THE INTEGRATED ROLES OF IPLA2G IN OBESITY, INFLAMMATION AND HEPATIC DYSFUNCTION

IPLA2G 在肥胖、炎症和肝功能障碍中的综合作用

• 批准号: 8817361
• 负责人: RICHARD W GROSS
• 金额: $ 34.31万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-25 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8817361
• 关键词: 1,2-diacylglycerol; Ablation; Active Sites; Adipocytes; Affect; Animals; Attenuated; Bioenergetics; Biological Assay; Calcium; Cause of Death; Communication; Consumption; Coupling; Development; Diabetes Mellitus; Diagnostic; Diet; Diglycerides; Eicosanoids; Energy Metabolism; Euglycemic Clamping; Exhibits; Fatty Liver; Fatty acid glycerol esters; Functional disorder; Generations; Genetic; Genetic Models; Glucose Clamp; Glycerides; Goals; Hepatic; Hepatocyte; IRS1 gene; Inflammation; Inflammatory; Insulin Resistance; Knock-out; Knockout Mice; Lead; Lipids; Liver; Liver diseases; Mass Spectrum Analysis; Mediating; Mediator of activation protein; Metabolism; Metric; Mitochondria; Molecular; Monoglycerides; Morbidity - disease rate; Mus; Muscle Cells; Muscle Fibers; Obesity; Obesity associated disease; Organ; Organelles; Pathologic; Pathology; Patients; Phenotype; Phospholipase A2; Phosphorylation; Physiological; Process; Production; Protein Isoforms; Reagent; Research; Resistance; Respiration; Role; Signal Transduction; Skeletal Muscle; Societies; System; Technology; Tissues; Transgenic Organisms; Triglycerides; Validation; body system; cell type; feeding; glucose tolerance; glucose uptake; glycogenolysis; hepatic gluconeogenesis; human PLA2G6 protein; improved; in vivo; insight; insulin sensitivity; insulin signaling; interdisciplinary approach; lipid mediator; lipid metabolism; liver inflammation; loss of function; metabolomics; mitochondrial dysfunction; mortality; muscle metabolism; novel; novel strategies; obesity treatment; peroxisome; public health relevance; research study; screening; transacylation

DESCRIPTION (provided by applicant): The major causes of mortality and morbidity in industrialized societies result from the multiple downstream sequelae of high fat diet-induced obesity (HFDIO). Previously, we demonstrated the importance of calciumindependent phospholipase A2?(iPLA2?) as a central enzymic mediator integrating cellular signaling and organismal bioenergetics through the generation and characterization of a global iPLA2??KO mouse. Remarkably, the iPLA2??knockout mouse was completely resistant to HFDIO and the development of insulin resistance. However, due to the multiple organ systems affected in the whole animal iPLA2??knockout, the mechanistic roles of iPLA2??in each tissue contributing to the complete resistance of this mouse to HFDIO are unknown. The overarching goal of the proposed research is the mechanistic determination of the tissue- and Organelle-specific roles of iPLA2??in promoting inflammation, maladaptive cellular signaling and dysfunctional bioenergetics that result in insulin resistance and the pathologic end-organ sequelae of HFDIO. Accordingly, we generated mice containing a floxed construct of the iPLA2??active site which has been crossed with tissue specific Cre mice resulting in the generation of hepatocyte-specific and skeletal muscle myocyte-specific iPLA2??knockout mice. The proposed research will synergistically use these enabling genetic models in conjunction with the integrated lipidomics and metabolomics platforms we developed to identify the mechanisms through which iPLA2??participates in the development of obesity, inflammation, and insulin resistance during HFDIO. The first specific aim will identify the roles of hepatocyte-specific iPLA2??in mediating alterations in the generation of lipid 2nd messengers, lipid metabolism, hepatosteatosis and bioenergetics during HFDIO unencumbered by the effects of iPLA2??loss of function in other cell types that are present in the germline knockout. In Specific Aim 2, we will examine the effects of skeletal muscle myocyte-specific ablation of iPLA2??on skeletal muscle metabolism, insulin resistance and mitochondrial dysfunction that are present during high fat feeding in WT mice, but are rescued in the germline knockout mouse. Finally, in Specific Aim 3, we will determine the interactive mechanistic roles of the organelle-specific isoforms of iPLA2??through the transgenic reintroduction of either the mitochondrial-specific or peroxisomal-specific isoforms of iPLA2??into the hepatocyte-specific iPLA2??knockout mouse. Moreover, the mechanisms through which lipid 2nd messengers generated by iPLA2??in hepatocytes, skeletal muscle myocytes and adipocytes mediate inter-organ communication between these metabolically interwoven tissues will be identified through synergistic highly penetrating technologies we have developed/refined. Through this multidisciplinary approach employing novel genetic reagents, high mass accuracy mass spectrometry technologies and integrated chemophysiologic approaches, novel pharmacologic targets to attenuate the sequelae of HFDIO can be identified.

描述（由申请人提供）：工业化社会死亡率和发病率的主要原因是由于高脂饮食诱发的肥胖症（HFDIO）的多重下游后遗症所致。以前，我们通过全局IPLA2 ?? KO小鼠的生成和表征来综合细胞信号传导和有机生物能的中心酶介质，证明了钙独立磷脂酶A2？（IPLA2？）的重要性。值得注意的是，IPLA2敲除小鼠完全抵抗HFDIO和胰岛素抵抗的发展。但是，由于整个动物IPLA2敲除中的多个器官系统，IPLA2？在每个组织中的机械作用，导致该小鼠对HFDIO的完全抗性。拟议的研究的总体目标是组织和组织的机械确定 IPLA2 ??的细胞器特异性在促进炎症，适应不良的细胞信号传导和功能障碍的生物能学中，导致胰岛素抵抗和HFDIO的病理末期后遗症。因此，我们生成了含有IPLA2的flox构建体的小鼠，该构建体已与组织特异性CRE小鼠交叉，从而产生了肝细胞特异性和骨骼肌心肌细胞特异性ipla2？敲除小鼠。拟议的研究将协同使用这些有助于遗传模型与我们开发的综合脂肪组学和代谢组学平台结合使用，以确定IPLA2？参与HFDIO期间肥胖，炎症和胰岛素抵抗的机制。第一个具体目的将确定肝细胞特异性IPLA2？在脂质第二个使者，脂质代谢，肝固醇和生物能力中的介导变化中的作用。在特定目标2中，我们将研究IPLA2 ??骨骼肌特异性消融对骨骼肌代谢，胰岛素抵抗和线粒体功能障碍的影响，在WT小鼠的高脂喂养过程中存在，但在生殖线敲除小鼠中被解救。最后，在特定的目标3中，我们将通过对IPLA2的线粒体特异性或过氧化物酶体特异性同工型的转基因重新引入IPLA2？此外，IPLA2 ??在肝细胞，骨骼肌心肌细胞和脂肪细胞中通过这些代谢上互编的组织之间的脂质肌细胞和脂肪细胞介导的脂肪第二个使者的机制将通过我们开发的协同高度穿透性技术来鉴定。通过采用新型遗传试剂的这种多学科方法，可以鉴定出高质量准确性质谱技术和集成的化学生理方法，可以确定可以识别出新型的药理学靶标，以减轻HFDIO的后遗症。