Laterza Omar F, Modur Vijay R, Crimmins Dan L, Olander Jitka V, Landt Yvonne, Lee Jin-Moo, Ladenson Jack H
Department of Pathology and Immunology, Division of Laboratory Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
Clin Chem. 2006 Sep;52(9):1713-21. doi: 10.1373/clinchem.2006.070912. Epub 2006 Jul 20.
The diagnosis of diseases leading to brain injury, such as stroke, Alzheimer disease, and Parkinson disease, can often be problematic. In this study, we pursued the discovery of biomarkers that might be specific and sensitive to brain injury.
We performed gene array analyses on a mouse model to look for biomarkers that are both preferentially and abundantly produced in the brain. Via bioinformatics databases, we identified the human homologs of genes that appeared abundant in brain but not in other tissues. We then confirmed protein production of the genes via Western blot of various tissue homogenates and assayed for one of the markers, visinin-like protein 1 (VLP-1), in plasma from patients after ischemic stroke.
Twenty-nine genes that were preferentially and abundantly expressed in the mouse brain were identified; of these 29 genes, 26 had human homologs. We focused on 17 of these genes and their protein products on the basis of their molecular characteristics, novelty, and/or availability of antibodies. Western blot showed strong signals in brain homogenates for 13 of these proteins. Tissue specificity was tested by Western blot on a human tissue array, and a sensitive and quantitative sandwich immunoassay was developed for the most abundant gene product observed in our search, VLP-1. VLP-1 was detected in plasma of patients after stroke and in cerebrospinal fluid of a rat model of stroke.
The use of relative mRNA production appears to be a valid method of identifying possible biomarkers of tissue injury. The tissue specificity suggested by gene expression was confirmed by Western blot. One of the biomarkers identified, VLP-1, was increased in a rat model of stroke and in plasma of patients after stroke. More extensive, prospective studies of the candidate biomarkers identified appear warranted.
导致脑损伤的疾病，如中风、阿尔茨海默病和帕金森病，其诊断常常存在问题。在本研究中，我们致力于发现可能对脑损伤具有特异性和敏感性的生物标志物。
我们在小鼠模型上进行基因芯片分析，以寻找在脑中优先且大量产生的生物标志物。通过生物信息学数据库，我们鉴定出在脑中大量出现但在其他组织中未出现的基因的人类同源物。然后，我们通过对各种组织匀浆进行蛋白质免疫印迹来确认这些基因的蛋白质表达，并对缺血性中风患者血浆中的一种标志物，即类视黄醛蛋白1（VLP-1）进行检测。
鉴定出29个在小鼠脑中优先且大量表达的基因；在这29个基因中，26个有人类同源物。基于它们的分子特征、新颖性和/或抗体的可获得性，我们重点研究了其中17个基因及其蛋白质产物。蛋白质免疫印迹显示其中13种蛋白质在脑匀浆中有强烈信号。通过对人类组织芯片进行蛋白质免疫印迹测试组织特异性，并针对我们在研究中观察到的最丰富的基因产物VLP-1开发了一种灵敏且定量的夹心免疫测定法。在中风患者的血浆和中风大鼠模型的脑脊液中检测到了VLP-1。
使用相对mRNA产量似乎是鉴定组织损伤可能生物标志物的有效方法。基因表达所提示的组织特异性通过蛋白质免疫印迹得到了证实。所鉴定的生物标志物之一VLP-1，在中风大鼠模型和中风患者血浆中有所增加。对所鉴定的候选生物标志物进行更广泛的前瞻性研究似乎是必要的。
