晚发型阿尔茨海默病蛋白质组学中触珠蛋白的表达

Expression of haptoglobin in proteomic analysis of late-onset Alzheimer disease

目的建立晚发型阿尔茨海默病(LOAD)蛋白质组学技术体系,寻找并鉴定与LOAD发生有关的生物标记物。方法选择8例经病理证实为LOAD患者的颞叶脑皮质为LOAD组,另选择5例尸体解剖为正常老年人颞叶脑皮质为对照组。分别采用固相pH梯度双向凝胶电泳分离总蛋白质,凝胶经银染显色后,用图像分析软件进行比较分析、确定差异蛋白质点。将选取的差异蛋白质点进行胶内酶切,采用基质辅助激光解析-电离-飞行时间质谱及电喷雾电离串联质谱法进行质谱分析;搜索数据库鉴定蛋白质。结果分别获得两组脑组织双向电泳蛋白质组表达图谱,筛选并鉴定出表达有明显差异的蛋白质点11个,其中蛋白质点2触珠蛋白在LOAD组有明显上调。结论筛选并鉴定表达有明显差异的蛋白质点11个,可能成为具有临床诊断意义的LOAD潜在标记物,从而为阿尔茨海默病的早期诊断和治疗提供理论和实验依据。

Objective To establish the proteomic technology platform for Late-onset Alzheimer disease（LOAD） and screen out LOAD-related biological markers by proteome analysis. Methods Cerebral cortex of temporal lobes of 8 LOAD cases（LOAD group） and cortex of temporal lobe of 5 age-matched normal old persons（control group） were selected from autopsy cases. Proteins and peptides in cerebral cortex were separated by two-dimensional gel electrophoresis（2DE）. Differential proteins were identified by matrix assisted laser desorption ionization time of flight mass speetrometry（MALDI-TOF-MS） and electrospray ionization mass spectrometry（ESI-MS）. Differential proteomie expression in the cerebral cortex between LOAD patients and the control group was searched and studied from the data bank. Results Different 2-DE maps of the protein spots in the LOAD group and the control group gels were obtained. Eleven protein spots showed significantly different expression between the two groups of cerebral cortex samples. It was found that the expression of haptoglobin was increased in LOAD group compared with the control group. Conclusions These identified proteins may be potential markers related to Alzheimer disease pathology. Screening and identifying different protein spots may be helpful to finding new molecular markers for early diagnosis and treatment of the disease.