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Martelli F, Lin J, Mele S, Imlach W, Kanca O, Barlow CK, Paril J, Schittenhelm RB, Christodoulou J, Bellen HJ, Piper MDW, Johnson TK. Identifying potential dietary treatments for inherited metabolic disorders using Drosophila nutrigenomics. Cell Rep 2024; 43:113861. [PMID: 38416643 PMCID: PMC11037929 DOI: 10.1016/j.celrep.2024.113861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 12/09/2023] [Accepted: 02/08/2024] [Indexed: 03/01/2024] Open
Abstract
Inherited metabolic disorders are a group of genetic conditions that can cause severe neurological impairment and child mortality. Uniquely, these disorders respond to dietary treatment; however, this option remains largely unexplored because of low disorder prevalence and the lack of a suitable paradigm for testing diets. Here, we screened 35 Drosophila amino acid disorder models for disease-diet interactions and found 26 with diet-altered development and/or survival. Using a targeted multi-nutrient array, we examine the interaction in a model of isolated sulfite oxidase deficiency, an infant-lethal disorder. We show that dietary cysteine depletion normalizes their metabolic profile and rescues development, neurophysiology, behavior, and lifelong fly survival, thus providing a basis for further study into the pathogenic mechanisms involved in this disorder. Our work highlights the diet-sensitive nature of metabolic disorders and establishes Drosophila as a valuable tool for nutrigenomic studies for informing potential dietary therapies.
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Affiliation(s)
- Felipe Martelli
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Jiayi Lin
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Sarah Mele
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Wendy Imlach
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Oguz Kanca
- Department of Molecular and Human Genetics and Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - Christopher K Barlow
- Monash Proteomics & Metabolomics Facility, Monash Biomedicine Discovery Institute & Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Jefferson Paril
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Ralf B Schittenhelm
- Monash Proteomics & Metabolomics Facility, Monash Biomedicine Discovery Institute & Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - John Christodoulou
- Murdoch Children's Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Hugo J Bellen
- Department of Molecular and Human Genetics and Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - Matthew D W Piper
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia; Department of Biochemistry and Chemistry and La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia.
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2
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Wall MJ, Hill E, Huckstepp R, Barkan K, Deganutti G, Leuenberger M, Preti B, Winfield I, Carvalho S, Suchankova A, Wei H, Safitri D, Huang X, Imlach W, La Mache C, Dean E, Hume C, Hayward S, Oliver J, Zhao FY, Spanswick D, Reynolds CA, Lochner M, Ladds G, Frenguelli BG. Selective activation of Gαob by an adenosine A 1 receptor agonist elicits analgesia without cardiorespiratory depression. Nat Commun 2022; 13:4150. [PMID: 35851064 PMCID: PMC9293909 DOI: 10.1038/s41467-022-31652-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 06/23/2022] [Indexed: 02/06/2023] Open
Abstract
The development of therapeutic agonists for G protein-coupled receptors (GPCRs) is hampered by the propensity of GPCRs to couple to multiple intracellular signalling pathways. This promiscuous coupling leads to numerous downstream cellular effects, some of which are therapeutically undesirable. This is especially the case for adenosine A1 receptors (A1Rs) whose clinical potential is undermined by the sedation and cardiorespiratory depression caused by conventional agonists. We have discovered that the A1R-selective agonist, benzyloxy-cyclopentyladenosine (BnOCPA), is a potent and powerful analgesic but does not cause sedation, bradycardia, hypotension or respiratory depression. This unprecedented discrimination between native A1Rs arises from BnOCPA's unique and exquisitely selective activation of Gob among the six Gαi/o subtypes, and in the absence of β-arrestin recruitment. BnOCPA thus demonstrates a highly-specific Gα-selective activation of the native A1R, sheds new light on GPCR signalling, and reveals new possibilities for the development of novel therapeutics based on the far-reaching concept of selective Gα agonism.
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Affiliation(s)
- Mark J Wall
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK.
| | - Emily Hill
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Robert Huckstepp
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Kerry Barkan
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Giuseppe Deganutti
- Centre for Sport, Exercise and Life Sciences (CSELS), Faculty of Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Michele Leuenberger
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012, Bern, Switzerland
| | - Barbara Preti
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012, Bern, Switzerland
| | - Ian Winfield
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Sabrina Carvalho
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Anna Suchankova
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | | | - Dewi Safitri
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
- Pharmacology and Clinical Pharmacy Research Group, School of Pharmacy, Bandung Institute of Technology, Bandung, 40132, Indonesia
| | - Xianglin Huang
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Wendy Imlach
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Innovation Walk, Clayton, VIC, 3800, Australia
| | - Circe La Mache
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Eve Dean
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Cherise Hume
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Stephanie Hayward
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Jess Oliver
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | | | - David Spanswick
- NeuroSolutions Ltd, Coventry, UK
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Innovation Walk, Clayton, VIC, 3800, Australia
- Warwick Medical School, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK
| | - Christopher A Reynolds
- Centre for Sport, Exercise and Life Sciences (CSELS), Faculty of Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Martin Lochner
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012, Bern, Switzerland
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
| | - Bruno G Frenguelli
- School of Life Sciences, University of Warwick, Gibbet Hill Rd, Coventry, CV4 7AL, UK.
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Ramírez-García PD, Retamal JS, Shenoy P, Imlach W, Sykes M, Truong N, Constandil L, Pelissier T, Nowell CJ, Khor SY, Layani LM, Lumb C, Poole DP, Lieu T, Stewart GD, Mai QN, Jensen DD, Latorre R, Scheff NN, Schmidt BL, Quinn JF, Whittaker MR, Veldhuis NA, Davis TP, Bunnett NW. A pH-responsive nanoparticle targets the neurokinin 1 receptor in endosomes to prevent chronic pain. Nat Nanotechnol 2019; 14:1150-1159. [PMID: 31686009 PMCID: PMC7765343 DOI: 10.1038/s41565-019-0568-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 10/02/2019] [Indexed: 05/11/2023]
Abstract
Nanoparticle-mediated drug delivery is especially useful for targets within endosomes because of the endosomal transport mechanisms of many nanomedicines within cells. Here, we report the design of a pH-responsive, soft polymeric nanoparticle for the targeting of acidified endosomes to precisely inhibit endosomal signalling events leading to chronic pain. In chronic pain, the substance P (SP) neurokinin 1 receptor (NK1R) redistributes from the plasma membrane to acidified endosomes, where it signals to maintain pain. Therefore, the NK1R in endosomes provides an important target for pain relief. The pH-responsive nanoparticles enter cells by clathrin- and dynamin-dependent endocytosis and accumulate in NK1R-containing endosomes. Following intrathecal injection into rodents, the nanoparticles, containing the FDA-approved NK1R antagonist aprepitant, inhibit SP-induced activation of spinal neurons and thus prevent pain transmission. Treatment with the nanoparticles leads to complete and persistent relief from nociceptive, inflammatory and neuropathic nociception and offers a much-needed non-opioid treatment option for chronic pain.
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Affiliation(s)
- Paulina D Ramírez-García
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Jeffri S Retamal
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Priyank Shenoy
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Wendy Imlach
- Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Matthew Sykes
- Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Nghia Truong
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Luis Constandil
- Laboratory of Neurobiology, Center for the Development of Nanoscience and Nanotechnology (CEDENNA), University of Santiago de Chile, Santiago, Chile
| | - Teresa Pelissier
- Laboratory of Neurobiology, Center for the Development of Nanoscience and Nanotechnology (CEDENNA), University of Santiago de Chile, Santiago, Chile
| | - Cameron J Nowell
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Song Y Khor
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Louis M Layani
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Chris Lumb
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Daniel P Poole
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - TinaMarie Lieu
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Gregory D Stewart
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Quynh N Mai
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Dane D Jensen
- Departments of Surgery and Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, Columbia University in the City of New York, New York , NY, USA
| | - Rocco Latorre
- Departments of Surgery and Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, Columbia University in the City of New York, New York , NY, USA
| | - Nicole N Scheff
- Bluestone Centre for Clinical Research, New York University College of Dentistry, New York, NY, USA
| | - Brian L Schmidt
- Bluestone Centre for Clinical Research, New York University College of Dentistry, New York, NY, USA
| | - John F Quinn
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Michael R Whittaker
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Nicholas A Veldhuis
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia.
| | - Thomas P Davis
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia.
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, Queensland, Australia.
| | - Nigel W Bunnett
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia.
- Departments of Surgery and Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, Columbia University in the City of New York, New York , NY, USA.
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia.
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Abstract
Expression of δ-opioid receptors in sensory neurons is controversial. In this issue of Neuron, Bardoni et al. (2014) present evidence that DOPrs are expressed on mechanosensory neurons involved in detecting nonnoxious touch but are very sparse in μ-opioid receptor-rich nociceptive neurons.
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Affiliation(s)
- Wendy Imlach
- Discipline of Pharmacology, The University of Sydney, Sydney, NSW 2006, Australia
| | - Macdonald J Christie
- Discipline of Pharmacology, The University of Sydney, Sydney, NSW 2006, Australia.
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Kottler B, Bao H, Zalucki O, Imlach W, Troup M, van Alphen B, Paulk A, Zhang B, van Swinderen B. A sleep/wake circuit controls isoflurane sensitivity in Drosophila. Curr Biol 2013; 23:594-8. [PMID: 23499534 DOI: 10.1016/j.cub.2013.02.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 01/07/2013] [Accepted: 02/08/2013] [Indexed: 10/27/2022]
Abstract
General anesthesia remains a mysterious phenomenon, even though a number of compelling target proteins and processes have been proposed [1]. General anesthetics such as isoflurane abolish behavioral responsiveness in all animals, and in the mammalian brain, these diverse compounds probably achieve this in part by targeting endogenous sleep mechanisms [2, 3]. However, most animals sleep [4], and they are therefore likely to have conserved sleep processes. A decade of neurogenetic studies of arousal in Drosophila melanogaster have identified a number of different neurons and brain structures that modulate sleep duration in the fly brain [5-9], but it has remained unclear until recently whether any neurons might form part of a dedicated circuit that actively controls sleep and wake states in the fly brain, as has been proposed for the mammalian brain [10]. We studied general anesthesia in Drosophila by measuring stimulus-induced locomotion under isoflurane gas exposure. Using a syntaxin1A gain-of-function construct, we found that increasing synaptic activity in different Drosophila neurons could produce hypersensitivity or resistance to isoflurane. We uncover a common pathway in the fly brain controlling both sleep duration and isoflurane sensitivity, centered on monoaminergic modulation of sleep-promoting neurons of the fan-shaped body.
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Affiliation(s)
- Benjamin Kottler
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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6
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Lloyd TE, Machamer J, O'Hara K, Kim JH, Collins SE, Wong MY, Sahin B, Imlach W, Yang Y, Levitan ES, McCabe BD, Kolodkin AL. The p150(Glued) CAP-Gly domain regulates initiation of retrograde transport at synaptic termini. Neuron 2012; 74:344-60. [PMID: 22542187 DOI: 10.1016/j.neuron.2012.02.026] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2012] [Indexed: 12/15/2022]
Abstract
p150(Glued) is the major subunit of dynactin, a complex that functions with dynein in minus-end-directed microtubule transport. Mutations within the p150(Glued) CAP-Gly microtubule-binding domain cause neurodegenerative diseases through an unclear mechanism. A p150(Glued) motor neuron degenerative disease-associated mutation introduced into the Drosophila Glued locus generates a partial loss-of-function allele (Gl(G38S)) with impaired neurotransmitter release and adult-onset locomotor dysfunction. Disruption of the p150(Glued) CAP-Gly domain in neurons causes a specific disruption of vesicle trafficking at terminal boutons (TBs), the distal-most ends of synapses. Gl(G38S) larvae accumulate endosomes along with dynein and kinesin motor proteins within swollen TBs, and genetic analyses show that kinesin and p150(Glued) function cooperatively at TBs to coordinate transport. Therefore, the p150(Glued) CAP-Gly domain regulates dynein-mediated retrograde transport at synaptic termini, and this function of dynactin is disrupted by a mutation that causes motor neuron disease.
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Affiliation(s)
- Thomas E Lloyd
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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7
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Abstract
In this video, we describe the electrophysiological methods for recording synaptic transmission at the neuromuscular junction (NMJ) of Drosophila larva. The larval neuromuscular system is a model synapse for the study of synaptic physiology and neurotransmission, and is a valuable research tool that has defined genetics and is accessible to experimental manipulation. Larvae can be dissected to expose the body wall musculature, central nervous system, and peripheral nerves. The muscles of Drosophila and their innervation pattern are well characterized and muscles are easy to access for intracellular recording. Individual muscles can be identified by their location and orientation within the 8 abdominal segments, each with 30 muscles arranged in a pattern that is repeated in segments A2 - A7. Dissected drosophila larvae are thin and individual muscles and bundles of motor neuron axons can be visualized by transillumination(1). Transgenic constructs can be used to label target cells for visual identification or for manipulating gene products in specific tissues. In larvae, excitatory junction potentials (EJP's) are generated in response to vesicular release of glutamate from the motoneurons at the synapse. In dissected larvae, the EJP can be recorded in the muscle with an intracellular electrode. Action potentials can be artificially evoked in motor neurons that have been cut posterior to the ventral ganglion, drawn into a glass pipette by gentle suction and stimulated with an electrode. These motor neurons have distinct firing thresholds when stimulated, and when they fire simultaneously, they generate a response in the muscle. Signals transmitted across the NMJ synapse can be recorded in the muscles that the motor neurons innervate. The EJP's and minature excitatory junction potentials (mEJP's) are seen as changes in membrane potential. Electrophysiological responses are recorded at room temperature in modified minimal hemolymph-like solution(2) (HL3) that contains 5 mM Mg(2+) and 1.5 mM Ca(2+). Changes in the amplitude of evoked EJP's can indicate differences in synaptic function and structure. Digitized recordings are analyzed for EJP amplitude, mEJP frequency and amplitude, and quantal content.
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Affiliation(s)
- Wendy Imlach
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, USA.
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Haig DM, Thomson J, McInnes CJ, Deane DL, Anderson IE, McCaughan CA, Imlach W, Mercer AA, Howard CJ, Fleming SB. A comparison of the anti-inflammatory and immuno-stimulatory activities of orf virus and ovine interleukin-10. Virus Res 2002; 90:303-16. [PMID: 12457984 DOI: 10.1016/s0168-1702(02)00252-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Orf virus causes pustular skin lesions (orf) in sheep, goats and humans. The virus encodes an interleukin-10 (orfvIL-10) that is identical in amino acid composition to ovine IL-10 (ovIL-10) over the C terminal two-thirds of the polypeptide, but not in the N terminal third. The immuno-suppressive and immuno-stimulatory activities of orfvIL-10 and ovIL-10 were compared. Both orfvIL-10 and ovIL-10 inhibited TNF-alpha and IL-8 cytokine production from stimulated ovine macrophages and keratinocytes and IFN-gamma and GM-CSF production from peripheral blood lymphocytes. OrfvIL-10 and ovIL-10 co-stimulated both ovine and murine mast cell proliferation in conjunction with IL-3 (ovine) or IL-4 (murine). Isoleucine at position 87 (Ile(87)) of the mature human IL-10 (huIL-10) has been reported as essential for the immuno-stimulatory activity of huIL-10. In spite of the differences in amino acids within the N-terminal third of orfvIL-10 compared with ovIL-10 and substitution of Ile(87) with Ala(87) in ovIL-10, these variants of ovIL-10 and orfvIL-10 all co-stimulated mast cell proliferation and inhibited macrophage IL-8 production. As ovIL-10 and orfvIL-10 have a similar structure to huIL-10 and conserved receptor-binding residues, it was concluded that Ile(87) is not essential for IL-10 immuno-stimulatory activity. Finally, ovine keratinocytes do not express ovIL-10. This might explain why orf virus has evolved a viral IL-10.
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Affiliation(s)
- David M Haig
- The Moredun Research Institute, International Research Center, Pentlands Science Park, Bush Loan, EH26 0PZ, Penicuik,
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9
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Abstract
Orf virus encodes a range of immuno-modulatory genes that interfere with host anti-virus immune and inflammatory effector mechanisms. The function of these reflects the pathogenesis of orf. The orf virus interferon resistance protein (OVIFNR) and virus IL-10 (vIL-10) inhibit interferon production and activity. In addition the vIL-10 suppresses inflammatory cytokine production by activated macrophages and keratinocytes. The virus GM-CSF inhibitory factor (GIF) is a novel virus protein that binds to and inhibits the biological activity of GM-CSF and IL-2. Together, these immuno-modulators target key effector mechanisms of host anti-virus immunity to allow time for virus replication in epidermal cells.
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Affiliation(s)
- David M Haig
- Moredun Research Institute, Pentlands Science Park, Penicuik EH26 0PZ, UK.
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10
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Imlach W, McCaughan CA, Mercer AA, Haig D, Fleming SB. Orf virus-encoded interleukin-10 stimulates the proliferation of murine mast cells and inhibits cytokine synthesis in murine peritoneal macrophages. J Gen Virol 2002; 83:1049-1058. [PMID: 11961259 DOI: 10.1099/0022-1317-83-5-1049] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Orf virus (ORFV) is the type species of the parapoxvirus genus and produces cutaneous pustular lesions in sheep, goats and humans. The genome encodes a polypeptide with remarkable homology to interleukin-10 (IL-10), particularly ovine IL-10, and also to IL-10-like proteins encoded by Epstein-Barr virus (EBV) and equine herpesvirus. IL-10 is a pleiotropic cytokine that can exert either immunostimulatory or immunosuppressive effects on many cell types. We have expressed and purified C-terminal FLAG and His(6)-tagged versions of ORFV-IL-10 and shown that ORFV-IL-10 costimulates murine mast cells (MC/9) and inhibits tumour necrosis factor-alpha synthesis in activated mouse peritoneal macrophages. Our results demonstrate that although ORFV-IL-10 is structurally similar to EBV-IL-10 it has evolved a different spectrum of activities. EBV-IL-10 does not stimulate the proliferation of thymocytes or mast cells whereas ORFV-IL-10 has both of these activities. Recent studies show that the critical difference in molecular structure of human IL-10 and EBV-IL-10, which may be the basis of their functional differences, is linked to a single amino acid substitution. Consistent with the activity spectrum reported here for ORFV-IL-10, the viral gene encodes the critical amino acid seen in human IL-10. Although the ORFV-IL-10 gene has clearly undergone significant evolutionary change at the nucleotide level compared with ovine IL-10, it has largely retained the polypeptide structure and functional characteristics of its ovine counterpart, suggesting that mutations of the gene to a potentially more potent immunosuppressive form may compromise the co-existence of host and virus.
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Affiliation(s)
- Wendy Imlach
- Virus Research Unit and Centre for Gene Research, Department of Microbiology, University of Otago, PO Box 56, Dunedin, New Zealand1
| | - Catherine A McCaughan
- Virus Research Unit and Centre for Gene Research, Department of Microbiology, University of Otago, PO Box 56, Dunedin, New Zealand1
| | - Andrew A Mercer
- Virus Research Unit and Centre for Gene Research, Department of Microbiology, University of Otago, PO Box 56, Dunedin, New Zealand1
| | - David Haig
- The Moredun Research Institute, International Research Centre, Pentland Science Park, Penicuik EH26 OPZ, UK2
| | - Stephen B Fleming
- Virus Research Unit and Centre for Gene Research, Department of Microbiology, University of Otago, PO Box 56, Dunedin, New Zealand1
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