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SRP110626
Drosophila melanogaster
9 Downloadable Samples
Illumina HiSeq 2500
Description
The goal of this study was to generate a Drosophila model of intellectual disability caused by mutations in kdm5. RNA-seq was used to define the transcriptional defects of a mutation in Drosophila that is analogous to a human intellectual disability-associated allele, kdm5[A512p]. These data revealed a total of 1609 dysregulated genes, 778 of which were upregulated and 831 were downregulated. To determine whether these transcriptional defects were due to the loss of KDM5-induced histone demethylation, we also carried out RNA-seq from a enzymatic inactive strain, kdm5[Jmjc*]. These data revealed a striking similarity between the two datasets and suggest that the primary defect of KDM5[A512P] is loss of histone demethylase activity. Overall design: 3-5 day old adult heads from wildtype, kdm5[A512P] and kdm5[JmjC*] were used to generate RNA that was subsequently subjected to deep sequencing.
Publication Title
A Drosophila Model of Intellectual Disability Caused by Mutations in the Histone Demethylase KDM5.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2000
Description
Argonaute (Ago) proteins mediate post-transcriptional gene repression by binding guide microRNAs (miRNAs) to regulate targeted RNAs. To confidently assess Agobound small RNAs, we adapted a mouse embryonic stem cell system to express a single inducible epitope-tagged Ago protein. Here, we report the small RNA profile of Agodeficient cells and determine Ago-dependent stability is a common feature of mammalian miRNAs. Considering both in vivo Ago-dependence for stability and Ago2 binding as defined by immunopurification, we have identified a novel class of non-canonical miRNAs derived from protein-coding gene promoters, which we name transcriptional start site miRNAs (TSS-miRNAs). A subset of promoter-proximal RNA polymerase II complexes produce hairpin RNAs that are processed in a DGCR8/Drosha-independent, but Dicer-dependent manner. TSS-miRNA activity is detectable endogenously, upon transfection of a mimic or by mRNA overexpression. Finally, we present evidence of differential expression and conservation in humans, suggesting important roles in gene regulation. Overall design: Examination of Ago immunoprecipitations and mESC without Ago proteins
Publication Title
Argonaute-bound small RNAs from promoter-proximal RNA polymerase II.
Sample Metadata Fields
Specimen part, Treatment, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
Target competition (ceRNA crosstalk) within miRNA-regulated gene networks has been proposed to influence biological systems. To assess target competition, we characterize and quantitate miRNA networks in two cell types. Argonaute iCLIP reveals that hierarchical binding of high to low affinity miRNA targets is a key characteristic of in vivo activity. Quantification of cellular miRNA and mRNA/ncRNA target pool levels indicates that miRNA-Target pool ratios and an affinity partitioned target pool accurately predict in vivo Ago binding profiles and miRNA susceptibility to target competition. Using single-cell reporters, we directly test predictions and estimate ~3,000 additional high affinity target sites can affect active miRNA families with low endogenous miRNA-Target ratios, such as miR-92/25. In contrast, the highly expressed miR-294 and let-7 families are not susceptible to increases of nearly 10,000 sites. These results show differential susceptibility based on endogenous miRNA-Target pool ratios and provide a physiological context for ceRNA competition in vivo. Overall design: mRNA seq from TT-FHAgo2 mouse embryonic stem cells or Meschencymal stem cells grown with 2.5 µg/mL Dox to express Ago2 or removed from doxycycline for 96h.
Publication Title
Endogenous miRNA and target concentrations determine susceptibility to potential ceRNA competition.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus, Homo sapiens, Rattus norvegicus
- 1938 Downloadable Samples
Affymetrix Rat Gene 2.0 ST Array (ragene20st), Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2), Affymetrix Rat Expression 230A Array (rae230a), Affymetrix HT HG-U133+ PM Array Plate (hthgu133pluspm), Affymetrix Rat Genome 230 2.0 Array (rat2302), Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Age, Specimen part, Treatment, Subject, Time
View Samples- Rattus norvegicus
- 119 Downloadable Samples
Affymetrix Rat Gene 2.0 ST Array (ragene20st), Affymetrix Rat Expression 230A Array (rae230a)
Description
The carcinogenic potential of chemicals is currently evaluated with rodent life-time bioassays, which are time consuming, and expensive with respect to cost, number of animals and amount of compound required. For insight into early mechanisms of non-genotoxoc carcinogenesis and for identification of potential early biomarkers of non-genotoxic carcinogenesis, groups of rats were treated with a range of known non-genotoxic carcinogens for a period of 14, 28, or 90 days, and liver tissue was harvested for expression profiling. Control groups were treated with appropriate vehicles.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Treatment
View Samples- Mus musculus
- 40 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Specimen part, Treatment, Subject
View Samples- Rattus norvegicus
- 60 Downloadable Samples
- Affymetrix Rat Expression 230A Array (rae230a), Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Conventional notion regards the action of non-genotoxic carcinogens (NGC) an autonomous process largely confined to parenchymal cells. Here we aim to elucidate the role of the hepatic mesenchyme for the action of two prototypical NGC, phenobarbital (PB), an anti-epileptic drug, and cyproterone acetate (CPA) a gestagen used in contraceptive pills.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Rattus norvegicus
- 47 Downloadable Samples
- Affymetrix Rat Expression 230A Array (rae230a), Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Here we investigate the difference in global gene expression in different tumor types found in the liver of rats after NNM-initiation/PB-promotion of tumor growth. We aim to identify tumor characteristic expression in nodules, focii, adenomas and carcinomas.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Mus musculus
- 40 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Evidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Specimen part, Treatment, Subject
View Samples- Mus musculus
- 23 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Signaling through the Wnt/b-catenin pathway is a crucial determinant of hepatic zonal gene expression, liver development, regeneration, and tumorigenesis. The gene encoding b-catenin is called Ctnnb1. We have previously shown, that liver tumour promotion mediated by the model tumour promoter phenobarbital (PB) is completely lost in mice, where Ctnnb1 has been conditionally knocked out in hepatocytes (CTNNB1KO mice; Rignall et al., Carcinogenesis 32, 52-57, 2010). In the present study, the effect of a 12 weeks PB exposure on the liver miRNA expression pattern was investigated, in order to potentially get information on the nature of the loss of promotional activity in the CTNNB1KO mice.
Publication Title
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sample Metadata Fields
Sex, Specimen part
View Samples