GENETIC MECHANISMS OF DIDEOXYNUCLEOSIDE INDUCED TOXICITY

双脱氧核苷诱导毒性的遗传机制

• 批准号: 3148330
• 负责人: JEAN-PIERRE C SOMMADOSSI
• 金额: $ 16.91万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3148330
• 关键词: 2'3' dideoxynucleoside; anemia; antiAIDS agent; genetic regulation; human immunodeficiency virus; human tissue; peripheral nervous system disorders; toxicology

DESCRIPTION: (Adapted from the author's abstract.) The primary goal of the proposed research is to investigate the molecular mechanism(s) of toxicities consisting of myelosuppression (anemia) and peripheral neuropathy, as a result of the effects of 2',3'-dideoxynucleosides (ddN's) on the expression of specific genes. In completing the two major aims of their project, the Investigator expects that the basic cellular and molecular studies will provide a rational basis for future structural studies leading to the design of second and third generation, highly specific nucleoside analogs active against the human immunodeficiency virus (HIV). Aim #1: the elucidation of the mechanism(s) responsible for the anemia induced by AZT, by way of inhibition by AZT and AMT of genes that regulate hemoglobin synthesis. AMT is a newly-identified metabolite of AZT which as been demonstrated by these investigators to be highly toxic to human bone marrow progenitor cells. In the proposed research, the researchers will evaluate the mechanism(s) involved in AMT toxicity for human erythroid cells and its role in AZT-induced anemia observed in patients. They will assess the effects of AZT and AMT on the expression of genes that regulate globin synthesis and heme synthesis (including 5-aminolevulinate synthase, 5-aminolevulinate dehydrase, and phosphobilinogen deaminase) as compared to constitutively-expressed genes. The examination of novel ddN's currently being evaluated in Phase I trials-- such as 3'-fluorothymidine, shown to be very toxic in erythroid progenitor cells--will permit the investigators to evaluate structural factors potentially important for inhibition of globin and "heme" gene expression. The influence of hemin on the expression of genes regulating the hemoglobin synthesis and affected by AZT and AMT will be examined in an attempt to elucidate the mechanism(s) responsible for hemin protective effects of AZT cytotoxicity in erythroid cells. Elucidation of inhibition of globin gene transcription by AZT will be ascertained in evaluating effects of AZT on the activity and amount of specific erythroid nuclear proteins, such as NF-E1 and NF-E2. AIM 2: the examination of toxicity with the elucidation of cellular and molecular mechanism(s) of dideoxycytodine (ddC), dideoxyinosine (ddI), and 2',3'-didhydro-2',3'-dideoxythymidine (d4T) as related to their effects on peripheral neurons. Using a PC-12 cell as a model, the researchers will study the effects of ddC, ddI, and d4T on neurite outgrowth and survival, including the effects of the ddN's on initiation of neurite outgrowth, priming, on neurite degeneration and regeneration, and on biological markers. They will: discriminate the effects of ddN's on electrophysiological function in the soma, neurite, and growth cones of PC-12 cells and multinucleated cells; elucidate the mechanism(s) of toxicity by evaluating effects of ddN's on mitochondrial DNA synthesis and neural-specific protein synthesis; and study the effects of ddN's on the expression of genes that regulate neurofilaments and microtubule-associated proteins.

描述：（改编自作者的摘要。）主要目标 拟议的研究是调查分子机制 毒性包括骨髓抑制（贫血）和外周血 2',3'-双脱氧核苷 (ddN's) 作用导致的神经病 关于特定基因的表达。 在完成两大目标的过程中 在他们的项目中，研究人员预计基本的蜂窝和 分子研究将为未来的结构提供合理的基础 研究导致了第二代和第三代的设计，高度 具有抗人类免疫缺陷活性的特定核苷类似物 病毒（艾滋病毒）。 目标#1：阐明负责的机制 AZT 通过抑制 AZT 和 AMT 基因引起的贫血 调节血红蛋白的合成。 AMT是一种新发现的代谢物 这些研究人员证明 AZT 具有高度的 对人类骨髓祖细胞有毒。 在拟议的研究中， 研究人员将评估 AMT 毒性的机制 人红系细胞及其在 AZT 诱导的贫血中的作用 患者。 他们将评估 AZT 和 AMT 对表达的影响 调节珠蛋白合成和血红素合成的基因（包括 5-氨基乙酰丙酸合酶、5-氨基乙酰丙酸脱水酶，和 磷酸胆原脱氨酶）与组成型表达的基因相比。 目前正在第一阶段评估新型 ddN 的检查 试验——例如 3'-氟胸苷，显示对红系细胞毒性很大 祖细胞——将允许研究人员评估结构 对抑制球蛋白和“血红素”基因具有潜在重要作用的因素 表达。 氯高铁血红素对调控基因表达的影响 血红蛋白合成及其受 AZT 和 AMT 的影响将在 试图阐明负责血红素保护作用的机制 AZT 细胞毒性对红系细胞的影响。 抑制作用的阐明 AZT 对珠蛋白基因转录的影响将在评估中确定 AZT对特定红细胞核活性和数量的影响 蛋白质，例如 NF-E1 和 NF-E2。 目的2：毒性检查 阐明细胞和分子机制 双脱氧胞嘧啶 (ddC)、双脱氧肌苷 (ddI) 和 2',3'-二氢-2',3'-二脱氧胸苷 (d4T) 与其对 周围神经元。 使用 PC-12 细胞作为模型，研究人员将 研究 ddC、ddI 和 d4T 对神经突生长和存活的影响， 包括 ddN 对神经突生长起始的影响， 启动、神经突变性和再生以及生物 标记。 他们将： 区分 ddN 对 体细胞、神经突和生长锥的电生理功能 PC-12细胞和多核细胞；阐明其机制 通过评估 ddN 对线粒体 DNA 合成的影响来确定毒性 神经特异性蛋白质合成；并研究 ddN 对 调节神经丝的基因的表达和 微管相关蛋白。