Importance and Regulation of Cardiac Mitochondrial Pyruvate Transport

摘要 在这份 K99/R00 独立之路奖申请中，凯尔·麦科米斯 (Kyle McCommis) 博士概述了详细的计划： 加强他在最先进的心血管代谢技术方面的研究培训，同时 解决各种心肌病期间代谢改变的新机制。麦科米斯博士是 现为华盛顿大学医学院博士后研究学者，拥有较强的科研实力 评估心脏功能以及线粒体在心脏保护中的作用的背景。凯尔最近的 研究培训深入研究了肝脏和β细胞线粒体丙酮酸代谢。在此，他寻求结婚 这两个研究领域的专业知识旨在研究线粒体丙酮酸代谢的重要性 心脏。 McCommis 博士的主要目标是成为心脏代谢领域的独立研究者 研究，因此提出了职业发展计划，其中他将与各个领域的专家一起接受培训 心脏代谢方面（Finck、Lewandowski 和 Schaffer 博士）。他将从莱万多夫斯基博士那里学到： (1) 分离的灌注小鼠心脏制剂，(2) 扩展凯尔使用示踪剂的经验 了解代谢途径，以及 (3) 示踪代谢物通量的 NMR 分析。来自博士。芬克和谢弗， 凯尔将学习：(1) 糖尿病心脏中发生的分子和细胞变化，(2) 运营研究实验室，以及 (3) 启动和发展独立研究事业的指导。 还确定了合作者来指导凯尔分离原代成年心肌细胞 为执行和解释代谢组分析提供帮助。 丙酮酸的代谢对于心脏的工作至关重要，心脏需要大量的 ATP 来提供能量 收缩。在心脏缺血、肥厚或糖尿病期间，丙酮酸代谢显着减少。 然而，这些代谢改变的机制尚不清楚。活动监管 新发现的线粒体丙酮酸载体（MPC）可能在这些适应中发挥了作用。然而， 关于心脏 MPC 的调节或致病条件如何相关尚不清楚 丙酮酸利用受损会影响 MPC 活性。这项工作的目标是：（1）确定 缺血、肥厚和糖尿病心肌病期间 MPC 复合物的乙酰化状态和活性， (2) 鉴定负责修饰 MPC 蛋白的脱乙酰酶，(3) 鉴定乙酰化赖氨酸残基 MPC2，(4) 表型表征心脏特异性 MPC2-null 的心脏功能和代谢 (CS-MPC2-/-)小鼠，(5)分析CS-MPC2-/-小鼠对糖尿病、肥大和缺血的反应。 该提案的总体目标是将麦科米斯博士培养成一名富有成效的独立调查员。 从拟议的研究和职业发展计划中获得的知识和经验将 为他提供成为一名卓有成效的独立调查员所需的推动力并获得 R01 类资金。

Abstract In this K99/R00 Pathway to Independence award application, Dr. Kyle McCommis outlines detailed plans to enhance his research training in state-of-the-art cardiovascular metabolism techniques while simultaneously addressing a novel mechanism to altered metabolism during various cardiomyopathies. Dr. McCommis is currently a postdoctoral research scholar at the Washington University School of Medicine, and has a strong background in assessing cardiac function, and the role of mitochondria in cardioprotection. Kyle’s recent research training delved into hepatic and β-cell mitochondrial pyruvate metabolism. Herein, he seeks to marry these two areas of research expertise to investigate the importance of mitochondrial pyruvate metabolism in the heart. A primary goal of Dr. McCommis is to become an independent investigator in cardiometabolic research, thus a career development plan has been proposed in which he will train with experts in various aspects of cardiac metabolism (Drs. Finck, Lewandowski, and Schaffer). From Dr. Lewandowski he will learn: (1) the isolated perfused mouse heart preparation, (2) expand upon Kyle’s experience using tracers to understand metabolic pathways, and (3) NMR analysis of tracer metabolite flux. From Drs. Finck and Schaffer, Kyle will learn: (1) the molecular and cellular alterations that occur in diabetic hearts, (2) the nuances of running a research laboratory, and (3) guidance on initiating and developing an independent research career. Collaborators have also been identified to instruct Kyle on the isolation of primary adult cardiomyocytes as well as provide assistance with performing and interpreting metabolomic analyses. Metabolism of pyruvate is essential for the working heart which requires large amounts of ATP to fuel contraction. During cardiac ischemia, hypertrophy, or diabetes, pyruvate metabolism is significantly diminished. However, the mechanisms of these metabolic alterations are far from understood. Regulation of the activity of the newly identified mitochondrial pyruvate carrier (MPC) likely plays a role in these adaptations. However, nothing is known regarding the regulation of the MPC in the heart or how pathogenic conditions associated with impaired pyruvate utilization affects MPC activity. The goals of this work are to: (1) determine the acetylation status and activity of the MPC complex during ischemia, hypertrophy, and diabetic cardiomyopathy, (2) identify the deacetylase responsible for modifying MPC proteins, (3) identify the acetylated lysine residue(s) of MPC2, (4) phenotypically characterize the cardiac function and metabolism of cardiac-specific MPC2-null (CS-MPC2-/-) mice, and (5) analyze the response of CS-MPC2-/- mice to diabetes, hypertrophy, and ischemia. The overarching goal of this proposal is to develop Dr. McCommis into a productive independent investigator. The knowledge and experience obtained from the proposed research and career development plans will provide him the boost he needs to become a fruitful independent investigator and secure R01-type funding.