Linkage of the oxidant induced OGG1-DNA complex to airway inflammation and remodeling

呼吸道合胞病毒（RSV）是儿童下呼吸道感染（LRTI）的主要病原 国际吧RSV感染迅速产生活性氧（ROS），产生氧化DNA 8-oxoguanine（oxoG）是最丰富的一种。OxoG由8-氧代鸟嘌呤修复 DNA糖基化酶1（OGG 1）启动的DNA碱基切除修复途径（BER）。我们已经记录了ROS 瞬时失活OGG 1酶活性，导致OGG 1-DNA复合物的形成， 基因启动子和NFκ B结合基序的紧密接近。我们还证明了：1）OGG 1- oxoG处的DNA复合物增加体外NFκB结合; 2）OGG 1消耗或抑制OGG 1底物 高选择性小分子结合导致体内NFκ B依赖性基因表达降低。这些 数据表明OGG 1-oxoG复合物在先天免疫应答（IIR）中起关键作用。因此我们 最近发现OGG 1是RSV诱导的先天趋化因子、细胞因子和 白细胞介素构成IIR。与本P01的总体主题相关，我们还表明， OGG 1依赖性先天途径的激活导致控制肌动蛋白的基因网络的调节， 细胞骨架、细胞外基质、细胞粘附和细胞连接装置，导致气道重塑。 由于OGG 1对oxoG的高度特异性，这些结果指向一种新的范例，其中oxoG 作为一种表观遗传元件，在调节将IIR与气道连接的基因中发挥核心作用 重塑 该项目的首要假设是，RSV诱导的鸟嘌呤氧化为基因中的oxoG。 调节区是一种表观遗传修饰，通过NFκB将炎症与气道重塑联系起来 通路将在三个特定目的中检验这一假设：1）RSV诱导的促炎基因 表达和急性炎症依赖于ROS诱导的对DNA和OGG 1的氧化损伤; 2） 在IIR基因近端启动子区域的·oxoG处的OGG 1 DNA复合物作为NFκB的平台， OGG 1·DNA复合物与慢性氧化应激有关 与RSV致敏小鼠在过敏原攻击后的组织重塑有关。 为了实现这些目标，我们将利用小鼠模型，原代人小气道上皮细胞， 从RSV感染的婴儿中分离的鼻咽细胞，以及最先进的分子技术。 我们的研究有助于理解RSV-ROS诱导的OGG 1-DNA复合物在oxoG 在RSV背景下NF κ B驱动的IIR和气道重塑基因表达的表观遗传调节中 LRTI。这项工作还将推进使用可用的小分子药物治疗LRTI的创新方法。 OGG 1抑制剂。

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infections (LRTIs) in children worldwide. RSV infection rapidly generates reactive oxygen species (ROS) that produce oxidative DNA damage, with 8-oxoguanine (oxoG) being one of the most abundant. OxoG is repaired by the 8-oxoguanine DNA glycosylase1 (OGG1)-initiated DNA base excision repair pathway (BER). We have documented that ROS transiently inactivates OGG1 enzymatic activity, leading to formation of an OGG1-DNA complex in inducible gene promoters and in close proximity to NFκB-binding motifs. We have also demonstrated that: 1) OGG1- DNA complex at oxoG increases NFκB binding in vitro; and 2) OGG1 depletion or inhibition of OGG1 substrate binding by highly selective small molecules result in decrease NFκB-dependent gene expression in vivo. These data indicate that the OGG1-oxoG complex plays a key role in the innate immune response (IIR). As such, we recently found that OGG1 is required for RSV-induced expression of innate chemokines, cytokines, and interleukins constituting the IIR. Related to the overall theme of this P01, we have also shown that repeated activation of OGG1-dependent innate pathways resulted in modulation of gene networks controlling the actin cytoskeleton, extracellular matrix, cell adhesion, and cell junction apparatus, resulting in airway remodeling. Because of the high specificity of OGG1 for oxoG, these results point to a novel paradigm wherein oxoG functions as an epigenetic element that plays a central role in the regulation of genes that link IIR to airway remodeling. The overarching hypothesis of this project is that the RSV-induced oxidation of guanine to oxoG in gene regulatory regions is an epigenetic modification that links inflammation with airway remodeling via the NFκB pathway. This hypothesis will be tested in three Specific Aims: 1) RSV-induced pro-inflammatory gene expression and acute inflammation is dependent on ROS-induced oxidative damage to DNA and OGG1; 2) The OGG1 DNA complex at·oxoG in the proximal promoter regions of IIR genes serves as a platform for NFκB binding occupancy in response to RSV infection; 3) The OGG1·DNA complex links chronic oxidative stress with tissue remodeling in RSV-primed mice in response to allergen challenges. To achieve these aims, we will utilize mouse models, primary human small airway epithelial cells, nasopharyngeal cells isolated from RSV-infected infants, and well as state-of-the-art molecular technologies. Our studies contribute to the understanding of the role of the RSV-ROS-induced OGG1-DNA complex at oxoG in epigenetic regulation of NFkB-driven expression of IIR and airway remodeling genes in the context of RSV LRTI. This work will also advance innovative approaches for treatment of LRTI using available small-molecule inhibitors of OGG1.