Effect of Triterpene Acids of Eriobotrya japonica (Thunb.) Lindl. Leaf and MAPK Signal Transduction Pathway on Inducible Nitric Oxide Synthase Expression in Alveolar Macrophage of Chronic Bronchitis Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1099-1111 ◽  
Author(s):  
Y. Huang ◽  
J. Li ◽  
X. M. Meng ◽  
G. L. Jiang ◽  
H. Li ◽  
...  

The goal of this study was to investigate the possible therapy mechanism of triterpene acids of Eriobotrya japonica (Thunb.) Lindl. Leaf (TAL) in alveolar macrophage (AM) of chronic bronchitis (CB) rats. CB model was established by injection of bacillus calmette guein (BCG) plus lipopolisacharide (LPS) in rats. TAL significantly inhibited the increased NO concentration, iNOS expression and phosphorylation of p38 MAPK in alveolar macrophages (AMs) of CB rats. Using in vivo test, we found that SB203580, a p38 MAPK inhibitor, (10 μM) significantly inhibited inducible nitric oxide synthase (iNOS) mRNA expression in AM. This data indicate that TAL highly decreases excessive iNOS expression and NO induction, and p38 MAPK signal transduction participates in iNOS expression and NO induction in AM of CB rats. The effect of TAL on iNOS expression in AM may be related to its inhibition of p38 MAPK signal transduction.

2000 ◽  
Vol 92 (4) ◽  
pp. 1093-1102 ◽  
Author(s):  
Klaus Tschaikowsky ◽  
Jörg Ritter ◽  
Klaus Schröppel ◽  
Matthias Kühn

Background Nitric oxide released by inducible nitric oxide synthase (iNOS) plays an important role in immune responses and systemic vasodilation in septic shock. Volatile anesthetics have been reported to interfere with signal transduction and gene expression. We studied the effect of volatile anesthetics on activity and expression of iNOS and potential mechanisms of action. Methods Nitrite release and iNOS expression were determined using the Griess reaction and Western and Northern blot techniques, respectively, in J774 murine macrophages stimulated with lipopolysaccharide and gamma-interferon in the absence and presence of various concentrations (0.25-2.0 minimum alveolar concentration [MAC]) of volatile anesthetics (i.e., halothane, enflurane, isoflurane, desflurane). Furthermore, potential interference of volatile anesthetics with specific signal transduction pathways was investigated. Results All volatile anesthetics, studied in a time- and dose-dependent manner, suppressed nitrite production and iNOS expression in J774 macrophages stimulated by lipopolysaccharide or gamma-interferon at clinically relevant concentrations. The inhibition was completely antagonized by ionomycin but unaffected by diacylglycerol, phorbol myristate acetate, and C2-ceramide. In contrast, in cells costimulated by lipopolysaccharide plus gamma-interferon, volatile anesthetics significantly increased nitrite production and iNOS expression independent of ionomycin and other mediators studied. Conclusions Volatile anesthetics strongly reduced the mRNA and protein levels of iNOS and NOS activity after a single stimulation with lipopolysaccharide or gamma-interferon, most likely by attenuating intracellular calcium increase. Costimnulation with lipopolysaccharide plus gamma-interferon, however, results in maximum iNOS expression and activity, which are no longer inhibited but are potentiated by volatile anesthetics by unidentified mechanisms.


2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Tuija Turpeinen ◽  
Riina Nieminen ◽  
Ville Taimi ◽  
Taina Heittola ◽  
Outi Sareila ◽  
...  

The role of dual specificity phosphatase 1 (DUSP1) in inducible nitric oxide synthase (iNOS) expression in A549 human pulmonary epithelial cells, J774 mouse macrophages and primary mouse bone marrow-derived macrophages (BMMs) was investigated. iNOS expression was induced by a cytokine mixture (TNF, IFNγ and IL-1β) in A549 cells and by LPS in J774 cells, and it was inhibited by p38 MAPK inhibitors SB202190 and BIRB 796. Stimulation with cytokine mixture or LPS enhanced also DUSP1 expression. Down-regulation of DUSP1 by siRNA increased p38 MAPK phosphorylation and iNOS expression in A549 and J774 cells. In addition, LPS-induced iNOS expression was enhanced in BMMs from DUSP1(−/−)mice as compared to that in BMMs from wild-type mice. The results indicate that DUSP1 suppresses iNOS expression by limiting p38 MAPK activity in human and mouse cells. Compounds that enhance DUSP1 expression or modulate its function may be beneficial in diseases complicated with increased iNOS-mediated NO production.


2000 ◽  
Vol 68 (12) ◽  
pp. 7087-7093 ◽  
Author(s):  
Y.-H. Li ◽  
Z.-Q. Yan ◽  
J. Skov Jensen ◽  
K. Tullus ◽  
A. Brauner

ABSTRACT Chronic lung disease (CLD) of prematurity is an inflammatory disease with a multifactorial etiology. The importance ofUreaplasma urealyticum in the development of CLD is debated, and steroids produce some improvement in neonates with this disease. In the present study, the capability of U. urealyticum to stimulate rat alveolar macrophages to produce nitric oxide (NO), express inducible nitric oxide synthase (iNOS), and activate nuclear factor κB (NF-κB) in vitro was characterized. The effect of NO on the growth of U. urealyticum was also investigated. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that U. urealyticum antigen (≥4 × 107 color-changing units/ml) stimulated alveolar macrophages to produce NO in a dose- and time-dependent manner (P < 0.05). This effect was further enhanced by gamma interferon (100 IU/ml; P < 0.05) but was attenuated by budesonide and dexamethasone (10−4 to 10−6 M) (P < 0.05). The mRNA and protein levels of iNOS were also induced in response to U. urealyticum and inhibited by steroids.U. urealyticum antigen triggered NF-κB activation, a possible mechanism for the induced iNOS expression, which also was inhibited by steroids. NO induced by U. urealyticum caused a sixfold reduction of its own growth after infection for 10 h. Our findings imply that U. urealyticum may be an important factor in the development of CLD. The host defense response againstU. urealyticum infection may also be influenced by NO. The down-regulatory effect of steroids on NF-κB activation, iNOS expression, and NO production might partly explain the beneficial effect of steroids in neonates with CLD.


2001 ◽  
Vol 34 ◽  
pp. 83
Author(s):  
P.L. Majano ◽  
C. Garcia-Monzon ◽  
U. Latasa ◽  
E. Garcia-Trevijano ◽  
F.J. Corrales ◽  
...  

2008 ◽  
Vol 295 (1) ◽  
pp. L96-L103 ◽  
Author(s):  
Viktor Brovkovych ◽  
Xiao-Pei Gao ◽  
Evan Ong ◽  
Svitlana Brovkovych ◽  
Marie-Luise Brennan ◽  
...  

The myeloperoxidase (MPO)-hydrogen peroxide-halide system is an efficient oxygen-dependent antimicrobial component of polymorphonuclear leukocyte (PMN)-mediated host defense. However, MPO deficiency results in few clinical consequences indicating the activation of compensatory mechanisms. Here, we determined possible mechanisms protecting the host using MPO−/−mice challenged with live gram-negative bacterium Escherichia coli. We observed that MPO−/−mice unexpectedly had improved survival compared with wild-type (WT) mice within 5–12 h after intraperitoneal E. coli challenge. Lungs of MPO−/−mice also demonstrated lower bacterial colonization and markedly attenuated increases in microvascular permeability and edema formation after E. coli challenge compared with WT. However, PMN sequestration in lungs of both groups was similar. Basal inducible nitric oxide synthase (iNOS) expression was significantly elevated in lungs and PMNs of MPO−/−mice, and NO production was increased two- to sixfold compared with WT. Nitrotyrosine levels doubled in lungs of WT mice within 1 h after E. coli challenge but did not change in MPO−/−mice. Inhibition of iNOS in MPO−/−mice significantly increased lung edema and reduced their survival after E. coli challenge, but iNOS inhibitor had the opposite effect in WT mice. Thus augmented iNOS expression and NO production in MPO−/−mice compensate for the lack of HOCl-mediated bacterial killing, and the absence of MPO-derived oxidants mitigates E. coli sepsis-induced lung inflammation and injury.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Rafael Simone Saia ◽  
Fabíola Leslie Mestriner ◽  
Giuliana Bertozi ◽  
Fernando Queiróz Cunha ◽  
Evelin Capellari Cárnio

Cholecystokinin (CCK) was first described as a gastrointestinal hormone. However, apart from its gastrointestinal effects, studies have described that CCK also plays immunoregulatory roles. Taking in account the involvement of inducible nitric oxide synthase- (iNOS-) derived NO in the sepsis context, the present study was undertaken to investigate the role of CCK on iNOS expression in LPS-activated peritoneal macrophages. Our results revealed that CCK reduces NO production and attenuates the iNOS mRNA expression and protein formation. Furthermore, CCK inhibited the nuclear factor- (NF-)κB pathway reducing IκBαdegradation and minor p65-dependent translocation to the nucleus. Moreover, CCK restored the intracellular cAMP content activating the protein kinase A (PKA) pathway, which resulted in a negative modulatory role on iNOS expression. In peritoneal macrophages, the CCK-1R expression, but not CCK-2R, was predominant and upregulated by LPS. The pharmacological studies confirmed that CCK-1R subtype is the major receptor responsible for the biological effects of CCK. These data suggest an anti-inflammatory role for the peptide CCK in modulating iNOS-derived NO synthesis, possibly controlling the macrophage activation through NF-κB, cAMP-PKA, and CCK-1R pathways. Based on these findings, CCK could be used as an adjuvant agent to modulate the inflammatory response and prevent systemic complications commonly found during sepsis.


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