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)

Membrane-bound and secreted neuregulin isoforms induce growth, survival and differentiation by activating erbB tyrosine kinase receptors. In cultured cardiomyocytes, erbB2 and erbB4 receptors regulate apoptosis by controlling bcl-x splicing, and conditional elimination of erbB2 induces dilative cardiomyopathy in vivo. Therefore, we analyzed expression and activation of erbB receptors in left ventricular myocardium from 32 heart failure patients, from 10 organ donors, and from 15 heart failure patients prior to and following unloading by ventricular assist devices. ErbB receptors, expressed in cardiomyocytes and noncardiomyocytes, are downregulated in failing myocardium as mRNA (which is renormalized by hemodynamic unloading) and as protein (erbB2: -25%; erbB4: -70%), their phosphorylation is reduced and bcl-x splicing is shifted towards 6.7-fold augmentation of proapoptotic Bcl-xS, compatible with attenuated erbB signaling. However, secreted and membrane-anchored neuregulin-1 isoforms, preferentially expressed in microvascular endothelium, are induced and not lowered with heart failure, while expression of erbB-inhibitory neuregulin isoforms or of autoinhibitory soluble erbB isoforms could not be demonstrated as potential causes of erbB receptor inhibition. We conclude that erbB receptor inactivation by unknown mechanisms results in altered splicing of bcl-x towards enhanced formation of proapoptotic Bcl-xS, thereby contributing to enhanced apoptotic susceptibility of failing human myocardium.
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PMID:Neuregulin receptors erbB2 and erbB4 in failing human myocardium -- depressed expression and attenuated activation. 1568 97

This article reviews the types and roles of voltage-independent Ca(2+) channels involved in the endothelin-1 (ET-1)-induced functional responses such as vascular contraction, cell proliferation, and intracellular Ca(2+)-dependent signaling pathways and discusses the molecular mechanisms for the activation of voltage-independent Ca(2+) channels by ET-1. ET-1 activates some types of voltage-independent Ca(2+) channels, such as Ca(2+)-permeable nonselective cation channels (NSCCs) and store-operated Ca(2+) channels (SOCC). Extracellular Ca(2+) influx through these voltage-independent Ca(2+) channels plays essential roles in ET-1-induced vascular contraction, cell proliferation, activation of epidermal growth factor receptor tyrosine kinase, regulation of proline-rich tyrosine kinase, and release of arachidonic acid. The experiments using various constructs of endothelin receptors reveal the importance of G(q) and G(12) families in activation of these Ca(2+) channels by ET-1. These findings provide a potential therapeutic mechanism of a functional interrelationship between G(q)/G(12) proteins and voltage-independent Ca(2+) channels in the pathophysiology of ET-1, such as in chronic heart failure, hypertension, and cerebral vasospasm.
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PMID:Involvement of extracellular Ca2+ influx through voltage-independent Ca2+ channels in endothelin-1 function. 1589 64

The octapeptide angiotensin II (ANG II) can modulate cardiac contractility and is increased in heart failure, where contractile function is impaired. In rat cardiac myocytes, 1 microM of ANG II produces a negative inotropic effect (NIE) (24.6 +/- 5% reduction). However, the subcellular signaling involved in this effect remains elusive. We examined the mechanisms and signaling events involved in the reduction in contractile function induced by the peptide in indo-1-loaded rat cardiomyocytes. The results showed that the NIE of ANG II was not associated with a parallel decrease in the intracellular Ca2+ transient, indicating that a decrease in myofilament responsiveness to Ca2+ underlies the reduction in contractility. We assessed the role of PKC, tyrosine kinases, reactive oxygen species (ROS), and mitogen-activated protein kinases (MAPKs) in the NIE of the peptide. Pretreatment of cells with the NAD(P)H oxidase inhibitor diphenyleneiodonium chloride or with the superoxide scavenger 4,5-dihydroxy-1,3-benzene-disulfonic acid did not affect the ANG II-induced NIE. Moreover, ANG II-induced ROS production, after 20 min of incubation with the peptide, could not be detected with the use of either the fluorophore 5-(6)-chloromethyl-2',7'-dichlorodihydrofluorecein diacetate or lucigenin-enhanced chemiluminescence. In contrast, the ANG II-induced NIE was abrogated by the inhibitors of PKC (calphostin C), tyrosine kinase (genistein), and p38 MAPK (SB-202190). Furthermore, the NIE was significantly exacerbated (60 +/- 10% reduction) by p38 MAPK overexpression. These results exclude the participation of ROS in the NIE of the peptide and point to PKC and tyrosine kinase as upstream mediators. Furthermore, they reveal p38 MAPK as the putative effector of the reduction in myofilament responsiveness to Ca2+ and the decrease in contractility induced by the peptide.
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PMID:Angiotensin II-induced negative inotropy in rat ventricular myocytes: role of reactive oxygen species and p38 MAPK. 1637 94

Viral myocarditis can present as dramatic heart failure in the young, and chronic indolent cardiomyopathy in the older adult. The outcome of the disease is still poor, associated with high mortality during long-term follow-up. Enteroviral myocarditis serves as an excellent model to understand virus and host interactions. The virus enters the target cells via collaborating receptors, and this process triggers an inflammatory response in the host. The immune reaction is a two-edged sword, with appropriate activation of the immune system capable of clearing the virus, but excessive activation leads to a chronic inflammatory process that triggers the remodeling of the heart and consequent clinical heart failure. Through genetic dissection strategies, we have identified that the acquired immune system is activated through the T cell receptor and signaling amplification systems, such as the tyrosine kinase p56lck, phosphatase CD45 and downstream ERK1/2, and the family of cytokines. This signaling system not only promotes inflammatory cell clonal expansion but paradoxically also promotes viral proliferation. The innate immune system is now recognized as playing an ever-expanding role in coordinating the host immune response through the Toll-like receptors, triggering downstream signaling adaptors such as MyD88, IRAK, and TRIF/IRFs. These lead to activation of cytokines or interferons, depending on the balance of the signal contributions. The ongoing research in this area should help us to understand the immune response of the heart to viral infection, while identifying potential targets for therapy.
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PMID:Recent insights into the role of host innate and acquired immunity responses. 1632 61

Since its introduction 6 years ago, imatinib mesylate, a selective tyrosine kinase inhibitor, has been a phenomenon in treating chronic myelogenous leukemia (CML) with remarkably superior cytogenetic and molecular response rates at all stages of CML followed by longer progression free survival. Despite its extraordinarily high efficacy, adverse effects of imatinib mesylate such as edema, liver toxicity and fluid retention syndromes have been reported. Here we, for the first time, report development of heart failure in patients on imatinib mesylate medication and the possibility of brain natriuretic peptide (BNP) as a potential diagnostic (or predicting) marker for heart failure. Since plasma BNP levels in the two patients were exceptionally high, we then explored the possibility of genetic association of BNP with the development of heart failure to find no positive association.
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PMID:BNP as a marker of the heart failure in the treatment of imatinib mesylate. 1638 97

The central role of phosphatidylinositol 3-kinase (PI3K, p110alpha) signaling in allowing cancer cells to bypass normal growth-limiting controls has led to the development of PI3K(p110alpha) inhibitors. A challenge in targeting PI3K(p110alpha) relates to the diverse actions of the PI3K pathway in numerous cell types. Recent findings in mice deficient in PI3K(p110alpha) activity in the heart, demonstrate the critical role of this pathway in protecting the heart against pathological insults. Mice deficient in PI3K(p110alpha) displayed accelerated heart failure in response to dilated or hypertrophic cardiomyopathy. These results help explain the association of cardiomyopathy in cancer patients given tyrosine kinase inhibitors and raise concerns for the use of PI3K(p110alpha) inhibitors in cancer patients with cardiovascular risk factors. Interestingly, an inhibitor of the mammalian target of rapamycin (a downstream effector of PI3K), did not have adverse effects on the heart. A more complete understanding of the complex arms and interactions of the PI3K pathway will hopefully lead to the development of anti-cancer agents without cardiac complications.
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PMID:PI3K(p110alpha) inhibitors as anti-cancer agents: minding the heart. 1740 10

(1) Sunitinib, a tyrosine kinase inhibitor, is marketed for the treatment of advanced-stage and metastatic renal carcinoma, and for second-line treatment of gastrointestinal stromal tumours. Sorafenib arrived on the market almost simultaneously for second-line treatment of kidney cancer. (2) In second-line treatment of kidney cancer, two non comparative trials showed an unusually high rate of at least partial tumour regression with sunitinib (25%, compared to only 2% with sorafenib). Head-to-head trials of the two drugs are lacking. Although indirect comparisons are notoriously unreliable, sunitinib appears to provide longer progression-free survival than sorafenib (about 9 months versus 5.5 months), although overall survival times are similar. (3) Preliminary results of a trial comparing sunitinib with interferon alfa as first-line treatments in 750 patients with kidney cancer show a 6-month event-free survival advantage in the sunitinib arm. The precise overall survival time has not yet been calculated. (4) In 312 patients with gastrointestinal stromal tumours in whom imatinib has failed, a double-blind placebo-controlled trial showed that sunitinib prolonged overall survival time, but potential biases undermine these results. (5) The adverse effect profile of sunitinib appears to be similar to those of imatinib and sorafenib, apart from more thyroid disorders. The principal adverse effects are cutaneous, gastrointestinal, cardiovascular and haematological disorders. Arterial hypertension, sometimes severe, occurred in 16% of patients treated with sunitinib. Other serious adverse events included tumour haemorrhage and pulmonary embolism. A risk of cardiac toxicity leading to heart failure cannot currently be ruled out. (6) Sunitinib is metabolised by cytochrome P450 isoenzyme CYP 3A4, increasing the likelihood of drug interactions. (7) These results support the use of sunitinib as second-line therapy for patients with gastrointestinal stromal tumours. Additional clinical evaluation is needed, however. In first-line treatment of kidney cancer, it is preferable to wait for detailed results of the ongoing trial, especially effects on survival time, before judging the possible advantages and disadvantages of sunitinib compared to interferon alfa. In second-line treatment, sorafenib is better-assessed than sunitinib and should therefore be preferred, pending a direct comparison of the two drugs.
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PMID:Sunitinib: new drug. For some gastrointestinal stromal tumours. 1772 33

Voltage-dependent calcium channels (VDCCs) play a pivotal role in normal excitation-contraction coupling in cardiac myocytes. These channels can be modulated through activation of beta-adrenergic receptors (beta-ARs), which leads to an increase in calcium current (I(Ca-L)) density through cardiac Ca(v)1 channels as a result of phosphorylation by cAMP-dependent protein kinase A. Changes in I(Ca-L) density and kinetics in heart failure often occur in the absence of changes in Ca(v)1 channel expression, arguing for the importance of post-translational modification of these channels in heart disease. The precise molecular mechanisms that govern the regulation of VDCCs and their cell surface localization remain unknown. Our data show that sustained beta-AR activation induces internalization of a cardiac macromolecular complex involving VDCC and beta-arrestin 1 (beta-Arr1) into clathrin-coated vesicles. Pretreatment of myocytes with pertussis toxin prevents the internalization of VDCCs, suggesting that G(i/o) mediates this response. A peptide that selectively disrupts the interaction between Ca(V)1.2 and beta-Arr1 and tyrosine kinase inhibitors readily prevent agonist-induced VDCC internalization. These observations suggest that VDCC trafficking is mediated by G protein switching to G(i) of the beta-AR, which plays a prominent role in various cardiac pathologies associated with a hyperadrenergic state, such as hypertrophy and heart failure.
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PMID:beta-Adrenergic receptor activation induces internalization of cardiac Cav1.2 channel complexes through a beta-arrestin 1-mediated pathway. 2181 27

(1) Imatinib, a tyrosine kinase inhibitor, was first marketed for the treatment of chronic myeloid leukaemia and some gastrointestinal stromal tumours. Its indications have gradually expanded over the years. (2) There is no consensus treatment for adults with Philadelphia chromosome-positive acute lymphoblastic leukaemia. In a trial comparing imatinib versus chemotherapy as initial treatment for 55 patients, the haematological response rate was higher with imatinib. Non-comparative trials provided haematological response rates of about 90%, but it is not known whether or not this translates into a survival advantage. In three non-comparative trials including patients with relapsed or refractory disease after chemotherapy, 50% of patients showed a survival time of at least 7 months. In the absence of any direct comparisons, we do not know if this represents an improvement over the results obtained with the best palliative care. (3) The only potential cure for myelodysplastic syndromes is allogeneic haematopoietic stem cell transplantation but this is not always feasible. Some myelodysplastic syndromes are associated with myeloproliferation and PDGFR gene rearrangements; imatinib is the first drug available for these patients. The manufacturer has compiled data on 55 patients treated with imatinib. Most patients had a favourable haematological response, but no survival data were published. (4) The severity of the hypereosinophilic syndrome is highly variable. Forms associated with FIP1L1-PDGFRalpha gene rearrangements have a poor prognosis. Clinical evaluation of imatinib in this setting is based on a compilation of data concerning 176 treated patients. The haematological response rate was high in patients with the mutant gene, but it is not known whether this translated into increased survival. (5) Dermatofibrosarcoma protuberans is a rare form of mainly localised skin cancer. Treatment is based on surgical excision but relapses are frequent. In one series, 9 out of 12 patients treated with imatinib had at least a partial tumour response, making surgical excision possible in 3 cases. (6) Imatinib has diverse and frequent adverse effects; nausea and vomiting, oedema, fluid retention, cutaneous disorders and heart failure. There is some evidence pointing to a risk of urologic cancers and altered bone metabolism.
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PMID:Imatinib: new indication. New indications, but not robust evidence. 1862 99

Hypereosinophilic syndrome (HES) is a rare disorder characterized by persistent marked eosinophilia combined with eosinophil-mediated organ damage. Myeloproliferative variants are associated with a high prevalence of cardiac involvement, which is very unusual in lymphocytic variants. Imatinib mesylate (Gleevec(R)) is a small molecule with tyrosine kinase activity that has shown marked effects in some individuals with HES. In this case report, we present a patient with a hypereosinophilic syndrome (lymphocytic variant) that first manifested as hypereosinophilia and heart failure secondary mainly to right ventricle systolic dysfunction. A week after imatinib therapy instauration the eosinophil count was within normal range but the patient suffered a severely left ventricular dysfunction that was restablished after early drug withdrawal. Surgical removal of a new onset mass in right atrium was required because of progressively growth despite anticoagulant therapy. Clinicians should be aware of the variable heart manifestations in patients with HES and the potential cardiotoxicity of imatinib.
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PMID:Atypical cardiac manifestation of hypereosinophilic syndrome and reversible cardiotoxicity to imatinib. 1905 37


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