Protective role of nuclear factor kappa B against nitric oxide-induced apoptosis in J774 macrophages.
We investigated the role of constitutive transcription factor nuclear factor kappaB (NF-kappaB) in nitric oxide (NO)-mediated apoptosis in J774 macrophages. Our results show that NF-kappaB is present in untreated J774 cells in a form constitutively active. Incubation of cells with sodium nitroprusside (SNP) and S-nitroso-glutathione (GSNO), two NO-generating compounds, caused: (a) inhibition of constitutive NF-kappaB/DNA binding activity; (b) decrease of cell viability; (c) DNA fragmentation; (d) ApopTag positivity. Pyrrolidine dithiocarbamate (PDTC) and N-alpha-para-tosyl-L-lysine chloromethyl ketone (TLCK), two inhibitors of NF-kappaB activation, showed the same effects of both NO-generating compounds. Furthermore, SNP and GSNO as well as PDTC and TLCK significantly increased the cytoplasmic level of IkappaBalpha. All together these results demonstrate that constitutive NF-kappaB protects J774 macrophages from NO-induced apoptosis. Moreover, these findings show, for the first time, that NO-generating compounds may induce apoptosis in J774 macrophages by down-regulating constitutive NF-kappaB/DNA binding activity and suggest a novel mechanism by which NO induces apoptosis.
D'Acquisto
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F
Department of Experimental Pharmacology, Via Domenico Montesano, 49, University of Naples 'Federico II', Italy.
de Cristofaro
F
F
Maiuri
M C
MC
Tajana
G
G
Carnuccio
R
R
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002460:Cell Line / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology*; D053938:DNA Fragmentation / Q000187:drug effects / Q000502:physiology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000187:drug effects; D020672:I-kappa B Proteins; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology
D000590:Amino Acid Chloromethyl Ketones; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; D000072000:NF-KappaB Inhibitor alpha; D009599:Nitroprusside; D009569:Nitric Oxide