Effect of tissue inhibitor of metalloproteinases 1 and 2 siRNA on the expression of Smad7 protein in hepatic fibrosis rats

Abstract:

Objective：To observe the expression of Smad7 protein in carbon tetrachloride（CCl4）-induced hepatic fibrosis rats treated with TIMP-1 short interference RNA（siRNA） and TIMP-2 siRNA. Methods：The hepatic tissues collected from hepatic fibrosis rats were divided into 5 groups：normal group，model group，negative control group，TIMP-1 siRNA 0.250 mg/kg group and TIMP-2 siRNA 0.250 mg/kg group. The expression of Smad7 was detected by real-time PCR，immunohistochemistry and Western blot. Results：Real-time PCR analysis showed that mRNA expression of Smad7 was significantly higher in TIMP-1 siRNA 0.250 mg/kg group（59.7±3.3）% and TIMP-2 siRNA 0.250 mg/kg group（60.2±3.4）% than in model group（28.0±1.6）% and negative control group（28.6±1.7）%（P=0.000）. Immunohistochemistry showed that protein expression of Smad7 was significantly higher in TIMP-1 siRNA 0.250 mg/kg group（8.55±0.67） and TIMP-2 siRNA 0.250 mg/kg group（8.23±0.85） than in model group（4.25±0.53） and negative control group（4.19±0.55）（P=0.000）. Western blot showed that protein expression of Smad7 was significantly higher in TIMP-1 siRNA 0.250 mg/kg group（0.706±0.039） and TIMP-2 siRNA 0.250 mg/kg group（0.698±0.038） than in the model group（0.278±0.013） and negative control group（0.285±0.014）（P=0.000）. Conclusion：Silencing the TIMP-1 and TIMP-2 with siRNA could be involved in the improvement of the hepatic fibrosis in rats.