Gene expression profiles from livers of ethinylestradiol- and chlorpromazine-treated C57BL6/mice after 25 days
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ABSTRACT: Toxicogenomics is used as a tool to identify mechanisms and markers of cholestasis in C57BL/6 mice treated by oral gavage using ethinylestradiol(EE2) and chlorpromazine (CPZ). A 25 day dose range finding study was performed, which resulted in no changes in clinical chemistry (serum cholesterol, total bile acids, and total bilirubin) or histopathology (hepatocyte vacuolization). Whole genome expression profiling of the liver was assessed after 25 days of repeated exposure with 10 mg/kg bw for CPZ and 3.70 mg/kg bw for EE2.
Project description:Mechanism-based toxicogenomics (tgx) is used as a tool to identify markers reflective of the onset and progression of cholestasis in C57BL/6 mice using Cyclosporin A (CsA) as a model compound. Critical doses for tgx analysis were derived from a dose range finding study in which increase of serum cholesterol, total bile acids, and total bilirubin as well as induction of hepatocyte vacuolization 25 days upon repeated CsA administration through oral gavage were considered as critical effects. For tgx analysis to find early markers, livers of mice repeatedly treated with 3 mg/kg BW, 8.9 mg/kg BW, and 26.7 mg/kg BW for one, four, and eleven days were collected.
Project description:we assessed characteristic molecular and proteomic signatures in rat liver treated with drugs (pyrazinamide, ranitidine, enalapril, carbamazepine, and chlorpromazine) that are known to cause DILI in humans. In the present study, we assessed the characteristic gene expression signature for DILI in a rat model. Rats were administered representative drugs that are already known to induce DILI in humans and transcriptomic changes in rat liver were analyzed. The representative drugs, which induce three types (hepatocellular, mixed, and cholestatic) of DILI, that were used in this study were pyrazinamide (PZA, 150~1500 mg/kg), ranitidine (RAN, 209.5~2095 mg/kg), enalapril (ENA, 148.65~1486.5 mg/kg), carbamazepine (CBZ, 97.85~978.5 mg/kg), and chlorpromazine (CPZ, 7.1~71 mg/kg).
Project description:The objective of this study was to investigate pathway signatures altered in the livers of female largemouth bass (LMB) and their potential links with biological responses by dietary exposure to 0.2 mg EE2/Kg (1% of their body weight) over two months using a transcriptomics approach. A high concentration of dietary 17alpha-ethinylestradiol (EE2) can activate key signaling pathways in response to oxidative damage may occur regardless of tumorigenesis and cancer. Female LMB received about 1.2g EE2/day/fish (from EE2-laced feed containing 0.2 mg EE2/Kg) for 60 days.
Project description:To examine whether the BPA-induced morphological alterations of the fetal mouse mammary glands are a) associated with changes in mRNA expression reflecting estrogenic actions and/or b) dependent on the estrogen receptor α (ERα), we compared the transcriptomal effects of BPA and the steroidal estrogen ethinylestradiol (EE2) on fetal mammary tissues of wild type and ERα knock-out mice. Mammary glands from fetuses of dams exposed to vehicle, 250 ng BPA/kg BW/d or 10 ng EE2/kg BW/d from embryonic day (E) 8 were harvested at E19. Total RNA was subjected to transcriptomal profiling using Affymetrix mouse genome 430 2.0 microarray.
Project description:Mechanism-based toxicogenomics (tgx) is used as a tool to identify markers reflective of the onset and progression of cholestasis in C57BL/6 mice using Cyclosporin A (CsA) as a model compound. Critical doses for tgx analysis were derived from a dose range finding study in which increase of serum cholesterol, total bile acids, and total bilirubin as well as induction of hepatocyte vacuolization 25 days upon repeated CsA administration through oral gavage were considered as critical effects. For tgx analysis to find early markers, livers of mice repeatedly treated with 3 mg/kg BW, 8.9 mg/kg BW, and 26.7 mg/kg BW for one, four, and eleven days were collected. 60 samples are analyzed; per treatment duration (1, 4, 11 days), time-matched vehicle (olive oil) controls and three dose groups (3, 8.9, 26.7 mg/kg BW) were included; each group consisted of 5 replicates; 3 arrays were excluded, 2 because of quality control restrictions, 1 because of outlier properties. 2 that failed QC are omitted. Final data consists of 58 CEL files.
Project description:Toxicogenomics (tgx) is used as a tool to identify mechanisms and markers of necrosis in C57BL/6 mice treated by oral gavage using acetaminophen (APAP), isoniazid (INZ), and paraquat (PQ). Critical doses for tgx analysis were derived from a 25 day dose range finding study. For tgx analysis, livers of mice were collected 1 and 2 days after a single compound dose of 168.75, 225, and 300 mg/kg bw for APAP; 12.5, 25, and 50 mg/kg bw for PQ; and 22, 44, and 88 mg/kg bw for INZ. All samples were diluted in water.
Project description:Chemical risk assessment for avian species typically depends on information from toxicity tests performed in adult birds. Early-life stage (ELS) toxicity tests have been proposed as an attractive alternative, but incorporation of these data into existing frameworks will require knowledge about the similarities/differences between ELS and adult responses. The present study uses transcriptomics to assess hepatic gene expression in ELS and adult Japanese quail following exposure to ethinylestradiol (EE2). ELS quail were dosed with 0, 3.33, and 33.3 µg EE2/g egg via air cell injection prior to incubation. Adult quail were fed a single dose of EE2 at 0, 0.5, and 5 mg/kg body weight by gavage. Liver tissue was collected from 5-6 individuals per dose group at mid-incubation for ELS quail, and 4 days after dosing for adult birds. A total of 283 and 111 differentially expressed genes (DEGs) were detected in ELS and adult quail, respectively, 16 of which were shared across life stages. Shared DEGs included estrogenic biomarkers such as vitellogenin genes and Apovitellenin-1. For the dose groups that resulted in the highest number of DEGs (ELS [3.3 µg/g]; adult [5 mg/kg]), 21 and 35 KEGG pathways were enriched, respectively. Ten of these pathways were shared between life stages, including pathways involved with signaling molecules and interaction, and endocrine system. Taken together, our results suggest conserved mechanisms of action following estrogenic exposure across two life stages, with evidence from differentially expressed genes and enriched pathways. This study contributes to the development and evaluation of toxicogenomic and ELS approaches as alternative toxicity testing methods and supports the use of the ELS test for screening estrogenic chemicals.
Project description:Chemical risk assessment for avian species typically depends on information from toxicity tests performed in adult birds. Early-life stage (ELS) toxicity tests have been proposed as an attractive alternative, but incorporation of these data into existing frameworks will require knowledge about the similarities/differences between ELS and adult responses. The present study uses transcriptomics to assess hepatic gene expression in ELS and adult Japanese quail following exposure to ethinylestradiol (EE2). ELS quail were dosed with 0, 3.33, and 33.3 µg EE2/g egg via air cell injection prior to incubation. Adult quail were fed a single dose of EE2 at 0, 0.5, and 5 mg/kg body weight by gavage. Liver tissue was collected from 5-6 individuals per dose group at mid-incubation for ELS quail, and 4 days after dosing for adult birds. A total of 283 and 111 differentially expressed genes (DEGs) were detected in ELS and adult quail, respectively, 16 of which were shared across life stages. Shared DEGs included estrogenic biomarkers such as vitellogenin genes and Apovitellenin-1. For the dose groups that resulted in the highest number of DEGs (ELS [3.3 µg/g]; adult [5 mg/kg]), 21 and 35 KEGG pathways were enriched, respectively. Ten of these pathways were shared between life stages, including pathways involved with signaling molecules and interaction, and endocrine system. Taken together, our results suggest conserved mechanisms of action following estrogenic exposure across two life stages, with evidence from differentially expressed genes and enriched pathways. This study contributes to the development and evaluation of toxicogenomic and ELS approaches as alternative toxicity testing methods and supports the use of the ELS test for screening estrogenic chemicals.
Project description:17alpha-ethinylestradiol (EE2) is one of the most potent estrogens that have the ability to interfere with the endocrine system of fish. The objective was to investigate the effects and mechanisms of action caused by 60 days of dietary exposure to 0.2 mg EE2/kg and 0.07 mg EE2/kg feed in female largemouth bass (LMB) during the reproductive season. Microarrays and pathway analyses were performed on hepatic tissues to identify genes and biological processes altered in female LMB by EE2 exposure. The hypothesis was that the two concentrations of EE2 would produce dose-response changes in sensitive genes. Body and ovary weights were measured and blood was collected for measurement of plasma steroid hormones (17beta-estradiol (E2), testosterone (T)) and vitellogenin (VTG) using ELISA. The 0.2 mg EE2/kg feed exposure reduced the gonadosomatic index (GSI) by 75%, and plasma levels of E2 and T were reduced by over 90%. Plasma VTG was increased by approximately 100% (from 4 to 8mg/ml) by the 0.2 mg/kg treatment. T levels, from the 0.07 mg EE2/kg feed, reduced GSI by approximately 30% and circulating E2 and T by ~80% but did not affect VTG concentrations. We found 1,594 and 1,165 genes were significantly affected (p<0.05) by the 0.07 mg EE2/kg feed and 0.2 mg EE2/kg feed, respectively. Gene ontology (GO) analysis revealed that there were different biological processes regulated by the two concentrations of EE2. Pathway analysis showed that the 0.07 mg EE2/kg feed exposure caused differential regulation of genes associated with fatty acid biosynthesis and glycolysis, indicating some metabolic effects. In contrast, the 0.2 mg EE2/kg feed exposure altered transcription of genes involved in immune response and apoptosis, suggesting a toxic response at this concentration. These results suggest that the two concentrations demonstrated distinct physiological responses, with the higher concentration inducing complete endocrine disruption in LMB. These findings demonstrate the usefulness of microarrays to identify possible biomarkers and modes of toxic action to dietary exposure in LMB. Two concentrations of EE2 would produce dose-response changes in sensitive genes. Female LMB were fed 5 days per week for 60 days with floating pellets that contained 0.07 or 0.2 mg/kg of EE2.
Project description:Toxicogenomics (tgx) is used as a tool to identify mechanisms and markers of steatosis in C57BL/6 mice treated by oral gavage using amiodarone (AMD), valproic acid (VPA), and tetracycline (TET). Critical doses for tgx analysis were derived from a 25 day dose range finding study. For tgx analysis, livers of mice were collected after 1, 4, and 11 days of repeated treatment with 6.7, 20, and 60 mg/kg bw for AMD; 125, 250, and 500 mg/kg bw for VPA; and 14.8, 44, and 133 mg/kg bw for TET.