Objective: To study the effect of tissue inhibitor of metalloproteinases (TIMP)-1 siRNA and TIMP-2 siRNA on the expression of smad2/3/4 protein in CCl4-induced liver fibrosis rat hepatic stellate cells (HSC). Methods: Rat's liver tissues with liver fibrosis after treatment with pre-built TIMP-1siRNA and TIMP-2 siRNA were used as the research subjects. Immunohistochemistry, Western blotting and real-time PCR were used to detect the protein and corresponding mRNA expression levels on smad2/3/4. TUNEL and α-smooth muscle actin (α-SMA) positive cells were quantified by double-labeled immunofluorescence. Analysis of variance (ANOVA) was used to compare the means between multiple groups, and the SNK test was used for the pairwise comparison of means. Results: The results of immunohistochemistry showed that the protein expressions of smad2, smad3, and smad4 in the TIMP-1 siRNA group and TIMP-2 siRNA group were significantly reduced than those of the model and the negative control group (P < 0.05). In addition, Western blotting results had also shown the same trend. The protein expression of smad2, smad3, and smad4 in the TIMP-1siRNA group and TIMP-2siRNA group were significantly reduced than those of the model and the negative control group (P < 0.01). The mRNA expression of smad2, smad3, and smad4 in TIMP-1siRNA group and TIMP-2siRNA group was significantly reduced than those of the model and negative control group (P < 0.05). Immunofluorescence showed that the apoptosis of activated HSC in the TIMP-1 siRNA group(0.014 3 ± 0.002 4) and TIMP-2 siRNA group(0.010 7 ± 0.004 4) was increased than those of the model(0) and the negative control group (0.002 4 ± 0.002 4, P < 0.05). Conclusion: TIMP-1 siRNA and TIMP-2 siRNA promote the apoptosis of activated HSCs. In addition, it also has a significant inhibitory effect on the expression of smad protein.
目的： 研究基质金属蛋白酶组织抑制因子（TIMP）-1 siRNA、TIMP-2 siRNA对CCl(4)诱导的肝纤维化大鼠肝星状细胞(HSC)中smad 2/3/4蛋白表达的影响。 方法： 采用前期构建的TIMP-1 siRNA、TIMP-2 siRNA治疗后肝纤维化大鼠的肝脏组织作为研究对象，用免疫组织化学、蛋白质印迹法（Western blot）及Real-time PCR法检测smad2、smad3、smad4的蛋白表达和相应的mRNA表达水平，并用正置荧光显微镜计数免疫荧光双标记TUNEL阳性细胞和α-平滑肌肌动蛋白（α-SMA）阳性细胞。多组间均数比较采用ANOVA方差分析，均数两两比较采用SNK检验。 结果： 免疫组织化学结果显示TIMP-1 siRNA组、TIMP-2 siRNA组中smad2、smad3、smad4的蛋白表达量较模型组、阴性对照组明显减少（P值均< 0.05）。Western blot结果也显示相同趋势，TIMP-1siRNA组、TIMP-2siRNA组中smad2、smad3、smad4的蛋白表达量较模型组、阴性对照组显著减少（P值均< 0.01）。TIMP-1siRNA组、TIMP-2siRNA组smad2、smad3、smad4的mRNA表达量较模型组、阴性对照组明显减少（P值均< 0.05）。免疫荧光显示TIMP-1 siRNA组（0.014 3±0.002 4）、TIMP-2 siRNA组（0.010 7±0.004 4）活化HSC的凋亡指数较模型组(0)、阴性对照组（0.002 4±0.002 4）增加（P值均< 0.05）。 结论： TIMP-1 siRNA、TIMP-2 siRNA促进了活化HSC的凋亡，对smads蛋白的表达量有明显抑制作用。.
Keywords: Apoptosis; Hepatic stellate cell; Liver fibrosis; Ttissue inhibitor of metalloproteinases.