NCX 4040, a nitric oxide-donating aspirin, exerts anti-inflammatory effects through inhibition of I kappa B-alpha degradation in human monocytes.
NO-donating aspirins consist of aspirin to which a NO-donating group is covalently linked via a spacer molecule. NCX 4040 and NCX 4016 are positional isomers with respect to the -CH(2)ONO(2) group (para and meta, respectively) on the benzene ring of the spacer. Because positional isomerism is critical for antitumor properties of NO-donating aspirins, we aimed to compare their anti-inflammatory effects with those of aspirin in vitro. Thus, we assessed their impacts on cyclooxygenase-2 activity (by measuring PGE(2) levels), protein expression, and cytokine generation(IL-1beta, IL-18, TNF-alpha, and IL-10) in human whole blood and isolated human monocytes stimulated with LPS. Interestingly, we found that micromolar concentrations of NCX 4040, but not NCX 4016 or aspirin, affected cyclooxygenase-2 expression and cytokine generation. We compared the effects of NCX 4040 with those of NCX 4016 or aspirin on IkappaB-alpha stabilization and proteasome activity in the LPS-stimulated human monocytic cell line THP1. Differently from aspirin and NCX 4016, NCX 4040, at a micromolar concentration range, inhibited IkappaB-alpha degradation. In fact, NCX 4040 caused concentration-dependent accumulation of IkappaB-alpha and its phosphorylated form. This effect was not reversed by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of guanylyl cyclase, thus excluding the contribution of NO-dependent cGMP generation. In contrast, IkappaB-alpha accumulation by NCX 4040 may involve an inhibitory effect on proteasome functions. Indeed, NCX 4040 inhibited 20S proteasome activity when incubated with intact cells but not in the presence of cell lysate supernatants, thus suggesting an indirect inhibitory effect. In conclusion, NCX 4040 is an inhibitor of IkappaB-alpha degradation and proteasome function, and it should be taken into consideration for the development of novel anti-inflammatory and chemopreventive agents.
Ricciotti
Emanuela
E
Department of Medicine and Center of Excellence on Aging, School of Medicine, G. d'Annunzio University, Chieti, Italy.
Dovizio
Melania
M
Di Francesco
Luigia
L
Anzellotti
Paola
P
Salvatore
Tania
T
Di Francesco
Andrea
A
Sciulli
Maria G
MG
Pistritto
Giuseppa
G
Monopoli
Angela
A
Patrignani
Paola
P
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology*; D001241:Aspirin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology; D045744:Cell Line, Tumor; D051545:Cyclooxygenase 1 / Q000097:blood; D051546:Cyclooxygenase 2 / Q000097:blood; D015232:Dinoprostone / Q000096:biosynthesis / Q000097:blood; D006801:Humans; D020672:I-kappa B Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000502:physiology; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D020030:Nitric Oxide Donors / Q000737:chemistry / Q000494:pharmacology*; D009574:Nitro Compounds / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; C498045:NCX 4040; C000606204:NFKBIA protein, human; D020030:Nitric Oxide Donors; D009574:Nitro Compounds; D000072000:NF-KappaB Inhibitor alpha; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D015232:Dinoprostone; D001241:Aspirin