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最常见的死亡原因。潜在糖尿病的存在是心脏病进展的最大危险因素。在当前的拨款间隔内，我们有发现了以前未知的脂质代谢途径和信号分子，导致产生类二十烷酸-溶血磷脂。值得注意的是，心肌中的绝大多数类二十烷酸被发现是酯化至溶血磷脂的甘油主链。此外，在野生型中诱导 I 型糖尿病小鼠或离体野生型小鼠心脏的缺血性损伤导致促炎性物质急剧增加类二十烷酸-溶血磷脂。这种新型磷脂通过诱导炎症介质发挥作用单核细胞或巨噬细胞释放 TNFa。重要的是，iPLA2g (PNPLA8) 的基因消融在糖尿病状态下，显着降低心肌中类二十烷酸-溶血磷脂的水平，心肌缺血并协同减少其在糖尿病心肌缺血中的合成。因此，我们认为 iPLA2g 在糖尿病心脏的病理生理发展中发挥核心作用疾病并促进糖尿病心肌病的致命后遗症。在具体目标 1 中，我们将利用稳定的对来自基因工程心肌细胞特异性的分离的灌注小鼠心脏进行同位素标记我们已经生成了条件性 iPLA2g 基因敲除小鼠。这些研究将调查 iPLA2g 在代谢通量： 1) 非酯化和酯化类二十烷酸； 2) 类二十烷酸-溶血磷脂； 3）其他突出的氧化磷脂。稳定同位素脉冲追踪实验以及深入的生物信息学分析将确定通过这些新发现的途径的代谢通量率。从翻译上来说，我们将探讨 2 型糖尿病对心肌缺血损伤的影响以及缺血性损伤的潜在补救措施我们设计的心肌细胞特异性 iPLA2g KO 小鼠的心肌。分析终点包括梗塞 iPLA2g 的大小、血流动力学性能和翻译后修饰。在具体目标 2 中，我们将利用我们制备了心肌细胞特异性 iPLA2b KO 小鼠，以探索 iPLA2b 在促进 II 型糖尿病背景下 WT 与 iPLA2b KO 小鼠的心肌缺血损伤和心律失常。下一个，我们将确定 iPLA2b 催化酰基转移酶或转酰基酶介导的再酯化的能力类二十烷酸-溶血磷脂产生氧化磷脂，这与损伤有关相关的分子模式。在具体目标 3 中，高脂肪饮食诱发的机制将研究伴随炎症和线粒体功能障碍的类二十烷酸-溶血脂合成。这溶血磷脂酶在调节类二十烷酸-溶血磷脂水平中的作用及其激活机制 iPLA2g 将接受检查。总的来说，拟议的研究将确定 iPLA2g 和 iPLA2b 的重要性介导新发现的类二十烷酸-溶血磷脂合成和代谢途径确定它们对糖尿病心肌病和糖尿病心脏急性缺血性损伤的影响。