Control of Drug Delivery to the CNS: Modulating P-glycoprotein Activity

描述(由申请人提供)： 项目概要项目描述研发项目首席研究员(S)班克斯，威廉A项目标题(不超过72个字符间距)中枢神经系统药物输送的控制：调节P-糖蛋白活性关键词(网格项；至少三个)药物，血脑屏障，脑，中枢神经系统，P-糖蛋白，固有免疫系统，细胞因子，肿瘤坏死因子-α，一氧化氮研究目标简述(不使用续篇)开发有效的脑疗法的一个主要问题是血脑屏障，它将许多药物排除在中枢神经系统(CNS)之外。血脑屏障排除药物的一个主要机制是通过P-糖蛋白(P-gp)。P-gp是一种脑-血(外排)泵，位于血脑屏障的管腔一侧，阻止其配体进入中枢神经系统。P-gp对数量惊人的临床用药有亲和力。P-gp活性的增加进一步限制了其配体对中枢神经系统的访问，从而使许多中枢神经系统药物失效，而P-gp活性的降低则允许更多的药物进入中枢神经系统，从而增强了作用。我们的长期目标是学习如何控制P-gp的活性，从而控制其配体向中枢神经系统的输送。最近对脑内皮细胞的体外研究已经证明了一系列调节P-gp活性的事件。脑血管内皮细胞上的P-gp被脂多糖(LPS)和肿瘤坏死因子α(TNF)抑制。它们依次刺激内皮素-1(ET-1)，它通过其B受体(ETRB)作用于增加一氧化氮合酶(NOS)的活性，在几分钟内作用于降低P-gp的活性。这个途径还通过ET-1受体ETRA和ETRB刺激NFkB增加P-gp的表达，在数小时内产生P-gp的长期刺激：TNF-&gt；ET-1(etra/ETRB)-&gt；NOS-&gt；NFkB-&gt；mRNA(P-gp)-&gt；增加P-gp的活性。我们的目标是确定这些机制是否在体内起作用。我们的工作假设是：在体内，P-gp的活性受肿瘤坏死因子、内皮素-1和一氧化氮合酶的顺序激活的调节。我们的具体目标是：SA 1：在小鼠体内确定肿瘤坏死因子对P-gp的短期和长期影响。SA2：在小鼠体内研究ET-1对内毒素诱导的P-gp变化的影响。SA 3：在小鼠体内测定一氧化氮合酶对P-gp的短期和长期影响。对退伍军人保健的潜在影响：如果这种级联反应的全部或部分在体内活跃，那么P-gp活性很可能在一系列疾病中发生改变，从而导致中枢神经系统药物活性的改变。这些疾病不仅包括细菌败血症，还包括类风湿性关节炎、糖尿病、中风、中枢神经系统癌症，甚至肥胖症和阿尔茨海默氏症，在这些疾病中存在促炎和神经炎性疾病。这项拟议的工作将对医疗保健产生三个主要影响：1)它将有助于识别P-gp活性改变导致中枢神经系统药物谱改变的药物和疾病；2)它将识别在这些疾病状态下可以逆转这些改变的中枢神经系统药物谱的策略和药物；3)它将导致一种新的策略，即操纵P-gp活性，用于开发针对中枢神经系统疾病的药物和开发具有较少中枢神经系统副作用的药物。退伍军人事务部表格10-1313-2退伍军人事务部表格10-1313包装第2页1990年6月(R)

DESCRIPTION (provided by applicant): SUMMARY DESCRIPTION OF PROGRAM SUMMARY DESCRIPTION OF PROJECT RESEARCH AND DEVELOPMENT PROGRAM PRINCIPAL INVESTIGATOR(S) Banks, William A TITLE OF PROGRAM PROJECT (Not to exceed 72 character spaces) Control of Drug Delivery to the CNS: Modulating P-glycoprotein Activity KEYWORDS (MeSH terms only; minimum three) Drug, blood-brain barrier, Brain, CNS, p-glycoprotein, innate immune system, cytokines, tumor necrosis factor-alpha, nitric oxide BRIEF STATEMENT OF RESEARCH OBJECTIVES (Do not use continuation sheets) A major problem in developing effective therapeutics for the brain is the blood-brain barrier (BBB), which excludes many drugs from the central nervous system (CNS). One major mechanism by which the BBB excludes drugs is through P- glycorprotein (P-gp). P-gp is a brain-to-blood (efflux) pump located in the luminal side of the BBB that prevents its ligands from entering the CNS. P-gp has an affinity for an incredibly large number of clinically used drugs. Increasing P- gp activity further limits the access of its ligands to the CNS, thus making many CNS drugs ineffective, whereas decreasing P-gp activity allows more drug into the CNS, thus increasing effects. Our long-term goal is to learn how to control P-gp activity and so control the delivery of its ligands to the CNS. Recent in vitro work with brain endothelial cells has demonstrated a cascade of events that regulate P-gp activity. P-gp at the brain endothelial cell is inhibited by lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNF). These sequentially stimulate endothelin-1 (ET-1), which acts through its B receptor (ETRB) to increase nitric oxide synthase (NOS) activity that acts within minutes to decrease P- gp activity for min-h: LPS -> TNF -> ET-1 (ETRB) ->NOS -> decreased P-gp activity. This pathway also stimulates NFkB through the ET-1 receptors ETRA and ETRB to increase expression of P-gp, producing within hours a long-term stimulation of P-gp: TNF -> ET-1 (ETRA/ETRB) -> NOS -> NFkB -> mRNA (P-gp) -> increased P-gp activity. Our goal is to determine whether these mechanisms are operational in vivo. Our working hypothesis is: P-gp activity is regulated in vivo by the sequential activation of TNF, ET-1, and NOS. Our specific aims are: SA 1: To determine in vivo in mice the short- and long-term effects of TNF on P-gp. SA2 : To determine in vivo in mice the role of ET-1 on LPS-induced change in P-gp. SA 3: To determine in vivo in mice the short- and long-term effects of NOS on P-gp. Potential Impact on Veteran's Health Care: If all or part of this cascade is active in vivo, then P-gp activity is likely modified in a host of diseases that would result in altered CNS drug activities. These diseases would include not only bacterial sepsis, but diseases such as rheumatoid arthritis, diabetes, stroke, CNS cancers, and even obesity and Alzheimer's disease in which proinflammatory and neuroinflammatory conditions exist. The proposed work will have 3 major impacts on health care: 1) it will help to identify drugs and diseases in which a modified P-gp activity results in altered CNS drug profiles; 2) it will identify stategies and agents which can reverse those altered CNS drug profiles in those disease states; 3) it will lead to a new strategy, that of manipulation of P-gp activity, in the development of drugs both for targeting CNS diseases and for developing drugs with fewer CNS side effects. VA FORM 10-1313-2 Page 2 of VA Form 10-1313 package JUN 1990(R)