title: The biliary tree--a reservoir of multipotent stem cells.
abstract: The biliary tree is composed of intrahepatic and extrahepatic bile ducts, lined by mature epithelial cells called cholangiocytes, and contains peribiliary glands deep within the duct walls. Branch points, such as the cystic duct, perihilar and periampullar regions, contain high numbers of these glands. Peribiliary glands contain multipotent stem cells, which self-replicate and can differentiate into hepatocytes, cholangiocytes or pancreatic islets, depending on the microenvironment. Similar cells-presumably committed progenitor cells-are found in the gallbladder (which lacks peribiliary glands). The stem and progenitor cell characteristics indicate a common embryological origin for the liver, biliary tree and pancreas, which has implications for regenerative medicine as well as the pathophysiology and oncogenesis of midgut organs. This Perspectives article describes a hypothetical model of cell lineages starting in the duodenum and extending to the liver and pancreas, and thought to contribute to ongoing organogenesis throughout life.
authors.affiliation: Division of Gastroenterology, Department of Medico-Surgical Sciences and Biotechnology, Fondazione Eleonora Lorillard Spencer Cenci, Polo Pontino, Corso della Repubblica 79, 04100 Latina, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cardinale
authors.forename: Yunfang
authors.initials: Y
authors.lastname: Wang
authors.forename: Guido
authors.initials: G
authors.lastname: Carpino
authors.forename: Gemma
authors.initials: G
authors.lastname: Mendel
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Alpini
authors.forename: Eugenio
authors.initials: E
authors.lastname: Gaudio
authors.forename: Lola M
authors.initials: LM
authors.lastname: Reid
authors.forename: Domenico
authors.initials: D
authors.lastname: Alvaro
mesh_terms: D000818:Animals; D001659:Biliary Tract / Q000166:cytology*; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D004386:Duodenum / Q000166:cytology; D005704:Gallbladder / Q000166:cytology; D005770:Gastrointestinal Neoplasms / Q000473:pathology / Q000503:physiopathology; D022781:Hepatocytes / Q000166:cytology*; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology; D039902:Multipotent Stem Cells / Q000502:physiology*; D044968:Regenerative Medicine / Q000639:trends; D055153:Stem Cell Niche / Q000502:physiology*