Project description:Human stem cell technologies including self-assembling 3D tissue models provide unprecedented access to early neurodevelopment and are enabling fundamental insights into neuropathologies. Gastruloid models have yet to be used to investigate developing neuronal systems. Here we generate elongating multi-lineage-organized (EMLO) gastruloids with trunk identity that co-develop central and peripheral nervous system (CNS, PNS) correlates. We identify neural crest cells that differentiate to form peripheral neurons integrated with an upstream spinal cord region. This follows initial EMLO polarization events and is coordinated with primitive gut tube elongation and multicellular spatial reorganization. We evaluate EMLOs over a forty-day period, applying immunofluorescence of multi-lineage and functional biomarkers, including day 16 single-cell RNA-Seq, and use them to investigate the impact of mu opioid receptor modulation on neuronal activity. This comprehensive study demonstrates the first combined human CNS-PNS model of early organogenesis in the trunk to benefit biomedical research.
Project description:Stem cell technologies including self-assembling 3D tissue models provide access to early human neurodevelopment and fundamental insights into neuropathologies. Gastruloid models have not been used to investigate co-developing central and peripheral neuronal systems with trunk mesendoderm which we achieve here in elongating multi-lineage organized (EMLO) gastruloids. We evaluate EMLOs over a forty-day period, applying immunofluorescence of multi-lineage and functional biomarkers, including day 16 single-cell RNA-Seq, and evaluation of ectodermal and non-ectodermal neural crest cells (NCCs). We identify NCCs that differentiate to form peripheral neurons integrated with an upstream spinal cord region after day 8. This follows initial EMLO polarization events that coordinate with endoderm differentiation and primitive gut tube formation during multicellular spatial reorganization. This combined human central-peripheral nervous system model of early organogenesis highlights developmental events of mesendoderm and neuromuscular trunk regions and enables systemic studies of tissue interactions and innervation of neuromuscular, enteric and cardiac relevance.
Project description:Procedure: three independent experiments were done to generate three 96-well plates of E14-Tg2A gastruloids made with either homemade or commercial N2B27. 48 gastruloids per sample were used for RNA extraction using the Qiagen RNeasy Micro Kit. Library preparation and sequencing were done by the CRG Genomics Facility (Spain). Sequencing was done in a NextSeq 2000 and generated around 30M paired-end reads per sample.
Project description:Single cell transcriptomic study (using 10x Genomics v3 kits) of gastruloids, aggregates of mESCs, at different developmental timepoints (24h, 48h and 72h post-aggregation). mESCs, corresponding to the 0h timepoint, were also sequenced. The aim of this study was to delineate the cell state transition dynamics underlying anteroposterior symmetry breaking and germ layer formation in gastruloids. Gastruloids used in this study were generated from Bra::GFP reporter mESCs (Fehling et al., 2003).
Project description:Gastruloids are three-dimensional aggregates of embryonic stem cells (ESCs) that display key features of mammalian post-implantation development, including germ layer specification and axial organization. Gastruloids have mostly been characterized with microscopy-based approaches, limiting the number of genes that can be explored. It is therefore unclear to what extent gene expression in gastruloids reflects in vivo embryonic expression. Using both single-cell RNA-seq (scRNA-seq) and spatial transcriptomics we systematically compared cell types and spatial expression patterns between mouse gastruloids and mouse embryos.
Project description:Here we show that spatially micropatterned human pluripotent stem cell (hPSC)-derived gastruloids enable in vitro modeling of the earliest developmental stages of cardiac vascularization, roughly corresponding to the first three weeks of in vivo human development (Carnegie Stages 9 and 10). Using clues from developmental biology, we identified a growth factor/small molecule cocktail, that when added to micropatterned hPSCs, generated a spatially organized, branched, and lumenized vascular network within a multi-lineage cVO comprising endocardial, myocardial, epicardial, and neuronal cell types.
Project description:Gastruloids are a powerful in vitro model of early human development. However, although elongated and composed of all three germ layers, human gastruloids do not morphologically resemble post-implantation human embryos. Here we show that an early pulse of retinoic acid (RA), together with later Matrigel, robustly induces human gastruloids with posterior embryo-like morphological structures, including a neural tube flanked by segmented somites, and diverse cell types including neural crest, neural progenitors, renal progenitors, and myocytes. Through in silico staging based on single-cell RNA-seq (scRNA-seq), we find that human RA-gastruloids progress further than other human or mouse embryo models, aligning to E9.5 mouse and CS11 cynomolgus monkey embryos. We leverage chemical and genetic perturbations of RA-gastruloids to confirm that WNT and BMP signalling regulate somite formation and neural tube length in the human context, while transcription factors TBX6 and PAX3 underpin presomitic mesoderm and neural crest, respectively. Looking forward, RA-gastruloids are a robust, scalable model for decoding early human embryogenesis.
Project description:Mammalian stem cells possess a remarkable capacity for self-organization, a property that underlies increasingly sophisticated in vitro models of early development. However, even under carefully controlled conditions, stem cell-derived models exhibit substantial “inter-individual” heterogeneity. Focusing on gastruloids, a powerful model of the early posterior embryo, we sought to investigate the origins of this heterogeneity. To this end, we developed a scalable protocol for generating gastruloids that are monoclonal, i.e. derived from a single mouse embryonic stem cell (mESC). Single cell transcriptional profiling of monoclonal gastruloids revealed extensive inter-individual heterogeneity, with some hardly progressing, others resembling conventional gastruloids but biased towards mesodermal or neural lineages, and yet others bearing cell types rare or absent from conventional polyclonal gastruloids. To investigate this further, we leveraged DNA Typewriter to record the cell lineage relationships among the mESCs from which monoclonal gastruloids originate. Early in the expansion of “founder” mESCsーi.e. prior to induction of the resulting aggregates to form gastruloidsーwe observe clear examples of fate bias or fate restriction, e.g. sister clades that exhibit markedly different cell type compositions. In a separate experiment with DNA Typewriter, we find that founder mESCs that are more closely related are more likely to give rise to monoclonal gastruloids with similar cell type compositions. Our results suggest that fluctuations in the intrinsic states of mESCs are heritable, and shape their descendants’ fates across many cell divisions. Our study also showcases how DNA Typewriter can be used to reconstruct high-resolution, monophyletic cell lineage trees in stem cell models of early development.