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Detection of apoptotic cardiomyocytes with the TUNEL assay on the 72nd day. Apoptotic cells were labeled green and are indicated by the yellow arrows (left panel) and the corresponding cardiomyocyte were stained blue with DAPI (right panel). (A) Normal control 2 group, (B) Normal+IVA group, (C) CVMC+IVA group, and (D) CVMC2 group.
Source publication
This study was designed to explore the effects of ivabradine on cardiomyocyte apoptosis in a murine model of chronic viral myocarditis (CVMC). Mice were inoculated intraperitoneally with Coxsackievirus B3 at days 1, 14, and 28, respectively. On day 42, the mice were gavaged with ivabradine for 30 days until the 72nd day. The heart of infected mice...
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Objective
Emerging articles have profiled the relations between microRNAs and viral myocarditis. This research was unearthed to explore the capacity of miR‐425‐3p on cardiomyocyte apoptosis in mice with viral myocarditis and its mechanism.
Methods
A total of 120 mice were classified into 4 groups in a random fashion (n = 30). The mice were intrape...
Background:
The P38 mitogen-activated protein kinase (MAPK) pathway plays an essential role in CVB3-induced diseases. We previously demonstrated microRNA-21 has potential inhibitory effect on the MAP2K3 which locates upstream of P38 MAPK and was upregulated in mouse hearts upon CVB3 infection. However, the effect and underlying mechanism of miRNA-...
Citations
... In a mouse study, ivabradine prevented the progression from coxsackievirus-induced myocarditis to dilated cardiomyopathy through inhibition of the p38 MAPK pathway, downregulation of inflammatory responses, reduction of collagen expression, with a consequent reduction in the fibrogenesis [84]. Ivabradine attenuated the expression of caspase-3 by downregulation of Bax and upregulation of Bcl-2 to prevent the deterioration of cardiac function resulting from ventricular myocyte loss by cardiomyocyte apoptosis [85]. ...
Ivabradine is a pharmacologic agent that inhibits the funny current responsible for determining heart rate in the sinoatrial node. Ivabradine’s clinical potential has been investigated in the context of heart failure since it is associated with reduced myocardial oxygen demand, enhanced diastolic filling, stroke volume, and coronary perfusion time; however, it is yet to demonstrate definitive mortality benefit. Alternative effects of ivabradine include modulation of the renin-angiotensin-aldosterone system, sympathetic activation, and endothelial function. Here, we review key clinical trials informing the clinical use of ivabradine and explore opportunities for leveraging its potential pleiotropic effects in other diseases, including treatment of hyperadrenergic states and mitigating complications of COVID-19 infection.
... • In a murine model of acute viral myocarditis, ivabradine reduced HR, attenuated myocardial injury and fibrosis, decreased cardiac expression of proinflammatory cytokines (TNF-α and IL-6), reduced plasma norepinephrine level, improved left ventricular function and dimensions, thus preventing progression to dilated cardiomyopathy, and most importantly increased the survival rate [51,52]. In a murine model of chronic viral myocarditis, ivabradine mitigated cardiomyocyte apoptosis and improved left ventricular function and dimensions [53]. No clinical trial with ivabradine in myocarditis is currently available. ...
Besides acute respiratory distress syndrome, acute cardiac injury is a major complication in severe coronavirus disease 2019 (COVID-19) and associates with a poor clinical outcome. Acute cardiac injury with COVID-19 can be of various etiologies, including myocardial ischemia or infarction and myocarditis, and may compromise cardiac function, resulting in acute heart failure or cardiogenic shock. Systemic inflammatory response increases heart rate (HR), which disrupts the myocardial oxygen supply/demand balance and worsens cardiac energy efficiency, thus further deteriorating the cardiac performance of the injured myocardium. In fact, the combination of elevated resting HR and markers of inflammation synergistically predicts adverse cardiovascular prognosis. Thus, targeted HR reduction may potentially be of benefit in cardiovascular pathologies associated with COVID-19. Ivabradine is a drug that selectively reduces HR via If current inhibition in the sinoatrial node without a negative effect on inotropy. Besides selective HR reduction, ivabradine was found to exert various beneficial pleiotropic effects, either HR-dependent or HR-independent, including anti-inflammatory, anti-atherosclerotic, anti-oxidant and antiproliferative actions and the attenuation of endothelial dysfunction and neurohumoral activation. Cardioprotection by ivabradine has already been indicated in cardiovascular pathologies that are prevalent with COVID-19, including myocarditis, acute coronary syndrome, cardiogenic shock or cardiac dysautonomia. Here, we suggest that ivabradine may be beneficial in the management of COVID-19-related cardiovascular complications.
... Five fields of view (×400) were selected in a random fashion, and the positive apoptotic cells were counted. 22 ...
Objective
Emerging articles have profiled the relations between microRNAs and viral myocarditis. This research was unearthed to explore the capacity of miR‐425‐3p on cardiomyocyte apoptosis in mice with viral myocarditis and its mechanism.
Methods
A total of 120 mice were classified into 4 groups in a random fashion (n = 30). The mice were intraperitoneally injected with coxsackievirus type B3 (CVB3) to induce myocarditis. On the 7th day after CVB3 infection, 10 mice in each group were euthanized to assess the heart function indices of mice, observe the pathological conditions, detect myocardial tissue apoptosis, and measure the inflammatory factor levels in myocardial tissues. Expression of miR‐425‐3p, transforming growth factor (TGF‐β1), and apoptosis‐associated proteins in myocardial tissues was determined. The remaining 20 mice in each group were used for survival observation. The luciferase activity assay was implemented to validate the relationship between miR‐425‐3p and TGF‐β1. miR‐425‐3p mimic was transfected into mouse cardiomyocytes HL‐1 and then infected with CVB3 to further verify the regulatory effect of miR‐425‐3p on the cardiomyocyte apoptosis in viral myocarditis.
Results
miR‐425‐3p was lowly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p improved the cardiac function, alleviated pathological conditions, reduced cardiomyocyte apoptosis, decreased Bax and cleaved Caspase‐3 expression, elevated Bcl‐2 expression, decreased levels of inflammatory factors and improved survival rate of mice with viral myocarditis. Luciferase activity assay verified that miR‐425‐3p could bind to TGF‐β1, and overexpressed miR‐425‐3p suppressed TGF‐β1, p‐smad2/smad2 and p‐smad3/smad3 expression. In vitro experiments further verified that overexpression of miR‐425‐3p inhibited the apoptosis of CVB3‐HL‐1 cells, and the addition of TGF‐β1 would reverse this effect.
Conclusion
Our research indicates that miR‐425‐3p is poorly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p inhibits cardiomyocyte apoptosis and myocardial inflammation in mice with viral myocarditis as well as improves their survival rates through suppressing the TGF‐β1/smad axis.
... The benefit of this combined medication appeared to be related to improvement in rates of progressive pump failure or sudden cardiac death/apoptosis [41]. Another medication; ivabradine was demonstrated in several experimental studies to exhibit cardioprotective effect through anti-apoptotic mechanisms and erythropoietin was also reported to prevent the apoptosis of vascular endothelial cells, and cardiomyocytes [42][43][44]. Knowing the role that beta adrenergic receptor stimulation play in cardiac injury and apoptosis, some beta blockers were also shown to provide significant cardioprotective effect against cardiomyocyte injury mediated through multiple mechanisms, including the inhibition of cardiomyocyte apoptosis [45,46]. Calcium channel blockers may also have a value as cardiopreventive in HF knowing that in children treated with anythracyclines, reactive oxygen species (ROS) can induce autophagy (a process of intracellular components' degradation) in cardiac myocytes, which in turn facilitates development of pathological hypertrophy and participates in the pathogenesis of HF, and that calcium overload has important role in maintaining autophagy at a higher level [47]. ...
Resumen
Introducción y objetivos
La ivabradina reduce el ritmo cardiaco bloqueando la corriente I(f) y conserva la presión sanguínea y el volumen sistólico por mecanismos aún desconocidos. La caveolina-3 induce cardioprotección formando complejos con varias proteínas, como el inductor de metaloproteinasas EMMPRIN y HCN4, la diana de la ivabradina. Consideramos que la cardioprotección de la ivabradina se basa en la inhibición la degradación de la matriz extracelular.
Métodos
En un modelo porcino de shock cardiogénico, se estudió la integridad del corazón, las concentraciones de MMP-9 y EMMPRIN y la estabilidad de los complejos proteicos caveolina-3/HCN4 con EMMPRIN en respuesta a la ivabradina.
Resultados
La administración de ivabradina 0,3 mg/kg redujo significativamente la necrosis y la expresión de MMP-9 tras el shock cardiogénico, mientras que el ARNm de EMMPRIN, su proteína y la glucosilación (requerida para la activación de las MMP) no se vieron afectados. Sin embargo, los complejos caveolina-3/LG-EMMPRIN (EMMPRIN poco glucosilado) y caveolina-3/HCN4 aumentaron, mientras que la ivabradina inhibió también el nuevo complejo encontrado entre HCN4 y el EMMPRIN muy glucosilado. Para comprobar si la caveolina-3 puede ser puente entre HCN4 y EMMPRIN, el complejo HCN4/EMMPRIN se mantuvo incluso tras el silenciamiento génico de la caveolina-3, lo que indica una interacción directa de ambas proteínas. De manera similar, el silenciamiento de EMMPRIN redujo significativamente el complejo caveolina-3/HCN4, que regula la I(f).
Conclusiones
Además de la inhibición de la I(f), la ivabradina puede inducir cardioprotección al inhibir la degradación de la matriz extracelular por conservar el complejo caveolina-3/LG-EMMPRIN y controlar el ritmo cardiaco estabilizando el complejo caveolina-3/HCN4.
Introduction and objectives
Ivabradine reduces heart rate by blocking the I(f) current and preserves blood pressure and stroke volume through unknown mechanisms. Caveolin-3 protects the heart by forming protein complexes with several proteins, including extracellular matrix (ECM)-metalloproteinase-inducer (EMMPRIN) and hyperpolarization-activated cyclic nucleotide-gated channel 4 (HN4), a target of ivabradine. We hypothesized that ivabradine might also exert cardioprotective effects through inhibition of ECM degradation.
Methods
In a porcine model of cardiogenic shock, we studied the effects of ivabradine on heart integrity, the levels of MMP-9 and EMMPRIN, and the stability of caveolin-3/HCN4 protein complexes with EMMPRIN.
Results
Administration of 0.3 mg/kg ivabradine significantly reduced cardiogenic shock-induced ventricular necrosis and expression of MMP-9 without affecting EMMPRIN mRNA, protein, or protein glycosylation (required for MMP activation). However, ivabradine increased the levels of the caveolin-3/LG-EMMPRIN (low-glycosylated EMMPRIN) and caveolin-3/HCN4 protein complexes and decreased that of a new complex between HCN4 and high-glycosylated EMMPRIN formed in response to cardiogenic shock. We next tested whether caveolin-3 can bind to HCN4 and EMMPRIN and found that the HCN4/EMMPRIN complex was preserved when we silenced caveolin-3 expression, indicating a direct interaction between these 2 proteins. Similarly, EMMPRIN-silenced cells showed a significant reduction in the binding of caveolin-3/HCN4, which regulates the I(f) current, suggesting that, rather than a direct interaction, both proteins bind to EMMPRIN.
Conclusions
In addition to inhibition of the I(f) current, ivabradine may induce cardiac protection by inhibiting ECM degradation through preservation of the caveolin-3/LG-EMMPRIN complex and control heart rate by stabilizing the caveolin-3/HCN4 complex.
Ivabradine is a pure heart-rate lowering drug that is nowadays used, accordingly to the last ESC Guidelines, to reduce mortality and heart failure (HF) hospitalization in patients with HF with reduced ejection fraction and in symptomatic patiens with inappropriate sinus tachycardia. Moreover, interesting effect of ivabradine on endothelial and myocardial function and on oxidative stress and inflamation pathways are progressively emerging. The aim of this paper is to highlight newer evidences about ivabradine effect (and consequently possible future application of the drug) in pathological settings different from guidelines-based clinical practice.
Post-transcriptional gene silencing is an effective tool for viral replication control at the epigenetic level. In this study, we aimed to produce dsRNAs and siRNA pools targeting the genetic region for the viral protease 3C and the genetic region covering the sequences for VP1 and VP3 capsid proteins of the Coxsackievirus B3 cardiotropic Woodruff strain by the use of the polymerase complex of bacteriophage Phi6 in HEp-2 monolayer cells. The dsRNAs obtained in this study, specific for the 3C and VP1-VP3 genetic regions of the virus, were characterized by very low cytotoxicity (up to 200 nmol/L and 100 nmol/L, respectively) and high efficiency at silencing the target genes and blocking the enteroviral replication in vitro (93% and 60% reduction of the virus infected cells, respectively, at concentrations of 40 nmol/L). The generated pools of overlapping siRNAs targeting the 3C or VP1-VP3 genetic regions showed insignificant cytotoxicity at concentrations up to 200 nmol/L (< 3%) and higher efficacy than the corresponding dsRNAs. We managed to achieve 95% inhibition of the CVB3 Woodruff strain replication in vitro by using siRNAs specific for the 3C coding region of the virus at a concentration of 40 nmol/L, with no cytotoxicity.
Chronic heart failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased heart rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.
Coxsackievirus B3 (CVB3)-induced myocardial damage always leads to serious heart failure by inducing cardiac injury. NLRP3 inflammasome activation has been identified as a central player in the pathogenesis of CVB3-induced viral myocarditis. Therefore, restraining NLRP3 inflammasome activation has been supposed to significantly alleviate the severity of myocardial damage and improve cardiac function. Morroniside (MR), one of the main iridoid glycosides, has the ability to depress the production of reactive oxygen species (ROS) and restrain the expression of caspase-3 and -9. Of importance, ROS and caspase are essential for NLRP3 inflammasome activation in response to CVB3 infection. Therefore, in the present study, MR was selected as a model drug to alleviate CVB3-induced myocardial damage. The results of cardiac function index determination showed that abnormal indexes including mean arterial pressure, heart rate, and left ventricular systolic pressure of myocardial damage rats could be recovered by treating with MR. Such results can be further verified by histopathological evaluation, with the heart tissues of CVB3-infected rats displaying the most amount of H&E and TUNEL positive cells. The underlying mechanism by which MR improves the cardiac function was subsequently investigated. The detection of various gene levels indicated that NLRP3 inflammasome activation was inhibited by MR through down-regulating the expression of pro-inflammatory cytokines: interleukin (IL)-β and IL-18, the pivotal factors that lead to inflammatory responses. More importantly, the related genes, cardiac function indexes, and various myocardial damage markers of normal rats treated with MR did not exhibit any obvious changes compared with the control group, indicating a satisfactory biocompatibility of MR. In summary, MR holds a great potential in the alleviation of CVB3-induced myocardial damage with a negligible cytotoxicity to normal heart tissues.
