Use of C.elegans to Explore Bacterial Sources of Toxicity in Parkinson's Disease

描述（由申请人提供）：帕金森病（PD）是由旨在科普神经元环境压力的细胞机制失衡引起的。PD的两个主要临床标志，称为Lewy小体的蛋白质内含物和多巴胺神经元变性，是细胞内应激管理失败的代表。虽然遗传形式的PD很少见，但这些突变突出了调节细胞中蛋白质折叠和氧化损伤的途径的参与。鉴于散发性PD占主导地位，环境来源的毒素可能是具有特定遗传倾向的个体的潜在风险因素。可能导致PD的一个环境因素是暴露于产生蛋白酶体抑制剂的某些细菌，例如放线菌目的特定菌株。在这里，我们建议利用线虫，C。elegans，以机械地研究暴露于涉及PD的细菌菌株。我们的实验室先前已经建立了这种蠕虫模型，用于快速评估影响人类α-突触核蛋白的错误折叠和多巴胺神经元的神经保护的因素。我们的建议的目的包括调查多巴胺神经元变性所造成的细菌暴露在野生型蠕虫和遗传定义的背景。我们将评估已知PD基因的蠕虫同源物缺陷动物对细菌暴露的敏感性，以及从我们进行的大规模RNA干扰（RNAi）筛选中获得的新型PD基因靶标。含有荧光报告基因构建体的转基因线虫将用于区分暴露对各种神经元亚型、一般应激反应和蛋白酶体抑制的全身效应。还将使用全基因组寡核苷酸微阵列分析细菌暴露后基因表达的差异变化，以确定响应环境毒素的潜在基因调控。与公共卫生的相关性：遗传易感性和对环境损害的易感性之间的相互作用是PD的核心。风险因素最好使用严格控制环境条件和遗传差异的系统进行评估。C.线虫是一种具有精确8个多巴胺神经元的微小蠕虫，与人类共享大约一半的基因，代表了一种理想的系统，可以快速检查可能影响PD发展的潜在来源环境毒素。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) results from an imbalance in cellular mechanisms designed to cope with environmental stresses to neurons. The two major clinical hallmarks of PD, protein inclusions termed Lewy bodies and dopamine neuron degeneration, are representative of failure in the intracellular management of stress. While genetic forms of PD are rare, these mutations highlight the involvement of pathways that regulate protein folding and oxidative damage in cells. Given the predominance of sporadic PD, environmental sources of toxins may serve as potential risk factors for individuals with specific genetic predispositions. One environmental factor that may contribute to PD is exposure to certain bacteria that produce proteasome inhibitors, such as specific strains of the order Actinomycetales. Here we propose to utilize the nematode roundworm, C. elegans, to mechanistically investigate exposure to bacterial strains implicated in PD. Our lab has previously established this worm model for rapid evaluation of factors influencing both the misfolding of human alpha-synuclein and neuroprotection of dopamine neurons. The aims of our proposal include investigating dopamine neuron degeneration as caused by bacterial exposure in wild-type worms and in genetically defined backgrounds. We will evaluate susceptibility to bacterial exposure in animals defective in worm homologs of known PD genes, in addition to novel PD gene targets obtained from a large-scale RNA interference (RNAi) screen we have performed. Transgenic nematodes containing fluorescent reporter gene constructs will be used to distinguish systemic effects of exposure on various neuronal subtypes, general stress response, and proteasomal inhibition. Differential changes in gene expression in response to bacterial exposure will also be profiled using whole-genome oligonucleotide microarrays to identify potential genes regulated in response to environmental toxins. Relevance to Public Health: The interplay between genetic predisposition and susceptibility to environmental insults lies at the core of PD. Risk factors are best evaluated using systems wherein environmental conditions and genetic differences are strictly controlled. C. elegans, a microscopic worm with precisely 8 dopamine neurons, shares about half of its genes with humans and represents an ideal system to rapidly examine potential sources environmental toxins that may influence development of PD.