Uncovering molecular effectors of mammalian aging

项目摘要 老龄化是大多数慢性退行性疾病的最大风险因素，包括心血管疾病， 肌肉骨骼和神经退行性功能障碍，以及与年龄相关的疾病现在最常见 我们社会中快速增长的未得到满足的医疗需求。然而，尽管某些“衰老的标志”已经被定义， 驱动(和反对)哺乳动物衰老表型的关键分子介体尚未确定 系统地探索，部分是由于应用经典功能遗传学的技术挑战 方法，这需要辛苦的一代和老化(！)复杂的基因特定的种系和 条件基因敲除等位基因，用于衰老生理学研究。由于这种巨大的知识差距呈现出一种 开发人类衰老病理的新疗法的重大障碍，我们在这个项目中的目标是 建立一种新的、更简便的方法来询问调控哺乳动物器官的基因和途径 在一生中发挥作用并进行修复。 我们的方法将利用独特的体内基因组编辑系统，通过该系统，我们可以 通过实验将可编程突变引入血液和骨骼中的干细胞基因组 在完整的动物体内移植肌肉，不需要干细胞分离和移植。通过锁定目标 内源性干细胞，我们允许这些突变的维持和繁殖，但绕过 需要移除这些细胞的天然生物利基，这会导致细胞应激并改变干细胞 暴露在非生理的体外条件下的行为。我们还可以快速测试潜力 组合基因效应，在多个遗传背景和不同年龄的小鼠中。因此，我们的方法 提供了一个更强大和更高吞吐量的观点，了解生物衰老的分子效应，这 将使我们能够测试以前无法接近的关于体细胞诱变事件影响的假设 在老化的器官系统中，并找出可能驱动早熟发生或中介的新的调节因子 保护不受器官系统退化表型的影响。 总而言之，我们的工作将产生询问哺乳动物基因功能的新平台技术 在体内，对衰老生理学和再生生物学的基本机制的新见解，以及新的和 在现场实施遗传疗法的潜在的广泛有用的方法。

Project Summary Aging is the single largest risk factor for most chronic degenerative diseases, including cardiovascular, musculoskeletal and neurodegenerative dysfunctions, and age-associated diseases now represent the most rapidly growing unmet medical need in our society. Yet, while certain “hallmarks of aging” have been defined, the critical molecular mediators that drive (and oppose) mammalian aging phenotypes have yet to be systematically explored, due in part to the technological challenges of applying classic functional genetic approaches, which require the laborious generation and aging(!) of complex gene-specific germline and conditional knockout alleles, to studies of aging physiology. As this substantial knowledge gap presents a significant impediment to developing new therapies for human aging pathologies, we aim in this project to establish a new, more facile approach to interrogating the genes and pathways that regulate mammalian organ function and repair throughout life. Our approach will take advantage of a unique in vivo genome editing system through which we can experimentally induce programmable mutations into the genomes of stem cells in the blood and skeletal muscle in intact animals, without the requirement for stem cell isolation and transplantation. By targeting endogenous stem cells, we allow for the maintenance and propagation of these mutations but circumvent the need to remove these cells their native biological niche, which can induce cellular stress and alter stem cell behavior by exposure to non-physiological ex vivo conditions. We also enable rapid testing of potential combinatorial gene effects, in multiple genetic backgrounds and in mice of various ages. Thus, our approach provides a more powerful, and higher throughput, view into the molecular effectors of organismal aging, which will allow us to test previously unapproachable hypotheses regarding the impact of somatic mutagenic events in aging organ systems and to identify novel regulators that may drive the precocious onset of, or mediate protection from, degenerative phenotypes across organ systems. Taken together, our work will yield new platform technologies for interrogating mammalian gene functions in vivo, new insights into fundamental mechanisms of aging physiology and regenerative biology, and new and potentially broadly useful methods for effecting genetic therapies in situ.