title: Maturation of fetal hepatocytes in vitro by extracellular matrices and oncostatin M: induction of tryptophan oxygenase.
abstract: Previously, we described that embryonic day 14.5 (E14.5) mouse fetal hepatocytes differentiate to express tyrosine amino transferase (TAT) and glucose-6-phosphatase, which are expressed in the perinatal liver, in response to oncostatin M (OSM) or in high-cell-density culture. However, under such conditions, fetal hepatic cells failed to express genes for adult liver-specific enzymes, such as tryptophan oxygenase (TO). Although phenobarbital (PB) and dimethylsulfoxide (DMSO) have been known to maintain the functions of adult hepatocytes in vitro, they failed to induce TO expression in fetal hepatic cells. Thus far, no system has been developed that reproduces terminal differentiation of fetal hepatocytes in vitro. Here, we describe that extracellular matrices derived from Engelbreth-Holm-Swarm sarcoma (EHS) in combination with OSM or high-cell-density culture induced expression of TO as well as cytochrome P450 genes that are involved in detoxification. However, EHS alone was insufficient to induce expression of TO, although it induced TAT expression in fetal hepatocytes. In addition, high-density culture further augmented differentiation. In conclusion, the combination of signals by cytokines, cell-cell contact, and cell-matrix interaction is required for induction of adult liver functions in fetal hepatocytes in vitro. This primary culture system will be useful for studying the mechanism of liver development.
authors.affiliation: Stem Cell Regulation Project, Kanagawa Academy of Science and Technology, Miyamae-ku, Kawasaki, Kanagawa, Japan.
authors.forename: Akihide
authors.initials: A
authors.lastname: Kamiya
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Kojima
authors.forename: Taisei
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sakai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyaijma
mesh_terms: D000818:Animals; D000906:Antibodies; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005109:Extracellular Matrix / Q000201:enzymology*; D005333:Fetus / Q000166:cytology; D016166:Free Radical Scavengers / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D006131:Growth Inhibitors / Q000494:pharmacology*; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D066298:In Vitro Techniques; D019012:Integrin beta1 / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053683:Oncostatin M; D010455:Peptides / Q000494:pharmacology*; D010634:Phenobarbital / Q000494:pharmacology; D012513:Sarcoma, Experimental; D015398:Signal Transduction / Q000502:physiology; D014366:Tryptophan Oxygenase / Q000235:genetics / Q000378:metabolism*
chemical_list: D000906:Antibodies; D018691:Excitatory Amino Acid Antagonists; D016166:Free Radical Scavengers; D006131:Growth Inhibitors; D019012:Integrin beta1; C508352:Osm protein, mouse; D010455:Peptides; D053683:Oncostatin M; D003577:Cytochrome P-450 Enzyme System; D014366:Tryptophan Oxygenase; D004121:Dimethyl Sulfoxide; D010634:Phenobarbital