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: 10155429
• 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/10155429
• 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/antagonist; 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，该病代表着 该疾病是我国痴呆症的最常见原因，目前尚无治疗方法。 治疗，在我们老龄化的退伍军人群体中变得越来越普遍。 初步数据：自噬是细胞降解机制的重要组成部分。 处理在分泌途径和细胞质中形成的大的有毒蛋白质聚集体。 自噬功能障碍和蛋白质稳态破坏导致许多慢性疾病的进展 此外，许多慢性退行性疾病的特点是异常积累。 令人信服的数据表明，自噬水平的提高可能有益于 以有毒蛋白质聚集体积累增加为特征的疾病小鼠模型，包括 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。 最初认为赖氨酸乙酰化仅发生在细胞质和细胞核中，然而，2007 年我们发现。 发现内质网（ER）也能够乙酰化新合成的多肽。 从那时起，我们成功鉴定了负责 ER 乙酰化的整个生化机制 并生成了相关的动物模型，其中包括 AT-1，它可将乙酰辅酶 A 转位。 细胞质到 ER 腔，以及 ATase1/ATase2，两种执行酶促作用的乙酰转移酶 内质网管腔内的反应 我们发现内质网乙酰化机制维持稳态。 ER 的两个基本且密切相关的功能的平衡：（i）正确折叠的“积极”选择 新生多肽和（ii）对自噬/网状自噬的严格调节，乙酰基流入减少。 CoA 进入 ER (AT-1S113R/+) 显示过度诱导自噬和分泌途径受阻 而流入量增加（AT-1 Tg 和 AT-1 sTg）的小鼠表现出分泌效率增加 在这两种情况下，体内平衡的缺乏都会导致严重的网状吞噬现象。 与该提议相关的还有一个事实，即功能失调的 ER 乙酰化机制。 AT-1 的单倍体不足或生化抑制与衰老和 AD 一致。 ATase 能够挽救小鼠的 AD 样表型。 假设：我们的一般假设是内质网乙酰化机制确保蛋白质 这种串扰的放松管制会影响衰老和AD。 研究设计：具体目标 1 将鉴定新型基于结构的 ATase1 和 ATase2 抑制剂 该目标将利用我们收集的新结构信息来预防 AD。 我们最近确定了相关结构的 ATase 和新的基于结构的抑制剂。 这些小说的生物化学、体外和离体分析以及预制剂/制剂开发 化合物已经完成，现在将在两种 AD 小鼠模型中进行测试。 还将利用我们实验室最近生成的 ATase1-/- 和 ATase2-/- 小鼠来确定 仅针对一种 ATase 是否足以挽救小鼠的 AD 神经病理学特定目标 2。 将确定为 ER 的蛋白抑制功能提供特异性的分子机制 在这个目标下，我们报告了一种新型的基于内质网的乙酰转移酶的鉴定。 似乎在 ER 下游自噬/网状自噬的调节中发挥重要作用 该目标是高度机械化的，包括结构生物化学的组合， 分子生物学和体外/离体分析。