Inhibition of Hsp70 ATPase activity reduces tau through the cellular degradation

抑制 Hsp70 ATP 酶活性可通过细胞降解减少 tau 蛋白

• 批准号: 8465154
• 负责人: John Clarence O'Leary
• 金额: $ 1.16万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-14 至 2013-08-16
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8465154
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Accounting; Affect; Alzheimer' s Disease; Amino Acids; Antibodies; Autophagocytosis; Behavioral; Biological Assay; Cell Culture Techniques; Cell model; Cells; Client; Cognition; Complex; Data; Degradation Pathway; Dependovirus; Development; Disease; Exhibits; Frontotemporal Dementia; Future; Genetic; Goals; Hippocampus (Brain); Hydrolysis; Immunohistochemistry; In Vitro; Intervention; Learning; Literature; Measures; Mediating; Memory; Methods; Methylene blue; Modeling; Molecular Chaperones; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Parkinson Disease; Pathway interactions; Pharmaceutical Preparations; Pick Disease of the Brain; Proteins; Regulation; Research; Source; Symptoms; System; Tauopathies; Testing; Therapeutic; Time; Toxic effect; Triage; Western Blotting; aging population; base; brain cell; chaperone machinery; combat; design; high throughput screening; in vivo; inhibitor/antagonist; mouse model; multicatalytic endopeptidase complex; mutant; nervous system disorder; neuron loss; novel strategies; novel therapeutics; overexpression; pleiotropism; prevent; protein degradation; protein misfolding; repaired; research study; tau Proteins; therapeutic target; tool; tool development

Molecular chaperones are a promising therapeutic target in the treatment of neurological diseases of protein misfolding. This is because of their ability to interact with "client" proteins that become misfolded and aggregate-prone. One of these clients, the microtubule associated protein tau, abnormally aggregates in numerous neurodegenerative diseases termed tauopathies. Some chaperone proteins have shown auspicious results as therapeutic targets in models of tauopathy. However, this study proposes to add to the evidence for Hsp70-mediated interventions for the discovery of compounds that reduce tau levels. The chaperone activity of Hsp70 is powered by the hydrolysis of ATP. Moreover, many pharmacological compounds that modulate the rate of ATP hydrolysis of Hsp70 have been shown to modulate the levels of tau: One compound that was shown to inhibit the ATPase activity of Hsp70 is methylene blue (MB). MB has been shown to reduce tau levels in various models of tauopathy and has been shown to rescue cognition. These data suggest that Hsp70 ATPase modulation may be a viable tool for the development of anti-tau therapies. However, there is vast literature describing the many other interactions and effects of MB. As a result, the current data create a stronger case for MB as a promising therapeutic candidate than for Hsp70's ATPase as a therapeutic target. Strong evidence for Hsp70 as a therapeutic target will allow drug developers to create new compounds that may hold the cure for tauopathies. Thus, we have created new genetics-based tools with which to study this question in order to collect data that will either support or refute the hypothesis. We have created single amino acid mutants of Hsp70 and tested their ATPase and refolding activity as well as their effects on tau levels. One mutation, E175S, on Hsp70 reduces its ATPase activity and refolding activity. Furthermore, it reduces tau levels in cell models of tauopathy. Thus, we have replicated the previous in vitro data that used Hsp70 inhibitor compounds. The objective of this study is to test the hypothesis that the inhibition of Hsp70 ATPase activity degrades tau through the cellular degradation pathways. To achieve this, our design consists of the following specific aims: 1) We will block and activate the proteasome, macroautophagy and chaperone-assisted autophagy pathways in the presence of Hsp70E175S overexpression; 2) We will determine if inhibiting the ATPase activity of Hsp70 reduces tau in vivo and evaluate the therapeutic potential of this strategy.

分子伴侣是治疗神经疾病的有前途的治疗靶点 蛋白质错误折叠。这是因为他们能够与“客户”蛋白质互动的能力被错误折叠和 容易发生。这些客户之一，微管相关的蛋白质tau，异常聚集在 许多神经退行性疾病称为tauopathies。一些伴侣蛋白显示吉祥 结果作为tauopathy模型中的治疗靶标。但是，这项研究建议将 HSP70介导的干预措施，用于发现降低tau水平的化合物。伴侣活动的活动 HSP70由ATP的水解提供动力。此外，许多调节的药理化合物 已显示HSP70的ATP水解速率可以调节Tau的水平：一种化合物 显示抑制Hsp70的ATPase活性的是亚甲基蓝（MB）。 MB已显示可降低tau水平 在各种tauopathy模型中，已被证明可以挽救认知。这些数据表明HSP70 ATPase调制可能是开发抗TAU疗法的可行工具。但是，有很多 描述MB的许多其他相互作用和影响的文献。结果，当前数据创建了一个 与HSP70的ATPase相比，MB作为有前途的治疗候选者更强的病例。 HSP70作为治疗靶点的有力证据将使药物开发人员能够创建新的化合物 可以持有tauopathies的治疗方法。因此，我们创建了基于遗传学的新工具来研究这一点 问题是为了收集支持或反驳假设的数据。我们创建了单个氨基 HSP70的酸突变体并测试了其ATPase和重折叠活性及其对TAU水平的影响。一 HSP70上的E175S突变降低了其ATPase活性和重折叠活性。此外，它减少了tau tauopathy细胞模型的水平。因此，我们复制了使用HSP70抑制剂的先前的体外数据 化合物。这项研究的目的是检验抑制HSP70 ATPase活性的假设 通过细胞降解途径降解tau。为了实现这一目标，我们的设计包括以下 具体目的：1）我们将阻止和激活蛋白酶体，大自源和伴侣辅助辅助 在HSP70E175S过表达的情况下，自噬途径； 2）我们将确定是否抑制 HSP70的ATPase活性减少了体内TAU，并评估了该策略的治疗潜力。