The 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 SamplesEffects of hyperglycaemia and genetic background differences on renal gene expression
Comparative analysis of methods for gene transcription profiling data derived from different microarray technologies in rat and mouse models of diabetes.
Sex, Age, Specimen part, Disease, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below. Purpose: Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) causes several lymphoproliferative disorders, including KS, a common AIDS-associated malignancy. Cellular and viral microRNAs (miRNAs) have been shown to play important roles in regulating the expression of genes in oncogenesis. Herpesviruses, including KSHV, encode for miRNAs that are involved in angiogenesis, inflammation and apoptosis. A better knowledge of the miRNA-mediated pathways that regulate KSHV infection is therefore essential for an improved understanding of viral infection and pathogenesis. Methods: In this study, we used deep sequencing to analyze miRNA, both viral and human, and mRNA expression in KS tumor-derived human cells. Results: This approach revealed 153 differentially expressed human miRNAs between KSHV-positive and -negative cells. Differential expression of eight miRNAs was independently confirmed by qRT-PCR. We additionally showed that a majority (~73%) of KSHV-regulated miRNAs are down-regulated, including most members of the 14q32 miRNA cluster. Specifically, human miR-409-3p, which is known to target the pro-angiogenic growth factor angiogenin and the inflammation marker fibrinogen-beta, was significantly down-regulated in KSHV-infected cells based on deep sequencing and qRT-PCR. Despite this substantial down-regulation of cellular miRNAs, hsa-miR-708-5p was significantly up-regulated by KSHV and has been shown to directly inhibit pro-apoptotic protease Caspase-2. Finally, we evaluated to what extent there was an inverse correlation between miRNA and mRNA expression levels. Using filtered datasets, we identified relevant canonical pathways that were significantly enriched. Conclusion: Taken together, our data demonstrate that most human miRNAs affected by KSHV are repressed and our findings highlight the relevance of studying the post-transcriptional gene regulation of miRNAs for KSHV-associated malignancies. Overall design: Refer to individual Series. 6 samples analyzed (one cell type). Two experimental conditions: uninfected vs. chronically KSHV-infected cells (n=3). Two sequencing platforms: microRNA-Seq and mRNA-Seq.
Next-Generation Sequencing Analysis Reveals Differential Expression Profiles of MiRNA-mRNA Target Pairs in KSHV-Infected Cells.
No sample metadata fields
View SamplesPurpose: We aimed to identify miRNAs which are induced by the Activin/Nodal effectors, P-Smad2/3, in order to further our understanding of how P-Smad2/3 controls downstream gene expression in mouse ES cells to regulate crucial biological processes. Methods: We used a previously developed Tetracycline-On (Tet-On) system (TAG1) to manipulate the levels of P-Smad2/3 in mouse ES cells and performed an Illumina deep-sequencing screen to identify miRNAs which followed the P-Smad2/3 pathway. Results: We filtered the deep-seq data to identify a list of 28 miRNAs which showed a >1.25 fold increase in response to P-Smad2/3 induction and a >1.25 fold decrease in response to P-Smad2/3 repression. Conclusions: Our study represents a comprehensive global profiling of miRNA expression in response to changes in P-Smad2/3 levels in mouse ES cells. Overall design: miRNA profiles of TAG1 cells which were untreated (control), SB-431541 treated (P-Smad2/3 repressed), or Dox treated (P-Smad2/3 induced), were generated using Illumina GAII.
TGF-β/Smad2/3 signaling directly regulates several miRNAs in mouse ES cells and early embryos.
Specimen part, Subject
View SamplesProstate organogenesis involves epithelial growth in response to inductive signalling from specialised subsets of mesenchyme. To identify regulators and morphogens active in mesenchyme, we performed transcriptomic analysis using Tag-seq, RNA-seq, and single cell RNA-seq and defined new mesenchymal subsets and markers. We documented transcript expression using Tag-seq and RNA-seq in female rat Ventral Mesenchymal Pad (VMP) as well as adjacent urethra comprised of smooth muscle and peri-urethral mesenchyme. Transcripts enriched in VMP were identified in Tag-seq data from microdissected tissue, and RNA-seq data derived from cell populations and single cells. We identified 400 transcripts as enriched or specific to the VMP using bio-informatic comparisons of Tag-seq and RNA-seq data. Comparison with single cell RNA-seq identified transcripts yielded 45 transcriptscommon to both approaches. Cell subset analysis showed that VMP and adjacent mesenchyme were composed of distinct cell types and that each tissue was comprised of two subgroups. Markers for these subgroups were highly subset specific. Thirteen transcripts were validated by qPCR to confirm cell specific expression in microdissected tissues, as well as expression in neonatal prostate. Immunohistochemical staining demonstrated that Ebf3 and Meis2 showed a restricted expression pattern in VMP condensed mesenchyme. Taken together, we demonstrate that the VMP shows limited cellular heterogeneity and that our high-resolution transcriptomic analysis identified new mesenchymal subset markers associated with prostate organogenesis. Overall design: Tag-sequencing, RNA-sequencing and single-cell RNA-sequencing on 2 female inductive mesenchymal tissues of the developing prostate/urogenital tract.
Identification of genes expressed in a mesenchymal subset regulating prostate organogenesis using tissue and single cell transcriptomics.
No sample metadata fields
View SamplesOBJECTIVE: MicroRNAs (miRNAs, miRs), a class of small non-coding RNA molecules, are posttranscriptional regulators involved in a plethora of cellular functions and have been proposed as potential therapeutic targets in various diseases, including rheumatoid arthritis (RA). In this study, we sought to discover novel miR associations in synovial fibroblasts (SFs), a key cell type mediating RA pathogenesis, by performing miR expression profiling on cells isolated from the human TNF transgenic mouse model (TghuTNF or Tg197). METHODS: miR expression in SFs isolated from 8-week-old, fully diseased TghuTNF and WT littermate control mice were determined by deep sequencing of small RNAs and the arthritic profile was established by pairwise comparisons of the two groups. qRT-PCR analysis was utilised for profile validation purposes and miR quantitation in patient SFs. Dysregulated miR target genes and pathways were predicted via bioinformatic algorithms. Overall design: Synovial Fibroblasts isolated from TghuTNF mice (2 x biological replicates) and control WT littermate mice (2 x biological replicates)
Identification of microRNA-221/222 and microRNA-323-3p association with rheumatoid arthritis via predictions using the human tumour necrosis factor transgenic mouse model.
Specimen part, Cell line, Subject
View SamplesThe aim of the study is to evaluate oxygen regulated gene expression in human peripheral blood lymphocytes using microarray analysis.
Variations within oxygen-regulated gene expression in humans.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNA-125a is over-expressed in insulin target tissues in a spontaneous rat model of Type 2 Diabetes.
Sex, Age, Specimen part
View SamplesType 2 diabetes (T2D) is characterized by hyperglycaemia and defects in insulin secretion and action at target tissues. Using the Illumina RatRef-12 v1.0 array, gene expression was assessed in two insulin-target tissues (liver and adipose tissue) from seven-month-old spontaneously diabetic (Goto-Kakizaki [GK]) and non-diabetic (Brown-Norway [BN]) rats. This study was performed in parallel with miRNA expression profiling of the same rats.
MicroRNA-125a is over-expressed in insulin target tissues in a spontaneous rat model of Type 2 Diabetes.
Sex, Age, Specimen part
View Samples