Importance and Regulation of Cardiac Mitochondrial Pyruvate Transport

摘要 在这份K99/R00独立之路奖申请中，Kyle McCommis博士概述了详细的计划 加强对最先进的心血管代谢技术的研究培训，同时 解决各种心肌病期间代谢改变的新机制。麦考米斯博士是 目前是华盛顿大学医学院的博士后研究学者，并拥有强大的 评估心脏功能的背景，以及线粒体在心脏保护中的作用。凯尔最近 研究培训深入研究了肝脏和β细胞线粒体丙酮酸的代谢。在这里，他试图嫁给 这两个领域的研究专门知识，以调查线粒体丙酮酸代谢的重要性 心脏。麦考米斯博士的主要目标是成为心脏代谢领域的独立研究员 研究，因此提出了一项职业发展计划，在该计划中，他将与各种领域的专家进行培训 心脏新陈代谢方面(芬克、莱万多夫斯基和谢弗博士)。他将从莱万多夫斯基博士那里学到： (1)分离的灌流小鼠心脏准备，(2)在Kyle使用示踪剂的经验基础上扩展以 了解代谢途径，以及(3)示踪代谢物通量的核磁共振分析。从芬克博士和谢弗博士那里， 凯尔将学到：(1)糖尿病心脏中发生的分子和细胞变化，(2)糖尿病心脏的细微差别 开办研究实验室；(3)指导开创和发展独立的研究事业。 也已确定合作者指导Kyle分离原代成年心肌细胞 为执行和解释代谢分析提供帮助。 丙酮酸的代谢对工作心脏是必不可少的，而工作心脏需要大量的三磷酸腺苷来补充能量 收缩。在心肌缺血、肥厚或糖尿病期间，丙酮酸代谢显著减弱。 然而，这些代谢变化的机制还远未被了解。对公司活动的监管 新发现的线粒体丙酮酸载体(MPC)可能在这些适应中发挥作用。然而， 关于心脏中MPC的调节或致病条件如何相关，目前尚不清楚。 受损的丙酮酸利用会影响MPC的活性。这项工作的目标是：(1)确定 缺血、肥大和糖尿病心肌病期间MPC复合体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(S) 在MPC2中，(4)表型表征心脏特异性MPC2缺失的心功能和代谢 (5)分析CS-MPC2-/-小鼠对糖尿病、肥大和缺血的反应。 这项提案的首要目标是将麦考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动力，并获得R01类型的资金。

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.