title: High-ratio differentiation of embryonic stem cells into hepatocytes in vitro.
abstract: OBJECTIVE
  To date, in differentiating system of embryonic stem (ES) cells into hepatocytes, hepatic differentiation ratio was still not shown. Here, after investigating hepatic differentiation from ES cells, we determined the differentiation ratios of hepatocytes and studied how to improve the ratios in ES cell differentiating system.
  
  
  METHODS
  Embryonic bodies (EBs) formed from ES cells for 5 days were plated onto culture dishes and some growth factors were added into medium for hepatic differentiation. Expressions of hepatic genes and proteins were analysed using reverse transcriptase-polymerase chain reaction, immunocytochemistry (ICC) and radioimmunoassay. The relative counts of hepatocyte-like cells among all EBs cells were analysed by flow cytometry by which hepatic differentiation ratios were determined. Then, we observed the spatial distribution of ICC-positive cells in EB cells cluster and isolated the cells of positive areas in other EBs clusters without ICC examined. At last, isolated cells were re-cultured with previous condition and hepatic differentiation ratios were also determined.
  
  
  RESULTS
  The hepatic genes and proteins were, respectively, expressed in cytoplasm. Hepatic differentiation ratio was first determined at day 11 to be 12.1% and the level reached maximum to be 33.4% at day 21. In isolated cells culture system, hepatic genes and proteins expressed stronger than that expressed in EBs cluster and hepatic differentiation ratio was got to 72.6% at day 21.
  
  
  CONCLUSIONS
  Isolating hepatocyte-like cells from EBs cell cluster and re-culturing them could produce hepatocytes with high differentiation ratio. This culture system may produce a new source of cell types for hepatocytes replacement therapies in hepatic failure.
authors.affiliation: College of Life Science and Technology, Jinan University, Guangzhou, China.
authors.forename: An-Bin
authors.initials: AB
authors.lastname: Hu
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Cai
authors.forename: Qi-Chang
authors.initials: QC
authors.lastname: Zheng
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: He
authors.forename: Yu
authors.initials: Y
authors.lastname: Shan
authors.forename: Yun-Long
authors.initials: YL
authors.lastname: Pan
authors.forename: Gu-Cheng
authors.initials: GC
authors.lastname: Zeng
authors.forename: An
authors.initials: A
authors.lastname: Hong
authors.forename: Yun
authors.initials: Y
authors.lastname: Dai
authors.forename: Ling-Song
authors.initials: LS
authors.lastname: Li
mesh_terms: D000418:Albumins / Q000032:analysis; D000818:Animals; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D015870:Gene Expression; D022781:Hepatocytes / Q000166:cytology*; D007150:Immunohistochemistry; D008099:Liver / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011506:Proteins / Q000378:metabolism; D011863:Radioimmunoassay; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology*; D014508:Urea / Q000032:analysis
chemical_list: D000418:Albumins; D003470:Culture Media; D011506:Proteins; D014508:Urea