Group IID, IIE, IIF and III secreted phospholipase A2s

Abstract Among the 11 members of the secreted phospholipase A 2 (sPLA 2 ) family, group IID, IIE, IIF and III sPLA 2 s (sPLA 2 -IID, -IIE, -IIF and -III, respectively) are “new” isoforms in the history of sPLA 2 research. Relative to the better characterized sPLA 2 s (sPLA 2 -IB, -IIA, -V and -X), the enzymatic properties, distributions, and functions of these “new” sPLA 2 s have remained obscure until recently. Our current studies using knockout and transgenic mice for a nearly full set of sPLA 2 s, in combination with comprehensive lipidomics, have revealed unique and distinct roles of these “new” sPLA 2 s in specific biological events. Thus, sPLA 2 -IID is involved in immune suppression, sPLA 2 -IIE in metabolic regulation and hair follicle homeostasis, sPLA 2 -IIF in epidermal hyperplasia, and sPLA 2 -III in male reproduction, anaphylaxis, colonic diseases, and possibly atherosclerosis. In this article, we overview current understanding of the properties and functions of these sPLA 2 s and their underlying lipid pathways in vivo .