Hematopoiesis-dependent expression of CD44 in murine hepatic progenitor cells.
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.
Ohata
Shinya
S
Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
Nawa
Makiko
M
Kasama
Takeshi
T
Yamasaki
Tokiwa
T
Sawanobori
Kenji
K
Hata
Shoji
S
Nakamura
Takashi
T
Asaoka
Yoichi
Y
Watanabe
Toshio
T
Okamoto
Hitoshi
H
Hara
Takahiko
T
Terai
Shuji
S
Sakaida
Isao
I
Katada
Toshiaki
T
Nishina
Hiroshi
H
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*
D018960:Hyaluronan Receptors