ROLE OF DIACYLGLYCEROL METABOLISM IN MAST CELL SECRETION

肥大细胞炎性介质的形成和释放 细胞在即刻超敏反应中发挥核心作用 并有助于慢性阻塞性肺疾病的发展和永久 哮喘等疾病中的炎症。的长期目标 这项工作是为了了解脂类代谢途径所起的作用 在特定的亚细胞中发挥作用，引起和/或 调节肥大细胞介质的释放。人们的注意力集中在 1，2-二酰基甘油(DAG)--一种脂肪中间体，可增加2-5 在生理刺激下折叠，参与调节 蛋白激酶C对蛋白质的磷酸化作用 花生四烯酸释放的底物和 融合脂类的形成在胞吐作用中具有潜在的重要作用。 研究DAG发病机制的新概念(S) 形成和消费都得到了发展。分子 测定了DAG的物种指纹图谱，发现其为 与磷脂酰肌醇(大多数人感觉到的脂肪)不一致 调查人员将导致DAG质量增加 细胞激活)强烈提示肥大细胞DAG 主要由其他途径形成。这一观察结果和 其他人强烈要求重新评估这些机制 在特定的亚细胞部位形成和移除DAG。目标1 建议定义相对重要性、位置和 1a对不同DAG发生途径的调控 在确定分子后使用演绎分析 推测的前体磷脂和磷脂的物种指纹 甘油三酯和1b)补充研究在体外检查 特异酶的活性、亚细胞定位和调控 感兴趣的人。因为任何中间体的混乱都是受控制的 不仅取决于它的形成速度，同样重要的是通过 它的去除率，AIM II试图确定亲属 特定DAG代谢途径的重要性及其位置 和监管。此问题的四种方法包括：2a) DAG代谢物的分子物种分析，2b)研究 原位生成或外源添加的DAG的代谢，2c) 确定推定的DAG代谢物的质量，和2d) 在体外直接评估合适的酶。 关于DAG性质和亚细胞定位的研究 新陈代谢--生化机制不可或缺的过程 监管调解人的释放-应该有助于更清晰地 免疫激活肥大细胞的观点。这一知识将会 有助于促进新药理的发展 过敏性疾病的治疗方法。

The formation and release of inflammatory mediators by mast cells play central roles in immediate hypersensitivity reactions and contribute to the development and perpetuation of chronic inflammation in diseases such as asthma. The long range goal of this work is to understand what roles lipid metabolic pathways play in specific subcellular compartments in causing and/or regulating mast cell mediator release. Attention is focused on 1,2-diacylglycerol (DAG) - a lipid intermediate that increases 2-5 fold with physiologic stimulation, participates in the regulation of phosphorylation of proteins by protein kinase C and acts as a substrate both for the release of arachidonic acid and the formation of fusogenic lipids potentially important in exocytosis. A new conceptual approach to study the mechanism(s) of DAG formation and consumption has been developed. The molecular species "fingerprint" of DAG was determined and found to be discordant with that of phosphatidylinositol (the lipid felt by most investigators to give rise to the increases DAG mass occurring in cellular activation) strongly suggesting that mast cell DAG is principally formed by other pathways. This observation and others strongly motivate a reassessment of the mechanisms that form and remove DAG in specific subcellular sites. Aim 1 proposes to define the relative importance, location and regulation of different DAG generative pathways by 1a) Employing deductive analysis after determining the molecular species fingerprints of putative precursor phospholipids and triglyceride and 1b) Complementary studies examining in vitro the activity, subcellular location and regulation of specific enzymes of interest. Because the mess of any intermediate is controlled not only by the rate of its formation, but equally importantly by its rate of removal, Aim II seeks to identify the relative importance of specific DAG metabolic pathways, their location and regulation. Four approaches this question include: 2a) Molecular species analysis of DAG metabolites, 2b) Studies of the metabolism of DAG generated in situ or added exogenously, 2c) Determining the mass of putative DAG metabolites, and 2d) direct assessment in vitro of appropriate enzymes. These studies of the nature and subcellular location of DAG metabolism -a process integral to the biochemical mechanisms regulating mediator release - should contribute to a much clearer view of immunologic activation mast cells. This knowledge will help to facilitate the development of new pharmacologic approaches to allergic disorders.