scholarly journals Depletion of Demethylase KDM6 Enhances Early Neuroectoderm Commitment of Human PSCs

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.

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.


2010 ◽  
Vol 88 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Guoliang Meng ◽  
Shiying Liu ◽  
Xiangyun Li ◽  
Roman Krawetz ◽  
Derrick E. Rancourt

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the blastocyst. Because of their ability to differentiate into a variety of cell types, human embryonic stem cells (hESCs) provide an unlimited source of cells for clinical medicine and have begun to be used in clinical trials. Presently, although several hundred hESC lines are available in the word, only few have been widely used in basic and applied research. More and more hESC lines with differing genetic backgrounds are required for establishing a bank of hESCs. Here, we report the first Canadian hESC lines to be generated from cryopreserved embryos and we discuss how we navigated through the Canadian regulatory process. The cryopreserved human zygotes used in this study were cultured to the blastocyst stage, and used to isolate ICM via microsurgery. Unlike previous microsurgery methods, which use specialized glass or steel needles, our method conveniently uses syringe needles for the isolation of ICM and subsequent hESC lines. ICM were cultured on MEF feeders in medium containing FBS or serum replacer (SR). Resulting outgrowths were isolated, cut into several cell clumps, and transferred onto fresh feeders. After more than 30 passages, the two hESC lines established using this method exhibited normal morphology, karyotype, and growth rate. Moreover, they stained positively for a variety of pluripotency markers and could be differentiated both in vitro and in vivo. Both cell lines could be maintained under a variety of culture conditions, including xeno-free conditions we have previously described. We suggest that this microsurgical approach may be conducive to deriving xeno-free hESC lines when outgrown on xeno-free human foreskin fibroblast feeders.


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.


2021 ◽  
pp. 21-37
Author(s):  
Jonathan Slack

‘Embryonic stem cells’ focuses on embryonic stem (ES) cells, which are grown in tissue culture from the inner cell mass of a mammalian blastocyst-stage embryo. Human ES cells offer a potential route to making the kinds of cells needed for cell therapy. ES cells were originally prepared from mouse embryos. Although somewhat different, cells grown from inner cell masses of human embryos share many properties with mouse ES cells, such as being able to grow without limit and to generate differentiated cell types. Mouse ES cells have so far been of greater practical importance than those of humans because they have enabled a substantial research industry based on the creation of genetically modified mice.


2009 ◽  
Vol 21 (1) ◽  
pp. 191
Author(s):  
V. J. Hall ◽  
J. Christensen ◽  
P. Maddox-Hyttel

Pluripotency in mice and human embryonic stem cells is regulated by a number of transcription factors, notably including Oct-4, Sox-2, and Nanog. However, in the pig, previous research indicates that Oct-4 protein and mRNA is not specifically localized to the inner cell mass (ICM) of the zona-intact (ZI) blastocyst. Levels of expression of Nanog mRNA, on the other hand, appear to be low in the ZI blastocyst, and protein has not been detected. Similarly, Sox-2 expression in the ZI blastocyst is relatively low and not specific to the ICM. In this study, we investigated the mRNA expression of Oct-4, Sox-2, and Nanog in D6/D7-derived ZI porcine in vivo-derived blastocysts compared with epiblasts mechanically isolated from hatched D10/D11 in vivo-derived blastocysts. We then investigated components involved in pathways important for regulating pluripotency, including JAK/STAT (i.e. gp130, LIFr), FGF (i.e. bFGF, FGFr1, FGFr2), and BMP (bmp4, smad4) signaling pathways and their downstream targets, stat3, c-myc, c-fos, by using RT-PCR. Sows were artificially inseminated, and embryos were flushed from uteri following slaughter. Single D6/D7 blastocysts (n = 3), single mechanically isolated D10/D11 epiblasts (n = 3), endometrium, and oviduct total RNA was isolated using the RNeasy Micro Kit (Qiagen, Valencia, CA, USA). Total RNA from the blastocysts and epiblasts was then amplified to form cDNA using the QuantiTect Whole Transcriptome kit (Qiagen). Positive control tissues (oviduct and endometrium) were reverse transcribed using the RevertAid First Strand cDNA synthesis kit (Fermentas, Burlington, Ontario, Canada). Primers were designed to span introns in highly homologous sequences to human mRNA. Primers were tested in both oviduct and endometrium tissue, and products were sequenced to confirm specificity. PCR was performed at 55°C for 35 cycles. Results indicate that D6/D7 blastocysts only expressed Oct-4 and not Nanog and Sox-2. In contrast, all 3 transcripts were expressed in D10/D11 epiblasts. The D10/D11 epiblasts also expressed LIFr, bFGF, FGFr1, FGFr2, bmp4, smad4, stat3, c-myc, and c-fos. The cytokine receptor gp130 was only weakly expressed in a single epiblast. In contrast, the earlier stage D6/D7 blastocysts failed to express these messengers with the exception of weak expression of gp130 in all 3 blastocysts, and only a single blastocyst expressed LIFr, smad4, c-myc, and c-fos. In conclusion, this study indicates that the ICM of the porcine D6/D7 ZI blastocyst has not developed pluripotency signaling as observed in mice and humans at this developmental stage. Furthermore, without expression of gp130, the JAK/STAT pathway is unlikely to play a role in regulating pluripotency in the epiblast. It is likely that the later stage epiblast may be more amenable for the derivation of porcine embryonic stem cells.


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.


2019 ◽  
Vol 1 (1) ◽  

Stem cells have the ability to go through various cell divisions and also maintain undifferentiated state. Stem cells are Embryonic (Pluripotent) and adult stem cells. Pluripotent stem cells give rise to all tissues such as ectoderm, mesoderm and endoderm. Embryonic stem cells isolated from inner cell mass of embryo blastocyst. Adult stem cells are also undifferentiated cells present in adult organisms and repair the tissue when damaged occurs but number in less. Adult stem cells are present in bone marrow, adipose tissue, blood and juvenile state umbilical cord and tissue of specific origin like liver, heart, intestine and neural tissue. Embryonic stem cells from blastocyst have the ethical problems and tumorogenecity. These can be identified by flow cytometry. There are wide range of stem cell markers which are useful in identifying them. Most of the pluripotent cell markers are common with tumor cell markers which throws a challenge for certainty.


Biology Open ◽  
2021 ◽  
Author(s):  
Yao Xiao ◽  
Froylan Sosa ◽  
Pablo J. Ross ◽  
Kenneth E. Diffenderfer ◽  
Peter J. Hansen

Bovine embryonic stem cells (ESC) have features associated with the primed pluripotent state including low expression of one of the core pluripotency transcription factors NANOG. It has been reported that NANOG expression can be upregulated in porcine ESC by treatment with activin A and the WNT agonist CHIR99021. Accordingly, it was tested whether expression of NANOG and another pluripotency factor SOX2 could be stimulated by activin A and the WNT agonist CHIR99021. Immunoreactive NANOG and SOX2 were analyzed for bovine ESC lines derived under conditions in which activin A and CHIR99021 were added singly or in combination. Activin A enhanced NANOG expression but also reduced SOX2 expression. CHIR99021 depressed expression of both NANOG and SOX2. In a second experiment, activin A enhanced blastocyst development while CHIR99021 treatment impaired blastocyst formation and reduced number of blastomeres. Activin A treatment decreased blastomeres in the blastocyst that were positive for either NANOG or SOX2 but increased those that were CDX2+ and that were GATA6+ outside the inner cell mass. CHIR99021 reduced SOX2+ and NANOG+ blastomeres without affecting the number or percent of blastomeres that were CDX2+ and GATA6+. Results indicate activation of activin A signaling stimulates NANOG expression during self-renewal of bovine ESC but suppresses cells expressing pluripotency markers in the blastocyst and increases cells expressing CDX2. Actions of activin A to promote blastocyst development may involve its role in promoting trophectoderm formation. Furthermore, results demonstrate the negative role of canonical WNT signaling in cattle for pluripotency marker expression in ESC and in formation of inner cell mass and epiblast during embryonic development.


2020 ◽  
Vol 24 (2) ◽  
pp. 91-98
Author(s):  
Na Rae Han ◽  
Song Baek ◽  
Hwa-Young Kim ◽  
Kwon Young Lee ◽  
Jung Im Yun ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document