Abstract 542: Chronic Doxorubicin Cardiotoxicity Assessed in Engineered Cardiac Tissues Generated in Biowire™ II Platform

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Roozbeh Aschar-sobbi ◽  
Julia E Napolitano ◽  
Danielle R Bogdanowicz ◽  
Michael P Graziano

The anthracycline doxorubicin is an effective anti-tumor agent widely used in both adults and children. One major adverse effect of doxorubicin therapy is dose-dependent cardiotoxicity, ranging from asymptomatic reduction in left ventricular ejection fraction to more serious, potentially fatal symptoms including arrythmias and congestive heart failure. The exact mechanism of doxorubicin-induced cardiotoxicity remains unknown. Recently, human induced pluripotent stem cells (hiPSC) have emerged as a potential tool to model cardiac toxicity, but their fetal-like phenotype raises concerns about the translatability of in vitro data to in vivo cardiotoxicity. To overcome this limitation, Biowire™ II platform was used to generate 3D engineered cardiac tissues (ECTs) from hiPSC-derived cardiomyocytes and human cardiac fibroblasts. Using long-term electrical stimulation, ECTs with a phenotype approaching that of adult human myocardium were obtained. The ECTs were then exposed to 1 μM doxorubicin for 8 days followed by 7 days of washout. Measurements of contractile force amplitude at 1 Hz stimulation showed a transient increase in force within 24 hours of doxorubicin exposure followed by decrease in force after 2 days. Intracellular recordings of action potential (AP) showed a decrease in maximum upstroke velocity (dV/dt), AP amplitude (APA), and resting membrane potential (RMP) after 8 days of doxorubicin treatment. In addition, action potential duration (APD) at 30% (APD30) repolarization was increased in doxorubicin-treated ECTs, whereas APD50 and APD90 were decreased. Following 7 days of washout, no difference in force or AP parameters was found between doxorubicin and vehicle-treated ECTs with the exception of APD50 and APD90 which remained abbreviated. A global untargeted analysis of the conditioned media from doxorubicin-treated ECTs identified 204 analytes and revealed an upregulation of redox homeostasis, differential fatty acid metabolism, altered glycolysis and TCA cycle metabolites, and decreased nucleoside metabolism compared to vehicle-treated ECTs. These results show that doxorubicin not only increases oxidative stress, but also irreversibly affects action potential duration which may predispose to cardiac arrhythmias.

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Navid Koleini ◽  
Jon Jon Santiago ◽  
Barbara E Nickel ◽  
Robert Fandrich ◽  
Davinder S Jassal ◽  
...  

Introduction: Protection of the heart from chemotherapeutic (Doxorubicin, DOX) drug-induced toxicity is a desirable goal, to limit side effects of cancer treatments. DOX toxicity has been linked to the activation (phosphorylation) of the AMP-activated kinase, AMPK. The 18 kDa low molecular weight isoform of fibroblast growth factor 2 (Lo-FGF-2) is a known cardioprotective and cytoprotective agent. In this study we have tested the ability of Lo-FGF-2 to protect from DOX-induced damage in rat cardiomyocytes in vitro, and in transgenic mouse models in vivo, in relation to AMPK activation. Methods: Rat neonatal cardiomyocytes in culture were exposed to DOX (0.5 μM) in the presence or absence of pre-treatment Lo-FGF-2 (10 ng/ml). Compound C was used to block phosphorylation (activity) of AMPK. Levels of cell viability/death (using Calcein-AM/Propidium iodide assay), phospho -and total AMPK, and apoptotic markers such as active caspase 3 were analyzed. In addition, transgenic mice expressing only Lo-FGF2, and wild type mice, expressing both high molecular weight (Hi-FGF2) as well as Lo-FGF2 were subjected to DOX injection (20 mg/kg, intraperitoneal); echocardiography was used to examine cardiac function at baseline and at 10 days post-DOX. Results: DOX-induced cell death of cardiomyocytes in culture was maximal at 24 hours post-DOX coinciding with significantly increased in activated (phosphorylated) AMPK. Compound C attenuated DOX-induced cardiomyocyte loss. Pre-incubation with Lo-FGF-2 decreased DOX induced cell death, and also attenuated the phosphorylation of AMPK post-DOX. Relative levels of phospho-AMPK were lower in the hearts of Lo-FGF2-expressing male mice compared to wild type. DOX-induced loss of contractile function (left ventricular ejection fraction and endocardial velocity) was negligible in Lo-FGF2-expressing mice but significant in wild type mice. Conclusion: Lo-FGF-2 protects the heart from DOX-induced damage in vitro and in vivo, by a mechanism likely involving an attenuation of AMPK activity.


1990 ◽  
Vol 68 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Peter James O'Brien ◽  
C. David Ianuzzo ◽  
Gordon W. Moe ◽  
Terry P. Stopps ◽  
Paul W. Armstrong

Chronic, rapid ventricular pacing produces congestive heart failure in dogs. The objectives of this study were to determine whether or not (i) in vitro myocardial biochemical alterations reported for heart failure by volume or pressure overload also occurred with heart failure due to rate overload, and (ii) these biochemical alterations were related to relevant in vivo cardiac physiologic alterations. We compared 27 dogs that were paced to advanced heart failure with 21 sham-operated dogs. Dogs with heart failure had 55% lower left ventricular ejection fraction (22.5 ± 7.6 vs. 50.5 ± 5.1%) and cardiac index (81 ± 22 vs. 178 ± 48 mL∙min−1∙kg−1), 287% higher pulmonary capillary wedge pressure (27.5 ± 6.8 vs. 7.1 ± 3.4 mmHg; 1 mmHg = 133.3 Pa), and 64% greater left ventricular diastolic area (18.4 ± 3.7 vs. 11.2 ± 1.3 cm2) (all p < 0.05). Dogs with heart failure also had (i) 69% lower norepinephrine (232 ± 139 vs. 747 ± 220 ng/g protein), (ii) 25–50% lower activities of myofibrillar Ca ATPase (0.188 ± 0.026 vs. 0.253 ± 0.051 U/mg myofibrils), sarcoplasmic reticulum Ca-transport ATPase (0.155 ± 0.074 vs. 0.288 ± 0.043 U/mg membrane), and the glycolytic enzyme phosphofructokinase (33.4 ± 10.0 and 47.7 ± 15.8 U/g), (iii) 32% higher activity of the β-oxidation enzyme hydroxyacyl-CoA dehydrogenase (11.43 ± 1.48 vs. 8.67 ± 1.70 U/g), and (iv) 60% higher activity of Krebs cycle oxoglutarate dehydrogenase (2.89 ± 0.77 vs. 1.81 ± 0.95 U/g) (all p < 0.05). No differences between groups were observed for isozyme patterns and ATPase activity of myosin. The pacing-induced alterations in left ventricular norepinephrine and sarcoplasmic reticular and myofibrillar Ca ATPase best correlated with in vivo physiological alterations. Biochemical alterations produced by rate overload were similar to those reported for volume or pressure overload.Key words: heart disease, chronic tachycardia, biochemical changes.


Author(s):  
Joseph S. Piktel ◽  
Yi Suen ◽  
Shalen Kouk ◽  
Danielle Maleski ◽  
Gary Pawlowski ◽  
...  

Background Amiodarone is administered during resuscitation, but its antiarrhythmic effects during targeted temperature management are unknown. The purpose of this study was to determine the effect of both therapeutic hypothermia and amiodarone on arrhythmia substrates during resuscitation from cardiac arrest. Methods and Results We utilized 2 complementary models: (1) In vitro no‐flow global ischemia canine left ventricular transmural wedge preparation. Wedges at different temperatures (36°C or 32°C) were given 5 µmol/L amiodarone (36‐Amio or 32‐Amio, each n=8) and subsequently underwent ischemia and reperfusion. Results were compared with previous controls. Optical mapping was used to measure action potential duration, dispersion of repolarization (DOR), and conduction velocity (CV). (2) In vivo pig model of resuscitation. Pigs (control or targeted temperature management, 32–34°C) underwent ischemic cardiac arrest and were administered amiodarone (or not) after 8 minutes of ventricular fibrillation. In vitro: therapeutic hypothermia but not amiodarone prolonged action potential duration. During ischemia, DOR increased in the 32‐Amio group versus 32‐Alone (84±7 ms versus 40±7 ms, P <0.05) while CV slowed in the 32‐Amio group. Amiodarone did not affect CV, DOR, or action potential duration during ischemia at 36°C. Conduction block was only observed at 36°C (5/8 36‐Amio versus 6/7 36‐Alone, 0/8 32‐Amio, versus 0/7 32‐Alone). In vivo: QTc decreased upon reperfusion from ischemia that was ameliorated by targeted temperature management. Amiodarone did not worsen DOR or CV. Amiodarone suppressed rearrest caused by ventricular fibrillation (7/8 without amiodarone, 2/7 with amiodarone, P =0.041), but not pulseless electrical activity (2/8 without amiodarone, 5/7 with amiodarone, P =0.13). Conclusions Although amiodarone abolishes a beneficial effect of therapeutic hypothermia on ischemia‐induced DOR and CV, it did not worsen susceptibility to ventricular tachycardia/ventricular fibrillation during resuscitation.


2020 ◽  
Vol 12 (561) ◽  
pp. eaay1318 ◽  
Author(s):  
Ling Gao ◽  
Lu Wang ◽  
Yuhua Wei ◽  
Prasanna Krishnamurthy ◽  
Gregory P. Walcott ◽  
...  

Cell therapy treatment of myocardial infarction (MI) is mediated, in part, by exosomes secreted from transplanted cells. Thus, we compared the efficacy of treatment with a mixture of cardiomyocytes (CMs; 10 million), endothelial cells (ECs; 5 million), and smooth muscle cells (SMCs; 5 million) derived from human induced pluripotent stem cells (hiPSCs), or with exosomes extracted from the three cell types, in pigs after MI. Female pigs received sham surgery; infarction without treatment (MI group); or infarction and treatment with hiPSC-CMs, hiPSC-ECs, and hiPSC-SMCs (MI + Cell group); with homogenized fragments from the same dose of cells administered to the MI + Cell group (MI + Fra group); or with exosomes (7.5 mg) extracted from a 2:1:1 mixture of hiPSC-CMs:hiPSC-ECs:hiPSC-SMCs (MI + Exo group). Cells and exosomes were injected into the injured myocardium. In vitro, exosomes promoted EC tube formation and microvessel sprouting from mouse aortic rings and protected hiPSC-CMs by reducing apoptosis, maintaining intracellular calcium homeostasis, and increasing adenosine 5′-triphosphate. In vivo, measurements of left ventricular ejection fraction, wall stress, myocardial bioenergetics, cardiac hypertrophy, scar size, cell apoptosis, and angiogenesis in the infarcted region were better in the MI + Cell, MI + Fra, and MI + Exo groups than in the MI group 4 weeks after infarction. The frequencies of arrhythmic events in animals from the MI, MI + Cell, and MI + Exo groups were similar. Thus, exosomes secreted by hiPSC-derived cardiac cells improved myocardial recovery without increasing the frequency of arrhythmogenic complications and may provide an acellular therapeutic option for myocardial injury.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
HuiYa Li ◽  
DanQing Hu ◽  
Guilin Chen ◽  
DeDong Zheng ◽  
ShuMei Li ◽  
...  

AbstractBoth weak survival ability of stem cells and hostile microenvironment are dual dilemma for cell therapy. Adropin, a bioactive substance, has been demonstrated to be cytoprotective. We therefore hypothesized that adropin may produce dual protective effects on the therapeutic potential of stem cells in myocardial infarction by employing an adropin-based dual treatment of promoting stem cell survival in vitro and modifying microenvironment in vivo. In the current study, adropin (25 ng/ml) in vitro reduced hydrogen peroxide-induced apoptosis in rat bone marrow mesenchymal stem cells (MSCs) and improved MSCs survival with increased phosphorylation of Akt and extracellular regulated protein kinases (ERK) l/2. Adropin-induced cytoprotection was blocked by the inhibitors of Akt and ERK1/2. The left main coronary artery of rats was ligated for 3 or 28 days to induce myocardial infarction. Bromodeoxyuridine (BrdU)-labeled MSCs, which were in vitro pretreated with adropin, were in vivo intramyocardially injected after ischemia, following an intravenous injection of 0.2 mg/kg adropin (dual treatment). Compared with MSCs transplantation alone, the dual treatment with adropin reported a higher level of interleukin-10, a lower level of tumor necrosis factor-α and interleukin-1β in plasma at day 3, and higher left ventricular ejection fraction and expression of paracrine factors at day 28, with less myocardial fibrosis and higher capillary density, and produced more surviving BrdU-positive cells at day 3 and 28. In conclusion, our data evidence that adropin-based dual treatment may enhance the therapeutic potential of MSCs to repair myocardium through paracrine mechanism via the pro-survival pathways.


1999 ◽  
Vol 77 (7) ◽  
pp. 510-519 ◽  
Author(s):  
Katherine M Kavanagh ◽  
Patricia A Guerrero ◽  
Bodh I Jugdutt ◽  
Francis X Witkowski ◽  
Jeffrey E Saffitz

This study tests the hypothesis that moderate myocardial dysfunction is associated with altered myocardial anisotropic properties and structurally altered ventricular fibrillation (VF). Mongrel dogs were randomized to either a control group or a group that was rapidly paced at 250 beats/min until the left ventricular ejection fraction was [Formula: see text] 40%. Changes in anisotropic properties and the electrical characteristics of VF associated with the development of moderate myocardial dysfunction were assessed by microminiature epicardial mapping studies. In vivo conduction, refractory periods, and repolarization times were prolonged in both longitudinal and transverse directions in myopathic animals versus controls. VF was different in myopathic versus control animals. There were significantly more conducted deflections during VF in normal hearts compared with myopathic hearts. Propagated deflection-to-deflection intervals during VF were significantly longer in myopathic hearts compared with controls (125.5 ± 49.06 versus 103.4 ± 32.9 ms, p = 0.009). There were no abnormalities in cell size, cell shape, or the number of intercellular gap junctions and there was no detectable change in the expression of the gap junction proteins Cx43 and Cx45. Moderate myocardial dysfunction is associated with significant electrophysiological abnormalities in the absence of changes in myocardial cell morphology or intercellular connections, suggesting a functional abnormality in cell-to-cell communication.Key words: cardiomyopathy, anisotropy, fibrillation, defibrillation.


1990 ◽  
Vol 258 (3) ◽  
pp. H793-H805 ◽  
Author(s):  
F. S. Fein ◽  
B. E. Zola ◽  
A. Malhotra ◽  
S. Cho ◽  
S. M. Factor ◽  
...  

Left ventricular papillary muscle function, transmembrane action potentials, myosin adenosinetriphosphatase (ATPase) and isoenzyme distribution, and myocardial pathology were studied in hypertensive (H), diabetic (D), hypertensive-diabetic (HD), and control (C) rats. There was approximately 50% relative left ventricular hypertrophy in H and HD rats. Relative lung and liver weights were greater in HD rats. Peak velocity of shortening tended to decrease progressively in H, D, and HD rats. The duration of contraction and relaxation was markedly prolonged in Ds and HDs. The length-developed tension relation was blunted in HDs. The negative inotropic effect of verapamil was similar in all groups. Resting membrane potential and amplitude were decreased in D and HD rats. Action potential duration was increased in H, D, and especially HD rats. The shortening of action potential duration with increased stimulus frequency was greater in H, D, and especially HD rats than in Cs. Left ventricular myosin ATPase and V1 isoenzyme content decreased progressively in H, D, and HD rats. Right ventricular V1 isoenzyme content was not affected in H rats but was markedly decreased in D and HD rats. Left (and right) ventricular pathology was unchanged in rats with diabetes but was increased in rats with hypertension. These data suggest that the combination of myocardial pathology (due to hypertension) and cellular dysfunction (caused mainly by diabetes) may result in cardiomyopathy and congestive heart failure in the HD rat.


2008 ◽  
Vol 295 (2) ◽  
pp. H533-H542 ◽  
Author(s):  
Carolyn A. Carr ◽  
Daniel J. Stuckey ◽  
Louise Tatton ◽  
Damian J. Tyler ◽  
Sarah J. M. Hale ◽  
...  

Basic and clinical studies have shown that bone marrow cell therapy can improve cardiac function following infarction. In experimental animals, reported stem cell-mediated changes range from no measurable improvement to the complete restoration of function. In the clinic, however, the average improvement in left ventricular ejection fraction is around 2% to 3%. A possible explanation for the discrepancy between basic and clinical results is that few basic studies have used the magnetic resonance (MR) imaging (MRI) methods that were used in clinical trials for measuring cardiac function. Consequently, we employed cine-MR to determine the effect of bone marrow stromal cells (BMSCs) on cardiac function in rats. Cultured rat BMSCs were characterized using flow cytometry and labeled with iron oxide particles and a fluorescent marker to allow in vivo cell tracking and ex vivo cell identification, respectively. Neither label affected in vitro cell proliferation or differentiation. Rat hearts were infarcted, and BMSCs or control media were injected into the infarct periphery ( n = 34) or infused systemically ( n = 30). MRI was used to measure cardiac morphology and function and to determine cell distribution for 10 wk after infarction and cell therapy. In vivo MRI, histology, and cell reisolation confirmed successful BMSC delivery and retention within the myocardium throughout the experiment. However, no significant improvement in any measure of cardiac function was observed at any time. We conclude that cultured BMSCs are not the optimal cell population to treat the infarcted heart.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A643-A644
Author(s):  
Karla Serrano ◽  
Etual Espinosa ◽  
Daniel Marrero-Rodríguez ◽  
Eduardo Almeida ◽  
Gloria Silva-Roman ◽  
...  

Abstract Background: The GH receptor (GHR) exon 3 polymorphism occurs at a genomic level. Approximately 50-60% of the population is homozygous for the exon-3 containing genotype (+3/+3), 30-40% are heterozygous (+3/-3) and 10-20% are homozygous for the exon-3 lacking genotype (-3/-3). Some studies suggest that children homo- and heterozygous for the GHR exon 3 lacking genotype (-more efficient 3/-3 and +3/-3, respectively) respond better to treatment with exogenous rhGH and there is also in vitro evidence showing a more efficient signal transduction through this exon 3 deleted isoform. Some studies have found that patients with acromegaly harboring the exon 3-deleted genotype may have a higher prevalence of diabetes and hypertension. Hypothesis and Objective: Patients with active acromegaly harboring the exon 3-lacking GHR genotype may have more echocardiographic abnormalities than those who are homozygous for the exon 3 containing genotype. Patients and Methods: This is a cross-sectional study of patients with active acromegaly, defined by an IGF-1 level &gt; 1.3 times the upper limit of normal (x ULN), who underwent transthoracic echocardiography. Exon-3 GHR genotype was determined by PCR using previously described sense and antisense primers. Results: The cohort consisted of 28 patients, 54% female, with a mean age of 51 ± 12 years. Mean disease duration at the time of echocardiographic examination was 4.48 ± 4.7 years; median basal GH and IGF-1 were 12 ± 26 ng/mL and 2.4 ± 1.04 x ULN. The prevalence of hypertension and diabetes were 43% and 36%, respectively. Fifty three percent of the patients were homozygous for the exon 3-containaing genotype (+3/+3), 18% were homozygous for the exon 3-lacking genotype (-3/-3) and 29% were heterozygous (+3/-3). Clinical and biochemical features did not differ between patients with the different GHR genotypes, except for hypertension that was more prevalent in the +3/+3 genotype group (60% vs 23%, p= 0.04). The frequency of the different echocardiographic parameters was similar among groups (left ventricular hypertrophy 33% vs 15%, p= 0.27; diastolic dysfunction 47% vs 31%, p= 0.39; subclinical systolic dysfunction 42% vs 54%, p= 0.54; left ventricular ejection fraction 59±10% vs 60±16%, p= 0.83); aortic valve abnormalities 19% vs 15%, p=0.63; mitral valve abnormalities 46% vs 15%, p=0.07). Conclusions: Echocardiographic abnormalities in patients with active acromegaly do not differ among patients with the different GHR exon 3 genotypes. The clinical spectrum of acromegaly varies considerably. Although such variability is usually related to the severity of the hypersomatotropinemia, in many patients this is not the case.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Mária Lódi ◽  
Viktor Bánhegyi ◽  
Beáta Bódi ◽  
Alexandra Gyöngyösi ◽  
Árpád Kovács ◽  
...  

Abstract Background Cardiomyopathy is a common side effect of doxorubicin (DOX) chemotherapy. Despite intensive research efforts in the field, there is still no evidence available for routine cardioprotective prophylaxis to prevent cardiotoxicity in the majority of oncological patients at low risk of cardiovascular disease. We have recently demonstrated the advantages of a prophylactic, combined heart failure therapy in an experimental model of DOX-induced cardiomyopathy. In the current work, we focus on individually applied prophylactic medications studied in the same translational environment to clarify their distinct roles in the prevention of DOX cardiotoxicity. Methods Twelve-week-old male Wistar rats were divided into 5 subgroups. Prophylactic β-blocker (BB, bisoprolol), angiotensin-converting enzyme inhibitor (ACEI, perindopril) or aldosterone antagonist (AA, eplerenone) treatments were applied 1 week before DOX administration, then 6 cycles of intravenous DOX chemotherapy were administered. Rats receiving only intravenous DOX or saline served as positive and negative controls. Blood pressure, heart rate, body weight, and echocardiographic parameters were monitored in vivo. Two months after the last DOX administration, the animals were sacrificed, and their heart and serum samples were frozen in liquid nitrogen for histological, mechanical, and biochemical measurements. Results All prophylactic treatments increased the survival of DOX-receiving animals. The lowest mortality rates were seen in the BB and ACEI groups. The left ventricular ejection fraction was only preserved in the BB group. The DOX-induced increase in the isovolumetric relaxation time could not be prevented by any prophylactic treatment. A decreased number of apoptotic nuclei and a preserved myocardial ultrastructure were found in all groups receiving prophylactic cardioprotection, while the DOX-induced fibrotic remodelling and the increase in caspase-3 levels could only be substantially prevented by the BB and ACEI treatments. Conclusion Primary prophylaxis with cardioprotective agents like BB or ACEI has a key role in the prevention of DOX-induced cardiotoxicity in healthy rats. Future human studies are necessary to implement this finding in the clinical management of oncological patients free of cardiovascular risk factors.


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