Impact of chronic caloric restriction on resident progenitor cells in the heart

长期热量限制对心脏祖细胞的影响

• 批准号: 7599552
• 负责人: KURT William SAUPE
• 金额: $ 22.05万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7599552
• 关键词: Adipose tissue; Adult; Age; Age-Months; Aging; Animals; Attenuated; Autologous; Bromodeoxyuridine; CDKN2A gene; Caloric Restriction; Calories; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cell Cycle Arrest; Cell Lineage; Cells; Chronic; Clinical; Clonality; Data; Diet; Dietary Intervention; Disease; Elderly; Fatty acid glycerol esters; Fluorescence-Activated Cell Sorting; Future; Gene Expression; Goals; Harvest; Health; Heart; In Vitro; Ischemic Preconditioning; Literature; Longevity; Measures; Metabolic; Minerals; Molecular; Mus; Myocardial; Myocardial Infarction; Myocardial Ischemia; Natural regeneration; Patients; Peripheral Vascular Diseases; Phenotype; Physiology; Play; Population; Research; Risk Factors; Role; Side; Source; Stem cells; Techniques; Telomerase; Testing; Tissues; Treatment Efficacy; Vitamins; adult stem cell; age effect; aged; anti aging; base; cell type; dietary restriction; improved; insight; male; middle age; molecular marker; novel strategies; prevent; progenitor; public health relevance; regenerative therapy; response; senescence; stem; theories

DESCRIPTION (provided by applicant): Poor ischemic tolerance and loss of ischemic preconditioning are hallmarks of the aged heart, and contribute to the fact that age is the strongest risk factor for cardiovascular disease. However, the metabolic adjustments to a diet that is calorie restricted (CR) prevents these deleterious effects of aging. Our overall hypothesis is that CR changes the abundance and proliferative state of: 1) resident progenitor cells in the heart, and 2) adipose- derived stem cells that are used to treat peripheral vascular disease, ischemic heart disease and intractable angina. This hypothesis is supported by data demonstrating that CR not only retards aging, but also increases the abundance and proliferative capacity of resident stem cells in some tissues. The long term goal of this research is to exploit the established anti-aging effects of CR to improve cardiac health in patients. These studies will also provide insight into the broader questions of whether diet might influence health via effects on resident stem cells. The first aim is to test whether CR increases the proliferative state of a specific type of cardiac progenitor cell, cardiac side population cells that are Sca1? . We focus on this specific cell type because it is a distinct population that consists of progenitors for a cell type (cardiomyocytes) that likely play a central role in the poor ischemic tolerance and other deleterious aspects of cardiac aging. The second aim is to define the impact of CR on the abundance, proliferative state, and colony forming of adipose-derived stem cells. We have chosen to focus on adipose tissue (epididymal fat pad) as a source of donor cells because it undergoes extensive remodeling during CR, and because of the literature demonstrating the efficacy of these cells to revascularize ischemic tissue and treat myocardial infarctions. Male C57Bl/6 mice will receive a control diet or a CR diet (60% of ad libitum calories) from 6 months of age until they are sacrificed at middle age (12 months) or senescence (24 months of age). This will allow us to determine the impact singly, and in combination, of aging and CR. Fluorescence activated cell sorting will be used to identify cardiac side population cells that are lineage negative/Sca1? (cardiomyocyte progenitor cells), and adipose-derived cells that are lineage negative/CD34? (stem cells with cardiomyogenic potential). The effects of age and CR on the proliferative state of these cells will be assessed by measuring their rates of BrdU incorporation, telomerase activity, and the abundance of molecular markers of cellular division (Ki67) and cell cycle arrest (p16INK4a). To assess the overall proliferative state of cardiomyocyte precursors the rate of new cardiomyocyte formation (BrdU incorporation into cardiomyocytes) and cardiomyocyte age (telomerase activity) will be measured. If CR increases the number and proliferative state of these two types of resident stem/progenitor cells, the proposed studies will form the basis for future studies determining how best to exploit these effects of CR for clinical use. PUBLIC HEALTH RELEVANCE Aging can be slowed and lifespan extended by placing animals on a diet that is very low in calories and enriched in vitamins and minerals. How this type of diet slows aging and prevents age-associated diseases is not known. Our goal is to determine if this diet "rejuvenates" stem cells located in the adult heart and fat.

描述（由申请人提供）：缺血耐受性差和缺血预处理丧失是心脏老化的标志，并有助于年龄成为心血管疾病的最强危险因素。然而，对热量限制饮食（CR）的代谢调整可以防止衰老带来的这些有害影响。我们的总体假设是，CR改变了以下两种细胞的丰度和增殖状态：1)心脏中常驻祖细胞，2)用于治疗周围血管疾病、缺血性心脏病和顽固性心绞痛的脂肪来源干细胞。这一假设得到了数据的支持，数据显示CR不仅延缓衰老，而且还增加了某些组织中驻留干细胞的丰度和增殖能力。本研究的长期目标是利用CR的抗衰老作用来改善患者的心脏健康。这些研究还将为更广泛的问题提供见解，即饮食是否可能通过对常驻干细胞的影响来影响健康。第一个目的是测试CR是否增加了特定类型的心脏祖细胞的增殖状态，心脏侧群细胞是Sca1？。我们关注这种特定的细胞类型，因为它是一个独特的群体，由一种细胞类型（心肌细胞）的祖细胞组成，可能在缺血耐受性差和心脏衰老的其他有害方面发挥核心作用。第二个目的是确定CR对脂肪来源干细胞的丰度、增殖状态和集落形成的影响。我们选择关注脂肪组织（附睾脂肪垫）作为供体细胞的来源，因为它在CR过程中经历了广泛的重塑，也因为文献证明了这些细胞在缺血组织血供重建和治疗心肌梗死方面的功效。雄性C57Bl/6小鼠从6月龄开始饲喂对照饲粮或CR饲粮（占任意热量的60%），直到中年（12月龄）或衰老（24月龄）时被处死。这将使我们能够确定衰老和CR单独或联合的影响。荧光激活细胞分选将用于鉴定谱系阴性的心脏侧群体细胞/Sca1？（心肌细胞祖细胞）和谱系阴性的脂肪来源细胞/CD34？（具有心肌生成潜能的干细胞）。年龄和CR对这些细胞增殖状态的影响将通过测量它们的BrdU掺入率、端粒酶活性、细胞分裂（Ki67）和细胞周期阻滞（p16INK4a）分子标记的丰度来评估。为了评估心肌细胞前体的整体增殖状态，将测量新心肌细胞形成率（BrdU并入心肌细胞）和心肌细胞年龄（端粒酶活性）。如果CR增加了这两种类型的常驻干细胞/祖细胞的数量和增殖状态，那么拟议的研究将构成未来研究的基础，确定如何最好地利用CR的这些作用用于临床应用。通过给动物喂食低热量、富含维生素和矿物质的食物，可以延缓衰老，延长寿命。这种饮食如何延缓衰老和预防与年龄有关的疾病尚不清楚。我们的目标是确定这种饮食是否能“恢复”成人心脏和脂肪中的干细胞。