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: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.
Project description:Airway epithelial cells are the first cells of the lungs to be exposed to the toxic agents contained within cigarette smoke. Accordingly, the response of these cells to this challenge is of considerable interest in the context of diseases in which cigarette smoke is a major aetiological factor. We used Affymetrix microarrays to study the effects of repeated cigarette smoke challenge on three-dimensional human lung airway epithelial cultures.
Project description:Modified-risk tobacco products (MRTP) are designed to reduce the individual risk of tobacco-related disease as well as population harm compared to smoking cigarettes. Experimental proof of their benefit needs to be provided at multiple levels in research fields. Here, we examined microRNA (miRNA) levels in the lungs of rats exposed to a candidate modified-risk tobacco products, the Tobacco Heating System 2.2 (THS2.2) in a 90-day OECD TG-413 inhalation study. Our aim was to assess the miRNA response to THS2.2 aerosol compared with the response to combustible cigarettes (CC) smoke from the reference cigarette 3R4F. CC smoke exposure, but not THS2.2 aerosol exposure, caused global miRNA downregulation, which may be explained by the interference of CC smoke constituents with the miRNA processing machinery. Upregulation of specific miRNA species, such as miR-146a/b and miR-182, indicated that they are causal elements in the inflammatory response in CC-exposed lung, but they were reduced after THS2.2 aerosol exposure. Transforming transcriptomic data into protein activity based on corresponding downstream gene expression, we identified potential mechanisms for miR-146a/b and miR-182 that were activated by CC smoke but not by THS2.2 aerosol and possibly involved in the regulation of those miRNAs. The inclusion of miRNA profiling in systems toxicology approaches increases the mechanistic understanding of the complex exposure responses.
Project description:We previously showed that exposure of rats to environmental cigarette smoke (ECS) causes extensive downregulation of microRNA expression in the lung, resulting in overexpression of multiple genes and proteins. In the present study, we evaluated by microarray the expression of 484 microRNAs in the lung of rats receiving orally chemopreventive agents, including N-acetylcysteine, oltipraz, indole-3-carbinol, 5,6-benzoflavone and phenethyl isothiocyanate, or combinations thereof. Scatterplot, hierarchical cluster, and principal component analyses showed that none of the above chemopreventive regimens appreciably affected the baseline microRNA expression, while all of them attenuated ECS-induced alterations but to a variable extent. Thus, mirnome analysis provides a new tool for predicting both safety and efficacy of cancer chemopreventive agents at early carcinogenesis stages. Keywords: cancer chemoprevention, microRNA, environmental cigarete smoke (ECS), 5,6-benzoflavone (BF), Indole 3-carbinol (I3C),N-acetylcysteine (NAC), oltipraz (OPZ), Phenethyl isothiocyanate (PEITC). Adult male Sprague-Dawley rats (Harlan Italy, Correzzana, Milan, Italy), weighing 315-320 g, were divided into 16 groups, each composed of 8 animals. Half of them were exposed to ECS for 28 consecutive days, as previously described (Izzotti et al., 2005), while the remaining rats (Sham-exposed) were kept for the same period of time in filtered air. The rats belonging to 14 groups were treated with chemopreventive agents, starting 3 days before exposure to ECS.
Project description:Pregnant mice (Dams) were exposed to cigarette smoke or filtered air. Lung tissue and RNA were harvested from the lungs of the Dams and their offspring and underwent transcriptomic analysis.
Project description:Modified risk tobacco products (MRTPs) have the potential to reduce smoking-related health risks. The Carbon Heated Tobacco Product 1.2 (CHTP1.2) is a potential MRTP that uses a pressed carbon heat source to generate an aerosol by heating tobacco. This study reports the results from the systems toxicology arm of a 90-day rat inhalation study (OECD test guideline 413) to assess the effects of CHTP1.2 aerosol compared with cigarette smoke (CS). Rats were exposed to filtered air (sham), to CHTP1.2 aerosol (at 15, 23 and 50 µg nicotine / L), or to the 3R4F reference cigarette smoke (at 23 µg nicotine / L).
Project description:Modified risk tobacco products (MRTPs) have the potential to reduce smoking-related health risks. The Carbon Heated Tobacco Product 1.2 (CHTP1.2) is a potential MRTP that uses a pressed carbon heat source to generate an aerosol by heating tobacco. This study reports the results from the systems toxicology arm of a 90-day rat inhalation study (OECD test guideline 413) to assess the effects of CHTP1.2 aerosol compared with cigarette smoke (CS). Rats were exposed to filtered air (sham), to CHTP1.2 aerosol (at 15, 23 and 50 µg nicotine / L), or to the 3R4F reference cigarette smoke (at 23 µg nicotine / L).
Project description:Modified risk tobacco products (MRTPs) have the potential to reduce smoking-related health risks. The Carbon Heated Tobacco Product 1.2 (CHTP1.2) is a potential MRTP that uses a pressed carbon heat source to generate an aerosol by heating tobacco. This study reports the results from the systems toxicology arm of a 90-day rat inhalation study (OECD test guideline 413) to assess the effects of CHTP1.2 aerosol compared with cigarette smoke (CS). Rats were exposed to filtered air (sham), to CHTP1.2 aerosol (at 15, 23 and 50 µg nicotine / L), or to the 3R4F reference cigarette smoke (at 23 µg nicotine / L).
Project description:Airway epithelial cells are the first cells of the lungs to be exposed to the toxic agents contained within cigarette smoke. Accordingly, the response of these cells to this challenge is of considerable interest in the context of diseases in which cigarette smoke is a major aetiological factor. We used Affymetrix microarrays to study the effects of repeated cigarette smoke challenge on three-dimensional human lung airway epithelial cultures. We have used cultures from four individual donors, and compared the effects of repeated cigarette smoke challenge (30mins exposure on four separate days), with no challenge.