Project description:A complete understanding of how environmental carcinogenic exposures promote cancer formation is lacking. Over 70 years ago, tumour formation was proposed to occur in a two step process: an initiating step which induces mutations in normal tissue, followed by a promoter step which triggers cancer development. Recent evidence has revealed healthy human tissue contains a patchwork of clones harbouring oncogenic mutations.This led us to hypothesise that environmental particulate matter measuring PM2.5, known to be associated with lung cancer risk, might promote lung cancer by acting on pre-existing cells harbouring oncogenic mutations in normal lung tissue. Here we use a combination of WGS and RNA-seq of mouse tumours from pollution-exposed mice to examine the impact of particulate matter on mutagenesis and gene expression respectively.
Project description:We analyzed the ability of particulate matter (PM) and chemicals adsorbed onto it to induce diverse gene expression profiles in subjects living in two regions of the Czech Republic differing in levels and sources of the air pollution. A total of 312 samples from polluted Ostrava region and 154 control samples from Prague were collected in winter 2009, summer 2009 and winter 2010. The highest concentrations of air pollutants were detected in winter 2010 when the subjects were exposed to: PM of aerodynamic diameter < 2.5 µm (PM2.5) (70 vs. 44.9 µg/m3); benzo[a]pyrene (9.02 vs. 2.56 ng/m3) and benzene (10.2 vs. 5.5 µg/m3) in Ostrava and Prague, respectively. Global gene expression analysis of total RNA extracted from leukocytes was performed using Illumina Expression BeadChips microarrays. The expression of selected genes was verified by quantitative real-time PCR (qRT-PCR). Gene expression profiles differed by locations and seasons. Despite lower concentrations of air pollutants a higher number of differentially expressed genes and affected KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways was found in subjects from Prague. In both locations immune response pathways were affected, in Prague also neurodegenerative diseases-related pathways. Over-representation of the latter pathways was associated with the exposure to PM2.5. The qRT-PCR analysis showed a significant decrease in expression of APEX, ATM, FAS, GSTM1, IL1B and RAD21 in subjects from Ostrava, in a comparison of winter 2010 and summer 2009. In Prague, an increase in gene expression was observed for GADD45A and PTGS2. In conclusion, high concentrations of pollutants in Ostrava were not associated with higher number of differentially expressed genes, affected KEGG pathways and expression levels of selected genes. This observation suggests that chronic exposure to air pollution may result in reduced gene expression response with possible negative health consequences.
Project description:Atopic dermatitis is increasing worldwide, correlating with air pollutions. Various organic components of pollutants activate transcription factor AhR (aryl-hydrocarbon receptor). We have established AhR-CA mice, whose keratinocytes express constitutive-active AhR, and these mice developed atopic dermatitis-like frequent scratching and allergic inflammation. In this study we performed ChIP-seq analyses and identified keratinocyte-specific AhR target genes, including inflammatory cytokines Tslp and IL33, and neurotrophic factor Artemin. While AhR-CA mice exhibited epidermal hyperinnervation and alloknesis leading to hypersensitivity to pruritus, blockade of Artemin alleviated these phenotypes. AhR-CA mice showed scratching-induced barrier insufficiency and enhanced sensitization to epicutaneously-applied antigens, recapitulating human atopic dermatitis. Consistently, AhR activation and Artemin expression was detected in the epidermis of atopic dermatitis patients and keratinocytes exposed to air pollutants. Thus, AhR in keratinocytes senses the environmental stimuli and responds to them through moderating inflammation. We propose a mechanism in which air pollution induces atopic dermatitis through AhR activation.
Project description:Air pollutants including particulate matter (PM) and chemicals adsorbed onto PM pose a serious threat to human health. In this study, we analyzed the ability of PM to induce diverse gene expression profile modulation after chronic exposure in subjects living in two regions of the Czech Republic differing in levels and sources of the air pollution. We also considered impact of different seasonal conditions on concentrations and compositions of PM. Blood samples of 312 subjects from polluted Ostrava city and 154 controls from Prague city were collected in winter 2009, summer 2009 and winter 2010. The highest concentrations of air pollutants were detected in winter 2010 when the subjects were exposed to: PM of aerodynamic diameter < 2.5 M-BM-5m (70 vs. 44.9 M-BM-5g/m3); benzo[a]pyrene (9.02 vs. 2.56 ng/m3) and benzene (10.2 vs. 5.5 M-BM-5g/m3) in Ostrava and Prague, respectively. Global gene expression analysis of total RNA extracted from leukocytes was performed using whole genome microarrays (Illumina). The expression of selected genes was verified by quantitative real-time PCR (qRT-PCR). Despite lower concentrations of air pollutants we found a higher number of differentially expressed genes and affected KEGG pathways in subjects from Prague. In both locations we observed differences between seasons. The qRT-PCR analysis showed a significant decrease in expression of APEX, ATM, FAS, GSTM1, IL1B and RAD21 in subjects from Ostrava, in a comparison of winter 2010 and summer 2009. In Prague, an increase in gene expression was observed for GADD45A and PTGS2. In conclusion, high concentrations of pollutants in Ostrava do not increase the number of differentially expressed genes. This may be explained by adaption of humans to chronic exposure to air pollution. Total RNA was extracted from leukocytes of total of 154 control subjects and 312 subjects exposed to heavy air pollution. The samples were collected in three seasons (winter 2009, summer 2009, winter 2010) with different levels of air pollution. Most of the subjects were sampled repeatedly; however, some of them joined the study in summer 2009 or winter 2010.
Project description:To investigate the cellular responses induced by air pollution exposures, we performed genome-wide gene expression microarray analysis using whole blood RNA sampled at three time-points across the work weeks of 63 non-smoking employees in the trucking industry. Our objective was to identify the genes and gene networks differentially activated in response to micro-environmental measures of occupational exposure to three pollutants: PM2.5 (particulate matter ≤ 2.5 microns in diameter) and elemental carbon (EC) and organic carbon (OC).