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)

Vagal nerve stimulation has been suggested to ameliorate left ventricular (LV) remodeling in heart failure. However, it is not known whether and to what degree vagal nerve stimulation affects matrix metalloproteinase (MMP) and tissue inhibitor of MMP (TIMP) in myocardium, which are known to play crucial roles in LV remodeling. We therefore investigated the effects of electrical stimulation of efferent vagal nerve on myocardial expression and activation of MMPs and TIMPs in a rabbit model of myocardial ischemia-reperfusion (I/R) injury. Anesthetized rabbits were subjected to 60 min of left coronary artery occlusion and 180 min of reperfusion with (I/R-VS, n = 8) or without vagal nerve stimulation (I/R, n = 7). Rabbits not subjected to coronary occlusion with (VS, n = 7) or without vagal stimulation (sham, n = 7) were used as controls. Total MMP-9 protein increased significantly after left coronary artery occlusion in I/R-VS and I/R to a similar degree compared with VS and sham values. Endogenous active MMP-9 protein level was significantly lower in I/R-VS compared with I/R. TIMP-1 mRNA expression was significantly increased in I/R-VS compared with the I/R, VS, and sham groups. TIMP-1 protein was significantly increased in I/R-VS and VS compared with the I/R and sham groups. Cardiac microdialysis technique demonstrated that topical perfusion of acetylcholine increased dialysate TIMP-1 protein level, which was suppressed by coperfusion of atropine. Immunohistochemistry demonstrated a strong expression of TIMP-1 protein in cardiomyocytes around the dialysis probe used to perfuse acetylcholine. In conclusion, in a rabbit model of myocardial I/R injury, vagal nerve stimulation induced TIMP-1 expression in cardiomyocytes and reduced active MMP-9.
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PMID:Efferent vagal nerve stimulation induces tissue inhibitor of metalloproteinase-1 in myocardial ischemia-reperfusion injury in rabbit. 1769 45

Extracellular matrix metalloproteinase inducer (EMMPRIN) expression is increased in myocardium from patients with dilated cardiomyopathy and animal models of heart failure. However, little is known about the regulated expression or functional role of EMMPRIN in the myocardium. In rat cardiac cells, EMMPRIN is expressed on myocytes but not endothelial cells or fibroblasts. Therefore, we tested the hypothesis that EMMPRIN expression regulates matrix metalloproteinase (MMP) activity in rat ventricular myocytes in vitro. In adult rat ventricular myocytes (ARVM), beta-adrenergic receptor (betaAR) stimulation and H(2)O(2) (24 h) each increased EMMPRIN expression as assessed by immunoblotting. Pretreatment with a catalase/superoxide dismutase mimetic or adenoviral-mediated expression of catalase or a dominant-negative c-jun N-terminal kinase-1 (JNK) mutant inhibited the betaAR- and H(2)O(2)-stimulated increases in EMMPRIN expression suggesting that EMMPRIN expression is regulated via a reactive oxygen species-dependent JNK pathway. To determine whether EMMPRIN expression regulates matrix metalloproteinase (MMP) activity, EMMPRIN activity was inhibited by adenoviral expression of an inhibitory mutant of EMMPRIN. Expression of mutant EMMPRIN inhibited the betaAR-stimulated increases in MMP2 expression and zymographic MMP activity. Thus, in cardiac myocytes betaAR stimulation induces the expression of EMMPRIN via the ROS-dependent activation of JNK. The resulting increase in EMMPRIN activity stimulates MMP expression and activity. These findings suggest that in the myocardium the regulated expression of EMMPRIN is a determinant of MMP activity and may thus play a role in myocardial remodeling.
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PMID:EMMPRIN mediates beta-adrenergic receptor-stimulated matrix metalloproteinase activity in cardiac myocytes. 1786 66

It is now becoming apparent that dynamic changes occur within the interstitium that directly contribute to adverse myocardial remodeling following myocardial infarction (MI), with hypertensive heart disease and with intrinsic myocardial disease such as cardiomyopathy. Furthermore, a family of matrix proteases, the matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs), has been recognized to play an important role in matrix remodeling in these cardiac disease states. The purpose of this review is fivefold: 1) to examine and redefine the myocardial matrix as a critical and dynamic entity with respect to the remodeling process encountered with MI, hypertension, or cardiomyopathic disease; 2) present the remarkable progress that has been made with respect to MMP/TIMP biology and how it relates to myocardial matrix remodeling; 3) to evaluate critical translational/clinical studies that have provided a cause-effect relationship between alterations in MMP/TIMP regulation and myocardial matrix remodeling; 4) to provide a critical review and analysis of current diagnostic, prognostic, and pharmacological approaches that utilized our basic understanding of MMP/TIMPs in the context of cardiac disease; and 5) most importantly, to dispel the historical belief that the myocardial matrix is a passive structure and supplant this belief that the regulation of matrix protease pathways such as the MMPs and TIMPs will likely yield a new avenue of diagnostic and therapeutic strategies for myocardial remodeling and the progression to heart failure.
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PMID:Myocardial matrix remodeling and the matrix metalloproteinases: influence on cardiac form and function. 1792 85

Increased signaling by G(i)-coupled receptors has been implicated in dilated cardiomyopathy. To investigate the mechanisms, we used transgenic mice that develop dilated cardiomyopathy after conditional expression of a cardiac-targeted G(i)-coupled receptor (Ro1). Activation of G(i) signaling by the Ro1 agonist spiradoline caused decreased cellular cAMP levels and bradycardia in Langendorff-perfused hearts. However, acute termination of Ro1 signaling with the antagonist nor-binaltorphimine did not reverse the Ro1-induced contractile dysfunction, indicating that Ro1 cardiomyopathy was not due to acute effects of receptor signaling. Early after initiation of Ro1 expression, there was a 40% reduction in the abundance of the sarcoplasmic reticulum Ca(2+)-ATPase (P < 0.05); thereafter, there was progressive impairment of both Ca(2+) handling and force development assessed with ventricular trabeculae. Six weeks after initiation of Ro1 expression, systolic Ca(2+) concentration was reduced to 0.61 +/- 0.08 vs. 0.91 +/- 0.07 microM for control (n = 6-8; P < 0.05), diastolic Ca(2+) concentration was elevated to 0.41 +/- 0.07 vs. 0.23 +/- 0.06 microM for control (n = 6-8; P < 0.01), and the decline phase of the Ca(2+) transient (time from peak to 50% decline) was slowed to 0.25 +/- 0.02 s vs. 0.13 +/- 0.02 s for control (n = 6-8; P < 0.01). Early after initiation of Ro1 expression, there was a ninefold elevation of matrix metalloproteinase-2 (P < 0.01), which is known to cause myofilament injury. Consistent with this, 6 wk after initiation of Ro1 expression, Ca(2+)-saturated myofilament force in skinned trabeculae was reduced to 21 +/- 2 vs. 38 +/- 0.1 mN/mm(2) for controls (n = 3; P < 0.01). Furthermore, electron micrographs revealed extensive myofilament damage. These findings may have implications for some forms of human heart failure in which increased activity of G(i)-coupled receptors leads to impaired Ca(2+) handling and myofilament injury, contributing to impaired ventricular pump function and heart failure.
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PMID:Expression of a Gi-coupled receptor in the heart causes impaired Ca2+ handling, myofilament injury, and dilated cardiomyopathy. 1796 83

Cardiovascular disease is the number-one cause of mortality in the developed world. The aim of this study is to define the mechanisms by which bone marrow progenitor cells are mobilized in response to cardiac ischemic injury. We used a closed-chest model of murine cardiac infarction/reperfusion, which segregated the surgical thoracotomy from the induction of cardiac infarction, so that we could study isolated fluctuations in cytokines without the confounding impact of surgery. We show here that bone marrow activation of the c-kit tyrosine kinase receptor in response to released soluble KitL is necessary for bone marrow progenitor cell mobilization after ischemic cardiac injury. We also show that release of KitL and c-kit activation require the activity of matrix metalloproteinase-9 within the bone marrow compartment. Finally, we demonstrate that mice with c-kit dysfunction develop cardiac failure after myocardial infarction and that bone marrow transplantation rescues the failing cardiac phenotype. In light of the ongoing trials of progenitor cell therapy for heart disease, our study outlines the endogenous repair mechanisms that are invoked after cardiac injury. Amplification of this pathway may aid in restoration of cardiac function after myocardial infarction.
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PMID:Activation of c-kit is necessary for mobilization of reparative bone marrow progenitor cells in response to cardiac injury. 1796 25

Neutrophils are thought to orchestrate myocardial remodeling during the early progression to cardiac failure through the release of reactive oxygen species, antimicrobial peptides, and proteases. Although neutrophil activation may be beneficial at early stages of disease, excessive neutrophil infiltration can induce cardiomyocyte death and tissue damage. The neutrophil-derived serine protease cathepsin G (Cat.G) has been shown to induce neonatal rat cardiomyocyte detachment and apoptosis by anoikis. However, the involved signaling mechanisms for Cat.G are not well understood. This study identifies epidermal growth factor receptor (EGFR) transactivation as a mechanism whereby Cat.G induces signaling in cardiomyocytes. Cat.G induced a rapid and transient increase in EGFR tyrosine phosphorylation, and inhibition of EGFR kinase activity, either with AG1478 or by expression of kinase inactive EGFR mutants (EGFR-CD533), markedly attenuated EGFR downstream signaling and myocyte anoikis induced by Cat.G. Consistent with this effect of EGFR, high level expression of wild-type EGFR was sufficient to promote myocyte apoptosis. We also found that matrix metalloproteinase-dependent membrane shedding of heparin-binding EGF was involved in Cat.G signaling and that membrane type 1 matrix metalloproteinase activation may constitute a potential target that entails matrix metalloproteinase activation induced by Cat.G. The paradoxical proapoptotic effect of EGFR appeared to be dependent on protein tyrosine phosphatase SHP2 (Src homology domain 2-containing tyrosine phosphatase 2) activation and focal adhesion kinase downregulation. These results show that Cat.G-induced cardiomyocyte apoptosis involves an increase in EGFR-dependent activation of SHP2 that promotes focal adhesion kinase dephosphorylation and subsequent cardiomyocyte anoikis.
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PMID:Novel mode for neutrophil protease cathepsin G-mediated signaling: membrane shedding of epidermal growth factor is required for cardiomyocyte anoikis. 1797 13

Left ventricular (LV) remodeling leads to congestive heart failure and is a main determinant of morbidity and mortality following myocardial infarction. Therapeutic options to prevent LV remodeling are limited, which necessitates the exploration of alternative therapeutic targets. Toll-like receptors (TLRs) serve as pattern recognition receptors within the innate immune system. Activation of TLR4 results in an inflammatory response and is involved in extracellular matrix degradation, both key processes of LV remodeling following myocardial infarction. To establish the role of TLR4 in postinfarct LV remodeling, myocardial infarction was induced in wild-type BALB/c mice and TLR4-defective C3H-Tlr4(LPS-d) mice. Without affecting infarct size, TLR4 defectiveness reduced the extent of LV remodeling (end-diastolic volume: 103.7+/-6.8 microL versus 128.5+/-5.7 microL; P<0.01) and preserved systolic function (ejection fraction: 28.2+/-3.1% versus 16.6+/-1.3%; P<0.01), as assessed by MRI. In the noninfarcted area, interstitial fibrosis, and myocardial hypertrophy were reduced in C3H-Tlr4(LPS-d) mice. In the infarcted area, however, collagen density was increased, which was accompanied by fewer macrophages, reduced inflammation regulating cytokine expression levels (interleukin [IL]-1alpha, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, tumor necrosis factor-alpha, interferon-gamma, granulocyte/macrophage colony-stimulating factor), and reduced matrix metalloproteinase-2 (4684+/-515 versus 7573+/-611; P=0.002) and matrix metalloproteinase-9 activity (76.0+/-14.3 versus 168.0+/-36.2; P=0.027). These data provide direct evidence for a causal role of TLR4 in postinfarct maladaptive LV remodeling, probably via inflammatory cytokine production and matrix degradation. TLR4 may therefore constitute a novel target in the treatment of ischemic heart failure.
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PMID:Toll-like receptor 4 mediates maladaptive left ventricular remodeling and impairs cardiac function after myocardial infarction. 1823 39

Although cardiac synchronization is important in maintaining myocardial performance, the mechanism of dys-synchronization in ailing to failing myocardium is unclear. It is known that the cardiac myocyte contracts and relaxes individually; however, it synchronizes only when connected to one another by low resistance communications called gap junction protein (connexins) and extra cellular matrix (ECM). Therefore, the remodeling of connexins and ECM in heart failure plays an important role in cardiac conduction, synchronization and arrhythmias. This review for the first time addresses the role of systemic accumulation of homocysteine (Hcy) in vasospasm, pressure and volume overload heart failure, hypertension and cardiac arrhythmias. The attenuation of calcium-dependent mitochondrial (mt), endothelial and neuronal nitric oxide synthase (mtNOS, eNOS and nNOS) by Hcy plays a significant role in cardiac arrhythmias. The signal transduction mechanisms in Hcy-induced matrix metalloproteinase (MMP) activation in cardiac connexin remodeling are discussed.
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PMID:Cardiac dys-synchronization and arrhythmia in hyperhomocysteinemia. 1804 55

Suppressed parasympathetic nervous system (PSNS) function has been found in a variety of cardiovascular diseases, such as hypertension, heart failure, and diabetes. However, whether impaired PSNS function plays a significant role in ventricular dysfunction remains to be investigated. Cardiac regulation by the PSNS is primarily mediated by the M(2) muscarinic acetylcholine receptor (M(2)-AChR). In this study, we tested the hypothesis that lack of M(2)-AChR-mediated PSNS function may adversely impact cardiac ventricular function. Using M(2)-AChR knockout (KO) and wild-type (WT) mice, we found that the basal levels of heart rate and left ventricular function were similar in M(2)-AChR KO and WT mice. A bolus injection of isoproterenol (Iso) induced a greater increase in heart rate in M(2)-AChR KO mice than in WT mice. However, the responses of change in pressure over time (dP/dt) to Iso were similar in the two groups. After chronic infusion with Iso for 1 wk, the baseline values of left ventricular function were increased to similar extents in M(2)-AChR KO and WT mice. However, the M(2)-AChR KO mice exhibited impaired ventricular function, indicated as attenuated dP/dt and increased end-diastolic pressure, during an increase in cardiac afterload induced by a bolus injection of phenylephrine. Furthermore, chronic Iso infusion significantly increased matrix metalloproteinase (MMP) activity in the heart in M(2)-AChR KO mice. In primary culture of mixed neonatal rat cardiac fibroblast and cardiomyocytes, cotreatment with muscarinic agonist bethanechol reversed phenylephrine-induced increase in MMP-9 activation. These data suggest that M(2)-AChR may mediate an inhibitory regulation on MMP function. The overall results from this study suggest that M(2)-AChR-mediated PSNS function may provide cardiac protection. Lack of this protective mechanism will increase the susceptibility of the heart to cardiac stresses.
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PMID:Deficiency of M2 muscarinic acetylcholine receptors increases susceptibility of ventricular function to chronic adrenergic stress. 1805 17

Epimedium, a traditional Chinese herb, has been used for the remedy of coronary heart disease, impotence and osteoporosis in traditional oriental medicine. However, despite extensive pharmacological studies, the molecular mechanism of the anti-heart failure effect of epimedium is little known. In the present study, we investigated the pharmacological action mechanism of ethanol extract of epimedium (EPI-ext) on isoproterenol-induced congestive heart failure (CHF) in rats. Isoproterenol administration resulted in severe heart failure, as shown by the increased levels of left ventricular (LV) weight index and heart rate, as well as LV end diastolic pressure, and by the decreased levels of LV systolic pressure, maximal rate of LV pressure rise, and maximal rate of LV pressure decline. EPI-ext dose-dependently reversed the changes of these cardiac morphometric and hemodynamic parameters. In addition, EPI-ext significantly inhibited the serum levels of tumor necrosis factor alpha, norepinephrine, angiotensin II and brain natriuretic peptide in rats with CHF and improved the histological changes including cadiocyte hypertrophy, cadiocyte degeneration, inflammatory infiltration, and cardiac desmoplasia. Furthermore, the expression and activities of matrix metalloproteinase-2 and -9, which regulate collagen production, were also blocked by EPI-ext. Moreover, myocardial apoptosis was remarkably attenuated by EPI-ext through the regulating Bcl-2/Bax axle. In conclusion, EPI-ext ameliorates LV dysfunction and cardiac remodeling through down-regulating matrix metalloproteinase-2 and -9 activity and myocardial apoptosis in rats with CHF.
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PMID:Ethanol extract from Epimedium brevicornum attenuates left ventricular dysfunction and cardiac remodeling through down-regulating matrix metalloproteinase-2 and -9 activity and myocardial apoptosis in rats with congestive heart failure. 1809 24


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