OBJECTIVETo observe epithelial-mesenchymal phenotypes and oxidative stress related protein expressions of the liver cells in a rat model of liver fibrosis induced by bile duct ligation and recanalization.

METHODSTwenty-four male Wistar rats were randomized into 4 groups, including a sham-operated group, two bile duct ligation groups with ligation for 2 and 4 weeks, and a bile duct ligation group with a 2-week ligation followed by a 2-week recanalization. HE staining and Masson staining were used to assess liver fibrosis in the rats, and immunohistochemistry and Western blotting were employed to detect expressions of the epithelial and mesenchymal marker proteins and oxidative stress-related proteins.

RESULTSCompared with the sham-operated group, the rats with bile duct ligation showed obvious liver fibrosis, which worsened as the ligation time extended, accompanied by significantly increased expression of α-SMA, collagen I, NOX(4) and vimetin and reduced E-cadherin expression. Compared with the rats with bile duct ligation for 4 weeks, the rats in bile duct ligation-recanalization group showed obviously lessened liver fibrosis, significantly lowered expressions of NOX(4) and mesenchymal cell maker proteins, and enhanced expressions of epithelial cell marker proteins.

CONCLUSIONBile duct ligation up-regulates mesenchymal phenotype-related proteins and NOX(4) protein expression and down-regulates the expression of epithelial phenotype-related proteins, and these changes can be reversed by subsequent bile duct recanalization.