Protein kinase C-dependent and -independent activation of the NADPH oxidase of human neutrophils.
The protein kinase C inhibitor, staurosporine, inhibited NADPH oxidase activity of human neutrophils activated by phorbol myristate acetate. However, this inhibitor had no effect on either the initiation or the maximal rate of O2- secretion activated by the chemotactic peptide, fMet-Leu-Phe, but resulted in a more rapid termination of oxidant production. Similarly, staurosporine had no effect on the rapid (1 min) increase in luminol-dependent chemiluminescence activated by fMet-Leu-Phe, but the second (intracellular) phase of oxidant production was inhibited. The initial burst of oxidant production during phagocytosis was similarly protein kinase C-independent, but again the later phases of oxidase activity were staurosporine-sensitive. Neutrophils loaded with Quin-2 at concentrations sufficient to act as a Ca2+ buffer could not secrete O2- in response to fMet-Leu-Phe; although the initial (protein kinase C-independent) burst of luminol chemiluminescence was not observed in fMet-Leu-Phe-stimulated Ca2(+)-buffered cells, the second phase of (protein kinase C-dependent) oxidant production was largely unaffected. Hence, the initial burst of oxidant production activated by fMet-Leu-Phe, opsonized zymosan, and latex beads is independent of the activity of protein kinase C-dependent intracellular activation processes, but the activity of this kinase is required to extend or sustain the duration of oxidant production.
Watson
F
F
Department of Biochemistry, University of Liverpool, United Kingdom.
Robinson
J
J
Edwards
S W
SW
D000470:Alkaloids / Q000494:pharmacology; D000634:Aminoquinolines; D004789:Enzyme Activation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D008163:Luminescent Measurements; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D011493:Protein Kinase C / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D019311:Staurosporine; D013481:Superoxides; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000470:Alkaloids; D000634:Aminoquinolines; D011994:Recombinant Proteins; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate; C035739:Quin2