Abstract
OBJECTIVE: To study the uptake of E. coli lipopolysaccharide (LPS) and expression of tumor necrosis factor-alpha-mRNA in isolated intrahepatic bile duct epithelial cells. METHODS: Fluorescent immunohistochemical and in situ hybridization techniques and observations with a confocal laser scanning microscope. RESULTS: Positive reactions to LPS were found in the cytoplasm of isolated intrahepatic bile duct epithelial cells after incubation with S type LPS (S-LPS) for 15 minutes, and the FITC fluorescent intensity against LPS was significantly higher than that of controls. After incubation with S-LPS for 3 hours, FITC fluorescent intensities to the expression of tumor necrosis factor (TNF)-alpha-mRNA by flurescent in situ hybridization in the cytoplasm and nuclei of cultured bile duct epithelial cells were significantly higher than that of controls. The increase of FITC fluorescent intensity to TNF-alpha-mRNA expression showed a peak at 6 hours after incubation and at various time points after incubation with LPS, the increase of fluorescent intensities in the cytoplasm were much higher than that in the nuclei. CONCLUSION: It is suggested that LPS could act on and enter into isolated intrahepatic bile duct epithelial cells and stimulate the expression of TNF-alpha-mRNA.