title: Embryonic stem cell-derived embryoid bodies in three-dimensional culture system form hepatocyte-like cells in vitro and in vivo.
abstract: Pluripotent embryonic stem (ES) cells can be a source of hepatocytes for bioartificial livers or transplantation. In this study, embryoid bodies (EBs) were formed from ES cells cultured in polypropylene conical tubes. The EBs were then inserted into a collagen scaffold three-dimensional culture system and stimulated with exogenous growth factors and hormones to induce hepatic histogenesis. The EB-derived cells expressed liver-specific genes, and albumin-positive cells formed cord-like structures that were not present in two-dimensional monolayer culture systems. However, these albumin- positive cells were not cytokeratin 18 positive. Electron microscopy showed immature hepatocyte- like cells having tight junctions, rough endoplasmic reticulum, and intercellular canaliculi. The scaffold including EB-derived hepatocyte-like cells was transplanted into the median lobes of partially hepatectomized nude mice. After 7 and 14 days, cells positive for both albumin and cytokeratin 18 appeared in the transplant and formed clustered aggregates. Thus the collagen scaffold three-dimensional culture system and the liver regeneration environment induced hepatocyte-like cells and hepatic lobule-like aggregates from EBs. Therefore, differentiating EBs in the scaffold culture system may be useful in developing bioartificial livers, secondary livers, and as pharmaceutical models.
authors.affiliation: Department of Anatomy and Organ Technology, Shinshu University School of Medicine, Matsumoto, Japan. imatetu@sch.md.shinshu-u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Imamura
authors.forename: Li
authors.initials: L
authors.lastname: Cui
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Teng
authors.forename: Kohei
authors.initials: K
authors.lastname: Johkura
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Okouchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Asanuma
authors.forename: Naoko
authors.initials: N
authors.lastname: Ogiwara
authors.forename: Katsunori
authors.initials: K
authors.lastname: Sasaki
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology; D022781:Hepatocytes / Q000166:cytology* / Q000502:physiology / Q000637:transplantation*; D019164:Liver, Artificial; D051379:Mice; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods*