Identification and Verification of S-Nitrosylated Proteins in Bodily Fluids as Biomarkers for Parkinson's Disease and Lewy Body Dementia

帕金森病(PD)和路易体痴呆(LBD)表现为错误折叠的α- 突触核蛋白(αsyn)。关于LBD的诊断，路易体痴呆(DLB)患者可能表现出认知能力 而其他患者，初步诊断为伴有运动障碍的帕金森病 症状，后来进展为帕金森病伴痴呆(PDD)。然而，没有特定的生物标志物可以识别 在临床症状出现前有帕金森病或腰椎病风险的患者，或客观监测运动-或 评估疾病严重程度和进展的非运动性负担(如痴呆症和抑郁症)。此外， 阿尔茨海默病(AD)和阿尔茨海默病(AD)在临床和神经病理特征上的显著重叠 在某些情况下，LBD会使这些疾病的鉴别诊断在一生中特别具有挑战性。在……里面 PD、LBD和AD、突触损伤和神经元损伤至少部分是由于过量产生 由有毒形式的低聚αSYN或Aβ产生的活性氧和氮物种(ROS/RNS)。我们 先前证明RNS可以触发异常蛋白S-亚硝化(SNO-蛋白形成)， 导致突触/神经元损伤。我们的数据为S-帕金、PINK1、DJ-1、 Uch-L1在散发性PD和LBD的疾病相关神经元损伤中起致病作用。 具体地说，我们证明了预防异常蛋白S-亚硝化可以改善线粒体。 细胞和动物模型中的功能障碍、蛋白质错误折叠、突触损伤和神经元丢失 显示折叠错误的αSYN或Aβ。此外，我们最近发现SNO-蛋白水平显著升高， 包括SNO-DJ-1和SNO-UCHL1，在PD和LBD合并核病患者的脑脊液和血清中。 因此，我们建议在生物体液(即脑脊液和血清)中建立SNO-蛋白作为潜在的生物标志物。 作为PD/LBD的疾病诊断、进展和严重程度的指标。我们将不偏不倚地聘用 用于开发生物化学标志物的筛选方法以及先前鉴定的SNO-蛋白 PD/LBD，区别于AD。在成功完成建议的研究后，我们会设立一个 明确的使用背景(COU)的诊断/预后生物标志物与SNO-蛋白，以支持富集性 PD和LBD临床研究/试验人群；因此，这些SNO生物标志物及其详细方法 检测将准备进入生物标记物开发的下一阶段(即分析验证) 进程。因此，我们将利用蛋白质组学的方法在患者血清和脑脊液中鉴定新的SNO-蛋白 方法(R61/Aim#1)，建立基于ELISA的这些SNO蛋白的分析(R61/Aim#2)，并检查是否 血清和脑脊液中sNO蛋白可作为PD/LBD的潜在诊断或预后生物标志物 取自人类患者(R61/AIM#3和R33/AIM#4)。

Parkinson’s disease (PD) and Lewy body dementia (LBD) manifest pathological deposition of misfolded α- synuclein (αSyn). Concerning LBD diagnoses, dementia with Lewy bodies (DLB) patients may show cognitive decline and dementia from the onset of the disease, while other patients, initially diagnosed as PD with motor symptoms, later progress to PD with dementia (PDD). However, there are no specific biomarkers to identify patients at risk for PD or LBD prior to the appearance of clinical symptoms, or to objectively monitor motor- or non-motor (e.g., dementia and depression) burdens to assess disease severity and progression. Moreover, significant overlaps in clinical and neuropathological characteristics between Alzheimer’s disease (AD) and LBD can make differential diagnosis of these conditions in some cases particularly challenging during life. In PD, LBD and AD, synaptic injury and neuronal damage result at least in part from excessive generation of reactive oxygen and nitrogen species (ROS/RNS) engendered by toxic forms of oligomeric αSyn or Aβ. We previously demonstrated that RNS can trigger aberrant protein S-nitrosylation (SNO-protein formation), resulting in synaptic/neuronal damage. Our data provide evidence that S-nitrosylation of Parkin, PINK1, DJ-1, and Uch-L1 each plays a causative role in disease-related neuronal damage in sporadic human PD and LBD. Specifically, we demonstrate that prevention of aberrant protein S-nitrosylation ameliorates mitochondrial dysfunction, protein misfolding, synaptic damage, and neuronal loss in both cell-based and animal models manifesting misfolded αSyn or Aβ. Moreover, we recently found significantly elevated levels of SNO-proteins, including SNO-DJ-1 and SNO-UchL1, in CSF and serum of patients with PD and LBD synucleinopathies. Hence, here we propose to establish SNO-Proteins as potential biomarkers in biofluids (i.e., CSF and serum), serving as indicators of disease diagnosis, progression, and severity to PD/LBD. We will employ unbiased screening approaches as well as previously identified SNO-proteins to develop biochemical biomarkers for PD/LBD, distinguishable from AD. Upon successful completion of the proposed studies, we will establish a clear Context-of-Use (COU) for a diagnostic/prognostic biomarker with SNO-proteins to support enrichment of PD and LBD clinical study/trial populations; thus, these SNO biomarkers and their detailed methods of detection will be ready to enter the next phase (i.e., analytical validation) of the biomarker development process. Accordingly, we will identify novel SNO-proteins in patient serum and CSF using proteomics approaches (R61/Aim #1), develop ELISA-based assays for these SNO-proteins (R61/Aim #2), and examine if SNO-proteins can serve as potential diagnostic or prognostic biomarkers for PD/LBD using serum and CSF obtained from human patients (R61/Aim #3 and R33/Aim#4).