Experimental Study On The Effect Of Gene Expression Regulation Of Matrix Metalloproteinases Adn Tissue Inhibitor Of Metalloproteinases In The Therapy Of Liver Fibrosis

Background: As the common pathological foundation and generative route of liver cirrhosis due to various pathogeny, liver fibrosis occurs as a result of the net-deposition of excess extracellular matrix (ECM). It results from synthesis and deposition overwhelming degradation of ECM(especially type I and III collagen). The family of enzymes involved in degradation of ECM in liver are matrix metalloproteinases(MMPs), they could be inhibited by tissue inhibitors of metalloproteinases(TIMPs). As the research results, Milv[P 1, MIVIP2 and TIMP 1 play important roles in the pathogenesis, development and reversal of liver fibrosis. As we known, interferon a (IFN a )and Tetrandrine(Tet) have good therapic effects on the liver fibrosis. They could inhibit ECM synthesis and stimulate its degradation in liver, but their therapic mechanism is not very clear, and the relationship between their therapic effects and the expression of MMPs and TIMPs in liver has not ever been reported. So we plan to investigate the relationship between IFN a ,Tet and the expression ofMMIP1,MMP2 and TIMP1. Objective: To investigate the dynamic alteration of MIvIP1,MMP2 and TIMP 1 gene and pro enzyme expression during l?FN a and Tet therapy course on experimental rat liver fibrosis respectively and illustrate their therapy mechanism further and the effect of gene expression regulation of MIvIPs and TLMPs in the therapy of liver fibrosis. Methods and Results: I .CCI4-induced liver fibrosis of rat model was used. At the early or intermediate stage of fibrosis (B week after first injection), we used WN a (for 6 weeks) and Tet(for 12 weeks) to treat the disease respectively. The result is that both IFN a and Tet could lessen the fibrosis degree and ALT level obviously, reverse the liver fibrosis. 2.Quantitative analysis of reverse transcription polymerasechain reaction for MMP I ,MIMIP2 and TIMP 1 mRNA expression level during the therapy of experimental liver fibrosis. The results were that IFN a could improve MMP 1 gene expression, inhibit MMP2 gene expression and has no effect on TIMP1 gene expression; Tet could inhibit TIMP1 gene expression and has no effect on MMP 1 and MMP2 expression. 3.Immunohistochemistry and Western blot assay for MMP1,MMP2 and TIM? 1 protein expression during the therapy course. Positive stain was present in normal and fibrous liver and focussed in the fibrous and Disse space in the development and reversal of liver fibrosis, these three proenzymes are located in the same place. Western blot quantitative analysis result of proenzyme was similar to the gene expression. Conclusion: Both IFN a and Tet have good curative effects on early liver fibrosis. IFN a could improve MMP 1 synthesis by increasing its gene expression, resulting in type I and III collagen degradation. At the same time, the IV collagen basis membrane degradation decreases resulting from IFN a inhibition of MMP2 gene expression, so the deposition of interstitial collagen under endothelial tissue reduces, the fibrosis reverses. Tet could inhibit TIM 1 gene expression, which could result in the relative increasing activity of MMP1, so that the liver fibrosis could reverse. It's a good therapeutic method for liver fibrosis by the regulation of MMPs and TIMPs gene expression to participate M degradation in liver.