The Impact Of Targeted COX-2shRNA On Liver Fibrosis In Experimental Rats

ObjectiveTo investigate the protective and therapeutic effects of COX-2shRNA on hepatic fibrosis and its anti-fibrosis mechanisms in rats induced by CCL4composite factor.Methods(1) The establishment of liver fibrosis model in rats:randomly divided50clean level SD rats into5groups equally after fed1week normally:normal group, model group, COX-2shRNA treatment group, empty carrier group, and nimesulide group. In addition to the normal group, CC14solution (40%CC14peanut oil,2ml/kg·time·5d) was instilled into stomach, and fed with high fat diet (added2%cholesterol,10%lard on the basis of normal feed) at the same time. One week after the establishment of model, COX-2shRNA treatment group was tail intravenous100ul COX-2RNAi, empty carrier group was tail intravenous100ul empty carrier, the other three groups are equal tail intravenous hysiological saline,1time/d; And at the same time, to the nimesulide group,6mg/kg nimesulide was instilled into stomach; as to the other group, equally0.5%carboxy methyl cellulose sodium solution was instilled into stomach,1time/d; the normal group fed with ordinary feed.(2) The observation of testing index in the rats:Observing the rats general situation, weighing after12weeks in intervention, taking blood and liver tissue after putting rats to death, and observing the gross appearance of the liver. Calculating liver index (the wet weight of liver/weight x100%), and testing the serum ALT of rats, aspertate aminotransferase(AST), total cholesterol (TC) and the level of triglycerides (TG). The liver tissue for Sudan IV dyeing, HE dyeing and Masson collagen dyeing to observe the pathology change of liver tissue in rats. Using the RT-PCR method to detect the expression of the COX-2, alpha SMA, the CCL2, P53,CXCL10mRNA in rat livers. Results(1) The impact of COX-2shRNA on rat liver weight and index:the weight of the rats increased at the end of made mode. Compared with normal group, the weight of the model group and empty carrier rats grow slowiy, but the liver index of the model group, empty carrier group and nimesulide group increase significantly, which have significant difference (P<0.01). The rats weight growth of the COX-2shRNA treatment group and nimesulide group more quickly than model group and empty carrier group, the liver index is lower than model group and empty carrier group. Especially the COX-2shRNA treatment group has better effect(P<0.01,0.05). The weight and liver index are no statistically significant (P>0.05) between empty carrier group and model group.(2) The impact of COX-2shRNA on rats serology index:compared with normal group, the level of ALT, AST, TC, TG that lied in rats serum of model group, COX-2shRNA treatment group, empty carrier group, and nimesulide group equally rises significantly(P<0.01);there are no otherness in the level of TG between nimesulide group and empty carrier group, in addition to it, the rest index of nimesulide group and the all index of COX-2shRNA treatment group were lower than that of model group and empty carrier group. And COX-2shRNA treatment group descends significantly most(P<0.01, P<0.05); there are no statistics significant on serology index of model group and empty carrier group (P>0.05).(3) The impact of COX-2shRNA on rat pathology:according to the show of Sudan Ⅳ dyeing, HE dyeing, and Masson collagen dyeing, the pathology score and the collagen area analysis of model group, COX-2shRNA treatment group, empty carrier group, and the nimesulide group are obviously higher than normal group (P<0.01). COX-2shRNA treatment group and nimesulide group pathology score and the collagen area analysis are lower than model group and empty carrier group. Especially the COX-2shRNA treatment group has more obvious effect (P<0.01, P<0.05).There are no statistics significant on pathology score and the collagen area analysis of empty carrier group and model group (P＞0.05).(4) The impact of COX-2shRNA on expression of each gene mRNA in rats:the expression level of the COX-2, alpha SMA, the CCL2, P53, CXCL10mRNA in model group, COX-2shRNA treatment group, empty carrier group and nimesulide group of liver tissue in rats are obviously higher than normal group (P<0.01); the expression level of each gene mRNA in the COX-2shRNA treatment group and nimesulide group are lower than the model group and empty carrier group, andCOX-2shRNA treatment group descends significantly most (P<0.01). There are no statistics significant between model group and empty carrier group (P>0.05).Conclusion1. The therapeutic effect of COX-2shRNA on hepatic fibrosis in experimental rats is effective, as it can reduce blood fat, improve hepatic pathology and liver pathology change.2. The protection of COX-2shRNA for hepatic fibrosis may be related to inhibiting the expression of COX-2, a-SMA, P53, CCL2and CXCL10in the liver tissue.3. Compared to nimesulide, COX-2shRNA has more obvious effect on hepatic fibrosis protection.