[Directional differentiation of embryonic stem cells into biliary epithelium cells in vitro: an experiment with mice].
OBJECTIVE
To investigate the mechanism and regulation of differentiation from embryonic stem (ES) cells into biliary epithelium (BE) cells and to find a new source f of BE cells for liver engineering.


METHODS
ES cells of BALB/c mice (BALB/c-ES) and ES cells of mice of the line 129 (D3-ES) were cultured in the medium without LIF for 5 days with the result that embryoid bodies (EBs) were developed from the ES cells. For directional differentiation, the EBs were plated onto a 24-well gelatin-coated tissue culture dish and some growth factors, such as transforming growth factor (TGF), acid fibroblast growth factor (aFGF), hepatocyte growth factor (HGF) and epidermal growth factor (EGF) etc were added into the medium successively in the experiment group but not in the control group. The differentiation status was observed by inversion microscope dynamically. The BE cell markers, such as cytokeratin 7 (CK7), cytokeratin 19 (CK19) and gamma-glutamyltransferase (GGT) were detected by immunocytochemistry (ICC) and histochemistry.


RESULTS
After the culture for 5 days the ES cells developed into many EBs in the medium without LIF. In the EBs cells clusters, many circular structures appeared on the differentiation day 10. On the days 10 and 13 ICC, CK7 and CK19 began to be expressed respectively. GGT began to be expressed at day 10. CK7, CK19 and GGT were also expressed in the ES cells of the control group, however, appeared remarkably later.


CONCLUSIONS
ES cells can differentiate into BE cells under specific culture condition and the action of growth factors. Such ES cell differentiating system can provide BE cells and may serve as a good new source of differentiated cell types for liver engineering.
Hu
An-bin
AB
Organ Transplantation Center, First Affiliated Hospital of Sun Yet-sen University, Guangzhou 510080, China.
He
Xiao-shun
XS
Cai
Ji-ye
JY
Zheng
Qi-chang
QC
D000818:Animals; D001659:Biliary Tract / Q000166:cytology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D003470:Culture Media; D053595:Embryonic Stem Cells / Q000166:cytology*; D004847:Epithelial Cells / Q000166:cytology*; D016220:Fibroblast Growth Factor 1 / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D016212:Transforming Growth Factor beta
D003470:Culture Media; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D017228:Hepatocyte Growth Factor