Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxidative stress has been implicated in the pathophysiology of myocardial failure. We tested the hypothesis that inhibition of endogenous antioxidant enzymes can regulate the phenotype of cardiac myocytes. Neonatal rat ventricular myocytes in vitro were exposed to diethyldithiocarbamic acid (DDC), an inhibitor of cytosolic (Cu, Zn) and extracellular superoxide dismutase (SOD). DDC inhibited SOD activity and increased intracellular superoxide in a concentration-dependent manner. A low concentration (1 micromol/L) of DDC stimulated myocyte growth, as demonstrated by increases in protein synthesis, cellular protein, prepro-atrial natriuretic peptide, and c-fos mRNAs and decreased sarcoplasmic reticulum Ca(2+)ATPase mRNA. These actions were all inhibited by the superoxide scavenger Tiron (4,5-dihydroxy-1,3-benzene disulfonic acid). Higher concentrations of DDC (100 micromol/L) stimulated myocyte apoptosis, as evidenced by DNA laddering, characteristic nuclear morphology, in situ terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL), and increased bax mRNA expression. DDC-stimulated apoptosis was inhibited by the SOD/catalase mimetic EUK-8. The growth and apoptotic effects of DDC were mimicked by superoxide generation with xanthine plus xanthine oxidase. Thus, increased intracellular superoxide resulting from inhibition of SOD causes activation of a growth program and apoptosis in cardiac myocytes. These findings support a role for oxidative stress in the pathogenesis of myocardial remodeling and failure.
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PMID:Inhibition of copper-zinc superoxide dismutase induces cell growth, hypertrophic phenotype, and apoptosis in neonatal rat cardiac myocytes in vitro. 1041 96

Endothelial dysfunction (ED) has been documented in patients with both coronary artery disease (CAD) and chronic heart failure (CHF)-being responsible for exercise-induced myocardial ischemia in the former and increased afterload in the latter. In the last two decades exercise training has assumed a major role in both cardiovascular disorders. In CAD exercise training has established positive effects on myocardial perfusion. Recently, exercise training has been shown to attenuate paradoxical vasoconstriction in CAD. The improved ED after training explains the improvement of myocardial perfusion in the absence of changes in baseline coronary artery diameter. Since ED has been identified as a predictor of coronary events exercise may contribute to long-term reductions of cardiovascular mortality. In CHF the increased peripheral vascular resistance - especially during exercise - is more important. ED contributes to the peripheral vasoconstriction. Training programs have shown to improve ED in CHF. A long-term study of hemodynamic effects of training in CHF revealed a significant reduction of total peripheral resistance (TPR) that after 6 months with a concomitant increase in stroke volume. In a subgroup analysis a significant correlation between changes in TPR and changes in peripheral ED was observed. Cell culture and animal experiments suggest that shear stress increases the endothelial L-arginine uptake, enhances NO synthase activity and expression, and upregulates the production of extracellular superoxide dismutase, which prevents premature NO breakdown. All these molecular effects converge on a reduction of myocardial ischemic events in CAD and a decrease of afterload in CHF.
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PMID:Exercise training and endothelial dysfunction in coronary artery disease and chronic heart failure. From molecular biology to clinical benefits. 1203 63

We recently showed that treatment with the Cu(II)-selective chelator, trientine, alleviates heart failure in diabetic rats, improves left ventricular hypertrophy in humans with type 2 diabetes, and increases urinary Cu excretion in both diabetic rats and humans compared with nondiabetic control subjects. In this study, we characterized the homeostasis of Cu and eight other nutritionally essential elements in diabetes under fully residential conditions in male subjects with type 2 diabetes and age-matched control subjects. We then probed elemental balance with oral trientine in a parallel-group, placebo-controlled study in these subjects. Before treatment, there were no detectable between-group differences in the balance of any element, although urinary output of several elements was greater in diabetic subjects. Mean extracellular superoxide dismutase (EC-SOD) activity was elevated in diabetic subjects, and its activity correlated strongly with the interaction between [Cu]serum and HbA1c. Trientine caused the Cu balance to become negative in diabetic subjects through elevated urinary Cu losses and suppressed elevated EC-SOD. Basal urinary Cu predicted urinary Cu losses during treatment, which caused extraction of systemic Cu(II). We suggest that cardiovascular complications in diabetes might be better controlled by therapeutic strategies that focus on lowering plasma glucose and loosely bound systemic Cu(II).
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PMID:Demonstration of a hyperglycemia-driven pathogenic abnormality of copper homeostasis in diabetes and its reversibility by selective chelation: quantitative comparisons between the biology of copper and eight other nutritionally essential elements in normal and diabetic individuals. 1585 35

Oxidative stress is associated with endothelial dysfunction in heart failure. The goals of this study were to determine whether 1) gene transfer of extracellular superoxide dismutase (ecSOD) reduces levels of superoxide and improves endothelial function in the aorta and mesenteric artery in rats with heart failure, and 2) the heparin-binding domain (HBD) of ecSOD, by which ecSOD binds to cells, is required for protective effects of ecSOD. Seven weeks after coronary ligation, in rats with heart failure and sham-operated rats, we injected adenoviral vectors intravenously that express ecSOD, ecSOD with deletion of the HBD (ecSODDeltaHBD), or a control vector. Four days after injection of viruses, responses to acetylcholine, ADP, and sodium nitroprusside were examined in rings of the aorta and mesenteric artery. ecSOD bound to endothelium and increased SOD activity in the aorta after gene transfer of ecSOD, not ecSODDeltaHBD. Gene transfer of ecSOD, but not ecSODDeltaHBD, reduced levels of superoxide and improved relaxation to acetylcholine and ADP in the aorta and mesenteric artery from rats with heart failure. Improvement of relaxation to acetylcholine in the mesenteric artery from rats with heart failure after gene transfer of ecSOD was mediated in part by hydrogen peroxide. The major finding of this study is that the HBD of ecSOD is necessary for protection against endothelial dysfunction in rats with heart failure. We speculate that a common gene variant in the HBD of ecSOD, which is a risk factor for ischemic heart disease, may be a risk factor for vascular maladaptation and endothelial dysfunction in heart failure.
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PMID:Gene transfer of extracellular superoxide dismutase improves endothelial function in rats with heart failure. 1601 12

A common gene variant of human extracellular superoxide dismutase (ecSOD), in approximately 5% of humans, is associated with increased risk of ischemic heart disease. The purpose of this study was to examine vascular effects of ecSOD with effects of the ecSOD variant (ecSOD(R213G)) in rats with heart failure. Seven weeks after coronary artery ligation, we studied rats with heart failure and sham-operated rats. Adenoviral vectors expressing human ecSOD, ecSOD(R213G), or a control virus were injected intravenously. In the aorta from rats with heart failure, responses to acetylcholine (69 +/- 4% relaxation, means +/- SE) and basal levels of nitric oxide (NO) (vasoconstrictor responses to a NO synthase inhibitor) were greatly impaired, and levels of superoxide and peroxynitrite were increased. Gene transfer of ecSOD restored responses to acetylcholine (92 +/- 2% relaxation) and basal levels of NO to normal and reduced levels of superoxide [from 2.3 +/- 0.2 to 0.9 +/- 0.2 relative light units per second per millimeter squared (RLU x s(-1) x mm(-2))] and peroxynitrite (from 2.4 +/- 0.2 to 0.9 +/- 0.1 RLU x s(-1) x mm(-2)) in the aorta from rats with heart failure. Gene transfer of ecSOD(R213G) produced little or no improvement. Responses to nitroprusside were not different among the groups. Expression of endogenous mRNA for SODs (CuZnSOD, MnSOD, and ecSOD) and endothelial NOS in the aorta was not different among the groups. In contrast to ecSOD, gene transfer of ecSOD(R213G) in rats with heart failure has minimal beneficial effect on oxidative stress, endothelial function, or basal bioavailability of NO. We speculate that greatly diminished efficacy of ecSOD(R213G) in protection against oxidative stress and endothelial dysfunction may contribute to increased risk of cardiovascular disease in humans with ecSOD(R213G).
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PMID:Vascular effects of a common gene variant of extracellular superoxide dismutase in heart failure. 1684 Jul 38

Increased serum uric acid has been identified as an independent risk factor for cardiovascular disease. However, because of its antioxidant capacity, uric acid may play a beneficial role in endothelial function. This paradoxical relationship between uric acid and endothelial function in chronic heart failure patients remains poorly understood. Thirty-eight chronic heart failure patients (New York Heart Association functional class II-III, mean age 58+/-10 years and mean left ventricular ejection fraction 25+/-8%) and twelve age-and-sex-matched healthy controls were studied. Chronic heart failure patients showed higher uric acid levels (7.3+/-2.3 mg/dL vs. 6.1+/-0.2 mg/dL, p<0.05) and lower extracellular superoxide dismutase activity (136+/-36 U ml(-1) min(-1) vs. 203+/-61 U ml(-1) min(-1), p<0.01) and endothelium-dependent vasodilatation (4.0+/-1.6% v. 9.1+/-3.0%, p<0.01) when compared with control subjects. In chronic heart failure patients, correlations between both uric acid levels and extracellular superoxide dismutase activity (r=0.45; p<0.01), and uric acid and endothelium-dependent vasodilatation (r=0.35; p=0.03) were detected. These correlations were not observed in healthy individuals, suggesting a positive effect of uric acid on endothelial function partially mediated by modulation of extracellular superoxide dismutase activity in chronic heart failure.
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PMID:Serum uric acid correlates with extracellular superoxide dismutase activity in patients with chronic heart failure. 1901 82

Reactive oxygen species seem to play an important role in vascular homeostasis. In conditions of high oxidative stress, such as chronic heart failure and multiple coronary risk factors, the rate of inactivation of nitric oxide to peroxynitrite by superoxide anions may be reduced by CoQ10, which can also protect against nitrosative damage. CoQ10 may also influence vascular function indirectly via inhibition of oxidative damage to LDL. Patients with lower levels of extracellular superoxide dismutase (ecSOD) demonstrate greater improvements than patients with normal ec-SOD levels, suggesting that the higher the oxidative stress the greater the improvement in the endothelium-dependent relaxation after the administration of a compound with antioxidant properties like CoQ10. Future studies are needed to inquire whether these effects may translate into benefits in clinical practice.
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PMID:Oxidative stress, endothelial function and coenzyme Q10. 1909 8