The effect of S9 metabolic mix and carcinogens on global DNA methylation in TK6 cells <i>in vitro</i>.

<p>The table gives parameter estimates and standard errors for a random intercept model with chemicals and S9 as fixed effects.</p>*<p>Significant at α level of 0.05.</p

Global DNA methylation in TK6 cells per chemical dose in the absence of S9 metabolic mix.

<p>Global DNA methylation is expressed as a percentage of 5-methylcytosine versus the total number of cytosines present in the genome.</p><p>SD: Standard deviation,</p>*<p>standard deviation could not be calculated because sample replicates did not pass the quality control,</p>**<p>global DNA methylation values are not calculated because samples did not pass the quality control.</p

Box plot representation of global DNA methylation in control TK6 cells and TK6 cells exposed with benzene, hydroquinone, styrene, carbon tetrachloride and trichloroethylene without S9 metabolic mix.

<p>Global DNA methylation is expressed as percentage of 5-methylcytosine versus the total number of cytosines present in the genome. The box plot describes the median (line across the box), inter-quartile range and maximum and minimum values (whiskers). Outliers are shown as open circles outside the ends of whiskers.</p

Global DNA methylation in TK6 cells per chemical dose in the presence of S9 metabolic mix.

<p>Global DNA methylation is expressed as a percentage of 5-methylcytosine versus the total number of cytosines present in the genome.</p><p>SD: Standard deviation,</p>*<p>standard deviation could not be calculated because sample replicates did not pass the quality control,</p>**<p>global DNA methylation values are not calculated because samples did not pass the quality control.</p

Box plot representation of global DNA methylation in control TK6 cells and TK6 cells exposed with benzene, hydroquinone, styrene, carbon tetrachloride and trichloroethylene with S9 metabolic mix.

<p>Global DNA methylation is expressed as percentage of 5-methylcytosine versus the total number of cytosines present in the genome. The box plot describes the median (line across the box), inter-quartile range and maximum and minimum values (whiskers). Outliers are shown as open circles outside the ends of whiskers.</p

Changes in DNA Methylation in Mouse Lungs after a Single Intra-Tracheal Administration of Nanomaterials

<div><p>Aims</p><p>This study aimed to investigate the effects of nanomaterial (NM) exposure on DNA methylation.</p><p>Methods and Results</p><p>Intra-tracheal administration of NM: gold nanoparticles (AuNPs) of 5-, 60- and 250-nm diameter; single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) at high dose of 2.5 mg/kg and low dose of 0.25 mg/kg for 48 h to BALB/c mice. Study showed deregulations in immune pathways in NM-induced toxicity <i>in vivo</i>. NM administration had the following DNA methylation effects: AuNP 60 nm induced CpG hypermethylation in <i>Atm</i>, <i>Cdk</i> and <i>Gsr</i> genes and hypomethylation in <i>Gpx</i>; <i>Gsr</i> and <i>Trp53</i> showed changes in methylation between low- and high-dose AuNP, 60 and 250 nm respectively, and AuNP had size effects on methylation for <i>Trp53</i>.</p><p>Conclusion</p><p>Epigenetics may be implicated in NM-induced disease pathways.</p></div

Bronchoalveolar lavage (BAL) fluid analysis in mice exposed to nanomaterial.

<p>a): total cell count; b): differential cell count.; c): uptake/association by/with BAL macrophages. For clarity of presentation in panel b, significant groups are not annotated. In panel b, macrophages count was significant in following exposure groups: AuNPs 5nm 50μg and AuNPs 60nm 50μg compared to the vehicle; AuNP 5nm 50μg compared to AuNP 250nm 5μg; and AuNPs 60 nm 50μg compared to the AuNP 250nm 5μg dose categories. Neutrophils count was significant in following exposure groups: SWCNT 50μg and MWCNTs 50μg compared to vehicle. Lymphocytes count was significant in following exposure groups: SWCNT 50μg and MWCNTs 50μg compared to vehicle. In panel c, 100 macrophages were randomly counted for the microscopic presence or absence of NM aggregated inside the cytoplasm at 1000X magnification. Representative images of macrophage d): vehicle; e): AuNPs 5nm; f): AuNPs 60nm; g): AuNPs 250 nm; h): SWCNTs; i): MWCNTs. In panel a and c; the box plot describes the median (line across the box), inter-quartile range and maximum and minimum values (whiskers). Outliers are shown as colored circles outside the ends of whiskers. Data in panel b is represented as median ±SD. Asterisk sign (*) shows significance levels at <i>p</i> = 0.05 (dunn’s statistics). Gold nanoparticles: AuNPs; single-walled- and multi-walled carbon nanotubes: SWCNTs and MWCNTs.</p

Effect of nanomaterial (NM) exposure variables on methylation of promoters of genes.

<p>Effect of nanomaterial (NM) exposure variables on methylation of promoters of genes.</p

Effect of nanomaterial (NM) exposure on gene promoter methylation.

<p>Bars connect exposure groups with significant methylation difference, a-d): effects of gold nanoparticles (AuNPs) exposure on promoter methylation levels of <i>Atm</i> (a), <i>Cdk</i> (b), <i>Gp x</i>(c), and <i>Gsr</i> (d) genes in lungs. Effect of single and multi-walled carbon nanotubes (SWCNTs, MWCNTs) exposure on gene promoter methylation levels of <i>Atm</i> (e) gene in lungs. In panels, box plot describes the median (line across the box), inter-quartile range and maximum and minimum values (whiskers). Outliers are shown as colored circles outside the ends of whiskers. Asterisk sign (*) shows significance levels at <i>p</i> = 0.5 (dunn’s statistics). <i>Atm</i>: ataxia telangiectasia mutated; <i>Cdk</i>; cyclin-dependent kinase; <i>Gsr</i>: glutathione reductase; <i>Gpx</i>: glutathione peroxidase.</p

Effect of nanoparticles (NPs) dose and size on gene promoter methylation upon exposure.

<p>Bars connect exposure groups with significant methylation difference, a-d): effects of gold NPs (AuNPs) exposure dose on promoter methylation levels of <i>Gsr</i> (a, and b), <i>Trp53</i> (c) in lungs, and <i>Pparg</i> (d) genes in blood. AuNPs size effect on CpG methylation of <i>Trp53</i> gene was observed between 60 nm and 250 nm AuNPs. In panels, box plot describes the median (line across the box), inter-quartile range and maximum and minimum values (whiskers). Outliers are shown as colored circles outside the ends of whiskers. Asterisk sign (*) shows significance levels at <i>p</i> = 0.5 (dunn’s statistics). <i>Gsr</i>: glutathione reductase; <i>Trp53</i>: tumor protein P53; <i>Pparg</i>: peroxisome proliferator-activated receptor gamma.</p