This 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 SamplesDespite RNAi-based screens to uncover genes controlling embryonic stem cell (ESC) identity, the pluripotency network remains poorly characterized, as does the precise molecular mechanisms underlying the balance between self-renewal and differentiation. Here we carried out a systematic meta-analysis of published gene expression data to rank-order genes based on their likelihood of regulating ESC identity. Not only did our analysis correctly rank known pluripotency-associated genes atop the list, but it also helped unearth many novel determinants of ESC identity including several components of functionally distinct complexes, as determined using RNAi. We focus on our top-hit Nucleolin, and characterize its mechanistic role in the maintenance of ESC homeostasis by shielding from differentiation-inducing redox imbalance-induced oxidative stress. Notably, we identify a conceptually novel mechanism involving a Nucleolin-dependent bistable switch regulating the homeostatic balance between self-renewal and differentiation in ESCs. Our gene ranks represent a rich and valuable resource for uncovering novel ESC regulators.
Integrative framework for identification of key cell identity genes uncovers determinants of ES cell identity and homeostasis.
Cell line
View SamplesWith a model mimicking GBM tumor cell dispersal, transcriptome changes between core (immotile) and dispersive (motile) cells were analyzed. Many genes are differentially expressed between these populations. This study focused on the genes that are significantly upregulated in dispersive cells. Besides gene sets related with the cell cycle and cell survival, epithelial to mesenchymal transition gene set is upregulated in dispersive cells. In this gene set, this study identified SERPINE1 gene as an important regulator of GBM cell dispersal. Overall design: Examination of core and dispersive populations' transcriptome during U373 cell spheroid dispersal. 2 sets of samples were prepared each for core and dispersive cells.
Identification of <i>SERPINE1</i> as a Regulator of Glioblastoma Cell Dispersal with Transcriptome Profiling.
Cell line, Subject
View SamplesTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anti-cancer protein that can specifically kill tumor cells while sparing healthy ones. Emerging evidences suggest that TRAIL resistance in cancers is associated with aberrant expression of the key components of the apoptotic program. However, how these components are regulated at the epigenetic level is not understood. In this study, we aimed to identify novel epigenetic mechanisms regulating TRAIL response in Glioblastoma Multiforme (GBM) by a short-hairpin RNA (shRNA) screen. We employed an shRNA-mediated loss of function approach to interrogate the role of 48 genes in DNA and histone modification pathways. From this we identified KDM2B, an H3K36-specific demethylase, as a novel regulator of TRAIL response. Accordingly, silencing of KDM2B significantly enhanced TRAIL sensitivity, the activation of Caspase-8, Caspase-3, Caspase-7, and cleavage of PARP. KDM2B knockdown also accelerated the apoptosis process, as revealed by live cell imaging experiments. Moreover, simultaneous knockdown of the methyltransferases responsible for generating the histone marks removed by KDM2B significantly recovered the cell death phenotype observed with KDM2B inhibition. To decipher the downstream molecular pathways regulated by KDM2B, levels of apoptosis-related genes were examined by RNA-sequencing and quantitative PCR upon KDM2B loss, which revealed de-repression of pro-apoptotic genes HRK, caspase-7, and DR4 and repression of anti-apoptotic gene Mcl-1. The apoptosis phenotype was dependent on HRK upregulation, as HRK knockdown significantly abrogated the sensitization. In vivo, KDM2B-silenced tumors exhibited slower growth and reduced angiogenic capacity compared to controls. Taken together, our findings suggest a novel mechanism regulating apoptotic response, where the key apoptosis components are under epigenetic control of KDM2B in GBM cells. Overall design: mRNA profiles of U87MG GBM cells transduced either by control shRNA or shRNA targeting KDM2B were generated by RNA-seq (Illumina HiSeq 2500). 2 biological replicates of shControl and shKDM2B total RNAs were barcoded individually and deep sequenced as 3 technical replicates each in 3 lanes.
KDM2B, an H3K36-specific demethylase, regulates apoptotic response of GBM cells to TRAIL.
Specimen part, Subject
View SamplesThe transition between morula and blastocyst stage during preimplantation development represents the first differentiation event of embryogenesis. Morula cells undergo the first cellular specialization and produce two well-defined populations of cells, the trophoblast and the inner cell mass (ICM). Embryonic stem cells (ESCs) with unlimited self-renewal capacity are believed to represent the in vitro counterpart of the ICM. Both mouse and rat ESCs can be derived from the ICM cells, but their in vitro stability differs. In this study we performed a microarray analysis in which we compared the transcriptome of mouse and rat morula, blastocyst, and ICM. This cross-species comparison represents a good model for understanding the differences in derivation and cultivation of ESCs observed in the two species. In order to identify alternative regulation of important molecular mechanisms the investigation of differential gene expression between the two species was extended at the level of signaling pathways, gene families, and single selected genes of interest. Some of the genes differentially expressed between the two species are already known to be important factors in the maintenance of pluripotency in ESCs, like for example Sox2 or Stat3, or play a role in reprogramming somatic cells to pluripotency like c-Myc, Klf4 and p53 and therefore represent interesting candidates to further analyze in vitro in the rat ESCs. This is the first study investigating the gene expression changes during the transition from morula to blastocyst in the rat preimplantation development. Our data show that in the pluripotent pool of cells of the rat and mouse preimplantation embryo substantial differential regulation of genes is present, which might explain the difficulties observed for the derivation and culture of rat ESCs using mouse conditions
Cross-species genome wide expression analysis during pluripotent cell determination in mouse and rat preimplantation embryos.
Sex, Age, Specimen part
View SamplesTo screen for candidate genes that may contribute to the pathogenesis of ATS
GLUT10 deficiency leads to oxidative stress and non-canonical αvβ3 integrin-mediated TGFβ signalling associated with extracellular matrix disarray in arterial tortuosity syndrome skin fibroblasts.
Disease
View Samplesgene expression database and algorithm to define cell expression modules
Identifying gene expression modules that define human cell fates.
Specimen part
View SamplesOsteochondrosis disorder is characterized by a failure of endochondral ossification of the articular-epiphyseal cartilage and the physeal growth cartilage. The number and identity of relevant genes are unknown.
Gene expression profiling of articular cartilage reveals functional pathways and networks of candidate genes for osteochondrosis in pigs.
Specimen part
View SamplesWe exposed wild-type Vibrio cholerae E7496, multiple Vibrio cholerae virulence factor deleted genes with intact hemolysin A gene [CVD109] and without hemolysin A gene [CVD110] in E7946, and E.coli OP50 to wild-type C.elegans N2 for 18 hours. We used microarrays to detail the global gene expression and identified distinct classes of up-regulated and down-regulated genes during this process.
Genomic analysis of immune response against Vibrio cholerae hemolysin in Caenorhabditis elegans.
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