Hypoxia inducible factor (HIF) is the major transcriptional regulator of cellular responses to hypoxia. The two principal HIF-a isoforms, HIF-1a and HIF-2a, are progressively stabilized in response to hypoxia and form heterodimers with HIF-1b to activate a broad range of transcriptional responses. Here we report on the pan-genomic distribution of isoform-specific HIF binding in response to hypoxia of varying severity and duration, and in response to genetic ablation of each HIF-a isoform. Our findings reveal that, despite an identical consensus recognition sequence in DNA, each HIF heterodimer loads progressively at a distinct repertoire of cell-type specific sites across the genome, with little evidence of redistribution under any of the conditions examined. Marked biases towards promoter proximal binding of HIF-1 and promoter distant binding of HIF-2 were observed under all conditions and were consistent in multiple cell type. The findings imply that each HIF isoform has an inherent property that determines its binding distribution across the genome, which might be exploited to therapeutically target the specific transcriptional output of each isoform independently. Overall design: RNA_seq analysis of hypoxic gene regulation in HKC8 and HepG2 cell lines and in RCC4 cell lines stably transfected with wtVHL
Hypoxia drives glucose transporter 3 expression through hypoxia-inducible transcription factor (HIF)-mediated induction of the long noncoding RNA NICI.
Specimen part, Cell line, Subject
View SamplesQuiescent and dividing hemopoietic stem cells (HSC) display marked differences in their ability to move between the peripheral circulation and the bone marrow. Specifically, long-term engraftment potential predominantly resides in the quiescent HSC subfraction, and G-CSF mobilization results in the preferential accumulation of quiescent HSC in the periphery. In contrast, stem cells from chronic myeloid leukemia (CML) patients display a constitutive presence in the circulation. To understand the molecular basis for this, we have used microarray technology to analyze the transcriptional differences between dividing and quiescent, normal, and CML-derived CD34+ cells.
Transcriptional analysis of quiescent and proliferating CD34+ human hemopoietic cells from normal and chronic myeloid leukemia sources.
Specimen part, Disease, Subject
View SamplesIRAK-4 is an essential component of the signal transduction complex downstream of the IL-1- and Toll-like receptors. Though regarded as the first kinase in the signaling cascade, the role of IRAK-4 kinase activity versus its scaffold function is still controversial. In order to investigate the role of IRAK-4 kinase function in vivo, knock-in mice were generated by replacing the wild type IRAK-4 gene with a mutant gene encoding kinase deficient IRAK-4 protein (IRAK-4 KD). Analysis of bone marrow macrophages obtained from WT and IRAK-4 KD mice with a number of experimental techniques demonstrated that the IRAK-4 KD cells greatly lack responsiveness to stimulation with the Toll-like receptor 4 (TLR4) agonist LPS. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent LPS response genes and revealed that the induction of LPS-responsive mRNAs was largely ablated in IRAK-4 KD cells. In summary, our results suggest that IRAK-4 kinase activity plays a critical role in TLR4-mediated induction of inflammatory responses.
IRAK-4 kinase activity-dependent and -independent regulation of lipopolysaccharide-inducible genes.
No sample metadata fields
View SamplesMicroarray studies revealed that as a first hit, SV40 T/t-antigen causes deregulation of 462 genes in mammary gland cells (ME-cells) of WAP-SVT/t transgenic animals. The majority of deregulated genes are cell-proliferation specific and Rb-E2F dependent, causing ME-cell proliferation and gland hyperplasia but not breast cancer formation. In the breast tumor cells, a further 207 genes are differentially expressed, most of them belonging to the cell communication category. In tissue culture, breast tumor cells frequently switch off WAP-SVT/t transgene expression and regain the morphology and growth characteristics of normal-ME-cells, although the tumor-revertant cells are aneuploid and only 114 genes regain the expression level of normal-ME-cells. The profile of retransformants shows that only 38 deregulated genes appear to be tumor-relevant and that none of them is considered to be a typical breast cancer gene.
Gene expression profiling: cell cycle deregulation and aneuploidy do not cause breast cancer formation in WAP-SVT/t transgenic animals.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Molecular Aging of Human Liver: An Epigenetic/Transcriptomic Signature.
Sex, Age, Specimen part, Disease
View SamplesGene expression profiling of liver biopsies collected from 33 healthy liver donors ranging from 13 to 90 years old. The Affymetrix HG-U133 Plus 2.0 GeneChip platform was used to evaluate gene-expression.
Molecular Aging of Human Liver: An Epigenetic/Transcriptomic Signature.
Sex, Age, Specimen part, Disease
View SamplesBackground: Although TNF inhibitors are used to treat chronic inflammatory diseases, there is little information about how long-term inhibition of TNF affects the homeostatic functions that TNF maintains in the intact CNS. TNF is known to modulate neurogenesis by decreasing cell proliferation, increasing apoptosis of precursor cells, and impairing neuronal differentiation. TNF can also influence the formation of the hippocampus, with long-lasting effects on cognition. Materials and methods: To clarify whether developmental TNF deficiency causes alterations in the naïve CNS, we estimated the number of proliferating cells, microglia, and neurons in the brains of E13.5, P7, and adult TNF +/+ and TNF-/- mice and measured changes in gene and protein expression and monoamine levels in adult TNF+/+ and TNF-/- mice. To evaluate long-term effects of TNF inhibitors, we treated healthy adult C57BL/6 mice with either saline, selective soluble TNF inhibitor XPro1595, or nonselective TNF inhibitor etanercept. We estimated changes in cell number and protein expression after two months of treatment. We assessed the effects of TNF deficiency on cognition by testing adult TNF+/+ and TNF-/- mice and anti-TNF treated mice with behavioral tasks.
TNF deficiency causes alterations in the spatial organization of neurogenic zones and alters the number of microglia and neurons in the cerebral cortex.
Sex, Specimen part
View SamplesAlternative promoters (APs) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic impact of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes, and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, while in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor (ER) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ER coregulators. Finally, genes with differentially regulated promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show in particular that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation, and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in estrogen-regulated genes, demonstrates the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome, as well as their physiopathologic significance in breast cancer.
Estrogen regulation and physiopathologic significance of alternative promoters in breast cancer.
Disease, Disease stage, Cell line, Time
View SamplesIRAK-4 is an essential component of the signal transduction complex downstream of the IL-1- and Toll-like receptors. Though regarded as the first kinase in the signaling cascade, the role of IRAK-4 kinase activity versus its scaffold function is still controversial. In order to investigate the role of IRAK-4 kinase function in vivo, knock-in mice were generated by replacing the wild type IRAK-4 gene with a mutant gene encoding kinase deficient IRAK-4 protein (IRAK-4 KD). Analysis of embryonic fibroblasts and macrophages obtained from IRAK-4 KD mice with a number of experimental techniques demonstrated that they greatly lack responsiveness to stimulation with IL-1b or a Toll-like receptor 7 (TLR7) agonist. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent IL-1b response genes in mouse embryonic fibroblasts and revealed that the induction of IL-1b-responsive mRNAs was largely ablated in IRAK-4 KD cells. In summary, our results suggest that IRAK-4 kinase activity plays a critical role in IL-1R/TLR7-mediated induction of inflammatory responses.
IRAK-4 kinase activity is required for interleukin-1 (IL-1) receptor- and toll-like receptor 7-mediated signaling and gene expression.
No sample metadata fields
View SamplesThis study was designed to compare the global gene expression change induced by the circulating, prodomain bound forms of BMP9 and BMP10 (pro-BMP9 and pro-BMP10) in human pulmonary arterial endothelial cells (PAECs). This is different from many previous studies which used the growth factor domain of BMP9 and/or BMP10.
Molecular basis of ALK1-mediated signalling by BMP9/BMP10 and their prodomain-bound forms.
Sex, Age
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