scholarly journals Genetic Elimination of eNOS Reduces Secondary Complications of Experimental Subarachnoid Hemorrhage

2013 ◽  
Vol 33 (7) ◽  
pp. 1008-1014 ◽  
Author(s):  
Mohammed Sabri ◽  
Jinglu Ai ◽  
Elliot Lass ◽  
Josephine D'abbondanza ◽  
R Loch Macdonald
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Subarachnoid Hemorrhage ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Neuronal Degeneration ◽  
Secondary Complications ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
The Brain

Delayed complications of subarachnoid hemorrhage (SAH) such as angiographic vasospasm, cortical spreading ischemia, microcirculatory dysfunction, and microthrombosis are reported in both patients and animal models of SAH. We demonstrated previously that SAH is associated with increased oxidative stress in the brain parenchyma, and that this correlates with dysfunction of endothelial nitric oxide synthase (eNOS) (homodimeric uncoupling). Uncoupling of eNOS exacerbated oxidative stress and enhanced nitric oxide (NO) depletion, and was associated with multiple secondary complications such as microthrombosis, neuronal apoptosis, and release of reactive oxygen species. Thus, we hypothesized that genetic abbrogation of eNOS would confer a beneficial effect on the brain after SAH. Using a prechiasmatic injection model of SAH, we show here that eNOS knockout (KO) significantly alleviates vasospasm of the middle cerebral artery and reduces superoxide production. Endothelial nitric oxide synthase KO also affected other nitric oxide synthase isoforms. It significantly increases neuron nitric oxide synthase expression but has no effect on inducible nitric oxide synthase. Endothelial nitric oxide synthase KO decreases Zn2+ release after SAH, reduces microthrombi formation, and prevent neuronal degeneration. This work is consistent with our findings where, after SAH, increased oxidative stress can uncouple eNOS via Zn2+ thiolate oxidation, or theoretically by depletion or oxidation of tetrahydrobiopterin, resulting in a paradoxical release of superoxide anion radical, further exacerbating oxidative stress and microvascular damage.

scholarly journals Endothelial PPAR-γ provides vascular protection from IL-1β-induced oxidative stress

2016 ◽  
Vol 310 (1) ◽  
pp. H39-H48 ◽  
Author(s):  
Masashi Mukohda ◽  
Madeliene Stump ◽  
Pimonrat Ketsawatsomkron ◽  
Chunyan Hu ◽  
Frederick W. Quelle ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Nitric Oxide Synthase ◽  
Transgenic Mice ◽  
Stress Responses ◽  
Endothelial Nitric Oxide Synthase ◽  
Ppar Γ ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Loss of peroxisome proliferator-activated receptor (PPAR)-γ function in the vascular endothelium enhances atherosclerosis and NF-κB target gene expression in high-fat diet-fed apolipoprotein E-deficient mice. The mechanisms by which endothelial PPAR-γ regulates inflammatory responses and protects against atherosclerosis remain unclear. To assess functional interactions between PPAR-γ and inflammation, we used a model of IL-1β-induced aortic dysfunction in transgenic mice with endothelium-specific overexpression of either wild-type (E-WT) or dominant negative PPAR-γ (E-V290M). IL-1β dose dependently decreased IκB-α, increased phospho-p65, and increased luciferase activity in the aorta of NF-κB-LUC transgenic mice. IL-1β also dose dependently reduced endothelial-dependent relaxation by ACh. The loss of ACh responsiveness was partially improved by pretreatment of the vessels with the PPAR-γ agonist rosiglitazone or in E-WT. Conversely, IL-1β-induced endothelial dysfunction was worsened in the aorta from E-V290M mice. Although IL-1β increased the expression of NF-κB target genes, NF-κB p65 inhibitor did not alleviate endothelial dysfunction induced by IL-1β. Tempol, a SOD mimetic, partially restored ACh responsiveness in the IL-1β-treated aorta. Notably, tempol only modestly improved protection in the E-WT aorta but had an increased protective effect in the E-V290M aorta compared with the aorta from nontransgenic mice, suggesting that PPAR-γ-mediated protection involves antioxidant effects. IL-1β increased ROS and decreased the phospho-endothelial nitric oxide synthase (Ser1177)-to-endothelial nitric oxide synthase ratio in the nontransgenic aorta. These effects were completely abolished in the aorta with endothelial overexpression of WT PPAR-γ but were worsened in the aorta with E-V290M even in the absence of IL-1β. We conclude that PPAR-γ protects against IL-1β-mediated endothelial dysfunction through a reduction of oxidative stress responses but not by blunting IL-1β-mediated NF-κB activity.

scholarly journals Inflammatory Monocytes Determine Endothelial Nitric-oxide Synthase Uncoupling and Nitro-oxidative Stress Induced by Angiotensin II

2014 ◽  
Vol 289 (40) ◽  
pp. 27540-27550 ◽  
Author(s):  
Sabine Kossmann ◽  
Hanhan Hu ◽  
Sebastian Steven ◽  
Tanja Schönfelder ◽  
Daniela Fraccarollo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Inflammatory Monocytes ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

P4-061: INCREASED UREA LEVELS IN THE BRAIN OF ENDOTHELIAL NITRIC OXIDE SYNTHASE DEFICIENT MICE

2006 ◽  
Vol 14 (7S_Part_27) ◽  
pp. P1456-P1456
Author(s):  
Ashwini Hariharan ◽  
Yu Jing ◽  
Nicola D. Collie ◽  
Hu Zhang ◽  
Ping Liu
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
The Brain ◽  
Deficient Mice

scholarly journals Ac2-26 Alleviates Brain Injury after Cardiac Arrest and Cardiopulmonary Resuscitation in Rats via the eNOS Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jing Gong ◽  
Qi-Hang Tai ◽  
Guang-Xiao Xu ◽  
Xue-Ting Wang ◽  
Jing-Li Zhu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Brain Injury ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Saline Group ◽  
Related Factors ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
And Oxidative Stress

Background. Brain injury is the leading cause of death following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Ac2-26 and endothelial nitric oxide synthase (eNOS) have been shown to reduce neuroinflammation. This study is aimed at determining the mechanism by which Ac2-26 protects against inflammation during brain injury following CA and CPR. Methods. Sixty-four rats were randomized into sham, saline, Ac2-26, and Ac2-26+L-NIO (endothelial nitric oxide synthase (eNOS) inhibitor) groups. Rats received Ac2-26, Ac2-26+L-NIO, or saline after CPR. Neurologic function was assessed at baseline, 24, and 72 hours after CPR. At 72 hours after resuscitation, serum and brain tissues were collected. Results. Blood-brain barrier (BBB) permeability increased, and the number of surviving neurons and neurological function decreased in the saline group compared to the sham group. Anti-inflammatory and proinflammatory factors, neuron-specific enolase (NSE) levels, and the expression of eNOS, phosphorylated (p)-eNOS, inducible nitric oxide synthase (iNOS), and oxidative stress-related factors in the three CA groups significantly increased (P<0.05). BBB permeability decreased, and the number of surviving neurons and neurological function increased in the Ac2-26 group compared to the saline group (P<0.05). Ac2-26 increased anti-inflammatory and reduced proinflammatory markers, raised NSE levels, increased the expression of eNOS and p-eNOS, and reduced the expression of iNOS and oxidative stress-related factors compared to the saline group (P<0.05). The effect of Ac2-26 on brain injury was reversed by L-NIO (P<0.05). Conclusions. Ac2-26 reduced brain injury after CPR by inhibiting oxidative stress and neuroinflammation and protecting the BBB. The therapeutic effect of Ac2-26 on brain injury was largely dependent on the eNOS pathway.

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