Is the effect of interleukin-1 on glutathione oxidation in cultured human fibroblasts involved in nuclear factor-kappaB activation?
Our understanding of the interleukin-1 (IL-1) signaling molecular mechanisms has recently made considerable progress, with the discovery of the IL-1 receptor-associated kinase and the downstream enzymatic cascade that leads to the activation of nuclear factor-kappaB (NF-kappaB). IL-1 signaling and especially NF-kappaB activation are thought to be redox-sensitive, even though the precise nature and the molecular targets of the oxidants/antioxidants involved remain largely unknown. Here, we investigated the possible role of cellular oxidized/reduced glutathione (GSSG/GSH) balance in IL-1 signaling. We describe a quantitative method based on capillary electrophoresis designed to assay both intracellular GSH and GSSG in adhering fibroblasts. This method allows the GSSG/GSH balance to be followed during IL-1 stimulation. Our data show that IL-1 induces rapid and transient oxidation of intracellular glutathione in human fibroblasts. Using various antioxidants, including pyrrolidine dithiocarbamate and curcumin, we were unable to show a direct relationship between this IL-1-induced glutathione oxidation and NF-kappaB activation. Of the five antioxidants tested, only curcumin was able to inhibit IkappaBalpha degradation upstream and, hence, NF-kappaB DNA-binding activity and NF-kappaB-dependent expression of IL-6 downstream.
Renard
P
P
Laboratoire de Biochimie et de Biologie Cellulaire, Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium. patsy.renard@fundp.ac.be
Delaive
E
E
Van Steenbrugge
M
M
Remacle
J
J
Raes
M
M
D000975:Antioxidants / Q000494:pharmacology; D001665:Binding Sites; D015153:Blotting, Western; D002478:Cells, Cultured; D003474:Curcumin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D020672:I-kappa B Proteins / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013859:Thiocarbamates / Q000494:pharmacology
D000975:Antioxidants; D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D007375:Interleukin-1; D016328:NF-kappa B; D011759:Pyrrolidines; D017382:Reactive Oxygen Species; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D006861:Hydrogen Peroxide; D005978:Glutathione; D003474:Curcumin; D005033:Ethylmaleimide