Evidence for peroxynitrite as an oxidative stress-inducing compound of aqueous cigarette smoke fractions.
Previous studies have shown that exposure of Swiss 3T3 cells to mainstream cigarette smoke (CS) trapped in phosphate-buffered saline (smoke-bubbled PBS) resulted in the expression of stress response genes, i.e. haem oxygenase and c-fos, partial inhibition of protein phosphatases 1 and 2A, as well as partial depletion of the cellular glutathione (GSH) pool. Using c-fos gene expression in Swiss 3T3 cells as an indicator for a cellular response against oxidative stress, the following observations are consistent with peroxynitrite as an active principal formed by CS in aqueous solutions: (i) sustained c-fos expression was obtained for smoke-bubbled PBS, peroxynitrite itself and a compound known to stoichiometrically release superoxide and nitric oxide (NO) (3-morpholino-sydnonimine, SIN-1); (ii) c-fos expression in cells exposed to aqueous smoke fractions was inhibited by either the superoxide-scavenging enzyme superoxide dismutase (SOD), in combination with catalase, or the NO-scavenger oxyhaemoglobin (HbO2); and (iii) activation of guanylate cyclase in rat lung cells was observed only when bubbling was performed with filtered smoke and with whole smoke in the presence of SOD/catalase. These results are consistent with a rapid NO-consuming reaction coupled with superoxide-generating properties of the particulate phase of CS. Moreover, (iv) the half-life of the c-fos-inducing activity in smoke-bubbled PBS was found to be <1 h which can be explained by a sustained peroxynitrite formation. Finally, depletion of intracellular thiol levels by smoke-bubbled PBS appears to favour the activation of a redox-sensitive component of the c-fos-inducing pathway.
Muller
T
T
INBIFO Institut für biologische Forschung GmBH, Köln, Germany.
Haussmann
H J
HJ
Schepers
G
G
D016475:3T3 Cells; D000818:Animals; D002374:Catalase / Q000494:pharmacology; D004790:Enzyme Induction; D015870:Gene Expression / Q000187:drug effects*; D016762:Genes, fos / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism; D051379:Mice; D008981:Molsidomine / Q000031:analogs & derivatives / Q000633:toxicity; D009566:Nitrates / Q000378:metabolism / Q000633:toxicity*; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D010947:Plants, Toxic; D051381:Rats; D012906:Smoke; D013482:Superoxide Dismutase / Q000378:metabolism / Q000494:pharmacology; D014026:Nicotiana
D009566:Nitrates; D012906:Smoke; C039642:peroxynitric acid; D009569:Nitric Oxide; C002385:linsidomine; D008981:Molsidomine; D002374:Catalase; D013482:Superoxide Dismutase; D006162:Guanylate Cyclase; D005978:Glutathione