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Zimmerman E, Sturrock A, Reilly CA, Burrell-Gerbers KL, Warren K, Mir-Kasimov M, Zhang MA, Pierce MS, Helms MN, Paine R. Aryl Hydrocarbon Receptor Activation in Pulmonary Alveolar Epithelial Cells Limits Inflammation and Preserves Lung Epithelial Cell Integrity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 213:600-611. [PMID: 39033086 PMCID: PMC11335325 DOI: 10.4049/jimmunol.2300325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/17/2024] [Indexed: 07/23/2024]
Abstract
The aryl hydrocarbon receptor (AHR) is a receptor/transcription factor widely expressed in the lung. The physiological roles of AHR expressed in the alveolar epithelium remain unclear. In this study, we tested the hypothesis that alveolar epithelial AHR activity plays an important role in modulating inflammatory responses and maintaining alveolar integrity during lung injury and repair. AHR is expressed in alveolar epithelial cells (AECs) and is active. AHR activation with the endogenous AHR ligand, FICZ (5,11-dihydroindolo[3,2-b] carbazole-6-carboxaldehyde), significantly suppressed inflammatory cytokine expression in response to inflammatory stimuli in primary murine AECs and in the MLE-15 epithelial cell line. In an LPS model of acute lung injury in mice, coadministration of FICZ with LPS suppressed protein leak, reduced neutrophil accumulation in BAL fluid, and suppressed inflammatory cytokine expression in lung tissue and BAL fluid. Relevant to healing following inflammatory injury, AHR activation suppressed TGF-β-induced expression of genes associated with epithelial-mesenchymal transition. Knockdown of AHR in primary AECs with shRNA or in CRISPR-Cas-9-induced MLE-15 cells resulted in upregulation of α-smooth muscle actin (αSma), Col1a1, and Fn1 and reduced expression of epithelial genes Col4a1 and Sdc1. MLE-15 clones lacking AHR demonstrated accelerated wound closure in a scratch model. AHR activation with FICZ enhanced barrier function (transepithelial electrical resistance) in primary murine AECs and limited decline of transepithelial electrical resistance following inflammatory injury. AHR activation in AECs preserves alveolar integrity by modulating inflammatory cytokine expression while enhancing barrier function and limiting stress-induced expression of mesenchymal genes.
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Affiliation(s)
- Elizabeth Zimmerman
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
| | - Anne Sturrock
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT
| | - Christopher A. Reilly
- Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT
| | | | - Kristi Warren
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT
| | - Mustafa Mir-Kasimov
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT
| | - Mingyang A. Zhang
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
| | - Megan S. Pierce
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
| | - My N. Helms
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
| | - Robert Paine
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, UT
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT
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Bosteels C, Van Damme KFA, De Leeuw E, Declercq J, Maes B, Bosteels V, Hoste L, Naesens L, Debeuf N, Deckers J, Cole B, Pardons M, Weiskopf D, Sette A, Weygaerde YV, Malfait T, Vandecasteele SJ, Demedts IK, Slabbynck H, Allard S, Depuydt P, Van Braeckel E, De Clercq J, Martens L, Dupont S, Seurinck R, Vandamme N, Haerynck F, Roychowdhury DF, Vandekerckhove L, Guilliams M, Tavernier SJ, Lambrecht BN. Loss of GM-CSF-dependent instruction of alveolar macrophages in COVID-19 provides a rationale for inhaled GM-CSF treatment. Cell Rep Med 2022; 3:100833. [PMID: 36459994 PMCID: PMC9663750 DOI: 10.1016/j.xcrm.2022.100833] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/12/2022] [Accepted: 11/08/2022] [Indexed: 11/17/2022]
Abstract
GM-CSF promotes myelopoiesis and inflammation, and GM-CSF blockade is being evaluated as a treatment for COVID-19-associated hyperinflammation. Alveolar GM-CSF is, however, required for monocytes to differentiate into alveolar macrophages (AMs) that control alveolar homeostasis. By mapping cross-species AM development to clinical lung samples, we discovered that COVID-19 is marked by defective GM-CSF-dependent AM instruction and accumulation of pro-inflammatory macrophages. In a multi-center, open-label RCT in 81 non-ventilated COVID-19 patients with respiratory failure, we found that inhalation of rhu-GM-CSF did not improve mean oxygenation parameters compared with standard treatment. However, more patients on GM-CSF had a clinical response, and GM-CSF inhalation induced higher numbers of virus-specific CD8 effector lymphocytes and class-switched B cells, without exacerbating systemic hyperinflammation. This translational proof-of-concept study provides a rationale for further testing of inhaled GM-CSF as a non-invasive treatment to improve alveolar gas exchange and simultaneously boost antiviral immunity in COVID-19. This study is registered at ClinicalTrials.gov (NCT04326920) and EudraCT (2020-001254-22).
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Affiliation(s)
- Cedric Bosteels
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Karel F A Van Damme
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Elisabeth De Leeuw
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Jozefien Declercq
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Bastiaan Maes
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Victor Bosteels
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium; Laboratory of ER Stress and Inflammation, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium
| | - Levi Hoste
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Primary Immunodeficiency Research Lab, Faculty of Medicine and Health Sciences, Ghent University, Ghent 9000, Belgium
| | - Leslie Naesens
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Primary Immunodeficiency Research Lab, Faculty of Medicine and Health Sciences, Ghent University, Ghent 9000, Belgium
| | - Nincy Debeuf
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Julie Deckers
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Basiel Cole
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium
| | - Marion Pardons
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium
| | - Daniela Weiskopf
- Center for Autoimmunity and Inflammation and Center for Infectious Diseases and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Alessandro Sette
- Center for Autoimmunity and Inflammation and Center for Infectious Diseases and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA; Department of Medicine, Division of Infectious Diseases and Global Public Health, University of California, San Diego (UCSD), La Jolla, CA 92037, USA
| | | | - Thomas Malfait
- Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | | | - Ingel K Demedts
- Department of Pulmonary Medicine, AZ Delta General Hospital, 8800 Roeselare, Belgium
| | - Hans Slabbynck
- Department of Pulmonary Medicine, ZNA General Hospital, 2000 Antwerp, Belgium
| | - Sabine Allard
- Department of Internal Medicine, Universitair Ziekenhuis Brussel, 1000 Brussels, Belgium
| | - Pieter Depuydt
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Intensive Care Unit, Ghent University Hospital, 9000 Ghent, Belgium
| | - Eva Van Braeckel
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Jozefien De Clercq
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Infectious Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - Liesbet Martens
- Laboratory of Myeloid Cell Biology in Tissue Homeostasis and Regeneration, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Sam Dupont
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium
| | - Ruth Seurinck
- Data Mining and Modeling for Biomedicine, VIB-UGent Center for Inflammation Research, 9000 Ghent, Belgium; Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000 Ghent, Belgium
| | - Niels Vandamme
- Data Mining and Modeling for Biomedicine, VIB-UGent Center for Inflammation Research, 9000 Ghent, Belgium; VIB Single Cell Core, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium
| | - Filomeen Haerynck
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Primary Immunodeficiency Research Lab, Faculty of Medicine and Health Sciences, Ghent University, Ghent 9000, Belgium
| | | | - Linos Vandekerckhove
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Infectious Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - Martin Guilliams
- Laboratory of Myeloid Cell Biology in Tissue Homeostasis and Regeneration, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium
| | - Simon J Tavernier
- Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Primary Immunodeficiency Research Lab, Faculty of Medicine and Health Sciences, Ghent University, Ghent 9000, Belgium; Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium; Laboratory of Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, 9000 Ghent, Belgium
| | - Bart N Lambrecht
- Laboratory of Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent University, 9000 Ghent, Belgium; Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium; Department of Respiratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
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Sturrock A, Woller D, Freeman A, Sanders K, Paine R. Consequences of Hypoxia for the Pulmonary Alveolar Epithelial Cell Innate Immune Response. THE JOURNAL OF IMMUNOLOGY 2018; 201:3411-3420. [PMID: 30381478 DOI: 10.4049/jimmunol.1701387] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/02/2018] [Indexed: 11/19/2022]
Abstract
Pulmonary innate immune responses involve a highly regulated multicellular network to defend the enormous surface area of the lung. Disruption of these responses renders the host susceptible to pneumonia. Alveolar epithelial cells (AEC) are a critical source of innate immune molecules such as GM-CSF, which determine the functional maturation of alveolar macrophages. In many pulmonary diseases, heterogeneous ventilation leads to regional hypoxia in the lung. The effect of hypoxia on AEC innate immune function is unknown. We now report that exposure of primary murine AEC to hypoxia (1% oxygen) for 24 h results in significant suppression of key innate immune molecules, including GM-CSF, CCL2, and IL-6. This exposure did not cause toxicity but did induce stabilization of hypoxia-inducible factor 1α protein (HIF-1α) and shift to glycolytic metabolism. Focusing on GM-CSF, we found that hypoxia greatly decreased the rate of GM-CSF transcription. Hypoxia both decreased NF-κB signaling in AEC and induced chromosomal changes, resulting in decreased accessibility in the GM-CSF proximal promoter of target sequences for NF-κB binding. In mice exposed to hypoxia in vivo (12% oxygen for 2 d), lung GM-CSF protein expression was reduced. In vivo phagocytosis of fluorescent beads by alveolar macrophages was also suppressed, but this effect was reversed by treatment with GM-CSF. These studies suggest that in critically ill patients, local hypoxia may contribute to the susceptibility of poorly ventilated lung units to infection through complementary effects on several pathways, reducing AEC expression of GM-CSF and other key innate immune molecules.
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Affiliation(s)
- Anne Sturrock
- Department of Veterans Affairs Medicine Center, Salt Lake City, UT 84148; and.,Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132
| | - Diana Woller
- Department of Veterans Affairs Medicine Center, Salt Lake City, UT 84148; and.,Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132
| | - Andrew Freeman
- Department of Veterans Affairs Medicine Center, Salt Lake City, UT 84148; and.,Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132
| | - Karl Sanders
- Department of Veterans Affairs Medicine Center, Salt Lake City, UT 84148; and.,Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132
| | - Robert Paine
- Department of Veterans Affairs Medicine Center, Salt Lake City, UT 84148; and .,Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132
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4
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Hyperbaric hyperoxia alters innate immune functional properties during NASA Extreme Environment Mission Operation (NEEMO). Brain Behav Immun 2015; 50:52-57. [PMID: 26116982 DOI: 10.1016/j.bbi.2015.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Spaceflight is associated with immune dysregulation which is considered as risk factor for the performance of exploration-class missions. Among the consequences of confinement and other environmental factors of living in hostile environments, the role of different oxygen concentrations is of importance as either low (e.g. as considered for lunar or Martian habitats) or high (e.g. during extravehicular activities) can trigger immune dysfunction. The aim of this study was to investigate the impact of increased oxygen availability--generated through hyperbaricity--on innate immune functions in the course of a 14 days NEEMO mission. METHODS 6 male subjects were included into a 14 days undersea deployment at the Aquarius station (Key Largo, FL, USA). The underwater habitat is located at an operating depth of 47 ft. The 2.5 times higher atmospheric pressure in the habitat leads to hyperoxia. The collection of biological samples occurred 6 days before (L-6), at day 7 (MD7) and 11/13 (MD11/13) during the mission, and 90 days thereafter (R). Blood analyses included differential blood cell count, ex vivo innate immune activation status and inhibitory competences of granulocytes. RESULTS The absolute leukocyte count showed an increase during deployment as well as the granulocyte and monocyte count. Lymphocyte count was decreased on MD7. The assessments of native adhesion molecules on granulocytes (CD11b, CD62L) indicated a highly significant cellular activation (L-6 vs. MD7/MD13) during mission. In contrast, granulocytes were more sensitive towards anti-inflammatory stimuli (adenosine) on MD13. CONCLUSION Living in the NEEMO habitat for 14 days induced significant immune alterations as seen by an activation of adhesion molecules and vice versa higher sensitivity towards inhibition. This investigation under hyperbaric hyperoxia is important especially for Astronauts' immune competence during extravehicular activities when exposed to similar conditions.
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Domm W, Misra RS, O'Reilly MA. Affect of Early Life Oxygen Exposure on Proper Lung Development and Response to Respiratory Viral Infections. Front Med (Lausanne) 2015; 2:55. [PMID: 26322310 PMCID: PMC4530667 DOI: 10.3389/fmed.2015.00055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/27/2015] [Indexed: 12/22/2022] Open
Abstract
Children born preterm often exhibit reduced lung function and increased severity of response to respiratory viruses, suggesting that premature birth has compromised proper development of the respiratory epithelium and innate immune defenses. Increasing evidence suggests that premature birth promotes aberrant lung development likely due to the neonatal oxygen transition occurring before pulmonary development has matured. Given that preterm infants are born at a point of time where their immune system is also still developing, early life oxygen exposure may also be disrupting proper development of innate immunity. Here, we review current literature in hopes of stimulating research that enhances understanding of how the oxygen environment at birth influences lung development and host defense. This knowledge may help identify those children at risk for disease and ideally culminate in the development of novel therapies that improve their health.
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Affiliation(s)
- William Domm
- Department of Pediatrics, School of Medicine and Dentistry, The University of Rochester , Rochester, NY , USA ; Department of Environmental Medicine, School of Medicine and Dentistry, The University of Rochester , Rochester, NY , USA
| | - Ravi S Misra
- Department of Pediatrics, School of Medicine and Dentistry, The University of Rochester , Rochester, NY , USA
| | - Michael A O'Reilly
- Department of Pediatrics, School of Medicine and Dentistry, The University of Rochester , Rochester, NY , USA ; Department of Environmental Medicine, School of Medicine and Dentistry, The University of Rochester , Rochester, NY , USA
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Sturrock A, Baker JA, Mir-Kasimov M, Paine R. Contrasting effects of hyperoxia on GM-CSF gene transcription in alveolar epithelial cells and T cells. Physiol Rep 2015; 3:3/3/e12324. [PMID: 25747588 PMCID: PMC4393158 DOI: 10.14814/phy2.12324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Granulocyte/macrophage colony-stimulating factor (GM-CSF) is critically important for normal pulmonary innate immunity and for functional maturation of alveolar macrophages. Alveolar epithelial cells (AEC) are a major source of GM-CSF in the lung and express this growth factor constitutively, whereas most other cells, including T cells, express GM-CSF following inflammatory stimulation. AEC expression of GM-CSF is suppressed by oxidative stress, at least in part through induction of microRNA leading to increased mRNA turnover. In this report, we compare and contrast the effect of hyperoxia on transcriptional aspects of gene regulation of GM-CSF in lung epithelia and T cells of human and mouse origin. Similar to primary murine AEC, human H820 cells that express multiple characteristics of normal alveolar epithelial cells express GM-CSF constitutively, with decreased expression and increased mRNA turnover following exposure to hyperoxia. In contrast, hyperoxia induces augmented GM-CSF expression in human and murine activated T cells, in association with enhanced GM-CSF mRNA stability. Alveolar epithelial cells demonstrate constitutive transcription, with the proximal promoter in an open configuration in normoxia, without change in hyperoxia. Conversely, in both human and murine T cells, hyperoxia increased GM-CSF gene transcription. The proximal promoter was in a closed configuration in unstimulated T cells but became accessible upon activation and still more accessible in activated T cells exposed to hyperoxia. These fundamental differences in molecular regulation of GM-CSF expression highlight the distinctive niche of alveolar epithelial cell expression of GM-CSF and offer insights into the biology of GM-CSF in the setting of acute lung injury.
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Affiliation(s)
- Anne Sturrock
- Department of Veterans, Affairs Medical Center, Salt Lake City, Utah, USA Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Jessica A Baker
- Department of Veterans, Affairs Medical Center, Salt Lake City, Utah, USA Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Mustafa Mir-Kasimov
- Department of Veterans, Affairs Medical Center, Salt Lake City, Utah, USA Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Robert Paine
- Department of Veterans, Affairs Medical Center, Salt Lake City, Utah, USA Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA
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Sturrock A, Mir-Kasimov M, Baker J, Rowley J, Paine R. Key role of microRNA in the regulation of granulocyte macrophage colony-stimulating factor expression in murine alveolar epithelial cells during oxidative stress. J Biol Chem 2013; 289:4095-105. [PMID: 24371146 DOI: 10.1074/jbc.m113.535922] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
GM-CSF is an endogenous pulmonary cytokine produced by normal alveolar epithelial cells (AEC) that is a key defender of the alveolar space. AEC GM-CSF expression is suppressed by oxidative stress through alternations in mRNA turnover, an effect that is reversed by treatment with recombinant GM-CSF. We hypothesized that specific microRNA (miRNA) would play a key role in AEC GM-CSF regulation. A genome-wide miRNA microarray identified 19 candidate miRNA altered in primary AEC during oxidative stress with reversal by treatment with GM-CSF. Three of these miRNA (miR 133a, miR 133a*, and miR 133b) are also predicted to bind the GM-CSF 3'-untranslated region (UTR). PCR for the mature miRNA confirmed induction during oxidative stress that was reversed by treatment with GM-CSF. Experiments using a GM-CSF 3'-UTR reporter construct demonstrated that miR133a and miR133b effects on GM-CSF expression are through interactions with the GM-CSF 3'-UTR. Using lentiviral transduction of specific mimics and inhibitors in primary murine AEC, we determined that miR133a and miR133b suppress GM-CSF expression and that their inhibition both reverses oxidant-induced suppression of GM-CSF expression and increases basal expression of GM-CSF in cells in normoxia. In contrast, these miRNAs are not active in regulation of GM-CSF expression in murine EL4 T cells. Thus, members of the miR133 family play key roles in regulation of GM-CSF expression through effects on mRNA turnover in AEC during oxidative stress. Increased understanding of GM-CSF gene regulation may provide novel miRNA-based interventions to augment pulmonary innate immune defense in lung injury.
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Affiliation(s)
- Anne Sturrock
- From the Department of Veterans Affairs Medical Center, Salt Lake City, Utah 84148 and
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Unkel B, Hoegner K, Clausen BE, Lewe-Schlosser P, Bodner J, Gattenloehner S, Janßen H, Seeger W, Lohmeyer J, Herold S. Alveolar epithelial cells orchestrate DC function in murine viral pneumonia. J Clin Invest 2012; 122:3652-64. [PMID: 22996662 DOI: 10.1172/jci62139] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 07/19/2012] [Indexed: 12/23/2022] Open
Abstract
Influenza viruses (IVs) cause pneumonia in humans with progression to lung failure. Pulmonary DCs are key players in the antiviral immune response, which is crucial to restore alveolar barrier function. The mechanisms of expansion and activation of pulmonary DC populations in lung infection remain widely elusive. Using mouse BM chimeric and cell-specific depletion approaches, we demonstrated that alveolar epithelial cell (AEC) GM-CSF mediates recovery from IV-induced injury by affecting lung DC function. Epithelial GM-CSF induced the recruitment of CD11b+ and monocyte-derived DCs. GM-CSF was also required for the presence of CD103+ DCs in the lung parenchyma at baseline and for their sufficient activation and migration to the draining mediastinal lymph nodes (MLNs) during IV infection. These activated CD103+ DCs were indispensable for sufficient clearance of IVs by CD8+ T cells and for recovery from IV-induced lung injury. Moreover, GM-CSF applied intratracheally activated CD103+ DCs, inducing increased migration to MLNs, enhanced viral clearance, and attenuated lung injury. Together, our data reveal that GM-CSF-dependent cross-talk between IV-infected AECs and CD103+ DCs is crucial for effective viral clearance and recovery from injury, which has potential implications for GM-CSF treatment in severe IV pneumonia.
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Affiliation(s)
- Barbara Unkel
- Department of Internal Medicine II, University of Giessen and Marburg Lung Center, Giessen, Germany
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9
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Mir-Kasimov M, Sturrock A, McManus M, Paine R. Effect of alveolar epithelial cell plasticity on the regulation of GM-CSF expression. Am J Physiol Lung Cell Mol Physiol 2012; 302:L504-11. [DOI: 10.1152/ajplung.00303.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Local pulmonary expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) is critically important for defense of the pulmonary alveolar space. It is required for surfactant homeostasis and pulmonary innate immune responses and is protective against lung injury and aberrant repair. Alveolar epithelial cells (AEC) are a major source of GM-CSF; however, the control of homeostatic expression of GM-CSF is incompletely characterized. Increasing evidence suggests considerable plasticity of expression of AEC phenotypic characteristics. We tested the hypothesis that this plasticity extends to regulation of expression of GM-CSF using 1) MLE-12 cells (a commonly used murine cell line expressing some features of normal type II AEC, 2) primary murine AEC incubated under standard conditions [resulting in rapid spreading and loss of surfactant protein C (SP-C) expression with induction of the putative type I cell marker (T1α)], or 3) primary murine AEC on a hyaluronic acid/collagen matrix in defined medium, resulting in preservation of SP-C expression. AEC in standard cultures constitutively express abundant GM-CSF, with further induction in response to IL-1β but little response to TNF-α. In contrast, primary cells cultured to preserve SP-C expression and MLE-12 cells both express little GM-CSF constitutively, with significant induction in response to TNF-α and limited response to IL-1β. We conclude that constitutive and cytokine-induced expression of GM-CSF by AEC varies in concert with other cellular phenotypic characteristics. These changes may have important implications both for the maintenance of normal pulmonary homeostasis and for the process of repair following lung injury.
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Affiliation(s)
- Mustafa Mir-Kasimov
- Department of Veterans Affairs Medical Center; and Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah
| | - Anne Sturrock
- Department of Veterans Affairs Medical Center; and Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah
| | - Michael McManus
- Department of Veterans Affairs Medical Center; and Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah
| | - Robert Paine
- Department of Veterans Affairs Medical Center; and Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, University of Utah School of Medicine, Salt Lake City, Utah
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Lee HJ, Choi CW, Kim EK, Kim HS, Kim BI, Choi JH. Granulocyte colony-stimulating factor reduces hyperoxia-induced alveolarization inhibition by increasing angiogenic factors. Neonatology 2012; 101:278-84. [PMID: 22286224 DOI: 10.1159/000335285] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 11/22/2011] [Indexed: 01/04/2023]
Abstract
BACKGROUND Granulocyte colony-stimulating factor (G-CSF) is known to mobilize endothelial progenitor cells (EPCs) from bone marrow. EPCs reportedly promote neovascularization and participate in the repair of lung structure in adult animals. OBJECTIVE We tested the hypothesis that G-CSF contributes to alveolar growth by increasing the production of angiogenic growth factor in the lungs of hyperoxia-exposed neonatal mice. METHODS Neonatal mice were exposed to hyperoxia (80%) or room air (RA) for 7 days and treated with G-CSF (50 μg/kg/day) or vehicle for 5 days. Blood was subjected to flow cytometry to gate for CD45(dim/-)/Sca-1(+)/CD133(+)/vascular endothelial growth factor (VEGF) receptor-2 (VEGFR2) to define the EPC population at day 7. RESULTS The percentage of EPCs in the peripheral blood and VEGF and VEGFR2 levels in the lungs of neonatal mice exposed to hyperoxia were significantly reduced compared to those of mice kept in RA. G-CSF significantly increased EPCs in the peripheral blood, and VEGF and VEGFR2 levels in the lungs of both mice exposed to hyperoxia and mice kept in RA. G-CSF restored alveolarization inhibited by hyperoxia without altering normal alveolarization under RA. CONCLUSION G-CSF restored alveolarization inhibited by hyperoxia in the developing lungs and this alveolarization-enhancing effect of G-CSF is associated with mobilization of EPCs and upregulation of VEGF signaling.
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Affiliation(s)
- Hyun Ju Lee
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
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Sturrock A, Seedahmed E, Mir-Kasimov M, Boltax J, McManus ML, Paine R. GM-CSF provides autocrine protection for murine alveolar epithelial cells from oxidant-induced mitochondrial injury. Am J Physiol Lung Cell Mol Physiol 2011; 302:L343-51. [PMID: 22140071 DOI: 10.1152/ajplung.00276.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Exposure of mice to hyperoxia induces alveolar epithelial cell (AEC) injury, acute lung injury and death. Overexpression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lung protects against these effects, although the mechanisms are not yet clear. Hyperoxia induces cellular injury via effects on mitochondrial integrity, associated with induction of proapoptotic members of the Bcl-2 family. We hypothesized that GM-CSF protects AEC through effects on mitochondrial integrity. MLE-12 cells (a murine type II cell line) and primary murine type II AEC were subjected to oxidative stress by exposure to 80% oxygen and by exposure to H(2)O(2). Exposure to H(2)O(2) induced cytochrome c release and decreased mitochondrial reductase activity in MLE-12 cells. Incubation with GM-CSF significantly attenuated these effects. Protection induced by GM-CSF was associated with Akt activation. GM-CSF treatment also resulted in increased expression of the antiapoptotic Bcl-2 family member, Mcl-1. Primary murine AEC were significantly more tolerant of oxidative stress than MLE-12 cells. In contrast to MLE-12 cells, primary AEC expressed significant GM-CSF at baseline and demonstrated constitutive activation of Akt and increased baseline expression of Mcl-1. Treatment with exogenous GM-CSF further increased Akt activation and Mcl-1 expression in primary AEC. Conversely, suppression of AEC GM-CSF expression by use of GM-CSF-specific small interfering RNA resulted in decreased tolerance of oxidative stress, Furthermore, silencing of Mcl-1 prevented GM-CSF-induced protection. We conclude that GM-CSF protects alveolar epithelial cells against oxidative stress-induced mitochondrial injury via the Akt pathway and its downstream components, including Mcl-1. Epithelial cell-derived GM-CSF may contribute to intrinsic defense mechanisms limiting lung injury.
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Affiliation(s)
- Anne Sturrock
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Univ. of Utah School of Medicine, Salt Lake City, UT 84132, USA
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Schwingshackl A, Teng B, Ghosh M, West AN, Makena P, Gorantla V, Sinclair SE, Waters CM. Regulation and function of the two-pore-domain (K2P) potassium channel Trek-1 in alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2011; 302:L93-L102. [PMID: 21949155 DOI: 10.1152/ajplung.00078.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Hyperoxia can lead to a myriad of deleterious effects in the lung including epithelial damage and diffuse inflammation. The specific mechanisms by which hyperoxia promotes these pathological changes are not completely understood. Activation of ion channels has been proposed as one of the mechanisms required for cell activation and mediator secretion. The two-pore-domain K(+) channel (K2P) Trek-1 has recently been described in lung epithelial cells, but its function remains elusive. In this study we hypothesized that hyperoxia affects expression of Trek-1 in alveolar epithelial cells and that Trek-1 is involved in regulation of cell proliferation and cytokine secretion. We found gene expression of several K2P channels in mouse alveolar epithelial cells (MLE-12), and expression of Trek-1 was significantly downregulated in cultured cells and lungs of mice exposed to hyperoxia. Similarly, proliferation cell nuclear antigen (PCNA) and Cyclin D1 expression were downregulated by exposure to hyperoxia. We developed an MLE-12 cell line deficient in Trek-1 expression using shRNA and found that Trek-1 deficiency resulted in increased cell proliferation and upregulation of PCNA but not Cyclin D1. Furthermore, IL-6 and regulated on activation normal T-expressed and presumably secreted (RANTES) secretion was decreased in Trek-1-deficient cells, whereas release of monocyte chemoattractant protein-1 was increased. Release of KC/IL-8 was not affected by Trek-1 deficiency. Overall, deficiency of Trek-1 had a more pronounced effect on mediator secretion than exposure to hyperoxia. This is the first report suggesting that the K(+) channel Trek-1 could be involved in regulation of alveolar epithelial cell proliferation and cytokine secretion, but a direct association with hyperoxia-induced changes in Trek-1 levels remains elusive.
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Affiliation(s)
- Andreas Schwingshackl
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee 38111, USA.
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