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Sample records for induced inducible nitric

  1. Inducible nitric oxide synthase and inflammation.

    PubMed

    Salvemini, D; Marino, M H

    1998-01-01

    Nitric oxide (NO), derived from L-arginine (L-Arg) by the enzyme nitric oxide synthase (NOS), is involved in acute and chronic inflammatory events. In view of the complexity associated with the inflammatory response, the dissection of possible mechanisms by which NO modulates this response will be profitable in designing novel and more efficacious NOS inhibitors. In this review we describe the consequences associated with the induction of inducible nitric oxide synthase (iNOS) and its therapeutic implications. PMID:15991919

  2. Nitric oxide-induced calcium release

    PubMed Central

    Kakizawa, Sho; Yamazawa, Toshiko; Iino, Masamitsu

    2013-01-01

    Ryanodine receptors (RyRs), located in the sarcoplasmic/endoplasmic reticulum (SR/ER) membrane, are required for intracellular Ca2+ release that is involved in a wide range of cellular functions. In addition to Ca2+-induced Ca2+ release in cardiac cells and voltage-induced Ca2+ release in skeletal muscle cells, we recently identified another mode of intracellular Ca2+ mobilization mediated by RyR, i.e., nitric oxide-induced Ca2+ release (NICR), in cerebellar Purkinje cells. NICR is evoked by neuronal activity, is dependent on S-nitrosylation of type 1 RyR (RyR1) and is involved in the induction of long-term potentiation (LTP) of cerebellar synapses. In this addendum, we examined whether peroxynitrite, which is produced by the reaction of nitric oxide with superoxide, may also have an effect on the Ca2+ release via RyR1 and the cerebellar LTP. We found that scavengers of peroxynitrite have no significant effect either on the Ca2+ release via RyR1 or on the cerebellar LTP. We also found that an application of a high concentration of peroxynitrite does not reproduce neuronal activity-dependent Ca2+ release in Purkinje cells. These results support that NICR is induced by endogenous nitric oxide produced by neuronal activity through S-nitrosylation of RyR1. PMID:23247505

  3. Nitric oxide inhibition sustains vasopressin-induced vasoconstriction.

    PubMed Central

    Dworkin, M. J.; Carnochan, P.; Allen-Mersh, T. G.

    1995-01-01

    Hepatic parenchymal vasoconstriction increases cytotoxic drug uptake into hepatic metastases by increasing the tumour to liver blood flow ratio. Prolonged infusion of the vasoconstrictor vasopressin does not result in sustained vasoconstriction, and this may limit the benefit of vasopressin in infusional chemotherapy. We have assessed whether loss of vasopressin-induced vasoconstriction is mediated by nitric oxide. Hepatic and tumour blood flow were continuously monitored, in an animal hepatic tumour model, by laser Doppler flowmetry. The response to regionally infused vasopressin and the nitric oxide inhibitor N-nitro-L-arginine methyl ester (L-NAME) were assessed over a 30 min infusion period. The vasopressin-induced vasoconstrictor effect diminished after 15 min despite continued infusion. Vasoconstriction was significantly prolonged when L-NAME was infused in addition to vasopressin. The increase in tumour to normal blood flow ratio was greater over the infusion period when L-NAME was co-administered with vasopressin. Our results suggest that the loss of vasopressin-induced vasoconstriction seen in liver parenchyma after regional infusion is prevented by the nitric oxide synthase inhibitor L-name and may be mediated by nitric oxide. PMID:7734317

  4. UV Induced Oxidation of Nitric Oxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde, F. (Inventor); Luecke, Dale E. (Inventor)

    2007-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated at least in part using in situ UV radiation sources. The sources of the oxidizing species include oxygen and/or hydrogen peroxide. The oxygen may be a component of the gaseous stream or added to the gaseous stream, preferably near a UV radiation source, and is converted to ozone by the UV irradiation. The hydrogen peroxide is decomposed through a combination of vaporization and UV irradiation. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50% by volume and increased in concentration in a continuous process preceding vaporization within the flow channel of the gaseous stream and in the presence of the UV radiation sources.

  5. Endostatin induces acute endothelial nitric oxide and prostacyclin release

    SciTech Connect

    Li Chunying; Harris, M. Brennan; Venema, Virginia J.; Venema, Richard C. . E-mail: rvenema@mcg.edu

    2005-04-15

    Chronic exposure to endostatin (ES) blocks endothelial cell (EC) proliferation, and migration and induces EC apoptosis thereby inhibiting angiogenesis. Nitric oxide (NO) and prostacyclin (PGI{sub 2}), in contrast, play important roles in promoting angiogenesis. In this study, we examined the acute effects of ES on endothelial NO and PGI{sub 2} production. Unexpectedly, a cGMP reporter cell assay showed that ES-induced acute endothelial NO release in cultured bovine aortic endothelial cells (BAECs). Enzyme immunoassay showed that ES also induced an acute increase in PGI{sub 2} production in BAECs. These results were confirmed by ex vivo vascular ring studies that showed vascular relaxation in response to ES. Immunoblot analysis showed that ES stimulated acute phosphorylation of endothelial nitric oxide synthase (eNOS) at Ser116, Ser617, Ser635, and Ser1179, and dephosphorylation at Thr497 in BAECs, events associated with eNOS activation. Short-term exposure of EC to ES, therefore, unlike long-term exposure which is anti-angiogenic, may be pro-angiogenic.

  6. Role of inducible nitric oxide synthase-derived nitric oxide in lipopolysaccharide plus interferon-gamma-induced pulmonary inflammation.

    PubMed

    Zeidler, Patti C; Millecchia, Lyndell M; Castranova, Vincent

    2004-02-15

    Exposure of mice to lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma) increases nitric oxide (NO) production, which is proposed to play a role in the resulting pulmonary damage and inflammation. To determine the role of inducible nitric oxide synthase (iNOS)-induced NO in this lung reaction, the responses of inducible nitric oxide synthase knockout (iNOS KO) versus C57BL/6J wild-type (WT) mice to aspirated LPS + IFN-gamma were compared. Male mice (8-10 weeks) were exposed to LPS (1.2 mg/kg) + IFN-gamma (5000 U/mouse) or saline. At 24 or 72 h postexposure, lungs were lavaged with saline and the acellular fluid from the first bronchoalveolar lavage (BAL) was analyzed for total antioxidant capacity (TAC), lactate dehydrogenase (LDH) activity, albumin, tumor necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and AM zymosan-stimulated chemiluminescence (AM-CL). Pulmonary responses 24 h postexposure to LPS + IFN-gamma were characterized by significantly decreased TAC, increased BAL AMs and PMNs, LDH, albumin, TNF-alpha, and MIP-2, and enhanced AM-CL to the same extent in both WT and iNOS KO mice. Responses 72 h postexposure were similar; however, significant differences were found between WT and iNOS KO mice. iNOS KO mice demonstrated a greater decline in total antioxidant capacity, greater BAL PMNs, LDH, albumin, TNF-alpha, and MIP-2, and an enhanced AM-CL compared to the WT. These data suggest that the role of iNOS-derived NO in the pulmonary response to LPS + IFN-gamma is anti-inflammatory, and this becomes evident over time. PMID:14962504

  7. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    PubMed Central

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural

    2016-01-01

    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders. PMID:27382570

  8. In vivo Expression of Inducible Nitric Oxide Synthase in Experimentally Induced Neurologic Diseases

    NASA Astrophysics Data System (ADS)

    Koprowski, Hilary; Zheng, Yong Mu; Heber-Katz, Ellen; Fraser, Nigel; Rorke, Lucy; Fu, Zhen Fang; Hanlon, Cathleen; Dietzschold, Bernhard

    1993-04-01

    The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

  9. Shear-Induced Nitric Oxide Production by Endothelial Cells.

    PubMed

    Sriram, Krishna; Laughlin, Justin G; Rangamani, Padmini; Tartakovsky, Daniel M

    2016-07-12

    We present a biochemical model of the wall shear stress-induced activation of endothelial nitric oxide synthase (eNOS) in an endothelial cell. The model includes three key mechanotransducers: mechanosensing ion channels, integrins, and G protein-coupled receptors. The reaction cascade consists of two interconnected parts. The first is rapid activation of calcium, which results in formation of calcium-calmodulin complexes, followed by recruitment of eNOS from caveolae. The second is phosphorylation of eNOS by protein kinases PKC and AKT. The model also includes a negative feedback loop due to inhibition of calcium influx into the cell by cyclic guanosine monophosphate (cGMP). In this feedback, increased nitric oxide (NO) levels cause an increase in cGMP levels, so that cGMP inhibition of calcium influx can limit NO production. The model was used to predict the dynamics of NO production by an endothelial cell subjected to a step increase of wall shear stress from zero to a finite physiologically relevant value. Among several experimentally observed features, the model predicts a highly nonlinear, biphasic transient behavior of eNOS activation and NO production: a rapid initial activation due to the very rapid influx of calcium into the cytosol (occurring within 1-5 min) is followed by a sustained period of activation due to protein kinases. PMID:27410748

  10. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    NASA Technical Reports Server (NTRS)

    Holstein, Gay R.

    2003-01-01

    The goal of this research project was to identify the neurons and circuits in the vestibular nuclei and nucleus prepositus hypoglossi that utilize nitric oxide (NO) for intercellular signaling during gravity-induced plasticity. This objective was pursued using histochemical and immunocytochemical approaches to localize NO-producing neurons and characterize the fine morphology of the cells in ground-based studies of normal rats, rats adapted to hypergravity, and rats adapted to hypergravity and then re-adapted to the 1G environment. NO-producing neurons were identified and studied using four methodologies: i) immunocytochemistry employing polyclonal antibodies directed against neuronal nitric oxide synthase (nNOS), to provide an indication of the capacity of a cell for NO production; ii) immunocytochemistry employing a monoclonal antibody directed against L-citrulline, to provide an indirect index of the enzyme's activity; iii) histochemistry based on the NADPH-diaphorase reaction, for fuI1 cytological visualization of neurons; and iv) double immunofluorescence to co-localize nNOS and L-citrulline in individual vestibular nuclei (VN) and neurons.

  11. microRNA and human inducible nitric oxide synthase.

    PubMed

    Guo, Zhong; Geller, David A

    2014-01-01

    Regulation of human inducible nitric oxide synthase (iNOS) expression involves both transcriptional and posttranscriptional mechanisms. Human iNOS gene transcription is controlled in a cell type-specific manner by extracellular cytokines. Transcriptional regulation of human iNOS gene involves transcription factors NF-κB, Stat-1, AP-1, C/EBPβ, KLF6, Oct 1, and NRF. Important posttranscriptional mechanisms also regulate human iNOS mRNA stability through RNA binding proteins HuR, TTP, KSRP, and PABP. Recently, there are several miRNAs that were validated to regulate human and rodent iNOS gene expression. Among them, miR-939 and miR-26a were identified to bind with the human iNOS 3'-UTR and exert a translational blockade of human iNOS protein synthesis. PMID:25189382

  12. Thermoregulatory role of inducible nitric oxide synthase in lipopolysaccharide-induced hypothermia.

    PubMed

    Saia, Rafael S; Carnio, Evelin C

    2006-09-01

    We have tested the hypothesis that nitric oxide (NO) arising from inducible nitric oxide synthase (iNOS) plays a role in hypothermia during endotoxemia by regulating vasopressin (AVP) release. Wild-type (WT) and iNOS knockout mice (KO) were intraperitoneally injected with either saline or Escherichia coli lipopolysaccharide (LPS) 10.0 mg/kg in a final volume of 0.02 mL. Body temperature was measured continuously by biotelemetry during 24 h after injection. Three hours after LPS administration, we observed a significant drop in body temperature (hypothermic response) in WT mice, which remained until the seventh hour, returning then close to the basal level. In iNOS KO mice, we found a significant fall in body temperature after the fourth hour of LPS administration; however, the hypothermic response persisted until the end of the 24 h of the experiment. The pre-treatment with beta-mercapto-beta,beta-cyclopentamethylenepropionyl(1), O-Et-Tyr2, Val4, Arg8-Vasopressin, an AVP V1 receptor antagonist (10 microg/kg) administered intraperitoneally, abolished the persistent hypothermia induced by LPS in iNOS KO mice, suggesting the regulation of iNOS under the vasopressin release in this experimental model. In conclusion, our data suggest that the iNOS isoform plays a role in LPS-induced hypothermia, apparently through the regulation of AVP release. PMID:16714035

  13. Lycopene inhibits LPS-induced proinflammatory mediator inducible nitric oxide synthase in mouse macrophage cells.

    PubMed

    Rafi, Mohamed M; Yadav, Prem Narayan; Reyes, Marynell

    2007-01-01

    Lycopene is a fat-soluble red-orange carotenoid found primarily in tomatoes and tomato-derived products, including tomato sauce, tomato paste, and ketchup, and other dietary sources, including dried apricots, guava, watermelon, papaya, and pink grapefruit. In this study, we have demonstrated the molecular mechanism underlying the anti-inflammatory properties of lycopene using a mouse macrophage cell line (RAW 264.7). Treatment with lycopene (10 microM) inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production (40% compared with the control). Western blotting and reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that lycopene treatment decreased LPS-induced inducible nitric oxide synthase (iNOS) protein and mRNA expression in RAW 264.7 cells, respectively. These results suggest that lycopene has anti-inflammatory activity by inhibiting iNOS proteins and mRNA expressions in mouse macrophage cell lines. Furthermore, cyclooxygenase-2 (COX-2) protein and mRNA expression were not affected by treatment with lycopene. PMID:17995901

  14. Nitric oxide induces caspase activity in boar spermatozoa.

    PubMed

    Moran, J M; Madejón, L; Ortega Ferrusola, C; Peña, F J

    2008-07-01

    Nitric oxide (NO) is a highly reactive free radical that plays a key role in intra- and intercellular signaling. Production of radical oxygen species and an apoptotic-like phenomenon have recently been implicated in cryodamage during sperm cryopreservation. The objective of the present study was to evaluate the effect of sodium nitroprusside (SNP), an NO donor, on boar sperm viability. Semen samples were pooled from four boars that were routinely used for artificial insemination. Flow cytometry was used to compare semen incubated with SNP to control semen. Specifically, NO production was measured using the NO indicator dye diaminofluorescein diacetate, and caspase activity was determined using the permeable pan-caspase inhibitor Z-VAD linked to FITC. SNP induced a significant increase in the percentage of sperm cells showing caspase activity, from 9.3% in control samples to 76.2% in SNP-incubated samples (P<0.01). This study suggests that NO is a major free radical involved in boar sperm damage. PMID:18433854

  15. Inducible nitric oxide synthase is expressed in synovial fluid granulocytes

    PubMed Central

    CEDERGREN, J; FORSLUND 2, T; SUNDQVIST 2, T; SKOGH 1, T

    2002-01-01

    The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure l-arginine and l-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess’ reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0·001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. l-arginine was elevated in SF compared to serum (257 ± 78 versus 176 ± 65 µmol/l, P = 0·008), whereas a slight increase in l-citrulline (33 ± 11 versus 26 ± 9 µmol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19·2 ± 20·7 versus 8·6 ± 6·5 µmol/l, P = 0·054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis. PMID:12296866

  16. Involvement of inducible nitric oxide synthase in radiation-induced vascular endothelial damage.

    PubMed

    Hong, Chang-Won; Kim, Young-Mee; Pyo, Hongryull; Lee, Joon-Ho; Kim, Suwan; Lee, Sunyoung; Noh, Jae Myoung

    2013-11-01

    The use of radiation therapy has been linked to an increased risk of cardiovascular disease. To understand the mechanisms underlying radiation-induced vascular dysfunction, we employed two models. First, we examined the effect of X-ray irradiation on vasodilation in rabbit carotid arteries. Carotid arterial rings were irradiated with 8 or 16 Gy using in vivo and ex vivo methods. We measured the effect of acetylcholine-induced relaxation after phenylephrine-induced contraction on the rings. In irradiated carotid arteries, vasodilation was significantly attenuated by both irradiation methods. The relaxation response was completely blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a potent inhibitor of soluble guanylate cyclase. Residual relaxation persisted after treatment with L-N(ω)-nitroarginine (L-NA), a non-specific inhibitor of nitric oxide synthase (NOS), but disappeared following the addition of aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS). The relaxation response was also affected by tetraethylammonium, an inhibitor of endothelium-derived hyperpolarizing factor activity. In the second model, we investigated the biochemical events of nitrosative stress in human umbilical-vein endothelial cells (HUVECs). We measured iNOS and nitrotyrosine expression in HUVECs exposed to a dose of 4 Gy. The expression of iNOS and nitrotyrosine was greater in irradiated HUVECs than in untreated controls. Pretreatment with AG, L-N(6)-(1-iminoethyl) lysine hydrochloride (a selective inhibitor of iNOS), and L-NA attenuated nitrosative stress. While a selective target of radiation-induced vascular endothelial damage was not definitely determined, these results suggest that NO generated from iNOS could contribute to vasorelaxation. These studies highlight a potential role of iNOS inhibitors in ameliorating radiation-induced vascular endothelial damage. PMID:23704776

  17. Functional Inducible Nitric Oxide Synthase Gene Variants Associate With Hypertension

    PubMed Central

    Nikkari, Seppo T.; Määttä, Kirsi M.; Kunnas, Tarja A.

    2015-01-01

    Abstract Increased inducible nitric oxide synthase (iNOS) activity and expression has been associated with hypertension, but less is known whether the 2 known functional polymorphic sites in the iNOS gene (g.–1026 C/A (rs2779249), g.2087 G/A (rs2297518)) affect susceptibility to hypertension. The objective of this study was to investigate the association between the genetic variants of iNOS and diagnosed hypertension in a Finnish cohort. This study included 320 hypertensive cases and 439 healthy controls. All participants were 50-year-old men and women and the data were collected from the Tampere adult population cardiovascular risk study (TAMRISK). DNA was extracted from buccal swabs and iNOS single nucleotide polymorphisms (SNPs) were analyzed using KASP genotyping PCR. Data analysis was done by logistic regression. At the age of 50 years, the SNP rs2779249 (C/A) associated significantly with hypertension (P = 0.009); specifically, subjects carrying the A-allele had higher risk of hypertension compared to those carrying the CC genotype (OR = 1.47; CI = 1.08–2.01; P = 0.015). In addition, a 15-year follow-up period (35, 40, and 45 years) of the same individuals showed that carriers of the A-allele had more often hypertension in all of the studied age-groups. The highest risk for developing hypertension was obtained among 35-year-old subjects (odds ratio [OR] 3.83; confidence interval [CI] = 1.20–12.27; P = 0.024). Those carrying variant A had also significantly higher readings of both systolic (P = 0.047) and diastolic (P = 0.048) blood pressure during the follow-up. No significant associations between rs2297518 (G/A) variants alone and hypertension were found. However, haplotype analysis of rs2779249 and rs2297518 revealed that individuals having haplotype H3 which combines both A alleles (CA–GA, 19.7% of individuals) was more commonly found in the hypertensive group than in the normotensive group (OR = 2.01; CI = 1

  18. Inducible nitric-oxide synthase attenuates vasopressin-dependent Ca2+ signaling in rat hepatocytes.

    PubMed

    Patel, Sandip; Gaspers, Lawrence D; Boucherie, Sylviane; Memin, Elisabeth; Stellato, Kerri Anne; Guillon, Gilles; Combettes, Laurent; Thomas, Andrew P

    2002-09-13

    Increases in both Ca(2+) and nitric oxide levels are vital for a variety of cellular processes; however, the interaction between these two crucial messengers is not fully understood. Here, we demonstrate that expression of inducible nitric-oxide synthase in hepatocytes, in response to inflammatory mediators, dramatically attenuates Ca(2+) signaling by the inositol 1,4,5-trisphosphate-forming hormone, vasopressin. The inhibitory effects of induction were reversed by nitric oxide inhibitors and mimicked by prolonged cyclic GMP elevation. Induction was without effect on Ca(2+) signals in response to AlF(4)(-) or inositol 1,4,5-trisphosphate, indicating that phospholipase C activation and release of Ca(2+) from inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores were not targets for nitric oxide inhibition. Vasopressin receptor levels, however, were dramatically reduced in induced cultures. Our data provide a possible mechanism for hepatocyte dysfunction during chronic inflammation. PMID:12097323

  19. The role of nitric oxide on DNA damage induced by benzene metabolites

    PubMed Central

    MELIKIAN, ASSIEH A.; CHEN, KUN-MING; LI, HEYI; SODUM, RAMA; FIALA, EMERICH; EL-BAYOUMY, KARAM

    2013-01-01

    Benzene, a tobacco constituent, is a leukemogen in humans and a carcinogen in rodents. Several benzene metabolites generate superoxide anion (O2•−) and induce nitric oxide synthase in the bone marrow of mice. We hypothesized that the reaction of nitric oxide (•NO) with O2•− leads to the formation of peroxynitrite as an intermediate during benzene metabolism. This hypothesis was supported by demonstrating that the exposure of mice to benzene produced nitrated metabolites and enhanced the levels of protein-bound 3-nitrotyrosine in the bone marrow of mice in vivo. In the current study, we investigated the influence of nitric oxide, generated from sodium 1-(N,N-diethylamino)diazen-1-ium-1,2-diolate, on DNA strand breaks induced by each single or binary benzene metabolite at different doses and compared the levels of the DNA damage induced by each benzene metabolite in the presence of nitric oxide with the levels of DNA strand breaks induced by peroxynitrite at similar doses in vitro. We found that among benzene metabolites only 1,2,4-trihydroxybenzene (BT) can induce significant DNA damage in the absence of nitric oxide. While 1,4-dihydroxybenzene (HQ), 1,4-benzo-quinone (BQ) and 1,2-dihydroxybenzene (CAT) require •NO to induce DNA strand breaks, hydroquinone was the most potent DNA-damaging benzene metabolite in the presence of •NO. The order of DNA breaks by benzene metabolites in the presence of •NO is: Peroxynitrite = HQ > BT > BQ > CAT. The •NO and O2•− scavengers inhibited DNA damage induced by [HQ+•NO]. Benzene, trans,trans-muconaldehyde, and phenol, do not induce DNA strand breaks either in the absence or presence of •NO. However, adding phenol to [HQ+•NO] leads to greater DNA damage than [HQ+•NO] alone. Collectively, these results suggest that nitric oxide is an important factor in DNA damage induced by certain benzene metabolites, probably via the formation of the peroxynitrite intermediate. Phenol, the major benzene metabolite

  20. (-)-Epicatechin-induced recovery of mitochondria from simulated diabetes: Potential role of endothelial nitric oxide synthase.

    PubMed

    Ramírez-Sánchez, Israel; Rodríguez, Alonso; Moreno-Ulloa, Aldo; Ceballos, Guillermo; Villarreal, Francisco

    2016-05-01

    (-)-Epicatechin increases indicators associated with mitochondrial biogenesis in endothelial cells and myocardium. We investigated endothelial nitric oxide synthase involvement on (-)-epicatechin-induced increases in indicators associated with mitochondrial biogenesis in human coronary artery endothelial cells cultured in normal-glucose and high-glucose media, as well as to restore indicators of cardiac mitochondria from the effects of simulated diabetes. Here, we demonstrate the role of endothelial nitric oxide synthase on (-)-epicatechin-induced increases in mitochondrial proteins, transcription factors and sirtuin 1 under normal-glucose conditions. In simulated diabetes endothelial nitric oxide synthase function, mitochondrial function-associated and biogenesis-associated indicators were adversely impacted by high glucose, effects that were reverted by (-)-epicatechin. As an animal model of type 2 diabetes, 2-month old C57BL/6 mice were fed a high-fat diet for 16 weeks. Fasting and fed blood glucose levels were increased and NO plasma levels decreased. High-fat-diet-fed mice myocardium revealed endothelial nitric oxide synthase dysfunction, reduced mitochondrial activity and markers of mitochondrial biogenesis. The administration of 1 mg/kg (-)-epicatechin for 15 days by oral gavage shifted these endpoints towards control mice values. Results suggest that endothelial nitric oxide synthase mediates (-)-epicatechin-induced increases of indicators associated with mitochondrial biogenesis in endothelial cells. (-)-Epicatechin also counteracts the negative effects that high glucose or simulated type 2 diabetes has on endothelial nitric oxide synthase function. PMID:26993496

  1. Neostigmine-induced contraction and nitric oxide-induced relaxation of isolated ileum from STZ diabetic guinea pigs

    PubMed Central

    Cellini, Joseph; Jukic, Anne Marie Zaura; LePard, Kathy J.

    2011-01-01

    Both delayed gastrointestinal transit and autonomic neuropathy have been documented in patients with diabetes mellitus. The mechanism of neostigmine, an agent that mimics release of acetylcholine from autonomic neurons by prokinetic agents, to contract smooth muscle, despite dysfunctional enteric neural pathways, was determined using isolated ilea from STZ-treated and control guinea pigs. Both bethanechol- and neostigmine-induced contractions were stronger in diabetic ileum. Bethanechol-induced contractions of control but not diabetic ileum were increased by low dose scopolamine suggesting reduced activation of presynaptic muscarinic autoreceptors in diabetic ileum. The muscarinic receptor antagonist 4-DAMP strongly, but the nicotinic receptor antagonist hexamethonium only weakly, reduced neostigmine-induced contractions of control and diabetic ilea. The amount of acetylcholine, inferred from tissue choline content, was increased in diabetic ileum. Nicotinic neural and noncholinergic postjunctional smooth muscle receptors contributed more strongly to neostigmine-induced contractions in diabetic than control ileum. Relaxation of diabetic ileum by exogenous nitric oxide generated from sodium nitroprusside was comparable to control ileum, but smooth muscle relaxation by L-arginine using neuronal nitric oxide synthase to generate nitric oxide was weaker in diabetic ileum with evidence for a role for inducible nitric oxide synthase. Despite autonomic neuropathy, neostigmine strongly contracted ileum from diabetic animals but by a different mechanism including stronger activation of postjunctional muscarinic receptors, greater synaptic acetylcholine, stronger activation of noncholinergic excitatory pathways, and weaker activation of inhibitory pathways. A selective medication targeting a specific neural pathway may more effectively treat disordered gastrointestinal transit in patients with diabetes mellitus. PMID:21880552

  2. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    SciTech Connect

    Sharma, Bhupesh Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in

  3. L-arginine inhibits isoproterenol-induced cardiac hypertrophy through nitric oxide and polyamine pathways.

    PubMed

    Lin, Yan; Wang, Li-Na; Xi, Yu-Hui; Li, Hong-Zhu; Xiao, Feng-Gang; Zhao, Ya-Jun; Tian, Ye; Yang, Bao-Feng; Xu, Chang-Qing

    2008-08-01

    Polyamines (putrescine, spermidine and spermine) are essential for cell growth and differentiation. Nitric oxide exhibits antihypertrophic functions and inhibits cardiac remodelling. However, the metabolism of polyamines and the potential interactions with nitric oxide in cardiac hypertrophy remain unclear. We randomly divided Wistar rats into four treatment groups: controls, isoproterenol (ISO), ISO and L-arginine, and L-arginine. Isoproterenol (5 mg/kg/day, subcutaneously) and/or L-arginine (800 mg/kg/day, intraperitoneally) was administered once daily for 7 days. The expression of atrial natriuretic peptide mRNA was determined by reverse transcription-polymerase chain reaction, and fibrogenesis of heart was assessed by Van Gieson staining. Polyamines were measured with high-performance liquid chromatography, and plasma nitric oxide content and lactate dehydrogenase (LDH) activity were determined with a spectrophotometer. The expression levels of ornithine decarboxylase, spermidine/spermine N1-acetyltransferase (SSAT), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) were analysed by Western blot. Heart-to-body weight ratio, left ventricle-to-body weight ratio, atrial natriuretic peptide mRNA expression, collagen fibres and LDH activity were elevated, both ornithine decarboxylase and SSAT proteins were up-regulated, and total polyamines were increased in the group treated with ISO. Additionally, the expression of iNOS was up-regulated, eNOS was down-regulated, and nitric oxide levels were low. Notably, cotreatment with L-arginine reversed most of these changes except for SSAT expression,which was further up-regulated. We propose that increased polyamines and decreased nitric oxide are involved in cardiac hypertrophy induced by ISO and suggest that L-arginine pre-treatment can attenuate cardiac hypertrophy through the regulation of key enzymes of the polyamine and nitric oxide pathways. PMID:18816294

  4. Energetic particle-induced enhancements of stratospheric nitric acid

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1994-01-01

    Inclusion of complete ion chemistry in the calculation of minor species production during energetic particle deposition events leads to significant enhancement in the calculated nitric acid concentration during precipitation. An ionization rate of 1.2 x 10(exp 3)/cu cm/s imposed for 1 day increases HNO3 from 3 x 10(exp 5) to 6 x 10(exp 7)/cu cm at 50 km. With an ionization rate of 600 cu cm/s, the maximum HNO3 is 3 x 10(exp 7)/cu cm. Calculations which neglect negative ions predict the nitric acid will fall during precipitation events. The decay time for converting HNO3 into odd nitrogen and hydrogen is more than 1 day for equinoctial periods at 70 deg latitude. Examination of nitric acid data should yield important information on the magnitude and frequency of charged particle events.

  5. Inhibition of lipopolysaccharide-induced inducible nitric oxide synthase and cyclooxygenase-2 expression by xanthanolides isolated from Xanthium strumarium.

    PubMed

    Yoon, Jeong Hoon; Lim, Hyo Jin; Lee, Hwa Jin; Kim, Hee-Doo; Jeon, Raok; Ryu, Jae-Ha

    2008-03-15

    Three sesquiterpenoids, xanthatin (1), xanthinosin (2), and 4-oxo-bedfordia acid (3) were isolated from Xanthium strumarium as inhibitors of nitric oxide synthesis in activated microglia (IC(50) values: 0.47, 11.2, 136.5 microM, respectively). Compounds 1 and 2 suppressed the expression of iNOS and COX-2 and the activity of NF-kappaB through the inhibition of LPS-induced I-kappaB-alpha degradation in microglia. PMID:18276135

  6. Nitric oxide-induced p53 accumulation and regulation of inducible nitric oxide synthase expression by wild-type p53.

    PubMed Central

    Forrester, K; Ambs, S; Lupold, S E; Kapust, R B; Spillare, E A; Weinberg, W C; Felley-Bosco, E; Wang, X W; Geller, D A; Tzeng, E; Billiar, T R; Harris, C C

    1996-01-01

    The tumor suppressor gene product p53 plays an important role in the cellular response to DNA damage from exogenous chemical and physical mutagens. Therefore, we hypothesized that p53 performs a similar role in response to putative endogenous mutagens, such as nitric oxide (NO). We report here that exposure of human cells to NO generated from an NO donor or from overexpression of inducible nitric oxide synthase (NOS2) results in p53 protein accumulation. In addition, expression of wild-type (WT) p53 in a variety of human tumor cell lines, as well as murine fibroblasts, results in down-regulation of NOS2 expression through inhibition of the NOS2 promoter. These data are consistent with the hypothesis of a negative feedback loop in which endogenous NO-induced DNA damage results in WT p53 accumulation and provides a novel mechanism by which p53 safeguards against DNA damage through p53-mediated transrepression of NOS2 gene expression, thus reducing the potential for NO-induced DNA damage. Images Fig. 1 Fig. 2 Fig. 3 PMID:8637893

  7. Nitric oxide mediates glial-induced neurodegeneration in Alexander disease

    PubMed Central

    Wang, Liqun; Hagemann, Tracy L.; Kalwa, Hermann; Michel, Thomas; Messing, Albee; Feany, Mel B.

    2015-01-01

    Glia play critical roles in maintaining the structure and function of the nervous system; however, the specific contribution that astroglia make to neurodegeneration in human disease states remains largely undefined. Here we use Alexander disease, a serious degenerative neurological disorder caused by astrocyte dysfunction, to identify glial-derived NO as a signalling molecule triggering astrocyte-mediated neuronal degeneration. We further find that NO acts through cGMP signalling in neurons to promote cell death. Glial cells themselves also degenerate, via the DNA damage response and p53. Our findings thus define a specific mechanism for glial-induced non-cell autonomous neuronal cell death, and identify a potential therapeutic target for reducing cellular toxicity in Alexander disease, and possibly other neurodegenerative disorders with glial dysfunction. PMID:26608817

  8. Nitric oxide mediates glial-induced neurodegeneration in Alexander disease.

    PubMed

    Wang, Liqun; Hagemann, Tracy L; Kalwa, Hermann; Michel, Thomas; Messing, Albee; Feany, Mel B

    2015-01-01

    Glia play critical roles in maintaining the structure and function of the nervous system; however, the specific contribution that astroglia make to neurodegeneration in human disease states remains largely undefined. Here we use Alexander disease, a serious degenerative neurological disorder caused by astrocyte dysfunction, to identify glial-derived NO as a signalling molecule triggering astrocyte-mediated neuronal degeneration. We further find that NO acts through cGMP signalling in neurons to promote cell death. Glial cells themselves also degenerate, via the DNA damage response and p53. Our findings thus define a specific mechanism for glial-induced non-cell autonomous neuronal cell death, and identify a potential therapeutic target for reducing cellular toxicity in Alexander disease, and possibly other neurodegenerative disorders with glial dysfunction. PMID:26608817

  9. Nitric oxide induces apoptosis in a human colonic epithelial cell line, T84

    PubMed Central

    Sandoval, M.; Liu, X.; Oliver, P. D.; Zhang, X.-J.; Clark, D. A.

    1995-01-01

    Chronic inflammation is associated with inducible nitric oxide synthase expression in infiltrating and resident cells (epithelia, neurons) and an exaggerated release of nitric oxide. NO can induce apoptosis in macrophages and tumour cell lines. We investigated whether NO induced cell death in an epithelial (T84) cell fine via apoptosis. Culture T84 cells were exposed to a bolus of NO (40 or 80 μM) dissolved in Hank's balanced salt solution (HBSS) supplemented with 10% fetal calf serum (FCS). After incubation for 4 h at 37°C in 5% CO2, cells were either stained for DNA fragmentation with the TdT-mediated dUTP–biotin nick end labelling (TUNEL) method, or cytosolic DNA fragments quantified by a cell death detection ELISA assay. Nitric oxide induced apoptosis in a dose-dependent manner which preceded frank cell death (failure to exclude Trypan blue). These data suggest that epithelial cell death may be NO dependent and via apoptosis, in states of gut inflammation. PMID:18475646

  10. The flavonoid luteolin induces nitric oxide production and arterial relaxation

    PubMed Central

    Si, Hongwei; Wyeth, Richard P.; Liu, Dongmin

    2013-01-01

    Purpose Luteolin, a flavone present in many foods and medicinal plants, may have beneficial effects on various human chronic diseases. In the present study, we investigated the hypothesis that luteolin can directly act on vascular endothelial cells (ECs), leading to nitric oxide (NO) production and subsequent vascular relaxation. Methods Rat aortic rings were mounted in organ bath. Luteolin was added cumulatively and vessel relaxation of rat aortic rings precontracted with phenylephrine (PE) or potassium was recorded. Endothelial nitric oxide synthase (eNOS) phosphorylation at Ser1177 and NO production from aortic rings and primary human aortic endothelial cells (HAECs) exposed to luteolin were measured by using Western blot and fluorometric assay, respectively. Results Luteolin dose-dependently (10-100 μmol/L) elicited relaxation of PE- or potassium-contracted aortic rings. The vasorelaxation effect of luteolin was attenuated by the eNOS inhibitor, N-nitro-L-arginine methyl ester, suggesting that this luteolin action is at least partially mediated by activating eNOS activity. We further found that luteolin dose-dependently (10-100 μmol/L) increased eNOS phosphorylation at Ser1177 (up to 1.9 fold) in isolated rat rings. Consistently, exposure of HAECs to luteolin also increased eNOS phosphorylation and NO production. Conclusion Luteolin may be a vascular protective agent by directly acting on vascular ECs to stimulate NO-dependent vascular dilatation. PMID:23604495

  11. The Endogenous Nitric Oxide Mediates Selenium-Induced Phytotoxicity by Promoting ROS Generation in Brassica rapa

    PubMed Central

    Hu, Liang-Bin; Li, You-Qin; Chen, Jian; Yang, Li-Fei

    2014-01-01

    Selenium (Se) is suggested as an emerging pollutant in agricultural environment because of the increasing anthropogenic release of Se, which in turn results in phytotoxicity. The most common consequence of Se-induced toxicity in plants is oxidative injury, but how Se induces reactive oxygen species (ROS) burst remains unclear. In this work, histofluorescent staining was applied to monitor the dynamics of ROS and nitric oxide (NO) in the root of Brassica rapa under Se(IV) stress. Se(IV)-induced faster accumulation of NO than ROS. Both NO and ROS accumulation were positively correlated with Se(IV)-induced inhibition of root growth. The NO accumulation was nitrate reductase (NR)- and nitric oxide synthase (NOS)-dependent while ROS accumulation was NADPH oxidase-dependent. The removal of NO by NR inhibitor, NOS inhibitor, and NO scavenger could alleviate Se(IV)-induced expression of Br_Rbohs coding for NADPH oxidase and the following ROS accumulation in roots, which further resulted in the amelioration of Se(IV)-induced oxidative injury and growth inhibition. Thus, we proposed that the endogenous NO played a toxic role in B. rapa under Se(IV) stress by triggering ROS burst. Such findings can be used to evaluate the toxic effects of Se contamination on crop plants. PMID:25333984

  12. Suppression of inducible nitric oxide synthase pathway by 7-deacetylgedunin, a limonoid from Xylocarpus sp.

    PubMed

    Sarigaputi, Chanin; Sangpech, Nuanpan; Palaga, Tanapat; Pudhom, Khanitha

    2015-03-01

    In this study, limonoids isolated from Xylocarpus plants were tested for their in vitro anti-inflammatory effects. The results demonstrated that only 7-deacetylgedunin (1), a gedunin-type limonoid, significantly inhibited lipopolysaccharide- and interferon-γ-stimulated production of nitric oxide in murine macrophage RAW 264.7 cells. The suppression of nitric oxide production by 1 was correlated with the downregulation of mRNA and protein expression of inducible nitric oxide synthase. Mechanistic studies revealed that the transcriptional activity of nuclear factor-κB, IκBα degradation, and the activation of mitogen-activated protein kinases, stimulated with lipopolysaccharide and interferon-γ, were suppressed by 1. PMID:25714725

  13. Regulation of Injury-Induced Neurogenesis by Nitric Oxide

    PubMed Central

    Carreira, Bruno P.; Carvalho, Caetana M.; Araújo, Inês M.

    2012-01-01

    The finding that neural stem cells (NSCs) are able to divide, migrate, and differentiate into several cellular types in the adult brain raised a new hope for restorative neurology. Nitric oxide (NO), a pleiotropic signaling molecule in the central nervous system (CNS), has been described to be able to modulate neurogenesis, acting as a pro- or antineurogenic agent. Some authors suggest that NO is a physiological inhibitor of neurogenesis, while others described NO to favor neurogenesis, particularly under inflammatory conditions. Thus, targeting the NO system may be a powerful strategy to control the formation of new neurons. However, the exact mechanisms by which NO regulates neural proliferation and differentiation are not yet completely clarified. In this paper we will discuss the potential interest of the modulation of the NO system for the treatment of neurodegenerative diseases or other pathological conditions that may affect the CNS. PMID:22997523

  14. Lipopolysaccharide induces nitric oxide synthase expression and platelet-activating factor increases nitric oxide production in human fetal membranes in culture

    PubMed Central

    Seyffarth, Gunter; Nelson, Paul N; Dunmore, Simon J; Rodrigo, Nalinda; Murphy, Damian J; Carson, Ray J

    2004-01-01

    Background Platelet-activating factor and nitric oxide may be involved in the initiation of human labour as inflammatory mediators. The aim of this study was to test whether platelet-activating factor and lipopolysaccharide were able to induce nitric oxide synthase expression and stimulate the production of nitric oxide in human fetal membrane explants in culture. Methods Fetal membranes were collected from Caesarean sections at term. RNA was extracted from membranes and subjected to a qualitative RT-PCR to assess the baseline expression of iNOS. Discs of fetal membranes were cultured for 24 hours in the presence of platelet-activating factor at a dose range of 0.1 nanomolar – 1 micomolar or 1 microgram/ml lipopolysaccharide. Nitric oxide production was measured via nitrite ions in the culture medium and mRNA for iNOS was detected by RT-PCR. Results Culturing the membrane discs in medium containing serum induced nitric oxide synthase expression and platelet-activating factor significantly stimulated the production of nitric oxide under these conditions. When cultured without serum inducible nitric oxide synthase expression was induced by lipopolysaccharide, but not by platelet-activating factor. Conclusion Platelet-activating factor may have a role in the initiation of labour, at term or preterm, via the increased local production of nitric oxide as an inflammatory mediator. In this model of intrauterine infection, lipopolysaccharide was found to induce iNOS expression by fetal membranes, and this mechanism could be involved in preterm labour. PMID:15191613

  15. Extract of Meretrix meretrix Linnaeus induces angiogenesis in vitro and activates endothelial nitric oxide synthase

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Wei, Jianteng; Wang, Hui; Ding, Lili; Zhang, Yuyan; Lin, Xiukun

    2012-09-01

    Meretrix meretrix Linnaeus has long been used as traditional Chinese medicine in oriental medicine. The angiogentic activity of the extract of M. meretrix was investigated in this study, using human umbilical vein endothelial cells (HUVECs). Extract of M. meretrix Linnaeus (AFG-25) was prepared with acetone and ethanol precipitation, and further separated by Sephadex G-25 column. The results show that AFG-25 promoted proliferation, migration, and capillary-like tube formation in HUVECs, and in the presence of eNOS inhibitor NMA, the tube formation induced by AFG-25 is inhibited significantly. Moreover, AFG-25 could also promote the activation of endothelial nitric oxide synthase (eNOS) and the resultant elevation of nitric oxide (NO) production. The results suggested that M. meretrix contains active ingredients with angiogentic activity and eNOS/NO signal pathway is in part involved in the proangiogenesis effect induced by AFG-25.

  16. Pentylentetrazole-induced loss of blood-brain barrier integrity involves excess nitric oxide generation by neuronal nitric oxide synthase.

    PubMed

    Danjo, Sonoko; Ishihara, Yasuhiro; Watanabe, Masatomo; Nakamura, Yu; Itoh, Kouichi

    2013-09-12

    Dysfunction of the blood-brain barrier (BBB) is one of the major pathophysiological consequences of epilepsy. The increase in the permeability caused by BBB failure is thought to contribute to the development of epileptic outcomes. We developed a method by which the BBB permeability can be demonstrated by gadolinium-enhanced T1 weighted imaging (GdET1WI). The present study examined the changes in the BBB permeability in mice with generalized convulsive seizures (GCS) induced by acute pentylentetrazole (PTZ) injection. At 15min after PTZ-induced GCS, the BBB temporarily leaks BBB-impermeable contrast agent into the parenchyma of the diencephalon, hippocampus and cerebral cortex in mice, and the loss of BBB integrity was gradually recovered by 24h. The temporary BBB failure is a critical link to the glutamatergic activities that occur following the injection of PTZ. PTZ activates the glutamatergic pathway via the NMDA receptor, then nitric oxide (NO) is generated by NMDA receptor-coupled neuronal NO synthase (nNOS). To examine the influence of nNOS-derived NO induced by PTZ on the increases of the BBB permeability, GdET1WI was performed using conventional nNOS gene-deficient mice with or without PTZ injection. The failure of the BBB induced by PTZ was completely protected by nNOS deficiency in the brain. These results suggest that nNOS-derived excess NO in the glutamatergic pathway plays a key role in the failure of the BBB during PTZ-induced GCS. The levels of NO synthetized by nNOS in the brain may represent an important target for the future development of drugs to protect the BBB. PMID:23831997

  17. Involvement of nitric oxide pathway in the PAF-induced relaxation of rat thoracic aorta.

    PubMed Central

    Moritoki, H.; Hisayama, T.; Takeuchi, S.; Miyano, H.; Kondoh, W.

    1992-01-01

    1. The mechanism of the vasorelaxant effect of platelet activating factor (PAF) on rat thoracic aorta and the effect of aging on the PAF-induced relaxation were investigated. 2. PAF at concentrations causing relaxation induced marked increases in guanosine 3':5'-cyclic monophosphate (cyclic GMP) production, but did not induce an increase in adenosine 3':5'-cyclic monophosphate (cyclic AMP). 3. Removal of the endothelium by mechanical rubbing, and treatment with the PAF antagonists CV-3988, CV-6209 and FR-900452, the nitric oxide biosynthesis inhibitor, NG-nitro L-arginine, the radical scavenger, haemoglobin, and the soluble guanylate cyclase inhibitor, methylene blue, inhibited PAF-induced relaxation and abolished or attenuated PAF-stimulated cyclic GMP production. 4. The relaxation was greatest in arteries from rats aged 4 weeks. With an increase in age, the response of the arteries to PAF was attenuated. 5. Endothelium-dependent cyclic GMP production also decreased with increase in age of the rats. 6. These results suggest that PAF stimulates production of nitric oxide from L-arginine by acting on the PAF receptors in the endothelium, which in turn stimulates soluble guanylate cyclase in the smooth muscle cells, and so increases production of cyclic GMP, thus relaxing the arteries. Age-associated decrease in PAF-induced relaxation may result from a reduction of cyclic GMP formation. PMID:1358382

  18. In vivo expression of monokine and inducible nitric oxide synthase in experimentally induced pulmonary granulomatous inflammation. Evidence for sequential production of interleukin-1, inducible nitric oxide synthase, and tumor necrosis factor.

    PubMed Central

    Tsuji, M.; Dimov, V. B.; Yoshida, T.

    1995-01-01

    The present study examined the temporal pattern and localization of interleukin-1, tumor necrosis factor-alpha, and inducible nitric oxide synthase expression in lung tissue undergoing foreign body granuloma formation. Pulmonary granulomas were induced by the intratracheal injection of dextran beads into genetically high granuloma responder, carrying Bcgs (BALB/c), and low responder, carrying Bcgr (C3H/HeJ and DBA/2), mice. There was a pattern of sequential expression of these molecules in BALB/c mice. Thus, interleukin-1 alpha and inducible nitric oxide synthase were induced mostly in the cells accumulated around the beads and also in some bronchiolar epithelial cells during the early phase (1 to 3 days), whereas tumor necrosis factor-alpha was induced in the cells around the beads at the later resolution phase (3 to 7 days). By contrast, in low responder mice, an increase in the expression of interleukin-1 alpha and inducible nitric oxide synthase was detected in lung macrophages as well as in alveolar cells and bronchiolar epithelial cells on day 1, but that of tumor necrosis factor-alpha was not detected throughout the period. These results together with our previous findings on cytokine activity in granuloma extract suggest that interleukin-1 and nitric oxide produced by recruited macrophages may take part in the early, macrophage-dependent phase of granuloma formation whereas tumor necrosis factor-alpha may be more crucial as a mediator responsible for the difference in innate resistance or susceptibility to granuloma formation. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:7573346

  19. Auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism

    NASA Astrophysics Data System (ADS)

    Cai, Weiming; Hu, Liwei; Hu, Xiangyang; Cui, Dayong; Cai, Weiming

    Gravitropism is the asymmetric growth or curvature of plant organs in response to gravistimulation. There is a complex signal transduction cascade which involved in the differential growth of plants in response to changes in the gravity vector. The role of auxin in gravitropism has been demonstrated by many experiments, but little is known regarding the molecular details of such effects. In our studies before, mediation of the gravitropic bending of soybean roots and rice leaf sheath bases by nitric oxide, cGMP and gibberellins, are induced by auxin. The asymmetrical distribution of nitric oxide, cGMP and gibberellins resulted from the asymmetrical synthesis of them in bending sites. In soybean roots, inhibitions of NO and cGMP synthesis reduced differential NO and cGMP accumulation respectively, which both of these effects can lead to the reduction of gravitropic bending. Gibberellin-induced OsXET, OsEXPA4 and OsRWC3 were also found involved in the gravitropic bending. These data indicated that auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism. More experiments need to prove the more detailed mechanism of them.

  20. Treatment of sunitinib-induced hypertension in solid tumor by nitric oxide donors.

    PubMed

    León-Mateos, L; Mosquera, J; Antón Aparicio, L

    2015-12-01

    Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are overexpressed in the majority of renal cell carcinomas. This characteristic has supported the rationale of targeting VEGF-driven tumour vascularization, especially in clear cell RCC. VEGF-inhibiting strategies include the use of tyrosine kinase inhibitors (sunitinib, axitinib, pazopanib, and sorafenib) and neutralizing antibodies such as bevacizumab. Hypertension (HTN) is one of the most common adverse effects of angiogenesis inhibitors. HTN observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of HTN. Although the exact mechanism by tyrosine kinase inhibitors induce HTN has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS) and nitric oxide (NO) production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction) occurs upon VEGF signaling inhibition. NO donors could be successfully used not only for the treatment of developed angiogenesis-inhibitor-induced hypertension but also for preventive effects. PMID:26386874

  1. Behavioral impairments and changes of nitric oxide and inducible nitric oxide synthase in the brains of molarless KM mice.

    PubMed

    Pang, Qian; Hu, Xingxue; Li, Xinya; Zhang, Jianjun; Jiang, Qingsong

    2015-02-01

    More studies showed that as a common disorder in senior population, loss of teeth could adversely affect human cognitive function, and nitric oxide (NO) might play an important role in the cognitive function. However, the underlying mechanism has not yet been well-established. The objectives of this study are to evaluate behavior changes of KM mice after loss of molars, and levels of NO and inducible nitric oxide synthase (iNOS) in the brain in molarless condition. It is hypothesized that loss of molars of the mice tested results in the cognitive impairments and that the process is mediated by NO in the brain through the signaling pathways. Morris water maze is used to test the behavioral changes after 8 weeks of the surgery. The changes of NO and iNOS are evaluated by using Griess assay, western blot, and immunohistochemistry method. The results show that 8 weeks after loss of molars, the spatial learning and memory of KM mice impair and the levels of NO and iNOS in mice hippocampus increase. These findings suggest that molar extraction is associated with the behavioral impairment, and that the changes of NO and iNOS in the hippocampus may be involved in the behavioral changes in the molarless condition. PMID:25447296

  2. Traumatic Brain Injury Disrupts Cerebrovascular Tone Through Endothelial Inducible Nitric Oxide Synthase Expression and Nitric Oxide Gain of Function

    PubMed Central

    Villalba, Nuria; Sonkusare, Swapnil K.; Longden, Thomas A.; Tran, Tram L.; Sackheim, Adrian M.; Nelson, Mark T.; Wellman, George C.; Freeman, Kalev

    2014-01-01

    Background Traumatic brain injury (TBI) has been reported to increase the concentration of nitric oxide (NO) in the brain and can lead to loss of cerebrovascular tone; however, the sources, amounts, and consequences of excess NO on the cerebral vasculature are unknown. Our objective was to elucidate the mechanism of decreased cerebral artery tone after TBI. Methods and Results Cerebral arteries were isolated from rats 24 hours after moderate fluid‐percussion TBI. Pressure‐induced increases in vasoconstriction (myogenic tone) and smooth muscle Ca2+ were severely blunted in cerebral arteries after TBI. However, myogenic tone and smooth muscle Ca2+ were restored by inhibition of NO synthesis or endothelium removal, suggesting that TBI increased endothelial NO levels. Live native cell NO, indexed by 4,5‐diaminofluorescein (DAF‐2 DA) fluorescence, was increased in endothelium and smooth muscle of cerebral arteries after TBI. Clamped concentrations of 20 to 30 nmol/L NO were required to simulate the loss of myogenic tone and increased (DAF‐2T) fluorescence observed following TBI. In comparison, basal NO in control arteries was estimated as 0.4 nmol/L. Consistent with TBI causing enhanced NO‐mediated vasodilation, inhibitors of guanylyl cyclase, protein kinase G, and large‐conductance Ca2+‐activated potassium (BK) channel restored function of arteries from animals with TBI. Expression of the inducible isoform of NO synthase was upregulated in cerebral arteries isolated from animals with TBI, and the inducible isoform of NO synthase inhibitor 1400W restored myogenic responses following TBI. Conclusions The mechanism of profound cerebral artery vasodilation after TBI is a gain of function in vascular NO production by 60‐fold over controls, resulting from upregulation of the inducible isoform of NO synthase in the endothelium. PMID:25527626

  3. Armeniacae semen extract suppresses lipopolysaccharide-induced expressions of cyclooxygenase [correction of cycloosygenase]-2 and inducible nitric oxide synthase in mouse BV2 microglial cells.

    PubMed

    Chang, Hyun-Kyung; Yang, Hye-Young; Lee, Taeck-Hyun; Shin, Min-Chul; Lee, Myoung-Hwa; Shin, Mal-Soon; Kim, Chang-Ju; Kim, Ok-Jin; Hong, Seon-Pyo; Cho, Sonhae

    2005-03-01

    Armeniacae semen is the seed of Prunus armeniaca L. var. ansu MAXIM which is classified into Rosaceae. In traditional oriental medicine, Armeniacae semen has been used for the treatment of pain and inflammatory diseases. In this study, the effect of Armeniacae semen extract on lipopolysaccharide-induced inflammation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, prostaglandin E2 immunoassay, and nitric oxide detection on mouse BV2 microglial cells. In the present results, Armeniacae semen extract suppressed prostaglandin E2 synthesis and nitric oxide production by inhibiting the lipopolysaccharide-stimulated enhancement of cyclooxygenase-2 and inducible nitric oxide synthase mRNA expression in BV2 cells. These results show that Armeniacae semen exerts anti-inflammatory and analgesic effects probably by suppression of cyclooxygenase-2 and inducible nitric oxide synthase expressions. PMID:15744067

  4. Chitosan and blueberry treatment induces arginase activity and inhibits nitric oxide production during acetaminophen-induced hepatotoxicity

    PubMed Central

    Ozcelik, Eda; Uslu, Sema; Burukoglu, Dilek; Musmul, Ahmet

    2014-01-01

    Background: Liver diseases have become a major problem of the worldwide. More than 50% of all cases of liver failure can be attributed to drugs. Among these, acetaminophen is the most common cause. Objective: The aim of this study was to investigate the the hepatoprotective effects of blueberry and chitosan on tissue arginase activity, ornithine and nitric oxide levels during the acetaminophen-induced hepatotoxicity. Materials and Methods: Acetaminophen (250 mg/kg body weight per day), blueberry (60 mg/kg body weight per day) and, chitosan (200 mg/kg body weight per day) were administered to the rats by oral gavage during the experimental period. Results: Blueberry and chitosan significantly decreased liver arginase activity and ornithine levelsand and increased nitric oxide levels. Glutathione levels were remarkably increased by chitosan and blueberry treatments. Conclusion: The results of the present study indicate that blueberry and chitosan effectively protected against the acetaminophen-induced hepatotoxicity. The hepatoprotective effect afforded by blueberry and chitosan can be attributed to its antioxidant and anti-inflammatory activities. PMID:24991095

  5. Nitric oxide: Mediator of nonadrenergic noncholinergic nerve-induced responses of opossum esophageal muscle

    SciTech Connect

    Murray, J.; Du, C.; Conklin, J.L.; Ledlow, A.; Bates, J.N. )

    1991-03-15

    Nonadrenergic noncholinergic (NANC) nerves of the opossum esophagus mediate relaxation of circular muscle from the lower esophageal sphincter (LES) and the off contraction of circular esophageal muscle. The latencies between the end of the stimulus and the off contraction describe a gradient such that the latency is longest in muscle from the caudad esophagus. N{sup G}-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthase, and nitric oxide were used to test the hypothesis that NO is a mediator of these nerve-induced responses. Both electrical field stimulation (EFS) of intrinsic esophageal nerves and exogenous NO relaxed LES muscle. Only EFS-induced relaxation was inhibited by L-NNA. L-arginine, the substrate for NO synthase, antagonized the inhibitory effect of L-NNA. Exogenous NO neither relaxed nor contracted circular esophageal muscle. Both the amplitude and the latency of the off contraction were diminished by L-NNA. L-arginine antagonized the action of L-NNA. N{sup G}-nitro-L-arginine also attenuated the gradient in the latency of the off response by shortening latencies in muscle form the caudad esophagus. It had no effect on cholinergic nerve-induced contraction of longitudinal esophageal muscle. These data support the hypothesis that NO or an NO-containing compound mediates NANC nerve-induced responses of the esophagus and LES.

  6. Morphine-6beta-glucuronide modulates the expression of inducible nitric oxide synthase.

    PubMed

    Lysle, D T; Carrigan, K A

    2001-08-01

    The immunomodulatory effects of morphine are well established; however, suprisingly little is known about the immunomodulatory properties of the major metabolites of morphine. The present study tests the hypothesis that expression of inducible nitric oxide synthase (iNOS) is modulated by the administration of the morphine metabolite, morphine-6beta-glucuronide. The initial study using rats shows that morphine-6beta-glucuronide administration (0, 1.0, 3.163, 10 mg/kg s.c.) results in a pronounced reduction in lipopolysaccharide (LPS)-induced expression of iNOS (inducible nitricoxide synthease) in spleen, lung, and liver tissue as measured by western blotting. Morphine-6beta-glucuronide also produces a reduction in the level of plasma nitrite/nitrate, the more stable end-product of nitric oxide degradation. In a subsequent study, administration of the opioid receptor antagonist, naltrexone (0.1 mg/kg) prior to the injection of morphine-6beta-glucuronide (10 mg/kg) blocks the morphine-6beta-glucuronide induced reduction of iNOS expression and plasma nitrite/nitrite levels indicating that the effect is mediated via the opioid-receptor. This study provides the first evidence that morphine-6beta-glucuronide alters the expression of iNOS. PMID:11580103

  7. Involvement of Nitric Oxide, Neurotrophins and HPA Axis in Neurobehavioural Alterations Induced by Prenatal Stress.

    PubMed

    Maur, Damian G; Pascuan, Cecilia G; Genaro, Ana M; Zorrilla-Zubilete, Maria A

    2015-01-01

    Several studies suggest that negative emotions during pregnancy generate adverse effects on the cognitive, behavioural and emotional development of the descendants. The psychoneuroendocrine pathways involve the transplacentary passage of maternal glucocorticoids in order to influence directly on fetal growth and brain development.Nitric oxide is a gaseous neurotransmitter that plays an important role in the control of neural activity by diffusing into neurons and participates in learning and memory processes. It has been demonstrated that nitric oxide is involved in the regulation of corticosterone secretion. Thus, it has been found that the neuronal isoform of nitric oxide synthase (nNOS) is an endogenous inhibitor of glucocorticoid receptor (GR) in the hippocampus and that nNOS in the hippocampus may participate in the modulation of hypothalamic-pituitary-adrenal axis activity via GR.Neurotrophins are a family of secreted growth factors consisting of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and NT4. Although initially described in the nervous system, they regulate processes such as cell survival, proliferation and differentiation in several other compartments. It has been demonstrated that the NO-citrulline cycle acts together with BDNF in maintaining the progress of neural differentiation.In the present chapter, we explore the interrelation between nitric oxide, glucocorticoids and neurotrophins in brain areas that are key structures in learning and memory processes. The participation of this interrelation in the behavioural and cognitive alterations induced in the offspring by maternal stress is also addressed. PMID:25287536

  8. Immunosuppressive activity induced by nitric oxide in culture supernatant of activated rat alveolar macrophages.

    PubMed Central

    Kawabe, T; Isobe, K I; Hasegawa, Y; Nakashima, I; Shimokata, K

    1992-01-01

    Alveolar macrophages (AM) from normal rats had immunosuppressive activity to mitogen-induced proliferative responses of splenic lymphocytes. We studied the mechanism and the implication of the nitric oxide synthetase pathway in AM-mediated suppression of concanavalin A (Con A)-induced lymphocyte proliferation. The culture supernatant from AM cultures alone did not have immunosuppressive activity to Con A-induced proliferative responses of non-adherent spleen cells (n-ad SC), but the culture supernatant from co-culture of AM and autologous n-ad SC had this activity. Con A-pulsed AM also liberated the immunosuppressive factor. When AM and autologous n-ad SC were cultured separately under the condition that medium could freely communicate, the culture supernatant did not suppress the Con A-induced proliferative response of n-ad SC. This indicated that the immunosuppressive factor was liberated when AM was activated by cell-to-cell contact with n-ad SC. Further, we examined the immunosuppressive activity of the culture supernatant of co-culture of AM and autologous n-ad SC to Con A-induced responses of allogeneic n-ad SC and xenogeneic murine n-ad SC, and allogeneic mixed leucocyte reaction, and found that this culture supernatant could suppress all these proliferative responses. Nitrate (NO2-) synthesis was markedly augmented in the culture supernatants of Con A-pulsed AM and co-culture of AM and n-ad SC. NG-monomethyl-L-arginine (MMA), a specific competitive inhibitor of the nitric oxide synthetase pathway (NOSP), extinguished both NO2- synthesis by AM and AM-mediated immunosuppressive activity. These data suggest that NOSP was important in AM-mediated suppression of Con A-induced lymphocyte proliferation. PMID:1385798

  9. Palmitoylation of inducible nitric-oxide synthase at Cys-3 is required for proper intracellular traffic and nitric oxide synthesis.

    PubMed

    Navarro-Lérida, Inmaculada; Corvi, Maria Martha; Barrientos, Alberto Alvarez; Gavilanes, Francisco; Berthiaume, Luc Gérard; Rodríguez-Crespo, Ignacio

    2004-12-31

    A number of cell types express inducible nitric-oxide synthase (NOS2) in response to exogenous insults such as bacterial lipopolysaccharide or proinflammatory cytokines. Although it has been known for some time that the N-terminal end of NOS2 suffers a post-translational modification, its exact identification has remained elusive. Using radioactive fatty acids, we show herein that NOS2 becomes thioacylated at Cys-3 with palmitic acid. Site-directed mutagenesis of this single residue results in the absence of the radiolabel incorporation. Acylation of NOS2 is completely indispensable for intracellular sorting and .NO synthesis. In fact, a C3S mutant of NOS2 is completely inactive and accumulates to intracellular membranes that almost totally co-localize with the Golgi marker beta-cop. Likewise, low concentrations of the palmitoylation blocking agents 2-Br-palmitate or 8-Br-palmitate severely affected the .NO synthesis of both NOS2 induced in muscular myotubes and transfected NOS2. However, unlike endothelial NOS, palmitoylation of inducible NOS is not involved in its targeting to caveolae. We have created 16 NOS2-GFP chimeras to inspect the effect of the neighboring residues of Cys-3 on the degree of palmitoylation. In this regard, the hydrophobic residue Pro-4 and the basic residue Lys-6 seem to be indispensable for palmitoylation. In addition, agents that block the endoplasmic reticulum to Golgi transit such as brefeldin A and monensin drastically reduced NOS2 activity leading to its accumulation in perinuclear areas. In summary, palmitoylation of NOS2 at Cys-3 is required for both its activity and proper intracellular localization. PMID:15485846

  10. Heme oxygenase is involved in nitric oxide- and auxin-induced lateral root formation in rice.

    PubMed

    Chen, Yi-Hsuan; Chao, Yun-Yang; Hsu, Yun Yen; Hong, Chwan-Yang; Kao, Ching Huei

    2012-06-01

    Lateral root (LR) development performs the essential tasks of providing water, nutrients, and physical support to plants. Therefore, understanding the regulation of LR development is of agronomic importance. In this study, we examined the effect of nitric oxide (NO), auxin, and hemin (Hm) on LR formation in rice. Treatment with Hm [a highly effective heme oxygenase (HO) inducer], sodium nitroprusside (SNP, an NO donor), or indole-3-butyric acid (IBA, a naturally occurring auxin) induced LR formation and HO activity. LR formation and HO activity induced by SNP and IBA but not Hm was reduced by the specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. As well, Hm, SNP, and IBA could induce OsHO1 mRNA expression. Zn protoporphyrin IX (the specific inhibitor of HO) and hemoglobin (the carbon monoxide/NO scavenger) reduced LR number and HO activity induced by Hm, SNP, and IBA. Our data suggest that HO is required for Hm-, auxin-, and NO-induced LR formation in rice. PMID:22262313

  11. Nitric oxide mediates bleomycin-induced angiogenesis and pulmonary fibrosis via regulation of VEGF.

    PubMed

    Iyer, Anand Krishnan V; Ramesh, Vani; Castro, Carlos A; Kaushik, Vivek; Kulkarni, Yogesh M; Wright, Clayton A; Venkatadri, Rajkumar; Rojanasakul, Yon; Azad, Neelam

    2015-11-01

    Pulmonary fibrosis is a progressive lung disease hallmarked by increased fibroblast proliferation, amplified levels of extracellular matrix deposition and increased angiogenesis. Although dysregulation of angiogenic mediators has been implicated in pulmonary fibrosis, the specific rate-limiting angiogenic markers involved and their role in the progression of pulmonary fibrosis remains unclear. We demonstrate that bleomycin treatment induces angiogenesis, and inhibition of the central angiogenic mediator VEGF using anti-VEGF antibody CBO-P11 significantly attenuates bleomycin-induced pulmonary fibrosis in vivo. Bleomycin-induced nitric oxide (NO) was observed to be the key upstream regulator of VEGF via the PI3k/Akt pathway. VEGF regulated other important angiogenic proteins including PAI-1 and IL-8 in response to bleomycin exposure. Inhibition of NO and VEGF activity significantly mitigated bleomycin-induced angiogenic and fibrogenic responses. NO and VEGF are key mediators of bleomycin-induced pulmonary fibrosis, and could serve as important targets against this debilitating disease. Overall, our data suggests an important role for angiogenic mediators in the pathogenesis of bleomycin-induced pulmonary fibrosis. PMID:25919965

  12. Effects of the inducible nitric oxide synthase inhibitor aminoguanidine in two different rat models of schizophrenia.

    PubMed

    Lafioniatis, Anastasios; Orfanidou, Martha A; Papadopoulou, Evangelia S; Pitsikas, Nikolaos

    2016-08-01

    Several lines evidence indicate that the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist ketamine and the mixed dopamine (DA) D1/D2 receptor agonist apomorphine induce schizophrenia-like symptoms in rodents, including memory impairments and social withdrawal. Nitric oxide (NO) has been proposed to act as an intracellular messenger in the brain and its overproduction is associated with schizophrenia. The current study was designed to investigate the ability of the inducible NO synthase (iNOS) inhibitor aminoguanidine (AG) to counteract schizophrenia-like behavioural deficits produced by ketamine and apomorphine in rats. The efficacy of AG to antagonize extinction of recognition memory, ketamine and apomorphine-induced recognition memory impairments was tested utilizing the novel object recognition task (NORT). Further, the efficacy of AG to attenuate ketamine-induced social withdrawal was examined in the social interaction test. AG (25 and 50mg/kg) antagonized extinction of recognition memory and reversed ketamine (3mg/kg) and apomorphine (1mg/kg)-induced recognition memory deficits. In contrast, AG (50 and 100mg/kg) did not counteract the ketamine (8mg/kg)-induced social isolation. The present data show that the iNOS inhibitor AG counteracted extinction of recognition memory and reversed recognition memory deficits produced by dysfunction of the glutamatergic and the dopaminergic (DAergic) system in rats. Therefore, AG may be efficacious in attenuating memory impairments often observed in schizophrenia patients. PMID:27132765

  13. Neuronal nitric oxide synthase contributes to pentylenetetrazole-kindling-induced hippocampal neurogenesis.

    PubMed

    Zhu, Xinjian; Dong, Jingde; Shen, Kai; Bai, Ying; Chao, Jie; Yao, Honghong

    2016-03-01

    Neuronal nitric oxide synthase (nNOS), the major nitric oxide synthase isoform in the mammalian brain, is implicated in the pathophysiology of several neurological conditions, including epilepsy. Neurogenesis in hippocampal dentate gyrus (DG) persists throughout life in the adult brain. Alterations in this process occur in many neurological diseases, including epilepsy. Few studies, however, have addressed the role of nNOS in hippocampal DG neurogenesis in epileptic brain. The present study, therefore, investigated the role of nNOS in pentylenetetrazole (PTZ)-kindling-induced neurogenesis in hippocampal DG. Our results showed that nNOS expression and enzymatic activity were significantly increased in the hippocampus of PTZ-kindled mice. Meanwhile, these PTZ-kindled mice were characterized by significant enhancement of new born cells proliferation and survival in hippocampal DG, and these survived cells are co-labeled with NeuN and GFAP. Selective inhibition of nNOS by 7-NI, however, suppressed PTZ-kindling-induced hippocampal DG new born cells proliferation and survival, suggesting that nNOS contributes to PTZ-kindling-induced hippocampal neurogenesis. PMID:26820711

  14. Bisabolol-induced gastroprotection against acute gastric lesions: role of prostaglandins, nitric oxide, and KATP+ channels.

    PubMed

    Bezerra, S B; Leal, L K A M; Nogueira, N A P; Pinto, N A N; Campos, A R

    2009-12-01

    The effects of Matricaria recutita and alpha-bisabolol, a bioactive component from Chamomile species, were investigated against gastric damage induced by absolute ethanol (96%, 1 mL per animal) in rats. The effects of M. recutita extract and alpha-bisabolol on gastric mucosal damage were assessed by determination of changes in mean gastric lesion area. Mechanistic studies were carried out at with 100 mg=kg alpha-bisabolol. We further examined the possible participation of prostaglandins, nitric oxide, and KATP+ channels in its mechanism. M. recutita reduced gastric damage in all doses tested. Alpha-bisabolol at oral doses of 50 and 100 mg=kg markedly attenuated the gastric lesions induced by ethanol to the extent of 87% and 96%, respectively. Pretreatments with the nitric oxide antagonist N-nitro-l-arginine methyl ester (10 mg=kg, i.p.) or with indomethacin, an inhibitor of cyclooxygenase, failed to block effectively the gastroprotective effect of alpha-bisabolol. Furthermore, the alpha-bisabolol effect was significantly reduced in rats pretreated with glibenclamide, an inhibitor of KATP+ channel activation. Thus we provide evidence that alpha-bisabolol reduces the gastric damage induced by ethanol, at least in part, by the mechanism of activation of KATP+ channels. PMID:20041801

  15. Radiation-induced nitric oxide mitigates tumor hypoxia and radioresistance in a murine SCCVII tumor model.

    PubMed

    Nagane, Masaki; Yasui, Hironobu; Yamamori, Tohru; Zhao, Songji; Kuge, Yuji; Tamaki, Nagara; Kameya, Hiromi; Nakamura, Hideo; Fujii, Hirotada; Inanami, Osamu

    2013-08-01

    Tumor hypoxia, which occurs mainly as a result of inadequate tissue perfusion in solid tumors, is a well-known challenge for successful radiotherapy. Recent evidence suggests that ionizing radiation (IR) upregulates nitric oxide (NO) production and that IR-induced NO has the potential to increase intratumoral circulation. However, the kinetics of NO production and the responsible isoforms for NO synthase in tumors exposed to IR remain unclear. In this study, we aimed to elucidate the mechanism by which IR stimulates NO production in tumors and the effect of IR-induced NO on tumor radiosensitivity. Hoechst33342 perfusion assay and electron spin resonance oxymetry showed that IR increased tissue perfusion and pO2 in tumor tissue. Immunohistochemical analysis using two different hypoxic probes showed that IR decreased hypoxic regions in tumors; treatment with a nitric oxide synthase (NOS) inhibitor, L-NAME, abrogated the effects of IR. Moreover, IR increased endothelial NOS (eNOS) activity without affecting its mRNA or protein expression levels in SCCVII-transplanted tumors. Tumor growth delay assay showed that L-NAME decreased the anti-tumor effect of fractionated radiation (10Gy×2). These results suggested that IR increased eNOS activity and subsequent tissue perfusion in tumors. Increases in intratumoral circulation simultaneously decreased tumor hypoxia. As a result, IR-induced NO increased tumor radiosensitivity. Our study provides a new insight into the NO-dependent mechanism for efficient fractionated radiotherapy. PMID:23831468

  16. Astrovirus-Induced Synthesis of Nitric Oxide Contributes to Virus Control during Infection

    PubMed Central

    Koci, Matthew D.; Kelley, Laura A.; Larsen, Diane; Schultz-Cherry, Stacey

    2004-01-01

    Astrovirus is one of the major causes of infant and childhood diarrhea worldwide. Our understanding of astrovirus pathogenesis trails behind our knowledge of its molecular and epidemiologic properties. Using a recently developed small-animal model, we investigated the mechanisms by which astrovirus induces diarrhea and the role of both the adaptive and innate immune responses to turkey astrovirus type-2 (TAstV-2) infection. Astrovirus-infected animals were analyzed for changes in total lymphocyte populations, alterations in CD4+/CD8+ ratios, production of virus-specific antibodies (Abs), and macrophage activation. There were no changes in the numbers of circulating or splenic lymphocytes or in CD4+/CD8+ ratios compared to controls. Additionally, there was only a modest production of virus-specific Abs. However, adherent spleen cells from infected animals produced more nitric oxide (NO) in response to ex vivo stimulation with lipopolysaccharide. In vitro analysis demonstrated that TAstV-2 induced macrophage production of inducible nitric oxide synthase. Studies using NO donors and inhibitors in vivo demonstrated, for the first time, that NO inhibited astrovirus replication. These studies suggest that NO is important in limiting astrovirus replication and are the first, to our knowledge, to describe the potential role of innate immunity in astrovirus infection. PMID:14722310

  17. Selective inducible nitric oxide synthase inhibition attenuates organ dysfunction and elevated endothelin levels in LPS-induced DIC model rats.

    PubMed

    Asakura, H; Asamura, R; Ontachi, Y; Hayashi, T; Yamazaki, M; Morishita, E; Miyamoto, K-I; Nakao, S

    2005-05-01

    We examined the role of nitric oxide (NO) produced by an inducible isoform of NO synthase (iNOS) using N[6]-(iminoethyl)-lysine (L-NIL), a selective iNOS inhibitor, in the rat model of lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC) and investigated changes in organ function, plasma levels of NOX (metabolites of NO) and endothelin. We induced experimental DIC by the sustained infusion of 30 mg kg(-1) LPS for 4 h via the tail vein. We then investigated the effect of L-NIL (6 mg kg(-1), from - 0.5 to 4 h) on LPS-induced DIC. Blood was withdrawn at 4 and 8 h, and all four groups (LPS with or without L-NIL at 4 and 8 h) consisted of eight rats. Three of the animals in the 8-h LPS group died, and we examined blood samples from five rats in this group. None of the other rats died. The LPS-induced elevation of creatinine, alanine aminotransferase, glomerular fibrin deposition and plasminogen activator inhibitor was significantly suppressed by L-NIL coadministration, although L-NIL did not affect the platelet count, fibrinogen concentration or the level of thrombin-antithrombin complex. Moreover, plasma levels of the D-dimer that reflect the lysis of cross-linked fibrin were significantly increased by L-NIL coadministration in the LPS-induced DIC model. Plasma levels of NOX and endothelin were obviously increased by LPS infusion. However, both levels were significantly suppressed in the LPS + L-NIL group, when compared with the LPS group. Although mean arterial pressure (MAP) was significantly decreased between 2 and 8 h compared with the control in the LPS group, this depression was significantly attenuated in the LPS + L-NIL group. Our results suggest that NO induced by iNOS contributes to hypotension (depressed MAP), the progression of hepatic and renal dysfunction, microthrombus deposition and elevated endothelin levels in the rat model of LPS-induced DIC. PMID:15869603

  18. Nitric oxide is involved in hemin-induced cucumber adventitious rooting process.

    PubMed

    Xuan, Wei; Xu, Sheng; Li, Meiyue; Han, Bin; Zhang, Bo; Zhang, Jing; Lin, Yuting; Huang, Jingjing; Shen, Wenbiao; Cui, Jin

    2012-07-15

    Hemin, a heme oxygenase-1 (HO-1) inducer, was shown to exert numerous beneficial physiological functions in animals. Our previous study suggests that HO-1/carbon monoxide (CO) acts as a novel downstream signal system in the auxin-induced adventitious rooting. The objective of this study was to test whether nitric oxide (NO) is involved in hemin-induced cucumber adventitious rooting. Applications of hemin or CO aqueous solution to auxin-depleted cucumber explant induced up-regulation of cucumber HO-1 transcripts (CsHO1), NO production, and thereafter adventitious root formation, and some above responses were blocked by the combination treatment with two nitric oxide synthase (NOS)-like enzyme inhibitors N(G)-nitro-L-arginine methylester hydrochloride and N(G)-nitro-L-arginine, a HO-1 specific inhibitor zinc protoporphyrin IX, and a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt. However, these blocking responses were not observed using tungstate, an inhibitor of nitrate reductase, another NO producing enzyme in plants. Furthermore, the guanylate cyclase inhibitors 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one and 6-anilino-5,8-quinolinedione reduced root development induced by hemin, whereas the cell-permeable cyclic guanosine monophosphate (cGMP) derivative 8-Br-cGMP reversed this effect. Together, our results indicated that at least in our experimental conditions, NO might operate downstream of hemin promoting adventitious root formation probably in a cGMP-dependent manner. PMID:22579358

  19. Radiation-induced nitric oxide mitigates tumor hypoxia and radioresistance in a murine SCCVII tumor model

    SciTech Connect

    Nagane, Masaki; Yasui, Hironobu; Yamamori, Tohru; Zhao, Songji; Kuge, Yuji; Tamaki, Nagara; Kameya, Hiromi; Nakamura, Hideo; Fujii, Hirotada; Inanami, Osamu

    2013-08-02

    Highlights: •IR-induced NO increased tissue perfusion and pO{sub 2}. •IR increased NO production in tumors without changes in the mRNA and protein levels of NOS isoforms. •NOS activity assay showed that IR upregulated eNOS activity in tumors. •IR-induced NO decreased tumor hypoxia and altered tumor radiosensitivity. -- Abstract: Tumor hypoxia, which occurs mainly as a result of inadequate tissue perfusion in solid tumors, is a well-known challenge for successful radiotherapy. Recent evidence suggests that ionizing radiation (IR) upregulates nitric oxide (NO) production and that IR-induced NO has the potential to increase intratumoral circulation. However, the kinetics of NO production and the responsible isoforms for NO synthase in tumors exposed to IR remain unclear. In this study, we aimed to elucidate the mechanism by which IR stimulates NO production in tumors and the effect of IR-induced NO on tumor radiosensitivity. Hoechst33342 perfusion assay and electron spin resonance oxymetry showed that IR increased tissue perfusion and pO{sub 2} in tumor tissue. Immunohistochemical analysis using two different hypoxic probes showed that IR decreased hypoxic regions in tumors; treatment with a nitric oxide synthase (NOS) inhibitor, L-NAME, abrogated the effects of IR. Moreover, IR increased endothelial NOS (eNOS) activity without affecting its mRNA or protein expression levels in SCCVII-transplanted tumors. Tumor growth delay assay showed that L-NAME decreased the anti-tumor effect of fractionated radiation (10 Gy × 2). These results suggested that IR increased eNOS activity and subsequent tissue perfusion in tumors. Increases in intratumoral circulation simultaneously decreased tumor hypoxia. As a result, IR-induced NO increased tumor radiosensitivity. Our study provides a new insight into the NO-dependent mechanism for efficient fractionated radiotherapy.

  20. Lysophosphatidic acid induces vasodilation mediated by LPA1 receptors, phospholipase C, and endothelial nitric oxide synthase

    PubMed Central

    Ruisanchez, Éva; Dancs, Péter; Kerék, Margit; Németh, Tamás; Faragó, Bernadett; Balogh, Andrea; Patil, Renukadevi; Jennings, Brett L.; Liliom, Károly; Malik, Kafait U.; Smrcka, Alan V.; Tigyi, Gabor; Benyó, Zoltán

    2014-01-01

    Lysophosphatidic acid (LPA) has been implicated as a mediator of several cardiovascular functions, but its potential involvement in the control of vascular tone is obscure. Here, we show that both LPA (18:1) and VPC31143 (a synthetic agonist of LPA1–3 receptors) relax intact mouse thoracic aorta with similar Emax values (53.9 and 51.9% of phenylephrine-induced precontraction), although the EC50 of LPA- and VPC31143-induced vasorelaxations were different (400 vs. 15 nM, respectively). Mechanical removal of the endothelium or genetic deletion of endothelial nitric oxide synthase (eNOS) not only diminished vasorelaxation by LPA or VPC31143 but converted it to vasoconstriction. Freshly isolated mouse aortic endothelial cells expressed LPA1, LPA2, LPA4 and LPA5 transcripts. The LPA1,3 antagonist Ki16425, the LPA1 antagonist AM095, and the genetic deletion of LPA1, but not that of LPA2, abolished LPA-induced vasorelaxation. Inhibition of the phosphoinositide 3 kinase–protein kinase B/Akt pathway by wortmannin or MK-2206 failed to influence the effect of LPA. However, pharmacological inhibition of phospholipase C (PLC) by U73122 or edelfosine, but not genetic deletion of PLCε, abolished LPA-induced vasorelaxation and indicated that a PLC enzyme, other than PLCε, mediates the response. In summary, the present study identifies LPA as an endothelium-dependent vasodilator substance acting via LPA1, PLC, and eNOS.—Ruisanchez, É., Dancs, P., Kerék, M., Németh, T., Faragó, B., Balogh, A., Patil, R., Jennings, B. L., Liliom, K., Malik, K. U., Smrcka, A. V., Tigyi, G., Benyó, Z. Lysophosphatidic acid induces vasodilation mediated by LPA1 receptors, phospholipase C, and endothelial nitric oxide synthase. PMID:24249637

  1. Malarial anaemia and nitric oxide induced megaloblastic anaemia: a review on the causes of malarial anaemia.

    PubMed

    Pradhan, Prasanna

    2009-06-01

    Direct destruction and ineffective erythropoesis does not adequately explain the cause of anaemia in malaria. It is possible that there are more other mechanisms involved besides the causes described till date in malarial anaemia. The effect of NO on erythropoesis and a major haematological abnormality (microcytic/normocytic/megaloblastic picture) can significantly be observed on repeated exposure. In addition, NO can inhibit the enzyme methionine synthase so functional vit B12 deficiency state may occur which can lead to megaloblastic anaemia. This review will focus on causation of malarial anaemia and nitric oxide induced megaloblastic anaemia. PMID:19502689

  2. Proliferation of macrophages due to the inhibition of inducible nitric oxide synthesis by oxidized low-density lipoproteins

    PubMed Central

    Brunner, Monika; Gruber, Miriam; Schmid, Diethart; Baran, Halina; Moeslinger, Thomas

    2015-01-01

    Oxidized low-density lipoprotein (ox-LDL) is assumed to be a major causal agent in hypercholesteraemia-induced atherosclerosis. Because the proliferation of lipid-loaden macrophages within atherosclerotic lesions has been described, we investigated the dependence of macrophage proliferation on the inhibition of inducible nitric oxide synthase (iNOS) by hypochlorite oxidized LDL. Ox-LDL induces a dose dependent inhibition of inducible nitric oxide synthesis in lipopolysaccharide-interferon stimulated mouse macrophages (J774.A1) with concomitant macrophage proliferation as assayed by cell counting, tritiated-thymidine incorporation and measurement of cell protein. Native LDL did not influence macrophage proliferation and inducible nitric oxide synthesis. iNOS protein and mRNA was reduced by HOCl-oxidized LDL (0-40 µg/ml) as revealed by immunoblotting and competitive semiquantitative PCR. Macrophage proliferation was increased by the addition of the iNOS inhibitor L-NAME. The addition of ox-LDL to L-NAME containing incubations induced no further statistically significant increase in cell number. Nitric oxide donors decreased ox-LDL induced macrophage proliferation and nitric oxide scavengers restored macrophage proliferation to the initial values achieved by ox-LDL. The decrease of cytosolic DNA fragments in stimulated macrophages incubated with ox-LDL demonstrates that the proliferative actions of ox-LDL are associated with a decrease of NO-induced apoptosis. Our data show that inhibition of iNOS dependent nitric oxide production caused by hypochlorite oxidized LDL enhances macrophage proliferation. This might be a key event in the pathogenesis of atherosclerotic lesions. PMID:26600745

  3. Central release of nitric oxide mediates antinociception induced by aerobic exercise.

    PubMed

    Galdino, G S; Duarte, I D; Perez, A C

    2015-09-01

    Nitric oxide (NO) is a soluble gas that participates in important functions of the central nervous system, such as cognitive function, maintenance of synaptic plasticity for the control of sleep, appetite, body temperature, neurosecretion, and antinociception. Furthermore, during exercise large amounts of NO are released that contribute to maintaining body homeostasis. Besides NO production, physical exercise has been shown to induce antinociception. Thus, the present study aimed to investigate the central involvement of NO in exercise-induced antinociception. In both mechanical and thermal nociceptive tests, central [intrathecal (it) and intracerebroventricular (icv)] pretreatment with inhibitors of the NO/cGMP/KATP pathway (L-NOArg, ODQ, and glybenclamide) prevented the antinociceptive effect induced by aerobic exercise (AE). Furthermore, pretreatment (it, icv) with specific NO synthase inhibitors (L-NIO, aminoguanidine, and L-NPA) also prevented this effect. Supporting the hypothesis of the central involvement of NO in exercise-induced antinociception, nitrite levels in the cerebrospinal fluid increased immediately after AE. Therefore, the present study suggests that, during exercise, the NO released centrally induced antinociception. PMID:25517916

  4. Inhaled nitric oxide exacerbated phorbol-induced acute lung injury in rats.

    PubMed

    Lin, Hen I; Chu, Shi Jye; Hsu, Kang; Wang, David

    2004-01-01

    In this study, we determined the effect of inhaled nitric oxide (NO) on the acute lung injury induced by phorbol myristate acetate (PMA) in isolated rat lung. Typical acute lung injury was induced successfully by PMA during 60 min of observation. PMA (2 microg/kg) elicited a significant increase in microvascular permeability, (measured using the capillary filtration coefficient Kfc), lung weight gain, lung weight/body weight ratio, pulmonary arterial pressure (PAP) and protein concentration of the bronchoalveolar lavage fluid. Pretreatment with inhaled NO (30 ppm) significantly exacerbated acute lung injury. All of the parameters reflective of lung injury increased significantly except PAP (P<0.05). Coadministration of Nomega-nitro-L-arginine methyl ester (L-NAME) (5 mM) attenuated the detrimental effect of inhaled NO in PMA-induced lung injury, except for PAP. In addition, L-NAME (5 mM) significantly attenuated PMA-induced acute lung injury except for PAP. These experimental data suggest that inhaled NO significantly exacerbated acute lung injury induced by PMA in rats. L-NAME attenuated the detrimental effect of inhaled NO. PMID:14643171

  5. Guard cell hydrogen peroxide and nitric oxide mediate elevated CO2 -induced stomatal movement in tomato.

    PubMed

    Shi, Kai; Li, Xin; Zhang, Huan; Zhang, Guanqun; Liu, Yaru; Zhou, Yanhong; Xia, Xiaojian; Chen, Zhixiang; Yu, Jingquan

    2015-10-01

    Climate change as a consequence of increasing atmospheric CO2 influences plant photosynthesis and transpiration. Although the involvement of stomata in plant responses to elevated CO2 has been well established, the underlying mechanism of elevated CO2 -induced stomatal movement remains largely unknown. We used diverse techniques, including laser scanning confocal microscopy, transmission electron microscopy, biochemical methodologies and gene silencing to investigate the signaling pathway for elevated CO2 -induced stomatal movement in tomato (Solanum lycopersicum). Elevated CO2 -induced stomatal closure was dependent on the production of RESPIRATORY BURST OXIDASE 1 (RBOH1)-mediated hydrogen peroxide (H2 O2 ) and NITRATE REDUCTASE (NR)-mediated nitric oxide (NO) in guard cells in an abscisic acid (ABA)-independent manner. Silencing of OPEN STOMATA 1 (OST1) compromised the elevated CO2 -induced accumulation of H2 O2 and NO, upregulation of SLOW ANION CHANNEL ASSOCIATED 1 (SLAC1) gene expression and reduction of stomatal aperture, whereas silencing of RBOH1 or NR had no effects on the expression of OST1. Our results demonstrate that as critical signaling molecules, RBOH1-dependent H2 O2 and NR-dependent NO act downstream of OST1 that regulate SLAC1 expression and elevated CO2 -induced stomatal movement. This information is crucial to deepen the understanding of CO2 signaling pathway in guard cells. PMID:26308648

  6. Spectroscopic measurement of cortical nitric oxide release induced by ascending activation.

    PubMed

    Espinosa, N; Cudeiro, J; Mariño, J

    2015-01-29

    The transition from sleep to the awake state is regulated by the activation of subcortical nuclei of the brainstem (BS) and basal forebrain (BF), releasing acetylcholine and glutamate throughout the cortex and inducing a tonic state of neural activity. It has been suggested that such activation is also mediated by the massive and diffuse cortical release of nitric oxide (NO). In this work we have combined the spectroscopic measurement of NO levels in the somatosensory cortex of the cat through its marker methemoglobin, as well as two other hemodynamic markers (oxyhemoglobin--oxyHb--and deoxyhemoglobin--deoxyHb), together with the electrical stimulation of BS and BF--to induce an experimental transition from a sleep-like state to an awake-like mode. The results show an increase of NO levels either after BS or BF activation. The response induced by BS stimulation was biphasic in the three studied markers, and lasted for up to 30s. The changes induced by BF were monophasic lasting for up to 20s. The systemic blockade of NO production abolished the observed responses to BS whereas responses to BF stimulation were much less affected. These results indicate a crucial role for NO in the neuronal activation induced by the ascending systems. PMID:25463513

  7. Nitric oxide mediates stretch-induced Ca2+ oscillation in smooth muscle.

    PubMed

    Zheng, Ji; Zhai, Kui; Chen, Yingxiao; Zhang, Xu; Miao, Lin; Wei, Bin; Ji, Guangju

    2016-06-15

    The stretching of smooth muscle tissue modulates contraction through augmentation of Ca(2+) transients, but the mechanism underlying stretch-induced Ca(2+) transients is still unknown. We found that mechanical stretching and maintenance of mouse urinary bladder smooth muscle strips and single myocytes at 30% and 18% beyond the initial length, respectively, resulted in Ca(2+) oscillations. Experiments indicated that mechanical stretching remarkably increased the production of nitric oxide (NO) as well as the amplitude and duration of muscle contraction. Stretch-induced Ca(2+) oscillations and contractility increases were completely abolished by the NO inhibitor L-NAME or eNOS (also known as NOS3) gene inactivation. Moreover, exposure of eNOS-knockout myocytes to exogenous NO donor induced Ca(2+) oscillations. The stretch-induced Ca(2+) oscillations were greatly inhibited by the selective inositol 1,4,5-trisphosphate receptor (IP3R) inhibitor xestospongin C and partially inhibited by ryanodine. Moreover, the stretch-induced Ca(2+) oscillations were also suppressed by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, but not by the soluble guanylyl cyclase (sGC) inhibitor ODQ. These results suggest that stretching myocyte and maintenance at a certain length results in Ca(2+) oscillations that are NO dependent , and sGC and cGMP independent, and results from the activation of PI3K in smooth muscle. PMID:27189081

  8. Atorvastatin-induced cardioprotection is mediated by increasing inducible nitric oxide synthase and consequent S-nitrosylation of cyclooxygenase-2.

    PubMed

    Atar, Shaul; Ye, Yumei; Lin, Yu; Freeberg, Sheldon Y; Nishi, Shawn P; Rosanio, Salvatore; Huang, Ming-He; Uretsky, Barry F; Perez-Polo, Jose R; Birnbaum, Yochai

    2006-05-01

    We determined the effects of cyclooxygenase-1 (COX-1; SC-560), COX-2 (SC-58125), and inducible nitric oxide synthase (iNOS; 1400W) inhibitors on atorvastatin (ATV)-induced myocardial protection and whether iNOS mediates the ATV-induced increases in COX-2. Sprague-Dawley rats received 10 mg ATV.kg(-1).day(-1) added to drinking water or water alone for 3 days and received intravenous SC-58125, SC-560, 1400W, or vehicle alone. Anesthesia was induced with ketamine and xylazine and maintained with isoflurane. Fifteen minutes after intravenous injection rats underwent 30-min myocardial ischemia followed by 4-h reperfusion [infarct size (IS) protocol], or the hearts were explanted for biochemical analysis and immunoblotting. Left ventricular weight and area at risk (AR) were comparable among groups. ATV reduced IS to 12.7% (SD 3.1) of AR, a reduction of 64% vs. 35.1% (SD 7.6) in the sham-treated group (P < 0.001). SC-58125 and 1400W attenuated the protective effect without affecting IS in the non-ATV-treated rats. ATV increased calcium-independent NOS (iNOS) [11.9 (SD 0.8) vs. 3.9 (SD 0.1) x 1,000 counts/min; P < 0.001] and COX-2 [46.7 (SD 1.1) vs. 6.5 (SD 1.4) pg/ml of 6-keto-PGF(1alpha); P < 0.001] activity. Both SC-58125 and 1400W attenuated this increase. SC-58125 did not affect iNOS activity, whereas 1400W blocked iNOS activity. COX-2 was S-nitrosylated in ATV-treated but not sham-treated rats or rats pretreated with 1400W. COX-2 immunoprecipitated with iNOS but not with endothelial nitric oxide synthase. We conclude that ATV reduced IS by increasing the activity of iNOS and COX-2, iNOS is upstream to COX-2, and iNOS activates COX-2 by S-nitrosylation. These results are consistent with the hypothesis that preconditioning effects are mediated via PG. PMID:16339820

  9. Nitric oxide induces prion protein via MEK and p38 MAPK signaling.

    PubMed

    Wang, Vinchi; Chuang, Tzu-Chao; Hsu, Yaw-Don; Chou, Wei-Yuan; Kao, Ming-Ching

    2005-07-22

    The prion diseases or transmissible spongiform encephalopathy, such as human Creutzfeldt-Jakob disease (CJD) and so-called mad cow disease, are attributed to the causative agent, the scrapie variant of prion protein (PrP(Sc)) which causes fatal neurodegeneration. To investigate if stresses such as nitric oxide (NO) induced the cellular isoform of prion protein (PrP(C)), lipopolysaccharide, and sodium nitroprusside were used to treat N2a and NT2 cells, which resulted in elevated levels of the PRNP mRNA and prion protein. The signaling pathway for the NO-induced PrP(C) production involved guanylyl cyclase, MEK, and p38 MAPK as shown by the effect of specific pharmacological inhibitors ODQ, PD98059, and SB203580, respectively. Knowing the PrP induction by the biologically existing stimulus, this study provides useful information about the possible cellular mechanism and strategies for the treatment of CJD. PMID:15936714

  10. Up-Regulation of Human Inducible Nitric Oxide Synthase by p300 Transcriptional Complex.

    PubMed

    Guo, Zhong; Zheng, Liang; Liao, Xinghua; Geller, David

    2016-01-01

    p300, a ubiquitous transcription coactivator, plays an important role in gene activation. Our previous work demonstrated that human inducible nitric oxide synthase (hiNOS) expression can be highly induced with the cytokine mixture (CM) of TNF-α + IL-1β + IFN-γ. In this study, we investigated the functional role of p300 in the regulation of hiNOS gene expression. Our initial data showed that overexpression of p300 significantly increased the basal and cytokine-induced hiNOS promoter activities in A549 cells. Interestingly, p300 activated cytokine-induced hiNOS transcriptional activity was completely abrogated by deleting the upstream hiNOS enhancer at -5 kb to -6 kb in the promoter. Furthermore, p300 over-expression increased cytokine-induced transcriptional activity on a heterologous minimal TK promoter with the same hiNOS enhancer. Site-directed mutagenesis of the hiNOS AP-1 motifs revealed that an intact upstream (-5.3 kb) AP-1 binding site was critical for p300 mediated cytokine-induced hiNOS transcription. Furthermore, our ChIP analysis demonstrated that p300 was binding to Jun D and Fra-2 proteins at -5.3 kb AP-1 binding site in vivo. Lastly, our 3C assay was able to detect a long DNA loop between the hiNOS enhancer and core promoter site, and ChIP loop assay confirmed that p300 binds to AP-1 and RNA pol II proteins. Overall, our results suggest that coactivator p300 mediates cytokine-induced hiNOS transactivation by forming a distant DNA loop between its enhancer and core promoter region. PMID:26751080

  11. Expression of Inducible Nitric Oxide Synthase (iNOS) in Microglia of the Developing Quail Retina

    PubMed Central

    Sierra, Ana; Navascués, Julio; Cuadros, Miguel A.; Calvente, Ruth; Martín-Oliva, David; Ferrer-Martín, Rosa M.; Martín-Estebané, María; Carrasco, María-Carmen; Marín-Teva, José L.

    2014-01-01

    Inducible nitric oxide synthase (iNOS), which produce large amounts of nitric oxide (NO), is induced in macrophages and microglia in response to inflammatory mediators such as LPS and cytokines. Although iNOS is mainly expressed by microglia that become activated in different pathological and experimental situations, it was recently reported that undifferentiated amoeboid microglia can also express iNOS during normal development. The aim of this study was to investigate the pattern of iNOS expression in microglial cells during normal development and after their activation with LPS by using the quail retina as model. iNOS expression was analyzed by iNOS immunolabeling, western-blot, and RT-PCR. NO production was determined by using DAR-4M AM, a reliable fluorescent indicator of subcellular NO production by iNOS. Embryonic, postnatal, and adult in situ quail retinas were used to analyze the pattern of iNOS expression in microglial cells during normal development. iNOS expression and NO production in LPS-treated microglial cells were investigated by an in vitro approach based on organotypic cultures of E8 retinas, in which microglial cell behavior is similar to that of the in situ retina, as previously demonstrated in our laboratory. We show here that amoeboid microglia in the quail retina express iNOS during normal development. This expression is stronger in microglial cells migrating tangentially in the vitreal part of the retina and is downregulated, albeit maintained, when microglia differentiate and become ramified. LPS treatment of retina explants also induces changes in the morphology of amoeboid microglia compatible with their activation, increasing their lysosomal compartment and upregulating iNOS expression with a concomitant production of NO. Taken together, our findings demonstrate that immature microglial cells express iNOS during normal development, suggesting a certain degree of activation. Furthermore, LPS treatment induces overactivation of amoeboid

  12. Inducible nitric oxide synthase gene methylation and parkinsonism in manganese-exposed welders

    PubMed Central

    Nielsen, Susan Searles; Checkoway, Harvey; Criswell, Susan R.; Farin, Federico M.; Stapleton, Patricia L.; Sheppard, Lianne; Racette, Brad A.

    2015-01-01

    Introduction Neurologist-assessed parkinsonism signs are prevalent among workers exposed to manganese (Mn)-containing welding fume. Neuroinflammation may possibly play a role. Inducible nitric oxide synthase, coded by NOS2, is involved in inflammation, and particulate exposure increases the gene’s expression through methylation of CpG sites in the 5′ region. Methods We assessed DNA methylation at three CpG sites in the NOS2 exon 1 from blood from 201 welders. All were non-Hispanic Caucasian men 25–65 years old who were examined by a neurologist specializing in movement disorders. We categorized the workers according to their Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3) scores as parkinsonism cases (UPDRS3 ≥ 15; n = 49), controls (UPDRS3 < 6; n = 103), or intermediate (UPDRS3 ≥6 to <15; n = 49). Results While accounting for age, examiner and experimental plate, parkinsonism cases had lower mean NOS2 methylation than controls (p-value for trend = 0.04), specifically at CpG site 8329 located in an exonic splicing enhancer of NOS2 (p-value for trend = 0.07). These associations were not observed for the intermediate UPDRS3 group (both p-value for trend ≥ 0.59). Conclusions Inflammation mediated by inducible nitric oxide synthase may possibly contribute to the association between welding fume and parkinsonism, but requires verification in a longitudinal study. PMID:25634431

  13. EBP50 induces apoptosis in macrophages by upregulating nitric oxide production to eliminate intracellular Mycobacterium tuberculosis

    PubMed Central

    Guo, Yang; Deng, Yating; Huang, Zikun; Luo, Qing; Peng, Yiping; Chen, Jie; Jiang, Hong; Ye, Jianqing; Li, Junming

    2016-01-01

    Mycobacterium bovis BCG is known to have the capacity to inhibit the positioning of iNOS on BCG-containing phagosomes by interfering with EBP50, a scaffolding protein that controls the recruitment of inducible nitric oxide synthase (iNOS) at the vicinity of phagosomes in macrophages. However, knockdown of the expression of EBP50 still facilitates the intracellular survival of BCG, which suggested that EBP50 may have some other unknown antimycobacterial properties. In this study we show that overexpression of EBP50 by a recombinant lentivirus had no effect on the iNOS recruitment to M.tuberculosis-containing phagosomes, but significantly promoted the elimination of intracellular M.tuberculosis. We revealed in the present study that the enhancement of intracellular killing to M. tuberculosis upon EBP50 overexpression was due to the increased level of apoptosis in macrophages. We showed that EBP50 overexpression significantly increased the expression of iNOS and generation of nitric oxide (NO), and EBP50-induced apoptosis was NO-dependent and mediated by Bax and caspase-3. We found that M. tuberculosis decreases while Mycobacterium smegmatis increases the expression of EBP50 in RAW264.7 cells, which suggested that virulent mycobacteria are capable of modulating the antimycobacterial properties of macrophages by inhibiting the expression and interfering with the function of EBP50. PMID:26729618

  14. Nitric Oxide Acts as a Positive Regulator to Induce Metamorphosis of the Ascidian Herdmania momus

    PubMed Central

    Ueda, Nobuo; Degnan, Sandie M.

    2013-01-01

    Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO) is synthesised by nitric oxide synthase (NOS), which is a client protein of the molecular chaperon heat shock protein 90 (HSP90). It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation in ascidian

  15. Role of nitric oxide in adenosine-induced vasodilation in humans

    NASA Technical Reports Server (NTRS)

    Costa, F.; Biaggioni, I.; Robertson, D. (Principal Investigator)

    1998-01-01

    Vasodilation is one of the most prominent effects of adenosine and one of the first to be recognized, but its mechanism of action is not completely understood. In particular, there is conflicting information about the potential contribution of endothelial factors. The purpose of this study was to explore the role of nitric oxide in the vasodilatory effect of adenosine. Forearm blood flow responses to intrabrachial adenosine infusion (125 microg/min) were assessed with venous occlusion plethysmography during intrabrachial infusion of saline or the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) (12.5 mg/min). Intrabrachial infusions of acetylcholine (50 microg/min) and nitroprusside (3 microg/min) were used as a positive and negative control, respectively. These doses were chosen to produce comparable levels of vasodilation. In a separate study, a second saline infusion was administered instead of L-NMMA to rule out time-related effects. As expected, pretreatment with L-NMMA reduced acetylcholine-induced vasodilation; 50 microg/min acetylcholine increased forearm blood flow by 150+/-43% and 51+/-12% during saline and L-NMMA infusion, respectively (P<.01, n=6). In contrast, L-NMMA did not affect the increase in forearm blood flow produced by 3 microg/min nitroprusside (165+/-30% and 248+/-41% during saline and L-NMMA, respectively) or adenosine (173+/-48% and 270+/-75% during saline and L-NMMA, respectively). On the basis of our observations, we conclude that adenosine-induced vasodilation is not mediated by nitric oxide in the human forearm.

  16. Absence of inducible nitric oxide synthase reduces myocardial damage during ischemia reperfusion in streptozotocin-induced hyperglycemic mice.

    PubMed

    Marfella, Raffaele; Di Filippo, Clara; Esposito, Katherine; Nappo, Francesco; Piegari, Elena; Cuzzocrea, Salvatore; Berrino, Liberato; Rossi, Francesco; Giugliano, Dario; D'Amico, Michele

    2004-02-01

    We investigated the role of inducible nitric oxide synthase (iNOS) on ischemic myocardial damage and angiogenic process in genetically deficient iNOS (iNOS(-/-)) mice and wild-type littermates (iNOS(+/+)), with and without streptozotocin-induced (70 mg/kg intravenously) diabetes. After ischemia (25 min) and reperfusion (120 min), both iNOS(+/+) and iNOS(-/-) diabetic mice (blood glucose 22 mmol/l) had myocardial infarct size greater than their respective nondiabetic littermates (P < 0.01). Myocardial infarct size (P < 0.05), apoptotic index (P < 0.005), and tissue levels of tumor necrosis factor (P < 0.01), interleukin-6 (P < 0.01), and interleukin-18 (P < 0.01) were higher in nondiabetic iNOS(-/-) mice compared with nondiabetic iNOS(+/+) mice. As compared with diabetic iNOS(-/-) mice, diabetic iNOS(+/+) mice showed a greater infarct size (P < 0.01) associated with the highest tissue levels of nitrotyrosine and proinflammatory cytokines, as well as apoptosis. The beneficial role of iNOS in modulating defensive responses against ischemia/reperfusion injury seems to be abolished in diabetic mice. PMID:14747298

  17. Nitric oxide is required for hydrogen gas-induced adventitious root formation in cucumber.

    PubMed

    Zhu, Yongchao; Liao, Weibiao; Wang, Meng; Niu, Lijuan; Xu, Qingqing; Jin, Xin

    2016-05-20

    Hydrogen gas (H2) is involved in plant development and stress responses. Cucumber explants were used to study whether nitric oxide (NO) is involved in H2-induced adventitious root development. The results revealed that 50% and 100% hydrogen-rich water (HRW) apparently promoted the development of adventitious root in cucumber. While, the responses of HRW-induced adventitious rooting were blocked by a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), NO synthase (NOS) enzyme inhibitor N(G)-nitro-l-arginine methylester hydrochloride (l-NAME) and nitrate reductase (NR) inhibitor NaN3. HRW also increased NO content and NOS and NR activity both in a dose- and time-dependent fashion. Moreover, molecular evidence showed that HRW up-regulated NR genes expression in explants. The results indicate the importance of NOS and NR enzymes, which might be responsible for NO production in explants during H2-induced root organogenesis. Additionally, peroxidase (POD) and indoleacetic acid oxidase (IAAO) activity was significantly decreased in the explants treated with HRW, while HRW treatment significantly increased polyphenol oxidase (PPO) activity. In addition, cPTIO, l-NAME and NaN3 inhibited the actions of HRW on the activity of these enzymes. Together, NO may be involved in H2-induced adventitious rooting, and NO may be acting downstream in plant H2 signaling cascade. PMID:27010347

  18. Neuronal and inducible nitric oxide synthase upregulation in the rat medial prefrontal cortex following acute restraint stress: A dataset.

    PubMed

    Spiers, Jereme G; Chen, Hsiao-Jou Cortina; Lee, Johnny K; Sernia, Conrad; Lavidis, Nickolas A

    2016-03-01

    This data article provides additional evidence on gene expression changes in the neuronal and inducible isoforms of nitric oxide synthase in the medial prefrontal cortex following acute stress. Male Wistar rats aged 6-8 weeks were exposed to control or restraint stress conditions for up to four hours in the dark cycle after which the brain was removed and the medial prefrontal cortex isolated by cryodissection. Following RNA extraction and cDNA synthesis, gene expression data were measured using quantitative real-time PCR. The mRNA levels of the neuronal and inducible nitric oxide synthase isoforms, and the inhibitory subunit of NF-κB, I kappa B alpha were determined using the ΔΔCT method relative to control animals. This data article presents complementary results related to the research article entitled 'Acute restraint stress induces specific changes in nitric oxide production and inflammatory markers in the rat hippocampus and striatum' [1]. PMID:26909371

  19. Pulmonary surfactant inhibits LPS-induced nitric oxide production by alveolar macrophages.

    PubMed

    Miles, P R; Bowman, L; Rao, K M; Baatz, J E; Huffman, L

    1999-01-01

    The objectives of this investigation were 1) to report that pulmonary surfactant inhibits lipopolysaccharide (LPS)-induced nitric oxide (. NO) production by rat alveolar macrophages, 2) to study possible mechanisms for this effect, and 3) to determine which surfactant component(s) is responsible. NO produced by the cells in response to LPS is due to an inducible. NO synthase (iNOS). Surfactant inhibits LPS-induced. NO formation in a concentration-dependent manner;. NO production is inhibited by approximately 50 and approximately 75% at surfactant levels of 100 and 200 microg phospholipid/ml, respectively. The inhibition is not due to surfactant interference with the interaction of LPS with the cells or to disruption of the formation of iNOS mRNA. Also, surfactant does not seem to reduce. NO formation by directly affecting iNOS activity or by acting as an antioxidant or radical scavenger. However, in the presence of surfactant, there is an approximately 80% reduction in the amount of LPS-induced iNOS protein in the cells. LPS-induced. NO production is inhibited by Survanta, a surfactant preparation used in replacement therapy, as well as by natural surfactant. NO formation is not affected by the major lipid components of surfactant or by two surfactant-associated proteins, surfactant protein (SP) A or SP-C. However, the hydrophobic SP-B inhibits. NO formation in a concentration-dependent manner;. NO production is inhibited by approximately 50 and approximately 90% at SP-B levels of 1-2 and 10 microgram/ml, respectively. These results show that lung surfactant inhibits LPS-induced. NO production by alveolar macrophages, that the effect is due to a reduction in iNOS protein levels, and that the surfactant component responsible for the reduction is SP-B. PMID:9887071

  20. Endothelial Nitric Oxide Mediates Caffeine Antagonism of Alcohol-Induced Cerebral Artery Constriction.

    PubMed

    Chang, Jennifer; Fedinec, Alexander L; Kuntamallappanavar, Guruprasad; Leffler, Charles W; Bukiya, Anna N; Dopico, Alex M

    2016-01-01

    Despite preventive education, the combined consumption of alcohol and caffeine (particularly from "energy drinks") continues to rise. Physiologic perturbations by separate intake of ethanol and caffeine have been widely documented. However, the biologic actions of the alcohol-caffeine combination and their underlying subcellular mechanisms have been scarcely studied. Using intravital microscopy on a closed-cranial window and isolated, pressurized vessels, we investigated the in vivo and in vitro action of ethanol-caffeine mixtures on cerebral arteries from rats and mice, widely recognized models to address cerebrovascular pathophysiology and pharmacology. Caffeine at concentrations found in human circulation after ingestion of one to two cups of coffee (10 µM) antagonized the endothelium-independent constriction of cerebral arteries evoked by ethanol concentrations found in blood during moderate-heavy alcohol intoxication (40-70 mM). Caffeine antagonism against alcohol was similar whether evaluated in vivo or in vitro, suggesting independence of systemic factors and drug metabolism, but required a functional endothelium. Moreover, caffeine protection against alcohol increased nitric oxide (NO•) levels over those found in the presence of ethanol alone, disappeared upon blocking NO• synthase, and could not be detected in pressurized cerebral arteries from endothelial nitric-oxide synthase knockout (eNOS(-/-)) mice. Finally, incubation of de-endothelialized cerebral arteries with the NO• donor sodium nitroprusside (10 µM) fully restored the protective effect of caffeine. This study demonstrates for the first time that caffeine antagonizes ethanol-induced cerebral artery constriction and identifies endothelial NO• as the critical caffeine effector on smooth muscle targets. Conceivably, situations that perturb endothelial function and/or NO• availability will critically alter caffeine antagonism of alcohol-induced cerebrovascular constriction without

  1. Nitric oxide modulates lipopolysaccharide-induced endothelial platelet endothelial cell adhesion molecule expression via interleukin-10.

    PubMed

    Hebeda, C B; Teixeira, S A; Tamura, E K; Muscará, M N; de Mello, S B V; Markus, R P; Farsky, S H P

    2011-08-01

    We have shown previously that nitric oxide (NO) controls platelet endothelial cell adhesion molecule (PECAM-1) expression on both neutrophils and endothelial cells under physiological conditions. Here, the molecular mechanism by which NO regulates lipopolysaccharide (LPS)-induced endothelial PECAM-1 expression and the role of interleukin (IL)-10 on this control was investigated. For this purpose, N-(G)-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg/day for 14 days dissolved in drinking water) was used to inhibit both constitutive (cNOS) and inducible nitric oxide (iNOS) synthase activities in LPS-stimulated Wistar rats (5 mg/kg, intraperitoneally). This treatment resulted in reduced levels of serum NO. Under this condition, circulating levels of IL-10 was enhanced, secreted mainly by circulating lymphocytes, dependent on transcriptional activation, and endothelial PECAM-1 expression was reduced independently on reduced gene synthesis. The connection between NO, IL-10 and PECAM-1 expression was examined by incubating LPS-stimulated (1 µg/ml) cultured endothelial cells obtained from naive rats with supernatant of LPS-stimulated lymphocytes, which were obtained from blood of control or L-NAME-treated rats. Supernatant of LPS-stimulated lymphocytes obtained from L-NAME-treated rats, which contained higher levels of IL-10, reduced LPS-induced PECAM-1 expression by endothelial cells, and this reduction was reversed by adding the anti-IL-10 monoclonal antibody. Therefore, an association between NO, IL-10 and PECAM-1 was found and may represent a novel mechanism by which NO controls endothelial cell functions. PMID:21564091

  2. Role of nitric oxide and cyclic GMP in glutamate-induced neuronal death.

    PubMed

    Montoliu, C; Llansola, M; Monfort, P; Corbalan, R; Fernandez-Marticorena, I; Hernandez-Viadel, M L; Felipo, V

    2001-04-01

    Glutamate is the main excitatory neurotransmitter in mammals. However, excessive activation of glutamate receptors is neurotoxic, leading to neuronal degeneration and death. In many systems, including primary cultures of cerebellar neurons, glutamate neurotoxicity is mainly mediated by excessive activation of NMDA receptors, leading to increased intracellular calcium which binds to calmodulin and activates neuronal nitric oxide synthase (NOS), increasing nitric oxide (NO) which in turn activates guanylate cyclase and increases cGMP. Inhibition of NOS prevents glutamate neurotoxicity, indicating that NO mediates glutamate-induced neuronal death in this system. NO generating agents such as SNAP also induce neuronal death. Compounds that can act as "scavengers" of NO such as Croman 6 (CR-6) prevent glutamate neurotoxicity. The role of cGMP in the mediation of glutamate neurotoxicity remains controversial. Some reports indicate that cGMP mediates glutamate neurotoxicity while others indicate that cGMP is neuroprotective. We have studied the role of cGMP in the mediation of glutamate and NO neurotoxicity in cerebellar neurons. Inhibition of soluble guanylate cyclase prevents glutamate and NO neurotoxicity. There is a good correlation between inhibition of cGMP formation and neuroprotection. Moreover 8-Br-cGMP, a cell permeable analog of cGMP, induced neuronal death. These results indicate that increased intracellular cGMP is involved in the mechanism of neurotoxicity. Inhibitors of phosphodiesterase increased extracellular but not intracellular cGMP and prevented glutamate neurotoxicity. Addition of cGMP to the medium also prevented glutamate neurotoxicity. These results are compatible with a neurotoxic effect of increased intracellular cGMP and a neuroprotective effect of increased extracellular cGMP. PMID:14715472

  3. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation.

    PubMed

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  4. Nitric oxide metabolites in patients with asthma: induced sputum versus blood.

    PubMed

    Jang, A S; Choi, I S

    1999-12-01

    Nitric oxide (NO) plays an important role in physiological regulation of the airways. The monitoring of airway inflammation has being observed in bronchial asthma directly, by sputum examination, and indirectly, by measurements in peripheral blood. To investigate the diagnostic value of these two methods, we compared NO metabolites in induced sputum and serum obtained in patients with asthma and control subjects. Hypertonic saline induced sputum and serum were obtained in 13 patients with asthma and 10 control subjects. NO metabolite level was assayed by using modified Griess reaction. Eosinophil cationic protein (ECP) was measured by fluoroimmunoassay, and detected interleukin (IL)-5 by a sandwich ELISA. The accuracy of the tests was measured by plotting the data in receiver operating characteristic (ROC) curves and comparing the area under the curve for NO metabolites. Asthmatic patients, compared with control subjects, had significantly higher NO metabolites in induced sputum (1252.5+/-203.3 mol l(-1) vs. 557.2+/-101.5 mol l(-1), P<0.01) but not in serum. IL-5 in induced sputum was detected more frequently in patients with asthma than in control subjects [11/13 (84.6%) vs. 1/10 (10%), P<0.01]. Asthmatic patients, compared with control subjects, had significantly higher ECP concentration in induced sputum (1270.0+/-197.9 g l vs. 154.6+/-47.4 g l(-1), P<0.01). There were significant positive correlations between NO metabolites in induced sputum and eosinophils, ECP in induced sputum (r=0.58 P<0.05; r=0.64, P<0.01) in patients with asthma but not in serum. The area under the ROC curve showed that NO metabolites in induced sputum (0.78) are more accurate marker than NO metabolites in serum (0.53) (P<0.05). These findings suggest that NO metabolites in induced sputum is a more valuable indicator to monitor asthmatic airway inflammation than those in serum. PMID:10653055

  5. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    NASA Astrophysics Data System (ADS)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  6. Nitric oxide activates superoxide dismutase and ascorbate peroxidase to repress the cell death induced by wounding.

    PubMed

    Lin, Chih-Ching; Jih, Pei-Ju; Lin, Hsin-Hung; Lin, Jeng-Shane; Chang, Ling-Lan; Shen, Yu-Hsing; Jeng, Shih-Tong

    2011-10-01

    Wounding caused by rain, wind, and pathogen may lead plants to onset defense response. Previous studies indicated that mechanical wounding stimulates plants to generate nitric oxide (NO) and hydrogen peroxide (H(2)O(2)). In this study, the functions of NO and H(2)O(2) after wounding in sweet potato (Ipomoea batatas cv. Tainung 57) was further analyzed. Mechanical wounding damaged cells and resulted in necrosis, but the presence of NO donors or NO scavenger might reduce or enhance the cell death caused by wounding, respectively. The amount of H(2)O(2) induced by wounding was also decreased or increased when plants were incubated with NO donors or NO scavenger, individually. These results indicate that NO may regulate H(2)O(2) generation to affect cell death. NO-induced proteins isolated from two-dimensional electrophoresis were identified to be Copper/Zinc superoxide dismutases (CuZnSODs). The activities of CuZnSODs and ascorbate peroxidase (APX) could be enhanced by NO. In addition, the expression of CuZnSOD and APX was induced by wounding via NO, and their expression was further stimulated by NO through the generation of cGMP. The influx of calcium ions and the activity of NADPH oxidase were also involved in the NO signal transduction pathway inducing APX expression. Collectively, the generation of H(2)O(2) in wounded plants might trigger cell death. Meanwhile, the production of NO induced by wounding stimulated signal transducers including cGMP, calcium ions, and H(2)O(2) to activate CuZnSOD and APX, which further decreased H(2)O(2) level and reduced the cell death caused by wounding. PMID:21833542

  7. Expression of inducible nitric oxide synthase in lungs of broiler chickens following intravenous cellulose microparticle injection.

    PubMed

    Hamal, K R; Wideman, R; Anthony, N; Erf, G F

    2008-04-01

    Intravenous microparticle (MP) injection is a patented method used to select broilers with a robust pulmonary capacity and improved resistance to pulmonary hypertension syndrome (PHS, ascites). Injected MP become entrapped in the terminal pulmonary arterioles where they elicit an increase in pulmonary arterial pressure attributable to vascular occlusion and focal thrombocyte aggregation. Within 2 to 48 h postinjection perivascular mononuclear cell aggregates begin to form around MP-occluded vessels. Nitric oxide (NO) has been shown to modulate the pulmonary arterial pressure response to MP entrapment, but a role of NO during the more chronic (2 to 48 h) focal inflammatory response has not been evaluated. In this study we determined the time-course of inducible nitric oxide synthase (iNOS) expression in the lungs of MP-injected broilers from PHS-resistant (RES) and PHS-susceptible (SUS) lines. Four-week-old broilers (10 broilers/line per time point) were injected i.v. with a minimally lethal dose of MP, and the right lung was collected at 0 h (no MP) and 2, 24, and 48 h postinjection. Immunohistochemistry revealed that macrophage infiltration increased over time in both lines and was higher in the RES line than the SUS line (P<0.0001) at all time points. Nicotinamide adenine dinucleotide phosphate diaphorase staining showed nitric oxide synthase activity around MP-occluded vessels and in the perivascular mononuclear cell aggregates. Relative iNOS expression in lung tissue was examined by 2-step reverse transcription PCR. Lines differed in relative iNOS mRNA expression only at 24 h (P<0.001; RES > SUS line). For the RES line iNOS mRNA expression increased consistently from 0 to 48 h, but for the SUS line iNOS mRNA expression increased at 2 h, decreased to baseline at 24 h, and increased again by 48 h. The decline in iNOS expression in the SUS line between 2 and 24 h coincides with the interval when most of the MP-induced mortality occurs, which suggests that NO

  8. Resveratrol Induces Hepatic Mitochondrial Biogenesis Through the Sequential Activation of Nitric Oxide and Carbon Monoxide Production

    PubMed Central

    Kim, Seul-Ki; Joe, Yeonsoo; Zheng, Min; Kim, Hyo Jeong; Yu, Jae-Kyoung; Cho, Gyeong Jae; Chang, Ki Churl; Kim, Hyoung Kyu; Han, Jin; Ryter, Stefan W.

    2014-01-01

    Abstract Aims: Nitric oxide (NO) can induce mitochondrial biogenesis in cultured cells, through increased guanosine 3′,5′-monophosphate (cGMP), and activation of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α). We sought to determine the role of NO, heme oxygenase-1 (HO-1), and its reaction product (carbon monoxide [CO]) in the induction of mitochondrial biogenesis by the natural antioxidant resveratrol. Results: S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, induced mitochondrial biogenesis in HepG2 hepatoma cells, and in vivo, through stimulation of PGC-1α. NO-induced mitochondrial biogenesis required cGMP, and was mimicked by the cGMP analogue (8-bromoguanosine 3′,5′-cyclic monophosphate [8-Br-cGMP]). Activation of mitochondrial biogenesis by SNAP required HO-1, as it could be reversed by genetic interference of HO-1; and by treatment with the HO inhibitor tin-protoporphyrin-IX (SnPP) in vitro and in vivo. Cobalt protoporphyrin (CoPP)-IX, an HO-1 inducing agent, stimulated mitochondrial biogenesis in HepG2 cells, which could be reversed by the CO scavenger hemoglobin. Application of CO, using the CO-releasing molecule-3 (CORM-3), stimulated mitochondrial biogenesis in HepG2 cells, in a cGMP-dependent manner. Both CoPP and CORM-3-induced mitochondrial biogenesis required NF-E2-related factor-2 (Nrf2) activation and phosphorylation of Akt. The natural antioxidant resveratrol induced mitochondrial biogenesis in HepG2 cells, in a manner dependent on NO biosynthesis, cGMP synthesis, Nrf2-dependent HO-1 activation, and endogenous CO production. Furthermore, resveratrol preserved mitochondrial biogenesis during lipopolysaccharides-induced hepatic inflammation in vivo. Innovation and Conclusions: The complex interplay between endogenous NO and CO production may underlie the mechanism by which natural antioxidants induce mitochondrial biogenesis. Strategies aimed at improving mitochondrial biogenesis may be used as therapeutics

  9. Tetrahydrobiopterin Deficiency and Nitric Oxide Synthase Uncoupling Contribute to Atherosclerosis Induced by Disturbed Flow

    PubMed Central

    Li, Li; Chen, Wei; Rezvan, Amir; Jo, Hanjoong; Harrison, David G.

    2011-01-01

    Objective Tetrahydrobiopterin (BH4) is a critical cofactor for Nitric Oxide (NO) synthesis by NO synthase (NOS). Recently, we demonstrated that disturbed flow produced by partial carotid ligation decreases BH4 levels in vivo. We therefore aimed to determine whether atherosclerosis induced by disturbed flow is due to BH4 deficiency and NOS uncoupling and whether increasing BH4 would prevent endothelial dysfunction, plaque inflammation and atherosclerosis. Methods and Results We produced a region of disturbed flow in ApoE−/− mice using partial carotid ligation and fed these animals a high-fat diet. This caused eNOS uncoupling as characterized by increased vascular superoxide production, altered vascular reactivity and a change in eNOS migration on low-temperature gel. These perturbations were accompanied by severe atherosclerosis, infiltration of T cells and macrophages, and an increase in cytokine production. Treatment with BH4 recoupled NOS, decreased superoxide production, imporoved endothelium-dependent vasodilatation and virtually eliminated atherosclerosis. BH4 treatment also markedly reduced vascular inflammation and improved the cytokine milieu induced by disturbed flow. Conclusions Our results highlight a key role of BH4 deficiency and NOS uncoupling in atherosclerosis induced by disturbed flow, and provide insight into the effect of modulating vascular BH4 levels on atherosclerosis and inflammation at these sites of the circulation. PMID:21512164

  10. Effect of nitric oxide on beta-glucan/indomethacin-induced septic shock.

    PubMed

    Nameda, Sachiko; Saito, Maki; Miura, Noriko N; Adachi, Yoshiyuki; Ohno, Naohito

    2005-07-01

    We have previously shown that repeated administration of nonsteroidal anti-inflammatory drugs (NSAIDs) to mice treated with beta-glucan, a biological response modifier, induced severe lethality. The lethality would be strongly related to the translocation of enterobacterial flora to the peritoneal cavity and disruption of the cytokine network. Reports suggest that nitric oxide (NO) can have an effective or detrimental role in septic shock. In the present study, we examined the effect of NO, an inflammatory mediator, on beta-glucan/indomethacin (IND)- induced septic shock by inhibiting its synthesis with N(G)-nitro-L-arginine methyl ester (L-NAME), a nonselective NO synthase (NOS) inhibitor. Nitrite concentration was used as an indicator of NO generation. Mortality in beta-glucan/IND-treated mice was increased by administering L-NAME. Numbers of bacteria in various organs of mice treated with beta-glucan/IND rose significantly within a couple of days of the administration of L-NAME. Additionally, TNF-alpha, IL-1beta, and IL-6 concentrations were enhanced in peritoneal exuded cells in culture. These results suggest a significant loss of the bactericidal activity of macrophages on the administration of a NOS inhibitor which enhanced the rate of enterobacterial invasion to the peritoneal cavity, resulting in systemic inflammatory response syndrome. The production of NO, therefore, provides a protective effect in beta-glucan/IND-induced sepsis. PMID:15997109

  11. Involvement of Syk kinase in TNF-induced nitric oxide production by airway epithelial cells

    SciTech Connect

    Ulanova, Marina . E-mail: marina.ulanova@normed.ca; Marcet-Palacios, Marcelo; Munoz, Samira; Asfaha, Samuel; Kim, Moo-Kyung; Schreiber, Alan D.; Befus, A. Dean

    2006-12-15

    We have recently found that Syk is widely expressed in lung epithelial cells (EC) and participates in {beta}1 integrin signaling. In this study, we assessed the role of Syk in regulation of NO production. Stimulation of human bronchial EC line HS-24 by TNF caused an increased expression of inducible nitric oxide synthase (iNOS). Inhibition of Syk using siRNA or piceatannol down-regulated the iNOS expression and reduced NO production. This effect occurred in EC simultaneously stimulated via {beta}1 integrins, suggesting that TNF and {beta}1 integrins provide co-stimulatory signals. Inhibition of Syk down-regulated TNF-induced p38 and p44/42 MAPK phosphorylation and nuclear translocation of p65 NF-{kappa}B. Thus, TNF-induced activation of pro-inflammatory signaling in EC leading to enhanced expression of iNOS and NO production was dependent on Syk. Syk-mediated signaling regulates NO production at least partly via activating the MAPK cascade. Understanding the role of Syk in airway EC may help in developing new therapeutic tools for inflammatory lung disorders.

  12. Endogenous nitric oxide limits cytokine-induced damage of murine lung epithelial cells.

    PubMed

    Burke-Gaffney, A; Hellewell, P G

    1997-04-01

    This study investigated whether endogenous nitric oxide (NO) limits cytokine-induced damage to the murine lung epithelial cell line LA-4. NO production was assessed as nitrite using the Griess reaction, and cell damage was assessed using ethidium homodimer-1. Cytotoxicity was first detected after a 24-h incubation with a combination of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma (cytomix). Nitrite production increased to 78.0 +/- 0.5 nmol/10(6) cells at 24 h. Coincubation of LA-4 with cytomix and NO synthase inhibitors, aminoguanidine (3-1,000 microM) and N(G)-monomethyl-L-arginine (10-1,000 microM), but not N(G)-monomethyl-D-arginine, or a soluble guanylate cyclase inhibitor, 1H-[1,2,4] oxadiazole [4,3-a] quinoxalin-1-one, reduced cytomix-induced nitrite production and increased cytotoxicity up to twofold (24 h). Removal of L-arginine from the medium increased damage; reintroduction of 1,000 microM L-arginine, but not D-arginine, reversed this. In aminoguanidine-treated cells, replacement of NO with an NO donor, S-nitrosoglutathione (30 microM), reversed, in part, the cell damage observed in aminoguanidine/cytomix-treated cells. These results suggest that endogenous NO limits cytokine-induced lung epithelial damage. PMID:9142945

  13. Nitric oxide-induced calcium release via ryanodine receptors regulates neuronal function

    PubMed Central

    Kakizawa, Sho; Yamazawa, Toshiko; Chen, Yili; Ito, Akihiro; Murayama, Takashi; Oyamada, Hideto; Kurebayashi, Nagomi; Sato, Osamu; Watanabe, Masahiko; Mori, Nozomu; Oguchi, Katsuji; Sakurai, Takashi; Takeshima, Hiroshi; Saito, Nobuhito; Iino, Masamitsu

    2012-01-01

    Mobilization of intracellular Ca2+ stores regulates a multitude of cellular functions, but the role of intracellular Ca2+ release via the ryanodine receptor (RyR) in the brain remains incompletely understood. We found that nitric oxide (NO) directly activates RyRs, which induce Ca2+ release from intracellular stores of central neurons, and thereby promote prolonged Ca2+ signalling in the brain. Reversible S-nitrosylation of type 1 RyR (RyR1) triggers this Ca2+ release. NO-induced Ca2+ release (NICR) is evoked by type 1 NO synthase-dependent NO production during neural firing, and is essential for cerebellar synaptic plasticity. NO production has also been implicated in pathological conditions including ischaemic brain injury, and our results suggest that NICR is involved in NO-induced neuronal cell death. These findings suggest that NICR via RyR1 plays a regulatory role in the physiological and pathophysiological functions of the brain. PMID:22036948

  14. Nitric oxide ameliorates zinc oxide nanoparticles-induced phytotoxicity in rice seedlings.

    PubMed

    Chen, Juan; Liu, Xiang; Wang, Chao; Yin, Shan-Shan; Li, Xiu-Ling; Hu, Wen-Jun; Simon, Martin; Shen, Zhi-Jun; Xiao, Qiang; Chu, Cheng-Cai; Peng, Xin-Xiang; Zheng, Hai-Lei

    2015-10-30

    Nitric oxide (NO) has been found to function in enhancing plant tolerance to various environmental stresses. However, role of NO in relieving zinc oxide nanoparticles (ZnO NPs)-induced phytotoxicity remains unknown. Here, sodium nitroprusside (SNP, a NO donor) was used to investigate the possible roles and the regulatory mechanisms of NO in counteracting ZnO NPs toxicity in rice seedlings. Our results showed that 10 μM SNP significantly inhibited the appearance of ZnO NP toxicity symptoms. SNP addition significantly reduced Zn accumulation, reactive oxygen species production and lipid peroxidation caused by ZnO NPs. The protective role of SNP in reducing ZnO NPs-induced oxidative damage is closely related to NO-mediated antioxidant system. A decrease in superoxide dismutase activity, as well as an increase in reduced glutathione content and peroxidase, catalase and ascorbate peroxidase activity was observed under SNP and ZnO NPs combined treatments, compared to ZnO NPs treatment alone. The relative transcript abundance of corresponding antioxidant genes exhibited a similar change. The role of NO in enhancing ZnO NPs tolerance was further confirmed by genetic analysis using a NO excess mutant (noe1) and an OsNOA1-silenced plant (noa1) of rice. Together, this study provides the first evidence indicating that NO functions in ameliorating ZnO NPs-induced phytotoxicity. PMID:25958266

  15. Spironolactone Prevents Endothelial Nitric Oxide Synthase Uncoupling and Vascular Dysfunction Induced by β-Adrenergic Overstimulation

    PubMed Central

    Victorio, Jamaira A.; Clerici, Stefano P.; Palacios, Roberto; Alonso, María J.; Vassallo, Dalton V.; Jaffe, Iris Z.; Rossoni, Luciana V.

    2016-01-01

    Sustained stimulation of β-adrenoceptors (β-ARs) and activation of renin–angiotensin–aldosterone system are common features of cardiovascular diseases with rising sympathetic activation, including essential hypertension, myocardial infarction, and heart failure. In this study, we investigated the role of AT1 receptor and mineralocorticoid receptor (MR) in the vascular alterations caused by β-AR overstimulation. β-AR overstimulation with associated cardiac hypertrophy and increased vasoconstrictor response to phenylephrine in aorta were modeled in rats by 7-day isoproterenol treatment. The increased vasoconstrictor response to phenylephrine in this model was blunted by the MR antagonist spironolactone, but not by the AT1 receptor antagonist losartan, despite the blunting of cardiac hypertrophy with both drugs. Spironolactone, but not losartan, restored NO bioavailability in association with lower endothelial nitric oxide synthase–derived superoxide production, increased endothelial nitric oxide synthase dimerization, and aortic HSP90 upregulation. MR genomic and nongenomic functions were activated in aortas from isoproterenol-treated rats. Isoproterenol did not modify plasma levels of MR ligands aldosterone and corticosterone but rather increased perivascular adipose tissue–derived corticosterone in association with increased expression of 11β-hydroxysteroid dehydrogenase type 1. The anticontractile effect of aortic perivascular adipose tissue was impaired by β-AR overstimulation and restored by MR blockade. These results suggest that activation of vascular MR signaling contributes to the vascular dysfunction induced by β-AR overstimulation associated with endothelial nitric oxide synthase uncoupling. These findings reveal an additional explanation for the protective effects of MR antagonists in cardiovascular disorders with sympathetic activation. PMID:27432866

  16. Expression of inducible nitric oxide synthase by stimulated macrophages correlates with their antihistoplasma activity.

    PubMed Central

    Lane, T E; Otero, G C; Wu-Hsieh, B A; Howard, D H

    1994-01-01

    The antihistoplasma activity of recombinant murine gamma interferon (rMuIFN-gamma)-treated macrophages of the RAW 264.7 cell line depends on the generation of nitric oxide (NO.) from L-arginine. Macrophages of the P388D1 cell line treated with rMuIFN-gamma do not produce NO. or inhibit the intracellular growth of Histoplasma capsulatum. NO. is generated by the inducible enzyme nitric oxide synthase (iNOS) formed by stimulated macrophages. Northern (RNA) blot analysis of RAW 264.7 cells revealed the expression of iNOS mRNA after exposure to rMuIFN-gamma. In contrast, rMuIFN-gamma-treated P388D1 cells did not produce detectable levels of iNOS. These data suggest that the failure of P388D1 cells to generate NO. and to restrict the intracellular growth of H. capsulatum is due to a lack of expression of iNOS following treatment with rMuIFN-gamma. Images PMID:7510670

  17. Enhanced expression of constitutive and inducible forms of nitric oxide synthase in autoimmune encephalomyelitis.

    PubMed

    Kim, S; Moon, C; Wie, M B; Kim, H; Tanuma, N; Matsumoto, Y; Shin, T

    2000-06-01

    To elucidate the role of nitric oxide synthase (NOS) in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), we analyzed the expression of constitutive neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) in the spinal cords of rats with EAE. We further examined the structural interaction between apoptotic cells and spinal cord cells including neurons and astrocytes, which are potent cell types of nitric oxide (NO) production in the brain. Western blot analysis showed that three forms of NOS significantly increased in the spinal cords of rats at the peak stage of EAE, while small amounts of these enzymes were identified in the spinal cords of rats without EAE. Immunohistochemical study showed that the expression of either nNOS or eNOS increased in the brain cells including neurons and astrocytes during the peak and recovery stages of EAE, while the expression of iNOS was found mainly in the inflammatory macrophages in the perivascular EAE lesions. Double labeling showed that apoptotic cells had intimate contacts with either neurons or astrocytes, which are major cell types to express nNOS and eNOS constitutively. Our results suggest that the three NOS may play an important role in the recovery of EAE. PMID:14612615

  18. Antiproliferative activity and apoptosis inducing effects of nitric oxide donating derivatives of evodiamine.

    PubMed

    Zhao, Nan; Tian, Kang-Tao; Cheng, Ke-Guang; Han, Tong; Hu, Xu; Li, Da-Hong; Li, Zhan-Lin; Hua, Hui-Ming

    2016-07-01

    The first series of nitric oxide donating derivatives of evodiamine were designed and prepared. NO releasing ability of all target derivatives was evaluated in BGC-823, Bel-7402 and L-02 cells. The cytotoxicity was evaluated against three human tumor cell lines (Bel-7402, A549 and BGC-823) and normal human liver cells L-02. The nitrate derivatives 11a and 11b only exhibited moderate activity and furoxan-based derivatives 13a-c, 14a and 14b showed promising activity. 13c showed good cytotoxic selectivity between tumor and normal liver cells and was further investigated for its apoptotic properties on human hepatocarcinoma Bel-7402 cells. The molecular mode of action revealed that 13c caused cell-cycle arrest at S phase and induced apoptosis in Bel-7402 cells through mitochondria-related caspase-dependent pathways. PMID:27178387

  19. Myoglobin protects the heart from inducible nitric-oxide synthase (iNOS)-mediated nitrosative stress.

    PubMed

    Gödecke, Axel; Molojavyi, Andre; Heger, Jacqueline; Flögel, Ulrich; Ding, Zhaoping; Jacoby, Christoph; Schrader, Jürgen

    2003-06-13

    The role of inducible nitric-oxide synthase (iNOS) in the pathogenesis of heart failure is still a matter of controversy. In contrast to early reports favoring a contribution of iNOS because of the negative inotropic and apoptotic potential of NO, more recent clinical and experimental data question a causative role. Here we report that transgenic mice with cardiac specific iNOS-overexpression and concomitant myoglobin-deficiency (tg-iNOS+/myo-/-) develop signs of heart failure with cardiac hypertrophy, ventricular dilatation, and interstitial fibrosis. In addition, reactivation of the fetal gene expression program typical for heart failure occurs. The structural and molecular changes are accompanied by functional depression such as reduced contractility, ejection fraction, and cardiac energetics. Our findings indicate that excessive cardiac NO formation can cause heart failure; however, under normal circumstances myoglobin constitutes the important barrier that efficiently protects the heart from nitrosative stress. PMID:12665503

  20. Cloning and Characterization of Inducible Nitric Oxide Synthase from Mouse Macrophages

    NASA Astrophysics Data System (ADS)

    Xie, Qiao-Wen; Cho, Hearn J.; Calaycay, Jimmy; Mumford, Richard A.; Swiderek, Kristine M.; Lee, Terry D.; Ding, Aihao; Troso, Tiffany; Nathan, Carl

    1992-04-01

    Nitric oxide (NO) conveys a variety of messages between cells, including signals for vasorelaxation, neurotransmission, and cytotoxicity. In some endothelial cells and neurons, a constitutive NO synthase is activated transiently by agonists that elevate intracellular calcium concentrations and promote the binding of calmodulin. In contrast, in macrophages, NO synthase activity appears slowly after exposure of the cells to cytokines and bacterial products, is sustained, and functions independently of calcium and calmodulin. A monospecific antibody was used to clone complementary DNA that encoded two isoforms of NO synthase from immunologically activated mouse macrophages. Liquid chromatography-mass spectrometry was used to confirm most of the amino acid sequence. Macrophage NO synthase differs extensively from cerebellar NO synthase. The macrophage enzyme is immunologically induced at the transcriptional level and closely resembles the enzyme in cytokine-treated tumor cells and inflammatory neutrophils.

  1. Bilirubin prevents acute DSS-induced colitis by inhibiting leukocyte infiltration and suppressing upregulation of inducible nitric oxide synthase.

    PubMed

    Zucker, Stephen D; Vogel, Megan E; Kindel, Tammy L; Smith, Darcey L H; Idelman, Gila; Avissar, Uri; Kakarlapudi, Ganesh; Masnovi, Michelle E

    2015-11-15

    Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression. PMID:26381705

  2. Stimulation of Inducible Nitric Oxide by Hepatitis B Virus Transactivator Protein HBx Requires MTA1 Coregulator*

    PubMed Central

    Bui-Nguyen, Tri M.; Pakala, Suresh B.; Sirigiri, Divijendranatha Reddy; Martin, Emil; Murad, Ferid; Kumar, Rakesh

    2010-01-01

    Nitric oxide has been implicated in the pathogenesis of inflammatory disorders, including hepatitis B virus-associated hepatocellular carcinoma. Transactivator protein HBx, a major regulator of cellular responses of hepatitis B virus, is known to induce the expression of MTA1 (metastasis-associated protein 1) coregulator via NF-κB signaling in hepatic cells. However, the underlying mechanism of HBx regulation of the inducible nitric-oxide synthase (iNOS) pathway remains unknown. Here we provide evidence that MTA1 is a positive regulator of iNOS transcription and plays a mechanistic role in HBx stimulation of iNOS expression and activity. We found that the HBx-MTA1 complex is recruited onto the human iNOS promoter in an NF-κB-dependent manner. Pharmacological inhibition of the NF-κB signaling prevented the ability of HBx to stimulate the transcription, the expression, and the activity of iNOS; nevertheless, these effects could be substantially rescued by MTA1 dysregulation. We further discovered that HBx-mediated stimulation of MTA1 is paralleled by the suppression of miR-661, a member of the small noncoding RNAs, recently shown to target MTA1. We observed that miR-661 controls of MTA1 expression contributed to the expression and activity of iNOS in HBx-expressing HepG2 cells. Accordingly, depletion of MTA1 by either miR-661 or siRNA in HBx-expressing cells severely impaired the ability of HBx to modulate the endogenous levels of iNOS and nitrite production. Together, these findings reveal an inherent role of MTA1 in HBx regulation of iNOS expression and consequently its function in the liver cancer cells. PMID:20022949

  3. Ubiquitination of inducible nitric oxide synthase is required for its degradation

    PubMed Central

    Kolodziejski, Pawel J.; Musial, Aleksandra; Koo, Ja-Seok; Eissa, N. Tony

    2002-01-01

    Inducible nitric oxide synthase (iNOS) is responsible for nitric oxide (NO) synthesis from l-arginine in response to inflammatory mediators. We have previously shown that iNOS is degraded through the 26S proteasome. Targeting of proteins for proteasomal degradation may or may not require their covalent linkage to multiubiquitin chains (ubiquitination). In addition, ubiquitination of a protein can serve functions other than signaling proteolysis. In this context, it is not known whether iNOS is subject to ubiquitination or whether ubiquitination is required for its degradation. In this study, we show that iNOS, expressed in HEK293 cells or induced in primary bronchial epithelial cells, A549 cells, or murine macrophages, is subject to ubiquitination. To investigate whether iNOS ubiquitination is required for its degradation, HEK293T cells were cotransfected with plasmids containing cDNAs of human iNOS and of the dominant negative ubiquitin mutant K48R. Disruption of ubiquitination by K48R ubiquitin resulted in inhibition of iNOS degradation. ts20 is a mutant cell line that contains a thermolabile ubiquitin-activating enzyme (E1) that is inactivated at elevated temperature, preventing ubiquitination. Incubation of ts20 cells, stably expressing human iNOS, at the nonpermissive temperature (40°C) resulted in inhibition of iNOS degradation and marked accumulation of iNOS. These studies indicate that iNOS is subject to ubiquitination and that ubiquitination is required for its degradation. PMID:12221289

  4. Higher Activity of the Inducible Nitric Oxide Synthase Contributes to Very Early Onset Inflammatory Bowel Disease

    PubMed Central

    Dhillon, Sandeep S; Mastropaolo, Lucas A; Murchie, Ryan; Griffiths, Christopher; Thöni, Cornelia; Elkadri, Abdul; Xu, Wei; Mack, Amanda; Walters, Thomas; Guo, Conghui; Mack, David; Huynh, Hien; Baksh, Shairaz; Silverberg, Mark S; Brumell, John H; Snapper, Scott B; Muise, Aleixo M

    2014-01-01

    OBJECTIVES: The NOS2 gene encodes for the inducible nitric oxide synthase (iNOS), responsible for nitric oxide (NO) production, which contributes to antimicrobial and antipathogenic activities. Higher levels of both iNOS and NO-induced damage have been observed in inflammatory bowel disease (IBD) patients. NOS2 may have a role in a specific subset of IBD patients with severe and/or extensive colitis. Therefore, the aim of this study is to examine the role of NOS2 in such a subset, very early onset IBD (VEO-IBD). METHODS: Seventeen tag single nucleotide polymorphisms (SNPs) in the NOS2 gene were successfully genotyped in VEO-IBD patients. Genetic associations were replicated in an independent VEO-IBD cohort. Functional analysis for iNOS activity was performed on the most significantly associated functional variant. RESULTS: The NOS2 rs2297518 SNP was found to be associated in VEO-IBD in two independent cohorts. Upon combined analysis, a coding variant (S608L) showed the strongest association with VEO-IBD (Pcombined=1.13 × 10−6, OR (odds ratio)=3.398 (95% CI (confidence interval) 2.02–5.717)) as well as associations with VEO-Crohn's disease and VEO-ulcerative colitis (UC). This variant also showed an association with UC diagnosed between 11 and 17 years of age but not with adult-onset IBD (>17 years). B-cell lymphoblastoid cell lines genotyped for the risk variant as well as Henle-407 cells transfected with a plasmid construct with the risk variant showed higher NO production. Colonic biopsies of VEO-IBD patients showed higher immunohistochemical staining of nitrotyrosine, indicating more nitrosative stress and tissue damage. CONCLUSIONS: These studies suggest the importance of iNOS in genetic susceptibility to younger IBD presentation due to higher NO production. PMID:24430113

  5. Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

    SciTech Connect

    Yoshigai, Emi; Machida, Toru; Okuyama, Tetsuya; Mori, Masatoshi; Murase, Hiromitsu; Yamanishi, Ryota; Okumura, Tadayoshi; Ikeya, Yukinobu; Nishino, Hoyoku; Nishizawa, Mikio

    2013-09-13

    Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases.

  6. Nitric-oxide-induced necrosis and apoptosis in PC12 cells mediated by mitochondria.

    PubMed

    Bal-Price, A; Brown, G C

    2000-10-01

    Nitric oxide (NO) can trigger either necrotic or apoptotic cell death. We have used PC12 cells to investigate the extent to which NO-induced cell death is mediated by mitochondria. Addition of NO donors, 1 mM S-nitroso-N-acetyl-DL-penicillamine (SNAP) or 1 mM diethylenetriamine-NO adduct (NOC-18), to PC12 cells resulted in a steady-state level of 1-3 microM: NO, rapid and almost complete inhibition of cellular respiration (within 1 min), and a rapid decrease in mitochondrial membrane potential within the cells. A 24-h incubation of PC12 cells with NO donors (SNAP or NOC-18) or specific inhibitors of mitochondrial respiration (myxothiazol, rotenone, or azide), in the absence of glucose, caused total ATP depletion and resulted in 80-100% necrosis. The presence of glucose almost completely prevented the decrease in ATP level and the increase in necrosis induced by the NO donors or mitochondrial inhibitors, suggesting that the NO-induced necrosis in the absence of glucose was due to the inhibition of mitochondrial respiration and subsequent ATP depletion. However, in the presence of glucose, NO donors and mitochondrial inhibitors induced apoptosis of PC12 cells as determined by nuclear morphology. The presence of apoptotic cells was prevented completely by benzyloxycarbonyl-Val-Ala-fluoromethyl ketone (a nonspecific caspase inhibitor), indicating that apoptosis was mediated by caspase activation. Indeed, both NO donors and mitochondrial inhibitors in PC12 cells caused the activation of caspase-3- and caspase-3-processing-like proteases. Caspase-1 activity was not activated. Cyclosporin A (an inhibitor of the mitochondrial permeability transition pore) decreased the activity of caspase-3- and caspase-3-processing-like proteases after treatment with NO donors, but was not effective in the case of the mitochondrial inhibitors. The activation of caspases was accompanied by the release of cytochrome c from mitochondria into the cytosol, which was partially prevented by

  7. YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

    SciTech Connect

    Hwang, Tsong-Long; Tang, Ming-Chi; Kuo, Liang-Mou; Chang, Wen-De; Chung, Pei-Jen; Chang, Ya-Wen; Fang, Yao-Ching

    2012-04-15

    Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E{sub 1} (a stable PGE{sub 2} analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE{sub 1}- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE{sub 1} significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE{sub 1}-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE{sub 1} also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE{sub 1}-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway. Highlights: ► YC-1 potentiated PGE1-induced iNOS expression in alveolar macrophages. ► The combination of YC-1 and PGE1 increased CREB but not NFκB activation.

  8. Trimethyltin-induced apoptosis is associated with upregulation of inducible nitric oxide synthase and Bax in a hippocampal cell line

    SciTech Connect

    Zhang, L.; Li, L.; Prabhakaran, K.; Borowitz, J.L.; Isom, G.E. . E-mail: geisom@purdue.edu

    2006-10-01

    Trimethyltin (TMT) produces selective neuronal degeneration in the central nervous system (CNS), in which the hippocampus is the most sensitive area. Since previous studies have been conducted in either non-neural cells or mixed primary cultures, an immortalized hippocampal neuronal cell line (HT-22 cell) was used to assess the mechanism and mode of death produced by TMT. The compound produced a time- and concentration-dependent apoptotic death that was caspase-mediated. Excessive generation of reactive oxygen species (ROS) and subsequent reduction of mitochondrial membrane potential ({delta}{psi}{sub m}) were involved in the cytotoxicity{sub .} Scavenging of ROS by a free radical trapping agent or inhibition of the mitochondrial permeability transition (MPT) pore significantly reduced cell death. Additionally, TMT increased expression of inducible nitric oxide synthase (iNOS) by activation of the redox-sensitive transcription factor NF{kappa}B. Pharmacologic inhibition studies showed that the iNOS-mediated NO generation increased expression of Bax and then mitochondrial-mediated apoptosis. It was concluded that excessive ROS generation initiated the apoptotic cell death by upregulating iNOS followed by increased Bax expression which then led to loss of {delta}{psi}{sub m} and caspase-executed cell death. This study is the first to report in a neuronal cell model that TMT stimulates induction of iNOS, which then increases cellular levels of reactive nitrogen species (RNS) to initiate apoptotic death.

  9. Nitric oxide is involved in phosphorus deficiency-induced cluster root development and citrate exudation in white lupin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin (Lupinus albus) forms specialized cluster roots characterized by exudation of organic anions under phosphorus (P) deficiency. Here, we evaluated the role of nitric oxide (NO) in P deficiency-induced cluster-root formation and citrate exudation in white lupin. Plants were treated with NO ...

  10. Hybrid inhibitor of peripheral cannabinoid-1 receptors and inducible nitric oxide synthase mitigates liver fibrosis

    PubMed Central

    Liu, Ziyi; Cao, Zongxian; Jourdan, Tony; Erdelyi, Katalin; Godlewski, Grzegorz; Szanda, Gergő; Liu, Jie; Park, Joshua K.; Mukhopadhyay, Bani; Rosenberg, Avi Z.; Liow, Jeih-San; Lorenz, Robin G.; Pacher, Pal; Innis, Robert B.; Kunos, George

    2016-01-01

    Liver fibrosis, a consequence of chronic liver injury and a way station to cirrhosis and hepatocellular carcinoma, lacks effective treatment. Endocannabinoids acting via cannabinoid-1 receptors (CB1R) induce profibrotic gene expression and promote pathologies that predispose to liver fibrosis. CB1R antagonists produce opposite effects, but their therapeutic development was halted due to neuropsychiatric side effects. Inducible nitric oxide synthase (iNOS) also promotes liver fibrosis and its underlying pathologies, but iNOS inhibitors tested to date showed limited therapeutic efficacy in inflammatory diseases. Here, we introduce a peripherally restricted, orally bioavailable CB1R antagonist, which accumulates in liver to release an iNOS inhibitory leaving group. In mouse models of fibrosis induced by CCl4 or bile duct ligation, the hybrid CB1R/iNOS antagonist surpassed the antifibrotic efficacy of the CB1R antagonist rimonabant or the iNOS inhibitor 1400W, without inducing anxiety-like behaviors or CB1R occupancy in the CNS. The hybrid inhibitor also targeted CB1R-independent, iNOS-mediated profibrotic pathways, including increased PDGF, Nlrp3/Asc3, and integrin αvβ6 signaling, as judged by its ability to inhibit these pathways in cnr1−/− but not in nos2−/− mice. Additionally, it was able to slow fibrosis progression and to attenuate established fibrosis. Thus, dual-target peripheral CB1R/iNOS antagonists have therapeutic potential in liver fibrosis. PMID:27525312

  11. Arsenite induces endothelial cytotoxicity by down-regulation of vascular endothelial nitric oxide synthase

    SciTech Connect

    Tsou, T.-C. . E-mail: tctsou@nhri.org.tw; Tsai, F.-Y.; Hsieh, Y.-W.; Li, L.-A.; Yeh, S.C; Chang, L.W.

    2005-11-01

    Epidemiological studies have demonstrated a high association of inorganic arsenic exposure with vascular diseases. Recent research has also linked this vascular damage to impairment of endothelial nitric oxide synthase (eNOS) function by arsenic exposure. However, the role of eNOS in regulating the arsenite-induced vascular dysfunction still remains to be clarified. In our present study, we investigated the effect of arsenite on Akt1 and eNOS and its involvement in cytotoxicity of vascular endothelial cells. Our study demonstrated that arsenite decreased the protein levels of both Akt1 and eNOS accompanied with increased levels of ubiquitination of total cell lysates. We found that inhibition of the ubiquitin-proteasome pathway by MG-132 could partially protect Akt1 and eNOS from degradation by arsenite together with a proportional protection from the arsenite-induced cytoxicity. Moreover, up-regulation of eNOS protein expression significantly attenuated the arsenite-induced cytotoxicity and eNOS activity could be significantly inhibited after incubation with arsenite for 24 h in a cell-free system. Our study indicated that endothelial eNOS activity could be attenuated by arsenite via the ubiquitin-proteasome-mediated degradation of Akt1/eNOS as well as via direct inhibition of eNOS activity. Our study also demonstrated that eNOS actually played a protective role in arsenite-induced cytoxicity. These observations supported the hypothesis that the impairment of eNOS function by arsenite is one of the mechanisms leading to vascular changes and diseases.

  12. Human Immunodeficiency Virus Type 1 (HIV-1) Tat Induces Nitric-oxide Synthase in Human Astroglia*

    PubMed Central

    Liu, Xiaojuan; Jana, Malabendu; Dasgupta, Subhajit; Koka, Sreenivas; He, Jun; Wood, Charles; Pahan, Kalipada

    2007-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection is known to cause neuronal injury and dementia in a significant proportion of patients. However, the mechanism by which HIV-1 mediates its deleterious effects in the brain is poorly defined. The present study was undertaken to investigate the effect of the HIV-1 tat gene on the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astroglia. Expression of the tat gene as RSV-tat but not that of the CAT gene as RSV-CAT in U373MG astroglial cells led to the induction of NO production and the expression of iNOS protein and mRNA. Induction of NO production by recombinant HIV-1 Tat protein and inhibition of RSV-tat-induced NO production by anti-Tat antibodies suggest that RSV-tat-induced production of NO is dependent on Tat and that Tat is secreted from RSV-tat-transfected astroglia. Similar to U373MG astroglial cells, RSV-tat also induced the production of NO in human primary astroglia. The induction of human iNOS promoter-derived luciferase activity by the expression of RSV-tat suggests that RSV-tat induces the transcription of iNOS. To understand the mechanism of induction of iNOS, we investigated the role of NF-κB and C/EBPβ, transcription factors responsible for the induction of iNOS. Activation of NF-κB as well as C/EBPβ by RSV-tat, stimulation of RSV-tat-induced production of NO by the wild type of p65 and C/EBPβ, and inhibition of RSV-tat-induced production of NO by Δp65, a dominant-negative mutant of p65, and ΔC/EBPβ, a dominant-negative mutant of C/EBPβ, suggest that RSV-tat induces iNOS through the activation of NF-κB and C/EBPβ. In addition, we show that extracellular signal-regulated kinase (ERK) but not that p38 mitogen-activated protein kinase (MAPK) is involved in RSV-tat induced production of NO. Interestingly, PD98059, an inhibitor of the ERK pathway, and ΔERK2, a dominant-negative mutant of ERK2, inhibited RSV-tat-induced production of NO

  13. Endothelium negatively modulates the vascular relaxation induced by nitric oxide donor, due to uncoupling NO synthase.

    PubMed

    Bonaventura, Daniella; Lunardi, Claure N; Rodrigues, Gerson J; Neto, Mário A; Vercesi, Juliana A; de Lima, Renata G; da Silva, Roberto S; Bendhack, Lusiane M

    2009-10-01

    Nitrosyl ruthenium complexes have been characterized as nitric oxide (NO) donors that induce relaxation in the denuded rat aorta. There are some differences in their vascular relaxation mechanisms compared with sodium nitroprusside. This study investigates whether the endothelium could interfere with the [Ru(terpy)(bdq)NO](3+)-TERPY-induced vascular relaxation, by analyzing the maximal relaxation (Emax) and potency (pD(2)) of TERPY. Vascular reactivity experiments showed that the endothelium negatively modulates (pD(2): 6.17+/-0.07) the TERPY relaxation in intact rat aortic rings compared with the denuded rat aorta (pD(2): 6.65+/-0.07). This effect is abolished by a non-selective NO-synthase (NOS) inhibitor L-NAME (pD(2): 6.46+/-0.10), by the superoxide anion (O(2)(-)) scavenger TIRON (pD(2): 6.49+/-0.08), and by an NOS cofactor BH(4) (pD(2): 6.80+/-0.10). The selective dye for O(2)(-) (DHE) shows that TERPY enhances O(2)(-) concentration in isolated endothelial cells (intensity of fluorescence (IF):11258.00+/-317.75) compared with the basal concentration (IF: 7760.67+/-381.50), and this enhancement is blocked by L-NAME (IF: 8892.33+/-1074.41). Similar results were observed in vascular smooth muscle cells (concentration of superoxide after TERPY: 2.63+/-0.17% and after TERPY+L-NAME: -4.63+/-0.14%). Considering that TERPY could induce uncoupling NOS, thus producing O(2)(-), we have also investigated the involvement of prostanoids in the negative modulation of the endothelium. The non-selective cyclooxygenase (COX) inhibitor indomethacin and the selective tromboxane (TXA(2)) receptor antagonist SQ29548 reduce the effect of the endothelium on TERPY relaxation (pD(2) INDO: 6.80+/-0.17 and SQ29548: 6.85+/-0.15, respectively). However, a selective prostaglandin F(2alpha) receptor antagonist (AH6809) does not change the endothelium effect. Moreover, TERPY enhances the concentration of TXA(2) stable metabolite (TXB(2)), but this effect is blocked by L-NAME and TIRON. The

  14. Nitric oxide mitigates arsenic-induced oxidative stress and genotoxicity in Vicia faba L.

    PubMed

    Shukla, Pratiksha; Singh, A K

    2015-09-01

    The protective effects of nitric oxide (NO) against arsenic (As)-induced structural disturbances in Vicia faba have been investigated. As treatment (0.25, 0.50, and 1 mM) resulted in a declined growth of V. faba seedlings. Arsenic treatment stimulates the activity of SOD and CAT while the activities of APX and GST content were decreased. The oxidative stress markers such as superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) contents were enhanced by As. Overall results revealed that significant accumulation of As suppressed growth, photosynthesis, antioxidant enzymes (SOD, CAT, APX, and GST activity), mitotic index, and induction of different chromosomal abnormalities, hence led to oxidative stress. The concentration of SNP (0.02 mM) was very effective in counteracting the adverse effect of As toxicity. These abnormalities use partially or fully reversed by a simultaneous application of As and NO donor and sodium nitroprusside and has an ameliorating effect against As-induced oxidative stress and genotoxicity in V. faba roots. PMID:25943507

  15. The NADPH oxidase inhibitor apocynin induces nitric oxide synthesis via oxidative stress

    SciTech Connect

    Riganti, Chiara

    2008-05-01

    We have recently shown that apocynin elicits an oxidative stress in N11 mouse glial cells and other cell types. Here we report that apocynin increased the accumulation of nitrite, the stable derivative of nitric oxide (NO), in the extracellular medium of N11 cell cultures, and the NO synthase (NOS) activity in cell lysates. The increased synthesis of NO was associated with increased expression of inducible NOS (iNOS) mRNA, increased nuclear translocation of the redox-sensitive transcription factor NF-{kappa}B and decreased intracellular level of its inhibitor IkB{alpha}. These effects, accompanied by increased production of H{sub 2}O{sub 2}, were very similar to those observed after incubation with bacterial lipopolysaccharide (LPS) and were inhibited by catalase. These results suggest that apocynin, similarly to LPS, induces increased NO synthesis by eliciting a generation of reactive oxygen species (ROS), which in turn causes NF-{kappa}B activation and increased expression of iNOS. Therefore, the increased bioavailability of NO reported in the literature after in vivo or in vitro treatments with apocynin might depend, at least partly, on the drug-elicited induction of iNOS, and not only on the inhibition of NADPH oxidase and the subsequent decreased scavenging of NO by oxidase-derived ROS, as it is often supposed.

  16. Autoregulation of Inducible Nitric Oxide Synthase Expression by RNA Interference Provides Neuroprotection in Neonatal Rats

    PubMed Central

    Wang, Zhi; Feng, Chenzhuo; Zhao, Huijuan; Ren, Xiaoyan; Peng, Shuling; Zuo, Zhiyi

    2015-01-01

    We have shown that autoregulation of gene expression by RNA interference is achievable in cell cultures. To determine whether this novel concept could be used to produce neuroprotection under in vivo condition, postnatal day (PND) 3 rats received intracerebroventricular injection of lentivirus that carried or did not carry code for short hairpin RNA (shRNA) of inducible nitric oxide synthase (iNOS). The expression of this shRNA was controlled by an iNOS promoter (piNOS-shRNA) or cytomegalovirus promoter (pCMV-shRNA). The rats were subjected to brain hypoxia-ischemia at PND7. Ischemic brain tissues had increased iNOS expression. This increase was attenuated by virus carrying piNOS-shRNA. Virus carrying pCMV-shRNA reduced iNOS to a level that was lower than control. Brain tissue loss and functional impairment after the hypoxia-ischemia were attenuated by the virus carrying piNOS-shRNA but not by pCMV-shRNA. Our results provide proof-of-concept evidence that autoregulation of iNOS expression by RNA interference induces neuroprotection in vivo and that appropriate regulation of gene expression is important. PMID:25767617

  17. Tartary buckwheat on nitric oxide-induced inflammation in RAW264.7 macrophage cells.

    PubMed

    Choi, Soo Yeon; Choi, Ji Yeon; Lee, Jeong Min; Lee, Sanghyun; Cho, Eun Ju

    2015-08-01

    We investigated the effects of tartary buckwheat (TB, Fagopyrum tataricum) on the production of pro-inflammatory mediators in lipopolysaccharide (LPS)- and interferon (IFN)-γ-stimulated RAW264.7 cells. We evaluated the anti-inflammatory effects of TB against the LPS- and IFN-γ-stimulated inflammatory response in RAW264.7 macrophage cells. We fractionated TB to obtain 4 fractions including the n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions. In addition, rutin was isolated and identified from the EtOAc fraction. The 4 fractions and rutin effectively inhibited the production of reactive oxygen species, nitric oxide (NO), and interleukin-6. In addition, the mRNA expression levels of pro-inflammatory factors including nuclear factor kappa B, cyclooxygenase-2, and inducible NO synthase were down-regulated in LPS- and IFN-γ-stimulated RAW264.7 cells following treatment with the 4 fractions and rutin. The present study suggests that TB could induce anti-inflammation by regulating the expression of inflammatory mediators. PMID:26134972

  18. Hypoxia inducible factor-1α accumulation in steatotic liver preservation: Role of nitric oxide

    PubMed Central

    Zaouali, Mohamed Amine; Mosbah, Ismail Ben; Boncompagni, Eleonora; Abdennebi, Hassen Ben; Mitjavila, Maria Teresa; Bartrons, Ramon; Freitas, Isabel; Rimola, Antoni; Roselló-Catafau, Joan

    2010-01-01

    AIM: To examine the relevance of hypoxia inducible factor (HIF-1) and nitric oxide (NO) on the preservation of fatty liver against cold ischemia-reperfusion injury (IRI). METHODS: We used an isolated perfused rat liver model and we evaluated HIF-1α in steatotic and non-steatotic livers preserved for 24 h at 4°C in University of Wisconsin and IGL-1 solutions, and then subjected to 2 h of normothermic reperfusion. After normoxic reperfusion, liver enzymes, bile production, bromosulfophthalein clearance, as well as HIF-1α and NO [endothelial NO synthase (eNOS) activity and nitrites/nitrates] were also measured. Other factors associated with the higher susceptibility of steatotic livers to IRI, such as mitochondrial damage and vascular resistance were evaluated. RESULTS: A significant increase in HIF-1α was found in steatotic and non-steatotic livers preserved in IGL-1 after cold storage. Livers preserved in IGL-1 showed a significant attenuation of liver injury and improvement in liver function parameters. These benefits were enhanced by the addition of trimetazidine (an anti-ischemic drug), which induces NO and eNOS activation, to IGL-1 solution. In normoxic reperfusion, the presence of NO favors HIF-1α accumulation, promoting also the activation of other cytoprotective genes, such as heme-oxygenase-1. CONCLUSION: We found evidence for the role of the HIF-1α/NO system in fatty liver preservation, especially when IGL-1 solution is used. PMID:20653058

  19. Prolonged nitric oxide treatment induces tau aggregation in SH-SY5Y cells.

    PubMed

    Takahashi, Muneaki; Chin, Yo; Nonaka, Takashi; Hasegawa, Masato; Watanabe, Nobuo; Arai, Takao

    2012-02-21

    Presence of cytoplasmic tau aggregates is a hallmark of brains in patients with tauopathies such as Alzheimer's disease. However, the mechanism underlying formation of these insoluble tau aggregates remains elusive. In this study, we investigated the impact of prolonged nitric oxide (NO) exposure on neuronal SH-SY5Y cells overexpressing human tau. Treatment with the NO donor DETA NONOate for up to 48h resulted in an increase in S-nitrosation of cellular proteins, inactivation of proteasome, and impairment of respiration. Western blot analysis of Triton X-soluble fractions of NO-treated cells revealed that persistent NO treatment increased heterogeneity in tau molecule size, as a result of dephosphorylation, and induced the formation of sodium dodecyl sulfate (SDS)-stable oligomeric tau aggregates, stabilized by disulfide bonds. Moreover, further NO treatment induced the formation of SDS-stable insoluble tau mega-aggregates that were composed of dephosphorylated full-length tau molecules and other proteins, and were stabilized through disulfide bonds. Evaluation of the role of these tau aggregates as potential seeds for tau fibrillization and elucidation of their formation mechanism in our model, could lead to better understanding of the pathogenesis of tauopathies. PMID:22249117

  20. Carotid body chemosensory excitation induced by nitric oxide: involvement of oxidative metabolism.

    PubMed

    Mosqueira, Matias; Iturriaga, Rodrigo

    2002-08-01

    Nitric oxide (NO) produces a dual effect on carotid body (CB) oxygen chemoreception. At low concentration, NO inhibits chemosensory response to hypoxia, while in normoxia, medium and high [NO] increases the frequency of carotid chemosensory discharges (f(x)). Since NO and peroxynitrite inhibit mitochondrial respiration, it is plausible that the NO-induced excitation may depend on the mitochondrial oxidative metabolism. To test this hypothesis, we studied the effects of oligomycin, FCCP and antimycin A that produce selective blockade of hypoxic and NaCN-induced chemosensory responses, leaving nicotinic response less affected. CBs excised from pentobarbitone-anaesthetised cats were perfused in vitro with Tyrode (P(O(2)) approximately 125 Torr, pH 7.40 at 38 degrees C). Hypoxia (P(O(2)) approximately equal 30 Torr), NaCN and nicotine (1-100 microg) and S-nitroso-N-acetylpenicillamide (SNAP, 300-600 microg) increased f(x). Oligomycin (12.5-25 microg), antimycin A (10 microg) and FCCP (5 microM) transiently increased f(x). Subsequently, chemosensory responses to hypoxia, NaCN and SNAP were reduced or abolished, while the response to nicotine was less affected. The electron donor system tetramethyl-p-phenylene diamide and ascorbate that bypasses the electron chain blockade produced by antimycin A, restores the excitatory responses to NaCN and SNAP. Present results suggest that the chemoexcitatory effect of NO depends on the integrity of mitochondrial metabolism. PMID:12126919

  1. In vivo pharmacological evaluation of two novel type II (inducible) nitric oxide synthase inhibitors.

    PubMed

    Tracey, W R; Nakane, M; Basha, F; Carter, G

    1995-05-01

    Selective type II (inducible) nitric oxide synthase (NOS) inhibitors have several potential therapeutic applications, including treatment of sepsis, diabetes, and autoimmune diseases. The ability of two novel, selective inhibitors of type II NOS, S-ethylisothiourea (EIT) and 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT), to inhibit type II NOS function in vivo was studied in lipopolysaccharide (LPS) treated rats. Type II NOS activity was assessed by measuring changes in plasma nitrite and nitrate concentrations ([NOx]). Both EIT and AMT elicited a dose-dependent and > 95% inhibition of the LPS-induced increase in plasma [NOx]. The ED50 values for EIT and AMT were 0.4 and 0.2 mg/kg, respectively. In addition, the administration of LPS and either NOS inhibitor resulted in a dose-dependent increase in animal mortality; neither compound was lethal when administered alone. Pretreatment with L-arginine (but not D-arginine) prevented the mortality, while not affecting the type II NOS-dependent NO production, suggesting the toxicity may be due to inhibition of one of the other NOS isoforms (endothelial or neuronal). Thus, although EIT and AMT are potent inhibitors of type II NOS function in vivo, type II NOS inhibitors of even greater selectivity may need to be developed for therapeutic applications. PMID:7585335

  2. Nitric oxide and flavonoids are systemically induced by UV-B in maize leaves.

    PubMed

    Tossi, Vanesa; Lombardo, Cristina; Cassia, Raúl; Lamattina, Lorenzo

    2012-09-01

    Flavonoids are UV-B absorbing compounds whose concentration, increase in plant cells stimulated by UV-B irradiation. In this work, we characterized the systemic accumulation of flavonoids in maize seedlings irradiated with 3.3 W m(-2) UV-B. Results indicate that both nitric oxide (NO) and flavonoids are systemically induced in UV-B-irradiated maize seedlings. Maize leaves pre-treated with the specific NO scavenger cPTIO, do not accumulate NO and flavonoids in response to UV-B. Whereas NO and flavonoids are accumulated in the mesophyll cells near to the leaf side receiving the UV-B irradiation, they are distributed in all tissues displaying the systemic response. Flavonoids and NO co-localize in UV-B irradiated maize leaves analyzed by images from epifluorescence microscopy. Chalcone synthase (CHS) and chalcone isomerase (CHI) genes are involved in the flavonoid biosynthetic pathway and their expression is systemically induced by UV-B in a NO dependent pathway. Finally, a functional approach demonstrates that maize leaves expressing the systemic response to UV-B show low cellular damage measured as ion leakage when they are challenged by a second round of irradiation. PMID:22794923

  3. Prenatal stress induces alterations in cerebellar nitric oxide that are correlated with deficits in spatial memory in rat's offspring.

    PubMed

    Maur, Damián G; Romero, Carolina B; Burdet, Berenice; Palumbo, María L; Zorrilla-Zubilete, María A

    2012-12-01

    Prenatal stress (PS) has been linked to abnormal cognitive, behavioral and psychosocial outcomes in both animals and humans. Since PS has been shown to induce a cerebellar cytoarchitectural disarrangement and cerebellar abnormalities that have been linked to an impairment of behavioral functions, the aim of the present work was to investigate whether the exposure to PS in a period in which the cerebellum is still immature can induce behavioral deficits in the adult and whether this alterations are correlated with changes in nitric oxide (NO) and cellular oxidative mechanisms in offspring's cerebellum. Our results show impairments in spatial memory and territory discrimination in PS adult rats. PS offspring also displayed alterations in cerebellar nitric oxide synthase (NOS) expression and activity. Moreover, a correlation between spatial memory deficits and the increase in NOS activity was found. The results found here may point to a role of cerebellar NO in the behavioral alterations induced by stress during early development stages. PMID:23022609

  4. Nitric oxide mediates lung injury induced by ischemia-reperfusion in rats.

    PubMed

    Kao, Shang Jyh; Peng, Tai-Chu; Lee, Ru Ping; Hsu, Kang; Chen, Chao-Fuh; Hung, Yu-Kuen; Wang, David; Chen, Hsing I

    2003-01-01

    Nitric oxide (NO) has been reported to play a role in lung injury (LI) induced by ischemia-reperfusion (I/R). However, controversy exists as to the potential beneficial or detrimental effect of NO. In the present study, an in situ, perfused rat lung model was used to study the possible role of NO in the LI induced by I/R. The filtration coefficient (Kfc), lung weight gain (LWG), protein concentration in the bronchoalveolar lavage (PCBAL), and pulmonary arterial pressure (PAP) were measured to evaluate the degree of pulmonary hypertension and LI. I/R resulted in increased Kfc, LWG, and PCBAL. These changes were exacerbated by inhalation of NO (20-30 ppm) or 4 mM L-arginine, an NO precursor. The permeability increase and LI caused by I/R could be blocked by exposure to 5 mM N omega-nitro-L-arginine methyl ester (L-NAME; a nonspecific NO synthase inhibitor), and this protective effect of L-NAME was reversed with NO inhalation. Inhaled NO prevented the increase in PAP caused by I/R, while L-arginine had no such effect. L-NAME tended to diminish the I/R-induced elevation in PAP, but the suppression was not statistically significant when compared to the values in the I/R group. These results indicate that I/R increases Kfc and promotes alveolar edema by stimulating endogenous NO synthesis. Exogenous NO, either generated from L-arginine or delivered into the airway, is apparently also injurious to the lung following I/R. PMID:12566987

  5. Pathogenesis of influenza virus-induced pneumonia: involvement of both nitric oxide and oxygen radicals.

    PubMed Central

    Akaike, T; Noguchi, Y; Ijiri, S; Setoguchi, K; Suga, M; Zheng, Y M; Dietzschold, B; Maeda, H

    1996-01-01

    The role of nitric oxide (NO) in the pathogenesis of influenza virus-induced pneumonia in mice was investigated. Experimental influenza virus pneumonia was produced with influenza virus A/Kumamoto/Y5/67(H2N2). Both the enzyme activity of NO synthase (NOS) and mRNA expression of the inducible NOS were greatly increased in the mouse lungs; increases were mediated by interferon gamma. Excessive production of NO in the virus-infected lung was studied further by using electron spin resonance (ESR) spectroscopy. In vivo spin trapping with dithiocarbamate-iron complexes indicated that a significant amount of NO was generated in the virus-infected lung. Furthermore, an NO-hemoglobin ESR signal appeared in the virus-infected lung, and formation of NO-hemoglobin was significantly increased by treatment with superoxide dismutase and was inhibited by N(omega)-monomethyl-L-arginine (L-NMMA) administration. Immunohistochemistry with a specific anti-nitrotyrosine antibody showed intense staining of alveolar phagocytic cells such as macrophages and neutrophils and of intraalveolar exudate in the virus-infected lung. These results strongly suggest formation of peroxynitrite in the lung through the reaction of NO with O2-, which is generated by alveolar phagocytic cells and xanthine oxidase. In addition, administration of L-NMMA resulted in significant improvement in the survival rate of virus-infected mice without appreciable suppression of their antiviral defenses. On the basis of these data, we conclude that NO together with O2- which forms more reactive peroxynitrite may be the most important pathogenic factors in influenza virus-induced pneumonia in mice. Images Fig. 1 Fig. 5 PMID:8637894

  6. Roles of thioredoxin in nitric oxide-dependent preconditioning-induced tolerance against MPTP neurotoxin

    SciTech Connect

    Chiueh, C.C. . E-mail: chiueh@tmu.edu.tw; Andoh, Tsugunobu; Chock, P. Boon

    2005-09-01

    Hormesis, a stress tolerance, can be induced by ischemic preconditioning stress. In addition to preconditioning, it may be induced by other means, such as gas anesthetics. Preconditioning mechanisms, which may be mediated by reprogramming survival genes and proteins, are obscure. A known neurotoxicant, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), causes less neurotoxicity in the mice that are preconditioned. Pharmacological evidences suggest that the signaling pathway of {center_dot}NO-cGMP-PKG (protein kinase G) may mediate preconditioning phenomenon. We developed a human SH-SY5Y cell model for investigating {sup {center_dot}}NO-mediated signaling pathway, gene regulation, and protein expression following a sublethal preconditioning stress caused by a brief 2-h serum deprivation. Preconditioned human SH-SY5Y cells are more resistant against severe oxidative stress and apoptosis caused by lethal serum deprivation and 1-mehtyl-4-phenylpyridinium (MPP{sup +}). Both sublethal and lethal oxidative stress caused by serum withdrawal increased neuronal nitric oxide synthase (nNOS/NOS1) expression and {sup {center_dot}}NO levels to a similar extent. In addition to free radical scavengers, inhibition of nNOS, guanylyl cyclase, and PKG blocks hormesis induced by preconditioning. S-nitrosothiols and 6-Br-cGMP produce a cytoprotection mimicking the action of preconditioning tolerance. There are two distinct cGMP-mediated survival pathways: (i) the up-regulation of a redox protein thioredoxin (Trx) for elevating mitochondrial levels of antioxidant protein Mn superoxide dismutase (MnSOD) and antiapoptotic protein Bcl-2, and (ii) the activation of mitochondrial ATP-sensitive potassium channels [K(ATP)]. Preconditioning induction of Trx increased tolerance against MPP{sup +}, which was blocked by Trx mRNA antisense oligonucleotide and Trx reductase inhibitor. It is concluded that Trx plays a pivotal role in {sup {center_dot}}NO-dependent preconditioning hormesis against

  7. Interactions between Nitric Oxide and Hypoxia-Inducible Factor Signaling Pathways in Inflammatory Disease

    PubMed Central

    Olson, Nels; van der Vliet, Albert

    2011-01-01

    Induction and activation of nitric oxide (NO) synthases (NOS) and excessive production of NO are common features of almost all diseases associated with infection and acute or chronic inflammation, although the contribution of NO to the pathophysiology of these diseases is highly multifactorial and often still a matter of controversy. Because of its direct impact on tissue oxygenation and cellular oxygen (O2) consumption and redistribution, the ability of NO to regulate various aspects of hypoxia-induced signaling has received widespread attention. Conditions of tissue hypoxia and the activation of hypoxia-inducible factors (HIF) have been implicated in hypoxia or in cancer biology, but are also being increasingly recognized as important features of acute and chronic inflammation. Thus, the activation of HIF transcription factors has been increasingly implicated in inflammatory diseases, and recent studies have indicated its critical importance in regulating phagocyte function, inflammatory mediator production, and regulation of epithelial integrity and repair processes. Finally, HIF also appears to contribute to important features of tissue fibrosis and epithelial-to-mesenchymal transition, processes that are associated with tissue remodeling in various non-malignant chronic inflammatory disorders. In this review, we briefly summarize the current state of knowledge with respect to the general mechanisms involved in HIF regulation and the impact of NO on HIF activation. Secondly, we will summarize the major recent findings demonstrating a role for HIF signaling in infection, inflammation, and tissue repair and remodeling, and will address the involvement of NO. The growing interest in hypoxia-induced signaling and its relation with NO biology is expected to lead to further insights into the complex roles of NO in acute or chronic inflammatory diseases and may point to the importance of HIF signaling as key feature of NO-mediated events during these disorders. PMID

  8. Nitric oxide-induced changes in intracellular zinc homeostasis are mediated by metallothionein/thionein.

    PubMed

    St Croix, Claudette M; Wasserloos, K J; Dineley, K E; Reynolds, I J; Levitan, E S; Pitt, B R

    2002-02-01

    We hypothesized that metallothionein (MT), a cysteine-rich protein with a strong affinity for Zn(2+), plays a role in nitric oxide (NO) signaling events via sequestration or release of Zn(2+) by the unique thiolate clusters of the protein. Exposing mouse lung fibroblasts (MLF) to the NO donor S-nitrosocysteine resulted in 20-30% increases in fluorescence of the Zn(2+)-specific fluorophore Zinquin that were rapidly reversed by the Zn(2+) chelator N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine. The absence of a NO-mediated increase in labile Zn(2+) in MLF from MT knockouts and its restoration after MT complementation by adenoviral gene transfer inferred a critical role for MT in the regulation of Zn(2+) homeostasis by NO. Additional data obtained in sheep pulmonary artery endothelial cells suggested a role for the apo form of MT, thionein (T), as a Zn(2+)-binding protein in intact cells, as overexpression of MT caused inhibition of NO-induced changes in labile Zn(2+) that were reversed by Zn(2+) supplementation. Furthermore, fluorescence-resonance energy-transfer data showed that overexpression of green fluorescent protein-modified MT prevented NO-induced conformational changes, which are indicative of Zn(2+) release from thiolate clusters. This effect was restored by Zn(2+) supplementation. Collectively, these data show that MT mediates NO-induced changes in intracellular Zn(2+) and suggest that the ratio of MT to T can regulate Zn(2+) homeostasis in response to nitrosative stress. PMID:11792622

  9. Minocycline attenuates experimental colitis in mice by blocking expression of inducible nitric oxide synthase and matrix metalloproteinases

    SciTech Connect

    Huang, T.-Y.; Chu, H.-C.; Lin, Y.-L.; Lin, C.-K.; Hsieh, T.-Y.; Chang, W.-K.; Chao, Y.-C.; Liao, C.-L.

    2009-05-15

    In addition to its antimicrobial activity, minocycline exerts anti-inflammatory effects in several disease models. However, whether minocycline affects the pathogenesis of inflammatory bowel disease has not been determined. We investigated the effects of minocycline on experimental colitis and its underlying mechanisms. Acute and chronic colitis were induced in mice by treatment with dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS), and the effect of minocycline on colonic injury was assessed clinically and histologically. Prophylactic and therapeutic treatment of mice with minocycline significantly diminished mortality rate and attenuated the severity of DSS-induced acute colitis. Mechanistically, minocycline administration suppressed inducible nitric oxide synthase (iNOS) expression and nitrotyrosine production, inhibited proinflammatory cytokine expression, repressed the elevated mRNA expression of matrix metalloproteinases (MMPs) 2, 3, 9, and 13, diminished the apoptotic index in colonic tissues, and inhibited nitric oxide production in the serum of mice with DSS-induced acute colitis. In DSS-induced chronic colitis, minocycline treatment also reduced body weight loss, improved colonic histology, and blocked expression of iNOS, proinflammatory cytokines, and MMPs from colonic tissues. Similarly, minocycline could ameliorate the severity of TNBS-induced acute colitis in mice by decreasing mortality rate and inhibiting proinflammatory cytokine expression in colonic tissues. These results demonstrate that minocycline protects mice against DSS- and TNBS-induced colitis, probably via inhibition of iNOS and MMP expression in intestinal tissues. Therefore, minocycline is a potential remedy for human inflammatory bowel diseases.

  10. Interplay between mitogen-activated protein kinase and nitric oxide in brassinosteroid-induced pesticide metabolism in Solanum lycopersicum.

    PubMed

    Yin, Yan-Ling; Zhou, Yue; Zhou, Yan-Hong; Shi, Kai; Zhou, Jie; Yu, Yunlong; Yu, Jing-Quan; Xia, Xiao-Jian

    2016-10-01

    Nitric oxide (NO) and mitogen-activated protein kinase (MPK) play important roles in brassinosteroid (BR)-induced stress tolerance, however, their functions in BR-induced pesticides metabolism remain unclear. Here, we showed that MPK activity and transcripts of SlMPK1 and SlMPK2 were induced by chlorothalonil (CHT), a widely used fungicide, in tomato leaves. However, cosilencing of SlMPK1/2 compromised the 24-epibrassinolide (EBR)-induced upregulation of detoxification genes and CHT metabolism in tomato leaves. In addition, cosilencing of SlMPK1/2 inhibited the accumulation of S-nitrosothiol (SNO), the reservoir of nitric oxide (NO) in plants, whereas tungstate, the inhibitor of nitrate reductase (NR), blocked EBR-induced SNO accumulation and MPK activity. Inhibiting the accumulation of NO by cPTIO, the specific scavenger and tungstate abolished the EBR-induced upregulation of detoxification genes, glutathione accumulation and CHT metabolism. The results showed that MPK and NR-dependent NO were involved in BR-induced CHT metabolism. Notably, there was a positive crosstalk between the MPK and NO production. PMID:27236431

  11. Nitric oxide synthase promotes distension-induced tracheal venular leukocyte adherence.

    PubMed

    Moldobaeva, Aigul; Rentsendorj, Otgonchimeg; Jenkins, John; Wagner, Elizabeth M

    2014-01-01

    The process of leukocyte recruitment to the airways in real time has not been extensively studied, yet airway inflammation persists as a major contributor to lung pathology. We showed previously in vivo, that neutrophils are recruited acutely to the large airways after periods of airway distension imposed by the application of positive end-expiratory pressure (PEEP). Given extensive literature implicating products of nitric oxide synthase (NOS) in lung injury after ventilatory over-distension, we questioned whether similar mechanisms exist in airway post-capillary venules. Yet, endothelial nitric oxide has been shown to be largely anti-inflammatory in other systemic venules. Using intravital microscopy to visualize post-capillary tracheal venules in anesthetized, ventilated mice, the number of adherent leukocytes was significantly decreased in eNOS-/- mice under baseline conditions (2±1 cell/60 min observation) vs wild type (WT) C57BL/6 mice (7±2 cells). After exposure to PEEP (8 cmH2O for 1 min; 5 times), adherent cells increased significantly (29±5 cells) in WT mice while eNOS-/- mice demonstrated a significantly decreased number of adherent cells (11±4 cells) after PEEP. A similar response was seen when thrombin was used as the pro-inflammatory stimulus. In addition, mouse tracheal venular endothelial cells studied in vitro after exposure to cyclic stretch (18% elongation) or thrombin both demonstrated increased p-selectin expression that was significantly attenuated by NG-nitro-L-arginine methyl ester, N-acetylcysteine amide (NACA) and excess BH4. In vivo treatment with the ROS inhibitor NACA or co-factor BH4 abolished completely the PEEP-induced leukocyte adherence. These results suggest that pro-inflammatory stimuli cause leukocyte recruitment to tracheal endothelium in part due to eNOS uncoupling. PMID:25181540

  12. Nitric Oxide Synthase Promotes Distension-Induced Tracheal Venular Leukocyte Adherence

    PubMed Central

    Moldobaeva, Aigul; Rentsendorj, Otgonchimeg; Jenkins, John; Wagner, Elizabeth M.

    2014-01-01

    The process of leukocyte recruitment to the airways in real time has not been extensively studied, yet airway inflammation persists as a major contributor to lung pathology. We showed previously in vivo, that neutrophils are recruited acutely to the large airways after periods of airway distension imposed by the application of positive end-expiratory pressure (PEEP). Given extensive literature implicating products of nitric oxide synthase (NOS) in lung injury after ventilatory over-distension, we questioned whether similar mechanisms exist in airway post-capillary venules. Yet, endothelial nitric oxide has been shown to be largely anti-inflammatory in other systemic venules. Using intravital microscopy to visualize post-capillary tracheal venules in anesthetized, ventilated mice, the number of adherent leukocytes was significantly decreased in eNOS-/- mice under baseline conditions (2±1 cell/60 min observation) vs wild type (WT) C57BL/6 mice (7±2 cells). After exposure to PEEP (8 cmH2O for 1 min; 5 times), adherent cells increased significantly (29±5 cells) in WT mice while eNOS-/- mice demonstrated a significantly decreased number of adherent cells (11±4 cells) after PEEP. A similar response was seen when thrombin was used as the pro-inflammatory stimulus. In addition, mouse tracheal venular endothelial cells studied in vitro after exposure to cyclic stretch (18% elongation) or thrombin both demonstrated increased p-selectin expression that was significantly attenuated by NG-nitro-L-arginine methyl ester, N-acetylcysteine amide (NACA) and excess BH4. In vivo treatment with the ROS inhibitor NACA or co-factor BH4 abolished completely the PEEP-induced leukocyte adherence. These results suggest that pro-inflammatory stimuli cause leukocyte recruitment to tracheal endothelium in part due to eNOS uncoupling. PMID:25181540

  13. Inducible nitric oxide synthase gene expression in brain following cerebral ischemia

    SciTech Connect

    Iadecola, C.; Zhang, Fangyi; Xu, S.

    1995-05-01

    Cerebral ischemia is followed by a local inflammatory response that is thought to participate in the extension of the tissue damage occurring in the postischemic period. However, the mechanisms whereby the inflammation contributes to the progression of the damage have not been fully elucidated. In models of inflammation, expression of the inducible isoform of nitric oxide synthase (iNOS) is responsible for cytotoxicity through the production of large amounts of nitric oxide (NO). In this study, therefore, we sought to establish whether iNOS is expressed in the ischemic brain. Rats were killed 6 h to 7 days after occlusion of the middle cerebral artery. iNOS expression in the ischemic area was determined by reverse-transcription polymerase chain reaction. Porphobilinogen deaminase mRNA was detected in the same sample and used for normalization. In the ischemic brain, there was expression of iNOS mRNA that began at 12 h, peaked at 48 h, and returned to baseline at 7 days (n = 3/time point). iNOS mRNA expression paralleled the time course of induction of iNOS catalytic activity, determined by the citrulline assay (17.4 {+-} 4.4 pmol citrulline/{mu}g protein/min at 48 h; mean {+-} SD; n = 5 per time point). iNOS immunoreactivity was seen in neutrophils at 48-96 h after ischemia. The data provide molecular, biochemical, and immunocytochemical evidence of iNOS induction following focal cerebral ischemia. These findings, in concert with our recent demonstration that inhibition of iNOS reduces infarct volume in the same stroke model, indicate that NO production may play an important pathogenic role in the progression of the tissue damage that follows cerebral ischemia. 35 refs., 3 figs.

  14. Trans Fatty Acids Induce Vascular Inflammation and Reduce Vascular Nitric Oxide Production in Endothelial Cells

    PubMed Central

    Iwata, Naomi G.; Pham, Matilda; Rizzo, Norma O.; Cheng, Andrew M.; Maloney, Ezekiel; Kim, Francis

    2011-01-01

    Intake of trans fatty acids (TFA), which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO) bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived—dairy products and meat) on endothelial NF-κB activation and nitric oxide (NO) production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans)), Linoelaidic (trans-C18:2 (9 trans, 12 trans)), and Transvaccenic (trans-C18:1 (11 trans)) for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses) did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation. PMID:22216328

  15. Cardiac-specific overexpression of inducible nitric oxide synthase does not result in severe cardiac dysfunction.

    PubMed

    Heger, Jacqueline; Gödecke, Axel; Flögel, Ulrich; Merx, Marc W; Molojavyi, Andrei; Kühn-Velten, W Nikolaus; Schrader, Jürgen

    2002-01-11

    Nitric oxide (NO), a potent regulator of myocardial contractility, has been implicated in the development of heart failure; however, no study exists describing the relation between expression of inducible nitric oxide synthase (iNOS), formation of NO in vivo, and cardiac contractility. We have therefore generated transgenic (TG) mice overexpressing iNOS under the cardiospecific alpha-myosin heavy chain (alpha-MHC) promoter. In vitro, iNOS activity in hearts of two transgenic lines was 260- to 400-fold above controls (wild type [WT]), but TG mice were viable and appeared normal. Ventricular mass/body weight ratio did not differ; heart rate and cardiac output as well as mean arterial blood pressure were decreased by 10%. NO(x) levels of hearts and blood of TG mice were 2.5- and 2-fold above WT controls, respectively. In the isolated heart, release of the NO oxidation products nitrate and nitrite, an index of in vivo NOS activity, was 40-fold over WT. However, cardiac hemodynamics and levels of ATP and phosphocreatine were unaltered. The high iNOS activity was associated with reduced cardiac L-arginine in TG hearts to only 15% of the WT, indicating limited substrate availability, whereas L-citrulline was 20-fold elevated. Our findings demonstrate that the heart can tolerate high levels of iNOS activity without detrimental functional consequences. The concept that iNOS-derived NO is the triggering factor in the pathomechanism leading to heart failure therefore needs to be reevaluated. PMID:11786524

  16. Electrical activity induced by nitric oxide in canine colonic circular muscle.

    PubMed

    Keef, K D; Anderson, U; O'Driscoll, K; Ward, S M; Sanders, K M

    2002-01-01

    Nitric oxide generates slow electrical oscillations (SEOs) in cells near the myenteric edge of the circular muscle layer, which resemble slow waves generated by interstitial cells of Cajal (ICCs) at the submucosal edge of this muscle. The properties of SEOs were studied to determine whether these events are similar to slow waves. Rapid frequency membrane potential oscillations (MPOs; 16 +/- 1 cycles/min and 9.6 +/- 0.2 mV) were recorded from control muscles near the myenteric edge. Sodium nitroprusside (0.3 microM) reduced MPOs and initiated SEOs (1.3 +/- 0.3 cycles/min and 13.4 +/- 1.4 mV amplitude). SEOs were abolished by the guanylate cyclase inhibitor 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxaline-1-one (10 microM). MPOs were abolished by nifedipine (1 microM), whereas SEO frequency increased and the amount of depolarization decreased. BAY K 8644 (1 microM) prolonged SEOs and reduced their frequency. SEOs were abolished by Ni(2+) (0.5 mM), low Ca(2+) solution (0.1 mM Ca(2+)), cyclopiazonic acid (10 microM), and the mitochondrial uncouplers antimycin (10 microM) and carbonyl cyanide p-trifluoromethoxyphenylhydrazone (1 microM). Oligomycin (10 microM) was without effect. These effects are similar to those described for colonic slow waves. Our results suggest that nitric oxide-induced SEOs are similar in mechanism to slow waves, an activity not previously thought to be generated by myenteric pacemakers. PMID:11751165

  17. Mechanism and Kinetics of Inducible Nitric Oxide Synthase Auto-S-Nitrosation and Inactivation†

    PubMed Central

    Smith, Brian C.; Fernhoff, Nathaniel B.; Marletta, Michael A.

    2012-01-01

    Nitric oxide (NO), the product of the nitric oxide synthase (NOS) reaction, was previously shown to result in S-nitrosation of the NOS Zn2+-tetrathiolate and inactivation of the enzyme. To probe the potential physiological significance of NOS S-nitrosation, the inactivation timescale of the inducible NOS isoform (iNOS) was determined and found to directly correlate with an increase in iNOS S-nitrosation. A kinetic model of NOS inactivation in which arginine is treated as a suicide substrate was developed. In this model, NO synthesized at the heme cofactor is partitioned between release into solution (NO release pathway) and NOS S-nitrosation followed by NOS inactivation (inactivation pathway). Experimentally determined progress curves of NO formation were fit to the model. The NO release pathway was perturbed through addition of the NO traps oxymyoglobin (MbO2) and β2 H-NOX, which yielded partition ratios between NO release and inactivation of ~100 at 4 μM MbO2 and ~22,000 at saturating trap concentrations. The results suggest that a portion of the NO synthesized at the heme cofactor reacts with the Zn2+-tetrathiolate without being released into solution. Perturbation of the inactivation pathway through addition of the reducing agents GSH or TCEP resulted in a concentration-dependent decrease in iNOS S-nitrosation that directly correlated with protection from iNOS inactivation. iNOS inactivation was most responsive to physiological concentrations of GSH with an apparent Km value of 13 mM. NOS turnover that leads to NOS S-nitrosation might be a mechanism to control NOS activity, and NOS S-nitrosation could play a role in the physiological generation of nitrosothiols. PMID:22242685

  18. Ventilator-induced lung injury is reduced in transgenic mice that overexpress endothelial nitric oxide synthase.

    PubMed

    Takenaka, Kaori; Nishimura, Yoshihiro; Nishiuma, Teruaki; Sakashita, Akihiro; Yamashita, Tomoya; Kobayashi, Kazuyuki; Satouchi, Miyako; Ishida, Tatsuro; Kawashima, Seinosuke; Yokoyama, Mitsuhiro

    2006-06-01

    Although mechanical ventilation (MV) is an important supportive strategy for patients with acute respiratory distress syndrome, MV itself can cause a type of acute lung damage termed ventilator-induced lung injury (VILI). Because nitric oxide (NO) has been reported to play roles in the pathogenesis of acute lung injury, the present study explores the effects on VILI of NO derived from chronically overexpressed endothelial nitric oxide synthase (eNOS). Anesthetized eNOS-transgenic (Tg) and wild-type (WT) C57BL/6 mice were ventilated at high or low tidal volume (Vt; 20 or 7 ml/kg, respectively) for 4 h. After MV, lung damage, including neutrophil infiltration, water leakage, and cytokine concentration in bronchoalveolar lavage fluid (BALF) and plasma, was evaluated. Some mice were given N(omega)-nitro-L-arginine methyl ester (L-NAME), a potent NOS inhibitor, via drinking water (1 mg/ml) for 1 wk before MV. Histological analysis revealed that high Vt ventilation caused severe VILI, whereas low Vt ventilation caused minimal VILI. Under high Vt conditions, neutrophil infiltration and lung water content were significantly attenuated in eNOS-Tg mice compared with WT animals. The concentrations of macrophage inflammatory protein-2 in BALF and plasma, as well as plasma tumor necrosis factor-alpha and monocyte chemoattractant protein-1, also were decreased in eNOS-Tg mice. L-NAME abrogated the beneficial effect of eNOS overexpression. In conclusion, chronic eNOS overexpression may protect the lung from VILI by inhibiting the production of inflammatory chemokines and cytokines that are associated with neutrophil infiltration into the air space. PMID:16399791

  19. Interferon-γ-Induced Nitric Oxide Causes Intrinsic Intestinal Denervation in Trypanosoma cruzi-Infected Mice

    PubMed Central

    Arantes, Rosa M.E.; Marche, Homero H.F.; Bahia, Maria T.; Cunha, Fernando Q.; Rossi, Marcos A.; Silva, João S.

    2004-01-01

    In this study, the role of nitric oxide (NO) in neuronal destruction during acute-phase Trypanosoma cruzi infection was evaluated in male C57BL/6 (WT, wild-type) mice and knockout mice [inducible nitric oxide synthase (iNOS)−/− and interferon (IFN)−/−]. Selected animals were infected by intraperitoneal injection of 100 trypomastigote forms of the Y strain of T. cruzi. Others were injected intraperitoneally with an equal volume of saline solution and served as controls. Our findings support those of previous studies regarding myenteric denervation in acute-phase T. cruzi infection. In addition, we clearly demonstrate that, despite the fact that parasite nests and similar inflammatory infiltrate in the intestinal wall were more pronounced in infected iNOS−/− mice than in infected WT mice, the former presented no reduction in myenteric plexus neuron numbers. Neuronal nerve profile expression, as revealed by the general nerve marker PGP 9.5, was preserved in all knockout animals. Infected IFN−/− mice suffered no significant neuronal loss and there was no inflammatory infiltrate in the intestinal wall. On days 5 and 10 after infection, iNOS activity was greater in infected WT mice than in controls, whereas iNOS activity in infected knockout mice remained unchanged. These findings clearly demonstrate that neuronal damage does not occur in NO-impaired infected knockout mice, regardless of whether inflammatory infiltrate is present (iNOS−/−) or absent (IFN−/−). In conclusion, our observations strongly indicate that myenteric denervation in acute-phase T. cruzi infection is because of IFN-γ-elicited NO production resulting from iNOS activation in the inflammatory foci along the intestinal wall. PMID:15039223

  20. Cardiorespiratory effects induced by 2-nitrate-1,3-dibuthoxypropan are reduced by nitric oxide scavenger in rats.

    PubMed

    Queiroz, Thyago M; Mendes-Júnior, Leônidas G; Guimarães, Drielle D; França-Silva, Maria S; Nalivaiko, Eugene; Braga, Valdir A

    2014-04-01

    The search for new nitric oxide donors is warranted by the limitations of organic nitrates currently used in cardiology. The new organic nitrate 2-nitrate-1,3-dibuthoxypropan (NDBP) exhibited promising cardiovascular activities in previous studies. The aim of this study was to investigate the cardiorespiratory responses evoked by NDBP and to compare them to the clinically used organic nitrate nitroglycerine (NTG). Arterial pressure, heart rate and respiration were recorded in conscious adult male Wistar rats. Bolus i.v. injection of NDBP (1 to 15mg/kg; n=8) and NTG (0.1 to 5mg/kg; n=8) produced hypotension. NDBP induced bradycardia at all doses, while NTG induced tachycardia at three lower doses but bradycardia at higher doses. Hydroxocobalamin (20mg/kg; HDX), a NO scavenger, blunted hypotension induced by NDBP (15mg/kg), and its bradycardic effect (n=6). In addition, HDX blunted both hypotension and bradycardia induced by a single dose of NTG (2.5mg/kg; n=6). Both NDBP and NTG altered respiratory rate, inducing a biphasic effect with a bradypnea followed by a tachypnea; HDX attenuated these responses. Our data indicate that NDBP and NTG induce hypotension, bradycardia and bradypnea, which are mediated by nitric oxide release. PMID:24418115

  1. Berberine Decreased Inducible Nitric Oxide Synthase mRNA Stability through Negative Regulation of Human Antigen R in Lipopolysaccharide-Induced Macrophages.

    PubMed

    Shin, Ji-Sun; Choi, Hye-Eun; Seo, SeungHwan; Choi, Jung-Hye; Baek, Nam-In; Lee, Kyung-Tae

    2016-07-01

    Berberine, a major isoquinoline alkaloid found in medicinal herbs, has been reported to possess anti-inflammatory effects; however, the underlying mechanisms responsible for its actions are poorly understood. In the present study, we investigated the inhibitory effects of berberine and the molecular mechanisms involved in lipopolysaccharide (LPS)-treated RAW 264.7 and THP-1 macrophages and its effects in LPS-induced septic shock in mice. In both macrophage cell types, berberine inhibited the LPS-induced nitric oxide (NO) production and inducible NO synthase (iNOS) protein expression, but it had no effect on iNOS mRNA transcription. Suppression of LPS-induced iNOS protein expression by berberine occurred via a human antigen R (HuR)-mediated reduction of iNOS mRNA stability. Molecular data revealed that the suppression on the LPS-induced HuR binding to iNOS mRNA by berberine was accompanied by a reduction in nucleocytoplasmic HuR shuttling. Pretreatment with berberine reduced LPS-induced iNOS protein expression and the cytoplasmic translocation of HuR in liver tissues and increased the survival rate of mice with LPS-induced endotoxemia. These results show that the suppression of iNOS protein expression by berberine under LPS-induced inflammatory conditions is associated with a reduction in iNOS mRNA stability resulting from inhibition of the cytoplasmic translocation of HuR. PMID:27189969

  2. Endothelial Nitric Oxide Synthase Deficient Mice Are Protected from Lipopolysaccharide Induced Acute Lung Injury

    PubMed Central

    Gross, Christine M.; Rafikov, Ruslan; Kumar, Sanjiv; Aggarwal, Saurabh; Ham III, P. Benson; Meadows, Mary Louise; Cherian-Shaw, Mary; Kangath, Archana; Sridhar, Supriya; Lucas, Rudolf; Black, Stephen M.

    2015-01-01

    Lipopolysaccharide (LPS) derived from the outer membrane of gram-negative bacteria induces acute lung injury (ALI) in mice. This injury is associated with lung edema, inflammation, diffuse alveolar damage, and severe respiratory insufficiency. We have previously reported that LPS-mediated nitric oxide synthase (NOS) uncoupling, through increases in asymmetric dimethylarginine (ADMA), plays an important role in the development of ALI through the generation of reactive oxygen and nitrogen species. Therefore, the focus of this study was to determine whether mice deficient in endothelial NOS (eNOS-/-) are protected against ALI. In both wild-type and eNOS-/- mice, ALI was induced by the intratracheal instillation of LPS (2 mg/kg). After 24 hours, we found that eNOS-/-mice were protected against the LPS mediated increase in inflammatory cell infiltration, inflammatory cytokine production, and lung injury. In addition, LPS exposed eNOS-/- mice had increased oxygen saturation and improved lung mechanics. The protection in eNOS-/- mice was associated with an attenuated production of NO, NOS derived superoxide, and peroxynitrite. Furthermore, we found that eNOS-/- mice had less RhoA activation that correlated with a reduction in RhoA nitration at Tyr34. Finally, we found that the reduction in NOS uncoupling in eNOS-/- mice was due to a preservation of dimethylarginine dimethylaminohydrolase (DDAH) activity that prevented the LPS-mediated increase in ADMA. Together our data suggest that eNOS derived reactive species play an important role in the development of LPS-mediated lung injury. PMID:25786132

  3. Nitric oxide content and apoptosis rate in steroid-induced avascular necrosis of the femoral head

    PubMed Central

    BAI, RUI; LIU, WANLIN; ZHAO, AIQING; ZHAO, ZHENGQUN; JIANG, DIANMING

    2015-01-01

    The aim of the present study was to explore the effect on nitric oxide (NO) content and osteocyte apoptosis of steroid-induced avascular necrosis of the femoral head (SANFH) in an animal model of SANFH. A total of 40 Japanese white rabbits, 5 months of age and weighing 2.5±0.5 kg, were randomly divided into groups A (hormone + endotoxin group), B (endotoxin + normal saline group), C (normal saline + hormone group) and D (control group). Following the establishment of the model, a blood sample was taken from the heart of each animal and centrifuged; the levels of NO in the serum were detected. The bilateral femoral heads were conventionally dissected, fixed, decalcified and stained with hematoxylin and eosin. Subsequently, the empty bone lacunae were counted under an optical microscope. Changes in osteocyte morphology were observed using electron microscopy and osteocyte apoptosis was detected with a terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The percentage of empty bone lacunae in group A was significantly higher compared with that in groups B, C and D (P<0.01); however, there was no significant difference in percentage among groups B, C and D. The NO content in group A was significantly higher compared with that in groups B, C and D (P<0.01); however, there was no significant difference in NO content among groups B, C and D. The osteocyte apoptosis index in group A was significantly higher compared with that in the other groups (P<0.01); there was no significant difference among groups B, C and D. NO content was positively correlated with osteocyte apoptosis index (r=0.707). Thus, the present study found that NO content and the osteocyte apoptosis index were increased in SANFH, and that they play an important role in SANFH. The content of NO was positively correlated with the osteocyte apoptosis index, indicating that NO induces apoptosis. PMID:26622359

  4. Nitric oxide is involved in alkamide-induced lateral root development in Arabidopsis.

    PubMed

    Méndez-Bravo, Alfonso; Raya-González, Javier; Herrera-Estrella, Luis; López-Bucio, José

    2010-10-01

    Alkamides are small bioactive lipid signals with a wide distribution in plants. In this report, the role of nitric oxide (NO) in the alterations induced by N-isobutyl decanamide on the Arabidopsis (Arabidopsis thaliana) root system architecture (RSA) was investigated. We first compared the effects of N-isobutyl decanamide and NO donors sodium nitropruside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP) on root morphogenetic processes. Both N-isobutyl decanamide and NO donors modulated RSA in a similar way and in a dose-dependent manner, inhibiting primary root growth and promoting lateral root primordia (LRP) formation. RSA alterations induced by N-isobutyl decanamide correlated with NO accumulation in the primary root tip and in developing lateral roots. Morphogenetic effects of N-isobutyl decanamide decreased when NO scavengers were supplied to alkamide-treated seedlings. N-Isobutyl decanamide-regulated root architectural changes were also investigated in mutants defective in NO biosynthesis, nia1 nia2, and NO signalling, Atnoa1, and in the alkamide-resistant mutant drr1. The nia1 nia2 and Atnoa1 mutants were indistinguishable in primary root growth inhibition by the alkamide when compared with wild-type (WT) seedlings, but showed reduced lateral root responses. The drr1 mutant was less sensitive in both primary root growth inhibition and LRP induction by NO donors than WT seedlings. Detailed DR5:uidA and BA3:uidA marker analysis showed that N-isobutyl decanamide and its interacting signals jasmonic acid and NO act downstream or independently of auxin-responsive gene expression to promote LRP formation. Our results provide compelling evidence that NO is an intermediate in alkamide signaling mediating RSA adjustment in Arabidopsis. PMID:20685967

  5. Interaction between abscisic acid and nitric oxide in PB90-induced catharanthine biosynthesis of catharanthus roseus cell suspension cultures.

    PubMed

    Chen, Qian; Chen, Zunwei; Lu, Li; Jin, Haihong; Sun, Lina; Yu, Qin; Xu, Hongke; Yang, Fengxia; Fu, Mengna; Li, Shengchao; Wang, Huizhong; Xu, Maojun

    2013-01-01

    Elicitations are considered to be an important strategy to improve production of secondary metabolites of plant cell cultures. However, mechanisms responsible for the elicitor-induced production of secondary metabolites of plant cells have not yet been fully elucidated. Here, we report that treatment of Catharanthus roseus cell suspension cultures with PB90, a protein elicitor from Phytophthora boehmeriae, induced rapid increases of abscisic acid (ABA) and nitric oxide (NO), subsequently followed by the enhancement of catharanthine production and up-regulation of Str and Tdc, two important genes in catharanthine biosynthesis. PB90-induced catharanthine production and the gene expression were suppressed by the ABA inhibitor and NO scavenger respectively, showing that ABA and NO are essential for the elicitor-induced catharanthine biosynthesis. The relationship between ABA and NO in mediating catharanthine biosynthesis was further investigated. Treatment of the cells with ABA triggered NO accumulation and induced catharanthine production and up-regulation of Str and Tdc. ABA-induced catharanthine production and gene expressions were suppressed by the NO scavenger. Conversely, exogenous application of NO did not stimulate ABA generation and treatment with ABA inhibitor did not suppress NO-induced catharanthine production and gene expressions. Together, the results showed that both NO and ABA were involved in PB90-induced catharanthine biosynthesis of C. roseus cells. Furthermore, our data demonstrated that ABA acted upstream of NO in the signaling cascade leading to PB90-induced catharanthine biosynthesis of C. roseus cells. PMID:23554409

  6. Ethanol attenuates vasorelaxation via inhibition of inducible nitric oxide synthase in rat artery exposed to interleukin-1β.

    PubMed

    Yuui, K; Kudo, R; Kasuda, S; Hatake, K

    2016-09-01

    Nitric oxide produced by inducible nitric oxide synthase (iNOS) regulates sepsis-induced hypotension. During septic shock, interleukin (IL)-1β is synthesized in endothelial cells and smooth muscle cells by endotoxin. Ethanol (EtOH) suppresses endotoxin-induced hypotension. The present study aimed to elucidate the effect of EtOH on gradual relaxation and iNOS expression induced by IL-1β in isolated rat superior mesenteric arteries (SMAs). Exposure to IL-1β-induced contraction in SMA rings, followed by a gradual relaxation of phenylephrine precontracted tone. Contraction was abolished by indomethacin (IM), cycloheximide (Chx), and endothelium denudation. In contrast, the gradual relaxation was abolished by NOS inhibitors, Chx, endothelium denudation, and inhibited by EtOH (50 and 100 mM). However, IM had no effect on relaxation. Western blot analysis demonstrated that iNOS expression was induced by IL-1β and was inhibited by EtOH and endothelium denudation. Furthermore, messenger RNA expression of iNOS, but not endothelial NOS, was inhibited by EtOH. These data suggest that IL-1β-induced contraction is mediated by thromboxane A2, whereas IL-1β-induced relaxation occurs via NO derived from iNOS. The endothelium plays an important role in vasorelaxation. Taken together, EtOH inhibits IL-1β-mediated vasorelaxation by suppressing endothelium iNOS expression. This study provides the first evidence of EtOH -induced inhibition of IL-1β-mediated vasorelaxation. PMID:26500219

  7. Role of Mitogen-Activated Protein Kinases in Peptidoglycan-Induced Expression of Inducible Nitric Oxide Synthase and Nitric Oxide in Mouse Peritoneal Macrophages: Extracellular Signal-Related Kinase, a Negative Regulator ▿ †

    PubMed Central

    Bhatt, Kunal H.; Sodhi, Ajit; Chakraborty, Rituparna

    2011-01-01

    The expression of inducible nitric oxide synthase (iNOS) and the production of nitric oxide (NO) are important host defense mechanisms against pathogens in mononuclear phagocytes. The objectives of this study were to examine the roles of mitogen-activated protein kinases (MAPKs) and transcription factors (nuclear factor-κB [NF-κB] and activating protein 1 [AP-1]) in peptidoglycan (PGN)-induced iNOS expression and NO production in macrophages. PGN is a cell wall component of Gram-positive bacteria that stimulates inflammatory responses both ex vivo and in vivo. PGN stimulates the activation of all three classes of MAPKs, extracellular signal-related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38mapk in macrophages, albeit with differential activation kinetics. Using a selective inhibitor of JNK (SP600125) and JNK1/2 small interfering RNA (siRNA) knocked-down macrophages, it was observed that PGN-induced iNOS and NO expression is significantly inhibited. This suggested that JNK MAPK plays an essential role in PGN-induced iNOS expression and NO production. In contrast, inhibition of the ERK pathway using PD98059 dose dependently enhanced PGN-induced iNOS expression and NO production. PGN-induced ERK activation was attenuated in ERK1/2 siRNA knocked-down macrophages; however, NO and iNOS expression were significantly enhanced. An electrophoretic mobility shift assay showed that SP600125 inhibited PGN-induced NF-κB and AP-1 activation, whereas inhibition of the ERK pathway enhanced NF-κB activation, but with no effect on AP-1. These results indicate that the JNK MAPK positively regulate PGN-induced iNOS and NO expression by activating NF-κB and AP-1 transcription factors, whereas the ERK pathway plays a negative regulatory role via affecting NF-κB activity. PMID:21450974

  8. Microglial cell death induced by glycated bovine serum albumin: nitric oxide involvement.

    PubMed

    Khazaei, Mohammad R; Habibi-Rezaei, Mehran; Karimzadeh, Fereshteh; Moosavi-Movahedi, Ali Akbar; Sarrafnejhad, Abdo Alfattah; Sabouni, Farzaneh; Bakhti, Mostafa

    2008-08-01

    Nonenzymatic glycation results in the formation of advanced glycation end products (AGEs) through a nonenzymatic multistep reaction of reducing sugars with proteins. AGEs have been suspected to be involved in the pathogenesis of several chronic clinical neurodegenerative complications including Alzheimer's disease, which is characterized with the activation of microglial cells in neuritic plaques. To find out the consequence of this activation on microglial cells, we treated the cultured microglial cells with different glycation levels of Bovine Serum Albumin (BSA) which were prepared in vitro. Extent of glycation of protein has been characterized during 16 weeks of incubation with glucose. Treatment of microglial cells with various levels of glycated albumin induced nitric oxide (NO) production and consequently cell death. We also tried to find out the mode of death in AGE-activated microglial cells. Altogether, our results suggest that AGE treatment causes microglia to undergo NO-mediated apoptotic and necrotic cell death in short term and long term, respectively. NO production is a consequence of iNOS expression in a JNK dependent RAGE signalling after activation of RAGE by AGE-BSA. PMID:18463114

  9. Mucosal nitric oxide is not responsible for the hemodynamic changes induced by nicotine in rat stomachs.

    PubMed

    Wong, D; Qiu, B S; Ko, J K; Koo, M W; Cho, C H

    1996-05-15

    It has been shown that chronic nicotine treatment decreases gastric mucosal blood flow (GMBF). The mechanism for this action is still not defined. In this study, nicotine treatment (5, 25 or 50 μg/ml drinking water) for 10 days dose dependently reduced the GMBF and volume of hemoglobin but increased ethanol-induced gastric damage. These effects were potentiated by N(ω)-nitro-l-arginine methyl ester (l-NAME), a nitric oxide (NO) synthase inhibitor. l-arginine but not the d-analog restored the actions of l-NAME, indicating that the selective action of l-NAME. However, the potentiating actions of l-NAME were significantly attenuated in the nicotine-pretreated rats. When the basal mucosal NO synthase (both iNOS and cNOS) activity and its second messenger cyclic GMP levels were measured, no difference was found between the nicotine and the non-nicotine groups. Furthermore, high dose of l-arginine could not reverse the action of nicotine. These findings suggest that the adverse action of chronic nicotine treatment on GMBF and lesion formation is probably mediated through a NO independent mechanism. PMID:21781677

  10. Glucocorticoids enhance concanavalin A-induced mitogenic response through the inhibition of nitric oxide production.

    PubMed Central

    Ramírez, F; Silva, A

    1997-01-01

    Glucocorticoids (GC) are known to inhibit mitogen-induced proliferation of T cells. In this study we show two experimental situations where the addition of GC increases lymphocyte proliferation. It has been reported by different authors that rat spleen (SPL) cells proliferate poorly after concanavalin A (Con A) activation. These poor responses have been related to the suppressor activity of macrophages. Similarly, it is known that T-cell proliferation is depressed in the presence of an excess of macrophages in the culture. Here we show that in both experimental situations, the inclusion of dexamethasone (DEX), a synthetic glucocorticoid, in the culture medium enhances the Con A-stimulated proliferation. We provide evidence that this effect is a consequence of the inhibition of nitric oxide (NO) synthesis by the hormone. Furthermore, we also demonstrate that rat SPL cells are inefficient antigen-presenting cells (APC) because of their spontaneous high production of NO. Taken together our results suggest that the effects of GC on T-cell activation may be to promote or inhibit proliferation depending on the level of endogenous NO synthesis. The possible significance of these results is briefly discussed. Images Figure 2 Figure 4 Figure 5 PMID:9038714

  11. Stimulation of the NADPH oxidase in activated rat microglia removes nitric oxide but induces peroxynitrite production.

    PubMed

    Bal-Price, Anna; Matthias, Anita; Brown, Guy C

    2002-01-01

    Cultured rat microglia produced extracellular superoxide at a rate of 814 +/- 52 pmol/min/million cells when stimulated with phorbol 12-myristate 13-acetate (PMA) as measured by extracellular cytochrome c reduction. This superoxide production resulted in a rapid rate of superoxide dismutase-sensitive nitric oxide (NO) breakdown (155 +/- 30 pmol of NO/min/million cells) when NO was added to PMA stimulated microglia. Lipopolysaccharide/interferon-gamma (LPS/IFN-gamma)-activated microglia produce NO at the rate of 145 +/- 42 pmol/min/million cells and activated astrocytes at the rate of 51 +/- 9 pmol/min/million cells as estimated by NO electrode. Both types of cells maintained a steady-state level of 0.5-0.7 microm NO, only in the presence of L-arginine. Addition of PMA to activated microglia (but not activated astrocytes) caused the rapid and complete disappearance of all extracellular NO (but was restored in the presence of superoxide dismutase) followed by the production of peroxynitrite (as measured by urate-sensitive oxidation of dihydrorhodamine). Co-incubation of activated microglia with cerebellar granule neurones resulted in NO inhibition of neuronal respiration, but this was rapidly removed by PMA-induced breakdown of the NO. Thus, microglial NADPH oxidase can regulate the bioavailability of NO and the production of peroxynitrite. PMID:11796745

  12. Differential expression of inducible nitric oxide synthase in keratocystic odontogenic tumors prior and subsequent to decompression

    PubMed Central

    XU, WEI; SONG, XIAOMENG; ZHANG, XIAOMIN; WANG, ZHAO; DING, XU; YUAN, YE; WU, YUNONG; WU, HEMING

    2016-01-01

    The aim of the present study was to investigate the expression of inducible nitric oxide synthase (iNOS) in keratocystic odontogenic tumors (KCOTs) prior and subsequent to decompression and to explore the association between iNOS expression and changes in clinical features. Sixteen pairs of specimens obtained at the time of decompression and subsequent curettages were collected and immunohistochemically examined using an antibody against iNOS. The intensity of iNOS staining was evaluated semi-quantitatively for statistical analysis. Prior to decompression, 87.5% of KCOT samples showed no immunohistochemical reactivity for iNOS. Only 12.5% of samples exhibited slight staining for iNOS in the cytoplasm of cells in the epithelial layer. Subsequent to decompression, all the samples exhibited moderate to intense staining for iNOS in the cytoplasm and membrane of cells in the epithelial and fibrous layers. This increased expression of iNOS following decompression was statistically significant (P<0.01). The results demonstrated distinct expression of iNOS in KCOT samples prior and subsequent to decompression, indicating that iNOS may have a role in mediating changes in clinical features. PMID:27073658

  13. Inducible nitric oxide synthase mediates early epithelial repair of porcine ileum.

    PubMed

    Gookin, Jody L; Rhoads, J Marc; Argenzio, Robert A

    2002-07-01

    Reports conflict regarding the effect of nitric oxide (NO) on intestinal epithelium. In chronic injury, NO appears detrimental by combining with reactive oxygen to form potent-free radicals. In contrast, inhibition of NO synthesis after acute injury exacerbates damage and inflammation. Recent studies have disclosed constitutive expression of inducible NO synthase (iNOS) by normal intestinal epithelia, yet little attention has been given to the role of iNOS in acute epithelial repair. We studied the local effects of iNOS on early epithelial repair of porcine ileal mucosa injured by deoxycholate within Ussing chambers. iNOS was constitutively expressed by the villous epithelium, and after deoxycholate injury, iNOS was expressed by injured and detaching enterocytes. Selective inhibition of iNOS abolished increases in NO synthesis and villous reepithelialization after injury. Exogenous L-arginine rescued baseline reepithelialization from NOS inhibitors but was only capable of stimulating additional repair in the presence of serum. These results demonstrate that iNOS-derived NO is a key mediator of early villous reepithelialization following acute mucosal injury. PMID:12065303

  14. Effects on mitochondria of mitochondria-induced nitric oxide release from a ruthenium nitrosyl complex.

    PubMed

    Pestana, Cezar R; Phelippin, Daniela P S; Polizello, Ana C M; Dorta, Daniel J; Uyemura, Sergio A; Santos, Antonio C; Doro, Fábio G; Rodrigues, Fernando P; Tfouni, Elia; Curti, Carlos

    2009-02-01

    The ruthenium nitrosyl complex trans-[Ru(NO)(NH(3))(4)(py)](PF(6))(3) (pyNO), a nitric oxide (NO) donor, was studied in regard to the release of NO and its impact both on isolated mitochondria and HepG2 cells. In isolated mitochondria, NO release from pyNO was concomitant with NAD(P)H oxidation and, in the 25-100 microM range, it resulted in dissipation of mitochondrial membrane potential, inhibition of state 3 respiration, ATP depletion and reactive oxygen species (ROS) generation. In the presence of Ca(2+), mitochondrial permeability transition (MPT), an unspecific membrane permeabilization involved in cell necrosis and some types of apoptosis, was elicited. As demonstrated by externalization of phosphatidylserine and activation of caspase-9 and caspase-3, pyNO (50-100 microM) induced HepG2 cell death, mainly by apoptosis. The combined action of the NO itself, the peroxynitrite yielded by NO in the presence of reactive oxygen species (ROS) and the oxidative stress generated by the NAD(P)H oxidation is proposed to be involved in cell death by pyNO, both via respiratory chain inhibition and ROS levels increase, or even via MPT, if Ca(2+) is present. PMID:18950724

  15. Laser induced fluorescence measurements and modeling of nitric oxide in high-pressure premixed flames

    NASA Technical Reports Server (NTRS)

    Reisel, John R.; Laurendeau, Normand M.

    1994-01-01

    Laser-induced fluorescence (LIF) has been applied to the quantitative measurement of nitric oxide (NO) in premixed, laminar, high-pressure flames. Their chemistry was also studied using three current kinetics schemes to determine the predictive capabilities of each mechanism with respect to NO concentrations. The flames studied were low-temperature (1600 less than T less than 1850K) C2H6/O2/N2 and C2H6/O2/N2 flames, and high temperature (2100 less than T less than 2300K) C2H6/O2/N2 flames. Laser-saturated fluorescence (LSF) was initially used to measure the NO concentrations. However, while the excitation transition was well saturated at atmospheric pressure, the fluorescence behavior was basically linear with respect to laser power at pressures above 6 atm. Measurements and calculations demonstrated that the fluorescence quenching rate variation is negligible for LIF measurements of NO at a given pressure. Therefore, linear LIF was used to perform quantitative measurements of NO concentration in these high-pressure flames. The transportability of a calibration factor from one set of flame conditions to another also was investigated by considering changes in the absorption and quenching environment for different flame conditions. The feasibility of performing LIF measurements of (NO) in turbulent flames was studied; the single-shot detection limit was determined to be 2 ppm.

  16. Role of nitric oxide in the radiation-induced bystander effect.

    PubMed

    Yakovlev, Vasily A

    2015-12-01

    Cells that are not irradiated but are affected by "stress signal factors" released from irradiated cells are called bystander cells. These cells, as well as directly irradiated ones, express DNA damage-related proteins and display excess DNA damage, chromosome aberrations, mutations, and malignant transformation. This phenomenon has been studied widely in the past 20 years, since its first description by Nagasawa and Little in 1992, and is known as the radiation-induced bystander effect (RIBE). Several factors have been identified as playing a role in the bystander response. This review will focus on one of them, nitric oxide (NO), and its role in the stimulation and propagation of RIBE. The hydrophobic properties of NO, which permit its diffusion through the cytoplasm and plasma membranes, allow this signaling molecule to easily spread from irradiated cells to bystander cells without the involvement of gap junction intercellular communication. NO produced in irradiated tissues mediates cellular regulation through posttranslational modification of a number of regulatory proteins. The best studied of these modifications are S-nitrosylation (reversible oxidation of cysteine) and tyrosine nitration. These modifications can up- or down-regulate the functions of many proteins modulating different NO-dependent effects. These NO-dependent effects include the stimulation of genomic instability (GI) and the accumulation of DNA errors in bystander cells without direct DNA damage. PMID:26355395

  17. Inhalation of nitric oxide inhibits ADP-induced platelet aggregation and alpha-granule release.

    PubMed

    Hagberg, I A; Sølvik, U Ø; Opdahl, H; Roald, H E; Lyberg, T

    1999-01-01

    To gather further information about the effects on blood platelet activation of in vivo exposure to nitric oxide (NO), platelet reactivity was studied in blood from healthy, non-smoking male volunteers before and after 30 min inhalation of 40 ppm NO. Whole blood was stimulated in vitro with adenosine diphosphate or thrombin receptor activation peptide (TRAP-6). In an ex vivo perfusion model, non-anticoagulated blood was exposed to immobilised collagen at arterial blood flow conditions (2600 s(-1)). Blood samples from both the in vitro and ex vivo experiments were stained with fluorochrome-labelled Annexin-V and antibodies against CD42a, CD45, CD49b, CD61, CD62P and fibrinogen, and analysed with a three-colour flow cytometry technique. NO inhalation reduced the platelet activation response to adenosine diphosphate (ADP) stimulation by decreasing platelet-platelet aggregation, alpha-granule release and platelet-leukocyte conjugate formation. TRAP-stimulated platelet activation, collagen-induced platelet activation and thrombus growth was unaffected by NO inhalation. We therefore suggest an ADP receptor inhibitor mode of action of inhaled NO, selective on the newly suggested G protein- and phospholipase C-coupled P2Y1 receptor. Our results demonstrate that blood platelet activation in healthy subjects is modulated by inhalation of NO in therapeutically relevant doses, although the clinical impact of our findings remains unclear. PMID:16801117

  18. Bacterial Colonization and the Expression of Inducible Nitric Oxide Synthase in Murine Wounds

    PubMed Central

    Mahoney, Eric; Reichner, Jonathan; Robinson Bostom, Leslie; Mastrofrancesco, Balduino; Henry, William; Albina, Jorge

    2002-01-01

    The expression of inducible nitric oxide synthase (iNOS) in two different murine wound models was investigated. Animals were subjected to either full-thickness linear skin incision with subcutaneous implantation of sterile polyvinyl alcohol sponges, or to 1.5 × 1.5-cm dorsal skin excision. Reverse transcriptase-polymerase chain reaction detected iNOS mRNA in all cell samples retrieved from the sponges. Immunoblotting of lysates of inflammatory cells harvested from the sponges failed to detect iNOS protein, and immunohistochemistry of the incisional wound was mildly positive. Inflammatory cells of excisional wounds stained strongly positive for iNOS. Cutaneous wounds were found to be colonized with Staphylococcus aureus. The detection of iNOS in cells from sponges inoculated in vivo with heat-killed bacteria and the reduction of immunohistochemical signal for iNOS in excisional wounds of animals treated with antibiotics support a role of bacteria in the induction of iNOS in wounds. The expression of iNOS in excisional wounds requires interferon-γ and functional lymphocytes because interferon-γ knockout and SCID-Beige mice exhibited attenuated iNOS staining in excisional wounds. The expression of iNOS in the inflammatory cells of murine wounds is a response to bacterial colonization and not part of the normal repair process elicited by sterile tissue injury. PMID:12466130

  19. Nitric oxide in microgravity-induced orthostatic intolerance: relevance to spinal cord injury

    NASA Technical Reports Server (NTRS)

    Vaziri, N. D.; Purdy, R. E. (Principal Investigator)

    2003-01-01

    Prolonged exposure to microgravity results in cardiovascular deconditioning which is marked by orthostatic intolerance in the returning astronauts and recovering bed-ridden patients. Recent studies conducted in our laboratories at University of California, Irvine have revealed marked elevation of nitric oxide (NO) production in the kidney, heart, brain, and systemic arteries coupled with significant reduction of NO production in the cerebral arteries of microgravity-adapted animals. We have further demonstrated that the observed alteration of NO metabolism is primarily responsible for the associated cardiovascular deconditioning. Recovery from acute spinal cord injury (SCI) is frequently complicated by orthostatic intolerance that is due to the combined effects of the disruption of efferent sympathetic pathway and cardiovascular deconditioning occasioned by prolonged confinement to bed. In this presentation, I will review the nature of altered NO metabolism and its role in the pathogenesis of microgravity-induced cardiovascular deconditioning. The possible relevance of the new findings to orthostatic intolerance in patients with acute SCI and its potential therapeutic implications will be discussed.

  20. Simulated longitudinal variations in the lower thermospheric nitric oxide induced by nonmigrating tides

    NASA Astrophysics Data System (ADS)

    Ren, Zhipeng; Wan, Weixing; Liu, Libo; Xiong, Jiangang

    2011-04-01

    On the basis of the GCITEM-IGGCAS model and tides from TIMED/SABER observations, the longitudinal variations in the lower thermosphere nitric oxide (NO), which is induced by nonmigrating tides, are investigated. We simulate the intra-annual variation of the NO density and find that equinoctial lower thermospheric NO density shows an obvious wave number 4 longitudinal structure both in equinox and in June solstice and a wave number 3 longitudinal structure in December solstice. These simulation results are consistent with the longitudinal variation observed by Oberheide and Forbes (2008b). The simulations support that the wave number 4 structure in NO density is mainly driven by the eastward propagating nonmigrating diurnal tide with zonal wave number 3, and the wave number 3 structure is mainly driven by the eastward propagating nonmigrating diurnal tide with zonal wave number 2. Our simulations also show that the NO density residuals and the neutral mass density residuals in the height range between 90 and 120 km agree well with each other, and the neutral mass density mainly affects the longitudinal variations of lower thermospheric NO density through modulation of the chemical production rate, e.g., through affecting the chemical reaction between excited nitrogen and molecular oxygen.

  1. Inhibition of inducible nitric oxide synthase in the human intestinal epithelial cell line, DLD-1, by the inducers of heme oxygenase 1, bismuth salts, heme, and nitric oxide donors

    PubMed Central

    Cavicchi, M; Gibbs, L; Whittle, B

    2000-01-01

    BACKGROUND—The inducible isoform of nitric oxide synthase (iNOS) may be involved in the mucosal injury associated with inflammatory bowel disease (IBD). In contrast with iNOS, the inducible heme oxygenase 1 (HO-1) is considered to act as a protective antioxidant system.
AIMS—To evaluate the effects of the known HO-1 inducers, cadmium and bismuth salts, heme, and nitric oxide (NO) donors, on iNOS activity, and expression in the human intestinal epithelial cell line DLD-1.
METHODS—iNOS activity was assessed by the Griess reaction and the radiochemical L-arginine conversion assay. iNOS mRNA and iNOS protein expression were determined by northern and western blotting, respectively.
RESULTS—Cytokine exposure led to induction of iNOS activity, iNOS mRNA, and iNOS protein expression. Preincubation of DLD-1 cells with heme (1-50 µM) inhibited cytokine induced iNOS activity in a concentration dependent manner. This inhibitory effect was abolished by the HO-1 specific inhibitor tin protoporphyrin. Preincubation with NO donors sodium nitroprusside (SNP 1-1000 µM) or S-nitroso-acetyl-penicillamine (SNAP 1-1000 µM), or with the heavy metals cadmium chloride (10-40 µM), bismuth citrate, or ranitidine bismuth citrate (10-3000 µM) inhibited iNOS activity in a concentration dependent manner. Moreover, SNP and heme abolished cytokine induced iNOS protein as well as iNOS mRNA expression, whereas cadmium chloride did not modify iNOS protein expression.
CONCLUSIONS—Heme, the heavy metals cadmium and bismuth, as well as NO donors, are potent inhibitors of cytokine induced iNOS activity. Heme and NO donors act at the transcriptional level inhibiting iNOS mRNA expression. Such findings suggest the potential for interplay between the iNOS and HO-1 systems, which may modulate the progress of IBD.


Keywords: inducible nitric oxide synthase; nitric oxide; colonic epithelial cells; cytokines; heme oxygenase-1; bismuth citrate PMID:11076874

  2. Involvement of prostaglandin I(2) in nitric oxide-induced vasodilation of retinal arterioles in rats.

    PubMed

    Mori, Asami; Namekawa, Ryo; Hasebe, Masami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2015-10-01

    The soluble guanylyl cyclase/cGMP system plays an important role in the vasodilator response to nitric oxide (NO) in various vascular beds. However, in rat retinal arterioles, the cyclooxygenase-1/cAMP-mediated pathway contributes to the vasodilator effects of NO, although the specific prostanoid involved remains to be elucidated. In the present study, we investigated the role of prostaglandin I2 and its receptor (prostanoid IP receptor) system in NO-induced vasodilation of rat retinal arterioles in vivo. Fundus images were captured using a digital camera that was equipped with a special objective lens. Changes in diameter of retinal arterioles were assessed. The NO donor (±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR3) increased the diameter of retinal arterioles but decreased systemic blood pressure in a dose-dependent manner. Treatment of rats with indomethacin, a non-selective cyclooxygenase inhibitor, markedly attenuated the retinal vasodilator, but not depressor responses to NOR3. The prostanoid IP receptor antagonist 4,5-dihydro-N-[4-[[4-(1-methylethoxy)phenyl]methyl]phenyl]-1H-imadazol-2-amine (CAY10441), and the prostaglandin I2 synthase inhibitor 9α,11α-azoprosta-5Z,13E-dien-1-oic acid (U-51605), both showed similar preventive effects against the NOR3-induced retinal vasodilator response. Neither CAY10441 nor U-51605 showed any significant effects on the depressor response to NOR3. NOR3 enhanced the release of prostaglandin I2 from cultured human retinal microvascular endothelial cells and the NOR3-induced prostaglandin I2 release was almost completely abolished by the cyclooxygenase-1 inhibitor SC-560, but not by the cyclooxygenase-2 inhibitor NS-398. However, NOR3 did not increase the release of prostaglandin I2 from human intestinal microvascular endothelial cells. These results suggest that NO exerts its dilatory effect via cyclooxygenase-1/prostaglandin I2/prostanoid IP receptor signaling mechanisms in the retinal vasculature. PMID

  3. Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

    PubMed Central

    Bozic, Iva; Savic, Danijela; Jovanovic, Marija; Bjelobaba, Ivana; Laketa, Danijela; Nedeljkovic, Nadezda; Stojiljkovic, Mirjana; Pekovic, Sanja; Lavrnja, Irena

    2015-01-01

    Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM) modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM) to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS) stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation. PMID:26413464

  4. Involvement of nitric oxide in iodine deficiency-induced microvascular remodeling in the thyroid gland: role of nitric oxide synthase 3 and ryanodine receptors.

    PubMed

    Craps, J; Wilvers, C; Joris, V; De Jongh, B; Vanderstraeten, J; Lobysheva, I; Balligand, J-L; Sonveaux, P; Gilon, P; Many, M-C; Gérard, A-C; Colin, I M

    2015-02-01

    Iodine deficiency (ID) induces microvascular changes in the thyroid gland via a TSH-independent reactive oxygen species-hypoxia inducible factor (HIF)-1α-vascular endothelial growth factor (VEGF) pathway. The involvement of nitric oxide (NO) in this pathway and the role of calcium (Ca(2+)) and of ryanodine receptors (RYRs) in NO synthase 3 (NOS3) activation were investigated in a murine model of goitrogenesis and in 3 in vitro models of ID, including primary cultures of human thyrocytes. ID activated NOS3 and the production of NO in thyrocytes in vitro and increased the thyroid blood flow in vivo. Using bevacizumab (a blocking antibody against VEGF-A) in mice, it appeared that NOS3 is activated upstream of VEGF-A. L-nitroarginine methyl ester (a NOS inhibitor) blocked the ID-induced increase in thyroid blood flow in vivo and NO production in vitro, as well as ID-induced VEGF-A mRNA and HIF-1α expression in vitro, whereas S-nitroso-acetyl-penicillamine (a NO donor) did the opposite. Ca(2+) is involved in this pathway as intracellular Ca(2+) flux increased after ID, and thapsigargin activated NOS3 and increased VEGF-A mRNA expression. Two of the 3 known mammalian RYR isoforms (RYR1 and RYR2) were shown to be expressed in thyrocytes. RYR inhibition using ryanodine at 10μM decreased ID-induced NOS3 activation, HIF-1α, and VEGF-A expression, whereas RYR activation with ryanodine at 1nM increased NOS3 activation and VEGF-A mRNA expression. In conclusion, during the early phase of TSH-independent ID-induced microvascular activation, ID sequentially activates RYRs and NOS3, thereby supporting ID-induced activation of the NO/HIF-1α/VEGF-A pathway in thyrocytes. PMID:25406019

  5. Expression of inducible nitric oxide synthase in rat pulmonary Cryptococcus neoformans granulomas.

    PubMed Central

    Goldman, D.; Cho, Y.; Zhao, M.; Casadevall, A.; Lee, S. C.

    1996-01-01

    Rats, like humans, have extremely effective immune mechanisms for controlling pulmonary Cryptococcus neoformans infection. The mechanism(s) responsible for efficient immunity in rat experimental infection is unknown. Recently, induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) have been implicated as an important microbicidal mechanism by which activated macrophages effect cytotoxicity against microbes. In this report, we investigated the expression of iNOS in rat pulmonary cryptococcosis. Localization and regulation of NO production was studied by immunohistochemistry for iNOS in conjunction with immunohistochemistry for cell markers, cytokines, and cryptococcal capsular polysaccharide. iNOS immunoreactivity was detected in macrophages, neutrophils, vascular endothelium, and respiratory epithelium. Double-immunolabeling studies revealed that the most prominent iNOS immunoreactivity was localized to epithelioid macrophages (CD11b/c+) within granulomas; CD4+ and CD8+ T cells were numerous around granulomas but did not express iNOS. iNOS immunoreactivity was detected in a selective population of epithelioid macrophages within some granulomas but not others. iNOS- granulomas were identical to iNOS+ granulomas with respect to morphology and immunohistochemical profiles. Macrophage iNOS immunoreactivity was detected 1 week after infection in one out of four rats and was strongly expressed in all rats at 2 weeks (in up to 50 percent of the granulomas) but declined considerably by 25 days. iNOS expression coincided with granuloma formation and preceded a decrease in lung fungal burden, suggesting an anticryptococcal role for NO. By double labeling, cytokines that have been shown to promote (interferon-gamma, granulocyte/macrophage colony-stimulating factor) and inhibit (transforming growth factor-beta) macrophage iNOS expression were detected around iNOS+ granuloma. iNOS immunoreactivity was expressed in selected neutrophils (1 and 2 weeks) and

  6. A Cytokine Signalling Network for the Regulation of Inducible Nitric Oxide Synthase Expression in Rheumatoid Arthritis.

    PubMed

    Dey, Poulami; Panga, Venugopal; Raghunathan, Srivatsan

    2016-01-01

    In rheumatoid arthritis (RA), nitric oxide (NO) is implicated in inflammation, angiogenesis and tissue destruction. The enzyme inducible nitric oxide synthase (iNOS) is responsible for the localised over-production of NO in the synovial joints affected by RA. The pro- and anti-inflammatory cytokines stimulate the synovial macrophages and the fibroblast-like synoviocytes to express iNOS. Therefore, the cytokine signalling network underlying the regulation of iNOS is essential to understand the pathophysiology of the disease. By using information from the literature, we have constructed, for the first time, the cytokine signalling network involved in the regulation of iNOS expression. Using the differential expression patterns obtained by re-analysing the microarray data on the RA synovium and the synovial macrophages available in the Gene Expression Omnibus (GEO) database, we aimed to establish the role played by the network genes towards iNOS regulation in the RA synovium. Our analysis reveals that the network genes belonging to interferon (IFN) and interleukin-10 (IL-10) pathways are always up-regulated in the RA synovium whereas the genes which are part of the anti-inflammatory transforming growth factor-beta (TGF-β) signalling pathway are mostly down-regulated. We observed a consistent up-regulation of the transcription factor signal transducers and activators of transcription 1 (STAT1) in the RA synovium and the macrophages. Interestingly, we found a consistent up-regulation of the iNOS interacting protein ras-related C3 botulinum toxin substrate 2 (RAC2) in the RA synovium as well as the macrophages. Importantly, we have constructed a model to explain the impact of IFN and IL-10 pathways on Rac2-iNOS interaction leading to over-production of NO and thereby causing chronic inflammation in the RA synovium. The interplay between STAT1 and RAC2 in the regulation of NO could have implications for the identification of therapeutic targets for RA. PMID:27626941

  7. Calcium-binding sites of calmodulin and electron transfer by inducible nitric oxide synthase.

    PubMed

    Gribovskaja, Irena; Brownlow, Kaleb C; Dennis, Sam J; Rosko, Andrew J; Marletta, Michael A; Stevens-Truss, Regina

    2005-05-24

    Like that of the neuronal nitric oxide synthase (nNOS), the binding of Ca(2+)-bound calmodulin (CaM) also regulates the activity of the inducible isoform (iNOS). However, the role of each of the four Ca(2+)-binding sites of CaM in the activity of iNOS is unclear. Using a series of single-point mutants of Drosophila melanogaster CaM, the effect that mutating each of the Ca(2+)-binding sites plays in the transfer of electrons within iNOS has been examined. The same Glu (E) to Gln (Q) mutant series of CaM used previously [Stevens-Truss, R., Beckingham, K., and Marletta, M. A. (1997) Biochemistry 36, 12337-12345] to study the role of the Ca(2+)-binding sites in the activity of nNOS was used for these studies. We demonstrate here that activity of iNOS is dependent on Ca(2+) being bound to sites II (B2Q) and III (B3Q) of CaM. Nitric oxide ((*)NO) producing activity (as measured using the hemoglobin assay) of iNOS bound to the B2Q and B3Q CaMs was found to be 41 and 43% of the wild-type activity, respectively. The site I (B1Q) and site IV (B4Q) CaM mutants only minimally affected (*)NO production (95 and 90% of wild-type activity, respectively). These results suggest that NOS isoforms, although all possessing a prototypical CaM binding sequence and requiring CaM for activity, interact with CaM differently. Moreover, iNOS activation by CaM, like nNOS, is not dependent on Ca(2+) being bound to all four Ca(2+)-binding sites, but has specific and distinct requirements. This novel information, in addition to helping us understand NOS, should aid in our understanding of CaM target activation. PMID:15896003

  8. Nitric Oxide-Induced Apoptosis of Human Dental Pulp Cells Is Mediated by the Mitochondria-Dependent Pathway

    PubMed Central

    Park, Min Young; Jeong, Yeon Jin; Kang, Gi Chang; Kim, Mi-Hwa; Kim, Sun Hun; Chung, Hyun-Ju

    2014-01-01

    Nitric oxide (NO) is recognized as a mediator and regulator of inflammatory responses. NO is produced by nitric oxide synthase (NOS), and NOS is abundantly expressed in the human dental pulp cells (HDPCs). NO produced by NOS can be cytotoxic at higher concentrations to HDPCs. However, the mechanism by which this cytotoxic pathway is activated in cells exposed to NO is not known. The purpose of this study was to elucidate the NO-induced cytotoxic mechanism in HDPCs. Sodium nitroprusside (SNP), a NO donor, reduced the viability of HDPCs in a dose- and time-dependent manner. We investigated the in vitro effects of nitric oxide on apoptosis of cultured HDPCs. Cells showed typical apoptotic morphology after exposure to SNP. Besides, the number of Annexin V positive cells was increased among the SNP-treated HDPCs. SNP enhanced the production of reactive oxygen species (ROS), and N-acetylcysteine (NAC) ameliorated the decrement of cell viability induced by SNP. However, a soluble guanylate cyclase inhibitor (ODQ) did not inhibited the decrement of cell viability induced by SNP. SNP increased cytochrome c release from the mitochondria to the cytosol and the ratio of Bax/Bcl-2 expression levels. Moreover, SNP-treated HDPCs elevated activities of caspase-3 and caspase-9. While pretreatment with inhibitors of caspase (z-VAD-fmk, z-DEVD-fmk) reversed the NO-induced apoptosis of HDPCs. From these results, it can be suggested that NO induces apoptosis of HDPCs through the mitochondria-dependent pathway mediated by ROS and Bcl-2 family, but not by the cyclic GMP pathway. PMID:24634593

  9. Adaptative nitric oxide overproduction in perivascular adipose tissue during early diet-induced obesity.

    PubMed

    Gil-Ortega, Marta; Stucchi, Paula; Guzmán-Ruiz, Rocío; Cano, Victoria; Arribas, Silvia; González, M Carmen; Ruiz-Gayo, Mariano; Fernández-Alfonso, Maria S; Somoza, Beatriz

    2010-07-01

    Perivascular adipose tissue (PVAT) plays a paracrine role in regulating vascular tone. We hypothesize that PVAT undergoes adaptative mechanisms during initial steps of diet-induced obesity (DIO) which contribute to preserve vascular function. Four-week-old male C57BL/6J mice were assigned either to a control [low-fat (LF); 10% kcal from fat] or to a high-fat diet (HF; 45% kcal from fat). After 8 wk of dietary treatment vascular function was analyzed in the whole perfused mesenteric bed (MB) and in isolated mesenteric arteries cleaned of PVAT. Relaxant responses to acetylcholine (10(-9)-10(-4) m) and sodium nitroprusside (10(-12)-10(-5) m) were significantly ameliorated in the whole MB from HF animals. However, there was no difference between HF and LF groups in isolated mesenteric arteries devoid of PVAT. The enhancement of relaxant responses detected in HF mice was not attributable to an increased release of nitric oxide (NO) from the endothelium nor to an increased sensitivity and/or activity of muscular guanilylcyclase. Mesenteric PVAT of HF animals showed an increased bioavailability of NO, detected by 4,5-diaminofluorescein diacetate (DAF2-DA) staining, which positively correlated with plasma leptin levels. DAF-2DA staining was absent in PVAT from ob/ob mice but was detected in these animals after 4-wk leptin replacement. The main finding in this study is that adaptative NO overproduction occurs in PVAT during early DIO which might be aimed at preserving vascular function. PMID:20410199

  10. Mice Lacking Inducible Nitric Oxide Synthase Demonstrate Impaired Killing of Porphyromonas gingivalis

    PubMed Central

    Gyurko, Robert; Boustany, Gabriel; Huang, Paul L.; Kantarci, Alpdogan; Van Dyke, Thomas E.; Genco, Caroline A.; Gibson III, Frank C.

    2003-01-01

    Porphyromonas gingivalis is a primary etiological agent of generalized severe periodontitis, and emerging data suggest the importance of reactive oxygen and nitrogen species in periodontal tissue damage, as well as in microbial killing. Since nitric oxide (NO) released from inducible NO synthase (iNOS) has been shown to possess immunomodulatory, cytotoxic, and antibacterial effects in experimental models, we challenged iNOS-deficient (iNOS−/−) mice with P. gingivalis by using a subcutaneous chamber model to study the specific contribution of NO to host defense during P. gingivalis infection. iNOS−/− mice inoculated with P. gingivalis developed skin lesions and chamber rejection with higher frequency and to a greater degree than similarly challenged C57BL/6 wild-type (WT) mice. Chamber fluid from iNOS−/− mice possessed significantly more P. gingivalis than that of WT mice. The immunoglobulin G responses to P. gingivalis in serum was similar in WT and iNOS−/− mice, and the inductions of tumor necrosis factor alpha, interleukin-1β and interleukin-6, and prostaglandin E2 were comparable between the two mouse strains. Although no differences in total leukocyte counts in chamber fluids were observed between iNOS−/− and WT mice, the percentage of dead polymorphonuclear leukocytes (PMNs) was significantly greater in iNOS−/− mouse chamber fluids than that of WT samples. Interestingly, casein-elicited PMNs from iNOS−/− mice released more superoxide than did WT PMNs when stimulated with P. gingivalis. These results indicate that modulation of superoxide levels is a mechanism by which NO influences PMN function and that NO is an important element of the host defense against P. gingivalis. PMID:12933833

  11. Inducible nitric oxide synthetase genotype and Helicobacter pylori infection affect gastric cancer risk

    PubMed Central

    Rafiei, Alireza; Hosseini, Vahid; Janbabai, Ghasem; Fazli, Bahman; Ajami, Abulghasem; Hosseini-khah, Zahra; Gilbreath, Jeremy; Merrell, D Scott

    2012-01-01

    AIM: To investigate the association of the inducible nitric oxide synthetase (iNOS) C150T polymorphism with Helicobacter pylori (H. pylori) infection and gastric cancer (GC) risk in Iran. METHODS: In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T iNOS polymorphism was genotyped by polymerase chain reaction (PCR) and restriction digestion. Patients were grouped by cancer presence, demographic and behavior characteristics, and H. pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS: In this population, we found that smoking, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development (P = 0.015, P < 0.001, P = 0.0034, and P < 0.015, respectively). The distribution of the C150T iNOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-H. pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio (OR) = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC (OR = 5.0, P = 0.029). In contrast, this association was not seen in patients in the control group. CONCLUSION: A CT or TT polymorphism at position 150 in the iNOS gene significantly increases the risk of GC and may be a marker for GC susceptibility. PMID:23002365

  12. Nitric Oxide Induction of Parkin Translocation in PTEN-induced Putative Kinase 1 (PINK1) Deficiency

    PubMed Central

    Han, Ji-Young; Kang, Min-Ji; Kim, Kyung-Hee; Han, Pyung-Lim; Kim, Hyun-Seok; Ha, Ji-Young; Son, Jin H.

    2015-01-01

    The failure to trigger mitophagy is implicated in the pathogenesis of familial Parkinson disease that is caused by PINK1 or Parkin mutations. According to the prevailing PINK1-Parkin signaling model, mitophagy is promoted by the mitochondrial translocation of Parkin, an essential PINK1-dependent step that occurs via a previously unknown mechanism. Here we determined that critical concentrations of NO was sufficient to induce the mitochondrial translocation of Parkin even in PINK1 deficiency, with apparent increased interaction of full-length PINK1 accumulated during mitophagy, with neuronal nitric oxide synthase (nNOS). Specifically, optimum levels of NO enabled PINK1-null dopaminergic neuronal cells to regain the mitochondrial translocation of Parkin, which appeared to be significantly suppressed by nNOS-null mutation. Moreover, nNOS-null mutation resulted in the same mitochondrial electron transport chain (ETC) enzyme deficits as PINK1-null mutation. The involvement of mitochondrial nNOS activation in mitophagy was further confirmed by the greatly increased interactions of full-length PINK1 with nNOS, accompanied by mitochondrial accumulation of phospho-nNOS (Ser1412) during mitophagy. Of great interest is that the L347P PINK1 mutant failed to bind to nNOS. The loss of nNOS phosphorylation and Parkin accumulation on PINK1-deficient mitochondria could be reversed in a PINK1-dependent manner. Finally, non-toxic levels of NO treatment aided in the recovery of PINK1-null dopaminergic neuronal cells from mitochondrial ETC enzyme deficits. In summary, we demonstrated the full-length PINK1-dependent recruitment of nNOS, its activation in the induction of Parkin translocation, and the feasibility of NO-based pharmacotherapy for defective mitophagy and ETC enzyme deficits in Parkinson disease. PMID:25716315

  13. Nitric oxide induces stomatal closure and enhances the adaptive plant responses against drought stress.

    PubMed

    García-Mata, C; García Mata, C; Lamattina, L

    2001-07-01

    Nitric oxide (NO) is a very active molecule involved in many and diverse biological pathways where it has proved to be protective against damages provoked by oxidative stress conditions. In this work, we studied the effect of two NO donors, sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine SNP-treated on the response of wheat (Triticum aestivum) to water stress conditions. After 2 and 3 h of drought, detached wheat leaves pretreated with 150 microM SNP retained up to 15% more water than those pretreated with water or NO(2)(-)/NO(3)(-). The effect of SNP treatment on water retention was also found in wheat seedlings after 7 d of drought. These results were consistent with a 20% decrease in the transpiration rate of SNP-treated detached wheat leaves for the same analyzed time. In parallel experiments, NO was also able to induce a 35%, 30%, and 65% of stomatal closure in three different species, Tradescantia sp. (monocotyledonous) and two dicotyledonous, Salpichroa organifolia and fava bean (Vicia faba), respectively. In SNP-treated leaves of Tradescantia sp., the stomatal closure was correlated with a 10% increase on RWC. Ion leakage, a cell injury index, was 25% lower in SNP-treated wheat leaves compared with control ones after the recovery period. Carboxy-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), a specific NO scavenger, reverted SNP action by restoring the transpiration rate, stomatal aperture, and the ion leakage to the level found in untreated leaves. Northern-blot analysis showed that SNP-treated wheat leaves display a 2-fold accumulation of a group three late embryogenesis abundant transcript with respect to control leaves both after 2 and 4 h of drought periods. All together, these results suggest that the exogenous application of NO donors might confer an increased tolerance to severe drought stress conditions in plants. PMID:11457969

  14. Troglitazone regulates peroxisome proliferator-activated receptors and inducible nitric oxide synthase in murine ovarian macrophages.

    PubMed

    Minge, Cadence E; Ryan, Natalie K; Van Der Hoek, Kylie H; Robker, Rebecca L; Norman, Robert J

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma (PPARG) and PPAR-alpha (PPARA) control metabolic processes in many cell types and act as anti-inflammatory regulators in macrophages. PPAR-activating ligands include thiazolidinediones (TZDs), such as troglitazone, once frequently used to treat insulin resistance as well as symptoms of polycystic ovary syndrome (PCOS). Since macrophages within the ovary mediate optimal follicle development, TZD actions to improve PCOS symptoms are likely to be partly mediated through these specifically localized immune cells. In mouse ovary, PPARG protein was expressed in granulosa cells and in isolated cells localized to theca, stroma, and corpora lutea, consistent with EMR1+ macrophages. Isolation of immune cells (EMR1+ or H2+) showed that Pparg and Ppara were expressed in ovarian macrophages at much higher levels than in peritoneal macrophages. Ovulatory human chorionic gonadotropin downregulated expression of Pparg and Ppara in EMR1+ ovarian macrophages, but no hormonal responsiveness was observed in H2+ cells. Downstream anti-inflammatory effects of PPARG activation were analyzed by in vitro treatment of isolated macrophages with troglitazone. Interleukin-1 beta (Il1b) expression was not altered, and tumor necrosis factor-alpha (Tnf) expression was affected in peritoneal macrophages only. In ovarian macrophages, inducible nitric oxide synthase (Nos2), an important proinflammatory enzyme that regulates ovulation, was significantly reduced by troglitazone treatment, an effect that was restricted to cells from the preovulatory ovary. Thus, expression of PPARs within ovarian macrophages is hormonally regulated, reflecting the changing roles of these cells during the ovulatory cycle. Additionally, ovarian macrophages respond directly to troglitazone to downregulate expression of proinflammatory Nos2, providing mechanistic information about ovarian effects of TZD treatment. PMID:16192401

  15. Dipyridamole enhances ischaemia-induced arteriogenesis through an endocrine nitrite/nitric oxide-dependent pathway

    PubMed Central

    Venkatesh, Prasanna K.; Pattillo, Christopher B.; Branch, Billy; Hood, Jay; Thoma, Steven; Illum, Sandra; Pardue, Sibile; Teng, Xinjun; Patel, Rakesh P.; Kevil, Christopher G.

    2010-01-01

    Aims Anti-platelet agents, such as dipyridamole, have several clinical benefits for peripheral artery disease with the speculation of angiogenic potential that could preserve ischaemic tissue viability, yet the effect of dipyridamole on ischaemic arteriogenesis or angiogenesis is unknown. Here we test the hypothesis that dipyridamole therapy augments arteriolar vessel development and function during chronic ischaemia. Methods and results Mice were treated with 200 mg/kg dipyridamole twice daily to achieve therapeutic plasma levels (0.8–1.2 µg/mL). Chronic hindlimb ischaemia was induced by permanent femoral artery ligation followed by measurement of tissue perfusion using laser Doppler blood flow along with quantification of vascular density, cell proliferation, and activation of nitric oxide (NO) metabolism. Dipyridamole treatment quickly restored ischaemic hindlimb blood flow, increased vascular density and cell proliferation, and enhanced collateral artery perfusion compared with control treatments. The beneficial effects of dipyridamole on blood flow and vascular density were dependent on NO production as dipyridamole did not augment ischaemic tissue reperfusion, vascular density, or endothelial cell proliferation in endothelial NO synthase (eNOS)-deficient mice. Blood and tissue nitrite levels were significantly higher in dipyridamole-treated mice compared with controls and eNOS−/− mice, verifying increased NO production that was regulated in a PKA-dependent manner. Conclusion Dipyridamole augments nitrite/NO production, leading to enhanced arteriogenesis activity and blood perfusion in ischaemic limbs. Together, these data suggest that dipyridamole can augment ischaemic vessel function and restore blood flow, which may be beneficial in peripheral artery disease. PMID:20061326

  16. Inducible nitric oxide synthase (iNOS) regulatory region variation in non-human primates

    PubMed Central

    Roodgar, Morteza; Ross, Cody T.; Kenyon, Nicholas J.; Marcelino, Gretchen; Smith, David Glenn

    2015-01-01

    Inducible nitric oxide synthase (iNOS) is an enzyme that plays a key role in intracellular immune response against respiratory infections. Since various species of nonhuman primates exhibit different levels of susceptibility to infectious respiratory diseases, and since variation in regulatory regions of genes is thought to play a key role in expression levels of genes, two candidate regulatory regions of iNOS were mapped, sequenced, and compared across five species of nonhuman primates: African green monkeys (chlorocebus sabeus), pig-tailed macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), Indian rhesus macaques (Macaca mulatta), and Chinese rhesus macaques (M. mulatta). In addition, we conducted an in silico analysis of the transcription factor binding sites associated with genetic variation in these two candidate regulatory regions across species. We found that only one of the two candidate regions showed strong evidence of involvement in iNOS regulation. Specifically, we found evidence of 13 conserved binding site candidates linked to iNOS regulation: AP-1, C/EBPB, CREB, GATA-1, GATA-3, NF-AT, NF-AT5, NF-κB, KLF4, Oct-1, PEA3, SMAD3, and TCF11. Additionally, we found evidence of interspecies variation in binding sites for several regulatory elements linked to iNOS (GATA-3, GATA-4, KLF6, SRF, STAT-1, STAT-3, OLF-1 and HIF-1) across species, especially in African green monkeys relative to other species. Given the key role of iNOS in respiratory immune response, the findings of this study might help guide the direction of future studies aimed to uncover the molecular mechanisms underlying the increased susceptibility of African green monkeys to several viral and bacterial respiratory infections. PMID:25675838

  17. Nitric oxide is involved in methyl jasmonate-induced defense responses and secondary metabolism activities of Taxus cells.

    PubMed

    Wang, Jian Wen; Wu, Jian Yong

    2005-06-01

    Methyl jasmonate (MeJA), a methyl ester of jasmonic acid (JA), is a well-established signal molecule in plant defense responses and an effective inducer of secondary metabolite accumulation in plant cell cultures such as the valuable anticancer diterpenoid taxol (paclitaxel) in Taxus spp. This work examines the involvement of nitric oxide (NO) in MeJA-induced plant defense responses and secondary metabolism in Taxus chinensis cell cultures. Exogenously supplied MeJA at 100 microM induced rapid production of NO in the Taxus cell cultures, reaching a maximum within 6 h of MeJA supply. Several other responses occurred concomitantly, including the production of hydrogen peroxide (H2O2), and the increases in intracellular malondialdehyde (MDA) content, lipoxygenase (LOX) and phenylalanine ammonium-lyase (PAL) activities. The MeJA-induced H2O2 production was suppressed by an NO donor, sodium nitroprusside (SNP), but enhanced by NO inhibitors, N (omega)-nitro-L-arginine (L-NNA) and 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO). In contrast, the MeJA-induced MDA, LOX and PAL were all enhanced by the NO donor but suppressed by the NO inhibitors. The NO inhibitors also suppressed MeJA-induced taxol accumulation. These results are suggestive of a role for NO as a signal element for activating the MeJA-induced defense responses and secondary metabolism activities of plant cells. PMID:15829512

  18. Selective inhibition of human inducible nitric oxide synthase by S-alkyl-L-isothiocitrulline-containing dipeptides.

    PubMed

    Park, J M; Higuchi, T; Kikuchi, K; Urano, Y; Hori, H; Nishino, T; Aoki, J; Inoue, K; Nagano, T

    2001-04-01

    The aim of this study was to investigate the structure-activity relationship of S-alkyl-L-isothiocitrulline-containing dipeptides towards three partially purified recombinant human nitric oxide synthase (NOS) isozymes, as well as the effects of these compounds on cytokine-induced NO production by human DLD-1 cells. In an in vitro assay, S-methyl-L-isothiocitrulline (L-MIT) was slightly selective for human neuronal NOS (nNOS) over the inducible (iNOS) or endothelial (eNOS) isozyme, but the combination of a hydrophobic L-amino acid (L-Phe, L-Leu or L-Trp) with L-MIT dramatically altered the inhibition pattern to give selective iNOS inhibitors. Introduction of a hydroxy, nitro, amino or methoxy group at the para position of the aromatic ring of L-MIT-L-Phe (MILF) decreased the selectivity and inhibitory potency. A longer or larger S-alkyl group also decreased the selectivity and potency. Dixon analysis showed that all of the dipeptides were competitive inhibitors of the three isoforms of human NOS. The enzymatic time course curves indicated that MILF was a slow binding inhibitor of human iNOS. These results suggest that the human NOS isozymes have different-sized cavities in the binding site near the position to which the C-terminal of L-arginine binds, and the cavity of iNOS is hydrophobic. Interestingly, L-MIT-D-Phe (MIDF) showed little inhibitory activity or selectivity, suggesting that the cavity of human iNOS is located in a well-defined direction from the alpha carbon atom. NO production in cytokine-stimulated human DLD-1 cells was measured with a fluorescent indicator, DAF-FM. MILF, L-MIT-L-Trp(-CHO) (MILW) and L-MIT-L-Tyr (MILY) showed more potent activity than L-MIT in this whole-cell assay. Thus, S-alkyl-L-isothiocitrulline-containing dipeptides are selective inhibitors of human iNOS, and work efficiently in cell-based assay. PMID:11309260

  19. Selective inhibition of human inducible nitric oxide synthase by S-alkyl-L-isothiocitrulline-containing dipeptides

    PubMed Central

    Park, Jung-Min; Higuchi, Tsunehiko; Kikuchi, Kazuya; Urano, Yasuteru; Hori, Hiroyuki; Nishino, Takeshi; Aoki, Junken; Inoue, Keizo; Nagano, Tetsuo

    2001-01-01

    The aim of this study was to investigate the structure-activity relationship of S-alkyl-L-isothiocitrulline-containing dipeptides towards three partially purified recombinant human nitric oxide synthase (NOS) isozymes, as well as the effects of these compounds on cytokine-induced NO production by human DLD-1 cells.In an in vitro assay, S-methyl-L-isothiocitrulline (L-MIT) was slightly selective for human neuronal NOS (nNOS) over the inducible (iNOS) or endothelial (eNOS) isozyme, but the combination of a hydrophobic L-amino acid (L-Phe, L-Leu or L-Trp) with L-MIT dramatically altered the inhibition pattern to give selective iNOS inhibitors. Introduction of a hydroxy, nitro, amino or methoxy group at the para position of the aromatic ring of L-MIT-L-Phe (MILF) decreased the selectivity and inhibitory potency. A longer or larger S-alkyl group also decreased the selectivity and potency. Dixon analysis showed that all of the dipeptides were competitive inhibitors of the three isoforms of human NOS. The enzymatic time course curves indicated that MILF was a slow binding inhibitor of human iNOS.These results suggest that the human NOS isozymes have different-sized cavities in the binding site near the position to which the C-terminal of L-arginine binds, and the cavity of iNOS is hydrophobic. Interestingly, L-MIT-D-Phe (MIDF) showed little inhibitory activity or selectivity, suggesting that the cavity of human iNOS is located in a well-defined direction from the α carbon atom.NO production in cytokine-stimulated human DLD-1 cells was measured with a fluorescent indicator, DAF-FM. MILF, L-MIT-L-Trp(-CHO) (MILW) and L-MIT-L-Tyr (MILY) showed more potent activity than L-MIT in this whole-cell assay.Thus, S-alkyl-L-isothiocitrulline-containing dipeptides are selective inhibitors of human iNOS, and work efficiently in cell-based assay. PMID:11309260

  20. Effects of chronic nitric oxide synthase inhibition in cold-restraint and ethanol-induced gastric mucosal damage in rats.

    PubMed

    Qiu, B S; Pfeiffer, C J; Cho, C H

    1996-01-01

    Gastric actions of Nw-nitro-1-arginine methyl ester (L-NAME) were investigated in rats, as this agent is a reliable nitric oxide synthase inhibitor L-NAME solutions were placed in subcutaneous osmotic minipumps which continuously released L-NAME at 0.1, 1.0, 10, or 40 mg/kg/day. L-NAME dose and time-dependently enhanced stress-induced gastric ulceration but did not affect mucosal mast cell population. Ulcerogenic actions of L-NAME were reversed by L-arginine but not by D-arginine. Ten L-NAME treatment also enhanced the ethanol-induced gastric mucosal damage, depressed gastric mucosal blood flow but did not alter gastric mucus, secretory volume, or acid output. It is concluded that in the present models, chronic nitric oxide synthase inhibition enhanced ulcerogenesis by decreasing mucosal resistance due to reduced mucosal blood perfusion. This implicates nitric oxide as a mucosal defense factor which acts in part by maintaining mucosal blood flow. PMID:8626050

  1. Nitric oxide induces rapid, calcium-dependent release of vesicular glutamate and ATP from cultured rat astrocytes.

    PubMed

    Bal-Price, Anna; Moneer, Zahid; Brown, Guy C

    2002-12-01

    Nitric oxide (NO; 1 microM) or an NO donor (500 microM diethylenetriamine-nitric oxide, DETA-NONOate) caused rapid glutamate and ATP release from cultured rat cortical astrocytes. NO-induced glutamate release was prevented by calcium chelators (EGTA or BAPTA-AM) and an inhibitor of vesicular exocytosis (botulinum neurotoxin C, BoTx-C), but not by a glutamate transport inhibitor, L-trans-pyrrolidine-2,4-dicarboxylate (t-PDC), a cyclooxygenase inhibitor (indomethacin), or an inhibitor of soluble guanylate cyclase 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), and was not induced by mitochondrial respiratory inhibitors (myxothiazol or azide). Similarly to glutamate, NO-induced ATP release was also completely blocked by BAPTA-AM and BoTx-C, suggesting again a vesicular, calcium-dependent mechanism of release. Addition of DETA-NONOate (500 microM) to fura-2-loaded astrocytes induced a rapid, transient increase in intracellular calcium levels followed by a lower, sustained level of calcium entry. The latter was blocked by gadolinium (1 microM), an inhibitor of capacitative Ca(2+) entry. Thus, NO appears to cause rapid exocytosis of vesicular glutamate and ATP from astrocytes by raising intracellular calcium levels. Astrocytes activated by lipopolysaccharide/endotoxin and interferon-gamma to express inducible NO synthase (iNOS) maintained substantially higher extracellular glutamate levels than nonactivated cells or activated cells treated with an iNOS inhibitor (1400W), but the rate of glutamate uptake by these cells was similar. This suggests that NO from inflammatory-activated astrocytes causes release of astrocytic glutamate. NO-induced release of astrocytic glutamate and ATP may be important in physiological or pathological communication between astrocytes and neurons. PMID:12420311

  2. Attenuation of acute nitrogen mustard-induced lung injury, inflammation and fibrogenesis by a nitric oxide synthase inhibitor

    SciTech Connect

    Malaviya, Rama; Venosa, Alessandro; Hall, LeRoy; Gow, Andrew J.; Sinko, Patrick J.; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-12-15

    Nitrogen mustard (NM) is a toxic vesicant known to cause damage to the respiratory tract. Injury is associated with increased expression of inducible nitric oxide synthase (iNOS). In these studies we analyzed the effects of transient inhibition of iNOS using aminoguanidine (AG) on NM-induced pulmonary toxicity. Rats were treated intratracheally with 0.125 mg/kg NM or control. Bronchoalveolar lavage fluid (BAL) and lung tissue were collected 1 d–28 d later and lung injury, oxidative stress and fibrosis assessed. NM exposure resulted in progressive histopathological changes in the lung including multifocal lesions, perivascular and peribronchial edema, inflammatory cell accumulation, alveolar fibrin deposition, bronchiolization of alveolar septal walls, and fibrosis. This was correlated with trichrome staining and expression of proliferating cell nuclear antigen (PCNA). Expression of heme oxygenase (HO)-1 and manganese superoxide dismutase (Mn-SOD) was also increased in the lung following NM exposure, along with levels of protein and inflammatory cells in BAL, consistent with oxidative stress and alveolar-epithelial injury. Both classically activated proinflammatory (iNOS{sup +} and cyclooxygenase-2{sup +}) and alternatively activated profibrotic (YM-1{sup +} and galectin-3{sup +}) macrophages appeared in the lung following NM administration; this was evident within 1 d, and persisted for 28 d. AG administration (50 mg/kg, 2 ×/day, 1 d–3 d) abrogated NM-induced injury, oxidative stress and inflammation at 1 d and 3 d post exposure, with no effects at 7 d or 28 d. These findings indicate that nitric oxide generated via iNOS contributes to acute NM-induced lung toxicity, however, transient inhibition of iNOS is not sufficient to protect against pulmonary fibrosis. -- Highlights: ► Nitrogen mustard (NM) induces acute lung injury and fibrosis. ► Pulmonary toxicity is associated with increased expression of iNOS. ► Transient inhibition of iNOS attenuates acute

  3. Nitric oxide induces cotyledon senescence involving co-operation of the NES1/MAD1 and EIN2-associated ORE1 signalling pathways in Arabidopsis

    PubMed Central

    Du, Jing; Li, Manli; Kong, Dongdong; Wang, Lei; Lv, Qiang; Wang, Jinzheng; Bao, Fang; Gong, Qingqiu; Xia, Jinchan; He, Yikun

    2014-01-01

    After germination, cotyledons undertake the major role in supplying nutrients to the pre-photoautorophy angiosperm seedlings until they senesce. Like other senescence processes, cotyledon senescence is a programmed degenerative process. Nitric oxide can induce premature cotyledon senescence in Arabidopsis thaliana, yet the underlying mechanism remains elusive. A screen for genetic mutants identified the nes1 mutant, in which cotyledon senescence was accelerated by nitric oxide. Map-based cloning revealed that NES1 is allelic to a previously reported mitotic checkpoint family gene, MAD1. The nes1/mad1 mutants were restored to the wild type, in response to nitric oxide, by transforming them with pNES1::NES1. Ectopic expression of NES1 in the wild type delayed nitric oxide-mediated cotyledon senescence, confirming the repressive role of NES1. Moreover, two positive regulators of leaf senescence, the ethylene signalling component EIN2 and the transcription factor ORE1/AtNAC2/ANAC092, were found to function during nitric oxide-induced senescence in cotyledons. The block of ORE1 function delayed senescence and ectopic expression induced the process, revealing the positive role of ORE1. EIN2 was required to induce ORE1. Furthermore, the genetic interaction analysis between NES1 and ORE1 showed that the ore1 loss-of-function mutants were epistatic to nes1, suggesting the dominant role of ORE1 and the antagonistic role of NES1 during nitric oxide-induced cotyledon senescence in Arabidopsis. PMID:24336389

  4. Beneficial effects of concomitant neuronal and inducible nitric oxide synthase inhibition in ovine burn and inhalation injury.

    PubMed

    Lange, Matthias; Hamahata, Atsumori; Enkhbaatar, Perenlei; Cox, Robert A; Nakano, Yoshimitsu; Westphal, Martin; Traber, Lillian D; Herndon, David N; Traber, Daniel L

    2011-06-01

    Different isoforms of nitric oxide (NO) synthase are critically involved in the development of pulmonary failure secondary to acute lung injury. Here we tested the hypothesis that simultaneous blockade of inducible and neuronal NO synthase effectively prevents the pulmonary lesions in an ovine model of acute respiratory distress syndrome induced by combined burn and smoke inhalation injury. Chronically instrumented sheep were allocated to a sham-injured group (n = 6), an injured and untreated group (n = 6), or an injured group treated with simultaneous infusion of selective inducible and neuronal NO synthase inhibitors (n = 5). The injury was induced by 48 breaths of cotton smoke and a third-degree burn of 40% total body surface area. All sheep were mechanically ventilated and fluid resuscitated. The injury induced severe pulmonary dysfunction as indicated by decreases in PaO2/FiO2 ratio and increases in pulmonary shunt fraction, ventilatory pressures, lung lymph flow, and lung wet/dry weight ratio. The treatment fully prevented the elevations in lymph and plasma nitrate/nitrite levels, pulmonary shunting, ventilatory pressures, lung lymph flow, and wet/dry weight ratio and significantly attenuated the decline in PaO2/FiO2 ratio. In conclusion, simultaneous blockade of inducible and neuronal NO synthase exerts beneficial pulmonary effects in an ovine model of acute respiratory distress syndrome secondary to combined burn and smoke inhalation injury. This novel treatment strategy may represent a useful therapeutic adjunct for patients with these injuries. PMID:21263377

  5. PKC-Dependent Signaling Pathways within PAG and Thalamus Contribute to the Nitric Oxide-Induced Nociceptive Behavior

    PubMed Central

    Ghelardini, Carla

    2013-01-01

    Nitric oxide (NO) is an important molecule involved in nociceptive processing in the central nervous system. The release of NO within the spinal cord has long been implicated in the mechanisms underlying exaggerated pain sensitivity, and administration of NO donors can induce hyperalgesia. To elucidate the supraspinal mechanism responsible for NO-induced nociceptive hypersensitivity, we investigated the modulation of protein kinase C (PKC) and downstream effectors following treatment with the NO donors nitroglycerin and sodium nitroprusside. Both compounds induced a prolonged cold allodynia and heat hyperalgesia, increased levels of c-Fos and IL-1β, and activated NF-κB within periaqueductal grey matter and thalamus. Simultaneously, an increased expression and phosphorylation of PKC γ and ε were detected. To clarify the cellular mechanism involved in the NO-induced hypernociception, we examined the expression of transcription factors that act as PKC downstream effectors. A dramatic hyperphosphorylation of CREB and STAT1 was observed. The i.c.v. administration of the PKC blocker calphostin C prevented the NO-induced hypernociception, the hyperphosphorylation of CREB and STAT1, and partially reduced NF-κB activation. Conversely, the increase of IL-1β was unmodified by calphostin C. These results suggest the relevance of cerebral PKC-mediated CREB and STAT1 activation in the NO donor-induced nociceptive behavior. PMID:27335876

  6. Strigolactones are required for nitric oxide to induce root elongation in response to nitrogen and phosphate deficiencies in rice.

    PubMed

    Sun, Huwei; Bi, Yang; Tao, Jinyuan; Huang, Shuangjie; Hou, Mengmeng; Xue, Ren; Liang, Zhihao; Gu, Pengyuan; Yoneyama, Koichi; Xie, Xiaonan; Shen, Qirong; Xu, Guohua; Zhang, Yali

    2016-07-01

    The response of the root system architecture to nutrient deficiencies is critical for sustainable agriculture. Nitric oxide (NO) is considered a key regulator of root growth, although the mechanisms remain unknown. Phenotypic, cellular and genetic analyses were undertaken in rice to explore the role of NO in regulating root growth and strigolactone (SL) signalling under nitrogen-deficient and phosphate-deficient conditions (LN and LP). LN-induced and LP-induced seminal root elongation paralleled NO production in root tips. NO played an important role in a shared pathway of LN-induced and LP-induced root elongation via increased meristem activity. Interestingly, no responses of root elongation were observed in SL d mutants compared with wild-type plants, although similar NO accumulation was induced by sodium nitroprusside (SNP) application. Application of abamine (the SL inhibitor) reduced seminal root length and pCYCB1;1::GUS expression induced by SNP application in wild type; furthermore, comparison with wild type showed lower SL-signalling genes in nia2 mutants under control and LN treatments and similar under SNP application. Western blot analysis revealed that NO, similar to SL, triggered proteasome-mediated degradation of D53 protein levels. Therefore, we presented a novel signalling pathway in which NO-activated seminal root elongation under LN and LP conditions, with the involvement of SLs. PMID:27194103

  7. Contribution of polyamines metabolism and GABA shunt to chilling tolerance induced by nitric oxide in cold-stored banana fruit.

    PubMed

    Wang, Yansheng; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

    2016-04-15

    Effect of exogenous nitric oxide (NO) on polyamines (PAs) catabolism, γ-aminobutyric acid (GABA) shunt, proline accumulation and chilling injury of banana fruit under cold storage was investigated. Banana fruit treated with NO sustained lower chilling injury index than the control. Notably elevated nitric oxide synthetase activity and endogenous NO level were observed in NO-treated banana fruit. PAs contents in treated fruit were significantly higher than control fruit, due to the elevated activities of arginine decarboxylase and ornithine decarboxylase. NO treatment increased the activities of diamine oxidase, polyamine oxidase and glutamate decarboxylase, while reduced GABA transaminase activity to lower levels compared with control fruit, which resulted the accumulation of GABA. Besides, NO treatment upregulated proline content and significantly enhanced the ornithine aminotransferase activity. These results indicated that the chilling tolerance induced by NO treatment might be ascribed to the enhanced catabolism of PAs, GABA and proline. PMID:26616957

  8. Role of nitric oxide in the convulsive seizures induced by fluoroquinolones coadministered with 4-biphenyl acetic acid.

    PubMed

    Kohno, K; Niwa, M; Nozaki, M; Uematsu, T; Fujimura, H

    1997-11-01

    1. Contribution of nitric oxide to the convulsive seizures induced by fluoroquinolones (FQs) coadministered with 4-biphenyl acetic acid (BPAA), the active metabolite of fenbufen, was assessed in mice. 2. Enoxacin + 4-biphenyl acetic acid caused clonic seizures in all treated mice, followed by tonic seizures and death. These events were associated with a significant increase in intracerebellar cyclic GMP. 3. Pretreatment with the nitric oxide synthase (NOS) inhibitor, NG-nitro-L-arginine methylester (L-NAME), but not with D-NAME, significantly reduced the incidence of convulsions and lethality, as well as the increase in cyclic GMP. 4. Pretreatment with N-methyl-D-aspartic acid (NMDA)-receptor antagonist, MK-801, inhibited only the transition of clonic seizure to tonic seizure without affecting the incidence of clonic seizure and lethality. 5. These findings suggest that FQs + BPAA exert convulsions by activating NOS partly through the mediation of the NMDA receptor in the brain cells. PMID:9347323

  9. Lipopolysaccharide induces inducible nitric oxide synthase-dependent podocyte dysfunction via a hypoxia-inducible factor 1α and cell division control protein 42 and Ras-related C3 botulinum toxin substrate 1 pathway

    PubMed Central

    Mashmoushi, Ahmad K.; Oates, Jim C.

    2015-01-01

    Urine protein loss in immune complex-mediated diseases such as lupus nephritis is associated with podocyte foot process effacement (podocytopathy) but is not always dependent on glomerular immune complex deposition. Several murine and human studies have associated lupus nephritis with inducible nitric oxide synthase (iNOS) expression in what appear to be podocytes. This study was conducted to determine mechanisms of immune-complex-independent and iNOS-dependent podocyte dysfunction. Conditionally immortalized podocytes were cultured with lipopolysaccharide (LPS) and nitric oxide (NO), superoxide (SO), or peroxynitrite donors in the presence or absence of inhibitors of iNOS, reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase or monocyte chemotactic protein 1 (MCP-1), or with sepiapterin to increase coupling of iNOS homodimers. Podocyte NO, SO, and MCP-1 production and nitrotyrosine modifications were determined. The podocytopathy phenotype was determined by measuring cell motility and membrane permeability to albumin. This study determined that NO produced by iNOS is sufficient and necessary to induce podocytopathy. NO probably induces this phenotype via hypoxia-inducible factor 1α and cell division control protein 42 and Ras-related C3 botulinum toxin substrate 1 pathways. With LPS stimulation, neither SO nor peroxynitrite produced by uncoupled iNOS or NADPH oxidase nor MCP-1 was sufficient to induce the full phenotype. This study supports the notion that iNOS may induce autocrine podocyte dysfunction. Thus, targeting iNOS or the pathways of its induction may have therapeutic benefit. PMID:25765888

  10. Comparisons of laser-saturated, laser-induced, and planar laser-induced fluorescence measurements of nitric oxide in a lean direct-injection spray flame.

    PubMed

    Cooper, C S; Ravikrishna, R V; Laurendeau, N M

    1998-07-20

    We report quantitative, spatially resolved laser-saturated fluorescence (LSF), linear laser-induced fluorescence (LIF), and planar laser-induced fluorescence (PLIF) measurements of nitric oxide (NO) concentration in a preheated, lean direct-injection spray flame at atmospheric pressure. The spray is produced by a hollow-cone, pressure-atomized nozzle supplied with liquid heptane, and the overall equivalence ratio is unity. NO is excited by means of the Q(2)(26.5) transition of the gamma(0, 0) band. LSF and LIF detection are performed in a 2-nm region centered on the gamma(0, 1) band. PLIF detection is performed in a broad ~70-nm region with a peak transmission at 270 nm. Quantitative radial NO profiles obtained by LSF are presented and analyzed so as to correct similar LIF and PLIF profiles. Excellent agreement is achieved among the three fluorescence methodologies. PMID:18285943

  11. The use of aminoguanidine, a selective inducible nitric oxide synthase inhibitor, to evaluate the role of nitric oxide on periapical healing

    PubMed Central

    Farhad, Ali Reza; Razavi, Seyed Mohammad; Nejad, Parnian Alavi

    2011-01-01

    Background: Nitric oxide (NO) is one of the many chemical mediators involved in inflammatory processes. In addition to periapical inflammation, NO can have a role in periapical healing. The purpose of this study was to evaluate the effect of aminoguanidine (AG) as a selective inhibitor of inducible nitric oxide synthase (iNOS) on the degree of healing response of periapical lesions of the canine teeth of cats. Methods: In this interventional experimental study, the root canals of 48 cat canine teeth were infected with cat dental plaque and sealed. After induction of periapical lesions, root canal therapy (RCT) was performed. On the day of RCT phase, the cats were administered either AG (experimental group) or normal saline (control group), which was continued on a daily basis until the day of sacrifice. Four canine teeth in one cat served as negative and positive controls. The animals were sacrificed 6 weeks after RCT. The healing response of the periapical zones was analyzed histologically. The mean scores of healing for the two groups were compared using Mann–Whitney U test. Results: The mean scores of healing for the AG group (2.45±0.508) were significantly higher than those of the control group (2±0.510) (P<0.05). Conclusion: The use of an iNOS selective inhibitor such as AG can accelerate the healing process in periapical lesions. PMID:22135691

  12. Reactive nitrogen species scavenging, rather than nitric oxide inhibition, protects from articular cartilage damage in rat zymosan-induced arthritis

    PubMed Central

    Bezerra, Mirna Marques; Brain, Susan D; Greenacre, Stan; Jerônimo, Selma Maria Bezerra; de Melo, Liana Batista; Keeble, Julie; da Rocha, Francisco Airton Castro

    2003-01-01

    The contribution of nitric oxide (NO) and peroxynitrite (PN) to inflammation in a zymosan-induced (1 mg, intra-articular, i.art.) rat model of arthritis was assessed by histopathology and by measuring the glycosaminoglycan (GAG) content of the articular cartilage. Progression of the chronic synovitis in zymosan-induced arthritis (ZYA) was associated with increased nitrite and nitrotyrosine (3-NT) levels in the joint exudates that paralleled a progressive loss of the GAG content. An increase in 3-NT was also observed after i.art. PN. The nonselective nitric oxide synthase (NOS) inhibitor L-NG-nitroarginine methyl ester (25–75 mg kg−1day−1) or the selective inducible NOS inhibitor aminoguanidine (50–100 mg kg−1day−1) given 1 h before (prophylactic) or 3 days after (therapeutic) injection of the zymosan ameliorated the synovitis, but worsened the GAG loss, as measured at the end of the experiment (day 7). The PN scavenger uric acid (100–250 mg kg−1 i.p. four times daily) given prophylactically until the end of the experiment (day 14), in a dose compatible with its PN scavenging activity, significantly decreased both the synovitis and the GAG loss. In conclusion, PN formation is associated with cartilage damage in addition to proinflammatory activity in ZYA. NOS inhibitors and a PN scavenger were able to reduce the cellular infiltration, while displaying opposite effects on cartilage homeostasis either by enhancing or ameliorating the damage, respectively. PMID:14662723

  13. Nitric Oxide Functions as a Signal in Ultraviolet-B-Induced Baicalin Accumulation in Scutellaria baicalensis Suspension Cultures

    PubMed Central

    Zhang, Jin-Jie; Li, Xue-Qin; Sun, Jun-Wei; Jin, Song-Heng

    2014-01-01

    Stress induced by ultraviolet-B (UV-B) irradiation stimulates the accumulation of various secondary metabolites in plants. Nitric oxide (NO) serves as an important secondary messenger in UV-B stress-induced signal transduction pathways. NO can be synthesized in plants by either enzymatic catalysis or an inorganic nitrogen pathway. The effects of UV-B irradiation on the production of baicalin and the associated molecular pathways in plant cells are poorly understood. In this study, nitric oxide synthase (NOS) activity, NO release and the generation of baicalin were investigated in cell suspension cultures of Scutellaria baicalensis exposed to UV-B irradiation. UV-B irradiation significantly increased NOS activity, NO release and baicalin biosynthesis in S. baicalensis cells. Additionally, exogenous NO supplied by the NO donor, sodium nitroprusside (SNP), led to a similar increase in the baicalin content as the UV-B treatment. The NOS inhibitor, Nω-nitro-l-arginine (LNNA), and NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) partially inhibited UV-B-induced NO release and baicalin accumulation. These results suggest that NO is generated by NOS or NOS-like enzymes and plays an important role in baicalin biosynthesis as part of the defense response of S. baicalensis cells to UV-B irradiation. PMID:24646913

  14. Nitric oxide and heat shock protein 90 co-regulate temperature-induced bleaching in the soft coral Eunicea fusca

    NASA Astrophysics Data System (ADS)

    Ross, Cliff

    2014-06-01

    Coral bleaching represents a complex physiological process that is affected not only by environmental conditions but by the dynamic internal cellular biology of symbiotic dinoflagellates ( Symbiodinium spp.) and their cnidarian hosts. Recently, nitric oxide (NO) has emerged as a key molecule involved with the expulsion of Symbiodinium from host cnidarian cells. However, the site of production remains under debate, and the corresponding signaling pathways within and between host and endosymbiont remain elusive. In this study, using freshly isolated Symbiodinium from the soft coral Eunicea fusca, I demonstrate that thermally induced stress causes an upregulation in Symbiodinium heat shock protein 90 (Hsp90). In turn, Hsp90 shows a concomitant ability to enhance the activity of a constitutively expressed isoform of NO synthase. The resulting production of NO constitutes a signaling molecule capable of inducing Symbiodinium expulsion. Using nitric oxide synthase (NOS) and Hsp90 polyclonal antibodies, thermal stress-induced Hsp90 was shown to co-immunoprecipitate with a constitutive isoform of NOS. The specific blocking of Hsp90 activity, with the Hsp90 inhibitor geldanamycin, was capable of inhibiting NO production implicating the involvement of a coordinated regulatory system. These results have strong evolutionary implications for Hsp90-NOS chaperone complexes among biological kingdoms and provide evidence for a new functional role in symbiotic associations.

  15. Nitric oxide functions as a signal in ultraviolet-B-induced baicalin accumulation in Scutellaria baicalensis suspension cultures.

    PubMed

    Zhang, Jin-Jie; Li, Xue-Qin; Sun, Jun-Wei; Jin, Song-Heng

    2014-01-01

    Stress induced by ultraviolet-B (UV-B) irradiation stimulates the accumulation of various secondary metabolites in plants. Nitric oxide (NO) serves as an important secondary messenger in UV-B stress-induced signal transduction pathways. NO can be synthesized in plants by either enzymatic catalysis or an inorganic nitrogen pathway. The effects of UV-B irradiation on the production of baicalin and the associated molecular pathways in plant cells are poorly understood. In this study, nitric oxide synthase (NOS) activity, NO release and the generation of baicalin were investigated in cell suspension cultures of Scutellaria baicalensis exposed to UV-B irradiation. UV-B irradiation significantly increased NOS activity, NO release and baicalin biosynthesis in S. baicalensis cells. Additionally, exogenous NO supplied by the NO donor, sodium nitroprusside (SNP), led to a similar increase in the baicalin content as the UV-B treatment. The NOS inhibitor, Nω-nitro-l-arginine (LNNA), and NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) partially inhibited UV-B-induced NO release and baicalin accumulation. These results suggest that NO is generated by NOS or NOS-like enzymes and plays an important role in baicalin biosynthesis as part of the defense response of S. baicalensis cells to UV-B irradiation. PMID:24646913

  16. Beneficial Effects of Nitric Oxide Induced Mild Oxidative Stress on Post-Thawed Bull Semen Quality

    PubMed Central

    Sharafi, Mohsen; Zhandi, Mahdi; Shahverdi, Abdolhossein; Shakeri, Malak

    2015-01-01

    Background Cryopreservation of semen requires optimized conditions to minimize the harmful effects of various stresses. The main approach for protection of sperm against stress is based on the use of antioxidants and cryoprotectants, which are described as defensive methods. Recently, the application of controlled mild stressors has been de- scribed for activation of a temporary response in oocyte, embryo and somatic cells. In this study a sub-lethal oxidative stress induced by precise concentrations of nitric oxide (NO) has been evaluated for sperm during cryopreservation. Materials and Methods In this experimental study, we used different concentrations of NO [0 µM (NO-0), 0.01 µM (NO-0.01), 0.1 µM (NO-0.1), 1 µM (NO-1), 10 µM (NO-10) and 100 µM (NO-100)] during cryopreservation of bull semen. Their effects on post-thawed sperm quality that included motility and velocity parameters, plasma mem- brane functionality, acrosome integrity, apoptosis status, mitochondrial activity and lipid peroxidation after freezing-thawing were investigated. Results Exposure of sperm before freezing to NO-1 significantly increased total motility (88.4 ± 2.8%), progressive motility (50.4 ± 3.2%) and average path velocity (VAP, 53.8 ± 3.1 µm/s) compared to other extenders. In addition, NO-1 significantly increased plasma mem- brane functionality (89.3 ± 2.9%) compared to NO-0 (75.3 ± 2.9%), NO-0.01 (78.3 ± 2.9%), NO-0.1 (76.4 ± 2.9%), NO-10 (64 ± 2.9%) and NO-100 (42 ± 2.9%). Sperm exposed to NO-1 produced the highest percentage of viable (85.6 ± 2.3%) and the lowest percentage of apoptotic (10.8 ± 2.4%) spermatozoa compared to the other extenders. Also, NO-100 resulted in a higher percentage of dead spermatozoa (27.1 ± 2.7%) compared to the other extenders. In terms of mitochondrial activity, there was no significant difference among NO-0 (53.4 ± 3.2), NO-0.01 (52.1 ± 3.2), NO-0.1 (50.8 ± 3.2) and NO-1 (53.1 ± 3.2). For acrosome integrity, no significant

  17. Altered Nitric Oxide Bioavailability Contributes to Diesel Exhaust Inhalation‐Induced Cardiovascular Dysfunction in Man

    PubMed Central

    Langrish, Jeremy P.; Unosson, Jon; Bosson, Jenny; Barath, Stefan; Muala, Ala; Blackwell, Scott; Söderberg, Stefan; Pourazar, Jamshid; Megson, Ian L.; Treweeke, Andrew; Sandström, Thomas; Newby, David E.; Blomberg, Anders; Mills, Nicholas L.

    2013-01-01

    Background Diesel exhaust inhalation causes cardiovascular dysfunction including impaired vascular reactivity, increased blood pressure, and arterial stiffness. We investigated the role of nitric oxide (NO) bioavailability in mediating these effects. Methods and Results In 2 randomized double‐blind crossover studies, healthy nonsmokers were exposed to diesel exhaust or filtered air. Study 1: Bilateral forearm blood flow was measured during intrabrachial infusions of acetylcholine (ACh; 5 to 20 μg/min) and sodium nitroprusside (SNP; 2 to 8 μg/min) in the presence of the NO clamp (NO synthase inhibitor NG‐monomethyl‐l‐arginine (l‐NMMA) 8 μg/min coinfused with the NO donor SNP at 90 to 540 ng/min to restore basal blood flow). Study 2: Blood pressure, arterial stiffness, and cardiac output were measured during systemic NO synthase inhibition with intravenous l‐NMMA (3 mg/kg). Following diesel exhaust inhalation, plasma nitrite concentrations were increased (68±48 versus 41±32 nmol/L; P=0.006) despite similar l‐NMMA–induced reductions in basal blood flow (−20.6±14.7% versus −21.1±14.6%; P=0.559) compared to air. In the presence of the NO clamp, ACh and SNP caused dose‐dependent vasodilatation that was not affected by diesel exhaust inhalation (P>0.05 for both). Following exposure to diesel exhaust, l‐NMMA caused a greater increase in blood pressure (P=0.048) and central arterial stiffness (P=0.007), but reductions in cardiac output and increases in systemic vascular resistance (P>0.05 for both) were similar to those seen with filtered air. Conclusions Diesel exhaust inhalation disturbs normal vascular homeostasis with enhanced NO generation unable to compensate for excess consumption. We suggest the adverse cardiovascular effects of air pollution are, in part, mediated through reduced NO bioavailability. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT00845767 and NCT01060930. PMID:23525434

  18. Nitric oxide and nitric oxide-generating agents induce a reversible inactivation of protein kinase C activity and phorbol ester binding.

    PubMed

    Gopalakrishna, R; Chen, Z H; Gundimeda, U

    1993-12-25

    Since S-nitrosylation of protein thiols is one of the cellular regulatory mechanisms induced by nitric oxide (NO), and since protein kinase C (PKC) has critical thiol residues which influence its kinase activity, we have determined whether NO could regulate this enzyme. Initial studies were carried out with purified PKC and the NO-generating agent S-nitrosocysteine. This agent decreased phosphotransferase activity of PKC in a Ca(2+)- and oxygen-dependent manner with an IC50 of 75 microM. Phorbol ester binding was affected partially only at higher concentrations (> 100 microM) of S-nitrosocysteine. This inactivation of PKC was blocked by the NO scavenger oxyhemoglobin or reversed by dithiothreitol. It is likely that NO initially induced an S-nitrosylation of vicinal thiols, which were then oxidized to form an intramolecular disulfide. Other NO-generating agents such as S-nitroso-N-acetylpenicillamine and sodium nitroprusside, as well as authentic NO gas, induced similar types of PKC modifications. In intact B16 melanoma cells treated with S-nitrosocysteine a rapid decrease in PKC activity in both cytosol and membrane was observed. Unlike in experiments with purified PKC, in intact cells treated with S-nitrosocysteine the phorbol ester binding also decreased to a rate equal to that of PKC activity. These modifications were readily reversed by treating the homogenates with dithiothreitol in test tubes or by removing the NO-generating source from intact cells. To determine whether the limited amounts of NO generated within the intact cells could induce this type of PKC modification, the macrophage cell line IC-21 was treated with lipopolysacharide and Ca2+ ionophore A23187 to induce the NO production. With an increase in generation of NO (3-12-h period) in these cells, a parallel and irreversible decrease in PKC activity and phorbol ester binding was observed. A specific inhibitor for NO synthase, NG-monomethyl-L-arginine, inhibited both the production of NO and PKC

  19. Potential of Inducible Nitric Oxide Synthase as a Therapeutic Target for Allergen-Induced Airway Hyperresponsiveness: A Critical Connection to Nitric Oxide Levels and PARP Activity.

    PubMed

    Ibba, Salome' V; Ghonim, Mohamed A; Pyakurel, Kusma; Lammi, Matthew R; Mishra, Anil; Boulares, A Hamid

    2016-01-01

    Although expression of inducible NO synthase (iNOS) in the lungs of asthmatics and associated nitrosative damage are established, iNOS failed as a therapeutic target for blocking airway hyperresponsiveness (AHR) and inflammation in asthmatics. This dichotomy calls for better strategies with which the enzyme is adequately targeted. Here, we confirm iNOS expression in the asthmatic lung with concomitant protein nitration and poly(ADP-ribose) polymerase (PARP) activation. We show, for the first time, that iNOS is highly expressed in peripheral blood mononuclear cells (PBMCs) of asthmatics with uncontrolled disease, which did not correspond to protein nitration. Selective iNOS inhibition with L-NIL protected against AHR upon acute, but not chronic, exposure to ovalbumin or house dust mite (HDM) in mice. Supplementation of NO by nitrite administration significantly blocked AHR in chronically HDM-exposed mice that were treated with L-NIL. Protection against chronic HDM exposure-induced AHR by olaparib-mediated PARP inhibition may be associated with the partial but not the complete blockade of iNOS expression. Indeed, L-NIL administration prevented olaparib-mediated protection against AHR in chronically HDM-exposed mice. Our study suggests that the amount of iNOS and NO are critical determinants in the modulation of AHR by selective iNOS inhibitors and renews the potential of iNOS as a therapeutic target for asthma. PMID:27524861

  20. Potential of Inducible Nitric Oxide Synthase as a Therapeutic Target for Allergen-Induced Airway Hyperresponsiveness: A Critical Connection to Nitric Oxide Levels and PARP Activity

    PubMed Central

    Ghonim, Mohamed A.; Pyakurel, Kusma; Mishra, Anil

    2016-01-01

    Although expression of inducible NO synthase (iNOS) in the lungs of asthmatics and associated nitrosative damage are established, iNOS failed as a therapeutic target for blocking airway hyperresponsiveness (AHR) and inflammation in asthmatics. This dichotomy calls for better strategies with which the enzyme is adequately targeted. Here, we confirm iNOS expression in the asthmatic lung with concomitant protein nitration and poly(ADP-ribose) polymerase (PARP) activation. We show, for the first time, that iNOS is highly expressed in peripheral blood mononuclear cells (PBMCs) of asthmatics with uncontrolled disease, which did not correspond to protein nitration. Selective iNOS inhibition with L-NIL protected against AHR upon acute, but not chronic, exposure to ovalbumin or house dust mite (HDM) in mice. Supplementation of NO by nitrite administration significantly blocked AHR in chronically HDM-exposed mice that were treated with L-NIL. Protection against chronic HDM exposure-induced AHR by olaparib-mediated PARP inhibition may be associated with the partial but not the complete blockade of iNOS expression. Indeed, L-NIL administration prevented olaparib-mediated protection against AHR in chronically HDM-exposed mice. Our study suggests that the amount of iNOS and NO are critical determinants in the modulation of AHR by selective iNOS inhibitors and renews the potential of iNOS as a therapeutic target for asthma. PMID:27524861

  1. Ethanol withdrawal induces anxiety-like effects: Role of nitric oxide synthase in the dorsal raphe nucleus of rats.

    PubMed

    Gonzaga, Natália Almeida; Batistela, Melissa Resende; Padovan, Diego; de Martinis, Bruno Spinosa; Tirapelli, Carlos Renato; Padovan, Cláudia Maria

    2016-05-01

    Nitric oxide (NO) mediated transmission in the dorsal raphe nucleus (DRN) has been shown to be involved in the modulation of anxiety-like behaviors. We investigated whether inhibition of nitric oxide synthase (NOS) in the DRN would prevent anxiety-like behavior induced by ethanol withdrawal. Male Wistar rats were treated with ethanol 2-6% (v/v) for a period of 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 h after ethanol discontinuation. Rats with a guide cannula aimed at the DRN received intra-DRN injections of the non-selective NOS inhibitor NG-nitro-l-arginine methyl ester (l-NAME), selective neuronal NOS (nNOS) inhibitor N(ω)-propyl-l-arginine (NPLA), or selective inhibitor of inducible NOS (iNOS) N-([3-(aminomethyl)phenyl] methyl) ethanimidamidedihydrochloride (1400W). Five minutes later, the animals were tested in the elevated plus maze (EPM). Plasma ethanol levels were determined by gas chromatography. There was a reduction in plasma ethanol levels 48 h after ethanol withdrawal. Rats from the ethanol withdrawal group showed decreased exploration of the open arms of the EPM with no change in the exploration of enclosed arms. Intra-DRN treatment with l-NAME (100 nmoles/0.2 μL) and 1400W (1 nmol/0.2 μL), but not NPLA (10 nmoles/0.2 μL) in the DRN attenuated the decrease in the exploration of the open arms of the EPM induced by ethanol withdrawal. The major new finding of the present study is that iNOS in the DRN plays a role in the anxiety-like behavior induced by ethanol withdrawal. PMID:27139232

  2. The mechanism of the nitric oxide-mediated enhancement of tert-butylhydroperoxide-induced DNA single strand breakage

    PubMed Central

    Guidarelli, Andrea; Clementi, Emilio; Sciorati, Clara; Cantoni, Orazio

    1998-01-01

    Caffeine (Cf) enhances the DNA cleavage induced by tert-butylhydroperoxide (tB-OOH) in U937 cells via a mechanism involving Ca2+-dependent mitochondrial formation of DNA-damaging species (Guidarelli et al., 1997b). Nitric oxide (NO) is not involved in this process since U937 cells do not express the constitutive nitric oxide synthase (cNOS).Treatment with the NO donors S-nitroso-N-acetyl-penicillamine (SNAP, 10 μM), or S-nitrosoglutathione (GSNO, 300 μM), however, potentiated the DNA strand scission induced by 200 μM tB-OOH. The DNA lesions generated by tB-OOH alone, or combined with SNAP, were repaired with superimposable kinetics and were insensitive to anti-oxidants and peroxynitrite scavengers but suppressed by iron chelators.SNAP or GSNO did not cause mitochondrial Ca2+ accumulation but their enhancing effects on the tB-OOH-induced DNA strand scission were prevented by ruthenium red, an inhibitor of the calcium uniporter of mitochondria. Furthermore, the enhancing effects of both SNAP and GSNO were identical to and not additive with those promoted by the Ca2+-mobilizing agents Cf or ATP.The SNAP- or GSNO-mediated enhancement of the tB-OOH-induced DNA cleavage was abolished by the respiratory chain inhibitors rotenone and myxothiazol and was not apparent in respiration-deficient cells.It is concluded that, in cells which do not express the enzyme cNOS, exogenous NO enhances the accumulation of DNA single strand breaks induced by tB-OOH via a mechanism involving inhibition of complex III. PMID:9846647

  3. Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress

    PubMed Central

    Fu, Juanjuan; Chu, Xitong; Sun, Yongfang; Miao, Yanjun; Xu, Yuefei; Hu, Tianming

    2015-01-01

    Nitric oxide (NO) and 5-aminolevulinic acid (ALA) are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD) was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM) H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS) activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans. PMID:26151364

  4. Diclofenac enhances proinflammatory cytokine-induced nitric oxide production through NF-{kappa}B signaling in cultured astrocytes

    SciTech Connect

    Kakita, Hiroki; Aoyama, Mineyoshi Hussein, Mohamed Hamed; Kato, Shin; Suzuki, Satoshi; Ito, Tetsuya; Togari, Hajime; Asai, Kiyofumi

    2009-07-01

    Recently, the number of reports of encephalitis/encephalopathy associated with influenza virus has increased. In addition, the use of a non-steroidal anti-inflammatory drug, diclofenac sodium (DCF), is associated with a significant increase in the mortality rate of influenza-associated encephalopathy. Activated astrocytes are a source of nitric oxide (NO), which is largely produced by inducible NO synthase (iNOS) in response to proinflammatory cytokines. Therefore, we investigated whether DCF enhances nitric oxide production in astrocytes stimulated with proinflammatory cytokines. We stimulated cultured rat astrocytes with three cytokines, interleukin-1{beta}, tumor necrosis factor-{alpha} and interferon-{gamma}, and then treated the astrocytes with DCF or acetaminophen (N-acetyl-p-aminophenol: APAP). iNOS and NO production in astrocyte cultures were induced by proinflammatory cytokines. The addition of DCF augmented NO production, but the addition of APAP did not. NF-{kappa}B inhibitors SN50 and MG132 inhibited iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. Similarly, NF-{kappa}B p65 Stealth small interfering RNA suppressed iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. LDH activity and DAPI staining showed that DCF induces cell damage in cytokine-stimulated astrocytes. An iNOS inhibitor, L-NMMA, inhibited the cytokine- and DCF-induced cell damage. In conclusion, this study demonstrates that iNOS and NO are induced in astrocyte cultures by proinflammatory cytokines. Addition of DCF further augments NO production. This effect is mediated via NF-{kappa}B signaling and leads to cell damage. The enhancement of DCF on NO production may explain the significant increase in the mortality rate of influenza-associated encephalopathy in patients treated with DCF.

  5. Nitric oxide synthase inhibitors can antagonize neurogenic and calcitonin gene-related peptide induced dilation of dural meningeal vessels

    PubMed Central

    Akerman, S; Williamson, D J; Kaube, H; Goadsby, P J

    2002-01-01

    The detailed pathophysiology of migraine is beginning to be understood and is likely to involve activation of trigeminovascular afferents. Clinically effective anti-migraine compounds are believed to have actions that include peripheral inhibition of calcitonin gene-related peptide (CGRP) release from trigeminal neurones, or preventing dural vessel dilation, or both. CGRP antagonists can block both neurogenic and CGRP-induced dural vessel dilation. Nitric oxide (NO) can induce headache in migraine patients and often triggers a delayed migraine. The initial headache is thought to be caused via a direct action of the NO–cGMP pathway that causes vasodilation by vascular smooth muscle relaxation, while the delayed headache is likely to be a result of triggering trigeminovascular activation. Nitric oxide synthase (NOS) inhibitors are effective in the treatment of acute migraine. The present studies used intravital microscopy to examine the effects of specific NOS inhibitors on neurogenic dural vasodilation (NDV) and CGRP-induced dilation. The non-specific and neuronal NOS (nNOS) inhibitors were able to partially inhibit NDV, while the non-specific and endothelial NOS (eNOS) inhibitors were able to partially inhibit the CGRP induced dilation. There was no effect of the inducible NOS (iNOS) inhibitor. The data suggest that the delayed headache response triggered by NO donors in humans may be due, in part, to increased nNOS activity in the trigeminal system that causes CGRP release and dural vessel dilation. Further, eNOS activity in the endothelium causes NO production and smooth muscle relaxation by direct activation of the NO–cGMP pathway, and may be involved in the initial headache response. PMID:12183331

  6. Nitric oxide, and not vasoactive intestinal peptide, as the main neurotransmitter of vagally induced relaxation of the guinea pig stomach.

    PubMed Central

    Desai, K M; Warner, T D; Bishop, A E; Polak, J M; Vane, J R

    1994-01-01

    1. Nitric oxide synthase (NOS) was localized in the guinea pig stomach by immunocytochemistry. In vitro experiments were carried out on the isolated stomach of the guinea pig to study any possible links between nitric oxide (NO) and vasoactive intestinal peptide (VIP) in mediating relaxations induced by vagal stimulation. 2. NOS was localized to nerve cell bodies and nerve fibre varicosities of the myenteric plexus in wholemounts of the longitudinal muscle-myenteric plexus of the stomach fundus. The NOS-positive cells had a Dogiel type I morphology characteristic of motor neurones. 3. The cross-sections of the stomach wall showed NOS-positive neurones mainly in the myenteric plexus ganglia and NOS-positive nerve fibre varicosities in the circular muscle layer. 4. Relaxations induced by vagal stimulation were almost completely prevented by L-NAME with an IC50 value of 5.5 x 10(-6) M. This inhibition was reversed by L-arginine (2 mM). 5. VIP (100 nM) induced reproducible relaxations of the stomach. These were unaffected by tetrodotoxin (2 microM) or N omega-nitro-L-arginine methyl ester (L-NAME, 100 microM). 6. Desensitization to the relaxant effect of VIP partially reduced relaxations induced by vagal stimulation, glyceryl trinitrate or sodium nitroprusside but not noradrenaline. 7. These results show that NO has a neuronal origin in the guinea pig stomach, and support NO, and not VIP, as the major neurotransmitter of vagally induced gastric relaxation in the guinea pig. Images Figure 1 Figure 2 PMID:7534182

  7. L-arginine/nitric oxide pathway modulates gastric motility and gallbladder emptying induced by erythromycin and liquid meal in humans.

    PubMed

    Fiorucci, S; Distrutti, E; Quintieri, A; Sarpi, L; Spirchez, Z; Gulla, N; Morelli, A

    1995-06-01

    There is recent evidence that nitric oxide, a soluble gas produced from L-arginine, is released by the smooth muscle cells and neurons of the gastrointestinal tract where it exerts a myorelaxive action. However, little is known about the effects nitric oxide has on gastric and gallbladder motility during the inter- and postprandial phases in man. We therefore investigated the effects 200 mg/kg/hr L-arginine exerts on the gastric and gallbladder motility induced by 2 mg/kg erythromycin or a liquid meal in 21 subjects in a double-blind, placebo-controlled study. Gastric and gallbladder emptying were evaluated by sonography. Fasting antral motility was expressed as antral motility index (MI). In fasting subjects, L-arginine administration determined a threefold increase in plasma nitrite concentrations. Administration of erythromycin caused a significant rise in the antral MI, which was inhibited by L-arginine (P < 0.05). Ingestion of a liquid meal also significantly increased antral MI, but it returned to basal values 90 min after the end of the meal. Although L-arginine administration caused a significant reduction in the antral MI (P < 0.05), it did not inhibit gastric emptying. L-Arginine provoked an approximately 40% increase in basal gallbladder volume, completely blocked erythromycin-induced emptying, and partially, but significantly, prevented the emptying induced by a liquid meal (P < 0.01). Our study suggests that nitric oxide may be implicated in the physiological modulation of gastric and gallbladder motility during the inter- and postprandial phases in man. PMID:7781462

  8. Cyclo(dehydrohistidyl-l-tryptophyl) inhibits nitric oxide production by preventing the dimerization of inducible nitric oxide synthase.

    PubMed

    Sohn, Mi-Jin; Hur, Gang-Min; Byun, Hee-Sun; Kim, Won-Gon

    2008-02-15

    Dimerization of inducible NOS has been known to be a potential therapeutic target for iNOS-mediated pathologies. Cyclic dipeptides are among the simplest peptides commonly found as by-products of food processing or metabolites of microorganisms. In this study, we found that cyclo(dehydrohistidyl-l-tryptophyl) (CDHT), a cyclic dipeptide from an unidentified fungal strain Fb956, prevents iNOS dimerization in activated microglial BV-2 cells. CDHT inhibited NO production with an IC50 of 6.5 microM in LPS-treated BV-2 cells. Western blot analysis and iNOS activity measurement of fractions from size-exclusion chromatography of cell lysates indicated that CDHT inhibits dimerization of iNOS, while it has no effect on iNOS expression or enzyme activity. The CDHT inhibition of iNOS dimerization was confirmed by partially denaturing SDS-PAGE analysis. In contrast, CDHT did not affect cGMP production in endothelial HUVEC cells, which indicates no inhibition of endothelial NOS activity. These results reveal that CDHT, one of the simplest and cyclic dipeptides, selectively inhibits NO production by inhibiting iNOS dimerization, and could be a useful therapeutic agent for inflammation-mediated diseases. PMID:18061143

  9. Inducible nitric oxide synthase (NOS2) expressed in septic patients is nitrated on selected tyrosine residues: implications for enzymic activity.

    PubMed Central

    Lanone, Sophie; Manivet, Philippe; Callebert, Jacques; Launay, Jean-Marie; Payen, Didier; Aubier, Michel; Boczkowski, Jorge; Mebazaa, Alexandre

    2002-01-01

    Tyrosine nitration is a post-translational protein modification with potentially significant biological implications. In the present study we demonstrate, for the first time, that tyrosine residues of human inducible nitric oxide synthase (NOS2) can be nitrated by peroxynitrite in vitro, leading to a decreased activity. Moreover, we show that NOS2 expressed in a skeletal muscle from septic patients is nitrated on selective tyrosine residues belonging to a canonic sequence. This phenomenon could be an endogenous mechanism of in vivo modulation of NOS2 enzymic activity. PMID:12097137

  10. Effects of an endogenous nitric oxide synthase inhibitor on phorbol myristate acetate-induced acute lung injury in rats.

    PubMed

    Lin, Hen I; Chu, Shi Jye; Wang, David; Chen, Hsing I; Hsu, Kang

    2003-01-01

    1. In the present study, we determined whether the endogenous nitric oxide (NO) synthase (NOS) inhibitor Nomega-nitro-l-arginine methyl ester (l-NAME) could ameliorate the acute lung injury (ALI) induced by phorbol myristate acetate (PMA) in rat isolated lung. 2. Typical ALI was induced successfully by PMA during 60 min of observation. At 2 micro g/kg, PMA elicited a significant increase in microvascular permeability (measured using the capillary filtration coefficient Kfc), lung weight gain, lung weight/bodyweight ratio, pulmonary arterial pressure (PAP) and protein concentration of bronchoalveolar lavage fluid. 3. Pretreatment with the NOS inhibitor l-NAME (5 mmol/L) significantly attenuated ALI. None of the parameters reflective of lung injury showed significant increase, except for PAP (P < 0.001). The addition of l-arginine (4 mmol/L) blocked the protective effective of l-NAME. Pretreatment with l-arginine exacerbated PMA-induced lung injury. 4. These data suggest that l-NAME significantly ameliorates ALI induced by PMA in rats, indicating that endogenous NO plays a key role in the development of lung oedema in PMA-induced lung injury. PMID:12859432

  11. Allicin protects spinal cord neurons from glutamate-induced oxidative stress through regulating the heat shock protein 70/inducible nitric oxide synthase pathway.

    PubMed

    Liu, Shu-Guang; Ren, Peng-Yu; Wang, Guo-Yu; Yao, Shu-Xin; He, Xi-Jing

    2015-01-01

    Allicin, the main biologically active compound derived from garlic, exerts a broad spectrum of pharmacological activities and is considered to have therapeutic potential in many neurological disorders. Using an in vitro spinal cord injury model induced by glutamate treatment, we sought to investigate the neuroprotective effects of allicin in primary cultured spinal cord neurons. We found that allicin treatment significantly attenuated glutamate-induced lactate dehydrogenase (LDH) release, loss of cell viability and apoptotic neuronal death. This protection was associated with reduced oxidative stress, as evidenced by decreased reactive oxygen species (ROS) generation, reduced lipid peroxidation and preservation of antioxidant enzyme activities. The results of western blot analysis showed that allicin decreased the expression of inducible nitric oxide synthase (iNOS), but had no effects on the expression of neuronal NOS (nNOS) following glutamate exposure. Moreover, allicin treatment significantly increased the expression of heat shock protein 70 (HSP70) at both mRNA and protein levels. Knockdown of HSP70 by specific targeted small interfere RNA (siRNA) not only mitigated allicin-induced protective activity, but also partially nullified its effects on the regulation of iNOS. Collectively, these data demonstrate that allicin treatment may be an effective therapeutic strategy for spinal cord injury, and that the potential underlying mechanism involves HSP70/iNOS pathway-mediated inhibition of oxidative stress. PMID:25473931

  12. Pathological Lesions and Inducible Nitric Oxide Synthase Expressions in the Liver of Mice Experimentally Infected with Clonorchis sinensis

    PubMed Central

    Yang, Qing-Li; Shen, Ji-Qing; Xue, Yan; Cheng, Xiao-Bing; Jiang, Zhi-Hua; Yang, Yi-Chao; Chen, Ying-Dan; Zhou, Xiao-Nong

    2015-01-01

    The nitric oxide (NO) formation and intrinsic nitrosation may be involved in the possible mechanisms of liver fluke-associated carcinogenesis. We still do not know much about the responses of inducible NO synthase (iNOS) induced by Clonorchis sinensis infection. This study was conducted to explore the pathological lesions and iNOS expressions in the liver of mice with different infection intensity levels of C. sinensis. Extensive periductal inflammatory cell infiltration, bile duct hyperplasia, and fibrosis were commonly observed during the infection. The different pathological responses in liver tissues strongly correlated with the infection intensity of C. sinensis. Massive acute spotty necrosis occurred in the liver parenchyma after a severe infection. The iNOS activity in liver tissues increased, and iNOS-expressing cells with morphological differences were observed after a moderate or severe infection. The iNOS-expressing cells in liver tissues had multiple origins. PMID:26797449

  13. Nitric oxide production is not required for dihydrosphingosine-induced cell death in tobacco BY-2 cells

    PubMed Central

    Da Silva, Daniel; Lachaud, Christophe; Cotelle, Valérie; Brière, Christian; Grat, Sabine; Mazars, Christian

    2011-01-01

    Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, is known to induce a calcium-dependent programmed cell death (PCD) in tobacco BY-2 cells. We have recently shown that DHS triggers a production of H2O2, via the activation of NADPH oxidase(s). However, this production of H2O2 is not correlated with the DHS-induced cell death but would rather be associated with basal cell defense mechanisms. In the present study, we extend our current knowledge of the DHS signaling pathway, by demonstrating that DHS also promotes a production of nitric oxide (NO) in tobacco BY-2 cells. As for H2O2, this NO production is not necessary for cell death induction. PMID:21455022

  14. The AC-Stark Effect in Nitric Oxide Induced by Rapidly Swept Continuous Wave Quantum Cascade Lasers

    SciTech Connect

    Duxbury, Geoffrey; Kelly, James F.; Blake, Thomas A.; Langford, Nigel

    2012-05-07

    A large AC Stark effect has been observed when nitric oxide, at low pressure in a long optical path (100 m) Herriot cell, is subjected to infrared radiation from a rapidly swept, continuous wave infrared quantum cascade laser. As the frequency sweep rate of the laser is increased, an emission signal induced by rapid passage, occurs after the laser frequency has passed through the resonance of a molecular absorption line. At very high sweep rates a laser field-induced splitting of the absorptive part of the signal is observed, due to the AC Stark effect. This splitting is related to the Autler-Townes mixing of the hyperfine transitions, which lie within the lambda doublet components of the transition, under the Doppler broadened envelope.

  15. MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel.

    PubMed

    Jiang, Naibo; Webster, Matthew; Lempert, Walter R; Miller, Joseph D; Meyer, Terrence R; Ivey, Christopher B; Danehy, Paul M

    2011-02-01

    Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified. PMID:21283217

  16. Inhibition of IFN-γ-Induced Nitric Oxide Dependent Antimycobacterial Activity by miR-155 and C/EBPβ

    PubMed Central

    Qin, Yongwei; Wang, Qinglan; Zhou, Youlang; Duan, Yinong; Gao, Qian

    2016-01-01

    miR-155 (microRNA-155) is an important non-coding RNA in regulating host crucial biological regulators. However, its regulatory function in mycobacterium infection remains unclear. Our study demonstrates that miR-155 expression is significantly increased in macrophages after Mycobacterium marinum (M.m) infection. Transfection with anti-miR-155 enhances nitric oxide (NO) synthesis and decreases the mycobacterium burden, and vice versa, in interferon γ (IFN-γ) activated macrophages. More importantly, miR-155 can directly bind to the 3′UTR of CCAAT/enhancer binding protein β (C/EBPβ), a positive transcriptional regulator of nitric oxide synthase (NOS2), and regulate C/EBPβ expression negatively. Knockdown of C/EBPβ inhibit the production of nitric oxide synthase and promoted mycobacterium survival. Collectively, these data suggest that M.m-induced upregulation of miR-155 downregulated the expression of C/EBPβ, thus decreasing the production of NO and promoting mycobacterium survival, which may provide an insight into the function of miRNA in subverting the host innate immune response by using mycobacterium for its own profit. Understanding how miRNAs partly regulate microbicidal mechanisms may represent an attractive way to control tuberculosis infectious. PMID:27070591

  17. Stimulation of calcium-sensing receptors induces endothelium-dependent vasorelaxations via nitric oxide production and activation of IKCa channels

    PubMed Central

    Greenberg, Harry Z.E.; Shi, Jian; Jahan, Kazi S.; Martinucci, Matthew C.; Gilbert, Steven J.; Vanessa Ho, W.-S.; Albert, Anthony P.

    2016-01-01

    Stimulation of vascular calcium-sensing receptors (CaSRs) is reported to induce both constrictions and relaxations. However, cellular mechanisms involved in these responses remain unclear. The present study investigates the effect of stimulating CaSRs on vascular contractility and focuses on the role of the endothelium, nitric oxide (NO) and K+ channels in these responses. In wire myography studies, increasing [Ca2 +]o from 1 mM to 6 mM induced concentration-dependent relaxations of methoxamine pre-contracted rabbit mesenteric arteries. [Ca2 +]o-induced relaxations were dependent on a functional endothelium, and were inhibited by the negative allosteric CaSR modulator Calhex-231. [Ca2 +]o-induced relaxations were reduced by inhibitors of endothelial NO synthase, guanylate cyclase, and protein kinase G. CaSR activation also induced NO production in freshly isolated endothelial cells (ECs) in experiments using the fluorescent NO indicator DAF-FM. Pre-treatment with inhibitors of large (BKCa) and intermediate (IKCa) Ca2 +-activated K+ channels (iberiotoxin and charybdotoxin), and Kv7 channels (linopirdine) also reduced [Ca2 +]o-induced vasorelaxations. Increasing [Ca2 +]o also activated IKCa currents in perforated-patch recordings of isolated mesenteric artery ECs. These findings indicate that stimulation of CaSRs induces endothelium-dependent vasorelaxations which are mediated by two separate pathways involving production of NO and activation of IKCa channels. NO stimulates PKG leading to BKCa activation in vascular smooth muscle cells, whereas IKCa activity contributes to endothelium-derived hyperpolarisations. PMID:26772767

  18. Stimulation of calcium-sensing receptors induces endothelium-dependent vasorelaxations via nitric oxide production and activation of IKCa channels.

    PubMed

    Greenberg, Harry Z E; Shi, Jian; Jahan, Kazi S; Martinucci, Matthew C; Gilbert, Steven J; Vanessa Ho, W-S; Albert, Anthony P

    2016-05-01

    Stimulation of vascular calcium-sensing receptors (CaSRs) is reported to induce both constrictions and relaxations. However, cellular mechanisms involved in these responses remain unclear. The present study investigates the effect of stimulating CaSRs on vascular contractility and focuses on the role of the endothelium, nitric oxide (NO) and K(+) channels in these responses. In wire myography studies, increasing [Ca(2+)]o from 1mM to 6mM induced concentration-dependent relaxations of methoxamine pre-contracted rabbit mesenteric arteries. [Ca(2+)]o-induced relaxations were dependent on a functional endothelium, and were inhibited by the negative allosteric CaSR modulator Calhex-231. [Ca(2+)]o-induced relaxations were reduced by inhibitors of endothelial NO synthase, guanylate cyclase, and protein kinase G. CaSR activation also induced NO production in freshly isolated endothelial cells (ECs) in experiments using the fluorescent NO indicator DAF-FM. Pre-treatment with inhibitors of large (BKCa) and intermediate (IKCa) Ca(2+)-activated K(+) channels (iberiotoxin and charybdotoxin), and Kv7 channels (linopirdine) also reduced [Ca(2+)]o-induced vasorelaxations. Increasing [Ca(2+)]o also activated IKCa currents in perforated-patch recordings of isolated mesenteric artery ECs. These findings indicate that stimulation of CaSRs induces endothelium-dependent vasorelaxations which are mediated by two separate pathways involving production of NO and activation of IKCa channels. NO stimulates PKG leading to BKCa activation in vascular smooth muscle cells, whereas IKCa activity contributes to endothelium-derived hyperpolarisations. PMID:26772767

  19. Hypoxia-induced nitric oxide production and tumour perfusion is inhibited by pegylated arginine deiminase (ADI-PEG20)

    PubMed Central

    Burrows, Natalie; Cane, Gaelle; Robson, Mathew; Gaude, Edoardo; J. Howat, William; Szlosarek, Peter W.; Pedley, R. Barbara; Frezza, Christian; Ashcroft, Margaret; Maxwell, Patrick H.

    2016-01-01

    The hypoxic tumour microenvironment represents an aggressive, therapy-resistant compartment. As arginine is required for specific hypoxia-induced processes, we hypothesised that arginine-deprivation therapy may be useful in targeting hypoxic cancer cells. We explored the effects of the arginine-degrading agent ADI-PEG20 on hypoxia-inducible factor (HIF) activation, the hypoxia-induced nitric oxide (NO) pathway and proliferation using HCT116 and UMUC3 cells and xenografts. The latter lack argininosuccinate synthetase (ASS1) making them auxotrophic for arginine. In HCT116 cells, ADI-PEG20 inhibited hypoxic-activation of HIF-1α and HIF-2α, leading to decreased inducible-nitric oxide synthase (iNOS), NO-production, and VEGF. Interestingly, combining hypoxia and ADI-PEG20 synergistically inhibited ASS1. ADI-PEG20 inhibited mTORC1 and activated the unfolded protein response providing a mechanism for inhibition of HIF and ASS1. ADI-PEG20 inhibited tumour growth, impaired hypoxia-associated NO-production, and decreased vascular perfusion. Expression of HIF-1α/HIF-2α/iNOS and VEGF were reduced, despite an increased hypoxic tumour fraction. Similar effects were observed in UMUC3 xenografts. In summary, ADI-PEG20 inhibits HIF-activated processes in two tumour models with widely different arginine biology. Thus, ADI-PEG20 may be useful in the clinic to target therapy-resistant hypoxic cells in ASS1-proficient tumours and ASS1-deficient tumours. PMID:26972697

  20. Effect of 17β-oestradiol on cytokine-induced nitric oxide production in rat isolated aorta

    PubMed Central

    Kauser, Katalin; Sonnenberg, Dagmar; Diel, Patrick; Rubanyi, Gabor M

    1998-01-01

    Studies were performed on isolated aortic rings without endothelium to investigate the effect of 17β-oestradiol on cytokine-induced nitric oxide production by the inducible nitric oxide synthase (iNOS).Treatment of the isolated aortic rings with interleukin-1β (IL-1β, 20 μ ml−1) led to the expression of iNOS mRNA and protein, as well as significant nitrite accumulation in the incubation media and suppression of phenylephrine (1 nM–10 μM)-evoked contraction.Cycloheximide (1 μM), a protein synthesis inhibitor, prevented iNOS protein expression, nitrite accumulation and the suppression of contractility by IL-1β on the isolated aortic rings. 17β-oestradiol (1 nM–10 μM) and the partial oestrogen receptor agonist 4-OH-tamoxifen (1 nM–10 μM) produced concentration-dependent inhibition of IL-1β-induced nitrite accumulation and restored vasoconstrictor responsiveness to phenylephrine, similar to the iNOS inhibitor aminoguanidine (100 μM).Semiquantitative PCR demonstrated decreased iNOS mRNA in the IL-1β-induced and 17β-oestradiol-treated rings. Western blot analysis of rat aorta homogenates revealed that 17β-oestradiol treatment resulted in a reduction in IL-1ß-induced iNOS protein level.Incubation with tumour necrosis factor α (TNFα, 1 ng ml−1) resulted in significant nitrite accumulation in the incubation media and suppression of the smooth muscle contractile response to phenylephrine, similar to IL-1β. The effects of TNFα were also inhibited by co-incubation of the rings with 17β-oestradiol and 4-OH-tamoxifen (1 μM).The anti-transforming growth factor-β1 (TGF-β1) antibody, which inhibited TGF-β1-induced suppression of nitrite production from IL-1β-treated vascular rings, did not affect the inhibitory action of 17β-oestradiol, suggesting that the effect of oestrogen on iNOS inhibition was not mediated by TGF-β1.These results show that the ovarian sex steroid, 17β-oestradiol is a modulator of cytokine-induced

  1. Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids

    PubMed Central

    Bruder-Nascimento, Thiago; Silva, Samuel T.; Boer, Patrícia A.; Cordellini, Sandra

    2015-01-01

    Background: Physical exercise may modify biologic stress responses. Objective: To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method: Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load), stressed (2 h-immobilization), and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10). Results: None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary). Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed). Indomethacin determined a decrease in sensitivity (EC50) in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions: Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination. PMID:26083604

  2. Role of Polymorphisms of Inducible Nitric Oxide Synthase and Endothelial Nitric Oxide Synthase in Idiopathic Environmental Intolerances

    PubMed Central

    De Luca, Chiara; Gugliandolo, Agnese; Calabrò, Carlo; Currò, Monica; Ientile, Riccardo; Raskovic, Desanka; Korkina, Ludmila; Caccamo, Daniela

    2015-01-01

    Oxidative stress and inflammation play a pathogenetic role in idiopathic environmental intolerances (IEI), namely, multiple chemical sensitivity (MCS), fibromyalgia (FM), and chronic fatigue syndrome (CFS). Given the reported association of nitric oxide synthase (NOS) gene polymorphisms with inflammatory disorders, we aimed to investigate the distribution of NOS2A −2.5 kb (CCTTT)n as well as Ser608Leu and NOS3 −786T>C variants and their correlation with nitrite/nitrate levels, in a study cohort including 170 MCS, 108 suspected MCS (SMCS), 89 FM/CFS, and 196 healthy subjects. Patients and controls had similar distributions of NOS2A Ser608Leu and NOS3 −786T>C polymorphisms. Interestingly, the NOS3 −786TT genotype was associated with increased nitrite/nitrate levels only in IEI patients. We also found that the NOS2A −2.5 kb (CCTTT)11 allele represents a genetic determinant for FM/CFS, and the (CCTTT)16 allele discriminates MCS from SMCS patients. Instead, the (CCTTT)8 allele reduces by three-, six-, and tenfold, respectively, the risk for MCS, SMCS, and FM/CFS. Moreover, a short number of (CCTTT) repeats is associated with higher concentrations of nitrites/nitrates. Here, we first demonstrate that NOS3 −786T>C variant affects nitrite/nitrate levels in IEI patients and that screening for NOS2A −2.5 kb (CCTTT)n polymorphism may be useful for differential diagnosis of various IEI. PMID:25878398

  3. Stimulation of Inducible Nitric Oxide Synthase Expression by Beta Interferon Increases Necrotic Death of Macrophages upon Listeria monocytogenes Infection▿

    PubMed Central

    Zwaferink, Heather; Stockinger, Silvia; Reipert, Siegfried; Decker, Thomas

    2008-01-01

    Murine macrophage death upon infection with Listeria monocytogenes was previously shown to be increased by beta interferon, produced by the infected cells. We saw that interferon-upregulated caspase activation or other interferon-inducible, death-associated proteins, including TRAIL, protein kinase R, and p53, were not necessary for cell death. Macrophage death was reduced when inducible nitric oxide synthase (iNOS) was inhibited during infection, and iNOS-deficient macrophages were less susceptible to death upon infection than wild-type cells. The production of nitric oxide correlated with increased death, while no role was seen for iNOS in control of Listeria numbers during infection of resting macrophages. This indicates that the induction of iNOS by beta interferon in cells infected with L. monocytogenes contributes to cell death. Based on morphology, the maintenance of mitochondrial membrane potential, and a lack of dependence on caspase 1, we characterize the type of cell death occurring and show that infected macrophages die by interferon-upregulated necrosis. PMID:18268032

  4. Nitric oxide synthase mediates PC12 differentiation induced by the surface topography of nanostructured TiO2

    PubMed Central

    2013-01-01

    Background Substrate nanoscale topography influences cell proliferation and differentiation through mechanisms that are at present poorly understood. In particular the molecular mechanism through which cells 'sense’ and adapt to the substrate and activate specific intracellular signals, influencing cells survival and behavior, remains to be clarified. Results To characterize these processes at the molecular level we studied the differentiation of PC12 cells on nanostructured TiO2 films obtained by supersonic cluster beam deposition. Our findings indicate that, in PC12 cells grown without Nerve Growth Factor (NGF), the roughness of nanostructured TiO2 triggers neuritogenesis by activating the expression of nitric oxide synthase (NOS) and the phospho-extracellular signal-regulated kinase 1/2 (pERK1/2) signaling. Differentiation is associated with an increase in protein nitration as observed in PC12 cells grown on flat surfaces in the presence of NGF. We demonstrate that cell differentiation and protein nitration induced by topography are not specific for PC12 cells but can be regarded as generalized effects produced by the substrate on different neuronal-like cell types, as shown by growing the human neuroblastoma SH-SY5Y cell line on nanostructured TiO2. Conclusion Our data provide the evidence that the nitric oxide (NO) signal cascade is involved in the differentiation process induced by nanotopography, adding new information on the mechanism and proteins involved in the neuritogenesis triggered by the surface properties. PMID:24119372

  5. SENP1 inhibits the IH-induced apoptosis and nitric oxide production in BV2 microglial cells.

    PubMed

    Liu, Song; Wang, Zhong-hua; Xu, Bo; Chen, Kui; Sun, Jin-yuan; Ren, Lian-ping

    2015-11-27

    To reveal SUMOylation and the roles of Sentrin-specific proteases (SENP)s in microglial cells under Intermittent hypoxia (IH) condition would provide more intensive view of understanding the mechanisms of IH-induced central nervous system (CNS) damage. Hence, in the present study, we detected the expression levels of SENPs in microglial cells under IH and normoxia conditions via RT-PCR assay. We found that SENP1 was significantly down-regulated in cells exposure to IH. Subsequently, the effect of IH for the activation of microglia and the potential roles of SENP1 in the SENP1-overexpressing cell lines were investigated via Western blotting, RT-PCR and Griess assay. The present study demonstrated the apoptosis-inducing and activating role of IH on microglia. In addition, we revealed that the effect of IH on BV-2 including apoptosis, nitric oxide synthase (iNOS) expression and nitric oxide (NO) induction can be attenuated by SENP1 overexpression. The results of the present study are of both theoretical and therapeutic significance to explore the potential roles of SENP1 under IH condition and elucidated the mechanisms underlying microglial survival and activation. PMID:26499079

  6. Nitric oxide and bcl-2 mediated the apoptosis induced by nickel(II) in human T hybridoma cells

    SciTech Connect

    Guan Fuqin; Zhang Dongmei; Wang Xinchang; Chen Junhui . E-mail: jhchen@nju.edu.cn

    2007-05-15

    Although effects of nickel(II) on the immune system have long been recognized, little is known about the effects of nickel(II) on the induction of apoptosis and related signaling events in T cells. In the present study, we investigated the roles and signaling pathways of nickel(II) in the induction of apoptosis in a human T cell line jurkat. The results showed that the cytotoxic effects of Ni involved significant morphological changes and chromosomal condensation (Hoechst 33258 staining). Analyses of hypodiploid cells and FITC-Annexin V and PI double staining showed significant increase of apoptosis in jurkat cells 6, 12 and 24 h after nickel(II) treatment. Flow cytometry analysis also revealed that the loss of mitochondrial membrane potential (MMP) occurred concomitantly with the onset of NiCl{sub 2}-induced apoptosis. Induction of apoptotic cell death by nickel was mediated by reduction of bcl-2 expression. Furthermore, nickel stimulated the generation of nitric oxide (NO). These results suggest that nickel(II) chloride induces jurkat cells apoptosis via nitric oxide generation, mitochondrial depolarization and bcl-2 suppression.

  7. Nitric oxide associated with iNOS expression inhibits acetylcholinesterase activity and induces memory impairment during acute hypobaric hypoxia.

    PubMed

    Udayabanu, M; Kumaran, D; Nair, R Unnikrishnan; Srinivas, P; Bhagat, Neeta; Aneja, R; Katyal, Anju

    2008-09-16

    The mechanisms responsible for cholinergic dysfunction associated learning and memory impairment during hypoxia are not well-understood. However it is known that inflammatory mediators like inducible nitric oxide synthase (iNOS) hamper the functions of cholinergic neurons. In this present experiment we made an effort to study the iNOS expression mediated retrograde and anterograde memory impairment in Balb/c mice following acute hypobaric hypoxia (at an altitude of 23,000ft for 6h) using elevated plus maze and passive avoidance step-through tasks. Our results demonstrated that hypoxia transiently impairs the retrograde memory without affecting the anterograde memory functions, accompanied with a substantial rise in iNOS expression and nitric oxide levels in cerebral cortex on days 2 and 3 post hypoxia. Treatment with aminoguanidine (iNOS inhibitor ), resulted in down-regulation of the iNOS expression, attenuation of the surge of nitric oxide (NO) in cerebral cortex and reversal of retrograde memory impairment due to hypoxia. Moreover the reduced AChE activity and elevated lipid peroxidation in cerebral cortex were evident during post hypoxia re-oxygenation period, which was not observed in the hippocampus. Additionally, NO donor spermine NONOate could inhibit the AChE activity in brain homogenates in a concentration-dependent manner, which further substantiate that nitric oxide produced during post hypoxia re-oxygenation, primarily contributes to the observed inhibition of cortical AChE activity. Based on these experiments we hypothesize that the NO burst as a result of iNOS upregulation during hypoxia interrupts the memory consolidation by altering the cholinergic functions. PMID:18639532

  8. Correlation of plasma nitrite/nitrate levels and inducible nitric oxide gene expression among women with cervical abnormalities and cancer.

    PubMed

    Sowjanya, A Pavani; Rao, Meera; Vedantham, Haripriya; Kalpana, Basany; Poli, Usha Rani; Marks, Morgan A; Sujatha, M

    2016-01-30

    Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible nitric oxide synthase (iNOS), a soluble factor involved in chronic inflammation, may modulate cervical cancer risk among HPV infected women. The aim of the study was to measure and correlate plasma nitrite/nitrate levels with tissue specific expression of iNOS mRNA among women with different grades of cervical lesions and cervical cancer. Tissue biopsy and plasma specimens were collected from 120 women with cervical neoplasia or cancer (ASCUS, LSIL, HSIL and invasive cancer) and 35 women without cervical abnormalities. Inducible nitric oxide synthase (iNOS) mRNA from biopsy and plasma nitrite/nitrate levels of the same study subjects were measured. Single nucleotide polymorphism (SNP) analysis was performed on the promoter region and Ser608Leu (rs2297518) in exon 16 of the iNOS gene. Differences in iNOS gene expression and plasma nitrite/nitrate levels were compared across disease stage using linear and logistic regression analysis. Compared to normal controls, women diagnosed with HSIL or invasive cancer had a significantly higher concentration of plasma nitrite/nitrate and a higher median fold-change in iNOS mRNA gene expression. Genotyping of the promoter region showed three different variations: A pentanucleotide repeat (CCTTT) n, -1026T > G (rs2779249) and a novel variant -1153T > A. These variants were associated with increased levels of plasma nitrite/nitrate across all disease stages. The higher expression of iNOS mRNA and plasma nitrite/nitrate among women with pre-cancerous lesions suggests a role for nitric oxide in the natural history of cervical cancer. PMID:26435258

  9. Inducible Nitric Oxide Inhibitors Block NMDA Antagonist-Stimulated Motoric Behaviors and Medial Prefrontal Cortical Glutamate Efflux

    PubMed Central

    Bergstrom, Hadley C.; Darvesh, Altaf S.; Berger, S. P.

    2015-01-01

    Nitric oxide (NO) plays a critical role in the motoric and glutamate releasing action of N-methyl-D-aspartate (NMDA)-antagonist stimulants. Earlier studies utilized neuronal nitric oxide synthase inhibitors (nNOS) for studying the neurobehavioral effects of non-competitive NMDA-antagonist stimulants such as dizocilpine (MK-801) and phencyclidine (PCP). This study explores the role of the inducible nitric oxide synthase inhibitors (iNOS) aminoguanidine (AG) and (-)-epigallocatechin-3-gallate (EGCG) in NMDA-antagonist induced motoric behavior and prefrontal cortical glutamate efflux. Adult male rats were administered a dose range of AG, EGCG, or vehicle prior to receiving NMDA antagonists MK-801, PCP, or a conventional psychostimulant (cocaine) and tested for motoric behavior in an open arena. Glutamate in the medial prefrontal cortex (mPFC) was measured using in vivo microdialysis after a combination of AG or EGCG prior to MK-801. Acute administration of AG or EGCG dose-dependently attenuated the locomotor and ataxic properties of MK-801 and PCP. Both AG and EGCG were unable to block the motoric effects of cocaine, indicating the acute pharmacologic action of AG and EGCG is specific to NMDA antagonism and not generalizable to all stimulant class drugs. AG and EGCG normalized MK-801-stimulated mPFC glutamate efflux. These data demonstrate that AG and EGCG attenuates NMDA antagonist-stimulated motoric behavior and cortical glutamate efflux. Our results suggest that EGCG-like polyphenol nutraceuticals (contained in “green tea” and chocolate) may be clinically useful in protecting against the adverse behavioral dissociative and cortical glutamate stimulating effects of NMDA antagonists. Medications that interfere with NMDA antagonists such as MK-801 and PCP have been proposed as treatments for schizophrenia. PMID:26696891

  10. Endotoxin-induced nitric oxide production rescues airway growth and maturation in atrophic fetal rat lung explants

    SciTech Connect

    Rae, C.; Cherry, J.I.; Land, F.M.; Land, S.C. . E-mail: s.c.land@dundee.ac.uk

    2006-10-13

    Inflammation induces premature maturation of the fetal lung but the signals causing this effect remain unclear. We determined if nitric oxide (NO) synthesis, evoked by Escherichia coli lipopolysaccharide (LPS, 2 {mu}g ml{sup -1}), participated in this process. Fetal rat lung airway surface complexity rose 2.5-fold over 96 h in response to LPS and was associated with increased iNOS protein expression and activity. iNOS inhibition by N6-(1-iminoethyl)-L-lysine-2HCl (L-NIL) abolished this and induced airway atrophy similar to untreated explants. Surfactant protein-C (SP-C) expression was also induced by LPS and abolished by L-NIL. As TGF{beta} suppresses iNOS activity, we determined if feedback regulation modulated NO-dependent maturation. LPS induced TGF{beta}1 release and SMAD4 nuclear translocation 96 h after treatment. Treatment of explants with a blocking antibody against TGF{beta}1 sustained NO production and airway morphogenesis whereas recombinant TGF{beta}1 antagonized these effects. Feedback regulation of NO synthesis by TGF{beta} may, thus, modulate airway branching and maturation of the fetal lung.

  11. Effect of a nitric oxide-releasing naproxen derivative on hypertension and gastric damage induced by chronic nitric oxide inhibition in the rat.

    PubMed

    Muscará, M N; McKnight, W; Del Soldato, P; Wallace, J L

    1998-01-01

    NSAIDs can elevate blood pressure through mechanisms such as renal vasoconstriction and sodium retention. These effects are particularly evident in hypertensive individuals. Nitric oxide-releasing NSAID derivatives have been shown to have greatly reduced toxicity in the gastrointestinal tract and kidney. We therefore evaluated the effects of a 4 week treatment with either naproxen or its nitric oxide-releasing derivative (NO-naproxen) on systemic arterial blood pressure and gastric damage in rats in which hypertension was induced by L-NAME. Rats received either L-NAME dissolved in the drinking water (400 mg/L) or tap water (control). Vehicle, naproxen (10 mg/kg) or an equimolar dose of NO-naproxen (14.5 mg/kg) were administered orally each day. After 4 weeks, blood pressure was measured, blood samples were taken for measurement of thromboxane synthesis, and gastric damage was evaluated by blind, macroscopic scoring. Both naproxen and NO-naproxen inhibited systemic cyclooxygenase activity by >90%. NO-naproxen-treated rats exhibited no significant gastric damage. The gastric damage produced by L-NAME alone was potentiated by naproxen but prevented by NO-naproxen. L-NAME treatment significantly increased blood pressure. In the absence of L-NAME, the naproxen group had significantly higher blood pressure than both the control and NO-naproxen groups. In rats receiving L-NAME, the same conclusions apply, but the concomitant administration of NO-naproxen was able to significantly reduce the blood pressure compared to L-NAME alone. Based on these results, we conclude that NO-naproxen may represent a safer alternative to standard NSAIDs in the treatment of inflammatory conditions in hypertensive patients. PMID:9566780

  12. Dexamethasone inhibits inducible nitric-oxide synthase expression and nitric oxide production by destabilizing mRNA in lipopolysaccharide-treated macrophages.

    PubMed

    Korhonen, Riku; Lahti, Aleksi; Hämäläinen, Mari; Kankaanranta, Hannu; Moilanen, Eeva

    2002-09-01

    Nitric oxide (NO) production through the inducible nitric-oxide synthase (iNOS) pathway is increased in inflammatory diseases and leads to cellular injury. Anti-inflammatory steroids inhibit the expression of various inflammatory genes, including iNOS. In the present study, we investigated the mechanism how dexamethasone decreased NO production in murine J774 macrophages. Dexamethasone (0.1-10 microM) inhibited the production of NO and iNOS protein in a dose-dependent manner in cells stimulated with lipopolysaccharides (LPS). In contrast, in cells treated with a combination of LPS and interferon-gamma (IFN-gamma), dexamethasone did not reduce iNOS expression and NO formation. Dissociated glucocorticoid RU24858 inhibited iNOS expression and NO production to levels comparable with that of dexamethasone, suggesting that the reduced iNOS expression by dexamethasone is not a GRE-mediated event. In further studies, the effect of dexamethasone on iNOS mRNA levels was tested by actinomycin assay. The half-life of iNOS mRNA after LPS treatment was 5 h 40 min, and dexamethasone reduced it to 3 h. The increased degradation of iNOS mRNA was reversed by a protein synthesis inhibitor cycloheximide. iNOS mRNA was more stabile in cells treated with a combination of LPS plus IFN-gamma (half-life = 8 h 20 min), and dexamethasone had a minor effect in these conditions. In conclusion, dexamethasone decreases iNOS-dependent NO production by destabilizing iNOS mRNA in LPS-treated cells by a mechanism that requires de novo protein synthesis. Also, decreased iNOS mRNA and protein expression and NO formation by dexamethasone was not found in cells treated with a combination of LPS plus IFN-gamma, suggesting that the effect of dexamethasone is stimulus-dependent. PMID:12181447

  13. Nitric Oxide Plays a Key Role in Ovariectomy-Induced Apoptosis in Anterior Pituitary: Interplay between Nitric Oxide Pathway and Estrogen.

    PubMed

    Ronchetti, Sonia A; Machiavelli, Leticia I; Quinteros, Fernanda A; Duvilanski, Beatriz H; Cabilla, Jimena P

    2016-01-01

    Changes in the estrogenic status produce deep changes in pituitary physiology, mainly because estrogens (E2) are one of the main regulators of pituitary cell population. Also, E2 negatively regulate pituitary neuronal nitric oxide synthase (nNOS) activity and expression and may thereby modulate the production of nitric oxide (NO), an important regulator of cell death and survival. Little is known about how ovary ablation affects anterior pituitary cell remodelling and molecular mechanisms that regulate this process have not yet been elucidated. In this work we used freshly dispersed anterior pituitaries as well as cell cultures from ovariectomized female rats in order to study whether E2 deficiency induces apoptosis in the anterior pituitary cells, the role of NO in this process and effects of E2 on the NO pathway. Our results showed that cell activity gradually decreases after ovariectomy (OVX) as a consequence of cell death, which is completely prevented by a pan-caspase inhibitor. Furthermore, there is an increase of fragmented nuclei and DNA cleavage thereby presenting the first direct evidence of the existence of apoptosis in the anterior pituitary gland after OVX. NO production and soluble guanylyl cyclase (sGC) expression in anterior pituitary cells increased concomitantly to the apoptosis. Inhibition of both, NO synthase (NOS) and sGC activities prevented the drop of cell viability after OVX, showing for the first time that increased NO levels and sGC activity observed post-OVX play a key role in the induction of apoptosis. Conversely, E2 and prolactin treatments decreased nNOS expression and activity in pituitary cells from OVX rats in a time- and E2 receptor-dependent manner, thus suggesting interplay between NO and E2 pathways in anterior pituitary. PMID:27611913

  14. Role of reactive nitrogen species generated via inducible nitric oxide synthase in vesicant-induced lung injury, inflammation and altered lung functioning

    SciTech Connect

    Sunil, Vasanthi R.; Shen, Jianliang; Patel-Vayas, Kinal; Gow, Andrew J.; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-05-15

    Pulmonary toxicity induced by sulfur mustard and related vesicants is associated with oxidative stress. In the present studies we analyzed the role of reactive nitrogen species (RNS) generated via inducible nitric oxide synthase (iNOS) in lung injury and inflammation induced by vesicants using 2-chloroethyl ethyl sulfide (CEES) as a model. C57Bl/6 (WT) and iNOS −/− mice were sacrificed 3 days or 14 days following intratracheal administration of CEES (6 mg/kg) or control. CEES intoxication resulted in transient (3 days) increases in bronchoalveolar lavage (BAL) cell and protein content in WT, but not iNOS −/− mice. This correlated with expression of Ym1, a marker of oxidative stress in alveolar macrophages and epithelial cells. In contrast, in iNOS −/− mice, Ym1 was only observed 14 days post-exposure in enlarged alveolar macrophages, suggesting that they are alternatively activated. This is supported by findings that lung tumor necrosis factor and lipocalin Lcn2 expression, mediators involved in tissue repair were also upregulated at this time in iNOS −/− mice. Conversely, CEES-induced increases in the proinflammatory genes, monocyte chemotactic protein-1 and cyclooxygenase-2, were abrogated in iNOS −/− mice. In WT mice, CEES treatment also resulted in increases in total lung resistance and decreases in compliance in response to methacholine, effects blunted by loss of iNOS. These data demonstrate that RNS, generated via iNOS play a role in the pathogenic responses to CEES, augmenting oxidative stress and inflammation and suppressing tissue repair. Elucidating inflammatory mechanisms mediating vesicant-induced lung injury is key to the development of therapeutics to treat mustard poisoning. -- Highlights: ► Lung injury, inflammation and oxidative stress are induced by the model vesicant CEES ► RNS generated via iNOS are important in the CEES-induced pulmonary toxicity ► iNOS −/− mice are protected from CEES-induced lung toxicity and

  15. Physical exercise-induced expression of inducible nitric oxide synthase and heme oxygenase-1 in human leukocytes: effects of RRR-alpha-tocopherol supplementation.

    PubMed

    Niess, A M; Sommer, M; Schneider, M; Angres, C; Tschositsch, K; Golly, I C; Battenfeld, N; Northoff, H; Biesalski, H K; Dickhuth, H H; Fehrenbach, E

    2000-01-01

    This study evaluated the effects of RRR-alpha-tocopherol (500 IU/day, 8 days) on in vivo cytokine response and cytoplasmic expression of inducible nitric oxide synthase (iNOS) and the antioxidant stress protein heme oxygenase-1 (HO-1) in human leukocytes after exhaustive exercise. Thirteen men were investigated in a double-blind, placebo-controlled, cross-over study with a wash-out period of 28 days. The exercise procedure consisted of an incremental treadmill test followed by a continuous run until exhaustion at 110% of the individual anaerobic threshold (total duration 28.5 +/- 0.8 min). HO-1 and iNOS protein were assessed in mono- (M), lympho-, and granulocytes (G) using flow cytometry. Plasma interleukin-6 (IL-6) and IL-8 were measured by ELISA. IL-6 rose significantly whereas IL-8 did not exhibit significant changes after exercise. Changes of IL-6 were not affected by RRR-alpha-tocopherol. Exercise induced an increase of iNOS protein primarily in M and G. A small, but significant, increase of HO-1 protein was measured in M and G. RRR-alpha-Tocopherol did not show any significant effects on cytoplasmic expression of iNOS and HO-1 at rest and after exercise. In conclusion, exhaustive exercise induces expression of iNOS and HO-1 in human leukocytes by a mechanism that is not sensitive to RRR-alpha-tocopherol supplementation. PMID:11232592

  16. Nitric oxide-induced activation of NF-κB-mediated NMDA-induced CTP:phosphocholine cytidylyltransferase alpha expression inhibition in A549 cells.

    PubMed

    Li, Lian; Shen, Li; She, Hua; Yue, Shaojie; Feng, Dandan; Luo, Ziqiang

    2011-02-01

    Pulmonary surfactant is a lipoprotein complex on the alveolar surface. It reduces the surface tension at the air-water interface and stabilizes the alveoli during expiration. Surfactant deficiency or dysfunction is associated with occurrence and development of many pulmonary diseases. Family members of CTP:phosphocholine cytidylyltransferase are rate-limiting enzymes for surfactant phospholipid synthesis. We had reported recently that the expression of CTP:phosphocholine cytidylyltransferase alpha (CCT-α) was inhibited during N-methyl-D: -aspartic acid (NMDA)-induced lung injury. But the molecular mechanism underlining remains elusive. In this work, we reported that NMDA induced nitric oxide synthase (NOS) activation and nuclear factor-kB (NF-κB) subunit p65 nuclear translocation in A549 cells, which were responsible for decreased (CCT-α) expression. Furthermore, NOS activation and elevated NO production are upstream regulators for p65 nuclear translocation and (CCT-α) expression inhibition. Our results provided important clues for further elucidating the mechanisms underlying glutamate-induced lung injury. PMID:20661636

  17. Nitric oxide pathway activity modulation alters the protective effects of (-)Epigallocatechin-3-gallate on reserpine-induced impairment in rats.

    PubMed

    Chen, Cheng-Neng; Chang, Kuo-Chi; Lin, Rui-Feng; Wang, Mao-Hsien; Shih, Ruoh-Lan; Tseng, Hsiang-Chien; Soung, Hung-Sheng; Tsai, Cheng-Chia

    2016-05-15

    Reserpine (RES) has been reported to increase the brain's neural oxidative stress and cause cognitive dysfunction. Having powerful antioxidative properties, green tea catechins, especially (-)epigallocatechin-3-gallate (EGCG), are able to protect against many oxidative injuries. In this study, we examined the protecting properties of EGCG on RES-induced impairment of short-term memory in three-month-old male Wistar rats. RES (1mg/kg i.p.) induced memory impairment (p<0.001) as evaluated by the social recognition task. EGCG treatment (100mg/kg i.p. for 7days, starting 6days before RES injection) was able to improve the impaired memory caused by RES. RES treatment increased the nitric oxide (NO) level and lipid peroxidation (LPO) production, and decreased the antioxidation power in hippocampi. EGCG treatment was able to counteract the RES-induced NO level and LPO production, as well as enhanced the hippocampal antioxidation power in RES-treated rats. In order to examine the implication of NO pathway activity in RES treatment, either NO precursor (L-arginine; L-A) or NO synthase inhibitor (L-NAME; L-N) was co-pretreated with EGCG; NO precursor treatment eliminated the protective effect of EGCG, in contrast to that NO synthase inhibitor treatment significantly increased the EGCG effects on cognitive and biochemical protection in RES-treated rats. These results suggested that the NO pathway was implicated, at least in part, in the RES-induced impairment, as well as in the protective effect of EGCG in treating RES-induced impairment of memory. The above evidence provides a clinically relevant value for EGCG in preventing RES-induced cognitive dysfunction. PMID:26944334

  18. Cinnamaldehyde and cinnamaldehyde-containing micelles induce relaxation of isolated porcine coronary arteries: role of nitric oxide and calcium

    PubMed Central

    Raffai, Gábor; Kim, Byungkuk; Park, Sanga; Khang, Gilson; Lee, Dongwon; Vanhoutte, Paul M

    2014-01-01

    Background and purpose Cinnamaldehyde, a major component of cinnamon, induces the generation of reactive oxygen species and exerts vasodilator and anticancer effects, but its short half-life limits its clinical use. The present experiments were designed to compare the acute relaxing properties of cinnamaldehyde with those of self-assembling polymer micelles either loaded with cinnamaldehyde or consisting of a polymeric prodrug [poly(cinnamaldehyde)] that incorporates the compound in its backbone. Methods Rings of porcine coronary arteries were contracted with the thromboxane A2 receptor agonist U46619 or 40 mM KCl, and changes in isometric tension were recorded. Results Cinnamaldehyde induced concentration-dependent but endothelium-independent, nitric oxide synthase (NOS)-independent, cyclooxygenase-independent, soluble guanylyl cyclase (sGC)-independent, calcium-activated potassium-independent, and TRPA1 channel-independent relaxations. Cinnamaldehyde also inhibited the contractions induced by 40 mM KCl Ca2+ reintroduction in 40 mM KCl Ca2+-free solution or by the Ca2+ channel opener Bay K8644. Cinnamaldehyde-loaded control micelles induced complete, partly endothelium-dependent relaxations sensitive to catalase and inhibitors of NOS or sGC, but not cyclooxygenase or TRPA1, channels. Cinnamaldehyde-loaded micelles also inhibited contractions induced by 40 mM KCl Ca2+ reintroduction or Bay K8644. Poly(cinnamaldehyde) micelles induced only partial, endothelium-dependent relaxations that were reduced by inhibitors of NOS or sGC and by catalase and the antioxidant tiron, but not by indomethacin or TRPA1 channel blockers. Conclusion The present findings demonstrate that cinnamaldehyde-loaded and poly(cinnamaldehyde) micelles possess vasodilator properties, but that the mechanism underlying the relaxation that they cause differs from that of cinnamaldehyde, and thus could be used both to relieve coronary vasospasm and for therapeutic drug delivery. PMID:24904214

  19. Inhibition of neuronal and inducible nitric oxide synthase does not affect the analgesic effects of NMDA antagonists in visceral inflammatory pain.

    PubMed

    Srebro, Dragana; Vučković, Sonja; Prostran, Milica

    2016-01-01

    Previously we described the antinociceptive effect of magnesium sulfate and dizocilpine (MK-801) in the visceral and somatic rat models of pain. In the somatic model of pain, we established the influence of selective inhibitors of neuronal and inducible nitric oxide synthase on the antihyperalgesic effects of magnesium sulfate and dizocilpine. Therefore, the objective of the present study was to determine in the rat model of visceral pain whether same mechanisms are involved in the antinociceptive action of magnesium sulfate and dizocilpine. Analgesic activity was assessed using the acetic acid-induced writhing test in rats. Subcutaneous injection of either magnesium sulfate (15 mg/kg) or dizocilpine (0.01 mg/kg) decreased the number of writhes by about 60 and 70%, respectively. The role of nitric oxide on the effects of magnesium sulfate and dizocilpine was evaluated using selective inhibitor of neuronal (N-ω-Propyl-L-arginine hydrochloride (L-NPA)) and inducible (S-methylisothiourea (SMT)) nitric oxide synthase, which per se did not affect the number of writhes. We observed that the antinociceptive effect of magnesium sulfate or dizocilpine did not change in the presence of L-NPA (2 and 10 mg/kg, i.p.) and SMT (0.015 and 10 mg/kg, i.p.). We conclude that, nitric oxide produced by neuronal and inducible nitric oxide synthase does not modulate the effects of magnesium sulfate and dizocilpine in the visceral inflammatory model of pain in the rat. PMID:27373948

  20. Inducible Nitric Oxide Synthase Promoter Haplotypes and Residential Traffic-Related Air Pollution Jointly Influence Exhaled Nitric Oxide Level in Children

    PubMed Central

    Salam, Muhammad T.; Lin, Pi-Chu; Eckel, Sandrah P.; Gauderman, W. James; Gilliland, Frank D.

    2015-01-01

    Background Exhaled nitric oxide (FeNO), a biomarker of airway inflammation, predicts asthma risk in children. We previously found that the promoter haplotypes in inducible nitric oxide synthase (NOS2) and exposure to residential traffic independently influence FeNO level. Because NOS2 is inducible by environmental exposures such as traffic-related exposure, we tested the hypothesis that common NOS2 promoter haplotypes modulate the relationship between residential traffic-related exposure and FeNO level in children. Methods In a cross-sectional population-based study, subjects (N = 2,457; 7–11 year-old) were Hispanic and non-Hispanic white children who participated in the Southern California Children’s Health Study and had FeNO measurements. For residential traffic, lengths of local roads within circular buffers (50m, 100m and 200m radii around homes) around the subjects’ homes were estimated using geographic information system (GIS) methods. We interrogated the two most common NOS2 promoter haplotypes that were found to affect FeNO level. Results The relationship between local road lengths within 100m and 200m circular buffers and FeNO level varied significantly by one of the NOS2 promoter haplotypes (P-values for interaction between road length and NOS2 promoter haplotype = 0.02 and 0.03, respectively). In children who had ≤250m of local road lengths within 100m buffer around their homes, those with two copies of the haplotype had significantly lower FeNO (adjusted geometric mean = 11.74ppb; 95% confidence intervals (CI): 9.99 to 13.80) than those with no copies (adjusted geometric mean = 15.28ppb; 95% CI: 14.04 to 16.63) with statistically significant trend of lower FeNO level with increasing number of haplotype copy (P-value for trend = 0.002). In contrast, among children who had >250m of local road lengths within 100m buffer, FeNO level did not significantly differ by the haplotype copy-number (P-value for trend = 0.34). Similar interactive effects of

  1. Nitric Oxide Mediates the Stress Response Induced by Diatom Aldehydes in the Sea Urchin Paracentrotus lividus

    PubMed Central

    Romano, Giovanna; Costantini, Maria; Buttino, Isabella; Ianora, Adrianna; Palumbo, Anna

    2011-01-01

    Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms. PMID:22022485

  2. Increased Nitric Oxide Bioavailability and Decreased Sympathetic Modulation Are Involved in Vascular Adjustments Induced by Low-Intensity Resistance Training.

    PubMed

    Macedo, Fabrício N; Mesquita, Thassio R R; Melo, Vitor U; Mota, Marcelo M; Silva, Tharciano L T B; Santana, Michael N; Oliveira, Larissa R; Santos, Robervan V; Miguel Dos Santos, Rodrigo; Lauton-Santos, Sandra; Santos, Marcio R V; Barreto, Andre S; Santana-Filho, Valter J

    2016-01-01

    Resistance training is one of the most common kind of exercise used nowadays. Long-term high-intensity resistance training are associated with deleterious effects on vascular adjustments. On the other hand, is unclear whether low-intensity resistance training (LI-RT) is able to induce systemic changes in vascular tone. Thus, we aimed to evaluate the effects of chronic LI-RT on endothelial nitric oxide (NO) bioavailability of mesenteric artery and cardiovascular autonomic modulation in healthy rats. Wistar animals were divided into two groups: exercised (Ex) and sedentary (SED) rats submitted to the resistance (40% of 1RM) or fictitious training for 8 weeks, respectively. After LI-RT, hemodynamic measurements and cardiovascular autonomic modulation by spectral analysis were evaluated. Vascular reactivity, NO production and protein expression of endothelial and neuronal nitric oxide synthase isoforms (eNOS and nNOS, respectively) were evaluated in mesenteric artery. In addition, cardiac superoxide anion production and ventricle morphological changes were also assessed. In vivo measurements revealed a reduction in mean arterial pressure and heart rate after 8 weeks of LI-RT. In vitro studies showed an increased acetylcholine (ACh)-induced vasorelaxation and greater NOS dependence in Ex than SED rats. Hence, decreased phenylephrine-induced vasoconstriction was found in Ex rats. Accordingly, LI-RT increased the NO bioavailability under basal and ACh stimulation conditions, associated with upregulation of eNOS and nNOS protein expression in mesenteric artery. Regarding autonomic control, LI-RT increased spontaneous baroreflex sensitivity, which was associated to reduction in both, cardiac and vascular sympathetic modulation. No changes in cardiac superoxide anion or left ventricle morphometric parameters after LI-RT were observed. In summary, these results suggest that RT promotes beneficial vascular adjustments favoring augmented endothelial NO bioavailability and

  3. Folic Acid Promotes Recycling of Tetrahydrobiopterin and Protects Against Hypoxia-Induced Pulmonary Hypertension by Recoupling Endothelial Nitric Oxide Synthase

    PubMed Central

    Chalupsky, Karel; Kračun, Damir; Kanchev, Ivan; Bertram, Katharina

    2015-01-01

    Abstract Aims: Nitric oxide (NO) derived from endothelial NO synthase (eNOS) has been implicated in the adaptive response to hypoxia. An imbalance between 5,6,7,8-tetrahydrobiopterin (BH4) and 7,8-dihydrobiopterin (BH2) can result in eNOS uncoupling and the generation of superoxide instead of NO. Dihydrofolate reductase (DHFR) can recycle BH2 to BH4, leading to eNOS recoupling. However, the role of DHFR and eNOS recoupling in the response to hypoxia is not well understood. We hypothesized that increasing the capacity to recycle BH4 from BH2 would improve NO bioavailability as well as pulmonary vascular remodeling (PVR) and right ventricular hypertrophy (RVH) as indicators of pulmonary hypertension (PH) under hypoxic conditions. Results: In human pulmonary artery endothelial cells and murine pulmonary arteries exposed to hypoxia, eNOS was uncoupled as indicated by reduced superoxide production in the presence of the nitric oxide synthase inhibitor, L-(G)-nitro-L-arginine methyl ester (L-NAME). Concomitantly, NO levels, BH4 availability, and expression of DHFR were diminished under hypoxia. Application of folic acid (FA) restored DHFR levels, NO bioavailability, and BH4 levels under hypoxia. Importantly, FA prevented the development of hypoxia-induced PVR, right ventricular pressure increase, and RVH. Innovation: FA-induced upregulation of DHFR recouples eNOS under hypoxia by improving BH4 recycling, thus preventing hypoxia-induced PH. Conclusion: FA might serve as a novel therapeutic option combating PH. Antioxid. Redox Signal. 23, 1076–1091. PMID:26414244

  4. Preventive effect of gomisin J from Schisandra chinensis on angiotensin II-induced hypertension via an increased nitric oxide bioavailability.

    PubMed

    Ye, Byeong Hyeok; Lee, Seung Jin; Choi, Young Whan; Park, So Youn; Kim, Chi Dae

    2015-03-01

    Gomisin J (GJ) is a small molecular weight lignan found in Schisandra chinensis and has been demonstrated to have vasodilatory activity. In this study, the authors investigated the effect of GJ on blood pressure (BP) in angiotensin II (Ang II)-induced hypertensive mice. In addition, we determined the relative potencies of gomisin A (GA) and GJ with respect to vasodilatory activity and antihypertensive effects. C57/BL6 mice infused s.c. with Ang II (2 μg kg(-1) min(-1) for 2 weeks) showed an increase in BP and a decrease in plasma nitric oxide (NO) metabolites. In the thoracic aortas of Ang II-induced hypertensive mice, a decrease in vascular NO was accompanied by an increase in reactive oxygen species (ROS) production. Furthermore, these alterations in BP, plasma concentrations of NO metabolites and in the vascular productions of NO and ROS in Ang II-treated mice were reversed by the co-administration of GJ (1 and 3 μg kg(-1) min(-1)). In in vitro studies, Ang II decreased the cellular concentration of NO, which was accompanied by a reduction in phosphorylated endothelial nitric oxide synthase (eNOS) and an increase in ROS production. These eNOS phosphorylation and ROS production changes in Ang II-treated cells were also reversed by GJ pretreatment (0-3 μg ml(-1)). Interestingly, the vasodilatory and antihypertensive effects of GJ were more prominent than those of GA. Collectively, an increase in BP in mice treated with Ang II was markedly attenuated by GJ, which was attributed to the preservations of vascular NO bioavailability and eNOS function, and to the inhibition of ROS production in Ang II-induced hypertensive mice. PMID:25427681

  5. Attenuation of nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine in streptozotocin-treated rats.

    PubMed

    Nakazawa, Taisuke; Kaneko, Yoshiko; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2007-03-01

    Diabetes alters retinal hemodynamics, but little is known about the impact of diabetes on the role of endothelium-derived hyperpolarizing factor (EDHF) in the regulation of retinal circulation. Therefore, we examined how diabetes affects the nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine. Male Wistar rats were treated with streptozotocin (80 mg/kg, i.p.) and experiments were performed 6-8 weeks later. Under artificial ventilation, rats were treated with tetrodotoxin (100 microg/kg, i.v.) to eliminate any nerve activity and prevent movement of the eye. Methoxamine was used to maintain adequate systemic circulation. Fundus images were captured by a digital camera that was equipped with a special objective lens. The vasodilator responses of retinal arterioles were assessed by measuring changes in diameters of the vessels. In streptozotocin-induced diabetic rats and the age-matched controls, acetylcholine increased diameters of retinal arterioles in a dose-dependent manner. The vasodilator responses to acetylcholine in diabetic rats were smaller than those in control rats. The nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles observed under treatment with combination of N(G)-nitro-l-arginine methyl ester (30 mg/kg, i.v.) and indomethacin (5 mg/kg, i.v.) were also attenuated by diabetes. Diabetes did not alter the dilator responses of retinal arterioles to sodium nitroprusside and forskolin. These results suggest that diabetes impairs EDHF-mediated vasodilation of retinal arterioles induced by acetylcholine. The impaired EDHF-mediated vasodilation may contribute to alteration of retinal hemodynamics in diabetes. PMID:17079193

  6. Therapeutic Antibody-Induced Vascular Toxicity Due to Off-Target Activation of Nitric Oxide in Cynomolgus Monkeys.

    PubMed

    Pai, Rama; Ma, Ning; Connor, Anu V; Danilenko, Dimitry M; Tarrant, Jacqueline M; Salvail, Dany; Wong, Lisa; Hartley, Dylan P; Misner, Dinah; Stefanich, Eric; Wu, Yan; Chen, Yongmei; Wang, Hong; Dambach, Donna M

    2016-06-01

    PRO304186, a humanized monoclonal antibody targeting soluble interleukin-17 A and F, was developed for autoimmune and inflammatory disease indications. When administered to cynomolgus monkeys PRO304186 induced unexpected adverse effects characterized by clinical signs of hematemesis, hematochezia, and moribundity. Pathology findings included hemorrhage throughout the gastrointestinal tract without any evidence of vascular wall damage or inflammatory cellular infiltration. Mechanistic investigation of these effects revealed mild elevations of serum MCP-1 and IL-12/23 but without a classical proinflammatory profile in PRO304186-treated animals. In vitro studies demonstrated off-target effects on vascular endothelial cells including activation of nitric oxide synthase leading to production of nitric oxide (NO) accompanied by increased mitochondrial membrane depolarization, glutathione depletion, and increased paracellular permeability. Additionally, endothelial cell-PRO304186-conditioned medium reduced myosin light chain phosphorylation in vascular smooth muscle cells. Furthermore, an ex vivo study utilizing segments from cynomolgus aorta and femoral artery confirmed PRO304186-induced endothelium-dependent smooth muscle relaxation and vasodilation mediated via NO. Finally, a single dose of PRO304186 in cynomolgus monkeys induced a rapid and pronounced increase in NO in the portal circulation that preceded a milder elevation of NO in the systemic circulation and corresponded temporally with systemic hypotension; findings consistent with NO-mediated vasodilation leading to hypotension. These changes were associated with non-inflammatory, localized hemorrhage in the gastrointestinal tract consistent with hemodynamic vascular injury associated with intense local vasodilation. Together, these data demonstrate that PRO304186-associated toxicity in monkeys was due to an off-target effect on endothelium that involved regional NO release resulting in severe systemic

  7. Increased Nitric Oxide Bioavailability and Decreased Sympathetic Modulation Are Involved in Vascular Adjustments Induced by Low-Intensity Resistance Training

    PubMed Central

    Macedo, Fabrício N.; Mesquita, Thassio R. R.; Melo, Vitor U.; Mota, Marcelo M.; Silva, Tharciano L. T. B.; Santana, Michael N.; Oliveira, Larissa R.; Santos, Robervan V.; Miguel dos Santos, Rodrigo; Lauton-Santos, Sandra; Santos, Marcio R. V.; Barreto, Andre S.; Santana-Filho, Valter J.

    2016-01-01

    Resistance training is one of the most common kind of exercise used nowadays. Long-term high-intensity resistance training are associated with deleterious effects on vascular adjustments. On the other hand, is unclear whether low-intensity resistance training (LI-RT) is able to induce systemic changes in vascular tone. Thus, we aimed to evaluate the effects of chronic LI-RT on endothelial nitric oxide (NO) bioavailability of mesenteric artery and cardiovascular autonomic modulation in healthy rats. Wistar animals were divided into two groups: exercised (Ex) and sedentary (SED) rats submitted to the resistance (40% of 1RM) or fictitious training for 8 weeks, respectively. After LI-RT, hemodynamic measurements and cardiovascular autonomic modulation by spectral analysis were evaluated. Vascular reactivity, NO production and protein expression of endothelial and neuronal nitric oxide synthase isoforms (eNOS and nNOS, respectively) were evaluated in mesenteric artery. In addition, cardiac superoxide anion production and ventricle morphological changes were also assessed. In vivo measurements revealed a reduction in mean arterial pressure and heart rate after 8 weeks of LI-RT. In vitro studies showed an increased acetylcholine (ACh)-induced vasorelaxation and greater NOS dependence in Ex than SED rats. Hence, decreased phenylephrine-induced vasoconstriction was found in Ex rats. Accordingly, LI-RT increased the NO bioavailability under basal and ACh stimulation conditions, associated with upregulation of eNOS and nNOS protein expression in mesenteric artery. Regarding autonomic control, LI-RT increased spontaneous baroreflex sensitivity, which was associated to reduction in both, cardiac and vascular sympathetic modulation. No changes in cardiac superoxide anion or left ventricle morphometric parameters after LI-RT were observed. In summary, these results suggest that RT promotes beneficial vascular adjustments favoring augmented endothelial NO bioavailability and

  8. Nitric oxide-induced cellular stress and p53 activation in chronic inflammation

    PubMed Central

    Hofseth, Lorne J.; Saito, Shin'ichi; Hussain, S. Perwez; Espey, Michael G.; Miranda, Katrina M.; Araki, Yuzuru; Jhappan, Chamelli; Higashimoto, Yuichiro; He, Peijun; Linke, Steven P.; Quezado, Martha M.; Zurer, Irit; Rotter, Varda; Wink, David A.; Appella, Ettore; Harris, Curtis C.

    2003-01-01

    Free radical-induced cellular stress contributes to cancer during chronic inflammation. Here, we investigated mechanisms of p53 activation by the free radical, NO. NO from donor drugs induced both ataxia-telangiectasia mutated (ATM)- and ataxia-telangiectasia mutated and Rad3-related-dependent p53 posttranslational modifications, leading to an increase in p53 transcriptional targets and a G2/M cell cycle checkpoint. Such modifications were also identified in cells cocultured with NO-releasing macrophages. In noncancerous colon tissues from patients with ulcerative colitis (a cancer-prone chronic inflammatory disease), inducible NO synthase protein levels were positively correlated with p53 serine 15 phosphorylation levels. Immunostaining of HDM-2 and p21WAF1 was consistent with transcriptionally active p53. Our study highlights a pivotal role of NO in the induction of cellular stress and the activation of a p53 response pathway during chronic inflammation. PMID:12518062

  9. In vivo footprinting of the mouse inducible nitric oxide synthase gene: inducible protein occupation of numerous sites including Oct and NF-IL6.

    PubMed Central

    Goldring, C E; Reveneau, S; Algarté, M; Jeannin, J F

    1996-01-01

    A wide variety of cells usefully but sometimes destructively produce nitric oxide via inducible nitric oxide synthase (iNOS). Data obtained by gel shift analysis and reporter assays have linked murine iNOS gene induction by cytokines and bacterial products with the binding of a number of proteins to a proximal promoter, as well as to a distal enhancer of the iNOS gene. Nevertheless, these techniques do not necessarily reflect protein occupation of sites in vivo. To address this, we have used dimethyl sulphate in vivo footprinting to determine binding events in the two murine iNOS transcription control regions, using a classical lipopolysaccharide induction of RAW 264.7 macrophages. Protein-DNA interactions are absent before activation. Exposure to lipopolysaccharide induces protection at a NF-kappaB site and hypersensitivity at a shared gamma-activated site/interferon-stimulated response element within the enhancer. Protections are seen at a NF-IL6, and an Oct site within the promoter. We also observe modulations in guanine methylation at two regions which do not correspond to any known putative binding elements. Furthermore, we confirm the probable involvement of interferon regulatory factor-1 (binding to its -901 to -913 site) and the binding of NF-kappaB to its proximal site. Our data demonstrate an abundance of hitherto-unrecognised protein-DNA binding events upon simple lipopolysaccharide activation of the iNOS gene and suggests a role for protein-protein interactions in its transcriptional induction. PMID:8649986

  10. Role of oxidative stress, inflammation, nitric oxide and transforming growth factor-beta in the protective effect of diosgenin in monocrotaline-induced pulmonary hypertension in rats.

    PubMed

    Ahmed, Lamiaa A; Obaid, Al Arqam Z; Zaki, Hala F; Agha, Azza M

    2014-10-01

    Pulmonary hypertension is a progressive disease of various origins that is associated with right ventricular dysfunction. In the present study, the protective effect of diosgenin was investigated in monocrotaline-induced pulmonary hypertension in rats. Pulmonary hypertension was induced by a single subcutaneous injection of monocrotaline (60 mg/kg). Diosgenin (100 mg/kg) was given by oral administration once daily for 3 weeks. At the end of the experiment, mean arterial blood pressure, electrocardiography and echocardiography were recorded. Rats were then sacrificed and serum was separated for determination of total nitrate/nitrite level. Right ventricles and lungs were isolated for estimation of oxidative stress markers, tumor necrosis factor-alpha, total nitrate/nitrite and transforming growth factor-beta contents. Myeloperoxidase and caspase-3 activities in addition to endothelial and inducible nitric oxide synthase protein expression were also determined. Moreover, histological analysis of pulmonary arteries and cardiomyocyte cross-sectional area was performed. Diosgenin treatment provided a significant improvement toward preserving hemodynamic changes and alleviating oxidative stress, inflammatory and apoptotic markers induced by monocrotaline in rats. Furthermore, diosgenin therapy prevented monocrotaline-induced changes in nitric oxide production, endothelial and inducible nitric oxide synthase protein expression as well as histological analysis. These findings support the beneficial effect of diosgenin in pulmonary hypertension induced by monocrotaline in rats. PMID:25062790