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. Overall design: 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.