title: Hematopoiesis-dependent expression of CD44 in murine hepatic progenitor cells.
abstract: The fetal liver serves as the predominant hematopoietic organ until birth. However, the mechanisms underlying this link between hematopoiesis and hepatogenesis are unclear. Previously, we reported the isolation of a monoclonal antibody (anti-Liv8) that specifically recognizes an antigen (Liv8) present in murine fetal livers at embryonic day 11.5 (E11.5). Liv8 is a cell surface molecule expressed by hematopoietic cells in both fetal liver and adult mouse bone marrow. Here, we report that Liv8 is also transiently expressed by hepatoblasts at E11.5. Using protein purification and mass spectrometry, we have identified Liv8 as the CD44 protein. Interestingly, the expression of Liv8/CD44 in fetal liver was completely lost in AML1(-/-) murine embryos, which lack definitive hematopoiesis. These results show that hepatoblasts change from Liv8/CD44-negative to Liv8/CD44-positive status in a hematopoiesis-dependent manner by E11.5, and indicate that Liv8/CD44 expression is an important link between hematopoiesis and hepatogenesis during fetal liver development.
authors.affiliation: Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Ohata
authors.forename: Makiko
authors.initials: M
authors.lastname: Nawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kasama
authors.forename: Tokiwa
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Sawanobori
authors.forename: Shoji
authors.initials: S
authors.lastname: Hata
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Toshio
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamoto
authors.forename: Takahiko
authors.initials: T
authors.lastname: Hara
authors.forename: Shuji
authors.initials: S
authors.lastname: Terai
authors.forename: Isao
authors.initials: I
authors.lastname: Sakaida
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Katada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishina
mesh_terms: D000818:Animals; D006410:Hematopoiesis; D022781:Hepatocytes / Q000378:metabolism*; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D008099:Liver / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D018960:Hyaluronan Receptors