eNOS-dependent S-nitrosylation of the NF-κB subunit p65 has neuroprotective effects

Abstract

Cell death by glutamate excitotoxicity, mediated by N-methyl-d-aspartate (NMDA) receptors, negatively impacts brain function, including but not limited to hippocampal neurons. The NF-κB transcription factor (composed mainly of p65/p50 subunits) contributes to neuronal death in excitotoxicity, while its inhibition should improve cell survival. Using the biotin switch method, subcellular fractionation, immunofluorescence, and luciferase reporter assays, we found that NMDA-stimulated NF-κB activity selectively in hippocampal neurons, while endothelial nitric oxide synthase (eNOS), an enzyme expressed in neurons, is involved in the S-nitrosylation of p65 and consequent NF-κB inhibition in cerebrocortical, i.e., resistant neurons. The S-nitro proteomes of cortical and hippocampal neurons revealed that different biological processes are regulated by S-nitrosylation in susceptible and resistant neurons, bringing to light that protein S-nitrosylation is a ubiquitous post-translational modification, able to influence a variety of biological processes including the homeostatic inhibition of the NF-κB transcriptional activity in cortical neurons exposed to NMDA receptor overstimulation.

Artesunate and Tetramethylpyrazine Exert Effects on Experimental Cerebral Malaria in a Mechanism of Protein S-Nitrosylation

“…However, the S-nitrosylation of NMDA receptors resulted in decreased activity and inhibited downstream signaling pathways. 43 Following AS+TMP administration, we observed that SNO-NMDA receptors were increased, and the receptor activity might be inhibited to prevent calcium overload and thus protect neurons.…”

“…When ECM occurs, NMDA receptor activation increases glutamate metabolism and induces excitatory neurotoxicity, resulting in neuronal damage for the influx of large amounts of calcium ions. However, the S -nitrosylation of NMDA receptors resulted in decreased activity and inhibited downstream signaling pathways . Following AS+TMP administration, we observed that SNO-NMDA receptors were increased, and the receptor activity might be inhibited to prevent calcium overload and thus protect neurons.…”

S-Nitrosylation in Tumor Microenvironment

“…As a result, the NF-κB-IκB complex remains inactive in the cytoplasm. Furthermore, p50 and p65 subunits of the NF-κB heterodimer are also inactivated via S-nitrosylation at Cys62 and Cys38, respectively ( Figure 3 A) [ 158 , 189 ]. Inactivation of these subunits inhibits their DNA binding for gene transcription.…”

“…In particular, S-nitrosylation of caspase-1 inhibits the functions of NLR family pyrin domain containing 3 [NLRP3] inflammasome, which is an activation platform of caspase-1 [ 14 , 163 ]. It was shown that inhibiting NLRP3 inflammasome through caspase-1 S-nitrosylation was able to suppress angiogenesis, invasion and metastasis of melanoma and breast cancer cells [ 186 , 189 , 190 ].…”

Implications of Oxidative and Nitrosative Post-Translational Modifications in Therapeutic Strategies against Reperfusion Damage

“…PTM of proteins based on redox reactions is a sophisticated and efficient mechanism conserved throughout evolution, which regulates intracellular signaling. Such modifications change the biological activity of downstream targets, modifying cellular processes such as autophagy [ 2 ], the immune and antioxidant response [ 3 , 4 ], energy metabolism [ 5 ], protein folding and degradation [ 6 ], proliferation and differentiation [ 7 , 8 ], and also affect the activity of transcription factors through direct and indirect mechanisms [ 9 ].…”