吡格列酮通过抑制PKA表达抑制AD大鼠脑片模型海马神经元HVA钙通道电流  

Pioglitazone inhibits HVA calcium channel currents via PKA in hippocampal neurons in rat brain slice model of AD

作　　者：权乾坤[1] 李玺[1] 袁海峰[2] 王娟[3] 王宁宁[1] 李明[1] 

机构地区：[1]西安交通大学第二附属医院老年病科,陕西西安710004 [2]西安交通大学第二附属医院脑病科,陕西西安710004 [3]解放军第四军医大学西京医院检验中心,陕西西安710032

出　　处：《西部医学》2016年第6期778-782,共5页Medical Journal of West China

基　　金：陕西省科技攻关计划项目[2007K16-07(5)];西安交通大学第二附属医院院重点基金项目[YJ(ZD)201517]

摘　　要：目的探讨PPARγ激动剂吡格列酮（pioglitazone,Pio）是否对Aβ致阿尔茨海默病（AD）大鼠脑片模型海马神经元高电压激活（high-voltage-activated,HVA）钙通道电流有抑制作用以及是否通过抑制蛋白激酶A（protein kinase A,PKA）表达途径而实现。方法采用Aβ（25-35）孵育大鼠脑片制备AD模型;采用全细胞膜片钳技术观察Pio干预后AD大鼠脑片模型海马神经元HVA钙通道在刺激电压下电流密度、Ⅰ-Ⅴ曲线、激活曲线及失活曲线的变化情况;采用免疫组织化学染色观察Pio干预后AD大鼠脑片模型PKA蛋白表达情况。结果 Aβ孵育可以导致大鼠脑片海马神经元HVA钙通道电流增加,激活曲线半激活电压减低,斜率因子增大;失活曲线半失活电压增大,斜率因子减小。Pio干预后AD大鼠脑片模型海马神经元HVA钙通道在各激活电压下电流密度降低;激活曲线半激活电压增加,斜率因子减小,HVA钙通道激活对电压的敏感性降低,不易被激活;失活曲线半失活电压减小,斜率因子增大,HVA钙通道失活对电压的敏感性增加,更易失活;同时海马神经元PKA蛋白表达水平下降。结论 Pio可能通过抑制PKA表达途径抑制AD大鼠脑片海马神经元HVA钙通道电流,从而减少细胞钙离子内流,降低细胞内钙离子水平,对抗Aβ的神经毒性。Objective To examine whether PPARγ agonist pioglitazone inhibits the high-voltage-activated calcium currents（ICa,HVA）via protein kinase A（PKA）in hippocampal neurons in rat brain slice model of AD.Methods An experimental Alzheimer disease（AD）model was prepared by exposure of rat brain slices to Aβ 25-35.After treatment with pioglitazone,the ICa,HVA elicited in hippocampal neurons in these rat brain slices was recorded by whole-cell patch clamp to analyze the changes in the peak current density,Ⅰ - Ⅴ curve,activation-V curve,and inactivation-V curve.The expression of PKA protein in these slices was detected by immunohistochemistry staining.Results Exposure of rat brain slices to Aβ led to increase in ICa,HVA,enhance the voltage sensitivity of channel activation,reduce the voltage sensitivity of channel inactivation and increase PKA protein level in hippocampal neurons in rat brain slice model of AD.Pioglitazone treatment significantly inhibited these changes.Conclusion Pioglitazone can inhibit HVA calcium channel currents via PKA in hippocampal neurons in rat brain slice model of AD.

关 键 词：阿尔茨海默病(AD) PPARΓ激动剂 高电压激活钙通道电流 蛋白激酶A 

分 类 号：R-33[医药卫生]