Project description:Although smoking cessation shows clear cardiovascular risk benefits, lung-related disease risk remains higher in former smokers than in never smokers. To better understand the factors involved in this phenomenon, ApoE-/- mice were exposed to mainstream cigarette smoke (CS) or a smoking cessation-mimicking protocol for up to six months. Analysis of bronchoalveolar lavage fluid (BALF) from CS-exposed ApoE-/- mice revealed the presence of high concentrations of mediators involved in functions ranging from inflammation to cell proliferation and tissue remodeling. Gene expression levels for many analytes found elevated in BALF were also increased in lung tissue, indicating that the inflammatory response was the result of local tissue activation and the contribution of recruited inflammatory cells. Gene set enrichment analysis (GSEA) of expression data from lungs of CS-exposed mice showed activation of pathways involved in cell proliferation and tissue remodeling and a progressive deactivation upon smoke exposure cessation. Distinct activation patterns of inflammation, complement, and xenobiotic metabolism pathways were found in nasal epithelium and lung parenchyma during CS exposure and smoking cessation. Exposure of ApoE-/- mice to CS for up to 6 months induced adaptive and inflammatory responses in the respiratory tract that were partially deactivated upon cessation. We were able to reveal molecular perturbations accompanying these changes during CS exposure and cessation. Differential CS-mediated responses of pulmonary and nasal tissues reflect common mechanisms but also the varying degrees of epithelial functional specialization along the respiratory tract. These findings provide novel clues for the identification of markers of COPD progression.
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:Production of cephalosporin precursors with recombinant strains of Penicillium chrysogenum has improved the economics and reduced the environmental impact of industrial cephalosporin production. The engineered P. chrysogenum strains used in these processes express heterologous enzymes that convert the intermediate acyl-6-aminopenicillanic acid into different tailor-made compounds. Activation of the cephalosporin side-chain precursor to its corresponding CoA thioester is an essential step for its incorporation into the β-lactam backbone. To identify the acyl-CoA ligase involved in activation of adipic acid, a frequently used cephalosporin side-chain precursor, we searched the genome of P.chrysogenum for putative structural genes encoding acyl-CoA ligases. Chemostat-based transcriptome analysis was then used to identify the one presenting the highest expression level when cells were grown in the presence of adipic acid. Deletion of the gene renamed aclA, led to a 32% decreased specific rate of adipic acid consumption and a three-fold reduction of adipoyl-6-aminopenicillanic acid levels in chemostat cultures of P. chrysogenum, but did not affect penicillin production. After cloning the gene and overexpressing it in Escherichia coli, its purified protein product was shown to have adipoyl-CoA ligase, but no phenylacetyl-CoA ligtase activity. Finally, by fusing the gene to a sequence encoding cyan fluorescent protein, the resulting fusion protein localized to microbodies, which indicates that activation of the side-chain precursor adipic acid takes place in this compartment, where also the subsequent acyltransferase step takes place. Identification and functional characterization of this adipoyl-CoA ligtase gene may aid in developing future metabolic engineering strategies for improving the production of different cephalosporins.
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: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: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.
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 lung tissue.