Phospholipase activation during monocyte adherence and spreading.

摘要: Phospholipase activation is an important element in cellular signal transduction. In our study we investigated the role and regulation of phospholipase during human monocyte adherence spreading. monocytes, inhibition (with bromophenacyl bromide (BPB) or manoalide) impaired cell contrast, neither cyclooxygenase/lipoxygenase nor platelet activating factor receptor blockade affected these responses. The spreading induced by with BPB could be partially reversed addition nM levels arachidonate (20:4(n - 6)). Dihomogammalinolenic acid (20:3(n 6)) substitute for arachidonate, but other polyunsaturated fatty acids were ineffective this regard. inhibitor, was selective its effects on activities. inhibited adherence/spreading-related PMA-stimulated activities, not Ca2+ ionophore-stimulated activity. To further probe spreading, monocytes loaded MAPTAM (bis-(2-amino-5-methylphenoxy)-ethane-N,N,N',N', tetraacetic tetraacetoxymethyl ester), EGTA analog. contrast to inhibition, intracellular chelation did affect inhibit adherence/spreading-stimulated activity, These data suggest that may sequentially activate Ca(2+)-independent then Ca(2+)-dependent phospholipases release arachidonate. appear integral parts adhesion process.