Genetic Dissection of Age-dependent Neuroprotection Mechanisms in Drosophila

果蝇年龄依赖性神经保护机制的遗传解析

基本信息

批准号：
7633620
负责人：
BARRY S GANETZKY
金额：
$ 37.3万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-15 至 2014-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7633620
关键词：
Adolescence Advanced Glycosylation End Products Affect Autophagocytosis Biochemical Biological Biological Assay Brain Cells Cessation of life Chimeric Proteins Collection Coma Communication Defect Dihydroxyacetone Phosphate Dissection Drosophila genus Enzymes Event Exhibits Experimental Models Functional disorder Gene Proteins Generations Genes Genetic Genetic screening method Glyceraldehyde 3-Phosphate Glycolysis Goals Health Histological Techniques Human Isomerase Link Longevity Lysosomes Maintenance Maleimides Maps Mediating Medical Membrane Fusion Molecular Molecular Analysis Molecular Genetics Motor Mutation Nerve Degeneration Neurodegenerative Disorders Neurons Oxidative Stress Paralysed Pathway interactions Phenotype Process Proteins Pyruvaldehyde Recycling Role Signal Transduction Surveys Synaptic Transmission Synaptic Vesicles System Testing Toxic effect Triose-Phosphate Isomerase age related base biological adaptation to stress crosslink dopaminergic neuron dosage fly in vivo mutant nervous system disorder neuromechanism neuron loss neuronal survival neuroprotection novel overexpression prevent progressive neurodegeneration protein complex relating to nervous system research study synuclein wasting

项目摘要

DESCRIPTION (provided by applicant): Our long-term aim is to elucidate molecular mechanisms of neural signaling in Drosophila. Here we focus on analysis of mutants with defects in maintenance of neuronal viability. We have discovered several mutations among our collection, including wstd and comt, that exhibit shortened lifespan and age-dependent, progressive neurodegeneration providing us with novel starting points to dissect neuroprotective mechanisms. Our goals are to determine the in vivo roles of the affected proteins using genetic, molecular, biochemical, and histological techniques to analyze how defects in these proteins result in the observed phenotypes. wstd encodes the glycolytic enzyme, triose phosphate isomerase (Tpi) responsible for the interconversion of DHAP (dihydroxyacetone phosphate) and GAP (glyceraldehyde 3-phosphate), only the latter of which is able to continue through glycolysis. Mutations of Tpi in humans result in Triosephosphate isomerase deficiency, characterized by early death and neurodegeneration but the underlying mechanism has remained unclear. We hypothesize that the enzymatic block in Tpi-deficient flies and humans leads to excess accumulation of methylglyoxal (MG), which reacts with target proteins to generate advanced glycation end products (AGEs) causing loss of protein activity, cross-linking, aggregation, and ultimately neuronal death. We propose genetic and biochemical experiments to test and refine this hypothesis. comt, which encodes NSF-1 (N-ethyl- maleimide sensitive fusion protein), exhibits a deficit in lysosomes and accumulation of ubiquitinated protein complexes in parallel with neurodegeneration. We hypothesize that comt is deficient in autophagy. Experiments are proposed to test this hypothesis and to dissect the step(s) in the process that are impaired. Additional mechanisms of neuroprotection will be investigated by phenotypic and molecular analysis of other mutants in our collection that exhibit neurodegeneration. Neuroprotective mechanisms are essential for proper neural communication and their disruption leads to some of the most devastating human neurological disorders. Detailed understanding of these mechanisms is thus of fundamental biological as well as medical importance. Drosophila has already proven to be a potent experimental system for elucidating these mechanisms. Moreover, both wstd and comt have direct links with human neurodegenerative disorders. Consequently, our proposed analyses should have broad biological and medical significance by contributing important new information that will advance our understanding of the underlying molecules and mechanisms that maintain neuronal viability and integrity.

描述（由申请人提供）：我们的长期目的是阐明果蝇中神经信号传导的分子机制。在这里，我们专注于分析神经元生存力缺陷的突变体。我们在包括WSTD和COMT在内的收集中发现了一些突变，这些突变表现出缩短的寿命和年龄依赖性的，进行性神经变性，从而为我们提供了新的起点，以剖析神经保护机制。我们的目标是使用遗传，分子，生化和组织学技术来确定受影响蛋白的体内作用，以分析这些蛋白质中的缺陷如何导致观察到的表型。 WSTD编码负责DHAP（二羟基乙酮磷酸）和GAP（3-磷酸甘油醛）的互转换的糖酵解酶，三糖异构酶（TPI），只有后来能够通过糖酶溶液进行。人类中TPI的突变导致三尿磷酸异构酶缺乏症，其特征是早期死亡和神经退行性，但潜在的机制尚不清楚。我们假设TPI缺陷蝇和人类的酶促阻滞导致甲基糖（MG）的过量积累，这与靶蛋白反应以产生晚期糖基化终产物（AGES），从而导致蛋白质活性丧失，交叉链接，聚集以及最终神经元死亡。我们提出了遗传和生化实验，以检验和完善这一假设。 COMT编码NSF-1（N-乙基马来酰亚胺敏感的融合蛋白），表现出与神经变性并行的泛素化蛋白复合物的溶酶体和泛素化蛋白复合物的积累。我们假设COMT缺乏自噬。提出了实验来检验这一假设，并剖析了受损过程中的步骤。神经保护的其他机制将通过表型和分子分析在我们的集合中表现出神经变性的其他突变体进行研究。神经保护机制对于适当的神经传播至关重要，它们的破坏导致了一些最具破坏性的人类神经系统疾病。因此，对这些机制的详细理解是基本的生物学和医学重要性。果蝇已经被证明是阐明这些机制的有效实验系统。此外，WSTD和COMT都与人类神经退行性疾病有直接联系。因此，我们提出的分析应通过贡献重要的新信息来具有广泛的生物学和医学意义，以提高我们对维持神经元生存能力和完整性的基本分子和机制的理解。