This SuperSeries is composed of the SubSeries listed below.
Complex Interdependence Regulates Heterotypic Transcription Factor Distribution and Coordinates Cardiogenesis.
Specimen part
View SamplesIn the developing heart, heterotypic transcription factors (TFs) interactions, such as between the T-box TF TBX5 and the homeodomain TF NKX2-5 have been proposed as a mechanism for human congenital heart disease. In order to study the role of each TF during heart formation, embryonic stem (ES) cell-derived embryos were generated from KO ES cells for Tbx5, Nkx2-5 or both TFs.
Complex Interdependence Regulates Heterotypic Transcription Factor Distribution and Coordinates Cardiogenesis.
Specimen part
View SamplesCryopreservation consists of preserving living cells or tissues at <-100C and has many applications in, for instance, stem cell and organ banking. Cryoprotectant agents, like ethylene glycol, are required for successful cryopreservation but have toxic side effects due to largely unknown mechanisms. In this work, we studied the toxicity of ethylene glycol in Human Umbilical Vein Endothelial Cells (HUVECs). Exposing cells to 60% ethylene glycol for two hours at 4C resulted in a slight decrease in cell growth, suggesting a modest toxicity of ethylene glycol and that HUVECs do not exhibit particular sensitivity to it. Gene expression analysis with whole genome micro-arrays revealed signatures indicative of a generalized stress response at 24 hours after stress and recovery at 72 hours, involving signaling pathways, glycoproteins, and genes involved in extracellular and transmembrane functions. These results reveal a new paradigm and signatures for future experiments in elucidating the toxicity effects of ethylene glycol in vascular endothelial cells.
Insights on cryoprotectant toxicity from gene expression profiling of endothelial cells exposed to ethylene glycol.
Specimen part, Treatment
View SamplesInterferons have been ascribed to mediate antitumor effects. IRF-1 is a major target gene of interferons. It inhibits cell proliferation and oncogenic transformation. Here we show that 60% of all mRNAs deregulated by oncogenic transformation mediated by c-myc and H-ras are reverted to the expression levels of non-transformed cells by IRF-1. These include cell cycle regulating genes. Activation of IRF-1 decreases cyclin D1 expression and CDK4 kinase activity concomitant with dephosphorylation of pRb. These effects of IRF-1 are mediated by inhibition of the MEK-ERK pathway and a transcriptional repression of cyclin D1. IRF-1 mediated effects on cell cycle progression were found to be overridden by ectopic expression of cyclin D1. Ablation of cyclin D1 by RNA interference experiments prevents transformation and tumor growth in nude mice. The data demonstrate that cyclin D1 is a key target for IRF-1 mediated tumor suppressive effects.
Tumor suppression by IFN regulatory factor-1 is mediated by transcriptional down-regulation of cyclin D1.
Specimen part
View SamplesMutation of MTF in Arabidopsis increases Agrobacterium-mediated transformation susceptibility. Being a putative transcription factor, different genes controlling transformation may be regulated by MTF.
Cytokinins secreted by Agrobacterium promote transformation by repressing a plant myb transcription factor.
Specimen part
View SamplesHuman naïve pluripotent stem cells (PSC) share features with pre-implantation epiblast. They thus provide an unmatched opportunity for characterising the developmental programme of pluripotency in Homo sapiens. Here we confirm that naïve PSC do not respond directly to germ layer induction, but must first acquire competence. Capacitation for multi-lineage differentiation occurs without exogenous growth factor stimulation and is facilitated by inhibition of Wnt signalling. Whole transcriptome profiling during this formative transition highlights dynamic changes in gene expression, affecting many cellular properties, including metabolism and epithelialisation. Notably, naïve pluripotency factors are exchanged for post-implantation factors, but competent cells remain devoid of lineage primed transcription. The gradual pace of transition for human naïve PSC is consistent with the timespan of primate development from blastocyst to gastrulation. Transcriptome trajectory during in vitro capacitation of human naïve cells tracks the progression of epiblast during embryogenesis in Macaca fascicularis, but shows greater divergence from mouse development. Thus the formative transition of naïve PSC in a simple culture system may recapitulate essential and specific features of pluripotency dynamics during an inaccessible period of human embryogenesis. Overall design: 2 lines of human naïve pluripotent stem cells (embryo-derived HNES1 and chemically reset cR-H9-EOS) were cultured in N2B27 and 2uM XAV939 for 10 days. After that the cells were split into two conditions: N2B27 + 2uM XAV939 + 3ng/ml Activin A + 10ng/ml FGF2 (XAF), or E8 medium, for extended maintenance. The experiment was performed in biological triplicates for each cell line. RNAseq was performed with the cells on day 0, 1, 2, 3, 7, 10, when the cells were cultured in XAV939; and one time point after transfer to maintenance conditions, at not less than 22 days of culture from the start of the experiment. Conventional hES cell line H9-EOS, which was a parental line for the chemically reset cR-H9-EOS was used as a control (in biological triplicate).
Capacitation of human naïve pluripotent stem cells for multi-lineage differentiation.
Specimen part, Cell line, Subject
View SamplesWe compared the gene expression of A549 cells following 24 and 48 hours of treatment with a no-observed-effect level dose of cisplatin. The objective of the study is to identify genes that are differentially expressed in response to sub-lethal doses of cisplatin. This study helps identify not only treatment responses but also changes in gene expression that may confer cytoprotective mechanisms that allow these cells to survive treatment and to develop treatment resistance.
Combined Use of Gene Expression Modeling and siRNA Screening Identifies Genes and Pathways Which Enhance the Activity of Cisplatin When Added at No Effect Levels to Non-Small Cell Lung Cancer Cells In Vitro.
Cell line, Treatment, Time
View SamplesSubstantial effort is currently devoted to identifying cancer-associated alterations using genomics. Here, we show that standard blood collection procedures rapidly change the transcriptional and post-transcriptional landscapes of hematopoietic cells, resulting in biased activation of specific biological pathways, up-regulation of pseudogenes, antisense RNAs, and unannotated coding isoforms, and RNA surveillance inhibition. Affected genes include common mutational targets and thousands of other genes participating in processes such as chromatin modification, RNA splicing, T and B cell activation, and NF-?B signaling. The majority of published leukemic transcriptomes exhibit signals of this incubation-induced dysregulation, explaining up to 40% of differences in gene expression and alternative splicing between leukemias and reference normal transcriptomes. The effects of sample processing are particularly evident in pan-cancer analyses. We provide biomarkers that detect prolonged incubation of individual samples, and show that keeping blood on ice markedly reduces changes to the transcriptome. In addition to highlighting the potentially confounding effects of technical artifacts in cancer genomics data, our study emphasizes the need to survey the diversity of normal as well as neoplastic cells when characterizing tumors. This study is complemented by GSE61410: transcriptomic profiling of bone marrow cells from healthy individuals. Overall design: Peripheral blood mononuclear cells (PBMCs) were isolated from four healthy individuals, following an ex vivo incubation of variable length at either room temperature or on ice. RNA transcriptomes were measured using the Illumina HiSeq.
Sample processing obscures cancer-specific alterations in leukemic transcriptomes.
No sample metadata fields
View SamplesThe recruitment of mesenchymal stem cells in order to reconstruct damaged cartilage of osteoarthritis joints is a challenging tissue engineering task. Vision towards this goal is blurred by a lack of knowledge about the underlying differences between chondrocytes and MSC during the chondrogenic cultivation process. The aim of this study was to shed light on the differences between chondrocytes and MSC occurring during chondral differentiation through tissue engineering.
Expression pattern differences between osteoarthritic chondrocytes and mesenchymal stem cells during chondrogenic differentiation.
Specimen part
View SamplesThe canonical role of eEF1A is to deliver the aminoacyl tRNA to the ribosome, we have used the yeast model system to investigate further roles for this protein.
Inappropriate expression of the translation elongation factor 1A disrupts genome stability and metabolism.
No sample metadata fields
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