Genome-wide mapping of Hif-1α binding sites in zebrafish
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ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE70886 | GEO | 2016/03/22
SECONDARY ACCESSION(S): PRJNA289762
REPOSITORIES: GEO
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Project description:BackgroundHypoxia Inducible Factor (HIF) regulates a cascade of transcriptional events in response to decreased oxygenation, acting from the cellular to the physiological level. This response is evolutionarily conserved, allowing the use of zebrafish (Danio rerio) as a model for studying the hypoxic response. Activation of the hypoxic response can be achieved in zebrafish by homozygous null mutation of the von Hippel-Lindau (vhl) tumour suppressor gene. Previous work from our lab has focused on the phenotypic characterisation of this mutant, establishing the links between vhl mutation, the hypoxic response and cancer. To further develop fish as a model for studying hypoxic signalling, we examine the transcriptional profile of the vhl mutant with respect to Hif-1α. As our approach uses embryos consisting of many cell types, it has the potential to uncover additional HIF regulated genes that have escaped detection in analogous mammalian cell culture studies.ResultsWe performed high-density oligonucleotide microarray analysis of the gene expression changes in von Hippel-Lindau mutant zebrafish, which identified up-regulation of well-known hypoxia response genes and down-regulation of genes primarily involved in lipid processing. To identify the dependency of these transcriptional changes on HIF, we undertook Chromatin Immunoprecipitation linked next generation sequencing (ChIP-seq) for the transcription factor Hypoxia Inducible Factor 1α (HIF-1α). We identified HIF-1α binding sites across the genome, with binding sites showing enrichment for an RCGTG motif, showing conservation with the mammalian hypoxia response element.ConclusionsTranscriptome analysis of vhl mutant embryos detected activation of key hypoxia response genes seen in human cell models of hypoxia, but also suppression of many genes primarily involved in lipid processing. ChIP-seq analysis of Hif-1α binding sites unveiled an unprecedented number of loci, with a high proportion containing a canonical hypoxia response element. Whether these sites are functional remains unknown, nevertheless their frequent location near transcriptional start sites suggests functionality, and will allow for investigation into the potential hypoxic regulation of genes in their vicinity. We expect that our data will be an excellent starting point for analysis of both fish and mammalian gene regulation by HIF.
| S-EPMC4642629 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2016-03-22 | E-GEOD-70886 | biostudies-arrayexpress
Project description:Analysis of gene expression changes in the von Hippel Lindau when mutant compared to wild-type at 4dpf using a whole genome microarray expression profiling. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. We performed single-colour microarrays to identify the gene expression changes which underpin the hypoxic phenotype. We used 3 biological replicates from both mutant and control, followed by analysis using Limma to identify significant gene expression changes. This work, together with ChIP-seq data for the Hif-1α in von Hippel Lindau mutants, should allow for the Hif-1α dependency of these gene expression changes to be assessed.
2016-03-22 | GSE70885 | GEO
Project description:Analysis of the binding sites of Hif-1α in both wild-type and von Hippel Lindau mutant zebrafish lines at 4dpf by ChIP linked next generation sequencing. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. Results show the extent of Hif-1α binding to the genome, and provide a basis for analysis of the transcriptional response to genetically induced hypoxia in zebrafish.
2016-03-22 | GSE70727 | GEO
Project description:Genome-wide mapping of Hif-1α binding sites in zebrafish
| PRJNA289762 | ENA
Project description:Hypoxia-inducible factor (HIF) regulates the major transcriptional cascade central to the response of all mammalian cells to alterations in oxygen tension. Expression arrays indicate that many hundreds of genes are regulated by this pathway, controlling diverse processes that in turn orchestrate both oxygen delivery and utilization. However, the extent to which HIF exerts direct versus indirect control over gene expression together with the factors dictating the range of HIF-regulated genes remains unclear. Using chromatin immunoprecipitation linked to high throughput sequencing, we identify HIF-binding sites across the genome, independently of gene architecture. Using gene set enrichment analysis, we demonstrate robust associations with the regulation of gene expression by HIF, indicating that these sites operate over long genomic intervals. Analysis of HIF-binding motifs demonstrates sequence preferences outside of the core RCGTG-binding motif but does not reveal any additional absolute sequence requirements. Across the entire genome, only a small proportion of these potential binding sites are bound by HIF, although occupancy of potential sites was enhanced approximately 20-fold at normoxic DNAse1 hypersensitivity sites (irrespective of distance from promoters), suggesting that epigenetic regulation of chromatin may have an important role in defining the response to hypoxia.
| S-EPMC3374576 | biostudies-literature
Project description:Analysis of gene expression changes in the von Hippel Lindau when mutant compared to wild-type at 4dpf using a whole genome microarray expression profiling. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. We performed single-colour microarrays to identify the gene expression changes which underpin the hypoxic phenotype. We used 3 biological replicates from both mutant and control, followed by analysis using Limma to identify significant gene expression changes. This work, together with ChIP-seq data for the Hif-1α in von Hippel Lindau mutants, should allow for the Hif-1α dependency of these gene expression changes to be assessed. The changes in gene expression between von Hippel Lindau mutants and wild-type controls was measured at 4 days post fertilisation. For both wild-type and mutant, 3 biological replicates, each of 30 embryos were used.
2016-03-22 | E-GEOD-70885 | biostudies-arrayexpress
Project description:Analysis of the binding sites of Hif-1α in both wild-type and von Hippel Lindau mutant zebrafish lines at 4dpf by ChIP linked next generation sequencing. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. Results show the extent of Hif-1α binding to the genome, and provide a basis for analysis of the transcriptional response to genetically induced hypoxia in zebrafish. Analysis of the DNA binding sites of Hif-1α in both wild-type and von Hippel Lindau mutant zebrafish lines at 4dpf. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. Results show the extent of Hif-1α binding to the genome, and provide a basis for analysis of the dependency of the transcriptional response on Hif-1α in conditions of genetically induced hypoxia in zebrafish.
2016-03-22 | E-GEOD-70727 | biostudies-arrayexpress
Project description:UnlabelledWe identified 531 and 616 putative HIF-1α target sites by ChIP-Seq in the cancerous cell line DLD-1 and the non-cancerous cell line TIG-3, respectively. We also examined the positions and expression levels of transcriptional start sites (TSSs) in these cell lines using our TSS-Seq method. We observed that 121 and 48 genes in DLD-1 and TIG-3 cells, respectively, had HIF-1α binding sites in proximal regions of the previously reported TSSs that were up-regulated at the transcriptional level. In addition, 193 and 123 of the HIF-1α target sites, respectively, were located in proximal regions of previously uncharacterized TSSs, namely, TSSs of putative alternative promoters of protein-coding genes or promoters of putative non-protein-coding transcripts. The hypoxic response of DLD-1 cells was more significant than that of TIG-3 cells with respect to both the number of target sites and the degree of induced changes in transcript expression. The Nucleosome-Seq and ChIP-Seq analyses of histone modifications revealed that the chromatin formed an open structure in regions surrounding the HIF-1α binding sites, but this event occurred prior to the actual binding of HIF-1α. Different cellular histories may be encoded by chromatin structures and determine the activation of specific genes in response to hypoxic shock.Electronic supplementary materialThe online version of this article (doi:10.1007/s11568-011-9150-9) contains supplementary material, which is available to authorized users.
| S-EPMC3051044 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2021-06-10 | GSE176426 | GEO