O-045 Synthetic human embryo-like structures: a new paradigm for human embryology

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
J Fu
Keyword(s):  
Stem Cell ◽  
Human Development ◽  
Cell Biology ◽  
Primordial Germ Cell ◽  
Primitive Streak ◽  
Culture Conditions ◽  
Experimental Models ◽  
New Paradigm ◽  
Amniotic Cavity ◽  
Germ Cell Specification

Abstract text Early human development remains mysterious and very difficult to study. Recent advances in mammalian embryology, stem cell biology, organoid technology, and bioengineering have contributed to a significant interest in bottom-up, synthetic stem cell-derived models of human development (or embryoids). The controllability and reproducibility of human embryoids coupled with the ease of genetically modifying stem cell lines, the ability to manipulate culture conditions and the simplicity of live imaging make them robust and attractive systems to disentangle cellular behaviors and signaling interactions that drive human embryogenesis. In this talk, I will describe our effort in using human pluripotent stem cells (hPSCs) to develop tractable experimental models of the peri-implantation embryonic development and neurulation. The peri-implantation human embryoids developed by us recapitulate key early post-implantation developmental landmarks successively, including pro-amniotic cavity formation, amniotic ectoderm-epiblast patterning, primordial germ cell specification, and development of the primitive streak with controlled anteroposterior polarity. I will further discuss an hPSC-based neuroectoderm patterning model to recapitulate the formation of the neural plate and another patterned neural tube model with fully defined anterior-posterior and dorsal-ventral axes.

scholarly journals Opening the black box: Stem cell–based modeling of human post-implantation development

2018 ◽  
Vol 218 (2) ◽  
pp. 410-421 ◽  
Author(s):  
Kenichiro Taniguchi ◽  
Idse Heemskerk ◽  
Deborah L. Gumucio
Keyword(s):  
Stem Cell ◽  
Human Development ◽  
Experimental Models ◽  
Uterine Wall ◽  
Black Box ◽  
Cellular Mechanisms ◽  
Early Human Development ◽  
Post Implantation ◽  
Early Human

Proper development of the human embryo following its implantation into the uterine wall is critical for the successful continuation of pregnancy. However, the complex cellular and molecular changes that occur during this post-implantation period of human development are not amenable to study in vivo. Recently, several new embryo-like human pluripotent stem cell (hPSC)–based platforms have emerged, which are beginning to illuminate the current black box state of early human post-implantation biology. In this review, we will discuss how these experimental models are carving a way for understanding novel molecular and cellular mechanisms during early human development.

scholarly journals Reconstructing human early embryogenesis in vitro with pluripotent stem cells

2021 ◽  
Author(s):  
Berna Sozen ◽  
Victoria Jorgensen ◽  
Meng Zhu ◽  
Tongtong Cui ◽  
Magdalena Zernicka-Goetz
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Human Development ◽  
Pluripotent Stem Cells ◽  
Molecular Mechanisms ◽  
Early Embryo ◽  
Human Stem Cells ◽  
Amniotic Cavity ◽  
Early Human

ABSTRACTUnderstanding human development is of fundamental biological and clinical importance. Yet despite its significance, insights into early developmental events in humans still remain largely unknown. While recent advances show that stem cells can mimic embryogenesis1–9 to unravel hidden developmental mechanisms, a stem cell-based model of early human embryogenesis is lacking. Here, we use human extended pluripotent stem cells10to reconstitute early human development in 3-dimensions and recapitulate early embryo-like events. We first perform a systematic characterisation to reveal unique signalling requirements for building the human pre-implantation blastocyst. Further, we show that these in vitro stem cell-derived blastocyst-like structures are able to undertake spatiotemporal self-organisation to mimic peri-implantation remodelling in which a polarised rosette opens up the amniotic cavity within a developing disc. The hallmarks of human early development displayed by this stem cell-based in vitro model mimics features of embryonic day 3 to day 9/10 of natural development. Thus, this platform represents a tractable model system to contribute to the basic understanding of cellular and molecular mechanisms governing early embryonic events in humans and to provide valuable insights into the design of differentiation protocols for human stem cells in clinical applications.

scholarly journals Defining the transcriptional signature of esophageal-to-skin lineage conversion

2021 ◽  
Author(s):  
Maria T. Bejar ◽  
Paula Jimenez-Gomez ◽  
Ilias Moutsopoulos ◽  
Bartomeu Colom ◽  
Seungmin Han ◽  
...  
Keyword(s):  
Stem Cell ◽  
Epithelial Cells ◽  
Cell Fate ◽  
Cell Biology ◽  
3D Culture ◽  
New Paradigm ◽  
Transcriptional Signature ◽  
3D Culture System ◽  
Cell Fate Conversion

AbstractThe ability of epithelial cells to rewire their cell fate program beyond their physiological repertoire has become a new paradigm in stem cell biology. This plasticity leaves behind the concept of strict stem cell hierarchies, opening up new exciting questions about its limits and underlying regulation. Here we developed a heterotypic 3D culture system to study the mechanisms modulating changes in the identity of adult esophageal epithelial cells. We demonstrate that, when exposed to the foreign stroma of adult skin, esophageal cells transition towards hair follicle identity and architecture. Heterotypic transplantation experiments recapitulated this cell fate conversion processin vivo. Single-cell RNA sequencing and histological analysis, capturing the temporality of this process, reveal that most esophageal cells switching towards skin identity remain in an intermediate state marked by a transient regenerative profile and a particularly strong hypoxic signature. Inhibition of HIF1a establishes the central role of this pathway in regulating epithelial cell plasticity, driving cells away from their transition state in favor of cell fate conversion.

scholarly journals Modeling human trophoblast, the placental epithelium at the maternal fetal interface

Reproduction ◽  
2020 ◽  
Vol 160 (1) ◽  
pp. R1-R11 ◽  
Author(s):  
Mariko Horii ◽  
Ojeni Touma ◽  
Tony Bui ◽  
Mana M Parast
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Culture Conditions ◽  
Model Systems ◽  
Placental Development ◽  
Human Organ ◽  
Human Trophoblast

Appropriate human trophoblast lineage specification and differentiation is crucial for the establishment of normal placentation and maintenance of pregnancy. However, due to the lack of proper modeling systems, the molecular mechanisms of these processes are still largely unknown. Much of the early studies in this area have been based on animal models and tumor-derived trophoblast cell lines, both of which are suboptimal for modeling this unique human organ. Recent advances in regenerative and stem cell biology methods have led to development of novel in vitro model systems for studying human trophoblast. These include derivation of human embryonic and induced pluripotent stem cells and establishment of methods for the differentiation of these cells into trophoblast, as well as the more recent derivation of human trophoblast stem cells. In addition, advances in culture conditions, from traditional two-dimensional monolayer culture to 3D culturing systems, have led to development of trophoblast organoid and placenta-on-a-chip model, enabling us to study human trophoblast function in context of more physiologically accurate environment. In this review, we will discuss these various model systems, with a focus on human trophoblast, and their ability to help elucidate the key mechanisms underlying placental development and function. This review focuses on model systems of human trophoblast differentiation, including advantages and limitations of stem cell-based culture, trophoblast organoid, and organ-on-a-chip methods and their applications in understanding placental development and disease.

Modeling and Studying Human Embryonic Stem Cell Culture Conditions in Pulsed Flow Micro-Reactors

2008 ◽  
Author(s):  
Natanel Korin ◽  
Avishay Bransky ◽  
Uri Dinnar ◽  
Shulamit Levenberg
Keyword(s):  
Tissue Engineering ◽  
Stem Cell ◽  
Mass Transport ◽  
Embryonic Stem Cell ◽  
Cell Biology ◽  
Embryonic Stem ◽  
Culture Conditions ◽  
Perfusion System ◽  
Long Term Culture

Embryonic stem (ES) cells research is a promising field for tissue engineering due to their proliferative capacity and differentiation abilities. The culture of Human Embryonic Stem Cells (hESC) in microchannel bioreactors can be valuable for hESC cell biology studies and hESC tissue engineering applications. We have previously demonstrated the long-term culture of mammalian (HFF-Human Foreskin Fibroblasts) cells in a microchannel (130μm) bioreactor under constant perfusion in a simple approach. However, hESC were found to be highly sensitive to flow and did not grow under flow rates which were proper for HFF long-term culture. Here, we propose the use of a novel automated periodic perfusion system to co-culture hESC with HFF in a microchannel bioreactor. The method is based on short temporal pulsed flows of medium renewal followed by long static incubation periods. The short pulsed exposure to shear enables shear sensitive cells (e.g., hESC) to withstand the medium flow. The present work studies experimentally and via numerical simulations the conditions required for hESC culture in a microchannel bioreactor using the periodic perfusion method. Conventional soft-lithography techniques were used to fabricate PDMS microchannels (100 μm) sealed reversibly with glass cover slides. HESC were seeded in the microchannel with HFF, incubated for several hours and then connected to a perfusion system which contained: a syringe pump, a permeable tube oxygenator, and waste container. The ability of the periodic perfusion protocols to prevent hESC de-attachment and maintain their culture was examined. Mass transport and fluid mechanics models were used to evaluate the culture conditions within the micro-bioreactor (shear stress, oxygen level, nutritious etc.). 3D finite element mass transport analysis (Comsol 3.3) was preformed to examine the oxygen levels in the microchannel as a function of time and design parameters. Altogether, the experimental results and the theoretical model indicate that the use of a periodic perfusion bioreactor is a suitable and promising method to culture hESC in a microreactor. Culturing undifferentiated human ES cell colonies in a micro-bioreactor is an initial step toward utilizing microfluidic techniques to investigate embryonic stem cell biology.

scholarly journals Transcriptomic, epigenetic and metabolic characterization of the pluripotency continuum in rabbit preimplantation embryos

2021 ◽  
Author(s):  
Wilhelm Bouchereau ◽  
Luc Jouneau ◽  
Catherine Archilla ◽  
Irene Aksoy ◽  
Anais Moulin ◽  
...  
Keyword(s):  
Stem Cell ◽  
Single Cell ◽  
Cell Biology ◽  
Molecular Level ◽  
Rabbit Model ◽  
Primitive Streak ◽  
Preimplantation Embryos ◽  
Morula Stage ◽  
Stem Cell Lines

Despite the growing interest in the rabbit model for developmental and stem cell biology, the characterization of embryos at the molecular level is still poorly documented. We conducted a transcriptome analysis of rabbit pre-implantation embryos from E2.7 (morula stage) to E6.6 (early primitive streak stage) using bulk and single-cell RNA-sequencing, and single-cell Biomark qPCR. In parallel, we studied oxidative phosphorylation and glycolysis and analyzed active and repressive epigenetic modifications during blastocyst formation and expansion. We generated a transcriptomic, epigenetic, and metabolic map of the pluripotency continuum in rabbit preimplantation embryos and identified novel markers of naive pluripotency that might be instrumental for deriving naive pluripotent stem cell lines. Although the rabbit is evolutionarily closer to mice than to primates, we found that the transcriptome of rabbit epiblast cells shares common features with that of humans and non-human primates.

scholarly journals Mesenchymal stem cells from biology to therapy

2021 ◽  
Author(s):  
David Kuntin ◽  
Paul Genever
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Culture Conditions ◽  
Pure Cell ◽  
Cell Sources ◽  
Scientific Challenge ◽  
Unique Markers ◽  
Regenerate Tissue

Mesenchymal stem cells are as fascinating as they are enigmatic. They appear capable of performing a wide array of functions that cross skeletal biology, immunology and haematology. As therapeutics, mesenchymal stem cells or even just their secreted products may be used to regenerate tissue lost through injury or disease and suppress damaging immune reactions. However, these cells lack unique markers and are hard to identify and isolate as pure cell populations. They are often grown in laboratories using basic and undefined culture conditions. We cannot even agree on their name. While mesenchymal stem cells may lack the developmental understanding and defined differentiation hierarchies of their more illustrious stem cell cousins, they offer a compelling scientific challenge. In depth understanding of mesenchymal stem cell biology will enable us to exploit fully one of the most clinically valuable cell sources.

scholarly journals Primordial Germ Cells: Current Knowledge and Perspectives

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Aleksandar Nikolic ◽  
Vladislav Volarevic ◽  
Lyle Armstrong ◽  
Majlinda Lako ◽  
Miodrag Stojkovic
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Cell Biology ◽  
Current Knowledge ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Medical Application ◽  
Therapeutic Possibility

Infertility is a condition that occurs very frequently and understanding what defines normal fertility is crucial to helping patients. Causes of infertility are numerous and the treatment often does not lead to desired pregnancy especially when there is a lack of functional gametes. In humans, the primordial germ cell (PGC) is the primary undifferentiated stem cell type that will differentiate towards gametes: spermatozoa or oocytes. With the development of stem cell biology and differentiation protocols, PGC can be obtained from pluripotent stem cells providing a new therapeutic possibility to treat infertile couples. Recent studies demonstrated that viable mouse pups could be obtained fromin vitrodifferentiated stem cells suggesting that translation of these results to human is closer. Therefore, the aim of this review is to summarize current knowledge about PGC indicating the perspective of their use in both research and medical application for the treatment of infertility.

scholarly journals Three-dimensional model of glioblastoma by co-culturing tumor stem cells with human brain organoids

Biology Open ◽  
2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Roberta Azzarelli ◽  
Michela Ori ◽  
Anna Philpott ◽  
Benjamin D. Simons
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Biology ◽  
Three Dimensional ◽  
3D Culture ◽  
Significant Degree ◽  
Culture Conditions ◽  
Three Dimensional Model ◽  
The Impact

ABSTRACT Emerging three-dimensional (3D) cultures of glioblastoma are becoming powerful models to study glioblastoma stem cell behavior and the impact of cell–cell and cell–microenvironment interactions on tumor growth and invasion. Here we describe a method for culturing human glioblastoma stem cells (GSCs) in 3D by co-culturing them with pluripotent stem cell-derived brain organoids. This requires multiple coordinated steps, including the generation of cerebral organoids, and the growth and fluorescence tagging of GSCs. We highlight how to recognize optimal organoid generation and how to efficiently mark GSCs, before describing optimized co-culture conditions. We show that GSCs can efficiently integrate into brain organoids and maintain a significant degree of cell fate heterogeneity, paving the way for the analysis of GSC fate behavior and lineage progression. These results establish the 3D culture system as a viable and versatile GBM model for investigating tumor cell biology and GSC heterogeneity. This article has an associated First Person interview with the first author of the paper.

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