title: A20 suppresses vascular inflammation by recruiting proinflammatory signaling molecules to intracellular aggresomes.
abstract: A20 protects against pathologic vascular remodeling by inhibiting the inflammatory transcription factor NF-κB. A20's function has been attributed to ubiquitin editing of receptor-interacting protein 1 (RIP1) to influence activity/stability. The validity of this mechanism was tested using a murine model of transplant vasculopathy and human cells. Mouse C57BL/6 aortae transduced with adenoviruses containing A20 (or β-galactosidase as a control) were allografted into major histocompatibility complex-mismatched BALB/c mice. Primary endothelial cells, smooth muscle cells, or transformed epithelial cells (all human) were transfected with wild-type A20 or with catalytically inactive mutants as a control. NF-κB activity and intracellular localization of RIP1 was monitored by reporter gene assay, immunofluorescent staining, and Western blotting. Native and catalytically inactive versions of A20 had similar inhibitory effects on NF-κB activity (-70% vs. -76%; P > 0.05). A20 promoted localization of RIP1 to insoluble aggresomes in murine vascular allografts and in human cells (53% vs. 0%) without altering RIP1 expression, and this process was increased by the assembly of polyubiquitin chains (87% vs. 28%; P < 0.05). A20 captures polyubiquitinated signaling intermediaries in insoluble aggresomes, thus reducing their bioavailability for downstream NF-κB signaling. This novel mechanism contributes to protection from vasculopathy in transplanted organs treated with exogenous A20.
authors: *British Heart Foundation Cardiovascular Sciences Unit, Imperial College London, London, United Kingdom; Division of Vascular and Endovascular Surgery, Center for Vascular Biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Cambridge, Massachusetts, USA; and Department of Cardiovascular Sciences and INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom.
authors: Karine
authors: K
authors: Enesa
authors: *British Heart Foundation Cardiovascular Sciences Unit, Imperial College London, London, United Kingdom; Division of Vascular and Endovascular Surgery, Center for Vascular Biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Cambridge, Massachusetts, USA; and Department of Cardiovascular Sciences and INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom.
authors: Herwig P
authors: HP
authors: Moll
authors: *British Heart Foundation Cardiovascular Sciences Unit, Imperial College London, London, United Kingdom; Division of Vascular and Endovascular Surgery, Center for Vascular Biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Cambridge, Massachusetts, USA; and Department of Cardiovascular Sciences and INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom.
authors: Le
authors: L
authors: Luong
authors: *British Heart Foundation Cardiovascular Sciences Unit, Imperial College London, London, United Kingdom; Division of Vascular and Endovascular Surgery, Center for Vascular Biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Cambridge, Massachusetts, USA; and Department of Cardiovascular Sciences and INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom.
authors: Christiane
authors: C
authors: Ferran
authors: *British Heart Foundation Cardiovascular Sciences Unit, Imperial College London, London, United Kingdom; Division of Vascular and Endovascular Surgery, Center for Vascular Biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Cambridge, Massachusetts, USA; and Department of Cardiovascular Sciences and INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom paul.evans@sheffield.ac.uk.
authors: Paul C
authors: PC
authors: Evans
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D064591:Allografts; D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology / Q000637:transplantation*; D015153:Blotting, Western; D002339:Carotid Arteries / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D006084:Graft Rejection / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D006648:Histocompatibility; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007124:Immunoenzyme Techniques; D007249:Inflammation / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D066329:Protein Aggregates / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D025801:Ubiquitin / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D020690:GTPase-Activating Proteins; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D066329:Protein Aggregates; D012333:RNA, Messenger; C490620:Ralbp1 protein, mouse; D025801:Ubiquitin; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D003546:Cysteine Endopeptidases; C513261:Tnfaip3 protein, mouse
keywords: NF-κB; molecular mechanism; receptor interacting protein