HM1, HP1a-/-, and HP1b-/- ESC transcriptomes were generated to determine whether depletion of these HP1 proteins influences gene and/or retroelement expression Overall design: mRNA profiles of HP1a and HP1b Knockouts and its corresponding wildtype
Distinct roles of KAP1, HP1 and G9a/GLP in silencing of the two-cell-specific retrotransposon MERVL in mouse ES cells.
Specimen part, Subject
View SamplesThe Microarray study was designed to characterize the whole genome transcription profile of two subpopulations of H1 human embryonic stem cells we identified by size using flow cytometry.The heterogeneous nature of stem cells is an important issue in both research and therapeutic use in terms of directing cell lineage differentiation pathways, as well as self-renewal properties. Using flow cytometry we have identified two distinct subpopulations by size within the H1 and BGN1 human embryonic stem (hES) cell lines. Both populations express stem the cell markers Oct-4, Nanog, Tra-1-60, Tra-1-80 and SSea-4 and express very low levels of differentiation markers common to the three germ layers. To investigate if the two populations possessed different transcription profiles, we performed whole genome microarray analysis, and identified approximately 400 genes with significant differential expression (p<0.01). Cloning experiments indicate that both populations are able to repopulate each other and maintain the parental population. The large cell population responds to retinoic acid (RA) differentiation as evidenced by greater than a 50% loss of gated cell number and loss of Oct-4 expression; while the small cell population number does not change and maintains Oct-4 protein expression. The presence of these two populations could be vitally important with respect to stem cell therapy and research as they respond differently to differentiation signals, which may be important in directing stem cell differentiation for disease therapy.
Differential responses to retinoic acid and endocrine disruptor compounds of subpopulations within human embryonic stem cell lines.
Specimen part, Disease, Cell line
View SamplesWe have recently demonstrated that mycobacterial ligands engage Toll like receptor 2 (TLR2) on CD4+ T cells and up-regulate T-cell receptor (TCR) triggered- Th1 responses in vitro and in vivo.
Toll like Receptor 2 engagement on CD4<sup>+</sup> T cells promotes TH9 differentiation and function.
No sample metadata fields
View SamplesParathyroid hormone (PTH) plays an essential role in regulating calcium and bone homeostasis in the adult, but whether PTH is required at all for regulating fetal-placental mineral homeostasis is uncertain. To address this we treated Pth-null mice in utero with 1 nmol PTH (1-84) or saline and examined placental calcium transfer 90 minutes later. It was found that placental calcium transfer increased in Pth-null fetuses treated with PTH as compared to Pth-null fetuses treated with saline. Subsequently, to determine the effect of PTH treatment on placental gene expression, in a separate experiment, 90 minutes after the fetal injections the placentas were removed for subsequent RNA extraction and microarray analysis.
Parathyroid hormone regulates fetal-placental mineral homeostasis.
Sex, Specimen part, Treatment
View SamplesDNA methylation and histone H3 lysine 9 trimethylation (H3K9me3) play important roles in silencing of genes and retroelements. However, a comprehensive comparison of genes and repetitive elements repressed by these pathways has not been reported. Here we show that in mouse embryonic stem cells (mESCs), the genes up-regulated following deletion of the H3K9 methyltransferase Setdb1 are distinct from those de-repressed in mESC deficient in the DNA methyltransferases Dnmt1, Dnmt3a and Dnmt3b, with the exception of a small number of primarily germline-specific genes. Numerous endogenous retroviruses (ERVs) lose H3K9me3 and are concomitantly de-repressed exclusively in SETDB1 knockout mESCs. Strikingly, ~15% of up-regulated genes are induced in association with de-repression of promoter proximal ERVs, half in the context of "chimaeric" transcripts that initiate within these retroelements and splice to genic exons. Thus, SETDB1 plays a previously unappreciated yet critical role in inhibiting aberrant gene transcription by suppressing the expression of proximal ERVs. Overall design: NChIP-seq and mRNA-seq of WT, SETDB1 KO and DMNT1 TKO mESCs
DNA methylation and SETDB1/H3K9me3 regulate predominantly distinct sets of genes, retroelements, and chimeric transcripts in mESCs.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Vitamin C induces Tet-dependent DNA demethylation and a blastocyst-like state in ES cells.
Specimen part, Treatment, Time
View SamplesDNA methylation is a heritable epigenetic modification involved in gene silencing, imprinting, and the suppression of retrotransposons. Global DNA demethylation occurs in the early embryo and the germline and may be mediated by Tet (ten-eleven-translocation) enzymes, which convert 5-methylcytosine (mC) to 5-hydroxymethylcytosine (hmC). Tet enzymes have been extensively studied in mouse embryonic stem (ES) cells, which are generally cultured in the absence of Vitamin C, a potential co-factor for Fe(II) 2-oxoglutarate dioxygenase enzymes like Tets. Here we report that addition of Vitamin C to ES cells promotes Tet activity leading to a rapid and global increase in hmC. This is followed by DNA demethylation of numerous gene promoters and up-regulation of demethylated germline genes. Tet1 binding is enriched near the transcription start site (TSS) of genes affected by Vitamin C treatment. Importantly, Vitamin C, but not other antioxidants, enhances the activity of recombinant human Tet1 in a biochemical assay and the Vitamin C-induced changes in hmC and mC are entirely suppressed in Tet1/2 double knockout (Tet DKO) ES cells. Vitamin C has the strongest effects on regions that gain methylation in cultured ES cells compared to blastocysts and in vivo are methylated only after implantation. In contrast, imprinted regions and intracisternal A-particle (IAP) elements, which are resistant to demethylation in the early embryo, are resistant to Vitamin C-induced DNA demethylation. Collectively, this study establishes that Vitamin C is a direct regulator of Tet activity and DNA methylation fidelity in ES cells.
Vitamin C induces Tet-dependent DNA demethylation and a blastocyst-like state in ES cells.
Specimen part
View SamplesWe had previously discovered that the transcription factor Cited2 was highly induced during trophoblast differentiation. In this study, we used an lentiviral shRNA strategy to decrease Cited2 expression in Rcho-1 trophoblast cells. A RNA-seq approach was used to determine global transcript differences inRcho-1 knockdown cells compared to control cells. Overall design: Rcho-1 cells transduced with control shRNAs were used as controls. Cells transduced with shRNAs targetingCited2 were used as treatment.Cells were differentiated for 8 days and the analyses were done.
CITED2 modulation of trophoblast cell differentiation: insights from global transcriptome analysis.
No sample metadata fields
View SamplesGenetic ablation of the maintenance methyltransferase Dnmt1 induces widespread demethylation and transcriptional activation of CpG-rich IAP (intracisternal A particle) proviruses. Here, we report that this phenomenon is not simply a consequence of loss of DNA methylation. By exploiting conditional deletions of Dnmt1 and Np95, each of which is essential for maintenance methylation, we find that while IAPs are indeed de-repressed in Dnmt1-ablated embryos and embryonic stem cells (ESCs), these proviruses remain silenced in Np95-ablated cells, despite similar kinetics of passive demethylation. Paradoxically, transient IAP activation in Dnmt1-ablated ESCs requires the presence of NP95. We subsequently show that in the absence of NP95, the H3K9 methyltransferase SETDB1 maintains IAP silencing; while in the absence of DNMT1, prolonged binding of NP95 to hemimethylated DNA perturbs SETDB1-dependent H3K9me3 deposition. Taken together, these observations reveal that following acute loss of Dnmt1, H3K9 methylation-dependent IAP silencing is disrupted by aberrant NP95 binding to hemimethylated DNA. Overall design: RNA-seq for Np95, Dnmt1 and Setdb1 wt, single conditional KO (cKO) and double cKO ES cells; RRBS-seq for Dnmt1 and Np95 single and double cKO ESCs; Myc-tagged NP95, DNMT1 ChIP-seq; and wt and Np95wt and cKO H3K9me3 ChIP-seq.
Activation of Endogenous Retroviruses in Dnmt1(-/-) ESCs Involves Disruption of SETDB1-Mediated Repression by NP95 Binding to Hemimethylated DNA.
Subject, Time
View SamplesTranscriptomic analysis of fresh breast cancer tissue versus normal tissues. The Study comprising 45 Saudi-Arabian subjects was designed to take advantage of transcriptomics to prospectively explore the roles of lifestyle and genetic susceptibility in the occurrence of breast cancer.
Expression of matrix metalloproteinases (MMPs) in primary human breast cancer: MMP-9 as a potential biomarker for cancer invasion and metastasis.
Specimen part, Disease stage
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