1
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Schmacke NA, O'Duill F, Gaidt MM, Szymanska I, Kamper JM, Schmid-Burgk JL, Mädler SC, Mackens-Kiani T, Kozaki T, Chauhan D, Nagl D, Stafford CA, Harz H, Fröhlich AL, Pinci F, Ginhoux F, Beckmann R, Mann M, Leonhardt H, Hornung V. IKKβ primes inflammasome formation by recruiting NLRP3 to the trans-Golgi network. Immunity 2022; 55:2271-2284.e7. [PMID: 36384135 PMCID: PMC7614333 DOI: 10.1016/j.immuni.2022.10.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [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: 02/14/2022] [Revised: 07/17/2022] [Accepted: 10/26/2022] [Indexed: 11/17/2022]
Abstract
The NLRP3 inflammasome plays a central role in antimicrobial defense as well as in the context of sterile inflammatory conditions. NLRP3 activity is governed by two independent signals: the first signal primes NLRP3, rendering it responsive to the second signal, which then triggers inflammasome formation. Our understanding of how NLRP3 priming contributes to inflammasome activation remains limited. Here, we show that IKKβ, a kinase activated during priming, induces recruitment of NLRP3 to phosphatidylinositol-4-phosphate (PI4P), a phospholipid enriched on the trans-Golgi network. NEK7, a mitotic spindle kinase that had previously been thought to be indispensable for NLRP3 activation, was redundant for inflammasome formation when IKKβ recruited NLRP3 to PI4P. Studying iPSC-derived human macrophages revealed that the IKKβ-mediated NEK7-independent pathway constitutes the predominant NLRP3 priming mechanism in human myeloid cells. Our results suggest that PI4P binding represents a primed state into which NLRP3 is brought by IKKβ activity.
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Affiliation(s)
- Niklas A Schmacke
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Fionan O'Duill
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Moritz M Gaidt
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Inga Szymanska
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Julia M Kamper
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Jonathan L Schmid-Burgk
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Sophia C Mädler
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Timur Mackens-Kiani
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Tatsuya Kozaki
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A∗STAR), 8A Biomedical Grove, Immunos Building #3-4, Biopolis, Singapore 138648, Singapore
| | - Dhruv Chauhan
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Dennis Nagl
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Che A Stafford
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Hartmann Harz
- Faculty of Biology, Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Adrian L Fröhlich
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Francesca Pinci
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A∗STAR), 8A Biomedical Grove, Immunos Building #3-4, Biopolis, Singapore 138648, Singapore; Shanghai Institute of Immunology, Shanghai JiaoTong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China; Translational Immunology Institute, SingHealth Duke-NUS Academic Medical Centre, Singapore 169856, Singapore
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Heinrich Leonhardt
- Faculty of Biology, Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany.
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2
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Liu Z, Dagley LF, Shield-Artin K, Young SN, Bankovacki A, Wang X, Tang M, Howitt J, Stafford CA, Nachbur U, Fitzgibbon C, Garnish SE, Webb AI, Komander D, Murphy JM, Hildebrand JM, Silke J. Oligomerization-driven MLKL ubiquitylation antagonizes necroptosis. EMBO J 2021; 40:e103718. [PMID: 34698396 DOI: 10.15252/embj.2019103718] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [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: 10/14/2019] [Revised: 09/02/2021] [Accepted: 09/20/2021] [Indexed: 11/09/2022] Open
Abstract
Mixed lineage kinase domain-like (MLKL) is the executioner in the caspase-independent form of programmed cell death called necroptosis. Receptor-interacting serine/threonine protein kinase 3 (RIPK3) phosphorylates MLKL, triggering MLKL oligomerization, membrane translocation and membrane disruption. MLKL also undergoes ubiquitylation during necroptosis, yet neither the mechanism nor the significance of this event has been demonstrated. Here, we show that necroptosis-specific multi-mono-ubiquitylation of MLKL occurs following its activation and oligomerization. Ubiquitylated MLKL accumulates in a digitonin-insoluble cell fraction comprising organellar and plasma membranes and protein aggregates. Appearance of this ubiquitylated MLKL form can be reduced by expression of a plasma membrane-located deubiquitylating enzyme. Oligomerization-induced MLKL ubiquitylation occurs on at least four separate lysine residues and correlates with its proteasome- and lysosome-dependent turnover. Using a MLKL-DUB fusion strategy, we show that constitutive removal of ubiquitin from MLKL licences MLKL auto-activation independent of necroptosis signalling in mouse and human cells. Therefore, in addition to the role of ubiquitylation in the kinetic regulation of MLKL-induced death following an exogenous necroptotic stimulus, it also contributes to restraining basal levels of activated MLKL to avoid unwanted cell death.
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Affiliation(s)
- Zikou Liu
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Kristy Shield-Artin
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Samuel N Young
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Aleksandra Bankovacki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Translational Research, CSL Limited, Melbourne, VIC, Australia
| | - Xiangyi Wang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Michelle Tang
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Jason Howitt
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Che A Stafford
- Gene Centre and Department of Biochemistry, Ludwig Maximilian University of Munich, Munich, Germany
| | - Ueli Nachbur
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Cheree Fitzgibbon
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Sarah E Garnish
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - David Komander
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Joanne M Hildebrand
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - John Silke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
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3
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Heim VJ, Dagley LF, Stafford CA, Hansen FM, Clayer E, Bankovacki A, Webb AI, Lucet IS, Silke J, Nachbur U. A regulatory region on RIPK2 is required for XIAP binding and NOD signaling activity. EMBO Rep 2020; 21:e50400. [PMID: 32954645 DOI: 10.15252/embr.202050400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 03/11/2020] [Revised: 07/30/2020] [Accepted: 08/13/2020] [Indexed: 01/01/2023] Open
Abstract
Signaling via the intracellular pathogen receptors nucleotide-binding oligomerization domain-containing proteins NOD1 and NOD2 requires receptor interacting kinase 2 (RIPK2), an adaptor kinase that can be targeted for the treatment of various inflammatory diseases. However, the molecular mechanisms of how RIPK2 contributes to NOD signaling are not completely understood. We generated FLAG-tagged RIPK2 knock-in mice using CRISPR/Cas9 technology to study NOD signaling mechanisms at the endogenous level. Using cells from these mice, we were able to generate a detailed map of post-translational modifications on RIPK2. Similar to other reports, we did not detect ubiquitination of RIPK2 lysine 209 during NOD2 signaling. However, using site-directed mutagenesis we identified a new regulatory region on RIPK2, which dictates the crucial interaction with the E3 ligase XIAP and downstream signaling outcomes.
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Affiliation(s)
- Valentin J Heim
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Che A Stafford
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Fynn M Hansen
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Elise Clayer
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Aleksandra Bankovacki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Isabelle S Lucet
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - John Silke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Ueli Nachbur
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
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4
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Michalski S, de Oliveira Mann CC, Stafford CA, Witte G, Bartho J, Lammens K, Hornung V, Hopfner KP. Structural basis for sequestration and autoinhibition of cGAS by chromatin. Nature 2020; 587:678-682. [PMID: 32911480 DOI: 10.1038/s41586-020-2748-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/24/2020] [Indexed: 01/14/2023]
Abstract
Cyclic GMP-AMP synthase (cGAS) is an innate immune sensor for cytosolic microbial DNA1. After binding DNA, cGAS synthesizes the messenger 2'3'-cyclic GMP-AMP (cGAMP)2-4, which triggers cell-autonomous defence and the production of type I interferons and pro-inflammatory cytokines via the activation of STING5. In addition to responding to cytosolic microbial DNA, cGAS also recognizes mislocalized cytosolic self-DNA and has been implicated in autoimmunity and sterile inflammation6,7. Specificity towards pathogen- or damage-associated DNA was thought to be caused by cytosolic confinement. However, recent findings place cGAS robustly in the nucleus8-10, where tight tethering of chromatin is important to prevent autoreactivity to self-DNA8. Here we show how cGAS is sequestered and inhibited by chromatin. We provide a cryo-electron microscopy structure of the cGAS catalytic domain bound to a nucleosome, which shows that cGAS does not interact with the nucleosomal DNA, but instead interacts with histone 2A-histone 2B, and is tightly anchored to the 'acidic patch'. The interaction buries the cGAS DNA-binding site B, and blocks the formation of active cGAS dimers. The acidic patch robustly outcompetes agonistic DNA for binding to cGAS, which suggests that nucleosome sequestration can efficiently inhibit cGAS, even when accessible DNA is nearby, such as in actively transcribed genomic regions. Our results show how nuclear cGAS is sequestered by chromatin and provides a mechanism for preventing autoreactivity to nuclear self-DNA.
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Affiliation(s)
- Sebastian Michalski
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Carina C de Oliveira Mann
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Che A Stafford
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Gregor Witte
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Joseph Bartho
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Katja Lammens
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Veit Hornung
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Karl-Peter Hopfner
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany. .,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany.
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5
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Tanzer MC, Frauenstein A, Stafford CA, Phulphagar K, Mann M, Meissner F. Quantitative and Dynamic Catalogs of Proteins Released during Apoptotic and Necroptotic Cell Death. Cell Rep 2020; 30:1260-1270.e5. [DOI: 10.1016/j.celrep.2019.12.079] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 11/07/2019] [Accepted: 12/19/2019] [Indexed: 12/16/2022] Open
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6
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Abstract
Innate immune signaling and programmed cell death are intimately linked, and many signaling pathways can regulate and induce both, transcription of inflammatory mediators or autonomous cell death. The best-characterized examples for these dual outcomes are members of the TNF superfamily, the inflammasome receptors, and the toll-like receptors. Signaling via the intracellular peptidoglycan receptors NOD1 and NOD2, however, does not appear to follow this trend, despite involving signaling proteins, or proteins with domains that are linked to programmed cell death, such as RIP kinases, inhibitors of apoptosis (IAP) proteins or the CARD domains on NOD1/2. To better understand the connections between NOD signaling and cell death induction, we here review the latest findings on the molecular regulation of signaling downstream of the NOD receptors and explore the links between this immune signaling pathway and the regulation of cell death.
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Affiliation(s)
- Valentin J Heim
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Che A Stafford
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Ueli Nachbur
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
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7
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Bernardini JP, Brouwer JM, Tan IK, Sandow JJ, Huang S, Stafford CA, Bankovacki A, Riffkin CD, Wardak AZ, Czabotar PE, Lazarou M, Dewson G. Parkin inhibits BAK and BAX apoptotic function by distinct mechanisms during mitophagy. EMBO J 2018; 38:embj.201899916. [PMID: 30573668 DOI: 10.15252/embj.201899916] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [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: 06/01/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 12/26/2022] Open
Abstract
The E3 ubiquitin ligase Parkin is a key effector of the removal of damaged mitochondria by mitophagy. Parkin determines cell fate in response to mitochondrial damage, with its loss promoting early onset Parkinson's disease and potentially also cancer progression. Controlling a cell's apoptotic response is essential to co-ordinate the removal of damaged mitochondria. We report that following mitochondrial damage-induced mitophagy, Parkin directly ubiquitinates the apoptotic effector protein BAK at a conserved lysine in its hydrophobic groove, a region that is crucial for BAK activation by BH3-only proteins and its homo-dimerisation during apoptosis. Ubiquitination inhibited BAK activity by impairing its activation and the formation of lethal BAK oligomers. Parkin also suppresses BAX-mediated apoptosis, but in the absence of BAX ubiquitination suggesting an indirect mechanism. In addition, we find that BAK-dependent mitochondrial outer membrane permeabilisation during apoptosis promotes PINK1-dependent Parkin activation. Hence, we propose that Parkin directly inhibits BAK to suppress errant apoptosis, thereby allowing the effective clearance of damaged mitochondria, but also promotes clearance of apoptotic mitochondria to limit their potential pro-inflammatory effect.
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Affiliation(s)
- Jonathan P Bernardini
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Iris Kl Tan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Jarrod J Sandow
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Shuai Huang
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Che A Stafford
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Aleksandra Bankovacki
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Christopher D Riffkin
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Michael Lazarou
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute Monash University, Clayton, Melbourne, Vic., Australia
| | - Grant Dewson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia .,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
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8
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Stafford CA, Lawlor KE, Heim VJ, Bankovacki A, Bernardini JP, Silke J, Nachbur U. IAPs Regulate Distinct Innate Immune Pathways to Co-ordinate the Response to Bacterial Peptidoglycans. Cell Rep 2018; 22:1496-1508. [DOI: 10.1016/j.celrep.2018.01.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/02/2017] [Accepted: 01/08/2018] [Indexed: 12/19/2022] Open
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9
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Stafford CA, Nachbur U. A NODding acquaintance with ER stress. Cell Death Discov 2016; 2:16037. [PMID: 27551527 PMCID: PMC4979412 DOI: 10.1038/cddiscovery.2016.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- C A Stafford
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - U Nachbur
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
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10
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Nachbur U, Stafford CA, Bankovacki A, Zhan Y, Lindqvist LM, Fiil BK, Khakham Y, Ko HJ, Sandow JJ, Falk H, Holien JK, Chau D, Hildebrand J, Vince JE, Sharp PP, Webb AI, Jackman KA, Mühlen S, Kennedy CL, Lowes KN, Murphy JM, Gyrd-Hansen M, Parker MW, Hartland EL, Lew AM, Huang DCS, Lessene G, Silke J. A RIPK2 inhibitor delays NOD signalling events yet prevents inflammatory cytokine production. Nat Commun 2015; 6:6442. [PMID: 25778803 DOI: 10.1038/ncomms7442] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/29/2015] [Indexed: 12/22/2022] Open
Abstract
Intracellular nucleotide binding and oligomerization domain (NOD) receptors recognize antigens including bacterial peptidoglycans and initiate immune responses by triggering the production of pro-inflammatory cytokines through activating NF-κB and MAP kinases. Receptor interacting protein kinase 2 (RIPK2) is critical for NOD-mediated NF-κB activation and cytokine production. Here we develop and characterize a selective RIPK2 kinase inhibitor, WEHI-345, which delays RIPK2 ubiquitylation and NF-κB activation downstream of NOD engagement. Despite only delaying NF-κB activation on NOD stimulation, WEHI-345 prevents cytokine production in vitro and in vivo and ameliorates experimental autoimmune encephalomyelitis in mice. Our study highlights the importance of the kinase activity of RIPK2 for proper immune responses and demonstrates the therapeutic potential of inhibiting RIPK2 in NOD-driven inflammatory diseases.
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Affiliation(s)
- Ueli Nachbur
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Che A Stafford
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Aleksandra Bankovacki
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Yifan Zhan
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Lisa M Lindqvist
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Berthe K Fiil
- 1] Department of Disease Biology, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark [2] Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Yelena Khakham
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hyun-Ja Ko
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jarrod J Sandow
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hendrik Falk
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia [3] Cancer Therapeutics CRC, Bundoora, Victoria 3083, Australia
| | - Jessica K Holien
- ACRF Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia
| | - Diep Chau
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Joanne Hildebrand
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - James E Vince
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Phillip P Sharp
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew I Webb
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Katherine A Jackman
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, Austin Campus, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia
| | - Sabrina Mühlen
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Catherine L Kennedy
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Kym N Lowes
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - James M Murphy
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Mads Gyrd-Hansen
- 1] Department of Disease Biology, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark [2] Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Michael W Parker
- 1] ACRF Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia [2] Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Andrew M Lew
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - David C S Huang
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Guillaume Lessene
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - John Silke
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
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11
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Abstract
An exact expression for the heat current in an interacting nanostructure is derived and used to calculate the thermoelectric response of three representative single-molecule junctions formed from isoprene, 1,3-benzenedithiol, and [18]-annulene. Dramatic enhancements of the thermopower S and Lorenz number L are predicted when the junction is tuned across a node in the transmission function, with universal maximum values S(max) = (pi/3(1/2))(k(B)/e) and L(max) = (7pi(2)/5)(k(B)(2)/e(2)). The effect of a finite minimum transmission probability due, e.g., to incoherent processes or additional nonresonant channels, is also considered.
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Affiliation(s)
- J P Bergfield
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
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12
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Bürki J, Stafford CA, Stein DL. Order of phase transitions in barrier crossing. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 77:061115. [PMID: 18643225 DOI: 10.1103/physreve.77.061115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Indexed: 05/26/2023]
Abstract
A spatially extended classical system with metastable states subject to weak spatiotemporal noise can exhibit a transition in its activation behavior when one or more external parameters are varied. Depending on the potential, the transition can be first or second order, but there exists no systematic theory of the relation between the order of the transition and the shape of the potential barrier. In this paper, we address that question in detail for a general class of systems whose order parameter is describable by a classical field that can vary in both space and time, and whose zero-noise dynamics are governed by a smooth polynomial potential. We show that a quartic potential barrier can have only second-order transitions, confirming an earlier conjecture [D. L. Stein, J. Stat. Phys. 114, 1537 (2004)]. We then derive, through a combination of analytical and numerical arguments, both necessary and sufficient conditions to have a first-order vs a second-order transition in noise-induced activation behavior, for a large class of systems with smooth polynomial potentials of arbitrary order. We find in particular that the order of the transition is especially sensitive to the potential behavior near the top of the barrier.
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Affiliation(s)
- J Bürki
- Physics Department, University of Arizona, Tucson, Arizona 85721, USA
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13
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Mares AI, Urban DF, Bürki J, Grabert H, Stafford CA, van Ruitenbeek JM. Electronic and atomic shell structure in aluminium nanowires. Nanotechnology 2007; 18:265403. [PMID: 21730404 DOI: 10.1088/0957-4484/18/26/265403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report experiments on aluminium nanowires in ultra-high vacuum at room temperature that reveal a periodic spectrum of exceptionally stable structures. Two 'magic' series of stable structures are observed: at low conductance, the formation of stable nanowires is governed by electronic shell effects whereas for larger contacts atomic packing dominates. The crossover between the two regimes is found to be smooth. A detailed comparison of the experimental results to a theoretical stability analysis indicates that, while the main features of the observed electron-shell structure are similar to those of alkali and noble metals, a sequence of extremely stable wires plays a unique role in aluminium. This series appears isolated in conductance histograms and can be attributed to 'superdeformed' non-axisymmetric nanowires.
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Affiliation(s)
- A I Mares
- Kamerlingh Onnes Laboratorium, Universiteit Leiden, PO Box 9504, 2300 RA Leiden, The Netherlands
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14
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Dietz B, Friedrich T, Metz J, Miski-Oglu M, Richter A, Schäfer F, Stafford CA. Rabi oscillations at exceptional points in microwave billiards. Phys Rev E Stat Nonlin Soft Matter Phys 2007; 75:027201. [PMID: 17358455 DOI: 10.1103/physreve.75.027201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Indexed: 05/14/2023]
Abstract
We experimentally investigated the decay behavior with time t of resonances near and at exceptional points, where two complex eigenvalues and also the associated eigenfunctions coalesce. The measurements were performed with a dissipative microwave billiard, whose shape depends on two parameters. The t2 dependence predicted at the exceptional point on the basis of a two-state matrix model could be verified. Outside the exceptional point the predicted Rabi oscillations, also called quantum echoes in this context, were detected.
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Affiliation(s)
- B Dietz
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
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15
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Abstract
Thermally induced conductance jumps of metal nanowires are modeled using stochastic Ginzburg-Landau field theories. Changes in radius are predicted to occur via the nucleation of surface kinks at the wire ends, consistent with recent electron microscopy studies. The activation rate displays nontrivial dependence on nanowire length, and undergoes first- or second-order-like transitions as a function of length. The activation barriers of the most stable structures are predicted to be universal, i.e., independent of the radius of the wire, and proportional to the square root of the surface tension. The reduction of the activation barrier under strain is also determined.
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Affiliation(s)
- J Bürki
- Department of Physics, University of Arizona, 1118 East Fourth Street, Tucson, AZ 85721, USA
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16
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Urban DF, Bürki J, Zhang CH, Stafford CA, Grabert H. Jahn-Teller distortions and the supershell effect in metal nanowires. Phys Rev Lett 2004; 93:186403. [PMID: 15525187 DOI: 10.1103/physrevlett.93.186403] [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] [Received: 12/19/2003] [Indexed: 05/24/2023]
Abstract
A stability analysis of metal nanowires shows that a Jahn-Teller deformation breaking cylindrical symmetry can be energetically favorable, leading to stable nanowires with elliptic cross sections. The sequence of stable cylindrical and elliptical nanowires allows for a consistent interpretation of experimental conductance histograms for alkali metals, including both the electronic shell and supershell structures. It is predicted that for gold, elliptical nanowires are even more likely to form since their eccentricity is smaller than for alkali metals. The existence of certain metastable superdeformed nanowires is also predicted.
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Affiliation(s)
- D F Urban
- Physikalisches Institut, Albert-Ludwigs-Universität, D-79104 Freiburg, Germany
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17
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Bürki J, Goldstein RE, Stafford CA. Quantum necking in stressed metallic nanowires. Phys Rev Lett 2003; 91:254501. [PMID: 14754119 DOI: 10.1103/physrevlett.91.254501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2002] [Revised: 07/14/2003] [Indexed: 05/24/2023]
Abstract
When a macroscopic metallic wire is subject to tensile stress, it necks down smoothly as it elongates. We show that nanowires with radii comparable to the Fermi wavelength display remarkably different behavior. Using concepts from fluid dynamics, a partial differential equation for nanowire shape evolution is derived from a semiclassical energy functional that includes electron-shell effects. A rich dynamics involving movement and interaction of kinks connecting locally stable radii is found, and a new class of universal equilibrium shapes is predicted.
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Affiliation(s)
- J Bürki
- Department of Physics, University of Arizona, Tucson, Arizona 85721, USA
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18
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Cardamone DM, Stafford CA, Barrett BR. How to measure the spreading width for the decay of superdeformed nuclei. Phys Rev Lett 2003; 91:102502. [PMID: 14525475 DOI: 10.1103/physrevlett.91.102502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2003] [Indexed: 05/24/2023]
Abstract
A new expression for the branching ratio for the decay via the E1 process in the normal-deformed band of superdeformed nuclei is given within a simple two-level model. Using this expression, the spreading or tunneling width gamma (downward arrow) for superdeformed decay can be expressed entirely in terms of experimentally known quantities. We show how to determine the tunneling matrix element V from the measured value of gamma (downward arrow) and a statistical model of the energy levels. The accuracy of the two-level approximation is verified by considering the effects of the other normal-deformed states.
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Affiliation(s)
- D M Cardamone
- Physics Department, P.O. Box 210081, University of Arizona, Tucson, Arizona 85721, USA
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19
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Eckle HP, Johannesson H, Stafford CA. Kondo resonance in a mesoscopic ring coupled to a quantum dot: exact results for the Aharonov-Bohm-Casher effects. Phys Rev Lett 2001; 87:016602. [PMID: 11461484 DOI: 10.1103/physrevlett.87.016602] [Citation(s) in RCA: 2] [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] [Received: 10/05/2000] [Indexed: 05/23/2023]
Abstract
We study the persistent currents induced by both the Aharonov-Bohm and Aharonov-Casher effects in a one-dimensional mesoscopic ring coupled to a sidebranch quantum dot at Kondo resonance. For privileged values of the Aharonov-Bohm-Casher fluxes, the problem can be mapped onto an integrable model, exactly solvable by a Bethe ansatz. In the case of a pure magnetic Aharonov-Bohm flux, we find that the presence of the quantum dot has no effect on the persistent current. In contrast, the Kondo resonance interferes with the spin-dependent Aharonov-Casher effect to induce a current which, in the strong-coupling limit, is independent of the number of electrons in the ring.
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Affiliation(s)
- H P Eckle
- School of Physics, The University of New South Wales, Sydney, 2052, Australia
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20
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Stafford CA, Burki J, Baeriswyl D. Comment on "Density functional simulation of a breaking nanowire". Phys Rev Lett 2000; 84:2548. [PMID: 11018936 DOI: 10.1103/physrevlett.84.2548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/1999] [Indexed: 05/23/2023]
Affiliation(s)
- CA Stafford
- University of Arizona, Tucson, Arizona 85721 and Universite de Fribourg, 1700 Fribourg, Switzerland
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21
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Nona SN, Thomlinson AM, Stafford CA. Temporary colonization of the site of lesion by macrophages is a prelude to the arrival of regenerated axons in injured goldfish optic nerve. J Neurocytol 1998; 27:791-803. [PMID: 10451426 DOI: 10.1023/a:1006951314031] [Citation(s) in RCA: 12] [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] [Indexed: 11/12/2022]
Abstract
In crushed goldfish optic nerve, regenerating axons cross the site of lesion within 10 days following injury. Some 30 days later, Schwann cells accumulate at the lesion, where they myelinate the new axons. In this study, we have used immunohistochemistry and electron microscopy to examine the cellular environment of the crush site prior to the establishment of Schwann cells in order to learn more about the early events that contribute to axonal regeneration. During the first week following injury, macrophages enter the site of lesion and efficiently phagocytose the debris. The infiltration of macrophages precedes the arrival of regenerating axons that abut and surround these phagocytes. Based on EM morphology and phagocytic capacity, macrophages of the type observed at the site of lesion are not present in the degenerating distal nerve segment, where debris clearance is shared between conventional microglia and astrocytes over a period of several weeks. During this period, axon bundles emerging distally from the injury zone become enwrapped by astrocyte processes, thereby re-establishing the characteristic fascicular cytoarchitecture of the optic nerve. The process of fasciculation also leads to the displacement of myelin debris to the margins of the fiber bundles, where it is trapped by the astrocytes. Our results suggest that the early robust appearance of macrophages at the lesion, and their effectiveness as phagocytes compared with the microglia distally, may contribute to the vigorous axonal regeneration across the crush, beyond which axons--excepting the pioneers--extend through newly formed debris-free channels delineated by astrocyte processes.
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Affiliation(s)
- S N Nona
- Neuroscience Group, Department of Optometry & Vision Sciences, UMIST, Manchester M60 1QD, UK
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23
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Stafford CA, Wingreen NS. Resonant photon-assisted tunneling through a double quantum dot: An electron pump from spatial Rabi oscillations. Phys Rev Lett 1996; 76:1916-1919. [PMID: 10060553 DOI: 10.1103/physrevlett.76.1916] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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25
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Nona SN, Stafford CA. Glial repair at the lesion site in regenerating goldfish spinal cord: an immunohistochemical study using species-specific antibodies. J Neurosci Res 1995; 42:350-6. [PMID: 8583503 DOI: 10.1002/jnr.490420309] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have used fish-specific antibodies to show that repair in regenerating goldfish spinal cord is accompanied by the recovery of the astrocytic environment and restoration of the central canal. Astrocyte processes trailed the regenerated axons bridging the new cord, suggesting that they are not needed for axonal regrowth.
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Affiliation(s)
- S N Nona
- Department of Optometry and Vision Sciences, University of Manchester Institute of Science and Technology, UK
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26
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Liu DZ, Hu BY, Stafford CA. Dynamic magnetoconductance fluctuations and oscillations in mesoscopic wires and rings. Phys Rev B Condens Matter 1994; 50:5799-5802. [PMID: 9976943 DOI: 10.1103/physrevb.50.5799] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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27
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Nona SN, Stafford CA, Duncan A, Cronly-Dillon JR, Scholes J. Myelin repair by Schwann cells in the regenerating goldfish visual pathway: regional patterns revealed by X-irradiation. J Neurocytol 1994; 23:400-9. [PMID: 7964909 DOI: 10.1007/bf01207112] [Citation(s) in RCA: 14] [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] [Indexed: 01/28/2023]
Abstract
In the regenerating goldfish optic nerves, Schwann cells of unknown origin reliably infiltrate the lesion site forming a band of peripheral-type myelinating tissue by 1-2 months, sharply demarcated from the adjacent new CNS myelin. To investigate this effect, we have interfered with cell proliferation by locally X-irradiating the fish visual pathway 24h after the lesion. As assayed by immunohistochemistry and EM, irradiation retards until 6 months formation of new myelin by Schwann cells at the lesion site, and virtually abolishes oligodendrocyte myelination distally, but has little or no effect on nerve fibre regrowth. Optic nerve astrocyte processes normally fail to re-infiltrate the lesion, but re-occupy it after irradiation, suggesting that they are normally excluded by early cell proliferation at this site. Moreover, scattered myelinating Schwann cells also appear in the oligodendrocyte-depleted distal optic nerve after irradiation, although only as far as the optic tract. Optic nerve reticular astrocytes differ in various ways from radial glia elsewhere in the fish CNS, and our observations suggest that they may be more permissive to Schwann cell invasion of CNS tissue.
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Affiliation(s)
- S N Nona
- Department of Optometry and Vision Sciences, UMIST, Manchester, UK
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Stafford CA, Millis AJ. Scaling theory of the Mott-Hubbard metal-insulator transition in one dimension. Phys Rev B Condens Matter 1993; 48:1409-1425. [PMID: 10008501 DOI: 10.1103/physrevb.48.1409] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Nona SN, Duncan A, Stafford CA, Maggs A, Jeserich G, Cronly-Dillon JR. Myelination of regenerated axons in goldfish optic nerve by Schwann cells. J Neurocytol 1992; 21:391-401. [PMID: 1403004 DOI: 10.1007/bf01191504] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study uses immunohistochemistry and EM to examine the site of injury in goldfish optic nerve during axonal regeneration. Within seven days of nerve crush axons begin to regrow and a network of GFAP+ reactive astrocytes appears in the nerve on either side of the injury. However, the damaged area remains GFAP-. By 42 days after nerve crush, the sheaths of new axons acquire myelin marker 6D2, and the crush area becomes populated by a mass of longitudinally-orientated S-100+ cells. Ultrastructurally, the predominant cells in the crush area bear a strong resemblance to peripheral nerve Schwann cells; they display a one-to-one association with myelinated axons, have a basal lamina and are surrounded by collagen fibres. It is proposed that these cells are Schwann cells which enter the optic nerve as a result of crush, where they become confined to the astrocyte-free crush area.
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Affiliation(s)
- S N Nona
- Department of Optometry and Vision Sciences, UMIST, Manchester, UK
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Stafford CA, Millis AJ, Shastry BS. Finite-size effects on the optical conductivity of a half-filled Hubbard ring. Phys Rev B Condens Matter 1991; 43:13660-13663. [PMID: 9997211 DOI: 10.1103/physrevb.43.13660] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Shehab SA, Cronly-Dillon JR, Nona SN, Stafford CA. Preferential histochemical staining of protoplasmic and fibrous astrocytes in rat CNS with GFAP antibodies using different fixatives. Brain Res 1990; 518:347-52. [PMID: 2202491 DOI: 10.1016/0006-8993(90)90996-o] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Serial sections of rat brain and spinal cord were fixed in either acid-alcohol or 4% paraformaldehyde, and stained for visualization of astrocytes using GFAP antibodies. With paraformaldehyde, GFAP-positive astrocytes were visualised almost exclusively in the grey matter of all above tissues. In sharp contrast, acid-alcohol treatment gave intensely stained GFAP-containing astrocytes in the white matter. Since fibrous astrocytes are mainly located in the white matter and protoplasmic astrocytes are located in the grey matter, it is concluded that acid-alcohol is a good fixative for fibrous astrocytes while paraformaldehyde is a better fixative for protoplasmic astrocytes.
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Affiliation(s)
- S A Shehab
- Department of Optometry and Vision Sciences, UMIST, Manchester, U.K
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34
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Abstract
By using an antibody to goldfish glial fibrillary acidic protein (GFAP), the reaction of goldfish optic nerve to injury has been studied by immunoblotting and immunohistochemical methods. Goldfish optic nerve, which normally lacks GFAP immunoreactivity (Nona et al.: Glia, 2:189-200, 1989), expresses GFAP following injury. This immunoreactivity, which is observed as early as 10 days after crush and which is still evident at 30 days after crush, all but disappears by 150 days after crush. Since it is well established that functional restoration of synaptic connections and the recovery of vision takes place in goldfish following optic nerve injury, our results indicate that reactive astrocytes do not represent an impediment to regeneration in goldfish visual system.
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Affiliation(s)
- C A Stafford
- Department of Optometry and Vision Sciences, UMIST, Manchester, England
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35
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Abstract
A polyclonal antibody to goldfish GFAP recognises, immunohistochemically, astrocyte populations in rat brain, spinal cord and optic nerve. The pattern of staining compares favourably with that obtained using a polyclonal anti-human GFAP or a monoclonal anti-porcine GFAP. These results are consistent with the notion that GFAP is well conserved in vertebrate phylogeny.
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Affiliation(s)
- S S Shehab
- Department of Optometry and Vision Sciences, U.M.I.S.T., Manchester
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36
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Abstract
An intermediate filament fraction, isolated from goldfish brain, contains a prominent protein having a molecular weight of 51 kDa. In normal goldfish visual pathway, this protein is present in tectum and tract, but not in optic nerve. A polyclonal antibody raised to this protein clearly labels ependymal glial profiles in tectum and parallel processes in the tract, whereas optic nerve is unlabelled; Müller fibres in the retina are also labelled. A similar, but less prominent, pattern of staining is observed with antibodies, raised elsewhere, against glial fibrillary acidic protein from human and porcine. These results suggest that the 51 kDa protein is a GFAP, demonstrate the heterogeneity of astrocytes in goldfish visual pathway, and are consistent with the idea that GFAP is well conserved in vertebrate phylogeny.
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Affiliation(s)
- S N Nona
- Department of Optometry and Vision Sciences, University of Manchester Institute of Science & Technology, England
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Cronly-Dillon JR, Stafford CA. Goldfish retina and tectum influence each other's growth activity during regrowth of the retinotectal projection. Brain Res 1986; 395:13-23. [PMID: 3779429 DOI: 10.1016/s0006-8993(86)80003-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Variations in retinal and tectal growth activity, during regrowth of the goldfish retinotectal projection, were monitored by measuring the rates of incorporation of [14C]leucine into soluble protein and tubulin-enriched fractions at different times after crushing the optic nerves. Other experiments tested for growth-modulating interactions between tectum and retina. Here we studied how the absence of one of these structures (i.e. tectal ablation or eye removal) affected the profile of biosynthetic activity in the other. Experiments were also conducted on groups of fish in which the tectum was reinnervated by a half-retina (either half-nasal (1/2 N) or half-temporal (1/2 T) retina). This was done to ascertain if growth interactions between retina and tectum display any position-dependent differences that may be relevant to retinotopic ordering during regeneration. Our studies have revealed that: the retina and tectum of 1/2 T and 1/2 N groups differ in their growth responses during regeneration of the visual pathway: the tectum may exert a stimulatory and at other times an inhibitory influence on retinal protein synthesis; and retina and tectum display a bimodal profile of biosynthetic activity during regeneration that coincides with two stages of increased cell division (primarily glia) which other workers have found occurs in the tectum and tract during regeneration of the retinotectal projection. Indeed it seems there may be a link between this glial proliferation and the neurotrophic and guiding influences which tectum and retina exert upon one another during regeneration.
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Cook GM, Bellairs R, Rutherford NG, Stafford CA, Alderson T. Isolation, characterization and localization of a lectin within the vitelline membrane of the hen's egg. J Embryol Exp Morphol 1985; 90:389-407. [PMID: 2422312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A lectin with an affinity for certain sulphated polysaccharides, such as fucoidin and dextran sulphate, has been isolated from the vitelline membrane of hens' eggs and purified to homogeneity as assessed by two-dimensional gel electrophoresis. Polyclonal and monoclonal antibodies have been raised to the lectin and used in indirect immunofluorescence microscopy to localize the agglutinin in the outer layer of the vitelline membrane, where the lectin persists prior to the breakdown of the vitelline membrane. The quantity of lectin extracted from the two layers of the membrane, which have been separated by the method of Bellairs, Harkness & Harkness (1963), correlated well with the results of immunofluorescence microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the two layers of the membrane indicates that each layer has a distinctive polypeptide composition, the outer layer containing in particular lysozyme and avidin. The evidence obtained in this study indicates that the lectin is not involved in adhesion of the blastoderm to the vitelline membrane; neither is it involved in the expression of the blastoderm nor in maintaining the strength of the membrane. The possible roles in promoting transport of solutes across the membrane as well as providing bactericidal properties to the egg are discussed.
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Jones OW, Penn NE, Shuchter S, Stafford CA, Richards T, Kernahan C, Gutierrez J, Cherkin P, Reinsch S, Dixson B. Parental response to mid-trimester therapeutic abortion following amniocentesis. Prenat Diagn 1984; 4:249-56. [PMID: 6483786 DOI: 10.1002/pd.1970040403] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This article reports the results of a retrospective study designed to examine the responses of couples to genetic amniocentesis and subsequent therapeutic abortions due to birth defects. Fourteen women and 12 men were interviewed by experienced interviewers using a structured format designed by the authors, and each interview was audiotaped for later rating. The 5 raters (all women) were instructed to independently rate each interview using forms designed by the authors to elicit information about many aspects of the participant's individual responses as well as perceptions of spouse's responses to the process of pregnancy, amniocentesis, therapeutic abortion, and sequelae. Ratings of all 5 raters were conjoined and an homogeneous narrative was constructed for each interview. Results indicate, in general, that the respondent couples coped well with this experience. In fact 70 per cent of the respondent couples described their marital relationships as becoming closer as a result of their experience. Only a few participants reported long-term deleterious effects. Most couples coped by relying on relatives, friends, and occasionally, professional counsellors. In addition, most participants in this study suggested ways to improve the medical and psychological aspects of this experience.
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