In Vivo Regulation of Protein Turnover by Hormones

激素对蛋白质周转的体内调节

• 批准号: 8512150
• 负责人: K Sreekumaran Nair
• 金额: $ 14.37万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-19 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8512150
• 关键词: 8-Oxo-2' -Deoxyguanosine; ATP Synthesis Pathway; Address; Adverse effects; Aerobic Exercise; Age; American; Antioxidants; Asian Indian; Attenuated; Biological; Buffers; Caloric Restriction; Cells; Central obesity; Characteristics; Chemicals; Coupling; DNA; DNA biosynthesis; Data; Deoxyguanosine; Development; Diabetes Mellitus; Diet; Elderly; Energy Metabolism; European; Exercise; Exhibits; Fat-Restricted Diet; Fatty acid glycerol esters; Functional disorder; Funding; Gel; Genes; Health; Hormones; Immigrant; Individual; Infusion procedures; Insulin; Insulin Resistance; Intervention; Isotopes; Laboratories; Lipids; Measures; Metabolic Diseases; Methodology; Methods; Mitochondria; Mitochondrial DNA; Muscle; Muscle Proteins; Non-Insulin-Dependent Diabetes Mellitus; Nucleic Acids; Obesity; Oxidative Stress; Participant; Pharmaceutical Preparations; Phenylalanine; Physical activity; Placebos; Plasma; Plasma Proteins; Play; Population; Post-Translational Protein Processing; Predisposition; Prevalence; Process; Production; Protein Biosynthesis; Protein Isoforms; Proteins; Proteome; Reactive Oxygen Species; Regulation; Relative (related person); Reporting; Risk; Role; Seminal; Skeletal Muscle; Societies; Spottings; System; Transcript; Two-Dimensional Gel Electrophoresis; base; deamidation; density; improved; in vivo; insight; insulin sensitivity; insulin sensitizing drugs; novel; novel strategies; oxidation; oxidative DNA damage; oxidative damage; protein degradation; protein metabolism; public health relevance; research study; response; sex; therapy design

DESCRIPTION (provided by applicant): We will first determine whether people with high muscle mitochondrial capacity produce higher amount of reactive oxygen species (ROS) on consuming high fat diet and thus exhibit elevated cellular oxidative damage. We previously found that Asian Indian immigrants have high mitochondrial capacity in spite of severe insulin resistance. Somalians are another new immigrant population with rapidly increasing prevalence of diabetes. Both of these groups traditionally consume low caloric density diets, and we hypothesize that when these groups are exposed to high-calorie Western diets, they exhibit increased oxidative stress, oxidative damage, and insulin resistance. We will compare Asian Indians, Somalians, and NE Americans who are matched for age, BMI, and sex. We will measure ROS production in skeletal muscle following high fat meal. We will compare the oxidative damage to proteins, DNA, and lipids in these three populations following 2 weeks of high fat diet in comparison with low fat diet. We will determine if elevated levels of oxidative damage in these populations is accompanied by high mitochondrial capacity, higher ROS-emitting potential, and lower insulin sensitivity than NE. Secondly the proposal will apply a novel method developed in our laboratory to determine whether abdominally obese people with severe insulin resistance, high insulin levels, and oxidative stress accumulate old and damaged muscle and plasma proteins that may cause deleterious functional consequences. We will determine whether decreasing circulating insulin and oxidative stress by enhancing insulin sensitivity decreases the accumulation of old and damaged protein in muscle and plasma. We hypothesize that three different modes of enhancing insulin sensitivity act by different mechanisms to decrease the accumulation of old and damaged proteins and DNA oxidation. We expect caloric restriction (CR) to reduce oxidative stress by reducing ROS production and thus decrease oxidative damage to proteins and DNA. In contrast aerobic exercise increases ROS production but stimulates a robust antioxidant defense system. Furthermore, unlike CR we expect exercise to increase the synthesis of nascent proteins and turnover of old, damaged proteins. Insulin sensitizers reduce oxidative stress and enhance clearance of old and damaged protein. We will study abdominally obese people and compare them with lean participants to determine whether these insulin resistant people accumulate more damaged proteins and DNA in comparison with lean insulin sensitive people. We will then determine whether 16 weeks of aerobic exercise, caloric restriction and insulin sensitizers versus placebo will attenuate oxidative damage to proteins and DNA and improve insulin sensitivity. The proposed studies will be performed utilizing the state-of-the-art methods many of which were developed in our laboratory during the previous funding period. We expect the results from these studies to provide seminal insights into the underlying mechanism of insulin resistance and type 2 diabetes, in addition to demonstrating mechanisms by which a functional proteome is maintained in vivo. PUBLIC HEALTH RELEVANCE: The proposed experiments investigate the potential novel underlying mechanisms of rapidly expanding prevalence of diabetes and related health problems in the society. First specific aim is to determine whether more efficient mitochondria, the powerhouse of cell that produce chemical energy, causes adverse effects on DNA and protein when transitioning from a diet of low calorie content to that of high energy content. The second and third aims are to measure the accumulation of damaged and old proteins in muscle and plasma, using a novel methodology in obese and insulin resistant people and to determine how this potentially deleterious process is altered by aerobic exercise, caloric restriction, and medication that enhance insulin sensitivity and reduce high insulin levels.

描述（由申请人提供）：我们将首先确定肌肉线粒体能力高的人在食用高脂肪饮食时是否会产生更多的活性氧（ROS），从而表现出更高的细胞氧化损伤。我们之前发现，尽管有严重的胰岛素抵抗，亚裔印度移民仍具有较高的线粒体能力。索马里人是另一个糖尿病患病率迅速上升的新移民群体。这两个群体传统上都食用低热量密度饮食，我们假设当这些群体接触高热量西方饮食时，他们表现出氧化应激、氧化损伤和胰岛素抵抗增加。我们将比较年龄、体重指数和性别匹配的亚裔印度人、索马里人和东北美洲人。我们将测量高脂肪餐后骨骼肌中活性氧的产生。我们将比较这三个人群在两周的高脂肪饮食与低脂肪饮食后对蛋白质、DNA 和脂质的氧化损伤。我们将确定这些人群中氧化损伤水平升高是否伴随着比 NE 更高的线粒体容量、更高的 ROS 释放潜力和更低的胰岛素敏感性。其次，该提案将应用我们实验室开发的一种新方法来确定患有严重胰岛素抵抗、高胰岛素水平和氧化应激的腹部肥胖者是否会积累老化和受损的肌肉和血浆蛋白，从而可能导致有害的功能后果。我们将确定通过增强胰岛素敏感性来减少循环胰岛素和氧化应激是否会减少肌肉和血浆中陈旧和受损蛋白质的积累。我们假设三种不同的增强胰岛素敏感性的模式通过不同的机制发挥作用，以减少旧的和受损的蛋白质的积累以及 DNA 氧化。我们期望热量限制 (CR) 通过减少 ROS 的产生来减少氧化应激，从而减少对蛋白质和 DNA 的氧化损伤。相比之下，有氧运动可以增加活性氧的产生，同时刺激强大的抗氧化防御系统。此外，与 CR 不同，我们期望运动能够增加新生蛋白质的合成和旧的受损蛋白质的周转。胰岛素增敏剂可减少氧化应激并增强旧蛋白质和受损蛋白质的清除。我们将研究腹部肥胖的人，并将他们与瘦的参与者进行比较，以确定这些胰岛素抵抗的人是否比瘦的胰岛素敏感的人积累更多受损的蛋白质和 DNA。然后我们将确定 16 周的有氧运动、热量限制和胰岛素增敏剂与安慰剂相比是否会减轻蛋白质和 DNA 的氧化损伤并提高胰岛素敏感性。拟议的研究将利用最先进的方法进行，其中许多方法是我们实验室在上一个资助期间开发的。我们期望这些研究的结果除了证明体内功能蛋白质组的维持机制之外，还能为胰岛素抵抗和 2 型糖尿病的潜在机制提供开创性的见解。 公共卫生相关性：拟议的实验研究了社会中糖尿病和相关健康问题迅速蔓延的潜在新机制。第一个具体目标是确定当从低热量饮食转变为高能量饮食时，更高效的线粒体（细胞产生化学能的动力源）是否会对 DNA 和蛋白质造成不利影响。第二个和第三个目标是在肥胖和胰岛素抵抗人群中使用一种新的方法来测量肌肉和血浆中受损和老化蛋白质的积累，并确定有氧运动、热量限制和药物治疗如何改变这种潜在有害的过程。增强胰岛素敏感性并降低高胰岛素水平。