scholarly journals Role of TNF-α-induced reactive oxygen species in endothelial dysfunction during reperfusion injury

2008 ◽  
Vol 295 (6) ◽  
pp. H2242-H2249 ◽  
Author(s):  
Xue Gao ◽  
Hanrui Zhang ◽  
Souad Belmadani ◽  
Junxi Wu ◽  
Xiangbin Xu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Dysfunction ◽  
Myocardial Ischemia ◽  
Endothelial Function ◽  
Xanthine Oxidase ◽  
Reactive Oxygen ◽  
Neutrophil Activation ◽  
Superoxide Production ◽  
Oxygen Species ◽  
Tnf Α

We hypothesized that neutralization of TNF-α at the time of reperfusion exerts a salubrious role on endothelial function and reduces the production of reactive oxygen species. We employed a mouse model of myocardial ischemia-reperfusion (I/R, 30 min/90 min) and administered TNF-α neutralizing antibodies at the time of reperfusion. I/R elevated TNF-α expression (mRNA and protein), whereas administration of anti-TNF-α before reperfusion attenuated TNF-α expression. We detected TNF-α expression in vascular smooth muscle cells, mast cells, and macrophages, but not in the endothelial cells. I/R induced endothelial dysfunction and superoxide production. Administration of anti-TNF-α at the onset of reperfusion partially restored nitric oxide-mediated coronary arteriolar dilation and reduced superoxide production. I/R increased the activity of NAD(P)H oxidase and of xanthine oxidase and enhanced the formation of nitrotyrosine residues in untreated mice compared with shams. Administration of anti-TNF-α before reperfusion blocked the increase in activity of these enzymes. Inhibition of xanthine oxidase (allopurinol) or NAD(P)H oxidase (apocynin) improved endothelium-dependent dilation and reduced superoxide production in isolated coronary arterioles following I/R. Interestingly, I/R enhanced superoxide generation and reduced endothelial function in neutropenic animals and in mice treated with a neutrophil NAD(P)H oxidase inhibitor, indicating that the effects of TNF-α are not through neutrophil activation. We conclude that myocardial ischemia initiates TNF-α expression, which induces vascular oxidative stress, independent of neutrophil activation, and leads to coronary endothelial dysfunction.

Rapid upregulation of endothelial P-selectin expression via reactive oxygen species generation

2002 ◽  
Vol 283 (5) ◽  
pp. H2054-H2061 ◽  
Author(s):  
Manabu Takano ◽  
Avedis Meneshian ◽  
Emran Sheikh ◽  
Yasuhiko Yamakawa ◽  
Kirsten Bass Wilkins ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Xanthine Oxidase ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Tnf Α ◽  
Early Peak ◽  
New Protein

Endothelial cell ICAM-1 upregulation in response to TNF-α is mediated in part by reactive oxygen species (ROS) generated by the endothelial membrane-associated NADPH oxidase and occurs maximally after 4 h as the synthesis of new protein is required. However, thrombin-stimulated P-selectin upregulation is bimodal, the first peak occurring within minutes. We hypothesize that this early peak, which results from the release of preformed P-selectin from within Weibel-Palade bodies, is mediated in part by ROS generated from the endothelial membrane-associated xanthine oxidase. We found that this rapid expression of P-selectin on the surface of endothelial cells was accompanied by qualitatively parallel increases in ROS generation. Both P-selectin expression and ROS generation were inhibited, dose dependently, by the exogenous administration of disparate cell-permeable antioxidants and also by the inhibition of either of the known membrane-associated ROS-generating enzymes NADPH oxidase or xanthine oxidase. This rapid, posttranslational cell signaling response, mediated by ROS generated not only by the classical NADPH oxidase but also by xanthine oxidase, may well represent an important physiological trigger of the microvascular inflammatory response.

scholarly journals Endothelial Dysfunction in Diabetes – Clasic Sources of Vascular Oxidative Stress (Nadph Oxidases, Enos Uncoupling and Xanthine Oxidase)

2013 ◽  
Vol 20 (2) ◽  
pp. 149-155
Author(s):  
Mircea Munteanu ◽  
Adrian Sturza ◽  
Adalbert Schiller ◽  
Romulus Timar
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Dysfunction ◽  
Xanthine Oxidase ◽  
Vascular Endothelium ◽  
Vascular Function ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Nadph Oxidases ◽  
Enos Uncoupling

Abstract Cardiovascular disease is the leading cause of disease / mortality worldwide. It is generally accepted that increased production of reactive oxygen species (ROS) has an important role in cardiovascular pathology, contributing to endothelial dysfunction and to the aggravation of atherosclerosis. Among all cardiovascular risk factors, diabetes mellitus is one of the most important. The worldwide prevalence of diabetes has increased rapidly even in developing countries, doubling the combined risk of cardiovascular events in patients with hypertension. In diabetes, increased reactive oxygen species (ROS) production leads to endothelial dysfunction, recognized by the presence of impaired vascular relaxation, increased vascular smooth muscle cells growth and hypertrophy, all together contributing to atherosclerotic plaque formation. On this basis, the vascular endothelium has emerged as a therapeutic target, with the aim to improve systemic metabolic state by improving vascular function. In this review we have focused on the most important sources of reactive oxygen species generated by vascular endothelium in diabetic patients (NADPH Oxidases, eNOS uncoupling, Xanthine oxidase). The importance of oxidative stress in mediating the vascular complications of diabetes is supported by studies showing that antioxidant therapy correct the vascular function in humans or in experimental models of diabetes. Therefore, understanding the physiological mechanisms involved in vascular disorders resulting from hyperglycemia is essential for the proper use of available therapeutic resources.

Clinical aspects of reactive oxygen and nitrogen species

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Endothelial Dysfunction ◽  
Vascular Tissue ◽  
Rapid Development ◽  
Reactive Oxygen ◽  
Clinical Aspects ◽  
No Production ◽  
Oxygen Species

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.

Altered composition of high-lipid diet may generate reactive oxygen species by disturbing the balance of antioxidant and free radicals

2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Arnab Banerjee ◽  
Debasmita Das ◽  
Rajarshi Paul ◽  
Sandipan Roy ◽  
Ankita Bhattacharjee ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Reactive Oxygen ◽  
Control Group ◽  
Preliminary Evaluation ◽  
Oxygen Species ◽  
High Lipid ◽  
Tnf Α ◽  
High Lipid Diet ◽  
Lipid Diet

AbstractBackgroundIn the present era, obesity is increasing rapidly, and high dietary intake of lipid could be a noteworthy risk factor for the occasion of obesity, as well as nonalcoholic fatty liver disease, which is the independent risk factor for type 2 diabetes and cardiovascular disease. For a long time, high-lipid diet (HLD) in “fast food” is turning into part of our everyday life. So, we were interested in fulfilling the paucity of studies by means of preliminary evaluation of these three alternative doses of HLD on a rat model and elucidating the possible mechanism of these effects and divulging the most alarming dose.MethodsThirty-two rats were taken, and of these, 24 were fed with HLD in three distinctive compositions of edible coconut oil and vanaspati ghee in a ratio of 2:3, 3:2 and 1:1 (n = 8), orally through gavage at a dose of 10 mL/kg body weight for a period of 28 days, whereas the other eight were selected to comprise the control group.ResultsAfter completion of the experiment, followed by analysis of data it was revealed that hyperlipidemia with increased liver and cardiac marker enzymes, are associated with hepatocellular injury and cardiac damage. The data also supported increased proinflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α). As oxidative stress parameter increased in both liver and heart, there is also an increased in TNF-α due to an increased expression of inducible nitric oxide (NO) synthase, which led to a high production of NO. Moreover, HLD treatment explicitly weakens reasonability of hepatocytes and cardiomyocytes conceivably through G0/G1 or S stage capture or perhaps by means of enlistment of sub-G0/G1 DNA fragmentation and a sign of apoptosis.ConclusionsBased on the outcomes, it tends to be inferred that consequences of the present examination uncovered HLD in combination of 2:3 applies most encouraging systemic damage by reactive oxygen species generation and hyperlipidemia and necroapoptosis of the liver and heart. Hence, outcome of this study may help to formulate health care strategy and warns about the food habit in universal population regarding the use of hydrogenated and saturated fats (vanaspati ghee) in diet.

scholarly journals Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Energy Demand ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
High Energy ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.

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