CYSTATIN C INHIBITOR OF NEURONAL ABNORMALITIES IN AD

胱氨酸蛋白酶抑制剂 C 抑制 AD 神经元异常

• 批准号: 6920488
• 负责人: EFRAT LEVY
• 金额: $ 23.8万
• 依托单位: NATHAN S. KLINE INSTITUTE FOR PSYCH RES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920488
• 关键词: Alzheimer' s disease; Downs syndrome; autophagy; cathepsin B; cathepsin D; cellular pathology; endocytosis; gene expression; genetically modified animals; human tissue; laboratory mouse; lysosomes; molecular pathology; neuropathology; neuroprotectants; postmortem; protease inhibitor; protein localization; tissue /cell culture

Early endosomal, autophagic, and lysosomal systems (EALS) abnormalities and elevation of cathepsin synthesis are observed at early stages of Alzheimer's disease (AD) and Trisomy 21 (Ts21; Down syndrome). While emerging evidence show that cathepsins play an important role in initiating and mediating cell death, very little is known about in vivo regulation of cathepsins by endogenous inhibitors. Data show that the cysteine protease inhibitor cystatin C (CysC) has a protective role in brain injury and is involved in the early stages of AD. We propose to define the participation of CysC in the early and progressive activation and disruption of the EALS and to test the hypothesis that while EALS dysfunction and cathepsins elevation in AD promotes neurodegeneration, mobilization of CysC can alleviate specific consequences of the EALS pathologies observed in AD. The specific aims are: (1) To determine the cellular vesicles containing CysC and the spatial relationship of the inhibitor to lysosomal hydrolases (including cathepsins B and D) in a wel-lcharacterized collection of postmortem human AD and Ts21 brains; (2) To test in vivo our hypothesis that CysC plays a neuroprotective role in the pathobiology of AD-related EALS dysfunction in mouse models with endocytic and autophagic pathway alterations and determine whether CysC overexpression rescues and CysC deficiency promotes both EALS dysfunction and the aging-related neurodegenerative phenotype in each of these models; and (3) To study the molecular mechanism underlying the protective role of CysC, using cell culture paradigms varying in the nature of their EALS pathology or exposed to injury that results in abnormal activation or blockage of specific pathways within the EALS. Manipulating CysC levels, using cells derived from either CysC overexpressing or CysC knockout mice, and cells transfected with either CysC cDNA or CysC siRNA, will serve to demonstrate the protective role of CysC.

在阿尔茨海默病 (AD) 和 21 三体症（Ts21；唐氏综合症）的早期阶段，可以观察到早期内体、自噬和溶酶体系统 (EALS) 异常以及组织蛋白酶合成升高。虽然新的证据表明组织蛋白酶在启动和介导细胞死亡中发挥重要作用，但人们对内源性抑制剂对组织蛋白酶的体内调节知之甚少。数据显示，半胱氨酸蛋白酶抑制剂胱抑素C（CysC）对脑损伤具有保护作用，并参与AD的早期阶段。我们建议定义 CysC 在 EALS 的早期和渐进激活和破坏中的参与，并检验这样的假设：虽然 AD 中 EALS 功能障碍和组织蛋白酶升高会促进神经退行性变，但 CysC 的动员可以减轻 EALS 的特定后果 AD 中观察到的病理。具体目标是：（1）确定含有 CysC 的细胞囊泡以及抑制剂与溶酶体水解酶（包括组织蛋白酶 B 和 D）的空间关系，在一组经过良好表征的死后人类 AD 和 Ts21 大脑中； (2) 为了在体内测试我们的假设，即 CysC 在具有内吞和自噬途径改变的小鼠模型中的 AD 相关 EALS 功能障碍的病理学中发挥神经保护作用，并确定 CysC 过度表达是否可以挽救以及 CysC 缺乏是否会促进 EALS 功能障碍和衰老。相关神经退行性表型 这些模型中的每一个； (3) 研究 CysC 保护作用背后的分子机制，使用不同 EALS 病理性质或暴露于导致 EALS 内特定途径异常激活或阻塞的损伤的细胞培养范例。使用来自 CysC 过表达或 CysC 敲除小鼠的细胞以及用 CysC cDNA 或 CysC siRNA 转染的细胞来操纵 CysC 水平，将有助于证明 CysC 的保护作用。