TOXICITY OF ANTI-AIDS AGENTS ON THE BONE MARROW

抗艾滋病药物对骨髓的毒性

基本信息

批准号：
2220303
负责人：
JEAN-PIERRE C SOMMADOSSI
金额：
$ 22.49万
依托单位：
UNIVERSITY OF ALABAMA AT BIRMINGHAM
依托单位国家：
美国
项目类别：
财政年份：
1994
资助国家：
美国
起止时间：
1994-01-01 至 1996-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2220303
关键词：
antiAIDS agent bone marrow cellular pathology cytochrome P450 drug adverse effect drug interactions enzyme inhibitors enzyme mechanism gene expression liver cells nucleoside analog purine /pyrimidine metabolism tissue /cell culture uridine monophosphate zidovudine

项目摘要

DESCRIPTION (adapted from the Abstract): The objectives of this competing renewal application are to continue and extend ongoing studies on the mechanism(s) by which pyrimidine nucleoside analogs active against the human immunodeficiency virus (HIV), such as 3'azido-3'- deoxythymidine and congeners, exert toxicity on bone marrow cells and other toxicity sites. The elucidation of these mechanism(s) may permit the development of a combination therapy with modulating agents that protect or reverse host toxicity without impairment of anti-HIV activity of the drug under scrutiny. This project includes two major aims: (1) the description of the biochemical and molecular mechanism(s) responsible for the effects of AZT and its metabolite, 3'-amino-3'- deoxythymidine (AMT) in human bone marrow cells; and (2) the detailed characterization of the enzymatic reduction of AZT to AMT in human hepatocytes with the evaluation of potential drug-drug interactions through the cytochrome P450 pathway. The Principal Investigator and his associates will define the mechanism(s) by which these 2',3'- dideoxynucleosides (ddN's) affect directly uridine-5'-monophosphate (UMP) synthase and indirectly other enzymes in the pathway for de novo pyrimidine biosynthesis. They will delineate the effects of these ddN's using human bone marrow liquid cultures in suspension and cells deficient in synthase (orotic aciduria cells) and with transformed cells with amplified enzyme activity; they will examine the potential alterations in the UMP synthase protein with discrimination of its two activities (i.e., orotate phosphoribosyltransferase [OPRT] and orotidine-5'-monophosphate decarboxylsse [OFC]). The analysis of mRNA steady-state levels of either gene affected by AZT and other analogs with the evaluation of the functionality of the RNA molecules transcribed by the affected gene will permit the determination of critical factors potentially important for effects of AZT on UMP synthase. Using human cultured muscle cells the researchers will ascertain whether inhibition of UMP synthase, as compared to the effects on mitochondrial DNA synthesis, plays a role in AZT-induced myopathies. With regard to the second aim, the researchers will use specific monoclonal antibodies and specific inhibitors to elucidate the cytochrome P450 isoenzyme responsible for conversion of 3'-azido-ddN's to 3'-amino-ddN's together with the role of NADPH P450 reductase in that reaction. They will assess the presence of this metabolism at target sites (lymphocytes) and toxic sites (bone marrow and muscle cells) with possible formation of a reactive intermediate an/or free radicals, and will determine the effects of cytochrome P450 inducers or inhibitors on AMT formation in human hepatocytes to ascertain whether AZT pharmacodynamic properties may be altered under these conditions.

描述（改编自摘要）：本次会议的目标竞争性更新申请将继续并扩展正在进行的研究嘧啶核苷类似物的作用机制人类免疫缺陷病毒 (HIV)，例如 3'azido-3'- 脱氧胸苷和同系物对骨髓细胞产生毒性其他毒性部位。这些机制的阐明可能允许开发具有调节剂的联合疗法保护或逆转宿主毒性而不损害抗 HIV 活性正在接受审查的药物。该项目包括两个主要目标：（1）生化和分子机制的描述负责 AZT 及其代谢物 3'-amino-3'- 的作用人骨髓细胞中的脱氧胸苷（AMT）； (2) 详细人体内 AZT 酶促还原为 AMT 的表征肝细胞与潜在药物相互作用的评估通过细胞色素P450途径。首席研究员和他的同事将定义这些 2',3'- 的机制双脱氧核苷 (ddN's) 直接影响尿苷-5'-单磷酸 (UMP)合酶和从头途径中间接的其他酶嘧啶生物合成。他们将描述这些 ddN 的影响使用人骨髓悬浮液和细胞液体培养物合酶缺陷（乳清酸尿症细胞）和转化细胞酶活性增强；他们将考察潜力 UMP 合酶蛋白的改变及其两个的区别活性（即乳清酸磷酸核糖转移酶 [OPRT] 和乳清苷-5'-单磷酸脱羧酶[OFC]）。 mRNA分析受 AZT 和其他类似物影响的任一基因的稳态水平评估 RNA 分子的功能由受影响的基因转录将允许确定 AZT 对 UMP 影响的潜在重要关键因素合酶。研究人员将利用人类培养的肌肉细胞确定是否抑制UMP合酶，并与效果进行比较线粒体 DNA 合成，在 AZT 诱导的肌病中发挥作用。对于第二个目标，研究人员将使用特定的单克隆抗体和特异性抑制剂来阐明细胞色素 P450 同工酶负责 3'-叠氮基-ddN 的转化到 3'-氨基-ddN 以及 NADPH P450 还原酶的作用反应。他们将评估目标代谢是否存在部位（淋巴细胞）和毒性部位（骨髓和肌肉细胞）可能形成反应中间体和/或自由基，以及将确定细胞色素 P450 诱导剂或抑制剂对人肝细胞中 AMT 的形成以确定 AZT 是否在这些条件下，药效学特性可能会改变。