title: Possible involvement of aiPLA2 in the phosphatidylserine-containing liposomes induced production of PGE2 and PGD2 in microglia.
abstract: Liposomes containing phosphatidylserine (PSL) produce PGE2 after being phagocytosed by microglia, but the precise underlying mechanism behind it still remains unclear. Here, we showed that liposomes consisting of phosphatidylserine and lysophosphatidylcholine, a lipolysis product of phosphatidylcholine by PLA2, were phagocytosed by microglia, but failed to induce secretion of PGE2. Furthermore, PSL-induced PGE2 secretion was significantly inhibited by MJ33, an aiPLA2 inhibitor, but not by AACOCF3, a cPLA2 inhibitor. PSL also produced PGD2 and 15d-PGJ2 in microglia. We thus hypothesize that free arachidonic acid is supplied through aiPLA2-mediated lipolysis of phagocytosed phosphatidylcholine, leading to the production of PGH2 and its downstream metabolites.
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Takayama
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wu
authors.forename: Hong Mei
authors.initials: HM
authors.lastname: Ma
authors.forename: Ryo
authors.initials: R
authors.lastname: Okada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D015232:Dinoprostone / Q000096:biosynthesis*; D008081:Liposomes; D017628:Microglia / Q000187:drug effects / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology; D010718:Phosphatidylserines / Q000737:chemistry / Q000502:physiology*; D064801:Phospholipase A2 Inhibitors; D015230:Prostaglandin D2 / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001095:Arachidonic Acids; D008081:Liposomes; D010718:Phosphatidylserines; D064801:Phospholipase A2 Inhibitors; C081565:arachidonyltrifluoromethane; D015232:Dinoprostone; D015230:Prostaglandin D2
keywords: 15d-PGJ(2); Microglia; PGD(2); PGE(2); Phosphatidylserine liposomes; aiPLA(2)