Synapsin1磷酸化参与开心散改善Aβ诱发的小鼠记忆障碍

Synapsin1 Phosphorylation Involved in Kaixin-San Improving Memory Dysfunction Induced by Aβ in Mice

目的观察开心散(Kaixin-San,KXS)对β淀粉样蛋白(amyloidβ,Aβ)所致小鼠记忆障碍的影响并探索其突触前膜机制。方法将小鼠随即分为3组,对照组、模型组(Aβ组)及开心散组(Aβ/KXS组)。Aβ组和Aβ/KXS组小鼠侧脑室注入5μL的Aβ1-42(1μM),对照组注射等体积生理盐水。Aβ/KXS组于实验开始前7天连续灌胃开心散(0.15 g·kg^-1)。采用Morris水迷宫和新奇事物认知方法评价各组小鼠学习记忆能力,电生理学测定高频刺激后第一分钟的PS振幅,蛋白质免疫印迹(Western-blot)法检测各组小鼠海马突触前膜突触蛋白1(Synapsin1,SYN1)及磷酸化突触蛋白1(phospho-SYN1,p-SYN1)的蛋白表达水平。结果 Morris水迷宫结果表明,与对照组比较,Aβ组小鼠逃避潜伏期明显延长(P <0.05),穿越平台次数明显减少(P <0.05);与Aβ组比较,Aβ/KXS组小鼠逃避潜伏期明显缩短(P <0.05),穿越平台次数明显增加(P <0.05)。新奇事物认知,与对照组比较,Aβ组小鼠对C物体的探索偏好指数b明显降低(P <0.05);与Aβ组比较,Aβ/KXS组小鼠探索偏好指数b明显增加(P <0.05)。电生理学测定,与对照组相比,Aβ组小鼠PS振幅降低(P <0.05);与Aβ组相比,Aβ/KXS组小鼠PS振幅明显增加(P <0.05)。且Aβ/KXS组小鼠海马区p-SYN1/SYN1灰度比值明显增加(P <0.05)。结论开心散增加突触前膜Synapsin1磷酸化可能是开心散改善Aβ诱发小鼠记忆障碍的机制之一。

Objective To observe the effect of Kaixin-San(KXS) on memory impairment induced by Aβ in mice and explore its presynaptic membrane mechanism.Methods ICR mice were then divided into three groups: model group(Aβgroup) and Kaixin-San group(Aβ/KXS group). The mice were injected with 5 μL of Aβ1-42(1 μM) into lateral ventricles, while the control group was injected with saline of equal volume. In Aβ/KXS group, KXS(0.15 g·kg^-1) was continuously administered 7 days before the the experiment. Morris water maze and novelty cognitive method were used to evaluate the learning and memory abilities of mice in each group. The PS amplitude in the first minute after high frequency stimulation was measured by electrophysiology. Western-blot was used to detect the expression of presynaptic synapsin 1(SYN1) and phosphorylated synapsin 1(p-SYN1) in the electrophysiological experiment. Results Compared with the control group, the escape latency of mice in group Aβ was significantly prolonged(P < 0.05), and the number of times crossing the platform was significantly reduced(P < 0.05). Compared with Aβ group, the escape latency of mice in group Aβ/KXS was significantly shortened(P < 0.05), and the number of times crossing the platform was significantly increased(P < 0.05) in Morris water maze test. Compared with the control group, the exploratory preference index b of mice in group Aβ was significantly lower(P < 0.05);compared with group Aβ, the exploratory preference index b of mice in group Aβ/KXS was significantly higher(P < 0.05) in novelty cognitive method. Compared with the control group, the PS amplitude of mice in group Aβ was decreased(P < 0.05), and the PS amplitude of mice in group Aβ/KXS was increased significantly(P < 0.05). The gray scale ratio of p-SYN1/SYN1 in hippocampus of mice in Aβ/KXS group increased significantly(P < 0.05). Conclusion The increase of p-SYN1 expression in presynaptic membrane by KXS may be one of the mechanisms of KXS in improving memory dysfunction induced by Aβ in mice.