Peptide Biomarkers for Parkinson Disease

 描述（由申请人提供）：显然需要客观、可靠和可重复的生物标志物来辅助帕金森病（PD）的准确诊断，特别是在早期阶段，以及促进鉴别诊断和疾病监测。该提案旨在满足当前生物标志物研究的几个主要挑战，具体而言：1）与基于抗体的蛋白质测定相关的显著变化，2）基于血液的标志物的低灵敏度和特异性，以及3）早期阶段的PD检测。为了解决基于抗体的测定的问题，我们的策略是开发基于靶向质谱的技术，例如选择反应监测（SRM），以鉴定来源于蛋白质的独特肽标记物，所述蛋白质在先前的蛋白质组学分析中显示出前景，或者已知对PD发病机制至关重要，例如，人脑脊液（CSF）中的α-突触核蛋白、parkin和LRRK 2。为了促进基于血液的生物标志物的发现和验证，将在SRM分析之前分离中枢神经系统来源的血浆外泌体的特定群体，所述外泌体是最近被识别为在不同细胞或器官系统之间运输生物分子的运载物的微泡。独特的肽标记物将在几个大的、良好建立的群组中进行测试，例如，Udall中心附属于华盛顿大学和宾夕法尼亚大学，DATATOP（Deprenyl和生育酚抗氧化治疗帕金森综合征）和PPMI（帕金森进展标志物倡议），收集了横断面和纵向样本，沿着广泛的临床特征。最后，为了改善早期诊断，我们将使用两个由PD风险升高的受试者组成的队列（即，具有LRRK 2突变或嗅觉丧失/嗅觉减退的无症状受试者），目的是发现能够识别患有早期或运动前PD的受试者的生物标志物。为该项目设计的研究，如果成功，有可能产生一组生物标志物，这些生物标志物是稳健的，比目前可以实现的变化更少，并且在常规临床环境中容易获得体液。PD的早期诊断和进展的标志物对于了解如何阻止或减缓PD进展至关重要。

 DESCRIPTION (provided by applicant): Objective, reliable, and reproducible biomarkers are clearly needed to assist with accurate diagnosis of Parkinson disease (PD), especially at early stages, as well as for facilitating differential diagnosis and disease monitoring. The proposal is designed to meet several major challenges of current biomarker research, specifically: 1) significant variations associated with antibody-based protein assays, 2) low sensitivity and specificity of blood based markers, and 3) detection of PD at early stages. To address the problems of antibody-based assays, our strategy is development of targeted mass spectrometry-based techniques, such as selected reaction monitoring (SRM), to identify unique peptide markers derived from proteins either showing promise in previous proteomics profiling, or known to be critical to PD pathogenesis, e.g., α-synuclein, parkin and LRRK2, in human cerebrospinal fluid (CSF). To facilitate discovery and validation of blood based biomarkers, a specific population of central nervous system derived plasma exosomes, the cargo-carrying microvesicles recognized recently to transport biomolecules among different cells or organ systems, will be isolated before SRM analysis. The unique peptide markers will be tested in several large, well-established cohorts, e.g., Udall Centers affiliated with the University of Washington and University of Pennsylvania, DATATOP (Deprenyl and tocopherol antioxidative therapy of parkinsonism) and PPMI (Parkinson Progression Marker Initiative), with cross-sectional and longitudinal samples collected, along with extensive clinical characterization. Finally, to improve early diagnosis, we will make use of two cohorts consisting of subjects at elevated risk for PD (i.e., asymptomatic subjects with LRRK2 mutations or anosmia/hyposmia), with the goal of discovering biomarkers capable of identifying subjects with early or premotor PD. The studies designed for this project, if successful, have the potential to result in a panel(s of biomarkers that are robust, with less variation than can currently be achieved, and in a body fluid that is readily accessible in a regular clinical setting. Markers for early diagnosis and progression of PD are critical in understanding how to arrest or slow PD progression.