GROWTH-DEPENDANT REGULATION OF LIPID AUTACOID PRODUCTION

脂质类脂产生的生长依赖性调节

• 批准号: 3472849
• 负责人: RALPH E WHATLEY
• 金额: $ 6.11万
• 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/3472849
• 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.

该项目的目标是了解调节机制 类二十烷酸和血小板激活因子的生长依赖性产生 由内皮细胞。 花生四烯酸代谢物具有多种、有效的 生理和病理生理效应，并可能在其中发挥重要作用 许多疾病过程，包括血管疾病。 血小板活化 因子（1-0-烷基-2-乙酰基-sn-甘油-3-磷酸胆碱；PAF）是一种独特的 磷脂可有效激活血小板和中性粒细胞，并具有 显着的血流动力学效应。 内皮细胞产生这种脂质 细胞可能是一种将炎症细胞靶向损伤区域的机制。 这可能是对伤害的生理反应，或者，如果不恰当的话 作为病理性血管损伤的调节因子。 内皮细胞产生这些有效的脂质介质 细胞受到严格调控，似乎有许多共同特征，但是 我们对该监管机制的理解并不完整。 这 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 的产生以及这些脂质自体物质的合成改变 不同的生长状态。 研究这两种脂质是合适的 介质，因为在内皮细胞中发生花生四烯酸的释放 响应导致产生的相同刺激 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激活因子的 由磷脂酶A2催化。 这些研究将利用来自人类的培养内皮细胞 脐静脉和牛肺动脉。 选择这些是因为 这些培养细胞的特征和反应很好 在我的实验室建立的。 这些响应包括能够 响应特定介质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 改变花生四烯酸释放和 PAF 产生的调节 文化的成长阶段。 这是一个非常有用的特性 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 这些过程中可能涉及的信号转导 控制花生四烯酸释放的细胞内调节机制 PAF 生产。 这些研究将专门探讨以下角色的作用： 蛋白激酶C、细胞外钙内流、细胞内变化 钙浓度和磷脂酶 C 活性在调节生产中的作用 以及这些脂质介质的释放。 另外，由于变化 在不同生长状态下发生的脂质合成中，相关研究 将检查这些脂质作为自分泌调节剂的潜在作用 细胞生长。