Abstract
This study examined the protein expression in lung tissues of rats exposed to radon and cigarette smoke using a proteomic approach. Male Wistar rats were exposed daily to radon at a concentration of 100,000 Bq/m(3) for 16 h, and then exposed to 20% cigarette smoke for 1 h for a period of 75 d, with the radon cumulative dose reaching 200 WLM (working level months). Proteins from rat lung tissue were separated by two-dimensional gel electrophoresis (2-DE), stained with Coomassie blue, and analyzed with ImageMaster two-dimensional (2D) platinum software. Differentially expressed proteins were analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MALDI-time of flight [TOF] MS or MALDI TOF/TOF-MS). Twenty prominent proteins that were correlated with signal transduction, metabolism, heat shock and stress, and cytoskeleton construction were identified. Some of the differential expression proteins were verified by Western blot analysis and immunohistochemical staining, and the results were consistent with 2-DE analysis. The identified proteins and peptides might be potential diagnostic markers of lung impairment induced by radon and cigarette smoke exposure.