Host: The Japanese Society of Toxicology
Human induced pluripotent stem cells (hiPSCs) are expected to be useful for both toxicity and pharmacokinetics evaluations of drug candidate compounds in drug discovery. For instance, the small intestine plays an important role for oral absorption of drugs, and the use of human primary intestinal epithelial cells (IECs) may be considered in drug discovery. However, there is an issue in securing of stable acquisition of functional human primary IECs. If the functional human IECs is obtained from hiPSCs, the issue will be resolved. Therefore, in this study, I aimed to generate functional IECs from hiPSCs using the three-dimensional differentiation procedure1) mimicked the in vivo environment.
HiPSCs were induced to differentiate into IECs via definitive endodermal and midgut/hindgut cells by mimicking the intestinal development. The midgut/hindgut cells were cultured by three-dimensional method, and then intestinal organoids including IECs was obtained. Most of intestinal organoids were expressed an IECs marker protein (villin), however, the surrounding cells of intestinal organoids were expressed a mesenchymal cell maker protein (vimentin). So, intestinal organoids were dissociated into single cells and IECs derived from hiPSCs (hiPSC-IECs) were enriched by magnetic-activated cell sorting. After hiPSC-IECs were incubated with a terfenadine (CYP3A/CYP2J2 substrate) or midazolam (CYP3A substrate), the metabolites were generated, respectively. The results suggest that hiPSC-IECs have CYP3A/2J2 enzymatic activity. Monolayered hiPSC-IECs expressed tight-junction marker proteins (Occludin and ZO-1), indicating hiPSC-IECs have intestinal barrier function. Therefore, hiPSC-IECs can be beneficial for the exploration of drug candidate compounds based on oral absorption character.
In addition, I will introduce the outcome using hiPSC-IECs in research area of drug metabolism and pharmacokinetics in Shionogi & Co., Ltd. and the literatures regarding characteristic of intestinal organoids derived from hiPSCs and resent toxicity study using intestinal organoids. Based on knowledge from these literatures, I would like to discuss application of intestinal organoids for evaluation of toxicity in drug discovery.
Reference：
1)Spence. JR., Wells, JM., et al. Nature, 470, 105-109, 2011
