Platelet-activating factor (PAF) is a pro-inflammatory phospholipid mediator that is rapidly synthesized by lyso-PAF acetyltransferase (lyso-PAFAT) in response to extracellular stimuli. Two types of lyso-PAFAT have been identified: lysophosphatidylcholine acyltransferase (LPCAT)1, which is mostly expressed in the lungs, and LPCAT2, which is expressed in inflammatory cells. TSI-01 is a selective inhibitor of LPCAT2 (IC50s = 0.47 versus 3.02 μM for human LPCAT2 and LPCAT1, respectively). At 60 μM it was shown to suppress PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore.
