To explore the global mechanisms of estrogen-regulated transcription, we used chromatin immunoprecipitation coupled with DNA microarrays to determine the localization of RNA polymerase II (Pol II), estrogen receptor alpha (ERalpha), steroid receptor coactivator proteins (SRC), and acetylated histones H3/H4 (AcH) at estrogen-regulated promoters in MCF-7 cells with or without estradiol (E2) treatment. In addition, we correlated factor occupancy with gene expression and the presence of transcription factor binding elements. Using this integrative approach, we defined a set of 58 direct E2 target genes based on E2-regulated Pol II occupancy and classified their promoters based on factor binding, histone modification, and transcriptional output. Many of these direct E2 target genes exhibit interesting modes of regulation and biological activities, some of which may be relevant to the onset and proliferation of breast cancers. Our studies indicate that about one-third of these direct E2 target genes contain promoter-proximal ERalpha-binding sites, which is considerably more than previous estimates. Some of these genes represent possible novel targets for regulation through the ERalpha/AP-1 tethering pathway. Our studies have also revealed several previously uncharacterized global features of E2-regulated gene expression, including strong positive correlations between Pol II occupancy and AcH levels, as well as between the E2-dependent recruitment of ERalpha and SRC at the promoters of E2-stimulated genes. Furthermore, our studies have revealed new mechanistic insights into E2-regulated gene expression, including the absence of SRC binding at E2-repressed genes and the presence of constitutively bound, promoter-proximally paused Pol IIs at some E2-regulated promoters. These mechanistic insights are likely to be relevant for understanding gene regulation by a wide variety of nuclear receptors.
Genomic analyses of transcription factor binding, histone acetylation, and gene expression reveal mechanistically distinct classes of estrogen-regulated promoters.
No sample metadata fields
View SamplesIncreasing evidence provide support that the mammalian liver contains stem/progenitor cells, but their molecular phenotype, embryological derivation, cell biology as well as of their role in the liver cell turnover and regeneration remain to be further clarified.
Isolation and characterization of a murine resident liver stem cell.
No sample metadata fields
View SamplesLeaf transcriptome comparison of untransformed Col-0 Arabidopsis plants with plants transformed to be anti-sense for AtAOX1a (alternative oxidase). Two bio-replicates were sampled, for a total of four microarray chipsCol-0 and anti-sense leaf tissue from a first planting (samples GSM45208 and GSM45231, respectively), and from a second planting made one week later (samples GSM45209 and GSM45278, respectively). See sample descriptions for growth conditions and microarray procedure.
Characterization of transformed Arabidopsis with altered alternative oxidase levels and analysis of effects on reactive oxygen species in tissue.
No sample metadata fields
View SamplesMurine healthy tissue samples, DCIS and invasive mammary tumors were analyzed in order to identify marker genes which show enhanced expresssion in DCIS and invasive ductal carcinomas.
Identification of early molecular markers for breast cancer.
Specimen part
View SamplesHuman healthy tissue samples, DCIS and invasive mammary tumors were analyzed in order to identify marker genes which show enhanced expresssion in DCIS and invasive ductal carcinomas.
Identification of early molecular markers for breast cancer.
Specimen part, Disease, Disease stage
View SamplesDifferencies between groups between pre and post haematopoietic stem cell transplantation children
Genetic Background of Immune Complications after Allogeneic Hematopoietic Stem Cell Transplantation in Children.
Specimen part, Disease stage
View SamplesDifferences between groups of children with obesity and healthy controls.
Looking for new diagnostic tools and biomarkers of hypertension in obese pediatric patients.
Specimen part, Disease
View SamplesO-GlcNAcylation is an essential, nutrient-sensitive post-translational modification, but its biochemical and phenotypic effects remain incompletely understood. To address this knowledge gap, we investigated the global transcriptional response to perturbations in O-GlcNAcylation. Unexpectedly, many transcriptional effects of O-GlcNAc transferase (OGT) inhibition were due to the activation of NRF2, the master regulator of redox stress tolerance. Moreover, we found that a signature of low OGT activity strongly correlates with NRF2 activation in multiple tumor expression datasets. Guided by this information, we identified KEAP1 (also known as KLHL19), the primary negative regulator of NRF2, as a direct substrate of OGT. We show that O-GlcNAcylation of KEAP1 at serine 104 is required for the efficient ubiquitination and degradation of NRF2. Interestingly, O-GlcNAc levels and NRF2 activation co-vary in response to glucose fluctuations, indicating that KEAP1 O-GlcNAcylation links nutrient sensing to downstream stress resistance. Our results reveal a novel regulatory connection between nutrient-sensitive glycosylation and NRF2 signaling, and provide a blueprint for future approaches to discover functionally important O-GlcNAcylation events on other KLHL family proteins in various experimental and disease contexts.
Glycosylation of KEAP1 links nutrient sensing to redox stress signaling.
Specimen part, Cell line
View SamplesPrevious studies have reported that microglia depletion leads to impairment of synapse formation and these cells rapidly repopulate from CNS progenitors. However, the impact of microglia depletion and repopulation on the long-term state of the CNS environment has not been characterized. Here, we found by RNA-seq analysis that acute and synchronous microglia depletion results in a type 1-interferon inflammatory signature in degenerating somatosensory cortex in microglia-depleted mice. Transcriptomic and mass cytometry analysis of repopulated microglia demonstrates an interferon regulatory factor 7-driven activation state. Minocycline and anti-IFNAR1 antibody treatment attenuate the CNS type-1 interferon-driven inflammation and restore microglia homeostasis. Together, we found that acute microglia ablation induces a type-1 interferon activation state of grey matter microglia associated with acute neurodegeneration. Overall design: RNAseq analysis of brain cortical tissue from control and microglia-depleted mice.
Acute microglia ablation induces neurodegeneration in the somatosensory system.
Specimen part, Subject
View SamplesWe identified genes whose expression changes between stage 8 and stage 10. We also identified genes whose expression was altered in stage 10 from temperature senstive ecdysone receptor mutant flies raised at the restrictive temperature. The experiments showed a significant number of genes that are upregulated in stage 10 depend EcR-mediated signaling. Overall design: 3 samples x 3 repeats
Steroid Signaling Establishes a Female Metabolic State and Regulates SREBP to Control Oocyte Lipid Accumulation.
Sex, Specimen part, Cell line, Subject
View Samples