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Zhang M, Zhi N, Feng J, Liu Y, Zhang M, Liu D, Yuan J, Dong Y, Jiang S, Ge J, Wu S, Zhao X. ITPR2 Mediated Calcium Homeostasis in Oligodendrocytes is Essential for Myelination and Involved in Depressive-Like Behavior in Adolescent Mice. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306498. [PMID: 38476116 PMCID: PMC11132048 DOI: 10.1002/advs.202306498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/15/2024] [Indexed: 03/14/2024]
Abstract
Ca2+ signaling is essential for oligodendrocyte (OL) development and myelin formation. Inositol 1,4,5-trisphosphate receptor type 2 (ITPR2) is an endoplasmic reticulum calcium channel and shows stage-dependent high levels in postmitotic oligodendrocyte precursor cells (OPCs). The role and potential mechanism of ITPR2 in OLs remain unclear. In this study, it is revealed that loss of Itpr2 in OLs disturbs Ca2+ homeostasis and inhibits myelination in adolescent mice. Animals with OL-specific deletion of Itpr2 exhibit anxiety/depressive-like behaviors and manifest with interrupted OPC proliferation, leading to fewer mature OLs in the brain. Detailed transcriptome profiling and signal pathway analysis suggest that MAPK/ERK-CDK6/cyclin D1 axis underlies the interfered cell cycle progression in Itpr2 ablated OPCs. Besides, blocking MAPK/ERK pathway significantly improves the delayed OPC differentiation and myelination in Itpr2 mutant. Notably, the resting [Ca2+]i is increased in Itpr2 ablated OPCs, with the elevation of several plasma calcium channels. Antagonists against these plasma calcium channels can normalize the resting [Ca2+]i level and enhance lineage progression in Itpr2-ablated OPCs. Together, the findings reveal novel insights for calcium homeostasis in manipulating developmental transition from OPCs to pre-OLs; additionally, the involvement of OLs-originated ITPR2 in depressive behaviors provides new therapeutic strategies to alleviate myelin-associated psychiatric disorders.
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Affiliation(s)
- Ming Zhang
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Na Zhi
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
- College of Life SciencesNorthwest UniversityXi'an710127P. R. China
| | - Jiaxiang Feng
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Yingqi Liu
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Meixia Zhang
- School of Life Science and TechnologyXi'an Jiaotong UniversityXi'an710049P. R. China
| | - Dingxi Liu
- First Affiliated Hospital of Medical CollegeXi'an Jiaotong UniversityXi'an710061P. R. China
| | - Jie Yuan
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
- College of Life SciencesNorthwest UniversityXi'an710127P. R. China
| | - Yuhao Dong
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Sufang Jiang
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Junye Ge
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Shengxi Wu
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
| | - Xianghui Zhao
- Department of NeuroscienceAir Force Medical UniversityXi'an710032P. R. China
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2
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Hámor PU, Knackstedt LA, Schwendt M. The role of metabotropic glutamate receptors in neurobehavioral effects associated with methamphetamine use. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 168:177-219. [PMID: 36868629 DOI: 10.1016/bs.irn.2022.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are expressed throughout the central nervous system and act as important regulators of drug-induced neuroplasticity and behavior. Preclinical research suggests that mGlu receptors play a critical role in a spectrum of neural and behavioral consequences arising from methamphetamine (meth) exposure. However, an overview of mGlu-dependent mechanisms linked to neurochemical, synaptic, and behavioral changes produced by meth has been lacking. This chapter provides a comprehensive review of the role of mGlu receptor subtypes (mGlu1-8) in meth-induced neural effects, such as neurotoxicity, as well as meth-associated behaviors, such as psychomotor activation, reward, reinforcement, and meth-seeking. Additionally, evidence linking altered mGlu receptor function to post-meth learning and cognitive deficits is critically evaluated. The chapter also considers the role of receptor-receptor interactions involving mGlu receptors and other neurotransmitter receptors in meth-induced neural and behavioral changes. Taken together, the literature indicates that mGlu5 regulates the neurotoxic effects of meth by attenuating hyperthermia and possibly through altering meth-induced phosphorylation of the dopamine transporter. A cohesive body of work also shows that mGlu5 antagonism (and mGlu2/3 agonism) reduce meth-seeking, though some mGlu5-blocking drugs also attenuate food-seeking. Further, evidence suggests that mGlu5 plays an important role in extinction of meth-seeking behavior. In the context of a history of meth intake, mGlu5 also co-regulates aspects of episodic memory, with mGlu5 stimulation restoring impaired memory. Based on these findings, we propose several avenues for the development of novel pharmacotherapies for Methamphetamine Use Disorder based on the selective modulation mGlu receptor subtype activity.
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Affiliation(s)
- Peter U Hámor
- Department of Psychology, University of Florida, Gainesville, FL, United States; Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States; Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Lori A Knackstedt
- Department of Psychology, University of Florida, Gainesville, FL, United States; Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States
| | - Marek Schwendt
- Department of Psychology, University of Florida, Gainesville, FL, United States; Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States.
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3
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STIM1, STIM2, and PDI Participate in Cellular Fate Decisions in Low Energy Availability Induced by 3-NP in Male Rats. Neurotox Res 2021; 39:1459-1469. [PMID: 34173958 DOI: 10.1007/s12640-021-00388-0] [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: 05/14/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 10/21/2022]
Abstract
Impairment in the energetic function of mitochondria is seen in many neurologic disorders like neurodegeneration. It disrupts ATP production, gives rise to oxidative stress, and ultimately challenges the viability of neurons. In this situation, neural cells use complex crosstalk between various subcellular elements to make live-or-die decisions about their fate. This study aimed to describe a part of the molecular changes and the outcome of the cellular decision during an energy crisis in neural cells in a time-dependent manner in the striatum. Adult male rats were treated with single or multiple 3-nitropropionic acid (3-NP) doses, a mitochondrial toxin, for 1 to 5 days. We found that protein disulfide isomerase (PDI) activity was decreased on the third day and remained lower than the control group up to the fifth day. However, on the day 1 and day 2 of 3-NP treatment, the stromal interaction molecule (STIM) 1 and STIM2 significantly decreased. On the third day, STIM1 and STIM2 were increased and reached the level of controls and remained the same up to the fifth day. In this condition, cell death was significantly higher than the controls from the third day up to the fifth day. We also showed that even a single dose of 3-NP reduced the brain volume. These data suggest that the STIM1, STIM2, and PDI activity changes may be involved in the outcome of cellular fate decisions. It also suggests that cells may reduce STIM1 and STIM2 as a defense mechanism against low energy availability.
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Su LD, Wang N, Han J, Shen Y. Group 1 Metabotropic Glutamate Receptors in Neurological and Psychiatric Diseases: Mechanisms and Prospective. Neuroscientist 2021; 28:453-468. [PMID: 34088252 PMCID: PMC9449437 DOI: 10.1177/10738584211021018] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors
that are activated by glutamate in the central nervous system (CNS).
Basically, mGluRs contribute to fine-tuning of synaptic efficacy and
control the accuracy and sharpness of neurotransmission. Among eight
subtypes, mGluR1 and mGluR5 belong to group 1 (Gp1) family, and are
implicated in multiple CNS disorders, such as Alzheimer’s disease,
autism, Parkinson’s disease, and so on. In the present review, we
systematically discussed underlying mechanisms and prospective of Gp1
mGluRs in a group of neurological and psychiatric diseases, including
Alzheimer’s disease, Parkinson’s disease, autism spectrum disorder,
epilepsy, Huntington’s disease, intellectual disability, Down’s
syndrome, Rett syndrome, attention-deficit hyperactivity disorder,
addiction, anxiety, nociception, schizophrenia, and depression, in
order to provide more insights into the therapeutic potential of Gp1
mGluRs.
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Affiliation(s)
- Li-Da Su
- Neuroscience Care Unit, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Na Wang
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Junhai Han
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Ying Shen
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, China
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5
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Huang G, Thompson SL, Taylor JR. MPEP Lowers Binge Drinking in Male and Female C57BL/6 Mice: Relationship with mGlu5/Homer2/Erk2 Signaling. Alcohol Clin Exp Res 2021; 45:732-742. [PMID: 33587295 PMCID: PMC8076072 DOI: 10.1111/acer.14576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/10/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Metabotropic glutamate receptor 5 (mGlu5) plays an important role in excessive alcohol use and the mGlu5/Homer2/Erk2 signaling pathway has been implicated in binge drinking. The mGlu5 negative allosteric modulator (NAM) 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP) has been shown to reduce binge drinking in male mice, but less is known about its effect on female mice. Here, we sought to determine whether sex differences exists in the effects of MPEP on binge drinking and whether they relate to changes in the MPEP mGlu5/Homer2/Erk2 signaling. METHODS We measured the dose-response effect of MPEP on alcohol consumption in male and female mice using the Drinking in the Dark (DID) paradigm to assess potential sex differences. To rule out possible confounds of MPEP on locomotion, we measured the effects of MPEP on locomotor activity and drinking simultaneously during DID. Lastly, to test whether MPEP-induced changes in alcohol consumption were related to changes in Homer2 or Erk2 expression, we performed qPCR using brain tissue acquired from mice that had undergone 7 days of DID. RESULTS 30 mg/kg MPEP reduced binge alcohol consumption across female and male mice, with no sex differences in the dose-response relationship. Locomotor activity did not mediate the effects of MPEP on alcohol intake, but activity correlated with alcohol intake independent of MPEP. MPEP did not change the expression of Homer2 and Erk2 mRNA in the bed nucleus of the stria terminalis (BNST) or nucleus accumbens in mice whose drinking was reduced by MPEP, relative to saline. There was a positive relationship between alcohol intake and Homer2 expression in the BNST. CONCLUSIONS MPEP reduced alcohol consumption during DID in male and female C57BL/6 mice but did not change Homer2/Erk2 expression. Locomotor activity did not mediate the effects of MPEP on alcohol intake, though it correlated with alcohol intake. Alcohol intake during DID predicted BNST Homer2 expression. These data provide support for the regulation of alcohol consumption by mGlu5 across sexes.
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Affiliation(s)
- Gan Huang
- Department of Psychiatry, Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Summer L. Thompson
- Department of Psychiatry, Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Jane R. Taylor
- Department of Psychiatry, Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychology, Yale University Graduate School of Arts and Sciences, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
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6
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Khodagholi F, Maleki A, Motamedi F, Mousavi MA, Rafiei S, Moslemi M. Oxytocin Prevents the Development of 3-NP-Induced Anxiety and Depression in Male and Female Rats: Possible Interaction of OXTR and mGluR2. Cell Mol Neurobiol 2020; 42:1105-1123. [PMID: 33201416 DOI: 10.1007/s10571-020-01003-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/07/2020] [Indexed: 01/01/2023]
Abstract
Huntington disease (HD) is a progressive neurological disorder with dominant motor symptoms. It also has psychiatric manifestations, like anxiety and depression, that can emerge themselves before motor symptoms and impose a major burden on patients. Oxytocin (OXT) is a newly emerged treatment for disorders like autism and schizophrenia and recently is using to alleviate depression and anxiety. In the current study, we investigated the behavioral and molecular effects of OXT on the development of anxiety and depression in 3-nitropropionic acid (3-NP)-induced model of HD. Anxiety- and depression-like behaviors as well as the levels of oxytocin receptor (OXTR), metabotropic glutamate receptor (mGluR) 2, mGluR5, and glutathione (GSH) were measured in striatum, hippocampus, prefrontal cortex, and amygdala. Also, we questioned if sex had any modulatory effect. We found that 3-NP increased anxiety and depression compared to controls. It also reduced the levels of OXTR and mGluR2, increased mGluR5, and reduced GSH in studied brain regions. Pretreatment with OXT before the injection of 3-NP ameliorated anxiety and depression. Additionally, it protected the brain from developing low levels of OXTR, mGluR2, and GSH and high levels of mGluR5 in studied regions. The protective effects of OXT were similar between male and female animals. These data suggest that OXTR, mGluR2, mGluR5, and GSH may contribute to psychiatric manifestations of HD. In addition, pretreatment with OXT could prevent the mood changes in male and female rats.
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Affiliation(s)
- Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Maleki
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereshteh Motamedi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Alsadat Mousavi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahrbanoo Rafiei
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Moslemi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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7
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Simões-Pires EN, Ferreira ST, Linden R. Roles of glutamate receptors in a novel in vitro model of early, comorbid cerebrovascular, and Alzheimer's diseases. J Neurochem 2020; 156:539-552. [PMID: 32683713 DOI: 10.1111/jnc.15129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 11/28/2022]
Abstract
Systemic multimorbidity is highly prevalent in the elderly and, remarkably, coexisting neuropathological markers of Alzheimer's (AD) and cerebrovascular (CVD) diseases are found at autopsy in most brains of patients clinically diagnosed as AD. Little is known on neurodegeneration peculiar to comorbidities, especially at early stages when pathogenesis may propagate at subclinical levels. We developed a novel in vitro model of comorbid CVD/AD in organotypic hippocampal cultures, by combining oxygen-glucose deprivation (OGD) and exposure to amyloid-Aβ oligomers (AβOs), both applied at levels subtoxic to neurons when used in isolation. We focused on synaptic proteins and the roles of glutamate receptors, which have been implicated in many basic and clinical approaches to either CVD or AD. Subtoxic insults by OGD and AβOs synergized to reduce levels of synaptophysin (SYP) and PSD-95 without cell death, while effects of antagonists of either metabotropic or ionotropic glutamate receptors were distinct from reports in models of isolated CVD or AD. In particular, modulation of glutamate receptors differentially impacted SYP and PSD-95, and antagonists of a single receptor subtype had distinct effects when either isolated or combined. Our findings highlight the complexity of CVD/AD comorbidity, help understand variable responses to glutamate receptor antagonists in patients diagnosed with AD and may contribute to future development of therapeutics based on investigation of the pattern of progressive comorbidity.
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Affiliation(s)
| | - Sergio T Ferreira
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto de Bioquímica Médica Leopoldo de Meis, UFRJ, Rio de Janeiro, Brazil
| | - Rafael Linden
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil
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8
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Rahman MS, Yang J, Luan Y, Qiu Z, Zhang J, Lu H, Chen X, Liu Y. Attenuation of Acute Intracerebral Hemorrhage-Induced Microglial Activation and Neuronal Death Mediated by the Blockade of Metabotropic Glutamate Receptor 5 In Vivo. Neurochem Res 2020; 45:1230-1243. [PMID: 32140955 DOI: 10.1007/s11064-020-03006-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/21/2020] [Accepted: 02/29/2020] [Indexed: 12/12/2022]
Abstract
The activation of microglia in response to intracerebral hemorrhagic stroke is one of the principal components of the progression of this disease. It results in the formation of pro-inflammatory cytokines that lead to neuronal death, a structural deterioration that, in turn interferes with functional recovery. Metabotropic glutamate receptor 5 (mGluR5) is highly expressed in reactive microglia and is involved in the pathological processes of brain disorders, but its role in intracerebral hemorrhage (ICH) remains unknown. We hypothesized that mGluR5 regulates microglial activation and ICH maintenance. In this study, collagenase-induced ICH mice received a single intraperitoneal injection of the mGluR5 antagonist-, MTEP, or vehicle 2 h after injury. We found that acute ICH upregulated mGluR5 and microglial activation. mGluR5 was highly localized in reactive microglia in the peri-hematomal cortex and striatum on days 3 and 7 post-ICH. The MTEP-mediated pharmacological inhibition of mGluR5 in vivo resulted in the substantial attenuation of acute microglial activation and IL-6, and TNF-α release. We also showed that the blockade of mGluR5 markedly reduced cell apoptosis, and neurodegeneration and markedly elevated neuroprotection. Furthermore, the MTEP-mediated inhibition of mGluR5 significantly reduced the lesion volume and improved functional recovery. Taken together, our results demonstrate that ICH injury enhances mGluR5 expression in the acute and subacute stages and that mGluR5 is highly localized in reactive microglia. The blockade of mGluR5 reduces ICH-induced acute microglial activation, provides neuroprotection and promotes neurofunctional recovery after ICH. The inhibition of mGluR5 may be a relevant therapeutic target for intracerebral hemorrhagic stroke.
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Affiliation(s)
- Md Saidur Rahman
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China.,Department of Anatomy and Histology, Patuakhali Science and Technology University, Dhaka, Bangladesh
| | - Jianbo Yang
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - Yan Luan
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China
| | - Zhengguo Qiu
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Medical University, Xi'an, 710038, Shaanxi, People's Republic of China
| | - Jianshui Zhang
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China
| | - Haixia Lu
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China
| | - Xinlin Chen
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China.
| | - Yong Liu
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an, 710061, Shaanxi, People's Republic of China.
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9
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Qi Z, Mi C, Wu F, Yang X, Sang Y, Liu Y, Li J, Yang H, Xu B, Liu W, Xu Z, Deng Y. The effect of manganese exposure on GnRH secretion via Nrf2/mGluR5/COX-2/PGE2/signaling pathway. Toxicol Ind Health 2020; 35:211-227. [PMID: 30862296 DOI: 10.1177/0748233719825720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There are limited studies focused on the precise mechanism of gonadotropin-releasing hormone (GnRH) secretion dysfunction after overexposure to manganese (Mn). The objective of the present study was to explore the mechanism of Mn disruption of GnRH synthesis via nuclear factor erythroid-2-related factor-2 (Nrf2)/metabotropic glutamate receptor-5 (mGluR5)/cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) signaling pathway in vitro and in vivo. Primary astrocytes were cultured and treated with different doses of Mn, tert-butylhydroquinonet (tBHQ; Nrf2 agonists), 3-[(2-methyl-4-thaizolyl) ethynyl] pyridine (MTEP; mGluR5 inhibitor), and celecoxib (COX-2 inhibitor) to measure the levels of COX-2, mGluR5, Nrf2, and Nrf2 target genes. Mice were randomly divided into 11 groups, of which included the control group, 12.5-, 25-, and 50-mg/kg MnCl2 group, dimethyl sulfoxide (DMSO) group, tBHQ control group, tBHQ pretreatment group, MTEP control group, MTEP pretreatment group, celecoxib control group, and celecoxib pretreatment group. The injection was administered every day for 2 weeks. Then, levels of GnRH, PGE2, COX-2, mGluR5, Nrf2, Nrf2 target genes, and morphological changes in the hypothalamus of mice were measured. Mn reduced protein levels of Nrf2 and mRNA expression of Nrf2 target genes and increased mGluR5, COX-2, PGE2, and GnRH levels. Meanwhile, injury-related histomorphology changes in the hypothalamus of mice were significantly present. In conclusion, excessive exposure to Mn disrupts GnRH secretion through Nrf2/mGluR5/COX-2/PGE2 signaling pathway.
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Affiliation(s)
- Zhipeng Qi
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Chao Mi
- 2 Department of School Health Supervision, Institute of Shenyang Health Inspection, Shenyang, People's Republic of China
| | - Fengdi Wu
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Xinxin Yang
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Yanqi Sang
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Yanan Liu
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Jiashuo Li
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Haibo Yang
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China.,3 Department of Occupational Diseases, Linyi People's Hospital, Shandong, People's Republic of China
| | - Bin Xu
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Wei Liu
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Zhaofa Xu
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
| | - Yu Deng
- 1 Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People's Republic of China
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10
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Metabotropic glutamate receptors and neurodegenerative diseases. Pharmacol Res 2017; 115:179-191. [DOI: 10.1016/j.phrs.2016.11.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/11/2016] [Accepted: 11/15/2016] [Indexed: 12/21/2022]
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11
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Sato K, Yamanaka Y, Asakura Y, Nedachi T. Glutamate levels control HT22 murine hippocampal cell death by regulating biphasic patterns of Erk1/2 activation: role of metabolic glutamate receptor 5. Biosci Biotechnol Biochem 2016; 80:712-8. [DOI: 10.1080/09168451.2015.1107466] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abstract
Extracellular glutamate concentration is a critical determinant of neuronal cell fate. We recently demonstrated that HT22 murine hippocampal cell viability was reduced by exposure to high concentrations of glutamate, whereas low concentrations promoted cell survival. Extracellular signal-regulated kinase (Erk)1/2 activation by glutamate is important for both glutamate-induced cell death and survival. In this study, we investigated the role of glutamate-induced or hydrogen peroxide (H2O2)-induced Erk1/2 activation in HT22 cell fate determination. Glutamate and H2O2 treatment similarly induced early (<1 h) Erk1/2 phosphorylation regardless of concentration. On the other hand, persistent Erk1/2 phosphorylation (16–24 h) was observed only in the presence of excess glutamate. Only the latter contributed to glutamate-induced cell death, which involved metabolic glutamate receptor 5. Our findings suggest that glutamate concentration modulates two distinct phases of Erk1/2 activation, which can explain the glutamate concentration-dependent determination of HT22 cell fate.
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Affiliation(s)
- Kazunori Sato
- Department of Life Sciences, Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | - Yuki Yamanaka
- Faculty of Life Sciences, Department of Applied Biosciences, Toyo University, Gunma, Japan
| | - Yasuharu Asakura
- Faculty of Life Sciences, Department of Applied Biosciences, Toyo University, Gunma, Japan
| | - Taku Nedachi
- Department of Life Sciences, Graduate School of Life Sciences, Toyo University, Gunma, Japan
- Faculty of Life Sciences, Department of Applied Biosciences, Toyo University, Gunma, Japan
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12
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Intracellular mGluR5 plays a critical role in neuropathic pain. Nat Commun 2016; 7:10604. [PMID: 26837579 PMCID: PMC4742982 DOI: 10.1038/ncomms10604] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 01/04/2016] [Indexed: 12/17/2022] Open
Abstract
Spinal mGluR5 is a key mediator of neuroplasticity underlying persistent pain. Although brain mGluR5 is localized on cell surface and intracellular membranes, neither the presence nor physiological role of spinal intracellular mGluR5 is established. Here we show that in spinal dorsal horn neurons >80% of mGluR5 is intracellular, of which ∼60% is located on nuclear membranes, where activation leads to sustained Ca(2+) responses. Nerve injury inducing nociceptive hypersensitivity also increases the expression of nuclear mGluR5 and receptor-mediated phosphorylated-ERK1/2, Arc/Arg3.1 and c-fos. Spinal blockade of intracellular mGluR5 reduces neuropathic pain behaviours and signalling molecules, whereas blockade of cell-surface mGluR5 has little effect. Decreasing intracellular glutamate via blocking EAAT-3, mimics the effects of intracellular mGluR5 antagonism. These findings show a direct link between an intracellular GPCR and behavioural expression in vivo. Blockade of intracellular mGluR5 represents a new strategy for the development of effective therapies for persistent pain.
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Metabotropic glutamate receptor 5 – a promising target in drug development and neuroimaging. Eur J Nucl Med Mol Imaging 2016; 43:1151-70. [DOI: 10.1007/s00259-015-3301-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
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Kouvaros S, Papatheodoropoulos C. Major dorsoventral differences in the modulation of the local CA1 hippocampal network by NMDA, mGlu5, adenosine A2A and cannabinoid CB1 receptors. Neuroscience 2016; 317:47-64. [PMID: 26762803 DOI: 10.1016/j.neuroscience.2015.12.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/23/2015] [Accepted: 12/30/2015] [Indexed: 11/29/2022]
Abstract
Recent research points to diversification in the local neuronal circuitry between dorsal (DH) and ventral (VH) hippocampus that may be involved in the large-scale functional segregation along the long axis of the hippocampus. Here, using CA1 field recordings from rat hippocampal slices, we show that activation of N-methyl-d-aspartate receptors (NMDARs) reduced excitatory transmission more in VH than in DH, with an adenosine A1 receptor-independent mechanism, and reduced inhibition and enhanced postsynaptic excitability only in DH. Strikingly, co-activation of metabotropic glutamate receptor-5 (mGluR5) with NMDAR, by CHPG and NMDA respectively, strongly potentiated the effects of NMDAR in DH but had not any potentiating effect in VH. Furthermore, the synergistic actions in DH were occluded by blockade of adenosine A2A receptors (A2ARs) by their antagonist ZM 241385 demonstrating a tonic action of these receptors in DH. Exogenous activation of A2ARs by 4-[2-[[6-amino-9-(N-ethyl-β-D-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzenepropanoic acid hydrochloride (CGS 21680) did not change the effects of mGluR5-NMDAR co-activation in either hippocampal pole. Importantly, blockade of cannabinoid CB1 receptors (CB1Rs) by their antagonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-4-morpholinyl-1H-pyrazole-3-carboxamide (AM 281) restricted the synergistic actions of mGluR5-NMDARs on excitatory synaptic transmission and postsynaptic excitability and abolished their effect on inhibition. Furthermore, AM 281 increased the excitatory transmission only in DH indicating that CB1Rs were tonically active in DH but not VH. Removing the magnesium ions from the perfusion medium neither stimulated the interaction between mGluR5 and NMDAR in VH nor augmented the synergy of the two receptors in DH. These findings show that the NMDAR-dependent modulation of fundamental parameters of the local neuronal network, by mGluR5, A2AR and CB1R, markedly differs between DH and VH. We propose that the higher modulatory role of A2AR and mGluR5, in combination with the role of CB1Rs, provide DH with higher functional flexibility of its NMDARs, compared with VH.
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Affiliation(s)
- S Kouvaros
- Laboratory of Physiology, Department of Medicine, School of Health Sciences, University of Patras, 26504 Rion, Greece
| | - C Papatheodoropoulos
- Laboratory of Physiology, Department of Medicine, School of Health Sciences, University of Patras, 26504 Rion, Greece.
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Activation of mGluR5 Attenuates Microglial Activation and Neuronal Apoptosis in Early Brain Injury After Experimental Subarachnoid Hemorrhage in Rats. Neurochem Res 2015; 40:1121-32. [DOI: 10.1007/s11064-015-1572-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 03/27/2015] [Accepted: 04/01/2015] [Indexed: 12/23/2022]
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Kritis AA, Stamoula EG, Paniskaki KA, Vavilis TD. Researching glutamate - induced cytotoxicity in different cell lines: a comparative/collective analysis/study. Front Cell Neurosci 2015; 9:91. [PMID: 25852482 PMCID: PMC4362409 DOI: 10.3389/fncel.2015.00091] [Citation(s) in RCA: 227] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/26/2015] [Indexed: 12/21/2022] Open
Abstract
Although glutamate is one of the most important excitatory neurotransmitters of the central nervous system, its excessive extracellular concentration leads to uncontrolled continuous depolarization of neurons, a toxic process called, excitotoxicity. In excitotoxicity glutamate triggers the rise of intracellular Ca2+ levels, followed by up regulation of nNOS, dysfunction of mitochondria, ROS production, ER stress, and release of lysosomal enzymes. Excessive calcium concentration is the key mediator of glutamate toxicity through over activation of ionotropic and metabotropic receptors. In addition, glutamate accumulation can also inhibit cystine (CySS) uptake by reversing the action of the CySS/glutamate antiporter. Reversal of the antiporter action reinforces the aforementioned events by depleting neurons of cysteine and eventually glutathione’s reducing potential. Various cell lines have been employed in the pursuit to understand the mechanism(s) by which excitotoxicity affects the cells leading them ultimately to their demise. In some cell lines glutamate toxicity is exerted mainly through over activation of NMDA, AMPA, or kainate receptors whereas in other cell lines lacking such receptors, the toxicity is due to glutamate induced oxidative stress. However, in the greatest majority of the cell lines ionotropic glutamate receptors are present, co-existing to CySS/glutamate antiporters and metabotropic glutamate receptors, supporting the assumption that excitotoxicity effect in these cells is accumulative. Different cell lines differ in their responses when exposed to glutamate. In this review article the responses of PC12, SH-SY5Y, HT-22, NT-2, OLCs, C6, primary rat cortical neurons, RGC-5, and SCN2.2 cell systems are systematically collected and analyzed.
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Affiliation(s)
- Aristeidis A Kritis
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Eleni G Stamoula
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Krystallenia A Paniskaki
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Theofanis D Vavilis
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
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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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Overk CR, Cartier A, Shaked G, Rockenstein E, Ubhi K, Spencer B, Price DL, Patrick C, Desplats P, Masliah E. Hippocampal neuronal cells that accumulate α-synuclein fragments are more vulnerable to Aβ oligomer toxicity via mGluR5--implications for dementia with Lewy bodies. Mol Neurodegener 2014; 9:18. [PMID: 24885390 PMCID: PMC4041038 DOI: 10.1186/1750-1326-9-18] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/13/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In dementia with Lewy bodies (DLB) abnormal interactions between α-synuclein (α-syn) and beta amyloid (Aβ) result in selective degeneration of neurons in the neocortex, limbic system and striatum. However, factors rendering these neurons selectively vulnerable have not been fully investigated. The metabotropic glutamate receptor 5 (mGluR5) has been shown to be up regulated in DLB and might play a role as a mediator of the neurotoxic effects of Aβ and α-syn in vulnerable neuronal populations. In this context, the main objective of the present study was to investigate the role of mGluR5 as a mediator of the neurotoxic effects of α-syn and Aβ in the hippocampus. RESULTS We generated double transgenic mice over-expressing amyloid precursor protein (APP) and α-syn under the mThy1 cassette and investigated the relationship between α-syn cleavage, Aβ, mGluR5 and neurodegeneration in the hippocampus. We found that compared to the single tg mice, the α-syn/APP tg mice displayed greater accumulation of α-syn and mGluR5 in the CA3 region of the hippocampus compared to the CA1 and other regions. This was accompanied by loss of CA3 (but not CA1) neurons in the single and α-syn/APP tg mice and greater loss of MAP 2 and synaptophysin in the CA3 in the α-syn/APP tg. mGluR5 gene transfer using a lentiviral vector into the hippocampus CA1 region resulted in greater α-syn accumulation and neurodegeneration in the single and α-syn/APP tg mice. In contrast, silencing mGluR5 with a lenti-shRNA protected neurons in the CA3 region of tg mice. In vitro, greater toxicity was observed in primary hippocampal neuronal cultures treated with Aβ oligomers and over-expressing α-syn; this effect was attenuated by down-regulating mGluR5 with an shRNA lentiviral vector. In α-syn-expressing neuronal cells lines, Aβ oligomers promoted increased intracellular calcium levels, calpain activation and α-syn cleavage resulting in caspase-3-dependent cell death. Treatment with pharmacological mGluR5 inhibitors such as 2-Methyl-6-(phenylethynyl)pyridine (MPEP) and 3-((2-Methyl-4-thiazolyl)ethynyl)pyridine (MTEP) attenuated the toxic effects of Aβ in α-syn-expressing neuronal cells. CONCLUSIONS Together, these results support the possibility that vulnerability of hippocampal neurons to α-syn and Aβ might be mediated via mGluR5. Moreover, therapeutical interventions targeting mGluR5 might have a role in DLB.
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Affiliation(s)
- Cassia R Overk
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Anna Cartier
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Gideon Shaked
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Edward Rockenstein
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Kiren Ubhi
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Brian Spencer
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | | | - Christina Patrick
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Paula Desplats
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
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Kumar J, Hapidin H, Bee YTG, Ismail Z. Effects of the mGluR5 antagonist MPEP on ethanol withdrawal induced anxiety-like syndrome in rats. Behav Brain Funct 2013; 9:43. [PMID: 24279870 PMCID: PMC4222772 DOI: 10.1186/1744-9081-9-43] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 11/23/2013] [Indexed: 11/22/2022] Open
Abstract
Abstinence from chronic ethanol consumption leads to the manifestation of a variety of symptoms attributed to central nervous system hyperexcitability, such as increased irritability, anxiety, and restlessness. Recent studies have demonstrated the importance of metabotropic glutamate receptor 5 (mGluR5) in addictive behaviours. This study investigates the effects of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) on ethanol withdrawal induced anxiety using two behavioural paradigms. Male Wistar rats were fed a Modified Liquid Diet (MLD) containing low fat cow milk, sucrose, and maltodextrin with a gradual introduction of 2.4%, 4.8% and 7.2% ethanol for 20 days. Six hours into ethanol withdrawal, the rats were intraperitoneally injected with normal saline and MPEP (2.5, 5.0, 10, 20, 30 mg/kg) and were assessed for ethanol withdrawal induced anxiety-like syndrome using an automated elevated plus maze and an open field. MPEP at 10 mg/kg significantly attenuated ethanol withdrawal induced anxiety without any compromising effects on locomotor activities. Despite reversing several indices of ethanol withdrawal induced anxiety in both the elevated plus maze and the open field, low doses of MPEP (2.5, 5 mg/kg) significantly compromised the locomotor activities of ethanol withdrawn rats. High doses of MPEP (20 and 30 mg/kg) significantly attenuated withdrawal anxiety when tested in the elevated plus maze but not in the open field. Administration of MPEP (2.5, 5, 10, 20, 30 mg/kg) has no significant compromising effect on the locomotor activities of ethanol naïve rats. Despite significantly reducing withdrawal anxiety in both behavioural paradigms at 10 mg/kg, the compromising effects of low and high doses of MPEP must be further explored along with the therapeutic efficiency of this drug for relieving withdrawal induced anxiety.
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Affiliation(s)
- Jaya Kumar
- BRAINetwork Centre for Neurocognitive Science, School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia.
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Narayanan KL, Subramaniam S, Bengston CP, Irmady K, Unsicker K, von Bohlen und Halbach O. Role of transient receptor potential channel 1 (TRPC1) in glutamate-induced cell death in the hippocampal cell line HT22. J Mol Neurosci 2013; 52:425-33. [PMID: 24242951 DOI: 10.1007/s12031-013-0171-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 10/31/2013] [Indexed: 02/06/2023]
Abstract
Transient receptor potential channel 1 (TRPC1; a cation channel activated by store depletion and/or through an intracellular messenger) is expressed in a variety of tissues, including the brain. To study the physiological function of TRPC1, we investigated the role of endogenously expressed TRPC1 in glutamate-induced cell death, using the murine hippocampal cell line HT22. Knocking down TRPC1 mRNA using TRPC1-shRNA or blocking of TRPC channels using 2-APB (≥200 μM) robustly attenuated glutamate-induced cell death after 24 h of incubation with 5 mM glutamate. Glutamate toxicity in HT22 cells seems to involve metabotropic glutamate receptor mGluR5 since MPEP (2-methyl-6-(phenylethynyl)-pyridine), an mGluR5 antagonist (≥100 μM), abrogated glutamate toxicity. Furthermore, a direct activation of mGluR5 by CHPG [(RS)-chloro-5-hydroxyphenylglycine; 100 μM or 300 μM] promoted HT22 cell death. TRPC1 knock-down markedly reduced CHPG-induced cell death. These observations suggest that glutamate-induced cell death in HT22 cells activates mGluR5 receptors, which significantly increases Ca(2+) influx through TRPC1 channels. TRPC1 knock-down prevented glutamate- and CHPG-induced cell death, suggesting that glutamate-induced toxicity in HT22 cells is mediated through TRPC1 channels and an mGluR5-dependent pathway. Together, this work provides evidence for a novel receptor activation pathway of TRPC1 in glutamate-induced toxicity.
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Affiliation(s)
- K Lakshmi Narayanan
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, 02129-4404, USA
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Kandratavicius L, Rosa-Neto P, Monteiro MR, Guiot MC, Assirati JA, Carlotti CG, Kobayashi E, Leite JP. Distinct increased metabotropic glutamate receptor type 5 (mGluR5) in temporal lobe epilepsy with and without hippocampal sclerosis. Hippocampus 2013; 23:1212-30. [PMID: 23804486 PMCID: PMC4165311 DOI: 10.1002/hipo.22160] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2013] [Indexed: 12/04/2022]
Abstract
Metabotropic glutamate receptor type 5 (mGluR5) upregulation in temporal lobe epilepsy (TLE) and the correlation of its expression with features of hippocampal sclerosis (HS) remains unclear. Here we characterized mGluR5 immunoreactivity in hippocampus, entorhinal cortex (EC), and subiculum of TLE specimens with confirmed HS, with neocortical TLE (non-HS) and necropsy controls. We correlated mGluR5 immunoreactivity with neuronal density, mossy fiber sprouting, astrogliosis (GFAP), and dendritic alterations (MAP2). TLE specimens showed increased mGluR5 expression, which was most pronounced in the EC, subiculum, CA2, and dentate gyrus outer molecular layer. Increased mGluR5 expression was seen in hippocampal head and body segments and was independent of neuronal density, astrogliosis, or dendritic alterations. Positive correlation between mGluR5 expression with mossy fiber sprouting and with MAP2 in CA3 and CA1 was found only in HS specimens. Negative correlation between mGluR5 expression with seizure frequency and epilepsy duration was found only in non-HS cases. Specimens from HS patients without previous history of febrile seizure (FS) showed higher mGluR5 and MAP2 expression in CA2. Our study suggests that mGluR5 upregulation is part of a repertoire of post-synaptic adaptations that might control overexcitation and excessive glutamate release rather than a dysfunction that leads to seizure facilitation. That would explain why non-HS cases, on which seizures are likely to originate outside the hippocampal formation, also exhibit upregulated mGluR5. On the other hand, lower mGluR5 expression was related to increased seizure frequency. In addition to its role in hyperexcitability, mGluR5 upregulation could play a role in counterbalance mechanisms along the hyperexcitable circuitry uniquely altered in sclerotic hippocampal formation. Inefficient post-synaptic compensatory morphological (dendritic branching) and glutamatergic (mGluR5 expression) mechanisms in CA2 subfield could potentially underlie the association of FS with HS and TLE. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- Ludmyla Kandratavicius
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, Department of Neurology and Neurosurgery, Douglas Research Institute, McGill UniversityMontreal, Canada
| | - Mariana Raquel Monteiro
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
| | - Marie-Christine Guiot
- Department of Pathology, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | | | | | - Eliane Kobayashi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | - Joao Pereira Leite
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
- *Correspondence to: Joao Pereira Leite, Ribeirao Preto Medical School, Department of Neurosciences and Behavior, University of Sao Paulo, Av Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil. E-mail:
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Sourial M, Cheng C, Doering LC. Progress toward therapeutic potential for AFQ056 in Fragile X syndrome. J Exp Pharmacol 2013; 5:45-54. [PMID: 27186135 PMCID: PMC4863540 DOI: 10.2147/jep.s27044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading single-gene cause of autism. It is caused by the lack of production of the Fragile X mental retardation protein (FMRP), resulting in cognitive deficits, hyperactivity, and autistic behaviors. Breakthrough advances in potential therapy for FXS followed the discovery that aberrant group 1 metabotropic glutamate receptor (mGluR) signaling is an important constituent of the pathophysiology of the syndrome. Research has indicated that upon neuronal stimulation, FMRP acts downstream of group 1 mGluRs (mGluRs1/5) to inhibit protein synthesis, long-term depression, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor internalization. To offset the deficits caused by the lack of FMRP, many pharmaceutical companies have designed medicinal drugs to target the unrestrained stimulation of mGluR5 signaling in FXS. Indeed, promising results from animal and clinical studies suggest that mGluR5 antagonists such as AFQ056 can successfully correct many of the deficits in FXS. In this review, we cover the animal studies performed to date that test the role of AFQ056 as a selective mGluR5 antagonist to alleviate the phenotypes of FXS.
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Affiliation(s)
- Mary Sourial
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Connie Cheng
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Laurie C Doering
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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Wang JW, Wang HD, Cong ZX, Zhang XS, Zhou XM, Zhang DD. Activation of metabotropic glutamate receptor 5 reduces the secondary brain injury after traumatic brain injury in rats. Biochem Biophys Res Commun 2012; 430:1016-21. [PMID: 23261470 DOI: 10.1016/j.bbrc.2012.12.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 12/10/2012] [Indexed: 12/23/2022]
Abstract
A wealth of evidence has shown that microglia-associated neuro-inflammation is involved in the secondary brain injury contributed to the poor outcome after traumatic brain injury (TBI). In vitro studies were reported that activation of metabotropic glutamate receptor 5 (mGluR5) could inhibit the microglia-associated inflammation in response to lipopolysaccharide and our previous study indicated that mGluR5 was expressed in activated microglia following TBI. However, there is little known about whether mGluR5 activation can provide neuro-protection and reduce microglia-associated neuro-inflammation in rats after TBI. The goal of the present study was to investigate the effects of mGluR5 activation with selective agonist CHPG, on cerebral edema, neuronal degeneration, microglia activation and the releasing of pro-inflammatory cytokines, in a rat model of TBI. Rats were randomly distributed into various subgroups undergoing the sham surgery or TBI procedures, and 250 nmol of CHPG or equal volume vehicle was given through intracerebroventricular injection at 30 min post-TBI. All rats were sacrificed at 24 h after TBI for the further measurements. Our data indicated that post-TBI treatment with CHPG could significantly reduce the secondary brain injury characterized by the cerebral edema and neuronal degeneration, lead to the inhibition of microglia activation and decrease the expression of pro-inflammatory cytokines in both mRNA transcription and protein synthesis. These results provide the substantial evidence that activation of mGluR5 reduces the secondary brain injury after TBI, in part, through modulating microglia-associated neuro-inflammation.
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Affiliation(s)
- Jia-Wei Wang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
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25
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Chronic administration of AFQ056/Mavoglurant restores social behaviour in Fmr1 knockout mice. Behav Brain Res 2012; 239:72-9. [PMID: 23142366 DOI: 10.1016/j.bbr.2012.10.059] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/26/2012] [Accepted: 10/30/2012] [Indexed: 11/24/2022]
Abstract
Fragile X syndrome is caused by lack of FMR1 protein (FMRP) leading to severe symptoms, including intellectual disability, hyperactivity and autistic-like behaviour. FMRP is an RNA binding protein involved in the regulation of translation of specific target mRNAs upon stimulation of metabotropic glutamate receptor 5 (mGluR5) at the synapse. The absence of FMRP leads to enhanced activity of mGluR5 signal transduction pathways. Many conflicting results have been reported regarding social behaviour deficits in Fmr1 knockout mice, and little is known about the involvement of mGluR5 pathways on social behaviour. In this study, a three-chambered task was used to determine sociability and preference for social novelty in Fmr1 knockout mice. Disruption of Fmr1 functioning resulted in enhanced interaction with stranger mouse during sociability while no significant changes were observed during preference for social novelty assay. Chronic administration of a specific mGluR5 antagonist, AFQ056/Mavoglurant, was able to restore sociability behaviour of Fmr1 knockout mice to levels of wild type littermates. These results support the importance of mGluR5 signalling pathways on social interaction behaviour and that AFQ056/Mavoglurant might be useful as potential therapeutic intervention to rescue various behavioural aspects of the fragile X phenotype.
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Wang JW, Wang HD, Zhong WZ, Li N, Cong ZX. Expression and cell distribution of metabotropic glutamate receptor 5 in the rat cortex following traumatic brain injury. Brain Res 2012; 1464:73-81. [DOI: 10.1016/j.brainres.2012.05.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 04/22/2012] [Accepted: 05/06/2012] [Indexed: 01/20/2023]
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Targeting metabotropic glutamate receptors in neuroimmune communication. Neuropharmacology 2012; 63:501-6. [PMID: 22640632 DOI: 10.1016/j.neuropharm.2012.05.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/15/2012] [Accepted: 05/17/2012] [Indexed: 01/13/2023]
Abstract
L-Glutamate (L-Glu) is the principal excitatory neurotransmitter in the Central Nervous System (CNS), where it regulates cellular and synaptic activity, neuronal plasticity, cell survival and other relevant functions. Glutamatergic neurotransmission is complex and involves both ionotropic (ligand-gated ion channels; iGluRs) and metabotropic receptors (G-protein coupled receptors). Recent evidence suggests that glutamatergic receptors are also expressed by immune cells, regulating the degree of cell activation. In this review we primarily focus on mGluRs and their role in the crosstalk between the central nervous and immune systems during neuroinflammation.
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Śmiałowska M, Gołembiowska K, Kajta M, Zięba B, Dziubina A, Domin H. Selective mGluR1 antagonist EMQMCM inhibits the kainate-induced excitotoxicity in primary neuronal cultures and in the rat hippocampus. Neurotox Res 2012; 21:379-92. [PMID: 22144346 PMCID: PMC3296950 DOI: 10.1007/s12640-011-9293-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 11/07/2011] [Accepted: 11/23/2011] [Indexed: 10/25/2022]
Abstract
Abundant evidence suggests that indirect inhibitory modulation of glutamatergic transmission, via metabotropic glutamatergic receptors (mGluR), may induce neuroprotection. The present study was designed to determine whether the selective antagonist of mGluR1 (3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxy-cyclohexyl)-methanone methanesulfonate (EMQMCM), showed neuroprotection against the kainate (KA)-induced excitotoxicity in vitro and in vivo. In in vitro studies on mouse primary cortical and hippocampal neuronal cultures, incubation with KA (150 μM) induced strong degeneration [measured as lactate dehydrogenase (LDH) efflux] and apoptosis (measured as caspase-3 activity). EMQMCM (0.1-100 μM) added 30 min to 6 h after KA, significantly attenuated the KA-induced LDH release and prevented the increase in caspase-3 activity in the cultures. Those effects were dose- and time-dependent. In in vivo studies KA (2.5 nmol/1 μl) was unilaterally injected into the rat dorsal CA1 hippocampal region. Degeneration was calculated by counting surviving neurons in the CA pyramidal layer using stereological methods. It was found that EMQMCM (5-10 nmol/1 μl) injected into the dorsal hippocampus 30 min, 1 h, or 3 h (the higher dose only) after KA significantly prevented the KA-induced neuronal degeneration. In vivo microdialysis studies in rat hippocampus showed that EMQMCM (100 μM) significantly increased γ-aminobutyric acid (GABA) and decreased glutamate release. When perfused simultaneously with KA, EMQMCM substantially increased GABA release and prevented the KA-induced glutamate release. The obtained results indicate that the mGluR1 antagonist, EMQMCM, may exert neuroprotection against excitotoxicity after delayed treatment (30 min to 6 h). The role of enhanced GABAergic transmission in the neuroprotection is postulated.
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Affiliation(s)
- Maria Śmiałowska
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland.
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Loane DJ, Stoica BA, Faden AI. Metabotropic glutamate receptor-mediated signaling in neuroglia. ACTA ACUST UNITED AC 2012; 1:136-150. [PMID: 22662309 DOI: 10.1002/wmts.30] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are G-protein-coupled receptors, which include eight subtypes that have been classified into three groups (I-III) based upon sequence homology, signal transduction mechanism and pharmacological profile. Although most studied with regard to neuronal function and modulation, mGlu receptors are also expressed by neuroglia-including astrocytes, microglia and oligodendrocytes. Activation of mGlu receptors on neuroglia under both physiologic and pathophysiologic conditions mediates numerous actions that are essential for intrinsic glial cell function, as well as for glial-neuronal interactions. Astrocyte mGlu receptors play important physiological roles in regulating neurotransmission and maintaining neuronal homeostasis. However, mGlu receptors on astrocytes and microglia also serve to modulate cell death and neurological function in a variety of pathophysiological conditions such as acute and chronic neurodegenerative disorders. The latter effects are complex and bi-directional, depending on which mGlu receptor sub-types are activated.
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Affiliation(s)
- David J Loane
- Department of Anesthesiology & Center for Shock, Trauma and Anesthesiology Research (STAR), National Study Center for Trauma and EMS, University of Maryland School of Medicine, Baltimore, MD
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Levenga J, Hayashi S, de Vrij FMS, Koekkoek SK, van der Linde HC, Nieuwenhuizen I, Song C, Buijsen RAM, Pop AS, Gomezmancilla B, Nelson DL, Willemsen R, Gasparini F, Oostra BA. AFQ056, a new mGluR5 antagonist for treatment of fragile X syndrome. Neurobiol Dis 2011; 42:311-7. [PMID: 21316452 DOI: 10.1016/j.nbd.2011.01.022] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 01/13/2011] [Accepted: 01/28/2011] [Indexed: 11/29/2022] Open
Abstract
Fragile X syndrome, the most common form of inherited intellectual disability, is caused by a lack of FMRP, which is the product of the Fmr1 gene. FMRP is an RNA-binding protein and a component of RNA-granules found in the dendrites of neurons. At the synapse, FMRP is involved in regulation of translation of specific target mRNAs upon stimulation of mGluR5 receptors. In this study, we test the effects of a new mGluR5 antagonist (AFQ056) on the prepulse inhibition of startle response in mice. We show that Fmr1 KO mice have a deficit in inhibition of the startle response after a prepulse and that AFQ056 can rescue this phenotype. We also studied the effect of AFQ056 on cultured Fmr1 KO hippocampal neurons; untreated neurons showed elongated spines and treatment resulted in shortened spines. These results suggest that AFQ056 might be a potent mGluR5 antagonist to rescue various aspects of the fragile X phenotype.
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Affiliation(s)
- Josien Levenga
- Department of Clinical Genetics, Erasmus MC, Dr Molewaterplein 50, 3015 GE Rotterdam, The Netherlands
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31
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Treatment of cerebral ischemia by disrupting ischemia-induced interaction of nNOS with PSD-95. Nat Med 2010; 16:1439-43. [PMID: 21102461 DOI: 10.1038/nm.2245] [Citation(s) in RCA: 306] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 09/20/2010] [Indexed: 02/08/2023]
Abstract
Stroke is a major public health problem leading to high rates of death and disability in adults. Excessive stimulation of N-methyl-D-aspartate receptors (NMDARs) and the resulting neuronal nitric oxide synthase (nNOS) activation are crucial for neuronal injury after stroke insult. However, directly inhibiting NMDARs or nNOS can cause severe side effects because they have key physiological functions in the CNS. Here we show that cerebral ischemia induces the interaction of nNOS with postsynaptic density protein-95 (PSD-95). Disrupting nNOS-PSD-95 interaction via overexpressing the N-terminal amino acid residues 1-133 of nNOS (nNOS-N(1-133)) prevented glutamate-induced excitotoxicity and cerebral ischemic damage. Given the mechanism of nNOS-PSD-95 interaction, we developed a series of compounds and discovered a small-molecular inhibitor of the nNOS-PSD-95 interaction, ZL006. This drug blocked the ischemia-induced nNOS-PSD-95 association selectively, had potent neuroprotective activity in vitro and ameliorated focal cerebral ischemic damage in mice and rats subjected to middle cerebral artery occlusion (MCAO) and reperfusion. Moreover, it readily crossed the blood-brain barrier, did not inhibit NMDAR function, catalytic activity of nNOS or spatial memory, and had no effect on aggressive behaviors. Thus, this new drug may serve as a treatment for stroke, perhaps without major side effects.
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Domin H, Zięba B, Gołembiowska K, Kowalska M, Dziubina A, Śmiałowska M. Neuroprotective potential of mGluR5 antagonist MTEP: effects on kainate-induced excitotoxicity in the rat hippocampus. Pharmacol Rep 2010; 62:1051-61. [DOI: 10.1016/s1734-1140(10)70367-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/19/2010] [Indexed: 11/16/2022]
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Black YD, Xiao D, Pellegrino D, Kachroo A, Brownell AL, Schwarzschild MA. Protective effect of metabotropic glutamate mGluR5 receptor elimination in a 6-hydroxydopamine model of Parkinson's disease. Neurosci Lett 2010; 486:161-5. [PMID: 20854878 DOI: 10.1016/j.neulet.2010.09.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 09/12/2010] [Accepted: 09/14/2010] [Indexed: 11/26/2022]
Abstract
Pharmacologic or genetic blockade of metabotropic glutamate mGlu5 receptors (mGluR5) has been shown to attenuate parkinsonian motor deficits and protect nigrostriatal neurons from damage in the acute MPTP model of Parkinson's disease (PD), suggesting that therapeutically targeting the mGluR5 receptor may offer a novel approach to improving motor symptoms and/or slowing neurodegeneration in PD. This study further explored the neuroprotective potential of targeting mGluR5 receptors. We examined the behavioral and neurochemical effects of receptor elimination on toxicity induced by intra-striatal application of 6-hydroxydopamine (6-OHDA), thought to represent a comparatively progressive model of PD. mGluR5 knockout (KO) mice and wild-type (WT) littermates received unilateral 6-OHDA infusions. Reflecting the imbalance expected following unilateral infusion, WT but not KO mice demonstrated predominantly ipsilateral forepaw use and robust ipsilateral amphetamine-induced rotation. Further, performance on the vertical pole descent task was profoundly impaired in WT mice, while KO mice completed the task significantly faster. Consistent with the behavioral observations, neurochemical analyses of striatal dopamine depletion showed significantly diminished severity in KO mice with only 64% of striatal dopamine lost, compared to 92% in WT mice. The absence of brain mGluR5 receptors in living KO mice was verified using positron emission tomography (PET). Our findings substantiate the key role of mGluR5 receptors in animal models of PD, strengthening the rationale for the development of mGluR5 antagonists for their neuroprotective, as well as symptomatic, benefit.
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Affiliation(s)
- Yolanda D Black
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
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Malter JS, Ray BC, Westmark PR, Westmark CJ. Fragile X Syndrome and Alzheimer's Disease: Another story about APP and beta-amyloid. Curr Alzheimer Res 2010; 7:200-6. [PMID: 20088809 DOI: 10.2174/156720510791050957] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 11/24/2009] [Indexed: 01/05/2023]
Abstract
As the mechanisms underlying neuronal development and degeneration become clarified, a number of common effectors and signaling pathways are becoming apparent. Here we describe the identification of Abeta, long considered a pathologic mediator of Alzheimers Disease and Down Syndrome, as similarly over-expressed in the neurodevelopmental disease, Fragile X Syndrome. We also show that mGluR5 inhibitors, currently employed for the treatment of Fragile X, reduce Abeta production in rodent models of Fragile X and AD as well as reduce disease phenotypes including seizures. Thus seemingly disparate neurologic diseases may share a common pathologic instigator and be treatable with a common, currently available class of therapeutics.
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Affiliation(s)
- J S Malter
- Department of Pathology, Waisman Center for Developmental Disabilities, UWMadison, WI, USA.
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McIldowie MJ, Gandy MN, Skelton BW, Brotchie JM, Koutsantonis GA, Spackman MA, Piggott MJ. Physical and crystallographic characterisation of the mGlu5 antagonist MTEP and its monohydrochloride. J Pharm Sci 2010; 99:234-45. [DOI: 10.1002/jps.21823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Byrnes KR, Stoica B, Loane DJ, Riccio A, Davis MI, Faden AI. Metabotropic glutamate receptor 5 activation inhibits microglial associated inflammation and neurotoxicity. Glia 2009; 57:550-60. [PMID: 18816644 DOI: 10.1002/glia.20783] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Group I metabotropic glutamate receptor 5 (mGluR5) can modulate addiction, pain, and neuronal cell death. Expression of some mGluRs, such as Group II and III mGluRs, has been reported in microglia and may affect their activation. However, the expression and role of mGluR5 in microglia is unclear. Using immunocytochemistry and Western blot, we demonstrate that mGluR5 protein is expressed in primary microglial cultures. Activation of mGluR5 using the selective agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) significantly reduces microglial activation in response to lipopolysaccharide, as indicated by a reduction in nitric oxide, reactive oxygen species, and TNFalpha production. Microglial induced neurotoxicity is also markedly reduced by CHPG treatment. The anti-inflammatory effects of CHPG are not observed in microglial cultures from mGluR5 knockout mice and are blocked by selective mGluR5 antagonists, suggesting that these actions are mediated by the mGluR5 receptor. Anti-inflammatory actions of mGluR5 activation are attenuated by phospholipase C and protein kinase C inhibitors, as well as by calcium chelators, suggesting that the mGluR5 activation in microglia involves the G(alphaq)-protein signal transduction pathway. These data indicate that microglial mGluR5 may represent a novel target for modulating neuroinflammation, an important component of both acute and chronic neurodegenerative disorders.
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Affiliation(s)
- Kimberly R Byrnes
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington, DC 20057, USA.
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Loane DJ, Stoica BA, Pajoohesh-Ganji A, Byrnes KR, Faden AI. Activation of metabotropic glutamate receptor 5 modulates microglial reactivity and neurotoxicity by inhibiting NADPH oxidase. J Biol Chem 2009; 284:15629-39. [PMID: 19364772 DOI: 10.1074/jbc.m806139200] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microglial-related factors have been implicated in the signaling cascades that contribute to neuronal cell death in various neurodegenerative disorders. Thus, strategies that reduce microglial activation and associated neurotoxicity may have therapeutic benefit. Group II and III metabotropic glutamate receptors (mGluRs) are expressed in microglia and can modulate microglial activity in primary cell cultures. We demonstrate that the group I receptor member mGluR5 is highly expressed in primary microglial cultures and the BV2 microglial cell line. Activation of mGluR5 using the selective agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) significantly attenuates microglial activation in response to lipopolysaccharide and interferon-gamma, as indicated by a reduction in the expression of inducible nitric-oxide synthase, production of nitric oxide and tumor necrosis factor-alpha, and intracellular generation of reactive oxygen species. In addition, microglial-induced neurotoxicity is also markedly reduced by CHPG treatment. The anti-inflammatory effects of CHPG are mediated by the mGluR5 receptor, because either a selective mGluR5 antagonist or small interference RNA knockdown attenuated the actions of this drug. CHPG blocked the lipopolysaccharide-induced increase in expression and enzymatic activity of NADPH oxidase. Moreover, the protective effects of CHPG were significantly reduced when the NADPH oxidase subunits p22(phox) or gp91(phox) were knocked down by small interference RNA. These data suggest that mGluR5 represents a novel target for modulating microglial-dependent neuroinflammation, and may have therapeutic relevance for neurological disorders that exhibit microglial-mediated neurodegeneration.
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Affiliation(s)
- David J Loane
- Department of Neuroscience, Georgetown University Medical Center, Washington, D C 20057, USA.
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Byrnes KR, Loane DJ, Faden AI. Metabotropic glutamate receptors as targets for multipotential treatment of neurological disorders. Neurotherapeutics 2009; 6:94-107. [PMID: 19110202 PMCID: PMC2634659 DOI: 10.1016/j.nurt.2008.10.038] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Glutamate is a major excitatory neurotransmitter in the CNS that is involved in numerous cellular functions, including cell death and survival. Metabotropic glutamate receptors (mGluR) are G-protein coupled receptors that have been classified into three groups on the basis of signal transduction pathways and pharmacological profiles. Group I, II, and III mGluRs are found on cell types within and peripheral to the CNS, including neurons, microglia, astrocytes, oligodendrocytes, T- and B-cell lymphocytes, osteoblasts, hepatocytes, and endothelial cells, among others. These receptors have a number of effects on cells that can influence outcome after trauma, including reducing neuronal and oligodendroglial cell death, inflammation, and endothelial permeability. Thus, mGluRs are a promising multipotential therapeutic approach. Because the pathology of CNS trauma and neurodegeneration is multifactorial (including, for example, oxidative stress, mitochondrial breakdown, and inflammation), therapies that serve to modulate multiple pathophysiological pathways may prove more effective than those directed at a single target. This review examines the multipotential therapeutic utility of mGluR modulation in acute and chronic injury and neurodegeneration.
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Affiliation(s)
- Kimberly R Byrnes
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA.
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39
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Elevated glycogen synthase kinase-3 activity in Fragile X mice: key metabolic regulator with evidence for treatment potential. Neuropharmacology 2008; 56:463-72. [PMID: 18952114 DOI: 10.1016/j.neuropharm.2008.09.017] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/20/2008] [Accepted: 09/30/2008] [Indexed: 11/20/2022]
Abstract
Significant advances have been made in understanding the underlying defects of and developing potential treatments for Fragile X syndrome (FXS), the most common heritable mental retardation. It has been shown that neuronal metabotropic glutamate receptor 5 (mGluR5)-mediated signaling is affected in FX animal models, with consequent alterations in activity-dependent protein translation and synaptic spine functionality. We demonstrate here that a central metabolic regulatory enzyme, glycogen synthase kinase-3 (GSK3) is present in a form indicating elevated activity in several regions of the FX mouse brain. Furthermore, we show that selective GSK3 inhibitors, as well as lithium, are able to revert mutant phenotypes of the FX mouse. Lithium, in particular, remained effective with chronic administration, although its effects were reversible even when given from birth. The combination of an mGluR5 antagonist and GSK3 inhibitors was not additive. Instead, it was discovered that mGluR5 signaling and GSK3 activation in the FX mouse are coordinately elevated, with inhibition of mGluR5 leading to inhibition of GSK3. These findings raise the possibility that GSK3 is a fundamental and central component of FXS pathology, with a substantial treatment potential.
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Platt DM, Rowlett JK, Spealman RD. Attenuation of cocaine self-administration in squirrel monkeys following repeated administration of the mGluR5 antagonist MPEP: comparison with dizocilpine. Psychopharmacology (Berl) 2008; 200:167-76. [PMID: 18509621 PMCID: PMC2536745 DOI: 10.1007/s00213-008-1191-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 04/26/2008] [Indexed: 10/22/2022]
Abstract
RATIONALE The mGluR5 antagonist MPEP has effects that suggest potential as a pharmacotherapy for cocaine addiction. MPEP can attenuate self-administration of cocaine in animals; however, studies usually involved only acute treatment with MPEP and a single dose of self-administered cocaine. Cocaine addicts use varied amounts of cocaine over long periods of time, and an effective pharmacotherapy would almost certainly require more chronic treatment. OBJECTIVES The present study (1) compared the effects of repeated treatment with MPEP or the NMDA receptor antagonist dizocilpine on the reinforcing effects of a range of doses of cocaine and (2) determined the pharmacological specificity of the effects of the drugs in attenuating cocaine self-administration compared to food-reinforced behavior. An effective pharmacotherapy should selectively reduce cocaine self-administration. MATERIALS AND METHODS Groups of monkeys responded under a fixed-ratio schedule of i.v. cocaine self-administration or food-pellet delivery. The effects of daily treatment with MPEP and dizocilpine were determined under both the schedule of i.v. cocaine injection and food delivery. RESULTS Treatment with MPEP and dizocilpine significantly reduced cocaine self-administration, producing rightward and downward shifts in the ascending limb of the cocaine dose-response function. MPEP and dizocilpine selectively and significantly attenuated self-administration of a low reinforcing dose of cocaine compared to food without evidence of tolerance. CONCLUSIONS Both MPEP and dizocilpine functioned as partially surmountable antagonists of the reinforcing effects of cocaine. The similar effects of the two drugs raises the possibility that MPEP attenuated the reinforcing effects of cocaine, at least in part, via mGluR5-mediated inhibition of NMDA receptor activity.
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Affiliation(s)
- Donna M Platt
- New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, P.O. Box 9102, Southborough, MA 01772-9102, USA.
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41
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mGlu5 receptor deletion does not confer seizure protection to mice. Life Sci 2008; 83:377-80. [PMID: 18675825 DOI: 10.1016/j.lfs.2008.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 06/17/2008] [Accepted: 07/06/2008] [Indexed: 11/23/2022]
Abstract
Metabotropic glutamate mGlu5 receptors have been implicated in the regulation of seizures and have been suggested as a target against which discovery of novel anticonvulsants may be possible. However, the experimental literature is not consistent in reporting anticonvulsant efficacy of mGlu5 receptor antagonists. Additional assessment of this target was approached in the present study by comparing convulsions in wild-type (WT) and mGlu5 receptor null (knockout or KO) mice. Chemically induced seizures induced by a variety of mechanisms including pentylenetetrazole, N-methyl-d-aspartic acid (NMDA), cocaine, kainic acid, aminophylline, 4-aminopyridine, strychnine, and nicotine did not differentially increase clonic, clonic/tonic, or lethality in WT vs. mGlu5 receptor KO mice. The mGlu5 receptor antagonist 3-[(2-Methyl-1,3-thiazol-4-yl) ethynyl]-pyridine (MTEP) did not significantly prevent seizures induced by NMDA; in contrast, the uncompetitive NMDA receptor antagonist, dizocilpine, significantly prevented NMDA-induced seizures and lethality in both WT and KO mice. The present findings do not support the idea that mGlu5 receptors play as important a role in seizure control as previously speculated.
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Rumbaugh JA, Steiner J, Sacktor N, Nath A. Developing neuroprotective strategies for treatment of HIV-associated neurocognitive dysfunction. ACTA ACUST UNITED AC 2008; 2:271-280. [PMID: 19774095 DOI: 10.2217/17469600.2.3.271] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Important advances have been made in recent years in identifying the molecular mechanisms of HIV neuropathogenesis. Defining the pathways leading to HIV dementia has created an opportunity to therapeutically target many steps in the pathogenic process. HIV itself rarely infects neurons, but significant neuronal damage is caused both by viral proteins and by inflammatory mediators produced by the host in response to infection. Highly active antiretroviral therapy (HAART) does not target these mediators of neuronal damage, and the prevalence of HIV-associated neurocognitive dysfunction has actually been rising in the post-HAART era. This review will briefly summarize our current understanding of the mechanisms of HIV-induced neurological disease, and emphasize translation of this basic research into potential clinical applications.
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Affiliation(s)
- Jeffrey A Rumbaugh
- Johns Hopkins University School of Medicine, Department of Neurology, 600 North Wolfe Street, Baltimore, MD 21287, USA, Tel.: +1 443 287 4656; ;
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de Vrij FMS, Levenga J, van der Linde HC, Koekkoek SK, De Zeeuw CI, Nelson DL, Oostra BA, Willemsen R. Rescue of behavioral phenotype and neuronal protrusion morphology in Fmr1 KO mice. Neurobiol Dis 2008; 31:127-32. [PMID: 18571098 DOI: 10.1016/j.nbd.2008.04.002] [Citation(s) in RCA: 217] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 04/01/2008] [Accepted: 04/17/2008] [Indexed: 10/22/2022] Open
Abstract
Lack of fragile X mental retardation protein (FMRP) causes Fragile X Syndrome, the most common form of inherited mental retardation. FMRP is an RNA-binding protein and is a component of messenger ribonucleoprotein complexes, associated with brain polyribosomes, including dendritic polysomes. FMRP is therefore thought to be involved in translational control of specific mRNAs at synaptic sites. In mice lacking FMRP, protein synthesis-dependent synaptic plasticity is altered and structural malformations of dendritic protrusions occur. One hypothesized cause of the disease mechanism is based on exaggerated group I mGluR receptor activation. In this study, we examined the effect of the mGluR5 antagonist MPEP on Fragile X related behavior in Fmr1 KO mice. Our results demonstrate a clear defect in prepulse inhibition of startle in Fmr1 KO mice, that could be rescued by MPEP. Moreover, we show for the first time a structural rescue of Fragile X related protrusion morphology with two independent mGluR5 antagonists.
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Affiliation(s)
- Femke M S de Vrij
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
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44
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Lea PM, Faden AI. Metabotropic glutamate receptor subtype 5 antagonists MPEP and MTEP. CNS DRUG REVIEWS 2006; 12:149-66. [PMID: 16958988 PMCID: PMC6494124 DOI: 10.1111/j.1527-3458.2006.00149.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glutamate regulates the function of central nervous system (CNS), in part, through the cAMP and/or IP3/DAG second messenger-associated metabotropic glutamate receptors (mGluRs). The mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) has been extensively used to elucidate potential physiological and pathophysiological functions of mGluR5. Unfortunately, recent evidence indicates significant non-specific actions of MPEP, including inhibition of NMDA receptors. In contrast, in vivo and in vitro characterization of the newer mGluR5 antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) indicates that it is more highly selective for mGluR5 over mGluR1, has no effect on other mGluR subtypes, and has fewer off-target effects than MPEP. This article reviews literature on both of these mGluR5 antagonists, which suggests their possible utility in neurodegeneration, addiction, anxiety and pain management.
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Affiliation(s)
| | - Alan I. Faden
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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45
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Movsesyan VA, Faden AI. Neuroprotective effects of selective group II mGluR activation in brain trauma and traumatic neuronal injury. J Neurotrauma 2006; 23:117-27. [PMID: 16503796 DOI: 10.1089/neu.2006.23.117] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effects of group II mGluR activation by selective agonist (-)-2-oxa-4-aminobicyclo[3.1. 0]hexane-4,6-dicarboxylate (LY379268) were examined in a mouse model of controlled cortical impact (CCI)-induced brain injury and in primary neuronal/glial and neuronal cultures subjected to mechanical trauma. Systemic administration of LY379268 to mice at 30 min after CCI significantly improved both motor and cognitive recovery as compared with vehicle-treated control animals. LY379268 also significantly reduced cell death induced by mechanical injury in rat neuronal/glial and neuronal cultures, as measured by lactate dehydrogenase (LDH) release assay. The neuroprotective effect of LY379268 in vitro was abolished by co-administration of the mGluR2/3 antagonist (s)-alpha-ethylglutamic acid (EGLU); however, co-application of selective mGluR3 antagonist beta-N-acetyl-aspartyl-glutamate (NAAG) had no significant influence in the same system. Together, these findings demonstrate the neuroprotective activity of group II mGluR activation and underscore the role of the mGluR2 subtype for this effect.
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Affiliation(s)
- Vilen A Movsesyan
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA
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Löscher W, Dekundy A, Nagel J, Danysz W, Parsons CG, Potschka H. mGlu1 and mGlu5 receptor antagonists lack anticonvulsant efficacy in rodent models of difficult-to-treat partial epilepsy. Neuropharmacology 2006; 50:1006-15. [PMID: 16563443 DOI: 10.1016/j.neuropharm.2006.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Revised: 01/26/2006] [Accepted: 02/01/2006] [Indexed: 10/24/2022]
Abstract
Modulation of metabotropic glutamate (mGlu) receptors represents an interesting new approach for the treatment of a range of neurological and psychiatric disorders. Several lines of evidence suggest that functional blockade of group I (mGlu1 and mGlu5) receptors may be beneficial for treatment of epileptic seizures. This study was conducted to investigate whether mGlu1 or mGlu5 receptor antagonists have the potential to block partial or secondarily generalized seizures as occurring in partial epilepsy, the most common and difficult-to-treat type of epilepsy in patients. For this purpose, we systemically administered novel highly selective and brain penetrable group I mGlu receptor antagonists, i.e., the mGlu1 receptor antagonist EMQMCM [3-ethyl-2-methyl-quinolin-6-yl-(4-methoxy-cyclohexyl)-methanone methanesulfonate] and the mGlu5 receptor antagonist MTEP ([(2-methyl-1,3-thiazol-4-yl) ethynyl] pyridine), at doses appropriate for mGlu1 or mGlu5 receptor-mediated effects in rodent models of partial seizures. Two models were used: the 6-Hz electroshock model of partial seizures in mice and the amygdala-kindling model in rats. Clinically established antiepileptic drugs were included in the experiments for comparison. Antiepileptic drugs exerted significant anticonvulsant effects in both models, while EMQMCM and MTEP were ineffective in this regard, although both compounds were administered up to doses associated with essentially full receptor occupancy and with typical mGlu receptor-mediated effects in rodent models of anxiety or pain. Brain microdialysis for determining extracellular levels of MTEP following i.p. administration in rats substantiated that effective brain concentrations were reached at times of our experiments in seizure models. The present results do not support a significant anticonvulsant potential of group I mGlu receptor antagonists in rodent models of difficult-to-treat partial epilepsy.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany.
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Kachroo A, Orlando LR, Grandy DK, Chen JF, Young AB, Schwarzschild MA. Interactions between metabotropic glutamate 5 and adenosine A2A receptors in normal and parkinsonian mice. J Neurosci 2006; 25:10414-9. [PMID: 16280580 PMCID: PMC6725827 DOI: 10.1523/jneurosci.3660-05.2005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Evidence for heteromeric receptor complexes comprising adenosine A2A and metabotropic glutamate 5 (mGlu5) receptors in striatum has raised the possibility of synergistic interactions between striatal A2A and mGlu5 receptors. We investigated the role of striatal A2A receptors in the locomotor stimulant and antiparkinsonian properties of mGlu5 antagonists using complementary pharmacologic and genetic approaches. Locomotion acutely stimulated by the mGlu5 antagonist [2-methyl-6-(phenylethynyl)-pyridine (MPEP)] was absent in mGlu5 knock-out (KO) mice and was potentiated by an A2A antagonist KW-6002 [(E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methylxanthine], both in normal and in dopamine-depleted (reserpinized) mice. Conversely, the MPEP-induced motor response was markedly attenuated in single and double A2A and D2 receptor KO mice. In contrast, motor stimulation by a D1 dopamine agonist was not attenuated in the KO mice. The A2A receptor dependence of MPEP-induced motor stimulation was investigated further using a postnatal forebrain-specific conditional (Cre/loxP system) KO of the A2A receptor. MPEP loses the ability to stimulate locomotion in conditional KO mice, suggesting that this mGlu5 antagonist effect requires the postdevelopmental action of striatal A2A receptors. The potentiation of mGlu5 antagonist-induced motor stimulation by an A2A antagonist and its dependence on both D2 and forebrain A2A receptors highlight the functional interdependence of these receptors. These data also strengthen a rationale for pursuing a combinational drug strategy for enhancing the antiparkinsonian effects of A2A and mGlu5 antagonists.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Analysis of Variance
- Animals
- Animals, Newborn
- Behavior, Animal/drug effects
- Blotting, Western/methods
- Disease Models, Animal
- Dopamine Agonists/pharmacology
- Dose-Response Relationship, Drug
- Drug Synergism
- Excitatory Amino Acid Antagonists/pharmacology
- Locomotion/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Motor Activity/drug effects
- Parkinson Disease/drug therapy
- Parkinson Disease/genetics
- Parkinson Disease/metabolism
- Purines/pharmacology
- Pyridines/pharmacology
- Receptor, Adenosine A2A/deficiency
- Receptor, Adenosine A2A/physiology
- Receptor, Metabotropic Glutamate 5
- Receptors, Dopamine D2/deficiency
- Receptors, Metabotropic Glutamate/deficiency
- Receptors, Metabotropic Glutamate/physiology
- Time Factors
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Affiliation(s)
- Anil Kachroo
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts 02129, USA
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