Project description:Gemcitabine treatment shifts the intestinal microbiota of PC mice towards an inflammatory profile which may worsen mucositis and side effects observed upon chemotherapy. We explored the effect of a specific probiotics blend administered, with or without gemcitabine treatment, to PC xenografted mice.
Project description:We found that mainstream cigarette smoking (4 cigarettes/day, 5 days/week for 2 weeks using Kentucky Research Cigarettes 3R4F) resulted in >20% decrease in the percentage of normal Paneth cell population in Atg16l1 T300A mice but showed minimal effect in wildtype littermate control mice, indicating that Atg16l1 T300A polymorphism confers sensitivity to cigarette smoking-induced Paneth cell damage. We performed cohousing experiments to test if Paneth cell phenotype is horizontally transmissible as is microbiota. Atg16l1 T300A and littermate controls that were exposed to cigarette smoking were used as microbiota donors, and these donor mice were exposed to smoking for 2 weeks prior to cohousing. Separate groups of Atg16l1 T300A and littermate controls that were not exposed to cigarette smoking were used as microbiota recipients. The microbiota recipients were co-housed with microbiota donors of the same genotype for 4 weeks, during this period the donors continued to be exposed to cigarette smoking. Cigarette smoking was performed using smoking chamber with the dosage and schedule as described above. At the end of the experiment, the fecal microbiota composition was analyzed by 16S rRNA sequencing.
Project description:Background: Epigenetics is involved in various human diseases. Smoking is one of the most common environmental factors causing epigenetic changes. The DNA methylation changes and mechanisms after quitting smoking have not yet been defined. The present study examined the changes in DNA methylation level before and after short-term smoking cessation and explored the potential mechanism. Methods: Whole blood and clinical data were collected in 8 patients before and after short-term smoking cessation, DNA methylation was assessed, and differentially methylated sites were analyzed, followed by a comprehensive analysis of the differentially methylated sites with clinical data. GO/KEGG enrichment and protein-protein interaction (PPI) network identified the hub genes. The differentially methylated sites were detected by GEO2R between former smoking and current smoking in GSE50660 from the GEO database. Then, a Venn analysis was carried out using the differentially methylated sites. GO/KEGG enrichment analysis was performed on the genes corresponding to the common DNA methylation sites, the PPI network was constructed, and hub genes were predicted. The enriched genes associated with the cell cycle were selected, and the gene expression was analyzed in pan-cancer based on the TCGA database. Results: Most of the DNA methylation levels were decreased after short-term smoking cessation; a total of 694 hypermethylated CPG sites and 3184 hypomethylated CPG sites were identified. The DNA methylation levels altered according to the clinical data (body weight, expiratory, and tobacco dependence score). Enrichment analysis, construction of PPI network, and pan-cancer analysis suggested that smoking cessation may be involved in various biological processes. Conclusions: Smoking cessation leads to epigenetic changes, mainly observed in the decline of most DNA methylation levels. Bioinformatics further identified the biologically relevant changes after short-term smoking cessation.
Project description:RNA was obtained longitudinally from normal nasal epithelium of smokers who have quit smoking over 6 months period. Statistical analysis of gene expression data identified genes differentially expressed with short-term smoking cessation and categorized the kinetics of of these genes in different biological functions with different dynamics following smoking cessation.
Project description:Cigarette smoking is one of the largest causes of preventable death worldwide. Smoking behaviors, including age at smoking initiation (ASI), smoking dependence (SD), and smoking cessation (SC), are all complex phenotypes determined by both genetic and environmental factors as well as their interactions. To identify susceptibility loci for each smoking phenotype, numerous studies have been conducted, with approaches including genome-wide linkage scans, candidate gene-based association analysis, and genome-wide association study (GWAS). Therefore, we conducted an exome-wide association study to identify new susceptibility loci for the risk of nicotine dependence in African-American populations.
Project description:Cigarette smoking is one of the largest causes of preventable death worldwide. Smoking behaviors, including age at smoking initiation (ASI), smoking dependence (SD), and smoking cessation (SC), are all complex phenotypes determined by both genetic and environmental factors as well as their interactions. To identify susceptibility loci for each smoking phenotype, numerous studies have been conducted, with approaches including genome-wide linkage scans, candidate gene-based association analysis, and genome-wide association study (GWAS). Therefore, we conducted an exome-wide association study to identify new susceptibility loci for the risk of nicotine dependence in European-American populations.
Project description:DNA methylation is an epigenetic event whose pattern is altered frequently in a wide variety of human diseases. Smoking affects DNA methylation possibly leading to abnormal expression of a broad spectrum of genes which in turn may result to the various side effects and diseases associated with smoking. The long term effects of smoking have been widely studied but the mechanism(s) by which those effects may be reversible by smoking cessation are not clearly understood. Here, we conducted an epigenome-wide association study in peripheral-blood DNA in 464 individuals who were current, former and never-smokers. We identified 15 distinct loci (10 of which were novel) where DNA methylation was reduced in smokers and was reversed (but did not reach non-smoking levels) upon smoking cessation within 12 weeks. Although the functional impact of this reversal of DNA methylation is still not understood, this study illustrates the potential of epigenomics to provide insights into mechanisms of environmental and lifestyle exposures, and to suggest new avenues for clinical intervention
Project description:DNA methylation is an epigenetic event whose pattern is altered frequently in a wide variety of human diseases. Smoking affects DNA methylation possibly leading to abnormal expression of a broad spectrum of genes which in turn may result to the various side effects and diseases associated with smoking. The long term effects of smoking have been widely studied but the mechanism(s) by which those effects may be reversible by smoking cessation are not clearly understood. Here, we conducted an epigenome-wide association study in peripheral-blood DNA in 464 individuals who were current, former and never-smokers. We identified 15 distinct loci (10 of which were novel) where DNA methylation was reduced in smokers and was reversed (but did not reach non-smoking levels) upon smoking cessation within 12 weeks. Although the functional impact of this reversal of DNA methylation is still not understood, this study illustrates the potential of epigenomics to provide insights into mechanisms of environmental and lifestyle exposures, and to suggest new avenues for clinical intervention Bisulfite converted DNA from the 464 samples were hybridized to the Illumina Infinium HumanMethylation450 BeadChip