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）：研究表明，通过所谓的“汇效应”，外周清除淀粉样β肽可降低大脑中的淀粉样β肽水平。我们利用这种“下沉效应”，证明肽酶neprilysin在白细胞外周表达时，降低了hAPP转基因阿尔茨海默病小鼠模型大脑中的淀粉样蛋白-肽水平。为了获得外周neprilysin的表达，我们将表达neprilysin的慢病毒转导的骨髓干细胞移植到hAPP转基因小鼠受体中。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。在不需要骨髓移植的情况下，进一步发展外周neprilysin表达的两个特定目标被提出：测试单链抗体- NEP （NEP）嵌合蛋白靶向红细胞降低脑淀粉样肽水平的使用。针对小鼠红细胞表位的单链抗体组成的嵌合蛋白将与neprilysin融合，用于生产红细胞结合的neprilysin，该蛋白将被用于测试降低脑淀粉样蛋白β肽水平的能力。具体目标2。试验利用肉豆粕化NEP蛋白将NEP附着在造血细胞上。我们将生成一种neprilysin，其中肉豆蔻酰肽连接到c端。这种肉豆浆酰基NEP将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肽水平的能力。我们的总体目标是将这些方法中的一种转化为人类受试者的测试。公共卫生相关性：本提案的重点是开发一种治疗阿尔茨海默病的新治疗方法。我们建议在血细胞上表达neprilysin酶，在那里它可以降解血浆淀粉样蛋白β肽，从而降低脑淀粉样蛋白β肽，这是已知的在引起阿尔茨海默病中起主要作用的酶。