OpenTox Virtual Conference 2021 Session 7
Application of TempO-Seq transcriptomics to study temporal effects of cadmium chloride in human iPSC-derived renal proximal tubular cells
Anja Wilmes1, Pranika Singh2,3, Vidya Chandrasekaran1, Barry Hardy2, Paul Jennings1 and Thomas E. Exner4.
1Division of Molecular and Computational Toxicology, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam, The Netherlands.
2Edelweiss Connect GmbH, Technology Park Basel, Hochbergerstrasse 60C, 4057 Basel, Switzerland 3Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
4Seven Past Nine d.o.o., Hribljane 10, 1380 Cerknica, Slovenia
In the kidney, proximal tubular cells are one of the most susceptible parts of the nephron to many xenobiotics. Hence, the development and characterization of human renal proximal tubular models are of great importance. Recently, we generated a protocol to drive human-induced Pluripotent Stem Cells (iPSCs) into renal proximal tubule-like cells (PTL). PTL cells express proximal tubular-specific markers, including megalin, and show functional activity for megalin-facilitated endocytosis, P-glycoprotein efflux, and response to parathyroid hormone. Here, we have explored the utilization of PTL to a) investigate their robustness for toxicity testing and b) analyze the temporal alterations in response to exposure of the nephrotoxin cadmium chloride. iPSC-derived PTL were treated with a non-cytotoxic concentration (5 µM) cadmium chloride for up to 7 days. Samples were harvested at several time points (1h, 2h,
4h, 6h, 8h, 12h, 16h, 20h, 24h, 72h and 168h) for TempO-Seq transcriptomics. Our results demonstrated an early activation of the metal response pathway at 1h that maintained stable expression levels throughout the entire experiment. Furthermore, the Nrf2 mediated oxidative stress response pathway was activated after approximately 4h but started to decrease to baseline levels by 24h.
In summary, we could show that iPSC-derived PTL was able to capture relevant temporal alterations of cadmium chloride and may represent a novel human-relevant model for in vitro toxicity testing.
CV: Anja Wilmes completed her Ph.D. in Cell and Molecular Biology at the School of Biological Sciences at Victoria University of Wellington in New Zealand in 2008. She then started working as a PostDoc at the Medical University of Innsbruck, Austria in the Division of Physiology in the group of Prof. Jennings, where she used integrated omics to study nephrotoxicity in human proximal tubular cells. In 2013, she started working with induced pluripotent stem cells (iPSC) within the StemBANCC consortium and developed methods to drive iPSC into renal cell types, including proximal tubular cells and podocytes. In 2016, she completed her habilitation (venia docendi) in physiology with the title "Molecular investigations of chemical stress induction in the renal proximal tubule”. Since 2018, she is working as an Assistant professor at the Vrije Universiteit Amsterdam to continue her work to develop iPSC-derived cell models for toxicity testing with a focus on the development of human screening models for personalized medicine and toxicity. She is currently involved in several large consortia, including the EU projects EU-ToxRisk and RISK HUNT3R and the Dutch project VHP4Safety. Other individual projects include the replacement of Matrigel (Stiftung Set project) and the development of iPSC-models for studying mitochondria toxicity (Stiftung Pro-Care project).