Regulation of Myocardial Phospholipases and Lipases in Diabetic Myocardium

糖尿病心肌中心肌磷脂酶和脂肪酶的调节

基本信息

批准号：
10367196
负责人：
RICHARD W GROSS
金额：
$ 78.56万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-06-01 至 2026-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10367196
关键词：
12-HETE Ablation Acute Acyl Coenzyme A Acyltransferase Ankyrin Repeat Arrhythmia Binding Bioinformatics C-terminal Calmodulin Calpain Cardiac Myocytes Catalytic Domain Cause of Death Complex Crystallization Developed Countries Development Diabetes Mellitus Dissection Eicosanoids Engineering Esterification Generations Genetic Genetic Engineering Genetic Transcription Glycerol Grant Heart Heart Diseases High Fat Diet Holoenzymes Hydrolysis Hydroxyeicosatetraenoic Acids IL8 gene In Vitro Industrialization Infarction Inflammation Inflammation Mediators Inflammatory Insulin-Dependent Diabetes Mellitus Ischemia Knock-out Knockout Mice Lead Ligands Lipase Lipids Lysophospholipase Lysophospholipids Mass Spectrum Analysis Mediating Metabolic Metabolic Pathway Metabolism Modeling Molecular Mus Myocardial Myocardial Infarction Myocardial Ischemia Myocardium Non-Insulin-Dependent Diabetes Mellitus Oxides Pathologic Pathway interactions Pattern Performance Phospholipase Phospholipids Phosphorylation Physiologic pulse Plasmalogens Play Post-Translational Protein Processing Production Protein Isoforms Proteolysis Proteolytic Processing Regulation Research Resolution Risk Factors Roentgen Rays Role Signal Pathway Signal Transduction Signaling Molecule Site Societies Specificity Stable Isotope Labeling Sterility Structure TLR4 gene Tissues Transacylase Transgenic Mice Type 2 diabetic Vertebral column Wild Type Mouse acylcarnitine calmodulin-dependent protein kinase II comorbidity diabetic diabetic cardiomyopathy diabetic patient experimental study hemodynamics in vivo insight interest macrophage metabolic rate mitochondrial dysfunction monocyte mu-calpain nanomolar preference prevent receptor stable isotope transacylation type I and type II diabetes

项目摘要

ABSTRACT Heart disease is the most common cause of death in industrialized nations. The presence of underlying diabetes is the greatest risk factor for the progression of heart disease. During the current grant interval, we have discovered previously unknown lipid metabolic pathways and signaling molecules which lead to the generation of eicosanoid-lysophospholipids. Remarkably, the vast majority of eicosanoids in myocardium were found to be esterified to the glycerol backbone of lysophospholipids. In addition, induction of Type I diabetes in wild-type mice or ischemic damage in isolated wild-type mouse hearts resulted in dramatic increases in pro-inflammatory eicosanoid-lysophospholipids. This new class of phospholipids serve as inflammatory mediators by inducing the release of TNFa from monocytes or macrophages. Importantly, genetic ablation of iPLA2g (PNPLA8) substantially decreased the levels of eicosanoid-lysophospholipids in myocardium in the diabetic state, during myocardial ischemia and synergistically decreased their synthesis in diabetic myocardium rendered ischemic. Accordingly, we propose that iPLA2g plays a central role in the pathophysiologic development of diabetic heart disease and promotes the lethal sequelae of diabetic cardiomyopathy. In Specific Aim 1, we will utilize stable isotope labeling of isolated perfused mouse hearts from genetically engineered cardiac myocyte-specific conditional iPLA2g knockout mice we have generated. These studies will investigate the roles of iPLA2g in the metabolic flux of: 1) non-esterified and esterified eicosanoids; 2) eicosanoid-lysophospholipids; and 3) other salient oxidized phospholipids. Stable isotope pulse-chase experiments followed by penetrating bioinformatic analyses will determine rates of metabolic flux through these newly discovered pathways. Translationally, we will explore the impact of Type 2 diabetes on myocardial ischemic damage and the potential salvage of ischemic myocardium in cardiac myocyte-specific iPLA2g KO mice we engineered. Endpoints of analysis include infarct size, hemodynamic performance, and post-translational modifications of iPLA2g. In Specific Aim 2, we will utilize cardiac myocyte-specific iPLA2b KO mice we have generated to explore the role of iPLA2b in promoting myocardial ischemic damage and arrhythmias in WT vs. iPLA2b KO mice in the context of Type II diabetes. Next, we will determine the ability of iPLA2b to catalyze acyltransferase or transacylase mediated re-esterification of eicosanoid-lysophospholipids to generate oxidized phospholipids which have been implicated in damage associated molecular patterns. In Specific Aim 3, the mechanisms through which a high fat diet induces eicosanoid-lysolipid synthesis accompanied by inflammation and mitochondrial dysfunction will be studied. The roles of lysophospholipases in modulating eicosanoid-lysophospholipid levels and activation mechanisms for iPLA2g will be examined. Collectively, the proposed studies will establish the significance of iPLA2g and iPLA2b in mediating the newly identified pathways of eicosanoid-lysophospholipid synthesis and metabolism and determine their impact on diabetic cardiomyopathy and acute ischemic damage in diabetic hearts.

抽象的心脏病是工业化国家中最常见的死亡原因。潜在糖尿病的存在是心脏病发展的最大危险因素。在当前的赠款间隔中，我们有发现了以前未知的脂质代谢途径和信号分子，这些途径导致产生 eicosanoid-淋巴磷脂。值得注意的是，发现心肌中的绝大多数类花生素是酯化为溶血磷脂的甘油主链。此外，野生型I型糖尿病的诱导孤立的野生型小鼠心脏中的小鼠或缺血损伤导致促炎的急剧增加类花生酸酯 - 糖磷脂。这类新的磷脂通过诱导从单核细胞或巨噬细胞中释放TNFA。重要的是，IPLA2G的遗传消融（PNPLA8）在糖尿病状态下，在心肌中，在心肌中，大大降低心肌缺血和协同降低其在糖尿病心肌中的合成性缺血。因此，我们建议IPLA2G在糖尿病心脏的病理生理发展中起着核心作用疾病并促进糖尿病心肌病的致命后遗症。在特定目标1中，我们将利用稳定来自基因工程性心肌细胞特异性的孤立灌注小鼠心脏的同位素标记我们已经生成的条件IPLA2G敲除小鼠。这些研究将研究IPLA2G在代谢通量的：1）未层化和酯化的eicosanoids； 2）类花生酸酯 - 糖磷脂； 3）其他明显的氧化磷脂。稳定的同位素脉冲追踪实验，然后穿透生物学分析将通过这些新发现的途径确定代谢通量的速率。翻译，我们将探索2型糖尿病对心肌缺血损伤的影响和缺血的潜在挽救我们设计的心肌心肌特异性IPLA2G KO小鼠的心肌。分析的终点包括梗塞 IPLA2G的大小，血液动力学性能和翻译后修饰。在特定目标2中，我们将使用心肌细胞特异性IPLA2B KO小鼠我们已经生成了探索IPLA2B的作用在II型糖尿病的背景下，WT与IPLA2B KO小鼠的心肌缺血损伤和心律不齐。下一个，我们将确定IPLA2B催化酰基转移酶或转囊地酶介导的重新酯化的能力类花生酸酯 - 糖磷脂产生氧化的磷脂，这些磷脂与损害有关相关的分子模式。在特定的目标3中，高脂饮食引起的机制将研究eicosanoid溶质膜合成，并伴有炎症和线粒体功能障碍。这溶物磷脂酶在调节类糖烷类糖磷脂水平和激活机制中的作用 IPLA2G将进行检查。总的来说，拟议的研究将确定IPLA2G和IPLA2B的重要性在介导eicosanoid-淋巴磷脂合成和代谢和代谢和代谢的新鉴定的途径中确定它们对糖尿病心脏中糖尿病心肌病和急性缺血性损害的影响。