Epoxyisoprostane and epoxycyclopentenone phospholipids regulate monocyte chemotactic protein-1 and interleukin-8 synthesis - Formation of these oxidized phospholipids in response to interleukin-1 beta

Department of Medicine, University of California, Los Angeles, Los Ángeles, California, United States
Journal of Biological Chemistry (Impact Factor: 4.6). 04/2002; 277(9):7271-81. DOI: 10.1074/jbc.M107602200
Source: PubMed

ABSTRACT Monocyte recruitment to the vessel wall, mediated by monocyte chemotactic protein-1 (MCP-1) and interleukin-8 (IL-8), plays an important role in atherogenesis. We have shown previously that minimally oxidized low density lipoprotein, oxidized 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (Ox-PAPC), activates endothelial cells to produce MCP-1 and IL-8. By using liquid chromatography/mass spectrometry methods coupled with bioassay, we report a family of epoxyisoprostane (PEIPC) and epoxycyclopentenone (PECPC) phospholipids that are the components of Ox-PAPC responsible for the majority of this activity. Ox-PAPC contains five chromatographically distinguishable active PEIPC components (m/z 825.5) and four PECPC components (m/z 810.5). All nine components induced endothelial cell synthesis of IL-8 and MCP-1 in a dose-dependent fashion between 0.1 and 5 microm concentrations. The five PEIPC components had identical functional groups and all underwent dehydration to produce m/z 810.5. We present evidence that these phospholipids are regioisomers with epoxide groups at the 5,6-, 8,9-, 11,12-, or 14,15-positions of the sn-2 fatty acid and their epoxide groups is important for biological activity. We have shown previously that peroxisome proliferator-activated receptor alpha is involved in MCP-1 synthesis in response to Ox-PAPC. We now show that PEIPC and PECPC isomers are potent activators of peroxisome proliferator-activated receptor alpha. PEIPC and PECPC isomers are strongly recognized by specific circulating murine natural autoantibodies (EO6) and accumulate in cells treated with IL-1beta. These studies demonstrate that PEIPC and PECPC isomers are potent activators of endothelial cells increasing synthesis of IL-8 and MCP-1. Their accumulation in cells exposed to cytokines and in atherosclerotic lesions suggests that these lipids may play a role in a number of chronic disease processes.

  • [Show abstract] [Hide abstract]
    ABSTRACT: 5,6-Epoxyisoprostane E2 was synthesized via bromohydrination of the cyclopentene and aldol reaction of the α-bromocyclopentanone with the epoxyaldehyde. High regioselectivity in the bromohydrination was attained with recrystallized NBS and pyridine in aqueous DMSO. The enolate for the aldol reaction was generated by adding t-BuLi to the mixture of the α-bromocyclopentanone and ZnI2. This aldol protocol was applied successfully to several cyclopentanones and aldehydes.
    Organic Letters 04/2014; 16(10). DOI:10.1021/ol500654g · 6.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxidized phospholipids (OxPL) were originally discovered as by-products and mediators of chronic inflammation such as in atherosclerosis. Over the last years, an increasing body of evidence led to the notion that OxPL not only contribute to the pathogenesis of chronic inflammatory processes but in addition play an integral role as modulators of inflammation during acute infections. Thereby, host defense mechanisms involve the generation of oxygen radicals that oxidize ubiquitously present phospholipids, which in turn act as danger-associated molecular patterns (DAMPs). These OxPL-derived DAMPs can exhibit both pro- and anti-inflammatory functions that ultimately alter the host response to pathogens. In this review, we summarize the currently available data on the role of OxPL in infectious diseases.
    Cellular and Molecular Life Sciences CMLS 11/2014; DOI:10.1007/s00018-014-1780-3 · 5.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peroxidation of membranes and lipoproteins converts "inert" phospholipids into a plethora of oxidatively modified phospholipids (oxPL) that can act as signaling molecules. In this review, we will discuss four major classes of oxPL: mildly oxygenated phospholipids, phospholipids with oxidatively truncated acyl chains, phospholipids with cyclized acyl chains, and phospholipids that have been oxidatively N-modified on their headgroups by reactive lipid species. For each class of oxPL we will review the chemical mechanisms of their formation, the evidence for their formation in biological samples, the biological activities and signaling pathways associated with them, and the catabolic pathways for their elimination. We will end by briefly highlighting some of the critical questions that remain about the role of oxPL in physiology and disease.
    Chemistry and Physics of Lipids 04/2014; 181. DOI:10.1016/j.chemphyslip.2014.03.002 · 2.59 Impact Factor