Aging, Amyloidosis and levels of Transthyretin Oxidative Carbonylation

衰老、淀粉样变性和运甲状腺素蛋白氧化羰基化水平

• 批准号: 9144297
• 负责人: Natalia Reixach
• 金额: $ 9.63万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2016-10-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9144297
• 关键词: Address; Age; Aging; Aging-Related Process; Alzheimer' s Disease; Amyloid; Amyloid Fibrils; Amyloidosis; Antioxidants; Biological; Biopsy; Cardiac; Cerebrospinal Fluid; Cessation of life; Clinical Trials; Data; Deposition; Development; Diagnosis; Disease; Enzyme-Linked Immunosorbent Assay; Experimental Designs; Foundations; Functional disorder; Genetic; Goals; Health; Histologic; Human; In Vitro; Individual; Methods; Modification; Neurodegenerative Disorders; Onset of illness; Organ; Parkinson Disease; Patients; Plasma; Play; Post-Translational Protein Processing; Prealbumin; Proteins; Protocols documentation; Recombinants; Reporting; Risk Factors; Role; Sampling; Site; Structure; Syndrome; Testing; Therapeutic Intervention; Tissues; Transgenic Animals; Transgenic Mice; Western Blotting; Work; age related; aged; amyloid formation; antioxidant therapy; base; disease diagnosis; extracellular; in vivo; mouse model; mutant; novel therapeutic intervention; novel therapeutics; oxidation; premature; prevent; protein aggregation; protein misfolding

DESCRIPTION (provided by applicant): The transthyretin amyloidoses are fatal protein misfolding disorders characterized by the extracellular deposition of aggregates and amyloid fibrils derived from the plasma homotetrameric protein transthyretin (TTR). Aging is a major risk factor for both the senile (wild-type) and genetic (mutant TTR) forms of these disorders. It is not known which aspects of the aging process contribute to the onset of the TTR amyloidoses. Protein carbonylation is an oxidative modification common of old age and it is associated with age-related neurodegenerative illnesses such as Alzheimer's and Parkinson's diseases. We previously established in vitro that recombinant carbonylated TTR (car-TTR) is less stable and has higher propensity to aggregate than non-oxidized TTR. We also demonstrated that the only therapy currently under clinical trials based on TTR tetramer stabilization is significantly less efficient for car-TTR than for non-oxidized TTR. The implications of these studies are that if car-TTR levels increase with age, they will promote the onset of the amyloidoses; moreover, tetramer stabilization therapy may not be sufficient to treat these disorders. Although car-TTR has been detected in plasma of healthy individuals, no systematic studies exist with respect to its changing abundance with age or with the presence of TTR amyloidoses. Our working hypotheses are: 1) Car-TTR content in plasma increases with age; 2) Car-TTR content in plasma is higher in TTR amyloid patients than in healthy controls. Our goals are to establish whether an increase in car-TTR in plasma is associated with age and/or with overt TTR amyloidoses. To accomplish these goals we will exploit our already established methods to quantify total TTR in plasma and optimize our working protocols to specifically quantify car-TTR in the same samples. The experimental design includes the following groups: i) Healthy humans aged 20 to 72 years; ii) Patients with TTR amyloidosis and age-matched healthy controls; iii) Healthy young and old transgenic mice over-expressing human wild-type TTR; iv) Transgenic mice over-expressing human wild-type TTR, with and without histologically confirmed TTR deposition. Finding a correlation between car-TTR content with age and/or the positive diagnosis of TTR amyloidosis, together with the already established fact that car-TTR is more prone to aggregation than non-oxidized TTR, will indicate that this type of age-related oxidative modification may play a role in the onset of the TTR aggregation disorders. It will also open a new therapeutic approach to prevent disease onset consisting in anti-oxidant therapy to preclude car-TTR formation. We will formally test the causal hypothesis, i.e. car-TTR formation is involved in the onset of the TTR amyloidoses, and the novel therapeutic strategy in vivo in a forthcoming R01 proposal. Finally, the results of our studies can have direct implications to the understanding of the initiation of other age-related diseases of protein aggregation where the precursor amyloidogenic proteins might be susceptible to the same type of oxidative modifications.

描述（由申请人提供）：运甲状腺素蛋白淀粉样变性是致命的蛋白质错误折叠病症，其特征在于来自血浆同源四聚体蛋白运甲状腺素蛋白（TTR）的聚集体和淀粉样原纤维的细胞外沉积。衰老是这些疾病的老年型（野生型）和遗传型（突变型 TTR）的主要危险因素。它不是 已知衰老过程的哪些方面会导致 TTR 淀粉样变性的发生。 蛋白质羰基化是老年常见的氧化修饰，与年龄相关的神经退行性疾病（例如阿尔茨海默病和帕金森病）有关。我们之前在体外证实重组羰基化 TTR (car-TTR) 比非氧化 TTR 稳定性较差，并且具有更高的聚集倾向。我们还证明，目前正在进行临床试验的唯一基于 TTR 四聚体稳定的疗法对于 car-TTR 的效率明显低于非氧化 TTR。这些研究的意义在于，如果 car-TTR 水平随着年龄的增长而增加，它们将促进淀粉样变性的发生；此外，四聚体稳定疗法可能不足以治疗这些疾病。尽管已在健康个体的血浆中检测到 car-TTR，但尚无关于其丰度随年龄或 TTR 淀粉样变性的存在而变化的系统研究。我们的工作假设是：1）血浆中的Car-TTR含量随着年龄的增长而增加； 2）TTR淀粉样蛋白患者血浆中Car-TTR含量高于健康对照者。我们的目标是确定血浆中 car-TTR 的增加是否与年龄和/或明显的 TTR 淀粉样变性有关。为了实现这些目标，我们将利用我们已经建立的方法来量化血浆中的总 TTR，并优化我们的工作方案以专门量化相同样本中的 car-TTR。实验设计包括以下几组： i) 20 至 72 岁的健康人； ii) TTR 淀粉样变性患者和年龄匹配的健康对照； iii) 过表达人类野生型TTR的健康年轻和年老转基因小鼠； iv) 过度表达人类野生型 TTR 的转基因小鼠，有或没有组织学证实的 TTR 沉积。 发现 car-TTR 含量与年龄和/或 TTR 淀粉样变性阳性诊断之间的相关性，以及已经确定的 car-TTR 比非氧化 TTR 更容易聚集的事实，将表明这种类型的与年龄相关的氧化修饰可能在 TTR 聚集障碍的发生中发挥作用。它还将开辟一种新的治疗方法来预防疾病发作，包括抗氧化治疗以阻止 car-TTR 的形成。我们将在即将推出的 R01 提案中正式测试因果假设，即 car-TTR 的形成与 TTR 淀粉样变性的发生有关，以及新的体内治疗策略。最后，我们的研究结果可以对理解其他与年龄相关的蛋白质聚集疾病的发生产生直接影响，其中前体淀粉样蛋白可能容易受到相同类型的氧化修饰的影响。