MedicalResearch.com Interview with:
Daniele Zink PhD
Institute of Bioengineering and Nanotechnology
Singapore
Medical Research: What is the background for this study?
Dr. Zink: The kidney is one of the main target organs for toxic effects of drugs, environmental toxicants and other compounds. Renal proximal tubular cells (PTCs) are frequently affected due to their roles in compound transport and metabolism. Validated and accepted assays for the prediction of PTC toxicity in humans currently do not exist. Recently, we have developed the first and only pre-validated assays for the accurate prediction of PTC toxicity in humans
1, 2. This previous work was performed with human primary renal proximal tubular cells (HPTCs) or embryonic stem cell-derived HPTC-like cells. HPTCs are associated with a variety of issues that apply to all kinds of primary cells, such as cell sourcing problems, inter-donor variability and limited proliferative capacity. Embryonic stem cell-derived cells are associated with ethical and legal issues. These are the main reasons why induced pluripotent stem cell (iPSC)-derived cells are currently a favored cell source for
in vitro toxicology and other applications.
The problem was that stem cell-based approaches were not well-established with respect to the kidney. Recently, the group of IBN Executive Director Prof. Jackie Y. Ying developed the first protocol for differentiating embryonic stem cells into HPTC-like cells, and my group has contributed to characterizing these cells and publishing the results
3. In the work published in
Scientific Reports ,
4we have applied a modified version of this protocol to iPSCs. In this way, we have established the simplest and fastest protocol ever for differentiating iPSCs into HPTC-like cells. The cells can be used for downstream applications after just 8 days of differentiation. These cells can also be applied directly without further purification due to their high purity of > 90%.
By using these cells, we have developed the first and only iPSC-based model for the prediction of PTC toxicity in humans. This was achieved by combining our iPSC-based differentiation protocol with our previously developed assay based on interleukin (IL)6/IL8 induction
1, 2 and machine learning methods
5. Machine learning methods were used for data analysis and for determining the predictive performance of the assay. The test accuracy of the predictive iPSC-based model is 87%, and the assay is suitable for correctly identifying injury mechanisms and compound-induced cellular pathways.
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