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)

We sought to determine whether skeletal myoblasts, wild-type or engineered to express relaxin, might improve myocardial viability and performance in a rat model of chronic myocardial infarction. Our purpose was to investigate a potential new therapy for heart failure. From October 2005 through September 2009, we surgically induced acute myocardial infarction in 80 male Wistar rats. Thirty days after surgery, the rats underwent reoperation for the retrograde coronary venous infusion of skeletal myoblasts, relaxin, or both. The animals were randomly assigned to 4 experimental groups: R1 (the control group, which underwent saline-solution infusion), R2 (systemic relaxin therapy), R3 (myoblast infusion), and R4 (myoblast infusion and systemic relaxin therapy). Echocardiography, positron emission tomography, and cellular and histologic analysis were performed at 4 established time points. Mortality rates were similar among the groups. Postinfarction echocardiographic evaluation revealed similar left ventricular dysfunction. Viable myocardium, evaluated with positron emission tomography, was analogous. After therapy, the echocardiographic values of cardiac function improved significantly (P<0.05) in all groups except R1. Myocardial viability volume increased significantly in groups R3 and R4 (P<0.05) but was unchanged in groups R2 and R1. In group R4, the echocardiographic and positron emission tomographic results improved significantly (P<0.001). Histologic analysis showed that myoblasts settled in regions of ischemic scarring, especially when combined with relaxin. The retrograde venous route is safe, effective, and clinically feasible for cell delivery. Myoblasts and relaxin are better than either alone in terms of myocardial viability and performance improvement.
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PMID:Cellular retrograde cardiomyoplasty and relaxin therapy for postischemic myocardial repair in a rat model. 2294 64

Human gene-2 (H2) relaxin is currently in Phase III clinical trials for the treatment of acute heart failure. It is a 53-amino acid insulin-like peptide comprising two chains and three disulfide bonds. It interacts with two of the relaxin family peptide (RXFP) receptors. Although its cognate receptor is RXFP1, it is also able to cross-react with RXFP2, the native receptor for a related peptide, insulin-like peptide 3. In order to understand the basis of this cross-reactivity, it is important to elucidate both binding and activation mechanisms of this peptide. The primary binding mechanism of this hormone has been extensively studied and well defined. H2 relaxin binds to the leucine-rich repeats of RXFP1 and RXFP2 using B-chain-specific residues. However, little is known about the secondary interaction that involves the A-chain of H2 relaxin and transmembrane exoloops of the receptors. We demonstrate here through extensive mutation of the A-chain that the secondary interaction between H2 relaxin and RXFP1 is not driven by any single amino acid, although residues Tyr-3, Leu-20, and Phe-23 appear to contribute. Interestingly, these same three residues are important drivers of the affinity and activity of H2 relaxin for RXFP2 with additional minor contributions from Lys-9, His-12, Lys-17, Arg-18, and Arg-22. Our results provide new insights into the mechanism of secondary activation interaction of RXFP1 and RXFP2 by H2 relaxin, leading to a potent and RXFP1-selective analog, H2:A(4-24)(F23A), which was tested in vitro and in vivo and found to significantly inhibit collagen deposition similar to native H2 relaxin.
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PMID:Identification of key residues essential for the structural fold and receptor selectivity within the A-chain of human gene-2 (H2) relaxin. 2302 63

Heart failure is an important public health problem that is increasing in prevalence throughout the world. Not only is this condition common, but it is associated with significant morbidity and mortality as well as high costs to medical care systems. Vasodilator drugs help unload the heart and may have other effects that could benefit heart failure patients. Consequently, they have emerged as an important therapeutic approach for patients with this condition. Novel vasodilator therapies that are currently in development target new pathways, potentially giving clinicians alternate options for improving outcomes in this vulnerable population. This review focuses on investigational drugs that have the ability to dilate blood vessels amongst their therapeutic properties. These drugs include the natriuretic peptides that activate particulate guanylate cyclase, the novel agent cinaciguat that activates the soluble guanylate cyclase system, and finally a recombinant form of the naturally occurring vasodilating agent relaxin, a hormone that mediates many of the changes that allows the cardiovascular system to successfully adapt to pregnancy.
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PMID:Novel vasodilators in heart failure. 2329 83

Acute heart failure is a public health issue with morbidity and mortality exceeding that of myocardial infarction. Novel compounds for the treatment of acute heart failure are clearly needed and fall into the general categories of inotropic, vasodilatory and other compounds in phase I to III of development. Furthest along are omecamtiv mecarbil (a cardiac myosin activator), ularitide (a natriuretic and diuretic peptide) and relaxin (a vasodilator). Each compound has a unique set of assets and liabilities that will aid in the understanding of the syndrome and application to the right patients at the right time in this heterogeneous syndrome. This review will explore current and future novel pharmacologic therapies for the treatment of acute heart failure.
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PMID:Novel pharmacologic therapies in development for acute decompensated heart failure. 2331 27

Human relaxin-2 (hereafter simply defined as "relaxin") is a 6-kDa peptidic hormone best known for the physiological role played during pregnancy in the growth and differentiation of the reproductive tract and in the renal and systemic hemodynamic changes. This factor can also be involved in the pathophysiology of arterial hypertension and heart failure, in the molecular pathways of fibrosis and cancer, and in angiogenesis and bone remodeling. It belongs to the relaxin peptide family, whose members comprehensively exert numerous effects through interaction with different types of receptors, classified as relaxin family peptide (RXFP) receptors (RXFP1, RXFP2, RXFP3, RXFP4). Research looks toward the in-depth examination and complete understanding of relaxin in its various pleiotropic actions. The intent is to evaluate the likelihood of employing this substance for therapeutic purposes, for instance in diseases where a deficit could be part of the underlying pathophysiological mechanisms, also avoiding any adverse effect. Relaxin is already being considered as a promising drug, especially in acute heart failure. A careful study of the different RXFPs and their receptors and the comprehension of all biological activities of these hormones will probably provide new drugs with a potential wide range of therapeutic applications in the near future.
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PMID:Relaxin: new pathophysiological aspects and pharmacological perspectives for an old protein. 2340 Nov 42

Over the last decade, the treatment of heart failure has seen the introduction of several novel therapeutic avenues into the guidelines; however, these were mostly devoted to device therapies. Not much has changed with regards to the pharmacological treatment of this syndrome. Serelaxin, a recombinant form of the human peptide hormone relaxin-2, is a promising treatment candidate for patients presenting with acute heart failure. The Relaxin in Acute Heart Failure (RELAX-AHF) trial has shown beneficial effects in terms of relief of dyspnea and congestion in these patients. Even beneficial effects on short-term survival were reported. Another treatment approach to acute heart failure was pursued in the Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF) trial but the ultrafiltration used here lead to significantly worsened renal function as compared to standard pharmacologic care. Multicenter Automatic Defibrillator Implantation Trial - Reduce Inappropriate Therapy (MADIT-RIT) randomized patients with heart failure with a primary preventive indication for the implantation of an implantable cardioverter defibrillator to one of three algorithms for anti-tachycardia pacing (ATP) and shock. The authors found that initiation of such therapies only at higher heart rates than commonly used as threshold and longer time delays before the initiation of therapy may have two big advantages: the more conservative algorithms lead to a significant reduction in the cumulative probability of first inappropriate therapy and, even more striking, a reduced probability of death during follow-up. Biventricular versus Right Ventricular Pacing in Patients with Left Ventricular Dysfunction and Atrioventricular Block (BLOCK-HF) showed beneficial outcomes for cardiac resynchronization therapy in heart failure patients with a mere pacemaker indication. Other studies discussed here embraced the course of body wasting, particularly cachexia, and muscle wasting in patients with heart failure and the influence of eating behavior.
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PMID:Recent developments in the treatment of heart failure: highlights from the American Heart Association's Scientific Sessions, Los Angeles, California, 3 - 7 December 2012. 2365 25

Acute decompensated heart failure (ADHF) is a complex clinical event associated with excess morbidity and mortality. Managing ADHF patients is challenging because of the lack of effective treatments that both reduce symptoms and improve clinical outcomes. Existing guideline recommendations are largely based on expert opinion, but several recently published trials have yielded important data to inform both current clinical practice and future research directions. New insight has been gained regarding volume management, including dosing strategies for intravenous loop diuretics and the role of ultrafiltration in patients with heart failure and renal dysfunction. Although the largest ADHF trial to date (ASCEND-HF, using nesiritide) was neutral, promising results with other investigational agents have been reported. If these findings are confirmed in phase III trials, novel compounds, such as relaxin, omecamtiv mecarbil, and ularitide, among others, may become therapeutic options. Translation of research findings into quality clinical care can not be overemphasized. Although many gaps in knowledge exist, ongoing studies will address issues around delivery of evidence-based care to achieve the goal of improving the health status and clinical outcomes of patients with ADHF.
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PMID:Acute decompensated heart failure: update on new and emerging evidence and directions for future research. 2374 86

The anti-fibrotic, vasodilatory and pro-angiogenic therapeutic properties of recombinant relaxin peptide hormone have been investigated in several diseases, and recent clinical trial data has shown benefit in treating acute heart failure. However, the remodelling capacity of these peptide hormones is difficult to study in chronic settings because of their short half-life and the need for intravenous administration. Here we present the first small-molecule series of human relaxin/insulin-like family peptide receptor 1 agonists. These molecules display similar efficacy as the natural hormone in several functional assays. Mutagenesis studies indicate that the small molecules activate relaxin receptor through an allosteric site. These compounds have excellent physical and in vivo pharmacokinetic properties to support further investigation of relaxin biology and animal efficacy studies of the therapeutic benefits of relaxin/insulin-like family peptide receptor 1 activation.
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PMID:Identification and optimization of small-molecule agonists of the human relaxin hormone receptor RXFP1. 2376 25

Patients presenting with acute heart failure (AHF) represent a heterogeneous population with respect to demographics, clinical profiles, and precipitating factors. Despite this, most clinical trials have treated the study population as a homogeneous group in an attempt to achieve adequate statistical power for endpoint analysis. This approach has proven to be of little value in the development of new agents for treatment of AHF. By contrast, the phase III clinical trial of relaxin focused on a subset of AHF patients who were normotensive or hypertensive and who had moderate renal impairment. The study patients, who were primarily from Eastern Europe, represented a population that would be expected to have less genetic variability than the study populations in larger multinational AHF trials. A focused study design targeting specific patient profiles should be considered for future clinical AHF trials that investigate new therapies or compare the effectiveness of existing therapies.
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PMID:Relaxin for treatment of acute heart failure: making the case for treating targeted patient profiles. 2383 12

The peptide hormone relaxin is showing potential as a treatment for acute heart failure. Although it is known that relaxin mediates its actions through the G protein-coupled receptor relaxin family peptide receptor 1 (RXFP1), little is known about the molecular mechanisms by which relaxin binding results in receptor activation. Previous studies have highlighted that the unique N-terminal low density lipoprotein class A (LDLa) module of RXFP1 is essential for receptor activation, and it has been hypothesized that this module is the true "ligand" of the receptor that directs the conformational changes necessary for G protein coupling. In this study, we confirmed that an RXFP1 receptor lacking the LDLa module binds ligand normally but cannot signal through any characterized G protein-coupled receptor signaling pathway. Furthermore, we comprehensively examined the contributions of amino acids in the LDLa module to RXFP1 activity using both gain-of-function and loss-of-function mutational analysis together with NMR structural analysis of recombinant LDLa modules. Gain-of-function studies with an inactive RXFP1 chimera containing the LDLa module of the human LDL receptor (LB2) demonstrated two key N-terminal regions of the module that were able to rescue receptor signaling. Loss-of-function mutations of residues in these regions demonstrated that Leu-7, Tyr-9, and Lys-17 all contributed to the ability of the LDLa module to drive receptor activation, and judicious amino acid substitutions suggested this involves hydrophobic interactions. Our results demonstrate that these key residues contribute to interactions driving the active receptor conformation, providing further evidence of a unique mode of G protein-coupled receptor activation.
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PMID:The relaxin receptor (RXFP1) utilizes hydrophobic moieties on a signaling surface of its N-terminal low density lipoprotein class A module to mediate receptor activation. 2392 99


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