Fluoride activates diradylglycerol and Superoxide generation in human neutrophils via PLD/PA phosphohydrolase‐dependent and ‐independent pathways

[摘要]

In contrast to the rapid, ethanol-inhibited Superoxide generation by the receptor-linked agonist formyl-methionyl-leucyl-phenylalanine (fMLP), fluoride-activated Superoxide generation occurs after a prolonged lag, and as shown herein is relatively ethanol-insensitive. We have investigated fluoride-activation of diradylglycerol generation and phospholipase D activity. Fluoride induces a very large increase in diradylglycerol mass (both 1,2-diacylglycerol (DAG) and 1-O-alkyl,2-acylglycerol (EAG)), with kinetics similar to Superoxide generation. Unlike fMLP-activated diglyceride generation which is completely inhibited by ethanol, that produced by fluoride is only partially (30%) blocked. When the phosphatidylcholine pool is ³H-prelabeled, fluoride activates both [³H]phosphatidic acid (PA) and [³H]diglyceride generation with similar kinetics. Partial inhibition of the production of these species by ethanol was seen, coincident with the appearance of [³H]phosphatidylethanol, indicating phospholipase D-dependent transphosphatidylation had occurred. The data are consistent with the fluoride activation of PA and diglyceride generation by both phospholipase D-dependent and -independent (presumably phospholipase C) mechanisms.

[学科分类] 生物化学/生物物理

[关键词] Superoxide generation;Diacylglycerol;Diradylglycerol;Phospholipase D;Fluoride;Neutrophil;DAG;1;2-diacylglycerol;EAG;1-O-alkyl;2-acylglycerol;PA;phosphatidic acid;fMLP;formyl-methionylleucyl-phenylalanine;PI;phosphatidylinositol;ATP;adenosine 5 '-triphosphate;CB;cytochalasin B;PC;phosphatidylcholine;TLC;thin-layer chromatography;PBS;phosphate-buffered saline;PETH;phosphatidylethanol;EtOH;ethanol;GM-CSF;granulocyte/monocyte colony-stimulating factor;PMA;phorbol 12-myristate 13-acetate