Oláh Zita, Kálmán János, Tóth Melinda E, Zvara Ágnes, Sántha Miklós, Ivitz Eszter, Janka Zoltán, Pákáski Magdolna
Department of Psychiatry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
Laboratory of Animal Genetics and Molecular Neurobiology, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary.
J Alzheimers Dis. 2015;44(4):1303-12. doi: 10.3233/JAD-140141.
Clinical diagnosis of Alzheimer's disease (AD) relying on symptomatic features has a low specificity, emphasizing the importance of the pragmatic use of neurochemical biomarkers. The most advanced and reliable markers are amyloid-β (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) with relatively high levels of sensitivity, specificity, and diagnostic accuracy. Recent advances within the field of proteomics offer the potential to search for novel biomarkers in CSF by using modern methods, such as microarrays. The purpose of this study was to identify pathognostic proteins in CSF obtained from patients whose clinical AD diagnosis was confirmed by the "core" biomarkers. CSF samples were obtained from 25 AD patients and 25 control individuals. The levels of Aβ42, t-tau, and p-tau were measured by ELISA. In the microarray experiments, ultrasensitive slides representing of 653 antigens were used. Apolipoprotein E genotyping was also determined. A decrease of seven CSF proteins in AD were found, four of them (POLG, MGMT, parkin, and ApoD) have a protective function against neuronal death, while the remaining three proteins (PAR-4, granzyme B, Cdk5) trigger multiple pathways facilitating neuronal cell death. Since these proteins from CSF samples could not be identified by western blot, their decreased levels in AD patients were not verified. Our results provide new information of pathognostic importance of POLG and granzyme B in AD. Although the function of MGMT, parkin, ApoD, PAR-4, and Cdk5 was previously known in AD, the findings presented here provide novel evidence of the significance of CSF analysis in the mapping of the AD pathomechanism.
依靠症状特征对阿尔茨海默病（AD）进行临床诊断的特异性较低，这凸显了实际应用神经化学生物标志物的重要性。最先进且可靠的标志物是脑脊液（CSF）中的β淀粉样蛋白（Aβ42）、总tau蛋白（t-tau）和磷酸化tau蛋白（p-tau），其具有相对较高的敏感性、特异性和诊断准确性。蛋白质组学领域的最新进展为通过使用微阵列等现代方法在脑脊液中寻找新型生物标志物提供了可能。本研究的目的是在临床AD诊断通过“核心”生物标志物得到证实的患者的脑脊液中鉴定出病理诊断蛋白。从25名AD患者和25名对照个体中获取脑脊液样本。通过酶联免疫吸附测定法（ELISA）测量Aβ42、t-tau和p-tau的水平。在微阵列实验中，使用了代表653种抗原的超敏载玻片。还进行了载脂蛋白E基因分型。发现AD患者的脑脊液中有7种蛋白质减少，其中4种（聚合酶γ（POLG）、O6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）、帕金蛋白和载脂蛋白D（ApoD））具有对神经元死亡的保护作用，而其余3种蛋白质（凋亡相关因子4（PAR-4）、颗粒酶B、细胞周期蛋白依赖性激酶5（Cdk5））触发促进神经元细胞死亡的多种途径。由于这些来自脑脊液样本的蛋白质无法通过蛋白质印迹法鉴定，因此未证实其在AD患者中的水平降低。我们的结果提供了关于POLG和颗粒酶B在AD中病理诊断重要性的新信息。尽管MGMT、帕金蛋白、ApoD、PAR-4和Cdk5在AD中的功能先前已为人所知，但此处呈现的研究结果为脑脊液分析在AD发病机制图谱绘制中的重要性提供了新证据。
