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Brioude F, Kalish JM, Mussa A, Foster AC, Bliek J, Ferrero GB, Boonen SE, Cole T, Baker R, Bertoletti M, Cocchi G, Coze C, De Pellegrin M, Hussain K, Ibrahim A, Kilby MD, Krajewska-Walasek M, Kratz CP, Ladusans EJ, Lapunzina P, Le Bouc Y, Maas SM, Macdonald F, Õunap K, Peruzzi L, Rossignol S, Russo S, Shipster C, Skórka A, Tatton-Brown K, Tenorio J, Tortora C, Grønskov K, Netchine I, Hennekam RC, Prawitt D, Tümer Z, Eggermann T, Mackay DJG, Riccio A, Maher ER. Expert consensus document: Clinical and molecular diagnosis, screening and management of Beckwith-Wiedemann syndrome: an international consensus statement. Nat Rev Endocrinol 2018; 14:229-249. [PMID: 29377879 PMCID: PMC6022848 DOI: 10.1038/nrendo.2017.166] [Citation(s) in RCA: 308] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Beckwith-Wiedemann syndrome (BWS), a human genomic imprinting disorder, is characterized by phenotypic variability that might include overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycaemia, lateralized overgrowth and predisposition to embryonal tumours. Delineation of the molecular defects within the imprinted 11p15.5 region can predict familial recurrence risks and the risk (and type) of embryonal tumour. Despite recent advances in knowledge, there is marked heterogeneity in clinical diagnostic criteria and care. As detailed in this Consensus Statement, an international consensus group agreed upon 72 recommendations for the clinical and molecular diagnosis and management of BWS, including comprehensive protocols for the molecular investigation, care and treatment of patients from the prenatal period to adulthood. The consensus recommendations apply to patients with Beckwith-Wiedemann spectrum (BWSp), covering classical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly. Although the consensus group recommends a tumour surveillance programme targeted by molecular subgroups, surveillance might differ according to the local health-care system (for example, in the United States), and the results of targeted and universal surveillance should be evaluated prospectively. International collaboration, including a prospective audit of the results of implementing these consensus recommendations, is required to expand the evidence base for the design of optimum care pathways.
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Affiliation(s)
- Frédéric Brioude
- Sorbonne Université, Pierre and Marie Curie-Paris VI University (UPMC) Université Paris 06, INSERM UMR_S938 Centre de Recherche Saint-Antoine (CRSA), APHP Hôpital Trousseau, Explorations Fonctionnelles Endocriniennes, 26 Avenue du Docteur Arnold Netter, F-75012 Paris, France
| | - Jennifer M Kalish
- Division of Human Genetics, Children's Hospital of Philadelphia and the Department of Pediatrics at the Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alessandro Mussa
- Department of Public Health and Pediatric Sciences, University of Torino, Piazza Polonia 94, 10126 Torino, Italy
- Neonatal Intensive Care Unit, Department of Gynaecology and Obstetrics, Sant'Anna Hospital, Città della Salute e della Scienza di Torino, Corso Spezia 60, 10126 Torino, Italy
| | - Alison C Foster
- Birmingham Health Partners, West Midlands Regional Genetics Service, Birmingham Women's and Children's National Health Service (NHS) Foundation Trust, Birmingham B15 2TG, UK
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Jet Bliek
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, PO Box 7057 1007 MB Amsterdam, The Netherlands
| | - Giovanni Battista Ferrero
- Department of Public Health and Pediatric Sciences, University of Torino, Piazza Polonia 94, 10126 Torino, Italy
| | - Susanne E Boonen
- Clinical Genetic Unit, Department of Pediatrics, Zealand University Hospital, Sygehusvej 10 4000 Roskilde, Denmark
| | - Trevor Cole
- Birmingham Health Partners, West Midlands Regional Genetics Service, Birmingham Women's and Children's National Health Service (NHS) Foundation Trust, Birmingham B15 2TG, UK
| | - Robert Baker
- Beckwith-Wiedemann Support Group UK, The Drum and Monkey, Wonston, Hazelbury Bryan, Sturminster Newton, Dorset DT10 2EE, UK
| | - Monica Bertoletti
- Italian Association of Beckwith-Wiedemann syndrome (AIBWS) Piazza Turati, 3, 21029, Vergiate (VA), Italy
| | - Guido Cocchi
- Alma Mater Studiorum, Bologna University, Paediatric Department, Neonatology Unit, Via Massarenti 11, 40138 Bologna BO, Italy
| | - Carole Coze
- Aix-Marseille Univ et Assistance Publique Hôpitaux de Marseille (APHM), Hôpital d'Enfants de La Timone, Service d'Hématologie-Oncologie Pédiatrique, 264 Rue Saint Pierre, 13385 Marseille, France
| | - Maurizio De Pellegrin
- Pediatric Orthopaedic Unit IRCCS Ospedale San Raffaele, Milan, Via Olgettina Milano, 60, 20132 Milano MI, Italy
| | - Khalid Hussain
- Department of Paediatric Medicine, Division of Endocrinology, Sidra Medical and Research Center, Al Gharrafa Street, Ar-Rayyan, Doha, Qatar
| | - Abdulla Ibrahim
- Department of Plastic and Reconstructive Surgery, North Bristol National Health Service (NHS) Trust, Southmead Hospital, Bristol BS10 5NB, UK
| | - Mark D Kilby
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Fetal Medicine Centre, Birmingham Women's and Children's National Health Service (NHS) Foundation Trust, Edgbaston, Birmingham, B15 2TG, UK
| | | | - Christian P Kratz
- Pediatric Hematology and Oncology, Hannover Medical School, Carl-Neuberg-Strasse 1 30625, Hannover, Germany
| | - Edmund J Ladusans
- Department of Paediatric Cardiology, Royal Manchester Children's Hospital, Manchester, M13 8WL UK
| | - Pablo Lapunzina
- Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM Paseo de La Castellana, 261, 28046, Madrid, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Calle de Melchor Fernández Almagro, 3, 28029, Madrid, Spain
| | - Yves Le Bouc
- Sorbonne Université, Pierre and Marie Curie-Paris VI University (UPMC) Université Paris 06, INSERM UMR_S938 Centre de Recherche Saint-Antoine (CRSA), APHP Hôpital Trousseau, Explorations Fonctionnelles Endocriniennes, 26 Avenue du Docteur Arnold Netter, F-75012 Paris, France
| | - Saskia M Maas
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, PO Box 7057 1007 MB Amsterdam, The Netherlands
| | - Fiona Macdonald
- West Midlands Regional Genetics Laboratory, Birmingham Women's and Children's National Health Service (NHS) Foundation Trust, Birmingham, B15 2TG UK
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital and Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, L. Puusepa 2, 51014, Tartu, Estonia
| | - Licia Peruzzi
- European Society for Paediatric Nephrology (ESPN), Inherited Kidney Disorders Working Group
- AOU Città della Salute e della Scienza di Torino, Regina Margherita Children's Hospital, Turin, Italy
| | - Sylvie Rossignol
- Service de Pédiatrie, Hôpitaux Universitaires de Strasbourg, Laboratoire de Génétique Médicale, INSERM U1112 Avenue Molière 67098 STRASBOURG Cedex, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, 4 Rue Kirschleger, 67000 Strasbourg, France
| | - Silvia Russo
- Medical Cytogenetics and Molecular Genetics Laboratory, Centro di Ricerche e Tecnologie Biomediche IRCCS, Istituto Auxologico Italiano, Via Zucchi 18, 20095 Cusano, Milan, Italy
| | - Caroleen Shipster
- Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, WC1N 3JH, UK
| | - Agata Skórka
- Department of Medical Genetics, The Children's Memorial Health Institute, 20, 04-730, Warsaw, Poland
- Department of Pediatrics, The Medical University of Warsaw, Zwirki i Wigury 63a, 02-091 Warszawa, Poland
| | - Katrina Tatton-Brown
- South West Thames Regional Genetics Service and St George's University of London and Institute of Cancer Research, London, SW17 0RE, UK
| | - Jair Tenorio
- Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM Paseo de La Castellana, 261, 28046, Madrid, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Calle de Melchor Fernández Almagro, 3, 28029, Madrid, Spain
| | - Chiara Tortora
- Regional Center for CLP, Smile House, San Paolo University Hospital, Via Antonio di Rudinì, 8, 20142, Milan, Italy
| | - Karen Grønskov
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Irène Netchine
- Sorbonne Université, Pierre and Marie Curie-Paris VI University (UPMC) Université Paris 06, INSERM UMR_S938 Centre de Recherche Saint-Antoine (CRSA), APHP Hôpital Trousseau, Explorations Fonctionnelles Endocriniennes, 26 Avenue du Docteur Arnold Netter, F-75012 Paris, France
| | - Raoul C Hennekam
- Department of Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam-Zuidoost, Amsterdam, The Netherlands
| | - Dirk Prawitt
- Center for Pediatrics and Adolescent Medicine, Johannes Gutenberg University Medical Center, Langenbeckstr. 1, D-55101, Mainz, Germany
| | - Zeynep Tümer
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Thomas Eggermann
- Institute of Human Genetics, University Hospital, Technical University of Aachen, Templergraben 55, 52062, Aachen, Germany
| | - Deborah J G Mackay
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK
| | - Andrea Riccio
- Department of Environmental, Biological, and Pharmaceutical Sciences and Technologies (DiSTABiF), University of Campania Luigi Vanvitelli, Caserta and Institute of Genetics and Biophysics "A. Buzzati-Traverso" - CNR, Via Pietro Castellino, 111,80131, Naples, Italy
| | - Eamonn R Maher
- Department of Medical Genetics, University of Cambridge and National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre and Cancer Research UK Cambridge Centre, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK
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Colbon PJJ, Foster AC, Giles ME, Patel Z, Singleton JT. A general and efficient route to 6-methyl-pyrazin-2-yl-amines: Alkylation of 2,6-dichloropyrazineviamalonate derivatives. J Heterocycl Chem 2008. [DOI: 10.1002/jhet.5570450531] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Joppa MA, Gogas KR, Foster AC, Markison S. Central infusion of the melanocortin receptor antagonist agouti-related peptide (AgRP(83-132)) prevents cachexia-related symptoms induced by radiation and colon-26 tumors in mice. Peptides 2007; 28:636-42. [PMID: 17204351 DOI: 10.1016/j.peptides.2006.11.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Revised: 11/28/2006] [Accepted: 11/29/2006] [Indexed: 01/08/2023]
Abstract
Cachexia is a clinical wasting syndrome that occurs in multiple disease states, and is associated with anorexia and a progressive loss of body fat and lean mass. The development of new therapeutics for this disorder is needed due to poor efficacy and multiple side effects of current therapies. The pivotal role played by the central melanocortin system in regulating body weight has made this an attractive target for novel cachexia therapies. The mixed melanocortin receptor antagonist AgRP is an endogenous peptide that induces hyperphagia. Here, we used AgRP(83-132) to investigate the ability of melanocortin antagonism to protect against clinical features of cachexia in two distinct animal models. In an acute model, food intake and body weight gain were reduced in mice exposed to radiation (300 RAD), and delivery of AgRP(83-132) into the lateral cerebral ventricle prevented these effects. In a chronic tumor cachexia model, adult mice were injected subcutaneously with a cell line derived from murine colon-26 adenocarcinoma. Typical of cachexia, tumor-bearing mice progressively reduced body weight and food intake, and gained significantly less muscle mass than controls. Administration of AgRP(83-132) into the lateral ventricles significantly increased body weight and food intake, and changes in muscle mass were similar to the tumor-free control mice. These findings support the idea that antagonism of the central melanocortin system can reduce the negative impact of cachexia and radiation therapy.
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Affiliation(s)
- M A Joppa
- Neurocrine Biosciences, Inc., 12790 El Camino Real, San Diego, CA 92130, USA
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4
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Selkirk JV, Nottebaum LM, Lee J, Yang W, Foster AC, Lechner SM. Identification of differential melanocortin 4 receptor agonist profiles at natively expressed receptors in rat cortical astrocytes and recombinantly expressed receptors in human embryonic kidney cells. Neuropharmacology 2006; 52:459-66. [PMID: 17095023 DOI: 10.1016/j.neuropharm.2006.08.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/01/2006] [Accepted: 08/02/2006] [Indexed: 11/25/2022]
Abstract
Using cAMP accumulation as a functional readout, we pharmacologically characterized the response of native melanocortin receptors in cultured rat astrocytes, and found this response to be mediated by the melanocortin 4 receptor (MC4R). Melancortin agonists stimulate cAMP in a concentration-dependent manner in both astrocytes and human embryonic kidney cells recombinantly expressing rat MC4R (HEK-rMC4R), however, the relative potency and intrinsic activity of both small molecule and peptide agonists are reduced in the native system. As such, the small molecules THIQ, NBI-702 and MB243 display 43, 30 and 18% of the maximal response elicited by alpha-MSH in astrocytes. Likewise, the peptides MTII and ACTH display 55 and 72% of the maximal response elicited by alpha-MSH in these cells. In contrast, all of these compounds elicit full agonist responses with similar intrinsic activity to alpha-MSH in HEK-rMC4R cells. MC4R mRNA was detected in astrocytes, however radioligand binding experiments failed to detect measurable MC4R in astrocyte membranes, in contrast to membranes from HEK-rMC4R cells that display a binding site density of 18.1+/-1.5 fmol/mg. We propose that the divergent observations in functional activity between the cell types reflect differences in receptor expression and that caution should be exercised when interpreting agonist activity in over-expression systems for the purposes of drug discovery.
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MESH Headings
- Animals
- Animals, Newborn
- Astrocytes
- Binding Sites/drug effects
- Cells, Cultured
- Cerebral Cortex/cytology
- Cyclic AMP/metabolism
- Cyclic AMP Response Element-Binding Protein/metabolism
- Dose-Response Relationship, Drug
- Embryo, Mammalian
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Hormones/pharmacology
- Humans
- Inhibitory Concentration 50
- Kidney
- Protein Binding/drug effects
- Rats
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Time Factors
- alpha-MSH/pharmacology
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Affiliation(s)
- J V Selkirk
- Department of Neuroscience, Neurocrine Biosciences Inc., 12790 El Camino Real, San Diego, CA 92130, USA.
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5
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Haislip JB, Nysewander MC, Reichart DE, Levan A, Tanvir N, Cenko SB, Fox DB, Price PA, Castro-Tirado AJ, Gorosabel J, Evans CR, Figueredo E, MacLeod CL, Kirschbrown JR, Jelinek M, Guziy S, de Ugarte Postigo A, Cypriano ES, LaCluyze A, Graham J, Priddey R, Chapman R, Rhoads J, Fruchter AS, Lamb DQ, Kouveliotou C, Wijers RAMJ, Bayliss MB, Schmidt BP, Soderberg AM, Kulkarni SR, Harrison FA, Moon DS, Gal-Yam A, Kasliwal MM, Hudec R, Vitek S, Kubanek P, Crain JA, Foster AC, Clemens JC, Bartelme JW, Canterna R, Hartmann DH, Henden AA, Klose S, Park HS, Williams GG, Rol E, O'Brien P, Bersier D, Prada F, Pizarro S, Maturana D, Ugarte P, Alvarez A, Fernandez AJM, Jarvis MJ, Moles M, Alfaro E, Ivarsen KM, Kumar ND, Mack CE, Zdarowicz CM, Gehrels N, Barthelmy S, Burrows DN. A photometric redshift of z = 6.39 ± 0.12 for GRB 050904. Nature 2006; 440:181-3. [PMID: 16525465 DOI: 10.1038/nature04552] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Accepted: 12/12/2005] [Indexed: 11/09/2022]
Abstract
Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z approximately 20, and therefore to be powerful probes of the early Universe. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be z = 6.39 - 0.12 + 0.11 (refs 5-7). Subsequently, it was measured spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe.
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Affiliation(s)
- J B Haislip
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Campus Box 3255, Chapel Hill, North Carolina 27599, USA
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6
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Joppa MA, Ling N, Chen C, Gogas KR, Foster AC, Markison S. Central administration of peptide and small molecule MC4 receptor antagonists induce hyperphagia in mice and attenuate cytokine-induced anorexia. Peptides 2005; 26:2294-301. [PMID: 16269355 DOI: 10.1016/j.peptides.2005.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 03/02/2005] [Accepted: 03/03/2005] [Indexed: 11/20/2022]
Abstract
We investigated the effect of melanocortin 4 receptor (MC4) antagonists on food intake in mice. Food intake during the light phase was significantly increased by ICV administration of mixed MC3/MC4 antagonists (AgRP and SHU9119) or MC4 selective antagonist peptide [(Cyclo (1-5)[Suc-D-Nal-Arg-Trp-Lys]NH2] (MBP10) and the small molecule antagonists THP and NBI-30. Both mixed and selective antagonists significantly reversed anorexia induced by ICV administration of the MC4 agonist (c (1-6) HfRWK-NH2) and the cytokine IL-1beta. These findings provide pharmacological evidence that the MC4 receptor mediates the effects of melanocortin agonists and antagonists on food intake in mice, and support the idea that selective small molecule MC4 antagonists may be useful as therapeutics for cachexia.
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Affiliation(s)
- M A Joppa
- Neurocrine Biosciences Inc., San Diego, CA 92130, USA
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7
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Alcaraz ML, Atkinson S, Cornwall P, Foster AC, Gill DM, Humphries LA, Keegan PS, Kemp R, Merifield E, Nixon RA, Noble AJ, O'Beirne D, Patel ZM, Perkins J, Rowan P, Sadler P, Singleton JT, Tornos J, Watts AJ, Woodland IA. Efficient Syntheses of AZD4407 via Thioether Formation by Nucleophilic Attack of Organometallic Species on Sulphur. Org Process Res Dev 2005. [DOI: 10.1021/op0500483] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marie-Lyne Alcaraz
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Stéphanie Atkinson
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Philip Cornwall
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Alison C. Foster
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Duncan M. Gill
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Lesley A. Humphries
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Philip S. Keegan
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Richard Kemp
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Eric Merifield
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Robert A. Nixon
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Allison J. Noble
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Darren O'Beirne
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Zakariya M. Patel
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Jacob Perkins
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Paul Rowan
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Paul Sadler
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - John T. Singleton
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - James Tornos
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Andrew J. Watts
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
| | - Ian A. Woodland
- AstraZeneca R&D Charnwood, Process R&D, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, United Kingdom
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Amat J, Tamblyn JP, Paul ED, Bland ST, Amat P, Foster AC, Watkins LR, Maier SF. Microinjection of urocortin 2 into the dorsal raphe nucleus activates serotonergic neurons and increases extracellular serotonin in the basolateral amygdala. Neuroscience 2005; 129:509-19. [PMID: 15541873 DOI: 10.1016/j.neuroscience.2004.07.052] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2004] [Indexed: 10/26/2022]
Abstract
The intra dorsal raphe nucleus (DRN) administration of corticotropin releasing hormone (CRF) inhibits serotonergic (5-HT) activity in this structure, an effect blocked by antagonists selective for the type 1 CRF receptor (CRF1). The DRN has a high density of the type 2 receptor (CRF2), and so the present experiments explored the impact of CRF2 activation within the DRN on 5-HT function. The intra-DRN administration of the selective CRF2 agonist urocortin 2 (Ucn 2) dose dependently increased 5-HT efflux in the basolateral amygdala, a projection region of the DRN. Intra-DRN Ucn 2 also increased c-fos expression in labeled 5-HT neurons. Both of these effects of Ucn 2 were completely blocked by intra-DRN antisauvagine-30 (ASV-30), a relatively selective CRF2 antagonist. These data suggest that CRF1 and CRF2 activation within the DRN affect 5-HT neurons in opponent fashion. Implications of these results for understanding the behavioral effects of CRF and other CRF-like ligands are discussed.
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Affiliation(s)
- J Amat
- Department of Psychology and Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309-0345, USA.
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9
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Milligan ED, Zapata V, Chacur M, Schoeniger D, Biedenkapp J, O'Connor KA, Verge GM, Chapman G, Green P, Foster AC, Naeve GS, Maier SF, Watkins LR. Evidence that exogenous and endogenous fractalkine can induce spinal nociceptive facilitation in rats. Eur J Neurosci 2004; 20:2294-302. [PMID: 15525271 DOI: 10.1111/j.1460-9568.2004.03709.x] [Citation(s) in RCA: 222] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent evidence suggests that spinal cord glia can contribute to enhanced nociceptive responses. However, the signals that cause glial activation are unknown. Fractalkine (CX3C ligand-1; CX3CL1) is a unique chemokine expressed on the extracellular surface of spinal neurons and spinal sensory afferents. In the dorsal spinal cord, fractalkine receptors are primarily expressed by microglia. As fractalkine can be released from neurons upon strong activation, it has previously been suggested to be a neuron-to-glial signal that induces glial activation. The present series of experiments provide an initial investigation of the spinal pain modulatory effects of fractalkine. Intrathecal fractalkine produced dose-dependent mechanical allodynia and thermal hyperalgesia. In addition, a single injection of fractalkine receptor antagonist (neutralizing antibody against rat CX3C receptor-1; CX3CR1) delayed the development of mechanical allodynia and/or thermal hyperalgesia in two neuropathic pain models: chronic constriction injury (CCI) and sciatic inflammatory neuropathy. Intriguingly, anti-CX3CR1 reduced nociceptive responses when administered 5-7 days after CCI, suggesting that prolonged release of fractalkine may contribute to the maintenance of neuropathic pain. Taken together, these initial investigations of spinal fractalkine effects suggest that exogenous and endogenous fractalkine are involved in spinal sensitization, including that induced by peripheral neuropathy.
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MESH Headings
- Animals
- Antibodies/pharmacology
- CX3C Chemokine Receptor 1
- Cell Communication/drug effects
- Cell Communication/physiology
- Chemokine CX3CL1
- Chemokines, CX3C/administration & dosage
- Chemokines, CX3C/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Hyperalgesia/chemically induced
- Hyperalgesia/metabolism
- Hyperalgesia/physiopathology
- Injections, Spinal
- Ligation
- Male
- Membrane Proteins/administration & dosage
- Membrane Proteins/drug effects
- Membrane Proteins/metabolism
- Microglia/drug effects
- Microglia/metabolism
- Neuroglia/drug effects
- Neuroglia/metabolism
- Neurons/metabolism
- Nociceptors/drug effects
- Nociceptors/physiology
- Pain/chemically induced
- Pain/metabolism
- Pain/physiopathology
- Peripheral Nervous System Diseases/chemically induced
- Peripheral Nervous System Diseases/metabolism
- Peripheral Nervous System Diseases/physiopathology
- Rats
- Rats, Sprague-Dawley
- Receptors, Cytokine/antagonists & inhibitors
- Receptors, Cytokine/metabolism
- Receptors, HIV/antagonists & inhibitors
- Receptors, HIV/metabolism
- Sciatic Neuropathy/chemically induced
- Sciatic Neuropathy/metabolism
- Sciatic Neuropathy/physiopathology
- Spinal Cord/drug effects
- Spinal Cord/metabolism
- Spinal Cord/physiopathology
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Affiliation(s)
- E D Milligan
- Department of Psychology & the Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309-0345, USA
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10
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Selkirk JV, Naeve GS, Foster AC. Blockade of excitatory amino acid transporters in the rat hippocampus results in enhanced activation of group I and group III metabotropic glutamate receptors. Neuropharmacology 2003; 45:885-94. [PMID: 14573381 DOI: 10.1016/s0028-3908(03)00233-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The idea that excitatory amino acid transporters (EAATs) can control the activation of specific metabotropic glutamate receptors (mGluRs) was investigated in rat hippocampal slices. Using the accumulation of inositol phosphates as a measure of group I mGluR activity, we have shown that the broad spectrum, non-transportable EAAT blocker, TBOA, produces a significant shift to the left of agonist concentration-response curves. Moreover, this increase in potency did not occur if endogenous glutamate was enzymatically removed, suggesting a glutamate-dependent mechanism. This shift in potency was shown to be NMDA and group II mGlu receptor independent. Additionally, experiments with selective antagonists indicated that the group I receptor responsible for the stimulation of inositol phosphate production in this preparation is likely to be mGluR5. Inhibition of forskolin-stimulated cyclic AMP (cAMP) production was used as an index of group II/III mGluR activity. TBOA produced a rightward shift of the forskolin concentration-response curve. A group III, but not a group II, mGluR agonist also produced this effect, suggesting that the TBOA-mediated increase in glutamate activates a receptor, which appears to be a member of the group III mGluR subset. This was confirmed by the observation that an antagonist of group III mGluRs, prevented the TBOA-induced rightward shift in forskolin potency. These results provide evidence of a role for EAATs in the regulation of mGluR5 and group III mGluRs in the rat hippocampus, which may have therapeutic implications.
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Affiliation(s)
- J V Selkirk
- Neurocrine Biosciences, 10555 Science Center Drive, San Diego, CA 92121, USA.
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11
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Dixon DJ, Foster AC, Ley SV. The total synthesis of (+)-aspicilin using 2,3-butane diacetal protected butane tetrols via a chiral memory protocol. CAN J CHEM 2001. [DOI: 10.1139/v01-144] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The total syntheses of the polyhydroxylated macrolactone (+)-aspicilin and a diastereoisomer have been achieved via a concise route, starting from the spatially desymmetrized (R',R',R,S)-2,3-butanediacetal-protected butane tetrol 13. The key steps include a regioselective silyl protection of 13 and a stereoselective Lewis acid mediated addition of allyltributylstannane to the equatorially disposed aldehyde of 4. Macrocyclization is achieved using ring closing metathesis, after which selective hydrogenation and protecting group removal yields the natural product.Key words: aspicilin, butanediacetal, desymmetrization, macrolactone, metathesis.
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12
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Mackay KB, Bozigian H, Grigoriadis DE, Loddick SA, Verge G, Foster AC. Neuroprotective effects of the CRF1 antagonist R121920 after permanent focal ischemia in the rat. J Cereb Blood Flow Metab 2001; 21:1208-14. [PMID: 11598498 DOI: 10.1097/00004647-200110000-00009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The neuroprotective effects of a systemically active, highly selective, corticotropin-releasing factor-1 (CRF1) receptor antagonist, R121920 ((7-(dipropylamino)-2,5-dimethyl-3- [2-(dimethylamino)-5-pyridyl] pyrazolo [1,5-a] pyrimidine), was assessed in two rat models of permanent focal cerebral ischemia, where the middle cerebral artery (MCA) was occluded either through the subtemporal approach or using the intraluminal suture technique. R121920 rapidly crossed the blood-brain barrier after intravenous (IV) bolus administration (10 mg/kg), with peak brain concentrations at 5 minutes (2.26 +/- 0.40 microg/mL), which were approximately 2-fold greater than those in plasma (0.98 +/- 0.24 microg/mL). Treatment with R121920 (10 mg/kg IV followed by 5 mg/kg subcutaneously at hourly intervals for 4 hours) significantly (P < 0.001) reduced total (by 40%) and cortical (by 37%) infarct volume at 24 hours after subtemporal MCA occlusion (MCAO). In the intraluminal suture MCAO model, IV administration of R121920 (10 mg/kg) at the time of ischemia onset (and at multiple times thereafter) reduced both hemispheric infarct volume (by 34%, P < 0.001) and brain swelling (by 50%, P < 0.001) when assessed at 24 hours. In this model of focal ischemia, significant reduction (P < 0.05) in both outcome measures was obtained when R121920 administration was delayed up to 1 hour after MCAO. These results further define the antiischemic properties of selective CRF 1 antagonists in two experimental models of permanent focal cerebral ischemia.
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Affiliation(s)
- K B Mackay
- Neurocrine Biosciences Inc., San Diego, California 92121-1102, USA
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13
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Eliasof S, McIlvain HB, Petroski RE, Foster AC, Dunlop J. Pharmacological characterization of threo-3-methylglutamic acid with excitatory amino acid transporters in native and recombinant systems. J Neurochem 2001; 77:550-7. [PMID: 11299317 DOI: 10.1046/j.1471-4159.2001.00253.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The glutamate analog (+/-) threo-3-methylglutamate (T3MG) has recently been reported to inhibit the EAAT2 but not EAAT1 subtype of high-affinity, Na(+)-dependent excitatory amino acid transporter (EAAT). We have examined the effects of T3MG on glutamate-elicited currents mediated by EAATs 1-4 expressed in Xenopus oocytes and on the transport of radiolabeled substrate in mammalian cell lines expressing EAATs 1-3. T3MG was found to be an inhibitor of EAAT2 and EAAT4 but a weak inhibitor of EAAT1 and EAAT3. T3MG competitively inhibited uptake of D-[(3)H]-aspartate into both cortical and cerebellar synaptosomes with a similar potency, consistent with its inhibitory activity on the cloned EAAT2 and EAAT4 subtypes. In addition, T3MG produced substrate-like currents in oocytes expressing EAAT4 but not EAAT2. However, T3MG was unable to elicit heteroexchange of preloaded D-[(3)H]-aspartate in cerebellar synaptosomes, inconsistent with the behavior of a substrate inhibitor. Finally, T3MG acts as a poor ionotropic glutamate receptor agonist in cultured hippocampal neurons: concentrations greater than 100 microM T3MG were required to elicit significant NMDA receptor-mediated currents. Thus, T3MG represents a pharmacological tool for the study of not only the predominant EAAT2 subtype but also the EAAT4 subtype highly expressed in cerebellum.
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Affiliation(s)
- S Eliasof
- Neurocrine Biosciences Inc., San Diego, California, USA Wyeth Neuroscience, Wyeth-Ayerst Research, Princeton, New Jersey, USA
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14
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Abstract
Although there is considerable information regarding the role of brain CRF in energy balance, relatively little is known about the role of urocortin (UCN), which is an equally potent anorexic agent. Therefore, the effects of intracerebroventricular (icv) administration of UCN (0.01-1 nmol/day) on food intake and body weight were assessed over a period of 13 days and compared with data from CRF-infused counterparts. Although both peptides dose dependently reduced food intake and weight gain, the effects of CRF were much greater in magnitude than those of UCN, particularly on body weight. Pair-feeding studies suggested that, while the effects of CRF on body weight could not be completely explained by appetite suppression, the effects of UCN appeared to be due to its initial impact on food intake. CRF increased brown adipose fat pad and adrenal weights, whereas it reduced thymus and spleen weights. CRF also increased serum corticosterone, triglyceride, FFA, and cholesterol levels, whereas it reduced glucose. UCN did not produce any consistent changes in any of these indices of sympathetic nervous system activation. Concurrent administration of the CRF(2)-selective antagonist, antisauvagine-30 (ASV-30) (30 nmol/day) completely reversed or attenuated the effects of UCN and CRF (1 nmol/day) on food intake and body weight. ASV-30 did not significantly attenuate any of the above CRF-induced changes in tissue weights or serum chemistry. These data suggest that the central CRF(2) receptor may primarily mediate the anorexic, but not the metabolic effects of CRF.
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Affiliation(s)
- M J Cullen
- Department of Neuroscience, Neurocrine Biosciences, Inc., San Diego, California 92121, USA
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15
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Ley SV, Baeschlin DK, Dixon DJ, Foster AC, Ince SJ, Priepke HW, Reynolds DJ. 1,2-diacetals: a new opportunity for organic synthesis. Chem Rev 2001; 101:53-80. [PMID: 11712194 DOI: 10.1021/cr990101j] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S V Ley
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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16
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Pelleymounter MA, Joppa M, Carmouche M, Cullen MJ, Brown B, Murphy B, Grigoriadis DE, Ling N, Foster AC. Role of corticotropin-releasing factor (CRF) receptors in the anorexic syndrome induced by CRF. J Pharmacol Exp Ther 2000; 293:799-806. [PMID: 10869378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Genetic manipulations of corticotropin-releasing factor (CRF)(1) and CRF(2) receptors have resulted in data suggesting that the CRF(2) receptor could mediate the effects of CRF on appetite or satiety. We have attempted to obtain pharmacological evidence for this hypothesis by comparing the ability of a high-affinity peptide, mixed CRF antagonist [cyclo 30-33,f12,L18,21E30, A32,K33]sucker fish urotensin (12-41)NH(2) [cUTSN (12-41)] with a small-molecule CRF(1)-selective antagonist, NBI-27914, and a CRF(2)-selective peptide antagonist, antisauvagine-30, to attenuate the anorexic effects of CRF. We also monitored other behaviors that accompanied CRF-induced anorexia. CRF-induced anorexia was significantly correlated with a reduction in locomotor activity and an increase in freezing behavior and piloerection. cUTSN (12-41) and antisauvagine-30 significantly attenuated the effects of CRF (0.04 nmol) on food intake along with the behavioral syndrome that accompanied anorexia. In contrast, NBI-27914 did not attenuate either of the above-mentioned CRF-induced phenomena when given centrally at doses ranging from 0.13 to 10 nmol/2.5 microl or when given orally at 20 to 40 mg/kg. Although these data support the hypothesis that the CRF(2) receptor mediates the appetite suppression induced by CRF, they also suggest that the CRF(2) receptor could mediate the stress-like behaviors that accompany CRF-induced appetite suppression.
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Affiliation(s)
- M A Pelleymounter
- Department of Neuroscience, Pharmacology, and Peptide Chemistry, Neurocrine Biosciences, San Diego, CA 92121, USA.
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17
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Naeve GS, Vana AM, Eggold JR, Verge G, Ling N, Foster AC. Expression of rat insulin-like growth factor binding protein-6 in the brain, spinal cord, and sensory ganglia. Brain Res Mol Brain Res 2000; 75:185-97. [PMID: 10686339 DOI: 10.1016/s0169-328x(99)00262-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Insulin-like growth factors (IGFs) are important trophic factors during development as well as in the adult or damaged nervous system. Their trophic actions are modulated by interactions with six distinct IGF binding proteins. The mRNA expression profiles of binding proteins 2, 4 and 5 in the normal developing and adult CNS are well characterized and are shown to have distinctive, non-overlapping distributions. The IGF binding protein-6 (BP6) is also expressed in the CNS, however, details regarding its mRNA expression distribution in the developing and adult nervous system is limited. BP6 has the unique property of preferentially binding the IGF-II ligand. Coupled with the fact that this ligand is the most abundantly expressed IGF in the adult CNS, this suggests that the IGF-II/BP6 complex has a unique role in modulating IGF-II function in the adult brain. In this report the anatomical distribution of BP6 messenger RNA in the developing and adult rat nervous system is presented. In the embryonic animal the CNS expression is tightly restricted to trigeminal ganglia and, relative to the rest of the embryo, this structure has the highest expression. The expression in the forebrain and cerebellum does not occur until after postnatal day 21 and then is primarily associated with GABAergic interneurons. The highest levels of expression in the adult animal are in the hindbrain, spinal cord, cranial ganglia, and dorsal root ganglia. These nuclei in the hindbrain and periphery that express BP6 are all associated with the coordination of sensorimotor function in the cerebellum, which indicates an important role for the BP6/IGF-II complex in the function and maintenance of these systems.
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Affiliation(s)
- G S Naeve
- Department of Neuroscience, Neurocrine Biosciences, 10555 Science Center Drive, San Diego, CA, USA.
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18
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Bailey JH, Byfield ATJ, Davis PJ, Foster AC, Leech M, Moloney MG, Müller M, Prout CK. On the diastereoselectivity of alkylations of bicyclic lactams. ACTA ACUST UNITED AC 2000. [DOI: 10.1039/b000432o] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Abstract
In humans the regulation of cellular copper homeostasis is essential for proper organ development and function. A novel cytosolic protein, named Atox 1, was recently identified in yeast that functions in shuttling intracellular mononuclear copper [Cu(I)] to copper-requiring proteins. Atox 1 and its human homolog, hAtox1, are members of an emerging family of proteins termed copper chaperones that are involved in the maintenance of copper homeostasis. Northern blot analysis demonstrates that Atox 1 is widely expressed at varying levels in a variety of rat tissues including brain. Using in situ hybridization histochemistry, we characterized the expression profile for the rat homolog of Atox1 (rAtox1) in the normal adult rat brain. There is widespread expression within the brain that appears to be primarily neuronal. The highest levels of Atox1 message consists of distinct neuronal subtypes that are also characterized by their high levels of metals like copper, iron, and zinc, which include the pyramidal neurons of the cerebral cortex and hippocampus in addition to the neurons of the locus coeruleus. The high levels of a metal chaperone like Atox1 in subsets of neurons that also sequester metals suggests that Atox1 may be important in maintaining the functionality of metal requiring enzymes. A detailed analysis of the restricted expression profile for a novel copper chaperone, rAtox1, is described in the adult rat CNS. Further analysis shows that Atoxl expression is associated with neuronal populations that sequester copper.
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Affiliation(s)
- G S Naeve
- Department of Neuroscience, San Diego, CA 92121-1102, USA
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20
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Wiesner JB, Ugarkar BG, Castellino AJ, Barankiewicz J, Dumas DP, Gruber HE, Foster AC, Erion MD. Adenosine kinase inhibitors as a novel approach to anticonvulsant therapy. J Pharmacol Exp Ther 1999; 289:1669-77. [PMID: 10336567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Adenosine levels increase at seizure foci as part of a postulated endogenous negative feedback mechanism that controls seizure activity through activation of A1 adenosine receptors. Agents that amplify this site- and event-specific surge of adenosine could provide antiseizure activity similar to that of adenosine receptor agonists but with fewer dose-limiting side effects. Inhibitors of adenosine kinase (AK) were examined because AK is normally the primary route of adenosine metabolism. The AK inhibitors 5'-amino-5'-deoxyadenosine, 5-iodotubercidin, and 5'-deoxy-5-iodotubercidin inhibited maximal electroshock (MES) seizures in rats. Several structural classes of novel AK inhibitors were identified and shown to exhibit similar activity, including a prototype inhibitor, 4-(N-phenylamino)-5-phenyl-7-(5'-deoxyribofuranosyl)pyrrolo[2, 3-d]pyrimidine (GP683; MES ED50 = 1.1 mg/kg). AK inhibitors also reduced epileptiform discharges induced by removal of Mg2+ in a rat neocortical preparation. Overall, inhibitors of adenosine deaminase or of adenosine transport were less effective. The antiseizure activities of GP683 in the in vivo and in vitro preparations were reversed by the adenosine receptor antagonists theophylline and 8-(p-sulfophenyl)theophylline. GP683 showed little or no hypotension or bradycardia and minimal hypothermic effect at anticonvulsant doses. This improved side effect profile contrasts markedly with the profound hypotension, bradycardia, and hypothermia and greater inhibition of motor function observed with the adenosine receptor agonist N6-cyclopentyladenosine and opens the way to clinical evaluation of AK inhibitors as a novel, adenosine-based approach to anticonvulsant therapy.
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Affiliation(s)
- J B Wiesner
- Metabasis Therapeutics, Inc., San Diego, California, USA.
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21
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Dixon DJ, Foster AC, Ley SV, Reynolds DJ. A general and efficient procedure for the preparation of enantiopure anti-1,2-diols—synthesis and utility of (R ′,R ′,S,R)-2,3-butane diacetal protected butane tetrol. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a902732g] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Dixon DJ, Foster AC, Ley SV, Reynolds DJ. Preparation of desymmetrised meso-tartrate derivatives—synthesis and utility of (R′,R′,R,S)-2,3-butane diacetal protected dimethyl tartrate. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a902733e] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Barlow JS, Dixon DJ, Foster AC, Ley SV, Reynolds DJ. New building blocks for efficient and highly diastereoselective polyol production—synthesis and utility of (R ′,R ′,S,S ) and (S′,S′,R,R)-2,3-butane diacetal protected butane tetrol derivatives. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a902734c] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Tatlisumak T, Takano K, Carano RA, Miller LP, Foster AC, Fisher M. Delayed treatment with an adenosine kinase inhibitor, GP683, attenuates infarct size in rats with temporary middle cerebral artery occlusion. Stroke 1998; 29:1952-8. [PMID: 9731623 DOI: 10.1161/01.str.29.9.1952] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Brain ischemia is associated with a marked increase in extracellular adenosine levels. This results in activation of cell surface adenosine receptors and some degree of neuroprotection. Adenosine kinase is a key enzyme controlling adenosine metabolism. Inhibition of this enzyme enhances the levels of endogenous brain adenosine already elevated as a result of the ischemic episode. We studied a novel adenosine kinase inhibitor (AKI), GP683, in a rat focal ischemia model. METHODS Four groups of 10 adult Sprague-Dawley rats were exposed to 90 minutes of temporary middle cerebral artery (MCA) occlusion. Animals were injected intraperitoneally with vehicle, 0.5 mg/kg, 1.0 mg/kg, or 2.0 mg/kg of GP683 30, 150, and 270 minutes after the induction of ischemia by a researcher blinded to treatment group. The animals were euthanatized 24 hours after MCA occlusion, and brains were stained with 2,3,5-triphenyltetrazolium chloride. We measured brain temperatures in a separate group of 6 rats before and after administration of 1.0 mg/kg GP683. RESULTS All treated groups showed a reduction in infarct volumes, but a significant effect was observed only in the 1.0 mg/kg-dose group (44% reduction, P=0.0077). Body weight, physiological parameters, neurological scores, and mortality did not differ among the 4 groups. No apparent behavioral side effects were observed. Brain temperatures did not change after drug injection. CONCLUSIONS Our results indicate that the use of AKIs offers therapeutic potential and may represent a novel approach to the treatment of acute brain ischemia. The therapeutic effect observed was not caused by a decrease in brain temperature.
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Affiliation(s)
- T Tatlisumak
- Department of Neurology, Helsinki University Central Hospital, Finland.
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25
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Loddick SA, Liu XJ, Lu ZX, Liu C, Behan DP, Chalmers DC, Foster AC, Vale WW, Ling N, De Souza EB. Displacement of insulin-like growth factors from their binding proteins as a potential treatment for stroke. Proc Natl Acad Sci U S A 1998; 95:1894-8. [PMID: 9465113 PMCID: PMC19209 DOI: 10.1073/pnas.95.4.1894] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Insulin-like growth factors I and II (IGF-I and IGF-II) play an important role in normal growth and brain development and protect brain cells from several forms of injury. The effects of IGFs are mediated by type-I and type-II receptors and modulated by potentially six specific binding proteins that form high-affinity complexes with IGFs in blood and cerebrospinal fluid (CSF) and under most circumstances inactivate them. Because brain injury is commonly associated with increases in IGFs and their associated binding proteins, we hypothesized that displacement of this large "pool" of endogenous IGF from the binding proteins would elevate "free" IGF levels to elicit neuroprotective effects comparable to those produced by administration of exogenous IGF. A human IGF-I analog [(Leu24, 59, 60, Ala31)hIGF-I] with high affinity to IGF-binding proteins (Ki = 0.3-3.9 nM) and no biological activity at the IGF receptors (Ki = >10,000 nM) increased the levels of "free, bioavailable" IGF-I in the CSF. Intracerebroventricular administration of this analog up to 1h after an ischemic insult to the rat brain had a potent neuroprotective action comparable to IGF-I. This novel strategy for increasing "free" IGF levels in the brain may be useful for the treatment of stroke and other neurodegenerative diseases.
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Affiliation(s)
- S A Loddick
- Neurocrine Biosciences, Inc., San Diego, CA 92121, USA
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26
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Rowley M, Kulagowski JJ, Watt AP, Rathbone D, Stevenson GI, Carling RW, Baker R, Marshall GR, Kemp JA, Foster AC, Grimwood S, Hargreaves R, Hurley C, Saywell KL, Tricklebank MD, Leeson PD. Effect of plasma protein binding on in vivo activity and brain penetration of glycine/NMDA receptor antagonists. J Med Chem 1997; 40:4053-68. [PMID: 9406596 DOI: 10.1021/jm970417o] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A major issue in designing drugs as antagonists at the glycine site of the NMDA receptor has been to achieve good in vivo activity. A series of 4-hydroxyquinolone glycine antagonists was found to be active in the DBA/2 mouse anticonvulsant assay, but improvements in in vitro affinity were not mirrored by corresponding increases in anticonvulsant activity. Here we show that binding of the compounds to plasma protein limits their brain penetration. Relative binding to the major plasma protein, albumin, was measured in two different ways: by a radioligand binding experiment or using an HPLC assay, for a wide structural range of glycine/NMDA site ligands. These measures of plasma protein binding correlate well (r = 0.84), and the HPLC assay has been used extensively to quantify plasma protein binding. For the 4-hydroxyquinolone series, binding to plasma protein correlates (r = 0.92) with log P (octanol/pH 7.4 buffer) over a range of log P values from 0 to 5. The anticonvulsant activity increases with in vitro affinity, but the slope of a plot of pED50 versus pIC50 is low (0.40); taking plasma protein binding into account in this plot increases the slope to 0.60. This shows that binding to albumin in plasma reduces the amount of compound free to diffuse across the blood-brain barrier. Further evidence comes from three other experiments: (a) Direct measurements of brain/blood ratios for three compounds (2, 16, 26) show the ratio decreases with increasing log R. (b) Warfarin, which competes for albumin binding sites dose-dependently, decreased the ED50 of 26 for protection against seizures induced by NMDLA. (c) Direct measurements of brain penetration using an in situ brain perfusion model in rat to measure the amount of drug crossing the blood-brain barrier showed that compounds 2, 26, and 32 penetrate the brain well in the absence of plasma protein, but this is greatly reduced when the drug is delivered in plasma. In the 4-hydroxyquinolones glycine site binding affinity increases with lipophilicity of the 3-substituent up to a maximum at a log P around 3, then does not improve further. When combined with increasing protein binding, this gives a parabolic relationship between predicted in vivo activity and log P, with a maximum log P value of 2.39. Finally, the plasma protein binding studies have been extended to other series of glycine site antagonists, and its is shown that for a given log P these have similar protein binding to the 4-hydroxyquinolones, except for compounds that are not acidic. The results have implications for the design of novel glycine site antagonists, and it is suggested that it is necessary to either keep log P low or pKa high to obtain good central nervous system activity.
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Affiliation(s)
- M Rowley
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, United Kingdom.
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27
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Wang B, Tang J, White PF, Foster AC, Grettenberger HM, Kopcho J, Wender RH. The effect of GP683, an adenosine kinase inhibitor, on the desflurane anesthetic requirement in dogs. Anesth Analg 1997; 85:675-80. [PMID: 9296430 DOI: 10.1097/00000539-199709000-00035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
UNLABELLED The availability of an analgesic compound devoid of the side effects associated with the commonly used opioid and nonsteroidal antiinflammatory drugs would be useful during the perioperative period. Although adenosine has analgesic and anesthetic-sparing properties, it also produces dose-dependent cardiovascular depression. Inhibitors of adenosine kinase may be able to provide analgesia without producing acute cardiovascular or respiratory depression. This preliminary study investigated the effects of a novel adenosine kinase-inhibiting drug, GP683, on the minimum alveolar anesthetic concentration (MAC) of desflurane in dogs. Seven mongrel dogs were administered one of three different GP683 dose regimens (or the solvent) by intravenous infusion on separate occasions according to a cross-over study design. After determining the baseline desflurane MAC value, GP683 was infused at 75, 150, or 300 microg x kg(-1) x min(-1) for 5 min as a loading dose, followed by 15, 30, or 60 microg x kg(-1) x min(-1) for an additional 85 min to maintain a stable plasma drug level. The desflurane MAC was redetermined 30-90 min after starting the study drug or vehicle infusion, and 30-90 min and 120-180 min after termination of the infusion. Cardiovascular variables and plasma concentrations of GP683 were determined at specific intervals before, during, and after the MAC determinations. The three GP683 dose regimens produced 22%, 31%, and 50% decreases in the desflurane MAC, respectively. In addition, there was good correlation between the decrease in desflurane MAC and the plasma GP683 concentration (r = -0.78). Although the mean arterial pressure (MAP) was decreased up to 25% by the highest infusion rate of GP683, adjustments in the desflurane concentration to an equi-MAC value resulted in normalization of the MAP values. Furthermore, GP683 produced no changes in heart rate. In conclusion, the adenosine kinase-inhibiting drug, GP683, produced dose-dependent decreases in the desflurane MAC of dogs without producing untoward hemodynamic changes. IMPLICATIONS An investigational drug (GP683) that can increase the levels of an important endogenous substance in the body (adenosine) has been found to decrease the anesthetic requirement in dogs without producing adverse effects on the cardiovascular system.
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Affiliation(s)
- B Wang
- Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center at Dallas, 75235-9068, USA
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28
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Carling RW, Leeson PD, Moore KW, Moyes CR, Duncton M, Hudson ML, Baker R, Foster AC, Grimwood S, Kemp JA, Marshall GR, Tricklebank MD, Saywell KL. 4-substituted-3-phenylquinolin-2(1H)-ones: acidic and nonacidic glycine site N-methyl-D-aspartate antagonists with in vivo activity. J Med Chem 1997; 40:754-65. [PMID: 9057862 DOI: 10.1021/jm9605492] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
4-Substituted-3-phenylquinolin-2(1H)-ones have been synthesized and evaluated in vitro for antagonist activity at the glycine site on the NMDA (N-methyl-D-aspartate) receptor and in vivo for anticonvulsant activity in the DBA/2 strain of mouse in an audiogenic seizure model. 4-Amino-3-phenylquinolin-2(1H)-one (3) is 40-fold lower in binding affinity but only 4-fold weaker as an anticonvulsant than the acidic 4-hydroxy compound 1. Methylsulfonylation at the 4-position of 3 gives an acidic compound (6, pKa = 6.0) where affinity is fully restored but in vivo potency is significantly reduced (Table 1). Methylation at the 4-position of 1 to give 18 results in the abolition of measurable affinity, but the attachment of neutral hydrogen bond-accepting groups to the methyl group of 18 produces compounds with comparable in vitro and in vivo activity to 1 (e.g., 23 and 28, Table 2). Replacement of the 4-hydroxy group of 1 with an ethyl group abolishes activity (42), but again, incorporation of neutral hydrogen bond acceptors to the terminal carbon atom restores affinity (e.g., 36, 39, and 40, Table 3). Replacement of the 4-hydroxy group of the high-affinity compound 2 with an amino group produces a compound with 200-fold reduced affinity (43; IC50 = 0.42 microM, Table 4) which is nevertheless still 10-fold higher in affinity than 3. The results in this paper indicate that anionic functionality is not an absolute requirement for good affinity at the glycine/NMDA site and provide compelling evidence for the existence of a ligand/receptor hydrogen bond interaction between an acceptor attached to the 4-position of the ligand and a hydrogen bond donor attached to the receptor.
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Affiliation(s)
- R W Carling
- Department of Medicinal Chemistry, Merck Sharp and Dohme Research Laboratories, Harlow, Essex, UK
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Miller LP, Jelovich LA, Yao L, DaRe J, Ugarkar B, Foster AC. Pre- and peristroke treatment with the adenosine kinase inhibitor, 5'-deoxyiodotubercidin, significantly reduces infarct volume after temporary occlusion of the middle cerebral artery in rats. Neurosci Lett 1996; 220:73-6. [PMID: 8981476 DOI: 10.1016/s0304-3940(96)13234-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The adenosine kinase inhibitor, 5'-deoxyiodotubercidin (5dITU), was examined in a rat focal stoke model with temporary (105 min) middle cerebral artery occlusion (MCAO) followed by a 24 h recovery period. Inhibition of this adenosine metabolizing enzyme indirectly enhances the actions of endogenous adenosine without inducing cardiovascular side effects. Such effects could limit the potential clinical application of any approach targeting adenosine receptor activation. MCAO was accomplished with a transluminal 4-0 nylon suture inserted through the common carotid artery to block blood flow at the origin of the MCA. Treatment with 5dITU 30 min prior to and 5 h after MCAO resulted in a dose dependent (0.1-0.5 mg/kg, i.p.) reduction in infarct volume. A significant (P = 0.02) 44% reduction (control, 265 +/- 35 mm3; treated, 149 +/- 30 mm3) was observed at 0.5 mg/kg. However, at the highest dose examined (1.0 mg/kg) infarct volume was unaffected. To assess the potential for acute (i.e. post-occlusion) treatment, 5dITU was administered (0.33 mg/kg, i.v.) successively at each of 0.5, 1.75 and 3.5 h after MCAO. Post-occlusion treatment resulted in a significant (P = 0.037) 32% reduction in infarct volume (control, 314 +/- 34 mm3; treated, 212 +/- 28 mm3). At this dose there were no apparent changes in a number of physiological parameters monitored over the period of MCAO. The present study shows that intervention with an adenosine kinase inhibitor in an ischemic brain injury model is neuroprotective whether treatment is begun prior to or just after MCAO.
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Affiliation(s)
- L P Miller
- Research Department, Gensia, Inc., San Diego, CA 92121, USA.
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Sajjadi FG, Takabayashi K, Foster AC, Domingo RC, Firestein GS. Inhibition of TNF-alpha expression by adenosine: role of A3 adenosine receptors. J Immunol 1996; 156:3435-42. [PMID: 8617970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Adenosine agonists inhibit TNF-alpha production in macrophage and monocytes, but the mechanism is unknown. Therefore, we studied the human macrophage cell line U937 to determine the adenosine receptor subtypes responsible and the intracellular signaling mechanisms involved. The A1/A3 agonist N6-(4-amino-3-iodobenzyl)adenosine (I-ABA) decreased LPS-stimulated TNF-alpha protein production by 79 +/- 5% (p = 0.003). The mechanism was pretranslational, as adenosine receptor stimulation caused a marked decrease in TNF-alpha mRNA. IL-1 beta, IL-6, and IL-8 mRNA were not changed by adenosine agonists. The rank order of agonists as TNF-alpha inhibitors suggested that the A3 receptor might be involved (N6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-beta-D-ribofuranosyl] adenosine > 2-chloroadenosine > or = I-ABA > N6 benzyl 5'-N-ethylcarboxamidoadenosine (NECA) > NECA > CGS21680 > N6-cyclohexyladenosine), and this was supported by the fact that a mixed A1/A3 antagonist (xanthine amine congener) reversed the effect, whereas A1-specific (1,3-dipropyl-8-cyclopentylxanthine) and A2-specific (3,7-dimethyl-1-propargylxanthine) antagonists did not. Receptor signaling did not involve cAMP or protein kinase A, nor did it alter the activation and binding characteristics of the transcription factor NF-kappa B. However, the composition of the AP-1 transcription complex was altered by I-ABA. These data suggest that stimulation of the A3 adenosine receptor can alter the cytokine milieu by decreasing TNF-alpha. Adenosine agonists or adenosine regulating agents have potential therapeutic uses in acute and chronic inflammatory diseases.
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31
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Sajjadi FG, Takabayashi K, Foster AC, Domingo RC, Firestein GS. Inhibition of TNF-alpha expression by adenosine: role of A3 adenosine receptors. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.156.9.3435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Adenosine agonists inhibit TNF-alpha production in macrophage and monocytes, but the mechanism is unknown. Therefore, we studied the human macrophage cell line U937 to determine the adenosine receptor subtypes responsible and the intracellular signaling mechanisms involved. The A1/A3 agonist N6-(4-amino-3-iodobenzyl)adenosine (I-ABA) decreased LPS-stimulated TNF-alpha protein production by 79 +/- 5% (p = 0.003). The mechanism was pretranslational, as adenosine receptor stimulation caused a marked decrease in TNF-alpha mRNA. IL-1 beta, IL-6, and IL-8 mRNA were not changed by adenosine agonists. The rank order of agonists as TNF-alpha inhibitors suggested that the A3 receptor might be involved (N6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-beta-D-ribofuranosyl] adenosine > 2-chloroadenosine > or = I-ABA > N6 benzyl 5'-N-ethylcarboxamidoadenosine (NECA) > NECA > CGS21680 > N6-cyclohexyladenosine), and this was supported by the fact that a mixed A1/A3 antagonist (xanthine amine congener) reversed the effect, whereas A1-specific (1,3-dipropyl-8-cyclopentylxanthine) and A2-specific (3,7-dimethyl-1-propargylxanthine) antagonists did not. Receptor signaling did not involve cAMP or protein kinase A, nor did it alter the activation and binding characteristics of the transcription factor NF-kappa B. However, the composition of the AP-1 transcription complex was altered by I-ABA. These data suggest that stimulation of the A3 adenosine receptor can alter the cytokine milieu by decreasing TNF-alpha. Adenosine agonists or adenosine regulating agents have potential therapeutic uses in acute and chronic inflammatory diseases.
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Badgwell M, Swan J, Foster AC. Volume-controlled ventilation is made possible in infants by using compliant breathing circuits with large compression volume. Anesth Analg 1996; 82:719-23. [PMID: 8615486 DOI: 10.1097/00000539-199604000-00007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We studied the weight dependency of set tidal volume (VTset) during volume-controlled ventilation of 80 infants (ASA physical status I-IV, 0.7-20 kg), including prematures, neonates, and exprematures, who were anesthetized for major and minor surgery, including abdominal, thoracic, and neurosurgical procedures. After neuromuscular blockade and endotracheal intubation, infant's lungs were ventilated with an Ohmeda 7800 volume-limited ventilator and either a pediatric or adult circle breathing system (PC or AC) or a Bain circuit (Ba) and a pediatric- or adult-sized bellows (PB or AB). Except for larger and older infants in the ACAB group, body weight, age, peak inspiratory pressure (PIP), ETCO2, and SPO2 did not differ among groups. Compression volume loss was large in the five circuits tested. We found that VTset/kg varied with weight in a curvilinear relationship where y represents volume added and x represents PIP (y = 175.02x-0.87; r2 - 0.87), whereby VTset is approximately 150-200 mL/kg for a 1-kg infant and approximately 25 mL/kg for infants > or = 10 kg. Ventilation was adequate in each infant, except for one with extremely poor pulmonary compliance. We conclude that large compression volumes associated with compliant breathing systems make possible the use of volume-controlled ventilators in small infants.
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Affiliation(s)
- M Badgwell
- Department of Anesthesiology, Texas Tech University Health Sciences Center, Lubbock 79430, USA
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Grimwood S, Kulagowski JJ, Mawer IM, Rowley M, Leeson PD, Foster AC. Allosteric modulation of the glutamate site on the NMDA receptor by four novel glycine site antagonists. Eur J Pharmacol 1995; 290:221-6. [PMID: 7589216 DOI: 10.1016/0922-4106(95)00081-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using radioligand binding studies, we have investigated the binding properties of four 4-hydroxy-2-quinolones, a novel series of selective antagonists for the glycine site on the N-methyl-D-aspartate (NMDA) receptor. L-701,324, L-703,717, L-698,532 and L-695,902 inhibited [3H]L-689,560 (glycine site antagonist) binding to rat cortex/hippocampus P2 membranes with IC50 values of 1.97, 4.47, 209 and 6448 nM, respectively, whilst also inhibiting non-equilibrium [3H]dizocilpine binding to the NMDA receptor ion-channel. All four compounds partially inhibited L-[3H]glutamate (approximately 50% inhibition; agonist) binding and enhanced [3H]cis-4-phosphonomethyl-2-piperidine carboxylate ([3H]CGS-19755; 41-81% enhancement; 'C-5' antagonist) and [3H]3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonate ([3H]CPP; 28-66% enhancement; 'C-7' antagonist) binding to the glutamate recognition site of the NMDA receptor with EC50 values similar to those observed for [3H]L-689,560 binding. These results provide further evidence for allosteric interactions between the glutamate and glycine recognition sites of the NMDA receptor complex, and as the 4-hydroxy-2-quinolones are 'full' antagonists at the glycine site, indicate that these interactions are not caused by the intrinsic activity of a compound.
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Affiliation(s)
- S Grimwood
- Merck, Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK
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34
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Foster AC, Miller LP, Wiesner JB. Regulation of endogenous adenosine levels in the CNS: potential for therapy in stroke, epilepsy and pain. Adv Exp Med Biol 1995; 370:427-30. [PMID: 7660943 DOI: 10.1007/978-1-4615-2584-4_92] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- A C Foster
- Department of CNS Pharmacology, Gensia, Inc., San Diego, CA 92121, USA
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35
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Kulagowski JJ, Baker R, Curtis NR, Leeson PD, Mawer IM, Moseley AM, Ridgill MP, Rowley M, Stansfield I, Foster AC. 3'-(Arylmethyl)- and 3'-(aryloxy)-3-phenyl-4-hydroxyquinolin-2(1H)-ones: orally active antagonists of the glycine site on the NMDA receptor. J Med Chem 1994; 37:1402-5. [PMID: 8182696 DOI: 10.1021/jm00036a002] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J J Kulagowski
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Terlings Park, Harlow, Essex, U.K
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36
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Quirk K, Foster AC, McKernan RM. Characterization of the solubilized NMDA receptor complex from rat brain with [3H]L-689,560, a glycine site antagonist. Mol Membr Biol 1994; 11:17-21. [PMID: 7912609 DOI: 10.3109/09687689409161025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An antagonist ligand for the glycine site of the NMDA receptor, [3H]L-689,560, has recently been described. We have investigated the use of this ligand to label NMDA receptors which have been solubilized from rat brain. It has significant advantages over [3H]dizocilpine ([3H]MK-801) for this purpose since (a) it is not inhibited by most detergents, (b) interactions between the glutamate and glycine sites are maintained, and (c) equilibrium binding is rapid and of high affinity (Kd = 8.8 +/- 1.9 nM, n = 4). Nevertheless, precautions must be taken to remove glycine throughout all experimental procedures. In addition we have investigated the ability of NMDA receptors to bind to various lectins and conclude that only N-linked glycosylation is present, consistent with consensus sequences for glycosylation present in cloned subunits of the NMDA receptor. Further binding of the radioligand [3H]L-689,560 was detected both to the solubilized receptor and to receptor immobilized on lectin-agarose, identifying it as an appropriate ligand for use in the characterization of NMDA receptors during purification procedures.
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Affiliation(s)
- K Quirk
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK
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37
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Abstract
The N-methyl-D-aspartate (NMDA) receptor complex possesses distinct recognition sites for glutamate, glycine and polyamines, which appear to be allosterically linked. We have investigated the effects of polyamines on the binding of the glycine site antagonist [3H](+/-)-4-(trans)-2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino - 1,2,3,4-tetrahydroquinoline ([3H]L-689,560), using rat cortex/hippocampus P2 membranes. Spermine and spermidine partially inhibited [3H]L-689,560 binding under non-equilibrium conditions, with IC50 values of 25.9 and 106 microM, respectively. The putative polyamine site antagonists arcaine, 1,10-diaminodecane, diethylenetriamine and putrescine had no effect on [3H]L-689,560 binding per se at 1 mM. The inhibition of [3H]L-689,560 binding by spermine was antagonised by arcaine in a competitive manner, but not by 1,10-diaminodecane, diethylenetriamine or putrescine. Kinetic analysis revealed that spermine (100 microM) decreased the association and dissociation rates of [3H]L-689,560 binding. In saturation experiments 100 microM spermine increased the KD for [3H]L-689,560 binding from 1.99 nM to 4.03 nM, with no effect on the number of binding sites. Spermine increased the affinity of glycine site agonists in displacing [3H]L-689,560 binding, with no effect on inhibition by partial agonists or antagonists, suggesting that spermine promotes an 'agonist-preferring' state. Modulation of [3H]L-689,560 binding by agonists for the polyamine and glutamate sites on the NMDA receptor did not appear to be additive in nature.
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Affiliation(s)
- S Grimwood
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK
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Carling RW, Leeson PD, Moore KW, Smith JD, Moyes CR, Mawer IM, Thomas S, Chan T, Baker R, Foster AC. 3-Nitro-3,4-dihydro-2(1H)-quinolones. Excitatory amino acid antagonists acting at glycine-site NMDA and (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. J Med Chem 1993; 36:3397-408. [PMID: 8230130 DOI: 10.1021/jm00074a021] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
3,4-Dihydro-2(1H)-quinolones, evolved from 2-carboxy-1,2,3,4,- tetrahydroquinolines and 3-carboxy-4-hydroxy-2(1H)-quinolones, have been synthesized and evaluated in vitro for antagonist activity at the glycine site on the NMDA receptor and for AMPA [(RS)-alpha-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid] antagonist activity. Generally poor potency at the glycine site is observed when a variety of electron-withdrawing substituents are attached to the 3-position of 3,4-dihydro-2(1H)-quinolones. The analogues 5-9 (IC50 values > 100 microM, Table I) exist largely in the 3,4-dipseudoaxial conformation (as evidenced by 1H NMR spectra), whereas the 3-cyano derivative (10, IC50 = 12.0 microM) has a relatively high population of the 3-pseudoequatorial conformer. The 3-nitro analogue (4, IC50 = 1.32 microM) has a pKa approximately 5 and thus exists at physiological pH as an anion with the nitro group planar to the quinolone ring. The general requirement of acidity for high affinity binding at the glycine/NMDA site is supported with the good activity of the other 3-nitro derivatives (13-21), all of which are deprotonated at physiological pH. The 3-nitro-3,4-dihydro-2(1H)-quinolones and 2-carboxy-1,2,3,4-tetrahydroquinolines show quite different structure-activity relationships at the 4-position. The unselective excitatory amino acid activity of 21 is comparable with 6,7-dichloro-quinoxaline-2,3-dione and 6,7-dichloroquinoxalic acid and this suggests similarities in their modes of binding to excitatory amino acid receptors. The broad spectrum excitatory amino acid antagonist activity of the 4-unsubstituted analogue 21 (KbNMDA = 6.7 microM, KbAMPA = 9.2 microM) and the glycine/NMDA selectivity of the other 3-nitro derivatives allows the proposal of a model for AMPA receptor binding which differs from the glycine binding pharmacophore in that there is bulk intolerance adjacent to the 4-position. Compound 21 (L-698,544) is active (ED50 = 13.2 mg/kg) in the DBA/2 mouse anticonvulsant model and is the most potent combined glycine/NMDA-AMPA antagonist yet reported, in vivo, and may prove to be a useful pharmacological tool.
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Affiliation(s)
- R W Carling
- Department of Medicinal Chemistry, Merck Sharp and Dohme Research Laboratories, Harlow, Essex, U.K
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Abstract
The cellular elements responsible for the uptake of [3H]glycine into rat hippocampal slices were investigated. The diffuse laminar distribution of labelling observed under control conditions was greatly reduced seven days after intrahippocampal injection of a neurotoxic dose of quinolinic acid, suggesting a neuronal localization. Glycine was also taken up into glial cells, since dense clusters of silver grains were present on small sized cells throughout the hippocampus which were apparently increased in number after the lesion. The pattern of [3H]glycine uptake into rat cerebral cortex and cerebellar slices was also consistent with both neuronal and glial localization. These glycine transport sites may be strategically located to control excitatory neurotransmission mediated by the N-methyl-D-aspartate sub-type of glutamate receptors.
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Affiliation(s)
- E Fedele
- Merck Sharp and Dohme Research Laboratories Neuroscience Research Centre, Harlow, Essex, UK
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40
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Grimwood S, Wilde GJ, Foster AC. Interactions between the glutamate and glycine recognition sites of the N-methyl-D-aspartate receptor from rat brain, as revealed from radioligand binding studies. J Neurochem 1993; 60:1729-38. [PMID: 8097236 DOI: 10.1111/j.1471-4159.1993.tb13397.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The N-methyl-D-aspartate (NMDA) receptor possesses two distinct amino acid recognition sites, one for glutamate and one for glycine, which appear to be allosterically linked. Using rat cortex/hippocampus P2 membranes we have investigated the effect of glutamate recognition site ligands on [3H]glycine (agonist) and (+-)-4-trans-2-carboxy-5,7-dichloro-4- [3H]phenylaminocarbonylamino-1,2,3,4-tetrahydroquinoline ([3H]L-689,560; antagonist) binding to the glycine site and the effect of glycine recognition site ligands on L-[3H]glutamate (agonist), DL-3-(2-carboxypiperazin-4-yl)-[3H]propyl-1-phosphonate ([3H]CPP; "C-7" antagonist), and cis-4-phosphonomethyl-2-[3H]piperidine carboxylate ([3H]CGS-19755; "C-5" antagonist) binding to the glutamate site. "C-7" glutamate site antagonists partially inhibited [3H]L-689,560 binding but had no effect on [3H]glycine binding, whereas "C-5" antagonists partially inhibited the binding of both radioligands. Glycine, D-serine, and D-cycloserine partially inhibited [3H]CGS-19755 binding but had little effect on L-[3H]glutamate or [3H]CPP binding, whereas the partial agonists (+)-3-amino-1-hydroxypyrrolid-2-one [(+)-HA-966], 3R-(+)cis-4-methyl-HA-966 (L-687,414), and 1-amino-1-carboxycyclobutane all enhanced [3H]CPP binding but had no effect on [3H]CGS-19755 binding, and (+)-HA-966 and L-687,414 inhibited L-[3H]glutamate binding. The association and dissociation rates of [3H]L-689,560 binding were decreased by CPP and D-2-amino-5-phosphonopentanoic acid ("C-5"). Saturation analysis of [3H]L-689,560 binding sites. These results indicate that complex interactions occur between the glutamate and glycine recognition sites on the NMDA receptor. In addition, mechanisms other than allosterism may underlie some effects, and the possibility of a steric interaction between CPP and [3H]L-689,560 is discussed.
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Affiliation(s)
- S Grimwood
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, England
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41
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Fedele E, Foster AC. An evaluation of the role of extracellular amino acids in the delayed neurodegeneration induced by quinolinic acid in the rat striatum. Neuroscience 1993; 52:911-7. [PMID: 8095713 DOI: 10.1016/0306-4522(93)90537-p] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of the N-methyl-D-aspartate receptor agonist quinolinic acid on extracellular levels of striatal amino acids, following its injection directly into the rat striatum, has been investigated using intracerebral dialysis in the attempt to elucidate the cellular mechanisms underlying delayed neurodegeneration. A neurotoxic dose (200 nmol) of quinolinic acid caused an elevation in the levels of aspartate (x 6), glutamate (x 2), asparagine (x 2), serine (x 2.5), glycine (x 3), and threonine (x 2) which peaked in the fractions 20-40 min after the injection and achieved statistical significance for aspartate and asparagine. The dialysate content of these amino acids returned to basal values within 1 h and no further changes were observed in the following 4 h. Injection of an equivalent dose of nicotinic acid did not mimic the effect of quinolinate, indicating that osmotic and/or mechanical damage was not responsible for the observed phenomena. Pretreatment with the N-methyl-D-aspartate receptor channel blocker dizocilpine (MK-801) completely blocked the quinolinate-induced increase of the amino acids, thus confirming that N-methyl-D-aspartate receptor activation is required for this effect to occur. Seven days after the injection of quinolinate, histological analysis showed an extensive loss of neuronal elements in the injected striatum, which was completely prevented in the dizocilpine-treated animals. Sections from striata of animals injected with nicotinic acid showed normal-appearing neurons and no differences were detectable from controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Fedele
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, U.K
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Pangalos MN, Francis PT, Foster AC, Pearson RC, Middlemiss DN, Bowen DM. NMDA receptors assessed by autoradiography with [3H]L-689,560 are present but not enriched on corticofugal-projecting pyramidal neurones. Brain Res 1992; 596:223-30. [PMID: 1361417 DOI: 10.1016/0006-8993(92)91551-o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Experimental lesions followed by binding of [3H]4-trans-2-carboxy-5,7-dichloro-4-phenylamino-carbonylamino-1,2 ,3,4- tetrahydroquinoline ([3H]L-689,560, a novel ligand that binds to the glycine modulatory site), [3H]glycine and [3H]glutamate (N-methyl-D-aspartate (NMDA) sensitive) to cryostat sections and quantitative autoradiography were used to investigate the cellular localization of the NMDA receptor complex in the neocortex of the rat. The lesions were produced by intrastriatal injections of either volkensin (2 and 6 ng) or ricin (10 ng): both are suicide transport agents but only the former is retrogradely transported in the CNS. The binding of [3H]L-689,560 was significantly reduced in rats receiving 2 or 6 ng volkensin in deep cortical layers of Fr1/Fr2 ipsilateral to the striatal lesion. Similar reductions were also seen in [3H]glycine and [3H]glutamate binding, but only in rats receiving 6 ng volkensin. Quantitative histological analysis had previously revealed a loss of large infragranular pyramidal neurones with sparing of both interneurones and supragranular pyramidal neurones. There were no significant reductions in binding of any ligand in the superficial layers. In cortical areas Par1/Par2, [3H]L-689,560 was also significantly reduced in deep layers but only in rats receiving 6 ng volkensin. Binding was also reduced in the superficial layers by contrast to Fr1/Fr2. [3H]Glycine and [3H]glutamate binding were unaffected in this area. Binding of [3H]L-689,560 was unaffected in any area following intrastriatal ricin injection. The present study indicates that the NMDA receptor complex is present on pyramidal cells forming the corticofugal pathways. This is discussed in terms of the 5-HT1A receptor which is enriched on these cells.
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Affiliation(s)
- M N Pangalos
- Miriam Marks Department of Neurochemistry, Institute of Neurology, London, UK
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43
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Carling RW, Leeson PD, Moseley AM, Baker R, Foster AC, Grimwood S, Kemp JA, Marshall GR. 2-Carboxytetrahydroquinolines. Conformational and stereochemical requirements for antagonism of the glycine site on the NMDA receptor. J Med Chem 1992; 35:1942-53. [PMID: 1534583 DOI: 10.1021/jm00089a003] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
2-Carboxy-1,2,3,4-tetrahydroquinoline derivatives, derived from kynurenic acid, have been synthesized and evaluated for in vitro antagonist activity at the glycine site on the NMDA receptor. 2,3-Dihydrokynurenic acids show reduced potency relative to the parent lead compounds (Table I) possibly as a result of conformational effects. Removal of the 4-oxo group results in further reduced potency, but introduction of a cis-carboxymethyl group to the 4-position restores antagonist activity (Tables III and IV). Replacement of the keto group of 5,7-dichloro-2,3-dihydrokynurenic acid with other alternative H-bonding groups, for example cis- and trans-benzyloxycarbonyl and cis- and trans-carboxamido (Table V), gives comparable activity, but there is negligible stereoselectivity. A significant increase in potency and stereoselectivity is seen within the 4-acetate series (Table VI). The trans-4-acetic acid is significantly more potent than the corresponding lead kynurenic acid and has 100-fold greater affinity than the cis isomer. The results are consistent with a requirement in binding for a pseudoequatorially placed 2-carboxylate and clearly demonstrate the importance for binding of a correctly positioned hydrogen-bond-accepting group at the 4-position. The high-affinity binding of an anionic group in the 4-substituent binding pocket suggests that the glycine site and the neurotransmitter recognition (NMDA) site may have some features in common.
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Affiliation(s)
- R W Carling
- Department of Medicinal Chemistry, Merck Sharp and Dohme Research Laboratories, Harlow, Essex, UK
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44
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Leeson PD, Carling RW, Moore KW, Moseley AM, Smith JD, Stevenson G, Chan T, Baker R, Foster AC, Grimwood S. 4-Amido-2-carboxytetrahydroquinolines. Structure-activity relationships for antagonism at the glycine site of the NMDA receptor. J Med Chem 1992; 35:1954-68. [PMID: 1534584 DOI: 10.1021/jm00089a004] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
trans-2-Carboxy-5,7-dichloro-4-amidotetrahydroquinolines, evolved from the lead 5,7-dichlorokynurenic acid, have been synthesized and tested for in vitro antagonist activity at the glycine site on the N-methyl-D-aspartate (NMDA) receptor. Optimization of the 4-substituent has provided antagonists having nanomolar affinity, including the urea trans-2-carboxy-5,7-dichloro-4[[(phenylamino)carbonyl]amino]-1,2,3, 4-tetrahydroquinoline (35; IC50 = 7.4 nM vs [3H]glycine binding; Kb = 130 nM for block of NMDA responses in the rat cortical slice), which is one of the most potent NMDA antagonists yet found. The absolute stereochemical requirements for binding were found to be 2S,4R, showing that, in common with other glycine-site NMDA receptor ligands, the unnatural configuration at the alpha-amino acid center is required. The preferred conformation of the trans-2,4-disubstituted tetrahydroquinoline system, as shown by X-ray crystallography and 1H NMR studies, places the 2-carboxyl pseudoequatorial and the 4-substituent pseudoaxial. Modifications of the 4-amide show that bulky substituents are tolerated and reveal the critical importance for activity of correct positioning of the carbonyl group. The high affinity of trans-2-carboxy-5,7-dichloro-4-[1-(3-phenyl-2-oxoimidazolidinyl)]- 1,2,3,4-tetrahydroquinoline (55; IC50 = 6 nM) suggests that the Z,Z conformer of the phenyl urea moiety in 35 is recognized by the receptor. Molecular modeling studies show that the 4-carbonyl groups of the kynurenic acids, the tetrahydroquinolines, and related antagonists based on N-(chlorophenyl)glycine, can interact with a single putative H-bond donor on the receptor. The results allow the establishment of a three-dimensional pharmacophore of the glycine receptor antagonist site, incorporating a newly defined bulk tolerance/hydrophobic region.
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Affiliation(s)
- P D Leeson
- Department of Medicinal Chemistry, Merck Sharp and Dohme Research Laboratories, Harlow, Essex
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45
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Foster AC, Kemp JA, Leeson PD, Grimwood S, Donald AE, Marshall GR, Priestley T, Smith JD, Carling RW. Kynurenic acid analogues with improved affinity and selectivity for the glycine site on the N-methyl-D-aspartate receptor from rat brain. Mol Pharmacol 1992; 41:914-22. [PMID: 1375317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The glycine site on the N-methyl-D-aspartate (NMDA) subtype of receptors for the excitatory neurotransmitter glutamate is a potential target for the development of neuroprotective drugs. We report here two chemical series of glycine site antagonists derived from kynurenic acid (KYNA), with greatly improved potency and selectivity. Disubstitution with chlorine or bromine in the 5- and 7-positions of KYNA increased affinity for [3H]glycine binding sites in rat cortex/hippocampus P2 membranes, with a parallel increase of potency for antagonism of NMDA-evoked responses in the rat cortical wedge preparation. The optimal compound was 5-I,7-Cl-KYNA, with an IC50 for [3H]glycine binding of 29 nM and an apparent Kb in the cortical wedge preparation of 0.41 microM. Reduction of the right-hand ring of 5,7-diCl-KYNA reduced affinity by 10-fold, but this was restored by substitution in the 4-position with the trans-phenylamide and further improved in the trans-benzylamide. The optimal compound was the transphenylurea (L-689,560), with an IC50 of 7.4 nM and an apparent Kb of 0.13 microM. Both series of compounds displayed a high degree of selectivity for the glycine site, having IC50 values of greater than 10 microM versus radioligand binding to the glutamate recognition sites of NMDA, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), and kainate receptors and the strychnine-sensitive glycine receptor. Selectivity versus AMPA receptor-mediated responses was also apparent in the rat cortical wedge and in patch-clamp recordings of cortical neurons in culture. Experiments using [3H]dizocilpine (MK-801) binding indicated that 5,7-diBr-KYNA, 5,7-diCl-KYNA, 5-I,7-Cl-KYNA, and L-689,560 all behaved as full antagonists and were competitive with glycine. Patch-clamp recordings of cortical neurons in culture also indicated that NMDA-induced currents were antagonized by competition for the glycine site, and gave no evidence for partial agonist activity. pKi values for 5,7-diBr-KYNA and L-689,560 in these experiments were 7.2 and 7.98, respectively, similar to the affinities of these compounds in the glycine binding assay. The high affinity and selectivity of these new derivatives make them useful tools to investigate the function of the glycine site on the NMDA receptor.
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Affiliation(s)
- A C Foster
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK
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Iversen L, Foster AC, Hill RG, Iversen SD, Kemp JA, Leeson PD, Rupniak NM, Saywell K, Tricklebank MD, Williams BJ. Neurotoxin-Related Research: From the Laboratory to the Clinic. Ann N Y Acad Sci 1992; 648:207-18. [PMID: 1353328 DOI: 10.1111/j.1749-6632.1992.tb24540.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L Iversen
- Merck Sharp & Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, England
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47
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Grimwood S, Moseley AM, Carling RW, Leeson PD, Foster AC. Characterization of the binding of [3H]L-689,560, an antagonist for the glycine site on the N-methyl-D-aspartate receptor, to rat brain membranes. Mol Pharmacol 1992; 41:923-30. [PMID: 1375318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The binding characteristics of [3H]L-689,560 [(+/-)-4-(trans)-2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino -1,2,3,4- tetrahydroquinoline], a selective antagonist for the glycine site on the N-methyl-D-aspartate receptor, have been evaluated using rat cortex/hippocampus P2 membranes. Specific [3H]L-689,560 binding was saturable, having a Kd of 2.97 nM and a Bmax of 4.15 pmol/mg of protein. The Bmax value was not significantly different from that obtained for [3H]glycine in the same membrane preparation, and L-689,560 and glycine were found to be mutually competitive. The specific binding of [3H]L-689,560 (1 nM) represented 96 +/- 0.02% (four experiments) of total binding. Association experiments at 4 degrees revealed that [3H]L-689,560 reached equilibrium in 120 min, with a t1/2 of 40 min. The dissociation of [3H]L-689,560 was slow at 4 degrees (t1/2 = 118 min), allowing the use of filtration to separate free from bound radioactivity. Both association and dissociation curves were best fitted by a double-exponential function, suggesting the presence of two components. Comparison of IC50 values obtained using [3H]glycine and [3H]L-689,560 binding for 21 glycine site ligands (including agonists, partial agonists, and antagonists, with affinities spanning 5 orders of magnitude) showed a 1:1 correlation, with a correlation coefficient of 0.97. This suggests that efficacy does not have a large influence on the affinity of glycine site ligands when an agonist or antagonist radioligand is used. Ligands for other amino acid recognition sites did not directly inhibit [3H]L-689,560 binding. [3H]L-689,560 is an improved radioligand for the glycine site that will facilitate further investigations of its properties.
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Affiliation(s)
- S Grimwood
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK
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48
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Abstract
The uptake of [3H]glycine by rat hippocampal tissue in vitro has been characterized. [3H]Glycine transport into a crude synaptosomal (P2) fraction was resolved into two components. The high affinity component (Km = 21 +/- 5.4 microM, Vmax = 490 +/- 234 pmol/3 min/mg protein) was almost completely sodium dependent whereas the low affinity component (Km = 2.214 +/- 0.958 mM, Vmax = 13.9 +/- 0.5 nmol/3 min/mg protein) was partially dependent on sodium ions. Amongst a range of amino acids, only L-serine, L-glutamate, L-proline, histidine and glycine itself inhibited [3H]glycine uptake at 1 mM. The autoradiographic localization of [3H]glycine uptake in rat hippocampal slices revealed a general pattern of labeling in dendritic regions with a sparing of pyramidal and granule neuron cell bodies. However, a laminar distribution was apparent since the amino acid was preferentially accumulated in the hilus of the dentate gyrus, in the stratum lacunosum-moleculare, in the alveus and in the molecular layer of the lower blade of the dentate gyrus. A diffuse pattern of accumulation was apparent in these areas along with dense clusters of silver grains. The clusters were associated with small cell bodies and might represent glycine uptake into astrocytes. Glycine transport mechanisms may influence the modulatory effects of this amino acid on N-methyl-D-aspartate receptor-mediated neurotransmission in the hippocampus.
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Affiliation(s)
- E Fedele
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow U.K
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McKnight AT, Maguire JJ, Elliott NJ, Fletcher AE, Foster AC, Tridgett R, Williams BJ, Longmore J, Iversen LL. Pharmacological specificity of novel, synthetic, cyclic peptides as antagonists at tachykinin receptors. Br J Pharmacol 1991; 104:355-60. [PMID: 1665732 PMCID: PMC1908569 DOI: 10.1111/j.1476-5381.1991.tb12435.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
1. The interaction at tachykinin receptors of a series of novel cyclic hexapeptides has been examined by use of radioligand binding assays (NK1 and NK3 sites in rat cortex, NK2 sites in hamster urinary bladder) and functional pharmacological assays (guinea-pig ileum, rat vas deferens and rat portal vein for NK1, NK2 and NK3 receptors, respectively). 2. The compounds cyclo(GlnTrpPhe(R)Gly[ANC-2]LeuMet) (L-659,837) and cyclo(GlnTrpPheGly-LeuMet) (L-659,877) were powerful and selective displacers of NK2 binding (pIC50 6.9 and 8.0, respectively), and were competitive antagonists of responses to stimulation of NK2 receptors in rat vas deferens (pKB for antagonism of responses to eledoisin 6.7 and 8.1, respectively). Responses in the NK1 and NK3 pharmacological assays were blocked only weakly, if at all. 3. In the longitudinal muscle of the small intestine of the rat, responses to stimulation of the putative NK2 receptor by eledoisin, neurokinin A or neurokinin B were antagonized by both cyclo(GlnTrpPhe(R)-Gly[ANC-2]LeuMet) and cyclo (GlnTrpPheGlyLeuMet) in a manner consistent with the presence in this tissue of a uniform population of receptors, indistinguishable from the NK2 receptor of the rat vas deferens. 4. The compounds cyclo(GlnTrpPheGlyLeuMet) and the lactam-containing analogue are among the most selective antagonists for the NK2 receptor that have been described; their availability should be of value in the characterization of the receptors mediating responses to tachykinins, and in elucidating the physiological functions of the tachykinin receptors.
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Affiliation(s)
- A T McKnight
- Merck Sharp & Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex
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50
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Bakker MH, McKernan RM, Wong EH, Foster AC. [3H]MK-801 binding to N-methyl-D-aspartate receptors solubilized from rat brain: effects of glycine site ligands, polyamines, ifenprodil, and desipramine. J Neurochem 1991; 57:39-45. [PMID: 1828832 DOI: 10.1111/j.1471-4159.1991.tb02096.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The N-methyl-D-aspartate (NMDA) receptor is thought to contain several distinct binding sites that can regulate channel opening. In the present experiments, the effects of ligands for these sites have been examined on [3H]MK-801 binding to a soluble receptor preparation, which had been passed down a gel filtration column to reduce the levels of endogenous small-molecular-weight substances. Glycine site agonists, partial agonists, and antagonists gave effects similar to those observed in membranes [EC50 values (in microM): glycine, 0.31; D-serine, 0.20; D-cycloserine, 1.46; (+)-HA-966, 4.06; and 7-chlorokynurenic acid, 1.81]. Spermine and spermidine enhanced [3H]MK-801 binding to the soluble receptor preparation (EC50, 4.3 and 20.1 microM, respectively), whereas putrescine and cadaverine gave small degrees of inhibitions. When spermine and spermidine were tested under conditions where [3H]MK-801 binding approached equilibrium, their ability to enhance [3H]MK-801 binding was much reduced, a result suggesting that the polyamines increase the rate to equilibrium. Putrescine antagonised the effects of spermine. Ifenprodil reduced [3H]MK-801 binding under both equilibrium and nonequilibrium conditions, although the high-affinity component of inhibition described in membranes was not observed. Ifenprodil antagonised spermine effects in an apparently noncompetitive manner. Desipramine was able to give total inhibition of specific [3H]MK-801 binding under nonequilibrium conditions with an IC50 of 4 microM, and this value was unaltered when [3H]MK-801 binding was allowed to reach equilibrium. These results suggest that the sites mediating the effects of glycine and its analogues, polyamines and desipramine are integral components of the NMDA receptor protein.
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Affiliation(s)
- M H Bakker
- Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, England, U.K
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