Project description:Cigarette smoking is a major risk factor for the development and progression of cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD), so modified risk tobacco products (MRTPs) are being developed to reduce smoking-related health risks. The present study investigated the hallmarks of COPD and CVD over an 8-month period in apolipoprotein E-deficient mice exposed to conventional cigarette smoke (CS) or to an aerosol from a candidate MRTP, the tobacco heating system (THS2.2). In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS was investigated. In a systems toxicology approach, exposure effects were investigated using physiology and histology combined with transcriptomics, lipidomics, and proteomics. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function and alveolar damage). Atherogenic effects of CS exposure included altered lipid profiles and increased aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS: 29.9 mg/m3) did not induce lung inflammation or emphysema, nor did it consistently change the lipid profile or enhance the plaque area. Cessation and switching reversed the inflammatory responses and led to no further progression of initial emphysematous changes or the aortic plaque area. Biological processes, including senescence, inflammation, and proliferation, were significantly impacted in CS, but not THS2.2-exposed tissues. Cessation or switching reduced these perturbations to become nearly indistinguishable from sham exposure. In conclusion, this mouse model indicated that cessation or switching to THS2.2 retarded the progression of atherosclerotic and emphysematous changes, while THS2.2 alone had no adverse effects.
Project description:Chronic obstructive pulmonary disease (COPD) is characterized by a progressive decline in lung function, caused by exposure to exogenous particles, mainly cigarette smoke (CS). COPD pathogenesis is initiated and perpetuated by an abnormal CS-induced inflammatory response of the lungs, involving both innate and adaptive immunity. Specifically, B cells organized in iBALT structures, as well as macrophages, accumulate in the lungs and contribute to CS-induced emphysema, but the mechanisms thereof remain unclear. Here, we demonstrate that B cell-deficient mice are significantly protected against CS-induced emphysema. Chronic CS exposure led to increased lung compliance, total lung capacity, and mean linear chord length in WT, but not B cell-deficient mice, associated with an increased size and number of iBALT structures. The increased accumulation of macrophages around iBALT and in emphysematous alveolar areas in CS-exposed WT mice coincided with upregulated MMP12 expression. In vitro co-culture experiments using B cells and macrophages demonstrated that B cell-derived IL-10 drives macrophage activation and MMP12 upregulation. In summary, B cell function in iBALT formation in CS-induced emphysema provides a new innovative mechanism, which could be explored as a target for therapeutic intervention in COPD patients. Expression data of mice treated with cigarette smoke. Lung tissue was analysed at four and six months of age.
Project description:Cigarette smoking is a major risk factor for the development and progression of diseases such as cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). Modified risk tobacco products (MRTP) are designed to reduce smoking-related health risks. Suitable animal models are important for understanding smoke-induced pathogenesis. Over an 8-month period, hallmarks of both COPD and CVD were investigated in ApoE?/? mice exposed to conventional cigarette smoke (CS) or to an aerosol from a candidate MRTP, the tobacco heating system (THS2.2). In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS were investigated.ᅠ In a systems toxicology approach, classical end points (e.g., physiology, histology) were complemented with transcriptomics, lipidomics, and proteomics analyses. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function, alveolar damage). Atherogenic effects of CS exposure were altered lipid profiles and increased aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS ヨ 29.9 mg/m3) did not induce lung inflammation and emphysema, nor did it consistently change the lipid profile or enhance the plaque area. Cessation and switching caused reversal of inflammatory responses and no progression of initial emphysematous changes and aortic plaque area. Biological processes, e.g., senescence, inflammation, proliferation, were significantly impacted in 3R4F-exposed, but not in THS2.2-exposed tissues. Cessation or switching reduced these perturbations to become nearly indistinguishable from sham-exposure. In conclusion, the mouse model indicated retarded progression of atherosclerotic and emphysematous changes upon cessation or switching to THS2.2 which alone had no adverse effects.
Project description:Smoking cigarettes is a major risk factor in the development and progression of cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). Modified risk tobacco products (MRTPs) are being developed to reduce smoking-related health risks. The goal of this study was to investigate hallmarks of COPD and CVD over an 8-month period in apolipoprotein E-deficient mice exposed to conventional cigarette smoke (CS) or to the aerosol of a candidate MRTP, tobacco heating system (THS) 2.2. In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS exposure was assessed. Engaging a systems toxicology approach, exposure effects were investigated using physiology and histology combined with transcriptomics, lipidomics, and proteomics. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function and alveolar damage). Atherogenic effects of CS exposure included altered lipid profiles and aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS, 29.9?mg/m3) neither induced lung inflammation or emphysema nor did it consistently change the lipid profile or enhance the plaque area. Cessation or switching to THS2.2 reversed the inflammatory responses and halted progression of initial emphysematous changes and the aortic plaque area. Biological processes, including senescence, inflammation, and proliferation, were significantly impacted by CS but not by THS2.2 aerosol. Both, cessation and switching to THS2.2 reduced these perturbations to almost sham exposure levels. In conclusion, in this mouse model cessation or switching to THS2.2 retarded the progression of CS-induced atherosclerotic and emphysematous changes, while THS2.2 aerosol alone had minimal adverse effects.
Project description:Cigarette smoke (CS) imposes a strong oxidative burden on exposed tissues resulting in a severely disturbed oxidant/antioxidant balance, which in the context of chronic exposure is assumed to be a key contributor to CS-related diseases. Because of its emerging central role in orchestrating the general cellular antioxidant response, the pathway leading to the activation of the transcription factor Nrf2 has received mounting attention over the past decade in investigations aimed at elucidating CS-induced patho-physiological mechanisms. To comprehensively characterize the impact of Nrf2 in acute and sub-chronic smoking scenarios, Nrf2 knock-out mice and their wildtype ICR littermates were exposed to either ambient air (sham exposure) or to one of three doses of CS for up to 5 months with two post-exposure endpoints of 1 and 13 days. The lungs of the mice were monitored for transcriptomic changes on a genome-wide level. 110 samples from 28 different groups are analyzed. For each group there are 4 replicates, besides two groups with only 3 replicates. Group parameteres are: genotype (WT, KN), treatment (sham, smoke), dosage of smoke treatment (low, medium, high), time of smoke treatment (1 day, 2 month, 5 month, 5 month + 1 day recovery, 5 month + 13 days recovery)
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:We have investigated the effects of cigarette smoke exposure in three different strains of mice. DBA/2 and C57Bl/6J are susceptible to smoke and develop different lung changes in response to chronic exposure, while ICR mice are resistant to smoke and do not develop emphysema. The present study was carried out to determine early changes in the gene expression profile of mice exposed to cigarette smoke with either a susceptible or resistant phenotype.
Project description:Cigarette smoking causes serious diseases, including lung cancer, heart disease, and emphysema. While cessation remains the most effective approach to minimize smoking-related disease, alternative non-combustible tobacco-derived nicotine containing products may reduce disease risks among those unable or unwilling to quit. E-vapor aerosols typically contain significantly lower levels of smoke-related harmful and potentially harmful constituents; however, health risks of long-term inhalation exposures are unknown. We designed a 7-month inhalation study in C57BL/6 mice to evaluate long-term respiratory toxicity of e-vapor aerosols compared to cigarette smoke and to assess the impact of smoking cessation or switching to an e-vapor product after 3 months of exposure to 3R4F cigarette smoke (CS). There were no significant changes in in-life observations (body weights, clinical signs) in e-vapor groups compared to the Sham Control. The 3R4F CS group showed reduced respiratory function during exposure and had lower body weight and showed transient signs of distress post-exposure. Following 7 months of exposure, e-vapor aerosols resulted in no or minimal increase in pulmonary inflammation, while exposure to 3R4F CS led to impairment of lung function and caused marked lung inflammation and emphysematous changes. Biological changes observed in the Switching group were similar to the Cessation group. 3R4F CS exposure dysregulated lung and nasal tissue transcriptome, while these molecular effects were substantially lower in the e-vapor group. Results from this study demonstrate that in comparison with 3R4F CS, e-vapor aerosols induce substantially lower biological responses including pulmonary inflammation and emphysema, and that complete switching from CS to e-vapor products significantly reduces biological changes associated with cigarette smoke in C57BL/6 mice.
Project description:Chronic obstructive pulmonary disease (COPD) is characterized by a progressive decline in lung function, caused by exposure to exogenous particles, mainly cigarette smoke (CS). COPD pathogenesis is initiated and perpetuated by an abnormal CS-induced inflammatory response of the lungs, involving both innate and adaptive immunity. Specifically, B cells organized in iBALT structures, as well as macrophages, accumulate in the lungs and contribute to CS-induced emphysema, but the mechanisms thereof remain unclear. Here, we demonstrate that B cell-deficient mice are significantly protected against CS-induced emphysema. Chronic CS exposure led to increased lung compliance, total lung capacity, and mean linear chord length in WT, but not B cell-deficient mice, associated with an increased size and number of iBALT structures. The increased accumulation of macrophages around iBALT and in emphysematous alveolar areas in CS-exposed WT mice coincided with upregulated MMP12 expression. In vitro co-culture experiments using B cells and macrophages demonstrated that B cell-derived IL-10 drives macrophage activation and MMP12 upregulation. In summary, B cell function in iBALT formation in CS-induced emphysema provides a new innovative mechanism, which could be explored as a target for therapeutic intervention in COPD patients.