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Vaikunthanathan T, Landmann E, Correa DM, Romano M, Trevelin SC, Peng Q, Crespo E, Corrado M, Lozano JJ, Pearce EL, Perpinan E, Zoccarato A, Siew L, Edwards-Hicks J, Khan R, Luu NT, Thursz MR, Newsome PN, Martinez-Llordella M, Shah N, Lechler RI, Shah AM, Sanchez-Fueyo A, Lombardi G, Safinia N. Dysregulated anti-oxidant signalling and compromised mitochondrial integrity negatively influence regulatory T cell function and viability in liver disease. EBioMedicine 2023; 95:104778. [PMID: 37657135 PMCID: PMC10480539 DOI: 10.1016/j.ebiom.2023.104778] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [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: 03/07/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Dysregulated inflammatory responses and oxidative stress are key pathogenic drivers of chronic inflammatory diseases such as liver cirrhosis (LC). Regulatory T cells (Tregs) are essential to prevent excessive immune activation and maintain tissue homeostasis. While inflammatory cues are well known to modulate the function and stability of Tregs, the extent to which Tregs are influenced by oxidative stress has not been fully explored. METHODS The phenotypic and functional properties of CD4+CD25+CD127lo/- Tregs isolated from patients with LC were compared to healthy controls (HC). Treg redox state was investigated by characterizing intracellular reactive oxygen species (ROS), NADPH oxidase-2 (Nox2) activity, mitochondrial function, morphology, and nuclear factor-erythroid 2-related factor (Nrf2) antioxidant signalling. The relevance of Nrf2 and its downstream target, Heme-oxygenase-1 (HO-1), in Treg function, stability, and survival, was further assessed using mouse models and CRISPR/Cas9-mediated HO-1 knock-out. FINDINGS Circulating Tregs from LC patients displayed a reduced suppressive function, correlating with liver disease severity, associated with phenotypic abnormalities and increased apoptosis. Mechanistically, this was linked to a dysregulated Nrf2 signalling with resultant lower levels of HO-1, enhanced Nox2 activation, and impaired mitochondrial respiration and integrity. The functional deficit in LC Tregs could be partially recapitulated by culturing control Tregs in patient sera. INTERPRETATION Our findings reveal that Tregs rely on functional redox homeostasis for their function, stability, and survival. Targeting Treg specific anti-oxidant pathways may have therapeutic potential to reverse the Treg impairment in conditions of oxidative damage such as advanced liver disease. FUNDING This study was funded by the Wellcome Trust (211113/A/18/Z).
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Affiliation(s)
- Trishan Vaikunthanathan
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Emmanuelle Landmann
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Diana Marin Correa
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Marco Romano
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, 5th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom.
| | - Silvia Cellone Trevelin
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Qi Peng
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, 5th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom.
| | - Elena Crespo
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Mauro Corrado
- Bloomberg-Kimmel Institute for Cancer Immunotherapy and Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Juan-José Lozano
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Joseph Stelzmannstrasse 26, 50931, Cologne, Germany.
| | - Erika L Pearce
- Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBEREHD), Calle Rossello 153 Bajos, O8036, Barcelona, Spain.
| | - Elena Perpinan
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Anna Zoccarato
- Department of Immunometabolism, Max Planck Institute of Immunobiology & Epigenetics, Stübeweg 51, 79108, Freiburg, Germany.
| | - Leonard Siew
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, 5th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom.
| | - Joy Edwards-Hicks
- Centre for Liver and Gastroenterology Research and Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.
| | - Reenam Khan
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, Liver Unit, 10th Floor QEQM Building, St Mary's Hospital, W2 1NY, London, United Kingdom.
| | - Nguyet-Thin Luu
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, Liver Unit, 10th Floor QEQM Building, St Mary's Hospital, W2 1NY, London, United Kingdom.
| | - Mark R Thursz
- Institute of Liver Sciences, King's College Hospital NHS Foundation Trust, London, SE5 9NU, United Kingdom.
| | - Philip N Newsome
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, Liver Unit, 10th Floor QEQM Building, St Mary's Hospital, W2 1NY, London, United Kingdom.
| | - Marc Martinez-Llordella
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Naina Shah
- James Black Centre, Department of Cardiovascular sciences, British Heart Foundation Centre of Excellence, School of Cardiovascular and Metabolic Medicine and Sciences, King's College London, London, SE5 9NU, United Kingdom.
| | - Robert I Lechler
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, 5th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom.
| | - Ajay M Shah
- Department of Immunometabolism, Max Planck Institute of Immunobiology & Epigenetics, Stübeweg 51, 79108, Freiburg, Germany.
| | - Alberto Sanchez-Fueyo
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
| | - Giovanna Lombardi
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King's College London, 5th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom.
| | - Niloufar Safinia
- Department of Inflammation Biology, Institute of Liver Studies, School of Immunology and Microbial Sciences, James Black Centre, King's College London, London, SE5 9NU, United Kingdom.
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Sheriff L, Khan RS, Saborano R, Wilkin R, Luu NT, Gunther UL, Hubscher SG, Newsome PN, Lalor PF. Alcoholic hepatitis and metabolic disturbance in female mice: a more tractable model than Nrf2-/- animals. Dis Model Mech 2020; 13:dmm046383. [PMID: 33067186 PMCID: PMC7790192 DOI: 10.1242/dmm.046383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 06/29/2020] [Accepted: 10/07/2020] [Indexed: 12/20/2022] Open
Abstract
Alcoholic hepatitis (AH) is the dramatic acute presentation of alcoholic liver disease, with a 15% mortality rate within 28 days in severe cases. Research into AH has been hampered by the lack of effective and reproducible murine models that can be operated under different regulatory frameworks internationally. The liquid Lieber-deCarli (LdC) diet has been used as a means of ad libitum delivery of alcohol but without any additional insult, and is associated with relatively mild liver injury. The transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) protects against oxidative stress, and mice deficient in this molecule are suggested to be more sensitive to alcohol-induced injury. We have established a novel model of AH in mice and compared the nature of liver injury in C57/BL6 wild-type (WT) versus Nrf2-/- mice. Our data showed that both WT and Nrf2-/- mice demonstrate robust weight loss, and an increase in serum transaminase, steatosis and hepatic inflammation when exposed to diet and ethanol. This is accompanied by an increase in peripheral blood and hepatic myeloid cell populations, fibrogenic response and compensatory hepatocyte regeneration. We also noted characteristic disturbances in hepatic carbohydrate and lipid metabolism. Importantly, use of Nrf2-/- mice did not increase hepatic injury responses in our hands, and female WT mice exhibited a more-reproducible response. Thus, we have demonstrated that this simple murine model of AH can be used to induce an injury that recreates many of the key human features of AH - without the need for challenging surgical procedures to administer ethanol. This will be valuable for understanding of the pathogenesis of AH, for testing new therapeutic treatments or devising metabolic approaches to manage patients whilst in medical care.This article has an associated First Person interview with the joint first authors of the paper.
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Affiliation(s)
- Lozan Sheriff
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Reenam S Khan
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Raquel Saborano
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Richard Wilkin
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Nguyet-Thin Luu
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Ulrich L Gunther
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Institute of Chemistry and Metabolomics, University of Lübeck, 23562 Lübeck, Germany
| | - Stefan G Hubscher
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Liver Unit, University Hospitals Birmingham, Birmingham B15 2TH, UK
- Department of Cellular Pathology, University Hospitals Birmingham, Birmingham B15 2TH, UK
| | - Philip N Newsome
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Patricia F Lalor
- Centre for Liver and Gastroenterology Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
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3
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Ramachandran P, Dobie R, Wilson-Kanamori JR, Dora EF, Henderson BEP, Luu NT, Portman JR, Matchett KP, Brice M, Marwick JA, Taylor RS, Efremova M, Vento-Tormo R, Carragher NO, Kendall TJ, Fallowfield JA, Harrison EM, Mole DJ, Wigmore SJ, Newsome PN, Weston CJ, Iredale JP, Tacke F, Pollard JW, Ponting CP, Marioni JC, Teichmann SA, Henderson NC. Resolving the fibrotic niche of human liver cirrhosis at single-cell level. Nature 2019; 575:512-518. [PMID: 31597160 PMCID: PMC6876711 DOI: 10.1038/s41586-019-1631-3] [Citation(s) in RCA: 786] [Impact Index Per Article: 157.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 09/04/2019] [Indexed: 12/13/2022]
Abstract
Liver cirrhosis is a major cause of death worldwide and is characterized by extensive fibrosis. There are currently no effective antifibrotic therapies available. To obtain a better understanding of the cellular and molecular mechanisms involved in disease pathogenesis and enable the discovery of therapeutic targets, here we profile the transcriptomes of more than 100,000 single human cells, yielding molecular definitions for non-parenchymal cell types that are found in healthy and cirrhotic human liver. We identify a scar-associated TREM2+CD9+ subpopulation of macrophages, which expands in liver fibrosis, differentiates from circulating monocytes and is pro-fibrogenic. We also define ACKR1+ and PLVAP+ endothelial cells that expand in cirrhosis, are topographically restricted to the fibrotic niche and enhance the transmigration of leucocytes. Multi-lineage modelling of ligand and receptor interactions between the scar-associated macrophages, endothelial cells and PDGFRα+ collagen-producing mesenchymal cells reveals intra-scar activity of several pro-fibrogenic pathways including TNFRSF12A, PDGFR and NOTCH signalling. Our work dissects unanticipated aspects of the cellular and molecular basis of human organ fibrosis at a single-cell level, and provides a conceptual framework for the discovery of rational therapeutic targets in liver cirrhosis.
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Affiliation(s)
- P Ramachandran
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK.
| | - R Dobie
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - J R Wilson-Kanamori
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - E F Dora
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - B E P Henderson
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - N T Luu
- NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - J R Portman
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - K P Matchett
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - M Brice
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - J A Marwick
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, UK
| | - R S Taylor
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - M Efremova
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - R Vento-Tormo
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - N O Carragher
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, UK
| | - T J Kendall
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
- Division of Pathology, University of Edinburgh, Edinburgh, UK
| | - J A Fallowfield
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
| | - E M Harrison
- Clinical Surgery, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - D J Mole
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
- Clinical Surgery, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - S J Wigmore
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK
- Clinical Surgery, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - P N Newsome
- NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - C J Weston
- NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - J P Iredale
- Office of the Vice Chancellor, Beacon House and National Institute for Health Research, Biomedical Research Centre, Bristol, UK
| | - F Tacke
- Department of Hepatology and Gastroenterology, Charité University Medical Center, Berlin, Germany
| | - J W Pollard
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - C P Ponting
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, UK
| | - J C Marioni
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - S A Teichmann
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
- Theory of Condensed Matter Group, The Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - N C Henderson
- University of Edinburgh Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK.
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4
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Rashidi H, Luu NT, Alwahsh SM, Ginai M, Alhaque S, Dong H, Tomaz RA, Vernay B, Vigneswara V, Hallett JM, Chandrashekran A, Dhawan A, Vallier L, Bradley M, Callanan A, Forbes SJ, Newsome PN, Hay DC. 3D human liver tissue from pluripotent stem cells displays stable phenotype in vitro and supports compromised liver function in vivo. Arch Toxicol 2018; 92:3117-3129. [PMID: 30155720 PMCID: PMC6132688 DOI: 10.1007/s00204-018-2280-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [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: 06/23/2018] [Accepted: 07/31/2018] [Indexed: 12/15/2022]
Abstract
Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to the shortage of donor organs. Developing renewable sources of human liver tissue is therefore attractive. Pluripotent stem cell-derived liver tissue represents a potential alternative to cadaver derived hepatocytes and whole organ transplant. At present, two-dimensional differentiation procedures deliver tissue lacking certain functions and long-term stability. Efforts to overcome these limiting factors have led to the building of three-dimensional (3D) cellular aggregates. Although enabling for the field, their widespread application is limited due to their reliance on variable biological components. Our studies focused on the development of 3D liver tissue under defined conditions. In vitro generated 3D tissues exhibited stable phenotype for over 1 year in culture, providing an attractive resource for long-term in vitro studies. Moreover, 3D derived tissue provided critical liver support in two animal models, including immunocompetent recipients. Therefore, we believe that our study provides stable human tissue to better model liver biology 'in the dish', and in the future may permit the support of compromised liver function in humans.
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Affiliation(s)
- Hassan Rashidi
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Nguyet-Thin Luu
- Centre for Liver Research, Institute of Immunology and Immunotherapy and National Institute for Health Research Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham, Birmingham, UK
| | - Salamah M Alwahsh
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Maaria Ginai
- Institute of Bioengineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK
| | - Sharmin Alhaque
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Hua Dong
- School of Chemistry, University of Edinburgh, Kings Buildings, EH9 3FJ, Edinburgh, UK
| | - Rute A Tomaz
- Anne McLaren Laboratory, Wellcome Trust-MRC Stem Cell Institute, University of Cambridge, Cambridge, CB2 0SZ, UK
| | - Bertrand Vernay
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Vasanthy Vigneswara
- Centre for Liver Research, Institute of Immunology and Immunotherapy and National Institute for Health Research Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham, Birmingham, UK
| | - John M Hallett
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Anil Chandrashekran
- Child Health Clinical Academic Group, MRC Centre for Transplantation, King's College London, London, UK
| | - Anil Dhawan
- Child Health Clinical Academic Group, MRC Centre for Transplantation, King's College London, London, UK
| | - Ludovic Vallier
- Anne McLaren Laboratory, Wellcome Trust-MRC Stem Cell Institute, University of Cambridge, Cambridge, CB2 0SZ, UK
| | - Mark Bradley
- School of Chemistry, University of Edinburgh, Kings Buildings, EH9 3FJ, Edinburgh, UK
| | - Anthony Callanan
- Institute of Bioengineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK
| | - Stuart J Forbes
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Philip N Newsome
- Centre for Liver Research, Institute of Immunology and Immunotherapy and National Institute for Health Research Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham, Birmingham, UK.,Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - David C Hay
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK.
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5
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Munir H, Luu NT, Clarke LSC, Nash GB, McGettrick HM. Comparative Ability of Mesenchymal Stromal Cells from Different Tissues to Limit Neutrophil Recruitment to Inflamed Endothelium. PLoS One 2016; 11:e0155161. [PMID: 27171357 PMCID: PMC4865100 DOI: 10.1371/journal.pone.0155161] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/25/2016] [Indexed: 12/17/2022] Open
Abstract
Mesenchymal stromal cells (MSC) are tissue-resident stromal cells capable of modulating immune responses, including leukocyte recruitment by endothelial cells (EC). However, the comparative potency of MSC from different sources in suppressing recruitment, and the necessity for close contact with endothelium remain uncertain, although these factors have implications for use of MSC in therapy. We thus compared the effects of MSC isolated from bone marrow, Wharton's jelly, and trabecular bone on neutrophil recruitment to cytokine-stimulated EC, using co-culture models with different degrees of proximity between MSC and EC. All types of MSC suppressed neutrophil adhesion to inflamed endothelium but not neutrophil transmigration, whether directly incorporated into endothelial monolayers or separated from them by thin micropore filters. Further increase in the separation of the two cell types tended to reduce efficacy, although this diminution was least for the bone marrow MSC. Immuno-protective effects of MSC were also diminished with repeated passage; with BMMSC, but not WJMSC, completing losing their suppressive effect by passage 7. Conditioned media from all co-cultures suppressed neutrophil recruitment, and IL-6 was identified as a common bioactive mediator. These results suggest endogenous MSC have a homeostatic role in limiting inflammatory leukocyte infiltration in a range of tissues. Since released soluble mediators might have effects locally or remotely, infusion of MSC into blood or direct injection into target organs might be efficacious, but in either case, cross-talk between EC and MSC appears necessary.
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Affiliation(s)
- Hafsa Munir
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Nguyet-Thin Luu
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Lewis S. C. Clarke
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Gerard B. Nash
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Helen M. McGettrick
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
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6
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Mura M, Zhuang X, Vorschmitt H, Swain RK, Durant S, Herbert JM, Sheldon H, Andre M, Sanderson S, Reynolds G, Glen K, Luu NT, McGettrick H, Antczak P, Falciani F, Nash G, Nagy Z, Bicknell R. Abstract 1589: Low shear stress induces the novel tumor endothelial marker CLEC14A that mediates cell migration and vascular development. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-1589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Experimental evidence using animal models has proven the efficacy of targeting a tumor endothelial marker (TEM) in eradicating large solid tumours. It follows that a well characterised tumor endothelial marker would offer much promise as an anti-cancer target. Despite many efforts by numerous groups, a well defined tumor endothelial marker in man has remained elusive. CLEC14A is a novel endothelial specific C-type lectin that is a member of the endosialin/TEM1 and thrombomodulin family of lectins. Protein sequence alignment of CLEC14A shows conservation from fish to man and endothelial specificity of expression is seen in the embryonic zebrafish. Detailed analysis of CLEC14A expression using human tissue arrays showed that CLEC14A is absent in human adult tissue but highly expressed in endothelium across a wide range of tumour tissues. CLEC14A is a superior tumor endothelial marker to Robo4 in terms of specificity and level of expression on the cell surface. CLEC14A is only expressed by endothelium in the absence of shear stress and this could explain its tumor specific expression due to poor blood flow in ill-formed tumor vessels. Functional studies have shown that CLEC14A is present on filopodia and mediates endothelial cell migration and tube formation. Anti-sera to CLEC14A similarly inhibited these processes suggesting that anti-CLEC14A monoclonal antibodies would have anti-angiogenic activity. The expression profile of CLEC14A, its cell surface localisation and inhibition of pro-angiogenic activities by anti-sera make CLEC14A a uniquely interesting target.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1589.
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Affiliation(s)
- Manuela Mura
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Xiadong Zhuang
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Henrik Vorschmitt
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Rajeeb K. Swain
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Sarah Durant
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - John M. Herbert
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Helen Sheldon
- 2Univ. of Oxford Inst of Molecular Medicine, Oxford, United Kingdom
| | - Maud Andre
- 2Univ. of Oxford Inst of Molecular Medicine, Oxford, United Kingdom
| | - Sharon Sanderson
- 2Univ. of Oxford Inst of Molecular Medicine, Oxford, United Kingdom
| | - Gary Reynolds
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Katie Glen
- 3Univ. of Queensland Inst of Molecular Medicine, Brisbarne, Australia
| | - Nguyet-Thin Luu
- 4Univ. of Birmingham Center for Cardiovascular Science, Birmingham, United Kingdom
| | - Helen McGettrick
- 4Univ. of Birmingham Center for Cardiovascular Science, Birmingham, United Kingdom
| | - Phillip Antczak
- 5Univ. of Birmingham School of Bioscience, Birmingham, United Kingdom
| | | | - Gerard Nash
- 4Univ. of Birmingham Center for Cardiovascular Science, Birmingham, United Kingdom
| | - Zsuzsanna Nagy
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
| | - Roy Bicknell
- 1Univ. of Birmingham Inst. of Biomed. Res., Birmingham, United Kingdom
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Luu NT, Madden J, Calder PC, Grimble RF, Shearman CP, Chan T, Dastur N, Howell WM, Rainger GE, Nash GB. Dietary supplementation with fish oil modifies the ability of human monocytes to induce an inflammatory response. J Nutr 2007; 137:2769-74. [PMID: 18029497 DOI: 10.1093/jn/137.12.2769] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Monocytes/macrophages are key orchestrators of inflammation and are involved in the pathogenesis of chronic inflammatory disorders, including atherosclerosis. (n-3) Fatty acids, found in fish oil, have been shown to have protective effects in such disorders. To investigate possible modes of action, we used a monocyte:endothelial cell (EC) coculture model to investigate the pro-inflammatory potential of monocytes. Monocytes were isolated from the blood of donors with peripheral arterial disease (PAD) or control donors, before and after a 12-wk supplementation of their diet with fish oil. The monocytes were cultured with human umbilical vein EC (HUVEC) for 24 h, after which the ability of the HUVEC to recruit flowing neutrophils was tested. Monocytes from either group of donors stimulated the EC to support the adhesion and migration of neutrophils. Fish oil supplementation reduced the potency of monocytes from normal subjects, but not those from patients with PAD, to induce recruitment. Concurrent medication may have acted as a complicating factor. On subgroup analysis, only those free of medication showed a significant effect of fish oil. Responses before or after supplementation were not closely linked to patterns of secretion of cytokines by cultured monocytes, tested in parallel monocultures. These results suggest that fish oil can modulate the ability of monocytes to stimulate EC and that this might contribute to their protective effects against chronic inflammatory disorders. Benefits, however, may depend on existing medical status and on other treatments being received.
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Affiliation(s)
- Nguyet-Thin Luu
- Centre for Cardiovascular Sciences, Department of Physiology, The Medical School, University of Birmingham, Birmingham, B15 2TT, UK
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8
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Luu NT, Madden J, Calder PC, Grimble RF, Shearman CP, Chan T, Tull SP, Dastur N, Rainger GE, Nash GB. Comparison of the pro-inflammatory potential of monocytes from healthy adults and those with peripheral arterial disease using an in vitro culture model. Atherosclerosis 2007; 193:259-68. [PMID: 16982061 DOI: 10.1016/j.atherosclerosis.2006.08.050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 08/16/2006] [Accepted: 08/24/2006] [Indexed: 10/24/2022]
Abstract
We adapted a monocyte:endothelial cell co-culture model to investigate the pro-inflammatory potential of monocytes from patients with peripheral arterial disease (PAD). Isolated monocytes were cultured with human umbilical vein endothelial cells (HUVEC) for 24h, after which the ability of the HUVEC to recruit flowing neutrophils was tested. Development of a usable protocol required comparisons of primary HUVEC with cells that had been passaged and/or frozen and thawed, evaluation of optimal culture media and comparison of monocytes from freshly drawn and stored blood. We found, for instance, that expansion of HUVEC was assisted by inclusion of hydrocortisone, but this agent was withdrawn before the test phase because it reduced responses of HUVEC. Using the optimal practical protocol, we found great variation in the ability of monocytes from different donors to cause neutrophil adhesion. Slightly more ( approximately 20%) monocytes from patients with PAD adhered to HUVEC than monocytes from healthy controls, and the monocytes from PAD patients induced approximately 70% greater subsequent adhesion of neutrophils. Thus, we developed a functional model of inflammatory potential usable in clinically-related studies and found that patients with PAD had circulating monocytes with greater than normal ability to activate endothelial cells.
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Affiliation(s)
- N T Luu
- Centre for Cardiovascular Sciences, Department of Physiology, Medical School, The University of Birmingham, Birmingham B15 2TT, UK
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Radford DJ, Luu NT, Hewins P, Nash GB, Savage CO. Antineutrophil cytoplasmic antibodies stabilize adhesion and promote migration of flowing neutrophils on endothelial cells. Arthritis Rheum 2001; 44:2851-61. [PMID: 11762946 DOI: 10.1002/1529-0131(200112)44:12<2851::aid-art473>3.0.co;2-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Recruitment of neutrophils to sites of inflammation requires coordinated regulation of their capture, activation, and migration on vascular endothelium. This study examines whether exposure of neutrophils to antineutrophil cytoplasmic antibodies (ANCAs) can disrupt this sequence of events. METHODS Isolated human neutrophils were perfused in the presence or absence of ANCA-positive IgG over endothelial cells that had been activated with either 2 units/ml or 100 units/ml of tumor necrosis factor alpha (TNFalpha) for 4 hours. RESULTS When endothelial cells were activated with 100 units/ml of TNFalpha, neutrophils were captured from flow, a small proportion of adherent cells rolled, and the majority transmigrated through the endothelial cell monolayer. When neutrophils were treated with ANCA IgG immediately before, 5 minutes before, or 15 minutes before perfusion, none rolled on contact with the endothelium, but the majority still transmigrated. When endothelial cells were activated with 2 units/ml of TNFalpha, the majority of untreated adherent neutrophils rolled, a few transmigrated, and the number that attached decreased with time during washout. In contrast, when neutrophils were pretreated with ANCA IgG just before perfusion, adhesion was stabilized, and the number of neutrophils that transmigrated was increased 10-fold. Priming of the neutrophils with TNFalpha before the addition of ANCA further increased the stability of neutrophil binding, but did not significantly increase transmigration. CONCLUSION Rather than frustrating the transmigration process, ANCAs promoted the migration of neutrophils through the endothelium. That the effect was evident at a relatively low level of endothelial activation suggests that ANCAs may potentiate the early vasculitic lesion and promote tissue damage and recruitment of other proinflammatory cells.
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Affiliation(s)
- D J Radford
- The Medical School, The University of Birmingham, UK
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Luu NT, Rainger GE, Nash GB. Differential ability of exogenous chemotactic agents to disrupt transendothelial migration of flowing neutrophils. J Immunol 2000; 164:5961-9. [PMID: 10820279 DOI: 10.4049/jimmunol.164.11.5961] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neutrophils migrate through endothelium using an ordered sequence of adhesive interactions and activating signals. To investigate the consequences of disruption of this sequence, we characterized adhesion and migration of neutrophils perfused over HUVEC that had been treated with TNF-alpha for 4 h and evaluated changes caused by exogenously added chemotactic agents. When HUVEC were treated with 2 U/ml TNF, flowing neutrophils adhered, with the majority rolling and relatively few migrating through the monolayer. If fMLP, IL-8, zymosan-activated plasma (a source of activated complement factor C5a), epithelial cell-derived neutrophil-activating peptide (ENA-78), or growth-regulating oncogene, GRO-alpha, was perfused over these neutrophils, they stopped rolling and rapidly migrated over the monolayer, but did not penetrate it. When HUVEC were treated with 100 U/ml TNF, the majority of adherent neutrophils transmigrated. If neutrophils were treated with fMLP, IL-8, C5a, ENA-78, or GRO-alpha just before perfusion over this HUVEC, transmigration, but not adhesion, was abolished. However, when platelet-activating factor was used to activate neutrophils, migration through HUVEC treated with 100 U/ml TNF was not impaired, and migration through HUVEC treated with 2 U/ml TNF was actually increased. Transmigration required ligation of CXC chemokine receptor-2 on neutrophils, and differential desensitization of this receptor (e.g., by fMLP but not platelet-activating factor) may explain the pattern of disruption of migration. Thus, transmigration may require presentation of the correct activators in the correct sequence, and inappropriate activation (e.g., by systemic activators) could cause pathological accumulation of neutrophils in the vessel lumen.
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MESH Headings
- Cell Adhesion/immunology
- Cell Migration Inhibition
- Cells, Cultured
- Chemokine CXCL1
- Chemokine CXCL5
- Chemokines, CXC
- Chemotactic Factors/metabolism
- Chemotactic Factors/pharmacology
- Chemotaxis, Leukocyte/immunology
- Complement C5a/pharmacology
- Dose-Response Relationship, Immunologic
- Endothelium, Vascular/cytology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Growth Substances/pharmacology
- Humans
- Intercellular Signaling Peptides and Proteins
- Interleukin-8/analogs & derivatives
- Interleukin-8/metabolism
- Interleukin-8/pharmacology
- Interleukin-8/physiology
- N-Formylmethionine Leucyl-Phenylalanine/pharmacology
- Neutrophil Activation/immunology
- Neutrophils/immunology
- Platelet Activating Factor/pharmacology
- Receptors, Chemokine/metabolism
- Receptors, Chemokine/physiology
- Receptors, Interleukin/metabolism
- Receptors, Interleukin/physiology
- Receptors, Interleukin-8B
- Umbilical Veins
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Affiliation(s)
- N T Luu
- Department of Physiology, The Medical School, University of Birmingham, Birmingham, United Kingdom
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Luu NT, Rainger GE, Nash GB. Kinetics of the different steps during neutrophil migration through cultured endothelial monolayers treated with tumour necrosis factor-alpha. J Vasc Res 1999; 36:477-85. [PMID: 10629423 DOI: 10.1159/000025690] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
To enable a better understanding of the regulation of neutrophil migration, we investigated the kinetics of adhesion and migration over, through and under endothelial monolayers. Neutrophils were perfused over human umbilical vein endothelial cells (HUVEC) which had been treated with tumour necrosis factor-alpha (TNF; 2-1,000 U/ml) for 4 h. Videomicroscopy showed that transendothelial migration was complete within about 5 min of completion of perfusion of a bolus of neutrophils. Separate populations of adherent cells could then be observed, either rolling, migrating over the surface of the HUVEC or migrating underneath, at different characteristic speeds. Increasing concentration of TNF had little effect on the kinetics of migration, but shifted the balance from rolling adhesion to transendothelial migration. When individual neutrophils were followed from the moment they bound to HUVEC treated with 100 U/ml TNF, we found that approximately 40% immobilised essentially immediately on contact, while approximately 40% immobilised after rolling for varying periods (average 26 s) and approximately 20% rolled continuously. Most of the immobilised cells went on to migrate through the monolayer after spending 20-200 s migrating on top, and took about 60 s to pass through. Overall, the time from first binding to completion of transmigration averaged 152 s (range approximately 60-240 s). Interestingly, neutrophils moved relatively slowly on top of the monolayer (about 8 microm/min) but more rapidly underneath (about 16 microm/min). We suggest that the different stages during neutrophil transmigration have characteristic kinetics with separate control mechanisms, which critically influence the efficiency and rate of clearance from the vasculature.
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Affiliation(s)
- N T Luu
- Department of Physiology, The Medical School, The University of Birmingham, Birmingham, UK
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Johnson SA, Luu NT, Herbst TA, Knapp R, Lutz D, Arai A, Rogers GA, Lynch G. Synergistic interactions between ampakines and antipsychotic drugs. J Pharmacol Exp Ther 1999; 289:392-7. [PMID: 10087029] [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: 02/11/2023] Open
Abstract
Tests were made for interactions between antipsychotic drugs and compounds that enhance synaptic currents mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid-type glutamate receptors ("ampakines"). Typical and atypical antipsychotic drugs decreased methamphetamine-induced hyperactivity in rats; the effects of near or even subthreshold doses of the antipsychotics were greatly enhanced by the ampakines. Interactions between the ampakine CX516 and low doses of different antipsychotics were generally additive and often synergistic. The ampakine did not exacerbate neuroleptic-induced catalepsy, indicating that the interaction between the different pharmacological classes was selective. These results suggest that positive modulators of cortical glutamatergic systems may be useful adjuncts in treating schizophrenia.
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Affiliation(s)
- S A Johnson
- Cortex Pharmaceuticals, Incorporated, Irvine, California, USA
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Bhalla DK, Daniels DS, Luu NT. Attenuation of ozone-induced airway permeability in rats by pretreatment with cyclophosphamide, FPL 55712, and indomethacin. Am J Respir Cell Mol Biol 1992; 7:73-80. [PMID: 1320904 DOI: 10.1165/ajrcmb/7.1.73] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Exposure of rats to ozone (O3) produces an increase in airway permeability and a concomitant influx of polymorphonuclear leukocytes in the lung. These observations raise the possibility that the inflammatory cells play a role in the cellular injury and increased airway permeability after O3 exposure. This study was therefore designed to determine if the inflammatory cells or their products are essential for the O3 effect. In a series of experiments, rats were rendered leukopenic with cyclophosphamide, treated with leukotriene B4 (LTB4), or with the inhibitors of lipoxygenase or cyclooxygenase products of arachidonic acid, followed by exposure to O3. A 2-h exposure to 0.8 ppm O3 caused a significant increase in the flux of proteins and albumin in bronchoalveolar lavage (BAL) and elevated the transport of 99mTc-diethylenetriaminepentaacetate (99mTc-DTPA) from trachea to blood. The treatment with cyclophosphamide caused a significant reduction in the circulating and pulmonary leukocytes and prevented an increase in tracheal mucosal permeability to 99mTc-DTPA and the protein and albumin flux in BAL. While the intratracheal instillation of LTB4 did not affect the permeability, tracheal permeability and albumin levels in BAL in rats treated with LTD4 antagonist FPL 55712 and exposed to O3 were lower than in the untreated O3-exposed rats. Pretreatment with indomethacin also prevented the O3 effects, as reflected by the decreased protein and albumin flux in BAL and 99mTc-DTPA transport from trachea to blood. These data show a reduction in the effect of O3 by agents that affect leukocytes or their products. The results support a mechanism of increased permeability that is dependent upon inflammatory cells and their products.
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Affiliation(s)
- D K Bhalla
- Community and Environmental Medicine, University of California, Irvine 92717
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