ENDOTHELIAL ACTIVATION BY AN ISOPROSTANE PHOSPHOLIPID

异前列腺素磷脂对内皮细胞的激活

• 批准号: 6390697
• 负责人: Judith Anne Berliner
• 金额: $ 22.95万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6390697
• 关键词: cell adhesion; epoxides; lipid structure; phospholipids; protein binding; receptor binding; vascular endothelium

The overall goal of this proposal is to synthesize and use for biologic studies a novel bioactive epoxy isoprostane phospholipid that may play an important role the development of atherosclerotic lesions. 1-Palmitoyl-2- (5,6-epoxyisoprostane E2)-sn-glycero-3-phosphocholine (PEIPC), mass 828.5, is present in minimally oxidized LDL (MM-LDL) and increased in atherosclerotic lesions. PEIPC is one of five 828.5 isomers in MM-LDL and in preliminary studies causes a strong activation (compared to the other relatively inactive isomers) of endothelial cell to bind monocytes in vitro. The proposed studies will test the hypothesis that PEIPC activates endothelial cells by interacting with a PAF-like receptor and will characterize binding to this receptor. Most of our preliminary studies of molecules of this mass have been done with mixed isomers. Isomers of 828.5 were shown to highly accumulate in HDL (compared to other bioactive phospholipids) probably because HDL enzymes less easily degrade isomers of 828.5 than other bioactive phospholipids. In preliminary studies we have demonstrated that HDL, shown by others to be less protective against endothelial activation, contained increased levels of 828.5. HDL has been shown to bind at least one of the scavenger receptors. Studies by the Witztum group have shown that l-Palmitoyl-2- (oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), another bioactive phospholipid with antigenic similarity to PEIPC, also binds to macrophage scavenger receptors. We will test the hypothesis that, in endothelial cells, PEIPC binds to the major scavenger receptor LOX-l blocking its normal interaction with HDL. Finally there is evidence that some oxidized phospholipids may bind to proteins and interact with cells in this adducted form. The structure of PEIPC suggests that it may bind to proteins under physiological or pathophysiological conditions. Such adducted phospholipids may be more stable than free bioactive phospholipids. We will test the hypothesis that PEIPC forms adduct with proteins and peptides; and we will perform limited studies using these adducts. Key to carrying out these studies is the availability of a reliable supply of PEIPC and the ability to obtain radiolabeled molecules. This proposal is a combined submission from a chemist with extensive experience in the synthesis of epoxide containing molecules, a cell biologist experienced with testing lipid endothelial interactions and a coinvestigator experienced in both areas. In summary, this interdisciplinary proposal will provide important information about the receptor interactions of the novel epoxy isoprostane phospholipid PEIPC.

该提案的总体目标是将生物活性环氧烷磷脂的新型生物活性环氧树脂磷脂合成并用于生物学研究，该磷脂可能在动脉粥样硬化病变的发展中起重要作用。 1-甲米酰-2-（5,6-氧基异丙烷E2）-SN-甘油-3-磷脂（PEIPC），质量为828.5，在微小氧化的LDL（MM-LDL）中存在，并且在动脉粥样硬化病变中增加。 PEIPC是MM-LDL中的五个828.5异构体之一，在初步研究中，内皮细胞的强大激活（与其他相对不活跃的异构体相比，相比之下）在体外结合单核细胞。拟议的研究将检验以下假设：PEIPC通过与PAF样受体相互作用来激活内皮细胞，并将表征与该受体的结合。我们对该质量分子的大多数初步研究都是用混合异构体进行的。 828.5的异构体显示在HDL中高度积累（与其他生物活性磷脂相比）可能是因为HDL酶比其他生物活性磷脂更容易降解828.5的异构体。在初步研究中，我们证明了其他人证明的HDL对内皮激活的保护不太保护性，其中含有828.5的水平。 HDL已显示结合至少一种清道夫受体。 WITZTUM组的研究表明，L-核酰基-2-（Ooleteroyl）-SN-甘油-3-磷酸胆碱（POVPC），这是另一种与PEIPC抗原相似性的生物活性磷脂，也与巨噬细胞寻求者受体结合。我们将检验以下假设：在内皮细胞中，PEIPC与主要的清道夫受体LOX-L结合，阻断了其正常的与HDL相互作用。最后，有证据表明，某些氧化磷脂可能与蛋白质结合，并以这种加合形式与细胞相互作用。 PEIPC的结构表明，它可能在生理或病理生理条件下与蛋白质结合。这种加合的磷脂可能比游离生物活性磷脂更稳定。我们将测试PEIPC与蛋白质和肽形成加合物的假设。我们将使用这些加合物进行有限的研究。进行这些研究的关键是可靠的PEIPC供应以及获得放射标记分子的能力。该提案是化学家的合并，在合成环氧化物分子的合成方面是一位经验丰富的，这是一名经验丰富的细胞生物学家，该细胞生物学家经历了测试脂质内皮相互作用以及在这两个区域中经历的共同评估剂。总而言之，该跨学科的建议将提供有关新型环氧树脂磷脂PEIPC的受体相互作用的重要信息。