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Donlon J, Kumari P, Varghese SP, Bai M, Florentin OD, Frost ED, Banks J, Vadlapatla N, Kam O, Shad MU, Rahman S, Abulseoud OA, Stone TW, Koola MM. Integrative Pharmacology in the Treatment of Substance Use Disorders. J Dual Diagn 2024; 20:132-177. [PMID: 38117676 DOI: 10.1080/15504263.2023.2293854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The detrimental physical, mental, and socioeconomic effects of substance use disorders (SUDs) have been apparent to the medical community for decades. However, it has become increasingly urgent in recent years to develop novel pharmacotherapies to treat SUDs. Currently, practitioners typically rely on monotherapy. Monotherapy has been shown to be superior to no treatment at all for most substance classes. However, many randomized controlled trials (RCTs) have revealed that monotherapy leads to poorer outcomes when compared with combination treatment in all specialties of medicine. The results of RCTs suggest that monotherapy frequently fails since multiple dysregulated pathways, enzymes, neurotransmitters, and receptors are involved in the pathophysiology of SUDs. As such, research is urgently needed to determine how various neurobiological mechanisms can be targeted by novel combination treatments to create increasingly specific yet exceedingly comprehensive approaches to SUD treatment. This article aims to review the neurobiology that integrates many pathophysiologic mechanisms and discuss integrative pharmacology developments that may ultimately improve clinical outcomes for patients with SUDs. Many neurobiological mechanisms are known to be involved in SUDs including dopaminergic, nicotinic, N-methyl-D-aspartate (NMDA), and kynurenic acid (KYNA) mechanisms. Emerging evidence indicates that KYNA, a tryptophan metabolite, modulates all these major pathophysiologic mechanisms. Therefore, achieving KYNA homeostasis by harmonizing integrative pathophysiology and pharmacology could prove to be a better therapeutic approach for SUDs. We propose KYNA-NMDA-α7nAChRcentric pathophysiology, the "conductor of the orchestra," as a novel approach to treat many SUDs concurrently. KYNA-NMDA-α7nAChR pathophysiology may be the "command center" of neuropsychiatry. To date, extant RCTs have shown equivocal findings across comparison conditions, possibly because investigators targeted single pathophysiologic mechanisms, hit wrong targets in underlying pathophysiologic mechanisms, and tested inadequate monotherapy treatment. We provide examples of potential combination treatments that simultaneously target multiple pathophysiologic mechanisms in addition to KYNA. Kynurenine pathway metabolism demonstrates the greatest potential as a target for neuropsychiatric diseases. The investigational medications with the most evidence include memantine, galantamine, and N-acetylcysteine. Future RCTs are warranted with novel combination treatments for SUDs. Multicenter RCTs with integrative pharmacology offer a promising, potentially fruitful avenue to develop novel therapeutics for the treatment of SUDs.
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Affiliation(s)
- Jack Donlon
- Cooper Medical School of Rowan University, Camden, New Jersey, USA
| | - Pooja Kumari
- Community Living Trent Highlands, Peterborough, Canada
| | - Sajoy P Varghese
- Addiction Recovery Treatment Services, Veterans Affairs Northern California Health Care System, University of California, Davis, Sacramento, California, USA
| | - Michael Bai
- Columbia University, New York, New York, USA
| | - Ori David Florentin
- Department of Psychiatry, Westchester Medical Center, Valhalla, New York, USA
| | - Emma D Frost
- Department of Neurology, Cooper University Health Care, Camden, New Jersey, USA
| | - John Banks
- Talkiatry Mental Health Clinic, New York, New York, USA
| | - Niyathi Vadlapatla
- Thomas Jefferson High School for Science and Technology, Alexandria, Virginia, USA
| | - Olivia Kam
- Stony Brook University Renaissance School of Medicine, Stony Brook, New York, USA
| | - Mujeeb U Shad
- Department of Psychiatry, University of Nevada Las Vegas, Las Vegas, Nevada, USA
| | - Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, South Dakota, USA
| | - Osama A Abulseoud
- Department of Psychiatry and Psychology, Alix School of Medicine at Mayo Clinic, Phoenix, Arizona, USA
| | - Trevor W Stone
- Nuffield Department of Orthopedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK
| | - Maju Mathew Koola
- Department of Psychiatry and Behavioral Health, Cooper University Health Care, Cooper Medical School of Rowan University, Camden, New Jersey, USA
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Karimi Tari P, Parsons CG, Collingridge GL, Rammes G. Memantine: Updating a rare success story in pro-cognitive therapeutics. Neuropharmacology 2024; 244:109737. [PMID: 37832633 DOI: 10.1016/j.neuropharm.2023.109737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023]
Abstract
The great potential for NMDA receptor modulators as druggable targets in neurodegenerative disorders has been met with limited success. Considered one of the rare exceptions, memantine has consistently demonstrated restorative and prophylactic properties in many AD models. In clinical trials memantine slows the decline in cognitive performance associated with AD. Here, we provide an overview of the basic properties including pharmacological targets, toxicology and cellular effects of memantine. Evidence demonstrating reductions in molecular, physiological and behavioural indices of AD-like impairments associated with memantine treatment are also discussed. This represents both an extension and homage to Dr. Chris Parson's considerable contributions to our fundamental understanding of a success story in the AD treatment landscape.
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Affiliation(s)
- Parisa Karimi Tari
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Chris G Parsons
- Galimedix Therapeutics, Inc., 2704 Calvend Lane, Kensington, 20895, MD, USA
| | - Graham L Collingridge
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada; Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada; TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| | - Gerhard Rammes
- Department of Anesthesiology and Intensive Care Medicine of the Technical University of Munich, School of Medicine, 22, 81675, Munich, Germany.
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Abstract
Major depressive disorder (MDD) is a leading cause of suicide in the world. Monoamine-based antidepressant drugs are a primary line of treatment for this mental disorder, although the delayed response and incomplete efficacy in some patients highlight the need for improved therapeutic approaches. Over the past two decades, ketamine has shown rapid onset with sustained (up to several days) antidepressant effects in patients whose MDD has not responded to conventional antidepressant drugs. Recent preclinical studies have started to elucidate the underlying mechanisms of ketamine's antidepressant properties. Herein, we describe and compare recent clinical and preclinical findings to provide a broad perspective of the relevant mechanisms for the antidepressant action of ketamine.
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Affiliation(s)
- Ji-Woon Kim
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA;
- College of Pharmacy, Kyung Hee University, Seoul, Republic of Korea
- Department of Regulatory Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Institute of Regulatory Innovation through Science, Kyung Hee University, Seoul, Republic of Korea
| | - Kanzo Suzuki
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA;
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Ege T Kavalali
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA;
| | - Lisa M Monteggia
- Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA;
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4
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Tsugiyama LE, Moraes RCM, Moraes YAC, Francis-Oliveira J. Promising new pharmacological targets for depression: The search for efficacy. Drug Discov Today 2023; 28:103804. [PMID: 37865307 DOI: 10.1016/j.drudis.2023.103804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/31/2023] [Accepted: 10/16/2023] [Indexed: 10/23/2023]
Abstract
Pharmacological treatment of major depressive disorder (MDD) still relies on the use of serotonergic drugs, despite their limited efficacy. A few mechanistically new drugs have been developed in recent years, but many fail in clinical trials. Several hypotheses have been proposed to explain MDD pathophysiology, indicating that physiological processes such as neuroplasticity, circadian rhythms, and metabolism are potential targets. Here, we review the current state of pharmacological treatments for MDD, as well as the preclinical and clinical evidence for an antidepressant effect of molecules that target non-serotonergic systems. We offer some insights into the challenges facing the development of new antidepressant drugs, and the prospect of finding more effectiveness for each target discussed.
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Affiliation(s)
- Lucila Emiko Tsugiyama
- Kansai Medical University, Graduate School of Medicine, iPS Cell Applied Medicine, Hirakata, Osaka, Japan
| | - Ruan Carlos Macedo Moraes
- University of Alabama at Birmingham, Department of Psychiatry and Behavioral Neurobiology, Birmingham, AL, USA; Biomedical Sciences Institute, Department of Human Physiology, Sao Paulo University, Sao Paulo, Brazil
| | | | - Jose Francis-Oliveira
- University of Alabama at Birmingham, Department of Psychiatry and Behavioral Neurobiology, Birmingham, AL, USA; Biomedical Sciences Institute, Department of Human Physiology, Sao Paulo University, Sao Paulo, Brazil.
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5
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Zhigulin AS, Barygin OI. Mechanisms of NMDA Receptor Inhibition by Sepimostat-Comparison with Nafamostat and Diarylamidine Compounds. Int J Mol Sci 2023; 24:15685. [PMID: 37958669 PMCID: PMC10649274 DOI: 10.3390/ijms242115685] [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: 09/27/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors are inhibited by many amidine and guanidine compounds. In this work, we studied the mechanisms of their inhibition by sepimostat-an amidine-containing serine protease inhibitor with neuroprotective properties. Sepimostat inhibited native NMDA receptors in rat hippocampal CA1 pyramidal neurons with IC50 of 3.5 ± 0.3 µM at -80 mV holding voltage. It demonstrated complex voltage dependence with voltage-independent and voltage-dependent components, suggesting the presence of shallow and deep binding sites. At -80 mV holding voltage, the voltage-dependent component dominates, and we observed pronounced tail currents and overshoots evidencing a "foot-in-the-door" open channel block. At depolarized voltages, the voltage-independent inhibition by sepimostat was significantly attenuated by the increase of agonist concentration. However, the voltage-independent inhibition was non-competitive. We further compared the mechanisms of the action of sepimostat with those of structurally-related amidine and guanidine compounds-nafamostat, gabexate, furamidine, pentamidine, diminazene, and DAPI-investigated previously. The action of all these compounds can be described by the two-component mechanism. All compounds demonstrated similar affinity to the shallow site, which is responsible for the voltage-independent inhibition, with binding constants in the range of 3-30 µM. In contrast, affinities to the deep site differed dramatically, with nafamostat, furamidine, and pentamidine being much more active.
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Affiliation(s)
| | - Oleg I. Barygin
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, 194223 Saint Petersburg, Russia;
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Kim JW, Suzuki K, Kavalali ET, Monteggia LM. Bridging rapid and sustained antidepressant effects of ketamine. Trends Mol Med 2023; 29:364-375. [PMID: 36907686 PMCID: PMC10101916 DOI: 10.1016/j.molmed.2023.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/05/2023] [Accepted: 02/15/2023] [Indexed: 03/12/2023]
Abstract
Acute administration of (R,S)-ketamine (ketamine) produces rapid antidepressant effects that in some patients can be sustained for several days to more than a week. Ketamine blocks N-methyl-d-asparate (NMDA) receptors (NMDARs) to elicit specific downstream signaling that induces a novel form of synaptic plasticity in the hippocampus that has been linked to the rapid antidepressant action. These signaling events lead to subsequent downstream transcriptional changes that are involved in the sustained antidepressant effects. Here we review how ketamine triggers this intracellular signaling pathway to mediate synaptic plasticity which underlies the rapid antidepressant effects and links it to downstream signaling and the sustained antidepressant effects.
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Affiliation(s)
- Ji-Woon Kim
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA; College of Pharmacy, Kyung Hee University, Seoul, Republic of Korea; Department of Regulatory Science, Gradaute School, Kyung Hee University, Seoul, Republic of Korea; Institute of Regulatory Innovation through Science, Kyung Hee University, Seoul, Republic of Korea
| | - Kanzo Suzuki
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA; Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Katsushika-ku, Japan
| | - Ege T Kavalali
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA
| | - Lisa M Monteggia
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA.
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Kolcheva M, Ladislav M, Netolicky J, Kortus S, Rehakova K, Krausova BH, Hemelikova K, Misiachna A, Kadkova A, Klima M, Chalupska D, Horak M. The pathogenic N650K variant in the GluN1 subunit regulates the trafficking, conductance, and pharmacological properties of NMDA receptors. Neuropharmacology 2023; 222:109297. [PMID: 36341805 DOI: 10.1016/j.neuropharm.2022.109297] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/07/2022] [Accepted: 10/18/2022] [Indexed: 11/05/2022]
Abstract
N-methyl-D-aspartate receptors (NMDARs) play an essential role in excitatory neurotransmission in the mammalian brain, and their physiological importance is underscored by the large number of pathogenic mutations that have been identified in the receptor's GluN subunits and associated with a wide range of diseases and disorders. Here, we characterized the functional and pharmacological effects of the pathogenic N650K variant in the GluN1 subunit, which is associated with developmental delay and seizures. Our microscopy experiments showed that when expressed in HEK293 cells (from ATCC®), the GluN1-N650K subunit increases the surface expression of both GluN1/GluN2A and GluN1/GluN2B receptors, but not GluN1/GluN3A receptors, consistent with increased surface expression of the GluN1-N650K subunit expressed in hippocampal neurons (from embryonic day 18 of Wistar rats of both sexes). Using electrophysiology, we found that the GluN1-N650K variant increases the potency of GluN1/GluN2A receptors to both glutamate and glycine but decreases the receptor's conductance and open probability. In addition, the GluN1-N650K subunit does not form functional GluN1/GluN2B receptors but does form fully functional GluN1/GluN3A receptors. Moreover, in the presence of extracellular Mg2+, GluN1-N650K/GluN2A receptors have a similar and increased response to ketamine and memantine, respectively, while the effect of both drugs had markedly slower onset and offset compared to wild-type GluN1/GluN2A receptors. Finally, we found that expressing the GluN1-N650K subunit in hippocampal neurons reduces excitotoxicity, and memantine shows promising neuroprotective effects in neurons expressing either wild-type GluN1 or the GluN1-N650K subunit. This study provides the functional and pharmacological characterization of NMDARs containing the GluN1-N650K variant.
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Affiliation(s)
- Marharyta Kolcheva
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic; Department of Physiology, Faculty of Science, Charles University in Prague, Albertov 6, 12843, Prague 2, Czech Republic; Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Marek Ladislav
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Jakub Netolicky
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic; Department of Physiology, Faculty of Science, Charles University in Prague, Albertov 6, 12843, Prague 2, Czech Republic
| | - Stepan Kortus
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Kristyna Rehakova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Barbora Hrcka Krausova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Katarina Hemelikova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Anna Misiachna
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Anna Kadkova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Martin Klima
- Department of Molecular Biology and Biochemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, P.O. Box:16000, Prague 6, Czech Republic
| | - Dominika Chalupska
- Department of Molecular Biology and Biochemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, P.O. Box:16000, Prague 6, Czech Republic
| | - Martin Horak
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic.
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8
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Inhibition of NMDA receptors through a membrane-to-channel path. Nat Commun 2022; 13:4114. [PMID: 35840593 PMCID: PMC9287434 DOI: 10.1038/s41467-022-31817-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 07/05/2022] [Indexed: 11/21/2022] Open
Abstract
N-methyl-d-aspartate receptors (NMDARs) are transmembrane proteins that are activated by the neurotransmitter glutamate and are found at most excitatory vertebrate synapses. NMDAR channel blockers, an antagonist class of broad pharmacological and clinical significance, inhibit by occluding the NMDAR ion channel. A vast literature demonstrates that NMDAR channel blockers, including MK-801, phencyclidine, ketamine, and the Alzheimer’s disease drug memantine, can bind and unbind only when the NMDAR channel is open. Here we use electrophysiological recordings from transfected tsA201 cells and cultured neurons, NMDAR structural modeling, and custom-synthesized compounds to show that NMDAR channel blockers can enter the channel through two routes: the well-known hydrophilic path from extracellular solution to channel through the open channel gate, and also a hydrophobic path from plasma membrane to channel through a gated fenestration (“membrane-to-channel inhibition” (MCI)). Our demonstration that ligand-gated channels are subject to MCI, as are voltage-gated channels, highlights the broad expression of this inhibitory mechanism. Wilcox et al. (2022) show that NMDA receptor channel blockers, some of which are clinically important drugs, can access their binding site via 2 routes: a well-known path from the extracellular solution, and another path through the plasma membrane.
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Turcu AL, Companys-Alemany J, Phillips MB, Patel DS, Griñán-Ferré C, Loza MI, Brea JM, Pérez B, Soto D, Sureda FX, Kurnikova MG, Johnson JW, Pallàs M, Vázquez S. Design, synthesis, and in vitro and in vivo characterization of new memantine analogs for Alzheimer's disease. Eur J Med Chem 2022; 236:114354. [PMID: 35453065 DOI: 10.1016/j.ejmech.2022.114354] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/28/2022]
Abstract
Currently, of the few accessible symptomatic therapies for Alzheimer's disease (AD), memantine is the only N-methyl-d-aspartate receptor (NMDAR) blocker approved by the FDA. This work further explores a series of memantine analogs featuring a benzohomoadamantane scaffold. Most of the newly synthesized compounds block NMDARs in the micromolar range, but with lower potency than previously reported hit IIc, results that were supported by molecular dynamics simulations. Subsequently, electrophysiological studies with the more potent compounds allowed classification of IIc, a low micromolar, uncompetitive, voltage-dependent, NMDAR blocker, as a memantine-like compound. The excellent in vitro DMPK properties of IIc made it a promising candidate for in vivo studies in Caenorhabditis elegans (C. elegans) and in the 5XFAD mouse model of AD. Administration of IIc or memantine improved locomotion and rescues chemotaxis behavior in C. elegans. Furthermore, both compounds enhanced working memory in 5XFAD mice and modified NMDAR and CREB signaling, which may prevent synaptic dysfunction and modulate neurodegenerative progression.
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Affiliation(s)
- Andreea L Turcu
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia i Ciències de l'Alimentació i Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain; Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08036, Barcelona, Spain
| | - Júlia Companys-Alemany
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neurosciences (NeuroUB), Universitat de Barcelona, Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - Matthew B Phillips
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Dhilon S Patel
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Christian Griñán-Ferré
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neurosciences (NeuroUB), Universitat de Barcelona, Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - M Isabel Loza
- Innopharma Screening Platform, Biofarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, Edificio CIMUS, Av. Barcelona, S/N, E, 15706, Santiago de Compostela, Spain
| | - José M Brea
- Innopharma Screening Platform, Biofarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, Edificio CIMUS, Av. Barcelona, S/N, E, 15706, Santiago de Compostela, Spain
| | - Belén Pérez
- Department of Pharmacology, Therapeutics and Toxicology, Autonomous University of Barcelona, E-08193, Bellaterra, Spain
| | - David Soto
- Neurophysiology Laboratory, Department of Biomedicine, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08036, Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Francesc X Sureda
- Pharmacology Unit, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C./ St. Llorenç 21, 43201, Reus, Tarragona, Spain
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Jon W Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Mercè Pallàs
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neurosciences (NeuroUB), Universitat de Barcelona, Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - Santiago Vázquez
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia i Ciències de l'Alimentació i Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain.
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10
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Stepanenko YD, Sibarov DA, Shestakova NN, Antonov SM. Tricyclic Antidepressant Structure-Related Alterations in Calcium-Dependent Inhibition and Open-Channel Block of NMDA Receptors. Front Pharmacol 2022; 12:815368. [PMID: 35237149 PMCID: PMC8882908 DOI: 10.3389/fphar.2021.815368] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/27/2021] [Indexed: 12/30/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are an essential target for the analgetic action of tricyclic antidepressants (TCAs). Their therapeutic blood concentrations achieve 0.5–1.5 μM, which, however, are insufficient to cause in vitro the open-channel block known as the only effect of TCAs on NMDARs. Whereas structures of amitriptyline (ATL), desipramine (DES), and clomipramine (CLO) are rather similar these compounds manifest different therapeutic profiles and side effects. To study structure-activity relationships of DES and CLO on NMDARs, we measured IC50s as a function of extracellular calcium ([Ca2+]) and membrane voltage (Vm) of NMDAR currents recorded in cortical neurons. Here two components of TCA action on NMDARs are described, which could be characterized as the Ca2+-dependent inhibition and the open-channel block. DES demonstrated a profound Ca2+-dependent inhibition of NMDARs, while the CLO effect was weak. DES IC50 exhibited an e-fold change with a [Ca2+] shift of 0.59 mM, which is consistent with ATL. The Ca2+ dependence of NMDAR inhibition by DES disappeared in BAPTA loaded neurons, suggesting that Ca2+ acts from the inside. Since CLO differs from DES and ATL by the presence of Cl-atom in the structure, most likely, this is the atom which is responsible for the loss of pronounced [Ca2+] dependence. As for the NMDAR open-channel block, both DES and CLO were about 5-folds more potent than ATL due to their slow rates of dissociation either from open and closed states. DES demonstrated stronger Vm-dependence than CLO, suggesting a deeper location of the DES binding site within the ion pore. Because DES and CLO differ from ATL by the nitrogen-containing tricycle, presumably this moiety of the molecules determines their high-affinity binding with the NMDAR channel, while the aliphatic chain mono-methyl amino-group of DES allows a deep permeation in the channel. Thus, different structure-activity relationships of the Ca2+-dependent inhibition and Vm-dependent open-channel block of NMDARs by DES and CLO suggest that these processes are independent and most likely may represent an action on different molecular targets. The proposed model of TCA action on NMDARs predicts well the experimental values of IC50s at physiological [Ca2+] and within a wide range of Vms.
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11
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Zhigulin AS, Barygin OI. Mechanisms of NMDA receptor inhibition by nafamostat, gabexate and furamidine. Eur J Pharmacol 2022; 919:174795. [PMID: 35122868 DOI: 10.1016/j.ejphar.2022.174795] [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: 08/30/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 11/03/2022]
Abstract
N-methyl-D-aspartate (NMDA) receptors are affected by many pharmaceuticals. In this work, we studied the action of the serine protease inhibitors nafamostat, gabexate and camostat, and an antiprotozoal compound, furamidine, on native NMDA receptors in rat hippocampal pyramidal neurons. Nafamostat, furamidine and gabexate inhibited these receptors with IC50 values of 0.20 ± 0.04, 0.64 ± 0.13 and 16 ± 3 μM, respectively, whereas camostat was ineffective. Nafamostat and furamidine showed voltage-dependent inhibition, while gabexate showed practically voltage-independent inhibition. Nafamostat and furamidine demonstrated tail currents, implying a 'foot-in-the-door' mechanism of action; gabexate did not demonstrate any signs of 'foot-in-the-door' or trapping channel block. Gabexate action was also not competitive, suggesting allosteric inhibition of NMDA receptors. Furamidine and nafamostat are structurally similar to the previously studied diminazene and all three demonstrated a 'foot-in-the-door' mechanism. They have a rather rigid, elongated structures and cannot fold into more compact forms. By contrast, the gabexate molecule can fold, but its folded structure differs drastically from that of typical NMDA receptor blockers, in agreement with its voltage-independent inhibition. These findings provide a better understanding of the structural determinants of NMDA receptor antagonism, while also supporting the potential clinical repurposing of these drugs as neuroprotectors for glaucoma and other neurodegenerative diseases.
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Affiliation(s)
- Arseniy S Zhigulin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - Oleg I Barygin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia.
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12
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Lazarova M, Tancheva L, Chayrov R, Tzvetanova E, Alexandrova A, Popatanasov A, Uzunova D, Stefanova M, Stankova I, Kalfin R. Tyrosinyl-amantadine: A New Amantadine Derivative With an Ameliorative Effect in a 6-OHDA Experimental Model of Parkinson's Disease in Rats. J Mol Neurosci 2022; 72:900-909. [PMID: 35091981 DOI: 10.1007/s12031-021-01964-x] [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: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 10/19/2022]
Abstract
The neuroprotective capacity of newly synthesized amantadine derivative tyrosinyl-amantadine (Tyr-Am) with expected antiparkinsonian properties was evaluated in a 6-hydroxydopamine (6-OHDA) model of Parkinson's disease. Male Wistar rats were divided into the following groups: sham-operated (SO), striatal 6-OHDA-lesioned control group, 6-OHDA-lesioned rats pretreated for 6 days with Tyr-Am (16 mg/kg administered intraperitoneally, i.p.), and 6-OHDA-lesioned rats pretreated for 6 days with amantadine (40 mg/kg i.p.), used as a referent. On the first, second and third week post-lesion, the animals were subjected to some behavioral tests (apomorphine-induced rotation, rotarod, and passive avoidance test). The acetylcholinesterase (AChE) activity and key oxidative stress parameters including lipid peroxidation levels (LPO) and superoxide dismutase (SOD) were measured in brain homogenates. The results showed that the neuroprotective effect of Tyr-Am was comparable to that of amantadine, improving neuromuscular coordination and learning and memory performance even at a 2.5-fold lower dose. Tyr-Am demonstrated significant antioxidant properties via decreased LPO levels but had no effect on AChE activity. We can conclude that the newly synthesized amantadine derivative Tyr-Am demonstrated significant antiparkinsonian activity in a 6-OHDA experimental model.
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Affiliation(s)
- Maria Lazarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria.
| | - Lyubka Tancheva
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Radoslav Chayrov
- Department of Chemistry, South-West University "Neofit Rilski", Ivan Mihailov St. 66, Blagoevgrad,, 2700, Bulgaria
| | - Elina Tzvetanova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Albena Alexandrova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Andrey Popatanasov
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Diamara Uzunova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Miroslava Stefanova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria
| | - Ivanka Stankova
- Department of Chemistry, South-West University "Neofit Rilski", Ivan Mihailov St. 66, Blagoevgrad,, 2700, Bulgaria
| | - Reni Kalfin
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, Block 23, Sofia,, 1113, Bulgaria.,Faculty of Public Health, Healthcare and Sport, South-West University "Neofit Rilski", Ivan Mihailov St. 66, Blagoevgrad,, 2700, Bulgaria
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13
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Dron MY, Zhigulin AS, Tikhonov DB, Barygin OI. Screening for Activity Against AMPA Receptors Among Anticonvulsants-Focus on Phenytoin. Front Pharmacol 2021; 12:775040. [PMID: 34950035 PMCID: PMC8688955 DOI: 10.3389/fphar.2021.775040] [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: 09/13/2021] [Accepted: 10/20/2021] [Indexed: 11/13/2022] Open
Abstract
The interest in AMPA receptors as a target for epilepsy treatment increased substantially after the approval of perampanel, a negative AMPA receptor allosteric antagonist, for the treatment of partial-onset seizures and generalized tonic-clonic seizures. Here we performed a screening for activity against native calcium-permeable AMPA receptors (CP-AMPARs) and calcium-impermeable AMPA receptors (CI-AMPARs) among different anticonvulsants using the whole-cell patch-clamp method on isolated Wistar rat brain neurons. Lamotrigine, topiramate, levetiracetam, felbamate, carbamazepine, tiagabin, vigabatrin, zonisamide, and gabapentin in 100-µM concentration were practically inactive against both major subtypes of AMPARs, while phenytoin reversibly inhibited them with IC50 of 30 ± 4 μM and 250 ± 60 µM for CI-AMPARs and CP-AMPARs, respectively. The action of phenytoin on CI-AMPARs was attenuated in experiments with high agonist concentrations, in the presence of cyclothiazide and at pH 9.0. Features of phenytoin action matched those of the CI-AMPARs pore blocker pentobarbital, being different from classical competitive inhibitors, negative allosteric inhibitors, and CP-AMPARs selective channel blockers. Close 3D similarity between phenytoin and pentobarbital also suggests a common binding site in the pore and mechanism of inhibition. The main target for phenytoin in the brain, which is believed to underlie its anticonvulsant properties, are voltage-gated sodium channels. Here we have shown for the first time that phenytoin inhibits CI-AMPARs with similar potency. Thus, AMPAR inhibition by phenytoin may contribute to its anticonvulsant properties as well as its side effects.
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Affiliation(s)
- M Y Dron
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - A S Zhigulin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - D B Tikhonov
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - O I Barygin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
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14
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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: 212] [Impact Index Per Article: 70.7] [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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15
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Kohtala S. Ketamine-50 years in use: from anesthesia to rapid antidepressant effects and neurobiological mechanisms. Pharmacol Rep 2021; 73:323-345. [PMID: 33609274 PMCID: PMC7994242 DOI: 10.1007/s43440-021-00232-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 12/11/2022]
Abstract
Over the past 50 years, ketamine has solidified its position in both human and veterinary medicine as an important anesthetic with many uses. More recently, ketamine has been studied and used for several new indications, ranging from chronic pain to drug addiction and post-traumatic stress disorder. The discovery of the rapid-acting antidepressant effects of ketamine has resulted in a surge of interest towards understanding the precise mechanisms driving its effects. Indeed, ketamine may have had the largest impact for advancements in the research and treatment of psychiatric disorders in the past few decades. While intense research efforts have been aimed towards uncovering the molecular targets underlying ketamine's effects in treating depression, the underlying neurobiological mechanisms remain elusive. These efforts are made more difficult by ketamine's complex dose-dependent effects on molecular mechanisms, multiple pharmacologically active metabolites, and a mechanism of action associated with the facilitation of synaptic plasticity. This review aims to provide a brief overview of the different uses of ketamine, with an emphasis on examining ketamine's rapid antidepressant effects spanning molecular, cellular, and network levels. Another focus of the review is to offer a perspective on studies related to the different doses of ketamine used in antidepressant research. Finally, the review discusses some of the latest hypotheses concerning ketamine's action.
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Affiliation(s)
- Samuel Kohtala
- Laboratory of Neurotherapeutics, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, P. O. Box 56, 00014, Helsinki, Finland.
- SleepWell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- Feil Family Brain and Mind Research Institute, Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA.
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Kolcheva M, Kortus S, Krausova BH, Barackova P, Misiachna A, Danacikova S, Kaniakova M, Hemelikova K, Hotovec M, Rehakova K, Horak M. Specific pathogenic mutations in the M3 domain of the GluN1 subunit regulate the surface delivery and pharmacological sensitivity of NMDA receptors. Neuropharmacology 2021; 189:108528. [PMID: 33773999 DOI: 10.1016/j.neuropharm.2021.108528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/03/2021] [Accepted: 03/03/2021] [Indexed: 12/25/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) play an essential role in regulating glutamatergic neurotransmission. Recently, pathogenic missense mutations were identified in genes encoding NMDAR subunits; however, their effect on NMDAR activity is often poorly understood. Here, we examined whether three previously identified pathogenic mutations (M641I, A645S, and Y647S) in the M3 domain of the GluN1 subunit affect the receptor's surface delivery, agonist sensitivity, Mg2+ block, and/or inhibition by the FDA-approved NMDAR blocker memantine. When expressed in HEK293 cells, we found reduced surface expression of GluN1-M641I/GluN2A, GluN1-Y647S/GluN2A, and GluN1-Y647S/GluN2B receptors; other mutation-bearing NMDAR combinations, including GluN1/GluN3A receptors, were expressed at normal surface levels. When expressed in rat hippocampal neurons, we consistently found reduced surface expression of the GluN1-M641I and GluN1-Y647S subunits when compared with wild-type GluN1 subunit. At the functional level, we found that GluN1-M641I/GluN2 and GluN1-A645S/GluN2 receptors expressed in HEK293 cells have wild-type EC50 values for both glutamate and glycine; in contrast, GluN1-Y647S/GluN2 receptors do not produce glutamate-induced currents. In the presence of a physiological concentration of Mg2+, we found that GluN1-M641I/GluN2 receptors have a lower memantine IC50 and slower offset kinetics, whereas GluN1-A645S/GluN2 receptors have a higher memantine IC50 and faster offset kinetics when compared to wild-type receptors. Finally, we found that memantine was the most neuroprotective in hippocampal neurons expressing GluN1-M641I subunits, followed by neurons expressing wild-type GluN1 and then GluN1-A645S subunits in an NMDA-induced excitotoxicity assay. These results indicate that specific pathogenic mutations in the M3 domain of the GluN1 subunit differentially affect the trafficking and functional properties of NMDARs.
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Affiliation(s)
- Marharyta Kolcheva
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic; Department of Physiology, Faculty of Science, Charles University in Prague, Albertov 6, 12843, Prague 2, Czech Republic; Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Stepan Kortus
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Barbora Hrcka Krausova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Petra Barackova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Anna Misiachna
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Sarka Danacikova
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Martina Kaniakova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Katarina Hemelikova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Matej Hotovec
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Kristyna Rehakova
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Martin Horak
- Department of Neurochemistry, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic.
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17
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Tikhonov DB. Channel Blockers of Ionotropic Glutamate
Receptors. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Danysz W, Dekundy A, Scheschonka A, Riederer P. Amantadine: reappraisal of the timeless diamond-target updates and novel therapeutic potentials. J Neural Transm (Vienna) 2021; 128:127-169. [PMID: 33624170 PMCID: PMC7901515 DOI: 10.1007/s00702-021-02306-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/13/2021] [Indexed: 12/30/2022]
Abstract
The aim of the current review was to provide a new, in-depth insight into possible pharmacological targets of amantadine to pave the way to extending its therapeutic use to further indications beyond Parkinson's disease symptoms and viral infections. Considering amantadine's affinities in vitro and the expected concentration at targets at therapeutic doses in humans, the following primary targets seem to be most plausible: aromatic amino acids decarboxylase, glial-cell derived neurotrophic factor, sigma-1 receptors, phosphodiesterases, and nicotinic receptors. Further three targets could play a role to a lesser extent: NMDA receptors, 5-HT3 receptors, and potassium channels. Based on published clinical studies, traumatic brain injury, fatigue [e.g., in multiple sclerosis (MS)], and chorea in Huntington's disease should be regarded potential, encouraging indications. Preclinical investigations suggest amantadine's therapeutic potential in several further indications such as: depression, recovery after spinal cord injury, neuroprotection in MS, and cutaneous pain. Query in the database http://www.clinicaltrials.gov reveals research interest in several further indications: cancer, autism, cocaine abuse, MS, diabetes, attention deficit-hyperactivity disorder, obesity, and schizophrenia.
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Affiliation(s)
- Wojciech Danysz
- Merz Pharmaceuticals GmbH., Eckenheimer Landstraße 100, 60318, Frankfurt am Main, Germany
| | - Andrzej Dekundy
- Merz Pharmaceuticals GmbH., Eckenheimer Landstraße 100, 60318, Frankfurt am Main, Germany
| | - Astrid Scheschonka
- Merz Pharmaceuticals GmbH., Eckenheimer Landstraße 100, 60318, Frankfurt am Main, Germany
| | - Peter Riederer
- Clinic and Policlinic for Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, University of Würzburg, Margarete-Höppel-Platz 1, 97080, Würzburg, Germany.
- Department Psychiatry, University of Southern Denmark Odense, Vinslows Vey 18, 5000, Odense, Denmark.
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Vova JA. A narrative review of pharmacologic approaches to symptom management of pediatric patients diagnosed with anti-NMDA receptor encephalitis. J Pediatr Rehabil Med 2021; 14:333-343. [PMID: 34486993 DOI: 10.3233/prm-200677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Anti-N-Methyl-D-Aspartate Receptor Encephalitis (ANMDARE) is one of the most common autoimmune encephalitis in the pediatric population. Patients with ANMDARE initially present with a prodrome of neuropsychiatric symptoms followed by progressively worsening seizures, agitation, and movement disorders. Complications can include problems such as aggression, insomnia, catatonia, and autonomic instability. Due to the complexity of this disease process, symptom management can be complex and may lead to significant polypharmacy. The goal of this review is to educate clinicians about the challenges of managing this disorder and providing guidance in symptom management.
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Affiliation(s)
- Joshua A Vova
- Department of Physiatry, Children's Healthcare of Atlanta, Johnson Ferry Rd NE. Atlanta, GA, USA
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Rahić O, Tucak A, Omerović N, Sirbubalo M, Hindija L, Hadžiabdić J, Vranić E. Novel Drug Delivery Systems Fighting Glaucoma: Formulation Obstacles and Solutions. Pharmaceutics 2020; 13:E28. [PMID: 33375224 PMCID: PMC7824381 DOI: 10.3390/pharmaceutics13010028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is considered to be one of the biggest health problems in the world. It is the main cause of preventable blindness due to its asymptomatic nature in the early stages on the one hand and patients' non-adherence on the other. There are several approaches in glaucoma treatment, whereby this has to be individually designed for each patient. The first-line treatment is medication therapy. However, taking into account numerous disadvantages of conventional ophthalmic dosage forms, intensive work has been carried out on the development of novel drug delivery systems for glaucoma. This review aims to provide an overview of formulation solutions and strategies in the development of in situ gel systems, nanosystems, ocular inserts, contact lenses, collagen corneal shields, ocular implants, microneedles, and iontophoretic devices. The results of studies confirming the effectiveness of the aforementioned drug delivery systems were also briefly presented.
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Affiliation(s)
- Ognjenka Rahić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Amina Tucak
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Naida Omerović
- Department of Clinical Pharmacy, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Merima Sirbubalo
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Lamija Hindija
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Jasmina Hadžiabdić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Edina Vranić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
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21
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Molecular mechanisms of action determine inhibition of paroxysmal depolarizing shifts by NMDA receptor antagonists in rat cortical neurons. Neuropharmacology 2020; 184:108443. [PMID: 33345828 DOI: 10.1016/j.neuropharm.2020.108443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 12/03/2020] [Accepted: 12/15/2020] [Indexed: 01/28/2023]
Abstract
N-methyl-d-aspartate glutamate receptors (NMDARs) are involved in numerous central nervous system (CNS) processes, including epileptiform activity. We used a picrotoxin-induced epileptiform activity model to compare the action of different types of NMDAR antagonists in rat brain slices. Paroxysmal depolarizing shifts (PDS) were evoked by external stimulation in the medial prefrontal cortex (mPFC) slices and recorded in pyramidal cells (PC) and in fast-spiking interneurons (FSI). The NMDAR antagonists APV and memantine reduced the duration of PDS. However, the competitive antagonist APV caused similar effects on the PC and FSI, while the open-channel blocker memantine had a much stronger effect on the PDS in the FSI than in the PC. This difference cannot be explained by a corresponding difference in NMDAR sensitivity to memantine because the drug inhibited the excitatory postsynaptic current (EPSC) similarly in both cell types. Importantly, the PDS were significantly longer in the FSI than in the PC. The degree of PDS inhibition by memantine correlated with individual PDS durations in each cell type. Computer modeling of a synaptic network in the mPFC suggests that the different effects of memantine on the PDS in the PC and FSI can be explained by use dependence of its action. An open-channel blocking mechanism and competition with Mg2+ ions for the binding site result in pronounced inhibition of the long PDS, whereas the short PDS are weakly sensitive. Our results show that peculiarities of kinetics and the mechanism of action largely determine the effects of NMDAR antagonists on physiological and/or pathological processes.
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22
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Phillips MB, Nigam A, Johnson JW. Interplay between Gating and Block of Ligand-Gated Ion Channels. Brain Sci 2020; 10:brainsci10120928. [PMID: 33271923 PMCID: PMC7760600 DOI: 10.3390/brainsci10120928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/21/2020] [Accepted: 11/26/2020] [Indexed: 02/03/2023] Open
Abstract
Drugs that inhibit ion channel function by binding in the channel and preventing current flow, known as channel blockers, can be used as powerful tools for analysis of channel properties. Channel blockers are used to probe both the sophisticated structure and basic biophysical properties of ion channels. Gating, the mechanism that controls the opening and closing of ion channels, can be profoundly influenced by channel blocking drugs. Channel block and gating are reciprocally connected; gating controls access of channel blockers to their binding sites, and channel-blocking drugs can have profound and diverse effects on the rates of gating transitions and on the stability of channel open and closed states. This review synthesizes knowledge of the inherent intertwining of block and gating of excitatory ligand-gated ion channels, with a focus on the utility of channel blockers as analytic probes of ionotropic glutamate receptor channel function.
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Affiliation(s)
- Matthew B. Phillips
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Aparna Nigam
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
| | - Jon W. Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Correspondence: ; Tel.: +1-(412)-624-4295
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23
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Kaniakova M, Nepovimova E, Kleteckova L, Skrenkova K, Holubova K, Chrienova Z, Hepnarova V, Kucera T, Kobrlova T, Vales K, Korabecny J, Soukup O, Horak M. Combination of Memantine and 6-Chlorotacrine as Novel Multi-Target Compound against Alzheimer's Disease. Curr Alzheimer Res 2020; 16:821-833. [PMID: 30819076 DOI: 10.2174/1567205016666190228122218] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 01/04/2019] [Accepted: 01/31/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common form of dementia in the elderly. It is characterized as a multi-factorial disorder with a prevalent genetic component. Due to the unknown etiology, current treatment based on acetylcholinesterase (AChE) inhibitors and N-methyl-D-aspartate receptors (NMDAR) antagonist is effective only temporary. It seems that curative treatment will necessarily be complex due to the multifactorial nature of the disease. In this context, the so-called "multi-targeting" approach has been established. OBJECTIVES The aim of this study was to develop a multi-target-directed ligand (MTDL) combining the support for the cholinergic system by inhibition of AChE and at the same time ameliorating the burden caused by glutamate excitotoxicity mediated by the NMDAR receptors. METHODS We have applied common approaches of organic chemistry to prepare a hybrid of 6-chlorotacrine and memantine. Then, we investigated its blocking ability towards AChE and NMDRS in vitro, as well as its neuroprotective efficacy in vivo in the model of NMDA-induced lessions. We also studied cytotoxic potential of the compound and predicted the ability to cross the blood-brain barrier. RESULTS A novel molecule formed by combination of 6-chlorotacrine and memantine proved to be a promising multipotent hybrid capable of blocking the action of AChE as well as NMDARs. The presented hybrid surpassed the AChE inhibitory activity of the parent compound 6-Cl-THA twofold. According to results it has been revealed that our novel hybrid blocks NMDARs in the same manner as memantine, potently inhibits AChE and is predicted to cross the blood-brain barrier via passive diffusion. Finally, the MTDL design strategy was indicated by in vivo results which showed that the novel 6-Cl-THA-memantine hybrid displayed a quantitatively better neuroprotective effect than the parent compound memantine. CONCLUSION We conclude that the combination of two pharmacophores with a synergistic mechanism of action into a single molecule offers great potential for the treatment of CNS disorders associated with cognitive decline and/or excitotoxicity mediated by NMDARs.
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Affiliation(s)
- Martina Kaniakova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic.,Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Lenka Kleteckova
- National Institute of Mental Health, Topolova 748, 250 67 Klecany, Czech Republic
| | - Kristyna Skrenkova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Kristina Holubova
- National Institute of Mental Health, Topolova 748, 250 67 Klecany, Czech Republic
| | - Zofia Chrienova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Vendula Hepnarova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove 500 05, Czech Republic
| | - Tomas Kucera
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove 500 05, Czech Republic
| | - Tereza Kobrlova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove 500 05, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Karel Vales
- National Institute of Mental Health, Topolova 748, 250 67 Klecany, Czech Republic
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Martin Horak
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic.,Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, Videnska 1083, 14220 Prague 4, Czech Republic
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24
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Kikuchi T. Is Memantine Effective as an NMDA-Receptor Antagonist in Adjunctive Therapy for Schizophrenia? Biomolecules 2020; 10:biom10081134. [PMID: 32751985 PMCID: PMC7466074 DOI: 10.3390/biom10081134] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 01/07/2023] Open
Abstract
Memantine, an n-methyl-d-aspartate (NMDA) receptor antagonist approved for treating Alzheimer's disease, has a good safety profile and is increasingly being studied for possible use in a variety of non-dementia psychiatric disorders. There is an abundance of basic and clinical data that support the hypothesis that NMDA receptor hypofunction contributes to the pathophysiology of schizophrenia. However, there are numerous randomized, double-blind, placebo-controlled clinical trials showing that add-on treatment with memantine improves negative and cognitive symptoms, particularly the negative symptoms of schizophrenia, indicating that memantine as adjunctive therapy in schizophrenia helps to ameliorate negative symptoms and cognitive deficits. It remains unclear why memantine does not show undesirable central nervous system (CNS) side effects in humans unlike other NMDA receptor antagonists, such as phencyclidine and ketamine. However, the answer could lie in the fact that it would appear that memantine works as a low-affinity, fast off-rate, voltage-dependent, and uncompetitive antagonist with preferential inhibition of extrasynaptic receptors. It is reasonable to assume that the effects of memantine as adjunctive therapy on negative symptoms and cognitive deficits in schizophrenia may derive primarily, if not totally, from its NMDA receptor antagonist activity at NMDA receptors including extrasynaptic receptors in the CNS.
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Affiliation(s)
- Tetsuro Kikuchi
- New Drug Research Division, Pharmaceutical Business Division, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, Tokushima 771-0192, Japan
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25
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Aizenman E, Loring RH, Reynolds IJ, Rosenberg PA. The Redox Biology of Excitotoxic Processes: The NMDA Receptor, TOPA Quinone, and the Oxidative Liberation of Intracellular Zinc. Front Neurosci 2020; 14:778. [PMID: 32792905 PMCID: PMC7393236 DOI: 10.3389/fnins.2020.00778] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022] Open
Abstract
This special issue of Frontiers in Neuroscience-Neurodegeneration celebrates the 50th anniversary of John Olney's seminal work introducing the concept of excitotoxicity as a mechanism for neuronal cell death. Since that time, fundamental research on the pathophysiological activation of glutamate receptors has played a central role in our understanding of excitotoxic cellular signaling pathways, leading to the discovery of many potential therapeutic targets in the treatment of acute or chronic/progressive neurodegenerative disorders. Importantly, excitotoxic signaling processes have been found repeatedly to be closely intertwined with oxidative cellular cascades. With this in mind, this review looks back at long-standing collaborative efforts by the authors linking cellular redox status and glutamate neurotoxicity, focusing first on the discovery of the redox modulatory site of the N-methyl-D-aspartate (NMDA) receptor, followed by the study of the oxidative conversion of 3,4-dihydroxyphenylalanine (DOPA) to the non-NMDA receptor agonist and neurotoxin 2,4,5-trihydroxyphenylalanine (TOPA) quinone. Finally, we summarize our work linking oxidative injury to the liberation of zinc from intracellular metal binding proteins, leading to the uncovering of a signaling mechanism connecting excitotoxicity with zinc-activated cell death-signaling cascades.
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Affiliation(s)
- Elias Aizenman
- Department of Neurobiology, Pittsburgh Institute for Neurodegenerative Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ralph H. Loring
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA, United States
| | | | - Paul A. Rosenberg
- Program in Neuroscience, F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
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26
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Shen W, Ren W, Zhai S, Yang B, Vanoye CG, Mitra A, George AL, Surmeier DJ. Striatal Kir2 K+ channel inhibition mediates the antidyskinetic effects of amantadine. J Clin Invest 2020; 130:2593-2601. [PMID: 32310223 PMCID: PMC7190977 DOI: 10.1172/jci133398] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/06/2020] [Indexed: 11/17/2022] Open
Abstract
Levodopa-induced dyskinesia (LID) poses a significant health care challenge for Parkinson's disease (PD) patients. Amantadine is currently the only drug proven to alleviate LID. Although its efficacy in treating LID is widely assumed to be mediated by blockade of N-methyl-D-aspartate (NMDA) glutamate receptors, our experiments demonstrate that at therapeutically relevant concentrations, amantadine preferentially blocks inward-rectifying K+ channel type 2 (Kir2) channels in striatal spiny projection neurons (SPNs) - not NMDA receptors. In so doing, amantadine enhances dendritic integration of excitatory synaptic potentials in SPNs and enhances - not antagonizes - the induction of long-term potentiation (LTP) at excitatory, axospinous synapses. Taken together, our studies suggest that the alleviation of LID in PD patients is mediated by diminishing the disparity in the excitability of direct- and indirect-pathway SPNs in the on state, rather than by disrupting LTP induction. This insight points to a pharmacological approach that could be used to effectively ameliorate LID and improve the quality of life for PD patients.
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Affiliation(s)
| | | | | | | | - Carlos G. Vanoye
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ananya Mitra
- Adamas Pharmaceuticals, Inc., Emeryville, California, USA
| | - Alfred L. George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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27
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Dual action of amitriptyline on NMDA receptors: enhancement of Ca-dependent desensitization and trapping channel block. Sci Rep 2019; 9:19454. [PMID: 31857688 PMCID: PMC6923474 DOI: 10.1038/s41598-019-56072-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 12/04/2019] [Indexed: 12/18/2022] Open
Abstract
Although the tricyclic antidepressant amitriptyline (ATL) is widely used in the clinic, the mechanism underlying its high therapeutic efficacy against neuropathic pain remains unclear. NMDA receptors (NMDARs) represent a target for ATL and are involved in sensitization of neuropathic pain. Here we describe two actions of ATL on NMDARs: 1) enhancement of Ca2+-dependent desensitization and 2) trapping channel block. Inhibition of NMDARs by ATL was found to be dependent upon external Ca2+ concentration ([Ca2+]) in a voltage-independent manner, with an IC50 of 0.72 μM in 4 mM [Ca2+]. The ATL IC50 value increased exponentially with decreasing [Ca2+], with an e-fold change observed per 0.69 mM decrease in [Ca2+]. Loading neurons with BAPTA abolished Ca2+-dependent inhibition, suggesting that Ca2+ affects NMDARs from the cytosol. Since there is one known Ca2+-dependent process in gating of NMDARs, we conclude that ATL most likely promotes Ca2+-dependent desensitization. We also found ATL to be a trapping open-channel blocker of NMDARs with an IC50 of 220 µM at 0 mV. An e-fold change in ATL IC50 was observed to occur with a voltage shift of 50 mV in 0.25 mM [Ca2+]. Thus, we disclose here a robust dependence of ATL potency on extracellular [Ca2+], and demonstrate that ATL bound in the NMDAR pore can be trapped by closure of the channel.
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28
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Duman RS, Shinohara R, Fogaça MV, Hare B. Neurobiology of rapid-acting antidepressants: convergent effects on GluA1-synaptic function. Mol Psychiatry 2019; 24:1816-1832. [PMID: 30894661 PMCID: PMC6754322 DOI: 10.1038/s41380-019-0400-x] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/22/2019] [Accepted: 03/05/2019] [Indexed: 11/09/2022]
Abstract
Efforts to develop efficacious antidepressant agents with novel mechanisms have been largely unsuccessful since the 1950's until the discovery of ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist that produces rapid and sustained antidepressant actions even in treatment-resistant patients. This finding has ushered in a new era for the development of novel rapid-acting antidepressants that act at the NMDA receptor complex, but without dissociative and psychotomimetic side effects of ketamine. Here, we review the current state of rapid-acting antidepressant drug development, including NMDA channel blockers, glycine site agents, and allosteric modulators, as well as ketamine stereoisomers and metabolites. In addition, we focus on the neurobiological mechanisms underlying the actions of these diverse agents and discuss evidence of convergent mechanisms including increased brain-derived neurotrophic factor signaling, increased synthesis of synaptic proteins, and most notably increased GluR1 and synaptic connectivity in the medial prefrontal cortex. These convergent mechanisms provide insight for potential additional novel targets for drug development (e.g., agents that increase synaptic protein synthesis and plasticity). Importantly, the convergent effects on synapse formation and plasticity also reverse the well-documented neuronal and synaptic deficits associated with stress and depression, and thereby target the underlying pathophysiology of major depressive disorder.
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Affiliation(s)
- Ronald S Duman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
| | - Ryota Shinohara
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Manoela V Fogaça
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Brendan Hare
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
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29
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Bera K, Kamajaya A, Shivange AV, Muthusamy AK, Nichols AL, Borden PM, Grant S, Jeon J, Lin E, Bishara I, Chin TM, Cohen BN, Kim CH, Unger EK, Tian L, Marvin JS, Looger LL, Lester HA. Biosensors Show the Pharmacokinetics of S-Ketamine in the Endoplasmic Reticulum. Front Cell Neurosci 2019; 13:499. [PMID: 31798415 PMCID: PMC6874132 DOI: 10.3389/fncel.2019.00499] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/22/2019] [Indexed: 12/20/2022] Open
Abstract
The target for the “rapid” (<24 h) antidepressant effects of S-ketamine is unknown, vitiating programs to rationally develop more effective rapid antidepressants. To describe a drug’s target, one must first understand the compartments entered by the drug, at all levels—the organ, the cell, and the organelle. We have, therefore, developed molecular tools to measure the subcellular, organellar pharmacokinetics of S-ketamine. The tools are genetically encoded intensity-based S-ketamine-sensing fluorescent reporters, iSKetSnFR1 and iSKetSnFR2. In solution, these biosensors respond to S-ketamine with a sensitivity, S-slope = delta(F/F0)/(delta[S-ketamine]) of 0.23 and 1.9/μM, respectively. The iSKetSnFR2 construct allows measurements at <0.3 μM S-ketamine. The iSKetSnFR1 and iSKetSnFR2 biosensors display >100-fold selectivity over other ligands tested, including R-ketamine. We targeted each of the sensors to either the plasma membrane (PM) or the endoplasmic reticulum (ER). Measurements on these biosensors expressed in Neuro2a cells and in human dopaminergic neurons differentiated from induced pluripotent stem cells (iPSCs) show that S-ketamine enters the ER within a few seconds after appearing in the external solution near the PM, then leaves as rapidly after S-ketamine is removed from the extracellular solution. In cells, S-slopes for the ER and PM-targeted sensors differ by <2-fold, indicating that the ER [S-ketamine] is less than 2-fold different from the extracellular [S-ketamine]. Organelles represent potential compartments for the engagement of S-ketamine with its antidepressant target, and potential S-ketamine targets include organellar ion channels, receptors, and transporters.
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Affiliation(s)
- Kallol Bera
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Aron Kamajaya
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Amol V Shivange
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Anand K Muthusamy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Aaron L Nichols
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Philip M Borden
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, United States
| | - Stephen Grant
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Janice Jeon
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Elaine Lin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Ishak Bishara
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Theodore M Chin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Bruce N Cohen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Charlene H Kim
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Elizabeth K Unger
- Department of Biochemistry and Molecular Medicine, University of California, Davis, Davis, CA, United States
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, University of California, Davis, Davis, CA, United States
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, United States
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, United States
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
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30
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Dron MY, Zhigulin AS, Barygin OI. Mechanisms of NMDA receptor inhibition by diarylamidine compounds. Eur J Neurosci 2019; 51:1573-1582. [PMID: 31605636 DOI: 10.1111/ejn.14589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 09/30/2019] [Accepted: 10/04/2019] [Indexed: 12/19/2022]
Abstract
Pentamidine, diminazene and 4',6-diamidino-2-phenylindole (DAPI) are antiprotozoal diarylamidine compounds. In the present work, we have studied their action on native N-methyl-D-aspartate (NMDA) receptors in rat hippocampal pyramidal neurons. All three compounds inhibited NMDA receptors at -80 mV holding voltage with IC50 of 0.41 ± 0.08, 13 ± 3 and 3.1 ± 0.6 μM, respectively. The inhibition by pentamidine was strongly voltage-dependent, while that of DAPI was practically voltage-independent. Inhibition by diminazene had both voltage-dependent and voltage-independent components. Diminazene and DAPI demonstrated tail currents and overshoots suggesting "foot-in-the-door" mechanism of action. In contrast, pentamidine was partially trapped in the closed NMDA receptor channels. Such difference in the mechanism of action can be explained by the difference in the 3D structure of compounds. In the pentamidine molecule, two benzamidine groups are connected with a flexible linker, which allows the molecule to fold up and fit in the cavity of a closed NMDA receptor channel. Diminazene and DAPI, in contrast, have an extended form and could not be trapped.
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Affiliation(s)
- Mikhail Y Dron
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - Arseniy S Zhigulin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
| | - Oleg I Barygin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint-Petersburg, Russia
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31
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Nakazawa K, Sapkota K. The origin of NMDA receptor hypofunction in schizophrenia. Pharmacol Ther 2019; 205:107426. [PMID: 31629007 DOI: 10.1016/j.pharmthera.2019.107426] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/10/2019] [Indexed: 12/12/2022]
Abstract
N-methyl-d-aspartate (NMDA) receptor (NMDAR) hypofunction plays a key role in pathophysiology of schizophrenia. Since NMDAR hypofunction has also been reported in autism, Alzheimer's disease and cognitive dementia, it is crucial to identify the location, timing, and mechanism of NMDAR hypofunction for schizophrenia for better understanding of disease etiology and for novel therapeutic intervention. In this review, we first discuss the shared underlying mechanisms of NMDAR hypofunction in NMDAR antagonist models and the anti-NMDAR autoantibody model of schizophrenia and suggest that NMDAR hypofunction could occur in GABAergic neurons in both models. Preclinical models using transgenic mice have shown that NMDAR hypofunction in cortical GABAergic neurons, in particular parvalbumin-positive fast-spiking interneurons, in the early postnatal period confers schizophrenia-related phenotypes. Recent studies suggest that NMDAR hypofunction can also occur in PV-positive GABAergic neurons with alterations of NMDAR-associated proteins, such as neuregulin/ErbB4, α7nAChR, and serine racemase. Furthermore, several environmental factors, such as oxidative stress, kynurenic acid and hypoxia, may also potentially elicit NMDAR hypofunction in GABAergic neurons in early postnatal period. Altogether, the studies discussed here support a central role for GABAergic abnormalities in the context of NMDAR hypofunction. We conclude by suggesting potential therapeutic strategies to improve the function of fast-spiking neurons.
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Leiva R, Phillips MB, Turcu AL, Gratacòs-Batlle E, León-García L, Sureda FX, Soto D, Johnson JW, Vázquez S. Pharmacological and Electrophysiological Characterization of Novel NMDA Receptor Antagonists. ACS Chem Neurosci 2018; 9:2722-2730. [PMID: 29767953 DOI: 10.1021/acschemneuro.8b00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This work reports the synthesis and pharmacological and electrophysiological evaluation of new N-methyl-d-aspartic acid receptor (NMDAR) channel blocking antagonists featuring polycyclic scaffolds. Changes in the chemical structure modulate the potency and voltage dependence of inhibition. Two of the new antagonists display properties comparable to those of memantine, a clinically approved NMDAR antagonist.
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Affiliation(s)
- Rosana Leiva
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia i Ciències de l’Alimentació i Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, 08028 Barcelona, Spain
| | - Matthew B. Phillips
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Andreea L. Turcu
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia i Ciències de l’Alimentació i Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, 08028 Barcelona, Spain
- Neurophysiology Laboratory, Physiology Unit, Department of Biomedicine, Medical School Universitat de Barcelona, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, and Institut of Neurosciences, 08036 Barcelona, Spain
| | - Esther Gratacòs-Batlle
- Neurophysiology Laboratory, Physiology Unit, Department of Biomedicine, Medical School Universitat de Barcelona, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, and Institut of Neurosciences, 08036 Barcelona, Spain
| | - Lara León-García
- Pharmacology Unit, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C./St. Llorenç 21, 43201 Reus, Tarragona, Spain
| | - Francesc X. Sureda
- Pharmacology Unit, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C./St. Llorenç 21, 43201 Reus, Tarragona, Spain
| | - David Soto
- Neurophysiology Laboratory, Physiology Unit, Department of Biomedicine, Medical School Universitat de Barcelona, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, and Institut of Neurosciences, 08036 Barcelona, Spain
| | - Jon W. Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Santiago Vázquez
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia i Ciències de l’Alimentació i Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, 08028 Barcelona, Spain
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Kaniakova M, Kleteckova L, Lichnerova K, Holubova K, Skrenkova K, Korinek M, Krusek J, Smejkalova T, Korabecny J, Vales K, Soukup O, Horak M. 7-Methoxyderivative of tacrine is a ‘foot-in-the-door’ open-channel blocker of GluN1/GluN2 and GluN1/GluN3 NMDA receptors with neuroprotective activity in vivo. Neuropharmacology 2018; 140:217-232. [DOI: 10.1016/j.neuropharm.2018.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/17/2018] [Accepted: 08/07/2018] [Indexed: 10/28/2022]
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Morrison A, Houtrow A, Zullo J, Kochanek P, Vetterly C, Fink E. Neurostimulant Prescribing Patterns in Children Admitted to the Intensive Care Unit after Traumatic Brain Injury. J Neurotrauma 2018; 36:293-299. [PMID: 29756534 DOI: 10.1089/neu.2017.5575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neurostimulant medications are commonly prescribed following traumatic brain injury (TBI) in adults; little is known about their use in children with TBI. Our objective was to analyze neurostimulant prescribing practices from 2005 to 2015 in children admitted to the intensive care unit (ICU) with TBI. We hypothesized that neurostimulant prescriptions have increased over time and are associated with older age and injury severity. A retrospective cohort study of patients age 1 month to 18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis code for TBI admitted to the ICU between 2005 and 2015 in 37 pediatric hospitals included in the Pediatric Health Information System was conducted. Variables examined include patient and injury characteristics and neurostimulant medication use. Descriptive statistics and multi-variable logistic regression testing were used to determine variables associated with neurostimulant prescription. Of 30,881 patients with TBI, most were male (64%) and age 0-4 years (43%). In patients with mechanism of injury reported (n = 21,998), TBI was most frequently due to falls (36%) and motor vehicle collisions (36%). One thousand sixty-four neurostimulants were prescribed to 878 (3%) patients with 41% of prescriptions for amantadine and 38% for methylphenidate. Neurostimulants were prescribed a median (interquartile range) of 17 (8-35) days post-injury and increased over the study decade (R2 = 0.806). In a multi-variable analysis, variables most strongly associated with receipt of a neurostimulant were age 14-18 years (odds ratio 5.8, 95% confidence interval [4.3,7.8]), motor vehicle collision (3.1, [2.4,4.2]), intracranial pressure (ICP) monitor (3.8, [3.1,4.5]), and mechanical ventilation (3.4, [2.7,4.3]). Use of neurostimulants following pediatric TBI is uncommon, has increased over time, and is associated with indicators of higher severity of illness. Knowledge of prescribing practices may assist in optimizing the design of efficacy and outcome studies that will inform clinical guidelines.
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Affiliation(s)
- Amanda Morrison
- 1 University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Amy Houtrow
- 2 Department of Physical Medicine and Rehabilitation, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Jim Zullo
- 3 CHP-Data Warehouse, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Patrick Kochanek
- 4 Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Carol Vetterly
- 5 Pharmacy Services, Pediatric Critical Care, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Ericka Fink
- 6 Division of Pediatric Critical Care Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
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35
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Hansen KB, Yi F, Perszyk RE, Furukawa H, Wollmuth LP, Gibb AJ, Traynelis SF. Structure, function, and allosteric modulation of NMDA receptors. J Gen Physiol 2018; 150:1081-1105. [PMID: 30037851 PMCID: PMC6080888 DOI: 10.1085/jgp.201812032] [Citation(s) in RCA: 315] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022] Open
Abstract
Hansen et al. review recent structural data that have provided insight into the function and allosteric modulation of NMDA receptors. NMDA-type glutamate receptors are ligand-gated ion channels that mediate a Ca2+-permeable component of excitatory neurotransmission in the central nervous system (CNS). They are expressed throughout the CNS and play key physiological roles in synaptic function, such as synaptic plasticity, learning, and memory. NMDA receptors are also implicated in the pathophysiology of several CNS disorders and more recently have been identified as a locus for disease-associated genomic variation. NMDA receptors exist as a diverse array of subtypes formed by variation in assembly of seven subunits (GluN1, GluN2A-D, and GluN3A-B) into tetrameric receptor complexes. These NMDA receptor subtypes show unique structural features that account for their distinct functional and pharmacological properties allowing precise tuning of their physiological roles. Here, we review the relationship between NMDA receptor structure and function with an emphasis on emerging atomic resolution structures, which begin to explain unique features of this receptor.
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Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
| | - Hiro Furukawa
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Lonnie P Wollmuth
- Departments of Neurobiology & Behavior and Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY
| | - Alasdair J Gibb
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
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Glasgow NG, Wilcox MR, Johnson JW. Effects of Mg 2+ on recovery of NMDA receptors from inhibition by memantine and ketamine reveal properties of a second site. Neuropharmacology 2018; 137:344-358. [PMID: 29793153 PMCID: PMC6050087 DOI: 10.1016/j.neuropharm.2018.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/18/2018] [Accepted: 05/11/2018] [Indexed: 01/19/2023]
Abstract
Memantine and ketamine are NMDA receptor (NMDAR) open channel blockers that are thought to act via similar mechanisms at NMDARs, but exhibit divergent clinical effects. Both drugs act by entering open NMDARs and binding at a site deep within the ion channel (the deep site) at which the endogenous NMDAR channel blocker Mg2+ also binds. Under physiological conditions, Mg2+ increases the IC50s of memantine and ketamine through competition for binding at the deep site. Memantine also can inhibit NMDARs after associating with a second site accessible in the absence of agonist, a process termed second site inhibition (SSI) that is not observed with ketamine. Here we investigated the effects of 1 mM Mg2+ on recovery from inhibition by memantine and ketamine, and on memantine SSI, of the four main diheteromeric NMDAR subtypes. We found that: recovery from memantine inhibition depended strongly on the concentration of memantine used to inhibit the NMDAR response; Mg2+ accelerated recovery from memantine and ketamine inhibition through distinct mechanisms and in an NMDAR subtype-dependent manner; and Mg2+ occupation of the deep site disrupted memantine SSI in a subtype-dependent manner. Our results support the hypothesis that memantine associates with, but does not inhibit at the second site. After associating with the second site, memantine can either slowly dissociate directly to the extracellular solution, or transit to the deep site, resulting in typical channel block. Memantine's relatively slow dissociation from the second site underlies the dependence of NMDAR recovery from inhibition on both memantine concentration and on Mg2+.
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Affiliation(s)
- Nathan G Glasgow
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Madeleine R Wilcox
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jon W Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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37
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Fedele L, Newcombe J, Topf M, Gibb A, Harvey RJ, Smart TG. Disease-associated missense mutations in GluN2B subunit alter NMDA receptor ligand binding and ion channel properties. Nat Commun 2018; 9:957. [PMID: 29511171 PMCID: PMC5840332 DOI: 10.1038/s41467-018-02927-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 01/08/2018] [Indexed: 11/09/2022] Open
Abstract
Genetic and bioinformatic analyses have identified missense mutations in GRIN2B encoding the NMDA receptor GluN2B subunit in autism, intellectual disability, Lennox Gastaut and West Syndromes. Here, we investigated several such mutations using a near-complete, hybrid 3D model of the human NMDAR and studied their consequences with kinetic modelling and electrophysiology. The mutants revealed reductions in glutamate potency; increased receptor desensitisation; and ablation of voltage-dependent Mg2+ block. In addition, we provide new views on Mg2+ and NMDA channel blocker binding sites. We demonstrate that these mutants have significant impact on excitatory transmission in developing neurons, revealing profound changes that could underlie their associated neurological disorders. Of note, the NMDAR channel mutant GluN2BV618G unusually allowed Mg2+ permeation, whereas nearby N615I reduced Ca2+ permeability. By identifying the binding site for an NMDAR antagonist that is used in the clinic to rescue gain-of-function phenotypes, we show that drug binding may be modified by some GluN2B disease-causing mutations.
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Affiliation(s)
- Laura Fedele
- Department of Pharmacology, UCL School of Pharmacy Brunswick Square, London, WC1N 1AX, UK
- Department of Neuroscience, Physiology & Pharmacology UCL, Gower Street, London, WC1E 6BT, UK
| | - Joseph Newcombe
- Department of Biological Sciences, Birkbeck College, University of London, London, WC1E 7HX, UK
| | - Maya Topf
- Department of Biological Sciences, Birkbeck College, University of London, London, WC1E 7HX, UK
| | - Alasdair Gibb
- Department of Neuroscience, Physiology & Pharmacology UCL, Gower Street, London, WC1E 6BT, UK
| | - Robert J Harvey
- School of Health and Sport Sciences, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD 4556, Australia.
- Sunshine Coast Health Institute, 6 Doherty Street, Birtinya, QLD 4575, Australia.
| | - Trevor G Smart
- Department of Neuroscience, Physiology & Pharmacology UCL, Gower Street, London, WC1E 6BT, UK.
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38
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Schoenberger M, Schroeder FA, Placzek MS, Carter RL, Rosen BR, Hooker JM, Sander CY. In Vivo [ 18F]GE-179 Brain Signal Does Not Show NMDA-Specific Modulation with Drug Challenges in Rodents and Nonhuman Primates. ACS Chem Neurosci 2018; 9:298-305. [PMID: 29050469 DOI: 10.1021/acschemneuro.7b00327] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
As one of the major excitatory ion channels in the brain, NMDA receptors have been a leading research target for neuroscientists, physicians, medicinal chemists, and pharmaceutical companies for decades. Molecular imaging of NMDA receptors by means of positron emission tomography (PET) with [18F]GE-179 quickly progressed to clinical PET studies, but a thorough understanding of its binding specificity has been missing and has thus limited signal interpretation. Here a preclinical study with [18F]GE-179 in rodents and nonhuman primates (NHPs) is presented in an attempt to characterize [18F]GE-179 signal specificity. Rodent PET/CT was used to study drug occupancy and functional manipulation in rats by pretreating animals with NMDA targeted blocking/modulating drug doses followed by a single bolus of [18F]GE-179. Binding competition with GE-179, MK801, PCP, and ketamine, allosteric inhibition by ifenprodil, and brain activation with methamphetamine did not alter the [18F]GE-179 brain signal in rats. In addition, multimodal imaging with PET/MRI in NHPs was used to evaluate changes in radiotracer binding as a function of pharmacological challenges. Drug-induced hemodynamic changes were monitored simultaneously using functional MRI (fMRI). Comparisons of baseline and signal after drug challenge in NHPs demonstrated that the [18F]GE-179 signal cannot be manipulated in a predictable fashion in vivo. fMRI data acquired simultaneously with PET data supported this finding and provided evidence that radiotracer delivery is not altered by blood flow changes. In conclusion, the [18F]GE-179 brain signal is not readily interpretable in the context of NMDA receptor binding on the basis of the results shown in this study.
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Affiliation(s)
- Matthias Schoenberger
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Chemical Biology and Imaging, Department of Pharmaceutical and Pharmacological
Sciences, KU Leuven, BE-3000 Leuven, Belgium
| | - Frederick A. Schroeder
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Michael S. Placzek
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Department of Psychiatry, McLean Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, United States
- Harvard Medical School, Boston, Massachusetts 02115, United States
| | | | - Bruce R. Rosen
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Harvard-MIT Division of Health Sciences
and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jacob M. Hooker
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Christin Y. Sander
- Athinoula A. Martinos
Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Harvard Medical School, Boston, Massachusetts 02115, United States
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39
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Aleksandrova LR, Wang YT, Phillips AG. Hydroxynorketamine: Implications for the NMDA Receptor Hypothesis of Ketamine's Antidepressant Action. CHRONIC STRESS 2017; 1. [PMID: 30556028 PMCID: PMC6292673 DOI: 10.1177/2470547017743511] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The prevailing hypothesis of ketamine’s unique antidepressant effects implicates
N-methyl-d-aspartate receptor (NMDAR) inhibition-dependent enhancement of
α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated
transmission, activation of intracellular signalling pathways and increased
synaptogenesis. Recently, however, a seminal study by Zanos et al. directly
challenged the NMDAR hypothesis of ketamine with the claim that an active
ketamine metabolite, (2R,6R)-hydroxynorketamine, devoid of NMDAR binding
properties or key side effects of its parent compound, is both necessary and
sufficient for ketamine’s antidepressant effects in rodents. However, following
these encouraging initial findings, one preclinical study failed to replicate
the antidepressant effects of (2R,6R)-hydroxynorketamine (HNK), while others
have questioned the metabolite’s contribution to ketamine’s therapeutic effects
or argued against rejecting the NMDAR hypothesis of ketamine action. In light of
these potentially paradigm-shifting, but highly controversial, findings, this
review will summarise and critically evaluate the evidence for and against the
NMDA receptor hypothesis of ketamine action, with a particular focus on
(2R,6R)-HNK and the implications of its discovery for understanding ketamine’s
mechanism of action in depression. Ultimately, uncovering the molecular
mechanisms underlying the therapeutic effects of ketamine and possibly
(2R,6R)-HNK, will aid the development of novel and more efficacious
antidepressant agents so urgently needed to address a major public health
concern, and could hold potential for the treatment of other stress-related
psychopathologies, including bipolar disorder, post-traumatic stress disorder
and suicidality.
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Affiliation(s)
- Lily R Aleksandrova
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.,Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Yu Tian Wang
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Anthony G Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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40
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Shteinikov VY, Tikhonova TB, Korkosh VS, Tikhonov DB. Potentiation and Block of ASIC1a by Memantine. Cell Mol Neurobiol 2017; 38:869-881. [PMID: 29058095 DOI: 10.1007/s10571-017-0561-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/17/2017] [Indexed: 01/02/2023]
Abstract
Acid-sensing ion channels (ASICs) are modulated by various classes of ligands, including the recently described hydrophobic monoamines, which inhibit and potentiate ASICs in a subunit-specific manner. In particular, memantine inhibits ASIC1a and potentiates ASIC2a homomers. The aim of the present work was to characterize action mechanism of memantine on recombinant ASIC1a expressed in CHO (Chinese hamster ovary) cells. We have demonstrated that effect of memantine on ASIC1a strongly depends on membrane voltage, conditioning pH value and application protocol. When applied simultaneously with activating acidification at hyperpolarized voltages, memantine caused the strongest inhibition. Surprisingly, application of memantine between ASIC1a activations at zero voltage caused significant potentiation. Analysis of the data suggests that memantine produces two separate effects, voltage-dependent open-channel block and shift of steady-state desensitization curve to more acidic values. Putative binding sites are discussed based on the computer docking of memantine to the acidic pocket and the pore region.
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Affiliation(s)
- Vasiliy Y Shteinikov
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 44 Thorez pr., St.Petersburg, Russia
| | - Tatiana B Tikhonova
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 44 Thorez pr., St.Petersburg, Russia
| | - Vyacheslav S Korkosh
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 44 Thorez pr., St.Petersburg, Russia
| | - Denis B Tikhonov
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 44 Thorez pr., St.Petersburg, Russia.
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41
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Lorenz-Guertin JM, Wilcox MR, Zhang M, Larsen MB, Pilli J, Schmidt BF, Bruchez MP, Johnson JW, Waggoner AS, Watkins SC, Jacob TC. A versatile optical tool for studying synaptic GABA A receptor trafficking. J Cell Sci 2017; 130:3933-3945. [PMID: 29025969 DOI: 10.1242/jcs.205286] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/26/2017] [Indexed: 12/26/2022] Open
Abstract
Live-cell imaging methods can provide critical real-time receptor trafficking measurements. Here, we describe an optical tool to study synaptic γ-aminobutyric acid (GABA) type A receptor (GABAAR) dynamics through adaptable fluorescent-tracking capabilities. A fluorogen-activating peptide (FAP) was genetically inserted into a GABAAR γ2 subunit tagged with pH-sensitive green fluorescent protein (γ2pHFAP). The FAP selectively binds and activates Malachite Green (MG) dyes that are otherwise non-fluorescent in solution. γ2pHFAP GABAARs are expressed at the cell surface in transfected cortical neurons, form synaptic clusters and do not perturb neuronal development. Electrophysiological studies show γ2pHFAP GABAARs respond to GABA and exhibit positive modulation upon stimulation with the benzodiazepine diazepam. Imaging studies using γ2pHFAP-transfected neurons and MG dyes show time-dependent receptor accumulation into intracellular vesicles, revealing constitutive endosomal and lysosomal trafficking. Simultaneous analysis of synaptic, surface and lysosomal receptors using the γ2pHFAP-MG dye approach reveals enhanced GABAAR turnover following a bicucculine-induced seizure paradigm, a finding not detected by standard surface receptor measurements. To our knowledge, this is the first application of the FAP-MG dye system in neurons, demonstrating the versatility to study nearly all phases of GABAAR trafficking.
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Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Madeleine R Wilcox
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Ming Zhang
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Mads B Larsen
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jyotsna Pilli
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Brigitte F Schmidt
- Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marcel P Bruchez
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Jon W Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alan S Waggoner
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Simon C Watkins
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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42
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The structure-energy landscape of NMDA receptor gating. Nat Chem Biol 2017; 13:1232-1238. [PMID: 28991238 PMCID: PMC5698143 DOI: 10.1038/nchembio.2487] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 08/28/2017] [Indexed: 01/26/2023]
Abstract
N-Methyl-D-aspartate (NMDA) receptors are the main calcium-permeable excitatory receptors in the mammalian central nervous system. The NMDA receptor gating is complex, exhibiting multiple closed, open, and desensitized states; however, central questions regarding the conformations and energetics of the transmembrane domains as they relate to the gating states are still unanswered. Here, using single-molecule Förster resonance energy transfer (smFRET), we map the energy landscape of the first transmembrane segment of the Rattus norvegicus NMDA receptor under resting and various liganded conditions. These results show kinetically and structurally distinct changes associated with apo, agonist-bound, and inhibited receptors linked by a linear mechanism of gating at this site. Furthermore, the smFRET data suggest that allosteric inhibition by zinc occurs by an uncoupling of the agonist-induced changes at the extracellular domains from the gating motions leading to an apo-like state, while dizocilpine, a pore blocker, stabilizes multiple closely packed transmembrane states.
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Memantine and Ketamine Differentially Alter NMDA Receptor Desensitization. J Neurosci 2017; 37:9686-9704. [PMID: 28877967 DOI: 10.1523/jneurosci.1173-17.2017] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 08/07/2017] [Accepted: 08/30/2017] [Indexed: 11/21/2022] Open
Abstract
Memantine and ketamine are clinically useful NMDA receptor (NMDAR) open channel blockers that inhibit NMDARs with similar potency and kinetics, but display vastly different clinical profiles. This discrepancy has been hypothesized to result from inhibition by memantine and ketamine of overlapping but distinct NMDAR subpopulations. For example, memantine but not ketamine may inhibit extrasynaptic NMDARs more effectively than synaptic NMDARs. However, the basis for preferential NMDAR inhibition depending on subcellular location has not been investigated systematically. We integrated recordings from heterologously expressed single NMDAR subtypes, kinetic modeling, and recordings of synaptically evoked NMDAR responses in acute brain slices to investigate mechanisms by which channel blockers may distinguish NMDAR subpopulations. We found that memantine and ketamine differentially alter NMDAR desensitization and that memantine stabilizes a Ca2+-dependent desensitized state. As a result, inhibition by memantine of GluN1/2A receptors in tsA201 cells and of native synaptic NMDARs in cortical pyramidal neurons from mice of either sex increased in conditions that enhanced intracellular Ca2+ accumulation. Therefore, differential inhibition by memantine and ketamine based on NMDAR location is likely to result from location dependence of the intensity and duration of NMDAR activation. Modulation of Ca2+-dependent NMDAR desensitization is an unexplored mechanism of inhibitory action with the potential to endow drugs with NMDAR selectivity that leads to superior clinical profiles. Our results suggest that designing compounds to target specific receptor states, rather than specific receptor types, may be a viable strategy for future drug development.SIGNIFICANCE STATEMENT Memantine and ketamine are NMDA receptor (NMDAR) channel-blocking drugs with divergent clinical effects. Understanding mechanistically their differential actions may advance our understanding of nervous system disorders and suggest strategies for the design of more effective drugs. Here, we show that memantine and ketamine have contrasting effects on NMDAR desensitization. Ketamine binding decreases occupancy of desensitized states of the GluN1/2B NMDAR subtype. In contrast, memantine binding increases occupancy of GluN1/2A and native NMDAR desensitized states entered after accumulation of intracellular Ca2+, a novel inhibitory mechanism. These properties may contribute to inhibition of distinct NMDAR subpopulations by memantine and ketamine and help to explain their differential clinical effects. Our results suggest stabilization of Ca2+-dependent desensitized states as a new strategy for pharmaceutical neuroprotection.
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Gao K, Tankovic A, Zhang Y, Kusumoto H, Zhang J, Chen W, XiangWei W, Shaulsky GH, Hu C, Traynelis SF, Yuan H, Jiang Y. A de novo loss-of-function GRIN2A mutation associated with childhood focal epilepsy and acquired epileptic aphasia. PLoS One 2017; 12:e0170818. [PMID: 28182669 PMCID: PMC5300259 DOI: 10.1371/journal.pone.0170818] [Citation(s) in RCA: 40] [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: 10/08/2016] [Accepted: 01/11/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE N-methyl-D-aspartate receptors (NMDAR) subunit GRIN2A/GluN2A mutations have been identified in patients with various neurological diseases, such as epilepsy and intellectual disability / developmental delay (ID/DD). In this study, we investigated the phenotype and underlying molecular mechanism of a GRIN2A missense mutation identified by next generation sequencing on idiopathic focal epilepsy using in vitro electrophysiology. METHODS Genomic DNA of patients with epilepsy and ID/DD were sequenced by targeted next-generation sequencing within 300 genes related to epilepsy and ID/DD. The effects of one missense GRIN2A mutation on NMDAR function were evaluated by two-electrode voltage clamp current recordings and whole cell voltage clamp current recordings. RESULTS We identified one de novo missense GRIN2A mutation (Asp731Asn, GluN2A(D731N)) in a child with unexplained epilepsy and DD. The D731N mutation is located in a portion of the agonist-binding domain (ABD) in the GluN2A subunit, which is the binding pocket for agonist glutamate. This residue in the ABD is conserved among vertebrate species and all other NMDAR subunits, suggesting an important role in receptor function. The proband shows developmental delay as well as EEG-confirmed seizure activity. Functional analyses reveal that the GluN2A(D731N) mutation decreases glutamate potency by over 3,000-fold, reduces amplitude of current response, shortens synaptic-like response time course, and decreases channel open probability, while enhancing sensitivity to negative allosteric modulators, including extracellular proton and zinc inhibition. The combined effects reduce NMDAR function. SIGNIFICANCE We identified a de novo missense mutation in the GRIN2A gene in a patient with childhood focal epilepsy and acquired epileptic aphasia. The mutant decreases NMDAR activation suggesting NMDAR hypofunction may contribute to the epilepsy pathogenesis.
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Affiliation(s)
- Kai Gao
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Anel Tankovic
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Yujia Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Hirofumi Kusumoto
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Jin Zhang
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Wenjuan Chen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Wenshu XiangWei
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Gil H. Shaulsky
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Chun Hu
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Stephen F. Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
- Center for Functional Evaluation of Rare Variant (CFERV), Emory University School of Medicine, Atlanta, GA, United States of America
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, United States of America
- Center for Functional Evaluation of Rare Variant (CFERV), Emory University School of Medicine, Atlanta, GA, United States of America
| | - Yuwu Jiang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease, characterized by the loss of memory, multiple cognitive impairments and changes in the personality and behavior. Several decades of intense research have revealed that multiple cellular changes are involved in disease process, including synaptic damage, mitochondrial abnormalities and inflammatory responses, in addition to formation and accumulation of amyloid-β (Aβ) and phosphorylated tau. Although tremendous progress has been made in understanding the impact of neurotransmitters in the progression and pathogenesis of AD, we still do not have a drug molecule associated with neurotransmitter(s) that can delay disease process in elderly individuals and/or restore cognitive functions in AD patients. The purpose of our article is to assess the latest developments in neurotransmitters research using cell and mouse models of AD. We also updated the current status of clinical trials using neurotransmitters' agonists/antagonists in AD.
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Affiliation(s)
- Ramesh Kandimalla
- Garrison Institute on Aging Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Pharmacology & Neuroscience Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P. Hemachandra Reddy
- Garrison Institute on Aging Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Pharmacology & Neuroscience Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Cell Biology & Biochemistry Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Neurology Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Garrison Institute on Aging, South West Campus, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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Hansen KB, Yi F, Perszyk RE, Menniti FS, Traynelis SF. NMDA Receptors in the Central Nervous System. Methods Mol Biol 2017; 1677:1-80. [PMID: 28986865 DOI: 10.1007/978-1-4939-7321-7_1] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
NMDA-type glutamate receptors are ligand-gated ion channels that mediate a major component of excitatory neurotransmission in the central nervous system (CNS). They are widely distributed at all stages of development and are critically involved in normal brain functions, including neuronal development and synaptic plasticity. NMDA receptors are also implicated in the pathophysiology of numerous neurological and psychiatric disorders, such as ischemic stroke, traumatic brain injury, Alzheimer's disease, epilepsy, mood disorders, and schizophrenia. For these reasons, NMDA receptors have been intensively studied in the past several decades to elucidate their physiological roles and to advance them as therapeutic targets. Seven NMDA receptor subunits exist that assemble into a diverse array of tetrameric receptor complexes, which are differently regulated, have distinct regional and developmental expression, and possess a wide range of functional and pharmacological properties. The diversity in subunit composition creates NMDA receptor subtypes with distinct physiological roles across neuronal cell types and brain regions, and enables precise tuning of synaptic transmission. Here, we will review the relationship between NMDA receptor structure and function, the diversity and significance of NMDA receptor subtypes in the CNS, as well as principles and rules by which NMDA receptors operate in the CNS under normal and pathological conditions.
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Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA. .,Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT, USA.
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Frank S Menniti
- MindImmune Therapeutics, Inc., George & Anne Ryan Institute for Neuroscience, Kingston, RI, USA
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
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Emnett C, Li H, Jiang X, Benz A, Boggiano J, Conyers S, Wozniak DF, Zorumski CF, Reichert DE, Mennerick S. A Clickable Analogue of Ketamine Retains NMDA Receptor Activity, Psychoactivity, and Accumulates in Neurons. Sci Rep 2016; 6:38808. [PMID: 27982047 PMCID: PMC5159840 DOI: 10.1038/srep38808] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/15/2016] [Indexed: 12/12/2022] Open
Abstract
Ketamine is a psychotomimetic and antidepressant drug. Although antagonism of cell-surface NMDA receptors (NMDARs) may trigger ketamine’s psychoactive effects, ketamine or its major metabolite norketamine could act intracellularly to produce some behavioral effects. To explore the viability of this latter hypothesis, we examined intracellular accumulation of novel visualizable analogues of ketamine/norketamine. We introduced an alkyne “click” handle into norketamine (alkyne-norketamine, A-NK) at the key nitrogen atom. Ketamine, norketamine, and A-NK, but not A-NK-amide, showed acute and persisting psychoactive effects in mice. This psychoactivity profile paralleled activity of the compounds as NMDAR channel blockers; A-NK-amide was inactive at NMDARs, and norketamine and A-NK were active but ~4-fold less potent than ketamine. We incubated rat hippocampal cells with 10 μM A-NK or A-NK-amide then performed Cu2+ catalyzed cycloaddition of azide-Alexa Fluor 488, which covalently attaches the fluorophore to the alkyne moiety in the compounds. Fluorescent imaging revealed intracellular localization of A-NK but weak A-NK-amide labeling. Accumulation was not dependent on membrane potential, NMDAR expression, or NMDAR activity. Overall, the approach revealed a correlation among NMDAR activity, intracellular accumulation/retention, and behavioral effects. Thus, we advance first generation chemical biology tools to aid in the identification of ketamine targets.
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Affiliation(s)
- Christine Emnett
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Graduate Program in Neurosciences, Division of Biology and Biomedical Sciences, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Hairong Li
- Department of Radiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Xiaoping Jiang
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Ann Benz
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Joseph Boggiano
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Sara Conyers
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - David F Wozniak
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Charles F Zorumski
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Department of Neuroscience, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - David E Reichert
- Department of Radiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Steven Mennerick
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Department of Neuroscience, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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Preferential Inhibition of Tonically over Phasically Activated NMDA Receptors by Pregnane Derivatives. J Neurosci 2016; 36:2161-75. [PMID: 26888927 DOI: 10.1523/jneurosci.3181-15.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Postsynaptic N-methyl-d-aspartate receptors (NMDARs) phasically activated by presynaptically released glutamate are critical for synaptic transmission and plasticity. However, under pathological conditions, excessive activation of NMDARs by tonically increased ambient glutamate contributes to excitotoxicity associated with various acute and chronic neurological disorders. Here, using heterologously expressed GluN1/GluN2A and GluN1/GluN2B receptors and rat autaptic hippocampal microisland cultures, we show that pregnanolone sulfate inhibits NMDAR currents induced by a prolonged glutamate application with a higher potency than the NMDAR component of EPSCs. For synthetic pregnanolone derivatives substituted with a carboxylic acid moiety at the end of an aliphatic chain of varying length and attached to the steroid skeleton at C3, the difference in potency between tonic and phasic inhibition increased with the length of the residue. The steroid with the longest substituent, pregnanolone hemipimelate, had no effect on phasically activated receptors while inhibiting tonically activated receptors. In behavioral tests, pregnanolone hemipimelate showed neuroprotective activity without psychomimetic symptoms. These results provide insight into the influence of steroids on neuronal function and stress their potential use in the development of novel therapeutics with neuroprotective action. SIGNIFICANCE STATEMENT Synaptic activation of N-methyl-d-aspartate receptors (NMDARs) plays a key role in synaptic plasticity, but excessive tonic NMDAR activation mediates excitotoxicity associated with many neurological disorders. Therefore, there is much interest in pharmacological agents capable of selectively blocking tonically activated NMDARs while leaving synaptically activated NMDARs intact. Here, we show that an endogenous neurosteroid pregnanolone sulfate is more potent at inhibiting tonically than synaptically activated NMDARs. Further, we report that a novel synthetic analog of pregnanolone sulfate, pregnanolone hemipimelate, inhibits tonic NMDAR currents without inhibiting the NMDAR component of the EPSC and shows neuroprotective activity in vivo without inducing psychomimetic side effects. These results suggest steroids may have a clinical advantage over other known classes of NMDAR inhibitors.
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Doozandeh A, Yazdani S. Neuroprotection in Glaucoma. J Ophthalmic Vis Res 2016; 11:209-20. [PMID: 27413504 PMCID: PMC4926571 DOI: 10.4103/2008-322x.183923] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 08/03/2015] [Indexed: 11/04/2022] Open
Abstract
Glaucoma is a degenerative optic neuropathy characterized by retinal ganglion cell (RGC) loss and visual field defects. It is known that in some glaucoma patients, death of RGCs continues despite intraocular pressure (IOP) reduction. Neuroprotection in the field of glaucoma is defined as any treatment, independent of IOP reduction, which prevents RGC death. Glutamate antagonists, ginkgo biloba extract, neurotrophic factors, antioxidants, calcium channel blockers, brimonidine, glaucoma medications with blood regulatory effect and nitric oxide synthase inhibitors are among compounds with possible neuroprotective activity in preclinical studies. A few agents (such as brimonidine or memantine) with neuroprotective effects in experimental studies have advanced to clinical trials; however the results of clinical trials for these agents have not been conclusive. Nevertheless, lack of compelling clinical evidence has not prevented the off-label use of some of these compounds in glaucoma practice. Stem cell transplantation has been reported to halt experimental neurodegenerative disease processes in the absence of cell replacement. It has been hypothesized that transplantation of some types of stem cells activates multiple neuroprotective pathways via secretion of various factors. The advantage of this approach is a prolonged and targeted effect. Important concerns in this field include the secretion of unwanted harmful mediators, graft survival issues and tumorigenesis. Neuroprotection in glaucoma, pharmacologically or by stem cell transplantation, is an interesting subject waiting for broad and multidisciplinary collaborative studies to better clarify its role in clinical practice.
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Affiliation(s)
- Azadeh Doozandeh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahin Yazdani
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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50
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Pharmacologically targeted NMDA receptor antagonism by NitroMemantine for cerebrovascular disease. Sci Rep 2015; 5:14781. [PMID: 26477507 PMCID: PMC4609936 DOI: 10.1038/srep14781] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/09/2015] [Indexed: 01/28/2023] Open
Abstract
Stroke and vascular dementia are leading causes of morbidity and mortality. Neuroprotective therapies have been proposed but none have proven clinically tolerated and effective. While overstimulation of N-methyl-d-aspartate-type glutamate receptors (NMDARs) is thought to contribute to cerebrovascular insults, the importance of NMDARs in physiological function has made this target, at least in the view of many in ‘Big Pharma,’ ‘undruggable’ for this indication. Here, we describe novel NitroMemantine drugs, comprising an adamantane moiety that binds in the NMDAR-associated ion channel that is used to target a nitro group to redox-mediated regulatory sites on the receptor. The NitroMemantines are both well tolerated and effective against cerebral infarction in rodent models via a dual allosteric mechanism of open-channel block and NO/redox modulation of the receptor. Targeted S-nitrosylation of NMDARs by NitroMemantine is potentiated by hypoxia and thereby directed at ischemic neurons. Allosteric approaches to tune NMDAR activity may hold therapeutic potential for cerebrovascular disorders.
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