Modelling human pre-gastulation development by 3D culture of blastoids generated from the primed-to-naive transitioning intermediates [scRNA-seq]
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ABSTRACT: Modelling human pre-gastulation development by 3D culture of blastoids generated from the primed-to-naive transitioning intermediates [scRNA-seq]
Project description:Modelling human pre-gastulation development by 3D culture of blastoids generated from the primed-to-naive transitioning intermediates
Project description:Modelling human pre-gastulation development by 3D culture of blastoids generated from the primed-to-naive transitioning intermediates [RNA-seq]
Project description:Our study provides an alternative strategy to generate human blastoids and model early embryogenesis up to pre-gastrulation stage, facilitating the insights into human embryonic development
Project description:Our study provides an alternative strategy to generate human blastoids and model early embryogenesis up to pre-gastrulation stage, facilitating the insights into human embryonic development
Project description:Human naïve pluripotent stem cells (hnPSCs) can generate integrated models of blastocysts termed blastoids upon switch to inductive medium. However, the underlying mechanisms remain obscure. Here we report that self-renewing hnPSCs spontaneously and efficiently give rise to blastoids upon three dimensional (3D) suspension culture. The spontaneous blastoids mimic early stage human blastocysts in terms of structure, size, and transcriptome characteristics and are capable of progressing to post-implantation stages. This property is conferred by the glycogen synthase kinase-3 (GSK3) signalling inhibitor IM-12 present in 5iLAF self-renewing medium. IM-12 upregulates oxidative phosphorylation-associated genes that underly the capacity of hnPSCs to generate blastoids spontaneously. Starting from day one of self-organization, hnPSCs at the boundary of all 3D aggregates dedifferentiate into E5 embryo-like intermediates. Intermediates co-express SOX2/OCT4 and GATA6 and by day 3 specify trophoblast fate, which coincides with cavity and blastoid formation. In summary, spontaneous blastoid formation results from 3D culture triggering dedifferentiation of hnPSCs into earlier embryo-like intermediates which are then competent to segregate blastocyst fates.
Project description:A human blastoid, which is an artificial human blastocyst, and has a potential as great tool to investigate fundamentals during the development and establish in vitro models to study the pregnancy failure and birth deficiency, without the use of a human embryo. In 2021, although some methods to generate blastoids have been reported, they used human naïve pluripotent stem cells, which often show genomic instability during in vitro culture. Here, we introduce the simple, robust and scalable method to generate human blastoids from more stable human primed embryonic stem cells. By using non-cell-adhesive hydrogel, hESC aggregates received the chemophysical cellular environment, and forming the asymmetric blastoid structure with the cellular distribution like a human blastocyst. The obtained blastoids also showed the capability the implantation in vitro. This model will enable to elucidate the underlying mechanisms of human pre- and post-implantation process, leading to assisted reproductive technology.
Project description:Human blastoids provide an in vitro, embryo-free model for human implantation; however, current protocols depend on genetically unstable naïve human pluripotent stem cells (hPSCs). Here, instead of using naïve hPSCs, we report a hydrogel-based strategy that directly generates human blastoids from standard primed hPSCs. A 10% w/v poly(N-isopropyl-acrylamide)–PEG matrix mimics the zona pellucida by providing negligible adhesion and gentle confinement. Within nine days, aggregates cavitate and form epiblast, primitive endoderm, and trophectoderm—including a CCR7⁺ polar subset—attach to the extracellular matrix, secrete hCG, and initiate extravillous differentiation. Single-cell RNA-seq and RNA velocity analyses reveal early pruning of paracrine networks, preservation of an FGF2 core, and later lineage-specific reconnection. Comparative interactomics place hydrogel blastoids closest to day-5–7 embryos and show marked suppression of VEGF, PDGF, and CXCL inflammatory cues typical of naïve-cell models. This minimal, feeder-free niche enables scalable production of blastoids containing EPI, PrE, and TE-like cells from primed hPSCs.
Project description:We describe the global cell fate roadmap during primed-to-naive transition process by bulk mRNA-seq and ATAC-seq analysis among transition intermediates across different time points. We report that activation of ALPG is a landmark event for naive state establishment. Further investigation into transitioning cells with dynamic fluorescence presents intermediates branching into TE-like subpopulations with capacities of TSC derivation.