title: Low serum concentration facilitates the differentiation of hepatic progenitor cells.
abstract: OBJECTIVE
  To investigate the effect of serum culture conditions on the differentiation of hepatic progenitor cells (HPCs) in vitro.
  
  
  METHODS
  This study was conducted at the Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing, China from August 2009 to June 2010. Differentiation of HPCs was induced with dexamethasone, hepatic growth factor, and fibroblast growth factor-4 in 10% fetal bovine serum (FBS), 2% FBS, 2% horse serum (HS) conditions. First, we investigated the indirect synthesis of albumin by the albumin promoter-driven Gaussia luciferase assay, and cell proliferation by cell counting. Then, we performed reverse transcriptase-polymerase chain reaction and immunofluorescence to detect hepatic related markers Delta-like protein (DLK), cytokeratin 18 (CK18), tyrosine aminotransferase (TAT), albumin (ALB), a-fetoprotein (AFP), and glucuronosyltransferase 1A (UGT1A). Lastly, we used indocyanine green (ICG) uptake assay and periodic acid-Schiff (PAS) staining to determine the function of induced hepatocytes.
  
  
  RESULTS
  The proliferation of HPCs was inhibited in 2% serum culture. Induced HPCs in 2% serum exhibited higher expression of ALB, CK18, UGT1A, and TAT, whereas lower expression of DLK and AFP, compared with 10% FBS. Interestingly, 2% serum culture improved ICG uptake function, but repressed PAS staining of induced HPCs. Generally, 2% HS was better at inducing mature hepatic markers and the function of HPCs than 2% FBS.
  
  
  CONCLUSIONS
  Two percent low serum concentration conditions, especially 2% HS, improve the hepatic differentiation of HPCs, and PAS staining may not be used in induction testing of low serum concentrations.
authors.affiliation: Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: He
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Gong
authors.forename: Jia-Yi
authors.initials: JY
authors.lastname: Huang
authors.forename: Ni
authors.initials: N
authors.lastname: Tang
authors.forename: Tao
authors.initials: T
authors.lastname: Feng
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Wei
authors.forename: Tong-Chuan
authors.initials: TC
authors.lastname: He
authors.forename: Yang
authors.initials: Y
authors.lastname: Bi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002135:Calcium-Binding Proteins; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D022781:Hepatocytes / Q000166:cytology* / Q000378:metabolism; D006736:Horses; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D053538:Keratin-18 / Q000378:metabolism; D051379:Mice; D044967:Serum; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014444:Tyrosine Transaminase / Q000378:metabolism
chemical_list: D015415:Biomarkers; D002135:Calcium-Binding Proteins; C512925:Dlk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D053538:Keratin-18; D014444:Tyrosine Transaminase