Correlation between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models

AIM: To evaluate serum TIMP-1 level and the correlation between TIMP-1 expression and liver fibrosis in immune-induced and CCL₄-induced liver fibrosis models in rats.

METHODS: Immune-induced and CCL₄-induced liver fibrosis models were established by dexamethasone (0.01 mg) and CCL₄ respectively. Serum TIMP-1 level was detected with ELISA, while histopathological grade of liver biopsy was evaluated. Spearman rank-correlation test was used to analyse the difference of the correlation between the TIMP-1 expression and hepatic fibrosis in the two fibrosis models. Furthermore, in situ hybridization was used to determine the expression difference of TIMP-1 mRNA in the two models.

RESULTS: Positive correlation existed between serum TIMP-1 level of immune induced group and the histopathological stages of fibrosis liver of corresponding rats (Spearman rank-correlation test, r_s = 0.812, P ＜ 0.05), and the positive in situ hybridization signal of TIMP-1 mRNA was strong. In CCL₄-induced liver fibrosis model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant(Spearman rank-correlation test, r_s = 0.229, P ＞ 0.05). And compared with immune-induced model, the positive in situ hybridization signal of TIMP-1 mRNA was weaker, while the expression variation was higher in hepatic fibrosis of the same severity.

CONCLUSION: The correlations between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models are different. In immune-induced model, serum TIMP-1 level could reflect the severity of liver fibrosis, while in CCL₄-induced model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant.