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.

/pdf/enos-dependent-s-nitrosylation-of-the-nf-kb-subunit-p65-has-2jsebi93eh.pdf

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

Cell death by glutamate excitotoxicity, mediated by N-methyl-D-aspartate (NMDA) receptors, negatively impacts brain function affecting hippocampal, i.e. sensitive 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 (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 excitotoxicity.

https://www.biorxiv.org/content/biorxiv/early/2020/02/04/2020.02.04.932772.full.pdf

The eNOS-dependent S-nitrosylation of the NF-κB subunit p65 has neuroprotective consequences in excitotoxicity

Purpose Strokes are devastating as there are no current therapies to prevent long-term neurological deficits. Previous studies reported that cerebroprotein hydrolysate (CH) plays a role in neuronal protection in acute phase after ischemic stroke, while the long-term effects of CH upon brain plasticity and neurological outcomes after stroke are still uncertain. To address these gaps, we assessed the effect of a new cerebroprotein hydrolysate, CH1, on long-term gray and white matter integrity as well as axonal plasticity in the late phase after ischemic stroke and the potential mechanisms. Methods Adult male mice were subjected to permanent distal middle cerebral artery occlusion (dMCAO), followed by daily intraperitoneal injection of CH1 for 14 days. Motor function was measured weekly through behavioral neurological evaluations. Gray matter intensity and white matter intensity were examined by immunofluorescence staining. The sonic hedgehog (Shh) inhibitor cyclopamine (CYC) was injected to determine the involvement of the Shh pathway in the therapeutic effects of CH1. Results We found that intraperitoneal delivery of CH1, compared to vehicle administration, significantly improved long-term neurological outcomes at various times and promoted neuronal viability at 14 days but not at 28 days after stroke. Importantly, CH1 mitigated stroke-induced white matter injury and facilitated axonal plasticity in the late stage after stroke. Conclusion These results unveil a previously unappreciated role for CH in the repair of white matter and brain plasticity after stroke.

A Novel Cerebroprotein Hydrolysate, CH1, Ameliorates Chronic Focal Cerebral Ischemia Injury by Promoting White Matter Integrity via the Shh/Ptch-1/Gli-1 Signaling Pathway.

Objective Troxerutin is known for its anti-inflammatory and antioxidative effects in nerve impairment. The purpose of this study is to investigate the effect of troxerutin and cerebroprotein hydrolysate injections (TCHis) on prenatal valproic acid (VPA)-exposed rats. Methods The VPA was administered to pregnant rats on gestational day 12.5 to induce a model of autism. The offsprings were given the treatment of TCHis on postnatal day (PND) 21-50. On PND 43-50, the behavioral analysis of offsprings was performed after the treatment of TCHis for 1 h. On PND 50, the offsprings were harvested and the brains were collected. The hippocampus and prefrontal cortex were isolated for relevant biochemical detections. Results The administration of TCHis increased the pain sensitivity and improved abnormal social behaviors in prenatal VPA-exposed rats. Prenatal expose of VPA induced neuronal loss and apoptosis, enhanced reactive oxygen species (ROS) production, and promoted oxidative stress in hippocampus and prefrontal cortex, while these effects were reversed by the postnatal treatment of TCHis. In addition, postnatal administration of TCHis ameliorated mitochondrial function in hippocampus and prefrontal cortex of prenatal VPA-exposed rats. Conclusion This study concluded that postnatal treatment of TCHis reduced oxidative stress and ameliorated abnormal behavior in a prenatal VPA-induced rat model of autism.

TCHis mitigate oxidative stress and improve abnormal behavior in a prenatal valproic acid-exposed rat model of autism.

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.

/pdf/enos-dependent-s-nitrosylation-of-the-nf-kb-subunit-p65-has-d8w7o4ebdj.pdf

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

Purpose: Cerebral ischemic stroke, caused by obstruction of the blood flow to the brain, initiates a complex cascade of pathophysiological changes. The aim of the present study was to assess the protective role and the underlying mechanism of troxerutin and cerebroprotein hydrolysate (TCH) injections for five days in rats subjected to middle cerebral artery occlusion (MCAO).Materials and Methods: Male Sprague-Dawley rats treated with either TCH or a vehicle (0.9% saline) via intraperitoneal injection were examined one or three days after MCAO.Results: TCH alleviated neurological deficits and reduced infarct volume, innate immune response, blood-brain barrier destruction, and suppressed cell apoptosis. The therapeutic effects of TCH were achieved by diminished neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS), and increased endothelial nitric oxide synthase (eNOS). Furthermore, L-NAME showed an inhibitory effect against TCH after MCAO on eNOS expression, NO and peroxynitrite production, neurobehavioral score, and infarct volume.Conclusions: The results indicate that injection of TCH has multifaceted neuroprotective effects against MCAO via regulation of the various NOS isoforms.

Neuroprotective effects of troxerutin and cerebroprotein hydrolysate injection on the neurovascular unit in a rat model of Middle cerebral artery occlusion.

Yan Zhang

Papers

Neuroprotective effects of troxerutin and cerebroprotein hydrolysate injection on the neurovascular unit in a rat model of Middle cerebral artery occlusion.