PI3K/Akt 信号通路在癫痫鼠海马神经细胞中的作用及葡萄籽原花青素影响

摘要

Objective To investigate the role of PI3K/Akt signaling in rat hippocampal neuronal apoptosis induced by PTZ kindling, and the preventive effect of GSPE on the pathway. Methods Rats were randomly divided into 5 groups(10 rats/group): normal control group, epilepsy model group(PTZ group), LY294002(an inhibitor of PI3K/AKT pathway)+ PTZ group, GSPE + LY294002 + PTZ group, and GSPE + PTZ group. The flowcytometry analysis was utilized to detect the level of mitochondrial membrane potential(ΔΨm), and Western blot experiment was used to detect the levels of p-Akt and Caspase 3 in the hippocampus. In addition, the ultrastructure of mitochondria was observed by transmission electron microscopy to determine the effect of GSPE on that. Results Compared with the PTZ group, the level of Caspase 3 was increased significantly in the LY294002 + PTZ group. While compared with the LY294002 + PTZ group, the increased p-Akt and decreased Caspase 3 levels were observed in the GSPE + PTZ group. Meanwhile, the increased ΔΨm level(P<0.05)and improved mitochondria ultrastructures were also found in the GSPE + PTZ group. However, there was no significant difference in above mentioned between GSPE + LY294002+ PTZ group and LY294002 + PTZ group. Conclusion GSPE can alleviate neuronal apoptosis induced by seizures in hippocampus and protect the mitochondria function in the epiletpic rats. The mechanism may be related to the activation of PI3K/Akt pathway which inhibits the expression of Caspase 3 in the neuron.%目的：探讨 PI3K/Akt 信号通路在戊四氮（PTZ）诱导癫痫大鼠海马神经细胞凋亡中的作用及葡萄籽原花靑素（GSPE）对其影响。方法根据是否给予 PI3K/Akt 信号通路特异性抑制剂LY294002，将大鼠随机分为5组，每组10只：正常对照组、癫痫模型组（PTZ 组）、LY294002+PTZ 组、GSPE+LY294002+PTZ 组、GSPE+PTZ 组。采用流式细胞学检测海马组织线粒体膜电位（ΔΨm）水平， Western blot 法检测海马组织 p-Akt、Caspase 3蛋白的表达变化，电镜观察线粒体的超微结构，以明确GSPE 预处理对上述指标的影响。结果与 PTZ 组相比，LY294002+PTZ 组中 Caspase 3表达水平显著升高。与 LY294002+PTZ 组相比，GSPE+PTZ 组中 p-Akt 水平明显升高、Caspase 3蛋白水平明显下降（P<0.05），相应海马组织中线粒体ΔΨm 的水平升高（P<0.05）及超微结构有所改善；而 GSPE+LY294002+PTZ 组中上述指标则差异无统计学意义。结论 GSPE 干预可抑制癫痫鼠海马神经细胞的凋亡并保护线粒体的功能，其机制可能与激活 PI3K/Akt 信号通路抑制 Caspase 3的表达有关。