The effect of dual inhibition of Ras–MEK–ERK and GSK3β pathways on development of in vitro cultured rabbit embryos

Zygote ◽  
2020 ◽  
Vol 28 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Babett Bontovics ◽  
Pouneh Maraghechi ◽  
Bence Lázár ◽  
Mahek Anand ◽  
Kinga Németh ◽  
...  

SummaryDual inhibition (2i) of Ras–MEK–ERK and GSK3β pathways enables the derivation of embryo stem cells (ESCs) from refractory mouse strains and, for permissive strains, allows ESC derivation with no external protein factor stimuli involvement. In addition, blocking of ERK signalling in 8-cell-stage mouse embryos leads to ablation of GATA4/6 expression in hypoblasts, suggesting fibroblast growth factor (FGF) dependence of hypoblast formation in the mouse. In human, bovine or porcine embryos, the hypoblast remains unaffected or displays slight-to-moderate reduction in cell number. In this study, we demonstrated that segregation of the hypoblast and the epiblast in rabbit embryos is FGF independent and 2i treatment elicits only a limited reinforcement in favour of OCT4-positive epiblast populations against the GATA4-/6-positive hypoblast population. It has been previously shown that TGFβ/Activin A inhibition overcomes the pervasive differentiation and inhomogeneity of rat iPSCs, rat ESCs and human iPSCs while prompting them to acquire naïve properties. However, TGFβ/Activin A inhibition, alone or together with Rho-associated, coiled-coil containing protein kinase (ROCK) inhibition, was not compatible with the viability of rabbit embryos according to the ultrastructural analysis of preimplantation rabbit embryos by electron microscopy. In rabbit models ovulation upon mating allows the precise timing of progression of the pregnancy. It produces several embryos of the desired stage in one pregnancy and a relatively short gestation period, making the rabbit embryo a suitable model to discover the cellular functions and mechanisms of maintenance of pluripotency in embryonic cells and the embryo-derived stem cells of other mammals.

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.


Zygote ◽  
2005 ◽  
Vol 13 (1) ◽  
pp. 39-44 ◽  
Author(s):  
P. Chrenek ◽  
A.V. Makarevich

The objective of this study was to compare in vitro developmental capacity of zona-free aggregated rabbit chimeric embryos and the allocation of EGFP (enhanced green fluorescence protein) gene expression to the inner cell mass (ICM). We produced chimeric embryos by synchronous aggregation of zona-free blastomeres from embryonic cell nuclear transfer (EMB-NT) or somatic cell nuclear transfer (SC-NT) and blastomeres from normal zona-free embryos (N) at the 16-cell stage. In the control group, transgenic (TR) and normal zona-free embryos were used to produce chimeric embryos (TR<>N). EMB-NT embryos were produced by fusion of enucleated oocytes with embryonic cells, which were derived from 32-cell stage transgenic embryos bearing the EGFP gene. The SC-NT embryos were produced by fusing enucleated oocytes with cumulus cells, which were derived from homozygotes transgenic for the EGFP gene female oocytes at 16 h post-coitum. Nuclei of transgenic blastomeres emitted a green signal under fluorescence microscopy. Zona-free EMB-NT or zona-free SC-NT rabbit embryos, both with EGFP fluorescence, as well as TR and zona-free rabbit embryos with no fluorescence (EMB-NT<>N, SC-NT<>N, TR<>N) were aggregated on day 2.5 and evaluated on day 5. The proportion of EMB-NT<>N embryos that developed to the blastocyst stage was significantly higher compared with SC-NT derived cells (p<0.05), but significantly lower than in TR<>N chimeric blastocysts (p<0.001). Similarly, a higher proportion (p<0.001) of EGFP-positive cells allocated to ICM of chimeric blastocysts was revealed in TR<>N chimeras (55%), compared with EMB-NT<>N (35%) and SC-NT<>N (21%). Our results indicate that synchronous chimeric embryos reconstructed from TR embryos were better able to develop and colonize the ICM area than EMB-NT and SC-NT embryos. In this study we have demonstrated for the first time that rabbit NT-derived embryos are able to develop into chimeric blastocysts and participate in the ICM area.


2021 ◽  
Vol 22 (9) ◽  
pp. 4334
Author(s):  
Katrina Albert ◽  
Jonna Niskanen ◽  
Sara Kälvälä ◽  
Šárka Lehtonen

Induced pluripotent stem cells (iPSCs) are a self-renewable pool of cells derived from an organism’s somatic cells. These can then be programmed to other cell types, including neurons. Use of iPSCs in research has been two-fold as they have been used for human disease modelling as well as for the possibility to generate new therapies. Particularly in complex human diseases, such as neurodegenerative diseases, iPSCs can give advantages over traditional animal models in that they more accurately represent the human genome. Additionally, patient-derived cells can be modified using gene editing technology and further transplanted to the brain. Glial cells have recently become important avenues of research in the field of neurodegenerative diseases, for example, in Alzheimer’s disease and Parkinson’s disease. This review focuses on using glial cells (astrocytes, microglia, and oligodendrocytes) derived from human iPSCs in order to give a better understanding of how these cells contribute to neurodegenerative disease pathology. Using glia iPSCs in in vitro cell culture, cerebral organoids, and intracranial transplantation may give us future insight into both more accurate models and disease-modifying therapies.


2011 ◽  
Vol 151 (4) ◽  
pp. 502-505 ◽  
Author(s):  
R. A. Semechkin ◽  
T. V. Abramihina ◽  
D. A. Isaev
Keyword(s):  

2002 ◽  
Vol 80 (7) ◽  
pp. 618-624 ◽  
Author(s):  
P Jacquet ◽  
J Buset ◽  
J Vankerkom ◽  
S Baatout ◽  
L de Saint-Georges ◽  
...  

PCC (premature chromosome condensation) can be used for visualizing and scoring damage induced by radiation in the chromatin of cells undergoing a G1 or G2 arrest. A method involving the fusion of irradiated single embryonic cells with single MI oocytes was used to induce PCC in mouse zygotes of the BALB/c strain, which suffer a drastic G2 arrest after X-irradiation (dose used 2.5 Gy). Other G2-arrested embryos were exposed in vitro to the phosphatase inhibitor calyculin A. Both methods furnished excellent chromosome preparations of the G2-arrested embryos. The mean number of chromosome fragments did not change significantly during G2 arrest, suggesting that zygotes of this strain are unable to repair DNA damage leading to such aberrations. Forty to fifty percent of the irradiated embryos were unable to cleave after G2 arrest and remained blocked at the one-cell stage for a few days before dying. PCC preparations obtained from such embryos suggested that about 30% of them had undergone a late mitosis not followed by cytokinesis and had entered a new DNA synthesis. These results are discussed in the light of recent observations in irradiated human cells deficient in the p53/14-3-3sigma pathway.Key words: PCC, embryo, oocyte, calyculin A, G2 arrest, cytokinesis.


2019 ◽  
Author(s):  
Rongqun Guo ◽  
Fangxiao Hu ◽  
Qitong Weng ◽  
Cui Lv ◽  
Hongling Wu ◽  
...  

ABSTRACTAchievement of immunocompetent and therapeutic T lymphopoiesis from pluripotent stem cells is a central aim in T cell regenerative medicine. To date, preferentially regenerating T lymphopoiesis in vivo from pluripotent stem cells (PSC) remains a practical challenge. Here we documented that synergistic and transient expression of Runx1 and Hoxa9 restricted in the time window of endothelial to hematopoietic transition and hematopoietic maturation stages induced in vitro from PSC (iR9-PSC) preferentially generated engraftable hematopoietic progenitors capable of homing to thymus and developing into mature T (iT) cells in primary and secondary immunodeficient recipients. Single-cell transcriptome and functional analyses illustrated the cellular trajectory of T lineage induction from PSC, unveiling the T-lineage specification determined at as early as hemogenic endothelial cell stage and identifying the bona fide pre-thymic progenitors. The iT cells distributed normally in central and peripheral lymphoid organs and exhibited abundant TCRαβ repertoire. The regenerative T lymphopoiesis rescued the immune-surveillance ability in immunodeficient mice. Furthermore, gene-edited iR9-PSC produced tumor-specific-T cells in vivo that effectively eradicated tumor cells. This study provides insight into universal generation of functional and therapeutic T lymphopoiesis from the unlimited and editable PSC source.


Author(s):  
Virginia Papaioannou ◽  
Randall Johnson

The ability of mammalian embryos to incorporate foreign cells and develop as chimeras has been exploited for a variety of purposes including the elucidation of cell lineages, the investigation of cell potential, the perpetuation of mutations produced in embryonic stem (ES) cells by gene targeting, and the subsequent analysis of these mutations. The extent of contribution of the foreign cells depends on their developmental synchrony with the host embryo and their mitotic and developmental potential, which may be severely restricted if the cells bear mutations. If the goal in making chimeras is the transmission of a mutation produced by gene targeting to the next generation, the mutant ES cells must have the capacity to undergo meiosis and gametogenesis. Cells from two different mammalian embryos were first combined experimentally to produce a composite animal, dubbed a chimera, nearly four decades ago. Pairs of cleaving, pre-implantation embryos were mechanically associated in vitro until they aggregated together to make single large morulae; these in turn resulted in chimeric offspring (1). Genetic markers were used to distinguish the contributions of the two embryos in these animals. Since then, various methods for making chimeras have been explored to address different types of questions (2). In 1972 it was reported that highly asynchronous embryonic cells, which had been cultured in vitro, could contribute to chimeras upon re-introduction into pre-implantation embryos (3). Not long afterward, several groups working with teratocarcinomas, tumours derived from germ cells of the gonad, discovered that stem cells from these tumours, known as embryonal carcinoma cells, could contribute to an embryo if introduced into pre-implantation stages (4-6). It appeared that the undifferentiated stem cells of the tumour had enough features in common with early embryonic cells that they could respond to the embryonic environment, differentiating in a normal manner, even after long periods in vitro. Their embryonic potential was limited, however, and many teratocarcinoma cell lines made only meagre contributions to the developing fetus or even produced tumours in chimeras (7). Either their derivation from tumours or their extended sojourn in vitro rendered these cells so dissimilar from early embryonic cells that they rarely, if ever, had full embryonic potential.


2007 ◽  
Vol 19 (1) ◽  
pp. 142
Author(s):  
K. Inoue ◽  
N. Ogonuki ◽  
H. Miki ◽  
S. Noda ◽  
S. Inoue ◽  
...  

Although cloning animals by somatic cell nuclear transfer is generally an inefficient process, use of appropriate donor cell types may improve the cloning outcome significantly. Among the donor cells tested so far, mouse embryonic stem cells have given the best efficiency in terms of the development of reconstructed embryos into offspring. In this study, we examined whether 2 in vitro-produced pluripotent stem cells—neural stem cells (NSCs) and mesenchymal stem cells (MSCs)—could be better nuclear donors than other differentiated cells. Embryos were reconstructed by transfer of nuclei from NSCs or MSCs with full potential for differentiation in vitro. Most (76%) of the 2-cell NCS embryos developed to the 4-cell stage; 43% implanted and 1.6% developed to term after transfer to pseudopregnant recipients. These rates were very similar to those of embryos cloned from fibroblast cell nuclei. Interestingly, in the patterns of zygotic gene expression, NSC embryos were more similar to in vitro-fertilized embryos than fibroblast cloned embryos. By contrast, embryos reconstructed using MSC nuclei showed lower developmental ability and no implantation was obtained after embryo transfer. Chromosomal analysis of the donor MSCs revealed very high frequencies of monosomy and trisomy, which might have caused the very poor post-implantation development of embryos following nuclear transfer. Thus, in vitro-produced pluripotent cells can serve as donors of nuclei for cloning mice, but may be prone to chromosomal aberrations leading to a high rate of cloned embryo death.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pauline Georges ◽  
Maria-Gabriela Boza-Moran ◽  
Jacqueline Gide ◽  
Georges Arielle Pêche ◽  
Benjamin Forêt ◽  
...  

Abstract Translation of pharmacological results from in vitro cell testing to clinical trials is challenging. One of the causes that may underlie these discrepant results is the lack of the phenotypic or species-specific relevance of the tested cells; today, this lack of relevance may be reduced by relying on cells differentiated from human pluripotent stem cells. To analyse the benefits provided by this approach, we chose to focus on Friedreich ataxia, a neurodegenerative condition for which the recent clinical testing of two compounds was not successful. These compounds, namely, resveratrol and nicotinamide, were selected because they had been shown to stimulate the expression of frataxin in fibroblasts and lymphoblastoid cells. Our results indicated that these compounds failed to do so in iPSC-derived neurons generated from two patients with Friedreich ataxia. By comparing the effects of both molecules on different cell types that may be considered to be non-relevant for the disease, such as fibroblasts, or more relevant to the disease, such as neurons differentiated from iPSCs, a differential response was observed; this response suggests the importance of developing more predictive in vitro systems for drug discovery. Our results demonstrate the value of utilizing human iPSCs early in drug discovery to improve translational predictability.


Reproduction ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 151-153 ◽  
Author(s):  
G. B. ANDERSON ◽  
R. H. FOOTE
Keyword(s):  

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