ALTERED PGP AND MRP TRANSPORTERS IN BLOOD BRAIN BARRIER

血脑屏障中 PGP 和 MRP 转运蛋白的改变

• 批准号: 6012317
• 负责人: DONALD W MILLER
• 金额: $ 7.3万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-30 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6012317
• 关键词: P glycoprotein; age difference; blood brain barrier; gene expression; laboratory rat; macromolecule; membrane transport proteins; multidrug resistance; neuronal transport; polymerase chain reaction; protein structure function; tissue /cell culture; vascular endothelium permeability

Changes in the expression and function of transport proteins within the blood-brain barrier (BBB) are known to occur during the natural aging process. In the present proposal, the effects of age on the expression and function of P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP) in the brain microvessel endothelial cells that form the BBB will be evaluated. Both P-gp and MRP are efflux transport proteins that actively transport a wide variety of drugs and macromolecules out of the cell. The development of drug resistance in cancer cells has been attributed to over expression of P-gp and MRP. The expression of these same efflux transport proteins in normal cells, such as the brain microvessel endothelial cells that form the BBB, are believed to play a protective role, preventing the accumulation of potentially toxic compounds in the brain. The hypothesis of the current proposal is that the expression and/or functional activity of P-gp and MRP in the BBB changes as a function of age. Using brain microvessel endothelial cells harvested from female Fisher 344 rats at 3, and 18 months of age, the specific aims of the proposal are to: 1) examine age-related differences in the expression of P-gp and MRP in freshly isolated brain microvessel endothelial cells and primary cultured rat BMEC monolayers; and 2) examine age-related differences in the cellular accumulation and transcellular permeability of P-gp and MRP probes in confluent rat BMEC monolayers. Expression of P-gp and MRP will be evaluated at both the protein and RNA level using quantitative immunoblot and RT-PCR techniques, respectively. Functional activity of P-gp and MRP in the BBB will be assessed by examining the cellular accumulation and bi-directional differences in the permeability of selected P-gp and MRP probes in primary rat BMEC monolayers. Given the putative protective role of these two drug efflux transporters in the BBB, age- related alterations in the expression or function of P-gp and MRP could lead to increased susceptibility to endogenous factors and xenobiotics that impair central nervous system function.

已知在自然衰老过程中发生传输蛋白（BBB）中转运蛋白的表达和功能的变化。 在本建议中，将评估年龄对脑微血管内皮细胞中P-糖蛋白（P-GP）和多药抗性相关蛋白（MRP）的表达和功能的影响。 P-gp和MRP都是外排运输蛋白，它们将各种各样的药物和大分子从细胞中运送出来。 癌细胞中耐药性的发展归因于P-gp和MRP的过度表达。 据信，这些相同的外排传输蛋白在正常细胞中的表达（例如形成BBB的脑微血管内皮细胞）发挥了保护作用，从而阻止了大脑中潜在的有毒化合物的积累。 当前建议的假设是，BBB中P-gp和MRP的表达和/或功能活性随着年龄的变化而变化。 使用脑微血管在3和18个月大的雌性Fisher 344大鼠收获的脑微血管内皮细胞，该提案的具体目的是：1）检查新鲜分离的脑部微系数中P-gp和MRP的年龄相关差异2）检查汇合大鼠BMEC单层中P-gp和MRP探针的细胞积累和跨细胞渗透性的年龄相关差异。 P-gp和MRP的表达将分别在蛋白质和RNA水平上分别使用定量免疫印迹和RT-PCR技术评估。 P-gp和MRP在BBB中的功能活性将通过检查一级大鼠BMEC单层中选定的P-gp和MRP探针的细胞积累和双向差异来评估。 鉴于这两种药物外流转运蛋白在BBB中的推定保护作用，P-gp和MRP的表达或功能的年龄相关变化可能会导致对内源性因子和内源性因素和异种生物的敏感性增加，从而损害了中枢神经系统的功能。