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Provenzano F, Torazza C, Bonifacino T, Bonanno G, Milanese M. The Key Role of Astrocytes in Amyotrophic Lateral Sclerosis and Their Commitment to Glutamate Excitotoxicity. Int J Mol Sci 2023; 24:15430. [PMID: 37895110 PMCID: PMC10607805 DOI: 10.3390/ijms242015430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/12/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023] Open
Abstract
In the last two decades, there has been increasing evidence supporting non-neuronal cells as active contributors to neurodegenerative disorders. Among glial cells, astrocytes play a pivotal role in driving amyotrophic lateral sclerosis (ALS) progression, leading the scientific community to focus on the "astrocytic signature" in ALS. Here, we summarized the main pathological mechanisms characterizing astrocyte contribution to MN damage and ALS progression, such as neuroinflammation, mitochondrial dysfunction, oxidative stress, energy metabolism impairment, miRNAs and extracellular vesicles contribution, autophagy dysfunction, protein misfolding, and altered neurotrophic factor release. Since glutamate excitotoxicity is one of the most relevant ALS features, we focused on the specific contribution of ALS astrocytes in this aspect, highlighting the known or potential molecular mechanisms by which astrocytes participate in increasing the extracellular glutamate level in ALS and, conversely, undergo the toxic effect of the excessive glutamate. In this scenario, astrocytes can behave as "producers" and "targets" of the high extracellular glutamate levels, going through changes that can affect themselves and, in turn, the neuronal and non-neuronal surrounding cells, thus actively impacting the ALS course. Moreover, this review aims to point out knowledge gaps that deserve further investigation.
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Affiliation(s)
- Francesca Provenzano
- Department of Pharmacy (DIFAR), University of Genoa, 16148 Genova, Italy; (F.P.); (C.T.); (G.B.); (M.M.)
| | - Carola Torazza
- Department of Pharmacy (DIFAR), University of Genoa, 16148 Genova, Italy; (F.P.); (C.T.); (G.B.); (M.M.)
| | - Tiziana Bonifacino
- Department of Pharmacy (DIFAR), University of Genoa, 16148 Genova, Italy; (F.P.); (C.T.); (G.B.); (M.M.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
| | - Giambattista Bonanno
- Department of Pharmacy (DIFAR), University of Genoa, 16148 Genova, Italy; (F.P.); (C.T.); (G.B.); (M.M.)
| | - Marco Milanese
- Department of Pharmacy (DIFAR), University of Genoa, 16148 Genova, Italy; (F.P.); (C.T.); (G.B.); (M.M.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
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2
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Neves D, Salazar IL, Almeida RD, Silva RM. Molecular mechanisms of ischemia and glutamate excitotoxicity. Life Sci 2023; 328:121814. [PMID: 37236602 DOI: 10.1016/j.lfs.2023.121814] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/05/2023] [Accepted: 05/23/2023] [Indexed: 05/28/2023]
Abstract
Excitotoxicity is classically defined as the neuronal damage caused by the excessive release of glutamate, and subsequent activation of excitatory plasma membrane receptors. In the mammalian brain, this phenomenon is mainly driven by excessive activation of glutamate receptors (GRs). Excitotoxicity is common to several chronic disorders of the Central Nervous System (CNS) and is considered the primary mechanism of neuronal loss of function and cell death in acute CNS diseases (e.g. ischemic stroke). Multiple mechanisms and pathways lead to excitotoxic cell damage including pro-death signaling cascade events downstream of glutamate receptors, calcium (Ca2+) overload, oxidative stress, mitochondrial impairment, excessive glutamate in the synaptic cleft as well as altered energy metabolism. Here, we review the current knowledge on the molecular mechanisms that underlie excitotoxicity, emphasizing the role of Nicotinamide Adenine Dinucleotide (NAD) metabolism. We also discuss novel and promising therapeutic strategies to treat excitotoxicity, highlighting recent clinical trials. Finally, we will shed light on the ongoing search for stroke biomarkers, an exciting and promising field of research, which may improve stroke diagnosis, prognosis and allow better treatment options.
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Affiliation(s)
- Diogo Neves
- iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Ivan L Salazar
- Multidisciplinary Institute of Ageing, MIA - Portugal, University of Coimbra, Coimbra, Portugal
| | - Ramiro D Almeida
- iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal; CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
| | - Raquel M Silva
- iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal; Universidade Católica Portuguesa, Faculdade de Medicina Dentária, Centro de Investigação Interdisciplinar em Saúde, Viseu, Portugal.
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3
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Balbi M, Bonanno G, Bonifacino T, Milanese M. The Physio-Pathological Role of Group I Metabotropic Glutamate Receptors Expressed by Microglia in Health and Disease with a Focus on Amyotrophic Lateral Sclerosis. Int J Mol Sci 2023; 24:ijms24065240. [PMID: 36982315 PMCID: PMC10048889 DOI: 10.3390/ijms24065240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/30/2023] Open
Abstract
Microglia cells are the resident immune cells of the central nervous system. They act as the first-line immune guardians of nervous tissue and central drivers of neuroinflammation. Any homeostatic alteration that can compromise neuron and tissue integrity could activate microglia. Once activated, microglia exhibit highly diverse phenotypes and functions related to either beneficial or harmful consequences. Microglia activation is associated with the release of protective or deleterious cytokines, chemokines, and growth factors that can in turn determine defensive or pathological outcomes. This scenario is complicated by the pathology-related specific phenotypes that microglia can assume, thus leading to the so-called disease-associated microglia phenotypes. Microglia express several receptors that regulate the balance between pro- and anti-inflammatory features, sometimes exerting opposite actions on microglial functions according to specific conditions. In this context, group I metabotropic glutamate receptors (mGluRs) are molecular structures that may contribute to the modulation of the reactive phenotype of microglia cells, and this is worthy of exploration. Here, we summarize the role of group I mGluRs in shaping microglia cells' phenotype in specific physio-pathological conditions, including some neurodegenerative disorders. A significant section of the review is specifically focused on amyotrophic lateral sclerosis (ALS) since it represents an entirely unexplored topic of research in the field.
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Affiliation(s)
- Matilde Balbi
- Department of Pharmacy (DIFAR), University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
| | - Giambattista Bonanno
- Department of Pharmacy (DIFAR), University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Tiziana Bonifacino
- Department of Pharmacy (DIFAR), University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
| | - Marco Milanese
- Department of Pharmacy (DIFAR), University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
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4
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Tanaka M, Shigetomi E, Parajuli B, Nagatomo H, Shinozaki Y, Hirayama Y, Saito K, Kubota Y, Danjo Y, Lee JH, Kim SK, Nabekura J, Koizumi S. Adenosine A 2B receptor down-regulates metabotropic glutamate receptor 5 in astrocytes during postnatal development. Glia 2021; 69:2546-2558. [PMID: 34339538 DOI: 10.1002/glia.24006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 11/07/2022]
Abstract
Metabotropic glutamate receptor 5 (mGluR5) in astrocytes is a key molecule for controlling synapse remodeling. Although mGluR5 is abundant in neonatal astrocytes, its level is gradually down-regulated during development and is almost absent in the adult. However, in several pathological conditions, mGluR5 re-emerges in adult astrocytes and contributes to disease pathogenesis by forming uncontrolled synapses. Thus, controlling mGluR5 expression in astrocyte is critical for several diseases, but the mechanism that regulates mGluR5 expression remains unknown. Here, we show that adenosine triphosphate (ATP)/adenosine-mediated signals down-regulate mGluR5 in astrocytes. First, in situ Ca2+ imaging of astrocytes in acute cerebral slices from post-natal day (P)7-P28 mice showed that Ca2+ responses evoked by (S)-3,5-dihydroxyphenylglycine (DHPG), a mGluR5 agonist, decreased during development, whereas those evoked by ATP or its metabolite, adenosine, increased. Second, ATP and adenosine suppressed expression of the mGluR5 gene, Grm5, in cultured astrocytes. Third, the decrease in the DHPG-evoked Ca2+ responses was associated with down-regulation of Grm5. Interestingly, among several adenosine (P1) receptor and ATP (P2) receptor genes, only the adenosine A2B receptor gene, Adora2b, was up-regulated in the course of development. Indeed, we observed that down-regulation of Grm5 was suppressed in Adora2b knockout astrocytes at P14 and in situ Ca2+ imaging from Adora2b knockout mice indicated that the A2B receptor inhibits mGluR5 expression in astrocytes. Furthermore, deletion of A2B receptor increased the number of excitatory synapse in developmental stage. Taken together, the A2B receptor is critical for down-regulation of mGluR5 in astrocytes, which would contribute to terminate excess synaptogenesis during development.
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Affiliation(s)
- Masayoshi Tanaka
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Bijay Parajuli
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Hiroaki Nagatomo
- Center for Life Science Research, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yuri Hirayama
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Kozo Saito
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yuto Kubota
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yosuke Danjo
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Ji Hwan Lee
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
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5
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Milanese M, Bonifacino T, Torazza C, Provenzano F, Kumar M, Ravera S, Zerbo AR, Frumento G, Balbi M, Nguyen TPN, Bertola N, Ferrando S, Viale M, Profumo A, Bonanno G. Blocking glutamate mGlu 5 receptors with the negative allosteric modulator CTEP improves disease course in SOD1 G93A mouse model of amyotrophic lateral sclerosis. Br J Pharmacol 2021; 178:3747-3764. [PMID: 33931856 PMCID: PMC8457068 DOI: 10.1111/bph.15515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 02/22/2021] [Accepted: 04/20/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE The pathogenesis of amyotrophic lateral sclerosis (ALS) is not fully clarified, although excessive glutamate (Glu) transmission and the downstream cytotoxic cascades are major mechanisms for motor neuron death. Two metabotropic glutamate receptors (mGlu1 and mGlu5 ) are overexpressed in ALS and regulate cellular disease processes. Expression and function of mGlu5 receptors are altered at early symptomatic stages in the SOD1G93A mouse model of ALS and knockdown of mGlu5 receptors in SOD1G93A mice improved disease progression. EXPERIMENTAL APPROACH We treated male and female SOD1G93A mice with 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine (CTEP), an orally available mGlu5 receptor negative allosteric modulator (NAM), using doses of 2 mg·kg-1 per 48 h or 4 mg·kg-1 per 24 h from Day 90, an early symptomatic disease stage. Disease progression was studied by behavioural and histological approaches. KEY RESULTS CTEP dose-dependently ameliorated clinical features in SOD1G93A mice. The lower dose increased survival and improved motor skills in female mice, with barely positive effects in male mice. Higher doses significantly ameliorated disease symptoms and survival in both males and females, females being more responsive. CTEP also reduced motor neuron death, astrocyte and microglia activation, and abnormal glutamate release in the spinal cord, with equal effects in male and female mice. No differences were also observed in CTEP access to the brain. CONCLUSION AND IMPLICATIONS Our results suggest that mGlu5 receptors are promising targets for the treatment of ALS and highlight mGlu5 receptor NAMs as effective pharmacological tools with translational potential.
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Affiliation(s)
- Marco Milanese
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy.,Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), Genoa, Italy
| | - Tiziana Bonifacino
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy.,Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), Genoa, Italy
| | - Carola Torazza
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Francesca Provenzano
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy.,Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen and German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Mandeep Kumar
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Silvia Ravera
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Arianna Roberta Zerbo
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Giulia Frumento
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Matilde Balbi
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - T P Nhung Nguyen
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Nadia Bertola
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Sara Ferrando
- Department of Earth, Environmental and Life Science, University of Genoa, Genoa, Italy
| | | | - Aldo Profumo
- IRCCS Ospedale policlinico San Martino, Genoa, Italy
| | - Giambattista Bonanno
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy.,IRCCS Ospedale policlinico San Martino, Genoa, Italy
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6
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Bursch F, Kalmbach N, Naujock M, Staege S, Eggenschwiler R, Abo-Rady M, Japtok J, Guo W, Hensel N, Reinhardt P, Boeckers TM, Cantz T, Sterneckert J, Van Den Bosch L, Hermann A, Petri S, Wegner F. Altered calcium dynamics and glutamate receptor properties in iPSC-derived motor neurons from ALS patients with C9orf72, FUS, SOD1 or TDP43 mutations. Hum Mol Genet 2020; 28:2835-2850. [PMID: 31108504 DOI: 10.1093/hmg/ddz107] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/02/2019] [Accepted: 05/14/2019] [Indexed: 12/13/2022] Open
Abstract
The fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS) is characterized by a profound loss of motor neurons (MNs). Until now only riluzole minimally extends life expectancy in ALS, presumably by inhibiting glutamatergic neurotransmission and calcium overload of MNs. Therefore, the aim of this study was to investigate the glutamate receptor properties and key aspects of intracellular calcium dynamics in induced pluripotent stem cell (iPSC)-derived MNs from ALS patients with C9orf72 (n = 4 cell lines), fused in sarcoma (FUS) (n = 9), superoxide dismutase 1 (SOD1) (n = 3) or transactive response DNA-binding protein 43 (TDP43) (n = 3) mutations as well as healthy (n = 7 cell lines) and isogenic controls (n = 3). Using calcium imaging, we most frequently observed spontaneous transients in mutant C9orf72 MNs. Basal intracellular calcium levels and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-induced signal amplitudes were elevated in mutant TDP43 MNs. Besides, a majority of mutant TDP43 MNs responded to 3.5-dihydroxyphenylglycine as metabotropic glutamate receptor agonist. Quantitative real-time PCR demonstrated significantly increased expression levels of AMPA and kainate receptors in mutant FUS cells compared to healthy and isogenic controls. Furthermore, the expression of kainate receptors and voltage gated calcium channels in mutant C9orf72 MNs as well as metabotropic glutamate receptors in mutant SOD1 cells was markedly elevated compared to controls. Our data of iPSC-derived MNs from familial ALS patients revealed several mutation-specific alterations in glutamate receptor properties and calcium dynamics that could play a role in ALS pathogenesis and may lead to future translational strategies with individual stratification of neuroprotective ALS treatments.
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Affiliation(s)
- Franziska Bursch
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany.,Center of Systems Neuroscience, Hannover, Germany
| | - Norman Kalmbach
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | - Maximilian Naujock
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | - Selma Staege
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany.,Center of Systems Neuroscience, Hannover, Germany
| | - Reto Eggenschwiler
- Research Group Translational Hepatology and Stem Cell Biology, Cluster of Excellence REBIRTH, Hannover Medical School, 30625 Hannover, Germany
| | | | - Julia Japtok
- Division for Neurodegenerative Diseases, Department of Neurology, Technische Universität Dresden, 01307 Dresden, Germany
| | - Wenting Guo
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, BE-3000 Leuven, Belgium.,Laboratory of Neurobiology, VIB-Center for Brain & Disease Research, BE-3000 Leuven, Belgium
| | - Niko Hensel
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hanover, Germany
| | | | - Tobias M Boeckers
- Institute of Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Tobias Cantz
- Research Group Translational Hepatology and Stem Cell Biology, Cluster of Excellence REBIRTH, Hannover Medical School, 30625 Hannover, Germany
| | | | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, BE-3000 Leuven, Belgium.,Laboratory of Neurobiology, VIB-Center for Brain & Disease Research, BE-3000 Leuven, Belgium
| | - Andreas Hermann
- Division for Neurodegenerative Diseases, Department of Neurology, Technische Universität Dresden, 01307 Dresden, Germany
| | - Susanne Petri
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany.,Center of Systems Neuroscience, Hannover, Germany
| | - Florian Wegner
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany.,Center of Systems Neuroscience, Hannover, Germany
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7
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Bonifacino T, Rebosio C, Provenzano F, Torazza C, Balbi M, Milanese M, Raiteri L, Usai C, Fedele E, Bonanno G. Enhanced Function and Overexpression of Metabotropic Glutamate Receptors 1 and 5 in the Spinal Cord of the SOD1 G93A Mouse Model of Amyotrophic Lateral Sclerosis during Disease Progression. Int J Mol Sci 2019; 20:ijms20184552. [PMID: 31540330 PMCID: PMC6774337 DOI: 10.3390/ijms20184552] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/26/2019] [Accepted: 09/12/2019] [Indexed: 12/11/2022] Open
Abstract
Glutamate (Glu)-mediated excitotoxicity is a major cause of amyotrophic lateral sclerosis (ALS) and our previous work highlighted that abnormal Glu release may represent a leading mechanism for excessive synaptic Glu. We demonstrated that group I metabotropic Glu receptors (mGluR1, mGluR5) produced abnormal Glu release in SOD1G93A mouse spinal cord at a late disease stage (120 days). Here, we studied this phenomenon in pre-symptomatic (30 and 60 days) and early-symptomatic (90 days) SOD1G93A mice. The mGluR1/5 agonist (S)-3,5-Dihydroxyphenylglycine (3,5-DHPG) concentration dependently stimulated the release of [3H]d-Aspartate ([3H]d-Asp), which was comparable in 30- and 60-day-old wild type mice and SOD1G93A mice. At variance, [3H]d-Asp release was significantly augmented in 90-day-old SOD1G93A mice and both mGluR1 and mGluR5 were involved. The 3,5-DHPG-induced [3H]d-Asp release was exocytotic, being of vesicular origin and mediated by intra-terminal Ca2+ release. mGluR1 and mGluR5 expression was increased in Glu spinal cord axon terminals of 90-day-old SOD1G93A mice, but not in the whole axon terminal population. Interestingly, mGluR1 and mGluR5 were significantly augmented in total spinal cord tissue already at 60 days. Thus, function and expression of group I mGluRs are enhanced in the early-symptomatic SOD1G93A mouse spinal cord, possibly participating in excessive Glu transmission and supporting their implication in ALS. Please define all abbreviations the first time they appear in the abstract, the main text, and the first figure or table caption.
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Affiliation(s)
- Tiziana Bonifacino
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa, 16148 Genova, Italy.
| | - Claudia Rebosio
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa, 16148 Genova, Italy.
| | - Francesca Provenzano
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa, 16148 Genova, Italy.
| | - Carola Torazza
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa, 16148 Genova, Italy.
| | - Matilde Balbi
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa, 16148 Genova, Italy.
| | - Marco Milanese
- Department of Pharmacy, Unit of Pharmacology and Toxicology and Center of Excellence for Biomedical Research (CEBR), University of Genoa, 16132 Genova, Italy.
| | - Luca Raiteri
- Department of Pharmacy, Unit of Pharmacology and Toxicology and Center of Excellence for Biomedical Research (CEBR), University of Genoa, 16132 Genova, Italy.
| | - Cesare Usai
- Institute of Biophysics, National Research Council (CNR), 16149 Genova, Italy.
| | - Ernesto Fedele
- Department of Pharmacy, Unit of Pharmacology and Toxicology and Center of Excellence for Biomedical Research (CEBR), University of Genoa, 16132 Genova, Italy.
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, 16132 Genova, Italy.
| | - Giambattista Bonanno
- Department of Pharmacy, Unit of Pharmacology and Toxicology and Center of Excellence for Biomedical Research (CEBR), University of Genoa, 16132 Genova, Italy.
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, 16132 Genova, Italy.
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8
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Bonifacino T, Provenzano F, Gallia E, Ravera S, Torazza C, Bossi S, Ferrando S, Puliti A, Van Den Bosch L, Bonanno G, Milanese M. In-vivo genetic ablation of metabotropic glutamate receptor type 5 slows down disease progression in the SOD1G93A mouse model of amyotrophic lateral sclerosis. Neurobiol Dis 2019; 129:79-92. [DOI: 10.1016/j.nbd.2019.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/19/2019] [Accepted: 05/11/2019] [Indexed: 11/30/2022] Open
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9
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Jordan K, Murphy J, Singh A, Mitchell CS. Astrocyte-Mediated Neuromodulatory Regulation in Preclinical ALS: A Metadata Analysis. Front Cell Neurosci 2018; 12:491. [PMID: 30618638 PMCID: PMC6305074 DOI: 10.3389/fncel.2018.00491] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by progressive degradation of motoneurons in the central nervous system (CNS). Astrocytes are key regulators for inflammation and neuromodulatory signaling, both of which contribute to ALS. The study goal was to ascertain potential temporal changes in astrocyte-mediated neuromodulatory regulation with transgenic ALS model progression: glutamate, GTL-1, GluR1, GluR2, GABA, ChAT activity, VGF, TNFα, aspartate, and IGF-1. We examine neuromodulatory changes in data aggregates from 42 peer-reviewed studies derived from transgenic ALS mixed cell cultures (neurons + astrocytes). For each corresponding experimental time point, the ratio of transgenic to wild type (WT) was found for each compound. ANOVA and a student's t-test were performed to compare disease stages (early, post-onset, and end stage). Glutamate in transgenic SOD1-G93A mixed cell cultures does not change over time (p > 0.05). GLT-1 levels were found to be decreased 23% over WT but only at end-stage (p < 0.05). Glutamate receptors (GluR1, GluR2) in SOD1-G93A were not substantially different from WT, although SOD1-G93A GluR1 decreased by 21% from post-onset to end-stage (p < 0.05). ChAT activity was insignificantly decreased. VGF is decreased throughout ALS (p < 0.05). Aspartate is elevated by 25% in SOD1-G93A but only during end-stage (p < 0.05). TNFα is increased by a dramatic 362% (p < 0.05). Furthermore, principal component analysis identified TNFα as contributing to 55% of the data variance in the first component. Thus, TNFα, which modulates astrocyte regulation via multiple pathways, could be a strategic treatment target. Overall results suggest changes in neuromodulator levels are subtle in SOD1-G93A ALS mixed cell cultures. If excitotoxicity is present as is often presumed, it could be due to ALS cells being more sensitive to small changes in neuromodulation. Hence, seemingly unsubstantial or oscillatory changes in neuromodulators could wreak havoc in ALS cells, resulting in failed microenvironment homeostasis whereby both hyperexcitability and hypoexcitability can coexist. Future work is needed to examine local, spatiotemporal neuromodulatory homeostasis and assess its functional impact in ALS.
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Affiliation(s)
- Kathleen Jordan
- Laboratory for Pathology Dynamics, Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA, United States
| | - Joseph Murphy
- Laboratory for Pathology Dynamics, Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA, United States
| | - Anjanya Singh
- Laboratory for Pathology Dynamics, Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA, United States
- School of Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Cassie S. Mitchell
- Laboratory for Pathology Dynamics, Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA, United States
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10
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Spampinato SF, Copani A, Nicoletti F, Sortino MA, Caraci F. Metabotropic Glutamate Receptors in Glial Cells: A New Potential Target for Neuroprotection? Front Mol Neurosci 2018; 11:414. [PMID: 30483053 PMCID: PMC6243036 DOI: 10.3389/fnmol.2018.00414] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders are characterized by excitotoxicity and neuroinflammation that finally lead to slow neuronal degeneration and death. Although neurons are the principal target, glial cells are important players as they contribute by either exacerbating or dampening the events that lead to neuroinflammation and neuronal damage. A dysfunction of the glutamatergic system is a common event in the pathophysiology of these diseases. Metabotropic glutamate (mGlu) receptors belong to a large family of G protein-coupled receptors largely expressed in neurons as well as in glial cells. They often appear overexpressed in areas involved in neurodegeneration, where they can modulate glutamatergic transmission. Of note, mGlu receptor upregulation may involve microglia or, even more frequently, astrocytes, where their activation causes release of factors potentially able to influence neuronal death. The expression of mGlu receptors has been also reported on oligodendrocytes, a glial cell type specifically involved in the development of multiple sclerosis. Here we will provide a general overview on the possible involvement of mGlu receptors expressed on glial cells in the pathogenesis of different neurodegenerative disorders and the potential use of subtype-selective mGlu receptor ligands as candidate drugs for the treatment of neurodegenerative disorders. Negative allosteric modulators (NAM) of mGlu5 receptors might represent a relevant pharmacological tool to develop new neuroprotective strategies in these diseases. Recent evidence suggests that targeting astrocytes and microglia with positive allosteric modulators (PAM) of mGlu3 receptor or oligodendrocytes with mGlu4 PAMS might represent novel pharmacological approaches for the treatment of neurodegenerative disorders.
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Affiliation(s)
| | - Agata Copani
- Department of Drug Sciences, University of Catania, Catania, Italy.,Institute of Biostructure and Bioimaging, National Research Council, Catania, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,Neuromed, Istituto di Ricovero e Cura a Carattere Scientifico, Pozzilli, Italy
| | - Maria Angela Sortino
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute, Istituto di Ricovero e Cura a Carattere Scientifico, Troina, Italy
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11
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Battaglia G, Bruno V. Metabotropic glutamate receptor involvement in the pathophysiology of amyotrophic lateral sclerosis: new potential drug targets for therapeutic applications. Curr Opin Pharmacol 2018. [DOI: 10.1016/j.coph.2018.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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12
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Bonifacino T, Cattaneo L, Gallia E, Puliti A, Melone M, Provenzano F, Bossi S, Musante I, Usai C, Conti F, Bonanno G, Milanese M. In-vivo effects of knocking-down metabotropic glutamate receptor 5 in the SOD1 G93A mouse model of amyotrophic lateral sclerosis. Neuropharmacology 2017. [PMID: 28645622 DOI: 10.1016/j.neuropharm.2017.06.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder due to loss of upper and lower motor neurons (MNs). The mechanisms of neuronal death are largely unknown, thus prejudicing the successful pharmacological treatment. One major cause for MN degeneration in ALS is represented by glutamate(Glu)-mediated excitotoxicity. We have previously reported that activation of Group I metabotropic Glu receptors (mGluR1 and mGluR5) at glutamatergic spinal cord nerve terminals produces abnormal Glu release in the widely studied SOD1G93A mouse model of ALS. We also demonstrated that halving mGluR1 expression in the SOD1G93A mouse had a positive impact on survival, disease onset, disease progression, and on a number of cellular and biochemical readouts of ALS. We generated here SOD1G93A mice with reduced expression of mGluR5 (SOD1G93AGrm5-/+) by crossing the SOD1G93A mutant mouse with the mGluR5 heterozigous Grm5-/+ mouse. SOD1G93AGrm5-/+ mice showed prolonged survival probability and delayed pathology onset. These effects were associated to enhanced number of preserved MNs, decreased astrocyte and microglia activation, reduced cytosolic free Ca2+ concentration, and regularization of abnormal Glu release in the spinal cord of SOD1G93AGrm5-/+ mice. Unexpectedly, only male SOD1G93AGrm5-/+ mice showed improved motor skills during disease progression vs. SOD1G93A mice, while SOD1G93AGrm5-/+ females did not. These results demonstrate that a lower constitutive level of mGluR5 has a significant positive impact in mice with ALS and support the idea that blocking Group I mGluRs may represent a potentially effective pharmacological approach to the disease.
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Affiliation(s)
- Tiziana Bonifacino
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy
| | - Luca Cattaneo
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy
| | - Elena Gallia
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy
| | - Aldamaria Puliti
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, Via G. Gaslini, 5 - 16147, Genoa, Italy; Centre of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 9 - 16132, Genoa, Italy
| | - Marcello Melone
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Via Tronto 10/a - 60126, Torrette di Ancona, Ancona, Italy; Centre for Neurobiology of Aging, INRCA IRCCS, Via S.Margherita, 5 - 60124, Ancona, Italy
| | - Francesca Provenzano
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy
| | - Simone Bossi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, L.go P. Daneo, 3 - 16132, Genoa, Italy
| | - Ilaria Musante
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, L.go P. Daneo, 3 - 16132, Genoa, Italy
| | - Cesare Usai
- Institute of Biophysics, National Research Council (CNR), Via Darini, 6 - Torre di Francia, 16149, Genoa, Italy
| | - Fiorenzo Conti
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Via Tronto 10/a - 60126, Torrette di Ancona, Ancona, Italy; Centre for Neurobiology of Aging, INRCA IRCCS, Via S.Margherita, 5 - 60124, Ancona, Italy
| | - Giambattista Bonanno
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy; Centre of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 9 - 16132, Genoa, Italy.
| | - Marco Milanese
- Department of Pharmacy, Unit of Pharmacology and Toxicology, University of Genoa Viale Cembrano, 4 - 16148, Genoa, Italy; Centre of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 9 - 16132, Genoa, Italy
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13
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Endothelin-1 Induces Degeneration of Cultured Motor Neurons Through a Mechanism Mediated by Nitric Oxide and PI3K/Akt Pathway. Neurotox Res 2017; 32:58-70. [PMID: 28285347 DOI: 10.1007/s12640-017-9711-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 02/08/2017] [Accepted: 02/23/2017] [Indexed: 12/13/2022]
Abstract
Endothelin-1 (ET-1) is a vasoactive peptide produced by activated astrocytes and microglia and is implicated in initiating and sustaining reactive gliosis in neurodegenerative diseases. We have previously suggested that ET-1 can play a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). Indeed, we reported that this peptide is abundantly expressed in reactive astrocytes in the spinal cord of SOD1-G93A mice and ALS patients and exerts a toxic effect on motor neurons (MNs) in an in vitro model of mixed spinal cord cultures enriched with reactive astrocytes. Here, we explored the possible mechanisms underlying the toxic effect of ET-1 on cultured MNs. We show that ET-1 toxicity is not directly caused by oxidative stress or activation of cyclooxygenase-2 but requires the synthesis of nitric oxide and is mediated by a reduced activation of the phosphoinositide 3-kinase pathway. Furthermore, we observed that ET-1 is also toxic for microglia, although its effect on MNs is independent of the presence of this type of glial cells. Our study confirms that ET-1 may contribute to MN death and corroborates the view that the modulation of ET-1 signaling might be a therapeutic strategy to slow down MN degeneration in ALS.
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14
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Kumar A, Dhull DK, Mishra PS. Therapeutic potential of mGluR5 targeting in Alzheimer's disease. Front Neurosci 2015; 9:215. [PMID: 26106290 PMCID: PMC4460345 DOI: 10.3389/fnins.2015.00215] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/29/2015] [Indexed: 11/13/2022] Open
Abstract
Decades of research dedicated toward Alzheimer's disease (AD) has culminated in much of the current understanding of the neurodegeneration associated with disease. However, delineating the pathophysiology and finding a possible cure for the disease is still wanting. This is in part due to the lack of knowledge pertaining to the connecting link between neurodegenerative and neuroinflammatory pathways. Consequently, the inefficacy and ill-effects of the drugs currently available for AD encourage the need for alternative and safe therapeutic intervention. In this review we highlight the potential of mGluR5, a metabotropic glutamatergic receptor, in understanding the mechanism underlying the neuronal death and neuroinflammation in AD. We also discuss the role of mGlu5 receptor in mediating the neuron-glia interaction in the disease. Finally, we discuss the potential of mGluR5 as target for treating AD.
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Affiliation(s)
- Anil Kumar
- UGC Centre of Advanced Studies, University Institute of Pharmaceutical Sciences, Panjab University Chandigarh, India
| | - Dinesh K Dhull
- UGC Centre of Advanced Studies, University Institute of Pharmaceutical Sciences, Panjab University Chandigarh, India
| | - Pooja S Mishra
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences Bangalore, India
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15
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Battaglia G, Riozzi B, Bucci D, Di Menna L, Molinaro G, Pallottino S, Nicoletti F, Bruno V. Activation of mGlu3 metabotropic glutamate receptors enhances GDNF and GLT-1 formation in the spinal cord and rescues motor neurons in the SOD-1 mouse model of amyotrophic lateral sclerosis. Neurobiol Dis 2015; 74:126-36. [DOI: 10.1016/j.nbd.2014.11.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/29/2014] [Accepted: 11/19/2014] [Indexed: 11/28/2022] Open
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16
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Modulation of glutamate transport and receptor binding by glutamate receptor antagonists in EAE rat brain. PLoS One 2014; 9:e113954. [PMID: 25426719 PMCID: PMC4245246 DOI: 10.1371/journal.pone.0113954] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 11/01/2014] [Indexed: 12/02/2022] Open
Abstract
The etiology of multiple sclerosis (MS) is currently unknown. However, one potential mechanism involved in the disease may be excitotoxicity. The elevation of glutamate in cerebrospinal fluid, as well as changes in the expression of glutamate receptors (iGluRs and mGluRs) and excitatory amino acid transporters (EAATs), have been observed in the brains of MS patients and animals subjected to experimental autoimmune encephalomyelitis (EAE), which is the predominant animal model used to investigate the pathophysiology of MS. In the present paper, the effects of glutamatergic receptor antagonists, including amantadine, memantine, LY 367583, and MPEP, on glutamate transport, the expression of mRNA of glutamate transporters (EAATs), the kinetic parameters of ligand binding to N-methyl-D-aspartate (NMDA) receptors, and the morphology of nerve endings in EAE rat brains were investigated. The extracellular level of glutamate in the brain is primarily regulated by astrocytic glutamate transporter 1 (GLT-1) and glutamate-aspartate transporter (GLAST). Excess glutamate is taken up from the synaptic space and metabolized by astrocytes. Thus, the extracellular level of glutamate decreases, which protects neurons from excitotoxicity. Our investigations showed changes in the expression of EAAT mRNA, glutamate transport (uptake and release) by synaptosomal and glial plasmalemmal vesicle fractions, and ligand binding to NMDA receptors; these effects were partially reversed after the treatment of EAE rats with the NMDA antagonists amantadine and memantine. The antagonists of group I metabotropic glutamate receptors (mGluRs), including LY 367385 and MPEP, did not exert any effect on the examined parameters. These results suggest that disturbances in these mechanisms may play a role in the processes associated with glutamate excitotoxicity and the progressive brain damage in EAE.
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17
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Chantong B, Kratschmar DV, Lister A, Odermatt A. Inhibition of metabotropic glutamate receptor 5 induces cellular stress through pertussis toxin-sensitive Gi-proteins in murine BV-2 microglia cells. J Neuroinflammation 2014; 11:190. [PMID: 25407356 PMCID: PMC4240888 DOI: 10.1186/s12974-014-0190-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 10/30/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Activation of metabotropic glutamate receptor 5 (mGluR5) by (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) was shown to suppress microglia activation and decrease the release of associated pro-inflammatory mediators. In contrast, the consequences of mGluR5 inhibition are less well understood. Here, we used BV-2 cells, retaining key characteristics of primary mouse microglia, to examine whether mGluR5 inhibition by 2-methyl-6-(phenylethynyl)-pyridine (MPEP) enhances cellular stress and production of inflammatory mediators. METHODS BV-2 cells were treated with MPEP, followed by determination of cellular stress using fluorescent dyes and high-content imaging. The expression of inflammatory mediators, endoplasmic reticulum (ER)-stress markers and phosphorylated AMPKα was analyzed by quantitative PCR, ELISA and Western blotting. Additionally, phospholipase C (PLC) activity, cellular ATP content and changes in intracellular free Ca(2+) ([Ca(2+)]i) were measured using luminescence and fluorescence assays. RESULTS Treatment of BV-2 microglia with 100 μM MPEP increased intracellular reactive oxygen species (ROS), mitochondrial superoxide, mitochondrial mass as well as inducible nitric oxide synthase (iNOS) and IL-6 expression. Furthermore, MPEP reduced cellular ATP and induced AMPKα phosphorylation and the expression of the ER-stress markers CHOP, GRP78 and GRP96. The MPEP-dependent effects were preceded by a rapid concentration-dependent elevation of [Ca(2+)]i, following Ca(2+) release from the ER, mainly via inositol triphosphate-induced receptors (IP3R). The MPEP-induced ER-stress could be blocked by pretreatment with the chemical chaperone 4-phenylbutyrate and the Ca(2+) chelator BAPTA-AM. Pretreatment with the AMPK agonist AICAR partially abolished, whilst the inhibitor compound C potentiated, the MPEP-dependent ER-stress. Importantly, the PLC inhibitor U-73122 and the Gi-protein inhibitor pertussis toxin (PTX) blocked the MPEP-induced increase in [Ca(2+)]i. Moreover, pretreatment of microglia with AICAR, BAPTA-AM, U-73122 and PTX prevented the MPEP-induced generation of oxidative stress and inflammatory mediators, further supporting a role for Gi-protein-mediated activation of PLC. CONCLUSIONS The results emphasize the potential pathophysiological role of mGluR5 antagonism in mediating oxidative stress, ER-stress and inflammation through a Ca(2+)-dependent pathway in microglia. The induction of cellular stress and inflammatory mediators involves PTX-sensitive Gi-proteins and subsequent activation of PLC, IP3R and Ca(2+) release from the ER.
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Affiliation(s)
- Boonrat Chantong
- Current address: Department of Preclinical Science and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Phutthamonthon, Nakhonpathom, Thailand.
| | - Denise V Kratschmar
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
| | - Adam Lister
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
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18
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Ranno E, D'Antoni S, Spatuzza M, Berretta A, Laureanti F, Bonaccorso CM, Pellitteri R, Longone P, Spalloni A, Iyer AM, Aronica E, Catania MV. Endothelin-1 is over-expressed in amyotrophic lateral sclerosis and induces motor neuron cell death. Neurobiol Dis 2014; 65:160-71. [PMID: 24423643 DOI: 10.1016/j.nbd.2014.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 12/13/2013] [Accepted: 01/04/2014] [Indexed: 12/25/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive loss of motor neurons (MNs) and astrogliosis. Recent evidence suggests that factors secreted by activated astrocytes might contribute to degeneration of MNs. We focused on endothelin-1 (ET-1), a peptide which is strongly up-regulated in reactive astrocytes under different pathological conditions. We show that ET-1 is abundantly expressed by reactive astrocytes in the spinal cord of the SOD1-G93A mouse model and sporadic ALS patients. To test if ET-1 might play a role in degeneration of MNs, we investigated its effect on MN survival in an in vitro model of mixed rat spinal cord cultures (MSCs) enriched of astrocytes exhibiting a reactive phenotype. ET-1 exerted a toxic effect on MNs in a time- and concentration-dependent manner, with an exposure to 100-200nM ET-1 for 48h resulting in 40-50% MN cell death. Importantly, ET-1 did not induce MN degeneration when administered on cultures treated with AraC (5μM) or grown in a serum-free medium that did not favor astrocyte proliferation and reactivity. We found that both ETA and ETB receptors are enriched in astrocytes in MSCs. The ET-1 toxic effect was mimicked by ET-3 (100nM) and sarafotoxin S6c (10nM), two selective agonists of endothelin-B receptors, and was not additive with that of ET-3 suggesting the involvement of ETB receptors. Surprisingly, however, the ET-1 effect persisted in the presence of the ETB receptor antagonist BQ-788 (200nM-2μM) and was slightly reversed by the ETA receptor antagonist BQ-123 (2μM), suggesting an atypical pharmacological profile of the astrocytic receptors responsible for ET-1 toxicity. The ET-1 effect was not undone by the ionotropic glutamate receptor AMPA antagonist GYKI 52466 (20μM), indicating that it is not caused by an increased glutamate release. Conversely, a 48-hour ET-1 treatment increased MN cell death induced by acute exposure to AMPA (50μM), which is indicative of two distinct pathways leading to neuronal death. Altogether these results indicate that ET-1 exerts a toxic effect on cultured MNs through mechanisms mediated by reactive astrocytes and suggest that ET-1 may contribute to MN degeneration in ALS. Thus, a treatment aimed at lowering ET-1 levels or antagonizing its effect might be envisaged as a potential therapeutic strategy to slow down MN degeneration in this devastating disease.
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Affiliation(s)
- Eugenia Ranno
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy; PhD Program in Neurobiology, University of Catania, Catania, Italy
| | - Simona D'Antoni
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy
| | - Michela Spatuzza
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy
| | - Antonio Berretta
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy
| | - Floriana Laureanti
- Department of Biomedical Sciences, Section of Physiology, University of Catania, Catania, Italy
| | | | - Rosalia Pellitteri
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy
| | - Patrizia Longone
- Molecular Neurobiology Unit, Experimental Neurology, Fondazione Santa Lucia, Rome, Italy
| | - Alida Spalloni
- Molecular Neurobiology Unit, Experimental Neurology, Fondazione Santa Lucia, Rome, Italy
| | - Anand M Iyer
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Academic Medical Center, Amsterdam, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands
| | - Maria Vincenza Catania
- Institute of Neurological Sciences, National Research Council (ISN-CNR), Catania, Italy; IRCCS Oasi Maria SS, Troina (EN), Italy.
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Modulation of neurological deficits and expression of glutamate receptors during experimental autoimmune encephalomyelitis after treatment with selected antagonists of glutamate receptors. BIOMED RESEARCH INTERNATIONAL 2013; 2013:186068. [PMID: 23936777 PMCID: PMC3722774 DOI: 10.1155/2013/186068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/02/2013] [Indexed: 12/02/2022]
Abstract
The aim of our investigation was to characterize the role of group I mGluRs and NMDA receptors in pathomechanisms of experimental autoimmune encephalomyelitis (EAE), the rodent model of MS. We tested the effects of LY 367385 (S-2-methyl-4-carboxyphenylglycine, a competitive antagonist of mGluR1), MPEP (2-methyl-6-(phenylethynyl)-pyridine, an antagonist of mGluR5), and the uncompetitive NMDA receptor antagonists amantadine and memantine on modulation of neurological deficits observed in rats with EAE. The neurological symptoms of EAE started at 10-11 days post-injection (d.p.i.) and peaked after 12-13 d.p.i. The protein levels of mGluRs and NMDA did not increase in early phases of EAE (4 d.p.i.), but starting from 8 d.p.i. to 25 d.p.i., we observed a significant elevation of mGluR1 and mGluR5 protein expression by about 20% and NMDA protein expression by about 10% over the control at 25 d.p.i. The changes in protein levels were accompanied by changes in mRNA expression of group I mGluRs and NMDARs. During the late disease phase (20–25 d.p.i.), the mRNA expression levels reached 300% of control values. In contrast, treatment with individual receptor antagonists resulted in a reduction of mRNA levels relative to untreated animals.
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20
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Degos V, Peineau S, Nijboer C, Kaindl AM, Sigaut S, Favrais G, Plaisant F, Teissier N, Gouadon E, Lombet A, Saliba E, Collingridge GL, Maze M, Nicoletti F, Heijnen C, Mantz J, Kavelaars A, Gressens P. G protein-coupled receptor kinase 2 and group I metabotropic glutamate receptors mediate inflammation-induced sensitization to excitotoxic neurodegeneration. Ann Neurol 2013; 73:667-78. [PMID: 23494575 DOI: 10.1002/ana.23868] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 01/03/2013] [Accepted: 02/05/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The concept of inflammation-induced sensitization is emerging in the field of perinatal brain injury, stroke, Alzheimer disease, and multiple sclerosis. However, mechanisms underpinning this process remain unidentified. METHODS We combined in vivo systemic lipopolysaccharide-induced or interleukin (IL)-1β-induced sensitization of neonatal and adult rodent cortical neurons to excitotoxic neurodegeneration with in vitro IL-1β sensitization of human and rodent neurons to excitotoxic neurodegeneration. Within these inflammation-induced sensitization models, we assessed metabotropic glutamate receptors (mGluR) signaling and regulation. RESULTS We demonstrate for the first time that group I mGluRs mediate inflammation-induced sensitization to neuronal excitotoxicity in neonatal and adult neurons across species. Inflammation-induced G protein-coupled receptor kinase 2 (GRK2) downregulation and genetic deletion of GRK2 mimicked the sensitizing effect of inflammation on excitotoxic neurodegeneration. Thus, we identify GRK2 as a potential molecular link between inflammation and mGluR-mediated sensitization. INTERPRETATION Collectively, our findings indicate that inflammation-induced sensitization is universal across species and ages and that group I mGluRs and GRK2 represent new avenues for neuroprotection in perinatal and adult neurological disorders.
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Wu YL, Wang NN, Gu L, Yang HM, Xia N, Zhang H. The suppressive effect of metabotropic glutamate receptor 5 (mGlu5) inhibition on hepatocarcinogenesis. Biochimie 2012; 94:2366-75. [PMID: 22706282 DOI: 10.1016/j.biochi.2012.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/04/2012] [Indexed: 01/23/2023]
Abstract
Metabotropic glutamate receptors (mGlus) are G-protein-coupled receptors playing an important role in the central nervous system (CNS). Recently, mGlus have been identified in peripheral tissues, and aberrant expression or inhibition of the receptors functions in the development of certain cancers. However, the correlation of mGlu activity with hepatocellular carcinoma (HCC) remains unknown. In this study, we analyzed the effects of inhibiting mGlu5 activity in hepatocarcinoma cell lines and a xenograft model. Inactivation of mGlu5 with 2-Methyl-6-(phenylethyl)-pyridine (MPEP), a specific antagonist of the receptor, caused inhibition of cell growth, migration, and invasion of HepG2 and Bel-7402 cells, assessed by MTT assay, ATP production, wound healing, and Boyden chamber assay, respectively. Moreover, inhibition of tumor growth and the potential metastasis of hepatocellular carcinoma were also found in nude mice. Furthermore, mGlu5-mediated extracellular signal-regulated kinase (ERK) phosphorylation has been found to be partially involved in cell growth and migration, as detected by stimulation of (S)-3,5-Dihydroxyphenylglycine (DHPG), an agonist of the receptor, and blockage of MPEP and U0126, an inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (MEK). These data indicate that inhibiting the activity of mGlu5 has the molecular potential to suppress oncogenic actions by blocking downstream effector molecules. The study suggests that mGlu5 activity may contribute to understanding the development of HCC.
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Affiliation(s)
- Yong Le Wu
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
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22
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Transient mGlu5R inhibition enhances the survival of granule cell precursors in the neonatal cerebellum. Neuroscience 2012; 219:271-9. [PMID: 22677205 DOI: 10.1016/j.neuroscience.2012.05.064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/28/2012] [Indexed: 12/31/2022]
Abstract
The generation of the most abundant neurons of the cerebellum, the granule cells, relies on a balance between clonal expansion and apoptosis during the first 10 days after birth in the external germinal layer (EGL). The amino acid glutamate controls such critical phases of cell development in other systems through specific receptors such as metabotropic glutamate receptor 5 (mGlu(5)R). However, the function of mGlu(5)Rs on the proliferation and survival of granule cell precursors (GCPs) remains elusive. We found mGlu(5)R mRNA transcripts in EGL using RT-PCR and observed mGlu(5)R-mediated Ca(2+) responses in GCPs in acute slices as early as postnatal day (P) 2-3. Using in vivo injections of the selective non-competitive mGlu(5)R antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) in P7-P9 mice, we found a 20% increase in the number of proliferative GCPs labeled at P7 with the S-phase marker bromodeoxyuridine (BrdU), but no increase in cell proliferation examined 2h following a BrdU injection. Furthermore, similar treatments led to a significant 70% decrease in the number of apoptotic GCPs in the EGL as determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. In contrast, in vivo treatment with the mGlu(5)R agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) resulted in a ∼60% increase in the number of TUNEL-labeled GCPs compared to control. These findings identify a unique role for glutamate acting at mGlu(5)Rs as a functional switch regulating GCP survival in the EGL, thus controlling the total number of cerebellar granule cells produced.
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Schäfer S, Calas AG, Vergouts M, Hermans E. Immunomodulatory influence of bone marrow-derived mesenchymal stem cells on neuroinflammation in astrocyte cultures. J Neuroimmunol 2012; 249:40-8. [PMID: 22633273 DOI: 10.1016/j.jneuroim.2012.04.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/23/2012] [Accepted: 04/26/2012] [Indexed: 11/28/2022]
Abstract
The therapeutic benefits associated with mesenchymal stem cells (MSCs) largely result from their immunomodulatory and neurotrophic properties. In this study, we evaluated the effects of MSCs on astrocyte cultures exposed to lipopolysaccharide. In response to this inflammatory trigger, astrocytes showed an increased expression of pro-inflammatory genes (IL-1β, TNFα, IL-6), which was attenuated by pre-exposure to MSC conditioned medium. Furthermore, mediators released by MSCs increased cell proliferation and altered the regulation of intermediate filaments (GFAP, vimentin), pro-inflammatory enzymes (iNOS, COX-2) and receptors (TLR4, CD14, mGluR3, mGluR5). These data demonstrate that MSCs influence diverse cell types participating in the response to neuroinflammation.
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Affiliation(s)
- Sabrina Schäfer
- Institute of Neuroscience (IoNS), Group of Neuropharmacology, Université catholique de Louvain, Av. Hippocrate 54, Brussels, Belgium
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Giribaldi F, Milanese M, Bonifacino T, Anna Rossi PI, Di Prisco S, Pittaluga A, Tacchetti C, Puliti A, Usai C, Bonanno G. Group I metabotropic glutamate autoreceptors induce abnormal glutamate exocytosis in a mouse model of amyotrophic lateral sclerosis. Neuropharmacology 2012; 66:253-63. [PMID: 22634363 DOI: 10.1016/j.neuropharm.2012.05.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 04/26/2012] [Accepted: 05/13/2012] [Indexed: 10/28/2022]
Abstract
Glutamate-mediated excitotoxicity plays a major role in ALS and reduced astrocytic glutamate transport was suggested as a cause. Based on previous work we have proposed that abnormal release may represent another source of excessive glutamate. In this line, here we studied the modulation of glutamate release in ALS by Group I metabotropic glutamate (mGlu) receptors, that comprise mGlu1 and mGlu5 members. Synaptosomes from the lumbar spinal cord of SOD1/G93A mice, a widely used murine model for human ALS, and controls were used in release, confocal or electron microscopy and Western blot experiments. Concentrations of the mGlu1/5 receptor agonist 3,5-DHPG >0.3 μM stimulated the release of [(3)H]d- aspartate, used to label the releasing pools of glutamate, both in control and SOD1/G93A mice. At variance, ≤0.3 μM 3,5-DHPG increased [(3)H]d-aspartate release in SOD1/G93A mice only. Experiments with selective antagonists indicated the involvement of both mGlu1 and mGlu5 receptors, mGlu5 being preferentially involved in the high potency effects of 3,5-DHPG. High 3,5-DHPG concentrations increased IP3 formation in both mouse strains, whereas low 3,5-DHPG did it in SOD1/G93A mice only. Release experiments confirmed that 3,5-DHPG elicited [(3)H]d-aspartate exocytosis involving intra-terminal Ca(2+) release through IP3-sensitive channels. Confocal microscopy indicated the co-existence of both receptors presynaptically in the same glutamatergic nerve terminal in SOD1/G93A mice. To conclude, activation of mGlu1/5 receptors produced abnormal glutamate release in SOD1/G93A mice, suggesting that these receptors are implicated in ALS and that selective antagonists may be predicted for new therapeutic approaches. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Francesco Giribaldi
- Department of Experimental Medicine Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
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Berger J, Dumont A, Focant M, Vergouts M, Sternotte A, Calas AG, Goursaud S, Hermans E. Opposite regulation of metabotropic glutamate receptor 3 and metabotropic glutamate receptor 5 by inflammatory stimuli in cultured microglia and astrocytes. Neuroscience 2012; 205:29-38. [DOI: 10.1016/j.neuroscience.2011.12.044] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 12/13/2011] [Accepted: 12/23/2011] [Indexed: 01/09/2023]
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Metabotropic glutamate receptors in neurodegeneration/neuroprotection: still a hot topic? Neurochem Int 2012; 61:559-65. [PMID: 22306345 DOI: 10.1016/j.neuint.2012.01.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 01/14/2012] [Accepted: 01/14/2012] [Indexed: 01/17/2023]
Abstract
Moving from early studies, we here review the most recent evidence linking metabotropic glutamate (mGlu) receptors to processes of neurodegeneration/neuroprotection. The use of knockout mice and subtype-selective drugs has increased our knowledge of the precise role played by individual mGlu receptor subtypes in these processes. Activation of mGlu1 and mGlu5 receptors may either amplify or reduce neuronal damage depending on the context and the nature of the toxic insults. In contrast, mGlu1 and mGlu5 receptors antagonists are consistently protective in in vitro and in vivo models of neuronal death. A series of studies suggest that mGlu1 receptor antagonists or negative allosteric modulators (NAMs) are promising candidates for the treatment of ischemic brain damage, whereas mGlu5 receptor NAMs, which have been clinically developed for the treatment of Parkinson's disease (PD) and l-DOPA-induced dyskinesias, protect nigro-striatal dopaminergic neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in mice and monkeys. Activation of glial mGlu3 receptors promotes the formation of various neurotrophic factors, such as transforming growth factor-β (TGF-β), glial-derived neurotrophic factor (GDNF), nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF). Hence, selective mGlu3 receptor agonists or positive allosteric modulators (PAMs) (not yet available) are potentially helpful in the treatment of chronic neurodegenerative disorders such as PD, Alzheimer's disease (AD), and amyotrophic lateral sclerosis. Selective mGlu2 receptor PAMs should be used with caution in AD patients because these drugs are shown to amplify β-amyloid neurotoxicity. Finally, mGlu4 receptor agonists/PAMs share with mGlu5 receptor NAMs the ability to improve motor symptoms associated with PD and attenuate nigro-striatal degeneration at the same time. No data are yet available on the role of mGlu7 and mGlu8 receptors in neurodegeneration/neuroprotection.
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