Cardiac Mitohormesis Protects Against Diabetic Cardiomyopathy Through Mitophagy

心脏线粒体兴奋作用通过线粒体自噬预防糖尿病心肌病

• 批准号: 9179239
• 负责人: Sang Ging Ong
• 金额: $ 12.77万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9179239
• 关键词: Achievement; Advisory Committees; Animal Model; Antidiabetic Drugs; Antioxidants; Area; Autophagocytosis; Basic Science; Biological Assay; Biology; Blood Vessels; Cardiac; Cardiac Myocytes; Cardiology; Cardiotoxicity; Cardiovascular Diseases; Cardiovascular system; Career Mobility; Cause of Death; Cells; Complex; Coronary Arteriosclerosis; Cytoplasm; Data; Diabetes Mellitus; Disease; Disease model; Environment; Epidemic; Excision; Foundations; Future; Generations; Genetic; Genetic Engineering; Genomics; Glucose; Goals; Heart; Homeostasis; Human; Hyperglycemia; Hypertension; Impairment; Injury; Institutes; Lead; Lysosomes; Maintenance; Medicine; Mentors; Mentorship; Mitochondria; Molecular; Molecular Profiling; Myocardial dysfunction; Myocardium; Names; Nutrient; Organelles; Outcome; Oxidative Stress; Pathogenesis; Pathology; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Physicians; Play; Positioning Attribute; Preclinical Drug Evaluation; Predisposition; Prevention; Preventive Intervention; Process; Proteins; Proteomics; Quality Control; Reactive Oxygen Species; Regulation; Reporting; Research; Research Personnel; Research Project Grants; Resistance; Role; Scientist; Stress; Structure; Study models; Susceptibility Gene; System; Testing; Therapeutic Agents; Therapeutic Intervention; Training; Translational Research; Universities; Work; antioxidant therapy; base; career; career development; diabetic; diabetic cardiomyopathy; diabetic patient; drug testing; effective therapy; induced pluripotent stem cell; inhibition of autophagy; innovation; interest; meetings; mitochondrial dysfunction; novel; novel therapeutics; patient subsets; predicting response; prevent; professor; programs; protein degradation; response; skills; stem cell biology; transcriptome sequencing

PROJECT SUMMARY This proposal describes a five-year career development program to prepare the candidate, Dr. Sang-Ging Ong, for a career as an independent investigator. This program will expand Dr. Ong's scientific background in cardiovascular research by providing additional technical training and expertise in mitochondria biology and stem cell biology, areas in which Dr. Ong has already made significant achievements. The mentor is Dr. Joseph Wu, a Professor of Medicine/Cardiology and Director of the Stanford Cardiovascular Institute at Stanford University. The proposed mentor is a physician scientist with significant expertise in stem cell biology and is an expert in cardiovascular disease modeling. The K99 phase will consist of structured mentorship by the primary mentor, complementary meetings with the advisory committee, formal coursework, a provocative research project, and a program of career transition. Diabetes is at epidemic proportions with 300 million people expected to suffer from diabetes by 2025. Cardiovascular disease is the major cause of death among these patients of which the major contributing factor is coronary artery disease (CAD). However, diabetic patients also suffer from diabetic cardiomyopathy (DCM) independent of the vascular effects of hypertension or CAD. The mechanisms underlying DCM are unclear, and there are currently no specific effective treatments for it. In all cells, including those of heart muscle, the autophagy/lysosome system provides proteolytic mechanisms to regulate protein turnover and degradation. Mitophagy is an autophagic process that specifically removes damaged mitochondria and may be crucial for the proper maintenance of cardiac function when in excess nutrient. The role of mitophagy in the diabetic heart is currently unknown, and in this proposal, Dr. Ong intends to understand the importance of mitophagy in DCM, and explore the underlying mechanisms that regulate mitophagy which may help in translational science. Combining Dr. Ong's expertise in mitochondrial biology with his skills in stem cell biology and genomics/proteomics biology that he is developing while working with Dr. Wu puts him in a unique position to be able to study the importance of mitophagy in human cardiac cells and the molecular mechanisms pertaining to it in ways that have not been done before. Dr. Ong has generated preliminary data demonstrating that mitophagy is impaired in human induced pluripotent-stem cells-derived cardiomyocytes (iPSC-CMs) subjected to hyperglycemia although there is a heterogeneous response. Dr. Ong will seek to conclusively prove that impaired mitophagy increases the susceptibility of iPSC-CMs to hyperglycemic damage, and to potentially identify a molecular signature of mitophagy which may be useful in the future for predicting response to excess glucose (Aim 1). Dr. Ong's preliminary results have also revealed an interesting phenomenon in that cells resistant to hyperglycemic stress are associated with an activation of non-canonical mitophagy despite impaired canonical autophagy. Hence Dr. Ong will investigate the mechanistic basis of impaired mitophagy and also the potential regulation of mitophagy by mild ROS (Aim 2). This is due to Dr. Ong's observation that treatment of iPSC-CMs with antioxidants worsen the detrimental effects of hyperglycemia, indicating an adaptive role of ROS (mitohormesis). In the final aim, Dr. Ong will obtain additional iPSC lines derived from diabetic patients with and without DCM, as well as introducing known diabetes susceptibility genes into isogenic healthy lines. These groups of lines will provide Dr. Ong a proof-of-principle platform for drug screening which shall be based on two formats: (i) testing for currently available anti-diabetic drugs as some drugs have been associated with adverse cardiac outcomes, and (ii) testing for mitophagy inducers which may protect against hyperglycemic damage which is based on my earlier findings (Aim 3). The implications of this work will be the identification of proper mitochondrial homeostasis as a requirement for prevention of DCM which may involve non-canonical mitophagy, highlight the importance of oxidative stress as mitohormetic molecules, and provide a unique human cardiac cells- based platform for drug testing. Completing these studies in a strong mentored environment will lay the foundation for Dr. Ong's transition to his own independent research program.

项目概要 该提案描述了一个为期五年的职业发展计划，旨在帮助候选人 Sang-Ging 博士做好准备 Ong，从事独立调查员的职业。该计划将扩展 Ong 博士的科学背景 通过提供线粒体生物学方面的额外技术培训和专业知识来进行心血管研究 干细胞生物学是王博士已经取得重大成就的领域。导师是Dr. Joseph Wu，斯坦福大学心血管研究所医学/心脏病学教授兼主任 斯坦福大学。拟议的导师是一位在干细胞领域拥有丰富专业知识的医师科学家 生物学，是心血管疾病建模方面的专家。 K99阶段将包括结构化的 主要导师的指导、与咨询委员会的补充会议、正式课程作业、 一个具有挑战性的研究项目，以及一个职业转型计划。 糖尿病已成为流行病，预计到 2025 年将有 3 亿人患有糖尿病。 心血管疾病是这些患者死亡的主要原因，其中主要原因 因素是冠状动脉疾病（CAD）。然而，糖尿病患者也患有糖尿病心肌病 (DCM) 与高血压或 CAD 的血管影响无关。 DCM 的潜在机制是 尚不清楚，目前尚无具体有效的治疗方法。在所有细胞中，包括心脏细胞 肌肉中，自噬/溶酶体系统提供蛋白水解机制来调节蛋白质周转和 降解。线粒体自噬是一种自噬过程，专门清除受损的线粒体，并且可能 当营养过剩时，对于适当维持心脏功能至关重要。线粒体自噬的作用 糖尿病心脏目前尚不清楚，在这项提案中，Ong 博士打算了解糖尿病心脏的重要性 DCM 中的线粒体自噬，并探索调节线粒体自噬的潜在机制，这可能有助于 转化科学。 将 Ong 博士在线粒体生物学方面的专业知识与他在干细胞生物学方面的技能相结合， 他在与吴博士合作期间开发的基因组学/蛋白质组学生物学使他处于独特的地位 能够研究线粒体自噬在人类心肌细胞中的重要性及其分子机制 以前所未有的方式与之相关。 Ong博士已生成初步数据 证明人诱导多能干细胞衍生的心肌细胞中线粒体自噬受损 (iPSC-CM) 遭受高血糖，但存在异质反应。 Ong博士将寻求 最终证明线粒体自噬受损会增加 iPSC-CM 对高血糖的易感性 损伤，并可能识别线粒体自噬的分子特征，这在未来可能有用 预测对过量葡萄糖的反应（目标 1）。 Ong博士的初步结果还揭示了 有趣的现象是，细胞抵抗高血糖应激与激活 尽管规范自噬受损，但仍存在非规范线粒体自噬。因此，Ong博士将调查 线粒体自噬受损的机制基础以及轻度 ROS 对线粒体自噬的潜在调节（目标 2）。 这是由于 Ong 博士观察到，用抗氧化剂处理 iPSC-CM 会加剧有害的情况。 高血糖的影响，表明 ROS（线粒体毒效作用）的适应性作用。 Ong博士的最终目标是 获得来自患有或不患有 DCM 的糖尿病患者的额外 iPSC 系，以及引入 将已知的糖尿病易感基因转化为同基因健康系。这些线组将为 Ong 博士提供 药物筛选原理验证平台应基于两种形式：(i) 测试当前 可用的抗糖尿病药物，因为某些药物与不良心脏后果有关，并且 (ii) 测试线粒体自噬诱导剂，可以防止高血糖损伤，这是基于我的 早期发现（目标 3）。这项工作的意义在于鉴定适当的线粒体 体内平衡作为预防 DCM 的必要条件，可能涉及非典型线粒体自噬，强调 氧化应激作为线粒体激素分子的重要性，并提供了独特的人类心肌细胞- 药物检测平台。在强有力的指导环境中完成这些研究将为 为 Ong 博士过渡到自己的独立研究项目奠定了基础。