Regulation by mitochondrial superoxide and NADPH oxidase of cellular formation of nitrated cyclic GMP: potential implications for ROS signalling.

Abstract

8-Nitro-cGMP (8-nitroguanosine 3',5'-cyclic monophosphate) is a nitrated derivative of cGMP, which can function as a unique electrophilic second messenger involved in regulation of an antioxidant adaptive response in cells. In the present study, we investigated chemical and biochemical regulatory mechanisms involved in 8-nitro-cGMP formation, with particular focus on the roles of ROS (reactive oxygen species). Chemical analyses demonstrated that peroxynitrite-dependent oxidation and myeloperoxidase-dependent oxidation of nitrite in the presence of H2O2 were two major pathways for guanine nucleotide nitration. Among the guanine nucleotides examined, GTP was the most sensitive to peroxynitrite-mediated nitration. Immunocytochemical and tandem mass spectrometric analyses revealed that formation of 8-nitro-cGMP in rat C6 glioma cells stimulated with lipopolysaccharide plus pro-inflammatory cytokines depended on production of both superoxide and H2O2. Using the mitochondria-targeted chemical probe MitoSOX Red, we found that mitochondria-derived superoxide can act as a direct determinant of 8-nitro-cGMP formation. Furthermore, we demonstrated that Nox2 (NADPH oxidase 2)-generated H2O2 regulated mitochondria-derived superoxide production, which suggests the importance of cross-talk between Nox2-dependent H2O2 production and mitochondrial superoxide production. The results of the present study suggest that 8-nitro-cGMP can serve as a unique second messenger that may be implicated in regulating ROS signalling in the presence of NO.

• Authors: Khandaker Ahtesham Ahmed, Tomohiro Sawa, Hideshi Ihara, Shingo Kasamatsu, Jun Yoshitake, Md Mizanur Rahaman, Tatsuya Okamoto, Shigemoto Fujii, Takaaki Akaike
• Journal: The Biochemical journal (Biochem J) Vol. 441 Issue 2 Pg. 719-30 (Jan 15 2012) ISSN: 1470-8728 [Electronic] England
• PMID: 21967515 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 8-nitroguanosine 3',5'-cyclic monophosphate
• Lipopolysaccharides
• Nitrogen Oxides
• Reactive Nitrogen Species
• Reactive Oxygen Species
• Rotenone
• Superoxides
• Peroxynitrous Acid
• 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt
• Hydrogen Peroxide
• NADPH Oxidases
• Cyclic GMP

Topics

• 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt (pharmacology)
• Animals
• Cell Line, Tumor
• Cyclic GMP (analogs & derivatives, pharmacology)
• Hydrogen Peroxide (metabolism)
• Lipopolysaccharides (pharmacology)
• Mitochondria (drug effects, metabolism)
• NADPH Oxidases (metabolism)
• Nitrogen Oxides (metabolism)
• Peroxynitrous Acid (metabolism)
• Rats
• Reactive Nitrogen Species (metabolism)
• Reactive Oxygen Species (metabolism)
• Rotenone (pharmacology)
• Signal Transduction (physiology)
• Superoxides (metabolism)