Modulation of ATP synthesis in mitochondrial disorders

描述(由申请人提供)： 作为一名受过临床神经学和基础科学培训的研究人员，主要对线粒体疾病领域感兴趣，我的主要科学目标是更好地了解这类疾病的致病机制，并确定治疗它们的策略。我的主要科学生涯目标是在线粒体疾病领域做出新的重要贡献，并满足成为一家著名学术机构的终身教员的要求。我相信威尔医学院的神经病学和神经科学系是开展我的工作和实现我的职业目标的理想环境，因为它为科学发展提供了肥沃的土壤，允许与包括康奈尔大学、纪念斯隆·凯特琳和洛克菲勒大学在内的三所机构中的顶尖科学家进行互动。这项提议的范围是双重的。首先，调节线粒体ATP合成在由线粒体DNA编码的ATPase 6(A6)突变引起的综合征NARP(神经病性共济失调和视网膜色素变性)中的作用。第二，建立重现NARP特征的细胞和动物模型。这样的模型将有助于在体内研究线粒体疾病的致病机制，并测试治疗方法。 目的1：NARP细胞产生更多的自由基。线粒体呼吸链存在缺陷，可能是由于损伤或抑制，抗氧化剂可以改善NARP胞质细胞的ATP合成。我们将确定呼吸链功能障碍的机制，并测试抗氧化剂对直接来自NARP患者的细胞的影响。 目的：在NARP模型中，核内异位表达野生型A6蛋白可促进线粒体ATP合成。我们的目标是评估A6的异位表达是否会改善患者来源细胞的ATP合成，以及这种方法是否具有治疗用途。 目的3：目前尚无NARP的动物模型。外源mtDNA不能转移到线粒体以产生NARP的转基因模型。我们将测试两种替代策略来产生概括NARP生化和临床缺陷的突变：a)通过针对正常线粒体的突变A6的核异位表达；b)通过在与A6相互作用的关键位置引入核编码的线粒体蛋白ATPase亚单位C的突变。

DESCRIPTION (provided by applicant): As a researcher trained in clinical neurology and basic science with a primary interests in the field of mitochondrial disorders, my principal scientific goal is to better understand the pathogenic mechanisms of this group of diseases and to identify strategies to treat them. My main scientific career goals are to make novel and important contributions to the field of mitochondrial disorders and to satisfy the requirements to become a tenured faculty member in a prestigious academic institution. I believe that the Department of Neurology and Neuroscience at the Weill medical College is an ideal environment to conduct my work and to fulfill my career goals because it provides a fertile ground for scientific growth by allowing interactions with topnotch scientists within the tri-institutional organization that includes Cornell University, Memorial Sloan Kettering, and Rockefeller University. The scope of this proposal is twofold. First, to modulate mitochondrial ATP synthesis in the syndrome NARP (neuropathy ataxia and retinitis pigmentosa) caused by mutations in the mtDNA encoded ATPase 6 (A6). Second, to develop cellular and animal models recapitulating the features of NARP. Such models will serve to investigate in vivo the pathogenic mechanisms underlying mitochondrial disorders and to test therapeutic approaches. Aim 1: NARP cells generate increased free radicals. The mitochondrial respiratory chain is defective presumably due to damage or inhibition and ATP synthesis in NARP cybrid cells can be improved by antioxidants. We will define the mechanisms underlying the respiratory chain dysfunction and test the effects of antioxidants in cells directly derived from NARP patients. Aim 2: We showed that the expression of a wild type A6 protein allotopically from the nucleus improved mitochondrial ATP synthesis in a cybrid model of NARP. The goal is to assess whether allotopic expression of A6 will improve ATP synthesis in patient-derived cells and whether this approach can have a therapeutic use. Aim 3: There are no animal models of NARP. Exogenous mtDNA cannot be transferred into mitochondria to generate transgenic models of NARP. We will test two alternative strategies to generate mutants that recapitulate the biochemical and clinical defects of NARP: a) By allotopic expression from the nucleus of a mutant A6 targeted to normal mitochondria; b) By introducing mutations in a nuclear-encoded mitochondrial protein, ATPase subunit C, at crucial sites of interaction with A6.