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Ueta Y, Miyata M. Functional and structural synaptic remodeling mechanisms underlying somatotopic organization and reorganization in the thalamus. Neurosci Biobehav Rev 2023; 152:105332. [PMID: 37524138 DOI: 10.1016/j.neubiorev.2023.105332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/09/2023] [Accepted: 07/27/2023] [Indexed: 08/02/2023]
Abstract
The somatosensory system organizes the topographic representation of body maps, termed somatotopy, at all levels of an ascending hierarchy. Postnatal maturation of somatotopy establishes optimal somatosensation, whereas deafferentation in adults reorganizes somatotopy, which underlies pathological somatosensation, such as phantom pain and complex regional pain syndrome. Here, we focus on the mouse whisker somatosensory thalamus to study how sensory experience shapes the fine topography of afferent connectivity during the critical period and what mechanisms remodel it and drive a large-scale somatotopic reorganization after peripheral nerve injury. We will review our findings that, following peripheral nerve injury in adults, lemniscal afferent synapses onto thalamic neurons are remodeled back to immature configuration, as if the critical period reopens. The remodeling process is initiated with local activation of microglia in the brainstem somatosensory nucleus downstream to injured nerves and heterosynaptically controlled by input from GABAergic and cortical neurons to thalamic neurons. These fruits of thalamic studies complement well-studied cortical mechanisms of somatotopic organization and reorganization and unveil potential intervention points in treating pathological somatosensation.
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Affiliation(s)
- Yoshifumi Ueta
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
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2
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Mansouri M, Kremser L, Nguyen TP, Kasugai Y, Caberlotto L, Gassmann M, Sarg B, Lindner H, Bettler B, Carboni L, Ferraguti F. Protein Networks Associated with Native Metabotropic Glutamate 1 Receptors (mGlu 1) in the Mouse Cerebellum. Cells 2023; 12:1325. [PMID: 37174725 PMCID: PMC10177021 DOI: 10.3390/cells12091325] [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: 03/17/2023] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 05/15/2023] Open
Abstract
The metabotropic glutamate receptor 1 (mGlu1) plays a pivotal role in synaptic transmission and neuronal plasticity. Despite the fact that several interacting proteins involved in the mGlu1 subcellular trafficking and intracellular transduction mechanisms have been identified, the protein network associated with this receptor in specific brain areas remains largely unknown. To identify novel mGlu1-associated protein complexes in the mouse cerebellum, we used an unbiased tissue-specific proteomic approach, namely co-immunoprecipitation followed by liquid chromatography/tandem mass spectrometry analysis. Many well-known protein complexes as well as novel interactors were identified, including G-proteins, Homer, δ2 glutamate receptor, 14-3-3 proteins, and Na/K-ATPases. A novel putative interactor, KCTD12, was further investigated. Reverse co-immunoprecipitation with anti-KCTD12 antibodies revealed mGlu1 in wild-type but not in KCTD12-knock-out homogenates. Freeze-fracture replica immunogold labeling co-localization experiments showed that KCTD12 and mGlu1 are present in the same nanodomain in Purkinje cell spines, although at a distance that suggests that this interaction is mediated through interposed proteins. Consistently, mGlu1 could not be co-immunoprecipitated with KCTD12 from a recombinant mammalian cell line co-expressing the two proteins. The possibility that this interaction was mediated via GABAB receptors was excluded by showing that mGlu1 and KCTD12 still co-immunoprecipitated from GABAB receptor knock-out tissue. In conclusion, this study identifies tissue-specific mGlu1-associated protein clusters including KCTD12 at Purkinje cell synapses.
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Affiliation(s)
- Mahnaz Mansouri
- Department of Pharmacology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (Y.K.)
| | - Leopold Kremser
- Institute of Medical Biochemistry, Protein Core Facility, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.K.); (B.S.); (H.L.)
| | | | - Yu Kasugai
- Department of Pharmacology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (Y.K.)
| | - Laura Caberlotto
- Centre for Computational and Systems Biology (COSBI), The Microsoft Research University of Trento, 38068 Rovereto, Italy;
| | - Martin Gassmann
- Department of Biomedicine, Pharmazentrum, University of Basel, 4056 Basel, Switzerland; (M.G.); (B.B.)
| | - Bettina Sarg
- Institute of Medical Biochemistry, Protein Core Facility, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.K.); (B.S.); (H.L.)
| | - Herbert Lindner
- Institute of Medical Biochemistry, Protein Core Facility, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.K.); (B.S.); (H.L.)
| | - Bernhard Bettler
- Department of Biomedicine, Pharmazentrum, University of Basel, 4056 Basel, Switzerland; (M.G.); (B.B.)
| | - Lucia Carboni
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy;
| | - Francesco Ferraguti
- Department of Pharmacology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (Y.K.)
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3
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Yadav P, Podia M, Kumari SP, Mani I. Glutamate receptor endocytosis and signaling in neurological conditions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 196:167-207. [PMID: 36813358 DOI: 10.1016/bs.pmbts.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The non-essential amino acid glutamate acts as a major excitatory neurotransmitter and plays a significant role in the central nervous system (CNS). It binds with two different types of receptors, ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs), responsible for the postsynaptic excitation of neurons. They are important for memory, neural development and communication, and learning. Endocytosis and subcellular trafficking of the receptor are essential for the regulation of receptor expression on the cell membrane and excitation of the cells. The endocytosis and trafficking of the receptor are dependent on its type, ligand, agonist, and antagonist present. This chapter discusses the types of glutamate receptors, their subtypes, and the regulation of their internalization and trafficking. The roles of glutamate receptors in neurological diseases are also briefly discussed.
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Affiliation(s)
- Prerna Yadav
- Department of Microbiology, University of Delhi, New Delhi, India
| | - Mansi Podia
- Department of Microbiology, University of Delhi, New Delhi, India
| | - Shashi Prabha Kumari
- Department of Microbiology, Ram Lal Anand College, University of Delhi, New Delhi, India
| | - Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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4
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Hoglund BK, Carfagno V, Olive MF, Leyrer-Jackson JM. Metabotropic glutamate receptors and cognition: From underlying plasticity and neuroprotection to cognitive disorders and therapeutic targets. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 168:367-413. [PMID: 36868635 DOI: 10.1016/bs.irn.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are G protein-coupled receptors that play pivotal roles in mediating the activity of neurons and other cell types within the brain, communication between cell types, synaptic plasticity, and gene expression. As such, these receptors play an important role in a number of cognitive processes. In this chapter, we discuss the role of mGlu receptors in various forms of cognition and their underlying physiology, with an emphasis on cognitive dysfunction. Specifically, we highlight evidence that links mGlu physiology to cognitive dysfunction across brain disorders including Parkinson's disease, Alzheimer's disease, Fragile X syndrome, post-traumatic stress disorder, and schizophrenia. We also provide recent evidence demonstrating that mGlu receptors may elicit neuroprotective effects in particular disease states. Lastly, we discuss how mGlu receptors can be targeted utilizing positive and negative allosteric modulators as well as subtype specific agonists and antagonist to restore cognitive function across these disorders.
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Affiliation(s)
- Brandon K Hoglund
- Department of Medical Education, School of Medicine, Creighton University, Phoenix, AZ, United States
| | - Vincent Carfagno
- School of Medicine, Midwestern University, Glendale, AZ, United States
| | - M Foster Olive
- Department of Psychology, Arizona State University, Tempe, AZ, United States
| | - Jonna M Leyrer-Jackson
- Department of Medical Education, School of Medicine, Creighton University, Phoenix, AZ, United States.
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5
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de Lima IB, Ribeiro FM. The Implication of Glial Metabotropic Glutamate Receptors in Alzheimer's Disease. Curr Neuropharmacol 2023; 21:164-182. [PMID: 34951388 PMCID: PMC10190153 DOI: 10.2174/1570159x20666211223140303] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) was first identified more than 100 years ago, yet aspects pertaining to its origin and the mechanisms underlying disease progression are not well known. To this date, there is no therapeutic approach or disease-modifying drug that could halt or at least delay disease progression. Until recently, glial cells were seen as secondary actors in brain homeostasis. Although this view was gradually refuted and the relevance of glial cells for the most diverse brain functions such as synaptic plasticity and neurotransmission was vastly proved, many aspects of its functioning, as well as its role in pathological conditions, remain poorly understood. Metabotropic glutamate receptors (mGluRs) in glial cells were shown to be involved in neuroinflammation and neurotoxicity. Besides its relevance for glial function, glutamatergic receptors are also central in the pathology of AD, and recent studies have shown that glial mGluRs play a role in the establishment and progression of AD. AD-related alterations in Ca2+ signalling, APP processing, and Aβ load, as well as AD-related neurodegeneration, are influenced by glial mGluRs. However, different types of mGluRs play different roles, depending on the cell type and brain region that is being analysed. Therefore, in this review, we focus on the current understanding of glial mGluRs and their implication in AD, providing an insight for future therapeutics and identifying existing research gaps worth investigating.
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Affiliation(s)
- Izabella B.Q. de Lima
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fabíola M. Ribeiro
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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6
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Fabian CB, Seney ML, Joffe ME. Sex differences and hormonal regulation of metabotropic glutamate receptor synaptic plasticity. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 168:311-347. [PMID: 36868632 PMCID: PMC10392610 DOI: 10.1016/bs.irn.2022.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Striking sex differences exist in presentation and incidence of several psychiatric disorders. For example, major depressive disorder is more prevalent in women than men, and women who develop alcohol use disorder progress through drinking milestones more rapidly than men. With regards to psychiatric treatment responses, women respond more favorably to selective serotonin reuptake inhibitors than men, whereas men have better outcomes when prescribed tricyclic antidepressants. Despite such well-documented biases in incidence, presentation, and treatment response, sex as a biological variable has long been neglected in preclinical and clinical research. An emerging family of druggable targets for psychiatric diseases, metabotropic glutamate (mGlu) receptors are G-protein coupled receptors broadly distributed throughout the central nervous system. mGlu receptors confer diverse neuromodulatory actions of glutamate at the levels of synaptic plasticity, neuronal excitability, and gene transcription. In this chapter, we summarize the current preclinical and clinical evidence for sex differences in mGlu receptor function. We first highlight basal sex differences in mGlu receptor expression and function and proceed to describe how gonadal hormones, notably estradiol, regulate mGlu receptor signaling. We then describe sex-specific mechanisms by which mGlu receptors differentially modulate synaptic plasticity and behavior in basal states and models relevant for disease. Finally, we discuss human research findings and highlight areas in need of further research. Taken together, this review emphasizes how mGlu receptor function and expression can differ across sex. Gaining a more complete understanding of how sex differences in mGlu receptor function contribute to psychiatric diseases will be critical in the development of novel therapeutics that are effective in all individuals.
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Affiliation(s)
- Carly B Fabian
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, United States
| | - Marianne L Seney
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, United States
| | - Max E Joffe
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, United States.
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Yang JS, Jeon S, Jang HJ, Yoon SH. Group 1 metabotropic glutamate receptor 5 is involved in synaptically-induced Ca 2+-spikes and cell death in cultured rat hippocampal neurons. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2022; 26:531-540. [PMID: 36302627 PMCID: PMC9614404 DOI: 10.4196/kjpp.2022.26.6.531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/14/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022]
Abstract
Group 1 metabotropic glutamate receptors (mGluRs) can positively affect postsynaptic neuronal excitability and epileptogenesis. The objective of the present study was to determine whether group 1 mGluRs might be involved in synaptically-induced intracellular free Ca2+ concentration ([Ca2+]i) spikes and neuronal cell death induced by 0.1 mM Mg2+ and 10 µM glycine in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague–Dawley rats using imaging methods for Ca2+ and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays for cell survival. Reduction of extracellular Mg2+ concentration ([Mg2+]o) to 0.1 mM induced repetitive [Ca2+]i spikes within 30 sec at day 11.5. The mGluR5 antagonist 6-Methyl-2-(phenylethynyl) pyridine (MPEP) almost completely inhibited the [Ca2+]i spikes, but the mGluR1 antagonist LY367385 did not. The group 1 mGluRs agonist, 3,5-dihydroxyphenylglycine (DHPG), significantly increased the [Ca2+]i spikes. The phospholipase C inhibitor U73122 significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The IP3 receptor antagonist 2-aminoethoxydiphenyl borate or the ryanodine receptor antagonist 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate also significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The TRPC channel inhibitors SKF96365 and flufenamic acid significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The mGluR5 antagonist MPEP significantly increased the neuronal cell survival, but mGluR1 antagonist LY367385 did not. These results suggest a possibility that mGluR5 is involved in synaptically-induced [Ca2+]i spikes and neuronal cell death in cultured rat hippocampal neurons by releasing Ca2+ from IP3 and ryanodine-sensitive intracellular stores and activating TRPC channels.
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Affiliation(s)
- Ji Seon Yang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Sujeong Jeon
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Hyun-Jong Jang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Shin Hee Yoon
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
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8
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Transcriptional regulation of NRF1 on metabotropic glutamate receptors in a neonatal hypoxic‑ischemic encephalopathy rat model. Pediatr Res 2022:10.1038/s41390-022-02353-9. [PMID: 36280709 DOI: 10.1038/s41390-022-02353-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Neonatal hypoxic-ischemic encephalopathy (HIE) is a kind of brain injury that causes severe neurological disorders in newborns. Metabotropic glutamate receptors (mGluRs) and ionotropic glutamate receptors (iGluRs) are significantly associated with HIE and are involved in ischemia-induced excitotoxicity. This study aimed to investigate the upstream mechanisms of mGluRs and the transcriptional regulation by nuclear respiratory factor 1 (NRF1). METHODS The rat model of neonatal HIE was created using unilateral carotid artery ligation and in vitro oxygen-glucose deprivation paradigm. We used western blot, immunofluorescence, Nissl staining, and Morris water maze to investigate the impact of NRF1 on brain damage and learning memory deficit by HIE. We performed ChIP and luciferase activities to identify the transcriptional regulation of NRF1 on mGluRs. RESULTS The neuronal NRF1 and some glutamatergic genes expression synchronously declined in infarcted tissues. The NRF1 overexpression effectively restored the expression of some glutamatergic genes and improved cognitive performance. NRF1 regulated some members of mGluRs and iGluRs in hypoxic-ischemic neurons. Finally, NRF1 is bound to the promoter regions of Grm1, Grm2, and Grm8 to activate their transcription. CONCLUSIONS NRF1 is involved in the pathology of the neonatal HIE rat model, suggesting a novel therapeutic approach to neonatal HIE. IMPACT NRF1 and some glutamatergic genes were synchronously downregulated in the infarcted brain of the neonatal HIE rat model. NRF1 overexpression could rescue cognitive impairment caused by the neonatal HIE rat model. NRF1 regulated the expressions of Grm1, Grm2, and Grm8, which activated their transcription by binding to the promoter regions.
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Ranjbar H, Soti M, Razavinasab M, Kohlmeier KA, Shabani M. The neglected role of endocannabinoid actions at TRPC channels in ataxia. Neurosci Biobehav Rev 2022; 141:104860. [PMID: 36087758 DOI: 10.1016/j.neubiorev.2022.104860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 08/24/2022] [Accepted: 09/03/2022] [Indexed: 12/01/2022]
Abstract
Transient receptor potential (TRP) channels are highly expressed in cells of the cerebellum including in the dendrites and somas of Purkinje cells (PCs). Their endogenous activation promotes influx of Ca2+ and Na+, resulting in depolarization. TRP channels can be activated by endogenous endocannabinoids (eCBs) and activity of TRP channels has been shown to modulate GABA and glutamate transmission. Ataxia is caused by disruption of multiple intracellular pathways which often involve changes in Ca2+ homeostasis that can result in neural cellular dysfunction and cell death. Based on available literature, alteration of transmission of eCBs would be expected to change activity of cerebellar TRP channels. Antagonists of the endocannabinoid system (ECS) including enzymes which break eCBs down have been shown to result in reductions in postsynaptic excitatory activity mediated by TRPC channels. Further, TRPC channel antagonists could modulate both pre and postsynaptically-mediated glutamatergic and GABAergic transmission, resulting in reductions in cell death due to excitotoxicity and dysfunctions caused by abnormal inhibitory signaling. Accordingly, TRP channels, and in particular the TRPC channel, represent a potential therapeutic target for management of ataxia.
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Affiliation(s)
- Hoda Ranjbar
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Monavareh Soti
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Moazamehosadat Razavinasab
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Kristi A Kohlmeier
- Department of Drug Design and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
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Azam S, Jakaria M, Kim J, Ahn J, Kim IS, Choi DK. Group I mGluRs in Therapy and Diagnosis of Parkinson’s Disease: Focus on mGluR5 Subtype. Biomedicines 2022; 10:biomedicines10040864. [PMID: 35453614 PMCID: PMC9032558 DOI: 10.3390/biomedicines10040864] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Metabotropic glutamate receptors (mGluRs; members of class C G-protein-coupled receptors) have been shown to modulate excitatory neurotransmission, regulate presynaptic extracellular glutamate levels, and modulate postsynaptic ion channels on dendritic spines. mGluRs were found to activate myriad signalling pathways to regulate synapse formation, long-term potentiation, autophagy, apoptosis, necroptosis, and pro-inflammatory cytokines release. A notorious expression pattern of mGluRs has been evident in several neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and schizophrenia. Among the several mGluRs, mGluR5 is one of the most investigated types of considered prospective therapeutic targets and potential diagnostic tools in neurodegenerative diseases and neuropsychiatric disorders. Recent research showed mGluR5 radioligands could be a potential tool to assess neurodegenerative disease progression and trace respective drugs’ kinetic properties. This article provides insight into the group I mGluRs, specifically mGluR5, in the progression and possible therapy for PD.
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Affiliation(s)
- Shofiul Azam
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Korea; (S.A.); (M.J.); (J.K.); (J.A.)
| | - Md. Jakaria
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Korea; (S.A.); (M.J.); (J.K.); (J.A.)
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia
| | - JoonSoo Kim
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Korea; (S.A.); (M.J.); (J.K.); (J.A.)
| | - Jaeyong Ahn
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Korea; (S.A.); (M.J.); (J.K.); (J.A.)
| | - In-Su Kim
- Department of Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease (RID), Konkuk University, Chungju 27478, Korea
- Correspondence: (I.-S.K.); (D.-K.C.); Tel.: +82-43-840-3905 (I.-S.K.); +82-43-840-3610 (D.-K.C.); Fax: +82-43-840-3872 (D.-K.C.)
| | - Dong-Kug Choi
- Department of Applied Life Science, Graduate School, BK21 Program, Konkuk University, Chungju 27478, Korea; (S.A.); (M.J.); (J.K.); (J.A.)
- Department of Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease (RID), Konkuk University, Chungju 27478, Korea
- Correspondence: (I.-S.K.); (D.-K.C.); Tel.: +82-43-840-3905 (I.-S.K.); +82-43-840-3610 (D.-K.C.); Fax: +82-43-840-3872 (D.-K.C.)
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11
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Seo SY, Yang JH, Kim S, Sohn S, Oh JH, Mao L, Wang JQ, Choe ES. Interaction of JNK and mGluR5 in the regulation of psychomotor behaviours after repeated cocaine administration. Addict Biol 2022; 27:e13127. [PMID: 35229936 DOI: 10.1111/adb.13127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/30/2022]
Abstract
Activation of protein kinases after cocaine administration controls psychomotor behaviours by interacting with metabotropic receptors in the brain. This study identified how c-Jun N-terminal kinase (JNK) interacts with metabotropic glutamate receptor 5 (mGluR5) in vitro and in the caudate and putamen (CPu). The potential role of this interaction in the regulation of psychomotor behaviour was also evaluated after administration of cocaine. Active JNK phosphorylates a threonine residue at position 1055 in the carboxyl terminus (CT) of mGluR5 in vitro. The binding of active JNK to the D-motif within CT2 is necessary for that phosphorylation. Interaction of phosphorylated JNK and mGluR5 occurs in the CPu. Unilateral interference of the interaction decreases the repeated cocaine-induced increases in locomotor activity and conditioned place preference. These findings suggest that activation of JNK has the capability to interact with mGluR5 in the CPu. Phosphorylation of mGluR5 following the JNK-mGluR5 interaction may be responsible for the potentiation of behavioural sensitisation and cocaine-wanting behaviour in response to cocaine administration.
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Affiliation(s)
- Su Yeon Seo
- Department of Biological Sciences Pusan National University Busan South Korea
| | - Ju Hwan Yang
- Department of Biological Sciences Pusan National University Busan South Korea
| | - Sunghyun Kim
- Department of Biological Sciences Pusan National University Busan South Korea
| | - Sumin Sohn
- Department of Biological Sciences Pusan National University Busan South Korea
| | - Jeong Hwan Oh
- Department of Biological Sciences Pusan National University Busan South Korea
| | - Li‐Min Mao
- Department of Anesthesiology and Basic Medical Science University of Missouri–Kansas City Kansas City Missouri USA
| | - John Q. Wang
- Department of Anesthesiology and Basic Medical Science University of Missouri–Kansas City Kansas City Missouri USA
| | - Eun Sang Choe
- Department of Biological Sciences Pusan National University Busan South Korea
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12
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Group I Metabotropic Glutamate Receptors and Interacting Partners: An Update. Int J Mol Sci 2022; 23:ijms23020840. [PMID: 35055030 PMCID: PMC8778124 DOI: 10.3390/ijms23020840] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 12/21/2022] Open
Abstract
Group I metabotropic glutamate (mGlu) receptors (mGlu1/5 subtypes) are G protein-coupled receptors and are broadly expressed in the mammalian brain. These receptors play key roles in the modulation of normal glutamatergic transmission and synaptic plasticity, and abnormal mGlu1/5 signaling is linked to the pathogenesis and symptomatology of various mental and neurological disorders. Group I mGlu receptors are noticeably regulated via a mechanism involving dynamic protein-protein interactions. Several synaptic protein kinases were recently found to directly bind to the intracellular domains of mGlu1/5 receptors and phosphorylate the receptors at distinct amino acid residues. A variety of scaffolding and adaptor proteins also interact with mGlu1/5. Constitutive or activity-dependent interactions between mGlu1/5 and their interacting partners modulate trafficking, anchoring, and expression of the receptors. The mGlu1/5-associated proteins also finetune the efficacy of mGlu1/5 postreceptor signaling and mGlu1/5-mediated synaptic plasticity. This review analyzes the data from recent studies and provides an update on the biochemical and physiological properties of a set of proteins or molecules that interact with and thus regulate mGlu1/5 receptors.
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13
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Membrane trafficking and positioning of mGluRs at presynaptic and postsynaptic sites of excitatory synapses. Neuropharmacology 2021; 200:108799. [PMID: 34592242 DOI: 10.1016/j.neuropharm.2021.108799] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/31/2021] [Accepted: 09/17/2021] [Indexed: 01/21/2023]
Abstract
The plethora of functions of glutamate in the brain are mediated by the complementary actions of ionotropic and metabotropic glutamate receptors (mGluRs). The ionotropic glutamate receptors carry most of the fast excitatory transmission, while mGluRs modulate transmission on longer timescales by triggering multiple intracellular signaling pathways. As such, mGluRs mediate critical aspects of synaptic transmission and plasticity. Interestingly, at synapses, mGluRs operate at both sides of the cleft, and thus bidirectionally exert the effects of glutamate. At postsynaptic sites, group I mGluRs act to modulate excitability and plasticity. At presynaptic sites, group II and III mGluRs act as auto-receptors, modulating release properties in an activity-dependent manner. Thus, synaptic mGluRs are essential signal integrators that functionally couple presynaptic and postsynaptic mechanisms of transmission and plasticity. Understanding how these receptors reach the membrane and are positioned relative to the presynaptic glutamate release site are therefore important aspects of synapse biology. In this review, we will discuss the currently known mechanisms underlying the trafficking and positioning of mGluRs at and around synapses, and how these mechanisms contribute to synaptic functioning. We will highlight outstanding questions and present an outlook on how recent technological developments will move this exciting research field forward.
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14
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Capsoni S, Fogli Iseppe A, Casciano F, Pignatelli A. Unraveling the Role of Dopaminergic and Calretinin Interneurons in the Olfactory Bulb. Front Neural Circuits 2021; 15:718221. [PMID: 34690707 PMCID: PMC8531203 DOI: 10.3389/fncir.2021.718221] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/31/2021] [Indexed: 11/27/2022] Open
Abstract
The perception and discriminating of odors are sensory activities that are an integral part of our daily life. The first brain region where odors are processed is the olfactory bulb (OB). Among the different cell populations that make up this brain area, interneurons play an essential role in this sensory activity. Moreover, probably because of their activity, they represent an exception compared to other parts of the brain, since OB interneurons are continuously generated in the postnatal and adult period. In this review, we will focus on periglomerular (PG) cells which are a class of interneurons found in the glomerular layer of the OB. These interneurons can be classified into distinct subtypes based on their neurochemical nature, based on the neurotransmitter and calcium-binding proteins expressed by these cells. Dopaminergic (DA) periglomerular cells and calretinin (CR) cells are among the newly generated interneurons and play an important role in the physiology of OB. In the OB, DA cells are involved in the processing of odors and the adaptation of the bulbar network to external conditions. The main role of DA cells in OB appears to be the inhibition of glutamate release from olfactory sensory fibers. Calretinin cells are probably the best morphologically characterized interneurons among PG cells in OB, but little is known about their function except for their inhibitory effect on noisy random excitatory signals arriving at the main neurons. In this review, we will mainly describe the electrophysiological properties related to the excitability profiles of DA and CR cells, with a particular view on the differences that characterize DA mature interneurons from cells in different stages of adult neurogenesis.
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Affiliation(s)
- Simona Capsoni
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
- Bio@SNS Laboratory of Biology, Scuola Normale Superiore, Pisa, Italy
| | - Alex Fogli Iseppe
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Fabio Casciano
- Department of Translational Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
- Interdepartmental Research Centre for the Study of Multiple Sclerosis and Inflammatory and Degenerative Diseases of the Nervous System, University of Ferrara, Ferrara, Italy
| | - Angela Pignatelli
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
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15
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Su LD, Wang N, Han J, Shen Y. Group 1 Metabotropic Glutamate Receptors in Neurological and Psychiatric Diseases: Mechanisms and Prospective. Neuroscientist 2021; 28:453-468. [PMID: 34088252 PMCID: PMC9449437 DOI: 10.1177/10738584211021018] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors
that are activated by glutamate in the central nervous system (CNS).
Basically, mGluRs contribute to fine-tuning of synaptic efficacy and
control the accuracy and sharpness of neurotransmission. Among eight
subtypes, mGluR1 and mGluR5 belong to group 1 (Gp1) family, and are
implicated in multiple CNS disorders, such as Alzheimer’s disease,
autism, Parkinson’s disease, and so on. In the present review, we
systematically discussed underlying mechanisms and prospective of Gp1
mGluRs in a group of neurological and psychiatric diseases, including
Alzheimer’s disease, Parkinson’s disease, autism spectrum disorder,
epilepsy, Huntington’s disease, intellectual disability, Down’s
syndrome, Rett syndrome, attention-deficit hyperactivity disorder,
addiction, anxiety, nociception, schizophrenia, and depression, in
order to provide more insights into the therapeutic potential of Gp1
mGluRs.
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Affiliation(s)
- Li-Da Su
- Neuroscience Care Unit, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Na Wang
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Junhai Han
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Ying Shen
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, China
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16
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mGluR1 signaling in cerebellar Purkinje cells: Subcellular organization and involvement in cerebellar function and disease. Neuropharmacology 2021; 194:108629. [PMID: 34089728 DOI: 10.1016/j.neuropharm.2021.108629] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 11/20/2022]
Abstract
The cerebellum is essential for the control, coordination, and learning of movements, and for certain aspects of cognitive function. Purkinje cells are the sole output neurons in the cerebellar cortex and therefore play crucial roles in the diverse functions of the cerebellum. The type 1 metabotropic glutamate receptor (mGluR1) is prominently enriched in Purkinje cells and triggers downstream signaling pathways that are required for functional and structural plasticity, and for synaptic responses. To understand how mGluR1 contributes to cerebellar functions, it is important to consider not only the operational properties of this receptor, but also its spatial organization and the molecular interactions that enable its proper functioning. In this review, we highlight how mGluR1 and its related signaling molecules are organized into tightly coupled microdomains to fulfill physiological functions. We also describe emerging evidence that altered mGluR1 signaling in Purkinje cells underlies cerebellar dysfunction in ataxias of human patients and mouse models.
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17
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Cocaine use disorder: A look at metabotropic glutamate receptors and glutamate transporters. Pharmacol Ther 2021; 221:107797. [DOI: 10.1016/j.pharmthera.2020.107797] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 11/04/2020] [Indexed: 01/08/2023]
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18
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Noh W, Lee M, Kim HJ, Kim KS, Yang S. Hypergravity induced disruption of cerebellar motor coordination. Sci Rep 2020; 10:4452. [PMID: 32157179 PMCID: PMC7064588 DOI: 10.1038/s41598-020-61453-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 02/21/2020] [Indexed: 01/23/2023] Open
Abstract
The cerebellum coordinates voluntary movements for balanced motor activity in a normal gravity condition. It remains unknown how hypergravity is associated with cerebellum-dependent motor behaviors and Purkinje cell’s activities. In order to investigate the relationship between gravity and cerebellar physiology, we measured AMPA-mediated fast currents and mGluR1-mediated slow currents of cerebellar Purkinje cells along with cerebellum-dependent behaviors such as the footprint and irregular ladder under a hypergravity condition. We found abnormal animal behaviors in the footprint and irregular ladder tests under hypergravity. They are correlated with decreased AMPA and mGluR1-mediated synaptic currents of Purkinje cells. These results indicate that gravity regulates the activity of Purkinje cells, thereby modulating cerebellum-dependent motor outputs.
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Affiliation(s)
- Wonjun Noh
- Department of Nano-Bioengineering, Incheon National University, Incheon, Korea
| | - Minseok Lee
- Department of Nano-Bioengineering, Incheon National University, Incheon, Korea
| | - Hyun Ji Kim
- Department of Otorhinolaryngology-Head & Neck surgery, Inha University, College of medicine, Incheon, Korea
| | - Kyu-Sung Kim
- Department of Otorhinolaryngology-Head & Neck surgery, Inha University, College of medicine, Incheon, Korea.
| | - Sunggu Yang
- Department of Nano-Bioengineering, Incheon National University, Incheon, Korea.
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19
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Kim BW, Jeong YE, Wong M, Martin LJ. DNA damage accumulates and responses are engaged in human ALS brain and spinal motor neurons and DNA repair is activatable in iPSC-derived motor neurons with SOD1 mutations. Acta Neuropathol Commun 2020; 8:7. [PMID: 32005289 PMCID: PMC6995159 DOI: 10.1186/s40478-019-0874-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022] Open
Abstract
DNA damage is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, relationships between DNA damage accumulation, DNA damage response (DDR), and upper and lower motor neuron vulnerability in human ALS are unclear; furthermore, it is unknown whether epigenetic silencing of DNA repair pathways contributes to ALS pathogenesis. We tested the hypotheses that DNA damage accumulates in ALS motor neurons along with diminished DDR, and that DNA repair genes undergo hypermethylation. Human postmortem CNS tissue was obtained from ALS cases (N = 34) and age-matched controls without neurologic disease (N = 15). Compared to age-matched controls, abasic sites accumulated in genomic DNA of ALS motor cortex and laser capture microdissection-acquired spinal motor neurons but not in motor neuron mitochondrial DNA. By immunohistochemistry, DNA damage accumulated significantly in upper and lower motor neurons in ALS cases as single-stranded DNA and 8-hydroxy-deoxyguanosine (OHdG) compared to age-matched controls. Significant DDR was engaged in ALS motor neurons as evidenced by accumulation of c-Abl, nuclear BRCA1, and ATM activation. DNA damage and DDR were present in motor neurons at pre-attritional stages and throughout the somatodendritic attritional stages of neurodegeneration. Motor neurons with DNA damage were also positive for activated p53 and cleaved caspase-3. Gene-specific promoter DNA methylation pyrosequencing identified the DNA repair genes Ogg1, Apex1, Pnkp and Aptx as hypomethylated in ALS. In human induced-pluripotent stem cell (iPSC)-derived motor neurons with familial ALS SOD1 mutations, DNA repair capacity was similar to isogenic control motor neurons. Our results show that vulnerable neurons in human ALS accumulate DNA damage, and contrary to our hypothesis, strongly activate and mobilize response effectors and DNA repair genes. This DDR in ALS motor neurons involves recruitment of c-Abl and BRCA1 to the nucleus in vivo, and repair of DNA double-strand breaks in human ALS motor neurons with SOD1 mutations in cell culture.
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Affiliation(s)
- Byung Woo Kim
- Department of Pathology, Johns Hopkins University School of Medicine, 558 Ross Building, 720 Rutland Avenue, Baltimore, MD, 21205-2196, USA
- Division of Neuropathology, the Pathobiology Graduate Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ye Eun Jeong
- Division of Neuropathology, the Pathobiology Graduate Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Margaret Wong
- Department of Pathology, Johns Hopkins University School of Medicine, 558 Ross Building, 720 Rutland Avenue, Baltimore, MD, 21205-2196, USA
| | - Lee J Martin
- Department of Pathology, Johns Hopkins University School of Medicine, 558 Ross Building, 720 Rutland Avenue, Baltimore, MD, 21205-2196, USA.
- Division of Neuropathology, the Pathobiology Graduate Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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20
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Laukkanen V, Kärkkäinen O, Kautiainen H, Tiihonen J, Storvik M. Increased [³H]quisqualic acid binding density in the dorsal striatum and anterior insula of alcoholics: A post-mortem whole-hemisphere autoradiography study. Psychiatry Res Neuroimaging 2019; 287:63-69. [PMID: 30991250 DOI: 10.1016/j.pscychresns.2019.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 04/05/2019] [Accepted: 04/07/2019] [Indexed: 01/28/2023]
Abstract
The function of group I metabotropic glutamate receptors mGluR1 and mGluR5 is involved in the hyperglutamatergic state caused by chronic alcohol. Preclinical studies suggest that group I mGluR modulation could serve as a novel treatment of alcoholism. Considering the wide role of glutamatergic neurochemistry in addiction, group I mGluR binding was studied in brain areas involved in decision-making, learning and memory. Post-mortem whole hemisphere autoradiography was used to study the binding density of [³H]quisqualic acid, a potent group I mGluR agonist, in 9 Cloninger type 1 alcoholics, 8 Cloninger type 2 alcoholics and 10 controls. Binding was studied in the dorsal striatum, hippocampus and cortex. Alcoholics displayed a trend towards increased [³H]quisqualic acid binding in all brain areas. The most robust findings were in the putamen (p = 0.006) and anterior insula (p = 0.005), where both alcoholic subtypes displayed increased binding compared to the controls. These findings suggest altered group I mGluR function in alcoholic subjects in the dorsal striatum, which is involved in habitual learning, and in the anterior insula, which has a pivotal role in the perception of bodily sensations. Increased [³H]quisqualic acid binding might suggest a beneficial impact of mGluR1/5 modulators in the treatment of alcoholism.
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Affiliation(s)
- Virpi Laukkanen
- Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Niuvankuja 65, FI-70240 Kuopio, Finland; Department of Psychiatry, Kuopio University Hospital, P.O. Box 100, FI-70029 Kuopio, Finland.
| | - Olli Kärkkäinen
- Department of Pharmacology and Toxicology, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Hannu Kautiainen
- Unit of Primary Health Care, Helsinki University Central Hospital, P.O. Box 705, FI-00029 HUS, Helsinki, Finland; Department of General Practice, Helsinki University, P.O. Box 20, FI-00014 Helsinki, Finland
| | - Jari Tiihonen
- Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Niuvankuja 65, FI-70240 Kuopio, Finland; Department of Clinical Neuroscience, Karolinska Institutet, Karolinska Hospital, 17176 Stockholm, Sweden
| | - Markus Storvik
- Department of Psychiatry, Kuopio University Hospital, P.O. Box 100, FI-70029 Kuopio, Finland
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21
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Christ M, Müller T, Bien C, Hagen T, Naumann M, Bayas A. Autoimmune encephalitis associated with antibodies against the metabotropic glutamate receptor type 1: case report and review of the literature. Ther Adv Neurol Disord 2019; 12:1756286419847418. [PMID: 31205493 PMCID: PMC6535747 DOI: 10.1177/1756286419847418] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/09/2019] [Indexed: 12/14/2022] Open
Abstract
Autoimmune encephalitis associated with antibodies against the metabotropic glutamate receptor type 1 is a rare autoimmune disease with only 18 cases being described in the literature so far. Most patients present with subacute cerebellar ataxia. In more than one third of cases a paraneoplastic aetiology has been suspected. Here we report a case of a 45-year-old man without known malignancy, who presented with progressive dysarthria and subsequently developed subacute cerebellar ataxia. Immunotherapy with glucocorticoids, i.v. immunoglobulins and rituximab improved clinical symptoms and resulted in a stable disease course up to the present. The article describes the clinical course of the patient with a follow-up-period of approximately 24 months and reviews the cases reported in the literature so far.
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Affiliation(s)
- Monika Christ
- Department of Neurology, University Hospital of Augsburg, Stenglinstraße 2, D-86156 Augsburg, Germany
| | | | | | | | - Markus Naumann
- Department of Neurology, University Hospital of Augsburg, Augsburg, Germany
| | - Antonios Bayas
- Department of Neurology, University Hospital of Augsburg, Augsburg, Germany
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22
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Unchanged type 1 metabotropic glutamate receptor availability in patients with Alzheimer's disease: A study using 11C-ITMM positron emission tomography. NEUROIMAGE-CLINICAL 2019; 22:101783. [PMID: 30909027 PMCID: PMC6434168 DOI: 10.1016/j.nicl.2019.101783] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/04/2019] [Accepted: 03/16/2019] [Indexed: 01/06/2023]
Abstract
Imaging of type 1 metabotropic glutamate receptor (mGluR1) has recently become possible using positron emission tomography (PET). To date, little evidence exists on the role of mGluR1 in the pathophysiology of Alzheimer's disease (AD). We aimed to examine mGluR1 availability in patients with AD. Ten patients with AD (78.9 ± 5.9 years) and 12 age-matched volunteers (74.6 ± 2.6 years) underwent PET using an mGluR1 radiotracer. All patients were anti-dementia drug-naive. Volumes-of-interest were placed on the anterior and posterior lobes and vermis in the cerebellum and frontal, parietal, and temporal cortices. The binding potential (BPND) was calculated to estimate mGluR1 availability, and partial volume correction was applied to the BPND values. Mini Mental State Examination (MMSE) scores were also obtained (22.0 ± 4.8). No significant difference was observed in BPND between the AD and control groups in the anterior lobe (p = .30), posterior lobe (p = .95), vermis (p = .96), frontal cortex (p = .61), parietal cortex (p = .59), or temporal cortex (p = .27). No significant correlation was observed between BPND and MMSE scores in the anterior lobe (p = .59), posterior lobe (p = .35), vermis (p = .92), frontal cortex (p = .78), parietal cortex (p = .83), or temporal cortex (p = .82). In conclusions, this study suggests that mGluR1 availability is unchanged in the relatively early stage of AD. However, because regional mGluR1 availability may change with the progression of AD, further longitudinal follow-up is necessary. Metabotropic glutamate receptors (mGluR) can be affected in AD. Little evidence exists on the role of type 1 mGluR (mGluR1) in AD. We examined mGluR1 availability in patients with AD. mGluR1 availability was unchanged in the relatively early stage of AD.
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23
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Crupi R, Impellizzeri D, Cuzzocrea S. Role of Metabotropic Glutamate Receptors in Neurological Disorders. Front Mol Neurosci 2019; 12:20. [PMID: 30800054 PMCID: PMC6375857 DOI: 10.3389/fnmol.2019.00020] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/21/2019] [Indexed: 12/20/2022] Open
Abstract
Glutamate is a fundamental excitatory neurotransmitter in the mammalian central nervous system (CNS), playing key roles in memory, neuronal development, and synaptic plasticity. Moreover, excessive glutamate release has been implicated in neuronal cell death. There are both ionotropic and metabotropic glutamate receptors (mGluRs), the latter of which can be divided into eight subtypes and three subgroups based on homology sequence and their effects on cell signaling. Indeed, mGluRs exert fine control over glutamate activity by stimulating several cell-signaling pathways via the activation of G protein-coupled (GPC) or G protein-independent cell signaling. The involvement of specific mGluRs in different forms of synaptic plasticity suggests that modulation of mGluRs may aid in the treatment of cognitive impairments related to several neurodevelopmental/psychiatric disorders and neurodegenerative diseases, which are associated with a high economic and social burden. Preclinical and clinical data have shown that, in the CNS, mGluRs are able to modulate presynaptic neurotransmission by fine-tuning neuronal firing and neurotransmitter release in a dynamic, activity-dependent manner. Current studies on drugs that target mGluRs have identified promising, innovative pharmacological tools for the treatment of neurodegenerative and neuropsychiatric conditions, including chronic pain.
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Affiliation(s)
- Rosalia Crupi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Daniela Impellizzeri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy.,Department of Pharmacology and Physiology, Saint Louis University, St. Louis, MO, United States
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24
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Tambasco N, Romoli M, Calabresi P. Selective basal ganglia vulnerability to energy deprivation: Experimental and clinical evidences. Prog Neurobiol 2018; 169:55-75. [DOI: 10.1016/j.pneurobio.2018.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/24/2018] [Accepted: 07/27/2018] [Indexed: 02/07/2023]
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25
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Masilamoni GJ, Smith Y. Metabotropic glutamate receptors: targets for neuroprotective therapies in Parkinson disease. Curr Opin Pharmacol 2018; 38:72-80. [PMID: 29605730 DOI: 10.1016/j.coph.2018.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/12/2018] [Indexed: 01/22/2023]
Abstract
Metabotropic glutamate receptors (mGluRs) are heavily expressed throughout the basal ganglia (BG), where they modulate neuronal excitability, transmitter release and long term synaptic plasticity. Therefore, targeting specific mGluR subtypes by means of selective drugs could be a possible strategy for restoring normal synaptic function and neuronal activity of the BG in Parkinson disease (PD). Preclinical studies have revealed that specific mGluR subtypes mediate significant neuroprotective effects that reduce toxin-induced midbrain dopaminergic neuronal death in animal models of PD. Although the underlying mechanisms of these effects must be further studied, there is evidence that intracellular calcium regulation, anti-inflammatory effects, and glutamatergic network modulation contribute to some of these neuroprotective properties. It is noteworthy that these protective effects extend beyond midbrain dopaminergic neurons to include other monoaminergic cell groups for some mGluRs. In this review, we discuss evidence for mGluR-mediated neuroprotection in PD and highlight the challenges to translate these findings into human trials.
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Affiliation(s)
- Gunasingh J Masilamoni
- Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA; Udall Center of Excellence for Parkinson's Disease, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA
| | - Yoland Smith
- Yerkes National Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA; Department of Neurology, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA; Udall Center of Excellence for Parkinson's Disease, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA.
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26
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Ngomba RT, van Luijtelaar G. Metabotropic glutamate receptors as drug targets for the treatment of absence epilepsy. Curr Opin Pharmacol 2018; 38:43-50. [PMID: 29547778 DOI: 10.1016/j.coph.2018.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/31/2018] [Indexed: 11/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are expressed in key regions of the cortex and the thalamus and are known to regulate spike and wave discharges (SWDs), the electroclinical hallmarks of absence seizures. Recent preclinical studies have highlighted the therapeutic potential of selective group I and III mGlu receptor subtype allosteric modulators, which can suppress pathological SWDs. Of particular interest are positive allosteric modulators (PAMs) for mGlu5 receptors, as they currently show the most promise as novel anti-absence epilepsy drugs. The rational design of novel selective positive and negative allosteric mGlu modulators, especially for the mGlu5 receptor, has been made possible following the recent crystallographic structure determination of group I mGlu receptors. Our current knowledge of the role of different mGlu receptor subtypes in absence epilepsy is outlined in this article.
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Affiliation(s)
- Richard Teke Ngomba
- School of Pharmacy in College of Science, University of Lincoln, Lincoln LN6 7TS, UK.
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27
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Tang ZQ, Lu Y. Anatomy and Physiology of Metabotropic Glutamate Receptors in Mammalian and Avian Auditory System. ACTA ACUST UNITED AC 2018; 1. [PMID: 30854519 DOI: 10.24966/tap-7752/100001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Glutamate, as the major excitatory neurotransmitter used in the vertebrate brain, activates ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), which mediate fast and slow neuronal actions, respectively. mGluRs play important modulatory roles in many brain areas, forming potential targets for drugs developed to treat brain disorders. Here, we review studies on mGluRs in the mammalian and avian auditory system. Although anatomical expression of mGluRs in the cochlear nucleus has been well characterized, data for other auditory nuclei await more systematic investigations especially at the electron microscopy level. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the auditory circuitry in the brainstem. These in vitro physiological studies have demonstrated that mGluRs participate in synaptic transmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between Excitation and Inhibition (E/I) in a variety of auditory structures. However, the modulatory roles of mGluRs in auditory processing remain largely unclear at the system and behavioral levels, and the functions of mGluRs in auditory disorders remain entirely unknown.
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Affiliation(s)
- Zheng-Quan Tang
- Oregon Hearing Research Center, Vollum Institute, Oregon Health and Science University, Oregon, USA
| | - Yong Lu
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Ohio, USA
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28
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Beneventano M, Spampinato SF, Merlo S, Chisari M, Platania P, Ragusa M, Purrello M, Nicoletti F, Sortino MA. Shedding of Microvesicles from Microglia Contributes to the Effects Induced by Metabotropic Glutamate Receptor 5 Activation on Neuronal Death. Front Pharmacol 2017; 8:812. [PMID: 29170640 PMCID: PMC5684115 DOI: 10.3389/fphar.2017.00812] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/26/2017] [Indexed: 01/08/2023] Open
Abstract
Metabotropic glutamate (mGlu) receptor 5 is involved in neuroinflammation and has been shown to mediate reduced inflammation and neurotoxicity and to modify microglia polarization. On the other hand, blockade of mGlu5 receptor results in inhibition of microglia activation. To dissect this controversy, we investigated whether microvesicles (MVs) released from microglia BV2 cells could contribute to the communication between microglia and neurons and whether this interaction was modulated by mGlu5 receptor. Activation of purinergic ionotropic P2X7 receptor with the stable ATP analog benzoyl-ATP (100 μM) caused rapid MVs shedding from BV2 cells. Ionic currents through P2X7 receptor increased in BV2 cells pretreated for 24 h with the mGlu5 receptor agonist CHPG (200 μM) as by patch-clamp recording. This increase was blunted when microglia cells were activated by exposure to lipopolysaccharide (LPS; 0.1 μg/ml for 6 h). Accordingly, a greater amount of MVs formed after CHPG treatment, an effect prevented by the mGlu5 receptor antagonist MTEP (100 μM), as measured by expression of flotillin, a membrane protein enriched in MVs. Transferred MVs were internalized by SH-SY5Y neurons where they did not modify neuronal death induced by a low concentration of rotenone (0.1 μM for 24 h), but significantly increased rotenone neurotoxicity when shed from CHPG-treated BV2 cells. miR146a was increased in CHPG-treated MVs, an effect concealed in MVs from LPS-activated BV2 cells that showed per se an increase in miRNA146a levels. The present data support a role for microglia-shed MVs in mGlu5-mediated modulation of neuronal death and identify miRNAs as potential critical mediators of this interaction.
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Affiliation(s)
- Martina Beneventano
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Simona F Spampinato
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Sara Merlo
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Mariangela Chisari
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Paola Platania
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Marco Ragusa
- Section of Biology and Genetics, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Michele Purrello
- Section of Biology and Genetics, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy.,I.R.C.C.S. Neuromed, Pozzilli, Italy
| | - Maria Angela Sortino
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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An Essential Role of Fyn in the Modulation of Metabotropic Glutamate Receptor 1 in Neurons. eNeuro 2017; 4:eN-NWR-0096-17. [PMID: 28948209 PMCID: PMC5608834 DOI: 10.1523/eneuro.0096-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 08/08/2017] [Accepted: 08/15/2017] [Indexed: 11/26/2022] Open
Abstract
Fyn is a member of the Src family of nonreceptor tyrosine kinases and is broadly expressed in the CNS. As a synapse-enriched kinase, Fyn interacts with and phosphorylates local substrates to regulate synaptic transmission and plasticity, although our knowledge of specific targets of Fyn at synaptic sites remains incomplete and the accurate role of Fyn in regulating synaptic proteins is poorly understood. In this study, we initiated an effort to explore the interaction of Fyn with a metabotropic glutamate receptor (mGluR). We found that recombinant Fyn directly binds to mGluR1a at a consensus binding motif located in the intracellular C-terminus (CT) of mGluR1a in vitro. Similarly, endogenous Fyn interacts with mGluR1a in adult rat cerebellar neurons in vivo. Active Fyn phosphorylates mGluR1a at a conserved tyrosine residue in the CT region. In cerebellar neurons and transfected HEK293T cells, the Fyn-mediated tyrosine phosphorylation of mGluR1a is constitutively active and acts to facilitate the surface expression of mGluR1a and to potentiate the mGluR1a postreceptor signaling. These results support mGluR1a to be a novel substrate of Fyn. Fyn, by binding to and phosphorylating mGluR1a, potentiates surface expression and signaling of the receptors.
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Ishibashi K, Miura Y, Toyohara J, Ishii K, Ishiwata K. Comparison of imaging using 11C-ITMM and 18F-FDG for the detection of cerebellar ataxia. J Neurol Sci 2017; 375:97-102. [PMID: 28320199 DOI: 10.1016/j.jns.2017.01.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 10/20/2022]
Abstract
Objective Newly developed methods for imaging type 1 metabotropic glutamate receptor (mGluR1) have the potential use for estimating cerebellar function. We aimed to compare mGluR1 imaging using N-[4-[6-(isopropylamino)pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-11C-methoxy-N-methylbenzamide (11C-ITMM) with the existing marker, fluorine-18-labeled fluorodeoxyglucose (18F-FDG) imaging, in the cerebellum. METHODS Fourteen subjects consisting of 12 patients with cerebellar ataxia and two healthy subjects underwent 11C-ITMM and 18F-FDG positron emission tomography. The degree of ataxia was scored with the Scale for the Assessment and Rating of Ataxia (SARA). Volumes-of-interest were placed on the anterior and posterior lobes and vermis. The binding potential (BPND) was calculated to estimate mGluR1 availability using the white matter as a reference region. 18F-FDG uptake was normalized using the white matter (FUwm). RESULTS There were significant positive correlations between the BPND and FUwm values in the anterior lobe (r=0.83, P<0.001), posterior lobe (r=0.69, P=0.009), and vermis (r=0.58, P=0.042). Regarding the relationship of SARA scores with the BPND and FUwm values, a significant negative correlation was found only in the anterior lobe between the SARA scores and BPND values (r=-0.64, P=0.029). CONCLUSION This study showed that mGluR1 imaging was comparable to 18F-FDG imaging in the cerebellum. However, mGluR1 imaging was more strongly associated with the SARA scores than 18F-FDG imaging was, suggesting that mGluR1 imaging can be a more specific technique than 18F-FDG imaging for evaluating cerebellar ataxia.
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Affiliation(s)
- Kenji Ishibashi
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komago2me Hospital, Tokyo, Japan.
| | - Yoshiharu Miura
- Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komago2me Hospital, Tokyo, Japan.
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
| | - Kenji Ishii
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
| | - Kiichi Ishiwata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Institute of Cyclotron and Drug Discovery Research, Southern Tohoku Research Institute for Neuroscience, Koriyama, Japan; Department of Biofunctional Imaging, Fukushima Medical University, Fukushima, Japan.
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Metabotropic glutamate receptors and neurodegenerative diseases. Pharmacol Res 2017; 115:179-191. [DOI: 10.1016/j.phrs.2016.11.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/11/2016] [Accepted: 11/15/2016] [Indexed: 12/21/2022]
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Synaptic ERK2 Phosphorylates and Regulates Metabotropic Glutamate Receptor 1 In Vitro and in Neurons. Mol Neurobiol 2016; 54:7156-7170. [PMID: 27796752 DOI: 10.1007/s12035-016-0225-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/13/2016] [Indexed: 12/21/2022]
Abstract
A synaptic pool of extracellular signal-regulated kinases (ERK) controls synaptic transmission, although little is known about its underlying signaling mechanisms. Here, we found that synaptic ERK2 directly binds to postsynaptic metabotropic glutamate receptor 1a (mGluR1a). This binding is direct and the ERK-binding site is located in the intracellular C-terminus (CT) of mGluR1a. Parallel with this binding, ERK2 phosphorylates mGluR1a at a cluster of serine residues in the distal part of mGluR1a-CT. In rat cerebellar neurons, ERK2 interacts with mGluR1a at synaptic sites, and active ERK constitutively phosphorylates mGluR1a under normal conditions. This basal phosphorylation is critical for maintaining adequate surface expression of mGluR1a. ERK is also essential for controlling mGluR1a signaling in triggering distinct postreceptor signaling transduction pathways. In summary, we have demonstrated that mGluR1a is a sufficient substrate of ERK2. ERK that interacts with and phosphorylates mGluR1a is involved in the regulation of the trafficking and signaling of mGluR1.
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Lum JS, Fernandez F, Matosin N, Andrews JL, Huang XF, Ooi L, Newell KA. Neurodevelopmental Expression Profile of Dimeric and Monomeric Group 1 mGluRs: Relevance to Schizophrenia Pathogenesis and Treatment. Sci Rep 2016; 6:34391. [PMID: 27721389 PMCID: PMC5056358 DOI: 10.1038/srep34391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/08/2016] [Indexed: 12/18/2022] Open
Abstract
Group 1 metabotropic glutamate receptors (mGluR1/mGluR5) play an integral role in neurodevelopment and are implicated in psychiatric disorders, such as schizophrenia. mGluR1 and mGluR5 are expressed as homodimers, which is important for their functionality and pharmacology. We examined the protein expression of dimeric and monomeric mGluR1α and mGluR5 in the prefrontal cortex (PFC) and hippocampus throughout development (juvenile/adolescence/adulthood) and in the perinatal phencyclidine (PCP) model of schizophrenia. Under control conditions, mGluR1α dimer expression increased between juvenile and adolescence (209-328%), while monomeric levels remained consistent. Dimeric mGluR5 was steadily expressed across all time points; monomeric mGluR5 was present in juveniles, dramatically declining at adolescence and adulthood (-97-99%). The mGluR regulators, Homer 1b/c and Norbin, significantly increased with age in the PFC and hippocampus. Perinatal PCP treatment significantly increased juvenile dimeric mGluR5 levels in the PFC and hippocampus (37-50%) but decreased hippocampal mGluR1α (-50-56%). Perinatal PCP treatment also reduced mGluR1α dimer levels in the PFC at adulthood (-31%). These results suggest that Group 1 mGluRs have distinct dimeric and monomeric neurodevelopmental patterns, which may impact their pharmacological profiles at specific ages. Perinatal PCP treatment disrupted the early expression of Group 1 mGluRs which may underlie neurodevelopmental alterations observed in this model.
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Affiliation(s)
- Jeremy S. Lum
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
| | - Francesca Fernandez
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
- School of Psychology, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Natalie Matosin
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10 Munich Germany
| | - Jessica L. Andrews
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
| | - Xu-Feng Huang
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Kelly A. Newell
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522 Australia
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522 Australia
- Schizophrenia Research Institute, Sydney, NSW 2010 Australia
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Relationship between type 1 metabotropic glutamate receptors and cerebellar ataxia. J Neurol 2016; 263:2179-2187. [PMID: 27502082 DOI: 10.1007/s00415-016-8248-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/27/2016] [Accepted: 07/28/2016] [Indexed: 01/19/2023]
Abstract
Imaging of type 1 metabotropic glutamate receptor (mGluR1) has recently become possible using positron emission tomography (PET). We aimed to examine the relationship between mGluR1 and cerebellar ataxia. Families with spinocerebellar ataxia type 19/22 (SCA19/22) and SCA6, six patients with sporadic SCA, and 26 healthy subjects underwent PET using an mGluR1 radiotracer. Volumes-of-interest were placed on the anterior and posterior lobes and vermis. The binding potential (BPND) was calculated to estimate mGluR1 availability. A partial volume correction was applied to the BPND values. The Scale for the Assessment and Rating of Ataxia (SARA) score were measured. In each patient with SCA19/22 and SCA6, the anterior lobe showed the highest decrease rates in the BPND values, compared with healthy subjects. In the families with SCA19/22 and SCA6, the disease durations and SARA scores were shorter and lower, respectively, in the offspring, compared with the parents. However, the offspring paradoxically showed lower BPND values, especially in the anterior lobe, compared with the parents. The patients with sporadic SCA showed significantly lower BPND values in all subregions than healthy subjects. The BPND values significantly correlated with the SARA scores in all participants. In conclusion, these results showed a decrease in mGluR1 availability in patients with hereditary and sporadic SCA, a correlation between mGluR1 availability and degree of cerebellar ataxia, and paradoxical findings in two families. These results suggest the potential use of mGluR1 imaging as a specific biomarker of cerebellar ataxia.
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Gao SH, Wen HZ, Shen LL, Zhao YD, Ruan HZ. Activation of mGluR1 contributes to neuronal hyperexcitability in the rat anterior cingulate cortex via inhibition of HCN channels. Neuropharmacology 2016; 105:361-377. [DOI: 10.1016/j.neuropharm.2016.01.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/28/2016] [Accepted: 01/28/2016] [Indexed: 01/14/2023]
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Litim N, Morissette M, Di Paolo T. Metabotropic glutamate receptors as therapeutic targets in Parkinson's disease: An update from the last 5 years of research. Neuropharmacology 2016; 115:166-179. [PMID: 27055772 DOI: 10.1016/j.neuropharm.2016.03.036] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 12/21/2022]
Abstract
Disturbance of glutamate neurotransmission in Parkinson's disease (PD) and l-DOPA induced dyskinesia (LID) is well documented. This review focuses on advances during the past five years on pharmacological modulation of metabotropic glutamate (mGlu) receptors in relation to anti-parkinsonian activity, LID attenuation, and neuroprotection. Drug design and characterization have led to the development of orthosteric agonists binding the same site as glutamate and Positive and Negative Allosteric modulators (PAMs and NAMs) binding sites different from the orthosteric site and offering subtype selectivity. Inhibition of group I (mGlu1 and mGlu5) receptors with NAMs and activation of group II (mGlu2 and 3 receptors) and group III (mGlu 4, 7 and 8 receptors) with PAMs and orthosteric agonists have shown their potential to inhibit glutamate release and attenuate excitotoxicity. Earlier and recent studies have led to the development of mGlu5 receptors NAMs to reduce LID and for neuroprotection, mGlu3 receptor agonists for neuroprotection while mGlu4 receptor PAMs and agonists for antiparkinsonian effects and neuroprotection. Furthermore, homo- and heterodimers of mGlu receptors are documented and highlight the complexity of the functioning of these receptors. Research on partial allosteric modulators and biased mGlu receptor allosteric modulators offer new glutamatergic drugs with better therapeutic effects and less off target adverse activity. Thus these various mGlu receptor targets will enable the development of novel drugs with improved clinical effects for normalization of glutamate transmission, treat PD and LID relief. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Nadhir Litim
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada
| | - Thérèse Di Paolo
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada.
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Chefdeville A, Honnorat J, Hampe CS, Desestret V. Neuronal central nervous system syndromes probably mediated by autoantibodies. Eur J Neurosci 2016; 43:1535-52. [PMID: 26918657 DOI: 10.1111/ejn.13212] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/09/2016] [Accepted: 02/15/2016] [Indexed: 01/17/2023]
Abstract
In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients' antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies.
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Affiliation(s)
- Aude Chefdeville
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France
| | - Jérôme Honnorat
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
| | | | - Virginie Desestret
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
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Jarius S, Wildemann B. 'Medusa-head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 1: Anti-mGluR1, anti-Homer-3, anti-Sj/ITPR1 and anti-CARP VIII. J Neuroinflammation 2015; 12:166. [PMID: 26377085 PMCID: PMC4574226 DOI: 10.1186/s12974-015-0356-y] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/02/2015] [Indexed: 01/09/2023] Open
Abstract
Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa-head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.
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Affiliation(s)
- S Jarius
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
| | - B Wildemann
- Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, D-69120, Heidelberg, Germany.
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Neuregulin 1 signalling modulates mGluR1 function in mesencephalic dopaminergic neurons. Mol Psychiatry 2015; 20:959-73. [PMID: 25266126 DOI: 10.1038/mp.2014.109] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/01/2014] [Accepted: 07/23/2014] [Indexed: 02/07/2023]
Abstract
Neuregulin 1 (NRG1) is a trophic factor that has an essential role in the nervous system by modulating neurodevelopment, neurotransmission and synaptic plasticity. Despite the evidence that NRG1 and its receptors, ErbB tyrosine kinases, are expressed in mesencephalic dopaminergic nuclei and their functional alterations are reported in schizophrenia and Parkinson's disease, the role of NRG1/ErbB signalling in dopaminergic neurons remains unclear. Here we found that NRG1 selectively increases the metabotropic glutamate receptor 1 (mGluR1)-activated currents by inducing synthesis and trafficking to membrane of functional receptors and stimulates phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin (PI3K-Akt-mTOR) pathway, which is required for mGluR1 function. Notably, an endogenous NRG1/ErbB tone is necessary to maintain mGluR1 function, by preserving its surface membrane expression in dopaminergic neurons. Consequently, it enables striatal mGluR1-induced dopamine outflow in in vivo conditions. Our results identify a novel role of NRG1 in the dopaminergic neurons, whose functional alteration might contribute to devastating diseases, such as schizophrenia and Parkinson's disease.
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Discovery and biological evaluation of tetrahydrothieno[2,3-c]pyridine derivatives as selective metabotropic glutamate receptor 1 antagonists for the potential treatment of neuropathic pain. Eur J Med Chem 2015; 97:245-58. [DOI: 10.1016/j.ejmech.2015.04.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 03/30/2015] [Accepted: 04/28/2015] [Indexed: 12/31/2022]
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Kim M, Kim Y, Seo SH, Baek DJ, Min SJ, Keum G, Choo H. Synthesis and Biological Evaluation ofN3-Alkyl-Thienopyrimidin-4-Ones as mGluR1 Antagonists. B KOREAN CHEM SOC 2015. [DOI: 10.1002/bkcs.10283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Minjoo Kim
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
- Department of Chemistry, College of Natural Sciences; Sangmyung University; Seoul 110-743 Korea
| | - Youngjae Kim
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
- Department of Chemistry; Yonsei University; Seoul 120-749 Korea
| | - Seon Hee Seo
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
| | - Du-Jong Baek
- Department of Chemistry, College of Natural Sciences; Sangmyung University; Seoul 110-743 Korea
| | - Sun-Joon Min
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
- Department of Biological Chemistry; University of Science and Technology; Daejeon 305-350 Korea
| | - Gyochang Keum
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
- Department of Biological Chemistry; University of Science and Technology; Daejeon 305-350 Korea
| | - Hyunah Choo
- Center for Neuro-Medicine; Korea Institute of Science and Technology; Seoul 136-791 Korea
- Department of Biological Chemistry; University of Science and Technology; Daejeon 305-350 Korea
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Sleep slow wave-related homo and heterosynaptic LTD of intrathalamic GABAAergic synapses: involvement of T-type Ca2+ channels and metabotropic glutamate receptors. J Neurosci 2015; 35:64-73. [PMID: 25568103 DOI: 10.1523/jneurosci.2748-14.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Slow waves of non-REM sleep are suggested to play a role in shaping synaptic connectivity to consolidate recently acquired memories and/or restore synaptic homeostasis. During sleep slow waves, both GABAergic neurons of the nucleus reticularis thalami (NRT) and thalamocortical (TC) neurons discharge high-frequency bursts of action potentials mediated by low-threshold calcium spikes due to T-type Ca(2+) channel activation. Although such activity of the intrathalamic network characterized by high-frequency firing and calcium influx is highly suited to modify synaptic efficacy, very little is still known about its consequences on intrathalamic synapse strength. Combining in vitro electrophysiological recordings and calcium imaging, here we show that the inhibitory GABAergic synapses between NRT and TC neurons of the rat somatosensory nucleus develop a long-term depression (I-LTD) when challenged by a stimulation paradigm that mimics the thalamic network activity occurring during sleep slow waves. The mechanism underlying this plasticity presents unique features as it is both heterosynaptic and homosynaptic in nature and requires Ca(2+) entry selectively through T-type Ca(2+) channels and activation of the Ca(2+)-activated phosphatase, calcineurin. We propose that during slow-wave sleep the tight functional coupling between GABAA receptors, calcineurin, and T-type Ca(2+) channels will elicit LTD of the activated GABAergic synapses when coupled with concomitant activation of metabotropic glutamate receptors postsynaptic to cortical afferences. This I-LTD may be a key element involved in the reshaping of the somatosensory information pathway during sleep.
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Cho GH, Kim T, Son WS, Seo SH, Min SJ, Cho YS, Keum G, Jeong KS, Koh HY, Lee J, Pae AN. Synthesis and biological evaluation of aryl isoxazole derivatives as metabotropic glutamate receptor 1 antagonists: A potential treatment for neuropathic pain. Bioorg Med Chem Lett 2015; 25:1324-8. [DOI: 10.1016/j.bmcl.2015.01.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/24/2014] [Accepted: 01/19/2015] [Indexed: 10/24/2022]
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Shostak Y, Wenger A, Mavity-Hudson J, Casagrande VA. Metabotropic glutamate receptor 5 shows different patterns of localization within the parallel visual pathways in macaque and squirrel monkeys. Eye Brain 2014; 6:29-43. [PMID: 25774086 PMCID: PMC4356996 DOI: 10.2147/eb.s51817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Glutamate is used as an excitatory neurotransmitter by the koniocellular (K), magnocellular (M), and parvocellular (P) pathways to transfer signals from the primate lateral geniculate nucleus (LGN) to primary visual cortex (V1). Glutamate acts through both fast ionotropic receptors, which appear to carry the main sensory message, and slower, modulatory metabotropic receptors (mGluRs). In this study, we asked whether mGluR5 relates in distinct ways to the K, M, and P LGN axons in V1. To answer this question, we used light microscopic immunocytochemistry and preembedding electron microscopic immunogold labeling to determine the localization of mGluR5 within the layers of V1 in relation to the K, M, and P pathways in macaque and squirrel monkeys. These pathways were labeled separately via wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injections targeting the LGN layers. mGluR5 is of interest because it: 1) has been shown to be expressed in the thalamic input layers; 2) appears to be responsible for some types of oscillatory firing, which could be important in the binding of visual features; and 3) has been associated with a number of sensory-motor gating-related pathologies, including schizophrenia and autism. Our results demonstrated the presence of mGluR5 in the neuropil of all V1 layers. This protein was lowest in IVCα (M input) and the infragranular layers. In layer IVC, mGluR5 also was found postsynaptic to about 30% of labeled axons, but the distribution was uneven, such that postsynaptic mGluR5 label tended to occur opposite smaller (presumed P), and not larger (presumed M) axon terminals. Only in the K pathway in layer IIIB, however, was mGluR5 always found in the axon terminals themselves. The presence of mGluR5 in K axons and not in M and P axons, and the presence of mGluR5 postsynaptic mainly to smaller P and not larger M axons suggest that the response to the release of glutamate is modulated in distinct ways within and between the parallel visual pathways of primates.
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Affiliation(s)
- Yuri Shostak
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA ; Foreign Trade Unitary Enterprise, Minsk, Belarus
| | - Ashley Wenger
- Undergraduate Neuroscience Program, Vanderbilt University, Nashville, TN, USA
| | - Julia Mavity-Hudson
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Vivien A Casagrande
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA ; Department of Psychology, Vanderbilt University, Nashville, TN, USA ; Department of Ophthalmology and Visual Sciences, Vanderbilt University, Nashville, TN, USA
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Lu Y. Metabotropic glutamate receptors in auditory processing. Neuroscience 2014; 274:429-45. [PMID: 24909898 PMCID: PMC5299851 DOI: 10.1016/j.neuroscience.2014.05.057] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/03/2014] [Accepted: 05/28/2014] [Indexed: 11/24/2022]
Abstract
As the major excitatory neurotransmitter used in the vertebrate brain, glutamate activates ionotropic and metabotropic glutamate receptors (mGluRs), which mediate fast and slow neuronal actions, respectively. Important modulatory roles of mGluRs have been shown in many brain areas, and drugs targeting mGluRs have been developed for the treatment of brain disorders. Here, I review studies on mGluRs in the auditory system. Anatomical expression of mGluRs in the cochlear nucleus has been well characterized, while data for other auditory nuclei await more systematic investigations at both the light and electron microscopy levels. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the lower auditory brainstem in both mammals and birds. These in vitro physiological studies have revealed that mGluRs participate in neurotransmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between excitation and inhibition in a variety of auditory structures. However, very few in vivo physiological studies on mGluRs in auditory processing have been undertaken at the systems level. Many questions regarding the essential roles of mGluRs in auditory processing still remain unanswered and more rigorous basic research is warranted.
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Affiliation(s)
- Y Lu
- Department of Anatomy and Neurobiology, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA.
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Nickols HH, Conn PJ. Development of allosteric modulators of GPCRs for treatment of CNS disorders. Neurobiol Dis 2014; 61:55-71. [PMID: 24076101 PMCID: PMC3875303 DOI: 10.1016/j.nbd.2013.09.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/13/2013] [Accepted: 09/17/2013] [Indexed: 12/14/2022] Open
Abstract
The discovery of allosteric modulators of G protein-coupled receptors (GPCRs) provides a promising new strategy with potential for developing novel treatments for a variety of central nervous system (CNS) disorders. Traditional drug discovery efforts targeting GPCRs have focused on developing ligands for orthosteric sites which bind endogenous ligands. Allosteric modulators target a site separate from the orthosteric site to modulate receptor function. These allosteric agents can either potentiate (positive allosteric modulator, PAM) or inhibit (negative allosteric modulator, NAM) the receptor response and often provide much greater subtype selectivity than orthosteric ligands for the same receptors. Experimental evidence has revealed more nuanced pharmacological modes of action of allosteric modulators, with some PAMs showing allosteric agonism in combination with positive allosteric modulation in response to endogenous ligand (ago-potentiators) as well as "bitopic" ligands that interact with both the allosteric and orthosteric sites. Drugs targeting the allosteric site allow for increased drug selectivity and potentially decreased adverse side effects. Promising evidence has demonstrated potential utility of a number of allosteric modulators of GPCRs in multiple CNS disorders, including neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, as well as psychiatric or neurobehavioral diseases such as anxiety, schizophrenia, and addiction.
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Key Words
- (+)-6-(2,4-dimethylphenyl)-2-ethyl-6,7-dihydrobenzo[d]oxazol-4(5H)-one
- (1-(4-cyano-4-(pyridine-2-yl)piperidine-1-yl)methyl-4-oxo-4H-quinolizine-3-carboxylic acid)
- (1S,2S)-N(1)-(3,4-dichlorophenyl)cyclohexane-1,2-dicarboxamide
- (1S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid
- (3,4-dihydro-2H-pyrano[2,3]b quinolin-7-yl)(cis-4-methoxycyclohexyl) methanone
- (3aS,5S,7aR)-methyl 5-hydroxy-5-(m-tolylethynyl)octahydro-1H-indole-1-carboxylate
- 1-(1′-(2-methylbenzyl)-1,4′-bipiperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one
- 1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- 2-(2-(3-methoxyphenyl)ethynyl)-5-methylpyridine
- 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1Himidazol-4-yl)ethynyl)pyridine
- 2-methyl-6-(2-phenylethenyl)pyridine
- 2-methyl-6-(phenylethynyl)-pyridine
- 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide
- 3-cyclohexyl-5-fluoro-6-methyl-7-(2-morpholin-4-ylethoxy)-4H-chromen-4-one
- 3[(2-methyl-1,3-thiazol-4-yl)ethylnyl]pyridine
- 4-((E)-styryl)-pyrimidin-2-ylamine
- 4-[1-(2-fluoropyridin-3-yl)-5-methyl-1H-1,2,3-triazol-4-yl]-N-isopropyl-N-methyl-3,6-dihydropyridine-1(2H)-carboxamide
- 4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine
- 5-methyl-6-(phenylethynyl)-pyridine
- 5MPEP
- 6-(4-methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one
- 6-OHDA
- 6-hydroxydopamine
- 6-methyl-2-(phenylazo)-3-pyridinol
- 77-LH-28-1
- 7TMR
- AC-42
- ACPT-1
- AChE
- AD
- ADX71743
- AFQ056
- APP
- Allosteric modulator
- Alzheimer's disease
- BINA
- BQCA
- CDPPB
- CFMMC
- CNS
- CPPHA
- CTEP
- DA
- DFB
- DHPG
- Drug discovery
- ERK1/2
- FMRP
- FTIDC
- FXS
- Fragile X syndrome
- GABA
- GPCR
- JNJ16259685
- L-AP4
- L-DOPA
- Lu AF21934
- Lu AF32615
- M-5MPEP
- MMPIP
- MPEP
- MPTP
- MTEP
- Metabotropic glutamate receptor
- Muscarinic acetylcholine receptor
- N-[4-chloro-2[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]phenyl]-2-hydrobenzamide
- N-methyl-d-aspartate
- N-phenyl-7-(hydroxylimino)cyclopropa[b]chromen-1a-carboxamide
- NAM
- NMDA
- PAM
- PCP
- PD
- PD-LID
- PET
- PHCCC
- PQCA
- Parkinson's disease
- Parkinson's disease levodopa-induced dyskinesia
- SAM
- SIB-1757
- SIB-1893
- TBPB
- [(3-fluorophenyl)methylene]hydrazone-3-fluorobenzaldehyde
- acetylcholinesterase
- amyloid precursor protein
- benzylquinolone carboxylic acid
- central nervous system
- dihydroxyphenylglycine
- dopamine
- extracellular signal-regulated kinase 1/2
- fragile X mental retardation protein
- l-(+)-2-amino-4-phosphonobutyric acid
- l-3,4-dihydroxyphenylalanine
- mGlu
- metabotropic glutamate receptor
- negative allosteric modulator
- phencyclidine
- positive allosteric modulator
- positron emission tomography
- potassium 30-([(2-cyclopentyl-6-7-dimethyl-1-oxo-2,3-dihydro-1H-inden-5yl)oxy]methyl)biphenyl l-4-carboxylate
- seven transmembrane receptor
- silent allosteric modulator
- γ-aminobutyric acid
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Affiliation(s)
- Hilary Highfield Nickols
- Division of Neuropathology, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
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Salt TE, Jones HE, Copeland CS, Sillito AM. Function of mGlu1 receptors in the modulation of nociceptive processing in the thalamus. Neuropharmacology 2013; 79:405-11. [PMID: 24373900 PMCID: PMC3989022 DOI: 10.1016/j.neuropharm.2013.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/23/2013] [Accepted: 12/16/2013] [Indexed: 01/07/2023]
Abstract
As postsynaptic metabotropic subtype 1 (mGlu1) receptors are present in the thalamus, we have investigated the effect of potentiating and antagonising mGlu1 receptors on responses of thalamic neurones to noxious sensory stimulation. Extracellular recordings were made in vivo with multi-barrel iontophoretic electrodes from single neurones in the thalamus of urethane-anaesthetised rats. Responses to iontophoretic applications of the Group I mGlu agonist 3,5-dihydroxy-phenylglycine (DHPG) were selectively potentiated by co-application of the mGlu1 positive allosteric modulator Ro67-4853, whereas they were selectively reduced upon co-application of the mGlu1 receptor orthosteric antagonist LY367385. This indicates that thalamic DHPG responses are mediated primarily via mGlu1 receptors, consistent with the high postsynaptic levels of this receptor in the thalamus. Furthermore, potentiation of DHPG responses by Ro67-4853 were greater when the initial DHPG response was of a low magnitude. Ro67-4853 also potentiated responses of thalamic neurones to noxious thermal stimulation, whilst having little effect on the baseline activity of nociceptive neurones. By contrast, nociceptive responses were reduced by LY367385. In a further series of experiments we found that inactivation of somatosensory cortex by cooling resulted in a reduction of thalamic nociceptive responses. These results underline the importance of mGlu1 receptors in the processing of sensory information in the thalamus, particularly with respect to nociceptive responses. Furthermore, the involvement of mGlu1 receptors may reflect the activity of descending cortico-thalamic afferents. Pharmacological potentiation of mGlu1 receptors enhances nociceptive responses of thalamic neurones. Antagonism of mGlu1 receptors reduces nociceptive responses of thalamic neurones. Inactivation of somatosensory cortex reduces nociceptive responses of thalamic neurones. This suggests a role for mGlu1 receptors and cortico-thalamic pathways in nociceptive processing.
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Affiliation(s)
- T E Salt
- Visual Neuroscience, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom.
| | - H E Jones
- Visual Neuroscience, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - C S Copeland
- Visual Neuroscience, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - A M Sillito
- Visual Neuroscience, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom
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mGluR1/5 receptor densities in the brains of alcoholic subjects: a whole-hemisphere autoradiography study. Psychiatry Res 2013; 212:245-50. [PMID: 23149043 DOI: 10.1016/j.pscychresns.2012.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 03/24/2012] [Accepted: 04/08/2012] [Indexed: 12/17/2022]
Abstract
Increased glutamatergic neurotransmission and hyper-excitability during alcoholic withdrawal and abstinence are associated with increased risk for relapse, in addition to compensatory changes in the glutamatergic system during chronic alcohol intake. Type 5 metabotropic glutamate receptor (mGlur5) is abundant in brain regions known to be involved in drug reinforcement, yet very little has been published on mGluR1/5 expression in alcoholics. We evaluated the densities of mGluR1/5 binding in the hippocampus and striatum of post-mortem human brains by using [(3)H]Quisqualic acid as a radioligand in whole hemispheric autoradiography of Cloninger type 1 (n=9) and 2 (n=8) alcoholics and healthy controls (n=10). We observed a 30-40% higher mGluR1/5 binding density in the CA2 area of hippocampus in type 1 alcoholics when compared with either type 2 alcoholics or healthy subjects. Although preliminary, and from a relatively small number of subjects from these diagnostic groups, these results suggest that the mGluR1/5 receptors may be increased in type 1 alcoholics in certain brain areas.
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50
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Serum carnitine levels and levocarnitine supplementation in institutionalized Huntington's disease patients. Neurol Sci 2013; 34:93-8. [PMID: 22294053 DOI: 10.1007/s10072-012-0952-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 01/13/2012] [Indexed: 12/17/2022]
Abstract
Along with antioxidant properties, carnitine is an important regulator of lipid metabolism in humans. While beneficial effects of carnitine have been demonstrated in animal models of Huntington's disease (HD), metabolism of carnitine has not been studied in humans with this illness. In this retrospective database review from 23 patients admitted to a HD-specialized nursing home unit, we found a relatively high prevalence of hypocarnitinemia (6 cases, 26%). Our review suggests that catabolism and chronic valproate use predisposed our patients to develop hypocarnitinemia. The patients with low serum carnitine levels who received levocarnitine supplementation, during a mean period of 7.3 months, showed improvement in motor, cognitive and behavioral measures. We hypothesize that observed improvement related to the resolution of reversible metabolic encephalopathy and myopathy associated with secondary carnitine deficiency. In conclusion, notwithstanding its limitations, this is the first study to report measurements of carnitine levels in HD patients, revealing relatively high prevalence of hypocarnitinemia in our population. Our findings suggest that HD patients with hypocarnitinemia may benefit from low-dose levocarnitine supplementation. Further studies of carnitine metabolism and supplementation in HD patients are warranted.
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