Project description:In the present study, we investigate pulmonary transcriptional responses in mice following exposure in situ to ambient air in a heavily polluted urban environment. Mature C57BL/CBA male mice were caged in sheds located in an urban area near two working steel mills and a major highway in Hamilton, Ontario, Canada. Control mice were housed in the same environment but received only high-efficiency particle-filtered air. Whole lung tissues were collected from mice exposed for 3 weeks, 10 weeks or for 10 weeks followed by 6 weeks in the laboratory (16 weeks total). DNA microarrays were used to explore changes in pulmonary gene expression in mice breathing ambient air versus HEPA-filtered air. Transcriptional profiling revealed changes in the expression of genes implicated in the lipid droplet synthesis pathway (plin, dgat2, lpl, s3-12, agpat2), antioxidants (ucp1). We postulate that exposure to particulate matter adsorbed with polycyclic aromatic hydrocarbons triggers lipid droplet synthesis (holding depots for lipids and malformed/excess proteins tagged for degradation) in the lungs, which act to sequester particulates adsorbed with toxic chemicals. Increased lipid droplet synthesis could potentially lead to endogenous/stressor-induced synthesis of reactive oxygen species and activation of antioxidant mechanisms. Further investigation into the stimulation of lipid droplet synthesis in the lung in response to air pollution is warranted in order to better understand these mechanistic changes and the resulting health implications.
Project description:In the present study, we investigate pulmonary transcriptional responses in mice following exposure in situ to ambient air in a heavily polluted urban environment. Mature C57BL/CBA male mice were caged in sheds located in an urban area near two working steel mills and a major highway in Hamilton, Ontario, Canada. Control mice were housed in the same environment but received only high-efficiency particle-filtered air. Whole lung tissues were collected from mice exposed for 3 weeks, 10 weeks or for 10 weeks followed by 6 weeks in the laboratory (16 weeks total). DNA microarrays were used to explore changes in pulmonary gene expression in mice breathing ambient air versus HEPA-filtered air. Transcriptional profiling revealed changes in the expression of genes implicated in the lipid droplet synthesis pathway (plin, dgat2, lpl, s3-12, agpat2), antioxidants (ucp1). We postulate that exposure to particulate matter adsorbed with polycyclic aromatic hydrocarbons triggers lipid droplet synthesis (holding depots for lipids and malformed/excess proteins tagged for degradation) in the lungs, which act to sequester particulates adsorbed with toxic chemicals. Increased lipid droplet synthesis could potentially lead to endogenous/stressor-induced synthesis of reactive oxygen species and activation of antioxidant mechanisms. Further investigation into the stimulation of lipid droplet synthesis in the lung in response to air pollution is warranted in order to better understand these mechanistic changes and the resulting health implications. Mature male C57BL/6 x CBA F1 hybrid mice were exposed to either HEPA-filtered or ambient air in Hamilton, ON, Canada. Animals were exposed starting May 14, 2004 for 3 weeks (3wk), 10 weeks (10wk), or for 10 weeks followed by 6 weeks of recovery (16wk). Each treatment group consisted of five mice, for a total of 30 mice. Total RNA was isolated from a random section of the whole lung using TRIzol reagent (Invitrogen) and purified using the RNeasy Mini Kit (Qiagen). RNA quality was confirmed by UV spectrophotometry and using an Agilent Bioanalyzer. Total RNA (200 ng) from HEPA-filtered air or whole air-exposed mice and Universal Mouse Reference RNA (Stratagene) were used to synthesize double-stranded cDNA and cyanine-labelled cRNA according to the manufacturer's instructions (Agilent Linear Amplification Kits, Agilent Technologies). Biological samples were labelled with Cy5 dye while the commercially available Stratagene mouse reference RNA was labelled with Cy3 dye. At each of the three time points, ambient air-exposed samples and HEPA-filtered samples were hybridized to Agilent microarrays. Arrays were washed, and scanned on an Agilent G2505B scanner. Data were acquired using the Agilent Feature Extraction software version 9.5.3.1.
Project description:Over the last years, evidence has grown that exposure to air pollution, in addition to impairing lung function and health in individuals of all age, can be linked to negative effects in newborn when present during pregnancy. Data suggests that intrauterine exposure of fetuses (exposure of the mother to air pollution during pregnancy) in fact exerts a negative impact on lung development. However, the means by which exposure during pregnancy affects lung development, have not been studied in depth yet. In this study, we investigated alterations of the transcriptome of the developing lung in a mouse model of gestational and early-life postnatal exposure to urban PM2.5 (from Sao Paulo, Brazil).
Project description:We reported the gene expression profile of T47D cells treated with the organic extract of Particulate matter 2.5 (PM2.5) sampled next to the municipal solid waste incineration plant of Bologna city. Based on a air pollution distribution model that takes the incinaration plant as point source of emission, two sites were chosen to sample particulate matter near incineration plant: "FrulloEst" representing the maximum effect of the incineration plant, "Calamosco" representing the negative control of "FrulloEst" (minimun effect of incineration plant, same effect of other air pollution fonts). Another site, "Giardini Margherita", is chosen to sample the urban background air pollution. for each site sample collection was performed in winter and in summer season.
Project description:The neurotoxicity of air pollution is undefined for sex and APOE alleles. These major risk factors of Alzheimer’s disease (AD) were examined in mice given chronic exposure to nPM, a nano-sized subfraction of urban air pollution. In the cerebral cortex, female mice had two-fold more genes responding to nPM than males. Transcriptomic responses to nPM had sex-APOE interactions in AD-relevant pathways. Only APOE3 mice responded to nPM in genes related to Abeta deposition and clearance (Vav2, Vav3, S1009a). Other responding genes included axonal guidance, inflammation (AMPK, NFKB, APK/JNK signaling), and antioxidant signaling (NRF2, HIF1A). Genes downstream of NFKB and NRF2 responded in opposite directions to nPM. Nrf2 knockdown in microglia augmented NFKB responses to nPM, suggesting a critical role of NRF2 in air pollution neurotoxicity. These findings give a rationale for epidemiologic studies of air pollution to consider sex interactions with APOE alleles and other AD-risk genes.
Project description:Artificial light at night (ALAN) disrupts natural light-dark cycles, posing ecological challenges for wildli in urban areas. Here we investigated the efcts of ALAN on gene expression in the brain, liver, skin, and gonads of green anole lizards (Anolis carolinensis) whose urban populations are increasingly exposed to light pollution. To identify genetic pathways impacted by ALAN exposure we analysed expression of genes associated with circadian and metabolic regulation at midday, midnight and at midnight with artificial light. Difrential expression analysis revealed that clock-related genes (PER1, NR1D1, CRY2) were significantly altered in the brain, liver, and skin following ALAN treatment and genes involved in glucagon regulation (GCG) and lipid metabolism (NOCT) were difrentially expressed in the liver, indicating metabolic disruptions. Skin exhibited unique responses to ALAN suggesting that repair responses may be altered as genes related to cellular processes, such as wound healing, were upregulated under normal light and dark conditions. Our findings also show that ALAN disrupts core circadian genes, impacting physiological processes including hormone regulation, glucose homeostasis, and potentially reproductive cycles. This study provides the first transcriptomic evidence of the efcts of light pollution on green anoles, highlighting the need to preserve natural light cycles in urban habitats. An interactive online database developed for this study allows further exploration of gene expression changes, to promote research on artificial light-polluted environments.
Project description:Maternal exposure to particulate air pollution increases the incidence and severity of asthma in offspring, yet the mechanisms for this are unclear. Known susceptibility loci are a minor component of this effect. We interrogate a mouse allergic airway disease model to assess epigenetic associations between maternal air pollution exposure and asthma-like responses in offspring. Maternal air pollution exposure increased allergic airway disease severity in adult offspring associated with a suppressed transcriptomic response to allergen. Control progeny showed differential expression of 2842 genes across several important pathways, including the SMAD and TGFβR pathways, whilst air pollutant progeny showed an 80% reduction in differentially expressed genes and abrogation of many pathway associations. Whole genome CpG methylome analysis following allergen challenge detected differential methylation regions across the genome. Approximately 20% of differentially expressed genes were associated with differential methylation. Differentially methylated regions were markedly reduced in offspring of air pollution exposed mothers, and this was most evident in intronic regions and some transposable element classes. This study shows that allergic airways disease in adult offspring of PM2.5 exposed mothers had a markedly repressed transcriptomic response, a proportion of which was associated with identifiable changes in the lung’s methylome. The results point to an epigenetic contribution to the severity of asthma in offspring of mothers exposed to particulate air pollution.