Corticosteroids increase secretory leukocyte protease inhibitor transcript levels in airway epithelial cells

1995 ◽  
Vol 268 (4) ◽  
pp. L601-L606 ◽  
Author(s):  
J. M. Abbinante-Nissen ◽  
L. G. Simpson ◽  
G. D. Leikauf

Secretory leukocyte protease inhibitor (SLPI) is the predominant antiprotease of the conducting airways and may play a role in reducing airway inflammation. In this study, the effect of corticosteroids used in the treatment of inflammatory airway disease on SLPI transcript levels was investigated. When human airway epithelial cells (9HTEo-) were treated continuously with 10 nM fluticasone propionate, SLPI transcript levels increased within 12 h, with maximal transcript accumulation occurring at 24–48 h. Several corticosteroids (0.1-1,000 nM) were compared, and the following potency in increasing SLPI transcript levels was observed: fluticasone > triamcinolone > or = dexamethasone > methylprednisolone > hydrocortisone. Fluticasone, the most potent corticosteroid, increased SLPI transcript levels at doses as low as 0.1 nM, whereas hydrocortisone, the least potent corticosteroid, was effective at 100 nM. Fluticasone-induced increases in SLPI transcript levels were inhibited by cycloheximide, suggesting protein synthesis may be required for this response. Because proteases are likely to be present when corticosteroids are administered therapeutically, we examined the interaction between elastase and fluticasone and found they act synergistically to increase SLPI transcript levels. Our findings suggest that corticosteroids may exert their antiinflammatory effects in part by increasing airway epithelial cell SLPI production.

1993 ◽  
Vol 265 (3) ◽  
pp. L286-L292 ◽  
Author(s):  
J. M. Abbinante-Nissen ◽  
L. G. Simpson ◽  
G. D. Leikauf

Airway inflammation is often associated with the infiltration of activated neutrophils and subsequent protease release. Although aiding in the digestion and phagocytosis of foreign proteins and microorganisms, neutrophil proteases can indiscriminately damage healthy lung tissue. In the conducting airway, proteases, particularly neutrophil elastase, are counter-balanced by several antiproteases, including secretory leukocyte protease inhibitor (SLPI). SLPI can be produced locally by a number of cells including the airway epithelial cell. To examine the effects of neutrophil granule components on SLPI transcript levels, airway epithelial cells were treated (up to 96 h) with elastase, other proteases, or enzymes isolated from human sputum. We found that neutrophil elastase increased SLPI transcript levels in primary and transformed human airway epithelial cells in a time- and dose-dependent manner. Other neutrophil products, such as cathepsin G, myeloperoxidase, and lysozyme, had little or no effect on SLPI transcript levels. However, two nonneutrophil proteases, trypsin and pancreatic elastase, also increased SLPI transcript levels at higher doses than that required of neutrophil elastase. Two inflammatory cytokines, tumor necrosis factor-alpha and interleukin-8, produced little or no effect on SLPI transcript levels. This study demonstrates one way in which SLPI is regulated, via a protease that it inhibits, neutrophil elastase.


2006 ◽  
Vol 80 (11) ◽  
pp. 5301-5307 ◽  
Author(s):  
Michael A. James ◽  
John H. Lee ◽  
Aloysius J. Klingelhutz

ABSTRACT Infection with human papillomavirus (HPV) is a critical factor in the pathogenesis of most cervical cancers and some aerodigestive cancers. The HPV E6 oncoprotein from high-risk HPV types contributes to the immortalization and transformation of cells by multiple mechanisms, including degradation of p53, transcriptional activation of human telomerase reverse transcriptase (hTERT), and degradation of several proteins containing PDZ domains. The ability of E6 to bind PDZ domain-containing proteins is independent of p53 degradation or hTERT activation but does correlate with oncogenic potential (R. A. Watson, M. Thomas, L. Banks, and S. Roberts, J. Cell Sci. 116:4925-4934, 2003) and is essential for induction of epithelial hyperplasia in vivo (M. L. Nguyen, M. M. Nguyen, D. Lee, A. E. Griep, and P. F. Lambert, J. Virol. 77:6957-6964, 2003). In this study, we found that HPV type 16 E6 was able to activate NF-κB in airway epithelial cells through the induction of nuclear binding activity of p52-containing NF-κB complexes in a PDZ binding motif-dependent manner. Transcript accumulation for the NF-κB-responsive antiapoptotic gene encoding cIAP-2 and binding of nuclear factors to the proximal NF-κB binding site of the cIAP-2 gene promoter are induced by E6 expression. Furthermore, E6 is able to protect cells from TNF-induced apoptosis. All of these E6-dependent phenotypes are dependent on the presence of the PDZ binding motif of E6. Our results imply a role for targeting of PDZ proteins by E6 in NF-κB activation and protection from apoptosis in airway epithelial cells.


2016 ◽  
Vol 90 (21) ◽  
pp. 9618-9631 ◽  
Author(s):  
Yashoda M. Hosakote ◽  
Allan R. Brasier ◽  
Antonella Casola ◽  
Roberto P. Garofalo ◽  
Alexander Kurosky

ABSTRACTRespiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infant and elderly populations worldwide. Currently, there is no efficacious vaccine or therapy available for RSV infection. The molecular mechanisms underlying RSV-induced acute airway disease and associated long-term consequences remain largely unknown; however, experimental evidence suggests that the lung inflammatory response plays a fundamental role in the outcome of RSV infection. High-mobility group box 1 (HMGB1) is a nuclear protein that triggers inflammation when released from activated immune or necrotic cells and drives the pathogenesis of various infectious agents. Although HMGB1 has been implicated in many inflammatory diseases, its role in RSV-induced airway inflammation has not been investigated. This study investigates the molecular mechanism of action of extracellularly released HMGB1 in airway epithelial cells (A549 and small airway epithelial cells) to establish its role in RSV infection. Immunofluorescence microscopy and Western blotting results showed that RSV infection of human airway epithelial cells induced a significant release of HMGB1 as a result of translocation of HMGB1 from the cell nuclei to the cytoplasm and subsequent release into the extracellular space. Treating RSV-infected A549 cells with antioxidants significantly inhibited RSV-induced HMGB1 extracellular release. Studies using recombinant HMGB1 triggered immune responses by activating primary human monocytes. Finally, HMGB1 released by airway epithelial cells due to RSV infection appears to function as a paracrine factor priming epithelial cells and monocytes to inflammatory stimuli in the airways.IMPORTANCERSV is a major cause of serious lower respiratory tract infections in young children and causes severe respiratory morbidity and mortality in the elderly. In addition, to date there is no effective treatment or vaccine available for RSV infection. The mechanisms responsible for RSV-induced acute airway disease and associated long-term consequences remain largely unknown. The oxidative stress response in the airways plays a major role in the pathogenesis of RSV. HMGB1 is a ubiquitous redox-sensitive multifunctional protein that serves as both a DNA regulatory protein and an extracellular cytokine signaling molecule that promotes airway inflammation as a damage-associated molecular pattern. This study investigated the mechanism of action of HMGB1 in RSV infection with the aim of identifying new inflammatory pathways at the molecular level that may be amenable to therapeutic interventions.


1994 ◽  
Vol 150 (5_pt_2) ◽  
pp. S27-S30 ◽  
Author(s):  
Stephen I. Rennard ◽  
Debra J. Romberger ◽  
Joseph H. Sisson ◽  
Susanna G. Von Essen ◽  
Israel Rubinstein ◽  
...  

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