Senescent Cell Burden in Human Aging and Obesity: Functional Consequences and Reduction by Caloric Restriction

项目摘要 这项建议的一个主要目的是使候选人杰米·贾斯蒂斯博士具备成为一名 独立研究者，他们可以将延长健康寿命的干预措施推进到随机、对照 在老年人中进行试验。具体来说，细胞衰老是衰老的生物学标志， 有证据表明，这可能对与衰老有关的疾病和功能产生深远的影响， 衰老细胞导致啮齿动物健康寿命的显著改善。将这些发言翻译成 已经提出了临床试验，但细胞衰老和治疗潜力的健康后果还没有 在人类中进行了评估。Justice博士在少数老年女性中的初步数据是第一个 显示表达肿瘤抑制蛋白和衰老生物标志物p16 INK 4a的细胞存在于 脂肪组织从老年人和相关的身体功能较差，但运动和体重减轻的热量 限制可以减轻这种负担。拟议的研究项目代表了关键的下一步， 在一项前瞻性随机对照试验中检查热量限制（CR）对细胞衰老的影响 （RCT）。主要假设是CR干预将减少衰老细胞负荷，并且这种减少 将与功能和代谢结果的改善有关。这将通过资本化来实现 最近NIH资助的RCT（VEGGIE，R 01 DK 103531）和候选人从事的跨学科研究 主要指导团队（Nicklas、Ding、Kritchevsky、柯克兰博士）。VEGGIE将决定CR的效果 在200名年龄在40-65岁的男性和女性中，旨在实现10%的体重减轻与健康教育控制 肥胖（BMI 30-45 kg/m2），以表征CR在脂肪细胞中的表观遗传和转录组学效应， 外周血单核细胞和T细胞，以及与身体和代谢功能的关系。我们提出了一个 在90名参与者（50-65岁，每组n=45）的子集中进行辅助研究，以确定 对衰老细胞负荷的CR（目标1）：a）表达p16 INK 4a的衰老细胞的比例 （免疫组织化学）; B）衰老生物标志物的表达 在分离的脂肪细胞和单核细胞（RNAseq）和T细胞（p16 INK 4a表达）中的SASP生物标志物;和 血浆（细胞因子/趋化因子组）。我们还将研究年龄和肥胖与肥胖的横截面关系， 细胞衰老（目标2），以及衰老生物标志物变化与身体功能之间的关系 和代谢结果（目标3）。拟议的研究与批准的NIA概念一致， 为人类研究开发与衰老相关的生物学机制的标志物。此外，它还将提供必要的 为候选人提供培训，他们将建立细胞衰老和转化研究方面的专业知识，以及 培养在具有生物学结果的领先临床试验中的能力。这种方法提供了理想的 平台，以促进候选人的职业生涯作为一个独立的调查员，并提供基础， 确定细胞衰老在人类年龄相关功能衰退中的作用。

Project Summary A key aim of this proposal is to equip the candidate, Dr. Jamie Justice, with the expertise to become an independent investigator who can advance interventions that extend healthy lifespan to randomized, controlled trials in older persons. Specifically, cellular senescence is a biologic hallmark of aging that emerging preclinical evidence indicates could have profound consequences on aging-related disease and function, and removal of senescent cells results in robust improvements in healthspan in rodents. Translation of these interventions to clinical trial has been proposed, yet health consequences of cell senescence and therapeutic potential has not been evaluated in humans. Dr. Justice's preliminary data in a small number of older women are the first to show that cells expressing tumor suppressor protein and senescence biomarker p16INK4a are present in adipose tissue from older adults and related to worse physical function, but exercise and weight loss by caloric restriction may mitigate this burden. The proposed research project represents a critical next step by examining the effects of caloric restriction (CR) on cell senescence in a prospective randomized controlled trial (RCT). The primary hypothesis is that a CR intervention will reduce senescent cell burden and this reduction will be related to improvement in functional and metabolic outcomes. This will be accomplished by capitalizing on a recent NIH-funded RCT (VEGGIE, R01DK103531) and the candidate's engaged inter-disciplinary primary mentoring team (Drs. Nicklas, Ding, Kritchevsky, Kirkland). VEGGIE will determine the effects of CR designed to achieve 10% weight loss vs. health education control in 200 men and women aged 40-65 years with obesity (BMI 30-45 kg/m2), to characterize epigenetic and transcriptomic effects of CR in adipocytes and peripheral blood monocytes and T cells, and associations with physical and metabolic function. We propose an ancillary investigation in a subset of 90 participants (50-65 years, n=45 per grp) to determine the effects of CR on senescent cell burden (Aim 1): a) proportion of p16INK4a expressing senescent cells (immunohistochemistry) in subcutaneous abdominal adipose tissue; b) expression of senescence biomarkers in isolated adipocytes and monocytes (RNAseq) and T cells (p16INK4a expression); and c) SASP biomarkers in plasma (cytokine/chemokine panel). We will also examine cross-sectional associations of age and obesity with cell senescence (Aim 2), and relationships between changes in senescence biomarkers and physical function and metabolic outcomes (Aim 3). The research proposed is aligned with an approved NIA concept to develop markers of aging-related biologic mechanisms for human studies. Additionally, it will provide essential training for the candidate, who will establish expertise in cell senescence and translational research, and develop competencies in leading clinical trials with biological outcomes. This approach provides the ideal platform to advance the candidate's career as an independent investigator, and provide the foundation to establish the role of cell senescence in human age-related functional decline.