Tyrosine kinase signalling in embryonic stem cells

2008 ◽  
Vol 115 (2) ◽  
pp. 43-55 ◽  
Author(s):  
Cecilia Annerén

Pluripotent ES (embryonic stem) cells can be expanded in culture and induced to differentiate into a wide range of cell types. Self-renewal of ES cells involves proliferation with concomitant suppression of differentiation. Some critical and conserved pathways regulating self-renewal in both human and mouse ES cells have been identified, but there is also evidence suggesting significant species differences. Cytoplasmic and receptor tyrosine kinases play important roles in proliferation, survival, self-renewal and differentiation in stem, progenitor and adult cells. The present review focuses on the role of tyrosine kinase signalling for maintenance of the undifferentiated state, proliferation, survival and early differentiation of ES cells.

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 (9) ◽  
pp. 100
Author(s):  
M. B. Morris ◽  
N. Hamra ◽  
A. C. Lonic ◽  
F. Felquer

The phenotypic status of embryonic stem (ES) cells is controlled in part by signalling pathways which translate inputs mediated by extracellular molecules. An important extracellular protagonist in mouse ES cells is LIF (leukaemia inhibitory factor) which interacts with the gp130–LIFR receptor complex to activate a number of downstream signalling pathways, including the STAT3, MEK/ERK and PI3K/Akt. These pathways, together with others, interact in complex and sometimes competing ways to generate the well-known characteristics of mouse ES cells of self-renewal, high rates of proliferation, and pluripotence. The addition of a second molecule, L-proline, to the extracellular environment alters the pluripotent status of mouse ES cells, converting them to a second pluripotent population equivalent to the primitive ectoderm of the pre-gastrulating embryo. This conversion, from ES cells to primitive ectoderm-like cells, primes the latter for directed differentiation to specific cell types (1). Here we show, using inhibitor studies and kinome array analysis, that this small molecule appears to work by (i) changing the balance in activity of signalling pathways already stimulated by LIF and (ii) activating additional signalling pathways. Specifically, L-proline rapidly further activates the LIF-stimulated MEK/ERK pathway, tipping the balance in favour of primitive-ectoderm formation and away from ES-cell self-renewal sustained by LIF-mediated activation of the STAT3 pathway. In addition, L-proline rapidly stimulates other pathways including p38, mTOR and PI3K/Akt each of which contributes, to a greater or lesser extent, to the conversion to primitive ectoderm-like cells. These results indicate that (i) L-proline acts in novel ways to stimulate embryo-like developmental progression in ES cells and (ii) through the addition of small, nontoxic activators and inhibitors of signalling pathways, the differentiation of pluripotent ES cells might be controlled sufficiently well for the homogeneous production of specific cell types suitable for use in animal models of human disease.


2012 ◽  
Vol 302 (3) ◽  
pp. C494-C504 ◽  
Author(s):  
José A. Rodríguez-Gómez ◽  
Konstantín L. Levitsky ◽  
José López-Barneo

Ion channels participate in cell homeostasis and are involved in the regulation of proliferation and differentiation in several cell types; however, their presence and function in embryonic stem (ES) cells are poorly studied. We have investigated the existence of voltage-dependent inward currents in mouse ES cells and their ability to modulate proliferation and self-renewal. Patch-clamped ES cells had inactivating tetrodotoxin (TTX)-sensitive Na+ currents as well as transient Ca2+ currents abolished by the external application of Ni2+. Biophysical and pharmacological data indicated that the Ca2+ current is predominantly mediated by T-type (Cav3.2) channels. The number of cells expressing T-type channels and Cav3.2 mRNA levels increased at the G1/S transition of the cell cycle. TTX had no effect on ES cell proliferation. However, blockade of T-type Ca2+ currents with Ni2+ induced a decrease in proliferation and alkaline phosphatase positive colonies as well as reduced expression of Oct3/4 and Nanog, all indicative of loss in self-renewal capacity. Decreased alkaline phosphatase and Oct3/4 expression were also observed in cells subjected to small interfering RNA-induced knockdown for T-type (Cav3.2) Ca2+ channels, thus partially recapitulating the pharmacological effects on self-renewal. These results indicate that Cav3.2 channel expression in ES cells is modulated along the cell cycle being induced at late G1 phase. They also suggest that these channels are involved in the maintenance of the undifferentiated state of mouse ES cells. We propose that Ca2+ entry mediated by Cav3.2 channels might be one of the intracellular signals that participate in the complex network responsible for ES cell self-renewal.


2012 ◽  
Vol 529-530 ◽  
pp. 385-390
Author(s):  
Koichi Imai ◽  
Fumio Watari ◽  
Kazuaki Nakamura ◽  
Akito Tanoue

The risks of nanomaterials for future generations should be elucidated. Thus, it is important to establish an experimental method to accurately examine embryotoxicity. We have conducted anin vitroembryotoxicity test with mouse ES cells to examine the embryotoxicities of various nanomaterials. In this study, the C60 fullerene did not influence the differentiation of ES-D3 cells and "non embryotoxicity". In the future, the biological safety should be comprehensively examined by improving dispersion in medium.


Author(s):  
Mikael C. O. Englund ◽  
Christopher L. R. Barratt

Ever since the first human embryonic stem cells (hES) were successfully derived and propagated in 1998 (1), an obvious topic of discussion has been the development of novel therapies based on stem cell technology for a number of diseases and conditions. Targets could include type 1 diabetes, Alzheimer’s disease, spinal cord injury, and Parkinson’s disease to name a few. hES cells can also be used for tissue engineering, to replace for example bone and cartilage, and for drug discovery. Exciting proof of principal experiments in animals demonstrate the clinical potential in this field. For example, in a rat model of Parkinson’s disease, dopamine neural grafts derived from mouse Es cells showed long-term survival, the production of dopamine and, importantly, persistent improvements in movement behaviour (2). The promises of these potential treatments is enormous. However, there are many hurdles to overcome before a therapy based on stem cells is a clinical reality. We outline (A) the variety of methods to derive hES cells including somatic cell nuclear transfer (SCNT) and describe the challenges and possible avenues of further use; (B) discuss the development of clinical grade hES cells and their use in the drug discovery process; and (C) alternative strategies to patient specific therapy including induced adult pluripotent stem cells (iPS cells).


2016 ◽  
Vol 113 (19) ◽  
pp. E2598-E2607 ◽  
Author(s):  
Shinichiro Yabe ◽  
Andrei P. Alexenko ◽  
Mitsuyoshi Amita ◽  
Ying Yang ◽  
Danny J. Schust ◽  
...  

Human embryonic stem cells (ESCs) readily commit to the trophoblast lineage after exposure to bone morphogenetic protein-4 (BMP-4) and two small compounds, an activin A signaling inhibitor and a FGF2 signaling inhibitor (BMP4/A83-01/PD173074; BAP treatment). During differentiation, areas emerge within the colonies with the biochemical and morphological features of syncytiotrophoblast (STB). Relatively pure fractions of mononucleated cytotrophoblast (CTB) and larger syncytial sheets displaying the expected markers of STB can be obtained by differential filtration of dispersed colonies through nylon strainers. RNA-seq analysis of these fractions has allowed them to be compared with cytotrophoblasts isolated from term placentas before and after such cells had formed syncytia. Although it is clear from extensive gene marker analysis that both ESC- and placenta-derived syncytial cells are trophoblast, each with the potential to transport a wide range of solutes and synthesize placental hormones, their transcriptome profiles are sufficiently dissimilar to suggest that the two cell types have distinct pedigrees and represent functionally different kinds of STB. We propose that the STB generated from human ESCs represents the primitive syncytium encountered in early pregnancy soon after the human trophoblast invades into the uterine wall.


2001 ◽  
Vol 13 (8) ◽  
pp. 523 ◽  
Author(s):  
Alan O. Trounson

Human embryonic stem cells lines can be derived from human blastocysts at high efficiency (>50%) by immunosurgical isolation of the inner cell mass and culture on embryonic fibroblast cell lines. These cells will spontaneously differentiate into all the primary embryonic lineages in vitro and in vivo, but they are unable to form an integrated embryo or body plan by themselves or when combined with trophectoderm cells. They may be directed into a number of specific cell types and this enrichment process requires specific growth factors, cell-surface molecules, matrix molecules and secreted products of other cell types. Embryonic stem (ES) cells are immortal and represent a major potential for cell therapies for regenerative medicine. Their use in transplantation may depend on the formation of a large bank of suitable human leucocyte antigen (HLA) types or the genetic erasure of their HLA expression. Successful transplantation may also require induction of tolerance in recipients and ongoing immune suppression. Although it is possible to customize ES cells by therapeutic cloning or cytoplasmic transfer, it would appear unlikely that these strategies will be used extensively for producing ES cells compatible for transplantation. Embryonic stem cell research may deliver a new pathway for regenerative medicine.


2007 ◽  
Vol 18 (4) ◽  
pp. 1348-1358 ◽  
Author(s):  
Linda Shushan Lim ◽  
Yuin-Han Loh ◽  
Weiwei Zhang ◽  
Yixun Li ◽  
Xi Chen ◽  
...  

Embryonic stem (ES) cell pluripotency is dependent upon sustained expression of the key transcriptional regulators Oct4, Nanog, and Sox2. Dissection of the regulatory networks downstream of these transcription factors has provided critical insight into the molecular mechanisms that regulate ES cell pluripotency and early differentiation. Here we describe a role for Zic3, a member of the Gli family of zinc finger transcription factors, in the maintenance of pluripotency in ES cells. We show that Zic3 is expressed in ES cells and that this expression is repressed upon differentiation. The expression of Zic3 in pluripotent ES cells is also directly regulated by Oct4, Sox2, and Nanog. Targeted repression of Zic3 in human and mouse ES cells by RNA interference–induced expression of several markers of the endodermal lineage. Notably, the expression of Nanog, a key pluripotency regulator and repressor of extraembryonic endoderm specification in ES cells, was significantly reduced in Zic3 knockdown cells. This suggests that Zic3 may prevent endodermal marker expression through Nanog-regulated pathways. Thus our results extend the ES cell transcriptional network beyond Oct4, Nanog, and Sox2, and further establish that Zic3 plays an important role in the maintenance of pluripotency by preventing endodermal lineage specification in embryonic stem cells.


Author(s):  
Vijay V. Vishnu ◽  
Bh. Muralikrishna ◽  
Archana Verma ◽  
Sanjeev Chavan Nayak ◽  
Divya Tej Sowpati ◽  
...  

SummaryC3G (RAPGEF1), engaged in multiple signaling pathways, is essential for the early development of the mouse. In this study, we have examined its role in mouse embryonic stem cell self-renewal and differentiation. C3G null cells generated by CRISPR mediated knock-in of a targeting vector exhibited enhanced clonogenicity and long-term self-renewal. They did not differentiate in response to LIF withdrawal when compared to the wild type ES cells and were defective for lineage commitment upon teratoma formation in vivo. Gene expression analysis of C3G KO cells showed misregulated expression of a large number of genes compared with WT cells. They express higher levels of self-renewal factors like KLF4 and ESRRB and show high STAT3 activity, and very low ERK activity compared to WT cells. Reintroduction of C3G expression in a KO line partially reverted expression of ESRRB, and KLF4, and ERK activity similar to that seen in WT cells. The expression of self-renewal factors was persistent for a longer time, and induction of lineage-specific markers was not seen when C3G KO cells were induced to form embryoid bodies. C3G KO cells showed poor adhesion and significantly reduced levels of pFAK, pPaxillin, and Integrin-β1, in addition to downregulation of the cluster of genes involved in cell adhesion, compared to WT cells. Our results show that C3G is essential for the regulation of STAT3, ERK, and adhesion signaling, to maintain pluripotency of mouse embryonic stem cells and enable their lineage commitment for differentiation. Graphical abstract


Author(s):  
Dhruv Raina ◽  
Angel Stanoev ◽  
Azra Bahadori ◽  
Michelle Protzek ◽  
Aneta Koseska ◽  
...  

AbstractDuring embryonic development and tissue homeostasis, reproducible proportions of differentiated cell types need to be specified from homogeneous precursor cell populations. How this is achieved despite uncertainty in initial conditions in the precursor cells, and how proportions are re-established upon perturbations in the developing tissue is not known. Here we report the differentiation of robust proportions of epiblast- and primitive endoderm-like cells from a wide range of experimentally controlled initial conditions in mouse embryonic stem cells. We demonstrate both experimentally and theoretically that recursive cell-cell communication via FGF4 establishes a population-based mechanism that generates and maintains robust proportions of differentiated cell types. Furthermore, we show that cell-cell communication re-establishes heterogeneous cell identities following the isolation of one cell type. The generation and maintenance of robust cell fate proportions is a new function for FGF signaling that may extend to other cell fate decisions.


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