NIH resubmission Deyu Li - Etheno adductome and repair pathways

NIH 重新提交 Deyu Li - 乙烯加合组和修复途径

• 批准号: 10659931
• 负责人: Sarah Delaney
• 金额: $ 38.91万
• 依托单位: UNIVERSITY OF RHODE ISLAND
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-10 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10659931
• 关键词: Affect; Alkylation; Amino Acid Sequence; Base Excision Repairs; Carcinogens; Cells; Chromatin; Chronic; Clip; Complex; Core Protein; Data; Dealkylation; Development; Dioxygenases; Discipline; Disease; Enzymes; Epigenetic Process; Eukaryotic Cell; Excision Repair; Family; Fingerprint; Future; Genetic; Genomic Instability; Goals; Health; Histones; Human; Hydroxyl Radical; Infection; Inflammation; Inflammatory; Knowledge; Large Intestine Carcinoma; Lesion; Link; Lipid Peroxidation; Lung Adenocarcinoma; Malignant Neoplasms; Methods; Molecular; Mutation; N-terminal; Neoplastic Cell Transformation; Nucleosome Core Particle; Organism; Oxidative Stress; Pathway interactions; Pattern; Poisson Distribution; Population; Positioning Attribute; Process; Productivity; Proteins; Proteolytic Processing; Reaction; Reporting; Research; Research Project Grants; Site; Tail; Techniques; Testing; Therapeutic; United States National Institutes of Health; Universities; Variant; Vinyl Chloride; Work; adduct; alpha ketoglutarate; base; cancer risk; carcinogenesis; carcinogenicity; chronic infection; clinically relevant; cytotoxic; ds-DNA; epigenetic marker; experimental study; flexibility; genome integrity; improved; in vivo; innovation; member; next generation; novel; repair enzyme; repaired; response; translational potential; translational study

PROJECT SUMMARY Chronic inflammation and persistent infection conditions have long been associated with increased risk of cancer. Growing evidence suggests that cancer-associated inflammatory processes, such as lipid peroxidation, cause genomic instability that can be linked to the development of carcinogenesis. Reactive species from lipid peroxidation are known to damage DNA and form etheno-type adducts. Previously, four etheno DNA adducts have been reported: 1,N6-ethenoadenine (εA), 3,N4-ethenocytosine (εC), 1,N2-ethenoguanine (1,N2-εG), and N2,3-ethenoguanine (N2,3-εG). These etheno lesions are also generated by metabolites of the human carcinogen vinyl chloride. Recently, a new etheno adduct, 3,N4-etheno-5-methylcytosine (ε5mC), was identified. It bears the etheno damage on 5-methylcytosine, an important epigenetic marker in humans. Thus far, no information on the repair and mutagenicity of ε5mC has been reported. Replication of the etheno lesions is known to cause mutations and may constitute a critical step in the pathway leading to neoplastic transformation. Importantly for cells, DNA repair pathways are the guardians of genomic integrity and function to return damaged DNA to its canonical state. This research project focuses on two key repair pathways: base excision repair (BER) and direct reversal repair (DRR). Most of the experiments that give rise to our current understanding of BER and DRR were conducted using DNA oligomers. There is a fundamental gap in knowledge of how repair occurs in the context of chromatin, where eukaryotic DNA is compacted in a complex hierarchy of DNA-protein interactions. At the most fundamental level of chromatin organization, the nucleosome core particle (NCP) is the basic packaging unit that is comprised of ds-DNA wrapped around a histone protein core. The overarching goal of the proposed research is to understand how DNA sequence context and the packaging of DNA into chromatin influence repair of the etheno adductome. The central hypothesis of this proposal is that BER and DRR enzymes repair etheno lesions with different efficiencies, and these distinctive repair profiles are the result of 1) sequence context of the lesion and interactions with the enzyme and 2) modulation of repair by the protein component of chromatin, the histones. Guided by this novel hypothesis, strong preliminary data, and innovative techniques, the proposal investigates three aims that: (1) define the sequence context effects (by considering the 5’ and 3’ neighboring bases) of BER and DRR enzymes in unpackaged DNA oligomers; (2) characterize the repair profiles of the five etheno adducts in NCPs; and (3) determine the extent to which tailless and variant histone proteins provide a mechanism of modulating repair in chromatin. The proposed research is significant because it will reveal key mechanisms and critical differences that influence repair of the etheno adductome and how cells minimize the harmful consequences of these lesions. The results obtained in this work will explain in vivo observations of alkylation damage profiles and contribute to our understanding of mutational hotspots and mutational signatures. Therefore, the research has considerable translational potential to enhance our understanding of DNA repair and the results can assist in the development of future therapeutic treatments that improve cellular defenses against genomic instability.

项目概要 慢性炎症和持续感染状况长期以来一直与癌症风险增加有关。 越来越多的证据表明，与癌症相关的炎症过程，例如脂质过氧化，会导致 基因组不稳定性可能与脂质反应性物质的发生有关。 已知过氧化会损伤 DNA 并形成乙烯型 DNA 加合物，此前有四种乙烯型 DNA 加合物。 已报道：1,N6-乙烯腺嘌呤 (εA)、3,N4-乙烯胞嘧啶 (εC)、1,N2-乙烯鸟嘌呤 (1,N2-εG) 和 N2,3-乙烯鸟嘌呤 (N2,3-εG) 这些乙烯损伤也是由人类致癌物的代谢产物产生的。 最近，鉴定出一种新的乙烯加合物，3,N4-乙烯-5-甲基胞嘧啶（ε5mC）。 乙烯醇对 5-甲基胞嘧啶（人类重要的表观遗传标记）造成的损害迄今为止，尚无相关信息。 据报道，ε5mC 的修复和致突变性会导致乙烯损伤的复制。 突变可能构成导致肿瘤转化途径中的关键步骤。 在细胞中，DNA 修复途径是基因组完整性和功能的守护者，可将受损的 DNA 恢复到原来的状态。 该研究项目重点关注两个关键的修复途径：碱基切除修复（BER）和直接修复。 引起我们目前对 BER 和 DRR 理解的大部分实验都是通过逆向修复 (DRR) 进行的。 使用 DNA 寡聚物进行的修复在修复过程中如何发生的知识存在根本性差距。 染色质，真核 DNA 被压缩在 DNA-蛋白质相互作用的复杂层次结构中。 染色质组织的最基础层面，核小体核心颗粒（NCP）是基本包装 由包裹在组蛋白核心上的双链 DNA 组成的单元。 所提出的总体目标。 研究的目的是了解 DNA 序列背景和 DNA 包装到染色质中如何影响修复 该提案的中心假设是 BER 和 DRR 酶修复乙烯醇。 具有不同效率的损伤，这些独特的修复特征是 1) 的序列背景的结果 损伤和与酶的相互作用以及 2) 染色质蛋白质成分对修复的调节， 在这个新颖的假设、强有力的初步数据和创新技术的指导下，该提案。 研究了三个目标：(1) 定义序列上下文效应（通过考虑 5' 和 3' 相邻序列） 未包装 DNA 寡聚物中 BER 和 DRR 酶的碱基）；(2) 表征五种修复特性； NCP 中的乙烯加合物；(3) 确定无尾和变异组蛋白提供的程度 调节染色质修复的机制这项研究意义重大，因为它将揭示关键。 影响乙烯加合物修复的机制和关键差异以及细胞如何最大限度地减少 这些病变的有害后果将在这项工作中获得的结果解释体内观察结果。 烷基化损伤概况并有助于我们对突变热点和突变特征的理解。 因此，该研究具有巨大的转化潜力，可以增强我们对 DNA 修复的理解 研究结果可以帮助开发未来改善细胞防御的治疗方法 对抗基因组的不稳定性。