Project description:Background: How prenatal smoke exposure affects DNA methylation leading to atopic disorders remains to be addressed. Epigenetic biomarkers informative of prenatal smoke exposure and atopic disorders are wanting. Since most children suffering from atopic dermatitis (AD) continue to develop asthma later in life, we explored whether prenatal smoke exposure e induces DNA methylation and searched for predictive epigenetic biomarkers for smoke related atopic disorders. Methods: Methylation differences associated with smoke exposure were screened by Illumina methylation panel for children from the Taiwan birth panel study cohort initially. Information about development of atopic dermatitis (AD) and risk factors were collected. Cord blood cotinine levels were measured to represent prenatal smoke exposure. CpG loci that demonstrated a statistically significant difference in methylation were validated by methylation-dependent fragment separation (MDFS). Differential methylation in three genes (TSLP, GSTT1, and CYB5R3) was identified through the screen and their functions were investigated. Results: Among these, only thymic stromal lymphopoietin (TSLP) gene displayed significant difference in promoter methylation percentage after being validated by MDFS (p=0.029). TSLP gene was further investigated in a larger sample of 92 children from the cohort. Methylation status of the TSLP 5′-CpG island (CGI) was found to be significantly associated with prenatal smoke exposure (OR=3.59, 95%CI=1.49-8.64; cotinine level 0.10 ng/ml, sensitivity= 77%; specificity = 61%) and with AD (OR=4.77, 95%CI=1.47-15.53). The degree of TSLP 5′CGI methylation inversely correlated with TSLP protein expression levels (per unit: β=-6.69 ng/ml; 95% CIs, -12.80~-0.59; p=0.032). Conclusions: The effect of prenatal tobacco smoke exposure on the risk for AD may be mediated through DNA methylation. Cord blood methylated TSLP 5′CGI may be a potential epigenetic biomarker for environmentally-related atopic disorders.
Project description:Background: How prenatal smoke exposure affects DNA methylation leading to atopic disorders remains to be addressed. Epigenetic biomarkers informative of prenatal smoke exposure and atopic disorders are wanting. Since most children suffering from atopic dermatitis (AD) continue to develop asthma later in life, we explored whether prenatal smoke exposure e induces DNA methylation and searched for predictive epigenetic biomarkers for smoke related atopic disorders. Methods: Methylation differences associated with smoke exposure were screened by Illumina methylation panel for children from the Taiwan birth panel study cohort initially. Information about development of atopic dermatitis (AD) and risk factors were collected. Cord blood cotinine levels were measured to represent prenatal smoke exposure. CpG loci that demonstrated a statistically significant difference in methylation were validated by methylation-dependent fragment separation (MDFS). Differential methylation in three genes (TSLP, GSTT1, and CYB5R3) was identified through the screen and their functions were investigated. Results: Among these, only thymic stromal lymphopoietin (TSLP) gene displayed significant difference in promoter methylation percentage after being validated by MDFS (p=0.029). TSLP gene was further investigated in a larger sample of 92 children from the cohort. Methylation status of the TSLP 5′-CpG island (CGI) was found to be significantly associated with prenatal smoke exposure (OR=3.59, 95%CI=1.49-8.64; cotinine level 0.10 ng/ml, sensitivity= 77%; specificity = 61%) and with AD (OR=4.77, 95%CI=1.47-15.53). The degree of TSLP 5′CGI methylation inversely correlated with TSLP protein expression levels (per unit: β=-6.69 ng/ml; 95% CIs, -12.80~-0.59; p=0.032). Conclusions: The effect of prenatal tobacco smoke exposure on the risk for AD may be mediated through DNA methylation. Cord blood methylated TSLP 5′CGI may be a potential epigenetic biomarker for environmentally-related atopic disorders. The buffy coat and plasma samples were separated and stored at −80°C. DNA (100 ng-500 ng) was extracted from cord white blood cells. Microarrays have been performed to investigate fourteen samples, which were classified as two groups according to cotinine exposure dosage (7 versus 7 : high exposure verses low exposure).
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:This project evaluates the effects of tobacco smoke exposure (TSE) on the pediatric lung microbiome in critically ill children. The impact of TSE on the airway microbiome of critically ill, mechanically ventilated pediatric patients will be determined by through clinical outcomes and analysis of urinary and plasma metabolomes to identify other environmental exposures contributing to the alteration of the pediatric microbiome.
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:40 current smokers and 40 age- and gender- matched never smokers underwent buccal biopsies.The study had four objectives: (a) to define the effects of smoking on the transcriptome of oral epithelial cells; (b) to determine if any of the effects of tobacco smoke on the transcriptome are gender-dependent; (c) to compare the effects of tobacco smoke exposure on the transcriptome in oral v. bronchial epithelium and (d) to identify agents with the potential to suppress the effects of tobacco smoke on the transcriptome. We used microarrays to provide new insights into the carcinogenic effects of tobacco smoke and offer insights that may prove useful in developing preventive strategies.
Project description:Gene expression patterns were assessed in normal human bronchial epithelial (NHBE) cells exposed to cigarette smoke from a reference cigarette (2R4F, University of Kentucky) and a typical American brand of "light" cigarettes ("Lights") in order to develop a better understanding of the genomic impact of tobacco exposure, which can ultimately define biomarkers that discriminate tobacco-related effects and outcomes in a clinical setting. NHBE cells were treated with whole cigarette smoke for 15 minutes and alterations to the transcriptome assessed at 2, 4, 8 and 24 hours post-exposure using high-density oligonucleotide microarrays. Keywords: time course, cigarette smoke exposure
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:There is growing evidence that paternal pre-conception cigarette smoke (CS) exposure is associated with increased risk of behavioral disorders and cancer in offspring. To characterize the effects of CS exposure on the sperm epigenome and offspring neurodevelopment, we investigated the impact of pre-conception paternal CS exposure on mouse sperm DNA methylation and gene expression in offspring. We further investigated the role of oxidative stress on sperm epigenetic changes using a mouse model (Nrf-/-) with impaired antioxidant capacity. Lastly, we evaluated the capacity for sperm DNA methylation to recover following removal of CS for 1-5 spermatogenic cycles (28-171 days). We found that smoking significantly impacts sperm DNA methylation as well as DNA methylation and gene expression in offspring. These changes were largely recapitulated in Nrf-/- mice independent of smoke exposure. Recovery experiments indicated that about half of differentially methylated regions returned to normal within 28 days of removal from smoke, however additional recovery following longer periods was not observed. Thus, we present strong evidence that cigarette smoke exposure induces paternally mediated, heritable epigenetic changes. Parallel studies performed in Nrf-/- mice provide evidence for oxidative stress as the predominant underlying mechanism for smoke-induced epigenetic changes to sperm as well as changes in the offspring of smoke-exposed sires. Lastly, recovery experiments indicate that while many epigenetic changes are corrected following removal from smoke exposure, aberrant methylation persists at a significant number of regions even after five spermatogenic cycles
Project description:There is growing evidence that paternal pre-conception cigarette smoke (CS) exposure is associated with increased risk of behavioral disorders and cancer in offspring. To characterize the effects of CS exposure on the sperm epigenome and offspring neurodevelopment, we investigated the impact of pre-conception paternal CS exposure on mouse sperm DNA methylation and gene expression in offspring. We further investigated the role of oxidative stress on sperm epigenetic changes using a mouse model (Nrf-/-) with impaired antioxidant capacity. Lastly, we evaluated the capacity for sperm DNA methylation to recover following removal of CS for 1-5 spermatogenic cycles (28-171 days). We found that smoking significantly impacts sperm DNA methylation as well as DNA methylation and gene expression in offspring. These changes were largely recapitulated in Nrf-/- mice independent of smoke exposure. Recovery experiments indicated that about half of differentially methylated regions returned to normal within 28 days of removal from smoke, however additional recovery following longer periods was not observed. Thus, we present strong evidence that cigarette smoke exposure induces paternally mediated, heritable epigenetic changes. Parallel studies performed in Nrf-/- mice provide evidence for oxidative stress as the predominant underlying mechanism for smoke-induced epigenetic changes to sperm as well as changes in the offspring of smoke-exposed sires. Lastly, recovery experiments indicate that while many epigenetic changes are corrected following removal from smoke exposure, aberrant methylation persists at a significant number of regions even after five spermatogenic cycles