Abstract 165: The 18 kDa FGF-2 Prevents the Doxorubicin-induced Cardiac Damage and Amp-activated Kinase Activation, in vitro and in vivo

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Navid Koleini ◽  
Jon Jon Santiago ◽  
Barbara E Nickel ◽  
Robert Fandrich ◽  
Davinder S Jassal ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cell Death ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Wild Type ◽  
Rat Cardiomyocytes ◽  
Ventricular Ejection Fraction ◽  
Compound C

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.

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
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Cardiac Fibroblasts ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Resting Membrane Potential ◽  
Ventricular Ejection Fraction ◽  
Cardiac Tissues

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.

Rapid ventricular pacing of dogs to heart failure: biochemical and physiological studies

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
Keyword(s):  
Heart Failure ◽  
Glycolytic Enzyme ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Pacing ◽  
Ventricular Ejection Fraction ◽  
Biochemical Alterations ◽  
Rapid Ventricular Pacing

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.

Exosomes secreted by hiPSC-derived cardiac cells improve recovery from myocardial infarction in swine

2020 ◽  
Vol 12 (561) ◽  
pp. eaay1318 ◽  
Author(s):  
Ling Gao ◽  
Lu Wang ◽  
Yuhua Wei ◽  
Prasanna Krishnamurthy ◽  
Gregory P. Walcott ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Therapeutic Option ◽  
Wall Stress ◽  
Left Ventricular ◽  
Cardiac Cells ◽  
Left Ventricular Ejection ◽  
Cell Group ◽  
Ventricular Ejection Fraction

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.

scholarly journals Adropin-based dual treatment enhances the therapeutic potential of mesenchymal stem cells in rat myocardial infarction

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
HuiYa Li ◽  
DanQing Hu ◽  
Guilin Chen ◽  
DeDong Zheng ◽  
ShuMei Li ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Potential ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Paracrine Factors ◽  
Dual Treatment

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.

Electrophysiologic properties and ventricular fibrillation in normal and myopathic hearts

1999 ◽  
Vol 77 (7) ◽  
pp. 510-519 ◽  
Author(s):  
Katherine M Kavanagh ◽  
Patricia A Guerrero ◽  
Bodh I Jugdutt ◽  
Francis X Witkowski ◽  
Jeffrey E Saffitz
Keyword(s):  
Ventricular Fibrillation ◽  
Myocardial Dysfunction ◽  
Myocardial Cell ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Control Group ◽  
Functional Abnormality ◽  
Ventricular Ejection Fraction ◽  
Anisotropic Properties

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.

scholarly journals Bone marrow-derived stromal cells home to and remain in the infarcted rat heart but fail to improve function: an in vivo cine-MRI study

2008 ◽  
Vol 295 (2) ◽  
pp. H533-H542 ◽  
Author(s):  
Carolyn A. Carr ◽  
Daniel J. Stuckey ◽  
Louise Tatton ◽  
Damian J. Tyler ◽  
Sarah J. M. Hale ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Therapy ◽  
Cardiac Function ◽  
Stromal Cells ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Cine Mri ◽  
Iron Oxide Particles ◽  
Ventricular Ejection Fraction

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.

scholarly journals GH Receptor Exon 3 Genotype and Echocardiographic Abnormalities in Patients With Active Acromegaly

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A643-A644
Author(s):  
Karla Serrano ◽  
Etual Espinosa ◽  
Daniel Marrero-Rodríguez ◽  
Eduardo Almeida ◽  
Gloria Silva-Roman ◽  
...  
Keyword(s):  
Systolic Dysfunction ◽  
Cross Sectional Study ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Genotype 3 ◽  
Cross Sectional ◽  
Ventricular Ejection Fraction ◽  
Gh Receptor ◽  
Active Acromegaly

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.

P336A descriptive analysis of patients with wild-type ATTR cardiomyopathy from the transthyretin amyloidosis outcomes survey

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
P Garcia-Pavia ◽  
M Grogan ◽  
A Dispenzieri ◽  
R Mundayat ◽  
L Amass ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Cardiac Disease ◽  
The United States ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Motor Neuropathy ◽  
Wild Type ◽  
Transthyretin Amyloidosis ◽  
Ventricular Ejection Fraction ◽  
Attr Amyloidosis

Abstract Introduction Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disorder caused by the deposition of amyloid fibrils composed of misfolded transthyretin (TTR). ATTR amyloidosis may arise from mutations in TTR or from aggregation of wild-type TTR (ATTRwt). ATTR amyloidosis with predominantly symptoms of cardiomyopathy (ATTR-CM) includes both hereditary and wild-type forms of the disease. Purpose To describe clinical history and disease presentation in a large population of patients with wild-type ATTR-CM from the Transthyretin Amyloidosis Outcomes Survey (THAOS). THAOS is an ongoing, global, longitudinal, observational survey of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic patients with TTR mutations. Methods Data from ATTRwt patients were extracted from THAOS (cut-off date: January 16, 2019) and demographic and clinical characteristics reported using descriptive statistics. Results There were 758 ATTRwt patients in THAOS (95% male). The majority of patients (69.3%) were in the United States, with the remainder in Italy (11.1%), Germany (7.3%), Spain (5.3%), and other countries (7.1%). Most patients (86.3%) were Caucasian, with 3.3% being of African Descent and 3.1% being of other races/ethnicities (7.4% missing data). The median (10–90th percentile) age at symptom onset was 69.7 (54.0–81.3) years and the median (10–90th percentile) time from symptom onset to diagnosis was 3.9 (0.1–17.8) years. Median (10–90th percentile) age at enrollment in THAOS was 76.4 (67.2–85.2) years. Nearly all subjects had either a cardiac (59.6%) or mixed cardiac and neurologic (36.5%) phenotype. At enrollment, 97.1% (577 of 594 patients assessed) had an abnormal ECG, with the prevalence of low voltage being 20.8% (115 of 552) and prevalence of left-ventricular hypertrophy being 2.1% (16 of 758). Atrial fibrillation was documented in 55% of patients (208 of 378). The mean (standard deviation [SD]) left-ventricular septum thickness was 17.5 (3.5) mm (n=505; 94.9% with thickness >12 mm) and mean (SD) left-ventricular ejection fraction (LVEF) was 48.3% (13.2) (n=511; 48.0% with LVEF <50.0%). Other signs and symptoms at enrollment were compatible with a sensory neuropathy in 54.2% of patients, autonomic neuropathy in 33.5% of patients, and motor neuropathy in 29.1% of patients. Gastrointestinal symptoms related to ATTR amyloidosis were present in 10.4% of patients. Conclusions Although patients with wild-type ATTR-CM tend to be older Caucasian men with a mostly cardiac disease phenotype, the clinical spectrum of ATTRwt is heterogeneous and differs from the classic phenotype. Our findings show that ATTRwt should not be considered an exclusively cardiac disease and there is a need for both cardiologic and neurologic assessment of these patients. Further study is needed to determine if the non-cardiac manifestations are due to amyloidosis or more common causes in this older population. Acknowledgement/Funding This study was sponsored by Pfizer.

scholarly journals Prophylactic, single-drug cardioprotection in a comparative, experimental study of doxorubicin-induced cardiomyopathy

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Mária Lódi ◽  
Viktor Bánhegyi ◽  
Beáta Bódi ◽  
Alexandra Gyöngyösi ◽  
Árpád Kovács ◽  
...  
Keyword(s):  
Enzyme Inhibitor ◽  
Primary Prophylaxis ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Common Side Effect ◽  
Serum Samples ◽  
Ventricular Ejection Fraction ◽  
Oncological Patients ◽  
Male Wistar Rats

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.

scholarly journals miR-19a-3p containing exosomes improve function of ischaemic myocardium upon shock wave therapy

2019 ◽  
Vol 116 (6) ◽  
pp. 1226-1236 ◽  
Author(s):  
Can Gollmann-Tepeköylü ◽  
Leo Pölzl ◽  
Michael Graber ◽  
Jakob Hirsch ◽  
Felix Nägele ◽  
...  
Keyword(s):  
Shock Wave ◽  
Myocardial Fibrosis ◽  
Myocardial Ischaemia ◽  
Heart Function ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Shock Wave Therapy ◽  
Ventricular Ejection Fraction ◽  
Ischaemic Myocardium

Abstract Aims As many current approaches for heart regeneration exert unfavourable side effects, the induction of endogenous repair mechanisms in ischaemic heart disease is of particular interest. Recently, exosomes carrying angiogenic miRNAs have been described to improve heart function. However, it remains challenging to stimulate specific release of reparative exosomes in ischaemic myocardium. In the present study, we sought to test the hypothesis that the physical stimulus of shock wave therapy (SWT) causes the release of exosomes. We aimed to substantiate the pro-angiogenic impact of the released factors, to identify the nature of their cargo, and to test their efficacy in vivo supporting regeneration and recovery after myocardial ischaemia. Methods and results Mechanical stimulation of ischaemic muscle via SWT caused extracellular vesicle (EV) release from endothelial cells both in vitro and in vivo. Characterization of EVs via electron microscopy, nanoparticle tracking analysis and flow cytometry revealed specific exosome morphology and size with the presence of exosome markers CD9, CD81, and CD63. Exosomes exhibited angiogenic properties activating protein kinase b (Akt) and extracellular-signal regulated kinase (ERK) resulting in enhanced endothelial tube formation and proliferation. A miRNA array and transcriptome analysis via next-generation sequencing were performed to specify exosome content. miR-19a-3p was identified as responsible cargo, antimir-19a-3p antagonized angiogenic exosome effects. Exosomes and target miRNA were injected intramyocardially in mice after left anterior descending artery ligation. Exosomes resulted in improved vascularization, decreased myocardial fibrosis, and increased left ventricular ejection fraction as shown by transthoracic echocardiography. Conclusion The mechanical stimulus of SWT causes release of angiogenic exosomes. miR-19a-3p is the vesicular cargo responsible for the observed effects. Released exosomes induce angiogenesis, decrease myocardial fibrosis, and improve left ventricular function after myocardial ischaemia. Exosome release via SWT could develop an innovative approach for the regeneration of ischaemic myocardium.

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