Doxorubicin-induced and trastuzumab-induced cardiotoxicity in mice is not prevented by metoprolol.

AIMS: Our objectives were to validate a murine model of chronic cardiotoxicity induced by Doxorubicin (Dox) and Trastuzumab (Trast) and to test the potential cardio-protective effect of metoprolol. METHODS AND RESULTS: Male C57Bl6 mice were intraperitoneally injected during 2 weeks with Dox (24 mg/kg) or saline, and then with Trast (10 mg/kg) or saline for two more weeks. Half of the mice received metoprolol (100 mg/kg). Cardiotoxicity was defined by a decline in left ventricular ejection fraction (LVEF) ≥ 10 points. At Day 42, Dox + Trast-treated mice exhibited a 13-points decline in LVEF (74 ± 2.6% vs. 87 ± 0.8% for control mice, P < 0.001) and a severe cardiac atrophy (heart weight: 105 ± 2.7 mg vs. 119 ± 3.9 mg for control mice, P < 0.01). This cardiac atrophy resulted from an excess of cardiac necrosis (assessed by plasma cardiac troponin I level: 3.2 ± 0.4 ng/L vs. 1.3 ± 0.06 ng/L for control mice, P < 0.01), an increase in apoptosis (caspase 3 activity showing a six-fold increase for Dox + Trast-treated mice vs. controls, P < 0.001), and cardiomyocyte atrophy (myocyte size: 0.67 ± 0.08 µm2 vs. 1.36 ± 0.10 µm2 for control mice, P < 0.001). In addition, Dox + Trast-treated mice were shown to have an increased cardiac oxidative stress (164 ± 14 dihydroethidine-marked nuclei per area vs. 56 ± 9.5 for control mice, P < 0.01) and increased cardiac fibrosis (the semi-quantitative fibrosis score was three-fold higher for Dox + Trast-treated mice as compared with controls, P < 0.01). Metoprolol was not able to prevent either the decrease in LVEF or the severe cardiac atrophy, the cardiac necrosis, and the cardiac remodelling induced by chemotherapies. CONCLUSION: A murine model of chronic cardiotoxicity induced by Dox and Trast was characterized by a decrease in cardiac function, a cardiac apoptosis and necrosis leading to cardiomyocyte atrophy. Metoprolol did not prevent this cardiotoxicity.

Inhibition of circulating dipeptidyl-peptidase 3 restores cardiac function in a sepsis-induced model in rats: A proof of concept study.

Sepsis is a global economic and health burden. Dipeptidyl peptidase 3 (DPP3) is elevated in the plasma of septic patients. The highest levels of circulating DPP3 (cDPP3) are found in non-survivor septic shock patients. The aim of this study was to evaluate the benefits of inhibiting cDPP3 by a specific antibody, Procizumab (PCZ), on cardiac function in an experimental model of sepsis, the caecal ligature and puncture (CLP) model. Rats were monitored by invasive blood pressure and echocardiography. Results are presented as mean ± SD, with p <0.05 considered significant. PCZ rapidly restored left ventricular shortening fraction (from 39 ± 4% to 51 ± 2% before and 30 min after PCZ administration (p = 0.004)). Cardiac output and stroke volume were higher in the CLP + PCZ group when compared to the CLP + PBS group (152 ± 33 mL/min vs 97 ± 25 mL/min (p = 0.0079), and 0.5 ± 0.1 mL vs 0.3 ± 1.0 mL (p = 0.009), respectively) with a markedly reduced plasma DPP3 activity (138 ± 70 U/L in CLP + PCZ group versus 735 ± 255 U/L (p = 0.048) in the CLP + PBS group). Of note, PCZ rapidly reduced oxidative stress in the heart of the CLP + PCZ group when compared to those of the CLP + PBS group (13.3 ± 8.2 vs 6.2 ± 2.5 UI, p = 0.005, 120 min after administration, respectively). Our study demonstrates that inhibition of cDPP3 by PCZ restored altered cardiac function during sepsis in rats.

Cardiac Overexpression of PDE4B Blunts ß-Adrenergic Response and Maladaptive Remodeling in Heart Failure.

BACKGROUND: The cyclic AMP (adenosine monophosphate; cAMP)-hydrolyzing protein PDE4B (phosphodiesterase 4B) is a key negative regulator of cardiac ß-adrenergic receptor stimulation. PDE4B deficiency leads to abnormal Ca2+ handling and PDE4B is decreased in pressure overload hypertrophy, suggesting that increasing PDE4B in the heart is beneficial in heart failure. METHODS: We measured PDE4B expression in human cardiac tissues and developed 2 transgenic mouse lines with cardiomyocyte-specific overexpression of PDE4B and an adeno-associated virus serotype 9 encoding PDE4B. Myocardial structure and function were evaluated by echocardiography, ECG, and in Langendorff-perfused hearts. Also, cAMP and PKA (cAMP dependent protein kinase) activity were monitored by Förster resonance energy transfer, L-type Ca2+ current by whole-cell patch-clamp, and cardiomyocyte shortening and Ca2+ transients with an Ionoptix system. Heart failure was induced by 2 weeks infusion of isoproterenol or transverse aortic constriction. Cardiac remodeling was evaluated by serial echocardiography, morphometric analysis, and histology. RESULTS: PDE4B protein was decreased in human failing hearts. The first PDE4B-transgenic mouse line (TG15) had a ≈15-fold increase in cardiac cAMP-PDE activity and a ≈30% decrease in cAMP content and fractional shortening associated with a mild cardiac hypertrophy that resorbed with age. Basal ex vivo myocardial function was unchanged, but ß-adrenergic receptor stimulation of cardiac inotropy, cAMP, PKA, L-type Ca2+ current, Ca2+ transients, and cell contraction were blunted. Endurance capacity and life expectancy were normal. Moreover, these mice were protected from systolic dysfunction, hypertrophy, lung congestion, and fibrosis induced by chronic isoproterenol treatment. In the second PDE4B-transgenic mouse line (TG50), markedly higher PDE4B overexpression, resulting in a ≈50-fold increase in cardiac cAMP-PDE activity caused a ≈50% decrease in fractional shortening, hypertrophy, dilatation, and premature death. In contrast, mice injected with adeno-associated virus serotype 9 encoding PDE4B (1012 viral particles/mouse) had a ≈50% increase in cardiac cAMP-PDE activity, which did not modify basal cardiac function but efficiently prevented systolic dysfunction, apoptosis, and fibrosis, while attenuating hypertrophy induced by chronic isoproterenol infusion. Similarly, adeno-associated virus serotype 9 encoding PDE4B slowed contractile deterioration, attenuated hypertrophy and lung congestion, and prevented apoptosis and fibrotic remodeling in transverse aortic constriction. CONCLUSIONS: Our results indicate that a moderate increase in PDE4B is cardioprotective and suggest that cardiac gene therapy with PDE4B might constitute a new promising approach to treat heart failure.

Acute Kidney Injury Induces Remote Cardiac Damage and Dysfunction Through the Galectin-3 Pathway.

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Synergic PDE3 and PDE4 control intracellular cAMP and cardiac excitation-contraction coupling in a porcine model.

AIMS: Cyclic AMP phosphodiesterases (PDEs) are important modulators of the cardiac response to ß-adrenergic receptor (ß-AR) stimulation. PDE3 is classically considered as the major cardiac PDE in large mammals and human, while PDE4 is preponderant in rodents. However, it remains unclear whether PDE4 also plays a functional role in large mammals. Our purpose was to understand the role of PDE4 in cAMP hydrolysis and excitation-contraction coupling (ECC) in the pig heart, a relevant pre-clinical model. METHODS AND RESULTS: Real-time cAMP variations were measured in isolated adult pig right ventricular myocytes (APVMs) using a Förster resonance energy transfer (FRET) biosensor. ECC was investigated in APVMs loaded with Fura-2 and paced at 1 Hz allowing simultaneous measurement of intracellular Ca2+ and sarcomere shortening. The expression of the different PDE4 subfamilies was assessed by Western blot in pig right ventricles and APVMs. Similarly to PDE3 inhibition with cilostamide (Cil), PDE4 inhibition with Ro 20-1724 (Ro) increased cAMP levels and inotropy under basal conditions. PDE4 inhibition enhanced the effects of the non-selective ß-AR agonist isoprenaline (Iso) and the effects of Cil, and increased spontaneous diastolic Ca2+ waves (SCWs) in these conditions. PDE3A, PDE4A, PDE4B and PDE4D subfamilies are expressed in pig ventricles. In APVMs isolated from a porcine model of repaired tetralogy of Fallot which leads to right ventricular failure, PDE4 inhibition also exerts inotropic and pro-arrhythmic effects. CONCLUSIONS: Our results show that PDE4 controls ECC in APVMs and suggest that PDE4 inhibitors exert inotropic and pro-arrhythmic effects upon PDE3 inhibition or ß-AR stimulation in our pre-clinical model. Thus, PDE4 inhibitors should be used with caution in clinics as they may lead to arrhythmogenic events upon stress.

Adrecizumab, a non-neutralizing anti-adrenomedullin antibody, improves haemodynamics and attenuates myocardial oxidative stress in septic rats.

BACKGROUND: Sepsis still represents a major health issue, with persistent high morbidity and mortality rates. Cardiovascular dysfunction occurs frequently during sepsis. Adrenomedullin has been identified as a key mediator in vascular tone regulation. A non-neutralizing anti-adrenomedullin antibody, Adrecizumab, may improve haemodynamic dysfunction during caecal ligation and puncture-induced septic shock in a murine model. Our objective was to determine the role of Adrecizumab on haemodynamics in a rat model of sepsis. METHODS: For the induction of sepsis, caecal ligation and puncture were performed in Wistar male rats. Single blinded administration of Adrecizumab (2 mg/kg) or placebo was injected i.v. 24 h after the surgery, and norepinephrine was infused as the standard of care. There were > 7 animals per group. Invasive blood pressure and cardiac function (by echocardiography) were assessed until 3 h after Adrecizumab injection. RESULTS: A single therapeutic injection of Adrecizumab in septic rats induced rapid haemodynamic benefits with an increase in systolic blood pressure in septic-Adrecizumab rats versus untreated-septic rats (p = 0.049). The shortening fraction did not differ between the untreated-septic and septic-Adrecizumab groups. However, cardiac output increased during the 3 h after a single dose of Adrecizumab compared to untreated septic rats (p = 0.006). A single dose of Adrecizumab resulted in similar haemodynamics to the continuous administration of norepinephrine. Three hours after a single injection of Adrecizumab, there was no change in the inflammatory phenotype (TNFα, IL-10) in the hearts of the septic rats. By contrast, 3 h after a single Adrecizumab injection, free-radical production decreased in the hearts of septic-Adrecizumab vs untreated septic rats (p < 0.05). CONCLUSIONS: In a rat model of sepsis, a single therapeutic injection of Adrecizumab rapidly restored haemodynamic parameters and blunted myocardial oxidative stress. Currently, a proof-of-concept and dose-finding phase II trial (Adrenoss-2) is ongoing in patients with septic shock and elevated concentrations of circulating bio-adrenomedullin.

QSOX1, a novel actor of cardiac protection upon acute stress in mice.

QSOX1, a sulfhydryl oxidase, was shown to be upregulated in the heart upon acute heart failure (AHF). The aim of the study was to unravel QSOX1 roles during AHF. We generated and characterized mice with QSOX1 gene deletion. The QSOX1-/- mice were viable but adult male exhibited a silent dilated cardiomyopathy. The QSOX1-/- hearts were characterized by low protein SERCA2a levels associated with a calcium homeostasis alteration, high levels of the endoplasmic reticulum (ER) chaperone proteins Grp78/Bip, and of the ER apoptosis sensor CHOP, indicating a chronic unfolded protein response (UPR). Importantly the QSOX1invalidation led to overexpression of two ER oxidases, ERO1-α and PRDX4. Acute stress was induced by isoproterenol injection (ISO, 300 mg/kg/12 h) for 2 days. In both groups, the PERK UPR pathway was transiently activated 6 h after the first ISO injection as indicated by eIF2 phosphorylation. By day-3 after the onset of stress, both WT and QSOX1-/- mice exhibited AHF profile but while high cardiac QSOX1 level was induced in WT hearts, ERO1-α and PRDX4 levels drop down in QSOX1-/-. At that time, QSOX1-/- hearts exhibited an enhanced inflammation (CD68+ cells and Galectin-3 expression) and oxidative stress (DHE staining and oxyblot) when compared to WT ones. In conclusion, the lack of QSOX1 promotes the upregulation of two ER oxidases ERO1α and PRDX4 that likely rescues oxidative protein folding in the hearts. However, signs of chronic ER stress remained present and were associated with a dilated cardiomyopathy. The superimposition of acute stress allowed us to propose that QSOX1 participate to the early response to cardiac stress but not to immediate UPR response. Taken altogether, the data indicated that QSOX1 is required 1) for a proper protein folding in the endo/sarcoplasmic reticulum (ER/SR) and 2) for resolution and protective response during acute stress.

The heart regulates the endocrine response to heart failure: cardiac contribution to circulating neprilysin.

Aims: Heart failure (HF) is accompanied by major neuroendocrine changes including the activation of the natriuretic peptide (NP) pathway. Using the unique model of patients undergoing implantation of the CARMAT total artificial heart and investigating regional differences in soluble neprilysin (sNEP) in patients with reduced or preserved systolic function, we studied the regulation of the NP pathway in HF. Methods and results: Venous blood samples from two patients undergoing replacement of the failing ventricles with a total artificial heart were collected before implantation and weekly thereafter until post-operative week 6. The ventricular removal was associated with an immediate drop in circulating NPs, a nearly total disappearance of circulating glycosylated proBNP and furin activity and a marked decrease in sNEP. From post-operative week 1 onwards, NP concentrations remained overall unchanged. In contrast, partial recoveries in glycosylated proBNP, furin activity, and sNEP were observed. Furthermore, while in patients with preserved systolic function (n = 6), sNEP concentrations in the coronary sinus and systemic vessels were similar (all P > 0.05), in patients with reduced left-ventricular systolic function, sNEP concentration, and activity were ∼three-fold higher in coronary sinus compared to systemic vessels (n = 21, all P < 0.0001), while the trans-pulmonary gradient was neutral (n = 5, P = 1.0). Conclusion: The heart plays a pivotal role as a regulator of the endocrine response in systolic dysfunction, not only by directly releasing NPs but also by contributing to circulating sNEP, which in turn determines the bioavailability of other numerous vasoactive peptides.

Beneficial effects of exercise training in heart failure are lost in male diabetic rats.

Exercise training has been demonstrated to have beneficial effects in patients with heart failure (HF) or diabetes. However, it is unknown whether diabetic patients with HF will benefit from exercise training. Male Wistar rats were fed either a standard (Sham, n = 53) or high-fat, high-sucrose diet ( n = 66) for 6 mo. After 2 mo of diet, the rats were already diabetic. Rats were then randomly subjected to either myocardial infarction by coronary artery ligation (MI) or sham operation. Two months later, heart failure was documented by echocardiography and animals were randomly subjected to exercise training with treadmill for an additional 8 wk or remained sedentary. At the end, rats were euthanized and tissues were assayed by RT-PCR, immunoblotting, spectrophotometry, and immunohistology. MI induced a similar decrease in ejection fraction in diabetic and lean animals but a higher premature mortality in the diabetic group. Exercise for 8 wk resulted in a higher working power developed by MI animals with diabetes and improved glycaemia but not ejection fraction or pathological phenotype. In contrast, exercise improved the ejection fraction and increased adaptive hypertrophy after MI in the lean group. Trained diabetic rats with MI were nevertheless able to develop cardiomyocyte hypertrophy but without angiogenic responses. Exercise improved stress markers and cardiac energy metabolism in lean but not diabetic-MI rats. Hence, following HF, the benefits of exercise training on cardiac function are blunted in diabetic animals. In conclusion, exercise training only improved the myocardial profile of infarcted lean rats fed the standard diet. NEW & NOTEWORTHY Exercise training is beneficial in patients with heart failure (HF) or diabetes. However, less is known of the possible benefit of exercise training for HF patients with diabetes. Using a rat model where both diabetes and MI had been induced, we showed that 2 mo after MI, 8 wk of exercise training failed to improve cardiac function and metabolism in diabetic animals in contrast to lean animals.

Imbalanced Angiogenesis in Peripartum Cardiomyopathy　- Diagnostic Value of Placenta Growth Factor.

BACKGROUND: Concentrations of the anti-angiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1) are altered in peripartum cardiomyopathy (PPCM). In this study we investigated changes in the angiogenesis balance in PPCM.Methods and Results:Plasma concentrations of sFlt-1 and the pro-angiogenic placenta growth factor (PlGF) were determined in patients with PPCM during the post-partum phase (n=83), in healthy women at delivery (n=30), and in patients with acute heart failure (AHF; n=65). Women with cardiac failure prepartum or associated with any form of hypertension, including pre-eclampsia, were excluded. Compared with non-pregnant women, in women with AHF and PPCM, median PlGF concentrations were greater (19 [IQR 16-22] and 98 [IQR 78-126] ng/mL, respectively; P<0.001) and the sFlt-1/PlGF ratio was lower (9.8 [6.6-11.3] and 1.2 [0.9-2.8], respectively; P<0.001). The sFlt-1/PlGF ratio was lower in PPCM than in normal deliveries (1.2 [0.9-2.8] vs. 94.8 [68.8-194.1], respectively; P<0.0001). The area under the curve for PlGF (cut-off value: 50ng/mL) and/or the sFlt-1/PlGF ratio (cut-off value: 4) to distinguish PPCM from either normal delivery or AHF was >0.94. Median plasma concentrations of the anti-angiogenic factor relaxin-2 were lower in PPCM and AHF (0.3 [IQR 0.3-1.7] and 0.3 [IQR 0.3-1] ng/mL, respectively) compared with normal deliveries (1,807 [IQR 1,101-4,050] ng/mL; P<0.001). CONCLUSIONS: Plasma of PPCM patients shows imbalanced angiogenesis. High PlGF and/or low sFlt-1/PlGF may be used to diagnose PPCM.

Soluble CD146 Is a Novel Marker of Systemic Congestion in Heart Failure Patients: An Experimental Mechanistic and Transcardiac Clinical Study.

BACKGROUND: Soluble CD146 (sCD146), is an endothelial marker with similar diagnostic power as natriuretic peptides in decompensated heart failure (HF). While natriuretic peptides are released by the failing heart, sCD146 may be released by veins in response to stretch induced by systemic congestion in HF. This study investigated the source, effects of vascular stress on release and prognostic properties of sCD146 in HF. METHODS: In a peripheral venous stress study, plasma concentrations of sCD146 and N-terminal probrain natriuretic-peptide (NT-proBNP) were measured in 44 HF patients at baseline and after 90 min of unilateral forearm venous congestion. In addition, sCD146 and NT-proBNP were measured in peripheral vein (PV) and coronary sinus (CS) blood samples of 137 HF patients and the transcardiac gradient was calculated. Those patients were followed for major adverse cardiovascular events (MACE) during 2 years. RESULTS: The induction of venous stress was associated with a pronounced increase in circulating concentrations of sCD146 in the congested arm (+60 µg/L) compared to the control arm (+16 µg/L, P = 0.025), while no difference in NT-proBNP concentrations was seen. In contrast to positive transcardiac gradient for NT-proBNP, median sCD146 concentrations were lower in CS than in PV (396 vs 434, P < 0.001), indicating a predominantly extracardiac source of sCD146. Finally, increased PV concentrations of sCD146 were associated with higher risk of MACE at 2 years. CONCLUSIONS: Soluble CD146 is released from the peripheral vasculature in response to venous stretch and may reflect systemic congestion in chronic HF patients.

SIRT1 protects the heart from ER stress-induced cell death through eIF2α deacetylation.

Over the past decade, endoplasmic reticulum (ER) stress has emerged as an important mechanism involved in the pathogenesis of cardiovascular diseases including heart failure. Cardiac therapy based on ER stress modulation is viewed as a promising avenue toward effective therapies for the diseased heart. Here, we tested whether sirtuin-1 (SIRT1), a NAD+-dependent deacetylase, participates in modulating ER stress response in the heart. Using cardiomyocytes and adult-inducible SIRT1 knockout mice, we demonstrate that SIRT1 inhibition or deficiency increases ER stress-induced cardiac injury, whereas activation of SIRT1 by the SIRT1-activating compound STAC-3 is protective. Analysis of the expression of markers of the three main branches of the unfolded protein response (i.e., PERK/eIF2α, ATF6 and IRE1) showed that SIRT1 protects cardiomyocytes from ER stress-induced apoptosis by attenuating PERK/eIF2α pathway activation. We also present evidence that SIRT1 physically interacts with and deacetylates eIF2α. Mass spectrometry analysis identified lysines K141 and K143 as the acetylation sites on eIF2α targeted by SIRT1. Furthermore, mutation of K143 to arginine to mimic eIF2α deacetylation confers protection against ER stress-induced apoptosis. Collectively, our findings indicate that eIF2α deacetylation on lysine K143 by SIRT1 is a novel regulatory mechanism for protecting cardiac cells from ER stress and suggest that activation of SIRT1 has potential as a therapeutic approach to protect the heart against ER stress-induced injury.

Loss of Notch3 Signaling in Vascular Smooth Muscle Cells Promotes Severe Heart Failure Upon Hypertension.

Hypertension, which is a risk factor of heart failure, provokes adaptive changes at the vasculature and cardiac levels. Notch3 signaling plays an important role in resistance arteries by controlling the maturation of vascular smooth muscle cells. Notch3 deletion is protective in pulmonary hypertension while deleterious in arterial hypertension. Although this latter phenotype was attributed to renal and cardiac alterations, the underlying mechanisms remained unknown. To investigate the role of Notch3 signaling in the cardiac adaptation to hypertension, we used mice with either constitutive Notch3 or smooth muscle cell-specific conditional RBPJκ knockout. At baseline, both genotypes exhibited a cardiac arteriolar rarefaction associated with oxidative stress. In response to angiotensin II-induced hypertension, the heart of Notch3 knockout and SM-RBPJκ knockout mice did not adapt to pressure overload and developed heart failure, which could lead to an early and fatal acute decompensation of heart failure. This cardiac maladaptation was characterized by an absence of media hypertrophy of the media arteries, the transition of smooth muscle cells toward a synthetic phenotype, and an alteration of angiogenic pathways. A subset of mice exhibited an early fatal acute decompensated heart failure, in which the same alterations were observed, although in a more rapid timeframe. Altogether, these observations indicate that Notch3 plays a major role in coronary adaptation to pressure overload. These data also show that the hypertrophy of coronary arterial media on pressure overload is mandatory to initially maintain a normal cardiac function and is regulated by the Notch3/RBPJκ pathway.

Inhibition of Galectin-3 Pathway Prevents Isoproterenol-Induced Left Ventricular Dysfunction and Fibrosis in Mice.

Galectin-3 (Gal-3) is involved in inflammation, fibrogenesis, and cardiac remodeling. Previous evidence shows that Gal-3 interacts with aldosterone in promoting macrophage infiltration and vascular fibrosis and that Gal-3 genetic and pharmacological inhibition prevents remodeling in a pressure-overload animal model of heart failure. We aimed to explore the contribution of Gal-3 and aldosterone in mechanisms leading to heart failure in a murine model. Male mice with cardiac-specific hyperaldosteronism underwent isoproterenol subcutaneous injections, to be then randomized to receive placebo, a Gal-3 inhibitor (modified citrus pectin [MCP]), an aldosterone antagonist (potassium canrenoate), or MCP+canrenoate for 14 days. Isoproterenol induced a rapid and persistent decrease in left ventricular fractional shortening (-20% at day 14); this was markedly improved by treatment with either MCP or canrenoate (both P<0.001 versus placebo). MCP and canrenoate also reduced cardiac hypertrophy and fibrosis and the expression of genes involved in fibrogenesis (Coll-1 and Coll-3) and macrophage infiltration (CD-68 and MCP-1). After isoproterenol, Gal-3 gene expression (P<0.05 versus placebo) and protein levels (-61% and -69% versus placebo) were decreased by both canrenoate and MCP. The combined use of antagonists of Gal-3 and aldosterone resulted in more pronounced effects on cardiac hypertrophy, inflammation, and fibrosis, when compared with either MCP or canrenoate alone. Inhibition of Gal-3 and aldosterone can reverse isoproterenol-induced left ventricular dysfunction, by reducing myocardial inflammation and fibrogenesis. Gal-3 likely participates in mechanisms of aldosterone-mediated myocardial damage in a heart failure murine model with cardiac hyperaldosteronism. Gal-3 inhibition may represent a new promising therapeutic option in heart failure.

Circulating microRNAs and Outcome in Patients with Acute Heart Failure.

BACKGROUND: The biomarker value of circulating microRNAs (miRNAs) has been extensively addressed in patients with acute coronary syndrome. However, prognostic performances of miRNAs in patients with acute heart failure (AHF) has received less attention. METHODS: A test cohort of 294 patients with acute dyspnea (236 AHF and 58 non-AHF) and 44 patients with stable chronic heart failure (CHF), and an independent validation cohort of 711 AHF patients, were used. Admission levels of miR-1/-21/-23/-126/-423-5p were assessed in plasma samples. RESULTS: In the test cohort, admission levels of miR-1 were lower in AHF and stable CHF patients compared to non-AHF patients (p = 0.0016). Levels of miR-126 and miR-423-5p were lower in AHF and in non-AHF patients compared to stable CHF patients (both p<0.001). Interestingly, admission levels of miR-423-5p were lower in patients who were re-admitted to the hospital in the year following the index hospitalization compared to patients who were not (p = 0.0001). Adjusted odds ratio [95% confidence interval] for one-year readmission was 0.70 [0.53-0.93] for miR-423-5p (p = 0.01). In the validation cohort, admission levels of miR-423-5p predicted 1-year mortality with an adjusted odds ratio [95% confidence interval] of 0.54 [0.36-0.82], p = 0.004. Patients within the lowest quartile of miR-423-5p were at high risk of long-term mortality (p = 0.02). CONCLUSIONS: In AHF patients, low circulating levels of miR-423-5p at presentation are associated with a poor long-term outcome. This study supports the value of miR-423-5p as a prognostic biomarker of AHF.

Elevated Plasma B-Type Natriuretic Peptide Concentrations Directly Inhibit Circulating Neprilysin Activity in Heart Failure.

OBJECTIVES: This study sought to hypothesize that elevated B-type natriuretic peptide (BNP) could act as an endogenous neprilysin inhibitor. BACKGROUND: A hallmark of acute decompensated heart failure (ADHF) is the overproduction of natriuretic peptides (NPs) by stretched cardiomyocytes. Various strategies have been developed to potentiate the beneficial effect of the NPs, including the recent use of neprilysin angiotensin receptor inhibitors. Contrary to rodents, human BNP is poorly sensitive to neprilysin degradation while retaining affinity to neprilysin. METHODS: We enrolled 638 patients presenting to the emergency department with acute dyspnea of which 468 had ADHF and 169 had dyspnea of noncardiac origin. We also included 46 patients with stable chronic heart failure (HF) and 10 age-matched healthy subjects. Plasma samples were collected within 4 h after emergency department admission. BNP, neprilysin concentration and activity, and the neprilysin substrate substance P concentration were measured. RESULTS: We found that when plasma BNP rose above 916 pg/ml, neprilysin activity was markedly reduced (p < 0.0001) and stratified 95% of the population into 2 groups: BNP <916 pg/ml/neprilysin activity ≥ 0.21 nmol/ml/min and BNP ≥916 pg/ml/neprilysin activity <0.21 nmol/ml/min with very different prognoses. In vitro, BNP was responsible for neprilysin inhibition. Neprilysin activity was inversely correlated with the concentration of substance P (ρ = -0.80; p < 0.0001). CONCLUSIONS: Besides being an effector of the cardiac response to cardiomyocyte stretching in ADHF, elevated plasma BNP is also an endogenous neprilysin inhibitor. A biologically relevant BNP threshold discriminates 2 populations of HF patients with different vasoactive peptide profiles and outcome. If confirmed, this may identify an important threshold for managing HF patients.

Soluble CD146, a new endothelial biomarker of acutely decompensated heart failure.

BACKGROUND: The present study involved both human cohorts and animal experiments to explore the performance of soluble CD146 (sCD146), a marker of endothelial function, as a diagnostic marker of acutely decompensated heart failure (ADHF), to determine the influence of patients' characteristics on that performance and to explore the potential application of CD146 in the pathophysiology of ADHF. METHODS AND RESULTS: NT-proBNP and sCD146 were measured in three hundred ninety-one patients admitted to the emergency department for acute dyspnea. ROC curve analysis demonstrated that AUCs for ADHF diagnosis in dyspneic patients were 0.86 (95% CI: 0.82-0.90) for sCD146 and 0.90 (95% CI: 0.86-0.92) for NT-proBNP. Subgroup analyses demonstrated that adding sCD146 to NT-proBNP improved the diagnostic performance for patients lying in the gray zone of NT-proBNP (p=0.02) and could be especially useful for ruling-out ADHF. An experimental model of ADHF in rats using thoracic aortic constriction suggests that CD146 is expressed in the intima of large arteries and associated with both left ventricular function and organ congestion. CONCLUSIONS: sCD146, a marker of endothelial function, seems to be as powerful as NT-proBNP is used to detect the cardiac origin of an acute dyspnea. The combination of sCD146 and NT-proBNP may have better performance than NT-proBNP used alone in particular for patients underlying in the "gray" zone and could therefore be an improved option for ruling-out ADHF. Both experimental and human data suggest that CD146 is related to systolic left ventricular function and to organ congestion.

Post-translational modifications enhance NT-proBNP and BNP production in acute decompensated heart failure.

BACKGROUND: Increases in plasma B-type natriuretic peptide (BNP) concentrations in those with acutely decompensated heart failure (ADHF) has been mainly attributed to an increase in NPPB gene transcription. Recently, proBNP glycosylation has emerged as a potential regulatory mechanism in the production of amino-terminal (NT)-proBNP and BNP. The aim of the present study was to investigate proBNP glycosylation, and corin and furin activities in ADHF patients. METHODS AND RESULTS: Plasma levels of proBNP, NT-proBNP, BNP, as well as corin and furin concentration and activity were measured in a large cohort of 683 patients presenting with ADHF (n = 468), non-cardiac dyspnoea (non-ADHF: n = 169) and 46 patients with stable chronic heart failure (CHF); the degree of plasma proBNP glycosylation was assessed in a subset of these patients (ADHF: n = 49, non-ADHF: n = 50, CHF: n = 46). Our results showed a decrease in proBNP glycosylation in ADHF patients that paralleled NT-proBNP overproduction (ρ = -0.62, P < 0.001) but less so to BNP. In addition, we observed an increase in furin activity that is positively related to the plasma levels of proBNP, NT-proBNP and BNP overproduction (all P < 0.001, all ρ > 0.88), and negatively related to the degree of proBNP glycosylation (ρ = -0.62, P < 0.001). CONCLUSION: These comprehensive results provide a paradigm for the post-translational modification of natriuretic peptides in ADHF: as proBNP glycosylation decreases, furin activity increases. This synergistically amplifies the processing of proBNP into BNP and NT-proBNP. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/. Identifier: NCT01374880.

Akt-mediated cardioprotective effects of aldosterone in type 2 diabetic mice.

Studies have shown that aldosterone would have angiogenic effects and therefore would be beneficial in the context of cardiovascular diseases. We thus investigated the potential involvement of aldosterone in triggering a cardiac angiogenic response in the context of type-2 diabetes and the molecular pathways involved. Male 3-wk-old aldosterone synthase (AS)-overexpressing mice and their control wild-type (WT) littermates were fed a standard or high-fat, high-sucrose (HFHS) diet. After 6 mo of diet treatment, mice were euthanized, and cardiac samples were assayed by RT-PCR, immunoblotting, and immunohistology. HFHS diet induced type-2 diabetes in WT (WT-D) and AS (AS-D) mice. VEGFa mRNAs decreased in WT-D (-43%, P<0.05 vs. WT) and increased in AS-D mice (+236%, P< 0.01 vs. WT-D). In WT-D mouse hearts, the proapoptotic p38MAPK was activated (P<0.05 vs. WT and AS-D), whereas Akt activity decreased (-64%, P<0.05 vs. WT). The AS mice, which exhibited a cardiac up-regulation of IGF1-R, showed an increase in Akt phosphorylation when diabetes was induced (P<0.05 vs. WT and AS-D). Contrary to WT-D mice, AS-D mouse hearts did not express inflammatory markers and exhibited a normal capillary density (P<0.05 vs. WT-D). To our knowledge, this is the first study providing new insights into the mechanisms whereby aldosterone prevents diabetes-induced cardiac disorders.

Effects of biological sex on the pathophysiology of the heart.

Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches.