Project description:We have investigated the functional relevance of the transcriptional network controlled by the Otx2 binding activity in ESCs, EpiSCs and in vivo. In particular, to study the Otx2 transcriptional network we first performed Otx2 chromatin immunoprecipitation sequencing (ChIP-seq) experiments in wt ESCs and day 4 (d4) ESC-derived EpiSCs and employed as negative control ESCs and EpiSCs lacking Otx2. Moreover, to investigate the functional relevance of the Otx2 binding activity in pluripotent stem cells, we mutagenized in ESCs the Otx2 binding site located upstream of the Nanog TSS. To characterize the identity of ESCs and EpiSCs both lacking this Otx2 binding site, we analyzed their transcriptome by RNA-Seq.
Project description:Naïve and primed pluripotency is characterized by distinct signaling requirements, transcriptomes and developmental properties, but both cellular states share key transcriptional regulators, Oct4, Sox2 and Nanog. Here we demonstrate that transition between these two pluripotent states is associated with widespread Oct4 relocalization, mirrored by global rearrangement of enhancer chromatin landscapes. Our genomic and biochemical analyses identified candidate mediators of primed state-specific Oct4 binding, including Otx2 and Zic2/3. Even in the absence of other differentiation cues, premature Otx2 overexpression is sufficient to exit the naïve state, induce transcription of a large subset of primed pluripotency-associated genes and redirect Oct4 to thousands of previously inaccessible sites. However, ability of Otx2 to engage new enhancer regions is determined by its levels, cis-encoded properties of the sites and signaling environment. Our results illuminate regulatory mechanisms underlying pluripotency and suggest that capacity of transcription factors such as Otx2 and Oct4 to function as pioneers is highly context-dependent transcription profile of ESCs and EpiLCs to analzye changes during differentiation and the effect of Otx2 loss and overexpression on the differentiation properties
Project description:We reported H3K4me3, H3K27ac and H3K27me3 histone modification in EpiSCs and Nodal inhibited EpiSCs(EpiSCS/F). Using ChIP sequencing, we demonstrate that the active modification of H3K4me3 and H3K27ac level are higher in EpiSCS/F, suggesting EpiSCsS/F were in an active chromatin state. Interestingly, H3K27me3, the supressive modification enriched more in EpiSCS/F down regulated genes, suggesting H3K27me3 plays pivital roles in regulating gene expression.
Project description:Naïve and primed pluripotency is characterized by distinct signaling requirements, transcriptomes and developmental properties, but both cellular states share key transcriptional regulators, Oct4, Sox2 and Nanog. Here we demonstrate that transition between these two pluripotent states is associated with widespread Oct4 relocalization, mirrored by global rearrangement of enhancer chromatin landscapes. Our genomic and biochemical analyses identified candidate mediators of primed state-specific Oct4 binding, including Otx2 and Zic2/3. Even in the absence of other differentiation cues, premature Otx2 overexpression is sufficient to exit the naïve state, induce transcription of a large subset of primed pluripotency-associated genes and redirect Oct4 to thousands of previously inaccessible sites. However, ability of Otx2 to engage new enhancer regions is determined by its levels, cis-encoded properties of the sites and signaling environment. Our results illuminate regulatory mechanisms underlying pluripotency and suggest that capacity of transcription factors such as Otx2 and Oct4 to function as pioneers is highly context-dependent ChIP-seq analysis was performed to map enhancers and associated transcription factors. We used H3K27ac, H3K4me1 and p300 to call enhancers from 2 different pluripotent cell states: ESC and EpiLC. In addition we performed ChIP-seq for Oct4 and Otx2 from these cell states. All these experiments were carried out in replicates, for the EpiLC state the replicates were performed with and without ActivinA. Additionally we carried out ChIPseq for Otx2 and Oct4 in Otx2ko cell lines in which we integrated an inducible Otx2 gene before and after induction with doxycycline.
Project description:Embryonic stem cells (ESCs) comprise at least two populations of cells with divergent states of pluripotency. Here, we show that epiblast stem cells (EpiSCs) also comprise two distinct cell populations that can be distinguished by the expression of a specific Oct4-GFP marker. These two subpopulations, Oct4-GFP positive and negative EpiSCs, are capable of converting into each other in vitro. Oct4-GFP positive and negative EpiSCs are distinct from ESCs with respect to global gene expression pattern, epigenetic profile, and Oct4 enhancer utilization. Oct4-GFP negative cells share features with cells of the late mouse epiblast and cannot form chimeras. However, Oct4-GFP positive EpiSCs, which only represent a minor EpiSC fraction, resemble cells of the early epiblast and can readily contribute to chimeras. Our findings suggest that the rare ability of EpiSCs to contribute to chimeras is due to the presence of the minor EpiSC fraction representing the early epiblast. RNA samples to be analyzed on microarrays were prepared using Qiagen RNeasy columns with on-column DNA digestion. 300 ng of total RNA per sample was used as input into a linear amplification protocol (Ambion), which involved synthesis of T7-linked double-stranded cDNA and 12 hrs of in-vitro transcription incorporating biotin-labelled nucleotides. Purified and labelled cRNA was then hybridized for 18 hrs onto MouseRef-8 v2 expression BeadChips (Illumina) according to the manufacturer's instructions. After washing, as recommended, chips were stained with streptavidin-Cy3 (GE Healthcare) and scanned using the iScan reader (Illumina) and accompanying software. Samples were hybridized as biological replicates. 6 samples were analyzed, five of them in duplicate and one of them (T9-EpiSC) a single time (11 total samples). ESC: Mouse ESC male; EpiSC: Mouse EpiSC male GOF18; Epi-Sox2: Mouse EpiSC Sox2 male GOF18 (Overexpressing WT Sox2) cultured in condition EpiSC medium (CM); EpiSC-GFP-: Mouse E3 EpiSC grown in CM and FACS-sorted for GFP-; EpiSC-GFP+: Mouse E3 EpiSC grown in CM and FACS-sorted for GFP+; T9-EpiSC: Mouse T9 EpiSC grown on medium-density CF1 MEFs in UM, 2d -Fgf2, harvested without MEFs. The supplementary file 'GSE17984_non-normalized_data.txt' contains non-normalized data for Samples GSM450294-GSM450304.
Project description:Naïve and primed pluripotency is characterized by distinct signaling requirements, transcriptomes and developmental properties, but both cellular states share key transcriptional regulators, Oct4, Sox2 and Nanog. Here we demonstrate that transition between these two pluripotent states is associated with widespread Oct4 relocalization, mirrored by global rearrangement of enhancer chromatin landscapes. Our genomic and biochemical analyses identified candidate mediators of primed state-specific Oct4 binding, including Otx2 and Zic2/3. Even in the absence of other differentiation cues, premature Otx2 overexpression is sufficient to exit the naïve state, induce transcription of a large subset of primed pluripotency-associated genes and redirect Oct4 to thousands of previously inaccessible sites. However, ability of Otx2 to engage new enhancer regions is determined by its levels, cis-encoded properties of the sites and signaling environment. Our results illuminate regulatory mechanisms underlying pluripotency and suggest that capacity of transcription factors such as Otx2 and Oct4 to function as pioneers is highly context-dependent
Project description:Naïve and primed pluripotency is characterized by distinct signaling requirements, transcriptomes and developmental properties, but both cellular states share key transcriptional regulators, Oct4, Sox2 and Nanog. Here we demonstrate that transition between these two pluripotent states is associated with widespread Oct4 relocalization, mirrored by global rearrangement of enhancer chromatin landscapes. Our genomic and biochemical analyses identified candidate mediators of primed state-specific Oct4 binding, including Otx2 and Zic2/3. Even in the absence of other differentiation cues, premature Otx2 overexpression is sufficient to exit the naïve state, induce transcription of a large subset of primed pluripotency-associated genes and redirect Oct4 to thousands of previously inaccessible sites. However, ability of Otx2 to engage new enhancer regions is determined by its levels, cis-encoded properties of the sites and signaling environment. Our results illuminate regulatory mechanisms underlying pluripotency and suggest that capacity of transcription factors such as Otx2 and Oct4 to function as pioneers is highly context-dependent
Project description:We discovered a role for the transcription factor OTX2 in formation of mouse definitive endoderm (DE). We used CUT&RUN to map OTX2-bound genomic regions and identify OTX2-regulated genes during directed differentiation of EpiSCs to DE
Project description:The transition of embryonic stem cells from the epiblast stem cells (EpiSCs) to neural progenitor cells (NPCs), name as the neural induction process, is crucial for cell fate determination of neural differentiation. However, the mechanism of this transition is unclear. Here, we identified a long non-coding RNA (linc1548) as a critical regulator of neural differentiation of mouse embryonic stem cells (mESCs). Knockout of linc1548 did not affect the conversion of mESCs to EpiSCs, but delayed the transition from EpiSCs to NPCs. Moreover, linc1548 interacts with the transcription factors OCT6 and SOX2 forming an RNA-protein complex to regulate the transition from EpiSCs to NPCs. Finally, we showed that Zfp521 is an important target gene of this RNA-protein complex regulating neural differentiation. Our findings prove how the intrinsic transcription complex mediated by a lncRNA linc1548 and can better understand the intrinsic mechanism of neural fate determination.