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ID 51466
FullText URL
Author
Fuchimoto, Yasuko
Ikeda, Genyo
Ono, Katsuichiro
Tanimoto, Yasushi
Gelfand, Erwin W.
Abstract
Background: Chronic asthma is often associated with neutrophilic infiltration in the airways. Neutrophils contain elastase, a potent secretagogue in the airways, nonetheless the role for neutrophil elastase as well as neutrophilic inflammation in allergen-induced airway responses is not well defined. In this study, we have investigated the impact of neutrophil elastase inhibition on the development of allergic airway inflammation and airway hyperresponsiveness (AHR) in previously sensitized and challenged mice. Methods: BALB/c mice were sensitized and challenged (primary) with ovalbumin (OVA). Six weeks later, a single OVA aerosol (secondary challenge) was delivered and airway inflammation and airway responses were monitored 6 and 48 hrs later. An inhibitor of neutrophil elastase was administered prior to secondary challenge. Results: Mice developed a two-phase airway inflammatory response after secondary allergen challenge, one neutrophilic at 6 hr and the other eosinophilic, at 48 hr. PAR-2 expression in the lung tissues was enhanced following secondary challenge, and that PAR-2 intracellular expression on peribronchial lymph node (PBLN) T cells was also increased following allergen challenge of sensitized mice. Inhibition of neutrophil elastase significantly attenuated AHR, goblet cell metaplasia, and inflammatory cell accumulation in the airways following secondary OVA challenge. Levels of IL-4, IL-5 and IL-13, and eotaxin in BAL fluid 6 hr after secondary allergen challenge were significantly suppressed by the treatment. At 48 hr, treatment with the neutrophil elastase inhibitor significantly reduced the levels of IL-13 and TGF-beta 1 in the BAL fluid. In parallel, in vitro IL-13 production was significantly inhibited in spleen cells from sensitized mice. Conclusion: These data indicate that neutrophil elastase plays an important role in the development of allergic airway inflammation and hyperresponsiveness, and would suggest that the neutrophil elastase inhibitor reduced AHR to inhaled methacholine indicating the potential for its use as a modulator of the immune/inflammatory response in both the neutrophil-and eosinophil-dominant phases of the response to secondary allergen challenge.
Keywords
Neutrophil
Elastase
Airway
Hyperresponsiveness
Asthma
Published Date
2013-01-24
Publication Title
Respiratory Research
Volume
volume14
Publisher
Biomed Central Ltd
ISSN
1465-993X
Content Type
Journal Article
Official Url
http://dx.doi.org/10.1186/1465-9921-14-8
Related Url
http://ousar.lib.okayama-u.ac.jp/metadata/51447
language
英語
File Version
publisher
Refereed
True
DOI
Web of Sience KeyUT