Gentamicin impairs nephron development in iPSC-derived kidney organoids and disrupts proximal tubular lysosomal function

Gentamicin is an aminoglycoside antibiotic used to treat Gram-negative bacterial infections. However, its clinical use is limited by nephrotoxicity, affecting approximately 10 - 20% of treated patients. Nevertheless, gentamicin remains widely used due to its high potency, low cost, and low incidence of bacterial resistance and hypersensitivity. Importantly, gentamicin crosses the placental barrier and is administered to neonates, including preterm infants in whom nephrogenesis is still ongoing, raising concerns about its effects on kidney development. Current knowledge of this risk relies largely on rodent studies, which fail to fully recapitulate human kidney physiology. Here, we developed human-relevant in vitro models to investigate the impact of gentamicin on kidney development and to unravel the dynamic cellular responses underlying gentamicin-induced impairment. Kidney organoids differentiated from induced pluripotent stem cells (iPSC) and magnetically sorted proximal tubule cells were used to model immature kidney and immature proximal cells, respectively. Organoids were continuously exposed to gentamicin (0.25 - 1.5 mM) throughout development (d7+18), while megalin-expressing proximal tubule cells were exposed for 24 hours to explore the cellular mechanisms underlying gentamicin toxicity. Intracellular concentrations of the gentamicin congeners C1, C1a, and C2/C2a/C2b were quantified by LC-MS/MS. Gentamicin exposure impaired organoid growth, and nephron formation and maturation. Additionally, gentamicin induced lipid accumulation and reduced lysosomal area in proximal tubule cells, indicating disrupted cellular metabolism and homeostasis. In conclusion, iPSC-derived kidney organoids provide a suitable platform to further investigate gentamicins impact on kidney development and studying co-treatments to mitigate its adverse effects.