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)

Early changes in the composition of heart muscle cells of the rat caused by an anabolic hormone were investigated by electron microscopy. Mitochondria and myofibrils showed changes similar to those observed in early heart failure: The mitochondria were swollen and elongated. Their matrix was sparse and the cristae were few in number. The myofibrils showed either disintegration and widened and twisted Z-bands or a complete dissolution of the sarcomeric units.
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PMID:Myocardial cell lesions caused by an anabolic hormone. 88 14

Our own previous ultrastructural studies in human hearts with dilated cardiomyopathy and heart failure showed sarcomeric and cytoskeletal disarrangement. On the basis of these findings we tested the hypothesis that in cardiomyopathic failing hearts not only the sarcomere structure but also the organization and the amount of numerous contractile proteins are disturbed. Titin was included in this study because it is the elastic "third" filament of the sarcomere and also plays an important role as template for myosin and actin filaments in sarcomerogenesis. Human cardiac tissue obtained at the time of transplantation surgery was investigated using immunohistochemistry with monoclonal antibodies against titin, myosin, actin, tropomyosin, and troponin T. Additionally, isolated myocytes from rat or pig heart were used for the standardization of the localization pattern. In normal tissue, myosin and the thin filament complex showed a regular cross striation that was wider in myosin staining than for actin, troponin T, and tropomyosin corresponding with the different width of the A and I bands in the sarcomere. Titin localization in normal human and animal myocardium showed a regular cross striation pattern. In diseased cardiac tissue titin fluorescence intensity was reduced and frequently disorganization or almost complete loss of titin from many myocytes were present. Severe abnormalities of contractile proteins consisting of disarrangement or lack of filaments were also observed. Double staining procedures showed that in the same myocyte defects of the contractile apparatus were accompanied by a simultaneous reduction of titin indicating that the "third" sarcomeric filament system is involved in heart failure. Abnormalities of titin expression may be especially important because titin significantly influences sarcomeric elastic behaviour and is necessary as template for the organization of newly synthesized myosin and actin filaments. The loss of titin may contribute to the altered compliance in failing hearts. It is concluded that disorganization and loss of titin, myosin, and the thin filament complex are severe in the failing human heart because of dilated cardiomyopathy and that these changes may represent several of the most important components of the structural correlate of reduced cardiac function.
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PMID:Altered expression of titin and contractile proteins in failing human myocardium. 786 90

Proliferating cell nuclear antigen (PCNA) is a late growth-regulated gene that is expressed at the G1-S boundary of the cell cycle and is required for DNA synthesis and cell proliferation. Since quantitative results suggest that myocyte hyperplasia occurs in the decompensated human heart, we postulated that induction of the PCNA gene may be present in the failing heart in humans. PCNA protein was detected in myocardial samples obtained from the left and right ventricles of patients with congestive heart failure. Endomyocardial biopsies collected from donor subjects were used as control tissue. The percentage of positively stained myocyte nuclei in the ventricles was established by using PCNA monoclonal antibody and the immunoperoxidase technique. The localization of PCNA in myocytes was confirmed by alpha-sarcomeric actin antibody staining. PCNA labeling was present in left ventricular myocytes of 29 of the 32 hearts examined. In the right ventricle, 24 of the 29 samples showed positive staining. In a subset of 25 patients, the percentage of PCNA-labeled myocyte nuclei was measured and found to constitute 49 +/- 22% of left ventricular myocytes. A similar analysis for the right ventricle, conducted in 21 patients, showed that 49 +/- 19% of the myocyte nuclei exhibited PCNA protein. In addition, mitotic figures in myocytes were documented. A quantitative analysis of this cellular process revealed that 11 myocyte nuclei per 1 million cells exhibited mitotic images in chronic heart failure. Immediately after myocardial infarction, two cells per million showed mitotic division, and this phenomenon was restricted to the region adjacent to the necrotic tissue. No PCNA labeling or nuclear mitotic images were detected in the ventricular myocardium of control subjects. Thus, the observation that diffuse PCNA labeling and myocyte mitotic division are present in hearts with end-stage failure strongly suggests that adult ventricular myocytes are not terminally differentiated cells and that myocyte cellular hyperplasia may constitute a growth reserve mechanism of the diseased heart.
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PMID:End-stage cardiac failure in humans is coupled with the induction of proliferating cell nuclear antigen and nuclear mitotic division in ventricular myocytes. 795 43

Cardiac hypertrophy and failure frequently cause complications in some cardiovascular diseases. Both conditions are associated with important modifications of the heart's contractile and endocrine functions, induced by various changes in gene expression, which in turn are attributable to chronic hemodynamic overload. Differential expression of the myosin heavy chain family leads to a disproportionate accumulation of the alpha form relative to the beta, which in turn causes slower but more efficient myocardial contraction. This transition occurs in the rodent ventricle and human atrium. In the sarcomeric actin family, both the alpha-cardiac and alpha-skeletal isoforms are expressed in the mammalian ventricle in utero. After birth, the latter transiently accumulates in the rodent ventricle at the acute phase of an experimental overload. In humans, alpha-skeletal actin accounts for over half of total actin; this ratio remains the same during heart failure. In experimental models of hemodynamic overload, and during heart failure in humans, expression of Ca(2+)-ATPase in the sarcoplasmic reticulum is reduced. This decrease may partly account for the changes in cardiac relaxation observed in these circumstances. The atrial natriuretic factor gene in the ventricular myocardium is also activated, permitting the ventricle to participate in the regulation of its loading conditions. Several mechanical and neurohumoral factors have been proposed as triggers for this gene reprogramming. Research is currently focussed on signal transduction mechanisms, and in particular identification of the transcription factors involved.
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PMID:[Plasticity of myocardial phenotype during cardiac hypertrophy and failure]. 822 Nov 90

In the mammalian heart, the development of cardiac hypertrophy is a common feature that normally precedes all forms of heart failure. This adaptive process involves molecular changes in the myocardium, including the altered expression of several genes encoding proteins for contraction and relaxation. The expression of myosin heavy chain (MHC) and sarcomeric alpha-actin messenger ribonucleic acid (mRNA) changes qualitatively during cardiac hypertrophy; however, their accumulations are not coordinated. Skeletal alpha-actin transcripts accumulate throughout the ventricles and earlier than beta-MHC transcripts, which accumulate primarily around large coronary vessels. Skeletal alpha-actin transcripts also "hyperaccumulate" relative to cardiac alpha-actin mRNA, whose expression does not change. Expression of MHC isomRNA shows an inverse relation; as beta-MHC accumulates, alpha-MHC decreases in abundance. From nuclear run-on assays, we present evidence that the accumulation of these gene products is at least under partial transcriptional control with developmental growth, suggesting that those changes that occur with hypertrophy and heart failure may be primarily transcriptionally regulated. The expression of the mRNA for the calcium-adenosine triphosphate (Ca(2+)-ATPase) of the sarcoplasmic reticulum changes quantitatively with cardiac hypertrophy without the reexpression of a different isoform. The relative mRNA and protein concentrations for this protein diminish with both cardiac hypertrophy and heart failure, a change that may partially explain the delayed relaxation rates seen in hypertrophied and failing hearts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The molecular biology of heart failure. 837 95

In recent years, the striking development of molecular biology and molecular genetic has brought completely new insights into the understanding of heart failure. Two aspects for which significant progress has been made in 1995 are discussed in this review: the genetic mechanisms of inherited cardiomyopathies and the molecular basis of heart failure due to chronic hemodynamic overload. In familial hypertrophic cardiomyopathy, a novel disease gene was found. It encodes myosin binding protein C, whose structure and function are poorly understood. Contractile deficits associated with the myosin mutations were demonstrated, and all this strengthened the hypothesis that hypertrophy is a compensatory mechanism that occurs in presence of a sarcomeric defect. These studies have important prognostic and clinical implications, but new and unexpected concerns have arisen, because a widespread difference in phenotype can be seen in patients harboring similar genotypes. In familial dilated cardiomyopathy, the main findings were the identification of four disease loci, but the genes are still unknown. With respect to the consequences of chronic hemodynamic overload on myocyte function and phenotype, recent data gave rise to lively discussions in the fields of reexpression of fetal troponin T isoforms and of decreased function and expression of the sarco(endo)plasmic reticulum Ca2+ ATPase in the failing human heart; at the moment it is difficult to draw definitive conclusions. Interestingly, three new concepts emerged in the understanding of the pathogenesis of heart failure: the increased contribution of the Na(+)-Ca2+ exchange, the possible recruitment of an inositol phosphate-sensitive calcium pool for myofibrillar activation, and the involvement of apoptotic myocyte and nonmyocyte cell death in myocardial remodeling.
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PMID:Molecular and cellular biology of heart failure. 883 64

The transition from compensated hypertrophy to failure in spontaneously hypertensive rats (SHR) of advanced age is associated with a marked increase in collagen, a reduction in myocyte mass, and a reduction in maximum Ca(2+)-activated myofibrillar force. We hypothesized that the reduction in myocyte mass and associated functional loss may be due to increased cell death by apoptosis. To test this hypothesis, we studied hearts from failing (SHR-F) and nonfailing SHR (SHR-NF) and age-matched Wistar-Kyoto rats (WKY). In addition, hearts from SHR-F that had been treated with an angiotensin-converting enzyme inhibitor (captopril) for an average of 27 days were also studied. Apoptotic cells were quantified in cross sections of myocardium by the terminal deoxynucleotidyltransferase- mediated 2'-deoxyuridine 5'-triphosphate nick end labeling technique. To identify the type of the cells undergoing apoptosis, sections were also stained for alpha-sarcomeric actin. Apoptotic cells were significantly increased in the SHR-F (38.92 +/- 12.79 vs. 8.05 +/- 3.98 cells/100,000 nuclei in SHR-NF; P < 0.05 and vs. 2.21 +/- 1.4 cells/100,000 nuclei in WKY; P < 0.01). Captopril treatment of SHR-F reduced the number of apoptotic cells to the level in SHR-NF (9.17 +/- 1.53 cells/100,000 nuclei; P < 0.01 vs. SHR-F). Most apoptotic cells were of cardiac myocyte origin. There was no significant difference in Bcl-2 protein expressed by hearts among the three groups. WAF-1 mRNA levels were increased in both SHR groups vs. WKY; in SHR-F, the density of WAF-1 mRNA was higher than in SHR-NF. Thus increased numbers of apoptotic cells are present in failing SHR hearts, suggesting that apoptosis might be a mechanism involved in the reduction of myocyte mass that accompanies the transition from stable compensation to heart failure in this model. Administration of the angiotensin-converting enzyme inhibitor captopril, which ameliorates heart failure in this model, is associated with a reduction in the exaggerated apoptosis that accompanies heart failure.
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PMID:Increased cardiomyocyte apoptosis during the transition to heart failure in the spontaneously hypertensive rat. 917

Cardiomyopathies, and more specifically hypertrophic cardiomyopathy, have opened the route to what is now called genetic cardiology. Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left and/or right ventricular hypertrophy, and disorganisation of tissular architecture. Approximately 60% of HCM are transmitted as an autosomal dominant trait. The clinical aspects of HCM vary markedly, and several morphological variants were described, depending on the localization of hypertrophy. This pathology is often complicated by cardiac failure, but the major risk is sudden death, and the predictive factors are presently very unrefined. Several pathogenic hypotheses were forwarded in the past, and one surprising result of genetic analyses is that none of these hypotheses was confirmed. Four disease genes were identified, and they encode sarcomeric proteins, cardiac myosin heavy chain, troponin T, tropomyosin and cardiac myosin binding protein C. To this high intergenic heterogeneity is associated a high intragenic heterogeneity. A major fall out of these genetic findings is the recent discovery of adult healthy carriers, around 30% in our experience. Genetype/phenotype relationships are being performed, and this is the first approach to a prognostic evaluation based on genetic localisation. The work on hypertrophic cardiomyopathy is currently being used as a model to analyse dilated cardiomyopathies, characterized by dilatation and impaired contraction of the left or both ventricles. The mode of inheritance of these forms of cardiomyopathies is complex. Five families with an autosomal inheritance were analyzed since two years, the loci were found, but the disease genes are not identified yet. Identification of patients at high risk and early treatment or prevention are the current goals.
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PMID:[Cardiomyopathies]. 929 66

p38 mitogen-activated protein (MAP) kinase activities were significantly increased in mouse hearts after chronic transverse aortic constriction, coincident with the onset of ventricular hypertrophy. Infection of cardiomyocytes with adenoviral vectors expressing upstream activators for the p38 kinases, activated mutants of MAP kinase kinase 3b(E) (MKK3bE) and MAP kinase kinase 6b(E) (MKK6bE), elicited characteristic hypertrophic responses, including an increase in cell size, enhanced sarcomeric organization, and elevated atrial natriuretic factor expression. Overexpression of the activated MKK3bE in cardiomyocytes also led to an increase in apoptosis. The hypertrophic response was enhanced by co-infection of an adenoviral vector expressing wild type p38 beta, and was suppressed by the p38 beta dominant negative mutant. In contrast, the MKK3bE-induced cell death was increased by co-infection of an adenovirus expressing wild type p38 alpha, and was suppressed by the dominant negative p38 alpha mutant. This provides the first evidence in any cell system for divergent physiological functions for different members of the p38 MAP kinase family. The direct involvement of p38 pathways in cardiac hypertrophy and apoptosis suggests a significant role for p38 signaling in the pathophysiology of heart failure.
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PMID:Cardiac muscle cell hypertrophy and apoptosis induced by distinct members of the p38 mitogen-activated protein kinase family. 944 57

Creatine kinase (CK) plays a crucial role in cardiac energy transduction. During chronic cardiac stress conditions leading to hypertrophy and/or heart failure, the profile of CK isoenzyme activities changes towards a fetal pattern with increases of BB- and MB-CK and decreases of MM-CK and mito-CK. Changes of myocardial CK gene expression are only indirectly reflected by measurements of CK activities. The purpose of this work was, therefore, to determine myocardial expression of B-, M- and sarcomeric mito-CK genes in an animal model of heart failure where hemodynamic alterations and CK system changes are well defined, that is, in the rat heart post-myocardial infarction. Intact residual left ventricular myocardium was harvested 2 months following infarction (MI; n = 7) or sham operation (sham; n = 6) after in vivo left-ventricular end-diastolic pressure (LVEDP) was recorded. Total CK activity was measured spectrophotometrically, CK isoenzyme distribution with agarose gel electrophoresis. Steady state mRNA levels coding for B-, M- and mito-CK genes were measured with quantitative PCR and were normalized for GAPDH expression. Total CK activity tended to be reduced in MI (5.51 +/- 0.62 IU/mg protein) compared to sham (6.77 +/- 0.24; P = 0.55). CK isoenzyme distribution showed an increase of fetal BB- + MB-CK (MI 22.0 +/- 3.1%, sham 15.1 +/- 1.0%; P < 0.05), no change of MM-CK and a decrease of mito-CK (27.0 +/- 1.5% sham, 20.8 +/- 2.0% MI: P < 0.05). Relative B-CK mRNA levels increased (sham 0.46 +/- 0.06, MI 1.03 +/- 0.09; P < 0.05) and M-CK mRNA levels decreased (sham 1.06 +/- 0.08. MI 0.66 +/- 0.09; P < 0.05) significantly post-MI. The increase of B-CK mRNA (r = 0.72; P = 0.009) and the decrease of M-CK mRNA (r = 0.76; P = 0.003) correlated significantly with in vivo LVEDP. Mito-CK mRNA levels remained unchanged after MI (sham 0.94 +/- 0.16, MI 0.98 +/- 0.09). Intact residual left-ventricular myocardium post-MI is characterized by increased B-CK-mRNA and reduced M-CK-mRNA expression.
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PMID:Changes of creatine kinase gene expression in rat heart post-myocardial infarction. 960 29


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