0307 : QSOX1 has a protective role in the myocardium face to acute stress

IntroductionQSOX1 was identified as a plasma biomarker of acute heart failure (AHF). QSOX1 being a sulfhydryl oxidase, our aim was to decipher the role of QSOX1 in the heart face to an AHF event.MethodsAHF was provoked by IP injections of Isoproterenol (ISO, 300mg/kg/12h) for 2 days in mice (C57Bl/6 J) whereas control (C) received NaCl 9‰. Mice were killed at day 3, after echocardiography. QSOX1 KO (C57Bl/6 J) mice were generated using a QSOX1tm1a embryonic stem cell clone (KOMP). The KO construct contains a promoter-less lacZ gene under the control of the QSOX1 regulatory sequences. The mRNA levels were analyzed by RT-qPCR. The cellular level of oxidative stress was detected by using DHE. Fibrosis was analysed by Sirius red and collagen mRNA.ResultsAt baseline QSOX1-/- adult mice did not display any cardiac or vascular phenotype. After ISO, lacZ expression dramatically increased in QSOX1+/- hearts with the strongest β-galactosidase staining in the atria. In mice receiving ISO, a pulmonary congestion, BNP (x2 p<0.001) and CD68 (x3, p<0.001) increases were observed only in QSOX1-/-, whereas Galectin 3 increased in both groups. After ISO, the severe cardiac dysfunction in QSOX1-/- mice was associated with signs of enhanced oxidative stress (DHE staining p<0.0001). An early fibrosis was observed by Sirius red analysis and associated with an increase of collagen 1 and 3 mRNAs without difference between WT and QSOX1-/- mice.ConclusionWe provided evidence that the absence of QSOX1 leads to a more serious cardiac dysfunction in response to acute cardiac stress by ISO than in WT counterparts. Hence, our data indicated that QSOX1 protects the heart in response to acute stress

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

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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

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

International audienceAims 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 μm 2 vs. 1.36 ± 0.10 μm 2 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 threefold 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

Soluble CD146 and B-type natriuretic peptide dissect overhydration into functional components of prognostic relevance in haemodialysis patients

Background Accurate volume status evaluation and differentiation of cardiac and non-cardiac components of overhydration (OH) are fundaments of optimal haemodialysis (HD) management. Methods This study, by combining bioimpedance measurements, cardiovascular biomarkers and echocardiography, aimed at dissecting OH into its major functional components, and prospectively tested the association between cardiac and non-cardiac components of OH with mortality. In the first part, we validated soluble CD146 (sCD146) as a non-cardiac biomarker of systemic congestion in a cohort of 30 HD patients. In the second part, we performed a prospective 1-year follow-up study in an independent cohort of 144 HD patients. Results sCD146 incrementally increased after the short and long intervals after HD (+53 ng/mL, P = 0.006 and  +91 ng/mL, P < 0.001), correlated with OH as determined by bioimpedance and well-diagnosed OH (area under the receiver operating characteristics curve 0.72, P = 0.005). The prevalence of OH was lower for low-sCD146 and low-BNP patients (B-type natriuretic peptide, 29%) compared with subjects with either one or both biomarkers elevated (65-74%, P < 0.001). Notably, most low-BNP but high-sCD146 subjects were overhydrated. Systolic dysfunction was 2- to 3-fold more prevalent among high-BNP compared with low-BNP patients (44-68% versus 21-23%, chi-square P < 0.001), regardless of sCD146. One-year all-cause mortality was markedly higher in patients with high-BNP (P = 0.001) but not with high-sCD146. In multivariate analysis, systolic dysfunction and BNP, but not OH, were associated with lower survival. Conclusions The combination of BNP and sCD146 dissects OH into functional components of prognostic value. OH in HD patients is associated with higher mortality only if resulting from cardiac dysfunction

Effects of sacubitril/valsartan on neprilysin targets and the metabolism of natriuretic peptides in chronic heart failure: a mechanistic clinical study

AIM This study aimed at evaluating the effects of sacubitril/valsartan on neprilysin (NEP), and the metabolism of natriuretic peptides in heart failure (HF) and providing additional mechanistic information on the mode of action of the drug. METHODS AND RESULTS We enrolled 73 chronic HF patients who were switched from angiotensin-converting enzyme inhibitor or angiotensin receptor blocker to sacubitril/valsartan. In addition to clinical and echocardiographic assessment, plasma biomarkers were measured at baseline, day 30 and day 90 after initiation of treatment. Sacubitril/valsartan led to decrease in New York Heart Association class and improvement of echocardiographic parameters, as well as a dose-dependent decrease in soluble NEP (sNEP) activity, while sNEP concentration remained unchanged. Neprilysin inhibition translated into an increase in its substrates such as atrial natriuretic peptide (ANP), substance P, and glucagon-like peptide 1, the latter translating into a decrease in fructosamine. Cardiac troponin and soluble ST2 levels, biomarkers of HF severity unrelated to NEP metabolism also decreased. While there was a ∼4-fold increase in ANP, we observed no change in plasma brain natriuretic peptide (BNP) and plasma BNP activity, and a mild decrease in N-terminal proBNP (NT-proBNP) concentrations. Finally, we found a progressive increase in the relationship between BNP and NT-proBNP, which strongly correlated with an increase in T71 proBNP glycosylation (R = 0.94). CONCLUSION Sacubitril/valsartan rapidly and strongly reduced sNEP activity, leading to an increase in levels of NEP substrates. These data suggest a pleiotropic favourable impact of sacubitril/valsartan on the metabolism of HF patients with ANP rather than BNP as major effectors amongst natriuretic peptides

proANP Metabolism Provides New Insights Into Sacubitril/Valsartan Mode of Action

International audienceBACKGROUND: Sacubitril/valsartan (S/V) treatment is beneficial in patients with heart failure with reduced ejection fraction (HFrEF), but its mode of action remains elusive, although it involves the increase in ANP (atrial natriuretic peptide). METHODS: Combining mass spectrometry and enzymatic assay in the plasma of 73 HFrEF patients treated with S/V and controls, we deciphered proANP processing that converts proANP into 4 vasoactive peptides. RESULTS: We found that proANP processing is sequential and involved meprin B, ECE (endothelin-converting enzyme) 1, and ANPEP (aminopeptidase N). This processing is limited in HFrEF patients via the downregulation of proANP production, corin, and meprin B activities by miR-425 and miR1-3p. S/V restored or compensated proANP processing by downregulating miR-425 and miR1-3p, hence increasing levels of proANP-derived bioactive peptides. In contrast, S/V directly and indirectly partially inhibited ECE1 and ANPEP. ECE1 partial inhibition resulted in a lower-than-expected increase in ET1 (endothelin 1), tilting the vasoactive balance toward vasodilation, and possibly hypotension. Furthermore, proANP glycosylation interferes with the midregional proANP assay-a clinical surrogate for proANP production, preventing any pathophysiological interpretation of the results. The analysis of S/V dose escalation with respect to baseline treatments suggests S/V-specific effects. CONCLUSIONS: These findings offer mechanistic evidence to the natriuretic peptide-defective state in HFrEF, which is improved by S/V. These data also strongly suggests that S/V increases plasma ANP by multiple mechanisms that involve 2 microRNAs, besides its protection from NEP (neprilysin) cleavage. Altogether, these data provide new insights on HFrEF pathophysiology and the mode of action of S/V

Plasma Levels of Soluble CD146 Reflect the Severity of Pulmonary Congestion Better Than Brain Natriuretic Peptide in Acute Coronary Syndrome

BACKGROUND: Acute heart failure negatively affects short-term outcomes of patients with acute coronary syndrome (ACS). Therefore, reliable and non-invasive assessment of pulmonary congestion is needed to select patients requiring more intensive monitoring and therapy. Since plasma levels of natriuretic peptides are influenced by myocardial ischemia, they might not reliably reflect congestion in the context of ACS. The novel endothelial biomarker, soluble CD146 (sCD146), presents discriminative power for detecting the cardiac origin of acute dyspnea similar to that of natriuretic peptides and is associated with systemic congestion. We evaluated the performance of sCD146 for the assessment of pulmonary congestion in the early phase of ACS. METHODS: One thousand twenty-one consecutive patients with ACS were prospectively enrolled. Plasma levels of sCD146, brain natriuretic peptide (BNP), and high-sensitive troponin T were measured within 24 hr after the onset of chest pain. Pulmonary congestion on chest radiography was determined and classified in three groups according to the degree of congestion. RESULTS: Nine hundred twenty-seven patients with ACS were analyzed. Ninety-two (10%) patients showed signs of pulmonary edema on chest radiography. Plasma levels of sCD146 reflected the radiological severity of pulmonary congestion. Higher plasma levels of sCD146 were associated with the worse degree of pulmonary congestion. In contrast to BNP, sCD146 levels were not affected by the level of troponin T. CONCLUSIONS: The novel endothelial biomarker, sCD146, correlates with radiological severity of pulmonary congestion in the early phase of ACS and, in contrast to BNP, is not affected by the amount of myocardial cell necrosis

Vascular endothelial growth factor D is a biomarker of fluid overload in haemodialysis patients

BACKGROUND Improved understanding and assessment of the complex physiology of volume regulation in haemodialysis (HD) patients are required to improve patient care and reduce mortality associated with fluid overload (FO). METHODS We searched for FO-related biomarkers among 184 peptides associated with cardiovascular disease in a cohort of 30 HD patients. First, we assessed the direct impact of HD on the peptides of interest by comparing plasma concentrations before and after treatment. Then, we compared cardiovascular peptide profiles between patients with and without FO as defined by bioimpedance analysis (BIA). The plasma concentration of selected candidate biomarkers for FO was determined by enzyme-linked immunosorbent assay (ELISA) and correlated with previously described FO-related clinical and laboratory parameters. For validation, results were confirmed in an independent cohort of 144 HD patients. RESULTS We found seven peptides positively [NT-proBNP, B-type natriuretic peptide (BNP), vascular endothelial growth factor D (VEGFD), tumour necrosis factor-related apoptosis-inducing ligand receptor 2, growth differentiation factor 15, tumour necrosis factor ligand superfamily member 13B, chitinase-3-like protein 1] and five negatively (leptin, renin, epidermal growth factor receptor, interleukin-1 receptor antagonist, myeloblastin) correlated to FO. In addition to natriuretic peptides, VEGFD emerged as third peptide highly correlated with BIA (ρ = 0.619, P < 0.0001). In line with this, VEGFD concentration verified by ELISA correlated with BIA, BNP and soluble CD146 but not with vascular endothelial growth factor C (VEGFC). Notably, levels of VEGFD were unrelated to cardiac systolic function (P = 0.63), contrary to BNP (P = 0.0003). Finally, we observed that 1-year all-cause mortality was higher in patients with high BNP (P = 0.0002), FO (defined by BIA, P = 0.04) and high VEGFD (P = 0.02), but not with high VEGFC (P = 0.48). CONCLUSION VEGFD is a novel FO-related biomarker with unique diagnostic and prognostic properties

Role of cardiovascular biomarkers for the assessment of mitral stenosis and its complications

Background: Mitral stenosis (MS) may cause progressive dyspnea on exertion, pulmonary hypertension (PH), atrial fibrillation and right ventricular (RV) failure. Patients with MS presenting with change in dyspnea severity often require a complete cardiologic assessment, but the use of biomarkers may be an alternative for the initial assessment of MS and its complications. The aim of this study was to evaluate the role of several cardiovascular biomarkers for this purpose