MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in many cellular pathways. MiRNAs associate with members of the Argonaute (Ago) protein family and bind to partially complementary sequences on mRNAs and induce translational repression or mRNA decay. MiRNA expression can be controlled by transcription factors and can therefore be cell type- or tissue-specific. Here we have analyzed miRNA expression profiles in murine monocyte-derived dendritic cells (DCs) and macrophages upon stimulation with LPS, LDL, eLDL and oxLDL to identify not only stimuli-specific miRNA, but also to identify a hierarchical miRNA system involving miR-155. For this, miR-155 knockout dendritic cells and macrophages were also sequenced using the same stimuli. Overall design: Sequencing of murine monocyte-derived dendritic cells and macrophages (each wild type and miR-155 knock out cells) matured and stimulated, respectively, by LPS, oxLDL, eLDL or LDL.
A miR-155-dependent microRNA hierarchy in dendritic cell maturation and macrophage activation.
Specimen part, Cell line, Subject
View SamplesmicroRNAs (miRNAs) are small non-coding RNAs that function in literally all cellular processes. miRNAs interact with Argonaute (Ago) proteins and guide them to specific target sites located in the 3’ untranslated region (UTR) of target mRNAs leading to translational repression and deadenylation-induced mRNA degradation. Most miRNAs are processed from hairpin-structured precursors by the consecutive action of the RNase III enzymes Drosha and Dicer. However, processing of miR-451 is Dicer-independent and cleavage is mediated by the endonuclease Ago2. Here we have characterized miR-451 sequence and structure requirements for processing as well as sorting of miRNAs into different Ago proteins. Pre-miR-451 appears to be optimized for Ago2 cleavage and changes result in reduced processing. In addition, we show that the mature miR-451 only associates with Ago2 suggesting that mature miRNAs are not exchanged between different members of the Ago protein family. Based on cloning and deep sequencing of endogenous miRNAs associated with Ago1-3, we do not find evidence for miRNA sorting in human cells. However, Ago identity appears to influence the length of some miRNAs, while others remain unaffected. Overall design: Examination of miRNAs associated with endogenous human Ago1-4 in HeLa cells
microRNAs associated with the different human Argonaute proteins.
No sample metadata fields
View SamplesThe 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. Since the results of these 2-year bioassays are not known until quite late during development of new chemical entities, and since the short-term test battery to test for genotoxicity, a characteristic of genotoxic carcinogens, is hampered by low specificity, the identification of early biomarkers for carcinogenicity would be a big step forward. Using gene expression profiles from the livers of rats treated up to 14 days with genotoxic and non-genotoxic carcinogens we previously identified characteristic gene expression profiles for these two groups of carcinogens. We have now added expression profiles from further hepatocarcinogens and from non-carcinogens the latter serving as control profiles. We used these profiles to extract biomarkers discriminating genotoxic from non-genotoxic carcinogens and to calculate classifiers based on the support vector machine (SVM) algorithm. These classifiers then predicted a set of independent validation compound profiles with up to 88% accuracy, depending on the marker gene set. We would like to present this study as proof of the concept that a classification of carcinogens based on short-term studies may be feasible.
Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Specimen part
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Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Sex, Specimen part
View SamplesIn this study we performed microarray-based molecular profiling of liver samples from Wistar rats exposed to genotoxic carcinogens (GC), nongenotoxic carcinogens (NGC) or non-hepatocarcinogens (NC) for up to 14 days. In contrast to previous toxicogenomics studies aimed at the inference of molecular signatures for assessing the potential and mode of compound carcinogenicity, we considered multi-level omics data. Besides evaluating the predictive power of signatures observed on individual biological levels, such as mRNA, miRNA and protein expression, we also introduced novel feature representations which capture putative molecular interactions or pathway alterations by integrating expression profiles across platforms interrogating different biological levels.
Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Sex, Specimen part
View SamplesFaithful execution of developmental programs relies on the acquisition of unique cell identities from pluripotent progenitors, a process governed by combinatorial inputs from numerous signaling cascades that ultimately dictate lineage-specific transcriptional outputs. Despite growing evidence that metabolism is integrated with many molecular networks, how pathways that control energy homeostasis may affect cell fate decisions is largely unknown. Here, we show that AMPK, a central metabolic regulator, plays critical roles in lineage specification. Although AMPK-deficient embryonic stem cells (ESCs) were normal in the pluripotent state, these cells displayed profound defects upon differentiation, failing to generate chimeric embryos and preferentially adopting an ectodermal fate at the expense of the endoderm during embryoid body (EB) formation. AMPK-/- EBs exhibited reduced levels of Tfeb, a master transcriptional regulator of lysosomes, leading to diminished endolysosomal function. Remarkably, genetic loss of Tfeb also yielded endodermal defects, while AMPK-null ESCs over-expressing this transcription factor normalized their differential potential, revealing an intimate connection between Tfeb/lysosomes and germ layer specification. The compromised endolysosomal system resulting from AMPK or Tfeb inactivation blunted Wnt signaling, while up-regulating this pathway restored expression of endodermal markers. Collectively, these results uncover the AMPK pathway as a novel regulator of cell fate determination during differentiation. Overall design: 2 WT and 2 AMPK DKO ESC lines were differentiated into embryoid bodies (EBs) for various lengths of time (2, 4, 8, and 12 days) in high and low glucose conditions. Both ESC and EB samples were profiled by mRNA-seq to examine how global gene expression changes associated with ESC differentiation are affected by AMPK deletion.
AMPK governs lineage specification through Tfeb-dependent regulation of lysosomes.
Specimen part, Subject
View SamplesAssessing the carcinogenic potential of drug candidates is a costly procedure which requires the life-long treatment of rodents at different dose levels. A promising approach, which may to a certain degree reduce the need for animal studies in the future is toxicogenomics. The idea is to employ microarray platforms for the genome-wide expression profiling of compounds, which may facilitate the discovery of biomarker genes and provide insights in molecular mechanisms.
A toxicogenomic approach for the prediction of murine hepatocarcinogenesis using ensemble feature selection.
Sex, Specimen part, Treatment, Time
View SamplesIn order to comprehensively identify RNA-expression changes after p53-activation, total RNA was isolated and subjected to next generation seqencing (RNA-Seq) after activation of a conditional p53 allele in SW480 cells. Overall design: SW480/pRTR-p53-VSV cells were subjected to RNA-Seq analysis after 48 hours doxycycline-treatment.
p53-Regulated Networks of Protein, mRNA, miRNA, and lncRNA Expression Revealed by Integrated Pulsed Stable Isotope Labeling With Amino Acids in Cell Culture (pSILAC) and Next Generation Sequencing (NGS) Analyses.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Ha-ras and β-catenin oncoproteins orchestrate metabolic programs in mouse liver tumors.
Sex, Specimen part
View SamplesThe process of hepatocarcinogenesis in the diethylnitrosamine (DEN) initiation/phenobarbital (PB) promotion mouse model involves the selective clonal outgrowth of cells harboring oncogene mutations in Ha-ras, B-raf, or Ctnnb1. Here, we have characterized mouse liver tumors harboring either Ctnnb1 or Ha-ras mutations via integrated molecular profiling at the transcriptional and translational and post-translational levels. In addition, metabolites of the intermediary metabolism were quantified by high resultion 1H magic angle nuclear magnetic resonance (HR-MAS NMR). We have identified tumor characteristic genotype-specific differences in mRNA and miRNA expression, protein levels, and post-translational modifications and in metabolite levels that facilitate the molecular and biochemical stratification of tumor phenotypes. Bioinformatic integration of these data at the pathway level led to novel insights into tumor genotype-specific aberrant cell signaling and in particular to a better understanding of alterations in pathways of the cell intermediary metabolism, which are driven by the constitutive activation of the -Catenin and Ha-ras oncoproteins in tumors of the two genotypes.
Ha-ras and β-catenin oncoproteins orchestrate metabolic programs in mouse liver tumors.
Sex, Specimen part
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