iNOS activity is essential for endothelial stress gene expression protecting against oxidative damage

2003 ◽  
Vol 95 (5) ◽  
pp. 1937-1946 ◽  
Author(s):  
Karsten Hemmrich ◽  
Christoph V. Suschek ◽  
Guido Lerzynski ◽  
Victoria Kolb-Bachofen
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Stress Response ◽  
Endothelial Function ◽  
Protective Role ◽  
Inos Expression ◽  
Heme Oxygenase 1 ◽  
Inos Protein ◽  
Inos Protein Expression ◽  
Exogenous Substrate

In endothelial cells, the expression of the inducible nitric oxide synthase (iNOS) and the resulting high-output nitric oxide synthesis have often been assumed as detrimental to endothelial function, but recent publications have demonstrated a protective role resulting from iNOS espression and activity. To address this question, we used antisense-mediated iNOS knockdown during proinflammatory cytokine challenge in primary endothelial cell cultures and studied endothelial function by monitoring the expression of stress defense genes. Using antisense oligonucleotides, we achieved a block of iNOS protein formation, accompanied by a strong decrease in the expression of the protective stress response genes bcl-2, vascular endothelial growth factor, and heme oxygenase-1 (HO-1). Additionally, cells were also maintained in the presence of limited exogenous substrate concentrations during cytokine challenge, thereby mimicking a situation of low serum arginine level during inflammation. Under these conditions, cytokine addition results in full iNOS protein expression with minimal nitric oxide formation, concomitant with a significant reduction in stress response gene expression and susceptibility to cell death induced by reactive oxygen species. Taken together, our data suggest that cytokine-induced endogenous iNOS expression and activity have key functions in increasing endothelial survival and maintaining function. Thus suppression of iNOS expression or limited substrate supply, as has been reported to occur in atherosclerosis patients, appears to significantly contribute to endothelial dysfunction and death during oxidative stress.

scholarly journals Effect of ACEI and ARB treatment on nitric oxide-dependent endothelial function

VASA ◽  
2021 ◽  
Author(s):  
Kangbo Li ◽  
Claudia Zemmrich ◽  
Peter Bramlage ◽  
Anja Bondke Persson ◽  
Mesud Sacirovic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Angiotensin Converting Enzyme ◽  
Endothelial Function ◽  
Mononuclear Cells ◽  
Mrna Level ◽  
Converting Enzyme ◽  
Bradykinin Receptors ◽  
Artery Disease ◽  
Nitrite Nitrate

Summary: Background: Angiotensin-converting-enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) are widely used as a first-line therapy for the treatment of cardiovascular disease. Here, ACEI modulate the bradykinin receptor (BDKRB1 and BDKRB2) system and NO-dependent endothelial function, thus determining cardiovascular health and regenerative arteriogenesis. The current study aims at evaluating nitric oxide-dependent endothelial function, and gene expression of bradykinin receptors in peripheral blood mononuclear cells (PBMC) from patients with ACEI or ARB treatment. Patients and methods: The WalkByLab has been established to screen cardiovascular patients for peripheral artery disease and coronary artery disease. In total 177 patients from WalkByLab with heterogenous disease and risk status were randomly selected, divided according to their medication history into the following groups: 1. ACEI group, 2. ARB group or 3. non-ACE/ARB group. Total plasma nitrite/nitrate (NO) levels were measured, endothelial function was evaluated by assessing flow meditated dilation (FMD). PBMC were isolated from peripheral whole blood, and gene expression (qRT-PCR) of bradykinin receptors and angiotensin converting enzyme were assessed. Results: Plasma total NO concentration in the ACEI group (24.66±16.28, µmol/l) was increased as compared to the ARB group (18.57±11.58, µmol/l, P=0.0046) and non-ACE/ARB group (16.83±8.64, µmol/l, P=0.0127) in patients between 40 to 90 years of age. However, FMD values (%) in the ACEI group (7.07±2.40, %) were similar as compared to the ARB (6.35±2.13, %) and non-ACE/ARB group (6.51±2.15, %), but significantly negatively correlated with age. Interestingly, BDKRB1 mRNA level was significantly higher and BDKRB2 mRNA level lower in the ACEI group (BDKRB1 3.88-fold±1.05, BDKRB2 0.22-fold±0.04) as compared to the non-ACE/ARB group (BDKRB1 1.00-fold±0.39, P<0.0001, BDKRB2 1.00-fold±0.45, P=0.0136). Conclusions: ACEI treatment enhances total nitrite/nitrate concentration, furthermore, upregulates BDKRB1 in PBMC, but downregulates BDKRB2 mRNA expression. FMD is a strong determinant of vascular aging and is sensitive to underlying heterogenous cardiovascular diseases.

Rgx365, a Rare Protopanaxatriol-Type Ginsenoside Fraction from Black Ginseng, Suppresses Inflammatory Gene iNOS via the Iinhibition of p-STAT-1 and NF-κB

2020 ◽  
Vol 48 (05) ◽  
pp. 1091-1102
Author(s):  
So Yeon Jeong ◽  
Ji-Eun Kim ◽  
Gyu-Yong Song ◽  
Jong-Sup Bae
Keyword(s):  
Lung Tissue ◽  
Lavage Fluid ◽  
Heme Oxygenase 1 ◽  
Inos Protein ◽  
Protein Levels ◽  
Rna Transfection ◽  
Inos Protein Expression ◽  
Black Ginseng ◽  
Cox 2 ◽  
Human Pulmonary Artery

Black ginseng (BG), which is ginseng that has been steamed and dried nine times, and its main protopanaxatriol-type ginsenosides Rg4, Rg6, Rh4, and Rg2 have been reported to exhibit various forms of biological activity, including antiseptic, antidiabetic, wound-healing, immune-stimulatory, and anti-oxidant activity. The aim of the this study was to examine the effects of [Formula: see text] (a rare protopanaxatriol-type ginsenoside fraction; Rg2, Rg4, Rg6, Rh1, and Rh4) on heme oxygenase-1 (HO-1) induction and on the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-)2 in lipopolysaccharide (LPS)-activated human pulmonary artery endothelial cells (HPAECs). [Formula: see text] was tested to determine its effect on iNOS protein expression and inflammatory markers (interleukin [IL]-1[Formula: see text] and tumor necrosis factor [TNF]-[Formula: see text] in the lung tissue of LPS-treated mice. The results showed that [Formula: see text] induced the expression of HO-1, reduced LPS-activated NF-[Formula: see text]B-luciferase activity, and inhibited iNOS/NO and COX-2/PGE2, which contributed to the inhibition of STAT-1 phosphorylation. In particular, [Formula: see text] induced the translocation of Nrf2 from the cytosol to the nucleus by increasing Nrf2-ARE activity and decreased IL-1[Formula: see text] production in LPS-activated HPAECs. This reduction in iNOS/NO expression due to [Formula: see text] was reversed by siHO-1 RNA transfection. In LPS-treated mice, [Formula: see text] significantly reduced lung tissue iNOS protein levels and TNF-[Formula: see text] levels in the bronchoalveolar lavage fluid. In conclusion, these findings indicate that [Formula: see text] has a critical anti-inflammatory effect due to its ability to regulate iNOS via the inhibition of p-STAT-1 and NF-[Formula: see text]B, and thus it may be suitable for the treatment of inflammatory disease.

scholarly journals l-Arginine Availability Regulates Inducible Nitric Oxide Synthase-Dependent Host Defense against Helicobacter pylori

2007 ◽  
Vol 75 (9) ◽  
pp. 4305-4315 ◽  
Author(s):  
Rupesh Chaturvedi ◽  
Mohammad Asim ◽  
Nuruddeen D. Lewis ◽  
Holly M. Scott Algood ◽  
Timothy L. Cover ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Helicobacter Pylori ◽  
Protein Expression ◽  
Translation Initiation Factor ◽  
No Production ◽  
Dependent Manner ◽  
Inos Protein ◽  
Inos Protein Expression ◽  
H Pylori ◽  
Inducible Nitric Oxide

ABSTRACT Helicobacter pylori infection of the stomach causes an active immune response that includes stimulation of inducible nitric oxide (NO) synthase (iNOS) expression. Although NO can kill H. pylori, the bacterium persists indefinitely, suggesting that NO production is inadequate. We determined if the NO derived from iNOS in macrophages was dependent on the availability of its substrate, l-arginine (l-Arg). Production of NO by H. pylori-stimulated RAW 264.7 cells was dependent on the l-Arg concentration in the culture medium, and the 50% effective dose for l-Arg was 220 μM, which is above reported plasma l-Arg levels. While iNOS mRNA induction was l-Arg independent, iNOS protein increased in an l-Arg-dependent manner that did not involve changes in iNOS protein degradation. l-Lysine, an inhibitor of l-Arg uptake, attenuated H. pylori-stimulated iNOS protein expression, translation, NO levels, and killing of H. pylori. While l-Arg starvation suppressed global protein translation, at concentrations of l-Arg at which iNOS protein was only minimally expressed in response to H. pylori, global translation was fully restored and eukaryotic translation initiation factor α was dephosphorylated. H. pylori lacking the gene rocF, which codes for a bacterial arginase, induced higher levels of NO production by increasing iNOS protein levels. When murine gastric macrophages were activated with H. pylori, supraphysiologic levels of l-Arg were required to permit iNOS protein expression and NO production. These findings indicate that l-Arg is rate limiting for iNOS translation and suggest that the levels of l-Arg that occur in vivo do not permit sufficient NO generation by the host to kill H. pylori.

scholarly journals iNOS Associates With Poor Survival in Melanoma: A Role for Nitric Oxide in the PI3K-AKT Pathway Stimulation and PTEN S-Nitrosylation

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhen Ding ◽  
Dai Ogata ◽  
Jason Roszik ◽  
Yong Qin ◽  
Sun-Hee Kim ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Expression ◽  
Nitrosative Stress ◽  
Akt Pathway ◽  
Melanoma Tumor ◽  
Inos Protein ◽  
Akt Activation ◽  
Inos Protein Expression ◽  
Patient Prognosis

We previously showed that inducible nitric oxide synthase (iNOS) protein expression in melanoma tumor cells is associated with poor patient prognosis. Here, we analyzed the association between iNOS and the oncogenic PI3K-AKT pathway. TCGA data show that iNOS and phospho-Akt Ser473 expression were associated significantly only in the subset of tumors with genetically intact PTEN. Employing a stage III melanoma TMA, we showed that iNOS protein presence is significantly associated with shorter survival only in tumors with PTEN protein expression. These findings led to our hypothesis that the iNOS product, nitric oxide (NO), suppresses the function of PTEN and stimulates PI3K-Akt activation. Melanoma cells in response to NO exposure in vitro exhibited enhanced AKT kinase activity and substrate phosphorylation, as well as attenuated PTEN phosphatase activity. Biochemical analysis showed that NO exposure resulted in a post-translationally modified S-Nitrosylation (SNO) PTEN, which was also found in cells expressing iNOS. Our findings provide evidence that NO-rich cancers may exhibit AKT activation due to post-translational inactivation of PTEN. This unique activation of oncogenic pathway under nitrosative stress may contribute to the pathogenesis of iNOS in melanoma. Significance: Our study shows that iNOS expression is associated with increased PI3K-AKT signaling and worse clinical outcomes in melanoma patients with wt (intact) PTEN. Mutated PTEN is already inactivated. We also demonstrate that NO activates the PI3K-AKT pathway by suppressing PTEN suppressor function concurrent with the formation of PTEN-SNO. This discovery provides insight into the consequences of inflammatory NO produced in human melanoma and microenvironmental cells. It suggests that NO–driven modification provides a marker of PTEN inactivation, and represents a plausible mechanism of tumor suppressor inactivation in iNOS expressing subset of cancers.

scholarly journals Vagus Nerve Stimulation Ameliorates Renal Ischemia-Reperfusion Injury through Inhibiting NF-κB Activation and iNOS Protein Expression

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Meng Wang ◽  
Jielin Deng ◽  
Huanzhu Lai ◽  
Yanqiu Lai ◽  
Guannan Meng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Inos Expression ◽  
Inos Protein ◽  
Inos Protein Expression ◽  
Renal Ischemia Reperfusion Injury

Objective. In renal ischemia/reperfusion injury (RIRI), nuclear factor κB (NF-κB) initiates the expression of multiple genes involved in inflammatory disease. Inhibition of NF-κB-mediated inducible nitric oxide synthase (iNOS) expression can ameliorate RIRI. Vagus nerve stimulation (VNS) protects against various organs I/R injury. The present study was designed to elucidate the protective effect of VNS on RIRI and its influence on iNOS protein expression. Methods. Eighteen male Sprague-Dawley rats were randomly allocated into the sham group, the I/R group, and the VNS+I/R group, 6 rats per group. An RIRI model was induced by a right nephrectomy and blockade of the left renal pedicle vessels for 45 min. After 6 h of reperfusion, the blood samples and renal samples were collected. The VNS treatment was performed throughout the I/R process in the VNS+I/R group using specific parameters (20 Hz, 0.1 ms in duration, square waves) known to produce a small but reliable bradycardia. Blood was used for evaluation of renal function and inflammatory state. Renal injury was evaluated via TUNEL staining. Renal samples were harvested to evaluate renal oxidative stress, NF-κB p65 levels, and iNOS protein expression. Results. The VNS treatment reduces serum creatinine (Cr) and blood urea nitrogen (BUN) levels. Simultaneously, the levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1-beta (IL-1β) were significantly increased in the I/R group, but VNS treatment markedly ameliorated this inflammatory response. Furthermore, the VNS ameliorated oxidant stress and renal injury, indicated by a decrease in 3-nitrotyrosine (3-NT) formation and MDA and MPO levels and an increase in the SOD level compared to that in the I/R group. Finally, the VNS also significantly decreases NF-κB p65, iNOS, and nitrite/nitrate levels compared to that in the I/R group. Conclusion. Our findings indicate that NF-κB activation increased iNOS expression and promoted RIRI and that VNS treatment attenuated RIRI by inhibiting iNOS expression, oxidative stress, and inflammation via NF-κB inactivation.

Protective role of Salvia miltiorrhiza Polysaccharides on Florfenicol Induced Oxidative and Apoptotic Injury of Liver in Broilers

2021 ◽  
Author(s):  
Xiao Wang ◽  
Yuqing Cui ◽  
Chao Han ◽  
Yumeng Geng ◽  
Di Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Liver Injury ◽  
Protein Expression ◽  
Liver Tissue ◽  
Salvia Miltiorrhiza ◽  
Protective Role ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Mrna And Protein Expression ◽  
Liver Tissues

Abstract Salvia miltiorrhiza Polysaccharides (SMPs) can alleviate liver injury in mice, but there are few reports on liver injury of broilers, especially the liver injury caused by antibiotics. To explore the hepatoprotective effects of SMPs against florfenicol (FFC) induced broilers liver injury, the broilers were treated with FFC and SMPs. The results showed SMPs could significantly inhibit the decrease of weight gain and the increase of liver index induced by FFC (P < 0.05). SMPs could significantly reduce the contents of Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) in serum and the malondialdehyde (MDA), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in liver tissues (P < 0.05), also significantly increased the content of total protein (TP) in serum and superoxide dismutase (SOD), catalase (CAT) in liver tissues (P < 0.05). QPCR and western bolt results showed that SMPs significantly increased the mRNA and protein expression of cytochrome P4501A1 (CYP1A1), cytochrome P4502H1 (CYP2H1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone-1 (NQO-1) in liver tissue, also significantly reduced the rate of hepatocyte apoptosis and the mRNA and protein expression of p53, cytochrome-C (CytC), caspase-3 in liver tissue (P < 0.05). The results demonstrated that SMPs can inhibit the oxidative stress in hepatocytes by regulating the related proteins in Nrf2 pathway, thereby reducing the apoptosis of hepatocytes, and protecting liver injury.

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