α-突触核蛋白通过Rab5B下调海马神经元膜表面NMDA受体含量及其介导的Ca^(2＋)内流和内向电流  

α-Synuclein reduces surface expressions of NMDA receptors and NMDA-invoked Ca^(2+) influx and inward current by upregulation of Rab5B in cultured primary hippocampal neurons

作　　者：于文娇 杨巍巍[1,2,3,4] 李昕 李旭冉[1,2] 陈敏 于顺[1,2,3,4] 

机构地区：[1]首都医科大学宣武医院神经生物学研究室,北京市老年病医疗研究中心,北京100053 [2]首都医科大学帕金森病临床诊疗与研究中心,北京100053 [3]帕金森病北京市重点实验室和教育部神经变性病重点实验室,北京100053 [4]国家老年疾病临床医学研究中心,北京100053 [5]桂林医学院附属医院神经科学实验室,广西桂林541001

出　　处：《首都医科大学学报》2017年第6期868-873,共6页Journal of Capital Medical University

基　　金：国家自然科学基金(81371200,81071014,81401042);北京市医院管理局“使命”计划专项经费资助(SML20150803);北京市科学技术委员会资助(Z161100005116011,Z171100000117013);北京市卫生和计划生育委员会“老年重大疾病关键技术研究”(PXM2017_026283_000002);广西自然科学基金(2014GXNSFAA118197)

摘　　要：目的研究α-突触核蛋白(α-synuclein,α-Syn)对原代海马神经元膜表面N-甲基-D-天门冬氨酸(N-methyl-D-aspartate,NMDA)受体含量和功能的影响及其机制。方法细胞外添加基因重组α-Syn,使其进入原代培养神经元细胞内,观察敲减Rab5B基因前后神经元膜表面NMDA受体(NMDAR)和Rab5B表达的变化;NMDA激活NMDAR,活细胞工作站测定神经元Ca^(2+)内流变化,全细胞膜片钳记录内向跨膜电流变化。结果α-Syn增加神经元Rab5B的表达,减少膜表面NMDAR含量,并因而抑制NMDA引起的Ca^(2+)内流及内向跨膜电流;敲减Rab5B可逆转α-Syn对NMDAR的下膜作用及功能的影响。结论α-Syn通过上调Rab5B而下调海马神经元膜表面NMDAR含量及其介导的Ca^(2+)内流及内向电流。Objective To investigate the effects of α-synuclein（α-Syn） on surface expressions and functions of N-methyl-D-aspartate（NMDA） receptors（NMDARs） in cultured primary hippocampal neurons.Methods Increased intracellular α-Syn levels were realized by extracellular addition of recombinant human α-Syn to the culture medium of rat primary hippocampal neurons.Expressions of surface NMDARs and Rab5B were observed by fluorescence immunocytochemistry and Western blotting.Rab5B antisense oligonucleotides were applied to suppress Rab5B expression.Live cell imaging system and whole-cell patch-clamp recording were used to record NMDA-evoked Ca^（2＋） influx and inward currents.Results Neurons treated with α-Syn displayed increased Rab5B,decreased surface NMDARs,and reduced NMDA-evoked Ca^（2＋） influx and inward currents.The above α-Syn effects were inhibited by suppression of Rab5B expression.Conclusion α-Syn reduces the surface expression and functions of NMDARs by increasing Rab5B expression.

关 键 词：Α-突触核蛋白 NMDA受体 Rab5B 神经元 海马 

分 类 号：Q189[生物学—神经生物学]