New Drosophila Model of VPS35 Parkinsonism

描述（由申请人提供）：对帕金森病（PD）的更好治疗的需求不断增长。我们的目标是提高对参与这种神经退行性过程发病机制的分子途径的理解，最终为疾病改善治疗干预找到新的药理学靶点。液泡蛋白分类35 （VPS35）作为PD最新常染色体显性致病基因的鉴定突出了反转录物和反转录物依赖性转运在PD中的作用。然而VPS35究竟如何参与PD的发病机制尚不清楚，目前还没有VPS35帕金森病的动物模型。因此，这项拨款申请的目标是开发第一个VPS35帕金森病的动物模型。具体来说，我们正在计划产生一种新的转基因果蝇系，它将允许表达果蝇Vps35的D647N突变（相当于PD患者中发现的致病性D620N突变）。我们预计，在多巴胺能神经元中表达Vps35（D647N）将导致神经元死亡、运动缺陷、对鱼藤酮的敏感性增加和自噬受损——这一细胞过程最近与包括帕金森病在内的几种神经退行性疾病的发病机制有关。具体来说，我们假设Vps35是有效自噬所必需的，表达Vps35（D647N）会损害自噬反应。此外，我们假设Vps35（D647N）突变果蝇将呈现眼睛表型，类似于许多其他神经退行性疾病模型，包括我们的LRRK2转基因果蝇。眼睛表型的表征将使这种动物模型在未来的遗传筛选或药物筛选中具有价值。这将为研究PD的体内发病机制提供新的有价值的工具，有助于阐明这一新发现的逆转录依赖通路对PD病理的作用机制。这可能会显著推动PD和其他神经退行性疾病领域的发展，并可能为更好的治疗发现新的药理靶点。

DESCRIPTION (provided by applicant): There is a growing unmet need for a better treatment of Parkinson's disease (PD). Our goal is to improve the understanding of molecular pathways involved in the pathogenesis of this neurodegenerative process, to ultimately find new pharmacological targets for a disease-modifying therapeutic intervention. Identification of Vacuolar protein sorting 35 (VPS35) as the latest autosomal dominant causative gene of PD highlighted the role of retromer and retromer-dependent trafficking in PD. However how exactly VPS35 contributes to PD pathogenesis is entirely unknown, and at present there is no animal model of VPS35 parkinsonism. Therefore the goal of this grant application is to develop the first animal model of VPS35 parkinsonism. Specifically, we are planning to generate a new transgenic Drosophila line that will allow expressing the D647N mutant of Drosophila Vps35 (equivalent to the pathogenic D620N mutation identified in PD patients). We anticipate that expressing Vps35(D647N) in dopaminergic neurons will lead to neuronal death, locomotor deficits, increased sensitivity to rotenone, and impaired autophagy - a cellular process recently implicated in the pathogenesis of several neurodegenerative disorders, including PD. Specifically, we postulate that Vps35 is required for efficient autophagy, and that expressing Vps35(D647N) will impair the autophagic response. In addition, we hypothesize that Vps35(D647N) mutant flies will present with an eye phenotype, similar to many other models of neurodegenerative disorders, including our LRRK2 transgenic fly. Characterization of an eye phenotype would make this animal model valuable in future genetic screens or drug screens. This proposal will provide a new valuable tool to study PD pathogenesis in vivo, one that will help elucidate the mechanisms by which this newly discovered retromer-dependent pathway contributes to PD pathology. This may significantly advance the field of PD and other neurodegenerative disorders, and may uncover new pharmacological targets for a better treatment.