Uncovering molecular effectors of mammalian aging

项目摘要 衰老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是最常见的疾病。 快速增长的未满足的医疗需求在我们的社会。然而，虽然某些“衰老的标志”已经被定义， 驱动（和对抗）哺乳动物衰老表型的关键分子介质还有待于 系统地探索，部分原因是应用经典功能性遗传学的技术挑战， 方法，这需要费力的一代和老化（！）复杂的基因特异性生殖系， 条件敲除等位基因，衰老生理学的研究。由于这种巨大的知识差距， 开发人类衰老病理学新疗法的重大障碍，我们在这个项目中的目标是 建立一种新的，更容易的方法来询问调节哺乳动物器官的基因和途径 在整个生命周期中的功能和修复。 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 实验性地诱导血液和骨骼中干细胞的基因组发生可编程突变， 肌肉在完整的动物，而不需要干细胞分离和移植。通过靶向 内源性干细胞，我们允许这些突变的维持和繁殖，但规避了 需要去除这些细胞的天然生物生态位，这可能会诱导细胞应激并改变干细胞 行为通过暴露于非生理性离体条件。我们还可以快速测试潜在的 组合基因效应，在多种遗传背景和不同年龄的小鼠中。因此，我们的方法 提供了一个更强大的，更高的通量，对生物体衰老的分子效应器， 将使我们能够测试以前无法接近的假设，关于体细胞诱变事件的影响， 在老化的器官系统中，并确定可能驱动早熟发作或介导 保护免受器官系统的退化表型。 总之，我们的工作将产生新的平台技术，用于询问哺乳动物基因功能 在体内，对衰老生理学和再生生物学的基本机制的新见解， 潜在广泛有用的原位遗传治疗方法。

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.