ENOS-dependent S-nitrosylation of the NF-\u03baB subunit p65 has neuroprotective effects

Ariel Caviedes,Carlos Lafourcade,Ursula Wyneken,Barbara Maturana,Karl-Heinz Smalla,Manuel Varas-Godoy,Alexander Engler,Luis Federico Batiz,Thilo Kaehne,Felipe Gordillo,Katherina Corvalán

doi:10.1038/s41419-020-03338-4

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.

Highlights

Neuronal death by glutamate excitotoxicity is implicated in the pathogenesis of several neurological disorders, ranging from neurodegeneration to epilepsy, stroke, and traumatic brain injury[1,2]
Considering the novel finding that endothelial nitric oxide synthase (eNOS) is present in neurons and synapses[15], we examined whether eNOS is involved in p65 S-nitrosylation and, in the regulation of its transcriptional activity under excitotoxicitypromoting conditions
In this work, we show that eNOS-dependent p65

Summary

Introduction

Neuronal death by glutamate excitotoxicity is implicated in the pathogenesis of several neurological disorders, ranging from neurodegeneration to epilepsy, stroke, and traumatic brain injury[1,2]. The nuclear factor kappa B (NF-κB) family of transcription factors has been implicated in excitotoxicity in the retina, the striatum, cerebral cortex, and hippocampus[4,5,6]. This is associated with the induction of pro-apoptotic and eNOS is involved in p65 S-nitrosylation and, in the regulation of its transcriptional activity under excitotoxicitypromoting conditions. We found that eNOS contributes to p65 S-nitrosylation and is associated with neuroprotection. This homeostatic mechanism is Official journal of the Cell Death Differentiation Association

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