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Chandran J, Chowdhury EA, Perkinton M, Jamier T, Sutton D, Wu S, Dobson C, Shah DK, Chessell I, Meno-Tetang GML. Assessment of AAV9 distribution and transduction in rats after administration through Intrastriatal, Intracisterna magna and Lumbar Intrathecal routes. Gene Ther 2023; 30:132-141. [PMID: 35637286 DOI: 10.1038/s41434-022-00346-1] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/12/2022] [Accepted: 05/11/2022] [Indexed: 11/09/2022]
Abstract
Challenges in obtaining efficient transduction of brain and spinal cord following systemic AAV delivery have led to alternative administration routes being used in clinical trials that directly infuse the virus into the CNS. However, data comparing different direct AAV injections into the brain remain limited making it difficult to choose optimal routes. Here we tested both AAV9-egfp and AAV9-fLuc delivery via intrastriatal (IST), intracisterna magna (ICM) and lumbar intrathecal (LIT) routes in adult rats and assessed vector distribution and transduction in brain, spinal cord and peripheral tissues. We find that IST infusion leads to robust transgene expression in the striatum, thalamus and cortex with lower peripheral tissue transduction and anti-AAV9 capsid titers compared to ICM or LIT. ICM delivery provided strong GFP and luciferase expression across more brain regions than the other routes and similar expression in the spinal cord to LIT injections, which itself largely failed to transduce the rat brain. Our data highlight the strengths and weaknesses of each direct CNS delivery route which will help with future clinical targeting.
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Affiliation(s)
- Jayanth Chandran
- Discovery Sciences, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ekram Ahmed Chowdhury
- Department of Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, USA
| | | | - Tanguy Jamier
- Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Daniel Sutton
- Clinical Pharmacology and Safety Science, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Shengjia Wu
- Department of Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Claire Dobson
- Discovery Sciences, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Dhaval K Shah
- Department of Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Iain Chessell
- Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
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2
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Koychev I, Lawson J, Chessell T, Mackay C, Gunn R, Sahakian B, Rowe JB, Thomas AJ, Rochester L, Chan D, Tom B, Malhotra P, Ballard C, Chessell I, Ritchie CW, Raymont V, Leroi I, Lengyel I, Murray M, Thomas DL, Gallacher J, Lovestone S. Deep and Frequent Phenotyping study protocol: an observational study in prodromal Alzheimer's disease. BMJ Open 2019; 9:e024498. [PMID: 30904851 PMCID: PMC6475176 DOI: 10.1136/bmjopen-2018-024498] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Recent failures of potential novel therapeutics for Alzheimer's disease (AD) have prompted a drive towards clinical studies in prodromal or preclinical states. However, carrying out clinical trials in early disease stages is extremely challenging-a key reason being the unfeasibility of using classical outcome measures of dementia trials (eg, conversion to dementia) and the lack of validated surrogate measures so early in the disease process. The Deep and Frequent Phenotyping (DFP) study aims to resolve this issue by identifying a set of markers acting as indicators of disease progression in the prodromal phase of disease that could be used as indicative outcome measures in proof-of-concept trials. METHODS AND ANALYSIS The DFP study is a repeated measures observational study where participants will be recruited through existing parent cohorts, research interested lists/databases, advertisements and memory clinics. Repeated measures of both established (cognition, positron emission tomography (PET) imaging or cerebrospinal fluid (CSF) markers of pathology, structural MRI markers of neurodegeneration) and experimental modalities (functional MRI, magnetoencephalography and/or electroencephalography, gait measurement, ophthalmological and continuous smartphone-based cognitive and other assessments together with experimental CSF, blood, tear and saliva biomarkers) will be performed. We will be recruiting male and female participants aged >60 years with prodromal AD, defined as absence of dementia but with evidence of cognitive impairment together with AD pathology as assessed using PET imaging or CSF biomarkers. Control participants without evidence of AD pathology will be included at a 1:4 ratio. ETHICS AND DISSEMINATION The study gained favourable ethical opinion from the South Central-Oxford B NHS Research Ethics Committee (REC reference 17/SC/0315; approved on 18 August 2017; amendment 13 February 2018). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.
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Affiliation(s)
- Ivan Koychev
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Tharani Chessell
- IMED Neuroscience, AstraZeneca UK Ltd, Cambridge, Cambridgeshire, UK
| | - Clare Mackay
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Roger Gunn
- Invicro, London, UK
- Department of Medicine, Imperial College London, London, UK
| | - Barbara Sahakian
- Department of Psychiatry, University of Cambridge, Cambridge, Cambridgeshire, UK
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, Cambridgeshire, UK
| | - Alan J Thomas
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Lynn Rochester
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Dennis Chan
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- MRC Cognition and Brain Sciences Unit, Cambridge, Cambridgeshire, UK
| | - Brian Tom
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Paresh Malhotra
- Department of Neurology, Imperial College London Faculty of Medicine, London, UK
| | | | - Iain Chessell
- IMED Neuroscience, AstraZeneca UK Ltd, Cambridge, Cambridgeshire, UK
| | - Craig W Ritchie
- Department of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Vanessa Raymont
- Department of Psychiatry, University of Oxford, Oxford, UK
- Department of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Iracema Leroi
- Manchester Academic Health Sciences Centre, Institute of Brain, Behaviour, and Mental Health, Manchester, UK
| | | | | | - David L Thomas
- Leonard Wolfson Experimental Neurology Centre, University College London Institute of Neurology, London, London, UK
| | - John Gallacher
- Department of Psychiatry, University of Oxford, Oxford, UK
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3
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Cox TO, Gunther EC, Brody AH, Chiasseu MT, Stoner A, Smith LM, Haas LT, Hammersley J, Rees G, Dosanjh B, Groves M, Gardener M, Dobson C, Vaughan T, Chessell I, Billinton A, Strittmatter SM. Anti-PrP C antibody rescues cognition and synapses in transgenic alzheimer mice. Ann Clin Transl Neurol 2019; 6:554-574. [PMID: 30911579 PMCID: PMC6414488 DOI: 10.1002/acn3.730] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/21/2018] [Accepted: 01/08/2019] [Indexed: 12/28/2022] Open
Abstract
Objective Amyloid-beta oligomers (Aßo) trigger the development of Alzheimer's disease (AD) pathophysiology. Cellular prion protein (PrPC) initiates synaptic damage as a high affinity receptor for Aßo. Here, we evaluated the preclinical therapeutic efficacy of a fully human monoclonal antibody against PrPC. This AZ59 antibody selectively targets the Aβo binding site in the amino-terminal unstructured domain of PrPC to avoid any potential risk of direct toxicity. Methods Potency of AZ59 was evaluated by binding to PrPC, blockade of Aβo interaction and interruption of Aβo signaling. AZ59 was administered to mice by weekly intraperitoneal dosing and brain antibody measured. APP/PS1 transgenic mice were treated with AZ59 and assessed by memory tests, by brain biochemistry and by histochemistry for Aß, gliosis and synaptic density. Results AZ59 binds PrPC with 100 pmol/L affinity and blocks human brain Aßo binding to PrPC, as well as prevents synaptotoxic signaling. Weekly i.p. dosing of 20 mg/kg AZ59 in a murine form achieves trough brain antibody levels greater than 10 nmol/L. Aged symptomatic APP/PS1 transgenic mice treated with AZ59 for 5-7 weeks show a full rescue of behavioral and synaptic loss phenotypes. This recovery occurs without clearance of plaque pathology or elimination of gliosis. AZ59 treatment also normalizes synaptic signaling abnormalities in transgenic brain. These benefits are dose-dependent and persist for at least 1 month after the last dose. Interpretation Preclinical data demonstrate that systemic AZ59 therapy rescues central synapses and memory function from transgenic Alzheimer's disease pathology, supporting a disease-modifying therapeutic potential.
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Affiliation(s)
- Timothy O. Cox
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Erik C. Gunther
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - A. Harrison Brody
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Marius T. Chiasseu
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Austin Stoner
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Levi M. Smith
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Laura T. Haas
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
| | - Jayne Hammersley
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Gareth Rees
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Bhupinder Dosanjh
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Maria Groves
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Matthew Gardener
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Claire Dobson
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Tristan Vaughan
- Antibody Discovery and Protein EngineeringMedImmuneGranta ParkCambridgeCB21 6GHUK
| | - Iain Chessell
- NeuroscienceIMED Biotech UnitAstraZenecaGranta ParkCambridgeCB21 6GHUK
| | - Andrew Billinton
- NeuroscienceIMED Biotech UnitAstraZenecaGranta ParkCambridgeCB21 6GHUK
| | - Stephen M. Strittmatter
- Cellular Neuroscience Neurodegeneration & RepairDepartments of Neurology and of NeuroscienceYale University School of MedicineNew Haven06536Connecticut
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4
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Thornton P, Sevalle J, Deery MJ, Fraser G, Zhou Y, Ståhl S, Franssen EH, Dodd RB, Qamar S, Gomez Perez‐Nievas B, Nicol LSC, Eketjäll S, Revell J, Jones C, Billinton A, St George‐Hyslop PH, Chessell I, Crowther DC. TREM2 shedding by cleavage at the H157-S158 bond is accelerated for the Alzheimer's disease-associated H157Y variant. EMBO Mol Med 2017; 9:1366-1378. [PMID: 28855301 PMCID: PMC5623839 DOI: 10.15252/emmm.201707673] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have characterised the proteolytic cleavage events responsible for the shedding of triggering receptor expressed on myeloid cells 2 (TREM2) from primary cultures of human macrophages, murine microglia and TREM2-expressing human embryonic kidney (HEK293) cells. In all cell types, a soluble 17 kDa N-terminal cleavage fragment was shed into the conditioned media in a constitutive process that is inhibited by G1254023X and metalloprotease inhibitors and siRNA targeting ADAM10. Inhibitors of serine proteases and matrix metalloproteinases 2/9, and ADAM17 siRNA did not block TREM2 shedding. Peptidomimetic protease inhibitors highlighted a possible cleavage site, and mass spectrometry confirmed that shedding occurred predominantly at the H157-S158 peptide bond for both wild-type and H157Y human TREM2 and for the wild-type murine orthologue. Crucially, we also show that the Alzheimer's disease-associated H157Y TREM2 variant was shed more rapidly than wild type from HEK293 cells, possibly by a novel, batimastat- and ADAM10-siRNA-independent, sheddase activity. These insights offer new therapeutic targets for modulating the innate immune response in Alzheimer's and other neurological diseases.
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Affiliation(s)
- Peter Thornton
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
| | - Jean Sevalle
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada
| | - Michael J Deery
- Cambridge Centre for ProteomicsUniversity of CambridgeCambridgeUK
| | - Graham Fraser
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
| | - Ye Zhou
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada
| | - Sara Ståhl
- AstraZeneca Translational Sciences CentreKarolinska InstitutetStockholmSweden
| | - Elske H Franssen
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
| | - Roger B Dodd
- Department of Clinical NeurosciencesCambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK,MedImmune LimitedGranta ParkCambridgeUK
| | - Seema Qamar
- Department of Clinical NeurosciencesCambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | | | | | - Susanna Eketjäll
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early DevelopmentAstraZeneca, ICMCHuddingeSweden
| | | | | | - Andrew Billinton
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
| | - Peter H St George‐Hyslop
- Tanz Centre for Research in Neurodegenerative DiseasesUniversity of TorontoTorontoONCanada,Department of Clinical NeurosciencesCambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Iain Chessell
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
| | - Damian C Crowther
- Neuroscience, Innovative Medicines and Early DevelopmentAstraZenecaGranta ParkCambridgeUK
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Ondrejcak T, O'Malley TT, Perkinton M, Dudley A, Chessell I, Groves M, Walsh DM, Billinton A, Rowan MJ. [P3–036]: MEDI1814, A HIGH‐AFFINITY ANTIBODY DIRECTED TO THE C‐TERMINUS OF AβX‐42, ABROGATES SYNAPTIC PLASTICITY DISRUPTION CAUSED BY SYNTHETIC OR AD BRAIN‐DERIVED Aβ SOLUBLE ASSEMBLIES
IN VIVO. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.1849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Tomas Ondrejcak
- Department of Pharmacology and TherapeuticsTrinity CollegeDublinIreland
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6
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Ostenfeld T, Pomfret M, Billinton A, Chessell I, Chessell T, Lindqvist E, Valencia ZS, Groves M, Narwal R, Tatipalli M, Lee N, Turner R, Tan K, Dudley A. [O2–09–02]: EVALUATION OF SAFETY, TOLERABILITY, PHARMACOKINETICS AND PHARMACODYNAMICS OF MEDI1814, A BETA‐AMYLOID 42 (Aβ42)‐SPECIFIC ANTIBODY, IN PATIENTS WITH MILD‐MODERATE ALZHEIMER'S DISEASE. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.07.193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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)
- Thor Ostenfeld
- AstraZenecaCambridgeUnited Kingdom
- AstraZenecaGothenburgSweden
- MedimmuneGaithersburgMDUSA
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7
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Thornton P, Hatcher JP, Robinson I, Sargent B, Franzén B, Martino G, Kitching L, Glover CP, Anderson D, Forsmo-Bruce H, Low CP, Cusdin F, Dosanjh B, Williams W, Steffen AC, Thompson S, Eklund M, Lloyd C, Chessell I, Hughes J. Artemin-GFRα3 interactions partially contribute to acute inflammatory hypersensitivity. Neurosci Lett 2013; 545:23-8. [PMID: 23603259 DOI: 10.1016/j.neulet.2013.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 03/30/2013] [Accepted: 04/02/2013] [Indexed: 10/26/2022]
Abstract
The expression of artemin (ARTN), a glial cell line-derived neurotrophic factor (GDNF) family ligand, increases in pre-clinical models of nociception and recent evidence suggests this growth factor may play a causative role in inflammatory pain mechanisms. The aim of this study was to demonstrate functional inhibition of ARTN with monoclonal antibodies and to determine whether ARTN neutralisation could reverse inflammatory pain in mice. We show that monoclonal antibodies with high affinity to ARTN, completely inhibit ARTN-induced Ret and ERK activation in a human neuroblastoma cell line, and block capsaicin-induced CGRP secretion from primary rat DRG cultures. In addition, administration of anti-ARTN antibodies to mice provides a transient, partial reversal (41%) of FCA-induced mechanical hypersensitivity. Anti-ARTN antibodies had no effect on hypersensitivity in response to partial nerve ligation in mice. These data suggest that ARTN-GFRα3 interactions partially mediate early stage nociceptive signalling following an inflammatory insult.
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Hughes JP, Chessell I, Malamut R, Perkins M, Bačkonja M, Baron R, Farrar JT, Field MJ, Gereau RW, Gilron I, McMahon SB, Porreca F, Rappaport BA, Rice F, Richman LK, Segerdahl M, Seminowicz DA, Watkins LR, Waxman SG, Wiech K, Woolf C. Understanding chronic inflammatory and neuropathic pain. Ann N Y Acad Sci 2012; 1255:30-44. [PMID: 22564068 DOI: 10.1111/j.1749-6632.2012.06561.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This meeting report highlights the main topics presented at the conference "Chronic Inflammatory and Neuropathic Pain," convened jointly by the New York Academy of Sciences, MedImmune, and Grünenthal GmbH, on June 2-3, 2011, with the goal of providing a conducive environment for lively, informed, and synergistic conversation among participants from academia, industry, clinical practice, and government to explore new frontiers in our understanding and treatment of chronic and neuropathic pain. The program included leading and emerging investigators studying the pathophysiological mechanisms underlying neuropathic and chronic pain, and experts in the clinical development of pain therapies. Discussion included novel issues, current challenges, and future directions of basic research in pain and preclinical and clinical development of new therapies for chronic pain.
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Chessell I, Hatcher J, Billinton A. Mechanistic differentiation of cancer pain: A pivotal role of P2X7 is absent. Pain 2011; 152:1703-1704. [DOI: 10.1016/j.pain.2011.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 04/05/2011] [Accepted: 04/06/2011] [Indexed: 10/18/2022]
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Schweinhardt P, Kalk N, Wartolowska K, Chessell I, Wordsworth P, Tracey I. Corrigendum to “Investigation into the neural correlates of emotional augmentation of clinical pain” [Neuroimage 40/2 (2008) 759–766]. Neuroimage 2011. [DOI: 10.1016/j.neuroimage.2011.02.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Chessell I, Hatcher J, Hughes J. A new utensil in our toolbox: Exploring the role of IL-6 in pain using a naturally occurring antagonist. Pain 2010; 151:235-236. [DOI: 10.1016/j.pain.2010.06.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 06/29/2010] [Indexed: 10/19/2022]
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12
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Gwilym SE, Keltner JR, Warnaby CE, Carr AJ, Chizh B, Chessell I, Tracey I. Psychophysical and functional imaging evidence supporting the presence of central sensitization in a cohort of osteoarthritis patients. ACTA ACUST UNITED AC 2009; 61:1226-34. [PMID: 19714588 DOI: 10.1002/art.24837] [Citation(s) in RCA: 308] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE The groin pain experienced by patients with hip osteoarthritis (OA) is often accompanied by areas of referred pain and changes in skin sensitivity. We aimed to identify the supraspinal influences that underlie these clinical manifestations that we consider indicative of possible central sensitization. METHODS Twenty patients with hip OA awaiting joint replacement and displaying signs of referred pain were recruited into the study, together with age-matched controls. All subjects completed pain psychology questionnaires and underwent quantitative sensory testing (QST) in their area of referred pain. Twelve of 20 patients and their age- and sex-matched controls underwent functional magnetic resonance imaging (MRI) while the areas of referred pain were stimulated using cold stimuli (12 degrees C) and punctate stimuli (256 mN). The remaining 8 of 20 patients underwent punctate stimulation only. RESULTS Patients were found to have significantly lower threshold perception to punctate stimuli and were hyperalgesic to the noxious punctate stimulus in their areas of referred pain. Functional brain imaging illustrated significantly greater activation in the brainstem of OA patients in response to punctate stimulation of their referred pain areas compared with healthy controls, and the magnitude of this activation positively correlated with the extent of neuropathic-like elements to the patient's pain, as indicated by the PainDETECT score. DISCUSSION Using psychophysical (QST) and brain imaging methods (functional MRI), we have identified increased activity with the periaqueductal grey matter associated with stimulation of the skin in referred pain areas of patients with hip OA. This offers a central target for analgesia aimed at improving the treatment of this largely peripheral disease.
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Medhurst S, Hughes J, Clayton N, Patel S, Ali Z, Johnson C, Chessell I, Billinton A. 434 ANTINOCICEPTIVE EFFECTS OF A SELECTIVE ERBETA AGONIST THROUGH MODULATION OF THE ENDOGENOUS OPIOID SYSTEM. Eur J Pain 2009. [DOI: 10.1016/s1090-3801(09)60437-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- S. Medhurst
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
| | - J. Hughes
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
| | - N. Clayton
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
| | - S. Patel
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
| | - Z. Ali
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
| | - C. Johnson
- Astex‐Therapeutics, Cambridge, United Kingdom
| | | | - A. Billinton
- GlaxoSmithKline Research and Development Ltd, Harlow, United Kingdom
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Schweinhardt P, Kalk N, Wartolowska K, Chessell I, Wordsworth P, Tracey I. Investigation into the neural correlates of emotional augmentation of clinical pain. Neuroimage 2007; 40:759-766. [PMID: 18221890 DOI: 10.1016/j.neuroimage.2007.12.016] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 11/29/2007] [Accepted: 12/05/2007] [Indexed: 11/24/2022] Open
Abstract
Although depressive mood is an important psychological determinate of chronic pain, the neural circuitry that mediates its influence on the pain experience is largely unknown. We used functional magnetic resonance imaging (FMRI) to investigate the neurophysiological interactions between depressive symptoms and disease-relevant pain in rheumatoid arthritis (RA) patients. RA is associated with chronic joint pain and swelling, but peripheral joint pathology often does not fully explain the amount of pain a patient experiences. We investigated the neural circuitry that relates joint pain and depressive symptoms and contrasted this with experimental heat pain. We hypothesized that (1) depressive symptoms influence the cerebral processing of provoked joint pain in RA, and (2) the interaction of depressive symptoms with pain processing contributes to the pain RA patients experience on a daily basis. Twenty patients underwent whole brain FMRI during which disease-relevant joint pain was provoked. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). The tender-to-swollen joint ratio (T/S) was assessed as one component of the patients' clinical pain. BDI scores correlated significantly with T/S and medial prefrontal cortex (MPFC) activation during provoked joint pain. The association between BDI scores and T/S was partly mediated by the MPFC activation. Furthermore, the MPFC activation co-varied significantly with the FMRI signal in limbic areas and in areas that process self-relevant information. These results suggest that the MPFC may play an important role in mediating the relationship between depressive symptoms and clinical pain severity in RA, possibly by engaging brain areas important for affective and self-relevant processing.
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Affiliation(s)
- Petra Schweinhardt
- Centre for Functional Magnetic Resonance Imaging, Department of Clinical Neurology, John Radcliffe Hospital, Oxford, OX3 9DU, UK; Department of Physiology, Anatomy and Genetics, Oxford University, South Parks Road, Oxford, OX1 3QX, UK.
| | - Nicola Kalk
- Centre for Functional Magnetic Resonance Imaging, Department of Clinical Neurology, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Karolina Wartolowska
- Centre for Functional Magnetic Resonance Imaging, Department of Clinical Neurology, John Radcliffe Hospital, Oxford, OX3 9DU, UK; Department of Physiology, Anatomy and Genetics, Oxford University, South Parks Road, Oxford, OX1 3QX, UK
| | - Iain Chessell
- N & GI CEDD, Glaxo Smith Kline, Harlow, CM19 5AD, UK
| | - Paul Wordsworth
- Department of Rheumatology, Nuffield Orthopedic Centre, Oxford, OX3 7LD, UK
| | - Irene Tracey
- Centre for Functional Magnetic Resonance Imaging, Department of Clinical Neurology, John Radcliffe Hospital, Oxford, OX3 9DU, UK; Department of Physiology, Anatomy and Genetics, Oxford University, South Parks Road, Oxford, OX1 3QX, UK
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Medhurst AD, Briggs MA, Bruton G, Calver AR, Chessell I, Crook B, Davis JB, Davis RP, Foley AG, Heslop T, Hirst WD, Medhurst SJ, Ociepka S, Ray A, Regan CM, Sargent B, Schogger J, Stean TO, Trail BK, Upton N, White T, Orlek B, Wilson DM. Structurally novel histamine H3 receptor antagonists GSK207040 and GSK334429 improve scopolamine-induced memory impairment and capsaicin-induced secondary allodynia in rats. Biochem Pharmacol 2007; 73:1182-94. [PMID: 17276409 DOI: 10.1016/j.bcp.2007.01.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 12/13/2006] [Accepted: 01/03/2007] [Indexed: 11/25/2022]
Abstract
GSK207040 (5-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-N-methyl-2-pyrazinecarboxamide) and GSK334429 (1-(1-methylethyl)-4-({1-[6-(trifluoromethyl)-3-pyridinyl]-4-piperidinyl}carbonyl)hexahydro-1H-1,4-diazepine) are novel and selective non-imidazole histamine H(3) receptor antagonists from distinct chemical series with high affinity for human (pK(i)=9.67+/-0.06 and 9.49+/-0.09, respectively) and rat (pK(i)=9.08+/-0.16 and 9.12+/-0.14, respectively) H(3) receptors expressed in cerebral cortex. At the human recombinant H(3) receptor, GSK207040 and GSK334429 were potent functional antagonists (pA(2)=9.26+/-0.04 and 8.84+/-0.04, respectively versus H(3) agonist-induced changes in cAMP) and exhibited inverse agonist properties (pIC(50)=9.20+/-0.36 and 8.59+/-0.04 versus basal GTPgammaS binding). Following oral administration, GSK207040 and GSK334429 potently inhibited cortical ex vivo [(3)H]-R-alpha-methylhistamine binding (ED(50)=0.03 and 0.35 mg/kg, respectively). Functional antagonism of central H(3) receptors was demonstrated by blockade of R-alpha-methylhistamine-induced dipsogenia in rats (ID(50)=0.02 and 0.11 mg/kg p.o. for GSK207040 and GSK334429, respectively). In more pathophysiologically relevant pharmacodynamic models, GSK207040 (0.1, 0.3, 1 and 3mg/kg p.o.) and GSK334429 (0.3, 1 and 3mg/kg p.o.) significantly reversed amnesia induced by the cholinergic antagonist scopolamine in a passive avoidance paradigm. In addition, GSK207040 (0.1, 0.3 and 1mg/kg p.o.) and GSK334429 (3 and 10mg/kg p.o.) significantly reversed capsaicin-induced reductions in paw withdrawal threshold, suggesting for the first time that blockade of H(3) receptors may be able to reduce tactile allodynia. Novel H(3) receptor antagonists such as GSK207040 and GSK334429 may therefore have therapeutic potential not only in dementia but also in neuropathic pain.
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Affiliation(s)
- Andrew D Medhurst
- Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline, Third Avenue, Harlow, Essex CM19 5AW, UK.
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Skaper SD, Facci L, Culbert AA, Evans NA, Chessell I, Davis JB, Richardson JC. P2X(7) receptors on microglial cells mediate injury to cortical neurons in vitro. Glia 2006; 54:234-42. [PMID: 16817206 DOI: 10.1002/glia.20379] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [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: 11/06/2022]
Abstract
The P2X(7) receptor has been implicated in the release of cytokines and in the induction of cell death, and is up-regulated in a transgenic mouse model of Alzheimer's disease. Using cocultures of rat cortical neurons and microglia, we show that ATP and the more potent P2X(7) agonist benzoylbenzoyl-ATP (BzATP) cause neuronal cell injury. The deleterious effects of BzATP-treated microglia were prevented by nonselective P2X antagonists (PPADS and oxidized ATP) and by the more selective P2X(7) antagonist Brilliant Blue G. Similar concentrations of BzATP caused release of superoxide and nitric oxide from isolated microglia, and neuronal cell injury was attenuated by a superoxide dismutase mimetic and by a peroxynitrite decomposition catalyst, suggesting a role for reactive oxide species. Cocultures composed of wild-type cortical neurons, and microglia from P2X(7) receptor-deficient mice failed to exhibit neuronal cell injury in the presence of BzATP, but retained sensitivity to injury when microglia were derived from genotypically matched normal (P2X(7) (+/+) mice), thereby establishing P2X(7) involvement in the injury process. P2X(7) receptor activation on microglia thus appears necessary for microglial-mediated injury of neurons, and proposes that targeting P2X(7) receptors may constitute a novel approach for the treatment of acute and chronic neurodegenerative disorders where a microglial component is evident.
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Affiliation(s)
- Stephen D Skaper
- Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development Limited, New Frontiers Science Park, Third Avenue, Harlow CM19 5AW, Essex, United Kingdom.
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Schweinhardt P, Kalk N, Wordsworth P, Chessell I, Tracey I. 279 DIFFERENTIAL INFLUENCE OF DEPRESSIVE SYMPTOMS ON CEREBRAL PROCESSING OF CLINICAL AND EXPERIMENTAL PAIN IN PATIENTS WITH RHEUMATOID ARTHRITIS. Eur J Pain 2006. [DOI: 10.1016/s1090-3801(06)60282-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schweinhardt P, Glynn C, Brooks J, McQuay H, Jack T, Chessell I, Bountra C, Tracey I. An fMRI study of cerebral processing of brush-evoked allodynia in neuropathic pain patients. Neuroimage 2006; 32:256-65. [PMID: 16679031 DOI: 10.1016/j.neuroimage.2006.03.024] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [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] [Received: 08/04/2005] [Revised: 02/06/2006] [Accepted: 03/10/2006] [Indexed: 11/18/2022] Open
Abstract
Previous human imaging studies have revealed a network of brain regions involved in the processing of allodynic pain; this includes prefrontal areas, insula, cingulate cortex, primary and secondary somatosensory cortices and parietal association areas. In this study, the neural correlates of the perceived intensity of allodynic pain in neuropathic pain patients were investigated. In eight patients, dynamic mechanical allodynia was provoked and brain responses recorded using functional magnetic resonance imaging (fMRI). Voxels in which the magnitude of fMRI signal correlated linearly with the ratings of allodynic pain across the group were determined in a whole brain analysis using a general linear model. To ensure that activation reflected only allodynic pain ratings, a nuisance variable containing ratings of ongoing pain was included in the analysis. We found that the magnitude of activation in the caudal anterior insula (cAI) correlates with the perceived intensity of allodynic pain across subjects, independent of the level of ongoing pain. However, the peak of activation in the allodynic condition was located in the rostral portion (rAI). This matches the representation of other clinical pain syndromes, confirmed by a literature review. In contrast, experimental pain in healthy volunteers resides predominantly in the cAI, as shown by the same literature review. Taken together, our data and the literature review suggest a functional segregation of anterior insular cortex.
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Affiliation(s)
- Petra Schweinhardt
- Department of Human Anatomy and Genetics, Oxford University, South Parks Road, Oxford OX1 1QX, UK.
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De Alba J, Clayton NM, Collins SD, Colthup P, Chessell I, Knowles RG. GW274150, a novel and highly selective inhibitor of the inducible isoform of nitric oxide synthase (iNOS), shows analgesic effects in rat models of inflammatory and neuropathic pain. Pain 2005; 120:170-181. [PMID: 16360270 DOI: 10.1016/j.pain.2005.10.028] [Citation(s) in RCA: 96] [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] [Received: 05/23/2005] [Revised: 10/10/2005] [Accepted: 10/31/2005] [Indexed: 10/25/2022]
Abstract
Nitric oxide (NO), synthesised by different isoforms of nitric oxide synthase (NOS), has been linked with the development and maintenance of nociception. We studied the role of the inducible isoform, iNOS, in two different rat pain models with an inflammatory component. iNOS was immunohistochemically detected locally in the paw 6h after Freund's Complete Adjuvant (FCA) injection, showing a plateau at 24-72 h and falling slowly in the following weeks. This correlated with the late phase of the hypersensitivity to pain revealed in the behavioural tests. A highly selective iNOS inhibitor GW274150 (1-30 mg/kg orally, 24h after FCA) suppressed the accumulation of nitrite in the inflamed paw indicating substantial iNOS inhibition. At the same time it partially reversed FCA-induced hypersensitivity to pain and edema in a dose-dependent manner. After Chronic Constriction Injury (CCI) surgery to the sciatic nerve, iNOS presence was only detected locally in the region of the nerve (inflammatory cells). GW274150 (3-30 mg/kg orally, 21 days after surgery) also reversed significantly the CCI-associated hypersensitivity to pain. No iNOS was detectable in dorsal root ganglia, spinal cord or brain in either model. This study demonstrates a role for peripherally-expressed iNOS in pain conditions with an inflammatory component and the potential value of iNOS inhibitors in such conditions.
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Affiliation(s)
- Jorge De Alba
- Department of Respiratory Pharmacology, RI CEDD GlaxoSmithKline Research and Development, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK Department of Pain, Neurology+GI CEDD, GlaxoSmithKline Research and Development, New Frontiers Science Park, Third Avenue. Harlow, Essex CM19 5AW, UK Department of Drug Metabolism and Pharmacokinetics, DMPK, GlaxoSmithKline Research and Development Park Road, Ware, Hertfordshire SG12 ODP, UK
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Beswick P, Bingham S, Bountra C, Brown T, Browning K, Campbell I, Chessell I, Clayton N, Collins S, Corfield J, Guntrip S, Haslam C, Lambeth P, Lucas F, Mathews N, Murkit G, Naylor A, Pegg N, Pickup E, Player H, Price H, Stevens A, Stratton S, Wiseman J. Identification of 2,3-diaryl-pyrazolo[1,5-b]pyridazines as potent and selective cyclooxygenase-2 inhibitors. Bioorg Med Chem Lett 2004; 14:5445-8. [PMID: 15454242 DOI: 10.1016/j.bmcl.2004.07.089] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Revised: 07/26/2004] [Accepted: 07/26/2004] [Indexed: 11/23/2022]
Abstract
GW406381 (8), currently undergoing clinical evaluation for the treatment of inflammatory pain is a member of a novel series of 2,3-diaryl-pyrazolo[1,5-b]pyridazine based cyclooxygenase-2 (COX-2) inhibitors, which have been shown to be highly potent and selective. Several examples of the series, in addition to possessing favourable pharmacokinetic profiles and analgesic activity in vivo, have also demonstrated relatively high brain penetration in the rat compared with the clinically available compounds, which may ultimately prove beneficial in the treatment of pain.
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Affiliation(s)
- Paul Beswick
- Neurology and Gastrointestinal Diseases, Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK
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Gartland A, Buckley KA, Hipskind RA, Perry MJ, Tobias JH, Buell G, Chessell I, Bowler WB, Gallagher JA. Multinucleated osteoclast formation in vivo and in vitro by P2X7 receptor-deficient mice. Crit Rev Eukaryot Gene Expr 2004; 13:243-53. [PMID: 14696971 DOI: 10.1615/critreveukaryotgeneexpr.v13.i24.150] [Citation(s) in RCA: 52] [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: 11/13/2022]
Abstract
The P2X7 receptor is a member of the family of P2X purinergic receptors, which upon sustained activation forms large pores in the plasma membrane. In cells of hematopoietic origin, P2X7 receptor activation has been shown to lead to multiple downstream events, including cytokine release, cell permeabilization, and apoptosis. This receptor has also been implicated in the generation of multinucleated giant cells, polykaryons, and osteoclasts. We have recently demonstrated that a blockade of this receptor inhibits osteoclast formation in vitro; therefore, we examined mice deficient in the P2X7 receptor in the context of bone. These mice were healthy and displayed no overt skeletal problems. Furthermore, we were able to demonstrate their ability to form multinucleated cells, in particular osteoclasts, both in vivo and in vitro. We also demonstrate the ability of P2X7R-/- multinucleated osteoclasts, upon stimulation with maitotoxin (MTX), to form pores in the plasma membrane in vitro. These findings are consistent with the existence of an endogenous pore structure present in osteoclast precursor cells that can be activated either by the P2X7 receptor, or in its absence, by alternative signals to mediate fusion and pore formation. These data provide further insight into the mode of action of the P2X7 receptor.
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Affiliation(s)
- A Gartland
- Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue N., Worcester, MA 01655, USA.
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Bland-Ward P, Chessell I, Humphrey P. P2X Purinergic Receptors for ATP in Nociception. Pain 2003. [DOI: 10.1201/9780203911259.ch54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gartland A, Buckley KA, Hipskind RA, Perry MJ, Tobias JH, Buell G, Chessell I, Bowler WB, Gallagher JA. Multinucleated Osteoclast Formation In Vivo and In Vitro by P2X7 Receptor-Deficient Mice. Crit Rev Eukaryot Gene Expr 2003. [DOI: 10.1615/critreveukaryotgeneexpr.v13.i24.160] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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McQueen DS, Bond SM, Moores C, Chessell I, Humphrey PP, Dowd E. Activation of P2X receptors for adenosine triphosphate evokes cardiorespiratory reflexes in anaesthetized rats. J Physiol 1998; 507 ( Pt 3):843-55. [PMID: 9508844 PMCID: PMC2230827 DOI: 10.1111/j.1469-7793.1998.843bs.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [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: 02/06/2023] Open
Abstract
1. We tested the hypothesis that activation of P2X receptors associated with vagal afferent nerves can evoke a Bezold-Jarisch (B-J) depressor reflex in anaesthetized rats. 2. Injection of alphabeta-methylene ATP (alphabeta-MeATP; 0.6-600 nmol i.v.) evoked a dose-dependent B-J reflex comprising bradycardia, hypotension and apnoea in rats anaesthetized with pentobarbitone. Apnoea was commonly preceded by hyperventilation. Bilateral vagotomy significantly reduced the bradycardia and most of the apnoeic response without affecting hyperventilation, and unmasked a vasopressor response. Hypotension and apnoea were subject to desensitization, and ATP was about 100 times less potent than alphabeta-MeATP in evoking the B-J reflex. 3. ED50 values for responses to alphabeta-MeATP were: bradycardia 14.6 +/- 3.8 nmol; apnoea 47.1 +/- 8.5 nmol; hyperventilation 23.3 +/- 6.0 nmol, n = 14. The ED50 for apnoea was significantly greater than that for bradycardia or hyperventilation (P < 0.05). Atropine (2.8 micromol (kg body wt)-1 i.v.) antagonized the reflex bradycardia and hypotension. 4. The P2 antagonists suramin (14 micromol (kg body wt)-1 i.v.) and PPADS (17 micromol (kg body wt)-1 i.v.) antagonized the bradycardic and apnoeic components of the reflex response to alphabeta-MeATP, without reducing the vasopressor or hyperventilatory responses to the agonist. 5. Recordings from vagal afferents showed that pulmonary inflation receptors were activated by alphabeta-MeATP in 62 % of units recorded (ED50 22 +/- 5 nmol) and this was blocked by PPADS (17 micromol (kg body wt)-1 i.v.); unidentified vagal afferents were also activated. 6. alphabeta-MeATP activated carotid chemoreceptor afferents (ED50 23 +/- 9 nmol), an action that was unaffected by PPADS or suramin. 7. The results support the hypothesis that P2X receptor subtypes for ATP are associated with specific sensory nerves that form part of the homeostatic mechanism for cardiovascular and respiratory regulation and these receptors therefore have physiological, pathological and therapeutic significance.
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Affiliation(s)
- D S McQueen
- Department of Pharmacology, University of Edinburgh Medical School, Edinburgh EH8 9JZ, UK.
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