NCX-4016, a nitric oxide-releasing aspirin, protects endothelial cells against apoptosis by modulating mitochondrial function.
We investigated the effect of a nitric oxide (NO)-releasing derivative of aspirin (NCX-4016) on a mitochondria-dependent model of apoptosis in human umbilical endothelial cells (HUVEC). Exposure of HUVEC to staurosporine caused a progressive fall in mitochondrial membrane potential (DeltaPsi(m)) and apoptosis. Exposure to an NO donor, (z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO), caused an early (1-3h) hyperpolarization of DeltaPsi(m) and reduction of apoptosis that was followed (at 4-8 h) by an accelerated collapse of DeltaPsi(m) and cell death. In contrast, treatment with NCX-4016, but not with aspirin or a non-NO-releasing analogue of NCX-4016, protected HUVEC against the apoptotic actions of staurosporine for up to 8 h. Confocal microscopy demonstrated that although NCX-4016 released NO in subcellular compartments, DETA-NO caused a generalized increase in cytosolic fluorescence. Exposure to DETA-NO resulted in a rapid and profound inhibition of cell respiration (78.3 +/- 6.4%), whereas NCX-4016 caused a less pronounced reduction in oxygen consumption (43.5 +/- 5.3%). Staurosporine caused a time-dependent activation of proapoptotic caspases. NCX-4016 prevented this activation, whereas DETA-NO failed to inhibit caspase activity. In contrast to DETA-NO, NCX-4016 did not increase mitochondrial oxidative stress. These data demonstrated that NCX-4016 conveys NO directly inside endothelial cells and modulates mitochondrial function.
Dipartimento di Medicina Clinica e Sperimentale, Clinica di Gastroenterologia ed Epatologia, Università degli Studi di Perugia, 06122 Perugia, Italy. fiorucci@unipg.it
Stefano
S
Fiorucci
Andrea
A
Mencarelli
Roberta
R
Mannucci
Eleonora
E
Distrutti
Antonio
A
Morelli
Piero
P
del Soldato
Salvador
S
Moncada
D017209:Apoptosis / Q000187:drug effects*; D001241:Aspirin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D019311:Staurosporine / Q000494:pharmacology; D013997:Time Factors
D009569:Nitric Oxide; C102148:nitroaspirin; D019311:Staurosporine; D001241:Aspirin