激活α7烟碱型乙酰胆碱受体减轻大脑皮质神经元氧糖剥夺损伤

Activation of α7 nicotinic acetylcholine receptor alleviates cerebral cortical neuron injury induced by oxygen-glucose deprivation

目的研究激活α7烟碱型乙酰胆碱受体(α7 nicotinic acetylcholine receptor,α7n AchR)对大脑皮质神经元氧糖剥夺损伤的作用及可能机制。方法取体外培养7 d的原代大脑皮质神经元,随机分为3组:对照组、氧糖剥夺组、PNU-282987(α7n AchR激动剂)组。氧糖剥夺组细胞氧糖剥夺12 h;PNU-282987组用PNU-282987预处理细胞24 h,然后氧糖剥夺12 h。采用CCK-8测定3组大脑皮质神经元存活率,比色法检测上清液乳酸脱氢酶(lactate dehydrogenate,LDH)含量,流式细胞术检测细胞凋亡率和活性氧(reactive oxygen species,ROS)产量,蛋白质印迹法检测血红素氧化酶(hemeoxygenase-1,HO-1)、缺氧诱导因子1α(hypoxia inducible factor-1α,HIF-1α)表达量。结果与氧糖剥夺组相比,PNU-282987可提高大脑皮质神经元存活率(P<0.05),降低LDH含量(P<0.05),抑制细胞凋亡(P<0.05),降低ROS产量(P<0.05),同时使HO-1蛋白表达升高、HIF-1α蛋白表达减少(P<0.05)。结论激活α7n AchR具有抗大脑皮质神经元氧糖剥夺损伤作用,该作用可能与抗氧化应激有关。

Objective To investigate the effect of activating α7 nicotinic acetylcholine receptor （α7nAchR） on cerebral cortical neurons injury induced by oxygen-glucose deprivation （OGD） and the possible mechanism. Methods Cerebral cortical neurons cultured for 7 d were randomly divided into three groups： control group, OGD group （Cells experienced a 12 h oxygen- glucose deprivation） and OGD group treated with PNU-282987 （Cells experienced a 12 h oxygen-glucose deprivation with PNU- 282987 pretreatment for 24 h）. Cell viability was determined by CCK-8 assay, lactate dehydrogenase （LDH） was examined to reflect cell injury, apoptosis and reactive oxygen species （ROS） production were analyzed by flow cytometry, and expression of hemeoxygenase-1 （HO-1） and hypoxia inducible factor-lα （HIF-lα） were detected by Western blotting analysis. Resulls OOD resulted in cell death, LDH increase, and cell apoptosis. Compared with the OGD group, PNU-282987 pretreated group had significantly increased cell survival （P〈0. 05）, significantly decreased LDH level and ROS production （P〈0. 05）, and significantly inhibited cell apoptosis （P〈0. 05）. Meanwhile, HO-1 protein expression was significantly increased and HIF-la protein expression was significantly reduced in PNU-282987 pretreated group compared with the OGD group （P〈0. 05）. Conclusion Activation of α7nAchR can protect cerebral cortical neurons against OGD-induced injury, which may be related to the anti-oxidative stress.