Aspirin induces non-enzymatic formation of platelet-activating factor from lyso platelet-activating factor

Opposing effects of platelet-activating factor and lyso-platelet-activating factor on neutrophil and platelet activation.

Platelet-activating factor (PAF) is a potent, bioactive phospholipid that acts on multiple cells and tissues through its G protein-coupled receptor (GPCR). PAF is not stored but is rapidly generated via enzymatic acetylation of the precursor 1-O-hexadecyl-2-hydroxy-sn-glycero-3-phosphocholine (lysoPAF). The bioactivity of PAF is effectively and tightly regulated by PAF acetylhydrolases, which c...

Platelet-Activating Factor Induces Th17 Cell Differentiation

Th17 cells have been implicated in a number of inflammatory and autoimmune diseases. The phospholipid mediator platelet-activating factor (PAF) is found in increased concentrations in inflammatory lesions and has been shown to induce IL-6 production. We investigated whether PAF could affect the development of Th17 cells. Picomolar concentrations of PAF induced IL-23, IL-6, and IL-1β expression ...

Platelet activating factor revisited.

Platelet-activating factor.

Platelet-activating factor is a phospholipid with diverse potent physiological effects. Its actions are achieved at concentrations as low as IO-‘” M in some systems and almost always by lo-’ M as an intercellular messenger. The molecular structure of PAF was discovered through parallel investigations of two different biological activities: a factor in the blood of rabbits undergoing anaphylaxis...

Platelet-activating factor.

Our ability to chemically characterize and synthesize this autacoid of allergy and inflammation has given us a unique opportunity to study these important molecules in a highly disciplined fashion. It has also opened the door to a vista of research approaches to define PAF's normal physiologic role as well as its actions as an immunopathologic mediator. Recent work is described.