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E-MTAB-1430
Gallus gallus
12 Downloadable Samples
Affymetrix Chicken Genome Array (chicken)
Description
The microarray analysis was designed to test the effects of HES5.3 siRNAs, Atoh7 siRNAs and nt siRNAs on gene expression in embryonic chick retina.
Publication Title
A positive feedback loop between ATOH7 and a Notch effector regulates cell-cycle progression and neurogenesis in the retina.
Sample Metadata Fields
Age, Specimen part
View Samples- Homo sapiens
- 6 Downloadable Samples
Ion Torrent Proton
Description
Background: Whole transcriptome sequencing (RNA-seq) represents a powerful approach for whole transcriptome gene expression analysis. However, RNA-seq carries a few limitations, e.g., the requirement of a significant amount of input RNA and complications led by non-specific mapping of short reads. The Ion AmpliSeqTM Transcriptome Human Gene Expression Kit (AmpliSeq) was recently introduced by Life Technologies as a whole-transcriptome, targeted gene quantification kit to overcome these limitations of RNA-seq.To assess the performance of this new methodology, we performed a comprehensive comparison of AmpliSeq with RNA-seq using two well-established next-generation sequencing platforms (Illumina HiSeq and Ion Torrent Proton). We analyzed standard reference RNA samples and RNA samples obtained from human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs). Results: Using published data from two standard RNA reference samples, we observed a strong concordance of log2 fold change for all genes when comparing AmpliSeq to Illumina HiSeq (Pearson’s r=0.92) and Ion Torrent Proton (Pearson’s r=0.92). We used ROC, Matthew’s correlation coefficient and RMSD to determine the overall performance characteristics. All three statistical methods demonstrate AmpliSeq as a highly accurate method for differential gene expression analysis. Additionally, for genes with high abundance, AmpliSeq outperforms the two RNA-seq methods. When analyzing four closely related hiPSC-CM lines, we show that both AmpliSeq and RNA-seq capture similar global gene expression patterns consistent with known sources of variations. Conclusions: Our study indicates that AmpliSeq excels in the limiting areas of RNA-seq for gene expression quantification analysis. Thus, AmpliSeq stands as a very sensitive and cost-effective approach for very large scale gene expression analysis and mRNA marker screening with high accuracy. Overall design: Comprehensive, performance evaluation of AmpliSeq Transcriptome to standard whole-transcriptome RNA-sequencing methods for large-scale, genome-wide differential gene expression analysis. We analyzed standard reference RNA samples and RNA samples obtained from human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs).
Publication Title
Comprehensive evaluation of AmpliSeq transcriptome, a novel targeted whole transcriptome RNA sequencing methodology for global gene expression analysis.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 32 Downloadable Samples
Description
Although epigenetic mechanisms, such as specific histone modifications, control common and cell-specific genetic programs, a role for histone modifying enzymes in liver metabolism and disease has not been investigated. This report demonstrates that the combined loss of the histone methyltransferases EZH1 and EZH2 in mouse hepatocytes led to the disruption of H3K27me3 homeostasis by age three months, simple fatty liver by age six months and fatal fibrosis by age 15 months. Global and gene-specific reduction of H3K27me3 marks paralleled a concomitant increase of H3K4me3 marks at genes associated with chronic liver disease. Advanced disease was accompanied by widespread infiltration of immune cells, an increase of activated hepatic stellate cells and collagen deposition. Expression of genes from the cytochrome P450 family that control drug metabolism was already deregulated by age two months and mice were fatally hypersensitive to carbon tetrachloride (CCl4). These genetic experiments, for the first time, illustrate that the simple loss of EZH1/EZH2, which results in the disruption of epigenetic modifications, is sufficient for the progression of fatal liver disease. Overall design: RNA-seq and ChIP-seq were performed in liver tissues.
Publication Title
The methyltransferases enhancer of zeste homolog (EZH) 1 and EZH2 control hepatocyte homeostasis and regeneration.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 13 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
OBF1, also known as Bob.1 or OCA-B, is a B lymphocyte-specific transcription factor which coactivates Oct1 and Oct2 on B cell specific promoters. So far, the function of OBF1 has been mainly identified in late stage B cell populations. The central defect of OBF1 deficient mice is a severely reduced immune response to T cell-dependent antigens and a lack of germinal center formation in the spleen. Relatively little is known about a potential function of OBF1 in developing B cells. Here we have generated transgenic mice overexpressing OBF1 in B cells under the control of the immunoglobulin heavy chain promoter and enhancer. Surprisingly, these mice have greatly reduced numbers of follicular B cells in the periphery and have a compromised immune response. Furthermore, B cell differentiation is impaired at an early stage in the bone marrow. A first block is observed during B cell commitment and a second differentiation block is seen at the large preB2 cell stage. The cells that succeed to escape the block and to differentiate into mature B cells have post-translationally downregulated the expression of transgene, indicating that expression of OBF1 beyond the normal level early in B cell development is deleterious. Indeed ID3, which is a negative regulator of B cell differentiation, is upregulated in the EPLM and preB cells of the transgenic mice. Furthermore ID3 promoter contains an octamer site suggesting that it is a potential OBF-1 direct target gene. These results provide evidence that OBF1 expression has to be tightly regulated in early B cells to allow efficient B lymphocyte differentiation.
Publication Title
Enforced expression of the transcriptional coactivator OBF1 impairs B cell differentiation at the earliest stage of development.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Expression 430A Array (moe430a)
Description
The chromatin regulator Aiolos and the transcriptional coactivator OBF-1 have been implicated in regulating aspects of B cell maturation and activation. Mice lacking either of these factors have a largely normal early B cell development. However, when both factors are eliminated simultaneously a block is uncovered at the transition between pre-B and immature B cells, indicating that these proteins exert a critical function in developing B lymphocytes. In mice deficient for Aiolos and OBF-1, the numbers of immature B cells are reduced, small pre-BII cells are increased and a significant impairment in immunoglobulin light chain DNA rearrangement is observed. We identified genes whose expression is deregulated in the pre-B cell compartment of these mice. In particular, we found that components of the pre-BCR, such as the surrogate light chain genes l5l5 and VpreB, fail to be efficiently silenced in double-mutant mice. Strikingly, developmentally regulated nuclear repositioning of the l5l5 gene is impaired in pre-B cells lacking OBF-1 and Aiolos. These studies uncover a novel role for OBF-1 and Aiolos in controlling the transcription and nuclear organization of genes involved in pre-BCR function.
Publication Title
Silencing and nuclear repositioning of the lambda5 gene locus at the pre-B cell stage requires Aiolos and OBF-1.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
RNA expression profiling of human iPSC-derived cardiomyocytes in a cardiac hypertrophy model.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Cardiac hypertrophy is an independent risk factor for cardiovascular disease and heart failure. There is increasing evidence that microRNAs (miRNAs) play an important role in the regulation of messenger RNA (mRNA) and the pathogenesis of various cardiovascular diseases. However, the ability to comprehensively study cardiac hypertrophy on a gene regulatory level is impacted by the limited availability of human cardiomyocytes. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) offer the opportunity for disease modeling.
Publication Title
RNA expression profiling of human iPSC-derived cardiomyocytes in a cardiac hypertrophy model.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 124 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Hepatocellular carcinoma (HCC) is a heterogeneous disease, and despite considerable research efforts, no molecular classification of HCC has been introduced in clinical practice. The existing molecular classification systems were established using resected tumors, which introduces a selection bias towards patients without liver cirrhosis and with early stage HCCs. So far, these classification systems have not been validated in liver biopsy specimens from tumors diagnosed at intermediate and late stages. We generated and analyzed expression profiles from 60 HCC biopsies from an unselected patient population with all tumor stages. Unbiased clustering identified 3 HCC classes. Class membership correlated with survival, tumor size, and with Edmondson and BCLC stage. Most biopsy specimens could be assigned to the classes of published classification systems, demonstrating that gene expression profiles obtained from patients with early stage disease are preserved in all stages of HCC. When a reference set of healthy liver samples was integrated in the analysis, we observed that the differentially regulated genes up- or down-regulated in a given class relative to other classes were actually dysregulated in the same direction in all HCCs, with quantitative rather than qualitative differences between the molecular subclasses. With the exception of a subset of samples with a definitive -catenin gene signature, biological pathway analysis could not identify class specific pathways reflecting the activation of distinct oncogenic programs. Our results suggest that gene expression profiling of HCC biopsies has limited potential to direct therapies that target specific driver pathways, but can identify subgroups of patients with different prognosis.
Publication Title
Gene expression analysis of biopsy samples reveals critical limitations of transcriptome-based molecular classifications of hepatocellular carcinoma.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Homo sapiens
- 8 Downloadable Samples
- Illumina Genome Analyzer IIx
Description
We attempted to identify alterations in gene expression that occur during the progression from normal breast to ductal carcinoma in situ (DCIS) with the aim to elucidate significant genes and pathways underlying the premalignant transformation. To determine the expression changes that are common to multiple DCIS models (MCF10.DCIS, SUM102 and SUM225) and normal mammary epithelial cells (MCF10A), we grew the cells in three dimensional overlay culture with reconstituted basement membrane and used the extracted RNA for 76 cycles of deep sequencing (mRNA-Seq) using Illumina Genome Analyzer GAIIx. Analysis of mRNA-Seq results showed 295 consistently differentially expressed transcripts in DCIS models as compared to MCF10A. These differentially expressed genes are associated with a number of signaling pathways such as integrin, fibroblast growth factor and TGFß signaling. Many differentially expressed transcripts in DCIS were found to be involved in cell-cell signaling, cell-cell adhesion and cell proliferation. We further investigated ALDH5A1 gene that encodes for the enzyme, aldehyde dehydrogenase 5A1, which is involved in glutamate metabolism. Further, inhibition of ALDH5A1 with different pharmacological drugs resulted in significant inhibition of cell growth and proliferation in the DCIS models. Overall design: Four cell lines examined: normal mammary epithelial cell line (one sample) and three ductal carcinoma in situ cell lines (three samples). Each sample has two duplicates
Publication Title
RNA-Seq of human breast ductal carcinoma in situ models reveals aldehyde dehydrogenase isoform 5A1 as a novel potential target.
Sample Metadata Fields
Disease, Cell line, Subject
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
LDL or Ox-LDL 200ug/ml, which showed no loss of viability after a 48 hour exposure, induced a physiological and pathological transcriptional response, respectively. LDL induced a downregulation of genes associated with cholesterol biosynthesis while ox-LDL induced transcriptional alterations in genes related to inflammation, matrix expansion, lipid metabolism and processing, and apoptosis. Pentraxin-3 was secreted into the culture medium after RPE cells were stimulated with ox-LDL, and immunohistochemically evident in Bruchs membrane of human macular samples with age-related macular degeneration. ARPE-19 cells exposed to 200?g/ml ox-LDL had a 38% apoptosis rate compared to less than 1% when exposed to LDL or untreated controls (p<0.0001).
Publication Title
Oxidized low density lipoproteins induce a pathologic response by retinal pigmented epithelial cells.
Sample Metadata Fields
No sample metadata fields
View Samples