Proteomic Biomarker Discovery in PD

描述（由申请人提供）：帕金森病（PD）是一种与年龄相关的神经退行性疾病，以黑质纹状体多巴胺能神经元的选择性丧失为特征。帕金森病的病因目前尚不清楚，但假设涉及遗传易感性和环境毒物。尽管不同的启动因素，一个共同的生化途径被假定引发表型相似的临床综合征和神经病理状态。这种趋同的病理生理学假说认为，特定的下游生化途径介导了帕金森病中观察到的突触丧失、细胞损伤和死亡。我们假设这些病理生理变化将在共享这些信号通路的外周腔室中表现出来。具体来说，我们认为外周白细胞将报告PD的致病过程，并将反映在蛋白质水平和功能的改变上。因此，这些变化将作为PD诊断和进展的重要生物标志物，并将为其病理生理学和潜在治疗提供有价值的见解。我们建议在选定的临床人群中利用人类外周白细胞的探索性方法，并结合有针对性的方法进行验证。在拟议的研究中，我们将使用探索性蛋白质组学方法暂时鉴定PD（非痴呆）、晚发性阿尔茨海默病（LOAD）、轻度认知障碍（MCI）患者和年龄匹配的对照组（非痴呆）受试者白细胞中的差异蛋白表达。目前，我们每组共有12名受试者的白细胞蛋白样本，所有受试者的临床阶段和神经心理测试都有很好的特征。这些样品的二维凝胶已经完成。在这项研究中，我们将使用基于计算机的分析（Progenesis软件）来鉴定差异表达蛋白。此外，我们建议在四组中每组共25名受试者中再取样13名受试者/组。在探索性分析之后，将使用标准蛋白质组学方法在初始队列以及PD和对照受试者（各15名受试者）的单独队列中验证这些谱。目前，我们有30名受试者的白细胞样本，并准备验证已识别的生物标志物。我们假设这些方法将共同识别外周白细胞中的蛋白质谱，将PD患者与非PD患者进行分类。我们相信这些独特和创新的研究将提供丰富的问题组学信息，这些信息将转化为改进PD诊断和治疗干预评估。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is an age-related neurodegenerative disorder typified by selective loss of nigrostriatal dopaminergic neurons. The etiology of Parkinson's disease is currently unknown but hypothesized to involve both genetic vulnerability and environmental toxicants. Despite disparate initiating factors a shared biochemical pathway is posited to elicit a phenotypically similar clinical syndrome and neuropathological state. This convergent pathophysiological hypothesis asserts that specific downstream biochemical pathways mediate the synaptic loss, cellular injury, and death observed in Parkinson's disease. We posit that these pathophysiological changes will be manifest in peripheral compartments, which share these signaling pathways. Specifically, we propose that peripheral leukocytes will report the PD pathogenic process and will be reflected in alterations in protein levels and functions. As such, these changes will serve as important biomarkers for PD diagnosis and progression and will provide valuable insights into its pathophysiology and potential therapeutics. We propose to utilize exploratory approaches on human peripheral leukocytes within select clinical populations, coupled with directed methodologies for validation. In the proposed study we will use an exploratory proteomics approach to provisionally identify differential protein expression in leukocytes from patients with PD (non-demented), late onset Alzheimer's disease (LOAD), mild cognitive impairment (MCI) and from age-matched control (non-demented) subjects. We currently have leukocyte protein samples from a total of 12 subjects per group and all subjects have been well characterized with respect to clinical stage and neuropsychological testing. 2-dimensional gels have been completed for these samples. In this study we will use computer-based analysis (Progenesis software) to identify differentially expressed proteins. Furthermore, we propose to sample an additional 13 subjects/group for a total number of 25 subjects in each of the four groups. Following exploratory analyses, these profiles will be validated using standard proteomics methods in the initial cohort as well as in a separate cohort of PD and control subjects (15 subjects each). We currently have leukocyte samples from all 30 subjects in this second cohon and prepared to validate identified biomarkers. We hypothesize that these approaches will in aggregate identify profiles of proteins within peripheral leukocytes that will categorize PD subjects from non-PD subjects. We believe that these unique and innovative studies will provide a wealth of proleomics information that will translate to improved PD diagnosis and evaluation of therapeutic interventions.