Nitric Oxide as a Unique Bioactive Signaling Messenger in Physiology and Pathophysiology

Nitric oxide (NO) is an intra- and extracellular messenger that mediates diverse signaling pathways in target cells and is known to play an important role in many physiological processes including neuronal signaling, immune response, inflammatory response, modulation of ion channels, phagocytic defense mechanism, penile erection, and cardiovascular homeostasis and its decompensation in atherogenesis. Recent studies have also revealed a role for NO as signaling molecule in plant, as it activates various defense genes and acts as developmental regulator. In plants, NO can also be produced by nitrate reductase. NO can operate through posttranslational modification of proteins (nitrosylation). NO is also a causative agent in various pathophysiological abnormalities. One of the very important systems, the cardiovascular system, is affected by NO production, as this bioactive molecule is involved in the regulation of cardiovascular motor tone, modulation of myocardial contractivity, control of cell proliferation, and inhibition of platelet activation, aggregation, and adhesion. The prime source of NO in the cardiovascular system is endothelial NO synthase, which is tightly regulated with respect to activity and localization. The inhibition of chronic NO synthesis leads to neurogenic and arterial hypertensions, which later contribute to development of myocardial fibrosis. Overall, the modulation of NO synthesis is associated with hypertension. This review briefly describes the physiology of NO, its synthesis, catabolism, and targeting, the mechanism of NO action, and the pharmacological role of NO with special reference to its essential role in hypertension.

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

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180426121503 ◽

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.

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Disruption of renal peritubular blood flow in lipopolysaccharide-induced renal failure: role of nitric oxide and caspases

AJP Renal Physiology ◽

10.1152/ajprenal.00124.2005 ◽

2005 ◽

Vol 289 (6) ◽

pp. F1324-F1332 ◽

Cited By ~ 82

Author(s):

Manish M. Tiwari ◽

Robert W. Brock ◽

Judit K. Megyesi ◽

Gur P. Kaushal ◽

Philip R. Mayeux

Keyword(s):

Nitric Oxide ◽

Renal Failure ◽

Blood Flow ◽

Saline Group ◽

No Production ◽

Capillary Perfusion ◽

Peritubular Capillary ◽

Synthase Inhibitor ◽

Peritubular Capillary Perfusion

Acute renal failure (ARF) is a frequent and serious complication of endotoxemia caused by lipopolysaccharide (LPS) and contributes significantly to mortality. The present studies were undertaken to examine the roles of nitric oxide (NO) and caspase activation on renal peritubular blood flow and apoptosis in a murine model of LPS-induced ARF. Male C57BL/6 mice treated with LPS ( Escherichia coli) at a dose of 10 mg/kg developed ARF at 18 h. Renal failure was associated with a significant decrease in peritubular capillary perfusion. Vessels with no flow increased from 7 ± 3% in the saline group to 30 ± 4% in the LPS group ( P < 0.01). Both the inducible NO synthase inhibitor l- N6-1-iminoethyl-lysine (l-NIL) and the nonselective caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone (Z-VAD) prevented renal failure and reversed perfusion deficits. Renal failure was also associated with an increase in renal caspase-3 activity and an increase in renal apoptosis. Both l-NIL and Z-VAD prevented these changes. LPS caused an increase in NO production that was blocked by l-NIL but not by Z-VAD. Taken together, these data suggest NO-mediated activation of renal caspases and the resulting disruption in peritubular blood flow are an important mechanism of LPS-induced ARF.

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Role of nitric oxide in penile erection

Yonsei Medical Journal ◽

10.3349/ymj.1997.38.5.261 ◽

1997 ◽

Vol 38 (5) ◽

pp. 261 ◽

Cited By ~ 16

Author(s):

Hee Chang Jung ◽

Ki Hak Mun ◽

Tong Choon Park ◽

Yung Chang Lee ◽

Jong Min Park ◽

...

Keyword(s):

Nitric Oxide ◽

Penile Erection

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Nitrate reductases and hemoglobins control nitrogen-fixing symbiosis by regulating nitric oxide accumulation

Journal of Experimental Botany ◽

10.1093/jxb/eraa403 ◽

2020 ◽

Author(s):

Antoine Berger ◽

Alexandre Boscari ◽

Alain Puppo ◽

Renaud Brouquisse

Keyword(s):

Nitric Oxide ◽

Defense Responses ◽

Nodule Formation ◽

No Production ◽

Degradation Pathways ◽

Atmospheric Nitrogen ◽

Metabolic Intermediate ◽

Hypoxic Environment ◽

Nitrate Reductases

Abstract The interaction between legumes and rhizobia leads to the establishment of a symbiotic relationship between plant and bacteria. This is characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Nitric oxide (NO) accumulates at each stage of the symbiotic process. NO is involved in defense responses, nodule organogenesis and development, nitrogen fixation metabolism, and senescence induction. During symbiosis, either successively or simultaneously, NO regulates gene expression, modulates enzyme activities, and acts as a metabolic intermediate in energy regeneration processes via phytoglobin-NO respiration and the bacterial denitrification pathway. Due to the transition from normoxia to hypoxia during nodule formation, and the progressive presence of the bacterial partner in the growing nodules, NO production and degradation pathways change during the symbiotic process. This review analyzes the different source and degradation pathways of NO, and highlights the role of nitrate reductases and hemoproteins of both the plant and bacterial partners in the control of NO accumulation.

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Recent insights into nitrite signaling processes in blood

Biological Chemistry ◽

10.1515/hsz-2016-0263 ◽

2017 ◽

Vol 398 (3) ◽

pp. 319-329 ◽

Cited By ~ 9

Author(s):

Christine C. Helms ◽

Xiaohua Liu ◽

Daniel B. Kim-Shapiro

Keyword(s):

Nitric Oxide ◽

Human Physiology ◽

Blood Cell ◽

Red Blood Cell ◽

Nitrite Reduction ◽

No Production ◽

The Past ◽

Acidic Conditions ◽

Hypoxic Vasodilation

Abstract Nitrite was once thought to be inert in human physiology. However, research over the past few decades has established a link between nitrite and the production of nitric oxide (NO) that is potentiated under hypoxic and acidic conditions. Under this new role nitrite acts as a storage pool for bioavailable NO. The NO so produced is likely to play important roles in decreasing platelet activation, contributing to hypoxic vasodilation and minimizing blood-cell adhesion to endothelial cells. Researchers have proposed multiple mechanisms for nitrite reduction in the blood. However, NO production in blood must somehow overcome rapid scavenging by hemoglobin in order to be effective. Here we review the role of red blood cell hemoglobin in the reduction of nitrite and present recent research into mechanisms that may allow nitric oxide and other reactive nitrogen signaling species to escape the red blood cell.

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Losartan Increases No Production from the Bovine Aortic Wall That is Stimulated by Angiotensin II

European Journal of Inflammation ◽

10.1177/1721727x0300100304 ◽

2003 ◽

Vol 1 (3) ◽

pp. 113-117 ◽

Cited By ~ 1

Author(s):

M. Myronidou ◽

B. Kokkas ◽

A. Kouyoumtzis ◽

N. Gregoriadis ◽

A. Lourbopoulos ◽

...

Keyword(s):

Nitric Oxide ◽

Angiotensin Ii ◽

Aortic Wall ◽

Vascular Wall ◽

Protective Role ◽

Normal Function ◽

No Production ◽

Chemical Inactivation

In these studies we investigated if losartan, an AT1- receptor blocker has any beneficial effect on NO production from the bovine aortic preparations in vitro while under stimulation from angiotensin II. Experiments were performed on intact specimens of bovine thoracic aorta, incubated in Dulbeco's MOD medium in a metabolic shaker for 24 hours under 95 % O2 and 5 % CO2 at a temperature of 37°C. We found that angiotensin II 1nM−10 μM does not exert any statistically significant action on NO production. On the contrary, angiotensin II 10nM increases the production of NO by 58.14 % (from 12.16 + 2.9 μm/l to 19.23 + 4.2 μm/l in the presence of losartan 1nM (P<0.05). Nitric oxide levels depend on both rate production and rate catabolism or chemical inactivation. Such an equilibrium is vital for the normal function of many systems including the cardiovascular one. The above results demonstrate that the blockade of AT1-receptors favors the biosynthesis of NO and indicate the protective role of losartan on the vascular wall.

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Caspase Activation Is Required for Nitric Oxide–Mediated, CD95(APO-1/Fas)–Dependent and Independent Apoptosis in Human Neoplastic Lymphoid Cells

Blood ◽

10.1182/blood.v91.11.4311 ◽

1998 ◽

Vol 91 (11) ◽

pp. 4311-4320 ◽

Cited By ~ 57

Author(s):

Katerina Chlichlia ◽

Marcus E. Peter ◽

Marian Rocha ◽

Carsten Scaffidi ◽

Mariana Bucur ◽

...

Keyword(s):

Nitric Oxide ◽

Present Report ◽

Lymphoid Cells ◽

Jurkat Cells ◽

Target Cells ◽

No Production ◽

No Donor ◽

Synthase Inhibitor ◽

Inhibitor Of Protein Synthesis

Abstract Nitric oxide (NO), an important effector molecule involved in immune regulation and host defense, was shown to induce apoptosis in lymphoma cells. In the present report the NO donor glycerol trinitrate was found to induce apoptosis in Jurkat cells that are sensitive to CD95-mediated kill. In contrast, a CD95-resistant Jurkat subclone showed substantial protection from apoptosis after exposure to NO. NO induced mRNA expression of CD95 (APO-1/Fas) and TRAIL/APO-2 ligands. Moreover, NO triggered apoptosis in freshly isolated human leukemic lymphocytes which were also sensitive to anti-CD95 treatment. The ability of NO to induce apoptosis was completely blocked by a broad-spectrum ICE (interleukin-1β converting enzyme)-protease/caspase inhibitor and correlated with FLICE/caspase-8 activation. This activation was abrogated in some neoplastic lymphoid cells but not in others by the inhibitor of protein synthesis cycloheximide. Our results were confirmed using an in vitro experimental model of coculture of human lymphoid target cells with activated bovine endothelial cells generating NO as effectors. Furthermore, the inhibition of endogenous NO production with the inducible NO synthase inhibitor NG-monomethyl-L-arginine caused a complete abrogation of the apoptotic effect. Our data provide evidence that NO-induced apoptosis in human neoplastic lymphoid cells strictly requires activation of caspases, in particular FLICE, the most CD95 receptor-proximal caspase. Depending on the cell line tested this activation required or was independent of the CD95 receptor/ligand system.

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Does autonomic blockade reveal a potent contribution of nitric oxide to locomotion-induced vasodilation?

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2000.279.2.h726 ◽

2000 ◽

Vol 279 (2) ◽

pp. H726-H732 ◽

Cited By ~ 23

Author(s):

Don D. Sheriff ◽

Christopher D. Nelson ◽

Ryan K. Sundermann

Keyword(s):

Nitric Oxide ◽

Skeletal Muscle ◽

No Production ◽

Vascular Conductance ◽

Absolute Level ◽

Autonomic Blockade ◽

The Absolute ◽

Ganglionic Transmission ◽

Treadmill Locomotion

We sought to test the role of nitric oxide (NO) in governing skeletal muscle (iliac) vascular conductance during treadmill locomotion in dogs ( n = 6; 3.2 and 6.4 km/h at 0% grade, and 6.4 km/h at 10% grade). As seen previously, the increase in muscle vascular conductance accompanying treadmill locomotion was little influenced by NO synthase inhibition alone with N ω-nitro-l-arginine methyl ester (l-NAME, 10 mg/kg iv), but the absolute value of conductance achieved during locomotion was reduced. Such ambiguous results provide an unclear picture regarding the importance of NO during locomotion. However, muscle vasodilation is normally restrained by the sympathetic system during locomotion. Thus a significant contribution by NO to the increase in vascular conductance that accompanies locomotion could be masked by partial withdrawal of the competing influence of sympathetic vasoconstrictor nerve activity secondary to the rise in arterial pressure following systemicl-NAME administration. To test this possibility, we compared the rise in muscle vascular conductance before and afterl-NAME treatment while ganglionic transmission was blocked by hexamethonium. Under these conditions, l-NAME significantly reduced both the rise in vascular conductance (by 32%, P < 0.001) and the absolute level of vascular conductance (by 30%, P < 0.001) achieved during locomotion with no effect on blood flow. Thus augmented NO production normally provides a significant drive to relax vascular smooth muscle in active skeletal muscle during locomotion. Potential deficits stemming from the absence of NO following l-NAME treatment are masked by less intense sympathetic restraint when autonomic function is intact.

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Nitric Oxide Overproduction by cue1 Mutants Differs on Developmental Stages and Growth Conditions

Plants ◽

10.3390/plants9111484 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1484 ◽

Cited By ~ 1

Author(s):

Tamara Lechón ◽

Luis Sanz ◽

Inmaculada Sánchez-Vicente ◽

Oscar Lorenzo

Keyword(s):

Nitric Oxide ◽

Carbon Metabolism ◽

Root Elongation ◽

Developmental Stages ◽

Primary Root ◽

Carbon Sources ◽

Growth Conditions ◽

No Production

The cue1 nitric oxide (NO) overproducer mutants are impaired in a plastid phosphoenolpyruvate/phosphate translocator, mainly expressed in Arabidopsis thaliana roots. cue1 mutants present an increased content of arginine, a precursor of NO in oxidative synthesis processes. However, the pathways of plant NO biosynthesis and signaling have not yet been fully characterized, and the role of CUE1 in these processes is not clear. Here, in an attempt to advance our knowledge regarding NO homeostasis, we performed a deep characterization of the NO production of four different cue1 alleles (cue1-1, cue1-5, cue1-6 and nox1) during seed germination, primary root elongation, and salt stress resistance. Furthermore, we analyzed the production of NO in different carbon sources to improve our understanding of the interplay between carbon metabolism and NO homeostasis. After in vivo NO imaging and spectrofluorometric quantification of the endogenous NO levels of cue1 mutants, we demonstrate that CUE1 does not directly contribute to the rapid NO synthesis during seed imbibition. Although cue1 mutants do not overproduce NO during germination and early plant development, they are able to accumulate NO after the seedling is completely established. Thus, CUE1 regulates NO homeostasis during post-germinative growth to modulate root development in response to carbon metabolism, as different sugars modify root elongation and meristem organization in cue1 mutants. Therefore, cue1 mutants are a useful tool to study the physiological effects of NO in post-germinative growth.

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