A Novel p16INK4a Reporter System to Assess Aging In Vivo

描述（由申请人提供）：随着65岁以上美国人数量的增长，与年龄有关的疾病的发病率继续上升。因此，现在的研究重点是寻找延长寿命的方法。虽然生物年龄的分子指标很少，但我们和其他人最近发现p16INK4a是哺乳动物衰老的一个强大而准确的标志物。在啮齿类动物中，p16INK4a的诱导与实足年龄直接相关，并且可以通过诸如热量限制等抗衰老策略来减缓。此外，我们的初步数据显示，在健康受试者中，适度运动可以降低p16INK4a水平。尽管有这些数据，但改变生活方式促进长寿的机制在很大程度上仍不明确。在这里，我将利用p16INK4a作为衰老生物标志物的独特特性来评估抗衰老策略的组织特异性。为此，我开发了一种新的敲入报告等位基因p16-LUC，它在内源性p16INK4a启动子的控制下表达萤火虫荧光素酶。重要的是，我的初步数据表明，这种等位基因的诱导与体外细胞衰老相关，并且可以在活体动物中可视化。利用这些小鼠，我计划实现以下具体目标：1)在与哺乳动物衰老过程相关的条件下表征p16- LUC等位基因；2)研究饮食和运动对p16INK4a诱导的影响；3)确定饮食和运动对p16INK4a启动子占用的时间依赖性和器官特异性影响。

DESCRIPTION (provided by applicant): The incidence of age-related diseases continues to rise as the number of Americans over the age of 65 grows. As a result, research is now focused on discovering methods to promote longevity. Although few molecular indicators of biological age have been indentified, we and others have recently shown that p16INK4a serves a robust and accurate marker of mammalian aging. Induction of p16INK4a correlates directly with chronological age in rodents and can be slowed by anti-aging strategies such as caloric restriction. In addition, our preliminary data show that p16INK4a levels are decreased by moderate exercise in healthy human subjects. Despite these data, the mechanisms by which lifestyle modification promotes longevity remain largely undefined. Herein, I will exploit the unique properties of p16INK4a as an aging biomarker to assess the tissue- specificity of anti-aging strategies. To do this, I have developed a novel knockin reporter allele, p16-LUC, which expresses firefly luciferase under control of the endogenous p16INK4a promoter. Importantly, my preliminary data show that induction of this allele correlates with cellular senescence in vitro and can be visualized in living animals. Using these mice I plan to address the following specific aims: 1) Characterize the p16- LUC allele under conditions relevant to the mammalian aging process, 2) Investigate the influence of diet and exercise on the induction of p16INK4a, 3) Determine the time- dependent and organ-specific effects of diet and exercise on p16INK4a promoter occupancy. PUBLIC HEALTH RELEVANCE: These studies will determine the potential of a new mouse model to predict how exercise and diet influence biological aging. In addition, we will gain insight into the processes that cause our bodies to age, helping us to develop new strategies that promote human health and longevity.