Nasal protein profiles in work-related asthma caused by different exposures.

BACKGROUND: The mechanisms of work-related asthma (WRA) are incompletely delineated. Nasal cell samples may be informative about processes in the lower airways. Our aim was to determine the nasal protein expression profiles of WRA caused by different kind of exposures.

METHODS: We collected nasal brush samples from 82 nonsmoking participants, including healthy controls and WRA patients exposed to (i) protein allergens, (ii) isocyanates and (iii) welding fumes the day after relevant exposure. The proteome changes in samples were analysed by two-dimensional difference gel electrophoresis, and the differentially regulated proteins found were identified by mass spectrometry. Immunological comparison was carried out using Western blot.

RESULTS: We detected an average of 2500 spots per protein gel. Altogether, 228 protein spots were chosen for identification, yielding 77 different proteins. Compared to the controls, exposure to protein allergens had the largest effects on the proteome. Hierarchical clustering revealed that protein allergen- and isocyanate-related asthma had similar profiles, whereas asthma related to welding fumes differed. The highly overrepresented functional categories in the asthma groups were defence response, protease inhibitor activity, inflammatory and calcium signalling, complement activation and cellular response to oxidative stress. Immunological analysis confirmed the found abundance differences in galectin 10 and protein S100-A9 between the groups.

CONCLUSIONS: Work-related asthma patients exposed to protein allergens and isocyanates elicit similar nasal proteome responses and the profiles of welders and healthy controls were alike. Revealed biological activities of the protein expression changes are associated with allergic inflammation and asthma.