Project 2: Drosophila model of Parkinson-like neurodegeneration as a tool

PINK1基因突变与常染色体隐性遗传性早发性家族性黄斑变性有关 帕金森氏病(PD)。PINK1的分子和生理功能 PD相关的PINK1突变体的病理异常在很大程度上是未知的。因此，我们有 建立果蝇帕金森病遗传模型，研究果蝇帕金森病在体内的作用及遗传交互作用。 PINK1，已知的和新的潜在致病因素。我们最近已经证明， 利用RNAi灭活果蝇PINK1(DPINKI)导致多巴胺能(DA)进行性丧失 神经元和复眼的小眼退行性变，这是通过表达 人类PINK1(HPINKI)。此外，人超氧化物歧化酶1(SOD1)的表达抑制了 DPINKI失活诱导的神经变性及其对dPINKI RNAi果蝇的治疗作用 抗氧化剂(如维生素E)显著抑制眼小眼退化。因此，PINK1通常可以 防止神经元经历氧化应激，这是一种潜在的机制，通过减少 PINK1功能导致帕金森病相关神经退行性变。因此，在这个提议中，我们假设 PINK1通过调节通路在维持多巴胺能神经元存活中起关键作用 涉及对氧化应激的保护。帕金森病致病PINK1突变体损害功能 因此失去了保护神经元免受氧化应激的能力。在这项研究中，我们将 利用我们新开发的PD Fly模型(发表在PNAS上)，首先研究 影响帕金森病致病表型严重程度的遗传机制和相互作用 由PINK1突变在不同的(氧化)应激条件下产生。事实上，野性类型 人类PINK1而不是疾病相关的PINK1突变可以逆转帕金森病相关的病理 我们的苍蝇模型为我们提供了在整个动物系统中有效筛选基因的机会 以及可能与寻找这种疾病的治疗方法相关的化学修饰剂。我们建议 筛选新的遗传因素以及可以改变(例如，改善或 加重)在我们的PD果蝇模型中观察到的神经退行性表型。

Mutations in the PINK1 gene are linked to an autosomal recessive early onset familial form of Parkinson's disease (PD). The molecular and physiological functions of PINK1 that generate pathological abnormality of PD-associated PINK1 mutants are largely unknown. .Therefore, we have developed a genetic model of PD in Drosophila to study the in vivo role and genetic interactions of PINK1 with known and new potential contributors to this disease. We have recently shown that inactivation of Drosophila PINK1 (dPINKI) using RNAi results in progressive loss of dopaminergic (DA) neurons and in ommatidial degeneration of the compound eye, which is rescued by expression of human PINK1 (hPINKI). Moreover, expression of human superoxide dismutase 1 (SOD1) suppresses neurodegeneration induced by dPINKI inactivation, and treatment of dPINKI RNAi flies with antioxidants (e.g., vitamin E) significantly inhibits ommatidial degeneration. Thus, PINK1 may normally prevent neurons from undergoing oxidative stress, a potential mechanism by which a reduction in PINK1 function leads to PD-associated neurodegeneration. Therefore, in this proposal we hypothesize that PINK1 plays a critical role in maintaining survival of dopaminergic neurons via a regulated pathway involving protection against oxidative stress. PD-pathogenic PINK1 mutants impair the functional pathway and therefore lose the ability to protect neurons from oxidative stress. In this study, we will take advantage of our newly-developed PD fly model (published in PNAS) to first investigate the genetic mechanisms and interactions that influence the severity of the PD pathogenic phenotype produced by PINK1 mutations under different (oxidative) stress conditions. The fact that wild-type human PINK1 but not disease-associated PINK1 mutations can reverse PD-associated pathologies in our fly model provides us with the opportunity to efficiently screen in a whole animal system for genetic and chemical modifiers that are likely relevant to finding therapeutics for this disease. We propose to screen for new genetic factors as well as for chemical compounds that can alter (e.g., ameliorate or aggravate) the neurodegenerative phenotype observed in our PD fly model.