umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Ozone-induced bronchial epithelial cytokine expression differs between healthy and asthmatic subjects
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
Show others and affiliations
2003 (English)In: Clinical and Experimental Allergy, ISSN 0954-7894, E-ISSN 1365-2222, Vol. 33, no 6, 777-782 p.Article in journal (Refereed) Published
Abstract [en]

Background Ozone (O3) is a common air pollutant associated with adverse health effects. Asthmatics have been suggested to be a particularly sensitive group.

Objective This study evaluated whether bronchial epithelial cytokine expression would differ between healthy and allergic asthmatics after ozone exposure, representing an explanatory model for differences in susceptibility.

Methods Healthy and mild allergic asthmatic subjects (using only inhaled β2-agonists prn) were exposed for 2 h in blinded and randomized sequence to 0.2 ppm of O3 and filtered air. Bronchoscopy with bronchial mucosal biopsies was performed 6 h after exposure. Biopsies were embedded in GMA and stained with mAbs for epithelial expression of IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α, GRO-α, granulocyte–macrophage colony-stimulating factor (GM–CSF), fractalkine and ENA-78.

Results When comparing the two groups at baseline, the asthmatic subjects showed a significantly higher expression of IL-4 and IL-5. After O3 exposure the epithelial expression of IL-5, GM–CSF, ENA-78 and IL-8 increased significantly in asthmatics, as compared to healthy subjects.

Conclusion The present study confirms a difference in epithelial cytokine expression between mild atopic asthmatics and healthy controls, as well as a differential epithelial cytokine response to O3. This O3-induced upregulation of T helper type 2 (Th2)-related cytokines and neutrophil chemoattractants shown in the asthmatic group may contribute to a subsequent worsening of the airway inflammation, and help to explain their differential sensitivity to O3 pollution episodes.

Place, publisher, year, edition, pages
2003. Vol. 33, no 6, 777-782 p.
Keyword [en]
air pollution;asthmatics;bronchial epithelium;cytokines;ozone
National Category
Respiratory Medicine and Allergy
Identifiers
URN: urn:nbn:se:umu:diva-2209DOI: 10.1046/j.1365-2222.2003.01662.xOAI: oai:DiVA.org:umu-2209DiVA: diva2:140102
Available from: 2007-04-02 Created: 2007-04-02 Last updated: 2012-03-01Bibliographically approved
In thesis
1. Ozone and diesel exhaust: airway signaling, inflammation and pollutant interactions
Open this publication in new window or tab >>Ozone and diesel exhaust: airway signaling, inflammation and pollutant interactions
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

It is well established that air pollution has detrimental effects on both human health as well as the environment. Exposure to ozone and particulate matter pollution, is associated with an increase in cardiopulmonary mortality and morbidity. Asthmatics, elderly and children have been indicated as especially sensitive groups. With a global increase in use of vehicles and industry, ambient air pollution represents a crucial health concern as well as a political, economical and environmental dilemma.

Both ozone (O3) and diesel exhaust (DE) trigger oxidative stress and inflammation in the airways, causing symptoms such as wheezing, coughing and reduced lung function. The aim of this thesis was to further examine which pro-inflammatory signaling pathways that are initiated in the airways by ozone, as compared to diesel exhaust. Furthermore, to study the effects of these two ambient air pollutants in a sequential exposure, thus mimicking an urban profile. In order to investigate this in healthy as well as asthmatic subjects, walk-in exposure chambers were utilized and various airway compartments were studied by obtaining induced sputum, endobronchial biopsies, or airway lavage fluids.

In asthmatic subjects, exposure to 0.2 ppm of O3 induced an increase in the cytokines IL 5, GM-CSF and ENA-78 in the bronchial epithelium six hours post-exposure. The healthy subjects, however, displayed no elevations of bronchial epithelial cytokine expression in response to the ozone exposure. The heightened levels of neutrophil chemoattractants and Th2 cytokines in the asthmatic airway epithelium may contribute to symptom exacerbations following air pollution exposure.

When examining an earlier time point post O3 exposure (1½ hours), healthy subjects exhibited a suppression of IL-8 as well as of the transcription factors NFκB and c-jun in the bronchial epithelium, as opposed to after filtered air exposure. This inhibition of early signal transduction in the bronchial epithelium after O3 differs from the response detected after exposure to DE.

Since both O3 and DE are associated with generating airway neutrophilia as well as causing direct oxidative damage, it raises the query of whether daily exposure to these two air pollutants creates a synergistic or additive effect. Induced sputum attained from healthy subjects exposed in sequence to 0.2 ppm of O3 five hours following DE at a PM concentration of 300 µg/m3, demonstrated significantly increased neutrophils, and elevated MPO levels, as compared to the sequential DE and filtered air exposure.

O3 and DE interactions were further investigated by analyses of bronchoalveolar lavage and bronchial wash. It was demonstrated that pre-exposure to DE, as compared to filtered air, enhances the O3-induced airway inflammation, in terms of an increase in neutrophil and macrophage numbers in BW and higher EPX expression in BAL.

In conclusion, this thesis has aspired to expand the knowledge of O3-induced inflammatory pathways in humans, observing a divergence to the previously described DE initiated responses. Moreover, a potentially adverse airway inflammation augmentation has been revealed after exposure to a relevant ambient combination of these air pollutants. This provides a foundation towards an understanding of the cumulative airway effects when exposed to a combination of ambient air pollutants and may have implications regarding future regulations of exposure limits.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2007. 83 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1097
Keyword
air pollution, ozone, diesel exhaust, airway inflammation, asthma, immunohistochemistry
National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
urn:nbn:se:umu:diva-1071 (URN)978-91-7264-266-9 (ISBN)
Public defence
2007-04-21, Sal B, 9 trappor, Tandläkarhuset, Norrlands Universitetssjukhus, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2007-04-02 Created: 2007-04-02 Last updated: 2012-03-01Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Bosson, JennyStenfors, NikolaiBlomberg, AndersBucht, AndersHelleday, RagnberthPourazar, JamshidSandström, Thomas
By organisation
Pulmonary Medicine
In the same journal
Clinical and Experimental Allergy
Respiratory Medicine and Allergy

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 229 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf