额颞叶痴呆的蛋白质组研究

摘要

目的 为深入理解额颞叶痴呆分子机制并寻找诊断治疗该疾病的蛋白质标记物,选取5例经病理证实的额颞叶痴呆患者与4例无神经系统疾病老年人尸检脑标本进行蛋白质组学研究.方法 死亡24 h内新鲜取材的尸检额叶、颞叶蛋白质以固相pH梯度等电聚焦为第一向,SDS-PAGE垂直电泳为第二向进行双向电泳(2-DE),图象分析软件Imagemaster 2D Elite分析电泳图谱,MALDI-TOF质谱或MALDI-TOF/TOF串联质谱鉴定蛋白质.结果 18种蛋白质的表达量在额颢叶痴呆患者与正常老年人显著不同.12个在额颞叶痴呆表达量上调的蛋白质被鉴定为3-磷酸甘油醛脱氢酶、尿嘧啶DNA糖苷水解酶、Cu-Zn超氧化物歧化酶、异柠檬酸脱氢酶亚单位、synaptotagmin I、Peroxiredoxin2、胶质纤维酸性蛋白、P25 alpha、烯酰辅酶A水合酶短链1、吡哆醇-5′-磁酸氧化酶、Mn超氧化物歧化酶、α-烯醇化酶;6个在额颞叶痴呆表达量下调的蛋白质被鉴定为抗氧化蛋白2(酸性钙离子依赖型磷脂酶A)、铁蛋白H链、谷氨酸脱氢酶、肽基脯氨酸顺反异构酶A、血清白蛋白前体、二氢嘧啶酶相关蛋白2.结论 额颞叶痴呆患者脑组织中神绛纤维缠结相关蛋白、氧应激蛋白、凋亡相关蛋白及重要代谢酶的表达发生变化,有助于深入理解额颞叶痴呆分子机制并有望在额颞叶痴呆的早期诊断及新药开发上发挥作用.%Objective To investigate molecular mechanisms of frontotemporal dementia (FTD). Methods Comparative proteomic analysis of brain proteins was employed to study 5 frontotemporal dementia patients compared to 4 controls. The brains of subjects who died without clinical or pathological involvement of nervous system and brains of frontotemporal dementia patients were obtained at autopsy. The brain proteins extracted with mixture of urea, CHAPS, DTT. IPG buffer and protease inhibitors were run immobilized pH gradient (IPG) isoelectric focusing electrophoresis as the first dimension,and then run vertical SDS-PAGE as the second dimension. The maps were visualized by silver staining or colloidal coomassive blue and analysised with Image Master 2D Elite software . The proteins of interest were in-gel digested and identified using MALDI-TOF mass spectrometry or MALDI-TOF/TOF tandem mass spectrometry . Results In the cases of FTD brains,18 protein spots were differentially expressed compared with age-matched non-demented control brains. 12 up-regulated proteins in FTD brains were identified as glyceraldehyde 3-phosphate dehydrogenase, uracil DNA glycosylase, human superoxide dismutase, isocitrate dehydrogenase subunit, synaptotagmin I, thioredoxin peroxidase 1, glial fibrillary acidic protein, P25 alpha, enoyl coenzyme A hydratase short chain 1, pyridoxine-5'-phosphate oxidase, Mn-superoxide dismutase,alpha enolase. 6 down-regulated proteins in FTD brains were identified as antioxidant protein 2, ferritin heavy chain, glutamate dehydrogenase precursor, peptidyl-prolyl cis-trans isomerase A, serum albumin precursor, dihydropyrimidinaserelated protein 2. Conclusions Some related-proteins of frontotemporal dementia proteins are quite useful for discovering the molecular mechanisms of FTD and may be helpful for diagnosis and treatment of corticobasal degeneration.