Infection Respiratory Epithelium During Adenoviral Stat3 Is Required
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Stat3 Is Required for Cytoprotection of the Respiratory Epithelium during Adenoviral Infection This information is current as Yohei Matsuzaki, Yan Xu, Machiko Ikegami, Valérie of September 24, 2021. Besnard, Kwon-Sik Park, William M. Hull, Susan E. Wert and Jeffrey A. Whitsett J Immunol 2006; 177:527-537; ; doi: 10.4049/jimmunol.177.1.527 http://www.jimmunol.org/content/177/1/527 Downloaded from References This article cites 65 articles, 30 of which you can access for free at: http://www.jimmunol.org/content/177/1/527.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 24, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2006 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Stat3 Is Required for Cytoprotection of the Respiratory Epithelium during Adenoviral Infection1 Yohei Matsuzaki, Yan Xu, Machiko Ikegami, Vale´rie Besnard, Kwon-Sik Park, William M. Hull, Susan E. Wert, and Jeffrey A. Whitsett2 The role of Stat3 in the maintenance of pulmonary homeostasis following adenoviral-mediated lung injury was assessed in vivo. Stat3 was selectively deleted from bronchiolar and alveolar epithelial cells in Stat3⌬⌬ mice. Although lung histology and function were unaltered by deletion of Stat3 in vivo, Stat3⌬⌬ mice were highly susceptible to lung injury caused by intratracheal admin- istration of AV1-GFP, an early (E) region 1- and E3-deleted, nonproliferative adenovirus. Severe airspace enlargement, loss of alveolar septae, and sloughing of the bronchiolar epithelium were observed in Stat3⌬⌬ mice as early as 1 day after exposure to the virus. Although surfactant protein A, B, and C content and surfactant protein-B mRNA expression in Stat3⌬⌬ mice were similar, Downloaded from TUNEL staining and caspase-3 were increased in alveolar type II epithelial cells of Stat3⌬⌬ mice after exposure to virus. RNA microarray analysis of type II epithelial cells isolated from Stat3⌬⌬ mice demonstrated significant changes in expression of numerous genes, including those genes regulating apoptosis, supporting the concept that the susceptibility of Stat3-deficient mice to adenovirus was related to the role of Stat3 in the regulation of cell survival. AV1-Bcl-xL, an E1- and E3-deleted, nonproliferative ⌬⌬ adenovirus expressing the antiapoptotic protein Bcl-xL, protected Stat3 mice from adenoviral-induced lung injury. Adenoviral infection of the lungs of Stat3-deficient mice was associated with severe injury of the alveolar and bronchiolar epithelium. Thus, http://www.jimmunol.org/ Stat3 plays a critical cytoprotective role that is required for epithelial cell survival and maintenance of alveolar structures during the early phases of pulmonary adenoviral infection. The Journal of Immunology, 2006, 177: 527–537. ignal transducers and activators of transcription include a that Stat3 is not required for normal lung morphogenesis or func- family of structurally related proteins that play important tion but is required for maintenance of surfactant homeostasis, S roles in the intracellular transduction of signals regulated lung function, and repair following hyperoxia-induced injury (6). by various cytokines and growth factors. Stat3 was initially iden- Although IL-6, IL-11, and activated Stat3 protect the lung during tified as a transcription factor that mediated the effects of IL-6 in oxidant injury in vivo (7–9), mechanisms by which activation of acute phase response in the liver (1). Stat3 mediates or participates Stat3 maintains lung homeostasis following injury are poorly by guest on September 24, 2021 in the signaling pathways of many cytokines (e.g., IL-6, IL-11, understood. IL-10, IL-2, leukemic inhibitory factor, ciliary neurotrophic factor, The recent severe acute respiratory syndrome outbreak (10) and oncostatin M, leptin, and others) and growth factors (e.g., epider- the ongoing morbidity and mortality associated with influenza and ␣ mal growth factor, TGF- , hepatocyte growth factor, and G-CSF) other pulmonary viral infections has served to raise awareness of in various cells and organs (1–3). Cytokines and growth factors the public health consequences of viral pneumonias and the need activate Stat3 via glycoprotein 130 (gp130)-activating phosphor- for further knowledge regarding the pathogenesis of pulmonary ylation by JAKs. Phosphoryl-Stat3 dimerizes and is transported to viral infections. The mechanisms protecting the respiratory epithe- the nucleus, where it regulates the transcription of target genes. lium from acute cellular injury after exposure to respiratory viruses Because systemic deletion of Stat3 in transgenic mice is lethal at E6.5-7.5 (4), the biological roles of Stat3 have been determined in are complex and include induction of antioxidant, antiapoptotic vitro and after conditional deletion of the gene in various cell types pathways, specific enhancement of cell proliferation, and surfac- and organs of the mouse. Stat3 plays a critical role in the regulation tant production (8, 11, 12). Activation of Stat3 and pre-exposure to of various biological processes, including cell survival, apoptosis, IL-6 protects the lung from injury during hyperoxia (7, 9). inflammation, and proliferation (5). Conditional ablation of Stat3 The lung is repeatedly subjected to injury caused by viral in- in the respiratory epithelium of mice (Stat3⌬⌬ mice) demonstrated fection and other pathogens. Maintenance of pulmonary homeosta- sis requires the continuation of cellular processes and proliferation of cells during viral infection. Infected cells are cleared by acute Division of Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, De- partment of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH and immune-mediated apoptosis and necrosis. In this study, we 45229 assessed the role of Stat3 in pulmonary homeostasis during adeno- Received for publication December 13, 2005. Accepted for publication April viral-mediated lung injury. A conditional system was used to ex- 10, 2006. press Cre-recombinase, selectively deleting the Stat3 gene in bron- The costs of publication of this article were defrayed in part by the payment of page chiolar and alveolar epithelial cells of the mouse lung (6). charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Intratracheal administration of AV1-GFP, an E1- and E3-deleted, 1 This work was supported by National Institutes of Health Grants HL61646 (to M. nonproliferative adenovirus, caused severe lung pathology associ- Ikegami, S.E. Wert, and J.A. Whitsett) and HL38859 (to J.A. Whitsett). ated with enhanced apoptosis of the respiratory epithelium in 2 Address correspondence and reprint requests to Dr. Jeffrey A. Whitsett, Cincinnati Stat3⌬⌬ mice. These results demonstrate that Stat3 plays a critical Children’s Hospital Medical Center, Divisions of Neonatology and Pulmonary Biol- ogy, 3333 Burnet Avenue, Cincinnati, OH 45229-3039. E-mail address: role in cytoprotection of the lung during the early phases of viral [email protected] pneumonia. Copyright © 2006 by The American Association of Immunologists, Inc. 0022-1767/06/$02.00 528 Stat3 AND CYTOPROTECTION OF THE LUNG Table I. Comparison of histology scoring in control and Stat3⌬/⌬a Saline AV1-GFP Statstical Analysis Control vs Stat3⌬/⌬ Stat3⌬/⌬ ϩ Saline vs Morphometric Analysis Control Stat3⌬/⌬ Control Stat3⌬/⌬ after AV1-GFP Stat3⌬/⌬ ϩ AV1-GFP Alveolar epithelium Mean Mean Mean Mean p Value p Value Airspace enlargement 0.1 0.3 0.3 3.6 Ͻ0.05 Ͻ0.05 Loss of alveolar septae 0.1 0.3 0.1 3.5 Ͻ0.05 Ͻ0.05 Congestion 0.2 0.1 1.4 4.1 Ͻ0.05 Ͻ0.05 Hemorrhage 1.0 1.1 1.1 1.5 N.S. Ͻ0.05 Alveolar protein 0.9 0.9 1.3 2.9 Ͻ0.05 Ͻ0.05 Bronchiolar epithelium Epithelial sloughing 0.0 0.2 0.4 1.9 Ͻ0.05 Ͻ0.05 Cellular necrosis 0.0 0.0 0.0 0.0 NS NS Inflammation Neutrophil infiltrates 0.0 0.0 0.1 0.5 NS NS Macrophage infiltrates 1.2 0.8 1.7 3.6 Ͻ0.05 Ͻ0.05 a Histology from four mice per group was analyzed 48 h after exposure to AV1-GFP or saline. Fourteen lobes for saline exposure groups, 15 lobes for AV1-GFP exposure groups. Lobes were scored from 0 to 5 with 0 being normal or no histopathology, and 5 being the most severely affected. Kruskal-Wallis one-way analysis and Dunn’s method were performed with individual scores for each characteristic to determine significant difference; significance was accepted at the 5% level. Downloaded from Materials and Methods resentative of findings from at least four Stat3⌬⌬ mice compared with Gene construction and doxycycline administration control mice. flx/flx SP-C-rtTA/(tetO)7CMV-Cre/Stat3 triple-transgenic mice were gener- TUNEL assay flx/flx ated as described previously (6). Stat3 mice were a gift from Dr. http://www.jimmunol.org/ Takeda (Hyogo College of Medicine,