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SRP058654
Homo sapiens
1 Downloadable Sample
IlluminaHiSeq2000
Description
In platelets, splicing and translation occur in the absence of a nucleus. However, the integrity and stability of mRNAs derived from megakaryocyte progenitor cells remain poorly quantified on a transcriptome-wide level. As circular RNAs (circRNAs) are resistant to degradation by exonucleases, their abundance relative to linear RNAs can be used as a surrogate marker for mRNA stability in the absence of transcription. Here we show that circRNAs are enriched in human platelets 17-188 fold relative to nucleated tissues, and 14-26 fold relative to samples digested with RNAseR to selectively remove linear RNA. We compare RNAseq read depths inside and outside circRNAs to provide in silico evidence of transcript circularity, show that exons within circRNAs are enriched ~13X in platelets relative to nucleated tissues, and identify 3162 genes significantly enriched for circRNAs including some where all RNAs appear to be derived from circular molecules. We also confirm that this is a feature of other anucleate cells through transcriptome sequencing of mature erythrocytes, demonstrate that circRNAs are not enriched in megakaryocytes, and that linear RNAs decay more rapidly than circRNAs in platelet preparations. Collectively, these results suggest that circulating platelets have lost on aveage over 90% of their progenitor mRNAs, and that translation in platelets occurrs against the backdrop of a highly degraded transcriptome. Finally, we find that transcripts classified as products of reverse transcriptase template switching are both enriched in platelets and resistant to decay, countering the recent suggestion that up to 50% of rearranged RNAs are artefacts. Overall design: A single rRNA depleted total RNA sample was sequenced. This together with 25 publicly available rRNA depleted total RNA samples (including 3 from platelets) were analysed using PTESFinder v 1 (http://sourceforge.net/projects/ptesfinder-v1/) to identify back-splice junctions, characteristic of circRNA transcripts. The contribution of circRNA producing exons was analysed on a gene by gene basis as follows: All circRNA transcripts identified in any sample were first pooled to define exons which can contribute to circRNA generation using custom scripts (available on request). For each sample, expression estimates (RPKMI) across all circRNA producing exons were computed for each locus using the total size of exons (in bp) and the read counts mapping to them. Similarly, total size and exonic read counts for exons for which no circRNA were detected in any sample were used to compute expression estimates (RPKME) for non-circRNA producing exons for each locus. Abundance ratios (RPKMI/RPKME and RPKMI/RPKMI+RPKME) were calculated and compared between Platelets and human tissues using Wilcoxon signed-rank test. Please note that the ''25sample_info_accn_no.txt'' contains the accession numbers and tissue/cell type information for 25 samples analyzed together.
Publication Title
Circular RNA enrichment in platelets is a signature of transcriptome degradation.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 8 Downloadable Samples
- Illumina HiSeq 4000
Description
Red blood cells (RBCs) mature within a specialized niche (the erythroblastic island (EI)), which consists of a central macrophage surrounded by differentiating erythroblasts. Human Induced Pluripotent Stem Cell derived macrophages (iPSC-DMs) enhance proliferation and terminal maturation of Umbilical Cord Blood (UCB) CD34+ derived erythroid cells and iPSC derived erythroid cells. These effects are further increased when an inducible KLF1-ERT2 fusion protein is activated in iPSC-DMs. To assess the mechanism of action, we sought to compare the transcriptome of iPSC-DMs with and without KLF1 activation. For this, we used an inducible IPSC line (iKLF1.2) in which upon tamoxifen addition, the KLF1 transcription factor is translocated to nucleus and consequently KLF1 downstream targets are expressed. The identification and characterisation of could identify factors involved in erythroid maturation and thus helpful to improve current protocols to manufacture RBCs in vitro. Overall design: iKLF1.2 iPSCs were differentiated to macrophages and then split into 2 groups, one was treated with tamoxifen for the last 4 days of culture to activate KLF1. The other group was not treated with tamoxifen. Four biologically independent differentiation experiments were carried out and so 8 samples were generated: 4 samples of untreated iKLF1.2 iPSCs-derived macrophages and 4 samples of tamoxifen treated iKLF1.2 iPSC-derived macrophages. Total RNA was extracted from each sample and RNA integrity was of a high enough quality for library preparation, as all RIN values were above 9 for every sample.
Publication Title
Genetic programming of macrophages generates an in vitro model for the human erythroid island niche.
Sample Metadata Fields
Specimen part, Treatment, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The underlying mechanisms which are responsible and govern early haematopoietic differentiation during development are poorly understood. Gene expression comparison between pluripotent human embryonic stem cells and earliest haematopoietic progenitors may reveal novel transcripts and pathways and provide crucial insight into early haematopoietic lineage specification and development.
Publication Title
Large-scale transcriptional profiling and functional assays reveal important roles for Rho-GTPase signalling and SCL during haematopoietic differentiation of human embryonic stem cells.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 48 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
PTTG1 overexpression in adrenocortical cancer is associated with poor survival and represents a potential therapeutic target.
Sample Metadata Fields
Sex, Age, Specimen part, Disease stage
View Samples- Homo sapiens
- 48 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Background: Adrenocortical carcinoma (ACC) is associated with poor survival rates. The objective of the study was to analyze ACC gene expression profiling data prognostic biomarkers and novel therapeutic targets.
Publication Title
PTTG1 overexpression in adrenocortical cancer is associated with poor survival and represents a potential therapeutic target.
Sample Metadata Fields
Sex, Disease stage
View Samples- Arabidopsis thaliana
- 15 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized.
Publication Title
Penetration of the stigma and style elicits a novel transcriptome in pollen tubes, pointing to genes critical for growth in a pistil.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
Loss of the interactions between lymphotoxin and its receptor was associated with MZM apoptotic cell clearance defects in BXD2 mice whereas loss of IFNAR in BXD2 mice normalized the function of MZMs. The analysis also intended to use MZMs isolated from BXD2-Ifnar-/- mice and BXD2 mice treated with sLTbR-Fc to identify the common pathways regulating the MZM function in these mice.
Publication Title
Interferon-induced mechanosensing defects impede apoptotic cell clearance in lupus.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 16 Downloadable Samples
- Illumina HiSeq 2000
Description
High throughput massively parallel sequencing on mRNA libraries generated from cortices of bexarotene or vehicle treated APP/PS1 Overall design: Read counts analyzed for differential gene expression using edgeR
Publication Title
RNA-sequencing reveals transcriptional up-regulation of Trem2 in response to bexarotene treatment.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Muscle injury was elicited by cardiotoxin injection into the tibialis anterior muscle. Macrophages were isolated 2 days post-injury from the regenerating muscle.
Publication Title
Tissue LyC6- macrophages are generated in the absence of circulating LyC6- monocytes and Nur77 in a model of muscle regeneration.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 15 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
To study the gene expression profile of salivary glands with varying degrees of inflammation in Sjogren's and non Sjogren's patients
Publication Title
Chitinases in the salivary glands and circulation of patients with Sjögren's syndrome: macrophage harbingers of disease severity.
Sample Metadata Fields
Specimen part, Disease
View Samples