MRP-MEDIATED DRUG TRANSPORT IN THE BBB

描述：这项研究的目的是描述 药物外排过程中的多药耐药相关蛋白 来自中枢神经系统(CNS)。西北S a膜结合运输 属于ATP结合盒运输超家族的蛋白质 蛋白质，并且在几种多药耐药(MDR)中过表达 癌细胞系。多药耐药癌症是癌症中的一个重要挑战 化疗。糖蛋白(P-gp)介导的药物的几种抑制剂 外排目前正在进行临床试验，还有几种化合物正在进行临床试验 正在开发中，专门用于P-GP和NW调制。与P-GP一样，NW也是 在许多具有分泌和屏障功能的正常组织中发现，以及 它是在大脑中表达的。然而，细胞类型定位和 中枢神经系统的功能研究尚未见报道。这项研究 目标涉及假设NW底物向 中枢神经系统依赖于NW在脑组织中的表达和功能 血脑屏障(BBB)和血脑脊液屏障(BCSFB)。目标将是 描述BBB中NW外排泵的功能能力 在体外和体内模型中使用药物动力学分析 抑制MRP对NW底物在脑内分布的影响。这个 具体目标如下：1)表征 An中选择的NW底物的细胞积累和定向通量 血脑屏障体外模型，脑内皮细胞单层，2)检测 神经营养因子在脑内皮细胞单层的表达和定位， 3)表征使用In的NW底物的CNS分布动力学 脑细胞外液和脑脊液中的活体微透析，以及4) 确定急性或长期暴露于NW抑制剂是否会改变 由于BBB中NW的诱导，运输系统的能力。这个 大脑中MRP的功能容量将通过检查 已知的NW转运蛋白抑制剂(丙磺舒，LTD4)的作用 拮抗剂(MK-571)，来自礼来公司的铅，如LY-329146) NW底物荧光素、钙黄绿素和LTC4的体外动力学 血脑屏障模型的建立及活体脑微透析的应用。刻画 NW在限制CNS药物暴露方面所起的作用将指导设计 NW介导的安全药理调节的治疗方法 多药耐药癌症。此外，这些研究将进一步了解 NW的生理相关性及其与长期描述的有机物质的关系 阴离子传输系统。

DESCRIPTION: The objective of this research is to characterize the role of the multi-drug resistance-associated protein (MRP) in drug efflux processes from the central nervous system (CNS). NW s a membrane-bound transport protein belonging to the ATP-binding cassette superfamily of transport proteins, and it is overexpressed in several multidrug resistant (MDR) cancer cell lines. MDR cancers represent an important challenge in cancer chemotherapy. Several inhibitors of the glycoprotein (P-gp) -mediated drug efflux are currently in clinical trials, and several more compounds are under development specifically for P-gp and NW modulation. Like P-gp, NW is found in many normal tissues that have secretary and barrier functions, and it is expressed in the brain. However, cell-type localization and functional studies in the CNS have not been reported. The research objective relates to the hypothesis that the transport of NW substrates to the CNS depends on the expression and functional capacity of NW in the blood-brain (BBB) and blood-CSF barriers (BCSFB). The goal will be to characterize the functional capacity of the NW efflux pump in the BBB in both in vitro and in vivo models using a pharmacokinetic analysis of the effect of MRP inhibition on NW substrate distribution to the brain. The Specific Aims are as follows: 1) to characterize the kinetics of the cellular accumulation and directional flux of selected NW substrates in an in vitro model of the BBB, brain endothelial cell monolayers, 2) to examine the expression and localization of NW on brain endothelial cell monolayers, 3) to characterize the CNS distributional kinetics of NW substrates using in vivo microdialysis in the brain extracellular fluid and the CSF, and 4) to determine if acute or chronic exposure to an NW inhibitor will change the capacity of the transport system due to induction of NW in the BBB. The functional capacity of MRP in the brain will be determined by examining the effect of known inhibitors of the NW transporter (probenecid, LTD4 antagonist (MK-571), and leads from Lilly, e.g., LY-329146) on the CNS kinetics of NW substrates, fluorescein, calcein and LTC4, in an in vitro model of the BBB and utilizing in vivo brain microdialysis. Characterizing the role NW plays in limiting CNS drug exposure will guide the design of therapeutic approaches for the safe pharmacologic modulation of NW-mediated MDR cancer. Moreover, these studies will further understanding of the physiological relevance of NW and its relationship to long-described organic anion transport systems.