IDENTIFICATION OF FLUORESCENT LIGANDS FOR ALPHA SYNUCLEIN FIBRILS

摘要 帕金森病(PD)的定义是神经元中α-突触核蛋白(ASYN)纤维的积聚 细胞质和神经元包涵体称为路易小体和路易突起。Asyn在其中的作用 Asyn(SNCA)编码基因的显性突变支持其发病机制。 罕见的家族性帕金森病。帕金森病的进展，特别是帕金森病患者痴呆的发展，与 随着Asyn在整个大脑中更广泛的沉积，包括新皮质。多重治疗 正在寻求针对异步者积累的方法。当务之急是开发一种PET成像 可以量化Asyn在活着的个体中的沉积作为靶向参与的生物标志物的试剂 临床研究。Asyn PET显像剂也将提高PD诊断的准确性，并提供 疾病进展的生物标记物。我们开发了一种新的筛选方法来鉴定新的化合物 这可以作为开发ASYN显像剂的线索。这种新方法使用 荧光测量以确定商业图书馆中天然荧光化合物的子集。我们 然后使用荧光测量来筛选天然的荧光化合物以在体外结合Asyn纤维 然后评估化合物是否与死后帕金森病脑内含Asyn的路易小体结合 组织切片。最后一步是确定化合物是否选择性地与路易体结合，但不结合。 尸检脑组织切片中的淀粉样斑块或神经原纤维缠结。该项目将使用此 筛选5000种荧光化合物的方法。被发现具有所需性质的化合物将被 用氚进行放射性标记，以便利用放射性配基结合进一步表征其结合性质 化验和放射自显影。该项目中确定的化合物可以作为进一步研究的线索 开发一种ASYN显像剂。该项目的结果还将使这一新的 一种筛选方法，用于鉴定具有显像剂所需结合特性的化合物。

Abstract Parkinson's Disease (PD) is defined by the accumulation of alpha-synuclein (Asyn) fibrils in neuronal cytoplasmic and neuritic inclusions known as Lewy bodies and Lewy neurites. The role of Asyn in pathogenesis is supported by the identification of dominant mutations in the gene encoding Asyn (SNCA) in rare familial versions of PD. PD progression, particularly the development of dementia in PD, is associated with more widespread deposition of Asyn throughout the brain, including neocortex. Multiple therapeutic approaches targeting Asyn accumulation are being pursued. A leading priority is to develop a PET imaging agent that can quantify the deposition of Asyn in living individuals, as a biomarker for target engagement in clinical studies. An Asyn PET imaging agent would also improve the accuracy of diagnosis for PD, and provide a biomarker for disease progression. We developed a new screening approach to identify novel compounds that can be pursued as leads for the development of an Asyn imaging agent. This new approach uses fluorescence measurements to identify a subset of natively fluorescent compounds in a commercial library. We then use fluorescence measurements to screen natively fluorescent compounds for binding Asyn fibrils in vitro followed by assessment of whether compounds bind to Asyn-containing Lewy bodies in postmortem PD brain tissue sections. A final step is to determine whether compounds selectively bind to Lewy bodies but do not bind to amyloid plaques or neurofibrillary tangles in postmortem brain tissue sections. The project will use this approach to screen 5000 fluorescent compounds. Compounds found to have the desired properties will be radiolabeled with tritium in order to further characterize their binding properties using radioligand binding assays and autoradiography. The compounds identified in the project can be used as leads in further studies to develop an Asyn imaging agent. Results from the project will also enable further optimization of this new screening approach to identify compounds with the binding properties needed for an imaging agent.