title: Enrichment of hepatocytes differentiated from mouse embryonic stem cells as a transplantable source.
abstract: BACKGROUND
  We previously reported that hepatocytes can be differentiated from embryonic stem (ES) cells by way of embryoid body (EB) formation and are transplantable into the mouse liver. However, the transplantation of EB-derived cells frequently resulted in teratoma formation in the recipient liver. In the present study, we eliminated the tumorigenic cells from EB outgrowths and examined the effects of enriched ES-cell-derived hepatocyte transplantation into an injured liver.
  
  
  METHODS
  On day 15 in culture, the EBs were partially disaggregated and subcultured. Hepatocytes in the subcultured cells were examined by the expression of hepatocyte markers. Undifferentiated cells contaminating in the EB-derived cells were eliminated by Percoll discontinuous gradient centrifugation. Furthermore, undifferentiated cells, endothelial cells, and macrophages were eliminated by magnetic cell sorting using platelet/endothelial cell adhesion molecule (PECAM)-1 and Mac-1 antibodies. These enriched ES-cell-derived hepatocytes were then transplanted into the injured mouse liver.
  
  
  RESULTS
  Percoll centrifugation and PECAM-1 antibodies eliminated the undifferentiated cells expressing Oct-3/4 from the EB-derived cells. ES-cell-derived hepatocytes showed expression of liver-related genes, synthesis of urea and glycogen, and structural characteristics during subculture. A transplantation study showed that the enriched ES-cell-derived hepatocytes integrated into the injured mouse liver and produced no teratomas. When the ES-cell-derived hepatocytes were transplanted into a CCl4-injured liver, the liver function was subsequently improved.
  
  
  CONCLUSIONS
  Functional hepatocytes can be differentiated from mouse ES cells by way of EB formation. The elimination of undifferentiated cells from the EBs provides transplantable cells for liver failure without tumorigenicity.
authors.affiliation: Department of Hepato-Biliary-Pancreatic Surgery, Graduate School of Medicine and Dentistry, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kumashiro
authors.forename: Kinji
authors.initials: K
authors.lastname: Asahina
authors.forename: Rie
authors.initials: R
authors.lastname: Ozeki
authors.forename: Keiko
authors.initials: K
authors.lastname: Shimizu-Saito
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Kida
authors.forename: Kouji
authors.initials: K
authors.lastname: Inoue
authors.forename: Michinari
authors.initials: M
authors.lastname: Kaneko
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Sato
authors.forename: Kenichi
authors.initials: K
authors.lastname: Teramoto
authors.forename: Shigeki
authors.initials: S
authors.lastname: Arii
authors.forename: Hirobumi
authors.initials: H
authors.lastname: Teraoka
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D022781:Hepatocytes / Q000166:cytology / Q000637:transplantation*; D051379:Mice; D008810:Mice, Inbred C57BL; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000502:physiology; D013234:Stem Cells / Q000166:cytology*
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1