PrP-scrapie transport across intestinal & BBB

PrP-痒痒症跨肠道转运

• 批准号: 6951191
• 负责人: Neena Singh
• 金额: $ 26.78万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-20 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6951191
• 关键词: blood brain barrier; clinical research; communicable disease transmission; ferritin; food chain contamination; gastrointestinal epithelium; gene expression; gene mutation; genetic models; genetically modified animals; host organism interaction; human tissue; iron oxide; laboratory mouse; postmortem; prions; protein transport; scrapie; spongiform encephalopathy; tissue /cell culture; transferrin; virus genetics; virus infection mechanism; virus protein; virus replication

DESCRIPTION (provided by applicant): The transmission of variant Creutzfeldt-Jakob disease (vCJD) to humans from bovine-spongiform encephalopathy (BSE)-contaminated meat, and the transmission of BSE by intra-venous inoculation of peripheral blood to experimental animals raises two important questions: 1) how are prions from food transported across the intestinal epithelial barrier, and 2) how do prions in the peripheral blood cross the endothelial blood brain barrier (BBB). These questions have gained increasing importance with the realization that close to one million BSE infected cows may have entered the human food chain. An emerging concern is the spread of Chronic Wasting Disease (CWD), a prion disease of the deer and elk in certain parts of USA, and the uncertainties regarding its transmission to livestock and humans. Despite these concerns, surprisingly little is known about the mechanism(s) by which the infectious prion or PrP-scrapie (PrPsc), a protein of 27-30kDa, is transported from the intestine or peripheral blood to the central nervous system. Preliminary data from my laboratory demonstrate that PrPsc in sporadic CJD (sCJD) brain homogenates is transported across epithelial cells in association with ferritin. When considered in context with additional data indicating an upregulation of brain ferritin levels in response to redox active iron in the brain parenchyma of sCJD cases, this observation raises important questions. We hypothesize that the transport of PrPsc across epithelial and endothelial cell barriers is facilitated by proteins like ferritin that have a defined transcytotic route, and that imbalance of brain iron homeostasis contributes directly to the pathogenesis of certain prion disorders, and indirectly by promoting infectivity through ferritin. Thus, the central goal of this proposal is to investigate the role of PrPs-associated proteins including ferritin and transferrin in facilitating its transport across the intestinal epithelium and the BBB, and to evaluate the role of redox active iron in the pathogenesis of prion disorders. The proposed studies will be carried out in three specific aims. In aim 1, the role of ferritin, transferrin, and other PrPsc-associated proteins in the transport of PrPsc across in vitro models of human intestinal epithelial cell barrier and the BBB will be evaluated. In aim 2, the results obtained from in vitro models in aim 1 will be confirmed in vivo in transgenic mice expressing human PrP. In aim 3, the role of redox active iron in the pathogenesis of priori disorders will be investigated using ferritin over-expressing and H-ferritin deletion transgenic mice. These studies will help in evaluating the risk of human population to BSE, vCJD, and CWD infection, and help in understanding the mechanism of prion disease pathogenesis.

描述（由申请人提供）：变异的克鲁特兹菲尔特 - 贾科布疾病（VCJD）传播到人类到人类，从牛长孢子脑病（BSE）污染的肉（BSE）的肉类传播，而BSE通过周围的血液内部接种BSE传播，将外围血液接种到实验性动物中，实验性动物两种重要的问题：1）在两种情况下，涉及两种兴趣：1）遍布食物的方式：1）涉及食物的含量：1）涉及食物的范围。周围血液中的王室穿越内皮血液脑屏障（BBB）。随着接近一百万BSE感染的奶牛可能进入人类食物链的意识，这些问题已越来越重要。一个新出现的关注是慢性浪费疾病（CWD）的传播，美国某些地区的鹿和麋鹿的prion病，以及其向牲畜和人类传播的不确定性。尽管有这些担忧，但令人惊讶的是，关于传染性prion或Prp-scrapie（PRPSC）的机制知之甚少，该机制是27-30kDa的蛋白质，从肠道或外围血液传输到中枢神经系统。 我的实验室的初步数据表明，散发性CJD（SCJD）脑匀浆中的PRPSC与铁蛋白相关。当在其他数据中考虑表明脑铁蛋白水平的上调，以响应SCJD病例的脑实质中的氧化还原活性铁的上调，该观察结果提出了重要的问题。我们假设PRPSC在上皮和内皮细胞屏障中的运输是由具有定义的经诊断途径的蛋白质促进的，而蛋白质的运输是脑铁稳定途径的蛋白质，并且脑铁稳态的失衡直接有助于某些PRION障碍的发病机理，并通过通过纤维素促进感染性来促进某些Prion脑抑制剂。因此，该提案的核心目标是研究PRPS相关蛋白在内的作用，包括铁蛋白和转铁蛋白在促进其跨肠上皮和BBB的转运中，并评估氧化还原活性铁在Prion疾病的发病机理中的作用。拟议的研究将以三个特定目的进行。在AIM 1中，将评估铁蛋白，转铁蛋白和其他与PRPSC相关的蛋白在PRPSC跨越人类肠上皮细胞屏障的体外模型和BBB跨体外模型中的作用。在AIM 2中，在AIM 1中从体外模型获得的结果将在表达人PRP的转基因小鼠的体内确认。在AIM 3中，将使用铁蛋白过表达和H-铁蛋白缺失转基因小鼠研究氧化还原活性铁在先验疾病发病机理中的作用。这些研究将有助于评估人口对BSE，VCJD和CWD感染的风险，并有助于理解王室疾病发病机理的机理。