Lysophosphatidylcholine and lysophosphatidylinosiol--novel promissing signaling molecules and their possible therapeutic activity.

For many years the role of lysophospholipids (LPLs) was associated only with structural and storage components of the cell without any informational function. Today, based on many research projects performed during the last decades, it is clear that some of the LPLs act as hormone-like signaling molecules and thus are very important inter- and intracellular lipid mediators. They can activate specific membrane receptors and/or nuclear receptors regulating many crucial physiological and pathophysiological processes. The LPLs were iden- tified as involved in a majority of cellular processes, including modulation of disease-related mechanisms observed, for instance, in case of diabetes, obesity, atherosclerosis and cancer. Among LPLs, lysophosphatidylcholine (LPC) and lysophosphatidylinositol (LPI) are becoming attractive research topics. Their recently revealed activities as novel ligands of orphan G protein-coupled receptors (i.e., GPR55 and GPR119) involved in modulation of tumor physiology and insulin secretion seem to be one of the most interesting aspects of these compounds. Moreover, the most recent scientific reports emphasize the significance of the acyl chain structure bound to the glycerol basis of LPL, as it entails different biological properties and activities of the compounds.