Exposure of differentiated airway epithelial cells to volatile smoke in vitro.
BACKGROUND
Cigarette smoke (CS) is the predominant pathogenetic factor in the development of chronic bronchitis and chronic obstructive pulmonary disease. The knowledge about the cellular and molecular mechanisms underlying the smoke-induced inflammation in epithelial cells is limited.


OBJECTIVE
The aim of this study was to develop an in vitro model to monitor the effects of volatile CS on differentiated airway epithelial cells.


METHODS
The airway epithelial cell line MM-39 and primary human bronchial epithelial cells were cultivated as air-liquid interface cultures and exposed directly to volatile CS. We used two types of exposure models, one using ambient air, the other using humidified and warm air. Cytokine levels were measured by quantitative PCR and ELISA. Phosphorylation of p38 MAP kinase was assessed by Western blot analysis. To reduce the smoke-induced inflammation, antisense oligonucleotides directed against the p65 subunit of NF-kappaB were applied.


RESULTS
Exposure of epithelia to cold and dry air resulted in a significant inflammatory response. In contrast, exposure to humidified warm air did not elicit a cellular response. Stimulation with CS resulted in upregulation of mRNA for IL-6 and IL-8 and protein release. Exposure to CS combined with heat-inactivated bacteria synergistically increased levels of the cytokines. Reactions of differentiated epithelial cells to smoke are mediated by the MAP kinase p38 and the transcription factor NF-kappaB.


CONCLUSIONS
We developed an exposure model to examine the consequences of direct exposure of differentiated airway epithelial cells to volatile CS. The model enables to measure the cellular reactions to smoke exposure and to determine the outcome of therapeutic interventions.
Department of Internal Medicine, Division of Pulmonary Diseases, Philipps University of Marburg, Marburg, Germany.
Christoph
C
Beisswenger
Juliane
J
Platz
Carola
C
Seifart
Claus
C
Vogelmeier
Robert
R
Bals
D001273:Atmosphere Exposure Chambers; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects*; D006801:Humans; D006813:Humidity; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012906:Smoke / Q000009:adverse effects*; D014026:Nicotiana; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D016328:NF-kappa B; D012906:Smoke; D048051:p38 Mitogen-Activated Protein Kinases