scholarly journals Early development of the porcine embryo: the importance of cell signalling in development of pluripotent cell lines

2013 ◽  
Vol 25 (1) ◽  
pp. 94 ◽  
Author(s):  
Vanessa Jane Hall

Understanding the cell signalling events that govern cell renewal in porcine pluripotent cells may help improve culture conditions and allow for establishment of bona fide porcine embryonic stem cells (pESC) and stable porcine induced pluripotent stem cells (piPSC). This review investigates cell signalling in the porcine preimplantation embryo containing either the inner cell mass or epiblast, with particular emphasis on fibroblast growth factor, SMAD, WNT and Janus tyrosine kinases/signal transducers and activators of transcription signalling. It is clear that key differences exist in the cell signalling events that govern pluripotency in this species compared with similar embryonic stages in mouse and human. The fact that bona fide pESC have still not been produced and that piPSC cannot survive in culture following the silencing or downregulation of the reprogramming transgenes suggest that culture conditions are not optimal. Unravelling the factor/s that regulate pluripotency in porcine embryos will pave the way for future establishment of stable pluripotent stem cell lines.

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.


2005 ◽  
Vol 17 (2) ◽  
pp. 125 ◽  
Author(s):  
Wilfried A. Kues ◽  
Joseph W. Carnwath ◽  
Heiner Niemann

Pluripotent embryonic stem cells (ESCs) from the inner cell mass of early murine and human embryos exhibit extensive self-renewal in culture and maintain their ability to differentiate into all cell lineages. These features make ESCs a suitable candidate for cell-replacement therapy. However, the use of early embryos has provoked considerable public debate based on ethical considerations. From this standpoint, stem cells derived from adult tissues are a more easily accepted alternative. Recent results suggest that adult stem cells have a broader range of potency than imagined initially. Although some claims have been called into question by the discovery that fusion between the stem cells and differentiated cells can occur spontaneously, in other cases somatic stem cells have been induced to commit to various lineages by the extra- or intracellular environment. Recent data from our laboratory suggest that changes in culture conditions can expand a subpopulation of cells with a pluripotent phenotype from primary fibroblast cultures. The present paper critically reviews recent data on the potency of somatic stem cells, methods to modify the potency of somatic cells and implications for cell-based therapies.


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.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Delia Alba Soto ◽  
Micaela Navarro ◽  
Canbin Zheng ◽  
Michelle Margaret Halstead ◽  
Chuan Zhou ◽  
...  

AbstractBovine embryonic stem cells (bESCs) extend the lifespan of the transient pluripotent bovine inner cell mass in vitro. After years of research, derivation of stable bESCs was only recently reported. Although successful, bESC culture relies on complex culture conditions that require a custom-made base medium and mouse embryonic fibroblasts (MEF) feeders, limiting the widespread use of bESCs. We report here simplified bESC culture conditions based on replacing custom base medium with a commercially available alternative and eliminating the need for MEF feeders by using a chemically-defined substrate. bESC lines were cultured and derived using a base medium consisting of N2B27 supplements and 1% BSA (NBFR-bESCs). Newly derived bESC lines were easy to establish, simple to propagate and stable after long-term culture. These cells expressed pluripotency markers and actively proliferated for more than 35 passages while maintaining normal karyotype and the ability to differentiate into derivatives of all three germ lineages in embryoid bodies and teratomas. In addition, NBFR-bESCs grew for multiple passages in a feeder-free culture system based on vitronectin and Activin A medium supplementation while maintaining pluripotency. Simplified conditions will facilitate the use of bESCs for gene editing applications and pluripotency and lineage commitment studies.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Lucia Marucci

Mouse embryonic stem cells (mESCs), derived from the inner cell mass of the blastocyst, are pluripotent stem cells having self-renewal capability and the potential of differentiating into every cell type under the appropriate culture conditions. An increasing number of reports have been published to uncover the molecular mechanisms that orchestrate pluripotency and cell fate specification using combined computational and experimental methodologies. Here, we review recent systems biology approaches to describe the causes and functions of gene expression heterogeneity and complex temporal dynamics of pluripotency markers in mESCs under uniform culture conditions. In particular, we focus on the dynamics of Nanog, a key regulator of the core pluripotency network and of mESC fate. We summarize the strengths and limitations of different experimental and modeling approaches and discuss how various strategies could be used.


2017 ◽  
Vol 4 (S) ◽  
pp. 147
Author(s):  
Ho Thi-Kim Ngan ◽  
Nguyen Van Thuan ◽  
Hong-Thuy Bui

Parthenogenesis is a process in which zygotes are produced without sperm presence. Due to lack of paternal genes, parthenogenetic embryos cannot develop to full-term; however, these embryos show a great potential to generate histocompatible stem cells (parthenogenetic embryonic stem – pES cells) for transplantation. In this research, parthenogenetic activation in the mouse was carried out using strontium chloride (SrCl2) combined with cytochalasin B (CB). The rate of embryo development, blastocyst quality and expression of acetylation of histone H4 lysine 12 (H4K12Ac) were investigated, while parthenogenetic blastocysts were used to establish pES cells. The results showed that rate of in vitro blastulation of parthenogenetic embryos was lower than that of fertilized ones (45.1% vs 98.0%, respectively). In addition, blastocysts developed from parthenogenetic embryos also expressed lower quality, which was demonstrated by lower total cell number. Moreover, H4K12Ac expression significantly decreased in the inner cell mass (ICM) of parthenogenetic blastocysts compared to fertilized ones, indicating a possible reason for lower blastocyst quality. Following embryo collection and activation, two ES cell lines – fertilized (fES) and pES cell lines have been successfully established and maintained long term in vitro. To sum up, differences in blastocyst quality and H4K12Ac expression in ICM cells of blastocyst may contribute to aberrant developmental and embryonic stem cell formation in parthenogenetic embryos.


2011 ◽  
Vol 23 (1) ◽  
pp. 246
Author(s):  
S. H. Jeong ◽  
H. S. Kim ◽  
H. Lee ◽  
K. J. Uh ◽  
S. H. Hyun ◽  
...  

Bovine transgenic embryonic stem (ES) cells have not been reported yet because it seems that the derivation methods and the culture conditions for the inner cell mass are neither consistent nor optimized. Isolation of inner cell mass and primary culture of ES colonies is a critical step toward the establishment of authentic bovine ES cell lines. Herein, we reconstructed somatic cell nuclear transferred (SCNT) bovine blastocysts carrying a vector expressing the human INF-α gene, and isolated inner cell masses to derive transgenic bovine embryonic stem cells. In addition, we added 2 inhibitors, inhibition (2i system) of the mitogen-activated protein kinase (Erk1/2) cascade, PD0325901(3 Î1/4M), and of glycogen synthase kinase 3, CHIR99021 (1 Î1/4M), in the inner cell mass primary culture to check reliability of the 2i system for bovine ES culture. The 2 inhibitors made the morphology of colonies more intact, and primary colonies were better maintained in early passages. However, there were no significant effects on the attachment rate and maintenance in late passages (percent of percent over 3 passages: 2i system, 21/38 (55.3%); control, 22/42 (33.3%); P < 0.05). Inner cell masses were isolated mechanically and subcultured by an enzymatic in primary inner cell mass culture. Massive growth of trophoblast cells appears to inhibit inner cell mass growth, so hatching and hatched blastocysts were cut with a needle to remove trophoblast cells. Poor quality blastocysts were attached by the whole seeding method, and the margin trophoblast cells were consecutively removed in early passages. Established bovine ES cells express alkaline phosphatase, Oct-4, SSEA1, SSEA4, Tra-1–60, and Tra-1–81. We confirmed pluripotent gene expression of bovine ES like cells; Oct-4, SSEA1, and Rex 1 were positive, but trophoblast marker CDX2 was negative. This study shows that the 2i system is a reasonable method for use during inner cell mass culture in early passages. We established 6 transgenic nuclear transfer bovine ES cell lines with the 2i system and 4 in vitro fertilized bovine ES cell lines (all were over 10 passages).


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.


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