The role of the C1P/cPLA2-alpha interaction in eicosanoid biosynthesis.

C1P/cPLA2-α 相互作用在类二十烷酸生物合成中的作用。

• 批准号: 8716449
• 负责人: Lauren Alexis Hoeferlin
• 金额: $ 5.33万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-25 至 2016-03-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8716449
• 关键词: Agonist; Amino Acid Sequence; Amino Acids; Anabolism; Anti-Inflammatory Agents; Anti-inflammatory; Applications Grants; Arachidonic Acids; Binding; C2 Domain; Calcium; Cause of Death; Cells; Chemicals; Clinical Treatment; Clinical Trials; Cytosolic Phospholipase A2; Data; Disease; Docosahexaenoic Acids; Eicosanoids; Eicosapentaenoic Acid; Enzymes; Genetic Models; Immunoglobulin Class Switching; In Vitro; Infection; Inflammatory; Inflammatory Response; Injection of therapeutic agent; Ionophores; Knock-out; Knockout Mice; Laboratories; Leukotrienes; Lipids; Mediator of activation protein; Medical; Modeling; Mus; Mutagenesis; Pathogenesis; Pathway interactions; Patients; Phenotype; Phospholipase; Phospholipase A2; Phospholipids; Physiological; Production; Prostaglandins; Prostaglandins I; Proteins; Publishing; Reporting; Resistance; Role; Sepsis; Septic Shock; Septicemia; Site; Sphingolipids; Spontaneous abortion; Thromboxanes; Wild Type Mouse; base; ceramide 1-phosphate; cost; human PLA2G4A protein; in vivo; lipid mediator; mortality; novel; novel therapeutics; pre-clinical; public health relevance; research study; response; success

DESCRIPTION (provided by applicant): In this grant application, we are focusing on the physiologic condition of sepsis, which is a term used to describe a severe illness arising from serious infection. The mortality rate of sepsis is >215,000 patients a year, and sepsis is the tenth leading cause of death in the US. The estimated yearly cost for treating the 650,000 new cases of sepsis per year is ~17 billion dollars making this disease a very costly medical condition. Numerous clinical trials for the treatment of this disease have been undertaken, but unfortunately, these trials have shown limited success. As such, there is a major need for new therapeutics to treat the disease. The studies proposed in this grant application are directly related to sepsis as we are examining the biosynthetic pathways of 3-PUFA-derived lipid mediators and eicosanoids. The temporal and spatial production of these specialized chemical mediators actively controls the hyperactive inflammatory response as a result of sepsis. The synthesis of eicosanoids and the 3-PUFA-derived lipid mediators, eicosapentaenoic acid (EPA)-derived lipid mediators, begins with the initial rate-limiting step, the formation of arachidonic aid (AA) for eicosanoids or EPA for the EPA derived lipid mediators, via group IVA cytosolic phospholipase A2 (cPLA2?). Ceramide-1-phosphate (C1P) is a bioactive sphingolipid and a direct activator of cPLA2? both in vitro and in cells. Furthermore, published findings from the Chalfant lab demonstrated that mutagenesis of critical amino acids for the C1P interaction in cPLA2? inhibited the ability of enzyme to translocate in response to several inflammatory agonists. Hence, C1P is required for the activation of cPLA2?, and is a major regulator of eicosanoid synthesis in cells. To further our understanding of the physiological relevance of this lipid:protein interaction in vivo, our laboratory created a knockin mouse with the C1P interaction site of cPLA2? ablated. Our preliminary data has demonstrated some intriguing findings for this new genetic model of cPLA2?. For example, some phenotypes reported for the cPLA2? knockout mouse were not apparent in the cPLA2? knockin mouse (e.g. spontaneous abortion) (29), while other phenotypes were dramatically accentuated in the cPLA2? knockin mouse such as complete resistance to LPS and fecal-induced septic shock. Interestingly, the cPLA2? knockin mouse demonstrated higher levels of anti-inflammatory eicosanoids as well as increased induction of the anti-inflammatory E-resolvins in response to fecal injection as compared to the cPLA2? knockout and wild-type mice. Based on these data, we hypothesize that the cPLA2? knockin mouse is resistant to sepsis due to the sustained production of anti-inflammatory lipid mediators caused by a novel "lipid-class switch" in cPLA2? substrate utilization. Our proposed experiments will explore this hypothesis in depth both ex vivo and in vivo.

描述（由申请人提供）：在本赠款申请中，我们关注败血症的生理状况，该术语用于描述严重感染引起的严重疾病。败血症的死亡率每年> 215,000名患者，败血症是美国第十大死亡原因。每年治疗650,000例新败血症病例的估计每年成本约为170亿美元，使该疾病成为非常昂贵的医疗状况。已经进行了许多治疗该疾病的临床试验，但不幸的是，这些试验的成功有限。因此，新的治疗疗法的主要需求以治疗这种疾病。 当我们研究了3-PUFA衍生的脂质介质和类花生酸的生物合成途径时，本赠款应用中提出的研究与败血症直接相关。这些专业化学介质的时间和空间产生积极控制败血症导致的多动性炎症反应。 eicosanoids和3-PUFA衍生的脂质介质的合成，eicosapentaenoic（EPA）衍生的脂质介质的合成，始于初始速率限制步骤，即EPA衍生型脂肪层cy的初始速率限制步骤，eicosanoids or ecosanoids or epa cya cya cya cya （CPLA2？）。神经酰胺-1-磷酸盐（C1P）是生物活性鞘脂和CPLA2的直接激活剂？体外和细胞。此外，从Chalfant实验室发表的发现表明，CPLA2中C1P相互作用的临界氨基酸的诱变？抑制酶响应几种炎症激动剂而易位的能力。因此，C1P激活CPLA2需要，并且是细胞中类eicosanoid合成的主要调节剂。 为了进一步理解这一点的生理相关性 脂质：在体内蛋白质相互作用，我们的实验室与CPLA2的C1P相互作用位点创建了敲蛋白小鼠？消融。我们的初步数据证明了CPLA2的这种新遗传模型的一些有趣的发现。例如，某些表型报告了CPLA2？敲除鼠标在CPLA2中不明显吗？敲击小鼠（例如自发流产）（29），而其他表型在CPLA2中显着强调？敲击小鼠，例如完全抗LPS和粪便诱导的败血性休克。有趣的是，CPLA2？与CPLA2相比，敲击小鼠表现出更高水平的抗炎类花生酸酯以及增加抗炎电子溶质的诱导，以响应粪便注射？敲除和野生型小鼠。基于这些数据，我们假设CPLA2？由于CPLA2中新型的“脂质级开关”引起的抗炎脂质介质的持续产生，敲击小鼠对败血症具有抵抗力？基材利用率。我们提出的实验将在体内和体内深入探讨这一假设。