title: Liver Progenitors Isolated from Adult Healthy Mouse Liver Efficiently Differentiate to Functional Hepatocytes In Vitro and Repopulate Liver Tissue.
abstract: It has been proposed that tissue stem cells supply multiple epithelial cells in mature tissues and organs. However, it is unclear whether tissue stem cells generally contribute to cellular turnover in normal healthy organs. Here, we show that liver progenitors distinct from bipotent liver stem/progenitor cells (LPCs) persistently exist in mouse livers and potentially contribute to tissue maintenance. We found that, in addition to LPCs isolated as EpCAM+cells, liver progenitors were enriched in CD45-TER119-CD31-EpCAM-ICAM-1+fraction isolated from late-fetal and postnatal livers. ICAM-1+liver progenitors were abundant by 4 weeks (4W) after birth. Although their number decreased with age, ICAM-1+liver progenitors existed in livers beyond that stage. We established liver progenitor clones derived from ICAM-1+cells between 1 and 20W and found that those clones efficiently differentiated into mature hepatocytes (MHs), which secreted albumin, eliminated ammonium ion, stored glycogen, and showed cytochrome P450 activity. Even after long-term culture, those clones kept potential to differentiate to MHs. When ICAM-1+clones were transplanted into nude mice after retrorsine treatment and 70% partial hepatectomy, donor cells were incorporated into liver plates and expressed hepatocyte nuclear factor 4α, CCAAT/enhancer binding protein α, and carbamoylphosphate synthetase I. Moreover, after short-term treatment with oncostatin M, ICAM-1+clones could efficiently repopulate the recipient liver tissues. Our results indicate that liver progenitors that can efficiently differentiate to MHs exist in normal adult livers. Those liver progenitors could be an important source of new MHs for tissue maintenance and repair in vivo, and for regenerative medicine ex vivo. Stem Cells 2016;34:2889-2901.
authors.affiliation: Department of Tissue Development and Regeneration, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanimizu
authors.affiliation: Department of Tissue Development and Regeneration, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Ichinohe
authors.affiliation: Department of Tissue Development and Regeneration, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.|Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishii
authors.affiliation: Department of Tissue Development and Regeneration, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kino
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Mizuguchi
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.|Department of Surgery, JR Sapporo Hospital, Sapporo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Department of Tissue Development and Regeneration, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Mitaka
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002999:Clone Cells; D000071858:Epithelial Cell Adhesion Molecule / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000254:growth & development; D008810:Mice, Inbred C57BL; D053683:Oncostatin M / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000071858:Epithelial Cell Adhesion Molecule; D053683:Oncostatin M; D018799:Intercellular Adhesion Molecule-1
keywords: Cell transplantation; Committed progenitors; Mature hepatocytes; Metabolic functions; Tissue stem/progenitor cells