scholarly journals Embryonic diapause in mammals and dormancy in embryonic stem cells with the European roe deer as experimental model

2021 ◽  
Vol 33 (2) ◽  
pp. 76
Author(s):  
Vera A. van der Weijden ◽  
Anna B. Rüegg ◽  
Sandra M. Bernal-Ulloa ◽  
Susanne E. Ulbrich

In species displaying embryonic diapause, the developmental pace of the embryo is either temporarily and reversibly halted or largely reduced. Only limited knowledge on its regulation and the inhibition of cell proliferation extending pluripotency is available. In contrast with embryos from other diapausing species that reversibly halt during diapause, embryos of the roe deer Capreolus capreolus slowly proliferate over a period of 4–5 months to reach a diameter of approximately 4mm before elongation. The diapausing roe deer embryos present an interesting model species for research on preimplantation developmental progression. Based on our and other research, we summarise the available knowledge and indicate that the use of embryonic stem cells (ESCs) would help to increase our understanding of embryonic diapause. We report on known molecular mechanisms regulating embryonic diapause, as well as cellular dormancy of pluripotent cells. Further, we address the promising application of ESCs to study embryonic diapause, and highlight the current knowledge on the cellular microenvironment regulating embryonic diapause and cellular dormancy.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3174
Author(s):  
Alan F. Murray ◽  
Evangelos Delivopoulos

Neuronal patterning on microfabricated architectures has developed rapidly over the past few years, together with the emergence of soft biocompatible materials and tissue engineering scaffolds. Previously, we introduced a patterning technique based on serum and the biopolymer parylene-C, achieving highly compliant growth of primary neurons and astrocytes on different geometries. Here, we expanded this technique and illustrated that neuralized cells derived from mouse embryonic stem cells (mESCs) followed stripes of variable widths with conformity equal to or higher than that of primary neurons and astrocytes. Our results indicate the presence of undifferentiated mESCs, which also conformed to the underlying patterns to a high degree. This is an exciting and unexpected outcome, as molecular mechanisms governing cell and ECM protein interactions are different in stem cells and primary cells. Our study enables further investigations into the development and electrophysiology of differentiating patterned neural stem cells.


2002 ◽  
Vol 2 ◽  
pp. 1147-1166 ◽  
Author(s):  
Sally A. Moody ◽  
Hyun-Soo Je

The promise of stem cell therapy is expected to greatly benefit the treatment of neurodegenerative diseases. An underlying biological reason for the progressive functional losses associated with these diseases is the extremely low natural rate of self-repair in the nervous system. Although the mature CNS harbors a limited number of self-renewing stem cells, these make a significant contribution to only a few areas of brain. Therefore, it is particularly important to understand how to manipulate embryonic stem cells and adult neural stem cells so their descendants can repopulate and functionally repair damaged brain regions. A large knowledge base has been gathered about the normal processes of neural development. The time has come for this information to be applied to the problems of obtaining sufficient, neurally committed stem cells for clinical use. In this article we review the process of neural induction, by which the embryonic ectodermal cells are directed to form the neural plate, and the process of neural�fate stabilization, by which neural plate cells expand in number and consolidate their neural fate. We will present the current knowledge of the transcription factors and signaling molecules that are known to be involved in these processes. We will discuss how these factors may be relevant to manipulating embryonic stem cells to express a neural fate and to produce large numbers of neurally committed, yet undifferentiated, stem cells for transplantation therapies.


Blood ◽  
2006 ◽  
Vol 108 (5) ◽  
pp. 1515-1523 ◽  
Author(s):  
Kai-Hsin Chang ◽  
Angelique M. Nelson ◽  
Hua Cao ◽  
Linlin Wang ◽  
Betty Nakamoto ◽  
...  

Human embryonic stem cells are a promising tool to study events associated with the earliest ontogenetic stages of hematopoiesis. We describe the generation of erythroid cells from hES (H1) by subsequent processing of cells present at early and late stages of embryoid body (EB) differentiation. Kinetics of hematopoietic marker emergence suggest that CD45+ hematopoiesis peaks at late D14EB differentiation stages, although low-level CD45- erythroid differentiation can be seen before that stage. By morphologic criteria, hES-derived erythroid cells were of definitive type, but these cells both at mRNA and protein levels coexpressed high levels of embryonic (ϵ) and fetal (γ) globins, with little or no adult globin (β). This globin expression pattern was not altered by the presence or absence of fetal bovine serum, vascular endothelial growth factor, Flt3-L, or coculture with OP-9 during erythroid differentiation and was not culture time dependent. The coexpression of both embryonic and fetal globins by definitive-type erythroid cells does not faithfully mimic either yolk sac embryonic or their fetal liver counterparts. Nevertheless, the high frequency of erythroid cells coexpressing embryonic and fetal globin generated from embryonic stem cells can serve as an invaluable tool to further explore molecular mechanisms.


2019 ◽  
Author(s):  
Arindam Ghosh ◽  
Anup Som

Insight into the key genes of pluripotency in human and their interrelationships is necessary for understanding the underlying mechanism of pluripotency and hence their successful application in regenerative medicine. The recent advances in transcriptomics technologies have created new opportunities to decipher the genes involved in pluripotency, genetic network that governs the unique properties of embryonic stem cells and lineage differentiation mechanisms in a deeper scale. There are a large number of experimental studies on human embryonic stem cells (hESCs) being routinely conducted for unfolding the underlying biology of embryogenesis and their clinical prospects. However, the outcome of these studies often lacks consensus due to differences in samples, experimental techniques and/or analysis protocols. A universal stemness gene list is still lacking. In this quest, we compared transcriptomic profiles of pluripotent and non-pluripotent samples from diverse cell lines/types generated through RNA-sequencing (RNA-seq). We used a uniform pipeline for the analysis of raw RNA-seq data in order to reduce the amount of variation. Our analysis revealed a consensus set of 498 pluripotency-associated genes and 432 genes as potential pluripotent cell differentiation markers. Furthermore, we predicted 32 genes as "pluripotency critical genes". Reconstruction and analysis of co-expression networks further highlighted the importance of these genes. Gene ontology (GO) and pathway enrichment analysis, StemChecker and literature survey confirmed the involvement of the genes in the induction and maintenance of pluripotency, though more experimental studies are required for understanding their molecular mechanisms in human.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ju Young Kim ◽  
Dong Hun Lee ◽  
Joo Kyung Kim ◽  
Hong Seo Choi ◽  
Bhakti Dwivedi ◽  
...  

AbstractPrevious studies including ours have demonstrated a critical function of the transcription factor ETV2 (ets variant 2; also known as ER71) in determining the fate of cardiovascular lineage development. However, the underlying mechanisms of ETV2 function remain largely unknown. In this study, we demonstrated the novel function of the miR (micro RNA)-126-MAPK (mitogen-activated protein kinase) pathway in ETV2-mediated FLK1 (fetal liver kinase 1; also known as VEGFR2)+ cell generation from the mouse embryonic stem cells (mESCs). By performing a series of experiments including miRNA sequencing and ChIP (chromatin immunoprecipitation)-PCR, we found that miR-126 is directly induced by ETV2. Further, we identified that miR-126 can positively regulate the generation of FLK1+ cells by activating the MAPK pathway through targeting SPRED1 (sprouty-related EVH1 domain containing 1). Further, we showed evidence that JUN/FOS activate the enhancer region of FLK1 through AP1 (activator protein 1) binding sequences. Our findings provide insight into the novel molecular mechanisms of ETV2 function in regulating cardiovascular lineage development from mESCs.


2021 ◽  
Author(s):  
Wei Fan ◽  
Shuang Tang ◽  
Xiaojuan Fan ◽  
Yi Fang ◽  
Xiaojiang Xu ◽  
...  

AbstractSphingolipids are important structural components of cell membranes and prominent signaling molecules controlling cell growth, differentiation, and apoptosis. Sphingolipids are particularly abundant in the brain, and defects in sphingolipid degradation are associated with several human neurodegenerative diseases. However, molecular mechanisms governing sphingolipid metabolism remain unclear. Here we report that sphingolipid degradation is under transcriptional control of SIRT1, a highly conserved mammalian NAD+-dependent protein deacetylase, in mouse embryonic stem cells (mESCs). Deletion of SIRT1 results in accumulation of sphingomyelin in mESCs, primarily due to reduction of SMPDL3B, a GPI-anchored plasma membrane bound sphingomyelin phosphodiesterase. Mechanistically, SIRT1 regulates transcription of Smpdl3b through c-Myc. Functionally, SIRT1 deficiency-induced accumulation of sphingomyelin increases membrane fluidity and impairs neural differentiation in vitro and in vivo. Our findings discover a key regulatory mechanism for sphingolipid homeostasis and neural differentiation, further imply that pharmacological manipulation of SIRT1-mediated sphingomyelin degradation might be beneficial for treatment of human neurological diseases.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Wei Fan ◽  
Shuang Tang ◽  
Xiaojuan Fan ◽  
Yi Fang ◽  
Xiaojiang Xu ◽  
...  

Sphingolipids are important structural components of cell membranes and prominent signaling molecules controlling cell growth, differentiation, and apoptosis. Sphingolipids are particularly abundant in the brain, and defects in sphingolipid degradation are associated with several human neurodegenerative diseases. However, molecular mechanisms governing sphingolipid metabolism remain unclear. Here we report that sphingolipid degradation is under transcriptional control of SIRT1, a highly conserved mammalian NAD+-dependent protein deacetylase, in mouse embryonic stem cells (mESCs). Deletion of SIRT1 results in accumulation of sphingomyelin in mESCs, primarily due to reduction of SMPDL3B, a GPI-anchored plasma membrane bound sphingomyelin phosphodiesterase. Mechanistically, SIRT1 regulates transcription of Smpdl3b through c-Myc. Functionally, SIRT1 deficiency-induced accumulation of sphingomyelin increases membrane fluidity and impairs neural differentiation in vitro and in vivo. Our findings discover a key regulatory mechanism for sphingolipid homeostasis and neural differentiation, further imply that pharmacological manipulation of SIRT1-mediated sphingomyelin degradation might be beneficial for treatment of human neurological diseases.


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