The Many Roles of Lysophospholipid Mediators and Japanese Contributions to This Field

Lysophospholipids are phospholipids with only one fatty acid. During the past two decades, it has become apparent that lysophospholipids are not merely degradation products but have various physiological and pathological functions in vivo via G protein-coupled receptor (GPCR)-type receptors. These include lysophosphatidic acid (LPA), sphingosine 1-phosphate (SIP), lysophosphatidylinositol/lysophosphatidylglucose (LPI/LPtdGlc), and lysophosphatidylserine (LysoPS). This review focuses on identifying the functions of the receptors, enzymes, transporters, and carrier proteins required for these four lysophospholipids to function as lipid mediators. We also note that many of advances in this field have been made by Japanese pharmaceutical scientists.