title: Effects of synthetic sphingosine-1-phosphate analogs on arachidonic acid metabolism and cell death.
abstract: Sphingolipid metabolites such as sphingosine regulate cell functions including cell death and arachidonic acid (AA) metabolism. D-erythro-C18-Sphingosine-1-phosphate (D-e-S1P), a sphingolipid metabolite, acts as an intracellular messenger in addition to being an endogenous ligand of some cell surface receptors. The development of S1P analogs may be useful for studying and/or regulating S1P-mediated cellular responses. In the present study, we found that several synthetic S1P analogs at pharmacological concentrations stimulated AA metabolism and cell death in PC12 cells. D-erythro-N,O,O-Trimethyl-C18-S1P (D-e-TM-S1P), L-threo-O,O-dimethyl-C18-S1P (L-t-DM-S1P) and L-threo-O,O-dimethyl-3O-benzyl-C18-S1P (L-t-DMBn-S1P) at 100 microM stimulated [(3)H]AA release from the prelabeled PC12 cells. L-t-DMBn-S1P at 20 microM increased prostanoid formation in PC12 cells. L-t-DMBn-S1P-induced AA release was inhibited by D-e-sphingosine, but not by the tested PLA(2) inhibitors. L-t-DMBn-S1P did not stimulate the activity of cytosolic phospholipase A(2alpha) (cPLA(2alpha)) in vitro and the translocation of cPLA(2alpha) in the cells, and caused AA release from the cells lacking cPLA(2alpha). These findings suggest that L-t-DMBn-S1P stimulated AA release in a cPLA(2alpha)-independent manner. In contrast, D-e-S1P and D-erythro-N-monomethyl-C18-S1P caused cell death without AA release in PC12 cells, and the effects of D-e-TM-S1P, L-t-DM-S1P and L-t-DMBn-S1P on cell death were limited. Synthetic S1P analogs may be useful tools for studying AA metabolism and cell death in cells.
authors.affiliation: Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Takashiro
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hirabayashi
authors.forename: Syunji
authors.initials: S
authors.lastname: Horie
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Koide
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nishida
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Murayama
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects*; D008246:Lysophospholipids / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D016716:PC12 Cells; D010741:Phospholipases A / Q000378:metabolism; D051381:Rats; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D016718:Arachidonic Acid; D010741:Phospholipases A; D013110:Sphingosine