HUMAN FETAL KIDNEY ORGANOIDS MODEL EARLY NEPHROGENESIS AND NOTCH-DRIVEN CELL FATE [scRNA-seq]

Pluripotent stem cell–derived kidney organoids (PSC-KOs) are widely used to model human kidney development and disease. However, organoids from human fetal kidney tissue (hFKOs), which could benchmark PSC-KOs, remain underdeveloped. Here, using a chemically defined serum-free medium, we established a prolonged culture protocol for hFKOs that self-organize into polarized renal epithelium, reinitiate from NCAM1+ progenitors, and recapitulate nephrogenic and ureteric bud lineages. Bulk transcriptomics, single-cell RNA sequencing, pseudotime analysis, and immunostaining revealed diverse cell populations, with a preserved epithelial progenitor pool and tubular differentiation axis—both more robust than in PSC-KOs. hFKOs were enriched for NOTCH signaling genes, enabling single-cell analysis of pharmacological NOTCH inhibition. This revealed a maturation block with increased nephron progenitors and a bias toward distal over early proximal tubule fates. We also identified a novel prominin-1–expressing cell state that evades NOTCH inhibition to generate both proximal and distal tubules. Overall, hFKOs provide a developmentally faithful model and offer critical insights into kidney morphogenesis, advancing the fields of stem cell biology and regenerative medicine. Overall design: Two samples of human fetal kidney organoids (hFKOs) at P0 after 2-3 weeks of culture, one hFKO sample derived from week 20 thawed human fetal kidney cells (hFK18) the other hFKOs sample derived from freshly dissociated week 15 of gestation human fetal kidney (hFK26).