Arachidonic acid release and platelet-activating factor formation by staurosporine in human neutrophils challenged with n-formyl peptide.
Staurosporine, a putative protein kinase C (PKC) inhibitor, increased the release of [14C]arachidonic acid dose dependently between 100 nM and 1000 nM in human neutrophils challenged with 100 nM N-formyl-methionine-leucine-phenylalanine (FMLP). Staurosporine also increased the formation of leukotriene B4 (LTB4) and platelet-activating factor (PAF) in a dose-dependent manner. In addition, exogenously added lyso-PAF further augmented [3H]PAF formation in staurosporine-pretreated human neutrophils stimulated by FMLP, thus suggesting an activation of acetyl-CoA: lyso-PAF acetyltransferase by staurosporine. The potentiation of [14C]arachidonic acid release and [3H]PAF formation by staurosporine was further enhanced in the presence of 100 nM phorbol 12-myristate 13-acetate (PMA), which pinpoints a mechanism other than the modulation of PKC in this process, inasmuch as staurosporine antagonizes PMA-induced O2- production and [3H]PAF formation. Additional studies with other putative PKC inhibitors also revealed the potentiating effects of 1-(5-isoquinolinsulfonyl)-2-methylpiperazine (H-7, 20 microM) and sphingosine (2.5 microM) on FMLP-induced [14C]arachidonic acid release and [3H]PAF formation. We therefore conjecture that staurosporine-sensitive protein kinases including PKC are not involved in the activation of phospholipase A2 and acetyl-CoA:lyso-PAF acetyltransferase.
Müller
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Department of Gynecology, Universitätsklinikum Steglitz, Free University Berlin, Germany.
Nigam
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S
D000470:Alkaloids / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000096:biosynthesis; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D010972:Platelet Activating Factor / Q000096:biosynthesis*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D019311:Staurosporine
D000470:Alkaloids; D010972:Platelet Activating Factor; D007975:Leukotriene B4; D016718:Arachidonic Acid; D009240:N-Formylmethionine Leucyl-Phenylalanine; D011493:Protein Kinase C; D010741:Phospholipases A; D054467:Phospholipases A2; D019311:Staurosporine