IKAI Iwao KYOTO UNIVERSITY, Department of Gastroenterological Surgery, Lecturer, 医学研究科, 講師 (60263084)
中辻 憲夫 京都大学, 再生医科学研究所, 教授 (80237312)
山岡 義生 京都大学, 医学研究所, 教授 (90089102)
|Budget Amount *help
¥13,900,000 (Direct Cost : ¥13,900,000)
Fiscal Year 2003 : ¥7,400,000 (Direct Cost : ¥7,400,000)
Fiscal Year 2002 : ¥6,500,000 (Direct Cost : ¥6,500,000)
Previously, we have isolated hepatic stem/progenitor cells from adult liver tissue of the transgenic mouse, in which green fluorescent protein was expressed highly in endodermal cells. Then, we have investigated the specific surface marker genes for hepatic stem/progenitor cells. Consequently, we identified several genes for hepatic stem/progenitor cells: In order to determine the specificity of these genes including several EST clones for hepatic stem/progenitor cells, we are now going to verify the difference of gene and also protein product expression between hepatic stem/progenitor cells and mature adult hepatocytes. Futhermore, we are going to investigate the human homologues of these genes subcloned into plasmid after PCR amplification. On the other hand, we confirmed the fact that human hepatic stem/progenitor cells were obtained from human adult liver tissue using the same method for fetal and adult mouse hepatic stem/progenitor cells as we previously reported (Yasuchika K, et al. Hepatology, 2002)(Azuma H, et al. Hepatology, 2003). During further profiling for the specific surface marker expression of mouse hepatic stem/progenitor cells-enriched fraction, we also identified that Thy1-positive mesenchymal cells contained in the mouse fetal liver promoted the maturation of CD49f-positive hepatic stem/progenitor cells in vitro (Hoppo T, et al. Hepatology, 2004, in press). It is anticipated that this kind of mesenchymal cells or recombinant proteins associated with them would be necessary for the maturation of human hepatic stem/progenitor cells into functional adult hepatocytes in vitro. Therefore, we are now executing further investigation for the characteristics of these mesenchymal cells. As described above, we are going to reveal the specific marker genes and also establish the differentiation system for hepatic stem progenitor cells.