Arsenic metalloid is a double-edge sword. On the one hand it is a very toxic and powerful carcinogen, and on the other it has been successfully used in the treatment of acute promyelocytic leukemia. In order to prevent the deleterious effects caused by arsenic compounds, almost all living organisms have developed mechanisms to eliminate it. In this study genome-wide response of S. cerevisiae to arsenic shows that this metal interferes with genes involved in the iron homeostasis including those encoding proteins that function in iron uptake, incorporation into FeS clusters, and more. In addition our data indicate that Yap1 transcriptionally controls the iron homeostasis regulator AFT2 as well as its direct target, MRS4. Most importantly in response to arsenate exposure Yap1 strongly regulates the expression of several genes involved in the Fe-S proteins biosynthesis, namely NBP35 and YFH1. Interestingly mRNA levels encoding Fet3, Ferro-O2-oxidoreductase required for high-affinity iron uptake, are drastically destabilized upon arsenic exposure. Such destabilization is due to the 5 to 3 exonuclease Xrn1 localized in the P Bodies. Moreover FET3 mRNA decay is not mediated by Cth2 and is independent on the formation of ROS responsible for the toxic effects of arsenic compounds. Strikingly, in presence of arsenate fet3 mutant shows resistance over the wild-type which leads us to suggest that Fet3 has a role in arsenic toxicity. Unexpectedly arsenic treatment seems to activate the non-reductive iron uptake in order to maintain the cellular iron homeostasis. Furthermore our genetic, biochemical, and physiological analysis demonstrate that aft1 mutant is sensitive to arsenic compounds and such phenotype is reversible upon addition of iron. We also show that arsenic exposure induces iron deficiency in aft1 mutant. In conclusion this work shows for the first time that arsenic, a chemotherapy drug used to treat a specific type of acute promyelocytic leukemia (APL), disrupts iron homeostasis and our results suggest that this disruption is independent on ROS generation. Finally we provide preliminary data confirming that such disruption also takes place in mammalian cells, an observation that can be very relevant in term of clinical applications.
Arsenic stress elicits cytosolic Ca(2+) bursts and Crz1 activation in Saccharomyces cerevisiae.
Time
View SamplesWe used RNA sequencing to study gene expression in lymph node derived DCs from anaphylactic mice sensitized intranasally with the major peach allergen Pru p 3, during the acute reaction phase, induced intraperitoneally. In total, 237 genes changed significantly, 181 showing at least two-fold changes. Almost three quarters of these increased during anaphylaxis Overall design: 5 Female Balb/c mice aged 4-5 weeks, were sensitized to peach using intranasally administered Pru p 3 in combination with LPS and challenged intraperitoneally as described previously . 5 Littermates, treated with intranasally administered PBS (instead of Pru p 3 and LPS), and later given an intraperitoneal challenge as per the anaphylactic mice, were used for comparison.
Transcriptional Profiling of Dendritic Cells in a Mouse Model of Food-Antigen-Induced Anaphylaxis Reveals the Upregulation of Multiple Immune-Related Pathways.
Sex, Cell line, Treatment, Subject
View SamplesThe immune system relies on the plasticity of its components to produce appropriate responses to frequent environmental challenges. Dendritic cells (DCs) are critical initiators of innate immunity and orchestrate the later and more specific adaptive immunity. The generation of diversity in transcriptional programs is central for effective immune responses. Alternative splicing is widely considered a key generator of transcriptional and proteomic complexity, but its role has been rarely addressed systematically in immune cells. Here we used splicing-sensitive arrays to assess genome-wide gene- and exon-level expression profiles in human DCs in response to a bacterial challenge. We find widespread alternative splicing events and splicing factor transcriptional signatures induced by an E. coli challenge to human DCs. Alternative splicing acts in concert with transcriptional modulation, but these two mechanisms of gene regulation affect primarily distinct functional gene groups. Alternative splicing is likely to have an important role in DC immunobiology because it affects genes known to be involved in DC development, endocytosis, antigen presentation and cell cycle arrest
Genome-wide analysis of alternative splicing during dendritic cell response to a bacterial challenge.
Specimen part, Treatment
View SamplesDocetaxel is the standard first line therapy for hormone-refractory prostate cancer patients. Here we generated models of Docetaxel resistance in prostate cancer cells to study the molecular pathways that drive the acquisition of resistance to this therapy. We used microarrays to detail the global program of gene expression underlying the acquisition of Docetaxel resistance in prostate cancer cells.
Suppression of acquired docetaxel resistance in prostate cancer through depletion of notch- and hedgehog-dependent tumor-initiating cells.
Specimen part, Cell line
View SamplesThe combination of defined factors with small molecules targeting epigenetic factors is a strategy that has been shown to enhance optimal derivation of human iPSCs and could be used for therapeutic and regenerative medicine applications. In this study, we showed that a new first-in-class dual G9a/DNMT inhibitor CM272 compound improves the standard four-factor reprogramming efficiency of human fibroblast. The use of CM272 facilitates the generation of iPSC with only two factors, OCT4 and SOX2, allowing the removal of potentially oncogenic factors such as cMYC or KLF4. Taking a closer look at the early events occurring during cell reprogramming we demonstrated that treatment with our G9a/DNMT dual inhibitor induces heterochromatin relaxation, facilitates the engagement of OCT4 and SOX2 transcription factors to the genome and promotes mesenchymal to epithelial transition during cell reprogramming. Thus, the use of this new G9a/DNMT dual inhibitor compound may represent an interesting alternative for improving cell reprogramming.
Reversible dual inhibitor against G9a and DNMT1 improves human iPSC derivation enhancing MET and facilitating transcription factor engagement to the genome.
Sex, Specimen part, Disease, Cell line
View SamplesIn this study, genome-wide gene expression profiles of primary hepatocytes and liver sinusoidal endothelial cells (LSECs) were measured at day 12 for each cell culture system using Affymetrix GeneChips and analyzed via Gene Set Enrichment Analysis (GSEA). The culture systems analyzed include the commonly used collagen sandwich and monolayers of hepatocytes, as well as 3-dimensional (3D) engineered liver models that contain hepatocytes and LSECs (3DHL) and hepatocytes, LSECs, and Kupffer cells (3DHLK). Our results highlight the up-regulation of several hepatocyte specific functions in hepatocytes and a novel interplay between Ppara signaling and bile acid biosynthesis in LSECs.
Transcriptomic Analysis of Hepatic Cells in Multicellular Organotypic Liver Models.
Specimen part, Time
View SamplesThe Anopheles gambiae midgut harbors bacteria that proliferate upon a blood feed. We used microarrays to examine the midgut gene expression response at early stages (3hours) after an artifitial meal containing heat killed bacteria.
A peroxidase/dual oxidase system modulates midgut epithelial immunity in Anopheles gambiae.
Age, Specimen part
View SamplesPlasmacytoid dendritic cells (pDCs) are an immune subset devoted to the production of high amounts of type 1 interferons in response to viral infections. While conventional dendritic cells (cDCs) originate mostly from a common dendritic cell progenitor (CDP), pDCs have been shown to develop from both CDPs and common lymphoid progenitors (CLP). Here we found that pDCs developed predominantly from IL7R+ lymphoid progenitor cells. Expression of SiglecH and Ly6D defined pDC lineage commitment along the lymphoid branch. Transcriptional characterization of SiglecH+Ly6D+ precursors indicated that pDC development requires high expression of the transcription factor IRF8, while pDC identity relies on TCF4. RNA sequencing of IL7R+ lymphoid and CDP-derived pDCs mirrored the heterogeneity of mature pDCs observed by single-cell analysis. Both mature pDC subsets are able to secrete type 1 interferons, but only myeloid-derived pDCs share with cDCs their ability to process and present antigen. Overall design: Bulk RNA Seq was performed from sort purified DN, SP and DP lymphoid progenitors and BM pDCs of 4 individual mice
Distinct progenitor lineages contribute to the heterogeneity of plasmacytoid dendritic cells.
Specimen part, Cell line, Subject
View SamplesCell transformation by the Src tyrosine kinase is characterized by extensive changes in gene expression. To describe these changes, investigators have relied extensively on the study of immortalized rodent cell lines or heterogeneous tumor samples that limit the identification of differentially expressed genes or may not represent the full spectrum of biological processes regulated during transformation. In this study, we took advantage of transformation-deficient and temperature sensitive mutants of the Rous sarcoma virus to characterize the patterns of gene expression in two types of primary cells, namely chicken embryo fibroblasts (CEF) and chicken neuro-retinal (CNR) cells.
Cellular processes of v-Src transformation revealed by gene profiling of primary cells--implications for human cancer.
No sample metadata fields
View SamplesIn this study we conducted transcriptomics analyses of: (i) liver samples from patients suffering from acetaminophen-induced acute liver failure (n=3) and from healthy livers (n=2) and (ii) hepatic cell systems exposed to acetaminophen, including their respective vehicle controls. The investigated in vitro systems are: HepaRG cells, HepG2 cells and a novel human skinpostnatal stem cell-derived model i.e. human skin-precursors-derived hepatocyte-like cells (hSKP-HPC).
Gene expression data from acetaminophen-induced toxicity in human hepatic <i>in vitro</i> systems and clinical liver samples.
Specimen part, Disease stage, Cell line
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