Project description:Previous studies have shown that smoking induces oxidative stress and inflammation, known factors that coincide with the development and progression of silicosis. Nevertheless, the precise role of cigarette smoke exposure in silicosis and the underlying mechanisms are not clearly understood. Therefore, the objective of the present study was to determine the effect of smoking, if any, on silica-induced pulmonary response and the underlying mechanisms. Pulmonary toxicity and lung gene expression profiles were determined in male Fischer 344 rats exposed to air, crystalline silica, cigarette smoke or cigarette smoke plus crystalline silica. Silica exposure resulted in significant pulmonary toxicity which was further exacerbated by cigarette smoke exposure in the rats. Significant differences in the gene expression profiles were detected in the lungs of the rats exposed to cigarette smoke, silica or a combination of both compared with the control rats.
Project description:Expression data from rats exposed to cigarette smoke (CS) at three concentrations (sham, 300 µgTPM/l and 600 µgTPM/l) for 13 weeks (5d/week; 2hrs/day) after three different recovery times (2hrs, 6hrs and 20hrs after last treatment); lung tissue Keywords: recovery time course and dose dependency Male Sprague-Dawley rats were nose-only-exposed for 13 weeks in total, 5d/week, 2h/day to following concentrations of mainstream cigarette smoke from the standard reference cigarette 2R4F: sham, 300 µgTPM (Total particulate matter)/l or 600 µgTPM/l.
Project description:Expression data from rats exposed to cigarette smoke (CS) at three concentrations (sham, 300µgTPM/l and 600µgTPM/l) for 13 weeks (5d/week; 2hrs/day) after three different recovery times (2hrs, 6hrs and 20hrs after last treatment); lung tissue Keywords: recovery time course and dose dependency
Project description:These studies tested the hypotheses that smoke induces changes in mRNA profiles that are dependent on sex and the health status of the lung, and that the effects of smoke are different after 1 day compared to 5 days of smoke exposure. The ways in which the lungs modulate their response to cigarette smoke after repeated exposures are important for understanding the toxicology of smoke, for developing biomarkers of chronic smoke exposure, and for understanding the therapeutic potential in regulatory signaling pathways that are beneficial or detrimental to lung health. Sex-matched 5-7-week old wildtype (WT) and Scnn1b-overexpressing (BENaC) littermates were exposed to cigarette smoke or sham (room air) exposure. Exposure occurred in a plexiglass chamber attached to a smoke delivery device using an exposure chamber and smoking machine (inExpose Exposure System, SCIREQ, Chandler, AZ). Mice were exposed to mainstream + sidestream smoke from 6 reference cigarettes with filters removed per day (3R4F research cigarettes, University of Kentucky). Each cigarette was puffed for 2 sec every 25 sec, using the standard Federal Trade Commission smoking machine protocol. The sham-exposed control mice were exposed to room air in the exposure chamber for a time equivalent to that needed for active smoke exposure. Mice were exposed to cigarette or sham smoke for 1 day or 5 consecutive days. Samples were harvested 4 hours after the completion of the final smoke exposure. The right lung was used for gene expression analysis.
Project description:Proteasome dysfunction is emerging as a novel pathomechanism for the development of chronic obstructive pulmonary disease (COPD), a major leading cause of death in the world. Cigarette smoke is one of the main risk factors for COPD and has been shown to impair proteasome function in vitro and in vivo. Importantly, proteasome activity is inhibited in COPD lungs while expression levels of proteasome subunits are not altered. In the present study, we dissected the molecular changes induced by cigarette smoke on proteasome function in lung epithelial cells and mouse lungs. We analyzed the integrity, composition, and the interactome of isolated 26S proteasome complexes from smoke-exposed cells and mouse lungs. Moreover, we applied native MS analysis to investigate whether reactive compounds of cigarette smoke directly modify and inhibit the 20S proteasome complex. Our data reveal that the 20S proteasome is slightly destabilized in the absence of any dominant modification of proteasomal proteins. 26S pulldown and stoichiometry analysis indicated that 26S proteasome complexes become instable in response to cigarette smoke exposure. Of note, the interactome of the 26S was clearly altered in smoke-exposed mouse lungs possibly reflecting an altered cellular composition in the lungs of the smoke-exposed mice. Taken together, our results suggest that cigarette smoke induces minor but detectable changes in the stability and interactome of 20S and 26S proteasome complexes which might contribute in a chronic setting to imbalanced proteostasis as observed in chronic lung diseases associated with cigarette smoking.