siRNA对肝纤维化的抑制作用

Inhibition of Liver Fibrosis by siRNA

目的:研究肝星状细胞(HSC)中smad2特异性小干扰RNA(siRNA)对Ⅰ型胶原表达的抑制作用,探讨抗肝纤维化的基因治疗新方法。方法:设计合成靶向Smad2基因的siRNA,将筛选成功的siRNA瞬时转染入体外培养的肝星状细胞(HSC),并给予转化生长因子β(TGF-β)刺激,应用RT-PCR和Western blot技术检测对照组与实验组Ⅰ型胶原mRNA水平和蛋白水平表达差异,研究siRNA对Ⅰ型胶原表达的抑制作用。结果:siRNA能明显降低肝星状细胞中Smad2的RNA和蛋白的表达水平,证实筛选的siRNA有效,能特异性抑制Smad2的基因表达;TGF-β刺激肝星状细胞后,与对照组比较,siRNA转染组细胞外基质(ECM)成分Ⅰ型胶原的表达水平明显降低(P<0.05)。结论:siRNA能够抑制TGFβ对肝星状细胞的激活,阻断TGFβ-Smads传导通路,使Ⅰ型胶原分泌下调,有效抑制TGFβ诱导的肝纤维化。

Objective： To investigate the inhibitory effect of collagen I expression by Smad2 targeted siRNA in hepatic stellate cell, and to explore the new methods of Liver fibrosis gene therapy. Methods： Four target sequences of Smad2 mRNA were chosen by aid of computer designing. The lipidosome vector which expressed Smad2-target- siRNA, was established. The effective siRNA was screened then transfected into the hepatic stellate cells （HSC） in vitro culture, and give the transformation growth factor beta （TGF-β） stimulation. The mRNA expression and protein synthesis in the HSC cell line were tested by RT-PCR and western blot technology. Results： Both mRNA and protein levels of samd2 were effectively down-regulated. The screening siRNA effective was confirmed, and the expression of smad2 gene could be inhibited specifically. Collagen I in the cell culture medium of HSC was reduced as well. （p〈0. 05）. Conclusions： Smad2 targeted siRNA could reduce the expression of Smad2 and collagen I in the HSC cell line and protecte HSC from the disadvantageous influences of TGF-β.