Pharmacological treatment of chronic heart failure

Adverse drug events and the associated factors in patients with chronic Chagas disease

INTRODUCTION:

Herein, we aimed to identify the factors associated with adverse drug events (ADEs) in chronic Chagas disease (CD) patients.

METHODS:

We analyzed 320 medical notes from 295 patients. The Naranjo algorithm was applied to determine the cause of ADEs. Mixed effects logistic regression was performed to evaluate the factors associated with ADEs.

RESULTS:

ADEs were described in 102 medical notes (31.9%). Captopril was most frequently associated with ADEs. Age (RR 0.96; 95%CI 0.94-0.99) and cardiac C/D stages (RR 3.24; 95%CI 1.30-4.58) were the most important clinical factors associated with ADEs.

CONCLUSIONS:

Close follow-up is warranted for CD patients.

Clinical efficacy and safety of Danhong injection for the treatment of chronic heart failure: A protocol for systematic review

BACKGROUND

Danhong injection (DHI) has been widely in the treatment of chronic heart failure (CHF) in China; however, there is not enough clinical evidence DHI for treating CHF.

METHODS

Two researchers will search literatures of DHI for CHF in databases. Extracted data are analyzed with Review Manager 5.3 software. The selected studies should be conducted quality evaluation, forest plots and funnel plots will be run by RevMan5.3.

RESULTS

This systematic review validates the clinical efficacy and safety of DHI in the treatment of CHF through the analysis of New York Heart Association functional classification, left ventricular ejection fraction, left ventricular end-diastolic dimension, cardiac output, brain natriuretic peptide, adverse events.

CONCLUSIONS

This systematic review will be provided a rational clinical evidence to evaluate the effectiveness and safety of DHI for the treatment of CHF.

REGISTRATION NUMBER

PROSPERO CRD42019144686.

Is Stem Cell Therapy an Answer to Heart Failure: A Literature Search

The heart is one of the most industrious organs in the human body. It starts beating in the first few weeks of embryonic life and keeps pumping blood till death. This organ can host a range of diseases as well. Some can hamper the vasculature, while others can affect its electrical activity, the heart valves, etc. All these conditions can lead to end-stage failure where it can no longer meet the requirements of the body’s milieu. This imbalance between supply and demand leads to an array of symptoms. Medical management can reduce these clinical effects and possibly prolong the life expectancy in such patients. However, prescription medications can also have their own adverse effects. This necessitates that each line of treatment should be assessed on a risk vs benefit basis. The conventional approach has been to try and slow down the progression of heart failure (HF). However, the inception of stem cells in the management of HF has the potential for reversal of this pathology. Keeping this in view, many studies and trials are under process. To turn the clock back on the HF, before complications set in or get out of control, is the main focus of the time. This article attempts to evaluate various studies about stem cell therapy (SCT) and highlight the important aspects of this novel modality in changing patients' lives.

The standardized Withania somnifera Dunal root extract alters basal and morphine-induced opioid receptor gene expression changes in neuroblastoma cells

Background

Behavioral studies demonstrated that the administration of Withania somnifera Dunal roots extract (WSE), prolongs morphine-elicited analgesia and reduces the development of tolerance to the morphine’s analgesic effect; however, little is known about the underpinning molecular mechanism(s). In order to shed light on this issue in the present paper we explored whether WSE promotes alterations of μ (MOP) and nociceptin (NOP) opioid receptors gene expression in neuroblastoma SH-SY5Y cells.

Methods

A range of WSE concentrations was preliminarily tested to evaluate their effects on cell viability. Subsequently, the effects of 5 h exposure to WSE (0.25, 0.50 and 1.00 mg/ml), applied alone and in combination with morphine or naloxone, on MOP and NOP mRNA levels were investigated.

Results

Data analysis revealed that morphine decreased MOP and NOP receptor gene expression, whereas naloxone elicited their up-regulation. In addition, pre-treatment with naloxone prevented the morphine-elicited gene expression alterations. Interestingly, WSE was able to: a) alter MOP but not NOP gene expression; b) counteract, at its highest concentration, morphine-induced MOP down-regulation, and c) hamper naloxone-induced MOP and NOP up-regulation.

Conclusion

Present in-vitro data disclose novel evidence about the ability of WSE to influence MOP and NOP opioid receptors gene expression in SH-SY5Y cells. Moreover, our findings suggest that the in-vivo modulation of morphine-mediated analgesia by WSE could be related to the hindering of morphine-elicited opioid receptors down-regulation here observed following WSE pre-treatment at its highest concentration.

Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy

BACKGROUND

Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in people with Chagas disease. This is an update of a Cochrane review published in 2012.

OBJECTIVES

To assess the clinical benefits and harms of current pharmacological interventions for treating heart failure in people with Chagas cardiomyopathy.

SEARCH METHODS

We updated the searches in the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2016, Issue 1), MEDLINE (Ovid; 1946 to to February Week 1 2016), EMBASE (Ovid; 1947 to 2016 Week 07), LILACS (1982 to 15 February 2016), and Web of Science (Thomson Reuters; 1970 to 15 February 2016). We checked the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) that assessed the effects of pharmacological interventions to treat heart failure in adult patients (18 years or older) with symptomatic heart failure (New York Heart Association classes II to IV), regardless of the left ventricular ejection fraction stage (reduced or preserved), with Chagas cardiomyopathy. We did not apply limits to the length of follow-up. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time-to-heart decompensation, disease-free period (at 30, 60, and 90 days), and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, 'Risk of bias' assessment and data extraction. We estimated relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I² statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. We developed 'Summary of findings' (SoF) tables and used GRADE methodology to assess the quality of the evidence.

MAIN RESULTS

In this update, we identified one new trial. Therefore, this version includes three trials (108 participants). Two trials compared carvedilol against placebo and another assessed rosuvastatin versus placebo. All trials had a high risk of bias.Meta-analysis of two trials showed a lower proportion of all-cause mortality in the carvedilol groups compared with the placebo groups (RR 0.69; 95% CI 0.12 to 3.88, I² = 0%; 69 participants; very low-quality evidence). Neither of the trials reported on cardiovascular mortality, time-to-heart decompensation, or disease-free periods.One trial (30 participants) found no difference in hospital readmissions (RR 1.00; 95% CI 0.31 to 3.28; very low-quality of evidence) or reported adverse events (RR 0.92; 95% CI 0.67 to 1.27; very low-quality of evidence) between the carvedilol and placebo groups.There was very low-quality evidence from two trials of inconclusive effects on quality of life (QoL) between the carvedilol and placebo groups. One trial (30 participants) assessed QoL with the Minnesota Living With Heart Failure Questionnaire (21 items; item scores range from 0 to 5; a lower MLHFQ score is better). The MD was -14.74; 95% CI -24.75 to -4.73. The other trial (39 participants) measured QoL with the Medical Outcomes Study 36-item short-form health survey (SF-36; item scores range from 0 to 100; higher SF-36 score is better). Data were not provided.One trial (39 participants) assessed the effect of rosuvastatin versus placebo. The trial did not report on any primary outcomes or adverse events. There was very low-quality evidence of uncertain effects on QoL (no data were provided).

AUTHORS' CONCLUSIONS

This first update of our review found very low-quality evidence for the effects of either carvedilol or rosuvastatin, compared with placebo, for treating heart failure in people with Chagas disease. The three included trials were underpowered and had a high risk of bias. There were no conclusive data to support or reject the use of either carvedilol or rosuvastatin for treating Chagas cardiomyopathy. Unless randomised clinical trials provide evidence of a treatment effect, and the trade-off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending or administering either carvedilol or rosuvastatin to treat heart failure in people with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in people with Chagas disease remains unknown.

Contrasting effects of cardiac glycosides on cisplatin- and etoposide-induced cell death

Cardiac glycosides (CGs) or cardiotonic steroids, which constitute a group of naturally occurring compounds with a steroid-like structure, can act on Na+/K+-ATPase as a receptor and activate intracellular signaling messengers leading to a variety of cellular responses. Epidemiological studies have revealed that CGs, used for the treatment of cardiac disorders, may also be beneficial as anti-cancer agents. CGs, acting in combination with other chemotherapeutic agents, may significantly alter their efficiency in relation to cancer cell elimination, causing both sensitization and an increase in cancer cell death, and in some cases resistance to chemotherapy. Here we show the ability of CGs to modulate apoptotic response to conventionally used anti-cancer drugs. In combination with etoposide, CGs digoxin may enhance cytotoxic potential, thereby allowing the chemotherapeutic dose to be decreased and minimizing toxicity and adverse reactions. Mechanisms behind this event are discussed.

Managing therapeutic competition in patients with heart failure, lower urinary tract symptoms and incontinence

Up to 50 % of heart failure patients suffer from lower urinary tract symptoms. Urinary incontinence has been associated with worse functional status in patients with heart failure, occurring three times more frequently in patients with New York Heart Association Class III and IV symptoms compared with those with milder disease. The association between heart failure and urinary symptoms may be directly attributable to worsening heart failure pathophysiology; however, medications used to treat heart failure may also indirectly provoke or exacerbate urinary symptoms. This type of drug–disease interaction, in which the treatment for heart failure precipitates incontinence, and removal of medications to relieve incontinence worsens heart failure, can be termed therapeutic competition. The mechanisms by which heart failure medication such as diuretics, angiotensin-converting enzyme (ACE) inhibitors and β-blockers aggravate lower urinary tract symptoms are discussed. Initiation of a prescribing cascade, whereby antimuscarinic agents or β3-agonists are added to treat symptoms of urinary urgency and incontinence, is best avoided. Recommendations and practical tips are provided that outline more judicious management of heart failure patients with lower urinary tract symptoms. Compelling strategies to improve urinary outcomes include titrating diuretics, switching ACE inhibitors, treating lower urinary tract infections, appropriate fluid management, daily weighing, and uptake of pelvic floor muscle exercises.

Co(III)(salen)-catalyzed phenolic kinetic resolution of two stereocentered benzyloxy and azido epoxides: its application in the synthesis of ICI-118,551, an anti-hypertensive agent

The salen Co(III)-catalyzed phenolic kinetic resolution of racemic anti- or syn-azido and benzyloxy epoxides provides a practical route to a range of enantioenriched anti- or syn-1-aryloxy-3-azido or benzyloxy-2-alcohols in excellent yields and ees. The synthetic potential of this protocol is illustrated with an enantioselective synthesis of ICI-118,551, a β-blocker, in a highly optically pure form (99% ee).

CpG-ODN attenuates pathological cardiac hypertrophy and heart failure by activation of PI3Kα-Akt signaling

Phosphoinositide-3-kinase α (PI3Kα) represents a potential novel drug target for pathological cardiac hypertrophy (PCH) and heart failure. Oligodeoxynucleotides containing CpG motifs (CpG-ODN) are classic agonists of Toll-like receptor 9 (TLR9), which typically activates PI3K-Akt signaling in immune cells; however, the role of the nucleotide TLR9 agonists in cardiac myocytes is largely unknown. Here we report that CpG-ODN C274 could both attenuate PCH and improve cardiac dysfunction by activating PI3Kα-Akt signaling cascade. In vitro studies indicated that C274 could blunt reactivation of fetal cardiac genes and cell enlargement induced by a hypertrophic agent, isoproterenol. The anti-hypertrophic effect of C274 was suppressed by a pan-PI3K inhibitor, LY294002, or a small interfering RNA targeting PI3Kα. In vivo studies demonstrated that PCH, as marked by increased heart weight (HW) and cardiac ANF mRNA, was normalized by pre-administration with C274. In addition, Doppler echocardiography detected cardiac ventricular dilation, and contractile dysfunction in isoproterenol-treated animals, consistent with massive replacement fibrosis, reflecting cardiac cell death. As expected, pre-treatment of mice with C274 could prevent cardiac dysfunction associated with diminished cardiac cell death and fibrosis. In conclusion, CpG-ODNs are novel cardioprotective agents possessing antihypertrophic and anti-cell death activity afforded by engagement of the PI3Kα-Akt signaling. CpG-ODNs may have clinical use curbing the progression of PCH and preventing heart failure.

Pharmacological interventions for treating heart failure in patients with chagas cardiomyopathy

BACKGROUND

Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in patients with Chagas disease.

OBJECTIVES

To assess the benefits and harms of current pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) Issue 1, 2011, MEDLINE (Ovid), EMBASE (Ovid), LILACS and ISI Web of Science to April 2011. We checked the reference lists of included papers. No language restrictions were applied.

SELECTION CRITERIA

We included randomized clinical trials assessing the effects of pharmacological interventions for treating heart failure in adult patients (≥18 years) with symptomatic heart failure (New York Heart Association class II to IV), irrespective of the left ventricular ejection fraction stage, reduced or preserved, with Chagas cardiomyopathy. No limits were applied with respect to the follow-up duration. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time to heart decompensation and disease-free period (at 30, 60 and 90 days), and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) and the respective 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data.

MAIN RESULTS

We included two randomized clinical trials involving 69 participants. Both trials compared carvedilol against placebo, and had a high risk of bias. Carvedilol compared with placebo did not significantly affect all-cause mortality (2/34 (5.88%) versus 3/35 (5.87%); pooled RR 0.69, 95% CI 0.12 to 3.88, I(2) = 0%). None of the trials reported on cardiovascular mortality, time to heart decompensation or disease-free period. Evidence on the adverse effects of carvedilol is inconclusive.

AUTHORS' CONCLUSIONS

This Cochrane review has found a lack of evidence on the effects of carvedilol for treating heart failure in patients with Chagas disease. The two included trials were underpowered and had a high risk of bias. There are no conclusive data to support the use of carvedilol for treating Chagas cardiomyopathy. Unless randomized clinical trials provide evidence of a treatment effect, and the trade off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending and administering carvedilol for treating heart failure in patients with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in patients with Chagas disease is unknown.

Cardioprotective effects of 3-phosphoinositide-dependent protein kinase-1 on hypoxic injury in cultured neonatal rat cardiomyocytes and myocardium in a rat myocardial infarct model

3-Phosphoinositide-dependent protein kinase-1 (PDK1) is involved in numerous cellular responses. In this study, we investigated the protective effects of PDK1 gene expression against hypoxic conditions in cultured rat CMCs (rCMCs) and in a rat myocardial infarction (MI) model using the lentiviral vector (LeV) system. LeV-PDK1 transfer effectively reduced the apoptotic cell death caused by hypoxic injury as compared to LeV-GFP transfer in rCMCs the expression of survival proteins increased in the LeV-PDK1 group, whereas apoptosis signaling decreased in the rCMCs and in infarcted hearts treated with LeV-PDK1. LeV-PDK1 transfer also reduced apoptosis and infarct size and attenuated myocardial wall thinning and ventricular remodeling in a rat MI model. These findings suggest that PDK1 has a protective role in the injured ischemic myocardium via overexpression of the cell survival pathway in CMCs. Hence PDK1 can be used as a treatment strategy for myocardial salvage inin hypoxic injury.

An efficient asymmetric synthesis of the potent beta-blocker ICI-118,551 allows the determination of enantiomer dependency on biological activity

A highly efficient, practical and flexible two-step asymmetric synthesis of the beta(2)-selective beta-blocker ICI 118,551 is reported, allowing an unambiguous determination of the dependency of biological activity with optical activity, revealing the S,S-enantiomer to be the most potent.

Deregulation of RGS2 in cardiovascular diseases

Alteration of G protein-coupled receptor (GPCR) signaling is a salient feature of hypertension and the associated heart diseases. Recent studies have revealed a large family of Regulators of G-protein Signaling (RGS) proteins as important endogenous regulators of GPCR signaling. RGS2 selectively regulates Galphaq/11 signaling, an essential cause of hypertension and cardiac hypertrophy. Both clinical and animal studies have shown that deregulation of RGS2 leads to exacerbated Galphaq/11 signaling. There is an inverse correlation between RGS2 expression and blood pressure, as well as a selective down-regulation of RGS2 in various models of cardiac hypertrophy. The causal relationship has been established in animal studies. RGS2 knockout mice exhibit not only hypertension phenotype but also accelerated cardiac hypertrophy and heart failure in response to pressure-overload. Further in vitro studies have shown that RGS2 knockdown with RNA interference exacerbates, whilst RGS2 over-expression completely abolishes the Galphaq/11-induced hypertrophy. These findings indicate that deregulation of RGS2 plays a crucial role in the pathogenesis of cardiovascular diseases, marking RGS2 as a potential therapeutic target or biomarker of hypertension or hypertensive heart diseases.

Future g protein-coupled receptor targets for treatment of heart failure

Heart failure (HF) still poses an enormous clinical challenge, as its incidence, morbidity, and mortality rates are continuously rising. G protein-coupled receptors (GPCRs) constitute the most ubiquitous superfamily of plasma membrane receptors and represent the single most important type of therapeutic drug target. Because there is overstimulation of the failing heart by various endogenous ligands, such as catecholamines and angiotensin II--which by activating their cognate GPCRs in cardiac muscle induce detrimental effects--therapeutic targeting of these receptors has been pursued. This research has led to the development of successful and useful drug classes, such as angiotensin-converting enzyme inhibitors and beta-adrenergic receptor blockers. However, there still is a need to develop innovative treatments that might be more effective at reversing compromised myocyte function. Over the past several years, much evidence has accumulated indicating that a single GPCR, activated by the same endogenous ligand, can elicit several different signaling pathways with quite different, and often opposite, cellular effects. Because the aforementioned ligands, currently used for HF, target these receptors on their extracellular interface, thus merely preventing the endogenous agonists from binding the receptor, they inhibit all the signaling pathways elicited by the receptor indiscriminately. Importantly, several of these pathways emanating from the same GPCR can actually be beneficial for therapy, so their enhancement rather than their blockade is desirable for HF therapy. This highlights the need for selective targeting of GPCR-induced signaling pathways on the intracellular interface of the receptor, which might produce new and innovative therapies for cardiovascular disease.

Digoxin and ouabain induce P-glycoprotein by activating calmodulin kinase II and hypoxia-inducible factor-1alpha in human colon cancer cells

Digoxin and ouabain are cardioactive glycosides, which inhibit the Na+/K+-ATPase pump and in this way they increase the intracellular concentration of cytosolic calcium ([Ca2+](i)). They are also strong inducers of the P-glycoprotein (Pgp), a transmembrane transporter which extrudes several drugs, including anticancer agents like doxorubicin. An increased amount of Pgp limits the absorption of drugs through epithelial cells, thus inducing resistance to chemotherapy. The mechanism by which cardioactive glycosides increase Pgp is not known and in this work we investigated whether digoxin and ouabain elicited the expression of Pgp with a calcium-driven mechanism. In human colon cancer HT29 cells both glycosides increased the [Ca2+](i) and this event was dependent on the calcium influx via the Na+/Ca2+ exchanger. The increased [Ca2+](i) enhanced the activity of the calmodulin kinase II enzyme, which in turn activated the transcription factor hypoxia-inducible factor-1alpha. This one was responsible for the increased expression of Pgp, which actively extruded doxorubicin from the cells and significantly reduced the pro-apoptotic effect of the drug. All the effects of glycosides were prevented by inhibiting the Na+/Ca2+ exchanger or the calmodulin kinase II. This work clarified the molecular mechanisms by which digoxin and oubain induce Pgp and pointed out that the administration of cardioactive glycosides may widely affect the absorption of drugs in colon epithelia. Moreover, our results suggest that the efficacy of chemotherapeutic agent substrates of Pgp may be strongly reduced in patients taking digoxin.

Nebivolol, a vasodilating selective beta(1)-blocker, is a beta(3)-adrenoceptor agonist in the nonfailing transplanted human heart

OBJECTIVES

The present study was to assess whether nebivolol could activate beta(3)-adrenergic receptors (ARs) in the human heart.

BACKGROUND

Nebivolol is a third-generation beta-blocker used in the treatment of heart failure. It associates selective beta(1)-adrenergic antagonist properties with endothelial and nitric oxide (NO)-dependent vasodilation. Several studies reported that this vasodilation could result from an activation of beta(3)-ARs, but no data are available in the heart.

METHODS

The effect of nebivolol (0.1 nmol/l to 10 micromol/l) upon the developed peak tension was tested in endomyocardial biopsies from human nonrejecting transplanted hearts. Tension was recorded at steady state using a mechanoelectric force transducer.

RESULTS

Nebivolol induced a concentration-dependent decrease in peak tension (maximum effect obtained at 10 micromol/l: -55 +/- 4%, n = 6), which was similar to that obtained with a preferential beta(3)-AR agonist, BRL 37344 (maximum effect obtained at 1 micromol/l: -45 +/- 2%, n = 12). The nebivolol effect was not modified by 10 micromol/l nadolol, a beta(1,2)-AR antagonist, but was significantly reduced in the presence of 1 micromol/l L-748,337, a selective beta(3)-AR antagonist, and after pre-treatment with 100 micromol/l N(G)-monomethyl-L-arginine, an NOS inhibitor.

CONCLUSIONS

Our study demonstrated that nebivolol activated beta(3)-AR in the human ventricle. The NO-dependent negative inotropic effect of nebivolol associated with its vasodilating properties previously described in human microcoronary arteries could improve the energetic balance in heart. Those effects could explain the improvement of hemodynamic parameters obtained in patients with heart failure after nebivolol administration as previously described in clinical trials.

The protective effects of exercise and phosphoinositide 3-kinase (p110α) in the failing heart

Despite the development of a wide range of therapies, heart failure remains a leading cause of death in Western society. New therapies are needed to help combat this debilitating condition. Exercise is becoming an increasingly important feature of rehabilitation programmes for patients with heart failure. Before the 1980s, patients with heart failure were advised not to exercise as it was thought that exercise would increase the risk of a cardiac event (such as myocardial infarction). However, in recent years both aerobic and resistance training have been shown to be safe and beneficial for patients with heart failure, improving exercise tolerance and quality of life, and preventing muscular deconditioning. The molecular mechanisms responsible for exercise-induced cardioprotection are yet to be elucidated, however studies in transgenic mice have identified PI3K(p110α) (phosphoinositide 3-kinase p110α) as a likely mediator. PI3K(p110α) is a lipid kinase which is activated in the heart during chronic exercise training, and is important for maintaining heart structure and function in various pathological settings. In the present review the protective effects of PI3K(p110α) in the failing heart and its potential as a therapeutic strategy for the treatment of heart failure is discussed.

Mesenchymal stem cells for the treatment of heart failure

Heart failure is one of the most important cardiovascular health problems throughout the world and has high mortality, and there is a need to develop more effective therapeutic strategies to replace such specialized treatment as mechanical circulatory support and cardiac transplantation. Mesenchymal stem cells (MSC) are multipotent plastic-adherent cells obtained from bone marrow, adipose tissue, and other tissues and can be easily expanded in culture. The ability of MSC to differentiate into a variety of cells, including cardiomyocytes and vascular endothelial cells, make them an attractive therapeutic tool for heart failure. Recent in vitro and in vivo studies have revealed the underlying mechanisms of MSC in cardiac repair. MSC exert their role in cardiac regeneration not only by differentiating into specific cell types such as cardiomyocytes and vascular endothelial cells but also through paracrine effects via secretion of a variety of angiogenic, antiapoptotic, and mitogenic factors. Endogenous MSC as well as exogenously administered MSC have also been suggested to migrate and participate in cardiac repair. On the basis of information obtained from basic and translational research, several clinical trials have recently been started to evaluate the safety and efficacy of autologous MSC for heart failure.

G-protein coupled receptor signaling in myocardium: not for the faint of heart

Catecholamines, endothelin-1 and angiotensin II are among a diverse group of diffusible extracellular signals that regulate pump function of the heart by binding to G-protein coupled receptors (GPCR). When the body demands a temporary boost of power output or if temporary budgeting of resources is required, these signals can adjust heart rate and contractile strength to maintain continuous perfusion of all vascular beds with nutrient- and oxygen-rich blood. Given adequate time in the face of prolonged challenges, activation of GPCRs can also promote "remodeling of the heart" by increasing cell size, organ size, and chamber dimensions, or by varying tissue composition and altering the expression of protein isoforms controlling excitability and contractility. A common feature of heart disease is the state of chronic activation of GPCR signaling systems. Paradoxically, whereas acute activation is beneficial, chronic activation often contributes to further deterioration of cardiac performance. A better understanding of how chronic GPCR activation contributes to the development of heart disease is needed so that it can be translated into better prevention and therapeutic strategies in the clinic.

Prepare cells to repair the heart: mesenchymal stem cells for the treatment of heart failure

Heart failure is one of the most important cardiovascular diseases, with high mortality, and invasive treatment such as mechanical circulatory support and cardiac transplantation is sometimes required for severe heart failure. Therefore, the development of less invasive and more effective therapeutic strategies is desired. Cell therapy is attracting growing interest as a new approach for the treatment of heart failure. As a cell source, various kinds of stem/progenitor cells such as bone marrow cells, endothelial progenitor cells, mesenchymal stem cells (MSC) and cardiac stem cells have been investigated for their efficacy and safety. Especially, bone marrow-derived MSC possess multipotency and can be easily expanded in culture, and are thus an attractive therapeutic tool for heart failure. Recent studies have revealed the underlying mechanisms of MSC in cardiac repair: MSC not only differentiate into specific cell types such as cardiomyocytes and vascular endothelial cells, but also secrete a variety of paracrine angiogenic and cytoprotective factors. It has also been suggested that endogenous MSC as well as exogenously transplanted MSC migrate and participate in cardiac repair. Based on these findings, several clinical trials have just been started to evaluate the safety and efficacy of MSC for the treatment of heart failure.