P53, APOPTOSIS AND CHRONIC RHEUMATOID ARTHRITIS

这是一个应用程序，以测试一个新的假说的发病机制 类风湿性关节炎 我们建议研究 滑膜增生性扩张中的p53突变作为 炎症的后果。活性氧（ROS）和 一氧化氮（NO），目前在发炎的关节，是已知的， 我们提出的凋亡的活性诱导剂， 在该部位由生长因子诱导的组织扩张。 基于 关于癌前皮肤病变的研究，我们提出， p53可以作为长期暴露于 ROS和NO的诱变作用，并且进一步地，这种突变 产生对由ROS-和/或NO-引起细胞凋亡的抵抗状态， 诱导滑膜细胞DNA损伤。这种对细胞凋亡的抵抗 导致细胞大量聚集，尽管适度增殖 这种扩张可以发生在细胞凋亡的事实上， 野生型细胞在网站上。 随着时间的推移，血管翳 会导致关节损伤 因此，虽然我们认为类风湿性关节炎 关节炎是一种主要的免疫性疾病，我们认为， 非免疫学事件（如p53介导的 凋亡反应）可以对进展做出重大贡献 疾病。 我们建议从三个方面来检验这个模型。 第一、 我们计划研究p53在ROS诱导的细胞凋亡中的作用， 和相关细胞类型（巨噬细胞、成纤维细胞样 滑膜细胞）和相关细胞。这将在培养中完成， 通过使用温度敏感的p53突变体， 条件性p53在多种细胞中发挥作用。 因为p53是必需的 在许多细胞中用于诱导细胞凋亡， 破坏剂，我们预计它将在这里发挥作用， 好. 同时，我们将检查类风湿关节的组织 和对照p53突变的存在，两者均通过 免疫组织化学和分子方法。 这些方法 已经被开发用于癌症研究，但还没有被 应用于炎症性疾病。 最后，我们将评估 p53基因缺失小鼠的细胞凋亡和疾病进展 通过有针对性的破坏，我们将诱导联合 通过免疫学手段。这些研究将 形成严格追求这一模式或调整后的模式的基础。 虽然这些研究的风险很高，但完全可行 如果成功，他们将有重要的 对我们了解类风湿性关节炎的影响。

This is an application to test a novel hypothesis on the pathogenesis of rheumatoid arthritis. We propose to examine the possible role of p53 mutations in hyperplastic expansion of the synovium as a consequence of inflammation. Reactive oxygen species (ROS) and nitric oxide (NO), present in the inflamed joint, are known to be active inducers of apoptosis, which we propose normally offsets tissue expansion induced by growth factors at the site. Based on studies on precancerous skin lesions, we propose that mutations in p53 can occur as a consequence of long term exposure to the mutagenic action of ROS and NO, and further, that such mutations produce a state of resistance to apoptosis cause by ROS-and/or NO- induced DNA damage of synoviocytes. This resistance to apoptosis results in massive accumulation of cells despite modest proliferation of the tissue, and this expansion can occur in the fact of apoptosis of wild-type cells at the site. With time, the resulting pannus contributes to joint damage. Thus, while we consider rheumatoid arthritis a predominantly immunologic disease, we believe that nonimmunologic events (such as somatic defects in p53-mediated apoptotic response) can make a major contribution to the progression of the disease. We propose to test this model in three ways. First, we plan to examine the role of p53 in apoptosis inducted by ROS and NO in the relevant cell types (macrophages, fibroblast-like synovial cells) and related cells. This will be done in culture, through the use of temperature-sensitive p53 mutants that permit conditional p53 function in a variety of cells. Since p53 is required in many cells for the induction of apoptosis following DNA damaging agents, we expect that it will have such a role here as well. Concurrently, we will examine tissue from rheumatoid joints and controls for the presence of mutation in p53, both by immunohistochemistry and by molecular approaches. These methods have been developed for use in cancer research but have not yet been applied to inflammatory disease. Finally, we will assess the role of p53 in apoptosis and disease progression in mice lacking this gene through targetted disruption, in which we will induce joint inflammation by immunologic means. Together, these studies will form the basis for rigorous pursuit of this model or adjusted models. Although the proposed studies are high risk, they are fully feasible in a three year period, and if successful they will have important consequences for our understanding of rheumatoid arthritis.