DJ-1 is an indicator for endogenous reactive oxygen species elicited by endotoxin.
We previously found that DJ-1 protein of pI 5.8 (DJ-1/5.8) increased on 2D gels as DJ-1 of pI 6.2 (DJ-1/6.2) decreased, upon exposure of human cells to sublethal levels of oxidative stress, such as H2O2 and paraquat. Here, we show that the DJ-1/5.8 increases concomitantly with endogenous production of reactive oxygen species (ROS) under endotoxin-induced inflammatory conditions. Lipopolysaccharide (LPS) significantly increased the expression of DJ-1/5.8 in murine peritoneal macrophages (Mphi) and a murine macrophage cell line (J774). Diphenylene iodonium, a flavoenzyme inhibitor, blocked the effect of LPS on DJ-1/5.8 expression. Aminoguanidine (AG), a selective inhibitor of type II nitric oxide synthase, had no effect on the DJ-1/5.8 expression, but suppressed accumulation of nitrite in the culture medium after LPS treatment. We also examined the expression of DJ-1/5.8 in lung, since acute lung injury is seen in endotoxin shock. When female mice (6-weeks old) were intraperitoneally given LPS (10 mg/kg), myeloperoxidase (MPO) activity in lung, a marker of neutrophil infiltration, was transiently raised by 3.5 fold. The expression of DJ-1/5.8 in lung was enhanced and then reverted to the control level, in parallel with the MPO activity. These results, taken together, suggest that the DJ-1/5.8 might increase in response to endogenously produced ROS, probably due to activation of NADPH oxidase, and imply that DJ-1 may be useful as an endogenous indicator of oxidative stress status in vivo.
Mitsumoto
A
A
School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Nakagawa
Y
Y
D000818:Animals; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D004731:Endotoxins / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D015513:Oncogene Proteins / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D009195:Peroxidase / Q000378:metabolism; D000071617:Protein Deglycase DJ-1; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012772:Shock, Septic / Q000378:metabolism
D004731:Endotoxins; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D015513:Oncogene Proteins; D017382:Reactive Oxygen Species; D009195:Peroxidase; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1