Understanding Mechanisms of a-synuclein pathology

项目总结-项目2：了解α -突触核蛋白病理学机制 α-突触核蛋白的遗传和生化异常直接参与了家族性和家族性遗传病的发病机制， 帕金森氏病（PD）的症状α-突触核蛋白诱导的细胞凋亡的潜在机制 神经退行性变的研究知之甚少。α-突触核蛋白家族性突变以及氧化和 亚硝化应激部分地通过增强的寡聚化、原纤化和 聚合来在上一个供资周期，我们与项目1合作， 受体酪氨酸激酶c-Abl可能参与PD的发病。从这些研究中， 令人兴奋的初步发现，c-Abl在酪氨酸39磷酸化α-突触核蛋白。然而，潜在的角色 酪氨酸39 α-突触核蛋白和c-Abl激活在PD发病机制中的作用尚未探讨。我们会研究 α-突触核蛋白酪氨酸39磷酸化和c-Abl激活在α-突触核蛋白致DA神经元死亡中的作用 突触核蛋白，以及它们在体外和体内α-突触核蛋白聚集中的作用。随着蛋白质组学核心D， 临床核心B和神经病理学核心C，我们将研究磷酸化水平是否 α-突触核蛋白酪氨酸39位的突变可以作为α-突触核蛋白诱导的脑梗死的进展和/或病理标志物。 神经变性和α-突触核蛋白病理学的研究。在这些研究中，我们将评估 α-突触核蛋白酪氨酸39磷酸化和人A53 T α-突触核蛋白c-Abl的激活状态 转基因模型、腺相关病毒-WT或具有DA神经元损失的A53 T α-突触核蛋白模型和人 通过磷酸化特异性酪氨酸39 α-突触核蛋白抗体和MRM从PD患者的死后组织 （多反应监测）质谱法。错误折叠的α-突触核蛋白的细胞间传递可能 在散发性PD中DA能神经元的变性中起重要作用， 内源性α-突触核蛋白向原纤维中的募集和腐败是未知的。自从我们的初步数据 提示c-Abl对α-突触核蛋白的酪氨酸39磷酸化促进了α-突触核蛋白的纤维化，我们 将研究WT与磷酸缺陷型Y39 F和磷酸模拟α-突触核蛋白Y39 E的能力，以及 α-突触核蛋白PFF模型中细胞间传递c-Abl缺陷和DA神经元变性 偶发性PD。最后，我们将探讨α-突触核蛋白PFF在退行性DA中诱导的蛋白质组学变化 神经元通过先进的spike-in质谱方法结合SILAM（稳定同位素标记 哺乳动物）。这些研究将为α-突触核蛋白的发病机制提供新的见解 诱导的神经变性，并可能导致新的治疗靶点和生物标志物的发展， PD的治疗。

PROJECT SUMMARY - PROJECT 2: UNDERSTANDING MECHANISMS OF α -SYNUCLEIN PATHOLOGY Genetic and biochemical abnormalities of α-synuclein are directly implicated in the pathogenesis of familial and sporadic forms of Parkinson's disease (PD). The underlying mechanisms of α-synuclein-induced neurodegeneration are poorly understood. Familial mutations in α-synuclein as well as oxidative and nitrosative stress contribute to α-synuclein pathology, in part, via enhanced oligomerization, fibrillation and aggregation. During the last funding cycle, we showed in collaboration with Project 1 that activation of the non- receptor tyrosine kinase, c-Abl may contributes to the pathogenesis of PD. From these studies emerged the exciting preliminary findings that c-Abl phosphorylates α-synuclein at tyrosine 39. However, the potential roles of tyrosine 39 α-synuclein and c-Abl activation in pathogenesis of PD has not been explored. We will study the roles of phosphorylation of α-synuclein at tyrosine 39 and c-Abl activation in the death of DA neurons due to α- synuclein, as well as, their roles in aggregation of α-synuclein in vitro and in vivo. With the Proteomics Core D, the Clinical Core B and the Neuropathology Core C, we will investigate whether the levels of phosphorylation of α-synuclein at tyrosine 39 can serve as a progression and/or pathologic maker of α-synuclein-induced neurodegeneration and of α-synuclein pathology in human PD. For these studies, we will assess the levels of tyrosine 39 phosphorylation of α-synuclein and the activation state of c-Abl in human A53T α-synuclein transgenic model, the adeno-associated virus-WT or A53T α-synuclein model with DA neuron loss, and human post-mortem tissues from PD patients via a phosphospecific tyrosine 39 α-synuclein antibody and MRM (Multiple Reaction Monitoring) mass spectrometry. Cell-to-cell transmission of misfolded α-synuclein may contribute to the degeneration of DA neurons in sporadic PD and the mechanisms accounting for the recruitment and the corruption of endogenous α-synuclein into fibrils are not known. Since our preliminary data suggests that tyrosine 39 phosphorylation of α-synuclein by c-Abl promotes the fibrillation of α-synuclein, we will study the ability of WT versus phospho-deficient Y39F and phospho-mimetic α-synuclein Y39E, as well as c-Abl deficiency in cell-to-cell transmission and degeneration of DA neurons in the α-synuclein PFF model of sporadic PD. Finally, we will explore proteomic changes induced by α-synuclein PFFs in degenerating DA neurons via advanced spike-in mass spectrometry approaches combined with SILAM (Stable Isotope Labeling in Mammals). These studies will provide new mechanistic insights into the pathogenesis of α-synuclein induced neurodegeneration and may lead to the development of novel therapeutic targets and biomarkers for the treatment of PD.