C/EBPa induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem cells (iPSCs) when co-expressed with Oct4, Sox2, Klf4 and Myc (OSKM). However, how C/EBPa accomplishes these effects is unclear. We now found that transient C/EBPa expression followed by OSKM activation induces a 100 fold increase in iPSC reprogramming efficiency, involving 95% of the cells. During this conversion pluripotency and epithelial-mesenchymal transition genes become dramatically up-regulated and 60% of the cells express Oct4 within 2 days. C/EBPa acts as a pathbreaker since it transiently makes the chromatin of pluripotency genes more accessible to DNase I. It also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated following OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM-induced B cell reprogramming. Since the enzyme is also required for efficient C/EBPa-induced immune cell conversion, our data suggest that Tet2 provides a mechanistic link between iPSC reprogramming and B cell transdifferentiation. The rapid iPS reprogramming approach described should help to fully elucidate the process and has potential clinical applications. Overall design: Change in gene expression, comparing primary B-cells treated with estradiol for 18h to induce C/EBPa to untreated cells.
Time-resolved gene expression profiling during reprogramming of C/EBPα-pulsed B cells into iPS cells.
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View SamplesThe homeobox containing gene Arx is expressed during ventral telencephalon development and it is required for correct GABAergic interneuron tangential migration from the ganglionic eminences to the olfactory bulbs, cerebral cortex and striatum. Its human ortholog is associated with a variety of neurological clinical manifestations whose syntoms are compatible with a loss of cortical interneurons and altered basal ganglia related-activities in humans. Herein, we reported the identification by global expression profiling of a group of genes whose expression is consistently altered in Arx mutant ganglionic eminences. Following analysis revealed the striking ectopic expression in the ganglionic eminences of a number of genes normally not, or only marginally, expressed in the ventral telencephalon. Among them, we functionally analyzed Ebf3, whose ectopic expression in ventral telencephalon is preventingneuronal tangential migration. Further, we showed that Arx is sufficient to repress Ebf3 endogenous expression and that its silencing in Arx mutant tissue might marginally rescue tangential cell movements. Together, these data provide an initial analysis of the molecular pathways regulated by Arx and how their networking might regulate those specific cellular processes during telencephalon development strongly altered by loss of Arx.
Arx acts as a regional key selector gene in the ventral telencephalon mainly through its transcriptional repression activity.
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View SamplesMouse Bcell, upon ectopic expression of the transcription factor Cebpa for 18h, can be reprogrammed to iPS with extremely high efficiency. To understand the molecular control of this phenomena we performed multiple high throughtput functionnal genomic analysis. Overall design: Transcriptomic by RNAseqencing (polyA+, non stranded) in Bcell, Bcell+Cebpa18h, Bcell+Cebpa18h+OKSM1d, Bcell+Cebpa18h+OKSM2d, ES cells
C/EBPα creates elite cells for iPSC reprogramming by upregulating Klf4 and increasing the levels of Lsd1 and Brd4.
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View SamplesHere we analyse single cell transcriptome profiles of EZH2-deficient human embroynic stem cells Overall design: Single cell transcriptome (mRNA-Seq) from Ezh2-/- (Null) and EZH2+/+ (WT) human ESC
Deletion of the Polycomb-Group Protein EZH2 Leads to Compromised Self-Renewal and Differentiation Defects in Human Embryonic Stem Cells.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Characterization of aldehyde dehydrogenase 1 high ovarian cancer cells: Towards targeted stem cell therapy.
Specimen part, Cell line
View SamplesObjective: The cancer stem cell (CSC) paradigm hypothesizes that successful clinical eradication of CSCs may lead to durable remission for patients with ovarian cancer. Despite mounting evidence in support of ovarian CSCs, their phenotype and clinical relevance remain unclear. We and others have found high aldehyde dehydrogenase 1 (ALDHhigh) expression in a variety of normal and malignant stem cells, and sought to better characterize ALDHhigh cells in ovarian cancer. Methods: We compared ALDHhigh to ALDHlow cells in two ovarian cancer models representing distinct subtypes: FNAR-C1 cells, derived from a spontaneous rat endometrioid carcinoma, and the human SKOV3 cell line (described as both serous and clear cell subtypes). We assessed these populations for stem cell features then analyzed expression by microarray and qPCR. Results: ALDHhigh cells displayed CSC properties, including: smaller size, quiescence, regenerating the phenotypic diversity of the cell lines in vitro, lack of contact inhibition, nonadherent growth, multi-drug resistance, and in vivo tumorigenicity. Microarray and qPCR analysis of the expression of markers reported by others to enrich for ovarian CSCs revealed that ALDHhigh cells of both models showed downregulation of CD24, but inconsistent expression of CD44, KIT and CD133. However, the following drugable targets were consistently expressed in the ALDHhigh cells from both models: mTOR signaling, her-2/neu, CD47 and FGF18 / FGFR3. Conclusions: Based on functional characterization, ALDHhigh ovarian cancer cells represent an ovarian CSC population. Differential gene expression identified drugable targets that have the potential for therapeutic efficacy against ovarian CSCs from multiple subtypes.
Characterization of aldehyde dehydrogenase 1 high ovarian cancer cells: Towards targeted stem cell therapy.
Specimen part, Cell line
View SamplesDetailed information about stage-specific changes in gene expression is crucial for understanding the gene regulatory networks underlying development and the various signal transduction pathways contributing to morphogenesis. Here, we describe the global gene expression dynamics during early murine limb development, when cartilage, tendons, muscle, joints, vasculature, and nerves are specified and the musculoskeletal system of the limbs is established. We used whole-genome microarrays to identify genes with differential expression at 5 stages of limb development (E9.5 to 13.5), during fore-limb and hind-limb patterning. We found that the onset of limb formation is characterized by an up-regulation of transcription factors, which is followed by a massive activation of genes during E10.5 and E11.5 which tampers off at later time points. Among 3520 genes identified as significantly up-regulated in the limb, we find ~30% to be novel, dramatically expanding the repertoire of candidate genes likely to function in the limb. Hierarchical and stage-specific clustering identified expression profiles that correlate with functional programs during limb development and are likely to provide new insights into specific tissue patterning processes. Here we provide for the first time, a comprehensve analysis of developmentally regulated genes during murine limb development, and provide some novel insights into the expression dynamics governing limb morphogenesis.
Global gene expression analysis of murine limb development.
Specimen part
View SamplesPurpose: The purpose of this study was to develop a framework for analyzing RPE expression profiles from zebrafish eye mutants. Methods: The fish model we used was smarca4 (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4), a retinal dystrophic mutant that the retinal phenotype and expression profiles were previously characterized. Histological and Affymetrix GeneChip analyses were conducted to define the RPE defects and underlying differential expression respectively. Results: Histological analysis indicates that smarca4 RPE was formed but its differentiation was abnormal. In particular, ultra-structural analysis of smarca4 RPE by transmission electron microscopy showed a number of defects in melanogenesis, suggesting that the cytoskeletal dynamics was impaired. To compare the expression profile of normal wild-type (WT) and smarca4 RPE, their retinas and RPE-attached retinas were microdissected and the gene expression values of these tissues measured by Affymetrix GeneChip analysis. The RPE expression values were then estimated from these samples using an approach previously established by us. A factorial analysis was conducted using the expression values of RPE, retinal as well as the whole-embryo samples. Specific rules (contrasts) were built using the coefficients of the resulting fitted model to select for three groups of genes: 1) Smarca4-regulated RPE genes, 2) Smarca4-regulated retinal genes, and 3) Smarca4-regulated RPE genes that are not differentially expressed in the retina. The latter group consists of 39 genes that are highly related to cytoskeletal dynamics, melanogenesis, paracrine and intracellular signal transduction. Conclusions: Our analytical framework can potentially identify genes in zebrafish mutants that both retina and RPE are affected by the underlying mutation.
Expression profiling of the RPE in zebrafish smarca4 mutant revealed altered signals that potentially affect RPE and retinal differentiation.
Specimen part
View SamplesArabidopsis is a non-host to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh), effectively hindering Bgh ingress to the epidermal cells by deposition of callosic papillae formations, i.e. penetration resistance. To better understand the transcriptional changes in Arabidopsis towards Bgh, we compared un-inoculated and inoculated wild-type Arabidopsis samples, with those an ATAF1 mutant allele, compromised in penetration resistance. The experiment included sampling of 8 rosettes for each replicate sample from 6-weeks old plants, 12 hrs after inoculation. A total of 12 biolocigal replicates were sampled with three replicates from each of the four blocks (Wild-type, ataf1-1, Bgh, control). ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Michael Krogh Jensen. The equivalent experiment is AT31 at PLEXdb.]
Transcriptional regulation by an NAC (NAM-ATAF1,2-CUC2) transcription factor attenuates ABA signalling for efficient basal defence towards Blumeria graminis f. sp. hordei in Arabidopsis.
No sample metadata fields
View SamplesWe are using the ACI rat model of 17beta-estradiol induced mammary cancer to define the mechanisms through which estrogens contribute to breast cancer development; identify and functionally characterize the genetic variants that determine susceptibility; and define the hormone-gene-environment interactions that influence development of mammary cancer in this physiologically relevant rat model. Female ACI rats are uniquely susceptible to development of mammary cancer when treated continuously with physiologic levels of 17beta-estradiol. Induction of mammary cancer in female ACI rats occurs through a mechanism that is largely dependent upon estrogen receptor-alpha. Interval mapping analyses of progeny generated in intercrosses between susceptible ACI rats and resistant Brown Norway (BN) rats revealed seven quantitative trait loci (QTL), designated Emca3 (Estrogen-induced mammary cancer) through Emca9, each of which harbors one or more genetic determinants of mammary cancer susceptibility. Genes that reside within Emca8 on RNO5 and were differentially expressed between 17beta-estradiol treated ACI and ACI.BN-Emca8 congenic rats were identified as Emca8 candidates.
Mapping of three genetic determinants of susceptibility to estrogen-induced mammary cancer within the Emca8 locus on rat chromosome 5.
Sex, Age, Specimen part
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