ShRNA-mediated silencing of candidate pluripotency regulators in mouse epibladst stem cells
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ABSTRACT: EpiSC-5 mouse epiblast stem cells were transduced with lentiviral vectors carrying shRNA for MR candidate genes or non-targeting controls. Expression profile was obtained 72h after transduccion.
Project description:Human Burkitt's lymphoma ST486 cells were transduced with non-target control shRNA lentiviral vectors, FOXM1 shRNA, and MYB shRNA lentiviral vectors. Total RNA was isolated 24h later. cRNA was produced with the standard one-step IVT protocol (Affymetix) and hybridized in U95Av2 gene chips (Affymetrix).
Project description:Blimp1 (Prdm1), the key determinant of primordial germ cells (PGC), plays a combinatorial role with Prdm14 during PGC specification from postimplantation epiblast cells. They together initiate epigenetic reprogramming in early germ cells towards an underlying pluripotent state, which is equivalent to embryonic stem cells (ESC). Whereas Prdm14 alone can promote reprogramming and is important for the propagation of the pluripotent state, it is not known if Blimp1 is similarly involved. Using a genetic approach, we demonstrate that Blimp1 is dispensable for the derivation and maintenance of ESC and postimplantation epiblast stem cells (EpiSC). Notably, Blimp1 is also dispensable for reprogramming EpiSC to ESC. Thus, while Blimp1 is obligatory for PGC specification, it is not required for the reversion of EpiSC to ESC, and for their maintenance thereafter. This study suggests that reprogramming, including that of somatic cells to ESC, may not entail an obligatory route through Blimp1 positive PGC-like state.
Project description:We performed an integrated analysis of RNA and proteins at the transition between naïve ES cells and cells primed to differentiate. During this transition, mRNAs coding for chromatin regulators were specifically released from translational inhibition mediated by RNA-Induced Silencing Complex (RISC). This suggests that, prior to differentiation, the propensity of ES cells to change their epigenetic status is hampered by RNA interference. The expression of these chromatin regulators was reinstated following acute inactivation of RISC, and it correlated with loss of stemness markers and activation of early cell differentiation markers in treated ES cells. Comparison between EpiSC derived directly from mouse embryonic stem cells and from Epiblast-Like Aggregates
Project description:Sox2 is a key transcription factor directing embryonic stem cell (ESC) pluripotency. However, the role of SoxB1 proteins in epiblast stem cell (EpiSC) pluripotency is unknown. Here we compare the transcriptomes of pluripotent cells cultured in different conditions that express different levels of Sox2. While highest Sox2 level in ESCs are enriched for naive pluripotency markers, ESCs and EpiSCs expressing the same Sox2 level were transcriptionally distinct. Thus Sox2 levels do not dictate the distinction between ESC and EpiSC states.
Project description:Human Burkitt's lymphoma ST486 cells were transduced with non-target control shRNA lentiviral vectors, FOXM1 shRNA, and MYB shRNA lentiviral vectors. Total RNA was isolated 24h later. cRNA was produced with the standard one-step IVT protocol (Affymetix) and hybridized in U95Av2 gene chips (Affymetrix). Experiment consists in 3 independent samples: Expression profiling of Burkitt's lymphoma cells 24h after non-target control shRNA lentiviral mediated transduction. Expression profiling of Burkitt's lymphoma cells 24h after FOXM1 shRNA lentiviral mediated transduction. Expression profiling of Burkitt's lymphoma cells 24h after MYB shRNA lentiviral mediated transduction. Data processing performed using MAS5 or GCRMA.
Project description:Transcriptional profiling of mouse embryonic, epiblast-derived, stem cells (epiSC). epiSC differentiated towards the dopaminergic phenotype were compared to control untreated epiSC. EpiSc were derived from a Pitx3-GFP mouse allowing visualization of dopaminergic (GFP+) differentiation efficiency.
Project description:Small-RNA profiling of mouse embryonic, epiblast-derived, stem cells (epiSC). epiSC differentiated towards the dopaminergic phenotype were compared to control untreated epiSC. EpiSc were derived from a Pitx3-GFP mouse allowing visualization of dopaminergic (GFP+) differentiation efficiency.
Project description:HCT116 cells transfected with lentiviral vectors expressing two different N-BLR shRNAs (clones #3-1 and #4-7) and empty vector control
Project description:Epiblast stem cells (EpiSC) are pluripotent stem cells derived from mouse postimplantation embryos between E5.5 to E7.5, a time window in which gastrulation commences. Therefore, EpiSC represent a valuable tool for studying mammalian postimplantation development in vitro. Beyond their pluripotent features, EpiSC can also be reprogrammed into a mouse embryonic stem cell-like (mESC) state. Published reports showed that EpiSC reversion requires transcription factor overexpression, while others suggest that applying stringent mESC culture conditions alone was sufficient to revert EpiSC to mESC-like cells. In an effort to clarify these discrepancies, we systematically compared a panel of independent EpiSC lines. Indeed, the different lines shared a number of defining EpiSC characteristics such as teratoma formation ability, regardless of the day of isolation from the embryo. However, despite being grown in identical, self-renewal-promoting conditions, some lines displayed strong expression of genes associated with mesendodermal differentiation. Strikingly, these same lines were not revertable to a mESC-like state by applying stringent mESC culture conditions. Moreover, expression of mesendodermal marker genes correlated in a negative manner with the ability to efficiently undergo neural induction. Overall, our data suggest that different EpiSC lines may self-renew in distinct developmental ground states, which has important consequences for functional readouts such as revert ability to a mESC-like state and directed differentiation. For EpiSC lines derivation E5.5 embryos were plated onto irradiated mouse embryonic feeder cells (MEF cells) seeded at low density. Outgrowths were picked and expanded manually. Basal medium consisted of Knock-Out-DMEM, 20% Knock-Out Serum Replacement, Non Essential Amino Acids, L-Glutamine and beta-Mercaptoethanol (all Gibco). For cultivation on feeders 5ng/ml bFGF (Peprotech) was added to the medium to yield EpiSC medium. For preparation of mouse embryonic fibroblast-conditioned medium, EpiSC medium incubated on inactivated MEFs, followed by addition of another 5ng/ml bFGF (CM+). For feeder free culture, EpiSCs were seeded onto FCS-coated dishes. EpiSC were routinely passaged using 1mg/ml Collagenase IV (Invitrogen). Mouse ESC were cultured in standard conditions - Knock-Out-DMEM, 15% Knock-Out Serum Replacement (both Gibco), 5% fetal calf serum (Biowest), Non Essential Amino Acids, L-Glutamine and beta-Mercaptoethanol (all Gibco), supplemented with either homemade or commercially available LIF (ESGRO) at 1000U/ml. Some experiments were carried out in chemically defined N2B27 medium 11 in the presence of 10ng/ml bFGF. For reversion experiments, EpiSC were harvested using Accutase (Invitrogen) and seeded as single cells at approximately 16.000 cells / well of a 6-well plate (Sarstedt) in CM+. After 24h medium was changed to PCL medium (basal medium, LIF (1000U/ml), PD0325901 (Axon Medchem 1µM), and CHIR99021 (Axon Medchem 3µM). After 48h treatment, reversion medium was further supplemented with 10µM SB431542 (Sigma) to eliminate remaining EpiSC.