https://pubmed.ncbi.nlm.nih.gov/34392560/ Biliary atresia

Hepatology. 2021 Aug 15.
doi: 10.1002/hep.32107. Online ahead of print.

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

Surya P Amarachintha 1, Reena Mourya 1, Hiroaki Ayabe 1, Li Yang 1, Zhenhua Luo 2, Xiaofeng Li 3, Unmesha Thanekar 1, Pranavkumar Shivakumar 1 4, Jorge A Bezerra 1 4

Abstract
Background & aims: Biliary atresia is a severe inflammatory and fibrosing cholangiopathy of neonates of unknown etiology. The onset of cholestasis at birth implies a prenatal onset of liver dysfunction.

Aim: To investigate the mechanisms linked to abnormal cholangiocyte development.

Approach & results: We generated biliary organoids from liver biopsies of infants with biliary atresia and normal- and diseased-controls. Organoids emerged from biliary atresia livers and controls and grew as lumen-containing spheres with an epithelial lining of cytokeratin-19posalbuminneg SOX17neg cholangiocyte-like cells. Spheres had similar gross morphology in all three groups and expressed cholangiocyte-enriched genes. In biliary atresia, cholangiocyte-like cells lacked a basal positioning of the nucleus, expressed fewer developmental and functional markers, and displayed misorientation of cilia. They aberrantly expressed F-actin, β-catenin, and Ezrin, had low signals for the tight junction protein zonula occludens-1 (ZO-1), and displayed increased permeability as evidenced by a higher Rhodamine-123 (R123) signal inside organoids after verapamil treatment. Biliary atresia organoids had 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 (CK7, HNF1β) and functional (SSTR2, CFTR, AQP1) markers, restored polarity with improved localization of F-actin, β-catenin and ZO-1, increased CFTR function, and decreased uptake of R123.
Conclusions: 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.