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Bertocchi I, Cifarelli L, Oberto A, Eva CE, Sprengel R, Mirza NR, Muglia P. Radiprodil, a selective GluN2B negative allosteric modulator, rescues audiogenic seizures in mice carrying the GluN2A(N615S) mutation. Br J Pharmacol 2024; 181:1886-1894. [PMID: 38529699 DOI: 10.1111/bph.16361] [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: 08/04/2023] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND AND PURPOSE GRIN-related disorders are neurodevelopmental disorders caused by mutations in N-methyl-D-aspartate receptor (NMDAR) subunit genes. A large fraction of these mutations lead to a 'gain of function' (GoF) of the NMDAR. Patients present with a range of symptoms including epilepsy, intellectual disability, behavioural and motor. Controlling seizures is a significant unmet medical need in most patients with GRIN-related disorders. Although several hundred GRIN mutations have been identified in humans, until recently none of the mouse models carrying Grin mutations/deletions showed an epileptic phenotype. The two recent exceptions both carry mutations of GluN2A. The aim of this study was to assess the efficacy of radiprodil, a selective negative allosteric modulator of GluN2B-containing NMDARs, in counteracting audiogenic seizures (AGS) in a murine model carrying the GluN2A(N615S) homozygous mutation (Grin2aS/S mice). EXPERIMENTAL APPROACH Grin2aS/S mice were acutely treated with radiprodil at different doses before the presentation of a high-frequency acoustic stimulus commonly used for AGS induction. KEY RESULTS Radiprodil significantly and dose-dependently reduced the onset and severity of AGS in Grin2aS/S mice. Surprisingly, the results revealed a sex-dependent difference in AGS susceptibility and in the dose-dependent protection of radiprodil in the two genders. Specifically, radiprodil was more effective in female versus male mice. CONCLUSION AND IMPLICATIONS Overall, our data clearly show that radiprodil, a GluN2B selective negative allosteric modulator, may have the potential to control seizures in patients with GRIN2A GoF mutations. Further studies are warranted to better understand the sex-dependent effects observed in this study.
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Affiliation(s)
- Ilaria Bertocchi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Orbassano (Turin), Italy
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
- Neuroscience Institute of Turin, Orbassano (Turin), Italy
| | - Lorenzo Cifarelli
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Orbassano (Turin), Italy
| | - Alessandra Oberto
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Orbassano (Turin), Italy
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
- Neuroscience Institute of Turin, Orbassano (Turin), Italy
| | - Carola Eugenia Eva
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Orbassano (Turin), Italy
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
- Neuroscience Institute of Turin, Orbassano (Turin), Italy
| | - Rolf Sprengel
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Naheed Rohman Mirza
- GRIN Therapeutics Inc, New York, NY, USA
- Sygnature Discovery, BioCity, Nottingham, UK
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Montanucci L, Brünger T, Bhattarai N, Boßelmann CM, Kim S, Allen JP, Zhang J, Klöckner C, Fariselli P, May P, Lemke JR, Myers SJ, Yuan H, Traynelis SF, Lal D. Distances from ligands as main predictive features for pathogenicity and functional effect of variants in NMDA receptors. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.06.24306939. [PMID: 38766179 PMCID: PMC11100844 DOI: 10.1101/2024.05.06.24306939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Genetic variants in genes GRIN1 , GRIN2A , GRIN2B , and GRIN2D , which encode subunits of the N-methyl-D-aspartate receptor (NMDAR), have been associated with severe and heterogeneous neurologic diseases. Missense variants in these genes can result in gain or loss of the NMDAR function, requiring opposite therapeutic treatments. Computational methods that predict pathogenicity and molecular functional effects are therefore crucial for accurate diagnosis and therapeutic applications. We assembled missense variants: 201 from patients, 631 from general population, and 159 characterized by electrophysiological readouts showing whether they can enhance or reduce the receptor function. This includes new functional data from 47 variants reported here, for the first time. We found that pathogenic/benign variants and variants that increase/decrease the channel function were distributed unevenly on the protein structure, with spatial proximity to ligands bound to the agonist and antagonist binding sites being key predictive features. Leveraging distances from ligands, we developed two independent machine learning-based predictors for NMDAR missense variants: a pathogenicity predictor which outperforms currently available predictors (AUC=0.945, MCC=0.726), and the first binary predictor of molecular function (increase or decrease) (AUC=0.809, MCC=0.523). Using these, we reclassified variants of uncertain significance in the ClinVar database and refined a previous genome-informed epidemiological model to estimate the birth incidence of molecular mechanism-defined GRIN disorders. Our findings demonstrate that distance from ligands is an important feature in NMDARs that can enhance variant pathogenicity prediction and enable functional prediction. Further studies with larger numbers of phenotypically and functionally characterized variants will enhance the potential clinical utility of this method.
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Juliá-Palacios N, Olivella M, Sigatullina Bondarenko M, Ibáñez-Micó S, Muñoz-Cabello B, Alonso-Luengo O, Soto-Insuga V, García-Navas D, Cuesta-Herraiz L, Andreo-Lillo P, Aguilera-Albesa S, Hedrera-Fernández A, González Alguacil E, Sánchez-Carpintero R, Martín Del Valle F, Jiménez González E, Cean Cabrera L, Medina-Rivera I, Perez-Ordoñez M, Colomé R, Lopez L, Engracia Cazorla M, Fornaguera M, Ormazabal A, Alonso-Colmenero I, Illescas KS, Balsells-Mejía S, Mari-Vico R, Duffo Viñas M, Cappuccio G, Terrone G, Romano R, Manti F, Mastrangelo M, Alfonsi C, de Siqueira Barros B, Nizon M, Gjerulfsen CE, Muro VL, Karall D, Zeiner F, Masnada S, Peterlongo I, Oyarzábal A, Santos-Gómez A, Altafaj X, García-Cazorla Á. L-serine treatment in patients with GRIN-related encephalopathy: a phase 2A, non-randomized study. Brain 2024; 147:1653-1666. [PMID: 38380699 DOI: 10.1093/brain/awae041] [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: 08/03/2023] [Revised: 12/20/2023] [Accepted: 01/21/2024] [Indexed: 02/22/2024] Open
Abstract
GRIN-related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2-18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B, GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes.
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Affiliation(s)
- Natalia Juliá-Palacios
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Mireia Olivella
- Bioinformatics and Bioimaging Group. Faculty of Science, Technology and Engineering, University of Vic-Central University of Catalonia, 08500 Vic, Spain
- Institute for Research and Innovation in Life and Health Sciences (IRIS-CC), University of Vic-Central University of Catalonia, 08500 Vic, Spain
| | - Mariya Sigatullina Bondarenko
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | | | - Beatriz Muñoz-Cabello
- Department of Pediatrics, Hospital Universitario Virgen del Rocío, 41013 Sevilla, Spain
| | - Olga Alonso-Luengo
- Department of Pediatrics, Hospital Universitario Virgen del Rocío, 41013 Sevilla, Spain
| | | | - Deyanira García-Navas
- Department of Pediatric Neurology, Complejo Hospitalario Universitario de Cáceres, 10003 Cáceres, Spain
| | | | - Patricia Andreo-Lillo
- Neuropediatric Unit, Pediatric Department, University Hospital of Sant Joan d'Alacant, 03550 Sant Joan d'Alacant, Spain
| | - Sergio Aguilera-Albesa
- Paediatric Neurology Unit, Department of Pediatrics, Hospital Universitario de Navarra, 31008, Pamplona, Spain
| | - Antonio Hedrera-Fernández
- Child Neurology Unit, Pediatrics Department, Hospital Universitario Central de Asturias, 33011 Oviedo, Spain
| | | | | | | | | | | | - Ines Medina-Rivera
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Marta Perez-Ordoñez
- Child and Adolescent Mental Health Area, Psychiatry and Psychology, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Roser Colomé
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Laura Lopez
- Department of Rehabilitation, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - María Engracia Cazorla
- Department of Rehabilitation, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Montserrat Fornaguera
- Department of Rehabilitation, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Aida Ormazabal
- Department of Clinical Biochemistry, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- European Reference Network for Hereditary Metabolic Diseases (MetabERN), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Itziar Alonso-Colmenero
- Pediatric Neurology Department, Hospital Sant Joan de Déu, Full Member of ERN EpiCare, Barcelona University, 08950 Barcelona, Spain
| | - Katia Sofía Illescas
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Sol Balsells-Mejía
- Department of Research Promotion and Management. Statistical Support, Hospital Sant Joan de Déu (HSJD), 08950 Barcelona, Spain
| | - Rosanna Mari-Vico
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Maria Duffo Viñas
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
- Child and Adolescent Mental Health Area, Psychiatry and Psychology, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Gerarda Cappuccio
- Department of Translational Medical Sciences, Università degli Studi di Napoli 'Federico II', 80125 Naples, Italy
- Telethon Institute of Genetics and Medicine, Department of Pediatrics, Pozzuoli, 80131 Naples, Italy
| | - Gaetano Terrone
- Department of Translational Medical Sciences, Università degli Studi di Napoli 'Federico II', 80125 Naples, Italy
| | - Roberta Romano
- Department of Translational Medical Sciences, Università degli Studi di Napoli 'Federico II', 80125 Naples, Italy
| | - Filippo Manti
- Department of Human Neuroscience, University of Rome La Sapienza, 00185 Roma, Lazio, Italy
| | - Mario Mastrangelo
- Department of Women and Child Health and Uroginecological Sciences, Sapienza University of Rome, 00185 Rome, Italy
- Child Neurology and Psychiatry Unit, Department of Neuroscience/Mental Health, Azienda Ospedaliero-Universitaria Policlinico Umberto I, 00161 Rome, Italy
| | - Chiara Alfonsi
- Department of Human Neuroscience, University of Rome La Sapienza, 00185 Roma, Lazio, Italy
| | - Bruna de Siqueira Barros
- Núcleo de Estudos da Saúde do Adolescente, Programa de Pós-Graduação em Ciências Médicas, Universidade do Estado do Rio de Janeiro, Faculdade de Ciência Médicas, 56066 Rio de Janeiro, RJ, Brazil
| | - Mathilde Nizon
- Service de Génétique Médicale, CHU Nantes, 44093 Nantes, France
| | | | - Valeria L Muro
- Pediatric Neurology Unit, Hospital Britanico Buenos Aires, C1280AEB Buenos Aires, Argentina
| | - Daniela Karall
- Clinic for Paediatrics, Division of Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Fiona Zeiner
- Clinic for Paediatrics, Division of Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Silvia Masnada
- Department of Child Neurology, V. Buzzi Children's Hospital, 20125 Milan, Italy
| | - Irene Peterlongo
- Department of Child Neurology, V. Buzzi Children's Hospital, 20125 Milan, Italy
| | - Alfonso Oyarzábal
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
| | - Ana Santos-Gómez
- Department of Biomedicine, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain
| | - Xavier Altafaj
- Department of Biomedicine, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain
| | - Ángeles García-Cazorla
- Neurometabolic Unit and Synaptic Metabolism Lab, Department of Neurology, Hospital Sant Joan de Déu-IRSJD, CIBERER and MetabERN, 08950 Barcelona, Spain
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Lin G, Xu Q, Li J, Chu Z, Ma X, Zhu Q, Zhao Y, Mo J, Ye W, Shao L, Fang T, He M, Yue S, Dai M. Design, Synthesis, and Biological Evaluation of Pierardine Derivatives as Novel Brain-Penetrant and In Vivo Potent NMDAR-GluN2B Antagonists for Ischemic Stroke Treatment. J Med Chem 2024; 67:3358-3384. [PMID: 38413367 DOI: 10.1021/acs.jmedchem.3c01524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
A series of structurally novel GluN2B NMDAR antagonists were designed, synthesized, and biologically evaluated as anti-stroke therapeutics by optimizing the chemical structure of Pierardine, the active ingredient of traditional Chinese medicine Dendrobium aphyllum (Roxb.) C. E. Fischer identified via in silico screening. The systematic structure-activity relationship study led to the discovery of 58 with promising NMDAR-GluN2B binding affinity and antagonistic activity. Of the two enantiomers, S-58 exhibited significant inhibition (IC50 = 74.01 ± 12.03 nM) against a GluN1/GluN2B receptor-mediated current in a patch clamp assay. In addition, it displayed favorable specificity over other subtypes and off-target receptors. In vivo, S-58 exerted therapeutic efficacy comparable to that of the approved GluN2B NMDAR antagonist ifenprodil and excellent safety profiles. In addition to the attractive in vitro and in vivo potency, S-58 exhibited excellent brain exposure. In light of these merits, S-58 has been advanced to further preclinical investigation as a potential anti-stroke candidate.
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Affiliation(s)
- Gaofeng Lin
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei 230012, China
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Qinlong Xu
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Jiaming Li
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei 230012, China
- Department of Medicinal Chemistry, Anhui Academy of Chinese Medicine, Hefei 230012, China
- Anhui Province Key Laboratory of Research & Development of Chinese Medicine, Hefei 230012, China
| | - Zhaoxing Chu
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Xiaodong Ma
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei 230012, China
- Department of Medicinal Chemistry, Anhui Academy of Chinese Medicine, Hefei 230012, China
- Anhui Province Key Laboratory of Research & Development of Chinese Medicine, Hefei 230012, China
| | - Qihua Zhu
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Yan Zhao
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Jiajia Mo
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Wenfeng Ye
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Li Shao
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Tao Fang
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Minghan He
- Rutgers Preparatory School, Somerset, New Jersey 08873, United States
| | - Shaoyun Yue
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
| | - Mingqi Dai
- Hefei Institute of Pharmaceutical Industry Company, Ltd., Hefei 230088, China
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Firaha D, Liu YM, van de Streek J, Sasikumar K, Dietrich H, Helfferich J, Aerts L, Braun DE, Broo A, DiPasquale AG, Lee AY, Le Meur S, Nilsson Lill SO, Lunsmann WJ, Mattei A, Muglia P, Putra OD, Raoui M, Reutzel-Edens SM, Rome S, Sheikh AY, Tkatchenko A, Woollam GR, Neumann MA. Predicting crystal form stability under real-world conditions. Nature 2023; 623:324-328. [PMID: 37938708 PMCID: PMC10632141 DOI: 10.1038/s41586-023-06587-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 08/30/2023] [Indexed: 11/09/2023]
Abstract
The physicochemical properties of molecular crystals, such as solubility, stability, compactability, melting behaviour and bioavailability, depend on their crystal form1. In silico crystal form selection has recently come much closer to realization because of the development of accurate and affordable free-energy calculations2-4. Here we redefine the state of the art, primarily by improving the accuracy of free-energy calculations, constructing a reliable experimental benchmark for solid-solid free-energy differences, quantifying statistical errors for the computed free energies and placing both hydrate crystal structures of different stoichiometries and anhydrate crystal structures on the same energy landscape, with defined error bars, as a function of temperature and relative humidity. The calculated free energies have standard errors of 1-2 kJ mol-1 for industrially relevant compounds, and the method to place crystal structures with different hydrate stoichiometries on the same energy landscape can be extended to other multi-component systems, including solvates. These contributions reduce the gap between the needs of the experimentalist and the capabilities of modern computational tools, transforming crystal structure prediction into a more reliable and actionable procedure that can be used in combination with experimental evidence to direct crystal form selection and establish control5.
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Affiliation(s)
| | | | | | | | | | - Julian Helfferich
- Avant-garde Materials Simulation, Merzhausen, Germany
- JobRad, Freiburg, Germany
| | - Luc Aerts
- UCB Pharma SA, Chemin du Foriest, Braine-l'Alleud, Belgium
| | - Doris E Braun
- Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Anders Broo
- Data Science and Modelling, Pharmaceutical Sciences, R&D, AstraZeneca Gothenburg, Mölndal, Sweden
| | | | - Alfred Y Lee
- Merck, Analytical Research & Development, Rahway, NJ, USA
| | - Sarah Le Meur
- UCB Pharma SA, Chemin du Foriest, Braine-l'Alleud, Belgium
| | - Sten O Nilsson Lill
- Data Science and Modelling, Pharmaceutical Sciences, R&D, AstraZeneca Gothenburg, Mölndal, Sweden
| | | | - Alessandra Mattei
- Solid State Chemistry, Research & Development, AbbVie, North Chicago, IL, USA
| | | | - Okky Dwichandra Putra
- Early Product Development and Manufacturing, Pharmaceutical Sciences R&D, AstraZeneca Gothenburg, Mölndal, Sweden
| | | | - Susan M Reutzel-Edens
- Cambridge Crystallographic Data Centre, Cambridge, UK
- SuRE Pharma Consulting, Zionsville, IN, USA
| | - Sandrine Rome
- UCB Pharma SA, Chemin du Foriest, Braine-l'Alleud, Belgium
| | - Ahmad Y Sheikh
- Solid State Chemistry, Research & Development, AbbVie, North Chicago, IL, USA
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg, Luxembourg City, Luxembourg
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Sills GJ. Pharmacological diversity amongst approved and emerging antiseizure medications for the treatment of developmental and epileptic encephalopathies. Ther Adv Neurol Disord 2023; 16:17562864231191000. [PMID: 37655228 PMCID: PMC10467199 DOI: 10.1177/17562864231191000] [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: 02/20/2023] [Accepted: 07/13/2023] [Indexed: 09/02/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are rare neurodevelopmental disorders characterised by early-onset and often intractable seizures and developmental delay/regression, and include Dravet syndrome and Lennox-Gastaut syndrome (LGS). Rufinamide, fenfluramine, stiripentol, cannabidiol and ganaxolone are antiseizure medications (ASMs) with diverse mechanisms of action that have been approved for treating specific DEEs. Rufinamide is thought to suppress neuronal hyperexcitability by preventing the functional recycling of voltage-gated sodium channels from the inactivated to resting state. It is licensed for adjunctive treatment of seizures associated with LGS. Fenfluramine increases extracellular serotonin levels and may reduce seizures via activation of specific serotonin receptors and positive modulation of the sigma-1 receptor. Fenfluramine is licensed for adjunctive treatment of seizures associated with Dravet syndrome and LGS. Stiripentol is a positive allosteric modulator of type-A gamma-aminobutyric acid (GABAA) receptors. As a broad-spectrum inhibitor of cytochrome P450 enzymes, its antiseizure effects may additionally arise through pharmacokinetic interactions with co-administered ASMs. Stiripentol is licensed for treating seizures associated with Dravet syndrome in patients taking clobazam and/or valproate. The mechanism(s) of action of cannabidiol remains largely unclear although multiple targets have been proposed, including transient receptor potential vanilloid 1, G protein-coupled receptor 55 and equilibrative nucleoside transporter 1. Cannabidiol is licensed as adjunctive treatment in conjunction with clobazam for seizures associated with Dravet syndrome and LGS, and as adjunctive treatment of seizures associated with tuberous sclerosis complex. Like stiripentol, ganaxolone is a positive allosteric modulator at GABAA receptors. It has recently been licensed in the USA for the treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder. Greater understanding of the causes of DEEs has driven research into the potential use of other novel and repurposed agents. Putative ASMs currently in clinical development for use in DEEs include soticlestat, carisbamate, verapamil, radiprodil, clemizole and lorcaserin.
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Affiliation(s)
- Graeme J. Sills
- School of Life Sciences, University of Glasgow, Room 341, Sir James Black Building, Glasgow G12 8QQ, UK
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7
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Wang X, Mei D, Gou L, Zhao S, Gao C, Guo J, Luo S, Guo B, Yang Z, Wang Q, Tan T, Zhang Y. Functional Evaluation of a Novel GRIN2B Missense Variant Associated with Epilepsy and Intellectual Disability. Neuroscience 2023; 526:107-120. [PMID: 37385334 DOI: 10.1016/j.neuroscience.2023.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/17/2023] [Accepted: 06/21/2023] [Indexed: 07/01/2023]
Abstract
Epilepsy, a neurological condition, is widely prevalent among individuals with intellectual disability (ID). It is well established that N-methyl-D-aspartate (NMDA) receptors play an important role in both epilepsy and ID. Autosomal dominant mutations in the GRIN2B gene, which encodes the GluN2B subunit of the NMDA receptor, have been reported to be associated with epilepsy and ID. However, the underlying mechanism of this association is not well-understood. In this study, we identified a novel GRIN2B mutation (c.3272A > C, p.K1091T) in a patient with epilepsy and ID. The proband was a one year and ten months old girl. GRIN2B variant was inherited from her mother. We further investigated the functional consequences of this mutation. Our findings revealed that the p.K1091T mutation created a Casein kinase 2 phosphorylation site. Using recombinant NMDA receptors containing the GluN2B-K1091T along with GluN1 in HEK 293T cells, we observed significant defects in its interactions with postsynaptic density 95. It is accompanied by reduced delivery of the receptors to the cell membrane and a decrease in glutamate affinity. Moreover, primary neurons expressing GluN2B-K1091T also exhibited impaired surface expression of NMDA receptors, a reduction in dendritic spine number and excitatory synaptic transmission. In summary, our study reports a novel GRIN2B mutation and provides functional characteristics of this mutation in vitro, thereby contributing to the understanding of GRIN2B variants in epilepsy and ID.
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Affiliation(s)
- Xiaona Wang
- Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Henan Engineering Research Center of Childhood Neurodevelopment, Zhengzhou 450018, Henan, China.
| | - Daoqi Mei
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou 450018, Henan, China
| | - Lingshan Gou
- Center for Genetic Medicine, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou 221000, Jiangsu, China
| | - Shuai Zhao
- Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Henan Engineering Research Center of Childhood Neurodevelopment, Zhengzhou 450018, Henan, China
| | - Chao Gao
- Department of Rehabilitation, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou 450018, Henan, China
| | - Jisheng Guo
- School of Basic Medical Sciences, Yantai Campus of Binzhou Medical University, Yantai 264003, Shandong, China
| | - Shuying Luo
- Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Henan Engineering Research Center of Childhood Neurodevelopment, Zhengzhou 450018, Henan, China
| | - Bin Guo
- School of Traditional Chinese Medicine, Ningxia Medical University, Ningxia 750004, China
| | - Zhigang Yang
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou 450018, Henan, China
| | - Qi Wang
- Department of Histology and Embryology, School of Basic Medicine, Guizhou Medical University, Guiyang 550025, Guizhou, China.
| | - Tao Tan
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Wenzhou Medical University, Wenzhou 325000, Zhejiang, China.
| | - Yaodong Zhang
- Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Henan Engineering Research Center of Childhood Neurodevelopment, Zhengzhou 450018, Henan, China.
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8
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Wirrell EC, Riney K, Specchio N, Zuberi SM. How have the recent updated epilepsy classifications impacted on diagnosis and treatment? Expert Rev Neurother 2023; 23:969-980. [PMID: 37676056 DOI: 10.1080/14737175.2023.2254937] [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: 07/19/2023] [Accepted: 08/30/2023] [Indexed: 09/08/2023]
Abstract
INTRODUCTION Epilepsies are a diverse group of disorders which differ regarding prognosis for seizure control and associated comorbidities. Accurate classification is critical to choose the highest yield investigations and best therapeutic options and to provide the most accurate prognoses regarding the expected degree of seizure control, possible remission, and risk of associated comorbidities to patients and their families. This article reviews the recent updates in epilepsy classification to illustrate how accurate classification impacts care for persons with epilepsy. AREAS COVERED The authors discuss the ILAE 2017 Classification of the Epilepsies along with the modification of the classification for neonatal seizures and epilepsies. They also discuss the ILAE position papers on Epilepsy syndromes in neonates and infants and children of variable age and the Idiopathic Generalized Epilepsies. EXPERT OPINION Accurate epilepsy classification allows selection of the highest yield investigations, choice of optimal therapies, and accurate prognostication of seizures (likelihood of response to antiseizure treatments and likelihood of remission with age), as well as comorbidities (likelihood, type, and severity). As we move into the era of disease modifying therapy, early accurate identification of underlying causes with timely introduction of specific treatments will be crucial to lessen the severity of epilepsy, with improved seizure control and attenuation of associated comorbidities.
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Affiliation(s)
- Elaine C Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Kate Riney
- Neurosciences Unit, Queensland Children's Hospital, Australia and Faculty of Medicine, University of St Lucia, Brisbane, Queensland, Australia
| | - Nicola Specchio
- Clinical and Experimental Neurology, Bambino Gesu Children's Hospital, IRCCS, Full Member of European Reference Network on Rare and Complex Epilepsies (EpiCARE), Rome, Italy
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Royal Hospital for Children, Glasgow, UK
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9
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Brock S, Laquerriere A, Marguet F, Myers SJ, Hongjie Y, Baralle D, Vanderhasselt T, Stouffs K, Keymolen K, Kim S, Allen J, Shaulsky G, Chelly J, Marcorelle P, Aziza J, Villard L, Sacaze E, de Wit MCY, Wilke M, Mancini GMS, Hehr U, Lim D, Mansour S, Traynelis SF, Beneteau C, Denis-Musquer M, Jansen AC, Fry AE, Bahi-Buisson N. Overlapping cortical malformations in patients with pathogenic variants in GRIN1 and GRIN2B. J Med Genet 2023; 60:183-192. [PMID: 35393335 PMCID: PMC10642159 DOI: 10.1136/jmedgenet-2021-107971] [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: 05/13/2021] [Accepted: 03/16/2022] [Indexed: 01/29/2023]
Abstract
BACKGROUND Malformations of cortical development (MCDs) have been reported in a subset of patients with pathogenic heterozygous variants in GRIN1 or GRIN2B, genes which encode for subunits of the N-methyl-D-aspartate receptor (NMDAR). The aim of this study was to further define the phenotypic spectrum of NMDAR-related MCDs. METHODS We report the clinical, radiological and molecular features of 7 new patients and review data on 18 previously reported individuals with NMDAR-related MCDs. Neuropathological findings for two individuals with heterozygous variants in GRIN1 are presented. We report the clinical and neuropathological features of one additional individual with homozygous pathogenic variants in GRIN1. RESULTS Heterozygous variants in GRIN1 and GRIN2B were associated with overlapping severe clinical and imaging features, including global developmental delay, epilepsy, diffuse dysgyria, dysmorphic basal ganglia and hippocampi. Neuropathological examination in two fetuses with heterozygous GRIN1 variants suggests that proliferation as well as radial and tangential neuronal migration are impaired. In addition, we show that neuronal migration is also impaired by homozygous GRIN1 variants in an individual with microcephaly with simplified gyral pattern. CONCLUSION These findings expand our understanding of the clinical and imaging features of the 'NMDARopathy' spectrum and contribute to our understanding of the likely underlying pathogenic mechanisms leading to MCD in these patients.
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Affiliation(s)
- Stefanie Brock
- Department of Pathology, Universitair Ziekenhuis Brussel, Brussels, Belgium
- Neurogenetics Research Group, Reproduction Genetics and Regenerative Medicine Research Cluster, Vrije Universiteit Brussel, Brussels, Belgium
| | - Annie Laquerriere
- Normandy Centre for Genomic and Personalized Medicine, INSERM U1245, Rouen, France
- Department of Pathology, Rouen University Hospital, Rouen, France
| | - Florent Marguet
- Normandy Centre for Genomic and Personalized Medicine, INSERM U1245, Rouen, France
- Department of Pathology, Rouen University Hospital, Rouen, France
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - Yuan Hongjie
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - Diana Baralle
- Human Development and Health, University of Southampton, Southampton, UK
| | - Tim Vanderhasselt
- Department of Radiology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Katrien Stouffs
- Neurogenetics Research Group, Reproduction Genetics and Regenerative Medicine Research Cluster, Vrije Universiteit Brussel, Brussels, Belgium
- Center for Reproduction and Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Kathelijn Keymolen
- Center for Reproduction and Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - James Allen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - Gil Shaulsky
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - Jamel Chelly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, INSERM U1258, Université de Strasbourg, Strasbourg, France
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaire de Strasbourg, Strasbourg, France
| | - Pascale Marcorelle
- Service d'Anatomie Pathologique, Centre Hospitalier Universitaire de Brest; Laboratoire Neurosciences de Brest, Université de Brest, Brest, France
| | - Jacqueline Aziza
- Department of Pathology, University Institute for Cancer, Toulouse, France
| | - Laurent Villard
- Inserm, Marseille Medical Genetics Center, Aix-Marseille University, Marseille, France
- Department of Medical Genetics, La Timone Children's Hospital, Marseille, France
| | - Elise Sacaze
- Department of Pediatrics, Centre Hospitalier Universitaire de Brest, Brest, France
| | - Marie C Y de Wit
- Department of Pediatric Neurology, ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Martina Wilke
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Ute Hehr
- Center for Human Genetics, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Derek Lim
- West Midlands Regional Genetics Service and Birmingham Health Partners, Birmingham Women's and Children's Hospitals NHS Foundation Trust, University of Southampton, Southampton, UK
| | - Sahar Mansour
- SW Thames Regional Genetics Service, University of London St George's Molecular and Clinical Sciences Research Institute, London, UK
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine Atlanta, Atlanta, Georgia, USA
| | - Claire Beneteau
- Département de Génétique, Hôpital Universitaire de Nantes, Nantes, France
- UF de Fœtopathologie et Génétique, CHU Nantes, Nantes, France
| | - Marie Denis-Musquer
- UF de Fœtopathologie et Génétique, CHU Nantes, Nantes, France
- Department of Pathology, CHU Nantes, Nantes, France
| | - Anna C Jansen
- Pediatric Neurology Unit, Universitair Ziekenhuis Antwerpen, Antwerp, Belgium
| | - Andrew E Fry
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
| | - Nadia Bahi-Buisson
- Pediatric Neurology, Necker Enfants Malades Hospital, Université de Paris, Paris, France
- Embryology and Genetics of Congenital Malformations, Institut Imagine (INSERM UMR-1163), Paris, France
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10
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Santos-Gómez A, García-Recio A, Miguez-Cabello F, Soto D, Altafaj X, Olivella M. Identification of homologous GluN subunits variants accelerates GRIN variants stratification. Front Cell Neurosci 2022; 16:998719. [PMID: 36619673 PMCID: PMC9816381 DOI: 10.3389/fncel.2022.998719] [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: 07/20/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
The clinical spectrum of GRIN-related neurodevelopmental disorders (GRD) results from gene- and variant-dependent primary alterations of the NMDA receptor, disturbing glutamatergic neurotransmission. Despite GRIN gene variants' functional annotations being dually critical for stratification and precision medicine design, genetically diagnosed pathogenic GRIN variants currently outnumber their relative functional annotations. Based on high-resolution crystal 3D models and topological domains conservation between GluN1, GluN2A, and GluN2B subunits of the NMDAR, we have generated GluN1-GluN2A-GluN2B subunits structural superimposition model to find equivalent positions between GluN subunits. We have developed a GRIN structural algorithm that predicts functional changes in the equivalent structural positions in other GluN subunits. GRIN structural algorithm was computationally evaluated to the full GRIN missense variants repertoire, consisting of 4,525 variants. The analysis of this structure-based model revealed an absolute predictive power for GluN1, GluN2A, and GluN2B subunits, both in terms of pathogenicity-association (benign vs. pathogenic variants) and functional impact (loss-of-function, benign, gain-of-function). Further, we validated this computational algorithm experimentally, using an in silico library of GluN2B-equivalent GluN2A artificial variants, designed from pathogenic GluN2B variants. Thus, the implementation of the GRIN structural algorithm allows to computationally predict the pathogenicity and functional annotations of GRIN variants, resulting in the duplication of pathogenic GRIN variants assignment, reduction by 30% of GRIN variants with uncertain significance, and increase by 70% of functionally annotated GRIN variants. Finally, GRIN structural algorithm has been implemented into GRIN variants Database (http://lmc.uab.es/grindb), providing a computational tool that accelerates GRIN missense variants stratification, contributing to clinical therapeutic decisions for this neurodevelopmental disorder.
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Affiliation(s)
- Ana Santos-Gómez
- Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Spain,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Adrián García-Recio
- Bioinfomatics and Medical Statistics Group, University of Vic—Central University of Catalonia, Barcelona, Spain
| | - Federico Miguez-Cabello
- Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Spain,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - David Soto
- Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Spain,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Xavier Altafaj
- Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Spain,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain,*Correspondence: Xavier Altafaj Mireia Olivella
| | - Mireia Olivella
- Bioinfomatics and Medical Statistics Group, University of Vic—Central University of Catalonia, Barcelona, Spain,*Correspondence: Xavier Altafaj Mireia Olivella
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11
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Benske TM, Mu TW, Wang YJ. Protein quality control of N-methyl-D-aspartate receptors. Front Cell Neurosci 2022; 16:907560. [PMID: 35936491 PMCID: PMC9352929 DOI: 10.3389/fncel.2022.907560] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/29/2022] [Indexed: 12/23/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are glutamate-gated cation channels that mediate excitatory neurotransmission and are critical for synaptic development and plasticity in the mammalian central nervous system (CNS). Functional NMDARs typically form via the heterotetrameric assembly of GluN1 and GluN2 subunits. Variants within GRIN genes are implicated in various neurodevelopmental and neuropsychiatric disorders. Due to the significance of NMDAR subunit composition for regional and developmental signaling at synapses, properly folded receptors must reach the plasma membrane for their function. This review focuses on the protein quality control of NMDARs. Specifically, we review the quality control mechanisms that ensure receptors are correctly folded and assembled within the endoplasmic reticulum (ER) and trafficked to the plasma membrane. Further, we discuss disease-associated variants that have shown disrupted NMDAR surface expression and function. Finally, we discuss potential targeted pharmacological and therapeutic approaches to ameliorate disease phenotypes by enhancing the expression and surface trafficking of subunits harboring disease-associated variants, thereby increasing their incorporation into functional receptors.
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Affiliation(s)
| | - Ting-Wei Mu
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Ya-Juan Wang
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
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12
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Specchio N, Pietrafusa N, Perucca E, Cross JH. New paradigms for the treatment of pediatric monogenic epilepsies: Progressing toward precision medicine. Epilepsy Behav 2022; 131:107961. [PMID: 33867301 DOI: 10.1016/j.yebeh.2021.107961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/25/2022]
Abstract
Despite the availability of 28 antiseizure medications (ASMs), one-third of people with epilepsy fail to achieve sustained freedom from seizures. Clinical outcome is even poorer for children with developmental and epileptic encephalopathies (DEEs), many of which are due to single-gene mutations. Discovery of causative genes, however, has paved the way to understanding the molecular mechanism underlying these epilepsies, and to the rational application, or development, of precision treatments aimed at correcting the specific functional defects or their consequences. This article provides an overview of current progress toward precision medicine (PM) in the management of monogenic pediatric epilepsies, by focusing on four different scenarios, namely (a) rational selection of ASMs targeting specifically the underlying pathogenetic mechanisms; (b) development of targeted therapies based on novel molecules; (c) use of dietary treatments or food constituents aimed at correcting specific metabolic defects; and (d) repurposing of medications originally approved for other indications. This article is part of the Special Issue "Severe Infantile Epilepsies".
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Affiliation(s)
- Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Full Member of European Reference Network EpiCARE, Rome, Italy.
| | - Nicola Pietrafusa
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Full Member of European Reference Network EpiCARE, Rome, Italy
| | - Emilio Perucca
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
| | - J Helen Cross
- UCL NIHR BRC Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
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13
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Perry LD, Hogg SL, Bowdin S, Ambegaonkar G, Parker AP. Fifteen-minute consultation: The efficient investigation of infantile and childhood epileptic encephalopathies in the era of modern genomics. Arch Dis Child Educ Pract Ed 2022; 107:80-87. [PMID: 33414255 DOI: 10.1136/archdischild-2020-320606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/05/2020] [Accepted: 12/09/2020] [Indexed: 11/03/2022]
Abstract
The investigation of children presenting with infantile and childhood epileptic encephalopathies (ICEE) is challenging due to diverse aetiologies, overlapping phenotypes and the relatively low diagnostic yield of MRI, electroencephalography (EEG) and biochemical investigations. Careful history and thorough examination remain essential as these may identify an acquired cause or indicate more targeted investigation for a genetic disorder. Whole exome sequencing (WES) with analysis of a panel of candidate epilepsy genes has increased the diagnostic yield. Whole genome sequencing (WGS), particularly as a trio with both parents' DNA, is likely to supersede WES. Modern genomic investigation impacts on the timing and necessity of other testing. We propose a structured approach for children presenting with ICEE where there is diagnostic uncertainty, emphasising the importance of WGS or, if unavailable, WES early in the investigative process. We note the importance of expert review of all investigations, including radiology, neurophysiology and biochemistry, to confirm the technique used was appropriate as well as the results. It is essential to counsel families on the risks associated with the procedures, the yield of the procedures, findings that are difficult to interpret and implication of 'negative' results. Where children remain without a diagnosis despite comprehensive investigation, we note the importance of ongoing multidisciplinary care.
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Affiliation(s)
- Luke Daniel Perry
- Developmental Neurosciences, University College London, Great Ormond Street Institute of Child Health, London, UK
| | - Sarah Louise Hogg
- Biochemical Genetics Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Sarah Bowdin
- Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Gautam Ambegaonkar
- Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Alasdair Pj Parker
- Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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14
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Han W, Yuan H, Allen JP, Kim S, Shaulsky GH, Perszyk RE, Traynelis SF, Myers SJ. Opportunities for Precision Treatment of GRIN2A and GRIN2B Gain-of-Function Variants in Triheteromeric N-Methyl-D-Aspartate Receptors. J Pharmacol Exp Ther 2022; 381:54-66. [PMID: 35110392 PMCID: PMC11046977 DOI: 10.1124/jpet.121.001000] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/07/2022] [Indexed: 11/22/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are tetrameric assemblies of two glutamate N-methyl-D-aspartate receptor subunits, GluN1 and two GluN2, that mediate excitatory synaptic transmission in the central nervous system. Four genes (GRIN2A-D) encode four distinct GluN2 subunits (GluN2A-D). Thus, NMDARs can be diheteromeric assemblies of two GluN1 plus two identical GluN2 subunits, or triheteromeric assemblies of two GluN1 subunits plus two different GluN2 subunits. An increasing number of de novo GRIN variants have been identified in patients with neurologic conditions and with GRIN2A and GRIN2B harboring the vast majority (> 80%) of variants in these cases. These variants produce a wide range of effects on NMDAR function depending upon its subunit subdomain location and additionally on the subunit composition of diheteromeric versus triheteromeric NMDARs. Increasing evidence implicates triheteromeric GluN1/GluN2A/GluN2B receptors as a major component of the NMDAR pool in the adult cortex and hippocampus. Here, we explore the ability of GluN2A- and GluN2B-selective inhibitors to reduce excess current flow through triheteromeric GluN1/GluN2A/GluN2B receptors that contain one copy of GRIN2A or GRIN2B gain-of-function variants. Our data reveal a broad range of sensitivities for variant-containing triheteromeric receptors to subunit-selective inhibitors, with some variants still showing strong sensitivity to inhibitors, whereas others are relatively insensitive. Most variants, however, retain sensitivity to non-selective channel blockers and the competitive antagonist D-(-)-2-amino-5-phosphonopentanoic acid. These results suggest that with comprehensive analysis, certain disease-related GRIN2A and GRIN2B variants can be identified as potential targets for subunit-selective modulation and potential therapeutic gain. SIGNIFICANCE STATEMENT: Triheteromeric NMDA receptors that contain one copy each of the GluN2A and GluN2B subunits show intermediate sensitivity to GluN2A- and GluN2B-selective inhibitors, making these compounds candidates for attenuating overactive, GRIN variant-containing NMDA receptors associated with neurological conditions. We show that functional evaluation of variant properties with inhibitor pharmacology can support selection of a subset of variants for which GluN2 subunit-selective agents remain effective inhibitors of variant-containing triheteromeric NMDA receptors.
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Affiliation(s)
- Wei Han
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - James P Allen
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Gil H Shaulsky
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology (W.H., H.Y., J.P.A., S.K., G.H.S., R.E.P., S.F.T., S.J.M.) and Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Emory University, Atlanta, Georgia (W.H., H.Y., J.P.A., S.K., G.H.S., S.F.T., S.J.M.)
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15
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Kysilov B, Hrcka Krausova B, Vyklicky V, Smejkalova T, Korinek M, Horak M, Chodounska H, Kudova E, Cerny J, Vyklicky L. Pregnane-based steroids are novel positive NMDA receptor modulators that may compensate for the effect of loss-of-function disease-associated GRIN mutations. Br J Pharmacol 2022; 179:3970-3990. [PMID: 35318645 DOI: 10.1111/bph.15841] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 02/24/2022] [Accepted: 03/04/2022] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE N-methyl-D-aspartate receptors (NMDARs) play a critical role in synaptic plasticity, and mutations in human genes encoding NMDAR subunits have been described in individuals with various neuropsychiatric disorders. Compounds with a positive allosteric effect are thought to compensate for reduced receptor function. EXPERIMENTAL APPROACH We have used whole-cell patch-clamp electrophysiology on recombinant rat NMDARs and human variants found in individuals with neuropsychiatric disorders, in combination with in silico modelling, to explore the site of action of novel epipregnanolone-based NMDAR modulators. KEY RESULTS Analysis of the action of 4-(20-oxo-5β-pregnan-3β-yl) butanoic acid (EPA-But) at the NMDAR indicates that the effect of this steroid with a "bent" structure is different from that of cholesterol and oxysterols and shares a disuse-dependent mechanism of NMDAR potentiation with the "planar" steroid 20-oxo-pregn-5-en-3β-yl sulfate (PE-S). The potentiating effects of EPA-But and PE-S are additive. Alanine scan mutagenesis identified residues that reduce the potentiating effect of EPA-But. No correlation was found between the effects of EPA-But and PE-S at mutated receptors that were less sensitive to either steroid. The relative degree of potentiation induced by the two steroids also differed in human NMDARs carrying rare variants of hGluN1 or hGluN2B subunits found in individuals with neuropsychiatric disorders, including intellectual disability, epilepsy, developmental delay, and autism spectrum disorder. CONCLUSION AND IMPLICATIONS Our results show novel sites of action for pregnanolones at the NMDAR and provide an opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with glutamatergic system hypofunction.
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Affiliation(s)
- Bohdan Kysilov
- Institute of Physiology CAS, Prague 4, Czech Republic.,Third Faculty of Medicine, Charles University in Prague, Prague 10, Czech Republic
| | | | | | | | | | - Martin Horak
- Institute of Physiology CAS, Prague 4, Czech Republic
| | - Hana Chodounska
- Institute of Organic Chemistry and Biochemistry CAS, Prague 6, Czech Republic
| | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry CAS, Prague 6, Czech Republic
| | - Jiri Cerny
- Institute of Physiology CAS, Prague 4, Czech Republic
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16
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Xu Q, Hu M, Li J, Ma X, Chu Z, Zhu Q, Zhang Y, Zhu P, Huang Y, He G. Discovery of novel brain-penetrant GluN2B NMDAR antagonists via pharmacophore-merging strategy as anti-stroke therapeutic agents. Eur J Med Chem 2022; 227:113876. [PMID: 34710748 DOI: 10.1016/j.ejmech.2021.113876] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/23/2021] [Accepted: 09/26/2021] [Indexed: 01/01/2023]
Abstract
In this work, a novel structural series of brain-penetrant GluN2B NMDAR antagonists were designed, synthesized and biologically evaluated as anti-stroke therapeutic agents via merging the structures of NBP and known GluN2B ligands. Approximately half of them exhibited superior neuroprotective activity to NBP against NMDA-induced neurotoxicity in hippocampal neurons at 10 μM, and compound 45e and 45f exerted equipotent activity to ifenprodil, an approved GluN2B- selective NMDAR antagonist. In particular, 45e, with the most potent neuroprotective activity throughout this series, displayed dramatically enhanced activity (Ki = 3.26 nM) compared to ifenprodil (Ki = 14.80 nM) in Radioligand Competitive Binding Assay, and remarkable inhibition (IC50 = 79.32 nM) against GluN1/GluN2B receptor-mediated current in Patch Clamp Assay. Meanwhile, 45e and its enantiomers exhibited low inhibition rate against the current mediated by other investigated receptors at the concentration of 10 μM, indicating their favorable selectivity for GluN1/GluN2B. In the rat model of middle cerebral artery ischemia (MCAO), 45e exerted comparable therapeutic efficacy to ifenprodil at the same dosage. In addition to the attractive in vitro and in vivo potency, 45e displayed a favorable bioavailability (F = 63.37%) and an excellent brain exposure. In further repeated dose toxicity experiments, compound 45e demonstrated an acceptable safety profile. With the above merits, 45e is worthy of further functional investigation as a novel anti-stroke therapeutic agent.
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Affiliation(s)
- Qinlong Xu
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China; Hefei Institute of Pharmaceutical Industry Co., Ltd., Hefei, 230088, China
| | - Mengqi Hu
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China; Hefei Institute of Pharmaceutical Industry Co., Ltd., Hefei, 230088, China
| | - Jiaming Li
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China.
| | - Xiaodong Ma
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China
| | - Zhaoxing Chu
- Hefei Institute of Pharmaceutical Industry Co., Ltd., Hefei, 230088, China; China Pharmaceutical University, Nanjing, 210009, China
| | - Qihua Zhu
- China Pharmaceutical University, Nanjing, 210009, China
| | - Yanchun Zhang
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China
| | - Panhu Zhu
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China
| | - Yuanzheng Huang
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, 230012, China
| | - Guangwei He
- Hefei Institute of Pharmaceutical Industry Co., Ltd., Hefei, 230088, China
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17
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Paradigmatic De Novo GRIN1 Variants Recapitulate Pathophysiological Mechanisms Underlying GRIN1-Related Disorder Clinical Spectrum. Int J Mol Sci 2021; 22:ijms222312656. [PMID: 34884460 PMCID: PMC8657601 DOI: 10.3390/ijms222312656] [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: 10/05/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 11/24/2022] Open
Abstract
Background: GRIN-related disorders (GRD), the so-called grinpathies, is a group of rare encephalopathies caused by mutations affecting GRIN genes (mostly GRIN1, GRIN2A and GRIN2B genes), which encode for the GluN subunit of the N-methyl D-aspartate (NMDA) type ionotropic glutamate receptors. A growing number of functional studies indicate that GRIN-encoded GluN1 subunit disturbances can be dichotomically classified into gain- and loss-of-function, although intermediate complex scenarios are often present. Methods: In this study, we aimed to delineate the structural and functional alterations of GRIN1 disease-associated variants, and their correlations with clinical symptoms in a Spanish cohort of 15 paediatric encephalopathy patients harbouring these variants. Results: Patients harbouring GRIN1 disease-associated variants have been clinically deeply-phenotyped. Further, using computational and in vitro approaches, we identified different critical checkpoints affecting GluN1 biogenesis (protein stability, subunit assembly and surface trafficking) and/or NMDAR biophysical properties, and their association with GRD clinical symptoms. Conclusions: Our findings show a strong correlation between GRIN1 variants-associated structural and functional outcomes. This structural-functional stratification provides relevant insights of genotype-phenotype association, contributing to future precision medicine of GRIN1-related encephalopathies.
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18
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Benke TA, Park K, Krey I, Camp CR, Song R, Ramsey AJ, Yuan H, Traynelis SF, Lemke J. Clinical and therapeutic significance of genetic variation in the GRIN gene family encoding NMDARs. Neuropharmacology 2021; 199:108805. [PMID: 34560056 PMCID: PMC8525401 DOI: 10.1016/j.neuropharm.2021.108805] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 02/03/2023]
Abstract
Considerable genetic variation of N-methyl-d-aspartate receptors (NMDARs) has recently become apparent, with many hundreds of de novo variants identified through widely available clinical genetic testing. Individuals with GRIN variants present with neurological conditions such as epilepsy, autism, intellectual disability (ID), movement disorders, schizophrenia and behavioral disorders. Determination of the functional consequence of genetic variation for NMDARs should lead to precision therapeutics. Furthermore, genetic animal models harboring human variants have the potential to reveal mechanisms that are shared among different neurological conditions, providing strategies that may allow treatment of individuals who are refractory to therapy. Preclinical studies in animal models and small open label trials in humans support this idea. However, additional functional data for variants and animal models corresponding to multiple individuals with the same genotype are needed to validate this approach and to lead to thoughtfully designed, randomized, placebo-controlled clinical trials, which could provide data in order to determine safety and efficacy of potential precision therapeutics.
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Affiliation(s)
- Tim A Benke
- Departments of Pediatrics, Pharmacology, Neurology, and Otolaryngology, University of Colorado, School of Medicine and Children's Hospital Colorado, United States.
| | - Kristen Park
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, United States
| | - Ilona Krey
- Institute of Human Genetics, Leipzig Medical Center, Leipzig, Germany
| | - Chad R Camp
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Rui Song
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Amy J Ramsey
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Johannes Lemke
- Institute of Human Genetics, Leipzig Medical Center, Leipzig, Germany
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19
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Pejčić A, Janković SM, Đešević M, Gojak R, Lukić S, Marković N, Milosavljević M. Novel and emerging therapeutics for genetic epilepsies. Expert Rev Neurother 2021; 21:1283-1301. [PMID: 34633254 DOI: 10.1080/14737175.2021.1992275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Disease-specific treatments are available only for a minority of patients with genetic epilepsies, while the rest are treated with anticonvulsants, which are ineffective in almost one-third of patients. AREAS COVERED Recently approved and the most effective emerging therapeutics under development for the treatment of genetic epilepsies are overviewed after systematic search and analysis of relevant literature. EXPERT OPINION New and emerging drugs for genetic epilepsies exploit one of the two approaches: inhibiting hyperactive brain foci through blocking excitatory or augmenting inhibitory neurotransmission, or correcting the underlying genetic defect. The first is limited by insufficient selectivity of available compounds, and the second by imperfection of currently used vectors of genetic material, unselective and transient transgene expression. Besides, the treatment may come too late, after structural abnormalities and epilepsy deterioration takes place. However, with recent improvements, we can expect to see soon gradual decline in the number of patients with therapy-resistant genetic epilepsies.
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Affiliation(s)
- Ana Pejčić
- University of Kragujevac, Faculty of Medical Sciences, Kragujevac, Serbia
| | | | - Miralem Đešević
- Private Policlinic Center Eurofar Sarajevo, Cardiology Department, Sarajevo, Bosnia and Herzegovina
| | - Refet Gojak
- Infectious diseases Clinic, Clinical Center University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Snežana Lukić
- University of Kragujevac, Faculty of Medical Sciences, Kragujevac, Serbia
| | - Nenad Marković
- University of Kragujevac, Faculty of Medical Sciences, Kragujevac, Serbia
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20
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Hansen KB, Wollmuth LP, Bowie D, Furukawa H, Menniti FS, Sobolevsky AI, Swanson GT, Swanger SA, Greger IH, Nakagawa T, McBain CJ, Jayaraman V, Low CM, Dell'Acqua ML, Diamond JS, Camp CR, Perszyk RE, Yuan H, Traynelis SF. Structure, Function, and Pharmacology of Glutamate Receptor Ion Channels. Pharmacol Rev 2021; 73:298-487. [PMID: 34753794 PMCID: PMC8626789 DOI: 10.1124/pharmrev.120.000131] [Citation(s) in RCA: 216] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many physiologic effects of l-glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, are mediated via signaling by ionotropic glutamate receptors (iGluRs). These ligand-gated ion channels are critical to brain function and are centrally implicated in numerous psychiatric and neurologic disorders. There are different classes of iGluRs with a variety of receptor subtypes in each class that play distinct roles in neuronal functions. The diversity in iGluR subtypes, with their unique functional properties and physiologic roles, has motivated a large number of studies. Our understanding of receptor subtypes has advanced considerably since the first iGluR subunit gene was cloned in 1989, and the research focus has expanded to encompass facets of biology that have been recently discovered and to exploit experimental paradigms made possible by technological advances. Here, we review insights from more than 3 decades of iGluR studies with an emphasis on the progress that has occurred in the past decade. We cover structure, function, pharmacology, roles in neurophysiology, and therapeutic implications for all classes of receptors assembled from the subunits encoded by the 18 ionotropic glutamate receptor genes. SIGNIFICANCE STATEMENT: Glutamate receptors play important roles in virtually all aspects of brain function and are either involved in mediating some clinical features of neurological disease or represent a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of this class of receptors will advance our understanding of many aspects of brain function at molecular, cellular, and system levels and provide new opportunities to treat patients.
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Affiliation(s)
- Kasper B Hansen
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Lonnie P Wollmuth
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Derek Bowie
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hiro Furukawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Frank S Menniti
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Alexander I Sobolevsky
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Geoffrey T Swanson
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Sharon A Swanger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Ingo H Greger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Terunaga Nakagawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chris J McBain
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Vasanthi Jayaraman
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chian-Ming Low
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Mark L Dell'Acqua
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Jeffrey S Diamond
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chad R Camp
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Riley E Perszyk
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hongjie Yuan
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Stephen F Traynelis
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
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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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22
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Xu Y, Song R, Chen W, Strong K, Shrey D, Gedela S, Traynelis SF, Zhang G, Yuan H. Recurrent seizure-related GRIN1 variant: Molecular mechanism and targeted therapy. Ann Clin Transl Neurol 2021; 8:1480-1494. [PMID: 34227748 PMCID: PMC8283169 DOI: 10.1002/acn3.51406] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Genetic variants in the GRIN genes that encode N-methyl-D-aspartate receptor (NMDAR) subunits have been identified in various neurodevelopmental disorders, including epilepsy. We identified a GRIN1 variant from an individual with early-onset epileptic encephalopathy, evaluated functional changes to NMDAR properties caused by the variant, and screened FDA-approved therapeutic compounds as potential treatments for the patient. METHODS Whole exome sequencing identified a missense variant in GRIN1. Electrophysiological recordings were made from Xenopus oocytes and transfected HEK cells to determine the NMDAR biophysical properties as well as the sensitivity to agonists and FDA-approved drugs that inhibit NMDARs. A beta-lactamase reporter assay in transfected HEK cells evaluated the effects of the variant on the NMDAR surface expression. RESULTS A recurrent de novo missense variant in GRIN1 (c.1923G>A, p.Met641Ile), which encodes the GluN1 subunit, was identified in a pediatric patient with drug-resistant seizures and early-onset epileptic encephalopathy. In vitro analysis indicates that GluN1-M641I containing NMDARs showed enhanced agonist potency and reduced Mg2+ block, which may be associated with the patient's phenotype. Results from screening FDA-approved drugs suggested that GluN1-M641I containing NMDARs are more sensitive to the NMDAR channel blockers memantine, ketamine, and dextromethorphan compared to the wild-type receptors. The addition of memantine to the seizure treatment regimen significantly reduced the patient's seizure burden. INTERPRETATION Our finding contributes to the understanding of the phenotype-genotype correlations of patients with GRIN1 gene variants, provides a molecular mechanism underlying the actions of this variant, and explores therapeutic strategies for treating GRIN1-related neurological conditions.
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Affiliation(s)
- Yuchen Xu
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
- Department of NeurologyXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Rui Song
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
- Department of NeurologyXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Wenjuan Chen
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
- Present address:
Department of PsychiatrySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
| | - Katie Strong
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
| | - Daniel Shrey
- Division of NeurologyChildren’s Hospital of Orange CountyOrangeCaliforniaUSA
- Department of PediatricsUniversity of California IrvineIrvineCaliforniaUSA
| | - Satyanarayana Gedela
- Division of NeurologyDepartment of PediatricsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Stephen F. Traynelis
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
- Center for Functional Evaluation of Rare Variants (CFERV)Emory University School of MedicineAtlantaGeorgiaUSA
| | - Guojun Zhang
- Division of NeurologyDepartment of PediatricsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical BiologyEmory University School of MedicineAtlantaGeorgiaUSA
- Center for Functional Evaluation of Rare Variants (CFERV)Emory University School of MedicineAtlantaGeorgiaUSA
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23
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Chaudhuri T, Chintalapati J, Hosur MV. Identification of 3'-UTR single nucleotide variants and prediction of select protein imbalance in mesial temporal lobe epilepsy patients. PLoS One 2021; 16:e0252475. [PMID: 34086756 PMCID: PMC8177469 DOI: 10.1371/journal.pone.0252475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/16/2021] [Indexed: 11/23/2022] Open
Abstract
The genetic influence in epilepsy, characterized by unprovoked and recurrent seizures, is through variants in genes critical to brain development and function. We have carried out variant calling in Mesial Temporal Lobe Epilepsy (MTLE) patients by mapping the RNA-Seq data available at SRA, NCBI, USA onto human genome assembly hg-19. We have identified 1,75,641 SNVs in patient samples. These SNVs are distributed over 14700 genes of which 655 are already known to be associated with epilepsy. Large number of variants occur in the 3'-UTR, which is one of the regions involved in the regulation of protein translation through binding of miRNAs and RNA-binding proteins (RBP). We have focused on studying the structure-function relationship of the 3'-UTR SNVs that are common to at-least 10 of the 35 patient samples. For the first time we find SNVs exclusively in the 3'-UTR of FGF12, FAR1, NAPB, SLC1A3, SLC12A6, GRIN2A, CACNB4 and FBXO28 genes. Structural modelling reveals that the variant 3'-UTR segments possess altered secondary and tertiary structures which could affect mRNA stability and binding of RBPs to form proper ribonucleoprotein (RNP) complexes. Secondly, these SNVs have either created or destroyed miRNA-binding sites, and molecular modeling reveals that, where binding sites are created, the additional miRNAs bind strongly to 3'-UTR of only variant mRNAs. These two factors affect protein production thereby creating an imbalance in the amounts of select proteins in the cell. We suggest that in the absence of missense and nonsense variants, protein-activity imbalances associated with MTLE patients can be caused through 3'-UTR variants in relevant genes by the mechanisms mentioned above. 3'-UTR SNV has already been identified as causative variant in the neurological disorder, Tourette syndrome. Inhibition of these miRNA-mRNA bindings could be a novel way of treating drug-resistant MTLE patients. We also suggest that joint occurrence of these SNVs could serve as markers for MTLE. We find, in the present study, SNV-mediated destruction of miRNA binding site in the 3'-UTR of the gene encoding glutamate receptor subunit, and, interestingly, overexpression of one of this receptor subunit is also associated with Febrile Seizures.
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Affiliation(s)
- Tanusree Chaudhuri
- Department of Natural Sciences and Engineering, National Institute of Advanced Studies, IISc campus, Bangalore, India
| | - Janaki Chintalapati
- CDAC-Centre for Development of Advanced Computing, Byappanahalli, Bangalore, India
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24
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Sapuppo A, Portale L, Massimino CR, Presti S, Tardino L, Marino S, Polizzi A, Falsaperla R, Praticò AD. GRIN2A and GRIN2B and Their Related Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractGlutamate is the most relevant excitatory neurotransmitter of the central nervous system; it binds with several receptors, including N-methyl-D-aspartate receptors (NMDARs), a subtype of ionotropic glutamate receptor that displays voltage-dependent block by Mg2+ and a high permeability to Ca2+. GRIN2A and GRIN2B genes encode the GluN2A and GluN2B subunits of the NMDARs, which play important roles in synaptogenesis, synaptic transmission, and synaptic plasticity, as well as contributing to neuronal loss and dysfunction in several neurological disorders. Recently, individuals with a range of childhood-onset drug-resistant epilepsies, such as Landau–Kleffner or Lennox–Gastaut syndrome, intellectual disability (ID), and other neurodevelopmental abnormalities have been found to carry mutations in GRIN2A and GRIN2B, with high variable expressivity in phenotype. The first one is found mainly in epilepsy-aphasia syndromes, while the second one mainly in autism, schizophrenia, and ID, such as autism spectrum disorders. Brain magnetic resonance imaging alterations are found in some patients, even if without a clear clinical correlation. At the same time, increasing data on genotype–phenotype correlation have been found, but this is still not fully demonstrated. There are no specific therapies for the treatment of correlated NMDARs epilepsy, although some evidence with memantine, an antagonist of glutamate receptor, is reported in the literature in selected cases with mutation determining a gain of function.
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Affiliation(s)
- Annamaria Sapuppo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Laura Portale
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Carmela R. Massimino
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Santiago Presti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Lucia Tardino
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Simona Marino
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Agata Polizzi
- Chair of Pediatrics, Department of Educational Sciences, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous Systemin Childhood, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
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25
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Johannessen Landmark C, Potschka H, Auvin S, Wilmshurst JM, Johannessen SI, Kasteleijn-Nolst Trenité D, Wirrell EC. The role of new medical treatments for the management of developmental and epileptic encephalopathies: Novel concepts and results. Epilepsia 2021; 62:857-873. [PMID: 33638459 DOI: 10.1111/epi.16849] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 12/20/2022]
Abstract
Developmental and epileptic encephalopathies (DEEs) are among the most challenging of all epilepsies to manage, given the exceedingly frequent and often severe seizure types, pharmacoresistance to conventional antiseizure medications, and numerous comorbidities. During the past decade, efforts have focused on development of new treatment options for DEEs, with several recently approved in the United States or Europe, including cannabidiol as an orphan drug in Dravet and Lennox-Gastaut syndromes and everolimus as a possible antiepileptogenic and precision drug for tuberous sclerosis complex, with its impact on the mammalian target of rapamycin pathway. Furthermore, fenfluramine, an old drug, was repurposed as a novel therapy in the treatment of Dravet syndrome. The evolution of new insights into pathophysiological processes of various DEEs provides possibilities to investigate novel and repurposed drugs and to place them into the context of their role in future management of these patients. The purpose of this review is to provide an overview of these new medical treatment options for the DEEs and to discuss the clinical implications of these results for improved treatment.
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Affiliation(s)
- Cecilie Johannessen Landmark
- Program for Pharmacy, Department of Life Sciences and Health, Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway.,National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.,Section for Clinical Pharmacology, Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilian University of Munich, Munich, Germany
| | - Stéphane Auvin
- Pediatric Neurology Department, Robert Debré Hospital, Public Hospital Network of Paris, Paris, France.,Mixed Unit of Research NeuroDiderot U1141, University of Paris, Paris, France
| | - Jo M Wilmshurst
- Paediatric Neurology Department, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Svein I Johannessen
- National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.,Section for Clinical Pharmacology, Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | | | - Elaine C Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Mayo Clinic, Rochester, Minnesota, USA
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26
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García-Recio A, Santos-Gómez A, Soto D, Julia-Palacios N, García-Cazorla À, Altafaj X, Olivella M. GRIN database: A unified and manually curated repertoire of GRIN variants. Hum Mutat 2020; 42:8-18. [PMID: 33252190 DOI: 10.1002/humu.24141] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/13/2020] [Accepted: 11/16/2020] [Indexed: 12/22/2022]
Abstract
Glutamatergic neurotransmission is crucial for brain development, wiring neuronal function, and synaptic plasticity mechanisms. Recent genetic studies showed the existence of autosomal dominant de novo GRIN gene variants associated with GRIN-related disorders (GRDs), a rare pediatric neurological disorder caused by N-methyl- d-aspartate receptor (NMDAR) dysfunction. Notwithstanding, GRIN variants identification is exponentially growing and their clinical, genetic, and functional annotations remain highly fragmented, representing a bottleneck in GRD patient's stratification. To shorten the gap between GRIN variant identification and patient stratification, we present the GRIN database (GRINdb), a publicly available, nonredundant, updated, and curated database gathering all available genetic, functional, and clinical data from more than 4000 GRIN variants. The manually curated GRINdb outputs on a web server, allowing query and retrieval of reported GRIN variants, and thus representing a fast and reliable bioinformatics resource for molecular clinical advice. Furthermore, the comprehensive mapping of GRIN variants' genetic and clinical information along NMDAR structure revealed important differences in GRIN variants' pathogenicity and clinical phenotypes, shedding light on GRIN-specific fingerprints. Overall, the GRINdb and web server is a resource for molecular stratification of GRIN variants, delivering clinical and investigational insights into GRDs. GRINdb is accessible at http://lmc.uab.es/grindb.
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Affiliation(s)
- Adrián García-Recio
- Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Ana Santos-Gómez
- Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,Neurophysiology Laboratory, Department of Biomedicine, Institute of Neurosciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - David Soto
- Neurophysiology Laboratory, Department of Biomedicine, Institute of Neurosciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Natalia Julia-Palacios
- Neurometabolic Unit, Department of Neurology, Hospital Sant Joan de Déu and CIBERER, Barcelona, Spain
| | - Àngels García-Cazorla
- Neurometabolic Unit, Department of Neurology, Hospital Sant Joan de Déu and CIBERER, Barcelona, Spain
| | - Xavier Altafaj
- Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,Neurophysiology Laboratory, Department of Biomedicine, Institute of Neurosciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Mireia Olivella
- School of International Studies, ESCI-UPF, Barcelona, Spain.,Bioinfomatics and Medical Statistics Group, University of Vic-Central University of Catalonia, Vic, Spain
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27
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Impact of predictive, preventive and precision medicine strategies in epilepsy. Nat Rev Neurol 2020; 16:674-688. [PMID: 33077944 DOI: 10.1038/s41582-020-0409-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2020] [Indexed: 12/15/2022]
Abstract
Over the last decade, advances in genetics, neuroimaging and EEG have enabled the aetiology of epilepsy to be identified earlier in the disease course than ever before. At the same time, progress in the study of experimental models of epilepsy has provided a better understanding of the mechanisms underlying the condition and has enabled the identification of therapies that target specific aetiologies. We are now witnessing the impact of these advances in our daily clinical practice. Thus, now is the time for a paradigm shift in epilepsy treatment from a reactive attitude, treating patients after the onset of epilepsy and the initiation of seizures, to a proactive attitude that is more broadly integrated into a 'P4 medicine' approach. This P4 approach, which is personalized, predictive, preventive and participatory, puts patients at the centre of their own care and, ultimately, aims to prevent the onset of epilepsy. This aim will be achieved by adapting epilepsy treatments not only to a given syndrome but also to a given patient and moving from the usual anti-seizure treatments to personalized treatments designed to target specific aetiologies. In this Review, we present the current state of this ongoing revolution, emphasizing the impact on clinical practice.
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28
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Johnson TN, Abduljalil K, Nicolas JM, Muglia P, Chanteux H, Nicolai J, Gillent E, Cornet M, Sciberras D. Use of a physiologically based pharmacokinetic-pharmacodynamic model for initial dose prediction and escalation during a paediatric clinical trial. Br J Clin Pharmacol 2020; 87:1378-1389. [PMID: 32822519 DOI: 10.1111/bcp.14528] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/31/2020] [Accepted: 08/07/2020] [Indexed: 11/29/2022] Open
Abstract
AIMS To build and verify a physiologically based pharmacokinetic (PBPK) model for radiprodil in adults and link this to a pharmacodynamic (PD) receptor occupancy (RO) model derived from in vitro data. Adapt this model to the paediatric population and predict starting and escalating doses in infants based on RO. Use the model to guide individualized dosing in a clinical trial in 2- to 14-month-old children with infantile spasms. METHODS A PBPK model for radiprodil was developed to investigate the systemic exposure of the drug after oral administration in fasted and fed adults; this was then linked to RO via a PD model. The model was then expanded to include developmental physiology and ontogeny to predict escalating doses in infants that would result in a specific RO of 20, 40 and 60% based on average unbound concentration following a twice daily (b.i.d.) dosing regimen. Dose progression in the clinical trial was based on observed concentration-time data against PBPK predictions. RESULTS For paediatric predictions, the elimination of radiprodil, based on experimental evidence, had no ontogeny. Predicted b.i.d. doses ranged from 0.04 mg/kg for 20% RO, 0.1 mg/kg for 40% RO to 0.21 mg/kg for 60% RO. For all infants recruited in the study, observed concentration-time data following the 0.04 mg/kg and subsequent doses were within the PBPK model predicted 5th and 95th percentiles. CONCLUSION To our knowledge, this is the first time a PBPK model linked to RO has been used to guide dose selection and escalation in the live phase of a paediatric clinical trial.
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29
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Auvin S, Avbersek A, Bast T, Chiron C, Guerrini R, Kaminski RM, Lagae L, Muglia P, Cross JH. Drug Development for Rare Paediatric Epilepsies: Current State and Future Directions. Drugs 2020; 79:1917-1935. [PMID: 31734883 DOI: 10.1007/s40265-019-01223-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rare diseases provide a challenge in the evaluation of new therapies. However, orphan drug development is of increasing interest because of the legislation enabling facilitated support by regulatory agencies through scientific advice, and the protection of the molecules with orphan designation. In the landscape of the rare epilepsies, very few syndromes, namely Dravet syndrome, Lennox-Gastaut syndrome and West syndrome, have been subject to orphan drug development. Despite orphan designations for rare epilepsies having dramatically increased in the past 10 years, the number of approved drugs remains limited and restricted to a handful of epilepsy syndromes. In this paper, we describe the current state of orphan drug development for rare epilepsies. We identified a large number of compounds currently under investigation, but mostly in the same rare epilepsy syndromes as in the past. A rationale for further development in rare epilepsies could be based on the match between the drug mechanisms of action and the knowledge of the causative gene mutation or by evidence from animal models. In case of the absence of strong pathophysiological hypotheses, exploratory/basket clinical studies could be helpful to identify a subpopulation that may benefit from the new drug. We provide some suggestions for future improvements in orphan drug development such as promoting paediatric drug investigations, better evaluation of the incidence and the prevalence, together with the natural history data, and the development of new primary outcomes.
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Affiliation(s)
- Stéphane Auvin
- PROTECT, INSERM U1141, Université de Paris, Paris, France. .,Service de Neurologie Pédiatrique, AP-HP, Hôpital Universitaire Robert-Debré, 48, Boulevard Sérurier, 75935, Paris Cedex 19, France.
| | | | - Thomas Bast
- The Kork Epilepsy Center, Kehl-Kork, Germany.,Medical Faculty of the University of Freiburg, Freiburg, Germany
| | - Catherine Chiron
- PROTECT, INSERM U1141, Université de Paris, Paris, France.,Service de Neurologie Pédiatrique, AP-HP, Hôpital Necker-Enfanst Malades, Paris, France
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Anna Meyer-University of Florence, Florence, Italy
| | - Rafal M Kaminski
- UCB Pharma, Braine-l'Alleud, Belgium.,Roche Pharma Research and Early Development (pRED), Roche Innovation Center, Basel, Switzerland
| | - Lieven Lagae
- Department Development and Regeneration, Section Paediatric Neurology, University Hospitals, University of Leuven, Leuven, Belgium
| | | | - J Helen Cross
- UCL NIHR BRC Great Ormond Street Institute of Child Health, London, UK
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Effects of GluN2A and GluN2B gain-of-function epilepsy mutations on synaptic currents mediated by diheteromeric and triheteromeric NMDA receptors. Neurobiol Dis 2020; 140:104850. [PMID: 32247039 DOI: 10.1016/j.nbd.2020.104850] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 02/19/2020] [Accepted: 03/29/2020] [Indexed: 01/19/2023] Open
Abstract
Mutations in synaptic NMDA receptors (NMDARs) are associated with epilepsy and neurodevelopmental disorders. The effects of several such mutations have been investigated in recombinantly-expressed NMDARs under conditions of steady-state activation. Such experiments provide only limited insight into how mutations affect NMDAR-mediated excitatory synaptic currents (EPSCs). The present study aimed to characterize the effects of the GluN2AN615K, GluN2BN615I and GluN2BV618G gain-of-function mutations on EPSCs mediated by diheteromeric GluN1/2A and GluN1/2B receptors and triheteromeric GluN1/2A/2B receptors, as these are the most abundant synaptic NMDARs in vivo. Subunit composition was controlled by studying 'artificial' synapses formed between cultured neurons (which provide presynaptic terminals) and HEK293 cells that express the NMDAR subunits of interest plus the synapse-promoting molecule, neuroligin-1B. When incorporated into diheteromeric receptors, all three mutations ablated voltage-dependent Mg2+ block of EPSCs, as previously shown. In addition, we were surprised to find that increasing external Mg2+ from 0 to 1 mM strongly enhanced the magnitude of EPSCs mediated by mutant diheteromers. In contrast, triheteromeric receptors exhibited normal voltage-dependent Mg2+ block. The GluN2AN615K mutation also slowed the decay of GluN1/2A/2B- but not GluN1/2A-mediated EPSCs. The GluN2BN615I mutation enhanced the magnitude of both GluN1/2B- and GluN1/2A/2B-mediated EPSCs. The GluN2BV618G mutation enhanced the magnitude of both GluN1/2B- and GluN1/2A/2B-mediated EPSCs, although these effects were partly compensated by a faster EPSC decay rate. The mutations also diminished the potency of the anti-epileptic pore-blocker, memantine, thus explaining the lack of memantine efficacy in patients with GluN2BN615I or GluN2BV618G mutations. Given these effects, the three mutations would be expected to enhance the cation influx rate and thereby contribute to epilepsy phenotypes.
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31
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Auvin S, Dozières-Puyravel B, Avbersek A, Sciberras D, Collier J, Leclercq K, Mares P, Kaminski RM, Muglia P. Radiprodil, a NR2B negative allosteric modulator, from bench to bedside in infantile spasm syndrome. Ann Clin Transl Neurol 2020; 7:343-352. [PMID: 32106360 PMCID: PMC7085998 DOI: 10.1002/acn3.50998] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 11/24/2022] Open
Abstract
Objective Infantile spasm syndrome (ISS) is an epileptic encephalopathy without established treatment after the failure to standard of care based on steroids and vigabatrin. Converging lines of evidence indicating a role of NR2B subunits of the N‐methyl‐D‐aspartate (NMDA) receptor on the onset of spams in ISS patients, prompted us to test radiprodil, a negative allosteric NR2B modulator in preclinical seizure models and in infants with ISS. Methods Radiprodil has been tested in three models, including pentylenetetrazole‐induced seizures in rats across different postnatal (PN) ages. Three infants with ISS have been included in a phase 1b escalating repeated dose study. Results Radiprodil showed the largest protective seizure effects in juvenile rats (maximum at PN12, corresponding to late infancy in humans). Three infants resistant to a combination of vigabatrin and prednisolone received individually titrated doses of radiprodil for up to 34 days. Radiprodil was safe and well tolerated in all three infants, and showed the expected pharmacokinetic profile. One infant became spasm‐free and two showed clinical improvement without reaching spasm‐freedom. After radiprodil withdrawal, the one infant continued to be spasm‐free, while the two others experienced seizure worsening requiring the use of the ketogenic diet and other antiepileptic drugs. Interpretation Radiprodil showed prominent anti‐seizure effect in juvenile animals, consistent with the prevalent expression of NR2B subunit of the NMDA receptor at this age in both rodents and humans. The clinical testing, although preliminary, showed that radiprodil is associated with a good safety and pharmacokinetic profile, and with the potential to control epileptic spasms.
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Affiliation(s)
- Stéphane Auvin
- Service de Neurologie Pédiatrique, Hôpital Robert Debré, Paris, France.,Université de Paris, INSERM U1141, F-75019, Paris, France
| | - Blandine Dozières-Puyravel
- Service de Neurologie Pédiatrique, Hôpital Robert Debré, Paris, France.,Université de Paris, INSERM U1141, F-75019, Paris, France
| | | | | | | | | | - Pavel Mares
- Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
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32
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Felbamate in the treatment of refractory epileptic spasms. Epilepsy Res 2020; 161:106284. [PMID: 32058261 DOI: 10.1016/j.eplepsyres.2020.106284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 11/24/2022]
Abstract
Several small case series provide conflicting impressions of the efficacy of felbamate for treatment of epileptic spasms. Using a large single-center cohort of children with epileptic spasms, we retrospectively evaluated the efficacy and safety of felbamate. We identified all patients with video-EEG confirmed epileptic spasms who were treated with felbamate at our center. We quantified felbamate exposure by calculating peak and weighted-average weight-based dose. Clinical response was defined as resolution of epileptic spasms for at least 28 days, beginning not more than 3 months after felbamate initiation. Electroclinical response was defined as clinical response accompanied by overnight video-EEG demonstrating freedom from epileptic spasms and hypsarrhythmia. Among a cohort of 476 infants, we identified 62 children who were treated with felbamate, of whom 58 had previously failed treatment with hormonal therapy or vigabatrin. Median peak and weighted-average felbamate dosages were 47 and 40 mg/kg/day, respectively. Five (8%) children were classified as clinical responders and two (3%) children were classified as electroclinical responders. Among 17 patients with latency from epileptic spasms onset to felbamate initiation of less than 12 months, we observed 4 (24%) clinical responders. This study suggests that felbamate may be efficacious for treatment of epileptic spasms and that further rigorous study is warranted.
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33
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Smith RS, Walsh CA. Ion Channel Functions in Early Brain Development. Trends Neurosci 2020; 43:103-114. [PMID: 31959360 PMCID: PMC7092371 DOI: 10.1016/j.tins.2019.12.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/08/2019] [Accepted: 12/10/2019] [Indexed: 12/12/2022]
Abstract
During prenatal brain development, ion channels are ubiquitous across several cell types, including progenitor cells and migrating neurons but their function has not been clear. In the past, ion channel dysfunction has been primarily studied in the context of postnatal, differentiated neurons that fire action potentials - notably ion channels mutated in the epilepsies - yet data now support a surprising role in prenatal human brain disorders as well. Modern gene discovery approaches have identified defective ion channels in individuals with cerebral cortex malformations, which reflect abnormalities in early-to-middle stages of embryonic development (prior to ubiquitous action potentials). These human genetics studies and recent in utero animal modeling work suggest that precise control of ionic flux (calcium, sodium, and potassium) contributes to in utero developmental processes such as neural proliferation, migration, and differentiation.
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Affiliation(s)
- Richard S Smith
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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34
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Li J, Zhang J, Tang W, Mizu RK, Kusumoto H, XiangWei W, Xu Y, Chen W, Amin JB, Hu C, Kannan V, Keller SR, Wilcox WR, Lemke JR, Myers SJ, Swanger SA, Wollmuth LP, Petrovski S, Traynelis SF, Yuan H. De novo GRIN variants in NMDA receptor M2 channel pore-forming loop are associated with neurological diseases. Hum Mutat 2019; 40:2393-2413. [PMID: 31429998 DOI: 10.1002/humu.23895] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/08/2019] [Accepted: 08/14/2019] [Indexed: 12/21/2022]
Abstract
N-methyl-D-aspartate receptors (NMDARs) mediate slow excitatory postsynaptic transmission in the central nervous system, thereby exerting a critical role in neuronal development and brain function. Rare genetic variants in the GRIN genes encoding NMDAR subunits segregated with neurological disorders. Here, we summarize the clinical presentations for 18 patients harboring 12 de novo missense variants in GRIN1, GRIN2A, and GRIN2B that alter residues in the M2 re-entrant loop, a region that lines the pore and is intolerant to missense variation. These de novo variants were identified in children with a set of neurological and neuropsychiatric conditions. Evaluation of the receptor cell surface expression, pharmacological properties, and biophysical characteristics show that these variants can have modest changes in agonist potency, proton inhibition, and surface expression. However, voltage-dependent magnesium inhibition is significantly reduced in all variants. The NMDARs hosting a single copy of a mutant subunit showed a dominant reduction in magnesium inhibition for some variants. These variant NMDARs also show reduced calcium permeability and single-channel conductance, as well as altered open probability. The data suggest that M2 missense variants increase NMDAR charge transfer in addition to varied and complex influences on NMDAR functional properties, which may underlie the patients' phenotypes.
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Affiliation(s)
- Jia Li
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Jin Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Weiting Tang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Ruth K Mizu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Hirofumi Kusumoto
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Wenshu XiangWei
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wenjuan Chen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Johansen B Amin
- Department of Neurobiology & Behavior, Stony Brook University School of Medicine, Stony Brook, New York
| | - Chun Hu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Varun Kannan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Stephanie R Keller
- Division of Pediatric Neurology, Emory University School of Medicine, Atlanta, Georgia
| | - William R Wilcox
- Division of Medical Genetics, Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia.,Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia
| | - Sharon A Swanger
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Lonnie P Wollmuth
- Department of Neurobiology & Behavior, Stony Brook University School of Medicine, Stony Brook, New York
| | - Slavé Petrovski
- Department of Medicine, The University of Melbourne, Austin Health and Royal Melbourne Hospital, Melbourne, VIC, Australia.,Centre for Genomics Research, Discovery Sciences, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia.,Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia.,Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia
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Kobylarek D, Iwanowski P, Lewandowska Z, Limphaibool N, Szafranek S, Labrzycka A, Kozubski W. Advances in the Potential Biomarkers of Epilepsy. Front Neurol 2019; 10:685. [PMID: 31312171 PMCID: PMC6614180 DOI: 10.3389/fneur.2019.00685] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is a group of chronic neurological disorders characterized by recurrent, spontaneous, and unpredictable seizures. It is one of the most common neurological disorders, affecting tens of millions of people worldwide. Comprehensive studies on epilepsy in recent decades have revealed the complexity of epileptogenesis, in which immunological processes, epigenetic modifications, and structural changes in neuronal tissues have been identified as playing a crucial role. This review discusses the recent advances in the biomarkers of epilepsy. We evaluate the possible molecular background underlying the clinical changes observed in recent studies, focusing on therapeutic investigations, and the evidence of their safety and efficacy in the human population. This article reviews the pathophysiology of epilepsy, including recent reports on the effects of oxidative stress and hypoxia, and focuses on specific biomarkers and their clinical implications, along with further perspectives in epilepsy research.
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Affiliation(s)
- Dominik Kobylarek
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Piotr Iwanowski
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Zuzanna Lewandowska
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Sara Szafranek
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Anita Labrzycka
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Wojciech Kozubski
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
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Fjelldal MF, Freyd T, Evenseth LM, Sylte I, Ring A, Paulsen RE. Exploring the overlapping binding sites of ifenprodil and EVT-101 in GluN2B-containing NMDA receptors using novel chicken embryo forebrain cultures and molecular modeling. Pharmacol Res Perspect 2019; 7:e00480. [PMID: 31164987 PMCID: PMC6543015 DOI: 10.1002/prp2.480] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022] Open
Abstract
N-methyl-d-aspartate receptors (NMDAR) are widely expressed in the brain. GluN2B subunit-containing NMDARs has recently attracted significant attention as potential pharmacological targets, with emphasis on the functional properties of allosteric antagonists. We used primary cultures from chicken embryo forebrain (E10), expressing native GluN2B-containing NMDA receptors as a novel model system. Comparing the inhibition of calcium influx by well-known GluN2B subunit-specific allosteric antagonists, the following rank order of potency was found: EVT-101 (EC 50 22 ± 8 nmol/L) > Ro 25-6981 (EC 50 60 ± 30 nmol/L) > ifenprodil (EC 50 100 ± 40 nmol/L) > eliprodil (EC 50 1300 ± 700 nmol/L), similar to previous observations in rat cortical cultures and cell lines overexpressing chimeric receptors. The less explored Ro 04-5595 had an EC 50 of 186 ± 32 nmol/L. Venturing to explain the differences in potency, binding properties were further studied by in silico docking and molecular dynamics simulations using x-ray crystal structures of GluN1/GluN2B amino terminal domain. We found that Ro 04-5595 was predicted to bind the recently discovered EVT-101 binding site, not the ifenprodil-binding site. The EVT-101 binding pocket appears to accommodate more structurally different ligands than the ifenprodil-binding site, and contains residues essential in ligand interactions necessary for calcium influx inhibition. For the ifenprodil site, the less effective antagonist (eliprodil) fails to interact with key residues, while in the EVT-101 pocket, difference in potency might be explained by differences in ligand-receptor interaction patterns.
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Affiliation(s)
- Marthe F. Fjelldal
- Department of Pharmaceutical BiosciencesSchool of PharmacyUniversity of OsloOsloNorway
- Norwegian Defence Research EstablishmentKjellerNorway
- Realomics Strategic Research InitiativeOsloNorway
| | - Thibaud Freyd
- Molecular Pharmacology and ToxicologyDepartment of Medical BiologyUniversity of Tromsø—The Arctic University of NorwayTromsøNorway
- Department of ChemistryHylleraas Centre for Quantum Molecular SciencesUniversity of OsloOsloNorway
| | - Linn M. Evenseth
- Molecular Pharmacology and ToxicologyDepartment of Medical BiologyUniversity of Tromsø—The Arctic University of NorwayTromsøNorway
| | - Ingebrigt Sylte
- Molecular Pharmacology and ToxicologyDepartment of Medical BiologyUniversity of Tromsø—The Arctic University of NorwayTromsøNorway
| | - Avi Ring
- Norwegian Defence Research EstablishmentKjellerNorway
| | - Ragnhild E. Paulsen
- Department of Pharmaceutical BiosciencesSchool of PharmacyUniversity of OsloOsloNorway
- Realomics Strategic Research InitiativeOsloNorway
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Coughlin Q, Hopper AT, Blanco MJ, Tirunagaru V, Robichaud AJ, Doller D. Allosteric Modalities for Membrane-Bound Receptors: Insights from Drug Hunting for Brain Diseases. J Med Chem 2019; 62:5979-6002. [PMID: 30721063 DOI: 10.1021/acs.jmedchem.8b01651] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Medicinal chemists are accountable for embedding the appropriate drug target profile into the molecular architecture of a clinical candidate. An accurate characterization of the functional effects following binding of a drug to its biological target is a fundamental step in the discovery of new medicines, informing the translation of preclinical efficacy and safety observations into human trials. Membrane-bound proteins, particularly ion channels and G protein-coupled receptors (GPCRs), are biological targets prone to allosteric modulation. Investigations using allosteric drug candidates and chemical tools suggest that their functional effects may be tailored with a high degree of translational alignment, making them molecular tools to correct pathophysiological functional tone and enable personalized medicine when a causative target-to-disease link is known. We present select examples of functional molecular fine-tuning of allosterism and discuss consequences relevant to drug design.
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Vyklicky V, Krausova B, Cerny J, Ladislav M, Smejkalova T, Kysilov B, Korinek M, Danacikova S, Horak M, Chodounska H, Kudova E, Vyklicky L. Surface Expression, Function, and Pharmacology of Disease-Associated Mutations in the Membrane Domain of the Human GluN2B Subunit. Front Mol Neurosci 2018; 11:110. [PMID: 29681796 PMCID: PMC5897658 DOI: 10.3389/fnmol.2018.00110] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/20/2018] [Indexed: 12/20/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs), glutamate-gated ion channels, mediate signaling at the majority of excitatory synapses in the nervous system. Recent sequencing data for neurological and psychiatric patients have indicated numerous mutations in genes encoding for NMDAR subunits. Here, we present surface expression, functional, and pharmacological analysis of 11 de novo missense mutations of the human hGluN2B subunit (P553L; V558I; W607C; N615I; V618G; S628F; E657G; G820E; G820A; M824R; L825V) located in the pre-M1, M1, M2, M3, and M4 membrane regions. These variants were identified in patients with intellectual disability, developmental delay, epileptic symptomatology, and autism spectrum disorder. Immunofluorescence microscopy indicated that the ratio of surface-to-total NMDAR expression was reduced for hGluN1/hGluN2B(S628F) receptors and increased for for hGluN1/hGluN2B(G820E) receptors. Electrophysiological recordings revealed that agonist potency was altered in hGluN1/hGluN2B(W607C; N615I; and E657G) receptors and desensitization was increased in hGluN1/hGluN2B(V558I) receptors. The probability of channel opening of hGluN1/hGluN2B (V558I; W607C; V618G; and L825V) receptors was diminished ~10-fold when compared to non-mutated receptors. Finally, the sensitivity of mutant receptors to positive allosteric modulators of the steroid origin showed that glutamate responses induced in hGluN1/hGluN2B(V558I; W607C; V618G; and G820A) receptors were potentiated by 59–96% and 406-685% when recorded in the presence of 20-oxo-pregn-5-en-3β-yl sulfate (PE-S) and androst-5-en-3β-yl hemisuccinate (AND-hSuc), respectively. Surprisingly hGluN1/hGluN2B(L825V) receptors were strongly potentiated, by 197 and 1647%, respectively, by PE-S and AND-hSuc. Synaptic-like responses induced by brief glutamate application were also potentiated and the deactivation decelerated. Further, we have used homology modeling based on the available crystal structures of GluN1/GluN2B NMDA receptor followed by molecular dynamics simulations to try to relate the functional consequences of mutations to structural changes. Overall, these data suggest that de novo missense mutations of the hGluN2B subunit located in membrane domains lead to multiple defects that manifest by the NMDAR loss of function that can be rectified by steroids. Our results provide an opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with hypofunction of the glutamatergic system.
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Affiliation(s)
- Vojtech Vyklicky
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Barbora Krausova
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Jiri Cerny
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Marek Ladislav
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia.,Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Tereza Smejkalova
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Bohdan Kysilov
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Miloslav Korinek
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Sarka Danacikova
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia.,Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Martin Horak
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
| | - Hana Chodounska
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences (CAS), Prague, Czechia
| | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences (CAS), Prague, Czechia
| | - Ladislav Vyklicky
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences (CAS), Prague, Czechia
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XiangWei W, Jiang Y, Yuan H. De Novo Mutations and Rare Variants Occurring in NMDA Receptors. CURRENT OPINION IN PHYSIOLOGY 2017; 2:27-35. [PMID: 29756080 DOI: 10.1016/j.cophys.2017.12.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A significant number of variants/mutations in the N-methyl-D-aspartate glutamatergic receptor (NMDAR) gene family (GRIN) have been identified along with stunning advances in the technologies of next generation of whole-exome sequencing. Mutations in human GRIN genes are distributed throughout the entire gene, from amino terminal domain to C-terminal domain, in patients with various neuropsychiatric disorders, including autism spectrum disorders, epilepsy, intellectual disability, attention deficit hyperactivity disorder, and schizophrenia. Analyzing the currently available human genetic variations illustrates the genetic variation intolerance to missense mutations differs significantly among domains within the GRIN genes. Functional analyses of these mutations and their pharmacological profiles provide the first opportunity to understand the molecular mechanism and targeted therapeutic strategies for these neurological and psychiatric disorders, as well as unfold novel clues to channel function.
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Affiliation(s)
- Wenshu XiangWei
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing 100034, China
| | - Yuwu Jiang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing 100034, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing 100069, China
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA.,Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA
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Ion permeation in ionotropic glutamate receptors: Still dynamic after all these years. CURRENT OPINION IN PHYSIOLOGY 2017; 2:36-41. [PMID: 29607422 DOI: 10.1016/j.cophys.2017.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate the vast majority of fast synaptic transmission in the nervous system. When the iGluR ion channel is in the open or conducting conformation, it is non-selective for monovalent cations, driving membrane excitation. Often the channel is also permeable to Ca2+. This process of Ca2+ permeation and its physiological and pathological consequences depend strongly on the specific iGluR subtype as well as the specific subunits in the oligomeric complex. Recent evidence has highlighted additional levels of diversity to this process including a dependence on specific auxiliary subunits in non-NMDARs and post-translational modifications in NMDARs. Various de novo missense mutations associated with neurological disease in NMDAR subunits have been identified in regions critical to Ca2+ influx. These features highlight the dynamics of Ca2+ influx mediated by iGluRs and its critical role in synaptic physiology and pathology.
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41
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Mutations of N-Methyl-D-Aspartate Receptor Subunits in Epilepsy. Neurosci Bull 2017; 34:549-565. [PMID: 29124671 DOI: 10.1007/s12264-017-0191-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/19/2017] [Indexed: 01/31/2023] Open
Abstract
Epilepsy is one of the most common neurological diseases. Of all cases, 70%-80% are considered to be due to genetic factors. In recent years, a large number of genes have been identified as being involved in epilepsy. Among them, N-methyl-D-aspartate receptor (NMDAR) subunit-encoding genes represent a large proportion, suggesting an important role for NMDARs in epilepsy. In this review, we summarize and analyze the genotypes, functional alterations, and clinical aspects of NMDAR subunit mutations/variants identified from patients with epilepsy. These data will help to throw light upon the pathogenicity of these NMDAR mutations and advance our understanding of the subtle and complicated role of NMDARs in epilepsy. It will also offer new insights into precision therapy for this disorder.
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