Calorie restriction and aging

热量限制和衰老

• 批准号: 10007344
• 负责人: Rafael de Cabo
• 金额: $ 67万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10007344
• 关键词: 2 year old; Affect; Age of Onset; Aging; Animals; Biochemical; Blood; Blood Glucose; Body Temperature; Body Weight; Body Weight decreased; Caloric Restriction; Cell Proliferation; Cells; Cellular Metabolic Process; Cessation of life; Chronic Disease; Cognition; Complex; Consumption; Coupled; Data; Data Reporting; Diet; Diet Modification; Dietary Intervention; Disease; Energy Intake; Evaluation; Faculty; Fasting; Fathers; Fatty Liver; Female; Food; Gene Expression; Generations; Genetic; Gerontology; Goals; Growth; Growth Factor; Health; Heritability; Histopathology; Hormones; Hour; House mice; Human; Hybrids; Hypothalamic structure; In Vitro; Incidence; Insulin; Intervention; Investigation; Laboratories; Laboratory Study; Laboratory mice; Long-Term Effects; Longevity; Macronutrients Nutrition; Malignant Neoplasms; Malnutrition; Measurable; Measures; Metabolic; Modeling; Molecular; Monkeys; Morbidity - disease rate; Mouse Strains; Mus; Neurosecretory Systems; Outcome; Pathologist; Pathology; Pathway interactions; Phenotype; Physiological; Pilot Projects; Play; Primates; Process; Protocols documentation; Publishing; Regimen; Role; Scientist; Serum; Severities; Structure of nucleus infundibularis hypothalami; Summary Reports; Testing; Time; Tissues; Urine; age effect; age related; behavior measurement; biological adaptation to stress; blood glucose regulation; cell growth; feeding; follow-up; functional decline; healthspan; improved; male; mimetics; mortality; nonhuman primate; novel strategies; nutrition; offspring; phrases; research and development; response; sex; theories

The aims of this project are to assess the effects of aging and caloric restriction (CR) at a cellular and biochemical level of analysis, to identify physiological mechanisms associated with these effects, and to evaluate interventions/molecular pathways that might alter age-related declines in function. Laboratory studies consistently demonstrate extended lifespan in animals on calorie restriction (CR), where total caloric intake is reduced by 10-40% but adequate nutrition is otherwise maintained. CR has been further shown to delay the onset and severity of chronic diseases associated with aging such as cancer, and to extend the functional health span of important faculties like cognition. Less understood are the underlying mechanisms through which CR might act to induce such alterations. One theory postulates that CR's beneficial effects are intimately tied to the neuroendocrine response to low energy availability, of which the arcuate nucleus in the hypothalamus plays a pivotal role. CR induces measurable changes on circulating levels of several hormones and growth factors that regulate cell growth and proliferation. Serum obtained from CR animals alters growth, proliferation and stress responses of cells in culture. We have demonstrated that it is possible to investigate certain aspects of CR using this in vitro approach. This approach lends itself to a more rapid investigation of possible mechanisms and, perhaps more importantly to the research, development and rapid evaluation of interventions that would be able to induce or promote a phenotype similar to that seen with CR, essentially a CR mimetic. 1.- We are investigating the differential response to CR in male and female F1 offspring of DBA/2J and C57BL/6J mice. In a follow up to our published study 19, we wanted to determine if CR would have the same lifespan and healthspan benefits in the F1 offspring as it did with the parental strains of mice, and further investigate the mechanisms underlying these observations. In order to investigate the role of CR in extending lifespan in laboratory mice, the DBA2 strain, which is classically considered unresponsive to CR, and the standard C57BL6 mouse strain were subjected to 20% or 40% CR, and their response compared to ad libitum (AL)-fed mice 19. We found that male and female DBA2 mice were responsive to CR with maximum lifespan extension at 40% CR. In contrast, male and female C57BL6 mice responded very well to 20% CR, but there was no lifespan extension in 40% CR-fed females when compared to AL-fed C57BL6 mice 19. To test whether there was maternal inheritance, we crossed male and female offspring of DBA/2 dams x C57BL/6 fathers (D2B6F1) and C57BL/6 dams x DBA/2 fathers (B6D2F1) and maintained them on AL, 20% or 40% CR and tracked their survival (Figure 10). The study is still ongoing; however, preliminary results indicate that the B6D2F1 mice are unresponsive to CR, which is in contrast to previously published results 13. D2B6F1 mice respond best to 40% CR, with 20% CR having little to no effect in all F1 hybrids. 2.- We are also determining if the two different diets used in the NHP CR studies have the same outcomes in mice, in terms of longevity and health, and to investigate the underlying mechanism. In a novel approach to characterize the role of macronutrients in primates, we are comparing the short- and long-term effects of NIA and WIS NHP diets fed to mice in AL, pair-fed (PF) and CR regimens. This study is currently ongoing and expected to be finished within the next 3-6 months. In order to further understand the differences in survival and health outcomes and investigate the underlying mechanisms between the NIA and WNPRC diets, we established two pilot studies using mice and NHPs fed the NIA or WNPRC diets ad libitum. We found comparable metabolic effects in terms of bodyweight gain and fasting blood glucose over 3-4mo of diet between mice and monkeys, indicating the dietary effects are conserved across species. From these data, a longevity study was initiated with 4mo-old male C57BL/6J mice. Single-housed mice were started on either the WNPRC or NIA diet, provided AL, 30% CR or restricted to a single isocaloric daily allotment (pairfed, PF) of food of the opposite diet at approximately AL levels in order to control for slight differences in caloric content between diets. CR and PF mice were fed a single daily allotment at approximately 2pm every day. Any food remaining the following day was removed, weighed and recorded to yield an accurate measure of daily energy consumption. Physiological, metabolic and behavioral measurements were collected across the study, including weekly body weights and temperatures, insulin and glucose homeostasis, metabolic cage, blood, and urine. A subset of mice was euthanized at 2 years of age and tissues collected for further analysis. A detailed histopathology assessment of the mice is underway by a board-certified veterinary pathologist. This study is ongoing, We assessed various measures of healthspan, including histopathology, and found important differences in the incidence and type of pathologies that mice died with. Notably, CR and PF protocols were able to delay the onset of pathologies in mice, whereas WIS-fed mice had a higher incidence of fatty liver compared to mice on NIA diet. This demonstrates that diet plays a role in the type of pathologies that an animal will develop, but the age of onset of the pathology and subsequent death are determined by the feeding regimen (CR, PF). This study will be published in September 2018 in Cell Metabolism, a quick summary of the reported data is as follows; Adequate nutrition with reduced caloric intake (CR) delays age-related diseases and extends lifespan in most species. However, CR studies in non-human primates (NHP) have produced divergent outcomes, challenging CRs applicability to humans. Here, we mimicked in male mice the diet compositions and feeding paradigms used in the two NHP studies. Both diets were tested with three paradigms: lifelong CR, ad libitum (AL), and meal-feeding (MF). MF mice gorged, which resulted in extended periods of daily fasting. This extended daily fasting caused a significant improvements in morbidity and mortality compared to AL. These results indicate that merely fasting daily for a few hours improves healthspan and lifespan, regardless of dietary composition, caloric intake, or bodyweight. Extended periods of daily fasting may be much more attainable by humans than lifelong diet modifications, caloric reductions, and weight loss. Consequently, this discovery might have a significant impact on and wide applicability to human health.

该项目的目的是在细胞和生化分析水平上评估衰老和热量限制（CR）的影响，确定与这些影响相关的生理机制，并评估可能改变与年龄相关的衰退的干预措施/分子途径在功能上。实验室研究一致证明，限制热量 (CR) 可以延长动物的寿命，即总热量摄入量减少 10-40%，但仍能保持充足的营养。 CR 已被进一步证明可以延缓癌症等与衰老相关的慢性疾病的发作和严重程度，并延长认知等重要功能的功能健康范围。 CR 可能诱发这种改变的潜在机制尚不清楚。一种理论认为，CR 的有益作用与神经内分泌对低能量可用性的反应密切相关，其中下丘脑的弓状核发挥着关键作用。 CR 会引起调节细胞生长和增殖的几种激素和生长因子的循环水平发生可测量的变化。从 CR 动物获得的血清会改变培养细胞的生长、增殖和应激反应。我们已经证明，使用这种体外方法研究 CR 的某些方面是可能的。这种方法有助于更快速地研究可能的机制，也许更重要的是，有助于研究、开发和快速评估能够诱导或促进与 CR 相似的表型（本质上是 CR 模拟物）的干预措施。 1.- 我们正在研究 DBA/2J 和 C57BL/6J 小鼠的雄性和雌性 F1 后代对 CR 的差异反应。在我们发表的研究 19 的后续研究中，我们想要确定 CR 对 F1 后代是否具有与亲代小鼠品系相同的寿命和健康益处，并进一步研究这些观察结果背后的机制。 为了研究 CR 在延长实验室小鼠寿命方面的作用，对传统上被认为对 CR 无反应的 DBA2 品系和标准 C57BL6 小鼠品系进行了 20% 或 40% CR 试验，并将它们的反应与自由采食进行比较(AL) 喂养的小鼠 19. 我们发现雄性和雌性 DBA2 小鼠对 CR 有反应，CR 达到 40% 时寿命延长最大。相比之下，雄性和雌性 C57BL6 小鼠对 20% CR 的反应非常好，但与 AL 喂养的 C57BL6 小鼠相比，40% CR 喂养的雌性小鼠的寿命没有延长 19。为了测试是否存在母系遗传，我们将雄性杂交DBA/2 母亲 x C57BL/6 父亲 (D2B6F1) 和 C57BL/6 母亲 x DBA/2 父亲的雌性后代(B6D2F1) 并将其维持在 AL、20% 或 40% CR 状态并追踪其生存情况（图 10）。该研究仍在进行中；然而，初步结果表明，B6D2F1 小鼠对 CR 无反应，这与之前发表的结果相反 13。D2B6F1 小鼠对 40% CR 的反应最好，20% CR 对所有 F1 杂交种几乎没有影响。 2.- 我们还在确定 NHP CR 研究中使用的两种不同饮食在小鼠中是否在寿命和健康方面具有相同的结果，并调查其潜在机制。在一种表征常量营养素在灵长类动物中的作用的新方法中，我们正在比较在 AL、配对喂养 (PF) 和 CR 方案中喂养小鼠的 NIA 和 WIS NHP 饮食的短期和长期影响。该研究目前正在进行中，预计将在未来 3-6 个月内完成。 为了进一步了解生存和健康结果的差异，并研究 NIA 和 WNPRC 饮食之间的潜在机制，我们利用随意喂养 NIA 或 WNPRC 饮食的小鼠和 NHP 开展了两项试点研究。我们发现，在 3-4 个月的饮食中，小鼠和猴子在体重增加和空腹血糖方面的代谢效应具有可比性，这表明饮食效应在不同物种之间是保守的。 根据这些数据，我们对 4 个月大的雄性 C57BL/6J 小鼠启动了一项长寿研究。单舍小鼠开始采用 WNPRC 或 NIA 饮食，提供 AL、30% CR 或限制为每日单一等热量分配（配对，PF）大约 AL 水平的相反饮食食物，以控制细微差异饮食之间的热量含量。 CR 和 PF 小鼠每天大约在下午 2 点喂食一次。第二天剩余的食物被取出、称重并记录，以准确测量每日能量消耗。在整个研究中收集了生理、代谢和行为测量数据，包括每周体重和体温、胰岛素和葡萄糖稳态、代谢笼、血液和尿液。一部分小鼠在 2 岁时被安乐死，并收集组织用于进一步分析。委员会认证的兽医病理学家正在对小鼠进行详细的组织病理学评估。 这项研究正在进行中，我们评估了健康寿命的各种指标，包括组织病理学，并发现小鼠死亡病理的发生率和类型存在重要差异。值得注意的是，CR 和 PF 方案能够延迟小鼠病理的发生，而与 NIA 饮食的小鼠相比，WIS 喂养的小鼠脂肪肝的发生率更高。这表明饮食在动物发生的病理类型中发挥着作用，但病理的发病年龄和随后的死亡是由喂养方案（CR、PF）决定的。该研究将于2018年9月发表在《Cell Metabolism》上，报告数据简要总结如下；在大多数物种中，充足的营养和减少的热量摄入（CR）可以延缓与年龄相关的疾病并延长寿命。然而，非人类灵长类动物 (NHP) 的 CR 研究产生了不同的结果，对 CR 对人类的适用性提出了挑战。在这里，我们在雄性小鼠中模仿了两项 NHP 研究中使用的饮食成分和喂养模式。两种饮食均采用三种模式进行测试：终身 CR、随意进食 (AL) 和进餐喂养 (MF)。 MF 小鼠狼吞虎咽，导致每日禁食时间延长。与 AL 相比，延长每日禁食时间可显着改善发病率和死亡率。这些结果表明，无论饮食成分、热量摄入或体重如何，每天仅禁食几个小时就可以改善健康状况和寿命。对于人类来说，延长每日禁食期可能比终生调整饮食、减少热量和减肥更容易实现。因此，这一发现可能对人类健康产生重大影响和广泛适用。