A Novel Mechanism Underlying the Susceptibility of Neuronal Cells to Nitric Oxide: the Occurrence and Regulation of Protein S-nitrosylation is the Checkpoint.
From: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Journal of neurochemistry
- Publish Date: Sep 2007
- ISSN: 0022-3042
- Volume: 102
- Issue: 6
- Pages: 1863-74
- Medium: Print
- Language: English
- Citation (JAMA): He J, Wang T, Wang P, et al. A Novel Mechanism Underlying the Susceptibility of Neuronal Cells to Nitric Oxide: the Occurrence and Regulation of Protein S-nitrosylation is the Checkpoint.. J. Neurochem. Sep 2007;102:1863-74
Abstract
The susceptibility of neuronal cells to nitric oxide (NO) is a key issue in NO-mediated neurotoxicity. However, the underlying mechanism remains unclear. As a cyclic guanosine monophosphate (cGMP)-independent NO signaling pathway, S-nitrosylation (or S-nitrosation) has been suggested to occur as a post-translational modification in parallel with O-phosphorylation. The underlying mechanism of the involvement of protein S-nitrosylation in the susceptibility of neuronal cells to NO has been little investigated. In this study, we focused on the role of S-nitrosothiols (RSNO) in the susceptibility of a cerebellar cell line R2 to NO. Our results showed the following: (i) S-nitrosoglutathione (GSNO) induced a burst of RSNO in GSH-depleted R2 cells, the majority of which were primarily contributed by the S-nitrosylation of proteins (Pro-SNOs), and was followed by severe neuronal necrosis; (ii) the elevation in the level of Pro-SNOs resulted from a dysfunction of S-nitroglutathione reductase (GSNOR) as a result of its substrate, GSNO, being unavailable in GSH-depleted cells. In the meantime, the suppression of GSNOR increased NO-mediated neurotoxicity in R2 cells, as well as in cerebellar granule neurons; (iii) Our results also demonstrate that the burst of RSNO is the “checkpoint” of cell fate: if RSNO can be reduced to free thiol proteins, cells will survive; if they are further oxidized, cells will die; and (iv) GSH-ethyl ester and Vitamin C protected R2 cells against GSNO neurotoxicity through two distinct mechanisms: by inhibiting the elevation of Pro-SNOs and by reducing Pro-SNOs to free thiol proteins, respectively. A novel mechanism underlying the susceptibility of neuronal cells to NO is proposed and some potential strategies to prevent the NO-mediated neurotoxicity are discussed.
Mesh Headings (Keywords): Animals, Animals, Newborn, Brain, Cell Death, Cell Line, Cell Survival, Cells, Cultured, Cytoprotection, Glutathione, Nerve Tissue Proteins, Neurons, Nitric Oxide, Nitro Compounds, Oxidation-Reduction, Oxidative Stress, Rats, Rats, Sprague-Dawley, S-Nitrosoglutathione, Signal Transduction, Sulfhydryl Compounds
Check for Full Text / PubMed Unique Identifier (PMID): 17767703
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