June 9, 1997Open Access
View Full PaperEndogenously produced peroxynitrite induces the oxidation of mitochondrial and nuclear proteins in immunostimulated macrophages
Key Points
- This research aims to understand how endogenously produced peroxynitrite affects protein oxidation in macrophages.
- Macrophages were immunostimulated using bacterial lipopolysaccharide and gamma-interferon.
- Protein oxidation was measured by detecting reactive carbonyls with 2,4-dinitrophenylhydrazine.
- NO synthase inhibitor and superoxide dismutase mimetic were used to assess their effects on protein oxidation.
- Immunostimulation led to significant oxidation of mitochondrial and nuclear proteins.
- Inhibition of NO synthase and use of superoxide dismutase mimetic significantly reduced protein oxidation levels.
- The study confirms that peroxynitrite plays a critical role in protein oxidation during macrophage activation.
Abstract
Here we investigated the role of endogenous nitric oxide (NO) and peroxynitrite in the process of protein oxidation (as measured by the detection of 2,4-dinitrophenylhydrazine-reactive carbonyls) in immunostimulated macrophages. Immunostimulation of the macrophages by bacterial lipopolysaccharide and gamma-interferon (LPS/IFNgamma) resulted in a marked increase in the oxidation of a large number of mitochondrial and nuclear proteins. The inhibitor of NO synthase, N(G)-methyl-L-arginine (3 mM), and the cell-permeable superoxide dismutase mimetic Mn(III)tetrakis(4-benzoic acid)porphyrin (300 microM) both reduced the extent of protein oxidation in response to LPS/IFNgamma. These results support the view that endogenously produced peroxynitrite induces protein oxidation in the mitochondria and nucleus of immunostimulated macrophages.