title: Uptake of bacterial lipopolysaccharide and expression of tumor necrosis factor-α-mRNA in isolated rat intrahepatic bile duct epithelial cells.
abstract: OBJECTIVE
  To study the uptake of bacterial lipopolysaccharides (LPS) and expression of tumor necrosis factor α-mRNA (TNF-α-mRNA) with cultured rat intrahepatic bile duct epithelial cells.
  
  
  METHODS
  By using fluorescent, immunohistochemical and in situ hybridization techniques, the uptake of Escherichia coli LPS and expression of TNF-α-mRNA with isolated rat intrahepatic bile duct epithelial cells were observed with confocal laser scanning microscopy.
  
  
  RESULTS
  Positive reactions to LPS were found in the cytoplasm of isolated intrahepatic bile duct epithelial cells after incubation with LPS for 15 min and the FITC fluorescent intensity against LPS was significantly higher than that of the controls (121.45 μFI/μm(2) ± 15.62 μFI/μm(2) vs 32.12 μFI/μm(2) ± 9.64 μFI/μm(2), P < 0.01). After incubation with LPS for 3 h, fluorescein isocyanate (FITC) fluorescent intensities of the expression of TNF-α-mRNA with fluorescent in situ hybridization in the cytoplasm and nuclei of the cultured bile duct epithelial cells were significantly higher than those of the controls (189.15 μFI/μm(2) ± 21.33 μFI/μm(2) vs 10.00 μFI/μm(2) ± 8.99 μFI/μm(2), 64.85 μFI/μm(2) ± 14.99 μFI/μm(2) vs 21.20 μFI/μm(2) ± 2.04 μFI/μm(2), respectively (P < 0.01)). The increase of FITC fluorescent intensity of TNF-α-mRNA expression in the cytoplasm peaked at 6 h after incubation (221.38 μFI/μm(2) ± 22.99 μFI/μm(2)). At various time points after incubation with LPS, the increase of fluorescent intensities of TNF-α-mRNA in the cytoplasm were much higher than those in the nuclei (P < 0.01).
  
  
  CONCLUSIONS
  LPS can act on and enter into isolated intrahepatic bile duct epithelial cells and stimulate the expression of TNF-α-mRNA.
authors.affiliation: Xian-Ming Chen, De-Wu Han, Institute of Hepatology, Shanxi Medical University, Taiyuan 030001, Shanxi Province, China.
authors.forename: X M
authors.initials: XM
authors.lastname: Chen
authors.affiliation: Xian-Ming Chen, De-Wu Han, Institute of Hepatology, Shanxi Medical University, Taiyuan 030001, Shanxi Province, China.
authors.forename: D W
authors.initials: DW
authors.lastname: Han
authors.affiliation: Xian-Ming Chen, De-Wu Han, Institute of Hepatology, Shanxi Medical University, Taiyuan 030001, Shanxi Province, China.
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.affiliation: Xian-Ming Chen, De-Wu Han, Institute of Hepatology, Shanxi Medical University, Taiyuan 030001, Shanxi Province, China.
authors.forename: K
authors.initials: K
authors.lastname: Tanikawa
keywords: Epithelial cell bile ducts; In situ hybridization; Lipopolysaccharides; Tumor necrosis factor