组织因子、Egr-1及Sp1在大鼠狭窄颈动脉内皮细胞的表达

目的研究在体动物颈动脉狭窄处内皮细胞组织因子基因的切应力性表达规律及其机制。方法实验分为对照组和颈动脉狭窄组,套扎法建立左颈总动脉狭窄模型,狭窄组又分为0.5 h1、h3、h6、h、12 h1、d、3 d和7 d8个时间点,术后不同时间点用原位杂交和免疫组织化学法,检测组织因子、Egr-1和Sp1的mRNA和蛋白表达,用图像分析系统测定内膜平均灰度,进行统计学分析。结果对照组内皮细胞组织因子、Egr-1及Sp1的mRNA转录和蛋白合成弱;狭窄30 min后,与对照组比较内皮细胞胞质组织因子基因mRNA转录和蛋白合成升高(P<0.05),内皮细胞胞核和胞质Egr-1和Sp1基因mRNA转录和蛋白合成均增加(P<0.05),但以Egr-1增加更显著(P<0.05),其变化趋势与组织因子基因mRNA转录及蛋白合成的变化趋势相同。组织因子基因mRNA转录和蛋白合成于6 h达到峰值,Egr-1基因mRNA转录和蛋白合成于3 h达到峰值,Sp1基因mRNA转录和蛋白合成于1 h达到峰值,与对照组比较差异有显著性(P<0.05)。结论颈动脉狭窄时,切应力能够诱导动脉狭窄处内皮细胞组织因子基因表达,其表达与内皮细胞转录因子Egr-1和Sp1介导有关。

Expression of Tissue Factor and Stimulatory Protein and Early Growth Response-1 in Endothelial Cell of Arteria Carotis Stenosis in Rats

Aim To investigate the expression of tissue factor(TF) and its mechanism in endothelial cell induced by fluid shear stress in vivo. Methods Fifty-four male SD rats(weight 300±16 g) were randomly divided into nine groups(n=6,respectively). The time course of mRNA and protein expression of TF,nuclear factor stimulatory protein(Sp1) and early growth response-1(Egr-1) were examined on the model of loop ligature method of stenosis the left arteries carotis communis intima in the rat with the combination of in situ hybridization and immunohistochemistry methods,performed computer image analysis were used. Results The mRNA and potein of TF and Egr-1 and Sp1 were faintly expressed in intima of control group,after exposed to stenosis,the staining intensity was increased 30 minutes after wall shear stress.The mRNA and protein expresion of TF markedly increased compared with control group(p<0.05).The mRNA and protein expresion of Egr-1 and Sp1 increased(p<0.05).The change of Egr-1 was more significant than that of Sp1(p<0.05).The change trend of Egr-1 and Sp1 expresion were similar to that of TF.The mRNA and potein of TF peaked at 6 hour,the mRNA and potein of Egr-1 peaked at 3 hour,the mRNA and potein of Sp1 peaked at 1 hour,with significant differences from control group(p<0.05). Conclusion In carotid artery stenosis, the shear stress can up-regulate TF expression in the endothelium,and its mechanism is related to the activation of Sp1 and Egr-1.