Neprilysin and Peripheral Clearance of Amyloid Peptides

脑啡肽酶和淀粉样肽的外周清除

• 批准号: 7858439
• 负责人: Louis B. Hersh
• 金额: $ 18.48万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7858439
• 关键词: Abeta clearance; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Antibodies; Binding; Blood; Blood Cells; Blood Platelets; Bone Marrow Cells; Bone Marrow Stem Cell; Bone Marrow Transplantation; Brain; Cell membrane; Cell surface; Cells; Chimera organism; Chimeric Proteins; Complement; Enzymes; Epitopes; Erythrocytes; Ganglioside GM1; Gelsolin; Hematopoietic; Human; Hydrolysis; Impaired cognition; Injection of therapeutic agent; Leukocytes; Link; Lymphocyte; Measures; Methods; Mus; Neprilysin; Peptide Hydrolases; Peptides; Peripheral; Plasma; Play; Principal Investigator; Proteins; Public Health; Role; Subfamily lentivirinae; Tail; Testing; Therapeutic; Transgenic Mice; Translations; Transplantation; Veins; amyloid peptide; human subject; immunogenicity; morris water maze; mouse model; novel therapeutic intervention; prevent; programs

DESCRIPTION (provided by applicant): It has been shown that peripheral clearance of amyloid beta peptides reduces amyloid beta peptide levels in the brain through what has been termed a "sink effect". We have exploited this "sink effect" by showing that the peptidase neprilysin, when expressed peripherally on leukocytes reduced amyloid beta peptide levels in the brain of a hAPP transgenic mouse model of Alzheimer's disease. To obtain peripheral neprilysin expression we transplanted bone marrow stem cells transduced with lentivirus expressing neprilysin to a recipient hAPP transgenic mouse. We now propose to further develop peripheral expression of neprilysin as a therapeutic treatment for AD. Two specific aims directed at further developing peripheral neprilysin expression, without the need for bone marrow transplantation, are proposed: SPECIFIC AIM 1. To test the use of a single chain antibody-neprilysin (NEP) chimeric protein targeted to red blood cells to lower brain amyloid beta peptide levels. Chimeric proteins composed of a single chain antibody targeted to a mouse erythrocyte epitope fused with neprilysin will be used to produce erythrocyte bound neprilysin which will be tested for the ability to lower brain amyloid beta peptide levels. SPECIFIC AIM 2. To test the use of a myristoylated-neprilysin to attach NEP to hematopoietic cells. We will generate a form of neprilysin in which a myristoyl-peptide is linked to the C-terminus. This myristoyl-NEP will be used to produce peripheral NEP by insertion into the plasma membrane of hematopoietic cells and tested for the ability to lower brain amyloid beta peptide levels. We have as an overall objective the translation of one of these methods to the testing of human subjects. PUBLIC HEALTH RELEVENCE: The focus of this proposal is to develope a new therapeutic approach for treating Alzheimer's disease. We propose to express the enzyme neprilysin on blood cells where it can degrade plasma amyloid beta peptides leading to a lowering of brain amyloid beta peptides which are known to play a major role in causing Alzheimer's disease.

描述(由申请人提供)：已有研究表明，淀粉样β多肽的外周清除通过所谓的“下沉效应”降低了大脑中的淀粉样β多肽水平。我们通过证明当外周表达在白细胞上的肽酶neprilysin降低了Happ转基因阿尔茨海默病小鼠模型大脑中的淀粉样β多肽水平，从而利用了这种“汇聚效应”。为了获得外周Neprilysin的表达，我们将转导了表达neprilysin的慢病毒的骨髓干细胞移植到受体HAPP转基因小鼠。我们现在建议进一步开发Neprilysin的外周表达作为AD的治疗方法。针对进一步发展外周血中Neprilysin的表达，而不需要骨髓移植，提出了两个特定的目标：特异性目标1.测试以红细胞为靶点的单链抗体-neprilysin(NEP)嵌合蛋白降低脑淀粉样β蛋白水平的作用。由针对小鼠红细胞表位的单链抗体与neprilysin融合而成的嵌合蛋白将被用来产生与红细胞结合的neprilysin，并将测试其降低大脑淀粉样β肽水平的能力。特异性目的2.检测肉豆蔻酰化奈普利菌素与造血细胞结合NEP的作用。我们将产生一种形式的Neprilysin，在这种形式中，肉豆蔻基多肽连接到C-末端。这种肉豆蔻基-NEP将被用于通过插入造血细胞的质膜来产生外周NEP，并测试其降低脑淀粉样β蛋白水平的能力。我们的总体目标是将其中一种方法转化为对人类受试者的测试。公共卫生研究进展：这项提议的重点是开发一种治疗阿尔茨海默病的新方法。我们建议在血细胞上表达neprilysin酶，它可以降解血浆淀粉样β多肽，导致脑内淀粉样β多肽的降低，而已知的淀粉样β多肽在导致阿尔茨海默病中起主要作用。