Nephrotoxicity assessment of Esculentoside A using human-induced pluripotent stem cell-derived organoids

Drug-induced nephrotoxicity is a leading cause of acute kidney injury (AKI). A major obstacle in predicting AKI is the lack of a comprehensive experimental model that mimics stable and physiologically relevant kidney functions and accurately reflects the changes a drug induces. Organoids derived from human-induced pluripotent stem cells (iPSCs) are promising models because of their reproducibility and similarity to the in vivo conditions. In this study, Esculentoside A, the triterpene saponin with the highest concentration isolated from the root of Phytolacca acinose Roxb., was used to induce kidney injury models in vivo and kidney organoids. Esculentoside A induced AKI in mice, together with pathological changes and enhanced apoptosis. Moreover, Esculentoside A damaged podocytes and proximal tubular endothelial cells in kidney organoids in a similar way as in vivo. We also found that treatment with 60 μM Esculentoside A induced the known biomarkers of kidney damage and inflammatory cytokines (such as kidney injury molecule (KIM-1), β2-microglobulin (β2-M), and cystatin C (CysC)) in the organoids, in which activation of Cleaved Caspase-3 was involved, possibly due to lowered mitochondrial membrane potential. In summary, this study strongly suggests using kidney organoids as a reliable platform to assess Chinese medicine-induced nephrotoxicity.