Interplay between mitophagy and substrate utilization in heart failure progression

线粒体自噬和底物利用在心力衰竭进展中的相互作用

• 批准号: 10534749
• 负责人: Nuo Sun
• 金额: $ 52.33万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-06 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10534749
• 关键词: Adult; Affect; Attenuated; Bioenergetics; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cardiovascular Physiology; Cardiovascular system; Carnitine Palmitoyltransferase I; Deubiquitinating Enzyme; Deubiquitination; Development; Energy Metabolism; Exhibits; Fatty Acids; Genes; Genetic; Glucose; Goals; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Homeostasis; Human; Impairment; In Vitro; Inner mitochondrial membrane; Intervention; Kinetics; Knock-out; Knowledge; Link; Lysosomes; Mediating; Metabolic; Metabolism; Mitochondria; Mitochondrial Membrane Protein; Modeling; Molecular; Mus; Myocardial; Nuclear; Outer Mitochondrial Membrane; PINK1 gene; PTEN gene; Parkin; Pathologic; Pathway interactions; Peptide Hydrolases; Phenotype; Phosphotransferases; Physiological; Play; Production; Proteins; Quality Control; Reaction; Reagent; Regulation; Research; Research Proposals; Role; Signal Pathway; Stress; Testing; Therapeutic; Tissues; Ubiquitin; Ubiquitination; cardioprotection; carnitine palmitoyltransferase 2 deficiency; functional decline; gain of function; genetic analysis; heart function; improved; in vivo; in vivo monitoring; induced pluripotent stem cell; inhibitor; innovation; insight; long chain fatty acid; mitochondrial dysfunction; mitochondrial metabolism; mouse model; novel; novel therapeutic intervention; oxidation; pharmacologic; premature; presenilin; preservation; pressure; programs; receptor; response; rhomboid; spatiotemporal; therapeutic target; treatment strategy; ubiquitin isopeptidase; ubiquitin-protein ligase

PROJECT SUMMARY Mitochondrial dysfunction and altered mitochondrial metabolism have been implicated in the development of heart failure (HF). Mitophagy is a specialized autophagic pathway that mediates the lysosome-dependent clearance of damaged mitochondria, and is essential for mitochondrial quality control. However, our current knowledge regarding mitophagy in the heart and how it relates to myocardial metabolism is limited. Under normal conditions, the heart relies predominantly on fatty acid β-oxidation (FAO) to fuel ATP production. In contrast, a failing or hypertrophied heart usually shows impaired FAO and increased reliance on glucose utilization. Despite significant advancements in understanding the regulatory programs that attenuate FAO, it is unclear how shifts in myocardial substrate utilization contribute to the regulation of mitophagy. Therefore, this research proposal focuses on the functional significance of cardiac mitophagy in response to altered myocardial substrate utilization that occurs, for instance, in the setting of impaired FAO. The goal of this project is to delineate the novel mechanistic link between mitophagy and myocardial substrate utilization in the heart, as well as to determine whether mitophagy represents a novel mechanism and therapeutic target for the treatment of heart disease. These studies will be facilitated by our recently described mt-Keima mouse model to monitor in vivo cardiac mitophagy, as well as a set of innovative reagents to genetically and pharmacologically modulate mitophagic flux. To directly assess the role of FAO in the heart, we have generated mice with cardiomyocyte-specific deletion of CPT2 (CPT2-cKO), encoding a single gene required for FAO. We have demonstrated a decline in mitophagy precedes the development of impaired cardiac function in FAO-deficient hearts. Our genetic analyses suggest cardiac CPT2 deletion impairs the PTEN-induced putative kinase 1 (PINK1) signaling pathway, which positively regulates mitophagy through mitochondrial ubiquitination. Augmentation of mitophagy by modulating USP30, which mediates the reverse reaction, deubiquitination on mitochondria, mitigates the functional decline in FAO deficient hearts. Therefore, in Aim 1 of the proposed studies, our goal is to define the magnitude and Kinetics of cardiac mitophagy in response to impaired FAO, as well as to dissect the underlying molecular mechanisms connecting mitophagy to myocardial substrate utilization. In Aim 2 of the proposed studies, we will genetically and pharmacologically manipulate USP30 enzymatic function in the heart using mouse models that lack USP30 or are treated with a novel USP30 inhibitor. We will determine whether the detrimental cardiac phenotype, induced by cardiac CPT2 deletion or pressure overload, could be reversed, at least partially, by restoring mitophagy in cardiomyocytes via the inhibition of USP30. Completion of the proposed studies will produce critical insights into the role of mitophagy in normal cardiovascular physiology and in pathological conditions, and will fundamentally advance our understanding of the interaction between mitochondrial metabolism and mitochondrial quality control in the heart.

项目摘要 线粒体功能障碍和线粒体代谢改变已在发育中暗示 心力衰竭（HF）。线粒体是一种专门的自噬途径，可介导溶酶体依赖性 线粒体损坏的清除，对于线粒体质量控制至关重要。但是，我们的当前 在正常了解的情况下，关于心脏中的线粒体及其与心肌代谢的关系有限。 条件，心脏主要依靠脂肪酸β-氧化（FAO）来燃料产生ATP。相反， 失败或肥大的心脏通常显示出粮农组织受损并增加了葡萄糖利用率的保留率。尽管 在理解减弱粮农组织的监管计划方面的重大进步，目前尚不清楚如何转变 在心肌底物中，利用率有助于线粒体的调节。因此，这项研究建议 重点关注心脏线粒体的功能意义，以响应改变的心肌底物利用率 例如，在粮农组织受损的情况下发生。该项目的目的是描绘小说 线粒体和心肌底物利用率之间的机械联系，并确定 线粒体是否代表了治疗心脏病的一种新型机制和治疗靶标。 这些研究将由我们最近描述的MT-Keima小鼠模型准备，以监测体内心脏 线粒体以及一组创新的试剂，用于遗传和药物调节线粒体 通量。为了直接评估粮农组织在心脏中的作用，我们已经产生了具有心肌细胞特异性缺失的小鼠 CPT2（CPT2-CKO），编码FAO所需的单个基因。我们已经证明了线粒体的下降 在粮农组织缺陷心脏中心脏功能受损的发展之前。我们的遗传分析表明 心脏CPT2删除会损害PTEN诱导的假定激酶1（PINK1）信号通路，该途径积极 通过线粒体泛素化​​来调节线粒体。通过调节USP30来增加线粒体 介导反应的反应，即线粒体上的去泛素化，减轻了粮农组织的功能下降 防御性的心。因此，在拟议的研究的目标1中，我们的目标是定义 心脏线索响应粮农组织受损，并剖析了基本的分子机制 将线粒体连接到心肌底物利用率。在拟议研究的目标2中，我们将一般 并使用缺乏USP30的鼠标在心脏中操纵USP30酶促功能 或用新型的USP30抑制剂治疗。我们将确定是否有害心脏表型， 通过心脏CPT2删除或压力超负荷诱导的 通过抑制USP30，心肌细胞的线粒体。拟议研究的完成将产生关键 深入了解线粒体在正常心血管生理和病理状况中的作用，并将 从根本上讲，我们对线粒体代谢与 心脏中的线粒体质量控制。