Hypoxia inducible factor-1a (HIF-1a) is a critical transcription factor for the hypoxic response, angiogenesis, normal hematopoietic stem cell regulation, and cancer development. Importantly, HIF-1a is also a key regulator for immune cell activation. In order to determine whether HIF-1a is sufficient for developing MDS phenotypes, we generated blood specific inducible HIF-1a transgenic mice. Using Vav1-Cre/Rosa26-loxP-Stop-loxP (LSL) rtTA driver, stable HIF-1a can be induced in a doxycycline administration dependent manner. After induction, HIF-1a-induced mice developed thrombocytopenia, leukocytopenia, macrocytic anemia, and multi-lineage dysplasia. We also found activation of both innate and adaptive immunity in HIF-1a- induced mice compared to those from control mice. Taken together, these data suggest that HIF-1a is sufficient to trigger a variety of key MDS features Overall design: Expression profiles of mRNA in HSPCs from constitutively active form of HIF1a protein induced mice and their control mice.
Pathobiological Pseudohypoxia as a Putative Mechanism Underlying Myelodysplastic Syndromes.
Specimen part, Subject
View SamplesThe MLL-PTD mutation is found in patients with MDS and AML, and not in other hematological malignancies. Previously, we showed that Mll-PTD knock-in heterozygous mice (MllPTD/WT mice) present with several MDS-associated features. However, these phenotypes are insufficient to constitute bona fide MDS. MllPTD/WT mice do not generate MDS or AML in primary or transplant recipient mice. This suggests that additional genetic and/or epigenetic defects are necessary for transformation to MDS or AML. In secondary AML and de novo AML, MLL-PTD mutation is significantly associated with mutations in RUNX1 and with the FLT3-ITD mutations. In fact, the combination of MLL-PTD with the FLT3-ITD allele leads to AML in mice. We combined the MLL-PTD with RUNX1 mutant proteins, in order to generate a new mouse model for MDS. We generated MllPTD/WT/Runx1Flox/Flox/Mx1-Cre mice to model loss-of-function RUNX1 mutations. To test the significance of HIF-1a in this model, we also generated MllPTD/WT/Runx1Flox/Flox/Hif-1aFlox/Flox/Mx1-Cre mice and genetically eliminated Hif-1a expression. We analyzed gene expression variations in the HSPCs comparing the MllPTD/WT/Runx1?/? with or without HIF-1a abrogation. Overall design: Expression profiles of mRNA in HSPCs from MLL-PTD/Runx1-KO mice with or without HIF-1a
Pathobiological Pseudohypoxia as a Putative Mechanism Underlying Myelodysplastic Syndromes.
Specimen part, Cell line, Subject
View SamplesThe gastrointestinal (GI) tract can have significant impact on the regulation of the whole body metabolism and may contribute to the development of obesity and diabetes. To systemically elucidate the role of the GI tract in obesity, we performed a transcriptomic analyses in different parts of the GI tract of two obese mouse models: ob/ob and high-fat diet (HFD) fed mice. Compared to their lean controls, both obese mouse groups had significant amount of gene expression changes in the stomach (ob/ob: 959; HFD: 542), much more than the number of changes in the intestine. Despite the difference in genetic background, the two mouse models shared 296 similar gene expression changes in the stomach. Among those genes, some had known associations to obesity, diabetes and insulin resistance. In addition, the gene expression profile strongly suggested an increased gastric acid secretion in both obese mouse models, probably through an activation of the gastrin pathway. In conclusion, our data reveal a previously unknown dominant connection between the stomach and obesity.
Significant obesity-associated gene expression changes occur in the stomach but not intestines in obese mice.
Specimen part
View SamplesExpression profile of human donor lungs that have developed primary graft dysfunction (PGD) after lung transplantation and those that have not.
Expression profiling of human donor lungs to understand primary graft dysfunction after lung transplantation.
No sample metadata fields
View SamplesThe growth in popularity of RNA expression microarrays has been accompanied by concerns about the reliability of the data especially when comparing between different platforms. Here we present an evaluation of the reproducibility of microarray results using two platforms, Affymetrix GeneChips and Illumina BeadArrays. The study design is based on a dilution series of two human tissues (blood and placenta), tested in duplicate on each platform. By a variety of measures the two platforms yielded data of similar quality and properties. The results of a comparison between the platforms indicate very high agreement, particularly for genes which are predicted to be differentially expressed between the two tissues. Agreement was strongly correlated with the level of expression of a gene. Concordance was also improved when probes on the two platforms could be identified as being likely to target the same set of transcripts of a given gene. These results shed light on the causes or failures of agreement across microarray platforms. The set of probes we found to be most highly reproducible can be used by others to help increase confidence in analyses of other data sets using these platforms.
Experimental comparison and cross-validation of the Affymetrix and Illumina gene expression analysis platforms.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Diverse stresses dramatically alter genome-wide p53 binding and transactivation landscape in human cancer cells.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Histone-fold domain protein NF-Y promotes chromatin accessibility for cell type-specific master transcription factors.
Specimen part
View SamplesCell type-specific master transcription factors (MTFs) play vital roles in defining cell identity and function. However, the roles ubiquitous factors play in the specification of cell identity remain underappreciated. Here we show that all three subunits of the ubiquitous heterotrimeric CCAAT-binding NF-Y complex are required for the maintenance of embryonic stem cell (ESC) identity, and establish NF-Y as a novel component of the core pluripotency network. Genome-wide occupancy and transcriptomic analyses in ESCs and neurons reveal that not only does NF-Y regulate genes with housekeeping functions through cell type-invariant promoter-proximal binding, but also genes required for cell identity by binding to cell type-specific enhancers with MTFs. Mechanistically, NF-Y's distinctive DNA-binding mode promotes MTF binding at enhancers by facilitating a permissive chromatin conformation. Our studies unearth a novel function for NF-Y in promoting chromatin accessibility, and suggest that other proteins with analogous structural and DNA-binding properties may function in similar ways.
Histone-fold domain protein NF-Y promotes chromatin accessibility for cell type-specific master transcription factors.
Specimen part
View SamplesThe effects of diverse stresses on promoter selectivity and transcription regulation by the tumor suppressor p53 are poorly understood. We have taken a comprehensive approach to characterizing the human p53 network that includes p53 levels, binding, expression and chromatin changes under diverse stresses. Human osteosarcoma U2OS cells treated with anti-cancer drugs Doxorubicin or Nutlin-3 led to strikingly different p53 gene binding patterns based on ChIP-seq experiments. While two contiguous RRRCWWGYYY decamers is the consensus binding motif, p53 can bind a single decamer and function in vivo. Although the number of sites bound by p53 was 6-times greater for Nutlin-3 than Doxorubicin, expression changes induced by Nutlin-3 were much less dramatic compared to Doxorubicin. Unexpectedly, the solvent DMSO alone induced p53 binding to many sites common to Doxorubicin; however, this binding had no effect on target gene expression. Together, these data imply a two-stage mechanism for p53 transactivation where p53 binding only constitutes the first stage. Furthermore, both p53 binding and transactivation were associated with increased active histone modification H3K4me3. We discovered 149 putative new p53 target genes including several that are relevant to tumor suppression, revealing potential new targets for cancer therapy and expanding our understanding of the p53 regulatory network.
Diverse stresses dramatically alter genome-wide p53 binding and transactivation landscape in human cancer cells.
Specimen part, Cell line
View SamplesBipolar disorder (BD) has an estimated heritability of about 80%. Different pathways and candidate genes may contribute to the pathogenesis of BD, but definite mechanisms are yet unresolved. In a previous study, we identified the single nucleotide polymorphism (SNP) rs4500567, located in the upstream region of Tetraspanin 8 (TSPAN8), to be associated with bipolar disorder (BD).
The regulation of tetraspanin 8 gene expression-A potential new mechanism in the pathogenesis of bipolar disorder.
Cell line
View Samples