Treatment strategy to enhance Nrf2 signaling in older adults: combining acute exercise with the phytochemical sulforaphane

项目总结： 氧化还原平衡在与年龄相关的疾病风险增加中起着关键作用。较低的一个原因 随着年龄的增长，对氧化应激的抵抗是氧化还原状态向氧化程度更高的细胞的逐渐转变 导致细胞信号中断的环境。核红系因子2相关因子2(Nrf2)是主因子 抗氧化剂防御的调节剂。NRF2驱动一系列参与细胞保护和保护的基因的表达 抗氧化剂防御。我们的实验室是第一个证明Nrf2在急性运动中被激活的实验室。 人类，并与动物数据一致，我们发现运动诱导的Nrf2存在与年龄相关的损害 发信号。这突显了一个与老龄化有关的重要问题，即老年人较少 与年轻群体相比，他们对运动刺激很敏感。拟议研究的重点是试图解决 这个问题是通过放大信号和减轻老年人表现出的“运动脱敏”来实现的 以恢复氧化还原平衡。这项研究将检验急性运动和萝卜硫素相结合的假设 与单独使用相比，将改善老年人的Nrf2激活和下游信号转导。萝卜硫素是 一种在十字花科蔬菜中发现的高浓度的植物营养素，是一种有效的Nrf2激活剂。这个 假设将使用两种不同的方法进行验证；第一个实验将使用体内-体外方法， 其中收集自老年男性和女性(≥60岁，n=30)的外周血单核细胞(PBMC)在 急性运动后(体内)将用SFN(体外)进行培养和刺激。这允许更大的 SFN刺激的实验控制。第二个实验将测试临床翻译，应用 口服整个西兰花形式的萝卜硫素对体内的刺激作用 在剧烈运动之前，在同一个人身上发芽。第二个实验将是随机的 安慰剂对照交叉设计。对于所有试验，Nrf2信号将通过Nrf2激活通过 包括结合实验、Nrf2蛋白的核与全细胞比率和Nrf2依赖的基因表达(HO-1， GCLC、NQO1、GR)。潜在的性别差异将被调查。从这项研究中获得的见解如下 将健康生活方式和预防医学的简单干预结合起来是否能改善 老年人对运动的适应性反应。这可能会通过改善 老年美国人的健康和福祉，是美国国家老龄研究所的重要使命。

PROJECT SUMMARY: Redox balance plays a key role in the age-associated increased risk for diseases. One reason for the lower resistance to oxidative stress with age is a gradual shift in the redox state toward a more oxidized cellular environment resulting in disruption of cell signaling. Nuclear erythroid factor 2-related factor 2 (Nrf2) is the master regulator of antioxidant defenses. Nrf2 drives expression of a host of genes involved in cytoprotection and antioxidant defenses. Our lab was the first to demonstrate Nrf2 activation in response to acute exercise in humans, and in agreement with animal data, we found an age-related impairment in exercise-induced Nrf2 signaling. This underscores an important problem related to aging, namely that older individuals are less sensitive to an exercise stimulus compared to younger cohorts. The focus of the proposed study is to try to solve this problem by amplifying the signal and mitigating the “exercise desensitization” exhibited by older individuals to restore redox balance. This study will test the hypothesis that combining acute exercise with sulforaphane will improve Nrf2 activation and downstream signaling in older adults compared to either alone. Sulforaphane is a phytonutrient found in high concentrations in cruciferous vegetables and a potent Nrf2 activator. The hypothesis will be tested using two different approaches; the first experiment will use an in vivo–ex vivo approach, where peripheral blood mononuclear cells (PBMCs) collected from older men and women (≥60y, n=30) pre- and post-acute exercise (in vivo) will be cultured and stimulated with SFN (ex vivo). This allows for a greater experimental control of the SFN stimulus. The second experiment will test the clinical translation applying the sulforaphane stimulus in vivo through an oral supplementation of sulforaphane in the form of whole broccoli sprout material, prior to acute exercise, in the same individuals. This second experiment will be a randomized placebo-controlled cross-over design. For all trials Nrf2 signaling will be measured by Nrf2 activation through an ARE binding assay, nuclear to whole cell ratio of Nrf2 protein, and Nrf2-dependent gene expression (HO-1, GCLC, NQO1, GR). Potential sex differences will be investigated. The insights gained from this study are whether combining simple interventions in the category of healthy lifestyle and preventive medicine can improve the adaptive response to exercise in older individuals. This could have an enormous impact by improving the health and well-being of older Americans, an important mission of the National Institutes of Aging.