Presentation of Nitric Oxide Regulates Monocyte Survival through Effects on Caspase-9 and Caspase-3 Activation

• Published in: The Journal of biological chemistry Vol. 278; no. 15; pp. 12894 - 12902
• Main Authors: Zeigler, Mandy M, Doseff, Andrea I, Galloway, Michelle F, Opalek, Judy M, Nowicki, Philip T, Zweier, Jay L, Sen, Chandan K, Marsh, Clay B
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 11-04-2003
• Subjects: Caspase 3; Caspase 9; Caspases - blood; Cell Survival - drug effects; DNA Fragmentation - drug effects; Enzyme Activation; Glutathione - blood; Humans; Hydrazines - pharmacology; In Vitro Techniques; Kinetics; Monocytes - cytology; Monocytes - drug effects; Monocytes - enzymology; Nitric Oxide - pharmacology; Nitric Oxide Donors - pharmacology; Nitrogen Oxides; S-Nitrosoglutathione
• DOI: 10.1074/jbc.M213125200
• EISSN: 1083-351X
• ISSN: 0021-9258

In the absence of survival factors, blood monocytes undergo spontaneous apoptosis, which involves the activation of caspase-3.
Although nitric oxide can block caspase-3 activation and promote cell survival, it can also induce apoptosis. We hypothesized
that nitrosothiols that promote protein S -nitrosylation would reduce caspase-3 activation and cell survival, whereas nitric oxide donors (such as 1-propamine 3-(2-hydroxy-2-nitroso-1-propylhydrazine
(PAPA) NONOate and diethylamine (DEA) NONOate) that do not target thiol residues would not. Using human monocytes as a model,
we observed that nitrosothiol donors S -nitrosoglutathione and S -nitroso- N -acetylpenicillamine suppressed caspase-9 and caspase-3 activity and DNA fragmentation. In contrast, PAPA or DEA NONOate did
not promote monocyte survival events and appeared to inhibit monocyte survival induced by macrophage colony-stimulating factor.
The caspase-3-selective inhibitor DEVD-fluoromethyl ketone reversed DNA fragmentation events, and the caspase-9 inhibitor
LEHD-fluoromethyl ketone reversed caspase-3 activity in monocytes treated with PAPA or DEA NONOate in the presence of macrophage
colony-stimulating factor. These results were not caused by differences in glutathione levels or the kinetics of nitric oxide
release. Moreover, S -nitrosoglutathione and S -nitroso- N -acetylpenicillamine directly blocked the activity of recombinant caspase-3, which was reversed by the reducing agent dithiothreitol,
whereas PAPA or DEA NONOate did not block the enzymatic activity of caspase-3. These data support the hypothesis that nitrosylation
of protein thiol residues by nitric oxide is critical for promoting the survival of human monocytes.