Mechanistic insight into oxidative stress-mediated genome instability

氧化应激介导的基因组不稳定性的机制见解

• 批准号: 10570425
• 负责人: Elise Fouquerel
• 金额: $ 26.18万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10570425
• 关键词: Mechanistic; insight; into; oxidative; stress

Mechanistic insight into oxidative stress-mediated genome instability Summary: Genome instability is characterized by genetic alterations ranging from DNA base mutations to chromosome rearrangements that are drivers of many inherited human diseases, various types of cancer and premature ageing. Chromosome instability, especially, results from inaccurate chromosomal segregation caused by telomere and centromere dysfunction. Numerous epidemiologic studies have highlighted the central role of oxidative stress exposures in the occurrence of telomere and centromere dysfunction. Critically, however, the mechanisms underlying the dysfunction are not clearly understood. Oxidative stress results from an imbalance between the production of reactive oxygen species and cellular antioxidant defenses. It arises from endogenous sources as well as from environmental sources (mitochondria metabolism, UV light, air pollution, cigarette smoke). Its ubiquity highlights the importance of properly understanding its impacts on human health. A major impact of oxidative stress is the induction of oxidative DNA damage that are repaired by the base excision repair (BER) pathway in which poly(ADP-ribose) polymerases (PARPs) are major actors. PARP1 and PARP2 are responsible for the poly(ADP-ribosyl)ation, a post-translational modification of proteins that modulates the recruitment and interactions of their protein targets. The goals of this proposal are to (i) uncover the mechanisms of oxidative stress-mediated genome instability with a focus on its impact on telomeres and centromeres, two genomic loci crucial for genome stability and (ii) decipher the contribution of PARP enzymes in the protection of telomeric and centromeric DNA upon oxidative DNA damage. More specifically, we aim to evaluate the impact of chronic induction of oxidized DNA bases and BER single strand break intermediates on centromere and telomere integrity. We will also identify and assess the impact of poly(ADP-ribosyl)ation on centromeric and telomeric protein targets. To this end, we will leverage a unique and innovative chemoptogenetic tool that induces oxidative DNA damage locally at telomeres and at centromeres without impacting the rest of the genome. This will allow us to unequivocally link phenotypic changes and PARP dependent mechanisms to the telomeric or centromeric lesions. These projects will fill a long-standing gap of knowledge on how poly(ADP-ribosyl)ation orchestrates DNA repair at two crucial regions of the genome. They will also shed light on how oxidative stress, a ubiquitous factor of genome instability, can drive numerous human diseases. Ultimately, our work will contribute to the development of novel therapeutic strategies targeting specific regions of the genome and inform the rational design and use of the PARP inhibitors already widely used in cancer treatments.

氧化应激介导的基因组不稳定性的机制见解 概括： 基因组不稳定的特点是从 DNA 碱基突变到染色体的遗传改变 重排是许多遗传性人类疾病、各种癌症和早产儿的驱动因素 老化。染色体不稳定性尤其是由不准确的染色体分离引起的 端粒和着丝粒功能障碍。大量流行病学研究强调了其核心作用 氧化应激暴露导致端粒和着丝粒功能障碍的发生。然而，至关重要的是， 功能障碍背后的机制尚不清楚。氧化应激是由不平衡引起的 活性氧的产生和细胞抗氧化防御之间的关系。它源于内生 来源以及环境来源（线粒体代谢、紫外线、空气污染、香烟 抽烟）。它的普遍存在凸显了正确理解其对人类健康影响的重要性。一个专业 氧化应激的影响是诱导氧化 DNA 损伤，并通过碱基切除修复进行修复 （BER）途径，其中聚（ADP-核糖）聚合酶（PARP）是主要参与者。 PARP1 和 PARP2 是 负责聚（ADP-核糖基）化，这是一种蛋白质翻译后修饰，可调节 其蛋白质靶标的招募和相互作用。该提案的目标是 (i) 揭示机制 氧化应激介导的基因组不稳定性，重点关注其对端粒和着丝粒的影响，两个 基因组位点对于基因组稳定性至关重要，并且 (ii) 破译 PARP 酶在保护基因组中的贡献 DNA 氧化损伤后的端粒和着丝粒 DNA。更具体地说，我们的目标是评估影响 着丝粒上氧化 DNA 碱基和 BER 单链断裂中间体的慢性诱导 端粒完整性。我们还将确定和评估聚（ADP-核糖基）化对着丝粒和 端粒蛋白靶标。为此，我们将利用独特且创新的化学光遗传学工具来诱导 端粒和着丝粒处的氧化 DNA 局部损伤，而不影响基因组的其余部分。这 将使我们能够明确地将表型变化和 PARP 依赖机制与端粒或 着丝粒损伤。这些项目将填补关于聚（ADP-核糖基）化如何长期存在的知识空白 在基因组的两个关键区域协调 DNA 修复。他们还将揭示氧化应激如何 基因组不稳定的普遍因素，可以导致多种人类疾病。最终，我们的工作将 有助于开发针对基因组特定区域的新治疗策略并提供信息 已广泛用于癌症治疗的 PARP 抑制剂的合理设计和使用。