Modulation of Inducible Nitric Oxide Synthase by Hypoxia in Pulmonary  Artery Endothelial Cells

Zulueta, Javier; Sawhney, Raneeta; Kayyali, Usamah S.; Fogel, Michael; Donaldson, Cameron; Huang, Hailu; Lanzillo, Joseph J.; Hassoun, Paul M.

doi:10.1165/ajrcmb.26.1.4510

Cited by 35 publications

(27 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A number of groups have studied in vitro models to assess the effect of hypoxia on NOS2 production, also finding conflicting results in different cell types. Whereas in bovine pulmonary artery endothelial cells hypoxia induces NOS2 promoter activity (58), results presented herein and by others (56) show that hypoxia has no effect on RPMVECs. These differences could be explained by the phenotypic heterogeneity of endothelial cells obtained from different pulmonary blood vessels or from different species (64)(65)(66).…”

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymacontrasting

confidence: 48%

“…Our in vitro experiments also failed to show induction of NOS2 in alveolar epithelial cells and RPMVECs in response to LPS. Other investigations have shown induction of NOS2 in RPMVECs, although in response to tumor necrosis factor-␣ and interleukin-1␤ (56). This may suggest that stimuli other than LPS are needed for NOS2 induction in this cell line.…”

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymamentioning

confidence: 66%

“…If anything, in the macrophage cell line (CRL-2192) hypoxia attenuated the LPS-dependent increase in NOS2 mRNA ( Figure 9). Others have also shown in RPMVECs that hypoxia attenuates LPS-dependent NOS2 upregulation (56). This further suggests that the increased expression of NOS2 in whole lung tissue after treatment with LPS and hypoxia is due to the recruitment of a greater number of cells that express NOS2 (monocytes, neutrophils, and lymphocytes), and not because of upregulated expression in pulmonary resident cells.…”

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymamentioning

confidence: 82%

See 2 more Smart Citations

Effects of Acute Hypoxia and Lipopolysaccharide on Nitric Oxide Synthase-2 Expression in Acute Lung Injury

Agorreta

Garayoa²,

Montuenga³

et al. 2003

Am J Respir Crit Care Med

Self Cite

View full text Add to dashboard Cite

The potential role of nitric oxide synthase-2 (NOS2) in acute lung injury (ALI) has gained increasing attention. This study evaluates the effects of hypoxia, an important feature of ALI, on NOS2 expression in a rat model of ALI caused by exposure to hypoxia and LPS. Exposure to hypoxia alone had no effect on the expression of NOS2 in rat lungs. LPS treatment resulted in a significant increase in NOS2 in the lungs, which was further enhanced by concomitant exposure to hypoxia. Immunohistochemical analysis and in situ hybridization showed no changes in the expression of NOS2 in lung resident cells under any conditions. The increase in NOS2 levels is mainly due to the influx of NOS2-expressing inflammatory cells. By morphologic analysis, these inflammatory cells were identified as neutrophils, lymphocytes, and monocytes. In vitro experiments of lung epithelial and endothelial cell lines showed no detectable expression of NOS2 with any of the treatments. In a macrophage cell line, LPS-induced NOS2 expression was not affected by the concomitant exposure to hypoxia. In conclusion, LPS increases NOS2 expression in rat lungs through the recruitment of NOS2-producing leukocytes. Simultaneous exposure to LPS and hypoxia results in a greater influx of inflammatory cells that further enhances NOS2 expression.Keywords: acute respiratory distress syndrome; endotoxin; leukocytes; sepsis Nitric oxide (·NO) is a multifunctional, short-lived gas that may contribute to toxic free radical production and potentiate lung injury. ·NO is synthesized by a family of enzymes called nitric oxide synthases (NOS). There are three NOS isoforms, namely, NOS1 (neuronal NOS), NOS2 (inducible NOS), and NOS3 (endothelial NOS). These isoenzymes were first purified from rat brain (1), murine macrophages (2), and bovine aortic endothelial cells (3), respectively. NOS enzymes are classically classified as either constitutive (NOS1 and NOS3) or inducible (NOS2), although it is now known that the expression of NOS1 and NOS3 can be induced (4), and that NOS2 is constitutively expressed in numerous cell types (5). The so-called constitutive isoforms (NOS1 and NOS3) release low amounts of ·NO and their activity is dependent on calcium and calmodulin (6). On the other hand, NOS2 produces large amounts of ·NO after induction by stimuli such as endotoxin and inflammatory cytokines (7-9). All three isoenzymes have been found in the lung (10-12) and mediate a wide variety of biological events in the respiratory system, (Received in original form September 11, 2002; accepted in final form May 16, 2003) Supported by the Spanish Ministry of Health (FIS 00/0698 and RTIC C03/10) and the Fundació n Echébano.Correspondence and requests for reprints should be addressed to Javier J. Zulueta, M.D., Pulmonary Medicine Service, Clínica Universitaria de Navarra, University of Navarra, Avenida Pío XII, 36, 31008 Pamplona, Spain. E-mail: jzulueta@unav.es This article has an online supplement, which is accessible from this issue's table of contents online at www.atsjournals...

show abstract

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymacontrasting

confidence: 48%

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymamentioning

confidence: 66%

Section: Nos2-expressing Inflammatory Cells In the Lung Parenchymamentioning

confidence: 82%

See 1 more Smart Citation

Effects of Acute Hypoxia and Lipopolysaccharide on Nitric Oxide Synthase-2 Expression in Acute Lung Injury

Agorreta

Garayoa²,

Montuenga³

et al. 2003

Am J Respir Crit Care Med

Self Cite

View full text Add to dashboard Cite

show abstract

“…Western blotting was performed as previously described (14,15) after tissue homogenates were prepared and protein quantified by bicinchoninic acid assay (Pierce, Rockford, IL).…”

Section: Immunoblottingmentioning

confidence: 99%

Inducible Nitric Oxide Synthase Contributes to Ventilator-induced Lung Injury

Peng

Abdulnour

Sammani

et al. 2005

Am J Respir Crit Care Med

Self Cite

View full text Add to dashboard Cite

Rationale: Inducible nitric oxide synthase (iNOS) has been implicated in the development of acute lung injury. Recent studies indicate a role for mechanical stress in iNOS and endothelial NOS (eNOS) regulation. Objectives: This study investigated changes in lung NOS expression and activity in a mouse model of ventilatorinduced lung injury. Methods: C57BL/6J (wild-type [WT]) and iNOSdeficient (iNOS Ϫ/Ϫ ) mice received spontaneous ventilation (control) or mechanical ventilation (MV; VT of 7 and 20 ml/kg) for 2 hours, after which NOS gene expression and activity were determined and pulmonary capillary leakage assessed by the Evans blue albumin assay. Results: iNOS mRNA and protein expression was absent in iNOS Ϫ/Ϫ mice, minimal in WT control mice, but significantly upregulated in response to 2 hours of MV. In contrast, eNOS protein was decreased in WT mice, and nonsignificantly increased in iNOS Ϫ/Ϫ mice, as compared with control animals. iNOS and eNOS activities followed similar patterns in WT and iNOS Ϫ/Ϫ mice. MV caused acute lung injury as suggested by cell infiltration and nitrotyrosine accumulation in the lung, and a significant increase in bronchoalveolar lavage cell count in WT mice, findings that were reduced in iNOS Ϫ/Ϫ mice. Finally, Evans blue albumin accumulation in lungs of WT mice was significant (50 vs. 15% increase in iNOS Ϫ/Ϫ mice compared with control animals) in response to MV and was prevented by treatment of the animals with the iNOS inhibitor aminoguanidine. Conclusion: Taken together, our results indicate that iNOS gene expression and activity are significantly upregulated and contribute to lung edema in ventilator-induced lung injury.Keywords: inducible nitric oxide synthase; lung permeability; mechanical ventilation Nitric oxide (NO) is involved in many physiologic and pathologic conditions, such as blood vessel relaxation, neurotransmission, and host defense. NO also plays a critical role in tissue injury in the context of various inflammatory conditions (1). NO is produced by three isoforms (neuronal, endothelial, and inducible) of NO synthase (NOS). Endothelial NOS (eNOS), which is calcium/calmodulin (Ca 2ϩ /CaM)-dependent and activated by agonists (e.g., acetylcholine), produces a low level of NO output, whereas inducible NOS (iNOS) is independent of Ca 2ϩ /CaM, is transcriptionally regulated by proinflammatory products (e.g., LPS) and cytokines (interleukin 1␤ [IL-1␤], tumor necrosis factor ␣ [TNF-␣], IFN-␥), and results in sustained and elevated (Received in original form November 19, 2004; accepted in final form May 20, 2005) Supported by awards from the National Heart, Lung, and Blood Institute (NIH R01 HL049441 and P50 HL 73994).* These authors contributed equally to the work presented in this article. release of NO (2). Therefore, overproduction of NO, in particular in the setting of superoxide production (3), leads to oxidative stress and tissue injury in conditions such as endotoxin-induced acute lung injury (ALI) (4).ALI is characterized by a severe inflammatory process, pr...

show abstract

“…Both HPAECs and HPASMCs were isolated from non-smoking controls, as it has been shown that after normal culture conditions for 1-4 passages in the absence of an inflammatory environment, the expression of iNOS returns to basal levels [20].…”

Section: Effect Of Cse On No Release In Hpaecs and Hpasmcsmentioning

confidence: 99%

Direct effect of cigarette smoke on human pulmonary artery tension

Ortiz¹,

Milara²,

Juan³

et al. 2010

Pulmonary Pharmacology & Therapeutics

View full text Add to dashboard Cite

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. M A N U S C R I P T A C C E P T E D ARTICLE IN PRESS M A N U S C R I P T A C C E P T E D ARTICLE IN PRESS2 AbstractThe effect of chronic cigarette smoke on pulmonary artery (PA) tension has been studied extensively; nevertheless, the direct effect of cigarette smoke is poorly understood. We investigated the direct effect of cigarette smoke extract (CSE) on PA tension in non-smokers, smokers, and COPD patients in vitro. PA samples from 35 patients who underwent lung resection were examined by measuring isometric tension in response to increasing serotonin concentrations. CSE dose-dependently inhibited the response to serotonin in smokers and COPD patients, and to a lesser extent in nonsmokers. CSE-induced relaxation was similarly inhibited by the nonspecific nitric oxide synthase (NOS) inhibitor L-NOARG and the specific inducible NOS (iNOS) inhibitor L-NIL, mainly in non-smokers and smokers, and to a lesser extent in COPD patients.Immunostaining of iNOS in PA samples was greater for smokers and COPD patients compared with non-smokers, which explains the lesser effect of CSE on PA tension in non-smokers. Moreover, CSE induced the release of nitrite via iNOS in human PA smooth muscle cells. In conclusion, CSE inhibition of serotonin-induced PA contraction was mediated mainly by iNOS in non-smokers, smokers, and COPD patients, but in different ways, which may be explained by differential iNOS expression in the PA of these patients.

show abstract

Modulation of Inducible Nitric Oxide Synthase by Hypoxia in Pulmonary Artery Endothelial Cells

Cited by 35 publications

References 45 publications

Effects of Acute Hypoxia and Lipopolysaccharide on Nitric Oxide Synthase-2 Expression in Acute Lung Injury

Effects of Acute Hypoxia and Lipopolysaccharide on Nitric Oxide Synthase-2 Expression in Acute Lung Injury

Inducible Nitric Oxide Synthase Contributes to Ventilator-induced Lung Injury

Direct effect of cigarette smoke on human pulmonary artery tension

Contact Info

Product

Resources

About