Novel mechanisms for Alzheimer disease prevention and or treatment

预防和/或治疗阿尔茨海默病的新机制

• 批准号: 10455418
• 负责人: Luigi Puglielli
• 金额: --
• 依托单位: WM S. MIDDLETON MEMORIAL VETERANS HOSP
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10455418
• 关键词: Acetyl Coenzyme A; Acetylation; Acetyltransferase; Affect; Age; Aging; Alzheimer disease prevention; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease risk; American; Animal Disease Models; Animal Model; Autophagocytosis; Biochemical; Biochemical Reaction; Biomedical Research; Cardiovascular Diseases; Cell Nucleus; Cell model; Cellular Structures; Chronic; Chronic Disease; Clinical; Country; Cytoplasm; Cytosol; Data; Degenerative Disorder; Dementia; Development; Disease; Disease model; Education; Elderly; Endoplasmic Reticulum; Ensure; Equilibrium; Event; Formulation; Genetic; Glutamate-ammonia-ligase adenylyltransferase; Goals; Healthcare; Hospitals; Immune System Diseases; Impaired cognition; In Vitro; Kidney Diseases; Laboratories; Light; Link; Longevity; Lysine; Malignant Neoplasms; Medical; Membrane Transport Proteins; Mission; Molecular; Molecular Biology; Mus; Nerve Degeneration; Outcome; Pathogenesis; Pathway interactions; Pharmacology; Phenotype; Play; Population; Prevention; Progeria; Quality of Care; Regulation; Reporting; Research; Research Design; Risk Factors; Role; Specificity; Structural Biochemistry; Structure; Testing; United States Department of Veterans Affairs; aged; aging population; base; clinical center; cognitive disability; cost; disability; improved; in vivo; inhibitor; military veteran; mouse model; neuropathology; novel; polypeptide; prevent; protein aggregation; proteostasis

PROBLEM: Aging is the most important risk factor for Alzheimer's disease (AD), which represents the most common cause of dementia in our country. The disease, for which there is no currently available treatment, is becoming increasingly prevalent among our aging veteran population. PRELIMINARY DATA: Autophagy is an essential component of the cell degrading machinery. It helps dispose of large toxic protein aggregates that form within the secretory pathway and in the cytosol. Malfunction of autophagy and disruption of proteostasis contributes to the progression of many chronic diseases. In addition, many chronic degenerative diseases are characterized by the aberrant accumulation of toxic protein aggregates. Compelling data indicate that increased levels of autophagy can be beneficial in mouse models of diseases characterized by increased accumulation of toxic protein aggregates, including AD. As such, improving normal proteostatic mechanisms is an active target for biomedical research. Nε- lysine acetylation was initially thought to occur only in the cytoplasm and nucleus. However, in 2007 we discovered that the endoplasmic reticulum (ER) is also able to acetylate newly-synthesized polypeptides. Since then, we have successfully identified the entire biochemical machinery responsible for ER-acetylation and generated relevant animal models. The machinery includes AT-1, which translocates acetyl-CoA from the cytosol to the ER lumen, and ATase1/ATase2, two acetyltransferases that carry out the enzymatic reaction within the ER lumen. We discovered that the ER acetylation machinery maintains the homeostatic balance of two essential and intimately related functions of the ER: (i) “positive” selection of correctly folded nascent polypeptides and (ii) tight regulation of autophagy/reticulophagy. Mice with reduced influx of acetyl- CoA into the ER (AT-1S113R/+) display excessive induction of autophagy and a block of the secretory pathway while mice with increased influx (AT-1 Tg and AT-1 sTg) display increased efficiency of the secretory pathway and a block of normal reticulophagy. In both cases, lack of homeostatic balance leads to drastic phenotypes. Relevant to this proposal is also the fact that a dysfunctional ER acetylation machinery has been linked to aging and AD. Consistently, haploinsufficiency of AT-1 or biochemical inhibition of the ATases was able to rescue the AD-like phenotype in the mouse. HYPOTHESIS: Our general hypothesis is that the ER acetylation machinery ensures protein homeostasis. Deregulation of this cross-talk impacts both aging and AD. STUDY DESIGN: Specific Aim 1 will identify novel structure-based ATase1 and ATase2 inhibitors to prevent AD. This Aim will take advantage of new structural information that we have collected on the ATases and new structure-based inhibitors that we have recently identified. Relevant structural biochemistry, in vitro and ex vivo analysis, and pre-formulation/formulation development of these novel compounds have already been completed. They will now be tested in two mouse models of AD. This Aim will also take advantage of ATase1-/- and ATase2-/- mice, recently generated in our laboratory to determine whether targeting only one ATase is sufficient to rescue AD neuropathology in the mouse. Specific Aim 2 will identify the molecular mechanism(s) that provides specificity to the proteostatic functions of the ER acetylation machinery. Under this Aim we report the identification of a novel ER-based acetyltransferase that appears to play an important role in the regulation of autophagy/reticulophagy down-stream of the ER acetylation machinery. This Aim is highly mechanistic and includes a combination of structural biochemistry, molecular biology and in vitro/ex vivo analysis.

问题：衰老是阿尔茨海默病（AD）最重要的危险因素， 最常见的痴呆症病因这种疾病目前还没有 治疗，在我们老龄化的退伍军人群体中越来越普遍。 初步资料：自噬是细胞降解机制的重要组成部分。它有助于 处理在分泌途径和胞质溶胶中形成的大的毒性蛋白质聚集体。 自噬的功能障碍和蛋白质稳态的破坏有助于许多慢性肿瘤的进展， 疾病此外，许多慢性退行性疾病的特征是异常积累 有毒的蛋白质聚集体。令人信服的数据表明，自噬水平的增加可能有利于 特征为毒性蛋白聚集体积累增加的疾病的小鼠模型，包括 AD.因此，改善正常的蛋白质抑制机制是生物医学研究的一个积极目标。Nε- 赖氨酸乙酰化最初被认为仅发生在细胞质和细胞核中。2007年，我们 发现内质网（ER）也能够乙酰化新合成的多肽。 从那时起，我们已经成功地确定了负责ER-乙酰化的整个生化机制 并建立了相关的动物模型。这种机制包括AT-1，它将乙酰辅酶A从 和ATase 1/ATase 2，这两种乙酰转移酶进行酶促 ER腔内反应。我们发现内质网乙酰化机制维持了 ER的两个基本和密切相关的功能的平衡：（i）“积极”选择正确折叠的 新生多肽和（ii）自噬/网状吞噬的紧密调节。乙酰基内流减少的小鼠 CoA进入ER（AT-1 S113 R/+）显示过度诱导自噬和阻断分泌途径 而内流增加的小鼠（AT-1 Tg和AT-1 sTg）显示出分泌效率增加， 通路和正常网状吞噬功能的阻断。在这两种情况下，缺乏内稳态平衡会导致剧烈的 表型与该提议相关的事实还有，功能失调的ER乙酰化机制已经 与衰老和AD有关。AT-1的一致性、单倍不足或 ATases能够挽救小鼠中的AD样表型。 假设：我们的一般假设是，ER乙酰化机制确保蛋白质 体内平衡这种串扰的失调影响衰老和AD。 研究设计：特异性目的1将鉴定新的基于结构的ATase 1和ATase 2抑制剂， 预防AD。本目标将利用我们收集到的关于 ATases和新的结构为基础的抑制剂，我们最近发现。相关结构 生物化学、体外和离体分析以及这些新的制剂的预制剂/制剂开发。 化合物已经完成。他们现在将在两个AD小鼠模型中进行测试。这一目标 还将利用我们实验室最近产生的ATase 1-/-和ATase 2-/-小鼠来确定 仅靶向一种AT酶是否足以挽救小鼠中的AD神经病理学。具体目标2 将确定为ER的蛋白质抑制功能提供特异性的分子机制 乙酰化机械在这个目标下，我们报告了一个新的ER为基础的乙酰转移酶的鉴定 这似乎在ER下游的自噬/网状吞噬的调节中起重要作用 乙酰化机械这个目标是高度机械化的，包括结构生物化学， 分子生物学和体外/离体分析。