Expansion of biliary epithelial cells (BECs) during ductular reaction (DR) is observed in liver diseases including cystic fibrosis (CF), and associated with inflammation and fibrosis, albeit without complete understanding of underlying mechanism. Using two different genetic knockouts of β-catenin, one with ß-catenin loss is hepatocytes and BECs (KO1), and another with loss in only hepatocytes (KO2), we demonstrate disparate long-term repair after an initial injury by 2-week choline-deficient ethionine supplemented diet. KO2 show gradual liver repopulation with BEC-derived β-cateninpositive hepatocytes, and resolution of injury. KO1 showed persistent loss of β-catenin, NF-κB activation in BECs, progressive DR and fibrosis, reminiscent of Cystic fibrosis (CF) histology. We identify interactions of β-catenin, NFκB and Cystic fibrosis transmembranous conductance regulator (CFTR) in BECs. Loss of CFTR or β-catenin led to NF-κB activation, DR and inflammation. Thus, we report novel β-catenin-NFκBCFTR interactome in BECs, and its disruption may contribute to hepatic pathology of CF.
YAP, but Not RSPO-LGR4/5, Signaling in Biliary Epithelial Cells Promotes a Ductular Reaction in Response to Liver Injury
