阿尔茨海默病潜在血浆蛋白标志物的验证研究

A confirmatory study on potential plasma protein markers for Alzheimer's disease

目的比较阿尔茨海默病(Alzheimer's disease,AD)患者与正常对照者血浆蛋白表达差异,寻找具有筛查或诊断意义的蛋白标志物或蛋白组合。方法2016年至2018年从无锡市精神卫生中心和上海市精神卫生中心收集98例AD痴呆患者(DAT组)、102例轻度认知损害患者(MCI组)和101名正常对照(对照组)的血浆样本,采用液相芯片技术(xMAP)检测所有血浆样本50种血浆蛋白的表达水平,采用SPSS 20.0软件对数据进行方差分析、回归分析、判别分析和ROC分析。结果(1)与对照组相比,DAT组有26种血浆蛋白上调、4种蛋白下调,MCI组有6种蛋白上调、4种蛋白下调(均P<0.05);与对照组相比,MCI组和DAT组均上调的有凝集素(Clust)[613.41(278.89),761.76(358.60),473.01(321.73)]、半胱氨酸蛋白酶抑制剂C(Cys C)[691.88(441.34),852.28(551.75),548.64(545.28)]、甲状腺素运载蛋白(TTR)[207.10(168.60),220.95(151.20),152.89(162.70)]、补体家族H因子(Com FH)[331.67(218.37),361.69(124.64),225.79(236.82)]、可溶性细胞间黏附分子(sICAM1)[109.30(49.47),137.21(50.36),87.06(57.59)]和载脂蛋白E(APOE)[79.33(78.13),79.31(68.85),54.88(67.34)]等6种蛋白,MCI组和DAT组均下调的为血清淀粉样蛋白P组分(SAP)[121.23(311.31),92.39(156.62),125.00(242.82)]。(2)采用差异分析、回归分析和判别分析筛选出3套蛋白组合,分别包含8种蛋白、9种蛋白和7种蛋白,其中SAP、血管紧张素(AGT)、骨桥蛋白(OPN)和补体C4(Com C4)为4种最常入选的蛋白。(3)3套蛋白组合甄别AD正确率为67.4%~71.4%、甄别DAT正确率为82.4%~88.4%,甄别MCI正确率为60.6%~63.5%。结论AD患者存在Clust、Cys C、TTR、Com FH、sICAM1、APOE等蛋白上调和SAP蛋白下调,这些差异蛋白的组合有助于早期诊断AD痴呆。SAP、AGT、OPN和Com C4有可能成为AD早期筛查或诊断的潜在标志物。

Objective To investigate the plasma differential protein expressions between patients with Alzheimer's disease(AD)and normal controls,and to search plasma protein markers or protein combinations with screening or diagnostic significance.Methods Plasma samples from 98 patients with dementia of Alzheimer type(DAT),102 patients with mild cognitive impairment(MCI)and 101 normal controls(NC)were collected from Wuxi Mental Health Center and Shanghai Mental Health Center from 2016 to 2018.The expression levels of 50 kinds of plasma proteins in all plasma samples were detected by Milliplex MAP assays(xMAP).Analysis of variance,regression analysis,discriminant analysis,and ROC analysis on the data were performed using SPSS 20.0 software.Results (1)Compared with the NC group,26 plasma proteins were up-regulated and 4 proteins were down-regulated in DAT group,while 6 proteins were up-regulated and 4 proteins were down-regulated in MCI group(all P<0.05).Compared with the NC group,6 proteins were upregulated in both MIC group and DAT group,which were clusterin(Clust)(613.41(278.89),761.76(358.60),473.01(321.73)),cystatin C(Cys C)(691.88(441.34),852.28(551.75),548.64(545.28)),transthyretin(TTR)(207.10(168.60),220.95(151.20),152.89(162.70)),complement factor H(Com FH)(331.67(218.37),361.69(124.64),225.79(236.82)),soluble intercellular adhesion molecule-1(sICAM1)(109.30(49.47),137.21(50.36),87.06(57.59)),and apolipoprotein E(APOE)(79.33(78.13),79.31(68.85),54.88(67.34)).The serum amyloid P component(SAP)was downregulated in both DAT and MCI groups(121.23(311.31),92.39(156.62),125.00(242.82))compared with NC group.(2)Three sets of protein combination were screened by differential analysis,regression analysis,and discriminant analysis,including 8 proteins,9 proteins and 7 proteins,respectively.And SAP,angiotensin(AGT),osteopontin(OPN),and complement C4(Com C4)were the compared with NC group most frequently selected protein.The screening correct rate of three protein combinations were respectively 67.4%-71.4%for AD,82.4%-88.4%for DAT,and 60.6%-63.5%for MCI.Conclusion sA variety of plasma proteins such as Clust,Cys C,TTR,Com FH,sICAM1,APOE are upregulated,while SAP is downregulated in AD patients.These differential protein combinations can help with early diagnosis of dementia with Alzheimer type.SAP,AGT,OPN and Com C4 may be potential markers for early screening or diagnosis of AD.