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:To identify biosignatures that describe these lifestyle susceptibility factors, we performed parallel exposures of regular weight (RW) C57BL/6 and diet-induced obese (DIO) C57BL/6 mice to cigarette smoke, either mainstream (MS) or sidestream (SS), mimicking both the smoker and environmental exposure through second-hand smoke, respectively. Transcriptional responses were measured by global microarray analysis of lung tissue. Groups (N=8 biological replicates) of RW and DIO C57BL/6 mice (15-weeks old at start of exposures) were exposed to either filtered air (sham controls, SC), mainstream (MS) or sidestream (SS) cigarette smoke by nose-only inhalation exposure for 5 hr/day for a total of eight exposures over two weeks as follows: 5 consecutive days of exposure, followed by 2 days with no exposure, then three days of exposure, with necropsies occurring the day following the last exposure.
Project description:To identify biosignatures that describe these lifestyle susceptibility factors, we performed parallel exposures of regular weight (RW) C57BL/6 and diet-induced obese (DIO) C57BL/6 mice to cigarette smoke, either mainstream (MS) or sidestream (SS), mimicking both the smoker and environmental exposure through second-hand smoke, respectively. Transcriptional responses were measured by global microarray analysis of lung tissue.
Project description:Cigarette smoke (CS) is an aerosol containing more than 6,000 chemicals and one of the risk factor in the development of chronic inflammatory lung disease. To evaluate biological effect of CS on human respiratory tract, organotypic bronchial epithelial cultures can be used to replicate in vivo tissue conditions. The MucilAir organotypic bronchial epithelial cultures were exposed to mainstream aerosols from the 3R4F cigarette and a novel tobacco vapor product (NTV), which we recently developed, using a Vitrocell exposure system. This system consists of three steps: the generation of CS, dilution, and exposure to an air-liquid interface cultured cells in a specially designed module. This exposure scenario mimics CS exposure in the human airway (i.e. direct aerosol exposure to the apical surface of air-liquid interface-cultured cells), We found a dose-dependent increase in the number of differentially expressed genes following 3R4F cigarette smoke exposure, compared with expression in air-exposed controls. In contrast, no changes were detected following exposure to NTV vapor.
Project description:To identify biosignatures that describe these lifestyle susceptibility factors, we performed parallel exposures of regular weight (RW) C57BL/6 and diet-induced obese (DIO) C57BL/6 mice to cigarette smoke, either mainstream (MS) or sidestream (SS), mimicking both the smoker and environmental exposure through second-hand smoke, respectively. Transcriptional responses were measured by global microarray analysis of heart tissue. Groups (N=6-8 biological replicates) of RW and DIO C57BL/6 mice (15-weeks old at start of exposures) were exposed to either filtered air (sham controls, SC), mainstream (MS) or sidestream (SS) cigarette smoke by nose-only inhalation exposure for 5 hr/day for a total of eight exposures over two weeks as follows: 5 consecutive days of exposure, followed by 2 days with no exposure, then three days of exposure, with necropsies occurring the day following the last exposure.
Project description:The objective of the study was to characterize the toxicity due to sub-chronic inhalation of test atmospheres from the heat not burn modified risk tobacco product (MRTP) - Tobacco Heating System version 2.2 (THS2.2) and to compare it to the toxicity inherent to the inhalation of mainstream smoke (MS) from the Reference Cigarette 3R4F (University_of_Kentucky, 2003). The 90-day nose-only inhalation study on Sprague-Dawley rats was performed according to the Organization for Economic Co-operation and Development (OECD) Test Guideline 413 (OECD, 2009), with special emphasis on histopathology of the respiratory tract, lung inflammation and additional systems toxicology-based assessment using transcriptomics. Animals were exposed to mainstream smoke from 3R4F reference cigarettes or THS2.2 mainstream aerosol at 3 target nicotine concentrations. The exposure regimen consisted of 6 hours a day, 5 days per week for 13 weeks, followed by 42 days recovery period. Exposure-related changes such as increased blood neutrophil count, decreased blood lymphocyte count, increased activity of alkaline phosphatase in serum and decreased cholesterol and glucose in serum were observed in 3R4F and THS2.2 exposed animals. Reduction in respiratory minute volume was significantly less pronounced in THS2.2 as compared to 3R4F-exposed groups. Histopathological findings in the respiratory tract including epithelial cell hyperplasia, squamous metaplasia, atrophy and accumulation of pigmented alveolar macrophages were significantly lower in THS2.2 than in 3R4F exposed groups. The degree of lung inflammation as indicated by accumulation of immune cells and pro-inflammatory and chemotactic cytokines in bronchioalveolar lavage fluid were significantly lower in THS2.2 as compared to 3R4F exposed groups. Transcriptomics data obtained from nasal epithelium and lung parenchyma showed concentration-dependent gene expression changes following 3R4F exposure that were much less pronounced in the THS2.2-exposed groups. In summary, the data indicates that the aerosol from THS2.2 did not cause additional toxicity as compared to the smoke from the 3R4F conventional cigarette. The toxicity on respiratory tract organs in THS2.2 exposed animals was much lower than in the rats exposed to 3R4F reference cigarette. Overall, the changes observed following exposure to THS2.2 can be considered mild and are very similar to previously published effects caused by nicotine only exposure at similar test atmosphere concentrations.
Project description:COPD is a disorder characterized by the progressive development of airflow limitation that is not fully reversible. Cigarette smoke has been generally accepted as the most important of many risk factors for the development of COPD. We used microarray technology to perform comprehensive gene expression profiling of smoke exposure and cessation effects in mouse muscle tissue. Mice received nose-only exposure of 4% mainstream cigarette smoke or air (sham exposure) for 2 hours/day, 5 days/week for 2, 12 or 24 weeks. Mice undergoing smoke cessation received cigarette smoke exposure for 12 weeks, and then sham exposure for 12 weeks.
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.