Regulation of 5-lipoxygenase activity by the glutathione status in human polymorphonuclear leukocytes.
The influence of the glutathione status of human polymorphonuclear leukocytes (PMN) on 5-lipoxygenase activity was studied by treating cells with increasing concentrations of 1-chloro-2,4-dinitrobenzene (Dnp-Cl) or azodicarboxylic acid bis(dimethylamide) (Diamide). Subsequent incubation with arachidonate resulted in an up to tenfold-stimulated formation of 5-hydroxyeicosatetraenoic acid, leukotriene B4, leukotriene B4 isomers and omega-hydroxyleukotriene B4. Higher concentrations of the GSH reagents were inhibitory. At maximal stimulation by Dnp-Cl, 5-hydroperoxyeicosatetraenoic acid started to be built up at the expense of 5-HETE at glutathione levels which were diminished by about 50% compared to resting cells. No increase in cytosolic Ca2+ could be measured under these conditions by the fura-2 method. In PMN homogenates Dnp-Cl and Diamide were without effect and even caused inhibition when 5-lipoxygenase was stimulated by Ca2+ and ATP. 15-Lipoxygenase was either unchanged in the case of Diamide, or even increased after pretreatment with Dnp-Cl. The results allow us to conclude that 5-lipoxygenase activity in intact PMN is regulated not only by Ca2+ but in a complex manner also by the glutathione redox status. Conditions of oxidative stress increase the activity which may reflect the in vivo situation under phagocytosis and oxidative burst.
Hatzelmann
A
A
Faculty of Biology, University of Konstanz, Federal Republic of Germany.
Ullrich
V
V
D000328:Adult; D001094:Arachidonate 5-Lipoxygenase / Q000097:blood*; D001091:Arachidonate Lipoxygenases / Q000097:blood*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003958:Diamide / Q000494:pharmacology; D004137:Dinitrochlorobenzene / Q000494:pharmacology; D005978:Glutathione / Q000097:blood*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000097:blood; D007700:Kinetics; D007975:Leukotriene B4 / Q000097:blood; D015289:Leukotrienes; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*
D001095:Arachidonic Acids; D004137:Dinitrochlorobenzene; D006893:Hydroxyeicosatetraenoic Acids; D015289:Leukotrienes; D003958:Diamide; D007975:Leukotriene B4; D016718:Arachidonic Acid; D000001:Calcimycin; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; D009240:N-Formylmethionine Leucyl-Phenylalanine; C025348:arachidonic acid 5-hydroperoxide; D001091:Arachidonate Lipoxygenases; D001094:Arachidonate 5-Lipoxygenase; D005978:Glutathione; D002118:Calcium