Role of DNA Glycosylase OGG1 in Oxidative Stress-Induced Innate Inflammation

氧化性DNA碱基损伤与炎症过程有关，但在炎症过程中存在重大缺陷。 了解他们的疾病病因尽管相当大的努力。最丰富的DNA碱基损伤，8- 氧代鸟嘌呤（8-oxoG）与炎症，各种年龄相关疾病和衰老过程有关。是 通过8-oxoG DNA糖基化酶（0 GG 1）和DNA碱基切除修复（BER）从DNA上切除 通路出乎意料的是，Oggi敲除小鼠中的超生理8-oxoG水平没有显示出主要的 事实上，它们增加了对炎症的抵抗力。DNA中8-oxoG水平的增加是 气道氧化暴露后的最早事件;然而，其在触发炎症中的作用是 怀疑但不理解。我们有了意想不到的发现，表明1）OGGI消耗从 氧化暴露前的气道上皮显著降低先天性炎症反应; 2） OGG 1结合其修复产物，游离8-oxoG碱基; 3）OGG 1 <$8-oxoG复合物具有鸟嘌呤核苷酸 交换因子活性，4）增加活化的小Ras GTP酶的水平，5）导致 NF-κ B/RelA.项目3试图建立一个新的范式，其中0 GG 1启动的DNA BER在病因学上是 与氧化应激诱导的促炎基因表达和炎症有关。会来做这项工作 本论文的主要目的是：1）确定OGGI启动的DNA BER在炎症细胞中的作用 目的2）阐明OGGI在肺内氧化应激暴露后的累积中的作用;目的2）阐明OGGI在肺内氧化应激暴露后的累积中的作用。 NF-kB/RelA通路;和目的3）鉴定触发促炎性的OGGI诱导的信号通路 基因表达和炎症。我们的假设将使用敲除/转基因技术进行检验。 小鼠和细胞系以及诸如基于siRNA的基因切除等最先进的分子技术 表达，实时PCR，共聚焦显微镜，和细胞因子/趋化因子和RNA阵列。这些研究 应该是第一个建立OGGI的作用，并确定其新的信号通路，促进先天性 肺部炎症由于OGG 1对8-oxoG的修复是连续的，这些研究的结果也可能 有助于了解过敏性哮喘、慢性阻塞性肺病 气道重塑和肺部恶性肿瘤;每一种都对个人、家庭、健康 护理系统和整个社会，在美国和世界各地。我们令人信服的初步数据， 在这个POI的优秀合作，UTMB的优秀资源和智力环境， 我们是唯一适合做这项工作的人

Oxidative DNA base damage is linked to inflammatory processes, but there are major shortcomings in understanding their disease etiology despite considerable efforts. The most abundant DNA base lesion, 8- oxoguanine (8-oxoG) is linked to inflammation, various age-associated diseases, and aging processes. It is excised from DNA by the 8-oxoG DNA glycosylase (0GG1) and the DNA base excision repair (BER) pathway. Unexpectedly, supraphysiological 8-oxoG levels in Oggi knockout mice do not show major pathologies; in fact, they have increased resistance to inflammation. An increase in 8-oxoG levels in DNA is the earliest event upon oxidative exposure of airways; however, its role in triggering inflammation is suspected but not understood. We have made unexpected discoveries showing that 1) OGGI depletion from the airway epithelium before oxidative exposure significantly decreased innate inflammatory responses; 2) 0GG1 binds its repair product, free 8-oxoG base; 3) the OGG1¿8-oxoG complex has a guanine nucleotide exchange factor activity that 4) increases levels of activated small Ras GTPases and 5) leads to activation of NF-KB/RelA. Proiect 3 seeks to establish a novel paradigm in which 0GG1-initiated DNA BER is etiologically linked to oxidative stress-induced proinflammatory gene expression and inflammation. This will be done by pursuing three Specific Aims, to: Aim 1) establish the role of OGGI-initiated DNA BER in inflammatory cell accumulation after oxidative stress exposure in the lungs; Aim 2) elucidate the role of OGGI in activation of the NF-kB/RelA pathway; and Aim 3) identify the OGGI-induced signaling pathway(s) that trigger proinflammatory gene expression and inflammation. Our hypotheses will be tested using knock-out/transgenic mice and cell lines and such state-of-the-art molecular techniques as siRNA-based ablation of gene expression, real-time PCR, confocal microscopy, and cytokine/chemokine and RNA arrays. These studies should be the first to establish the role of OGGI and identify its novel signaling pathways that facilitate innate lung inflammation. As repair by 8-oxoG by OGG1 is continuous, the results from these studies may also shed light on understanding chronic inflammation in allergic asthma, chronic obstructive pulmonary disease, airway remodeling and lung malignancies; each poses a significant burden on individuals, families, health care systems and the entire society, here in the US and worldwide. Our compelling preliminary data, excellent collaborations in this POI, and UTMB's outstanding resources and intellectual environment make us uniquely suited to do this work.