Adjacent alternative 3’ splice sites, those separated by =18nt, provide a unique problem in the study of alternative splicing regulation; there is overlap of the cis-elements that define the adjacent sites. Identification of the intron''s 3'' end depends upon sequence elements that define the branchpoint, polypyrimidine tract and terminal AG dinucleotide. Starting with RNA-seq data from germline-enriched and somatic cell-enriched C. elegans samples, we identify hundreds of introns with adjacent alternative 3’ splice sites. We identify 203 events that undergo tissue-specific alternative splicing. For these, the regulation is mono-directional, with somatic cells preferring to splice at the distal 3'' splice site and germline cells showing a distinct shift towards usage of the adjacent proximal 3'' splice site. Splicing patterns in somatic cells follow consensus rules of 3’ splice site definition, using sites with a short stretch of pyrimidines and an AG dinucleotide. Splicing in germline cells occurs at proximal 3'' splice sites that frequently lack a polypyrimidine tract or, occasionally, the AG dinucleotide. We provide evidence that use of germline-specific proximal 3'' splice sites is conserved across Caenorhabditis species. We propose that divergent mechanisms exist between germline and somatic cells in determining an intron terminus at adjacent alternative 3’ splice sites. Overall design: Examination of alternative splicing changes between germline- and somatic-cell enriched samples as well as nonsense-mediated decay mutants.
Coordinated tissue-specific regulation of adjacent alternative 3' splice sites in C. elegans.
Specimen part, Cell line, Subject
View SamplesEmbryonic chicken telencephalon nuclei were isolated for RNAseq to identify transcripts differentially expressed across different brain regions.
Neocortical Association Cell Types in the Forebrain of Birds and Alligators.
Sex, Specimen part
View SamplesCD4+ cells from Foxp3.eGFP mice containing Foxp3- Teff and Foxp3+ Treg cells were treated with anti-CD3/CD28 monoclonal antibodies or soluble OX40L and JAG1 for 3 days to induce TCR-dependent vs TCR-independent Treg proliferation. Untreated fresh CD4+ T-cells used as control. Post treatment T-cell proliferation was confirmed by Cell Trace violet dilution and Foxp3+ (Treg) and Foxp3-(Teff) were sorted. Differential gene expression profiling between Tregs and Teff cells among control, anti-CD3/CD28 and OX40L-JAG1 treated cultured was performed using affymetrix mouse gene 2.0 ST micro array.
OX40L-JAG1-Induced Expansion of Lineage-Stable Regulatory T Cells Involves Noncanonical NF-κB Signaling.
Specimen part, Treatment
View SamplesRoom temperature whole blood mRNA stabilization procedures, such as the PAX gene system, are critical for the application of transcriptional analysis to population-based clinical studies. Global transcriptome analysis of whole blood RNA using microarrays has proven to be challenging due to the high abundance of globin transcripts that constitute 70% of whole blood mRNA in the blood. This is a particular problem in patients with sickle-cell disease, secondary to the high abundance of globin-expressing nucleated red blood cells and reticulocytes in the circulation . In order to more accurately measure the steady state whole blood transcriptome in sickle-cell patients, we evaluated the efficacy of reducing globin transcripts in PAXgene stabilized RNA samples for genome-wide transcriptome analyses using oligonucleotide arrays. We demonstrate here by both microarrays and Q-PCR that the globin mRNA depletion method resulted in 55-65 fold reduction in globin transcripts in whole blood collected from healthy volunteers and sickle-cell disease patients. This led to an improvement in microarray data quality with increased detection rate of expressed genes and improved overlap with the expression signatures of isolated peripheral blood mononuclear (PBMC) preparations. The differentially modulated genes from the globin depleted samples had a higher correlation coefficient to the 112 genes identified to be significantly altered in our previous study on sickle-cell disease using PBMC preparations. Additionally, the analysis of differences between the whole blood transcriptome and PBMC transcriptome reveals important erythrocyte genes that participate in sickle-cell pathogenesis and compensation. The combination of globin mRNA reduction after whole-blood RNA stabilization represents a robust clinical research methodology for the discovery of biomarkers for hematologic diseases and in multicenter clinical trials investigating a wide range of nonhematologic disorders where fractionation of cell types is impracticable.
Characterization of whole blood gene expression profiles as a sequel to globin mRNA reduction in patients with sickle cell disease.
Specimen part, Subject
View SamplesWe are investigating the response of human lymphoblastoid cells to low-dose exposure of environmental metals
Comparative genomic analyses identify common molecular pathways modulated upon exposure to low doses of arsenic and cadmium.
Cell line, Treatment
View SamplesThe ER stress inducing agent Thapsigargin (TG) and/or the cytoprotective agent Salubrinal were applied to lymphoblastoid cell lines. TG induced lytic replication as well as a distinct pattern of gene expression changes. This study was designed to identify host genes mediating lytic replication secondary to ER stress.
Endoplasmic reticulum stress causes EBV lytic replication.
Specimen part, Treatment, Time
View SamplesThe response of cells to hypoxia is characterised by co-ordinated regulation of many genes. Studies of the regulation of the expression of many of these genes by oxygen has implicated a role for the heterodimeric transcription factor hypoxia inducible factor (HIF). The mechanism of oxygen sensing which controls this heterodimeric factor is via oxygen dependent prolyl and asparaginyl hydroxylation by specific 2-oxoglutarate dependent dioxygenases (PHD1, PHD2, PHD3 and FIH-1). Whilst HIF appears to have a major role in hypoxic regulation of gene expression, it is unclear to what extent other transcriptional mechanisms are also involved in the response to hypoxia. The extent to which 2-oxoglutarate dependent dioxygenases are responsible for the oxygen sensing mechanism in HIF-independent hypoxic gene regulation is also unclear. Both the prolyl and asparaginyl hydroxylases can be inhibited by dimethyloxalylglycine (DMOG). Such inhibition can produce activation of the HIF system with enhanced transcription of target genes and might have a role in the therapy of ischaemic disease. We have examined the extent to which the HIF system contributes to the regulation of gene expression by hypoxia, to what extent 2-oxoglutarate dependent dioxygenase inhibitor can mimic the hypoxic response and the nature of the global transcriptional response to hypoxia. We have utilised microarray assays of mRNA abundance to examine the gene expression changes in response to hypoxia and to DMOG. We demonstrate a large number of hypoxically regulated genes, both known and novel, and find a surprisingly high level of mimicry of the hypoxic response by use of the 2-oxoglutarate dependent dioxygenase inhibitor, dimethyloxalylglycine. We have also used microarray analysis of cells treated with small interfering RNA (siRNA) targeting HIF-1alpha and HIF-2alpha to demonstrate the differing contributions of each transcription factor to the transcriptional response to hypoxia. Candidate transcripts were confirmed using an independent microarray platform and real-time PCR. The results emphasise the critical role of the HIF system in the hypoxic response, whilst indicating the dominance of HIF-1alpha and defining genes that only respond to HIF-2alpha.
Concordant regulation of gene expression by hypoxia and 2-oxoglutarate-dependent dioxygenase inhibition: the role of HIF-1alpha, HIF-2alpha, and other pathways.
No sample metadata fields
View SamplesTo identify the driver factors in liver metastasis of colorectal cancer, and seek for possible biomarkers, we applied array trascriptome detection using approaches tailored to FFPE derived RNA
Weighted gene co-expression network analysis of colorectal cancer liver metastasis genome sequencing data and screening of anti-metastasis drugs.
Specimen part
View SamplesIn addition to gaining knowledge on in vivo miRNA responses to formaldehyde, we set out to relate these miRNA responses to transcriptional profiles modified by formaldehyde. Rats were exposed by inhalation to either 0 or 2 ppm formaldehyde (6 hours/day) for 28 days. Genome-wide transcriptional profiles and associated signaling pathways were assessed within the nasal respiratory mucosa and circulating mononuclear white blood cells (WBC).
Formaldehyde-associated changes in microRNAs: tissue and temporal specificity in the rat nose, white blood cells, and bone marrow.
Sex, Specimen part, Treatment, Time
View SamplesDifferentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12 or interferon-a/b (signal 3). Interaction of naive CD8 T cells with antigen and B7-1 programs cell division and proliferation whereas the presence of cytokines- IL-12 or IFNa/b promote survival, differentiation and memory establishment. In the absence of signal 3, the cells interacting with antigen/B7-1 undergo tolerance induction. The objective of this study was to elucidate the mechanisms how the provision of signal 3 promotes differentiation and averts tolerance induction in CD8 T cells. Trichostatin A is a pharmacological agent that inhibits histone deacetylase activity, hence regulating chromatin structure and gene expression and differentiation in many cell types. Gene signature profiles of IL-12, IFNa/b and trichostatin A stimulated cells were compared to elucidate the molecular mechanisms of gene regulation.
Gene regulation and chromatin remodeling by IL-12 and type I IFN in programming for CD8 T cell effector function and memory.
Age, Specimen part, Time
View Samples