The molecular chaperone heat shock protein 90 (HSP90) is thought to buffer genetic variation uncoupling phenotypic outcome from individual genotypes. HSP90 thus acts as an evolutionary capacitor by facilitating an accumulation of natural genetic variation. The molecular mechanism underlying the buffering ability is unclear, and HSP90-contingent genetic variation maps both to coding and non-coding parts of the genome. Our genome-wide data indicate that a compromised chaperoning activity of HSP90 causes derepression of endogenous retroviruses (ERVs) in mouse somatic cells. This results in an upregulation of host genes located in the neighborhood of pre-existing ERVs insertion sites. We provide genetic and biochemical evidence that HSP90 cooperates with KAP1/ SETDB1 histone methyltranferase pathway to repress ERVs. Individual mouse strains have unique integration sites of ERVs in their genomes. Consequently distinct genes are responsive to HSP90 inhibitor in different mouse strains depending on the position of the genes vis-Ã -vis strain-specific ERV insertion sites. Since ERVs have been exapted to drive novel transcriptional networks during mammalian evolution, HSP90 may have acted as a capacitor by buffering variation caused by ERV in non-coding regions of the genome. Our studies provide the first molecular framework by which HSP90 can mitigate genetic variation in gene-regulatory regions affecting gene expression and phenotypes. Overall design: We have performed RNA-seq in mouse embryonic stem cells, neuronal progenitor cells and bone-marrow-derived macrophages treated with NVP-AUY922 in triplicates.
The evolutionary capacitor HSP90 buffers the regulatory effects of mammalian endogenous retroviruses.
Specimen part, Subject
View SamplesTo provide a global study of transcriptome changes under drought stress, the gene expression levels of a durum wheat genotype (Triticum durum Desf. cultivar Creso) and two bread wheat genotypes (Triticum aestivum L. cultivar Chinese Spring -CS- and its deletion line CS_5AL-10) were investigated. The 5A chromosome deletion line (5AL-10) lacks the distal part (43%) of the long arm of chromosome 5A. Each genotype was subjected to two different levels of water stress at the grain filling stage. After anthesis, three different levels of soil water content (SWC) were induced as described below: control (CTRL; SWC=28%), moderate stress (MS; SWC=18%), and severe stress (SS; SWC=12.5%). For each sample, three biological replicates were performed, for a total of 27 hybridizations. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Alessio Aprile. The equivalent experiment is TA23 at PLEXdb.]
Transcriptional profiling in response to terminal drought stress reveals differential responses along the wheat genome.
Specimen part, Treatment
View SamplesThe knowledge of an expression network signature in end-stage heart failure (HF) diseased hearts may offer important insights into the complex pathogenesis of advanced cardiac failure, as well as it may provide potential targets for therapeutic intervention. In this study, the NGS sequencing of RNA (RNA-Seq) method was employed to obtain the whole transcriptome of cardiac tissues from transplant recipients with advanced stage of HF. The analysis of RNA-Seq data presents novel challenges and many methods have been developed for the purpose of mapping reads to genomic features and quantifying gene expression. The main goal of this work was to identify, characterize and catalogue all the transcripts expressed within cardiac tissue and to quantify the differential expression of transcripts in both physio- and pathological conditions through whole transcriptome analyses. Expression levels, differential splicing, allele-specific expression, RNA editing and fusion transcripts constitute important information when comparing samples for disease related studies. Analysis methods for RNA-Seq data are continuing to evolve. Thus, in order to find the best solution for filter generated list of differentially expressed genes, an informatic approach of NOISeq BIO method has been applied in this RNA-Seq analysis. Most of the genes obtained by filtering differentially expressed gene list, have been experimentally validated by Real time RT-PCR. Noteworthy, these findings provide valuable resources for further studies of the molecular mechanisms involved in heart ischemic response thus leading to potential novel biomarkers and targets for therapeutic intervention in the onset and progression of cardiomyopathies. Overall design: Heart biopsies from candidates for solid organ transplantation were collected and their RNA samples were used for high-throughput sequencing purposes. Libraries were sequenced on the Illumina HiSeq2000 NGS platform.
Heart failure: Pilot transcriptomic analysis of cardiac tissue by RNA-sequencing.
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View SamplesCase report of a twin pair with concordant JMML, but with a different disease course predicted by gene expression profiling
Different outcomes of allogeneic hematopoietic stem cell transplant in a pair of twins affected by juvenile myelomonocytic leukemia.
Specimen part, Disease
View SamplesComparison between in vitro transcription- and cDNA-mediated annealing, selection and ligation (DASL)-based assays on brain-specific reference RNA, and postmortem frozen and formalin fixed brain tissue from autistic and control cases. Investigation of data preprocessing techniques for DASL-assayed RNA samples from frozen brain tissue.
Preprocessing and Quality Control Strategies for Illumina DASL Assay-Based Brain Gene Expression Studies with Semi-Degraded Samples.
Specimen part, Disease
View SamplesMicroarray-based gene expression analysis of peripheral whole blood is a common strategy in the development of clinically relevant biomarker panels for a variety of human diseases. However, the results of such an analysis are often plagued by decreased sensitivity and reliability due to the effects of relatively high levels of globin mRNA in whole blood. Globin reduction assays have been shown to overcome such effects, but they require large amounts of total RNA and may induce distinct gene expression profiles. The Illumina whole-genome DASL (WG-DASL) assay can detect gene expression levels using partially degraded RNA samples and has the potential to detect rare transcripts present in highly heterogeneous whole blood samples without the need for globin reduction. We therefore assessed the utility of the WG-DASL assay in the analysis of peripheral whole blood gene expression profiles. We find that gene expression detection is significantly increased with the use of WG-DASL compared to the standard in vitro transcription-based direct hybridization (IVT), while globin-probe-negative WG-DASL did not exhibit significant improvements over globin-probe-positive WG-DASL. Globin reduction increases the detection sensitivity and reliability of both WG-DASL and IVT with little effect on raw intensity correlations: raw intensity correlations between total RNA and globin-reduced RNA were 0.970 for IVT and 0.981 for WG-DASL. Overall, the detection sensitivity of the WG-DASL assay is higher than the IVT-based direct hybridization assay, with or without globin reduction, and should be considered in conjunction with globin reduction methods for future blood-based gene expression studies.
Gene expression profiling of human whole blood samples with the Illumina WG-DASL assay.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genetic and genomic analyses of RNA polymerase II-pausing factor in regulation of mammalian transcription and cell growth.
Specimen part, Treatment
View SamplesMany mammalian genes are occupied by paused RNA polymerase II (pol II) at promoter-proximal regions on both sides of transcription start sites (TSSs). However, the consequences of pol II pausing on gene expression and cell biology are not fully understood. Here we report that genetic ablation of the b subunit of mouse negative elongation factor (Nelf-b), a key pol II-pausing factor, results in slower progression at multiple cell cycle stages and increased apoptosis. Consistently, a whole-genome analysis indicates that growth and cell death-related genes are highly enriched among the direct target genes of Nelf-b. In particular, Nelf-b deletion increases pol II density in the promoter-distal region of stress response genes and their overall expression levels in the absence of any external stress signals. In addition, our work also reveals a previously unappreciated role of Nelf-b role in curbing TSS-upstream transcription of many mammalian genes. We suggest that Nelf-mediated pol II pausing balances the cellular needs for growth/survival and stress response by preventing excessive basal transcription of stress-induced genes.
Genetic and genomic analyses of RNA polymerase II-pausing factor in regulation of mammalian transcription and cell growth.
Specimen part, Treatment
View SamplesBACKGROUND: Streptococcus pneumoniae, the pneumococcus, is the main etiological agent of pneumonia. Pneumococcal infection is initiated by bacterial adherence to lung epithelial cells. The exact transcriptional changes occurring in both host and microbe during infection are unknown. Here, we developed a time-resolved infection model of human lung alveolar epithelial cells by S. pneumoniae and assess the resulting transcriptome changes in both organisms simultaneously by using dual RNA-seq. RESULTS: Functional analysis of the time-resolved dual RNA-seq data identifies several features of pneumococcal infection. For instance, we show that the glutathione-dependent reactive oxygen detoxification pathway in epithelial cells is activated by reactive oxygen species produced by S. pneumoniae. Addition of the antioxidant resveratrol during infection abates this response. At the same time, pneumococci activate the competence regulon during co-incubation with lung epithelial cells. By comparing transcriptional changes between wild-type encapsulated and mutant unencapsulated pneumococci, we demonstrate that adherent pneumococci, but not free-floating bacteria, repress innate immune responses in epithelial cells including expression of the chemokine IL-8 and the production of antimicrobial peptides. We also show that pneumococci activate several sugar transporters in response to adherence to epithelial cells and demonstrate that this activation depends on host-derived mucins. CONCLUSIONS: We provide a dual-transcriptomics overview of early pneumococcal infection in a time-resolved manner, providing new insights into host-microbe interactions. To allow easy access to the data by the community, a web-based platform was developed ( http://dualrnaseq.molgenrug.nl ). Further database exploration may expand our understanding of epithelial-pneumococcal interaction, leading to novel antimicrobial strategies. Overall design: 5 time points are analysed (0, 30, 60, 120 and 240 minutes after infection). Each time point has two biological replicates except for the 240 mpi. Furthermore, each time point has two pneumococcal strains used to infect A549 cells, encapsulated and unencapsulated pneumococci. In total there are 18 samples. cellular infection model, contains rRNA-depleted total RNA from A549 epithelial cells and D39 S. pneumoniae
Time-resolved dual RNA-seq reveals extensive rewiring of lung epithelial and pneumococcal transcriptomes during early infection.
Specimen part, Cell line, Subject
View SamplesPrevious studies have shown that ischemia alters gene expression in normal and malignant tissues. There are no studies that evaluated effects of ischemia in renal tumors. This study examines the impact of ischemia and tissue procurement conditions on RNA integrity and gene expression in renal cell carcinoma.
Impact of ischemia and procurement conditions on gene expression in renal cell carcinoma.
Specimen part, Treatment, Subject
View Samples