scholarly journals Impact of inducible nitric oxide synthase (iNOS) expression on triple negative breast cancer outcome and activation of EGFR and ERK signaling pathways

Oncotarget ◽  
2017 ◽  
Vol 8 (46) ◽  
pp. 80568-80588 ◽  
Author(s):  
Pablo Garrido ◽  
Aliaa Shalaby ◽  
Elaine M. Walsh ◽  
Nessa Keane ◽  
Mark Webber ◽  
...  
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.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Lorena M Amaral ◽  
Ana Carolina T Palei ◽  
Lucas C Pinheiro ◽  
Jonas T Sertorio ◽  
Danielle A Guimaraes ◽  
...  

The pathophysiology of preeclampsia (PE) is not entirely known. However, increased oxidative stress possibly leading to impaired nitric oxide activity has been implicated in the critical condition. Increased oxidative stress with increased levels of highly reactive species including superoxide may generate peroxynitrite. We examined the role of inducible nitric oxide synthase (iNOS) and oxidative stress in the reduced uterine perfusion pressure (RUPP) preeclampsia experimental model. METHODS: RUPP was induced in wistar rats. Pregnant rats in the RUPP group had their aortic artery clipped at day 14 of gestation. After a midline incision, a silver clip (0.203 mm) was placed around the aorta above the iliac bifurcation; silver clips (0.100 mm) were also placed on branches of both the right and left ovarian arteries that supply the uterus. Sham-operated (pregnant control rats) and RUPP rats were treated with oral vehicle or 1 mg/kg/day 1400W (iNOS inhibitor) for 5 days. Mean arterial pressure (MAP) and plasma levels of thiobarbituric acid-reactive species (TBARS) and total radical-trapping antioxidant potential (TRAP) were measured determined. Aortic iNOS expression (Western blotting) and reactive oxygen species (ROS; assessed by fluorescence microscopy with dihydroethidium-DHE) were measured. We found increased mean arterial pressure in RUPP compared with pregnant control rats (MAP= 128±1 vs. 100±1.8 mmHg, respectively; P<0.05) and 1400W exerted antihypertensive effects (MAP= 114±2 vs.128±1 mmHg in RUPP treated and untreated rats, respectively; P<0.05). Higher reactive oxygen species (ROS) concentrations were found in RUPP compared with pregnant control rats (7.1±0.5 vs. 5.1±0.5 arbitrary units (A.U.), respectively; P<0.05) and 1400W decreased ROS production to 5.8±0.02 A.U. in RUPP treated rats, P<0.05. In addition, 1400W attenuated iNOS expression in RUPP rats (0.29±0.02 vs. 0.55±0.8 A.U. in RUPP treated and untreated rats, respectively; P<0.01) and had no effects on plasma TBARS and TRAP levels. Our results suggest that 1400w exerts antihypertensive effects in the RUPP model and suppresses ROS formation. Supported by FAPESP,Cnpq.


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.


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