title: Aspirin-triggered 15-epi-lipoxin A4 (ATL) generation by human leukocytes and murine peritonitis exudates: development of a specific 15-epi-LXA4 ELISA.
abstract: Aspirin (ASA) triggers the formation of 15-epi-lipoxins (15-epi-LXs or ATL [ASA-triggered LX]), which are potent bioactive eicosanoids that may contribute to the therapeutic impact of ASA. To elucidate the role of these new compounds in vivo, it is essential to establish quick and sensitive detection methods. To this end, we prepared an enzyme-linked immunosorbent assay specific for 15-epi-LXA4 that proved to be highly sensitive (IC50 approximately 50 pg, minimum detection approximately 3.5 pg) and stereoselective. The amounts of 15-epi-LXA4 generated by human neutrophils from peripheral blood of healthy volunteers using this enzyme-linked immunosorbent assay were in agreement with those values obtained by liquid chromatography. Formation of 15-epi-LXA4 was cell ratio-dependent during THP-1 (a monocytic leukemia cell line)-neutrophil interactions with ASA-treated cells, and 15-epi-LXA4 was not detected with either cell type alone. Generation of 15-epi-LXA4 was also examined in murine peritonitis with ASA administration. Exudates from ASA-treated mice showed increased production of 15-epi-LXA4 that was diminished by indomethacin, a blocker of ASA-dependent acetylation of prostaglandin G/H synthase. A cytochrome P450 inhibitor administered in the presence of ASA did not prevent 15-epi-LXA4 formation, which suggests that P450 does not significantly contribute to formation of 15-epi-LXA4 in this murine model. These results indicate that the new enzyme-linked immunosorbent assay is both sensitive and selective for 15-epi-LXA4 and that 15-epi-LXA4 is produced by human leukocyte-leukocyte interactions. In addition, 15-epi-LXA4 is generated by inflammatory exudates when ASA is administered during murine peritonitis and when prostaglandin G/H synthase is upregulated and acetylated. This assay should provide rapid means to investigate 15-epi-LXA4 generation in both cellular and animal models.
authors.affiliation: Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesia, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: N
authors.initials: N
authors.lastname: Chiang
authors.forename: T
authors.initials: T
authors.lastname: Takano
authors.forename: C B
authors.initials: CB
authors.lastname: Clish
authors.forename: N A
authors.initials: NA
authors.lastname: Petasis
authors.forename: H H
authors.initials: HH
authors.lastname: Tai
authors.forename: C N
authors.initials: CN
authors.lastname: Serhan
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D002460:Cell Line; D002853:Chromatography, Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D005122:Exudates and Transudates / Q000378:metabolism*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis*; D044045:Lipoxins; D013058:Mass Spectrometry; D051379:Mice; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010538:Peritonitis / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: D006893:Hydroxyeicosatetraenoic Acids; D044045:Lipoxins; C040527:lipoxin A4; D001241:Aspirin