Cross talk between S-nitrosylation and S-glutathionylation in control of the Na,K-ATPase regulation in hypoxic heart

2012 ◽  
Vol 303 (11) ◽  
pp. H1332-H1343 ◽  
Author(s):  
Sergej Yakushev ◽  
Mark Band ◽  
Martha C. Tissot van Patot ◽  
Max Gassmann ◽  
Aaron Avivi ◽  
...  

Oxygen-induced regulation of Na,K-ATPase was studied in rat myocardium. In rat heart, Na,K-ATPase responded to hypoxia with a dose-dependent inhibition in hydrolytic activity. Inhibition of Na,K-ATPase in hypoxic rat heart was associated with decrease in nitric oxide (NO) production and progressive oxidative stress. Accumulation of oxidized glutathione (GSSG) and decrease in NO availability in hypoxic rat heart were followed by a decrease in S-nitrosylation and upregulation of S-glutathionylation of the catalytic α-subunit of the Na,K-ATPase. Induction of S-glutathionylation of the α-subunit by treatment of tissue homogenate with GSSG resulted in complete inhibition of the enzyme in rat a myocardial tissue homogenate. Inhibitory effect of GSSG in rat sarcolemma could be significantly decreased upon activation of NO synthases. We have further tested whether oxidative stress and suppression of the Na,K-ATPase activity are observed in hypoxic heart of two subterranean hypoxia-tolerant blind mole species ( Spalax galili and Spalax judaei). In both hypoxia-tolerant Spalax species activity of the enzyme and tissue redox state were maintained under hypoxic conditions. However, localization of cysteines within the catalytic subunit of the Na,K-ATPase was preserved and induction of S-glutathionylation by GSSG in tissue homogenate inhibited the Spalax ATPase as efficiently as in rat heart. The obtained data indicate that oxygen-induced regulation of the Na,K-ATPase in the heart is mediated by a switch between S-glutathionylation and S-nitrosylation of the regulatory thiol groups localized at the catalytic subunit of the enzyme.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Seun F. Akomolafe ◽  
Ganiyu Oboh ◽  
Afolabi A. Akindahunsi ◽  
Ayodele J. Akinyemi ◽  
Oluwatosin G. Tade

Cissus populnea are plants associated with a myriad of medicinal uses in different parts of the world and are good sources of carotenoids, triterpenoids, and ascorbic acid. The antioxidant properties and inhibitory effect of water extractible phytochemicals from stem bark of C. populnea on FeSO4 and sodium nitroprusside- (SNP-) induced lipid peroxidation in rat testes were investigated in vitro. The results revealed that the extract was able to scavenge DPPH radical, chelate Fe2+ and also had a high reducing power. Furthermore, the incubation of the testes tissue homogenate in the presence of FeSO4 and SNP, respectively, caused a significant increase in the malondialdehyde (MDA) contents of the testes. However, the aqueous extract of the stem bark of C. populnea caused a significant decrease in the MDA contents of both Fe2+ (EC50 = 0.027 mg/mL) and SNP- (EC50 = 0.22 mg/mL) induced lipid peroxidation in the rat testes homogenates in a dose-dependent manner. The water extractible phytochemicals from C. populnea protect the testes from oxidative stress and this could be attributed to their high antioxidant activity: DPPH-scavenging ability, Fe2+-chelating and -reducing power. Therefore, oxidatively stress in testes could be potentially managed/prevented by this plant.


2019 ◽  
Vol 25 (2) ◽  
pp. 132-137
Author(s):  
Hamed Parsa Khankandi ◽  
Sahar Behzad ◽  
Shamim Sahranavard ◽  
Mina Rezvani ◽  
Naghmeh Tadris Hasani

Background: Nitric oxide and reactive nitrogen species play an important role in various pathological conditions like cancer, inflammation and neurodegeneration. As plants and natural compounds have a great potency of discovering lead compounds which might affect NO production during inflammation and various pathologies, we examined the effects of three medicinal plants native to Iran, on NO production during oxidative stress in PC12 cells. Methods: In this study, cell death and NO levels were measured by MTT and by Griess assay, respectively. Oxidative stress was induced by hydrogen peroxide and extracts of Astragalus jolderensis, Convolvulus commutatus and Salvia multicaulis were used as pretreatment in oxidative stressed PC12 cells. Results: A. jolderensis extract significantly suppressed NO production in 150 and 200 μg/ml concentrations and C. commutatus extract in all concentration inhibited NO production in stressed PC12 cells. In addition, the extract of S. multicaulis inhibited NO production during stress at all concentrations above 50 μg/ml. Besides, the extract of S. multicaulis showed protective effect at lower doses in stressed cells. Conclusion: According to the results, S. multicaulis inhibited NO production and protected cells from oxidative stress. Hence, S. multicaulis is a good candidate for further in vitro and in vivo investigations. A. jolderensis and C. commutatus also suppressed NO production during stress. Therefore, they could be noticed in experiments that centralize on the inhibition of NO production and drug discovery studies in the field of neurodegenerative and chronic inflammatory diseases.


2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.


2003 ◽  
Vol 2 (1) ◽  
pp. 93-94
Author(s):  
J BENDALL ◽  
P RATAJCZAK ◽  
T DAMY ◽  
E ROBIDEL ◽  
F MAROTTE ◽  
...  

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
SR Lee ◽  
S Lee ◽  
HJ Eom ◽  
HR Kang ◽  
JS Yu ◽  
...  

1998 ◽  
Vol 274 (1) ◽  
pp. C245-C252 ◽  
Author(s):  
Junsuke Igarashi ◽  
Masashi Nishida ◽  
Shiro Hoshida ◽  
Nobushige Yamashita ◽  
Hiroaki Kosaka ◽  
...  

The effects of nitric oxide (NO) produced by cardiac inducible NO synthase (iNOS) on myocardial injury after oxidative stress were examined. Interleukin-1β induced cultured rat neonatal cardiac myocytes to express iNOS. After induction of iNOS,l-arginine enhanced NO production in a concentration-dependent manner. Glutathione peroxidase (GPX) activity in myocytes was attenuated by elevated iNOS activity and by an NO donor, S-nitroso- N-acetyl-penicillamine (SNAP). Although NO production by iNOS did not induce myocardial injury, NO augmented release of lactate dehydrogenase from myocyte cultures after addition of H2O2(0.1 mM, 1 h). Inhibition of iNOS with Nω-nitro-l-arginine methyl ester ameliorated the effects of NO-enhancing treatments on myocardial injury and GPX activity. SNAP augmented the myocardial injury induced by H2O2. Inhibition of GPX activity with antisense oligodeoxyribonucleotide for GPX mRNA increased myocardial injury by H2O2. Results suggest that the induction of cardiac iNOS promotes myocardial injury due to oxidative stress via inactivation of the intrinsic antioxidant enzyme, GPX.


Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Pamela Maher

Although the hallmarks of Alzheimer’s disease (AD) are amyloid beta plaques and neurofibrillary tangles, there is growing evidence that neuroinflammation, mitochondrial dysfunction and oxidative stress play important roles in disease development and progression. A major risk factor for the development of AD is diabetes, which is also characterized by oxidative stress and mitochondrial dysfunction along with chronic, low-grade inflammation. Increasing evidence indicates that in immune cells, the induction of a pro-inflammatory phenotype is associated with a shift from oxidative phosphorylation (OXPHOS) to glycolysis. However, whether hyperglycemia also contributes to this shift is not clear. Several different approaches including culturing BV2 microglial cells in different carbon sources, using enzyme inhibitors and knocking down key pathway elements were used in conjunction with bacterial lipopolysaccharide (LPS) activation to address this question. The results indicate that while high glucose favors NO production, pro-inflammatory cytokine production is highest in the presence of carbon sources that drive OXPHOS. In addition, among the carbon sources that drive OXPHOS, glutamine is a very potent inducer of IL6 production. This effect is dampened in the presence of glucose. Together, these results may provide new prospects for the therapeutic manipulation of neuroinflammation in the context of diabetes and AD.


Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 2
Author(s):  
Gina De La Fuente ◽  
Marco Fontana ◽  
Valentina Asnaghi ◽  
Mariachiara Chiantore ◽  
Serena Mirata ◽  
...  

Inflammation and oxidative stress are part of the complex biological responses of body tissues to harmful stimuli. In recent years, due to the increased understanding that oxidative stress is implicated in several diseases, pharmaceutical industries have invested in the research and development of new antioxidant compounds, especially from marine environment sources. Marine seaweeds have shown the presence of many bioactive secondary metabolites, with great potentialities from both the nutraceutical and the biomedical point of view. In this study, 50%-ethanolic and DMSO extracts from the species C. amentacea var. stricta were obtained for the first time from seaweeds collected in the Ligurian Sea (north-western Mediterranean). The bioactive properties of these extracts were then investigated, in terms of quantification of specific antioxidant activities by relevant ROS scavenging spectrophotometric tests, and of anti-inflammatory properties in LPS-stimulated macrophages by evaluation of inhibition of inflammatory cytokines and mediators. The data obtained in this study demonstrate a strong anti-inflammatory effect of both C. amentacea extracts (DMSO and ethanolic). The extracts showed a very low grade of toxicity on RAW 264.7 macrophages and L929 fibroblasts and a plethora of antioxidant and anti-inflammatory effects that were for the first time thoroughly investigated. The two extracts were able to scavenge OH and NO radicals (OH EC50 between 392 and 454 μg/mL; NO EC50 between 546 and 1293 μg/mL), to partially rescue H2O2-induced RAW 264.7 macrophages cell death, to abate intracellular ROS production in H2O2-stimulated macrophages and fibroblasts and to strongly inhibit LPS-induced inflammatory mediators, such as NO production and IL-1α, IL-6, cyclooxygenase-2 and inducible NO synthase gene expression in RAW 264.7 macrophages. These results pave the way, for the future use of C. amentacea metabolites, as an example, as antioxidant food additives in antiaging formulations as well as in cosmetic lenitive lotions for inflamed and/or damaged skin.


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