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

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(P0.05),相应海马组织中线粒体ΔΨm的水平升高(P0.05)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。

Role of PI3K/Akt signaling in the hippocampal cells from epileptic rats and intervention effect of grape seed procyanidins on it

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.