scholarly journals Cox-2 Negatively Affects the Protective Role of Propofol against Hypoxia/Reoxygenation Induced Cardiomyocytes Apoptosis through Suppressing Akt Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Kangmu Ma ◽  
Jiapei Qiu ◽  
Mi Zhou ◽  
Yang Yang ◽  
Xiaofeng Ye

Nowadays, the prevention of severe myocardium injury resulting from myocardial ischemia/reperfusion injury (I/R) has been recognized as an important subject in the field of ischemic heart disease. In this study, H9c2 cardiomyocytes were exposed to cycles of hypoxia/reoxygenation (H/R) to mimic myocardial I/R injury. Western blot analysis and qRT-PCR were performed to detect the expression of Cox-2, Akt and p-Akt. Cell viability, LDH release and activity of Caspase-3 were assessed to determine the protective effect of propofol. The results proved that the protective effect of propofol for H/R challenged cardiomyocytes was associated with Akt phosphorylation. We also revealed that treatment of propofol suppressed the expression of Cox-2 in cardiomyocytes which was up-regulated after H/R treatment. Conversely, the over-expression of Cox-2 inhibited Akt phosphorylation while enhancing cardiomyocytes apoptosis. Interestingly, Akt activator exhibited similar protective effect with propofol and could diminish the influences brought by over-expression of Cox-2. Thus, it could be concluded that Cox-2 negatively affects the protective effect of propofol against hypoxia/reoxygenation induced cardiomyocyte apoptosis by suppressing Akt phosphorylation.

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Heng Zhang ◽  
Xiao Wang ◽  
Yihua Ma ◽  
Yueping Shi

This study was aimed to investigate whether ginsenoside Rb1 (GS-Rb1) from the cardioprotective Chinese medicine ginseng can reduce hypoxia-reoxygenation (HR)-induced damage to cardiomyocytes by protecting the mitochondria. Mitochondria-mediated apoptosis plays a key role during myocardial ischemia-reperfusion injury (MIRI). When MIRI occurs, the continuous opening of the mitochondrial permeability transition pore (mPTP) causes mitochondrial damage and ultimately leads to apoptosis. We treated H9c2 cells, derived from rat embryonic cardiomyoblasts, with GS-Rb1, diazoxide, and 5-hydroxydecanoate (5-HD), using HR to simulate MIRI. We found that GS-Rb1 can reduce mPTP by stabilizing the mitochondrial membrane potential (MMP) and by reducing reactive oxygen species (ROS) during HR. This protects the mitochondria by reducing the release of cytochrome c and the expression of cleaved-caspase-3 in the cytoplasm, ultimately reducing apoptosis. During this process, GS-Rb1 and diazoxide showed similar effects. These findings provide some evidence for a protective effect of GS-Rb1 treatment on MIRI.


2015 ◽  
Vol 37 (6) ◽  
pp. 2444-2453 ◽  
Author(s):  
Jian Xiao ◽  
Xiaoyan Zhu ◽  
Bo Kang ◽  
Jibin Xu ◽  
Lihui Wu ◽  
...  

Background: Autophagy plays a significant role in myocardial ischemia reperfusion (IR) injury. Hydrogen sulfide (H2S) has been demonstrated to protect cardiomyocytes against IR injury, while whether it has anti-autophagy effect has not been known. The aim of this study was to investigate whether H2S regulates autophagy during IR injury and its possible mechanism. Methods and Results: The cardiomyocytes of neonatal rats were randomized into Con, hypoxia-reoxygenation (HR) and H2S protection groups. The severity of cell injury was evaluated by cell vitality (MTT) and lactate dehydrogenase (LDH) release assays, and autophagy level was evaluated by flow cytometry and the assessment of autophagy-related gene (Atg) expression, such as that of Beclin1 and LC3-II. In response to H2S, Beclin1 and LC3-II protein were found to be down-regulated and p-mTOR protein was found to be up-regulated, together with an increase in cell vitality and a decrease in LDH. Furthermore, to find out whether mTOR was involved in the protective effect of H2S, rapamycin, inhibiter of mTOR, was used with or without applying NaHS and HR. It was found that rapamycin attenuated the myocardiocyte protective effect of H2S. To demonstrate the effect of autophagy during HR injury, the cardiomyocytes were pre-treated with 3-MA, which is an autophagy inhibitor, cell injury was attenuated by 3-MA. Conclusions: H2S plays a myocardial protective role against IR injury by regulating autophagy via mTOR activation.


Author(s):  
Fengyun Zhou ◽  
Ting Feng ◽  
Xiangqi Lu ◽  
Huicheng Wang ◽  
Yangping Chen ◽  
...  

Abstract Mitochondrial reactive oxygen species (mtROS)-induced apoptosis has been suggested to contribute to myocardial ischemia/reperfusion injury. Interleukin 35 (IL-35), a novel anti-inflammatory cytokine, has been shown to protect the myocardium and inhibit mtROS production. However, its effect on cardiomyocytes upon exposure to hypoxia/reoxygenation (H/R) damage has not yet been elucidated. The present study aimed to investigate the potential protective role and underlying mechanisms of IL-35 in H/R-induced mouse neonatal cardiomyocyte injury. Mouse neonatal cardiomyocytes were challenged to H/R in the presence of IL-35, and we found that IL-35 dose dependently promotes cell viability, diminishes mtROS, maintains mitochondrial membrane potential, and decreases the number of apoptotic cardiomyocytes. Meanwhile, IL-35 remarkably activates mitochondrial STAT3 (mitoSTAT3) signaling, inhibits cytochrome c release, and reduces apoptosis signaling. Furthermore, co-treatment of the cardiomyocytes with the STAT3 inhibitor AG490 abrogates the IL-35-induced cardioprotective effects. Our study identified the protective role of IL-35 in cardiomyocytes following H/R damage and revealed that IL-35 protects cardiomyocytes against mtROS-induced apoptosis through the mitoSTAT3 signaling pathway during H/R.


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.


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