INTERACTIONS BETWEEN ALPHA-SYNUCLEIN/METALS/PESTICIDES

描述（摘自研究者摘要） 拟议研究的目标是促进我们对如何 环境因素（如金属和农药）可能与 组成蛋白（即α-突触核蛋白）以及这种相互作用如何 导致帕金森病中蛋白质聚集和神经元变性。 调查员实验室的初步结果表明， α-突触核蛋白的自聚集在存在 铝或杀真菌剂二乙基二硫代氨基甲酸盐（DDC）。 的 这些相互作用的潜在分子基础将在体外进行评价， 为了检验增加的α-突触核蛋白聚集是一种 其构象、缔合性质和 由铝或DDC引起的纤维结构。 的可能性 其它金属和杀虫剂（或试剂的组合）能够 还将测试影响α-突触核蛋白聚集速率的 实验性的 α-突触核蛋白和 然后将在体内动物模型中评估金属和农药，即， 在酪氨酸修饰下过表达人α-突触核蛋白的转基因小鼠 羟化酶启动子 因为这些老鼠表达高水平的α- 突触核蛋白在多巴胺能神经元中的表达，它们提供了一个有价值的模型， 来评估α- 突触核蛋白与环境因子。 第一个要检验的假设是 这些动物暴露于铝或DDC（或其他金属， 农药）诱导α-突触核蛋白的聚集和Lewy 体样包涵体（Lewy小体是淋巴结转移的病理标志之一， 帕金森氏症）。 第二个假设是， 蛋白酶体活性（细胞蛋白质降解的关键途径）在细胞内起着重要的作用。 在金属和农药诱导的路易体样形成中的作用。 解决 根据这一假设，含有α-突触核蛋白的包涵体的出现将 在暴露于金属和杀虫剂的过度表达小鼠中进行监测， 存在蛋白酶体活性抑制剂。 最后一个假设是 α-突触核蛋白的过度表达增加了 黑质纹状体系统对金属和农药的损伤。 小鼠将被 暴露于铝或DDC（或其他金属和农药）和多巴胺能 将比较过表达与非过表达的细胞损伤 动物 这些实验的结果可能会澄清 α-突触核蛋白聚集及其在路易体形成中的作用。 也许最 然而，重要的是，它们将进一步加深我们对 包涵体、多巴胺能变性、金属和杀虫剂之间的联系， 两者都与原发性帕金森病的病因有关 疾病

DESCRIPTION (Taken from the Investigator's Abstract) The goal of the proposed studies is to advance our understanding of how environmental agents (i.e. metals and pesticides) might interact with constitutive proteins (i.e. alpha-synuclein) and how such interactions could lead to protein aggregation and neuronal degeneration in Parkinson's Disease. Preliminary results obtained in the investigator's laboratory indicate that self-aggregation of alpha-synuclein is dramatically enhanced in the presence of either aluminum or the fungicide diethyldithiocarbamate (DDC). The underlying molecular basis of these interactions will be evaluated in vitro in order to test the hypothesis that increased alpha-synuclein aggregation is a consequence of changes in its conformation, association properties and the structure of its fibrils caused by aluminum or DDC. The possibility that other metals and pesticides (or combinations of agents) are capable of affecting the rate of alpha-synuclein aggregation will also be tested experimentally. The consequences of interactions between alpha-synuclein and metals and pesticides will then be evaluated in an in vivo animal model, i.e. transgenic mice overexpressing human alpha-synuclein under the tyrosine hydroxylase promoter. Because these mice express high levels of alpha- synuclein protein within dopaminergic neurons, they provide a valuable model in which to assess the pathologic consequences of interactions of alpha- synuclein with environmental agents. The first hypothesis to be tested in these animals is that exposure to aluminum or DDC (or other metals and pesticides) induces the aggregation of alpha-synuclein and formation of Lewy body-like inclusions (Lewy bodies are one of the pathologic hallmark of Parkinson's Disease). The second hypothesis is that an impairment of proteasome activity (a key pathway of cellular protein degradation) plays a role in metal- and pesticide-induced Lewy body-like formation. To address this hypothesis, the occurrence of alpha-synuclein-containing inclusions will be monitored in overexpressing mice exposed to metals and pesticides in the presence of inhibitors of the proteasome activity. The final hypothesis is that overexpression of alpha-synuclein increases the vulnerability of the nigrostriatal system to injury caused by metals and pesticides. Mice will be exposed to aluminum or DDC (or other metals and pesticides) and dopaminergic cell damage will be compared in overexpressing versus non-overexpressing animal. Results of these experiments are likely to clarify the mechanisms of alpha-synuclein aggregation and its role in Lewy body formation. Perhaps most importantly, however, they will further our understanding of the relationship between inclusion bodies, dopaminergic degeneration and metals and pesticides, both of which have been implicated in the etiology of idiopathic Parkinson's Disease.