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Kennedy JI, Davies SP, Hewett PW, Wilkinson AL, Oo YH, Lu WY, El Haj AJ, Shetty S. Organ-on-a-chip for studying immune cell adhesion to liver sinusoidal endothelial cells: the potential for testing immunotherapies and cell therapy trafficking. Front Cell Dev Biol 2024; 12:1359451. [PMID: 38694823 PMCID: PMC11061353 DOI: 10.3389/fcell.2024.1359451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 04/01/2024] [Indexed: 05/04/2024] Open
Abstract
Immunotherapy has changed the landscape of treatment options for patients with hepatocellular cancer. Checkpoint inhibitors are now standard of care for patients with advanced tumours, yet the majority remain resistant to this therapy and urgent approaches are needed to boost the efficacy of these agents. Targeting the liver endothelial cells, as the orchestrators of immune cell recruitment, within the tumour microenvironment of this highly vascular cancer could potentially boost immune cell infiltration. We demonstrate the successful culture of primary human liver endothelial cells in organ-on-a-chip technology followed by perfusion of peripheral blood mononuclear cells. We confirm, with confocal and multiphoton imaging, the capture and adhesion of immune cells in response to pro-inflammatory cytokines in this model. This multicellular platform sets the foundation for testing the efficacy of new therapies in promoting leukocyte infiltration across liver endothelium as well as a model for testing cell therapy, such as chimeric antigen receptor (CAR)-T cell, capture and migration across human liver endothelium.
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Affiliation(s)
- James I. Kennedy
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Scott P. Davies
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Peter W. Hewett
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Alex L. Wilkinson
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- OMass Therapeutics, Oxford Business Park, Oxford, United Kingdom
| | - Ye H. Oo
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Research, Birmingham Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Wei-Yu Lu
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Alicia J. El Haj
- National Institute for Health Research, Birmingham Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Healthcare Technologies Institute, Institute of Translational Medicine, School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Shishir Shetty
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Research, Birmingham Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
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2
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Davies SP, Ronca V, Wootton GE, Krajewska NM, Bozward AG, Fiancette R, Patten DA, Yankouskaya K, Reynolds GM, Pat S, Osei-Bordom DC, Richardson N, Grover LM, Weston CJ, Oo YH. Expression of E-cadherin by CD8 + T cells promotes their invasion into biliary epithelial cells. Nat Commun 2024; 15:853. [PMID: 38286990 PMCID: PMC10825166 DOI: 10.1038/s41467-024-44910-2] [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: 02/15/2023] [Accepted: 01/03/2024] [Indexed: 01/31/2024] Open
Abstract
The presence of CD8+ T cells in the cytoplasm of biliary epithelial cells (BEC) has been correlated with biliary damage associated with primary biliary cholangitis (PBC). Here, we characterise the mechanism of CD8+ T cell invasion into BEC. CD8+ T cells observed within BEC were large, eccentric, and expressed E-cadherin, CD103 and CD69. They were also not contained within secondary vesicles. Internalisation required cytoskeletal rearrangements which facilitated contact with BEC. Internalised CD8+ T cells were observed in both non-cirrhotic and cirrhotic diseased liver tissues but enriched in PBC patients, both during active disease and at the time of transplantation. E-cadherin expression by CD8+ T cells correlated with frequency of internalisation of these cells into BEC. E-cadherin+ CD8+ T cells formed β-catenin-associated interactions with BEC, were larger than E-cadherin- CD8+ T cells and invaded into BEC more frequently. Overall, we unveil a distinct cell-in-cell structure process in the liver detailing the invasion of E-cadherin+ CD103+ CD69+ CD8+ T cells into BEC.
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Affiliation(s)
- Scott P Davies
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK.
| | - Vincenzo Ronca
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK
| | - Grace E Wootton
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK
- Birmingham Advanced Cellular Therapy Facility, University of Birmingham, Birmingham, UK
| | - Natalia M Krajewska
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Amber G Bozward
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK
- Birmingham Advanced Cellular Therapy Facility, University of Birmingham, Birmingham, UK
| | - Rémi Fiancette
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Daniel A Patten
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Katharina Yankouskaya
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Gary M Reynolds
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Sofia Pat
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Daniel C Osei-Bordom
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Naomi Richardson
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK
- Birmingham Advanced Cellular Therapy Facility, University of Birmingham, Birmingham, UK
| | - Liam M Grover
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
- Healthcare Technologies Institute, University of Birmingham, Birmingham, UK
| | - Christopher J Weston
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Ye H Oo
- Centre for Liver and Gastrointestinal Research, Institute of Biomedical Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.
- National Institute of Health Research Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- European Reference Network on Hepatological Diseases (ERN Rare-Liver), Birmingham, UK.
- Birmingham Advanced Cellular Therapy Facility, University of Birmingham, Birmingham, UK.
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3
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Wiggins BG, Pallett LJ, Li X, Davies SP, Amin OE, Gill US, Kucykowicz S, Patel AM, Aliazis K, Liu YS, Reynolds GM, Davidson BR, Gander A, Luong TV, Hirschfield GM, Kennedy PTF, Huang Y, Maini MK, Stamataki Z. The human liver microenvironment shapes the homing and function of CD4 + T-cell populations. Gut 2022; 71:1399-1411. [PMID: 34548339 PMCID: PMC9185819 DOI: 10.1136/gutjnl-2020-323771] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 08/19/2021] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Tissue-resident memory T cells (TRM) are vital immune sentinels that provide protective immunity. While hepatic CD8+ TRM have been well described, little is known about the location, phenotype and function of CD4+ TRM. DESIGN We used multiparametric flow cytometry, histological assessment and novel human tissue coculture systems to interrogate the ex vivo phenotype, function and generation of the intrahepatic CD4+ T-cell compartment. We also used leukocytes isolated from human leukocyte antigen (HLA)-disparate liver allografts to assess long-term retention. RESULTS Hepatic CD4+ T cells were delineated into three distinct populations based on CD69 expression: CD69-, CD69INT and CD69HI. CD69HICD4+ cells were identified as tissue-resident CD4+ T cells on the basis of their exclusion from the circulation, phenotypical profile (CXCR6+CD49a+S1PR1-PD-1+) and long-term persistence within the pool of donor-derived leukcoocytes in HLA-disparate liver allografts. CD69HICD4+ T cells produced robust type 1 polyfunctional cytokine responses on stimulation. Conversely, CD69INTCD4+ T cells represented a more heterogenous population containing cells with a more activated phenotype, a distinct chemokine receptor profile (CX3CR1+CXCR3+CXCR1+) and a bias towards interleukin-4 production. While CD69INTCD4+ T cells could be found in the circulation and lymph nodes, these cells also formed part of the long-term resident pool, persisting in HLA-mismatched allografts. Notably, frequencies of CD69INTCD4+ T cells correlated with necroinflammatory scores in chronic hepatitis B infection. Finally, we demonstrated that interaction with hepatic epithelia was sufficient to generate CD69INTCD4+ T cells, while additional signals from the liver microenvironment were required to generate liver-resident CD69HICD4+ T cells. CONCLUSIONS High and intermediate CD69 expressions mark human hepatic CD4+ TRM and a novel functionally distinct recirculating population, respectively, both shaped by the liver microenvironment to achieve diverse immunosurveillance.
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Affiliation(s)
- Benjamin G Wiggins
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Laura J Pallett
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Xiaoyan Li
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Department of Infectious Diseases and Guangdong Provincial Key Laboratory of Liver Disease Research, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Scott P Davies
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Oliver E Amin
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | | | - Stephanie Kucykowicz
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Arzoo M Patel
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Konstantinos Aliazis
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Yuxin S Liu
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Gary M Reynolds
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | | | - Amir Gander
- Tissue Access for Patient Benefit, University College London, London, UK
| | - Tu Vinh Luong
- Department of Cellular Pathology, Royal Free Hospital, London, UK
| | - Gideon M Hirschfield
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
- Centre for Liver Research, National Institute for Health Research Biomedical Research Unit, University of Birmingham, Birmingham, UK
| | | | - Yuehua Huang
- Department of Infectious Diseases, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Liver Disease Research, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Mala K Maini
- Division of Infection and Immunity, Rayne Institute, University College London, London, UK
| | - Zania Stamataki
- Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
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4
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Patel AM, Liu YS, Davies SP, Brown RM, Kelly DA, Scheel-Toellner D, Reynolds GM, Stamataki Z. The Role of B Cells in Adult and Paediatric Liver Injury. Front Immunol 2021; 12:729143. [PMID: 34630404 PMCID: PMC8495195 DOI: 10.3389/fimmu.2021.729143] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 06/22/2021] [Accepted: 08/16/2021] [Indexed: 12/16/2022] Open
Abstract
B lymphocytes are multitasking cells that direct the immune response by producing pro- or anti-inflammatory cytokines, by presenting processed antigen for T cell activation and co-stimulation, and by turning into antibody-secreting cells. These functions are important to control infection in the liver but can also exacerbate tissue damage and fibrosis as part of persistent inflammation that can lead to end stage disease requiring a transplant. In transplantation, immunosuppression increases the incidence of lymphoma and often this is of B cell origin. In this review we bring together information on liver B cell biology from different liver diseases, including alcohol-related and metabolic fatty liver disease, autoimmune hepatitis, primary biliary and primary sclerosing cholangitis, viral hepatitis and, in infants, biliary atresia. We also discuss the impact of B cell depletion therapy in the liver setting. Taken together, our analysis shows that B cells are important in the pathogenesis of liver diseases and that further research is necessary to fully characterise the human liver B cell compartment.
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Affiliation(s)
- Arzoo M. Patel
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Yuxin S. Liu
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Scott P. Davies
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Rachel M. Brown
- Department of Histopathology, Queen Elizabeth Hospital, Birmingham Women’s and Children’s National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
| | - Deirdre A. Kelly
- The Liver Unit, Birmingham Women’s and Children’s Hospital and the University of Birmingham, Birmingham, United Kingdom
| | - Dagmar Scheel-Toellner
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Gary M. Reynolds
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- The Liver Unit, Birmingham Women’s and Children’s Hospital and the University of Birmingham, Birmingham, United Kingdom
| | - Zania Stamataki
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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5
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Melidis L, Hill HJ, Coltman NJ, Davies SP, Winczura K, Chauhan T, Craig JS, Garai A, Hooper CAJ, Egan RT, McKeating JA, Hodges NJ, Stamataki Z, Grzechnik P, Hannon MJ. Supramolecular Cylinders Target Bulge Structures in the 5' UTR of the RNA Genome of SARS-CoV-2 and Inhibit Viral Replication. Angew Chem Weinheim Bergstr Ger 2021; 133:18292-18299. [PMID: 38505190 PMCID: PMC10947172 DOI: 10.1002/ange.202104179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 01/09/2023]
Abstract
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
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Affiliation(s)
- Lazaros Melidis
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Harriet J. Hill
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | | | - Scott P. Davies
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Kinga Winczura
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Tasha Chauhan
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - James S. Craig
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Aditya Garai
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | | | - Ross T. Egan
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Jane A. McKeating
- Nuffield Department of Medicine & Chinese Academy of Medical Sciences (CAMS) Oxford Institute (COI)Oxford UniversityOxfordOX3 7BNUK
| | - Nikolas J. Hodges
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Zania Stamataki
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Pawel Grzechnik
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Michael J. Hannon
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
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6
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Melidis L, Hill HJ, Coltman NJ, Davies SP, Winczura K, Chauhan T, Craig JS, Garai A, Hooper CAJ, Egan RT, McKeating JA, Hodges NJ, Stamataki Z, Grzechnik P, Hannon MJ. Supramolecular Cylinders Target Bulge Structures in the 5' UTR of the RNA Genome of SARS-CoV-2 and Inhibit Viral Replication*. Angew Chem Int Ed Engl 2021; 60:18144-18151. [PMID: 33915014 PMCID: PMC8222931 DOI: 10.1002/anie.202104179] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 03/25/2021] [Indexed: 12/13/2022]
Abstract
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
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Affiliation(s)
- Lazaros Melidis
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Harriet J. Hill
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | | | - Scott P. Davies
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Kinga Winczura
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Tasha Chauhan
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - James S. Craig
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Aditya Garai
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | | | - Ross T. Egan
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Jane A. McKeating
- Nuffield Department of Medicine & Chinese Academy of Medical Sciences (CAMS) Oxford Institute (COI)Oxford UniversityOxfordOX3 7BNUK
| | - Nikolas J. Hodges
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Zania Stamataki
- Institute of Immunology and ImmunotherapyUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Pawel Grzechnik
- School of BiosciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Michael J. Hannon
- Physical Sciences for Health CentreUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
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7
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Davies SP, Mycroft-West CJ, Pagani I, Hill HJ, Chen YH, Karlsson R, Bagdonaite I, Guimond SE, Stamataki Z, De Lima MA, Turnbull JE, Yang Z, Vicenzi E, Skidmore MA, Khanim FL, Richardson A. The Hyperlipidaemic Drug Fenofibrate Significantly Reduces Infection by SARS-CoV-2 in Cell Culture Models. Front Pharmacol 2021; 12:660490. [PMID: 34421587 PMCID: PMC8377159 DOI: 10.3389/fphar.2021.660490] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/28/2021] [Indexed: 12/15/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has caused a significant number of fatalities and worldwide disruption. To identify drugs to repurpose to treat SARS-CoV-2 infections, we established a screen to measure the dimerization of angiotensin-converting enzyme 2 (ACE2), the primary receptor for the virus. This screen identified fenofibric acid, the active metabolite of fenofibrate. Fenofibric acid also destabilized the receptor-binding domain (RBD) of the viral spike protein and inhibited RBD binding to ACE2 in enzyme-linked immunosorbent assay (ELISA) and whole cell-binding assays. Fenofibrate and fenofibric acid were tested by two independent laboratories measuring infection of cultured Vero cells using two different SARS-CoV-2 isolates. In both settings at drug concentrations, which are clinically achievable, fenofibrate and fenofibric acid reduced viral infection by up to 70%. Together with its extensive history of clinical use and its relatively good safety profile, this study identifies fenofibrate as a potential therapeutic agent requiring an urgent clinical evaluation to treat SARS-CoV-2 infection.
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Affiliation(s)
- Scott P Davies
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Courtney J Mycroft-West
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Isabel Pagani
- Viral Pathogenesis and Biosafety Unit, San Raffaele Scientific Institute Via Olgettina, Milano, Italy
| | - Harriet J Hill
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Yen-Hsi Chen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Richard Karlsson
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ieva Bagdonaite
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Scott E Guimond
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Zania Stamataki
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Marcelo Andrade De Lima
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Jeremy E Turnbull
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Zhang Yang
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisa Vicenzi
- Viral Pathogenesis and Biosafety Unit, San Raffaele Scientific Institute Via Olgettina, Milano, Italy
| | - Mark A Skidmore
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Farhat L Khanim
- School of Biomedical Sciences, Institute for Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Alan Richardson
- School of Pharmacy and Bioengineering, Keele University, Staffordshire, United Kingdom
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8
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Moakes RJA, Davies SP, Stamataki Z, Grover LM. Formulation of a Composite Nasal Spray Enabling Enhanced Surface Coverage and Prophylaxis of SARS-COV-2. Adv Mater 2021; 33:e2008304. [PMID: 34060150 PMCID: PMC8212080 DOI: 10.1002/adma.202008304] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/26/2021] [Indexed: 05/18/2023]
Abstract
Airborne pathogens pose high risks in terms of both contraction and transmission within the respiratory pathways, particularly the nasal region. However, there is little in the way of adequate intervention that can protect an individual or prevent further spread. This study reports on a nasal formulation with the capacity to combat such challenges, focusing on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Formulation of a polysaccharide-based spray, known for its mucoadhesive properties, is undertaken and it is characterized for its mechanical, spray distribution, and antiviral properties. The ability to engineer key mechanical characteristics such as dynamic yield stresses and high coverage is shown, through systematic understanding of the composite mixture containing both gellan and λ-carrageenan. Furthermore, the spray systems demonstrate highly potent capacities to prevent SARS-CoV-2 infection in Vero cells, resulting in complete inhibition when either treating, the cells, or the virus, prior to challenging for infection. From this data, a mechanism for both prophylaxis and prevention is proposed; where entrapment within a polymeric coating sterically blocks virus uptake into the cells, inactivating the virus, and allowing clearance within the viscous medium. As such, a fully preventative spray is formulated, targeted at protecting the lining of the upper respiratory pathways against SARS-CoV-2.
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Affiliation(s)
- Richard J. A. Moakes
- Healthcare Technology InstituteSchool of Chemical EngineeringUniversity of BirminghamBirminghamB15 2TTUK
| | - Scott P. Davies
- Institute of Immunology and ImmunotherapySchool of Medicine and DentistryUniversity of BirminghamBirminghamB15 2GWUK
| | - Zania Stamataki
- Institute of Immunology and ImmunotherapySchool of Medicine and DentistryUniversity of BirminghamBirminghamB15 2GWUK
| | - Liam M. Grover
- Healthcare Technology InstituteSchool of Chemical EngineeringUniversity of BirminghamBirminghamB15 2TTUK
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9
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Aghabi YO, Yasin A, Kennedy JI, Davies SP, Butler AE, Stamataki Z. Targeting Enclysis in Liver Autoimmunity, Transplantation, Viral Infection and Cancer. Front Immunol 2021; 12:662134. [PMID: 33953725 PMCID: PMC8089374 DOI: 10.3389/fimmu.2021.662134] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 01/31/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Persistent liver inflammation can lead to cirrhosis, which associates with significant morbidity and mortality worldwide. There are no curative treatments beyond transplantation, followed by long-term immunosuppression. The global burden of end stage liver disease has been increasing and there is a shortage of donor organs, therefore new therapies are desperately needed. Harnessing the power of the immune system has shown promise in certain autoimmunity and cancer settings. In the context of the liver, regulatory T cell (Treg) therapies are in development. The hypothesis is that these specialized lymphocytes that dampen inflammation may reduce liver injury in patients with chronic, progressive diseases, and promote transplant tolerance. Various strategies including intrinsic and extracorporeal expansion of Treg cells, aim to increase their abundance to suppress immune responses. We recently discovered that hepatocytes engulf and delete Treg cells by enclysis. Herein, we propose that inhibition of enclysis may potentiate existing regulatory T cell therapeutic approaches in patients with autoimmune liver diseases and in patients receiving a transplant. Moreover, in settings where the abundance of Treg cells could hinder beneficial immunity, such us in chronic viral infection or liver cancer, enhancement of enclysis could result in transient, localized reduction of Treg cell numbers and tip the balance towards antiviral and anti-tumor immunity. We describe enclysis as is a natural process of liver immune regulation that lends itself to therapeutic targeting, particularly in combination with current Treg cell approaches.
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Affiliation(s)
| | | | | | | | | | - Zania Stamataki
- College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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10
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Abstract
The liver is our largest internal organ and it plays major roles in drug detoxification and immunity, where the ingestion of extracellular material through phagocytosis is a critical pathway. Phagocytosis is the deliberate endocytosis of large particles, microbes, dead cells or cell debris and can lead to cell-in-cell structures. Various types of cell endocytosis have been recently described for hepatic epithelia (hepatocytes), which are non-professional phagocytes. Given that up to 80% of the liver comprises hepatocytes, the biological impact of cell-in-cell structures in the liver can have profound effects in liver regeneration, inflammation and cancer. This review brings together the latest reports on four types of endocytosis in the liver -efferocytosis, entosis, emperipolesis and enclysis, with a focus on hepatocyte biology.
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Affiliation(s)
- Scott P Davies
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Lauren V Terry
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Alex L Wilkinson
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Zania Stamataki
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,NIHR Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
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11
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Davies SP, Reynolds GM, Wilkinson AL, Li X, Rose R, Leekha M, Liu YS, Gandhi R, Buckroyd E, Grove J, Barnes NM, May RC, Hubscher SG, Adams DH, Huang Y, Qureshi O, Stamataki Z. Hepatocytes Delete Regulatory T Cells by Enclysis, a CD4 + T Cell Engulfment Process. Cell Rep 2019; 29:1610-1620.e4. [PMID: 31693899 PMCID: PMC7057271 DOI: 10.1016/j.celrep.2019.09.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 06/03/2019] [Accepted: 09/20/2019] [Indexed: 12/13/2022] Open
Abstract
CD4+ T cells play critical roles in directing immunity, both as T helper and as regulatory T (Treg) cells. Here, we demonstrate that hepatocytes can modulate T cell populations through engulfment of live CD4+ lymphocytes. We term this phenomenon enclysis to reflect the specific enclosure of CD4+ T cells in hepatocytes. Enclysis is selective for CD4+ but not CD8+ cells, independent of antigen-specific activation, and occurs in human hepatocytes in vitro, ex vivo, and in vivo. Intercellular adhesion molecule 1 (ICAM-1) facilitates T cell early adhesion and internalization, whereas hepatocytes form membrane lamellipodia or blebs to mediate engulfment. T cell internalization is unaffected by wortmannin and Rho kinase inhibition. Hepatocytes engulf Treg cells more efficiently than non-Treg cells, but Treg cell-containing vesicles preferentially acidify overnight. Thus, enclysis is a biological process with potential effects on immunomodulation and opens a new field for research to fully understand CD4+ T cell dynamics in liver inflammation.
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Affiliation(s)
- Scott P Davies
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Gary M Reynolds
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK; NIHR Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Alex L Wilkinson
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Xiaoyan Li
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK; Department of Infectious Diseases and Guangdong Provincial Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Rebecca Rose
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Maanav Leekha
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Yuxin S Liu
- Institute of Inflammation and Aging, University of Birmingham, Birmingham, UK
| | - Ratnam Gandhi
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Emma Buckroyd
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Nicholas M Barnes
- Neuropharmacology Research Group, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Robin C May
- Institute of Microbiology and Infection and School of Biosciences, University of Birmingham, Birmingham, UK
| | - Stefan G Hubscher
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK; NIHR Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; Department of Cellular Pathology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - David H Adams
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK; NIHR Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Yuehua Huang
- Department of Infectious Diseases and Guangdong Provincial Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Omar Qureshi
- Celentyx Ltd., Birmingham Research Park, Birmingham B15 2SQ, UK; Celentyx Ltd., BioEscalator Innovation Building, Oxford OX3 7FZ, UK
| | - Zania Stamataki
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK; NIHR Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
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12
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Triantafyllou E, Pop OT, Possamai LA, Wilhelm A, Liaskou E, Singanayagam A, Bernsmeier C, Khamri W, Petts G, Dargue R, Davies SP, Tickle J, Yuksel M, Patel VC, Abeles RD, Stamataki Z, Curbishley SM, Ma Y, Wilson ID, Coen M, Woollard KJ, Quaglia A, Wendon J, Thursz MR, Adams DH, Weston CJ, Antoniades CG. MerTK expressing hepatic macrophages promote the resolution of inflammation in acute liver failure. Gut 2018; 67:333-347. [PMID: 28450389 PMCID: PMC5868289 DOI: 10.1136/gutjnl-2016-313615] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/24/2017] [Accepted: 03/31/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response. DESIGN Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer-/-) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice. RESULTS We demonstrate a significant expansion of resolution-like MerTK+HLA-DRhigh cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCIIhigh macrophages during the resolution phase in ALF, APAP-treated Mer-/- mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DRhigh phenotype which promotes neutrophil apoptosis and their subsequent clearance. CONCLUSIONS We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury.
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Affiliation(s)
- Evangelos Triantafyllou
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK,Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK,National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Oltin T Pop
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Lucia A Possamai
- Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - Annika Wilhelm
- Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - Evaggelia Liaskou
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Arjuna Singanayagam
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK,Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - Christine Bernsmeier
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Wafa Khamri
- Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - Gemma Petts
- Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - Rebecca Dargue
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Scott P Davies
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Joseph Tickle
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Muhammed Yuksel
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Vishal C Patel
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Robin D Abeles
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Zania Stamataki
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Stuart M Curbishley
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Yun Ma
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Ian D Wilson
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Muireann Coen
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Kevin J Woollard
- Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London, UK
| | - Alberto Quaglia
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Julia Wendon
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK
| | - Mark R Thursz
- Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK
| | - David H Adams
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Chris J Weston
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Charalambos G Antoniades
- Institute of Liver Studies, King's College Hospital, King's College London, London, UK,Division of Digestive Diseases, St Mary's Hospital, Imperial College London, London, UK,National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
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13
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Davies SP, Reynolds GM, Stamataki Z. Clearance of Apoptotic Cells by Tissue Epithelia: A Putative Role for Hepatocytes in Liver Efferocytosis. Front Immunol 2018; 9:44. [PMID: 29422896 PMCID: PMC5790054 DOI: 10.3389/fimmu.2018.00044] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/08/2018] [Indexed: 12/11/2022] Open
Abstract
Toxic substances and microbial or food-derived antigens continuously challenge the liver, which is tasked with their safe neutralization. This vital organ is also important for the removal of apoptotic immune cells during inflammation and has been previously described as a “graveyard” for dying lymphocytes. The clearance of apoptotic and necrotic cells is known as efferocytosis and is a critical liver function to maintain tissue homeostasis. Much of the research into this form of immunological control has focused on Kupffer cells, the liver-resident macrophages. However, hepatocytes (and other liver resident cells) are competent efferocytes and comprise 80% of the liver mass. Little is known regarding the mechanisms of apoptotic and necrotic cell capture by epithelia, which lack key receptors that mediate phagocytosis in macrophages. Herein, we discuss recent developments that increased our understanding of efferocytosis in tissues, with a special focus on the liver parenchyma. We discuss the impact of efferocytosis in health and in inflammation, highlighting the role of phagocytic epithelia.
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Affiliation(s)
- Scott P Davies
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Gary M Reynolds
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,Centre for Liver Research and National Institute for Health Research (NIHR) Birmingham Liver Biomedical Research Unit, College of Medical and Dental Sciences, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Zania Stamataki
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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14
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Patten DA, Hussein E, Davies SP, Humphreys PN, Collett A. Commensal-derived OMVs elicit a mild proinflammatory response in intestinal epithelial cells. Microbiology (Reading) 2017; 163:702-711. [PMID: 28530169 DOI: 10.1099/mic.0.000468] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Under normal physiological conditions, the intestinal immunity remains largely hyporesponsive to the commensal microbiota, yet also retains the inherent ability to rapidly respond to pathogenic antigens. However, immunomodulatory activities of extracellular products from commensal bacteria have been little studied, with previous investigations generally utilizing the live bacterium to study microbiota-epithelial interactions. In this study, we demonstrate that extracellular products of a commensal bacterium, Escherichia coli C25, elicit a moderate release of proinflammatory IL-8 and stimulate transcriptional up-regulation of Toll-like receptors (TLRs) in intestinal epithelial cell lines HT29-19A and Caco-2. Additionally, we show that removal of outer membrane vesicles (OMVs) reduces the proinflammatory effect of secreted products from E. coli C25. Furthermore, we show that isolated OMVs have a dose-dependent proinflammatory effect on intestinal epithelial cells (IECs). Interestingly, a relatively high concentration (40 µg ml-1 protein) of OMVs had no significant regulatory effects on TLR mRNA expression in both cell lines. Finally, we also demonstrate that pre-incubation with E. coli C25-derived OMVs subsequently inhibited the internalization of the bacterium itself in both cell lines. Taken together, our results suggest that commensal-derived extracellular products, in particular OMVs, could significantly contribute to intestinal homeostasis. We also demonstrate a unique interaction between commensal-derived OMVs and host cells.
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Affiliation(s)
- Daniel A Patten
- Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, UK.,Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Enas Hussein
- Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, UK
| | - Scott P Davies
- Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Paul N Humphreys
- Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, UK
| | - Andrew Collett
- Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, UK
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15
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Davies SP, Kox WJ, Brown EA. Clearance studies in patients with acute renal failure treated by continuous arteriovenous haemodialysis. Contrib Nephrol 2015; 93:117-9. [PMID: 1802558 DOI: 10.1159/000420198] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S P Davies
- Charing Cross and Westminister Medical School, London, UK
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16
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Sarno S, Reddy H, Meggio F, Ruzzene M, Davies SP, Donella-Deana A, Shugar D, Pinna LA. Selectivity of 4,5,6,7-tetrabromobenzotriazole, an ATP site-directed inhibitor of protein kinase CK2 ('casein kinase-2'). FEBS Lett 2001; 496:44-8. [PMID: 11343704 DOI: 10.1016/s0014-5793(01)02404-8] [Citation(s) in RCA: 289] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The specificity of 4,5,6,7-tetrabromo-2-azabenzimidazole (TBB), an ATP/GTP competitive inhibitor of protein kinase casein kinase-2 (CK2), has been examined against a panel of 33 protein kinases, either Ser/Thr- or Tyr-specific. In the presence of 10 microM TBB (and 100 microM ATP) only CK2 was drastically inhibited (>85%) whereas three kinases (phosphorylase kinase, glycogen synthase kinase 3 beta and cyclin-dependent kinase 2/cyclin A) underwent moderate inhibition, with IC(50) values one--two orders of magnitude higher than CK2 (IC(50)=0.9 microM). TBB also inhibits endogenous CK2 in cultured Jurkat cells. A CK2 mutant in which Val66 has been replaced by alanine is much less susceptible to inhibition by TBB as well as by another ATP competitive inhibitor, emodin. These data show that TBB is a quite selective inhibitor of CK2, that can be used in cell-based assays.
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Affiliation(s)
- S Sarno
- Department of Biological Chemistry, University of Padua, Italy
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17
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Abstract
This paper presents three studies concerned with the evaluation of moves in solutions to Tower of Hanoi problems and the effect that such evaluation processes have on solution success. The existing literature on problem solving suggests that verbalizing whilst solving a problem can have a positive effect upon performance. However, such verbalization has to be directed toward an explicit evaluation of particular moves. What remains unclear is whether evaluation without verbalization has the same effects or whether some characteristic of the process of verbalization gives rise to improved performance on such tasks. For example, the act of verbalizing per se may simply mean that more processing time is directed toward the problem-solving process. The studies reported in this paper suggest that the process of evaluation may be independent of verbalization processes and that non-verbal evaluation of moves (indicated by a key press) produces the same effects as a verbal evaluation of such moves. Moreover, the process of evaluating moves appears to produce a form of behaviour that is prone to disruption via the administration of secondary tasks, whereas non-evaluated solutions are not. This may suggest that problem solvers who engage in evaluation processes develop an explicit representation of the strategies used to solve the problem.
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Affiliation(s)
- S P Davies
- Department of Psychology, University of Hull, Cottingham Road, Hull, HU6 7RX, U.K.
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18
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Abstract
The specificities of 28 commercially available compounds reported to be relatively selective inhibitors of particular serine/threonine-specific protein kinases have been examined against a large panel of protein kinases. The compounds KT 5720, Rottlerin and quercetin were found to inhibit many protein kinases, sometimes much more potently than their presumed targets, and conclusions drawn from their use in cell-based experiments are likely to be erroneous. Ro 318220 and related bisindoylmaleimides, as well as H89, HA1077 and Y 27632, were more selective inhibitors, but still inhibited two or more protein kinases with similar potency. LY 294002 was found to inhibit casein kinase-2 with similar potency to phosphoinositide (phosphatidylinositol) 3-kinase. The compounds with the most impressive selectivity profiles were KN62, PD 98059, U0126, PD 184352, rapamycin, wortmannin, SB 203580 and SB 202190. U0126 and PD 184352, like PD 98059, were found to block the mitogen-activated protein kinase (MAPK) cascade in cell-based assays by preventing the activation of MAPK kinase (MKK1), and not by inhibiting MKK1 activity directly. Apart from rapamycin and PD 184352, even the most selective inhibitors affected at least one additional protein kinase. Our results demonstrate that the specificities of protein kinase inhibitors cannot be assessed simply by studying their effect on kinases that are closely related in primary structure. We propose guidelines for the use of protein kinase inhibitors in cell-based assays.
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Affiliation(s)
- S P Davies
- Division of Signal Transduction Therapy, University of Dundee, Dundee DD1 5EH, Scotland, UK
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19
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Abstract
Although many studies in the problem-solving literature have considered the factors that might determine the strategies that are employed to solve well-structured problems, these have typically focused upon variants of means-end analysis. In general, such models imply that strategies unfold in a temporally forward direction, that problem solvers typically restrict forward-planning activities to just one or two moves ahead of the current problem state, and that one important heuristic is the avoidance of previous moves. Although studies have demonstrated the importance of such anti-looping heuristics, few have systematically explored the possibility that problem solvers may also plan retrospectively in order to try and assess whether a move might take them back to a state that they have previously visited. Those models of problem solving that promote the role of an anti-looping heuristic have assumed that the ability to use such a heuristic is based upon memory for previous states, but other interpretations are possible. In this paper several studies are reported that attempt systematically to explore participants' attempts to recognize previously visited problem-solving states. The findings suggest that there is a systematic relationship between the success of this process, the time taken to make this judgement, and distance from the current state. It is also demonstrated that estimations about where future positions are likely to occur are symmetrical to estimations about past positions. It is suggested that this provides evidence that problem solvers engage in retrospective planning processes in order to try and avoid previous moves, and that this strategy may not be based straightforwardly upon their ability to remember previous problem states.
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Affiliation(s)
- S P Davies
- Department of Psychology, University of Hull, U.K.
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20
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Cheung PC, Salt IP, Davies SP, Hardie DG, Carling D. Characterization of AMP-activated protein kinase gamma-subunit isoforms and their role in AMP binding. Biochem J 2000; 346 Pt 3:659-69. [PMID: 10698692 PMCID: PMC1220898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The AMP-activated protein kinase (AMPK) cascade plays an important role in the regulation of energy homeostasis within the cell. AMPK is a heterotrimer composed of a catalytic subunit (alpha) and two regulatory subunits (beta and gamma). We have isolated and characterized two isoforms of the gamma subunit, termed gamma2 and gamma3. Both gamma2 (569 amino acids) and gamma3 (492 amino acids) have a long N-terminal domain which is not present in the previously characterized isoform, gamma1. As with gamma1, mRNA encoding gamma2 is widely expressed in human tissues, whereas significant expression of gamma3 mRNA was only detected in skeletal muscle. Using isoform-specific antibodies, we determined the AMPK activity associated with the different gamma isoforms in a number of rat tissues. In most tissues examined more than 80% of total AMPK activity was associated with the gamma1 isoform, with the remaining activity being accounted for mainly by the gamma2 isoform. Exceptions to this were testis and, more notably, brain where all three isoforms contributed approximately equally to activity. There was no evidence for any selective association between the alpha1 and alpha2isoforms and the various gamma isoforms. However, the AMP-dependence of the kinase complex is markedly affected by the identity of the gamma isoform present, with gamma2-containing complexes having the greatest AMP-dependence, gamma3 the lowest, and gamma1 having an intermediate effect. Labelling studies, using the reactive AMP analogue 8-azido-[(32)P]AMP, indicate that the gamma subunit may participate directly in the binding of AMP within the complex.
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Affiliation(s)
- P C Cheung
- Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, Du Cane Road, London W12 0NN, U.K
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21
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Affiliation(s)
- D G Hardie
- Department of Biochemistry, University of Dundee, UK
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22
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Smith FC, Davies SP, Wilson WA, Carling D, Hardie DG. The SNF1 kinase complex from Saccharomyces cerevisiae phosphorylates the transcriptional repressor protein Mig1p in vitro at four sites within or near regulatory domain 1. FEBS Lett 1999; 453:219-23. [PMID: 10403407 DOI: 10.1016/s0014-5793(99)00725-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mig1p is a zinc finger protein required for repression of glucose-regulated genes in budding yeast. On removal of medium glucose, gene repression is relieved via a mechanism that requires the SNF1 protein kinase complex. We show that Mig1p expressed as a glutathione-S-transferase fusion in bacteria is readily phosphorylated by the SNF1 kinase in vitro. Four phosphorylation sites were identified, i.e. Ser-222, Ser-278, Ser-311 and Ser-381. The latter three are exact matches to the recognition motif we previously defined for SNF1 and lie within regions shown to be required for SNF1-dependent derepression and nuclear-to-cytoplasmic translocation.
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Affiliation(s)
- F C Smith
- MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, UK
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23
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Dyck JR, Kudo N, Barr AJ, Davies SP, Hardie DG, Lopaschuk GD. Phosphorylation control of cardiac acetyl-CoA carboxylase by cAMP-dependent protein kinase and 5'-AMP activated protein kinase. Eur J Biochem 1999; 262:184-90. [PMID: 10231380 DOI: 10.1046/j.1432-1327.1999.00371.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acetyl-CoA carboxylase (ACC) is regarded in liver and adipose tissue to be the rate-limiting enzyme for fatty acid biosynthesis; however, in heart tissue it functions as a regulator of fatty acid oxidation. Because the control of fatty acid oxidation is important to the functioning myocardium, the regulation of ACC is a key issue. Two cardiac isoforms of ACC exist, with molecular masses of 265 kDa and 280 kDa (ACC265 and ACC280). In this study, these proteins were purified from rat heart and used in subsequent phosphorylation and immunoprecipitation experiments. Our results demonstrate that 5' AMP-activated protein kinase (AMPK) is able to phosphorylate both ACC265 and ACC280, resulting in an almost complete loss of ACC activity. Although cAMP-dependent protein kinase phosphorylated only ACC280, a dramatic loss of ACC activity was still observed, suggesting that ACC280 contributes most, if not all, of the total heart ACC activity. ACC280 and ACC265 copurified under all experimental conditions, and purification of heart ACC also resulted in the specific copurification of the alpha2 isoform of the catalytic subunit of AMPK. Although both catalytic subunits of AMPK were expressed in crude heart homogenates, our results suggest that alpha2, and not alpha1, is the dominant isoform of AMPK catalytic subunit regulating ACC in the heart. Immunoprecipitation studies demonstrated that specific antibodies for both ACC265 and ACC280 were able to coimmunoprecipitate the alternate isoform along with the alpha2 isoform of AMPK. Taken together, the immunoprecipitation and the purification studies suggest that the two isoforms of ACC in the heart exist in a heterodimeric structure, and that this structure is tightly associated with the alpha2 subunit of AMPK.
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Affiliation(s)
- J R Dyck
- Cardiovascular Research and Lipid Lipoprotein Research Groups, Department of Pediatrics, Faculty of Medicine, University of Alberta, Canada
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24
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Hardie DG, Salt IP, Hawley SA, Davies SP. AMP-activated protein kinase: an ultrasensitive system for monitoring cellular energy charge. Biochem J 1999; 338 ( Pt 3):717-22. [PMID: 10051444 PMCID: PMC1220108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The AMP-activated protein kinase cascade is activated by elevation of AMP and depression of ATP when cellular energy charge is compromised, leading to inhibition of anabolic pathways and activation of catabolic pathways. Here we show that the system responds in intact cells in an ultrasensitive manner over a critical range of nucleotide concentrations, in that only a 6-fold increase in activating nucleotide is required in order for the maximal activity of the kinase to progress from 10% to 90%, equivalent to a co-operative system with a Hill coefficient (h) of 2.5. Modelling suggests that this sensitivity arises from two features of the system: (i) AMP acts at multiple steps in the cascade (multistep sensitivity); and (ii) the upstream kinase is initially saturated with the downstream kinase (zero-order ultrasensitivity).
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Affiliation(s)
- D G Hardie
- Biochemistry Department, Dundee University, MSI/WTB Complex, Dow Street, Dundee DD1 5EH, Scotland, UK.
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25
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Affiliation(s)
- D G Hardie
- Biochemistry Department, The University, Dundee, Scotland, U.K
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26
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Abstract
Raf-1 is extensively phosphorylated on Ser621 in both quiescent and mitogen-stimulated cells. To identify the responsible kinase(s), cytosolic fractions of NIH 3T3 cells were analyzed for Ser621 peptide kinase activity. One major peak of activity was detected and identified as AMP-activated protein kinase (AMPK) by immunodepletion experiments. AMPK phosphorylated the catalytic domain of Raf-1, expressed in Escherichia coli as a soluble GST fusion protein, to generate a single tryptic [32P]phosphopeptide containing exclusively phospho-Ser621. AMPK also phosphorylated full-length, kinase-defective Raf-1 (K375M) to generate two [32P]phosphopeptides, one co-migrating with synthetic tryptic peptide containing phospho-Ser621 and the other with phospho-Ser259.
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Affiliation(s)
- A B Sprenkle
- Howard Hughes Medical Institute, Department of Medicine, University of Virginia, Charlottesville 22908, USA
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27
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Hawley SA, Davison M, Woods A, Davies SP, Beri RK, Carling D, Hardie DG. Characterization of the AMP-activated protein kinase kinase from rat liver and identification of threonine 172 as the major site at which it phosphorylates AMP-activated protein kinase. J Biol Chem 1996; 271:27879-87. [PMID: 8910387 DOI: 10.1074/jbc.271.44.27879] [Citation(s) in RCA: 933] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We have developed a sensitive assay for the AMP-activated protein kinase kinase, the upstream component in the AMP-activated protein kinase cascade. Phosphorylation and activation of the downstream kinase by the upstream kinase absolutely requires AMP and is antagonized by high (millimolar) concentrations of ATP. We have purified the upstream kinase >1000-fold from rat liver; a variety of evidence indicates that the catalytic subunit may be a polypeptide of 58 kDa. The physical properties of the downstream and upstream kinases, e.g. catalytic subunit masses (63 versus 58 kDa) and native molecular masses (190 versus 195 kDa), are very similar. However, unlike the downstream kinase, the upstream kinase is not inactivated by protein phosphatases. The upstream kinase phosphorylates the downstream kinase at a single major site on the alpha subunit, i.e. threonine 172, which lies in the "activation segment" between the DFG and APE motifs. This site aligns with activating phosphorylation sites on many other protein kinases, including Thr177 on calmodulin-dependent protein kinase I. As well as suggesting a mechanism of activation of AMP-activated protein kinase, this finding is consistent with our recent report that the AMP-activated protein kinase kinase can slowly phosphorylate and activate calmodulin-dependent protein kinase I, at least in vitro (Hawley, S. A., Selbert, M. A., Goldstein, E. G., Edelman, A. M., Carling, D., and Hardie, D. G. (1995) J. Biol. Chem. 270, 27186-27191).
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Affiliation(s)
- S A Hawley
- Biochemistry Department, The University, Dundee DD1 4HN, Scotland, United Kingdom.
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28
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Ching YP, Davies SP, Hardie DG. Analysis of the specificity of the AMP-activated protein kinase by site-directed mutagenesis of bacterially expressed 3-hydroxy 3-methylglutaryl-CoA reductase, using a single primer variant of the unique-site-elimination method. Eur J Biochem 1996; 237:800-8. [PMID: 8647128 DOI: 10.1111/j.1432-1033.1996.0800p.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The specificity of protein kinases is usually examined using synthetic peptide substrates, either designed variants, or, more recently random peptide libraries. However not all protein kinases utilize synthetic peptides efficiently as substrates. Even among those that do, these approaches neglect effects caused by three-dimensional protein conformation, or the existence of determinants remote from the phosphorylation site. To follow up our previous peptide studies on the specificity of the AMP-activated protein kinase (AMPK) [Dale, S., Wilson, W. A., Edelman, A.M., & Hardie, D. G. (1995) FEBS Lett. 361, 191-195], we have expressed the C-terminal, catalytic domain of Chinese hamster hydroxymethylglutaryl-CoA reductase in Escherichia coli. The domain was expressed with an N-terminal His6 tag which allowed rapid purification on Nj(2+)-agarose. The purified protein retained full enzymic activity, and as with the native enzyme, was totally inactivated by phosphorylation by AMPK at a single site corresponding to Ser871. Using a novel modification of the unique-site elimination method (which allowed direct mutagenesis of the double-stranded expression vector using a single oligonucleotide primer) we expressed 18 mutations involving residues around Ser871. The results broadly confirmed the recognition motif previously proposed on the basis of peptide studies. Three of the mutants were better substrates for AMPK than the wild type, and one of these (K872A) had hydroxymethylglutaryl-CoA reductase kinetic parameters virtually indistinguishable from the wild type. This suggests that hydroxymethylglutaryl-CoA reductase may have been selected to be a sub-optimal substrate for AMPK.
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Affiliation(s)
- Y P Ching
- Department of Biochemistry, The University, Dundee, Scotland
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29
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Davies SP, Helps NR, Cohen PT, Hardie DG. 5'-AMP inhibits dephosphorylation, as well as promoting phosphorylation, of the AMP-activated protein kinase. Studies using bacterially expressed human protein phosphatase-2C alpha and native bovine protein phosphatase-2AC. FEBS Lett 1995; 377:421-5. [PMID: 8549768 DOI: 10.1016/0014-5793(95)01368-7] [Citation(s) in RCA: 403] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Human protein phosphatase-2C alpha (PP2C alpha) was purified to homogeneity after expression in Escherichia coli. AMP inhibited the dephosphorylation of AMP-activated protein kinase (AMPK), but not phosphocasein, by PP2C alpha. The concentration dependence and the effects of other nucleotides (ATP and formycin A-5'-monophosphate) suggest that AMP acts by binding to the same site which causes direct allosteric activation of AMPK. A similar, although less pronounced, effect was observed with another protein phosphatase (PP2AC). We have now shown that AMPK activates the AMPK cascade by four mechanisms, which should make the system exquisitely sensitive to changes in AMP concentration.
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Affiliation(s)
- S P Davies
- Department of Biochemistry, The University, Dundee, Scotland, UK
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30
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Davies SP, Hawley SA, Woods A, Carling D, Haystead TA, Hardie DG. Purification of the AMP-activated protein kinase on ATP-gamma-sepharose and analysis of its subunit structure. Eur J Biochem 1994; 223:351-7. [PMID: 8055903 DOI: 10.1111/j.1432-1033.1994.tb19001.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The AMP-activated protein kinase has been purified by affinity chromatography on ATP-gamma-Sepharose. A proportion of the activity can be eluted using AMP, while the remainder is eluted using ATP. The AMP eluate contains three polypeptides of 63, 38 and 35 kDa (p63, p38 and p35) in a molar ratio (by Coomassie blue binding) close to 1:1:1. p63 was previously identified as the AMP-binding catalytic subunit [Carling, D., Clarke, P. R., Zammit, V. A. & Hardie, D. G. (1989) Eur. J. Biochem. 186, 129-136]. All three polypeptides exactly comigrate both on native gel electrophoresis and on gel filtration, suggesting that p38 and p35 are additional subunits. Estimation of Stokes radius (5.4-5.8 nm) by gel filtration, and sedimentation coefficient (7.9-8.4 S) by glycerol gradient centrifugation, suggest that the kinase has an asymmetric structure with a native molecular mass for the complex of 190 +/- 10 kDa. Thus the native enzyme appears to be a heterotrimer with a p63/p38/p35 (1:1:1) structure. Despite the fact that the ATP eluate has a higher specific activity than the AMP eluate (3.5 +/- 0.2 vs 2.3 +/- 0.2 mumol.min-1.mg-1), it appears to be less pure, containing p63, p38 and p35 plus other polypeptides. Experiments examining the effects of protein phosphatase-2A and kinase kinase, and analysis by Western blotting with anti-p63 antibody, suggests that the AMP eluate is entirely in the low-activity dephosphorylated form, while the ATP eluate is a mixture of that form and the high-activity phosphorylated form. As well as establishing the subunit structure of the AMP-activated protein kinase, these results suggest that the kinase can bind to ATP-gamma-Sepharose through either the allosteric (AMP/ATP) site or the catalytic (ATP) site, and that phosphorylation by the kinase kinase increases the affinity for the latter site.
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Affiliation(s)
- S P Davies
- Department of Biochemistry, The University, Dundee, Scotland
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Xu H, Davies SP, Kwan BY, O'Brien AP, Singh M, Knox RB. Haploid and diploid expression of a Brassica campestris anther-specific gene promoter in Arabidopsis and tobacco. Mol Gen Genet 1993; 239:58-65. [PMID: 8510662 DOI: 10.1007/bf00281601] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The anther-specific cDNA clone Bcp1 from Brassica campestris is expressed in both the haploid pollen and diploid tapetum, as shown by in situ hybridization. We have isolated Bgp1, a genomic clone homologous to Bcp1. The coding region and extensive 5' flanking sequences of Bgp1 have been sequenced, and the coding region shows 88% identity with Bcp1. RNA gel blot analysis confirmed the expression of Bgp1-specific transcripts in B. campestris pollen. A 767 bp 5' DNA fragment was fused to the reporter gene beta-glucuronidase (gus) and introduced into both Arabidopsis thaliana and Nicotiana tabacum by transformation. This 5' fragment directed high-level expression in the pollen and tapetum of transgenic Arabidopsis. In transgenic tobacco however, the same construct was expressed only in pollen. A series of 5' deletion constructs has been created and used to transform A. thaliana to analyse the 5' region of Bgp1. The results indicate that Bgp1 expression in the tapetum and pollen of Arabidopsis requires the presence of different 5' DNA sequences.
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Affiliation(s)
- H Xu
- School of Botany, University of Melbourne, Parkville, Victoria, Australia
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32
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Mackintosh RW, Davies SP, Clarke PR, Weekes J, Gillespie JG, Gibb BJ, Hardie DG. Evidence for a protein kinase cascade in higher plants. 3-Hydroxy-3-methylglutaryl-CoA reductase kinase. ACTA ACUST UNITED AC 1992; 209:923-31. [PMID: 1358611 DOI: 10.1111/j.1432-1033.1992.tb17364.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein phosphorylation is well established as a regulatory mechanism in higher plants, but only a handful of plant enzymes are known to be regulated in this manner, and relatively few plant protein kinases have been characterized. AMP-activated protein kinase regulates key enzymes of mammalian fatty acid, sterol and isoprenoid metabolism, including 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. We now show that there is an activity in higher plants which, by functional criteria, is a homologue of the AMP-activated protein kinase, although it is not regulated by AMP. The plant kinase inactivates mammalian HMG-CoA reductase and acetyl-CoA carboxylase, and peptide mapping suggests that it phosphorylates the same sites on these proteins as the mammalian kinase. However, with the target enzymes purified from plant sources, it inactivates HMG-CoA reductase but not acetyl-CoA carboxylase. The kinase is located in the soluble, and not the chloroplast, fraction of leaf cells, consistent with the idea that it regulates HMG-CoA reductase, and hence isoprenoid biosynthesis, in vivo. The plant kinase also appears to be part of a protein kinase cascade which has been highly conserved during evolution, since the kinase is inactivated and reactivated by mammalian protein phosphatases (2A or 2C) and mammalian kinase kinase, respectively. This contrasts with the situation for many other mammalian protein kinases involved in signal transduction, which appear to have no close homologue in higher plants. To our knowledge, this represents the first direct evidence for a protein kinase cascade in higher plants.
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Affiliation(s)
- R W Mackintosh
- Biochemistry Department, The University, Dundee, Scotland
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33
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Davies SP, Carling D, Munday MR, Hardie DG. Diurnal rhythm of phosphorylation of rat liver acetyl-CoA carboxylase by the AMP-activated protein kinase, demonstrated using freeze-clamping. Effects of high fat diets. ACTA ACUST UNITED AC 1992; 203:615-23. [PMID: 1346520 DOI: 10.1111/j.1432-1033.1992.tb16591.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
1. Acetyl-CoA carboxylase was purified to homogeneity, in the presence of protein phosphatase inhibitors, from rat liver sampled without freeze-clamping. The enzyme was in a highly phosphorylated state (4.8 mol/subunit) of low specific activity, and could be dramatically reactivated by treatment with protein phosphatase-2A. Amino acid sequencing and fast-atom-bombardment mass spectrometry showed that the enzyme was phosphorylated in Ser79, Ser1200 and Ser1215, the three sites known to be phosphorylated in cell-free assays by the AMP-activated protein kinase. 2. The inactive enzyme could also be completely reactivated using a limited treatment with trypsin, which removes the N-terminal segment containing Ser79 and reduces the phosphate content to 3.5 mol/subunit. These results strengthen previous findings that it is phosphorylation at Ser79 by the AMP-activated protein kinase that is responsible for the inactivation, and not the phosphorylation of the 220-kDa core fragment (which contains Ser1200 and Ser1215). 3. Analysis of the phosphorylation state of Ser79 in acetyl-CoA carboxylase from rat liver showed that phosphorylation occurs post mortem if freeze-clamping is not used. The higher phosphorylation observed in extracts made without freeze-clamping correlates with a large increase in AMP and decrease in ATP (presumably caused by hypoxia during removal of the liver), and with increased activity of the AMP-activated protein kinase. These results provide a rational explanation for the post mortem phosphorylation events, and re-emphasize the point that rapid cooling of cells and tissues is essential when measuring the expressed activity of acetyl-CoA carboxylase (as well as 3-hydroxy-3-methylglutaryl-CoA reductase). 4. Using the freeze-clamping procedure, the ratio of 'expressed' activity (measured in the presence of protein phosphatase inhibitors) to 'total' activity (measured after complete dephosphorylation) of rat liver acetyl-CoA carboxylase showed a marked diurnal rhythm, changing from 50% in the active form in the middle of the dark period to less than 10% active in the middle of the light period. The very low activity in the light period was associated with a high level of phosphorylation in Ser79. This diurnal rhythm is very similar to that previously described for the phosphorylation of 3-hydroxy-3-methylglutaryl-CoA reductase, another substrate for the AMP-activated protein kinase. Neither the activity of the AMP-activated protein kinase nor the content of AMP, ADP or ATP changed between the dark or light periods.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- S P Davies
- Biochemistry Department, The University, Dundee, Scotland
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Davies SP, Reaveley DA, Brown EA, Kox WJ. Amino acid clearances and daily losses in patients with acute renal failure treated by continuous arteriovenous hemodialysis. Crit Care Med 1991; 19:1510-5. [PMID: 1959370 DOI: 10.1097/00003246-199112000-00012] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [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: 12/29/2022]
Abstract
OBJECTIVE To determine daily amino acid and total protein losses in patients with acute renal failure receiving total parenteral nutrition (TPN) during treatment by continuous arteriovenous hemofiltration with hemodialysis (CAVHD). DESIGN Prospective, nonrandomized study. SETTING Patients in the ICU of a regional nephrology referral center. PATIENTS Eight clearance studies of individual amino acids were performed in six patients with acute renal failure receiving TPN. Daily nitrogen intake was 9 g (one patient), 14 g (two patients), and 18 g (three patients). The clearances of individual amino acids were measured at two dialysis flow rates to calculate daily amino acid and total proten losses. RESULTS Amino acid clearance rates ranged from 7.8 +/- 2.2 (glutamic acid) to 25.2 +/- 4.8 mL/min (3-methylhistidine) at a dialysate flow rate of 1 L/hr and from 13.6 +/- 1.7 (tryptophan) to 33.7 +/- 4.3 mL/min (3-methylhistidine) at a dialysate flow rate of 2 L/hr. These results represent daily amino acid losses of 1.5 +/- 0.4% (glutamic acid) to 111.6 +/- 16.6% (tyrosine) of the nutritional input at a dialysate flow rate of 1 L/hr and 2.1 +/- 0.6% (glutamic acid) to 145.8 +/- 17.8% (tyrosine) at a dialysate flow rate of 2 L/hr. Total losses would represent 8.9 +/- 1.2% and 12.1 +/- 2.2%, respectively, of the daily protein input. CONCLUSIONS These studies confirm that amino acid clearances are relatively high during CAVHD and daily losses should therefore be considered.
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Affiliation(s)
- S P Davies
- Department of Medicine, Westminster Medical School, London, UK
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Davies SP, Brown EA, Woodrow DF, Phillips ME, Gower PE, Mee AD. The high failure rate of OKT3 in the treatment of acute renal allograft rejection resistant to steroids with or without antithymocyte globulin. Transplantation 1991; 52:746-9. [PMID: 1926361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S P Davies
- Department of Medicine, Charing Cross and Westminster Medical School, London, England
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Davies SP, Lacey LF, Kox WJ, Brown EA. Pharmacokinetics of cefuroxime and ceftazidime in patients with acute renal failure treated by continuous arteriovenous haemodialysis. Nephrol Dial Transplant 1991; 6:971-6. [PMID: 1798597 DOI: 10.1093/ndt/6.12.971] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To determine appropriate doses of cefuroxime and ceftazidime for septic patients with acute renal failure (ARF) treated by continuous arteriovenous haemodialysis (CAVHD), we performed pharmacokinetic studies in patients receiving these antibiotics. All patients were treated by CAVHD using Hospal AN69S 0.43 m2 filters and Fresenius 1.5% peritoneal dialysis fluid at dialysate flow rates (Qd) of 1 and 2 l/h. Patients received cefuroxime 500 mg (n = 11) or 750 mg (n = 1), or ceftazidime 500 mg (n = 9) i.v. 12-hourly and all studies were done at steady-state. For cefuroxime, volume of distribution (Vdarea) was 22.8 +/- 3.5 l, terminal elimination half-life (t1/2) 12.6 +/- 2.2 h and total body clearance (TBC) 22.3 +/- 3.0 ml/min (mean +/- SEM). Mean sieving coefficient (SC) was 0.90 +/- 0.12 and filter clearances at Qd 1 and 2 l/h were 14.0 +/- 2.3 and 16.2 +/- 3.4 ml/min respectively. For ceftazidime, Vdarea was 31.1 +/- 6.5 l, t1/2 14.7 +/- 3.3 h, and TBC 24.8 +/- 0.8 ml/min. Mean SC was 0.86 +/- 0.03, and filter clearances at Qd 1 and 2 l/h 13.1 +/- 1.2 and 15.2 +/- 1.5 ml/min. Satisfactory plasma concentrations of both antibiotics were maintained in all patients during treatment. These data suggest that cefuroxime 500-750 mg and ceftazidime 500 mg 12-hourly are suitable doses for patients with ARF treated by CAVHD.
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Affiliation(s)
- S P Davies
- Charing Cross and Westminster Medical School, Charing Cross Hospital, London, UK
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37
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Davies SP, Sim AT, Hardie DG. Location and function of three sites phosphorylated on rat acetyl-CoA carboxylase by the AMP-activated protein kinase. Eur J Biochem 1990; 187:183-90. [PMID: 1967580 DOI: 10.1111/j.1432-1033.1990.tb15293.x] [Citation(s) in RCA: 204] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
1. We have sequenced two tryptic/chymotryptic peptides (TC3 and TC3a) containing a third site phosphorylated on rat acetyl-CoA carboxylase by the AMP-activated protein kinase. Comparison with the complete sequence of rat acetyl-CoA carboxylase predicted from the cDNA sequence [López-Casillas et al. (1988) Proc. Natl Acad. Sci. USA 85, 5784-5788] shows that this site corresponds to Ser1215. 2. Comparison of the cDNA sequence with previous amino acid sequence data identifies the other two sites for the AMP-activated protein kinase as Ser79 and Ser1200. A total of eight serine residues phosphorylated in vitro by six protein kinases can now be identified: six of these (Ser23, Ser25, Ser29, Ser77, Ser79 and Ser95) are clustered in the amino terminal region, while two (Ser1200 and Ser1215) are located in the central region. 3. Prior phosphorylation of Ser77 and Ser1200 by cyclic-AMP-dependent protein kinase prevents subsequent phosphorylation of Ser79 and Ser1200, but not Ser1215, by the AMP-activated protein kinase. Phosphorylation of Ser1215 under these conditions is not associated with a change in enzyme activity. 4. Limited trypsin treatment of native acetyl-CoA carboxylase selectively cleaves off the highly phosphorylated amino-terminal region containing Ser79. 5. Phosphorylation at Ser79 and Ser1200 by the AMP-activated protein kinase dramatically decreases Vmax and increases the A0.5 for citrate. Phosphorylation at Ser77 and Ser1200 by cyclic-AMP-dependent protein kinase causes more modest changes in the A0.5 for citrate and the Vmax. Dephosphorylation, or removal of the amino-terminal region containing Ser77/79 using trypsin, reverses all of these effects. 6. These results suggest that the effects of the AMP-activated protein kinase on acetyl-CoA carboxylase activity are mediated entirely by phosphorylation of Ser79, and not Ser1200 and Ser1215. The smaller effects of cyclic-AMP-dependent protein kinase are mediated by phosphorylation of Ser77.
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Affiliation(s)
- S P Davies
- Biochemistry Department, The University, Dundee, Scotland
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38
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Davies SP, Carling D, Hardie DG. Tissue distribution of the AMP-activated protein kinase, and lack of activation by cyclic-AMP-dependent protein kinase, studied using a specific and sensitive peptide assay. Eur J Biochem 1989; 186:123-8. [PMID: 2574667 DOI: 10.1111/j.1432-1033.1989.tb15185.x] [Citation(s) in RCA: 370] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. We have synthesized two peptides, one based on the exact sequence around the unique site (Ser79) for the AMP-activated protein kinase on rat acetyl-CoA carboxylase (SSMS peptide) and another in which the serine residue corresponding to the site for cyclic-AMP-dependent protein kinase (Ser77) was replaced by alanine (SAMS peptide). 2. Both peptides were phosphorylated with similar kinetics by the AMP-activated protein kinase, but only the SSMS peptide was a substrate for cyclic-AMP-dependent protein kinase. The SAMS peptide was not phosphorylated by any of five other purified protein kinases tested. 3. The Km of AMP-activated protein kinase for the SAMS peptide is higher than that for acetyl-CoA carboxylase, but the Vmax for peptide phosphorylation is 2.5 times higher than that of its parent protein. This peptide therefore gives a convenient and sensitive assay for the AMP-activated protein kinase. 4. Acetyl-CoA-carboxylase kinase and peptide kinase activities copurify through six steps from a post-mitochondrial supernatant of rat liver, showing that the SAMS peptide is a specific substrate for the AMP-activated protein kinase in this tissue. We could not demonstrate AMP-dependence of the kinase activity in crude preparations, apparently due to endogenous AMP remaining bound to the enzyme. However, 8-bromoadenosine 5-monophosphate (Br8AMP) is a partial agonist at the allosteric (AMP) site, and inhibition by 2 mM Br8AMP can be used to test that one is measuring the AMP-stimulated form of the kinase. 5. Using this approach, we have examined the kinase activity in nine different rat tissues, plus a mouse macrophage cell line, and find that there is a correlation between tissues expressing significant levels of peptide kinase activity and those active in the synthesis or storage of lipids. 6. We also use the peptide assay to show that cyclic AMP-dependent protein kinase does not activate purified AMP-activated protein kinase, and does not affect the activation of partially purified AMP-activated protein kinase by endogenous kinase kinase.
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Affiliation(s)
- S P Davies
- Department of Biochemistry, The University, Dundee, Scotland
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Abstract
Continuous arteriovenous haemodialysis (CAVHD) is a new treatment for critically ill patients with renal failure that combines convective and diffusive solute removal. The clearance of urea (14.8-22.1 ml/min) is sufficient to achieve a steady-state urea concentration of 22 mmol/l, even in patients with a high catabolic rate and cardiovascular instability. The technique is simple and does not involve the use of blood pumps or specialised staff. Initial experience in 36 critically ill patients with renal failure indicates that it is safe and reliable, with less associated morbidity than other techniques.
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Affiliation(s)
- P E Stevens
- Department of Medicine, Charing Cross Hospital, London
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Abstract
A primarily clinical trial has been undertaken to investigate and compare the use of mercury and digital thermometers in a ward situation. Both laboratory and clinical studies show that there is no significant difference in the average accuracy of the two types of thermometers, however there is a greater fluctuation of readings of temperature when using electronic thermometers. In clinical studies between 9 and 23% of repeated measurements using an electronic thermometer differ by 0.5 degrees C or more whilst the corresponding range for mercury thermometers is 0.6%. It is also shown that when making clinical measurements with mercury thermometers there is no clinical advantage in using a measurement time longer than 3 minutes.
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Loke YW, Whyte A, Davies SP. Differential expression of trophoblast-specific membrane antigens by normal and abnormal human placentae and by neoplasms of trophoblastic and non-trophoblastic origin. Int J Cancer 1980; 25:459-61. [PMID: 6154657 DOI: 10.1002/ijc.2910250406] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Using a specific antiserum to human syncytial trophoblast plasma membrane (TrPM), we have investigated the expression of these antigens on a variety of trophoblastic and non-trophoblastic tissues by a standard peroxidase/anti-peroxidase staining method. Normal placenta (first-trimester as well as full-term), placenta from tubal pregnancy and placenta accreta were all found to express TrPM antigens. However, malignant change in trophoblast neoplasms appeared to by accompanied by a loss of these antigens, with 7 out of 10 specimens of hydatidiform mole staining positively while 3 specimens of invasive mole and 7 specimens of choriocarcinoma were all negative. In contrast, a number of malignant tumours of non-trophoblastic origin such as carcinomas of the colon, cervix, bladder and hepatomas were found to express TrPM antigens. The possible significance of the reversal to a trophoblast phenotype by malignant neoplasms of non-trophoblastic origin is discussed.
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