Stem/Progenitor Cell Niches Involved in Hepatic and Biliary Regeneration

Figure 2

Peribiliary glands (PBGs) are the niche of Biliary Tree Stem Cells (BTSCs). (a) PBGs are glands located within the lamina propria of the extrahepatic and large intrahepatic bile ducts (yellow arrows). PBG distribution varies along the biliary tree, and PBGs are mostly found in the hepatopancreatic ampulla (white stars) and in branching sites of the biliary tree. PBGs are not present in gallbladder, but a BTSC-like compartment is located in the epithelial crypts (gray arrows). PBGs are composed of Sox9+ BTSCs. (b) Primary sclerosing cholangitis is characterized by the inflammation of duct walls (red asterisks) and PBG hyperplasia (yellow arrows). PBGs are involved in biliary fibrosis and are surrounded by α-smooth muscle actin (α-SMA) fibrogenetic cells (white asterisks). Immunohistochemistry for Epithelial Cell Adhesion Molecule (EpCAM) was counterstained with Periodic acid-Schiff (PAS). Immunofluorescence for cytokeratin (CK) 7, Sox9, and α-SMA are included.

(a)

(b)