Modeling Development and Disease from Human Pluripotent Stem Cell-Derived Mature and Functional Cortical Collecting Duct Organoid

Background: Directed differentiation of kidney cell types from human pluripotent stem cells (hPSCs) empowers the study of kidney development and diseases and is essential for kidney regenerative medicine. During embryogenesis, Wnt11+ ureteric progenitor cells (UPCs) self-renew and differentiate to form a tree-like collecting duct (CD) system that refines and drains the urine. Previously, we have established long-term culture platforms to expand primary mouse and human UPCs, and UPCs induced from hPSCs, in the format of 3D expandable ureteric bud (UB) organoids. Starting from expandable mouse UPCs, we generated spatially organized CD organoid consisting of principal cells (PCs) and intercalated cells (ICs). However, robust human CD organoid models with the presence of both PCs and ICs are still lacking. Methods: Starting from expandable hPSC-derived UPCs, we developed a stepwise chemically defined culture system to generate elongated cortical human CD organoids with spatially organized PCs and ICs. Electrophysiological analysis of these generated CD organoids was demonstrated through patch clamp and ussing chamber to measure ion channel activities. CRISPR/Cas9 genome editing was used to generate an efficient and scalable organoid model for polycystic kidney disease (PKD). Results: The elongated human CD organoids well recapitulate both maturity and functionality of human cortical CD. Differentiation from UPCs to CD recapitulates normal human CD development, with the transcriptome transitioning sequentially from UB tip, UB trunk, to the mature CD profiles. Importantly, these cortical CD organoids demonstrate electrophysiologic functions, such as active sodium, potassium, and chloride ion channel activities as recorded by patch clamp. Moreover, a robust CD organoid model of PKD was developed upon PKD2 gene knockout, reflecting cystic phenotypes and a variety of pathogenic features of the disease. Transcriptome analyses further identified molecular features unique to cystogenesis in the kidney’s CD. A scalable PKD organoid model was developed, enabling high-throughput drug screening. Conclusion: Taken together, this mature and functional human cortical CD organoid platform opens new avenues for studying human CD development and modeling kidney diseases of the ureteric lineage. Funding: NIDDK Support - NIDDK Support, NIDDK Support, Private Foundation Support