Diamide primes neutrophils for enhanced release of superoxide anion: relationship to S-thiolation of cellular proteins.
Stimulation of the respiratory burst in phagocytes induces the formation of mixed disulfides between sulfhydryl groups of proteins and low-molecular-weight thiols. We hypothesized that this process (S-thiolation) might be involved in turning off the respiratory burst. However, induction of S-thiolation by pretreatment of neutrophils with diamide, a direct thiol oxidizing agent, actually primed the cells for a two- to fivefold increase in total release and fourfold increase in rate of release of 02- on stimulation by f-Met-Leu-Phe. Generation of intracellular oxidants (hydroethidine fluorescence) was increased ninefold. Priming and S-thiolation were apparent at 1 min of incubation and peaked at 5-10 min. Diamide pretreatment also reduced the lag time between addition of phorbol diester and release of 02- by a mean of 23 s (41%). Dithioerythritol, a sulfhydryl-reducing agent, abolished both the S-thiolation and priming mediated by diamide. H202 also induced priming and S-thiolation; and these were eliminated by dithioerythritol. In contrast to the effect of endotoxin, diamide priming did not affect Ca2+ homeostasis of the neutrophils. Diamide did not significantly alter NADPH oxidase activity in a cell-free system. These findings suggest that sulfhydryl groups on one or more proteins play an important role in modulating the respiratory burst.
Moriguchi
T
T
The Children's Hospital of Philadelphia, Pennsylvania, USA.
Seres
T
T
Ravichandran
V
V
Sasada
M
M
Johnston
R B
RB
D001798:Blood Proteins / Q000378:metabolism*; D002118:Calcium / Q000097:blood / Q000494:pharmacology; D003958:Diamide / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007424:Intracellular Fluid / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000097:blood*; D013481:Superoxides / Q000378:metabolism*
D001798:Blood Proteins; D008070:Lipopolysaccharides; D010972:Platelet Activating Factor; D013438:Sulfhydryl Compounds; D003958:Diamide; D013481:Superoxides; D006861:Hydrogen Peroxide; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D002118:Calcium