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.
Circular RNA enrichment in platelets is a signature of transcriptome degradation.
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View SamplesExperiment: Establishment of expression profiles in a brain metastasis from a PTC (RNA processing and hybridization to Affymetrix microarray done twice to yield a technical replicate), in non-brain metastatic, stage III and IV PTCs, and primary brain tumors. Biostatistics analysis identified genes and biofunctions related to the brain metastatic PTC.
Microarray expression profiling identifies genes, including cytokines, and biofunctions, as diapedesis, associated with a brain metastasis from a papillary thyroid carcinoma.
Sex, Disease stage
View SamplesExperiment: Establishment of expression profiles in HT, PTC with HT, PTC without HT, and mPTC in comparison to TN samples. TN samples were downloaded as CEL files from the repository of the microarray vendor. Biostatistical analysis focussed in first instance on identifying genes and biofunctions related to HT and PTC with HT.
Genetic relationship between Hashimoto`s thyroiditis and papillary thyroid carcinoma with coexisting Hashimoto`s thyroiditis.
Sex, Disease
View SamplesIn order to identify potential genes that may play an important role in progression of colorectal carcinoma, we screened and validated the global gene expression using cDNA expression array on 36 CRC tissues and compared with 24 non-cancerous colorectal tissue.
Genome-wide expression analysis of Middle Eastern colorectal cancer reveals FOXM1 as a novel target for cancer therapy.
Sex
View SamplesExperiment: Expression profiling in breast cancer brain metastases (BC) compared to breast cancers (BC) and primary brain tumors (prBT). The objectives are to identify expression profiles that are specific to BCBM in order to identify new molecular biomarkers. The characterization of the BCBM samples included adjacent genetic techniques.
Comprehensive molecular biomarker identification in breast cancer brain metastases.
Sex, Specimen part, Disease stage
View SamplesBone mineral density (BMD) is a strong predictor of osteoporotic fracture. It is also one of the most heritable disease-associated quantitative traits. As a result, there has been considerable effort focused on dissecting its genetic basis. Here, we performed a genome-wide association study (GWAS) in a panel of inbred strains to identify associations influencing BMD. This analysis identified a significant (P=3.1 x 10-12) BMD locus on Chromosome 3@52.5 Mbp that replicated in two seperate inbred strain panels and overlapped a BMD quantitative trait locus (QTL) previously identified in a F2 intercross. The association mapped to a 300 Kbp region containing four genes; Gm2447, Gm20750, Cog6, and Lhfp. Â Further analysis found that Lipoma HMGIC Fusion Partner (Lhfp) was highly expressed in bone and osteoblasts and its expression was regulated by local expression QTL (eQTL) in multiple tissues. A co-expression network analysis revealed that Lhfp was strongly connected to genes involved in osteoblast differentiation. To directly evaluate its role in bone, Lhfp deficient mice (Lhfp-/-) were created using CRISPR/Cas9. Consistent with genetic and network predictions, bone marrow stromal cells (BMSCs) from Lhfp-/- displayed increased osteogenic differentiation. Lfhp-/- mice also had elevated BMD due to increased cortical bone mass. In conclusion, we used GWAS and systems genetics in mice to identify Lhfp as a regulator of osteoblast activity and bone mass. Overall design: Bones and osteoblast-derived from bone marrow stromal cells were profiles using RNA-seq from CC0016/GeniUnc mice (N=3 biological replicates per sample type)
Mouse genome-wide association and systems genetics identifies Lhfp as a regulator of bone mass.
Specimen part, Cell line, Subject
View SamplesCumulus cells are biologically distinct from other follicular cells and perform specialized roles, transmitting signals within the ovary and supporting oocyte maturation during follicular development. The bi-directional communication between the oocyte and the surrounding cumulus cells is crucial for the acquisition of oocyte competence. Using Illumina/deep-sequencing technology, we dissected the small RNAome of pooled human mature MII oocytes and cumulus cells. Overall design: Cumulus cells and MII mature oocytes small RNA profiles were generated by deep-sequencing, using Illumina 1G sequencer
MicroRNAs: new candidates for the regulation of the human cumulus-oocyte complex.
Specimen part, Subject
View SamplesTo analyze expression differences between Trp53 pro-and deficient as well as Atm pro- and deficient murine CLL tumors developing in the E-TCL1 mouse model, we analyzed splenocytes isolated from heavily infiltrated spleens of sick mice.
Two mouse models reveal an actionable PARP1 dependence in aggressive chronic lymphocytic leukemia.
Specimen part
View SamplesWe recently reported that carbon monoxide (CO) has bactericidal activity. To understand its mode of action we analysed the gene expression changes occurring when Escherichia coli, grown aerobically and anaerobically, is treated with the carbon monoxide releasing molecule, CORM-2. The E. coli microarray analysis shows that E. coli CORM-2 response is multifaceted with a high number of differentially regulated genes spread through several functional categories, namely genes involved in inorganic ion transport and metabolism, regulators, and genes implicated in posttranslational modification, such as chaperones. CORM-2 has higher impact in E. coli cells grown anaerobically, as judged by the existence of repressed genes belonging to eight functional classes which are absent in aerobically CORM-2 treated cells. In spite of the relatively stable nature of the CO molecule, our results show that CO is able to trigger a significant alteration in the transcriptome of E. coli which necessarily has effects in several key metabolic pathways.
Exploring the antimicrobial action of a carbon monoxide-releasing compound through whole-genome transcription profiling of Escherichia coli.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Retinoic acid is essential for Th1 cell lineage stability and prevents transition to a Th17 cell program.
Specimen part
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