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）是由细胞机制失衡引起的，该机制旨在应对神经元的环境压力。PD的两个主要临床特征，称为路易体的蛋白质包涵体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，但这些突变强调了细胞中调节蛋白质折叠和氧化损伤的途径的参与。鉴于散发性PD的优势，毒素的环境来源可能是具有特定遗传易感性的个体的潜在危险因素。一个可能导致PD的环境因素是暴露于某些产生蛋白酶体抑制剂的细菌，如放线菌的特定菌株。在这里，我们建议利用线虫线虫，秀丽隐杆线虫，来机械地研究暴露于与PD有关的细菌菌株。我们的实验室之前已经建立了这种蠕虫模型，用于快速评估影响人类α -突触核蛋白错误折叠和多巴胺神经元神经保护的因素。我们的建议的目的包括研究多巴胺神经元退化是由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基因同源性缺陷动物对细菌暴露的敏感性，以及我们通过大规模RNA干扰（RNAi）筛选获得的新的PD基因靶点。含有荧光报告基因构建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系统影响。基因表达在细菌暴露下的差异变化也将使用全基因组寡核苷酸微阵列来识别对环境毒素响应的潜在基因。与公共卫生相关：遗传易感性与环境损害易感性之间的相互作用是帕金森病的核心。使用严格控制环境条件和遗传差异的系统来评估风险因素是最好的。秀丽隐杆线虫是一种具有8个多巴胺神经元的微观蠕虫，与人类共享约一半的基因，是快速检测可能影响PD发展的环境毒素潜在来源的理想系统。

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.