This study focus a comparative toxicogenomic analysis of the effects of four herbicides (alachlor, ALA, S-metolachlor, S-MET, diuron, DIU, and MCPA-methyl ester, MCPA-ME), one insecticide (carbofuran, CAB), and one fungicide (pyrimethanil, PYR), in the model yeast Saccharomyces cerevisiae, to predict potential cytotoxic effects of these xenobiotics while providing mechanistic clues possibly relevant for experimentally less accessible non-target eukaryotes. The six model pesticides selected have been used worldwide in agricultural activities, at the present time or in the past, and have different modes of action on their target-organisms. Moreover, some of them are currently in Annex 1 of EC Directive 1107/2009 (repealing 91/414), that is they are in use in the EU, but having some ecotoxicological concerns (e.g. S-MET, PYR, MCPA-ME), others have their use restricted and/or are priority substances under the Water Framework Directive (e.g. ALA, DIU), and one was banned (e.g. CAB).
Comparative analysis of transcriptomic responses to sub-lethal levels of six environmentally relevant pesticides in Saccharomyces cerevisiae.
Treatment
View SamplesThe world-wide used herbicide alachlor is among the priority substances listed in the European Water Framework Directive. We aimed at finding molecular biomarkers in the model yeast Saccharomyces cerevisiae that may be used to predict potential cytotoxic effects of this xenobiotic while providing mechanistic clues possibly relevant for experimentally less accessible non-target eukaryotes.
Transcriptional profiling in Saccharomyces cerevisiae relevant for predicting alachlor mechanisms of toxicity.
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View SamplesDuring early development, the correct establishment of the body axes is a critical step. The anterior pole of the mouse embryo is established when Distal Visceral Endoderm (DVE) cells migrate to form the Anterior Visceral Endoderm (AVE). Asymmetrical expression of Lefty1, Cerl and Dkk determines the direction of DVE migration and the future anterior side. Besides being implicated in the establishment of Anterior-Posterior axis the AVE has also been correlated with anterior neural specification. In order to better understand the role of the AVE in these processes, this cell population was isolated using a cerlP-EGFP transgenic mouse line, and a differential screening was performed using Affymetrix GeneChip technology. From this differential screening, 175 genes were found to be upregulated in the AVE, whereas 35 genes were upregulated in the Proximal-posterior sample. Using DAVID, here we characterize the AVE cell population regarding cellular component, molecular function and biological processes. Among the genes that were found to be upregulated in the AVE, several novel genes with expression in the AVE were identified. Four of the identified transcripts displaying high-fold change were further characterized by in situ hybridization in early stages of development in order to validate the screening. From those four selected genes, ADTK1 was chosen to be functionally characterized by targeted inactivation in ES cells. ADTK1 encodes for an unknown serine/threonine kinase. ADTK null mutants present short limbs and defects in the eye and ear. Taken together, these data point to the importance of reporting novel genes present in the AVE.
Identification and functional analysis of novel genes expressed in the Anterior Visceral Endoderm.
Specimen part
View SamplesOur aim is to identify circadian transcripts that are co-regulated with [Ca2+]cyt, with the eventual goal of identifying genetic regulators and targets for circadian oscillations of [Ca2+]cyt. We have identified two conditions in which [Ca2+]cyt behaves differently to other circadian outputs. 1. Treatment of plants with nicotinamide, a metabolic inhibitor of ADPR cyclase, abolishes the circadian oscillations of [Ca 2+]cyt. However, leaf movement, CCA1, LHY, TOC1 and CAB transcript abundance and CAB promoter activity are all rhythmic albeit with a longer period (Dodd et al., 2007). 2. The toc1-1 mutant, which shortens the circadian period of all other rhythms tested, has no effect on the period of [Ca2+]cyt oscillations (Xu et al., 2007). We will measure the circadian regulation of transcript abundance in wild type (C24), toc1-1 and nicotinamide (C24)-treated plants.
Correct biological timing in Arabidopsis requires multiple light-signaling pathways.
Specimen part, Treatment, Time
View SamplesThe murine thymus produces discrete T cell subsets making either IFN- or IL-17, but the role of the TCR in this developmental process remains controversial. Here we generated a non-transgenic and polyclonal model of reduced TCR expression and signal strength selectively on T cells. Mice haploinsufficient for both CD3 and CD3 (CD3DH) showed normal thymocyte subsets but specific defects in T cell development, namely impaired differentiation of IL-17-producing embryonic V6+ (but not adult V4+) T cells and a marked depletion of IFN--producing CD122+ NK1.1+ (V1-biased) T cells throughout life. As result, adult CD3DH mice showed defective peripheral IFN- responses and were resistant to experimental cerebral malaria. Thus, strong TCR signaling is required within specific developmental windows with distinct V usage and differential cytokine production by effector T cell subsets.
TCR signal strength controls thymic differentiation of discrete proinflammatory γδ T cell subsets.
Specimen part
View SamplesHuman infection with Cryptococcus neoformans (Cn), a prevalent fungal pathogen, occurs by inhalation and deposition in the lung alveoli of infectious particles. The subsequent host pathogen interaction is multifactorial and can result either in eradication, latency or extra-pulmonary dissemination. Successful control of Cn infection is dependent on host macrophages as shown by numerous studies. However in vitro macrophages display little ability to kill Cn. Recently, we reported that ingestion of Cn by macrophages induces early cell cycle progression that is subsequently followed by mitotic arrest, an event that almost certainly reflects damage to the host cell. The goal of the present work was to understand macrophage pathways affected by Cn toxicity. Infection of J774.16 macrophage-like cell line macrophages by Cn in vitro was associated with changes in gene pattern expression. Concomitantly we observed depolarization of macrophage mitochondria and alterations in protein translation rate. Our results indicate that Cn infection impairs multiple host cellular functions. Therefore we conclude Cn intracellular residence in macrophages undermines the health of these critical phagocytic cells interfering with their ability to clear the fungal pathogen.
Macrophage mitochondrial and stress response to ingestion of Cryptococcus neoformans.
Specimen part, Cell line, Time
View SamplesUnderstanding the mechanisms by which cells respond to chemotherapeutics is key to identifying means to improve therapy effiicacy while reducing systemic toxicity of these widely used classes of drugs. While determining the role of NRF2-GSH and ER stress in cells exposed to alkylating compounds such as methyl-methanesulfonate (MMS), we asked if these pathways could also be a general cell damage response relevant to other clinically used chemotherapeutics or if it is an alkylation specific response. With this intent, we performed RNA sequencing of MDA-MB231 breast cancer and U2OS osteosarcoma cells lines treated for 8 hours with a topoisomerase II inhibitor etoposide (20 µM), the antimitotic beta-tubulin-interacting drug paclitaxel (0.2 µM), doxorubicin (1 µM) and compared to MMS (40 µg/mL) treated cells. Doses represent IC50 level after 72 hours exposure. We observed that even though non-alkylating drugs, especially etoposide, caused an increase in the mRNA expression of some NRF2 and ER stress signaling markers, the number and magnitude of upregulation of genes markers in either pathway was more pronounced in alkylation treatments compared to other drugs. This indicates that alterations in NRF2 and ER stress pathways could be more likely associated with differential sensitivity to alkylating chemotherapies. Overall design: MDA-MB231 breast cancer and U2OS osteosarcoma cells lines were treated with the 72 h IC50 dose of etoposide (20 µM), paclitaxel (0.2 µM), doxorubicin (1 µM) or MMS (40 µg/mL) for 8 h, and RNA was extracted and analyzed.
Alkylating Agent-Induced NRF2 Blocks Endoplasmic Reticulum Stress-Mediated Apoptosis via Control of Glutathione Pools and Protein Thiol Homeostasis.
Specimen part, Cell line, Treatment, Subject
View SamplesMice selected for high and low acute inflammation were tested for pristane induced arthritis, showing to be susceptible and resistant, respectively.
Pristane-induced arthritis loci interact with the Slc11a1 gene to determine susceptibility in mice selected for high inflammation.
Sex, Age, Specimen part
View SamplesMolecular targeted compounds are emerging as important component to improve the efficacy of classical chemotherapeutics. In this study, we tested whether using low dose sorafenib to reduce off target inhibitions of kinases impacts the antitumor effect of alkylating agents in breast cancer models. Overall design: MDA-MB231 cells were treated with 1 µM sorafenib, 40 µg/mL MMS, or pre-incubated with 1 µM sorafenib for 12 h followed by 40 µg/mL MMS, each in two independent experiments. RNA was harvested 8 and 24 h, or post MMS treatment for combination treatment.
Sorafenib improves alkylating therapy by blocking induced inflammation, invasion and angiogenesis in breast cancer cells.
Specimen part, Cell line, Subject
View SamplesThe thorough characterization of the transcriptome of endogenous podocytes has been hampered by low yields of cell isolation procedures. Here we introduce a double fluorescent reporter mouse model combined with an optimized bead perfusion protocol and efficient single cell dissociation yielding more than 500,000 podocytes per mouse allowing for global, unbiased downstream applications. Combining mRNA transcriptional profiling revealed programs of highly specific gene regulation tightly controlling cytoskeleton, cell differentiation, endosomal transport and peroxisome function in podocytes. Strikingly, the analyses further predict that these podocyte-specific gene regulatory networks are accompanied by alternative splicing of respective genes. In summary, the presented omics approach will facilitate the discovery and integration of novel gene, protein and organelle regulatory networks that deepen our systematic understanding of podocyte biology.
Molecular fingerprinting of the podocyte reveals novel gene and protein regulatory networks.
Specimen part
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