The physiologic and genomic relevance of mitoregulin in ischemic heart failure

线粒体调节蛋白在缺血性心力衰竭中的生理学和基因组相关性

基本信息

批准号：
10439507
负责人：
RYAN L BOUDREAU
金额：
$ 38.63万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10439507
关键词：
3&apos Untranslated Regions Acute Address Affect American Apoptosis Apoptotic Area Bioinformatics Biological Biology Blood flow Buffers Calcium Cardiac Cardiac Myocytes Cell Death Cell model Cells Cessation of life Clinical Data Complex DNA Development Event Follow-Up Studies Future Gene Proteins General Population Genetic Genetic Diseases Genetic Markers Genetic Variation Genomics Genotype Goals Grant Healthcare Systems Heart Heart failure Hela Cells Human Human Genetics Hypoxia In Vitro Incidence Inner mitochondrial membrane Ischemia Knowledge Link Membrane Membrane Potentials Messenger RNA Metabolic Mitochondria Molecular Morbidity - disease rate Mus Myocardial Infarction Myocardial Ischemia Myocardium Names Necrosis Outcome Oxidative Stress Pathway interactions Patient-Focused Outcomes Patients Permeability Physiological Physiology Play Predisposing Factor Prevalence Production Proteins Publishing RNA RNA-Binding Proteins Reactive Oxygen Species Regulation Reperfusion Injury Reperfusion Therapy Respiration Risk Risk Factors Rodent Rodent Model Role Sampling Testing Tissues Translating Treatment Failure Untranslated RNA Up-Regulation Variant Woman Work adverse outcome biological adaptation to stress cardioprotection cohort cost genetic variant high risk improved ischemic cardiomyopathy knock-down loss of function men mitochondrial membrane mitochondrial permeability transition pore mortality multidisciplinary novel therapeutics overexpression prevent protein protein interaction public health relevance respiratory response restoration

项目摘要

PROJECT SUMMARY / ABSTRACT Myocardial infarction (MI) is a primary cause of morbidity and mortality worldwide. Although reperfusion therapy improves post-MI survival, the rapid restoration of oxygenated blood flow to the heart elicits oxidative stress that further damages tissue, known as ischemia-reperfusion (IR) injury, exacerbating one’s risk for developing heart failure (HF). Central to IR injury are mitochondria, which play key roles in cardiomyocyte Ca2+ buffering and production of energy and reactive oxygen species (ROS). Upon IR, mitochondrial Ca2+ overload and ROS trigger mitochondrial permeability transition (mPT) pore opening, which promotes cell death. While many studies highlight the critical role of mPT in IR injury and cardioprotection, many molecular pathways leading to altered mitochondrial Ca2+ and ROS (key upstream regulators of mPT) remain poorly defined. In recent work, we discovered that a heart- and muscle- enriched long, “non-coding” RNA actually does encode for a highly-conserved single-pass transmembrane micro- protein that localizes to the inner mitochondrial membrane; we named this protein “Mitoregulin” (Mtln). In gain- and loss-of-function studies, we found that Mtln “supercharges” mitochondria by increasing their 1) respiratory super- complex levels, 2) respiratory efficiencies, and 3) Ca2+ retention capacities, while reducing ROS. In this grant, we propose Aims to address two central hypotheses: 1) that Mtln protects against cardiac IR injury by delaying Ca2+- and ROS-triggered mPT, and 2) that human genetic variation linked to Mtln expression associate with HF patient outcomes. Our overarching goal is to translationally link Mtln with cardiac IR injury and HF outcomes to justify a need for future studies to continue defining Mtln’s precise modes of action. In Aim 1, we will define the physiologic and molecular functions of Mtln in cardiomyocytes by evaluating the acute effects of modulating Mtln expression on mitochondrial respiration, Ca2+ and ROS, as well as supercomplex levels in cultured rodent cardiomyocytes. We will also define Mtln domains and protein interactions necessary for its function. In Aim 2, we will elucidate a role for Mtln in cell and rodent models of IR injury and HF through gain- and loss-of-function studies to evaluate the impact of Mtln modulation on cardiomyocyte death induced by simulated IR, as well as on responses to cardiac IR injury and ensuing HF in mice. In Aim 3, we will work to establish links among genetic variants, cardiac Mtln expression, and HF patient outcomes, focusing on the biological and genetic relevance of a 36-bp 3’UTR deletion variant (Mtln-3’UTRdel) that is present in 12% of the general population and is known to be linked to decreased Mtln mRNA levels in heart tissues. We will identify RNA-binding proteins that control Mtln expression and assess the impact of the 3’UTRdel variant on this regulation and on Mtln protein levels in human hearts. We will also test available DNA samples linked to clinical data in patient cohorts to assess the association of Mtln-3’UTRdel genotypes with HF incidence and outcomes (e.g. mortality and arrhythmic events). These multi-disciplinary studies have significant potential to 1) transform our knowledge of basic mitochondrial biology, 2) determine if Mtln represents a viable target for HF therapy, and 3) reveal new genetic markers that could translate towards improved identification and treatment of high-risk HF patients.

项目摘要 /摘要心肌梗塞（MI）是全球发病率和死亡率的主要原因。虽然再灌注疗法改善了MI后的生存，氧化血流的快速恢复引起了氧化应激进一步损害组织，称为缺血 - 灌注（IR）损伤，加剧了心力衰竭的风险（HF）。 IR损伤的中心是线粒体，它在心肌细胞CA2+缓冲和生产中起关键作用能量和活性氧（ROS）。在IR上，线粒体Ca2+过载和ROS触发线粒体渗透性过渡（MPT）孔口开口，可促进细胞死亡。许多研究强调了关键作用 MPT在IR损伤和心脏保护方面，许多分子途径导致线粒体Ca2+和ROS改变（MPT的关键上游调节器）定义很差。在最近的工作中，我们发现心脏和肌肉 - 富含长的“非编码” RNA实际上确实编码了高度保存的单次跨膜微神经定位在线粒体膜内的蛋白质；我们将此蛋白质命名为“线索指导蛋白”（MTLN）。在增益和功能丧失研究，我们发现MTLN通过增加线粒体“增压”线粒体1）复杂水平，2）呼吸效率和3）CA2+保留能力，同时降低ROS。在这笔赠款中，我们提案旨在解决两个中心假设：1）MTLN通过延迟Ca2+和 ROS触发的MPT和2）与HF患者相关的MTLN表达相关的人类遗传变异结果。我们的总体目标是将MTLN与心脏IR损伤和HF结果联系起来，以证明需要为了使未来的研究继续定义MTLN的精确行动方式。在AIM 1中，我们将定义生理学和 MTLN在心肌细胞中MTLN的分子功能通过评估调节MTLN表达对急性影响线粒体呼吸，Ca2+和ROS，以及培养的啮齿动物心肌细胞中的超复合水平。我们将还定义了MTLN域和其功能所需的蛋白质相互作用。在AIM 2中，我们将阐明MTLN的角色通过增益和功能丧失研究，在IR损伤和HF的细胞和啮齿动物模型中评估MTLN的影响对模拟IR引起的心肌细胞死亡的调节以及对心脏IR损伤的反应并确保小鼠的HF。在AIM 3中，我们将努力在遗传变异，心脏MTLN表达和HF患者之间建立联系结果，重点是36 bp 3’utr缺失变体的生物学和遗传相关性（mtln-3’utrdel）存在于12％的一般人群中，并且已知与心脏组织中MTLN mRNA水平降低有关。我们将确定控制MTLN表达的RNA结合蛋白，并评估3'utrdel变体对这种调节和人类心脏中的MTLN蛋白水平。我们还将测试与临床相关的可用DNA样品患者队列中的数据评估MTLN-3’UTRDEL基因型与HF事件和结果的关联（例如死亡率和心律失常事件）。这些多学科研究具有重要的潜力1）改变我们的基本线粒体生物学的知识，2）确定MTLN是否代表了HF治疗的可行靶标，3）揭示可以转化为改善高风险HF患者的鉴定和治疗的新遗传标记。