大鼠脑缺血预处理的神经保护作用与调节核因子-KB和Hes1表达有关

Neuroproteclive effect of cerebral ischemic preconditioning is associated with regulation of expressions of nuclear factor-roB and Hesl in rots

目的通过钡0定大鼠脑缺血再灌注后海马核因子-KB（nuclear factor-KB，NF-KB）和HeslmRNA表达的变化来探讨脑缺血预处理的神经保护机制。方法健康雄性SD大鼠108只，随机分为脑缺血组、脑缺血预处理组和假手术组，再分为22h、48h、72h、7d、14d亚组。脑缺血预处理组大鼠在建立脑缺血再灌注损伤模型前3d通过右侧颈内动脉短暂性血流阻断10min实施缺血预处理。在脑缺血再灌注后各时问点进行神经功能评分、脑梗死体积测定并通过实时荧光定量聚合酶链反应测定海马NF-kB和HeslmRNA表达。结果脑缺血预处理组各时间点神经功能缺损评分和脑梗死体积百分比均显著低于脑缺血再灌注组（P均〈0．05）。各组NF-KB和HeslmRNA表达水平均随时间推移出现进行性降低，对同一时间点进行的比较显示，脑缺血预处理组和脑缺血再灌注组NF-KB和HeslmRNA表达水平均显著高于假手术组，但脑缺血预处理组NF-KBmRNA表达水平显著低于脑缺血再灌注组，而HeslmRNA表达水平显著高于脑缺血再灌注组（P均〈0．05）结论Hesl的上调和NF-KB的下调可能与脑缺血预处理的神经保护机制有关。

Objective To investigate the neuroprotective mechanism of cerebral ischemic preconditioning by detecting the expression changes of hippocampus nuclear factor-KB （NF-KB） and Hesl mRNA after cerebral ischemia-reperfusion in rats. Methods A total of 108 healthy male SD rats were randomly divided into a cerebral ischemia group, a cerebral ischemic preconditioning group, and a sham operation group, and then redivided into 22 h, 48 h, 72 h, 7 d, and 14 d subgroups. Ischemic preconditioning was performed at day 3 before establishing the cerebral ischemia-reperfusion injury model by transient occlusion of right internal carotid artery for 10 min. At each time point after cerebral ischemia-reperfusion, the neurological deficit score and cerebral infarction volume measurement were performed, and the expressions of NF-KB and Hesl mRNA in the hippocampus were detected by using real-time fluorescence quantitative potymerase chain reaction. Results The neurological function scores and the percentage of cerebral infarction volume in the cerebral ischemic preconditioning goup at each time point were significantly lower than those in the cerebral ischemia-reperfusion group （all P 〈0. 05）. The expression levels of NF-KB and Hesl mRNAs in each group had progressive reduction with time. Compared with the same time point, it showed that the expression levels of NF-KB and Hesl mRNAs in the cerebral ischemic preconditioning group and the cerebral ischemia-reperfusion group were significantly higher than those in the sham operation group, the expression level of NF-KB mRNA in the cerebral ischemic preconditioning group was significantly lower than that in the cerebral ischemia-reperfusion group, and the expression level of Hesl mRNA was significantly higher than that in the cerebral ischemia-reperfusion group （all P 〈0. 05）. Conclusions The up-regulation of Hesl and down-regulation of NF-KB may be involved in the neuroprotective mechanisms of cerebral ischemic preconditioning.