Gastrointestinal safety of nitric oxide-derived aspirin is related to inhibition of ICE-like cysteine proteases in rats.
OBJECTIVE
Caspases, a class of cysteine proteases, modulate apoptosis. Nitric oxide (NO)-releasing nonsteroidal anti-inflammatory drugs (NSAIDs) are a new class of NSAID derivatives with reduced gastrointestinal toxicity. The aim of this study was to investigate whether cysteine endoproteases are involved in the pathogenesis of NSAID gastropathy and are target for NO-aspirin (NCX-4016).


METHODS
Rats were treated orally with aspirin or equimolar doses of NCX-4016. Caspase activities were measured by fluorometric assay. Apoptosis was quantified by an enzyme-linked immunosorbent assay for histone-associated DNA, DNA ladder on agarose gel, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay. A primary culture of gastric chief cells was used to investigate whether NCX-4016 modulates guanosine 3',5'-cyclic monophosphate (cGMP)-dependent pathways.


RESULTS
Short- and long-term (7 days) aspirin administration resulted in a time- and dose-dependent gastric injury that was associated with apoptosis and caspase up-regulation. Z-VAD.FMK, a pancaspase inhibitor, and NO donors protected from acute damage induced by aspirin. NCX-4016 spared the gastric mucosa and caused caspase inactivation by S-nitrosylation. Inhibition of tumor necrosis factor (TNF)-alpha release or activity by TAPI-2 or anti-TNF-alpha receptor monoclonal antibodies protected against mucosal damage and caspase activation. NCX-4016 protected gastric chief cells from toxicity induced by TNF-alpha by activating cGMP-dependent pathways.


CONCLUSIONS
Aspirin administration leads to a TNF-alpha-dependent activation of gastric caspases. NO-aspirin spares the gastric mucosa and inhibits caspase activity through cGMP-dependent and -independent pathways.
Fiorucci
S
S
Sezione di Gastroenterologia ed Epatologia, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Perugia, Perugia, Italy. Gastro1@unipg.it
Antonelli
E
E
Santucci
L
L
Morelli
O
O
Miglietti
M
M
Federici
B
B
Mannucci
R
R
Del Soldato
P
P
Morelli
A
A
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D017209:Apoptosis; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000293:injuries; D006801:Humans; D020287:In Situ Nick-End Labeling; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D012459:Salicylates / Q000097:blood; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology; D020298:U937 Cells
D000894:Anti-Inflammatory Agents, Non-Steroidal; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D020030:Nitric Oxide Donors; D012459:Salicylates; D014409:Tumor Necrosis Factor-alpha; D009599:Nitroprusside; D009569:Nitric Oxide; D020169:Caspases; C102148:nitroaspirin; D006152:Cyclic GMP; D001241:Aspirin