Identification of young versus aged proteomes by tagging with non-canonical amino

描述(由申请人提供)：适应老龄化世界将带来巨大的经济和社会挑战，最终将需要我们理解的范式转变，以及对老龄化过程的生物医学干预。大量数据表明，当器官干细胞的系统生态位被生化恢复时，多个陈旧器官的内源性干细胞参与生产性组织再生。重要的是，旧的循环环境迅速而显著地抑制了内源性干细胞在年轻器官中的再生能力。这项建议利用已知的循环环境在老化组织修复的恢复中所起的作用，目的是确定导致异慢性异种共生现象的关键分子机制。直到最近，在异慢性异种共生的背景下，还不可能对一种动物的蛋白质组进行特定的标记和询问；然而，通过共PI(David Tirrell)在哺乳动物细胞中表达突变的氨基酰-tRNA合成酶来对含有非规范氨基酸的蛋白质进行细胞选择性代谢标记的发展使这种范式转变方法成为可能。由于康博伊和Tirrell研究小组的共同努力、专业领域和实验模型，这个高风险、高回报的项目变得可行。康博伊团队精通异慢性异型共生和特定因子对组织再生能力影响的研究，而Tirrell实验室开创了时间分辨和细胞选择性蛋白质组学的先河。这些研究改变范式的结果具有多重意义：(1)揭示血清中“年轻”的促再生和“衰老”的抑制性蛋白质组；(2)揭示循环影响肌肉和脑/海马区器官干细胞再生性能的机制；(3)建立一个理解衰老遗传学所需的综合性数据库；(4)确定重振多个器官和延长健康寿命的新方法，方法是系统地给药模拟生理上年轻的血液循环的已定义分子。

DESCRIPTION (provided by applicant): Accommodating an aging world will pose significant economic and social challenges and will ultimately call for both paradigm-shift in our understanding, and biomedical interventions into the aging process. Extensive data demonstrate that when the systemic niches of organ stem cells are biochemically rejuvenated, stem cells endogenous to multiple old organs engage in productive tissue regeneration. Importantly, the old circulatory milieu rapidly and significantly inhibits the regenerative performance of endogenous stem cells in young organs. This proposal uses what is known about the role of the circulatory milieu in the rejuvenation of aged tissue repair, with the goal o determining the key molecular mechanisms that are responsible for the phenomena of heterochronic parabiosis. Until recently, it was technologically impossible to specifically label and interrogate the proteome of one animal in the setting of heterochronic parabiosis; however the development of cell-selective metabolic labeling of proteins with non-canonical amino acids via expression of mutant aminoacyl-tRNA synthetases in mammalian cells by the co-PI (David Tirrell) enabled this paradigm shifting approach. This high-risk high-reward project becomes feasible due to the united efforts, areas of expertise and experimental models of the Conboy and Tirrell research groups. The Conboy team has proficiency in studies of heterochronic parabiosis and characterization of the effects of defined factors on tissue regenerative capacity, whereas the Tirrell laboratory has pioneered and time-resolved and cell-selective proteomics. The paradigm changing outcomes of these studies are many fold: (1) revealing the "youthful" pro-regenerative and "aged" inhibitory proteomes of blood serum, (2) uncovering the mechanisms by which the circulation influences the regenerative performance of organ stem cells in muscle and brain/hippocampus; (3) generating a comprehensive data-base that is required for understanding the genetics of aging and importantly, (4) identifying novel ways to rejuvenate multiple organs and extend healthy life span via systemic administration of defined molecules that emulate the physiologically young blood circulation.