P-2 NAD(P)H oxidase inhibitor improves endothelial dysfunction in streptozotocin induced diabetes in rats

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.

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Coronary endothelial dysfunction after cardiomyocyte-specific mineralocorticoid receptor overexpression

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00552.2010 ◽

2011 ◽

Vol 300 (6) ◽

pp. H2035-H2043 ◽

Cited By ~ 35

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.

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

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y07-112 ◽

2007 ◽

Vol 85 (12) ◽

pp. 1236-1247 ◽

Cited By ~ 59

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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Adventitial application of the NADPH oxidase inhibitor apocynin in vivo reduces neointima formation and endothelial dysfunction in rabbits

Cardiovascular Research ◽

10.1016/j.cardiores.2007.06.005 ◽

2007 ◽

Vol 75 (4) ◽

pp. 710-718 ◽

Cited By ~ 29

Author(s):

E CHAN ◽

S DATLA ◽

R DILLEY ◽

H HICKEY ◽

G DRUMMOND ◽

...

Keyword(s):

Endothelial Dysfunction ◽

Nadph Oxidase ◽

Oxidase Inhibitor ◽

Neointima Formation ◽

Nadph Oxidase Inhibitor

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Role of oxidative stress in multiparity-induced endothelial dysfunction

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.87.2008 ◽

2008 ◽

Vol 295 (4) ◽

pp. H1736-H1742 ◽

Cited By ~ 20

Author(s):

Huda E. Tawfik ◽

Jonathan Cena ◽

Richard Schulz ◽

Susan Kaufman

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Endothelial Dysfunction ◽

Coronary Arteries ◽

Vascular Tissue ◽

Fold Increase ◽

Oxidase Inhibitor ◽

Maximal Response ◽

Protein Levels ◽

Increased Risk

Multiparity is associated with increased risk of cardiovascular disease. We tested whether multiparity induces oxidative stress in rat vascular tissue. Coronary arteries and thoracic aorta were isolated from multiparous and age-matched virgin rats. Relaxation to ACh and sodium nitroprusside (SNP) was measured by wire myography. We also tested the effect of the superoxide dismutase mimetic MnTE2PyP (30 μM), the NADPH oxidase inhibitor apocynin (10 μM), and the peroxynitrite scavenger FeTPPs (10 μM) on ACh-mediated relaxation in coronary arteries. Vascular superoxide anion was measured using the luminol derivative L-012 and nitric oxide (NO) generation by the Griess reaction. Multiparity reduced maximal response and sensitivity to ACh in coronary arteries [maximal relaxation (Emax): multiparous 49 ± 3% vs. virgins 95% ± 3%; EC50: multiparous 135 ± 1 nM vs. virgins 60 ± 1 nM], and in aortic rings (Emax: multiparous 38 ± 3% vs. virgins 79 ± 4%; EC50: multiparous 160 ± 2 nM vs. virgins 90 ± 3 nM). Coronary arteries from the two groups relaxed similarly to SNP. Superoxide anions formation was significantly higher in both coronary arteries (2.8-fold increase) and aorta (4.1-fold increase) from multiparous rats compared with virgins. In multiparous rats, incubation with MnTE2PyP, apocynin, and FeTPPs improved maximal relaxation to ACh (MnTE2PyP: 74 ± 5%; vehicle: 41 ± 5%; apocynin: 73 ± 3% vs. vehicle: 41 ± 3%; FeTPPs: 72 ± 3% vs. vehicle: 46 ± 3%) and increased sensitivity (EC50: MnTE2PyP: 61 ± 0.5 nM vs. vehicle: 91 ± 1 nM; apocynin: 45 ± 3 nM vs. vehicle: 91 ± 6 nM; FeTPP: 131 ± 2 nM vs. vehicle: 185 ± 1 nM). Multiparity also reduced total nitrate/nitrite levels (multiparous: 2.5 ± 2 μmol/mg protein vs. virgins: 7 ± 1 μmol/mg protein) and endothelial nitric oxide synthase protein levels (multiparous: 0.53 ± 0.1 protein/actin vs. virgins: 1.0 ± 0.14 protein/actin). These data suggest that multiparity induces endothelial dysfunction through decreased NO bioavailability and increased reactive oxygen species formation.

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Sulodexide improves endothelial dysfunction in streptozotocin-induced diabetes in rats

Physiological Research ◽

10.33549/physiolres.931506 ◽

2008 ◽

pp. 491-494

Author(s):

V Kristová ◽

S Líšková ◽

R Sotníková ◽

R Vojtko ◽

A Kurtanský

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

Rat Aorta ◽

Cardiovascular Complications ◽

Mesenteric Arteries ◽

Circulating Endothelial Cells ◽

Protective Effects ◽

Pharmacological Agents ◽

Postprandial Plasma Glucose ◽

Streptozotocin Induced Diabetes

Diabetes mellitus is associated with many complications including retinopathy, nephropathy, neuropathy and angiopathy. Increased cardiovascular risk is accompanied with diabetes-induced endothelial dysfunction. Pharmacological agents with endothelium-protective effects may decrease cardiovascular complications. In present study sulodexide (glycosaminoglycans composed from heparin-like and dermatan fractions) was chosen to evaluate its protective properties on endothelial dysfunction in diabetes. Effect of sulodexide treatment (SLX, 100 UI/kg/day, i.p.) in 5 and 10 weeks lasting streptozotocin-induced diabetes (30 mg/kg/day, i.p. administered for three consecutive days) was investigated. Animals were divided into four groups: control (injected with saline solution), control-treated with sulodexide (SLX), diabetic (DM) and diabetic-treated with sulodexide (DM+SLX). The pre-prandial and postprandial plasma glucose levels, number of circulating endothelial cells (EC) and acetylcholine-induced relaxation of isolated aorta and mesenteric artery were evaluated. Streptozotocin elicited hyperglycemia irrespective of SLX treatment. Streptozotocin-induced diabetes enhanced the number of circulating endothelial cells compared to controls. SLX treatment decreased the number of EC in 10-week diabetes. Acetylcholine-induced relaxation of mesenteric arteries was significantly impaired in 5 and 10-week diabetes. SLX administration improved relaxation to acetylcholine in 5 and 10- week diabetes. Diabetes impaired acetylcholine-induced relaxation of rat aorta irrespective of SLX treatment. Our results demonstrate that SLX treatment lowers the number of circulating endothelial cells and improves endothelium-dependent relaxation in small arteries. These findings suggest endothelium-protective effect of sulodexide in streptozotocin-induced diabetes.

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Impaired flow-induced dilation of coronary arterioles of dogs fed a low-salt diet: roles of ANG II, PKC, and NAD(P)H oxidase

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01250.2009 ◽

2010 ◽

Vol 299 (5) ◽

pp. H1476-H1483 ◽

Cited By ~ 16

Author(s):

An Huang ◽

Changdong Yan ◽

Nobuhiro Suematsu ◽

Azita Cuevas ◽

Yang-Ming Yang ◽

...

Keyword(s):

Endothelial Dysfunction ◽

Cardiovascular Effects ◽

Oxidase Inhibitor ◽

Ang Ii ◽

Salt Diet ◽

Kinase C ◽

Low Salt ◽

Plasma Angiotensin ◽

Coronary Arterioles

Low-salt (LS) diet has been considered to be beneficial in the prevention and treatment of hypertension; however, it also increases plasma angiotensin (ANG) II and may cause adverse cardiovascular effects, such as endothelial dysfunction. We assessed endothelial function of coronary arterioles and vascular superoxide production, as a function of LS diet. Dogs were fed with LS (0.05% NaCl) or a normal-salt (NS, 0.65% NaCl) diet for 2 wk. There were threefold increases in plasma ANG II, associated with a 60% reduction in flow-induced dilation (FID) in coronary arterioles of LS compared with NS dogs. In vessels of NS dogs, FID was primarily mediated by nitric oxide (NO), as indicated by an eliminated FID by Nω-nitro-l-arginine methyl ester (l-NAME). In vessels of LS dogs, however, FID was eliminated. Administration of apocynin, a NAD(P)H oxidase inhibitor, partially restored FID and additional l-NAME eliminated FID. Generation of superoxide, measured with dihydroethidium, was significantly greater in vessels of LS than in NS dogs, which was further increased in response to ANG II or phorbol 12,13-dibutyrate, an agonist of protein kinase C (PKC). The enhanced superoxide was normalized by apocynin, losartan (a blocker of angiotensin type 1 receptor), and chelerythrine chloride (an antagonist of PKC). Western blotting indicated an upregulation of gp91phox and p47phox, associated with increased expression of phosphorylated PKC in vessels of LS dogs. In separate experiments, dogs were fed simultaneously with LS and losartan (LS + Losa) for 2 wk. There was a significant increase in plasma ANG II in LS + Losa dogs, which, however, was associated with normal FID and gp91phox expression in coronary arterioles. In conclusion, LS led to endothelial dysfunction, as indicated by an impaired flow-induced dilation caused by decreasing NO bioavailibility, a response that involves angiotensin-induced activation of PKC that, in turn, activates vascular NAD(P)H oxidase to produce superoxide.

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Human microvascular dysfunction and apoptotic injury induced by AL amyloidosis light chain proteins

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00503.2011 ◽

2011 ◽

Vol 301 (6) ◽

pp. H2305-H2312 ◽

Cited By ~ 48

Author(s):

Raymond Q. Migrino ◽

Seth Truran ◽

David D. Gutterman ◽

Daniel A. Franco ◽

Megan Bright ◽

...

Keyword(s):

Endothelial Cells ◽

Coronary Artery ◽

Endothelial Dysfunction ◽

Light Chain ◽

Annexin V ◽

Microvascular Dysfunction ◽

Oxidase Inhibitor ◽

Al Amyloidosis ◽

Human Coronary Artery ◽

Coronary Arterioles

Light chain amyloidosis (AL) involves overproduction of amyloidogenic light chain proteins (LC) leading to heart failure, yet the mechanisms underlying tissue toxicity remain unknown. We hypothesized that LC induces endothelial dysfunction in non-AL human microvasculature and apoptotic injury in human coronary artery endothelial cells (HCAECs). Adipose arterioles ( n = 34, 50 ± 3 yr) and atrial coronary arterioles ( n = 19, 68 ± 2 yr) from non-AL subjects were cannulated. Adipose arteriole dilator responses to acetylcholine/papaverine were measured at baseline and 1 h exposure to LC (20 μg/ml) from biopsy-proven AL subjects (57 ± 11 yr) without and with antioxidant cotreatment. Coronary arteriole dilation to bradykinin/papaverine was measured post-LC exposure. HCAECs were exposed to 1 or 24 h of LC. LC reduced dilation to acetylcholine (10−4M: 41.6 ± 7 vs. 85.8 ± 2.2% control, P < 0.001) and papaverine (81.4 ± 4.6 vs. 94.8 ± 1.3% control, P < 0.01) in adipose arterioles and to bradykinin (10−6M: 68.6 ± 6.2 vs. 90.9 ± 1.6% control, P < 0.001) but not papaverine in coronary arterioles. There was an increase in superoxide and peroxynitrite in arterioles treated with LC. Adipose arteriole dilation was restored by cotreatment with polyethylene glycol-superoxide dismutase and tetrahydrobiopterin but only partially restored by mitoquinone (mitochondria-targeted antioxidant) and gp91ds-tat (NADPH oxidase inhibitor). HCAECs exposed to LC showed reduced NO and increased superoxide, peroxynitrite, annexin-V, and propidium iodide compared with control. Brief exposure to physiological amounts of LC induced endothelial dysfunction in human adipose and coronary arterioles and increased apoptotic injury in coronary artery endothelial cells likely as a result of oxidative stress, reduced NO bioavailability, and peroxynitrite production. Microvascular dysfunction and injury is a novel mechanism underlying AL pathobiology and is a potential target for therapy.

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