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Sun Y, Feng X, Ding Y, Li M, Yao J, Wang L, Gao Z. Phased Treatment Strategies for Cerebral Ischemia Based on Glutamate Receptors. Front Cell Neurosci 2019; 13:168. [PMID: 31105534 PMCID: PMC6499003 DOI: 10.3389/fncel.2019.00168] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 04/08/2019] [Indexed: 11/23/2022] Open
Abstract
Extracellular glutamate accumulation following cerebral ischemia leads to overactivation of glutamate receptors, thereby resulting in intracellular Ca2+ overload and excitotoxic neuronal injury. Multiple attempts have been made to counteract such effects by reducing glutamate receptor function, but none have been successful. In this minireview, we present the available evidence regarding the role of all types of ionotropic and metabotropic glutamate receptors in cerebral ischemia and propose phased treatment strategies based on glutamate receptors in both the acute and post-acute phases of cerebral ischemia, which may help realize the clinical application of glutamate receptor antagonists.
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Affiliation(s)
- Yongjun Sun
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, China.,Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, China
| | - Xue Feng
- Hebei University of Science and Technology, Shijiazhuang, China
| | - Yue Ding
- Shijiazhuang Vocational College of Technology and Information, Shijiazhuang, China
| | - Mengting Li
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, China
| | - Jun Yao
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, China
| | - Long Wang
- Department of Family and Consumer Sciences, California State University, Long Beach, CA, United States
| | - Zibin Gao
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, China.,State Key Laboratory Breeding Base-Hebei Province Key Laboratory of Molecular Chemistry for Drug, Shijiazhuang, China
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Lee Y, Khan A, Hong S, Jee SH, Park YH. A metabolomic study on high-risk stroke patients determines low levels of serum lysine metabolites: a retrospective cohort study. MOLECULAR BIOSYSTEMS 2017; 13:1109-1120. [DOI: 10.1039/c6mb00732e] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Metabolic alteration at early neurological deterioration during cerebral ischemia.
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Affiliation(s)
- Yeseung Lee
- Metabolomics Laboratory
- College of Pharmacy
- Korea University
- Sejong City
- Korea
| | - Adnan Khan
- Metabolomics Laboratory
- College of Pharmacy
- Korea University
- Sejong City
- Korea
| | - Seri Hong
- Department of Epidemiology and Health Promotion and Institute of Health Promotion
- Graduate School of Public Health
- Yonsei University
- Seoul
- Korea
| | - Sun Ha Jee
- Department of Epidemiology and Health Promotion and Institute of Health Promotion
- Graduate School of Public Health
- Yonsei University
- Seoul
- Korea
| | - Youngja H. Park
- Metabolomics Laboratory
- College of Pharmacy
- Korea University
- Sejong City
- Korea
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Massie A, Boillée S, Hewett S, Knackstedt L, Lewerenz J. Main path and byways: non-vesicular glutamate release by system xc(-) as an important modifier of glutamatergic neurotransmission. J Neurochem 2015; 135:1062-79. [PMID: 26336934 DOI: 10.1111/jnc.13348] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/24/2015] [Accepted: 08/25/2015] [Indexed: 12/14/2022]
Abstract
System xc(-) is a cystine/glutamate antiporter that exchanges extracellular cystine for intracellular glutamate. Cystine is intracellularly reduced to cysteine, a building block of GSH. As such, system xc(-) can regulate the antioxidant capacity of cells. Moreover, in several brain regions, system xc(-) is the major source of extracellular glutamate. As such this antiporter is able to fulfill key physiological functions in the CNS, while evidence indicates it also plays a role in certain brain pathologies. Since the transcription of xCT, the specific subunit of system xc(-), is enhanced by the presence of reactive oxygen species and inflammatory cytokines, system xc(-) could be involved in toxic extracellular glutamate release in neurological disorders that are associated with increased oxidative stress and neuroinflammation. System xc(-) has also been reported to contribute to the invasiveness of brain tumors and, as a source of extracellular glutamate, could participate in the induction of peritumoral seizures. Two independent reviews (Pharmacol. Rev. 64, 2012, 780; Antioxid. Redox Signal. 18, 2013, 522), approached from a different perspective, have recently been published on the functions of system xc(-) in the CNS. In this review, we highlight novel achievements and insights covering the regulation of system xc(-) as well as its involvement in emotional behavior, cognition, addiction, neurological disorders and glioblastomas, acquired in the past few years. System xc(-) constitutes an important source of extrasynaptic glutamate in the brain. By modulating the tone of extrasynaptic metabotropic or ionotropic glutamate receptors, it affects excitatory neurotransmission, the threshold for overexcitation and excitotoxicity and, as a consequence, behavior. This review describes the current knowledge of how system xc(-) is regulated and involved in physiological as well as pathophysiological brain functioning.
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Affiliation(s)
- Ann Massie
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Séverine Boillée
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Sandra Hewett
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York, USA
| | - Lori Knackstedt
- Psychology Department, University of Florida, Gainesville, Florida, USA
| | - Jan Lewerenz
- Department of Neurology, Ulm University, Oberer Eselsberg 45, Ulm, Germany
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Inhibition of the group I mGluRs reduces acute brain damage and improves long-term histological outcomes after photothrombosis-induced ischaemia. ASN Neuro 2013; 5:195-207. [PMID: 23772679 PMCID: PMC3786425 DOI: 10.1042/an20130002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Group I mGluRs (metabotropic glutamate receptors), including mGluR1 and mGluR5, are GPCRs (G-protein coupled receptors) and play important roles in physiology and pathology. Studies on their role in cerebral ischaemia have provided controversial results. In this study, we used a PT (photothrombosis)-induced ischaemia model to investigate whether antagonists to the group I mGluRs may offer acute and long-term protective effects in adult mice. Our results demonstrated that administration with mGluR5 antagonist MPEP [2-methyl-6-(phenylethynyl)-pyridine] or mGluR1 antagonist LY367385 by intraperitoneal injection at 3 h after PT decreased brain infarct volume evaluated one day after ischaemia. Additive effects on infarct volume were observed upon co-injection with MPEP and LY367385. These antagonists also significantly alleviated neurodegeneration and apoptosis in the penumbra. In addition, when evaluated 2 weeks after PT, they reduced infarct volume and tissue loss, attenuated glial scar formation, and inhibited cell proliferation in the penumbra. Importantly, co-injection with MPEP and LY367385 reduced the expression levels of calpain, a Ca2+-activated protease known to mediate ischaemia-induced neuronal death. Injection of calpeptin, a calpain inhibitor, could inhibit neuronal death and brain damage after PT but injection of calpeptin together with MPEP and LY367385 did not further improve the protective effects mediated by MPEP and LY367385. These results suggest that inhibition of group I mGluRs is sufficient to protect ischaemic damage through the calpain pathway. Taken together, our results demonstrate that inhibition of group I mGluRs can mitigate PT-induced brain damage through attenuating the effects of calpain, and improve long-term histological outcomes.
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Lewerenz J, Hewett SJ, Huang Y, Lambros M, Gout PW, Kalivas PW, Massie A, Smolders I, Methner A, Pergande M, Smith SB, Ganapathy V, Maher P. The cystine/glutamate antiporter system x(c)(-) in health and disease: from molecular mechanisms to novel therapeutic opportunities. Antioxid Redox Signal 2013; 18:522-55. [PMID: 22667998 PMCID: PMC3545354 DOI: 10.1089/ars.2011.4391] [Citation(s) in RCA: 624] [Impact Index Per Article: 56.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The antiporter system x(c)(-) imports the amino acid cystine, the oxidized form of cysteine, into cells with a 1:1 counter-transport of glutamate. It is composed of a light chain, xCT, and a heavy chain, 4F2 heavy chain (4F2hc), and, thus, belongs to the family of heterodimeric amino acid transporters. Cysteine is the rate-limiting substrate for the important antioxidant glutathione (GSH) and, along with cystine, it also forms a key redox couple on its own. Glutamate is a major neurotransmitter in the central nervous system (CNS). By phylogenetic analysis, we show that system x(c)(-) is a rather evolutionarily new amino acid transport system. In addition, we summarize the current knowledge regarding the molecular mechanisms that regulate system x(c)(-), including the transcriptional regulation of the xCT light chain, posttranscriptional mechanisms, and pharmacological inhibitors of system x(c)(-). Moreover, the roles of system x(c)(-) in regulating GSH levels, the redox state of the extracellular cystine/cysteine redox couple, and extracellular glutamate levels are discussed. In vitro, glutamate-mediated system x(c)(-) inhibition leads to neuronal cell death, a paradigm called oxidative glutamate toxicity, which has successfully been used to identify neuroprotective compounds. In vivo, xCT has a rather restricted expression pattern with the highest levels in the CNS and parts of the immune system. System x(c)(-) is also present in the eye. Moreover, an elevated expression of xCT has been reported in cancer. We highlight the diverse roles of system x(c)(-) in the regulation of the immune response, in various aspects of cancer and in the eye and the CNS.
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Affiliation(s)
- Jan Lewerenz
- Department of Neurology, University of Ulm, Ulm, Germany.
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Jackman NA, Melchior SE, Hewett JA, Hewett SJ. Non-cell autonomous influence of the astrocyte system xc- on hypoglycaemic neuronal cell death. ASN Neuro 2012; 4:e00074. [PMID: 22220511 PMCID: PMC3275339 DOI: 10.1042/an20110030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 01/03/2012] [Accepted: 01/05/2012] [Indexed: 01/13/2023] Open
Abstract
Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation) is initiated by glutamate extruded from astrocytes via system xc---an amino acid transporter that imports L-cystine and exports L-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents--whereas addition of L-cystine restores--GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc-. Indeed, drugs known to inhibit system xc- ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type) mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11) that encodes the substrate-specific light chain of system xc- (xCT). Finally, enhancement of astrocytic system xc- expression and function via IL-1β (interleukin-1β) exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of l-cystine and/or addition of system xc- inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc-, have a direct, non-cell autonomous effect on cortical neuron survival.
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Key Words
- aglycaemia
- astrocyte
- cystine
- glutamate
- neuronal death
- non-cell autonomous
- arac, β-d-cytosine arabinofuranoside
- bss, balanced salt solution
- cns, central nervous system
- cpg, carboxyphenylglycine
- gd, glucose deprivation
- il-1β, interleukin-1β
- ldh, lactate dehydrogenase
- mcao, middle cerebral artery occlusion
- nmda, n-methyl-d-aspartate
- qpcr, quantitative pcr
- wt, wild-type
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Affiliation(s)
- Nicole A Jackman
- *Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, U.S.A
| | - Shannon E Melchior
- *Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, U.S.A
| | - James A Hewett
- †Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY 13244, U.S.A
| | - Sandra J Hewett
- †Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY 13244, U.S.A
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Ribeiro FM, Pires RGW, Ferguson SSG. Huntington's disease and Group I metabotropic glutamate receptors. Mol Neurobiol 2010; 43:1-11. [PMID: 21153060 DOI: 10.1007/s12035-010-8153-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/15/2010] [Indexed: 12/21/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by involuntary body movement, cognitive impairment and psychiatric disturbance. A polyglutamine expansion in the amino-terminal region of the huntingtin (htt) protein is the genetic cause of HD. Htt protein interacts with a wide variety of proteins, and htt mutation causes cell signaling alterations in various neurotransmitter systems, including dopaminergic, glutamatergic, and cannabinoid systems, as well as trophic factor systems. This review will overview recent findings concerning htt-promoted alterations in cell signaling that involve different neurotransmitters and trophic factor systems, especially involving mGluR1/5, as glutamate plays a crucial role in neuronal cell death. The neuronal cell death that takes place in the striatum and cortex of HD patients is the most important factor underlying HD progression. Metabotropic glutamate receptors (mGluR1 and mGluR5) have a very controversial role in neuronal cell death and it is not clear whether mGluR1/5 activation either protects or exacerbates neuronal death. Thus, understanding how mutant htt protein affects glutamatergic receptor signaling will be essential to further establish a role for glutamate receptors in HD and develop therapeutic strategies to treat HD.
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Affiliation(s)
- Fabiola M Ribeiro
- Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Fogal B, Hewett SJ. Interleukin-1beta: a bridge between inflammation and excitotoxicity? J Neurochem 2008; 106:1-23. [PMID: 18315560 DOI: 10.1111/j.1471-4159.2008.05315.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Interleukin-1 (IL-1) is a proinflammatory cytokine released by many cell types that acts in both an autocrine and/or paracrine fashion. While IL-1 is best described as an important mediator of the peripheral immune response during infection and inflammation, increasing evidence implicates IL-1 signaling in the pathogenesis of several neurological disorders. The biochemical pathway(s) by which this cytokine contributes to brain injury remain(s) largely unidentified. Herein, we review the evidence that demonstrates the contribution of IL-1beta to the pathogenesis of both acute and chronic neurological disorders. Further, we highlight data that leads us to propose IL-1beta as the missing mechanistic link between a potential beneficial inflammatory response and detrimental glutamate excitotoxicity.
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Affiliation(s)
- Birgit Fogal
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
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Fogal B, Li J, Lobner D, McCullough LD, Hewett SJ. System x(c)- activity and astrocytes are necessary for interleukin-1 beta-mediated hypoxic neuronal injury. J Neurosci 2007; 27:10094-105. [PMID: 17881516 PMCID: PMC6672668 DOI: 10.1523/jneurosci.2459-07.2007] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The purpose of this study was to elucidate the cellular/biochemical pathway(s) by which interleukin-1beta (IL-1beta) contributes to the pathogenesis of hypoxic-ischemic brain damage. In vivo, IL-1 receptor type I (IL-1RI)-deficient mice showed smaller infarcts and less neurological deficits than wild-type animals after a 90 min reversible middle cerebral artery occlusion. In vitro, IL-1beta mediated an enhancement of hypoxic neuronal injury in murine cortical cultures that was lacking in cultures derived from IL-1RI null mutant animals and was blocked by the IL-1 receptor antagonist or an IL-1RI blocking antibody. This IL-1beta-mediated potentiation of hypoxic neuronal injury was associated with an increase in both cellular cystine uptake ([cystine]i) and extracellular glutamate levels ([glutamate]e) and was prevented by either ionotropic glutamate receptor antagonism or removal of L-cystine, suggesting a role for the cystine/glutamate antiporter (System x(c)-). Indeed, dual System x(c)-/metabotropic glutamate receptor subunit 1 (mGluR1) antagonism but not selective mGluR1 antagonism prevented neuronal injury. Additionally, cultures derived from mGluR1-deficient mice exhibited the same potentiation in injury after treatment with IL-1beta as wild-type cultures, an effect prevented by System x(c)-/mGluR1 antagonism. Finally, assessment of System x(c)- function and kinetics in IL-1beta-treated cultures revealed an increase in velocity of cystine transport (Vmax), in the absence of a change in affinity (Km). Neither the enhancement in [cystine]i, [glutamate]e, or neuronal injury were observed in chimeric cultures consisting of IL-1RI(+/+) neurons plated on top of IL-1RI(-/-) astrocytes, highlighting the importance of astrocyte-mediated alterations in System x(c)- as a novel contributor to the development and progression of hypoxic neuronal injury.
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Affiliation(s)
| | - Jun Li
- Neurology, University of Connecticut Health Center, Farmington, Connecticut 06030, and
| | - Doug Lobner
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Louise D. McCullough
- Neurology, University of Connecticut Health Center, Farmington, Connecticut 06030, and
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Ai J, Baker A. Presynaptic Excitability as a Potential Target for the Treatment of the Traumatic Cerebellum. Pharmacology 2004; 71:192-8. [PMID: 15240995 DOI: 10.1159/000078085] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2003] [Accepted: 12/17/2003] [Indexed: 11/19/2022]
Abstract
Using an extracellular recording method, we have previously shown a hyperexcitability of the presynaptic response in fluid percussion injury (FPI) in rats. In this study, we demonstrated that treatment with cis-ACBD, a glutamate reuptake inhibitor, depressed the presynaptic potential (PSP) in naive/sham controls, while it potentiated the PSP in FPI rats. On the contrary, (RS)-APICA, a selective group II metabotropic glutamate receptor antagonist, potentiated PSP in controls, but depressed PSP in FPI rats. These results indicate that an alteration of the normal function of metabotropic glutamate receptors and glutamate reuptake system or an altered reactivity of presynaptic fibers was induced by FPI. This alteration may contribute to the reported loss of Purkinje cells after FPI. PSP may be used as a potential tool for evaluating treatments of FPI or as a potential target for the prevention of Purkinje cell death.
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Affiliation(s)
- Jinglu Ai
- Traumatic Brain Injury Laboratory, Cara Phelan Centre for Trauma Research, St. Michael's Hospital, University of Toronto, Toronto, Ont., Canada.
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11
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Shi Q, Savage JE, Hufeisen SJ, Rauser L, Grajkowska E, Ernsberger P, Wroblewski JT, Nadeau JH, Roth BL. L-homocysteine sulfinic acid and other acidic homocysteine derivatives are potent and selective metabotropic glutamate receptor agonists. J Pharmacol Exp Ther 2003; 305:131-42. [PMID: 12649361 DOI: 10.1124/jpet.102.047092] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Moderate hyperhomocysteinemia is associated with several diseases, including coronary artery disease, stroke, Alzheimer's disease, schizophrenia, and spina bifida. However, the mechanisms for their pathogenesis are unknown but could involve the interaction of homocysteine or its metabolites with molecular targets such as neurotransmitter receptors, channels, or transporters. We discovered that L-homocysteine sulfinic acid (L-HCSA), L-homocysteic acid, L-cysteine sulfinic acid, and L-cysteic acid are potent and effective agonists at several rat metabotropic glutamate receptors (mGluRs). These acidic homocysteine derivatives 1) stimulated phosphoinositide hydrolysis in the cells stably expressing the mGluR1, mGluR5, or mGluR8 (plus Galpha(qi9)) and 2) inhibited the forskolin-induced cAMP accumulation in the cells stably expressing mGluR2, mGluR4, or mGluR6, with different potencies and efficacies depending on receptor subtypes. Of the four compounds, L-HCSA is the most potent agonist at mGluR1, mGluR2, mGluR4, mGluR5, mGluR6, and mGluR8. The effects of the four agonists were selective for mGluRs because activity was not discovered when L-HCSA and several other homocysteine derivatives were screened against a large panel of cloned neurotransmitter receptors, channels, and transporters. These findings imply that mGluRs are candidate G-protein-coupled receptors for mediating the intracellular signaling events induced by acidic homocysteine derivatives. The relevance of these findings for the role of mGluRs in the pathogenesis of homocysteine-mediated phenomena is discussed.
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Affiliation(s)
- Qi Shi
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
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12
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Mills CD, Johnson KM, Hulsebosch CE. Group I metabotropic glutamate receptors in spinal cord injury: roles in neuroprotection and the development of chronic central pain. J Neurotrauma 2002; 19:23-42. [PMID: 11852976 DOI: 10.1089/089771502753460213] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Spinal cord injury (SCI) initiates a cascade of biochemical events that leads to an increase in extracellular excitatory amino acid (EAA) concentrations, which results in glutamate receptor-mediated excitotoxic events. An important division of these glutamate receptors is the metabotropic glutamate receptor (mGluR) class, which is divided into three groups. Of these three groups, group I (mGluR1 and mGluR5) activation can initiate a number of intracellular pathways that lead to increased extracellular EAA concentrations. To evaluate subtypes of group I mGluRs in SCI, we administered AIDA (group I antagonist), LY 367385 (mGluR1 specific antagonist), or MPEP (mGluR5 specific antagonist) by interspinal injection to adult male Sprague-Dawley rats (175-200 g) immediately following injury at T10 with an NYU impactor (12.5-mm drop, 10-g rod, 2 mm in diameter). AIDA- and LY 367385-treated subjects had improved locomotor scores and demonstrated an attenuation in the development of mechanical allodynia as measured by von Frey stimulation of the forelimbs; however, LY 367385 potentiated the development of thermal hyperalgesia. MPEP had no effect on locomotor recovery or mechanical allodynia, but attenuated the development of thermal hyperalgesia. AIDA and LY 367385 treatment resulted in a significant increase in tissue sparing compared to the vehicle-treated group at 4 weeks following SCI. These results suggest that mGluRs play an important role in EAA toxicity and have different acute pathophysiological roles following spinal cord injury.
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Affiliation(s)
- Charles D Mills
- Department of Anatomy and Neurosciences, University of Texas Medical Branch at Galveston, 77555-1043, USA
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13
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Costantino G, Macchiarulo A, Pellicciari R. Metabotropic glutamate receptors: targets for therapy of cerebral ischaemia. Expert Opin Ther Targets 2001; 5:669-683. [PMID: 12540277 DOI: 10.1517/14728222.5.6.669] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Several pathophysiological processes are involved in the progression of the cerebral ischaemic injury, among which are inflammation, peri-infarct depolarisation, apoptosis and excitotoxicity. Overactivation of glutamate receptors, both ionotropic and metabotropic, constitutes the central step in the excitotoxic cascade of events leading to neuronal cell death following acute brain ischaemia. Owing to their peculiar characteristics of modulatory receptors and due to their wide molecular and biological diversity, metabotropic glutamate receptors constitute an attractive target for the development of potential neuroprotective agents. Recent achievements in developing novel chemical entities and in the characterisation of the physiological and pathological role of individual metabotropic glutamate receptors in postischaemic degeneration will be reviewed.
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Affiliation(s)
- Gabriele Costantino
- Dipartimento di Chimica e Tecnologia del Farmaco,Università di Perugia,Via del Liceo, 1.06123- Perugia, Italy.
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14
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Martin LJ, Sieber FE, Traystman RJ. Apoptosis and necrosis occur in separate neuronal populations in hippocampus and cerebellum after ischemia and are associated with differential alterations in metabotropic glutamate receptor signaling pathways. J Cereb Blood Flow Metab 2000; 20:153-67. [PMID: 10616804 DOI: 10.1097/00004647-200001000-00020] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It was evaluated whether postischemic neurodegeneration is apoptosis and occurs with alterations in phosphoinositide-linked metabotropic glutamate receptors (mGluRs) and their associated signaling pathways. A dog model of transient global incomplete cerebral ischemia was used. The CA1 pyramidal cells and cerebellar Purkinje cells underwent progressive delayed degeneration. By in situ end-labeling of DNA, death of CA1 and Purkinje cells was greater at 7 days than 1 day after ischemia, whereas death of granule neurons in dentate gyrus and cerebellar cortex was greater at 1 than at 7 days. Ultrastructurally, degenerating CA1 pyramidal neurons and cerebellar Purkinje cells were necrotic; in contrast, degenerating granule neurons were apoptotic. In agarose gels of regional DNA extracts, random DNA fragmentation coexisted with internucleosomal fragmentation. By immunoblotting of regional homogenates, mGluR1alpha, mGluR5, phospholipase Cbeta (PLCbeta), and Galphaq/11 protein levels in hippocampus at 1 and 7 days after ischemia were similar to control levels, but in cerebellar cortex, mGluR1alpha and mGluR5 were decreased but PLCbeta was increased. By immunocytochemistry, mGluR and PLCbeta immunoreactivity dissipated in CA1 and cerebellar Purkinje cell/ molecular layers, whereas immunoreactivities for these proteins were enhanced in granule neurons. It was concluded that neuronal death after global ischemia exists as two distinct, temporally overlapping forms in hippocampus and cerebellum: necrosis of pyramidal neurons and Purkinje cells and apoptosis of granule neurons. Neuronal necrosis is associated with a loss of phosphoinositide-linked mGluR transduction proteins, whereas neuronal apoptosis occurs with increased mGluR signaling.
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Affiliation(s)
- L J Martin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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15
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Pellegrini-Giampietro DE, Cozzi A, Peruginelli F, Leonardi P, Meli E, Pellicciari R, Moroni F. 1-Aminoindan-1,5-dicarboxylic acid and (S)-(+)-2-(3'-carboxybicyclo[1.1.1] pentyl)-glycine, two mGlu1 receptor-preferring antagonists, reduce neuronal death in in vitro and in vivo models of cerebral ischaemia. Eur J Neurosci 1999; 11:3637-47. [PMID: 10564371 DOI: 10.1046/j.1460-9568.1999.00786.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Metabotropic glutamate (mGlu) receptors have been implicated in a number of physiological and pathological responses to glutamate, but the exact role of group I mGlu receptors in causing postischaemic injury is not yet clear. In this study, we examined whether the recently-characterized and relatively selective mGlu1 receptor antagonists 1-aminoindan-1,5-dicarboxylic acid (AIDA) and (S)-(+)-2-(3'-carboxybicyclo[1.1.1]pentyl)-glycine (CBPG) could reduce neuronal death in vitro, following oxygen-glucose deprivation (OGD) in murine cortical cell and rat organotypic hippocampal cultures, and in vivo, after global ischaemia in gerbils. When present in the incubation medium during the OGD insult and the subsequent 24 h recovery period, AIDA and CBPG significantly reduced neuronal death in vitro. The extent of protection was similar to that observed with the nonselective mGlu receptor antagonist (+)-alpha-methyl-4-carboxyphenylglycine [(+)MCPG] and with typical ionotropic glutamate (iGlu) receptor antagonists. Neuroprotection was also observed when AIDA or CBPG were added only after the OGD insult was terminated. Neuronal injury was not attenuated by the inactive isomer (-)MCPG, but was significantly enhanced by the nonselective mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1, 3-dicarboxylic acid [(1S,3R)-ACPD] and the group I mGlu receptor agonist 3,5-dihydroxyphenylglycine (3,5-DHPG). The antagonists (+)MCPG, AIDA and CBPG were also neuroprotective in vivo, because i. c.v. administration reduced CA1 pyramidal cell degeneration examined 7 days following transient carotid occlusion in gerbils. Our results point to a role of mGlu1 receptors in the pathological mechanisms responsible for postischaemic neuronal death and propose a new target for neuroprotection.
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Schwarzer C, Sperk G. Glutamate-stimulated neuropeptide Y mRNA expression in the rat dentate gyrus: a prominent role of metabotropic glutamate receptors. Hippocampus 1998; 8:274-88. [PMID: 9662141 DOI: 10.1002/(sici)1098-1063(1998)8:3<274::aid-hipo9>3.0.co;2-j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The influence of intrahippocampal injections of glutamate receptor agonists on neuropeptide Y (NPY) mRNA expression was investigated in granule cells and interneurons of the rat dentate gyrus. One day after local injection of non-neurodegenerative doses (20 and 70 nmol) of the metabotropic glutamate receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate [(1S,3R)ACPD], NPY mRNA levels were more than doubled in ipsilateral granule cells and interneurons. Doses of 200 and 400 nmol caused up to 15.9- and 4.6-fold mRNA increases in granule cells and interneurons, respectively. The group I metabotropic glutamate receptor agonist (RS)-3,5-dihydroxyphenylglycine (DHPG; 50 nmol), but not the group III receptor agonist L(+)-2-amino-4-phosphonobutyrate (L-AP4; 20 and 200 nmol) exerted a similar action. The general metabotropic glutamate receptor antagonist (+)-alpha-methyl-4-carboxyphenylglycine (MCPG; 200 nmol), the group I receptor antagonist (S)-4-carboxyphenylglycine (4-CPG; 200 nmol) and the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (1 mg/kg; i.p.) partially blocked the (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate-induced increase in NPY mRNA in granule cells, but not in interneurons. (S)-4-carboxyphenylglycine (200 nmol) by itself increased NPY mRNA levels in ipsilateral interneurons threefold, indicating the activation of phospholipase D coupled receptors. Non-neurodegenerative doses of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA, 0.3 nmol) caused modest increases in NPY mRNA levels in ipsilateral interneurons, whereas neurodegenerative doses (1-10 nmol) induced markedly increased NPY mRNA levels in granule cells (up to 11-fold) and interneurons (up to threefold). It is suggested that activation of metabotropic glutamate receptors stimulates NPY mRNA expression in granule cells and interneurons in the rat dentate gyrus. Whereas in granule cells NPY mRNA upregulation is preferentially mediated by group I metabotropic glutamate receptors, it may involve ionotropic and metabotropic glutamate receptors in interneurons.
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Affiliation(s)
- C Schwarzer
- Department of Pharmacology, University of Innsbruck, Austria.
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