title: Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production.
abstract: Previously we identified palmitoyl-lysophosphatidylcholine (16:0 LPC), linoleoyl-LPC (18:2 LPC), arachidonoyl-LPC (20:4 LPC), and oleoyl-LPC (18:1 LPC) as the most prominent LPC species generated by the action of endothelial lipase (EL) on high-density lipoprotein. In the present study, the impact of those LPC on prostacyclin (PGI(2)) production was examined in vitro in primary human aortic endothelial cells (HAEC) and in vivo in mice. Although 18:2 LPC was inactive, 16:0, 18:1, and 20:4 LPC induced PGI(2) production in HAEC by 1.4-, 3-, and 8.3-fold, respectively. LPC-elicited 6-keto PGF1α formation depended on both cyclooxygenase (COX)-1 and COX-2 and on the activity of cytosolic phospholipase type IVA (cPLA2). The LPC-induced, cPLA2-dependent (14)C-arachidonic acid (AA) release was increased 4.5-fold with 16:0, 2-fold with 18:1, and 2.7-fold with 20:4 LPC, respectively, and related to the ability of LPC to increase cytosolic Ca(2+) concentration. In vivo, LPC increased 6-keto PGF(1α) concentration in mouse plasma with a similar order of potency as found in HAEC. Our results indicate that the tested LPC species are capable of eliciting production of PGI(2), whereby the efficacy and the relative contribution of underlying mechanisms are strongly related to acyl-chain length and degree of saturation.
authors.affiliation: Institute of Molecular Biology and Biochemistry, University of Helsinki, Helsinki, Finland.
authors.forename: Monika
authors.initials: M
authors.lastname: Riederer
authors.forename: Pauli J
authors.initials: PJ
authors.lastname: Ojala
authors.forename: Andelko
authors.initials: A
authors.lastname: Hrzenjak
authors.forename: Wolfgang F
authors.initials: WF
authors.lastname: Graier
authors.forename: Roland
authors.initials: R
authors.lastname: Malli
authors.forename: Michaela
authors.initials: M
authors.lastname: Tritscher
authors.forename: Martin
authors.initials: M
authors.lastname: Hermansson
authors.forename: Bernhard
authors.initials: B
authors.lastname: Watzer
authors.forename: Horst
authors.initials: H
authors.lastname: Schweer
authors.forename: Gernot
authors.initials: G
authors.lastname: Desoye
authors.forename: Akos
authors.initials: A
authors.lastname: Heinemann
authors.forename: Sasa
authors.initials: S
authors.lastname: Frank
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D011464:Epoprostenol / Q000096:biosynthesis*; D006801:Humans; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D008244:Lysophosphatidylcholines; D012333:RNA, Messenger; D011464:Epoprostenol; D051546:Cyclooxygenase 2