Celiac patient iPSC can be differentiated into mature and functional small bowel mucosal epithelium

Only few celiac patient-derived small intestinal epithelial in vitro models are available, and from those the patient small intestinal biopsies are short-lived, and the enteroids from patient iPSC- or intestinal stem cells form closed structures which are not easily accessible from the luminal, food ingesting side. Thus, we aimed to set-up a celiac patient iPS-cell -derived intestinal epithelial cell (SIEC) based two-dimensional (2D) in vitro model, accessible from both sides of the culture.
Celiac and control iPSCs were differentiated and matured in 2D sequentially towards definitive (DE) endoderm, posterior definitive endoderm (PDE), and finally SIECs. The differentiation and maturation status were analyzed after each maturation step with qRT-PCR and immunofluorescence labelling using maturation stage specific genes/ proteins, e.g., for DE SOX17, for PDE Cdx2, and for SIECs the enterocyte-specific PEPT1. Functionality of matured SIECs was evaluated measuring the activity of PEPT1-transporter essential for food ingestion, and activity cytochrome 3A4 (CYP3A4), essential for clearance of toxic substances.
The celiac iPSCs exhibited similar capacity to differentiate towards DE, PDE and SIEC as the control cell lines. Celiac SIECs had the highest PEPT1 and CYP3A4 gene expression. In the functionality assays, the celiac iPSC-SIECs evinced the highest CYP3A4 activity.
These results suggest that celiac patient iPSCs can be differentiated in 2D to mature and functional SIECs, enabling upcoming in vitro studies addressing functionality of epithelial cells under biologically relevant exposures. Moreover, in future this 2D iPSC-SIEC model can be exploited as celiac small intestinal epithelial in vitro model.