Modeling PKAN disease through neuron-specific degradation of coenzyme A

通过辅酶 A 的神经元特异性降解模拟 PKAN 疾病

• 批准号: 9035103
• 负责人: Roberta Leonardi
• 金额: $ 22.38万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9035103
• 关键词: 4' -phosphopantetheine; Acyl Coenzyme A; Adult; Affect; Animals; Back; Behavior; Biochemical; Biological Models; Brain; Brain region; Cessation of life; Child; Clinical; Code; Coenzyme A; Cognition; Data; Dependovirus; Development; Diet; Disease; Disease Progression; Embryo; Energy Metabolism; Enzymes; Exhibits; Feedback; Generations; Genes; Genetic; Genetic Recombination; Green Fluorescent Proteins; Human; Impairment; Iron; Knock-out; Lead; Link; Lipids; Longevity; Measurement; Metabolism; Mitochondria; Modeling; Molecular; Morbidity - disease rate; Motor; Motor Skills; Movement; Mus; Mutation; Nerve Degeneration; Neurologic; Neurons; Pantothenate kinase; Pantothenate kinase-associated neurodegeneration; Partner in relationship; Pathology; Pathway interactions; Patients; Phenotype; Play; Protein Isoforms; Reaction; Recycling; Regulation; Research; Role; Site; Spinal Cord; Synapsins; Syndrome; Testing; Therapeutic; Transgenes; Transgenic Mice; Transgenic Organisms; Vision; base; clinically relevant; cofactor; disease-causing mutation; effective therapy; enzyme activity; expectation; high risk; improved; insight; mouse model; nervous system disorder; novel strategies; nudix hydrolase; overexpression; pantothenate; premature; prevent; promoter; public health relevance; therapeutic development; transgene expression

 DESCRIPTION (provided by applicant): Pantothenate kinase-associated neurodegeneration (PKAN) is a relentlessly progressive neurological disorder and the most common syndrome among the neurodegeneration with brain iron accumulation (NBIA) disorders. PKAN patients are at a higher risk for a premature death and exhibit a broad clinical spectrum, with affected children exhibiting a more rapid disease progression and a more severe motor involvement compared to adults. There is no effective treatment for PKAN and the lack of a mouse model of the disease is a major obstacle to the development of a cure. PKAN is caused by mutations in PANK2, a gene that is required for the synthesis of coenzyme A (CoA), a universal cofactor essential for lipid synthesis and energy metabolism. Most of the mutations in PANK2 reduce or abolish the activity of the enzyme, leading to the hypothesis that reduced CoA might be the underlying cause of the neurodegeneration in PKAN patients; however, no mouse model of the disease is currently available to investigate the connection between neuronal CoA levels and neurodegeneration, and the molecular mechanisms leading to PKAN remain unknown. Previous attempts to generate a PKAN mouse model have focused on reducing whole-body CoA synthesis or availability by genetic (knocking out every mouse Pank alone or in combination) and/or dietary manipulations. These approaches have produced mice that either do not show signs of neurodegeneration or cannot be used to develop PKAN therapeutics because of their extremely short life-span (18 days) and/or their significantly impaired whole-body metabolism. We recently made significant progress towards the development of a clinically relevant PKAN mouse model by using a novel approach based on the selective degradation of CoA in mouse neurons. To achieve this, we used the combination of an adeno-associated virus (AAV) and a neuron-specific promoter to deliver and over-express a CoA-degrading enzyme, Nudt7cyt, in neurons throughout the brain and spinal cord. Mice expressing Nudt7cyt exhibited a significant reduction in brain CoA and motor coordination compared to the control mice expressing green fluorescent protein (GFP); however, the highly variable transgene expression obtained with the AAV approach makes the connection between CoA and reduced motor coordination difficult to characterize. The objective of this proposal is to improve this strategy by generating transgenic mice with neuron-specific Nudt7cyt expression. These mice will be evaluated with a combination of behavior, motor skill and histological analyses. The results will be correlated with CoA measurements in different brain regions. This novel approach to the generation of a PKAN mouse model will provide a model system to identify CoA-dependent pathways that are disrupted in PKAN disease and a platform to test potential treatments.

 描述（由适用提供）：泛素激酶相关的神经退行性（PKAN）是一种无情进行性神经系统疾病，是神经变性中最常见的综合症，脑铁累积（NBIA）疾病。 PKAN患者的过早死亡的风险更高，并且表现出广泛的临床范围，与成年人相比，受影响的儿童表现出更快的疾病进展和更严重的运动参与。对PKAN没有有效的治疗方法，缺乏该疾病的小鼠模型是治疗发展的主要障碍。 PKAN是由PANK2突变引起的，Pank2是一种辅酶A（COA）所需的基因，这是脂质合成和能量代谢必不可少的通用辅因子。 PANK2中的大多数突变降低或废除了酶的活性，导致假设降低COA可能是PKAN患者神经变性的根本原因。但是，目前尚无该疾病的小鼠模型来研究神经元COA水平与神经变性之间的联系，并且导致PKAN的分子机制仍然未知。以前的生成PKAN小鼠模型的尝试致力于通过遗传（单独或组合使用每个小鼠）和/或饮食操纵来降低全身COA合成或可用性。这些方法产生了小鼠，因为它们的寿命极短（18天）和/或它们的全身代谢严重损害，因此不能显示神经退行性的迹象或不能用于开发PKAN治疗。最近，我们通过使用基于小鼠神经元中COA的选择性降解的新方法来开发临床相关的PKAN小鼠模型。为了实现这一目标，我们将与腺相关的病毒（AAV）和神经特异性启动子组合在一起，以在整个脑和脊髓的神经元中递送和表达脱发酶NUDT7CYT。与表达绿色荧光蛋白（GFP）的对照小鼠相比，表达NUDT7CYT的小鼠暴露了脑COA和运动配位的显着降低。但是，使用AAV方法获得的高度可变转换表达使COA和降低的运动配位之间的连接难以表征。该提案的目的是通过以神经特异性NUDT7CYT表达产生转基因小鼠来改善该策略。这些小鼠将通过行为，运动技能和组织学分析的结合进行评估。结果将与不同大脑区域的COA测量相关。这种新型PKAN小鼠模型的新方法将提供一个模型系统，以识别COA依赖性途径，这些途径在PKAN疾病中被破坏和测试潜在治疗的平台。