GROWTH-DEPENDANT REGULATION OF LIPID AUTACOID PRODUCTION

脂质类脂产生的生长依赖性调节

• 批准号: 3472850
• 负责人: RALPH E WHATLEY
• 金额: $ 11.63万
• 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/3472850
• 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 依赖生长的二十烷基类化合物和血小板激活因子的生产 通过内皮细胞。花生四烯酸的代谢物有多种，有效 生理和病理生理效应，并可能在 许多疾病的过程，包括血管疾病。激活血小板 因子(1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine；PAF)是独一无二的 能有效激活血小板和中性粒细胞的磷脂 显著的血液动力学效应。内皮细胞产生这种脂类 细胞可能是一种将炎性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，如果不适当的话 调节的，作为病理性血管损伤的介体。 内皮细胞产生这些有效的脂质介质 细胞受到严格的监管，似乎有许多共同的特征，但 我们对这种监管机制的理解是不完整的。这个 这个项目的具体目标是。描述细胞机制 通过细胞外刺激引起花生四烯酸的释放和 PAF的产生和这些类脂类化合物在 不同的生长状态。对这两种脂质都进行研究是合适的 因为在内皮细胞中花生四烯酸的释放 对同样的刺激反应会导致产生 血小板活化因子。此外，合成的第一步 花生四烯酸代谢产物和血小板活化因子 由磷脂酶A2催化。 这些研究将利用培养的人类血管内皮细胞 脐静脉和牛肺动脉。之所以选择这些，是因为 这些细胞在培养过程中的特性和反应良好。 在我的实验室里建立的。这些响应包括以下能力 释放花生四烯酸并产生PAF以响应特定的介体， 包括荷尔蒙刺激。重要的是，这些细胞表现出 不同温度下花生四烯酸释放和PAF生成的变化规律 文化发展的各个阶段。这是一个非常有用的特征 我将利用它来确定调节生产的机制 这两种重要的脂类。我将研究以下几种机制： 这些过程中可能涉及的信号转导和 调控花生四烯酸释放和释放的细胞内调控机制 PAF生产。这些研究将具体讨论 蛋白激酶C、细胞外钙内流、细胞内变化 钙离子浓度和磷脂酶C活性在调节生产中的作用 并释放这些脂质介体。此外，由于这些变化， 在不同生长状态下发生的脂质合成中，相关研究 将研究这些脂质作为自分泌调节剂的潜在作用 细胞生长。