大鼠局灶性脑缺血预处理后活化转录因子6 mRNA及其蛋白表达的变化

Activating transcription factor 6 mRNA and its protein expression in rats following cerebral focal ischemic preconditioning

目的观察脑缺血预处理对大鼠脑缺血再灌注后活化转录因子6(ATF6)mRNA及其蛋白表达的影响。方法选择SD大鼠120只,随机分为假手术组、缺血再灌注组、缺血预处理组,每组40只,每组又按照再缺血后12h,1、2、3d分为4个时间点,每个时间点10只。采用二次线栓法制备大鼠局灶性脑缺血预处理模型,实时荧光定量PCR和免疫组织化学法观察再缺血后各个时间点ATF6mRNA及其蛋白的表达变化。结果与假手术组比较,缺血再灌注组ATF6mRNA及其蛋白表达均于缺血再灌注后12h开始明显上升,1d达高峰,随再灌注时间延长其表达逐渐下降,但仍保持较高表达水平(P<0.05,P<0.01);缺血预处理组各时间点ATF6mRNA及其蛋白表达水平较缺血再灌注组明显升高(P<0.05)。结论脑缺血预处理可能通过诱导ATF6表达发挥其神经保护作用。

Objective To study the effect of cerebral ischemic preconditioning on activating transcription factor 6 （ATF6） mRNA and protein expression in rats following ischemia/reperfusion （I/R）.Methods One hundred and twenty SD rats were randomly divided into sham operation group,I/R group and ischemic preconditioning group （40 in each group）.Rats in each group were further divided into 12 h ischemic group,1 d ischemic group,2 d ischemic group and 3 d ischemic group （10 in each group）.A rat cerebral focal ischemic preconditioning model was established by double Longa occlusion.The ATF6 mRNA and protein expressions in 12 h ischemic group,1 d ischemic group,2 d ischemic group and 3 d ischemic group were detected by RT-PCR and immunohistochemistry,respectively.Results The ATF6 mRNA and protein expression levels were significantly higher in I/R group than in sham operation group at 12 h after I/R,and in I/R group than in ischemic preconditioning group at different time points,reached their peak on day 1 after I/R,and remained rather high although they decreased with the prolonged reperfusion time （P＜ 0.01,P＜0.05）.Conclusion Cerebral ischemic preconditioning can protect nerves by inducing the ATF6 expression.