scholarly journals Inhibition of NO Biosynthetic Activities during Rehydration of Ramalina farinacea Lichen Thalli Provokes Increases in Lipid Peroxidation

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 189 ◽  
Author(s):  
Joana R. Expósito ◽  
Sara Martín San Román ◽  
Eva Barreno ◽  
José Reig-Armiñana ◽  
Francisco José García-Breijo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lipid Peroxidation ◽  
Physcomitrella Patens ◽  
Specific Activity ◽  
Protein A ◽  
No Production ◽  
Symbiotic Associations ◽  
Diaphorase Activity ◽  
Oxide Synthase ◽  
Ramalina Farinacea

Lichens are poikilohydrous symbiotic associations between a fungus, photosynthetic partners, and bacteria. They are tolerant to repeated desiccation/rehydration cycles and adapted to anhydrobiosis. Nitric oxide (NO) is a keystone for stress tolerance of lichens; during lichen rehydration, NO limits free radicals and lipid peroxidation but no data on the mechanisms of its synthesis exist. The aim of this work is to characterize the synthesis of NO in the lichen Ramalina farinacea using inhibitors of nitrate reductase (NR) and nitric oxide synthase (NOS), tungstate, and NG-nitro-L-arginine methyl ester (L-NAME), respectively. Tungstate suppressed the NO level in the lichen and caused an increase in malondialdehyde during rehydration in the hyphae of cortex and in phycobionts, suggesting that a plant-like NR is involved in the NO production. Specific activity of NR in R. farinacea was 91 μU/mg protein, a level comparable to those in the bryophyte Physcomitrella patens and Arabidopsis thaliana. L-NAME treatment did not suppress the NO level in the lichens. On the other hand, NADPH-diaphorase activity cytochemistry showed a possible presence of a NOS-like activity in the microalgae where it is associated with cytoplasmatic vesicles. These data provide initial evidence that NO synthesis in R. farinacea involves NR.

The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Polymorphonuclear Neutrophils ◽  
Microbial Pathogens ◽  
Human Neutrophils ◽  
No Production ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

Inducible nitric oxide synthase augments injury elicited by oxidative stress in rat cardiac myocytes

1998 ◽  
Vol 274 (1) ◽  
pp. C245-C252 ◽  
Author(s):  
Junsuke Igarashi ◽  
Masashi Nishida ◽  
Shiro Hoshida ◽  
Nobushige Yamashita ◽  
Hiroaki Kosaka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Cardiac Myocytes ◽  
Myocardial Injury ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
No Donor ◽  
Oxide Synthase ◽  
Gpx Activity

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.

scholarly journals Effects of chitosan on nitric oxide production and inducible nitric oxide synthase activity and mRNA expression in weaned piglets

2018 ◽  
Vol 60 (No. 8) ◽  
pp. 359-366
Author(s):  
J. Li ◽  
B. Shi ◽  
S. Yan ◽  
L. Jin ◽  
Y. Guo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Inducible Nitric Oxide Synthase ◽  
No Production ◽  
Weaned Piglets ◽  
Inos Activity ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

The effects of chitosan on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity and gene expression in vivo or vitro were investigated in weaned piglets. In vivo, 180 weaned piglets were assigned to five dietary treatments with six replicates. The piglets were fed on a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. In vitro, the peripheral blood mononuclear cells (PBMCs) from a weaned piglet were cultured respectively with 0 (control), 40, 80, 160, and 320 &micro;g chitosan/ml medium. Results showed that serum NO concentrations on days 14 and 28 and iNOS activity on day 28 were quadratically improved with increasing chitosan dose (P &lt; 0.05). The iNOS mRNA expressions were linearly or quadratically enhanced in the duodenum on day 28, and were improved quadratically in the jejunum on days 14 and 28 and in the ileum on day 28 (P &lt; 0.01). In vitro, the NO concentrations, iNOS activity, and mRNA expression in unstimulated PBMCs were quadratically enhanced by chitosan, but the improvement of NO concentrations and iNOS activity by chitosan were markedly inhibited by N-(3-[aminomethyl] benzyl) acetamidine (1400w) (P&nbsp;&lt; 0.05). Moreover, the increase of NO concentrations, iNOS activity, and mRNA expression in PBMCs induced by lipopolysaccharide (LPS) were suppressed significantly by chitosan (P &lt; 0.05). The results indicated that the NO concentrations, iNOS activity, and mRNA expression in piglets were increased by feeding chitosan in a dose-dependent manner. In addition, chitosan improved the NO production in unstimulated PBMCs but inhibited its production in LPS-induced cells, which exerted bidirectional regulatory effects on the NO production via modulated iNOS activity and mRNA expression.

Hypothermia-induced cardioprotection using extended ischemia and early reperfusion cooling

2007 ◽  
Vol 292 (4) ◽  
pp. H1995-H2003 ◽  
Author(s):  
Zuo-Hui Shao ◽  
Wei-Tien Chang ◽  
Kim Chai Chan ◽  
Kim R. Wojcik ◽  
Chin-Wang Hsu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Therapeutic Hypothermia ◽  
Optimal Timing ◽  
No Production ◽  
Early Reperfusion ◽  
No Signaling ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Pkc Activation

Optimal timing of therapeutic hypothermia for cardiac ischemia is unknown. Our prior work suggests that ischemia with rapid reperfusion (I/R) in cardiomyocytes can be more damaging than prolonged ischemia alone. Also, these cardiomyocytes demonstrate protein kinase C (PKC) activation and nitric oxide (NO) signaling that confer protection against I/R injury. Thus we hypothesized that hypothermia will protect most using extended ischemia and early reperfusion cooling and is mediated via PKC and NO synthase (NOS). Chick cardiomyocytes were exposed to an established model of 1-h ischemia/3-h reperfusion, and the same field of initially contracting cells was monitored for viability and NO generation. Normothermic I/R resulted in 49.7 ± 3.4% cell death. Hypothermia induction to 25°C was most protective (14.3 ± 0.6% death, P < 0.001 vs. I/R control) when instituted during extended ischemia and early reperfusion, compared with induction after reperfusion (22.4 ± 2.9% death). Protection was completely lost if onset of cooling was delayed by 15 min of reperfusion (45.0 ± 8.2% death). Extended ischemia/early reperfusion cooling was associated with increased and sustained NO generation at reperfusion and decreased caspase-3 activation. The NOS inhibitor Nω-nitro-l-arginine methyl ester (200 μM) reversed these changes and abrogated hypothermia protection. In addition, the PKCε inhibitor myr-PKCε v1-2 (5 μM) also reversed NO production and hypothermia protection. In conclusion, therapeutic hypothermia initiated during extended ischemia/early reperfusion optimally protects cardiomyocytes from I/R injury. Such protection appears to be mediated by increased NO generation via activation of protein kinase Cε; nitric oxide synthase.

scholarly journals Decreased endothelial nitric oxide, systemic oxidative stress, and increased sympathetic modulation contribute to hypertension in obese rats

2014 ◽  
Vol 306 (10) ◽  
pp. H1472-H1480 ◽  
Author(s):  
Natalia Veronez da Cunha ◽  
Phileno Pinge-Filho ◽  
Carolina Panis ◽  
Bruno Rodrigues Silva ◽  
Laena Pernomian ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lipid Peroxidation ◽  
Endothelial Cells ◽  
Arterial Pressure ◽  
Vascular Reactivity ◽  
Monosodium Glutamate ◽  
Saline Control ◽  
Pulse Interval ◽  
No Production ◽  
Obese Rats

We investigated the involvement of nitric oxide (NO) and reactive oxygen species (ROS) on autonomic cardiovascular parameters, vascular reactivity, and endothelial cells isolated from aorta of monosodium glutamate (MSG) obese rats. Obesity was induced by administration of 4 mg/g body wt of MSG or equimolar saline [control (CTR)] to newborn rats. At the 60th day, the treatment was started with NG-nitro-l-arginine methyl ester (l-NAME, 20 mg/kg) or 0.9% saline. At the 90th day, after artery catheterization, mean arterial pressure (MAP) and heart rate were recorded. Plasma was collected to assess lipid peroxidation. Endothelial cells isolated from aorta were evaluated by flow cytometry and fluorescence intensity (FI) emitted by NO-sensitive dye [4,5-diaminofluoresceindiacetate (DAF-2DA)] and by ROS-sensitive dye [dihydroethidium (DHE)]. Vascular reactivity was made by concentration-response curves of acetylcholine. MSG showed hypertension compared with CTR. Treatment with l-NAME increased MAP only in CTR. The MSG induced an increase in the low-frequency (LF) band and a decrease in the high-frequency band of pulse interval. l-NAME treatment increased the LF band of systolic arterial pressure only in CTR without changes in MSG. Lipid peroxidation levels were higher in MSG and were attenuated after l-NAME. In endothelial cells, basal FI to DAF was higher in CTR than in MSG. In both groups, acetylcholine increased FI for DAF from basal. The FI baseline to DHE was higher in MSG than in CTR. Acetylcholine increased FI to DHE in the CTR group, but decreased in MSG animals. We suggest that reduced NO production and increased production of ROS may contribute to hypertension in obese MSG animals.

scholarly journals Protein kinase Cδ regulates endothelial nitric oxide synthase expression via Akt activation and nitric oxide generation

2008 ◽  
Vol 294 (3) ◽  
pp. L582-L591 ◽  
Author(s):  
Neetu Sud ◽  
Stephen Wedgwood ◽  
Stephen M. Black
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Promoter Activity ◽  
Dominant Negative ◽  
No Production ◽  
Enos Expression ◽  
Akt Activation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

In this study, we explore the roles of the delta isoform of PKC (PKCδ) in the regulation of endothelial nitric oxide synthase (eNOS) activity in pulmonary arterial endothelial cells isolated from fetal lambs (FPAECs). Pharmacological inhibition of PKCδ with either rottlerin or with the peptide, δV1-1, acutely attenuated NO production, and this was associated with a decrease in phosphorylation of eNOS at Ser1177 (S1177). The chronic effects of PKCδ inhibition using either rottlerin or the overexpression of a dominant negative PKCδ mutant included the downregulation of eNOS gene expression that was manifested by a decrease in both eNOS promoter activity and protein expression after 24 h of treatment. We also found that PKCδ inhibition blunted Akt activation as observed by a reduction in phosphorylated Akt at position Ser473. Thus, we conclude that PKCδ is actively involved in the activation of Akt. To determine the effect of Akt on eNOS signaling, we overexpressed a dominant negative mutant of Akt and determined its effect of NO generation, eNOS expression, and phosphorylation of eNOS at S1177. Our results demonstrated that Akt inhibition was associated with decreased NO production that correlated with reduced phosphorylation of eNOS at S1177, and decreased eNOS promoter activity. We next evaluated the effect of endogenously produced NO on eNOS expression by incubating FPAECs with the eNOS inhibitor 2-ethyl-2-thiopseudourea (ETU). ETU significantly inhibited NO production, eNOS promoter activity, and eNOS protein levels. Together, our data indicate involvement of PKCδ-mediated Akt activation and NO generation in maintaining eNOS expression.

scholarly journals Induction of nitric oxide synthesis in J774 cells lowers intracellular glutathione: effect of modulated glutathione redox status on nitric oxide synthase induction

1997 ◽  
Vol 322 (2) ◽  
pp. 477-481 ◽  
Author(s):  
John S. HOTHERSALL ◽  
Fernando Q. CUNHA ◽  
Guy H. NEILD ◽  
Alberto A. NOROHNA-DUTRA
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
De Novo ◽  
Redox Status ◽  
No Production ◽  
Duration Of Treatment ◽  
Intracellular Glutathione ◽  
J774 Cells ◽  
Oxide Synthase ◽  
Glutathione Redox

Under pathological conditions, the induction of nitric oxide synthase (NOS) in macrophages is responsible for NO production to a cytotoxic concentration. We have investigated changes to, and the role of, intracellular glutathione in NO production by the activated murine macrophage cell line J774. Total glutathione concentrations (reduced, GSH, plus the disulphide, GSSG) were decreased to 45% of the control 48 h after cells were activated with bacterial lipopolysaccharide plus interferon γ. This was accompanied by a decrease in the GSH/GSSG ratio from 12:1 to 2:1. The intracellular decrease was not accounted for by either GSH or GSSG efflux; on the contrary, rapid export of glutathione in control cells was abrogated during activation. The loss of intra- and extracellular glutathione indicates either a decrease in synthesis de novo, or an increase in utilization, rather than competition for available NADPH. All changes in activated cells were prevented by pretreatment with the NOS inhibitor l-N-(1-iminoethyl)ornithine. Basal glutathione levels in J774 cells were manipulated by pretreatment with (1) buthionine sulphoximine (glutathione synthase inhibitor), (2) acivicin (γ-glutamyltranspeptidase inhibitor), (3) bromo-octane (glutathione S-transferase substrate) and (4) diamide/zinc (thiol oxidant and glutathione reductase inhibitor). All treatments significantly decreased the output of NO following activation. The degree of inhibition was dependent on (i) duration of treatment prior to activation, (ii) rate of depletion or subsequent recovery and (iii) thiol end product. The level of GSH did not significantly affect the production of NO, after induction of NOS. Thus, glutathione redox status appears to plays an important role in NOS induction during macrophage activation.

Abstract 085: CHIP: E3 Ubiquitin Ligase Mediates Proteasomal Degradation of Neuronal Nitric Oxide Synthase in the Paraventricular Nucleus of Rats with Heart Failure

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Neeru M Sharma ◽  
Kenichi Katsurada ◽  
Xuefei Liu ◽  
Kaushik P Patel
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Nitric Oxide Synthase ◽  
Paraventricular Nucleus ◽  
Ubiquitin Ligase ◽  
Protein A ◽  
Neuronal Nitric Oxide Synthase ◽  
Proteasomal Degradation ◽  
Oxide Synthase

The exaggerated sympathetic drive is a characteristic of heart failure (HF) due to reduced neuronal nitric oxide synthase (nNOS) within the paraventricular nucleus (PVN). Previously we have shown that there were increased accumulation of nNOS-ubiquitin (nNOS-Ub) conjugates in the PVN of rats with HF (1.0±0.05 Sham vs. 1.29±0.06 HF) due to the increased levels of PIN (a protein inhibitor of nNOS, known to dissociate nNOS dimers into monomers) (0.76±0.10 Sham vs. 1.12±0.09 HF) and decreased levels of tetrahydrobiopterin (BH4): a cofactor required for stabilization of nNOS dimers (0.62±0.02 Sham vs. 0.44±0.03 HF). We also showed that there is blunted nitric oxide-mediated inhibition of sympathetic tone via the PVN in HF. Here we examined whether CHIP(C-terminus of Hsp70 -interacting protein), a chaperone-dependent E3 ubiquitin-protein isopeptide ligase known to ubiquitylate Hsp90-chaperoned proteins could act as an ubiquitin ligase for nNOS in the PVN. Immunofluorescence studies revealed colocalization of nNOS and CHIP in the PVN indicating their possible interaction. CHIP expression was increased by 50% in the PVN of rats with HF(0.96±0.08 Sham vs.1.44±0.10* HF). It is shown that Hsp90 protects nNOS from ubiquitination while Hsp70 promotes the ubiquitination and degradation. We observed significant upregulation of Hsp70 (0.49±0.03 Sham vs. 0.65±0.02* HF) with a trend toward the decrease in Hsp90 expression (0.90±0.07 Sham vs. 0.71±0.06 HF). The opposing effects of the two chaperones could account for the increased CHIP-mediated ubiquitination and degradation of dysfunctional nNOS monomers in the PVN of rats with HF. Furthermore, neuronal NG108-15 cell line transfected with the pCMV3-CHIP-GFP spark (CHIP overexpression plasmid) showed approximately 74% increase in CHIP with concomitant 49% decrease in nNOS expression. In vitro ubiquitination assay in NG108 cells transfected with pCMV-(HA-Ub) 8 and pCMV3-CHIP-GFP spark plasmid reveal increased HA-Ub-nNOS conjugates (1.13 ± 0.09 Scramble vs. 1.65 ± 0.12* CHIP plasmid). Taken together, our results identify CHIP as an E3 ligase for ubiquitination of dysfunctional nNOS and CHIP expression is augmented during HF leading to increased proteasomal degradation of nNOS in the PVN.

Developmental changes in nitric oxide synthase isoform expression and nitric oxide production in fetal baboon lung

2002 ◽  
Vol 283 (6) ◽  
pp. L1192-L1199 ◽  
Author(s):  
Philip W. Shaul ◽  
Sam Afshar ◽  
Linda L. Gibson ◽  
Todd S. Sherman ◽  
Jay D. Kerecman ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Critical Role ◽  
Perinatal Period ◽  
Postnatal Period ◽  
Developmental Changes ◽  
No Production ◽  
Third Trimester ◽  
Isoform Expression ◽  
Oxide Synthase ◽  
Nos Isoforms

Nitric oxide (NO), produced by NO synthase (NOS), plays a critical role in multiple processes in the lung during the perinatal period. To better understand the regulation of pulmonary NO production in the developing primate, we determined the cell specificity and developmental changes in NOS isoform expression and action in the lungs of third-trimester fetal baboons. Immunohistochemistry in lungs obtained at 175 days (d) of gestation (term = 185 d) revealed that all three NOS isoforms, neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS), are primarily expressed in proximal airway epithelium. In proximal lung, there was a marked increase in total NOS enzymatic activity from 125 to 140 d gestation due to elevations in nNOS and eNOS, whereas iNOS expression and activity were minimal. Total NOS activity was constant from 140 to 175 d gestation, and during the latter stage (160–175 d gestation), a dramatic fall in nNOS and eNOS was replaced by a rise in iNOS. Studies done within 1 h of delivery at 125 or 140 d gestation revealed that the principal increase in NOS during the third trimester is associated with an elevation in exhaled NO levels, a decline in expiratory resistance, and greater pulmonary compliance. Thus, there are developmental increases in pulmonary NOS expression and NO production during the early third trimester in the primate that may enhance airway and parenchymal function in the immediate postnatal period.

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