A patterned human primitive heart organoid model generated by pluripotent stem cell self-organization

Pluripotent stem cell-derived organoids can recapitulate significant features of organ development in vitro. We hypothesized that creating human heart organoids by mimicking aspects of in utero gestation (e.g., addition of metabolic and hormonal factors) would lead to higher physiological and anatomical relevance. We find that heart organoids produced using this self-organization-driven developmental induction strategy are remarkably similar transcriptionally and morphologically to age-matched human embryonic hearts. We also show that they recapitulate several aspects of cardiac development, including large atrial and ventricular chambers, proepicardial organ formation, and retinoic acid-mediated anterior-posterior patterning, mimicking the developmental processes found in the post-heart tube stage primitive heart. Moreover, we provide proof-of-concept demonstration of the value of this system for disease modeling by exploring the effects of ondansetron, a drug administered to pregnant women and associated with congenital heart defects. These findings constitute a significant technical advance for synthetic heart development and provide a powerful tool for cardiac disease modeling.

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scRNA-Sequencing data sets have been deposited in the National Center for Biotechnology Information Gene Expression Omnibus repository under accession code GSE218582.All data generated and/or analyzed in this study are provided in the published article and its supplementary information files or can be obtained from the corresponding author upon request.Source data are provided with this paper.
Power analyses of sample size were not done a priori.The rationale for pooling n=4 organoids for scRNAseq was based on a traditional and common resource efficiency approach that also yields robust averaged scRNAseq data and is common across relevant publications ((Kim et. al., 2019, PNAS, PMID: 31072937, Xiang et. al., 2017, Cell Stem Cell, PMID: 28757360).For all other experiments, n=4-14 organoids across three independent experiments were used under most circumstances (unless otherwise stated in the figure legend) where independent experiments are used in accordance with common practice in the field and relevant publications cited in this study (Lee et. al., 2020, Nature Communications, Richards et. al., 2017, Biomaterials, Andersen et. al., 2018, Nature Communications).
No data were excluded.
Replications are mentioned in both the figure legends and the Statistics and Reproducibility section of the Methods.Most experiments represent n=4-14 independent organoids per condition across three independent experiments.Technical and experimental replicates performed are noted in figure legends.
When multiple organoids were used for experiments, they were always randomly selected according to condition.
In the generation and maturation of human heart organoids, the differentiation and application of developmental strategies were performed in a non-blinded manner.Image acquisition was performed with consistent parameters, and threshold measurements were performed with consistent settings and no data was excluded to limit investigator bias.