Diabetes induces pulmonary artery endothelial dysfunction by NADPH oxidase induction

2008 ◽  
Vol 295 (5) ◽  
pp. L727-L732 ◽  
Author(s):  
Jose G. Lopez-Lopez ◽  
Javier Moral-Sanz ◽  
Giovanna Frazziano ◽  
Maria J. Gomez-Villalobos ◽  
Jorge Flores-Hernandez ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
Pulmonary Arteries ◽  
Diabetic Rats ◽  
Oxidase Inhibitor ◽  
No Synthase ◽  
Superoxide Production ◽  
Regulatory Subunit ◽  
Sprague Dawley ◽  
Relaxant Response

Recent data suggest that diabetes is a risk factor for pulmonary hypertension. The aim of the present study was to analyze whether diabetes induces endothelial dysfunction in pulmonary arteries and the mechanisms involved. Male Sprague-Dawley rats were randomly divided into a control (saline) and a diabetic group (70 mg/kg−1 streptozotocin). After 6 wk, intrapulmonary arteries were mounted for isometric tension recording, and endothelial function was tested by the relaxant response to acetylcholine. Protein expression and localization were measured by Western blot and immunohistochemistry and superoxide production by dihydroethidium staining. Pulmonary arteries from diabetic rats showed impaired relaxant response to acetylcholine and reduced vasoconstrictor response to the nitric oxide (NO) synthase inhibitor l-NAME, whereas the response to nitroprusside and the expression of endothelial NO synthase remained unchanged. Endothelial dysfunction was reversed by addition of superoxide dismutase or the NADPH oxidase inhibitor apocynin. An increase in superoxide production and increased expression of the NADPH oxidase regulatory subunit p47phox were also found in pulmonary arteries from diabetic rats. In conclusion, the pulmonary circulation is a target for diabetes-induced endothelial dysfunction via enhanced NADPH oxidase-derived superoxide production.

scholarly journals Apocynin improves oxygenation and increases eNOS in persistent pulmonary hypertension of the newborn

2012 ◽  
Vol 302 (6) ◽  
pp. L616-L626 ◽  
Author(s):  
Stephen Wedgwood ◽  
Satyan Lakshminrusimha ◽  
Kathryn N. Farrow ◽  
Lyubov Czech ◽  
Sylvia F. Gugino ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Nadph Oxidase ◽  
Ductus Arteriosus ◽  
Pulmonary Arteries ◽  
Oxidase Inhibitor ◽  
No Synthase ◽  
Persistent Pulmonary Hypertension ◽  
No Donor ◽  
Oxidase Inhibition ◽  
Endothelial Nitric Oxide

NADPH oxidase is a major source of superoxide anions in the pulmonary arteries (PA). We previously reported that intratracheal SOD improves oxygenation and restores endothelial nitric oxide (NO) synthase (eNOS) function in lambs with persistent pulmonary hypertension of the newborn (PPHN). In this study, we determined the effects of the NADPH oxidase inhibitor apocynin on oxygenation, reactive oxygen species (ROS) levels, and NO signaling in PPHN lambs. PPHN was induced in lambs by antenatal ligation of the ductus arteriosus 9 days prior to delivery. Lambs were treated with vehicle or apocynin (3 mg/kg intratracheally) at birth and then ventilated with 100% O2 for 24 h. A significant improvement in oxygenation was observed in apocynin-treated lambs after 24 h of ventilation. Contractility of isolated fifth-generation PA to norepinephrine was attenuated in apocynin-treated lambs. PA constrictions to NO synthase (NOS) inhibition with N-nitro-l-arginine were blunted in PPHN lambs; apocynin restored contractility to N-nitro-l-arginine, suggesting increased NOS activity. Intratracheal apocynin also enhanced PA relaxations to the eNOS activator A-23187 and to the NO donor S-nitrosyl- N-acetyl-penicillamine. Apocynin decreased the interaction between NADPH oxidase subunits p22phox and p47phox and decreased the expression of Nox2 and p22phox in ventilated PPHN lungs. These findings were associated with decreased superoxide and 3-nitrotyrosine levels in the PA of apocynin-treated PPHN lambs. eNOS protein expression, endothelial NO levels, and tetrahydrobiopterin-to-dihydrobiopterin ratios were significantly increased in PA from apocynin-treated lambs, although cGMP levels did not significantly increase and phosphodiesterase-5 activity did not significantly decrease. NADPH oxidase inhibition with apocynin may improve oxygenation, in part, by attenuating ROS-mediated vasoconstriction and by increasing NOS activity.

scholarly journals Increased superoxide production contributes to the impaired angiogenesis of fetal pulmonary arteries with in utero pulmonary hypertension

2009 ◽  
Vol 297 (1) ◽  
pp. L184-L195 ◽  
Author(s):  
Ru-Jeng Teng ◽  
Annie Eis ◽  
Ivane Bakhutashvili ◽  
Nandini Arul ◽  
Girija G. Konduri
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Hypertension ◽  
Nadph Oxidase ◽  
Ductus Arteriosus ◽  
Pulmonary Arteries ◽  
Tube Formation ◽  
Oxidase Inhibitor ◽  
Superoxide Production ◽  
Mrna Levels ◽  
Impaired Angiogenesis

Persistent pulmonary hypertension of newborn (PPHN) is associated with impaired pulmonary vasodilation at birth. Previous studies demonstrated that a decrease in angiogenesis contributes to this failure of postnatal adaptation. We investigated the hypothesis that oxidative stress from NADPH oxidase (Nox) contributes to impaired angiogenesis in PPHN. PPHN was induced in fetal lambs by ductus arteriosus ligation at 85% of term gestation. Pulmonary artery endothelial cells (PAEC) from fetal lambs with PPHN (HTFL-PAEC) or control lambs (NFL-PAEC) were compared for their angiogenic activities and superoxide production. HTFL-PAEC had decreased tube formation, cell proliferation, scratch recovery, and cell invasion and increased cell apoptosis. Superoxide (O2−) production, measured by dihydroethidium epifluorescence and HPLC, were increased in HTFL-PAEC compared with NFL-PAEC. The mRNA levels for Nox2, Rac1, p47phox, and Nox4, protein levels of p67phox and Rac1, and NADPH oxidase activity were increased in HTFL-PAEC. NADPH oxidase inhibitor, apocynin (Apo), and antioxidant, N-acetyl-cysteine (NAC), improved angiogenic measures in HTFL-PAEC. Apo and NAC also reduced apoptosis in HTFL-PAEC. Our data suggest that PPHN is associated with increased O2− production from NADPH oxidase in PAEC. Increased oxidative stress from NADPH oxidase contributes to the impaired angiogenesis of PAEC in PPHN.

scholarly journals NADPH Oxidase Inhibitor Apocynin Attenuates PCB153-Induced Thyroid Injury in Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ablikim Abliz ◽  
Chen Chen ◽  
Wenhong Deng ◽  
Weixing Wang ◽  
Rongze Sun
Keyword(s):  
Thyroid Hormone ◽  
Nadph Oxidase ◽  
Inflammatory Cytokines ◽  
Thyroid Dysfunction ◽  
Thyroid Tissue ◽  
Oxidase Inhibitor ◽  
Control Group ◽  
Ros Generation ◽  
Sprague Dawley ◽  
Serum Thyroid Hormone

PCBs, widespread endocrine disruptors, cause the disturbance of thyroid hormone (TH) homeostasis in humans and animals. However, the exact mechanism of thyroid dysfunction caused by PCBs is still unknown. In order to clarify the hypotheses that NADPH oxidase (NOX) and subsequent NF-κB pathway may play roles in thyroid dysfunction, sixty Sprague-Dawley rats were randomly divided into four groups: control group, PCB153 treated (PCB) group, received apocynin with PCB153 treatment (APO + PCB) group, and drug control (APO) group. Serum thyroid hormone levels were evaluated. The morphological change of thyroid tissue was analyzed under the light and transmission electron microscopy. NOX2, 8-OHdG, and NF-κB expression in the thyroid tissue was evaluated by immune-histochemical staining. Oxidative stress and inflammatory cytokines were detected. The following results were reduced after apocynin treatment: (1) serum thyroid hormone, (2) thyroid pathological injuries, (3) thyroid MDA, (4) thyroid ultrastructural change, (5) serum inflammatory cytokines, and (6) thyroid expression of NOX2, 8-OHdG, and NF-κB. These results suggested that NOX inhibition attenuates thyroid dysfunction induced by PCB in rats, presumably because of its role in preventing ROS generation and inhibiting the activation of NF-κB pathway. Our findings may provide new therapeutic targets for PCBs induced thyroid dysfunction.

scholarly journals Olfactomedin 4 contributes to hydrogen peroxide-induced NADPH oxidase activation and apoptosis in mouse neutrophils

2018 ◽  
Vol 315 (4) ◽  
pp. C494-C501 ◽  
Author(s):  
Wenli Liu ◽  
Yueqin Liu ◽  
Hongzhen Li ◽  
Griffin P. Rodgers
Keyword(s):  
Hydrogen Peroxide ◽  
Nadph Oxidase ◽  
Molecular Mechanisms ◽  
Oxidase Inhibitor ◽  
Superoxide Production ◽  
Wild Type ◽  
Escherichia Coli Bacteria ◽  
Induced Apoptosis ◽  
Nadph Oxidase Activation ◽  
Deficient Mice

Neutrophils increase production of reactive oxygen species, including superoxide, hydrogen peroxide (H2O2), and hydroxyl radical, to destroy invading microorganisms under pathological conditions. Conversely, oxidative stress conditions, such as the presence of H2O2, induce neutrophil apoptosis, which helps to remove neutrophils after inflammation. However, the detailed molecular mechanisms that are involved in the latter process have not been elucidated. In this study, we investigated the potential role of olfactomedin 4 (Olfm4) in H2O2-induced superoxide production and apoptosis in mouse neutrophils. We have demonstrated that Olfm4 is not required for maximal-dosage PMA- and Escherichia coli bacteria-induced superoxide production, but Olfm4 contributes to suboptimal-dosage PMA- and H2O2-induced superoxide production. Using an NADPH oxidase inhibitor and gp91phox-deficient mouse neutrophils, we found that NAPDH oxidase was required for PMA-stimulated superoxide production and that Olfm4 mediated H2O2-induced superoxide production through NADPH oxidase, in mouse neutrophils. We have shown that neutrophils from Olfm4-deficient mice exhibited reduced H2O2-induced apoptosis compared with neutrophils from wild-type mice. We also demonstrated that neutrophils from Olfm4-deficient mice exhibited reduced H2O2-stimulated mitochondrial damage and membrane permeability, and as well as reduced caspase-3 and caspase-9 activity, compared with neutrophils from wild-type mice. Moreover, the cytoplasmic translocation of the proapoptotic mitochondrial proteins Omi/HtrA2 and Smac/DIABLO in response to H2O2was reduced in neutrophils from Olfm4-deficient mice compared with neutrophils from wild-type mice. Our study demonstrates that Olfm4 contributes to H2O2-induced NADPH oxidase activation and apoptosis in mouse neutrophils. Olfactomedin 4 might prove to be a potential target for future studies on inflammatory neutrophil biology and for inflammatory disease treatment.

Nitric oxide and penile erection in streptozotocin-diabetic rats

1999 ◽  
Vol 96 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Gil ARI ◽  
Yoram VARDI ◽  
John P. M. FINBERG
Keyword(s):  
Methyl Ester ◽  
Time Course ◽  
Insulin Treatment ◽  
Diabetic Rats ◽  
No Synthase ◽  
Sprague Dawley ◽  
Nerve Roots ◽  
Sprague Dawley Rats ◽  
Pithed Rats ◽  
Stimulation Of

The purpose of this investigation was to study the time course, response to insulin and characteristics of erectile dysfunction in streptozotocin (STZ)-diabetic Sprague–Dawley rats, and the function of the NO-generating system in these animals. Copulation-induced and reflex erection were quantified in conscious Sprague–Dawley rats at different times after injection of STZ. The corporal vasodilatation response to nerve stimulation was studied by measuring the rise in corporal pressure in pithed rats following electrical stimulation of sacral spinal nerve roots. The activity of NO synthase was determined in corporal tissue by measuring the generation of [3H]citrulline from [3H]arginine. Copulation-induced erection was inhibited at 1 and 2 months after STZ treatment, but this could be prevented by a short (2-week) pretreatment with insulin. Reflex erection was inhibited at 1, 4, 6 and 9 months after STZ; at 6 months, this inhibition was also reversible by insulin pretreatment. Following pithing, the basal corporal pressure was elevated in diabetic rats. At 4 months after STZ, this increase was normalized by a 2-week, but not by a 1-week, pretreatment with insulin; however, at 9 months after STZ, insulin pretreatment did not normalize corporal pressure. The increase in corporal pressure caused by stimulation of sacral nerve roots in pithed rats was enhanced in diabetic animals. This enhancement was also normalized at 4 months, but not at 9 months, by 2 weeks of insulin treatment. The inhibition of the stimulation-induced increase in corporal pressure by NG-nitro-L-arginine methyl ester (5 mg/kg) was less following 9 months of diabetes, although NO synthase activity was normal in cavernosal tissue following 6–8 months of diabetes. In conclusion, STZ-induced diabetes caused changes in the erectile system that were initially reversible by a short insulin treatment, but which with time (more than 6 months) became irreversible. NO synthase activity in cavernosal tissue was normal, but the response to NG-nitro-L-arginine methyl ester was inhibited in long-term diabetes (9 months).

Coronary endothelial dysfunction after cardiomyocyte-specific mineralocorticoid receptor overexpression

2011 ◽  
Vol 300 (6) ◽  
pp. H2035-H2043 ◽  
Author(s):  
Julie Favre ◽  
Ji Gao ◽  
An Di Zhang ◽  
Isabelle Remy-Jouet ◽  
Antoine Ouvrard-Pascaud ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
Coronary Arteries ◽  
Mineralocorticoid Receptor ◽  
Vascular Dysfunction ◽  
Reactive Oxygen ◽  
Oxidase Inhibitor ◽  
Oxygen Species ◽  
Coronary Endothelial Dysfunction

The deleterious effects of aldosterone excess demonstrated in cardiovascular diseases might be linked in part to coronary vascular dysfunction. However, whether such vascular dysfunction is a cause or a consequence of the changes occurring in the cardiomyocytes is unclear. Moreover, the possible link between mineralocorticoid receptor (MR)-mediated effects on the cardiomyocyte and the coronary arteries is unknown. Thus we used a mouse model with conditional, cardiomyocyte-specific overexpression of human MR (hMR) and observed the effects on endothelial function in isolated coronary segments. hMR overexpression decreased the nitric oxide (NO)-mediated relaxing responses to acetylcholine in coronary arteries (but not in peripheral arteries), and this was prevented by a 1-mo treatment either with an MR antagonist, vitamin E/vitamin C, or a NADPH oxidase inhibitor. hMR overexpression did not affect coronary endothelial NO synthase content nor its level of phosphorylation on serine 1177, but increased cardiac levels of reactive oxygen species, cardiac NADPH oxidase (NOX) activity, and expression of the NOX subunit gp91phox, which was limited to endothelial cells. Thus an increase in hMR activation, restricted to cardiomyocytes, is sufficient to induce a severe coronary endothelial dysfunction. We suggest a new paracrine mechanism by which cardiomyocytes trigger a NOX-dependent, reactive oxygen species-mediated coronary endothelial dysfunction.

scholarly journals HBP1 Repression of the p47phox Gene: Cell Cycle Regulation via the NADPH Oxidase

2004 ◽  
Vol 24 (7) ◽  
pp. 3011-3024 ◽  
Author(s):  
Stephen P. Berasi ◽  
Mei Xiu ◽  
Amy S. Yee ◽  
K. Eric Paulson
Keyword(s):  
Cell Cycle ◽  
Nadph Oxidase ◽  
Cell Cycle Regulation ◽  
Dominant Negative ◽  
Cellular Growth ◽  
Superoxide Production ◽  
Regulatory Subunit ◽  
Dominant Negative Mutant ◽  
Ros Generation ◽  
Cycle Regulation

ABSTRACT Several studies have linked the production of reactive oxygen species (ROS) by the NADPH oxidase to cellular growth control. In many cases, activation of the NADPH oxidase and subsequent ROS generation is required for growth factor signaling and mitogenesis in nonimmune cells. In this study, we demonstrate that the transcriptional repressor HBP1 (HMG box-containing protein 1) regulates the gene for the p47phox regulatory subunit of the NADPH oxidase. HBP1 represses growth regulatory genes (e.g., N-Myc, c-Myc, and cyclin D1) and is an inhibitor of G1 progression. The promoter of the p47phox gene contains six tandem high-affinity HBP1 DNA-binding elements at positions −1243 to −1318 bp from the transcriptional start site which were required for repression. Furthermore, HBP1 repressed the expression of the endogenous p47phox gene through sequence-specific binding. With HBP1 expression and the subsequent reduction in p47phox gene expression, intracellular superoxide production was correspondingly reduced. Using both the wild type and a dominant-negative mutant of HBP1, we demonstrated that the repression of superoxide production through the NADPH oxidase contributed to the observed cell cycle inhibition by HBP1. Together, these results indicate that HBP1 may contribute to the regulation of NADPH oxidase-dependent superoxide production through transcriptional repression of the p47phox gene. This study defines a transcriptional mechanism for regulating intracellular ROS levels and has implications in cell cycle regulation.

Homocysteine stimulates NADPH oxidase-mediated superoxide production leading to endothelial dysfunction in rats

2007 ◽  
Vol 85 (12) ◽  
pp. 1236-1247 ◽  
Author(s):  
Vathsala E.R. Edirimanne ◽  
Connie W.H. Woo ◽  
Yaw L. Siow ◽  
Grant N. Pierce ◽  
Jiu Y. Xie ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
Superoxide Anion ◽  
Vascular Wall ◽  
Oxidase Inhibitor ◽  
Vascular Cells ◽  
Superoxide Anion Production ◽  
Anion Production ◽  
Nadph Oxidase Activation ◽  
Endothelium Dependent Relaxation

Elevation of blood homocysteine (Hcy) levels (hyperhomocysteinemia) is a risk factor for cardiovascular disorders. We previously reported that oxidative stress contributed to Hcy-induced inflammatory response in vascular cells. In this study, we investigated whether NADPH oxidase was involved in Hcy-induced superoxide anion accumulation in the aorta, which leads to endothelial dysfunction during hyperhomocysteinemia. Hyperhomocysteinemia was induced in rats fed a high-methionine diet. NADPH oxidase activity and the levels of superoxide and peroxynitrite were markedly increased in aortas isolated from hyperhomocysteinemic rats. Expression of the NADPH oxidase subunit p22phox increased significantly in these aortas. Administration of an NADPH oxidase inhibitor (apocynin) not only attenuated aortic superoxide and peroxynitrite to control levels but also restored endothelium-dependent relaxation in the aortas of hyperhomocysteinemic rats. Transfection of human endothelial cells or vascular smooth muscle cells with p22phox siRNA to inhibit NADPH oxidase activation effectively abolished Hcy-induced superoxide anion production, thus indicating the direct involvement of NADPH oxidase in elevated superoxide generation in vascular cells. Taken together, these results suggest that Hcy-stimulated superoxide anion production in the vascular wall is mediated through the activation of NADPH oxidase, which leads to endothelial dysfunction during hyperhomocysteinemia.

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