title: Secreted phospholipase A2 and mast cells.
abstract: Phospholipase A2s (PLA2s) are a group of enzymes that hydrolyze the sn-2 position of phospholipids to release (typically unsaturated) fatty acids and lysophospholipids, which serve as precursors for a variety of bioactive lipid mediators. Among the PLA2 superfamily, secreted PLA2 (sPLA2) enzymes comprise the largest subfamily that includes 11 isoforms with a conserved His-Asp catalytic dyad. Individual sPLA2 enzymes exhibit unique tissue and cellular localizations and specific enzymatic properties, suggesting their distinct biological roles. Recent studies using transgenic and knockout mice for individual sPLA2 isofoms have revealed their involvement in various pathophysiological events. Here, we overview the current state of knowledge about sPLA2s, specifically their roles in mast cells (MCs) in the context of allergology. In particular, we highlight group III sPLA2 (PLA2G3) as an "anaphylactic sPLA2" that promotes MC maturation and thereby anaphylaxis through a previously unrecognized lipid-orchestrated circuit.
authors.affiliation: Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; CREST, Japan Science and Technology Agency, Saitama, Japan. Electronic address: murakami-mk@igakuken.or.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Taketomi
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015777:Eicosanoids / Q000096:biosynthesis; D054520:Group III Phospholipases A2 / Q000378:metabolism; D006801:Humans; D008407:Mast Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D054510:Phospholipases A2, Cytosolic / Q000378:metabolism; D054497:Phospholipases A2, Secretory / Q000378:metabolism*
chemical_list: D015777:Eicosanoids; D054520:Group III Phospholipases A2; D054510:Phospholipases A2, Cytosolic; D054497:Phospholipases A2, Secretory
keywords: Anaphylaxis; Animal model; Lipid mediators; Mast cells; Phospholipase A(2)