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Järvelä V, Hamze M, Komulainen-Ebrahim J, Rahikkala E, Piispala J, Kallio M, Kangas SM, Nickl T, Huttula M, Hinttala R, Uusimaa J, Medina I, Immonen EV. A novel pathogenic SLC12A5 missense variant in epilepsy of infancy with migrating focal seizures causes impaired KCC2 chloride extrusion. Front Mol Neurosci 2024; 17:1372662. [PMID: 38660387 PMCID: PMC11039960 DOI: 10.3389/fnmol.2024.1372662] [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: 01/18/2024] [Accepted: 03/19/2024] [Indexed: 04/26/2024] Open
Abstract
The potassium-chloride co-transporter 2, KCC2, is a neuron-specific ion transporter that plays a multifunctional role in neuronal development. In mature neurons, KCC2 maintains a low enough intracellular chloride concentration essential for inhibitory neurotransmission. During recent years, pathogenic variants in the KCC2 encoding gene SLC12A5 affecting the functionality or expression of the transporter protein have been described in several patients with epilepsy of infancy with migrating focal seizures (EIMFS), a devastating early-onset developmental and epileptic encephalopathy. In this study, we identified a novel recessively inherited SLC12A5 c.692G>A, p. (R231H) variant in a patient diagnosed with severe and drug-resistant EIMFS and profound intellectual disability. The functionality of the variant was assessed in vitro by means of gramicidin-perforated patch-clamp experiments and ammonium flux assay, both of which indicated a significant reduction in chloride extrusion. Based on surface immunolabeling, the variant showed a reduction in membrane expression. These findings implicate pathogenicity of the SLC12A5 variant that leads to impaired inhibitory neurotransmission, increasing probability for hyperexcitability and epileptogenesis.
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Affiliation(s)
- Viivi Järvelä
- Nano and Molecular Systems Research Unit, University of Oulu, Oulu, Finland
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Mira Hamze
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Jonna Komulainen-Ebrahim
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
- Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Oulu, Finland
| | - Elisa Rahikkala
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
- Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - Johanna Piispala
- Department of Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Mika Kallio
- Department of Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Salla M. Kangas
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Tereza Nickl
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Marko Huttula
- Nano and Molecular Systems Research Unit, University of Oulu, Oulu, Finland
| | - Reetta Hinttala
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Johanna Uusimaa
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
- Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Oulu, Finland
| | - Igor Medina
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Esa-Ville Immonen
- Nano and Molecular Systems Research Unit, University of Oulu, Oulu, Finland
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
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2
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Kok M, Hartnett-Scott K, Happe CL, MacDonald ML, Aizenman E, Brodsky JL. The expression system influences stability, maturation efficiency, and oligomeric properties of the potassium-chloride co-transporter KCC2. Neurochem Int 2024; 174:105695. [PMID: 38373478 PMCID: PMC10923169 DOI: 10.1016/j.neuint.2024.105695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024]
Abstract
The neuron-specific K+/Cl- co-transporter 2, KCC2, which is critical for brain development, regulates γ-aminobutyric acid-dependent inhibitory neurotransmission. Consistent with its function, mutations in KCC2 are linked to neurodevelopmental disorders, including epilepsy, schizophrenia, and autism. KCC2 possesses 12 transmembrane spans and forms an intertwined dimer. Based on its complex architecture and function, reduced cell surface expression and/or activity have been reported when select disease-associated mutations are present in the gene encoding the protein, SLC12A5. These data suggest that KCC2 might be inherently unstable, as seen for other complex polytopic ion channels, thus making it susceptible to cellular quality control pathways that degrade misfolded proteins. To test these hypotheses, we examined KCC2 stability and/or maturation in five model systems: yeast, HEK293 cells, primary rat neurons, and rat and human brain synaptosomes. Although studies in yeast revealed that KCC2 is selected for endoplasmic reticulum-associated degradation (ERAD), experiments in HEK293 cells supported a more subtle role for ERAD in maintaining steady-state levels of KCC2. Nevertheless, this system allowed for an analysis of KCC2 glycosylation in the ER and Golgi, which serves as a read-out for transport through the secretory pathway. In turn, KCC2 was remarkably stable in primary rat neurons, suggesting that KCC2 folds efficiently in more native systems. Consistent with these data, the mature glycosylated form of KCC2 was abundant in primary rat neurons as well as in rat and human brain. Together, this work details the first insights into the influence that the cellular and membrane environments have on several fundamental KCC2 properties, acknowledges the advantages and disadvantages of each system, and helps set the stage for future experiments to assess KCC2 in a normal or disease setting.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Karen Hartnett-Scott
- Department of Neurobiology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Cassandra L Happe
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Matthew L MacDonald
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Elias Aizenman
- Department of Neurobiology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
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3
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Zhang MW, Liang XY, Wang J, Gao LD, Liao HJ, He YH, Yi YH, He N, Liao WP. Epilepsy-associated genes: an update. Seizure 2024; 116:4-13. [PMID: 37777370 DOI: 10.1016/j.seizure.2023.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/31/2023] [Accepted: 09/23/2023] [Indexed: 10/02/2023] Open
Abstract
PURPOSE To provide an updated list of epilepsy-associated genes based on clinical-genetic evidence. METHODS Epilepsy-associated genes were systematically searched and cross-checked from the OMIM, HGMD, and PubMed databases up to July 2023. To facilitate the reference for the epilepsy-associated genes that are potentially common in clinical practice, the epilepsy-associated genes were ranked by the mutation number in the HGMD database and by case number in the China Epilepsy Gene 1.0 project, which targeted common epilepsy. RESULTS Based on the OMIM database, 1506 genes were identified to be associated with epilepsy and were classified into three categories according to their potential association with epilepsy or other abnormal phenotypes, including 168 epilepsy genes that were associated with epilepsies as pure or core symptoms, 364 genes that were associated with neurodevelopmental disorders as the main symptom and epilepsy, and 974 epilepsy-related genes that were associated with gross physical/systemic abnormalities accompanied by epilepsy/seizures. Among the epilepsy genes, 115 genes (68.5%) were associated with epileptic encephalopathy. After cross-checking with the HGMD and PubMed databases, an additional 1440 genes were listed as potential epilepsy-associated genes, of which 278 genes have been repeatedly identified variants in patients with epilepsy. The top 100 frequently reported/identified epilepsy-associated genes from the HGMD database and the China Epilepsy Gene 1.0 project were listed, among which 40 genes were identical in both sources. SIGNIFICANCE Recognition of epilepsy-associated genes will facilitate genetic screening strategies and be helpful for precise molecular diagnosis and treatment of epilepsy in clinical practice.
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Affiliation(s)
- Meng-Wen Zhang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Xiao-Yu Liang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Jie Wang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Liang-Di Gao
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Han-Jun Liao
- University of South China, Hengyang, 421001, China
| | - Yun-Hua He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Yong-Hong Yi
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Na He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
| | - Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
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Comas M, De Pietri Tonelli D, Berdondini L, Astiz M. Ontogeny of the circadian system: a multiscale process throughout development. Trends Neurosci 2024; 47:36-46. [PMID: 38071123 DOI: 10.1016/j.tins.2023.11.004] [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: 07/23/2023] [Revised: 10/02/2023] [Accepted: 11/12/2023] [Indexed: 01/12/2024]
Abstract
The 24 h (circadian) timing system develops in mammals during the perinatal period. It carries out the essential task of anticipating daily recurring environmental changes to identify the best time of day for each molecular, cellular, and systemic process. Although significant knowledge has been acquired about the organization and function of the adult circadian system, relatively little is known about its ontogeny. During the perinatal period, the circadian system progressively gains functionality under the influence of the early environment. This review explores current evidence on the development of the circadian clock in mammals, highlighting the multilevel complexity of the process and the importance of gaining a better understanding of its underlying biology.
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Affiliation(s)
- Maria Comas
- Circadian Physiology of Neurons and Glia Laboratory, Achucarro Basque Center for Neuroscience, 48940 Leioa, Basque Country, Spain
| | | | - Luca Berdondini
- Microtechnology for Neuroelectronics, Fondazione Istituto Italiano di Tecnologia (IIT), 16163 Genova, Italy
| | - Mariana Astiz
- Circadian Physiology of Neurons and Glia Laboratory, Achucarro Basque Center for Neuroscience, 48940 Leioa, Basque Country, Spain; Ikerbasque - Basque Foundation for Science, Bilbao, Spain; Institute of Neurobiology, University of Lübeck, 23562 Lübeck, Germany.
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5
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McMoneagle E, Zhou J, Zhang S, Huang W, Josiah SS, Ding K, Wang Y, Zhang J. Neuronal K +-Cl - cotransporter KCC2 as a promising drug target for epilepsy treatment. Acta Pharmacol Sin 2024; 45:1-22. [PMID: 37704745 PMCID: PMC10770335 DOI: 10.1038/s41401-023-01149-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 08/02/2023] [Indexed: 09/14/2023] Open
Abstract
Epilepsy is a prevalent neurological disorder characterized by unprovoked seizures. γ-Aminobutyric acid (GABA) serves as the primary fast inhibitory neurotransmitter in the brain, and GABA binding to the GABAA receptor (GABAAR) regulates Cl- and bicarbonate (HCO3-) influx or efflux through the channel pore, leading to GABAergic inhibition or excitation, respectively. The neuron-specific K+-Cl- cotransporter 2 (KCC2) is essential for maintaining a low intracellular Cl- concentration, ensuring GABAAR-mediated inhibition. Impaired KCC2 function results in GABAergic excitation associated with epileptic activity. Loss-of-function mutations and altered expression of KCC2 lead to elevated [Cl-]i and compromised synaptic inhibition, contributing to epilepsy pathogenesis in human patients. KCC2 antagonism studies demonstrate the necessity of limiting neuronal hyperexcitability within the brain, as reduced KCC2 functioning leads to seizure activity. Strategies focusing on direct (enhancing KCC2 activation) and indirect KCC2 modulation (altering KCC2 phosphorylation and transcription) have proven effective in attenuating seizure severity and exhibiting anti-convulsant properties. These findings highlight KCC2 as a promising therapeutic target for treating epilepsy. Recent advances in understanding KCC2 regulatory mechanisms, particularly via signaling pathways such as WNK, PKC, BDNF, and its receptor TrkB, have led to the discovery of novel small molecules that modulate KCC2. Inhibiting WNK kinase or utilizing newly discovered KCC2 agonists has demonstrated KCC2 activation and seizure attenuation in animal models. This review discusses the role of KCC2 in epilepsy and evaluates its potential as a drug target for epilepsy treatment by exploring various strategies to regulate KCC2 activity.
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Affiliation(s)
- Erin McMoneagle
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK
| | - Jin Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Shiyao Zhang
- Institute of Cardiovascular Diseases, Xiamen Cardiovascular Hospital Xiamen University, School of Medicine, Xiamen University, Xiang'an Nan Lu, Xiamen, 361102, China
| | - Weixue Huang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK.
- Institute of Cardiovascular Diseases, Xiamen Cardiovascular Hospital Xiamen University, School of Medicine, Xiamen University, Xiang'an Nan Lu, Xiamen, 361102, China.
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
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6
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Zhang S, Meor Azlan NF, Josiah SS, Zhou J, Zhou X, Jie L, Zhang Y, Dai C, Liang D, Li P, Li Z, Wang Z, Wang Y, Ding K, Wang Y, Zhang J. The role of SLC12A family of cation-chloride cotransporters and drug discovery methodologies. J Pharm Anal 2023; 13:1471-1495. [PMID: 38223443 PMCID: PMC10785268 DOI: 10.1016/j.jpha.2023.09.002] [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: 03/04/2023] [Revised: 06/20/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
The solute carrier family 12 (SLC12) of cation-chloride cotransporters (CCCs) comprises potassium chloride cotransporters (KCCs, e.g. KCC1, KCC2, KCC3, and KCC4)-mediated Cl- extrusion, and sodium potassium chloride cotransporters (N[K]CCs, NKCC1, NKCC2, and NCC)-mediated Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. Gain-of-function or loss-of-function of these ion transporters can cause diseases in many tissues. In recent years, there have been considerable advances in our understanding of CCCs' control mechanisms in cell volume regulations, with many techniques developed in studying the functions and activities of CCCs. Classic approaches to directly measure CCC activity involve assays that measure the transport of potassium substitutes through the CCCs. These techniques include the ammonium pulse technique, radioactive or nonradioactive rubidium ion uptake-assay, and thallium ion-uptake assay. CCCs' activity can also be indirectly observed by measuring γ-aminobutyric acid (GABA) activity with patch-clamp electrophysiology and intracellular chloride concentration with sensitive microelectrodes, radiotracer 36Cl-, and fluorescent dyes. Other techniques include directly looking at kinase regulatory sites phosphorylation, flame photometry, 22Na+ uptake assay, structural biology, molecular modeling, and high-throughput drug screening. This review summarizes the role of CCCs in genetic disorders and cell volume regulation, current methods applied in studying CCCs biology, and compounds developed that directly or indirectly target the CCCs for disease treatments.
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Affiliation(s)
- Shiyao Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoxia Zhou
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Lingjun Jie
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Yanhui Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Cuilian Dai
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Dong Liang
- Aurora Discovery Inc., Foshan, Guangdong, 528300, China
| | - Peifeng Li
- Institute for Translational Medicine, Qingdao University, Qingdao, Shandong, 266021, China
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Zhen Wang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Jinwei Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
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Abstract
Rett syndrome is a neurodevelopmental disorder caused by loss-of-function mutations in the methyl-CpG binding protein-2 (MeCP2) gene that is characterized by epilepsy, intellectual disability, autistic features, speech deficits, and sleep and breathing abnormalities. Neurologically, patients with all three disorders display microcephaly, aberrant dendritic morphology, reduced spine density, and an imbalance of excitatory/inhibitory signaling. Loss-of-function mutations in the cyclin-dependent kinase-like 5 (CDKL5) and FOXG1 genes also cause similar behavioral and neurobiological defects and were referred to as congenital or variant Rett syndrome. The relatively recent realization that CDKL5 deficiency disorder (CDD), FOXG1 syndrome, and Rett syndrome are distinct neurodevelopmental disorders with some distinctive features have resulted in separate focus being placed on each disorder with the assumption that distinct molecular mechanisms underlie their pathogenesis. However, given that many of the core symptoms and neurological features are shared, it is likely that the disorders share some critical molecular underpinnings. This review discusses the possibility that deregulation of common molecules in neurons and astrocytes plays a central role in key behavioral and neurological abnormalities in all three disorders. These include KCC2, a chloride transporter, vGlut1, a vesicular glutamate transporter, GluD1, an orphan-glutamate receptor subunit, and PSD-95, a postsynaptic scaffolding protein. We propose that reduced expression or activity of KCC2, vGlut1, PSD-95, and AKT, along with increased expression of GluD1, is involved in the excitatory/inhibitory that represents a key aspect in all three disorders. In addition, astrocyte-derived brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), and inflammatory cytokines likely affect the expression and functioning of these molecules resulting in disease-associated abnormalities.
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Affiliation(s)
- Santosh R D’Mello
- Department of Biological Sciences, Louisiana State University Shreveport, Shreveport, LA 71104, USA
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8
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Liu N, Li J, Gao K, Perszyk RE, Zhang J, Wang J, Wu Y, Jenkins A, Yuan H, Traynelis SF, Jiang Y. De novo CLPTM1 variants with reduced GABA A R current response in patients with epilepsy. Epilepsia 2023; 64:2968-2981. [PMID: 37577761 PMCID: PMC10840799 DOI: 10.1111/epi.17746] [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: 02/08/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
OBJECTIVE To investigate the clinical features and potential pathogenesis mechanism of de novo CLPTM1 variants associated with epilepsy. METHODS Identify de novo genetic variants associated with epilepsy by reanalyzing trio-based whole-exome sequencing data. We analyzed the clinical characteristics of patients with these variants and performed functional in vitro studies in cells expressing mutant complementary DNA for these variants using whole-cell voltage-clamp current recordings and outside-out patch-clamp recordings from transiently transfected human embryonic kidney (HEK) cells. RESULTS Two de novo missense variants related to epilepsy were identified in the CLPTM1 gene. Functional studies indicated that CLPTM1-p.R454H and CLPTM1-p.R568Q variants reduced the γ-aminobutyric acid A receptor (GABAA R) current response amplitude recorded under voltage clamp compared to the wild-type receptors. These variants also reduced the charge transfer and altered the time course of desensitization and deactivation following rapid removal of GABA. The surface expression of the GABAA R γ2 subunit from the CLPTM1-p.R568Q group was significantly reduced compared to CLPTM1-WT. SIGNIFICANCE This is the first report of functionally relevant variants within the CLPTM1 gene. Patch-clamp recordings showed that these de novo CLPTM1 variants reduce GABAA R currents and charge transfer, which should promote excitation and hypersynchronous activity. This study may provide insights into the molecular mechanisms of the CLPTM1 variants underlying the patients' phenotypes, as well as for exploring potential therapeutic targets for epilepsy.
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Affiliation(s)
- Nana Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Jinliang Li
- Department of Pediatrics, Central People's Hospital of Zhanjiang, Guangdong, China
| | - Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jing Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Ye Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Andrew Jenkins
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, Connecticut, USA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- Children Epilepsy Center, Peking University First Hospital, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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9
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Pethe A, Hamze M, Giannaki M, Heimrich B, Medina I, Hartmann AM, Roussa E. K +/Cl - cotransporter 2 (KCC2) and Na +/ HCO3- cotransporter 1 (NBCe1) interaction modulates profile of KCC2 phosphorylation. Front Cell Neurosci 2023; 17:1253424. [PMID: 37881493 PMCID: PMC10595033 DOI: 10.3389/fncel.2023.1253424] [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: 07/05/2023] [Accepted: 09/07/2023] [Indexed: 10/27/2023] Open
Abstract
K+/Cl- cotransporter 2 (KCC2) is a major Cl- extruder in mature neurons and is responsible for the establishment of low intracellular [Cl-], necessary for fast hyperpolarizing GABAA-receptor mediated synaptic inhibition. Electrogenic sodium bicarbonate cotransporter 1 (NBCe1) is a pH regulatory protein expressed in neurons and glial cells. An interactome study identified NBCe1 as a possible interaction partner of KCC2. In this study, we investigated the putative effect of KCC2/NBCe1 interaction in baseline and the stimulus-induced phosphorylation pattern and function of KCC2. Primary mouse hippocampal neuronal cultures from wildtype (WT) and Nbce1-deficient mice, as well as HEK-293 cells stably transfected with KCC2WT, were used. The results show that KCC2 and NBCe1 are interaction partners in the mouse brain. In HEKKCC2 cells, pharmacological inhibition of NBCs with S0859 prevented staurosporine- and 4-aminopyridine (4AP)-induced KCC2 activation. In mature cultures of hippocampal neurons, however, S0859 completely inhibited postsynaptic GABAAR and, thus, could not be used as a tool to investigate the role of NBCs in GABA-dependent neuronal networks. In Nbce1-deficient immature hippocampal neurons, baseline phosphorylation of KCC2 at S940 was downregulated, compared to WT, and exposure to staurosporine failed to reduce pKCC2 S940 and T1007. In Nbce1-deficient mature neurons, baseline levels of pKCC2 S940 and T1007 were upregulated compared to WT, whereas after 4AP treatment, pKCC2 S940 was downregulated, and pKCC2 T1007 was further upregulated. Functional experiments showed that the levels of GABAAR reversal potential, baseline intracellular [Cl-], Cl- extrusion, and baseline intracellular pH were similar between WT and Nbce1-deficient neurons. Altogether, our data provide a primary description of the properties of KCC2/NBCe1 protein-protein interaction and implicate modulation of stimulus-mediated phosphorylation of KCC2 by NBCe1/KCC2 interaction-a mechanism with putative pathophysiological relevance.
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Affiliation(s)
- Abhishek Pethe
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Mira Hamze
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Marina Giannaki
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Bernd Heimrich
- Department of Neuroanatomy, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Igor Medina
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Anna-Maria Hartmann
- Division of Neurogenetics, Faculty VI, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Becker L, Hausmann J, Hartmann AM. Both chloride-binding sites are required for KCC2-mediated transport. J Biol Chem 2023; 299:105190. [PMID: 37625593 PMCID: PMC10518353 DOI: 10.1016/j.jbc.2023.105190] [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: 01/25/2023] [Revised: 07/30/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
The K+-Cl- cotransporter 2 (KCC2) plays an important role in inhibitory neurotransmission, and its impairment is associated with neurological and psychiatric disorders, including epilepsy, schizophrenia, and autism. Although KCCs transport K+ and Cl- in a 1:1 stoichiometry, two Cl- coordination sites were indicated via cryo-EM. In a comprehensive analysis, we analyzed the consequences of point mutations of residues coordinating Cl- in Cl1 and Cl2. Individual mutations of residues in Cl1 and Cl2 reduce or abolish KCC2WT function, indicating a crucial role of both Cl- coordination sites for KCC2 function. Structural changes in the extracellular loop 2 by inserting a 3xHA tag switches the K+ coordination site to another position. To investigate, whether the extension of the extracellular loop 2 with the 3xHA tag also affects the coordination of the two Cl- coordination sites, we carried out the analogous experiments for both Cl- coordinating sites in the KCC2HA construct. These analyses showed that most of the individual mutation of residues in Cl1 and Cl2 in the KCC2HA construct reduces or abolishes KCC2 function, indicating that the coordination of Cl- remains at the same position. However, the coupling of K+ and Cl- in Cl1 is still apparent in the KCC2HA construct, indicating a mutual dependence of both ions. In addition, the coordination residue Tyr569 in Cl2 shifted in KCC2HA. Thus, conformational changes in the extracellular domain affect K+ and Cl--binding sites. However, the effect on the Cl--binding sites is subtler.
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Affiliation(s)
- Lisa Becker
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Jens Hausmann
- Division of Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
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Wu X, Zhong S, Cai Y, Yang Y, Lian Y, Ding J, Wang X. Heterozygous RELN missense variants associated with genetic generalized epilepsy. Seizure 2023; 111:122-129. [PMID: 37625192 DOI: 10.1016/j.seizure.2023.08.006] [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: 03/03/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
PURPOSE The RELN gene encodes the secreted glycoprotein Reelin and has important functions in both developing and adult brains. In this study, we aimed to explore the association between the RELN and genetic generalized epilepsy (GGE). METHODS We performed whole-exome sequencing on a cohort of 92 patients with GGE. Based on amino acid sequence alignments, allele frequency, pedigree validation and computational modeling, the RELN variants were identified and clinical features of cases were summarized. Cell-based Reelin secretion assays were examined by Western blotting. Alterations of mutant Reelin transport through the secretion pathway were detected by immunofluorescence staining. RESULTS Three novel pathogenic RELN variants (3.26%; c.2260C>T/p.R754W, c.2914C>G/p.P972A and c.3029G>A/p.R1010H) were identified. All probands showed adolescence-onset generalized seizures characterized by generalized epileptiform discharges with normal EEG backgrounds, no or mild cognitive impairment, and responded well to anti-seizure medications. All these variants were located in the central regions from 1B to 2A consecutive repeats, and protein modeling demonstrated structural alterations in Reelin. Moreover, we found that these heterozygous missense variants significantly decreased the secretion of mutant proteins in HEK-293T cells, and this impairment was due to the altered transport of mutant Reelin in the secretion pathway. CONCLUSION These results suggest that RELN is potentially associated with GGE. The phenotype of GGE caused by RELN variants is relatively mild, and the pathogenic mechanism may involve a loss-of-function.
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Affiliation(s)
- Xiaoling Wu
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Shaoping Zhong
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yang Cai
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yuling Yang
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yangye Lian
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Jing Ding
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Xin Wang
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
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12
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Trejo F, Elizalde S, Mercado A, Gamba G, de losHeros P. SLC12A cryo-EM: analysis of relevant ion binding sites, structural domains, and amino acids. Am J Physiol Cell Physiol 2023; 325:C921-C939. [PMID: 37545407 DOI: 10.1152/ajpcell.00089.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/08/2023]
Abstract
The solute carrier family 12A (SLC12A) superfamily of membrane transporters modulates the movement of cations coupled with chloride across the membrane. In doing so, these cotransporters are involved in numerous aspects of human physiology: cell volume regulation, ion homeostasis, blood pressure regulation, and neurological action potential via intracellular chloride concentration modulation. Their physiological characterization has been largely studied; however, understanding the mechanics of their function and the relevance of structural domains or specific amino acids has been a pending task. In recent years, single-particle cryogenic electron microscopy (cryo-EM) has been successfully applied to members of the SLC12A family including all K+:Cl- cotransporters (KCCs), Na+:K+:2Cl- cotransporter NKCC1, and recently Na+:Cl- cotransporter (NCC); revealing structural elements that play key roles in their function. The present review analyzes the data provided by these cryo-EM reports focusing on structural domains and specific amino acids involved in ion binding, domain interactions, and other important SCL12A structural elements. A comparison of cryo-EM data from NKCC1 and KCCs is presented in the light of the two recent NCC cryo-EM studies, to propose insight into structural elements that might also be found in NCC and are necessary for its proper function. In the final sections, the importance of key coordination residues for substrate specificity and their implication on various pathophysiological conditions and genetic disorders is reviewed, as this could provide the basis to correlate structural elements with the development of novel and selective treatments, as well as mechanistic insight into the function and regulation of cation-coupled chloride cotransporters (CCCs).
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Affiliation(s)
- Fátima Trejo
- Unidad de Investigación UNAM-INC, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Stephanie Elizalde
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Adriana Mercado
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Gerardo Gamba
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Paola de losHeros
- Unidad de Investigación UNAM-INC, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
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13
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van van Hugte EJH, Schubert D, Nadif Kasri N. Excitatory/inhibitory balance in epilepsies and neurodevelopmental disorders: Depolarizing γ-aminobutyric acid as a common mechanism. Epilepsia 2023; 64:1975-1990. [PMID: 37195166 DOI: 10.1111/epi.17651] [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: 10/26/2022] [Revised: 05/13/2023] [Accepted: 05/15/2023] [Indexed: 05/18/2023]
Abstract
Epilepsy is one of the most common neurological disorders. Although many factors contribute to epileptogenesis, seizure generation is mostly linked to hyperexcitability due to alterations in excitatory/inhibitory (E/I) balance. The common hypothesis is that reduced inhibition, increased excitation, or both contribute to the etiology of epilepsy. Increasing evidence shows that this view is oversimplistic, and that increased inhibition through depolarizing γ-aminobutyric acid (GABA) similarly contributes to epileptogenisis. In early development, GABA signaling is depolarizing, inducing outward Cl- currents due to high intracellular Cl- concentrations. During maturation, the mechanisms of GABA action shift from depolarizing to hyperpolarizing, a critical event during brain development. Altered timing of this shift is associated with both neurodevelopmental disorders and epilepsy. Here, we consider the different ways that depolarizing GABA contributes to altered E/I balance and epileptogenesis, and discuss that alterations in depolarizing GABA could be a common denominator underlying seizure generation in neurodevelopmental disorders and epilepsies.
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Affiliation(s)
- Eline J H van van Hugte
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
- Department of Epileptology, Academic Centre for Epileptology (ACE) Kempenhaeghe, Heeze, the Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
- Department of Epileptology, Academic Centre for Epileptology (ACE) Kempenhaeghe, Heeze, the Netherlands
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14
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Jarvis R, Josephine Ng SF, Nathanson AJ, Cardarelli RA, Abiraman K, Wade F, Evans-Strong A, Fernandez-Campa MP, Deeb TZ, Smalley JL, Jamier T, Gurrell IK, McWilliams L, Kawatkar A, Conway LC, Wang Q, Burli RW, Brandon NJ, Chessell IP, Goldman AJ, Maguire JL, Moss SJ. Direct activation of KCC2 arrests benzodiazepine refractory status epilepticus and limits the subsequent neuronal injury in mice. Cell Rep Med 2023; 4:100957. [PMID: 36889319 PMCID: PMC10040380 DOI: 10.1016/j.xcrm.2023.100957] [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: 09/07/2022] [Revised: 11/17/2022] [Accepted: 02/06/2023] [Indexed: 03/09/2023]
Abstract
Hyperpolarizing GABAAR currents, the unitary events that underlie synaptic inhibition, are dependent upon efficient Cl- extrusion, a process that is facilitated by the neuronal specific K+/Cl- co-transporter KCC2. Its activity is also a determinant of the anticonvulsant efficacy of the canonical GABAAR-positive allosteric: benzodiazepines (BDZs). Compromised KCC2 activity is implicated in the pathophysiology of status epilepticus (SE), a medical emergency that rapidly becomes refractory to BDZ (BDZ-RSE). Here, we have identified small molecules that directly bind to and activate KCC2, which leads to reduced neuronal Cl- accumulation and excitability. KCC2 activation does not induce any overt effects on behavior but prevents the development of and terminates ongoing BDZ-RSE. In addition, KCC2 activation reduces neuronal cell death following BDZ-RSE. Collectively, these findings demonstrate that KCC2 activation is a promising strategy to terminate BDZ-resistant seizures and limit the associated neuronal injury.
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Affiliation(s)
- Rebecca Jarvis
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Shu Fun Josephine Ng
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Anna J Nathanson
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Ross A Cardarelli
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Krithika Abiraman
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Fergus Wade
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Aidan Evans-Strong
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Marina P Fernandez-Campa
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Joshua L Smalley
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Tanguy Jamier
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ian K Gurrell
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Lisa McWilliams
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Aarti Kawatkar
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Boston, MA, USA
| | - Leslie C Conway
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Qi Wang
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Boston, MA, USA
| | - Roland W Burli
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Nicholas J Brandon
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Boston, MA, USA
| | - Iain P Chessell
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Aaron J Goldman
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Jamie L Maguire
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1 6BT, UK.
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15
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Zhu Q, Shen S, Yang C, Li M, Zhang X, Li H, Zhao X, Li M, Cui Y, Ren X, Lin S. A prognostic estimation model based on mRNA-sequence data for patients with oligodendroglioma. Front Neurol 2022; 13:1074593. [PMID: 36588901 PMCID: PMC9795846 DOI: 10.3389/fneur.2022.1074593] [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: 10/19/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Background The diagnosis of oligodendroglioma based on the latest World Health Organization Classification of Tumors of the Central Nervous System (WHO CNS 5) criteria requires the codeletion of chromosome arms 1p and 19q and isocitrate dehydrogenase gene (IDH) mutation (mut). Previously identified prognostic indicators may not be completely suitable for patients with oligodendroglioma based on the new diagnostic criteria. To find potential prognostic indicators for oligodendroglioma, we analyzed the expression of mRNAs of oligodendrogliomas in Chinese Glioma Genome Atlas (CGGA). Methods We collected 165 CGGA oligodendroglioma mRNA-sequence datasets and divided them into two cohorts. Patients in the two cohorts were further classified into long-survival and short-survival subgroups. The most predictive mRNAs were filtered out of differentially expressed mRNAs (DE mRNAs) between long-survival and short-survival patients in the training cohort by least absolute shrinkage and selection operator (LASSO), and risk scores of patients were calculated. Univariate and multivariate analyses were performed to screen factors associated with survival and establish the prognostic model. qRT-PCR was used to validate the expression differences of mRNAs. Results A total of 88 DE mRNAs were identified between the long-survival and the short-survival groups in the training cohort. Seven RNAs were selected to calculate risk scores. Univariate analysis showed that risk level, age, and primary-or-recurrent status (PRS) type were statistically correlated with survival and were used as factors to establish a prognostic model for patients with oligodendroglioma. The model showed an optimal predictive accuracy with a C-index of 0.912 (95% CI, 0.679-0.981) and harbored a good agreement between the predictions and observations in both training and validation cohorts. Conclusion We established a prognostic model based on mRNA-sequence data for patients with oligodendroglioma. The predictive ability of this model was validated in a validation cohort, which demonstrated optimal accuracy. The 7 mRNAs included in the model would help predict the prognosis of patients and guide personalized treatment.
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Affiliation(s)
- Qinghui Zhu
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shaoping Shen
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chuanwei Yang
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Mingxiao Li
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiaokang Zhang
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Haoyi Li
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xuzhe Zhao
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ming Li
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yong Cui
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China,Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Xiaohui Ren
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China,Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Song Lin
- Department of Neurosurgical Oncology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China,Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China,*Correspondence: Song Lin
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Miles KD, Doll CA. Chloride imbalance in Fragile X syndrome. Front Neurosci 2022; 16:1008393. [PMID: 36312023 PMCID: PMC9596984 DOI: 10.3389/fnins.2022.1008393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/20/2022] [Indexed: 11/26/2022] Open
Abstract
Developmental changes in ionic balance are associated with crucial hallmarks in neural circuit formation, including changes in excitation and inhibition, neurogenesis, and synaptogenesis. Neuronal excitability is largely mediated by ionic concentrations inside and outside of the cell, and chloride (Cl-) ions are highly influential in early neurodevelopmental events. For example, γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the mature central nervous system (CNS). However, during early development GABA can depolarize target neurons, and GABAergic depolarization is implicated in crucial neurodevelopmental processes. This developmental shift of GABAergic neurotransmission from depolarizing to hyperpolarizing output is induced by changes in Cl- gradients, which are generated by the relative expression of Cl- transporters Nkcc1 and Kcc2. Interestingly, the GABA polarity shift is delayed in Fragile X syndrome (FXS) models; FXS is one of the most common heritable neurodevelopmental disorders. The RNA binding protein FMRP, encoded by the gene Fragile X Messenger Ribonucleoprotein-1 (Fmr1) and absent in FXS, appears to regulate chloride transporter expression. This could dramatically influence FXS phenotypes, as the syndrome is hypothesized to be rooted in defects in neural circuit development and imbalanced excitatory/inhibitory (E/I) neurotransmission. In this perspective, we summarize canonical Cl- transporter expression and investigate altered gene and protein expression of Nkcc1 and Kcc2 in FXS models. We then discuss interactions between Cl- transporters and neurotransmission complexes, and how these links could cause imbalances in inhibitory neurotransmission that may alter mature circuits. Finally, we highlight current therapeutic strategies and promising new directions in targeting Cl- transporter expression in FXS patients.
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Affiliation(s)
| | - Caleb Andrew Doll
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Children’s Hospital Colorado, Aurora, CO, United States
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17
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Hartmann AM, Nothwang HG. NKCC1 and KCC2: Structural insights into phospho-regulation. Front Mol Neurosci 2022; 15:964488. [PMID: 35935337 PMCID: PMC9355526 DOI: 10.3389/fnmol.2022.964488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory neurotransmission plays a fundamental role in the central nervous system, with about 30–50% of synaptic connections being inhibitory. The action of both inhibitory neurotransmitter, gamma-aminobutyric-acid (GABA) and glycine, mainly relies on the intracellular Cl– concentration in neurons. This is set by the interplay of the cation chloride cotransporters NKCC1 (Na+, K+, Cl– cotransporter), a main Cl– uptake transporter, and KCC2 (K+, Cl– cotransporter), the principle Cl– extruder in neurons. Accordingly, their dysfunction is associated with severe neurological, psychiatric, and neurodegenerative disorders. This has triggered great interest in understanding their regulation, with a strong focus on phosphorylation. Recent structural data by cryogenic electron microscopy provide the unique possibility to gain insight into the action of these phosphorylations. Interestingly, in KCC2, six out of ten (60%) known regulatory phospho-sites reside within a region of 134 amino acid residues (12% of the total residues) between helices α8 and α9 that lacks fixed or ordered three-dimensional structures. It thus represents a so-called intrinsically disordered region. Two further phospho-sites, Tyr903 and Thr906, are also located in a disordered region between the ß8 strand and the α8 helix. We make the case that especially the disordered region between helices α8 and α9 acts as a platform to integrate different signaling pathways and simultaneously constitute a flexible, highly dynamic linker that can survey a wide variety of distinct conformations. As each conformation can have distinct binding affinities and specificity properties, this enables regulation of [Cl–]i and thus the ionic driving force in a history-dependent way. This region might thus act as a molecular processor underlying the well described phenomenon of ionic plasticity that has been ascribed to inhibitory neurotransmission. Finally, it might explain the stunning long-range effects of mutations on phospho-sites in KCC2.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- *Correspondence: Anna-Maria Hartmann,
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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18
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Molecular Mechanisms of Epilepsy: The Role of the Chloride Transporter KCC2. J Mol Neurosci 2022; 72:1500-1515. [PMID: 35819636 DOI: 10.1007/s12031-022-02041-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 06/07/2022] [Indexed: 10/17/2022]
Abstract
Epilepsy is a neurological disease characterized by abnormal or synchronous brain activity causing seizures, which may produce convulsions, minor physical signs, or a combination of symptoms. These disorders affect approximately 65 million people worldwide, from all ages and genders. Seizures apart, epileptic patients present a high risk to develop neuropsychological comorbidities such as cognitive deficits, emotional disturbance, and psychiatric disorders, which severely impair quality of life. Currently, the treatment for epilepsy includes the administration of drugs or surgery, but about 30% of the patients treated with antiepileptic drugs develop time-dependent pharmacoresistence. Therefore, further investigation about epilepsy and its causes is needed to find new pharmacological targets and innovative therapeutic strategies. Pharmacoresistance is associated to changes in neuronal plasticity and alterations of GABAA receptor-mediated neurotransmission. The downregulation of GABA inhibitory activity may arise from a positive shift in GABAA receptor reversal potential, due to an alteration in chloride homeostasis. In this paper, we review the contribution of K+-Cl--cotransporter (KCC2) to the alterations in the Cl- gradient observed in epileptic condition, and how these alterations are coupled to the increase in the excitability.
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19
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Hui KK, Chater TE, Goda Y, Tanaka M. How Staying Negative Is Good for the (Adult) Brain: Maintaining Chloride Homeostasis and the GABA-Shift in Neurological Disorders. Front Mol Neurosci 2022; 15:893111. [PMID: 35875665 PMCID: PMC9305173 DOI: 10.3389/fnmol.2022.893111] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023] Open
Abstract
Excitatory-inhibitory (E-I) imbalance has been shown to contribute to the pathogenesis of a wide range of neurodevelopmental disorders including autism spectrum disorders, epilepsy, and schizophrenia. GABA neurotransmission, the principal inhibitory signal in the mature brain, is critically coupled to proper regulation of chloride homeostasis. During brain maturation, changes in the transport of chloride ions across neuronal cell membranes act to gradually change the majority of GABA signaling from excitatory to inhibitory for neuronal activation, and dysregulation of this GABA-shift likely contributes to multiple neurodevelopmental abnormalities that are associated with circuit dysfunction. Whilst traditionally viewed as a phenomenon which occurs during brain development, recent evidence suggests that this GABA-shift may also be involved in neuropsychiatric disorders due to the “dematuration” of affected neurons. In this review, we will discuss the cell signaling and regulatory mechanisms underlying the GABA-shift phenomenon in the context of the latest findings in the field, in particular the role of chloride cotransporters NKCC1 and KCC2, and furthermore how these regulatory processes are altered in neurodevelopmental and neuropsychiatric disorders. We will also explore the interactions between GABAergic interneurons and other cell types in the developing brain that may influence the GABA-shift. Finally, with a greater understanding of how the GABA-shift is altered in pathological conditions, we will briefly outline recent progress on targeting NKCC1 and KCC2 as a therapeutic strategy against neurodevelopmental and neuropsychiatric disorders associated with improper chloride homeostasis and GABA-shift abnormalities.
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Affiliation(s)
- Kelvin K. Hui
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, United States
- *Correspondence: Kelvin K. Hui,
| | - Thomas E. Chater
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Thomas E. Chater,
| | - Yukiko Goda
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Synapse Biology Unit, Okinawa Institute for Science and Technology Graduate University, Onna, Japan
| | - Motomasa Tanaka
- Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Japan
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20
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Zhao Y, Shen J, Wang Q, Ruiz Munevar MJ, Vidossich P, De Vivo M, Zhou M, Cao E. Structure of the human cation-chloride cotransport KCC1 in an outward-open state. Proc Natl Acad Sci U S A 2022; 119:e2109083119. [PMID: 35759661 PMCID: PMC9271165 DOI: 10.1073/pnas.2109083119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 04/25/2022] [Indexed: 12/30/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) catalyze electroneutral symport of Cl- with Na+ and/or K+ across membranes. CCCs are fundamental in cell volume homeostasis, transepithelia ion movement, maintenance of intracellular Cl- concentration, and neuronal excitability. Here, we present a cryoelectron microscopy structure of human K+-Cl- cotransporter (KCC)1 bound with the VU0463271 inhibitor in an outward-open state. In contrast to many other amino acid-polyamine-organocation transporter cousins, our first outward-open CCC structure reveals that opening the KCC1 extracellular ion permeation path does not involve hinge-bending motions of the transmembrane (TM) 1 and TM6 half-helices. Instead, rocking of TM3 and TM8, together with displacements of TM4, TM9, and a conserved intracellular loop 1 helix, underlie alternate opening and closing of extracellular and cytoplasmic vestibules. We show that KCC1 intriguingly exists in one of two distinct dimeric states via different intersubunit interfaces. Our studies provide a blueprint for understanding the mechanisms of CCCs and their inhibition by small molecule compounds.
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Affiliation(s)
- Yongxiang Zhao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Jiemin Shen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | | | | | - Marco De Vivo
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
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21
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Prael III FJ, Kim K, Du Y, Spitznagel BD, Sulikowski GA, Delpire E, Weaver CD. Discovery of Small Molecule KCC2 Potentiators Which Attenuate In Vitro Seizure-Like Activity in Cultured Neurons. Front Cell Dev Biol 2022; 10:912812. [PMID: 35813195 PMCID: PMC9263442 DOI: 10.3389/fcell.2022.912812] [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: 04/04/2022] [Accepted: 06/02/2022] [Indexed: 01/14/2023] Open
Abstract
KCC2 is a K+-Cl- cotransporter that is expressed in neurons throughout the central nervous system. Deficits in KCC2 activity have been implicated in a variety of neurological disorders, including epilepsy, chronic pain, autism spectrum disorders, and Rett syndrome. Therefore, it has been hypothesized that pharmacological potentiation of KCC2 activity could provide a treatment for these disorders. To evaluate the therapeutic potential of pharmacological KCC2 potentiation, drug-like, selective KCC2 potentiators are required. Unfortunately, the lack of such tools has greatly hampered the investigation of the KCC2 potentiation hypothesis. Herein, we describe the discovery and characterization of a new class of small-molecule KCC2 potentiator. This newly discovered class exhibits KCC2-dependent activity and a unique mechanistic profile relative to previously reported small molecules. Furthermore, we demonstrate that KCC2 potentiation by this new class of KCC2 potentiator attenuates seizure-like activity in neuronal-glial co-cultures. Together, our results provide evidence that pharmacological KCC2 potentiation, by itself, is sufficient to attenuate neuronal excitability in an in vitro model that is sensitive to anti-epileptic drugs. Our findings and chemical tools are important for evaluating the promise of KCC2 as a therapeutic target and could lay a foundation for the development of KCC2-directed therapeutics for multiple neurological disorders.
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Affiliation(s)
- Francis J. Prael III
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | - Kwangho Kim
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Yu Du
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | | | - Gary A. Sulikowski
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States,*Correspondence: C. David Weaver,
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22
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Liedtke W. Long March Toward Safe and Effective Analgesia by Enhancing Gene Expression of Kcc2: First Steps Taken. Front Mol Neurosci 2022; 15:865600. [PMID: 35645734 PMCID: PMC9137411 DOI: 10.3389/fnmol.2022.865600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
Low intraneuronal chloride in spinal cord dorsal horn pain relay neurons is critical for physiologic transmission of primary pain afferents because low intraneuronal chloride dictates whether GABA-ergic and glycin-ergic neurotransmission is inhibitory. If the neuronal chloride elevates to pathologic levels, then spinal cord primary pain relay becomes leaky and exhibits the behavioral hallmarks of pathologic pain, namely hypersensitivity and allodynia. Low chloride in spinal cord dorsal horn neurons is maintained by proper gene expression of Kcc2 and sustained physiologic function of the KCC2 chloride extruding electroneutral transporter. Peripheral nerve injury and other forms of neural injury evoke greatly diminished Kcc2 gene expression and subsequent corruption of inhibitory neurotransmission in the spinal cord dorsal horn, thus causing derailment of the gate function for pain. Here I review key discoveries that have helped us understand these fundamentals, and focus on recent insights relating to the discovery of Kcc2 gene expression enhancing compounds via compound screens in neurons. One such study characterized the kinase inhibitor, kenpaullone, more in-depth, revealing its function as a robust and long-lasting analgesic in preclinical models of nerve injury and cancer bone pain, also elucidating its mechanism of action via GSK3β inhibition, diminishing delta-catenin phosphorylation, and facilitating its nuclear transfer and subsequent enhancement of Kcc2 gene expression by de-repressing Kaiso epigenetic transcriptional regulator. Future directions re Kcc2 gene expression enhancement are discussed, namely combination with other analgesics and analgesic methods, such as spinal cord stimulation and electroacupuncture, gene therapy, and leveraging Kcc2 gene expression-enhancing nanomaterials.
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23
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Absalom NL, Liao VWY, Johannesen KMH, Gardella E, Jacobs J, Lesca G, Gokce-Samar Z, Arzimanoglou A, Zeidler S, Striano P, Meyer P, Benkel-Herrenbrueck I, Mero IL, Rummel J, Chebib M, Møller RS, Ahring PK. Gain-of-function and loss-of-function GABRB3 variants lead to distinct clinical phenotypes in patients with developmental and epileptic encephalopathies. Nat Commun 2022; 13:1822. [PMID: 35383156 PMCID: PMC8983652 DOI: 10.1038/s41467-022-29280-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 03/08/2022] [Indexed: 12/23/2022] Open
Abstract
Many patients with developmental and epileptic encephalopathies present with variants in genes coding for GABAA receptors. These variants are presumed to cause loss-of-function receptors leading to reduced neuronal GABAergic activity. Yet, patients with GABAA receptor variants have diverse clinical phenotypes and many are refractory to treatment despite the availability of drugs that enhance GABAergic activity. Here we show that 44 pathogenic GABRB3 missense variants segregate into gain-of-function and loss-of-function groups and respective patients display distinct clinical phenotypes. The gain-of-function cohort (n = 27 patients) presented with a younger age of seizure onset, higher risk of severe intellectual disability, focal seizures at onset, hypotonia, and lower likelihood of seizure freedom in response to treatment. Febrile seizures at onset are exclusive to the loss-of-function cohort (n = 47 patients). Overall, patients with GABRB3 variants that increase GABAergic activity have more severe developmental and epileptic encephalopathies. This paradoxical finding challenges our current understanding of the GABAergic system in epilepsy and how patients should be treated.
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Affiliation(s)
- Nathan L Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,School of Science, Western Sydney University, Sydney, NSW, Australia
| | - Vivian W Y Liao
- Brain and Mind Centre, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Katrine M H Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, Member of the ERN EpiCARE, The Danish Epilepsy Centre, Dianalund, Denmark.,Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Elena Gardella
- Department of Epilepsy Genetics and Personalized Treatment, Member of the ERN EpiCARE, The Danish Epilepsy Centre, Dianalund, Denmark.,Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Julia Jacobs
- Department of Neuropediatrics and Muscle Disorders, Medical Center-University of Freiburg, Freiburg, Germany.,Department of Paediatrics and Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Gaetan Lesca
- Department of Medical Genetics, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France.,Institut Neuromyogène, CNRS UMR 5310 - INSERM U1217, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Zeynep Gokce-Samar
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Alexis Arzimanoglou
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Shimriet Zeidler
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Pasquale Striano
- IRCCS Institute "Giannina Gaslini", Genova, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Pierre Meyer
- Pediatric Neurology Department, Phymedexp, Montpellier University, Inserm, CRNS, Montpellier University Hospital, Montpellier, France
| | - Ira Benkel-Herrenbrueck
- Sana-Krankenhaus Düsseldorf-Gerresheim, Academic Teaching Hospital der Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Inger-Lise Mero
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Jutta Rummel
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway
| | - Mary Chebib
- Brain and Mind Centre, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Treatment, Member of the ERN EpiCARE, The Danish Epilepsy Centre, Dianalund, Denmark. .,Department of Regional Health Research, University of Southern Denmark, Odense, Denmark.
| | - Philip K Ahring
- Brain and Mind Centre, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.
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24
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Zavalin K, Hassan A, Fu C, Delpire E, Lagrange AH. Loss of KCC2 in GABAergic Neurons Causes Seizures and an Imbalance of Cortical Interneurons. Front Mol Neurosci 2022; 15:826427. [PMID: 35370549 PMCID: PMC8966887 DOI: 10.3389/fnmol.2022.826427] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/21/2022] [Indexed: 11/24/2022] Open
Abstract
K-Cl transporter KCC2 is an important regulator of neuronal development and neuronal function at maturity. Through its canonical transporter role, KCC2 maintains inhibitory responses mediated by γ-aminobutyric acid (GABA) type A receptors. During development, late onset of KCC2 transporter activity defines the period when depolarizing GABAergic signals promote a wealth of developmental processes. In addition to its transporter function, KCC2 directly interacts with a number of proteins to regulate dendritic spine formation, cell survival, synaptic plasticity, neuronal excitability, and other processes. Either overexpression or loss of KCC2 can lead to abnormal circuit formation, seizures, or even perinatal death. GABA has been reported to be especially important for driving migration and development of cortical interneurons (IN), and we hypothesized that properly timed onset of KCC2 expression is vital to this process. To test this hypothesis, we created a mouse with conditional knockout of KCC2 in Dlx5-lineage neurons (Dlx5 KCC2 cKO), which targets INs and other post-mitotic GABAergic neurons in the forebrain starting during embryonic development. While KCC2 was first expressed in the INs of layer 5 cortex, perinatal IN migrations and laminar localization appeared to be unaffected by the loss of KCC2. Nonetheless, the mice had early seizures, failure to thrive, and premature death in the second and third weeks of life. At this age, we found an underlying change in IN distribution, including an excess number of somatostatin neurons in layer 5 and a decrease in parvalbumin-expressing neurons in layer 2/3 and layer 6. Our research suggests that while KCC2 expression may not be entirely necessary for early IN migration, loss of KCC2 causes an imbalance in cortical interneuron subtypes, seizures, and early death. More work will be needed to define the specific cellular basis for these findings, including whether they are due to abnormal circuit formation versus the sequela of defective IN inhibition.
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Affiliation(s)
- Kirill Zavalin
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Anjana Hassan
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Cary Fu
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Eric Delpire
- Department of Anesthesiology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Andre H. Lagrange
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States,Department of Neurology, Tennessee Valley Healthcare – Veterans Affairs (TVH VA), Medical Center, Nashville, TN, United States,*Correspondence: Andre H. Lagrange,
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25
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Herrmann T, Gerth M, Dittmann R, Pensold D, Ungelenk M, Liebmann L, Hübner CA. Disruption of KCC2 in Parvalbumin-Positive Interneurons Is Associated With a Decreased Seizure Threshold and a Progressive Loss of Parvalbumin-Positive Interneurons. Front Mol Neurosci 2022; 14:807090. [PMID: 35185464 PMCID: PMC8850922 DOI: 10.3389/fnmol.2021.807090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/20/2021] [Indexed: 01/05/2023] Open
Abstract
GABAA receptors are ligand-gated ion channels, which are predominantly permeable for chloride. The neuronal K-Cl cotransporter KCC2 lowers the intraneuronal chloride concentration and thus plays an important role for GABA signaling. KCC2 loss-of-function is associated with seizures and epilepsy. Here, we show that KCC2 is expressed in the majority of parvalbumin-positive interneurons (PV-INs) of the mouse brain. PV-INs receive excitatory input from principle cells and in turn control principle cell activity by perisomatic inhibition and inhibitory input from other interneurons. Upon Cre-mediated disruption of KCC2 in mice, the polarity of the GABA response of PV-INs changed from hyperpolarization to depolarization for the majority of PV-INs. Reduced excitatory postsynaptic potential-spike (E-S) coupling and increased spontaneous inhibitory postsynaptic current (sIPSC) frequencies further suggest that PV-INs are disinhibited upon disruption of KCC2. In vivo, PV-IN-specific KCC2 knockout mice display a reduced seizure threshold and develop spontaneous sometimes fatal seizures. We further found a time dependent loss of PV-INs, which was preceded by an up-regulation of pro-apoptotic genes upon disruption of KCC2.
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26
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Cherubini E, Di Cristo G, Avoli M. Dysregulation of GABAergic Signaling in Neurodevelomental Disorders: Targeting Cation-Chloride Co-transporters to Re-establish a Proper E/I Balance. Front Cell Neurosci 2022; 15:813441. [PMID: 35069119 PMCID: PMC8766311 DOI: 10.3389/fncel.2021.813441] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 11/30/2021] [Indexed: 01/01/2023] Open
Abstract
The construction of the brain relies on a series of well-defined genetically and experience- or activity -dependent mechanisms which allow to adapt to the external environment. Disruption of these processes leads to neurological and psychiatric disorders, which in many cases are manifest already early in postnatal life. GABA, the main inhibitory neurotransmitter in the adult brain is one of the major players in the early assembly and formation of neuronal circuits. In the prenatal and immediate postnatal period GABA, acting on GABAA receptors, depolarizes and excites targeted cells via an outwardly directed flux of chloride. In this way it activates NMDA receptors and voltage-dependent calcium channels contributing, through intracellular calcium rise, to shape neuronal activity and to establish, through the formation of new synapses and elimination of others, adult neuronal circuits. The direction of GABAA-mediated neurotransmission (depolarizing or hyperpolarizing) depends on the intracellular levels of chloride [Cl−]i, which in turn are maintained by the activity of the cation-chloride importer and exporter KCC2 and NKCC1, respectively. Thus, the premature hyperpolarizing action of GABA or its persistent depolarizing effect beyond the postnatal period, leads to behavioral deficits associated with morphological alterations and an excitatory (E)/inhibitory (I) imbalance in selective brain areas. The aim of this review is to summarize recent data concerning the functional role of GABAergic transmission in building up and refining neuronal circuits early in development and its dysfunction in neurodevelopmental disorders such as Autism Spectrum Disorders (ASDs), schizophrenia and epilepsy. In particular, we focus on novel information concerning the mechanisms by which alterations in cation-chloride co-transporters (CCC) generate behavioral and cognitive impairment in these diseases. We discuss also the possibility to re-establish a proper GABAA-mediated neurotransmission and excitatory (E)/inhibitory (I) balance within selective brain areas acting on CCC.
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Affiliation(s)
- Enrico Cherubini
- European Brain Research Institute (EBRI)-Rita Levi-Montalcini, Roma, Italy
- *Correspondence: Enrico Cherubini
| | - Graziella Di Cristo
- Neurosciences Department, Université de Montréal and CHU Sainte-Justine Research Center, Montreal, QC, Canada
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital and Departments of Neurology and Neurosurgery and of Physiology, McGill University, Montreal, QC, Canada
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27
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Dimitrijevic S, Jekic B, Cvjeticanin S, Tucovic A, Filipovic T, Novaković I, Ivić B, Nikolic D. KCC2 rs2297201 Gene Polymorphism Might be a Predictive Genetic Marker of Febrile Seizures. ASN Neuro 2022; 14:17590914221093257. [PMID: 35414199 PMCID: PMC9016559 DOI: 10.1177/17590914221093257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Introduction: Febrile seizures (FS) are the most common neurological
disease in childhood. The etiology of FS is the subject of numerous studies
including studies regarding genetic predisposition. Aim: The aim of
the study was to analyze the association of TRPV1 rs222747 and
KCC2 rs2297201 gene polymorphisms with the occurrence of
FS. Materials and Methods: The study included 112 patients
diagnosed with FS classified as simple febrile seizures (SFS) or complex febrile
seizures (CFS). We analyzed selected polymorphisms of KCC2 and
TRPV1 genes using the Real-time PCR method.
Results: The CT and TT genotypes of the rs2297201 polymorphism
of the KCC2 gene are significantly more common in the group of
children with FS than the control group (p = .002) as well as
the allele T of this polymorphism (p = .045). Additionally,
genotypes CT and TT of the rs2297201 polymorphism of the KCC2
gene were more frequent in the group of children with CFS compared to the
control group (p < .001). Different genotypes and alleles of
the rs222747 TRPV1 gene polymorphism were not associated with
the occurrence of febrile seizures or epilepsy, nor were associated with the
occurrence of a particular type of febrile seizure (p = .252).
Conclusion: These results indicate that the CT and TT
genotypes, as well as the T allele of rs2297201 polymorphism of the
KCC2 gene, could be a predisposing factor for the FS, as
well as the occurrence of CFS.
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Affiliation(s)
- Sanja Dimitrijevic
- Special Hospital for Cerebral Palsy and Developmental Neurology, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Biljana Jekic
- Institute of Human Genetics, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Suzana Cvjeticanin
- Institute of Human Genetics, School of Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Tamara Filipovic
- Institute for Rehabilitation, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivana Novaković
- Institute of Human Genetics, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Bojana Ivić
- University Clinic for Gynecology and Obstetrics “Narodni front”, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Dimitrije Nikolic
- University Children’s Hospital Tiršova, School of Medicine, University of Belgrade, Belgrade, Serbia
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28
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Sullivan BJ, Kipnis PA, Carter BM, Shao LR, Kadam SD. Targeting ischemia-induced KCC2 hypofunction rescues refractory neonatal seizures and mitigates epileptogenesis in a mouse model. Sci Signal 2021; 14:eabg2648. [PMID: 34752143 DOI: 10.1126/scisignal.abg2648] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Brennan J Sullivan
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Pavel A Kipnis
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Brandon M Carter
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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29
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Liu XR, Xu XX, Lin SM, Fan CY, Ye TT, Tang B, Shi YW, Su T, Li BM, Yi YH, Luo JH, Liao WP. GRIN2A Variants Associated With Idiopathic Generalized Epilepsies. Front Mol Neurosci 2021; 14:720984. [PMID: 34720871 PMCID: PMC8551482 DOI: 10.3389/fnmol.2021.720984] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/30/2021] [Indexed: 12/16/2022] Open
Abstract
Objective: The objective of this study is to explore the role of GRIN2A gene in idiopathic generalized epilepsies and the potential underlying mechanism for phenotypic variation. Methods: Whole-exome sequencing was performed in a cohort of 88 patients with idiopathic generalized epilepsies. Electro-physiological alterations of the recombinant N-methyl-D-aspartate receptors (NMDARs) containing GluN2A mutants were examined using two-electrode voltage-clamp recordings. The alterations of protein expression were detected by immunofluorescence staining and biotinylation. Previous studies reported that epilepsy related GRIN2A missense mutations were reviewed. The correlation among phenotypes, functional alterations, and molecular locations was analyzed. Results: Three novel heterozygous missense GRIN2A mutations (c.1770A > C/p.K590N, c.2636A > G/p.K879R, and c.3199C > T/p.R1067W) were identified in three unrelated cases. Electrophysiological analysis demonstrated R1067W significantly increased the current density of GluN1/GluN2A NMDARs. Immunofluorescence staining indicated GluN2A mutants had abundant distribution in the membrane and cytoplasm. Western blotting showed the ratios of surface and total expression of the three GluN2A-mutants were significantly increased comparing to the wild type. Further analysis on the reported missense mutations demonstrated that mutations with severe gain-of-function were associated with epileptic encephalopathy, while mutations with mild gain of function were associated with mild phenotypes, suggesting a quantitative correlation between gain-of-function and phenotypic severity. The mutations located around transmembrane domains were more frequently associated with severe phenotypes and absence seizure-related mutations were mostly located in carboxyl-terminal domain, suggesting molecular sub-regional effects. Significance: This study revealed GRIN2A gene was potentially a candidate pathogenic gene of idiopathic generalized epilepsies. The functional quantitative correlation and the molecular sub-regional implication of mutations helped in explaining the relatively mild clinical phenotypes and incomplete penetrance associated with GRIN2A variants.
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Affiliation(s)
- Xiao-Rong Liu
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xing-Xing Xu
- Department of Physiology, Wenzhou Medical University, Wenzhou, China
| | - Si-Mei Lin
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Cui-Ying Fan
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Ting-Ting Ye
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bin Tang
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yi-Wu Shi
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Tao Su
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bing-Mei Li
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jian-Hong Luo
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei-Ping Liao
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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Yeo M, Chen Y, Jiang C, Chen G, Wang K, Chandra S, Bortsov A, Lioudyno M, Zeng Q, Wang P, Wang Z, Busciglio J, Ji RR, Liedtke W. Repurposing cancer drugs identifies kenpaullone which ameliorates pathologic pain in preclinical models via normalization of inhibitory neurotransmission. Nat Commun 2021; 12:6208. [PMID: 34707084 PMCID: PMC8551327 DOI: 10.1038/s41467-021-26270-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Inhibitory GABA-ergic neurotransmission is fundamental for the adult vertebrate central nervous system and requires low chloride concentration in neurons, maintained by KCC2, a neuroprotective ion transporter that extrudes intracellular neuronal chloride. To identify Kcc2 gene expression‑enhancing compounds, we screened 1057 cell growth-regulating compounds in cultured primary cortical neurons. We identified kenpaullone (KP), which enhanced Kcc2/KCC2 expression and function in cultured rodent and human neurons by inhibiting GSK3ß. KP effectively reduced pathologic pain-like behavior in mouse models of nerve injury and bone cancer. In a nerve-injury pain model, KP restored Kcc2 expression and GABA-evoked chloride reversal potential in the spinal cord dorsal horn. Delta-catenin, a phosphorylation-target of GSK3ß in neurons, activated the Kcc2 promoter via KAISO transcription factor. Transient spinal over-expression of delta-catenin mimicked KP analgesia. Our findings of a newly repurposed compound and a novel, genetically-encoded mechanism that each enhance Kcc2 gene expression enable us to re-normalize disrupted inhibitory neurotransmission through genetic re-programming.
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Affiliation(s)
- Michele Yeo
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Yong Chen
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Changyu Jiang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Gang Chen
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Kaiyuan Wang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Sharat Chandra
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Andrey Bortsov
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Maria Lioudyno
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Qian Zeng
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Peng Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Zilong Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Jorge Busciglio
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Ru-Rong Ji
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
| | - Wolfgang Liedtke
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
- Duke Neurology Clinics for Headache, Head-Pain and Trigeminal Sensory Disorders, Duke University Medical Center, Durham, NC, USA.
- Duke Anesthesiology Clinics for Innovative Pain Therapy, Duke University Medical Center, Durham, NC, USA.
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31
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Portioli C, Ruiz Munevar MJ, De Vivo M, Cancedda L. Cation-coupled chloride cotransporters: chemical insights and disease implications. TRENDS IN CHEMISTRY 2021; 3:832-849. [PMID: 34604727 PMCID: PMC8461084 DOI: 10.1016/j.trechm.2021.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cation-coupled chloride cotransporters (CCCs) modulate the transport of sodium and/or potassium cations coupled with chloride anions across the cell membrane. CCCs thus help regulate intracellular ionic concentration and consequent cell volume homeostasis. This has been largely exploited in the past to develop diuretic drugs that act on CCCs expressed in the kidney. However, a growing wealth of evidence has demonstrated that CCCs are also critically involved in a great variety of other pathologies, motivating most recent drug discovery programs targeting CCCs. Here, we examine the structure–function relationship of CCCs. By linking recent high-resolution cryogenic electron microscopy (cryo-EM) data with older biochemical/functional studies on CCCs, we discuss the mechanistic insights and opportunities to design selective CCC modulators to treat diverse pathologies. The structural topology and function of all cation-coupled chloride cotransporters (CCCs) have been continuously investigated over the past 40 years, with great progress also thanks to the recent cryogenic electron microscopy (cryo-EM) resolution of the structures of five CCCs. In particular, such studies have clarified the structure–function relationship for the Na-K-Cl cotransporter NKCC1 and K-Cl cotransporters KCC1–4. The constantly growing evidence of the crucial involvement of CCCs in physiological and various pathological conditions, as well as the evidence of their wide expression in diverse body tissues, has promoted CCCs as targets for the discovery and development of new, safer, and more selective/effective drugs for a plethora of pathologies. Post-translational modification anchor points on the structure of CCCs may offer alternative strategies for small molecule drug discovery.
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Affiliation(s)
- Corinne Portioli
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | | | - Marco De Vivo
- Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Dulbecco Telethon Institute, Via Varese 16b, 00185 Rome, Italy
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Kovesdi E, Ripszam R, Postyeni E, Horvath EB, Kelemen A, Fabos B, Farkas V, Hadzsiev K, Sumegi K, Magyari L, Moreno PG, Bauer P, Melegh B. Whole Exome Sequencing in a Series of Patients with a Clinical Diagnosis of Tuberous Sclerosis Not Confirmed by Targeted TSC1/TSC2 Sequencing. Genes (Basel) 2021; 12:genes12091401. [PMID: 34573383 PMCID: PMC8471884 DOI: 10.3390/genes12091401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/05/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Approximately fifteen percent of patients with tuberous sclerosis complex (TSC) phenotype do not have any genetic disease-causing mutations which could be responsible for the development of TSC. The lack of a proper diagnosis significantly affects the quality of life for these patients and their families. METHODS The aim of our study was to use Whole Exome Sequencing (WES) in order to identify the genes responsible for the phenotype of nine patients with clinical signs of TSC, but without confirmed tuberous sclerosis complex 1/ tuberous sclerosis complex 2 (TSC1/TSC2) mutations using routine molecular genetic diagnostic tools. RESULTS We found previously overlooked heterozygous nonsense mutations in TSC1, and a heterozygous intronic variant in TSC2. In one patient, two heterozygous missense variants were found in polycystic kidney and hepatic disease 1 (PKHD1), confirming polycystic kidney disease type 4. A heterozygous missense mutation in solute carrier family 12 member 5 (SLC12A5) was found in one patient, which is linked to cause susceptibility to idiopathic generalized epilepsy type 14. Heterozygous nonsense variant ring finger protein 213 (RNF213) was identified in one patient, which is associated with susceptibility to Moyamoya disease type 2. In the remaining three patients WES could not reveal any variants clinically relevant to the described phenotypes. CONCLUSION Patients without appropriate diagnosis due to the lack of sensitivity of the currently used routine diagnostic methods can significantly profit from the wider application of next generation sequencing technologies in order to identify genes and variants responsible for their symptoms.
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Affiliation(s)
- Erzsebet Kovesdi
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
- Molecular Neuroendocrinology Research Group, Institute of Physiology, Center for Neuroscience, Szentagothai Research Center, Medical School, University of Pecs, 7624 Pecs, Hungary
- Correspondence:
| | - Reka Ripszam
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
| | - Etelka Postyeni
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
| | - Emese Beatrix Horvath
- Department of Medical Genetics, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary;
| | - Anna Kelemen
- National Institute of Clinical Neurosciences, 1145 Budapest, Hungary;
| | - Beata Fabos
- Somogy County Mor Kaposi Teaching Hospital, 7400 Kaposvar, Hungary;
| | - Viktor Farkas
- Department of Pediatrics, Faculty of Medicine, Semmelweis University, 1085-Budapest, Hungary;
| | - Kinga Hadzsiev
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
| | - Katalin Sumegi
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
- Departments of Biochemistry and Medical Chemistry, Medical School, University of Pecs, 7624 Pecs, Hungary
| | - Lili Magyari
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
| | | | - Peter Bauer
- CENTOGENE GmbH, 18055 Rostock, Germany; (P.B.); (P.G.M.)
| | - Bela Melegh
- Department of Medical Genetics, Medical School, Szentagothai Research Center, University of Pecs, 7624 Pecs, Hungary; (R.R.); (E.P.); (K.H.); (K.S.); (L.M.); (B.M.)
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Abstract
The presence of unprovoked, recurrent seizures, particularly when drug resistant and associated with cognitive and behavioral deficits, warrants investigation for an underlying genetic cause. This article provides an overview of the major classes of genes associated with epilepsy phenotypes divided into functional categories along with the recommended work-up and therapeutic considerations. Gene discovery in epilepsy supports counseling and anticipatory guidance but also opens the door for precision medicine guiding therapy with a focus on those with disease-modifying effects.
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Affiliation(s)
- Luis A Martinez
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Yi-Chen Lai
- Department of Pediatrics, Section of Pediatric Critical Care Medicine, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - J Lloyd Holder
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Anne E Anderson
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA.
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34
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Chi G, Ebenhoch R, Man H, Tang H, Tremblay LE, Reggiano G, Qiu X, Bohstedt T, Liko I, Almeida FG, Garneau AP, Wang D, McKinley G, Moreau CP, Bountra KD, Abrusci P, Mukhopadhyay SMM, Fernandez‐Cid A, Slimani S, Lavoie JL, Burgess‐Brown NA, Tehan B, DiMaio F, Jazayeri A, Isenring P, Robinson CV, Dürr KL. Phospho-regulation, nucleotide binding and ion access control in potassium-chloride cotransporters. EMBO J 2021; 40:e107294. [PMID: 34031912 PMCID: PMC8280820 DOI: 10.15252/embj.2020107294] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/29/2021] [Accepted: 04/11/2021] [Indexed: 11/26/2022] Open
Abstract
Potassium-coupled chloride transporters (KCCs) play crucial roles in regulating cell volume and intracellular chloride concentration. They are characteristically inhibited under isotonic conditions via phospho-regulatory sites located within the cytoplasmic termini. Decreased inhibitory phosphorylation in response to hypotonic cell swelling stimulates transport activity, and dysfunction of this regulatory process has been associated with various human diseases. Here, we present cryo-EM structures of human KCC3b and KCC1, revealing structural determinants for phospho-regulation in both N- and C-termini. We show that phospho-mimetic KCC3b is arrested in an inward-facing state in which intracellular ion access is blocked by extensive contacts with the N-terminus. In another mutant with increased isotonic transport activity, KCC1Δ19, this interdomain interaction is absent, likely due to a unique phospho-regulatory site in the KCC1 N-terminus. Furthermore, we map additional phosphorylation sites as well as a previously unknown ATP/ADP-binding pocket in the large C-terminal domain and show enhanced thermal stabilization of other CCCs by adenine nucleotides. These findings provide fundamentally new insights into the complex regulation of KCCs and may unlock innovative strategies for drug development.
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Affiliation(s)
- Gamma Chi
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Rebecca Ebenhoch
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
MedChem, Boehringer Ingelheim Pharma GmbH & Co. KGBiberachGermany
| | - Henry Man
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Haiping Tang
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Laurence E Tremblay
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | | | - Xingyu Qiu
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Tina Bohstedt
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | | | - Alexandre P Garneau
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Dong Wang
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Gavin McKinley
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Christophe P Moreau
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Present address:
Celonic AGBaselGermany
| | | | - Patrizia Abrusci
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Shubhashish M M Mukhopadhyay
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Alejandra Fernandez‐Cid
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Samira Slimani
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Julie L Lavoie
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Nicola A Burgess‐Brown
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | - Frank DiMaio
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | | | - Paul Isenring
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Carol V Robinson
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Katharina L Dürr
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- OMass Therapeutics, Ltd.OxfordUK
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Abstract
Reflex seizures (RS) are epileptic events that are objectively and consistently elicited in response to a specific afferent stimulus or by an activity of the patient. The specific stimulus can be a variety of heterogenous intrinsic or extrinsic factors, ranging from the simple to the complex, such as flashing lights or reading a book. These seizures can take a variety of forms, comprising either general or focal onset, with or without secondary generalization. Reflex epilepsies (RE) are classified as a specific syndrome in which all epileptic seizures are precipitated by sensory stimuli. The few designated RE include idiopathic photosensitive occipital lobe epilepsy, other visual sensitive epilepsies, primary reading epilepsy, and startle epilepsy. RS that occurs within other focal or generalized epilepsy syndromes that are associated with distinct spontaneous seizures are classified by the overarching seizure type. Most patients experience spontaneous seizures along with their provoked events. RS originate from stimulation of functional anatomic networks normally functioning for physiological activities, that overlap or coincide with regions of cortical hyperexcitability. Generalized RS typically occur within the setting of IGEs and should be considered as focal seizures with quick secondary generalization via cortico-cortical or cortico-reticular pathways. In aggregate, activation of a critical neuronal mass, supported and sustained by cortico-subcortical and thalamocortical pathways eventually result in a seizure. Treatment includes antiseizure medication, commonly valproate or levetiracetam, along with lifestyle modifications, and when amenable, surgical intervention. High clinical suspicion and careful history taking must be employed in all epilepsy patients to identify reflex triggers.
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Affiliation(s)
- Samrina Hanif
- 1Department of Neurology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV 25701, USA
| | - Shane T Musick
- 2Department of Neurosurgery, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV 25701, USA
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36
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Heron SE, Regan BM, Harris RV, Gardner AE, Coleman MJ, Bennett MF, Grinton BE, Helbig KL, Sperling MR, Haut S, Geller EB, Widdess-Walsh P, Pelekanos JT, Bahlo M, Petrovski S, Heinzen EL, Hildebrand MS, Corbett MA, Scheffer IE, Gécz J, Berkovic SF. Association of SLC32A1 Missense Variants With Genetic Epilepsy With Febrile Seizures Plus. Neurology 2021; 96:e2251-e2260. [PMID: 34038384 DOI: 10.1212/wnl.0000000000011855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/05/2021] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the causative gene in a large unsolved family with genetic epilepsy with febrile seizures plus (GEFS+), we sequenced the genomes of family members, and then determined the contribution of the identified gene to the pathogenicity of epilepsies by examining sequencing data from 2,772 additional patients. METHODS We performed whole genome sequencing of 3 members of a GEFS+ family. Subsequently, whole exome sequencing data from 1,165 patients with epilepsy from the Epi4K dataset and 1,329 Australian patients with epilepsy from the Epi25 dataset were interrogated. Targeted resequencing was performed on 278 patients with febrile seizures or GEFS+ phenotypes. Variants were validated and familial segregation examined by Sanger sequencing. RESULTS Eight previously unreported missense variants were identified in SLC32A1, coding for the vesicular inhibitory amino acid cotransporter VGAT. Two variants cosegregated with the phenotype in 2 large GEFS+ families containing 8 and 10 affected individuals, respectively. Six further variants were identified in smaller families with GEFS+ or idiopathic generalized epilepsy (IGE). CONCLUSION Missense variants in SLC32A1 cause GEFS+ and IGE. These variants are predicted to alter γ-aminobutyric acid (GABA) transport into synaptic vesicles, leading to altered neuronal inhibition. Examination of further epilepsy cohorts will determine the full genotype-phenotype spectrum associated with SLC32A1 variants.
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Affiliation(s)
- Sarah E Heron
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Brigid M Regan
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Rebekah V Harris
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Alison E Gardner
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Matthew J Coleman
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Mark F Bennett
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Bronwyn E Grinton
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Katherine L Helbig
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Michael R Sperling
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Sheryl Haut
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Eric B Geller
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Peter Widdess-Walsh
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - James T Pelekanos
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Melanie Bahlo
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Slavé Petrovski
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Erin L Heinzen
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Michael S Hildebrand
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Mark A Corbett
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Ingrid E Scheffer
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Jozef Gécz
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia.
| | - Samuel F Berkovic
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
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37
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Smirnova EY, Sinyak DS, Chizhov AV, Zaitsev AV. Age-Dependent Generation of Epileptiform
Activity
in the 4-Aminopyridine Model with Slices of the Rat Entorhinal Cortex. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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38
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Delpire E. Advances in the development of novel compounds targeting cation-chloride cotransporter physiology. Am J Physiol Cell Physiol 2021; 320:C324-C340. [PMID: 33356948 PMCID: PMC8294628 DOI: 10.1152/ajpcell.00566.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 01/05/2023]
Abstract
For about half a century, the pharmacology of electroneutral cation-chloride cotransporters has been dominated by a few drugs that are widely used in clinical medicine. Because these diuretic drugs are so good at what they do, there has been little incentive in expanding their pharmacology. The increasing realization that cation-chloride cotransporters are involved in many other key physiological processes and the knowledge that different tissues express homologous proteins with matching transport functions have rekindled interest in drug discovery. This review summarizes the methods available to assess the function of these transporters and describe the multiple efforts that have made to identify new compounds. We describe multiple screens targeting KCC2 function and one screen designed to find compounds that discriminate between NKCC1 and NKCC2. Two of the KCC2 screens identified new inhibitors that are 3-4 orders of magnitude more potent than furosemide. Additional screens identified compounds that purportedly increase cell surface expression of the cotransporter, as well as several FDA-approved drugs that increase KCC2 transcription and expression. The technical details of each screen biased them toward specific processes in the life cycle of the transporter, making these efforts independent and complementary. In addition, each drug discovery effort contributes to our understanding of the biology of the cotransporters.
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Affiliation(s)
- Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee
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39
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Virtanen MA, Uvarov P, Mavrovic M, Poncer JC, Kaila K. The Multifaceted Roles of KCC2 in Cortical Development. Trends Neurosci 2021; 44:378-392. [PMID: 33640193 DOI: 10.1016/j.tins.2021.01.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
KCC2, best known as the neuron-specific chloride-extruder that sets the strength and polarity of GABAergic currents during neuronal maturation, is a multifunctional molecule that can regulate cytoskeletal dynamics via its C-terminal domain (CTD). We describe the molecular and cellular mechanisms involved in the multiple functions of KCC2 and its splice variants, ranging from developmental apoptosis and the control of early network events to the formation and plasticity of cortical dendritic spines. The versatility of KCC2 actions at the cellular and subcellular levels is also evident in mature neurons during plasticity, disease, and aging. Thus, KCC2 has emerged as one of the most important molecules that shape the overall neuronal phenotype.
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Affiliation(s)
- Mari A Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Martina Mavrovic
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland; Department of Molecular Medicine, University of Oslo, 0372 Oslo, Norway
| | - Jean Christophe Poncer
- INSERM, UMRS 1270, 75005 Paris, France; Sorbonne Université, 75005 Paris, France; Institut du Fer à Moulin, 75005 Paris, France
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland.
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40
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Zhang S, Zhou J, Zhang Y, Liu T, Friedel P, Zhuo W, Somasekharan S, Roy K, Zhang L, Liu Y, Meng X, Deng H, Zeng W, Li G, Forbush B, Yang M. The structural basis of function and regulation of neuronal cotransporters NKCC1 and KCC2. Commun Biol 2021; 4:226. [PMID: 33597714 PMCID: PMC7889885 DOI: 10.1038/s42003-021-01750-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 01/22/2021] [Indexed: 11/08/2022] Open
Abstract
NKCC and KCC transporters mediate coupled transport of Na++K++Cl- and K++Cl- across the plasma membrane, thus regulating cell Cl- concentration and cell volume and playing critical roles in transepithelial salt and water transport and in neuronal excitability. The function of these transporters has been intensively studied, but a mechanistic understanding has awaited structural studies of the transporters. Here, we present the cryo-electron microscopy (cryo-EM) structures of the two neuronal cation-chloride cotransporters human NKCC1 (SLC12A2) and mouse KCC2 (SLC12A5), along with computational analysis and functional characterization. These structures highlight essential residues in ion transport and allow us to propose mechanisms by which phosphorylation regulates transport activity.
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Affiliation(s)
- Sensen Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jun Zhou
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuebin Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Tianya Liu
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Perrine Friedel
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Wei Zhuo
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Suma Somasekharan
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Kasturi Roy
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Laixing Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yang Liu
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xianbin Meng
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wenwen Zeng
- Center for Life Sciences, Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China
| | - Guohui Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
| | - Biff Forbush
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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41
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Pizzamiglio L, Focchi E, Cambria C, Ponzoni L, Ferrara S, Bifari F, Desiato G, Landsberger N, Murru L, Passafaro M, Sala M, Matteoli M, Menna E, Antonucci F. The DNA repair protein ATM as a target in autism spectrum disorder. JCI Insight 2021; 6:133654. [PMID: 33373327 PMCID: PMC7934840 DOI: 10.1172/jci.insight.133654] [Citation(s) in RCA: 9] [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: 11/02/2019] [Accepted: 12/16/2020] [Indexed: 12/20/2022] Open
Abstract
Impairment of the GABAergic system has been reported in epilepsy, autism, attention deficit hyperactivity disorder, and schizophrenia. We recently demonstrated that ataxia telangiectasia mutated (ATM) directly shapes the development of the GABAergic system. Here, we show for the first time to our knowledge how the abnormal expression of ATM affects the pathological condition of autism. We exploited 2 different animal models of autism, the methyl CpG binding protein 2-null (Mecp2y/-) mouse model of Rett syndrome and mice prenatally exposed to valproic acid, and found increased ATM levels. Accordingly, treatment with the specific ATM kinase inhibitor KU55933 (KU) normalized molecular, functional, and behavioral defects in these mouse models, such as (a) delayed GABAergic development, (b) hippocampal hyperexcitability, (c) low cognitive performances, and (d) social impairments. Mechanistically, we demonstrate that KU administration to WT hippocampal neurons leads to (a) higher early growth response 4 activity on Kcc2b promoter, (b) increased expression of Mecp2, and (c) potentiated GABA transmission. These results provide evidence and molecular substrates for the pharmacological development of ATM inhibition in autism spectrum disorders.
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Affiliation(s)
- Lara Pizzamiglio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | - Elisa Focchi
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | - Clara Cambria
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | | | - Silvia Ferrara
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | - Francesco Bifari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | - Genni Desiato
- Humanitas Clinical and Research Center – IRCCS, Rozzano, Milan, Italy
| | - Nicoletta Landsberger
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
| | - Luca Murru
- Institute of Neuroscience, IN-CNR, Milan, Italy
| | | | | | - Michela Matteoli
- Institute of Neuroscience, IN-CNR, Milan, Italy
- Humanitas Clinical and Research Center – IRCCS, Rozzano, Milan, Italy
| | - Elisabetta Menna
- Institute of Neuroscience, IN-CNR, Milan, Italy
- Humanitas Clinical and Research Center – IRCCS, Rozzano, Milan, Italy
| | - Flavia Antonucci
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), University of Milan, Milan, Italy
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42
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Hartmann AM, Fu L, Ziegler C, Winklhofer M, Nothwang HG. Structural changes in the extracellular loop 2 of the murine KCC2 potassium chloride cotransporter modulate ion transport. J Biol Chem 2021; 296:100793. [PMID: 34019872 PMCID: PMC8191313 DOI: 10.1016/j.jbc.2021.100793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 01/22/2023] Open
Abstract
K+-Cl- cotransporters (KCCs) play important roles in physiological processes such as inhibitory neurotransmission and cell-volume regulation. KCCs exhibit significant variations in K+ affinities, yet recent atomic structures demonstrated that K+- and Cl--binding sites are highly conserved, raising the question of whether additional structural elements may contribute to ion coordination. The termini and the large extracellular domain (ECD) of KCCs exhibit only low sequence identity and were already discussed as modulators of transport activity. Here, we used the extracellular loop 2 (EL2) that links transmembrane helices (TMs) 3 and 4, as a mechanism to modulate ECD folding. We compared consequences of point mutations in the K+-binding site on the function of WT KCC2 and in a KCC2 variant, in which EL2 was structurally altered by insertion of a IFYPYDVPDYAGYPYDVPDYAGSYPYDVPDYAAHAAA (3xHA) tag (36 amino acids). In WT KCC2, individual mutations of five residues in the K+-binding site resulted in a 2- to 3-fold decreased transport rate. However, the same mutations in the KCC2 variant with EL2 structurally altered by insertion of a 3xHA tag had no effect on transport activity. Homology models of mouse KCC2 with the 3xHA tag inserted into EL2 using ab initio prediction were generated. The models suggest subtle conformational changes occur in the ECD upon EL2 modification. These data suggest that a conformational change in the ECD, for example, by interaction with EL2, might be an elegant way to modulate the K+ affinity of the different isoforms in the KCC subfamily.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
| | - Lifei Fu
- Biophysics II, Biophysics II-Structural Biology, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Regensburg, Germany
| | - Christine Ziegler
- Biophysics II, Biophysics II-Structural Biology, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Regensburg, Germany
| | - Michael Winklhofer
- Institute for Biology and Environmental Sciences IBU, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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43
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Xie Y, Chang S, Zhao C, Wang F, Liu S, Wang J, Delpire E, Ye S, Guo J. Structures and an activation mechanism of human potassium-chloride cotransporters. SCIENCE ADVANCES 2020; 6:eabc5883. [PMID: 33310850 PMCID: PMC7732191 DOI: 10.1126/sciadv.abc5883] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 10/21/2020] [Indexed: 05/07/2023]
Abstract
Potassium-chloride cotransporters KCC1 to KCC4 mediate the coupled export of potassium and chloride across the plasma membrane and play important roles in cell volume regulation, auditory system function, and γ-aminobutyric acid (GABA) and glycine-mediated inhibitory neurotransmission. Here, we present 2.9- to 3.6-Å resolution structures of full-length human KCC2, KCC3, and KCC4. All three KCCs adopt a similar overall architecture, a domain-swap dimeric assembly, and an inward-facing conformation. The structural and functional studies reveal that one unexpected N-terminal peptide binds at the cytosolic facing cavity and locks KCC2 and KCC4 at an autoinhibition state. The C-terminal domain (CTD) directly interacts with the N-terminal inhibitory peptide, and the relative motions between the CTD and the transmembrane domain (TMD) suggest that CTD regulates KCCs' activities by adjusting the autoinhibitory effect. These structures provide the first glimpse of full-length structures of KCCs and an autoinhibition mechanism among the amino acid-polyamine-organocation transporter superfamily.
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Affiliation(s)
- Yuan Xie
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Shenghai Chang
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Center of Cryo Electron Microscopy, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Cheng Zhao
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Feng Wang
- Wuxi Biortus Biosciences Co. Ltd., 6 Dongsheng West Road, Jiangyin, 214437, China
| | - Si Liu
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Jin Wang
- Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Sheng Ye
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiangtao Guo
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310016, China
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44
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Chi X, Li X, Chen Y, Zhang Y, Su Q, Zhou Q. Cryo-EM structures of the full-length human KCC2 and KCC3 cation-chloride cotransporters. Cell Res 2020; 31:482-484. [PMID: 33199848 PMCID: PMC8182806 DOI: 10.1038/s41422-020-00437-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/15/2020] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ximin Chi
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Xiaorong Li
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.,School of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yun Chen
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Yuanyuan Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Qiang Su
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Qiang Zhou
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China. .,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
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45
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Reh R, Williams LJ, Todd RM, Ward LM. Warped rhythms: Epileptic activity during critical periods disrupts the development of neural networks for human communication. Behav Brain Res 2020; 399:113016. [PMID: 33212087 DOI: 10.1016/j.bbr.2020.113016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 12/27/2022]
Abstract
It is well established that temporal lobe epilepsy-the most common and well-studied form of epilepsy-can impair communication by disrupting social-emotional and language functions. In pediatric epilepsy, where seizures co-occur with the development of critical brain networks, age of onset matters: The earlier in life seizures begin, the worse the disruption in network establishment, resulting in academic hardship and social isolation. Yet, little is known about the processes by which epileptic activity disrupts developing human brain networks. Here we take a synthetic perspective-reviewing a range of research spanning studies on molecular and oscillatory processes to those on the development of large-scale functional networks-in support of a novel model of how such networks can be disrupted by epilepsy. We seek to bridge the gap between research on molecular processes, on the development of human brain circuitry, and on clinical outcomes to propose a model of how epileptic activity disrupts brain development.
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Affiliation(s)
- Rebecca Reh
- University of British Columbia, Department of Psychology, 2136 West Mall, Vancouver BC V6T 1Z4, Canada
| | - Lynne J Williams
- BC Children's Hospital MRI Research Facility, 4480 Oak Street, Vancouver, BC V6H 0B3, Canada
| | - Rebecca M Todd
- University of British Columbia, Department of Psychology, 2136 West Mall, Vancouver BC V6T 1Z4, Canada; University of British Columbia, Djavad Mowafaghian Centre for Brain Health, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
| | - Lawrence M Ward
- University of British Columbia, Department of Psychology, 2136 West Mall, Vancouver BC V6T 1Z4, Canada; University of British Columbia, Djavad Mowafaghian Centre for Brain Health, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
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46
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Delmotte Q, Hamze M, Medina I, Buhler E, Zhang J, Belgacem YH, Porcher C. Smoothened receptor signaling regulates the developmental shift of GABA polarity in rat somatosensory cortex. J Cell Sci 2020; 133:jcs247700. [PMID: 32989040 PMCID: PMC7595691 DOI: 10.1242/jcs.247700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/12/2020] [Indexed: 02/05/2023] Open
Abstract
Sonic hedgehog (Shh) and its patched-smoothened receptor complex control a variety of functions in the developing central nervous system, such as neural cell proliferation and differentiation. Recently, Shh signaling components have been found to be expressed at the synaptic level in the postnatal brain, suggesting a potential role in the regulation of synaptic transmission. Using in utero electroporation of constitutively active and negative-phenotype forms of the Shh signal transducer smoothened (Smo), we studied the role of Smo signaling in the development and maturation of GABAergic transmission in the somatosensory cortex. Our results show that enhancing Smo activity during development accelerates the shift from depolarizing to hyperpolarizing GABA in a manner dependent on functional expression of potassium-chloride cotransporter type 2 (KCC2, also known as SLC12A5). On the other hand, blocking Smo activity maintains the GABA response in a depolarizing state in mature cortical neurons, resulting in altered chloride homeostasis and increased seizure susceptibility. This study reveals unexpected functions of Smo signaling in the regulation of chloride homeostasis, through control of KCC2 cell-surface stability, and the timing of the GABA excitatory-to-inhibitory shift in brain maturation.
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Affiliation(s)
- Quentin Delmotte
- Aix-Marseille University, Parc Scientifique de Luminy, 13273, Marseille, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Mira Hamze
- Aix-Marseille University, Parc Scientifique de Luminy, 13273, Marseille, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Igor Medina
- Aix-Marseille University, Parc Scientifique de Luminy, 13273, Marseille, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Emmanuelle Buhler
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- Plateforme Post-Génomique, INMED, 13273 Marseille, France
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - Yesser H Belgacem
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Christophe Porcher
- Aix-Marseille University, Parc Scientifique de Luminy, 13273, Marseille, France
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, Marseille, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
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Genetic Landscape of Common Epilepsies: Advancing towards Precision in Treatment. Int J Mol Sci 2020; 21:ijms21207784. [PMID: 33096746 PMCID: PMC7589654 DOI: 10.3390/ijms21207784] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
Epilepsy, a neurological disease characterized by recurrent seizures, is highly heterogeneous in nature. Based on the prevalence, epilepsy is classified into two types: common and rare epilepsies. Common epilepsies affecting nearly 95% people with epilepsy, comprise generalized epilepsy which encompass idiopathic generalized epilepsy like childhood absence epilepsy, juvenile myoclonic epilepsy, juvenile absence epilepsy and epilepsy with generalized tonic-clonic seizure on awakening and focal epilepsy like temporal lobe epilepsy and cryptogenic focal epilepsy. In 70% of the epilepsy cases, genetic factors are responsible either as single genetic variant in rare epilepsies or multiple genetic variants acting along with different environmental factors as in common epilepsies. Genetic testing and precision treatment have been developed for a few rare epilepsies and is lacking for common epilepsies due to their complex nature of inheritance. Precision medicine for common epilepsies require a panoramic approach that incorporates polygenic background and other non-genetic factors like microbiome, diet, age at disease onset, optimal time for treatment and other lifestyle factors which influence seizure threshold. This review aims to comprehensively present a state-of-art review of all the genes and their genetic variants that are associated with all common epilepsy subtypes. It also encompasses the basis of these genes in the epileptogenesis. Here, we discussed the current status of the common epilepsy genetics and address the clinical application so far on evidence-based markers in prognosis, diagnosis, and treatment management. In addition, we assessed the diagnostic predictability of a few genetic markers used for disease risk prediction in individuals. A combination of deeper endo-phenotyping including pharmaco-response data, electro-clinical imaging, and other clinical measurements along with genetics may be used to diagnose common epilepsies and this marks a step ahead in precision medicine in common epilepsies management.
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Murillo-de-Ozores AR, Chávez-Canales M, de Los Heros P, Gamba G, Castañeda-Bueno M. Physiological Processes Modulated by the Chloride-Sensitive WNK-SPAK/OSR1 Kinase Signaling Pathway and the Cation-Coupled Chloride Cotransporters. Front Physiol 2020; 11:585907. [PMID: 33192599 PMCID: PMC7606576 DOI: 10.3389/fphys.2020.585907] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/29/2020] [Indexed: 12/15/2022] Open
Abstract
The role of Cl– as an intracellular signaling ion has been increasingly recognized in recent years. One of the currently best described roles of Cl– in signaling is the modulation of the With-No-Lysine (K) (WNK) – STE20-Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive Kinase 1 (OSR1) – Cation-Coupled Cl–Cotransporters (CCCs) cascade. Binding of a Cl– anion to the active site of WNK kinases directly modulates their activity, promoting their inhibition. WNK activation due to Cl– release from the binding site leads to phosphorylation and activation of SPAK/OSR1, which in turn phosphorylate the CCCs. Phosphorylation by WNKs-SPAK/OSR1 of the Na+-driven CCCs (mediating ions influx) promote their activation, whereas that of the K+-driven CCCs (mediating ions efflux) promote their inhibition. This results in net Cl– influx and feedback inhibition of WNK kinases. A wide variety of alterations to this pathway have been recognized as the cause of several human diseases, with manifestations in different systems. The understanding of WNK kinases as Cl– sensitive proteins has allowed us to better understand the mechanistic details of regulatory processes involved in diverse physiological phenomena that are reviewed here. These include cell volume regulation, potassium sensing and intracellular signaling in the renal distal convoluted tubule, and regulation of the neuronal response to the neurotransmitter GABA.
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Affiliation(s)
- Adrián Rafael Murillo-de-Ozores
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Chávez-Canales
- Unidad de Investigación UNAM-INC, Instituto Nacional de Cardiología Ignacio Chávez and Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Paola de Los Heros
- Unidad de Investigación UNAM-INC, Research Division, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gerardo Gamba
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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Meor Azlan NF, Zhang J. Role of the Cation-Chloride-Cotransporters in Cardiovascular Disease. Cells 2020; 9:E2293. [PMID: 33066544 PMCID: PMC7602155 DOI: 10.3390/cells9102293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/08/2020] [Accepted: 10/14/2020] [Indexed: 02/05/2023] Open
Abstract
The SLC12 family of cation-chloride-cotransporters (CCCs) is comprised of potassium chloride cotransporters (KCCs), which mediate Cl- extrusion and sodium-potassium chloride cotransporters (N[K]CCs), which mediate Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. The functions of CCCs influence a variety of physiological processes, many of which overlap with the pathophysiology of cardiovascular disease. Although not all of the cotransporters have been linked to Mendelian genetic disorders, recent studies have provided new insights into their functional role in vascular and renal cells in addition to their contribution to cardiovascular diseases. Particularly, an imbalance in potassium levels promotes the pathogenesis of atherosclerosis and disturbances in sodium homeostasis are one of the causes of hypertension. Recent findings suggest hypothalamic signaling as a key signaling pathway in the pathophysiology of hypertension. In this review, we summarize and discuss the role of CCCs in cardiovascular disease with particular emphasis on knowledge gained in recent years on NKCCs and KCCs.
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Affiliation(s)
- Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, Hatherly Laboratories, University of Exeter, Exeter EX4 4PS, UK;
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, Hatherly Laboratories, University of Exeter, Exeter EX4 4PS, UK;
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen 361004, Fujian, China
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Neurobiological Mechanisms of Autism Spectrum Disorder and Epilepsy, Insights from Animal Models. Neuroscience 2020; 445:69-82. [DOI: 10.1016/j.neuroscience.2020.02.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/22/2020] [Accepted: 02/21/2020] [Indexed: 02/09/2023]
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