scholarly journals Early neurulation recapitulated in assemblies of embryonic and extraembryonic cells

Author(s):  
Noémie M. L. P. Bérenger-Currias ◽  
Maria Mircea ◽  
Esmée Adegeest ◽  
Patrick R. van den Berg ◽  
Marleen Feliksik ◽  
...  

Recapitulating mammalian embryonic development in vitro is a major challenge in biology. It has been shown that gastruloids1–5 and ETX embryos6 can display hallmarks of gastrulation in vitro. However, these models fail to progress beyond spatially segregated, yet amorphous cellular assemblies. Systems such as organoids7 do show tissue stratification and organogenesis, but require adult stem cells or exogeneous induction of specific cell fates, and hence do not reflect the emergent organization of embryonic development. Notably, gastruloids are derived exclusively from embryonic stem cells (ESCs), whereas, in vivo, crucial patterning cues are provided by extraembryonic cells8. Here, we show that assemblies of mouse ESCs (mESCs) and extraembryonic endoderm (XEN) cells can develop beyond gastrulation and produce a central hallmark of organogenesis: stratified neural epithelia resembling a neural tube, which can be further differentiated to cerebral cortex-like tissue. By single-cell RNA-seq, we show that our model has a larger cell type diversity than existing models, and that mESCs and XEN cells impact each other’s differentiation. XEN cells promote neural tube formation through local inhibition of primitive streak formation. In turn, the presence of mESCs drives XEN cells to resemble visceral endoderm, which envelops the embryo in vivo. This study provides a model system to investigate neurulation and extraembryonic endoderm development, and may serve as a starting point to generate embryo models that advance further toward the formation of the vasculature, nervous system, and digestive tube.

2017 ◽  
Author(s):  
Luca Tosti ◽  
James Ashmore ◽  
Boon Siang Nicholas Tan ◽  
Benedetta Carbone ◽  
Tapan K Mistri ◽  
...  

AbstractThe identification of transcription factor (TF) binding sites in the genome is critical to understanding gene regulatory networks (GRNs). While ChIP-seq is commonly used to identify TF targets, it requires specific ChIP-grade antibodies and high cell numbers, often limiting its applicability. DNA adenine methyltransferase identification (DamID), developed and widely used in Drosophila, is a distinct technology to investigate protein-DNA interactions. Unlike ChIP-seq, it does not require antibodies, precipitation steps or chemical protein-DNA crosslinking, but to date it has been seldom used in mammalian cells due to technical impediments. Here we describe an optimised DamID method coupled with next generation sequencing (DamID-seq) in mouse cells, and demonstrate the identification of the binding sites of two TFs, OCT4 and SOX2, in as few as 1,000 embryonic stem cells (ESCs) and neural stem cells (NSCs), respectively. Furthermore, we have applied this technique in vivo for the first time in mammals. Oct4 DamID-seq in the gastrulating mouse embryo at 7.5 days post coitum (dpc) successfully identified multiple Oct4 binding sites proximal to genes involved in embryo development, neural tube formation, mesoderm-cardiac tissue development, consistent with the pivotal role of this TF in post-implantation embryo. This technology paves the way to unprecedented investigations of TF-DNA interactions and GRNs in specific cell types with limited availability in mammals including in vivo samples.


2011 ◽  
Vol 17 (4) ◽  
pp. 520-527 ◽  
Author(s):  
A. Henry Sathananthan

AbstractThe process of neurogenesis and formation of neural stem cells is reported in human neurospheres (NS) and embryoid bodies (EB) derived from human embryonic stem cells, in vitro, and compared with neural tissue formed in human ectopic embryos in week 4 (stage 9), developed in vivo. This morphological study was done using digital imaging by light microscopy and routine transmission electron microscopy. Both NS and EB form neural rosettes from the surface epithelium much like the process of neural tube formation from ectoderm in the embryo. The rosette is the developmental signature of neuroprogenitors in cultures of differentiating embryonic stem cells and is a radial arrangement of columnar cells that express many of the proteins expressed in neuroepithelial cells in the neural tube. The NS produce all of the major classes of progeny of the neural tube, some of which have been documented here. Specific neural markers expressed in the NS and the clinical implications of this study in cell therapy are also discussed.


Author(s):  
Jesse V Veenvliet ◽  
Adriano Bolondi ◽  
Helene Kretzmer ◽  
Leah Haut ◽  
Manuela Scholze-Wittler ◽  
...  

AbstractPost-implantation embryogenesis is a highly dynamic process comprising multiple lineage decisions and morphogenetic changes inaccessible to deep analysis in vivo. Mouse embryonic stem cells (mESCs) can form aggregates reflecting the post-occipital embryo (gastruloids), but lacking proper morphogenesis. Here we show that embedding of aggregates derived from mESCs in an extracellular matrix compound results in Trunk-Like-Structures (TLS) with a high level of organization comprising a neural tube and somites. Comparative single-cell RNA-seq analysis demonstrates that TLS execute gene-regulatory programs in an embryo-like order, and generate primordial germ cell like cells (PGCLCs). TLS lacking Tbx6 form ectopic neural tubes, mirroring the embryonic mutant phenotype. ESC-derived trunk-like structures thus constitute a novel powerful in vitro platform for investigating lineage decisions and morphogenetic processes shaping the post-implantation embryo.One sentence summaryA platform for generating trunk-like-structures with precursors of spinal cord, bone and muscle from stem cells in a dish


2021 ◽  
Author(s):  
Daniel Medina-Cano ◽  
Emily K. Corrigan ◽  
Rachel A. Glenn ◽  
Mohammed Tarek Islam ◽  
Yuan Lin ◽  
...  

Directed differentiation of pluripotent stem cells (PSCs) is a powerful model system for deconstructing embryonic development. Although mice are the most advanced mammalian model system for genetic studies of embryonic development, state-of-the-art protocols for directed differentiation of mouse PSCs into defined lineages tend to be slower and generate target cell types with lower purity than analogous protocols for human PSCs, limiting their application as models for mechanistic studies of development. Here, we examine the potential of mouse epiblast stem cells (EpiSCs) cultured in media containing Wnt pathway inhibitors (primed ground state conditions) as a starting point for directed differentiation. As a proof-of-concept, we focused our efforts on two specific cell/tissue types that have proven difficult to generate efficiently and reproducibly from mouse embryonic stem cells: definitive endoderm and neural organoids. First, we developed a new protocol that can rapidly generate nearly pure definitive endoderm from EpiSCs. Second, we developed a protocol for generating forebrain organoids that model the development of prethalamic and hippocampal neurons. These significantly improved differentiation models present new possibilities for combining mouse genetic tools and resources with in vitro differentiation to characterize the molecular and cellular mechanisms of embryonic development.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Mohsin Khan ◽  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin Vaughan ◽  
Srikanth Garikipati ◽  
...  

Rationale: Embryonic stem cells (ESCs) hold great promise for cardiac regeneration but are susceptible to ethical concerns, lack of autologous donors and teratoma formation. Recently, it has been observed that beneficial effects of stem cells are mediated by exosomes secreted out under various physiological conditions. ESCs have the ability to produce exosomes however their effect in the context of the heart is unknown. Objective: Determine the effect of ESC derived exosomes for cardiac repair and modulation of CPCs functions in the heart following myocardial infarction. Methods and Results: Exosomes were isolated from murine ESCs (mES Ex) or embryonic fibroblasts (MEFs) by ultracentrifugation and verified by Flotillin-1 immunoblot analysis. Induction of pluripotent markers, survival and in vitro tube formation was enhanced in target cells receiving ESC exosomes indicating therapeutic potential of mES Ex. mES Ex administration resulted in enhanced neovascularization, cardiomyocyte survival and reduced fibrosis post infarction consistent with resurgence of cardiac proliferative response. Importantly, mES Ex mediated considerable enhancement of cardiac progenitor cell (CPC) survival, proliferation and cardiac commitment concurrent with increased c-kit+ CPCs in vivo 4 weeks after mES Ex transfer. miRNA Array analysis of ESC and MEF exosomes revealed significantly high expression of miR290-295 cluster in the ESC exosomes compared to MEF exosomes. The underlying beneficial effect of mES Ex was tied to delivery of ESC miR-294 to the heart and in particular CPCs thereby promoting CPC survival and proliferation as analyzed by FACS based cell death analysis and CyQuant assay respectively. Interestingly, enhanced G1/S transition was observed in CPCs treated with miR-294 in conjunction with significant reduction of G1 phase. Conclusion: In conclusion, mES Ex provide a novel cell free system for cardiac regeneration with the ability to modulate both cardiomyocyte and CPC based repair programs in the heart thereby avoiding the risk of teratoma formation associated with ESCs.


2020 ◽  
Author(s):  
Nathalia Azevedo ◽  
Elisa Bertesago ◽  
Ismail Ismailoglu ◽  
Michael Kyba ◽  
Michihiro Kobayashi ◽  
...  

AbstractThe in vitro generation from pluripotent stem cells (PSCs) of different blood cell types, in particular those that are not replenished by hematopoietic stem cells (HSCs) like fetal-derived tissue-resident macrophages and innate-like lymphocytes, is of a particular interest. In order to succeed in this endeavor, a thorough understanding of the pathway interplay promoting lineage specification for the different blood cell types is needed. Notch signaling is essential for the HSC generation and their derivatives, but its requirement for tissue-resident immune cells is unknown. Using mouse embryonic stem cells (mESCs) to recapitulate murine embryonic development, we have studied the requirement for Notch signaling during the earliest B-lymphopoiesis and found that Rbpj-deficient mESCs are able to generate B-1 cells. Their Notch-independence was confirmed in ex vivo experiments using Rbpj-deficient embryos. In addition, we found that upregulation of Notch signaling was needed for the emergence of B-2 lymphoid cells. Taken together, these findings indicate that control of Notch signaling dosage is critical for the different B-cell lineage specification and provides pivotal information for their in vitro generation from PSCs for therapeutic applications.


2015 ◽  
Vol 13 (1) ◽  
pp. 720-730 ◽  
Author(s):  
LIPING OU ◽  
LIAOQIONG FANG ◽  
HEJING TANG ◽  
HAI QIAO ◽  
XIAOMEI ZHANG ◽  
...  

Author(s):  
Hao Xu ◽  
Liying Wu ◽  
Guojia Yuan ◽  
Xiaolu Liang ◽  
Xiaoguang Liu ◽  
...  

: Hepatic disease negatively impacts liver function and metabolism. Primary human hepatocytes are the gold standard for the prediction and successful treatment of liver disease. However, the sources of hepatocytes for drug toxicity testing and disease modeling are limited. To overcome this issue, pluripotent stem cells (PSCs) have emerged as an alternative strategy for liver disease therapy. Human PSCs, including embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) can self-renew and give rise to all cells of the body. Human PSCs are attractive cell sources for regenerative medicine, tissue engineering, drug discovery, and developmental studies. Several recent studies have shown that mesenchymal stem cells (MSCs) can also differentiate (or trans-differentiate) into hepatocytes. Differentiation of human PSCs and MSCs into functional hepatocyte-like cells (HLCs) opens new strategies to study genetic diseases, hepatotoxicity, infection of hepatotropic viruses, and analyze hepatic biology. Numerous in vitro and in vivo differentiation protocols have been established to obtain human PSCs/MSCs-derived HLCs and mimic their characteristics. It was recently discovered that microRNAs (miRNAs) play a critical role in controlling the ectopic expression of transcription factors and governing the hepatocyte differentiation of human PSCs and MSCs. In this review, we focused on the role of miRNAs in the differentiation of human PSCs and MSCs into hepatocytes.


2020 ◽  
pp. 019262332091824
Author(s):  
Richard Haworth ◽  
Michaela Sharpe

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.


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