Paradoxical roles of different nitric oxide synthase isoforms in colonic injury

2004 ◽  
Vol 286 (1) ◽  
pp. G137-G147 ◽  
Author(s):  
P. L. Beck ◽  
R. Xavier ◽  
J. Wong ◽  
I. Ezedi ◽  
H. Mashimo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Severe Disease ◽  
No Production ◽  
Colonic Injury ◽  
Targeted Gene Disruption ◽  
Oxide Synthase ◽  
Nos Isoforms ◽  
Lymphocyte Populations

Nitric oxide (NO) is a free radical that is largely produced by three isoforms of NO synthase (NOS): neuronal (nNOS), endothelial (eNOS), and inducible (iNOS). NO regulates numerous processes in the gastrointestinal tract; however, the overall role that NO plays in intestinal inflammation is unclear. NO is upregulated in both ulcerative colitis and Crohn's disease as well as in animal models of colitis. There have been conflicting reports on whether NO protects or exacerbates injury in colitis or is simply a marker of inflammation. To determine whether the site, timing, and level of NO production modulate the effect on the inflammatory responses, the dextran sodium sulfate model of colitis was assessed in murine lines rendered deficient in iNOS, nNOS, eNOS, or e/nNOS by targeted gene disruption. The loss of nNOS resulted in more severe disease and increased mortality, whereas the loss of eNOS or iNOS was protective. Furthermore, concomitant loss of eNOS reversed the susceptibility found in nNOS-/- mice. Deficiencies in specific NOS isoforms led to distinctive alterations of inflammatory responses, including changes in leukocyte recruitment and alterations in colonic lymphocyte populations. The present studies indicate that NO produced by individual NOS isoforms plays different roles in modulating an inflammatory process.

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

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

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

scholarly journals Phytosterols Suppress Phagocytosis and Inhibit Inflammatory Mediators via ERK Pathway on LPS-Triggered Inflammatory Responses in RAW264.7 Macrophages and the Correlation with Their Structure

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 582 ◽  
Author(s):  
Yuan ◽  
Zhang ◽  
Shen ◽  
Jia ◽  
Xie
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Responses ◽  
Ester Group ◽  
No Production ◽  
Raw264.7 Macrophages ◽  
Extracellular Signal ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Factor Α ◽  
Oxide Synthase

Phytosterols, found in many commonly consumed foods, exhibit a broad range of physiological activities including anti-inflammatory effects. In this study, the anti-inflammatory effects of ergosterol, β-sitosterol, stigmasterol, campesterol, and ergosterol acetate were investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Results showed that all phytosterol compounds alleviated the inflammatory reaction in LPS-induced macrophage models; cell phagocytosis, nitric oxide (NO) production, release of tumor necrosis factor-α (TNF-α), and expression and activity of pro-inflammatory mediator cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and phosphorylated extracellular signal-regulated protein kinase (p-ERK) were all inhibited. The anti-inflammatory activity of β-sitosterol was higher than stigmasterol and campesterol, which suggests that phytosterols without a double bond on C-22 and with ethyl on C-24 were more effective. However, inconsistent results were observed upon comparison of ergosterol and ergosterol acetate (hydroxy or ester group on C-3), which suggest that additional research is still needed to ascertain the contribution of structure to their anti-inflammatory effects.

scholarly journals Suppression of arthritis by an inhibitor of nitric oxide synthase.

1993 ◽  
Vol 178 (2) ◽  
pp. 749-754 ◽  
Author(s):  
N McCartney-Francis ◽  
J B Allen ◽  
D E Mizel ◽  
J E Albina ◽  
Q W Xie ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Responses ◽  
Inflammatory Cells ◽  
No Production ◽  
Streptococcal Cell Wall ◽  
Cell Mediated Immune Response ◽  
A Cell ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Articular Index

Nitric oxide (NO), a toxic radical gas produced during the metabolism of L-arginine by NO synthase (NOS), has been implicated as a mediator of immune and inflammatory responses. A single injection of streptococcal cell wall fragments (SCW) induces the accumulation of inflammatory cells within the synovial tissue and a cell-mediated immune response that leads destructive lesions. We show here that NO production is elevated in the inflamed joints of SCW-treated rats. Administration of NG-monomethyl-L-arginine, an inhibitor of NOS, profoundly reduced the synovial inflammation and tissue damage as measured by an articular index and reflected in the histopathology. These studies implicate the NO pathway in the pathogenesis of an inflammatory arthritis and demonstrate the ability of a NOS inhibitor to modulate the disease.

Myogenic NOS and endogenous NO production are defective in colon from dystrophic (mdx) mice

2001 ◽  
Vol 281 (5) ◽  
pp. G1264-G1270 ◽  
Author(s):  
Flavia Mulè ◽  
Maria Giuliana Vannucchi ◽  
Letizia Corsani ◽  
Rosa Serio ◽  
Maria Simonetta Faussone-Pellegrini
Keyword(s):  
Nitric Oxide ◽  
Intraluminal Pressure ◽  
Mdx Mice ◽  
No Production ◽  
Free Solution ◽  
Mouse Colon ◽  
Voltage Dependent ◽  
Oxide Synthase ◽  
Nos Isoforms ◽  
Inducible Nos

The aim of the present study was to evaluate whether alterations in the distribution and/or function of nitric oxide synthase (NOS) could be involved in the development of the spontaneous mechanical tone observed in colon from dystrophic ( mdx) mice. By recording the intraluminal pressure of isolated colon from normal mice, we showed that N ω-nitro- l-arginine methyl ester (l-NAME) increased the tone, even in the presence of tetrodotoxin. The effect was prevented by l-arginine, nifedipine, or Ca2+-free solution. In colon from mdx mice, l-NAME was ineffective. Immunohistochemistry revealed that the presence and distribution of neuronal (nNOS), endothelial, and inducible NOS isoforms in smooth muscle cells and neurons of colon from mdx mice were the same as in controls. However, the expression of myogenic nNOS was markedly reduced in mdx mice. We conclude that there is a myogenic NOS in mouse colon that can tonically produce nitric oxide to limit influx of Ca2+ through L-type voltage-dependent channels and modulate the mechanical tone. This mechanism appears to be defective in mdx mice.

Expression of nitric oxide synthase isoforms and detection of nitric oxide in rat placenta

2002 ◽  
Vol 282 (4) ◽  
pp. C762-C767 ◽  
Author(s):  
Tatsuya Takizawa ◽  
Hiroshi Yoshikawa ◽  
Miho Yamada ◽  
Hidetoshi Morita
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Pcr Analysis ◽  
No Production ◽  
Epr Spectrum ◽  
Pregnant Rats ◽  
Paramagnetic Resonance ◽  
Triplet Signal ◽  
Oxide Synthase ◽  
Nos Isoforms

Nitric oxide (NO) production in the rat placenta was monitored and quantified by electron paramagnetic resonance (EPR) spectroscopy with hemoglobin and an Fe- N-(dithiocarboxy)sarcosine (DTCS) complex as NO-trapping reagents. Expression of nitric oxide synthase (NOS) isoforms was also examined by quantitative RT-PCR analysis. The EPR spectrum of the placenta with hemoglobin trapping showed a three-line hyperfine structure ( g = 2.008 and a = 1.66-mT). The EPR signal was diminished after the placenta was homogenized or the NOS inhibitor l-NAME was administered to pregnant rats. Therefore, the specific signal was definitely identified as being derived from endogenous NO spin-trapped by hemoglobin, and the EPR spectrum showed that the NO adduct existed as a pentacoordinate α-NO heme species. The EPR spectrum of the placenta with Fe-DTCS trapping showed a triplet signal ( g = 2.038) derived from an NO-Fe-DTCS complex. The height of the triplet signal did not vary significantly with gestational stage during the last few days of gestation. At the gestational stages examined, the level of NOS II mRNA expression was significantly higher than that of NOS III mRNA. NOS II expression in term ( day 21.5) placenta was significantly increased compared with that in preterm ( day 19.5) placenta ( P < 0.01, n = 4 or 5). These results suggest that NOS II is the predominant producer of NO in the placenta and that NOS II-generated NO plays significant roles in the maintenance of placental functions immediately before birth.

scholarly journals CHICKEN ANAEMIA VIRUS IMPAIRS NITRIC OXIDE PRODUCTION IN HD11 CHICKEN MACROPHAGES

2020 ◽  
Vol 57 (4) ◽  
Author(s):  
Katja Ester ◽  
William Lauman Ragland
Keyword(s):  
Nitric Oxide ◽  
Severe Disease ◽  
Interferon Γ ◽  
Economic Losses ◽  
No Production ◽  
Subclinical Infection ◽  
Chicken Anaemia Virus ◽  
No Formation ◽  
Chicken Macrophage ◽  
Oxide Synthase

Immunosuppressive viruses cause substantial economic losses to the poultry industry. Chicken anaemia virus (CAV) causes severe disease in young chickens, whereas subclinical infection in older birds causes immunosuppression. In this study, we addressed the ability of CAV to interfere with production of antimicrobial molecule nitric oxide (NO) by macrophages. NO production in chicken macrophage cell line HD11 was induced using both Toll-like receptor 4 agonist, bacterial lipopolysaccharide, and an immune modulator, interferon-γ. In addition, we treated macrophages with CAV propagated in chicken lymphoblastoid cells. The levels of NO were measured by the Griess reaction. Addition of CAV decreased both the interferon-γ and the lipopolysaccharide associated induction of NO. Observed effect was not caused by CAV-related cytotoxicity, as no decrease in number of viable cells was observed. Although CAV could not completely abrogate NO production, attenuation of NO induction was clearly present. We have previously shown that CAV interferes with the expression of interferons in chickens during subclinical infection. Since the signalling pathways of expression of interferons and type 2 nitric oxide synthase, enzyme involved in NO formation, overlap, we conclude that measured decrease in NO levels is a consequence of CAV interference with interferon and NO synthase signalling. Regardless of the fact whether the attenuation of NO serves as a viral primary defence, or is only a secondary effect, it could impair the immune response to other pathogens and contribute to the global immunosuppression in chicken houses.Key words: chicken; immunosuppression; chicken anaemia virus (CAV); macrophage; nitric oxide (NO) VIRUS PIŠČANČJE ANEMIJE VPLIVA NA PROIZVODNJO DUŠIKOVIH OKSIDOV V MAKROFAGIH PIŠČANEV HD11 Povzetek: Imunosupresivni virusi povzročajo velike gospodarske izgube v perutninski industriji. Virus piščančje anemije (CAV) pri mladih piščancih povzroča hudo bolezen, medtem ko subklinična okužba pri starejših pticah povzroča oslabljen imunski odziv. V tej raziskavi je bil spremljan vpliv CAV na proizvodnjo dušikovih oksidov (NO) v makrofagih. Proizvodnja NO v piščančjih makrofagih v celični liniji HD11 je bila sprožena z uporabo agonista Toll-u podobnega receptorja 4, bakterijskega lipopolisaharida in imunskega modulatorja interferona-γ, makrofagi pa so bili okuženi s CAV, razmnoženim v piščančjih limfoblastoidnih celicah. Ravni NO so izmerili po Griessovi reakciji. Prisotnost CAV je zmanjšala proizvodnjo NO, spodbujeno tako z interferonom-γ, kot z lipopolisaharidom. Opaženega učinka ni povzročila citotoksičnost, povezana s CAV, saj ni bilo opaziti zmanjšanja števila živih celic. Čeprav CAV ni popolnoma zavrla nastajanja NO, je bilo očitno prisotno zmanjšanje nastajanja NO. Pred tem so pokazali, da CAV moti izražanje interferonov pri piščancih med subklinično okužbo. Ker se poti znotrajceličnega prenosa urejanja izražanja interferonov in sintaze dušikovih oksidov tipa 2, encima, ki sodeluje pri tvorbi NO, prekrivajo, predvidevamo, da je izmerjeno znižanje ravni NO posledica motenj CAV pri znotrajceličnem prenosu sporočila interferona do sintaze dušikovih oksidov. Ne glede na to, ali zaviranje nastajanja NO služi kot primarna virusna obramba ali je le sekundarni učinek, lahko poslabša imunski odziv na druge patogene in prispeva k splošnemu zmanjšanju imunskega odziva v kurnikih ali na kokošjih farmah.Ključne besede: piščanci; zmanjšanje imunskega odziva; virus piščančje anemije (CAV); makrofagi; dušikov oksid (NO)

NO production by cNOS and iNOS reflects blood pressure changes in LPS-challenged mice

2003 ◽  
Vol 285 (4) ◽  
pp. E871-E875 ◽  
Author(s):  
Marcella M. Hallemeesch ◽  
Ben J. A. Janssen ◽  
Wouter J. de Jonge ◽  
Peter B. Soeters ◽  
Wouter H. Lamers ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Blood Pressure Response ◽  
No Production ◽  
Baseline Conditions ◽  
Pressure Changes ◽  
Oxide Synthase ◽  
Nos Isoforms ◽  
Firm Evidence ◽  
Lps Treatment

Increased nitric oxide (NO) production is the cause of hypotension and shock during sepsis. In the present experiments, we have measured the contribution of endothelial (e) and inducible (i) nitric oxide synthase (NOS) to systemic NO production in mice under baseline conditions and upon LPS treatment (100 μg/10 g ip LPS). NO synthesis was measured by the rate of conversion of l-[ guanidino-15N2]arginine to l-[ ureido-15N]citrulline, and the contribution of the specific NOS isoforms was evaluated by comparing NO production in eNOS-deficient [(–/–)] and iNOS(–/–) mice with that in wild-type (WT) mice. Under baseline conditions, NO production was similar in WT and iNOS(–/–) mice but lower in eNOS(–/–) mice [WT: 1.2 ± 0.2; iNOS(–/–): 1.2 ± 0.2; eNOS(–/–): 0.6 ± 0.3 nmol · 10 g body wt–1· min–1]. In response to the challenge with LPS (5 h), systemic NO production increased in WT and eNOS(–/–) mice but fell in iNOS(–/–) mice [WT: 2.7 ± 0.3; eNOS(–/–): 2.2 ± 0.6; iNOS(–/–): 0.7 ± 0.1 nmol · 10 g body wt–1· min–1]. After 5 h of LPS treatment, blood pressure had dropped 14 mmHg in WT but not in iNOS(–/–) mice. The present findings provide firm evidence that, upon treatment with bacterial LPS, the increase of NO production is solely dependent on iNOS, whereas that mediated by cNOS is reduced. Furthermore, the data show that the LPS-induced blood pressure response is dependent on iNOS.

Upregulation of endothelial and neuronal constitutive nitric oxide synthase in pregnant rats

1996 ◽  
Vol 271 (6) ◽  
pp. R1739-R1745 ◽  
Author(s):  
D. L. Xu ◽  
P. Y. Martin ◽  
J. St John ◽  
P. Tsai ◽  
S. N. Summer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Western Blot ◽  
Mesenteric Arteries ◽  
No Production ◽  
Pregnant Rats ◽  
Neuronal Nos ◽  
Peripheral Arterial ◽  
Constitutive Nitric Oxide Synthase ◽  
Oxide Synthase ◽  
Nos Isoforms

Pregnancy is characterized by hemodynamic and body fluid alterations. Increased nitric oxide (NO) production has been suggested to play a role in the hemodynamic alterations of pregnancy and has also been reported to increase arginine vasopressin (AVP) release. We therefore hypothesized that gestation could increase both NO synthase (NOS) constitutive isoforms, neuronal NOS and endothelial NOS, and thereby contribute to the hyposmolality and peripheral arterial vasodilation of pregnancy, respectively. The present study was therefore undertaken to examine the constitutive NOS isoforms in aortas, mesenteric arteries, and hypothalami of pregnant rats on day 20 of gestation compared with age-matched nonpregnant rats. Plasma AVP was determined by radioimmunoassay and hypothalamic mRNA AVP by solution hybridization assay. Hypothalamic neuronal NOS was assessed by Northern blot and Western blot; endothelial NOS was assessed by Western blot in arteries and hypothalamus. The results demonstrated that 1) plasma AVP and hypothalamic AVP mRNA are increased in pregnant rats (n = 8), 2) neuronal NOS protein and mRNA are increased in hypothalamus of pregnant rats (n = 4), and 3) endothelial NOS expression, as assessed by Western blot analysis, is increased in both conductance (aorta) as well as resistance (mesenteric) arteries of pregnant rats (n = 4). We conclude that both of the constitutive NOS isoforms are increased in pregnant rats, suggesting that the peripheral arterial vasodilation and hyposmolality of pregnancy could be mediated by these isoforms.

scholarly journals Does Melatonin Exert Its Effect on Ram Sperm Capacitation Through Nitric Oxide Synthase Regulation?

2020 ◽  
Vol 21 (6) ◽  
pp. 2093
Author(s):  
Sara Miguel-Jiménez ◽  
Melissa Carvajal-Serna ◽  
Silvia Calvo ◽  
Adriana Casao ◽  
José Álvaro Cebrián-Pérez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Acrosome Reaction ◽  
No Production ◽  
Sperm Capacitation ◽  
Synthase Regulation ◽  
Oxide Synthase ◽  
Nos Isoforms ◽  
Ram Sperm

Nitric oxide (NO·), synthesized from L-arginine by nitric oxide synthase (NOS), is involved in sperm functionality. NOS isoforms have been detected in spermatozoa from different species, and an increment in NOS activity during capacitation has been reported. This work aims to determine the presence and localization of NOS isoforms in ram spermatozoa and analyse their possible changes during in vitro capacitation. Likewise, we investigated the effect of melatonin on the expression and localization of NOS and NO· levels in capacitated ram spermatozoa. Western blot analysis revealed protein bands associated with neuronal NOS (nNOS) and epithelial NOS (eNOS) but not with inducible NOS (iNOS). However, the three isoforms were detected by indirect immunofluorescence (IFI), and their immunotypes varied over in vitro capacitation with cAMP-elevating agents. NO· levels (evaluated by DAF-2-DA/PI staining) increased after in vitro capacitation, and the presence of L-arginine in the capacitating medium raised NO· production and enhanced the acrosome reaction. Incubation in capacitating conditions with a high-cAMP medium with melatonin modified the NOS distribution evaluated by IFI, but no differences in Western blotting were observed. Melatonin did not alter NO· levels in capacitating conditions, so we could infer that its role in ram sperm capacitation would not be mediated through NO· metabolism.

Upregulation of endothelial constitutive NOS: a major role in the increased NO production in cirrhotic rats

1996 ◽  
Vol 270 (3) ◽  
pp. F494-F499 ◽  
Author(s):  
P. Y. Martin ◽  
D. L. Xu ◽  
M. Niederberger ◽  
A. Weigert ◽  
P. Tsai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mesenteric Arteries ◽  
Inos Mrna ◽  
No Production ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Peripheral Arterial ◽  
Oxide Synthase ◽  
Nos Isoforms

Nitric oxide (NO) is postulated to mediate the peripheral arterial vasodilation in cirrhosis. However, it is not known which isoform of the nitric oxide synthase (NOS) is involved in the increased production of NO. This study was therefore undertaken to examine the expression of the NOS isoforms in arteries of cirrhotic rats compared with controls. Cirrhosis was induced by CCl4, and vessels were harvested for immunoblots using antibodies against inducible NOS (iNOS) and endothelial constitutive NOS (ecNOS). Endothelial cells were used as controls for ecNOS, and vascular smooth muscle cells treated with lipopolysaccharide or septic rats were used for iNOS controls. The results demonstrated an upregulation of ecNOS in both the aortas and mesenteric arteries of cirrhotic compared with control rats. Chronic inhibition of NOS decreased ecNOS in cirrhotic vessels. Although iNOS mRNA was found by reverse transcription-polymerase chain reaction in arteries of cirrhotic rats, iNOS protein was not detectable by immunoblotting compared with septic rats, suggesting a low vascular level of this isoform. In conclusion, the ecNOS seems to play a major role in the increased NO production in cirrhotic rats, whereas the role of iNOS remains elusive.

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