Bioactive lipid mediators and reactive oxygen species

生物活性脂质信使的细胞生化过程的产生往往是在相当大的生化调节。然而，生物活性脂质也通过活性氧物质与细胞膜中存在的脂质前体的相互作用以不受调节的模式产生。这些脂质介质的结构分析和定量需要开发复杂而非特异性的分析技术，这些技术能够提供脂质的特定数据，而它们存在于密切相关的化合物的复杂混合物中。质谱就是这样一种工具。这项资助的一个主要目标是进一步开发复杂的质谱法，包括电喷雾电离和MALDI电离技术，适用于对暴露于活性氧后细胞膜中的脂质介质进行定性和定量分析。的 还将研究质谱法作为用于成像组织中脂质的工具的潜力，目的是应用质谱成像来确定小鼠暴露于环境相关浓度的臭氧后氧固醇在肺气道中的精确定位。一个重要的具体目标是了解臭氧在肺中毒性的分子基础。将进一步研究臭氧对胆固醇的氧化作用和活性氧甾醇的形成。臭氧与缩醛磷脂的反应也将在研究中进行调查，以检验以下假设： 乙烯基醚磷脂在保护细胞免受臭氧与其它内源性脂质反应后的潜在毒性反应中起重要作用。磷脂酰丝氨酸和甘油磷酸乙醇胺脂质在细胞凋亡过程中的氧化也将进行研究。具体的目标将是确定和结构表征氧化磷脂酰丝氨酸和探测这些氧化脂质的形成机制和潜在的生物学功能，包括它们在细胞凋亡中发挥的作用。的 本计划项目补助金的这一部分的研究在广义上补充了其他项目对脂质介质产生、调节和作用机制的理解。

The generation of biologically active lipid messengers by cellular biochemical processes is often under considerable biochemical regulation. However, biologically active lipids are also generated, in an unregulated mode, by the interaction of reactive oxygen species with lipid precursors present in the membranes of cells. The structural analysis and quantitation of these lipid mediators requires the development of sophisticated yet nonspecific analytical techniques that are capable of providing specific data for lipids while they are present in complex mixtures of closely related compounds. Mass spectrometry is such a tool. A major objective of this grant is to further develop sophisticated mass spectrometry including electrospray ionization and MALDI ionization techniques suitable for the qualitative and quantitative analysis of lipid mediators derived from cellular membranes following exposure to reactive oxygen species. The potential for mass spectrometry as a tool used for imaging lipids in tissues will also be investigated with the intent to apply mass spectrometric imaging to determine the precise localization of oxysterols in pulmonary airways following exposure of mice to environmentally relevant concentrations of ozone. One important specific goal is to understand the molecular basis underlying the toxicity of ozone in the lung. The oxidation of cholesterol by ozone and the formation of active oxysterols will be further examined. The reaction of ozone with plasmalogen glycerophospholipids will also be investigated in studies to test the hypothesis that vinyl ether phospholipids serve an important role in protecting cells from potentially toxic reactions of ozone following reactions with other endogenous lipids. The oxidation of phosphatidylserine and glycerophosphoethanolamine lipids during the process of cellular apoptosis will also be investigated. The specific goal will be to identify and structurally characterize oxidized phosphatidylserine and probe the mechanism of formation and potential biological functions of these oxidized lipids including the role they play in apoptosis. The studies in this portion of the program project grant complements the other projects in the broad sense of understanding mechanisms of lipid mediator production, regulation, and action.