Excision Repair of Environmental Telomere Damage

环境端粒损伤的切除修复

• 批准号: 10397054
• 负责人: Patricia L Opresko
• 金额: $ 91.26万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10397054
• 关键词: Animal Model; Award; Cell Culture Techniques; Cell Proliferation; Cell physiology; Cells; Chromosomes; Chronic; DNA Damage; DNA lesion; Degenerative Disorder; Excision Repair; Functional disorder; Funding; Generations; Genetic; Genome Stability; Genotoxic Stress; Goals; Guanine; Health; Human; Knowledge; Learning; Lesion; Maintenance; Measures; Mus; National Institute of Environmental Health Sciences; Organ; Organism; Outcome; Oxidative Stress; Pathway interactions; Phase; Phenotype; Population; Proteins; Research; System; Technology; Telomere Maintenance; Telomere Shortening; Transgenic Organisms; Translating; Work; Zebrafish; base; cancer cell; cancer prevention; carcinogenesis; cell type; experimental study; flexibility; human tissue; innovation; nucleobase; preservation; programs; repaired; telomere; telomere loss; tool

Summary Numerous studies in human populations, human tissue, animal models and cell culture demonstrate that environmental genotoxic and oxidative stress are associated with accelerated telomere shortening and dysfunction. Telomeres at chromosome ends are essential for genome stability and sustained cell proliferation, and dysfunctional telomeres contribute to degenerative diseases and carcinogenesis in humans. The goals of this project are to advance exciting discoveries and highly innovative work from two NIEHS funded R01 awards investigating the consequences of nucleobase damage and excision repair at telomeres. The overarching hypothesis for this R35 proposal is that telomere shortening and dysfunction caused by environmental genotoxic and oxidative stress, occurs via formation of specific base lesions and toxic repair intermediates that directly interfere with telomere replication and maintenance. Working with collaborators we pioneered a highly innovative chemoptogenetic tool that selectively induces DNA lesions at telomeres. This technology is transformative because targeting well-defined base damage to telomeres allows us to unequivocally attribute phenotypic changes and health outcomes to the induced telomere lesions, eliminating confounding effects of damage elsewhere. We fully validated this system for the targeted formation of a common oxidative guanine lesion at telomeres, and remarkably, we discovered that the chronic generation this lesion induces profound hallmarks of telomere dysfunction that mimic genetic loss of telomere shelterin proteins. This project will probe and uncover the mechanisms of DNA lesion induced telomere loss and dysfunction. A major strategy is to extend and modify this flexible technology in a phased approach for introducing base damage, toxic repair intermediates, bulky monoadducts, and other lesion types. We will measure various cellular and telomeric endpoints after lesion induction and will use candidate and unbiased approaches to identify proteins required to protect telomeres against the various forms of environmentally relevant DNA damage. This chemoptogenetic tool has been adapted for use in model organisms, and as the R35 evolves we will translate what we learn in cell culture to experiments in transgenic zebrafish and mice. Using this system, we will generate telomeric damage in key organs and cell types and will measure the impact on organ function and health. This program will lead to significant advances in mechanistic understanding of how environmentally relevant forms of telomeric DNA lesions impact telomere function, cellular function, and organism health. Ultimately, knowledge gained from this program will be highly valuable for developing new strategies that 1) preserve telomeres to ameliorate the effects of genotoxic and oxidative stress in healthy cells or conversely, that 2) inhibit telomere maintenance in malignant cells to arrest proliferation.

概括 对人群、人体组织、动物模型和细胞培养的大量研究表明 环境遗传毒性和氧化应激与端粒加速缩短有关 功能障碍。染色体末端的端粒对于基因组稳定性和维持细胞至关重要 增殖和功能失调的端粒会导致人类退行性疾病和致癌。 该项目的目标是推进两个 NIEHS 的令人兴奋的发现和高度创新的工作 资助 R01 奖项调查核碱基损伤和端粒切除修复的后果。 R35 提案的总体假设是，端粒缩短和功能障碍是由 环境遗传毒性和氧化应激，通过形成特定的基础损伤和毒性修复而发生 直接干扰端粒复制和维持的中间体。我们与合作者一起工作 首创了一种高度创新的化学光遗传学工具，可选择性诱导端粒 DNA 损伤。这 技术具有变革性，因为针对端粒明确的基础损伤使我们能够 明确地将表型变化和健康结果归因于诱导的端粒损伤，消除 其他地方的损害的混杂影响。我们充分验证了该系统的针对性形成 端粒处常见的氧化鸟嘌呤损伤，值得注意的是，我们发现这种慢性生成 病变引起端粒功能障碍的深刻特征，类似于端粒庇护蛋白的遗传丢失 蛋白质。该项目将探讨和揭示DNA损伤引起端粒丢失和 功能障碍。一个主要策略是分阶段扩展和修改这种灵活的技术 引入碱基损伤、有毒修复中间体、大体积单加合物和其他损伤类型。我们将 在损伤诱导后测量各种细胞和端粒终点，并将使用候选和无偏 识别保护端粒免受各种形式的环境影响所需的蛋白质的方法 相关DNA损伤。这种化学光遗传学工具已适用于模式生物，并且作为 R35 的进化，我们将把我们在细胞培养中学到的知识转化为转基因斑马鱼和小鼠的实验。 使用该系统，我们将在关键器官和细胞类型中产生端粒损伤，并测量其影响 关于器官功能和健康。该计划将在机械理解方面带来重大进展 环境相关形式的端粒 DNA 损伤如何影响端粒功能、细胞功能和 机体健康。最终，从该计划中获得的知识对于开发新的技术非常有价值 1) 保护端粒以改善健康细胞中基因毒性和氧化应激的影响的策略 或者相反，2) 抑制恶性细胞的端粒维持以阻止增殖。