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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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2
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Zimmermann M, Minuzzi L, Aliaga Aliaga A, Guiot MC, Hall JA, Soucy JP, Massarweh G, El Mestikawy S, Rosa-Neto P, Kobayashi E. Reduced Metabotropic Glutamate Receptor Type 5 Availability in the Epileptogenic Hippocampus: An in vitro Study. Front Neurol 2022; 13:888479. [PMID: 35937057 PMCID: PMC9355376 DOI: 10.3389/fneur.2022.888479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/02/2022] [Indexed: 11/23/2022] Open
Abstract
Abnormalities in the expression of metabotropic glutamate receptor type 5 (mGluR5) have been observed in the hippocampus of patients with drug-resistant mesial Temporal Lobe Epilepsy (mTLE). Ex-vivo studies in mTLE hippocampal surgical specimens have shown increased mGluR5 immunoreactivity, while in vivo whole brain imaging using positron emission tomography (PET) demonstrated reduced hippocampal mGluR5 availability. To further understand mGluR5 abnormalities in mTLE, we performed a saturation autoradiography study with [3H]ABP688 (a negative mGluR5 allosteric modulator). We aimed to evaluate receptor density (Bmax) and dissociation constants (KD) in hippocampal mTLE surgical specimens and in non-epilepsy hippocampi from necropsy controls. mTLE specimens showed a 43.4% reduction in receptor density compared to control hippocampi, which was independent of age, sex and KD (multiple linear regression analysis). There was no significant difference in KD between the groups, which suggests that the decreased mGluR5 availability found in vivo with PET cannot be attributed to reduced affinity between ligand and binding site. The present study supports that changes within the epileptogenic tissue include mGluR5 internalization or conformational changes that reduce [3H]ABP688 binding, as previously suggested in mTLE patients studied in vivo.
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Affiliation(s)
- Maria Zimmermann
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- Translational Neuroimaging Laboratory, Douglas Research Institute, McGill University, Montréal, QC, Canada
| | - Luciano Minuzzi
- Translational Neuroimaging Laboratory, Douglas Research Institute, McGill University, Montréal, QC, Canada
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| | - Arturo Aliaga Aliaga
- Translational Neuroimaging Laboratory, Douglas Research Institute, McGill University, Montréal, QC, Canada
- PET Unit, McConnell Brain Imaging Centre, Montréal, QC, Canada
| | | | - Jeffery A. Hall
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Jean-Paul Soucy
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- PET Unit, McConnell Brain Imaging Centre, Montréal, QC, Canada
| | | | - Salah El Mestikawy
- Department of Psychiatry, Douglas Research Institute, McGill University, Montréal, QC, Canada
| | - Pedro Rosa-Neto
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- Translational Neuroimaging Laboratory, Douglas Research Institute, McGill University, Montréal, QC, Canada
| | - Eliane Kobayashi
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- *Correspondence: Eliane Kobayashi
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3
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Turati J, Rudi J, Beauquis J, Carniglia L, López Couselo F, Saba J, Caruso C, Saravia F, Lasaga M, Durand D. A metabotropic glutamate receptor 3 (mGlu3R) isoform playing neurodegenerative roles in astrocytes is prematurely up-regulated in an Alzheimer's model. J Neurochem 2022; 161:366-382. [PMID: 35411603 DOI: 10.1111/jnc.15610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/14/2022] [Accepted: 03/23/2022] [Indexed: 12/26/2022]
Abstract
Subtype 3 metabotropic glutamate receptor (mGlu3R) displays a broad range of neuroprotective effects. We previously demonstrated that mGlu3R activation in astrocytes protects hippocampal neurons from Aβ neurotoxicity through stimulation of both neurotrophin release and Aβ uptake. Alternative-spliced variants of mGlu3R were found in human brains. The most prevalent variant, mGlu3Δ4, lacks exon 4 encoding the transmembrane domain and can inhibit ligand binding to mGlu3R. To date, neither its role in neurodegenerative disorders nor its endogenous expression in CNS cells has been addressed. The present paper describes for the first time an association between altered hippocampal expression of mGlu3Δ4 and Alzheimer's disease (AD) in the preclinical murine model PDAPP-J20, as well as a deleterious effect of mGlu3Δ4 in astrocytes. As assessed by western blot, hippocampal mGlu3R levels progressively decreased with age in PDAPP-J20 mice. On the contrary, mGlu3Δ4 levels were drastically increased with aging in nontransgenic mice, but prematurely over-expressed in 5-month-old PDAPP-J20-derived hippocampi, prior to massive senile plaque deposition. Also, we found that mGlu3Δ4 co-precipitated with mGlu3R mainly in 5-month-old PDAPP-J20 mice. We further showed by western blot that primary cultured astrocytes and neurons expressed mGlu3Δ4, whose levels were reduced by Aβ, thereby discouraging a causal effect of Aβ on mGlu3Δ4 induction. However, heterologous expression of mGlu3Δ4 in astrocytes induced cell death, inhibited mGlu3R expression, and prevented mGlu3R-dependent Aβ glial uptake. Indeed, mGlu3Δ4 promoted neurodegeneration in neuron-glia co-cultures. These results provide evidence of an inhibitory role of mGlu3Δ4 in mGlu3R-mediated glial neuroprotective pathways, which may lie behind AD onset.
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Affiliation(s)
- Juan Turati
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Julieta Rudi
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.,IATIMET Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Juan Beauquis
- Laboratorio de Neurobiología del Envejecimiento, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lila Carniglia
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Federico López Couselo
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Julieta Saba
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Carla Caruso
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Flavia Saravia
- Laboratorio de Neurobiología del Envejecimiento, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mercedes Lasaga
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Daniela Durand
- INBIOMED Instituto de Investigaciones Biomédicas UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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Morland C, Nordengen K. N-Acetyl-Aspartyl-Glutamate in Brain Health and Disease. Int J Mol Sci 2022; 23:ijms23031268. [PMID: 35163193 PMCID: PMC8836185 DOI: 10.3390/ijms23031268] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/04/2023] Open
Abstract
N-acetyl-aspartyl-glutamate (NAAG) is the most abundant dipeptide in the brain, where it acts as a neuromodulator of glutamatergic synapses by activating presynaptic metabotropic glutamate receptor 3 (mGluR3). Recent data suggest that NAAG is selectively localized to postsynaptic dendrites in glutamatergic synapses and that it works as a retrograde neurotransmitter. NAAG is released in response to glutamate and provides the postsynaptic neuron with a feedback mechanisms to inhibit excessive glutamate signaling. A key regulator of synaptically available NAAG is rapid degradation by the extracellular enzyme glutamate carboxypeptidase II (GCPII). Increasing endogenous NAAG—for instance by inhibiting GCPII—is a promising treatment option for many brain disorders where glutamatergic excitotoxicity plays a role. The main effect of NAAG occurs through increased mGluR3 activation and thereby reduced glutamate release. In the present review, we summarize the transmitter role of NAAG and discuss the involvement of NAAG in normal brain physiology. We further present the suggested roles of NAAG in various neurological and psychiatric diseases and discuss the therapeutic potential of strategies aiming to enhance NAAG levels.
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Affiliation(s)
- Cecilie Morland
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, The Faculty of Mathematics and Natural Sciences, University of Oslo, 1068 Oslo, Norway
- Correspondence: (C.M.); (K.N.); Tel.: +47-22844937; (C.M.); +47-23073580 (K.N.)
| | - Kaja Nordengen
- Department of Neurology, Oslo University Hospital, 0424 Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
- Correspondence: (C.M.); (K.N.); Tel.: +47-22844937; (C.M.); +47-23073580 (K.N.)
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5
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Zhang CY, Xiao X, Zhang Z, Hu Z, Li M. An alternative splicing hypothesis for neuropathology of schizophrenia: evidence from studies on historical candidate genes and multi-omics data. Mol Psychiatry 2022; 27:95-112. [PMID: 33686213 DOI: 10.1038/s41380-021-01037-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 01/08/2021] [Accepted: 01/22/2021] [Indexed: 01/31/2023]
Abstract
Alternative splicing of schizophrenia risk genes, such as DRD2, GRM3, and DISC1, has been extensively described. Nevertheless, the alternative splicing characteristics of the growing number of schizophrenia risk genes identified through genetic analyses remain relatively opaque. Recently, transcriptomic analyses in human brains based on short-read RNA-sequencing have discovered many "local splicing" events (e.g., exon skipping junctions) associated with genetic risk of schizophrenia, and further molecular characterizations have identified novel spliced isoforms, such as AS3MTd2d3 and ZNF804AE3E4. In addition, long-read sequencing analyses of schizophrenia risk genes (e.g., CACNA1C and NRXN1) have revealed multiple previously unannotated brain-abundant isoforms with therapeutic potentials, and functional analyses of KCNH2-3.1 and Ube3a1 have provided examples for investigating such spliced isoforms in vitro and in vivo. These findings suggest that alternative splicing may be an essential molecular mechanism underlying genetic risk of schizophrenia, however, the incomplete annotations of human brain transcriptomes might have limited our understanding of schizophrenia pathogenesis, and further efforts to elucidate these transcriptional characteristics are urgently needed to gain insights into the illness-correlated brain physiology and pathology as well as to translate genetic discoveries into novel therapeutic targets.
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Affiliation(s)
- Chu-Yi Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xiao Xiao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Zhuohua Zhang
- Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Zhonghua Hu
- Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China. .,Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, Hunan, China. .,Eye Center of Xiangya Hospital and Hunan Key Laboratory of Ophthalmology, Central South University, Changsha, Hunan, China. .,National Clinical Research Center on Mental Disorders, Changsha, Hunan, China.
| | - Ming Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China. .,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China. .,KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
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6
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Turati J, Ramírez D, Carniglia L, Saba J, Caruso C, Quarleri J, Durand D, Lasaga M. Antioxidant and neuroprotective effects of mGlu3 receptor activation on astrocytes aged in vitro. Neurochem Int 2020; 140:104837. [PMID: 32858088 DOI: 10.1016/j.neuint.2020.104837] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 01/07/2023]
Abstract
Astrocytes play a key role by providing antioxidant support to nearby neurons under oxidative stress. We have previously demonstrated that in vitro astroglial subtype 3 metabotropic glutamate receptor (mGlu3R) is neuroprotective. However, its role during aging has been poorly explored. Our study aimed to determine whether LY379268, an mGlu3R agonist, exerts an antioxidant effect on aged cultured rat astrocytes. Aged cultured astrocytes obtained after 9-weeks (9w) in vitro were positive for β-galactosidase stain, showed decreased mGlu3R and glutathione (GSH) levels and superoxide dismutase (SOD) activity, while nuclear erythroid factor 2 (Nrf2) protein levels, reactive oxygen species (ROS) production and apoptosis were increased. Treatment of 9w astrocytes with LY379268 resulted in an increase in mGlu3R and Nrf2 protein levels and SOD activity, and decreased mitochondrial ROS levels and apoptosis. mGlu3R activation in aged astrocytes also prevented hippocampal neuronal death induced by Aβ1-42 in co-culture assays. We conclude that activation of mGlu3R in aged astrocytes had an anti-oxidant effect and protected hippocampal neurons against Aβ-induced neurotoxicity. The present study suggests mGlu3R activation in aging astrocytes as a therapeutic strategy to slow down age-associated neurodegeneration.
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Affiliation(s)
- Juan Turati
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Delia Ramírez
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Lila Carniglia
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Julieta Saba
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Carla Caruso
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Jorge Quarleri
- INBIRS - Instituto de Investigaciones Biomédicas en Retrovirus y SIDA, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Daniela Durand
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Mercedes Lasaga
- INBIOMED - Instituto de Investigaciones Biomédicas, UBA-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
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Li Q, Jin R, Zhang S, Sun X, Wu J. Group II metabotropic glutamate receptor agonist promotes retinal ganglion cell survival by reducing neuronal excitotoxicity in a rat chronic ocular hypertension model. Neuropharmacology 2020; 170:108016. [PMID: 32101763 DOI: 10.1016/j.neuropharm.2020.108016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/24/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Glaucoma, the second leading cause of irreversible blindness worldwide, is characterized by the selective death of retinal ganglion cells (RGCs). The group II metabotropic glutamate receptor (mGluR II) activation has been linked to RGC survival, however, the mechanism by which it promotes neuronal survival remains poorly defined. In the present work, we show that extracellular application of LY341495, an mGluR II antagonist could increase the RGC firing frequency, suggesting that activation of mGluR II by endogenously released glutamate could modulate RGC excitability. LY354740, an mGluR II agonist, significantly decreased RGC excitability and the reduced presynaptic excitatory inputs and post-synaptic Ca2+-permeable currents mediated the LY354740-induced effects. By using a well-characterized in vivo male Sprague-Dawley rat glaucoma model, we further demonstrate that in the early stage of experimental glaucoma, the expression of mGluR II dimer-formed protein was significantly reduced, and pre-activation of mGluR II by intravitreal injection of LY354740 before establishment of the glaucoma model could effectively reduce excitatory inputs, thereby reversing hyperexcitability induced by elevated intraocular pressure. Furthermore, LY354740 could increase the expression level of brain-derived neurotrophic factor in the glaucomatous retinas, further protecting RGCs. Our study indicates that the abnormal expression of mGluR II may accelerate RGC apoptosis in glaucoma, and demonstrates that mGluR II agonist LY354740 can be used as a novel method to counter RGC apoptosis in glaucoma.
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Affiliation(s)
- Qian Li
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Ruiri Jin
- Department of Gastroenterology, Songjiang Central Hospital, Shanghai, 201600, China
| | - Shenghai Zhang
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
| | - Xinghuai Sun
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
| | - Jihong Wu
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
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8
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Imbriglio T, Verhaeghe R, Martinello K, Pascarelli MT, Chece G, Bucci D, Notartomaso S, Quattromani M, Mascio G, Scalabrì F, Simeone A, Maccari S, Del Percio C, Wieloch T, Fucile S, Babiloni C, Battaglia G, Limatola C, Nicoletti F, Cannella M. Developmental abnormalities in cortical GABAergic system in mice lacking mGlu3 metabotropic glutamate receptors. FASEB J 2019; 33:14204-14220. [PMID: 31665922 DOI: 10.1096/fj.201901093rrr] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Polymorphic variants of the gene encoding for metabotropic glutamate receptor 3 (mGlu3) are linked to schizophrenia. Because abnormalities of cortical GABAergic interneurons lie at the core of the pathophysiology of schizophrenia, we examined whether mGlu3 receptors influence the developmental trajectory of cortical GABAergic transmission in the postnatal life. mGlu3-/- mice showed robust changes in the expression of interneuron-related genes in the prefrontal cortex (PFC), including large reductions in the expression of parvalbumin (PV) and the GluN1 subunit of NMDA receptors. The number of cortical cells enwrapped by perineuronal nets was increased in mGlu3-/- mice, suggesting that mGlu3 receptors shape the temporal window of plasticity of PV+ interneurons. Electrophysiological measurements of GABAA receptor-mediated responses revealed a more depolarized reversal potential of GABA currents in the somata of PFC pyramidal neurons in mGlu3-/- mice at postnatal d 9 associated with a reduced expression of the K+/Cl- symporter. Finally, adult mGlu3-/- mice showed lower power in electroencephalographic rhythms at 1-45 Hz in quiet wakefulness as compared with their wild-type counterparts. These findings suggest that mGlu3 receptors have a strong impact on the development of cortical GABAergic transmission and cortical neural synchronization mechanisms corroborating the concept that genetic variants of mGlu3 receptors may predispose to psychiatric disorders.-Imbriglio, T., Verhaeghe, R., Martinello, K., Pascarelli, M. T., Chece, G., Bucci, D., Notartomaso, S., Quattromani, M., Mascio, G., Scalabrì, F., Simeone, A., Maccari, S., Del Percio, C., Wieloch, T., Fucile, S., Babiloni, C., Battaglia, G., Limatola, C., Nicoletti, F., Cannella, M. Developmental abnormalities in cortical GABAergic system in mice lacking mGlu3 metabotropic glutamate receptors.
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Affiliation(s)
- Tiziana Imbriglio
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Remy Verhaeghe
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Katiuscia Martinello
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Maria Teresa Pascarelli
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Oasi Research Institute - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Troina, Italy
| | - Giuseppina Chece
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Domenico Bucci
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Serena Notartomaso
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Miriana Quattromani
- Laboratory for Experimental Brain Research, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Giada Mascio
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Francesco Scalabrì
- Istituto di Ricerca Biologia Molecolare (IRBM) Science Park S.p.A., Pomezia, Rome, Italy
| | - Antonio Simeone
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", Centro Nazionale Ricerche (CNR), Naples, Italy
| | - Stefania Maccari
- Department of Science and Medical-Surgical Biotechnology, University Sapienza of Rome, Rome, Italy.,University of Lille, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Claudio Del Percio
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Tadeusz Wieloch
- Oasi Research Institute - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Troina, Italy
| | - Sergio Fucile
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Claudio Babiloni
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Hospital San Raffaele Cassino, Cassino, Italy
| | - Giuseppe Battaglia
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Milena Cannella
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
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Jin LE, Wang M, Galvin VC, Lightbourne TC, Conn PJ, Arnsten AFT, Paspalas CD. mGluR2 versus mGluR3 Metabotropic Glutamate Receptors in Primate Dorsolateral Prefrontal Cortex: Postsynaptic mGluR3 Strengthen Working Memory Networks. Cereb Cortex 2019; 28:974-987. [PMID: 28108498 DOI: 10.1093/cercor/bhx005] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Indexed: 01/06/2023] Open
Abstract
The newly evolved circuits in layer III of primate dorsolateral prefrontal cortex (dlPFC) generate the neural representations that subserve working memory. These circuits are weakened by increased cAMP-K+ channel signaling, and are a focus of pathology in schizophrenia, aging, and Alzheimer's disease. Cognitive deficits in these disorders are increasingly associated with insults to mGluR3 metabotropic glutamate receptors, while reductions in mGluR2 appear protective. This has been perplexing, as mGluR3 has been considered glial receptors, and mGluR2 and mGluR3 have been thought to have similar functions, reducing glutamate transmission. We have discovered that, in addition to their astrocytic expression, mGluR3 is concentrated postsynaptically in spine synapses of layer III dlPFC, positioned to strengthen connectivity by inhibiting postsynaptic cAMP-K+ channel actions. In contrast, mGluR2 is principally presynaptic as expected, with only a minor postsynaptic component. Functionally, increase in the endogenous mGluR3 agonist, N-acetylaspartylglutamate, markedly enhanced dlPFC Delay cell firing during a working memory task via inhibition of cAMP signaling, while the mGluR2 positive allosteric modulator, BINA, produced an inverted-U dose-response on dlPFC Delay cell firing and working memory performance. These data illuminate why insults to mGluR3 would erode cognitive abilities, and support mGluR3 as a novel therapeutic target for higher cognitive disorders.
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Affiliation(s)
- Lu E Jin
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Min Wang
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Veronica C Galvin
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Taber C Lightbourne
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Peter Jeffrey Conn
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt UniversityMedical Center, Nashville, TN 37232-0697, USA
| | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
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Nicoletti F, Orlando R, Di Menna L, Cannella M, Notartomaso S, Mascio G, Iacovelli L, Matrisciano F, Fazio F, Caraci F, Copani A, Battaglia G, Bruno V. Targeting mGlu Receptors for Optimization of Antipsychotic Activity and Disease-Modifying Effect in Schizophrenia. Front Psychiatry 2019; 10:49. [PMID: 30890967 PMCID: PMC6413697 DOI: 10.3389/fpsyt.2019.00049] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/23/2019] [Indexed: 01/03/2023] Open
Abstract
Metabotropic glutamate (mGlu) receptors are considered as candidate drug targets for the treatment of schizophrenia. These receptors form a family of eight subtypes (mGlu1 to -8), of which mGlu1 and -5 are coupled to Gq/11, and all other subtypes are coupled to Gi/o. Here, we discuss the possibility that selective ligands of individual mGlu receptor subtypes may be effective in controlling the core symptoms of schizophrenia, and, in some cases, may impact mechanisms underlying the progression of the disorder. Recent evidence indicates that activation of mGlu1 receptors inhibits dopamine release in the meso-striatal system. Hence, selective positive allosteric modulators (PAMs) of mGlu1 receptors hold promise for the treatment of positive symptoms of schizophrenia. mGlu5 receptors are widely expressed in the CNS and regulate the activity of cells that are involved in the pathophysiology of schizophrenia, such as cortical GABAergic interneurons and microglial cells. mGlu5 receptor PAMs are under development for the treatment of schizophrenia and cater the potential to act as disease modifiers by restraining neuroinflammation. mGlu2 receptors have attracted considerable interest because they negatively modulate 5-HT2A serotonin receptor signaling in the cerebral cortex. Both mGlu2 receptor PAMs and orthosteric mGlu2/3 receptor agonists display antipsychotic-like activity in animal models, and the latter drugs are inactive in mice lacking mGlu2 receptors. So far, mGlu3 receptors have been left apart as drug targets for schizophrenia. However, activation of mGlu3 receptors boosts mGlu5 receptor signaling, supports neuronal survival, and drives microglial cells toward an antiinflammatory phenotype. This strongly encourages research of mGlu3 receptors in schizophrenia. Finally, preclical studies suggest that mGlu4 receptors might be targeted by novel antipsychotic drugs, whereas studies of mGlu7 and mGlu8 receptors in animal models of psychosis are still at their infancy.
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Affiliation(s)
- Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - Rosamaria Orlando
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | | | | | | | | | - Luisa Iacovelli
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Francesco Matrisciano
- Department of Psychiatry, The Psychiatric Institute, College of Medicine, University of Illinois, Chicago, IL, United States
| | | | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute (IRCCS), Troina, Italy
| | - Agata Copani
- Department of Drug Sciences, University of Catania, Catania, Italy.,Institute of Biostructure and Bioimaging, National Research Council, Catania, Italy
| | | | - Valeria Bruno
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
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11
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Aringhieri S, Carli M, Kolachalam S, Verdesca V, Cini E, Rossi M, McCormick PJ, Corsini GU, Maggio R, Scarselli M. Molecular targets of atypical antipsychotics: From mechanism of action to clinical differences. Pharmacol Ther 2018; 192:20-41. [PMID: 29953902 DOI: 10.1016/j.pharmthera.2018.06.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The introduction of atypical antipsychotics (AAPs) since the discovery of its prototypical drug clozapine has been a revolutionary pharmacological step for treating psychotic patients as these allow a significant recovery not only in terms of hospitalization and reduction in symptoms severity, but also in terms of safety, socialization and better rehabilitation in the society. Regarding the mechanism of action, AAPs are weak D2 receptor antagonists and they act beyond D2 antagonism, involving other receptor targets which regulate dopamine and other neurotransmitters. Consequently, AAPs present a significant reduction of deleterious side effects like parkinsonism, hyperprolactinemia, apathy and anhedonia, which are all linked to the strong blockade of D2 receptors. This review revisits previous and current findings within the class of AAPs and highlights the differences in terms of receptor properties and clinical activities among them. Furthermore, we propose a continuum spectrum of "atypia" that begins with risperidone (the least atypical) to clozapine (the most atypical), while all the other AAPs fall within the extremes of this spectrum. Clozapine is still considered the gold standard in refractory schizophrenia and in psychoses present in Parkinson's disease, though it has been associated with adverse effects like agranulocytosis (0.7%) and weight gain, pushing the scientific community to find new drugs as effective as clozapine, but devoid of its side effects. To achieve this, it is therefore imperative to characterize and compare in depth the very complex molecular profile of AAPs. We also introduce relatively new concepts like biased agonism, receptor dimerization and neurogenesis to identify better the old and new hallmarks of "atypia". Finally, a detailed confrontation of clinical differences among the AAPs is presented, especially in relation to their molecular targets, and new means like therapeutic drug monitoring are also proposed to improve the effectiveness of AAPs in clinical practice.
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Affiliation(s)
- Stefano Aringhieri
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Marco Carli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Shivakumar Kolachalam
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Valeria Verdesca
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Enrico Cini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Mario Rossi
- Institute of Molecular Cell and Systems Biology, University of Glasgow, UK
| | - Peter J McCormick
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - Giovanni U Corsini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Roberto Maggio
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, Italy
| | - Marco Scarselli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy.
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12
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Jin LE, Wang M, Yang ST, Yang Y, Galvin VC, Lightbourne TC, Ottenheimer D, Zhong Q, Stein J, Raja A, Paspalas CD, Arnsten AFT. mGluR2/3 mechanisms in primate dorsolateral prefrontal cortex: evidence for both presynaptic and postsynaptic actions. Mol Psychiatry 2017; 22:1615-1625. [PMID: 27502475 PMCID: PMC5298940 DOI: 10.1038/mp.2016.129] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/04/2016] [Accepted: 06/15/2016] [Indexed: 01/12/2023]
Abstract
Cognitive deficits in psychiatric and age-related disorders generally involve dysfunction of the dorsolateral prefrontal cortex (dlPFC), but there are few treatments for these debilitating symptoms. Group II metabotropic glutamate receptors (mGluR2/3), which couple to Gi/Go, have been a focus of therapeutics based on rodent research, where mGluR2/3 have been shown to reduce axonal glutamate release and increase glial glutamate uptake. However, this strategy has had mixed results in patients, and understanding mGluR2/3 mechanisms in primates will help guide therapeutic interventions. The current study examined mGluR2/3 localization and actions in the primate dlPFC layer III circuits underlying working memory, where the persistent firing of 'Delay cells' is mediated by N-methyl-d-aspartate receptors and weakened by cAMP-PKA-potassium channel signaling in dendritic spines. Immunoelectron microscopy identified postsynaptic mGluR2/3 in the spines, in addition to the traditional presynaptic and astrocytic locations. In vivo iontophoretic application of the mGluR2/3 agonists (2R, 4R)-APDC or LY379268 onto dlPFC Delay cells produced an inverted-U effect on working memory representation, with enhanced neuronal firing following low doses of mGluR2/3 agonists. The enhancing effects were reversed by an mGluR2/3 antagonist or by activating cAMP signaling, consistent with mGluR2/3 inhibiting postsynaptic cAMP signaling in spines. Systemic administration of these agonists to monkeys performing a working memory task also produced an inverted-U dose-response, where low doses improved performance but higher doses, similar to clinical trials, had mixed effects. Our data suggest that low doses of mGluR2/3 stimulation may have therapeutic effects through unexpected postsynaptic actions in dlPFC, strengthening synaptic connections and improving cognitive function.
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Affiliation(s)
- L E Jin
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - M Wang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - S-T Yang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Y Yang
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - V C Galvin
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - T C Lightbourne
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - D Ottenheimer
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Q Zhong
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - J Stein
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - A Raja
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - C D Paspalas
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA,Department of Neuroscience, Yale School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, USA. E-mail: or
| | - A F T Arnsten
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, CT, USA,Department of Neuroscience, Yale School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, USA. E-mail: or
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13
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Di Menna L, Joffe ME, Iacovelli L, Orlando R, Lindsley CW, Mairesse J, Gressèns P, Cannella M, Caraci F, Copani A, Bruno V, Battaglia G, Conn PJ, Nicoletti F. Functional partnership between mGlu3 and mGlu5 metabotropic glutamate receptors in the central nervous system. Neuropharmacology 2017; 128:301-313. [PMID: 29079293 DOI: 10.1016/j.neuropharm.2017.10.026] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 10/09/2017] [Accepted: 10/21/2017] [Indexed: 12/19/2022]
Abstract
mGlu5 receptors are involved in mechanisms of activity-dependent synaptic plasticity, and are targeted by drugs developed for the treatment of CNS disorders. We report that mGlu3 receptors, which are traditionally linked to the control of neurotransmitter release, support mGlu5 receptor signaling in neurons and largely contribute to the robust mGlu5 receptor-mediated polyphosphoinositide hydrolysis in the early postnatal life. In cortical pyramidal neurons, mGlu3 receptor activation potentiated mGlu5 receptor-mediated somatic Ca2+ mobilization, and mGlu3 receptor-mediated long-term depression in the prefrontal cortex required the endogenous activation of mGlu5 receptors. The interaction between mGlu3 and mGlu5 receptors was also relevant to mechanisms of neuronal toxicity, with mGlu3 receptors shaping the influence of mGlu5 receptors on excitotoxic neuronal death. These findings shed new light into the complex role played by mGlu receptors in physiology and pathology, and suggest reconsideration of some of the current dogmas in the mGlu receptor field.
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Affiliation(s)
| | - Max E Joffe
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232-0697, USA
| | - Luisa Iacovelli
- Department of Physiology and Pharmacology, University Sapienza of Roma, 00185 Roma, Italy
| | - Rosamaria Orlando
- Department of Physiology and Pharmacology, University Sapienza of Roma, 00185 Roma, Italy
| | - Craig W Lindsley
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232-0697, USA
| | - Jèrome Mairesse
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, 1141 Paris, France
| | - Pierre Gressèns
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, 1141 Paris, France; Centre for the Developing Brain, Department of Perinatal Health and Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | | | - Filippo Caraci
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; I.R.C.C.S. Oasi Maria SS, 94018 Troina, Italy
| | - Agata Copani
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; Institute of Biostructure and Bioimaging, National Research Council, 95126 Catania, Italy
| | - Valeria Bruno
- I.R.C.C.S. Neuromed, 86077 Pozzilli, Italy; Department of Physiology and Pharmacology, University Sapienza of Roma, 00185 Roma, Italy
| | | | - P Jeffrey Conn
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232-0697, USA
| | - Ferdinando Nicoletti
- I.R.C.C.S. Neuromed, 86077 Pozzilli, Italy; Department of Physiology and Pharmacology, University Sapienza of Roma, 00185 Roma, Italy.
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14
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Panaccione I, Iacovelli L, di Nuzzo L, Nardecchia F, Mauro G, Janiri D, De Blasi A, Sani G, Nicoletti F, Orlando R. Paradoxical sleep deprivation in rats causes a selective reduction in the expression of type-2 metabotropic glutamate receptors in the hippocampus. Pharmacol Res 2017; 117:46-53. [DOI: 10.1016/j.phrs.2016.11.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 11/10/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022]
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15
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García-Bea A, Walker MA, Hyde TM, Kleinman JE, Harrison PJ, Lane TA. Metabotropic glutamate receptor 3 (mGlu3; mGluR3; GRM3) in schizophrenia: Antibody characterisation and a semi-quantitative western blot study. Schizophr Res 2016; 177:18-27. [PMID: 27130562 PMCID: PMC5145804 DOI: 10.1016/j.schres.2016.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND Metabotropic glutamate receptor 3 (mGlu3, mGluR3), encoded by GRM3, is a risk gene for schizophrenia and a therapeutic target. It is unclear whether expression of the receptor is altered in the disorder or related to GRM3 risk genotype. Antibodies used to date to assess mGlu3 in schizophrenia have not been well validated. OBJECTIVE To characterise six commercially available anti-mGlu3 antibodies for use in human brain, and then conduct a semi-quantitative study of mGlu3 immunoreactivity in schizophrenia. METHODS Antibodies tested using Grm3-/- and Grm2-/-/3-/- mice and transfected HEK293T/17 cells. Western blotting on membrane protein isolated from superior temporal cortex of 70 patients with schizophrenia and 87 healthy comparison subjects, genotyped for GRM3 SNP rs10234440. RESULTS One (out of six) anti-mGlu3 antibodies was fully validated, a C-terminal antibody which detected monomeric (~100kDa) and dimeric (~200kDa) mGlu3. A second, N-terminal, antibody detected the 200kDa band but also produced non-specific bands. Using the C-terminal antibody for western blotting in human brain, mGlu3 immunoreactivity was found to decline with age, and was affected by pH and post mortem interval. There were no differences in monomeric or dimeric mGlu3 immunoreactivity in schizophrenia or in relation to GRM3 genotype. The antibody was not suitable for immunohistochemistry. INTERPRETATION These data highlight the value of knockout mouse tissue for antibody validation, and the need for careful antibody characterisation. The schizophrenia data show that involvement of GRM3 in the disorder and its genetic risk architecture is not reflected in total membrane mGlu3 immunoreactivity in superior temporal cortex.
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Affiliation(s)
| | - Mary A Walker
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Thomas M Hyde
- Lieber Institute for Brain Development, Baltimore, USA; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, USA; Department of Psychiatry & Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, USA
| | | | - Paul J Harrison
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, United Kingdom
| | - Tracy A Lane
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom.
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16
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Muguruza C, Meana JJ, Callado LF. Group II Metabotropic Glutamate Receptors as Targets for Novel Antipsychotic Drugs. Front Pharmacol 2016; 7:130. [PMID: 27242534 PMCID: PMC4873505 DOI: 10.3389/fphar.2016.00130] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/05/2016] [Indexed: 11/13/2022] Open
Abstract
Schizophrenia is a chronic psychiatric disorder which substantially impairs patients' quality of life. Despite the extensive research in this field, the pathophysiology and etiology of schizophrenia remain unknown. Different neurotransmitter systems and functional networks have been found to be affected in the brain of patients with schizophrenia. In this context, postmortem brain studies as well as genetic assays have suggested alterations in Group II metabotropic glutamate receptors (mGluRs) in schizophrenia. Despite many years of drug research, several needs in the treatment of schizophrenia have not been addressed sufficiently. In fact, only 5-10% of patients with schizophrenia successfully achieve a full recovery after treatment. In recent years mGluRs have turned up as novel targets for the design of new antipsychotic medications for schizophrenia. Concretely, Group II mGluRs are of particular interest due to their regulatory role in neurotransmission modulating glutamatergic activity in brain synapses. Preclinical studies have demonstrated that orthosteric Group II mGluR agonists exhibit antipsychotic-like properties in animal models of schizophrenia. However, when these compounds have been tested in human clinical studies with schizophrenic patients results have been inconclusive. Nevertheless, it has been recently suggested that this apparent lack of efficacy in schizophrenic patients may be related to previous exposure to atypical antipsychotics. Moreover, the role of the functional heterocomplex formed by 5-HT2A and mGlu2 receptors in the clinical response to Group II mGluR agonists is currently under study.
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Affiliation(s)
- Carolina Muguruza
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - J. Javier Meana
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - Luis F. Callado
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
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Bruno V, Caraci F, Copani A, Matrisciano F, Nicoletti F, Battaglia G. The impact of metabotropic glutamate receptors into active neurodegenerative processes: A "dark side" in the development of new symptomatic treatments for neurologic and psychiatric disorders. Neuropharmacology 2016; 115:180-192. [PMID: 27140693 DOI: 10.1016/j.neuropharm.2016.04.044] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/22/2016] [Accepted: 04/28/2016] [Indexed: 12/17/2022]
Abstract
Metabotropic glutamate (mGlu) receptor ligands are under clinical development for the treatment of CNS disorders with high social and economic burden, such as schizophrenia, major depressive disorder (MDD), and Parkinson's disease (PD), and are promising drug candidates for the treatment of Alzheimer's disease (AD). So far, clinical studies have shown symptomatic effects of mGlu receptor ligands, but it is unknown whether these drugs act as disease modifiers or, at the opposite end, they accelerate disease progression by enhancing neurodegeneration. This is a fundamental issue in the treatment of PD and AD, and is also an emerging theme in the treatment of schizophrenia and MDD, in which neurodegeneration is also present and contribute to disease progression. Moving from in vitro data and preclinical studies, we discuss the potential impact of drugs targeting mGlu2, mGlu3, mGlu4 and mGlu5 receptor ligands on active neurodegeneration associated with AD, PD, schizophrenia, and MDD. We wish to highlight that our final comments on the best drug candidates are not influenced by commercial interests or by previous or ongoing collaborations with drug companies. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Valeria Bruno
- Department of Physiology and Pharmacology, University Sapienza, 00185 Rome, Italy; I.R.C.C.S. Neuromed, 86077 Pozzilli, Italy.
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; I.R.C.C.S. Associazione Oasi Maria S.S., Institute for Research on Mental Retardation and Brain Aging, 94018 Troina, Italy
| | - Agata Copani
- Department of Drug Sciences, University of Catania, 95125 Catania, Italy; National Research Council, Institute of Biostructure and Bioimaging (IBB-CNR), 95126 Catania, Italy
| | - Francesco Matrisciano
- Department of Psychiatry and Behavioral Sciences, Northwestern Feinberg School of Medicine, Chicago, USA
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, University Sapienza, 00185 Rome, Italy; I.R.C.C.S. Neuromed, 86077 Pozzilli, Italy
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18
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Engel M, Snikeris P, Matosin N, Newell KA, Huang XF, Frank E. mGluR2/3 agonist LY379268 rescues NMDA and GABAA receptor level deficits induced in a two-hit mouse model of schizophrenia. Psychopharmacology (Berl) 2016; 233:1349-59. [PMID: 26861891 DOI: 10.1007/s00213-016-4230-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 01/29/2016] [Indexed: 10/22/2022]
Abstract
RATIONALE An imbalance of excitatory and inhibitory neurotransmission underlies the glutamate hypothesis of schizophrenia. Agonists of group II metabotropic glutamate receptors, mGluR2/3, have been proposed as novel therapeutic agents to correct this imbalance. However, the influence of mGluR2/3 activity on excitatory and inhibitory neurotransmitter receptors has not been explored. OBJECTIVES We aimed to investigate the ability of a novel mGluR2/3 agonist, LY379268, to modulate the availability of the excitatory N-methyl-D-aspartate receptor (NMDA-R) and the inhibitory gamma-aminobutyrate-A receptor (GABAA-R), in a two-hit mouse model of schizophrenia. METHODS Wild type (WT) and heterozygous neuregulin 1 transmembrane domain mutant mice (NRG1 HET) were treated daily with phencyclidine (10 mg/kg ip) or saline for 14 days. After a 14-day washout, an acute dose of the mGluR2/3 agonist LY379268 (3 mg/kg), olanzapine (antipsychotic drug comparison, 1.5 mg/kg), or saline was administered. NMDA-R and GABAA-R binding densities were examined by receptor autoradiography in several schizophrenia-relevant brain regions. RESULTS In both WT and NRG1 HET mice, phencyclidine treatment significantly reduced NMDA-R and GABAA-R binding density in the prefrontal cortex, hippocampus, and nucleus accumbens. Acute treatment with LY379268 restored NMDA-R and GABAA-R levels in the two-hit mouse model comparable to olanzapine. CONCLUSIONS We demonstrate that the mGluR2/3 agonist LY379268 restores excitatory and inhibitory deficits with similar efficiency as olanzapine in our two-hit schizophrenia mouse model. This study significantly contributes to our understanding of the mechanisms underlying the therapeutic effects of LY379268 and supports the use of agents aimed at mGluR2/3.
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Affiliation(s)
- Martin Engel
- Schizophrenia Research Institute, Sydney, Australia. .,Faculty of Science Medicine and Health, University of Wollongong, Wollongong, Australia. .,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia. .,School of Biological Sciences, University of Wollongong, Wollongong, Australia.
| | - Peta Snikeris
- Schizophrenia Research Institute, Sydney, Australia.,Faculty of Science Medicine and Health, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Natalie Matosin
- Schizophrenia Research Institute, Sydney, Australia.,Faculty of Science Medicine and Health, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Kelly Anne Newell
- Schizophrenia Research Institute, Sydney, Australia.,Faculty of Science Medicine and Health, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Xu-Feng Huang
- Schizophrenia Research Institute, Sydney, Australia.,Faculty of Science Medicine and Health, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Elisabeth Frank
- Schizophrenia Research Institute, Sydney, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
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McOmish CE, Pavey G, Gibbons A, Hopper S, Udawela M, Scarr E, Dean B. Lower [3H]LY341495 binding to mGlu2/3 receptors in the anterior cingulate of subjects with major depressive disorder but not bipolar disorder or schizophrenia. J Affect Disord 2016; 190:241-248. [PMID: 26521087 DOI: 10.1016/j.jad.2015.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/10/2015] [Accepted: 10/02/2015] [Indexed: 01/20/2023]
Abstract
INTRODUCTION The glutamatergic system has recently been implicated in the pathogenesis and treatment of major depressive disorders(MDD) and mGlu2/3 receptors play an important role in regulating glutamatergic tone. We therefore measured cortical levels of mGlu2/3 to determine if they were changed in MDD. METHODS Binding parameters for [(3)H]LY341495 (mGlu2/3 antagonist) were determined to allow optimized in situ binding with autoradiography to be completed using a number of CNS regions. Subsequently, density of [(3)H]LY341495 binding was measured in BA24(anterior cingulate cortex), BA17(visual cortex) and BA46(dorsolateral prefrontal cortex) from subjects with MDD, Bipolar Disorder(BPD), Schizophrenia(SCZ), and controls, as well as rats treated with imipramine (20mg/kg), fluoxetine (10mg/kg), or vehicle. RESULTS mGlu2/3 are widely expressed throughout the brain with high levels observed in cortex. [(3)H]LY341495 binding was significantly lower in BA24 from subjects with MDD (mean ± SEM=141.3 ± 14.65 fmol/ETE) relative to controls (184.9 ± 7.76 fmol/ETE; Cohen's d=1.005, p<0.05). There were no other differences with diagnoses, and chronic antidepressant treatment in rats had minimal effect on binding. LIMITATIONS Using this approach we are unable to determine whether the change represents fluctuations in mGlu2, mGlu3, or both. Moreover, using postmortem tissue we are unable to dissociate the irrevocable confound of suicidality upon binding levels. CONCLUSION We have demonstrated lower [(3)H]LY341495 binding levels in MDD in BA24-a brain region implicated in depression. Moreover we show that the lower levels are unlikely to be the result of antidepressant treatment. These data suggest that levels of either mGlu2 and/or mGlu3 are affected in the aetiology of MDD.
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Affiliation(s)
- Caitlin E McOmish
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia; Department of Psychiatry, Columbia University, New York, NY, USA.
| | - Geoff Pavey
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia
| | - Andrew Gibbons
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia
| | - Shaun Hopper
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia
| | - Madhara Udawela
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia
| | - Elizabeth Scarr
- Department of Psychiatry, University of Melbourne, Victoria, Australia
| | - Brian Dean
- The Florey Institute for Neuroscience and Mental Health and the University of Melbourne, Victoria, Australia; Department of Psychiatry, University of Melbourne, Victoria, Australia
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Kinoshita A, Takizawa R, Koike S, Satomura Y, Kawasaki S, Kawakubo Y, Marumo K, Tochigi M, Sasaki T, Nishimura Y, Kasai K. Effect of metabotropic glutamate receptor-3 variants on prefrontal brain activity in schizophrenia: An imaging genetics study using multi-channel near-infrared spectroscopy. Prog Neuropsychopharmacol Biol Psychiatry 2015; 62:14-21. [PMID: 25914064 DOI: 10.1016/j.pnpbp.2015.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 04/16/2015] [Accepted: 04/16/2015] [Indexed: 12/31/2022]
Abstract
BACKGROUND The glutamatergic system is essential for learning and memory through its crucial role in neural development and synaptic plasticity. Genes associated with the glutamatergic system, including metabotropic glutamate receptor (mGluR or GRM) genes, have been implicated in the pathophysiology of schizophrenia. Few studies, however, have investigated a relationship between polymorphism of glutamate-related genes and cortical function in vivo in patients with schizophrenia. We thus explored an association between genetic variations in GRM3 and brain activation driven by a cognitive task in the prefrontal cortex in patients with schizophrenia. MATERIALS AND METHODS Thirty-one outpatients with schizophrenia and 48 healthy controls participated in this study. We measured four candidate single nucleotide polymorphisms (rs274622, rs2299225, rs1468412, and rs6465084) of GRM3, and activity in the prefrontal and temporal cortices during a category version of a verbal fluency task, using a 52-channel near-infrared spectroscopy instrument. RESULTS AND DISCUSSION The rs274622 C carriers with schizophrenia were associated with significantly smaller prefrontal activation than patients with TT genotype. This between-genotype difference tended to be confined to the patient group. GRM3 polymorphisms are associated with prefrontal activation during cognitive task in schizophrenia.
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Affiliation(s)
- Akihide Kinoshita
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Ryu Takizawa
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London SE5 8AF, UK
| | - Shinsuke Koike
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; Office for Mental Health Support, Division for Counseling and Support, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yoshihiro Satomura
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Shingo Kawasaki
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; Application Development Office, Hitachi Medical Corporation, Kashiwa City, Chiba 277-0804, Japan
| | - Yuki Kawakubo
- Department of Child Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Kohei Marumo
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Mamoru Tochigi
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Psychiatry, Teikyo University School of Medicine, Itabashi-ku, Tokyo 173-8605, Japan
| | - Tsukasa Sasaki
- Department of Physical and Health Education, Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yukika Nishimura
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Kiyoto Kasai
- Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan.
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In the grey zone between epilepsy and schizophrenia: alterations in group II metabotropic glutamate receptors. Acta Neurol Belg 2015; 115:221-32. [PMID: 25539775 DOI: 10.1007/s13760-014-0407-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/05/2014] [Indexed: 01/09/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the brain. The glutamate system plays an important role in the formation of synapses during brain development and synaptic plasticity. Dysfunctions in glutamate regulation may lead to hyperexcitatory neuronal networks and neurotoxicity. Glutamate excess is possibly of great importance in the pathophysiology of several neurological and psychiatric disorders such as epilepsy and schizophrenia. Interestingly, cross talk between these disorders has been well documented: psychiatric comorbidities are frequent in epilepsy and temporal lobe epilepsy is one of the highest risk factors for developing psychosis. Therefore, dysfunctions in glutamatergic neurotransmission might constitute a common pathological mechanism. A major negative feedback system is regulated by the presynaptic group II metabotropic glutamate (mGlu) receptors including mGlu2/3 receptors. These receptors are predominantly localised extrasynaptically in basal ganglia and limbic structures. Hence, mGlu2/3 receptors are an interesting target for the treatment of disorders like epilepsy and schizophrenia. A dysfunction in the glutamate system may be associated with alterations in mGlu2/3 receptor expression. In this review, we describe the localization of mGlu2/3 receptors in the healthy brain of mice, rats and humans. Secondly, changes in mGlu2/3 receptor density of the brain regions affected in epilepsy and schizophrenia are summarised. Increased mGlu2/3 receptor density might represent a compensatory mechanism of the brain to regulate elevated glutamate levels, while reduced mGlu2/3 receptor density in some brain regions may further contribute to the aberrant hyperexcitability. Further research considering the mGlu2/3 receptor can contribute significantly to the understanding of the etiological and therapeutic role of group II mGlu receptor in epilepsy, epilepsy with psychosis and schizophrenia.
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22
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Matosin N, Fernandez-Enright F, Fung SJ, Lum JS, Engel M, Andrews JL, Huang XF, Weickert CS, Newell KA. Alterations of mGluR5 and its endogenous regulators Norbin, Tamalin and Preso1 in schizophrenia: towards a model of mGluR5 dysregulation. Acta Neuropathol 2015; 130:119-29. [PMID: 25778620 DOI: 10.1007/s00401-015-1411-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 12/30/2022]
Abstract
Knockout of genes encoding metabotropic glutamate receptor 5 (mGluR5) or its endogenous regulators, such as Norbin, induce a schizophrenia-like phenotype in rodents, suggesting dysregulation of mGluR5 in schizophrenia. Human genetic and pharmacological animal studies support this hypothesis, but no studies have explored mGluR5 dysfunction at the molecular level in the postmortem schizophrenia brain. We assessed mGluR5 mRNA and protein levels in the dorsolateral prefrontal cortex (DLPFC) using a large cohort of schizophrenia and control subjects (n = 37/group), and additionally measured protein levels of recently discovered mGluR5 endogenous regulators, Norbin (neurochondrin), Tamalin (GRASP-1), and Preso1 (FRMPD4), which regulate mGluR5 localization, internalization and signaling. While mGluR5 mRNA expression was unchanged, mGluR5 protein levels were significantly higher in schizophrenia subjects compared to controls (total: +22%; dimer: +54%; p < 0.001). Conversely, mGluR5 regulatory proteins were expressed at lower levels in schizophrenia subjects compared to controls (Norbin -37%, p < 0.001; Tamalin -30%, p = 0.084; Preso1 -29%, p = 0.001). mGluR5 protein was significantly associated with mGluR5 mRNA and mGluR5 endogenous regulators in control subjects, but these associations were lost in schizophrenia subjects. Lastly, there were no associations between protein measures and lifetime antipsychotic history in schizophrenia subjects. To confirm no antipsychotic influence, all proteins were measured in the prefrontal cortex of rats exposed to haloperidol or olanzapine; there were no effects of antipsychotic drug treatment on mGluR5, Norbin, Tamalin or Preso1. The results from our study provide compelling evidence that mGluR5 regulation is altered in schizophrenia, likely contributing to the altered glutamatergic signaling that is associated with the disorder.
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Affiliation(s)
- Natalie Matosin
- Faculty of Science, Medicine and Health, University of Wollongong, Northfields Ave, Wollongong, NSW, 2522, Australia
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23
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Pritchett D, Jagannath A, Brown LA, Tam SKE, Hasan S, Gatti S, Harrison PJ, Bannerman DM, Foster RG, Peirson SN. Deletion of Metabotropic Glutamate Receptors 2 and 3 (mGlu2 & mGlu3) in Mice Disrupts Sleep and Wheel-Running Activity, and Increases the Sensitivity of the Circadian System to Light. PLoS One 2015; 10:e0125523. [PMID: 25950516 PMCID: PMC4423919 DOI: 10.1371/journal.pone.0125523] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/14/2015] [Indexed: 12/22/2022] Open
Abstract
Sleep and/or circadian rhythm disruption (SCRD) is seen in up to 80% of schizophrenia patients. The co-morbidity of schizophrenia and SCRD may in part stem from dysfunction in common brain mechanisms, which include the glutamate system, and in particular, the group II metabotropic glutamate receptors mGlu2 and mGlu3 (encoded by the genes Grm2 and Grm3). These receptors are relevant to the pathophysiology and potential treatment of schizophrenia, and have also been implicated in sleep and circadian function. In the present study, we characterised the sleep and circadian rhythms of Grm2/3 double knockout (Grm2/3-/-) mice, to provide further evidence for the involvement of group II metabotropic glutamate receptors in the regulation of sleep and circadian rhythms. We report several novel findings. Firstly, Grm2/3-/- mice demonstrated a decrease in immobility-determined sleep time and an increase in immobility-determined sleep fragmentation. Secondly, Grm2/3-/- mice showed heightened sensitivity to the circadian effects of light, manifested as increased period lengthening in constant light, and greater phase delays in response to nocturnal light pulses. Greater light-induced phase delays were also exhibited by wildtype C57Bl/6J mice following administration of the mGlu2/3 negative allosteric modulator RO4432717. These results confirm the involvement of group II metabotropic glutamate receptors in photic entrainment and sleep regulation pathways. Finally, the diurnal wheel-running rhythms of Grm2/3-/- mice were perturbed under a standard light/dark cycle, but their diurnal rest-activity rhythms were unaltered in cages lacking running wheels, as determined with passive infrared motion detectors. Hence, when assessing the diurnal rest-activity rhythms of mice, the choice of assay can have a major bearing on the results obtained.
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Affiliation(s)
- David Pritchett
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
| | - Aarti Jagannath
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
- F.Hoffman-La Roche, Neuroscience, Ophthalmology & Rare Diseases (NORD), Pharma Research & Early Development (pRED) Innovation Centre, Basel, Switzerland
| | - Laurence A. Brown
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
| | - Shu K. E. Tam
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
| | - Sibah Hasan
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
| | - Silvia Gatti
- F.Hoffman-La Roche, Neuroscience, Ophthalmology & Rare Diseases (NORD), Pharma Research & Early Development (pRED) Innovation Centre, Basel, Switzerland
| | - Paul J. Harrison
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, OX3 7JX, United Kingdom
| | - David M. Bannerman
- Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, OX1 3UD, United Kingdom
| | - Russell G. Foster
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
- * E-mail: (RGF); (SNP)
| | - Stuart N. Peirson
- Nuffield Department of Clinical Neurosciences (Nuffield Laboratory of Ophthalmology), University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, United Kingdom
- * E-mail: (RGF); (SNP)
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24
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Zhang H, Cilz NI, Yang C, Hu B, Dong H, Lei S. Depression of neuronal excitability and epileptic activities by group II metabotropic glutamate receptors in the medial entorhinal cortex. Hippocampus 2015; 25:1299-313. [DOI: 10.1002/hipo.22437] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Haopeng Zhang
- Department of Basic Sciences; School of Medicine and Health Sciences, University of North Dakota; Grand Forks North Dakota
- Department of Anesthesiology; Xijing Hospital, Fourth Military Medical University; Xi'an Shaanxi Province China
| | - Nicholas I. Cilz
- Department of Basic Sciences; School of Medicine and Health Sciences, University of North Dakota; Grand Forks North Dakota
| | - Chuanxiu Yang
- Department of Basic Sciences; School of Medicine and Health Sciences, University of North Dakota; Grand Forks North Dakota
| | - Binqi Hu
- Department of Basic Sciences; School of Medicine and Health Sciences, University of North Dakota; Grand Forks North Dakota
| | - Hailong Dong
- Department of Anesthesiology; Xijing Hospital, Fourth Military Medical University; Xi'an Shaanxi Province China
| | - Saobo Lei
- Department of Basic Sciences; School of Medicine and Health Sciences, University of North Dakota; Grand Forks North Dakota
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25
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Fatemi SH, Folsom TD. Existence of monomer and dimer forms of mGluR5, under reducing conditions in studies of postmortem brain in various psychiatric disorders. Schizophr Res 2014; 158:270-1. [PMID: 25043265 DOI: 10.1016/j.schres.2014.06.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/20/2014] [Accepted: 06/23/2014] [Indexed: 11/30/2022]
Affiliation(s)
- S Hossein Fatemi
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, 420 Delaware St. SE, MMC 392, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota Medical School, 321 Church St. SE, Minneapolis, MN 55455, USA.
| | - Timothy D Folsom
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, 420 Delaware St. SE, MMC 392, Minneapolis, MN 55455, USA.
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26
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Orlando R, Borro M, Motolese M, Molinaro G, Scaccianoce S, Caruso A, di Nuzzo L, Caraci F, Matrisciano F, Pittaluga A, Mairesse J, Simmaco M, Nisticò R, Monn JA, Nicoletti F. Levels of the Rab GDP dissociation inhibitor (GDI) are altered in the prenatal restrain stress mouse model of schizophrenia and are differentially regulated by the mGlu2/3 receptor agonists, LY379268 and LY354740. Neuropharmacology 2014; 86:133-44. [PMID: 25063582 DOI: 10.1016/j.neuropharm.2014.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 11/24/2022]
Abstract
LY379268 and LY354740, two agonists of mGlu2/3 metabotropic glutamate receptors, display different potencies in mouse models of schizophrenia. This differential effect of the two drugs remains unexplained. We performed a proteomic analysis in cultured cortical neurons challenged with either LY379268 or LY354740. Among the few proteins that were differentially influenced by the two drugs, Rab GDP dissociation inhibitor-β (Rab GDIβ) was down-regulated by LY379268 and showed a trend to an up-regulation in response to LY354740. In cultured hippocampal neurons, LY379268 selectively down-regulated the α isoform of Rab GDI. Rab GDI inhibits the activity of the synaptic vesicle-associated protein, Rab3A, and is reduced in the brain of schizophrenic patients. We examined the expression of Rab GDI in mice exposed to prenatal stress ("PRS mice"), which have been described as a putative model of schizophrenia. Rab GDIα protein levels were increased in the hippocampus of PRS mice at postnatal days (PND)1 and 21, but not at PND60. At PND21, PRS mice also showed a reduced depolarization-evoked [(3)H]d-aspartate release in hippocampal synaptosomes. The increase in Rab GDIα levels in the hippocampus of PRS mice was reversed by a 7-days treatment with LY379268 (1 or 10 mg/kg, i.p.), but not by treatment with equal doses of LY354740. These data strengthen the validity of PRS mice as a model of schizophrenia, and show for the first time a pharmacodynamic difference between LY379268 and LY354740 which might be taken into account in an attempt to explain the differential effect of the two drugs across mouse models.
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Affiliation(s)
- Rosamaria Orlando
- IRCCS Associazione Oasi Maria S.S., Institute for Research on Mental Retardation and Brain Aging, Troina, Enna, Italy
| | - Marina Borro
- NESMOS Department, Advanced Molecular Diagnostic Unit, Sapienza University, Sant'Andrea Hospital, Rome, Italy
| | | | | | - Sergio Scaccianoce
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - Alessandra Caruso
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - Luigi di Nuzzo
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - Filippo Caraci
- IRCCS Associazione Oasi Maria S.S., Institute for Research on Mental Retardation and Brain Aging, Troina, Enna, Italy; Department of Educational Sciences, University of Catania, Catania, Italy
| | | | - Anna Pittaluga
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genoa, Genoa, Italy
| | - Jerome Mairesse
- Neural Plasticity Team, Université Lille 1, International Associated Laboratory (LIA), France
| | - Maurizio Simmaco
- NESMOS Department, Advanced Molecular Diagnostic Unit, Sapienza University, Sant'Andrea Hospital, Rome, Italy
| | - Robert Nisticò
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - James A Monn
- Discovery Chemistry Research and Technologies, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Ferdinando Nicoletti
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy.
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Pomierny-Chamioło L, Rup K, Pomierny B, Niedzielska E, Kalivas PW, Filip M. Metabotropic glutamatergic receptors and their ligands in drug addiction. Pharmacol Ther 2014; 142:281-305. [DOI: 10.1016/j.pharmthera.2013.12.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/02/2013] [Indexed: 02/07/2023]
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Iasevoli F, Tomasetti C, Buonaguro EF, de Bartolomeis A. The glutamatergic aspects of schizophrenia molecular pathophysiology: role of the postsynaptic density, and implications for treatment. Curr Neuropharmacol 2014; 12:219-38. [PMID: 24851087 PMCID: PMC4023453 DOI: 10.2174/1570159x12666140324183406] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/14/2014] [Accepted: 03/14/2014] [Indexed: 01/23/2023] Open
Abstract
Schizophrenia is one of the most debilitating psychiatric diseases with a lifetime prevalence of approximately
1%. Although the specific molecular underpinnings of schizophrenia are still unknown, evidence has long linked its
pathophysiology to postsynaptic abnormalities.
The postsynaptic density (PSD) is among the molecular structures suggested to be potentially involved in schizophrenia.
More specifically, the PSD is an electron-dense thickening of glutamatergic synapses, including ionotropic and
metabotropic glutamate receptors, cytoskeletal and scaffolding proteins, and adhesion and signaling molecules. Being
implicated in the postsynaptic signaling of multiple neurotransmitter systems, mostly dopamine and glutamate, the PSD
constitutes an ideal candidate for studying dopamine-glutamate disturbances in schizophrenia. Recent evidence suggests
that some PSD proteins, such as PSD-95, Shank, and Homer are implicated in severe behavioral disorders, including
schizophrenia. These findings, further corroborated by genetic and animal studies of schizophrenia, offer new insights for
the development of pharmacological strategies able to overcome the limitations in terms of efficacy and side effects of
current schizophrenia treatment. Indeed, PSD proteins are now being considered as potential molecular targets against this
devastating illness.
The current paper reviews the most recent hypotheses on the molecular mechanisms underlying schizophrenia
pathophysiology. First, we review glutamatergic dysfunctions in schizophrenia and we provide an update on postsynaptic
molecules involvement in schizophrenia pathophysiology by addressing both human and animal studies. Finally, the
possibility that PSD proteins may represent potential targets for new molecular interventions in psychosis will be
discussed.
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Affiliation(s)
- Felice Iasevoli
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Carmine Tomasetti
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Elisabetta F Buonaguro
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Andrea de Bartolomeis
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
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29
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Rubio MD, Drummond JB, Meador-Woodruff JH. Glutamate receptor abnormalities in schizophrenia: implications for innovative treatments. Biomol Ther (Seoul) 2014; 20:1-18. [PMID: 24116269 PMCID: PMC3792192 DOI: 10.4062/biomolther.2012.20.1.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 11/25/2011] [Indexed: 01/18/2023] Open
Abstract
Schizophrenia is a devastating psychiatric illness that afflicts 1% of the population worldwide, resulting in substantial impact to patients, their families, and health care delivery systems. For many years, schizophrenia has been felt to be associated with dysregulated dopaminergic neurotransmission as a key feature of the pathophysiology of the illness. Although numerous studies point to dopaminergic abnormalities in schizophrenia, dopamine dysfunction cannot completely account for all of the symptoms seen in schizophrenia, and dopamine-based treatments are often inadequate and can be associated with serious side effects. More recently, converging lines of evidence have suggested that there are abnormalities of glutamate transmission in schizophrenia. Glutamatergic neurotransmission involves numerous molecules that facilitate glutamate release, receptor activation, glutamate reuptake, and other synaptic activities. Evidence for glutamatergic abnormalities in schizophrenia primarily has implicated the NMDA and AMPA subtypes of the glutamate receptor. The expression of these receptors and other molecules associated with glutamate neurotransmission has been systematically studied in the brain in schizophrenia. These studies have generally revealed region- and molecule-specific changes in glutamate receptor transcript and protein expression in this illness. Given that glutamatergic neurotransmission has been implicated in the pathophysiology of schizophrenia, recent drug development efforts have targeted the glutamate system. Much effort to date has focused on modulation of the NMDA receptor, although more recently other glutamate receptors and transporters have been the targets of drug development. These efforts have been promising thus far, and ongoing efforts to develop additional drugs that modulate glutamatergic neurotransmission are underway that may hold the potential for novel classes of more effective treatments for this serious psychiatric illness.
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Affiliation(s)
- Maria D Rubio
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294-0021, USA
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30
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Newell KA, Matosin N. Rethinking metabotropic glutamate receptor 5 pathological findings in psychiatric disorders: implications for the future of novel therapeutics. BMC Psychiatry 2014; 14:23. [PMID: 24472577 PMCID: PMC3907147 DOI: 10.1186/1471-244x-14-23] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 01/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pharmacological modulation of metabotropic glutamate receptor 5 (mGluR5) is of marked interest as a novel therapeutic mechanism to treat schizophrenia and major depression. However, the status of mGluR5 in the pathophysiology of these disorders remains unknown. DISCUSSION The majority of studies in the schizophrenia post-mortem brain indicate that total mGluR5 expression is unaltered. However, close examination of the literature suggests that these findings are superficial, and in actuality, a number of critical factors have not yet been considered; alterations may be highly dependent on brain region, neuronal population or molecular organisation in specific cellular compartments. A number of genetic knockout studies (mGluR5, Norbin, Homer1 etc.) continue to lend support to a role of mGluR5 in the pathology of schizophrenia, providing impetus to explore the regulation of mGluR5 beyond total mGluR5 protein and mRNA levels. With regards to major depression, preliminary evidence to date shows a reduction in total mGluR5 protein and mRNA levels; however, as in schizophrenia, there are no studies examining mGluR5 function or regulation in the pathological state. A comprehensive understanding of mGluR5 regulation in major depression, particularly in comparison to schizophrenia, is crucial as this has extensive implications for mGluR5 targeting novel therapeutics, especially considering that opposing modulation of mGluR5 is of therapeutic interest for these two disorders. SUMMARY Despite the complexities, examinations of post-mortem human brain provide valuable insights into the pathologies of these inherently human disorders. It is important, especially with regards to the identification of novel therapeutic drug targets, to have an in depth understanding of the pathophysiologies of these disorders. We posit that brain region- and cell type-specific alterations exist in mGluR5 in schizophrenia and depression, with evidence pointing towards altered regulation of this receptor in psychiatric pathology. We consider the implications of these alterations, as well as the distinction between schizophrenia and depression, in the context of novel mGluR5 based therapeutics.
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Affiliation(s)
- Kelly A Newell
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Natalie Matosin
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia,Schizophrenia Research Institute, Darlinghurst, NSW 2010, Australia
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King MV, Kurian N, Qin S, Papadopoulou N, Westerink BHC, Cremers TI, Epping-Jordan MP, Le Poul E, Ray DE, Fone KCF, Kendall DA, Marsden CA, Sharp TV. Lentiviral delivery of a vesicular glutamate transporter 1 (VGLUT1)-targeting short hairpin RNA vector into the mouse hippocampus impairs cognition. Neuropsychopharmacology 2014; 39:464-76. [PMID: 24037344 PMCID: PMC3870793 DOI: 10.1038/npp.2013.220] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 01/28/2023]
Abstract
Glutamate is the principle excitatory neurotransmitter in the mammalian brain, and dysregulation of glutamatergic neurotransmission is implicated in the pathophysiology of several psychiatric and neurological diseases. This study utilized novel lentiviral short hairpin RNA (shRNA) vectors to target expression of the vesicular glutamate transporter 1 (VGLUT1) following injection into the dorsal hippocampus of adult mice, as partial reductions in VGLUT1 expression should attenuate glutamatergic signaling and similar reductions have been reported in schizophrenia. The VGLUT1-targeting vector attenuated tonic glutamate release in the dorsal hippocampus without affecting GABA, and selectively impaired novel object discrimination (NOD) and retention (but not acquisition) in the Morris water maze, without influencing contextual fear-motivated learning or causing any adverse locomotor or central immune effects. This pattern of cognitive impairment is consistent with the accumulating evidence for functional differentiation along the dorsoventral axis of the hippocampus, and supports the involvement of dorsal hippocampal glutamatergic neurotransmission in both spatial and nonspatial memory. Future use of this nonpharmacological VGLUT1 knockdown mouse model could improve our understanding of glutamatergic neurobiology and aid assessment of novel therapies for cognitive deficits such as those seen in schizophrenia.
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Affiliation(s)
- Madeleine V King
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Nisha Kurian
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Si Qin
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | - Nektaria Papadopoulou
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Ben HC Westerink
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | - Thomas I Cremers
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | | | | | - David E Ray
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Kevin CF Fone
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - David A Kendall
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Charles A Marsden
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Tyson V Sharp
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
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Morrow JA, Gilfillan R, Neale SA. Glutamatergic Approaches for the Treatment of Schizophrenia. DRUG DISCOVERY FOR PSYCHIATRIC DISORDERS 2012. [DOI: 10.1039/9781849734943-00056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and plays a key role in most aspects of normal brain function including cognition, learning and memory. Dysfunction of glutamatergic neurotransmission has been implicated in a number of neurological and psychiatric disorders with a growing body of evidence suggesting that hypofunction of glutamatergic neurotransmission via the N-methyl-d-aspartate (NMDA) receptor plays an important role in the pathophysiology of schizophrenia. It thus follows that potentiation of NMDA receptor function via pharmacological manipulation may provide therapeutic utility for the treatment of schizophrenia and a number of different approaches are currently being pursued by the pharmaceutical industry with this aim in mind. These include strategies that target the glycine/d-serine site of the NMDA receptor (glycine transporter GlyT1, d-serine transporter ASC-1 and d-amino acid oxidase (DAAO) inhibitors) together with those aimed at enhancing glutamatergic neurotransmission via modulation of AMPA receptor and metabotropic glutamate receptor function. Such efforts are now beginning to bear fruit with compounds such as the GlyT1 inhibitor RG1678 and mGlu2 agonist LY2140023 proving to have clinical meaningful effects in phase II clinical trials. While more studies are required to confirm long-term efficacy, functional outcome and safety in schizophrenic agents, these agents hold real promise for addressing unmet medical needs, in particular refractory negative and cognitive symptoms, not currently addressed by existing antipsychotic agents.
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Affiliation(s)
- John A. Morrow
- Neuroscience and Ophthalmology, Merck Research Laboratories 2015 Galloping Hill Road, Kenilworth, New Jersey 07033 USA
| | - Robert Gilfillan
- Discovery Chemistry, Merck Research Laboratories 770 Sumneytown Pike, West Point, Pennsylvania 19486 USA
| | - Stuart A. Neale
- Neurexpert Ltd Ground Floor, 2 Woodberry Grove, North Finchley, London, N12 0DR UK
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Iacovelli L, Nicoletti F, De Blasi A. Molecular mechanisms that desensitize metabotropic glutamate receptor signaling: an overview. Neuropharmacology 2012; 66:24-30. [PMID: 22659473 DOI: 10.1016/j.neuropharm.2012.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/06/2012] [Accepted: 05/08/2012] [Indexed: 01/10/2023]
Abstract
The purpose of the present article is to review our actual knowledge on the desensitization of metabotropic glutamate receptors based on the literature available so far, with the attempt to emphasize all converging data and to give a possible explanation to those evidences that still remain controversial. 1. We review our knowledge on the regulation of mGlu receptors based on the available literature 2. We report converging data and we comment on issues that still remain controversial. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Luisa Iacovelli
- Dept. of Physiology and Pharmacology "V. Erspamer", University of Rome "Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy.
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Actions of Xanthurenic acid, a putative endogenous Group II metabotropic glutamate receptor agonist, on sensory transmission in the thalamus. Neuropharmacology 2012; 66:133-42. [PMID: 22491023 DOI: 10.1016/j.neuropharm.2012.03.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 02/29/2012] [Accepted: 03/13/2012] [Indexed: 11/21/2022]
Abstract
Xanthurenic acid (XA), a molecule arising from tryptophan metabolism by transamination of 3-hydroxykynurenine, has recently been identified as an endogenous Group II (mGlu2 and mGlu3) metabotropic glutamate (mGlu) receptor ligand in vitro. Impairments in Group II mGlu receptor expression and function have been implicated in the pathophysiology of schizophrenia, as have multiple steps in the kynurenine metabolism pathway. Therefore, we examined XA in vivo to further investigate its potential as a Group II mGlu receptor ligand using a preparation that has been previously demonstrated to efficiently reveal the action of other Group II mGlu receptor ligands in vivo. Extracellular single-neurone recordings were made in the rat ventrobasal thalamus (VB) in conjunction with iontophoresis of agonists, an antagonist and a positive allosteric modulator and/or intravenous (i.v.) injection of XA. We found the XA effect on sensory inhibition, when applied iontophoretically and i.v., was similar to that of other Group II mGlu receptor agonists in reducing inhibition evoked in the VB from the thalamic reticular nucleus upon physiological sensory stimulation. Furthermore, we postulate that XA may be the first potential endogenous allosteric agonist (termed 'endocoid') for the mGlu receptors. As the Group II receptors and kynurenine metabolism pathway have both been heavily implicated in the pathophysiology of schizophrenia, XA could play a pivotal role in antipsychotic research as this potential endocoid represents both a convergence within these two biological parameters and a novel class of Group II mGlu receptor ligand. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Schwendt M, Reichel CM, See RE. Extinction-dependent alterations in corticostriatal mGluR2/3 and mGluR7 receptors following chronic methamphetamine self-administration in rats. PLoS One 2012; 7:e34299. [PMID: 22479593 PMCID: PMC3315516 DOI: 10.1371/journal.pone.0034299] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 02/25/2012] [Indexed: 01/12/2023] Open
Abstract
Methamphetamine (meth) is a highly addictive and widely abused psychostimulant. Repeated use of meth can quickly lead to dependence, and may be accompanied by a variety of persistent psychiatric symptoms and cognitive impairments. The neuroadaptations underlying motivational and cognitive deficits produced by chronic meth intake remain poorly understood. Altered glutamate neurotransmission within the prefrontal cortex (PFC) and striatum has been linked to both persistent drug-seeking and cognitive dysfunction. Therefore, the current study investigated changes in presynaptic mGluR receptors within corticostriatal circuitry after extended meth self-administration. Rats self-administered meth (or received yoked-saline) in 1 hr/day sessions for 7 days (short-access) followed by 14 days of 6 hrs/day (long-access). Rats displayed a progressive escalation of daily meth intake up to 6 mg/kg per day. After cessation of meth self-administration, rats underwent daily extinction or abstinence without extinction training for 14 days before being euthanized. Synaptosomes from the medial PFC, nucleus accumbens (NAc), and the dorsal striatum (dSTR) were isolated and labeled with membrane-impermeable biotin in order to measure surface mGluR2/3 and mGluR7 receptors. Extended access to meth self-administration followed by abstinence decreased surface and total levels of mGluR2/3 receptors in the NAc and dSTR, while in the PFC, only a loss of surface mGluR2/3 and mGluR7 receptors was detected. Daily extinction trials reversed the downregulation of mGluR2/3 receptors in the NAc and dSTR and mGluR7 in the PFC, but downregulation of surface mGluR2/3 receptors in the PFC was present regardless of post-meth experience. Thus, extinction learning can selectively restore some populations of downregulated mGluRs after prolonged exposure to meth. The present findings could have implications for our understanding of the persistence (or recovery) of meth-induced motivational and cognitive deficits.
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Affiliation(s)
- Marek Schwendt
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States of America.
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Fell MJ, McKinzie DL, Monn JA, Svensson KA. Group II metabotropic glutamate receptor agonists and positive allosteric modulators as novel treatments for schizophrenia. Neuropharmacology 2012; 62:1473-83. [DOI: 10.1016/j.neuropharm.2011.06.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 06/07/2011] [Accepted: 06/08/2011] [Indexed: 10/18/2022]
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Kawakubo Y, Suga M, Tochigi M, Yumoto M, Itoh K, Sasaki T, Kano Y, Kasai K. Effects of metabotropic glutamate receptor 3 genotype on phonetic mismatch negativity. PLoS One 2011; 6:e24929. [PMID: 22022368 PMCID: PMC3191133 DOI: 10.1371/journal.pone.0024929] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/23/2011] [Indexed: 11/18/2022] Open
Abstract
Background The genetic and molecular basis of glutamatergic dysfunction is one key to understand schizophrenia, with the identification of an intermediate phenotype being an essential step. Mismatch negativity (MMN) or its magnetic counterpart, magnetic mismatch field (MMF) is an index of preattentive change detection processes in the auditory cortex and is generated through glutamatergic neurotransmission. We have previously shown that MMN/MMF in response to phoneme change is markedly reduced in schizophrenia. Variations in metabotropic glutamate receptor (GRM3) may be associated with schizophrenia, and has been shown to affect cortical function. Here we investigated the effect of GRM3 genotypes on phonetic MMF in healthy men. Methods MMF in response to phoneme change was recorded using magnetoencephalography in 41 right-handed healthy Japanese men. Based on previous genetic association studies in schizophrenia, 4 candidate SNPs (rs6465084, rs2299225, rs1468412, rs274622) were genotyped. Results GRM3 rs274622 genotype variations significantly predicted MMF strengths (p = 0.009), with C carriers exhibiting significantly larger MMF strengths in both hemispheres compared to the TT subjects. Conclusions These results suggest that variations in GRM3 genotype modulate the auditory cortical response to phoneme change in humans. MMN/MMF, particularly those in response to speech sounds, may be a promising and sensitive intermediate phenotype for clarifying glutamatergic dysfunction in schizophrenia.
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Affiliation(s)
- Yuki Kawakubo
- Department of Child Neuropsychiatry, University of Tokyo, Tokyo, Japan.
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Sodhi MS, Simmons M, McCullumsmith R, Haroutunian V, Meador-Woodruff JH. Glutamatergic gene expression is specifically reduced in thalamocortical projecting relay neurons in schizophrenia. Biol Psychiatry 2011; 70:646-54. [PMID: 21549355 PMCID: PMC3176961 DOI: 10.1016/j.biopsych.2011.02.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 01/28/2011] [Accepted: 02/22/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Impairment of glutamate neurons that relay sensory and cognitive information from the medial dorsal thalamus to the dorsolateral prefrontal cortex and other cortical regions may contribute to the pathophysiology of schizophrenia. In this study, we have assessed the cell-specific expression of glutamatergic transcripts in the medial dorsal thalamus. METHODS We used laser capture microdissection to harvest two populations of medial dorsal thalamic cells, one enriched with glutamatergic relay neurons and the other with gamma-aminobutyric acidergic neurons and astroglia, from postmortem brains of subjects with schizophrenia (n = 14) and a comparison group (n = 20). Quantitative polymerase chain reaction of extracted RNA was used to assay gene expression in the different cell populations. RESULTS The transcripts encoding the ionotropic glutamate receptor subunits NR2D, GluR3, GluR6, GluR7, and the intracellular proteins GRIP1 and SynGAP1 were significantly decreased in relay neurons but not in the mixed glial and interneuron population in schizophrenia. CONCLUSIONS Our data suggest that reduced ionotropic glutamatergic expression occurs selectively in neurons, which give rise to the cortical projections of the medial dorsal thalamus in schizophrenia, rather than in thalamic cells that function locally. Our findings indicate that glutamatergic innervation is dysfunctional in the circuitry between the medial dorsal thalamus and cortex.
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Affiliation(s)
- Monsheel S. Sodhi
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA,Dept. Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, 900 S Ashland Ave, Chicago, Illinois 60607-4067, USA,Correspondence should be addressed to: Monsheel Sodhi Ph.D., 900 S. Ashland Ave. Chicago IL 60607-4067, USA, Tel: +1-312-355-5949, Fax: +1-312-413-9303,
| | - Micah Simmons
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
| | - Robert McCullumsmith
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
| | - Vahram Haroutunian
- Dept. Psychiatry, The Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, New York 10029-6574, USA
| | - James H. Meador-Woodruff
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
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Study of novel selective mGlu2 agonist in the temporo-ammonic input to CA1 neurons reveals reduced mGlu2 receptor expression in a Wistar substrain with an anxiety-like phenotype. J Neurosci 2011; 31:6721-31. [PMID: 21543601 DOI: 10.1523/jneurosci.0418-11.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Group II metabotropic receptors (mGluRs) regulate central synaptic transmission by modulating neurotransmitter release. However, the lack of pharmacological tools differentiating between mGlu2 and mGlu3 receptors has hampered identification of the roles of these two receptor subtypes. We have used LY395756 [(1SR,2SR,4RS,5RS,6SR)-2-amino-4-methylbicyclo[3.1.0]-hexane2,6-dicarboxylic], an agonist at mGlu2 receptors and an antagonist at mGlu3 receptors in cell lines, to investigate the roles of these receptors in the temporo-ammonic path from entorhinal cortex to CA1-stratum lacunosum moleculare in rat hippocampal slices. Surprisingly, the degree of inhibition of the field EPSP induced by LY395756 fell into two distinct groups, with EC(50) values of <1 μm and >100 μm. In "sensitive" slices, LY395756 had additive actions with a mixed mGlu2/mGlu3 agonist, DCG-IV [(2S,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)glycine], whereas in "insensitive" slices, LY395756 reduced the effect of DCG-IV, with an IC(50) of ∼1 μm. This separation into sensitive and insensitive slices could be explained by LY395756 acting as an mGlu2 agonist and mGlu3 antagonist, respectively, a finding supported by data from mice lacking these receptors. The heterogeneity was correlated with differences in expression levels of mGlu2 receptors within our Wistar colony and other Wistar substrains. The initial search for a behavioral correlate indicated that rats lacking mGlu2 receptors showed anxiety-like behavior in open-field and elevated plus maze assays. These findings have implications for rat models of psychiatric disease and are especially pertinent given that mGlu2 receptors are targets for compounds under development for anxiety.
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Enhancement of CA3 hippocampal network activity by activation of group II metabotropic glutamate receptors. Proc Natl Acad Sci U S A 2011; 108:9993-7. [PMID: 21628565 DOI: 10.1073/pnas.1100548108] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Impaired function or expression of group II metabotropic glutamate receptors (mGluRIIs) is observed in brain disorders such as schizophrenia. This class of receptor is thought to modulate activity of neuronal circuits primarily by inhibiting neurotransmitter release. Here, we characterize a postsynaptic excitatory response mediated by somato-dendritic mGluRIIs in hippocampal CA3 pyramidal cells and in stratum oriens interneurons. The specific mGluRII agonists DCG-IV or LCCG-1 induced an inward current blocked by the mGluRII antagonist LY341495. Experiments with transgenic mice revealed a significant reduction of the inward current in mGluR3(-/-) but not in mGluR2(-/-) mice. The excitatory response was associated with periods of synchronized activity at theta frequency. Furthermore, cholinergically induced network oscillations exhibited decreased frequency when mGluRIIs were blocked. Thus, our data indicate that hippocampal responses are modulated not only by presynaptic mGluRIIs that reduce glutamate release but also by postsynaptic mGluRIIs that depolarize neurons and enhance CA3 network activity.
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Inducible expression of G protein-coupled receptors in transfected cells. Methods Mol Biol 2011. [PMID: 21607849 DOI: 10.1007/978-1-61779-126-0_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Biochemical or pharmacological studies of G protein-coupled receptors (GPCRs) are widely conducted in transfected mammalian cells. A variety of commercially available systems allow the generation of stable cell-lines in which expression of the recombinant receptor can be induced on addition of a defined chemical to the culture medium, which operates as a control switch for the transcription of the cloned sequence. Such systems offer the possibility to induce graded levels of receptor expression in the experimental model, or to induce an abrupt downregulation of receptor expression during the maintenance of the cell-line. This chapter provides an overview of the different systems available and provides methods for the generation and validation of stably transfected cell-lines expressing the GPCR of choice.
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Sutton LP, Rushlow WJ. Regulation of Akt and Wnt signaling by the group II metabotropic glutamate receptor antagonist LY341495 and agonist LY379268. J Neurochem 2011; 117:973-83. [PMID: 21477044 DOI: 10.1111/j.1471-4159.2011.07268.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Metabotropic glutamate receptors 2/3 (mGlu(2/3)) have been implicated in schizophrenia and as a novel treatment target for schizophrenia. The current study examined whether mGlu(2/3) regulates Akt (protein kinase B) and Wnt (Wingless/Int-1) signaling, two cascades associated with schizophrenia and modified by antipsychotics. Western blotting revealed increases in phosphorylated Akt (pAkt) and phosphorylated glycogen synthase kinase-3 (pGSK-3) following acute and repeated treatment of LY379268 (mGlu(2/3) agonist), whereas increases in dishevelled-2 (Dvl-2), dishevelled-3 (Dvl-3), GSK-3 and β-catenin were only observed following repeated treatment. LY341495 (mGlu(2/3) antagonist) induced the opposite response compared with LY379268. Co-immunoprecipitation experiments showed an association between the mGlu(2/3) complex and Dvl-2 providing a possible mechanism to explain how the mGlu(2/3) can mediate changes in Wnt signaling. However, there was no association between the mGlu(2/3) complex and Akt suggesting that changes in Akt signaling following LY341495 and LY379268 treatments may not be directly mediated by the mGlu(2/3) . Finally, an increase in locomotor activity induced by LY341495 treatment correlated with increased pAkt and pGSK-3 levels and was attenuated by the administration of the GSK-3 inhibitor, SB216763. Overall, the results suggest that mGlu(2/3) regulates Akt and Wnt signaling and LY379268 treatment has overlapping effects with D(2) dopamine receptor antagonists (antipsychotic drugs).
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Affiliation(s)
- Laurie P Sutton
- Department of Anatomy & Cell Biology, University of Western Ontario and the London Health Sciences Centre, London, Ontario, Canada
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Density of metabotropic glutamate receptors 2 and 3 (mGluR2/3) in the dorsolateral prefrontal cortex does not differ with schizophrenia diagnosis but decreases with age. Schizophr Res 2011; 128:56-60. [PMID: 21334855 DOI: 10.1016/j.schres.2011.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/11/2011] [Accepted: 01/11/2011] [Indexed: 11/20/2022]
Abstract
Metabotropic glutamate receptors 2 and 3 (mGluR2/3) have been shown as efficient targets for antipsychotic intervention. We therefore investigated the receptor density of mGluR2/3 in the dorsolateral prefrontal cortex (dlPFC; Brodman area 46) of schizophrenia/schizoaffective patients (n=37) and matched controls (n=37) using receptor autoradiography. No difference in mGluR2/3 density was identified in relation to schizophrenia diagnosis. Overall and in individual groups, a negative correlation of mGluR2/3 density and age at death has been found. These and previous results suggest that density of mGluR2/3 in the dlPFC is less likely to impact on the efficiency of the mGluR2/3 agonist in treating schizophrenia symptoms.
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Corti C, Xuereb JH, Crepaldi L, Corsi M, Michielin F, Ferraguti F. Altered levels of glutamatergic receptors and Na+/K+ ATPase-α1 in the prefrontal cortex of subjects with schizophrenia. Schizophr Res 2011; 128:7-14. [PMID: 21353485 DOI: 10.1016/j.schres.2011.01.021] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 01/24/2011] [Accepted: 01/28/2011] [Indexed: 12/31/2022]
Abstract
Evidence has accumulated over the past years that dysregulation of glutamatergic neurotransmission maybe implicated in the pathophysiology of schizophrenia. Glutamate acts on two major classes of receptors: ionotropic receptors, which are ligand-gated ion channels, and metabotropic receptors (mGluRs), coupled to heterotrimeric G-proteins. Although several pharmacological evidences point to abnormal glutamatergic transmission in schizophrenia, changes in the expression of glutamatergic receptors in the prefrontal cortex of patients with schizophrenia remains equivocal. In the present work, we have investigated glutamatergic neurotransmission in schizophrenia by assessing the expression in Brodmann Area 10 of mGluR5, the AMPA receptor subunits GluR1 and GluR2, and Na(+)/K(+) ATPase-α1, a potential modulator of glutamate uptake in the brain. Semiquantitative analysis of the expression of these proteins from postmortem brains revealed a particularly prominent reduction of GluR1 and GluR2 expression in patients with schizophrenia vs the control group. Conversely, we observed an up-regulation in the levels of Na(+)/K(+) ATPase-α1 expression. Finally, no change in the protein levels of mGluR5 was observed in schizophrenia. Our findings support and expand the hypothesis of glutamatergic dysfunction in prefrontal cortex in the pathophysiology of schizophrenia.
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Affiliation(s)
- Corrado Corti
- Dept. Biology, Psychiatry Centre of Excellence in Drug Discovery, GlaxoSmithKline Medicines Research Centre, Verona, Italy
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Nicoletti F, Bockaert J, Collingridge GL, Conn PJ, Ferraguti F, Schoepp DD, Wroblewski JT, Pin JP. Metabotropic glutamate receptors: from the workbench to the bedside. Neuropharmacology 2010; 60:1017-41. [PMID: 21036182 DOI: 10.1016/j.neuropharm.2010.10.022] [Citation(s) in RCA: 476] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 10/15/2010] [Accepted: 10/21/2010] [Indexed: 12/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors were discovered in the mid 1980s and originally described as glutamate receptors coupled to polyphosphoinositide hydrolysis. Almost 6500 articles have been published since then, and subtype-selective mGlu receptor ligands are now under clinical development for the treatment of a variety of disorders such as Fragile-X syndrome, schizophrenia, Parkinson's disease and L-DOPA-induced dyskinesias, generalized anxiety disorder, chronic pain, and gastroesophageal reflux disorder. Prof. Erminio Costa was linked to the early times of the mGlu receptor history, when a few research groups challenged the general belief that glutamate could only activate ionotropic receptors and all metabolic responses to glutamate were secondary to calcium entry. This review moves from those nostalgic times to the most recent advances in the physiology and pharmacology of mGlu receptors, and highlights the role of individual mGlu receptor subtypes in the pathophysiology of human disorders. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.
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Affiliation(s)
- F Nicoletti
- Department of Physiology and Pharmacology, University of Rome, Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
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Krystal JH, Mathew SJ, D'Souza DC, Garakani A, Gunduz-Bruce H, Charney DS. Potential psychiatric applications of metabotropic glutamate receptor agonists and antagonists. CNS Drugs 2010; 24:669-93. [PMID: 20658799 DOI: 10.2165/11533230-000000000-00000] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Drugs acting at metabotropic glutamate receptors (mGluRs) are among the most promising agents under development for the treatment of psychiatric disorders. The research in this area is at a relatively early stage, as there are no drugs acting at mGluRs that have been approved for the treatment of any psychiatric disorder. However, in the areas of schizophrenia, anxiety disorders and mood disorders, research conducted in animal models appears to translate well into efficacy in human laboratory-based models of psychopathology and in preliminary clinical trials. Further, the genes coding for mGluRs are implicated in the risk for a growing number of psychiatric disorders. This review highlights the best studied mGluR strategies for psychiatry, based on human molecular genetics, studies in animal models and preliminary clinical trials. It describes the potential value of mGluR2 and mGluR5 agonists and positive allosteric modulators for the treatment of schizophrenia. It also reviews evidence that group II mGluR agonists and positive allosteric modulators as well as group I mGluR antagonists might also treat anxiety disorders and some forms of depression, while mGluR2 and group I mGluR antagonists (particularly mGluR5 antagonists) might have antidepressant properties. This review also links growing insights into the role of glutamate in the pathophysiology of these disorders to hypothesized mGluR-related treatment mechanisms.
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Affiliation(s)
- John H Krystal
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA.
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Metabotropic glutamate2/3 (mGlu2/3) receptors, schizophrenia and cognition. Eur J Pharmacol 2010; 639:81-90. [PMID: 20371229 DOI: 10.1016/j.ejphar.2010.02.058] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 01/19/2010] [Accepted: 02/04/2010] [Indexed: 10/19/2022]
Abstract
Recently, a metabotropic glutamate(2/3) (mGlu(2/3)) receptor agonist prodrug was found to improve both the positive and negative symptoms of schizophrenic patients. Thus far, however, definitive data directly describing the effects of mGlu(2/3) receptor agonists on cognition in schizophrenic patients is lacking. In this review, we will first describe the location of mGlu(2) and mGlu(3) receptors with respect to cellular compartments in cortical circuits of both the prefrontal cortex and the hippocampal formation. We will then address the function of mGlu(2) and mGlu(3) receptors in both macrocircuits and microcircuits involving the prefrontal cortex and hippocampal formation. Imbalance within and between macrocircuits, including the re-entrant cortico-striatal-thalamic loops; the trisynaptic organization of the hippocampal formation; and the ascending reticular activating system/monoaminergic brainstem nuclei projecting throughout the neural axis, appear central to understanding both the pathophysiology and therapeutic approaches for treating the pervasive cognitive dysfunction associated with schizophrenia. Understanding the function of mGlu(2) and mGlu(3) receptors in these macrocircuits also may provide answers to currently conflicting data between some preclinical studies and the clinical studies seemingly predicting impairment and improvement in cognitive function with activation of mGlu(2) and mGlu(3) receptors.
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Group II metabotropic glutamate receptor agonists as a potential drug for schizophrenia. Eur J Pharmacol 2010; 639:59-66. [PMID: 20371240 DOI: 10.1016/j.ejphar.2009.12.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 11/19/2009] [Accepted: 12/07/2009] [Indexed: 10/19/2022]
Abstract
Metabotropic glutamate receptors (mGlu receptors), with their unique signaling systems and pharmacological characteristics, have emerged as a new topic in excitatory amino acid research. Among them, the unique distribution of group II mGlu receptors, such as mGlu(2) and mGlu(3) receptors, and the involvement of these receptors in the regulation of neurotransmission are particularly interesting. Recently, potent agonists for mGlu(2/3) receptor have been synthesized, and their pharmacological roles have been intensively investigated using animal models. mGlu(2/3) receptors clearly have crucial roles in the central nervous system, and accumulating evidence in both rodents and human studies has suggested that agonists for mGlu(2/3) receptors may be beneficial for the treatment of psychiatric disorders such as schizophrenia. Possible neuronal circuits through which mGlu(2/3) receptor agonists exert their pharmacological effects have also been investigated.
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Cherlyn SYT, Woon PS, Liu JJ, Ong WY, Tsai GC, Sim K. Genetic association studies of glutamate, GABA and related genes in schizophrenia and bipolar disorder: a decade of advance. Neurosci Biobehav Rev 2010; 34:958-77. [PMID: 20060416 DOI: 10.1016/j.neubiorev.2010.01.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 01/01/2010] [Accepted: 01/04/2010] [Indexed: 12/31/2022]
Abstract
Schizophrenia (SZ) and bipolar disorder (BD) are debilitating neurobehavioural disorders likely influenced by genetic and non-genetic factors and which can be seen as complex disorders of synaptic neurotransmission. The glutamatergic and GABAergic neurotransmission systems have been implicated in both diseases and we have reviewed extensive literature over a decade for evidence to support the association of glutamate and GABA genes in SZ and BD. Candidate-gene based population and family association studies have implicated some ionotrophic glutamate receptor genes (GRIN1, GRIN2A, GRIN2B and GRIK3), metabotropic glutamate receptor genes (such as GRM3), the G72/G30 locus and GABAergic genes (e.g. GAD1 and GABRB2) in both illnesses to varying degrees, but further replication studies are needed to validate these results. There is at present no consensus on specific single nucleotide polymorphisms or haplotypes associated with the particular candidate gene loci in these illnesses. The genetic architecture of glutamate systems in bipolar disorder need to be better studied in view of recent data suggesting an overlap in the genetic aetiology of SZ and BD. There is a pressing need to integrate research platforms in genomics, epistatic models, proteomics, metabolomics, neuroimaging technology and translational studies in order to allow a more integrated understanding of glutamate and GABAergic signalling processes and aberrations in SZ and BD as well as their relationships with clinical presentations and treatment progress over time.
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Affiliation(s)
- Suat Ying Tan Cherlyn
- Institute of Mental Health/Woodbridge Hospital, 10 Buangkok View, Singapore 539747, Singapore
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Moreno JL, Sealfon SC, González-Maeso J. Group II metabotropic glutamate receptors and schizophrenia. Cell Mol Life Sci 2009; 66:3777-85. [PMID: 19707855 PMCID: PMC2792875 DOI: 10.1007/s00018-009-0130-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 07/10/2009] [Accepted: 08/11/2009] [Indexed: 12/18/2022]
Abstract
Schizophrenia is one of the most common mental illnesses, with hereditary and environmental factors important for its etiology. All antipsychotics have in common a high affinity for monoaminergic receptors. Whereas hallucinations and delusions usually respond to typical (haloperidol-like) and atypical (clozapine-like) monoaminergic antipsychotics, their efficacy in improving negative symptoms and cognitive deficits remains inadequate. In addition, devastating side effects are a common characteristic of monoaminergic antipsychotics. Recent biochemical, preclinical and clinical findings support group II metabotropic glutamate receptors (mGluR2 and mGluR3) as a new approach to treat schizophrenia. This paper reviews the status of general knowledge of mGluR2 and mGluR3 in the psychopharmacology, genetics and neuropathology of schizophrenia.
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Affiliation(s)
- José L. Moreno
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029 USA
- Division of Basic Neuroscience, Mount Sinai School of Medicine, New York, NY 10029 USA
| | - Stuart C. Sealfon
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029 USA
- Center for Translational Systems Biology, Mount Sinai School of Medicine, New York, NY 10029 USA
| | - Javier González-Maeso
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029 USA
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029 USA
- Division of Basic Neuroscience, Mount Sinai School of Medicine, New York, NY 10029 USA
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