EXPRESSION OF EPITHELIAL-CADHERIN, ALPHA-CATENIN AND BETA-CATENIN DURING HUMAN INTRAHEPATIC BILE-DUCT DEVELOPMENT - A POSSIBLE ROLE IN BILE-DUCT MORPHOGENESIS

Background / Aims: Cell adhesion molecules play an important role in t he morphogenesis of developing organs, However, little is known about their expression during intrahepatic bile duct development. Methods: W e immunohistochemically investigated the expression of E-cadherin (E-C ad), alpha-catenin (A-Cat) and beta-catenin (B-Cat) during human intra hepatic bile duct development, using 31 fetal livers of various gestat ional ages, The developmental stages of bile ducts were classified int o the ductal plate, migrating biliary cells (remodeling stage), and im mature bile ducts (remodeled stage). Results: E-Cad was broadly and st rongly expressed in the ductal plate with a cytoplasmic pattern, heter ogeneously and weakly expressed in the migrating biliary cells with a cytoplasmic pattern, and broadly and strongly expressed in immature bi le ducts with a membranous pattern. A-Cat was broadly and strongly exp ressed pressed in the ductal plate with a membrane pattern, broadly an d moderately expressed in the migrating biliary cells with a membranou s pattern, and broadly and strongly expressed in immature bile ducts w ith a membranous pattern, In contrast, expression of B-Cat was weak or slight in the ductal plate, but B-Cat was expressed broadly and stron gly with a membranous pattern in migrating biliary cells and in immatu re bile ducts, Immature hepatocytes rarely expressed E-Cad and A-Cat, but expressed B-Cat with a membranous pattern throughout development. Conclusions: These results suggest that E-Cad, A-Cat and B-Cat are inv olved in the normal developmental morphogenesis of human intrahepatic bile ducts.