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)

Skeletal muscle disuse with space-flight and ground-based models (e.g., hindlimb unloading) results in dramatic skeletal muscle atrophy and weakness. Pathological conditions that cause muscle wasting (i.e., heart failure, muscular dystrophy, sepsis, COPD, cancer) are characterized by elevated "oxidative stress," where antioxidant defenses are overwhelmed by oxidant production. However, the existence, cellular mechanisms, and ramifications of oxidative stress in skeletal muscle subjected to hindlimb unloading are poorly understood. Thus we examined the effects of hindlimb unloading on hindlimb muscle antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione peroxidase), nonenzymatic antioxidant scavenging capacity (ASC), total hydroperoxides, and dichlorohydrofluorescein diacetate (DCFH-DA) oxidation, a direct indicator of oxidative stress. Twelve 6 month old Sprague Dawley rats were divided into two groups: 28 d of hindlimb unloading (n = 6) and controls (n = 6). Hindlimb unloading resulted in a small decrease in Mn-superoxide dismutase activity (10.1%) in the soleus muscle, while Cu,Zn-superoxide dismutase increased 71.2%. In contrast, catalase and glutathione peroxidase, antioxidant enzymes that remove hydroperoxides, were significantly reduced in the soleus with hindlimb unloading by 54.5 and 16.1%, respectively. Hindlimb unloading also significantly reduced ASC. Hindlimb unloading increased soleus lipid hydroperoxide levels by 21.6% and hindlimb muscle DCFH-DA oxidation by 162.1%. These results indicate that hindlimb unloading results in a disruption of antioxidant status, elevation of hydroperoxides, and an increase in oxidative stress.
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PMID:Hindlimb unloading increases oxidative stress and disrupts antioxidant capacity in skeletal muscle. 1282 51

In the left ventricle subjected to pressure overload activity, the antioxidant enzymes increased at the hyperfunctional stage. During the transition to heart failure, these enzymes are down-regulated, oxidative stress increases, and apoptosis progresses. Maladaptative activation of the antioxidant enzymes at an early stage may contribute to the intrinsic vulnerability of right ventricle to pressure overload. The authors studied changes in expression and activity of the enzymes manganese and copper-zinc superoxide dismutases, glutathione peroxidase, and catalase in the right ventricle of rat following induction of pulmonary hypertension by injection of monocrotaline. Increase in the manganese superoxide dismutase was delayed to the late failing stage, activity of glutathione peroxidase was depressed throughout, and only catalase was activated at the early stage before returning to control levels. This inability to activate antioxidant enzymes may contribute to the deleterious consequences of pressure overload on right ventricle systolic function.
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PMID:The activation pattern of the antioxidant enzymes in the right ventricle of rat in response to pressure overload is of heart failure type. 1450 27

Increased oxidative stress and reduction in antioxidant enzymes have been suggested to be involved in the pathophysiology of congestive heart failure subsequent to myocardial infarction (MI). The objective of the present study was to characterize changes in the mRNA abundance and protein levels for the enzymatic antioxidants, superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase during the sequelae of congestive heart failure in rats. MI was produced by the ligation of the left coronary artery and hearts from controls and 1, 4 and 16 week PMI groups were analyzed. Losartan treatment (2 mg/ml in drinking water, daily) was started at 4 weeks and continued for 12 weeks. The mRNA levels for SOD were reduced by about 40% at 1-week PMI, were near to the control levels at 4-week PMI and at 16 weeks PMI, the levels were reduced by about 73% below the controls. GSHPx mRNA levels remained unchanged at all time points. The mRNA levels for catalase remained unchanged at 1 and 4 weeks PMI and were significantly reduced by about 44% at 16 weeks PMI as compared to the controls. The protein levels for MnSOD, CuZnSOD, GSHPx at 1 and 16 weeks remained unchanged in treated and untreated PMI groups. However, the protein levels for catalase was significantly increased in the control and PMI groups treated with Losartan. It is concluded that changes in the SOD and catalase activities during severe heart failure correlated with changes in mRNA for these enzymes. The precise mechanism/s for the improvement in antioxidant reserve and protein levels after Losartan treatment is/are unclear at this time.
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PMID:Antioxidant enzyme gene expression in congestive heart failure following myocardial infarction. 1457 98

Primary amyloidosis is a systemic disorder characterized by the clonal production and tissue deposition of immunoglobulin light chain (LC) proteins. Congestive heart failure remains the greatest cause of death in primary amyloidosis, due to the development of a rapidly progressive amyloid cardiomyopathy. Amyloid cardiomyopathy is largely unresponsive to current heart failure therapies, and is associated with a median survival of less than 6 months and a 5-year survival of less than 10%. The mechanisms underlying this disorder, however, remain unknown. In this report, we demonstrate that physiological levels of human amyloid LC proteins, isolated from patients with amyloid cardiomyopathy (cardiac-LC), specifically alter cellular redox state in isolated cardiomyocytes, marked by an increase in intracellular reactive oxygen species and upregulation of the redox-sensitive protein, heme oxygenase-1. In contrast, vehicle or control LC proteins isolated from patients without cardiac involvement did not alter cardiomyocyte redox status. Oxidant stress imposed by cardiac-LC proteins further resulted in direct impairment of cardiomyocyte contractility and relaxation, associated with alterations in intracellular calcium handling. Cardiomyocyte dysfunction induced by cardiac-LC proteins was independent of neurohormonal stimulants, vascular factors, or extracellular fibril deposition, and was prevented through treatment with a superoxide dismutase/catalase mimetic. This study suggests that cardiac dysfunction in amyloid cardiomyopathy is directly mediated by LC protein-induced cardiomyocyte oxidant stress and alterations in cellular redox status, independent of fibril deposition. Antioxidant therapies or treatment strategies aimed at eliminating circulating LC proteins may therefore be beneficial in the treatment of this fatal disease.
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PMID:Human amyloidogenic light chains directly impair cardiomyocyte function through an increase in cellular oxidant stress. 1504 25

Cardiac norepinephrine (NE) uptake is reduced in cardiomyopathy. This change is associated with a decrease of NE transporter (NET) receptor and can be reproduced in PC12 cells by extracellular NE. To study whether this effect of NE is mediated via impaired glycosylation and trafficking of NET in the endoplasmic reticulum (ER), we measured the distribution of glycosylated 80-kDa NET and unglycosylated 46-kDa NET in the membrane and cytosolic fractions of PC12 cells. We found that NE decreased glycosylated NET in both membrane and cytosolic fractions and increased cytosolic unglycosylated NET protein. Similar results were produced by tunicamycin and thapsigargin, two agents that induce ER stress by inhibiting N-glycosylation of membrane proteins and disrupting calcium homeostasis, respectively. Also, like the ER stressors, NE not only increased phosphorylation of both the alpha-subunit of eukaryotic initiation factor-2 and its upstream RNA-dependent protein kinase-like ER kinase over 12 h of treatment but also increased ER chaperone molecule glucose-regulated protein 78 and the nuclear transcription factor C/EBP homologous protein. Antioxidants superoxide dismutase and catalase prevented the downregulation of NET proteins and induction of ER stress signals produced by NE but not by tunicamycin or thapsigargin. The results indicate that the downregulation of membrane NET by NE is mediated by decreased N-glycosylation of NET proteins secondary to induction of ER stress pathways by NE-derived oxidative metabolites. Interventions involving the ER stress pathways may provide novel therapeutic strategies for the treatment of sympathetic dysfunction in heart failure.
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PMID:Norepinephrine induces endoplasmic reticulum stress and downregulation of norepinephrine transporter density in PC12 cells via oxidative stress. 1562 88

Refracterin therapy of patients with chronic heart failure caused by coronary heart disease and postinfarction cardiosclerosis markedly promoted improvement in the pulmonary and systemic circulation in comparison with patients receiving traditional therapy. The mean functional class of chronic cardiac failure decreased by 43% under the effect of refracterin vs. 27% decrease in the group receiving traditional therapy. After 1-month refracterin course the end-systolic and end-diastolic sizes of the left ventricle decreased by 12 and 7%, respectively, ejection fraction increased by 7.2% in comparison with the initial level, total oxidant activity and MDA content in the plasma decreased significantly, while total antioxidant activity, catalase and SOD activities, cytochrome C, NADH, and NADPH levels increased. The prooxidant-antioxidant system was shifted towards antioxidants, which attests to activation of the defense and adaptive mechanisms after administration of refracterin, which is especially important in elderly patients with initially decreased reserve potentialities of the antioxidant defense system.
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PMID:Efficiency and mechanisms of the antioxidant effect of standard therapy and refracterin in the treatment of chronic heart failure in elderly patients with postinfarction cardiosclerosis. 1566 59

Cardiomyocyte death resulting from apoptosis has been implicated in the evolution of heart failure. In this review, we focus on the concept that the cardiotoxicity of excessive sympathetic nervous system activity observed in heart failure is in part due to myocytes death by apoptosis. In vitro, high doses of norepinephrine induce adult cardiomyocyte apoptosis via 3-adrenergic receptor-coupled signaling pathways (PKA and Ca2+ entry-dependent mechanisms). beta1-and beta2-AR co-exist in the cardiac cell. beta1-AR stimulation is pro-apoptotic, whereas beta2-AR stimulation is anti-apoptotic, mediating its protective effect via coupling to Gi. These in vitro observations have been confirmed in transgenic mice: cardiac beta1-AR overexpression increases apoptosis and leads to heart failure, whereas cardiac beta2-AR overexpression has no deleterious effects. beta-AR stimulation activates p38 kinases and JNK (via the small GTP protein Rac1); and exert anti- and pro-apoptotic effects, respectively. Other studies suggest that beta1-AR-stimulated apoptosis is dependent on Ca2+ -activated calmodulin kinase II and that the anti-apoptotic effect of beta2-AR is mediated via Akt-coupled pathways. beta-AR-stimulated apoptosis involves the mitochondrial pathway. Inhibition of mitochondrial permeability transition pore opening or caspase activation decreases beta-AR-stimulated apoptosis. Reactive oxygen species production is also involved in this process since superoxide dismutase/catalase-mimetics or catalase overexpression prevent beta-AR-stimulated apoptosis. In vivo, it has been shown that beta-AR blockers such as metoprolol and carvedilol have beneficial effects in animal models of chronic heart failure, associated with reduced apoptosis and improved cardiac systolic function. Understanding the mechanisms involved in the control of myocyte loss by the beta-adrenergic system will have direct clinical implications by improving the treatment of heart failure.
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PMID:The control of cardiomyocyte apoptosis via the beta-adrenergic signaling pathways. 1581 27

Diabetic patients manifest an increased incidence of heart failure (HF) after myocardial infarction (MI), which presages an increase in morbidity and mortality. Although oxidative stress has been implicated in diabetic complications, oxidative stress status associated with comorbid conditions that frequently accompany diabetes remains unknown. Therefore, we examined antioxidants and oxidative stress in the surviving myocardium in relation to ventricular function during diabetic HF following MI. MI was produced in diabetic and nondiabetic rats by ligation of the left coronary artery. At 4 weeks post-MI, LV systolic pressure (LVSP), rate of pressure rise (+dP/dt), and rate of pressure decay (-dP/dt) were depressed to a significantly greater extent in diabetic compared to nondiabetic MI animals. Higher levels of myocardial 8-isoprostane (8-iso PGF(2alpha)), oxidized glutathione (GSSG), as well as greater upregulation of superoxide dismutase (SOD) and catalase (CAT) protein expression paralleled by increases in enzymatic activity was observed in the diabetic MI animals, indicating higher oxidative stress. These data demonstrate a greater derangement of oxidative stress in the surviving tissues of diabetic post-MI rat hearts concomitant with an increased functional severity of HF, and suggest that chronic antioxidant therapy may be useful for the prophylaxis of subsequent HF after MI associated with diabetes.
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PMID:Greater propensity of diabetic myocardium for oxidative stress after myocardial infarction is associated with the development of heart failure. 1612 23

Chronic elevation of circulating ANG II is associated with cardiac remodeling in patients with hypertension and heart failure. The underlying mechanisms, however, are not completely defined. Herein, we studied ANG II-induced molecular and cellular events in the rat heart as well as their links to the redox state. We also addressed the potential contribution of aldosterone (ALDO) on ANG II-induced cardiac remodeling. In ANG II-treated rats, and compared with controls, we found: 1) the expression of proinflammatory/profibrogenic mediators was significantly increased in the perivascular space and at the sites of microscopic injury in both ventricles; 2) macrophages and myofibroblasts were primary repairing cells at these sites, together with increased fibrillar collagen volume; 3) apoptotic macrophages and myofibroblasts were evident at the same sites; 4) NADPH oxidase (gp91phox) was significantly enhanced at these regions and primarily expressed by macrophages, whereas superoxide dismutase and catalase levels remained unchanged; 5) plasma 8-isoprostane levels were significantly increased; and 6) blood pressure was significantly elevated. Losartan treatment completely prevented cardiac oxidative stress as well as molecular/cellular responses and normalized blood pressure. Spironolactone treatment partially suppressed the cardiac inflammatory/fibrogenic responses and redox state. Thus chronic elevation of circulating ANG II is accompanied by a proinflammatory/profibrogenic phenotype involving vascular and myocardial remodeling in both ventricles. Enhanced reactive oxygen species production at these sites and increased plasma 8-isoprostane indicate the involvement of oxidative stress in ANG II-induced cardiac injury. ALDO contributes, in part, to ANG II-induced cardiac molecular and cellular responses.
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PMID:ANG II-induced cardiac molecular and cellular events: role of aldosterone. 1648 2

Reactive oxygen species (ROS) contribute to the pathogenesis of cardiovascular diseases including hypertension, atherosclerosis, cardiac hypertrophy, heart failure and diabetes mellitus. Oxidative stress is resulted from excessive generation of ROS that outstrips the antioxidant system. Various agonists, pathological conditions and therapeutic interventions lead to modulated expression and function of oxidant and antioxidant enzymes, including NAD(P)H oxidase, endothelial nitric oxide synthase, xanthine oxidase, myeloperoxidase, superoxide dismutases, catalase and glutathione peroxidase. ROS formed in vascular wall target a wide range of signaling molecules and cellular pathways in both endothelium and vascular smooth muscle, such as transcription factors, protein tyrosine phosphatase, protein tyrosine kinase, mitogen-activated protein kinase, Ca(2+)-transporting system and protein modification. ROS also have distinct physiological and pathophysiological impacts on vascular cells. ROS contribute to vascular dysfunction and remodeling through oxidative damage by (1) reducing the bioavailability of NO, (2) impairing endothelium-dependent vasodilatation and endothelial cell growth, (3) causing apoptosis or anoikis, (4) stimulating endothelial cell migration, and (5) activating adhesion molecules and inflammatory reaction, leading to endothelial dysfunction, an initial episode progressing toward hypertension and atherosclerosis. Cellular events underlying these processes involve changes in vascular smooth muscle cell growth, apoptosis/anoikis, cell migration, inflammation, and vasoconstriction. The present communication focuses on the biology of ROS signaling in vascular cells, discusses how oxidative stress contributes to vascular damage, and the therapeutic strategies/biotic factors that can prevent or treat ROS-associated cardiovascular disorders.
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PMID:Reactive oxygen species in vascular wall. 1672 32


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