scholarly journals Polycomb Repressive Complex 2 shields naïve human pluripotent cells from trophectoderm differentiation

2021 ◽  
Author(s):  
Banushree Kumar ◽  
Carmen Navarro ◽  
Nerges Winblad ◽  
John Paul Schell ◽  
Cheng Zhao ◽  
...  

The first lineage choice made in human embryo development separates trophectoderm from the inner cell mass, which proceeds to form the pluripotent epiblast and primitive endoderm. Trophectoderm on the other hand gives rise to the placenta. Naïve pluripotent stem cells are derived from the pluripotent epiblast of the blastocyst and offer possibilities to explore how lineage integrity is maintained. Here, we discover that Polycomb repressive complex 2 (PRC2) restricts an intrinsic capacity of naïve pluripotent stem cells to give rise to trophectoderm. Through quantitative epigenome profiling, we find that broad histone H3 lysine 27 trimethylation (H3K27me3) hypermethylation is a common feature of naïve pluripotency across species. We define a previously unappreciated, naïve-specific set of bivalent promoters, featuring PRC2-mediated H3K27me3 concomitant with H3K4me3. Naïve bivalency maintains key trophectoderm transcription factors in a transcriptionally poised state that is resolved to an active state upon depletion of H3K27me3 via inhibition of the enzymatic subunits of PRC2, EZH1/2. Conversely, primed human embryonic stem cells cannot be driven towards trophectoderm development via PRC2 inhibition. While naïve and primed hESCs share the majority of bivalent promoters, PRC2 contributes to the repression of largely non-overlapping subsets of these promoters in each state, hence H3K27me3-mediated repression provides a highly adaptive mechanism to restrict lineage potential during early human development.

2012 ◽  
Vol 24 (1) ◽  
pp. 220
Author(s):  
B. P. Telugu ◽  
T. Ezashi ◽  
A. Alexenko ◽  
S. Lee ◽  
R. S. Prather ◽  
...  

Authentic embryonic stem cells (ESC) may never have been successfully derived from the inner cell mass (ICM) of pig and other ungulates, despite over 25 years of effort. Recently, porcine induced pluripotent stem cells (piPSC) were generated by reprogramming somatic cells with a combination of four factors OCT4, SOX2, KLF4 and c-MYC (OSKM) delivered by lentiviral transduction. The established piPSC are analogous to FGF2-dependent human (h) ESC and murine “epiblast stem cells,” and are likely to advance swine as a model in biomedical research. Here, we report for the first time, the establishment of LIF-dependent, so called naïve type pluripotent stem cells (1) from the inner cell mass (ICM) of porcine blastocysts by up-regulating the expression of KLF4 and POU5F1; and (2) from umbilical cord mesenchyme (Wharton's jelly) by transduction with OSKM factors and subsequent culture in the presence of LIF-based medium with inhibitors that substitute for low endogenous expression of c-MYC and KLF4 and promote pluripotency. The 2 compounds that have been used in this study are, CHIR99021 (CH), which substitutes c-MYC by inhibiting GSK3B and activating WNT signalling and Kenpaullone (KP), which inhibits both GSK3B and CDK1 and supplants KLF4 function. The lentiviral vectors employed for introducing the re-programming genes were modified for doxycycline-mediated induction of expression (tet-on) and are ‘floxed’ for Cre-mediated recombination and removal of transgenes following complete reprogramming. Two LIF-dependent cell lines have been derived from the ICM cells of late d 5.5 in vitro produced blastocysts and four from umbilical cord mesenchyme recovered from fetuses at d 35 of pregnancy. The derived stem cell lines are alkaline phosphatase-positive, resemble mouse embryonic stem cells in colony morphology, cell cycle interval, transcriptome profile and expression of pluripotent markers, such as POU5F1, SOX2 and surface marker SSEA1. They are dependent on LIF signalling for maintenance of pluripotency, can be cultured over extended passage (>50) with no senescence. Of importance, the ICM-derived lines have been successful in their ability to form teratomas. The cells could be cultured in feeder free conditions on a synthetic matrix in the presence of chemically defined medium and can be coaxed to differentiate under xeno-free conditions. Currently, the piPSC lines are being investigated for their ability to give rise to teratomas and to produce a live offspring by nuclear transfer. Supported by Addgene Innovation Award, MO Life Sciences Board Grant 00022147 and NIH grant HD21896.


2017 ◽  
Vol 29 (1) ◽  
pp. 101 ◽  
Author(s):  
R. Michael Roberts ◽  
Ye Yuan ◽  
Toshihiko Ezashi

This short review describes some general features of the origins of the pluripotent inner cell mass and epiblast during the early development of eutherian mammals and the two kinds of embryonic stem cell (ESC), naïve and primed type, that have been produced from these structures. We point out that the derivation of pluripotent stem cells from domesticated species continues to be fraught with difficulties, most likely because the culture requirements of these cells are distinct from those of mouse and human ESCs. Generation of induced pluripotent stem cells (iPSCs) from the domesticated species has been more straightforward, although the majority of the iPSC lines remain dependent on the continued expression of one or more integrated reprogramming genes. Although hope for the potential usefulness of these cells in genetic modification of livestock and other domestic species has dimmed, ESCs and iPSCs remain our best source of self-renewing populations of pluripotent cells, with potential usefulness in preserving and propagating valuable animal breeds and making contributions to fields such as regenerative medicine, toxicology and even laboratory meat production.


Author(s):  
Yajing Meng ◽  
Tianzhe Zhang ◽  
Ran Zheng ◽  
Song Ding ◽  
Jie Yang ◽  
...  

Epigenetic modifications play a crucial role in neurogenesis, learning, and memory, but the study of their role in early neuroectoderm commitment from pluripotent inner cell mass is relatively lacking. Here we utilized the system of directed neuroectoderm differentiation from human embryonic stem cells and identified that KDM6B, an enzyme responsible to erase H3K27me3, was the most upregulated enzyme of histone methylation during neuroectoderm differentiation by transcriptome analysis. We then constructed KDM6B-null embryonic stem cells and found strikingly that the pluripotent stem cells with KDM6B knockout exhibited much higher neuroectoderm induction efficiency. Furthermore, we constructed a series of embryonic stem cell lines knocking out the other H3K27 demethylase KDM6A, and depleting both KDM6A and KDM6B, respectively. These cell lines together confirmed that KDM6 impeded early neuroectoderm commitment. By RNA-seq, we found that the expression levels of a panel of WNT genes were significantly affected upon depletion of KDM6. Importantly, the result that WNT agonist and antagonist could abolish the differential neuroectoderm induction due to manipulating KDM6 further demonstrated that WNT was the major downstream of KDM6 during early neural induction. Moreover, we found that the chemical GSK-J1, an inhibitor of KDM6, could enhance neuroectoderm induction from both embryonic stem cells and induced pluripotent stem cells. Taken together, our findings not only illustrated the important role of the histone methylation modifier KDM6 in early neurogenesis, providing insights into the precise epigenetic regulation in cell fate determination, but also showed that the inhibitor of KDM6 could facilitate neuroectoderm differentiation from human pluripotent stem cells.


2016 ◽  
Vol 8 ◽  
pp. GEG.S38093 ◽  
Author(s):  
Jifang Xiao ◽  
Daniel H. Mai ◽  
Liangqi Xie

The rodent naive pluripotent state is believed to represent the preimplantation inner cell mass state of the developing blastocyst and can derive self-renewing pluripotent embryonic stem cells (ESCs) in vitro. Nevertheless, human ESCs exhibit epigenetic, metabolic, and transcriptomic characteristics more akin to primed pluripotent stem cells (PSCs) derived from the postimplantation epiblast. Understanding the genetic and epigenetic mechanisms that constrain human ESCs in the primed state is crucial for the human naive pluripotent state resetting and numerous applications in regenerative medicine. In this review, we begin by defining the naive and primed states in the murine model and compare the epigenetic characteristics of those states to the human PSCs. We also examine the various reprogramming schemes to derive the human naive pluripotent state. Finally, we discuss future perspectives of studying and deriving the human naive PSCs in the context of cellular engineering and regenerative medicine.


2018 ◽  
Vol 373 (1750) ◽  
pp. 20170213 ◽  
Author(s):  
R. Abu-Dawud ◽  
N. Graffmann ◽  
S. Ferber ◽  
W. Wruck ◽  
J. Adjaye

Pluripotent stem cells (PSCs) lie at the heart of modern regenerative medicine due to their properties of unlimited self-renewal in vitro and their ability to differentiate into cell types representative of the three embryonic germ layers—mesoderm, ectoderm and endoderm. The derivation of induced PSCs bypasses ethical concerns associated with the use of human embryonic stem cells and also enables personalized cell-based therapies. To exploit their regenerative potential, it is essential to have a firm understanding of the molecular processes associated with their induction from somatic cells. This understanding serves two purposes: first, to enable efficient, reliable and cost-effective production of excellent quality induced PSCs and, second, to enable the derivation of safe, good manufacturing practice-grade transplantable donor cells. Here, we review the reprogramming process of somatic cells into induced PSCs and associated mechanisms with emphasis on self-renewal, epigenetic control, mitochondrial bioenergetics, sub-states of pluripotency, naive ground state, naive and primed. A meta-analysis identified genes expressed exclusively in the inner cell mass and in the naive but not in the primed pluripotent state. We propose these as additional biomarkers defining naive PSCs. This article is part of the theme issue ‘Designer human tissue: coming to a lab near you’.


Biology Open ◽  
2021 ◽  
Vol 10 (10) ◽  
Author(s):  
Viju Vijayan Pillai ◽  
Prasanthi P. Koganti ◽  
Tiffany G. Kei ◽  
Shailesh Gurung ◽  
W. Ronald Butler ◽  
...  

ABSTRACT Although derivation of naïve bovine embryonic stem cells is unachieved, the possibility for generation of bovine induced pluripotent stem cells (biPSCs) has been generally reported. However, attempts to sustain biPSCs by promoting self-renewal have not been successful. Methods established for maintaining murine and human induced pluripotent stem cells (iPSCs) do not support self-renewal of iPSCs for any bovid species. In this study, we examined methods to enhance complete reprogramming and concurrently investigated signaling relevant to pluripotency of the bovine blastocyst inner cell mass (ICM). First, we identified that forced expression of SV40 large T antigen together with the reprogramming genes (OCT4, SOX2, KLF4 and MYC) substantially enhanced the reprogramming efficacy of bovine fibroblasts to biPSCs. Second, we uncovered that TGFβ signaling is actively perturbed in the ICM. Inhibition of ALK4/5/7 to block TGFβ/activin/nodal signaling together with GSK3β and MEK1/2 supported robust in vitro self-renewal of naïve biPSCs with unvarying colony morphology, steady expansion, expected pluripotency gene expression and committed differentiation plasticity. Core similarities between biPSCs and stem cells of the 16-cell-stage bovine embryo indicated a stable ground state of pluripotency; this allowed us to reliably gain predictive understanding of signaling in bovine pluripotency using systems biology approaches. Beyond defining a high-fidelity platform for advancing biPSC-based biotechnologies that have not been previously practicable, these findings also represent a significant step towards understanding corollaries and divergent aspects of bovine pluripotency. This article has an associated First Person interview with the joint first authors of the paper.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Kimia Hosseini ◽  
Emilia Lekholm ◽  
Aikeremu Ahemaiti ◽  
Robert Fredriksson

Human embryonic stem cells (hESCs) are pluripotent cells, capable of differentiation into different cellular lineages given the opportunity. Derived from the inner cell mass of blastocysts in early embryonic development, the cell self-renewal ability makes them a great tool for regenerative medicine, and there are different protocols available for maintaining hESCs in their undifferentiated state. In addition, protocols for differentiation into functional human neural stem cells (hNSCs), which have the potential for further differentiation into various neural cell types, are available. However, many protocols are time-consuming and complex and do not always fit for purpose. In this study, we carefully combined, optimized, and developed protocols for differentiation of hESCs into adherent monolayer hNSCs over a short period of time, with the possibility of both expansion and freezing. Moreover, the method details further differentiation into neurons, cholinergic neurons, and glial cells in a simple, single step by step protocol. We performed immunocytochemistry, qPCR, and electrophysiology to examine the expression profile and characteristics of the cells to verify cell lineage. Using presented protocols, the creation of neuronal cultures, cholinergic neurons, and a mixed culture of astrocytes and oligodendrocytes can be completed within a three-week time period.


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