Superoxide Dismutase, Peroxynitrite and ALS

超氧化物歧化酶、过氧亚硝酸盐和 ALS

• 批准号: 7848812
• 负责人: JOSEPH S BECKMAN
• 金额: $ 31.66万
• 依托单位: OREGON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7848812
• 关键词: Accounting; Active Sites; Address; Affect; Agreement; American; Amyotrophic Lateral Sclerosis; Animals; Antioxidants; Autopsy; Binding; Binding Sites; Brain; Copper; Cu-Superoxide Dismutase; Cuprozinc Superoxide Dismutase; Data; Development; Disease; Disulfides; Dorsal; Environmental Health; Enzymes; Familial Amyotrophic Lateral Sclerosis; Fourier transform ion cyclotron resonance; Free Radicals; Heart; Horns; Human; In Vitro; Lead; Ligand Binding; Link; Maps; Mass Spectrum Analysis; Measurable; Measures; Metals; Methods; Molecular; Molecular Chaperones; Motor Neuron Disease; Motor Neurons; Mus; Mutation; Nitric Oxide; Oxidation-Reduction; Paralysed; Patients; Peroxonitrite; Predisposition; Process; Proteins; Rattus; Role; Site; Spatial Distribution; Spinal; Spinal Cord; Staging; Superoxide Dismutase; Superoxides; Testing; Toxic effect; Transgenic Animals; Transgenic Mice; Transgenic Organisms; Tyrosine; Zinc; Zinc deficiency; base; copper zinc superoxide dismutase; dimer; disulfide bond; gain of function; in vivo; innovation; killings; mutant; nitration; overexpression; protein aggregation; public health relevance; research study; theories; tool

DESCRIPTION (provided by applicant): Description ALS is a fatal progressive paralysis affecting 34,000 Americans and killing 8,000 per year. The discovery in 1993 of dominant mutations to Cu,Zn-superoxide dismutase (Cu,Zn-SOD) linked to 2-7% of ALS cases led to hopes that new treatments for ALS based on antioxidants might be forthcoming. Whereas there is broad agreement that ALS mutant SODs have impaired stability, the specific toxic gain-of-function associated with these mutations is still hotly debated. The two leading explanations are the aggregation hypothesis that aggregation of mutant SODs is a direct cause of disease and the zinc-deficient hypothesis that disease is due to increased redox activity of SOD that has lost zinc but retains copper in its active site. We propose, based on extensive preliminary evidence, that the two hypotheses are intimately interconnected with aggregation being paradoxically protective by removing zinc-deficient SOD. The zinc-deficient hypothesis also raises the intriguing possibility that SOD could contribute to sporadic ALS. We have developed innovative mass spectrometric methods to quantitively the metal content of SOD across the spinal cord, which allow us to critically evaluate the zinc-deficient and aggregation hypotheses. Aim 1 will characterize how the dimer interface and the intramolecular disulfide of SOD are affected by ALS-associated mutations to affect zinc and copper binding as well as propensity for aggregation of SOD. This aim will explore the physical basis underlying metal loss and aggregation to understand how mutant SODs are more prone to losing zinc and why mutant SODs are dominant in inheritance. Aim 2 will assess how the concentrations of zinc-deficient SOD are modulated by CCS (the copper chaperone for SOD) and wild-type Cu,Zn SOD in transgenic animals both of which accelerate disease in vivo -- and how to most effectively pharmacologically decrease zinc-deficient SOD in vivo. Aim 3 will map the anatomical distribution of the different metal states of SOD in disease-affected versus unaffected regions in human sporadic ALS patients, testing whether zinc-deficient SOD may be the common connection between sporadic and familial SOD. New preliminary data demonstrate a vast improvement in sensitivity with the FTICR that makes Aim 3 feasible. Completion of the proposed experiments will critically test how SOD mutations lead to the development of ALS and whether loss of zinc occurs from wild-type SOD in sporadic ALS. PUBLIC HEALTH RELEVANCE: Only a small percentage of patients with Lou Gehrig's disease (also known as ALS) carry mutations to a common antioxidant defense enzyme called SOD. Completion of the proposed experiments will help explain how SOD can be involved in the vast majority of sporadic ALS patients who do not have SOD mutations, which will point to new ways to treat the disease. We specifically are testing the hypothesis that this enzyme becomes toxic when it loses one zinc atom and have developed new mass spectrometric methods that directly measure the loss of zinc directly from the spinal cord.

描述（由申请人提供）：描述ALS是一场致命的进行性瘫痪，影响了34,000名美国人，每年杀死8,000人。 1993年发现对CU的主要突变的发现，Zn-羟氧化物歧化酶（CU，Zn-SOD）与2-7％的ALS病例有关，希望可能即将出现基于抗氧化剂的ALS的新治疗方法。尽管有广泛的同意ALS突变SOD稳定性受损，但与这些突变相关的特定毒性功能仍然存在激烈的争论。两个主要的解释是聚集假设，即突变SOD的聚集是疾病的直接原因，并且缺乏锌的假设是，疾病是由于SOD的氧化还原活性增加而导致的，但在其活性部位保留了铜。我们提出，基于广泛的初步证据，即这两个假设与消除锌缺陷的SOD通过矛盾保护性的聚集密切相互联系。缺乏锌的假设也提高了SOD可能有助于零星ALS的有趣可能性。我们已经开发了创新的质谱方法，以定量地对脊髓进行SOD的金属含量，从而使我们能够严格评估缺乏锌和聚集的假设。 AIM 1将表征SOD的二聚体界面和分子内二硫化物如何受ALS相关突变的影响，以影响锌和铜的结合以及SOD聚集的倾向。这个目标将探索物理基础金属损失和聚集，以了解突变类草皮更容易失去锌，以及为什么突变类草皮在继承中占主导地位。 AIM 2将评估如何通过CCS（SOD的铜伴侣）和野生型Cu（转基因动物中的Zn SOD）调节锌缺陷的SOD的浓度，它们在体内加速了疾病 - 以及如何最有效地在体内降低药理学降低锌缺乏的SOD In Vivo。 AIM 3将在人类零星ALS患者的受疾病影响和未受影响的区域中绘制SOD的不同金属状态的解剖分布，测试缺乏锌的SOD是否可能是零星和家族性SOD之间的共同联系。新的初步数据表明，对AIM 3可行的FTICR的敏感性有了极大的改善。提出的实验的完成将严格测试SOD突变如何导致ALS的发展，以及锌的丧失是否来自零星ALS中的野生型SOD。公共卫生相关性：只有一小部分患有Lou Gehrig病的患者（也称为ALS）将突变带到一种称为SOD的常见抗氧化防御酶。拟议的实验的完成将有助于解释SOD如何参与没有SOD突变的绝大多数零星ALS患者，这将指出治疗该疾病的新方法。我们特别检验了以下假设：当该酶失去一个锌原子并开发出新的质谱方法时，该酶会变得有毒，该方法直接直接从脊髓中直接测量锌的损失。