Effect of LIF on ES cells overexpressing Akt
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE2516 | GEO | 2005/04/12
SECONDARY ACCESSION(S): PRJNA92053
REPOSITORIES: GEO
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Project description:Embryonic stem (ES) cells can self-renew indefinitely without losing their differentiation ability to any cell types. Phosphoinositide-3 kinase (PI3K)/Akt signaling plays a pivotal role in various stem cell systems, including the formation of embryonic germ (EG) cells from primordial germ cells and self-renewal of neural stem cells. Here, we show that myristoylated, active form of Akt (myr-Akt) maintained the undifferentiated phenotypes in mouse ES cells without the addition of leukemia inhibitory factor (LIF). The effects of myr-Akt were reversible, because LIF dependence and pluripotent differentiation activity were restored by the deletion of myr-Akt. In addition, myr-Akt-Mer fusion protein, whose enzymatic activity is controlled by 4-hydroxy-tamoxifen, also maintained the pluripotency of not only mouse but also cynomolgus monkey ES cells. These results clearly demonstrate that Akt signaling sufficiently maintains pluripotency in mouse and primate ES cells, and support the notion that PI3K/Akt signaling axis regulates 'stemness' in a broad spectrum of stem cell systems.
2008-06-12 | E-GEOD-2516 | biostudies-arrayexpress
Project description:Homozygous disruption of Bteb2/Klf5, a homolog of Drosophila gap gene Krüppel, led to increased expression of various differentiation marker genes, such as Fgf5, Cdx2, and Brachyury in mouse ES cells without compromising their ability to differentiate into all three germ layers. Upon removal of LIF, Klf5-deficient ES cells showed faster differentiation kinetics than wild-type ES cells. In contrast, overexpression of Klf5 in ES cells suppressed the transcription of differentiation marker genes, and maintained pluripotency in the absence of LIF. In order to search downstream genes of Klf5, we surveyed genes implicated in ES cell proliferation by microarray analysis Keywords: cell type comparison
2008-12-31 | GSE9244 | GEO
Project description:This experiment is part of the FunGenES project (FunGenES - Functional Genomics in Embryonic Stem Cells partially funded by the 6th Framework Programme of the European Union, http://www.fungenes.org).The experiment was conducted at the Unyversity of Bath, Bath, UK. Aim of the experiment is the identification of genes regulated by PI3K-dependent signaling in undifferentiated ES cells. Materials and methods: To identify target genes of PI3-K signalling, the PI3-K signalling inhibitor LY294002 was used at a concentration which was shown to perturb self-renewal in the presence of LIF and which knocks down PI3K signals. CGR8 cells cultivated in serum-free conditions in the presence of LIF were starved for 24h in media lacking LIF and then pre-inubated for 30 minutes with 5 mM LY294002 in DMSO or with DMSO alone. Cells were then stimulated with LIF for 2h, prior to preparation of RNA samples. Relationships between samples: Samples were either maintained in LIF or LIF plus LY294002 (PI3K inhibitor) for the required treatment times. Treatments: Treatment times with PI3K inhibitor LY294002 at 5 uM 2h (n=5), 3h (n=5).
2009-05-07 | E-TABM-673 | biostudies-arrayexpress
Project description:This experiment is part of the FunGenES project (FunGenES - Functional Genomics in Embryonic Stem Cells partially funded by the 6th Framework Programme of the European Union, http://www.fungenes.org).The experiment was conducted at the Unyversity of Bath, Bath, UK. Aim is to identify genes regulated by PI3K-dependent signaling in undifferentiated ES cells. Materials and methods: E14tg2a cell line was used. Cells were cultured in Knock-out DMEM supplemented with 15% (v/v) Knock-out serum replacement, 1000U/ml LIF, 2mM glutamine, 50 ?M 2-mercaptothanol and 1x NEAA (as described in Handbook of work methods, 4.3.1.1). Cells were plated at 5x105 per 10cm gelatin-coated TC dish for 24h. ES cells were then starved for 24h in media lacking LIF and pre-incubated for 30 minutes with 5 <B5>M LY294002 (the concentration of this PI3K inhibitor that we have shown to perturb self-renewal in the presence of LIF and which knocks down PI3K signals) or DMSO alone. Cells were then stimulated with 103U/ml mLIF (Chemicon) for 2h (which gave maximal activation of STAT3), 24h, 48h or 72h.</p>\n<h3>Relationships between samples</h3>\n <p ALIGN="JUSTIFY">Samples were either maintained in LIF or LIF plus LY294002 (PI3K inhibitor) for the required treatment times.</p>\n<h3>Treatments</h3>\n <p ALIGN="JUSTIFY">Treatment times with PI3K inhibitor LY294002 at 5 <B5>M <96> 2h (n=5), 24h (n=3), 48h (n=3), 72h (n=3). DMSO was used as vehicle alone treatment control.</p>\n<h3>Culture conditions</h3>\n <p ALIGN="JUSTIFY">Gelatin-coated TC dishes (Nunc)</p>\n<h3>RNA isolation method</h3>\n <p ALIGN="JUSTIFY">RNA Easy with on-column DNase treatment</p>\n<h3>Experimental description</h3>\n <p ALIGN="JUSTIFY">This information is included above. Briefly, E14tg2a ES cells were either maintained in LIF or LIF plus LY294002 (5 <B5>M) for 2, 24, 48 or 72 hours, after which RNA was extracted from each sample and sent for expression profiling. During this time-course, only 72h time points plus LY294002 showed phenotypic evidence of differentiation. </p>\n
2009-05-07 | E-TABM-674 | biostudies-arrayexpress
Project description:In this study we have analyzed the global gene expression of naïve mouse embryonic stem cells in different culture conditions including R2i (PD0325901+SB431542), 2i (PD0325901+CHIR99021), and also PD0325901+LIF and SB431542+LIF to show the similarities and differences between the conditions in maintaining pluripotency. Since the first generation of mouse embryonic stem (ES) cells, extrinsic regulation of pluripotency has been at the focus of attention. Here we show that suppression of transforming growth factor β (TGFβ) signaling could have impressive effects on self-renewal and pluripotency of mouse ES cells. We introduce a chemically defined medium with inhibitors of TGFβ and mitogen-activated protein kinase (MAPK) kinase, designated here as R2i (Royan 2 inhibitors), for highly efficient establishment of ES cell lines from various mouse strains. R2i also supports homogenous expression of Nanog and Dppa3 proteins in ES cells and shows minimal differentiation leakage. Our results uncover an appropriate condition for ES cell generation from single blastomeres of various cleavage-stage embryos. Further, the high accuracy of genome integrity after long-term cultivation in R2i illustrates an optimal condition for ES cell culture. Global transcriptomic analysis of R2i cells demonstrates that bone morphogenetic protein 4 (BMP4) signaling becomes overrepresented pursuant to TGFβ repression, which may confer further robustness to pluripotency through shielding cells from differentiation stimuli. These findings point to a new facet of ground state pluripotency by blocking differentiation pathways, without influencing the pluripotency regulatory circuitry of mouse ES cells. Whole gene expression study of 4 different mouse embryonic stem cell lines maintained under 4 different chemically defined conditions: R2i, 2i, PD and SB
2013-10-21 | E-GEOD-43682 | biostudies-arrayexpress
Project description:The pluripotency of mouse embryonic stem cells (ESC) and induced-pluripotent stem cells (iPSC) can be maintained by feeder cells, which secrete Leukemia Inhibitory Factor (LIF). We found that feeder cells provide a relatively low concentration (25 unit/ml) of LIF, which is insufficient to maintain the ESC/iPSC pluripotency in feeder free conditions. In order to identify additional factors involved in the maintenance of pluripotency, we carried out a global transcript expression profiling of mouse iPSC cultured on feeder cells and in feeder-free (LIF-treated) conditions. This identified 17 significantly differentially expressed genes (adjusted p-value<0.05) including 7 chemokines over-expressed in iPSC grown on feeder cells. Ectopic expression of these chemokines in iPSC revealed that CC chemokine ligand 2 (Ccl2) induced the key transcription factor genes for pluripotency, Klf4, Nanog, Sox2 and Tbx3. Further, addition of recombinant Ccl2 protein drastically increased the number of Nanog-GFP-positive iPSC grown in low LIF feeder free conditions. Interestingly, this effect was not observed in the absence of LIF. We further revealed that pluripotency promotion by Ccl2 is mediated by activating the Stat3-pathway followed by Klf4 up-regulation. We demonstrated that Ccl2 mediated increased pluripotency is independent of PI3K and MAPK pathways and that Tbx3 may be directly up-regulated by Klf4. Overall, Ccl2 cooperatively activates the Stat3-pathway with LIF in feeder free condition to maintain pluripotency for ESC/iPSC.
2011-06-01 | GSE28262 | GEO
Project description:The pluripotency of mouse embryonic stem cells (ESC) and induced-pluripotent stem cells (iPSC) can be maintained by feeder cells, which secrete Leukemia Inhibitory Factor (LIF). We found that feeder cells provide a relatively low concentration (25 unit/ml) of LIF, which is insufficient to maintain the ESC/iPSC pluripotency in feeder free conditions. In order to identify additional factors involved in the maintenance of pluripotency, we carried out a global transcript expression profiling of mouse iPSC cultured on feeder cells and in feeder-free (LIF-treated) conditions. This identified 17 significantly differentially expressed genes (adjusted p-value<0.05) including 7 chemokines over-expressed in iPSC grown on feeder cells. Ectopic expression of these chemokines in iPSC revealed that CC chemokine ligand 2 (Ccl2) induced the key transcription factor genes for pluripotency, Klf4, Nanog, Sox2 and Tbx3. Further, addition of recombinant Ccl2 protein drastically increased the number of Nanog-GFP-positive iPSC grown in low LIF feeder free conditions. Interestingly, this effect was not observed in the absence of LIF. We further revealed that pluripotency promotion by Ccl2 is mediated by activating the Stat3-pathway followed by Klf4 up-regulation. We demonstrated that Ccl2 mediated increased pluripotency is independent of PI3K and MAPK pathways and that Tbx3 may be directly up-regulated by Klf4. Overall, Ccl2 cooperatively activates the Stat3-pathway with LIF in feeder free condition to maintain pluripotency for ESC/iPSC. Total RNAs were purified from feeder cells (as a reference sample), iPSC grown on feeder cells and iPSC grown in feeder-free condition in triplicates and applied to the arrays. iPSC grown on feeder cells were separated mechanically from the feeder layer to minimize feeder cell contamination.
2011-06-01 | E-GEOD-28262 | biostudies-arrayexpress
Project description:Pluripotent stem cells have been shown to have unique nuclear properties, e.g., hyperdynamic chromatin and large, condensed nucleoli. However, the contribution of the latter unique nucleolar character to pluripotency has not been well understood. Here, we show fibrillarin (FBL), a critical methyltransferase for ribosomal RNA (rRNA) processing in nucleoli, as one of the proteins highly expressed in pluripotent embryonic stem (ES) cells. Stable expression of FBL in ES cells prolonged the pluripotent state of mouse ES cells cultured in the absence of leukemia inhibitory factor (LIF). Analyses using deletion mutants and a point mutant revealed that the methyltransferase activity of FBL regulates stem cell pluripotency. Knock down of this gene led to significant delays in rRNA processing, growth inhibition, and apoptosis in mouse ES cells. Interestingly, both partial knock down of FBL and treatment with actinomycin D, an inhibitor for rRNA synthesis, induced the expression of differentiation markers in the presence of LIF and promoted stem cell differentiation into neuronal lineages. Moreover, we identified p53 signaling as the regulatory pathway for pluripotency and differentiation of ES cells. These results suggest that proper activity of rRNA production in nucleoli is a novel factor for the regulation of pluripotency and differentiation ability of ES cells. Tc-inducible FBL-knock down ES cells were cultured for 2 days with or without Tc in the presence of LIF. These 2 conditions were analysed transcription profile.
2014-08-01 | E-GEOD-51139 | biostudies-arrayexpress
Project description:The goal of this study was to identify the target genes of Stat3 involved in murine ES cell self-renewal. To achieve this goal, we used the Gs2 ES cell line expressing an inducible dominant negative mutant of Stat3 (Stat3F) in wich Y705 is mutated to phenilalanine. The Gs2 ES cells are routinely maintained in the presence of LIF 1000 U/ml and tetracycline 1µg/ml (LIF/ON). In this condition, Stat3F is not expressed and the cells are maintained in an undifferentiated phenotype. Upon tetracycline removal but inthe presence of LIF (Tet OFF condition) Stat3F is expressed and the cells differentiate despite the presence of LIF. We thus performed microarray analysis of the transcriptome of ES cells after 16h, 24h and 48h after Tetracycline removal (OFF16; OFF24 and OFF48) respectively)and compared them to Gs2 ES cells maintained in the continuous presence of LIF and tetracyclin (LIF/ON). Keywords: time-course
2004-07-01 | GSE1151 | GEO