Mechanisms of Cholinesterase Inhibitors on Beta-amyloid

胆碱酯酶抑制剂对β-淀粉样蛋白的作用机制

• 批准号: 6742502
• 负责人: DEBOMOY K LAHIRI
• 金额: $ 28.91万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6742502
• 关键词: Alzheimer' s disease; SDS polyacrylamide gel electrophoresis; acetylcholinesterase; active sites; amyloid proteins; chemical structure function; cholinesterase inhibitors; drug screening /evaluation; enzyme activity; enzyme mechanism; enzyme structure; genetically modified animals; immunologic assay /test; laboratory mouse; neuropharmacology; nonhuman therapy evaluation; pharmacokinetics; plasmids; protein metabolism; stereoisomer; tissue /cell culture; transfection /expression vector

Alzheimer's disease (AD) is characterized by the severe loss of cholinergic neurons and depositions of amyloid beta peptide (Abeta). Three FDA- approved drugs (tacrine, donepezil and rivastigmine) for treating AD subjects belong to the category of cholinesterase (ChE) inhibitor (ChEI), which works by increasing the brain's supply of acetylcholine, a nerve communication chemical that is deficient in AD. These drugs are approved for treatment of mild to moderate AD and may not be as useful in more advanced stages. Our goal is to study the mechanism of ChEI drugs on amyloidogenic pathways that process beta-amyloid precursor protein (APP) to potentially neurotoxic Abeta. Such study is significant as there is increasing evidence that Abeta plays an important role in AD pathogenesis. This proposal is based on our discovery that treating cultured cells with certain ChEIs, such as tacrine and phenserine, significantly reduced levels of secreted APP (sAPP) and Abeta and may serve to slow the progression of AD as well as improve cognition. Notably, the mechanism of reduction of Abeta did not increase known alternative processing pathways and may therefore be less damaging. We are interested in identification of the mechanisms by which ChEIs block Abeta secretion to take advantage of the Abeta lowering property in developing novel therapeutic agents. SPEC. AIMS: The specific aims are: 1. To study the effects of acetyl- ChEI (AChEI) and butyrl-ChEI (BchEI) on sAPP and Abeta levels. To examine the specificity of their actions, effects of i) AchEI (e.g., pheneserine) ii)BChEI (e.g. cymserine), and iii) compounds that are tacrine-derivatives (e.g. velnacrine) will be tested to identify structural aspects that lower Abeta. 2. To investigate the role of ChEIs on APP metabolism. Effects of ChEIs on i)APP processing in FAD-APP mutant cell lines and ii) the fate of APP carboxyl-truncated fragments will be tested. 3. To determine the possible targets of the drugs. Effects of ChEIs on the i) APP-cleaving enzyme (BACE), ii) 5' -untranslated region and iii) inhibition of Abeta levels in transgenic mice model of AD. We will mechanically select ChEIs that interact with the peripheral allosteric binding domain of ChEenzyme, or with the esteractic and anionic binding domains (phenserine and cymserine) and test it in APP/PS1 double transgenic mice. These results will indicate a unique effect of ChEIs on APP processing, which is independent of their selectivity for the enzyme. This property will be further investigated to maximize their potential effects in decreasing amyloid depositions, and which can be utilized to design better drugs for the treatment of AD.

阿尔茨海默氏病（AD）的特征是胆碱能神经元严重丧失和淀粉样β肽（ABETA）的沉积。 三种用于治疗AD受试者的FDA-批准的药物（四翼胺，多奈哌齐和Rivastigmine）属于胆碱酯酶（CHE）抑制剂（CHEI）类别，它们通过增加大脑的乙酰胆碱的供应而起作用，乙酰胆碱是一种神经通信化学物质，在AD中不足。 这些药物被批准用于治疗轻度至中度AD，并且在更高级的阶段可能不那么有用。 我们的目标是研究CHEI药物在淀粉样蛋白生成途径上的机制，这些淀粉样蛋白生成途径将β-淀粉样蛋白前体蛋白（APP）处理至潜在的神经毒性Abeta。 这种研究很重要，因为越来越多的证据表明Abeta在AD发病机理中起着重要作用。 该提议是基于我们发现的，即用某些CHAI（例如钟氨酸和苯啉）处理培养的细胞，大大降低了分泌的应用程序（SAPP）和Abeta的水平，并可能有助于减慢AD的发展并改善认知。 值得注意的是，减少ABETA的机制并未增加已知的替代处理途径，因此可能会减少损害。 我们有兴趣识别Cheis阻止Abeta分泌利用Abeta降低特性的机制，以开发新型的治疗剂。规格目的：具体目的是：1。研究乙酰基（ACHEI）和丁酸chei（Bchei）对SAPP和Abeta水平的影响。 为了检查其作用的特异性，i）Achei的作用（例如，现象）ii）BCHEI（例如Cymserine）和III）化合物（cyparine衍生物（例如，velnarcine）的化合物，将测试以识别降低Abeta的结构方面。 2。调查Cheis在应用代谢中的作用。 CHEI对I）fad-app突变细胞系中的应用程序处理和ii）App羧基截断的片段的命运将被测试。 3。确定药物的可能靶标。 CHEI对I）APP交流酶（bace），II）5'非翻译区和III的影响抑制AD的转基因小鼠模型中ABETA水平的抑制作用。 我们将机械选择与Cheenzyme的外围变构结合结构域相互作用的CHEI，或与酯和阴离子结合结构域（Phenserine和Cymserine）相互作用，并在App/PS1双转基因小鼠中对其进行测试。 这些结果将表明CHEI对应用程序处理的独特效果，这与其对酶的选择性无关。将进一步研究该特性，以最大程度地提高其在减少淀粉样沉积的潜在影响，并可以用来设计更好的药物来治疗AD。