title: [In vitro differentiation of rat amniotic fluid-derived mesenchymal stem cells into type II alveolar epithelial cells].
abstract: OBJECTIVE
  To explore the in vitro differentiation of rat amniotic fluid-derived mesenchymal stem cells (AF-MSCs) into type II alveolar epithelial cells (AECII).
  
  
  METHODS
  Flow cytometry was used to analyze the phenotypes of AF-MSCs from 10 pregnant Sprague-Dawley rats. And the Oct-4 mRNA expression level was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Rat embryonic stem cell was used as a positive control. According to different culturing methods, AF-MSCs were randomly divided into 5 groups of A (control group), B, C, D and E. After in vitro differentiation, SPA, SPB, SPC, SPD and TTF1 mRNA expressions were detected by qRT-PCR, SPA and SPC protein expressions measured by immunofluorescence and lamellar bodies observed by transmission electron microscopy.
  
  
  RESULTS
  AF-MSCs could grow spirally in L-DMEM medium containing 20% fetal bovine serum and 4 µg/L basic fibroblast growth factor. The expressions of such surface antigens of AF-MSCs (third passage) as CD29 (99.1 ± 7.9)%, CD44 (99.2 ± 7.4)%, CD73 (75.6 ± 5.2)%, CD90 (98.9 ± 8.1)%, CD105 (92.9 ± 7.3)% and CD166 (89.3 ± 6.7)% were positive while CD34 and CD45 were negative. And the expression of Oct-4 mRNA (relative quantity: 0.690 ± 0.059) was significantly lower than rat embryonic stem cells (relative quantity: 1.000 ± 0.002) positive control group (P < 0.01). After in vitro differentiation, the expressions of SPA, SPB, SPC, SPD and TTF1 mRNA and SPA and SPC protein were negative in group A and positive in group B. The expressions of SPA, SPB, SPC, SPD and TTF1 mRNA (relative quantity: 0.426 ± 0.043, 0.368 ± 0.028, 0.492 ± 0.058, 0.327 ± 0.024 and 0.183 ± 0.018) and SPA and SPC protein in group B were significantly higher than other groups (all P < 0.01). Lamellar bodies could be found in the differentiated cells of group B.
  
  
  CONCLUSIONS
  Rat AF-MSCs from amniotic fluid may differentiated into AECII like cells in vitro.
authors.affiliation: Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou 310053, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Gu
authors.forename: Jianping
authors.initials: J
authors.lastname: Yan
authors.forename: Wulin
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Respiratory Medicine, Zhejiang Provincial People's Hospital, Hangzhou 310014, China. Email: lidoctor03@126.com.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Li
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Xia
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
mesh_terms: D000653:Amniotic Fluid; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology*; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction