Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0018801 (
heart failure
)
72,216
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
End-stage human
heart failure
is associated with changes in expression of steady-state messenger RNA (mRNA) levels. These changes correspond to alterations in protein levels and myocardial function and may have clinical implications regarding etiology, clinical state, or prognosis. However, analysis of mRNA levels in endomyocardial biopsies can be accomplished only by the quantitative polymerase chain reaction, which is difficult to standardize. The aim of the study was to evaluate whether the RNase protection assay is applicable to measure mRNAs of multiple genes simultaneously in small amounts of ventricular myocardium comparable to myocardial biopsies. Total RNA was prepared from left ventricular myocardium from terminally failing hearts with idiopathic (n=9) or ischemic cardiomyopathy (n=7) and from nonfailing control hearts (n=10). mRNA was measured by an optimized RNase protection assay for the beta1-adrenoceptor, the stimulatory G protein alpha-subunit (Gsalpha), phospholamban, the
calcium ATPase
of the sarcoplasmic reticulum (SERCA), beta-myosin heavy chain (beta-MHC), and the atrial natriuretic peptide (ANP). We extracted 10.7+/-2.1 microg total RNA from three myocardial biopsies taken in vitro. All of the six genes were measurable in duplicate in a total of 7 microg RNA. mRNAs of beta1-adrenoceptor, phospholamban, and SERCA were lower in failing than in nonfailing myocardium by 50%, 33%, and 42% respectively, whereas beta-MHC and Gsalpha mRNAs were unchanged. mRNA of ANP was expressed at high levels only in the failing myocardium, providing a highly specific and sensitive marker for discriminating nonfailing and failing hearts. A direct comparison with ANP and Gsalpha levels obtained by Northern blot analysis with 7.5 microg total RNA showed a good correlation between the two methods. The RNase protection assay is thus a suitable method for simultaneous measurements of multiple mRNA levels in human myocardial biopsies. Changes in mRNA levels closely reflected those identified by other methods using larger amounts of RNA. Increased myocardial ANP mRNA levels determined by the RNase protection assay may serve as a molecular marker of
heart failure
.
...
PMID:Analysis of gene expression patterns in small amounts of human ventricular myocardium by a multiplex RNase protection assay. 950 Jun 79
In mammalian myocardium, relaxation is mainly triggered by the reuptake of calcium from the cytosol to the lumen of the sarcoplasmic reticulum (SR) through the cardiac isoform of the sarco(endo)plasmic reticulum
calcium ATPase
, SERCA2a. Relaxation abnormalities related to deficient SR Ca(2+)-uptake have been identified in human
heart failure
and in animal models of cardiac hypertrophy and failure. These alterations have been associated with a reduction in SERCA2a activity and in steady-state SERCA2a protein and mRNA levels. As a first step in the analysis of the mechanisms responsible for this reduction, we have studied a possible down-regulation of the SERCA2 gene transcription during left ventricular hypertrophy (LVH) induced by constriction of the ascending aorta in the rat. Quantifications of the mRNA levels demonstrated no alteration, compared to sham-operated rats, at 5 d after imposition of the pressure overload, whereas a significant decrease was observed at 11 d. Transcription in-vitro experiments (cardiac nuclear run-on assays) performed in isolated cardiomyocytes nuclei showed no changes at 5 d and a 37% reduction of the SERCA2 gene transcription at 11 d. These results strongly suggest that SERCA2 gene expression down-regulation during cardiac hypertrophy occurs, at least in part, at the level of the transcription.
...
PMID:The sarco(endo)plasmic reticulum Ca(2+)-ATPase gene is regulated at the transcriptional level during compensated left ventricular hypertrophy in the rat. 958 74
A pressure-overload model in the rat by banding the pulmonary trunk (PT) was developed to investigate alterations in gene expression in left- and right-ventricular compartments during the transition from compensated right-ventricular (RV) hypertrophy to right heart failure. Right heart failure in rat is characterized by liver cirrhosis, hydrothorax and ascites. The diameter of constriction was found to determine the time course of
heart failure
development. Only the RV free wall and the right atrium increased in weight, without a difference between compensated and failing RV. An increase in circulating ANP revealed a hypertrophic response of the myocardium, while increased circulating ammonia levels discriminated between compensated hypertrophy and failure. As parameters for stress, fibrosis and Ca2+-handling, changes in the pattern and level of the mRNAs encoding atrial natriuretic peptide (ANP), collagenIIIalpha1, and sarcoplasmic endoplasmic reticular
calcium ATPase
2 (SERCA2), phospholamban (PLB) and calsequestrin (CSQ) were studied by Northern blot and in situ hybridization analyses. Pulmonary trunk banding resulted in an induction of ANP mRNA, a moderate increase in collagenIII alpha1 mRNA and a decrease in SERCA2 and PLB mRNA levels in both the left and right ventricles, but changes were most pronounced in the myocardium surrounding the RV cavity. Increased ammonia blood levels are a promising prognostic marker to detect the development of right heart failure.
...
PMID:Changing patterns of gene expression in the pulmonary trunk-banded rat heart. 976 42
During administration of the anthracycline antitumour agents, their cardiotoxicity can progress from cardiac dysfunction to
heart failure
. Cardiomyopathy can also develop years after receiving anthracyclines. To determine if persistent and/or progressive anthracycline effect(s) are referable to anthracycline effects on cardiac gene expression, steady-state mRNA levels were determined 4 days (n=8), 4 weeks (n=7) and 10 weeks (n=7) after doxorubicin (DOX; 2 mg/kg IV) in a well-characterized rabbit model. Levels of mRNA for alpha -actin, beta -myosin heavy chain and the
calcium pump
of the sarcoplasmic reticulum (SERCA2a) in the left ventricle (LV) were determined by Northern blot hybridization and expressed relative to an 18S constitutive marker. The mRNA levels for the high molecular weight subunit (cardiac isoform) of the ryanodine receptor (RyR2), sarcolemmal calcium channel (dihydropyridine receptor; DHPR), angiotensin-converting enzyme (ACE), angiotensin II receptor (ATR) and atrial naturetic peptide prohormone (ANP) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis, and expressed relative to GAPDH, a constitutive marker. Histopathologic evidence for anthracycline-induced myocardial cell injury was absent (score <1) in all hearts examined except one (score=1.1; 4 weeks post-DOX), which was considered separately. Relative mRNA levels for beta -myosin heavy chain 4 days after DOX increased 1.9-fold compared to the vehicle-treated group, but by 4 weeks levels had returned to baseline. Relative mRNA levels for DHPR were increased 1.2-fold 4 days after DOX and were persistently increased 1.9- and 2.2-fold 4 and 10 weeks after DOX, respectively. The mRNA levels for ANP were first decreased (4.5-fold) 4 days after DOX. Four weeks after DOX, ANP message levels approached Control in seven out of eight rabbits. The one rabbit with early LV histopathology 4 weeks post-DOX had increased mRNA for DHPR (2.7-fold) and ANP (80-fold). Between 4 and 10 weeks after DOX, mRNA levels for ANP increased C 16-fold: evidence for late progression. In situ hybridization with specific riboprobes localized the persistent increase in DHPR and the progressive increase in ANP to myocytes. Thus, DOX alters steady-state mRNA levels in LV that are referable to both persistent and progressive anthracycline effects on myocellular gene expression.
...
PMID:Persistent effects of doxorubicin on cardiac gene expression. 1042 42
Accumulating evidence points to the critical role of phospholamban (PLB) regulation of the cardiac sarcoplasmic reticulum (SR)
calcium ATPase
in influencing the kinetics of calcium handling within the cardiac myocyte under normal and pathological conditions. Based on the data, it has been hypothesized that PLB inhibitors (e.g.,
calcium ATPase
stimulators) would be of potential importance as positive lusitropes and inotropes in the treatment of
heart failure
. Experiments measuring tension transients in saponin-permeabilized cardiac muscles from genetically engineered mice under a variety of SR calcium loading conditions provide evidence of the functional alterations that can be achieved by manipulation of the degree of PLB inhibition of the
calcium pump
. Testing of the above hypothesis will ultimately require a selective, high-affinity, membrane-permeable small molecule stimulator of the cardiac
calcium pump
. Screening for cardiac
calcium pump
activators has produced a series of agents exerting apparently different mechanisms of action; some may be tools to help to elucidate the nature of the PLB-
calcium ATPase
interaction(s). The rationale for PLB as a drug target, the optimal profile of a PLB inhibitor, and the properties of several low-molecular-weight compounds will be explored.
...
PMID:Pharmacology of the cardiac sarcoplasmic reticulum calcium ATPase-phospholamban interaction. 1060 85
Alterations in gene expression are a hallmark of cardiac hypertrophy and
heart failure
. Among these, the decreased expression of the sarcoplasmic reticulum
calcium ATPase
(SERCA2) has been described. Elevated levels of cytokines in particular, Leukemia Inhibitory Factor (LIF) and Interleukin-6 (IL-6) have been shown to have the capacity to elicit hypertrophic responses in cultured cardiac myocytes. In this study, we investigated the effects of these cytokines (LIF & IL-6) on the regulation of SERCA2 levels in cardiac myocytes. Cultured neonatal rat ventricular myocytes were transfected with a 3.2 kb promoter plasmid construct containing the SERCA2 promoter linked to a chloramphenicol acetyltransferase (CAT) reporter gene, and subsequently treated with 10 ng/ml LIF or 10 ng/ml IL-6. LIF and IL-6 independently caused a significant (p < or = 0.05) 23-36% inhibition in SERCA2 promoter activity. LIF and IL-6 induced inhibition was also evident in SERCA2 mRNA levels as assessed by Northern analysis. Time course of inhibition of SERCA2 mRNA levels showed the most prominent decrease occurring after 48 hours of treatment, with both cytokines having a dose dependent effect on the inhibitory response. Western analysis using a polyclonal antibody to SERCA2 protein indicate a significant, 60% decrease in the amount of total SERCA2 protein in cultured myocytes treated with 10 ng/ml LIF or IL-6. In conclusion, the cytokines LIF and IL-6 downregulate SERCA2 gene expression and protein levels. The molecular mechanism responsible for cytokine induced downregulation of SERCA2 is at least partly transcriptional.
...
PMID:Leukemia Inhibitory Factor and Interleukin-6 downregulate sarcoplasmic reticulum Ca2+ ATPase (SERCA2) in cardiac myocytes. 1075 45
Nitric oxide (NO) has effects on contractility, energetics and gene expression of failing myocardium. Initial studies on isolated cardiomyocytes showed NO to reduce systolic shortening but intracoronary infusions of NO-donors or of NO synthase (NOS) inhibitors failed to elicit changes in baseline LV contractility indices such as LVdP/dt(max). Intracoronary infusions of NO-donors or of substance P, which releases NO from the coronary endothelium, however demonstrated NO to induce a downward displacement of the left ventricular (LV) diastolic pressure-volume relation, consistent with increased LV diastolic distensibility. In end-stage failing myocardium, the increased oxygen consumption is related to reduced NO production and in isolated cardiomyocytes, NO blunts the norepinephrine-induced expression of the fetal gene programme thereby preserving myocardial calcium homeostasis.In dilated cardiomyopathy, changed endomyocardial NOS gene expression has been reported. Because of lower endomyocardial NOS gene expression in patients with higher functional class and lower LV stroke work, increased endomyocardial NOS gene expression seems to be beneficial rather than detrimental for the failing heart. A beneficial effect of increased NOS gene expression could result from NO's ability to increase LV diastolic distensibility, to augment LV preload reserve, to reduce myocardial oxygen consumption and to prevent downregulation of
calcium ATPase
. Upregulated endomyocardial NOS gene expression has also been reported in athlete's heart and could therefore play a role in physiological LV remodeling. Reduced endomyocardial NO content because of decreased NO or increased superoxide production could lower LV diastolic distensibility and contribute to diastolic
heart failure
. In many conditions such as aging, hypertension, diabetes or posttransplantation, the increased incidence of diastolic
heart failure
is indeed paralleled by reduced endothelium-dependent vasodilation.
...
PMID:The role of nitric oxide in the failing heart. 1130 29
Heart failure
is characterized by depressed contractility and delayed repolarization. The latter feature predisposes the failing heart to ventricular arrhythmias and represents a logical target for gene therapy. Unfortunately, unopposed correction of the delay in repolarization will decrease the time available for calcium cycling during each heartbeat, potentially aggravating the depression of contractility. Here we describe the development and application of a novel gene therapy strategy designed to abbreviate excitation without depressing contraction. The
calcium ATPase
SERCA1 was coexpressed with the potassium channel Kir2.1 in guinea pig hearts. Myocytes from the hearts had bigger calcium transients and shorter action potentials. In vivo, repolarization was abbreviated, but contractile function remained unimpaired. Dual gene therapy of the sort described here can be generalized to exploit opposing or synergistic therapeutic principles to achieve a tailored phenotype.
...
PMID:Dual gene therapy with SERCA1 and Kir2.1 abbreviates excitation without suppressing contractility. 1182 99
Glycogen synthase kinase (GSK) 3beta is a negative regulator of stress-induced cardiomyocyte hypertrophy. It is not clear, however, if GSK-3beta plays any role in regulating normal cardiac growth and cardiac function. Herein we report that a transgenic mouse expressing wild type GSK-3beta in the heart has a dramatic impairment of normal post-natal cardiomyocyte growth as well as markedly abnormal cardiac contractile function. The most striking phenotype, however, is grossly impaired diastolic relaxation, which leads to increased filling pressures of the left ventricle and massive atrial enlargement. This is due to profoundly abnormal calcium handling, leading to an inability to normalize cytosolic [Ca2+] in diastole. The alterations in calcium handling are due at least in part to direct down-regulation of the sarcoplasmic reticulum
calcium ATPase
(SERCA2a) by GSK-3beta, acting at the level of the SERCA2 promoter. These studies identify GSK-3beta as a regulator of normal growth of the heart and are the first of which we are aware, to demonstrate regulation of expression of SERCA2a, a critical determinant of diastolic function, by a cytosolic signaling pathway, the activity of which is dynamically modulated. De-regulation of GSK-3beta leads to severe systolic and diastolic dysfunction and progressive
heart failure
. Because down-regulation of SERCA2a plays a central role in the diastolic and systolic dysfunction of patients with
heart failure
, these findings have potential implications for the therapy of this disorder.
...
PMID:Glycogen synthase kinase-3beta regulates growth, calcium homeostasis, and diastolic function in the heart. 1502 May 84
Many cardiovascular disease states end in progressive
heart failure
. Changes in intracellular calcium handling, including a reduced activity of the sarcoplasmic reticulum
calcium pump
(SERCA), contribute to this contractile dysfunction. As the regulatory protein phospholamban can inhibit the
calcium pump
, we evaluated it as a potential target to improve cardiac function. In this study, we describe a recombinant antibody-based protein (PLN-Ab) that binds to the cytoplasmic domain of phospholamban. Fluorescence resonance energy transfer (FRET) studies suggest that PLN-Ab mimics the effects of phospholamban phosphorylation. PLN-Ab accelerated the decay of the calcium transient when expressed in neonatal rat and adult mouse ventricular cardiac myocytes. In addition, direct injection of adenovirus encoding PLN-Ab into the diabetic mouse heart enhanced contractility when measured in vivo by echocardiography and in ex vivo Langendorff perfused hearts. The PLN-Ab provides a novel therapeutic approach to improving contractility through in vivo expression of an antibody inside cardiac myocytes.
...
PMID:A recombinant antibody increases cardiac contractility by mimicking phospholamban phosphorylation. 1518 Sep 62
<< Previous
1
2
3
4
5
6
7
8
9
Next >>