Mechanisms of Nitric Oxide Mediated Cell Injury

描述：最近的研究表明，各种炎症性疾病， 与诱导型一氧化氮的上调有关 合成酶（iNOS）和随之而来的自由基的产生增加 一氧化氮（NO）。我们的长期目标是更好地了解氧化 和亚硝化化学从高输出的NO可能有助于 与炎症相关的组织功能障碍和/或损伤。更 具体而言，尚未确定其运作程度 由NO介导的S-亚硝化反应引起的改变（添加 NO+基团的巯基残基）可能有助于细胞抑制。初步 我们实验室的研究表明， 通过激活iNOS抑制细胞增殖，抑制线粒体 呼吸，诱导谷胱甘肽代谢的改变，并介导 细胞蛋白质和肽的S-亚硝化。这个项目的总体目标是 建议是确定如何反应性氮氧化物物种来自NO 可能有助于细胞停滞，并获得更好的理解， 与NO相关的细胞内亚硝化化学。我们提出， S-亚硝化反应有助于抑制细胞呼吸， 增殖与NO产生增加有关。具体 本项目的目的是1）建立反应性之间的因果关系 氮物种和NO介导的细胞停滞; 2）研究的机制， 细胞介导的S-亚硝基硫醇的形成; 3）确定细胞途径 的S-亚硝基硫醇分解; 4）表征的机制， 活性氮氧化物物质抑制细胞呼吸，并检查其 与细胞停滞的关系。为了实现这些具体目标，我们将重点关注 一种主要的生物系统，一种组成性地 表达人类形式的诱导型一氧化氮合酶。我们还将 检查细胞内S-亚硝基硫醇代谢的动力学和平衡 使用新开发的色谱，荧光分光光度计和 化学发光技术这些研究可能对以下方面具有重要意义： 细胞增殖和毒性，如在巨噬细胞诱导的 与宿主防御机制相关的细胞停滞， 血管生成过程中的血管细胞，以及在环境和医疗 肺暴露于NO。

DESCRIPTION: Recent studies indicate that a variety of inflammatory disorders are associated with the up-regulation of the inducible form of nitric oxide synthase (iNOS) and the consequential enhanced production of the free radical nitric oxide (NO). Our long-term goal is to better understand how the oxidative and nitrosative chemistry emanating from high output of NO may contribute to the tissue dysfunction and/or injury associated with inflammation. More specifically, it has not yet been established to what extent functional alterations caused by NO-mediated S-nitrosation reactions (the addition of an NO+ group to a thiol residue) might contribute to cytostasis. Preliminary studies in our laboratory demonstrate that the intracellular production of NO via activation of iNOS inhibits cell proliferation, inhibits mitochondrial respiration, induces alteration in glutathione metabolism, and mediates the S-nitrosation of cellular proteins and peptides. The overall goal of this proposal is to determine how reactive nitrogen oxide species derived from NO may contribute to cytostasis and to obtain a better understanding of the intracellular nitrosative chemistry associated with NO. We propose that S-nitrosation reactions contribute to the inhibition of cell respiration and proliferation that is associated with increased NO production. The specific aims of this project are 1) to establish a causative link between reactive nitrogen species and NO-mediated cytostasis; 2) to examine the mechanisms of cell mediated formation of S-nitrosothiols; 3) to define the cellular pathways of S-nitrosothiol decomposition; 4) to characterize the mechanisms by which reactive nitrogen oxide species inhibit cell respiration and to examine their relationship with cytostasis. To address these specific aims, we will focus on one major biological system, a murine fibroblast cell line that constitutively expresses the human form of the inducible nitric oxide synthase. We will also examine the kinetics and equilibria of intracellular S-nitrosothiol metabolism using newly developed chromatographic, spectrofluorometric and chemiluminescence techniques. These studies may have important implications for cellular proliferation and toxicity, such as observed in macrophage-induced cytostasis associated with host defense mechanisms, in the proliferation of vascular cells during angiogenesis, and in environmental as well as medical pulmonary exposure to NO.