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Human Fetal Liver (human + fetal_liver)
Selected AbstractsCD34+ cells derived from fetal liver contained a high proportion of immature megakaryocytic progenitor cellsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2000Dong-Chu Ma Abstract: Endoreplication and maturation of the megakaryocyte (MK) may be retarded or delayed during ontogenesis. In this study, CD34+ cells were isolated from both human fetal liver and adult bone marrow and incubated with thrombopoietin (TPO). The cell number, morphological characteristics, platelet-associated antigen phenotype, maturation stage and DNA ploidy of CD41+cells were examined from day 0 to day 12 in culture. 1) TPO stimulated the proliferation of fetal liver (FL)-derived CD34+ cells with a mean 73.14-fold increase of CD41+ cells after 12 d in culture. Adult BM-derived CD34+ cells increased only slightly, with a mean 8.18-fold increase of CD41+ cells. 2) Although the membrane phenotype of both FL CD34+ -derived MKs and BM CD34+ -derived MKs analyzed with CD41a, CD42a, CD61 and CD34 were similar, all FL CD34+ -derived MKs were in maturation stage I and II and in low ploidy (<4N) class. By comparison, BM CD34+ MKs possessed 15% MKs in maturation stage III and IV and with 23% MKs in high ploidy class (>4N). 3) Most of cultured FL-derived CD34+ cells did not have a well developed demarcation system (DM) and numerous ,-granules after 12 d incubation. von Willebrand factor (vWF) appeared earlier on the cultured BM-derived CD34+ cells than on FL-derived CD34+ cells. 4) The expression of both cyclin E and cyclin B1 progressively increased in FL CD34+cells induced by TPO during 12 d in culture. 5) The expression of cyclin D1 gradually decreased in FL CD34+cells induced by TPO over 12 d incubation. 6) Immunocytochemical analysis showed that cyclin D3 was detected only in cytoplasm of cultured FL-derived CD34+ cells, whereas in both cytoplasm and nuclei of cultured BM-derived CD34+ cells. These data suggest that FL-derived CD34+ cells contain a high proportion of immature megakaryocytic progenitor cells. It further suggests that TPO can push these progenitor cells into proliferation by upregulating the expression of cyclins B1 and E, and drive a high proportion of cells into megakaryocytic lineage. [source] Isolation and characterization of epithelial progenitor cells from human fetal liverHEPATOLOGY RESEARCH, Issue 1 2008Yi-Nan Liu Aim:, Hepatic progenitor cells can serve as an alternative source of hepatocytes for the treatment of liver diseases. Methods:, We isolated and expanded the epithelial progenitor cells (EPC) from the human fetal liver and investigated the differentiation of EPC into hepatic cells by fluorescence-activated cell sorter (FACS), real-time polymerase chain reaction (PCR), immunofluorescence assay, western blotting, and periodic acid,Schiff staining. Results:, Isolated EPC possessed highly proliferative ability and subpassaged for more than 25 passages. Real-time PCR showed that EPC expressed liver epithelial markers (cytokeratin [CK]8 and CK18) and biliary-specific markers (CK7 and CK19). FACS analysis indicated that these cells were positive for CD117, CD147, CD90, CD44, human leucocyte antigen class I and CD71, but negative for CD34 and CD45. The EPCpossessed multipotential indicated by differentiating into osteoblasts and adipocytes; when subjected to the hepatic differentiation condition, EPC could be induced to hepatocyte-like cells, which expressed albumin, alpha-fetoprotein, and CK18 proteins. Two months after EPC transplantation, we observed that the grafted cells differentiated into hepatocyte-like cells and there was no observable tumor mass. Conclusion:, We have isolated and characterized the human fetal liver-derived EPC and these cells may serve as an ideal cell source for cell-replacement therapy of diseased livers. [source] Tyrosine aminotransferase and gamma-glutamyl transferase activity in human fetal hepatocyte primary cultures under proliferative conditionsCELL BIOCHEMISTRY AND FUNCTION, Issue 2 2004Khaja K. Rehman Abstract The ontogeny of gamma-glutamyl transferase (GGTase; E.C.2.3.2.2) and tyrosine aminotransferase (TAT; E.C.2.6.1.5) activities in 14 to 36 weeks gestational and neonatal hepatocytes during development of human fetal liver was studied. Subsequently, 20,24 weeks gestational hepatocytes were cultured in media supplemented with epidermal growth factor (EGF) and insulin with or without glucagon and dexamethasone to investigate the proliferation and differentiation of fetal hepatocyte in vitro using GGTase and TAT as biochemical markers. During the development of the liver, the activity of GGTase increased continuously from the first trimester through the third trimester and decreased (p,<,0.001) in neonates. A low basal level of TAT activity was seen only during the third trimester, which then increased significantly (p,<,0.001) in neonates. Fetal hepatocytes, in the presence of EGF and insulin, undergo proliferation from the fourth to 10th day with an increase in cell number (p,<,0.001) and concomitant increase (p,<,0.001) in GGTase activity. As the cells attain confluence, enzyme activity decreased significantly (p,<,0.001) from the 10th to 16th day. Maximal TAT activity (p,<,0.001) was observed at 48,h of culture, which decreased, but not significantly, during cell proliferation and the enzyme activity was regained as the cultures attained confluence. Furthermore, TAT activity was induced synergistically (p<0.001) in the presence of glucagon and dexamethasone, while GGTase was inhibited (p<0.001). These results indicate that GGTase increases with proliferation, whereas TAT, once it has been expressed, is not suppressed during cell proliferation. In conclusion, human fetal hepatocytes undergo enzymic differentiation by 48,h of culture, and proliferate with an increase in GGTase in the presence of growth factors with maintenance of differentiated status up to the studied 16 days of culture. Copyright © 2003 John Wiley & Sons, Ltd. [source] | ||||||||||