Human iPSC-derived nephron progenitor cells treat AKI and CKD in mouse models

The number of patients requiring dialysis therapy continues to increase worldwide due to the lack of effective treatments for chronic kidney disease (CKD). Furthermore, no curative treatments for acute kidney injury (AKI) have been established. The therapeutic effects of human induced pluripotent stem cell-derived nephron progenitor cells (hiPSC-NPCs) on AKI have been reported in mice but not clinically confirmed. There are also no reports examining the therapeutic potential of hiPSC-NPCs on CKD. Although large numbers of uniform hiPSC-NPCs are required for cell therapies for AKI and CKD, effective expansion cultures remain to be developed. Here, we established a CFY (CHIR99021, FGF9, Y-27632) medium for cell culture that enables more than 100-fold proliferation of hiPSC-NPCs from multiple hiPSC lines in two passages. We demonstrated that hiPSC-NPCs expanded by CFY or their conditioned medium alone attenuate kidney injury and improve survival in cisplatin-induced AKI mice. We also observed that hiPSC-NPCs prevented kidney functional decline, interstitial fibrosis, and senescence in aristolochic acid-induced CKD mice. In addition, we discovered c-MET as a specific cell surface marker for hiPSC-NPCs and confirmed that purified c-MET+ hiPSC-NPCs have therapeutic effects on AKI and CKD. Furthermore, we found that hiPSC-NPCs exerted their therapeutic effects in AKI and CKD mice by secreting vascular endothelial growth factor A (VEGF-A). Together, expanded hiPSC-NPCs are useful cell therapies for AKI and CKD, and may open new avenues for treating kidney diseases.