1-Palmitoyl-2-(5,6-epoxyisoprostanoyl E )-sn-glycero-3-phosphatidylcholine (PEIPC) is emerging as a major regulator of vascular cell function. In endothelial cells it has been demonstrated to increase inflammation, procoagulant responses, to regulate junction permeability and to increase oxidative stress. In macrophages it has been demonstrated to regulate dendritic cell differentiation. The goal of the proposed studies is to synthesize sufficient quantities of the most active diastereomer in order to gain insight into the mechanism of action of PEIPC. In previous studies we synthesized one isomer of PEIPC consistent with the NMR of the natural PEIPC.
In Aim 1 we will now synthesize the diasteromer and identify the most active of the two isomers in regulating endothelial cell responses. We have observed that PEIPC can covalently bind to at least 20 endothelial cell proteins.
In Aim 2 we will identify the PEIPC functionality (likely the enone or the epoxide) that interacts with proteins. We will begin by examining the interaction with functional groups of amino acids, then examine the interaction of the most active functional group of PEIPC with peptides. Using two model proteins that bind PEIPC, VEGFR2 and H-ras, we will determine the amino acid sequence involved in binding of PEIPC or its free fatty acid. Using electrospray ionization-tandem mass spectrometry, unique fragmentation spectra produced by these specific lipid-protein interactions will be identified for use in discovering additional endothelial cell protein targets of PEIPC. Armed with this knowledge of the mechanism of the covalent binding of PEIPC to model proteins, we will synthesize analogues of PEIPC and test their effects on PEIPC action. We have previously determined that activation of VEGFR2 is required for the OxPAPC and PEIPC mediated activation of ERK and SREBP. We have also determined that inactivation of H-Ras is necessary for the activation of beta one integrins that lead to monocyte binding. Effects of antagonists on these responses will be determined. Overall these studies will define the chemistry of the PEIPC interaction with selected proteins that control endothelial cell function and will test the hypothesis that covalent binding of PEIPC activates pathways that control the endothelial cell inflammatory response.
Oxidized phospholipids, which accumulate in atherosclerotic lesions and other chronic inflammatory sites, have been shown to be important regulators of endothelial cell inflammatory and pro-coagulant responses that contribute to atherosclerosis. These studies will gain insight into how a particular oxidized phospholipid, PEIPC, causes this activation and will develop analogues to inhibit activation. These studies thus may provide a new drug target for atherosclerosis and other chronic inflammatory diseases.
|Kim, Seonwook; Yang, Lihua; Kim, Seongu et al. (2017) Targeting hepatic heparin-binding EGF-like growth factor (HB-EGF) induces anti-hyperlipidemia leading to reduction of angiotensin II-induced aneurysm development. PLoS One 12:e0182566|
|Emert, Benjamin; Hasin-Brumshtein, Yehudit; Springstead, James R et al. (2014) HDL inhibits the effects of oxidized phospholipids on endothelial cell gene expression via multiple mechanisms. J Lipid Res 55:1678-92|
|Yan, Xinmin; Lee, Sangderk; Gugiu, B Gabriel et al. (2014) Fatty acid epoxyisoprostane E2 stimulates an oxidative stress response in endothelial cells. Biochem Biophys Res Commun 444:69-74|
|Birukova, Anna A; Starosta, Vitaliy; Tian, Xinyong et al. (2013) Fragmented oxidation products define barrier disruptive endothelial cell response to OxPAPC. Transl Res 161:495-504|
|Erbilgin, Ayca; Siemers, Nathan; Kayne, Paul et al. (2013) Gene expression analyses of mouse aortic endothelium in response to atherogenic stimuli. Arterioscler Thromb Vasc Biol 33:2509-17|
|Zhong, Wei; Springstead, James R; Al-Mubarak, Ramea et al. (2013) An epoxyisoprostane is a major regulator of endothelial cell function. J Med Chem 56:8521-32|
|Springstead, James R; Gugiu, B Gabriel; Lee, Sangderk et al. (2012) Evidence for the importance of OxPAPC interaction with cysteines in regulating endothelial cell function. J Lipid Res 53:1304-15|
|Lee, Sangderk; Birukov, Konstantin G; Romanoski, Casey E et al. (2012) Role of phospholipid oxidation products in atherosclerosis. Circ Res 111:778-99|
|Romanoski, Casey E; Che, Nam; Yin, Fen et al. (2011) Network for activation of human endothelial cells by oxidized phospholipids: a critical role of heme oxygenase 1. Circ Res 109:e27-41|
|Berliner, Judith A; Leitinger, Norbert; Tsimikas, Sotirios (2009) The role of oxidized phospholipids in atherosclerosis. J Lipid Res 50 Suppl:S207-12|
Showing the most recent 10 out of 30 publications