中文摘要：

目的以老年性痴呆（AD）大鼠为研究对象，应用蛋白质组学方法在血清中筛选与AD密切相关的蛋白质，为研究AD的发病机制提供理论支持。方法通过Morris水迷宫记忆行为学筛选符合痴呆标准的AD大鼠模型，收集AD组大鼠及假手术组大鼠的血清后，去除血清中的高丰度蛋白质并进行蛋白质浓度的测定，之后进行双向凝胶电泳，挑选差异最为明显的蛋白质点进行肽质量指纹图谱分析，经数据库查询，鉴定差异蛋白质。结果经观察二维凝胶电泳图谱后，发现AD组大鼠与假手术组大鼠的血清中共有10个差异明显的蛋白质点，选取了2个最为明显的蛋白质点进行鉴定，分别为：血浆视黄醇结合蛋白前体，补体成分4，基因2（C4b）。结论C4b是新发现的与AD相关的蛋白质，有可能是潜在的AD标志物，有助于更深刻地理解AD的发病机制。

英文摘要：

Objective Alzheimer＇s disease（AD） is a common and devastating disease and there is no readily available biomarker to aid diagnosis or to monitor disease progression. This study is to further understand the pathogenesis of Alzheimer＇s disease and seek new biomarkers for AD. Methods AD rats made by Aβ1-40 were assessed using the Morris water maze method. Sera of two groups were collected and albumin, IgG and sodium chloride were removed from the serum before concentration. Two-dimensional electrophoresis（2-DE） was performed on serum protein. Altered proteins were identified by matrix assisted laser desorption/ionization time of flight mass spectrometry（MALDI-TOF-MS）. Results Compared with untreated samples, 10 altered proteins were found through 2-DE and all of them were down-regulated of which 2 were identified by MALDI-TOF-MS to be plasma retinol-binding protein precursor and complement component 4, gene 2 （C4b）. Conclusion C4b may be the biomarker of AD and it may be helpful to understand the pathogenesis of AD.