There is strong evidence for the induction of the inflammatory enzymes 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) in atherosclerosis, asthma, and many types of cancer. Both enzymes mediate the inflammatory response of these diseases through the synthesis of leukotrienes and prostaglandins, respectively. The leukotriene and prostaglandin pathways have traditionally been viewed as independent biosynthetic routes since the committed step toward either pathway is taken as the initial oxygenation of the common substrate, arachidonic acid. This proposal is based on the finding that the 5-LOX product, 5S- hydroxyeicosatetraenoic acid (5S-HETE), is a selective and highly efficient substrate for oxygenation by COX-2 (but not by the COX-1 isozyme). The discovery of this novel substrate for COX-2 intimately links the two eicosanoid pathways. The common 5-LOX/COX-2 product is a novel di-endoperoxide that is structurally reminiscent of, but distinctly different from prostaglandin H2. In the first Specific Aim we propose to analyze the enzymology of the conversion of arachidonic acid into the novel di-endoperoxide by establishing the reaction kinetics, substrate specificity, and the structural basis for binding of 5-HETE in the COX-2 active site. The enzymatic transformation of the di-endoperoxide product will be studied using RAW264.7 cells and murine peritoneal macrophages, prototypical cells that expresses both 5-LOX and COX-2. Endogenous formation of the novel eicosanoid and its family of metabolites will be assessed in mouse atherosclerotic tissue. We will test the hypothesis that the novel di-endoperoxide (or its metabolites) possess anti- inflammatory properties. Preliminary studies have shown that the di-endoperoxide attenuates the release of interleukin-8 from stimulated mast cells and microvascular endothelial cells. The signaling pathways involved in this interaction will be studied using the 5-LOX and COX-2 expressing HMC-1 human mast cell. Characterization of the novel 5-LOX/COX-2 cross-over pathway will undoubtedly lead to an entirely new understanding of the biology of 5-LOX and COX-2, and it will also shed new light on the etiology and regulation of the inflammatory component of diseases like atherosclerosis, asthma, and cancer. These studies could ultimately lead to new therapeutic regimens for the treatment of these diseases using established anti-inflammatory medications.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM076592-04
Application #
7751846
Study Section
Biochemistry and Biophysics of Membranes Study Section (BBM)
Program Officer
Okita, Richard T
Project Start
2007-01-01
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2010-12-31
Support Year
4
Fiscal Year
2010
Total Cost
$288,734
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Pharmacology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Lu, Jianhong; Guo, Shuyuan; Xue, Xinli et al. (2017) Identification of a novel series of anti-inflammatory and anti-oxidative phospholipid oxidation products containing the cyclopentenone moiety in vitro and in vivo: Implication in atherosclerosis. J Biol Chem 292:5378-5391
Teder, Tarvi; Boeglin, William E; Schneider, Claus et al. (2017) A fungal catalase reacts selectively with the 13S fatty acid hydroperoxide products of the adjacent lipoxygenase gene and exhibits 13S-hydroperoxide-dependent peroxidase activity. Biochim Biophys Acta 1862:706-715
Giménez-Bastida, Juan A; Shibata, Takahiro; Uchida, Koji et al. (2017) Roles of 5-lipoxygenase and cyclooxygenase-2 in the biosynthesis of hemiketals E2 and D2 by activated human leukocytes. FASEB J 31:1867-1878
Giménez-Bastida, Juan A; Suzuki, Takashi; Sprinkel, Katie C et al. (2016) Biomimetic synthesis of hemiketal eicosanoids for biological testing. Prostaglandins Other Lipid Mediat :
Schneider, Claus; Gordon, Odaine N; Edwards, Rebecca L et al. (2015) Degradation of Curcumin: From Mechanism to Biological Implications. J Agric Food Chem 63:7606-14
Gordon, Odaine N; Luis, Paula B; Sintim, Herman O et al. (2015) Unraveling curcumin degradation: autoxidation proceeds through spiroepoxide and vinylether intermediates en route to the main bicyclopentadione. J Biol Chem 290:4817-28
Orlando, Benjamin J; McDougle, Daniel R; Lucido, Michael J et al. (2014) Cyclooxygenase-2 catalysis and inhibition in lipid bilayer nanodiscs. Arch Biochem Biophys 546:33-40
Schneider, Claus (2013) Lipidomics: approaches and applications in nutrition research. Mol Nutr Food Res 57:1305
Tejera, Noemi; Boeglin, William E; Suzuki, Takashi et al. (2012) COX-2-dependent and -independent biosynthesis of dihydroxy-arachidonic acids in activated human leukocytes. J Lipid Res 53:87-94
McElroy, Steven J; Hobbs, Stuart; Kallen, Michael et al. (2012) Transactivation of EGFR by LPS induces COX-2 expression in enterocytes. PLoS One 7:e38373

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