摘要
目的探究血栓通[主要有效成分为三七皂苷(panax notoginseng,PNS)]对阿尔茨海默症(Alzheimer’s disease,AD)模型小鼠认知功能及神经兴奋性的影响,并探讨其潜在分子机制。方法用APP/PS1小鼠作为AD研究动物模型,在小鼠淀粉样蛋白尚未检测到阶段(2月龄)开始每日以60 mg/kg对血栓通组(APP/PS1+PNS)行灌胃给药,每日1次,连续给药6个月(给药至8月龄);对照组小鼠予同等体积的0.9%氯化钠(APP/PS1+vehicle)灌胃处理,同月龄野生型小鼠予0.9%氯化钠灌胃处理作为正常对照组(WT+vehicle),每组各15只。6个月后,新物体识别实验、Morris水迷宫实验检测小鼠的认知功能;EEG脑电检测、Western blot、细胞表面生物素化试验以检测各组小鼠皮质与海马中BACE1的活性、Nav1.1α的分布、表达以及Navβ2的表达与酶解情况(Navβ2的酶解片段Navβ2 full length及Navβ2-CTF表达检测)。结果新物体识别实验显示,与对照组APP/PS1小鼠相比,血栓通用药后APP/PS1小鼠的辨别指数(discrimination index,DI)上升(P<0.05);Morris水迷宫检测结果发现,血栓通灌胃6个月后小鼠在探索实验中逃避潜伏期缩短(P<0.05),撤除平台后在目标象限停留时间增加(P<0.05)、穿梭平台次数增加(P<0.05);EEG脑电检测结果发现,血栓通给药后减少了APP/PS1小鼠棘波放电出现的频率(P<0.05)。血栓通给药后显著降低了BACE1蛋白水平的表达(P<0.05),而全长片段Navβ2的蛋白水平显著上升(P<0.05),并纠正了Nav1.1α在神经元内外的异常分布(P<0.05)。结论血栓通可以改善AD模型小鼠的学习记忆能力、纠正大脑异常兴奋性,其作用机制可能与抑制BACE1的活性从而减少Navβ2由APP/PS1诱导的过度酶解,纠正皮质、海马神经元Nav1.1α的异常表达与分布,调节神经元的兴奋性有关。
Objective To explore the possible effects and the underlying molecular mechanisms of xueshuantong[The main active component is panax notoginseng(PNS)]on the cognitive function and neural excitability of mice with Alzheimer’s disease(AD).Methods The APP/PS1 mice were used as an animal model for AD research,at the stage when amyloid protein was not detected in mice(2 months of age).Mice in the xueshuantong group(APP/PS1+PNS)were administered by gavage once a day at a dose of 60 mg/kg for six months(for 8 months of age).The mice of the control group were given 0.9%sodium chloride(APP/PS1+Vehicle)intragastric treatment of the same volume,while the wild-type mice of the same age were given 0.9%sodium chloride intragastric treatment as the normal control group(WT+Vehicle)(15 mice in each group,n=15).After six months,the cognitive function of the mice was evaluated by the Novel Object Recognition(NOR)task and Morris Water Maze(MWM)test.The activity of BACE1,the distribution and expression of Nav1.1α,as well as the expression and enzymatic hydrolysis of Navβ2(Navβ2 full-length and Navβ2-CTF fragments)in cortex and hippocampus were detected by EEG,Western blot and cell surface biotinylation assay,respectively.Results The NOR task showed that compared with the mice in the APP/PS1+Vehicle group,the Discrimination index(DI)of mice in the APP/PS1 group was significantly increased after xueshuantong administration(P<0.05).The MWM test found that,the escape latency of the mice in the xueshuantong group was shortened followed six months in gastric administration(P<0.05),while the stay time in the target quadrant and the number of platforms significantly increased(P<0.05)after the removal of the platform.The results of EEG recording showed that xueshuantong reduced the frequency of spike-wave discharges in APP/PS1 mice(P<0.05).Furthermore,xueshuantong significantly reduced the expression of BACE1(P<0.05).In the APP+PNS group,the expression of Navβ2 full-length was increased(P<0.05),as well as corrected the abnormal distribution of Nav1.1αinside and outside of neurons(P<0.05).Conclusion Treatment with xueshuantong can significantly improve the learning and memory ability and correct the abnormal excitability of the brain in AD model mice.The mechanism may be related to the inhibition of BACE1 activity,the reduction of APP/PS1-induced excessive enzyme digestion of Navβ2,the correction of the abnormal expression and distribution of Nav1.1αin cortical and hippocampal neurons,as well as the subsequent regulation of neuronal excitability.
作者
刘慧
严国纪
吴嘉
王丹
习杨彦彬
李珊珊
Hui LIU;Guoji YAN;Jia WU;Dan WANG;YANGYanbin XI;Shanshan LI(Institute of Neuroscience;Experimental Teaching Center,Basic Medical College,Kunming Medical University,Kunming Yunnan 650500,China)
出处
《昆明医科大学学报》
CAS
2024年第2期23-31,共9页
Journal of Kunming Medical University
基金
云南省教育厅科学研究基金资助项目(2023Y0608)
云南省科技厅基础研究专项基金资助项目(202101AT070001)。
