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Sullivan MT, Tidball P, Yan Y, Intson K, Chen W, Xu Y, Venkatesan S, Horsfall W, Georgiou J, Finnie PSB, Lambe EK, Traynelis SF, Salahpour A, Yuan H, Collingridge GL, Ramsey AJ. Grin1 Y 647 S/+ Mice: A Preclinical Model of GRIN1 -Related Neurodevelopmental Disorder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.21.608984. [PMID: 39229143 PMCID: PMC11370376 DOI: 10.1101/2024.08.21.608984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Objective GRIN1 -related neurodevelopmental disorder ( GRIN1 -NDD) is characterized by clinically significant variation in the GRIN1 gene, which encodes the obligatory GluN1 subunit of N-methyl-D-aspartate receptors (NMDARs). The identified p.Tyr647Ser (Y647S) variant - carried by a 33-year-old female with seizures and intellectual disability - is located in the M3 helix in the GluN1 transmembrane domain. This study builds upon initial in vitro investigations of the functional impacts of the GRIN1 Y647S variant and examines its in vivo consequences in a mouse model. Methods To investigate in vitro functional impacts of NMDARs containing GluN1-Y647S variant subunits, GluN1-Y647S was co-expressed with wildtype GluN2A or GluN2B subunits in Xenopus laevis oocytes and HEK cells. Grin1 Y647S/+ mice were created by CRISPR-Cas9 endonuclease-mediated transgenesis and the molecular, electrophysiological, and behavioural consequences of the variant were examined. Results In vitro , NMDARs containing GluN1-Y647S show altered sensitivity to endogenous agonists and negative allosteric modulators, and reduced cell surface trafficking. Grin1 Y647S/+ mice displayed a reduction in whole brain GluN1 levels and deficiency in NMDAR-mediated synaptic transmission in the hippocampus. Behaviourally, Grin1 Y647S/+ mice exhibited spontaneous seizures, altered vocalizations, muscle strength, sociability, and problem-solving. Interpretation The Y647S variant confers a complex in vivo phenotype, which reflects largely diminished properties of NMDAR function. As a result, Grin1 Y647S/+ mice display atypical behaviour in domains relevant to the clinical characteristics of GRIN1 -NDD and the individual carrying the variant. Ultimately, the characterization of Grin1 Y647S/+ mice accomplished in the present work expands our understanding of the mechanisms underlying GRIN1 -NDD and provides a foundation for the development of novel therapeutics.
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Duma GM, Cuozzo S, Wilson L, Danieli A, Bonanni P, Pellegrino G. Excitation/Inhibition balance relates to cognitive function and gene expression in temporal lobe epilepsy: a high density EEG assessment with aperiodic exponent. Brain Commun 2024; 6:fcae231. [PMID: 39056027 PMCID: PMC11272395 DOI: 10.1093/braincomms/fcae231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/22/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Patients with epilepsy are characterized by a dysregulation of excitation/inhibition balance (E/I). The assessment of E/I may inform clinicians during the diagnosis and therapy management, even though it is rarely performed. An accessible measure of the E/I of the brain represents a clinically relevant feature. Here, we exploited the exponent of the aperiodic component of the power spectrum of the electroencephalography (EEG) signal, as a non-invasive and cost-effective proxy of the E/I balance. We recorded resting-state activity with high-density EEG from 67 patients with temporal lobe epilepsy and 35 controls. We extracted the exponent of the aperiodic fit of the power spectrum from source-reconstructed EEG and tested differences between patients with epilepsy and controls. Spearman's correlation was performed between the exponent and clinical variables (age of onset, epilepsy duration and neuropsychology) and cortical expression of epilepsy-related genes derived from the Allen Human Brain Atlas. Patients with temporal lobe epilepsy showed a significantly larger exponent, corresponding to inhibition-directed E/I balance, in bilateral frontal and temporal regions. Lower E/I in the left entorhinal and bilateral dorsolateral prefrontal cortices corresponded to a lower performance of short-term verbal memory. Limited to patients with temporal lobe epilepsy, we detected a significant correlation between the exponent and the cortical expression of GABRA1, GRIN2A, GABRD, GABRG2, KCNA2 and PDYN genes. EEG aperiodic exponent maps the E/I balance non-invasively in patients with epilepsy and reveals a close relationship between altered E/I patterns, cognition and genetics.
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Affiliation(s)
- Gian Marco Duma
- Scientific Institute IRCCS E.Medea, Epilepsy and Clinical Neurophysiology Unit, 31015, Conegliano, Italy
| | - Simone Cuozzo
- Scientific Institute IRCCS E.Medea, Epilepsy and Clinical Neurophysiology Unit, 31015, Conegliano, Italy
| | - Luc Wilson
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alberto Danieli
- Scientific Institute IRCCS E.Medea, Epilepsy and Clinical Neurophysiology Unit, 31015, Conegliano, Italy
| | - Paolo Bonanni
- Scientific Institute IRCCS E.Medea, Epilepsy and Clinical Neurophysiology Unit, 31015, Conegliano, Italy
| | - Giovanni Pellegrino
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London N6A5C1, Canada
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Korinek M, Candelas Serra M, Abdel Rahman F, Dobrovolski M, Kuchtiak V, Abramova V, Fili K, Tomovic E, Hrcka Krausova B, Krusek J, Cerny J, Vyklicky L, Balik A, Smejkalova T. Disease-Associated Variants in GRIN1, GRIN2A and GRIN2B genes: Insights into NMDA Receptor Structure, Function, and Pathophysiology. Physiol Res 2024; 73:S413-S434. [PMID: 38836461 PMCID: PMC11412357 DOI: 10.33549/physiolres.935346] [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: 09/04/2024] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are a subtype of ionotropic glutamate receptors critical for synaptic transmission and plasticity, and for the development of neural circuits. Rare or de-novo variants in GRIN genes encoding NMDAR subunits have been associated with neurodevelopmental disorders characterized by intellectual disability, developmental delay, autism, schizophrenia, or epilepsy. In recent years, some disease-associated variants in GRIN genes have been characterized using recombinant receptors expressed in non-neuronal cells, and a few variants have also been studied in neuronal preparations or animal models. Here we review the current literature on the functional evaluation of human disease-associated variants in GRIN1, GRIN2A and GRIN2B genes at all levels of analysis. Focusing on the impact of different patient variants at the level of receptor function, we discuss effects on receptor agonist and co-agonist affinity, channel open probability, and receptor cell surface expression. We consider how such receptor-level functional information may be used to classify variants as gain-of-function or loss-of-function, and discuss the limitations of this classification at the synaptic, cellular, or system level. Together this work by many laboratories worldwide yields valuable insights into NMDAR structure and function, and represents significant progress in the effort to understand and treat GRIN disorders. Keywords: NMDA receptor , GRIN genes, Genetic variants, Electrophysiology, Synapse, Animal models.
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Affiliation(s)
- M Korinek
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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4
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Kellner S, Berlin S. Rescuing tri-heteromeric NMDA receptor function: the potential of pregnenolone-sulfate in loss-of-function GRIN2B variants. Cell Mol Life Sci 2024; 81:235. [PMID: 38795169 PMCID: PMC11127902 DOI: 10.1007/s00018-024-05243-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 05/27/2024]
Abstract
N-methyl-D-aspartate receptors (NMDARs emerging from GRIN genes) are tetrameric receptors that form diverse channel compositions in neurons, typically consisting of two GluN1 subunits combined with two GluN2(A-D) subunits. During prenatal stages, the predominant channels are di-heteromers with two GluN1 and two GluN2B subunits due to the high abundance of GluN2B subunits. Postnatally, the expression of GluN2A subunits increases, giving rise to additional subtypes, including GluN2A-containing di-heteromers and tri-heteromers with GluN1, GluN2A, and GluN2B subunits. The latter emerge as the major receptor subtype at mature synapses in the hippocampus. Despite extensive research on purely di-heteromeric receptors containing two identical GRIN variants, the impact of a single variant on the function of other channel forms, notably tri-heteromers, is lagging. In this study, we systematically investigated the effects of two de novo GRIN2B variants (G689C and G689S) in pure, mixed di- and tri-heteromers. Our findings reveal that incorporating a single variant in mixed di-heteromers or tri-heteromers exerts a dominant negative effect on glutamate potency, although 'mixed' channels show improved potency compared to pure variant-containing di-heteromers. We show that a single variant within a receptor complex does not impair the response of all receptor subtypes to the positive allosteric modulator pregnenolone-sulfate (PS), whereas spermine completely fails to potentiate tri-heteromers containing GluN2A and -2B-subunits. We examined PS on primary cultured hippocampal neurons transfected with the variants, and observed a positive impact over current amplitudes and synaptic activity. Together, our study supports previous observations showing that mixed di-heteromers exhibit improved glutamate potency and extend these findings towards the exploration of the effect of Loss-of-Function variants over tri-heteromers. Notably, we provide an initial and crucial demonstration of the beneficial effects of GRIN2B-relevant potentiators on tri-heteromers. Our results underscore the significance of studying how different variants affect distinct receptor subtypes, as these effects cannot be inferred solely from observations made on pure di-heteromers. Overall, this study contributes to ongoing efforts to understand the pathophysiology of GRINopathies and provides insights into potential treatment strategies.
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Affiliation(s)
- Shai Kellner
- Dept. of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 1 Efron Bat Galim, Haifa, 3525433, Israel
| | - Shai Berlin
- Dept. of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 1 Efron Bat Galim, Haifa, 3525433, Israel.
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5
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Xu Y, Song R, Perszyk RE, Chen W, Kim S, Park KL, Allen JP, Nocilla KA, Zhang J, XiangWei W, Tankovic A, McDaniels ED, Sheikh R, Mizu RK, Karamchandani MM, Hu C, Kusumoto H, Pecha J, Cappuccio G, Gaitanis J, Sullivan J, Shashi V, Petrovski S, Jauss RT, Lee HK, Bozarth X, Lynch DR, Helbig I, Pierson TM, Boerkoel CF, Myers SJ, Lemke JR, Benke TA, Yuan H, Traynelis SF. De novo GRIN variants in M3 helix associated with neurological disorders control channel gating of NMDA receptor. Cell Mol Life Sci 2024; 81:153. [PMID: 38538865 PMCID: PMC10973091 DOI: 10.1007/s00018-023-05069-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 05/18/2024]
Abstract
N-methyl-D-aspartate receptors (NMDARs) are members of the glutamate receptor family and participate in excitatory postsynaptic transmission throughout the central nervous system. Genetic variants in GRIN genes encoding NMDAR subunits are associated with a spectrum of neurological disorders. The M3 transmembrane helices of the NMDAR couple directly to the agonist-binding domains and form a helical bundle crossing in the closed receptors that occludes the pore. The M3 functions as a transduction element whose conformational change couples ligand binding to opening of an ion conducting pore. In this study, we report the functional consequences of 48 de novo missense variants in GRIN1, GRIN2A, and GRIN2B that alter residues in the M3 transmembrane helix. These de novo variants were identified in children with neurological and neuropsychiatric disorders including epilepsy, developmental delay, intellectual disability, hypotonia and attention deficit hyperactivity disorder. All 48 variants in M3 for which comprehensive testing was completed produce a gain-of-function (28/48) compared to loss-of-function (9/48); 11 variants had an indeterminant phenotype. This supports the idea that a key structural feature of the M3 gate exists to stabilize the closed state so that agonist binding can drive channel opening. Given that most M3 variants enhance channel gating, we assessed the potency of FDA-approved NMDAR channel blockers on these variant receptors. These data provide new insight into the structure-function relationship of the NMDAR gate, and suggest that variants within the M3 transmembrane helix produce a gain-of-function.
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Affiliation(s)
- Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Neurology, The First Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Rui Song
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong, 250012, China
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Wenjuan Chen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, 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
| | - Kristen L Park
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - James P Allen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Kelsey A Nocilla
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Jing Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Wenshu XiangWei
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Anel Tankovic
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ellington D McDaniels
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Rehan Sheikh
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ruth K Mizu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Manish M Karamchandani
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Chun Hu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Hirofumi Kusumoto
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Joseph Pecha
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gerarda Cappuccio
- Department of Translational Medicine, Section of Pediatrics, Federico II University, Via Pansini 5, 80131, Naples, Italy
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - John Gaitanis
- Hasbro Children's Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Jennifer Sullivan
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, NC, USA
| | - Vandana Shashi
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, NC, USA
| | - Slave Petrovski
- Ce Department of Medicine, University of Melbourne, Austin Health, Melbourne, VIC, Australia
- Centre for Genomics Research, Discovery Sciences, AstraZeneca, BioPharmaceuticals R&D, Cambridge, UK
| | - Robin-Tobias Jauss
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Hyun Kyung Lee
- Provincial Medical Genetics Program, Department of Medical Genetics, University of British Columbia, Children's and Women's Health Centre of BC, Vancouver, B.C, V6H 3N1, Canada
| | - Xiuhua Bozarth
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
- Division of Pediatric Neurology, Department of Neurology, Seattle Children's Hospital, University of Washington, Seattle, WA, USA
| | - David R Lynch
- Departments of Pediatrics and Neurology, Perelman School of Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA
| | - Ingo Helbig
- Division of Child Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Tyler Mark Pierson
- Department of Pediatrics and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Center for the Undiagnosed Patient, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Cornelius F Boerkoel
- Provincial Medical Genetics Program, Department of Medical Genetics, University of British Columbia, Children's and Women's Health Centre of BC, Vancouver, B.C, V6H 3N1, Canada
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, 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
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
| | - Timothy A Benke
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, 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.
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, 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.
- Emory Neurodegenerative Disease Center, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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6
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Shepard N, Baez-Nieto D, Iqbal S, Kurganov E, Budnik N, Campbell AJ, Pan JQ, Sheng M, Farsi Z. Differential functional consequences of GRIN2A mutations associated with schizophrenia and neurodevelopmental disorders. Sci Rep 2024; 14:2798. [PMID: 38307912 PMCID: PMC10837427 DOI: 10.1038/s41598-024-53102-3] [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: 08/01/2023] [Accepted: 01/27/2024] [Indexed: 02/04/2024] Open
Abstract
Human genetic studies have revealed rare missense and protein-truncating variants in GRIN2A, encoding for the GluN2A subunit of the NMDA receptors, that confer significant risk for schizophrenia (SCZ). Mutations in GRIN2A are also associated with epilepsy and developmental delay/intellectual disability (DD/ID). However, it remains enigmatic how alterations to the same protein can result in diverse clinical phenotypes. Here, we performed functional characterization of human GluN1/GluN2A heteromeric NMDA receptors that contain SCZ-linked GluN2A variants, and compared them to NMDA receptors with GluN2A variants associated with epilepsy or DD/ID. Our findings demonstrate that SCZ-associated GRIN2A variants were predominantly loss-of-function (LoF), whereas epilepsy and DD/ID-associated variants resulted in both gain- and loss-of-function phenotypes. We additionally show that M653I and S809R, LoF GRIN2A variants associated with DD/ID, exert a dominant-negative effect when co-expressed with a wild-type GluN2A, whereas E58Ter and Y698C, SCZ-linked LoF variants, and A727T, an epilepsy-linked LoF variant, do not. These data offer a potential mechanism by which SCZ/epilepsy and DD/ID-linked variants can cause different effects on receptor function and therefore result in divergent pathological outcomes.
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Affiliation(s)
- Nate Shepard
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sumaiya Iqbal
- The Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Erkin Kurganov
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nikita Budnik
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Arthur J Campbell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jen Q Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Morgan Sheng
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Zohreh Farsi
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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7
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Zhang PP, Benske TM, Ahn LY, Schaffer AE, Paton JC, Paton AW, Mu TW, Wang YJ. Adapting the endoplasmic reticulum proteostasis rescues epilepsy-associated NMDA receptor variants. Acta Pharmacol Sin 2024; 45:282-297. [PMID: 37803141 PMCID: PMC10789767 DOI: 10.1038/s41401-023-01172-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/17/2023] [Indexed: 10/08/2023] Open
Abstract
The GRIN genes encoding N-methyl-D-aspartate receptor (NMDAR) subunits are remarkably intolerant to variation. Many pathogenic NMDAR variants result in their protein misfolding, inefficient assembly, reduced surface expression, and impaired function on neuronal membrane, causing neurological disorders including epilepsy and intellectual disability. Here, we investigated the proteostasis maintenance of NMDARs containing epilepsy-associated variations in the GluN2A subunit, including M705V and A727T. In the transfected HEK293T cells, we showed that the two variants were targeted to the proteasome for degradation and had reduced functional surface expression. We demonstrated that the application of BIX, a known small molecule activator of an HSP70 family chaperone BiP (binding immunoglobulin protein) in the endoplasmic reticulum (ER), dose-dependently enhanced the functional surface expression of the M705V and A727T variants in HEK293T cells. Moreover, BIX (10 μM) increased the surface protein levels of the M705V variant in human iPSC-derived neurons. We revealed that BIX promoted folding, inhibited degradation, and enhanced anterograde trafficking of the M705V variant by modest activation of the IRE1 pathway of the unfolded protein response. Our results suggest that adapting the ER proteostasis network restores the folding, trafficking, and function of pathogenic NMDAR variants, representing a potential treatment for neurological disorders resulting from NMDAR dysfunction.
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Affiliation(s)
- Pei-Pei Zhang
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Taylor M Benske
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Lucie Y Ahn
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Adrienne W Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ting-Wei Mu
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Ya-Juan Wang
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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8
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Allen JP, Garber KB, Perszyk R, Khayat CT, Kell SA, Kaneko M, Quindipan C, Saitta S, Ladda RL, Hewson S, Inbar-Feigenberg M, Prasad C, Prasad AN, Olewiler L, Mu W, Rosenthal LS, Scala M, Striano P, Zara F, McCullock TW, Jauss RT, Lemke JR, MacLean DM, Zhu C, Yuan H, Myers SJ, Traynelis SF. Clinical features, functional consequences, and rescue pharmacology of missense GRID1 and GRID2 human variants. Hum Mol Genet 2024; 33:355-373. [PMID: 37944084 PMCID: PMC10840383 DOI: 10.1093/hmg/ddad188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/28/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023] Open
Abstract
GRID1 and GRID2 encode the enigmatic GluD1 and GluD2 proteins, which form tetrameric receptors that play important roles in synapse organization and development of the central nervous system. Variation in these genes has been implicated in neurodevelopmental phenotypes. We evaluated GRID1 and GRID2 human variants from the literature, ClinVar, and clinical laboratories and found that many of these variants reside in intolerant domains, including the amino terminal domain of both GRID1 and GRID2. Other conserved regions, such as the M3 transmembrane domain, show different intolerance between GRID1 and GRID2. We introduced these variants into GluD1 and GluD2 cDNA and performed electrophysiological and biochemical assays to investigate the mechanisms of dysfunction of GRID1/2 variants. One variant in the GRID1 distal amino terminal domain resides at a position predicted to interact with Cbln2/Cbln4, and the variant disrupts complex formation between GluD1 and Cbln2, which could perturb its role in synapse organization. We also discovered that, like the lurcher mutation (GluD2-A654T), other rare variants in the GRID2 M3 domain create constitutively active receptors that share similar pathogenic phenotypes. We also found that the SCHEMA schizophrenia M3 variant GluD1-A650T produced constitutively active receptors. We tested a variety of compounds for their ability to inhibit constitutive currents of GluD receptor variants and found that pentamidine potently inhibited GluD2-T649A constitutive channels (IC50 50 nM). These results identify regions of intolerance to variation in the GRID genes, illustrate the functional consequences of GRID1 and GRID2 variants, and suggest how these receptors function normally and in disease.
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Affiliation(s)
- James P Allen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Kathryn B Garber
- Department of Human Genetics, Emory University School of Medicine, 615 Michael St., Atlanta GA 30322, United States
- EGL Genetics, 2460 Mountain Industrial Blvd., Tucker, GA 30084, United States
| | - Riley Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Cara T Khayat
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA 30332, United States
| | - Steven A Kell
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Department of Chemistry, Emory University School of Medicine, 1515 Dickey Dr, Atlanta, GA 30322, United States
| | - Maki Kaneko
- Division of Genomic Medicine, Department of Pathology, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
- Center for Personalized Medicine, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
| | - Catherine Quindipan
- Center for Personalized Medicine, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
| | - Sulagna Saitta
- Division of Clinical Genetics, Departments of Human Genetics, OBGYN and Pediatrics, David Geffen School of Medicine at UCLA, 200 Medical Plaza, Los Angeles, CA 90095, United States
| | - Roger L Ladda
- Division of Human Genetics, Department of Pediatrics, Penn State College of Medicine, 600 University Dr, Hershey, PA 17033, United States
| | - Stacy Hewson
- Department of Genetic Counselling, The Hospital for Sick Children and Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5G 1X8, Canada
| | - Michal Inbar-Feigenberg
- Division of Clinical & Metabolic Genetics, The Hospital for Sick Children and Pediatrics, University of Toronto, 555 University Avenue, Toronto ON M5G 1X8, Canada
| | - Chitra Prasad
- Department of Pediatrics (Section of Genetics and Metabolism), Western University and Schulich School of Medicine and Dentistry, Children’s Hospital LHSC, 800 Commissioners Road East, London, ON N6A5W9, Canada
| | - Asuri N Prasad
- Division of Pediatric Neurology, Department of Pediatrics and Clinical Neurological Sciences, Western University and Schulich School of Medicine and Dentistry, Children’s Hospital LHSC, 800 Commissioners Road East, London, ON N6A5W9, Canada
| | - Leah Olewiler
- Department of Pediatrics, Division of Medical Genetics, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216, United States
| | - Weiyi Mu
- Department of Genetic Medicine, Johns Hopkins University, 600 N. Wolfe St., Baltimore MD 21287, United States
| | - Liana S Rosenthal
- Department of Neurology, Johns Hopkins University, 601 N. Caroline St., Baltimore MD 21287, United States
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università Degli Studi di Genova, Largo Paolo Daneo, 3, 16132 Genova GE, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Pavilion 16, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università Degli Studi di Genova, Largo Paolo Daneo, 3, 16132 Genova GE, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Pavilion 16, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Federico Zara
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Pavilion 20, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Tyler W McCullock
- Department Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester NY, 14642, United States
| | - Robin-Tobias Jauss
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Str. 55, Haus W, Leipzig 04103, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Str. 55, Haus W, Leipzig 04103, Germany
| | - David M MacLean
- Department Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester NY, 14642, United States
| | - Cheng Zhu
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA 30332, United States
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Emory Neurodegenerative Disease Center, 615 Michael St., Emory University School of Medicine, Atlanta, GA 30322, United States
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9
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Yi F, Traynelis SF, Hansen KB. Selective Cell-Surface Expression of Triheteromeric NMDA Receptors. Methods Mol Biol 2024; 2799:55-77. [PMID: 38727903 PMCID: PMC11311247 DOI: 10.1007/978-1-0716-3830-9_5] [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] [Indexed: 06/01/2024]
Abstract
NMDA-type ionotropic glutamate receptors are critically involved in many brain functions and are implicated in a variety of brain disorders. Seven NMDA receptor subunits exist (GluN1, GluN2A-D, and GluN3A-B) that assemble into tetrameric receptor subtypes with distinct functional properties and physiological roles. The majority NMDA receptors are composed of two GluN1 and two GluN2 subunits, which can assemble into four diheteromeric receptors subtypes composed of GluN1 and one type of GluN2 subunit (e.g., GluN1/2A), and presumably also six triheteromeric receptor subtypes composed of GluN1 and two different GluN2 subunits (e.g., GluN1/2A/2B). Furthermore, the GluN1 subunit exists as eight splice variants (e.g., GluN1-1a and GluN1-1b isoforms), and two different GluN1 isoforms can co-assemble to also form triheteromeric NMDA receptors (e.g., GluN1-1a/1b/2A). Here, we describe a method to faithfully express triheteromeric NMDA receptors in heterologous expression systems by controlling the identity of two of the four subunits. This method overcomes the problem that co-expression of three different NMDA receptor subunits generates two distinct diheteromeric receptor subtypes as well as one triheteromeric receptor subtype, thereby confounding studies that require a homogenous population of triheteromeric NMDA receptors. The method has been applied to selectively express recombinant triheteromeric GluN1/2A/2B, GluN1/2A/2C, GluN1/2B/2D, GluN1-1a/GluN1-1b/2A, GluN1-1a/GluN1-1b/2B receptors with negligible co-expression of the respective diheteromeric receptor subtypes. This method therefore enables quantitative evaluation of functional and pharmacological properties of triheteromeric NMDA receptors, some of which are abundant NMDA receptor subtypes in the adult brain.
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Affiliation(s)
- Feng Yi
- Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Kasper B Hansen
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
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10
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Varlamova EG, Borisova EV, Evstratova YA, Newman AG, Kuldaeva VP, Gavrish MS, Kondakova EV, Tarabykin VS, Babaev AA, Turovsky EA. Socrates: A Novel N-Ethyl-N-nitrosourea-Induced Mouse Mutant with Audiogenic Epilepsy. Int J Mol Sci 2023; 24:17104. [PMID: 38069426 PMCID: PMC10707124 DOI: 10.3390/ijms242317104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Epilepsy is one of the common neurological diseases that affects not only adults but also infants and children. Because epilepsy has been studied for a long time, there are several pharmacologically effective anticonvulsants, which, however, are not suitable as therapy for all patients. The genesis of epilepsy has been extensively investigated in terms of its occurrence after injury and as a concomitant disease with various brain diseases, such as tumors, ischemic events, etc. However, in the last decades, there are multiple reports that both genetic and epigenetic factors play an important role in epileptogenesis. Therefore, there is a need for further identification of genes and loci that can be associated with higher susceptibility to epileptic seizures. Use of mouse knockout models of epileptogenesis is very informative, but it has its limitations. One of them is due to the fact that complete deletion of a gene is not, in many cases, similar to human epilepsy-associated syndromes. Another approach to generating mouse models of epilepsy is N-Ethyl-N-nitrosourea (ENU)-directed mutagenesis. Recently, using this approach, we generated a novel mouse strain, soc (socrates, formerly s8-3), with epileptiform activity. Using molecular biology methods, calcium neuroimaging, and immunocytochemistry, we were able to characterize the strain. Neurons isolated from soc mutant brains retain the ability to differentiate in vitro and form a network. However, soc mutant neurons are characterized by increased spontaneous excitation activity. They also demonstrate a high degree of Ca2+ activity compared to WT neurons. Additionally, they show increased expression of NMDA receptors, decreased expression of the Ca2+-conducting GluA2 subunit of AMPA receptors, suppressed expression of phosphoinositol 3-kinase, and BK channels of the cytoplasmic membrane involved in protection against epileptogenesis. During embryonic and postnatal development, the expression of several genes encoding ion channels is downregulated in vivo, as well. Our data indicate that soc mutation causes a disruption of the excitation-inhibition balance in the brain, and it can serve as a mouse model of epilepsy.
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Affiliation(s)
- Elena G. Varlamova
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia;
| | - Ekaterina V. Borisova
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.V.B.); (A.G.N.)
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
| | - Yuliya A. Evstratova
- Federal State Budgetary Educational Institution of Higher Education “MIREA—Russian Technological University”, 78, Vernadskogo Ave., 119454 Moscow, Russia;
| | - Andrew G. Newman
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.V.B.); (A.G.N.)
| | - Vera P. Kuldaeva
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
- Research Institute of Medical Genetics, Tomsk National Research Medical Center, Russian Academy of Sciences, 10 Nab. Ushaiki, 634050 Tomsk, Russia
| | - Maria S. Gavrish
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
| | - Elena V. Kondakova
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
- Research Institute of Medical Genetics, Tomsk National Research Medical Center, Russian Academy of Sciences, 10 Nab. Ushaiki, 634050 Tomsk, Russia
| | - Victor S. Tarabykin
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; (E.V.B.); (A.G.N.)
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
- Research Institute of Medical Genetics, Tomsk National Research Medical Center, Russian Academy of Sciences, 10 Nab. Ushaiki, 634050 Tomsk, Russia
| | - Alexey A. Babaev
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
| | - Egor A. Turovsky
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia;
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia; (V.P.K.); (M.S.G.); (E.V.K.); (A.A.B.)
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11
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Moody G, Musco A, Bennett J, Wollmuth LP. An integrated approach to evaluate the functional effects of disease-associated NMDA receptor variants. Neuropharmacology 2023; 240:109703. [PMID: 37689262 DOI: 10.1016/j.neuropharm.2023.109703] [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: 04/17/2023] [Revised: 06/30/2023] [Accepted: 08/31/2023] [Indexed: 09/11/2023]
Abstract
The NMDA receptor (NMDAR) is a ubiquitously expressed glutamate-gated ion channel that plays key roles in brain development and function. Not surprisingly, a variety of disease-associated variants have been identified in genes encoding NMDAR subunits. A critical first step to assess whether these variants contribute to their associated disorder is to characterize their effect on receptor function. However, the complexity of NMDAR function makes this challenging, with many variants typically altering multiple functional properties. At synapses, NMDARs encode pre- and postsynaptic activity to carry a charge transfer that alters membrane excitability and a Ca2+ influx that has both short- and long-term signaling actions. Here, we characterized epilepsy-associated variants in GluN1 and GluN2A subunits with various phenotypic severity in HEK293 cells. To capture the complexity of NMDAR gating, we applied 10 glutamate pulses at 10 Hz to derive a charge integral. This assay is advantageous since it incorporates multiple gating parameters - activation, deactivation, and desensitization - into a single value. We then integrated this gating parameter with Mg2+ block and Ca2+ influx using fractional Ca2+ currents to generate indices of charge transfer and Ca2+ transfer over wide voltage ranges. This approach yields consolidated parameters that can be used as a reference to normalize channel block and allosteric modulation to better define potential patient treatment. This is especially true for variants in the transmembrane domain that affect not only receptor gating but also often Mg2+ block and Ca2+ permeation.
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Affiliation(s)
- Gabrielle Moody
- Graduate Program in Molecular & Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794-5230, United States
| | - Angela Musco
- Stony Brook Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, 11794-5230, United States
| | - Joseph Bennett
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, United States
| | - Lonnie P Wollmuth
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, United States; Department of Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY, 11794-5230, United States; Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY, 11794-5230, United States.
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12
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XiangWei W, Perszyk RE, Liu N, Xu Y, Bhattacharya S, Shaulsky GH, Smith-Hicks C, Fatemi A, Fry AE, Chandler K, Wang T, Vogt J, Cohen JS, Paciorkowski AR, Poduri A, Zhang Y, Wang S, Wang Y, Zhai Q, Fang F, Leng J, Garber K, Myers SJ, Jauss RT, Park KL, Benke TA, Lemke JR, Yuan H, Jiang Y, Traynelis SF. Clinical and functional consequences of GRIA variants in patients with neurological diseases. Cell Mol Life Sci 2023; 80:345. [PMID: 37921875 PMCID: PMC10754216 DOI: 10.1007/s00018-023-04991-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 11/05/2023]
Abstract
AMPA receptors are members of the glutamate receptor family and mediate a fast component of excitatory synaptic transmission at virtually all central synapses. Thus, their functional characteristics are a critical determinant of brain function. We evaluate intolerance of each GRIA gene to genetic variation using 3DMTR and report here the functional consequences of 52 missense variants in GRIA1-4 identified in patients with various neurological disorders. These variants produce changes in agonist EC50, response time course, desensitization, and/or receptor surface expression. We predict that these functional and localization changes will have important consequences for circuit function, and therefore likely contribute to the patients' clinical phenotype. We evaluated the sensitivity of variant receptors to AMPAR-selective modulators including FDA-approved drugs to explore potential targeted therapeutic options.
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Affiliation(s)
- Wenshu XiangWei
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Nana Liu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Neurology, The First Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Subhrajit Bhattacharya
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- School of Pharmaceutical and Health Sciences, Keck Graduate Institute, Claremont Colleges, Claremont, CA, 91711, USA
| | - Gil H Shaulsky
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Constance Smith-Hicks
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Ali Fatemi
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Andrew E Fry
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, CF14 4XW, UK
- Division of Cancer and Genetics, Cardiff University, Cardiff, CF14 4XN, UK
| | - Kate Chandler
- Manchester Centre for Genomic Medicine (MCGM), Manchester University NHS Foundation Trust, Saint Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK
| | - Tao Wang
- Department of Pediatrics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Julie Vogt
- West Midlands Regional Genetics Service, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, B4 6NH, UK
| | - Julie S Cohen
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Alex R Paciorkowski
- University of Rochester Medical Center, Child Neurology, 601 Elmwood Ave., Rochester, NY, 14642, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
| | - Yuehua Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Shuang Wang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuping Wang
- Department of Neurology, Center of Epilepsy, Beijing Key Laboratory of Neuromodulation, Institute of Sleep and Consciousness Disorders, Beijing Institute for Brain Disorders, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Qiongxiang Zhai
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Fang Fang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, 100069, China
| | - Jie Leng
- Department Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450066, Henan, China
- Department of Endocrinology, Genetics and Metabolism, School of Medicine, Chengdu Women's and Children's Central Hospital, University of Electronic Science and Technology of China, Sichuan, 611731, China
| | - Kathryn Garber
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Robin-Tobias Jauss
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
| | - Kristen L Park
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - Timothy A Benke
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Yuwu Jiang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China.
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Emory Neurodegenerative Disease Center, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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13
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Farsi Z, Nicolella A, Simmons SK, Aryal S, Shepard N, Brenner K, Lin S, Herzog L, Moran SP, Stalnaker KJ, Shin W, Gazestani V, Song BJ, Bonanno K, Keshishian H, Carr SA, Pan JQ, Macosko EZ, Datta SR, Dejanovic B, Kim E, Levin JZ, Sheng M. Brain-region-specific changes in neurons and glia and dysregulation of dopamine signaling in Grin2a mutant mice. Neuron 2023; 111:3378-3396.e9. [PMID: 37657442 DOI: 10.1016/j.neuron.2023.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 05/19/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
A genetically valid animal model could transform our understanding of schizophrenia (SCZ) disease mechanisms. Rare heterozygous loss-of-function (LoF) mutations in GRIN2A, encoding a subunit of the NMDA receptor, greatly increase the risk of SCZ. By transcriptomic, proteomic, and behavioral analyses, we report that heterozygous Grin2a mutant mice show (1) large-scale gene expression changes across multiple brain regions and in neuronal (excitatory and inhibitory) and non-neuronal cells (astrocytes and oligodendrocytes), (2) evidence of hypoactivity in the prefrontal cortex (PFC) and hyperactivity in the hippocampus and striatum, (3) an elevated dopamine signaling in the striatum and hypersensitivity to amphetamine-induced hyperlocomotion (AIH), (4) altered cholesterol biosynthesis in astrocytes, (5) a reduction in glutamatergic receptor signaling proteins in the synapse, and (6) an aberrant locomotor pattern opposite of that induced by antipsychotic drugs. These findings reveal potential pathophysiologic mechanisms, provide support for both the "hypo-glutamate" and "hyper-dopamine" hypotheses of SCZ, and underscore the utility of Grin2a-deficient mice as a genetic model of SCZ.
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Affiliation(s)
- Zohreh Farsi
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Ally Nicolella
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sean K Simmons
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sameer Aryal
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nate Shepard
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kira Brenner
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sherry Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Linnea Herzog
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sean P Moran
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Katherine J Stalnaker
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Wangyong Shin
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea
| | - Vahid Gazestani
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Bryan J Song
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kevin Bonanno
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hasmik Keshishian
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Steven A Carr
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jen Q Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Evan Z Macosko
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Massachusetts General Hospital, Department of Psychiatry, Boston, MA, USA
| | | | - Borislav Dejanovic
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea; Department of Biological Sciences, Korea Advanced Institute for Science and Technology, Daejeon, South Korea
| | - Joshua Z Levin
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Morgan Sheng
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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14
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Myers SJ, Yuan H, Perszyk RE, Zhang J, Kim S, Nocilla KA, Allen JP, Bain JM, Lemke JR, Lal D, Benke TA, Traynelis SF. Classification of missense variants in the N-methyl-d-aspartate receptor GRIN gene family as gain- or loss-of-function. Hum Mol Genet 2023; 32:2857-2871. [PMID: 37369021 PMCID: PMC10508039 DOI: 10.1093/hmg/ddad104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Advances in sequencing technology have generated a large amount of genetic data from patients with neurological conditions. These data have provided diagnosis of many rare diseases, including a number of pathogenic de novo missense variants in GRIN genes encoding N-methyl-d-aspartate receptors (NMDARs). To understand the ramifications for neurons and brain circuits affected by rare patient variants, functional analysis of the variant receptor is necessary in model systems. For NMDARs, this functional analysis needs to assess multiple properties in order to understand how variants could impact receptor function in neurons. One can then use these data to determine whether the overall actions will increase or decrease NMDAR-mediated charge transfer. Here, we describe an analytical and comprehensive framework by which to categorize GRIN variants as either gain-of-function (GoF) or loss-of-function (LoF) and apply this approach to GRIN2B variants identified in patients and the general population. This framework draws on results from six different assays that assess the impact of the variant on NMDAR sensitivity to agonists and endogenous modulators, trafficking to the plasma membrane, response time course and channel open probability. We propose to integrate data from multiple in vitro assays to arrive at a variant classification, and suggest threshold levels that guide confidence. The data supporting GoF and LoF determination are essential to assessing pathogenicity and patient stratification for clinical trials as personalized pharmacological and genetic agents that can enhance or reduce receptor function are advanced. This approach to functional variant classification can generalize to other disorders associated with missense variants.
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Affiliation(s)
- Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- The Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- The Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jing Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kelsey A Nocilla
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - James P Allen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- The Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jennifer M Bain
- Department of Neurology, Division of Child Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, Köln 50923, Germany
| | - Timothy A Benke
- Department of Pediatrics, Pharmacology and Neurology, University of Colorado School of Medicine, and Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- The Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Neurodegenerative Disease Center, Emory University School of Medicine, Atlanta, GA 30322, USA
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15
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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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16
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Xie L, McDaniel MJ, Perszyk RE, Kim S, Cappuccio G, Shapiro KA, Muñoz-Cabello B, Sanchez-Lara PA, Grand K, Zhang J, Nocilla KA, Sheikh R, Armengol L, Romano R, Pierson TM, Yuan H, Myers SJ, Traynelis SF. Functional effects of disease-associated variants reveal that the S1-M1 linker of the NMDA receptor critically controls channel opening. Cell Mol Life Sci 2023; 80:110. [PMID: 37000222 PMCID: PMC10641759 DOI: 10.1007/s00018-023-04705-y] [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: 11/10/2022] [Revised: 01/12/2023] [Accepted: 01/20/2023] [Indexed: 04/01/2023]
Abstract
The short pre-M1 helix within the S1-M1 linker (also referred to as the pre-M1 linker) between the agonist-binding domain (ABD, S1) and the M1 transmembrane helix of the NMDA receptor (NMDAR) is devoid of missense variants within the healthy population but is a locus for de novo pathogenic variants associated with neurological disorders. Several de novo variants within this helix have been identified in patients presenting early in life with intellectual disability, developmental delay, and/or epilepsy. In this study, we evaluated functional properties for twenty variants within the pre-M1 linker in GRIN1, GRIN2A, and GRIN2B genes, including six novel missense variants. The effects of pre-M1 variants on agonist potency, sensitivity to endogenous allosteric modulators, response time course, channel open probability, and surface expression were assessed. Our data indicated that virtually all of the variants evaluated altered channel function, and multiple variants had profound functional consequences, which may contribute to the neurological conditions in the patients harboring the variants in this region. These data strongly suggest that the residues within the pre-M1 helix play a key role in channel gating and are highly intolerant to genetic variation.
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Affiliation(s)
- Lingling Xie
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
- Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
| | - Miranda J McDaniel
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
| | - Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gerarda Cappuccio
- Section of Pediatrics, Department of Translational Medicine, Federico II University, Via Pansini 5, 80131, Naples, Italy
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Kevin A Shapiro
- Department of Neurology, University of California, UCSF Memory and Aging Center, Sandler Neurosciences Center, San Francisco, CA, USA
| | | | - Pedro A Sanchez-Lara
- Division of Medical Genetics, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, USA
| | - Katheryn Grand
- Division of Medical Genetics, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, USA
| | - Jing Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
| | - Kelsey A Nocilla
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
| | - Rehan Sheikh
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
| | - Lluis Armengol
- Quantitative Genomic Medicine Laboratories, SL (qGenomics), Barcelona, Spain
| | - Roberta Romano
- Section of Pediatrics, Department of Translational Medicine, Federico II University, Via Pansini 5, 80131, Naples, Italy
| | - Tyler Mark Pierson
- Division of Pediatric Neurology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, USA
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, USA
- Center for the Undiagnosed Patient, Cedars-Sinai Medical Center, Los Angeles, USA
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, USA
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Road, NE, Atlanta, GA, 30322, USA.
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Emory Neurodegenerative Disease Center, Atlanta, GA, 30322, USA.
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17
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Pereira-Nunes J, Sousa JM, Fonseca J, Melo C, Alves D, Sampaio M, Sousa R. Successful Treatment of a Child With Epileptic Encephalopathy With Spike-Wave Activation in Sleep and GRIN2A Variant Using Sulthiame. Cureus 2023; 15:e34686. [PMID: 36909045 PMCID: PMC9996194 DOI: 10.7759/cureus.34686] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2023] [Indexed: 02/09/2023] Open
Abstract
Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) and developmental EE-SWAS (DEE-SWAS) are characterized by variable combinations of cognitive, language, behavioral, and/or motor regression associated with continuous or near-continuous diffuse spike-and-wave complexes during sleep. Glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A) variants have been associated with EE-SWAS. It encodes the most relevant GluN2 subunit of the N-methyl-D-aspartate receptor (NMDAR). Sulthiame reduces NMDAR-mediated neuronal excitability and has been progressively used as monotherapy in self-limited epilepsy with centrotemporal spikes (SeLECTS) or as add-ontherapy in EE-SWAS/DEE-SWAS. A five-year-old female, with family history of epilepsy, was initially diagnosed with SeLECTS and medicated with valproic acid (VPA). One year later, she presented a focal to bilateral tonic-clonic seizure during sleep and learning difficulty. The electroencephalogram revealed continuous spike-and-wave during sleep leading to the diagnosis of EE-SWAS. Prednisolone was effective, but there was repeated recurrence after its discontinuation and associated adverse effects. As an alternative, sulthiame was added to VPA. Four years later, she remains clinically stable. Genetic testing revealed a GRIN2A missense variant, C.3228C>A (p.Asn1076Lys). Sulthiame appeared effective in this recurrent EE-SWAS child, who presented a GRIN2A missense variant with possible NMDAR gain-of-function and adverse effects of corticosteroids. Functional studies of GRIN2A variants might become a future tool for individualized therapies.
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Affiliation(s)
- Joana Pereira-Nunes
- Department of Pediatrics, Centro Hospitalar Universitário de São João, Porto, PRT.,Department of Gynecology-Obstetrics and Pediatrics, Faculty of Medicine of Porto University, Porto, PRT
| | - José Maria Sousa
- Department of Neuroradiology, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Jacinta Fonseca
- Pediatric Neurology Unit, Department of Pediatrics, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Cláudia Melo
- Pediatric Neurology Unit, Department of Pediatrics, Centro Hospitalar Universitário de São João, Porto, PRT.,Department of Gynecology-Obstetrics and Pediatrics, Faculty of Medicine of Porto University, Porto, PRT
| | - Dílio Alves
- Department of Neurophysiology, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Mafalda Sampaio
- Pediatric Neurology Unit, Department of Pediatrics, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Raquel Sousa
- Pediatric Neurology Unit, Department of Pediatrics, Centro Hospitalar Universitário de São João, Porto, PRT
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18
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GRIN2A-related epilepsy and speech disorders: A comprehensive overview with a focus on the role of precision therapeutics. Epilepsy Res 2023; 189:107065. [PMID: 36516565 DOI: 10.1016/j.eplepsyres.2022.107065] [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: 08/18/2022] [Revised: 10/27/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Language dysfunction is a common and serious comorbidity of epilepsy, especially in individuals with epilepsy aphasia spectrum syndromes. Childhood epilepsy with centrotemporal spikes is on the mild end of the spectrum, while epileptic encephalopathy with continuous spike-and-wave during sleep syndrome is on the severe end. Traditional antiseizure medicines and immunotherapy are currently used to treat severely affected patients, but the results are usually disappointing. The discovery that GRIN2A is the primary monogenic etiology of these diseases has opened the door to precision treatments. The GRIN2A gene encodes GluN2A protein, which constitutes a subunit of the NMDA receptor (NMDAR). The GRIN2A pathogenic variants cause gain or loss of function of NMDAR; the former can be treated with uncompetitive NMDAR antagonists, such as memantine, while the latter with NMDAR co-agonist serine. Hyper-precision therapies with various other effective agents are likely to be developed shortly to target the diverse functional effects of different variants. Precision treatments for GRIN2A-related disorders will benefit those who suffer from the condition and pave the way for new therapeutic approaches to a variety of other NMDAR-linked neurodegenerative and psychiatric diseases (schizophrenia, Parkinson's disease, Alzheimer's disease, and so on). Furthermore, more research into GRIN2A-related disorders will help us better understand the neuroinflammatory and neuroimmunological basis of epilepsy, as well as the pathological and physiological network activation mechanisms that cause sleep activation of central-temporal spikes and language impairment.
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19
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Iacobucci GJ, Liu B, Wen H, Sincox B, Zheng W, Popescu GK. Complex functional phenotypes of NMDA receptor disease variants. Mol Psychiatry 2022; 27:5113-5123. [PMID: 36117210 DOI: 10.1038/s41380-022-01774-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/23/2022] [Accepted: 08/31/2022] [Indexed: 01/14/2023]
Abstract
NMDA receptors have essential roles in the physiology of central excitatory synapses and their dysfunction causes severe neuropsychiatric symptoms. Recently, a series of genetic variants have been identified in patients, however, functional information about these variants is sparse and their role in pathogenesis insufficiently known. Here we investigate the mechanism by which two GluN2A variants may be pathogenic. We use molecular dynamics simulation and single-molecule electrophysiology to examine the contribution of GluN2A subunit-residues, P552 and F652, and their pathogenic substitutions, P552R and F652V, affect receptor functions. We found that P552 and F652 interact during the receptors' normal activity cycle; the interaction stabilizes receptors in open conformations and is required for a normal electrical response. Engineering shorter side-chains at these positions (P552A and/or F652V) caused a loss of interaction energy and produced receptors with severe gating, conductance, and permeability deficits. In contrast, the P552R side chain resulted in stronger interaction and produced a distinct, yet still drastically abnormal electrical response. These results identify the dynamic contact between P552 and F652 as a critical step in the NMDA receptor activation, and show that both increased and reduced communication through this interaction cause dysfunction. Results show that subtle differences in NMDA receptor primary structure can generate complex phenotypic alterations whose binary classification is too simplistic to serve as a therapeutic guide.
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Affiliation(s)
- Gary J Iacobucci
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
| | - Beiying Liu
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Han Wen
- Department of Physics, College of Arts and Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Brittany Sincox
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Wenjun Zheng
- Department of Physics, College of Arts and Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
| | - Gabriela K Popescu
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
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20
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Al Qahtani X, Multhaupt-Buell T, Sharma N, Dy-Hollins ME. Myoclonus-Dystonia in an Individual with a Mutation in the GRIN2A Gene. JOURNAL OF PEDIATRIC NEUROLOGY 2022. [DOI: 10.1055/s-0042-1756445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
AbstractMutations in the GRIN2A gene are associated with epilepsy-aphasia spectrum disorders and developmental and epileptic encephalopathies. Associations have been linked with disorders, including autism spectrum disorder and Parkinson's disease. Recently, GRIN2A variants have been reported as a cause of movement disorders in individuals without epilepsy, suggesting that movement disorders should be highlighted as a genetic phenotype associated with pathogenic variants in GRIN2A. We present a case of a male with myoclonus dystonia and without epilepsy found on whole-exome sequencing to have a c.1880G > A; p.S627N variant in the GRIN2A gene. Our case contributes to the expanding phenotypic spectrum of GRIN2A-related disorders and highlights another genetic cause of the myoclonus-dystonia phenotype. GRIN2A should be considered a part of the differential diagnosis of myoclonus-dystonia in individuals with developmental delay without epilepsy.
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Affiliation(s)
- Xena Al Qahtani
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Trisha Multhaupt-Buell
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Marisela E. Dy-Hollins
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
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21
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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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22
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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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23
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Willits AB, Grossi V, Glidden NC, Hyams JS, Young EE. Identification of a Pain-Specific Gene Expression Profile for Pediatric Recurrent Abdominal Pain. FRONTIERS IN PAIN RESEARCH 2022; 2:759634. [PMID: 35295473 PMCID: PMC8915586 DOI: 10.3389/fpain.2021.759634] [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: 08/16/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: Functional Abdominal Pain (FAP) and Irritable Bowel Syndrome (IBS) are common recurrent abdominal pain diagnoses with the hallmark, lack of inflammation. To identify a biological signature for IBS/FAP in the colon, this study used genetic profiling to uncover gene expression changes associated with IBS/FAP and abdominal pain. Methods: Patients (8 to 17 years) newly diagnosed with IBS or FAP were enrolled in the study. At diagnostic colonoscopy, three rectal biopsies were collected, and gene expression analysis was performed using a Qiagen PCR Array. Relative fold difference in gene expression for 84 pain-associated genes was calculated using the 2-ΔΔ Cq method compared with pain-free controls. Factors affecting pain burden (Pain Burden Interview; PBI) were analyzed, including age, sex, rectal inflammation, and gene expression. Data were analyzed using multiple stepwise linear regression and 2-tailed t tests (P ≤ 0.05). Results: Of the 22 total patients in the study, 19 were diagnosed with either IBS-Constipation (frequency of 5.26%), IBS-Diarrhea (47.37%), IBS-Mixed (10.53%), or FAP (36.84%). IBS/FAP patients reported significantly higher pain burden at the time of diagnosis compared to pain-free controls (p < 0.001), as well as significantly higher abdominal pain (p = 0.01). Of the 84 genes, expression of GRIN1 (p = 0.02), MAPK3 (p = 0.04), P2X4 (p = 0.04), and PTGES3 (p = 0.02) were all significantly associated with PBI score. Discussion: Abdominal pain associated with IBS/FAP in pediatric patients may be linked to the expression of GRIN1, MAPK3, P2X4, and PTGES3, pointing to potential novel therapeutic targets for management of recurring abdominal pain.
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Affiliation(s)
- Adam B Willits
- Neuroscience Program, KU Medical Center, Kansas City, KS, United States
| | - Victoria Grossi
- Division of Digestive Diseases, Hepatology, and Nutrition, Connecticut Children's Medical Center, Hartford, CT, United States
| | - Nicole C Glidden
- Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Jeffrey S Hyams
- Division of Digestive Diseases, Hepatology, and Nutrition, Connecticut Children's Medical Center, Hartford, CT, United States
| | - Erin E Young
- Neuroscience Program, KU Medical Center, Kansas City, KS, United States.,Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, United States.,Department of Anesthesiology, KU Medical Center, Kansas City, KS, United States
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24
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Elmasri M, Hunter DW, Winchester G, Bates EE, Aziz W, Van Der Does DM, Karachaliou E, Sakimura K, Penn AC. Common synaptic phenotypes arising from diverse mutations in the human NMDA receptor subunit GluN2A. Commun Biol 2022; 5:174. [PMID: 35228668 PMCID: PMC8885697 DOI: 10.1038/s42003-022-03115-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/31/2022] [Indexed: 02/06/2023] Open
Abstract
Dominant mutations in the human gene GRIN2A, encoding NMDA receptor (NMDAR) subunit GluN2A, make a significant and growing contribution to the catalogue of published single-gene epilepsies. Understanding the disease mechanism in these epilepsy patients is complicated by the surprising diversity of effects that the mutations have on NMDARs. Here we have examined the cell-autonomous effect of five GluN2A mutations, 3 loss-of-function and 2 gain-of-function, on evoked NMDAR-mediated synaptic currents (NMDA-EPSCs) in CA1 pyramidal neurons in cultured hippocampal slices. Despite the mutants differing in their functional incorporation at synapses, prolonged NMDA-EPSC current decays (with only marginal changes in charge transfer) were a common effect for both gain- and loss-of-function mutants. Modelling NMDA-EPSCs with mutant properties in a CA1 neuron revealed that the effect of GRIN2A mutations can lead to abnormal temporal integration and spine calcium dynamics during trains of concerted synaptic activity. Investigations beyond establishing the molecular defects of GluN2A mutants are much needed to understand their impact on synaptic transmission. The cell-autonomous effect of five severe loss- or gain-of-function GluN2A (NMDA receptor) mutations is assessed on evoked NMDAR-mediated synaptic currents in CA1 pyramidal neurons in cultured mouse hippocampal slices. Data and modelling suggest that mutant-like NMDA-EPSCs can lead to abnormal temporal summation and spine calcium dynamics.
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Affiliation(s)
- Marwa Elmasri
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Daniel William Hunter
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Giles Winchester
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Ella Emine Bates
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Wajeeha Aziz
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | | | - Eirini Karachaliou
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Andrew Charles Penn
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK.
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25
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Liu XR, Xu XX, Lin SM, Fan CY, Ye TT, Tang B, Shi YW, Su T, Li BM, Yi YH, Luo JH, Liao WP. GRIN2A Variants Associated With Idiopathic Generalized Epilepsies. Front Mol Neurosci 2021; 14:720984. [PMID: 34720871 PMCID: PMC8551482 DOI: 10.3389/fnmol.2021.720984] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/30/2021] [Indexed: 12/16/2022] Open
Abstract
Objective: The objective of this study is to explore the role of GRIN2A gene in idiopathic generalized epilepsies and the potential underlying mechanism for phenotypic variation. Methods: Whole-exome sequencing was performed in a cohort of 88 patients with idiopathic generalized epilepsies. Electro-physiological alterations of the recombinant N-methyl-D-aspartate receptors (NMDARs) containing GluN2A mutants were examined using two-electrode voltage-clamp recordings. The alterations of protein expression were detected by immunofluorescence staining and biotinylation. Previous studies reported that epilepsy related GRIN2A missense mutations were reviewed. The correlation among phenotypes, functional alterations, and molecular locations was analyzed. Results: Three novel heterozygous missense GRIN2A mutations (c.1770A > C/p.K590N, c.2636A > G/p.K879R, and c.3199C > T/p.R1067W) were identified in three unrelated cases. Electrophysiological analysis demonstrated R1067W significantly increased the current density of GluN1/GluN2A NMDARs. Immunofluorescence staining indicated GluN2A mutants had abundant distribution in the membrane and cytoplasm. Western blotting showed the ratios of surface and total expression of the three GluN2A-mutants were significantly increased comparing to the wild type. Further analysis on the reported missense mutations demonstrated that mutations with severe gain-of-function were associated with epileptic encephalopathy, while mutations with mild gain of function were associated with mild phenotypes, suggesting a quantitative correlation between gain-of-function and phenotypic severity. The mutations located around transmembrane domains were more frequently associated with severe phenotypes and absence seizure-related mutations were mostly located in carboxyl-terminal domain, suggesting molecular sub-regional effects. Significance: This study revealed GRIN2A gene was potentially a candidate pathogenic gene of idiopathic generalized epilepsies. The functional quantitative correlation and the molecular sub-regional implication of mutations helped in explaining the relatively mild clinical phenotypes and incomplete penetrance associated with GRIN2A variants.
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Affiliation(s)
- Xiao-Rong Liu
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xing-Xing Xu
- Department of Physiology, Wenzhou Medical University, Wenzhou, China
| | - Si-Mei Lin
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Cui-Ying Fan
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Ting-Ting Ye
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bin Tang
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yi-Wu Shi
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Tao Su
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bing-Mei Li
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jian-Hong Luo
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei-Ping Liao
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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26
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Mota A, Waxman HK, Hong R, Lagani GD, Niu SY, Bertherat FL, Wolfe L, Malicdan CM, Markello TC, Adams DR, Gahl WA, Cheng CS, Beffert U, Ho A. FOXR1 regulates stress response pathways and is necessary for proper brain development. PLoS Genet 2021; 17:e1009854. [PMID: 34723967 PMCID: PMC8559929 DOI: 10.1371/journal.pgen.1009854] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/01/2021] [Indexed: 11/20/2022] Open
Abstract
The forkhead box (Fox) family of transcription factors are highly conserved and play essential roles in a wide range of cellular and developmental processes. We report an individual with severe neurological symptoms including postnatal microcephaly, progressive brain atrophy and global developmental delay associated with a de novo missense variant (M280L) in the FOXR1 gene. At the protein level, M280L impaired FOXR1 expression and induced a nuclear aggregate phenotype due to protein misfolding and proteolysis. RNAseq and pathway analysis showed that FOXR1 acts as a transcriptional activator and repressor with central roles in heat shock response, chaperone cofactor-dependent protein refolding and cellular response to stress pathways. Indeed, FOXR1 expression is increased in response to cellular stress, a process in which it directly controls HSPA6, HSPA1A and DHRS2 transcripts. The M280L mutant compromises FOXR1's ability to respond to stress, in part due to impaired regulation of downstream target genes that are involved in the stress response pathway. Quantitative PCR of mouse embryo tissues show Foxr1 expression in the embryonic brain. Using CRISPR/Cas9 gene editing, we found that deletion of mouse Foxr1 leads to a severe survival deficit while surviving newborn Foxr1 knockout mice have reduced body weight. Further examination of newborn Foxr1 knockout brains revealed a decrease in cortical thickness and enlarged ventricles compared to littermate wild-type mice, suggesting that loss of Foxr1 leads to atypical brain development. Combined, these results suggest FOXR1 plays a role in cellular stress response pathways and is necessary for normal brain development.
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Affiliation(s)
- Andressa Mota
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Hannah K. Waxman
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Rui Hong
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
| | - Gavin D. Lagani
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Sheng-Yong Niu
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Féodora L. Bertherat
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Lynne Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christine May Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thomas C. Markello
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David R. Adams
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - William A. Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christine S. Cheng
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
| | - Uwe Beffert
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Angela Ho
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
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27
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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: 258] [Impact Index Per Article: 86.0] [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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29
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Perszyk RE, Kristensen AS, Lyuboslavsky P, Traynelis SF. Three-dimensional missense tolerance ratio analysis. Genome Res 2021; 31:1447-1461. [PMID: 34301626 PMCID: PMC8327912 DOI: 10.1101/gr.275528.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/15/2021] [Indexed: 12/11/2022]
Abstract
A wealth of genetic information is available describing single-nucleotide variants in the human population that appear to be well-tolerated and in and of themselves do not confer disease. These variant data sets contain signatures about the protein structure-function relationships and provide an unbiased view of various protein functions in the context of human health. This information can be used to determine regional intolerance to variation, defined as the missense tolerance ratio (MTR), which is an indicator of stretches of the polypeptide chain that can tolerate changes without compromising protein function in a manner that impacts human health. This approach circumvents the lack of comprehensive data by averaging the data from adjacent residues on the polypeptide chain. We reasoned that many motifs in proteins consist of nonadjacent residues, but together function as a unit. We therefore developed an approach to analyze nearest neighbors in three-dimensional space as determined by crystallography rather than on the polypeptide chain. We used members of the GRIN gene family that encode subunits of NMDA-type ionotropic glutamate receptors (iGluRs) to exemplify the differences between these methods. Our method, 3DMTR, provides new information about regions of intolerance within iGluRs, allows consideration of protein-protein interfaces in multimeric proteins, and moves this important research tool from one-dimensional analysis to a structurally relevant tool. We validate the improved 3DMTR score by showing that it more accurately classifies the functional consequences of a set of newly measured and published point mutations of Grin family genes than existing methods.
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Affiliation(s)
- Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | - Anders S Kristensen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | - Polina Lyuboslavsky
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, Georgia 30322, USA
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30
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Drees M, Kulkarni N, Vidaurre J. Electrical Status Epilepticus during Sleep and Evaluating the Electroencephalogram. JOURNAL OF PEDIATRIC EPILEPSY 2021. [DOI: 10.1055/s-0041-1731412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractElectrical status epilepticus during sleep (ESES) is an age-related, self-limited epileptic encephalopathy characterized by heterogeneous clinical manifestations and a specific electroencephalographic pattern of continuous spikes and waves during slow sleep. The etiology of ESES is not completely clear, although structural brain lesions, abnormal immunological markers, and genetic mutations have been associated with the syndrome. ESES was first described in 1971 and since then, the diagnostic criteria have changed multiple times. Additionally, inconsistency between authors in how to record and evaluate the electroencephalogram also leads to variability between studies. These inconsistencies hamper objectivity, comparison, and generalization. Because of this, one of the first priorities of physicians treating this condition should be defining the parameters of this disease so that cooperative building can occur.
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Affiliation(s)
- Michael Drees
- Department of Pediatric Neurology, Nationwide Children's Hospital, Tipp City, Ohio, United States
| | - Neil Kulkarni
- Department of Pediatric Neurology, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, United States
| | - Jorge Vidaurre
- Department of Pediatric Neurology, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, United States
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31
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Mota Vieira M, Nguyen TA, Wu K, Badger JD, Collins BM, Anggono V, Lu W, Roche KW. An Epilepsy-Associated GRIN2A Rare Variant Disrupts CaMKIIα Phosphorylation of GluN2A and NMDA Receptor Trafficking. Cell Rep 2021; 32:108104. [PMID: 32877683 DOI: 10.1016/j.celrep.2020.108104] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/07/2020] [Accepted: 08/11/2020] [Indexed: 10/23/2022] Open
Abstract
Rare variants in GRIN genes, which encode NMDAR subunits, are strongly associated with neurodevelopmental disorders. Among these, GRIN2A, which encodes the GluN2A subunit of NMDARs, is widely accepted as an epilepsy-causative gene. Here, we functionally characterize the de novo GluN2A-S1459G mutation identified in an epilepsy patient. We show that S1459 is a CaMKIIα phosphorylation site, and that endogenous phosphorylation is regulated during development and in response to synaptic activity in a dark rearing model. GluN2A-S1459 phosphorylation results in preferential binding of NMDARs to SNX27 and a corresponding decrease in PSD-95 binding, which consequently regulates NMDAR trafficking. Furthermore, the epilepsy-associated GluN2A-S1459G variant displays defects in interactions with both SNX27 and PSD-95, resulting in trafficking deficits, reduced spine density, and decreased excitatory synaptic transmission. These data demonstrate a role for CaMKIIα phosphorylation of GluN2A in receptor targeting and implicate NMDAR trafficking defects as a link to epilepsy.
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Affiliation(s)
- Marta Mota Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Thien A Nguyen
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Kunwei Wu
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda, MD 20892, USA
| | - John D Badger
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Brett M Collins
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia
| | - Wei Lu
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD 20892, USA.
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32
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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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33
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Acutain MF, Griebler Luft J, Vazquez CA, Popik B, Cercato MC, Epstein A, Salvetti A, Jerusalinsky DA, de Oliveira Alvares L, Baez MV. Reduced Expression of Hippocampal GluN2A-NMDAR Increases Seizure Susceptibility and Causes Deficits in Contextual Memory. Front Neurosci 2021; 15:644100. [PMID: 33897358 PMCID: PMC8064689 DOI: 10.3389/fnins.2021.644100] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/08/2021] [Indexed: 12/23/2022] Open
Abstract
N-methyl-D-aspartate receptors are heterotetramers composed of two GluN1 obligatory subunits and two regulatory subunits. In cognitive-related brain structures, GluN2A and GluN2B are the most abundant regulatory subunits, and their expression is subjected to tight regulation. During development, GluN2B expression is characteristic of immature synapses, whereas GluN2A is present in mature ones. This change in expression induces a shift in GluN2A/GluN2B ratio known as developmental switch. Moreover, modifications in this relationship have been associated with learning and memory, as well as different pathologies. In this work, we used a specific shRNA to induce a reduction in GluN2A expression after the developmental switch, both in vitro in primary cultured hippocampal neurons and in vivo in adult male Wistar rats. After in vitro characterization, we performed a cognitive profile and evaluated seizure susceptibility in vivo. Our in vitro results showed that the decrease in the expression of GluN2A changes GluN2A/GluN2B ratio without altering the expression of other regulatory subunits. Moreover, rats expressing the anti-GluN2A shRNA in vivo displayed an impaired contextual fear-conditioning memory. In addition, these animals showed increased seizure susceptibility, in terms of both time and intensity, which led us to conclude that deregulation in GluN2A expression at the hippocampus is associated with seizure susceptibility and learning–memory mechanisms.
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Affiliation(s)
- Maria Florencia Acutain
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN, CONICET-UBA), Buenos Aires, Argentina
| | - Jordana Griebler Luft
- Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cecila Alejandra Vazquez
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN, CONICET-UBA), Buenos Aires, Argentina
| | - Bruno Popik
- Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Magalí C Cercato
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN, CONICET-UBA), Buenos Aires, Argentina
| | | | - Anna Salvetti
- International Center for Infectiology Research (CIRI), INSERM U1111, CNRS UMR5308, Université de Lyon (UCBL1), Lyon, France
| | - Diana A Jerusalinsky
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN, CONICET-UBA), Buenos Aires, Argentina
| | | | - Maria Verónica Baez
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN, CONICET-UBA), Buenos Aires, Argentina.,1° U.A. Departamento de Histologia, Embriología, Biologia Celular y Genética, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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34
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Hanson JE, Ma K, Elstrott J, Weber M, Saillet S, Khan AS, Simms J, Liu B, Kim TA, Yu GQ, Chen Y, Wang TM, Jiang Z, Liederer BM, Deshmukh G, Solanoy H, Chan C, Sellers BD, Volgraf M, Schwarz JB, Hackos DH, Weimer RM, Sheng M, Gill TM, Scearce-Levie K, Palop JJ. GluN2A NMDA Receptor Enhancement Improves Brain Oscillations, Synchrony, and Cognitive Functions in Dravet Syndrome and Alzheimer's Disease Models. Cell Rep 2021; 30:381-396.e4. [PMID: 31940483 PMCID: PMC7017907 DOI: 10.1016/j.celrep.2019.12.030] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/11/2019] [Accepted: 12/06/2019] [Indexed: 01/28/2023] Open
Abstract
NMDA receptors (NMDARs) play subunit-specific roles in synaptic function and are implicated in neuropsychiatric and neurodegenerative disorders. However, the in vivo consequences and therapeutic potential of pharmacologically enhancing NMDAR function via allosteric modulation are largely un-known. We examine the in vivo effects of GNE-0723, a positive allosteric modulator of GluN2A-subunit-containing NMDARs, on brain network and cognitive functions in mouse models of Dravet syndrome (DS) and Alzheimer’s disease (AD). GNE-0723 use dependently potentiates synaptic NMDA receptor currents and reduces brain oscillation power with a predominant effect on low-frequency (12–20 Hz) oscillations. Interestingly, DS and AD mouse models display aberrant low-frequency oscillatory power that is tightly correlated with network hypersynchrony. GNE-0723 treatment reduces aberrant low-frequency oscillations and epileptiform discharges and improves cognitive functions in DS and AD mouse models. GluN2A-subunit-containing NMDAR enhancers may have therapeutic benefits in brain disorders with network hypersynchrony and cognitive impairments. Hanson et al. examine the therapeutic effects of enhancing GluN2A-subunit-containing NMDAR function in Dravet syndrome and Alzheimer’s disease mice. GNE-0723 treatment reduces aberrant low-frequency oscillations and epileptiform discharges and improves cognitive functions in both disease models. GluN2A NMDAR enhancers may benefit brain disorders with network hypersynchrony and cognitive impairments.
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Affiliation(s)
- Jesse E Hanson
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA.
| | - Keran Ma
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Justin Elstrott
- Department of Biomedical Imaging, Genentech Inc., South San Francisco, CA 94080, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Sandrine Saillet
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Abdullah S Khan
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Jeffrey Simms
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Benjamin Liu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Thomas A Kim
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Yelin Chen
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Tzu-Ming Wang
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Zhiyu Jiang
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Bianca M Liederer
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, CA 94080, USA
| | - Gauri Deshmukh
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, CA 94080, USA
| | - Hilda Solanoy
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Connie Chan
- Department of Pharmaceuticals, Genentech Inc., South San Francisco, CA 94080, USA
| | - Benjamin D Sellers
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - Matthew Volgraf
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - Jacob B Schwarz
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - David H Hackos
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Robby M Weimer
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA; Department of Biomedical Imaging, Genentech Inc., South San Francisco, CA 94080, USA
| | - Morgan Sheng
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - T Michael Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | | | - Jorge J Palop
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
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35
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Amin JB, Gochman A, He M, Certain N, Wollmuth LP. NMDA Receptors Require Multiple Pre-opening Gating Steps for Efficient Synaptic Activity. Neuron 2020; 109:488-501.e4. [PMID: 33264592 DOI: 10.1016/j.neuron.2020.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/06/2020] [Accepted: 11/11/2020] [Indexed: 12/27/2022]
Abstract
NMDA receptors (NMDARs) are glutamate-gated ion channels that mediate fast excitatory synaptic transmission in the nervous system. Applying glutamate to outside-out patches containing a single NMDAR, we find that agonist-bound receptors transition to the open state via two conformations, an "unconstrained pre-active" state that contributes to fast synaptic events and a "constrained pre-active" state that does not. To define how glutamate drives these conformations, we decoupled the ligand-binding domains from specific transmembrane segments for GluN1 and GluN2A. Displacements of the pore-forming M3 segments define the energy of fast opening. However, to enter the unconstrained conformation and contribute to fast signaling, the GluN2 pre-M1 helix must be displaced before the M3 segments move. This pre-M1 displacement is facilitated by the flexibility of the S2-M4 of GluN1 and GluN2A. Thus, outer structures-pre-M1 and S2-M4-work in concert to remove constraints and prime the channel for rapid opening, facilitating fast synaptic transmission.
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Affiliation(s)
- Johansen B Amin
- Graduate Program in Molecular & Cellular Pharmacology, Stony Brook University, Stony Brook, NY 11794-5230, USA; Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - Aaron Gochman
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - Miaomiao He
- Graduate Program in Biochemistry & Structural Biology, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - Noele Certain
- Graduate Program in Molecular & Cellular Pharmacology, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - Lonnie P Wollmuth
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA; Department of Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY 11794-5230, USA; Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794-5230, USA.
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36
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Loviscach L, Backes TM, Langfermann DS, Ulrich M, Thiel G. Zn 2+ ions inhibit gene transcription following stimulation of the Ca 2+ channels Ca v1.2 and TRPM3. Metallomics 2020; 12:1735-1747. [PMID: 33030499 DOI: 10.1039/d0mt00180e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Zinc, a trace element, is necessary for the correct structure and function of many proteins. Therefore, Zn2+ has to be taken up by the cells, using specific Zn2+ transporters or Ca2+ channels. In this study, we have focused on two Ca2+ channels, the L-type voltage-gated Cav1.2 channel and the transient receptor potential channel TRPM3. Stimulation of either channel induces an intracellular signaling cascade leading to the activation of the transcription factor AP-1. The influx of Ca2+ ions into the cytoplasm is essential for this activity. We asked whether extracellular Zn2+ ions affect Cav1.2 or TRPM3-induced gene transcription following stimulation of the channels. The results show that extracellular Zn2+ ions reduced the activation of AP-1 by more than 80% following stimulation of either voltage-gated Cav1.2 channels or TRPM3 channels. Experiments performed with cells maintained in Ca2+-free medium revealed that Zn2+ ions cannot replace Ca2+ ions in inducing gene transcription via stimulation of Cav1.2 and TRPM3 channels. Re-addition of Ca2+ ions to the cell culture medium, however, restored the ability of these Ca2+ channels to induce a signaling cascade leading to the activation of AP-1. Secretory cells, including neurons and pancreatic β-cells, release Zn2+ ions during exocytosis. We propose that the released Zn2+ ions function as a negative feedback loop for stimulus-induced exocytosis by inhibiting Ca2+ channel signaling.
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Affiliation(s)
- Louisa Loviscach
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany.
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37
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Sarigecili E, Direk MC, Komur M, Bozdogan ST, Okuyaz C. Identification of a Novel Mutation in GRIN2A Gene with Global Developmental Delay and Refractory Epilepsy. Ann Indian Acad Neurol 2020; 23:696-699. [PMID: 33623275 PMCID: PMC7887506 DOI: 10.4103/aian.aian_365_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 10/03/2018] [Indexed: 11/04/2022] Open
Abstract
We report a 2.5-year-old Turkish boy who first presented with nystagmus, lack of eye contact, and hypotonia at 2 months of age and developed refractory seizures when 6 months old. Extensive metabolic tests and imaging being noncontributory, whole-exome sequencing was carried out which revealed a heterozygote NM_001134407.2:C.3299A>G (p.Glu1100Gly) novel mutation in GRIN2A gene. Topiramate was started and seizures were rapidly brought under control. GRIN2A mutations may result in altered GluN2A membrane trafficking and response to glutamate. This report illustrates the clinical variability of GRIN2A mutations according to the age of onset of symptoms and suggests considering mutations in this gene in cases of global developmental delay, refractory epilepsy, and nystagmus.
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Affiliation(s)
- Esra Sarigecili
- Department of Pediatric Neurology, Faculty of Medicine, Mersin University, Mersin, Turkey
| | | | - Mustafa Komur
- Department of Pediatric Neurology, Faculty of Medicine, Mersin University, Mersin, Turkey
| | - Sevcan Tug Bozdogan
- Department of Medical Genetics, Faculty of Medicine, Çukurova University, Adana, Turkey
| | - Cetin Okuyaz
- Department of Pediatric Neurology, Faculty of Medicine, Mersin University, Mersin, Turkey
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38
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Tang W, Liu D, Traynelis SF, Yuan H. Positive allosteric modulators that target NMDA receptors rectify loss-of-function GRIN variants associated with neurological and neuropsychiatric disorders. Neuropharmacology 2020; 177:108247. [PMID: 32712275 DOI: 10.1016/j.neuropharm.2020.108247] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/20/2020] [Accepted: 07/20/2020] [Indexed: 12/23/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) mediate a slow component of excitatory synaptic transmission that plays important roles in normal brain function and development. A large number of disease-associated variants in the GRIN gene family encoding NMDAR GluN subunits have been identified in patients with various neurological and neuropsychiatric disorders. Many of these variants reduce the function of NMDARs by a range of different mechanisms, including reduced glutamate potency, reduced glycine potency, accelerated deactivation time course, decreased surface expression, and/or reduced open probability. We have evaluated whether three positive allosteric modulators of NMDAR receptor function (24(S)-hydroxycholesterol, pregnenolone sulfate, tobramycin) and three co-agonists (d-serine, l-serine, and d-cycloserine) can mitigate the diminished function of NMDARs harboring GRIN variants. We examined the effects of these modulators on NMDARs that contained 21 different loss-of-function variants in GRIN1, GRIN2A, or GRIN2B, identified in patients with epilepsy, intellectual disability, autism, and/or movement disorders. For all variants, some aspect of the reduced function was partially restored. Moreover, some variants showed enhanced sensitivity to positive allosteric modulators compared to wild type receptors. These results raise the possibility that enhancement of NMDAR function by positive allosteric modulators may be a useful therapeutic strategy.
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Affiliation(s)
- Weiting Tang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ding Liu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, 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
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, 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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Amador A, Bostick CD, Olson H, Peters J, Camp CR, Krizay D, Chen W, Han W, Tang W, Kanber A, Kim S, Teoh J, Sah M, Petri S, Paek H, Kim A, Lutz CM, Yang M, Myers SJ, Bhattacharya S, Yuan H, Goldstein DB, Poduri A, Boland MJ, Traynelis SF, Frankel WN. Modelling and treating GRIN2A developmental and epileptic encephalopathy in mice. Brain 2020; 143:2039-2057. [PMID: 32577763 PMCID: PMC7363493 DOI: 10.1093/brain/awaa147] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 03/06/2020] [Accepted: 03/25/2020] [Indexed: 12/14/2022] Open
Abstract
NMDA receptors play crucial roles in excitatory synaptic transmission. Rare variants in GRIN2A encoding the GluN2A subunit are associated with a spectrum of disorders, ranging from mild speech and language delay to intractable neurodevelopmental disorders, including but not limited to developmental and epileptic encephalopathy. A de novo missense variant, p.Ser644Gly, was identified in a child with this disorder, and Grin2a knock-in mice were generated to model and extend understanding of this intractable childhood disease. Homozygous and heterozygous mutant mice exhibited altered hippocampal morphology at 2 weeks of age, and all homozygotes exhibited lethal tonic-clonic seizures by mid-third week. Heterozygous adults displayed susceptibility to induced generalized seizures, hyperactivity, repetitive and reduced anxiety behaviours, plus several unexpected features, including significant resistance to electrically-induced limbic seizures and to pentylenetetrazole induced tonic-clonic seizures. Multielectrode recordings of neuronal networks revealed hyperexcitability and altered bursting and synchronicity. In heterologous cells, mutant receptors had enhanced NMDA receptor agonist potency and slow deactivation following rapid removal of glutamate, as occurs at synapses. NMDA receptor-mediated synaptic currents in heterozygous hippocampal slices also showed a prolonged deactivation time course. Standard anti-epileptic drug monotherapy was ineffective in the patient. Introduction of NMDA receptor antagonists was correlated with a decrease in seizure burden. Chronic treatment of homozygous mouse pups with NMDA receptor antagonists significantly delayed the onset of lethal seizures but did not prevent them. These studies illustrate the power of using multiple experimental modalities to model and test therapies for severe neurodevelopmental disorders, while revealing significant biological complexities associated with GRIN2A developmental and epileptic encephalopathy.
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Affiliation(s)
- Ariadna Amador
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | | | - Heather Olson
- Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Jurrian Peters
- Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Chad R Camp
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
| | - Daniel Krizay
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Genetics and Development, Columbia University, New York, NY, USA
| | - Wenjuan Chen
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Wei Han
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, 400014, China
| | - Weiting Tang
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Ayla Kanber
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
| | - JiaJie Teoh
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Megha Sah
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Sabrina Petri
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Hunki Paek
- Department of Otolaryngology and Head and Neck Surgery, Columbia University, New York, NY, USA
| | - Ana Kim
- Department of Otolaryngology and Head and Neck Surgery, Columbia University, New York, NY, USA
| | - Cathleen M Lutz
- Department of Otolaryngology and Head and Neck Surgery, Columbia University, New York, NY, USA
| | - Mu Yang
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | | | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Genetics and Development, Columbia University, New York, NY, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Michael J Boland
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Genetics and Development, Columbia University, New York, NY, USA
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Pang K, Wang L, Wang W, Zhou J, Cheng C, Han K, Zoghbi HY, Liu Z. Coexpression enrichment analysis at the single-cell level reveals convergent defects in neural progenitor cells and their cell-type transitions in neurodevelopmental disorders. Genome Res 2020; 30:835-848. [PMID: 32554779 PMCID: PMC7370880 DOI: 10.1101/gr.254987.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 06/11/2020] [Indexed: 12/31/2022]
Abstract
A large number of genes have been implicated in neurodevelopmental disorders (NDDs), but their contributions to NDD pathology are difficult to decipher without understanding their diverse roles in different brain cell types. Here, we integrated NDD genetics with single-cell RNA sequencing data to assess coexpression enrichment patterns of various NDD gene sets. We identified midfetal cortical neural progenitor cell development—more specifically, the ventricular radial glia-to-intermediate progenitor cell transition at gestational week 10—as a key point of convergence in autism spectrum disorder (ASD) and epilepsy. Integrated Gene Ontology–based analysis further revealed that ASD genes activate neural differentiation and inhibit cell cycle during the transition, whereas epilepsy genes function as downstream effectors in the same processes, offering one possible explanation for the high comorbidity rate of the two disorders. This approach provides a framework for investigating the cell-type-specific pathophysiology of NDDs.
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Affiliation(s)
- Kaifang Pang
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Computational and Integrative Biomedical Research Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Li Wang
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.,Department of Neurology, University of California, San Francisco, San Francisco, California 94143, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California 94143, USA
| | - Wei Wang
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jian Zhou
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Chao Cheng
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.,Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Kihoon Han
- Department of Neuroscience, College of Medicine, Korea University, Seoul 02841, South Korea
| | - Huda Y Zoghbi
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhandong Liu
- Department of Pediatrics-Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030, USA.,Computational and Integrative Biomedical Research Center, Baylor College of Medicine, Houston, Texas 77030, USA
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41
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Perszyk RE, Myers SJ, Yuan H, Gibb AJ, Furukawa H, Sobolevsky AI, Traynelis SF. Hodgkin-Huxley-Katz Prize Lecture: Genetic and pharmacological control of glutamate receptor channel through a highly conserved gating motif. J Physiol 2020; 598:3071-3083. [PMID: 32468591 DOI: 10.1113/jp278086] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/18/2020] [Indexed: 12/15/2022] Open
Abstract
Glutamate receptors are essential ligand-gated ion channels in the central nervous system that mediate excitatory synaptic transmission in response to the release of glutamate from presynaptic terminals. The structural and biophysical basis underlying the function of these receptors has been studied for decades by a wide range of approaches. However recent structural, pharmacological and genetic studies have provided new insight into the regions of this protein that are critical determinants of receptor function. Lack of variation in specific areas of the protein amino acid sequences in the human population has defined three regions in each receptor subunit that are under selective pressure, which has focused research efforts and driven new hypotheses. In addition, these three closely positioned elements reside near a cavity that is shown by multiple studies to be a likely site of action for allosteric modulators, one of which is currently in use as an FDA-approved anticonvulsant. These structural elements are capable of controlling gating of the pore, and appear to permit some modulators bound within the cavity to also alter permeation properties. This creates a new precedent whereby features of the channel pore can be modulated by exogenous drugs that bind outside the pore. The convergence of structural, genetic, biophysical and pharmacological approaches is a powerful means to gain insight into the complex biological processes defined by neurotransmitter receptor function.
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Affiliation(s)
- Riley E Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, 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
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, 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
| | - Alasdair J Gibb
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Hiro Furukawa
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, 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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42
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Chow CY, Absalom N, Biggs K, King GF, Ma L. Venom-derived modulators of epilepsy-related ion channels. Biochem Pharmacol 2020; 181:114043. [PMID: 32445870 DOI: 10.1016/j.bcp.2020.114043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Epilepsy is characterised by spontaneous recurrent seizures that are caused by an imbalance between neuronal excitability and inhibition. Since ion channels play fundamental roles in the generation and propagation of action potentials as well as neurotransmitter release at a subset of excitatory and inhibitory synapses, their dysfunction has been linked to a wide variety of epilepsies. Indeed, these unique proteins are the major biological targets for antiepileptic drugs. Selective targeting of a specific ion channel subtype remains challenging for small molecules, due to the high level of homology among members of the same channel family. As a consequence, there is a growing trend to target ion channels with biologics. Venoms are the best known natural source of ion channel modulators, and venom peptides are increasingly recognised as potential therapeutics due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Here we describe the major ion channel families involved in the pathogenesis of various types of epilepsy, including voltage-gated Na+, K+, Ca2+ channels, Cys-loop receptors, ionotropic glutamate receptors and P2X receptors, and currently available venom-derived peptides that target these channel proteins. Although only a small number of venom peptides have successfully progressed to the clinic, there is reason to be optimistic about their development as antiepileptic drugs, notwithstanding the challenges associated with development of any class of peptide drug.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nathan Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kimberley Biggs
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia.
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43
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Amin JB, Moody GR, Wollmuth LP. From bedside-to-bench: What disease-associated variants are teaching us about the NMDA receptor. J Physiol 2020; 599:397-416. [PMID: 32144935 DOI: 10.1113/jp278705] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/21/2020] [Indexed: 12/25/2022] Open
Abstract
NMDA receptors (NMDARs) are glutamate-gated ion channels that contribute to nearly all brain processes. Not surprisingly then, genetic variations in the genes encoding NMDAR subunits can be associated with neurodevelopmental, neurological and psychiatric disorders. These disease-associated variants (DAVs) present challenges, such as defining how DAV-induced alterations in receptor function contribute to disease progression and how to treat the affected individual clinically. As a starting point to overcome these challenges, we need to refine our understanding of the complexity of NMDAR structure function. In this regard, DAVs have expanded our knowledge of NMDARs because they do not just target well-known structure-function motifs, but rather give an unbiased view of structural elements that are important to the biology of NMDARs. Indeed, established NMDAR structure-function motifs have been validated by the appearance of disorders in patients where these motifs have been altered, and DAVs have identified novel structural features in NMDARs such as gating triads and hinges in the gating machinery. Still, the majority of DAVs remain unexplored and occur at sites in the protein with unidentified function or alter receptor properties in multiple and unanticipated ways. Detailed mechanistic and structural investigations are required of both established and novel motifs to develop a highly refined pathomechanistic model that accounts for the complex machinery that regulates NMDARs. Such a model would provide a template for rational drug design and a starting point for personalized medicine.
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Affiliation(s)
- Johansen B Amin
- Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY, 11794-5230.,Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794-5230
| | - Gabrielle R Moody
- Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794-5230
| | - Lonnie P Wollmuth
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, 11794-5230.,Department of Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY, 11794-5230.,Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY, 11794-5230
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44
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Lee S, Kim SH, Kim B, Lee ST, Choi JR, Kim HD, Lee JS, Kang HC. Genetic diagnosis and clinical characteristics by etiological classification in early-onset epileptic encephalopathy with burst suppression pattern. Epilepsy Res 2020; 163:106323. [PMID: 32247221 DOI: 10.1016/j.eplepsyres.2020.106323] [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: 12/18/2019] [Revised: 03/01/2020] [Accepted: 03/20/2020] [Indexed: 01/17/2023]
Abstract
BACKGROUND Early-onset epileptic encephalopathies with burst suppression (EOEE-BS) are a group of neonatal epileptic syndromes characterized by intractable epilepsy and severe psychomotor delay with structural and metabolic factors accounting for major etiologies. However, recent advances in gene sequencing have identified that genetic factors might also play a significant role in the development of EOEE-BS. Herein, we used various genetic tests to identify pathogenic genetic variants in EOEE-BS irrespective of structural malformations and analyzed the clinical features associated with each different etiology. METHODS A total of 48 patients with EOEE-BS were included. Except for patients with severe hypoxic damage, patients with structural malformations were included in our patient cohort. Clinical features of the patients were reviewed, and etiological diagnoses were made based on several genetic tests, metabolic studies, and radiological findings. RESULT A genetic diagnosis was made in 31 (64.6 %) patients, with the most commonly diagnosed gene being STXBP1 (n = 13, 27.1 %), followed by KCNQ2 (n = 5, 10.4 %), SCN2A (n = 5, 10.4 %), DEPDC5 (n = 3, 6.3 %), CASK (n = 1, 2.1 %), CDKL5 (n = 1, 2.1 %), GNAO1 (n = 1, 2.1 %), SLC6A8 (n = 1, 2.1 %), and LIS1 deletion (n = 1, 2.1 %). Other than the classification of epilepsy syndrome, no clinical features were associated with the genetically diagnosed group. Among eight patients with structural malformations, genetic diagnosis was achieved in five (62.5 %), and those patients had pathogenic mutations in DEPDC5 and CASK or LIS1 deletion, indicating the significance of gene sequencing irrespective of structural abnormalities. Treatment responses to a variety of medications and the ketogenic diet differed by etiology, and surgical resection proved to be effective in patients with cortical dysplasia. CONCLUSION Genetic etiologies are an important factor in EOEE-BS irrespective of structural malformations and the treatment options may differ by etiology.
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Affiliation(s)
- Sangbo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Borahm Kim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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45
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Ionotropic Glutamate Receptors in Epilepsy: A Review Focusing on AMPA and NMDA Receptors. Biomolecules 2020; 10:biom10030464. [PMID: 32197322 PMCID: PMC7175173 DOI: 10.3390/biom10030464] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/13/2020] [Accepted: 03/14/2020] [Indexed: 12/22/2022] Open
Abstract
It is widely accepted that glutamate-mediated neuronal hyperexcitation plays a causative role in eliciting seizures. Among glutamate receptors, the roles of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in physiological and pathological conditions represent major clinical research targets. It is well known that agonists of NMDA or AMPA receptors can elicit seizures in animal or human subjects, while antagonists have been shown to inhibit seizures in animal models, suggesting a potential role for NMDA and AMPA receptor antagonists in anti-seizure drug development. Several such drugs have been evaluated in clinical studies; however, the majority, mainly NMDA-receptor antagonists, failed to demonstrate adequate efficacy and safety for therapeutic use, and only an AMPA-receptor antagonist, perampanel, has been approved for the treatment of some forms of epilepsy. These results suggest that a misunderstanding of the role of each glutamate receptor in the ictogenic process may underlie the failure of these drugs to demonstrate clinical efficacy and safety. Accumulating knowledge of both NMDA and AMPA receptors, including pathological gene mutations, roles in autoimmune epilepsy, and evidence from drug-discovery research and pharmacological studies, may provide valuable information enabling the roles of both receptors in ictogenesis to be reconsidered. This review aimed to integrate information from several studies in order to further elucidate the specific roles of NMDA and AMPA receptors in epilepsy.
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Synaptic GluN2A-Containing NMDA Receptors: From Physiology to Pathological Synaptic Plasticity. Int J Mol Sci 2020; 21:ijms21041538. [PMID: 32102377 PMCID: PMC7073220 DOI: 10.3390/ijms21041538] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/20/2020] [Accepted: 02/21/2020] [Indexed: 12/16/2022] Open
Abstract
N-Methyl-d-Aspartate Receptors (NMDARs) are ionotropic glutamate-gated receptors. NMDARs are tetramers composed by several homologous subunits of GluN1-, GluN2-, or GluN3-type, leading to the existence in the central nervous system of a high variety of receptor subtypes with different pharmacological and signaling properties. NMDAR subunit composition is strictly regulated during development and by activity-dependent synaptic plasticity. Given the differences between GluN2 regulatory subunits of NMDAR in several functions, here we will focus on the synaptic pool of NMDARs containing the GluN2A subunit, addressing its role in both physiology and pathological synaptic plasticity as well as the contribution in these events of different types of GluN2A-interacting proteins.
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47
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Vieira M, Yong XLH, Roche KW, Anggono V. Regulation of NMDA glutamate receptor functions by the GluN2 subunits. J Neurochem 2020; 154:121-143. [PMID: 31978252 DOI: 10.1111/jnc.14970] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/20/2019] [Accepted: 01/07/2020] [Indexed: 02/07/2023]
Abstract
The N-methyl-D-aspartate receptors (NMDARs) are ionotropic glutamate receptors that mediate the flux of calcium (Ca2+ ) into the post-synaptic compartment. Ca2+ influx subsequently triggers the activation of various intracellular signalling cascades that underpin multiple forms of synaptic plasticity. Functional NMDARs are assembled as heterotetramers composed of two obligatory GluN1 subunits and two GluN2 or GluN3 subunits. Four different GluN2 subunits (GluN2A-D) are present throughout the central nervous system; however, they are differentially expressed, both developmentally and spatially, in a cell- and synapse-specific manner. Each GluN2 subunit confers NMDARs with distinct ion channel properties and intracellular trafficking pathways. Regulated membrane trafficking of NMDARs is a dynamic process that ultimately determines the number of NMDARs at synapses, and is controlled by subunit-specific interactions with various intracellular regulatory proteins. Here we review recent progress made towards understanding the molecular mechanisms that regulate the trafficking of GluN2-containing NMDARs, focusing on the roles of several key synaptic proteins that interact with NMDARs via their carboxyl termini.
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Affiliation(s)
- Marta Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Xuan Ling Hilary Yong
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Qld, Australia
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Qld, Australia
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48
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Myers SJ, Yuan H, Kang JQ, Tan FCK, Traynelis SF, Low CM. Distinct roles of GRIN2A and GRIN2B variants in neurological conditions. F1000Res 2019; 8:F1000 Faculty Rev-1940. [PMID: 31807283 PMCID: PMC6871362 DOI: 10.12688/f1000research.18949.1] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/08/2019] [Indexed: 12/12/2022] Open
Abstract
Rapid advances in sequencing technology have led to an explosive increase in the number of genetic variants identified in patients with neurological disease and have also enabled the assembly of a robust database of variants in healthy individuals. A surprising number of variants in the GRIN genes that encode N-methyl-D-aspartate (NMDA) glutamatergic receptor subunits have been found in patients with various neuropsychiatric disorders, including autism spectrum disorders, epilepsy, intellectual disability, attention-deficit/hyperactivity disorder, and schizophrenia. This review compares and contrasts the available information describing the clinical and functional consequences of genetic variations in GRIN2A and GRIN2B. Comparison of clinical phenotypes shows that GRIN2A variants are commonly associated with an epileptic phenotype but that GRIN2B variants are commonly found in patients with neurodevelopmental disorders. These observations emphasize the distinct roles that the gene products serve in circuit function and suggest that functional analysis of GRIN2A and GRIN2B variation may provide insight into the molecular mechanisms, which will allow more accurate subclassification of clinical phenotypes. Furthermore, characterization of the pharmacological properties of variant receptors could provide the first opportunity for translational therapeutic strategies for these GRIN-related neurological and psychiatric disorders.
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Affiliation(s)
- Scott J Myers
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University, Atlanta, GA, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
| | - Hongjie Yuan
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University, Atlanta, GA, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
| | - Jing-Qiong Kang
- Department of Neurology, Vanderbilt Brain Institute, Vanderbilt Kennedy Center of Human Development, Vanderbilt University, Nashville, TN, USA
| | - Francis Chee Kuan Tan
- Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Stephen F Traynelis
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University, Atlanta, GA, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, USA
| | - Chian-Ming Low
- Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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49
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XiangWei W, Kannan V, Xu Y, Kosobucki GJ, Schulien AJ, Kusumoto H, Moufawad El Achkar C, Bhattacharya S, Lesca G, Nguyen S, Helbig KL, Cuisset JM, Fenger CD, Marjanovic D, Schuler E, Wu Y, Bao X, Zhang Y, Dirkx N, Schoonjans AS, Syrbe S, Myers SJ, Poduri A, Aizenman E, Traynelis SF, Lemke JR, Yuan H, Jiang Y. Heterogeneous clinical and functional features of GRIN2D-related developmental and epileptic encephalopathy. Brain 2019; 142:3009-3027. [PMID: 31504254 PMCID: PMC6763743 DOI: 10.1093/brain/awz232] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 04/30/2019] [Accepted: 05/31/2019] [Indexed: 01/08/2023] Open
Abstract
N-methyl d-aspartate receptors are ligand-gated ionotropic receptors mediating a slow, calcium-permeable component of excitatory synaptic transmission in the CNS. Variants in genes encoding NMDAR subunits have been associated with a spectrum of neurodevelopmental disorders. Here we report six novel GRIN2D variants and one previously-described disease-associated GRIN2D variant in two patients with developmental and epileptic encephalopathy. GRIN2D encodes for the GluN2D subunit protein; the GluN2D amino acids affected by the variants in this report are located in the pre-M1 helix, transmembrane domain M3, and the intracellular carboxyl terminal domain. Functional analysis in vitro reveals that all six variants decreased receptor surface expression, which may underline some shared clinical symptoms. In addition the GluN2D(Leu670Phe), (Ala675Thr) and (Ala678Asp) substitutions confer significantly enhanced agonist potency, and/or increased channel open probability, while the GluN2D(Ser573Phe), (Ser1271Phe) and (Arg1313Trp) substitutions result in a mild increase of agonist potency, reduced sensitivity to endogenous protons, and decreased channel open probability. The GluN2D(Ser573Phe), (Ala675Thr), and (Ala678Asp) substitutions significantly decrease current amplitude, consistent with reduced surface expression. The GluN2D(Leu670Phe) variant slows current response deactivation time course and increased charge transfer. GluN2D(Ala678Asp) transfection significantly decreased cell viability of rat cultured cortical neurons. In addition, we evaluated a set of FDA-approved NMDAR channel blockers to rescue functional changes of mutant receptors. This work suggests the complexity of the pathological mechanisms of GRIN2D-mediated developmental and epileptic encephalopathy, as well as the potential benefit of precision medicine.
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Affiliation(s)
- Wenshu XiangWei
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Varun Kannan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Gabrielle J Kosobucki
- Department of Neurobiology, University of Pittsburgh School of Medicine and Pittsburgh Institute for Neurodegenerative Diseases, Pittsburgh PA, USA
| | - Anthony J Schulien
- Department of Neurobiology, University of Pittsburgh School of Medicine and Pittsburgh Institute for Neurodegenerative Diseases, Pittsburgh PA, USA
| | - Hirofumi Kusumoto
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Christelle Moufawad El Achkar
- Division of Epilepsy, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Subhrajit Bhattacharya
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Gaetan Lesca
- Service de Genetique, Centre de Reference Anomalies du Developpement, Hospices Civils de Lyon, Bron, France; INSERM U1028, CNRS UMR5292, Paris, France
- Centre de Recherche en Neurosciences de Lyon, GENDEV Team, Universite Claude Bernard Lyon 1, Bron, France; Claude Bernard Lyon I University, Lyon, France
| | - Sylvie Nguyen
- Department of Pediatric Neurology, University Hospital of Lille, and Lille Reference Centre for Rare Epileptic Disorders, Lille, France
| | - Katherine L Helbig
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jean-Marie Cuisset
- Department of Pediatric Neurology, University Hospital of Lille, and Lille Reference Centre for Rare Epileptic Disorders, Lille, France
| | | | | | - Elisabeth Schuler
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ye Wu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Nina Dirkx
- Neurogenetics Group, University of Antwerp, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - An-Sofie Schoonjans
- Department of Child Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Steffen Syrbe
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, USA
| | - Annapurna Poduri
- Division of Epilepsy, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine and Pittsburgh Institute for Neurodegenerative Diseases, Pittsburgh PA, USA
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, USA
| | - Yuwu Jiang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
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50
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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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