We used oligonucleotide microarrays to address the specificities of transcriptional responses of adult Drosophila to different stresses induced by paraquat and H2O2, two oxidative stressors, and by tunicamycin which induces an endoplasmic reticulum (ER) stress. Flies were tested 24 hours after exposure to continuous stresses induced by ingestion of paraquat, H2O2 or tunicamycin at concentrations leading to similar effects on viability. We used concentrations of 1% H2O2, 5mM paraquat and 12uM of tunicamycin which lead to negligeable mortality at 24 hours. A paraquat concentration of 15mM was also used for comparison with previous studies Both specific and common responses to the three stressors were observed and whole genome functional analysis identified several important classes of stress responsive genes. Within some functional classes, we observed large variabilities of transcriptional changes between isozymes, which may reflect unsuspected functional specificities.
Genome wide analysis of common and specific stress responses in adult drosophila melanogaster.
Sex, Age, Compound, Time
View SamplesIkaros hypomorphic mice (IkL/L) show plasmacytoid dendritic cell (pDC) defects with an absence of pDCs in the peripheral organs and a reduction of pDCs in the bone marrow (BM). Moreover in vitro differentiation of pDC from IkL/L total BM cells is also defective.
Ikaros cooperates with Notch activation and antagonizes TGFβ signaling to promote pDC development.
Treatment
View SamplesTo assess the importance of the Wnt pathway during T cell develoment, we generated a mouse line (R26-cat) in which high levels of active -catenin are maintained throughout T cell development. Young R26-cat mice (6-week-old) show a differentiation block at the CD4+CD8+ DP stage. All R26-cat mice develop T cell leukemias with a DP phenotype at 5-6 months of age.
β-Catenin activation synergizes with Pten loss and Myc overexpression in Notch-independent T-ALL.
Age, Specimen part
View SamplesThe SAGA co-activator has been implicated in the regulation of a smal subset of genes in budding yeast in transcriptomic analyses performed in steady-state levels of RNA.
SAGA Is a General Cofactor for RNA Polymerase II Transcription.
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View SamplesRNA Pol II transcription has been implied to be either regulated by the general transcription factor TFIID or the co-activator SAGA. Also, this dominancy of either SAGA or TFIID might be according to the existance, or not, of a TATA consensus sequence.
Transcription of Nearly All Yeast RNA Polymerase II-Transcribed Genes Is Dependent on Transcription Factor TFIID.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
DNA methylation fingerprint of neuroblastoma reveals new biological and clinical insights.
Specimen part
View SamplesDNA methylation changes in neuroblastoma, a clinically-heterogeneous pediatric tumor, have been described essentially in promoter regions. We analyzed the DNA methylome of neuroblastoma using high-density microarrays and observed differential methylation not only in promoters but also in intragenic and intergenic regions at both CpG and non-CpG sites. These epigenetic changes showed a non-random distribution relative functional chromatin domains, and targeted development and cancer-related genes, relevant for neuroblastoma pathogenesis. CCND1, a gene overexpressed in neuroblastoma, showed hypomethylation of gene-body and upstream regulatory regions. Furthermore, tumors with diverse clinical-risk showed clear differences affecting CpG and, remarkably, non-CpG sites. Non-CpG methylation was present in clinically-favorable tumors and affected genes such as ALK, where non-CpG methylation correlated with low gene expression. Finally, we identified CpG and non-CpG methylation signatures which correlated with patients age at time-points relevant for neuroblastoma clinical behavior, and targeted genes related to neural development and neural crest regulatory network
DNA methylation fingerprint of neuroblastoma reveals new biological and clinical insights.
Specimen part
View SamplesSteroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production.
A cell-autonomous molecular cascade initiated by AMP-activated protein kinase represses steroidogenesis.
Specimen part, Treatment
View SamplesGene expression profiling of the inferior and superior wall of the distal midgestation arterial domain (outflow tract) of the wild type CD1 mouse embryonic heart
Tbx1 coordinates addition of posterior second heart field progenitor cells to the arterial and venous poles of the heart.
Specimen part
View SamplesWe used microarrays to detail the global gene expression signature of PDAC and to identify distinct up- and down-regulated transcripts in these tumors compared to control pancreas. We also established from this dataset the metabolic signature of PDAC in order to define new metabolic therapeutic target for pancreatic cancer.
Cholesterol uptake disruption, in association with chemotherapy, is a promising combined metabolic therapy for pancreatic adenocarcinoma.
Sex, Age, Specimen part
View Samples