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：（根据作者的摘要进行了改编。） 拟议的研究是研究分子机制 包括脊髓抑制（贫血）和周围的毒性 神经病变，由于2'，3'-二氧基核苷（DDN）的影响 关于特定基因的表达。 完成两个主要目标 他们的项目，调查人员希望基本的细胞和 分子研究将为将来的结构提供合理的基础 研究导致第二代和第三代的设计，高度 特定的核苷类似物对人类免疫缺陷有效 病毒（HIV）。 目的＃1：阐明负责机制 AZT诱导的贫血，通过AZT和AMT的抑制作用 调节血红蛋白合成。 AMT是一种新识别的代谢物 这些研究者证明的AZT高度高度 对人骨髓祖细胞有毒。 在拟议的研究中 研究人员将评估涉及AMT毒性的机制 对于人类红细胞细胞及其在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 调节球蛋白合成和血红素合成的基因（包括 5-氨基乙酸合酶，5-氨基乙酸脱水酶和 与组成型表达的基因相比，磷脂蛋白原脱氨酶）。 目前在第一阶段评估新型DDN的研究 试验 - 例如3'-氟噻嗪，在红斑中非常有毒 祖细胞 - 将允许研究人员评估结构 因素对于抑制球蛋白和“血红素”基因可能很重要 表达。 Hemin对调节基因表达的影响 血红蛋白合成并受AZT和AMT的影响 试图阐明负责Hemin保护的机制 AZT细胞毒性在红细胞细胞中的影响。 阐明抑制作用 在评估时将确定AZT的Globin基因转录 AZT对特定红细胞核活性和量的影响 蛋白质，例如NF-E1和NF-E2。 目标2：毒性检查 随着细胞和分子机制的阐明 Dideoxytodine（DDC），甲氧基氨酸（DDI）和 2'，3'didhydro-2'，3'-二氧甲氧基（D4T）与它们对它们的影响有关 周围神经元。 使用PC-12单元作为模型，研究人员将 研究DDC，DDI和D4T对神经突生长和生存的影响， 包括DDN对神经突生长的影响， 启动，神经突变性和再生以及生物学 标记。 他们将：区分DDN的影响 躯体，神经突和生长锥的电生理功能 PC-12细胞和多核细胞；阐明机制 通过评估DDN对线粒体DNA合成和 神经特异性蛋白质合成；并研究DDN对 调节神经丝和的基因表达 微管相关蛋白。