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ADAPTIVE RESISTANCE TO NITRIC OXIDE

对一氧化氮的适应性抵抗

基本信息

批准号：
7093262
负责人：
Bruce F. Demple
金额：
$ 3.65万
依托单位：
HARVARD SCHOOL OF PUBLIC HEALTH
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-09-17 至 2006-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7093262
关键词：
biological signal transduction cell type cytotoxicity enzyme mechanism fibroblasts gene targeting genetic regulation genetic transcription genetically modified animals heme oxygenase laboratory mouse messenger RNA mitogen activated protein kinase neoplasm /cancer genetics nitric oxide

项目摘要

Nitric oxide (NO) is produced in mammalian cells by several NO synthases, including an inducible form with high output during inflammation. Since NO may contribute to carcinogenesis and age- related neurodegeneration, we wish to understand how mammalian cells counteract NO toxicity. We have identified a group of 12 proteins induced in normal human fibroblasts by exposure to subtoxic levels of NO, including the antioxidant enzyme heme oxygenase 1 (HO-1). We have shown that the induction of HO-1 mRNA occurs via NO-dependent changes in its stability. We will explore the mechanism of this regulation and try to define the signal transduction pathway for post-transcriptional control of HO-1. Other genes (e.g., MAP kinase phosphatase MKP-1/CL100) are controlled transcriptionally, and we will test specific transcription regulators for their roles in this expression. We have identified an adaptive resistance to NO in the rodent motor neurons: cells exposed to low-level NO that induces HO-1 become resistant to much higher (usually cytotoxic) levels of NO. We will characterize this response in various cell types by identifying NO-inducible genes and determining their roles in protection against NO-mediated toxicity. HO-1 knockout mice will allow us to define the defensive role of HO-1 in fibroblasts, neurons, and other tissues. This project involves parallel efforts to follow biochemical markers of nitric oxide damage (e.g., nitrotyrosine), to use genetics to establish the role of HO-1 in inducible resistance to NO, to elucidate regulatory and signal transduction pathways, and to identify and clone novel defense genes for NO resistance.

在哺乳动物细胞中，一氧化氮（NO）是由几种NO合成酶产生的，包括炎症期间高输出的诱导形式。由于NO可能有助于致癌和年龄相关的神经退行性变，我们希望了解哺乳动物细胞如何抵抗NO毒性。我们鉴定了暴露于亚毒性水平NO的正常人成纤维细胞中诱导的一组12种蛋白质，包括抗氧化酶血红素加氧酶1 （HO-1）。我们已经证明，HO-1 mRNA的诱导是通过no依赖性的稳定性变化发生的。我们将探索这种调控的机制，并试图确定HO-1转录后调控的信号转导途径。其他基因（如MAP激酶磷酸酶MKP-1/CL100）受转录控制，我们将测试特定的转录调节因子在这种表达中的作用。我们已经确定了啮齿动物运动神经元对NO的适应性抗性：暴露于诱导HO-1的低水平NO的细胞对更高（通常是细胞毒性）水平的NO产生抗性。我们将通过鉴定no诱导基因并确定其在no介导的毒性保护中的作用来表征各种细胞类型中的这种反应。HO-1敲除小鼠将使我们能够确定HO-1在成纤维细胞、神经元和其他组织中的防御作用。该项目包括跟踪一氧化氮损伤的生化标记（如硝基酪氨酸），利用遗传学确定HO-1在诱导抵抗NO中的作用，阐明调控和信号转导途径，并鉴定和克隆新的NO抗性防御基因。