PKD1-Dependent Renal Cystogenesis in Human Induced Pluripotent Stem Cell-Derived Ureteric Bud/Collecting Duct Organoids

Significance Statement Models of autosomal dominant polycystic kidney disease (ADPKD) are possible in nephron progenitor–derived human kidney organoids that form from induced pluripotent stem cells (iPSCs) that have had PKD genes deleted, enabling cyst formation. However, this has not been achieved in the ureteric bud/collecting duct lineage, despite the prevalence of collecting duct cysts in patients. Cysts formed in ureteric bud organoids derived from iPSCs with homozygous deleted PKD1 , as well as in ureteric bud organoids generated from heterozygous mutant iPSCs and from a patient with ADPKD who had a heterozygous missense mutation, all upon cAMP stimulation. These PKD1 mutant organoids can model human ADPKD in the collecting duct lineage, complementing existing cell and animal models. Background Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease leading to renal failure, wherein multiple cysts form in renal tubules and collecting ducts derived from distinct precursors: the nephron progenitor and ureteric bud (UB), respectively. Recent progress in induced pluripotent stem cell (iPSC) biology has enabled cyst formation in nephron progenitor–derived human kidney organoids in which PKD1 or PKD2 , the major causative genes for ADPKD, are deleted. However, cysts have not been generated in UB organoids, despite the prevalence of collecting duct cysts in patients with ADPKD. Methods CRISPR-Cas9 technology deleted PKD1 in human iPSCs and the cells induced to differentiate along pathways leading to formation of either nephron progenitor or UB organoids. Cyst formation was investigated in both types of kidney organoid derived from PKD1 -deleted iPSCs and in UB organoids generated from iPSCs from a patient with ADPKD who had a missense mutation. Results Cysts formed in UB organoids with homozygous PKD1 mutations upon cAMP stimulation and, to a lesser extent, in heterozygous mutant organoids. Furthermore, UB organoids generated from iPSCs from a patient with ADPKD who had a heterozygous missense mutation developed cysts upon cAMP stimulation. Conclusions Cysts form in PKD1 mutant UB organoids as well as in iPSCs derived from a patient with ADPKD. The organoids provide a robust model of the genesis of ADPKD.