Induced pluripotent stem (iPS) cell reprogramming is a gradual epigenetic process that reactivates the pluripotent transcriptional network by erasing and establishing heterochromatin marks. Here, we characterize the physical structure of heterochromatin domains in full and partial mouse iPS cells by correlative Electron Spectroscopic Imaging (ESI). In somatic and partial iPS cells, constitutive heterochromatin marked by H3K9me3 is highly compartmentalized into chromocenter structures of densely packed 10 nm chromatin fibers. In contrast, chromocenter boundaries are poorly defined in pluripotent ES and full iPS cells, and are characterized by unusually dispersed 10 nm heterochromatin fibers in high Nanog-expressing cells, including pluripotent cells of the mouse blastocyst prior to differentiation. This heterochromatin reorganization accompanies retroviral silencing during conversion of partial iPS cells by Mek/Gsk3 2i inhibitor treatment. Thus, constitutive heterochromatin reorganization serves as a novel biomarker with retroviral silencing for identifying iPS cells in the very late stages of reprogramming.
Constitutive heterochromatin reorganization during somatic cell reprogramming.
Specimen part, Cell line
View SamplesWe recently described TRIM8, a nuclear E3 ubiquitin ligase, whose expression inversely correlates with glioma grade. TRIM8 restoration suppresses cell growth and induces a significant reduction of clonogenic potential in both U87MG glioblastoma and patients' primary glioma cell lines. Since E3 ubiquitin ligase proteins regulate carcinogenesis through the timely control of many cellular processes such as DNA damage response, metabolism, transcription, and apoptosis, we reasoned that TRIM8 activity might impact on cell transcriptome patterns, thereby promoting cancer development and progression. Therefore, we profiled the whole transcriptome of normal embryonic neural stem cells (eNSC) infected with a retrovirus expressing FLAG-Trim8 by using RNA-Seq. RNA-Seq revealed 1365 differentially expressed transcripts of 912 genes. 723 of them (corresponding to 648 RefSeq genes) differed significantly of at least 1.5 folds (192 upregulated transcripts of 178 genes and 531 downregulated transcripts of 470 genes). 80 genes, among all differentially expressed genes, resulted to significantly enrich 18 pathways by IPA analysis. 53% of these genes (43 out of 80 genes) are related to cell-morphology, cell death and survival, with a preponderantly representation of signaling pathways related to neurotransmission and to CNS, including axonal guidance, GABA Receptor, ephrin B, synaptic long-term potentiation/depression, and glutamate receptor. Specifically, our results substantiate the role of TRIM8 in the brain functions through the dysregulation of genes involved in different pathways, including JAK-STAT. Finally, we provided additional evidence about the existence of a functional interactive crosstalk between TRIM8 and STAT3 with possible implications in the development and progression of glioma. Overall design: Profiling the transcriptome of TRIM8-expressing primary mouse embryonal neural stem cells using RNA-Seq
TRIM8-driven transcriptomic profile of neural stem cells identified glioma-related nodal genes and pathways.
Specimen part, Subject
View SamplesEmbryo from 6xbcd mother shows expansion of prospective head region. In this embryo, excessive cell death can be observed. This array expreriment is for identifying differentially expressed genes in the 2xbcd and 6xbcd conditions at stage 12-13
A novel cell death gene acts to repair patterning defects in Drosophila melanogaster.
Specimen part
View SamplesPrevious reports have defined three subsets of mouse NK cells on the basis of the expression of CD27 and CD11b. The developmental relationship between these subsets was unclear. To address this issue, we evaluated the overall proximity between mouse NK cell subsets defined by CD27 and CD11b expression using pangenomic gene expression profiling. The results suggest that CD27+CD11b-, CD27+CD11b+ and CD27-CD11b+ correspond to three different intermediates stages of NK cell development.
Maturation of mouse NK cells is a 4-stage developmental program.
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View SamplesMaize transgenic event MON810, grown and commercialised worldwide, is the only cultivated GM event in EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic Tietar were studied in different growing conditions, to assess their behaviour in response to drought. Profiling gene expression in water deficit regimes and in generalised water stress showed an up-regulation of different stress- responsive genes. A greater number of differentially expressed genes was observed in Tietar rather than in DKC6575, with genes belonging to transcription factor families and genes encoding HSPs, LEAs and detoxification enzymes. Since these genes have been from literature, indicated as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient water stress response. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding for the delta-endotoxin insecticidal protein) in water limiting conditions. In all the experiments the CryIAb transcript was not influenced by water stress, but expressed at a constant level. This suggests that though a different pattern of sensitivity to stress, the transgenic variety maintains the same expression level for the transgene.
Comparison of drought stress response and gene expression between a GM maize variety and a near-isogenic non-GM variety.
Specimen part
View SamplesCD34+ fraction of cord blood (CB) cells can be reprogrammed on pronectinF-coated dish in serum free medium using Sendai virus (SeV) vector carrying reprogramming factors OCT3/4, SOX2, KLF4 and c-MYC. human ES cell-like colonies came to merge around 18 days after SeV infection on pronectin-coated dish in human ES cell medium supplemented with bFGF under normoxic culture (20% O2). After passages, dish like-shape colonies were seeded on pronectinF-coated 96 well-plate in a single cell and cultured in N2B27 based medium supplemented with LIF, FK, MAPKi, GSKi in hypoxic culture condition (5% O2) for cloning purpose. Emerged dome shape colonies were collected and cultured in human ES cell medium supplemented with bFGF under normoxic culture (20% O2) again. Dish shape and human ES cell-like colonies derived from single cell were picked up for further appraisal of reprogrammed cells such as expression of pluriotencyrelated molecules. Reprogrammed cells can be maintained for more than 20 passages without differentiation.
Generation of virus-free induced pluripotent stem cell clones on a synthetic matrix via a single cell subcloning in the naïve state.
Specimen part
View SamplesAdministration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extends the lifespan of various model organisms including yeast, flies and worms. In ageing yeast, spermidine treatment triggeres epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), leading to induction of autophagy and thereby suppressing oxidative stress and necrosis. In order to further characterize the effects by spermidine supplementation of aging yeast cultures and to understand how global histone deacetylation affects gene transcription during aging, Affymetrix-based microarray analyses of three day old as well as ten day old cultures with and without administration of spermidine was performed.
Induction of autophagy by spermidine promotes longevity.
Age, Compound, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
CHOP induces activating transcription factor 5 (ATF5) to trigger apoptosis in response to perturbations in protein homeostasis.
Specimen part, Treatment
View SamplesPrimary tumor growth induces host tissue responses that are believed to support and promote tumor progression. Identification of the molecular characteristics of the tumor microenvironment and elucidation of its crosstalk with tumor cells may therefore be crucial for improving our understanding of the processes implicated in cancer progression, identifying potential therapeutic targets, and uncovering stromal gene expression signatures that may predict clinical outcome. A key issue to resolve, therefore, is whether the stromal response to tumor growth is largely a generic phenomenon, irrespective of the tumor type, or whether the response reflects tumor-specific properties. To address similarity or distinction of stromal gene expression changes during cancer progression, oligonucleotide-based Affymetrix microarray technology was used to compare the transcriptomes of laser-microdissected stromal cells derived from invasive human breast and prostate carcinoma. Invasive breast and prostate cancer-associated stroma was observed to display distinct transcriptomes, with a limited number of shared genes. Interestingly, both breast and prostate tumor-specific dysregulated stromal genes were observed to cluster breast and prostate cancer patients, respectively, into two distinct groups with statistically different clinical outcomes. By contrast, a gene signature that was common to the reactive stroma of both tumor types did not have survival predictive value. Univariate Cox analysis identified genes whose expression level was most strongly associated with patient survival. Taken together, these observations suggest that the tumor microenvironment displays distinct features according to the tumor type that provides survival-predictive value.
Identification of prognostic molecular features in the reactive stroma of human breast and prostate cancer.
Specimen part
View SamplesWilliams-Beuren Syndrome (WBS) is a neurodevelopmental disorder caused by aa 1.5 Mb microdeletion on human chromosome 7. Although the molecular cause of the disorder is well-established, little is known about the global impact of the deletion on gene expression. Here we profiled the transcriptomes of fibroblast cell lines from 8 young girls with WBS, and 9 sex- and age-matched control individuals
Using transcription modules to identify expression clusters perturbed in Williams-Beuren syndrome.
Sex, Cell line
View Samples