摘要
目的研究Aβ寡聚体(Amyloid-beta oligomers,Aβoligomers,AβOs)在阿尔茨海默氏病(Alzheimer Disease,AD)患者中的表达情况,用不同聚集形式的Aβ处理拟老年痴呆细胞模型中肿瘤坏死因子-α(Tumor necro-sis factor-α,TNF-α)、炎性趋化因子单核细胞趋化蛋白1(Monocyte chemoattractant protein 1,MCP-1/CCL-2),巨噬细胞炎性蛋白-1α(Macrophage inflammatory protein-1α,MIP-1α/CCL-3)及神经型尼古丁乙酰胆碱受体(Neuronal nico-tinic acetylcholine receptors,nAChRs)的表达。探讨炎性因子及nAChRs与Aβ寡聚体在阿尔茨海默氏病发病机制中的作用。方法应用免疫组织化学方法检测AD患者(海马结构、颞叶及额叶皮质)Aβ寡聚体的表达。Elisa检测拟老年痴呆细胞模型中各组细胞TNF-α、MCP-1、MIP-1α的表达。Western blotting检测拟老年痴呆细胞模型中各组细胞α3、α7nAChRs的表达。结果 AβOs主要在神经细胞内表达,齿状回颗粒细胞、海马CA1-CA4锥体细胞及内嗅区皮质各层神经元胞体及突起内均见棕黄色粒状阳性表达,此外,小血管壁也见AβOs阳性表达。与老龄对照者相比,AD患者海马各区锥体细胞及内嗅区皮质各层神经元AβOs表达明显增强,半定量分析显示平均灰度值显著降低,差异有统计学意义(P<0.05,P<0.01)。采用1mol/L浓度的Aβ1-42单体、纤丝体及寡聚体处理SH-SY5Y细胞48h后与对照组相比,Aβ寡聚体处理组α3、α7nAChRs蛋白表达水平明显降低,炎性因子明显升高(P<0.05)。结论 Aβ寡聚体能升高TNF-α、MCP-1、MIP-1α,加速Aβ沉积,形成恶性循环的慢性炎症过程,降低神经型尼古丁乙酰胆碱受体α3、α7nAChRs的表达,说明AD发病机制中可溶性、呈寡聚状态的AβOs可能是引起AD神经元功能失调的主要神经毒性形式。
Objective To investigate the expressions and change of the Aβ oligomers in the brains of patients with Alzheimer＇s disease,and the expressions of TNF-α,MCP-1,MIP-1α and nAChRs in Alzheimer＇s disease cells model treated with diffenent Aβ aggregate forms.And to dicuss the role of them in the pathogenesis of AD.Methods Immunohistochemistry was used to determine the expressions of Aβ oligomers in the hippocampus,temporal cortex and frontal cortex of patients with AD and age-matched control subjects.ELISA was used to determine TNF-α,MCP-1,and MIP-1 expressions.Western blotting was used to determine α3,α7nAChRs expressions in each group cells in the Alzheimer＇s disease cellsmodel.Results The AβOs-like immunoreactivity was mainly expressed in cells.The expression of AβOs were observed in granular cells in the dentate gyrus,in axons of neunons in the hippocampus CA1-CA4 and the entorhinal cortex,as well as blood vessel walls of brains.As compared to control cases,increased expression of AβOs was detected in AD brains.When SHSY-5Y cells were treated with 1mol/L Aβ-oligomers,-monomer or-fibril for 48h,the significantly decreased protein levels of α3 and α7nAChR subunits and the increased levels of inflammatory fators were detected in the cultured cells treated with Aβ-oligomers as compared to the cells exposed to Aβ-monomer and-fibril.Conclusion The expressions of TNF-α,MCP-1 and MIP-1α were increased by Aβ Oligomers.The protein expressions of α3 and α7nAChRs were decreased by Aβ Oligomers,and AβOs maybe are the most important toxic form in the pathogenesis of AD.
出处
《中风与神经疾病杂志》
CAS
CSCD
北大核心
2011年第6期484-487,共4页
Journal of Apoplexy and Nervous Diseases
基金
国家自然科学基金资助项目(30870986)
贵阳市科学技术计划项目[(2009)3-012]
贵阳医学院研究生教育创新基地建设专项经费(2009-2011)
