Chest

Chest

Volume 140, Issue 4, October 2011, Pages 980-990
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Original Research
Obstructive Lung Diseases
Dapsone Inhibits IL-8 Secretion From Human Bronchial Epithelial Cells Stimulated With Lipopolysaccharide and Resolves Airway Inflammation in the Ferret

https://doi.org/10.1378/chest.10-2908Get rights and content

Background

IL-8 is an important activator and chemoattractant for neutrophils that is produced by normal human bronchial epithelial (NHBE) cells through mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) p65 pathways. Dapsone, a synthetic sulfone, is widely used to treat chronic neutrophil dermatoses. We investigated the effects of dapsone on polarized IL-8 secretion from lipopolysaccharide (LPS)-stimulated NHBE cells and further evaluated its ability to decrease LPS-induced inflammation in the ferret airway.

Methods

NHBE cells were grown at air-liquid interface (ALI) to ciliated differentiation. Baseline and endotoxin (LPS)-stimulated IL-8 secretion was measured by enzyme-linked immunosorbent assay at air and basal sides with and without dapsone. Western blotting was used to determine signaling pathways. In vivo, ferrets were exposed to intratracheal LPS over a period of 5 days. Once inflammation was established, oral or nebulized dapsone was administered for 5 days. Intraepithelial neutrophil accumulation was analyzed histologically, and mucociliary transport was measured on the excised trachea.

Results

Dapsone, 1 μg/mL, did not influence unstimulated (basal) IL-8 secretion. Apical LPS stimulation induced both apical and basolateral IL-8, but basolateral LPS increased only basolateral IL-8. Dapsone inhibited polarized IL-8 secretion from ALI-conditioned cells. Dapsone also decreased LPS-induced IL-8 mRNA level. LPS led to phosphorylation of extracellular signal-regulated kinase 1/2, but not p38 MAPK or c-Jun NH2-terminal kinase. LPS also induced NF-κB p65 phosphorylation, an effect that was inhibited by dapsone. Both oral and aerosol dapsone decreased LPS-induced intraepithelial neutrophil accumulation, but only treatment with aerosol dapsone restored mucociliary transport to normal.

Conclusions

Dapsone, given either systemically or as an aerosol, may be useful in treating neutrophilic airway inflammation.

Section snippets

Reagents

Dapsone (4,4′-diaminodiphenyl sulfone), LPS (Escherichia coli serotype 0111:B4), and all other reagents were purchased from Sigma-Aldrich Corp (St Louis, Missouri), unless otherwise indicated. PD98059 (2′-amino-3′-methoxyflavone), an MAPK/ERK kinase (MEK) inhibitor (an upstream kinase of ERK1/2) was obtained from Calbiochem (La Jolla, California). Phospho- and nonphospho-specific ERK1/2, anti-p38 MAPK, anti-stress-activated protein kinase (SAPK)/JNK, and phospho-specific NF-κB p65 (Ser536) as

Effect of Dapsone on NHBE Cell Viability

To confirm that the total number of cultured NHBE cells was not influenced by dapsone treatment, the viability of cells was evaluated using CCK-8. NHBE cells seeded onto 96-well plates (3,000 cells/well) were cultured at 37°C for 72 h (∼ 70% confluence). Dapsone at concentrations of 0.3, 1, or 10 μg/mL was added for 24 or 72 h. As shown in Figure 1, the total viable cell number was similar to that of the nontreated control group over 72 h.

Effect of Dapsone on LPS-Induced IL-8 Secretion

To evaluate the effect of dapsone on IL-8 secretion from

Discussion

We have shown that dapsone inhibits IL-8 secretion from NHBE cells stimulated with LPS. Dapsone is used to treat dermatologic disorders, most notably those with neutrophil infiltrates.16 It has been postulated that dapsone impairs neutrophil chemotaxis and function at the sites of inflammation, apparently without increased risk of opportunistic infections.21 This is consistent with immunomodulation, but not immunosuppression.14

Dapsone inhibits local production of toxic reactive oxygen species,

Acknowledgments

Author contributions: Dr Rubin had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Dr Kanoh: contributed to the study design, performance of the experiments, and writing of the manuscript.

Dr Tanabe: contributed to the performance of the studies, analysis of the research data, and writing and revision of the manuscript.

Dr Rubin: contributed, as the principal investigator, to the study concept and design,

References (38)

  • C Schulz et al.

    Expression and release of interleukin-8 by human bronchial epithelial cells from patients with chronic obstructive pulmonary disease, smokers, and never-smokers

    Respiration

    (2003)
  • J Li et al.

    Regulation of human airway epithelial cell IL-8 expression by MAP kinases

    Am J Physiol Lung Cell Mol Physiol

    (2002)
  • M Shinkai et al.

    Macrolide antibiotics modulate ERK phosphorylation and IL-8 and GM-CSF production by human bronchial epithelial cells

    Am J Physiol Lung Cell Mol Physiol

    (2006)
  • M Shinkai et al.

    Clarithromycin has an immunomodulatory effect on ERK-mediated inflammation induced by Pseudomonas aeruginosa flagellin

    J Antimicrob Chemother

    (2007)
  • J Thorn

    The inflammatory response in humans after inhalation of bacterial endotoxin: a review

    Inflamm Res

    (2001)
  • TH Mogensen

    Pathogen recognition and inflammatory signaling in innate immune defenses

    Clin Microbiol Rev

    (2009)
  • KLW Walton et al.

    Lipopolysaccharide activates innate immune responses in murine intestinal myofibroblasts through multiple signaling pathways

    Am J Physiol Gastrointest Liver Physiol

    (2009)
  • ML Everard et al.

    Macrolide antibiotics in diffuse panbronchiolitis and in cystic fibrosis

    Eur Respir J

    (1997)
  • S Kanoh et al.

    Mechanisms of action and clinical application of macrolides as immunomodulatory medications

    Clin Microbiol Rev

    (2010)

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    Funding/Support: This research was funded by Virginia Commonwealth University and National Defense Medical College (Japan) internal finds.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/site/misc/reprints.xhtml).

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    Copyright © 2011 The American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.