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Kozol RA, Dallman JE. Drugs prescribed for Phelan-McDermid syndrome differentially impact sensory behaviors in shank3 zebrafish models. F1000Res 2023; 12:84. [PMID: 37868296 PMCID: PMC10589628 DOI: 10.12688/f1000research.127830.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 10/24/2023] Open
Abstract
Background: Altered sensory processing is a pervasive symptom in individuals with Autism Spectrum Disorders (ASD); people with Phelan McDermid syndrome (PMS), in particular, show reduced responses to sensory stimuli. PMS is caused by deletions of the terminal end of chromosome 22 or point mutations in Shank3. People with PMS can present with an array of symptoms including ASD, epilepsy, gastrointestinal distress, and reduced responses to sensory stimuli. People with PMS are often medicated to manage behaviors like aggression and/or self-harm and/or epilepsy, and it remains unclear how these medications might impact perception/sensory processing. Here we test this using zebrafish mutant shank3ab PMS models that likewise show reduced sensory responses in a visual motor response (VMR) assay, in which increased locomotion is triggered by light to dark transitions. Methods: We screened three medications, risperidone, lithium chloride (LiCl), and carbamazepine (CBZ), prescribed to people with PMS and one drug, 2-methyl-6-(phenylethynyl) pyridine (MPEP) tested in rodent models of PMS, for their effects on a sensory-induced behavior in two zebrafish PMS models with frameshift mutations in either the N- or C- termini. To test how pharmacological treatments affect the VMR, we exposed larvae to selected drugs for 24 hours and then quantified their locomotion during four ten-minute cycles of lights on-to-off stimuli. Results: We found that risperidone normalized the VMR in shank3 models. LiCl and CBZ had no effect on the VMR in any of the three genotypes. MPEP reduced the VMR in wildtype (WT) to levels seen in shank3 models but caused no changes in either shank3 model. Finally, shank3 mutants showed resistance to the seizure-inducing drug pentylenetetrazol (PTZ), at a dosage that results in hyperactive swimming in WT zebrafish. Conclusions: Our work shows that the effects of drugs on sensory processing are varied in ways that can be highly genotype- and drug-dependent.
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Affiliation(s)
- Robert A. Kozol
- Charles E. Schmidt College of Science, Florida Atlantic University, Jupiter, Fl., USA
| | - Julia E. Dallman
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
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Cheng S, Xu J, Wang W, Wang R, Li H, Jiang Z, Liu D, Pan F. Inhibition of mGluR5 alters BDNF/TrkB and GLT-1 expression in the prefrontal cortex and hippocampus and ameliorates PTSD-like behavior in rats. Psychopharmacology (Berl) 2023; 240:837-851. [PMID: 36725696 DOI: 10.1007/s00213-023-06325-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/23/2023] [Indexed: 02/03/2023]
Abstract
RATIONALE AND OBJECTIVE Post-traumatic stress disorder (PTSD) is a prevalent and debilitating psychiatric disorder. However, its specific etiological mechanism remains unclear. Previous studies have shown that traumatic stress changes metabotropic glutamate receptor 5 (mGluR5) expression in the hippocampus (HIP) and prefrontal cortex (PFC). More importantly, mGluR5 expression is often accompanied by alterations in brain-derived neurotrophic factor (BDNF). Furthermore, BDNF/tropomyosin-associated kinase B (TrkB) signaling plays multiple roles, including roles in neuroplasticity and antidepressant activity, by regulating glutamate transporter-1 (GLT-1) expression. This study aims to explore the effects of inhibiting mGluR5 on PTSD-like behaviors and BDNF, TrkB, and GLT-1 expression in the HIP and PFC of inevitable foot shock (IFS)-treated rats. METHODS Seven-day IFS was used to establish a PTSD rat model, and 2-methyl-6-(phenylethynyl)-pyridine (MPEP) (10 mg/kg, intraperitoneal injection) was used to inhibit the activity of mGluR5 during IFS in rats. After modeling, behavioral changes and mGluR5, BDNF, TrkB, and GLT-1 expression in the PFC and HIP were examined. RESULTS First, the IFS procedure induced PTSD-like behavior. Second, IFS increased the expression of mGluR5 and decreased BDNF, TrkB, and GLT-1 expression in the PFC and HIP. Third, the mGluR5 antagonist blocked the above behavioral and molecular alterations. CONCLUSIONS mGluR5 was involved in IFS-induced PTSD-like behavior by changing BDNF, TrkB, and GLT-1 expression.
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Affiliation(s)
- Shuyue Cheng
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Jingjing Xu
- Department of Clinical Psychology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, 758 Hefei Road, Qingdao, 266035, Shandong, China
| | - Wei Wang
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Rui Wang
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Haonan Li
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Zhijun Jiang
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Dexiang Liu
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Fang Pan
- Department of Medical Psychology and Ethics, School of Basic Medical Medicine Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China.
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Ferrigno A, Cagna M, Bosco O, Trucchi M, Berardo C, Nicoletti F, Vairetti M, Di Pasqua LG. MPEP Attenuates Intrahepatic Fat Accumulation in Obese Mice. Int J Mol Sci 2023; 24:ijms24076076. [PMID: 37047048 PMCID: PMC10094379 DOI: 10.3390/ijms24076076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
The blockade of metabotropic glutamate receptor type 5 (mGluR5) was previously found to reduce fat accumulation in HEPG2 cells. Here, we evaluated the effects of mGluR5 blockade in a mouse model of steatosis. Male ob/ob mice fed a high-fat diet were treated with MPEP or vehicle. After 7 weeks, liver biopsies were collected, and nuclei were isolated from fresh tissue. Lipid droplet area and collagen deposition were evaluated on tissue slices; total lipids, lipid peroxidation, and ROS were evaluated on tissue homogenates; PPARα, SREBP-1, mTOR, and NF-κB were assayed on isolated nuclei by Western Blot. Target genes of the above-mentioned factors were assayed by RT-PCR. Reduced steatosis and hepatocyte ballooning were observed in the MPEP group with respect to the vehicle group. Concomitantly, increased nuclear PPARα and reduced nuclear SREBP-1 levels were observed in the MPEP group. Similar trends were obtained in target genes of PPARα and SREBP-1, Acox1 and Acc1, respectively. MPEP administration also reduced oxidative stress and NF-κB activation, probably via NF-κB inhibition. Levels of common markers of inflammation (Il-6, Il1β and Tnf-α) and oxidative stress (Nrf2) were significantly reduced. mTOR, as well as collagen deposition, were unchanged. Concluding, MPEP, a selective mGluR5 negative allosteric modulator, reduces both fat accumulation and oxidative stress in a 7-week murine model of steatosis. Although underlying mechanisms need to be further investigated, this is the first in vivo study showing the beneficial effects of MPEP in a murine model of steatosis.
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Affiliation(s)
- Andrea Ferrigno
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), 56122 Pisa, Italy
| | - Marta Cagna
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
| | - Oriana Bosco
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
| | - Michelangelo Trucchi
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
| | - Clarissa Berardo
- Department of Biomedical and Clinical Science, University of Milano, 20157 Milano, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
- IRCCS Neuromed, 86077 Pozzilli, Italy
| | - Mariapia Vairetti
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
| | - Laura G Di Pasqua
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy
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Chen Y, Zhang Y, Chen Q, Liu Y, Wei X, Wu M, Zhang K, Liu Y, Wei W. Inhibition of mGluR5/PI3K-AKT Pathway Alleviates Alzheimer's Disease-Like Pathology Through the Activation of Autophagy in 5XFAD Mice. J Alzheimers Dis 2023; 91:1197-1214. [PMID: 36565127 DOI: 10.3233/jad-221058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND The metabotropic glutamate receptor 5 (mGluR5) is widely expressed in postsynaptic neurons and plays a vital role in the synaptic plasticity of the central nervous system. mGluR5 is a coreceptor for amyloid-β (Aβ) oligomer, and downregulation or pharmacological blockade of mGluR5 presents the therapeutic potential of Alzheimer's disease (AD). However, the abnormality of mGluR5 in the pathogenesis of AD and its mechanism of pathology is not clear. OBJECTIVE In this study, we would like to investigate the expression of mGluR5 in the process of AD and explore the effects and the underlying mechanisms of antagonizing mGluR5 on cognitive function, synaptic structure, and inflammation in 5xFAD mice. METHODS mGluR5 expression and interactions with PrPc in 5XFAD mice were detected using western blot and co-immunoprecipitation. The selective mGluR5 antagonist MPEP was infused into 4-month-old 5XFAD mice for 60 consecutive days. Then, cognitive function, AD-like pathology and synaptic structure were measured. Further observations were made in mGluR5 knockdown 5XFAD mice. RESULTS mGluR5 expression was increased with Aβ levels at 6 months in 5XFAD mice. mGluR5 antagonist rescued cognitive disorders, promoted synaptic recovery, and alleviated both the Aβ plaque load and abnormal hyperphosphorylation in 6-month-old 5XFAD mice. Meanwhile, the results were validated in mGluR5 knockdown mice. Blockade of mGluR5 efficiently alleviates AD-like pathologies by inhibiting the PI3K/AKT/mTOR pathway and activates autophagy in 5XFAD mice. Furthermore, antagonism of mGluR5 attenuated neuroinflammation by inactivating the IKK/NF-κB pathway. CONCLUSION These findings suggest that mGluR5 may be an effective drug target for AD treatment, and inhibition of the mGluR5/PI3K-AKT pathway alleviates AD-like pathology by activating autophagy and anti-neuroinflammation in 5XFAD mice.
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Affiliation(s)
- Yuzhao Chen
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Yilin Zhang
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Qiuxuan Chen
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Yuxiang Liu
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Xuemin Wei
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Meijian Wu
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Keke Zhang
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
| | - Yinghua Liu
- Department of Pharmacology, Guangzhou Municipaland Guangdong Provincial Key Laboratory of Molecular Target &Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
| | - Wei Wei
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou, P. R. China
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Chang HA, Dai W, Hu SSJ. Sex differences in cocaine-associated memory: The interplay between CB 1, mGluR5, and estradiol. Psychoneuroendocrinology 2021; 133:105366. [PMID: 34419761 DOI: 10.1016/j.psyneuen.2021.105366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 07/16/2021] [Accepted: 07/22/2021] [Indexed: 10/20/2022]
Abstract
We know surprisingly little about the sex differences in the neurobiology of cocaine addiction, except females are more susceptible to the rewarding effects of cocaine than their male counterparts. Only a handful of recent studies have examined the neurobiology of cocaine-induced conditioned place preference (CPP) memory among female rodents. We contribute to this emerging line of research by documenting sex differences in cocaine-associated memory and illustrating the underlying signaling pathways in five experiments. Rimonabant (Rim), a cannabinoid CB1 antagonist and inverse agonist, exerted a facilitating effect for low-dose cocaine and an impairing effect for high-dose cocaine CPP memory in male mice, as in our previous study, but not in female mice. Nor did we observe the effect exist among CB1 knockout male mice, which indicated that the CB1 receptors played a mediating role. We also found that the metabotropic glutamate receptor 5 (mGluR5) was located in the same signaling pathway as CB1 in male mice. To clarify the mechanisms behind the sex differences, we used ovariectomized (OVX) female mice with estradiol benzoate (EB) replacement. In the OVX female mice, we showed that Rim-alone and EB-alone, but not Rim-and-EB-combined, facilitated the low-dose cocaine CPP memory. Moreover, 4-hydroxytamoxifen (4-OHT), an estrogen receptor (ER) antagonist, blocked Rim's and EB's facilitating effect. Finally, 2-methyl-6-(phenylethynyl)pyridine (MPEP), an mGluR5 antagonist, partially blocked EB's facilitating effect. In sum, we identified sex-specific effects of Rim on cocaine-induced CPP memory and the respective signaling pathways: mGluR5-CB1 for male mice and ER-mGluR5-CB1 for female mice. These findings may have merits for the development of sex-specific treatment for cocaine addiction.
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Affiliation(s)
- Heng-Ai Chang
- Department of Psychology, National Cheng Kung University, Tainan 70101, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan
| | - Wen Dai
- Department of Psychology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Sherry Shu-Jung Hu
- Department of Psychology, National Cheng Kung University, Tainan 70101, Taiwan.
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6
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Di Pasqua LG, Berardo C, Cagna M, Verta R, Collotta D, Nicoletti F, Ferrigno A, Collino M, Vairetti M. Metabotropic Glutamate Receptor Blockade Reduces Preservation Damage in Livers from Donors after Cardiac Death. Int J Mol Sci 2021; 22:ijms22052234. [PMID: 33668105 PMCID: PMC7956702 DOI: 10.3390/ijms22052234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 12/13/2022] Open
Abstract
We previously demonstrated that the blockade of mGluR5 by 2-methyl-6(phenylethynyl)pyridine (MPEP) reduces both cold and warm ischemia/reperfusion injury. Here we evaluated whether MPEP reduces the hepatic preservation injury in rat livers from cardiac-death-donors (DCDs). Livers from DCD rats were isolated after an in situ warm ischemia (30 min) and preserved for 22 h at 4 °C with UW solution. Next, 10 mg/Kg MPEP or vehicle were administered 30 min before the portal clamping and added to the UW solution (3 µM). LDH released during washout was quantified. Liver samples were collected for iNOS, eNOS, NO, TNF-α, ICAM-1, caspase-3 and caspase-9 protein expression and nuclear factor-erythroid-2-related factor-2 (Nrf2) gene analysis. Lower LDH levels were detected in control grafts versus DCD groups. An increase in eNOS and NO content occurred after MPEP treatment; iNOS and TNF-α content was unchanged. ICAM-1 expression was reduced in the MPEP-treated livers as well as the levels of caspase-3 and caspase-9. Nrf2, oxidative stress-sensitive gene, was recovered to control value by MPEP. These results suggest that MPEP can be used to reclaim DCD livers subjected to an additional period of cold ischemia during hypothermic storage. MPEP protects against apoptosis and increased eNOS, whose overexpression has been previously demonstrated to be protective in hepatic ischemia/reperfusion damage.
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Affiliation(s)
- Laura Giuseppina Di Pasqua
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy; (L.G.D.P.); (M.C.); (M.V.)
| | - Clarissa Berardo
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy; (L.G.D.P.); (M.C.); (M.V.)
- Correspondence: (C.B.); (A.F.); Tel.: +39-0382-986-874 (C.B.); +39-0382-986-451 (A.F.)
| | - Marta Cagna
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy; (L.G.D.P.); (M.C.); (M.V.)
| | - Roberta Verta
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (R.V.); (D.C.); (M.C.)
| | - Debora Collotta
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (R.V.); (D.C.); (M.C.)
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy;
- IRCCS Neuromed, 86077 Pozzilli, Italy
| | - Andrea Ferrigno
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy; (L.G.D.P.); (M.C.); (M.V.)
- Correspondence: (C.B.); (A.F.); Tel.: +39-0382-986-874 (C.B.); +39-0382-986-451 (A.F.)
| | - Massimo Collino
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (R.V.); (D.C.); (M.C.)
| | - Mariapia Vairetti
- Unit of Cellular and Molecular Pharmacology and Toxicology, Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy; (L.G.D.P.); (M.C.); (M.V.)
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Ricart-Ortega M, Berizzi AE, Catena J, Malhaire F, Muñoz L, Serra C, Lebon G, Goudet C, Llebaria A. Development and validation of a mass spectrometry binding assay for mGlu5 receptor. Anal Bioanal Chem 2020; 412:5525-5535. [PMID: 32564119 DOI: 10.1007/s00216-020-02772-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/03/2020] [Accepted: 06/12/2020] [Indexed: 10/24/2022]
Abstract
Mass spectrometry (MS) binding assays are a label-free alternative to radioligand or fluorescence binding assays, so the readout is based on direct mass spectrometric detection of the test ligand. The study presented here describes the development and validation of a highly sensitive, rapid, and robust MS binding assay for the quantification of the binding of the metabotropic glutamate 5 (mGlu5) negative allosteric modulator (NAM), MPEP (2-methyl-6-phenylethynylpyridine) at the mGlu5 allosteric binding site. The LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometric) analytical method was established and validated with a deuterated analogue of MPEP as an internal standard. The developed MS binding assay described here allowed for the determination of MS binding affinity estimates that were in agreement with affinity estimates obtained from a tritiated MPEP radioligand saturation binding assay, indicating the suitability of this methodology for determining affinity estimates for compounds that target mGlu5 allosteric binding sites. Graphical abstract.
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Affiliation(s)
- Maria Ricart-Ortega
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Alice E Berizzi
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Juanlo Catena
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Fanny Malhaire
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Lourdes Muñoz
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Carmen Serra
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Guillaume Lebon
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Cyril Goudet
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France.
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain. .,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.
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8
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Butkiewicz M, Rodriguez AL, Rainey SE, Wieting J, Luscombe VB, Stauffer SR, Lindsley CW, Conn PJ, Meiler J. Identification of Novel Allosteric Modulators of Metabotropic Glutamate Receptor Subtype 5 Acting at Site Distinct from 2-Methyl-6-(phenylethynyl)-pyridine Binding. ACS Chem Neurosci 2019; 10:3427-3436. [PMID: 31132237 DOI: 10.1021/acschemneuro.8b00227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
As part of the G-protein coupled receptor (GPCR) family, metabotropic glutamate (mGlu) receptors play an important role as drug targets of cognitive diseases. Selective allosteric modulators of mGlu subtype 5 (mGlu5) have the potential to alleviate symptoms of numerous central nervous system disorders such as schizophrenia in a more targeted fashion. Multiple mGlu5 positive allosteric modulators (PAMs), such as 1-(3-fluorophenyl)-N-((3-fluorophenyl)-methylideneamino)-methanimine (DFB), 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)-benzamide (CDPPB), and 4-nitro-N-(1,3-diphenyl-1H-pyrazol-5-yl)-benzamide (VU-29), exert their actions by binding to a defined allosteric site on mGlu5 located in the seven-transmembrane domain (7TM) and shared by mGlu5 negative allosteric modulator (NAM) 2-methyl-6-(phenylethynyl)-pyridine (MPEP). Actions of the PAM N-{4-chloro-2-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]phenyl}-2-hydroxybenzamide (CPPHA) are mediated by a distinct allosteric site in the 7TM domain different from the MPEP binding site. Experimental evidence confirms these findings through mutagenesis experiments involving residues F585 (TM1) and A809 (TM7). In an effort to investigate mGlu5 PAM selectivity for this alternative allosteric site distinct from MPEP binding, we employed in silico quantitative structure-activity relationship (QSAR) modeling. Subsequent ligand-based virtual screening prioritized a set of 63 candidate compounds predicted from a library of over 4 million commercially available compounds to bind exclusively to this novel site. Experimental validation verified the biological activity for seven of 63 selected candidates. Further, medicinal chemistry optimizations based on these molecules revealed compound VU6003586 with an experimentally validated potency of 174 nM. Radioligand binding experiments showed only partial inhibition at very high concentrations, most likely indicative of binding at a non-MPEP site. Selective positive allosteric modulators for mGlu5 have the potential for tremendous impact concerning devastating neurological disorders such as schizophrenia and Huntington's disease. These identified and validated novel selective compounds can serve as starting points for more specifically tailored lead and probe molecules and thus help the development of potential therapeutic agents with reduced adverse effects.
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Huang Y, Shu H, Li L, Zhen T, Zhao J, Zhou X, Luo W. L-DOPA-Induced Motor Impairment and Overexpression of Corticostriatal Synaptic Components Are Improved by the mGluR5 Antagonist MPEP in 6-OHDA-Lesioned Rats. ASN Neuro 2019; 10:1759091418811021. [PMID: 30439288 PMCID: PMC6238196 DOI: 10.1177/1759091418811021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Levodopa (L-DOPA) is still the most effective drug for the treatment of Parkinson's disease (PD). However, the long-term therapy often triggers L-DOPA-induced dyskinesia (LID). Metabotropic glutamate receptor type 5 (mGluR5) is abundant in the basal ganglia, and its inhibition is thought to modulate postsynaptic excitatory synaptic transmission and glutamate hyperactivity in PD and LID. In this report, we examined the effects of mGluR5-specific antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) on LID and synaptic components in the PD model rat. We found the selective mGluR5 antagonist MPEP attenuated abnormal involuntary movements, prolonged the duration of rotational response, reversed the decrease of left forepaw adjusting steps, and reduced overexpression of striatal mGluR5 in the LID rats. Moreover, our results showed much thicker postsynaptic densities, narrower synapse cleft, as well as the increased ratio of perforated synapses induced by L-DOPA treatment, while coadministration of L-DOPA and MPEP reversed these postsynaptic effects. Finally, MPEP reduced overexpression of the two postsynaptic proteins (PSD-95 and SAP102) induced by L-DOPA treatment. Hence, these results provide evidence that aberrant neural plasticity at corticostriatal synapses in the striatum is closely correlated with the occurrence of LID, and targeted inhibition of mGluR5 by MPEP alleviates LID in the PD rat model.
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Affiliation(s)
- Yixian Huang
- 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiyang Shu
- 2 Department of Neurology, Taikang People's Hospital of Henan Province, Taikang, China
| | - Li Li
- 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Tili Zhen
- 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Junyan Zhao
- 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Xianju Zhou
- 4 Laboratory of Neurological Diseases, Department of Neurology, Changzhou No.2 People's Hospital, The Affiliated Hospital of Nanjing Medical University, Changzhou, China
| | - Weifeng Luo
- 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China.,3 Institute of Neuroscience, Soochow University, Suzhou, China
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10
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Pourmirbabaei S, Dolatshahi M, Rahmani F. Pathophysiological clues to therapeutic applications of glutamate mGlu5 receptor antagonists in levodopa-induced dyskinesia. Eur J Pharmacol 2019; 855:149-159. [PMID: 31063776 DOI: 10.1016/j.ejphar.2019.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/29/2019] [Accepted: 05/03/2019] [Indexed: 12/16/2022]
Abstract
Levodopa remains to be the mainstay for treatment of Parkinson disease (PD). Long-term levodopa treatment bears a risk for developing levodopa-induced dyskinesia (LID). LID significantly overshadows patients' quality of life and therapeutic efficacy of levodopa. Pre- and post-synaptic changes in dopamine secretion and signaling, along with altered glutamate receptor expression and glutamatergic signaling in striatal neurons, and the resulting disinhibition-like changes in the corticostriatal circuitry, lead to aberrant activity of motor cortex and formation of LID. Research has highlighted the role of group I metabotropic glutamate receptors especially the metabotropic glutamate receptor 5 (mGlu5) in formation of LID through potentiating of ionotropic glutamate NMDA receptors and dopamine D1/D5 receptors in direct pathway. Accordingly, MTEP and MPEP were the first mGlu5 receptor antagonists which were shown to attenuate LID in animal models through suppression of downstream signaling cascades involving mitogen-activated protein kinase (MAPK) and FosB/delta FosB activation, as well as modulation of prodynorphinegic, preproenkephalinergic, and GABA-ergic neurotransmission systems. Beneficial effects of other mGlu5 receptor antagonists such as AFQ056/mavoglurant and ADX48621/dipraglurant in amelioration of LID has been shown not only in animal models but also in clinical trials. Considering the presence of mGlu receptor dysregulation in rapid eye movement (REM) sleep behavior disorder and depression, which are prodromal signs of PD, along with the neuroprotective effects of mGlu receptor antagonists, and their cognitive benefits, potential effectiveness of mGlu receptor antagonists in early prevention of PD remains to be investigated.
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Affiliation(s)
- Shayan Pourmirbabaei
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Mahsa Dolatshahi
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Farzaneh Rahmani
- Student's Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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11
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Sengmany K, Hellyer SD, Albold S, Wang T, Conn PJ, May LT, Christopoulos A, Leach K, Gregory KJ. Kinetic and system bias as drivers of metabotropic glutamate receptor 5 allosteric modulator pharmacology. Neuropharmacology 2019; 149:83-96. [PMID: 30763654 DOI: 10.1016/j.neuropharm.2019.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 01/18/2019] [Accepted: 02/04/2019] [Indexed: 12/17/2022]
Abstract
Allosteric modulators of the metabotropic glutamate receptor subtype 5 (mGlu5) have been proposed as potential therapies for various CNS disorders. These ligands bind to sites distinct from the orthosteric (or endogenous) ligand, often with improved subtype selectivity and spatio-temporal control over receptor responses. We recently revealed that mGlu5 allosteric agonists and positive allosteric modulators exhibit biased agonism and/or modulation. To establish whether negative allosteric modulators (NAMs) engender similar bias, we rigorously characterized the pharmacology of eight diverse mGlu5 NAMs. Radioligand inhibition binding studies revealed novel modes of interaction with mGlu5 for select NAMs, with biphasic or incomplete inhibition of the radiolabeled NAM, [3H]methoxy-PEPy. We assessed mGlu5-mediated intracellular Ca2+ (iCa2+) mobilization and inositol phosphate (IP1) accumulation in HEK293A cells stably expressing low levels of mGlu5 (HEK293A-rat mGlu5-low) and mouse embryonic cortical neurons. The apparent affinity of acetylenic NAMs, MPEP, MTEP and dipraglurant, was dependent on the signaling pathway measured, agonist used, and cell type (HEK293A-rat mGlu5-low versus mouse cortical neurons). In contrast, the acetylenic partial NAM, M-5MPEP, and structurally distinct NAMs (VU0366248, VU0366058, fenobam), had similar affinity estimates irrespective of the assay or cellular background. Biased modulation was evident for VU0366248 in mouse cortical neurons where it was a NAM for DHPG-mediated iCa2+ mobilization, but neutral with DHPG in IP1 accumulation assays. Overall, this study highlights the inherent complexity in mGlu5 NAM pharmacology that we hypothesize may influence interpretation when translating into preclinical models and beyond in the design and development of novel therapeutics for neuropsychiatric and neurological disorders.
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Affiliation(s)
- Kathy Sengmany
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Shane D Hellyer
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Sabine Albold
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Taide Wang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - P Jeffrey Conn
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Katie Leach
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Department of Pharmacology, Monash University, Parkville, VIC, Australia.
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12
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Liu B, Zhao S, Qi C, Zhao X, Liu B, Hao F, Zhao Z. Inhibition of metabotropic glutamate receptor 5 facilitates hypoxia-induced glioma cell death. Brain Res 2018; 1704:241-248. [PMID: 30347216 DOI: 10.1016/j.brainres.2018.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/16/2018] [Accepted: 10/18/2018] [Indexed: 10/28/2022]
Abstract
Glioma is a primary brain tumor with high frequency and dismal prognosis. As there is no permanent cure available, identifying new therapy or mediator to augment the effectiveness of existing therapy is urgently needed. In the current study we tested the effect of group I metabotropic glutamate receptors (mGluRs): mGluR1 and mGluR5 on the viability of glioma cell lines. We analyzed cell viability using lactate dehydrogenase (LDH) release assay and evaluated apoptosis by propidium iodide (PI) staining. We used qPCR to evaluate change in mitochondrial gene expression and Western blot to evaluate the phosphorylation of Akt and ERK. Inhibition of mGluR5 by a selective antagonist MPEP under hypoxia promoted cell death, and induced expression of mitochondrial oxidative function related genes, with concurrent lowering of AKT phosphorylation level in glioma cell lines. Akt activation reversed mGluR5 inhibition on hypoxia-induced glioma cell death. These results suggest mGluR5 as a potential therapeutic target for hypoxic tumors such as malignant glioma.
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Affiliation(s)
- Bo Liu
- Department of Oncological Surgery, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Xin Hua District, Shijiazhuang City 050000, Hebei Province, PR China
| | - Shuang Zhao
- Department of Anesthesiology, The Third Hospital of Hebei Medical University, No. 139, Zi Qiang Road, Qiao Xi District, Shijiazhuang City 050051, Hebei Province, PR China
| | - Cheng Qi
- Department of Oncological Surgery, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Xin Hua District, Shijiazhuang City 050000, Hebei Province, PR China
| | - Xiaodong Zhao
- Department of Oncological Surgery, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Xin Hua District, Shijiazhuang City 050000, Hebei Province, PR China
| | - Bin Liu
- Hebei Key Laboratory of Cancer Radiotherapy and Chemotherapy, Department of Medical Oncology, Affiliated Hospital of Hebei University, No. 212, East Yuhua Road, Baoding City 071000, Hebei Province, PR China
| | - Fang Hao
- Department of Oncological Surgery, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Xin Hua District, Shijiazhuang City 050000, Hebei Province, PR China
| | - Zongmao Zhao
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Xin Hua District, Shijiazhuang City 050000, Hebei Province, PR China.
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13
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Folsom TD, Higgins L, Markowski TW, Griffin TJ, Fatemi SH. Quantitative proteomics of forebrain subcellular fractions in fragile X mental retardation 1 knockout mice following acute treatment with 2-Methyl-6-(phenylethynyl)pyridine: Relevance to developmental study of schizophrenia. Synapse 2018; 73:e22069. [PMID: 30176067 DOI: 10.1002/syn.22069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 08/13/2018] [Accepted: 08/30/2018] [Indexed: 12/22/2022]
Abstract
The fragile X mental retardation 1 knockout (Fmr1 KO) mouse replicates behavioral deficits associated with autism, fragile X syndrome, and schizophrenia. Less is known whether protein expression changes are consistent with findings in subjects with schizophrenia. In the current study, we used liquid chromatography tandem mass spectrometry (LC-MS/MS) proteomics to determine the protein expression of four subcellular fractions in the forebrains of Fmr1 KO mice vs. C57BL/6 J mice and the effect of a negative allosteric modulator of mGluR5-2-Methyl-6-(phenylethynyl)pyridine (MPEP)-on protein expression. Strain- and treatment-specific differential expression of proteins was observed, many of which have previously been observed in the brains of subjects with schizophrenia. Western blotting verified the direction and magnitude of change for several proteins in different subcellular fractions as follows: neurofilament light protein (NEFL) and 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNP) in the total homogenate; heterogeneous nuclear ribonucleoproteins C1/C2 (HNRNPC) and heterogeneous nuclear ribonucleoprotein D0 (HNRNPD) in the nuclear fraction; excitatory amino acid transporter 2 (EAAT2) and ras-related protein rab 3a (RAB3A) in the synaptic fraction; and ras-related protein rab 35 (RAB35) and neuromodulin (GAP43) in the rough endoplasmic reticulum fraction. Individuals with FXS do not display symptoms of schizophrenia. However, the biomarkers that have been identified suggest that the Fmr1 KO model could potentially be useful in the study of schizophrenia.
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Affiliation(s)
- Timothy D Folsom
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, Minneapolis, Minnesota
| | - LeeAnn Higgins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Todd W Markowski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Timothy J Griffin
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota
| | - S Hossein Fatemi
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, Minneapolis, Minnesota.,Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota
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14
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Westmark PR, Dekundy A, Gravius A, Danysz W, Westmark CJ. Rescue of Fmr1 KO phenotypes with mGluR 5 inhibitors: MRZ-8456 versus AFQ-056. Neurobiol Dis 2018; 119:190-198. [PMID: 30125640 DOI: 10.1016/j.nbd.2018.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/08/2018] [Accepted: 08/13/2018] [Indexed: 12/23/2022] Open
Abstract
Metabotropic glutamate receptor 5 (mGluR5) is a drug target for central nervous system disorders such as fragile X syndrome that involve excessive glutamate-induced excitation. We tested the efficacy of a novel negative allosteric modulator of mGluR5 developed by Merz Pharmaceuticals, MRZ-8456, in comparison to MPEP and AFQ-056 (Novartis, a.k.a. mavoglurant) in both in vivo and in vitro assays in a mouse model of fragile X syndrome, Fmr1KO mice. The in vivo assays included susceptibility to audiogenic-induced seizures and pharmacokinetic measurements of drug availability. The in vitro assays included dose response assessments of biomarker expression and dendritic spine length and density in cultured primary neurons. Both MRZ-8456 and AFQ-056 attenuated wild running and audiogenic-induced seizures in Fmr1KO mice with similar pharmacokinetic profiles. Both drugs significantly reduced dendritic expression of amyloid-beta protein precursor (APP) and rescued the ratio of mature to immature dendritic spines. These findings demonstrate that MRZ-8456, a drug being developed for the treatment of motor complications of L-DOPA in Parkinson's disease and which completed a phase I clinical trial, is effective in attenuating both well-established (seizures and dendritic spine maturity) and exploratory biomarker (APP expression) phenotypes in a mouse model of fragile X syndrome.
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Affiliation(s)
- Pamela R Westmark
- University of Wisconsin-Madison, Department of Neurology, Madison, WI, USA; University of Wisconsin-Madison, Department of Medicine, Madison, WI, USA
| | - Andrzej Dekundy
- Merz Pharmaceuticals GmbH, Eckenheimer Landstrasse 100, 60318 Frankfurt am Main, Germany
| | - Andreas Gravius
- Merz Pharmaceuticals GmbH, Eckenheimer Landstrasse 100, 60318 Frankfurt am Main, Germany
| | - Wojciech Danysz
- Merz Pharmaceuticals GmbH, Eckenheimer Landstrasse 100, 60318 Frankfurt am Main, Germany
| | - Cara J Westmark
- University of Wisconsin-Madison, Department of Neurology, Madison, WI, USA.
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15
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Nissen TD, Brock C, Lykkesfeldt J, Lindström E, Hultin L. Pharmacological modulation of colorectal distension evoked potentials in conscious rats. Neuropharmacology 2018; 140:193-200. [PMID: 30059662 DOI: 10.1016/j.neuropharm.2018.07.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 07/02/2018] [Accepted: 07/24/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cerebral evoked potentials (CEP) induced by colorectal distension (CRD) in conscious rats provides a novel method in studies of visceral sensitivity. The aim of this study was to explore the pharmacological effect on CEP of compounds known to reduce the visceromotor response to CRD. METHODS Epidural electrodes were chronically implanted in eight female Sprague-Dawley rats. Evoked potentials were elicited by colorectal rapid balloon distensions (100 ms, 80 mmHg) and the effect of WIN55 (cannabinoid CB receptor agonist), clonidine (adrenergic α2 receptor agonist), MPEP (mGluR5 receptor antagonist), pregabalin (ligand of α2δ subunits in voltage-gated calcium channels) and baclofen (GABA-B receptor agonist) on amplitudes and latency of CEP were determined. RESULTS WIN55 (0.1 μmol kg-1), clonidine (0.05 μmol kg-1), MPEP (10 μmol kg-1) and pregabalin (200 μmol kg-1) caused a significant, p < 0.05, reduction of the N2 to P2 peak-to-peak amplitude by 23 ± 8%, 25 ± 8%, 39 ± 5%, and 47 ± 6% respectively. Baclofen (9 μmol kg-1) induced a prolongation of the N2 peak latency of 18 ± 4% but had no significant effect on the amplitudes. CONCLUSION The obtained results suggest that MPEP, WIN55, clonidine, and pregabalin reduce visceral nociceptive input to the brain, whereas the lack of effect of baclofen on CRD evoked CEP amplitudes suggest that the effect on VMR is not due to a direct analgesic effect. Brain responses to colorectal distension provide a useful tool to evaluate pharmacological effects in rats and may serve as a valuable preclinical model for understanding pharmacological mechanisms related to visceral sensitivity.
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Affiliation(s)
- Thomas Dahl Nissen
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden; Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark; Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Leif Hultin
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.
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16
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Ferrigno A, Berardo C, Di Pasqua LG, Siciliano V, Richelmi P, Nicoletti F, Vairetti M. Selective Blockade of the Metabotropic Glutamate Receptor mGluR5 Protects Mouse Livers in In Vitro and Ex Vivo Models of Ischemia Reperfusion Injury. Int J Mol Sci 2018; 19:E314. [PMID: 29360756 PMCID: PMC5855547 DOI: 10.3390/ijms19020314] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/18/2018] [Accepted: 01/22/2018] [Indexed: 12/13/2022] Open
Abstract
2-Methyl-6-(phenylethynyl)pyridine (MPEP), a negative allosteric modulator of the metabotropic glutamate receptor (mGluR) 5, protects hepatocytes from ischemic injury. In astrocytes and microglia, MPEP depletes ATP. These findings seem to be self-contradictory, since ATP depletion is a fundamental stressor in ischemia. This study attempted to reconstruct the mechanism of MPEP-mediated ATP depletion and the consequences of ATP depletion on protection against ischemic injury. We compared the effects of MPEP and other mGluR5 negative modulators on ATP concentration when measured in rat hepatocytes and acellular solutions. We also evaluated the effects of mGluR5 blockade on viability in rat hepatocytes exposed to hypoxia. Furthermore, we studied the effects of MPEP treatment on mouse livers subjected to cold ischemia and warm ischemia reperfusion. We found that MPEP and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) deplete ATP in hepatocytes and acellular solutions, unlike fenobam. This finding suggests that mGluR5s may not be involved, contrary to previous reports. MPEP, as well as MTEP and fenobam, improved hypoxic hepatocyte viability, suggesting that protection against ischemic injury is independent of ATP depletion. Significantly, MPEP protected mouse livers in two different ex vivo models of ischemia reperfusion injury, suggesting its possible protective deployment in the treatment of hepatic inflammatory conditions.
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Affiliation(s)
- Andrea Ferrigno
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
| | - Clarissa Berardo
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
| | - Laura Giuseppina Di Pasqua
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
| | - Veronica Siciliano
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
| | - Plinio Richelmi
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University, 00185 Roma, Italy.
- I.R.C.C.S. Neuromed, 86077 Pozzilli, Italy.
| | - Mariapia Vairetti
- Department of Internal Medicine and Therapeutics, Cellular and Molecular Pharmacology and Toxicology Unit, University of Pavia, 27100 Pavia, Italy.
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17
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Lin S, Li X, Chen YH, Gao F, Chen H, Hu NY, Huang L, Luo ZY, Liu JH, You QL, Yin YN, Li ZL, Li XW, Du ZJ, Yang JM, Gao TM. Social Isolation During Adolescence Induces Anxiety Behaviors and Enhances Firing Activity in BLA Pyramidal Neurons via mGluR5 Upregulation. Mol Neurobiol 2017; 55:5310-5320. [PMID: 28914419 DOI: 10.1007/s12035-017-0766-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 09/06/2017] [Indexed: 11/28/2022]
Abstract
Social isolation during the vulnerable period of adolescence contributes to the occurrence of psychiatric disorders and profoundly affects brain development and adult behavior. Although the impact of social isolation during adolescence on anxiety behaviors has been well studied, much less is known about the onset and underlying mechanisms of these behaviors. We observed that following 2 weeks, but not 1 week, of social isolation, adolescent mice exhibited anxiety behaviors. Strikingly, the mGluR5 protein levels in the amygdala increased concomitantly with anxiety behaviors, and both intraperitoneal administration and intra-basolateral amygdala (BLA) infusion of MPEP, a metabotropic glutamate receptor 5 antagonist, normalized anxiety behaviors. Furthermore, electrophysiological studies showed that 2 weeks of social isolation during adolescence facilitated pyramidal neuronal excitability in the BLA, which could be normalized by MPEP. Together, these results reveal a critical period in adolescence during which social isolation can induce anxiety behaviors and facilitate BLA pyramidal neuronal excitability, both of which are mediated by mGluR5, thus providing mechanistic insights into the onset of anxiety behaviors after social isolation during adolescence.
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Affiliation(s)
- Song Lin
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Xin Li
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Yi-Hua Chen
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Feng Gao
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Hao Chen
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Neng-Yuan Hu
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Lang Huang
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Zheng-Yi Luo
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Ji-Hong Liu
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Qiang-Long You
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Ya-Nan Yin
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Ze-Lin Li
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Xiao-Wen Li
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Zhuo-Jun Du
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China
| | - Jian-Ming Yang
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China.
| | - Tian-Ming Gao
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, 1023S Shatai Road, Guangzhou, 510515, China.
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Medina-Ceja L, García-Barba C. The glutamate receptor antagonists CNQX and MPEP decrease fast ripple events in rats treated with kainic acid. Neurosci Lett 2017; 655:137-142. [PMID: 28673833 DOI: 10.1016/j.neulet.2017.06.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/06/2017] [Accepted: 06/29/2017] [Indexed: 12/17/2022]
Abstract
Fast ripples (FR) are high frequency oscillations (250-600Hz) that have been associated with epilepsy. FR are assumed to be generated in small areas of the hippocampus (1mm3) that contain pathologically interconnected glutamate pyramidal cell clusters. Additionally, a relation between glutamate neurotransmission and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainite (AMPA/KA) and metabotropic mGluR5 receptors is well established. Therefore, we hypothesized that antagonism of these glutamate receptors would decrease FR activity. For this propose, we induced status epilepticus with a kainic acid injection in the posterior right hippocampus and performed intracranial EEG recordings to detect and evaluate the presence of FR 15days after the injection. The glutamate AMPA/KA receptor antagonist CNQX (10mg/kg) and the mGluR5 antagonist MPEP (20mg/kg) were administered intraperitoneally, and the effects of the drugs were evaluated for a period of three hours after their administration. The results show a decrease in the number of FR in the first hour after drug administration in both cases (CNQX, p=0.0125; MPEP, p=0.0132) and a return to basal values in the third hour of the experiment, but not significant differences in the number of oscillations per event of FR, and the frequency and duration of each event of FR. We therefore conclude that blockade of AMPA/KA and mGluR5 receptors transiently decreases the generation of FR; however, the mechanisms by which this effect is achieved are to be further analyzed in future experiments.
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Affiliation(s)
- Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Jalisco, Mexico.
| | - Carla García-Barba
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Jalisco, Mexico
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19
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Pershina EV, Kapralova MV, Arkhipov VI. Effect of Pharmacological Modulation of Activity of Metabotropic Glutamate Receptors on Their Gene Expression after Excitotoxic Damage in Hippocampal Neurons. Bull Exp Biol Med 2017; 162:784-7. [PMID: 28432493 DOI: 10.1007/s10517-017-3713-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Indexed: 01/10/2023]
Abstract
Microinjection of kainic acid into rat hippocampus causes excitotoxic neuronal damage predominantly in the CA3 and CA1 fields. These lesions can be significantly reduced by simultaneous administration of MPEP, a negative allosteric modulator of type 5 metabotropic glutamate receptors, and LY354740, an agonist of type 2 metabotropic glutamate receptors. The decrease in neuronal death in the hippocampus during pharmacological modulation was paralleled by adaptive changes in gene expression. In the hippocampus, gene expression of type 5 postsynaptic metabotropic glutamate receptor was close to the control level, and in the frontal cortex expression of the gene of α1-subunit of the GABAA receptor returned to normal. In the frontal cortex, a reciprocal relationship was observed for type 2 metabotropic glutamate receptor: expression of the corresponding gene decreased in response to pharmacological activation.
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Chen A, Hu WW, Jiang XL, Potegal M, Li H. Molecular mechanisms of group I metabotropic glutamate receptor mediated LTP and LTD in basolateral amygdala in vitro. Psychopharmacology (Berl) 2017; 234:681-694. [PMID: 28028604 DOI: 10.1007/s00213-016-4503-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 12/08/2016] [Indexed: 11/30/2022]
Abstract
The roles of group I metabotropic glutamate receptors, metabotropic glutamate receptor 1 (mGluR1) and mGluR5, in regulating synaptic plasticity and metaplasticity in the basolateral amygdala (BLA) remain unclear. The present study examined mGluR1- and mGluR5-mediated synaptic plasticity in the BLA and their respective signaling mechanisms. Bath application of the group I mGluR agonist, 3,5-dihydroxyphenylglycine (DHPG) (20 μM), directly suppressed basal fEPSPs (84.5 ± 6.3% of the baseline). The suppressive effect persisted for at least 30 min after washout; it was abolished by the mGluR1 antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) but was unaffected by the mGluR5 antagonist 2-methyl-6- (phenylethynyl)-pyridine (MPEP). Interestingly, application of DHPG (at both 2 and 20 μM), regardless of the presence of CPCCOEt, could transform single theta burst stimulation (TBS)-induced short-term synaptic potentiation into a long-term potentiation (LTP). Such a facilitating effect could be blocked by the mGluR5 antagonist MPEP. Blockade of phospholipase C (PLC), the downstream enzyme of group I mGluR, with U73122, prevented both mGluR1- and mGluR5-mediated effects on synaptic plasticity. Nevertheless, blockade of protein kinase C (PKC), the downstream enzyme of PLC, with chelerythrine (5 μM) only prevented the transforming effect of DHPG on TBS-induced LTP and did not affect DHPG-induced long-term depression (LTD). These results suggest that mGluR1 activation induced LTD via a PLC-dependent and PKC-independent mechanism, while the priming action of mGluR5 receptor on the BLA LTP is both PLC and PKC dependent. The BLA metaplasticity mediated by mGluR1 and mGluR5 may provide signal switching mechanisms mediating learning and memory with emotional significance.
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Affiliation(s)
- A Chen
- Department of Physiology, Fujian Medical University, Fuzhou, People's Republic of China
| | - W W Hu
- Department of Physiology, Fujian Medical University, Fuzhou, People's Republic of China
| | - X L Jiang
- Department of Psychiatry, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4799, USA
| | - M Potegal
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55414, USA
| | - H Li
- Department of Psychiatry, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4799, USA.
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21
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Albasanz JL, Santana S, Guzman-Sanchez F, León D, Burgos JS, Martín M. 2-Methyl-6-(phenylethynyl)pyridine Hydrochloride Modulates Metabotropic Glutamate 5 Receptors Endogenously Expressed in Zebrafish Brain. ACS Chem Neurosci 2016; 7:1690-1697. [PMID: 27635438 DOI: 10.1021/acschemneuro.6b00213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Due to phylogenetic proximity to the human, zebrafish has been recognized as a reliable model to study Alzheimer's disease (AD) and other central nervous system disorders. Furthermore, metabotropic glutamate receptors have been previously reported to be impaired in brain from AD patients. Metabotropic glutamate 5 (mGlu5) receptors are G-protein coupled receptors proposed as potential targets for therapy of different neurodegenerative disorders. Thus, MPEP (2-methyl-6-(phenylethynyl)pyridine hydrochloride), a selective noncompetitive mGlu5 receptor antagonist, has been suggested for pharmacological treatment of AD. The aim of the present work was to quantify mGlu5 receptors in brain from zebrafish and to study the possible modulation of these receptors by MPEP treatment. To this end, radioligand binding assay and open field test were used. Results showed a slightly higher presence of mGlu5 receptors in brain from male than in that from female zebrafish. However, a significant increase of mGlu5 receptor in male without variation in female was observed after MPEP treatment. This gender specific response was also observed in locomotor behavior, being significantly decreased only in male zebrafish. These results confirm the presence of mGlu5 receptors in brain from zebrafish and their gender specific modulation by selective antagonist treatment and suggest a role of these receptors on locomotor activity, which is affected in many disorders. In addition, our data point to zebrafish as a useful model to study mGlu receptor function in both healthy and pathological conditions.
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Affiliation(s)
- José Luis Albasanz
- Departamento de Química Inorgánica,
Orgánica y Bioquímica, Facultad de Medicina de Ciudad
Real/Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Centro Regional de Investigaciones Biomédicas (CRIB), Avenida Camilo José Cela 10, 13071 Ciudad Real, Spain
| | | | | | - David León
- Departamento de Química Inorgánica,
Orgánica y Bioquímica, Facultad de Medicina de Ciudad
Real/Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Centro Regional de Investigaciones Biomédicas (CRIB), Avenida Camilo José Cela 10, 13071 Ciudad Real, Spain
| | | | - Mairena Martín
- Departamento de Química Inorgánica,
Orgánica y Bioquímica, Facultad de Medicina de Ciudad
Real/Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Centro Regional de Investigaciones Biomédicas (CRIB), Avenida Camilo José Cela 10, 13071 Ciudad Real, Spain
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Buschler A, Manahan-Vaughan D. Metabotropic glutamate receptor, mGlu5, mediates enhancements of hippocampal long-term potentiation after environmental enrichment in young and old mice. Neuropharmacology 2016; 115:42-50. [PMID: 27267685 DOI: 10.1016/j.neuropharm.2016.06.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 12/24/2022]
Abstract
The metabotropic glutamate (mGlu) receptor, mGlu5, is of particular relevance for hippocampal function. It is critically required for the expression of long-term potentiation (LTP) and long-term depression (LTD), regulates neuronal oscillations, maintains the stability of place fields and is required for hippocampus-dependent memory. MGlu5-dysfunctions are associated with profound cognitive deficits in humans, and mGlu5 has been targeted as a putative cognitive enhancer. Cognitive enhancement, by means of environmental enrichment (EE) in rodents, results in improved hippocampal synaptic plasticity and memory. Here, we explored whether mGlu5 contributes to these enhancements. MGlu5-antagonism dose-dependently impaired the early phase of LTP (>4 h) in the CA1 region of young(3-4 month old) mice. Late-LTP (>24 h) was also impaired. LTP (>24 h) elicited in old (10-14 month old) mice displayed reduced sensitivity to mGlu5 antagonism. Short-term potentiation (STP, < 2 h) that was elicited by weaker afferent stimulation was unaffected by mGlu5-antagonism in both age-groups. EE significantly amplified STP (<2 h) in old and young animals, but did not increase the duration of synaptic potentiation, or promote induction of LTP. The improvement in STP was prevented by mGlu5-antagonism, in both young and old animals. These results indicate that modifications of the synapse that underlie improvements of LTP by EE require the contribution of mGlu5. Strikingly, although LTP in old mice does not critically depend on mGlu5, improvements in synaptic potentiation resulting from EE are mGlu5-dependent in old mice. Regarded in light of the known role for mGlu5 in hippocampal function and pathophysiology, these data suggest that mGlu5 regulation of synaptic information storage is pivotal to optimal hippocampal function. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Arne Buschler
- Ruhr University Bochum, Medical Faculty, Department of Neurophysiology, Bochum, Germany
| | - Denise Manahan-Vaughan
- Ruhr University Bochum, Medical Faculty, Department of Neurophysiology, Bochum, Germany.
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23
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Abstract
Conditioned cues can sometimes elicit maladaptive responses as seen in the post-traumatic stress disorder (PTSD). Lack of effective fear extinction, which involves a process of inhibitory learning, is hypothesized to associate with PTSD. In this study, we tested the effect of acute pharmacological inhibition of mGluR5 activity on the extinction of fear memory and spatial memory. Intraperitoneal injection of the mGluR5 (metabotropic glutamate receptor 5) antagonist MPEP [2-Methyl-6-(phenylethynyl) pyridine hydrochloride] allowed the retrieval but prevented the extinction of contextual fear memory in mice. Without altering locomotor activity, MPEP inhibited the acquisition but not the consolidation of contextual fear memory. Further, administration of MPEP blocked the extinction of spatial memory in the Morris water maze paradigm. Our data suggest a necessary role of mGluR5 in regulating certain aspects of behavioral flexibility.
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Affiliation(s)
- Ferzin Sethna
- Genetics Program, Michigan State University, East Lansing, MI 48824, United States
| | - Hongbing Wang
- Department of Physiology, Michigan State University, East Lansing, MI 48824, United States; Neuroscience Program, Michigan State University, East Lansing, MI 48824, United States.
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24
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Zolkowska D, Kondrat-Wrobel MW, Florek-Luszczki M, Luszczki JJ. Influence of MPEP (a selective mGluR5 antagonist) on the anticonvulsant action of novel antiepileptic drugs against maximal electroshock-induced seizures in mice. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:172-8. [PMID: 26478256 DOI: 10.1016/j.pnpbp.2015.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/12/2015] [Accepted: 10/13/2015] [Indexed: 11/25/2022]
Abstract
The aim of this study was to determine the effects of 2-methyl-6-(phenylethynyl)pyridine (MPEP - a selective antagonist for the glutamate metabotropic receptor subtype mGluR5) on the protective action of some novel antiepileptic drugs (lamotrigine, oxcarbazepine, pregabalin and topiramate) against maximal electroshock-induced seizures in mice. Brain concentrations of antiepileptic drugs were measured to determine whether MPEP altered pharmacokinetics of antiepileptic drugs. Intraperitoneal injection of 1.5 and 2mg/kg of MPEP significantly elevated the threshold for electroconvulsions in mice, whereas MPEP at a dose of 1mg/kg considerably enhanced the anticonvulsant activity of pregabalin and topiramate, but not that of lamotrigine or oxcarbazepine in the maximal electroshock-induced seizures in mice. Pharmacokinetic results revealed that MPEP (1mg/kg) did not alter total brain concentrations of pregabalin and topiramate, and the observed effect in the mouse maximal electroshock seizure model was pharmacodynamic in nature. Collectively, our preclinical data suggest that MPEP may be a safe and beneficial adjunct to the therapeutic effects of antiepileptic drugs in human patients.
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Affiliation(s)
- Dorota Zolkowska
- Department of Neurology, School of Medicine, University of California-Davis, Sacramento, CA, USA
| | | | | | - Jarogniew J Luszczki
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland; Isobolographic Analysis Laboratory, Institute of Rural Health, Lublin, Poland.
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25
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Mihov Y, Hasler G. Negative Allosteric Modulators of Metabotropic Glutamate Receptors Subtype 5 in Addiction: a Therapeutic Window. Int J Neuropsychopharmacol 2016; 19:pyw002. [PMID: 26802568 PMCID: PMC4966271 DOI: 10.1093/ijnp/pyw002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/08/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Abundant evidence at the anatomical, electrophysiological, and molecular levels implicates metabotropic glutamate receptor subtype 5 (mGluR5) in addiction. Consistently, the effects of a wide range of doses of different mGluR5 negative allosteric modulators (NAMs) have been tested in various animal models of addiction. Here, these studies were subjected to a systematic review to find out if mGluR5 NAMs have a therapeutic potential that can be translated to the clinic. METHODS Literature on consumption/self-administration and reinstatement of drug seeking as outcomes of interest published up to April 2015 was retrieved via PubMed. The review focused on the effects of systemic (i.p., i.v., s.c.) administration of the mGluR5 NAMs 3-((2-Methyl-4-thiazolyl)ethynyl)pyridine (MTEP) and 2-Methyl-6-(phenylethynyl)pyridine (MPEP) on paradigms with cocaine, ethanol, nicotine, and food in rats. RESULTS MTEP and MPEP were found to reduce self-administration of cocaine, ethanol, and nicotine at doses ≥1mg/kg and 2.5mg/kg, respectively. Dose-response relationship resembled a sigmoidal curve, with low doses not reaching statistical significance and high doses reliably inhibiting self-administration of drugs of abuse. Importantly, self-administration of cocaine, ethanol, and nicotine, but not food, was reduced by MTEP and MPEP in the dose range of 1 to 2mg/kg and 2.5 to 3.2mg/kg, respectively. This dose range corresponds to approximately 50% to 80% mGluR5 occupancy. Interestingly, the limited data found in mice and monkeys showed a similar therapeutic window. CONCLUSION Altogether, this review suggests a therapeutic window for mGluR5 NAMs that can be translated to the treatment of substance-related and addictive disorders.
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Affiliation(s)
- Yoan Mihov
- Division of Molecular Psychiatry, Translational Research Center, Psychiatric University Hospital, University of Bern, Switzerland
| | - Gregor Hasler
- Division of Molecular Psychiatry, Translational Research Center, Psychiatric University Hospital, University of Bern, Switzerland
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26
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Hagena H, Manahan-Vaughan D. mGlu5 acts as a switch for opposing forms of synaptic plasticity at mossy fiber-CA3 and commissural associational-CA3 synapses. J Neurosci 2015; 35:4999-5006. [PMID: 25810529 DOI: 10.1523/JNEUROSCI.3417-14.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Within the hippocampus, different kinds of spatial experience determine the direction of change of synaptic weights. Synaptic plasticity resulting from such experience may enable memory encoding. The CA3 region is very striking in this regard: due to the distinct molecular properties of the mossy fiber (MF) and associational-commissural (AC) synapses, it is believed that they enable working memory and pattern completion. The question arises, however, as to how information reaching these synapses results in differentiated encoding. Given its crucial role in enabling persistent synaptic plasticity in other hippocampal subfields, we speculated that the metabotropic glutamate receptor mGlu5 may regulate information encoding at MF and AC synapses. Here, we show that antagonism of mGlu5 inhibits LTP, but not LTD at MF synapses of freely behaving adult rats. Conversely, mGlu5 antagonism prevents LTD but not LTP at AC-CA3 synapses. This suggests that, under conditions in which mGlu5 is activated, LTP may be preferentially induced at MF synapses, whereas LTD is favored at AC synapses. To assess this possibility, we applied 50 Hz stimulation that should generate postsynaptic activity that corresponds to θm, the activation threshold that lies between LTP and LTD. MGlu5 activation had no effect on AC responses but potentiated MF synapses. These data suggest that mGlu5 serves as a switch that alters signal-to-noise ratios during information encoding in the CA3 region. This mechanism supports highly tuned and differentiated information storage in CA3 synapses.
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Abstract
Decades of research dedicated toward Alzheimer's disease (AD) has culminated in much of the current understanding of the neurodegeneration associated with disease. However, delineating the pathophysiology and finding a possible cure for the disease is still wanting. This is in part due to the lack of knowledge pertaining to the connecting link between neurodegenerative and neuroinflammatory pathways. Consequently, the inefficacy and ill-effects of the drugs currently available for AD encourage the need for alternative and safe therapeutic intervention. In this review we highlight the potential of mGluR5, a metabotropic glutamatergic receptor, in understanding the mechanism underlying the neuronal death and neuroinflammation in AD. We also discuss the role of mGlu5 receptor in mediating the neuron-glia interaction in the disease. Finally, we discuss the potential of mGluR5 as target for treating AD.
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Affiliation(s)
- Anil Kumar
- UGC Centre of Advanced Studies, University Institute of Pharmaceutical Sciences, Panjab University Chandigarh, India
| | - Dinesh K Dhull
- UGC Centre of Advanced Studies, University Institute of Pharmaceutical Sciences, Panjab University Chandigarh, India
| | - Pooja S Mishra
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences Bangalore, India
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28
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Morin N, Morissette M, Grégoire L, Di Paolo T. Effect of a chronic treatment with an mGlu5 receptor antagonist on brain serotonin markers in parkinsonian monkeys. Prog Neuropsychopharmacol Biol Psychiatry 2015; 56:27-38. [PMID: 25046277 DOI: 10.1016/j.pnpbp.2014.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/27/2014] [Accepted: 07/14/2014] [Indexed: 10/25/2022]
Abstract
In Parkinson's disease (PD) and l-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias (LIDs), overactivity of brain glutamate neurotransmission is documented and antiglutamatergic drugs decrease LID. Serotonin (5-HT) receptors and transporter (SERT) are also implicated in LID and we hypothesize that antiglutamatergic drugs can also regulate brain serotoninergic activity. Our aim was to investigate the long-term effect of the prototypal metabotropic glutamate 5 (mGlu5) receptor antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) with L-DOPA on basal ganglia SERT, 5-HT(1A) and 5-HT(2A) receptor levels in monkeys lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP monkeys were treated for one month with L-DOPA and developed LID while those treated with L-DOPA and MPEP (10 mg/kg) developed significantly less LID. Normal controls and saline-treated MPTP monkeys were included for biochemical analysis. The MPTP lesion and experimental treatments left unchanged striatal 5-HT concentrations. MPTP lesion induced an increase of striatal 5-HIAA concentrations similar in all MPTP monkeys as compared to controls. [(3)H]-8-OH-DPAT and [(3)H]-citalopram specific binding levels to 5-HT(1A) receptors and SERT respectively remained unchanged in the striatum and globus pallidus of all MPTP monkeys compared to controls and no difference was observed between groups of MPTP monkeys. [(3)H]-ketanserin specific binding to striatal and pallidal 5-HT2A receptors was increased in L-DOPA-treated MPTP monkeys as compared to controls, saline and L-DOPA+MPEP MPTP monkeys and no difference between the latter groups was observed; dyskinesia scores correlated positively with this binding. In conclusion, reduction of development of LID with MPEP was associated with lower striatal and pallidal 5-HT2A receptors showing that glutamate activity also affects serotoninergic markers.
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Affiliation(s)
- Nicolas Morin
- Faculty of Pharmacy, Université Laval, 1050 Avenue de la Médecine, Quebec City G1V 0A6, Canada; Neuroscience Research Unit, Centre de Recherche du CHU de Québec, 2705 Laurier Boulevard, Quebec City G1V 4G2, Canada.
| | - Marc Morissette
- Neuroscience Research Unit, Centre de Recherche du CHU de Québec, 2705 Laurier Boulevard, Quebec City G1V 4G2, Canada.
| | - Laurent Grégoire
- Neuroscience Research Unit, Centre de Recherche du CHU de Québec, 2705 Laurier Boulevard, Quebec City G1V 4G2, Canada.
| | - Thérèse Di Paolo
- Faculty of Pharmacy, Université Laval, 1050 Avenue de la Médecine, Quebec City G1V 0A6, Canada; Neuroscience Research Unit, Centre de Recherche du CHU de Québec, 2705 Laurier Boulevard, Quebec City G1V 4G2, Canada.
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29
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André MAE, Güntürkün O, Manahan-Vaughan D. The metabotropic glutamate receptor, mGlu5, is required for extinction learning that occurs in the absence of a context change. Hippocampus 2014; 25:149-58. [PMID: 25160592 PMCID: PMC4322473 DOI: 10.1002/hipo.22359] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2014] [Indexed: 11/21/2022]
Abstract
The metabotropic glutamate (mGlu) receptors and, in particular, mGlu5 are crucially involved in multiple forms of synaptic plasticity that are believed to underlie explicit memory. MGlu5 is also required for information transfer through neuronal oscillations and for spatial memory. Furthermore, mGlu5 is involved in extinction of implicit forms of learning. This places this receptor in a unique position with regard to information encoding. Here, we explored the role of this receptor in context-dependent extinction learning under constant, or changed, contextual conditions. Animals were trained over 3 days to take a left turn under 25% reward probability in a T-maze with a distinct floor pattern (Context A). On Day 4, they experienced either a floor pattern change (Context B) or the same floor pattern (Context A) in the absence of reward. After acquisition of the task, the animals were returned to the maze once more on Day 5 (Context A, no reward). Treatment with the mGlu5 antagonist, 2-methyl-6-(phenylethynyl) pyridine, before maze exposure on Day 4 completely inhibited extinction learning in the AAA paradigm but had no effect in the ABA paradigm. A subsequent return to the original context (A, on Day 5) revealed successful extinction in the AAA paradigm, but impairment of extinction in the ABA paradigm. These data support that although extinction learning in a new context is unaffected by mGlu5 antagonism, extinction of the consolidated context is impaired. This suggests that mGlu5 is intrinsically involved in enabling learning that once-relevant information is no longer valid. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Marion Agnes Emma André
- International Graduate School for Neuroscience, Ruhr University Bochum, Bochum, Germany; Department of Biopsychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
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Arkhipov V, Kapralova M, Pershina E, Gordon R. Delayed treatments with pharmacological modulators of pre- and postsynaptic mGlu receptors rescue the hippocampus from kainate-induced neurodegeneration. Neurosci Lett 2014; 570:5-9. [PMID: 24747688 DOI: 10.1016/j.neulet.2014.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/01/2014] [Accepted: 04/09/2014] [Indexed: 11/18/2022]
Abstract
Gene expression of mGluR2, mGluR3 and mGluR5 was evaluated in the hippocampus and frontal cortex in Wistar rats in 1 and 4 weeks after bilateral microinjection of kainic acid into the dorsal hippocampus. The time-course of the receptors' expression suggested their adaptive role in response on the induction of excitotoxicity. It was assumed that the decrease of kainate-induced neurodegeneration could be achieved through simultaneous activation of presynaptic mGluRs and inhibition of mGlu postsynaptic receptors. Both negative allosteric modulator of mGluR5, MPEP, and agonist of mGluR2, LY354740, were administered intraperitoneally 5 days after microinjection of kainic acid. As shown by histochemical studies with cresyl violet and Fluoro-Jade, kainate induced significant damage of hippocampal neurons in the CA3 and CA1 fields. Pharmacological treatment with the negative modulator of mGlu5 receptors in common with the agonist of mGluR2 decreased kainate-induced neurodegeneration in dorsal hippocampus.
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Affiliation(s)
- Vladimir Arkhipov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Russian Federation.
| | - Marina Kapralova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Russian Federation
| | - Ekaterina Pershina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Russian Federation; Pushchino State Institute of Natural Sciences, Russian Federation
| | - Rita Gordon
- Institute of Cell Biophysics, Russian Academy of Sciences, Russian Federation
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Morin N, Jourdain VA, Morissette M, Grégoire L, Di Paolo T. Long-term treatment with l-DOPA and an mGlu5 receptor antagonist prevents changes in brain basal ganglia dopamine receptors, their associated signaling proteins and neuropeptides in parkinsonian monkeys. Neuropharmacology 2014; 79:688-706. [PMID: 24456747 DOI: 10.1016/j.neuropharm.2014.01.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/11/2013] [Accepted: 01/07/2014] [Indexed: 01/11/2023]
Abstract
Brain glutamate overactivity is well documented in Parkinson's disease (PD) and antiglutamatergic drugs decrease L-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesias (LID); the implication of dopamine neurotransmission is not documented in this anti-LID activity. Therefore, we evaluated changes of dopamine receptors, their associated signaling proteins and neuropeptides mRNA, in normal control monkeys, in saline-treated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys and in L-DOPA-treated MPTP monkeys, without or with an adjunct treatment to reduce the development of LID: 2-methyl-6-(phenylethynyl)pyridine (MPEP), the prototypal metabotropic glutamate 5 (mGlu5) receptor antagonist. All de novo treatments were administered for 1 month and the animals were sacrificed thereafter. MPTP monkeys treated with l-DOPA + MPEP developed significantly less LID than MPTP monkeys treated with l-DOPA alone. [(3)H]SCH-23390 specific binding to D1 receptors of all MPTP monkeys was decreased as compared to controls in the basal ganglia and no difference was observed between all MPTP groups, while striatal D1 receptor mRNA levels remained unchanged. [(3)H]raclopride specific binding to striatal D2 receptors and mRNA levels of D2 receptors were increased in MPTP monkeys compared to controls; l-DOPA treatment reduced this binding in MPTP monkeys while it remained elevated with the l-DOPA + MPEP treatment. Striatal [(3)H]raclopride specific binding correlated positively with D2 receptor mRNA levels of all MPTP-lesioned monkeys. Striatal preproenkephalin/preprodynorphin mRNA levels and phosphorylated ERK1/2 and Akt/GSK3β levels increased only in L-DOPA-treated MPTP monkeys as compared to controls, saline treated-MPTP and l-DOPA + MPEP treated MPTP monkeys. Hence, reduction of development of LID with MPEP was associated with changes in D2 receptors, their associated signaling proteins and neuropeptides.
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Affiliation(s)
- Nicolas Morin
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Vincent A Jourdain
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Laurent Grégoire
- Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada
| | - Thérèse Di Paolo
- Faculty of Pharmacy, Université Laval, Quebec City G1K 7P4, Canada; Neuroscience Research Unit, Centre de recherche du CHU de Québec, Quebec City G1V 4G2, Canada.
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Nickols HH, Conn PJ. Development of allosteric modulators of GPCRs for treatment of CNS disorders. Neurobiol Dis 2014; 61:55-71. [PMID: 24076101 PMCID: PMC3875303 DOI: 10.1016/j.nbd.2013.09.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/13/2013] [Accepted: 09/17/2013] [Indexed: 12/14/2022] Open
Abstract
The discovery of allosteric modulators of G protein-coupled receptors (GPCRs) provides a promising new strategy with potential for developing novel treatments for a variety of central nervous system (CNS) disorders. Traditional drug discovery efforts targeting GPCRs have focused on developing ligands for orthosteric sites which bind endogenous ligands. Allosteric modulators target a site separate from the orthosteric site to modulate receptor function. These allosteric agents can either potentiate (positive allosteric modulator, PAM) or inhibit (negative allosteric modulator, NAM) the receptor response and often provide much greater subtype selectivity than orthosteric ligands for the same receptors. Experimental evidence has revealed more nuanced pharmacological modes of action of allosteric modulators, with some PAMs showing allosteric agonism in combination with positive allosteric modulation in response to endogenous ligand (ago-potentiators) as well as "bitopic" ligands that interact with both the allosteric and orthosteric sites. Drugs targeting the allosteric site allow for increased drug selectivity and potentially decreased adverse side effects. Promising evidence has demonstrated potential utility of a number of allosteric modulators of GPCRs in multiple CNS disorders, including neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, as well as psychiatric or neurobehavioral diseases such as anxiety, schizophrenia, and addiction.
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Key Words
- (+)-6-(2,4-dimethylphenyl)-2-ethyl-6,7-dihydrobenzo[d]oxazol-4(5H)-one
- (1-(4-cyano-4-(pyridine-2-yl)piperidine-1-yl)methyl-4-oxo-4H-quinolizine-3-carboxylic acid)
- (1S,2S)-N(1)-(3,4-dichlorophenyl)cyclohexane-1,2-dicarboxamide
- (1S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid
- (3,4-dihydro-2H-pyrano[2,3]b quinolin-7-yl)(cis-4-methoxycyclohexyl) methanone
- (3aS,5S,7aR)-methyl 5-hydroxy-5-(m-tolylethynyl)octahydro-1H-indole-1-carboxylate
- 1-(1′-(2-methylbenzyl)-1,4′-bipiperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one
- 1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- 2-(2-(3-methoxyphenyl)ethynyl)-5-methylpyridine
- 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1Himidazol-4-yl)ethynyl)pyridine
- 2-methyl-6-(2-phenylethenyl)pyridine
- 2-methyl-6-(phenylethynyl)-pyridine
- 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide
- 3-cyclohexyl-5-fluoro-6-methyl-7-(2-morpholin-4-ylethoxy)-4H-chromen-4-one
- 3[(2-methyl-1,3-thiazol-4-yl)ethylnyl]pyridine
- 4-((E)-styryl)-pyrimidin-2-ylamine
- 4-[1-(2-fluoropyridin-3-yl)-5-methyl-1H-1,2,3-triazol-4-yl]-N-isopropyl-N-methyl-3,6-dihydropyridine-1(2H)-carboxamide
- 4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine
- 5-methyl-6-(phenylethynyl)-pyridine
- 5MPEP
- 6-(4-methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one
- 6-OHDA
- 6-hydroxydopamine
- 6-methyl-2-(phenylazo)-3-pyridinol
- 77-LH-28-1
- 7TMR
- AC-42
- ACPT-1
- AChE
- AD
- ADX71743
- AFQ056
- APP
- Allosteric modulator
- Alzheimer's disease
- BINA
- BQCA
- CDPPB
- CFMMC
- CNS
- CPPHA
- CTEP
- DA
- DFB
- DHPG
- Drug discovery
- ERK1/2
- FMRP
- FTIDC
- FXS
- Fragile X syndrome
- GABA
- GPCR
- JNJ16259685
- L-AP4
- L-DOPA
- Lu AF21934
- Lu AF32615
- M-5MPEP
- MMPIP
- MPEP
- MPTP
- MTEP
- Metabotropic glutamate receptor
- Muscarinic acetylcholine receptor
- N-[4-chloro-2[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]phenyl]-2-hydrobenzamide
- N-methyl-d-aspartate
- N-phenyl-7-(hydroxylimino)cyclopropa[b]chromen-1a-carboxamide
- NAM
- NMDA
- PAM
- PCP
- PD
- PD-LID
- PET
- PHCCC
- PQCA
- Parkinson's disease
- Parkinson's disease levodopa-induced dyskinesia
- SAM
- SIB-1757
- SIB-1893
- TBPB
- [(3-fluorophenyl)methylene]hydrazone-3-fluorobenzaldehyde
- acetylcholinesterase
- amyloid precursor protein
- benzylquinolone carboxylic acid
- central nervous system
- dihydroxyphenylglycine
- dopamine
- extracellular signal-regulated kinase 1/2
- fragile X mental retardation protein
- l-(+)-2-amino-4-phosphonobutyric acid
- l-3,4-dihydroxyphenylalanine
- mGlu
- metabotropic glutamate receptor
- negative allosteric modulator
- phencyclidine
- positive allosteric modulator
- positron emission tomography
- potassium 30-([(2-cyclopentyl-6-7-dimethyl-1-oxo-2,3-dihydro-1H-inden-5yl)oxy]methyl)biphenyl l-4-carboxylate
- seven transmembrane receptor
- silent allosteric modulator
- γ-aminobutyric acid
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Affiliation(s)
- Hilary Highfield Nickols
- Division of Neuropathology, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
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Kramvis I, Mansvelder HD, Loos M, Meredith R. Hyperactivity, perseveration and increased responding during attentional rule acquisition in the Fragile X mouse model. Front Behav Neurosci 2013; 7:172. [PMID: 24312033 PMCID: PMC3836024 DOI: 10.3389/fnbeh.2013.00172] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/05/2013] [Indexed: 01/09/2023] Open
Abstract
Attentional deficits and executive function impairments are common to many neurodevelopmental disorders of intellectual disability and autism, including Fragile X syndrome (FXS). In the knockout mouse model for FXS, significant changes in synaptic plasticity and connectivity are found in the prefrontal cortex (PFC)-a prominent region for attentional processing and executive control. Given these alterations in PFC synaptic function, we tested whether adult Fragile X knockout mice exhibited corresponding impairments in inhibitory control, perseveration, and sustained attention. Furthermore, we investigated individual performance during attentional rule acquisition. Using the 5-choice serial reaction time task, our results show no impairments in inhibitory control and sustained attention. Fragile X knockout mice exhibited enhanced levels of correct and incorrect responding, as well as perseveration of responding during initial phases of rule acquisition, that normalized with training. For both knockout and wild type mice, pharmacological attenuation of metabotropic glutamate receptor 5 signaling did not affect response accuracy but reduced impulsive responses and increased omission errors. Upon rule reversal, Fragile X knockout mice made more correct and incorrect responses, similar to the initial phases of rule acquisition. Analogous to heightened activity upon novel rule acquisition, Fragile X knockout mice were transiently hyperactive in both a novel open field (OF) arena and novel home cage. Hyperactivity ceased with familiarization to the environment. Our findings demonstrate normal inhibitory control and sustained attention but heightened perseveration, responding, and hyperactivity during novel rule acquisition and during exposure to novel environments in Fragile X knockout mice. We therefore provide evidence for subtle but significant differences in the processing of novel stimuli in the mouse model for the FXS.
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Affiliation(s)
- Ioannis Kramvis
- Department of Integrative Neurophysiology, Centre for Neurogenomics and Cognitive Research, VU University Amsterdam Amsterdam, Netherlands ; Sylics (Synaptologics BV) Amsterdam, Netherlands
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Akgün E, Javed MI, Lunzer MM, Smeester BA, Beitz AJ, Portoghese PS. Ligands that interact with putative MOR-mGluR5 heteromer in mice with inflammatory pain produce potent antinociception. Proc Natl Acad Sci U S A 2013; 110:11595-9. [PMID: 23798416 DOI: 10.1073/pnas.1305461110] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The low effectiveness of morphine and related mu opioid analgesics for the treatment of chronic inflammatory pain is a result of opioid-induced release of proinflammatory cytokines and glutamate that lower the pain threshold. In this regard, the use of opioids with metabotropic glutamate-5 receptor (mGluR5) antagonist has been reported to increase the efficacy of morphine and prevent the establishment of adverse effects during chronic use. Given the presence of opioid receptors (MORs) and mGluR5 in glia and neurons, together with reports that suggest coexpressed MOR/mGluR5 receptors in cultured cells associate as a heteromer, the possibility that such a heteromer could be a target in vivo was addressed by the design and synthesis of a series of bivalent ligands that contain mu opioid agonist and mGluR5 antagonist pharmacophores linked through spacers of varying length (10-24 atoms). The series was evaluated for antinociception using the tail-flick and von Frey assays in mice pretreated with lipopolysaccharide (LPS) or in mice with bone cancer. In LPS-pretreated mice, MMG22 (4c, 22-atom spacer) was the most potent member of the series (intrathecal ED50 ∼9 fmol per mouse), whereas in untreated mice its ED50 was more than three orders of magnitude higher. As members of the series with shorter or longer spacers have ≥500-fold higher ED50s in LPS-treated mice, the exceptional potency of MMG22 may be a result of the optimal bridging of protomers in a putative MOR-mGluR5 heteromer. The finding that MMG22 possesses a >10(6) therapeutic ratio suggests that it may be an excellent candidate for treatment of chronic, intractable pain via spinal administration.
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Morin N, Morissette M, Grégoire L, Gomez-Mancilla B, Gasparini F, Di Paolo T. Chronic treatment with MPEP, an mGlu5 receptor antagonist, normalizes basal ganglia glutamate neurotransmission in L-DOPA-treated parkinsonian monkeys. Neuropharmacology 2013; 73:216-31. [PMID: 23756168 DOI: 10.1016/j.neuropharm.2013.05.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 05/17/2013] [Accepted: 05/18/2013] [Indexed: 10/26/2022]
Abstract
Metabotropic glutamate 5 (mGlu5) receptor antagonists reduce L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias (LID) in Parkinson's disease (PD). The aim of this study was to investigate the long-term effect of the prototypal mGlu5 receptor antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) on glutamate receptors known to be involved in the development of LID in the de novo chronic treatment of monkeys lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP monkeys were treated for one month with L-DOPA and developed dyskinesias while those treated with L-DOPA and MPEP (10 mg/kg) developed significantly less. Normal control and saline-treated MPTP monkeys were also included. All MPTP monkeys were extensively and similarly denervated. The basal ganglia [(3)H]ABP688 specific binding (mGlu5 receptors) was elevated in L-DOPA-treated MPTP monkeys compared to controls but not in those treated with L-DOPA and MPEP; dyskinesia scores of these monkeys correlated positively with their [(3)H]ABP688 specific binding. Striatal density (B(max)) of [(3)H]ABP688 specific binding increased in L-DOPA-treated MPTP monkeys compared to other groups and affinity (Kd) remained unchanged. Striatal mGlu5 receptor mRNA remained unchanged following treatments. Elevated basal ganglia specific binding of [(3)H]Ro 25-6981 (NMDA NR1/NR2B receptors), [(3)H]Ro 48-8587 (AMPA receptors) but not [(3)H]CGP-39653 (NMDA NR1/NR2A receptors) was observed only in L-DOPA-treated MPTP monkeys; dyskinesias scores correlated with binding. By contrast, basal ganglia [(3)H]LY341495 specific binding (mGlu2/3 receptors) decreased in L-DOPA-treated MPTP monkeys compared to controls, saline and L-DOPA + MPEP treated MPTP monkeys; dyskinesias scores correlated negatively with this binding. Hence, chronic MPEP treatment reduces the development of LID and is associated with a normalization of glutamate neurotransmission.
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Affiliation(s)
- Nicolas Morin
- Neuroscience Research Unit, Laval University Medical Center (CHUQ), Quebec, QC, Canada
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Abstract
Fragile X syndrome (FXS) is a monogenic disorder that is caused by the absence of FMR1 protein (FMRP). FXS serves as an excellent model disorder for studies investigating disturbed molecular mechanisms and synapse function underlying cognitive impairment, autism, and behavioral disturbance. Abnormalities in dendritic spines and synaptic transmission in the brain of FXS individuals and mouse models for FXS indicate perturbations in the development, maintenance, and plasticity of neuronal network connectivity. However, numerous alterations are found during the early development in FXS, including abnormal differentiation of neural progenitors and impaired migration of newly born neurons. Several aspects of FMRP function are modulated by brain-derived neurotrophic factor (BDNF) signaling. Here, we review the evidence of the role for BDNF in the developing and adult FXS brain. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.
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Affiliation(s)
- Maija L Castrén
- Institute of Biomedicine/Physiology, University of Helsinki, P.O. Box 63, FIN-00014 Helsinki, Finland; Rinnekoti Foundation, Rinnekodintie 10, FIN-02980 Espoo, Finland.
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Downing C, Marks MJ, Larson C, Johnson TE. The metabotropic glutamate receptor subtype 5 mediates sensitivity to the sedative properties of ethanol. Pharmacogenet Genomics 2010; 20:553-64. [PMID: 20657349 DOI: 10.1097/FPC.0b013e32833d8c20] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Inbred long-sleep and short-sleep mice (ILS and ISS) were selectively bred for differential sensitivity to the sedative effects of ethanol. Lines of mice derived from these progenitors have been used to identify several quantitative trait loci (QTLs) mediating loss of the righting reflex due to ethanol (LORE). This study investigated the metabotropic glutamate receptor subtype 5 (mGluR5) as a candidate gene underlying Lore7, a QTL mediating differential LORE sensitivity. METHODS We used knockout mice, a quantitative complementation test, pharmacological antagonism of mGluR5, real-time quantitative PCR, radioligand binding, DNA sequencing, and bioinformatics to examine the role of mGluR5 in ethanol-induced sedation. RESULTS mGluR5 knockout mice had a significantly longer LORE duration than wildtype controls. Administration of the mGluR5 antagonist 2-methyl-6-(phenylethyl)-pyridine (MPEP) had differential effects on LORE in ILS and ISS mice. A quantitative complementation test also supported mGluR5 mediating LORE. Two intronic single-nucleotide polymorphisms in mGluR5 were highly correlated with LORE in recombinant inbred mice derived from a cross between ILS and ISS (LXS RIs). Differences in mGluR5 mRNA level and receptor density were observed between ILS and ISS in distinct brain regions. Finally, data from WebQTL showed that mGluR5 expression was highly correlated with several LORE phenotypes in the LXS RIs. CONCLUSION Altogether, this data provides convincing evidence that mGluR5 mediates differential sensitivity to the sedative effects of ethanol. Studies from the human literature have also identified mGluR5 as a potential candidate gene for ethanol sensitivity.
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