GROWTH-DEPENDANT REGULATION OF LIPID AUTACOID PRODUCTION

脂质类脂产生的生长依赖性调节

• 批准号: 3472848
• 负责人: RALPH E WHATLEY
• 金额: $ 6.48万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3472848
• 关键词: arachidonate; biological signal transduction; calcium metabolism; cell growth regulation; growth /development; inflammation; inositol phosphates; intracellular; lipid biosynthesis; lipid disorder; lipid metabolism; lipids; phospholipase C; platelet activating factor; protein kinase C; tissue /cell culture

The goal of this project is to understand the mechanisms that regulate growth-dependent production of eicosanoids and platelet-activating factor by endothelial cells. Arachidonic acid metabolites have diverse, potent physiologic and pathophysiologic effects and may play important roles in many disease processes, including vascular disease. Platelet-activating factor (1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine; PAF) is a unique phospholipid that potently activates platelets and neutrophils and has dramatic hemodynamic effects. Production of this lipid by endothelial cells may be a mechanism to target inflammatory cells to an area of Injury. This may serve as a physiologic response to injury, or, if inappropriately regulated, as a mediator of pathologic vascular injury. The production of each of these potent lipid mediators by endothelial cells is tightly regulated and appears to have many common features, but our understanding of the mechanism of that regulation is incomplete. The specific aims of this project are to. characterize the cellular mechanisms by which extracellular stimuli cause release of arachidonic acid and production of PAF and an altered synthesis of these lipid autacoids at different growth states. It is appropriate to study both of these lipid mediators because in endothelial cells release of arachidonic acid occurs in response to the same stimuli that cause production of platelet-activating factor. In addition, the initial step for synthesis of both arachidonate metabolites and platelet-activating factor is catalyzed by a phospholipase A2. These studies will utilize cultured endothelial cells from human umbilical vein and bovine pulmonary artery. These have been chosen because the characteristics and responses of these cells in culture are well established in my laboratory. These responses include the ability to release arachidonate and produce PAF in response to specific mediators, including hormonal stimulation. Importantly, these cells demonstrate an altered regulation of arachidonate release and PAF production at different stages of growth in culture. This is an extremely useful characteristic that I will exploit to determine the mechanisms that regulate production of these two important lipids. I will examine several mechanisms for signal transduction that may be involved in these processes and the intracellular regulatory mechanisms that govern arachidonate release and PAF production. These studies will specifically address the roles of protein kinase C, extracellular calcium entry, changes in intracellular calcium concentration and phospholipase C activity in regulating production and release of these lipid mediators. In addition, because of the changes in lipid synthesis that occur at different growth states, related studies will examine the potential role of these lipids as autocrine regulators of cell growth.

这个项目的目标是了解调节 类花生酸和血小板活化因子的生长依赖性产生 通过内皮细胞。 花生四烯酸代谢物具有多样性， 生理和病理生理效应，并可能在 许多疾病过程，包括血管疾病。 血小板活化 1-O-烷基-2-乙酰基-sn-甘油-3-磷酸胆碱（PAF）是一种独特的 磷脂，有效激活血小板和中性粒细胞， 显著的血液动力学效应。 内皮细胞产生这种脂质 细胞可能是将炎症细胞靶向损伤区域的机制。 这可能是对损伤的生理反应，或者，如果不适当， 调节，作为病理性血管损伤的介质。 内皮细胞产生这些有效的脂质介质， 细胞受到严格的调控，似乎有许多共同的特点，但 我们对这种监管机制的理解是不完整的。 的 该项目的具体目标是。表征细胞机制 细胞外刺激引起花生四烯酸的释放， PAF的产生和这些脂质autacoids的合成改变， 不同的成长状态。 研究这两种脂质是合适的 因为在内皮细胞中花生四烯酸的释放发生 在对导致产生的相同刺激的反应中， 血小板活化因子 此外，合成的初始步骤 花生四烯酸代谢物和血小板活化因子的作用， 由磷脂酶A2催化。 这些研究将利用培养的内皮细胞从人类 脐静脉和牛肺动脉。 之所以选择这些，是因为 这些细胞在培养中的特性和反应良好， 建立在我的实验室里。 这些反应包括以下能力： 释放花生四烯酸并产生PAF， 包括荷尔蒙刺激。 重要的是，这些细胞表现出 不同时间花生四烯酸释放和PAF产生的调节改变 文化的成长阶段。 这是一个极其有用的特性 我将利用它来确定调节生产的机制 这两种重要的脂质。 我将研究几种机制， 可能参与这些过程的信号转导， 控制花生四烯酸释放的细胞内调节机制， PAF生产。 这些研究将具体探讨以下方面的作用： 蛋白激酶C，细胞外钙离子内流，细胞内钙离子浓度变化 钙离子浓度和磷脂酶C活性调节生产 以及这些脂质介质的释放。 此外，由于变化 在不同生长状态下发生的脂质合成中， 将研究这些脂质作为自分泌调节剂的潜在作用， 细胞生长