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GSE57774
Mus musculus
11 Downloadable Samples
Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
The reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) upon overexpression of OCT4, KLF4, SOX2 and c-MYC (OKSM) provides a powerful system to interrogate basic mechanisms of cell fate change. However, iPSC formation with standard methods is typically protracted and inefficient, resulting in heterogeneous cell populations. We show that exposure of OKSM-expressing cells to both ascorbic acid and a GSK3- inhibitor (AGi) facilitates more synchronous and rapid iPSC formation from several mouse cell types. AGi treatment restored the ability of refractory cell populations to yield iPSC colonies, and it attenuated the activation of developmental regulators commonly observed during the reprogramming process. Moreover, AGi supplementation gave rise to chimera-competent iPSCs after as little as 48 h of OKSM expression. Our results offer a simple modification to the reprogramming protocol, facilitating iPSC induction at unparalleled efficiencies and enabling dissection of the underlying mechanisms in more homogeneous cell populations.
Publication Title
Small molecules facilitate rapid and synchronous iPSC generation.
Sample Metadata Fields
Specimen part, Treatment, Time
View Samples- Mus musculus
- 5 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
Brief expression of pluripotency-associated factors such as Oct4, Klf4, Sox2 and c-Myc (OKSM), in combination with differentiation-inducing signals, has been reported to trigger transdifferentiation of fibroblasts into other cell types. Here we show that OKSM expression in mouse fibroblasts gives rise to both induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs) under conditions previously shown to induce only iNSCs. Fibroblast-derived iNSC colonies silenced retroviral transgenes and reactivated silenced X chromosomes, both hallmarks of pluripotent stem cells. Moreover, lineage tracing with an Oct4-CreER labeling system demonstrated that virtually all iNSC colonies originated from cells transiently expressing Oct4, whereas ablation of Oct4+ cells prevented iNSC formation. Lastly, an alternative transdifferentiation cocktail that lacks Oct4 and was reportedly unable to support induced pluripotency yielded iPSCs and iNSCs carrying the Oct4-CreER-derived lineage label. Together, these data suggest that iNSC generation from fibroblasts using OKSM and other pluripotency-related reprogramming factors requires passage through a transient iPSC state.
Publication Title
Lineage conversion induced by pluripotency factors involves transient passage through an iPSC stage.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
The generation of induced pluripotent stem cells (iPSCs) from differentiated cells following forced expression of Oct4, Klf4, Sox2 and c-Myc (OKSM) is slow and inefficient, suggesting that transcription factors have to overcome somatic barriers that resist cell fate change. Here, we performed an ubiased serial shRNA enrichment screen to identify novel repressors of somatic cell reprogramming into iPSCs. This effort uncovered the sumoylation effector protein Sumo2 as one of the strongest roadblocks to iPSC formation. Depletion of Sumo2 both enhances and accelerates reprogramming, yielding transgene-independent, chimera-competent iPSCs after as little as 36 hours of OKSM expression. We further show that the Sumo2 pathway acts independently of exogenous c-Myc expression and in parallel with small molecule enhancers of reprogramming. Critically, suppression of SUMO2 also promotes the generation of human iPSCs. Together, our results reveal sumoylation as a crucial post-transcriptional mechanism that resists the acquisition of pluripotency from fibroblasts using defined factors.
Publication Title
A Serial shRNA Screen for Roadblocks to Reprogramming Identifies the Protein Modifier SUMO2.
Sample Metadata Fields
Sex, Specimen part, Time
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The histone chaperone CAF-1 safeguards somatic cell identity.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
Cellular differentiation involves profound changes in the chromatic landscape, yet the mechanisms by which somatic cell identity is subsequently maintained remain incompletely understood. To further elucidate regulatory pathways that safeguard the somatic state, we performed two comprehensive RNAi screens targeting chromatin factors during transcription factor-mediated reprogramming of mouse fibroblasts to induced pluripotent stem cells (iPSCs). Remarkably, subunits of the chromatin assembly factor-1 (CAF-1) complex emerged as the most prominent hits from both screens, followed by modulators of lysine sumoylation and heterochromatin maintenance. Suppression of CAF-1 increased reprogramming efficiency by several orders of magnitude and facilitated iPSC formation in as little as 4 days. Mechanistically, CAF-1 suppression led to a more accessible chromatin structure at enhancer elements early during reprogramming. These changes were accompanied by a decrease in somatic heterochromatin domains, increased binding of Sox2 to pluripotency-specific targets and activation of associated genes. Notably, suppression of CAF-1 also enhanced the direct conversion of B cells into macrophages and fibroblasts into neurons. Together, our findings reveal the histone chaperone CAF-1 as a novel regulator of somatic cell identity during transcription factor-induced cell fate transitions and provide a potential strategy to modulate cellular plasticity in a regenerative setting.
Publication Title
The histone chaperone CAF-1 safeguards somatic cell identity.
Sample Metadata Fields
Specimen part, Time
View Samples- Drosophila melanogaster
- 21 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
Drosophila mosaic eye-antennal discs from the listed genotypes generated using the MARCM system were dissected from 3rd instar larvae at day 5 after egg deposition.
Publication Title
The BTB-zinc finger transcription factor abrupt acts as an epithelial oncogene in Drosophila melanogaster through maintaining a progenitor-like cell state.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 35 Downloadable Samples
- Affymetrix Human Gene 2.1 ST Array (hugene21st)
Description
In this randomised placebo-controlled trial, irritable bowel syndrome (IBS) patients were treated with faecal material from a healthy donor (n=8, allogenic FMT) or with their own faecal microbiota (n=8, autologous FMT). The faecal transplant was administered by whole colonoscopy into the caecum (30 g of stool in 150 ml sterile saline). Two weeks before the FMT (baseline) as well as two and eight weeks after the FMT, the participants underwent a sigmoidoscopy, and biopsies were collected at a standardised location (20-25 cm from the anal verge at the crossing with the arteria iliaca communis) from an uncleansed sigmoid. In patients treated with allogenic FMT, predominantly immune response-related genes sets were induced, with the strongest response two weeks after FMT. In patients treated with autologous FMT, predominantly metabolism-related gene sets were affected.
Publication Title
Allogenic Faecal Microbiota Transfer Induces Immune-Related Gene Sets in the Colon Mucosa of Patients with Irritable Bowel Syndrome.
Sample Metadata Fields
Age, Specimen part, Subject
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Imatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound 1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells.
Publication Title
Early in vivo changes of the transcriptome in Philadelphia chromosome-positive CD34+ cells from patients with chronic myelogenous leukaemia following imatinib therapy.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 36 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
The molecules RhoC and RhoA are essential factors for invasion/metastasis of tumor cells proliferation, respectively. RhoC over-expression was especially linked to aggressive cancers, which requires loss of epithelial polarity and deregulation of cellular adhesion. This epithelial-mesenchymal transition (EMT) includes a change in gene expression pattern through several transcription factors, like Snail, ZEB1 or Twist. Here we analyze the potential of RhoC to induce EMT, migration and invasion and to regulate specific genes involved in tumorigenesis. We established stable MCF-10A cell lines with RhoA/RhoC expression under the control of a doxycycline-regulated trans-activator and a transcriptional silencer allowing conditional expression of RhoA and RhoC, respectively. We additionally quantified the transcriptional response from two bacterial toxins: Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1) and Yersinia pseudotuberculosis Cytotoxic Necrotizing Factor (CNFY) to directly activate the endogenous pool of Rho GTPases and characterized changes in morphology, migration and invasion upon induction of RhoA/RhoC expression or activation by the toxins in MCF-10A grown in two- and three-dimensions. The transcriptome response identified PTGS2 as RhoC specific target genes involved in pro-migratory changes which was experimentally validated.
Publication Title
Specific role of RhoC in tumor invasion and metastasis.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Human intervention study with two doses of iron (as ferrous gluconate via intestinal perfusion) to study the effect on genome-wide gene expression in the small intestine, in order to obtain detailed information about intestinal transcriptomics in vivo.
Publication Title
Gene expression in human small intestinal mucosa in vivo is mediated by iron-induced oxidative stress.
Sample Metadata Fields
Sex, Disease, Disease stage, Subject
View Samples