The Functions Of MMP-2 And TIMP-1 In Experimental Rat Hepatic Fibrosis

Aims To investigate MMP-2 and TIMP-1 expression in hepatic fibrosis and the antifibrogenic role of exogenous IL-10. Methods The liver of Adult male Sprague-Dawley rat was perfused through portal vein with pronase E and type IV collagenase.Cells suspension was centrifuged by 11% Nycodenz density gradient centrifugation to isolate HSC. The viability of HSC was determined by trypan blue exclusion staining. The purity of HSC was identified by the expression of desmin using immunocytochemistry S-P method. Hepatic fibrosis was induced by CCL4 administration and 60 rats were randomly allocated into a normal control group(N group,8 rats), a CCl4 group(C group,28 rats) and a IL-10 group(I group,24 rats). At the beginning of the 7th and 11th week, rats in each group were routinely perfused and centrifuged to isolate HSC.RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in cultured HSC. Results The reliable and available method of isolation for HSC was successfully established for further research. The yield of the HSC was 1.2~2.3×106/g liver tissue, with viability over 90% and purity above 90%.Compared to N group at the 7th week, MMP-2 and TIMP-1 mRNA increased in both C group and I group (p<0.01);but I group was lower than C group(p<0.01). At the 11th week, MMP-2 mRNA in I group was still lower than C group(p<0.01), and both dropped in contrast to the 7th week(p<0.01);TIMP-1 mRNA in I group was still lower than C group(p<0.01), C group increased(p<0.01) but I group dropped (p<0.05)in contrast to the 7th week.Same results were found by immunocytochemistry. Conclusions MMP-2 expression increased in the early stage of hepatic fibrosis but decreased later on.TIMP-1 expression increased in hepatic fibrosis. IL-10 exhibit an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.