# Impact of nephrotoxins and oxidants on survival and transport function of hiPSC-derived renal proximal tubular cells

## TL;DR

This study shows that developing kidney cells are highly sensitive to toxins and oxidants, which may hinder kidney regeneration.

## Contribution

The study reveals that differentiation stages of kidney cells are uniquely vulnerable to nephrotoxins and oxidants.

## Key findings

- Differentiating cells are most sensitive to oxidants and cisplatin.
- Cisplatin and cyclosporin A impair albumin uptake in differentiated cells.
- Toxins during differentiation cause long-term gene expression changes.

## Abstract

Due to their role in excretion, renal proximal tubular cells are susceptible to damage by toxic metabolites and xenobiotics. The regenerative capacity of the kidney allows for the replacement of damaged cells, a process involving differentiation programs. However, kidney function tends to decline, suggesting that the replacement cells may not achieve full functionality. To understand possible causes of this decline, we investigated effects of nephrotoxins and oxidants on the differentiation of induced pluripotent stem cells (iPSC) into proximal tubular epithelial-like cells (PTELC). Proliferation, apoptosis, senescence, and expression of oxidative defense genes were analyzed in iPSC, differentiating and differentiated cells treated with cisplatin (CisPt, up to 45 µM), cyclosporin A (CycA, up to 12 µM), and the oxidants menadione (Mena, up to 50 µM) and tert-butylhydroquinone (tBHQ, up to 50 µM). We found that differentiating cells were most sensitive to oxidants and showed increased sensitivity to CisPt, whereas all differentiation stages showed similar sensitivity to CycA. Both oxidative stress and CisPt triggered apoptosis in all differentiation stages, whereas CycA mainly induced senescence. Treatment during differentiation resulted in long-term effects on gene expression in differentiated cells. While oxidants had no effect on transport function of differentiated cells, CisPt and CycA impaired albumin uptake. Our data suggest a substantial sensitivity of differentiating cells to nephrotoxins and oxidants, an aspect that could potentially interfere with regenerative processes.

The online version contains supplementary material available at 10.1007/s00204-025-04015-1.