论文部分内容阅读
目的研究脑缺血预处理(CIP)对大鼠脑缺血再灌注(I/R)损伤的保护作用并观察CIP对核因子E2相关因子2(Nrf2)/醌氧化还原酶1(NQO-1)信号通路的影响。方法按照体重将雄性SD大鼠随机分成3组:假手术组、模型组、实验组。模型组建立短暂性右侧大脑中动脉闭塞(MCAO)动物模型;实验组进行CIP。分别于术后6,12,24,48,72 h这5个时间点,对大鼠进行神经功能评分,然后将动物断头处死。用2,3,5-氯化三苯基四氮唑法测定大鼠脑梗死体积;用免疫组化法观察脑组织切片中转录因子Nrf2核转移情况;以逆转录定量PCR(qRT-PCR)测定脑缺血后梗死侧皮质Nrf2、NQO-1基因的表达;用水溶性四唑盐(WST-1)法测定SOD表达和用硫代巴比妥酸(TBA)法测定MDA活性。结果 Nrf2阳性细胞在24 h达高峰,实验组与模型组的阳性细胞数分别为78.33±10.15,63.50±6.66,差异有统计学意义(P<0.05)。实验组与模型组于24 h的Nrf2分别为3.07±0.55,2.41±0.61;这2组的NQO-1 mRNA分别为3.78±0.52,2.73±0.76,差异有统计学意义(P<0.05,P<0.01)。在24 h,实验组与模型组的MDA表达分别为(25.43±8.68),(39.91±7.10)nmol·mg~(-1)prot,差异有统计学意义(P<0.05)。在24 h,实验组与模型组的SOD化酶活性活性分别为(269.83±42.41),(189.50±37.57)U·mg~(-1)prot,2组比较差异有统计学意义(P<0.05)。结论 CIP通过转录因子Nrf2/抗氧化反应元件信号通路,调节下游抗氧化应激产物的表达,保护脑缺血再灌注引起的脑组织损伤。
Objective To investigate the protective effect of cerebral ischemia preconditioning (CIP) on the injury of cerebral ischemia-reperfusion (I / R) in rats and to observe the effects of CIP on Nrf2 / quinone oxidoreductase 1 (NQO-1) ) Signaling pathways. Methods Male SD rats were randomly divided into 3 groups according to body weight: sham operation group, model group and experimental group. The model group was established transient right middle cerebral artery occlusion (MCAO) animal model; experimental group CIP. At 6, 12, 24, 48 and 72 h postoperatively, the rats were scored for neurological function, and the animals were sacrificed. The cerebral infarction volume was measured by 2,3,5,5-triphenyltetrazolium chloride method. The nuclear translocation of Nrf2 in brain tissue sections was observed by immunohistochemistry. The expression of Nrf2 was detected by reverse transcription-polymerase chain reaction (qRT-PCR) The expression of Nrf2 and NQO-1 genes in the infarct cortex was measured after cerebral ischemia. The SOD activity was measured by WST-1 method and MDA activity was measured by thiobarbituric acid (TBA) method. Results The Nrf2 positive cells peaked at 24 h. The number of positive cells in the experimental group and the model group was 78.33 ± 10.15 and 63.50 ± 6.66, respectively, with statistical significance (P <0.05). The Nrf2 of experimental group and model group at 24 h were 3.07 ± 0.55 and 2.41 ± 0.61, respectively. The NQO-1 mRNA of the two groups were 3.78 ± 0.52 and 2.73 ± 0.76, respectively, with significant difference (P <0.05, P < 0.01). At 24 h, the MDA expression in the experimental and model groups was (25.43 ± 8.68) and (39.91 ± 7.10) nmol · mg ~ (-1) prot, respectively, with significant difference (P <0.05). At 24 h, the activities of SOD in the experimental and model groups were (269.83 ± 42.41) and (189.50 ± 37.57) U · mg ~ (-1) prot, respectively, with significant difference between the two groups (P <0.05 ). Conclusion CIP can regulate the expression of anti-oxidative stress products and protect brain tissue from cerebral ischemia-reperfusion injury through the transcription factor Nrf2 / antioxidant signaling pathway.