Importance and Regulation of Cardiac Mitochondrial Pyruvate Transport

摘要 在这份K99/R 00独立之路奖的申请中，凯尔·麦克科米斯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训练，同时 提出了在各种心肌病期间改变代谢的新机制。麦柯米斯博士是 目前是华盛顿大学医学院的博士后研究学者，并具有很强的 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细胞线粒体丙酮酸代谢。在此，他想娶 这两个研究领域的专业知识，以调查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的独立研究者。 因此，他提出了一个职业发展计划，在这个计划中，他将与各方面的专家进行培训。 心脏代谢方面（Finck，Lewandowski和Schaffer博士）。从莱万多夫斯基博士那里，他将学到： (1)离体灌流小鼠心脏制备，（2）扩展凯尔的经验，使用示踪剂， 了解代谢途径，和（3）示踪代谢物通量的NMR分析。来自芬克和谢弗医生 凯尔将学习：（1）发生在糖尿病心脏的分子和细胞改变，（2） 管理研究实验室;（3）指导开展和发展独立的研究事业。 还确定了指导凯尔分离原代成体心肌细胞的合作者 为执行和解释代谢组学分析提供帮助。 丙酮酸的代谢对于需要大量ATP来提供能量的工作心脏是必不可少的 收缩。在心脏缺血、肥大或糖尿病期间，丙酮酸代谢显著减少。 然而，这些代谢改变的机制远未被理解。的活性调节 新鉴定的线粒体丙酮酸载体（MPC）可能在这些适应中起作用。然而，在这方面， 关于MPC在心脏中的调节或致病条件如何与心脏疾病相关， 丙酮酸利用受损影响MPC活性。本工作的目标是：（1）确定 在缺血、肥大和糖尿病性心肌病期间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 （4）表征心脏特异性MPC 2缺失的心脏功能和代谢的表型特征 （5）分析CS-MPC 2-/-小鼠对糖尿病、肥大和局部缺血的反应。 该提案的总体目标是将McCommis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 为他提供他需要成为一个富有成效的独立调查员和安全的R 01型资金的推动。

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.