Project description:Induction of the Arf tumor suppressor in response to hyperproliferative stress following oncogene activation activates a p53-dependent transcriptional program that limits the expansion of incipient cancer cells. Although Arf is not expressed in most tissues of fetal or young adult mice, it is physiologically expressed in the fetal yolk sac, a tissue derived from the extraembryonic endoderm. We demonstrate that expression of the mouse p19Arf protein marks late stages of extraembryonic endoderm differentiation in cultured embryoid bodies derived from either embryonic stem cells or induced pluripotent stem cells, and that Arf inactivation specifically delays the differentiation of the extraembryonic endoderm lineage, but not the formation of other germ cell lineages from pluripotent progenitors. Arf is required for the timely induction of extraembryonic endodermal cells in response to Ras/Erk signaling and, in turn, acts through p53 to ensure extraembryonic endoderm lineage development, but not maintenance. Remarkably, a significant temporal delay in extraembryonic endoderm differentiation detected during the maturation of Arf-null embryoid bodies is rescued by enforced expression of miR-205, a micro-RNA up-regulated by p19Arf and p53. Introduction of miR-205 into Arf-null embryonic stem cells rescues defective ExEn formation and elicits a program of gene expression that controls the migration and adhesion of embryonic endodermal cells. This occurs, at least in part, through atypical regulation of genes that control the epithelial-to-mesenchymal transition in cancer cells. Our findings suggest that noncanonical and canonical roles of Arf in extraembryonic endoderm development and tumor suppression, respectively, may be conceptually linked through mechanisms that govern cell-to-cell attachment and migration. 4 samples total two each at two time points in ESC development At each time point one sample was treted with miR-205 and the other with a GFP control vector
Project description:Metabolism is vital to cellular function and tissue homeostasis during human lung development. In utero, embryonic pluripotent stem cells undergo endodermal differentiation towards a lung progenitor cell fate that can be mimicked in vitro using induced human pluripotent stem cells (hiPSCs) to study genetic mutations. To identify differences between wild type and surfactant protein B (SFTPB)-deficient cell lines during endoderm specification towards lung, we used an untargeted metabolomics approach to evaluate the developmental changes in metabolites. We found that the metabolites most enriched during the differentiation from pluripotent stem cell to lung progenitor cell, regardless of cell line, were sphingomyelins and phosphatidylcholines, two important lipid classes in fetal lung development. The SFTPB mutation had no metabolic impact on early endodermal lung development. The identified metabolite signatures during lung progenitor cell differentiation may be utilized as biomarkers for normal embryonic lung development.
Project description:Faithful embryogenesis requires the precise coordination between embryonic and extraembryonic tissues. Although embryonic and extraembryonic stem cells have been derived from several mammalian species including humans, they are cultured in different conditions, which makes it difficult to study their intercommunication. Here, by simultaneously activating FGF, TGF-β and WNT pathways, we derived stable pluripotent stem cells (PSCs), trophoblast stem cells (TSCs) and extraembryonic endoderm stem cells (XENs) from mouse blastocysts under the same condition (FTW). Co-culture of PSCs and XENs in the same environment uncovered, among other interactions, a previously unrecognized control of proliferation of epiblast cells by extraembryonic endoderm cells. FTW condition also supported de novo derivation of XENs from cynomolgus monkey and human blastocysts, and enabled setting up co-culture of human iPSCs and XENs. Crosspieces comparison revealed conserved and divergent processes and genes regulating XENs and ligand-receptor interactions between pluripotent and extraembryonic endoderm cells. Our study establishes a unique stem cell co-culture strategy to examine embryonic and extraembryonic lineage crosstalk during early mammalian development, and opens the door for developing more faithful in vitro models and differentiation protocols.
Project description:Faithful embryogenesis requires the precise coordination between embryonic and extraembryonic tissues. Although embryonic and extraembryonic stem cells have been derived from several mammalian species including humans, they are cultured in different conditions, which makes it difficult to study their intercommunication. Here, by simultaneously activating FGF, TGF-β and WNT pathways, we derived stable pluripotent stem cells (PSCs), trophoblast stem cells (TSCs) and extraembryonic endoderm stem cells (XENs) from mouse blastocysts under the same condition (FTW). Co-culture of PSCs and XENs in the same environment uncovered, among other interactions, a previously unrecognized control of proliferation of epiblast cells by extraembryonic endoderm cells. FTW condition also supported de novo derivation of XENs from cynomolgus monkey and human blastocysts, and enabled setting up co-culture of human iPSCs and XENs. Crosspieces comparison revealed conserved and divergent processes and genes regulating XENs and ligand-receptor interactions between pluripotent and extraembryonic endoderm cells. Our study establishes a unique stem cell co-culture strategy to examine embryonic and extraembryonic lineage crosstalk during early mammalian development, and opens the door for developing more faithful in vitro models and differentiation protocols.
Project description:Bone morphogenetic protein (BMP) signaling is known to support differentiation of human embryonic stem cells (hESCs) into mesoderm and extraembryonic lineages, whereas other signaling pathways can largely influence this lineage specification. Here, we set out to reinvestigate the influence of ACTIVIN/NODAL and fibroblast growth factor (FGF) pathways on the lineage choices made by hESCs during BMP4-driven differentiation. We show that BMP activation, coupled with inhibition of both ACTIVIN/NODAL and FGF signaling, induces differentiation of hESCs, specifically to M-NM-2hCG hormone-secreting multinucleated syncytiotrophoblast and does not support induction of embryonic and extraembryonic lineages, extravillous trophoblast, and primitive endoderm. It has been previously reported that FGF2 can switch BMP4-induced hESC differentiation outcome to mesendoderm. Here, we show that FGF inhibition alone, or in combination with either ACTIVIN/NODAL inhibition or BMP activation, supports hESC differentiation to hCG-secreting syncytiotrophoblast. We show that the inhibition of the FGF pathway acts as a key in directing BMP4-mediated hESC differentiation to syncytiotrophoblast. Human embryonic Stem Cells (hESCs) were treated under defined conditions (N2B27) with BMP4 (B), SB431542 (SB) (ACTIVIN/NODAL inhibitor), SU5402 (SU) (FGFR1 inhibitor), FGF2 (F) either alone or in various combinations as mentioned, followed by isolation of total RNA.
Project description:Induction of the Arf tumor suppressor in response to hyperproliferative stress following oncogene activation activates a p53-dependent transcriptional program that limits the expansion of incipient cancer cells. Although Arf is not expressed in most tissues of fetal or young adult mice, it is physiologically expressed in the fetal yolk sac, a tissue derived from the extraembryonic endoderm. We demonstrate that expression of the mouse p19Arf protein marks late stages of extraembryonic endoderm differentiation in cultured embryoid bodies derived from either embryonic stem cells or induced pluripotent stem cells, and that Arf inactivation specifically delays the differentiation of the extraembryonic endoderm lineage, but not the formation of other germ cell lineages from pluripotent progenitors. Arf is required for the timely induction of extraembryonic endodermal cells in response to Ras/Erk signaling and, in turn, acts through p53 to ensure extraembryonic endoderm lineage development, but not maintenance. Remarkably, a significant temporal delay in extraembryonic endoderm differentiation detected during the maturation of Arf-null embryoid bodies is rescued by enforced expression of miR-205, a micro-RNA up-regulated by p19Arf and p53. Introduction of miR-205 into Arf-null embryonic stem cells rescues defective ExEn formation and elicits a program of gene expression that controls the migration and adhesion of embryonic endodermal cells. This occurs, at least in part, through atypical regulation of genes that control the epithelial-to-mesenchymal transition in cancer cells. Our findings suggest that noncanonical and canonical roles of Arf in extraembryonic endoderm development and tumor suppression, respectively, may be conceptually linked through mechanisms that govern cell-to-cell attachment and migration.
Project description:Transcription factor-mediated reprogramming is a powerful method to study cell fate changes. In this work, we demonstrate that the transcription factor Gata6 can initiate reprograming of multiple cell types to induced extraembryonic endoderm (iXEN) cells. Intriguingly, Gata6 is sufficient to drive iXEN cells from mouse pluripotent cells and differentiated neural cells. Furthermore, GATA6 induction in human ES (hES) cells also downregulates pluripotency gene expression and upregulates extraembryonic endoderm genes, revealing a conserved function in mediating this cell fate switch. Profiling transcriptional changes following Gata6 induction in mES cells reveals step-wise pluripotency factor disengagement, with initial repression of Nanog and Esrrb, then Sox2 and finally Oct4, alongside step-wise activation of extraembryonic endoderm genes. Chromatin immunoprecipitation and subsequent high-throughput sequencing analysis shows Gata6 enrichment near both pluripotency and endoderm genes, suggesting that Gata6 functions as both a direct repressor and activator. Together this demonstrates that Gata6 is a versatile and potent reprogramming factor that can act alone to drive a cell fate switch from diverse cell types. Time-course microarray analysis of Gata6-mediated reprogramming from 12 to 144 hours of doxycycline treatment in mouse embryonic stem (mES) cells compared to uninduced mES cells, embryo-derived extraembryonic endoderm (XEN) cells and Sox7 overexpressing mES cells after 144 hours of doxycycline treatment.
Project description:Extraembryonic mesoderm (ExM) is one of the first cell types that emerges during embryogenesis and constitutes essential supportive tissues for the pregnancy. Primate ExM is known to form prior to gastrulation, unlike its murine counterpart which is derived from the primitive streak. Based on the embryonic morphology and the proximity of ExM to the extraembryonic endoderm (hypoblast), we hypothesised that ExM can be derived in vitro from the naïve extraembryonic endoderm (nEnd) cell line. We applied a mesoderm differentiation protocol, which has been reported to induce ExM from mouse epiblast stem cells, on human nEnd and analysed the transcriptome on day 0, 1, 2, 8 and 15.
Project description:Serine/threonine kinase 40 (Stk40) was previously identified as a direct target gene of pluripotency-associated transcription factor Oct4 and its overexpression could facilitate differentiation of mouse embryonic stem cells (mESCs) towards the extraembryonic endoderm. Stk40-/- mice are lethal at the perinatal stage, displaying multiple organ failures. However, the molecular mechanisms underlying the physiological functions of Stk40 remain elusive. Here, we report that Stk40 ablation compromises the mesoderm differentiation from mESCs in vitro and in embryos. Mechanistically, Stk40 interacts with both mammalian constitutive photomorphogenic protein 1 (Cop1) and c-Jun, promoting degradation of c-Jun. Consequently, Stk40 knockout leads to c-Jun protein accumulation, which, in turn, might suppress the Wnt signaling activity and impair the mesoderm differentiation process. Overall, this study reveals that Stk40, together with Cop1, represent a novel axis for modulating c-Jun protein levels within an appropriate range during mesoderm differentiation from mESCs. Our finding provides new insight into the molecular mechanism regulating c-Jun protein stability and may have potential for managing related cellular disorders.
Project description:H3K4me1 methyltransferases MLL3 (KMT2C) and MLL4 (KMT2D) are critical for enhancer activation, cell differentiation and development. However, roles of MLL3/4 enzymatic activities and MLL3/4-mediated enhancer H3K4me1 in these processes remain unclear. Here, we report that constitutive elimination of both MLL3 and MLL4 enzymatic activities prevents initiation of gastrulation and leads to early embryonic lethality in mice. However, selective elimination of MLL3/4 enzymatic activities in embryonic, but not extraembryonic, lineages leaves gastrulation largely intact. Consistently, embryonic stem cells (ESCs) lacking MLL3/4 enzymatic activities can differentiate towards the three embryonic germ layers but show aberrant differentiation to extraembryonic endoderm and trophectoderm. The failure in extraembryonic endoderm differentiation can be attributed to markedly reduced enhancer-binding of the lineage-determining transcription factor GATA6. Furthermore, we show that MLL3/4-catalyzed H3K4me1 is largely dispensable for enhancer activation during ESC differentiation. Together, our findings suggest a lineage-selective, but enhancer activation-independent, role of MLL3/4 methyltransferase activities in early embryonic development and ESC differentiation.