A subtle threat: L1 transposons and their impact on aging

微妙的威胁：L1 转座子及其对衰老的影响

• 批准号: 9328669
• 负责人: Matthew Alan Simon
• 金额: $ 5.71万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9328669
• 关键词: Address; Adult; Affect; Age; Aging; Aging-Related Process; Biological; Biological Testing; Biology; Brain; CRISPR interference; CRISPR/Cas technology; Cell Line; Cell model; Cell physiology; Cells; Cellular Immunity; Cultured Cells; DNA; DNA Repair; Data; Development; Disease; Elements; Family member; Follow-Up Studies; Functional disorder; Generations; Genes; Genetic; Genetic Transcription; Genome; Genome Stability; Genomic DNA; Genomic Instability; Genomics; Goals; Health; Human; Knock-out; Life Cycle Stages; Light; Longevity; Malignant Neoplasms; Methods; Mobile Genetic Elements; Molecular Genetics; Mus; Mutation; Organism; Parasites; Paste substance; Pharmaceutical Preparations; Pharmacology; Phenotype; Physiology; Play; Process; Proteins; RNA; RNA Interference; RNA-Directed DNA Polymerase; RNAi vector; Regulation; Repetitive Sequence; Reporting; Resources; Retrotransposition; Retrotransposon; Reverse Transcriptase Inhibitors; Reverse Transcription; Role; Sirtuins; Site; Stress; System; Technology; Time; Tissues; Transcript; Transcription Initiation Site; Translations; Work; Youth; age related; aged; biological adaptation to stress; body system; experimental study; genome editing; knock-down; mRNA Expression; mammalian genome; mouse model; resistance mutation; small hairpin RNA; transposon/insertion element

ABSTRACT LINE1 (L1) retrotransposable elements occupy approximately 20% of a mammalian genome. They are mobile DNA elements that can insert into new genomic sites using a copy and paste mechanism. This process, known as retrotransposition, is deleterious at multiple levels such as generation of mutations by inserting into genes, generating DNA breaks and genomic instability, and placing undue burden on transcriptional apparatus. Recent evidence suggests that L1s become activated in aged tissues, certain cancers and in the absence of SIRT6, an aging- relevant sirtuin important for genomic stability and DNA repair. Our preliminary data show that pharmacological inhibition of L1 retrotransposition extends lifespan of a progeroid mouse model. The correlation of L1 activity with aging and age-related phenotypes suggests that L1 activation may contribute to the onset of aging and age-related disease. However, the exact role L1s play in the aging process, what tissues are primarily affected and what aspects of L1 activity contribute to aging remain unclear. As such, the goal of this project is to determine how L1 activity changes in multiple tissues with age and to dissect which aspects of L1 activity are toxic to their host cells. To this end, I will pursue the following specific aims: (1) Determine age- related changes in L1 activity in multiple organ systems by examining DNA, RNA, protein, and translation related activities/products. This aim will develop a comprehensive, organism-wide profile of L1 activity, identifying affected/protected tissues for reference and follow-up studies identifying mechanism of regulation. (2) Determine the consequences of L1 inhibition on cellular and organismal physiology. I will disrupt L1 activity at different stages of L1 lifecycle in primary human cells and in mice. I will use CRISPR technology to reduce the number of genomic L1 copies, shRNA and RNAi to conserved L1 sequences to inhibit l1 expression, and reverse transcriptase inhibitors to inhibit L1 reverse transcription and integration. The proposed work will establish whether L1 activity contributes to age-relative dysfunctions and reduced cellular health. Furthermore, I will determine which aspects of L1 activity are most toxic to the cell, and identify the best mode of L1 inhibition.

抽象的 LINE1（L1）逆转录元件占哺乳动物基因组的20％。 它们是移动DNA元素，可以使用副本和粘贴插入新的基因组网站 机制。这个过程被称为逆转录，在多个层面上是有害的 通过插入基因，产生DNA断裂和基因组不稳定性来产生突变， 并给转录设备施加不适当的负担。最近的证据表明L1 在老年组织，某些癌症中被激活，而在没有SIRT6的情况下， 相关的Sirtuin对基因组稳定性和DNA修复很重要。我们的初步数据表明 L1逆转录置的药理抑制作用延长了后代小鼠模型的寿命。 L1活性与衰老和与年龄相关的表型的相关性表明L1激活 可能有助于衰老和与年龄相关的疾病的发作。但是，确切的角色L1扮演 在衰老过程中，哪些组织主要受到影响以及L1活性的哪些方面 有助于衰老尚不清楚。因此，该项目的目标是确定L1 随着年龄的增长，多个组织的活性变化，并剖析L1活性的哪些方面有毒 到他们的宿主细胞。为此，我将追求以下特定目标：（1）确定年龄 - 通过检查DNA，RNA，蛋白质和 翻译相关的活动/产品。这个目标将发展全面，范围 L1活性的特征，识别受影响/受保护的组织进行参考和随访研究 识别调节机制。 （2）确定L1抑制对细胞的后果 和生理学。我将在主要的L1生命周期的不同阶段中断L1活动 人类细胞和小鼠。我将使用CRISPR技术减少基因组L1的数量 副本，shRNA和RNAi对保守的L1序列抑制L1表达，并反向 转录酶抑制剂抑制L1逆转录和整合。拟议的工作将 确定L1活性是否有助于年龄相关功能障碍和降低的细胞 健康。此外，我将确定L1活性的哪些方面对细胞最有毒，以及 确定最佳的L1抑制模式。