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GSE11091
Rattus norvegicus
24 Downloadable Samples
Affymetrix Rat Expression 230A Array (rae230a)
Description
Zinc is a common metal in most ambient particulate matter (PM), and has been proposed to be a causative component in PM-induced adverse cardiovascular health effects. Zinc is also an essential metal and has the potential to induce many physiological and nonphysiological changes. Most toxicological studies employ high levels of zinc. We hypothesized that subchronic inhalation of environmentally relevant levels of zinc would cause cardiac changes in healthy rats. To address this question, healthy male WKY rats (12 wks age) were exposed via nose only inhalation to filtered air or 10, 30 or 100 ug/m3 of aerosolized Zn in sulfate form, 5 h/d, 3 d/wk for 16 wks. Necropsies occurred 48 h after the last exposure to ensure effects were due to chronic exposure rather than the last exposure. No significant changes were observed in neutrophil or macrophage count, total lavageable cells, or enzyme activity levels (lactate dehydrogenase, n-acetyl ?-D-glucosaminidase, ?-glutamyl transferase) in bronchoalveolar lavage fluid, indicating minimal pulmonary effect. In the heart, cytosolic glutathione peroxidase activity decreased, while mitochondrial ferritin levels increased and succinate dehydrogenase activity decreased, suggesting a mitochondria-specific effect. Although no cardiac pathology was seen, cardiac gene array analysis indicated changes in genes involved in cell signaling, a pattern concordant with known zinc effects. These data indicate that inhalation of zinc at environmentally relevant levels may induce cardiac effects. While changes are small in healthy rats, these may be especially relevant in individuals with pre-existent cardiovascular disease.
Publication Title
Subchronic inhalation of zinc sulfate induces cardiac changes in healthy rats.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
The nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS) through activation by HS factor-1 (HSF1). We hypothesized that there are interactions on a genetic level between PPAR and the HS response mediated by HSF1. Wild-type and PPAR-null mice were exposed to HS, the PPAR agonist WY-14,643 (WY), or both; gene and protein expression was examined in the livers of the mice 4 or 24 hrs after HS. Gene expression profiling identified a number of Hsp family members that were altered similarly in both mouse strains. However, most of the targets of HS did not overlap between strains. A subset of genes was shown by microarray and RT-PCR to be regulated by HS in a PPAR-dependent manner. HS also down-regulated a large set of mitochondrial genes specifically in PPAR-null mice that are known targets of PPARg co-activator 1 (PGC-1) family members. Pretreatment of PPAR-null mice with WY increased expression of PGC-1b and target genes and prevented the down-regulation of the mitochondrial genes by HS. A comparison of HS genes regulated in our dataset with those identified in wild-type and HSF1-null mouse embryonic fibroblasts indicated that although many HS genes are regulated independently of both PPAR and HSF1, a number require both factors for HS responsiveness. These findings demonstrate that the PPAR genotype has a dramatic effect on the transcriptional targets of HS and support an expanded role for PPAR in the regulation of proteome maintenance genes after exposure to diverse forms of environmental stress including HS.
Publication Title
Analysis of the heat shock response in mouse liver reveals transcriptional dependence on the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha).
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 36 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 96 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Male and female CD-1 mice were administered dietary Phenobarbital for 2 or 7 days. In-life, enzyme activity, cell proliferation, genomic analysis, and Bench-mark dose modeling was carried out.
Publication Title
Dose-response modeling of early molecular and cellular key events in the CAR-mediated hepatocarcinogenesis pathway.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 96 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
High-throughput transcriptomic (HTTr) technologies are increasingly being used to screen environmental chemicals in vitro to identify molecular targets and provide mechanistic context for regulatory testing. The androgen receptor (AR, NR3C4) regulates male sexual development, is involved in the pathogenesis of a number of cancers, and is often the target of endocrine disruptors. Here, we describe the development and validation of a novel gene expression biomarker to identify AR-modulating chemicals using a pattern matching method. AR biomarker genes were identified by their consistent expression after exposure to 4 AR agonists and opposite expression after exposure to 4 AR antagonists. A genetic filter was used to include only those genes that were regulated by AR. Most of the resulting 51 biomarker genes were shown to be directly regulated by AR as determined by ChIP-Seq analysis of AR-DNA interactions. The biomarker was evaluated as a predictive tool using the fold-change rank-based Running Fisher algorithm which compares the expression of AR biomarker genes under various treatment conditions. Using 163 comparisons from cells treated with 98 chemicals, the biomarker gave balanced accuracies for prediction of AR activation or AR suppression of 97% or 98%, respectively. The biomarker was able to correctly classify 16 out of 17 AR reference antagonists including those that are weak and very weak. Predictions based on comparisons from AR-positive LAPC-4 cells treated with 28 chemicals in antagonist mode were compared to those from an AR pathway model based on 11 in vitro high-throughput screening assays that queried different steps in AR signaling. The balanced accuracy was 93% for suppression. Using our approach, we identified conditions in which AR was modulated in a large collection of microarray profiles from prostate cancer cell lines including 1) AR constitutively active mutants or knockdown of AR, 2) depletion of androgens by castration or removal from media, and 3) modulators that work through indirect mechanisms including suppression of AR expression. These results demonstrate that the AR gene expression biomarker could be a useful tool in HTTr to identify AR modulators in large collections of microarray data derived from AR-positive prostate cancer cell lines.
Publication Title
Identification of Androgen Receptor Modulators in a Prostate Cancer Cell Line Microarray Compendium.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 59 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Exposure to PFOA during gestation altered the expression of genes related to fatty acid catabolism in both the fetal liver and lung. In the fetal liver, the effects of PFOA were robust and also included genes associated with lipid transport, ketogenesis, glucose metabolism, lipoprotein metabolism, cholesterol biosynthesis, steroid metabolism, bile acid biosynthesis, phospholipid metabolism, retinol metabolism, proteosome activation, and inflammation. These changes are consistent with activation of PPAR alpha. Non-PPAR alpha related changes were suggested as well.
Publication Title
Gene expression profiling in the lung and liver of PFOA-exposed mouse fetuses.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 47 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
PPAR-null and wild-type male mice treated with PFHxS or PFNA
Publication Title
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sample Metadata Fields
Sex, Specimen part, Compound
View Samples- Rattus norvegicus
- 45 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
The modes of triazole reproductive toxicity have been characterized by an observed increased in serum testosterone and reduced insemination and fertility indices. The key events involved in the disruption in testosterone homeostasis and reduced fertility remain unclear. Gene expression analysis was conducted on liver from Sprague Dawley rats dosed with myclobutanil (300 mg/kg/day) or triadimefon (175 mg/kg/day) for 6, 24 or 336 hours. Pathway-based analysis highlighted key biological processes affected by all three triazoles in the liver including fatty acid catabolism, steroid metabolism, and xenobiotic metabolism. Within the pathways identified in the liver, specific genes involved in phase I-III metabolism and fatty acid metabolism were affected by all three triazoles. These modulated genes are part of a network of lipid and testosterone homeostasis pathways regulated by the constitutive androstane (CAR) and pregnane X (PXR) receptors. Gene expression profiles from this study indicate triazoles activate CAR and PXR; increase fatty acid catabolism and steroid metabolism in the liver; constituting a plausible series of key events contributing to the observed disruption in testosterone homeostasis.
Publication Title
Toxicogenomic effects common to triazole antifungals and conserved between rats and humans.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 40 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The triazole antifungals myclobutanil (MYC), propiconazole (PPZ) and triadimefon (TDF) [Propiconazole CASNR 60207-90-1; Triadimefon CASNR 43121-43-3; Myclobutanil CASNR 88671-89-0] all disrupt steroid hormone homeostasis and cause varying degrees of hepatic toxicity. To identify biological pathways consistently activated across various study designs, gene expression profiling was conducted on livers from rats following acute, repeated dose, or prenatal to adult exposures. To explore conservation of responses across species, gene expression from these rat in vivo studies were also compared to in vitro data from rat and human primary hepatocytes exposed to MYC, PPZ, or TDF. Pathway and gene level analyses across time of exposure, dose, and species identified patterns of expression common to all three triazoles, which were also conserved between rodents and humans. Pathways affected included androgen and estrogen metabolism, xenobiotic metabolism signaling through CAR and PXR, and CYP mediated metabolism. Many of the differentially expressed genes are regulated by the nuclear receptors CAR, PPAR alpha and PXR, including ABC transporter genes (Abcb1 and MDR1), genes significant to xenobiotic, fatty acid, sterol and steroid metabolism (Cyp2b2 and CYP2B6; Cyp3a1 and CYP3A4; Cyp4a22 and CYP4A11) and xxx (Ugt1a1 and UGT1A1). Modulation of hepatic sterol and steroid metabolism is a plausible mechanism for triazole induced increases in serum testosterone. The gene expression changes caused by all three triazoles appear to focus on pathways regulating lipid and testosterone homeostasis, identifying potential common mechanisms of triazole hepatotoxicity that are conserved between rodents and humans.
Publication Title
Toxicogenomic effects common to triazole antifungals and conserved between rats and humans.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 35 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
The modes of triazole reproductive toxicity have been characterized by an observed increased in serum testosterone and reduced insemination and fertility indices. The key events involved in the disruption in testosterone homeostasis and reduced fertility remain unclear. Gene expression analysis was conducted on liver and testis from Wistar Han IGS rats fed myclobutanil (M: 500, 2000 ppm), propiconazole (P: 500, 2500 ppm), or triadimefon (T: 500, 1800 ppm) from gestation day six to postnatal day 92. Pathway-based analysis highlighted key biological processes affected by all three triazoles in the liver including fatty acid catabolism, steroid metabolism, and xenobiotic metabolism. Triadimefon induced a distinctive expression profile of genes involved in liver sterol biosynthesis. There were no common pathways modulated by all three triazoles in the testis. Within the pathways identified in the liver, specific genes involved in phase I-III metabolism (Aldh1a1, Cyp1a1, Cyp2b2, Cyp3a1, Slco1a4, Udpgtr2), fatty acid metabolism (Cyp4a10, Pc, Ppap2b), and steroid metabolism (Srd5a1, Ugt1a1, Ugt2a1) were affected by all three triazoles. These modulated genes are part of a network of lipid and testosterone homeostasis pathways regulated by the constitutive androstane (CAR) and pregnane X (PXR) receptors. Gene expression profiles from this study indicate triazoles activate CAR and PXR; increase fatty acid catabolism, sterol biosynthesis, and steroid metabolism in the liver; constituting a plausible series of key events contributing to the observed disruption in testosterone homeostasis.
Publication Title
Mode of action for reproductive and hepatic toxicity inferred from a genomic study of triazole antifungals.
Sample Metadata Fields
No sample metadata fields
View Samples