Project description:Background and Aims: The impact of cigarette smoke on inflammatory bowel disease has been established by a large number of epidemiological, clinical, and preclinical studies. Exposure to cigarette smoke is associated with a higher risk of developing Crohn’s disease but is inversely correlated with the development, disease risks, progression, and relapse rate of ulcerative colitis. Few mechanistic studies have investigated the effect of cigarette smoke on intestinal inflammation and microbial composition. Methods: Three groups of mice were exposed to three different concentrations of cigarette smoke for a total of 4 weeks, including 5 days of dextran sulfate sodium treatment to induce colitis and a 7-day recovery period. A comprehensive and integrated comparative analysis of the global colon transcriptome and microbiome, as well as classical endpoints, was performed. Results: Cigarette smoke exposure significantly decreased the severity induced colitis. Colon transcriptome analysis revealed that cigarette smoke downregulated specific pathways in a concentration-dependent manner, affecting both the inflammatory state and composition of the gut microbiome. Metagenomics analysis demonstrated that cigarette smoke can modulate dextran sulfate sodium-induced dysbiosis of specific bacterial genera, contributing to resolve the inflammation or accelerate recovery. Conclusions: Cigarette smoke alters gut microbial composition and reduces inflammatory responses in a concentration-dependent manner. The present study lays the foundation for investigating potential molecular mechanisms responsible for the attenuation of colitis by cigarette smoke.
Project description:Gene expression data on wild-type and Rora mutant mice exposed to room air and smoke. The results provide a general insight into the relationship of Rora to known DNA damage response pathways and its role in cigarette smoke-induced airspace enlargement. This dataset includes 4 wild-type mice exposed to room air, 4 wild-type mice exposed to cigarette smoke and 4 Rora mutant mice exposed to cigarette smoke.
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: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:Introduction: Prenatal and postnatal cigarette smoke exposure enhances the risk of developing asthma. Despite this as well as other smoking related risks, 11% of women still smoke during pregnancy. We hypothesized that cigarette smoke exposure during prenatal development generates long lasting differential methylation altering transcriptional activity that correlates with disease. Methods: In a house dust mite (HDM) model of allergic airway disease, we measured airway hyperresponsiveness (AHR) and airway inflammation between mice exposed prenatally to cigarette smoke (CS) or filtered air (FA). DNA methylation and gene expression were then measured in lung tissue. Results: We demonstrate that HDM-treated CS mice develop a more severe allergic airway disease compared to HDM-treated FA mice including increased AHR and airway inflammation. While DNA methylation changes between the two HDM-treated groups failed to reach genome-wide significance, 99 DMRs had an uncorrected p-value < 0.001. 6 of these 99 DMRs were selected for validation, based on the immune function of adjacent genes, and only 2 of the 6 DMRs confirmed the bisulfite sequencing data. Additionally, genes near these 6 DMRs (Lif, Il27ra, Tle4, Ptk7, Nfatc2, and Runx3) are differentially expressed between HDM-treated CS mice and HDM-treated FA mice. Conclusions: Our findings confirm that prenatal exposure to cigarette smoke is sufficient to modify allergic airway disease, however, it is unlikely that specific methylation changes account for the exposure-response relationship. These findings highlight the important role in utero cigarette smoke exposure plays in the development of allergic airway disease. Lung DNA methylation profiles of mice exposed in utero to cigarette smoke (CS) then treated with house dust mite (HDM, n = 8) or saline (n = 6), or exposed in utero to filtered air (FA) then treated with HDM (n = 9) or saline (n = 6)
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. Experiment Overall Design: Three strains of mice were exposed to smoke from three cigarette/day, 5d/wk for 4 weeks. Microarray analysis was carried out on total RNA extracted from the lung utilizing the Affymetrix platform.
Project description:How LTβR-signalling drives chronic tissue damage particularly in the lung, which mechanisms regulate this process, and whether LTβR-blockade might be of therapeutic value has remained unclear. To study the mechanisms underlying LTβR-inhibition, a transcriptional analysis was performed on lung tissue from B6 mice exposed to cigarette smoke for 6 months and treated therapeutically with LTβR-Ig from 4 to 6 months compared to mice exposed to cigarette smoke for 6 months and treated with control Ig from 4 to 6 months and filtered air control. Single-cell RNA-Seq identified 24 distinct cell populations across >20,000 cells in lungs with distinct changes occurring upon cigarette smoke exposure and LTβR-Ig treatment.
Project description:Single cell RNA-sequencing (scRNAseq) of lung immune cells from mice exposed to room air or cigarette smoke, infected with influenza A virus. Room air saline controls are also included. This analysis facilitates a comparison of cigarette smoke-associated changes to the pulmonary immune environment at the level of individual leukocytes and stromal cells.