Project description:The robust transcriptional plasticity of liver mediated through xenobiotic receptors underlies its ability to respond rapidly and effectively to diverse chemical stressors. Thus, drug-induced gene expression changes in liver serve not only as biomarkers of liver injury, but also as mechanistic sentinels of adaptation in metabolism, detoxification and tissue protection from chemicals. Modern RNA sequencing methods offer an unmatched opportunity to quantitatively monitor these processes in parallel and to contextualize the spectrum of dose-dependent stress, adaptation, protection and injury responses induced in liver by drug treatments. Using this approach, we profiled the transcriptional changes in rat liver following daily oral administration of 95 different compounds, many of which are known to be associated with clinical risk for drug induced liver injury (DILI) by diverse mechanisms.
Project description:Gene expression biomarkers are now available for application in the identification of genotoxic hazards. The TGx-DDI transcriptomic biomarker can accurately distinguish DDI from non-DDI exposures based on changes in the expression of 64 biomarker genes. The bioamarker was originally derived from DNA microarray gene expression profiles of TK6 human lymphoblastoid cells post 4-hour exposure to 28 reference DDI and non-DDI agents [Li et al. 2015]. To broaden the applicability of TGx-DDI, the biomarker was tested using quantitative RT-PCR (qPCR), which is accessible to most molecular biology laboratories. To assess the classification capability of the biomarker using qPCR, a custom 96-well TaqMan qPCR array (TGx-DDI qPCR array) was constructed using the 64 biomarker genes. TK6 cells were exposed to each of the 28 reference agents and their vehicle controls for 4 hours and the expression level of the TGx-DDI genes were profiled using the TaqMan arrays. This study provides reference qPCR expression profiles of the TGx-DDI biomarker for DDI chemical classification using qPCR.
Project description:Cell-based application of a transcriptomic biomarker, TGx-DDI, in addressing potentially irrelevant positive findings in chromosome damage assays
Project description:The TGx-DDI is a transcriptomic biomarker used to predict the DNA damage-inducing (DDI) capability of chemicals by providing mechanistic information to aid in the interpretation of positive genotoxicity data. The biomarker was developed within the Health and Environmental Sciences Institute (HESI) and measures transcriptional changes in a set of primarily p53-responsive genes. We investigated three antibiotic drugs, nitrofurantoin (NIT), novobiocin sodium salt (NOV) and metronidazole (MTZ), with a long history of clinical use in human and/or veterinary applications. While all three drugs are considered safe, there is some evidence of chromosome damage with NIT and NOV. We conducted high-throughput CometChip and TGx-DDI assays to evaluate the drugs in a parallel test strategy to explore their toxicity using these newer mechanism-based tests. An extended concentration-response analysis was conducted in human TK6 cells (from 0 to 1 mM). The alkaline CometChip assay was used to measure DNA damage, while TGx-DDI was applied using TempO-Seq and NanoString technologies (in two different laboratories) to confirm reproducibility of the results. The CometChip was negative for all three drugs except at overtly cytotoxic concentrations, which were eliminated from the gene expression analysis. NIT and MTZ were classified as non-DDI by TGx-DDI at all concentrations tested. NOV classified as DDI at the highest concentrations tested. NOV is bacterial DNA-gyrase inhibitor that also acts as a topoisomerase II inhibitor at high concentrations. The TGx-DDI classification results were identical across laboratories/technologies. This case study demonstrates the utility of TGx-DDI to de-risk NIT and NOV, and the reproducibility of the biomarker.
Project description:The TGx-DDI is a transcriptomic biomarker used to predict the DNA damage-inducing (DDI) capability of chemicals by providing mechanistic information to aid in the interpretation of positive genotoxicity data. The biomarker was developed within the Health and Environmental Sciences Institute (HESI) and measures transcriptional changes in a set of primarily p53-responsive genes. We investigated three antibiotic drugs, nitrofurantoin (NIT), novobiocin sodium salt (NOV) and metronidazole (MTZ), with a long history of clinical use in human and/or veterinary applications. While all three drugs are considered safe, there is some evidence of chromosome damage with NIT and NOV. We conducted high-throughput CometChip and TGx-DDI assays to evaluate the drugs in a parallel test strategy to explore their toxicity using these newer mechanism-based tests. An extended concentration-response analysis was conducted in human TK6 cells (from 0 to 1 mM). The alkaline CometChip assay was used to measure DNA damage, while TGx-DDI was applied using TempO-Seq and NanoString technologies (in two different laboratories) to confirm reproducibility of the results. The CometChip was negative for all three drugs except at overtly cytotoxic concentrations, which were eliminated from the gene expression analysis. NIT and MTZ were classified as non-DDI by TGx-DDI at all concentrations tested. NOV classified as DDI at the highest concentrations tested. NOV is bacterial DNA-gyrase inhibitor that also acts as a topoisomerase II inhibitor at high concentrations. The TGx-DDI classification results were identical across laboratories/technologies. This case study demonstrates the utility of TGx-DDI to de-risk NIT and NOV, and the reproducibility of the biomarker.
Project description:In present study, it was found that the co-culture of Wickerhamomyces anomalus Y-5 and L. plantarum RX-8 could enhance bacteriocin production. To analyze the interaction between W. anomalus Y-5 and L. plantarum RX-8, a quantitative proteomic approach was used to analyze and compare the proteome in L. plantarum RX-8 and W. anomalus Y-5 under mono-culture and co-culture. In total, 339 differently expressed proteins (DEPs) were screened in comparison of L. plantarum RX-8 under mono-culture and co-culture, 645 proteins of W. anomalus Y-5 changed in mono-culture and co-culture. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that DEPs participated in various metabolic pathways such as PTS system, glycolysis, galactose metabolism, glutamate, aspartate, arginine and cysteine metabolism etc. These pathways were related to inducing mechanism on improving bacteriocin production by co-culture. Quantitative proteomic analysis-based strategies can therefore provide further evidence for new regulated targets to improve the production of bacteriocins.
Project description:This SuperSeries is composed of the following subset Series: GSE13423: Microarray Analysis of Toxicogenomic Effects of Sodium Hypochlorite on Mycobacterium bovis BCG GSE14272: Microarray Analysis of Toxicogenomic Effects of Hydrogen Peroxide on Mycobacterium bovis BCG Refer to individual Series
Project description:SOX2 is the main gene involved in anophthalmia. In order to identify genes regulated by SOX2 transcription factors (genes that could be good candidates to also be involved in ocular development), we studied transcriptomic profiles of murine genetically modified stem cells overexpressing the RAX gene (CCE-Rx cells) after transfection by a siRNA against SOX2 or a scramble siRNA. murine genetically modified stem cells overexpressing the RAX gene (CCE-Rx cells) after transfection by a siRNA against SOX2 or a scramble siRNA
Project description:The present study explores the potential of compound-specific gene-upregulation profiles in the ubiquitous purple nonsulfur bacterium Rhodospirillum rubrum S1H as biomarkers for exposure to surface water contaminants, i.e. high production-volume pharmaceuticals. Even though the pharmaceuticals [i.e., acetylsalicylic acid (ASA), diclofenac (DCF), and 17M-NM-1-ethinylestradiol (EE2)] did not affect the bacterial growth kinetics at environmentally-relevant concentrations (86nM), whole-genome microarray analyses revealed the upregulation of 128, 49, and 47 genes upon exposure to DCF, ASA, and EE2, respectively. A strong overlap (27-48%) was observed between transcriptional responses, but a total of 93 genes were found to be upregulated in a compound-specific manner. Hence, we were able to identify 74 and 15 potential biomarker genes for DCF and ASA, respectively. DCF specifically induced genes involved mainly in stress response, signal transduction, response regulation, the electron transport chain, and transcription, while ASA specifically induced genes predominantly involved in signal transduction, response regulation, and trans-membrane translocation. Moreover, our findings validated triclosan-specific biomarker genes that were identified previously. As only 4 genes were specifically-upregulated for EE2, no representative biomarker profile was identified. This study illustrates that a pollutant-specific molecular response can be generated in R. rubrum S1H, which could become a relevant model-microorganism to screen for the ecological impact of surface water contaminants in situ. KEYWORDS: environmental impact studies, risk assessment, biosensor, wastewater, micropollutant, aspirin Two-condition experiments. Comparing samples after induction of three pharmaceuticals each with a non-induced samples. Biological triplicate. Each array contains 3 technical replicates.
Project description:We tested if psychoactive pharmaceuticals (fluoxetine, carbamazapine, venlafaxine) at lower concentrations (in ppb) could induce gene expressions linked with neurological disoders.