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系统疾病的一个有前景的治疗靶点 蛋白质错误折叠。这是因为它们能够与错误折叠的“客户”蛋白质相互作用并 容易聚集。这些客户之一，微管相关蛋白 tau，异常聚集在 许多神经退行性疾病被称为 tau蛋白病。一些伴侣蛋白显示出吉祥的迹象 结果作为 tau 蛋白病模型的治疗靶点。然而，这项研究建议增加证据 Hsp70 介导的干预措施，用于发现降低 tau 水平的化合物。陪伴活动 Hsp70 由 ATP 水解提供动力。此外，许多药理化合物可以调节 Hsp70 的 ATP 水解速率已被证明可以调节 tau 蛋白的水平：一种化合物 亚甲蓝 (MB) 被证明可以抑制 Hsp70 的 ATP 酶活性。 MB 已被证明可以降低 tau 水平 在各种 tau 蛋白病模型中，并已被证明可以挽救认知。这些数据表明 Hsp70 ATPase 调节可能是开发抗 tau 疗法的可行工具。然而，有大量的 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 与 Hsp70 的 ATP 酶作为治疗靶点相比，MB 作为有前途的治疗候选者更有力。 Hsp70 作为治疗靶点的有力证据将使药物开发商能够创造出新的化合物 可能可以治愈 tau蛋白病。因此，我们创建了新的基于遗传学的工具来研究这一问题 问题以收集支持或反驳假设的数据。我们创造了单氨基 Hsp70 的酸性突变体并测试了它们的 ATP 酶和重折叠活性以及它们对 tau 水平的影响。一 Hsp70 上的突变 E175S 会降低其 ATP 酶活性和重折叠活性。此外，它还能减少 tau tau蛋白病细胞模型中的水平。因此，我们复制了之前使用 Hsp70 抑制剂的体外数据 化合物。本研究的目的是检验以下假设：Hsp70 ATPase 活性的抑制 通过细胞降解途径降解 tau 蛋白。为了实现这一目标，我们的设计包括以下内容 具体目标：1）我们将阻断和激活蛋白酶体、巨自噬和伴侣辅助 Hsp70E175S 过表达时的自噬途径； 2）我们将确定是否抑制 Hsp70 的 ATP 酶活性可减少体内 tau 蛋白，并评估该策略的治疗潜力。