scholarly journals Inhibiting miR-205 Alleviates Cardiac Ischemia/Reperfusion Injury by Regulating Oxidative Stress, Mitochondrial Function, and Apoptosis

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yuerong Xu ◽  
Wangang Guo ◽  
Di Zeng ◽  
Yexian Fang ◽  
Runze Wang ◽  
...  

Background. miR-205 is important for oxidative stress, mitochondrial dysfunction, and apoptosis. The roles of miR-205 in cardiac ischemia/reperfusion (I/R) injury remain unknown. The aim of this research is to reveal whether miR-205 could regulate cardiac I/R injury by focusing upon the oxidative stress, mitochondrial function, and apoptosis. Methods. Levels of miR-205 and Rnd3 were examined in the hearts with I/R injury. Myocardial infarct size, cardiac function, oxidative stress, mitochondria function, and cardiomyocyte apoptosis were detected in mice with myocardial ischemia/reperfusion (MI/R) injury. The primary neonatal cardiomyocytes underwent hypoxia/reoxygenation (H/R) to simulate MI/R injury. Results. miR-205 levels were significantly elevated in cardiac tissues from I/R in comparison with those from Sham. In comparison with controls, levels of Rnd3 were significantly decreased in the hearts from mice with MI/R injury. Furthermore, inhibiting miR-205 alleviated MI/R-induced apoptosis, reduced infarct size, prevented oxidative stress increase and mitochondrial fragmentation, and improved mitochondrial functional capacity and cardiac function. Consistently, overexpression of miR-205 increased infarct size and promoted apoptosis, oxidative stress, and mitochondrial dysfunction in mice with MI/R injury. In cultured mouse neonatal cardiomyocytes, downregulation of miR-205 reduced oxidative stress in H/R-treated cardiomyocytes. Finally, inhibiting Rnd3 ablated the cardioprotective effects of miR-205 inhibitor in MI/R injury. Conclusions. We conclude that inhibiting miR-205 reduces infarct size, improves cardiac function, and suppresses oxidative stress, mitochondrial dysfunction, and apoptosis by promoting Rnd3 in MI/R injury. miR-205 inhibitor-induced Rnd3 activation is a valid target to treat MI/R injury.

2019 ◽  
Vol 242 (2) ◽  
pp. 37-50 ◽  
Author(s):  
Sivaporn Sivasinprasasn ◽  
Siripong Palee ◽  
Kenneth Chattipakorn ◽  
Thidarat Jaiwongkum ◽  
Nattayaporn Apaijai ◽  
...  

Myocardial damage and mitochondrial dysfunction caused by cardiac ischemia-reperfusion (I/R) injury are intensified by endogenous estrogen deprivation. Although N-acetylcysteine (NAC) exerted cardioprotective effects, its benefits when used in combination with hormone therapy are unknown. We tested the hypothesis that a combination of NAC with low-dose estrogen improves cardiometabolic function and protects cardiac mitochondria against I/R injury, to a similar extent to regular-dose estrogen treatment, in estrogen-deprived rats. Female Wistar rats had a bilateral ovariectomy (OVX) or sham operation. Twelve weeks after the operation, OVX rats were treated with regular-dose estrogen (E; 50 µg/kg/day), low-dose estrogen (e; 25 µg/kg/day), NAC (N; 100 mg/kg/day) or combined low-dose estradiol with NAC (eN) for 4 weeks (n = 6/group). Metabolic parameters, echocardiography, heart rate variability and then cardiac I/R protocol involving 30-min coronary artery ligation, followed by 120-min reperfusion, were performed. OVX rats had increased body weight, visceral fat, fasting plasma glucose, HOMA-IR index, triglycerides, cholesterol and LDL levels (P < 0.05 vs sham). Only OVX-E and OVX-eN had a similarly improved HOMA-IR index. LVEF was increased in all treatment groups, but HRV was restored only by OVX-E and OVX-eN. After I/R, myocardial infarct size was decreased in both OVX-E and OVX-eN groups. OVX-E and OVX-eN rats similarly had a reduced mitochondrial ROS level and increased mitochondrial membrane potential in the ischemic myocardium. In conclusion, combined NAC with low-dose estrogen and regular-dose estrogen therapy similarly improve cardiometabolic function, prevent cardiac mitochondrial dysfunction and reduces the infarct size in estrogen-deprived rats with cardiac I/R injury.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Dong Wang ◽  
Xin Guo ◽  
Mingjie Zhou ◽  
Jichun Han ◽  
Bo Han ◽  
...  

This study was conducted to evaluate the cardioprotective property of the aqueous extract of lavender flower (LFAE). The myocardial ischemia/reperfusion (I/R) injury of rat was prepared by Langendorff retrograde perfusion technology. The heart was preperfused with K-H solution containing LFAE for 10 min before 20 minutes global ischemia, and then the reperfusion with K-H solution was conducted for 45 min. The left ventricular developed pressure (LVDP) and the maximum up/downrate of left ventricular pressure (±dp/dtmax) were recorded by physiological recorder as the myocardial function and the myocardial infarct size was detected by TTC staining. Lactate dehydrogenase (LDH) and creatine kinase (CK) activities in the effluent were measured to determine the myocardial injury degree. The superoxide anion dismutase (SOD) and malondialdehyde (MDA) in myocardial tissue were detected to determine the oxidative stress degree. The results showed that the pretreatment with LFAE significantly decreased the myocardial infarct size and also decreased the LDH, CK activities, and MDA level, while it increased the LVDP, ±dp/dtmax, SOD activities, and the coronary artery flow. Our findings indicated that LFAE could provide protection for heart against the I/R injury which may be related to the improvement of myocardial oxidative stress states.


2018 ◽  
Vol 49 (4) ◽  
pp. 1646-1658 ◽  
Author(s):  
Xiaoyan Huang ◽  
Yuguang Wang ◽  
Yi Wang ◽  
Liang Yang ◽  
Jia Wang ◽  
...  

Background/Aims: Epoxyeicosatrienoic acids (EETs) are cytochrome P450 epoxygenase (CYP) metabolites of arachidonic acid and have multiple cardiovascular effects. Ophiopogonin D (OP-D) is an important effective monomeric component in Shenmai injection (SM-I). Both have been reported to have a variety of biological functions, including anti-inflammatory, anti-oxidant, and anti-apoptotic effects. We previously demonstrated that OP-D–mediated cardioprotection involves activation of CYP2J2/3 and enhancement of circulating EETs levels in vitro and can be developed as a novel drug for the therapy of myocardial ischemia-reperfusion (MI/R) injury. We therefore hypothesized that the protective effects of OP-D and SM-I against MI/R injury are associated with increased expression of CYP2J3 and enhanced circulating 11,12-EET levels in vivo. Methods: A rat model of MI/R injury was generated by ligation of the left anterior descending coronary artery for 40 min, followed by reperfusion for 2 h to determine the protective effects and potential mechanisms of OP-D and SM-I. Electrocardiogram and ultrasonic cardiogram were used to evaluate cardiac function; 2,3,5-triphenyltetrazolium chloride was used to measure myocardial infarct size; hematoxylin and eosin staining and transmission electron microscopy were used to observe the morphology of myocardial tissue; and the expression of related proteins in the mechanistic study was observed by western blot analysis. Results: We found that OP-D and SM-I exert protective effects on MI/R injury, including regulation of cardiac function, reduction of lactate dehydrogenase and creatine kinase production, attenuation of myocardial infarct size, and improvement of the recovery of damaged myocardial structures. We found that OP-D and SM-I activate CYP2J3 expression and increase levels of circulating 11,12-EET in MI/R-injured rats. Conclusion: We tested the hypothesis that the cardioprotective effects of OP-D and SM-I on MI/R injury are associated with increased expression of CYP2J3 and enhanced circulating 11,12-EET levels in rats. Taken together, our results show that the effects of OP-D and SM-I were also mediated by the activation of the PI3K/Akt/eNOS signaling pathway, while inhibition of the NF-κB signaling pathway and antioxidant and anti-apoptotic effects were involved in the cardioprotective effects of OP-D and SM-I.


2020 ◽  
Author(s):  
Jing Yu ◽  
Jiandong He ◽  
Wenqu Yang ◽  
Xiang Wang ◽  
Gaoxiang Shi ◽  
...  

Abstract Background Sevoflurane postconditioning (SevP) is an effective way in relieving myocardial ischemia/reperfusion (IR) injury, which doesn’t work well in diabetic myocardium unfortunately. Prior studies have noted the importance of increasing oxidative stress in diabetic tissues. Noteworthily, mitochondrial fission mediated by dynamin-related protein 1 (Drp1) is an upstream pathway of reactive oxygen production. Whether Drp1 dependent mitochondrial fission is associated with the ineffectiveness of SevP in diabetic myocardium remains unknown. The aim of this study was to explore the important role of Drp1 in diabetic myocardium and investigate whether Drp1 inhibition could restore the cardioprotective effect of SevP. Methods In the first part, adult male Sprague-Dawley(SD) rats were divided into 6 groups. Rats in diabetic groups were fed with high-fat and high-sugar for 8 weeks, and then received a injection of streptozotocin (35 mg/kg) intraperitoneally. Myocardial IR was induced by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion༎SevP was applied by continuous inhalation of 2.5% sevoflurane 1 min before reperfusion, which lasted for 10 min. In the second part, mdivi-1 was used to investigate whether Drp1 inhibition could restore the cardioprotective effects of SevP in diabetic myocardium against I/R injury. The myocardial infarct size, pathology, mitochondrial ultrastructure, cardiomyocyte apoptosis, total SOD activity, MDA content, and Drp1 expression were detected. Results The diabetic myocardium displayed severer injury with greater infarct size and apoptosis. Up-regulated Drp1 expression concomitant with increased mitochondrial fission and oxidative stress were observed in diabetic myocardium subjected to I/R. The deteriorated changes were alleviated in normal but not in diabetic rats. Importantly, mdivi-1 administration significantly suppressed mitochondrial fission and oxidative stress, and the beneficial effects of SevP were restored by mdivi-1. Conclusions The present study indicates a crucial role of Drp1 dependent mitochondrial fission in diabetic myocardium subjected to IR. Drp1 inhibition may be effective in restoring the effect of SevP in reducing diabetic myocardial IR injury.


2018 ◽  
Vol 24 (4) ◽  
pp. 273-279
Author(s):  
Afshin Nazari ◽  
Khadige Zahabi ◽  
Yaser Azizi ◽  
Maryam Moghimian

ABSTRACT Exercise and apelin have been shown to increase cardiac function and elicit tolerance to ischemia/reperfusion (IR) injuries. This study aimed at determining whether the combination of exercise training and apelin pretreatment could integrate the protective effects of each of them in the heart against IR injury. Male rats were divided into four experimental groups: 1: Rats with ischemia/reperfusion (IR), 2: subjected to exercise training for 8 weeks (EX+IR), 3: apelin-13 (10 nmol/kg/day) for 7 days (Apel+IR) in the last week of training, and 4: exercise training plus apelin-13 (EX+Apel+IR). Isolated hearts were perfused using the Langendorff method and subjected to 30 min of regional ischemia followed by 60 min of reperfusion. Treadmill exercise training was conducted for 8 weeks. Hemodynamic parameters were recorded throughout the experiment. Ischemia-induced arrhythmias, myocardial infarct size (IS), creatine kinase-MB (CK-MB) isoenzyme and plasma lactate dehydrogenase (LDH) activity was measured in all animals. Administration of apelin-13 plus exercise increased left ventricular developed pressure (LVDP) at the end of ischemia and reperfusion compared with other groups. After 30 min of ischemia, dP/dtmax was higher in EX+Apel+IR than in Apel+IR and EX+IR groups. During 30 min ischemia, exercise training, apelin-13 and combined treatment produced a significant reduction in the numbers of premature ventricular complexes. A combination of exercise and apelin-13 also reduced infarct size, CK-MB, LDH and severity of arrhythmia. These results suggest that combined therapies with apelin-13 and exercise training may integrate the beneficial effects of each of them alone on cardiac contractility, arrhythmia and limiting of infarct size. Level of evidence I; Therapeutic Studies - Investigating the Results of Treatment.


2013 ◽  
Vol 305 (4) ◽  
pp. H477-H483 ◽  
Author(s):  
Jitka A. I. Virag ◽  
Ethan J. Anderson ◽  
Susan D. Kent ◽  
Harrison D. Blanton ◽  
Tracy L. Johnson ◽  
...  

We have previously shown that myocardial infarct size in nonreperfused hearts of mice with a functional deletion of the circadian rhythm gene mPer2 (mPer2-M) was reduced by 43%. We hypothesized that acute ischemia-reperfusion injury (I/R = 30 min I/2 h R) would also be reduced in these mice and that ischemic preconditioning (IPC) (3 × 5 min cycles) before I/R, which enhances protection in wild-type (WT) hearts, would provide further protection in mPer2-M hearts. We observed a 69 and 75% decrease in infarct size in mPer2-M mouse hearts compared with WT following I/R and IPC, respectively. This was coincident with 67% less neutrophil infiltration and 57% less apoptotic cardiomyocytes. IPC in mPer2-M mice before I/R had 48% less neutrophil density and 46% less apoptosis than their WT counterparts. Macrophage density was not different between WT and mPer2-M I/R, but it was 45% higher in mPer2-M IPC mouse hearts compared with WT IPC. There were no baseline differences in cardiac mitochondrial function between WT and mPer2-M mice, but, following I/R, WT exhibited a marked decrease in maximal O2 consumption supported by complex I-mediated substrates, whereas mPer2-M did not, despite no difference in complex I content. Moreover, cardiac mitochondria from WT mice exhibited a very robust increase in ADP-stimulated O2 consumption in response to exogenously added cytochrome c, along with a high rate of reactive oxygen species production, none of which was exhibited by cardiac mitochondria from mPer2-M following I/R. Taken together, these findings suggest that mPer2 deletion preserves mitochondrial membrane structure and functional integrity in heart following I/R injury, the consequence of which is preservation of myocardial viability. Understanding the mechanisms connecting cardiac events, mitochondrial function, and mPer2 could lead to preventative and therapeutic strategies for at risk populations.


2015 ◽  
Vol 35 (2) ◽  
pp. 676-688 ◽  
Author(s):  
Xiaoming Wang ◽  
Yanan Cao ◽  
Mingzhi Shen ◽  
Bo Wang ◽  
Weiwei Zhang ◽  
...  

Background/Aims: Anion channels such as chloride channel are known to participate in the regulation of a wide variety of cellular processes including development, differentiation, proliferation, apoptosis and regeneration. This study was designed to examine the effect of the non-selective anion channel blocker 4,4'-Diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS) on cardiac function and apoptosis using a rat model of ischemia/reperfusion (I/R). Methods: Fifty male SD rats were randomly divided into the following groups including sham, I/R and I/R+DIDS (7, 14 or 28 mg/kg). In DIDS group, rats received DIDS treatment (4 ml/kg/hr) at the beginning of reperfusion for 2 hrs using a programmed micro-pump. Cardiac function was evaluated including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) as well as positive and negative maximal derivatives of left ventricular pressure (± dP/dtmax). Myocardial infarct size was detected using the double staining with 2, 3, 5-triphenyl-2H-tetra-zolium chloride (TTC) and Evan's blue dye. DNA ladder, TUNEL assay, Bax and Bcl-2 protein levels were evaluated. Levels of ROS and Akt phosphorylation were detected. Results: I/R injury compromised cardiac function as manifested by reduced LVSP and ± dP/dtmax as well as pronounced apoptosis. I/R-induced cardiac anomalies were markedly ameliorated by DIDS. DIDS retarded I/R-induced myocardial infarct and apoptosis. In addition, DIDS ameliorated I/R-induced ROS production and Akt dephosphorylation in the heart. Conclusion: Taken together, our data revealed that DIDS may protect cardiomyocytes against I/R injury as evidenced by improved cardiac function, Bcl-2, Akt phosphorylation, and reduced myocardial apoptosis, Bax expression, ROS production and myocardial infarct size.


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