10.3390/ijms18020382] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/24/2017] [Accepted: 02/03/2017] [Indexed: 12/15/2022] Open
Abstract
The endoplasmic reticulum (ER) is the organelle where secretory and membrane proteins are synthesized and folded. Unfolded proteins that are retained within the ER can cause ER stress. Eukaryotic cells have a defense system called the “unfolded protein response” (UPR), which protects cells from ER stress. Cells undergo apoptosis when ER stress exceeds the capacity of the UPR, which has been revealed to cause human diseases. Although neurodegenerative diseases are well-known ER stress-related diseases, it has been discovered that endocrine diseases are also related to ER stress. In this review, we focus on ER stress-related human endocrine disorders. In addition to diabetes mellitus, which is well characterized, several relatively rare genetic disorders such as familial neurohypophyseal diabetes insipidus (FNDI), Wolfram syndrome, and isolated growth hormone deficiency type II (IGHD2) are discussed in this article.
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Affiliation(s)
- Daisuke Ariyasu
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Hiderou Yoshida
- Department of Biochemistry and Molecular Biology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.
| | - Yukihiro Hasegawa
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo 183-8561, Japan.
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Dazzo E, Leonardi E, Belluzzi E, Malacrida S, Vitiello L, Greggio E, Tosatto SCE, Nobile C. Secretion-Positive LGI1 Mutations Linked to Lateral Temporal Epilepsy Impair Binding to ADAM22 and ADAM23 Receptors. PLoS Genet 2016; 12:e1006376. [PMID: 27760137 PMCID: PMC5070869 DOI: 10.1371/journal.pgen.1006376] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/20/2016] [Indexed: 01/17/2023] Open
Abstract
Autosomal dominant lateral temporal epilepsy (ADTLE) is a focal epilepsy syndrome caused by mutations in the LGI1 gene, which encodes a secreted protein. Most ADLTE-causing mutations inhibit LGI1 protein secretion, and only a few secretion-positive missense mutations have been reported. Here we describe the effects of four disease-causing nonsynonymous LGI1 mutations, T380A, R407C, S473L, and R474Q, on protein secretion and extracellular interactions. Expression of LGI1 mutant proteins in cultured cells shows that these mutations do not inhibit protein secretion. This finding likely results from the lack of effects of these mutations on LGI1 protein folding, as suggested by 3D protein modelling. In addition, immunofluorescence and co-immunoprecipitation experiments reveal that all four mutations significantly impair interaction of LGI1 with the ADAM22 and ADAM23 receptors on the cell surface. These results support the existence of a second mechanism, alternative to inhibition of protein secretion, by which ADLTE-causing LGI1 mutations exert their loss-of-function effect extracellularly, and suggest that interactions of LGI1 with both ADAM22 and ADAM23 play an important role in the molecular mechanisms leading to ADLTE. Temporal lobe epilepsy is the most common form of focal epilepsy. It is frequently associated with structural brain abnormalities, but genetic forms caused by mutations in major genes have also been described. Autosomal dominant lateral temporal epilepsy (ADLTE) is a familial condition characterized by focal seizures with prominent auditory symptoms. ADLTE-causing mutations are found in the LGI1 gene in about 30% of affected families. LGI1 encodes a protein, LGI1, that is secreted by neurons. Most LGI1 mutations suppress protein secretion, thereby preventing protein function in the extracellular environment. In this paper, we examine the effects of four LGI1 mutations and show that they do not inhibit secretion of the LGI1 protein but impair its interaction with the neuronal receptors ADAM22 and ADAM23. In agreement with these findings, a three- dimensional model of the protein predicts that these mutations have no impact on LGI1 structure but instead may affect amino acids that are critical for interactions with ADAM receptors. Our results provide novel evidence for an extracellular mechanism through which mutant LGI1 proteins cause ADLTE and strengthen the importance of LGI1-ADAM22/23 protein complex in the mechanisms underlying ADLTE.
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Affiliation(s)
- Emanuela Dazzo
- CNR-Neuroscience Institute, Section of Padua, Padova, Italy
| | - Emanuela Leonardi
- Department of Woman and Child’s Health, University of Padua, Padova, Italy
| | - Elisa Belluzzi
- Department of Biology, University of Padua, Padova, Italy
| | - Sandro Malacrida
- Department of Biomedical Sciences, University of Padua, Padova, Italy
| | | | - Elisa Greggio
- Department of Biology, University of Padua, Padova, Italy
| | - Silvio C. E. Tosatto
- CNR-Neuroscience Institute, Section of Padua, Padova, Italy
- Department of Biomedical Sciences, University of Padua, Padova, Italy
| | - Carlo Nobile
- CNR-Neuroscience Institute, Section of Padua, Padova, Italy
- Department of Biomedical Sciences, University of Padua, Padova, Italy
- * E-mail:
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Uggenti C, Briant K, Streit AK, Thomson S, Koay YH, Baines RA, Swanton E, Manson FD. Restoration of mutant bestrophin-1 expression, localisation and function in a polarised epithelial cell model. Dis Model Mech 2016; 9:1317-1328. [PMID: 27519691 PMCID: PMC5117222 DOI: 10.1242/dmm.024216] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 07/21/2016] [Indexed: 01/13/2023] Open
Abstract
Autosomal recessive bestrophinopathy (ARB) is a retinopathy caused by mutations in the bestrophin-1 protein, which is thought to function as a Ca2+-gated Cl− channel in the basolateral surface of the retinal pigment epithelium (RPE). Using a stably transfected polarised epithelial cell model, we show that four ARB mutant bestrophin-1 proteins were mislocalised and subjected to proteasomal degradation. In contrast to the wild-type bestrophin-1, each of the four mutant proteins also failed to conduct Cl− ions in transiently transfected cells as determined by whole-cell patch clamp. We demonstrate that a combination of two clinically approved drugs, bortezomib and 4-phenylbutyrate (4PBA), successfully restored the expression and localisation of all four ARB mutant bestrophin-1 proteins. Importantly, the Cl− conductance function of each of the mutant bestrophin-1 proteins was fully restored to that of wild-type bestrophin-1 by treatment of cells with 4PBA alone. The functional rescue achieved with 4PBA is significant because it suggests that this drug, which is already approved for long-term use in infants and adults, might represent a promising therapy for the treatment of ARB and other bestrophinopathies resulting from missense mutations in BEST1. Summary: Chemical chaperone 4PBA fully restores Cl− conductance activity for mutant bestrophin-1 proteins associated with inherited retinal dystrophy, autosomal recessive bestrophinopathy.
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Affiliation(s)
- Carolina Uggenti
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Kit Briant
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Anne-Kathrin Streit
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Steven Thomson
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Yee Hui Koay
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Richard A Baines
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Eileithyia Swanton
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Forbes D Manson
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
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