Proteomic differences with and without ozone-exposure in a smoking-induced emphysema lung model

BACKGROUND/AIMS Acute exacerbations in chronic obstructive pulmonary disease may be related to air pollution, of which ozone is an important constituent. In this study, we investigated the protein profiles associated with ozone-induced exacerbations in a smoking-induced emphysema model. METHODS Mice were divided into the following groups: group I, no smoking and no ozone (NS + NO); group II, no smoking and ozone (NS + O); group III, smoking and no ozone (S + NO); and group IV, smoking and ozone (S + O). Bronchoalveolar lavage, the mean linear intercept (MLI) on hematoxylin and eosin staining, nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS), and Western blotting analyses were performed. RESULTS The MLIs of groups III (S + NO) and IV (S + O) (45 ± 2 and 44 ± 3 µm, respectively) were significantly higher than those of groups I (NS + NO) and II (NS + O) (26 ± 2 and 23 ± 2 µm, respectively; p < 0.05). Fourteen spots that showed significantly different intensities on image analyses of two-dimensional (2D) protein electrophoresis in group I (NS + NO) were identified by LC-MS/MS. The levels of six proteins were higher in group IV (S + O). The levels of vimentin, lactate dehydrogenase A, and triose phosphate isomerase were decreased by both smoking and ozone treatment in Western blotting and proteomic analyses. In contrast, TBC1 domain family 5 (TBC1D5) and lamin A were increased by both smoking and ozone treatment. CONCLUSIONS TBC1D5 could be a biomarker of ozone-induced lung injury in emphysema.