Identification of sn-2 acetyl glycerophosphocholines in human keratinocytes

Evidence is accumulating suggesting that platelet-activating factor plays a role in inflammatory dermatoses. Mass spectrometric methods were used to examine the molecular species of sn-2 acetyl glycerophosphocholines (GPC) synthesized by primary cultures of human neonatal foreskin-derived keratinocytes. Ionophore-stimulated keratinocytes synthesize both 1-alkyl and 1-acyl sn-2 acetyl-GPC, and the relative amounts were as follows: hexadecyl>palmitoyl>octadecyl>stearoyl at the sn-1 position. PAF synthesis in the keratinocyte-derived cell line HaCaT was inhibited by dexamethasone, suggesting that the anti-inflammatory effects of glucocorticosteroids in inflammatory dermatoses might be in part related to the inhibition of the synthesis of mediators such as PAF.