DIDEOXYNUCLEOSIDE TRANSPORT IN THE BLOOD/BRAIN BARRIER

血/脑屏障中的双脱氧核苷转运

基本信息

批准号：
2274664
负责人：
DONALD W MILLER
金额：
$ 10.82万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-07-01 至 1999-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2274664
关键词：
2'3' dideoxycytidine 2'3' dideoxyinosine 2'3' dideoxynucleoside biological transport blood brain barrier chemical structure function pharmacokinetics tissue /cell culture transport proteins vascular endothelium zidovudine

项目摘要

Human immunodeficiency virus (HIV) infections within the brain produce serious neurological complications. It is estimated that at least 30% of all adults with AIDS and 50% of all children with AIDS will suffer central nervous system disorders related to HIV infection within the brain. Treatment of the neurological complications related to AIDS is difficult as anti-viral dideoxynucleosides commonly used in the treatment of AIDS do not readily cross the blood-brain barrier (BBB). The presence of carrier systems for 3'-azido-2',3'-dideoxythymidine (AZT) and related dideoxynucleosides in the blood-cerebral spinal fluid barrier have been well documented. However, few studies have critically evaluated the presence of dideoxynucleoside carriers within the brain microvessel endothelial cells that form the BBB. In the present proposal, carrier systems mediating the transport of dideoxynucleosides both into and out of brain microvessel endothelial cells will be examines. The working hypothesis for the proposed studies are that specific, distinct carrier systems exist on the plasma membrane of the brain microvessel endothelial cells that control the uptake and efflux of dideoxynucleosides. Dideoxynucleoside carriers on the BBB will be identified and characterized using primary cultured bovine brain microvessel endothelial cells (BBMEC). To examine uptake carriers, the accumulation of a series of radiolabeled dideoxynucleosides (AZT, dideoxyinosine, dideoxycytosine, and dideoxythymidine) in BBMEC monolayers will be examined to determine: 1) the uptake rates for each compound, 2) the saturability of uptake and structural features required for nucleoside interactions with the carrier, 3) the energy-dependency of uptake and 4) the localization of carriers on the lumenal (blood side) and ablumenal (brain side) plasma membrane. Efflux of the same series of radiolabeled dideoxynucleosides out of BBMEC monolayers will be examined to determine: 1) the susceptibility of dideoxynucleoside efflux to known nucleoside carrier inhibitors, 2) important structural features required for dideoxynucleoside interactions with the efflux carrier, and 3) the location and distribution of dideoxynucleoside carriers on the lumenal and ablumenal side of BBMEC monolayers. These studies will critically examine the cellular mechanisms controlling the passage of dideoxynucleosides across the BBB. By characterizing uptake and efflux carriers with regard to their specificity of inhibitors and their energy requirements, comparisons can be made to nucleoside transport systems in other cells. The information obtained in these studies can also be used to improve the efficacy of both current and future anti-viral nucleosides in the treatment of neurological disorders associated with AIDS.

大脑中的人类免疫缺陷病毒（HIV）感染产生严重的神经系统并发症。据估计，至少30％所有患有艾滋病的成年人和所有艾滋病儿童中有50％将遭受中心与大脑内的艾滋病毒感染有关的神经系统疾病。治疗与艾滋病有关的神经系统并发症很难通常用于治疗艾滋病治疗的抗病毒二氧基核苷不容易越过血脑屏障（BBB）。载体的存在 3'-azido-2'，3'-二氧甲烷苷（AZT）的系统和相关的系统血脑脊髓屏障中的二乙氧基核苷已经是据记录。但是，很少有研究对大脑微血管内存在二乙酰核苷载体形成BBB的内皮细胞。在本提案中，承运人介导二乙氧基核苷的运输的系统将检查脑微血管内皮细胞。工作提出的研究的假设是特定的，不同的载体系统存在于大脑微血管内皮的质膜上控制二乙氧基核苷的摄取和外排的细胞。 BBB上的二乙氧基核苷载体将被识别并表征使用原代培养的牛脑微血管内皮细胞（BBMEC）。为了检查摄取载体，一系列放射线标记的积累二氧基核苷（AZT，二氧基氨酸，二氧基胞霉素和将检查BBMEC单层中的二乙酰噻天胺定）确定：1）每种化合物的摄取率，2）摄取的饱和性和核苷与载体相互作用所需的结构特征， 3）摄取的能量依赖性和4）载体的定位腔（血侧）和空白（脑侧）质膜。同一系列放射性标记的二氧核苷的外排从BBMEC出发将检查单层以确定：1）二乙氧基核苷对已知核苷载体抑制剂的外排，2）二乙氧基核苷相互作用所需的重要结构特征使用外排载体，3） BBMEC的流体和空白侧的二乙氧基核苷载体单层。这些研究将严格检查细胞机制控制二乙氧基核苷在BBB中的通过。经过表征摄取和外排载体的特异性抑制剂及其能量需求，可以进行比较其他细胞中的核苷转运系统。获得的信息这些研究也可用于提高当前和未来的抗病毒核苷在神经系统疾病的治疗中与艾滋病相关。