scholarly journals Baicalin Improves Cardiac Outcome and Survival by Suppressing Drp1-Mediated Mitochondrial Fission after Cardiac Arrest-Induced Myocardial Damage

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jun Wu ◽  
Hui Chen ◽  
Jiahong Qin ◽  
Nan Chen ◽  
Shiqi Lu ◽  
...  

Myocardial injury after cardiac arrest (CA) often results in severe myocardial dysfunction and death involving mitochondrial dysfunction. Here, we sought to investigate whether baicalin, a natural flavonoid compound, exerts cardioprotection against CA-induced injury via regulating mitochondrial dysfunction. We subjected the rats to asphyxia CA after a daily baicalin treatment for 4 weeks. After the return of spontaneous circulation, baicalin treatment significantly improved cardiac function performance, elevated survival rate from 35% to 75%, prevented necrosis and apoptosis in the myocardium, which was accompanied by reduced phosphorylation of Drp1 at serine 616, inhibited Drp1 translocation to the mitochondria and mitochondrial fission, and improved mitochondrial function. In H9c2 cells subjected to simulated ischemia/reperfusion, increased phosphorylation of Drp1 at serine 616 and subsequently enhanced mitochondrial Drp1 translocation as well as mitochondrial fission, augmented cardiomyocyte death, increased reactive oxygen species production, released cytochrome c from mitochondria and injured mitochondrial respiration were efficiently improved by baicalin and Drp1 specific inhibitor with Mdivi-1. Furthermore, overexpression of Drp1 augmented excessive mitochondrial fission and abolished baicalin-afforded cardioprotection, indicating that the protective impacts of baicalin are linked to the inhibition of Drp1. Altogether, our findings disclose for the first time that baicalin offers cardioprotection against ischemic myocardial injury after CA by inhibiting Drp1-mediated mitochondrial fission. Baicalin might be a prospective therapy for the treatment of post-CA myocardial injury.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Tao Jin ◽  
Cheng Cheng ◽  
Hui Li ◽  
Lian Liang ◽  
Guozhen Zhang ◽  
...  

Introduction: Previous studies have demonstrated that ferroptosis, a newly defined iron-dependent cell death, mediates ischemia/reperfusion induced cardiomyopathy. However, it is unclear whether ferroptosis plays a role in post-resuscitation myocardial dysfunction (PRMD). This study investigated the effects of UAMC-3203, a novel analog of ferroptosis specific inhibitors, on myocardial function after cardiopulmonary resuscitation (CPR). Hypothesis: Administration of UAMC-3203 during CPR alleviates PRMD in a rat model of cardiac arrest (CA) and CPR. Methods: 18 male Sprague-Dawley rats weighing between 450-550g were randomized into 3 groups: 1) Sham, 2) Control, and 3) UAMC-3203 (5mg/kg, IP at start of precordial compression). Ventricular fibrillation (VF) was induced and continued for 6min. CPR was then initiated for 8min, after which defibrillation was attempted. Ejection fraction (EF), cardiac output (CO) and myocardial performance index (MPI) were measured by echocardiography at baseline, 15min, 1h, 3h and 6h respectively after return of spontaneous circulation (ROSC). Results: A significant reduction in cardiac function was observed after resuscitation. At 15 minutes after ROSC, ultrasound showed no difference in cardiac function between UAMC and control. However, at 1, 3, and 6 h after ROSC, UAMC significantly improved myocardial function (p<0.05) (Fig. 1). Conclusion: A ferroptosis-specific inhibitor, UAMC-3203, alleviated PRMD significantly in a rat of model of CA and CPR. Further study is needed to determine the benefit of this agent in larger animals and potential safety in humans before it can be tested in clinical resuscitation.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Willard W Sharp ◽  
Lin Piao ◽  
Yong Fang ◽  
David G Beiser ◽  
James K Liao ◽  
...  

Rationale: Severe myocardial contractile dysfunction following resuscitation from cardiac arrest (CA) is a major contributor to CA mortality. The pathophysiology and etiology of this dysfunction is not known and there are no pharmacological therapies known to improve outcomes. Previously, we demonstrated that Dynamin related protein 1 (Drp1) is activated and recruited to the mitochondria during CA and that the Drp1 inhibitor Mdivi-1 improves post CA survival. Objective: To determine the effects of CA length on myocardial and mitochondrial function. We also sought to determine the effects of Mdivi-1 on post CA outcomes. Methods and Results: Asystolic cardiac arrest (CA) was induced in mice by IV injection of 0.08 mg/g KCL. CPR begun at 4, 8, 12, and 16 minutes post-cardiac arrest had rates of return of spontaneous circulation (ROSC) of 100%(12/12), 93%(14/15), 71%(10/14), and 44% (4/9) and 2-hour survival of 100%(12/12), 67%(10/15), 50%(7/14), and 11%(1/9). Transthoracic echocardiography 15 min post-resuscitation demonstrated percent fractional shortening of 36±4% (Sham,n=6), 30±4% (4 minCA,n=11), 24±5% (8minCA,n=10), 15±2% (12minCA,n=12). In surviving animals, myocardial dysfunction persisted for 2 hours post-resuscitation, but slowly recovered to baseline by 72 hours. No evidence of myocardial necrosis, inflammation, or apoptosis was noted following resuscitation. Progressive increases in mitochondrial derived reactive oxygen species (ROS) during CA was observed by MitoSOX red myocardial tissue staining. Mitochondria isolated from 12 min CA hearts demonstrated decreased substrate coupled and uncoupled respiration. Mdivi-1, a mitochondrial inhibitor of division (fission), improved survival and neurological scores in mice following an 8 min cardiac arrest compared to controls. Conclusions: Severe, time dependent myocardial stunning (contractile dysfunction in the absence of irreversible injury) was observed following asystolic cardiac arrest. This myocardial stunning was associated with mitochondrial injury and improved by an inhibitor of Drp1. Strategies targeting ischemia/reperfusion-induced changes in mitochondrial dynamics hold promise for improving myocardial function and survival following cardiac arrest.


2019 ◽  
Vol 20 (14) ◽  
pp. 3523 ◽  
Author(s):  
Andrew J. Lautz ◽  
Basilia Zingarelli

Myocardial dysfunction is common in septic shock and post-cardiac arrest but manifests differently in pediatric and adult patients. By conventional echocardiographic parameters, biventricular systolic dysfunction is more prevalent in children with septic shock, though strain imaging reveals that myocardial injury may be more common in adults than previously thought. In contrast, diastolic dysfunction in general and post-arrest myocardial systolic dysfunction appear to be more widespread in the adult population. A growing body of evidence suggests that mitochondrial dysfunction mediates myocardial depression in critical illness; alterations in mitochondrial electron transport system function, bioenergetic production, oxidative and nitrosative stress, uncoupling, mitochondrial permeability transition, fusion, fission, biogenesis, and autophagy all may play key pathophysiologic roles. In this review we summarize the epidemiologic and clinical phenotypes of myocardial dysfunction in septic shock and post-cardiac arrest and the multifaceted manifestations of mitochondrial injury in these disease processes. Since neonatal and pediatric-specific data for mitochondrial dysfunction remain sparse, conclusive age-dependent differences are not clear; instead, we highlight what evidence exists and identify gaps in knowledge to guide future research. Finally, since focal ischemic injury (with or without reperfusion) leading to myocardial infarction is predominantly an atherosclerotic disease of the elderly, this review focuses specifically on septic shock and global ischemia-reperfusion injury occurring after resuscitation from cardiac arrest.


Author(s):  
Yong He ◽  
Guoxing Wang ◽  
Chuang Li ◽  
Yuxing Wang ◽  
Qian Zhang

Abstract Background MiRNA-155 and miRNA-145 have been demonstrated to function as a key regulator in the development of the cardiovascular system. Recent experimental and clinical studies have indicated the cardioprotective role of sildenafil during ischemia/reperfusion (I/R) injury. This study was designed to investigate if administration of sildenafil will attenuate post-resuscitation myocardial dysfunction by regulating miRNA-155 and miR-145 expressions. Methods Thirty-two male pigs (weighing 30 ± 2 kg) were randomly divided into 4 groups, sildenafil group (n = 8), sildenafil +NG-nitro-l-arginine methyl ester (L-NAME) (20 mg/kg L) group (n = 8), saline (SA group, n = 8); and sham operation group (sham group, n = 8). Eight minutes of untreated VF was followed by defibrillation in anesthetized, closed-chest pigs. Hemodynamic status and blood samples were obtained at 0 min, 0.5, 1, 2, 4 and 6 h after return of spontaneous circulation (ROSC), and the hearts were removed and analyzed under electron microscopy, quantitative real-time polymerase chain reaction and ultra structural analysis were performed to evaluate myocardial injury. Results Compared with the sildenafil + L-NAME and saline groups, the sildenafil group had better outcomes in terms of hemodynamic and oxygen metabolism parameters as well as 24-h survival rate, and attenuated myocardial injury; In this study, CA pigs showed evidently increased levels of miR-155-5p and miR-145-5p, while the sildenafil treatment decreased the levels of miR-155-5p and miR-145-5p in CA pigs. In addition, the levels of eNOS was decreased in CA pigs, validating sildenafil attenuating post-resuscitation myocardial dysfunction by regulating miRNA-155 and miR-145 expressions. Conclusions Sildenafil group had better outcomes in terms of hemodynamic and oxygen metabolism parameters as well as 24-h survival rate, inhibited the increases in the miR-155-5p and miR-145-5p levels and attenuated myocardial injury in a porcine model of CA and resuscitation.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Fenglian He

N-acetylcysteine improves post reperfusion myocardial dysfunction in a Rat Model of Cardiac Arrest and return of spontaneous circulation Introduction: Studies have demonstrated that N-acetylcysteine (NAC) can attenuate regional myocardial ischemia/reperfusion injury and improved myocardial dysfunction. However, it is not clear whether NAC could protect post reperfusion myocardial dysfunction (PRMD) after cardiac arrest (CA) and return of spontaneous circulation (ROSC). In this study, we investigated the effect of NAC on post reperfusion myocardial dysfunction in a rat model of CA and ROSC. Hypothesis: NAC reduces the severity of PRMD in a rat model of CA and ROSC. Method: Ten healthy male Sprague-Dawley rats weighting 450g–550g were utilized, and randomly divided into two groups: 1) control group; 2) NAC group (150mg/kg). Ventricular fibrillation (VF) was induced. After 8 mins of VF, CPR was initiated for 8 mins, and defibrillation was then attempted. Myocardial function was measured by echocardiography at baseline, 2, 4 and 6 hours after successful resuscitation. Result: Except one in the control group, all animals were resuscitated. Myocardial function of post-resuscitation was significantly decreased in all animals. However, myocardial function gradually improved in animals treated with NAC when compared with those in control groups (Figure). Conclusion: In a rat model of cardiac arrest, NAC improves post-resuscitation myocardial dysfunction Figure The post-resuscitation myocardial dysfunction. BL, baseline; VF, ventricular fibrillation; CO, cardiac output; EF, ejection fraction; MPI, myocardial performance index; CPR, cardiopulmonary resuscitation; C group,control group; N group, NAC intervention group; * p < 0.05.vs. the C group.


2020 ◽  
Author(s):  
Yong He ◽  
Guoxing Wang ◽  
Chuang Li ◽  
YUXING WANG ◽  
QIAN ZHANG

Abstract Background: MiRNA-155 and miRNA-145 have been demonstrated to function as a key regulator in the development of the cardiovascular system. Recent experimental and clinical studies have indicated the cardioprotective role of sildenafil during ischemia/reperfusion (I/R) injury. This study was designed to investigate if administration of sildenafil will attenuate post-resuscitation myocardial dysfunction by regulating miRNA-155 and miR-145 expressions.Methods: Thirty-two male pigs (weighing 30 ± 2 kg) were randomly divided into 4 groups, sildenafil group (n= 8), sildenafil +NG-nitro-l-arginine methyl ester (L-NAME) (20mg/kg L) group (n=8), saline (SA group, n=8); and sham operation group (sham group, n=8). Eight minutes of untreated VF was followed by defibrillation in anesthetized, closed-chest pigs. Hemodynamic status and blood samples were obtained at 0 min, 0.5, 1, 2, 4 and 6h after return of spontaneous circulation (ROSC), and the hearts were removed and analyzed under electron microscopy, quantitative real-time polymerase chain reaction and ultra structural analysis were performed to evaluate myocardial injury.Results: Compared with the sildenafil + L-NAME and saline groups, the sildenafil group had better outcomes in terms of hemodynamic and oxygen metabolism parameters as well as 24-hour survival rate, and attenuated myocardial injury; In this study, CA pigs showed evidently increased levels of miR-155-5p and miR-145-5p, while the sildenafil treatment decreased the levels of miR-155-5p and miR-145-5p in CA pigs. In addition, the levels of eNOS was decreased in CA pigs, validating sildenafil attenuating post-resuscitation myocardial dysfunction by regulating miRNA-155 and miR-145 expressions.Conclusions: sildenafil group had better outcomes in terms of hemodynamic and oxygen metabolism parameters as well as 24-hour survival rate, inhibited the increases in the miR-155-5p and miR-145-5p levels and attenuated myocardial injury in a porcine model of CA and resuscitation.


Author(s):  
Kang Zhou ◽  
Yan Xu ◽  
Qiong Wang ◽  
Lini Dong

Abstract Myocardial injury is still a serious condition damaging the public health. Clinically, myocardial injury often leads to cardiac dysfunction and, in severe cases, death. Reperfusion of the ischemic myocardial tissues can minimize acute myocardial infarction (AMI)-induced damage. MicroRNAs are commonly recognized in diverse diseases and are often involved in the development of myocardial ischemia/reperfusion injury. However, the role of miR-431 remains unclear in myocardial injury. In this study, we investigated the underlying mechanisms of miR-431 in the cell apoptosis and autophagy of human cardiomyocytes in hypoxia/reoxygenation (H/R). H/R treatment reduced cell viability, promoted cell apoptotic rate, and down-regulated the expression of miR-431 in human cardiomyocytes. The down-regulation of miR-431 by its inhibitor reduced cell viability and induced cell apoptosis in the human cardiomyocytes. Moreover, miR-431 down-regulated the expression of autophagy-related 3 (ATG3) via targeting the 3ʹ-untranslated region of ATG3. Up-regulated expression of ATG3 by pcDNA3.1-ATG3 reversed the protective role of the overexpression of miR-431 on cell viability and cell apoptosis in H/R-treated human cardiomyocytes. More importantly, H/R treatments promoted autophagy in the human cardiomyocytes, and this effect was greatly alleviated via miR-431-mimic transfection. Our results suggested that miR-431 overexpression attenuated the H/R-induced myocardial damage at least partly through regulating the expression of ATG3.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Natalia A Riobo ◽  
Fei Han ◽  
Tong Da ◽  
Lance B Becker

Background: Reperfusion injury post-resuscitation is associated with metabolic dysfunction and free radicals production. It has been hypothesized that mitochondrial permeability changes induced by calcium overload underlies this uncoupling of respiration from ATP synthesis and initiates cytochrome c-dependent apoptotic cascades. Our goal is to evaluate the intrinsic status of the mitochondrial electron transfer chain, i.e. irreversible modifications, in resuscitated animals independently of transient changes in calcium and permeability. Methods: Female mice were subjected to 8 min cardiac arrest by KCl injection followed by mechanical ventilation and CPR until return of spontaneous circulation (resuscitation rate: 86%, 24 h survival: 40%) under continuous blood pressure and temperature monitoring. Animals were divided in 4 groups: SHAM (instrumented, no cardiac arrest), CA (8 min cardiac arrest), R30 (30 min post-resuscitation), and R60 (60 min post-resuscitation). Heart mitochondria were immediately isolated and physically disrupted to dissipate ionic gradients in the presence of a calcium chelator. Production of hydrogen peroxide (H 2 O 2 ) by Complex I and III was determined fluorometrically with the Amplex Red-HRP system and the activities of Complex I, II, and the Complex I-III and II-III segments by spectrophotometric techniques using appropriate substrates and inhibitors. Cytochrome c content and the COX IV subunit (as a loading control) were analyzed by western blot and densitometry. Results: A 40% increase in H 2 O 2 production by Complex I and III was evident after just 8 min of cardiac arrest (ECA group, p<0.05), which was followed by a progressive reduction in Complex I activity (ECA>R30>R60), resulting in a relative doubling of electron leak. In contrast, Complex II and II-III activities and cytochrome c content remained unaffected at all times evaluated. Conclusions: Using an animal model that closely mimics resuscitation in humans, we have found signs of early mitochondrial dysfunction independently of transient changes in permeability and calcium. These changes are consistent with increased ROS production at expense of impaired oxidative phosphorylation.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lorissa Lamoureux ◽  
Herbert K Whitehouse ◽  
Jeejabai Radhakrishnan ◽  
Raúl J Gazmuri

Background: We have reported in rat and swine models of cardiac arrest that sodium hydrogen exchanger isoform-1 (NHE-1) inhibition facilitates resuscitation, ameliorates myocardial dysfunction, and improves survival. Others have reported that α-methylnorepinephrine (α-MNE) - a selective α2-adrenoreceptor agonist - is superior to epinephrine given its lack of β-agonist effects. We examined in a rat model of VF and closed-chest resuscitation the effects of combining the NHE-1 inhibitor zoniporide (ZNP) with α-MNE. Methods: VF was electrically induced in 32 male retired breeder Sprague-Dawley rats and left untreated for 8 minutes after which resuscitation was attempted by an 8 minute interval of chest compression and delivery of electrical shocks. Rats were randomized 1:1:1:1 to receive a 3 mg/kg bolus of ZNP or 0.9% NaCl before starting chest compression and a 100 μg/kg bolus of α-MNE or its vehicle at minute 2 of chest-compressions establishing 4 groups of 8 rats each. Successfully resuscitated rats were monitored for 240 minutes. Results: The number of rats that had return of spontaneous circulation and then survived 240 min were: α-MNE(-)/ZNP(-) 4 and 2; α-MNE(-)/ZNP(+) 5 and 5; α-MNE(+)/ZNP(-) 2 and 1; and α-MNE(+)/ZNP(+) 7 and 7 yielding a statistically significant effect on overall survival times corresponding to 105 ± 114, 150 ± 124, 58 ± 108, and 210 ± 85 min, respectively (p < 0.045). Post-resuscitation lactate levels were attenuated in all treatment groups with the greatest effect by the α-MNE(+)/ZNP(+) combination without major differences in hemodynamic function (Table). Conclusion: We confirm a beneficial effect resulting from the combination of ZNP (given to attenuate myocardial reperfusion injury) and α-MNE (given to augment peripheral vascular resistance during chest compression without the detrimental actions of epinephrine). The proposed combination may prove to be a highly effective novel strategy for resuscitation from cardiac arrest.


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