早期生长反应因子-1的特异脱氧核酶对球囊损伤大鼠颈动脉后转化生长因子-β_1表达的影响

EFFECTS OF DNA ENZYME TARGETING Egr-1 ON THE EXPRESSION OF TGF-β_1 AFTER BALLOON INJURY OF RAT COMMOM CAROTID ARTERY

目的观察局部转染早期生长反应因子-1(Egr-1)的特异脱氧核酶(ED5)对球囊损伤颈总动脉后内膜增生及转化生长因子-β1(TGF-β1)表达的影响,并初步探讨ED5抑制球囊损伤后内膜增生的机制。方法96只健康雄性Wistar大鼠,随机分为4组,每组24只。除假手术组外均应用2F球囊导管行颈总动脉内膜球囊损伤术,术中采用转染试剂FuGENE6介导ED5转染至损伤后大鼠血管中,以假手术组、单纯损伤组,FuGENE6组作为对照。术后3、7、14、21d处死动物每组6只。应用HE染色,RT-PCR,Western-blot和免疫组织化学方法观察大鼠颈动脉球囊损伤后内膜增生情况和TGF-β1的表达及ED5对它们的影响。结果(1)内皮损伤后3d内膜增厚不明显,7d内膜开始增厚,14、21d时内膜明显增厚。(2)TGF-β1mRNA于术后3d开始升高,7d达高峰,14d时下降。TGF-β1蛋白表达于术后3d开始升高,14d达高峰。(3)转染ED5治疗后,在各个时间点内膜增厚程度减轻,TGF-β1表达减少,与对照组比较差异有显著性(P<0·01)。结论血管内皮损伤后内膜增生过程中TGF-β1表达增加,ED5能抑制TGF-β1的表达,从而减轻血管损伤后内膜的增生。

Objective To observe the effects of the local transfection of DNA enzyme targeting Egr- 1 （early growth response factor-1） （ED5） on neointimal formation and TGF-β1 expression after artery balloon injury, and to explore its possible mechanism of inhibiting neointimal formation. Methods Ninetysix male Wistar rats were randomly divided into four groups. Endothelial denudation of rats was performed with 2F balloon catheter except rats in the sham group. ED5 was transfected into the artery wall of the ED5 group by FuGENE6 during operation. The sham group, the simple injury group the and FuGENE6 group served as control groups. Six rats of each group were killed on the 3rd, 7th, 14th, 21th day after balloon injury. The intimal thickness and the expression of TGF-β1 were detected by HEstaining, RT-PCR, Western-blot and immunhistochemical methods. Results （1） The thickening of intima began on the day after ingury, and became more significant on the 14th and 21th day. （2） The level of TGF-β1 mRNA began to increase on the 3th day and peaked on the 7th day. The expression of TGF-β1 protein began to increase on the 3th day and peaked on the 14th day. （3） The levels of TGF-β1 mRNA and protein were reduced and the intimal hyperplasia was inhibited after treatment with ED5, and there were significant differences between the ED5 group and the control groups （P〈0.01）. Conclusion The level of TGF-β1 mRNA and the expression of TGF-β1 protein are increased in the process of intimal thickening. ED5 can decrease the expression of TGF-β1 and inhibite neointimal hyperplasia after balloon injury.