1
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Davis LC, Morgan AJ, Galione A. Optical profiling of autonomous Ca 2+ nanodomains generated by lysosomal TPC2 and TRPML1. Cell Calcium 2023; 116:102801. [PMID: 37742482 DOI: 10.1016/j.ceca.2023.102801] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/30/2023] [Accepted: 09/17/2023] [Indexed: 09/26/2023]
Abstract
Multiple families of Ca2+-permeable channels co-exist on lysosomal Ca2+ stores but how each family couples to its own unique downstream physiology is unclear. We have therefore investigated the Ca2+-signalling architecture underpinning different channels on the same vesicle that drive separate pathways, using phagocytosis as a physiological stimulus. Lysosomal Ca2+-channels are a major Ca2+ source driving particle uptake in macrophages, but different channels drive different aspects of Fc-receptor-mediated phagocytosis: TPC2 couples to dynamin activation, whilst TRPML1 couples to lysosomal exocytosis. We hypothesised that they are driven by discrete local plumes of Ca2+ around open channels (Ca2+ nanodomains). To test this, we optimized Ca2+-nanodomain recordings by screening panels of genetically encoded Ca2+ indicators (GECIs) fused to TPC2 to monitor the [Ca2+] next to the channel. Signal calibration accounting for the distance of the GECI from the channel mouth reveals that, during phagocytosis, TPC2 generates local Ca2+ nanodomains around itself of up to 42 µM, nearly a hundred-fold greater than the global cytosolic [Ca2+] rise. We further show that TPC2 and TRPML1, though on the same lysosomes, generate autonomous Ca2+ nanodomains of high [Ca2+] that are largely insulated from one another, a platform allowing their discrete Ca2+-decoding to promote unique respective physiologies.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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2
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Abstract
The discovery of NAADP-evoked Ca2+ release in sea urchin eggs and then as a ubiquitous Ca2+ mobilizing messenger has introduced several novel paradigms to our understanding of Ca2+ signalling, not least in providing a link between cell stimulation and Ca2+ release from lysosomes and other acidic Ca2+ storage organelles. In addition, the hallmark concentration-response relationship of NAADP-mediated Ca2+ release, shaped by striking activation/desensitization mechanisms, influences its actions as an intracellular messenger. There has been recent progress in our understanding of the molecular mechanisms underlying NAADP-evoked Ca2+ release, such as the identification of the endo-lysosomal two-pore channel family of cation channels (TPCs) as their principal target and the identity of NAADP-binding proteins that complex with them. The NAADP/TPC signalling axis has gained recent prominence in pathophysiology for their roles in such disease processes as neurodegeneration, tumorigenesis and cellular viral entry.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lora L Martucci
- Department of Pharmacology, University of Oxford, Oxford, UK
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3
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Abstract
Acidic organelles act as intracellular Ca2+ stores; they actively sequester Ca2+ in their lumina and release it to the cytosol upon activation of endo-lysosomal Ca2+ channels. Recent data suggest important roles of endo-lysosomal Ca2+ channels, the Two-Pore Channels (TPCs) and the TRPML channels (mucolipins), in different aspects of immune-cell function, particularly impacting membrane trafficking, vesicle fusion/fission and secretion. Remarkably, different channels on the same acidic vesicles can couple to different downstream physiology. Endo-lysosomal Ca2+ stores can act under different modalities, be they acting alone (via local Ca2+ nanodomains around TPCs/TRPMLs) or in conjunction with the ER Ca2+ store (to either promote or suppress global ER Ca2+ release). These different modalities impinge upon functions as broad as phagocytosis, cell-killing, anaphylaxis, immune memory, thrombostasis, and chemotaxis.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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4
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Morgan AJ, Davis LC, Galione A. Choreographing endo-lysosomal Ca 2+ throughout the life of a phagosome. Biochim Biophys Acta Mol Cell Res 2021; 1868:119040. [PMID: 33872669 DOI: 10.1016/j.bbamcr.2021.119040] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022]
Abstract
The emergence of endo-lysosomes as ubiquitous Ca2+ stores with their unique cohort of channels has resulted in their being implicated in a growing number of processes in an ever-increasing number of cell types. The architectural and regulatory constraints of these acidic Ca2+ stores distinguishes them from other larger Ca2+ sources such as the ER and influx across the plasma membrane. In view of recent advances in the understanding of the modes of operation, we discuss phagocytosis as a template for how endo-lysosomal Ca2+ signals (generated via TPC and TRPML channels) can be integrated in multiple sophisticated ways into biological processes. Phagocytosis illustrates how different endo-lysosomal Ca2+ signals drive different phases of a process, and how these can be altered by disease or infection.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
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5
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Johnson CL, Hart LM, Rossetto A, Morgan AJ, Jorm AF. Lessons learnt from the field: a qualitative evaluation of adolescent experiences of a universal mental health education program. Health Educ Res 2021; 36:126-139. [PMID: 33367691 DOI: 10.1093/her/cyaa050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/26/2020] [Indexed: 06/12/2023]
Abstract
teen Mental Health First Aid (teenMHFA) is a school-based mental health program that trains adolescents to support peers who are experiencing mental health problems or crises. The program has been evaluated for adolescents aged 15-18 years as part of a randomized controlled trial, however qualitative feedback from students on their perceptions of the program is yet to be explored. The current study describes the perspectives of students who took part in the trial. Feedback on the perceived strengths and weaknesses of the program was provided by 979 Year 10 students (M = 15.82 years, female = 43.94%, English as a first language = 72.77%) at four government funded public schools in Melbourne, Australia via online surveys. A content and thematic analysis was performed on the data using a six-step process. Students generally found the program relevant and they connected with the visual material, personal stories and interactive activities. Suggestions for improvements included encouraging active student participation in classroom discussion and providing opportunities to practice skills. School-based mental health education can benefit from input from stakeholder perspectives, particularly when designing mental health content for delivery by external trainers.
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Affiliation(s)
- C L Johnson
- Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, Carlton, Melbourne, Victoria 3053, Australia
| | - L M Hart
- Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, Carlton, Melbourne, Victoria 3053, Australia
- School of Psychology and Public Health, College of Science, Health and Engineering, Level 4, George Singer Building, Melbourne Campus, Kingsbury Drive, Bundoora, Victoria 3086, Australia
| | - A Rossetto
- Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, Carlton, Melbourne, Victoria 3053, Australia
| | - A J Morgan
- Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, Carlton, Melbourne, Victoria 3053, Australia
| | - A F Jorm
- Centre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, Carlton, Melbourne, Victoria 3053, Australia
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Abstract
Pharmacological manipulation of lysosome membrane integrity or ionic movements is a key strategy for probing lysosomal involvement in cellular processes. However, we have found an unexpected inhibition of store-operated Ca2+ entry (SOCE) by these agents. Dipeptides [glycyl-L-phenylalanine 2-naphthylamide (GPN) and L-leucyl-L-leucine methyl ester] that are inducers of lysosomal membrane permeabilization (LMP) uncoupled endoplasmic reticulum Ca2+-store depletion from SOCE by interfering with Stim1 oligomerization and/or Stim1 activation of Orai. Similarly, the K+/H+ ionophore, nigericin, that rapidly elevates lysosomal pH, also inhibited SOCE in a Stim1-dependent manner. In contrast, other strategies for manipulating lysosomes (bafilomycin A1, lysosomal re-positioning) had no effect upon SOCE. Finally, the effects of GPN on SOCE and Stim1 was reversed by a dynamin inhibitor, dynasore. Our data show that lysosomal agents not only release Ca2+ from stores but also uncouple this release from the normal recruitment of Ca2+ influx. Summary: Lysosomal agents uncouple ER Ca2+-release from store-operated Ca2+ entry, predominantly by inhibiting Stim1 oligomerization and its activation of Orai.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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7
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Galione A, Davis LC, Morgan AJ. A cellular protection racket: How lysosomal Ca 2+ fluxes prevent kidney injury. Cell Calcium 2020; 93:102328. [PMID: 33352478 DOI: 10.1016/j.ceca.2020.102328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 10/22/2022]
Abstract
LC3-lipidation is activated by lysosomal damage by mechanisms that are unknown and divergent from canonical autophagy. In this study, Nakamura et al, show that lysosomal damage induced by lysosomotropic agents or oxalate in renal proximal tubule cells causes lipidated LC3 to insert into the lysosomal membrane to activate TRPML1 channels and release Ca2+ from lysosomes. This leads to TFEB dephosphorylation and translocation into the nucleus which results in clearance of damaged lysosomes and their contents which may reduce the deleterious effects of crystal nephropathy.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
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Davis LC, Morgan AJ, Galione A. NAADP-regulated two-pore channels drive phagocytosis through endo-lysosomal Ca 2+ nanodomains, calcineurin and dynamin. EMBO J 2020; 39:e104058. [PMID: 32510172 PMCID: PMC7360967 DOI: 10.15252/embj.2019104058] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Macrophages clear pathogens by phagocytosis and lysosomes that fuse with phagosomes are traditionally regarded as to a source of membranes and luminal degradative enzymes. Here, we reveal that endo-lysosomes act as platforms for a new phagocytic signalling pathway in which FcγR activation recruits the second messenger NAADP and thereby promotes the opening of Ca2+ -permeable two-pore channels (TPCs). Remarkably, phagocytosis is driven by these local endo-lysosomal Ca2+ nanodomains rather than global cytoplasmic or ER Ca2+ signals. Motile endolysosomes contact nascent phagosomes to promote phagocytosis, whereas endo-lysosome immobilization prevents it. We show that TPC-released Ca2+ rapidly activates calcineurin, which in turn dephosphorylates and activates the GTPase dynamin-2. Finally, we find that different endo-lysosomal Ca2+ channels play diverse roles, with TPCs providing a universal phagocytic signal for a wide range of particles and TRPML1 being only required for phagocytosis of large targets.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
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9
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Morgan AJ, Yuan Y, Patel S, Galione A. Does lysosomal rupture evoke Ca 2+ release? A question of pores and stores. Cell Calcium 2019; 86:102139. [PMID: 31881482 DOI: 10.1016/j.ceca.2019.102139] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 02/04/2023]
Abstract
Lysosomotropic agents have been used to permeabilize lysosomes and thereby implicate these organelles in diverse cellular processes. Since lysosomes are Ca2+ stores, this rupturing action, particularly that induced by GPN, has also been used to rapidly release Ca2+ from lysosomes. However, a recent study has questioned the mechanism of action of GPN and concluded that, acutely, it does not permeabilize lysosomes but releases Ca2+ directly from the ER instead. We therefore appraise these provocative findings in the context of the existing literature. We suggest that further work is required to unequivocally rule out lysosomes as contributors to GPN-evoked Ca2+ signals.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, United Kingdom.
| | - Yu Yuan
- Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, United Kingdom
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10
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Affiliation(s)
- AJ Morgan
- Specialist Registrar, Department of Anaesthesia and Intensive Care
Medicine, Sheffield Teaching Hospitals NHS Foundation
Trust, Herries Road, Sheffield S5 7AU,
UK
| | - AJ Glossop
- Consultant in Anaesthesia and Intensive Care Medicine, Department of Anaesthesia
and Intensive Care Medicine, Sheffield Teaching Hospitals NHS
Foundation Trust, Herries Road, Sheffield S5 7AU,
UK
- To whom correspondence should be addressed. Tel: +44 114 243 4343; Fax:
+44 114 2269342; E-mail:
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11
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Kille P, Morgan AJ, Powell K, Mosselmans JFW, Hart D, Gunning P, Hayes A, Scarborough D, McDonald I, Charnock JM. 'Venus trapped, Mars transits': Cu and Fe redox chemistry, cellular topography and in situ ligand binding in terrestrial isopod hepatopancreas. Open Biol 2016; 6:rsob.150270. [PMID: 26935951 PMCID: PMC4821242 DOI: 10.1098/rsob.150270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 11/18/2022] Open
Abstract
Woodlice efficiently sequester copper (Cu) in ‘cuprosomes' within hepatopancreatic ‘S' cells. Binuclear ‘B’ cells in the hepatopancreas form iron (Fe) deposits; these cells apparently undergo an apocrine secretory diurnal cycle linked to nocturnal feeding. Synchrotron-based µ-focus X-ray spectroscopy undertaken on thin sections was used to characterize the ligands binding Cu and Fe in S and B cells of Oniscus asellus (Isopoda). Main findings were: (i) morphometry confirmed a diurnal B-cell apocrine cycle; (ii) X-ray fluorescence (XRF) mapping indicated that Cu was co-distributed with sulfur (mainly in S cells), and Fe was co-distributed with phosphate (mainly in B cells); (iii) XRF mapping revealed an intimate morphological relationship between the basal regions of adjacent S and B cells; (iv) molecular modelling and Fourier transform analyses indicated that Cu in the reduced Cu+ state is mainly coordinated to thiol-rich ligands (Cu–S bond length 2.3 Å) in both cell types, while Fe in the oxidized Fe3+ state is predominantly oxygen coordinated (estimated Fe–O bond length of approx. 2 Å), with an outer shell of Fe scatterers at approximately 3.05 Å; and (v) no significant differences occur in Cu or Fe speciation at key nodes in the apocrine cycle. Findings imply that S and B cells form integrated unit-pairs; a functional role for secretions from these cellular units in the digestion of recalcitrant dietary components is hypothesized.
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Affiliation(s)
- P Kille
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - A J Morgan
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - K Powell
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - J F W Mosselmans
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK
| | - D Hart
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - P Gunning
- Smith and Nephew, Heslington, York Science Park, York YO10 5DF, UK
| | - A Hayes
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - D Scarborough
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - I McDonald
- School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff CF10 3AT, UK
| | - J M Charnock
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, UK
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12
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Fineran P, Lloyd-Evans E, Lack NA, Platt N, Davis LC, Morgan AJ, Höglinger D, Tatituri RVV, Clark S, Williams IM, Tynan P, Al Eisa N, Nazarova E, Williams A, Galione A, Ory DS, Besra GS, Russell DG, Brenner MB, Sim E, Platt FM. Pathogenic mycobacteria achieve cellular persistence by inhibiting the Niemann-Pick Type C disease cellular pathway. Wellcome Open Res 2016. [PMID: 28008422 DOI: 10.12688/wellcomeopenres.10036.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Tuberculosis remains a major global health concern. The ability to prevent phagosome-lysosome fusion is a key mechanism by which intracellular mycobacteria, including Mycobacterium tuberculosis, achieve long-term persistence within host cells. The mechanisms underpinning this key intracellular pro-survival strategy remain incompletely understood. Host macrophages infected with persistent mycobacteria share phenotypic similarities with cells taken from patients suffering from Niemann-Pick Disease Type C (NPC), a rare lysosomal storage disease in which endocytic trafficking defects and lipid accumulation within the lysosome lead to cell dysfunction and cell death. We investigated whether these shared phenotypes reflected an underlying mechanistic connection between mycobacterial intracellular persistence and the host cell pathway dysfunctional in NPC. METHODS The induction of NPC phenotypes in macrophages from wild-type mice or obtained from healthy human donors was assessed via infection with mycobacteria and subsequent measurement of lipid levels and intracellular calcium homeostasis. The effect of NPC therapeutics on intracellular mycobacterial load was also assessed. RESULTS Macrophages infected with persistent intracellular mycobacteria phenocopied NPC cells, exhibiting accumulation of multiple lipid types, reduced lysosomal Ca2+ levels, and defects in intracellular trafficking. These NPC phenotypes could also be induced using only lipids/glycomycolates from the mycobacterial cell wall. These data suggest that persistent intracellular mycobacteria inhibit the NPC pathway, likely via inhibition of the NPC1 protein, and subsequently induce altered acidic store Ca2+ homeostasis. Reduced lysosomal calcium levels may provide a mechanistic explanation for the reduced levels of phagosome-lysosome fusion in mycobacterial infection. Treatments capable of correcting defects in NPC mutant cells via modulation of host cell calcium were of benefit in promoting clearance of mycobacteria from infected host cells. CONCLUSION These findings provide a novel mechanistic explanation for mycobacterial intracellular persistence, and suggest that targeting interactions between the mycobacteria and host cell pathways may provide a novel avenue for development of anti-TB therapies.
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Affiliation(s)
- Paul Fineran
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Emyr Lloyd-Evans
- Department of Pharmacology, University of Oxford, Oxford, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Nathan A Lack
- Department of Pharmacology, University of Oxford, Oxford, UK.,School of Medicine, Koç University, Istanbul, Turkey
| | - Nick Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Doris Höglinger
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | | | - Ian M Williams
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Patricia Tynan
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Nada Al Eisa
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Evgeniya Nazarova
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Daniel S Ory
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, USA
| | - Gurdyal S Besra
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - David G Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | - Michael B Brenner
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Oxford, UK.,Faculty of Science Engineering and Computing, Kingston University, Kingston upon Thames, UK
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
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13
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Fineran P, Lloyd-Evans E, Lack NA, Platt N, Davis LC, Morgan AJ, Höglinger D, Tatituri RVV, Clark S, Williams IM, Tynan P, Al Eisa N, Nazarova E, Williams A, Galione A, Ory DS, Besra GS, Russell DG, Brenner MB, Sim E, Platt FM. Pathogenic mycobacteria achieve cellular persistence by inhibiting the Niemann-Pick Type C disease cellular pathway. Wellcome Open Res 2016; 1:18. [PMID: 28008422 PMCID: PMC5172425 DOI: 10.12688/wellcomeopenres.10036.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Tuberculosis remains a major global health concern. The ability to prevent phagosome-lysosome fusion is a key mechanism by which intracellular mycobacteria, including Mycobacterium tuberculosis, achieve long-term persistence within host cells. The mechanisms underpinning this key intracellular pro-survival strategy remain incompletely understood. Host macrophages infected with persistent mycobacteria share phenotypic similarities with cells taken from patients suffering from Niemann-Pick Disease Type C (NPC), a rare lysosomal storage disease in which endocytic trafficking defects and lipid accumulation within the lysosome lead to cell dysfunction and cell death. We investigated whether these shared phenotypes reflected an underlying mechanistic connection between mycobacterial intracellular persistence and the host cell pathway dysfunctional in NPC. METHODS The induction of NPC phenotypes in macrophages from wild-type mice or obtained from healthy human donors was assessed via infection with mycobacteria and subsequent measurement of lipid levels and intracellular calcium homeostasis. The effect of NPC therapeutics on intracellular mycobacterial load was also assessed. RESULTS Macrophages infected with persistent intracellular mycobacteria phenocopied NPC cells, exhibiting accumulation of multiple lipid types, reduced lysosomal Ca2+ levels, and defects in intracellular trafficking. These NPC phenotypes could also be induced using only lipids/glycomycolates from the mycobacterial cell wall. These data suggest that persistent intracellular mycobacteria inhibit the NPC pathway, likely via inhibition of the NPC1 protein, and subsequently induce altered acidic store Ca2+ homeostasis. Reduced lysosomal calcium levels may provide a mechanistic explanation for the reduced levels of phagosome-lysosome fusion in mycobacterial infection. Treatments capable of correcting defects in NPC mutant cells via modulation of host cell calcium were of benefit in promoting clearance of mycobacteria from infected host cells. CONCLUSION These findings provide a novel mechanistic explanation for mycobacterial intracellular persistence, and suggest that targeting interactions between the mycobacteria and host cell pathways may provide a novel avenue for development of anti-TB therapies.
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Affiliation(s)
- Paul Fineran
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Emyr Lloyd-Evans
- Department of Pharmacology, University of Oxford, Oxford, UK
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Nathan A. Lack
- Department of Pharmacology, University of Oxford, Oxford, UK
- School of Medicine, Koç University, Istanbul, Turkey
| | - Nick Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lianne C. Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Doris Höglinger
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | | | - Ian M. Williams
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Patricia Tynan
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Nada Al Eisa
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Evgeniya Nazarova
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Daniel S. Ory
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, USA
| | | | - David G. Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, USA
| | - Michael B. Brenner
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Oxford, UK
- Faculty of Science Engineering and Computing, Kingston University, Kingston upon Thames, UK
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14
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Reavley NJ, Jorm AF, Morgan AJ. Beliefs about dangerousness of people with mental health problems: the role of media reports and personal exposure to threat or harm. Soc Psychiatry Psychiatr Epidemiol 2016; 51:1257-64. [PMID: 27048265 DOI: 10.1007/s00127-016-1215-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 03/21/2016] [Indexed: 11/29/2022]
Abstract
PURPOSE To assess the associations between beliefs about the dangerousness of people with mental health problems and exposure to media reports of violence or personal experiences of fear, threat or harm. METHODS Telephone interviews were carried out with 5220 Australians aged 18+. Respondents heard a vignette of a person with depression or early schizophrenia and were asked whether they believed him to be dangerous. Other questions covered past 12-month recall of media reports of violence and mental health problems, contact with and experiences of fear, threat or harm by people with mental health problems. Multinomial logistic regression was used to assess the associations between beliefs about dangerousness and media and these types of contact with people with mental health problems. RESULTS For the early schizophrenia vignette, recall of media reports and having felt afraid of someone were associated with beliefs about dangerousness. For the depression vignette, media reports about violence and mental health problems or the experiences of feeling afraid or having been threatened or harmed were not strongly associated with beliefs about dangerousness. For both vignettes, knowing someone with a mental health problem and having a higher level of education were associated with less belief in dangerousness. CONCLUSIONS Media reports may play a greater role in forming attitudes in low prevalence disorders and further efforts to reduce any adverse impact of media reporting should focus on these disorders. The study also supports the effectiveness of contact with people with mental health problems in reducing beliefs about dangerousness.
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Affiliation(s)
- N J Reavley
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, 207 Bouverie Street, Parkville, Melbourne, VIC, 3010, Australia.
| | - A F Jorm
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, 207 Bouverie Street, Parkville, Melbourne, VIC, 3010, Australia
| | - A J Morgan
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, 207 Bouverie Street, Parkville, Melbourne, VIC, 3010, Australia.,School of Psychology and Public Health, La Trobe University, Bundoora, Australia
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15
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Abstract
Spontaneous Ca2+ waves, also termed store-overload-induced Ca2+ release (SOICR), in cardiac cells can trigger ventricular arrhythmias especially in failing hearts. SOICR occurs when RyRs are activated by an increase in sarcoplasmic reticulum (SR) luminal Ca2+. Carvedilol is one of the most effective drugs for preventing arrhythmias in patients with heart failure. Furthermore, carvedilol analogues with minimal β-blocking activity also block SOICR showing that SOICR-inhibiting activity is distinct from that for β-block. We show here that carvedilol is a potent inhibitor of cADPR-induced Ca2+ release in sea urchin egg homogenate. In addition, the carvedilol analog VK-II-86 with minimal β-blocking activity also suppresses cADPR-induced Ca2+ release. Carvedilol appeared to be a non-competitive antagonist of cADPR and could also suppress Ca2+ release by caffeine. These results are consistent with cADPR releasing Ca2+ in sea urchin eggs by sensitizing RyRs to Ca2+ involving a luminal Ca2+ activation mechanism. In addition to action on the RyR, we also observed inhibition of inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release by carvedilol suggesting a common mechanism between these evolutionarily related and conserved Ca2+ release channels.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Konstantina Bampali
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Cailley Factor
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - S R Wayne Chen
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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Arredouani A, Ruas M, Collins SC, Parkesh R, Clough F, Pillinger T, Coltart G, Rietdorf K, Royle A, Johnson P, Braun M, Zhang Q, Sones W, Shimomura K, Morgan AJ, Lewis AM, Chuang KT, Tunn R, Gadea J, Teboul L, Heister PM, Tynan PW, Bellomo EA, Rutter GA, Rorsman P, Churchill GC, Parrington J, Galione A. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) and Endolysosomal Two-pore Channels Modulate Membrane Excitability and Stimulus-Secretion Coupling in Mouse Pancreatic β Cells. J Biol Chem 2015; 290:21376-92. [PMID: 26152717 PMCID: PMC4571866 DOI: 10.1074/jbc.m115.671248] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Indexed: 12/02/2022] Open
Abstract
Pancreatic β cells are electrically excitable and respond to elevated glucose concentrations with bursts of Ca2+ action potentials due to the activation of voltage-dependent Ca2+ channels (VDCCs), which leads to the exocytosis of insulin granules. We have examined the possible role of nicotinic acid adenine dinucleotide phosphate (NAADP)-mediated Ca2+ release from intracellular stores during stimulus-secretion coupling in primary mouse pancreatic β cells. NAADP-regulated Ca2+ release channels, likely two-pore channels (TPCs), have recently been shown to be a major mechanism for mobilizing Ca2+ from the endolysosomal system, resulting in localized Ca2+ signals. We show here that NAADP-mediated Ca2+ release from endolysosomal Ca2+ stores activates inward membrane currents and depolarizes the β cell to the threshold for VDCC activation and thereby contributes to glucose-evoked depolarization of the membrane potential during stimulus-response coupling. Selective pharmacological inhibition of NAADP-evoked Ca2+ release or genetic ablation of endolysosomal TPC1 or TPC2 channels attenuates glucose- and sulfonylurea-induced membrane currents, depolarization, cytoplasmic Ca2+ signals, and insulin secretion. Our findings implicate NAADP-evoked Ca2+ release from acidic Ca2+ storage organelles in stimulus-secretion coupling in β cells.
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Affiliation(s)
- Abdelilah Arredouani
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom,
| | - Margarida Ruas
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Stephan C Collins
- the Centre des Sciences du Gout et de l'Alimentation, Equipe 5, 9E Boulevard Jeanne d'Arc 21000 Dijon, France
| | - Raman Parkesh
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Frederick Clough
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Toby Pillinger
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - George Coltart
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Katja Rietdorf
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Andrew Royle
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Paul Johnson
- the Nuffield Department of Surgery, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, United Kingdom
| | - Matthias Braun
- the The Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LJ, United Kingdom
| | - Quan Zhang
- the The Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LJ, United Kingdom
| | - William Sones
- the The Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LJ, United Kingdom
| | - Kenju Shimomura
- the Henry Wellcome Centre for Gene Function, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom
| | - Anthony J Morgan
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Alexander M Lewis
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Ruth Tunn
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Joaquin Gadea
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Lydia Teboul
- The Mary Lyon Centre, Medical Research Council Harwell, Oxfordshire OX11 0RD, United Kingdom
| | - Paula M Heister
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Patricia W Tynan
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Elisa A Bellomo
- the Centre des Sciences du Gout et de l'Alimentation, Equipe 5, 9E Boulevard Jeanne d'Arc 21000 Dijon, France
| | - Guy A Rutter
- the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Medicine, Imperial College London, Hammersmith Hospital, du Cane Road, London W12 0NN, United Kingdom, and
| | - Patrik Rorsman
- the The Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford OX3 7LJ, United Kingdom
| | - Grant C Churchill
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom,
| | - Antony Galione
- From the Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom,
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17
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Ruas M, Davis LC, Chen CC, Morgan AJ, Chuang KT, Walseth TF, Grimm C, Garnham C, Powell T, Platt N, Platt FM, Biel M, Wahl-Schott C, Parrington J, Galione A. Expression of Ca²⁺-permeable two-pore channels rescues NAADP signalling in TPC-deficient cells. EMBO J 2015; 34:1743-58. [PMID: 25872774 PMCID: PMC4516428 DOI: 10.15252/embj.201490009] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/11/2015] [Indexed: 01/26/2023] Open
Abstract
The second messenger NAADP triggers Ca2+ release from endo-lysosomes. Although two-pore channels (TPCs) have been proposed to be regulated by NAADP, recent studies have challenged this. By generating the first mouse line with demonstrable absence of both Tpcn1 and Tpcn2 expression (Tpcn1/2−/−), we show that the loss of endogenous TPCs abolished NAADP-dependent Ca2+ responses as assessed by single-cell Ca2+ imaging or patch-clamp of single endo-lysosomes. In contrast, currents stimulated by PI(3,5)P2 were only partially dependent on TPCs. In Tpcn1/2−/− cells, NAADP sensitivity was restored by re-expressing wild-type TPCs, but not by mutant versions with impaired Ca2+-permeability, nor by TRPML1. Another mouse line formerly reported as TPC-null likely expresses truncated TPCs, but we now show that these truncated proteins still support NAADP-induced Ca2+ release. High-affinity [32P]NAADP binding still occurs in Tpcn1/2−/− tissue, suggesting that NAADP regulation is conferred by an accessory protein. Altogether, our data establish TPCs as Ca2+-permeable channels indispensable for NAADP signalling.
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Affiliation(s)
- Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Cheng-Chang Chen
- Center for Integrated Protein Science CIPS-M and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, München, Germany
| | | | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Timothy F Walseth
- Pharmacology Department, University of Minnesota, Minneapolis, MN, USA
| | - Christian Grimm
- Center for Integrated Protein Science CIPS-M and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, München, Germany
| | - Clive Garnham
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Trevor Powell
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Nick Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Martin Biel
- Center for Integrated Protein Science CIPS-M and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, München, Germany
| | - Christian Wahl-Schott
- Center for Integrated Protein Science CIPS-M and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, München, Germany
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
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18
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19
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Galione A, Chuang KT, Funnell TM, Davis LC, Morgan AJ, Ruas M, Parrington J, Churchill GC. Synthesis of caged NAADP. Cold Spring Harb Protoc 2014; 2014:pdb.prot076943. [PMID: 25275103 DOI: 10.1101/pdb.prot076943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Caged derivatives of Ca²⁺-mobilizing messengers, such as nicotinic acid adenine dinucleotide phosphate (NAADP), are particularly useful for establishing the effects of these messengers on Ca²⁺ signaling. Caged NAADP is no longer commercially available but can be synthesized in house, as described here. In brief, a stable precursor of the caging reagent is made and converted to an unstable reactive reagent immediately before addition to the compound to be caged.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Tim M Funnell
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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20
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Galione A, Chuang KT, Funnell TM, Davis LC, Morgan AJ, Ruas M, Parrington J, Churchill GC. Measurement of luminal pH of acidic stores as a readout for NAADP action. Cold Spring Harb Protoc 2014; 2014:pdb.prot076935. [PMID: 25275102 DOI: 10.1101/pdb.prot076935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In addition to mobilizing Ca²⁺, NAADP plays a role in modulating the luminal pH (pHL) of acidic stores of the endolysosomal system. The effects of NAADP on pHL have been most extensively studied in the sea urchin egg, both in the intact egg and in egg homogenates. Related observations have also been made in mammalian systems (e.g., guinea pig atrial myocytes and pancreatic acinar cells). Although the connection between Ca²⁺ mobilization and increase in pHL is not understood, pHL can be a useful parameter to measure when studying NAADP-mediated signaling. This protocol describes the fluorescent measurement of pHL of acidic stores. It relies on the use of acridine orange (AO), a standard dye for pHL. AO selectively accumulates to high concentrations in the lumen of organelles as a function of acidity; at these high concentrations it self-quenches. When pHL increases, some AO is lost from the vesicle. As a result, the lower luminal AO concentration relieves the quenching and fluorescence increases in the lumen.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Tim M Funnell
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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21
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Galione A, Chuang KT, Funnell TM, Davis LC, Morgan AJ, Ruas M, Parrington J, Churchill GC. Synthesis of NAADP-AM as a membrane-permeant NAADP analog. Cold Spring Harb Protoc 2014; 2014:pdb.prot076927. [PMID: 25275101 DOI: 10.1101/pdb.prot076927] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nicotinic acid adenine dinucleotide phosphate (NAADP), like the other major messengers for Ca²⁺ mobilization, is passively membrane-impermeant. Instead, a cell-permeant acetoxymethyl ester derivative of NAADP (NAADP-AM) can be synthesized as described here and used to study NAADP-mediated Ca²⁺ release.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Tim M Funnell
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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22
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Galione A, Chuang KT, Funnell TM, Davis LC, Morgan AJ, Ruas M, Parrington J, Churchill GC. Synthesis of [³²P]NAADP for the radioreceptor binding assay. Cold Spring Harb Protoc 2014; 2014:993-5. [PMID: 25183813 DOI: 10.1101/pdb.prot076919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a major messenger for Ca(2+) mobilization in cells. NAADP-binding proteins are highly selective and have a strong affinity for NAADP. This is the basis of the radioreceptor binding assay, which is used to measure NAADP levels in cells and tissues and to identify cellular stimuli that use NAADP as an intracellular messenger. In the radioreceptor binding assay, radiolabeled NAADP ([(32)P]NAADP) competes with endogenous NAADP present in samples for binding to their receptors. Here, we describe the synthesis of [(32)P]NAADP for use in the radioreceptor binding assay.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Tim M Funnell
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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Galione A, Chuang KT, Funnell TM, Davis LC, Morgan AJ, Ruas M, Parrington J, Churchill GC. Preparation and use of sea urchin egg homogenates for studying NAADP-mediated Ca²⁺ release. Cold Spring Harb Protoc 2014; 2014:988-92. [PMID: 25183812 DOI: 10.1101/pdb.prot076901] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
NAADP and other Ca(2+)-mobilizing messengers are membrane impermeant and thus must be added directly to cell-free or broken-cell preparations to effect Ca(2+) release. The sea urchin egg homogenate, where the biological activity of NAADP was first reported, remains the gold standard cell-free system for studying NAADP-mediated Ca(2+) release. Here we describe how to prepare sea urchin egg homogenate and use it to measure NAADP-mediated Ca(2+) release.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Kai-Ting Chuang
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Tim M Funnell
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - John Parrington
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
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24
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Abstract
Cell homogenates provide a simple and yet powerful means of investigating the actions of Ca(2+)-mobilizing second messengers and their target Ca(2+) stores. The sea urchin egg homogenate is particularly useful and almost unique in retaining robust Ca(2+) responses to all three major messengers, i.e., inositol 1,4,5-trisphosphate (IP3), cyclic ADP-ribose, and nicotinic acid adenine dinucleotide phosphate (NAADP) (Lee and Aarhus. J Biol Chem 270: 2152-2172, 1995). It is not only invaluable for probing the pharmacology and mechanism of action of these messengers, but can also be used to assay Ca(2+) uptake mechanisms (Churchill et al. Cell 111: 703-708, 2002), second messenger production (Morgan et al. Methods in cADPR and NAADP research. In: Putney JW Jr (ed) Methods in calcium signalling, CRC: Boca Raton, FL, 2006), and dynamics of luminal pH (pHL) changes within acidic Ca(2+) stores (Lee and Epel. Dev Biol 98: 446-454, 1983; Morgan and Galione. Biochem J 402: 301-310, 2007). Here, we detail the protocols for preparing and using egg homogenates, wherein eggs are shed and collected into artificial sea water (ASW), dejellied, washed several times in Ca(2+)-free ASW, and then finally washed and resuspended in an intracellular-like medium. Homogenization is effected with a Dounce glass tissue homogenizer (at 50 % (v/v)) and aliquots frozen and stored at -80 °C. For Ca(2+) (or pHL) measurements, homogenate is thawed and sequentially diluted in an intracellular-like medium and the fluorescence of Ca(2+)- or pHL-sensitive dyes monitored in a standard fluorimeter or plate-reader.
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Abstract
Much excitement surrounded the proposal that a family of endo-lysosomal channels, the two-pore channels (TPCs) were the long sought after targets of the Ca(2+) -mobilising messenger, nicotinic acid adenine dinucleotide phosphate (NAADP). However, the role of TPCs in NAADP signalling may be more complex than originally envisaged. First, NAADP may not bind directly to TPCs but via an accessory protein. Second, two papers recently challenged the notion that TPCs are NAADP-regulated Ca(2+) channels by suggesting that they are highly selective Na(+) channels regulated by the lipid phosphatidylinositol 3,5-bisphosphate and by ATP. This paper aims critically to evaluate the evidence for TPCs as NAADP targets and to discuss how the new findings fit in with what we know about endo-lysosomal Ca(2+) stores.
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Abstract
The technique of protoplast fusion has been applied to the problem of unstable diploidy in the yeast Kluyveromyces lactis. By protoplast fusion between heterothallic strains of like mating-type, sporulation-deficient hybrids can be obtained. Biochemical, cytological, and genetical characterisation of these hybrids suggests that the majority of fusion products are diploid. Sporulating hybrids can be constructed by protoplast fusion between homothallic strains. Tetrad analysis of these hybrids demonstrates conclusively the diploid nature of fusion products.
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Affiliation(s)
- A J Morgan
- The School of Biological Sciences, University of Sussex, BN1 9QG, Falmer, Brighton, England
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Martin AV, Morgan AJ, Ekeberg T, Loh ND, Maia FRNC, Wang F, Spence JCH, Chapman HN. The extraction of single-particle diffraction patterns from a multiple-particle diffraction pattern. Opt Express 2013; 21:15102-15112. [PMID: 23842297 DOI: 10.1364/oe.21.015102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The structures of biological molecules may soon be determined with X-ray free-electron lasers without crystallization by recording the coherent diffraction patterns of many identical copies of a molecule. Most analysis methods require a measurement of each molecule individually. However, current injection methods deliver particles to the X-ray beam stochastically and the maximum yield of single particle measurements is 37% at optimal concentration. The remaining 63% of pulses intercept no particles or multiple particles. We demonstrate that in the latter case single particle diffraction patterns can be extracted provided the particles are sufficiently separated. The technique has the potential to greatly increase the amount of data available for three-dimensional imaging of identical particles with X-ray lasers.
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Affiliation(s)
- A V Martin
- ARC Centre of Excellence for Coherent X-ray Science, School of Physics, The University of Melbourne, Victoria, 3010, Australia.
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Morgan AJ, Davis LC, Wagner SKTY, Lewis AM, Parrington J, Churchill GC, Galione A. Bidirectional Ca²⁺ signaling occurs between the endoplasmic reticulum and acidic organelles. ACTA ACUST UNITED AC 2013; 200:789-805. [PMID: 23479744 PMCID: PMC3601362 DOI: 10.1083/jcb.201204078] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
After acidic organelles induce signaling to activate ER calcium ion release, local microdomains of high calcium at ER–acidic organelle junctions feed back to activate further acidic organelle calcium release. The endoplasmic reticulum (ER) and acidic organelles (endo-lysosomes) act as separate Ca2+ stores that release Ca2+ in response to the second messengers IP3 and cADPR (ER) or NAADP (acidic organelles). Typically, trigger Ca2+ released from acidic organelles by NAADP subsequently recruits IP3 or ryanodine receptors on the ER, an anterograde signal important for amplification and Ca2+ oscillations/waves. We therefore investigated whether the ER can signal back to acidic organelles, using organelle pH as a reporter of NAADP action. We show that Ca2+ released from the ER can activate the NAADP pathway in two ways: first, by stimulating Ca2+-dependent NAADP synthesis; second, by activating NAADP-regulated channels. Moreover, the differential effects of EGTA and BAPTA (slow and fast Ca2+ chelators, respectively) suggest that the acidic organelles are preferentially activated by local microdomains of high Ca2+ at junctions between the ER and acidic organelles. Bidirectional organelle communication may have wider implications for endo-lysosomal function as well as the generation of Ca2+ oscillations and waves.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, England, UK.
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Davis LC, Morgan AJ, Chen JL, Snead CM, Bloor-Young D, Shenderov E, Stanton-Humphreys MN, Conway SJ, Churchill GC, Parrington J, Cerundolo V, Galione A. NAADP activates two-pore channels on T cell cytolytic granules to stimulate exocytosis and killing. Curr Biol 2012. [PMID: 23177477 PMCID: PMC3525857 DOI: 10.1016/j.cub.2012.10.035] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A cytotoxic T lymphocyte (CTL) kills an infected or tumorigenic cell by Ca2+-dependent exocytosis of cytolytic granules at the immunological synapse formed between the two cells. Although inositol 1,4,5-trisphosphate (IP3)-mediated Ca2+ release from the endoplasmic reticulum activates the store-operated Ca2+-influx pathway that is necessary for exocytosis, it is not a sufficient stimulus [1–4]. Here we identify the Ca2+-mobilizing messenger nicotinic acid adenine dinucleotide phosphate (NAADP) and its recently identified molecular target, two-pore channels (TPCs) [5–7], as being important for T cell receptor signaling in CTLs. We demonstrate that cytolytic granules are not only reservoirs of cytolytic proteins but are also the acidic Ca2+ stores mobilized by NAADP via TPC channels on the granules themselves, so that TPCs migrate to the immunological synapse upon CTL activation. Moreover, NAADP activates TPCs to drive exocytosis in a way that is not mimicked by global Ca2+ signals induced by IP3 or ionomycin, suggesting that critical, local Ca2+ nanodomains around TPCs stimulate granule exocytosis. Hence, by virtue of the NAADP/TPC pathway, cytolytic granules generate Ca2+ signals that lead to their own exocytosis and to cell killing. This study highlights a selective role for NAADP in stimulating exocytosis crucial for immune cell function and may impact on stimulus-secretion coupling in wider cellular contexts.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK.
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Morgan AJ, Parrington J, Galione A. The luminal Ca(2+) chelator, TPEN, inhibits NAADP-induced Ca(2+) release. Cell Calcium 2012; 52:481-7. [PMID: 23099186 PMCID: PMC3526783 DOI: 10.1016/j.ceca.2012.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 08/06/2012] [Accepted: 09/19/2012] [Indexed: 10/31/2022]
Abstract
The regulation of Ca(2+) release by luminal Ca(2+) has been well studied for the ryanodine and IP(3) receptors but has been less clear for the NAADP-regulated channel. In view of conflicting reports, we have re-examined the issue by manipulating luminal Ca(2+) with the membrane-permeant, low affinity Ca(2+) buffer, TPEN, and monitoring NAADP-induced Ca(2+) release in sea urchin egg homogenate. NAADP-induced Ca(2+) release was almost entirely blocked by TPEN (IC(50) 17-25μM) which suppressed the maximal extent of Ca(2+) release without altering NAADP sensitivity. In contrast, Ca(2+) release via IP(3) receptors was 3- to 30-fold less sensitive to TPEN whereas that evoked by ionomycin was essentially unaffected. The effect of TPEN on NAADP-induced Ca(2+) release was not due to an increase in the luminal pH or chelation of trace metals since it could not be mimicked by NH(4)Cl or phenanthroline. The fact that TPEN had no effect upon ionophore-induced Ca(2+) release also argued against a substantial reduction in the driving force for Ca(2+) efflux. We propose that, in the sea urchin egg, luminal Ca(2+) is important for gating native NAADP-regulated two-pore channels.
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Morgan AJ, Poland GA. The Jenner Society and the Edward Jenner Museum: tributes to a physician-scientist. Vaccine 2012; 29 Suppl 4:D152-4. [PMID: 22486976 DOI: 10.1016/j.vaccine.2011.08.128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 08/01/2011] [Accepted: 08/02/2011] [Indexed: 10/28/2022]
Abstract
Dr. Edward Jenner's discovery and application of vaccination against smallpox was one of the most important medical advances of all time. In the modern era many millions of lives are saved each year by vaccines that work essentially on the same scientific principles established by Jenner more than 200 years ago. Jenner's country home in Berkeley, Gloucestershire, UK, where he carried out his work and where he spent most of his life, is now a museum and something of a shrine for vaccinologists. Jenner's house is also now the focal point of a new international learned society dedicated to advancing modern vaccinology. The aims of the new Jenner Society are to engage, support, and sustain the professional goals of vaccinologists, and to perpetuate the memory of Dr. Edward Jenner. Ultimately it is hoped that the Jenner Society will be recognized as one of the leading academic societies representing and promoting vaccine science around the world. We invite readers to consider joining the society (http://www.edwardjennersociety.org/).
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Affiliation(s)
- A J Morgan
- School of Cellular & Molecular Medicine, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
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Reavley NJ, Mackinnon AJ, Morgan AJ, Alvarez-Jimenez M, Hetrick SE, Killackey E, Nelson B, Purcell R, Yap MBH, Jorm AF. Quality of information sources about mental disorders: a comparison of Wikipedia with centrally controlled web and printed sources. Psychol Med 2012; 42:1753-1762. [PMID: 22166182 DOI: 10.1017/s003329171100287x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [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] [Indexed: 11/08/2022]
Abstract
BACKGROUND Although mental health information on the internet is often of poor quality, relatively little is known about the quality of websites, such as Wikipedia, that involve participatory information sharing. The aim of this paper was to explore the quality of user-contributed mental health-related information on Wikipedia and compare this with centrally controlled information sources. METHOD Content on 10 mental health-related topics was extracted from 14 frequently accessed websites (including Wikipedia) providing information about depression and schizophrenia, Encyclopaedia Britannica, and a psychiatry textbook. The content was rated by experts according to the following criteria: accuracy, up-to-dateness, breadth of coverage, referencing and readability. RESULTS Ratings varied significantly between resources according to topic. Across all topics, Wikipedia was the most highly rated in all domains except readability. CONCLUSIONS The quality of information on depression and schizophrenia on Wikipedia is generally as good as, or better than, that provided by centrally controlled websites, Encyclopaedia Britannica and a psychiatry textbook.
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Affiliation(s)
- N J Reavley
- Orygen Youth Health Research Centre, Centre for Youth Mental Health, University of Melbourne, Parkville, VIC, Australia.
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Abstract
Sea urchin eggs have been an indispensable model system for studying egg activation and ionic signalling for at least a century. Instrumental in the discovery of two Ca(2+)-mobilizing second messengers, cyclic ADP-ribose and NAADP, the sea urchin has revolutionized cell biology for all phyla. This review attempts to summarize what we currently know about egg acidic vesicles in the context of Ca(2+) signalling. The dynamics of Ca(2+) storage, Ca(2+) mobilization, proton fluxes and two-pore channels will be discussed.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, United Kingdom.
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35
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Ruas M, Rietdorf K, Arredouani A, Davis LC, Lloyd-Evans E, Koegel H, Funnell TM, Morgan AJ, Ward JA, Watanabe K, Cheng X, Churchill GC, Zhu MX, Platt FM, Wessel GM, Parrington J, Galione A. Purified TPC isoforms form NAADP receptors with distinct roles for Ca(2+) signaling and endolysosomal trafficking. Curr Biol 2010; 20:703-9. [PMID: 20346675 PMCID: PMC2861162 DOI: 10.1016/j.cub.2010.02.049] [Citation(s) in RCA: 214] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 01/07/2010] [Accepted: 02/09/2010] [Indexed: 11/29/2022]
Abstract
Intracellular Ca2+ signals constitute key elements in signal transduction. Of the three major Ca2+ mobilizing messengers described, the most potent, nicotinic acid adenine dinucleotide phosphate (NAADP) is the least well understood in terms of its molecular targets [1]. Recently, we showed that heterologous expression of two-pore channel (TPC) proteins enhances NAADP-induced Ca2+ release, whereas the NAADP response was abolished in pancreatic beta cells from Tpcn2 gene knockout mice [2]. However, whether TPCs constitute native NAADP receptors is unclear. Here we show that immunopurified endogenous TPC complexes possess the hallmark properties ascribed to NAADP receptors, including nanomolar ligand affinity [3–5]. Our study also reveals important functional differences between the three TPC isoforms. Thus, TPC1 and TPC2 both mediate NAADP-induced Ca2+ release, but the subsequent amplification of this trigger Ca2+ by IP3Rs is more tightly coupled for TPC2. In contrast, TPC3 expression suppressed NAADP-induced Ca2+ release. Finally, increased TPC expression has dramatic and contrasting effects on endolysosomal structures and dynamics, implicating a role for NAADP in the regulation of vesicular trafficking. We propose that NAADP regulates endolysosomal Ca2+ storage and release via TPCs and coordinates endoplasmic reticulum Ca2+ release in a role that impacts on Ca2+ signaling in health and disease [6].
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Affiliation(s)
- Margarida Ruas
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
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Andre J, King RA, Stürzenbaum SR, Kille P, Hodson ME, Morgan AJ. Molecular genetic differentiation in earthworms inhabiting a heterogeneous Pb-polluted landscape. Environ Pollut 2010; 158:883-890. [PMID: 19818541 DOI: 10.1016/j.envpol.2009.09.021] [Citation(s) in RCA: 12] [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] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 09/16/2009] [Accepted: 09/17/2009] [Indexed: 05/28/2023]
Abstract
A Pb-mine site situated on acidic soil, but comprising of Ca-enriched islands around derelict buildings was used to study the spatial pattern of genetic diversity in Lumbricus rubellus. Two distinct genetic lineages ('A' and 'B'), differentiated at both the mitochondrial (mtDNA COII) and nuclear level (AFLPs) were revealed with a mean inter-lineage mtDNA sequence divergence of approximately 13%, indicative of a cryptic species complex. AFLP analysis indicates that lineage A individuals within one central 'ecological island' site are uniquely clustered, with little genetic overlap with lineage A individuals at the two peripheral sites. FTIR microspectroscopy of Pb-sequestering chloragocytes revealed different phosphate profiles in residents of adjacent acidic and calcareous islands. Bioinformatics found over-representation of Ca pathway genes in EST(Pb) libraries. Subsequent sequencing of a Ca-transport gene, SERCA, revealed mutations in the protein's cytosolic domain. We recommend the mandatory genotyping of all individuals prior to field-based ecotoxicological assays, particularly those using discriminating genomic technologies.
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Affiliation(s)
- J Andre
- Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL, UK.
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Chen JL, Morgan AJ, Stewart-Jones G, Shepherd D, Bossi G, Wooldridge L, Hutchinson SL, Sewell AK, Griffiths GM, van der Merwe PA, Jones EY, Galione A, Cerundolo V. Ca2+ release from the endoplasmic reticulum of NY-ESO-1-specific T cells is modulated by the affinity of TCR and by the use of the CD8 coreceptor. J Immunol 2010; 184:1829-1839. [PMID: 20053942 PMCID: PMC4222200 DOI: 10.4049/jimmunol.0902103] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although several cancer immunotherapy strategies are based on the use of analog peptides and on the modulation of the TCR affinity of adoptively transferred T cells, it remains unclear whether tumor-specific T cell activation by strong and weak TCR stimuli evoke different Ca(2+) signatures from the Ca(2+) intracellular stores and whether the amplitude of Ca(2+) release from the endoplasmic reticulum (ER) can be further modulated by coreceptor binding to peptide/MHC. In this study, we combined functional, structural, and kinetic measurements to correlate the intensity of Ca(2+) signals triggered by the stimulation of the 1G4 T cell clone specific to the tumor epitope NY-ESO-1(157-165). Two analogs of the NY-ESO-1(157-165) peptide, having similar affinity to HLA-A2 molecules, but a 6-fold difference in binding affinity for the 1G4 TCR, resulted in different Ca(2+) signals and T cell activation. 1G4 stimulation by the stronger stimulus emptied the ER of stored Ca(2+), even in the absence of CD8 binding, resulting in sustained Ca(2+) influx. In contrast, the weaker stimulus induced only partial emptying of stored Ca(2+), resulting in significantly diminished and oscillatory Ca(2+) signals, which were enhanced by CD8 binding. Our data define the range of TCR/peptide MHC affinities required to induce depletion of Ca(2+) from intracellular stores and provide insights into the ability of T cells to tailor the use of the CD8 coreceptor to enhance Ca(2+) release from the ER. This, in turn, modulates Ca(2+) influx from the extracellular environment, ultimately controlling T cell activation.
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Affiliation(s)
- Ji-Li Chen
- Weatherall Institute of Molecular Medicine, OX3 9DS, Oxford
| | - Anthony J. Morgan
- Dept of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Guillaume Stewart-Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Dawn Shepherd
- Weatherall Institute of Molecular Medicine, OX3 9DS, Oxford
| | - Giovanna Bossi
- Immunocore, Limited, 57c Milton Park, Abingdon, Oxon, OX14 4RX, UK
| | - Linda Wooldridge
- Dept of Infection, Immunity and Biochemistry, The Henry Wellcome Building, Cardiff University School of Medicine, Cardiff, CF14 4XN
| | | | - Andrew K. Sewell
- Dept of Infection, Immunity and Biochemistry, The Henry Wellcome Building, Cardiff University School of Medicine, Cardiff, CF14 4XN
| | - Gillian M. Griffiths
- Cambridge Institute for Medical Research, PO Box 139, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 0XY, UK
| | | | - E. Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Antony Galione
- Dept of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
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Langdon CJ, Morgan AJ, Charnock JM, Semple KT, Lowe CN. As-resistance in laboratory-reared F1, F2 and F3 generation offspring of the earthworm Lumbricus rubellus inhabiting an As-contaminated mine soil. Environ Pollut 2009; 157:3114-3119. [PMID: 19501438 DOI: 10.1016/j.envpol.2009.05.027] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/08/2009] [Accepted: 05/10/2009] [Indexed: 05/27/2023]
Abstract
Previous studies provided no unequivocal evidence demonstrating that field populations of Lumbricus rubellus Hoffmeister (1843), exhibit genetically inherited resistance to As-toxicity. In this study F1, F2 and F3 generation offspring derived from adults inhabiting As-contaminated field soil were resistant when exposed to 2000 mg kg(-1) sodium arsenate. The offspring of uncontaminated adults were not As-resistant. Cocoon viability was 80% for F1 and 82% for F2 offspring from As-contaminated adults and 59% in the F1 control population. High energy synchrotron analysis was used to determine whether ligand complexation of As differed in samples of: resistant mine-site adults, the resistant F1 and F2 offspring of the mine-site earthworms exposed to the LC(25) sodium arsenate (700 mg kg(-1)) of the F1 parental generation; and adult L. rubellus from an uncontaminated site exposed to LC(25) concentrations of sodium arsenate (50 mg kg(-1)). XANES and EXAFS indicated that As was present as a sulfur-coordinated species.
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Affiliation(s)
- C J Langdon
- C/O The Open University in the North, Baltic Buiness Quarter, Gateshead, UK.
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Abstract
Small incremental biological change, winnowed by natural selection over geological time scales to produce large consequences, was Darwin's singular insight that revolutionized the life sciences. His publications after 1859, including the ‘earthworm book’, were all written to amplify and support the evolutionary theory presented in the Origin. Darwin was unable to provide a physical basis for the inheritance of favoured traits because of the absence of genetic knowledge that much later led to the ‘modern synthesis’. Mistaken though he was in advocating systemic ‘gemmules’ as agents of inheritance, Darwin was perceptive in seeking to underpin his core vision with concrete factors that both determine the nature of a trait in one generation and convey it to subsequent generations. This brief review evaluates the molecular genetic literature on earthworms published during the last decade, and casts light on the specific aspects of earthworm evolutionary biology that more or less engaged Darwin: (i) biogeography, (ii) species diversity, (iii) local adaptations and (iv) sensitivity. We predict that the current understanding will deepen with the announcement of a draft earthworm genome in Darwin's bicentenary year, 2009. Subsequently, the earthworm may be elevated from the status of a soil sentinel to that elusive entity, an ecologically relevant genetic model organism.
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Affiliation(s)
- S R Stürzenbaum
- School of Biomedical & Health Sciences, King's College London, London SE1 9NH, UK.
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40
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Abstract
The body of literature characterizing cyclic adenosine diphosphoribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) as Ca2+-mobilizing second messengers is growing apace. However, their unique properties may, for the uninitiated, make them difficult to work with. This article reviews many of the available techniques (and associated pitfalls) for investigating these nucleotide messengers, predominantly focusing upon optical techniques using fluorescent reporters to measure Ca2+ in the cytosol as well as Ca2+ or pH within the lumen of intracellular organelles.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, Oxon OX1 3QT, UK.
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Svendsen C, Owen J, Kille P, Wren J, Jonker MJ, Headley BA, Morgan AJ, Blaxter M, Stürzenbaum SR, Hankard PK, Lister LJ, Spurgeon DJ. Comparative transcriptomic responses to chronic cadmium, fluoranthene, and atrazine exposure in Lumbricus rubellus. Environ Sci Technol 2008; 42:4208-14. [PMID: 18589989 DOI: 10.1021/es702745d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Transcriptional responses of a soil-dwelling organism (the earthworm Lumbricus rubellus) to three chemicals, cadmium (Cd), fluoranthene (FA), and atrazine (AZ), were measured following chronic exposure, with the aim of identifying the nature of any shared transcriptional response. Principal component analysis indicated full or partial separation of control and exposed samples for each compound but not for the composite set of all control and exposed samples. Partial least-squares discriminant analysis allowed separation of the control and exposed samples for each chemical and also for the composite data set, suggesting a common transcriptional response to exposure. Genes identified as changing in expression level (by the least stringent test for significance) following exposure to two chemicals indicated a substantial number of common genes (> 127). The three compound overlapping gene set, however, comprised only 25 genes. We suggest that the low commonality in transcriptional response may be linked to the chronic concentrations (approximately 10% EC50) and chronic duration (28 days) used. Annotations of the three compound overlapping gene set indicated that genes from pathways most often associated with responses to environmental stress, such as heat shock, phase I and II metabolism, antioxidant defense, and cation balance, were not represented. The strongest annotation signature was for genes important in mitochondrial function and energy metabolism.
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Affiliation(s)
- C Svendsen
- Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS, United Kingdom
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Zhang B, Wagner GK, Weber K, Garnham C, Morgan AJ, Galione A, Guse AH, Potter BVL. 2'-deoxy cyclic adenosine 5'-diphosphate ribose derivatives: importance of the 2'-hydroxyl motif for the antagonistic activity of 8-substituted cADPR derivatives. J Med Chem 2008; 51:1623-36. [PMID: 18303825 DOI: 10.1021/jm7010386] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structural features needed for antagonism at the cyclic ADP-ribose (cADPR) receptor are unclear. Chemoenzymatic syntheses of novel 8-substituted 2'-deoxy-cADPR analogues, including 8-bromo-2'-deoxy-cADPR 7, 8-amino-2'-deoxy-cADPR 8, 8- O-methyl-2'-deoxy-cADPR 9, 8-phenyl-2'-deoxy-cADPR 10 and its ribose counterpart 8-phenyl-cADPR 5 are reported, including improved syntheses of established antagonists 8-amino-cADPR 2 and 8-bromo-cADPR 3. Aplysia californica ADP-ribosyl cyclase tolerates even the bulky 8-phenyl-nicotinamide adenine 5'-dinucleotide as a substrate. Structure-activity relationships of 8-substituted cADPR analogues in both Jurkat T-lymphocytes and sea urchin egg homogenate (SUH) were investigated. 2'-OH Deletion decreased antagonistic activity (at least for the 8-amino series), showing it to be an important motif. Some 8-substituted 2'-deoxy analogues showed agonist activity at higher concentrations, among which 8-bromo-2'-deoxy-cADPR 7 was, unexpectedly, a weak but almost full agonist in SUH and was membrane-permeant in whole eggs. Classical antagonists 2 and 3 also showed previously unobserved agonist activity at higher concentrations in both systems. The 2'-OH group, without effect on the Ca (2+)-mobilizing ability of cADPR itself, is an important motif for the antagonistic activities of 8-substituted cADPR analogues.
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Affiliation(s)
- Bo Zhang
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, UK
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Morgan AJ, Galione A. Fertilization and nicotinic acid adenine dinucleotide phosphate induce pH changes in acidic Ca(2+) stores in sea urchin eggs. J Biol Chem 2007; 282:37730-7. [PMID: 17959608 DOI: 10.1074/jbc.m704630200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The second messenger nicotinic acid adenine dinucleotide phosphate (NAADP) releases Ca(2+) from the acidic Ca(2+) stores of many organisms, including those of the sea urchin egg. We investigated whether the pH within the lumen of these acidic organelles changes in response to stimuli. Fertilization activates the egg by Ca(2+) release dependent upon NAADP, and accordingly, we report that fertilization also alters organellar pH in a spatio-temporally complex manner. Upon sperm fusion, vesicles deep in the egg center slowly acidify, whereas cortical vesicles undergo a rapid alkalinization. The cortical vesicle alkalinization is independent of exocytosis and cytosolic pH but coincides with the NAADP-dependent fertilization Ca(2+) wave. Microinjection of NAADP mimicked the fertilization cortical response, suggesting that it occurred within NAADP-sensitive acidic Ca(2+) stores. Our data show that NAADP and physiological stimuli alter the pH within intracellular organelles and suggest that NAADP signals through pH as well as Ca(2+).
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Abstract
Edward Jenner's discovery of vaccination must rank as one of the most important medical advances of all time and is a prominent example of the power of rational enquiry being brought to bear during the Age of Enlightenment in 18th century Europe. In the modern era many millions of lives are saved each year by vaccines that work essentially on the same principles that were established by Edward Jenner more than 200 years ago. His country home in Berkeley, Gloucestershire, is where he carried out his work and where he spent most of his life. The building is now a museum in which the life and times of Jenner are commemorated including not only the discovery of smallpox vaccination but also his other important scientific contributions to natural history and medicine. The trustees of the Edward Jenner museum are committed to promoting the museum as a real and "virtual" educational centre that is both entertaining and informative.
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Affiliation(s)
- A J Morgan
- Department of Cellular and Molecular Medicine, School of Medical and Veterinary Sciences, University of Bristol, UK.
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Abstract
NAADP (nicotinic acid-adenine dinucleotide phosphate)-induced Ca2+ release has been proposed to occur selectively from acidic stores in several cell types, including sea urchin eggs. Using fluorescence measurements, we have investigated whether NAADP-induced Ca2+ release alters the pH(L) (luminal pH) within these acidic stores in egg homogenates and observed their prompt, concentration-dependent alkalinization by NAADP (but not beta-NAD+ or NADP). Like Ca2+ release, the pH(L) change was desensitized by low concentrations of NAADP suggesting it was secondary to NAADP receptor activation. Moreover, this was a direct effect of NAADP upon the acidic stores and not secondary to increases in cytosolic Ca2+ as it was not mimicked by IP3 (inositol 1,4,5-trisphosphate), cADPR (cyclic adenine diphosphoribose), ionomycin, thapsigargin or by direct addition of Ca2+, and was not blocked by EGTA. The results of the present study further support acidic stores as targets for NAADP and for the first time reveal an adjunct role for NAADP in regulating the pH(L) of intracellular organelles.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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Morgan AJ, Guillen C, Symon FA, Huynh TT, Berry MA, Entwisle JJ, Briskin M, Pavord ID, Wardlaw AJ. Expression of CXCR6 and its ligand CXCL16 in the lung in health and disease. Clin Exp Allergy 2006; 35:1572-80. [PMID: 16393323 DOI: 10.1111/j.1365-2222.2005.02383.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Chemokine receptors (CR) play an important role in T cell migration, but their contribution to lung trafficking is unclear. OBJECTIVE We hypothesized that if a particular CR was involved in T cell homing its expression would be enriched on lung T cells compared with peripheral blood T cells (PBT). METHODS We have measured the CR expression on BAL T cells from patients with sarcoid, other interstitial lung diseases (ILD), asthma and healthy volunteers. RESULTS Of 14 CR studied in sarcoid, CXCR6 expression was the most markedly increased in the lung compared with the blood, a finding that was also seen in ILD patients. A striking although lesser increase was also seen in asthmatics and healthy controls. Analysis of expression of the CXCR6 ligand, CXCL16, by immunohistochemistry suggested that alveolar macrophages (AM) were the major source of CXCL16 in the lung. AM expressed mRNA for CXCL16 and released nanogram quantities after adhesion to plastic as shown by RT-PCR, Western blotting and ELISA. Bronchoalveolar lavage (BAL) fluid from all subjects contained large amounts of CXCL16. The full-length CXCL16 was the predominant isoform in AM lysates, supernatants and BAL. CONCLUSION This data suggests that CXCR6 and CXCL16 may play a role in T cell recruitment to the lung.
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MESH Headings
- Adult
- Asthma/immunology
- Biomarkers/analysis
- Blotting, Western
- Bronchoalveolar Lavage Fluid/chemistry
- Case-Control Studies
- Chemokine CXCL16
- Chemokines, CXC/analysis
- Chemokines, CXC/blood
- Chemokines, CXC/genetics
- Female
- Flow Cytometry
- Humans
- Immunohistochemistry/methods
- Lung/immunology
- Lung Diseases/immunology
- Lymphocyte Count
- Macrophages, Alveolar/immunology
- Male
- Pulmonary Fibrosis/immunology
- RNA, Messenger/analysis
- Receptors, CXCR6
- Receptors, Chemokine
- Receptors, Cytokine/analysis
- Receptors, Cytokine/blood
- Receptors, Cytokine/genetics
- Receptors, G-Protein-Coupled/analysis
- Receptors, G-Protein-Coupled/blood
- Receptors, G-Protein-Coupled/genetics
- Receptors, Scavenger/analysis
- Receptors, Scavenger/blood
- Receptors, Scavenger/genetics
- Receptors, Virus/analysis
- Receptors, Virus/blood
- Receptors, Virus/genetics
- Sarcoidosis/immunology
- T-Lymphocytes/chemistry
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Affiliation(s)
- A J Morgan
- Institute for Lung Health, Department of Infection, Immunity and Inflammation, Leicester University, Glenfield Hospital, Leicester, UK
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Morgan AJ, Thomas AP. Single-cell and subcellular measurement of intracellular Ca2+ concentration. Methods Mol Biol 2006; 312:87-117. [PMID: 16422192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Affiliation(s)
- Anthony J Morgan
- Physiology Group, Vascular Biology Research Centre, Biomedical Sciences Division, King's College London, UK
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Morgan AJ, Turner MP. Quantitative ultrastructure of metal-sequestering cells reflects intersite and interspecies differences in earthworm metal burdens. Arch Environ Contam Toxicol 2005; 49:45-52. [PMID: 15981036 DOI: 10.1007/s00244-004-0012-5] [Citation(s) in RCA: 1] [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] [Subscribe] [Scholar Register] [Received: 02/01/2004] [Accepted: 08/10/2004] [Indexed: 05/03/2023]
Abstract
Morphometric analysis of transmission electron micrographs was used to compare the effects of metals on the multifunctional, metal-sequestering, chloragocyte cells of two epigeic earthworm species, Dendrodrilus rubidus and Lumbricus rubellus, inhabiting three field soils: a clean circumneutral reference soil (Dinas Powys); an acidic moderately Pb- and Zn-contaminated soil (Cwmystwyth); and a calcareous Cd-, Pb-, and Zn-contaminated soil (Draethen). The main findings were: (1) D. rubidus accumulated significantly higher tissue Cd and Pb and lower Zn concentrations than L. rubellus, especially at Draethen; (2) the volume fraction of chloragosomes was significantly lower and the volume fraction of debris vesicles significantly higher in D. rubidus from Draethen compared with L. rubellus at all sites and with the other two D. rubidus populations; (3) estimated relative toxicity factors, derived from soil metal concentrations and published EC50 data, suggested that the subcellular changes in chloragocytes, particularly in D. rubidus from Draethen, were caused mainly by Zn and Pb exposures; (4) scrutiny of the body burdens of each metal in both worm species across the three sites indicated that Cd was a major contributor to the structural changes observed in Draethen D. rubidus, and its impact was disproportionate to its soil and tissue concentrations in comparison with those of Pb and Zn. The apparent greater susceptibility of D. rubidus cells, compared with L. rubellus cells, to soil metal contaminants is discussed in light of differences in the quality and quantity of the metal body burdens accumulated by the two species. Further histopathalogic and morphometric studies on key organs and tissue of earthworms are required to provide biomarkers of exposure and to underpin linkage of biochemical-level changes and demography.
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Affiliation(s)
- A J Morgan
- Cardiff School of Biosciences, Cardiff University, P.O. Box 915, Cardiff CF10 3TL, Wales, UK.
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49
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Langdon CJ, Winters C, Stürzenbaum SR, Morgan AJ, Charnock JM, Meharg AA, Piearce TG, Lee PH, Semple KT. Ligand arsenic complexation and immunoperoxidase detection of metallothionein in the earthworm Lumbricus rubellus inhabiting arsenic-rich soil. Environ Sci Technol 2005; 39:2042-8. [PMID: 15871235 DOI: 10.1021/es0490471] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Although earthworms have been found to inhabit arsenic-rich soils in the U.K., the mode of arsenic detoxification is currently unknown. Biochemical analyses and subcellular localization studies have indicated that As3+-thiol complexes may be involved; however, it is not known whether arsenic is capable of inducing the expression of metallothionein (MT) in earthworms. The specific aims of this paper were (a) to detect and gain an atomic characterization of ligand complexing by X-ray absorption spectrometry (XAS), and (b) to employ a polyclonal antibody raised against an earthworm MT isoform (w-MT2) to detect and localize the metalloprotein by immunoperoxidase histochemistry in the tissues of earthworms sampled from arsenic-rich soil. Data suggested that the proportion of arsenate to sulfur-bound species varies within specific earthworm tissues. Although some arsenic appeared to be in the form of arsenobetaine, the arsenic within the chlorogogenous tissue was predominantly coordinated with S in the form of -SH groups. This suggests the presence of an As::MT complex. Indeed, MT was detectable with a distinctly localized tissue and cellular distribution. While MT was not detectable in the surface epithelium or in the body wall musculature, immunoperoxidase histochemistry identified the presence of MT in chloragocytes around blood vessels, within the typhlosolar fold, and in the peri-intestinal region. Focal immunostaining was also detectable in a cohort of cells in the intestinal wall. The results of this study support the hypothesis that arsenic induces MT expression and is sequestered by the metalloprotein in certain target cells and tissues.
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Affiliation(s)
- C J Langdon
- Department of Environmental Management, School of Natural Resources, University of Central Lancashire, Preston, Lancashire, PR1 2HE, UK.
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50
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Morgan AJ, Thomas AP. Single-cell and subcellular measurement of intracellular Ca²+ concentration. Methods Mol Biol 2005; 312:87-117. [PMID: 21341093 DOI: 10.1385/1-59259-949-4:087] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Measurement of the intracellular Ca(2+) concentration ([Ca(2+)](i)) in populations of cells is an excellent tool to complement population measurements of other cell parameters, but the usefulness of this approach is limited by several problems, not the least of which is temporal averaging. In population studies, agonists often evoke a characteristic peak and plateau type of response irrespective of the stimulus intensity. However, equivalent experiments using single cells can often reveal exceedingly complex patterns, such as oscillations of the cytosolic Ca(2+) concentration ([Ca(2+)](c)). By and large these patterns cannot be observed in population studies since cells oscillate out of phase and at different frequencies, resulting in a smooth population average. It is only when cells are electrically well coupled that synchronized, population oscillations can be recorded, but this case is more the exception than the rule.
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Affiliation(s)
- Anthony J Morgan
- Physiology Group, Vascular Biology Research Centre, Biomedical Sciences Division, King's College London, London, UK
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