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Blakemore LJ, Trombley PQ. Zinc Modulates Olfactory Bulb Kainate Receptors. Neuroscience 2020; 428:252-268. [PMID: 31874243 DOI: 10.1016/j.neuroscience.2019.11.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 10/25/2022]
Abstract
Kainate receptors (KARs) are glutamate receptors with ionotropic and metabotropic activity composed of the GluK1-GluK5 subunits. We previously reported that KARs modulate excitatory and inhibitory transmission in the olfactory bulb (OB). Zinc, which is highly concentrated in the OB, also appears to modulate OB synaptic transmission via actions at other ionotropic glutamate receptors (i.e., AMPA, NMDA). However, few reports of effects of zinc on recombinant and/or native KARs exist and none have involved the OB. In the present study, we investigated the effects of exogenously applied zinc on OB KARs expressed by mitral/tufted (M/T) cells. We found that 100 µM zinc inhibits currents evoked by various combinations of KAR agonists (kainate or SYM 2081) and the AMPA receptor antagonist SYM 2206. The greatest degree of zinc-mediated inhibition was observed with coapplication of zinc with the GluK1- and GluK2-preferring agonist SYM 2081 plus SYM 2206. This finding is consistent with prior reports of zinc's inhibitory effects on some recombinant (homomeric GluK1 and GluK2 and heteromeric GluK2/GluK4 and GluK2/GluK5) KARs, although potentiation of other (GluK3, GluK2/3) KARs has also been described. It is also of potential importance given our previously reported molecular data suggesting that OB neurons express relatively high levels of GluK1 and GluK2. Our present findings suggest that a physiologically relevant concentration of zinc modulates KARs expressed by M/T cells. As M/T cells are targets of zinc-containing olfactory sensory neurons, synaptically released zinc may influence odor information-encoding synaptic circuits in the OB via actions at KARs.
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Affiliation(s)
- Laura J Blakemore
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA; Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Paul Q Trombley
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA; Department of Biological Science, Florida State University, Tallahassee, FL, USA.
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Poulie CBM, Alcaide A, Krell-Jørgensen M, Larsen Y, Astier E, Bjørn-Yoshimoto WE, Yi F, Syrenne JT, Storgaard M, Nielsen B, Frydenvang KA, Jensen AA, Hansen KB, Pickering DS, Bunch L. Design and Synthesis of 2,3- trans-Proline Analogues as Ligands for Ionotropic Glutamate Receptors and Excitatory Amino Acid Transporters. ACS Chem Neurosci 2019; 10:2989-3007. [PMID: 31124660 DOI: 10.1021/acschemneuro.9b00205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Development of pharmacological tools for the ionotropic glutamate receptors (iGluRs) is imperative for the study and understanding of the role and function of these receptors in the central nervous system. We report the synthesis of 18 analogues of (2 S,3 R)-2-carboxy-3-pyrrolidine acetic acid (3a), which explores the effect of introducing a substituent on the ε-carbon (3c-q). A new synthetic method was developed for the efficient synthesis of racemic 3a and applied to give expedited access to 13 racemic analogues of 3a. Pharmacological characterization was carried out at native iGluRs, cloned homomeric kainate receptors (GluK1-3), NMDA receptors (GluN1/GluN2A-D), and excitatory amino acid transporters (EAAT1-3). From the structure-activity relationship studies, several new ligands emerged, exemplified by triazole 3p-d1, GluK3-preferring (GluK1/GluK3 Ki ratio of 15), and the structurally closely related tetrazole 3q-s3-4 that displayed 4.4-100-fold preference as an antagonist for the GluN1/GluN2A receptor ( Ki = 0.61 μM) over GluN1/GluN2B-D ( Ki = 2.7-62 μM).
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Affiliation(s)
- Christian B. M. Poulie
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Anna Alcaide
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Mikkel Krell-Jørgensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Younes Larsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Eloi Astier
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Walden E. Bjørn-Yoshimoto
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, Center for Structural and Functional Neuroscience, and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Jed T. Syrenne
- Department of Biomedical and Pharmaceutical Sciences, Center for Structural and Functional Neuroscience, and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Morten Storgaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Birgitte Nielsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Karla A. Frydenvang
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Anders A. Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Kasper B. Hansen
- Department of Biomedical and Pharmaceutical Sciences, Center for Structural and Functional Neuroscience, and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Darryl S. Pickering
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Lennart Bunch
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
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Abstract
Unusual amino acids are fundamental building blocks of modern medicinal chemistry. The combination of readily functionalized amine and carboxyl groups attached to a chiral central core along with one or two potentially diverse side chains provides a unique three-dimensional structure with a high degree of functionality. This makes them invaluable as starting materials for syntheses of complex molecules, highly diverse elements for SAR campaigns, integral components of peptidomimetic drugs, and potential drugs on their own. This Perspective highlights the diversity of unnatural amino acid structures found in hit-to-lead and lead optimization campaigns and clinical stage and approved drugs, reflecting their increasingly important role in medicinal chemistry.
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Affiliation(s)
- Mark A T Blaskovich
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland Australia 4072
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Zhai Y, Zhao X, Cui Z, Wang M, Wang Y, Li L, Sun Q, Yang X, Zeng D, Liu Y, Sun Y, Lou Z, Shang L, Yin Z. Cyanohydrin as an Anchoring Group for Potent and Selective Inhibitors of Enterovirus 71 3C Protease. J Med Chem 2015; 58:9414-20. [PMID: 26571192 DOI: 10.1021/acs.jmedchem.5b01013] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cyanohydrin derivatives as enterovirus 71 (EV71) 3C protease (3C(pro)) inhibitors have been synthesized and assayed for their biochemical and antiviral activities. Compared with the reported inhibitors, cyanohydrins (1S,2S,2'S,5S)-16 and (1R,2S,2'S,5S)-16 exhibited significantly improved activity and attractive selectivity profiles against other proteases, which were a result of the specific interactions between the cyanohydrin moiety and the catalytic site of 3C(pro). Cyanohydrin as an anchoring group with high selectivity and excellent inhibitory activity represents a useful choice for cysteine protease inhibitors.
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Affiliation(s)
- Yangyang Zhai
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Xiangshuai Zhao
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Zhengjie Cui
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Man Wang
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Yaxin Wang
- Laboratory of Structural Biological & Ministry of Education (MOE), and Laboratory of Protein Science, School of Medicine and Life Sciences, Tsinghua University , Beijing 100084, China
| | - Linfeng Li
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Qi Sun
- College of Chemistry, and Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, Central China Normal University , Wuhan 430079, China
| | - Xi Yang
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Debin Zeng
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Ying Liu
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Yuna Sun
- National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Science , Beijing 100101, China
| | - Zhiyong Lou
- Laboratory of Structural Biological & Ministry of Education (MOE), and Laboratory of Protein Science, School of Medicine and Life Sciences, Tsinghua University , Beijing 100084, China
| | - Luqing Shang
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
| | - Zheng Yin
- College of Pharmacy and State Key Laboratory of Elemento-Organic Chemistry, Nankai University , 94 Weijin Road, Nankai District, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
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Mollica A, Stefanucci A, Costante R, Novellino E. Pyroglutamic Acid Derivatives: Building Blocks for Drug Discovery. HETEROCYCLES 2014. [DOI: 10.3987/rev-14-800] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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6
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Rasmussen JL, Storgaard M, Pickering DS, Bunch L. Rational design, synthesis and pharmacological evaluation of the (2R)- and (2S)-stereoisomers of 3-(2-carboxypyrrolidinyl)-2-methyl acetic acid as ligands for the ionotropic glutamate receptors. ChemMedChem 2011; 6:498-504. [PMID: 21268287 DOI: 10.1002/cmdc.201000543] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Indexed: 12/16/2023]
Abstract
In this paper we describe the rational design, synthesis and pharmacological evaluation of two new stereoisomeric (S)-glutamate (Glu) analogues. The rational design was based on hybrid structures of the natural product kainic acid, a synthetic analogue CPAA and the high-affinity Glu analogue SYM2081. Pharmacological evaluation of the two stereoisomers revealed that one stereoisomer showed a subtype selectivity profile with low micromolar affinity for GluK1 and GluK3 and a 10- to 15-fold lower affinity for GluK2. The other stereoisomer displayed full selectivity for the KA over AMPA and NMDA receptors (GluK1-3: 0.39, 0.51 and 0.099 µM, respectively).
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Affiliation(s)
- Julie L Rasmussen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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Effect of inhibition of spinal cord glutamate transporters on inflammatory pain induced by formalin and complete Freund's adjuvant. Anesthesiology 2011; 114:412-23. [PMID: 21245732 DOI: 10.1097/aln.0b013e318205df50] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Spinal cord glutamate transporters clear synaptically released glutamate and maintain normal sensory transmission. However, their ultrastructural localization is unknown. Moreover, whether and how they participate in inflammatory pain has not been carefully studied. METHODS Immunogold labeling with electron microscopy was carried out to characterize synaptic and nonsynaptic localization of glutamate transporters in the superficial dorsal horn. Their expression and uptake activity after formalin- and complete Freund's adjuvant (CFA)-induced inflammation were evaluated by Western blot analysis and glutamate uptake assay. Effects of intrathecal glutamate transporter activator (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline and inhibitors (DL-threo-β-benzyloxyaspartate [TBOA], dihydrokainate, and DL-threo-β-hydroxyaspartate), or TBOA plus group III metabotropic glutamate receptor antagonist (RS)-α-methylserine-O-phosphate, on formalin- and CFA-induced inflammatory pain were examined. RESULTS In the superficial dorsal horn, excitatory amino acid carrier 1 is localized in presynaptic membrane, postsynaptic membrane, and axonal and dendritic membranes at nonsynaptic sites, whereas glutamate transporter-1 and glutamate/aspartate transporter are prominent in glial membranes. Although expression of these three spinal glutamate transporters was not altered 1 h after formalin injection or 6 h after CFA injection, glutamate uptake activity was decreased at these time points. Intrathecal (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline had no effect on formalin-induced pain behaviors. In contrast, intrathecal TBOA, dihydrokainate, and DL-threo-β-hydroxyaspartate reduced formalin-evoked pain behaviors in the second phase. Intrathecal TBOA also attenuated CFA-induced thermal hyperalgesia at 6 h after CFA injection. The antinociceptive effects of TBOA were blocked by coadministration of (RS)-α-methylserine-O-phosphate. CONCLUSION Our findings suggest that spinal glutamate transporter inhibition relieves inflammatory pain through activation of inhibitory presynaptic group III metabotropic glutamate receptors.
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Bunch L, Pickering DS, Gefflaut T, Vinatier V, Helaine V, Amir A, Nielsen B, Jensen AA. 4,4-Dimethyl- and diastereomeric 4-hydroxy-4-methyl- (2S)-glutamate analogues display distinct pharmacological profiles at ionotropic glutamate receptors and excitatory amino acid transporters. ChemMedChem 2010; 4:1925-9. [PMID: 19731281 DOI: 10.1002/cmdc.200900258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Subtype-selective ligands are of great interest to the scientific community, as they provide a tool for investigating the function of one receptor or transporter subtype when functioning in its native environment. Several 4-substituted (S)-glutamate (Glu) analogues were synthesized, and altogether this approach has provided important insight into the structure-activity relationships (SAR) for ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), as well as the excitatory amino acid transporters (EAATs). In this work, three 4,4-disubstituted Glu analogues 1-3, which are hybrid structures of important 4-substituted Glu analogues 4-8, were investigated at iGluRs and EAATs. Collectively, their pharmacological profiles add new and valuable information to the SAR for the iGluRs and EAAT1-3.
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Affiliation(s)
- Lennart Bunch
- Department of Medicinal Chemistry, University of Copenhagen, Denmark.
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9
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Bunch L, Gefflaut T, Alaux S, Sagot E, Nielsen B, Pickering DS. Pharmacological characterization of (4R)-alkyl glutamate analogues at the ionotropic glutamate receptors — Focus on subtypes iGlu5–7. Eur J Pharmacol 2009; 609:1-4. [DOI: 10.1016/j.ejphar.2009.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 02/26/2009] [Accepted: 03/03/2009] [Indexed: 10/21/2022]
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10
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Bunch L, Krogsgaard-Larsen P. Subtype selective kainic acid receptor agonists: Discovery and approaches to rational design. Med Res Rev 2009; 29:3-28. [DOI: 10.1002/med.20133] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Oba M, Mita A, Kondo Y, Nishiyama K. Facile Synthesis of 3‐Hydroxyglutamic Acids via Cyanation of Chiral N‐Acyliminium Cation Derived From (S)‐Malic Acid. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397910500278446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Makoto Oba
- a Department of Materials Chemistry , Tokai University , Shizuoka , Japan
| | - Atsushi Mita
- a Department of Materials Chemistry , Tokai University , Shizuoka , Japan
| | - Yoshinori Kondo
- a Department of Materials Chemistry , Tokai University , Shizuoka , Japan
| | - Kozaburo Nishiyama
- a Department of Materials Chemistry , Tokai University , Shizuoka , Japan
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Dumitrescu ON, Protti DA, Majumdar S, Zeilhofer HU, Wässle H. Ionotropic glutamate receptors of amacrine cells of the mouse retina. Vis Neurosci 2006; 23:79-90. [PMID: 16597352 DOI: 10.1017/s0952523806231079] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2005] [Accepted: 09/15/2005] [Indexed: 11/06/2022]
Abstract
The mammalian retina contains approximately 30 different morphological types of amacrine cells, receiving glutamatergic input from bipolar cells. In this study, we combined electrophysiological and pharmacological techniques in order to study the glutamate receptors expressed by different types of amacrine cells. Whole-cell currents were recorded from amacrine cells in vertical slices of the mouse retina. During the recordings the cells were filled with Lucifer Yellow/Neurobiotin allowing classification as wide-field or narrow-field amacrine cells. Amacrine cell recordings were also carried out in a transgenic mouse line whose glycinergic amacrine cells express enhanced green fluorescent protein (EGFP). Agonist-induced currents were elicited by exogenous application of NMDA, AMPA, and kainate (KA) while holding cells at −75 mV. Using a variety of specific agonists and antagonists (NBQX, AP5, cyclothiazide, GYKI 52466, GYKI 53655, SYM 2081) responses mediated by AMPA, KA, and NMDA receptors could be dissected. All cells (n= 300) showed prominent responses to non-NMDA agonists. Some cells expressed AMPA receptors exclusively and some cells expressed KA receptors exclusively. In the majority of cells both receptor types could be identified. NMDA receptors were observed in about 75% of the wide-field amacrine cells and in less than half of the narrow-field amacrine cells. Our results confirm that different amacrine cell types express distinct sets of ionotropic glutamate receptors, which may be critical in conferring their unique temporal responses to this diverse neuronal class.
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Affiliation(s)
- Olivia N Dumitrescu
- Department of Neuroanatomy, Max-Planck-Institute for Brain Research, Frankfurt/Main, Germany
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Wehbe J, Rolland V, Fruchier A, Roumestant ML, Martinez J. Enantioselective synthesis of new 4-substituted glutamic acid derivatives. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.tetasy.2004.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Turner MS, Hamamoto DT, Hodges JS, Maccecchini ML, Simone DA. SYM 2081, an agonist that desensitizes kainate receptors, attenuates capsaicin and inflammatory hyperalgesia. Brain Res 2003; 973:252-64. [PMID: 12738069 DOI: 10.1016/s0006-8993(03)02525-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Excitatory amino acids acting at non-NMDA receptors contribute to transmission of nociceptive information. SYM 2081 ((2S,4R)-4-methyl glutamic acid) desensitizes kainate receptors, one subtype of non-NMDA receptors, to subsequent release of excitatory amino acids and thus may attenuate transmission of nociceptive information. To determine if SYM 2081 can prevent development of hyperalgesia, SYM 2081 (10, 50 or 100 mg/kg, i.p.) was administered prior to injection of capsaicin into the hindpaw of rats, which produces mechanical and heat hyperalgesia. To determine if SYM 2081 can reduce ongoing inflammatory hyperalgesia, SYM 2081 (10 or 100 mg/kg, i.p.) was administered after development of carrageenan-evoked hyperalgesia. Intraplantar injection of capsaicin produced an increase in hindpaw withdrawal frequency to mechanical stimuli (from 4+/-2 to 41+/-7%; mean+/-S.E.M.) and a decrease in withdrawal latency to heat (from 12.3+/-0.3 to 5.9+/-0.4 s) in rats that received vehicle. In contrast, rats that received SYM 2081 (100 mg/kg) prior to injection of capsaicin exhibited a lower hindpaw withdrawal frequency (18+/-4%) and a longer withdrawal latency (7.7+/-0.5 s). Intrathecal (1-100 microg/5 microl), but not intraplantar (10 or 100 microg/50 microl), injection of SYM 2081 attenuated the development of capsaicin-evoked heat hyperalgesia suggesting that SYM 2081's antihyperalgesic effects were due to its central effects. Furthermore, SYM 2081 completely reversed ongoing carrageenan-evoked mechanical hyperalgesia and partially (approximately 50%) reversed ongoing heat hyperalgesia. The present study demonstrates that administration of a high-potency ligand that selectively desensitizes kainate receptors attenuates the development of mechanical and heat hyperalgesia and attenuates ongoing inflammatory hyperalgesia.
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Affiliation(s)
- Michelle S Turner
- Department of Oral Science, University of Minnesota, 17-252 Moos Tower, 515 Delaware Street S.E., Minneapolis, MN 55455, USA
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17
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Cristóvão AJ, Carvalho CM. Development of chick retina cells in culture: cobalt entry through AMPA receptors and expression of GluR4 AMPA receptor subunit. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2003; 140:75-84. [PMID: 12524178 DOI: 10.1016/s0165-3806(02)00580-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The functionality of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors in chick embryo retina cells during development in vitro was studied by using Co(2+) uptake, and these data were correlated with the expression of the AMPA receptor subunit GluR4. We found that at 5 h in vitro only a small number of cells took up Co(2+) upon stimulation with 100 microM kainate or other AMPA receptor agonists, in the presence of cyclothiazide (CTZ), to inhibit desensitisation. The number of cells sensitive to kainate increased from 5 h in vitro to 3 days in vitro (DIV), and remained relatively constant until 14 DIV. When the cells were stimulated with (2S,4S)-4-methylglutamic acid (30 microM), a specific kainate receptor agonist, after inhibiting desensitisation with concanavalin A, we did not observe an increase in the number of cells responding, as compared to the control. The expression of the AMPA receptor subunit GluR4 during development was detected by immunofluorescence mainly at the perinuclear region of the cells, and the number of positive cells increased from 5 h in vitro to 7 DIV, and remained relatively constant until 14 DIV. The results suggest that AMPA receptors can be functionally active at early embryonic stages (5 h in vitro) in cultured retinal neurons, although in only a few cells, before synapse formation (E12). The localisation of GluR4 was well correlated with Co(2+) entry, since the strongest GluR4 immunoreactivity was found in the regions that showed the most intense labelling with Co(2+). Finally, we found that the expression levels of GluR4 at the neurites increased between 5 h in vitro and 7 DIV, near the period of synapse formation.
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Affiliation(s)
- Armando J Cristóvão
- Center for Neuroscience of Coimbra, Department of Zoology, University of Coimbra, Coimbra, Portugal
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Yan Z, Weaving R, Dauban P, Dodd RH. Enantiospecific synthesis of 3,4-disubstituted glutamic acids via controlled stepwise ring-opening of 2,3-aziridino-γ-lactone. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01762-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ruscheweyh R, Sandkühler J. Role of kainate receptors in nociception. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2002; 40:215-22. [PMID: 12589919 DOI: 10.1016/s0165-0173(02)00203-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nociceptive nerve fibers use L-glutamate as a fast excitatory neurotransmitter and it is therefore not surprising that both, ionotropic and metabotropic glutamate receptors play pivotal roles for transmission of nociceptive information in spinal cord. A subtype of ionotropic glutamate receptors, the kainate receptor, is present in spinal dorsal horn. However, its role has remained obscure as specific antagonists and agonists have become available only recently. Kainate receptors are present on small, including nociceptive, dorsal root ganglion cells and on intrinsic dorsal horn neurons, and those two locations can be targeted separately by appropriate agonists and antagonists. Postsynaptic kainate receptors on spinal dorsal horn neurons are activated by high intensity electrical stimulation of the dorsal root entry zone that activates nociceptive primary afferent fibers. In contrast, low intensity stimulation that activates only non-nociceptive fibers is ineffective. Selective blockade of kainate receptors may produce analgesia. Here, we review what is known about localization of kainate receptors in dorsal root ganglia and spinal dorsal horn and their physiological and pathophysiological importance with special reference to nociceptive pathways. A short overview on molecular biology and agonist and antagonist pharmacology is included.
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Affiliation(s)
- Ruth Ruscheweyh
- Cellular and Integrative Neurophysiology, Brain Research Institute, Vienna University Medical School, Spitalgasse 4, A-1090, Vienna, Austria
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Guldbrandt M, Johansen TN, Frydenvang K, Bräuner-Osborne H, Stensbøl TB, Nielsen B, Karla R, Santi F, Krogsgaard-Larsen P, Madsen U. Glutamate receptor ligands: synthesis, stereochemistry, and enantiopharmacology of methylated 2-aminoadipic acid analogs. Chirality 2002; 14:351-63. [PMID: 11968078 DOI: 10.1002/chir.10104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Homologation and substitution on the carbon backbone of (S)-glutamic acid [(S)-Glu, 1], as well as absolute stereochemistry, are structural parameters of key importance for the pharmacological profile of (S)-Glu receptor ligands. We describe a series of methyl-substituted 2-aminoadipic acid (AA) analogs, and the synthesis, stereochemistry, and enantiopharmacology of 3-methyl-AA (4a-d), 4-methyl-AA (5a-d), 5-methyl-AA (6a-d), and (E)-Delta(4)-5-methyl-AA (7a and 7b) are reported. The compounds were resolved using chiral HPLC and the configurational assignments of the enantiomers were based on X-ray crystallographic analyses, chemical correlation, and CD spectral analyses. The effects of the individual stereoisomers at ionotropic and metabotropic (S)-Glu receptors (iGluRs and mGluRs) were characterized. Compounds with S-configuration at the alpha-carbon generally showed mGluR2 agonist activity of similar or slightly lower potencies than (S)-AA [e.g., EC(50) = 76 microM for (2S,4S)-4-methyl-AA (5a) as compared to EC(50) = 35 microM for (S)-AA]. The position of the methyl substituent had a profound effect on the observed pharmacology, whereas the absolute stereochemistry at the methylated carbon atom had a very limited effect on pharmacology. Structure-activity relationships at iGluRs in the rat cortical wedge preparation showed a complex pattern, some compounds being NMDA receptor agonists [e.g., EC(50) =110 microM for (2S,5RS)-5-methyl-AA (6a,b)] and some compounds showing NMDA receptor antagonist effects [e.g., IC(50) = 300 microM for (2R,4S)-4-methyl-AA (5d)]. The two unsaturated analogs (S)- (7a) and (R)-(E)-Delta(4)-5-methyl-AA (7b) turned out to be a weak AMPA receptor agonist and a weak mixed NMDA/AMPA receptor antagonist, respectively.
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Affiliation(s)
- Mette Guldbrandt
- Center for Drug Design and Transport, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Copenhagen, Denmark
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22
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Bailey A, Kelland EE, Thomas A, Biggs J, Crawford D, Kitchen I, Toms NJ. Regional mapping of low-affinity kainate receptors in mouse brain using [(3)H](2S,4R)-4-methylglutamate autoradiography. Eur J Pharmacol 2001; 431:305-10. [PMID: 11730722 DOI: 10.1016/s0014-2999(01)01463-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent data indicate that (2S,4R)-4-methylglutamate is a selective agonist for low affinity (GluR5 and GluR6) kainate receptor subunits. In the present study, we have employed [(3)H](2S,4R)-4-methylglutamate to examine low affinity kainate receptor distribution in mouse brain. [(3)H](2S,4R)-4-Methylglutamate labelled a single site in murine cerebrocortical membranes (K(d)=9.9+/-2.7 nM, B(max)=296.3+/-27.1 fmol mg protein(-1)). The binding of 8 nM [(3)H](2S,4R)-4-methylglutamate was displaced by several non-NMDA receptor ligands (K(i)+/-S.E.M.): domoate (1.1+/-0.2 nM)>kainate (7.1+/-1.1 nM) >> L-glutamate (187.6+/-31.9 nM) >> (S)-alpha-amino-3-hydroxy-5-methyl-4-isoazolepropionic acid (AMPA) (>50 microM). [(3)H](2S,4R)-4-Methylglutamate autoradiography revealed a widespread regional distribution of low affinity kainate receptors. Highest binding densities occurred within deep layers of the cerebral cortex, olfactory bulb, basolateral amygdala and hippocampal CA3 subregion. Moderate labelling was also evident in the nucleus accumbens, dentate gyrus, caudate putamen, hypothalamus and cerebellar granule cell layer. These data show that [(3)H](2S,4R)-4-methylglutamate is a useful radioligand for selectively labelling low affinity kainate receptors.
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Affiliation(s)
- A Bailey
- School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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23
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Kabat MM. Radical reaction of Williams’ glycinate auxiliaries with α-amidoacrylates: synthesis of orthogonally functionalized (2R,4R)- and (2R,4S)-diaminoglutamic acids. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01600-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Lerma J, Paternain AV, Rodríguez-Moreno A, López-García JC. Molecular physiology of kainate receptors. Physiol Rev 2001; 81:971-98. [PMID: 11427689 DOI: 10.1152/physrev.2001.81.3.971] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
A decade ago, our understanding of the molecular properties of kainate receptors and their involvement in synaptic physiology was essentially null. A plethora of recent studies has altered this situation profoundly such that kainate receptors are now regarded as key players in the modulation of transmitter release, as important mediators of the postsynaptic actions of glutamate, and as possible targets for the development of antiepileptic and analgesic drugs. In this review, we summarize our current knowledge of the properties of kainate receptors focusing on four key issues: 1) their structural and biophysical features, 2) the important progress in their pharmacological characterization, 3) their pre- and postsynaptic mechanisms of action, and 4) their involvement in a series of physiological and pathological processes. Finally, although significant progress has been made toward the elucidation of their importance for brain function, kainate receptors remain largely an enigma and, therefore, we propose some new roads that should be explored to obtain a deeper understanding of this young, but intriguing, class of proteins.
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Affiliation(s)
- J Lerma
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
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25
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Bunch L, Johansen TH, Bräuner-Osborne H, Stensbøl TB, Johansen TN, Krogsgaard-Larsen P, Madsen U. Synthesis and receptor binding affinity of new selective GluR5 ligands. Bioorg Med Chem 2001; 9:875-9. [PMID: 11354670 DOI: 10.1016/s0968-0896(00)00304-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two hybrid analogues of the kainic acid receptor agonists, 2-amino-3-(5-tert-butyl-3-hydroxy-4-isoxazolyl)propionic acid (ATPA) and (2S,4R)-4-methylglutamic acid ((2S,4R)-4-Me-Glu), were designed, synthesized, and characterized in radioligand binding assays using cloned ionotropic and metabotropic glutamic acid receptors. The (S)-enantiomers of E-4-(2,2-dimethylpropylidene)glutamic acid ((S)-1) and E-4-(3,3-dimethylbutylidene)glutamic acid ((S)-2) were shown to be selective and high affinity GluR5 ligands, with Ki values of 0.024 and 0.39 microM, respectively, compared to Ki values at GluR2 of 3.0 and 2.0 microM. respectively. Their affinities in the [3H]AMPA binding assay on native cortical receptors were shown to correlate with their GluR2 affinity rather than their GluR5 affinity. No affinity for GluR6 was detected (IC50 > 100 microM).
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Affiliation(s)
- L Bunch
- Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Universitetsparken 2, Copenhagen
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26
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Stereoselective synthesis of protected threo-β-hydroxy-l-glutamic acid using a chiral aziridine. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0957-4166(00)00311-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Phillis JW, Ren J, O'Regan MH. Transporter reversal as a mechanism of glutamate release from the ischemic rat cerebral cortex: studies with DL-threo-beta-benzyloxyaspartate. Brain Res 2000; 868:105-12. [PMID: 10841893 DOI: 10.1016/s0006-8993(00)02303-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Elevated levels of the excitotoxic amino acids, glutamate and aspartate, have been implicated in the pathogenesis of neuronal injury and death induced by cerebral ischemia. This study evaluated the contribution of reversed high-affinity, Na(+)-dependent, glutamate transport to the ischemia-evoked release of glutamate and aspartate using DL-threo-beta-benzyloxyaspartate (DL-TBOA), a newly developed competitive, non-transported blocker of the EAAT 1-3 transporters. Changes in the extracellular levels of these and other amino acids, and of glucose and lactate in cerebral cortical superfusates during four-vessel occlusion-elicited global cerebral ischemia were examined using a cortical window technique. Basal and ischemia-evoked amino acid, glucose and lactate efflux were compared in control versus DL-TBOA (100 microM; applied topically for 35 min prior to ischemia) animals. Twenty minutes of ischemia caused large increases in aspartate, glutamate, GABA and taurine effluxes into cortical superfusates, with non-significant effects on the efflux of glycine, glutamine, alanine and serine. Application of DL-TBOA caused a 2-fold increase in basal, preischemic, extracellular glutamate levels, but did not affect those of the other compounds. In the presence of DL-TBOA, ischemia-evoked release of aspartate, glutamate, taurine and glutamine was significantly reduced; that of the other amino acids was not affected. The ischemia-evoked declines in glucose were significantly attenuated, and lactate release was enhanced above that in control animals. The amino acid data are interpreted as indicating that aspartate and glutamate releases were reduced as a consequence of DL-TBOA inhibition of reversed transport by high-affinity, Na-dependent carriers, predominantly involving the glial EAAT 2 transporter. The reduction in ischemia-evoked taurine release is interpreted as being due to a decrease in cell swelling prior to and during the initial phase of ischemia due to reduced entry of the Na(+), and other ions, associated with a decreased glutamate uptake. Glucose-sparing and availability for lactate formation would also result from a reduced glutamate/Na(+) uptake. These results indicate that reversed transport, primarily from glial cells by the EAAT 2 carrier, is responsible for a substantial (42 and 56%) portion of the ischemia-evoked increase in extracellular glutamate and aspartate levels, respectively. As a potent, competitive, non-transported blocker of high-affinity, Na(+)-dependent, glutamate transporters, DL-TBOA promises to be a valuable new compound for the study of glutamatergic mechanisms.
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Affiliation(s)
- J W Phillis
- Department of Physiology, School of Medicine, 5374 Scott Hall, Wayne State University, 540 E. Canfield, Detroit, MI 48201, USA.
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28
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Lieb I, Chebib M, Cooper B, Dias LS, Balcar VJ. Quantitative autoradiography of Na+-dependent [3H]L-aspartate binding to L-glutamate transporters in rat brain: structure-activity studies using L-trans-pyrrolidine-2,4-dicarboxylate (L-t-PDC) and 2-(carboxycyclopropyl)-glycine (CCG). Neurochem Int 2000; 36:319-27. [PMID: 10732999 DOI: 10.1016/s0197-0186(99)00140-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sodium-dependent binding of [3H]L-aspartate was studied in thaw-mounted horizontal sections of fresh-frozen (i.e. not fixed) rat brain. After the incubation with [3H]L-aspartate, the sections were exposed against a 3H-sensitive film and the resulting autoradiograms were evaluated by quantitative densitometry. Effects of several inhibitors were examined and their potency expressed as IC50 and nH. Together with previously published data, the present study supports the view that [3H]L-aspartate binding to fresh-frozen sections of rat brain represents interaction of the radioligand with the substrate-binding sites on glutamate transporters. The most potent inhibitors were (2S,3S,4R)-2-(carboxycyclopropyl)-glycine (L-CCG III) and (2S,4R)-4-methylglutamate. In contrast, L-anti,endo-3,4-methanopyrrolidine dicarboxylate (L-a,e-MPDC) was about an order of magnitude less potent. Only subtle regional variations in the characteristics of inhibitors of [3H]L-aspartate binding were detected. It is not certain whether these differences reflect regional variations in the distribution of individual glutamate transporters or regional peculiarities in their pharmacological characteristics. In particular, (2S,4R)-4-methylglutamate, shown previously to differentiate between GLT-1 (principal glutamate transporter in the forebrain) and GLAST (expressed mainly in the cerebellum), did not strongly differentiate between the binding of [3H]L-aspartate in forebrain and cerebellum. Computer-assisted molecular modelling using selected glutamate analogues with restricted conformation (L-trans-pyrrolidine-2,4-dicarboxylate and four isomers of 2-(carboxycyclopropyl)-glycine: L- and D-CCG I, L-CCG III and L-CCG IV) identified at least one area of unfavourable steric interaction. We conclude that the quantitative autoradiographic studies using [3H]L-aspartate or other transporter-specific ligands, will be a useful tool to study the pharmacology of substrate binding sites on glutamate transporters in the mammalian brain in situ.
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Affiliation(s)
- I Lieb
- Department of Anatomy and Histology, The University of Sydney, NSW, Australia
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29
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Dauban P, de Saint-Fuscien C, Acher F, Prézeau L, Brabet I, Pin JP, Dodd RH. First enantiospecific synthesis of a 3,4-dihydroxy-L-glutamic acid [(3S,4S)-DHGA], a new mGluR1 agonist. Bioorg Med Chem Lett 2000; 10:129-33. [PMID: 10673095 DOI: 10.1016/s0960-894x(99)00641-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The first synthesis of one of the 4 possible stereoisomers of 3,4-dihydroxy-L-glutamic acid ((3S,4S)-DHGA 3), a natural product of unknown configuration, is described. The synthesis is based on the Lewis acid catalyzed reaction of benzyl alcohol with a D-ribose-derived 2,3-aziridino-gamma-lactone 4-benzyl carboxylate (6). Preliminary pharmacological studies showed that (3S,4S)-3 is an agonist of metabotropic glutamate receptors of type 1 (mGluR1) and a weak antagonist of mGluR4 but has no discernible activity with respect to mGluR2. This activity profile can be rationalized by fitting extended conformations of (3S,4S)-3 in proposed models of each of these receptor subtypes.
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Affiliation(s)
- P Dauban
- Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France
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30
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Helaine V, Bolte J. Chemoenzymatic Synthesis of (4S)- and (4R)-4-Methyl-2-oxoglutaric Acids, Precursors of Glutamic Acid Analogues. European J Org Chem 1999. [DOI: 10.1002/(sici)1099-0690(199912)1999:12<3403::aid-ejoc3403>3.0.co;2-u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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32
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Hoo K, Legutko B, Rizkalla G, Deverill M, Hawes CR, Ellis GJ, Stensbol TB, Krogsgaard-Larsen P, Skolnick P, Bleakman D. [3H]ATPA: a high affinity ligand for GluR5 kainate receptors. Neuropharmacology 1999; 38:1811-7. [PMID: 10608276 DOI: 10.1016/s0028-3908(99)00133-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The pharmacological properties of [3H]ATPA ((RS)-2-amino-3(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid) are described. ATPA is a tert-butyl analogue of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid) that has been shown to possess high affinity for the GluR5 subunit of kainate receptors. [3H]ATPA exhibits saturable, high affinity binding to membranes expressing human GluR5 (GluR5) kainate receptors (Kd approximately 13 nM). No specific binding was observed in membranes expressing GluR2 and GluR6 receptors. Several compounds known to interact with the GluR5 kainate receptor inhibited [3H]ATPA binding with potencies similar to those obtained for competition of [3H]kainate binding to GluR5. Saturable, high affinity [3H]ATPA binding (Kd approximately 4 nM) was also observed in DRG neuron (DRG) membranes isolated from neonatal rats. The rank order potency of compounds to inhibit [3H]ATPA binding in rat DRG and GluR5 membranes were in agreement. These finding demonstrate that [3H]ATPA can be used as a radioligand to examine the pharmacological properties of GluR5 containing kainate receptors.
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Affiliation(s)
- K Hoo
- Allelix Biopharmaceuticals, Mississauga, Ont., Canada
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33
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Helaine V, Rossi J, Bolte J. A new access to alkyl-α-ketoglutaric acids, precursors of glutamic acid analogues by enzymatic transamination. Application to the synthesis of (2S,4R)-4-propyl-glutamic acid. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01302-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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34
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Bleakman D, Ogden AM, Ornstein PL, Hoo K. Pharmacological characterization of a GluR6 kainate receptor in cultured hippocampal neurons. Eur J Pharmacol 1999; 378:331-7. [PMID: 10493110 DOI: 10.1016/s0014-2999(99)00478-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have examined the pharmacology of kainate receptors in cultured hippocampal neurons (6-8 days in vitro (DIV)) from embryonic rats (E17). Cultured neurons were pre-treated with concanavalin A to remove kainate receptor desensitization and whole-cell voltage clamp electrophysiology employed to record inward currents in response to glutamatergic agonists and antagonists. N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptor responses were blocked using MK801 (3 microM) and the 2,3-benzodiazepine, LY300168 (GYKI53655, 50 microM), respectively. Inward currents were recorded in hippocampal neurons upon application of kainate and the 2S,4R isomer of 4-methyl glutamic acid (SYM2081) with EC50 values of 3.4 +/- 0.4 microM and 1.6 +/- 0.5 microM, respectively (n = 6 cells). The GluR5 selective agonists, LY339434 (100 microM) and (RS)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl) propionic acid (ATPA) (100 microM), did not evoke detectable inward currents in any cell responding to kainate. LY293558 and the selective GluR5 antagonist, LY382884, had weak antagonist effects on responses evoked by either kainate or (2S,4R)-4-methyl glutamate (IC50 > 300 microM). The quinoxalinedione, 2,3-dihyro-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX), blocked both kainate and (2S,4R)-4-methyl glutamate-activated currents at much lower concentrations (IC50 approximately 10 microM). These results provide pharmacological evidence that ion channels comprised of GluR6 kainate receptor subunits mediate kainate receptor responses in hippocampal neurons cultured 6-8 DIV.
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Affiliation(s)
- D Bleakman
- Eli Lilly and Company, Lilly Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285-0510, USA.
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35
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Cunha RA, Malva JO, Ribeiro JA. Kainate receptors coupled to G(i)/G(o) proteins in the rat hippocampus. Mol Pharmacol 1999; 56:429-33. [PMID: 10419564 DOI: 10.1124/mol.56.2.429] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kainate receptors are a subtype of ionotropic glutamate receptors, permeable to cations and thus expected to have an excitatory depolarizing action on neurons. However, kainate receptor activation inhibits gamma-aminobutyric acid release in the hippocampus through activation of protein kinase C in a pertussis toxin-dependent manner, suggesting a coupling of kainate receptors to G proteins. Thus, we directly investigated the G protein coupling of kainate receptors in the rat hippocampus by using a selective kainate receptor agonist, [(3)H](2S,4R)-4-methylglutamate ([(3)H]MGA). [(3)H]MGA bound to a single site to hippocampal membranes with a K(D) value of 32 nM and a B(max) value of 1024 fmol/mg protein. This binding likely represents kainate receptors because it was displaced by domoate (K(i) = 4 nM), kainate (K(i) = 11 nM), and 6-cyano-7-nitroquinoxaline-2,3-dione (K(i) = 1.4 microM), but not by alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (K(i) > 10 microM), (RS)-alpha-methyl-4-phosphonophenylglycine (K(i) > 10 microM), or (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (K(i) > 10 microM). Guanylylimidodiphosphate (30 microM), which uncouples all G protein-coupled receptors, shifted to the right the saturation curve of [(3)H]MGA (K(D) = 133 nM). This effect was mimicked by pretreatment of hippocampal membranes with modifiers of G(i)/G(o) proteins [30 microM N-ethylmaleimide (K(D) = 98 nM) or 25 microgram/ml pertussis toxin (K(D) = 95 nM)] but not by a modifier of G(s) proteins [50 microgram/ml cholera toxin (K(D) = 32 nM)]. Treatment of solubilized hippocampal membranes with pertussis toxin (25 microgram/ml) decreased [(3)H]MGA affinity (K(D) = 105-113 nM), which was recovered by reconstitution of these pretreated solubilized hippocampal membranes with G(i)/G(o) proteins (K(D) = 41-76 nM). These results indicate that hippocampal kainate receptors are coupled to G(i)/G(o) proteins.
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Affiliation(s)
- R A Cunha
- Laboratory of Neurosciences, Faculty of Medicine, University of Lisbon, Portugal.
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36
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Ma D, Tang G, Tian H, Zou G. Enantioselective syntheses of α-substituted glutamic acids and α,γ-disubstituted glutamic acids by an asymmetric Strecker reaction. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01121-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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37
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Dauban P, de Saint-Fuscien C, Dodd RH. Application of 2,3-aziridino-γ-lactone methodology toward the enantiospecific synthesis of the (3S,4S)-isomer of dihydroxy-L-glutamic acid. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00405-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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38
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Sutton JL, Maccecchini ML, Kajander KC. The kainate receptor antagonist 2S,4R-4-methylglutamate attenuates mechanical allodynia and thermal hyperalgesia in a rat model of nerve injury. Neuroscience 1999; 91:283-92. [PMID: 10336078 DOI: 10.1016/s0306-4522(98)00621-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Opioids and receptor antagonists of excitatory amino acids attenuate mechanical allodynia and thermal hyperalgesia in animal models of neuropathic pain. Recently, a kainate receptor antagonist, 2S,4R-4-methylglutamate, has been developed but has not been tested for antinociceptive effects in animal models of neuropathic pain. We evaluated whether 2S,4R-4-methylglutamate attenuated responses to mechanical and thermal stimuli in uninjured (control) rats and increased responsiveness in rats with chronic constriction injury. Rats were tested for a number of withdrawal responses using a calibrated von Frey filament (mechanical stimulus) and withdrawal latencies from a radiant heat source (thermal stimulus). In control rats, 2S,4R-4-methylglutamate produced a small but significant decrease in responses from the mechanical stimulus (25 mg/kg) and significantly increased withdrawal latencies from the thermal stimulus at the highest dose administered (100 mg/kg). In addition, 2S,4R-4-methylglutamate greatly attenuated increased responsiveness in rats with chronic constriction injury. At four to eight days following chronic constriction injury, animals that displayed increased responsiveness to mechanical and thermal stimuli were injected intraperitoneally with either dizocilpine maleate (0.1 mg/kg), morphine (4 mg/kg), vehicle as controls, or 2S,4R-4-methylglutamate (25, 50, 75 or 100 mg/kg). 2S,4R-4-Methylglutamate (25, 50, 75 and 100 mg/kg) significantly attenuated the frequency of responses to mechanical stimuli (Wilcoxon, P < 0.05) and the latency of responses to thermal stimuli (analysis of variance and Duncan's, P < 0.05). Dizocilpine maleate and morphine, as expected, also reduced these responses. These results suggest that, in addition to opioid and N-methyl-D-aspartate receptors, kainate receptors may play a role in the maintenance of mechanical allodynia and thermal hyperalgesia associated with peripheral nerve injury.
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Affiliation(s)
- J L Sutton
- Department of Oral Science, University of Minnesota, Minneapolis 55455, USA
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39
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Chittajallu R, Braithwaite SP, Clarke VR, Henley JM. Kainate receptors: subunits, synaptic localization and function. Trends Pharmacol Sci 1999; 20:26-35. [PMID: 10101959 DOI: 10.1016/s0165-6147(98)01286-3] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although it is well established that kainate receptors constitute an entirely separate group of proteins from AMPA receptors, their physiological functions remain unclear. The molecular cloning of subunits that form kainate receptors and the ability to study recombinant receptors is leading to an increased understanding of their functional properties. Furthermore, the development of kainate receptor-selective agonists and antagonists over the past few years is now allowing the physiological roles of these receptors and, in some cases, specific subunits to be investigated. As a consequence, the synaptic activation of postsynaptic kainate receptors and the presence of presynaptic kainate receptors that serve to regulate excitatory and inhibitory synaptic transmission have been described, and will be discussed in this article by Ramesh Chittajallu, Steven Braithwaite, Vernon Clarke and Jeremy Henley.
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Affiliation(s)
- R Chittajallu
- Department of Anatomy, Medical School, University of Bristol, UK
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40
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Dai WM, Ebert B, Madsen U, Lambert JD. Studies of the antagonist actions of (RS)-2-amino-3-[5-tert-butyl-3-(phosphonomethoxy)-4-isoxazolyl] propionic acid (ATPO) on non-NMDA receptors in cultured rat neurones. Br J Pharmacol 1998; 125:1517-28. [PMID: 9884081 PMCID: PMC1565742 DOI: 10.1038/sj.bjp.0702236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Whole-cell patch-clamp recordings from single cultured cortical neurones have been used to study the action of (RS)-2-amino-3-[5-tert-butyl-3-(phosphonomethoxy)-4-isoxazolyl+ ++]propionic acid (ATPO), which has previously been proposed to be a potent selective antagonist of 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptors. ATPO competitively reduced peak responses evoked by semi-rapid applications of AMPA (Ki = 16 microM) but had variable effects on plateau responses, which were on average unchanged. Following blockade of AMPA receptor desensitization by cyclothiazide (CTZ, 100 microM), the plateau responses were reduced by ATPO to a similar extent as the peak responses, indicating that ATPO reduces desensitization of AMPA receptors. Semi-rapid application of kainic acid (KA) and the KA receptor-selective agonist, (2S,4R)-4-methylglutamic acid (MeGlu) evoked non-desensitizing responses which were competitively antagonized by ATPO (Ki values: 27 and 23 microM, respectively). Responses to MeGlu were unaffected by CTZ (100 microM), but potentiated 3 fold following blockade of KA receptor desensitization by concanavalin A (Con A, 300 microg ml(-1)). Responses of spinal cord neurones to MeGlu were blocked by ATPO to a similar extent before and after blockade of KA receptor desensitization by Con A. Although selectively potentiated by Con A, plateau responses to MeGlu were reduced by 69.6% by the AMPA selective antagonist, GYKI 53655 (10 microM). The remaining component was further reduced by ATPO with a Ki of 36 microM, which was not significantly different from that in the absence of GYKI 53655, but was greater than that on responses to AMPA. It is concluded that ATPO is a moderate-potency competitive inhibitor of naturally expressed non-NMDA receptors.
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Affiliation(s)
- W M Dai
- Department of Physiology, University of Aarhus, Denmark
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41
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Helaine V, Bolte J. Chemo-enzymatic synthesis of the four stereoisomers of 4-hydroxy-4-methylglutamic acid. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0957-4166(98)00372-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Carroll FY, Finkelstein DI, Horne MK, Lawrence AJ, Crawford D, Paxinos G, Beart PM. Regional distribution of low affinity kainate receptors in brain of Macaca fascicularis determined by autoradiography using [3H](2S,4R)-4-methylglutamate. Neurosci Lett 1998; 255:71-4. [PMID: 9835217 DOI: 10.1016/s0304-3940(98)00720-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Binding of [3H](2S,4R)-4-methylglutamate, a novel low affinity kainate receptor agonist, was studied in brain sections of a Macaca fascicularis monkey. In cerebellar sections, [3H](2S,4R)-4-methylglutamate bound to a single population of sites (KD = 20 nM) and was inhibited by various glutamate receptor ligands: kainate > 6-cyano-7-nitroquinoxaline-2,3-dione > L-glutamate >> AMPA. (S)-5-lodowillardiine and (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid (ATPA), drugs selective for the GluR5 subunit, displaced 50% and 40% of binding, respectively. Autoradiography revealed topographic binding of [3H](2S,4R)-4-methylglutamate. Binding in cortex was highest in layer 5 and restricted to CA2/3 in hippocampus. Levels of binding were high in septum and hypothalamus. Moderate densities of binding were found in caudate-putamen, cerebellar granular layer, nucleus tractus solitarius, cuneate nucleus and area postrema. Binding in spinal cord was concentrated in dorsal horn. [3H](2S,4R)-4-Methylglutamate shows differential binding throughout primate brain and is a valuable new ligand for low affinity kainate receptors.
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Affiliation(s)
- F Y Carroll
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
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43
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Small B, Thomas J, Kemp M, Hoo K, Ballyk B, Deverill M, Ogden AM, Rubio A, Pedregal C, Bleakman D. LY339434, a GluR5 kainate receptor agonist. Neuropharmacology 1998; 37:1261-7. [PMID: 9849663 DOI: 10.1016/s0028-3908(98)00122-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The activity of a gamma-substituted glutamate analogue, (2S, 4R, 6E)-2-amino-4-carboxy-7-(2-naphthyl)hept-6-enoic acid (LY339434) and (2S,4R)-4-methylglutamic acid at ionotropic glutamate receptors has been examined. Ligand binding studies were performed using [3H] AMPA binding to membranes expressing either homomeric recombinant GluR1, GluR2, GluR4 receptors, and [3H] kainate binding to GluR5 and GluR6 kainate receptors. LY339434 and (2S,4R)-4-methylglutamic acid showed selectivity in ligand binding studies for kainate receptors over AMPA receptors. Within the kainate class of glutamate receptors, LY339434 showed selectivity for GluR5 over GluR6 whereas (2S,4R)-4-methylglutamic acid showed high affinity for both GluR5 and GluR6 kainate receptors. Examination of the functional activity of LY339434 and (2S,4R)-4-methylglutamic acid showed that both compounds evoked inward currents in dorsal root ganglion neurons (DRG) with estimated EC50 values of 0.8 +/- 0.2 microM and 0.17 +/- 0.04 microM, respectively. In GluR5 expressing HEK 293 cells, LY339434 evoked inward currents with an estimated EC50 value of 2.5 +/- 0.9 microM but had little effect on GluR6 expressing cells at concentrations less than 100 microM. LY339434 was a weak AMPA receptor agonist (EC50 values > 300 microM) as determined by activity in acutely isolated cerebellar Purkinje neurons. LY339434 and (2S,4R)-4-methylglutamic acid had agonist activity at NMDA receptors studied in cultured hippocampal neurons with EC50s of 2.5 microM and 11.7 microM, respectively. These results indicate that both LY339434 and (2S,4R)-4-methyl glutamic acid may be useful pharmacological tools for the examination of kainate receptors.
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Affiliation(s)
- B Small
- Lilly Research Centre, Windlesham, Surrey, UK
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44
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Affiliation(s)
- D Bleakman
- Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285, USA.
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45
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Guillena G, Mancheño B, Nájera C, Ezquerra J, Pedregal C. Stereoselective synthesis of 2,3-disubstituted glutamic acid derivatives by conjugate addition to 3,4-didehydropyroglutamates. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00573-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Hanessian S, Margarita R. 1,3-Asymmetric induction in dianionic allylation reactions of amino acid derivatives-synthesis of functionally useful enantiopure glutamates, pipecolates and pyroglutamates. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)00900-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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47
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Yamamoto C, Sawada S, Ohno-Shosaku T. Distribution and properties of kainate receptors distinct in the CA3 region of the hippocampus of the guinea pig. Brain Res 1998; 783:227-35. [PMID: 9507146 DOI: 10.1016/s0006-8993(97)01350-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To characterize the nature of kainate (KA) receptors distinct in the CA3 region of the hippocampus, properties of depolarizations induced by pulses of KA or AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate) applied to dendrites of CA3 neurons with micropipettes were studied in thin transverse slices of the guinea pig hippocampus. KA induced depolarizations at negligible latencies only when administered to the most proximal dendritic areas. The depolarization was unaffected by tetrodotoxin or by a decrease in Ca2+ and an increase in Mg2+ concentrations. The declining slope of the KA-induced depolarization was significantly slower than that of the AMPA-induced depolarization. In comparison with the AMPA-induced depolarization, the KA-induced depolarization was much less susceptible to antagonists such as 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) and 1-(4-aminophenyl)-4-methyl-7, 8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI52466). 6, 7,8,9-Tetrahydro-5-nitro-1H-benz[g]indole-2,3-dione-3-oxime (NS-102) and (2S,4R)-4-methylglutamate (SYM 2081) were without effects. The threshold concentration of pressure-ejected KA to induce depolarizations was about 200 nM. Excitatory postsynaptic potentials elicited by mossy fiber stimulation were more potently suppressed by CNQX than by GYKI52466. These results indicate that receptors responsible for the slow KA depolarization in the CA3 region of the hippocampus are not AMPA receptors but KA receptors. They are localized in the most proximal part of the apical dendrite and distinct from those observed in primary cultures of hippocampal neurons.
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Affiliation(s)
- C Yamamoto
- Department of Physiology, Faculty of Medicine, Kanazawa University, Kanazawa 920, Japan
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Shimamoto K, Lebrun B, Yasuda-Kamatani Y, Sakaitani M, Shigeri Y, Yumoto N, Nakajima T. DL-threo-beta-benzyloxyaspartate, a potent blocker of excitatory amino acid transporters. Mol Pharmacol 1998; 53:195-201. [PMID: 9463476 DOI: 10.1124/mol.53.2.195] [Citation(s) in RCA: 471] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DL-threo-beta-Benzyloxyaspartate (DL-TBOA), a novel derivative of DL-threo-beta-hydroxyaspartate, was synthesized and examined as an inhibitor of sodium-dependent glutamate/aspartate (excitatory amino acid) transporters. DL-TBOA inhibited the uptake of [14C]glutamate in COS-1 cells expressing the human excitatory amino acid transporter-1 (EAAT1) (Ki = 42 microM) with almost the same potency as DL-threo-beta-hydroxyaspartate (Ki = 58 microM). With regard to the human excitatory amino acid transporter-2 (EAAT2), the inhibitory effect of DL-TBOA (Ki = 5.7 microM) was much more potent than that of dihydrokainate (Ki = 79 microM), which is well known as a selective blocker of this subtype. Electrophysiologically, DL-TBOA induced no detectable inward currents in Xenopus laevis oocytes expressing human EAAT1 or EAAT2. However, it significantly reduced the glutamate-induced currents, indicating the prevention of transport. The dose-response curve of glutamate was shifted by adding DL-TBOA without a significant change in the maximum current. The Kb values for human EAAT1 and EAAT2 expressed in X. laevis oocytes were 9.0 microM and 116 nM, respectively. These results demonstrated that DL-TBOA is, so far, the most potent competitive blocker of glutamate transporters. DL-TBOA did not show any significant effects on either the ionotropic or metabotropic glutamate receptors. Moreover, DL-TBOA is chemically much more stable than its benzoyl analog, a previously reported blocker of excitatory amino acid transporters; therefore, DL-TBOA should be a useful tool for investigating the physiological roles of transporters.
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Affiliation(s)
- K Shimamoto
- Suntory Institute for Bioorganic Research, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618, Japan.
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49
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New amino acids derived from L-pyroglutamic acid: Synthesis of Trans-4-benzyl-cis-5-phenyl-L-proline, L-α-(2-benzyl-3-phenylpropyl)-glycine and L-α-(3-phenylpropyl)-glycine. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(97)10399-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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The first example of asymmetric Michael reaction catalyzed by chiral alkali metal alkoxides. Russ Chem Bull 1998. [DOI: 10.1007/bf02495512] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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