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2.
Int J Mol Sci ; 20(9)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052336

RESUMO

BACKGROUND AND AIM: Systemic lupus erythematosus (SLE) is associated with increased risk of cardiovascular disease (CVD). Among many mechanisms, accelerated atherosclerosis, endothelial dysfunction, and hypercoagulability play a main role. Here, we investigate whether inflammatory, serological and clinical markers of SLE determine and correlate with arterial stiffness in SLE patients. MATERIALS AND METHODS: Routine blood samples, inflammatory mediators, specific antibodies, and 24 h proteinuria were measured in 43 SLE patients and 43 age and sex-matched controls using routine laboratory assays. We also assessed arterial stiffness by measuring radial artery applanation tonometry-derived augmentation index (AI), normalized AI (AIx@75), aortic pulse pressure, central systolic, diastolic and peripheral blood pressure. RESULTS: SLE patients showed a significantly greater arterial stiffness vs. controls, as demonstrated by the significantly higher AIx@75 and aortic pulse pressure. Interestingly, regression analysis showed that age, systolic pulse pressure, inflammatory markers (erythrocyte sedimentation rate and C-reactive protein), daily dose of glucocorticoids, and cumulative organ damage positively correlated with arterial stiffness. CONCLUSIONS: SLE patients show increased arterial stiffness which correlates with markers of inflammation, that is involved in early alterations in arterial walls. Applanation tonometry can be used to screen SLE patients for subclinical vascular damage to implement prevention strategies for CVD.


Assuntos
Doenças Cardiovasculares/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Rigidez Vascular , Adulto , Biomarcadores/sangue , Pressão Sanguínea , Sedimentação Sanguínea , Proteína C-Reativa/análise , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Eur Heart J ; 40(26): 2155-2163, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30957868

RESUMO

Randomized clinical trials initially used heart failure (HF) patients with low left ventricular ejection fraction (LVEF) to select study populations with high risk to enhance statistical power. However, this use of LVEF in clinical trials has led to oversimplification of the scientific view of a complex syndrome. Descriptive terms such as 'HFrEF' (HF with reduced LVEF), 'HFpEF' (HF with preserved LVEF), and more recently 'HFmrEF' (HF with mid-range LVEF), assigned on arbitrary LVEF cut-off points, have gradually arisen as separate diseases, implying distinct pathophysiologies. In this article, based on pathophysiological reasoning, we challenge the paradigm of classifying HF according to LVEF. Instead, we propose that HF is a heterogeneous syndrome in which disease progression is associated with a dynamic evolution of functional and structural changes leading to unique disease trajectories creating a spectrum of phenotypes with overlapping and distinct characteristics. Moreover, we argue that by recognizing the spectral nature of the disease a novel stratification will arise from new technologies and scientific insights that will shape the design of future trials based on deeper understanding beyond the LVEF construct alone.

4.
J Gen Physiol ; 151(6): 758-770, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-30842219

RESUMO

Nitroxyl (HNO) positively modulates myocardial function by accelerating Ca2+ reuptake into the sarcoplasmic reticulum (SR). HNO-induced enhancement of myocardial Ca2+ cycling and function is due to the modification of cysteines in the transmembrane domain of phospholamban (PLN), which results in activation of SR Ca2+-ATPase (SERCA2a) by functionally uncoupling PLN from SERCA2a. However, which cysteines are modified by HNO, and whether HNO induces reversible disulfides or single cysteine sulfinamides (RS(O)NH2) that are less easily reversed by reductants, remain to be determined. Using an 15N-edited NMR method for sulfinamide detection, we first demonstrate that Cys46 and Cys41 are the main targets of HNO reactivity with PLN. Supporting this conclusion, mutation of PLN cysteines 46 and 41 to alanine reduces the HNO-induced enhancement of SERCA2a activity. Treatment of WT-PLN with HNO leads to sulfinamide formation when the HNO donor is in excess, whereas disulfide formation is expected to dominate when the HNO/thiol stoichiometry approaches a 1:1 ratio that is more similar to that anticipated in vivo under normal, physiological conditions. Thus, 15N-edited NMR spectroscopy detects redox changes on thiols that are unique to HNO, greatly advancing the ability to detect HNO footprints in biological systems, while further differentiating HNO-induced post-translational modifications from those imparted by other reactive nitrogen or oxygen species. The present study confirms the potential of HNO as a signaling molecule in the cardiovascular system.

5.
Eur J Heart Fail ; 21(4): 519-528, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30843309

RESUMO

AIMS: Butyric acid (BUT), a short chain fatty acid produced daily by the gut microbiota, has proven beneficial in models of cardiovascular diseases. With advancements in cancer survival, an increasing number of patients are at risk of anticancer drug cardiotoxicity. Here we assess whether the novel BUT derivative phenylalanine-butyramide (FBA) protects from doxorubicin (DOXO) cardiotoxicity, by decreasing oxidative stress and improving mitochondrial function. METHODS AND RESULTS: In C57BL6 mice, DOXO produced left ventricular dilatation assessed by echocardiography. FBA prevented left ventricular dilatation, fibrosis and cardiomyocyte apoptosis when co-administered with DOXO. DOXO increased atrial natriuretic peptide, brain natriuretic peptide, connective tissue growth factor, and matrix metalloproteinase-2 mRNAs, which were not elevated on co-treatment with FBA. DOXO, but not FBA + DOXO mice, also showed higher nitrotyrosine levels, and increased inducible nitric oxide synthase expression. Accordingly, DOXO hearts showed lower levels of intracellular catalase vs. sham, while pre-treatment with FBA prevented this decrease. We then assessed for reactive oxygen species (ROS) emission: DOXO induced increased activity of mitochondrial superoxide dismutase and higher production of H2 O2 , which were blunted by FBA pre-treatment. FBA also ameliorated mitochondrial state 3 and state 4 respiration rates that were compromised by DOXO. Furthermore, in DOXO animals, the mitochondrial degree of coupling was significantly increased vs. sham, while FBA was able to prevent such increase, contributing to limit ROS production, Finally, FBA reduced DOXO damage in human cellular models, and increased the tumour-killing action of DOXO. CONCLUSIONS: Phenylalanine-butyramide protects against experimental doxorubicin cardiotoxicity. Such protection is accompanied by reduction in oxidative stress and amelioration of mitochondrial function.

6.
J Immunother Cancer ; 7(1): 53, 2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30795818

RESUMO

BACKGROUND: Influenza vaccination (FV) is recommended for patients with cancer. Recent data suggested that the administration of the FV was associated with an increase in immune-related adverse events (irAEs) among patients on immune checkpoint inhibitors (ICIs). Myocarditis is an uncommon but serious complication of ICIs and may also result from infection with influenza. There are no data testing the relationship between FV and the development of myocarditis on ICIs. METHODS: Patients on ICIs who developed myocarditis (n = 101) (cases) were compared to ICI-treated patients (n = 201) without myocarditis (controls). A patient was defined as having the FV if they were administered the FV from 6 months prior to start of ICI to anytime during ICI therapy. Alternate thresholds for FV status were also tested. The primary comparison of interest was the rate of FV between cases and controls. Patients with myocarditis were followed for major adverse cardiac events (MACE), defined as the composite of cardiogenic shock, cardiac arrest, hemodynamically significant complete heart block and cardiovascular death. RESULTS: The FV was administered to 25% of the myocarditis cases compared to 40% of the non-myocarditis ICI-treated controls (p = 0.01). Similar findings of lower rates of FV administration were noted among myocarditis cases when alternate thresholds were tested. Among the myocarditis cases, those who were vaccinated had 3-fold lower troponin levels when compared to unvaccinated cases (FV vs. No FV: 0.12 [0.02, 0.47] vs. 0.40 [0.11, 1.26] ng/ml, p = 0.02). Within myocarditis cases, those administered the FV also had a lower rate of other irAEs when compared to unvaccinated cases (36 vs. 55% p = 0.10) including lower rates of pneumonitis (12 vs. 36%, p = 0.03). During follow-up (175 [IQR 89, 363] days), 47% of myocarditis cases experienced a MACE. Myocarditis cases who received the FV were at a lower risk of cumulative MACE when compared to unvaccinated cases (24 vs. 59%, p = 0.002). CONCLUSION: The rate of FV among ICI-related myocarditis cases was lower than controls on ICIs who did not develop myocarditis. In those who developed myocarditis related to an ICI, there was less myocardial injury and a lower risk of MACE among those who were administered the FV.

7.
Cardiovasc Res ; 115(5): 854-868, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30715219

RESUMO

Cardiovascular toxicities associated with immune checkpoint inhibitors (ICIs) have been reported in case series but have been underappreciated due to their recent emergence, difficulties in diagnosis and non-specific clinical manifestations. ICIs are antibodies that block negative regulators of the T cell immune response, including cytotoxic T lymphocyte-associated protein-4 (CTLA-4), programmed cell death protein-1 (PD-1), and PD-1 ligand (PD-L1). While ICIs have introduced a significant mortality benefit in several cancer types, the augmented immune response has led to a range of immune-related toxicities, including cardiovascular toxicity. ICI-associated myocarditis often presents with arrhythmias, may co-exist with myositis and myasthenia gravis, can be severe, and portends a poor prognosis. In addition, pericardial disease, vasculitis, including temporal arteritis, and non-inflammatory heart failure, have been recently described as immune-related toxicities from ICI. This narrative review describes the epidemiology, diagnosis, pathophysiology, and treatment of cardiovascular toxicities of ICI therapy, highlighting recent developments in the field in the past year.

8.
Eur J Heart Fail ; 21(3): 272-285, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30714667

RESUMO

Fibrosis is a pivotal player in heart failure development and progression. Measurements of (markers of) fibrosis in tissue and blood may help to diagnose and risk stratify patients with heart failure, and its treatment may be effective in preventing heart failure and its progression. A lack of pathophysiological insights and uniform definitions has hampered the research in fibrosis and heart failure. The Translational Research Committee of the Heart Failure Association discussed several aspects of fibrosis in their workshop. Early insidious perturbations such as subclinical hypertension or inflammation may trigger first fibrotic events, while more dramatic triggers such as myocardial infarction and myocarditis give rise to full blown scar formation and ongoing fibrosis in diseased hearts. Aging itself is also associated with a cardiac phenotype that includes fibrosis. Fibrosis is an extremely heterogeneous phenomenon, as several stages of the fibrotic process exist, each with different fibrosis subtypes and a different composition of various cells and proteins - resulting in a very complex pathophysiology. As a result, detection of fibrosis, e.g. using current cardiac imaging modalities or plasma biomarkers, will detect only specific subforms of fibrosis, but cannot capture all aspects of the complex fibrotic process. Furthermore, several anti-fibrotic therapies are under investigation, but such therapies generally target aspecific aspects of the fibrotic process and suffer from a lack of precision. This review discusses the mechanisms and the caveats and proposes a roadmap for future research.

9.
ESC Heart Fail ; 5(6): 1083-1091, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30570223

RESUMO

During the 'Heart Failure and World Congress on Acute Heart Failure 2018', many sessions and lectures focused on cardio-oncology. This important field of research is constantly growing, and therefore, a great amount of time during the congress focused on it. Prevention and early recognition of side effects is very important in cancer patients. One of the most common and potentially severe problems during antineoplastic therapy is cardiotoxicity. Hence, cardio-oncology is vital in managing cancer patients. This paper will summarize the topics discussed in three main sessions and many additional lectures throughout the 'Heart Failure and World Congress on Acute Heart Failure 2018'. The covered topics included pathophysiological mechanisms in the development of heart failure, risk factors, and early signs of cardiotoxicity detectable with different circulating and imaging biomarkers, as well as cardioprotective treatments recommended by different guidelines and position papers.


Assuntos
Cardiologia , Insuficiência Cardíaca/etiologia , Oncologia , Neoplasias/induzido quimicamente , Doença Aguda , Congressos como Assunto , Humanos
10.
J Physiol ; 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30462352

RESUMO

KEY POINTS: Hearts from type 2 diabetic animals display perturbations in excitation-contraction coupling, impairing myocyte contractility and delaying relaxation, along with altered substrate consumption patterns. Under high glucose and ß-adrenergic stimulation conditions, palmitate can, at least in part, offset left ventricle (LV) dysfunction in hearts from diabetic mice improving contractility and relaxation while restoring coronary perfusion pressure. Fluxome calculations of central catabolism in diabetic hearts show that, in presence of palmitate, there is a metabolic remodeling involving tricarboxylic acid cycle, polyol and pentose phosphate pathways, leading to improved redox balance in cytoplasmic and mitochondrial compartments. Under high glucose and increased energy demand, the metabolic/fluxomic re-direction leading to restored redox balance imparted by palmitate helps explain maintained LV function and may contribute to design novel therapeutic approaches to prevent cardiac dysfunction in diabetic patients. ABSTRACT: Type-2 diabetes (T2DM) leads to reduced myocardial performance, and eventually heart failure. Excessive accumulation of lipids and glucose are central to T2DM cardiomyopathy. Previous data showed that palmitate (Palm) or glutathione preserved heart mitochondrial energy/redox balance under excess glucose rescuing ß-adrenergic-stimulated cardiac excitation-contraction coupling. However, the mechanisms underlying the accompanying improved contractile performance have been largely ignored. Herein we explore in intact heart under substrate excess the metabolic remodeling associated with cardiac function in diabetic db/db mice subjected to stress given by ß-adrenergic stimulation with isoproterenol and high-glucose compared to their nondiabetic controls (+/+, WT) under euglycemic conditions. When perfused with Palm, T2DM hearts exhibit improved contractility/relaxation compared to WT, accompanied by extensive metabolic remodeling as demonstrated by metabolomics-fluxomics combined with bioinformatics and computational modeling. The T2DM heart metabolome showed significant differences in the abundance of metabolites in pathways related to glucose, lipids, and redox metabolism. Using a validated computational model of heart's central catabolism, comprising glucose and fatty acid (FA) oxidation in cytoplasmic and mitochondrial compartments, we estimated that fluxes through glucose degradation pathways are ∼2-fold lower in heart from T2DM vs. WT under all conditions studied. Palm addition elicits improvement of the redox status via enhanced ß-oxidation and decreased glucose uptake, leading to flux-redirection away from redox-consuming pathways (e.g., polyol) while maintaining the flux through redox-generating pathways together with glucose-FA "shared fueling" of oxidative phosphorylation. Thus, available FAs such as Palm may help improve function via enhanced redox balance in T2DM hearts during peaks of hyperglycemia and increased workload. Sonia Cortassa has a PhD in Chemical Sciences from the Universidad Nacional de Córdoba, Argentina, country where she held research and teaching positions at Universidad Nacional de Tucumán and Consejo Nacional Investigaciones Científicas y Técnicas (CONICET). In the United States of America, she continued her research at the Johns Hopkins University and, at present, at the Laboratory of Cardiovascular Sciences/National Institute on Aging/NIH. Her field of research is Physiology, Bioenergetics, with expertise in Computational modeling of metabolic networks. She believes that quantitative Systems Biology approaches represent a real opportunity to contribute to the understanding of human body function in health and disease. This article is protected by copyright. All rights reserved.

12.
Eur Heart J ; 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30295807

RESUMO

Acute heart failure (HF) and in particular, cardiogenic shock are associated with high morbidity and mortality. A therapeutic dilemma is that the use of positive inotropic agents, such as catecholamines or phosphodiesterase-inhibitors, is associated with increased mortality. Newer drugs, such as levosimendan or omecamtiv mecarbil, target sarcomeres to improve systolic function putatively without elevating intracellular Ca2+. Although meta-analyses of smaller trials suggested that levosimendan is associated with a better outcome than dobutamine, larger comparative trials failed to confirm this observation. For omecamtiv mecarbil, Phase II clinical trials suggest a favourable haemodynamic profile in patients with acute and chronic HF, and a Phase III morbidity/mortality trial in patients with chronic HF has recently begun. Here, we review the pathophysiological basis of systolic dysfunction in patients with HF and the mechanisms through which different inotropic agents improve cardiac function. Since adenosine triphosphate and reactive oxygen species production in mitochondria are intimately linked to the processes of excitation-contraction coupling, we also discuss the impact of inotropic agents on mitochondrial bioenergetics and redox regulation. Therefore, this position paper should help identify novel targets for treatments that could not only safely improve systolic and diastolic function acutely, but potentially also myocardial structure and function over a longer-term.

13.
J Cardiovasc Med (Hagerstown) ; 19(11): 613-623, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30048301

RESUMO

: The right ventricle has become increasingly studied in cardiovascular research. In this article, we describe specific pathophysiological characteristics of the right ventricle, with special focus on functional and molecular modifications as well as therapeutic strategies in right ventricular dysfunction, underlining the differences with the left ventricle. Then we analyze the main imaging modalities to assess right ventricular function in different clinical settings. Finally, we acknowledge main therapeutic advances for treatment of right heart diseases.

14.
Cardiovasc Res ; 114(10): 1273-1280, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29912308

RESUMO

Disturbed metabolism as a consequence of obesity and diabetes may cause cardiac diseases (recently highlighted in the cardiovascular research spotlight issue on metabolic cardiomyopathies).1 In turn, the metabolism of the heart may also be disturbed in genetic and acquired forms of hypertrophic cardiac disease. Herein, we provide an overview of recent insights on metabolic changes in genetic hypertrophic cardiomyopathy and discuss several therapies, which may be explored to target disturbed metabolism and prevent onset of cardiac hypertrophy.This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.

15.
Cardiovasc Res ; 114(10): 1287-1303, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29800419

RESUMO

Dilated cardiomyopathy (DCM) frequently affects relatively young, economically, and socially active adults, and is an important cause of heart failure and transplantation. DCM is a complex disease and its pathological architecture encounters many genetic determinants interacting with environmental factors. The old perspective that every pathogenic gene mutation would lead to a diseased heart, is now being replaced by the novel observation that the phenotype depends not only on the penetrance-malignancy of the mutated gene-but also on epigenetics, age, toxic factors, pregnancy, and a diversity of acquired diseases. This review discusses how gene mutations will result in mutation-specific molecular alterations in the heart including increased mitochondrial oxidation (sarcomeric gene e.g. TTN), decreased calcium sensitivity (sarcomeric genes), fibrosis (e.g. LMNA and TTN), or inflammation. Therefore, getting a complete picture of the DCM patient will include genomic data, molecular assessment by preference from cardiac samples, stratification according to co-morbidities, and phenotypic description. Those data will help to better guide the heart failure and anti-arrhythmic treatment, predict response to therapy, develop novel siRNA-based gene silencing for malignant gene mutations, or intervene with mutation-specific altered gene pathways in the heart.This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.

16.
JCI Insight ; 3(6)2018 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-29563334

RESUMO

Hypertrophic cardiomyopathy (HCM) stems from mutations in sarcomeric proteins that elicit distinct biophysical sequelae, which in turn may yield radically different intracellular signaling and molecular pathologic profiles. These signaling events remain largely unaddressed by clinical trials that have selected patients based on clinical HCM diagnosis, irrespective of genotype. In this study, we determined how two mouse models of HCM differ, with respect to cellular/mitochondrial function and molecular biosignatures, at an early stage of disease. We show that hearts from young R92W-TnT and R403Q-αMyHC mutation-bearing mice differ in their transcriptome, miRNome, intracellular redox environment, mitochondrial antioxidant defense mechanisms, and susceptibility to mitochondrial permeability transition pore opening. Pathway analysis of mRNA-sequencing data and microRNA profiles indicate that R92W-TnT mutants exhibit a biosignature consistent with activation of profibrotic TGF-ß signaling. Our results suggest that the oxidative environment and mitochondrial impairment in young R92W-TnT mice promote activation of TGF-ß signaling that foreshadows a pernicious phenotype in young individuals. Of the two mutations, R92W-TnT is more likely to benefit from anti-TGF-ß signaling effects conferred by angiotensin receptor blockers and may be responsive to mitochondrial antioxidant strategies in the early stage of disease. Molecular and functional profiling may therefore serve as aids to guide precision therapy for HCM.

17.
Front Physiol ; 9: 167, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29563880

RESUMO

Antineoplastic drugs can be associated with several side effects, including cardiovascular toxicity (CTX). Biochemical studies have identified multiple mechanisms of CTX. Chemoterapeutic agents can alter redox homeostasis by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species RNS. Cellular sources of ROS/RNS are cardiomyocytes, endothelial cells, stromal and inflammatory cells in the heart. Mitochondria, peroxisomes and other subcellular components are central hubs that control redox homeostasis. Mitochondria are central targets for antineoplastic drug-induced CTX. Understanding the mechanisms of CTX is fundamental for effective cardioprotection, without compromising the efficacy of anticancer treatments. Type 1 CTX is associated with irreversible cardiac cell injury and is typically caused by anthracyclines and conventional chemotherapeutic agents. Type 2 CTX, associated with reversible myocardial dysfunction, is generally caused by biologicals and targeted drugs. Although oxidative/nitrosative reactions play a central role in CTX caused by different antineoplastic drugs, additional mechanisms involving directly and indirectly cardiomyocytes and inflammatory cells play a role in cardiovascular toxicities. Identification of cardiologic risk factors and an integrated approach using molecular, imaging, and clinical data may allow the selection of patients at risk of developing chemotherapy-related CTX. Although the last decade has witnessed intense research related to the molecular and biochemical mechanisms of CTX of antineoplastic drugs, experimental and clinical studies are urgently needed to balance safety and efficacy of novel cancer therapies.

19.
Pulm Circ ; 8(2): 2045894018769874, 2018 Apr-Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29575972

RESUMO

Atrial arrhythmia (AA) occurrence in pulmonary arterial hypertension (PAH) may determine clinical deterioration and affect prognosis. In this study we assessed AA incidence in idiopathic (IPAH) and systemic sclerosis related PAH (SSc-PAH) and evaluated risk factors, management, and impact on mortality. We collected baseline data from consecutive IPAH or SSc-PAH patients prospectively enrolled in the Johns Hopkins Pulmonary Hypertension Registry between January 2000 and July 2016. During follow-up AA onset, treatment, and outcome were recorded. Among 317 patients (201 SSc-PAH, 116 IPAH), 42 developed AA (19 atrial fibrillation, 10 flutter-fibrillation, 9 atrial flutter, and 4 atrial ectopic tachycardia) with a 13.2% cumulative incidence. Most events were associated with hospitalization (90.5%). Electrical or pharmacological cardioversion was attempted in most cases. Patients with AA had higher right atrial pressure, pulmonary wedge pressure ( P < 0.005), NT-proBNP ( P < 0.05), and thyroid disease prevalence ( P < 0.005). Higher mortality was observed in patients with AA, though not statistically significant (LogRank P = 0.323). Similar long-term mortality between IPAH with AA and SSc-PAH without AA was observed (LogRank P = 0.098). SSc-PAH with AA had the worst prognosis. In PAH patients AA occurrence is a matter of significant concern. Therapeutic strategies aimed at restoring sinus rhythm may represent an important goal.

20.
Front Physiol ; 9: 38, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29467663

RESUMO

The ErbB2 blocker trastuzumab improves survival in oncologic patients, but can cause cardiotoxicity. The late Na+ current inhibitor ranolazine has been shown to counter experimental HF, including doxorubicin cardiotoxicity (a condition characterized by derangements in redox balance), by lowering the levels of reactive oxygen species (ROS). Since ErbB2 can modulate ROS signaling, we tested whether trastuzumab cardiotoxicity could be blunted by ranolazine via redox-mediated mechanisms. Trastuzumab decreased fractional shortening and ejection fraction in mice, but ranolazine prevented heart dysfunction when co-administered with trastuzumab. Trastuzumab cardiotoxicity was accompanied by elevations in natriuretic peptides and matrix metalloproteinase 2 (MMP2) mRNAs, which were not elevated with co-treatment with ranolazine. Trastuzumab also increased cleavage of caspase-3, indicating activation of the proapoptotic machinery. Again, ranolazine prevented this activation. Interestingly, Neonatal Rat Ventricular Myocytes (NRVMs), labeled with MitoTracker Red and treated with trastuzumab, showed only a small increase in ROS compared to baseline conditions. We then stressed trastuzumab-treated cells with the beta-agonist isoproterenol to increase workload, and we observed a significant increase of probe fluorescence, compared with cells treated with isoproterenol alone, reflecting induction of oxidative stress. These effects were blunted by ranolazine, supporting a role for INa inhibition in the regulation of redox balance also in trastuzumab cardiotoxicity.

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