Gastruloids as in vitro models of embryonic blood development with spatial and temporal resolution

Abstract

Gastruloids are three-dimensional embryonic organoids that reproduce key features of early mammalian development in vitro with unique scalability, accessibility, and spatiotemporal similarity to real embryos. Recently, we adapted the gastruloid culture conditions to promote cardiovascular development. In this work, we extended these conditions to capture features of embryonic blood development through a combination of immunophenotyping, detailed transcriptomics analysis, and identification of blood stem/progenitor cell potency. We uncovered the emergence of blood progenitor and erythroid-like cell populations in late gastruloids and showed the multipotent clonogenic capacity of these cells, both in vitro and after transplantation into irradiated mice. We also identified the spatial localization near a vessel-like plexus in the anterior portion of gastruloids with similarities to the emergence of blood stem cells in the mouse embryo. These results highlight the potential and applicability of gastruloids to the in vitro study of complex processes in embryonic blood development with spatiotemporal fidelity.

Dissecting infant leukemia developmental origins with a hemogenic gastruloid model

“…Our hemogenic gastruloid system extends recent findings by (Rossi et al, 2022), who observed early erythro-myeloid specification in a gastruloid protocol previously developed for modelling of primordial heart development (Rossi et al, 2021). Together, our data highlight the power of gastruloid models in faithfully capturing mid-development specification of lateral mesoderm-derived programs.…”

Heart in a dish – choosing the rightin vitromodel

“…Although these organoids closely recapitulate patterns of early cardiogenesis, one major limitation of this model is the formation of mid/hindgut tissue, as identified by expression of the marker CDX2, instead of foregut endoderm as in native heart development. A follow-up study captured features of embryonic blood development in these gastruloids, increasing the complexity and value of this multi-tissue model ( Rossi et al, 2022 ). Olmsted and Paluh applied the protocol from Rossi et al (2021) to their human gastruloids, achieving a combined model for cardiogenesis, foregut development and neurogenesis ( Olmsted and Paluh, 2022 ).…”

Haematopoietic development and HSC formation in vitro: promise and limitations of gastruloid models

“…Variations of gastruloid culture conditions bias the system towards different outputs [ 75–82 ] and are discussed elsewhere in this issue. For the purpose of this review, we will consider recent reports describing the blood generation potential of gastruloids [ 76 , 77 ], summarised in Figure 2 . We will also review information on the specification of mesodermal lineages, as these are critical first events on the generation of endothelium and blood.…”

“… Black timeline represents the starting point of each protocol, up until the termination. ( A ) Protocol used by Rossi et al [ 76 ], where 300–700 cells were aggregated into 96 well-round bottom plates cultured in N2B27. A pulse of CHI99021 was added between 48 and 72 h. Post-96 h, the aggregates were transferred into 24-well plates shaking on orbital shaker (as shown in grey box) and cultured in N2B27, VEGF, bFGF and AA until 14 4h.…”