title: In vitro differentiation of liver progenitor cells derived from healthy dog livers.
abstract: Naturally occurring liver disease in dogs resemble human liver disease in great detail; including the activation of liver progenitor cells (LPC) in acute and chronic liver disease. The aim of the present study was to isolate, culture, and characterize progenitor cells derived from healthy mature dog livers. A nonparenchymal cell fraction enriched with small hepatocytes was isolated and cultured in Hepatozyme-serum-free media (SFM) to stimulate the growth of colony-forming small epithelial cells. After 2 weeks of culturing, clonal expansion of keratin 7 (K7) immunopositive small cells with a large nucleus/cytoplasm ratio emerged in the hepatocyte monolayer. These colonies expressed genes of several hepatocyte (CYP1A1, ALB, and KRT18), cholangiocyte/LPC (KRT7 and KRT19), and progenitor cell markers (alpha-fetoprotein, CD44, prominin1, KIT, THY1, and neural cell adhesion molecule 1), indicating their immature and bipotential nature. Gene-expression profiles indicated a more pronounced hepatic differentiation in Hepatozyme-SFM compared to William's Medium E (WME). Furthermore, colony-forming cells differentiated toward intermediate hepatocyte-like cells with a more pronounced membranous K7 immunostaining. In conclusion, colony-forming small epithelial cells in long-term canine liver cell cultures express LPC markers and have differentiating capacities. These cells may therefore be considered as progenitor cells of the liver.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, The Netherlands. b.arends@uu.nl
authors.forename: Brigitte
authors.initials: B
authors.lastname: Arends
authors.forename: Bart
authors.initials: B
authors.lastname: Spee
authors.forename: Baukje A
authors.initials: BA
authors.lastname: Schotanus
authors.forename: Tania
authors.initials: T
authors.lastname: Roskams
authors.forename: Ted S G A M
authors.initials: TS
authors.lastname: van den Ingh
authors.forename: Louis C
authors.initials: LC
authors.lastname: Penning
authors.forename: Jan
authors.initials: J
authors.lastname: Rothuizen
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004285:Dogs; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006262:Health; D007150:Immunohistochemistry; D053552:Keratin-7 / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D053552:Keratin-7