Aβ42寡聚体对突触内外谷氨酸受体表达的影响
Effects of Aβ42 oligomers on expression of synaptic and extrasynaptic glutamate receptors
陈秋旋 1贺娅旎 1刘玉香 1冯一 1张珂珂 1魏伟1
作者信息
- 1. 暨南大学基础医学与公共卫生学院病理生理学系,国家中医药管理局病理生理实验室,广东 广州 510632
- 折叠
摘要
目的:通过体内外实验探讨阿尔茨海默病关键发病分子β-淀粉样蛋白42寡聚体(Aβ42Os)作用下离子型谷氨酸受体N-甲基-D-天冬氨酸受体(NMDAR)亚基(NR2A、NR2B和NR1)和代谢型谷氨酸受体5(mGluR5)在突触内外的表达分布变化.方法:(1)用不同浓度的Aβ42Os处理乳小鼠原代神经元,Western blot和免疫荧光染色检测原代神经元中mGluR5和NMDAR的表达和分布情况.(2)在C57BL/6小鼠侧脑室立体定位注射不同浓度的Aβ42Os,Western blot检测海马组织中mGluR5和NMDAR在突触内外的蛋白水平,以及mGluR5下游磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(PKB/AKT)信号通路相关蛋白、钙信号下游通路相关蛋白和突触相关蛋白的表达.结果:(1)高浓度Aβ42Os处理原代小鼠神经元增加mGluR5表达(P<0.01),减少NR2A、NR2B和NR1表达(P<0.01);引起mGluR5膜表面聚集,而使NR2A、NR2B和NR1膜表面表达分布减少.(2)高浓度Aβ42Os引起小鼠海马组织中突触mGluR5表达增加(P<0.01),NR2A(P<0.05)和NR2B(P<0.01)表达减少,突触外NR2B表达增加(P<0.01);抑制PI3K表达及AKT和细胞外信号调节激酶(ERK)磷酸化,过度激活钙/钙调蛋白依赖性蛋白激酶IIα(CaMKIIα);引起突触后致密蛋白95、亲棘蛋白(spinophilin)、突触小泡蛋白(synaptophysin)和微管相关蛋白2表达减少(P<0.01).结论:(1)高浓度Aβ42Os引起神经元突触mGluR5过度聚集,NR2A、NR2B和NR1表达减少,而突触外NR2B表达增加.(2)高浓度Aβ42Os抑制PI3K/AKT和ERK信号通路,过度激活CaMKIIα通路,损伤突触结构.
Abstract
AIM:To explore the expression and distribution of synaptic and extrasynaptic glutamate receptors under the action of amyloid β-protein 42 oligomers(Aβ42Os)in Alzheimer disease.METHODS:In vitro,primary neu-rons from neonatal mice were treated with different concentrations of Aβ42Os.In vivo,Aβ42Os were stereotaxically injected into the lateral ventricle of C57BL/6 mice.Western blot was used to detect the protein levels of metabotropic gultamate re-ceptor 5(mGluR5)and N-methyl-D-aspartate receptor(NMDAR)subunits(NR2A,NR2B and NR1)in mouse primary neurons and mice.Immunofluorescence staining was performed to observe the distribution of mGluR5 and NMDAR.Addi-tionally,Western blot was employed to examine the expression of mGluR5 downstream phosphatidylinositol 3-kinase(PI3K)/protein kinase B(PKB/AKT)signaling pathway-related proteins,calcium signaling pathway-related proteins and synapse-related proteins in mouse hippocampal tissues.RESULTS:(1)High concentrations of Aβ42Os increased mGluR5 expression in mouse primary neurons,but reduced the expression of NR2A,NR2B and NR1(P<0.01).Treatment of pri-mary neurons with high concentration of Aβ42Os resulted in aggregation of mGluR5 on the membrane surface,and re-duced the expression of NR2A,NR2B and NR1 on the membrane surface.(2)High concentration of Aβ42Os increased the expression of synaptic mGluR5 in mouse hippocampal tissues(P<0.01),but reduced the expression of synaptic NR2A(P<0.05)and NR2B(P<0.01)and increased the expression of extrasynaptic NR2B(P<0.01).High concentration of Aβ42Os inhibited the expression of PI3K and the phosphorylation of AKT and extracellular signal-regulated kinase(ERK),and overactivated calcium/calmodulin-dependent protein kinase IIα(CaMKIIα).High concentration of Aβ42 decreased the expression of postsynaptic density protein 95,spinophilin,synaptophysin and microtubule-associated protein 2(P<0.01).CONCLUSION:(1)High concentrations of Aβ42Os increase mGluR5 expression and decrease NR2A,NR2B and NR1 expression in synapse,along with an increase in extrasynaptic NR2B.(2)High concentrations of Aβ42Os inhibit the PI3K/AKT and ERK signaling pathways,overactivated the CaMKIIα pathway,and destroyed the synaptic structures.
关键词
阿尔茨海默病/β-淀粉样蛋白42寡聚体/代谢型谷氨酸受体5/N-甲基-D-天冬氨酸受体/突触Key words
Alzheimer disease/amyloid β-protein 42 oligomers/metabotropic glutamate receptor 5/N-methyl-D-aspartate receptors/synapse引用本文复制引用
基金项目
广东省自然科学基金(2023A1515010585)
广州市科技计划(201904010040)
出版年
2024
国家科技期刊平台
NSTL
万方数据