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：
8483030
负责人：
RICHARD W GROSS
金额：
$ 71.91万
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 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8483030
关键词：
Ablation Active Sites Acute Acyl Coenzyme A Acyltransferase Arachidonic Acids Attenuated Bioenergetics Biological Biological Assay Calcium Calcium ion Cardiac Cardiac Myocytes Cause of Death Cell membrane Cessation of life Charge Chemicals Chronic Coenzyme A-Transferases Complex Coupling Diabetes Mellitus Disease Eicosanoids Employee Strikes Endocannabinoids Energy Intake Enzymes Fatty Acids Fatty acid glycerol esters Functional disorder Generations Genetic Heart Heart Diseases Heart failure Homeostasis Hydrolysis Infarction Injury Ischemia Knock-out Knockout Mice Lead Lipase Lipids Lysophosphatidylcholines Lysophospholipase Lysophospholipids Mass Spectrum Analysis Mediating Mediator of activation protein Membrane Membrane Structure and Function Mitochondria Molecular Monoglycerides Mus Mutate Myocardial Myocardial Contraction Myocardial Ischemia Myocardium Necrosis Pathologic Pathway interactions Phospholipase Phosphorylation Phosphorylation Site Physiological Physiological Processes Production Protein Isoforms Proteins Regulation Reliance Reperfusion Therapy Role Serine Signal Transduction Signaling Molecule Site-Directed Mutagenesis Societies Stable Isotope Labeling Structure Sudden Death Testing Transacylase Transgenic Organisms Triglycerides Ventricular Arrhythmia calmodulin-dependent protein kinase II diabetic diabetic cardiomyopathy diabetic patient heart cell hemodynamics insulin signaling interdisciplinary approach loss of function lysophosphatidic acid metabolomics mitochondrial dysfunction mitochondrial permeability transition pore novel public health relevance transacylation

项目摘要

DESCRIPTION (provided by applicant): Diabetic cardiomyopathy is a complex disorder that emanates from the chronic and excessive use of fatty acids to fuel contractile function in diabetic myocardium due to the lack of insulin signaling. However, the nearly exclusive use of fatty acids for fuel in diabetic myocardium results in widespread metabolomic dysregulation that precipitates multiple deleterious alterations in membrane structure and function. Consequences of these membrane-mediated abnormalities in diabetic myocardium include hemodynamic compromise, defective excitation-contraction coupling and mitochondrial dysfunction that collectively conspire to promote the progression of heart failure in diabetic patients. Moreover, the profound alterations in substrate utilization in diabetic myocardium result in the accumulation of multiple dysregulated metabolites that lead to maladaptive alterations in interwoven cardiac myocyte signaling networks. Previously, through genetic, pharmacologic and chemical biological approaches, we have identified three major phospholipases and lipases in myocardium iPLA2? (PNPLA9), iPLA2? (PNPLA8), and iPLA2? (PNPLA2; ATGL) that likely serve as principal mediators of myocardial hemodynamic dysfunction, electrophysiologic alterations and maladaptive remodeling in diabetic myocardium. Recently, we demonstrated that iPLA2g and its downstream signaling metabolites are key regulators of the mitochondrial permeability transition pore which is responsible for necrosis, necroptosis, and electrical instability in diabetic myocardium subjected to ischemia. Accordingly, in Specific Aim 1, we will use the novel cardiac myocyte specific iPLA2g conditional knock out mouse we generated to determine if iPLA2g loss of function attenuates acute ischemic injury, electrophysiologic instability and the maladaptive generation of lipid 2nd messengers in diabetic myocardium. Furthermore, we demonstrated that exposure of mitochondria to calcium ion results in the activation of iPLA2g leading to the release of arachidonic acid, 2-arachidonoyl lysophosphatidylcholine, and the subsequent production of multiple downstream biologically active lipid 2nd messengers. Accordingly, iPLA2g-dependent alterations in lipid 2nd messenger production will be examined employing integrative mass spectrometric platforms we developed in conjunction with the cardiac myocyte specific iPLA2g loss of function mouse. In Specific Aim 2, we will determine the molecular mechanisms through which acyl-CoA facilitates CaMKII phosphorylation and activation of iPLA2b. The activating phosphosite(s) will be identified, mutated and their mechanistic importance in CaMKII-mediated activation of iPLA2b in diabetic myocardium and diabetic myocardium rendered ischemic will be explored. In Specific Aim 3, the role(s) of iPLA2z (ATGL;PNPLA2) in catalyzing the bidirectional flux of lipids through triglyceride hydrolysis, transacylation and acyltransferase activities will e determined. The participation of iPLA2z in generating lipid 2nd messengers in diabetic myocardium will be examined using cardiac myocyte specific iPLA2z null mice and the effects of iPLA2z genetic ablation on myocardial function in the diabetic state will be explored. Collectively, these studies are a synergistic multidisciplinary approach to identify the chemical mechanisms mediating diabetic cardiomyopathy.

描述（由申请人提供）：糖尿病性心肌病是一种复杂的疾病，它是由于缺乏胰岛素信号传导而源自慢性和过量使用脂肪酸来为糖尿病心肌促进收缩功能。但是，在糖尿病心肌中，几乎独有的脂肪酸用于燃料，导致广泛的代谢性失调，导致膜结构和功能的多种有害变化。这些膜介导的糖尿病心肌异常的后果包括血液动力学妥协，有缺陷的激发诱导偶联和线粒体功能障碍，共同促进糖尿病患者心脏衰竭的进展。此外，糖尿病心肌中底物利用的深刻变化导致积累多种失调的代谢产物，导致交织的心肌细胞信号网络的适应不良改变。以前，通过遗传学，药理和化学生物学方法，我们已经在心肌IPLA2中鉴定了三个主要的磷脂酶和脂肪酶？（PNPLA9），IPLA2？（PNPLA8）和IPLA2？（PNPLA2; ATGL）可能是心肌血液动力学功能障碍，电生理学改变和适应不良重塑的主要介体。最近，我们证明了IPLA2G及其下游信号代谢产物是线粒体通透性过渡孔的关键调节孔，该孔导致坏死，坏死性和糖尿病心肌的电不稳定。因此，在特定的目标1中，我们将使用新颖的心肌细胞特异性IPLA2G有条件敲除小鼠，以确定IPLA2G功能损失是否会减轻急性缺血性损伤，电生理学不稳定和糖尿病心脏中脂质第二递Mesgengers的疾病疾病的脂肪生成。此外，我们证明，线粒体暴露于钙离子会导致IPLA2G的激活，从而释放蛛网膜酸，2-芳基二烯酰基溶酶磷脂酰胆碱，并随后产生多个下游生物学活性的生物学活性的Lipid 2nd 2nd Messergers。因此，将检查脂质第二信使生产的IPLA2G依赖性变化，并采用我们与心肌细胞特异性IPLA2G功能鼠标相结合的综合质谱平台进行检查。在特定目标2中，我们将确定酰基辅酶A促进CaMKII磷酸化和IPLA2B激活的分子机制。将探讨，将探索激活磷材料，并将其在CAMKII介导的IPLA2B激活中的机理重要性中鉴定，在糖尿病心肌和糖尿病心肌呈现性缺血中的重要性。在特定的目标3中，IPLA2Z（ATGL; PNPLA2）的作用在通过甘油三酸酯水解，转囊化和酰基转移酶活性催化脂质的双向通量中的作用将确定。 IPLA2Z参与产生脂质第二使者在糖尿病心肌中的参与将使用心肌细胞特异性IPLA2Z NULL小鼠进行检查，以及IPLA2Z遗传消融对糖尿病状态中心肌功能的影响。总的来说，这些研究是一种协同的多学科方法，用于识别介导糖尿病心肌病的化学机制。