Immune modulation by fish kinetoplastid parasites: a role for nitric oxide

Trypanoplasma borreli and Trypanosoma carassii are kinetoplastid parasites infecting cyprinid fish. We investigated the role of nitric oxide (NO) in immune modulation during T. borreli and T. carassii infection of carp. Phagocytic cells from different organs produced NO and serum nitrate levels increased, demonstrating that T. borreli activates NO production in vivo. In contrast, T. carassii did not induce NO production in vivo and inhibited LPS-induced NO production in vitro. Production of NO was detrimental to the host as T. borreli-infected carp treated with the inducible NO synthase inhibitor aminoguanidine had a higher survival than infected control carp. This detrimental effect can be explained (in part) by the toxicity of NO to cells in vitro as NO inhibited the proliferative response of blood and spleen leukocytes. Head-kidney phagocytes were resistant to the immunosuppressive effects of NO in vitro. The NO-inducing activity of T. borreli may be an adaptation developed to ensure survival and immune evasion in the fish host. Apparently, T. carassii has adopted another strategy by deactivating specific functions of phagocytes. Both strategies may ensure long-term survival of the parasite.

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Inhibition of Respiration by Nitric Oxide Induces a Mycobacterium tuberculosis Dormancy Program

Journal of Experimental Medicine ◽

10.1084/jem.20030205 ◽

2003 ◽

Vol 198 (5) ◽

pp. 705-713 ◽

Cited By ~ 642

Author(s):

Martin I. Voskuil ◽

Dirk Schnappinger ◽

Kevin C. Visconti ◽

Maria I. Harrell ◽

Gregory M. Dolganov ◽

...

Keyword(s):

Nitric Oxide ◽

Mycobacterium Tuberculosis ◽

Latent Tuberculosis ◽

No Synthase ◽

No Production ◽

Respiratory Pathway ◽

Latently Infected ◽

Synthase Inhibitor

An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis.

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

Czech Journal of Animal Science ◽

10.17221/8405-cjas ◽

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 µg 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 < 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 < 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 < 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 < 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.

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Abstract 18060: TRAIL Promotes Angiogenesis and Ischemia-Induced Neovascularisation via NOX4, H2O2 and Nitric Oxide-Dependent Mechanisms

Circulation ◽

10.1161/circ.130.suppl_2.18060 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Belinda A Di Bartolo ◽

Sian P Cartland ◽

Leonel Prado-Lourenco ◽

Nor Saadah M Azahri ◽

Thuan Thai ◽

...

Keyword(s):

Nitric Oxide ◽

Angiogenic Factor ◽

Tubule Formation ◽

Nitric Oxide Synthase Inhibitor ◽

Therapeutic Implications ◽

Synthase Inhibitor ◽

Oxide Synthase ◽

First Time

Background: Angiogenesis and neovascularization are essential processes that follow ischemia insults. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) not only induces endothelial cell (EC) death and inhibits angiogenesis, but also promotes EC migration, invasion and proliferation in vitro . These seemingly opposite effects make its role in angiogenesis in vivo unclear. Using TRAIL -/- and wild-type mice, we sought to determine the role of TRAIL in angiogenesis and neovascularisation. We also sought mechanisms in vitro . Methods and Results: Reduced vascularisation assessed by real-time in vivo 3D Vevo ultrasound imaging and CD31 staining was observed in TRAIL -/- mice 28 d after hindlimb ischemia. Moreover, reduced capillary formation and increased apoptosis was evident in TRAIL -/- muscles even at 3 d after ischemic surgery. We have previously shown that fibroblast growth factor-2 (FGF-2), a potent angiogenic factor, regulates TRAIL gene expression in vascular smooth muscle cells. Indeed, FGF-2 also regulates TRAIL expression in ECs, and FGF-2-inducible proliferation, migration and tubule formation was inhibited with siRNA targeting TRAIL. Notably, both FGF-2 and TRAIL significantly increased NOX4 expression. TRAIL-inducible angiogenic activity in ECs was inhibited with siRNAs targeting NOX4, and consistent with these, NOX4 mRNA was reduced in 3 d ischemic hindlimbs of TRAIL -/- mice. TRAIL stimulated intracellular H 2 O 2 levels in ECs, and TRAIL-inducible proliferation, migration and tubule formation was inhibited with not only PEG-catalase, a H 2 O 2 scavenger, but also blocked with L-NAME, a nitric oxide synthase inhibitor. Conclusions: This is the first demonstration showing that TRAIL promotes angiogenesis in vivo . We show for the first time that the TRAIL stimulates NOX4 expression to mediate nitric oxide-dependent angiogenic effects. This has significant therapeutic implications such that TRAIL may improve the angiogenic response to ischemia and increase perfusion recovery in patients with CVD and diabetes.

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In Vitro Study of Nitric Oxide Metabolites Effects on Human Hydatid ofEchinococcus granulosus

Journal of Parasitology Research ◽

10.1155/2009/624919 ◽

2009 ◽

Vol 2009 ◽

pp. 1-7 ◽

Cited By ~ 17

Author(s):

Razika Zeghir-Bouteldja ◽

Manel Amri ◽

Saliha Aitaissa ◽

Samia Bouaziz ◽

Dalila Mezioug ◽

...

Keyword(s):

Nitric Oxide ◽

Hydatid Cyst ◽

Echinococcus Granulosus ◽

In Vitro Study ◽

No Production ◽

In Vitro Effects ◽

Nitric Oxide Metabolites

Hydatidosis is characterized by the long-term coexistence of larvaEchinococcus granulosusand its host without effective rejection. Previous studies demonstrated nitric oxide (NO) production (in vivo and in vitro) during hydatidosis. In this study, we investigated the direct in vitro effects of NO species: nitrite (NO2−), nitrate (NO3−) and peroxynitrite (ONOO−) on protoscolices (PSCs) viability and hydatid cyst layers integrity for 24 hours and 48 hours. Our results showed protoscolicidal activity ofNO2−andONOO−24 hours and 3 hours after treatment with 320 μM and 80 μM respectively. Degenerative effects were observed on germinal and laminated layers. The comparison of the in vitro effects of NO species on the PSCs viability indicated thatONOO−is more cytotoxic thanNO2−. In contrast,NO3−has no effect. These results suggest possible involvement ofNO2−andONOO−in antihydatic action and point the efficacy of these metabolites as scolicidal agents.

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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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Sources and implications of basal nitric oxide in spontaneous contractions of guinea pig taenia caeci

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00273.2002 ◽

2003 ◽

Vol 285 (4) ◽

pp. G747-G753 ◽

Cited By ~ 5

Author(s):

Catalina Caballero-Alomar ◽

Carmen Santos ◽

Diego Lopez ◽

M. Teresa Mitjavila ◽

Pere Puig-Parellada

Keyword(s):

Nitric Oxide ◽

Guinea Pig ◽

Inhibitory Effect ◽

No Production ◽

Paramagnetic Resonance ◽

Synthase Inhibitor ◽

Spontaneous Contractions ◽

Electron Paramagnetic

We examined in vitro the source and role of basal nitric oxide (NO) in proximal segments of guinea pig taenia caeci in nonadrenergic, noncholinergic (NANC) conditions. Using electron paramagnetic resonance (EPR), we measured the effect of the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME, 10–4 M), the neuronal blocker tetrodotoxin (TTX, 10–6 M), or both on spontaneous contractions and on the production of basal NO. Both l-NAME and TTX, when tested alone, increased the amplitude and frequency of contractions. NO production was abolished by l-NAME and was inhibited by 38% by TTX. When tested together, l-NAME in the presence of TTX or TTX in the presence of l-NAME had no further effect on the amplitude or frequency of spontaneous contractions, and the NO production was inhibited. These findings suggest that basal NO consists of TTX-sensitive and TTX-resistant components. The TTX-sensitive NO has an inhibitory effect on spontaneous contractions; the role of TTX-resistant NO is unknown.

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In vitro and in vivo anti-inflammatory activities of a sterol-enriched fraction from freshwater green alga, Spirogyra sp.

Fisheries and Aquatic Sciences ◽

10.1186/s41240-020-00172-9 ◽

2020 ◽

Vol 23 (1) ◽

Author(s):

Lei Wang ◽

You-Jin Jeon ◽

Jae-Il Kim

Keyword(s):

Nitric Oxide ◽

Green Alga ◽

Raw 264.7 Cells ◽

Ros Generation ◽

Prostaglandin E ◽

No Production ◽

Raw 264.7 ◽

Anti Inflammatory

Abstract Background Inflammation plays a crucial role in the pathogenesis of many diseases such as arthritis and atherosclerosis. In the present study, we evaluated anti-inflammatory activity of sterol-rich fraction prepared from Spirogyra sp., a freshwater green alga, in an effort to find bioactive extracts derived from natural sources. Methods The sterol content of ethanol extract of Spirogyra sp. (SPE) was enriched by fractionation with hexane (SPEH), resulting 6.7 times higher than SPE. Using this fraction, the in vitro and in vivo anti-inflammatory activities were evaluated in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells and zebrafish. Results SPEH effectively and dose-dependently decreased the production of nitric oxide (NO) and prostaglandin E2 (PGE2). SPEH suppressed the production of pro-inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β through downregulating nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells without cytotoxicity. The in vivo test results indicated that SPEH significantly and dose-dependently reduced reactive oxygen species (ROS) generation, cell death, and NO production in LPS-stimulated zebrafish. Conclusions These results demonstrate that SPEH possesses strong in vitro and in vivo anti-inflammatory activities and has the potential to be used as healthcare or pharmaceutical material for the treatment of inflammatory diseases.

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Heme proteins mediate the conversion of nitrite to nitric oxide in the vascular wall

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00374.2008 ◽

2008 ◽

Vol 295 (2) ◽

pp. H499-H508 ◽

Cited By ~ 83

Author(s):

Wael F. Alzawahra ◽

M. A. Hassan Talukder ◽

Xiaoping Liu ◽

Alexandre Samouilov ◽

Jay L. Zweier

Keyword(s):

Nitric Oxide ◽

Heme Proteins ◽

Soluble Guanylyl Cyclase ◽

Vascular Wall ◽

Rat Aorta ◽

No Production ◽

Paramagnetic Resonance ◽

Physiological Importance

Nitric oxide (NO) has been shown to be the endothelium-derived relaxing factor (EDRF), and its impairment contributes to a variety of cardiovascular disorders. Recently, it has been recognized that nitrite can be an important source of NO; however, questions remain regarding the activity and mechanisms of nitrite bioactivation in vessels and its physiological importance. Therefore, we investigated the effects of nitrite on in vivo hemodynamics in rats and in vitro vasorelaxation in isolated rat aorta under aerobic conditions. Studies were performed to determine the mechanisms by which nitrite is converted to NO. In anesthetized rats, nitrite dose dependently decreased both systolic and diastolic blood pressure with a threshold dose of 10 μM. Similarly, nitrite (10 μM-2 mM) caused vasorelaxation of aortic rings, and NO was shown to be the intermediate factor responsible for this activity. With the use of electrochemical as well as electron paramagnetic resonance (EPR) spectroscopy techniques NO generation was measured from isolated aortic vessels following nitrite treatment. Reduction of nitrite to NO was blocked by heating the vessel, suggesting that an enzymatic process is involved. Organ chamber experiments demonstrated that aortic relaxation induced by nitrite could be blocked by both hemoglobin and soluble guanylyl cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ). In addition, both electrochemical and EPR spin-trapping measurements showed that ODQ inhibits nitrite-mediated NO production. These findings thus suggest that nitrite can be a precursor of EDRF and that sGC or other heme proteins inhibited by ODQ catalyze the reduction of nitrite to NO.

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The effects of disodium pamidronate on human polymorphonuclear leukocytes and platelets: An in vitro study

Cellular & Molecular Biology Letters ◽

10.2478/s11658-009-0012-6 ◽

2009 ◽

Vol 14 (3) ◽

Cited By ~ 5

Author(s):

Eleonora Salvolini ◽

Monia Orciani ◽

Arianna Vignini ◽

Roberto Primio ◽

Laura Mazzanti

Keyword(s):

Nitric Oxide ◽

In Vitro Study ◽

Protective Mechanism ◽

No Production ◽

Myeloperoxidase Activity ◽

Inflammatory Processes ◽

Anti Inflammatory ◽

Constitutive Nitric Oxide Synthase

AbstractRecent reports have indicated that, as well as having antiresorptive effects, bisphosphonates could have an application as anti-inflammatory drugs. Our aim was to investigate whether this anti-inflammatory action could be mediated by the nitric oxide (NO) released by the leukocytes migrating to the site of inflammation. In particular, we investigated in vitro the intracellular calcium concentration ([Ca2+]i), the level of NO released by PMN and platelets, and the PMN myeloperoxidase activity after incubation with disodium pamidronate, since there was a postulated modulatory effect of this aminosubstituted bisphosphonate on leukocytes both in vitro and in vivo. Our data shows that the pamidronate treatment provoked a significant increase in the [Ca2+]i parallel to the enhancement in NO release, suggesting a possible activation of constitutive nitric oxide synthase, while the myeloperoxidase activity was significantly reduced. In conclusion, we hypothesized that treatment with pamidronate could stimulate NO-production by cells present near the bone compartment, thus constituting a protective mechanism against bone resorption occurring during inflammation. In addition, PMN- and platelet-derived NO could act as a negative feed-back signal to restrict the inflammatory processes.

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Crambescin C1 Acts as A Possible Substrate of iNOS and eNOS Increasing Nitric Oxide Production and Inducing In Vivo Hypotensive Effect

Frontiers in Pharmacology ◽

10.3389/fphar.2021.694639 ◽

2021 ◽

Vol 12 ◽

Author(s):

Juan A. Rubiolo ◽

Emilio Lence ◽

Concepción González-Bello ◽

María Roel ◽

José Gil-Longo ◽

...

Keyword(s):

Nitric Oxide ◽

Active Site ◽

In Silico ◽

Hypotensive Effect ◽

Docking Studies ◽

No Production ◽

Guanidine Alkaloids ◽

Endogenous Substrate

Crambescins are guanidine alkaloids from the sponge Crambe crambe. Crambescin C1 (CC) induces metallothionein genes and nitric oxide (NO) is one of the triggers. We studied and compared the in vitro, in vivo, and in silico effects of some crambescine A and C analogs. HepG2 gene expression was analyzed using microarrays. Vasodilation was studied in rat aortic rings. In vivo hypotensive effect was directly measured in anesthetized rats. The targets of crambescines were studied in silico. CC and homo-crambescine C1 (HCC), but not crambescine A1 (CA), induced metallothioneins transcripts. CC increased NO production in HepG2 cells. In isolated rat aortic rings, CC and HCC induced an endothelium-dependent relaxation related to eNOS activation and an endothelium-independent relaxation related to iNOS activation, hence both compounds increase NO and reduce vascular tone. In silico analysis also points to eNOS and iNOS as targets of Crambescin C1 and source of NO increment. CC effect is mediated through crambescin binding to the active site of eNOS and iNOS. CC docking studies in iNOS and eNOS active site revealed hydrogen bonding of the hydroxylated chain with residues Glu377 and Glu361, involved in the substrate recognition, and explains its higher binding affinity than CA. The later interaction and the extra polar contacts with its pyrimidine moiety, absent in the endogenous substrate, explain its role as exogenous substrate of NOSs and NO production. Our results suggest that CC serve as a basis to develop new useful drugs when bioavailability of NO is perturbed.

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