PLATELET-ACTIVATING-FACTOR PRODUCTION BY HUMAN FETAL MICROGLIA - EFFECT OF LIPOPOLYSACCHARIDES AND TUMOR-NECROSIS-FACTOR-ALPHA

Since platelet-activating factor (PAF) exerts neurotoxic effects on br ain cells, we explored the possibility of PAF production by human feta l microglial cells in vitro. PAF content in pure cultures was assayed and characterized in basic conditions, and after stimulation with grow th factors and cytokines. Results showed that microglia cells synthesi zed PAF when challenged with tumor necrosis factor-alpha and lipopolys accharides, whereas other molecules, such as gamma-interferon or basic fibroblast growth factor, were ineffective. The induced PAF productio n was concentration- and time-dependent. These results are in line wit h the hypothesis that microglia can start a cascade of events leading to tissue damage, thus playing a central role in the pathogenesis of s everal central nervous system diseases.