The porcine urinary bladder functions as an innovative in vitro model for the investigation of human pancreatic development and carcinogenesis in a pluripotent stem cell-based approach

Introduction Human pluripotent stem cell (hPSC)-derived pancreatic duct-like organoids (PDLOs) resemble pancreatic ducts in vitro. Yet, only orthotopic transplantation into murine hosts enabled us to investigate the stroma-epithelium crosstalk so far. The de-epithelialized porcine urinary bladder provides a revolutionary in vitro system to investigate cellular crosstalk. Within this project, we (i) successfully implemented the culture of pancreatic progenitor cells (PPs) as well as PDLOs on the porcine urinary bladder to study (ii) the maturation of PPs in a complex stromal environment, (iii) the interaction with an extracellular matrix, and stromal compartment and (iv) to investigate the early cellular response to oncogenic events in PDLOs.

Aim We hypothesized that pancreatic differentiation and carcinogenesis studies require a stromal component. After identifying the easy-accessible porcine urinary bladder, we aimed to demonstrate that the urinary bladder can provide an ideal environment, superior to currently available systems, to study maturation and dysplasia in the pancreas in vitro.

Material and methods Porcine urinary bladders were obtained from the local abattoir and de-epithelialized to perform subsequent seeding of PPs and PDLOs.

Results HPSC-derived PPs were cultivated on the porcine urinary bladder, leading to pancreatic ducts and endocrine cells. Morphology and marker expression proofed ductal (KRT19, MUC1) and endocrine (Chromogranin A) identity. Cultivation of previously pre-mature PDLOs lead to superior maturation (KRT7, CFTR, MUC1) compared to conventional in vitro culture. Activation of Piggy-Bac transferred doxycycline-inducible KRAS^G12D in PDLOs on the porcine bladder induced significant dysplasia in PDLOs (CA19-9, MUC1).

Conclusion The de-epithelialized porcine urinary bladder presents a novel and highly promising in vitro model to study hPSC-based pancreatic differentiation and early steps in pancreatic carcinogenesis. It enables performing interaction studies of hPSC-derived epithelial pancreatic cells with the extracellular matrix and stromal compartment. It thus provides a revolutionary in vitro model to currently available cell culture systems by simultaneously not requiring the conduction of in vivo experiments.

Publication History

Article published online:
07 September 2021