Biliary organoids uncover delayed epithelial development and barrier function in biliary atresia.

Background: RNASeq was performed on organoids derived from livers of normal healthy donors and patients with biliary atresia to characterize transcriptomic signatures. Methods: Organoids generated from livers of normal healthy donors and patients with biliary atresia were cultured either in expansion (undifferentiated: 3 NCOs and 11 BACOs) or differentiation medium (differentiated: 3 BACOs). Liver tissues obtained from deceased-donor subjects served as normal controls (N=3). Total RNA was isolated from organoids and liver biopsy tissue specimens. Results: Organoids from patients with biliary atresia showed abnormal cell polarity, loss of tight junctions, increased permeability and decreased expression of genes related to epidermal growth factor (EGF)- and fibroblast growth factor 2 (FGF2)-signaling. When treated with EGF+FGF2, biliary atresia organoids expressed differentiation and functional markers with restored cell polarity. Conclusion: Organoids from biliary atresia are viable and have evidence of halted epithelial development. The induction of developmental markers, improved cell‐cell junction, and decreased epithelial permeability by EGF and FGF2 identifies potential strategies to promote epithelial maturation and function. RNA-seq was performed using organoids derived from livers of normal donors and patients with biliary atresia. Liver tissues from normal donors were also subjected to RNA-sequencing.